WorldWideScience

Sample records for afterloading

  1. Afterloading: The Technique That Rescued Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Aronowitz, Jesse N., E-mail: jesse.aronowitz@umassmemorial.org

    2015-07-01

    Although brachytherapy had been established as a highly effective modality for the treatment of cancer, its application was threatened by mid-20th century due to appreciation of the radiation hazard to health care workers. This review examines how the introduction of afterloading eliminated exposure and ushered in a brachytherapy renaissance.

  2. Experiences with alanine dosimetry in afterloading brachytherapy

    International Nuclear Information System (INIS)

    At the present, the most commonly used dosimetry for radiotherapy applications are ionisation chambers and thermoluminescent dosimeters (TLD). However, there are some undesirable characteristics of these dosimetry systems, such as large detection volume (ionisation chamber) as well as fading of the radiation induced signal with time and destructive readout (TLG). The present study is an investigation into the use of the alanine/ESR dosimetry in fractionated afterloading brachytherapy during the whole radiotherapy course. There are some qualities which make alanine dosimetry attractive. These are the linear energy response, low fading under standard conditions, and the nondestructive readout. Thus the alanine dosimetry makes possible cumulative dose measurements during the radiotherapy course and an archival storage. By ionizing radiation (gamma, e, n, p, charged particles) free radicals (unpaired electrons) are produced in the amino acid alanine. The continuous wave electron spin resonance (ESR) spectroscopy is used to determine the number of free radicals, which is proportional to the absorbed dose and the alanine content of the dosimeter. The ESR measurements were made at room temperature using a Bruker EPR analyzer EMS-104. The dosimeters used in the test are alanine pellets (23.72 mg weight, 4.9 mm diameter, 1 mm height) as well as flexible alanine film dosimeters (thickness about 500 μm). The dosimeters consist of a blend of L-alpha-alanine and a binder. The alanine content of the pellets and the film dosimeters is about 88 % and 50 % by weight, respectively. The dosimeters for the calculation of the dose-effect-relationship were irradiated at the Physical-Technical Bundesanstalt in Braunschweig by a standard 60Co source. The maximum deviation from the calculated linear function is about 0.12 Gy in the dose range up to 80 Gy. The goal of medical applications was the superficial dose measurement in afterloading brachytherapy during the radiotherapy course in

  3. Afterloading intracavitary irradiation and expanding stent for malignant biliary obstruction

    International Nuclear Information System (INIS)

    A double lumen catheter was developed as an apllicator for the remote afterloading (RALS) of 60Co source for the intracavitary irradiation of an obstructed common bile duct caused by carcinoma of the gallbladder. This was followed by the placement of nylon-covered expandable metallic stents to maintain patency. This combination effectively provided palliation. (author)

  4. Acceptance testing and commissioning of a new model HDR afterloader

    International Nuclear Information System (INIS)

    We have recently performed acceptance testing procedures and have commissioned a new model HDR afterloader, the Varian VariSource with ''Intelligent Drive.'' Our site was one of the first installations worldwide. It is our intent to describe our tests and the results of the tests particularly as they may differ from other afterloaders. The Ir-192 source is unique among afterloaders marketed in the US in that it is very slender (OD of source wire is 0.59 mm) and relatively long (two 0.5 cm sources for a total active length of 1.0 cm). A check of source homogeneity by autoradiograph as urged by the US Nuclear Regulatory Commission demonstrates no detectable source inhomogeneity. Reentrant well ionization chambers are calibrated in the US with a 3.5 mm long source at Accredited Dosimetry Calibration Laboratories. Therefore calibration needs to be considered with some care. Calibration of the first delivered source with a well ionization chamber indicated agreement with the manufacturer's stated activity to within 0.5%. Source positioning is checked with a device called a 'cam scale'. Tests have been carried out on this system and it has been found to accurately indicate source position to within ±0.5 mm. Timer accuracy has been found to be better than 0.1% for dwell times of several hundred seconds. The intelligent drive system and the small source diameter allow the source wire to negotiate paths with small radius of curvature. A series of tests have been made in which the source is forced to negotiate 'U' turns of decreasing radius of curvature. A 4.7 F, 100 cm long catheter was used for these tests and the 'U' turn was positioned at approximately 90 cm. Under these conditions, the VariSource was consistently able to traverse a 1.25 cm radius of curvature, which is better than the manufacturer's stated limit of 1.5 cm

  5. Physical characteristics of the Selectron high dose rate intracavitary afterloader

    Energy Technology Data Exchange (ETDEWEB)

    Chenery, S.G.A.; Pla, M.; Podgorsak, E.B. (Royal Victoria Hospital, Montreal, Quebec (Canada); McGill Univ., Montreal, Quebec (Canada))

    1985-08-01

    The physics measurements on a Selectron high dose-rate afterloading cobalt-60 unit are reported. The installation was found to be acceptable from the standpoint of radiation safety and cost effectiveness; hospital bed space was saved as treatment could be on an outpatient basis. A source calibration 4% higher than the value stated by the manufacturer was obtained. Measurement of the ratio of exposure rate in water to that in air confirmed the calibration and the applicability of correction factors for routine clinical dosimetry recommended in the literature.

  6. 10 CFR 35.647 - Additional technical requirements for mobile remote afterloader units.

    Science.gov (United States)

    2010-01-01

    ... on the remote afterloader unit, on the control console, and in the facility; (3) Viewing and intercom... 10 Energy 1 2010-01-01 2010-01-01 false Additional technical requirements for mobile remote... MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy Units, and Gamma Stereotactic...

  7. A new afterloading-applicator for primary brachytherapy of endometrial cancer. First clinical experiences. Neuentwicklung eines Afterloading-Applikators zur primaeren Behandlung des Endometriumkarzinoms. Erster klinischer Erfahrungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, M.; Schulz-Wendtland, R.; Richard, F. (Freiburg Univ. (Germany). Abt. Gynaekologische Radiologie); Hooft, E. van t' (Nucletron, Leersum (Netherlands))

    1991-09-01

    Presented is a new afterloading applicator used for primary brachytherapy of endometrial cancer. The advantages: The afterloading applicator holds six afterloading tubes which bundled together in a cover. After the cover is pulled back, the individual tubes expand as a result of the sleeve shape and of the inherent stress of the plastic material used and make direct contact with the endometrium and with the tumor. The applicator is 8 mm in diameter which means that the cervix has to be dilated to Hegar 8 or 9. Radiation planning is done on the basis of orthogonal localisation X-rays or MR. The newly designed applicator can be used for both HDR and LDR afterloading procedures. We have clinical experiences in 42 applications. (orig.).

  8. Remote afterloading interstitial radiotherapy of patients with vulva cancer

    International Nuclear Information System (INIS)

    Experience in application of interstitial gamma-therapy according remote afterloading technique for the period of 1991 - 1996 is described. Computer-aided programmed complex NPS (Nucletron) was used for dosimetric planning. Micro Selectron-LDR (Nucletron, Netherlands) with 137Cs source and Micro Selectron-HDR (Nucletron) with 192Ir sources were used for irradiation. Interstitial gamma-therapy was used as a component of associated radio- and combined therapy of 21 patients with primary vulva cancer and 10 patients with recurrent vulva cancer. It is shown that the complete tumor regression was attained in 48.4 %, partial regression in 35.5 %, stabilization of the process in 16.1 % of cases. Three-year survival of patients with primary vulva cancer was 33.7 %

  9. A new afterloading-applicator for primary brachytherapy of endometrial cancer

    International Nuclear Information System (INIS)

    Presented is a new afterloading applicator used for primary brachytherapy of endometrial cancer. The advantages: The afterloading applicator holds six afterloading tubes which bundled together in a cover. After the cover is pulled back, the individual tubes expand as a result of the sleeve shape and of the inherent stress of the plastic material used and make direct contact with the endometrium and with the tumor. The applicator is 8 mm in diameter which means that the cervix has to be dilated to Hegar 8 or 9. Radiation planning is done on the basis of orthogonal localisation X-rays or MR. The newly designed applicator can be used for both HDR and LDR afterloading procedures. We have clinical experiences in 42 applications. (orig.)

  10. 10 CFR 35.633 - Full calibration measurements on remote afterloader units.

    Science.gov (United States)

    2010-01-01

    ... Emitting Remote Afterloader Units, Teletherapy Units, and Gamma Stereotactic Radiosurgery Units § 35.633...) Length of the applicators; and (7) Function of the source transfer tubes, applicators, and transfer...

  11. Remote Afterloading High Dose Rate Brachytherapy AMC EXPERIANCES

    Energy Technology Data Exchange (ETDEWEB)

    Park, Su Gyong; Chang, Hye Sook; Choi, Eun Kyong; Yi, Byong Yong [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    1992-12-15

    Remote afterloading high dose rate brachytherapy(HDRB) is a new technology and needs new biological principle for time and dose schedule. Here, authors attempt to evaluate the technique and clinical outcome in 116 patients, 590 procedures performed at Asan Medical Center for 3 years. From Sep. 1985 to Aug 1992, 471 procedures of intracavitary radiation in 55 patients of cervical cancer and 26 of nasopharyngeal cancer, 79 intraluminal radiation in 12 of esophageal cancer, 11 of endobronchial cancer and 1 Klatskin tumor and 40 interstitial brachytherapy in 4 of breast cancer, 1 sarcoma and 1 urethral cancer were performed. Median follow-up was 7 months with range 1-31 months. All procedures except interstitial were performed under the local anesthesia and they were all well tolerated and completed the planned therapy except 6 patients. 53/58 patients with cervical cancer and 22/26 patients with nasopharynx cancer achieved CR. Among 15 patients with palliative therapy, 80% achieves palliation. We will describe the details of the technique and results in the text. To evaluate biologic effects of HDRB and optimal time/dose/fractionation schedule, we need longer follow-up. But authors feel that HDRB with proper fractionation schedule may yield superior results compared to the low dose rate brachytherapy considering the advantages of HDRB in safety factor for operator, better control of radiation dose and volume and patients comfort over the low dose brachytherapy.

  12. Control strategies for afterload reduction with an artificial vasculature device.

    Science.gov (United States)

    Giridharan, Guruprasad A; Cheng, Rolando Chip; Glower, Jacob S; Ewert, Daniel L; Sobieski, Michael A; Slaughter, Mark S; Koenig, Steven C

    2012-01-01

    Ventricular assist devices (VADs) have been used successfully as a bridge to transplant in heart failure patients by unloading ventricular volume and restoring the circulation. An artificial vasculature device (AVD) is being developed that may better facilitate myocardial recovery than VAD by controlling the afterload experienced by the native heart and controlling the pulsatile energy entering into the arterial system from the device, potentially reconditioning the arterial system properties. The AVD is a valveless, 80 ml blood chamber with a servo-controlled pusher plate connected to the ascending aorta by a vascular graft. Control algorithms for the AVD were developed to maintain any user-defined systemic input impedance (IM) including resistance, elastance, and inertial components. Computer simulation and mock circulation models of the cardiovascular system were used to test the efficacy of two control strategies for the AVD: 1) average impedance position control (AIPC)-to maintain an average value of resistance during left ventricular (LV) systole and 2) instantaneous impedance force feedback (IIFF) and position control (IIPC)-to maintain a desired value or profile of resistance and compliance. Computer simulations and mock loop tests were performed to predict resulting cardiovascular pressures, volumes, flows, and the resistance and compliance experienced by the native LV during ejection for simulated normal, failing, and recovering LV. These results indicate that the LV volume and pressure decreased, and the LV stroke volume increased with decreasing IM, resulting in an increased ejection fraction. Although the AIPC algorithm is more stable and can tolerate higher levels of sensor errors and noise, the IIFF and IIPC control algorithms are better suited to maintain any instantaneous IM or an IM profile. The developed AVD impedance control algorithms may be implemented with current VADs to promote myocardial recovery and facilitate weaning.

  13. Control strategies for afterload reduction with an artificial vasculature device.

    Science.gov (United States)

    Giridharan, Guruprasad A; Cheng, Rolando Chip; Glower, Jacob S; Ewert, Daniel L; Sobieski, Michael A; Slaughter, Mark S; Koenig, Steven C

    2012-01-01

    Ventricular assist devices (VADs) have been used successfully as a bridge to transplant in heart failure patients by unloading ventricular volume and restoring the circulation. An artificial vasculature device (AVD) is being developed that may better facilitate myocardial recovery than VAD by controlling the afterload experienced by the native heart and controlling the pulsatile energy entering into the arterial system from the device, potentially reconditioning the arterial system properties. The AVD is a valveless, 80 ml blood chamber with a servo-controlled pusher plate connected to the ascending aorta by a vascular graft. Control algorithms for the AVD were developed to maintain any user-defined systemic input impedance (IM) including resistance, elastance, and inertial components. Computer simulation and mock circulation models of the cardiovascular system were used to test the efficacy of two control strategies for the AVD: 1) average impedance position control (AIPC)-to maintain an average value of resistance during left ventricular (LV) systole and 2) instantaneous impedance force feedback (IIFF) and position control (IIPC)-to maintain a desired value or profile of resistance and compliance. Computer simulations and mock loop tests were performed to predict resulting cardiovascular pressures, volumes, flows, and the resistance and compliance experienced by the native LV during ejection for simulated normal, failing, and recovering LV. These results indicate that the LV volume and pressure decreased, and the LV stroke volume increased with decreasing IM, resulting in an increased ejection fraction. Although the AIPC algorithm is more stable and can tolerate higher levels of sensor errors and noise, the IIFF and IIPC control algorithms are better suited to maintain any instantaneous IM or an IM profile. The developed AVD impedance control algorithms may be implemented with current VADs to promote myocardial recovery and facilitate weaning. PMID:22635010

  14. Reduction in radiation exposure to nursing personnel with the use of remote afterloading brachytherapy devices

    Energy Technology Data Exchange (ETDEWEB)

    Grigsby, P.W.; Perez, C.A.; Eichling, J.; Purdy, J.; Slessinger, E. (Mallinckrodt Institute of Radiology, St. Louis, MO (USA))

    1991-03-01

    The radiation exposure to nursing personnel from patients with brachytherapy implants on a large brachytherapy service were reviewed. Exposure to nurses, as determined by TLD monitors, indicates a 7-fold reduction in exposure after the implementation of the use of remote afterloading devices. Quarterly TLD monitor data for six quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the nurses of 152 and 154 mrem (1.5 mSv). After the implementation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per nurse of 23 and 19 mrem (0.2 mSv). This is an 87% reduction in exposure to nurses with the use of these devices (p less than 0.01).

  15. Reduction in radiation exposure to nursing personnel with the use of remote afterloading brachytherapy devices

    International Nuclear Information System (INIS)

    The radiation exposure to nursing personnel from patients with brachytherapy implants on a large brachytherapy service were reviewed. Exposure to nurses, as determined by TLD monitors, indicates a 7-fold reduction in exposure after the implementation of the use of remote afterloading devices. Quarterly TLD monitor data for six quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the nurses of 152 and 154 mrem (1.5 mSv). After the implementation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per nurse of 23 and 19 mrem (0.2 mSv). This is an 87% reduction in exposure to nurses with the use of these devices (p less than 0.01)

  16. Fractionated afterloading irradiation as a new therapy method for inoperable cerebral tumors

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, H.; Scheffler, A.; Oppel, F.; Brock, M.; Brust, V.; Bauer, R.; Pannek, H.W.

    1986-07-01

    A method is shown for fractionated afterloading therapy of inoperable cerebral tumors. A 3 mm thick, tube-form applicator of noble metal which is closed at the front side is implanted into the tumor by a stereotaxic technique and firmly screwed together with the osseous calotte. It remains there up to two weeks, giving full mobility to the patient. The afterloading therapy with a moving iridium source is performed one or two times per day with individual doses of 2 Gray. Thus, the chronological and - to a certain extent - also the spatial dose distribution is variable when applying this method.

  17. A compilation of current regulations, standards and guidelines in remote afterloading brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, J.P.; Simion, G.P.; Kozlowski, S.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-10-01

    Over a dozen government and professional organizations in the United States and Europe have issued regulations and guidance concerning quality management in the practice of remote afterloading brachytherapy. Information from the publications of these organizations was collected and collated for this report. This report provides the brachytherapy licensee access to a broad field of quality management information in a single, topically organized document.

  18. Studies on 192Ir afterloading irradiation of the canine prostate with special consideration of thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    A method for high dose rate afterloading irradiation of the prostate with iridium 192 was developed. The isodoses of the urethra and rectum, which were measured by means of thermoluminescent dosimetry, showed deviations from the doses pre-calculated by computer (BRACHY), because this calculation is based on an anatomically ideal condition. (MBC)

  19. Real-time in vivo dosimetry and error detection during afterloading brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir

    Image guided afterloaded brachytherapy (BT) allows for conformal and patient specific radiotherapy (RT) treatments against cancer, where high dose concentrations are administered to the tumor volume and small doses to organs at risk (OARs). In afterloaded BT, ionizing radiation is delivered...... by means of a radionuclide attached to a source chain that is placed inside source catheters implanted in the target region. As for any RT treatment modality, BT treatments are subject to discrepancies between the delivered and planned treatments. Given the localized and high dose concentration near BT...... cervical cancer at the Aarhus University Hospital. The tools and methods developed for the implementation targeted requirements for accurate IVD and the demands for a time-efficient and straightforward clinical approach. The performance of all developments was explored based on IVD results for 20 PDR BT...

  20. Clinical results in carcinoma of the cervix: radium compared to caesium using remote afterloading.

    Science.gov (United States)

    Jackson, S M; Fairey, R N; Kornelsen, R O; Young, M E; Wong, F L

    1989-05-01

    In 1979 the Cancer Control Agency of British Columbia changed from radium to remote controlled afterloaded caesium in the treatment of carcinoma of the cervix. In the 3 years prior to the change, 139 patients received radium as part of their treatment and in the 3 years after the change, 158 patients received caesium. Overall referral patterns, patient and cancer demographics, and treatment policies were stable throughout the 6-year period. Radiotherapy technique, dose, dose distribution and dose rate were comparable for both radium and caesium treated patients. The results of treatment in the two time periods showed no difference in survival, local tumour control or complications. The use of afterloading has not compromised treatment results and has allowed better nursing care for patients and protection from radiation for all staff. PMID:2752690

  1. [Improvement of gynecologic radium therapy through the afterloading method using cesium 137].

    Science.gov (United States)

    Fournier, D V; Senf, W; Kuttig, H; Kubli, F

    1976-03-01

    For all centers performing gynecological contact irradiation the use of afterloading techniques is urgently required, since they eliminate any radiation exposure to the personnel. The radio-therapist may position and control the empty applicators still free from radiation withoug haste. This procedure diminishes the occurrence of overdosages and underdosages. The care for the patients is possible without radiation exposure, and the morbidity of contact therapy can be reduced by occasional mobilization of the patient, the applicator without sources remaining at its place. The fully automatic apparatus "Curietron" using cesium-137 sources (0.662 MeV gamma emission, half-life period 26.6 years) with an equivalent source activity (factor 2.6) yields the dose distribution demanded in the gynecologic field which in practice is identical to that of Ra-226 (medium gamma emission 1 MeV, half-life period 1620 years). With similar dose distribution, a biological and therapeutical effect alike to Ra-226 may be expected from Cs-137. In comparison with Ra-226, the following advantages of Cs-137 may be mentioned: Lower half-value thickness of 5.5 mm lead (low expenses for radioprotection), less danger with handling (no emanation of radioactive gases), and lower contamination risks in case of breaking. The measured dose distributions at equivalent source activity and similar geometry of the applicators revealed the possibility with regard of all techniques of gynecologic irradiation utilized in our field of arriving at similar relative and absolute dose distributions by means of the Cs-137 afterloading technique. Whilst short-term afterloading irradiation with highly active sources, their radiobiological effectiveness being not yet ascertained, has to be tested at appropriate scientific centers, it is necessary to demand afterloading techniques with dosages and duration of irradiations approved over decades for all centers of gynecological contact therapy because of radiation

  2. Pulmonary vascular wall stiffness: An important contributor to the increased right ventricular afterload with pulmonary hypertension

    OpenAIRE

    Wang, Zhijie; Chesler, Naomi C

    2011-01-01

    Pulmonary hypertension (PH) is associated with structural and mechanical changes in the pulmonary vascular bed that increase right ventricular (RV) afterload. These changes, characterized by narrowing and stiffening, occur in both proximal and distal pulmonary arteries (PAs). An important consequence of arterial narrowing is increased pulmonary vascular resistance (PVR). Arterial stiffening, which can occur in both the proximal and distal pulmonary arteries, is an important index of disease p...

  3. Frequency of afterload homocysteinemia in normal population of Southern Iran: a pilot study.

    Science.gov (United States)

    Akbari, A; Dehbozorgian, J; Afrasibi, A R; Gafari, H; Gerdabi, J; Karimi, M

    2010-04-01

    The objectives of the present pilot study were to investigate the effect of an oral methionine load on plasma homocysteine in healthy subjects southern Iran. We studied 50 peoples (10 men, 40 women, median age 27.5, range 20-37) referred to screening center for marriage since different part of southern Iran. Methionine (0.1 g kg(-1) b.wt.) was immediately administrated orally in 200 mL of orange juice and a second blood was obtained 4 h later. Plasma level of homocysteine was carried out by high performance liquid chromatography and flumetric detection. A homocysteine level above 15 mmol L(-1) was considered high. The mean fasting and afterload homocysteine were 15.28 and 31.29 micromol L(-1), respectively. Fasting hyperhomocysteinemia (>15 micromol L(-1)) was detected in 12% of male and 8% in female which significantly higher in men than women (p homocysteine levels (> 31 micromol L(-1)) was detected in 16% of male and 14%in female which higher in men than women. Notably 80% of participants had normal total homocystein concentration (homocystein levels (p = 0.000), in 8% of those normal homocystein level, methionine afterload homocystein levels became abnormal. In conclusion, based on results, we recommend the methionine afterload homocystein levels in high risk cases with normal fasting level in order to unmissed some cases with normal basal homocystein level. PMID:20836293

  4. Afterload reduction: a comparison of captopril and nifedipine in dilated cardiomyopathy.

    Science.gov (United States)

    Agostoni, P G; De Cesare, N; Doria, E; Polese, A; Tamborini, G; Guazzi, M D

    1986-01-01

    Nifedipine and captopril are potent vasodilators and may be expected to help left ventricular failure by reducing afterload. Nifedipine (20 mg three times a day) and captopril (50 mg three times a day) were added to an optimal regimen of digitalis and diuretics in a double blind crossover trial in 18 cases of dilated cardiomyopathy. New York Heart Association functional class rating symptoms and exercise tolerance times improved on captopril but not on nifedipine. The reduction in pulmonary capillary wedge pressure and the increase of cardiac output on captopril indicated that the augmented functional capacity may have resulted in part from an improved performance of the left ventricle. Although there were comparable decreases in systemic vascular resistance and presumably in impedence to ejection by the left ventricle on both drugs, the dimensions of the ventricular cavity were found to be reduced by captopril and augmented by nifedipine, and only captopril reduced the afterload (wall stress). In addition, the force-length relation (between left ventricular end systolic stress and end systolic diameter) was shifted to the left of baseline by captopril and to the right by nifedipine, suggesting that muscle contractility was reduced by nifedipine and not by captopril. These results suggest that nifedipine and captopril have different effects on afterload and contractility and these may account for the different effects of these drugs on the performance of the heart and clinical responses. PMID:3516187

  5. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L. [Pacific Science and Engineering Group, San Diego, CA (United States)] [and others

    1995-05-01

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error.

  6. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    International Nuclear Information System (INIS)

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error

  7. Human factors evaluation of remote afterloading brachytherapy. Volume 2, Function and task analysis

    International Nuclear Information System (INIS)

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the first phase of the project, which involved an extensive function and task analysis of RAB. This analysis identified the functions and tasks in RAB, made preliminary estimates of the likelihood of human error in each task, and determined the skills needed to perform each RAB task. The findings of the function and task analysis served as the foundation for the remainder of the project, which evaluated four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training and qualifications of RAB staff; and organizational practices and policies. At its completion, the project identified and prioritized areas for recommended NRC and industry attention based on all of the evaluations and analyses

  8. Human factors evaluation of remote afterloading brachytherapy. Volume 2, Function and task analysis

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Gwynne, J.W. III; Kelly, T.T.; Muckler, F.A. [Pacific Science and Engineering Group, San Diego, CA (United States); Saunders, W.M.; Lepage, R.P.; Chin, E. [University of California San Diego Medical Center, CA (United States). Div. of Radiation Oncology; Schoenfeld, I.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1995-05-01

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the first phase of the project, which involved an extensive function and task analysis of RAB. This analysis identified the functions and tasks in RAB, made preliminary estimates of the likelihood of human error in each task, and determined the skills needed to perform each RAB task. The findings of the function and task analysis served as the foundation for the remainder of the project, which evaluated four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training and qualifications of RAB staff; and organizational practices and policies. At its completion, the project identified and prioritized areas for recommended NRC and industry attention based on all of the evaluations and analyses.

  9. THYROID HORMONE REVERSES AGING-INDUCED MYOCARDIAL FATTY ACID OXIDATION DEFECTS AND IMPROVES THE RESPONSE TO ACUTELY INCREASED AFTERLOAD

    Energy Technology Data Exchange (ETDEWEB)

    Ledee, Dolena; Portman, Michael A.; Kajimoto, Masaki; Isern, Nancy G.; Olson, Aaron

    2013-06-07

    Background: Subclinical hypothyroidism occurs during aging in humans and mice and may contribute to development of heart failure. Aging also impairs myocardial fatty acid oxidation, causing increased reliance on flux through pyruvate dehydrogenase (PDH) to maintain function. We hypothesize that the metabolic changes in aged hearts make them less tolerant to acutely increased work and that thyroid hormone reverses these defects. Methods: Studies were performed on young (Young, 4-6 months) and aged (Old, 22-24 months) C57/BL6 mice at standard (50 mmHg) and high afterload (80 mmHg). Another aged group received thyroid hormone for 3 weeks (Old-TH, high afterload only). Function was measured in isolated working hearts along with substrate fractional contributions (Fc) to the citric acid cycle (CAC) using perfusate with 13C labeled lactate, pyruvate, glucose and unlabeled palmitate and insulin. Results: Cardiac function was similar between Young and Old mice at standard afterload. Palmitate Fc was reduced but no individual carbohydrate contributions differed. CAC and individual substrate fluxes decreased in aged. At high afterload, -dP/dT was decreased in Old versus Young. Similar to low afterload, palmitate Fc was decreased in Old. Thyroid hormone reversed aging-induced changes in palmitate Fc and flux while significantly improving cardiac function. Conclusion: The aged heart shows diminished ability to increase cardiac work due to substrate limitations, primarily impaired fatty acid oxidation. The heart accommodates slightly by increasing efficiency through oxidation of carbohydrate substrates. Thyroid hormone supplementation in aged mice significantly improves cardiac function potentially through restoration of fatty acid oxidation.

  10. High-dose-rate afterloading intracavitary irradiation and expandable metallic biliary endoprosthesis for malignant biliary obstruction

    International Nuclear Information System (INIS)

    A double lumen catheter was developed as an applicator for the remote afterloading system (RALS) of 60Co for the intracavitary irradiation of an obstructed common bile duct due to gallbladder cancer in 1 case and by cholangiocarcinoma in 7 cases. This was followed by the biliary endoprosthesis with expandable metallic stents to maintain patency. The mean survival period after treatment was not long (14 weeks). However, removal of the external drainage tube was possible in 7 of the 8 cases, and none of the 8 cases showed dislodgement or deformity of the stent, or obstruction of the bile duct in the stent-inserted area. This combination effectively provided palliation, and has considerable potential for malignant biliary obstruction. (author)

  11. Five years hospital experience with the Amersham caesium 137 manual afterloading system

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, T.J.; Davy, T.J.; Skeggs, D.B.L. (Royal Free Hospital, London (UK))

    1983-06-01

    The Amersham caesium 137 manual afterloading system for treatment of cancer of the uterine cervix and endometrium has been in use at the Royal Free Hospital for more than five years. The system uses permanently loaded flexible source pencils in combination with standard packs of disposable plastic applicators. Both sources and applicators have proved trouble-free in use. The sources are transported in special containers designed and built at the Royal Free Hospital and are inserted and removed on the ward by nursing staff. A set of sources is used in theatre for rectal and bladder dose measurements when the applicators are inserted. Staff radiation doses are low. The system is mainly used to produce pear-shaped dose distributions similar to those of the Manchester system, but simple cylindrical distributions are possible using symmetrically loaded source pencils.

  12. Radiological safety problems in intracavitary brachytherapy using the manual afterloading in Venezuela

    International Nuclear Information System (INIS)

    In three venezuelan public hospitals it was detected radioactive contamination for Cs-137 during inspection with the wipe test technique in areas where is applied intracavitary brachytherapy using manual afterloading. This caused a condition of great stress in the personal engaged the treatments. In each Cs-137 source in these hospitals was tested leakage. The source plastic holder was analysed. The authors were able to demonstrate: a) The radioactive contamination found in the treatment area had its origin in the Cs-137 capsule corrosion and b) The corrosion in the source capsule was produced by the radiolytic degradation of the PVC tube used as source-holder in the intracavitary treatments. (authors). 3 refs., 1 tab

  13. Implication of uterine configuration on dosimetry to point A using the Amersham afterloading system.

    Science.gov (United States)

    Vedula, R

    1993-03-15

    Ninety-four biopsy-proven cases of cervix carcinoma who underwent brachytherapy with the flexible Amersham afterloading system are examined in this study. The uterine configuration showed a wide range with respect to the length, angle of version (indicated by angle alpha) and the degree of right or left shift of the midline at the internal os (indicated by angle beta). The manufacturers of the afterloading system have given certain precalculated dose rates to A which they derived from computer calculations for the various configurations of the system, for a particular loading strength of the Caesium 137 source trains, and for a particular range of angle alpha and beta. The study involves mathematical calculations of point A dose rates using post application radiographs, and a mean value of point A dose rate is derived to compare with other variables. A distortion of the uterus in the form of flexion (as opposed to version), resulting in bending of the uterine tandem is noted in 3 cases. There are 22% of cases with gross degree of retroversion (angle alpha more than 180 degrees) for which the precalculated tables are lacking. The angle beta, however, is in the normal range for all the cases but one. Nineteen cases (20.2%) showed point A dose rates which are beyond the specified dose rates of the manufacturers. Analysis of these 19 cases showed 6 cases with angle alpha more than 180 degrees, eight cases with more than a 10 degrees shift of the uterus to right or left of midline (angle beta) and the rest five cases have fairly normal values of these angles. Analysis of these five cases showed that three of them showed more than 8 CGy/hr difference in dose rates to individual points A right and left. An undue curvature of the uterine tandem to one side in the distal half, with a straight proximal half (near the anterior flange) is noted in these three cases. The angle alpha and beta are normal here since the nearest 2 cm of uterine tandem to the anterior flange is

  14. Development of computerized dose planning system and applicator for high dose rate remote afterloading irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, T. J. [Keimyung Univ., Taegu (Korea); Kim, S. W. [Fatima Hospital, Taegu (Korea); Kim, O. B.; Lee, H. J.; Won, C. H. [Keimyung Univ., Taegu (Korea); Yoon, S. M. [Dong-a Univ., Pusan (Korea)

    2000-04-01

    To design and fabricate of the high dose rate source and applicators which are tandem, ovoids and colpostat for OB/Gyn brachytherapy includes the computerized dose planning system. Designed the high dose rate Ir-192 source with nuclide atomic power irradiation and investigated the dose characteristics of fabricated brachysource. We performed the effect of self-absorption and determining the gamma constant and output factor and determined the apparent activity of designed source. he automated computer planning system provided the 2D distribution and 3D includes analysis programs. Created the high dose rate source Ir-192, 10 Ci(370GBq). The effective attenuation factor from the self-absorption and source wall was examined to 0.55 of the activity of bare source and this factor is useful for determination of the apparent activity and gamma constant 4.69 Rcm{sup 2}/mCi-hr. Fabricated the colpostat was investigated the dose distributions of frontal, axial and sagittal plane in intra-cavitary radiation therapy for cervical cancer. The reduce dose at bladder and rectum area was found about 20 % of original dose. The computerized brachytherapy planning system provides the 2-dimensional isodose and 3-D include the dose-volume histogram(DVH) with graphic-user-interface mode. emoted afterloading device was built for experiment of created Ir-192 source with film dosimetry within {+-}1 mm discrepancy. 34 refs., 25 figs., 11 tabs. (Author)

  15. [Mathematical Modelling of the Dependence of the Performance of the Left Ventricle of the Heart on Preload and Afterload].

    Science.gov (United States)

    Syomin, F A; Zberia, M V; Koubassova, N A; Tsaturyan, A K

    2015-01-01

    The results of the numerical simulation of the end-diastolic, end-systolic and stroke volumes of the left ventricle of the heart are presented. The simulation was based on a published simple kinetic model of cardiac muscle and approximation of the ventricle geometry with thick-wall cylinder where the fibre orientation varied linearly from sub-epicardium towards sub-endocardium. Blood flow was modelled with a liner compartment model. This simplified approach provides correct dependencies of the stroke volume on the pre- and afterload, namely end-diastolic pressure and peripheral resistance. The calculations show that the stroke volume is independent of arterial compliance and blood inertia. PMID:26841514

  16. Two years experience with a computer-assisted monitoring and recording system used in gynecological afterloading therapy

    International Nuclear Information System (INIS)

    A computer program running on a simple desk-calculator has been developed for monitoring and recording gynecological high-dose afterloading therapy. For treatment monitoring the multiple-probe AM6-system (PTW-Freiburg) is used which allows for dose measurements in the urinary bladder and the rectum. The probe signals are processed on line in order to indicate the actual dose at the measuring points. After completing the irradiation the treatment is documented. Performing fractionated treatment the measuring data are stored in the computer memory for calculating total accumulated dose. The above-described monitoring- and protocolling system has proven its usefulness during two years of clinical work. (orig.)

  17. Poster — Thur Eve — 40: Automated Quality Assurance for Remote-Afterloading High Dose Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Anthony; Ravi, Ananth [Sunnybrook Health Sciences Centre/Odette Cancer Centre (Canada)

    2014-08-15

    High dose rate (HDR) remote afterloading brachytherapy involves sending a small, high-activity radioactive source attached to a cable to different positions within a hollow applicator implanted in the patient. It is critical that the source position within the applicator and the dwell time of the source are accurate. Daily quality assurance (QA) tests of the positional and dwell time accuracy are essential to ensure that the accuracy of the remote afterloader is not compromised prior to patient treatment. Our centre has developed an automated, video-based QA system for HDR brachytherapy that is dramatically superior to existing diode or film QA solutions in terms of cost, objectivity, positional accuracy, with additional functionalities such as being able to determine source dwell time and transit time of the source. In our system, a video is taken of the brachytherapy source as it is sent out through a position check ruler, with the source visible through a clear window. Using a proprietary image analysis algorithm, the source position is determined with respect to time as it moves to different positions along the check ruler. The total material cost of the video-based system was under $20, consisting of a commercial webcam and adjustable stand. The accuracy of the position measurement is ±0.2 mm, and the time resolution is 30 msec. Additionally, our system is capable of robustly verifying the source transit time and velocity (a test required by the AAPM and CPQR recommendations), which is currently difficult to perform accurately.

  18. Poster — Thur Eve — 40: Automated Quality Assurance for Remote-Afterloading High Dose Rate Brachytherapy

    International Nuclear Information System (INIS)

    High dose rate (HDR) remote afterloading brachytherapy involves sending a small, high-activity radioactive source attached to a cable to different positions within a hollow applicator implanted in the patient. It is critical that the source position within the applicator and the dwell time of the source are accurate. Daily quality assurance (QA) tests of the positional and dwell time accuracy are essential to ensure that the accuracy of the remote afterloader is not compromised prior to patient treatment. Our centre has developed an automated, video-based QA system for HDR brachytherapy that is dramatically superior to existing diode or film QA solutions in terms of cost, objectivity, positional accuracy, with additional functionalities such as being able to determine source dwell time and transit time of the source. In our system, a video is taken of the brachytherapy source as it is sent out through a position check ruler, with the source visible through a clear window. Using a proprietary image analysis algorithm, the source position is determined with respect to time as it moves to different positions along the check ruler. The total material cost of the video-based system was under $20, consisting of a commercial webcam and adjustable stand. The accuracy of the position measurement is ±0.2 mm, and the time resolution is 30 msec. Additionally, our system is capable of robustly verifying the source transit time and velocity (a test required by the AAPM and CPQR recommendations), which is currently difficult to perform accurately

  19. Thyroid hormone reverses aging-induced myocardial fatty acid oxidation defects and improves the response to acutely increased afterload.

    Directory of Open Access Journals (Sweden)

    Dolena Ledee

    Full Text Available BACKGROUND: Subclinical hypothyroidism occurs during aging in humans and mice and may contribute to the development of heart failure. Aging also impairs myocardial fatty acid oxidation, causing increased reliance on flux through pyruvate dehydrogenase (PDH to maintain function. We hypothesize that the metabolic changes in aged hearts make them less tolerant to acutely increased work and that thyroid hormone supplementation reverses these defects. METHODS: Studies were performed on young (Young, 4-6 months and aged (Old, 22-24 months C57/BL6 mice at standard (50 mmHg and high afterload (80 mmHg. Another aged group received thyroid hormone for 3 weeks (Old-TH, high afterload only. Function was measured in isolated working hearts along with substrate fractional contributions (Fc to the citric acid cycle (CAC using perfusate with (13C labeled lactate, pyruvate, glucose and unlabeled palmitate and insulin. RESULTS: Old mice maintained cardiac function under standard workload conditions, despite a marked decrease in unlabeled (presumably palmitate Fc and relatively similar individual carbohydrate contributions. However, old mice exhibited reduced palmitate oxidation with diastolic dysfunction exemplified by lower -dP/dT. Thyroid hormone abrogated the functional and substrate flux abnormalities in aged mice. CONCLUSION: The aged heart shows diminished ability to increase cardiac work due to substrate limitations, primarily impaired fatty acid oxidation. The heart accommodates slightly by increasing efficiency through oxidation of carbohydrate substrates. Thyroid hormone supplementation in aged mice significantly improves cardiac function potentially through restoration of fatty acid oxidation.

  20. High dose rate /sup 60/Co remote afterloading irradiation in cancer of the cervix in Haiti, 1977-1984

    Energy Technology Data Exchange (ETDEWEB)

    Streeter, O.E. Jr.; Goldson, A.L.; Chevallier, C.; Nibhanupudy, J.R.

    1988-06-01

    From 1977 through 1984, 293 previously untreated patients with biopsy proven carcinoma of the uterine cervix were treated by whole pelvis irradiation and high intensity 60Co remote afterloading (RAL) intrauterine tandem techniques in Haiti. The treatment results were analyzed retrospectively to evaluate the therapeutic results and prognostic factors of a strict protocol involving 40 Gy to the whole pelvis (2 Gy/day, 5 days/week). In addition, on the 5th day of the 3rd week, the first outpatient 60Co remote afterloading intracavitary insertion, delivering 7.5 Gy to point A with each insertion, repeated 3 times by a week separation for a total of 4 times. The total TDF for external beam plus RAL was 158 and 175 for early and late effects respectively. One hundred-four patients were evaluable after 1 year or more follow-up, with a median of 26.5 months. No evidence of disease (NED) by Stage at 1 year was: Stage I of 100% (3/3), Stage II of 82% (9/11), Stage III of 80% (47/59), and Stage IV of 58% (18/31). The post-therapeutic complication rate was 7.7%, with no fistulas or requirement of surgical intervention. Those with documented follow-up of at least 2 years (74 patients) had comparable survival to other high dose rate and low dose rate studies. This study shows that outpatient brachytherapy can be carried out without sophisticated and expensive equipment with minimal staff trained in radiation therapy. A detailed description of this outpatient RAL technique and results are described so that this method can be adapted to other developing and industrialized nations where cost containment is becoming a key issue.

  1. Human factors evaluation of remote afterloading brachytherapy. Supporting analyses of human-system interfaces, procedures and practices, training and organizational practices and policies. Volume 3

    International Nuclear Information System (INIS)

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the second, third, fourth, and fifth phases of the project, which involved detailed analyses of four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training practices and policies; and organizational practices and policies, respectively. Findings based on these analyses provided factual and conceptual support for the final phase of this project, which identified factors leading to human error in RAB. The impact of those factors on RAB performance was then evaluated and prioritized in terms of safety significance, and alternative approaches for resolving safety significant problems were identified and evaluated

  2. Human factors evaluation of remote afterloading brachytherapy. Supporting analyses of human-system interfaces, procedures and practices, training and organizational practices and policies. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L. [Pacific Science & Engineering Group, San Diego, CA (United States)] [and others

    1995-07-01

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the second, third, fourth, and fifth phases of the project, which involved detailed analyses of four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training practices and policies; and organizational practices and policies, respectively. Findings based on these analyses provided factual and conceptual support for the final phase of this project, which identified factors leading to human error in RAB. The impact of those factors on RAB performance was then evaluated and prioritized in terms of safety significance, and alternative approaches for resolving safety significant problems were identified and evaluated.

  3. Adaptive right ventricular performance in response to acutely increased afterload in a lamb model of congenital heart disease: evidence for enhanced Anrep effect.

    Science.gov (United States)

    Johnson, Rebecca C; Datar, Sanjeev A; Oishi, Peter E; Bennett, Stephen; Maki, Jun; Sun, Christine; Johengen, Michael; He, Youping; Raff, Gary W; Redington, Andrew N; Fineman, Jeffrey R

    2014-04-15

    Patients with pulmonary hypertension associated with congenital heart disease survive longer with preserved right ventricular (RV) function compared with those with primary pulmonary hypertension. The purpose of this study was to test the hypothesis that superior RV performance can be demonstrated, at baseline and when challenged with increased RV afterload, in lambs with chronic left-to-right cardiac shunts compared with control lambs. A shunt was placed between the pulmonary artery and the aorta in fetal lambs (shunt). RV pressure-volume loops were obtained 4 wk after delivery in shunt and control lambs, before and after increased afterload was applied using pulmonary artery banding (PAB). Baseline stroke volume (8.7 ± 1.8 vs. 15.8 ± 2.7 ml, P = 0.04) and cardiac index (73.0 ± 4.0 vs. 159.2 ± 25.1 ml·min(-1)·kg(-1), P = 0.02) were greater in shunts. After PAB, there was no difference in the change in cardiac index (relative to baseline) between groups; however, heart rate (HR) was greater in controls (168 ± 7.3 vs. 138 ± 6.6 beats/min, P = 0.01), and end-systolic elastance (Ees) was greater in shunts (2.63 vs. 1.31 × baseline, P = 0.02). Control lambs showed decreased mechanical efficiency (71% baseline) compared with shunts. With acute afterload challenge, both controls and shunts maintained cardiac output; however, this was via maladaptive responses in controls, while shunts maintained mechanical efficiency and increased contractility via a proposed enhanced Anrep effect-the second, slow inotropic response in the biphasic ventricular response to increased afterload, a novel finding in the RV. The mechanisms related to these physiological differences may have important therapeutic implications.

  4. Identifying afterloading PDR and HDR brachytherapy errors using real-time fiber-coupled Al2O3:C dosimetry and a novel statistical error decision criterion

    DEFF Research Database (Denmark)

    Kertzscher, Gustavo; Andersen, Claus Erik; Siebert, Frank-André;

    2011-01-01

    treatment errors, including interchanged pairs of afterloader guide tubes and 2–20mm source displacements, were monitored using a real-time fiber-coupled carbon doped aluminum oxide (Al2O3:C) crystal dosimeter that was positioned in the reconstructed tumor region. The error detection capacity was evaluated...... and position uncertainty 1–4mm). ResultsOut of 20 interchanged guide tube errors, time-resolved analysis identified 17 while fraction level analysis identified two. Channel and fraction level comparisons could leave 10mm dosimeter displacement errors unidentified. Dwell position dose rate comparisons correctly...... identified displacements ⩾5mm. ConclusionThis phantom study demonstrates that Al2O3:C real-time dosimetry can identify applicator displacements ⩾5mm and interchanged guide tube errors during PDR and HDR brachytherapy. The study demonstrates the shortcoming of a constant error criterion and the advantage...

  5. Volume and dose rate dependent (MDR-LDR Ir-192 afterloading interstitial brachytherapy) treatment optimisation, for squamouscell carcinoma of the lip

    International Nuclear Information System (INIS)

    Introduction: From 1/1/90 to 1/1/95, 53 patients with squamouscell carcinoma of the lip were treated by MDR or LDR Ir-192 afterloading interstitital brachytherapy. We compare the oncological and aesthetical results and sequelae depending on the volume and the dose rate. Material and methods: 53 patients, 41 men and 12 women, median age = 66y; 48 primary tumors (T1 = 26; T2 = 16; T3 = 6; N0 = 47; N1 = 1; M0 = 48) and 5 recurrencies; squamouscell carcinoma (grade 1 =45, g2 =6, g3 =2); clinical extension: buccal comissure=3, check =2, muscular =15, skin =7, lower and upper lip =1. Before radiotherapy, 28 biopsies and 25 excisional surgeries (19 with positive margins, 6 with negative margins) were performed. Brachytherapy was performed alone (dose 60-75 Gy BD85%) or as a boost (dose 10-30 Gy BD85%) associated with external beam (dose 46-50 Gy). MDR or LDR microselectron's afterloading was done after a computerised dosimetry (Paris System): treatment mean time = 30, 98 hours; mean volume = 10,2 cc (T1-T2 8, 61cc); Ir - 192 activity = range 0,7 - 4,792 mCi/cm; reference dose rate 45,6 - 290, 1 cGy/h. Results: 46 patients are alive without cancer, 1 died without responding, 6 died from non oncological diseases; 8 patients had recurrences (5 local, 3 nodal) but are alive. Mean follow-up 30,83 months (range 3-60m), mean DFS = 22,49 m (range 5-57m). Acute secondary effects: 30 radioepithelyties (grade 1 = 7, g2=23, g3=14), and 39 radiomucitis (g1=3; g2=23; g3=13); mean time for complete healing = 21, 66 days. Sequelae: moderate sclerosis of the skin =11, skin retraction = 1, hyperpigmentation2, depigmentation= 10, edema= 6, gingivitis= 7. Aesthetical results: good32; moderate= 18; bad= 2, very bad= 1 (uncontrolled tumor). Conclusions: The sequelae and aesthetical results are closely dependent on the treated volume and the dose rate, less dependent on the total dose, and independent on the Iridium activity. Complete healing time does not influence the late aesthetical results

  6. Bile duct sensitivity to high-dose-rate afterloading irradiation with iridium 192. Experimental investigations in pigs. Strahlenempfindlichkeit des gesunden Gallengangs bei High-dose-rate-Afterloadingbestrahlung mit Iridium 192. Experimentelle Untersuchungen am Schwein

    Energy Technology Data Exchange (ETDEWEB)

    Brambs, H.J. (Abt. Roentgendiagnostik und Roentgen- und Strahlentherapie, Universitaetsklinik Freiburg (Germany) Pathologisches Inst., Freiburg Univ. (Germany) Tierhygienisches Inst., Freiburg Univ. (Germany)); Freund, U. (Abt. Roentgendiagnostik und Roentgen- und Strahlentherapie, Universitaetsklinik Freiburg (Germany) Pathologisches Inst., Freiburg Univ. (Germany) Tierhygienisches Inst., Freiburg Univ. (Germany)); Bruggmoser, G. (Abt. Roentgendiagnostik und Roentgen- und Strahlentherapie, Universitaetsklinik Freiburg (Germany) Pathologisches Inst., Freiburg Univ. (Germany) Tierhygienisches Inst., Freiburg Univ. (Germany)); Laaff, H. (Abt. Roentgendiagnostik und Roentgen- und Strahlentherapie, Universitaetsklinik Freiburg (Germany) Pathologisches Inst., Freiburg Univ. (Germany) Tierhygienisches Inst., Freiburg Univ. (Germany)); Kluger, U.W. (Abt. Roentgendiagnostik und Roentgen- und Strahlentherapie, Universitaetsklinik Freiburg (Germany) Pathologisches Inst., Freiburg Univ. (Ger

    1993-12-01

    This animal study was designed to assess the tolerance of the normal bile duct to a single intraluminal high-dose-rate afterloading irradiation. This information is essential for treatment recommendations in irradiation therapy of malignant bile duct stenoses. In 16 pigs bile duct catheters were inserted surgically. Over these devices single intraductal doses of 7.5 Gy and 15 Gy were applied using an iridium-192 source. After a period of two to three months the bile ducts and the surrounding structures were investigated by means of cholangiography, angiography, and macropathological and histological investigations. A single intraductal dose of 7.5 Gy leads to a slightly scarred shrinkage of the bile duct with sclerosis and obliteration of the capillary vessels. Vasculitis and necrosis of the bile duct wall are still evident three months after irradiation. A single dose of 15 Gy leads to severe lesions with widespread necroses of the bile duct wall which tend to bleed, and result in a high degree of shrinkage of the bile duct. The radiation damage is most prevalent near the papilla and in the narrow segments near the liver. Single intraluminal high-dose-rate afterloading doses of 7.5 and 15 Gy cause significant lesions and complications at the bile ducts. As the intact bile duct is the Achilles heel of intraductal therapy, considerably lower single doses are recommended for a fractioned treatment. (orig.)

  7. Retreatment of recurrent carcinoma of the head and neck by afterloading interstitial 192Ir implant

    Energy Technology Data Exchange (ETDEWEB)

    Emami, B.; Marks, J.E.

    1983-10-01

    From January 1975 to December 1980, 25 patients with persistent or recurrent carcinomas of the head and neck were retreated for palliation at the Division of Radiation Oncology, Mallinckrodt Institute of Radiology. These patients had all undergone extensive previous treatment by surgery and/or radiation. All were retreated with 192Ir interstitial implant with or without external radiation and/or surgical excision. Of 25 patients, 13 had complete response (CR) and 6 had partial response for a follow-up period of 1 to 7 years. Of 13 patients with CR, 6 are alive with no evidence of disease (NED) and two died NED. Detailed results are presented and the new strategy for such patients is discussed.

  8. Pulmonary vascular mechanics: Important contributors to the increased right ventricular afterload of pulmonary hypertension

    OpenAIRE

    Wang, Zhijie; Chesler, Naomi C

    2013-01-01

    Chronic hypoxia causes pulmonary vasoconstriction and vascular remodeling, which lead to hypoxic pulmonary hypertension (HPH). HPH is associated with living at high altitudes and is a complication of many lung diseases, including chronic obstructive pulmonary disease, cystic fibrosis, and obstructive sleep apnea. Pulmonary vascular changes that occur with HPH include stiffening and narrowing of the pulmonary arteries that appear to involve all vascular cell types and sub-layers of the arteria...

  9. Left ventricular beat to beat performance in atrial fibrillation: dependence on contractility, preload, and afterload

    OpenAIRE

    Muntinga, H; Gosselink, A; Blanksma, P; De Kam, P J; van der Wall, E; Crijns, H.

    1999-01-01

    OBJECTIVE—To assess independent determinants of beat to beat variation in left ventricular performance during atrial fibrillation.
DESIGN—Prospective study.
SETTING—University hospital.
PATIENTS—Seven patients with chronic non-valvar atrial fibrillation.
INTERVENTIONS—Invasive and non-invasive haemodynamic variables were assessed using a non-imaging computerised nuclear probe, a balloon tipped flow directed catheter, and a non-invasive fingertip blood pressure measurement system linked to a p...

  10. Implementation of 'early alert system' area detector at patient from entrance in afterloading brachytherapy

    International Nuclear Information System (INIS)

    A system of area monitors to detect the involuntary exit of the radiation sources used in low dose rate deferred brachytherapy treatment is being implemented in all facilities in Chile. The first implementation of this system, named 'Early Alert', was 5 years ago as a complement to the administrative procedures and verification measures by the medical physics carried out through visual verifications and by means of portable radiation detectors. This detector of the system should be located preferentially at the exit of the treatment room at a height not smaller than two meters. This has resulted in an increase of facilities safety in this practice. (author)

  11. Effects of Endovascular Brachytherapy with 192Ir Afterloading System on Expression of Type Ⅰ Collagen after Angioplasty

    Institute of Scientific and Technical Information of China (English)

    向定成; 杨传红; 候友贤; 龚志华; 易绍东; 邱建

    2003-01-01

    Objectives To investi-gate the effect and mechanism of endovascularbrachytherapy with 192Ir on expression of type Ⅰ collagen, metalloproteinases - 1 (MMP - 1) and the tissueinhibitor (TIMP- 1 ) after angioplasty. MethodsRestenotic model of domestic microswine was em-ployed and the iliac arteries were randomized to radi-ation group ( n = 12), which were treated with 20 ~ 25Gy of 192Ir, and non - radiation group ( n = 36) afterangioplasty. The target vessels were harvested in theend of 3 months and 6 months after angioplasty. Im-munohistochemistry and in situ hybridization were usedto detect proteins of type Ⅰ collagen, MMP-1 andTIMP- 1, and mRNA expression of type Ⅰ collagen.Results The protein and mRNA of type Ⅰ collagen,the ratios of TIMP-1/MMP-1 were significantlylower iu radiation group than in non- radiation group( P < 0.05 or 0.01 ). The peak of transcription of typeⅠ collagen mRNA was at 6 months and 3 months in non-radiation group and radiation group respectively.Conclusions Endovascular brachytherapy with192Ir might modify the metabolism of extracellular ma-trix after angioplasty by inhibiting the synthesis of typeⅠ collagen and the activities of MMP - 1 and TIMP - 1.

  12. 体外加腔内照射治疗中晚期宫颈癌的远期疗效分析%Long-term results of cervix cancer (stage Ⅱ, stage Ⅲ) with external irradiation combination with afterloading radiotherapy

    Institute of Scientific and Technical Information of China (English)

    张小红; 许新华; 杨雅琴; 尚友兰; 蔡鑫; 薛峰

    2005-01-01

    目的:探讨体外加腔内照射治疗中晚期宫颈癌的临床疗效和不良反应.方法:选择我院1994年12月~1998年12月收治的117例Ⅱb、Ⅲ期宫颈癌患者进行60Co体外放射加192Ir源高剂量率后装腔内治疗,全盆外照射46~50Gy,腔内放疗4~6Gy/次,1次/周,A点总量30~40Gy,疗程为6~7周.结果:全组117例患者总的5年生存率为62.4%,其中Ⅱb期67.9%,Ⅲ期57.8%.盆腔内复发率42.1%,远处转移率57.9%.远期合并症放射性直肠炎6.8%,放射性膀胱炎5.1%,子宫积液0.9%,阴道狭窄35.9%.结论:体外加腔内照射治疗中晚期宫颈癌疗效肯定,其预后与诸多因素有关,如何降低远期并发症有待临床进一步研究.

  13. 宫颈癌低剂量率后装腔内放射治疗的远期疗效%Low-dose rate intracavitary afterloading radiotherapy for cancer of uterine cervix

    Institute of Scientific and Technical Information of China (English)

    张新; 王伊洵; 王慧明

    2002-01-01

    目的评价Gynatron低剂量率后装腔内治疗机的疗效.方法总结1980年4月~1986年6月间,应用Gynatron后装机配合60Co治疗机进行根治性放疗的136例宫颈癌,并与镭疗及高剂量率腔内后装治疗进行比较分析.结果除5例失访外,全部患者随访超过15年,随访率96.3%(131/136).Ⅱ、Ⅲ期的10年生存率分别为83.9%和43.2%.总10年生存率为63.5%.放射性直肠炎发生率为12.5 %(17/136),放射性膀胱炎发生率9.6% (13/136).结论 Gynatron低剂量率后装腔内治疗系统虽然有一定局限性,但仍可获得较满意的疗效;其治疗并发症患者可以接受,放射性直肠炎、放射性膀胱炎发生率高于镭疗,低于高剂量率腔内后装放疗.

  14. 联合放疗后前列腺MRI与组织病理学的相关性%MRT der Prostata nach kombinierter Radiotherapie (Afterloading und perkutan):Histopathologische Korrelation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    目的:研究局限性前列腺癌联合放疗(后装和经皮)后前列腺的MR成像和组织学表现的关系。评价MRI对病人随访的价值。   方法:对联合放疗结束后6~24个月的23例病人行1.5T的MRI检查。用轴位和冠状位T2W序列和静脉给Gd-DTPA前后作轴位T1W序列行前列腺成像。所有病人在MR检查后行四点或六点活组织检查。3例确有肿瘤残存的病人行补救性前列腺切除术。比较、分析MR片和活检结果或大块切片。   结果:T2W成像中纤维性变的外周呈低信号,肿瘤组织呈高信号。可显示直径在1cm以下的实性肿瘤。而多病灶的弥散性肿瘤残存则不显影。对比剂增强的T1W成像不提供更多信息。探测肿瘤残存的准确性为74%。   结论:联合放射后组织病理学的变化与T2W的MRI成像结果一致。MRI检查不可以替代常规的活检,只应在随访中PSA值上升时才使用,以判断局部手术的可行性。MRI检查这些病人的价值有待于进一步研究。 摘自Fortschr Rntgenstr 2000,172∶680-685

  15. 1251 seed calibration using afterloading equipment Seed Selectron. Practical solution to meet the recommendations of the AAPM; Calibracion de semillas de {sup 1}25I usando el equipo de carga difereida SeedSelectron. Solucion practica para cumplir las recomendaciones de la AAPM

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J.; Richart, J.; Perez-Garcia, J.; Guirado, D.; Ballester, F.; Rodriguez, S.; Santos, M.; Depiaggio, M.; Carmona, V.; Lliso, F.; Camacho, C.; Pujades, M. C.

    2011-07-01

    Seed Selectron is a system used in the after loader permanent implant brachytherapy seeds 1-125 interstitial prostate. Two aspects are critical when you can meet the recommendations of the AAPM: a practical difficulty to check the quantity of seed required, and the great uncertainty of all measured diodes. The purpose of this paper is to present a practical solution that has been adopted to implement the recommendations of the AAPM.

  16. The effect of adrenaline and high Ca2+ on the mechanical performance and oxygen consumption of the isolated perfused trout (Oncorhynchus mykiss) heart

    DEFF Research Database (Denmark)

    Rytter, Dorte; Gesser, Hans

    2007-01-01

    In heart muscle from mammals, catecholamines frequently evoke an oxygen waste and reduce efficiency. It was examined if this also applies to fish in which heart muscle activity is often restricted by oxygen availability. In the isolated perfused heart from rainbow trout, adrenaline (0.5 micro......M) increased power output by approximately 97%, when afterload was adjusted to maximum both before and after adrenaline addition, and by approximately 68%, when afterload remained at the maximum obtained before adrenaline addition. Oxygen consumption was enhanced by a similar amount (approximately 70%) in both...... situations. Hence, efficiency, i.e. power output/oxygen consumption, increased significantly from 25 to 30% for the heart always exposed to maximal afterload, whereas it stayed unchanged at 24% for the heart exposed to control afterload only. Adrenaline increases the Ca2+ activity participating in activation...

  17. The effect of open lung ventilation on right ventricular and left ventricular function in lung-lavaged pigs

    OpenAIRE

    Miranda, D.R.; Klompe, L; Cademartiri, Filippo; Haitsma, J.J.; Palumbo, Alessandro; Lachmann, Burkhard; Bogers, Ad; Gommers, Diederik; Takkenberg, Hanneke

    2006-01-01

    textabstractINTRODUCTION: Ventilation according to the open lung concept (OLC) consists of recruitment maneuvers, followed by low tidal volume and high positive end-expiratory pressure, aiming at minimizing atelectasis. The minimization of atelectasis reduces the right ventricular (RV) afterload, but the increased intrathoracic pressures used by OLC ventilation could increase the RV afterload. We hypothesize that when atelectasis is minimized by OLC ventilation, cardiac function is not affect...

  18. [New challenges to the treatment of cervical intraepithelial neoplasia].

    Science.gov (United States)

    Sun, J H

    2016-07-01

    Due to the progress of intracavitary afterloading technology and dosage of brachytherapy, a similar dose distribution as that of cervical conization can be achieved and can be applied to the treatment of cervical intraepithelial neoplasia (CIN), it is called "afterloading conization" . Being adjusted the radioactive source movement and weight, low exposure doses to the ovary, endometrium and vagina can be assured. So a high quality of life after treatment could be maintained and overcomes the shortcomings of cervical conization and hysterectomy, such as anesthesia, bleeding, over or insufficient treatment, early ovarian ageing and operative complications. PMID:27531273

  19. Characterization of a fiber-coupled Al2O3:C luminescence dosimetry system for online in vivo dose verification during Ir-192 brachytherapy

    DEFF Research Database (Denmark)

    Andersen, Claus Erik; Nielsen, Søren Kynde; Greilich, Steffen;

    2009-01-01

    A prototype of a new dose-verification system has been developed to facilitate prevention and identification of dose delivery errors in remotely afterloaded brachytherapy. The system allows for automatic online in vivo dosimetry directly in the tumor region using small passive detector probes...... outer diameter). The system was tested in the range from 0 to 4 Gy using a solid-water phantom, a Varian GammaMed Plus Ir-192 PDR afterloader, and dosimetry probes inserted into stainless-steel brachytherapy needles. The calibrated system was found to be linear in the tested dose range...

  20. Effects of arteriovenous fistulas on cardiac oxygen supply and demand

    NARCIS (Netherlands)

    Bos, W.J.W.; Zietse, R.; Wesseling, K.H.; Westerhof, N.

    1999-01-01

    Background. Arteriovenous (AV) fistulas used for hemodialysis access may affect cardiac load by increasing the preload while decreasing the afterload. In dogs, AV fistulas have also been shown to affect coronary perfusion negatively. We investigated the net effect of AV fistulas on cardiac oxygen su

  1. Cardiopulmonary interactions during mechanical ventilation in critically ill patients

    NARCIS (Netherlands)

    T.G.V. Cherpanath (Thomas); W.K. Lagrand (Wim); M.J. Schultz (Marcus); A.B.J. Groeneveld (Johan)

    2013-01-01

    textabstractCardiopulmonary interactions induced by mechan-ical ventilation are complex and only partly understood. Ap-plied tidal volumes and/or airway pressures largely mediate changes in right ventricular preload and afterload. Effects on left ventricular function are mostly secondary to changes

  2. Angina pectoris refractory for conventional therapy - Is neurostimulation a possible alternative treatment?

    NARCIS (Netherlands)

    Hautvast, RWM; DeJongste, MJL; TerHorst, GJ; Blanksma, PK; Lie, KI

    1996-01-01

    The treatment of angina pectoris as a symptom of coronary artery disease usually is focused on restoring the balance between oxygen demand and supply of the myocardium by administration of drugs interfering in heart rate, cardiac pre- and afterload, and coronary vascular tone. For nonresponders to d

  3. 10 CFR 35.605 - Installation, maintenance, adjustment, and repair.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Installation, maintenance, adjustment, and repair. 35.605... Installation, maintenance, adjustment, and repair. (a) Only a person specifically licensed by the Commission or an Agreement State shall install, maintain, adjust, or repair a remote afterloader unit,...

  4. The haemodynamic effects of nifedipine, verapamil and diltiazem in patients with coronary artery disease. A review

    NARCIS (Netherlands)

    A.L. Soward; G.L.J. Vanhaleweyk; P.W.J.C. Serruys (Patrick)

    1986-01-01

    textabstractOf the 3 most widely used calcium antagonists--nifedipine, verapamil and diltiazem--nifedipine is the most potent arterial vasodilator. Increases in cardiac output and coronary blood flow following nifedipine administration result in part from the afterload reduction. Reflex adrenergic s

  5. Internal irradiation of the carcinoma of the prostate. Interview with Prof. Dr. S. Loening. Interne Bestrahlung des Prostatakarzinoms. Nachgefragt bei Prof. Dr. S. Loening

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-01-01

    A procedure for the radiologic treatment of the carcinoma of the prostate has recently been developed by clinicians of the 'Charite' and Berlin University Hospital at Steglitz. In this procedure, access to the carcinoma for spiking with tags and subsequent irradiation using the afterloading method is gained from the perineum. (orig.).

  6. Internal irradiation of the carcinoma of the prostate

    International Nuclear Information System (INIS)

    A procedure for the radiologic treatment of the carcinoma of the prostate has recently been developed by clinicians of the 'Charite' and Berlin University Hospital at Steglitz. In this procedure, access to the carcinoma for spiking with tags and subsequent irradiation using the afterloading method is gained from the perineum. (orig.)

  7. Force-length relations in isolated intact cardiomyocytes subjected to dynamic changes in mechanical load.

    Science.gov (United States)

    Iribe, Gentaro; Helmes, Michiel; Kohl, Peter

    2007-03-01

    We developed a dynamic force-length (FL) control system for single intact cardiomyocytes that uses a pair of compliant, computer-controlled, and piezo translator (PZT)-positioned carbon fibers (CF). CF are attached to opposite cell ends to afford dynamic and bidirectional control of the cell's mechanical environment. PZT and CF tip positions, as well as sarcomere length (SL), are simultaneously monitored in real time, and passive/active forces are calculated from CF bending. Cell force and length were dynamically adjusted by corresponding changes in PZT position, to achieve isometric, isotonic, or work-loop style contractions. Functionality of the technique was assessed by studying FL behavior of guinea pig intact cardiomyocytes. End-diastolic and end-systolic FL relations, obtained with varying preload and/or afterloads, were near linear, independent of the mode of contraction, and overlapping for the range of end-diastolic SLs tested (1.85-2.05 micro m). Instantaneous elastance curves, obtained from FL relation curves, showed an afterload-dependent decrease in time to peak elastance and slowed relaxation with both increased preload and afterload. The ability of the present system to independently and dynamically control preload, afterload, and transition between end-diastolic and end-systolic FL coordinates provides a valuable extension to the range of tools available for the study of single cardiomyocyte mechanics, to foster its interrelation with whole heart pathophysiology. PMID:17098830

  8. Contraction and relaxation of isolated cardiac myocytes of the frog under varying mechanical loads.

    Science.gov (United States)

    Parikh, S S; Zou, S Z; Tung, L

    1993-02-01

    The mechanics of cardiac systole and relaxation have been studied primarily at the level of the whole heart or intact muscle. End-systolic pressure-volume relations of frog hearts have been found to be load dependent, whereas those of the mammal are relatively load independent. On the other hand, myocardial relaxation as studied at the muscle level is load independent in the frog but markedly load dependent in the mammal. Interpretation of these studies is complicated because of the unknown contribution of extracellular connective tissue, neurohumoral factors, and, in the case of the heart, the complex chamber geometry. Therefore, it is valuable to study cardiac mechanics at the level of the basic unit of contractile activity--the isolated myocyte. The goal of this study was to subject isolated frog cardiomyocytes to mechanical loading paradigms that mimic those presented to the cells within the heart. In the first part of this study, the afterload and preload of contracting cells were varied to study their effects on the end-systolic force-length relation, which was consistently found to be load independent over the range of isotonic shortening tested (typically 5%). We also investigated the force-length-time response of the cells to test the concept of the heart behaving as a time-varying elastance. Our results suggest that in this regard the frog myocyte behaves like mammalian muscle, and they are consistent with the presence of a small viscosity within the cell. We conclude that the tissue structure of the frog heart may contribute to disparity in mechanical behavior at the different structural levels. In the second part of this study, we subjected isolated frog cardiomyocytes to four different loading paradigms to test the hypothesis that myocardial relaxation in the frog is independent of load. These sequences consisted of afterloaded contractions followed by conventional isotonic-isometric relaxation (ACCR) or afterloaded contractions followed by

  9. Reduction of regurgitation in aortic insufficiency by inhibition of the renin/angiotensin conversion enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Reske, S.N.; Heck, I.; Mattern, H.

    1984-10-01

    The effect of captopril-mediated afterload reduction on regurgitation was investigated in 10 patients with aortic insufficiency. Regurgitation was quantitated by the regurgitation fraction and the relation of regurgitant volume to end-diastolic volume, which were derived from gated radionuclide ventriculography. 19 patients with coronary artery disease and no evidence of valvular heart disease served as controls. In patients with coronary artery disease no significant reguration was found. In patients with aortic regurgitation the blood concentration of angiotensin I increased whereas that of angiotensin II decreased significantly after captopril-medication; thus, the conversion of angiotensin I to II was reduced to about 50% of the control value. Whereas blood pressure and heart rate did not change significantly, the regurgitation fraction and the normalized regurgitant volume were significantly reduced. The ejection fraction remained essentially unchanged. These findings suggest a favorable influence of captopril-induced afterload reduction on hemodynamics in aortic regurgitation.

  10. In situ cardiac perfusion reveals interspecific variation of intraventricular flow separation in reptiles.

    Science.gov (United States)

    Joyce, William; Axelsson, Michael; Altimiras, Jordi; Wang, Tobias

    2016-07-15

    The ventricles of non-crocodilian reptiles are incompletely divided and provide an opportunity for mixing of oxygen-poor blood and oxygen-rich blood (intracardiac shunting). However, both cardiac morphology and in vivo shunting patterns exhibit considerable interspecific variation within reptiles. In the present study, we develop an in situ double-perfused heart approach to characterise the propensity and capacity for shunting in five reptile species: the turtle Trachemys scripta, the rock python Python sebae, the yellow anaconda Eunectes notaeus, the varanid lizard Varanus exanthematicus and the bearded dragon Pogona vitticeps To simulate changes in vascular bed resistance, pulmonary and systemic afterloads were independently manipulated and changes in blood flow distribution amongst the central outflow tracts were monitored. As previously demonstrated in Burmese pythons, rock pythons and varanid lizards exhibited pronounced intraventricular flow separation. As pulmonary or systemic afterload was raised, flow in the respective circulation decreased. However, flow in the other circulation, where afterload was constant, remained stable. This correlates with the convergent evolution of intraventricular pressure separation and the large intraventricular muscular ridge, which compartmentalises the ventricle, in these species. Conversely, in the three other species, the pulmonary and systemic flows were strongly mutually dependent, such that the decrease in pulmonary flow in response to elevated pulmonary afterload resulted in redistribution of perfusate to the systemic circuit (and vice versa). Thus, in these species, the muscular ridge appeared labile and blood could readily transverse the intraventricular cava. We conclude that relatively minor structural differences between non-crocodilian reptiles result in the fundamental changes in cardiac function. Further, our study emphasises that functionally similar intracardiac flow separation evolved independently in

  11. In situ cardiac perfusion reveals interspecific variation of intraventricular flow separation in reptiles.

    Science.gov (United States)

    Joyce, William; Axelsson, Michael; Altimiras, Jordi; Wang, Tobias

    2016-07-15

    The ventricles of non-crocodilian reptiles are incompletely divided and provide an opportunity for mixing of oxygen-poor blood and oxygen-rich blood (intracardiac shunting). However, both cardiac morphology and in vivo shunting patterns exhibit considerable interspecific variation within reptiles. In the present study, we develop an in situ double-perfused heart approach to characterise the propensity and capacity for shunting in five reptile species: the turtle Trachemys scripta, the rock python Python sebae, the yellow anaconda Eunectes notaeus, the varanid lizard Varanus exanthematicus and the bearded dragon Pogona vitticeps To simulate changes in vascular bed resistance, pulmonary and systemic afterloads were independently manipulated and changes in blood flow distribution amongst the central outflow tracts were monitored. As previously demonstrated in Burmese pythons, rock pythons and varanid lizards exhibited pronounced intraventricular flow separation. As pulmonary or systemic afterload was raised, flow in the respective circulation decreased. However, flow in the other circulation, where afterload was constant, remained stable. This correlates with the convergent evolution of intraventricular pressure separation and the large intraventricular muscular ridge, which compartmentalises the ventricle, in these species. Conversely, in the three other species, the pulmonary and systemic flows were strongly mutually dependent, such that the decrease in pulmonary flow in response to elevated pulmonary afterload resulted in redistribution of perfusate to the systemic circuit (and vice versa). Thus, in these species, the muscular ridge appeared labile and blood could readily transverse the intraventricular cava. We conclude that relatively minor structural differences between non-crocodilian reptiles result in the fundamental changes in cardiac function. Further, our study emphasises that functionally similar intracardiac flow separation evolved independently in

  12. EFFECT OF SODIUM-POTASSIUM INTAKE ON ARTERIAL STIFFNESS

    OpenAIRE

    J GOLSHAHI; Z MOBADI; N. Zamani

    2001-01-01

    Introduction. Hypertension is one of the most common causes of cardiovascular problems in our society. Diet is the cheapest and the most accessible method of blood pressure (BP) control. BP is associated with arterial stiffness which affects cardiac afterload. This study evaluate the effect of diertary Na and K on vascular compliance. Methods. We selected ninty six patients referred to Isfahan cardovascular Research center (affiliated to IUMSHS). Inclusion criteria were mild hypertension...

  13. Allopurinol Benefits Left Ventricular Mass and Endothelial Dysfunction in Chronic Kidney Disease

    OpenAIRE

    Kao, Michelle P.; Ang, Donald S.; Gandy, Stephen J.; Nadir, M. Adnan; Houston, J. Graeme; Lang, Chim C; Struthers, Allan D

    2011-01-01

    Allopurinol ameliorates endothelial dysfunction and arterial stiffness among patients without chronic kidney disease (CKD), but it is unknown if it has similar effects among patients with CKD. Furthermore, because arterial stiffness increases left ventricular afterload, any allopurinol-induced improvement in arterial compliance might also regress left ventricular hypertrophy (LVH). We conducted a randomized, double-blind, placebo-controlled, parallel-group study in patients with stage 3 CKD a...

  14. Pathophysiology of pulmonary hypertension in acute lung injury

    OpenAIRE

    Price, Laura C.; Mcauley, Danny F.; Marino, Philip S; Finney, Simon J; Griffiths, Mark J.; Wort, Stephen John

    2012-01-01

    Acute lung injury (ALI) and acute respiratory distress syndrome are characterized by protein rich alveolar edema, reduced lung compliance, and acute severe hypoxemia. A degree of pulmonary hypertension (PH) is also characteristic, higher levels of which are associated with increased morbidity and mortality. The increase in right ventricular (RV) afterload causes RV dysfunction and failure in some patients, with associated adverse effects on oxygen delivery. Although the introduction of lung p...

  15. What role does the right side of the heart play in circulation?

    OpenAIRE

    Cecconi, Maurizio; Johnston, Edward; Rhodes, Andrew

    2006-01-01

    Right ventricular failure (RVF) is an underestimated problem in intensive care. This review explores the physiology and pathophysiology of right ventricular function and the pulmonary circulation. When RVF is secondary to an acute increase in afterload, the picture is one of acute cor pulmonale, as occurs in the context of acute respiratory distress syndrome, pulmonary embolism and sepsis. RVF can also be caused by right myocardial dysfunction. Pulmonary arterial catheterization and echocardi...

  16. Simulation of the Frank-Starling Law of the Heart

    OpenAIRE

    Samo Ribarič; Marjan Kordaš

    2012-01-01

    We developed a lumped parameter, computer-based model of an equivalent electronic circuit for a one-atrium one-ventricle (frog) heart attached to a vascular circuit, to simulate a basic concept of cardiovascular physiology, the Frank-Starling Law of the Heart. A series of simulations was performed, to observe changes in cardiovascular variables (e.g., arterial pressure, ventricular volume, and valve flows) if either preload or afterload was increased. The simulated data agreed qualitatively, ...

  17. Pulmonary Vascular and Right Ventricular Reserve in Patients With Normalized Resting Hemodynamics After Pulmonary Endarterectomy

    OpenAIRE

    Claessen, Guido; La Gerche, Andre; Dymarkowski, Steven; Claus, Piet; Delcroix, Marion; Heidbuchel, Hein

    2015-01-01

    Background-Patients with normalized mean pulmonary artery pressure (mPAP) after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) do not always regain normal exercise capacity. We evaluated right ventricular function, its interaction with both pulsatile and resistive afterload, and the effect of sildenafil during exercise in these patients. Methods and Results-Fourteen healthy controls, 15 CTEPH patients, and 7 patients with normalized resting mPAP (

  18. In vivo and in vitro measurements of pulmonary arterial stiffness: A brief review

    OpenAIRE

    Tian, Lian; Chesler, Naomi C.

    2012-01-01

    During the progression of pulmonary hypertension (PH), proximal pulmonary arteries (PAs) undergo remodeling such that they become thicker and the elastic modulus increases. Both of these changes increase the vascular stiffness. The increase in pulmonary vascular stiffness contributes to increased right ventricular (RV) afterload, which causes RV hypertrophy and eventually failure. Studies have found that proximal PA stiffness or its inverse, compliance, is strongly related to morbidity and mo...

  19. Occupational monitoring intracavitary radium therapy

    International Nuclear Information System (INIS)

    The working exposure conditions in two big hospital in Rio de Janeiro, Brazil, that use 226Ra tubes in preloaded applicators were evaluated. The effective dose equivalents were obtained and the results of the investigation lead to the conclusion that it can be reduced to lower and reasonably achievable Le vels with good professional training, correct working conditions and afterloading techniques. (M.C.K.)

  20. Fractionation and protaction in the intracavitary local irradiation of gynecological tumors

    International Nuclear Information System (INIS)

    The difficulties of dosage and temporary adaptation of the short time afterloading therapy to an optimal healing result combined with a minimum of side-effects in radiotherapy of gynecological tumors are still not solved yet. Only a therapy scheme which parts from the good results of the long term radium therapy in combination with an adequately dosed and distributed deep therapy has a chance to replace the radium therapy of gynecological tumors in the long run. (orig.)

  1. Approaching a new age in Duchenne muscular dystrophy treatment

    OpenAIRE

    Wagner, Kathryn R.

    2008-01-01

    Duchenne muscular dystrophy is the most common and severe form of muscular dystrophy. The cornerstones of current treatment include corticosteroids for skeletal muscle weakness, afterload reduction for cardiomyopathy, and noninvasive ventilation for respiratory failure. With these interventions, patients are walking and living longer. However, the current status is still far from adequate. Increased private and federal funding of studies in Duchenne muscular dystrophy has led to a large numbe...

  2. In Vitro Testing of a Novel Blood Pump Designed for Temporary Extracorporeal Support

    OpenAIRE

    Spurlock, DJ; Ranney, DN; Fracz, E; Mazur,; Bartlett, RH; Haft, JW

    2012-01-01

    Extracorporeal blood pumps are used as temporary ventricular assist devices or for extracorporeal membrane oxygenation. The ideal pump would be intrinsically self-regulating, carry no risk of cavitation or excessive inlet suction, be afterload insensitive, and valveless thus reducing thrombogenicity. Currently used technology, including roller, centrifugal, and pneumatic pulsatile pumps, does not meet these requirements. We studied a non-occlusive peristaltic pump (M-Pump) in two mock circula...

  3. Right Ventricular Dysfunction in Chronic Lung Disease

    OpenAIRE

    Kolb, Todd M.; Hassoun, Paul M.

    2012-01-01

    Right ventricular dysfunction arises in chronic lung disease when chronic hypoxemia and disruption of pulmonary vascular beds contribute to increase ventricular afterload, and is generally defined by hypertrophy with preserved myocardial contractility and cardiac output. Although the exact prevalence is unknown, right ventricular hypertrophy appears to be a common complication of chronic lung disease, and more frequently complicates advanced lung disease. Right ventricular failure is rare, ex...

  4. Mechanics and Function of the Pulmonary Vasculature: Implications for Pulmonary Vascular Disease and Right Ventricular Function

    OpenAIRE

    Lammers, Steven; Scott, Devon; Hunter, Kendall; Tan, Wei; Shandas, Robin; Stenmark, Kurt R.

    2012-01-01

    The relationship between cardiac function and the afterload against which the heart muscle must work to circulate blood throughout the pulmonary circulation is defined by a complex interaction between many coupled system parameters. These parameters range broadly and incorporate system effects originating primarily from three distinct locations: input power from the heart, hydraulic impedance from the large conduit pulmonary arteries, and hydraulic resistance from the more distal microcircula...

  5. Pulmonary Edema

    OpenAIRE

    Tanser, Paul H.

    1981-01-01

    The physician who deals with pulmonary edema from a pathophysiologic basis will seldom make a diagnostic or therapeutic error. Recent additions to preload and afterload therapy have greatly helped in the emergency and ambulatory treatment of pulmonary edema due to left heart failure. Careful follow-up and patient self-monitoring are the most effective means of reducing hospitalization of chronic heart failure patients.

  6. Rise Above: Muscle Ring-Finger-1 (MURF1) Regulation of Cardiomyocyte Size and Energy Metabolism

    OpenAIRE

    Patterson, Cam; Willis, Monte S.; Portbury, Andrea

    2011-01-01

    Cardiac hypertrophy develops in response to increases in afterload, most commonly as the result of hypertension. When left untreated, cardiac hypertrophy commonly progresses to heart failure, one of the leading causes of death in the US. A number of studies have shown that reversing cardiac hypertrophy can decrease the progression to heart failure. However, the treatments now used to decrease cardiac hypertrophy have had limited success. Our laboratory has found that the novel muscle-specific...

  7. Influence of respiratory variations on right ventricular function.

    OpenAIRE

    Caplin, J L; Flatman, W D; Dyke, L; Wiseman, M N; Dymond, D S

    1989-01-01

    Respiratory effort during inspiration, expiration, and the Valsalva manoeuvre changes right ventricular preload and afterload. On inspiration these changes should improve systolic emptying of a larger end diastolic volume and so increase the ejection fraction, whereas on expiration the reverse should be true. The resting right ventricular ejection fraction was measured by first pass radionuclide angiography with gold-195m (half life 30.5 s) in 17 individuals at maximal inspiration and expirat...

  8. [A novel serial port auto trigger system for MOSFET dose acquisition].

    Science.gov (United States)

    Luo, Guangwen; Qi, Zhenyu

    2013-01-01

    To synchronize the radiation of microSelectron-HDR (Nucletron afterloading machine) and measurement of MOSFET dose system, a trigger system based on interface circuit was designed and corresponding monitor and trigger program were developed on Qt platform. This interface and control system was tested and showed stable operate and reliable work. This adopted serial port detect technique may expand to trigger application of other medical devices. PMID:23668038

  9. Computer calculations in interstitial seed therapy: I. Radiation treatment planning

    International Nuclear Information System (INIS)

    Interstitial seed therapy computers can be used for radiation treatment planning and for dose control after implantation. In interstitial therapy with radioactive seeds there are much greater differences between planning and carrying out radiation treatment than in teletherapy with cobalt-60 or X-rays. Because of the short distance between radioactive sources and tumour tissue, even slight deviations from the planned implantation geometry cause considerable dose deviations. Furthermore, the distribution of seeds in an actual implant is inhomogeneous. During implantation the spatial distribution of seeds cannot be examined exactly, though X-rays are used to control the operation. The afterloading technique of Henschke allows a more exact implantation geometry, but I have no experience of this method. In spite of the technical difficulty of achieving optimum geometry, interstitial therapy still has certain advantages when compared with teletherapy: the dose in the treated volume can be kept smaller than in teletherapy, the radiation can be better concentrated in the tumour volume, the treatment can be restricted to one or two operations, and localized inoperable tumours may be cured more easily. The latter may depend on an optimal treatment time, a relatively high tumour dose and a continuous exponentially decreasing dose rate during the treatment time. A disadvantage of interstitial therapy is the high personnel dose, which may be reduced by the afterloading technique of Henschke (1956). However, the afterloading method requires much greater personnel and instrumental expense than free implantation of radiogold seeds and causes greater trauma for the patient

  10. The right ventricle in pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Robert Naeije

    2014-12-01

    Full Text Available Pulmonary arterial hypertension (PAH is a right heart failure syndrome. In early-stage PAH, the right ventricle tends to remain adapted to afterload with increased contractility and little or no increase in right heart chamber dimensions. However, less than optimal right ventricular (RV–arterial coupling may already cause a decreased aerobic exercise capacity by limiting maximum cardiac output. In more advanced stages, RV systolic function cannot remain matched to afterload and dilatation of the right heart chamber progressively develops. In addition, diastolic dysfunction occurs due to myocardial fibrosis and sarcomeric stiffening. All these changes lead to limitation of RV flow output, increased right-sided filling pressures and under-filling of the left ventricle, with eventual decrease in systemic blood pressure and altered systolic ventricular interaction. These pathophysiological changes account for exertional dyspnoea and systemic venous congestion typical of PAH. Complete evaluation of RV failure requires echocardiographic or magnetic resonance imaging, and right heart catheterisation measurements. Treatment of RV failure in PAH relies on: decreasing afterload with drugs targeting pulmonary circulation; fluid management to optimise ventricular diastolic interactions; and inotropic interventions to reverse cardiogenic shock. To date, there has been no report of the efficacy of drug treatments that specifically target the right ventricle.

  11. Cardiac factors in orthostatic hypotension

    Science.gov (United States)

    Löllgen, H.; Dirschedl, P.; Koppenhagen, K.; Klein, K. E.

    Cardiac function is determined by preload, afterload, heart rate and contractility. During orthostatic stress, the footward blood shift is compensated for by an increase of afterload. LBNP is widely used to analyze effects of volume displacement during orthostatic stress. Comparisons of invasive ( right heart catheterization) and non-invasive approach (echocardiography) yielded similar changes. Preload and afterload change with graded LBNP, heart rate increases, and stroke volume and cardiac output decrease. Thus, the working point on the left ventricular function curve is shifted to the left and downward, similar to hypovolemia. However, position on the Frank-Starling curve, the unchanged ejection fraction, and the constant Vcf indicate a normal contractile state during LBNP. A decrease of arterial oxygen partial pressure during LBNP shwos impaired ventilation/perfusion ratio. Finally, LBNP induced cardiac and hemodynamic changes can be effectively countermeasured by dihydroergotamine, a potent venoconstrictor. Comparison of floating catheter data with that of echocardiography resulted in close correlation for cardiac output and stroke volume. In addition, cardiac dimensions changed in a similar way during LBNP. From our findings, echocardiography as a non-invasive procedure can reliably used in LBNP and orthostatic stress tests. Some informations can be obtained on borderline values indicating collaps or orthostatic syncope. Early fainters can be differentiated from late fainters by stroke volume changes.

  12. Myocardial performance index is sensitive to changes in cardiac contractility, but is also affected by vascular load condition.

    Science.gov (United States)

    Uemura, Kazunori; Kawada, Toru; Zheng, Can; Li, Meihua; Shishido, Toshiaki; Sugimachi, Masaru

    2013-01-01

    Myocardial performance index (MPI), or Tei index, is measured by Doppler echocardiography in clinical practice. MPI has been shown to be useful in evaluating left ventricular (LV) performance and predicting prognosis in cardiac patients. However, the effects of LV load and contractile states on MPI remain to be thoroughly investigated. In 14 anesthetized dogs, we obtained LV pressure-volume relationship with use of sonomicrometry and catheter-tip manometry. MPI was determined from the time derivative of LV volume and pressure. LV end-systolic pressure-volume ratio (Ees'), effective arterial elastance (Ea) and LV end-diastolic volume (Ved) were used as indices of LV contractility, afterload and preload, respectively. Hemodynamic conditions were varied over wide ranges [heart rate (HR), 66-192 bpm; mean arterial pressure, 71-177 mmHg] by infusing cardiovascular agents, by inducing ischemic heart failure and by electrical atrial pacing. Multiple linear regression analysis of pooled data (66 data sets) indicated that MPI (0.6-1.8) significantly correlated with Ees' [1.5-17.5 mmHg · ml(-1), pVed (11-100 ml, p0.1). Theoretical analysis also indicated that MPI decreases following the increases in LV contractility and in preload, while it increases in response to an increase in LV afterload. We conclude that MPI sensitively detects changes in LV contractility. However, MPI is also affected by changes in LV afterload and preload. PMID:24109782

  13. Loss of an iridium-192 source and therapy misadministration at Indiana Regional Cancer Center, Indiana, Pennsylvania, on November 16, 1992

    International Nuclear Information System (INIS)

    On December 1, 1992, the Indiana Regional Cancer Center reported to the US Nuclear Regulatory Commission's (NRC) Region I that they believed a 1.37 E + 11 becquerel (3.7-curie) iridium-192 source from their Omnitron 2000 high dose rate remote brachytherapy afterloader had been found at a biohazard waste transfer station in Carnegie, Pennsylvania. After notifying the NRC, this cancer center, one of several operated by the licensee, Oncology Services Corporation, retrieved the source, and Region I dispatched an inspector and a supervisor to investigate the event. The source was first detected when it triggered radiation alarms at a waste incinerator facility in. Warren, Ohio. The licensee informed the NRC that the source wire had apparently broken during treatment of a patient on November 16, 1992, leaving the source in the patient. On the basis of the seriousness of the incident, the NRC elevated its response to an Incident Investigation. The Incident Investigation Team initiated its investigation on December 3, 1992. The investigation team concluded that the patient received a serious misadministration and died on November 21, 1992, and that over 90 individuals were exposed to radiation from November 16 to December 1, 1992. In a press release dated January 26, 1993, the Indiana County Coroner stated that the cause of death listed in the official autopsy report was ''Acute Radiational Exposure and Consequences Thereof'' An almost identical source wire failure occurred with an afterloader in Pittsburgh, Pennsylvania, on December 7, 1992, but with minimal radiological consequences. This incident was included in the investigation. This report discusses the Omnitron 2000 high dose rate afterloader source-wire failure, the reasons why the failure was not detected by Indiana Regional Cancer Center, the potential consequences to the patient, the estimated radiological doses to workers and the public, and regulatory aspects associated with this incident

  14. In-phantom dosimetric measurements as quality control for brachytherapy. System check and constancy check; Messungen im Festkoerperphantom als Qualitaetskontrolle in der Brachytherapie. Systempruefung und Konstanzpruefung

    Energy Technology Data Exchange (ETDEWEB)

    Kollefrath, Michael; Bruggmoser, Gregor; Nanko, Norbert; Gainey, Mark [Universitaetsklinik Freiburg (Germany). Klinik fuer Strahlenheilkunde

    2015-09-01

    In brachytherapy dosimetric measurements are difficult due to the inherent dose-inhomogeneities. Typically in routine clinical practice only the nominal dose rate is determined for computer controlled afterloading systems. The region of interest lies close to the source when measuring the spatial dose distribution. In this region small errors in the positioning of the detector, and its finite size, lead to large measurement uncertainties that exacerbate the routine dosimetric control of the system in the clinic. The size of the measurement chamber, its energy dependence, and the directional dependence of the measurement apparatus are the factors which have a significant influence on dosimetry. Although ionisation chambers are relatively large, they are employed since similar chambers are commonly found on clinical brachytherapy units. The dose is determined using DIN 6800 [11] since DIN 6809-2 [12], which deals with dosimetry in brachytherapy, is antiquated and is currently in the process of revision. Further information regarding dosimetry for brachytherapy can be found in textbooks [1] and [2]. The measurements for this work were performed with a HDR (High-Dose-Rate) {sup 192}Ir source, type mHDR V2, and a Microselectron Afterloader V2 both from Nucletron/Elekta. In this work two dosimetric procedures are presented which, despite the aforemention difficulties, should assist in performing checks of the proper operation of the system. The first is a system check that measures the dose distribution along a line and is to be performed when first bringing the afterloader into operation, or after significant changes to the system. The other is a dosimetric constancy check, which with little effort can be performed monthly or weekly. It simultaneously verifies the positioning of the source at two positions, the functionality of the system clock and the automatic re-calculation of the source activity.

  15. Feasibility of combined operation and perioperative intensity-modulated brachytherapy of advanced/recurrent malignancies involving the skull base

    Energy Technology Data Exchange (ETDEWEB)

    Strege, R.J.; Eichmann, T.; Mehdorn, H.M. [University Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Neurosurgery; Kovacs, G.; Niehoff, P. [University Hospital Schleswig-Holstein, Kiel (Germany). Interdisciplinary Brachytherapy Center; Maune, S. [University Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Otolaryngology; Holland, D. [University Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Ophthalmology

    2005-02-01

    Purpose: To assess the technical feasibility and toxicity of combined operation and perioperative intensity-modulated fractionated interstitial brachytherapy (IMBT) in advanced-stage malignancies involving the skull base with the goal of preserving the patients' senses of sight. Patients and Methods: This series consisted of 18 consecutive cases: ten patients with paranasal sinus carcinomas, five with sarcomas, two with primitive neuroectodermal tumors (PNETs), and one with parotid gland carcinoma. After, in most cases, subtotal surgical resection (R1-R2: carried out so that the patients' senses of sight were preserved), two to twelve (mean five) afterloading plastic tubes were placed into the tumor bed. IMBT was performed with an iridium-192 stepping source in pulsed-dose-rate/high-dose-rate (PDR/HDR) afterloading technique. The total IMBT dose, ranging from 10 to 30 Gy, was administered in a fractionated manner (3-5 Gy/day, 5 days/week). Results: Perioperative fractionated IMBT was performed in 15 out of 18 patients and was well tolerated. Complications that partially prevented or delayed IMBT in some cases included cerebrospinal fluid leakage (twice), meningitis (twice), frontal brain syndrome (twice), afterloading tube displacement (twice), seizure (once), and general morbidity (once). No surgery- or radiation-induced injuries to the cranial nerves or eyes occurred. Median survival times were 33 months after diagnosis and 16 months after combined operation and IMBT. Conclusion: Perioperative fractionated IMBT after extensive but vision-preserving tumor resection seems to be a safe and well-tolerated treatment of advanced/recurrent malignancies involving the skull base. These preliminary state suggest that combined operation and perioperative fractionated IMBT is a palliative therapeutic option in the management of fatal malignancies involving the base of the skull, a strategy which leaves the patients' visual acuity intact. (orig.)

  16. High dose brachytherapy in pediatric oncology; Braquiterapia com alta taxa de dose em oncologia pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Ferrigno, Robson; Codjaian, Osanna Esther; Novaes, Paulo Eduardo R.S.; Trippe, Nivaldo [Fundacao Antonio Prudente, Sao Paulo, SP (Brazil). Hospital A.C. Camargo. Dept. de Radioterapia

    1995-05-01

    Brachytherapy is a kind of radiotherapy that has been used in the multidisciplinary approach of some pediatric tumors, such as soft tissue sarcomas of the extremities, head and neck and urogenital tract. Recent technological advances in this area lead to development of computerized high dose rate remote afterloading brachytherapy. This type of treatment has some advantages compared to low dose rate brachytherapy traditionally used. This article describes not only the characteristics and advantages of this kind of treatment, but also the preliminary results of the first seven children treated with high dose rate at the Hospital A.C.Camargo. (author) 10 refs., 8 figs.

  17. The application of Geant4 simulation code for brachytherapy treatment

    CERN Document Server

    Agostinelli, S; Garelli, S; Paoli, G; Nieminen, P; Pia, M G

    2000-01-01

    Brachytherapy is a radiotherapeutic modality that makes use of radionuclides to deliver a high radiation dose to a well-defined volume while sparing surrounding healthy structures. At the National Institute for Cancer Research of Genova a High Dose Rate remote afterloading system provides Ir(192) endocavitary brachytherapy treatments. We studied the possibility to use the Geant4 Monte Carlo simulation toolkit in brachytherapy for calculation of complex physical parameters, not directly available by experiment al measurements, used in treatment planning dose deposition models.

  18. Precision of RL/OSL medical dosimetry with fiber-coupled Al2O3:C: Influence of readout delay and temperature variations

    DEFF Research Database (Denmark)

    Andersen, C.E.; Edmund, J.M.; Damkjaer, S.M.S.

    2010-01-01

    Carbon-doped aluminum oxide (Al2O3:C) crystals attached to 15 m optical fiber cables can be used for online in vivo dosimetry during, for example, remotely afterloaded brachytherapy. Radioluminescence (RL) is generated spontaneously in Al2O3:C during irradiation, and this scintillator-like signal....... The prime objective of this work was to assess the influence of delay between irradiation and optical stimulation on such measurements. A secondary objective was to demonstrate that previously determined RL/OSL temperature coefficients are independent of the delay between irradiation and OSL readout...

  19. Saline volume expansion and cardiovascular physiology: novel observations, old explanations, and new questions.

    Science.gov (United States)

    Robotham, James L

    2004-10-01

    In a clinical investigation, Kumar and coworkers reported the hemodynamic events that accompany plasma volume expansion over 3 hours in healthy adult volunteers, and found that increases in stroke volume (SV) may be related to increases in left ventricular (LV)/right ventricular (RV) end-diastolic volume, as they expected, but also to decreases in LV/RV end-systolic volume. The latter finding suggests increased contractility and/or decreased afterload, which do not fit with their perception that clinicians ascribe increases in SV to increases in end-diastolic volume based on Starling's work. Increased ejection fraction and decreased vascular resistances were also observed. The same authors recently reported novel data suggesting that reduced blood viscosity may account for the observed reduction in vascular resistances with saline volume expansion. However, the variances in preload and afterload, along with uncertainty in estimates of contractility, substantially limit their ability to define a primary mechanism to explain decreases in LV end-systolic volume. A focus on using ejection fraction to evaluate the integrated performance of the cardiovascular system is provided to broaden this analytic perspective. Sagawa and colleagues described an approach to estimate the relationship, under clinical conditions, between ventricular and arterial bed elastances (i.e. maximal ventricular systolic elastance [Emax] and maximal arterial systolic elastance [Ea]), reflecting ventricular-arterial coupling. I used the mean data provided in one of the reports from Kumar and coworkers to calculate that LV Emax decreased from 1.09 to 0.96 mmHg/ml with saline volume expansion, while Ea decreased from 1.1 to 0.97 mmHg/ml and the SV increased (i.e. the increase in mean SV was associated with a decrease in mean afterload while the mean contractility decreased). The results reported by Kumar and coworkers invite further studies in normal and critically ill patients during acute saline

  20. Fetal cardiovascular physiology.

    Science.gov (United States)

    Rychik, J

    2004-01-01

    The cardiovascular system of the fetus is physiologically different than the adult, mature system. Unique characteristics of the myocardium and specific channels of blood flow differentitate the physiology of the fetus from the newborn. Conditions of increased preload and afterload in the fetus, such as sacrococcygeal teratoma and twin-twin transfusion syndrome, result in unique and complex pathophysiological states. Echocardiography has improved our understanding of human fetal cadiovasvular physiology in the normal and diseased states, and has expanded our capability to more effectively treat these disease processes.

  1. New perspectives of studying gastrointestinal muscle function

    Institute of Scientific and Technical Information of China (English)

    Hans Gregersen; Donghua Liao

    2006-01-01

    The motor function of the gastrointestinal tract has primarily been studied using manometry and radiography,though more indirect tests have also been applied. Manometry and radiography do not provide detailed information about the muscle properties as can be assessed from studies of muscle properties in muscle strips in vitro. In recent years a technique based on impedance planimetric mEasurement of pressure-cross-sectional area relations in a distending bag has proven to provide more detailed information about the muscle function in vivo. This review shows examples of new muscle function analysis such as length-tension diagrams, forcevelocity curves and preload-afterload diagrams.

  2. Cardiovascular issues in respiratory care.

    Science.gov (United States)

    Pinsky, Michael R

    2005-11-01

    The hemodynamic effects of ventilation are complex but can be grouped under four clinically relevant concepts. First, spontaneous ventilation is exercise, and critically ill patients may not withstand the increased work of breathing. Initiation of mechanical ventilatory support will improve oxygen delivery to the remainder of the body by decreasing oxygen consumption. To the extent that mixed venous oxygen also increases, Pao(2) will increase without any improvement in gas exchange. Similarly, weaning from mechanical ventilatory support is a cardiovascular stress test. Patients who fail to wean also manifest cardiovascular insufficiency during the failed weaning attempts. Improving cardiovascular reserve or supplementing support with inotropic therapy may allow patients to wean from mechanical ventilation. Second, changes in lung volume alter autonomic tone and pulmonary vascular resistance (PVR), and at high lung volumes compress the heart in the cardiac fossa. Hyperinflation increases PVR and pulmonary artery pressure, impeding right ventricular ejection. Decreases in lung volume induce alveolar collapse and hypoxia, stimulating an increased pulmonary vasomotor tone by the process of hypoxic pulmonary vasoconstriction. Recruitment maneuvers, positive end-expiratory pressure, and continuous positive airway pressure may reverse hypoxic pulmonary vasoconstriction and reduce pulmonary artery pressure. Third, spontaneous inspiration and spontaneous inspiratory efforts decrease intrathoracic pressure (ITP). Since diaphragmatic descent increases intra-abdominal pressure, these combined effects cause right atrial pressure inside the thorax to decrease but venous pressure in the abdomen to increase, markedly increasing the pressure gradient for systemic venous return. Furthermore, the greater the decrease in ITP, the greater the increase in left ventricular (LV) afterload for a constant arterial pressure. Mechanical ventilation, by abolishing the negative swings in ITP

  3. Centrifugal pump inlet pressure site affects measurement.

    Science.gov (United States)

    Augustin, Simon; Horton, Alison; Butt, Warwick; Bennett, Martin; Horton, Stephen

    2010-09-01

    During extracorporeal life support (ECLS), blood is exposed to a myriad of unphysiological factors that can affect outcome. One aspect of this is the sub-atmospheric pressure generated by the ECLS pump and imparted to blood elements along the pump inlet line. This pressure can be measured on the inlet line close to the pump head by adding a connector, or at the venous cannula connection site. We compared the two measurement sites located at both points; between the venous cannula-inlet tubing and inlet tubing-pump, with a range of cannulae and flows. We also investigated the effects on inlet pressure from pump afterload and increasing inlet tubing length.

  4. Stem signal suppression in fiber-coupled Al2O3:C dosimetry for 192Ir brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir; Andersen, Claus Erik; Edmund, J.M.;

    2011-01-01

    The stem signal, composed of fluorescence and Čerenkov light, becomes a significant source of uncertainty in fiber-coupled afterloaded brachytherapy dosimetry when the source dwells near the fiber cable but far from the detector. A stem suppression technique originally developed for scintillators...... was adapted for on-line in-vivo dosimetry using fiber-coupled carbon doped aluminum oxide (Al2O3:C). The technique involved a two-channel optical filtration of the radioluminescence (RL) emitted from a pre-irradiated Al2O3:C crystal with enhanced sensitivity. The system responded linearly in the absorbed dose...

  5. Effects of a New Glutamic Acid Derivative on Myocardial Contractility of Stressed Animals under Conditions of Nitric Oxide Synthesis Blockade.

    Science.gov (United States)

    Tyurenkov, I N; Perfilova, V N; Sadikova, N V; Berestovitskaya, V M; Vasil'eva, O S

    2015-07-01

    Glufimet (glutamic acid derivative) in a dose of 28.7 mg/kg limited the reduction of the cardiac functional reserve in animals subjected to 24-h stress under conditions of nonselective NO synthase blockade with L-NAME (10 mg/kg). Adrenoreactivity and increased afterload tests showed that the increment of myocardial contraction/relaxation rates, left-ventricular pressure, and HR were significantly higher in glufimet-treated stressed animals with NO synthesis blockade than in animals which received no glufimet. The efficiency of glufimet was higher than that of phenibut (the reference drug). PMID:26205724

  6. Matching models of left ventricle and systemic artery

    Institute of Scientific and Technical Information of China (English)

    柳兆荣; 吴驰

    1997-01-01

    To reveal how the matching models of the left ventricle and its afterload affect the pressure and flow in the aortic root, the differences between the measured pressure and flow waveforms and those determined by three kinds of matching model were compared. The results showed that, compared with the results by both matching models 1 and 2, the pressure and flow waveforms determined by matching model 3 established in this work were in the closest agreement with the corresponding experimental waveforms, therefore indicating that matching model 3 was a matching model that closely and rationally characterized the match between the left ventricle and the systemic artery.

  7. Emergency mitral valve replacement for acute severe mitral regurgitation following balloon mitral valvotomy: Pathophysiology of hemodynamic collapse and peri-operative management issues

    Directory of Open Access Journals (Sweden)

    Praveen Reddy Bayya

    2014-01-01

    Full Text Available Severe mitral regurgitation (MR following balloon mitral valvotomy (BMV needing emergent mitral valve replacement is a rare complication. The unrelieved mitral stenosis is compounded by severe MR leading to acute rise in pulmonary hypertension and right ventricular afterload, decreased coronary perfusion, ischemia and right ventricular failure. Associated septal shift and falling left ventricular preload leads to a vicious cycle of myocardial ischemia and hemodynamic collapse and needs to be addressed emergently before the onset of end organ damage. In this report, we describe the pathophysiology of hemodynamic collapse and peri-operative management issues in a case of mitral valve replacement for acute severe MR following BMV.

  8. I. Central Europe Symposium of Radiographers. Abstracts

    International Nuclear Information System (INIS)

    The publication contains abstracts of 20 contributions, out of which 2 have been inputted in INIS. One describes computed tomography methods employed by the Faculty Hospital in Hradec Kralove for liver angiography by using a contrast medium and for locating small hypervascular pancreatic islet-cell tumors. The other contribution informs about the use of linear accelerators and an afterloading system by the Faculty Hospital in Ceske Budejovice for radiotherapy of tumors of mammary glands, lymphatic nodes, the cervix, and of metastases. (M.D.)

  9. Sarns centrifugal pump for repair of thoracic aortic injury: case reports.

    Science.gov (United States)

    Walls, J T; Curtis, J J; Boley, T

    1989-09-01

    A new centrifugal pump (Sarns), originally designed for ventricular assist, was successfully used in two patients during repair of traumatic pseudoaneurysm of the descending thoracic aorta. The distal thoracic aorta was perfused without heparinization to avoid spinal cord and visceral ischemia, reduce afterload on the heart, and avoid clamp injury to the aorta. Distal mean aortic pressure was maintained above 50 mm Hg with a mean pump flow of 1.75 liter/minute. Proposed structural advantages of the Sarns centrifugal pump for perfusion of the distal thoracic aorta without heparin are resistance to thrombus formation, air embolus, and hemolysis.

  10. Khan's the physics of radiation therapy

    CERN Document Server

    Khan, Faiz M

    2014-01-01

    Expand your understanding of the physics and practical clinical applications of advanced radiation therapy technologies with Khan's The Physics of Radiation Therapy, 5th edition, the book that set the standard in the field. This classic full-color text helps the entire radiation therapy team-radiation oncologists, medical physicists, dosimetrists, and radiation therapists-develop a thorough understanding of 3D conformal radiotherapy (3D-CRT), stereotactic radiosurgery (SRS), high dose-rate remote afterloaders (HDR), intensity modulated radiation therapy (IMRT), image-guided radiation therapy (

  11. Acute right heart syndrome: Rescue treatment with inhaled nitric oxide

    Directory of Open Access Journals (Sweden)

    Ashish Garg

    2014-01-01

    Full Text Available Acute right heart syndrome is a common occurrence in intensive care units and is associated with a poor prognosis. There is lack of understanding of the involved pathophysiology, standard diagnostic protocols and treatment guidelines. Management goals include ensuring adequate right ventricle (RV filling, maximizing RV contraction and reducing RV afterload. We describe a 39-year-old female with acute decompensated right heart failure secondary to multiple causes. She was managed with inhaled nitric oxide. Her condition improved, which was evident by a decrease in her pulmonary artery systolic pressure on serial echocardiography, decreased requirement of vasopressors and successful weaning from the ventilator.

  12. Simulation of the Frank-Starling Law of the Heart

    Directory of Open Access Journals (Sweden)

    Samo Ribarič

    2012-01-01

    Full Text Available We developed a lumped parameter, computer-based model of an equivalent electronic circuit for a one-atrium one-ventricle (frog heart attached to a vascular circuit, to simulate a basic concept of cardiovascular physiology, the Frank-Starling Law of the Heart. A series of simulations was performed, to observe changes in cardiovascular variables (e.g., arterial pressure, ventricular volume, and valve flows if either preload or afterload was increased. The simulated data agreed qualitatively, and quantitatively when experimental data are available, with data obtained on amphibian or on mammalian myocardium. In addition, the data obtained in these simulations improve our understanding of the mechanism(s whereby the heart muscle adapts itself to increased distension (increased preload or to impeded systolic contraction (increased afterload. The analysis of the measured valve flows suggests that the ventricle is a highly input sensitive pump because the input pressure determines the diastolic distension and, consequently, the force of ventricular systolic contraction. On the other hand, the ventricle is a relatively output insensitive pump. Therefore, not only atrium contraction, but also predominantly the preceding ventricular systolic contraction is the main mechanism of the subsequent diastolic ventricular filling. We conclude that the presented model enables the study of basic concepts of cardiovascular physiology.

  13. Characterization of HDR Ir-192 source for 3D planning system

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P.; Yoriyaz, Helio; Antunes, Paula C.G.; Siqueira, Paulo T.D., E-mail: gabriel.fonseca@usp.b, E-mail: hyoriyaz@ipen.b, E-mail: ptsiquei@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rubo, Rodrigo [Universidade de Sao Paulo (HC/FMUSP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia; Minamisawa, Renato A., E-mail: renato.minamisawa@psi.c [Paul Scherrer Institut (PSI), Villigen (Switzerland); Ferreira, Louise A. [Universidade Estadual de Maringa (UEM), PR (Brazil). Fac. de Medicina

    2011-07-01

    Brachytherapy treatment involves surgical or cavitary insertion of radioactive sources for diseases treatments, such as: lung, gynecologic or prostate cancer. This technique has great ability to administer high doses to the tumor, with adjacent normal tissue preservation equal or better than external beam radiation therapy. Several innovations have been incorporated in this treatment technique, such as, 3D treatment planning system and computer guided sources. In detriment to scientific advances there are no protocols that relate dose with tumor volume, organs or A point, established by ICRU38 and used to prescribe dose in treatment planning system. Several international studies, like as EMBRACE, the multicentre international study, has been trying to correlate the dose volume using 3D planning systems and medical images, as those obtained by CT or MRI, to establish treatment protocols. With the objective of analyzing the 3D dose distribution, a micro Selectron-HDR remote afterloading device for high dose-rate (HDR) was characterized in the present work. Through the data provided by the manufacturer the source was simulated, using the MCNP5 code to calculate American Association of Physicists in Medicine Task Group No. 43 report (AAPM TG43) specified parameters. The simulations have shown great agreement when compared to the ONCENTRA planning system results and those provided by literature. The micro Selectron-HDR remote afterloading device will be utilized to simulate 3D dose distribution through CT images processed by an auxiliary software which process DICOM images. (author)

  14. Our experience with implantation of VentrAssist left ventricular assist device

    Directory of Open Access Journals (Sweden)

    Hiriyur Shivalingappa Jayanthkumar

    2013-01-01

    Full Text Available Perioperative anaesthetic management of the VentrAssist TM left ventricular assist device (LVAD is a challenge for anaesthesiologists because patients presenting for this operation have long-standing cardiac failure and often have associated hepatic and renal impairment, which may significantly alter the pharmacokinetics of administered drugs and render the patients coagulopathic. The VentrAssist is implanted by midline sternotomy. A brief period of cardiopulmonary bypass (CPB for apical cannulation of left ventricle is needed. The centrifugal pump, which produces non-pulsatile, continuous flow, is positioned in the left sub-diaphragmatic pocket. This LVAD is preload dependent and afterload sensitive. Transoesophageal echocardiography is an essential tool to rule out contraindications and to ensure proper inflow cannula position, and following the implantation of LVAD, to ensure right ventricular (RV function. The anaesthesiologist should be prepared to manage cardiac decompensation and acute desaturation before initiation of CPB, as well as RV failure and severe coagulopathic bleeding after CPB. Three patients had undergone implantation of VentrAssist in our hospital. This pump provides flow of 5 l/min depending on preload, afterload and pump speed. All the patients were discharged after an average of 30 days. There was no perioperative mortality.

  15. Our experience with implantation of VentrAssist left ventricular assist device

    Science.gov (United States)

    Jayanthkumar, Hiriyur Shivalingappa; Murugesan, Chinnamuthu; Rajkumar, John; Harish, Bandlapally Ramanjaneya Gupta; Muralidhar, Kanchi

    2013-01-01

    Perioperative anaesthetic management of the VentrAssist™ left ventricular assist device (LVAD) is a challenge for anaesthesiologists because patients presenting for this operation have long-standing cardiac failure and often have associated hepatic and renal impairment, which may significantly alter the pharmacokinetics of administered drugs and render the patients coagulopathic. The VentrAssist is implanted by midline sternotomy. A brief period of cardiopulmonary bypass (CPB) for apical cannulation of left ventricle is needed. The centrifugal pump, which produces non-pulsatile, continuous flow, is positioned in the left sub-diaphragmatic pocket. This LVAD is preload dependent and afterload sensitive. Transoesophageal echocardiography is an essential tool to rule out contraindications and to ensure proper inflow cannula position, and following the implantation of LVAD, to ensure right ventricular (RV) function. The anaesthesiologist should be prepared to manage cardiac decompensation and acute desaturation before initiation of CPB, as well as RV failure and severe coagulopathic bleeding after CPB. Three patients had undergone implantation of VentrAssist in our hospital. This pump provides flow of 5 l/min depending on preload, afterload and pump speed. All the patients were discharged after an average of 30 days. There was no perioperative mortality. PMID:23716768

  16. Fontan's circulation with dextrocardia, recent pulmonary embolism, and inferior vena cava filter: Anesthetic challenges for urgent hysterectomy.

    Science.gov (United States)

    Singh, Preet Mohinder; Borle, Anuradha; Ramachandran, Rashmi; Trikha, Anjan; Goudra, Basavana Gouda

    2016-01-01

    Fontan's circulation is a unique challenge for the anesthesiologist. Venous pressure is the only source of blood flow for the pulmonary circulation. Patients with such circulation are extremely sensitive to progression of cyanosis (decreased pulmonary blood flow) or circulatory failure. Any major venous compression can compromise the pulmonary blood flow worsening cyanosis; simultaneously, an increased afterload can precipitate circulatory failure. We present a rare patient of surgically corrected Ivemark syndrome with Fontan's physiology with dextrocardia who developed a large uterine fibroid compressing inferior vena cava (IVC). As a result of compression, not only the pulmonary circulation was compromised but she also developed stasis-induced venous thrombosis in the lower limbs that lead to pulmonary embolism (PE) (increased afterload). In addition to oral anticoagulation an IVC filter was inserted to prevent ongoing recurrent PE. Further, to prevent both circulatory compromise and deep venous thrombosis an urgent myomectomy/hysterectomy was planned. In the present case, we discuss the issues involved in the anesthetic management of such patients and highlight the lacunae in the present guidelines for managing perioperative anticoagulation these situations.

  17. Fontan′s circulation with dextrocardia, recent pulmonary embolism, and inferior vena cava filter: Anesthetic challenges for urgent hysterectomy

    Directory of Open Access Journals (Sweden)

    Preet Mohinder Singh

    2016-01-01

    Full Text Available Fontan′s circulation is a unique challenge for the anesthesiologist. Venous pressure is the only source of blood flow for the pulmonary circulation. Patients with such circulation are extremely sensitive to progression of cyanosis (decreased pulmonary blood flow or circulatory failure. Any major venous compression can compromise the pulmonary blood flow worsening cyanosis; simultaneously, an increased afterload can precipitate circulatory failure. We present a rare patient of surgically corrected Ivemark syndrome with Fontan′s physiology with dextrocardia who developed a large uterine fibroid compressing inferior vena cava (IVC. As a result of compression, not only the pulmonary circulation was compromised but she also developed stasis-induced venous thrombosis in the lower limbs that lead to pulmonary embolism (PE (increased afterload. In addition to oral anticoagulation an IVC filter was inserted to prevent ongoing recurrent PE. Further, to prevent both circulatory compromise and deep venous thrombosis an urgent myomectomy/hysterectomy was planned. In the present case, we discuss the issues involved in the anesthetic management of such patients and highlight the lacunae in the present guidelines for managing perioperative anticoagulation these situations.

  18. Selective management of cardiovascular dysfunction in posttraumatic SIRS and sepsis.

    Science.gov (United States)

    Martin, R Shayn; Kincaid, Edward H; Russell, Hyde M; Meredith, J Wayne; Chang, Michael C

    2005-03-01

    Cardiovascular dysfunction associated with the systemic inflammatory response syndrome (SIRS) is caused by a combination of decreased myocardial contractility and low vascular resistance. The contribution of each of these components can be determined at the bedside, and directed therapy can be appropriately initiated. Over an 8-month period of time, 23 consecutive patients who experienced posttraumatic SIRS while still being monitored with a volumetric pulmonary artery catheter (PAC) were prospectively evaluated. Ventricular pressure-volume diagrams were constructed to quantify myocardial contractility and afterload. In a resuscitation protocol, dobutamine was administered to patients with an isolated decrease in contractility, and dopamine or epinephrine was instituted for the combination of reduced contractility and afterload. Variables describing cardiovascular function were measured at the time of resolution of initial shock resuscitation (BASE), at the onset of SIRS (ONSET), and after administration of inotropic or vasoactive agents (TREAT). ONSET was associated with a significant decrease in left ventricular power (LVP) (362 +/- 96 to 235 +/- 55 mmHg.L/min/m(2), P index (SWI) (4670 +/- 1213 to 3060 +/- 848 mmHg.mL/m, P SWI significantly increased (235 +/- 55 to 328 +/- 77 mmHg.L/min/m(2), P < 0.00001, and 3060 +/- 848 to 4554 +/- 1423 mmHg.mL/m(2), P < 0.00001, respectively) on the initiation of directed therapy. Specific cardiovascular abnormalities can be identified at the bedside, and this information can guide pharmacologic management. Directed therapy improves cardiovascular function. PMID:15718916

  19. Monte Carlo dosimetric characterization of the Cs-137 selectron/LDR source: Evaluation of applicator attenuation and superposition approximation effects

    International Nuclear Information System (INIS)

    The purpose of this study is to calculate the dose rate distribution for the Amersham Cs-137 pellet source used in brachytherapy with the Selectron low-dose-rate remote afterloading system in gynaecological applications using the Monte Carlo code GEANT4. The absolute dose rate distribution for the pellet source was obtained and presented as a one-dimensional absolute dose rate table as well as in the Task Group 43 dose-calculation formalism. In this study, excellent agreement was found between the point source theoretical model using fitted polynomial values and Monte Carlo calculations of the dose rate distribution for the pellet source. A comparison study was also made between the dose rate distribution obtained from a complete Monte Carlo simulation (Cs-137 pellet sources+remote afterloading system plastic guide tube+gynaecological applicator) and that calculated by applying the superposition principle to Monte Carlo data of the individual pellet sources. The data were obtained for a portion of uterine tandem of typical train source configurations. Significant differences with a strong dependence on polar angle have been found that must be kept in mind for clinical dosimetry

  20. Right ventricular nitric oxide signaling in an ovine model of congenital heart disease: a preserved fetal phenotype.

    Science.gov (United States)

    Kameny, Rebecca Johnson; He, Youping; Morris, Catherine; Sun, Christine; Johengen, Michael; Gong, Wenhui; Raff, Gary W; Datar, Sanjeev A; Oishi, Peter E; Fineman, Jeffrey R

    2015-07-01

    We recently reported superior right ventricle (RV) performance in response to acute afterload challenge in lambs with a model of congenital heart disease with chronic left-to-right cardiac shunts. Compared with control animals, shunt lambs demonstrated increased contractility because of an enhanced Anrep effect (the slow increase in contractility following myocyte stretch). This advantageous physiological response may reflect preservation of a fetal phenotype, since the RV of shunt lambs remains exposed to increased pressure postnatally. Nitric oxide (NO) production by NO synthase (NOS) is activated by myocyte stretch and is a necessary intermediary of the Anrep response. The purpose of this study was to test the hypothesis that NO signaling is increased in the RV of fetal lambs compared with controls and shunt lambs have persistence of this fetal pattern. An 8-mm graft was placed between the pulmonary artery and aorta in fetal lambs (shunt). NOS isoform expression, activity, and association with activating cofactors were determined in fetal tissue obtained during late-gestation and in 4-wk-old juvenile shunt and control lambs. We demonstrated increased RNA and protein expression of NOS isoforms and increased total NOS activity in the RV of both shunt and fetal lambs compared with control. We also found increased NOS activation and association with cofactors in shunt and fetal RV compared with control. These data demonstrate preserved fetal NOS phenotype and NO signaling in shunt RV, which may partially explain the mechanism underlying the adaptive response to increased afterload seen in the RV of shunt lambs.

  1. Left ventricular mass in chronic kidney disease and ESRD.

    Science.gov (United States)

    Glassock, Richard J; Pecoits-Filho, Roberto; Barberato, Silvio H

    2009-12-01

    Chronic kidney disease (CKD) and ESRD, treated with conventional hemo- or peritoneal dialysis are both associated with a high prevalence of an increase in left ventricular mass (left ventricular hypertrophy [LVH]), intermyocardial cell fibrosis, and capillary loss. Cardiac magnetic resonance imaging is the best way to detect and quantify these abnormalities, but M-Mode and 2-D echocardiography can also be used if one recognizes their pitfalls. The mechanisms underlying these abnormalities in CKD and ESRD are diverse but involve afterload (arterial pressure and compliance), preload (intravascular volume and anemia), and a wide variety of afterload/preload independent factors. The hemodynamic, metabolic, cellular, and molecular mediators of myocardial hypertrophy, fibrosis, apoptosis, and capillary degeneration are increasingly well understood. These abnormalities predispose to sudden cardiac death, most likely by promotion of electrical instability and re-entry arrhythmias and congestive heart failure. Current treatment modalities for CKD and ESRD, including thrice weekly conventional hemodialysis and peritoneal dialysis and metabolic and anemia management regimens, do not adequately prevent or correct these abnormalities. A new paradigm of therapy for CKD and ESRD that places prevention and reversal of LVH and cardiac fibrosis as a high priority is needed. This will require novel approaches to management and controlled interventional trials to provide evidence to fuel the transition from old to new treatment strategies. In the meantime, key management principles designed to ameliorate LVH and its complications should become a routine part of the care of the patients with CKD and ESRD. PMID:19996010

  2. Prognostic utility of blood pressure-adjusted global and basal systolic longitudinal strain

    Directory of Open Access Journals (Sweden)

    Isaac B Rhea

    2016-05-01

    Full Text Available Assessment of global longitudinal systolic strain (GLS and longitudinal systolic strain of the basal segments (BLS has shown prognostic value in cardiac disorders. However, strain is reduced with increased afterload. We assessed the prognostic value of GLS and BLS adjusted for afterload. GLS and BLS were determined in 272 subjects with normal ejection fraction and no known coronary disease, or significant valve disease. Systolic blood pressure (SP and diastolic blood pressure (DP obtained at the time of echocardiography were used to adjust GLS and BLS as follows: strain × SP (mmHg/120 mmHg and strain × DP (mmHg/80 mmHg. Patients were followed for cardiac events and mortality. The mean age was 53 ± 15 years and 53% had hypertension. There were 19 cardiac events and 70 deaths over a mean follow-up of 26 ± 14 months. Cox analysis showed that left ventricular mass index (P = 0.001, BLS (P < 0.001, and DP-adjusted BLS (P < 0.001 were independent predictors of cardiac events. DP-adjusted BLS added incremental value (P < 0.001 to the other two predictors and had an area under the curve of 0.838 for events. DP (P = 0.001, age (P = 0.001, ACE inhibitor use (P = 0.017, and SP-adjusted BLS (P = 0.012 were independent predictors of mortality. SP-adjusted BLS added incremental value (P = 0.014 to the other independent predictors. In conclusion, DP-adjusted BLS and SP-adjusted BLS were independent predictors of cardiac events and mortality, respectively. Blood pressure-adjusted strain added incremental prognostic value to other predictors of outcome. Introduction Assessment of global longitudinal systolic strain (GLS and basal longitudinal systolic strain (BLS have shown utility for prediction of prognosis in various cardiac disorders (1, 2, 3, 4. In some studies, longitudinal strain has been shown to be a more sensitive indicator of left ventricular (LV systolic dysfunction than traditional measures of function (5, 6. The detection of early

  3. Implementation of a High-Dose-Rate Brachytherapy Program for Carcinoma of the Cervix in Senegal: A Pragmatic Model for the Developing World

    International Nuclear Information System (INIS)

    West Africa has one of the highest incidence rates of carcinoma of the cervix in the world. The vast majority of women do not have access to screening or disease treatment, leading to presentation at advanced stages and to high mortality rates. Compounding this problem is the lack of radiation treatment facilities in Senegal and many other parts of the African continent. Senegal, a country of 13 million people, had a single 60Co teletherapy unit before our involvement and no brachytherapy capabilities. Radiating Hope, a nonprofit organization whose mission is to provide radiation therapy equipment to countries in the developing world, provided a high-dose-rate afterloading unit to the cancer center for curative cervical cancer treatment. Here we describe the implementation of high-dose-rate brachytherapy in Senegal requiring a nonstandard fractionation schedule and a novel treatment planning approach as a possible blueprint to providing this technology to other developing countries

  4. Biomedical neutron research at the Californium User Facility for neutron science

    International Nuclear Information System (INIS)

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact 252Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with 252Cf sources. Three projects at the CUF that demonstrate the versatility of 252Cf for biological and biomedical neutron-based research are described: future establishment of a 252Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded 252Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy

  5. Association of Right Ventricular Pressure and Volume Overload with Non-Ischemic Septal Fibrosis on Cardiac Magnetic Resonance.

    Directory of Open Access Journals (Sweden)

    Jiwon Kim

    Full Text Available Non-ischemic fibrosis (NIF on cardiac magnetic resonance (CMR has been linked to poor prognosis, but its association with adverse right ventricular (RV remodeling is unknown. This study examined a broad cohort of patients with RV dysfunction, so as to identify relationships between NIF and RV remodeling indices, including RV pressure load, volume and wall stress.The population comprised patients with RV dysfunction (EF 6-fold more common in the highest, vs. the lowest, common tertile of PASP and RV size (p<0.001.Among wall stress components, NIF was independently associated with RV chamber dilation and afterload, supporting the concept that NIF is linked to adverse RV chamber remodeling.

  6. Endocurietherapy of breast cancer III

    International Nuclear Information System (INIS)

    We recently introduced the implantation of Iridium192 as a method of local treatment of breast cancer in Austria. The afterloading technique is described. This modality should be used as a boost to the 'high-risk' areas following conservative breast surgery and combined with megavoltage external irradiation. Interstitial implantation may also be used as a primary form of treatment. A report on 35 patients is presented, 25 of whom underwent a curative schedule for T1-2, N0-1 tumors. 10 patients were treated individually. The aesthetic results are very pleasing. There were no severe complications and no early local recurrences. The interpretation of the results can be only in the form of trends because of the short follow-up time of 1 year. (Author)

  7. Long term effect of cervix carcinoma treated by HDR 192 Ir afterloding intracavitory radiotherapy combined with external irradiation.%高剂量率192Ir后装腔内加外照射治疗宫颈癌的远期疗效分析

    Institute of Scientific and Technical Information of China (English)

    王青; 侯晓玲; 赵淑红

    2001-01-01

    Objective To analyze retrosrectively long- term effect of cervix carcinona treated by HDR 192Ir afterloading intracavitory radiotherapy combined with external irradiation. Methods From Mar 1993 to Dec 1994, 128 cases of cervix cancer(age from 29 years to 80 years) were treated with combination of external irradiation and HDR 192Ir afterloading intracavitory radiotherapy. 47 cases were stage Ⅱ and 81 were stage Ⅲ. The dose of external radiotherapy was 40 Gy or 50 Gy and afterloading irradiation was given in 6 or 7 fractions of 8 Gy. Results The overall local tumor control was 94.5%, the 1,3,5 year survival rates were 91.61%, 81.89%and 67.36%. The 1,3,5 year survival rates of stage Ⅱ and stage Ⅲ cases were 95.28% and 89. 47%, 87.19% and 79.50%, 72.76% and 64.95% (P>0.05). The rate of severe complications was 7.03% (9/128). Conclusion HDR 192Ir afterloading intracavitory radiotherapy combined with external irradiation for cervix carcinoma is effective and less side effects.%目的分析高剂量率192Ir后装腔内加外照射治疗宫颈癌的远期疗效及并发症。方法对128例Ⅱ、Ⅲ期放疗后宫颈癌进行了回顾分析。其中Ⅱ期47例,Ⅲ期81例。全盆腔外照射Dr20Gy/10次,全盆中间挡铅4cmDr20Gy~30Gy/10次~15次;后装A点剂量48Gy~56Gy/6次~7次。结果 1、3、5年生存率分别为91.61%、81.8%和67.36%;Ⅱ、Ⅲ期1、3、5年生存率无统计学差异(P>0.05);远期严重并发症的发生率7.03%(9/128)。结论高剂量率192Ir后装腔内加外照射治疗宫颈癌疗效肯定,并发症少。盆腔局部复发仍是放疗失败的主要原因。

  8. Development of high-activity 252Cf sources for neutron brachytherapy

    International Nuclear Information System (INIS)

    The Gershenson Radiation Oncology Center of Wayne State University (WSU), Detroit, Michigan, is using 252Cf medical sources for neutron brachytherapy. These sources are based on a 20-year-old design containing ≤ 30 microg 252Cf in the form of a cermet wire of Cf2O3 in a palladium matrix. The Radiochemical Engineering Development Center (REDC) of Oak Ridge National Laboratory has been asked to develop tiny high-activity 252Cf neutron sources for use with remote afterloading equipment to reduce treatment times and dose to clinical personnel and to expedite treatment of brain and other tumors. To date, the REDC has demonstrated that 252Cf loadings can be greatly increased in cermet wires much smaller than before. Equipment designed for hot cell fabrication of these wires is being tested. A parallel program is under way to relicense the existing source design for fabrication at the REDC

  9. The Role of Obesity in the Development of Left Ventricular Hypertrophy Among Children and Adolescents.

    Science.gov (United States)

    Brady, Tammy M

    2016-01-01

    Both obesity and hypertension have increased substantially among children over the last several decades. At the same time, mounting evidence has pointed to the role of these and other cardiovascular disease risk factors on the development of end organ damage such as left ventricular hypertrophy in children. While traditionally thought to occur in response to an increased afterload as in systemic hypertension, evidence demonstrates that obesity is associated with left ventricular hypertrophy independent of blood pressure. Both hemodynamic and non-hemodynamic factors contribute to the pathogenesis of obesity-related left ventricular remodeling. However, more contemporary research suggests that adiposity and blood pressure have a greater effect on left ventricular geometry when present together than when present alone. Normalization of left ventricular mass in obese hypertensive individuals requires achievement of both normotension and weight loss. Additional strategies are needed to promote the cardiovascular health of children, with greater emphasis placed on obesity prevention.

  10. The thickened left ventricle: etiology, differential diagnosis and implications for cardiovascular radiology; Der dicke linke Ventrikel. Ursachen und Differenzialdiagnose der linksventrikulaeren Hypertrophie und Implikationen fuer die kardiovaskulaere Radiologie

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, P.; Barkhausen, J.; Hunold, P. [Universitaetsklinikum Schleswig-Holstein, Luebeck (Germany). Klinik fuer Radiologie und Nuklearmedizin; Radke, P.W. [Universitaetsklinikum Schleswig Holstein, Luebeck (Germany). Medizinische Klinik II

    2012-08-15

    Hypertrophy of the left ventricular myocardium is a common finding and can be reliably detected by echocardiography, CT and MRI. Common causes include diseases associated with increased cardiac afterload as well as primary and secondary cardiomyopathy. With the opportunity to determine functional parameters and myocardial mass precisely as well as to detect structural changes of the cardiac muscle simultaneously, cardiac MRI is the most precise imaging method for quantifying left ventricular hypertrophy as well as determining the cause and the exact characterization of the myocardial changes. It is mandatory, however, to create a flexible, individually adapted examination protocol. This review presents useful diagnostic algorithms in relation to different underlying pathologies in patients with left ventricular hypertrophy. (orig.)

  11. Newer methods of cardiac output monitoring

    Institute of Scientific and Technical Information of China (English)

    Yatin; Mehta; Dheeraj; Arora

    2014-01-01

    Cardiac output(CO) is the volume of blood ejected by each ventricle per minute and is the product of stroke volume and heart rate. CO can thus be manipulated by alteration in heart rate or rhythm, preload, contractility and afterload. Moreover it gives important information about tissue perfusion and oxygen delivery. CO can be measured by various methods and thermodilution method using pulmonary artery catheter(PAC) is till date considered as gold standard method. Complications associated with PAC led to development of newer methods which are minimally or non-invasive. Newer methods fulfil other properties like continuous and reproducible reading, cost effective, reliable during various physiological states and have fast response time. These methods are validated against the gold standard with good level agreement. In this review we have discussed various newer methods of CO monitoring and their effectiveness in clinical use.

  12. 中药保留灌肠预防宫颈癌患者放射性直肠损伤的效果%Effects of Retention Enema with Chinese Herbs on Prevention of Radioactive Rectum Damage in Cervical Cancer Patients

    Institute of Scientific and Technical Information of China (English)

    许燕; 张兰凤; 鞠小梅; 陈曾燕; 张曦霞; 叶赟

    2012-01-01

    Objective To verify the effect of retention enema with Chinese herbs on prevention of cervical cancer-related radioactive rectum damage. Methods From November 2009 to June 2011, 100 cervical cancer patients treated with radiation therapy were randomized into experimental group (n= 50) and control group(n=50). All the patients were treated with radio-therapy and the conventional care. Following after-loading therapy, patients in the experimental group were also treated with self-made retention enema of Chinese herbs(80~100 ml,once per day for continuous 3 days)until all the after-loading therapy finished. We compared the rectum reactions of after-loading therapy for five times three days later, 3 and 6 months after radiotherapy. Results Following after-loading therapy for five times three days later, the incidence rate of grade 1 and grade 2 rectum reactions in the experimental group was significantly lower than that in the control group(P<0. 05) ;besides,the incidence rate and the extent of rectal damage in the experimental group were also significantly lower than those in the control group 3 months and 6 months after treatment (P<0. 05). Conclusion The application of retention enema with Chinese herbs can reduce the radioactive rectum reactions in cervical cancer patients during radiotherapy.%目的 探讨中药保留灌肠预防宫颈癌患者放射治疗所致放射性直肠损伤的效果.方法 按随机数字表法将2009年11月至2011年6月在南通市肿瘤医院行放射治疗的100例宫颈癌患者分为对照组及中药预防组各50 例,对照组采用放射治疗常规护理,中药预防组除常规护理外,在后装放射治疗后用自制中药80~100 ml行保留灌肠,1次/d,连续3 d,直至后装治疗结束.观察后装放射治疗5次3 d内、治疗结束后3个月、6个月两组患者发生放射性直肠损伤的情况.结果 中药预防组后装放射治疗5次3 d内1、2级直肠损伤发生率均低于对照组(均P<0.05

  13. Occupational exposure in medicine - a review of radiation doses to hospital staff in north-west England

    International Nuclear Information System (INIS)

    monitoring results relating principally to exposure during 1981 have been collated and examined. The analysis indicates that the doses received by staff are for the most part very low and provide little reason for concern. The only area of work in which worthwhile and cost-effective dose reductions could probably be achieved is that involving the use of pre-loaded applicators in gynaecological intra-cavitary therapy. Some relatively high staff exposures result from the use of this technique, and very significant reductions in these doses are confidently expected from a programme which has now commenced for the increasing use of remotely-controlled after-loading equipment housed in shielded treatment rooms. (author)

  14. Studies on occupational exposure to external radiation at Fukuoka University Hospital

    International Nuclear Information System (INIS)

    This is a report of the yearly changes of exposure received by workers in radiological occupations at Fukuoka University Hospital from August 1973 to December 1980. The total number of the workers during this period involving diagnostic radiology, radiotherapy and the other related fields included 153 physicians, 27 technicians, 29 nurses and 16 assistants. Out of 225 workers, only two angiographers and two involved in intracavitary radiation therapy received more than 500 mrem of the annual exposure dose. The highest dose was 610 mrem. The exposure doses have gradually decreased each year. The exposure of the workers has remarkably decreased to almost negligible since a remote afterloading system was installed for intracavitary radiation therapy. In no worker was any somatic effect of radiation detected in the periodical physical examinations, even in the number of lymphocytes in the peripheral blood. (author)

  15. Biomedical neutron research at the Californium User Facility for neutron science

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.C. [Oak Ridge National Lab., TN (United States); Byrne, T.E. [Roane State Community College, Harriman, TN (United States); Miller, L.F. [Univ. of Tennessee, Knoxville, TN (United States)

    1997-04-01

    The Californium User Facility for Neutron Science has been established at Oak Ridge National Laboratory (ORNL). The Californium User Facility (CUF) is a part of the larger Californium Facility, which fabricates and stores compact {sup 252}Cf neutron sources for worldwide distribution. The CUF can provide a cost-effective option for research with {sup 252}Cf sources. Three projects at the CUF that demonstrate the versatility of {sup 252}Cf for biological and biomedical neutron-based research are described: future establishment of a {sup 252}Cf-based neutron activation analysis system, ongoing work to produce miniature high-intensity, remotely afterloaded {sup 252}Cf sources for tumor therapy, and a recent experiment that irradiated living human lung cancer cells impregnated with experimental boron compounds to test their effectiveness for boron neutron capture therapy.

  16. A simple device to protect against osteoradionecrosis induced by interstitial irradiation

    International Nuclear Information System (INIS)

    The incidence of osteoradionecrosis has declined since the introduction of preventive oral hygiene programs and meticulous dental evaluations before and after irradiation. Nevertheless, radiation dose per se still remains an important factor in osteoradionecrosis. Interstitial radiation has received much attention in the past decade since the use of flexible afterloading systems. It has become common practice in large oncology centers to implant radiation carriers in bulky tumor in the oral cavity and/or oropharynx. For interstitial radiation, with or without external radiation, minimal tumor doses are often cited to be more than 70 Gy. Unfortunately, if the mandible receives more than 70 Gy, it is at risk for the development of osteoradionecrosis. Therefore a simple protective lead device has been designed for routine use in brachytherapy in oral cavity tumors to reduce the dose to the mandible. This device will diminish the potential risk of osteoradionecrosis development

  17. Pathophysiological and clinical aspects of carbonic dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

    Larsen, Jens Fromholt

    by CO 2 -PP ? endocrine and metabolic response may be activated and the inflammatory response blunted by CO 2 -PP   ? mean arterial pressure and heart rate is increased during CO 2 -PP ? preload and afterload is increased, heart performance decreased, but cardiac output not affected during CO 2 -PP...... pneumoperitoneum (CO 2 -PP) and positional changes of the patients are the general methods of exposing the intraperitoneal organs. Carbonic dioxide (CO 2 ) is the preferred gas, because it is inexpensive, highly soluble, and chemically stable. In addition, it suppresses combustion and is a normal product of human...... invasive methods. Based on a randomized design comparing conventional with gasless laparoscopy the effects of CO 2 - PP are investigated in regard to: ? outcome, pain, convalescence, ? coagulation and fibrinolysis ? surgical stress response ? perioperative haemodynamics and heart performance...

  18. Mechanical stimulation in the engineering of heart muscle.

    Science.gov (United States)

    Liaw, Norman Yu; Zimmermann, Wolfram-Hubertus

    2016-01-15

    Recreating the beating heart in the laboratory continues to be a formidable bioengineering challenge. The fundamental feature of the heart is its pumping action, requiring considerable mechanical forces to compress a blood filled chamber with a defined in- and outlet. Ventricular output crucially depends on venous loading of the ventricles (preload) and on the force generated by the preloaded ventricles to overcome arterial blood pressure (afterload). The rate of contraction is controlled by the spontaneously active sinus node and transmission of its electrical impulses into the ventricles. The underlying principles for these physiological processes are described by the Frank-Starling mechanism and Bowditch phenomenon. It is essential to consider these principles in the design and evaluation of tissue engineered myocardium. This review focuses on current strategies to evoke mechanical loading in hydrogel-based heart muscle engineering.

  19. New approach for new target: adaptive servo-ventilation on Cheyne-Stokes respiration in congestive heart failure

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) occurs when periods of hyperventilation with waxing/waning tidal volume alternated with periods of central hypopnea/apnea. It is present in approximately 40 percent of patients with severe congestive heart failure (CHF). CSR-CSA may contribute to the progression of heart failure by causing repetitive arterial oxygen desaturation, sleep fragmentation, increased left ventricular afterload, activation of sympathetic nervous system, and oscillations in heart rate and blood pressure. There are evidences indicating that CSR-CSA is associated with a remarkable increase in mortality and is also an independent risk factor for cardiac transplantation; furthermore, treatment of CSR-CSA in combination with optimal medical therapy may influence the course of chronic heart failure, improve quality of life and the survival of patients.1 The paper by Zhang et al2 highlights the importance of recognizing this pathological breathing pattern as a potential therapeutic target.

  20. Case Report: Postpartum Cough and Dyspnea.

    Science.gov (United States)

    Czerwinski, Eileen M

    2016-01-01

    Peripartum/postpartum cardiomyopathy (PPCM) is a rare condition associated with pregnancy in which there is left ventricular (LV) dysfunction resulting in symptoms of heart failure (). This occurs in previously healthy women and is seen in the last month of pregnancy or during the first 5 months postpartum (). Incidence ranges from 1 in 1,300 to 1 in 15,000 pregnancies in the United States (). A case study is presented of a patient with severe impairment of LV function seen in the emergency department (ED). The ED is a common location for initial presentation; therefore, the ED provider should be cognizant of key features of PPCM. The differential diagnosis and medical management of PPCM are discussed. Emergency department management should focus on 3 key elements: an increase in inotropy and a reduction in preload and afterload. Differences between postpartum and peripartum states are outlined. PMID:27482991

  1. ABNORMAL LEFT VENTRICULAR SYSTOLIC AND DIASTOLIC FUNCTIONAL RESPONSE TO ISOMETRIC EXERCISE IN IDIOPATHIC DILATED CARDIOMY-OPATHY:BENEFICIAL EFFECT OF CAPTOPRIE

    Institute of Scientific and Technical Information of China (English)

    沈卫峰; 张宪; 胡厚达; 龚兰生

    1995-01-01

    In 19 patients with idiopathic dilated cardiomyopathy and symptoms of congetive haert failure,left ventricular (LV) systolic performance and diastolic velocity profiles were assessed by two-dimensional e-chocardiography and pulsed wave Doppler at rest and during handgrip exercise before and ninety minutes after administration of captopril (mean dose 25±12mg);range 12.5-50mg).Although heart rate and blood pressure increased similarly during handgrip exercise before and after captopril treatment,both were lower with handgrip exercise during captopril treatment.The results from this study indicated that acute angiotensin converting enzyme inhibition with captopril reduces preload and afterload and ameliorates hand-grip exercise-induced LV systolic and diastolic filling dysfunction in patients with congestive bheart failure secondary to idiopathic dilated cardiomyopathy.

  2. Effects of lower body positive pressure on muscle sympathetic nerve activity response [correction of respopnse] to head-up tilt.

    Science.gov (United States)

    Fu, Q; Iwase, S; Niimi, Y; Kamiya, A; Kawanokuchi, J; Cui, J; Mano, T

    2001-07-01

    The benefits of lower body positive pressure (LBPP) are generally accepted for clinical treatment in medical emergencies caused by massive bleeding to maintain the systemic blood pressure. They are also used by NASA post spaceflight for preventing orthostatic hypotension in the astronauts. However, controversy still exists concerning the mechanisms underlying LBPP benefits. The purpose of this study was to test the hypothesis that the baroreflex-mediated enhancement in sympathetic activity would be attenuated by LBPP during an orthostatic challenge in humans. Specifically, we studied 1) the sympathetic activity responses by the microneurographic technique, using direct intraneural measurement of muscle sympathetic nerve activity (MSNA); and 2) the contributions of preload and afterload to the chances in MSNA response during orthostasis on application of LBPP. To accomplish these issues, MSNA was recorded microneurographically along with noninvasive measurement of the cardiovascular variables in all the subjects during exposure to a 70 degrees HUT with 30-mm Hg LBPP.

  3. Metastatic hepatocellular carcinoma of the external auditory canal

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This report describes a rare case of metastatic hepatocellular carcinoma (HCC) presenting a huge mass in the left external auditory canal (EAC). The patient was a 55-year-old man with hepatitis B virus-related HCC.He presented to our department with a three-month history of increasing left otalgia, and hearing loss with recent fresh aural bleeding. Histopathologic examination indicated that the tumor was secondary to HCC. Although external irradiation was not effective, the tumor was treated with surgical debulking and high dose rate 192 Ir remote afterloading system (RALS) for postoperative intracavitary irradiation. A review of the literature revealed only five other cases of HCC metastasis to the temporal bone, all of which mainly metastasteed in the internal acoustic meatus. The present case is the first report of HCC metastasis to the EAC.

  4. Implementation of a High-Dose-Rate Brachytherapy Program for Carcinoma of the Cervix in Senegal: A Pragmatic Model for the Developing World

    Energy Technology Data Exchange (ETDEWEB)

    Einck, John P., E-mail: jeinck@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Hudson, Alana [Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta (Canada); Shulman, Adam C. [Overlook Medical Center, Summit, New Jersey (United States); Yashar, Catheryn M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Dieng, Mamadou M.; Diagne, Magatte; Gueye, Latifatou; Gningue, Fama; Gaye, Pape M. [Départemént de Radiothérapie, Institut Joliot-Curie, Hôpital Aristide Le Dantec, Dakar (Senegal); Fisher, Brandon J. [GammaWest Cancer Services, Salt Lake City, Utah (United States); Mundt, Arno J. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Brown, Derek W. [Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta (Canada)

    2014-07-01

    West Africa has one of the highest incidence rates of carcinoma of the cervix in the world. The vast majority of women do not have access to screening or disease treatment, leading to presentation at advanced stages and to high mortality rates. Compounding this problem is the lack of radiation treatment facilities in Senegal and many other parts of the African continent. Senegal, a country of 13 million people, had a single {sup 60}Co teletherapy unit before our involvement and no brachytherapy capabilities. Radiating Hope, a nonprofit organization whose mission is to provide radiation therapy equipment to countries in the developing world, provided a high-dose-rate afterloading unit to the cancer center for curative cervical cancer treatment. Here we describe the implementation of high-dose-rate brachytherapy in Senegal requiring a nonstandard fractionation schedule and a novel treatment planning approach as a possible blueprint to providing this technology to other developing countries.

  5. Non-invasive assessment of left ventricular contractility from end-systolic pressure-volume relation (E(max)) determined by gated radionuclide angiocardiography

    International Nuclear Information System (INIS)

    Left ventricular end-systolic pressure-volume relation has been shown experimentally to be an useful index of left ventricular contractility relatively independent of preload or afterload. But the clinical application has been reported less frequently because of the invasiveness in the measurement of ventricular volume and simultaneous intraventricular pressure. We evaluated this relationship using non-invasive method such as the volume determination by gated radionuclide angiocartiography and the pressure measurement by cuff sphyngomanometer in arm. In measuring ventricular volume, gated radionuclide angiocardiography is a non-invasive method less affected by the geometry of left ventricle. Using the volume by radionuclide and the blood pressure by cuff, non-invasive determination of endsystolic pressure-volume relation provides much clinical usefulness in the assessment of left ventricular contractility

  6. Implementation of a high-dose-rate brachytherapy program for carcinoma of the cervix in Senegal: a pragmatic model for the developing world.

    Science.gov (United States)

    Einck, John P; Hudson, Alana; Shulman, Adam C; Yashar, Catheryn M; Dieng, Mamadou M; Diagne, Magatte; Gueye, Latifatou; Gningue, Fama; Gaye, Pape M; Fisher, Brandon J; Mundt, Arno J; Brown, Derek W

    2014-07-01

    West Africa has one of the highest incidence rates of carcinoma of the cervix in the world. The vast majority of women do not have access to screening or disease treatment, leading to presentation at advanced stages and to high mortality rates. Compounding this problem is the lack of radiation treatment facilities in Senegal and many other parts of the African continent. Senegal, a country of 13 million people, had a single (60)Co teletherapy unit before our involvement and no brachytherapy capabilities. Radiating Hope, a nonprofit organization whose mission is to provide radiation therapy equipment to countries in the developing world, provided a high-dose-rate afterloading unit to the cancer center for curative cervical cancer treatment. Here we describe the implementation of high-dose-rate brachytherapy in Senegal requiring a nonstandard fractionation schedule and a novel treatment planning approach as a possible blueprint to providing this technology to other developing countries.

  7. Hypertonic fluid administration in patients with septic shock: a prospective randomized controlled pilot study.

    Science.gov (United States)

    van Haren, Frank M P; Sleigh, James; Boerma, E Christiaan; La Pine, Mary; Bahr, Mohamed; Pickkers, Peter; van der Hoeven, Johannes G

    2012-03-01

    We assessed the short-term effects of hypertonic fluid versus isotonic fluid administration in patients with septic shock. This was a double-blind, prospective randomized controlled trial in a 15-bed intensive care unit. Twenty-four patients with septic shock were randomized to receive 250 mL 7.2% NaCl/6% hydroxyethyl starch (HT group) or 500 mL 6% hydroxyethyl starch (IT group). Hemodynamic measurements included mean arterial blood pressure (MAP), central venous pressure, stroke volume index, stroke volume variation, intrathoracic blood volume index, gastric tonometry, and sublingual microcirculatory flow as assessed by sidestream dark field imaging. Systolic tissue Doppler imaging velocities of the medial mitral annulus were measured using echocardiography to assess left ventricular contractility. Log transformation of the ratio MAP divided by the norepinephrine infusion rate (log MAP/NE) quantified the combined effect on both parameters. Compared with the IT group, hypertonic solution treatment resulted in an improvement in log MAP/NE (P = 0.008), as well as an increase in systolic tissue Doppler imaging velocities (P = 0.03) and stroke volume index (P = 0.017). No differences between the groups were found for preload parameters (central venous pressure, stroke volume variation, intrathoracic blood volume index) or for afterload parameters (systemic vascular resistance index, MAP). Hypertonic solution treatment decreased the need for ongoing fluid resuscitation (P = 0.046). No differences between groups were observed regarding tonometry or the sublingual microvascular variables. In patients with septic shock, hypertonic fluid administration did not promote gastrointestinal mucosal perfusion or sublingual microcirculatory blood flow in comparison to isotonic fluid. Independent of changes in preload or afterload, hypertonic fluid administration improved the cardiac contractility and vascular tone compared with isotonic fluid. The need for ongoing fluid

  8. SU-E-T-560: Commissioning An HDR Freiburg Flap Applicator for Skin Lesion Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dou, K; Li, B; Lerma, F; Aroumougame, V; Sarfaraz, M [RadAmerica, LLC--MedStar Health, Baltimore, MD (United States); Laser, B; Jacobs, M [Mercy Medical Center, Baltimore, MD (United States)

    2014-06-01

    Purpose: Flexible Freiburg flap used with high dose rate afterloaders is easy to cut into any size for any body site and to dwell with a precise source position, conforms to curved skin surface and then to the planned target. However, unlike intracavity or interstitial situations, incomplete scatter environment due to flap applicators exposed to air might lead to dose difference between the delivered and planned. This research is focused on the dose deviation of incomplete scatter versus full scatter. Methods: A 12x12 cm of Freiburg flap applicator was used for the validation. A Nucletron Oncentra Brachy Ver. 4.3 treatment planning system (TPS) was used for treatment planning. However, no heterogeneity correction incorporated into the brachytherap TPS needs to be considered. A Philips Brilliance CT Big Bore was employed for CT scan. Radiation was delivered using a Nucletron HDR remote afterloader system. A 10cm bolus was used to cover the flap for obtaining a full scatter. An OSL, ion chamber, and Gafchromic EBT2 film were used for commissioning the flap applicator. Results: The applicator calibration at 5mm depth was performed using an OSL dosimeter. Applicator source dwelling positions with 1D and 2D array exposed to and recorded by Gafchromic EBT2 film showed an agreement within 1mm. 1D array of Freiburg flap exhibited 4.2% cooler in dose with incomplete scatter than full scatter. 2D array showed 7.1% lower in dose for incomplete scatter than full scatter. The deviation was found more than 10% beyond 8cm in depth. Conclusion: Significant dose deviation caused by the incomplete scatter environment was found to be 7.1% at 1cm depth. This deviation was increased with increasing depth. The inaccuracy resulted from the incomplete scatter can be fixed by either placing a bolus on the top of the flap or making the plan at least 7% hotter.

  9. Impact of acute changes of left ventricular contractility on the transvalvular impedance: validation study by pressure-volume loop analysis in healthy pigs.

    Directory of Open Access Journals (Sweden)

    Vincenzo Lionetti

    Full Text Available BACKGROUND: The real-time and continuous assessment of left ventricular (LV myocardial contractility through an implanted device is a clinically relevant goal. Transvalvular impedance (TVI is an impedentiometric signal detected in the right cardiac chambers that changes during stroke volume fluctuations in patients. However, the relationship between TVI signals and LV contractility has not been proven. We investigated whether TVI signals predict changes of LV inotropic state during clinically relevant loading and inotropic conditions in swine normal heart. METHODS: The assessment of RVTVI signals was performed in anesthetized adult healthy anesthetized pigs (n = 6 instrumented for measurement of aortic and LV pressure, dP/dtmax and LV volumes. Myocardial contractility was assessed with the slope (Ees of the LV end systolic pressure-volume relationship. Effective arterial elastance (Ea and stroke work (SW were determined from the LV pressure-volume loops. Pigs were studied at rest (baseline, after transient mechanical preload reduction and afterload increase, after 10-min of low dose dobutamine infusion (LDDS, 10 ug/kg/min, i.v, and esmolol administration (ESMO, bolus of 500 µg and continuous infusion of 100 µg·kg-1·min-1. RESULTS: We detected a significant relationship between ESTVI and dP/dtmax during LDDS and ESMO administration. In addition, the fluctuations of ESTVI were significantly related to changes of the Ees during afterload increase, LDDS and ESMO infusion. CONCLUSIONS: ESTVI signal detected in right cardiac chamber is significantly affected by acute changes in cardiac mechanical activity and is able to predict acute changes of LV inotropic state in normal heart.

  10. Hypertonic fluid administration in patients with septic shock: a prospective randomized controlled pilot study.

    Science.gov (United States)

    van Haren, Frank M P; Sleigh, James; Boerma, E Christiaan; La Pine, Mary; Bahr, Mohamed; Pickkers, Peter; van der Hoeven, Johannes G

    2012-03-01

    We assessed the short-term effects of hypertonic fluid versus isotonic fluid administration in patients with septic shock. This was a double-blind, prospective randomized controlled trial in a 15-bed intensive care unit. Twenty-four patients with septic shock were randomized to receive 250 mL 7.2% NaCl/6% hydroxyethyl starch (HT group) or 500 mL 6% hydroxyethyl starch (IT group). Hemodynamic measurements included mean arterial blood pressure (MAP), central venous pressure, stroke volume index, stroke volume variation, intrathoracic blood volume index, gastric tonometry, and sublingual microcirculatory flow as assessed by sidestream dark field imaging. Systolic tissue Doppler imaging velocities of the medial mitral annulus were measured using echocardiography to assess left ventricular contractility. Log transformation of the ratio MAP divided by the norepinephrine infusion rate (log MAP/NE) quantified the combined effect on both parameters. Compared with the IT group, hypertonic solution treatment resulted in an improvement in log MAP/NE (P = 0.008), as well as an increase in systolic tissue Doppler imaging velocities (P = 0.03) and stroke volume index (P = 0.017). No differences between the groups were found for preload parameters (central venous pressure, stroke volume variation, intrathoracic blood volume index) or for afterload parameters (systemic vascular resistance index, MAP). Hypertonic solution treatment decreased the need for ongoing fluid resuscitation (P = 0.046). No differences between groups were observed regarding tonometry or the sublingual microvascular variables. In patients with septic shock, hypertonic fluid administration did not promote gastrointestinal mucosal perfusion or sublingual microcirculatory blood flow in comparison to isotonic fluid. Independent of changes in preload or afterload, hypertonic fluid administration improved the cardiac contractility and vascular tone compared with isotonic fluid. The need for ongoing fluid

  11. Management of postoperative radiation injury of the urinary bladder by hyperbaric oxygen (HBO)

    Energy Technology Data Exchange (ETDEWEB)

    Peusch-Dreyer, D.; Dreyer, K.H. [Zentrum fuer Tauch- und Ueberdruckmedizin (ZETUeM), Bremen (Germany); Mueller, C.D. [Druckkammerzentrum Magdeburg (Germany); Carl, U. [Klinik fuer Strahlentherapie und Radioonkologie, Universitaet Duesseldorf (Germany)

    1998-11-01

    Aim: In many case reports the success of treatment of late complications of radiotherapy with hyperbaric oxygenation (HBO) has been shown. This synopsis attempts to review HBO in the treatment of chronic radiation injury of the bladder. Patients and methods: Three female patients who had developed urge-incontinence after a Wertheim operation and combined brachy-teletherapy with cobalt-60 and afterloading and did not respond to various drug therapies, were treated with HBO to a maximum of 40 applications. Results: In all patients HBO haltered and inverted the dynamic process underlying chronic bladder changes after irradiation. Rationales for the HBO are the reduction of tissue hypoxia and the induction of neoangiogenesis. Conclusions: There are no prospective trials up to date showing the benefit of HBO to urinary disorders caused by radiation cystitis. The positive results of our retrospective study should encourage clinicians to initiate prospective studies with the use of HBO in the treatment of radiation cystitis. (orig.) [Deutsch] Ziel: Ueber die erfolgreiche Anwendung der hyperbaren Sauerstofftherapie (HBO) zur Behandlung von Strahlenspaetkomplikationen ist in zahlreichen Publikationen berichtet worden. Ziel dieser Arbeit ist es, den Einsatz der HBO bei der Behandlung von Miktionsbeschwerden bei chronisch radiogenen Harnblasenschaeden zu bewerten. Patienten und Methode: Drei Patientinnen, die nach einer kombinierten Brachyteletherapie mit Kobalt 60 und Afterloading nach Wertheim-Operation unter einer medikamentoes nicht zu beeinflussenden Urge-Inkontinenz litten, wurden der HBO mit maximal 40 Behandlungen zugefuehrt. Ergebnisse: Die HBO war bei allen Patientinnen in der Lage, den dynamischen Krankheitsprozess der Strahlenzystitis aufzuhalten und teilweise umzukehren. Grundlage hierfuer ist die Beseitigung der Gewebshypoxie. Dieses wiederum stellt die Voraussetzung fuer eine Neovaskularisation im bestrahlten Gewebe dar. Schlussfolgerung: Prospektive Studien

  12. Implementation of microsource high dose rate (mHDR) brachytherapy in developing countries

    International Nuclear Information System (INIS)

    Brachytherapy using remote afterloading of a single high dose rate 192Ir microsource was developed in the 1970s. After its introduction to clinics, this system has spread rapidly among developed Member States and has become a highly desirable modality in cancer treatment. This technique is now gradually being introduced to the developing Member States. The 192Ir sources are produced with a high specific activity. This results in a high dose rate (HDR) to the tumour and shorter treatment times. The high specific activity simultaneously results in a much smaller source (so-called micro source, around I mm in diameter) which may be easily inserted into tissue through a thin delivery tube, the so-called interstitial treatment, as well as easily inserted into body cavities, the so-called intracavitary or endoluminal treatment. Another advantage is the ability to change dwell time (the time a source remains in one position) of the stepping source which allows dose distribution to match the target volume more closely. The purpose of this TECDOC is to advise radiation oncologists, medical physicists and hospital administrators in hospitals which are planning to introduce 192Ir microsource HDR (mHDR) remote afterloading systems. The document supplements IAEA-TECDOC-1040, Design and Implementation of a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects, and will facilitate implementation of this new brachytherapy technology, especially in developing countries. The operation of the system, 'how to use the system', is not within the scope of this document. This TECDOC is based on the recommendations of an Advisory Group meeting held in Vienna in April 1999

  13. l-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men.

    Science.gov (United States)

    Figueroa, Arturo; Alvarez-Alvarado, Stacey; Jaime, Salvador J; Kalfon, Roy

    2016-07-01

    Combined isometric exercise or metaboreflex activation (post-exercise muscle ischaemia (PEMI)) and cold pressor test (CPT) increase cardiac afterload, which may lead to adverse cardiovascular events. l-Citrulline supplementation (l-CIT) reduces systemic arterial stiffness (brachial-ankle pulse wave velocity (baPWV)) at rest and aortic haemodynamic responses to CPT. The aim of this study was to determine the effect of l-CIT on aortic haemodynamic and baPWV responses to PEMI+CPT. In all, sixteen healthy, overweight/obese males (age 24 (sem 6) years; BMI 29·3 (sem 4·0) kg/m2) were randomly assigned to placebo or l-CIT (6 g/d) for 14 d in a cross-over design. Brachial and aortic systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), aortic augmented pressure (AP), augmentation index (AIx), baPWV, reflection timing (Tr) and heart rate (HR) were evaluated at rest and during isometric handgrip exercise (IHG), PEMI and PEMI+CPT at baseline and after 14 d. No significant effects were evident after l-CIT at rest. l-CIT attenuated the increases in aortic SBP and wave reflection (AP and AIx) during IHG, aortic DBP, MAP and AIx during PEMI, and aortic SBP, DBP, MAP, AP, AIx and baPWV during PEMI+CPT compared with placebo. HR and Tr were unaffected by l-CIT in all conditions. Our findings demonstrate that l-CIT attenuates aortic blood pressure and wave reflection responses to exercise-related metabolites. Moreover, l-CIT attenuates the exaggerated arterial stiffness response to combined metaboreflex activation and cold exposure, suggesting a protective effect against increased cardiac afterload during physical stress. PMID:27160957

  14. SU-E-T-457: Design and Characterization of An Economical 192Ir Hemi-Brain Small Animal Irradiator

    Energy Technology Data Exchange (ETDEWEB)

    Grams, M; Wilson, Z; Sio, T; Beltran, C; Tryggestad, E; Gupta, S; Blackwell, C; McCollough, K; Sarkaria, J; Furutani, K [Mayo Clinic, Rochester, MN (United States)

    2014-06-01

    Purpose: To describe the design and dosimetric characterization of a simple and economical small animal irradiator. Methods: A high dose rate 192Ir brachytherapy source from a commercially available afterloader was used with a 1.3 centimeter thick tungsten collimator to provide sharp beam penumbra suitable for hemi-brain irradiation of mice. The unit is equipped with continuous gas anesthesia to allow robust animal immobilization. Dosimetric characterization of the device was performed with Gafchromic film. The penumbra from the small animal irradiator was compared under similar collimating conditions to the penumbra from 6 MV photons, 6 MeV electrons, and 20 MeV electrons from a linear accelerator as well as 300 kVp photons from an orthovoltage unit and Monte Carlo simulated 90 MeV protons. Results: The tungsten collimator provides a sharp penumbra suitable for hemi-brain irradiation, and dose rates on the order of 200 cGy/minute were achieved. The sharpness of the penumbra attainable with this device compares favorably to those measured experimentally for 6 MV photons, and 6 and 20 MeV electron beams from a linear accelerator. Additionally, the penumbra was comparable to those measured for a 300 kVp orthovoltage beam and a Monte Carlo simulated 90 MeV proton beam. Conclusions: The small animal irradiator described here can be built for under $1,000 and used in conjunction with any commercial brachytherapy afterloader to provide a convenient and cost-effective option for small animal irradiation experiments. The unit offers high dose rate delivery and sharp penumbra, which is ideal for hemi-brain irradiation of mice. With slight modifications to the design, irradiation of sites other than the brain could be accomplished easily. Due to its simplicity and low cost, the apparatus described is an attractive alternative for small animal irradiation experiments requiring a sharp penumbra.

  15. SU-E-T-457: Design and Characterization of An Economical 192Ir Hemi-Brain Small Animal Irradiator

    International Nuclear Information System (INIS)

    Purpose: To describe the design and dosimetric characterization of a simple and economical small animal irradiator. Methods: A high dose rate 192Ir brachytherapy source from a commercially available afterloader was used with a 1.3 centimeter thick tungsten collimator to provide sharp beam penumbra suitable for hemi-brain irradiation of mice. The unit is equipped with continuous gas anesthesia to allow robust animal immobilization. Dosimetric characterization of the device was performed with Gafchromic film. The penumbra from the small animal irradiator was compared under similar collimating conditions to the penumbra from 6 MV photons, 6 MeV electrons, and 20 MeV electrons from a linear accelerator as well as 300 kVp photons from an orthovoltage unit and Monte Carlo simulated 90 MeV protons. Results: The tungsten collimator provides a sharp penumbra suitable for hemi-brain irradiation, and dose rates on the order of 200 cGy/minute were achieved. The sharpness of the penumbra attainable with this device compares favorably to those measured experimentally for 6 MV photons, and 6 and 20 MeV electron beams from a linear accelerator. Additionally, the penumbra was comparable to those measured for a 300 kVp orthovoltage beam and a Monte Carlo simulated 90 MeV proton beam. Conclusions: The small animal irradiator described here can be built for under $1,000 and used in conjunction with any commercial brachytherapy afterloader to provide a convenient and cost-effective option for small animal irradiation experiments. The unit offers high dose rate delivery and sharp penumbra, which is ideal for hemi-brain irradiation of mice. With slight modifications to the design, irradiation of sites other than the brain could be accomplished easily. Due to its simplicity and low cost, the apparatus described is an attractive alternative for small animal irradiation experiments requiring a sharp penumbra

  16. Identifying early changes in myocardial microstructure in hypertensive heart disease.

    Directory of Open Access Journals (Sweden)

    Pranoti Hiremath

    Full Text Available The transition from healthy myocardium to hypertensive heart disease is characterized by a series of poorly understood changes in myocardial tissue microstructure. Incremental alterations in the orientation and integrity of myocardial fibers can be assessed using advanced ultrasonic image analysis. We used a modified algorithm to investigate left ventricular myocardial microstructure based on analysis of the reflection intensity at the myocardial-pericardial interface on B-mode echocardiographic images. We evaluated the extent to which the novel algorithm can differentiate between normal myocardium and hypertensive heart disease in humans as well as in a mouse model of afterload resistance. The algorithm significantly differentiated between individuals with uncomplicated essential hypertension (N = 30 and healthy controls (N = 28, even after adjusting for age and sex (P = 0.025. There was a trend in higher relative wall thickness in hypertensive individuals compared to controls (P = 0.08, but no difference between groups in left ventricular mass (P = 0.98 or total wall thickness (P = 0.37. In mice, algorithm measurements (P = 0.026 compared with left ventricular mass (P = 0.053 more clearly differentiated between animal groups that underwent fixed aortic banding, temporary aortic banding, or sham procedure, on echocardiography at 7 weeks after surgery. Based on sonographic signal intensity analysis, a novel imaging algorithm provides an accessible, non-invasive measure that appears to differentiate normal left ventricular microstructure from myocardium exposed to chronic afterload stress. The algorithm may represent a particularly sensitive measure of the myocardial changes that occur early in the course of disease progression.

  17. Rationale, design and methodology for Intraventricular Pressure Gradients Study: a novel approach for ventricular filling assessment in normal and falling hearts

    Directory of Open Access Journals (Sweden)

    Vouga Luís

    2011-05-01

    Full Text Available Abstract Background Intraventricular pressure gradients have been described between the base and the apex of the left ventricle during early diastolic ventricular filling, as well as, their increase after systolic and diastolic function improvement. Although, systolic gradients have also been observed, data are lacking on their magnitude and modulation during cardiac dysfunction. Furthermore, we know that segmental dysfunction interferes with the normal sequence of regional contraction and might be expected to alter the physiological intraventricular pressure gradients. The study hypothesis is that systolic and diastolic gradients, a marker of normal left ventricular function, may be related to physiological asynchrony between basal and apical myocardial segments and they can be attenuated, lost entirely, or even reversed when ventricular filling/emptying is impaired by regional acute ischemia or severe aortic stenosis. Methods/Design Animal Studies: Six rabbits will be completely instrumented to measuring apex to outflow-tract pressure gradient and apical and basal myocardial segments lengthening changes at basal, afterloaded and ischemic conditions. Afterload increase will be performed by abruptly narrowing or occluding the ascending aorta during the diastole and myocardial ischemia will be induced by left coronary artery ligation, after the first diagonal branch. Patient Studies: Patients between 65-80 years old (n = 12, both genders, with severe aortic stenosis referred for aortic valve replacement will be selected as eligible subjects. A high-fidelity pressure-volume catheter will be positioned through the ascending aorta across the aortic valve to measure apical and outflow-tract pressure before and after aortic valve replacement with a bioprosthesis. Peak and average intraventricular pressure gradients will be recorded as apical minus outflow-tract pressure and calculated during all diastolic and systolic phases of cardiac cycle

  18. Levosimendan Relaxes Pulmonary Arteries and Veins in Precision-Cut Lung Slices - The Role of KATP-Channels, cAMP and cGMP.

    Directory of Open Access Journals (Sweden)

    Annette D Rieg

    Full Text Available Levosimendan is approved for left heart failure and is also used in right heart failure to reduce right ventricular afterload. Despite the fact that pulmonary arteries (PAs and pulmonary veins (PVs contribute to cardiac load, their responses to levosimendan are largely unknown.Levosimendan-induced vasorelaxation of PAs and PVs was studied in precision-cut lung slices from guinea pigs by videomicroscopy; baseline luminal area was defined as 100%. Intracellular cAMP- and cGMP-levels were measured by ELISA and NO end products were determined by the Griess reaction.Levosimendan relaxed control PVs (116% and those pre-constricted with an endothelinA-receptor agonist (119%. PAs were only relaxed if pre-constricted (115%. Inhibition of KATP-channels (glibenclamide, adenyl cyclase (SQ 22536 and protein kinase G (KT 5823 largely attenuated the levosimendan-induced relaxation in control PVs, as well as in pre-constricted PAs and PVs. Inhibition of BKCa (2+-channels (iberiotoxin and Kv-channels (4-aminopyridine only contributed to the relaxant effect of levosimendan in pre-constricted PAs. In both PAs and PVs, levosimendan increased intracellular cAMP- and cGMP-levels, whereas NO end products remained unchanged. Notably, basal NO-levels were higher in PVs. The KATP-channel activator levcromakalim relaxed PAs dependent on cAMP/PKA/PKG and increased cAMP-levels in PAs.Levosimendan initiates complex and divergent signaling pathways in PAs and PVs. Levosimendan relaxes PAs and PVs primarily via KATP-channels and cAMP/cGMP; in PAs, BKCa (2+- and Kv-channels are also involved. Our findings with levcromakalim do further suggest that in PAs the activation of KATP-channels leads to the production of cAMP/PKA/PKG. In conclusion, these results suggest that levosimendan might reduce right ventricular afterload by relaxation of PAs as well as pulmonary hydrostatic pressure and pulmonary edema by relaxation of PVs.

  19. The relationship of pulmonary vascular resistance and compliance to pulmonary artery wedge pressure during submaximal exercise in healthy older adults

    Science.gov (United States)

    Wright, Stephen P.; Granton, John T.; Esfandiari, Sam; Goodman, Jack M.

    2016-01-01

    Key points A consistent inverse hyperbolic relationship has been observed between pulmonary vascular resistance and compliance, although changes in pulmonary artery wedge pressure (PAWP) may modify this relationship.This relationship predicts that pulmonary artery systolic, diastolic and mean pressure maintain a consistent relationship relative to the PAWP.We show that, in healthy exercising human adults, both pulmonary vascular resistance and compliance decrease in relation to exercise‐associated increases in PAWP.Pulmonary artery systolic, diastolic and mean pressures maintain a consistent relationship with one another, increasing linearly with increasing PAWP.Increases in PAWP in the setting of exercise are directly related to a decrease in pulmonary vascular compliance, despite small decreases in pulmonary vascular resistance, thereby increasing the pulsatile afterload to the right ventricle. Abstract The resistive and pulsatile components of right ventricular afterload (pulmonary vascular resistance, Rp; compliance, Cp) are related by an inverse hyperbolic function, expressed as their product known as RpCp‐time. The RpCp‐time exhibits a narrow range, although it may be altered by the pulmonary artery wedge pressure (PAWP). Identifying the determinants of RpCp‐time should improve our understanding of the physiological behaviour of pulmonary arterial systolic (PASP), diastolic (PADP) and mean (mPAP) pressures in response to perturbations. We examined the effect of exercise in 28 healthy non‐athletic adults (55 ± 6 years) who underwent right heart catheterization to assess haemodynamics and calculate Rp and Cp. Measurements were made at rest and during two consecutive 8–10 min stages of cycle ergometry, at targeted heart‐rates of 100 beats min–1 (Light) and 120 beats min–1 (Moderate). Cardiac output increased progressively during exercise. PASP, PADP, mPAP and PAWP increased for Light exercise, without any further rise for Moderate

  20. High dose rate 192Ir calibration: Indonesia experiences

    International Nuclear Information System (INIS)

    Indonesia with a population of more than 200 Million people which spread on about 5000 islands, up to now only has 23 radiotherapy centers and some not active anymore. As mention by Parkin et al that Cervix/Utery and breast cancer are the most estimated numbers of new cases of cancers in women for developing countries, stomach and lung cancers in men. Indonesia as a developing country is likely similar to other developing countries on numbers of new cases of cancers in women. But quite different in men, in Indonesia the most common cancers are nasopharynx and thyroid cancers. The use of lr-192 sources in high dose-rate (HDR) remotely afterloaded brachytherapy treatments have greatly increased in recent years and variety of such sources are commercially available. Nine radiotherapy centers in Indonesia installed Nucletron microSelectron HDR remote afterloader. Based on the data of CiptoMangunkusurno Hospital, Jakarta that the most common cancers are the cervix, breast, nasopharynx and thyroid cancers which of percentage are about 31%, 25 %, 13%, and 6 % respectively. It means that the use of HDR 192Ir brachytherapy has to be an effective tool in the treatments. Two methods have been studied and applied to calibrate HDR 192Ir brachytherapy in Indonesia, especially for Nucletron microSelectron HDR 192lr remote afterloader brachytherapy. Calibration of HDR 192Ir brachytherapy source has been done by Cavity lonization Chamber and with Well Type lonization Chamber. First, 0.6 cc of NE Farmer type dosimeter that was calibrated to 60Co and 250 kV of x-rays in air kerma was used in this experiment. Position of measurement (detector and source) at the center of the room and about 1 meter from the floor. Eight variation of distances from 10 cm to 40 cms have been carried out measurement as recommended by IAEA-TECDOC-1079. Correction have been given for scatters, non-uniformity, and attenuation. To solve the problem of scatter correction factor was used Matlab programming. A

  1. THE FIRST DERIVATIVE OF APEX CARDIOGRAM AND ITS UTILIZING FOR DETERMINING SOME SYSTOLIC AND DIASTOLIC TIME INTERVALS IN MAN

    Directory of Open Access Journals (Sweden)

    NIKOLAI KOLEV

    1980-10-01

    Full Text Available To determine the usefulness of the time intervals obtained from the first derivative of apex cardiogram (dA/dt in assessing contraction and relaxation, 20 hemodynamically and angiographical1y investigated patients with coronary artery disease and 29 patients with hypertensive heart disease were studied."nAs a control group there were used 50 normal subjects. Since contraction and relaxation is dependent on preload and afterload, the time interval from R wave of electrocardiogram to the positive peak of dA/dt (R to dA/dt and two relaxation parameters derived from negative peak dA/dt were investigated, early relaxation index (ERI and total relaxation index (TRI. In patients with coronary artery disease all of these parameters were augmen- -- ted (R to dA/dt: 121 + 14 controls; ERI: 13.1 149 + 30 Versus + 8 - msec versus 76 + 14 msec for versus 4.3 + 5 in controls; TRI 71 + 18 for controls and also pat ients with hypertensive heart disease s howed similar change s ( ~ to dA/ cant c orrelatio ns between these indexes a nd some i nternally par ame t e r s of myocar d i a l performance were ob s erved . These findings indicate that s ystolic and diastolic time intervals me a s ured f rom the firs t de r i v a t i v e o f apex ca r d iogr am may be used a s a reliable indices for evaluation o f contraction and relaxation independently of p r e loa d and afterload. dt : 115 -+ 15 ms ec ; ERI: 9 . 5 +- 6 ; TRI: 81 +- 19 .Signi f I Measurement o f sustolic and diastolic time interval Is for c a rd i ac evaluation, such as isovolumetric c ont r a ction, preejection period, l eft ventricular ejection time and isovolumetric r elaxation time has been emphasized"nby many authors. However, these intervals are infl- •"nuenced by factors extraneous to contractility and rela1,2 xation, such as variations in preload and afterload To ov e r c ome the latter d i f f i cu l t y , Reale 3 proposed t o determine the time interval fr om ons et of ventricular

  2. Quinapril therapy in patients with chronic mitral regurgitation.

    Science.gov (United States)

    Schön, H R; Schröter, G; Barthel, P; Schömig, A

    1994-05-01

    Pre- and afterload reduction is known to have beneficial effects in patients with chronic mitral regurgitation. To date, no controlled study has been reported analyzing the long term influence of angiotensin-converting enzyme inhibitor treatment on patients with chronic mitral regurgitation. Therefore the aim of this study was to assess the effects of one year angiotensin-converting enzyme inhibition with quinapril on myocardial performance in patients with chronic mitral regurgitation. Twelve patients with moderate to severe isolated chronic mitral regurgitation and no coronary disease on coronary angiography were studied under control conditions and followed up until one year of quinapril therapy (10-20mg/day) using echocardiography and simultaneous right heart catheterization, and radionuclide ventriculography at rest and exercise. As the result of a significant pre- and afterload reduction after one year quinapril treatment regurgitant fraction fell from 0.43 +/- 0.10 at control before therapy to 0.25 +/- 0.08 (p = 0.0001), left ventricular end-diastolic volume was reduced from 146 +/- 26 to 109 +/- 24 ml/m2 (p = 0.0001) and end-systolic volume decreased from 63 +/- 43 to 47 +/- 29 ml/m2 (p = 0.02). Left ventricular ejection fraction at control averaged 0.59 +/- 0.20 at rest, increased to 0.65 +/- 0.21 with maximum exercise and was unchanged after one year quinapril therapy. After one year treatment left ventricular mass was reduced by 15% (p = 0.0004) and septal wall thickness decreased from 11.8 +/- 0.7 to 10.8 +/- 0.8 mm (p = 0.0006). Moreover, there was significant functional improvement of nearly one NYHA class after one year quinapril therapy. In conclusion, in patients with chronic mitral regurgitation long term angiotensin-converting enzyme inhibition with quinapril reduces regurgitation and decreases left ventricular size and mass thereby demonstrating functional improvement. In addition, these data suggest that angiotensin-converting enzyme inhibition

  3. Pelvic interstitial brachytherapy - improving the therapeutic ratio with magnetic resonance imaging and optimization

    International Nuclear Information System (INIS)

    Introduction Interstitial brachytherapy in the pelvic region is often hampered by the radiation oncologist's inability to precisely differentiate tumor versus normal tissue during the planning and implantation procedures, often resulting in either excessive or incomplete coverage of tumor volume. The marked improvement in pelvic imaging seen with magnetic resonance, in conjunction with isodose optimization programs for remote-afterloading units, has created an opportunity to significantly improve the therapeutic ratio. Methods From 1992-1995, 23 interstitial perineal templates were performed in 22 patients with pelvic malignancies, using the pulsed low-dose-rate Selectron with dose optimization. MR imaging was performed immediately prior to the implant, with a MUPIT placed against the perineum and a vaginal obturator in place. These images were used for tumor volume measurements, determination of the number, depth and angle of needles required for the implant, and identification of position of normal tissues (rectum, small bowel, bladder) relative to the tumor. After implantation of stainless steel needles, orthogonal radiographs were obtained for isodose calculation, and planning carried out with isodose optimization. Patients were followed closely on a routine schedule, until time of last visit or until death. Every effort possible was made to assess local disease status at time of death. Results Sixteen patients with primary disease (14 cervix, 1 vulva, 1 vagina) and 6 with recurrent (2 with prior radiation) were implanted, all but 3 with curative intent. Nine patients with advanced cervix or vulvar cancer received concomitant chemotherapy (5FU + platinum or mitomycin-C) with the external beam therapy. At a median follow-up of 18.1 months for all cases, only three patients have failed locally for an actuarial local control of 85% at 1.5 years. Nine patients are alive and free of disease, 8 are alive with distant disease only (mean follow-up of 19.1 months), 2

  4. Noninvasive ventilation in patients with acute cardiogenic pulmonary edema

    Directory of Open Access Journals (Sweden)

    Andrea Bellone

    2013-07-01

    Full Text Available The term noninvasive ventilation (NIV encompasses two different modes of delivering positive airway pressure, namely continuous positive airway pressure (CPAP and bilevel positive airway pressure (bilevel-PAP. The two modes are different since CPAP does not actively assist inspiration whereas bilevel-PAP does. Bilevel-PAP is a type of noninvasive ventilation that helps keep the upper airways of the lungs open by providing a flow of air delivered through a face mask. The air is pressurized by a machine, which delivers it to the face mask through long, plastic hosing. With bilevel-PAP, the doctor prescribes specific alternating pressures: a higher pressure is used to breathe in (inspiratory positive airway pressure and a lower pressure is used to breath out (expiratory positive airway pressure. Noninvasive ventilation has been shown to reduce the rate of tracheal intubation. The main indications are exacerbation of chronic obstructive pulmonary disease and acute cardiogenic pulmonary edema (ACPE. This last is a common cause of respiratory failure with high incidence and high mortality rate. Clinical findings of ACPE are related to the increased extra-vascular water in the lungs and the resulting reduced lung compliance, increased airway resistance and elevated inspiratory muscle load which generates a depression in pleural pressure. These large pleural pressure swings are responsible for hemodynamic changes by increasing left ventricular afterload, myocardial transmural pressure, and venous return. These alterations can be detrimental to patients with left ventricular systolic dysfunction. Under these circumstances, NIV, either by CPAP or bilevel-PAP, improves vital signs, gas exchange, respiratory mechanics and hemodynamics by reducing left ventricular afterload and preload. In the first randomized study which compared the effectiveness of CPAP plus medical treatment vs medical treatment alone, the CPAP group showed a significant decrease in its

  5. Intelligent Li ion battery management based on a digital signal processor for a moving actuator total artificial heart.

    Science.gov (United States)

    Kim, W E; Ahn, J M; Choi, S W; Min, B G

    1997-01-01

    An intelligent Li Ion battery management (ILBM) system was developed based on a digital signal processor (DSP). Instead of using relatively complicated hardware charging control, a DSP algorithm was used, and favorable characteristics in volume, mass, and temperature increase of the implantable battery were achieved. In vitro tests were performed to evaluate the DSP based algorithm for Li Ion charging control (24 V dc motor input power 16 W, 5 L/min, 100 mmHg afterload). In this article, the first improvement was volume reduction using a Li Ion battery (3.6 V/Cell, 900 mA, seven cells: 25.2 V, 22.7 W). Its volume and mass were decreased by 40% and 50% respectively (40*55*75 mm, 189 g), compared to previously reported results, with total energy capacity increased by 110% (more than 60 min vs 25 min run time in the other battery). The second improvement includes the ILBM, which can control the performance detection for each unit cell and has a low temperature rise. The ILBM's unit cell energy detection was important because the low performance of one cell dropped to 50% of the total performance along with a 20% increase in surface temperature. All electronics for a transcutaneous energy transmission (TET), battery, and telemetry were finalized for hybridization and used for total artificial heat (TAH) implantation.

  6. Intracavitary applicator in relation to complications of pelvic radiation: the Ernst system

    International Nuclear Information System (INIS)

    Case studies were reviewed for 100 consecutive patients with carcinoma of the cervix, Stages I to III, who were treated prior to 1968 at a large municipal hospital in New York City. Treatments consisted of orthovoltage therapy prior to or following intracavitary radium. A 250 kV x-ray unit delivered a 3000 rad tumor dose in 3 weeks through four oblique fields. Intracavitary radium delivered 6000 to 7200 mg hr using the Ernst applicator. The 9% incidence of fistulae was 4-fold higher than that found in subsequent years using 60Co teletherapy and the afterloading Fletcher-Suit applicator. A review of the dosimetry relating to the use of the Ernst applicator demonstrates inherent structural characteristics which lend themselves to such complications. Where less than an ideal application is possible, this rigid applicator compacts itself in accordion-like fashion, producing a so-called short-system. Coupled with a reduced source to applicator-surface distance, such applications result in unacceptable dose anisotropy and excessive radiation of critical structures where a predetermined dose is to be delivered to anatomic Point A. Information gleaned from this study can be extrapolated to other rigid unprotected short-surface distance intra-vaginal applicators that have proliferated in recent years

  7. Tolerance of the carotid-sheath contents to brachytherapy: an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Werber, J.L.; Sood, B.; Alfieri, A.; McCormick, S.A.; Vikram, B. (Department of Otolaryngology--Head and Neck Surgery, New York Medical College, Beth Israel (USA))

    1991-06-01

    Tumor invasion of the carotid artery is a potential indication for brachytherapy, which delivers a high dose of irradiation to residual tumor while limiting the dose to adjacent healthy tissues. The tolerance of carotid-sheath contents to varying doses of brachytherapy, however, has not been clearly established. In order to evaluate brachytherapy effects on carotid-sheath contents, after-loading catheters were implanted bilaterally in 3 groups of 6 rabbits each (18 rabbits). Iridium 192 brachytherapy doses of either 5000 cGy (rad), 9000 cGy, or 13,000 cGy were delivered unilaterally, with the contralateral neck serving as a nonirradiated control in each animal. There were no carotid ruptures and wound healing was normal. Two animals from each group were killed at 6, 20, and 48 weeks. Even at the highest dose (13,000 cGy), nerve conduction studies performed on the vagus nerve prior to sacrifice revealed no increased latency, histologic changes were minimal, and carotid arteries were patent. These observations suggest that the carotid-sheath contents in healthy rabbits could tolerate high doses (up to 13,000 cGy) of low-dose-rate interstitial brachytherapy without complications.

  8. Measurement uncertainty in pulmonary vascular input impedance and characteristic impedance estimated from pulsed-wave Doppler ultrasound and pressure: clinical studies on 57 pediatric patients.

    Science.gov (United States)

    Tian, Lian; Hunter, Kendall S; Kirby, K Scott; Ivy, D Dunbar; Shandas, Robin

    2010-06-01

    Pulmonary vascular input impedance better characterizes right ventricular (RV) afterload and disease outcomes in pulmonary hypertension compared to the standard clinical diagnostic, pulmonary vascular resistance (PVR). Early efforts to measure impedance were not routine, involving open-chest measurement. Recently, the use of pulsed-wave (PW) Doppler-measured velocity to non-invasively estimate instantaneous flow has made impedance measurement more practical. One critical concern remains with clinical use: the measurement uncertainty, especially since previous studies only incorporated random error. This study utilized data from a large pediatric patient population to comprehensively examine the systematic and random error contributions to the total impedance uncertainty and determined the least error prone methodology to compute impedance from among four different methods. We found that the systematic error contributes greatly to the total uncertainty and that one of the four methods had significantly smaller propagated uncertainty; however, even when this best method is used, the uncertainty can be large for input impedance at high harmonics and for the characteristic impedance modulus. Finally, we found that uncertainty in impedance between normotensive and hypertensive patient groups displays no significant difference. It is concluded that clinical impedance measurement would be most improved by advancements in instrumentation, and the best computation method is proposed for future clinical use of the input impedance.

  9. The role of dosimetry audits in radiotherapy quality assurance: The 8 year experience in Greek radiotherapy and brachytherapy centers

    International Nuclear Information System (INIS)

    Twenty six (26) radiotherapy (RT) centers (public and private) operate in Greece up to date (Apr. 2010), where 36 linacs and 8 Co-60 teletherapy units are being used, producing 64 photon beams (Co60, 6-23 MV) and 126 electron beams (4-21 MeV) in total. Furthermore, 7 HDR Ir192 and 2 MDR/LDR Cs137 remote afterloading brachytherapy systems operate. The Ionizing Radiation Calibration Laboratory (IRCL) of the Greek Atomic Energy Commission (GAEC) runs dosimetry audits in all Greek radiotherapy centers by means of on-site visits, in order to assess the dose accuracy, to identify and resolve problems on dosimetry, to provide intercomparisons to hospitals and disseminate the IAEA TRS 398 protocol. Additionally, the GAEC's IRCL calibrates the reference dosimetry equipment of all RT centers, in terms of absorbed dose in water at Co60 beam quality and air kerma strength at Ir192 qualities. The GAEC's dosimetry audit is a continuous process: The 1st round has been completed for the photons beams (2002 - 2006), electrons (2002 - 2008) and brachytherapy (2006-2009). The 2nd round is at the final stage for photons (2006-2010) and in progress for the rest, while a 3rd round for photons has already been initiated. The audit results for the photons 1st round have been published. This work presents the results of these audits and focuses on the improvements of RT centers' dosimetry during the successive audit rounds

  10. Prospective multi-center trial utilizing electronic brachytherapy for the treatment of endometrial cancer

    International Nuclear Information System (INIS)

    A modified form of high dose rate (HDR) brachytherapy has been developed called Axxent Electronic Brachytherapy (EBT). EBT uses a kilovolt X-ray source and does not require treatment in a shielded vault or a HDR afterloader unit. A multi-center clinical study was carried out to evaluate the success of treatment delivery, safety and toxicity of EBT in patients with endometrial cancer. A total of 15 patients with stage I or II endometrial cancer were enrolled at 5 sites. Patients were treated with vaginal EBT alone or in combination with external beam radiation. The prescribed doses of EBT were successfully delivered in all 15 patients. From the first fraction through 3 months follow-up, there were 4 CTC Grade 1 adverse events and 2 CTC Grade II adverse events reported that were EBT related. The mild events reported were dysuria, vaginal dryness, mucosal atrophy, and rectal bleeding. The moderate treatment related adverse events included dysuria, and vaginal pain. No Grade III or IV adverse events were reported. The EBT system performed well and was associated with limited acute toxicities. EBT shows acute results similar to HDR brachytherapy. Additional research is needed to further assess the clinical efficacy and safety of EBT in the treatment of endometrial cancer

  11. Management of Renal Artery Stenosis - an Update

    Directory of Open Access Journals (Sweden)

    Alhadad A

    2008-01-01

    Full Text Available The role of the renal vasculature in eliciting renovascular hypertension (RVH was established in 1934, when Goldblatt et al. [1] in a classical experimental study demonstrated that partial obstruction of the renal artery increased mean arterial blood pressure (BP. The pathophysiology of renal artery stenosis (RAS is incompletely understood but has been postulated to be related to increased afterload from neurohormonal activation and cytokine release [2].Atherosclerotic RAS (ARAS is increasingly diagnosed in the expanding elderly population, which also has a high prevalence of arterial hypertension. There is still considerable uncertainty concerning the optimal management of patients with RAS. Many hypertensive patients with RAS have co-existing essential hypertension and furthermore, it is often difficult to determine to what degree the RAS is responsible for the impairment of renal function. There are three possible treatment strategies: medical management, surgery, or percutaneous transluminal renal angioplasty (PTRA with or without stent implantation. The use of stents has improved the technical success rate of PTRA and also led to lower risk of restenosis, in particular for ostial RAS. PTRA with stenting has therefore replaced surgical revascularisation for most patients with RAS and has led to a lower threshold for intervention. The treatment of choice to control hypertension in fibromuscular dysplasia (FMD is generally accepted to be PTRA [3]. In ARAS, on the other hand, the benefits with PTRA are less clear [4] and the challenge to identify which patients are likely to benefit from revascularisation remains unknown.

  12. Radionuclide venticulography in the evaluation of Captopril-mediated decrease of regurgitation in aortic and mitral insufficiency. Pt. 1. Methods and hormonal response

    Energy Technology Data Exchange (ETDEWEB)

    Kropp, J.; Schmidt, H.; Knopp, R.; Biersack, H.J. (Bonn Univ. (Germany). Dept. of Nuclear Medicine); Heck, I. (Lukas Hospital, Altenkirchen (Germany). Dept. of Internal Medicine); Nitsch, J. (St.-Agnes Hospital, Bocholt (Germany). Dept. of Internal Medicine)

    Nineteen patients with valve insufficency (VI) were investigated by gated-radionuclide-ventriculography (RNVG) to evaluate regurgitation fraction (RF). Ten of these patients were evaluated with right- and left heart catheterization (LRHC). 16 patients without valvular disease were investigated by left ventricular cineventriculography (LVCV) and RNVG. RNVG-left ventricular enddiastolic volume (LVEDV) was determined by a count-based method (LVED{sub cb}) as well as by a geometrical method (LVEDV{sub g}). After administration of Captopril (C), levels of angiotensin I increased in patients with VI (from 233 to 864 pg/ml, p<0.001) while angiotensin II decreased (from 43 to 30 pg/ml, p<0.001). Correlation of LRHC-RF and RNVG-RF, LVCV-LVEDV and LVEDV{sub cb}, LVCV-LVEDV and LVEDV{sub g} was characterized by the following equations: y=0.78x+6.9r=0.89; y=1.0x+5.7,r=0.93; and y=0.5x+92,r=0.45, respectively. Indexterms: Valve insufficency - radionuclide ventriculography - Captopril - Afterload reduction - regurgitation volume. (orig.).

  13. New-Onset Myocarditis in an Immunocompetent Adult with Acute Metapneumovirus Infection.

    Science.gov (United States)

    Weinreich, Mark A; Jabbar, Ahmad Y; Malguria, Nagina; Haley, Robert W

    2015-01-01

    Introduction. A number of viruses have been implicated in viral myocarditis; however, there has been no previous report of human metapneumovirus (hMPV) causing this condition. Discovered in 2001, hMPV is typically associated with upper respiratory illness, mainly affecting children. Case Presentation. We report the case of a 25-year-old man with acute systolic heart failure from viral myocarditis secondary to the hMPV. The patient was initially admitted to the general medical ward but developed increasing oxygen requirements resulting in transfer to the cardiac intensive care unit. Cardiac magnetic resonance imaging was used to help confirm the diagnosis. He was treated with intravenous diuretics, and afterload and preload agents, and he was subsequently discharged home after seven days of hospitalization. Discussion. hMPV is typically a respiratory pathogen; however, it was associated with in myocarditis in our patient. Due to the recent ability to detect this virus, we may see more cases of this, particularly during peak months of infection. Conclusion. This is the first case description of myocarditis associated with hMPV infection.

  14. New-Onset Myocarditis in an Immunocompetent Adult with Acute Metapneumovirus Infection

    Directory of Open Access Journals (Sweden)

    Mark A. Weinreich

    2015-01-01

    Full Text Available Introduction. A number of viruses have been implicated in viral myocarditis; however, there has been no previous report of human metapneumovirus (hMPV causing this condition. Discovered in 2001, hMPV is typically associated with upper respiratory illness, mainly affecting children. Case Presentation. We report the case of a 25-year-old man with acute systolic heart failure from viral myocarditis secondary to the hMPV. The patient was initially admitted to the general medical ward but developed increasing oxygen requirements resulting in transfer to the cardiac intensive care unit. Cardiac magnetic resonance imaging was used to help confirm the diagnosis. He was treated with intravenous diuretics, and afterload and preload agents, and he was subsequently discharged home after seven days of hospitalization. Discussion. hMPV is typically a respiratory pathogen; however, it was associated with in myocarditis in our patient. Due to the recent ability to detect this virus, we may see more cases of this, particularly during peak months of infection. Conclusion. This is the first case description of myocarditis associated with hMPV infection.

  15. Transcutaneous electrical nerve stimulation (TENS) in angina pectoris.

    Science.gov (United States)

    Mannheimer, C; Carlsson, C A; Vedin, A; Wilhelmsson, C

    1986-09-01

    The aim of this study was to determine the efficacy of transcutaneous electrical nerve stimulation (TENS) in the treatment of chronic stable severe angina pectoris. In a short-term study the effect of TENS was studied in 10 male patients with angina pectoris (functional class III and IV). All patients had previously been stabilized on long-term maximal oral treatment. The effects of the treatment were measured by means of repeated bicycle ergometer tests. All patients had an increased working capacity (16-85%), decreased ST segment depression and reduced recovery time during TENS. No adverse effects were observed. A long-term study of TENS on similarly selected patients showed beneficial effects in terms of pain reduction, reduced frequency of anginal attacks, increased physical activity and increased working capacity during bicycle ergometer tests. An invasive study was carried out with respect to systemic and coronary hemodynamics and myocardial metabolism during pacing provoked myocardial ischemia in 13 patients. The results showed that TENS led to an increased tolerance to pacing, improved lactate metabolism, less pronounced ST segment depression. A drop in systolic blood pressure during TENS treatment at identical pacing rates indicated a decreased afterload. An increased coronary flow to ischemic areas in the myocardium was supported by the fact that the rate pressure product during anginal pain increased during TENS.

  16. Use of paravascular admittance waveforms to monitor relative change in arterial blood pressure

    Science.gov (United States)

    Zielinski, Todd M.; Hettrick, Doug; Cho, Yong

    2010-04-01

    Non-invasive methods to monitor ambulatory blood pressure often have limitations that can affect measurement accuracy and patient adherence [1]. Minimally invasive measurement of a relative blood pressure surrogate with an implantable device may provide a useful chronic diagnostic and monitoring tool. We assessed a technique that uses electrocardiogram and paravascular admittance waveform morphology analysis to one, measure a time duration (vascular tone index, VTI in milliseconds) change from the electrocardiogram R-wave to admittance waveform peak and two, measure the admittance waveform minimum, maximum and magnitude as indicators of change in arterial compliance/distensibility or pulse pressure secondary to change in afterload. Methods: Five anesthetized domestic pigs (32 ± 4.2 kg) were used to study the effects of phenylephrine (1-5 ug/kg/min) on femoral artery pressure and admittance waveform morphology measured with a quadrapolar electrode array catheter placed next to the femoral artery to assess the relative change in arterial compliance due to change in peripheral vascular tone. Results: Statistical difference was observed (p blood pressure may be suitable for implantable devices to detect progression of cardiovascular disease such as hypertension.

  17. Nanotargeted Radionuclides for Cancer Nuclear Imaging and Internal Radiotherapy

    Directory of Open Access Journals (Sweden)

    Gann Ting

    2010-01-01

    Full Text Available Current progress in nanomedicine has exploited the possibility of designing tumor-targeted nanocarriers being able to deliver radionuclide payloads in a site or molecular selective manner to improve the efficacy and safety of cancer imaging and therapy. Radionuclides of auger electron-, α-, β-, and γ-radiation emitters have been surface-bioconjugated or after-loaded in nanoparticles to improve the efficacy and reduce the toxicity of cancer imaging and therapy in preclinical and clinical studies. This article provides a brief overview of current status of applications, advantages, problems, up-to-date research and development, and future prospects of nanotargeted radionuclides in cancer nuclear imaging and radiotherapy. Passive and active nanotargeting delivery of radionuclides with illustrating examples for tumor imaging and therapy are reviewed and summarized. Research on combing different modes of selective delivery of radionuclides through nanocarriers targeted delivery for tumor imaging and therapy offers the new possibility of large increases in cancer diagnostic efficacy and therapeutic index. However, further efforts and challenges in preclinical and clinical efficacy and toxicity studies are required to translate those advanced technologies to the clinical applications for cancer patients.

  18. Epidemiology of central sleep apnoea in heart failure.

    Science.gov (United States)

    Naughton, Matthew T

    2016-03-01

    Central sleep apnoea occurs in about a third of patients with reduced systolic heart failure and is a marker of increased mortality. Such patients usually are older males with advanced heart failure (i.e., high pulmonary wedge pressure), often in atrial fibrillation, with evidence of hyperventilation (i.e., low PaCO2) in the absence of hypoxemia. Characteristically, ventilation waxes and wanes in a sinusoidal pattern, with mild hypoxemia, occurring in the lighter levels of sleep usually when supine. Snoring may also occur in central sleep apnoea, often at the peak of hyperventilation, sometimes contributing to the confusion or overlap with obstructive sleep apnoea. Central sleep apnoea is associated with orthopnoea, paroxysmal nocturnal dyspnoea and an oscillatory respiratory pattern with an incremental cardiopulmonary exercise study. Importantly, heart failure therapies (e.g., afterload reduction, diuresis, pacemakers, transplantation) attenuate central sleep apnoea. Night to night variability in severity of central sleep apnoea may occur with changes in patients' posture during sleep (less severe when sleeping on-side or upright). PMID:26948168

  19. The role of SSDL-Helsinki for dosimetry and quality audit in radiotherapy

    International Nuclear Information System (INIS)

    Quality and dosimetry audit in radiotherapy has in Finland been implemented through inspections carried out by the Finnish Centre for Radiation and Nuclear Safety (STUK). In connection with the Radiation Metrology Laboratory of the Centre, the SSDL-Helsinki, there is a section for radiotherapy supervision. The inspection by STUK is an independent review of the quality and dosimetry control system which can be called quality and dosimetry audit by site visits. STUK is the responsible authority for the supervision of all use of radiation in Finland and that is why it also can set up requirements on the basis of results of the review. The disagreement of the measuring results between STUK and the radiotherapy department, of more than a given action level, will always lead to a thorough investigation of the reason and to a discussion of the most reliable results to be used for the treatments. The inspections include dose calibration for conventional X-ray therapy equipment and dose comparison, including field size dependence, for high energy equipment. For afterloading equipment the reference air kerma rate is checked. Additionally, the inspections by STUK include checks of the performance characteristics of the equipment and the accomplishment and the results of quality control procedures. Further, methods are currently being developed to supplement the direct measurements by TL-measurements in special phantoms in order to include the whole treatment chain (e.g. the treatment planning system) in the audit. (author). 7 refs, 1 tab

  20. Three-dimensional brachytherapy optimization techniques in the treatment of patients with cervix cancer; Apport des techniques de curietherapie optimisee grace a l'imagerie tridimensionnelle dans la prise en charge des patientes atteintes d'un cancer du col uterin

    Energy Technology Data Exchange (ETDEWEB)

    Haie-Meder, C.; Mazeron, R.; Verezesan, O.; Monnier, L.; Vieillot, S. [Institut Gustave-Roussy, Service de Curietherapie, 94 - Villejuif (France); Dumas, I. [Institut Gustave-Roussy, Service de Physique, 94 - Villejuif (France); Lhomme, C. [Institut Gustave-Roussy, Service d' Ooncologie Gynecologique, 94 - Villejuif (France); Morice, P. [Institut Gustave-Roussy, Service de Chirurgie Oncologique, 94 - Villejuif (France); Barillot, I. [Centre Regional Universitaire de Cancerologie Henry-S.-Kaplan, Hopital Bretonneau, CHU de Tours, 37 - Tours (France); Universite Francois-Rabelais, 37 - Tours (France)

    2009-10-15

    Traditionally, prescription and treatment planning in intracavitary brachytherapy for cervix cancer have used either reference points (mainly points A and B) or reference isodoses (60 Gy according to ICRU recommendations) to report doses to the target volume. Doses to critical organs were reported at bladder and rectum ICRU points. This practice has been supported by a long-standing clinical experience that has yielded an acceptable therapeutic ratio. The recent development of imaging has contributed to the improvement in target and organs at risk knowledge. In 2005 and 2006, the European group of brachytherapy -European Society for therapeutic radiology and oncology (GEC-E.S.T.R.O.) recommendations publications on 3-D based image brachytherapy have defined the different volumes of interest. These recommendations have been validated with intercomparison delineation studies. With the concomitant development of remote after-loading projectors, provided with miniaturized sources, it is now possible to plan radiation doses by adjusting dwell positions and relative dwell time values. These procedures allow better coverage of the targets while sparing O.A.R.. The recent literature data evidence a significant improvement in local control with no increase in complications. Further studies are needed to better define the dose recommended in both tumour and organs at risk. This is one of the goals of the European study on MRI-guided brachytherapy in locally advanced cervical cancer (E.M.B.R.A.C.E.) protocol (meaning of acronym: an international study on MRI-guided brachytherapy in locally advanced cervical cancer). (authors)

  1. Classification of Aortic Stenosis by Flow and Gradient Patterns Provides Insights into the Pathophysiology of Disease.

    Science.gov (United States)

    Bhattacharyya, Sanjeev; Mittal, Tarun; Abayalingam, Mayavan; Kabir, Tito; Dalby, Miles; Cleland, John G; Baltabaeva, Aigul; Rahman Haley, Shelley

    2016-08-01

    Different patterns of flow and valve gradients can lead to diagnostic uncertainty about the severity of aortic stenosis (AS). Consecutive patients with severe AS (valve area <1 cm(2)) underwent echocardiography and computed tomography. Patients were classified into 4 groups (high-gradient/normal flow [HGNF], high-gradient/low flow [HGLF], low-gradient/normal flow [LGNF], and low-gradient/low flow [LGLF]). Low flow was defined as stroke volume index <35 mL/m(2) and low gradient as a mean aortic gradient <40 mm Hg. Aortic valve calcification (AVC) was calculated using the Agatston score. Of 181 patients, 56, 30, 46, and 49 had HGNF, HGLF, LGNF and LGLF with median AVC of 2048, 2015, 1366, and 1178 AU/m(2) (P < .0001) and valvuloarterial impedance of 4.5, 6.4, 4.2, and 5.9, respectively (P < .0001). Among those with LGLF, AVC was lower in patients with preserved compared to reduced left ventricular ejection fraction (1018 vs 2550 AU/m(2); P < .0001), but valvuloarterial impedance was similar (P = .33). The LGLF AS with preserved ejection fraction is associated with lower AVC and may identify patients with less severe AS in association with an adaptive ventricular response to high afterload. PMID:26475710

  2. Validation of a decision-making strategy for systolic anterior motion following mitral valve repair

    Directory of Open Access Journals (Sweden)

    Landoni Giovanni

    2011-01-01

    Full Text Available Low cardiac output syndrome and hypotension are dreadful consequences of systolic anterior motion (SAM after a mitral valve (MV repair. The management of SAM in the operating room remains controversial. We validate a recently suggested two-step management method and classification of this complication. This was a teaching hospital-based observational study. We validated a novel two-step conservative management method, consisting in intravascular volume expansion and discontinuation of inotropic drugs (step 1, and increasing the afterload by ascending aorta manual compression while administering esmolol e.v. (step 2. We also validate a novel classification of SAM: easy-to-revert (responding to step 1, difficult-to-revert (responding to step 2, or persistent. Fifty patients had an easy-to-revert while 26 had a difficult-to-revert SAM; 4 patients had a persistent condition (promptly diagnosed through our decisional algorithm and underwent an immediate second pump run to repeat the mitral repair surgery. We confirmed that SAM after a repair of a degenerative MV is common and validated a simple two-step conservative management method that allows to clearly identify those few patients who require immediate surgical revision.

  3. In vivo and in vitro measurements of pulmonary arterial stiffness: A brief review.

    Science.gov (United States)

    Tian, Lian; Chesler, Naomi C

    2012-10-01

    During the progression of pulmonary hypertension (PH), proximal pulmonary arteries (PAs) undergo remodeling such that they become thicker and the elastic modulus increases. Both of these changes increase the vascular stiffness. The increase in pulmonary vascular stiffness contributes to increased right ventricular (RV) afterload, which causes RV hypertrophy and eventually failure. Studies have found that proximal PA stiffness or its inverse, compliance, is strongly related to morbidity and mortality in patients with PH. Therefore, accurate in vivo measurement of PA stiffness is useful for prognoses in patients with PH. It is also important to understand the structural changes in PAs that occur with PH that are responsible for stiffening. Here, we briefly review the most common parameters used to quantify stiffness and in vivo and in vitro methods for measuring PA stiffness in human and animal models. For in vivo approaches, we review invasive and noninvasive approaches that are based on measurements of pressure and inner or outer diameter or cross-sectional area. For in vitro techniques, we review several different testing methods that mimic one, two or several aspects of physiological loading (e.g., uniaxial and biaxial testing, dynamic inflation-force testing). Many in vivo and in vitro measurement methods exist in the literature, and it is important to carefully choose an appropriate method to measure PA stiffness accurately. Therefore, advantages and disadvantages of each approach are discussed. PMID:23372936

  4. Axial and centrifugal continuous-flow rotary pumps: a translation from pump mechanics to clinical practice.

    Science.gov (United States)

    Moazami, Nader; Fukamachi, Kiyotaka; Kobayashi, Mariko; Smedira, Nicholas G; Hoercher, Katherine J; Massiello, Alex; Lee, Sangjin; Horvath, David J; Starling, Randall C

    2013-01-01

    The recent success of continuous-flow circulatory support devices has led to the growing acceptance of these devices as a viable therapeutic option for end-stage heart failure patients who are not responsive to current pharmacologic and electrophysiologic therapies. This article defines and clarifies the major classification of these pumps as axial or centrifugal continuous-flow devices by discussing the difference in their inherent mechanics and describing how these features translate clinically to pump selection and patient management issues. Axial vs centrifugal pump and bearing design, theory of operation, hydrodynamic performance, and current vs flow relationships are discussed. A review of axial vs centrifugal physiology, pre-load and after-load sensitivity, flow pulsatility, and issues related to automatic physiologic control and suction prevention algorithms is offered. Reliability and biocompatibility of the two types of pumps are reviewed from the perspectives of mechanical wear, implant life, hemolysis, and pump deposition. Finally, a glimpse into the future of continuous-flow technologies is presented.

  5. Right Ventricular Adaptation Is Associated with the Glu298Asp Variant of the NOS3 Gene in Elite Athletes.

    Science.gov (United States)

    Szelid, Zsolt; Lux, Árpád; Kolossváry, Márton; Tóth, Attila; Vágó, Hajnalka; Lendvai, Zsuzsanna; Kiss, Loretta; Maurovich-Horvat, Pál; Bagyura, Zsolt; Merkely, Béla

    2015-01-01

    Nitric oxide (NO), an important endogenous pulmonary vasodilator is synthetized by the endothelial NO synthase (NOS3). Reduced NO bioavailability and thus the Glu298Asp polymorphism of NOS3 may enhance right ventricular (RV) afterload and hypertrophic remodeling and influence athletic performance. To test this hypothesis world class level athletes (water polo players, kayakers, canoeists, rowers, swimmers, n = 126) with a VO2 maximum greater than 50ml/kg/min were compared with non-athletic volunteers (n = 155). Cardiopulmonary exercise tests and cardiac magnetic resonance imaging (cMRI) were performed to determine structural or functional changes. Genotype distribution of the NOS3 Glu298Asp polymorphism was not affected by gender or physical performance. Cardiac MRI showed increased stroke volume with eccentric hypertrophy in all athletes regardless of their genotype. However, the Asp allelic variant carriers had increased RV mass index (32±6g versus 27±6g, ppolymorphism and RV structure and dimension in elite athletes emphasizes the importance of NOS3 gene function and NO bioavailability in sport related cardiac adaptation. PMID:26517550

  6. Newly developed ventricular assist device with linear oscillatory actuator.

    Science.gov (United States)

    Fukunaga, Kazuyoshi; Funakubo, Akio; Fukui, Yasuhiro

    2003-01-01

    The goal of this study was to develop a new direct electromagnetic left ventricular assist device (DEM-LVAD) with a linear oscillatory actuator (LOA). The DEM-LVAD is a pulsatile pump with a pusher plate. The pusher plate is driven directly by the mover of the LOA. The LOA provides reciprocating motion without using any movement converter such as a roller screw or a hydraulic system. It consists of a stator with a single winding excitation coil and a mover with two permanent magnets. The simple structure of the LOA is based on fewer parts to bring about high reliability and smaller size. The mover moves back and forth when forward and backward electric current is supplied to the excitation coil. The pump housings have been designed using three-dimensional computer aided design software and fabricated with the aid of computer aided manufacturing technology. Monostrut valves (Bjork-Shiley #21) were used for the prototype. The DEM-LVAD dimension is 96 mm in diameter and 50 mm thick with a mass of 0.62 kg and a volume of 280 ml. An in vitro test (afterload 100 mm Hg; preload 10 mm Hg; input power 10 W) demonstrated more than 6 L/minute maximum output and 15% maximum efficiency at 130 beats per minute (bpm). Dynamic stroke volume ranged between 40 and 60 ml. The feasibility of the DEM-LVAD was confirmed. PMID:12790386

  7. [Risk factors of late complications after interstitial 192Ir brachytherapy in cancers of the oral cavity].

    Science.gov (United States)

    Peiffert, D

    1997-01-01

    Brachytherapy has confirmed its prevailing role in conservative treatment of oral cavity carcinomas. To describe late toxicity in long-term surviving patients, comparisons with other series are necessary. Study of series of patients implanted for floor of the mouth or mobile tongue shows the need for more detailed data. Dental prophylaxy and lead protection of the mandibule, good indications and techniques of brachytherapy are necessary to avoid late complications. Some treatment factors have proved to be of good prognosis for late complications through multivariate analysis of large series treated with lr 192 wires, using the Paris system, eg, dose rate lower than 0.5 or 0.7 Gy/h, intersource spacing smaller than 1.2 or 1.5 cm, treated surface less than 12 cm2, lineic activity less than 1.5 mCi/cm, less than 1 cm diameter hyperdose, and use of mandibular lead protections. Tumor volume and location to the floor of mouth lead to higher risk of complications. Knowledge of treatment-related factors is important, with the development of new afterloading projectors allowing to control the dose rate and correct small inhomogeneities. High-dose rate exclusive brachytherapy is not recommended. More precise and reproducible classification should be used to report complications in series leading to publications in the future, thus allowing to compare results, reduce complication rates and improve the quality of life.

  8. Cardiac performance correlates of relative heart ventricle mass in amphibians.

    Science.gov (United States)

    Kluthe, Gregory J; Hillman, Stanley S

    2013-08-01

    This study used an in situ heart preparation to analyze the power output and stroke work of spontaneously beating hearts of four anurans (Rhinella marina, Lithobates catesbeianus, Xenopus laevis, Pyxicephalus edulis) and three urodeles (Necturus maculosus, Ambystoma tigrinum, Amphiuma tridactylum) that span a representative range of relative ventricle mass (RVM) found in amphibians. Previous research has documented that RVM correlates with dehydration tolerance and maximal aerobic capacity in amphibians. The power output (mW g(-1) ventricle mass) and stroke work (mJ g(-1) ventricle muscle mass) were independent of RVM and were indistinguishable from previously published results for fish and reptiles. RVM was significantly correlated with maximum power output (P max, mW kg(-1) body mass), stroke volume, cardiac output, afterload pressure (P O) at P max, and preload pressure (P I) at P max. P I at P max and P O at P max also correlated very closely with each other. The increases in both P I and P O at maximal power outputs in large hearts suggest that concomitant increases in blood volume and/or increased modulation of vascular compliance either anatomically or via sympathetic tone on the venous vasculature would be necessary to achieve P max in vivo. Hypotheses for variation in RVM and its concomitant increased P max in amphibians are developed.

  9. CT-guided interstitial HDR brachytherapy for recurrent glioblastoma multiforme. Long-term results

    Energy Technology Data Exchange (ETDEWEB)

    Tselis, N.; Roeddiger, S.; Filipowicz, I.; Kontova, M.; Heyd, R.; Zamboglou, N. [Offenbach Hospital (Germany). Dept. of Radiotherapy and Interdisciplinary Oncology; Kolotas, C. [Offenbach Hospital (Germany). Dept. of Radiotherapy and Interdisciplinary Oncology; Hirslanden Medical Center, Aarau (Switzerland). Inst. of Radiotherapy; Birn, G. [Offenbach Hospital (Germany). Dept. of Neurosurgery; Fountzilas, G.; Selviaridis, P. [Aristotle Univ. of Thessaloniki School of Medicine, Thessaloniki (Greece); Baltas, D.; Anagnostopoulos, G. [Offenbach Hospital (Germany). Dept. of Medical Physics and Engineering

    2007-10-15

    Background and Purpose: Recurrences of glioblastoma multiforme (GBM) within previously irradiated volumes pose a serious therapeutic challenge. This retrospective study evaluates the long-term tumor control of recurrent GBM treated with interstitial high-dose-rate brachytherapy (HDR-BRT). Patients and Methods: Between 1995 and 2003, 84 patients were treated for recurrent cerebral GBM located within previously irradiated volumes. All patients had received adjuvant external radiotherapy following primary surgery, with a focal dose up to 60 Gy. The median recurrent tumor volume was 51 cm{sup 3} (3-207 cm{sup 3}), and the HDR-BRT consisted of an afterloading {sup 192}Ir implant which delivered a median dose of 40 Gy (30-50 Gy). Catheter implantation was implemented using interactive computed tomography (CT) guidance under local anesthesia and sedoanalgesia. Results: After a median follow-up of 61 months, 5/84 patients (6%) were alive. The median post-BRT survival was 37 weeks, and the median overall survival 78 weeks. Moderate to severe complications occurred in 5/84 cases (6%). Conclusion: For patients with recurrences of GBM within previously irradiated volumes, CT-guided interstitial HDR-BRT is a feasible treatment option that can play an important role in providing palliation. (orig.)

  10. Treatment results of stereotactic interstitial brachytherapy for primary and metastatic brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, G.L.; Luxton, G.; Cohen, D.; Petrovich, Z.; Langholz, B.; Apuzzo, M.L.; Sapozink, M.D. (USC School of Medicine, Los Angeles, CA (USA))

    1991-08-01

    A total of 41 stereotactic interstitial brain implants in 39 patients were performed for recurrence after teletherapy (recurrence implant), or as part of initial treatment in conjunction with teletherapy (primary implant). Implanted tumors consisted of malignant gliomas (33), other primary brain tumors (3), and single metastatic lesions (3). All patients were temporarily implanted with Ir-192 using a coaxial catheter afterloading system; two patients were implanted twice. Survival post-implant for glioblastoma multiforme (GBM), 13 patients, was 10 months whether implanted primarily or for recurrence. Mean time to recurrence, measured from initiation of teletherapy to implantation, was 10 months. Twenty patients with anaplastic astrocytoma (AA) had a median survival post-implant of 23 months for primary implants (7 patients) and 11 months for recurrence implants (13 patients). Mean time to recurrence, measured from initiation of teletherapy to implantation, was 19 months. Three patients (9%) of the evaluable group required reoperation for symptomatic mass effect, all with initial diagnosis of AA. Survival for this subgroup was 14, 22, and 32 months post-implantation. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically feasible with negligible acute morbidity and mortality, and appeared to offer limited prolongation of control for a subset of patients with recurrent malignant gliomas. The role of this modality in primary treatment for malignant gliomas needs to be further defined by prospectively randomized trials.

  11. Oxidative and nitrosative signalling in pulmonary arterial hypertension - Implications for development of novel therapies.

    Science.gov (United States)

    Hansen, Thomas; Galougahi, Keyvan-Karimi; Celermajer, David; Rasko, Nathalie; Tang, Owen; Bubb, Kristen J; Figtree, Gemma

    2016-09-01

    Pulmonary arterial hypertension (PAH) is a syndrome characterised by an increase in pulmonary vascular resistance. This results in elevated resting pulmonary artery pressure and leads to progressive right ventricular (RV) failure, secondary to increased afterload. Although initially thought to be a disease driven primarily by endothelial dysfunction with a resultant vasoconstrictor versus vasodilator imbalance, it has become increasingly apparent that the rise in pulmonary vascular resistance that causes RV failure is also attributable to pulmonary vascular remodelling. This inflammatory, hyper-proliferative and anti-apoptotic phenotype is accompanied by a metabolic switch from physiological mitochondrial oxidative phosphorylation to aerobic glycolysis. The molecular pathways triggering this cellular metabolic shift have been the subject of extensive investigation, as their discovery will inevitably lead to new therapeutic targets. Reactive oxygen/nitrogen species (ROS/RNS) including hydrogen peroxide, superoxide and peroxynitrite are second messenger molecules that are involved in functional oxidative and nitrosative modification of proteins. Dysregulation of oxidative signalling caused by an excess of ROS and RNS relative to antioxidants has been heavily implicated in the underlying pathophysiology of PAH and likely participates in this metabolic reprogramming. This review will focus on the role of oxidative signalling and redox reactions to the molecular pathology of PAH. In addition, promising novel therapeutic agents targeting these pathways will be discussed.

  12. 肥厚型梗阻性心肌病患者行髋关节置换术的麻醉处理%Anesthetic management of a patient with hypertrophic obstructive cardiomyopathy for hip joint replacement Introduction

    Institute of Scientific and Technical Information of China (English)

    刘秀芬; 王东信

    2011-01-01

    IntroductionHypertrophic cardiomyopathy(HCM)is not an uncommon cardiac disease now,it was reported that the prevalence of HCM is 0.18%in Chinese at present[ 1].Hypertrophic obstructive carchomyopathy(HOCM)is a subset of HCM with left ventricular outilow tract(LVOT)obstruction.Majority of case repofls have focused on anesthetic management of HOCM in children and parturients,eithercombined spinal and epidural(CSE)or general anesthesia selected.%@@ Hypertrophic cardiomyopathy (HCM) is not an uncommon cardiac disease now,it was reported that the prevalence of HCM is 0.18% in Chinese at present .Hypertrophic obstructive cardiomyopathy ( HOCM) is a subset of HCM with left ventricular outflow tract ( LVOT) obstruction.Majority of case reports have focused on anesthetic management of HOCM in children and parturients, either combined spinal and epidural (CSE) or general anesthesia selected.But there were existing debates about anesthetic methods used, some authors regarded spinal or epidural anesthesia as contraindicated for the sake of lowering afterload, some authors believed that the serious problems could occur during general anesthesia.

  13. A hyperkinetic heart in uncomplicated active acromegaly. Explanation of hypertension in acromegalic patients?

    Science.gov (United States)

    Thuesen, L; Christensen, S E; Weeke, J; Orskov, H; Henningsen, P

    1988-01-01

    Cardiac function was studied by echocardiography in 12 patients with active acromegaly and in 12 age- and sex-matched healthy control subjects. None of the patients had cardiovascular diseases or other endocrine diseases than acromegaly. The patients had a mean age of 39 +/- 5 years and were short-term acromegalic with a mean duration of disease of 6 +/- 3 years. Mean left ventricular mass was 163 +/- 43 g/m2 in the acromegalic group versus 120 +/- 24 g/m2 in the control group. Preload (the diastolic diameter of the left ventricle) was within normal limits, while afterload (end-systolic meridional wall stress) was significantly decreased in the acromegalic group. Myocardial contractility assessed as fractional shortening of the left ventricle was 39.9 +/- 3.6% in the acromegalic group versus 32.9 +/- 5.1% in the control group, and cardiac output was increased by 52% in the acromegalic group because of increased heart rate and stroke volume. We suggest that augmented peripheral blood flow is responsible for the condition of cardiac hyperkinesia in short-term acromegaly and involved in the development of hypertension, which is a frequent complication of long-term acromegaly.

  14. Intraluminal brachytherapy with metallic stenting in the palliative treatment of malignant obstruction of the bile duct

    International Nuclear Information System (INIS)

    The purpose of this study was to describe the outcome of intraluminal high-dose-rate (HDR) brachytherapy with metallic stenting in patients with obstructing extrahepatic cholangiocarcinoma. Eight patients with inoperable and/or unresectable extrahepatic bile duct carcinomas were treated with intraluminal brachytherapy (ILBT) followed by self-expandable metallic stent placement. Following percutaneous transhepatic drainage, ILBT was delivered by an HDR-Ir-192 source using the Micro-Selectron afterloading device. Two treatments were planned one week apart, with each treatment consisting of a single 10 Gy fraction. Biliary patency and palliative effect were assessed by serial labs (including bilirubin/alkaline phosphatase), symptomatic improvement, and/or cholangiography. All eight patients tolerated the first application of ILBT well, and five of them completed two-intraluminal treatments. Six of eight had satisfactory control of jaundice until death. Pain relief was observed in four of five (80%) and pruritis in six of seven (86%) patients experiencing such symptoms. The mean and median times of stent patency were 6.9 and 5 months (range, 4-14), respectively. Gastrointestinal bleeding and/or cholangitis occurred in three patients. HDR ILBT with metallic stenting for patients with obstructive jaundice from extrahepatic bile duct carcinoma appears to be feasible and associated with acceptable toxicity. These treatments may lead to an improved quality of life in these patients. (author)

  15. Fiber-coupled radioluminescence dosimetry with saturated Al2O3:C crystals: Characterization in 6 and 18 MV photon beams

    DEFF Research Database (Denmark)

    Andersen, Claus Erik; Damkjær, Sidsel Marie Skov; Kertzscher Schwencke, Gustavo Adolfo Vladimir;

    2011-01-01

    Radioluminescence (RL) and optically stimulated luminescence (OSL) from carbon-doped aluminum oxide crystals can be used for medical dosimetry in external beam radiotherapy and remotely afterloaded brachytherapy. The RL/OSL signals are guided from the treatment room to the readout instrumentation...... using optical fiber cables, and in vivo dosimetry can be carried out in real time while the dosimeter probes are in the patient. The present study proposes a new improved readout protocol based solely on the RL signal from Al2O3:C. The key elements in the protocol are that Al2O3:C is pre-dosed with 20...... ((−0.21 ± 0.01)%/ °C), and dose-delivery rate ((−0.22 ± 0.01)% per 100 MU/min). A temporal gating technique was used for separation of RL and stem signals (i.e. Cerenkov light and fluorescence induced in the optical fiber cable during irradiation). The new readout protocol was a substantial improvement...

  16. 不同加载形式高负荷低压涡轮的性能分析%Performance Analysis of High Loaded Low Pressure Turbine with Different Loading Distribution

    Institute of Scientific and Technical Information of China (English)

    白涛

    2016-01-01

    通过设计负荷能力相同而负荷分布形式不同的3种叶型来分析在宽广的雷诺数范围内负荷分布对涡轮叶型边界层发展的影响规律。研究结果表明:后加载叶型对雷诺数的变化较为敏感,尤其是在低雷诺数范围内,而前加载和均匀加载则相对不敏感。研究结果可为设计适用于不同工况的叶型提供理论指导。%The effect law of loading distribution on boundary layer development at wide range Reynolds number was studied through design three turbine blades with different load distribution but same load level.The research indicated that after-loaded airfoil is more sensitive to Reynolds number especially when at the low Reynolds numbers while the front and mid loaded airfoil is less sensitive. The research can provide theory guidance for the design of airfoil which worked at different work condition.

  17. Captopril-induced reduction of regurgitation fraction in aortic insufficiency: Acute and long-term effects

    Energy Technology Data Exchange (ETDEWEB)

    Kropp, J.; Heck, I.; Reske, S.N.; Biersack, H.J.; Mattern, H.; Winkler, C.; Polikl, M.

    1985-05-01

    In aortic insufficiency (AI) the inhibition of the stimulated Renin-Angiotensin-System (RAS) by Captopril (C) reduced afterload and leads consequently to a diminished regurgitation fraction (RF). In 17 patients (pts) with pure severe AI RF, left ventricular ejection fraction (LVEFE) and heart rate were determined before (1) and 1 hr after (2) administration of 25 mg of C.Long term dosis was 3 x 25 mg of C and follow up time was 3-11 months (medium:6). The values were determined by gated radionuclide ventriculography using red blood cells labeled in vivo with 15 mCi Tc-99mROI's were selected over both ventricles in enddiastolic and endsystolic frames. Ventricular boundaries were defined by a fourier phase image overlay. RF was calculated by the background corrected count rate ratio of left and right ventricular ROI. Systolic and diastolic blood pressure (BPs,BPd), plasma levels of angiotensin I,II(A1,A2) and the activity of angiotensin converting enzyme (ACE) were determined before and 1 hr after C administration. After C there is a decrease in RF which persists in the long term follow period in up to to now 8 pts. The authors conclude: inhibition of ACE reduces significantly aortic regurgitation in patients with AI and has thus a beneficial effect on left ventricular performance. This effect persists in long term treatment and therefore seems beneficial to delay the point of operation.

  18. Use of a covered stent modification to produce a transcatheter valve: laboratory and animal testing.

    Science.gov (United States)

    Levi, Daniel S; Raff, Evan; Stepan, Lenka; Liu, Jasen; Williams, Ryan J; Moore, John W; Carman, Greg

    2005-01-01

    Stent-based transcatheter valves continue to require large sheaths inappropriate for deployment in children. Low-profile covered stent valves (CSVs) were constructed by removing triangular sections from two sides of partially expanded Palmaz P308 stents before covering the stents with 0.1 mm polytetrafluoroethylene. Valves were carefully crimped onto balloon catheters and deployed in a pulsatile flow loop. With fixed afterload and pump output, flow, degree of stenosis, effect on pulse pressure, and ease of deployment were determined for each valve. In vivo transcatheter feasibility studies were then performed by disabling the aortic valve of two 25-kg pigs, and deploying transcatheter CSVs into their descending aorta. All transcatheter valves deployed consistently via sheaths three French sizes larger than the recommended sheath for their balloon and none created significant obstruction. With the bicuspid and supravalvar CSVs, the flow was 64% and 79% (respectively) of a commercially available valve. Angiograms revealed excellent acute CSV function after deployment with only mild regurgitation and without significant obstruction to systolic flow. Although long-term testing is required, a modified CSV design may have utility in low-profile pediatric transcatheter valve replacement. PMID:16340356

  19. An isolated working heart system for large animal models.

    Science.gov (United States)

    Schechter, Matthew A; Southerland, Kevin W; Feger, Bryan J; Linder, Dean; Ali, Ayyaz A; Njoroge, Linda; Milano, Carmelo A; Bowles, Dawn E

    2014-01-01

    Since its introduction in the late 19(th) century, the Langendorff isolated heart perfusion apparatus, and the subsequent development of the working heart model, have been invaluable tools for studying cardiovascular function and disease(1-15). Although the Langendorff heart preparation can be used for any mammalian heart, most studies involving this apparatus use small animal models (e.g., mouse, rat, and rabbit) due to the increased complexity of systems for larger mammals(1,3,11). One major difficulty is ensuring a constant coronary perfusion pressure over a range of different heart sizes - a key component of any experiment utilizing this device(1,11). By replacing the classic hydrostatic afterload column with a centrifugal pump, the Langendorff working heart apparatus described below allows for easy adjustment and tight regulation of perfusion pressures, meaning the same set-up can be used for various species or heart sizes. Furthermore, this configuration can also seamlessly switch between constant pressure or constant flow during reperfusion, depending on the user's preferences. The open nature of this setup, despite making temperature regulation more difficult than other designs, allows for easy collection of effluent and ventricular pressure-volume data. PMID:24962492

  20. Results of radiation therapy for carcinoma of the uterine cervix

    International Nuclear Information System (INIS)

    Fifty-nine consecutive patients who were treated with radiation therapy for carcinoma of the uterine cervix between April 1982 and December 1986 were reviewed. Twelve patients were treated with low dose-rate intracavitary irradiation using radium-226, and 46 were treated with high dose-rate irradiation using a remote afterloading system combined with external irradiation, and the other one was treated with external irradiation alone. The 5-year-survival rates for stage Ib, IIa, IIb, IIIb, and IVa were 77.8, 85.7, 87.5, 45.5 and 40.0%, respectively. The 5-year-survival rates for the low and high dose-rates irradiation were 66.7 and 73.9%, respectively. The most common complication of radiation therapy was rectal bleeding, which required conservative treatment (grade 2) in 11 (18.6%). The morbidities for the low and high dose-rates irradiation were similar. The causes of death in 17 patients were local recurrence in 14, metastases in 2 and other specified in one. These findings suggest that high dose-rate intracavitary irradiation is as effective as low dose-rate irradiation for carcinoma of the uterine cervix, and that further efforts for controlling the local tumors with stage IIIb disease without an increased rate of side-effects is required. (author)

  1. Current Brachytherapy Quality Assurance Guidance: Does It Meet the Challenges of Emerging Image-Guided Technologies?

    International Nuclear Information System (INIS)

    In the past decade, brachytherapy has shifted from the traditional surgical paradigm to more modern three-dimensional image-based planning and delivery approaches. The role of intraoperative and multimodality image-based planning is growing. Published American Association of Physicists in Medicine, American College of Radiology, European Society for Therapeutic Radiology and Oncology, and International Atomic Energy Agency quality assurance (QA) guidelines largely emphasize the QA of planning and delivery devices rather than processes. These protocols have been designed to verify compliance with major performance specifications and are not risk based. With some exceptions, complete and clinically practical guidance exists for sources, QA instrumentation, non-image-based planning systems, applicators, remote afterloading systems, dosimetry, and calibration. Updated guidance is needed for intraoperative imaging systems and image-based planning systems. For non-image-based brachytherapy, the American Association of Physicists in Medicine Task Group reports 56 and 59 provide reasonable guidance on procedure-specific process flow and QA. However, improved guidance is needed even for established procedures such as ultrasound-guided prostate implants. Adaptive replanning in brachytherapy faces unsolved problems similar to that of image-guided adaptive external beam radiotherapy

  2. Tolvaptan and its potential in the treatment of hyponatremia

    Directory of Open Access Journals (Sweden)

    Y Howard Lien

    2008-10-01

    Full Text Available Megan B Dixon, Y Howard LienDepartment of Medicine, University of Arizona, Arizona Kidney Disease and Hypertension Center, Tucson, Arizona, USAAbstract: Tolvaptan is a selective arginine vasopressin (AVP V2 receptor blocker used to induce free water diuresis in the treatment of euvolemic or hypervolemic hyponatremia. Currently the orally active medication is in the final stages prior to approval by the FDA for outpatient therapy. It appears to be safe and effective at promoting aquaresis and raising serum sodium levels in both short- and long-term studies. Tolvaptan is also effective for treatment of congestive heart failure (CHF exacerbation, but whether there are long standing beneficial effects on CHF is still controversial. Prolonged use of tolvaptan leads to increased endogenous levels of AVP and perhaps over-stimulation of V1A receptors. Theoretically this activation could lead to increased afterload and cardiac myocyte fibrosis, causing progression of CHF. However, after 52 weeks of tolvaptan therapy there was no worsening of left ventricular dilatation. In addition, tolvaptan is metabolized by the CYP3A4 system; thus physicians should be aware of the potential for increased interactions with other medications. Tolvaptan is a breakthrough in the therapy of hyponatremia as it directly combats elevated AVP levels associated with the syndrome of inappropriate secretion of antidiuretic hormone, congestive heart failure, and cirrhosis of the liver.Keywords: hyponatremia, arginine vasopressin, vasopressin receptors, syndrome of inappropriate antidiuretic hormone, congestive heart failure, liver cirrhosis

  3. Real-Time Assessment of Autonomic Nerve Activity During Adaptive Servo-Ventilation Support or Waon Therapy.

    Science.gov (United States)

    Imamura, Teruhiko; Kinugawa, Koichiro; Nitta, Daisuke; Komuro, Issei

    2016-07-27

    Adaptive servo-ventilation support and Waon therapy are recently developed non-pharmacological and noninvasive therapies for patients with heart failure refractory to guideline-directed medical therapy. These therapies decrease both preload and afterload, increase cardiac output, and appear to ameliorate autonomic nerve activity. However, the time course of autonomic nerve activity during these therapies remains unclear. We performed heart rate variability analysis using the MemCalc power spectral density method (MemCalc system; Suwa Trust Co, Tokyo) to assess autonomic nerve activity during adaptive servo-ventilation support and Waon therapy in two different cases and determined the time course of autonomic nerve activity during these therapies. During both therapies, we found a drastic increase in parasympathetic nerve activity and continuous suppression of sympathetic nerve activity. Heart rate variability analysis using the MemCalc method may be promising for the assessment of the efficacy of various treatments, including adaptive servo-ventilation support and Waon therapy, from the viewpoint of autonomic nerve activity. PMID:27385607

  4. [Cirrhotic cardiomyopathy: a specific entity].

    Science.gov (United States)

    Brondex, A; Arlès, F; Lipovac, A-S; Richecoeur, M; Bronstein, J-A

    2012-04-01

    Cirrhosis is a frequent and severe condition, which is the late stage of numerous chronic liver diseases. It is associated with major hemodynamic alterations characteristic of hyperdynamic circulation and with a series of structural, functional, electrophysiological and biological heart abnormalities termed cirrhotic cardiomyopathy. The pathogenesis of this syndrome is multifactorial. It is usually clinically latent or mild, likely because the peripheral vasodilatation significantly reduces the left ventricle afterload. However, sudden changes of hemodynamic state (vascular filling, surgical or transjugular intrahepatic porto-systemic shunts, peritoneo-venous shunts and orthotopic liver transplantation) or myocardial contractility (introduction of beta-blocker therapy) can unmask its presence, and sometimes convert latent to overt heart failure. Cirrhotic cardiomyopathy may also contribute to the pathogenesis of hepatorenal syndrome. This entity has been described recently, and its diagnostic criteria are still under debate. To date, current management recommendations are empirical, nonspecific measures. Recognition of cirrhotic cardiomyopathy depends on a high level of awareness for the presence of this syndrome, particularly in patients with advanced cirrhosis who undergo significant surgical, pharmacological or physiological stresses. PMID:22115174

  5. Cirrhotic cardiomyopathy.

    Science.gov (United States)

    Milani, A; Zaccaria, R; Bombardieri, G; Gasbarrini, A; Pola, P

    2007-06-01

    Decompensated liver cirrhosis is characterized by a peripheral vasodilation with a low-resistance hyperdynamic circulation. The sustained increase of cardiac work load associated with such a condition may result in an inconstant and often subclinical series of heart abnormalities, constituting a new clinical entity known as "cirrhotic cardiomyopathy". Cirrhotic cardiomyopathy is variably associated with baseline increase in cardiac output, defective myocardial contractility and lowered systo-diastolic response to inotropic and chronotropic stimuli, down-regulated beta-adrenergic function, slight histo-morphological changes, and impaired electric "recovery" ability of ventricular myocardium. Cirrhotic cardiomyopathy is usually clinically latent or mild, likely because the peripheral vasodilation significantly reduces the left ventricle after-load, thus actually "auto-treating" the patient and masking any severe manifestation of heart failure. In cirrhotic patients, the presence of cirrhotic cardiomyopathy may become unmasked and clinically evident by certain treatment interventions that increase the effective blood volume and cardiac pre-load, including surgical or transjugular intrahepatic porto-systemic shunts, peritoneo-venous shunts (LeVeen) and orthotopic liver transplantation. Under these circumstances, an often transient overt congestive heart failure may develop, with increased cardiac output as well as right atrial, pulmonary artery and capillary wedge pressures. PMID:17383244

  6. Acute hypertensive crisis in pregnancy.

    Science.gov (United States)

    Silver, H M

    1989-05-01

    Severe pre-eclampsia is a state of acute afterload increase where compensation may be total by use of the Frank-Starling mechanism and/or increased adrenergic drive, or may be uncompensated in a patient with limited or exhausted preload reserve. As such, we are presented with a diverse group of patients and antihypertensive therapy ideally should be individualized. In reality we are dealing with a complex situation because of the presence of the fetus raising concerns about direct effects on the fetus as well as on uteroplacental blood flow. This limits our choice of agents to those with extensive use in pregnancy except in complicated or resistant cases. For these reasons, hydralazine is the antihypertensive agent of choice for treatment of acute hypertensive emergencies in pregnancy. In the complicated case other agents such as sodium nitroprusside or nitroglycerin may be more appropriate and, in these cases, hemodynamic monitoring should be performed to allow not only greater safety, but also to tailor therapy to the individual hemodynamic profile. PMID:2649760

  7. Multiple-site perineal applicator (MUPIT) for treatment of prostatic, anorectal, and gynecologic malignancies

    International Nuclear Information System (INIS)

    Recently, transperineal interstitial-intracavitary applicators have been used to treat locally limited and advanced perineal and gynecologic malignancies. The authors have developed a single afterloading applicator, referred to as the ''MUPIT'' (Martinez Universal Perineal Interstitial Template), which with its prototypes has been utilized to treat 78 patients with malignancies of the cervix, vagina, female urethra, perineum, prostate, and anorectal region. The device basically consists of two acrylic cylinders, an acrylic template with a predrilled array of holes that serve as guides for trocars, and a cover plate. Some of the guide holes on the template are angled outward to permit a wide lateral coverage without danger of striking the ischium. The cylinders have an axial hole large enough to pass a central tandem or a suction tube for the drainage of secretions. Thus, the device allows for the interstitial placement of 192Ir ribbons as well as the intracavitary placement of either 137Cs tubes or 192Ir ribbons. In use, the cylinders are placed in the vagina and rectum and then fastened to the template, so that a fixed geometric relationship among the tumor volume, normal structures, and source placement is preserved throughout the course of the implantation. Appropriate computer programs also have been developed on a minicomputer for the corresponding dose-rate computations

  8. Multiple-site perineal applicator (MUPIT) for treatment of prostatic, anorectal, and gynecologic malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, A.; Cox, R.S.; Edmundson, G.K.

    1984-02-01

    Recently, transperineal interstitial-intracavitary applicators have been used to treat locally limited and advanced perineal and gynecologic malignancies. The authors have developed a single afterloading applicator, referred to as the ''MUPIT'' (Martinez Universal Perineal Interstitial Template), which with its prototypes has been utilized to treat 78 patients with malignancies of the cervix, vagina, female urethra, perineum, prostate, and anorectal region. The device basically consists of two acrylic cylinders, an acrylic template with a predrilled array of holes that serve as guides for trocars, and a cover plate. Some of the guide holes on the template are angled outward to permit a wide lateral coverage without danger of striking the ischium. The cylinders have an axial hole large enough to pass a central tandem or a suction tube for the drainage of secretions. Thus, the device allows for the interstitial placement of /sup 192/Ir ribbons as well as the intracavitary placement of either /sup 137/Cs tubes or /sup 192/Ir ribbons. In use, the cylinders are placed in the vagina and rectum and then fastened to the template, so that a fixed geometric relationship among the tumor volume, normal structures, and source placement is preserved throughout the course of the implantation. Appropriate computer programs also have been developed on a minicomputer for the corresponding dose-rate computations.

  9. Doppler echocardiographic study in adolescents and young adults with sickle cell anemia

    Directory of Open Access Journals (Sweden)

    Wolney de Andrade Martins

    1999-12-01

    Full Text Available OBJECTIVE: Anatomical and functional assessment of the heart through Doppler and echocardiography in patients with cell anemia (SCA. METHODS: Twenty-five patients with SCA and ages ranging from 14 to 45 years were prospectively studied in a comparison with 25 healthy volunteers. All of them underwent clinical and laboratory evaluation and Doppler echocardiography as well.The measurements were converted into body surface indices. RESULTS: There were increases in all chamber diameters and left ventricle (LV mass of the SCA patients. It was characterised an eccentric hypertrophy of the left ventricle. The preload was increased (left ventricle end-diastolic volume and the afterload was decreased (diastolic blood pressure, peripheral vascular resistance and end-systolic parietal stress ESPS. The cardiac index was increased due to the stroke volume. The ejection fraction and the percentage of the systolic shortening , as well as the systolic time intervals of the LV were equivalent. The isovolumetric contraction period of the LV was increased. The mitral E-septum distance and the end-systolic volume index (ESVi were increased. The ESPS/ESVi ratio,a loading independent parameter, was decreased in SCA, suggesting systolic dysfunction. No significant differences in the diastolic function or in the pulmonary pressure occurred. CONCLUSION: Chamber dilations, eccentric hypertrophy and systolic dysfunction confirm the evidence of the literature in characterizing a sickle cell anemia cardiomyopathy.

  10. Pharmacotherapy update on the use of vasopressors and inotropes in the intensive care unit.

    Science.gov (United States)

    Jentzer, Jacob C; Coons, James C; Link, Christopher B; Schmidhofer, Mark

    2015-05-01

    This paper summarizes the pharmacologic properties of vasoactive medications used in the treatment of shock, including the inotropes and vasopressors. The clinical application of these therapies is discussed and recent studies describing their use and associated outcomes are also reported. Comprehension of hemodynamic principles and adrenergic and non-adrenergic receptor mechanisms are salient to the appropriate therapeutic utility of vasoactive medications for shock. Vasoactive medications can be classified based on their direct effects on vascular tone (vasoconstriction or vasodilation) and on the heart (presence or absence of positive inotropic effects). This classification highlights key similarities and differences with respect to pharmacology and hemodynamic effects. Vasopressors include pure vasoconstrictors (phenylephrine and vasopressin) and inoconstrictors (dopamine, norepinephrine, and epinephrine). Each of these medications acts as vasopressors to increase mean arterial pressure by augmenting vascular tone. Inotropes include inodilators (dobutamine and milrinone) and the aforementioned inoconstrictors. These medications act as inotropes by enhancing cardiac output through enhanced contractility. The inodilators also reduce afterload from systemic vasodilation. The relative hemodynamic effect of each agent varies depending on the dose administered, but is particularly apparent with dopamine. Recent large-scale clinical trials have evaluated vasopressors and determined that norepinephrine may be preferred as a first-line therapy for a broad range of shock states, most notably septic shock. Consequently, careful selection of vasoactive medications based on desired pharmacologic effects that are matched to the patient's underlying pathophysiology of shock may optimize hemodynamics while reducing the potential for adverse effects. PMID:25432872

  11. Clinical outcome of high-dose-rate interstitial brachytherapy in patients with oral cavity cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Uk; Cho, Kwan Ho; Moon, Sung Ho; Choi, Sung Weon; Park, Joo Yong; Yun, Tak; Lee, Sang Hyun; Lim, Young Kyung; Jeong, Chi Young [National Cancer Center, Goyang (Korea, Republic of)

    2014-12-15

    To evaluate the clinical outcome of high-dose-rate (HDR) interstitial brachytherapy (IBT) in patients with oral cavity cancer. Sixteen patients with oral cavity cancer treated with HDR remote-control afterloading brachytherapy using 192Ir between 2001 and 2013 were analyzed retrospectively. Brachytherapy was administered in 11 patients as the primary treatment and in five patients as salvage treatment for recurrence after the initial surgery. In 12 patients, external beam radiotherapy (50-55 Gy/25 fractions) was combined with IBT of 21 Gy/7 fractions. In addition, IBT was administered as the sole treatment in three patients with a total dose of 50 Gy/10 fractions and as postoperative adjuvant treatment in one patient with a total of 35 Gy/7 fractions. The 5-year overall survival of the entire group was 70%. The actuarial local control rate after 3 years was 84%. All five recurrent cases after initial surgery were successfully salvaged using IBT +/- external beam radiotherapy. Two patients developed local recurrence at 3 and 5 months, respectively, after IBT. The acute complications were acceptable (< or =grade 2). Three patients developed major late complications, such as radio-osteonecrosis, in which one patient was treated by conservative therapy and two required surgical intervention. HDR IBT for oral cavity cancer was effective and acceptable in diverse clinical settings, such as in the cases of primary or salvage treatment.

  12. Hemodynamic changes in depressive patients

    Institute of Scientific and Technical Information of China (English)

    MA Ying; LI Hui-chun; ZHENG Lei-lei; YU Hua-liang

    2006-01-01

    Objective: This study is aimed at exploring the relationship between hemodynamic changes and depressive and anxious symptom in depression patients. Methods: The cardiac function indices including the left stroke index (LSI), ejection fraction (EF), heart rate (HR), diastolic pressure mean (DPM), systolic pressure mean (SPM), left ventricle end-diastolic volume (LVDV), effective circulating volume (ECV), resistance total mean (RTM) and blood flow smooth degree (BFSD) were determined in 65 patients with major depressive disorders and 31 healthy normal controls. The clinical symptoms were assessed with Hamilton depression scale (HAMD) and Hamilton anxiety scale (HAMA). Results: In patients with depression without anxiety,LSI, EF, LVDV, DPM, SPM, ECV, BFSD were significantly lower than those in controls, while RTM was higher than that in controls. Patients with comorbidity of depression and anxiety showed decreased LVDV, ECV, BFSD, and increased HR in comparison with the controls. The anxiety/somatization factor score positively correlated with LSI, EF, LVDV, but negatively correlated with RTM. There was negative correlation between retardation factor score and DPM, SPM, LVDV. Conclusion: The study indicated that there are noticeable changes in left ventricle preload and afterload, blood pressure, peripheral resistance, and microcirculation in depressive patients, and that the accompanying anxiety makes the changes more complicated.

  13. Clinical outcome of high-dose-rate interstitial brachytherapy in patients with oral cavity cancer

    International Nuclear Information System (INIS)

    To evaluate the clinical outcome of high-dose-rate (HDR) interstitial brachytherapy (IBT) in patients with oral cavity cancer. Sixteen patients with oral cavity cancer treated with HDR remote-control afterloading brachytherapy using 192Ir between 2001 and 2013 were analyzed retrospectively. Brachytherapy was administered in 11 patients as the primary treatment and in five patients as salvage treatment for recurrence after the initial surgery. In 12 patients, external beam radiotherapy (50-55 Gy/25 fractions) was combined with IBT of 21 Gy/7 fractions. In addition, IBT was administered as the sole treatment in three patients with a total dose of 50 Gy/10 fractions and as postoperative adjuvant treatment in one patient with a total of 35 Gy/7 fractions. The 5-year overall survival of the entire group was 70%. The actuarial local control rate after 3 years was 84%. All five recurrent cases after initial surgery were successfully salvaged using IBT +/- external beam radiotherapy. Two patients developed local recurrence at 3 and 5 months, respectively, after IBT. The acute complications were acceptable (< or =grade 2). Three patients developed major late complications, such as radio-osteonecrosis, in which one patient was treated by conservative therapy and two required surgical intervention. HDR IBT for oral cavity cancer was effective and acceptable in diverse clinical settings, such as in the cases of primary or salvage treatment.

  14. Criteria for the evaluation of brachytherapy for malignant brain tumors

    International Nuclear Information System (INIS)

    Thirty two patients with recurrent or unresectable malignant brain tumors were treated by interstitial brachytherapy with Ir-192 seeds. After-loading catheters were stereotactically implanted under local anesthesia using a Brown-Roberts-wells (BRW) CT guided stereotactic system. The response to the therapy was followed by serial CT and MRI scans and evaluated three months after implantation by the standard criteria for the evaluation of chemotherapy because there is no set of criteria available for radiation therapy. After interstitial brachytherapy, the most commonly observed CT and MRI finding was central low attenuation, that is, the central enhanced tumor replaced by the radiation necrosis. Three months after the treatment, these findings were observed in 23 patients out of 32 patients on the CT and MRI. We observed complete response (CR) in 6 of 32 patients, partial response (PR) in 9, no change (NC) in 7 and progressive disease (PD) in 9. In 6 CR patients, the tumor disappeared by three months after treatment. In 15 patients of 17 NC and PD patients, the central low attenuation was observed and their prognosis was better than those without central necrosis. The results suggested the standard criteria for the evaluation of chemotherapy, such as CR, PR etc, cannot be applicable to our series because the tumor mass replaced by necrotic tissue and remained as a mass lesion in most cases and new criteria in consideration of this low attenuation on CT and MRI will be needed for the evaluation of brachytherapy on neuroimagings. (author)

  15. Rationale and Description of Right Ventricle-Protective Ventilation in ARDS.

    Science.gov (United States)

    Paternot, Alexis; Repessé, Xavier; Vieillard-Baron, Antoine

    2016-10-01

    Pulmonary vascular dysfunction is associated with ARDS and leads to increased right-ventricular afterload and eventually right-ventricular failure, also called acute cor pulmonale. Interest in acute cor pulmonale and its negative impact on outcome in patients with ARDS has grown in recent years. Right-ventricular function in these patients should be closely monitored, and this is helped by the widespread use of echocardiography in intensive care units. Because mechanical ventilation may worsen right-ventricular failure, the interaction between the lungs and the right ventricle appears to be a key factor in the ventilation strategy. In this review, a rationale for a right ventricle-protective ventilation approach is provided, and such a strategy is described, including the reduction of lung stress (ie, the limitation of plateau pressure and driving pressure), the reduction of PaCO2 , and the improvement of oxygenation. Prone positioning seems to be a crucial part of this strategy by protecting both the lungs and the right ventricle, resulting in increased survival of patients with ARDS. Further studies are required to validate the positive impact on prognosis of right ventricle-protective mechanical ventilation.

  16. Quality assurance programme in high dose rate brachytherapy with Iridium-192 source. Recommendations of the French Medical Physicists Society

    International Nuclear Information System (INIS)

    A report on Quality Assurance in High Dose Rate brachytherapy with Iridium-192 source has been prepared by the task group of the Brachytherapy committee of the French Medical Physicists Society. This report provides recommendations on what should be tested, the methods to be used, the test frequencies and the tolerances. The Quality Assurance Programme concerns mainly the Q.A. on the treatment unit, the treatment planning system and the patient procedure. Tolerances and action levels are linked to international recommendations. Safety standards are linked to national legislation and to international recommendations. It is the responsibility of the Institution to verify that the source calibration provided by the manufacturer is correct. The calibration of the Iridium-192 source should be an in-air measurement of air-kerma using an ionization chamber. The recommended tolerance between manufacturer and Institution calibration is 3 %. Quality Control on remote afterloading systems should include consideration of the accuracy and reproducibility of positioning of sources in the applicators. Safety features must also be evaluated regularly and emergency procedures should be tested regularly and posted in a prominent place. After the detailed acceptance tests of dose calculation algorithm, routine checks should be done after software update. An independent dose calculation is recommended before treatment. The recommended agreement with the computer calculation should be within 10%. A written dosimetry report for each brachytherapy procedure is recommended to be inserted in patient charts. The results of all tests should be recorded in a logbook. Fault conditions should be carefully documented

  17. Image guided Brachytherapy: The paradigm of Gynecologic and Partial Breast HDR Brachytherapy

    Science.gov (United States)

    Diamantopoulos, S.; Kantemiris, I.; Konidari, A.; Zaverdinos, P.

    2015-09-01

    High dose rate (HDR) brachytherapy uses high strength radioactive sources and temporary interstitial implants to conform the dose to target and minimize the treatment time. The advances of imaging technology enable accurate reconstruction of the implant and exact delineation of high-risk CTV and the surrounding critical structures. Furthermore, with sophisticated treatment planning systems, applicator devices and stepping source afterloaders, brachytherapy evolved to a more precise, safe and individualized treatment. At the Radiation Oncology Department of Metropolitan Hospital Athens, MRI guided HDR gynecologic (GYN) brachytherapy and accelerated partial breast irradiation (APBI) with brachytherapy are performed routinely. Contouring and treatment planning are based on the recommendations of the GEC - ESTRO Working group. The task of this presentation is to reveal the advantages of 3D image guided brachytherapy over 2D brachytherapy. Thus, two patients treated at our department (one GYN and one APBI) will be presented. The advantage of having adequate dose coverage of the high risk CTV and simultaneous low doses to the OARs when using 3D image- based brachytherapy will be presented. The treatment techniques, equipment issues, as well as implantation, imaging and treatment planning procedures will be described. Quality assurance checks will be treated separately.

  18. Proposal of guidelines for quality assurance in radiation oncology in Slovakia

    International Nuclear Information System (INIS)

    According to the requirements of the Directive 97/43 EURATOM and the Slovak Government decree No. 340/2006 a quality assurance (QA) system have to be implemented into the practices of radiation oncology departments, harmonized with the international recommendations. For fulfilling this task was in the framework of the activities of the Slovak Health Ministry Commission for QA in radiology , created a group of specialists for preparation of Guidelines for various modalities of radiotherapy equipment and for treatment planning systems, including the standard working methods for quality control of technical and operational characteristics , as well as verification of the functional parameters in the treatment process. The proposed Guidelines are divided into the six specific parts, with following items: Medical electron accelerators; Therapy simulators; Superficial therapy with X-rays; Gamma extemal beam therapy; Remote afterloading brachytherapy; and Treatment planning systems. The main objectives of the guidelines are to formulate formally established quality controls during: Acceptance testing after installation; Commissioning by the necessary periodic quality controls; and Repairs or maintenance work that might alter the radiation situation. The presentation will describe the specific periodic quality controls, technical and functional characteristics of each equipment and of the treatment planning, as well as the tolerances, which prevent the undesirable impact on the radiation output and compliance with all relevant specified requirements. (authors)

  19. Prospective multi-center trial utilizing electronic brachytherapy for the treatment of endometrial cancer

    Directory of Open Access Journals (Sweden)

    Thropay John P

    2010-07-01

    Full Text Available Abstract Background A modified form of high dose rate (HDR brachytherapy has been developed called Axxent Electronic Brachytherapy (EBT. EBT uses a kilovolt X-ray source and does not require treatment in a shielded vault or a HDR afterloader unit. A multi-center clinical study was carried out to evaluate the success of treatment delivery, safety and toxicity of EBT in patients with endometrial cancer. Methods A total of 15 patients with stage I or II endometrial cancer were enrolled at 5 sites. Patients were treated with vaginal EBT alone or in combination with external beam radiation. Results The prescribed doses of EBT were successfully delivered in all 15 patients. From the first fraction through 3 months follow-up, there were 4 CTC Grade 1 adverse events and 2 CTC Grade II adverse events reported that were EBT related. The mild events reported were dysuria, vaginal dryness, mucosal atrophy, and rectal bleeding. The moderate treatment related adverse events included dysuria, and vaginal pain. No Grade III or IV adverse events were reported. The EBT system performed well and was associated with limited acute toxicities. Conclusions EBT shows acute results similar to HDR brachytherapy. Additional research is needed to further assess the clinical efficacy and safety of EBT in the treatment of endometrial cancer.

  20. Radiation therapy for carcinoma of the uterine cervix. Comparison of two brachytherapy schedules

    International Nuclear Information System (INIS)

    We compared the survival rates and late effects for two groups of cervical cancer patients treated with almost the same external radiotherapy but different remote afterloading systems (RALS) for high-dose-rate intracavitary radiation therapy regimens. A total of 218 patients with carcinoma of the uterine cervix were treated. For 98 patients, intracavitary brachytherapy was delivered with 6-7.5 Gy/fraction to Point A (Group A), and for 120, 5 Gy/fraction with a modified source step size (Group B). The 3-year cause-specific survival rates by stage and treatment schedule were Group A: 91% and Group B: 96% in Stage I, 89% and 92% in Stage II, 64% and 75% in Stage III, 44% and 69% in Stage IV. The survival curves did not reveal any statistically significant differences at any stage. The 3-year cumulative local failure rates were 14% in Group A and 7% in Group B (P = 0.1202), while the actuarial rates of developing rectal complication (Grade 2 or more) at 3 years were 25% in Group A and 4% in Group B (P < 0.0001). This retrospective analysis suggests that a low dose per fraction with modified source step size is advantageous because of yielding almost the same local control but with fewer rectal complications. (author)

  1. Pulsatile flow and simple flow control method during weaning period in centrifugal pump: toward more expanded usage in open heart surgery.

    Science.gov (United States)

    Nishida, H; Koyanagi, H; Endo, M; Suzuki, S; Oshiyama, H; Nojiri, C; Fukasawa, H; Akutsu, T

    1994-09-01

    To expand the usage of the centrifugal pump (CP) in open heart surgery, we performed two studies. In the first, we evaluated pulsatile flow in the CP. In vitro pump performance of the Terumo Capiox pump (TCP) and the Sarns Delphin pump (SDP) and increase of free hemoglobin (mg/dl) after driving 6 h were investigated using bovine blood. A roller pump (RP) was used as a comparison. Equally effective pulsatile flow was obtained in both CPs. Hemolysis was less severe in TCP (120 mg/dl) than SDP (210 mg/dl) and RP (320 mg/dl). In the second study, we evaluated a simple flow control method. Flow rate was easily controlled with step-wise clamping of 3-pronged tubing (Triple-flow) without changing rotational speed, regardless of afterload. Fluctuation of flow was much less with this method than with the rotational speed change method. The use of pulsatile flow of TCP, with its minimum increase of hemolysis and the easier flow control method during the weaning process, may expand the usage of CP in open heart surgery.

  2. LEFT VENTRICULAR FUNCTION CHANGES IN SEVERE ANEMIA BY ECHOCARDIOGRAPHY: A CORRELATION STUDY

    Directory of Open Access Journals (Sweden)

    Farquana

    2014-03-01

    Full Text Available BACKGROUND AND OBJECTIVES: In the last decade, anemia is recognized as an important cause of morbidity, a factor limiting physical activity, responsible for a poor quality of life, and a predictor of unfavorable outcomes. Anemia is emerging as a potential contributor to the development and progression of cardiovascular disease. Hence the present study was undertaken to correlate echocardiographic changes with anemic status. METHODOLOGY: Present study was conducted in Al-Ameen Medical College and Government district Hospital, Bijapur. 31 anemic patients (aged 18-40 yrs. with Hb ≤7 gm. % were selected. All anemic patients were subjected for hemoglobin estimation and M mode 2D Echocardiography. Echocardiographic parameters- IVSTd, LVIDd, LVPWd, IVSTs, LVIDs, LVPWS, EDV, ESV, SV, SI, CI, EF, FS were studied and correlated with hemoglobin levels. Statistical analysis was done by correlation analysis. RESULTS: LVPWd, IVSTs, IVStd, LVPWs did not correlate with hemoglobin levels. LVIDd, LVIDs, EDV, ESV, SV, SI, CI were negatively correlated with hemoglobin levels in anemic patients. No correlation observed for EF, FS. INTERPRETATION AND CONCLUSION: The findings of negative correlation of echo parameters with anemic status may be as a consequence of hyperdynamic circulatory state leading to vascular and cardiac changes. These changes are mainly due to increased preload, decreased afterload, changes in cardiac geometry. These factors increase systolic wall stress and over time lead to LV systolic dysfunction

  3. Measurement uncertainty in pulmonary vascular input impedance and characteristic impedance estimated from pulsed-wave Doppler ultrasound and pressure: clinical studies on 57 pediatric patients

    International Nuclear Information System (INIS)

    Pulmonary vascular input impedance better characterizes right ventricular (RV) afterload and disease outcomes in pulmonary hypertension compared to the standard clinical diagnostic, pulmonary vascular resistance (PVR). Early efforts to measure impedance were not routine, involving open-chest measurement. Recently, the use of pulsed-wave (PW) Doppler-measured velocity to non-invasively estimate instantaneous flow has made impedance measurement more practical. One critical concern remains with clinical use: the measurement uncertainty, especially since previous studies only incorporated random error. This study utilized data from a large pediatric patient population to comprehensively examine the systematic and random error contributions to the total impedance uncertainty and determined the least error prone methodology to compute impedance from among four different methods. We found that the systematic error contributes greatly to the total uncertainty and that one of the four methods had significantly smaller propagated uncertainty; however, even when this best method is used, the uncertainty can be large for input impedance at high harmonics and for the characteristic impedance modulus. Finally, we found that uncertainty in impedance between normotensive and hypertensive patient groups displays no significant difference. It is concluded that clinical impedance measurement would be most improved by advancements in instrumentation, and the best computation method is proposed for future clinical use of the input impedance

  4. The structural characteristics of radiation oncology in Japan in 2003

    International Nuclear Information System (INIS)

    Purpose: To ascertain the basic structural characteristics of radiation oncology facilities in Japan, we conducted a national survey on their status in 2003. The aims of the survey included the following: present status of radiation treatment facilities, equipment, personnel, patient loads, and other factors. Methods and Materials: A mail survey verified each potential facility delivering megavoltage radiation therapy and collected data on treatment devices, other equipment, personnel, new patients, and so on. Responses were obtained from 100% of potential facilities. Results: A total of 726 facilities delivered radiation therapy, with 859 megavoltage devices, 203 RALS (remote after-loading system) and other radioactive sources, with 941 FTE (full-time employee) radiation oncologists including 369 FTE Japanese Society of Therapeutic Radiation Oncology-certified radiation oncologists, 1555 FTE radiation therapists, and 70 FTE physicists in 2003. Megavoltage devices included two heavy ion units and four proton units. In total, there were 149,793 new patients and 146,351 (98%) by external irradiation; 4379 (3%) were treated by brachytherapy with or without external irradiation. Eighty-six percent of the facilities had treatment-planning computers, but 4% had no treatment-planning capability. Six percent (44 facilities) of all facilities used hyperthermia, 12% (85 facilities) intraoperative radiation therapy, and 2% (12 facilities) intensity-modulated radiation therapy. Conclusion: Facilities surveys continue to provide a source of census data on radiation oncology in Japan, allowing comparisons among facility groups and over time

  5. High dose rate sup 60 Co-RALS intraluminal radiation therapy for advanced biliary tract cancer with obstructive jaundice

    Energy Technology Data Exchange (ETDEWEB)

    Tamada, Toshiaki; Yoshimura, Hitoshi; Yoshioka, Tetsuya; Iwata, Kazuro; Ohishi, Hajime; Uchida, Hideo (Nara Medical Univ., Kashihara (Japan))

    1991-12-01

    High-dose-rate intraluminal irradiation with a {sup 60}Co remote afterloading system, using our newly developed applicator, was performed in 15 cases of advanced biliary tract cancer (2 gallbladder cancers, 13 cholangiocarcinomas). The applicator which was thin with an outer diameter of 14 Fr had a double lumen which included a small lumen for a guide wire for easy exchange to a drainage tube. Therefore, the irradiation procedure could be easily finished in a short time within little distress to the patient. The tumor marker CA1 19-9 was useful in assessing the therapeutic effect and follow-up observation after treatment. The average tube-free period and survival time were 5.9 months and 8.3 months, respectively. Histopathological examination of the cases autopsied showed that the combination of intraluminal (30 Gy) and external (30 Gy) irradiation offered good local control of the cancer that was within 1 cm from the source. Cholangiocarcinoma with relatively short length of obstruction, stage III or stage IV when the cancer infiltration was localized around the bile duct, achieved a comparatively long survival time. It was suggested that the combined use of high-dose-rate intraluminal radiotherapy, with precisely delivered radical radiation to tumors localized in the bile duct wall, and external radiotherapy delivered as additional radiation to the surrounding bile duct would provide radiotherapeutic advantage and contribute to survival after treatment for advanced biliary tract cancer. (author).

  6. Distinct right ventricle remodeling in response to pressure overload in the rat.

    Science.gov (United States)

    Mendes-Ferreira, P; Santos-Ribeiro, D; Adão, R; Maia-Rocha, C; Mendes-Ferreira, M; Sousa-Mendes, C; Leite-Moreira, A F; Brás-Silva, C

    2016-07-01

    Pulmonary arterial hypertension (PAH), the most serious chronic disorder of the pulmonary circulation, is characterized by pulmonary vasoconstriction and remodeling, resulting in increased afterload on the right ventricle (RV). In fact, RV function is the main determinant of prognosis in PAH. The most frequently used experimental models of PAH include monocrotaline- and chronic hypoxia-induced PAH, which primarily affect the pulmonary circulation. Alternatively, pulmonary artery banding (PAB) can be performed to achieve RV overload without affecting the pulmonary vasculature, allowing researchers to determine the RV-specific effects of their drugs/interventions. In this work, using two different degrees of pulmonary artery constriction, we characterize, in full detail, PAB-induced adaptive and maladaptive remodeling of the RV at 3 wk after PAB surgery. Our results show that application of a mild constriction resulted in adaptive hypertrophy of the RV, with preserved systolic and diastolic function, while application of a severe constriction resulted in maladaptive hypertrophy, with chamber dilation and systolic and diastolic dysfunction up to the isolated cardiomyocyte level. By applying two different degrees of constriction, we describe, for the first time, a reliable and short-duration PAB model in which RV adaptation can be distinguished at 3 wk after surgery. We characterize, in full detail, structural and functional changes of the RV in its response to moderate and severe constriction, allowing researchers to better study RV physiology and transition to dysfunction and failure, as well as to determine the effects of new therapies. PMID:27199115

  7. Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31P NMR)

    International Nuclear Information System (INIS)

    The authors assessed the metabolic and mechanical effects of changes in coronary perfusion pressure (CPP) and afterload (A) in isolated working apex-ejecting rat hearts perfused with Krebs-Henseleit solution containing an excess of O2 and substrate. Log(phosphorylation potential) or log (ATP)/(ADP)x (Pi), designated (L), and log (PCR)/(Pi), designated (L*), were calculated from HPLC measurements after rapid freeze-clamping. Increasing CPP from 80-140 cm H2O caused an increase in coronary flow(flow), developed pressure(DevP), O2 consumption (VO2), L, L*, and CO. L and L* were directly related to VO2 and CO. Increasing A from 80-140 cm H2O caused an increase in DevP and VO2, but a decrease in L, L*, and CO. L and L* were inversely linearly related to VO2 but were directly linearly related to CO. In both experiments, L and L* are directly related to CO, suggesting that determination of L* (which can be done with 31P NMR spectroscopy) may be a useful non-invasive method for determining cardiac pump function curves. L and L* may be related to the Frank-Starling mechanism. In a separate experiment using 31P NMR spectroscopy of isovolumic (left ventricular balloon) perfused rat hearts, increasing CPP caused a direct linear increase in flow, DevP, and L*, confirming the L* results reported above with CPP experiments using the rapid freeze-clamp technique

  8. Radiological protection of patients in brachytherapy

    International Nuclear Information System (INIS)

    Full text: The prefix 'brachy' means short-range, so brachytherapy is the administration of radiation therapy using small radioactive sources in the form of needles, tubes, wires or seeds, which are placed within the tumor -interstitial form- or very near of it, superficially or in an endo-cavity form. This technique, which was limited by the size of the primary tumor, has the advantage, that the radiation, can be adjusted to the size and shape of the tumor volume and the radioisotope used, - short range -, is selected with the criteria of getting the dose in the organs at risk, as low as possible, making what it is known as conformal radiotherapy. Radioactive sources may be permanent or temporary implants. The application of radioactive material, can be manually or automatically. In the first case, a major breakthrough from the radioprotection point of view, was the use of afterloading devices, methodology highly recommended to reduce the radiation exposure to staff. With the development of technology, remotely controlled afterloading devices were introduced, which in addition to complying with the above requirement, allow the source to move in different positions along catheters housed in one or more channels, making therapeutic brachytherapy treatments in tumor volumes possible, that due to its length, decades ago would have been an unthinkable deal. In all cases, sources, which may vary from the 3 mm in length, 125 Iodine or 198 Gold seeds, to extensive wires of 192 Iridium, are encapsulated for two main purposes: preventing leakage of radioactive material and absorption of unwanted radiation, alpha and beta, produced by the radioactive decay. Consequently, it should be highly unlikely that the radioactive material, could be lost or located in the patient, in a different place of the one that was planned. However, history shows us the opposite. Its is known the kind of deterministic effect that radiation is going to produce in the tumor, where the severity of

  9. Interstitial brachytherapy in carcinoma of the penis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, A.J.; Ghosh, S.; Bhalavat, R.L. [Tata Memorial Hospital, Mumbai (India). Dept. of Radiation Oncology; Kulkarni, J.N. [Tata Memorial Hospital, Mumbai (India). Dept. of Surgery; Sequeira, B.V.E. [Tata Memorial Hospital, Mumbai (India). Dept. of Medical Physics

    1999-01-01

    Aim: Keeping in line with the increasing emphasis on organ preservation, we at the Tata Memorial Hospital have evaluated the role of Ir-192 interstitial implant as regards local control, functional and cosmetic outcome in early as well as locally recurrent carcinoma of the distal penis. Patients and Methods: From October 1988 to December 1996, 23 patients with histopathologically proven cancer of the penis were treated with radical radiation therapy using Ir-192 temporary interstitial implant. Our patients were in the age group of 20 to 60 years. The primary lesions were T1 and 7, T2 in 7 and recurrent in 9 patients. Only 7 patients had palpable groin nodes at presentation, all of which were pathologically negative. The median dose of implant was 50 Gy (range 40 to 60 Gy), using the LDR afterloading system and the Paris system of implant rules for dosimetry. Follow-up ranged from 4 to 117 months (median 24 months). Results: At last follow-up 18 of the 23 patients remained locally controlled with implant alone. Three patients failed only locally, 2 locoregionally and 1 only at the groin. Of the 5 patients who failed locally, 4 were successfully salvaged with partial penectomy and remained controlled when last seen. Local control with implant alone at 8 years was 70% by life table analysis. The patients had excellent functional and cosmetic outcome. We did not record any case of skin or softtissue necrosis. Only 2 patients developed meatal stenosis, both of which were treated endoscopically. Conclusion: Our results lead us to interpret that interstitial brachytherapy with Ir-192 offers excellent local control rates with preservation of organ and function. Penectomy can be reserved as a means for effective salvage. (orig.) [Deutsch] Ziel: Das Prinzip des Organerhalts gewinnt in der Onkologie zunehmend an Bedeutung. Ziel dieser Untersuchung war es, die Rolle der interstitiellen Brachytherapie mit Ir-192 zur Behandlung des fruehen und rezidivierten Peniskarzinoms zu

  10. Assessment of left ventricular function in patients with atrial fibrillation by left ventricular filling and function curves determined by ECG gated blood pool scintigraphy

    International Nuclear Information System (INIS)

    Accurate cardiac function in patients with atrial fibrillation (Af) is difficult to assess, since a wide fluctuation of cardiac cycle makes the ventricular hemodynamics variable. Although ECG gated blood pool scintigraphy (EGBPS) is useful to evaluate left ventricular (LV) function, a conventional EGBPS might have a problem in applying to Af. Therefore, a new processing algorithm was devised to make multiple gated images discriminated by preceding R-R intervals (PRR), and LV filling and function curves were obtained in 62 patients with Af to evaluate LV function. LV filling curve, obtained by plotting end-diastolic volume (EDV) againt PRR, demonstrated that the blood filling was impaired in mitral stenosis and constrictive pericarditis, but recovered after mitral commissurotomy. LV function curve, by plotting stroke volume (SV) againt EDV, was quantitatively analysed by the indices such as Slope and Position. Both indices reduced significantly in heart failure. When compared among underlying diseases individually, the indices decreased in the following order; lone Af, hyperthyroidism, senile Af, hypertension, mitral valve disease, ischemic heart disease, dilated cardiomyopathy and aortic regurgitation. After the treatment with digitalis and/or diuretics, left and upward shift of function curve was observed. The rise in heart rate by atropine infusion made Slope and Position unchanged, and which implied that function curve was little influenced by heart rate per se. The rise in systolic blood pressure by angiotensin-II infusion caused shifts in function curve to rightward and downward. Downward shift, mostly seen in patients with gentler slope in control state, may imply afterload mismatch due to a decrease in preload reserve. (J.P.N.)

  11. Microwave hyperthermia radiosensitized iridium-192 for recurrent brain malignancy.

    Science.gov (United States)

    Borok, T L; Winter, A; Laing, J; Paglione, R; Sterzer, F; Sinclair, I; Plafker, J

    1988-03-01

    Twenty-one patients whose solitary detectable biopsy proven recurrent brain malignancies produced Central Nervous System (CNS) symptoms warranting further intervention received 60-minute 43 degrees C (180 degree-minute) interstitial 2450 MHz microwave hyperthermia fractions. All received brain teletherapy prior to recurrence. The first 15 received no brachytherapy and served as a toxicity pilot. All 15 enjoyed neurologic improvement, 12 symptomatic improvement, and 12 objective response as mass reduction and/or tumor necrosis. The next 6 patients were selected with more favorable Karnofsky performance status, no known active malignancy elsewhere, and received afterloading Ir-192 interstitial implantation juxtaposed to radiosensitizing hyperthermia. Volume dose varied from 1000 to 2245 rad, and dose rate from 40 to 100 rad/hr. Dose selected varied as a function of pre-recurrence teletherapy dose, general condition, histologic type, and volume. Neurosurgical debulking, if technically indicated through no additional aperture or trauma, was permitted if consistent with preservation of neurological function. Six enjoyed neurologic improvement, symptom reduction, and objective tumor response; three remain alive, and one experienced transient improvement. Complications, histologic subtypes, autopsy findings, stereotactic approach, thermal monitoring methods and CT follow-up of objective response are presented along with computer dosimetry and isotherm chart. Our microtraumatic universal catheter technique for CT guided stereotactic biopsy, aspiration, decompression, thermal sensory loop, thermalization antennae, and brachytherapy without multiple trauma nor changing catheters is stressed. The rationale for combined modes peculiar to the CNS will be outlined.2+ Proposal for incorporating controlled-release ARA-C chemotherapy polymer micro-rods into the interstitial format will be offered. The preceeding is an FDA-approved controlled clinical trial.(ABSTRACT TRUNCATED AT

  12. Physics and quality assurance of low dose rate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: The purpose of this course is to review the physical principles underlying design, clinical application and execution of interstitial and intracavitary implants in the classical low dose-rate (LDR) range. This year, the course will focus on quality assurance of sources, applicators and treatment planning software. In addition, development of procedures and QA checks designed optimize treatment delivery accuracy and patient safety during each individual procedure will be reviewed. The level of presentation will be designed to accommodate both physicists and physicians. Implementation of recently published AAPM Task Group reports (no. 40, 'Comprehensive Quality Assurance' and No. 43, 'Dosimetry of Interstitial Brachytherapy Sources') will be reviewed. Outline: (A) General Principles (1) QA endpoints: temporal accuracy, positional accuracy, dose delivery accuracy, and safety of the patient, personnel, and the institution (2) QA procedure development: forms, checklists, test development and design of treatment delivery procedures (B) QA of treatment delivery devices (1) Source acceptance testing and QA a) calibration and source strength specification standards b) leakage tests and source geometry verification (2) Applicator acceptance testing and QA (3) Remote afterloading devices (4) Treatment planning systems a) graphic input/output devices, implant geometry reconstruction, and graphical display b) dose calculation accuracy i) review of brachytherapy dose calculation algorithms ii) dosimetric benchmarks available: Task Group 43 report (C) Procedure-specific QA 1) Organization of treatment delivery team 2) Preplanning and preparation 3) Applicator insertion 4) Radiographic examination of the implant, prescription, and treatment calculation 5) Source insertion 6) Treatment planning and physicist review of treatment plans 7) QA during patient treatment and removal of sources and applicators

  13. Intraluminal High-Dose-Rate Brachytherapy for the Tumors of Gastrointestinal Tract

    International Nuclear Information System (INIS)

    Purpose : Intraluminal High dose rate brachytherapy is an accepted treatment for the tumors of GI tract. However, there is only some limited clinical data for intraluminal high dose rate brachytherapy for the tumors of GI tract. Materials and Methods : Between February 1991 and July 1993, 18 patients who have the tumors of GI tract (esophageal cancer-8 cases, rectal cancer-10 cases) were treated with high dose rae iridium-192 afterloading system )Microselectron-HDR, Nucletron CO, Netherland) at the department of therapeutic radiology, St. Mary's hospital, Catholic university medical college. Age rage was 47-87 years with a mean age 71 years. All patients were treated with intraluminal high dose rate brachytherapy within two weeks after conventional external radiation therapy and received 3-5 Gy/fraction 3-4 times per week to a total dose 12-20 Gy (mean 17 Gy). Standard fractionation and conventional dose were delivered for external radiation therapy. Total dose of external radiation therapy ranged 41.4-59.4 Gy (mean 49.6 Gy). Median follow up was 19 months. Results : The analysis was based on 18 patients. The complete response and partial response in esophageal cancer was similar (38%). Two year rates for survival and median survival were 13% and 10 months, respectively. Among 10 patients of rectal cancers, partial response was obtained in 6 patients (60%). There was no complete response in the patients with rectal cancer, but good palliative results were achieved in all patients. Conclusion : Although the number of patients was not large and the follow up period was relatively short, these findings suggested that intraluminal high dose rate brachytherapy could be useful in the treatment of the patients with advanced tumors of GI tract

  14. Salvage surgery for nasopharyngeal cancer

    Institute of Scientific and Technical Information of China (English)

    Raymond K.Tsang; William I.Wei

    2015-01-01

    Nasopharyngeal carcinoma (NPC) is a special type of head and neck cancer with a widely variable geographical variation in incidence.The central location of the tumor inside the head coupled with the radiosensitivity of the tumor to radiation made radiation therapy the first choice in primary treatment of NPC.Advances in radiotherapy and chemotherapy have markedly improved the local control of NPC.Unfortunately, a small but significant number of patients still suffered from loco-regional failures that would be amenable to re-treatment.Traditional form of retreatment was to employ a second course of radiation.The efficacy of re-irradiation to treat local of regional recurrent NPC has been suboptimal.Moreover, the local tissue had already received a high dose of radiation and the second radiation could result in radiation toxicities to the local tissue, leading to significant complications.Surgical salvage, on the other hand, could spare the patients from complications of retreatment.Due to the difficult access of the nasopharynx, various surgical approaches had been devised for nasopharyngectomy.The maxillary swing approach had the largest published experience with over 300 cases from various centers.In the recent decade, the endoscopic approach with or without robotic assistance had gained popularity for resecting small, centrally located recurrences.This minimally invasive approach further reduced the morbidity for treating locally recurrent NPC.Nodal recurrences had been a rare entity after the introduction of modern radiotherapy technique and concurrent chemotherapy.Treatment of nodal failure with second radiation has dismal results.Surgical removal of the lymph node harboring the recurrence should be in the form of a formal radical neck dissection.In cases of extensive nodal recurrence where microscopic disease may be present after a formal neck dissection, additional radiotherapy can be delivered with after-loading brachytherapy.Surgical treatment played a

  15. Dosimetry evaluation of SAVI-based HDR brachytherapy for partial breast irradiation

    Directory of Open Access Journals (Sweden)

    Manoharan Sivasubramanian

    2010-01-01

    Full Text Available Accelerated partial breast irradiation (APBI with high dose rate (HDR brachytherapy offers an excellent compact course of radiation due to its limited number of fractions for early-stage carcinoma of breast. One of the recent devices is SAVI (strut-adjusted volume implant, which has 6, 8 or 10 peripheral source channels with one center channel. Each channel can be differentially loaded. This paper focuses on the treatment planning, dosimetry and quality assurance aspects of HDR brachytherapy implant with GammaMed Plus HDR afterloader unit. The accelerated PBI balloon devices normally inflate above 35 cc range, and hence these balloon type devices cannot be accommodated in small lumpectomy cavity sizes. CT images were obtained and 3-D dosimetric plans were done with Brachyvision planning system. The 3-D treatment planning and dosimetric data were evaluated with planning target volume (PTV_eval V90, V95, V150, V200 skin dose and minimum distance to skin. With the use of the SAVI 6-1 mini device, we were able to accomplish an excellent coverage - V90, V95, V150 and V200 to 98%, 95%, 37 cc (<50 cc volume and 16 cc (<20 cc volume, respectively. Maximum skin dose was between 73% and 90%, much below the prescribed dose of 34 Gy. The minimum skin distance achieved was 5 to 11 mm. The volume that received 50% of the prescribed radiation dose was found to be lower with SAVI. The multi-channel SAVI-based implants reduced the maximum skin dose to markedly lower levels as compared to other modalities, simultaneously achieving best dose coverage to target volume. Differential-source dwell-loading allows modulation of the radiation dose distribution in symmetric or asymmetric opening of the catheter shapes and is also advantageous in cavities close to chest wall.

  16. High dose rate intraluminal irradiation in recurrent endobronchial carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Seagren, S.L.; Harrell, J.H.; Horn, R.A.

    1985-12-01

    Palliative therapy for previously irradiated patients with symptomatic recurrent endobronchial malignancy is a difficult problem. We have had the opportunity to treat 20 such patients with high dose rate (50-100 rad/min) endobronchial brachytherapy. Eligible patients had received previous high dose thoracic irradiation (TDF greater than or equal to 90), a performance status of greater than or equal to 50, and symptoms caused by a bronchoscopically defined and implantable lesion. The radiation is produced by a small cobalt-60 source (0.7 Ci) remotely afterloaded by cable control. The source is fed into a 4 mm diameter catheter which is placed with bronchoscopic guidance; it may oscillate if necessary to cover the lesion. A dose of 1,000 rad at 1 cm from the source is delivered. We have performed 22 procedures in 20 patients, four following YAG laser debulking. Most had cough, some with hemoptysis. Eight had dyspnea secondary to obstruction and three had obstructive pneumonitis. In 12, symptoms recurred with a mean time to recurrence of 4.3 months (range 1-9 months). Eighteen patients were followed-up and reexamined via bronchoscope 1-2.5 months following the procedure; two were lost to follow-up. All had at least 50 percent clearance of tumor, and six had complete clearance; most regressions were documented on film or videotape. In six, the palliation was durable. The procedure has been well tolerated with no toxicity. We conclude that palliative endobronchial high dose rate brachytherapy is a useful palliative modality in patients with recurrent endobronchial symptomatic carcinoma.

  17. ED 02-3 CLINICAL IMPLICATIONS OF CENTRAL HEMODYNAMICS ON AORTIC AND END-ORGAN DISEASES.

    Science.gov (United States)

    Hashimoto, Junichiro

    2016-09-01

    The central aorta constitutes the main trunk of the systemic arterial tree. It dilates passively with cardiac ejection during systole and then constricts with its recoil function during diastole, thereby regulating blood pressure and blood flow. The central pulsatile hemodynamics affects local hemodynamics within as well as downstream of the aorta (e.g., end organs).The aorta progressively stiffens and dilates with advancing age, and such age-dependent change is accelerated by hypertension. According to the law of Laplace, wall stress depends on the diameter and pressure of the blood vessel. This has been confirmed by substantial studies which have associated baseline aortic diameter with subsequent development of aortic dissection and progressive dilatation of aortic lumen. This law can also imply potential importance of local pressure within the aorta (i.e., the central pressure) in predicting the development and progression of aortic aneurysms.Several previous studies have shown that hypertension (together with age and obesity) is related to dilatation of the proximal ascending aorta (rather than of the aortic root). In addition, aortic blood flow abnormality may also be importantly related to aortic dilatation because of strong positive association between the diastole flow reversal and lumen diameter in the proximal thoracic aorta. As for the abdominal (infrarenal) aorta, aneurysmal development and progression have been attributed to aortic segmental stiffening (of the bifurcational versus infrarenal segment) and aortic pressure elevation, respectively.Central pulsatile pressure not only represents aortic wall stress but also determines cardiac afterload and microvascular wall stress in the brain and kidney. Central pulsatile flow (in both directions) could also affect the flow distribution into the upper and lower parts of the body and control end-organ function. Aortic structural change (including segmental stiffening and aneurysmal formation) causes central

  18. HDR {sup 192}Ir source speed measurements using a high speed video camera

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Viana, Rodrigo S. S.; Yoriyaz, Hélio [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Podesta, Mark [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Rubo, Rodrigo A.; Sales, Camila P. de [Hospital das Clínicas da Universidade de São Paulo—HC/FMUSP, São Paulo 05508-000 (Brazil); Reniers, Brigitte [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Research Group NuTeC, CMK, Hasselt University, Agoralaan Gebouw H, Diepenbeek B-3590 (Belgium); Verhaegen, Frank, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec H3G 1A4 (Canada)

    2015-01-15

    Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

  19. A workshop on developing risk assessment methods for medical use of radioactive material. Volume 1: Summary

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, J.P. [ed.] [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)

    1995-08-01

    A workshop was held at the Idaho National Engineering Laboratory, August 16--18, 1994 on the topic of risk assessment on medical devices that use radioactive isotopes. Its purpose was to review past efforts to develop a risk assessment methodology to evaluate these devices, and to develop a program plan and a scoping document for future methodology development. This report contains a summary of that workshop. Participants included experts in the fields of radiation oncology, medical physics, risk assessment, human-error analysis, and human factors. Staff from the US Nuclear Regulatory Commission (NRC) associated with the regulation of medical uses of radioactive materials and with research into risk-assessment methods participated in the workshop. The workshop participants concurred in NRC`s intended use of risk assessment as an important technology in the development of regulations for the medical use of radioactive material and encouraged the NRC to proceed rapidly with a pilot study. Specific recommendations are included in the executive summary and the body of this report. An appendix contains the 8 papers presented at the conference: NRC proposed policy statement on the use of probabilistic risk assessment methods in nuclear regulatory activities; NRC proposed agency-wide implementation plan for probabilistic risk assessment; Risk evaluation of high dose rate remote afterloading brachytherapy at a large research/teaching institution; The pros and cons of using human reliability analysis techniques to analyze misadministration events; Review of medical misadministration event summaries and comparison of human error modeling; Preliminary examples of the development of error influences and effects diagrams to analyze medical misadministration events; Brachytherapy risk assessment program plan; and Principles of brachytherapy quality assurance.

  20. NEW ADVANCES IN BETA-BLOCKER THERAPY IN HEART FAILURE

    Directory of Open Access Journals (Sweden)

    Vincenzo eBarrese

    2013-11-01

    Full Text Available The use of -blockers (BB in heart failure (HF has been considered a contradiction for many years. Considering HF simply as a state of inadequate systolic function, BB were contraindicated because of their negative effects on myocardial contractility. Nevertheless, evidence collected in the past years have suggested that additional mechanisms, such as compensatory neuro-humoral hyperactivation or inflammation, could participate in the pathogenesis of this complex disease. Indeed, chronic activation of the sympathetic nervous system, although initially compensating the reduced cardiac output from the failing heart, increases myocardial oxygen demand, ischemia and oxidative stress; moreover, high catecholamine levels induce peripheral vasoconstriction and increase both cardiac pre- and after-load, thus determining additional stress to the cardiac muscle (1. As a consequence of such a different view of the pathogenic mechanisms of HF, the efficacy of BB in the treatment of HF has been investigated in numerous clinical trials. Results from these trials highlighted BB as valid therapeutic tools in HF, providing rational basis for their inclusion in many HF treatment guidelines. However, controversy still exists about their use, in particular with regards to the selection of specific molecules, since BB differ in terms of adrenergic -receptors selectivity, adjunctive effects on -receptors, and effects on reactive oxygen species and inflammatory cytokines production. Further concerns about the heterogeneity in the response to , as well as the use in specific patients, are matter of debate among clinicians. In this review, we will recapitulate the pharmacological properties and the classification of BB, and the alteration of the adrenergic system occurring during HF that provide a rationale for their use; we will also focus on the possible molecular mechanisms, such as genetic polymorphisms, underlying the different efficacy of molecules

  1. Population pharmacokinetics of olprinone in healthy male volunteers

    Directory of Open Access Journals (Sweden)

    Kunisawa T

    2014-03-01

    Full Text Available Takayuki Kunisawa,1 Hidefumi Kasai,2 Makoto Suda,2 Manabu Yoshimura,3 Ami Sugawara,3 Yuki Izumi,3 Takafumi Iida,3 Atsushi Kurosawa,3 Hiroshi Iwasaki3 1Surgical Operation Department, Asahikawa Medical University Hospital, Hokkaido, Japan; 2Clinical Study Management Division, Bell Medical Solutions Inc, Tokyo, Japan; 3Department of Anesthesiology and Critical Care Medicine, Asahikawa Medical University, Hokkaido, Japan Background: Olprinone decreases the cardiac preload and/or afterload because of its vasodilatory effect and increases myocardial contractility by inhibiting phosphodiesterase III. Purpose: The objective of this study was to characterize the population pharmacokinetics of olprinone after a single continuous infusion in healthy male volunteers. Methods: We used 500 plasma concentration data points collected from nine healthy male volunteers for the study. The population pharmacokinetic analysis was performed using the nonlinear mixed effect model (NONMEM® software. Results: The time course of plasma concentration of olprinone was best described using a two-compartment model. The final pharmacokinetic parameters were total clearance (7.37 mL/minute/kg, distribution volume of the central compartment (134 mL/kg, intercompartmental clearance (7.75 mL/minute/kg, and distribution volume of the peripheral compartment (275 mL/kg. The interindividual variability in the total clearance was 12.4%, and the residual error variability (exponential and additive were 22.2% and 0.129 (standard deviation. The final pharmacokinetic model was assessed using a bootstrap method and visual predictive check. Conclusion: We developed a population pharmacokinetic model of olprinone in healthy male adults. The bootstrap method and visual predictive check showed that this model was appropriate. Our results might be used to develop the population pharmacokinetic model in patients. Keywords: phosphodiesterase III inhibitor, men, pharmacokinetic model

  2. Evaluation of Proximal Aortic Elastic Properties in Non-Ischemic Dilated Cardiomyopathy by Trans-Thoracic Echocardiography: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Alireza Moaref

    2015-06-01

    Full Text Available Background: Stiffening of the large vessels, especially aorta, plays a significant role in increasing the left ventricular work and aggravating the cardiovascular diseases by attenuating the vascular wall distensibility and its buffering effect. Objectives: This study aimed to compare the stiffness of proximal aorta in the patients with established diagnosis of Non-Ischemic Dilated Cardiomyopathy (NIDC and the normal population. Patients and Methods: This case-control study aimed to compare 50 patients with established diagnosis of NIDC and 50 individuals with no history of significant cardiovascular diseases in the outpatient echocardiography clinics affiliated to Shiraz University of Medical Sciences, Shiraz, Iran during a three-month period in 2011. The patients with aortic valve disorders, coronary artery disease, congenital heart disease, diabetes mellitus, hypertension, and renal failure were excluded from the study. Stiffness indices were determined using the data gathered via echocardiography (left ventricular ejection fraction, end-systolic and end-diastolic volumes, and internal aortic diameter and blood pressure measurement. Ordinal and quantitative data were analyzed by Chi-square and independent T-test, respectively using the SPSS statistical software, version 16.0. Besides, P < 0.05 was considered as statistically significant. Results: The results of this study revealed significantly lower aortic strain (0.05 ± 0.02 in the NIDC patients versus 0.20 ± 0.46 in the controls, P < 0.001 and brachial pulse pressure (40.50 ± 9.00 in the NIDC patients versus 45.90 ± 8.08 in the controls, P < 0.001 in the NIDC patients. Conclusions: Aortic stiffness is capable of deteriorating the cardiovascular function by augmenting the afterload. Thus, it should be seriously considered as an issue while approaching NIDC patients since they demonstrate lower aortic distensibility.

  3. Astaxanthin vs placebo on arterial stiffness, oxidative stress and inflammation in renal transplant patients (Xanthin: a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Robertson Iain K

    2008-12-01

    Full Text Available Abstract Background There is evidence that renal transplant recipients have accelerated atherosclerosis manifest by increased cardiovascular morbidity and mortality. The high incidence of atherosclerosis is, in part, related to increased arterial stiffness, vascular dysfunction, elevated oxidative stress and inflammation associated with immunosuppressive therapy. The dietary supplement astaxanthin has shown promise as an antioxidant and anti-inflammatory therapeutic agent in cardiovascular disease. The aim of this trial is to investigate the effects of astaxanthin supplementation on arterial stiffness, oxidative stress and inflammation in renal transplant patients. Method and Design This is a randomised, placebo controlled clinical trial. A total of 66 renal transplant recipients will be enrolled and allocated to receive either 12 mg/day of astaxanthin or an identical placebo for one-year. Patients will be stratified into four groups according to the type of immunosuppressant therapy they receive: 1 cyclosporine, 2 sirolimus, 3 tacrolimus or 4 prednisolone+/-azathioprine, mycophenolate mofetil or mycophenolate sodium. Primary outcome measures will be changes in 1 arterial stiffness measured by aortic pulse wave velocity (PWV, 2 oxidative stress assessed by plasma isoprostanes and 3 inflammation by plasma pentraxin 3. Secondary outcomes will include changes in vascular function assessed using the brachial artery reactivity (BAR technique, carotid artery intimal medial thickness (CIMT, augmentation index (AIx, left ventricular afterload and additional measures of oxidative stress and inflammation. Patients will undergo these measures at baseline, six and 12 months. Discussion The results of this study will help determine the efficacy of astaxanthin on vascular structure, oxidative stress and inflammation in renal transplant patients. This may lead to a larger intervention trial assessing cardiovascular morbidity and mortality. Trial Registration

  4. Intrauterine endotoxin-induced impairs pulmonary vascular function and right ventricular performance in infant rats and improvement with early vitamin D therapy.

    Science.gov (United States)

    Mandell, Erica; Powers, Kyle N; Harral, Julie W; Seedorf, Gregory J; Hunter, Kendall S; Abman, Steven H; Dodson, R Blair

    2015-12-15

    High pulmonary vascular resistance (PVR), proximal pulmonary artery (PA) impedance, and right ventricular (RV) afterload due to remodeling contribute to the pathogenesis and severity of pulmonary hypertension (PH). Intra-amniotic exposure to endotoxin (ETX) causes sustained PH and high mortality in rat pups at birth, which are associated with impaired vascular growth and RV hypertrophy in survivors. Treatment of ETX-exposed pups with antenatal vitamin D (vit D) improves survival and lung growth, but the effects of ETX exposure on RV-PA coupling in the neonatal lung are unknown. We hypothesized that intrauterine ETX impairs RV-PA coupling through sustained abnormalities of PA stiffening and RV performance that are attenuated with vit D therapy. Fetal rats were exposed to intra-amniotic injections of ETX, ETX+vit D, or saline at 20 days gestation (term = 22 days). At postnatal day 14, pups had pressure-volume measurements of the RV and isolated proximal PA, respectively. Lung homogenates were assayed for extracellular matrix (ECM) composition by Western blot. We found that ETX lungs contain decreased α-elastin, lysyl oxidase, collagen I, and collagen III proteins (P < 0.05) compared control and ETX+vit D lungs. ETX-exposed animals have increased RV mechanical stroke work (P < 0.05 vs. control and ETX+vit D) and elastic potential energy (P < 0.05 vs. control and ETX+vit D). Mechanical stiffness and ECM remodeling are increased in the PA (P < 0.05 vs. control and ETX+vit D). We conclude that intrauterine exposure of fetal rats to ETX during late gestation causes persistent impairment of RV-PA coupling throughout infancy that can be prevented with early vit D treatment.

  5. Effects of arterial and venous volume infusion on coronary perfusion pressures during canine CPR.

    Science.gov (United States)

    Gentile, N T; Martin, G B; Appleton, T J; Moeggenberg, J; Paradis, N A; Nowak, R M

    1991-08-01

    Intraarterial (IA) volume infusion has been reported to be more effective than intravenous (IV) infusion in treating cardiac arrest due to exsanguination. A rapid IA infusion was felt to raise intraaortic pressure and improve coronary perfusion pressure (CPP). The purpose of this study was to determine if IA or IV volume infusion could augment the effect of epinephrine on CPP during CPR in the canine model. Nineteen mongrel dogs with a mean weight of 26.3 +/- 4.2 kg were anesthetized and mechanically ventilated. Thoracic aortic (Ao), right atrial (RA) and pulmonary artery catheters were placed for hemodynamic monitoring. Additional Ao and central venous catheters were placed for volume infusion. Ventricular fibrillation was induced and Thumper CPR was begun after 5 min (t = 5). At t = 10, all dogs received 45 micrograms/kg IV epinephrine. Six animals received epinephrine alone (EPI). Five dogs received EPI plus a 500 cc bolus of normal saline over 3 min intravenously (EPI/IV). Another group (n = 8) received EPI plus the same fluid bolus through the aortic catheter (EPI/IA). Resuscitation was attempted at t = 18 using a standard protocol. There was a significant increase in CPP over baseline in all groups. The changes in CPP from baseline induced by EPI, EPI/IV and EPI/IA were 20.6 +/- 3.7, 22.8 +/- 4.2 and 22.2 +/- 2.4 mmHg, respectively. Volume loading did not augment the effect of therapeutic EPI dosing. By increasing both preload and afterload, volume administration may in fact be detrimental during CPR. PMID:1658894

  6. [Doppler echocardiographic evaluation of vasodilator treatments in patients with cardiac insufficiency. Contribution to the combination of isosorbide dinitrate and captopril].

    Science.gov (United States)

    Dubourg, O; Jondeau, G; Beauchet, A; Delorme, G; Chikli, F; Weber, S; Bejuit, R; Bourdarias, J P

    1992-04-01

    Hemodynamic evaluation of a vasodilator drug is a difficult exercise in which Doppler echocardiography can be a useful tool. We studied the hemodynamic effect of isosorbide dinitrate (ISDN) by Doppler echocardiography in 7 patients with severe cardiac failure despite prolonged therapy with usually effective doses of captopril. The patients were evaluated before (H0) and 24 hours after treatment by ISDN (120 mg/24 hr) (H24) and 10 minutes after sublingual 0.75 mg of trinitrin (H24 + T). M mode echocardiography did not show any significant changes in chamber dimension as reported after vasodilator therapy in patients without cardiac dilation: in patients with severe left ventricular dilatation a reduction in LV filling pressures causes little if any changes in fractional shortening and ventricular dimensions. Two-dimensional echocardiography showed a reduction in end systolic volume and an increase in ejection fraction, emphasizing the superiority of this technique in cases of abnormal left ventricular function and the sensitivity of indices of systolic function to changes in afterload in these patients. Cardiac output measured by Doppler increased during the study. The maximal acceleration did not change significantly and pulmonary artery pressures were stable after administration of nitrates. ISDN caused a marked change in diastolic mitral flow patterns for which there are several explanations: an effect of ISDN on relaxation or LV compliance or on the conditions of LV filling or on both factors together. The presence of mitral regurgitation and/or atrial arrhythmia prevents the use of Doppler indices for analysis of diastolic LV function.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. [PHYSICAL EXERCISE TRAINING CAN- CELS CONSTITUTIVE NOS UNCOUPLING AND INDUCED VIOLATIONS OF CARDIAC HEMODYNAMICS IN HYPERTENSION (PART III)].

    Science.gov (United States)

    Dorofeyeva, N A; Kotsuruba, A V; Kopjak, B S; Sagach, V F

    2015-01-01

    In the heart and heart mitochondria spontaneously hypertensive rats investigated the effect of physical exercise training (swimming in a moderate and excessive training mode) on the physiological indicators of cardiac hemodynamics and biochemical parameters that characterize the level of oxidative and nitrosative stress. The index of coupling Ca(2+)-dependent constitutive NO-synthases (cNOS = eNOS + nNOS) and biochemical index of dysfunction were calculated. It turned out that both modes of training is completely restored, and even exceed the reference values in untrained rats Wistar conjugate cNOS state and Ca(2+)-dependent synthesis of nitric oxide (NO). Intensity regime of exercise on the border of functionality have been ineffective for improving the functional state of the cardiovascular system and hypertension can provoke it further. Moderate physical training regime, on the contrary, improves the diastolic function of the heart due to an increase dP/dtmin, reducing end-diastolic pressure and a significant reduction in end-diastolic stiffness. Moderate exercise decreased peripheral resistance and cardiac afterload, as indicated by the decrease in end-systolic pressure and arterial stiffness, which contributed to more efficient and energy-saving of heart work. Improve physiological indicators of cardiac hemodynamics and functional state of the heart in moderate mode of training correlated with changes in both the calculated indices. Moderate mode of training is recommended as a simple physiological preconditioning method for the prevention of cardiac dysfunction, hypertension as a result of state uncoupling cNOS and the resulting excessive generation of superoxide and, conversely, inhibition of Ca(2+)-dependent synthesis of NO. PMID:26552300

  8. Experimental exposure to diesel exhaust increases arterial stiffness in man

    Directory of Open Access Journals (Sweden)

    Newby David E

    2009-03-01

    Full Text Available Abstract Introduction Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness. Methods In a double-blind randomized fashion, 12 healthy volunteers were exposed to diesel exhaust (approximately 350 μg/m3 or filtered air for one hour during moderate exercise. Arterial stiffness was measured using applanation tonometry at the radial artery for pulse wave analysis (PWA, as well as at the femoral and carotid arteries for pulse wave velocity (PWV. PWA was performed 10, 20 and 30 min, and carotid-femoral PWV 40 min, post-exposure. Augmentation pressure (AP, augmentation index (AIx and time to wave reflection (Tr were calculated. Results Blood pressure, AP and AIx were generally low reflecting compliant arteries. In comparison to filtered air, diesel exhaust exposure induced an increase in AP of 2.5 mmHg (p = 0.02 and in AIx of 7.8% (p = 0.01, along with a 16 ms reduction in Tr (p = 0.03, 10 minutes post-exposure. Conclusion Acute exposure to diesel exhaust is associated with an immediate and transient increase in arterial stiffness. This may, in part, explain the increased risk for cardiovascular disease associated with air pollution exposure. If our findings are confirmed in larger cohorts of susceptible populations, this simple non-invasive method of assessing arterial stiffness may become a useful technique in measuring the impact of real world exposures to combustion derived-air pollution.

  9. Uterine cervix cancer associated with pregnancy:Report of 5 cases%妊娠相关性宫颈癌5例临床治疗体会

    Institute of Scientific and Technical Information of China (English)

    陆云燕; 刘蓉; 徐海波

    2011-01-01

    Objective:To explore the diangnosis , treatment and prognosis of cervical cancer associated with pregnancy. Methods: From January 2003 to November 2009,5 patients were treated with surgery, radiotherapy and chemotherapy. Regimens chemotherapy with VBP, TP and afterloading intracavitary treatment of cobalt before surgery, TP before external irradiation were performed. Results:Aee patients were with worse pathological differentiation , the right diagnosis all delayed , all 5 patients had rapidly progressive disease, 2 patients dead in 6 months, 1 patient dead in 12 months, 1 patient dead in 17 months. Conclusion:The prognosis of cervical cancer associated with pregnancy is very poor,early diagnosis is very important.%目的:探讨妊娠相关性宫颈癌的诊断、治疗及预后.方法:从2003年1月至2009年11月对收治的5例妊娠相关性宫颈癌患者进行手术、化疗、放疗.术前采用VBP、TP方案及后装治疗,根治性放疗前采用TP方案化疗.结果:5例妊娠相关性宫颈癌分化程度低,发现时病期较晚,病情发展较快,2例6月内死亡,1例12个月死亡,1例17个月死亡.结论:妊娠相关性宫颈癌预后差,早期诊断很重要,治疗方案个体化.

  10. Evaluation of Physiological Control Systems for Rotary Left Ventricular Assist Devices: An In-Vitro Study.

    Science.gov (United States)

    Pauls, Jo P; Stevens, Michael C; Bartnikowski, Nicole; Fraser, John F; Gregory, Shaun D; Tansley, Geoff

    2016-08-01

    Rotary left ventricular assist devices (LVADs) show weaker response to preload and greater response to afterload than the native heart. This may lead to ventricular suction or pulmonary congestion, which can be deleterious to the patient's recovery. A physiological control system which optimizes responsiveness of LVADs may reduce adverse events. This study compared eight physiological control systems for LVAD support against constant speed mode. Pulmonary (PVR) and systemic (SVR) vascular resistance changes, a passive postural change and exercise were simulated in a mock circulation loop to evaluate the controller's ability to prevent suction and congestion and to increase exercise capacity. Three active and one passive control systems prevented ventricular suction at high PVR (500 dyne s cm(-5)) and low SVR (600 dyne s cm(-5)) by decreasing LVAD speed (by 200-515 rpm) and by increasing LVAD inflow cannula resistance (up to 1000 dyne s cm(-5)) respectively. These controllers increased LVAD preload sensitivity (to 0.196-2.415 L min(-1) mmHg(-1)) compared to the other control systems and constant speed mode (0.039-0.069 L min(-1) mmHg(-1)). The same three active controllers increased pump speed (600-800 rpm) and thus LVAD flow by 4.5 L min(-1) during exercise which increased exercise capacity. Physiological control systems that prevent adverse events and/or increase exercise capacity may help improve LVAD patient conditions. PMID:26833037

  11. A workshop on developing risk assessment methods for medical use of radioactive material. Volume 1: Summary

    International Nuclear Information System (INIS)

    A workshop was held at the Idaho National Engineering Laboratory, August 16--18, 1994 on the topic of risk assessment on medical devices that use radioactive isotopes. Its purpose was to review past efforts to develop a risk assessment methodology to evaluate these devices, and to develop a program plan and a scoping document for future methodology development. This report contains a summary of that workshop. Participants included experts in the fields of radiation oncology, medical physics, risk assessment, human-error analysis, and human factors. Staff from the US Nuclear Regulatory Commission (NRC) associated with the regulation of medical uses of radioactive materials and with research into risk-assessment methods participated in the workshop. The workshop participants concurred in NRC's intended use of risk assessment as an important technology in the development of regulations for the medical use of radioactive material and encouraged the NRC to proceed rapidly with a pilot study. Specific recommendations are included in the executive summary and the body of this report. An appendix contains the 8 papers presented at the conference: NRC proposed policy statement on the use of probabilistic risk assessment methods in nuclear regulatory activities; NRC proposed agency-wide implementation plan for probabilistic risk assessment; Risk evaluation of high dose rate remote afterloading brachytherapy at a large research/teaching institution; The pros and cons of using human reliability analysis techniques to analyze misadministration events; Review of medical misadministration event summaries and comparison of human error modeling; Preliminary examples of the development of error influences and effects diagrams to analyze medical misadministration events; Brachytherapy risk assessment program plan; and Principles of brachytherapy quality assurance

  12. LV reverse remodeling imparted by aortic valve replacement for severe aortic stenosis; is it durable? A cardiovascular MRI study sponsored by the American Heart Association

    Directory of Open Access Journals (Sweden)

    Caruppannan Ketheswaram

    2011-04-01

    Full Text Available Abstract Background In patients with severe aortic stenosis (AS, long-term data tracking surgically induced effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiovascular MRI (CMR offers the ability to serially track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability. Hypothesis We hypothesize that changes in LV structure and function following aortic valve replacement (AVR are detectable by CMR and once triggered by AVR, continue for an extended period. Methods Tweny-four patients of which ten (67 ± 12 years, 6 female with severe, but compensated AS underwent CMR pre-AVR, 6 months, 1 year and up to 4 years post-AVR. 3D LV mass index, volumetrics, LV geometry, and EF were measured. Results All patients survived AVR and underwent CMR 4 serial CMR's. LVMI markedly decreased by 6 months (157 ± 42 to 134 ± 32 g/m2, p 2. Similarly, EF increased pre to post-AVR (55 ± 22 to 65 ± 11%,(p 2. LV stroke volume increased rapidly from pre to post-AVR (40 ± 11 to 44 ± 7 ml, p Conclusion After initial beneficial effects imparted by AVR in severe AS patients, there are, as expected, marked improvements in LV reverse remodeling. Via CMR, surgically induced benefits to LV structure and function are durable and, unexpectedly express continued, albeit markedly incomplete improvement through 4 years post-AVR concordant with sustained improved clinical status. This supports down-regulation of both mRNA and MMP activity acutely with robust suppression long term.

  13. Ovalis TAH: development and in vitro testing of a new electromechanical energy converter for a total artificial heart.

    Science.gov (United States)

    Sauer, I M; Frank, J; Spiegelberg, A; Bücherl, E S

    2000-01-01

    A new electromechanical energy converting system has been developed to yield an efficient and durable orthotopic total artificial heart (TAH). The energy converter we developed transforms the unidirectional rotational motion of the motor into a longitudinal forward-reverse movement of an internal geared oval, linked directly to pusher plates on both sides. To ensure a permanent positive connection between the drive gear and the internally geared wheel, a ball bearing runs inside an oval shaped guide track. Motor, gear unit, and conical pusher plates are seated between alternately ejecting and filling ventricles. The unidirectional motion of the brushless DC motor affords easier motor control, reduces energy demand, and ensures longer life of the motor when compared with a bidirectional motion system. In vitro testing has been performed on a mock circulation loop. The overall system efficiency of the TAH Ovalis was 27-39% (mean, 36%) for the pump output range of 2-7 L/min. The maximum output of 7 L/min can be obtained with a pump rate of 130 min(-1) and an afterload pressure of 140 mm Hg. For an average sized human with a mean cardiac output of 6 L/min at a mean aortic pressure of 120 mm Hg, 5 watts of input power would be required. The size of the prototype is 560 cm3, the weight is 950 g. Our first in vitro studies demonstrated the excellent efficiency and pump performance of this new electromechanical energy converter. The results prove the feasibility of this new concept's use as an energy converter for a total artificial heart. PMID:11110274

  14. Development of an Animal Model for Burn-Blast Combined Injury and Cardiopulmonary System Changes in the Early Shock Stage.

    Science.gov (United States)

    Hu, Quan; Chai, Jiake; Hu, Sen; Fan, Jun; Wang, Hong-Wei; Ma, Li; Duan, Hong-Jie; Liu, Lingying; Yang, Hongming; Li, Bai-Ling; Wang, Yi-He

    2015-12-01

    The purposes of this study were to establish an animal model for burn-blast combined injury research and elaborate cardiopulmonary system changes in the early shock stage. In this study, royal demolition explosive or RDX (hexagon, ring trimethylene nitramine) was used as an explosive source, and the injury conditions of the canine test subjects at various distances to the explosion (30, 50, and 70 cm) were observed by gross anatomy and pathology to determine a larger animal model of moderate blast injury. The canines were then subjected to a 35 % total body surface area (TBSA) full-thickness flame injury using napalm, which completed the development of a burn-blast combined injury model. Based on this model, the hemodynamic changes and arterial blood gas analysis after the burn-blast combined injury were measured to identify the cardiopulmonary system characteristics. In this research, RDX explosion and flame injury were used to develop a severe burn-blast injury animal model that was stable, close to reality, and easily controllable. The hemodynamic and arterial blood gas changes in the canine subjects after burn-blast injury changed distinctly from the burn and blast injuries. Blood pressure and cardiac output fluctuated, and the preload was significantly reduced, whereas the afterload significantly increased. Meanwhile, the oxygen saturation (SO2) decreased markedly with carbon dioxide partial pressure (PCO2), and lactic acid (Lac) rose, and oxygen partial pressure (PO2) reduced. These changes suggested that immediate clinical treatment is important during burn-blast injury both to stabilize cardiac function and supply blood volume and to reduce the vascular permeability, thereby preventing acute pneumonedema or other complications. PMID:27011494

  15. 17β-Estradiol mediates superior adaptation of right ventricular function to acute strenuous exercise in female rats with severe pulmonary hypertension.

    Science.gov (United States)

    Lahm, Tim; Frump, Andrea L; Albrecht, Marjorie E; Fisher, Amanda J; Cook, Todd G; Jones, Thomas J; Yakubov, Bakhtiyor; Whitson, Jordan; Fuchs, Robyn K; Liu, Aiping; Chesler, Naomi C; Brown, M Beth

    2016-08-01

    17β-Estradiol (E2) exerts protective effects on right ventricular (RV) function in pulmonary arterial hypertension (PAH). Since acute exercise-induced increases in afterload may lead to RV dysfunction in PAH, we sought to determine whether E2 allows for superior RV adaptation after an acute exercise challenge. We studied echocardiographic, hemodynamic, structural, and biochemical markers of RV function in male and female rats with sugen/hypoxia (SuHx)-induced pulmonary hypertension, as well as in ovariectomized (OVX) SuHx females, with or without concomitant E2 repletion (75 μg·kg(-1)·day(-1)) immediately after 45 min of treadmill running at 75% of individually determined maximal aerobic capacity (75% aerobic capacity reserve). Compared with males, intact female rats exhibited higher stroke volume and cardiac indexes, a strong trend for better RV compliance, and less pronounced increases in indexed total pulmonary resistance. OVX abrogated favorable RV adaptations, whereas E2 repletion after OVX markedly improved RV function. E2's effects on pulmonary vascular remodeling were complex and less robust than its RV effects. Postexercise hemodynamics in females with endogenous or exogenous E2 were similar to hemodynamics in nonexercised controls, whereas OVX rats exhibited more severely altered postexercise hemodynamics. E2 mediated inhibitory effects on RV fibrosis and attenuated increases in RV collagen I/III ratio. Proapoptotic signaling, endothelial nitric oxide synthase phosphorylation, and autophagic flux markers were affected by E2 depletion and/or repletion. Markers of impaired autophagic flux correlated with endpoints of RV structure and function. Endogenous and exogenous E2 exerts protective effects on RV function measured immediately after an acute exercise challenge. Harnessing E2's mechanisms may lead to novel RV-directed therapies. PMID:27288487

  16. 350m塔楼顶部皇冠钢结构施工过程模拟分析%SIMULATION ANALYSIS OF THE CONSTRUCTION PROCESS OF STEEL CROWN STRUCTURE AT THE TOP OF 350 METER-HIGH BUILDING

    Institute of Scientific and Technical Information of China (English)

    段海; 汪晓阳; 张希博; 柳超; 彭湃

    2015-01-01

    通过对沈阳市府恒隆广场350 m 高塔楼顶部的皇冠钢结构施工过程进行模拟分析,简要介绍了复杂钢结构施工过程模拟分析的方法、步骤、施工阶段划分的原则、条件假定、临时支撑的反力分析、加固结构的承载力分析以及后装缺口的变形控制等,通过施工阶段模拟分析的方法,来确定施工方案、优化施工顺序,确保施工方案的可行性、科学性,同时避免盲目施工所带来的结构安全和质量隐患。%ABSTRACT:Through the simulation analysis of the construction process of steel crown structure at the top of 350-meter-high building of Hang Lung Plaza in Shenyang,this paper briefly introduced the simulation analysis of the construction process of complex steel structure in terms of the approaches, the steps,the principles of the construction stage division,the assumption of conditions,the reaction force analysis of temporary supports,the bearing capacity analysis of the reinforced structure,as well as the analysis of the deformation control of the afterloading gaps and so on.The construction scheme was identified and the construction sequence was optimized through simulation analysis of construction process,thus the feasibility and scientificity of the construction scheme was confirmed which could avoid the quality problems caused by blind construction.

  17. Captopril-induced reduction of regurgitation fraction in aortic insufficiency

    Energy Technology Data Exchange (ETDEWEB)

    Kropp, J.; Reske, S.N.; Biersack, H.J.; Heck, I.; Mattern, H.; Winkler, C.

    1984-01-01

    Stimulated Renin-Angiotensin System (RAS) in aortic insufficiency (AI) leads to increased afterload and consequently to augmented aortic regurgitation (R). Therefore Captopril (C) mediated RAS-inhibition should diminish systemic vascular resistance and thus reduce R. In 9 patients (pts) with pure severe AI regurgitation fraction (RF) and left ventricular ejection fraction (LVEF) were determined before and 1 hr after i.v. injection of 25 mg C by gated radionuclide ventriculographie (RNV), using red blood cells labeled in vivo with 15 mCi Tc-99m. Enddiastolic and endsystolid frames were derived from the left ventricular volume curve. ROI's were selected over both ventricles. Ventricular boundaries were defined by a fourier phase image overlay. RF was calculated by the background corrected count rate ratio of left and right ventricular ROI. Arterial blood pressure (BP), heart rate (HR), plasma levels of angiotensin I, II (A1,A2), and the activity of angiotensin converting enzyme (ACE) were determined before and 1 hr after C-injection. Before C-medication mean RF was 54% (range 34% - 67%), after C mean RF decreased to 37% (17% - 59% range, rho<.05). Mean LVEF increased not significantly from 60% (range 51%-70%) to 66% (range 56% - 77%, rho>0.55). C did not significantly change HR or BP (HR: rho>0.9, BP: rho>0.6). A2 and ACE activity decreased to 40% and 50% of control values (rho<.01), respectively. A1 increased excessively. The authors conclude that the inhibition of ACE reduces significantly aortic regurgitation in patients with A1 and has thus a beneficial effect on left ventricular performance.

  18. Effects of chronic dietary nitrate supplementation on the hemodynamic response to dynamic exercise.

    Science.gov (United States)

    Lee, Jae-Seok; Stebbins, Charles L; Jung, Eunji; Nho, Hosung; Kim, Jong-Kyung; Chang, Myoung-Jei; Choi, Hyun-Min

    2015-09-01

    While acute treatment with beetroot juice (BRJ) containing nitrate (NO3 (-)) can lower systolic blood pressure (SBP), afterload, and myocardial O2 demand during submaximal exercise, effects of chronic supplementation with BRJ (containing a relatively low dose of NO3 (-), 400 mg) on cardiac output (CO), SBP, total peripheral resistance (TPR), and the work of the heart in response to dynamic exercise are not known. Thus, in 14 healthy males (22 ± 1 yr), we compared effects of 15 days of both BRJ and nitrate-depleted beetroot juice (NDBRJ) supplementation on plasma concentrations of NOx (NO3 (-)/NO2 (-)), SBP, diastolic blood pressure (DBP), mean arterial pressure (MAP), CO, TPR, and rate pressure product (RPP) at rest and during progressive cycling exercise. Endothelial function was also assessed via flow-mediated dilation (FMD). BRJ supplementation increased plasma NOx from 83.8 ± 13.8 to 167.6 ± 13.2 μM. Compared with NDBRJ, BRJ reduced SBP, DBP, MAP, and TPR at rest and during exercise (P < 0.05). In addition, RPP was decreased during exercise, while CO was increased, but only at rest and the 30% workload (P < 0.05). BRJ enhanced FMD-induced increases in brachial artery diameter (pre: 12.3 ± 1.6%; post: 17.8 ± 1.9%). We conclude that 1) chronic supplementation with BRJ lowers blood pressure and vascular resistance at rest and during exercise and attenuates RPP during exercise and 2) these effects may be due, in part, to enhanced endothelium-induced vasodilation in contracting skeletal muscle. Findings suggest that BRJ can act as a dietary nutraceutical capable of enhancing O2 delivery and reducing work of the heart, such that exercise can be performed at a given workload for a longer period of time before the onset of fatigue. PMID:26084693

  19. Evaluation of time, attendance of medical staff, and resources during interstitial brachytherapy for prostate cancer. DEGRO-QUIRO trial

    International Nuclear Information System (INIS)

    The German Society of Radiation Oncology initiated a multicenter trial to evaluate core processes and subprocesses of radiotherapy by prospective evaluation of all important procedures in the most frequent malignancies treated by radiation therapy. The aim of this analysis was to assess the required resources for interstitial high-dose-rate (HDR) and low-dose-rate (LDR) prostate brachytherapy (BRT) based on actual time measurements regarding allocation of personnel and room occupation needed for specific procedures. Two radiotherapy centers (community hospital of Offenbach am Main and community hospital of Eschweiler) participated in this prospective study. Working time of the different occupational groups and room occupancies for the workflow of prostate BRT were recorded and methodically assessed during a 3-month period. For HDR and LDR BRT, a total of 560 and 92 measurements, respectively, were documented. The time needed for treatment preplanning was median 24 min for HDR (n=112 measurements) and 6 min for LDR BRT (n=21). Catheter implantation with intraoperative HDR real-time planning (n=112), postimplantation HDR treatment planning (n=112), and remotely controlled HDR afterloading irradiation (n=112) required median 25, 39, and 50 min, respectively. For LDR real-time planning (n=39) and LDR treatment postplanning (n=32), the assessed median duration was 91 and 11 min, respectively. Room occupancy and overall mean medical staff times were 194 and 910 min respectively, for HDR, and 113 and 371 min, respectively, for LDR BRT. In this prospective analysis, the resource requirements for the application of HDR and LDR BRT of prostate cancer were assessed methodically and are presented for first time. (orig.)

  20. Occupational monitoring in intracavitary radium therapy

    International Nuclear Information System (INIS)

    In Brazil, the highest incidence of cancer in females is in the uterine cervix, in which Bracytherapy treatment plays a very important role. The majority of our Clinics use 226Ra or 137Cs tubes to perform this therapy. As many of these Clinics do not use the afterloading technique, we investigated the occupational exposure for the staffs belonging to two big Hospitals in Rio de Janeiro, where the working conditions are very different. For this, besides the normal film badge, placed in the upper part of the trunk, each person has been provided with seven additional thermoluminescent dosimeters (chips - 7LiF) placed at: left ring finger, right ring finger, forehead (between the eyes), over the thyroid, in the midle of the back and the front of the trunk, and over the gonadal region. In Hospital A, where the staff is composed of 1 medical doctor and 1 nurse, they treat about 13 patients per month. In Hospital B, the staff was composed of 12 medical doctors, 2 technicians and 7 murses, and about 20 patients are treated monthly. The occupational exposures have been investigated separately for each step of the 226Ra routine. From these results we could easily identify that: the nurses working in the infermary do not use the lateral lead protection of beds to clean the patients; in Hospital B, where there are perfect conditions for storage and manipulation of the radioactive sources, the technician in charge of these tasks, together with the transport of the applicator, except in his hands, suffers no exposure at all. Besides that, we could also see that in Hospital A, where the nurse plays also the role of that technician, and the local protection conditions are not correct, the estimated annual exposures are still below the annual limits according to ICRP N0. 26/1977. This analysis has been completed with measures of occupational exposures in Clinics using the after loading technique. (author)

  1. HDR 192Ir source speed measurements using a high speed video camera

    International Nuclear Information System (INIS)

    Purpose: The dose delivered with a HDR 192Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a 192Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases

  2. [Evaluation of the addition of counterpulsation to the partial left ventricular-femoral bypass for limitation of evolving myocardial infarction].

    Science.gov (United States)

    Yamaguchi, A; Ide, H; Ino, T; Adachi, H; Mizuhara, A; Kawahito, K; Murata, S

    1994-08-01

    The effect of adding counterpulsation to a partial left ventricular bypass was evaluated in a canine model of acute myocardial ischemia by using a myocardial staining method. To establish a left ventricular bypass, a catheter consisting of bypass tube (90 cm in length and 15 Fr in inner diameter) and an accompanying intraaortic balloon as a single apparatus (Integrated Cardioassist Catheter; ICAC) was introduced into the left ventricle via the abdominal aorta. The left ventricular bypass was adjusted to 1 L/min. with or without counterpulsation with the aid of a centrifugal pump and IABP console. The use of the ICAC that provided pulsatile left ventricular bypass tended to raise the mean aortic pressure and cardiac output. Reduction of the tension time index was noted with the use of the ICAC in contrast to the control. And increment of the DPTI/TTI ratio was observed with the use of the ICAC in contrast to the control and partial left ventricular bypass alone. While the percentages of the region at risk were similar [17.3 +/- 9.5% (control), vs. 16.4 +/- 3.4% (partial left ventricular bypass alone) vs. 16.9 +/- 5.2% (ICAC)], the percentages of infarct sizes were reduced due to the use of counterpulsation. [61.9 +/- 12.2% (control), vs. 57.5 +/- 3.9% (partial left ventricular bypass alone) vs. 16.8 +/- 6.0% (ICAC)]. These results revealed that the addition of counterpulsation alleviates afterload reduction to the partial left ventricular bypass and was more beneficial to the reduction of the infarct size than partial left ventricular bypass alone. PMID:7963829

  3. The development and application of a radiofrequency (RF) interstitial hyperthermia system to prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Nobue; Kawaguchi, Atsuya; Moriyama, Masahiro; Kitagaki, Hajime; Urakami, Shinji; Igawa, Mikio [Shimane Medical Univ., Izumo (Japan); Kato, Hirokazu [Okayama Univ. (Japan). School of Medicine; Kasai, Toshifumi [Kyoto Coll. of Medical Technology, Sonobe (Japan)

    2002-09-01

    To heat a greater volume less invasively and more effectively, we developed a multi-channel RF interstitial hyperthermia system compatible with the high-dose rate Iridium-192 remote after-loading system (Ir-192 RALS). The system is composed of eight channel RF signal generators, which can be controlled individually. Each RF generator can be connected to an internal electrode, which was originally an Ir-192 RALS applicator; and a shared rectangular external electrode made of aluminum. By means of experiments using an agar phantom and an animal liver, we evaluated the heating characteristics, safety, and feasibility of this system. Subsequently, we applied trans-perineal radiofrequency (RF) interstitial hyperthermia and Ir-192 RALS for localized prostate cancer (PC). Under trans-rectal ultrasound guidance, 18 stainless applicators for Ir-192 RALS were inserted into the prostatic gland and seminal vesicles in an optimized pattern. Eight applicators were used as internal electrodes and were electrically insulated along the length of subdermal fat tissue using a vinyl catheter. The temperature inside the prostate and rectum was monitored continuously. Hyperthermia was performed following the first and fourth Ir-192 RALS (total of 24 Gy/4 fractions). Total doses of 46 Gy were also delivered by linear accelerator. There were no complications, such as infection, bleeding, fat necrosis, or burns. Histological examination after the treatment revealed cancer cell death and necrosis. MRI and CT images showed a well-demarcated, low-intensity area at the center of the prostate reflecting the necrotic area. Trans-perineal hyperthermoradiotherapy is a feasible and effective therapeutic alternative for the treatment of patients with localized PC. In addition, our system is compatible with the Ir-192 RALS, allowing for less-invasive interstitial hyperthermoradiotherapy by eliminating the trauma of needle re-insertion. (author)

  4. Non-invasive estimation and control of inlet pressure in an implantable rotary blood pump for heart failure patients.

    Science.gov (United States)

    Alomari, A H; Savkin, A V; Ayre, P J; Lim, E; Mason, D G; Salamonsen, R F; Fraser, J F; Lovell, N H

    2011-08-01

    We propose a dynamical model for mean inlet pressure estimation in an implantable rotary blood pump during the diastolic period. Non-invasive measurements of pump impeller rotational speed (ω), motor power (P), and pulse width modulation signal acquired from the pump controller were used as inputs to the model. The model was validated over a wide range of speed ramp studies, including (i) healthy (C1), variations in (ii) heart contractility (C2); (iii) afterload (C2, C3, C4), and (iv) preload (C5, C6, C7). Linear regression analysis between estimated and extracted mean inlet pressure obtained from in vivo animal data (greyhound dogs, N = 3) resulted in a highly significant correlation coefficients (R(2) = 0.957, 0.961, 0.958, 0.963, 0.940, 0.946, and 0.959) and mean absolute errors of (e = 1.604, 2.688, 3.667, 3.990, 2.791, 3.215, and 3.225 mmHg) during C1, C2, C3, C4, C5, C6, and C7, respectively. The proposed model was also used to design a controller to regulate mean diastolic pump inlet pressure using non-invasively measured ω and P. In the presence of model uncertainty, the controller was able to track and settle to the desired input within a finite number of sampling periods and minimal error (0.92 mmHg). The model developed herein will play a crucial role in developing a robust control system of the pump that detects and thus avoids undesired pumping states by regulating the inlet pressure within a predefined physiologically realistic limit. PMID:21666292

  5. Pharmacokinetics and pharmacodynamics of intravenous inotropic agents.

    Science.gov (United States)

    Lehtonen, Lasse A; Antila, Saila; Pentikäinen, Pertti J

    2004-01-01

    Positive inotropic drugs have various mechanisms of action. Long-term use of cyclic adenosine monophosphate (cAMP)-dependent drugs has adverse effects on the prognosis of heart failure patients, whereas digoxin has neutral effect on mortality. There are, however, little data on the effects of intravenous inotropic drugs on the outcome of patients. Intravenous inotropic agents are used to treat cardiac emergencies and refractory heart failure. beta-Adrenergic agonists are rapid acting and easy to titrate, with short elimination half-life. However, they increase myocardial oxygen consumption and are thus hazardous during myocardial ischaemia. Furthermore they may promote myocyte apoptosis. Phosphodiesterase (PDE) III inhibiting drugs (amrinone, milrinone and enoximone) increase contractility by reducing the degradation of cAMP. In addition, they reduce both preload and afterload via vasodilation. Short-term use of intravenous milrinone is not associated with increased mortality, and some symptomatic benefit may be obtained when it is used in refractory heart failure. Furthermore, PDE III inhibitors facilitate weaning from the cardiopulmonary bypass machine after cardiac surgery. Levosimendan belongs to a new group of positive inotropic drugs, the calcium sensitisers. It has complex pharmacokinetics and long-lasting haemodynamic effects as a result of its active metabolites. In comparative trials, it has been better tolerated than the most widely used beta-agonist inotropic drug, dobutamine. The pharmacokinetics of the intravenous inotropic drugs might sometimes greatly modify and prolong the response to the therapy, for example because of long-acting active metabolites. These drugs display considerable differences in their pharmacokinetics and pharmacodynamics, and the selection of the most appropriate inotropic drug for each patient should be based on careful consideration of the clinical status of the patient and on the pharmacology of the drug.

  6. Inhalation of the BK(Ca-opener NS1619 attenuates right ventricular pressure and improves oxygenation in the rat monocrotaline model of pulmonary hypertension.

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    Marc Revermann

    Full Text Available BACKGROUND: Right heart failure is a fatal consequence of chronic pulmonary hypertension (PH. The development of PH is characterized by increased proliferation of vascular cells, in particular pulmonary artery smooth muscle cells (PASMCs and pulmonary artery endothelial cells. In the course of PH, an escalated right ventricular (RV afterload occurs, which leads to increased perioperative morbidity and mortality. BK(Ca channels are ubiquitously expressed in vascular smooth muscle cells and their opening induces cell membrane hyperpolarization followed by vasodilation. Moreover, BK activation induces anti-proliferative effects in a multitude of cell types. On this basis, we hypothesized that treatment with the nebulized BK channel opener NS1619 might be a therapy option for pulmonary hypertension and tested this in rats. METHODS: (1 Rats received monocrotaline injection for PH induction. Twenty-four days later, rats were anesthetized and NS1619 or the solvent was administered by inhalation. Systemic hemodynamic parameters, RV hemodynamic parameters, and blood gas analyses were measured before as well as 30 and 120 minutes after inhalation. (2 Rat PASMCs were stimulated with PDGF-BB in the presence and absence of NS1619. AKT, ERK1 and ERK2 activation were investigated by western blot analyses, and relative cell number was determined 48 hours after stimulation. RESULTS: Inhalation of a 12 µM and 100 µM NS1619 solution significantly reduced RV pressure without affecting systemic arterial pressure. Blood gas analyses demonstrated significantly reduced carbon dioxide and improved oxygenation in NS1619-treated animals pointing towards a considerable pulmonary shunt-reducing effect. In PASMC's, NS1619 (100 µM significantly attenuated PASMC proliferation by a pathway independent of AKT and ERK1/2 activation. CONCLUSION: NS1619 inhalation reduces RV pressure and improves oxygen supply and its application inhibits PASMC proliferation in vitro. Hence, BK

  7. Contrast-enhancing computed tomography ring in glioblastoma multiforme after intraoperative endocurietherapy

    International Nuclear Information System (INIS)

    The significance of the contrast-enhancing ring seen on serial follow-up postirradiation computed tomograms (CT) of the brain was evaluated in a group of 41 patients with glioblastoma multiforme (GM) who were treated in a phase I/II study by means of intraoperative remote afterloading endocurietherapy (ECT) with a high activity cobalt 60 probe (20.00 Gy) in one high-dose rate fraction), and conventional fractionated external-beam (EXRT) radiotherapy (60.00 Gy in 30 fractions in 7.5 weeks). All received minimum total tumor doses of 80.00 Gy. After completion of treatment, all patients were followed with serial CT scans of the brain. Two to 6 months after treatment, 27 of 41 patients developed the similar thin-walled, regular, contrast-enhancing CT rings with low-density attenuation inside and outside the ring. Postmortem study in two of these patients revealed that the thin-walled, regular, contrast-enhancing ring represented a continuous capsule of dilated cerebral vessels with inner low-density attenuation corresponding to necrosis, and outer low-density attenuation corresponding to edema. The CT appearance of the thin-walled, regular, contrast-enhancing ring produced after high-dose rate intraoperative ECT and EXRT is distinctly different from the CT ring characteristic of untreated or recurrent GM. After high-dose rate intracranial ECT and EXRT, the appearance of a post-ECT contrast-enhancing CT ring should not be automatically interpreted as recurrent disease as previously reported after conventional fractionated EXRT

  8. Functional and biocompatibility performances of an integrated Maglev pump-oxygenator.

    Science.gov (United States)

    Zhang, Tao; Cheng, Guangming; Koert, Andrew; Zhang, Juntao; Gellman, Barry; Yankey, G Kwame; Satpute, Aditee; Dasse, Kurt A; Gilbert, Richard J; Griffith, Bartley P; Wu, Zhongjun J

    2009-01-01

    To provide respiratory support for patients with lung failure, a novel compact integrated pump-oxygenator is being developed. The functional and biocompatibility performances of this device are presented. The pump-oxygenator is designed by combining a magnetically levitated pump/rotor with a uniquely configured hollow fiber membrane bundle to create an assembly free, ultracompact, all-in-one system. The hemodynamics, gas transfer and biocompatibility performances of this novel device were investigated both in vitro in a circulatory flow loop and in vivo in an ovine animal model. The in vitro results showed that the device was able to pump blood flow from 2 to 8 L/min against a wide range of pressures and to deliver an oxygen transfer rate more than 300 mL/min at a blood flow of 6 L/min. Blood damage tests demonstrated low hemolysis (normalized index of hemolysis [NIH] approximately 0.04) at a flow rate of 5 L/min against a 100-mm Hg afterload. The data from five animal experiments (4 h to 7 days) demonstrated that the device could bring the venous blood to near fully oxygen-saturated condition (98.6% +/- 1.3%). The highest oxygen transfer rate reached 386 mL/min. The gas transfer performance was stable over the study duration for three 7-day animals. There was no indication of blood damage. The plasma free hemoglobin and platelet count were within the normal ranges. No gross thrombus is found on the explanted pump components and fiber surfaces. Both in vitro and in vivo results demonstrated that the newly developed pump-oxygenator can achieve sufficient blood flow and oxygen transfer with excellent biocompatibility. PMID:19178439

  9. Artificial Heart Fluid Dynamics.

    Science.gov (United States)

    Mussivand, Tofigh Varcaneh

    Flow characteristics within pneumatic, pulsatile, and pusher plate prosthetic hearts were studied. The blood pumps evaluated were duplicates of pumps used for in vivo calf and for clinical implantation at the Cleveland Clinic Foundation. Human dura mater bioprosthetic, caged disk, and Bjork-Shiley tilting disk valves were employed in the pumps. Dual camera video tape and synchronized still photography were used to study flow patterns. Diffused light and a planar laser source provided illumination. The laser light was fanned into a plane with a thickness of 0.2 mm to 10 mm. Magnesium oxide and Amberlite particles were used as tracers. Aqueous-glycerol, aqueous-sucrose solutions and mineral oil were used as blood analog fluids. Inflow, outflow, drive, and afterload pressures, diaphragm motion, cardiac output, and heart rate were measured and recorded. An electrical circuit was developed to synchronize pump diaphragm motion with captured images of flow trajectories. After digitizing the trajectories, velocities, global and local turbulence, and shear stresses were obtained. Disturbed and recirculating zones were identified. Qualitative and quantitative analyses were performed using data obtained from the digitization of flow trajectories. Simultaneous turbulence and stasis were observed during most phases of the cardiac cycles in all the pumps tested. A maximum Reynold's shear stress of 2889 dynes/cm ^2 occurred at 120 beats per minute (bpm). The peak velocity was 146 cm/sec during systole. The identified regions of recirculation, low velocity and disturbed flow were shown to correlate with thrombosed areas of explanted blood pumps. The maximum calculated turbulence intensity was 106 cm/sec which occurred at 120 bpm during systole.

  10. Surface dose characterisation of the Varian Ir-192 HDR conical surface applicator set with a vertically orientated source

    International Nuclear Information System (INIS)

    Conical surface applicators with an Ir-192 high-dose-rate brachytherapy source are a common modality for the treatment of non-melanomatous skin cancer with high tumour control rates. Surface dose characterisation of the Varian Varisource GammaMed+ IX afterloader vertical type surface applicators is performed two dimensionally using high-resolution film dosimetry. The focus of this study was to determine if Varian surface applicators with a vertical source suffer from the dose distribution irregularities reported for comparable applicators. Our goal was to evaluate if the irregularities found affected treatment and dose output verification procedures. Ionisation chamber-based verification of applicator output was established according to guidelines provided by the manufacturer. For additional measurement of surface dose Gafchromic EBT3 film dosimetry was used. The term ''therapeutic dose'' was defined as 85 % of the prescribed dose level. For the 10 different applicator inserts evaluated, cold spots were observed. Mean cold spot size was 2.0 mm x 3.6 mm (± 0.6 mm). The cold spots were dosimetrically well below 85 % of the prescribed dose. The cold spot was situated 2.2 mm (1.4-2.7 mm) unilaterally from the central axis and caused general asymmetry in the dose profiles intersecting the cold spot area. A source tilt of approximately 8 (± 1 ) was determined for the source used for irradiation. A central underdosed area exceeding 15 % of the prescribed dose has not been previously reported. Source tilt was observed and found to affect clinical use and possibly treatment outcome in applicators using a vertically arranged source. Surface applicators with a vertically orientated source were subject to dose irregularities that could impact on chamber-based applicator output verification procedures. We recommend film dosimetry-backed applicator commissioning to avoid systematic errors. (orig.)

  11. Complex myograph allows the examination of complex muscle contractions for the assessment of muscle force, shortening, velocity, and work in vivo

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    Ruhschulte Hainer

    2008-07-01

    Full Text Available Abstract Background The devices used for in vivo examination of muscle contractions assess only pure force contractions and the so-called isokinetic contractions. In isokinetic experiments, the extremity and its muscle are artificially moved with constant velocity by the measuring device, while a tetanic contraction is induced in the muscle, either by electrical stimulation or by maximal voluntary activation. With these systems, experiments cannot be performed at pre-defined, constant muscle length, single contractions cannot be evaluated individually and the separate examination of the isometric and the isotonic components of single contractions is not possible. Methods The myograph presented in our study has two newly developed technical units, i.e. a. a counterforce unit which can load the muscle with an adjustable, but constant force and b. a length-adjusting unit which allows for both the stretching and the contraction length to be infinitely adjustable independently of one another. The two units support the examination of complex types of contraction and store the counterforce and length-adjusting settings, so that these conditions may be accurately reapplied in later sessions. Results The measurement examples presented show that the muscle can be brought to every possible pre-stretching length and that single isotonic or complex isometric-isotonic contractions may be performed at every length. The applied forces act during different phases of contraction, resulting into different pre- and after-loads that can be kept constant – uninfluenced by the contraction. Maximal values for force, shortening, velocity and work may be obtained for individual muscles. This offers the possibility to obtain information on the muscle status and to monitor its changes under non-invasive measurement conditions. Conclusion With the Complex Myograph, the whole spectrum of a muscle's mechanical characteristics may be assessed.

  12. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    Science.gov (United States)

    Balvert, Marleen; Gorissen, Bram L.; den Hertog, Dick; Hoffmann, Aswin L.

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2-5 cc. However, this comes at a cost of a reduction in D90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D90% against uncertainty in dwell positions for both models.

  13. Non-invasive estimation of myocardial efficiency using positron emission tomography and carbon-11 acetate - comparison between the normal and failing human heart

    International Nuclear Information System (INIS)

    We studied ten patients with idiopathic dilated cardiomyopathy (DCM) and 11 healthy normals by dynamic PET with 11C-acetate and either tomographic radionuclide ventriculography or cine magnetic resonance imaging. A ''stroke work index'' (SWI) was calculated by: SWI = systolic blood pressure x stroke volume/body surface area. To estimate myocardial efficiency, a ''work-metabolic index'' (WMI) was then obtained as follows: WMI = SWI x heart rate/k(mono), where k(mono) is the washout constant for 11C-acetate derived from mono-exponential fitting. In DCM patients, left ventricular ejection fraction was 19%±10% and end-diastolic volume was 92±28 ml/m2 (vs 64%±7% and 55±8 ml/m2 in normals, P2; P6 mmHg x ml/m2; P<0.001) were lower in DCM patients, too. Overall, the WMI correlated positively with ejection parameters (r=0.73, P<0.001 for ejection fraction; r=0.93, P<0.001 for stroke volume), and inversely with systemic vascular resistance (r=-0.77; P<0.001). There was a weak positive correlation between WMI and end-diastolic volume in normals (r=0.45; P=0.17), while in DCM patients, a non-significant negative correlation coefficient (r=-0.21; P=0.57) was obtained. In conclusion non-invasive estimates of oxygen consumption and efficiency in the failing heart were reduced compared with those in normals. Estimates of efficiency increased with increasing contractile performance, and decreased with increasing ventricular afterload. In contrast to normals, the failing heart was not able to respond with an increase in efficiency to increasing ventricular volume.(orig./MG) (orig.)

  14. Bladder Function Preservation With Brachytherapy, External Beam Radiation Therapy, and Limited Surger in Bladder Cancer Patients: Long-Term Results

    International Nuclear Information System (INIS)

    Purpose: To report long-term results of a bladder preservation strategy for muscle-invasive bladder cancer (MIBC) using external beam radiation therapy and brachytherapy/interstitial radiation therapy (IRT). Methods and Materials: Between May 1989 and October 2011, 192 selected patients with MIBC were treated with a combined regimen of preoperative external beam radiation therapy and subsequent surgical exploration with or without partial cystectomy and insertion of source carrier tubes for afterloading IRT using low dose rate and pulsed dose rate. Data for oncologic and functional outcomes were prospectively collected. The primary endpoints were local recurrence-free survival (LRFS), bladder function preservation survival, and salvage cystectomy-free survival. The endpoints were constructed according to the Kaplan-Meier method. Results: The mean follow-up period was 105.5 months. The LRFS rate was 80% and 73% at 5 and 10 years, respectively. Salvage cystectomy-free survival at 5 and 10 years was 93% and 85%. The 5- and 10-year overall survival rates were 65% and 46%, whereas cancer-specific survival at 5 and 10 years was 75% and 67%. The distant metastases-free survival rate was 76% and 69% at 5 and 10 years. Multivariate analysis revealed no independent predictors of LRFS. Radiation Therapy Oncology Group grade ≥3 late bladder and rectum toxicity were recorded in 11 patients (5.7%) and 2 patients (1%), respectively. Conclusions: A multimodality bladder-sparing regimen using IRT offers excellent long-term oncologic outcome in selected patients with MIBC. The late toxicity rate is low, and the majority of patients preserve their functional bladder

  15. Non-invasive estimation and control of inlet pressure in an implantable rotary blood pump for heart failure patients

    International Nuclear Information System (INIS)

    We propose a dynamical model for mean inlet pressure estimation in an implantable rotary blood pump during the diastolic period. Non-invasive measurements of pump impeller rotational speed (ω), motor power (P), and pulse width modulation signal acquired from the pump controller were used as inputs to the model. The model was validated over a wide range of speed ramp studies, including (i) healthy (C1), variations in (ii) heart contractility (C2); (iii) afterload (C2, C3, C4), and (iv) preload (C5, C6, C7). Linear regression analysis between estimated and extracted mean inlet pressure obtained from in vivo animal data (greyhound dogs, N = 3) resulted in a highly significant correlation coefficients (R2 = 0.957, 0.961, 0.958, 0.963, 0.940, 0.946, and 0.959) and mean absolute errors of (e = 1.604, 2.688, 3.667, 3.990, 2.791, 3.215, and 3.225 mmHg) during C1, C2, C3, C4, C5, C6, and C7, respectively. The proposed model was also used to design a controller to regulate mean diastolic pump inlet pressure using non-invasively measured ω and P. In the presence of model uncertainty, the controller was able to track and settle to the desired input within a finite number of sampling periods and minimal error (0.92 mmHg). The model developed herein will play a crucial role in developing a robust control system of the pump that detects and thus avoids undesired pumping states by regulating the inlet pressure within a predefined physiologically realistic limit

  16. Evaluation of time, attendance of medical staff, and resources during interstitial brachytherapy for prostate cancer. DEGRO-QUIRO trial

    Energy Technology Data Exchange (ETDEWEB)

    Tselis, N.; Zamboglou, N. [Sana Klinikum Offenbach, Department of Radiation Oncology, Offenbach am Main (Germany); Maurer, U. [St.-Antonius-Hospital, Strahlentherapie, Eschweiler (Germany); Popp, W. [Prime Networks AG, Basel (Switzerland); Sack, H. [University of Essen, Department of Radiation Oncology, Essen (Germany)

    2014-04-15

    The German Society of Radiation Oncology initiated a multicenter trial to evaluate core processes and subprocesses of radiotherapy by prospective evaluation of all important procedures in the most frequent malignancies treated by radiation therapy. The aim of this analysis was to assess the required resources for interstitial high-dose-rate (HDR) and low-dose-rate (LDR) prostate brachytherapy (BRT) based on actual time measurements regarding allocation of personnel and room occupation needed for specific procedures. Two radiotherapy centers (community hospital of Offenbach am Main and community hospital of Eschweiler) participated in this prospective study. Working time of the different occupational groups and room occupancies for the workflow of prostate BRT were recorded and methodically assessed during a 3-month period. For HDR and LDR BRT, a total of 560 and 92 measurements, respectively, were documented. The time needed for treatment preplanning was median 24 min for HDR (n=112 measurements) and 6 min for LDR BRT (n=21). Catheter implantation with intraoperative HDR real-time planning (n=112), postimplantation HDR treatment planning (n=112), and remotely controlled HDR afterloading irradiation (n=112) required median 25, 39, and 50 min, respectively. For LDR real-time planning (n=39) and LDR treatment postplanning (n=32), the assessed median duration was 91 and 11 min, respectively. Room occupancy and overall mean medical staff times were 194 and 910 min respectively, for HDR, and 113 and 371 min, respectively, for LDR BRT. In this prospective analysis, the resource requirements for the application of HDR and LDR BRT of prostate cancer were assessed methodically and are presented for first time. (orig.)

  17. Management of perioperative low cardiac output state without extracorporeal life support: What is feasible?

    Directory of Open Access Journals (Sweden)

    Kumar Girish

    2010-01-01

    Full Text Available A transient and reversible reduction in cardiac output-low cardiac output state (LCOS often occurs following surgery for congenital heart disease. Inappropriately managed LCOS is a risk factor for increased morbidity and death. LCOS may occasionally be progressive and refractory needing a period of "myocardial rest" with extracorporeal life support (ECLS. ECLS is currently considered a routine tool available for rapid deployment in most industrialized countries. Accumulated experience and refinements in technology have led to improving survivals - discharge survivals of 35%−50%, with almost 100% survival in select groups on elective left ventricular assist device. Thus, there is an increasing trend to initiate ECLS "early or electively in the operating room" in high-risk patients. India has a huge potential need for ECLS given the large number of infants presenting late with preexisting ventricular dysfunction or in circulatory collapse. ECLS is an expensive and resource consuming treatment modality and is not a viable therapeutic option in our country. The purpose of this paper is to reiterate an anticipatory, proactive approach to LCOS: (1 methods for early detection of evolving LCOS and (2 timely initiation of individualized therapy. This paper also explores what is feasible with the refinement of "simple, conventional, inexpensive strategies" for the management of LCOS. Therapy for LCOS should be multimodal based on the type of circulation and physiology. Our approach to LCOS includes: (1 intraoperative strategies, (2 aggressive afterload reduction, (3 lusitropy, (4 exclusion of structural defects, (5 harnessing cardiopulmonary interactions, and (6 addressing metabolic and endocrine abnormalities. We have achieved a discharge survival rate of greater than 97% with these simple methods.

  18. Benefit of warm water immersion on biventricular function in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Kardassis Dimitris

    2009-07-01

    Full Text Available Abstract Background Regular physical activity and exercise are well-known cardiovascular protective factors. Many elderly patients with heart failure find it difficult to exercise on land, and hydrotherapy (training in warm water could be a more appropriate form of exercise for such patients. However, concerns have been raised about its safety. The aim of this study was to investigate, with echocardiography and Doppler, the acute effect of warm water immersion (WWI and effect of 8 weeks of hydrotherapy on biventricular function, volumes and systemic vascular resistance. A secondary aim was to observe the effect of hydrotherapy on brain natriuretic peptide (BNP. Methods Eighteen patients [age 69 ± 8 years, left ventricular ejection fraction 31 ± 9%, peakVO2 14.6 ± 4.5 mL/kg/min] were examined with echocardiography on land and in warm water (34°C. Twelve of these patients completed 8 weeks of control period followed by 8 weeks of hydrotherapy twice weekly. Results During acute WWI, cardiac output increased from 3.1 ± 0.8 to 4.2 ± 0.9 L/min, LV tissue velocity time integral from 1.2 ± 0.4 to 1.7 ± 0.5 cm and right ventricular tissue velocity time integral from 1.6 ± 0.6 to 2.5 ± 0.8 cm (land vs WWI, p There was no change in the cardiovascular response or BNP after 8 weeks of hydrotherapy. Conclusion Hydrotherapy was well tolerated by all patients. The main observed cardiac effect during acute WWI was a reduction in heart rate, which, together with a decrease in afterload, resulted in increases in systolic and diastolic biventricular function. Although 8 weeks of hydrotherapy did not improve cardiac function, our data support the concept that exercise in warm water is an acceptable regime for patients with heart failure.

  19. Angiotensin converting enzyme gene polymorphism in familial hypertrophic cardiomyopathy patients

    Energy Technology Data Exchange (ETDEWEB)

    Yu, B; Peric, S.; Ross, D. [Royal Prince Alfred Hospital, Campertown (Australia)] [and others

    1994-09-01

    An insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme (ACE) gene is a useful predictor of human plasma ACE levels. ACE levels tend to be lowest in subjects with ACE genotype DD and intermediate in subjects with ACE genotype ID. Angiotensin II (Ang II) as a product of ACE is a cardiac growth factor and produces a marked hypertrophy of the chick myocyte in cell culture. Rat experiments also suggest that a small dose of ACE inhibitor that does not affect the afterload results in prevention or regression of cardiac hypertrophy. In order to study the relationship of ACE and the severity of hypertrophy, the ACE genotype has been determined in 28 patients with a clinical diagnosis of familial hypertrophic cardiomyopathy (FHC) and 51 normal subjects. The respective frequencies of I and D alleles were: 0.52 and 0.48 (in FHC patients) and 0.44 and 0.56 (in the normal controls). There was no significant difference in the allele frequencies between FHC and normal subjects ({chi}{sup 2}=0.023, p>0.05). The II, ID, and DD genotypes were present in 7, 15, and 6 FHC patients, respectively. The averages of maximal thickness of the interventricular septum measured by echocardiography or at autopsy were 18 {plus_minus}3, 19{plus_minus}4, and 19{plus_minus}3 mm in II, ID and DD genotypes, respectively. The ACE gene polymorphism did not correlate with the severity of left ventricular hypertrophy in FHC patients (r{sub s}=0.231, p>0.05). These results do not necessarily exclude the possible effect of Ang II on the hypertrophy since the latter may be produced through the action of chymase in the human ventricles. However, ACE gene polymorphism is not a useful predictor of the severity of myocardial hypertrophy in FHC patients.

  20. Altered Right Ventricular Kinetic Energy Work Density and Viscous Energy Dissipation in Patients with Pulmonary Arterial Hypertension: A Pilot Study Using 4D Flow MRI.

    Directory of Open Access Journals (Sweden)

    Q Joyce Han

    Full Text Available Right ventricular (RV function has increasingly being recognized as an important predictor for morbidity and mortality in patients with pulmonary arterial hypertension (PAH. The increased RV after-load increase RV work in PAH. We used time-resolved 3D phase contrast MRI (4D flow MRI to derive RV kinetic energy (KE work density and energy loss in the pulmonary artery (PA to better characterize RV work in PAH patients.4D flow and standard cardiac cine images were obtained in ten functional class I/II patients with PAH and nine healthy subjects. For each individual, we calculated the RV KE work density and the amount of viscous dissipation in the PA.PAH patients had alterations in flow patterns in both the RV and the PA compared to healthy subjects. PAH subjects had significantly higher RV KE work density than healthy subjects (94.7±33.7 mJ/mL vs. 61.7±14.8 mJ/mL, p = 0.007 as well as a much greater percent PA energy loss (21.1±6.4% vs. 2.2±1.3%, p = 0.0001 throughout the cardiac cycle. RV KE work density and percent PA energy loss had mild and moderate correlations with RV ejection fraction.This study has quantified two kinetic energy metrics to assess RV function using 4D flow. RV KE work density and PA viscous energy loss not only distinguished healthy subjects from patients, but also provided distinction amongst PAH patients. These metrics hold promise as imaging markers for RV function.

  1. Long pentraxin PTX3 exacerbates pressure overload-induced left ventricular dysfunction.

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    Satoshi Suzuki

    Full Text Available BACKGROUND: Left ventricular hypertrophy is enhanced by an inflammatory state and stimulation of various cytokines. Pentraxin 3 (PTX3 is rapidly produced in response to inflammatory signals, and high plasma PTX3 levels are seen in patients with heart failure. This study aimed to examine the influence of PTX3 on cardiac hypertrophy and left ventricular dysfunction with respect to pressure overload. METHODS AND RESULTS: PTX3 systemic knockout (PTX3-KO mice, transgenic mice with cardiac-specific overexpression of PTX3 (PTX3-TG, and the respective wild-type (WT littermate mice were subjected to transverse aortic constriction (TAC or a sham operation. Cardiac PTX3 expression increased after TAC in WT mice. In vitro, hydrogen peroxide induced the expression of PTX3 in both cardiac myocytes and cardiac fibroblasts. Recombinant PTX3 phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2 in cardiac fibroblasts. Phosphorylation of cardiac ERK1/2 and nuclear factor kappa-B after TAC was attenuated in the PTX3-KO mice but was enhanced in the PTX3-TG mice compared with WT mice. Interleukin-6 and connective tissue growth factor production was lower in the PTX3-KO mice than in the WT mice, but this was augmented in the PTX3-TG mice than in the WT mice. Echocardiography revealed that adverse remodeling with left ventricular dysfunction, as well as with increased interstitial fibrosis, was enhanced in PTX3-TG mice, while these responses were suppressed in PTX3-KO mice. CONCLUSION: The local inflammatory mediator PTX3 directly modulates the hypertrophic response and ventricular dysfunction following an increased afterload.

  2. Limiting collagen turnover via collagenase-resistance attenuates right ventricular dysfunction and fibrosis in pulmonary arterial hypertension.

    Science.gov (United States)

    Golob, Mark J; Wang, Zhijie; Prostrollo, Anthony J; Hacker, Timothy A; Chesler, Naomi C

    2016-06-01

    Pulmonary arterial hypertension (PAH) is a severe form of pulmonary hypertension in which right ventricular (RV) afterload is increased and death typically occurs due to decompensated RV hypertrophy and failure. Collagen accumulation has been implicated in pulmonary artery remodeling, but how it affects RV performance remains unclear. Here, we sought to identify the role of collagen turnover, defined as the balance between collagen synthesis and degradation, in RV structure and function in PAH To do so, we exposed mutant (Col1a1(R/R)) mice, in which collagen type I degradation is impaired such that collagen turnover is reduced, and wild-type (Col1a1(+/+)) littermates to 14 days of chronic hypoxia combined with SUGEN treatment (HySu) to recapitulate characteristics of clinical PAH RV structure and function were measured by echocardiography, RV catheterization, and histology. Despite comparable increases in RV systolic pressure (Col1a1(+/+): 46 ± 2 mmHg; Col1a1(R/R): 47 ± 3 mmHg), the impaired collagen degradation in Col1a1(R/R) mice resulted in no RV collagen accumulation, limited RV hypertrophy, and maintained right ventricular-pulmonary vascular coupling with HySu exposure. The preservation of cardiac function in the mutant mice indicates a beneficial role of limited collagen turnover via impaired degradation in RV remodeling in response to chronic pressure overload. Our results suggest novel treatments that reduce collagen turnover may offer a new therapeutic strategy for PAH patients. PMID:27252252

  3. Aktuelle Entwicklungen in der Strahlentherapie des Prostatakarzinoms: HDR-Brachytherapie

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    Knocke-Abulesz TH

    2004-01-01

    Full Text Available In der primären Therapie des Prostatakarzinoms ist die Seed-Implantation neben der radikalen Prostatektomie und der konformalen 3D-geplanten Teletherapie in den letzten Jahren insbesondere bei den lokal begrenzten Tumoren die dritte etablierte Behandlungstechnik geworden. In den USA werden bereits fast ein Drittel der Patienten mit dieser Technik behandelt. Im Gegensatz hierzu wurde in der Strahlentherapie in den letzten beiden Jahrzehnten die Langzeit-Implantation von Nukliden bei den meisten Tumoren zugunsten der fraktionierten Afterloading-Bestrahlung in "high dose rate" (HDR- Technik ersetzt – wobei partiell für HNO- und gynäkologische Tumoren die HDR-Technik als "pulse-dose-rate" (PDR- Verfahren modifiziert wird, um die biologischen Vorteile der LDR- und die technologischen Vorteile der HDR-Anwendung zu vereinen. Vorteile der Methode im Vergleich zur Seed-Implantation sind: – Niedrigere Kosten, allgemeine Verfügbarkeit, – Idealer Strahlenschutz, – Zuverlässige Dosisverteilung, – Keine Migration von Seeds, – Durchführbar auch nach TURP, – Durchführbar bei manifesten Lokalrezidiven. Allerdings liegen bisher nur vereinzelte klinische Ergebnisse beim Prostatakarzinom vor, die zeigen, daß eine lokale Dosiserhöhung in Kombination mit der Teletherapie eine Verbesserung der lokalen Kontrolle bei kapselüberschreitenden Tumoren ermöglicht. Inwieweit der Einsatz der Technik bei Lokalrezidiven zu langandauernden Remissionen führen kann, ist Gegenstand von laufenden Untersuchungen. Der Ersatz der Seed-Implantation durch eine 2-tägige fraktionierte Brachytherapie mit vier Bestrahlungen ist derzeit Gegenstand einer prospektiven Studie, deren erste Langzeitergebnisse in diesem Jahr erwartet werden.

  4. Attenuated fatigue in slow twitch skeletal muscle during isotonic exercise in rats with chronic heart failure.

    Directory of Open Access Journals (Sweden)

    Morten Munkvik

    Full Text Available During isometric contractions, slow twitch soleus muscles (SOL from rats with chronic heart failure (chf are more fatigable than those of sham animals. However, a muscle normally shortens during activity and fatigue development is highly task dependent. Therefore, we examined the development of skeletal muscle fatigue during shortening (isotonic contractions in chf and sham-operated rats. Six weeks following coronary artery ligation, infarcted animals were classified as failing (chf if left ventricle end diastolic pressure was >15 mmHg. During isoflurane anaesthesia, SOL with intact blood supply was stimulated (1s on 1s off at 30 Hz for 15 min and allowed to shorten isotonically against a constant afterload. Muscle temperature was maintained at 37°C. In resting muscle, maximum isometric force (F(max and the concentrations of ATP and CrP were not different in the two groups. During stimulation, F(max and the concentrations declined in parallel sham and chf. Fatigue, which was evident as reduced shortening during stimulation, was also not different in the two groups. The isometric force decline was fitted to a bi-exponential decay equation. Both time constants increased transiently and returned to initial values after approximately 200 s of the fatigue protocol. This resulted in a transient rise in baseline tension between stimulations, although this effect which was less prominent in chf than sham. Myosin light chain 2s phosphorylation declined in both groups after 100 s of isotonic contractions, and remained at this level throughout 15 min of stimulation. In spite of higher energy demand during isotonic than isometric contractions, both shortening capacity and rate of isometric force decline were as well or better preserved in fatigued SOL from chf rats than in sham. This observation is in striking contrast to previous reports which have employed isometric contractions to induce fatigue.

  5. Malignant duodenal obstructions: palliative treatment with covered expandable nitinol stent

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Chul; Jung, Gyoo Sik; Lee, Sang Hee; Kim, Sung Min; Oh, Kyung Seung; Huh, Jin Do; Cho, Young Duk [College of Medicine, Kosin Univ, Pusan (Korea, Republic of); Song, Ho Young [College of Medicine, Ulsan Univ., Seoul (Korea, Republic of)

    2002-04-01

    To evaluate the feasibility and clinical effectiveness of using a polyurethane-covered expandable nitinol stent in the palliative treatment of malignant duodenal obstruction. Under fluoroscopic guidance, a polyurethane-covered expandable nitinol stent was placed in 12 consecutive patients with malignant duodenal obstructions. All presented with severe nausea and recurrent vomiting. The underlying causes of obstruction were duodenal carcinoma (n=4), pancreatic carcinoma (n=4), gall bladder carcinoma (n=2), distal CBD carcinoma (n=1), and uterine cervical carcinoma (n=1). The sites of obstruction were part I (n=1), part II (n=8), and III (n=3). Due to pre-existing jaundice, eight patients with part II obstructions underwent biliary decompression prior to stent placement. An introducer sheath with a 6-mm outer diameter and stents 16 mm in diameter were employed, and to place the stent, and after-loading technique was used. Stent placement was technically successful in ten patients, and no procedural complications occuured. In one of two patients in whom there was technical failure, and in whom the obstructions were located in part III, the stent was placed transgastrically. Stent migration occurred in one patient four days after the procedure, and treatment involved the palcement of a second, uncovered, nitinol stent. After stent placement, symptoms improved in all patients. During follow-up, obstructive symptoms due to stent stenosis (n=1), colonic obstruction (n=1), and multiple small bowel obstruction (n=1) recurred in three patients. Two of these were treated by placing additional stents in the duodenum and colon, respectively. One of the eight patients in whom a stent was placed in the second portion of the duodenum developed jaundice. The patients died a mean 14 (median, 9) weeks after stent placement. The placement of a polyurethane-covered expandable nitinol stent seems to be technically feasible, safe and effective for the palliative treatment of malignant

  6. Abnormal pulmonary artery stiffness in pulmonary arterial hypertension: in vivo study with intravascular ultrasound.

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    Edmund M T Lau

    Full Text Available BACKGROUND: There is increasing recognition that pulmonary artery stiffness is an important determinant of right ventricular (RV afterload in pulmonary arterial hypertension (PAH. We used intravascular ultrasound (IVUS to evaluate the mechanical properties of the elastic pulmonary arteries (PA in subjects with PAH, and assessed the effects of PAH-specific therapy on indices of arterial stiffness. METHOD: Using IVUS and simultaneous right heart catheterisation, 20 pulmonary segments in 8 PAH subjects and 12 pulmonary segments in 8 controls were studied to determine their compliance, distensibility, elastic modulus and stiffness index β. PAH subjects underwent repeat IVUS examinations after 6-months of bosentan therapy. RESULTS: AT BASELINE, PAH SUBJECTS DEMONSTRATED GREATER STIFFNESS IN ALL MEASURED INDICES COMPARED TO CONTROLS: compliance (1.50±0.11×10(-2 mm(2/mmHg vs 4.49±0.43×10(-2 mm(2/mmHg, p<0.0001, distensibility (0.32±0.03%/mmHg vs 1.18±0.13%/mmHg, p<0.0001, elastic modulus (720±64 mmHg vs 198±19 mmHg, p<0.0001, and stiffness index β (15.0±1.4 vs 11.0±0.7, p = 0.046. Strong inverse exponential associations existed between mean pulmonary artery pressure and compliance (r(2 = 0.82, p<0.0001, and also between mean PAP and distensibility (r(2 = 0.79, p = 0.002. Bosentan therapy, for 6-months, was not associated with any significant changes in all indices of PA stiffness. CONCLUSION: Increased stiffness occurs in the proximal elastic PA in patients with PAH and contributes to the pathogenesis RV failure. Bosentan therapy may not be effective at improving PA stiffness.

  7. Mechanical analysis of single myocyte contraction in a 3-D elastic matrix.

    Directory of Open Access Journals (Sweden)

    John Shaw

    Full Text Available BACKGROUND: Cardiac myocytes experience mechanical stress during each heartbeat. Excessive mechanical stresses under pathological conditions cause functional and structural remodeling that lead to heart diseases, yet the precise mechanisms are still incompletely understood. To study the cellular and molecular level mechanotransduction mechanisms, we developed a new 'cell-in-gel' experimental system to exert multiaxial (3-D stresses on a single myocyte during active contraction. METHODS: Isolated myocytes are embedded in an elastic hydrogel to simulate the mechanical environment in myocardium (afterload. When electrically stimulated, the in-gel myocyte contracts while the matrix resists shortening and broadening of the cell, exerting normal and shear stresses on the cell. Here we provide a mechanical analysis, based on the Eshelby inclusion problem, of the 3-D strain and stress inside and outside the single myocyte during contraction in an elastic matrix. RESULTS: (1 The fractional shortening of the myocyte depends on the cell's geometric dimensions and the relative stiffness of the cell to the gel. A slender or softer cell has less fractional shortening. A myocyte of typical dimensions embedded in a gel of similar elastic stiffness can contract only 20% of its load-free value. (2 The longitudinal stress inside the cell is about 15 times the transverse stress level. (3 The traction on the cell surface is highly non-uniform, with a maximum near its ends, showing 'hot spots' at the location of intercalated disks. (4 The mechanical energy expenditure of the myocyte increases with the matrix stiffness in a monotonic and nonlinear manner. CONCLUSION: Our mechanical analyses provide analytic solutions that readily lend themselves to parametric studies. The resulting 3-D mapping of the strain and stress states serve to analyze and interpret ongoing cell-in-gel experiments, and the mathematical model provides an essential tool to decipher and quantify

  8. Analysis of end-systolic pressure-volume relation by gated radionuclide angiocardiography

    International Nuclear Information System (INIS)

    Left ventricular end-systolic pressure-volume relation has been proved experimentally to b e an useful index of left ventricular contractility relatively independent of preload or afterload. But less clinical application has been reported because of its invasive nature, and we evaluated this relationship non-invasively using gated radionuclide angiocardiography as volume determination and cuff sphyngomanometer in the arm as pressure measurement. Gated equilibrium blood pool scintigrams were obtained at rest and during intravenous infusion of angiotensin or nitrate. Ventricular volumes were derived from ventricular activity and peripheral blood volume and activity. The peak systolic pressure (PSP) by cuff method to end-systolic volume index (ESVI) relations showed good linearity (r gt .930 in 84% of consecutive 50 cases) and were gentler in the groups with more impaired left ventricular function. Emax was related exponentially to ejection fraction (EF) and hyperbolically to end-diastolic volume index. The dead volume (VoI) was unfixed and fell into positive or negative value, and was not related to EF under control condition. PSP/ESVI in each loading condition was less variable with the alteration of blood pressure than EF. The linear relation was found between PSP/ESVI under control condition and Emax (PSP/ESVI = 0.651.Emax + 0.958, r = 0.841, p lt .001). Thus in measuring ventricular volume, gated radionuclide angiocardiography is a non-invasive method less affected by the geometry of the left ventricle. Non-invasive determination of end-systolic pressure-volume relation using the volume by radionuclide and the blood pressure by cuff method is clinically useful in the assessment of left ventricular contractility. (author)

  9. Myocardial energetics is not compromised during compensated hypertrophy in the Dahl salt-sensitive rat model of hypertension.

    Science.gov (United States)

    Tran, Kenneth; Han, June-Chiew; Taberner, Andrew J; Barrett, Carolyn J; Crampin, Edmund J; Loiselle, Denis S

    2016-09-01

    Salt-induced hypertension leads to development of left ventricular hypertrophy in the Dahl salt-sensitive (Dahl/SS) rat. Before progression to left ventricular failure, the heart initially undergoes a compensated hypertrophic response. We hypothesized that changes in myocardial energetics may be an early indicator of transition to failure. Dahl/SS rats and their salt-resistant consomic controls (SS-13(BN)) were placed on either a low- or high-salt diet to generate four cohorts: Dahl-SS rats on a low- (Dahl-LS) or high-salt diet (Dahl-HS), and SS-13(BN) rats on a low- (SSBN-LS) or high-salt diet (SSBN-HS). We isolated left ventricular trabeculae and characterized their mechanoenergetic performance. Our results show, at most, modest effects of salt-induced compensated hypertrophy on myocardial energetics. We found that the Dahl-HS cohort had a higher work-loop heat of activation (estimated from the intercept of the heat vs. relative afterload relationship generated from work-loop contractions) relative to the SSBN-HS cohort and a higher economy of contraction (inverse of the slope of the heat vs. active stress relation) relative to the Dahl-LS cohort. The maximum extent of shortening and maximum shortening velocity of the Dahl/SS groups were higher than those of the SS-13(BN) groups. Despite these differences, no significant effect of salt-induced hypertension was observed for either peak work output or peak mechanical efficiency during compensated hypertrophy. PMID:27402668

  10. WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

    Energy Technology Data Exchange (ETDEWEB)

    Craciunescu, O [Duke University Medical Center, Durham, NC (United States); Todor, D [Virginia Commonwealth University, Richmond, VA (United States); Leeuw, A de

    2014-06-15

    In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy.

  11. Effect of changes in intrathoracic pressure on cardiac function at rest and during moderate exercise in health and heart failure.

    Science.gov (United States)

    Lalande, Sophie; Luoma, Charles E; Miller, Andrew D; Johnson, Bruce D

    2012-02-01

    This study investigated the effect of changes in inspiratory intrathoracic pressure on stroke volume at rest and during moderate exercise in patients with heart failure and reduced ejection fraction (HFREF) as well as healthy individuals. Stroke volume was obtained by echocardiography during 2 min of spontaneous breathing (S), two progressive levels of inspiratory unloading (UL1 and UL2) using a ventilator, and two progressive levels of inspiratory loading using resistors in 11 patients with HFREF (61 ± 9 years old; ejection fraction 32 ± 4%; NYHA class I-II) and 11 age-matched healthy individuals at rest and during exercise at 60% of maximal aerobic capacity on a semi-recumbent cycle ergometer. At rest, inspiratory unloading progressively decreased stroke volume index (SVI; S, 35.2 ± 5.4 ml m(-2); UL1, 33.3 ± 5.1 ml m(-2); and UL2, 32.2 ± 4.4 ml m(-2)) in healthy individuals, while it increased SVI (S, 31.4 ± 4.6 ml m(-2); UL1, 32.0 ± 5.9 ml m(-2); and UL2, 34.0 ± 7.2 ml m(-2)) in patients with HFREF (P = 0.04). During moderate exercise, inspiratory unloading decreased SVI in a similar manner (S, 43.9 ± 7.1 ml m(-2); UL1, 40.7 ± 4.7 ml m(-2); and UL2, 39.9 ± 3.7 ml m(-1)) in healthy individuals, while it increased SVI (S, 40.8 ± 6.5 ml m(-2); UL1, 42.8 ± 6.9 ml m(-2); and UL2, 44.1 ± 4. ml m(-2)) in patients with HFREF (P = 0.02). Inspiratory loading did not significantly change SVI at rest or during moderate exercise in both groups. It is concluded that inspiratory unloading improved SVI at rest and during moderate exercise in patients with HFREF, possibly due to a reduction in left ventricular afterload.

  12. Evaluation of the asynchronization and function of the left ventricle in patients with chronic pulmonary hypertension by velocity vector imaging

    Institute of Scientific and Technical Information of China (English)

    WANG Chao-hong; WANG Yue-heng; NIU Ning-ning; XIE Ying-xin; WANG Lin

    2013-01-01

    Background Pulmonary hypertension (PH) is a set of pathophysiological syndromes characterized by increased pulmonary artery pressure and pulmonary vascular resistance,resulting in increased right ventricular afterload.The left and right ventricles interact through hemodynamics.What impact will PH have on synchronization and function of the left ventricle (LV)? The aim of this study was to evaluate the synchronization of the left ventricular wall motion and left ventricular function in patients with varying degrees of PH using velocity vector imaging (Wl) technology.Methods Sixty patients with chronic PH served as the experimental group,and 20 healthy volunteers served as the control group.According to the different degrees of pulmonary artery systolic pressure,the experimental group was divided into three groups:mild,moderate,and severe PH groups.The time to peak systolic longitudinal velocity (Tvl),the peak systolic longitudinal velocity (Vsl),the peak diastolic longitudinal velocity (Vel),the peak systolic longitudinal strain (SI),and strain rate (SRI) in 18 segments were measured in each group.Results TvI in the control group and each group with PH was reduced from basal to apical segment,and in control group Tvl in various segments of the same wall and in different walls showed no significant difference (P >0.05).With increase in pulmonary artery pressure,Tvl values measured showed an increasing trend in groups with PH.In groups with PH,Vsl and Vel of each wall were reduced sequentially from basal to apical segments,showing gradient change; Vsl and Vel values measured showed a decreasing trend with increase in pulmonary artery pressure,in which the differences of Vel values measured in the control group and the mild PH group were statistically significant (P <0.01),and the differences between other groups were statistically significant (P <0.01).In groups with PH,SI and SRI in basal segment and the middle segment of each wall were decreased; the

  13. Water equivalent phantom materials for 192Ir brachytherapy

    Science.gov (United States)

    Schoenfeld, Andreas A.; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2015-12-01

    Several solid phantom materials have been tested regarding their suitability as water substitutes for dosimetric measurements in brachytherapy with 192Ir as a typical high energy photon emitter. The radial variations of the spectral photon fluence, of the total, primary and scattered photon fluence and of the absorbed dose to water in the transversal plane of the tested cylindrical phantoms surrounding a centric and coaxially arranged Varian GammaMed afterloading 192Ir brachytherapy source were Monte-Carlo simulated in EGSnrc. The degree of water equivalence of a phantom material was evaluated by comparing the radial dose-to-water profile in the phantom material with that in water. The phantom size was varied over a large range since it influences the dose contribution by scattered photons with energies diminished by single and multiple Compton scattering. Phantom axis distances up to 10 cm were considered as clinically relevant. Scattered photons with energies reaching down into the 25 keV region dominate the photon fluence at source distances exceeding 3.5 cm. The tested phantom materials showed significant differences in the degree of water equivalence. In phantoms with radii up to 10 cm, RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR phantoms show excellent water equivalence with dose deviations from a water phantom not exceeding 0.8%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene show deviations up to 2.6%. For larger phantom radii up to 30 cm, the deviations for RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR remain below 1.4%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene produce deviations up to 8.1%. PMMA plays a separate role, with deviations up to 4.3% for radii not exceeding 10 cm, but below 1% for radii up to 30 cm. As suggested by

  14. Neurocardiogenic syncope.

    Science.gov (United States)

    Somers, V K; Abboud, F M

    1996-01-01

    Most physiologic reflex mechanisms subserve obvious and logical purposes. For example, the arterial baroreflex responds to hypotension by eliciting tachycardia and vasoconstriction, thus increasing cardiac output and raising blood pressure. The raison d'etre for a reflex such as the Bezold-Jarisch is not immediately apparent. Consider, however, the predominant stimulus for the Bezold-Jarisch reflex in the clinical context, namely, rapid forceful ventricular contraction around a relatively empty chamber. Allowing such a situation to continue would be counterproductive. Decreased diastolic filling time, regardless of ventricular contractility, would not permit any improvement in forward cardiac output and hence lead to even further hypotension and thus increasing tachycardia and adrenergic drive to the heart. The cardiac inhibitory reflex acts as a "safety valve," so to speak, slowing the heart rate, increasing diastolic filling, and decreasing afterload. This would be beneficial in myocardial infarction and aortic stenosis. In some persons, however, the reflex may be potentiated, thus predisposing to neurally mediated syncope with relatively minor provocation. We have attempted to explore the role of the cardiac inhibitory reflex in syncope associated with several clinical situations. The advent of direct measurements of sympathetic activity by microneurography, together with the availability of provocative testing such as upright tilt and programmed electrical cardiac stimulation, has provided much new insight but has also given rise to a host of additional questions. Mechanisms other than the Bezold-Jarisch reflex may be implicated. Induction of vasodepressor syncope in heart transplant recipients, as well as the association of bradycardia and syncope with partial seizures, provides some evidence that left ventricular mechanoreceptors may not be the exclusive afferent trigger for syncope and that central mechanisms may be implicated. The study of biochemical

  15. 一种植入式磁悬浮离心血泵的体外流体力学实验研究%Experimental Study of Hydrodynamic in Vitro of an Implantable Magnetic Levitation Blood Pump

    Institute of Scientific and Technical Information of China (English)

    郭龙辉; 张杰民; 赵龙; 刘晓程

    2011-01-01

    To study hydrodynamic in vitro of an implantahle magnetic levitation blood pump using vitro test loop. The fresh sheep blood was prepared for the circulating medium. The output of the pump was tested at the different speeds against 100 mmHg; by controlling the pump's speed, the output of the pump was tested against different afterload.The blood pump worked at 24 V and the electric current was 0.3-0.75 A. Power consumption of the pump was 7.2-18 W. At 2 900-3 900 rpm, the pump generated 3~7.1L/min flow against 10.0 mmHg. At 2500~3500 rpm, the pump generated 1.02~5.87 L/min flow against 69~63 mmHg. The relationship between pressure and flow was negative correlation at fixed pump's speed. The blood pump works stably in vitro test. The pump can meet the need of adult's ventricular assist, but power consumption of the pump needs further improvement.%通过体外模拟循环实验台对一种植入式磁悬浮离心血泵进行体外流体力学实验.以新鲜羊血为循环介质,通过体外循环台测定在后负荷为100 mmHg,血泵在不同转速下的输出量;通过控制血泵的转速,测定在固定泵速下不同后负荷下的输出量.血泵测试工作电压为24V,电流波动于0.3~0.75 A.血泵功率为7.2~18W.在后负荷为100 mmHg下,泵速在2 900~3 900 rpm,输出流量为3~7.1 L/min.泵速为2 500~3 500rpm,血泵在后负荷69~ 163 mmHg下输出流量为1.02 ~ 5.87 L/min.在固定的转速下血泵的压力-流量呈负相关关系.体外实验血泵工作性能稳定,可以满足成人心室辅助的需求.血泵功率偏高仍需要进一步改进.

  16. Non-invasive technology that improves cardiac function after experimental myocardial infarction: Whole Body Periodic Acceleration (pGz.

    Directory of Open Access Journals (Sweden)

    Arkady Uryash

    Full Text Available Myocardial infarction (MI may produce significant inflammatory changes and adverse ventricular remodeling leading to heart failure and premature death. Pharmacologic, stem cell transplantation, and exercise have not halted the inexorable rise in the prevalence and great economic costs of heart failure despite extensive investigations of such treatments. New therapeutic modalities are needed. Whole Body Periodic Acceleration (pGz is a non-invasive technology that increases pulsatile shear stress to the endothelium thereby producing several beneficial cardiovascular effects as demonstrated in animal models, normal humans and patients with heart disease. pGz upregulates endothelial derived nitric oxide synthase (eNOS and its phosphorylation (p-eNOS to improve myocardial function in models of myocardial stunning and preconditioning. Here we test whether pGz applied chronically after focal myocardial infarction in rats improves functional outcomes from MI. Focal MI was produced by left coronary artery ligation. One day after ligation animals were randomized to receive daily treatments of pGz for four weeks (MI-pGz or serve as controls (MI-CONT, with an additional group as non-infarction controls (Sham. Echocardiograms and invasive pressure volume loop analysis were carried out. Infarct transmurality, myocardial fibrosis, and markers of inflammatory and anti-inflammatory cytokines were determined along with protein analysis of eNOS, p-eNOS and inducible nitric oxide synthase (iNOS.At four weeks, survival was 80% in MI-pGz vs 50% in MI-CONT (p< 0.01. Ejection fraction and fractional shortening and invasive pressure volume relation indices of afterload and contractility were significantly better in MI-pGz. The latter where associated with decreased infarct transmurality and decreased fibrosis along with increased eNOS, p-eNOS. Additionally, MI-pGz had significantly lower levels of iNOS, inflammatory cytokines (IL-6, TNF-α, and higher level of anti

  17. Haemodynamics and oxygenation improvement induced by high frequency percussive ventilation in a patient with hypoxia following cardiac surgery: a case report

    Directory of Open Access Journals (Sweden)

    Persi Bruno

    2010-10-01

    did not change. Conclusion Although the high frequency percussive ventilation was started ten days after the conventional ventilation, it still improved the gas exchange. The reduction of right ventricular stroke work index, left ventricular stroke work index, pulmonary vascular resistance index and pulmonary arterial wedge pressure is directly related to the lower respiratory mean airway pressure and the consequent afterload reduction.

  18. Total aortic arch replacement: superior ventriculo-arterial coupling with decellularized allografts compared with conventional prostheses.

    Directory of Open Access Journals (Sweden)

    Alexander Weymann

    Full Text Available To date, no experimental or clinical study provides detailed analysis of vascular impedance changes after total aortic arch replacement. This study investigated ventriculoarterial coupling and vascular impedance after replacement of the aortic arch with conventional prostheses vs. decellularized allografts.After preparing decellularized aortic arch allografts, their mechanical, histological and biochemical properties were evaluated and compared to native aortic arches and conventional prostheses in vitro. In open-chest dogs, total aortic arch replacement was performed with conventional prostheses and compared to decellularized allografts (n = 5/group. Aortic flow and pressure were recorded continuously, left ventricular pressure-volume relations were measured by using a pressure-conductance catheter. From the hemodynamic variables end-systolic elastance (Ees, arterial elastance (Ea and ventriculoarterial coupling were calculated. Characteristic impedance (Z was assessed by Fourier analysis.While Ees did not differ between the groups and over time (4.1±1.19 vs. 4.58±1.39 mmHg/mL and 3.21±0.97 vs. 3.96±1.16 mmHg/mL, Ea showed a higher increase in the prosthesis group (4.01±0.67 vs. 6.18±0.20 mmHg/mL, P<0.05 in comparison to decellularized allografts (5.03±0.35 vs. 5.99±1.09 mmHg/mL. This led to impaired ventriculoarterial coupling in the prosthesis group, while it remained unchanged in the allograft group (62.5±50.9 vs. 3.9±23.4%. Z showed a strong increasing tendency in the prosthesis group and it was markedly higher after replacement when compared to decellularized allografts (44.6±8.3 dyn·sec·cm(-5 vs. 32.4±2.0 dyn·sec·cm(-5, P<0.05.Total aortic arch replacement leads to contractility-afterload mismatch by means of increased impedance and invert ventriculoarterial coupling ratio after implantation of conventional prostheses. Implantation of decellularized allografts preserves vascular impedance thereby improving

  19. The Fricke dosimeter as an absorbed dose to water primary standard for Ir-192 brachytherapy

    International Nuclear Information System (INIS)

    The aim of this project was to develop an absorbed dose to water primary standard for Ir-192 brachytherapy based on the Fricke dosimeter. To achieve this within the framework of the existing TG-43 protocol, a determination of the absorbed dose to water at the reference position, D(r0,θ0), was undertaken. Prior to this investigation, the radiation chemical yield of the ferric ions (G-value) at the Ir-192 equivalent photon energy (0.380 MeV) was established by interpolating between G-values obtained for Co-60 and 250 kV x-rays.An irradiation geometry was developed with a cylindrical holder to contain the Fricke solution and allow irradiations in a water phantom to be conducted using a standard Nucletron microSelectron V2 HDR Ir-192 afterloader. Once the geometry and holder were optimized, the dose obtained with the Fricke system was compared to the standard method used in North America, based on air-kerma strength.Initial investigations focused on reproducible positioning of the ring-shaped holder for the Fricke solution with respect to the Ir-192 source and obtaining an acceptable type A uncertainty in the optical density measurements required to yield the absorbed dose. Source positioning was found to be reproducible to better than 0.3 mm, and a careful cleaning and control procedure reduced the variation in optical density reading due to contamination of the Fricke solution by the PMMA holder. It was found that fewer than 10 irradiations were required to yield a type A standard uncertainty of less than 0.5%.Correction factors to take account of the non-water components of the geometry and the volume averaging effect of the Fricke solution volume were obtained from Monte Carlo calculations. A sensitivity analysis showed that the dependence on the input data used (e.g. interaction cross-sections) was small with a type B uncertainty for these corrections estimated to be 0.2%.The combined standard uncertainty in the determination of absorbed dose to water at

  20. Radial probe endobronchial ultrasound scanning assessing invasive depth of central lesions in tracheobronchial wall

    Institute of Scientific and Technical Information of China (English)

    LI Jing; CHEN Ping-ping; HUANG Yu; CHEN Zheng-xian

    2012-01-01

    Background Patients with central tracheobronchial benign or malignant lesions who have not recieved surgical treatment can be treated by interventional techniques,such as laser,afterloading radiotherapy,cryotherapy,photodynamics treatment,radiofrequency ablation and stenting,etc.The accuracy of the invasive depth of central lesion in tracheobronchial wall plays an important role in making interventional treatment plan.This study used radial probe endobronchial ultrasound (RP-EBUS) scanning to evaluate the accuracy of the invasive depth of central lesions in tracheobronchial wall,and the influence of RP-EBUS scanning in treatment plan making and guidance.Methods This was a prospective study of consecutive patients with central tracheobronchial lesions found by CT or bronchoscopy.We performed EBUS scanning after common bronchoscopy under local anesthesia.A radial ultrasonic probe (2.0 mm in diameter with 20-MHz frequency) with a balloon sheath was introduced through the 2.8-mm-diameter channel of a flexible bronchoscope.The balloon at the tip of the probe was inflated with distilled water until coupling with the airway wall under endoscopic control.The circular image of EBUS,which revealed the layered structure of the tracheobronchial wall,could be achieved.Results Total of 125 patients were enrolled in the study.Thirty patients underwent surgical operation and pathologically proved the RP-EBUS diagnosis accuracy of tumor invasive depth in tracheobroncial wall was 90% (27/30),sensitivity and specificity were 88.89% (24/27) and 100% (3/3),respectively.In response to EBUS images,40 approaches were altered or guided:lymph-node metastasis and compressive lesions was diagnosed by EBUS-guided transbronchial needle aspiration (TBNA) (n=8); Lesions ablation with laser or electricity were stopped when EBUS demonstrated close range with vessels or perforation possibility (n=13),stents size were changed (n=14),operation was canceled (n=3) and foreign body was removed (n=2

  1. Myocardial structure, function and ischaemic tolerance in a rodent model of obesity with insulin resistance.

    Science.gov (United States)

    Wensley, I; Salaveria, K; Bulmer, A C; Donner, D G; du Toit, E F

    2013-11-01

    Obesity and its comorbidities (dyslipidaemia, insulin resistance and hypertension) that together constitute the metabolic syndrome are all risk factors for ischaemic heart disease. Although obesity has been reported to be an independent risk factor for congestive heart failure, whether obesity-induced heart failure develops in the absence of increased afterload (induced by hypertension) is not clear. We have previously shown that obesity with insulin resistance decreases myocardial tolerance to ischaemia-reperfusion, but the mechanism for this decreased tolerance remains unclear. We hypothesize that obesity with insulin resistance induces adverse cardiac remodelling and pump dysfunction, as well as adverse changes in myocardial prosurvival reperfusion injury salvage kinase (RISK) pathway signalling to reduce myocardial tolerance to ischaemia-reperfusion. Wistar rats were fed an obesogenic (obese group) or a standard rat chow diet (control group) for 32 weeks. Echocardiography was performed over the 32 weeks before isolated Langendorff-perfused hearts were subjected to 40 min coronary artery ligation followed by reperfusion, and functional recovery (rate-pressure product), infarct size and RISK pathway function were assessed (Western blot analysis). Obesity with insulin resistance increased myocardial lipid accumulation but had no effect on in vivo or ex vivo left ventricular structure/function. Hearts from obese rats had lower reperfusion rate-pressure products (13115 ± 562 beats min(-1) mmHg for obese rats versus 17781 ± 1109 beats min(-1) mmHg for control rats, P < 0.05) and larger infarcts (36.3 ± 5.6% of area at risk in obese rats versus 14.1 ± 2.8% of area at risk in control rats, P < 0.01) compared with control hearts. These changes were associated with reductions in RISK pathway function, with 30-50 and 40-60% reductions in Akt and glycogen synthase kinase 3 beta (GSK-3β) expression and phosphorylation, respectively, in obese rat hearts compared with

  2. Current status and potential perspectives in classical radiotherapy technology

    Directory of Open Access Journals (Sweden)

    Dabić-Stanković Kata M.

    2004-01-01

    Full Text Available Introduction and potentials of classical radiotherapy After purchase of radiotherapy equipment in 2003, classic radiation therapy in Serbia will reach the highest world level. In order to define the highest standards in radiation technology, we analyzed the current status and potential perspectives of radiation therapy. Technological levels of radiotherapy in developed countries An analysis of present situation in the USA, assumed as the most developed in the world, was done. Available data, collected in the last 3 years (equipment assortment, therapy modalities, workload and manpower for 284 radiotherapy centers, out of potential 2050, were analyzed. Results were presented as crude percentage and mached to point current status. Results of analysis and discussion The analysis showed that CLINAC accelerators are the most popular (82.7%, as well as, ADAC (43.7% and Focus (CMS (27.4% systems for therapy planning. Movement towards virtual simulation is evident (59.3%, although classic ”simulation” is not fully eliminated from the radiotherapy chain. The most popular brachytherapy afterloader is Microselectron HDR (71%. About 64.4% centers use IMPAC communication/verification/record system that seems more open than Varis. All centers practice modern radiotherapy modalities and techniques (CFRT, IMRT, SRS/SRT, TBI, IORT, IVBHRT, HDR BHRT, etc.. CT and MRI availability is out of question, but PET is available in 3% of centers, however this percentage is rapidly growing. Up to 350 new patients per year are treated by one accelerator (about 35 pts. a day. Centers are relatively small and utilize 2-3 accelerators on average. Average FTE staffing norm is 4 radiation oncologists, 2-3 medical radiotherapy physicists, about 3 certified medical dosimetrists and about 6 radiotherapy technologists. Technological aspects and conclusion In the past 5 years relative stagnation in classic radiotherapy has been observed. In spite of substantial investments in

  3. High-dose rate iridium-192 brachytherapy combined with external beam radiotherapy for localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Kotaro; Inoue, Keiji; Karashima, Takashi; Inoue, Yuichiro; Kariya, Shinji; Inomata, Taisuke; Yoshida, Shoji; Shuin, Taro [Kochi Medical School, Nankoku (Japan)

    2001-07-01

    We report our technique and also preliminary results in the cases with localized prostate cancer treated by the combination of high-dose rate Iridium-192 (HDR-Ir 192) brachytherapy and external irradiation. From June 1999 to August 2000, 17 patients were treated by the combination of HDR-Ir 192 and external beam. The mean age of patients was 72 years (range, 48-81 years). The clinical stage was B1 in 5, B2 in 7 and C (no cancer with seminal vesicle) in 5 cases. Of 10 patients without neoadjuvant hormonal therapy, the median initial pretreatment PSA was 15.3 ng/ml (6.93-222.32 ng/ml). The treatment was given by HDR-Ir 192 brachytherapy (6 Gy x 3 times/2 days) and external beam irradiation (40 or 45 Gy). The brachytherapy was given using TRUS guided percutaneously inserted temporary needles with a high dose rate remote afterloading control. Local control was evaluated by digital rectal examination, TRUS-guided biopsies and serum PSA evaluations. Follow-up ranged from 2 to 14 months, with a median of 8 months. In 4 (40.0%) of 10 patients without neoadjuvant hormonal therapy the level of serum PSA was decreased to less than 4.0 ng/ml within 3 months after the therapy. The effective grade in the biopsy specimens of 8 patients without neoadjuvant hormonal therapy was Grade 0b in 4, Grade 1 in 1, Grade 3 in 3 cases at 3 months after the therapy. No severe intra-or peri-operative complications occurred. The combined radiotherapy treatment is safe and effective for use in the patients with localized prostate cancer. However, more comprehensive studies involving long-term follow-up and great numbers of the cases with localized prostate cancer treated by the combination of HDR-Ir 192 brachytherapy and external irradiation will be necessary to determine whether this therapy contributes to better prognosis. (author)

  4. Cardiac-specific genetic inhibition of nuclear factor-κB prevents right ventricular hypertrophy induced by monocrotaline.

    Science.gov (United States)

    Kumar, Sandeep; Wei, Chuanyu; Thomas, Candice M; Kim, Il-Kwon; Seqqat, Rachid; Kumar, Rajesh; Baker, Kenneth M; Jones, W Keith; Gupta, Sudhiranjan

    2012-04-15

    Uncontrolled pulmonary arterial hypertension (PAH) results in right ventricular (RV) hypertrophy (RVH), progressive RV failure, and low cardiac output leading to increased morbidity and mortality (McLaughlin VV, Archer SL, Badesch DB, Barst RJ, Farber HW, Lindner JR, Mathier MA, McGoon MD, Park MH, Rosenson RS, Rubin LJ, Tapson VF, Varga J. J Am Coll Cardiol 53: 1573-1619, 2009). Although the exact figures of its prevalence are difficult to obtain because of the diversity of identifiable causes, it is estimated that the incidence of pulmonary hypertension is seven to nine cases per million persons in the general population and is most prevalent in the age group of 20-40, occurring more commonly in women than in men (ratio: 1.7 to 1; Rubin LJ. N Engl J Med 336: 111-117, 1997). PAH is characterized by dyspnea, chest pain, and syncope. Unfortunately, there is no cure for this disease and medical regimens are limited (Simon MA. Curr Opin Crit Care 16: 237-243, 2010). PAH leads to adverse remodeling that results in RVH, progressive right heart failure, low cardiac output, and ultimately death if left untreated (Humbert M, Morrell NW, Archer SL, Stenmark KR, MacLean MR, Lang IM, Christman BW, Weir EK, Eickelberg O, Voelkel NF, Rabinovitch M. J Am Coll Cardiol 43: 13S-24S, 2004; Humbert M, Sitbon O, Simonneau G. N Engl J Med 351: 1425-1436, 2004. LaRaia AV, Waxman AB. South Med J 100: 393-399, 2007). As there are no direct tools to assess the onset and progression of PAH and RVH, the disease is often detected in later stages marked by full-blown RVH, with the outcome predominantly determined by the level of increased afterload (D'Alonzo GE, Barst RJ, Ayres SM, Bergofsky EH, Brundage BH, Detre KM, Fishman AP, Goldring RM, Groves BM, Kernis JT, et al. Ann Intern Med 115: 343-349, 1991; Sandoval J, Bauerle O, Palomar A, Gomez A, Martinez-Guerra ML, Beltran M, Guerrero ML. Validation of a prognostic equation Circulation 89: 1733-1744, 1994). Various studies have been

  5. Assessment of right ventricular function by pressure-volume loops in off-pump coronary artery bypass surgery

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-wei; YUE Yun; WU An-shi; LIU Yu; RUI Yan; WU Di; LIU Juan; ZHAO Qiu-hua; GUO Shu-rong; ZHANG Yong-qian

    2008-01-01

    anastomoses (T2-T4, P<0.05), whereas EED increased throughout OPCAB surgery (P<0.05).Conclusions Right ventricular pressure-volume loops can be constructed using a volumetric PAC. Right ventricular systolic dysfunction occurred during anastomoses on the heart's posterior wall not due to impaired myocardial contractility but as a result of reduced preload and a relative increase in afterload. Right ventricular diastolic function was impaired throughout OPCAB surgery.

  6. ENT COBRA (Consortium for Brachytherapy Data Analysis): interdisciplinary standardized data collection system for head and neck patients treated with interventional radiotherapy (brachytherapy)

    Science.gov (United States)

    Tagliaferri, Luca; Kovács, György; Budrukkar, Ashwini; Guinot, Jose Luis; Hildebrand, Guido; Johansson, Bengt; Monge, Rafael Martìnez; Meyer, Jens E.; Niehoff, Peter; Rovirosa, Angeles; Takàcsi-Nagy, Zoltàn; Dinapoli, Nicola; Lanzotti, Vito; Damiani, Andrea; Soror, Tamer; Valentini, Vincenzo

    2016-01-01

    Purpose Aim of the COBRA (Consortium for Brachytherapy Data Analysis) project is to create a multicenter group (consortium) and a web-based system for standardized data collection. Material and methods GEC-ESTRO (Groupe Européen de Curiethérapie – European Society for Radiotherapy & Oncology) Head and Neck (H&N) Working Group participated in the project and in the implementation of the consortium agreement, the ontology (data-set) and the necessary COBRA software services as well as the peer reviewing of the general anatomic site-specific COBRA protocol. The ontology was defined by a multicenter task-group. Results Eleven centers from 6 countries signed an agreement and the consortium approved the ontology. We identified 3 tiers for the data set: Registry (epidemiology analysis), Procedures (prediction models and DSS), and Research (radiomics). The COBRA-Storage System (C-SS) is not time-consuming as, thanks to the use of “brokers”, data can be extracted directly from the single center's storage systems through a connection with “structured query language database” (SQL-DB), Microsoft Access®, FileMaker Pro®, or Microsoft Excel®. The system is also structured to perform automatic archiving directly from the treatment planning system or afterloading machine. The architecture is based on the concept of “on-purpose data projection”. The C-SS architecture is privacy protecting because it will never make visible data that could identify an individual patient. This C-SS can also benefit from the so called “distributed learning” approaches, in which data never leave the collecting institution, while learning algorithms and proposed predictive models are commonly shared. Conclusions Setting up a consortium is a feasible and practicable tool in the creation of an international and multi-system data sharing system. COBRA C-SS seems to be well accepted by all involved parties, primarily because it does not influence the center's own data storing

  7. The long term effects of high dose rate brachytherapy on neointimal hyperplasia formation in the rat carotid artery - an update

    International Nuclear Information System (INIS)

    Purpose/Objective: A large number of investigators have begun utilizing radiation modalities in order to prevent or delay neointimal hyperplasia (NIH) formation. Following our initial successful studies looking at single fraction low doses of HDR brachytherapy given immediately after injury, we extended this model to look at the long term effects on the inhibition of NIH in the rat common carotid artery. Materials and Methods: The right common carotid arteries (CCA) of 4-5 month old male Sprague Dawley rats were injured using a 2F balloon catheter. Immediately post-injury, a delivery catheter was sutured alongside the injured artery and the vessel received either 0, 5, or 10 Gy irradiation using an Iridium 192 afterloader. Six months post-treatment, the animals were sacrificed and both the right and left CCA were harvested following perfusion fixation, and processed for light and electron micrography. Specimens were stained with PAS and the intima and media areas were calculated using a computer-assisted digitizing program. Additional immunocytochemical staining was carried out, looking particularly at PDGF. Results: In contrast to our previous findings which were assessed at 3 weeks post-treatment, at the later time point of 6 months post-treatment, there was no significant reduction in intimal area of the radiation-treated balloon-injured animals compared to the balloon-injured alone and the intima: media ratios was the same in both groups (Fig. 1). The lumenal area in both treatment groups was significantly reduced from normal controls (Fig. 2). Immunocytochemical staining for PDGF at 3 weeks demonstrated that there was an immediate (24 hours) release of growth factor from the medial smooth muscle in the balloon-injured animals; there was no similar release in the radiation-treated animals at the 1 day, 1 or 3 week time points. This will now be assessed at the later time points. Higher doses of 15-25 Gy are now being studied since other investigators have shown

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

    Energy Technology Data Exchange (ETDEWEB)

    Urakami, Shinji; Gonda, Nobuko; Kikuno, Nobuyuki [Shimane Medical Univ., Izumo (Japan)] (and others)

    2001-05-01

    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

  9. Intraoperative radiotherapy (IORT combined with external beam radiotherapy (EBRT for soft-tissue sarcomas – a retrospective evaluation of the Homburg experience in the years 1995–2007

    Directory of Open Access Journals (Sweden)

    Bleuzen Caroline

    2009-08-01

    Full Text Available Abstract Purpose To retrospectively evaluate the results after a regimen of surgery, IORT (intraoperative radiotherapy, and EBRT (external beam radiotherapy for soft-tissue sarcomas Methods 38 consecutive patients underwent IORT for soft-tissue sarcoma; 29 were treated for primary tumours, 9 for recurrences. There were 14 cases with liposarcomas, 8 with leiomyosarcomas, 7 with malignant fibrous histiocytomas. 27/38 tumours were located in the extremities, the remaining ones in the retroperitoneum or the chest. Radical resection was attempted in all patients; a R0-resection was achieved in 15/38 patients, R1 in 12/38 pats and R2 in 4/38 pats. IORT was performed using a J-125 source and a HDR (high dose rate afterloading machine after suturing silicone flaps to the tumour bed. The total dose applied ranged from 8–15 Gy/0.5 cm tissue depth measured from the flap surface. After wound healing external beam radiotherapy (EBRT was applied in 31/38 patients with total doses of 23–56 Gy dependent on resection status and wound situation. The mean duration of follow-up was 2.3 years. Results A local recurrence was found in 10/36 patients, lymph node metastases in 2/35, and distant metastases in 6/35 patients. The actuarial local control rate was 63%/5 years. The overall survival rate was 57%/5 years. There was no statistically significant difference between the results after treatment for primaries or for recurrences. Late toxicity to the skin was found in 13/31 patients, wound healing problems in 5/31 patients. A neuropathy was never seen. Conclusion The combination of surgery, IORT, and EBRT yields favourable local control and survival data which are well within the range of the results reported in the literature. The complication rates, however, are considerable although the complications are not severe, they should be taken into account when therapy decisions are made.

  10. Observation of hyperfractional integrated intracavitary brachytherapy on efficacy and complications in patients with middle and advanced squamous cell carcinoma of the cervix

    International Nuclear Information System (INIS)

    Objective: To observe and compare the efficacy and complications of hyperfractional integrated intracavitary brachtherapy in middle-advanced squamous-cell carcinoma with the traditional brachytherapy. Methods: In the observed group, 328 patients with cervical cancer received hyperfractional integrated intracavitary after loading therapy between Jan 2004 and Jan 2005 were selected. The dose of point A was 2.5 Gy-3.0 Gy/fraction, 2 fractions per week, and the total dose of reference point A was 49.8 Gy in stage IIb, 52.6 Gy in stage IIIb. In the control group, 331 cases treated with traditional afterloading brachytherapy between Jan 2002 and Dec 2003 were selected. The dose of point A was 5.0∼7.0 Gy/fraction, 1 fraction per week, and the total dose of point A was 50.1 Gy in stage IIb, 53.5 Gy in stage IIIb, In vitro irradiation began at the same time with the intracavitary brachytherapy. The whole pelvic was irradiated with 15 MV X-rays. Results: In the observed group, the recent control rate of stage IIb was 97.2% (104/107), 94.1% (208/221) for stage IIIb. The 3- year survival rate was 80.5% (264/328), and the 5-year survival rate was 68.6% (225/328). The complication rate was 5.2% (17/328) for cystitis, 14.6% (48/328) for proctitis. Out of 331 cases in control group, the recent control rate of stage IIb was 95.4% (103/108), 92.8% (207/223) for stage IIIb. The 3-year survival rate was 75.2% (249/332), the 5-year survival rate was 62.5% (207/331). The complication rate was 13.3% (44/331) for cystitis, and 32.3% (107/331) for proctitis. Conclusions: Compared with combination of traditional brachytherapy and external radiotherapy, combination of hyperfractional integrated brachtherapy therapy and external radiotherapy has no significant improvement for recent control rate and long-term survival rate, but could reduce the complication rates of cystitis and proctitis. (authors)

  11. Clinical experience with the MammoSite[reg] radiation therapy system for brachytherapy of breast cancer: Results from an international phase II trial

    International Nuclear Information System (INIS)

    Background and purpose: In a prospective multi-center phase II trial, we investigated the MammoSite[reg] Radiation Therapy System, a new device for delivering intracavitary brachytherapy following breast conserving surgery. The MammoSite[reg] is a dual lumen, closed ended catheter with a small, spherical inflatable balloon and a port for connecting a remote afterloader to the central lumen. We analyzed the surgical procedure and placement of the MammoSite[reg], treatment planning and radiation delivery complications and cosmesis, as well the comfort for the patients. Patients and methods: Between 2002 and 2004 a total of 32 patients (pts) were implanted using the MammoSite[reg]. The reference isodose was defined 1 cm from the balloon surface. We analyzed the post-implant anatomic position of the applicator and the geometric form of the balloon via ultrasound, CT and X-ray, related side effects, cosmetic outcome and patient quality of life. Results: Twenty-three out of 32 patients (72%) were eligible for MammoSite[reg] intracavitary brachytherapy. Twenty-eight percentage had to be excluded because of different reasons. Eleven patients were treated with primary brachytherapy with a total dose of 34 Gy (2x3.4 Gy) and 12 had a boost with a mean dose of 13.3 Gy (range: 7.5-15 Gy; 2x2.5 Gy) combined with EBRT and doses ranged between 46 and 50 Gy. In three cases a balloon rupture occurred. We observed two abscesses within 3 months of implantation and serious seroma development in 10 patients (39%). Skin related side effects were erythema in 21 patients (91%), hyperpigmentation in 13 patients (56%) and teleangiectasia in six patients (26%) after mean follow-up 20 months. Conclusions: The MammoSite[reg] Radiation Therapy System is a feasible treatment modality for intracavitary brachytherapy of breast cancer after breast conserving surgery. The advantage of the system is only one applicator is necessary for the delivery of a fractionated radiotherapy. In addition, patient

  12. Water equivalent phantom materials for (192)Ir brachytherapy.

    Science.gov (United States)

    Schoenfeld, Andreas A; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2015-12-21

    Several solid phantom materials have been tested regarding their suitability as water substitutes for dosimetric measurements in brachytherapy with (192)Ir as a typical high energy photon emitter. The radial variations of the spectral photon fluence, of the total, primary and scattered photon fluence and of the absorbed dose to water in the transversal plane of the tested cylindrical phantoms surrounding a centric and coaxially arranged Varian GammaMed afterloading (192)Ir brachytherapy source were Monte-Carlo simulated in EGSnrc. The degree of water equivalence of a phantom material was evaluated by comparing the radial dose-to-water profile in the phantom material with that in water. The phantom size was varied over a large range since it influences the dose contribution by scattered photons with energies diminished by single and multiple Compton scattering. Phantom axis distances up to 10 cm were considered as clinically relevant. Scattered photons with energies reaching down into the 25 keV region dominate the photon fluence at source distances exceeding 3.5 cm.The tested phantom materials showed significant differences in the degree of water equivalence. In phantoms with radii up to 10 cm, RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR phantoms show excellent water equivalence with dose deviations from a water phantom not exceeding 0.8%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene show deviations up to 2.6%. For larger phantom radii up to 30 cm, the deviations for RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR remain below 1.4%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene produce deviations up to 8.1%. PMMA plays a separate role, with deviations up to 4.3% for radii not exceeding 10 cm, but below 1% for radii up to 30 cm.As suggested

  13. Role of permissive hypotension, hypertonic resuscitation and the global increased permeability syndrome in patients with severe hemorrhage: adjuncts to damage control resuscitation to prevent intra-abdominal hypertension.

    Science.gov (United States)

    Duchesne, Juan C; Kaplan, Lewis J; Balogh, Zsolt J; Malbrain, Manu L N G

    2015-01-01

    Secondary intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are closely related to fluid resuscitation. IAH causes major deterioration of the cardiac function by affecting preload, contractility and afterload. The aim of this review is to discuss the different interactions between IAH, ACS and resuscitation, and to explore a new hypothesis with regard to damage control resuscitation, permissive hypotension and global increased permeability syndrome. Review of the relevant literature via PubMed search. The recognition of the association between the development of ACS and resuscitation urged the need for new approach in traumatic shock management. Over a decade after wide spread application of damage control surgery damage control resuscitation was developed. DCR differs from previous resuscitation approaches by attempting an earlier and more aggressive correction of coagulopathy, as well as metabolic derangements like acidosis and hypothermia, often referred to as the 'deadly triad' or the 'bloody vicious cycle'. Permissive hypotension involves keeping the blood pressure low enough to avoid exacerbating uncontrolled haemorrhage while maintaining perfusion to vital end organs. The potential detrimental mechanisms of early, aggressive crystalloid resuscitation have been described. Limitation of fluid intake by using colloids, hypertonic saline (HTS) or hyperoncotic albumin solutions have been associated with favourable effects. HTS allows not only for rapid restoration of circulating intravascular volume with less administered fluid, but also attenuates post-injury oedema at the microcirculatory level and may improve microvascular perfusion. Capillary leak represents the maladaptive, often excessive, and undesirable loss of fluid and electrolytes with or without protein into the interstitium that generates oedema. The global increased permeability syndrome (GIPS) has been articulated in patients with persistent systemic inflammation failing

  14. Hypertonic saline.

    Science.gov (United States)

    Constable, P D

    1999-11-01

    A key feature in the successful resuscitation of dehydrated or endotoxemic ruminants is the total amount of sodium administered. Administration of small volumes of HS and HSD offer major advantages over large volumes of isotonic saline because HS and HSD do not require intravenous catheterization or periodic monitoring, and are therefore suitable for use in the field. Hypertonic saline and HSD exert their beneficial effect by rapidly increasing preload and transiently decreasing afterload. Contrary to early reports, HS and HSD decrease cardiac contractility and do not activate a pulmonary reflex. The osmolality of HS and HSD should be 2400 mOsm/L (7.2% NaCl solution, 8 times normal plasma osmolality). Use of HS and HSD solutions of different osmolality to 2400 mOsm/L should be avoided at all costs, as too low a tonicity removes the main advantages of HS (low cost, decreased infusion time), whereas too high a tonicity may cause rapid vasodilation and decreased cardiac contractility, resulting in death. Rapid administration (> 1 mL/kg-1/min-1) of HS (2400 mOsm/L) should be avoided, as the induced hypotension may be fatal when coupled with a transient decrease in cardiac contractility. For treating dehydrated adult ruminants, HS (2400 mOsm/L, 4-5 mL/kg i.v. over 4-5 minutes) should be administered through the jugular vein and the cow allowed to drink water. This means that 2 L of HS should be administered to adult cattle. HSD should be administered in conjunction with isotonic oral electrolyte solutions to all calves 8% or more dehydrated (eyes recessed > or = 4 mm into the orbit, cervical skin tent duration > 6 seconds) or calves with reduced cardiac output (fetlock temperature isotonic oral electrolyte solution. This means that 120-200 mL of HSD of HSD should be administered to a calf. HSD should be routinely administered to severely depressed or comatose calves, as HSD provides the fastest method of resuscitation while rapidly reversing the effects of hyperkalemia

  15. Initial hydrodynamic study on a new intraaortic axial flow pump: Dynamic aortic valve

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Rotary blood pumps have been researched as implantableventricular assist devices for years. To further reduce the complex of implanted axial pumps, the authors proposed a new concept of intraaortic axial pump, termed previously as "dynamic aortic valve (DAV)". Instead of being driven by an intraaortic micro-electric motor, it was powered by a magnetic field from outside of body. To ensure the perfusion of coronary artery, the axial flow pump is to be implanted in the position of aortic valve. It could serve as either a blood pump or a mechanical valve depending on the power input. This research tested the feasibility of the new concept in model study. A column, made from permanent magnet, is jointed to an impeller in a concentric way to form a "rotor-impeller". Supported by a hanging shaft cantilevered in the center of a rigid cage, the rotor-impeller can be turned by the magnetic field in the surrounding space. In the present prototype, the rotor is 8 mm in diameter and 15 mm in length, the impeller has 3 vanes with an outer diameter of 18 mm. The supporting cage is 22 mm in outer diameter and 20 mm in length. When tested, the DAV prototype is inserted into the tube of a mock circuit. The alternative magnetic field is produced by a rotating magnet placed side by side with the rotor-impeller at a distance of 30 mm. Once the alternative magnetic field is presented in the surrounding space, the DAV starts to turn, leading to a pressure difference and liquid flow in the tube. The flow rate or pressure difference is proportioned to rotary speed. At the maximal output of hydraulic power, the flow rate reached 5 L/min against an afterload of 100 mmHg. The maximal pressure difference generated by DAV at a rotation rate of 12600 r/min was 147 mmHg. The preliminary results demonstrated the feasibility of "DAV", further research on this concept is justifiable.

  16. Non-invasive estimation of myocardial efficiency using positron emission tomography and carbon-11 acetate--comparison between the normal and failing human heart.

    Science.gov (United States)

    Bengel, F M; Permanetter, B; Ungerer, M; Nekolla, S; Schwaiger, M

    2000-03-01

    The clearance kinetics of carbon-11 acetate, assessed by positron emission tomography (PET), can be combined with measurements of ventricular function for non-invasive estimation of myocardial oxygen consumption and efficiency. In the present study, this approach was applied to gain further insights into alterations in the failing heart by comparison with results obtained in normals. We studied ten patients with idiopathic dilated cardiomyopathy (DCM) and 11 healthy normals by dynamic PET with 11C-acetate and either tomographic radionuclide ventriculography or cine magnetic resonance imaging. A "stroke work index" (SWI) was calculated by: SWI = systolic blood pressure x stroke volume/body surface area. To estimate myocardial efficiency, a "work-metabolic index" (WMI) was then obtained as follows: WMI = SWI x heart rate/k(mono), where k(mono) is the washout constant for 11C-acetate derived from monoexponential fitting. In DCM patients, left ventricular ejection fraction was 19%+/-10% and end-diastolic volume was 92+/-28 ml/m2 (vs 64%+/-7% and 55+/-8 ml/m2 in normals, PSWI (1674+/-761 vs 4736+/-895 mmHg x ml/m2; P<0.001) and the WMI as an estimate of efficiency (2.98+/-1.30 vs 6.20+/-2.25 x 10(6) mmHg x ml/m2; P<0.001) were lower in DCM patients, too. Overall, the WMI correlated positively with ejection parameters (r=0.73, P<0.001 for ejection fraction; r=0.93, P<0.001 for stroke volume), and inversely with systemic vascular resistance (r=-0.77; P<0.001). There was a weak positive correlation between WMI and end-diastolic volume in normals (r=0.45; P=0.17), while in DCM patients, a non-significant negative correlation coefficient (r=-0.21; P=0.57) was obtained. In conclusion non-invasive estimates of oxygen consumption and efficiency in the failing heart were reduced compared with those in normals. Estimates of efficiency increased with increasing contractile performance, and decreased with increasing ventricular afterload. In contrast to normals, the failing heart

  17. Californium-252 Neutron Therapy in China

    International Nuclear Information System (INIS)

    Californium-252 brachytherapy, believed to be the most successful source for neutron therapy, gives most of the cures as well as long-term and complication-free survivals. Chinese radiation oncologists were interested in californium neutron therapy (Cf-NT) in the early 1980s, but 252Cf sources for medical use were not available in China until 1992 when a californium joint venture was established by the China Institute of Atomic Energy (Beijing) and the Research Institute for Nuclear Reactors (Dimitrovgrad) of Russia. In 1995, 25 seeds of 252Cf with a strength of 3 μg each were sent to China for preclinical investigation. Three years later, a high dose rate (HDR) 252Cf source was imported and transferred into a home-made remote after-loader for intracavitary treatment in Chongqing, and a clinical trail was started in February 1999. This is the first time that Cf-NT was performed for cancer patients in China. Since then, Cf-NT in China has developed rapidly. It is estimated that one-tenth of those radiation oncology centers with brachytherapy practice will be equipped with californium units in 5 yr. That means more than 30 units will be in use in hospitals. That is significant compared with other countries, but it is just one, on average, for each province or one per 40 million people in China. Progress also has been achieved in the 252Cf treatment delivery equipment. Preliminary clinical trails showed complete response observed in all cases treated, with a rapid clearance of tumors and mild reactions in normal tissues. The short-term results are quite encouraging. To deal with problems due to the demand for Cf-NT in China, attention should be paid to the following particulars: (1) A high-strength miniature source is needed for HDR/MDR interstitial therapy to extend the Cf-NT coverage. (2) Basic work on radiophysics and radiobiology needs to be done, including source calibration, clinical dosimetry, clinical RBE determination, and Cf-NT quality assurance

  18. ME 04-3 EPIDEMIOLOGY AND CONSEQUENCES OF EARLY VASCULAR AGING.

    Science.gov (United States)

    Hashimoto, Junichiro

    2016-09-01

    Arterial structure and function change progressively with advancing age. Owing to long-lasting repetitive stretch with intermittent cardiac contraction, elastic fibers in the tunica media of large arteries gradually degenerate and are replaced by collagenous fibers. Such medial degeneration causes elastic arteries to stiffen and dilate. However, the speed of the vascular aging varies considerably among individuals; a discrepancy often exists between the chronological age of an individual and the biological age of his or her arteries. In susceptible individuals the vascular aging process can be accelerated under the presence of various risk factors including hypertension, smoking, metabolic disorders, high sodium intake and hereditary traits. Early vascular aging is generally detected by vascular function tests such as pulse wave velocity (PWV) and pulse wave analysis. Stiffening of large elastic arteries increases the PWV, increases the amplitude of the incident pressure wave, and hastens the return of the reflected pressure wave. Consequent widening of the aortic pulse pressure elevates left ventricular afterload during systole and reduces coronary flow during diastole, thus predisposing to heart failure and myocardial ischemia. The excessive pulsatile pressure is also transmitted into the vulnerable microvasculature in the kidney and brain to cause albuminuria and lacunar infarction. Furthermore, aortic stiffening increases blood flow reversal in early diastole in the proximal descending aorta. The increased aortic flow reversal reduces renal blood flow and glomerular filtration rate, and in addition, it raises the risk of retrograde cerebral embolism of aortic mobile plaques. Such deleterious impacts of the central hemodynamic abnormalities on the vital end-organs predispose the patients with early vascular aging to premature cardiovascular diseases. Indeed, epidemiological prospective studies have demonstrated that aortic PWV and central hemodynamic indices

  19. High dose rate brachytherapy using custom made superficial mould applicators and Leipzig applicators for non melanoma localized skin cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, A. Cassio A.; Miziara, Daniela; Lima, Flavia Pedroso de; Miziara, Miguel

    2014-07-01

    Purpose: advances in technology and the commercial production of Leipzig applicators allowed High Dose Rate after-load brachytherapy (HDR-BT) to address a number of the challenges associated with the delivery of superficial radiation to treat localized non melanoma skin cancer (NMSK). We reviewed our uni-institutional experience on the treatment of NMSK with HDR-BT. Methods: data were collected retrospectively from patients attending the Radiation Oncology Department at AV Carvalho Insitute, Sao Paulo, Brazil. HDR-BT was done using the stepping source HDR 192Ir Microselectron (Nucletron BV). The planning target volume consisted of the macroscopic lesion plus a 5mm to 10mm margin.The depth of treatment was 0.5 cm in smaller (< 2.0 cm) tumors and 10 to 15 mm for lesions bigger than that. Results: Thirteen patients were treated with HDR-BT from June, 2007 to June 2013. The median age and follow up time were 72 (38-90) years old and 36 (range, 7-73) months, respectively. There a predominance of males (61.5%) and of patients referred for adjuvant treatment due positive surgical margins or because they have had only a excision biopsy without safety margins (61.5%). Six (46.2%) patients presented with squamous cell carcinoma and 7 (53.8%) patients presented with basal cell carcinoma. The median tumor size was 20 (range, 5-42) mm. Patients were treated with a median total dose of 40 Gy (range, 20 -60), given in 10 (range, 2-15) fractions, given daily or twice a week. All patients responded very well to treatment and only one patient has failed locally so far, after 38 months of the end of the irradiation. The crude and actuarial 3-year local control rates were 100% and 80%, respectively. Moist desquamation, grade 2 RTOG, was observed in 4 (30.8%) patients. Severe late complication, radiation-induced dyspigmentation, occurred in 2 patients and 1 of the patients also showed telangiectasia in the irradiated area. The cosmetic result was considered good in 84% (11/13) patients

  20. Fiber-coupled radioluminescence dosimetry with saturated Al{sub 2}O{sub 3}:C crystals: Characterization in 6 and 18 MV photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, C.E., E-mail: clan@risoe.dtu.dk [Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde (Denmark); Damkjaer, S.M.S.; Kertzscher, G. [Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde (Denmark); Greilich, S. [Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), D-69120 Heidelberg (Germany); Aznar, M.C. [Department of Radiation Oncology, Copenhagen University Hospital, DK-2100 Copenhagen (Denmark)

    2011-10-15

    Radioluminescence (RL) and optically stimulated luminescence (OSL) from carbon-doped aluminum oxide crystals can be used for medical dosimetry in external beam radiotherapy and remotely afterloaded brachytherapy. The RL/OSL signals are guided from the treatment room to the readout instrumentation using optical fiber cables, and in vivo dosimetry can be carried out in real time while the dosimeter probes are in the patient. The present study proposes a new improved readout protocol based solely on the RL signal from Al{sub 2}O{sub 3}:C. The key elements in the protocol are that Al{sub 2}O{sub 3}:C is pre-dosed with {approx}20 Gy before each measurement session, and that the crystals are not perturbed by optical stimulation. Using 6 and 18 MV linear accelerator photon beams, the new RL protocol was found to have a linear dose-response from 7 mGy to 14 Gy, and dosimetry in this range could therefore be performed using a single calibration factor ({approx}6 x 10{sup 6} counts per Gy for a 2 mg crystal). The reproducibility of the RL dosimetry was 0.3% (one relative standard deviation) for doses larger than 0.1 Gy. The apparent RL sensitivity was found to change with accumulated dose ((-0.45 {+-} 0.03)% per 100 Gy), crystal temperature ((-0.21 {+-} 0.01)%/ deg. C), and dose-delivery rate ((-0.22 {+-} 0.01)% per 100 MU/min). A temporal gating technique was used for separation of RL and stem signals (i.e. Cerenkov light and fluorescence induced in the optical fiber cable during irradiation). The new readout protocol was a substantial improvement compared with the combined RL/OSL protocol, that required relatively long readout times and where the optical stimulation greatly affected the RL sensitivity. The only significant caveat was the apparent change in RL-response with accelerator dose-delivery rate. - Highlights: > New readout protocol based only on the RL signal from pre-dosed Al{sub 2}O{sub 3}:C. > Fast readout. > Linear dose-response. > High-dynamic range (7 mGy-14

  1. Chemoradiation in cervical cancer with cisplatin and high-dose rate brachytherapy combined with external beam radiotherapy. Results of a phase-II study

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, H.G.; Laban, C.; Puschmann, D.; Koelbl, H. [Dept. of Gynecology, Martin-Luther Univ. Halle-Wittenberg (Germany); Kuhnt, T.; Pigorsch, S.; Dunst, J.; Haensgen, G. [Dept. of Radiotherapy, Martin-Luther Univ. Halle-Wittenberg (Germany)

    2002-07-01

    chemoradiation with cisplatin 40 mg/m{sup 2} weekly x 6 using HDR brachytherapy represents a promising treatment of cervical cancer with an acceptable toxicity. (orig.) [German] Hintergrund: 1999 zeigten fuenf randomisierte Studien, dass die simultane Radiochemotherapie mit Cisplatin und einer Low-Dose-Rate-Brachytherapie fuer Patientinnen mit einem lokal fortgeschrittenen Zervixkarzinom und in der adjuventen Hochrisikosituation einen Ueberlebensvorteil bringt. Wir untersuchten die Sicherheit und Effektivitaet der simultanen Radiochemotherapie mit Cisplatin und High-Dose-Rate-Brachytherapie bei diesen Patientinnen. Patientinnen und Methode: 27 Patientinnen wurden in unserer Phase-II-Studie eingeschlossen: 13 mit lokal fortgeschrittenen Zervixkarzinomen (Gruppe A) und 14 adjuvante Hochrisikopatientinnen (Gruppe B). Die primaer radiochemotherapierten Faelle erhielten 25 Fraktionen einer perktuanen Hochvolttherapie des Beckens (1,8 Gy pro Fraktion/Einbringen eines Mittelblocks nach elf Fraktionen). Die Brachytherapie wurde bei den FIGO-Stadien IIB-IIIB nach dem High-Dose-Rate-Afterloading-Prinzip mit 7 Gy pro Fraktion in Punkt A (Gesamtdosis 35 Gy) appliziert. Die Gesamtdosis der kombinierten Therapie war 70 Gy in Punkt A und 52-54 Gy in Punkt B. Bei den FIGO-Stadien IVA erfolgte keine Brachyhtherapie. Bei der adjuvanten Strahlentherapie wurde die perkutane Hochvolttherapie des Beckens mit Fraktionen von 1,8 Gy bis zu einer Gesamtdosis von 50,4 Gy appliziert. Die High-Dose-Rate-Afterloading-Brachytherapie mit zwei Fraktionen von 5 Gy erfolgte nur bei Patientinnen, bei denen sich im Operationspraeparat tumorbefallene Resektionsraender oder ein Befall der Scheide fanden. Das Chemotherapieregime mit 6 woechentlichen Gaben von 40 mg/m{sup 2} Cisplatin entsprach dem der Studien 120 und 123 der GOG. Ergebnisse: 18 von 27 Patientinnen (66,7%) erhielten alle sechs Cisplatingaben. Eine Unterbrechung der Strahlentherapie aufgrund von Nebenwirkungen war in keinem Fall erforderlich. Die G3

  2. Study of hydrodynamic in vitro and animal experiment of a homebred pneumatic pulsatile ventricular assist device%国产气动搏动性心室辅助装置的体外流体力学及动物实验观察

    Institute of Scientific and Technical Information of China (English)

    史国宁; 陈庆良; 陈彤云; 刘建实

    2015-01-01

    目的:对我国自主研发气动搏动性心室辅助装置进行体外流体力学检验及活体动物应用实验,检验其是否满足临床心室辅助装置要求。方法通过体外模拟循环实验台,30%甘油水溶液作为循环介质,接入心室辅助装置,测定不同模式下血泵的后负荷和流量,以此检测装置的流体力学效果。对6只实验犬应用心室辅助装置左心辅助模式1 h,之后药物KCl诱颤心脏,5 min后除颤。监测心室辅助装置对实验犬的心率、血压支持效果。结果心室辅助装置流体力学实验后负荷100 mmHg条件下,流量可达到4 L/min以上。实验犬经左室安装辅助装置后,各时间点心率无明显变化。辅助后即刻与辅助前相比收缩压升高约30 mmHg,舒张压升高约19 mmHg。辅助过程中未见明显血压波动。诱颤后可维持收缩压60 mmHg,除颤后撤除装置存活良好。结论该心室辅助装置所产生的流体压力可基本满足临床心室辅助要求,短期应用于实验犬有效、安全、稳定,长期使用效果尚需进一步实验证明。%Objective To study in vitro hydrodynamics of a pneumatic pulsatile ventricular assist device developed ex⁃clusively by China, and establish an animal model for the detection by the device. Methods The hydromechanics experi⁃ment was performed on an in vitro test loop using MEDOS-System to drive the ventricular assist device, and lycerl-water so⁃lution was used as circulating medium. The changes of afterload pressure and the output of the pump were monitored, and the impermeability and stability were also assessed after the experiment. Six adult dogs were used as the experimental animals. The device worked in the left heart assistance mode for 1 hour then the ventricular fibrillation was induced by potassium chloride, and then defibrillated after 5 min while the device remained working. The hemodynamics data were monitored con⁃secutively during

  3. 国产气动搏动性心室辅助装置的体外流体力学及动物实验观察%Study of hydrodynamic in vitro and animal experiment of a homebred pneumatic pulsatile ventricular assist device

    Institute of Scientific and Technical Information of China (English)

    史国宁; 陈庆良; 陈彤云; 刘建实

    2015-01-01

    Objective To study in vitro hydrodynamics of a pneumatic pulsatile ventricular assist device developed ex⁃clusively by China, and establish an animal model for the detection by the device. Methods The hydromechanics experi⁃ment was performed on an in vitro test loop using MEDOS-System to drive the ventricular assist device, and lycerl-water so⁃lution was used as circulating medium. The changes of afterload pressure and the output of the pump were monitored, and the impermeability and stability were also assessed after the experiment. Six adult dogs were used as the experimental animals. The device worked in the left heart assistance mode for 1 hour then the ventricular fibrillation was induced by potassium chloride, and then defibrillated after 5 min while the device remained working. The hemodynamics data were monitored con⁃secutively during the trial. Results The ventricular assist device worked stably and reliably during the hemodynamic exper⁃iment. The pump can generate more than 4 L/min flow against the afterload pressure of 100 mmHg. There were no significant changes in heart rate at different time points in experimental dogs after left ventricular assist. Comparison between after auxil⁃iary immediately and former auxiliary, the diastolic blood pressure of dogs increased 30 mmHg with the ventricular assist, and the diastolic pressure increased 19 mmHg. No obvious fluctuation in blood pressure was found during the auxiliary pro⁃cess. The diastolic blood pressure stayed at 60 mmHg when the heart was in ventricular fibrillation, and returned to normal after electrical defibrillation. Conclusion The ventricular assist device works stably in vitro test, and the pump can meet the need of adult’s ventricular assist. It is effective and security to dogs in short term. The effects of long-term use need to be future proved.%目的:对我国自主研发气动搏动性心室辅助装置进行体外流体力学检验及活体动物应用实验,检验

  4. РЕЗУЛЬТАТЫ ВНУТРИПОЛОСТНОЙ ЛУЧЕВОЙ ТЕРАПИИ В КОМПЛЕКСНОМ ЛЕЧЕНИИ РАБДОМИОСАРКОМЫ ВЛАГАЛИЩА И ШЕЙКИ МАТКИ У ДЕТЕЙ

    OpenAIRE

    Синягина, Юлия; Нечушкина, Иннеса; Марьина, Лия; Нечушкин, Михаил

    2011-01-01

    Цель исследования состояла в повышении эффективности лечения, снижении количества рецидивов путем внедрения внутриполостной лучевой терапии в программу комплексной терапии у детей, больных рабдомиосаркомой влагалища и шейки матки. Комплексное лечение с включением внутриполостной лучевой терапии проводили 33 девочкам с рабдомиосаркомой влагалища и шейки матки в возрасте от 1 года до 15 лет. Внутриполостную лучевую терапию проводили по методике «simple afterloading» (60Со) 25 детям, по методике...

  5. 磁液悬浮离心血泵体外溶血的实验及耐久性实验%In Vitro Hemolysis Test and Durability Test of Magnetic and Hydrodynamic Levitation Blood Pump

    Institute of Scientific and Technical Information of China (English)

    张文; 张杰民; 刘天文; 刘晓程

    2014-01-01

    通过建立模拟循环管路系统来研究磁液悬浮离心血泵的溶血性能及机械稳定性。建立体外模拟循环管路系统,体外溶血实验中以新鲜羊血为循环介质,调节前负荷和后负荷分别为15、100 mmHg,血泵转速设定为2900 rpm,测定血浆游离血红蛋白含量(FHb)和红细胞压积(Hct),计算血泵标准溶血指数(NIH);耐久性试验其他各项设定同体外溶血实验,循环介质改为甘油水溶液。在体外溶血实验中,测得磁液悬浮离心血泵NIH值为(0.0038±0.0008)g/100L;耐久性实验中血泵连续正常运转90 d,期间无卡壳、停泵等现象,电压、电流、转速稳定。该血泵溶血性能处于较高水平,机械性能稳定可靠,满足进一步进行动物实验的要求。%To study the hemolytic performance and durability of magnetic and hydrodynamic levitation blood pump by using vitro circulation loop system.The vitro circulation loop system was established.In vitro hemolysis test,the fresh sheep blood was collected as the circulating medium ,the speed of blood pump was adjusted to 2 900 rmp,the preload and afterload were set at 15,100 mmHg,plas-ma free hemoglobin(FHB)and hematokrit(Hct)were detected,then the normalized index of hemolysis (NIH)was calculated.In the durabilyt test,all the materials and environment settings were as same as them in vitro hemolysis test except the medium replaced by glycerin water.The blood pump had operated for 90 d continuoustly and recorded its performance.In vitro hemolysis test,the NIH was (0.0038 ±0.0008)g/100L.In durability test,the blood pump operated smoothly and stably without being stucked and shut down.The magnetic and hydrodynamic levitation blood pump has good hemolytic performance and stable mechanical property that can meet the need for animal experiments.

  6. Short-term efficacy of paclitxel plus cisplatin combined with adiotherapy on advanced cervix cancer%紫杉醇联合顺铂方案同步放化疗治疗中晚期宫颈癌近期疗效观察

    Institute of Scientific and Technical Information of China (English)

    汪志求; 韩光锋; 段爱雄

    2012-01-01

    目的:观察紫杉醇联合顺铂方案同步放化疗治疗中晚期宫颈癌的近期疗效和不良反应.方法:选择Ⅱb~Ⅲb期宫颈癌36例同步放化疗,放疗分次量每次2 Gy,每周5次,总剂量50 Gy,体外照射开始后1周,采用192Ir高剂量率子宫腔内后装照射,腔内照射每周1次,A点剂量每次7Gy,共6次.放疗期间采用紫杉醇135 mg/m2,d1,顺铂25 mg/m2,d1~d3方案同步化疗,每3~4周重复,共2周期,观察近期疗效和不良反应.结果:36例患者完全缓解27例,部分缓解7例,进展2例,有效率94.4%.患者病理类型和临床分期间有效率差异均无统计学意义(P>0.05).不良反应主要为中性粒细胞下降和放射性直肠反应.结论:紫杉醇联合顺铂同步放化疗近期疗效肯定,不良反应可以耐受.%Objective: To observe the short-term efficacy and toxicity of paclitxel plus cisplatin combined with radiotherapy in treatment of advanced cervix cancer. Methods: Thirty-six patients with advanced cervix cancer ( II b- HI b ) received concurrent chemoradiotherapy. The external irradiation dose of radiotherapy was 2Gy per time,5d/W, with a total dose of 50Gy;l92Ir high-dose-rate afterloading unit was adopted for branchytherapy one week after external radiotherapy, at a dose of 7 Gy per time in A point for 6 times. Paclitxel ( 135mg/m2 , d1 ) and cisplatin ( 25mg/m2 , d1- d3 ) were given every 3-4 weeks for two cycles concurrently with radiotherapy. The short effectiveness and toxic reaction were observed in these patients. Results: Of the 36 cases, complete response was observed in 27 cases, partial response in 7 cases and two cases presented certain progress. The overall response rate was 94. 4% . There was no statistical significance in differences of patients' pathologic patterns and clinical stages( P > 0. 05 ). The main toxicities were leucopenia and radiation rectal reaction. Conclusions: The short term efficacy of concurrent chemoradiotherapy with paclitxel and cisplatin is

  7. Low dose rate caesium-137 implant time of intracavitary brachytherapy source of a selected oncology center in Ghana

    Directory of Open Access Journals (Sweden)

    John Owusu Banahene

    2015-01-01

    Full Text Available Background: The treatment time taken for a radioactive source is found to be very important in intracavitary brachytherapy treatment. The duration of the treatment time depends on the prescribed dose requested to a reference point and the calculated dose rate to the same point. The duration of the treatment time of source is found to depend on the tumour stage. In this work, the treatment time of implant has been calculated for a Caesium-137 low dose rate brachytherapy source at an oncology facility in Ghana. Objective: The objective was to determine how the treatment time of tumours depends on the dose rate to the reference point prescribed by the Oncologists and the dose rate determined by the dosimetrists at the facility. Materials and Method: Depending upon the stage of the cancer, the Oncologist determines the type of treatment modality, source configuration for the cancer patient and positions of both tandem and ovoids in the cervix. Depending also on the tumour stage, two orthogonal radiographic X-ray films are taken using a simulator machine. The treatment machine used in the study is AMRA-Curietron. The maximum activity of the source was 259GBq. It has five channels which is a manual remote afterloader. In clinical practice, the treatment time t is very short(only some few days for such low dose rate brachytherapy source like Cs-137 which lasts only for some few days in comparison with the half life of the Cs-137 source. The mathematical equation for the calculation of treatment time is written as t=D/D. Hence t is the treatment time of the radioactive source of patients undergoing intracavitary brachytherapy treatment, D is prescribed dose to a reference point and D is the dose rate to the same reference point. Results: The calculated treatment time of the Cs-137 brachytherapy source for different source arrangements or channels used in clinical practice at the brachytherapy Centre have been determined. Also provided, are the

  8. In Vitro Hemolysis Test and Durability Test of Magnetic and Hydrodynamic Levitation Blood Pump%磁液悬浮离心血泵体外溶血的实验及耐久性实验

    Institute of Scientific and Technical Information of China (English)

    张文; 张杰民; 刘天文; 刘晓程

    2014-01-01

    通过建立模拟循环管路系统来研究磁液悬浮离心血泵的溶血性能及机械稳定性。建立体外模拟循环管路系统,体外溶血实验中以新鲜羊血为循环介质,调节前负荷和后负荷分别为15、100 mmHg,血泵转速设定为2900 rpm,测定血浆游离血红蛋白含量(FHb)和红细胞压积(Hct),计算血泵标准溶血指数(NIH);耐久性试验其他各项设定同体外溶血实验,循环介质改为甘油水溶液。在体外溶血实验中,测得磁液悬浮离心血泵NIH值为(0.0038±0.0008)g/100L;耐久性实验中血泵连续正常运转90 d,期间无卡壳、停泵等现象,电压、电流、转速稳定。该血泵溶血性能处于较高水平,机械性能稳定可靠,满足进一步进行动物实验的要求。%To study the hemolytic performance and durability of magnetic and hydrodynamic levitation blood pump by using vitro circulation loop system.The vitro circulation loop system was established.In vitro hemolysis test,the fresh sheep blood was collected as the circulating medium ,the speed of blood pump was adjusted to 2 900 rmp,the preload and afterload were set at 15,100 mmHg,plas-ma free hemoglobin(FHB)and hematokrit(Hct)were detected,then the normalized index of hemolysis (NIH)was calculated.In the durabilyt test,all the materials and environment settings were as same as them in vitro hemolysis test except the medium replaced by glycerin water.The blood pump had operated for 90 d continuoustly and recorded its performance.In vitro hemolysis test,the NIH was (0.0038 ±0.0008)g/100L.In durability test,the blood pump operated smoothly and stably without being stucked and shut down.The magnetic and hydrodynamic levitation blood pump has good hemolytic performance and stable mechanical property that can meet the need for animal experiments.

  9. JS ISH-ESH-2 UPDATE ON THE DETECTION AND FOLLOW-UP OF EARLY HYPERTENSIVE HEART DISEASE.

    Science.gov (United States)

    Rosei, Enrico Agabiti

    2016-09-01

    , LV mass reproducibility represents one of the major technical limitations of echocardiography and LV mass calculation may be not reliable in patients with previous myocardial infarction or with asymmetrical hypertrophy, assuming a prolate ellipsoid shape for the left ventricle. For this reason LV mass measurement with cardiac magnetic resonance (CMR) imaging, which is indubitably more accurate and reproducible, has been proposed, but with obvious limitations related to availability and costs of the technique.Three-dimensional echocardiographic (3DEcho) imaging represents a relevant innovation in cardiovascular imaging. The development of fully sampled matrix-array transducers, together with significant improvements in hardware and software of ultrasound systems, has made possible excellent real-time imaging of the beating heart in 3D. More recent studies indicate that 3DEcho has an excellent accuracy and provides better correlations that 2-dimensional echocardiography with MRI measurements.Echocardiography may also give useful information on cardiac functional changes, including systolic and diastolic abnormalities. LV diastole may be accurately evaluated by assessment of transmitral flow velocities, mitral annular pulsed tissue Doppler imaging and left atrial volume assessment. In uncomplicated hypertensives LV systolic dysfunction, as assessed by LV shortening fraction (FS) and ejection fraction (EF), expressing endocardial fibers shortening are usually preserved or even "supernormal", while midwall FS is reduced. In the absence of major structural abnormalities, the TDI measurement of longitudinal myocardial systolic velocity has been proposed as a reliable index of myocardial performance, independent of LV preload and afterload.Compared to the conventional 2D traditional approach, 3D echo offers the opportunity for a more sophisticated assessment of LV function, by the improvement in the accuracy of the evaluation of left ventricular and left atrial volumes by

  10. 多层放射性铬胶片剂量验证系统的研制%Development of multi-layer radiochromic film dose verification system

    Institute of Scientific and Technical Information of China (English)

    张可; 谢玲灵; 张中柱; 戴建荣

    2014-01-01

    and analysis are reduced, and physicist's workload is also diminished. The gamma index passing rate for 6 cases are all over 90%with 3% dose difference and 3mm DTA criteria. The system can be used for the machine QA, such as linear accelerator, gamma knife, cyber knife, afterloading unit, interstitial brachytherapy as well as the patient specific 2D and 3D IMRT plan QA. Conclusion:Multifilm QA system is a versatile tool for IMRT dose verification and regular quality assurance. It is convenient, accurate, authentic, huge amounts of information and multi-purpose, etc. It can be used in the dose verification for VMAT and IMRT plan besides daily quality assurance of accelerator.

  11. Effective treatment of Stage I uterine papillary serous carcinoma with high dose-rate vaginal apex radiation (192Ir) and chemotherapy

    International Nuclear Information System (INIS)

    Purpose: Uterine papillary serous carcinoma (UPSC) is a morphologically distinct variant of endometrial carcinoma that is associated with a poor prognosis, high recurrence rate, frequent clinical understaging, and poor response to salvage treatment. We retrospectively analyzed local control, actuarial overall survival (OS), actuarial disease-free survival (DFS), salvage rate, and complications for patients with Federation International of Gynecology and Obstetrics (FIGO) (1988) Stage I UPSC. Methods and Materials: This retrospective analysis describes 38 patients with FIGO Stage I UPSC who were treated with the combinations of radiation therapy, chemotherapy, total abdominal hysterectomy, and bilateral salpingo-oophorectomy (TAH/BSO), with or without a surgical staging procedure. Twenty of 38 patients were treated with a combination of low dose-rate (LDR) uterine/vaginal brachytherapy using 226Ra or 137Cs and conventional whole-abdomen radiation therapy (WART) or whole-pelvic radiation therapy (WPRT). Of 20 patients (10%) in this treatment group, 2 received cisplatin chemotherapy. Eighteen patients were treated with high dose-rate (HDR) vaginal apex brachytherapy using 192Ir with an afterloading device and cisplatin, doxorubicin, and cyclophosphamide (CAP) chemotherapy (5 of 18 patients). Only 6 of 20 UPSC patients treated with combination LDR uterine/vaginal brachytherapy and conventional external beam radiotherapy underwent complete surgical staging, consisting of TAH/BSO, pelvic/para-aortic lymph node sampling, omentectomy, and peritoneal fluid analysis, compared to 15 of 18 patients treated with HDR vaginal apex brachytherapy. Results: The 5-year actuarial OS for patients with complete surgical staging and adjuvant radiation/chemotherapy treatment was 100% vs. 61% for patients without complete staging (p = 0.002). The 5-year actuarial OS for all Stage I UPSC patients treated with postoperative HDR vaginal apex brachytherapy and systemic chemotherapy was 94% (18

  12. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy.

    Directory of Open Access Journals (Sweden)

    Luciana Tourinho Campos

    Full Text Available The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®; it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86, which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21, which is also from BEBIG.The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the photoelectric effect, pair

  13. Extreme challenges on cardiovascular control during gravity transitions

    Science.gov (United States)

    Verheyden, B.; Beckers, F.; Aubert, A. E.

    Introduction. During parabolic flights transient periods of hypergravity and microgravity are created. These periods cause translocations of bodily fluids in the longitudinal axis of the body, leading to altered cardiac preload and afterload. These extreme orthostatic challenges provide a unique platform to study baroreflex-mediated responses of the cardiovascular autonomic control system. This might have important features for the development of a model of cardiovascular deconditioning that is observed in a variety of patient populations. Purpose. Until now, due to methodological restrictions, most studies have been concentrating on the analysis of cardiovascular variability in time domain. The purpose of this study is to evaluate heart rate variability (HRV) and blood pressure variability (BPV) simultaneously, using frequency domain analysis techniques (low frequency power (LF: 0.04-0.15 Hz); high frequency power (HF: 0.16-0.4 Hz)), providing additional information about cardiac and vasomotor sympathetic modulation during gravity transitions. Methods. 12 healthy non-medicated volunteers (age = 24 ± 2.5 yr) underwent continuous ECG and blood pressure (BP) recordings during the 32nd and 34th parabolic flight campaign organized by ESA. The subjects performed 15 parabolas in supine and 15 parabolas in standing position. 5 transient gravity phases were abstracted; phase 1 and 5: before and after the parabola (1G); phase 2 and 4: at the ascending and descending leg of the parabola (2G); phase 3: at the apex of the parabola (0g). Phase 2, 3 and 4 last 20 seconds. Results. No significant differences were found in HRV and BPV parameters in supine position between the different gravity phases. In standing position, mean RR- interval was higher during 0G (900 ± 103 ms) compared to 1G (700 ± 87 ms) and 2G (600 ± 94 ms). Mean arterial BP remained relatively constant during 0G but tended to decrease during 2G (102 ± 2 mmHg vs. 105 ± 3 mmHg). Positive correlations were

  14. Selected Abstracts of the 1st Congress of joint European Neonatal Societies (jENS 2015; Budapest (Hungary; September 16-20, 2015; Session “Circulation, O2 Transport and Haematology”

    Directory of Open Access Journals (Sweden)

    Various Authors

    2015-09-01

    -CONFIRMED PDA • C. Kotidis, M. TurnerABS 7. HAEMODYNAMICS IN PRETERM INFANTS WITH PATENT DUCTUS ARTERIOSUS (HAPI-PDA STUDY: A PILOT STUDY • C. Kotidis, N. Subhedar, M. Weindling, M. TurnerABS 8. SKIN MICROCIRCULATION IN ASPHYXIATED NEWBORNS TREATED WITH HYPOTHERMIA • S. Fredly, D. Fugelseth, C.S. Nyggard, T. Stiris, K. KverneboABS 9. PLETH VARIABILITY INDEX IN PRETERM INFANTS: IS IT FEASIBLE? • H.A. van Elteren, T.G. Goos, I.K.M. Reiss, R.C.J. de Jonge, V.J. van den BergABS 10. VALIDITY OF BIOMARKERS ON CARDIOVASCULAR SUPPORT (CVS: AN ANALYSIS IN RETROSPECT • A. Pellicer, M.C. Bravo, P. López-Ortego, L. Sanchez, R. Madero, F. Cabañas; the Neocirculation Study GroupABS 11. PILOT STUDY OF DOBUTAMINE (DB VERSUS PLACEBO (PL FOR EARLY LOW SUPERIOR VENA CAVA (SVC FLOW: LONG-TERM OUTCOME • M.C. Bravo, P. López-Ortego, L. Sánchez, R. Madero, F. Cabañas, A. PellicerABS 12. THROMBOELASTOGRAPHYCAL ASSESSMENT OF THE HEMOSTATIC SYSTEM IN NEWBORNS WITH PERIVENTRICULAR HEMORRHAGE • K. LeonavaABS 13. THE EFFECT OF ANTENATAL MAGNESIUM SULFATE ADMINISTRATION ON LEFT VENTRICULAR AFTERLOAD AND MYOCARDIAL PERFORMANCE MEASURED USING DEFORMATION AND ROTATIONAL MECHANICS IMAGING • J.D. Corcoran, B. Hayes, O. Franklin, A. EL-KhuffashABS 14. THE EFFECT OF MATERNAL ANTIHYPERTENSIVE DRUGS ON CEREBRAL, RENAL AND SPLANCHNIC OXYGEN EXTRACTION IN PRETERM BORN NEONATES • A.E. Richter, T.E. Schat, K.N.J.A. Van Braeckel, A.F. Bos, E.M.W. KooiABS 15. SERUM NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN AS AN EARLY MARKER OF ACUTE KIDNEY INJURY IN NEONATES WITH HYPOPLASTIC LEFT HEART SYNDROME • P. Surmiak, M. Baumert, Z. Walencka, A. WitekABS 16. A PROSPECTIVE STUDY INTO THE GENERATION OF INDIVIDUALISED OPTIMAL MEAN ARTERIAL BLOOD PRESSURE (MABP MEASUREMENTS USING NEAR-INFRARED SPECTROSCOPY (NIRS IN THE PRETERM NEONATE • G. Stevenson, C. Costa, M. Czosnyka, P. Smielewski, T. AustinABS 17. THE EFFECTS OF SKIN-TO-SKIN ON PLACENTAL TRANSFUSION: A NONRANDOMIZED PILOT CONTROLLED TRIAL • D

  15. Endostatin improves the effect of radiotherapy in the treatment of squamous carcinoma of the uterine cervix%重组人血管内皮抑制素促进子宫颈鳞状细胞癌放疗效果的临床观察

    Institute of Scientific and Technical Information of China (English)

    刘晨; 杨蓉; 张凡; 陈江平

    2013-01-01

    Objective: To study the clinical efficacy of the combination of radiotherapy and endostatin injection in the treatment of moderate and advanced squamous carcinoma of the uterine cervix. Methods: Sixty patients with moderate and advanced cervical cancer were randomized divided into two groups; experiment group (n =30, treated with endostatin plus radiotherapy) and control group (n = 30, treated with radiotherapy alone). The radiotherapy in all patients was extracorporeal irradiation and intracavitary afterloading therapy. Endostatin (7. 5mg/m2 · d) was intravenously given for consecutive 14 days, followed by a 7 - day interval of rest, as a treatment cycle. The tumor vascular imaging parameters were detected by CT scan before treatment and 1,2,3,4 weeks after treatment, respectively, to assess the short - term efficacy of the treatment. Results : (1) In the experiment group, the degree of tumor vascular tortuosity and swelling was reduced, and the distribution of tumor vasculum was more evenly, showing different degrees of normalization, which was more evident at the first week after treatment. The tissue blood flow, blood volume, and mean transit time after treatment were significantly greater than those before treatment ( P 0.05). (2) In the control group, the tumor vascular morphology and distribution pattern had apparent changes after treatment, and the tissue blood flow, tissue blood volume, and mean transit time after treatment were significantly higher than those before treatment (P < 0.05 ). But the degree of these changes was significant lower than that of experiment group ( P < 0. 05 ). (3) There was a significant difference in the 5 - year survival rate, recurrence rate and progression - free survival rate, respectively, between two groups (P <0.05) , with the better efficacy in experiment group. Conclusion; The radiotherapy is a positive means for the treatment of moderate and advanced cervical cancer, and endostatin injection could improve the effect

  16. Assessment of left ventricular radial systolic function of rat models with chronic heart failure by two-dimensional speckle tracking imaging%二维斑点追踪成像技术评价实验性大鼠慢性心力衰竭模型左心室径向收缩功能

    Institute of Scientific and Technical Information of China (English)

    覃小娟; 谢明星; 王静; 吕清; 方凌云; 付倩; 黄桂

    2012-01-01

    (PWT), fraction shortening (FS) and ejection fraction (EF) were measured at the left ventricular chordate level before operation and 2, 4 and 8 weeks after operation with M-mode echocardiography. High frame rate dynamic 2D images were recorded from the left ventricular short-axis views at the papillary muscle level. Peak systolic radial strains (PRS) of 6 segments and global peak radial strain (GPRS) were measured with 2D-STI. All the parameters were compared between the two groups at the same time points, and the changes of values were observed in each group at the different time points. Results Compared with the values of pro-surgical and sham-surgical group at the same time point, there was no significant difference of each value in 2 weeks after operation (all P>0. 05). Four weeks after operation, IVST, PWT in operation group increased, but PRS and GPRS decreased (all P0. 05). PRS obtained in intra- and inter-group both showed high agreement. Conclusion 2D-STI can observe left ventricular myocardial fibers radial remodeling and the progress of contraction function changes induced by after-load increasing. It is an efficient method to evaluate left ventricular function in CHF rat models.

  17. Causas incomuns de instabilidade hemodinâmica durante revascularização miocárdica sem circulação extracorpórea Causas poco comunes de inestabilidad hemodinámica durante la revascularización miocárdica sin circulación extracorpórea Uncommon causes of hemodynamic instability during myocardial revascularization without cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Luciana Moraes dos Santos

    2010-02-01

    difficult to wean those patients off CB. Intraoperative control demands strict hemodynamic adjustment, as well as partial clamping of the aorta to minimize hemodynamic changes. The objective of this study was to report two cases of hemodynamic instability during MR without CB after partial clamping of the aorta. CASE REPORT: The first case is a female patient, whose aortic diameter was slightly reduced (2.8 cm; the second case refers to a patient with left ventricular ejection fraction (LVEF of 24% on the echocardiogram. In both cases, significant hypotension and increase in pulmonary blood pressure were observed immediately after clamping of the aorta. The surgical teams were informed of the problem, and in both cases the hemodynamic instability was reverted after unclamping of the aorta. Afterwards, smaller areas of the aorta were clamped and proximal anastomoses were performed without intercurrence. CONCLUSIONS: Although cardiac manipulation and changes in ventricular preload represent the most common causes of hemodynamic instability during MR without CB, in the cases presented here, hypotension and pulmonary hypertension were most likely secondary to a reduction in cardiac output due to the increase in afterload in patients with a relatively small aortic diameter or ventricular dysfunction even with partial clamping. Adequate intraoperative monitoring and immediate correction of the hemodynamic changes can minimize surgical morbidity and mortality.

  18. Efeitos da pressão positiva contínua nas vias aéreas na insuficiência cardíaca crônica Efectos de la presión positiva continua en las vías aéreas en la insuficiencia cardíaca crónica Effects of the continuous positive airway pressure on the airways of patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    João Carlos Moreno de Azevedo

    2010-07-01

    60 min., 5 veces por semana, durante 1 mes, en el período diurno. Fueron analizados ecocardiograma y ergoespirometría, antes y después de 30 días de terapia. RESULTADOS: Presentó aumento de 19,59% en la fracción de eyección del ventrículo izquierdo (FEVE: 23.9 ± 8.91 vs 27.65 ± 9.56%; p = 0,045. En la ergoespirometría, el tiempo de ejercicio (Tex presentó aumento significativo de 547 ± 151,319 vs 700 ± 293,990 seg., p = 0,02, el consumo de oxígeno (VO2 fue de 9,59 ± 6,1 vs 4,51 ± 2,67 ml.kg-1.min.-1, p = 0,01, en cuanto a la producción de dióxido de carbono (VCO2 de reposo (9,85 ± 4,38 vs 6,44 ± 2,88 ml.kg-1.min.-1, p = 0,03 presentó disminución. CONCLUSIÓN: La CPAP provocó aumento en la fracción de eyección del ventrículo izquierdo y en el tiempo de ejercicio, disminuyó el consumo de oxígeno y la producción de dióxido de carbono en reposo.BACKGROUND: Heart failure can present with asymptomatic dysfunction at decompensation, with limitations and decrease in the productive capacity. The Continuous Positive Airway Pressure (CPAP is a non-pharmacological means to decrease afterload. OBJECTIVE: To analyze the effects of CPAP (10 cmH2O, for 30 days in patients with chronic heart failure. METHODS: We assessed 10 patients with heart failure (6 males, 4 females of several etiologies, with a mean age of 54 ± 14 years, with a BMI of 21 ± 0.04 kg/m². The therapy was applied for 60 min., 5 times a week for 30 days, during the daytime. The echocardiogram and the ergospirometry were analyzed, before and 30 days after the therapy. RESULTS: There was a 19.59% increase in the left ventricular ejection fraction (LVEF: 23.9 ± 8.91 vs 27.65 ± 9.56%; p = 0.045. At the ergospirometry, the exercise time (ET showed a significant increase from 547 ± 151.319 vs 700 ± 293.990 sec., p = 0.02; oxygen consumption (VO2 was 9.59 ± 6.1 vs 4.51 ± 2.67 ml.kg-1.min.-1, p = 0.01, whereas the carbon dioxide production (VCO2 at rest (9.85 ± 4.38 vs 6.44 ± 2.88 ml

  19. 宫颈癌宫旁残留两种后程加量方式剂量学比较%Dosimetry Comparison of 2 Types of Late Vestigal Dosages Mode Side with Cervical Neoplasms

    Institute of Scientific and Technical Information of China (English)

    钟沛霖; 冯梅; 程燕铭; 李秀华; 郭爱华; 蔡勇君

    2016-01-01

    目的 对三维宫旁插植后装放疗与体外调强放射治疗在宫颈癌放疗后宫旁残留后程加量中对靶区、膀胱、乙状结肠及直肠的剂量学对比研究.方法 12例局部晚期宫颈癌在完成全部放疗后宫旁残留进行宫旁后程加量,用ONCENTRA治疗系统分别设计三维后装放疗计划及体外调强放射治疗计划.利用体积直方图分别评价膀胱、直肠、乙状结肠的受照剂量;比较两组间膀胱、直肠、乙状结肠受照剂量的差别.结果 两种放疗方法均能很好覆盖靶区,满足计划要求,三维插植后装放疗直肠剂量在1 cm3、2 cm3、5 cm3时分别为(3.24±1.21)Gy、(2.98±1.01)Gy、(2.43±0.87)Gy,膀胱平均剂量在1 cm3、2 cm3、5 cm3时分别为(2.04±0.58)Gy、(1.82±0.56)Gy、(1.46±0.32)Gy,乙状结肠平均剂量在1 cm3、2 cm3、5 cm3时分别为(1.37±0.61)Gy、(0.91±0.24)Gy、(0.76±0.19)Gy.体外调强放射治疗直肠剂量在1 cm3、2 cm3、5 cm3时分别为(4.84±1.34)Gy、(4.32±1.12)Gy、(3.76±1.01)Gy,膀胱剂量在1 cm3、2 cm3、5 cm3时分别为(3.43±1.12)Gy、(3.10±1.02)Gy、(2.69±1.01)Gy,乙状结肠平均剂量在1 cm3、2 cm3、5 cm3时分别为(2.37±0.98)Gy、(2.05±0.78)Gy、(1.77±0.88)Gy.与体外调强放疗计划对后程加量中相比,三维宫旁插植后装放疗对直肠、乙状结肠、直肠的剂量更低,存在统计学差异(P<0.01).结论 CT图像引导下三维宫旁插植后装放疗在宫旁残留后程加量中对膀胱、乙状结肠及直肠的保护更好,将能降低膀胱、乙状结肠、直肠并发症出现概率.%Objective To study the dosimetry comparison in target section ,bladder,sigmoid flexure and rectal between three-dimensional brachytherapy afterloading radiotherapy side with cervical neoplasms and external intensity -modulated radiother-apy processing the late vestigal dosages side with cervical neoplasms after the cervical neoplasms radiotherapy .Methods Imple-ment the late vestigal dosages

  20. Anestesia para o recém-nascido submetido a cirurgia cardíaca com circulação extracorpórea Anestesia para el recién nacido sometido a cirugía cardiaca con circulación extracorpórea Anesthesia for the newborn submitted to cardiac surgery with cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Sérgio Bernardo Tenório

    2005-02-01

    ítrico o los inhibidores de la fosfodiesterasa. CONCLUSIONES: El anestesista tiene papel preponderante en el ajuste de la homeostasia durante el período peri-operatorio. Conocimientos sobre el tipo de lesión cardiaca, la corrección a ser realizada, la respuesta del organismo a la CEC pueden ser útiles en el manoseo de estos niños.BACKGROUND AND OBJECTIVES: Congenital heart diseases affect 0.8% of liveborn infants and many need neonatal surgical correction. Cardiac surgery with cardiopulmonary bypass (CPB in this age is associated to higher risk of complications related to child's functional immaturity, lack of CPB equipment fully compatible with neonate (NN size and technical difficulties to correct cardiac defects. This article aimed at describing aspects related to anesthetic technique, CPB and their effects on NN. CONTENTS: High fentanyl or sufentanil doses promote adequate anesthesia without interfering with cardiocirculatory stability. Opioids residual respiratory depression is not a problem for these patients because most of them will need immediate postoperative respiratory assistance. CPB may be followed by heart manipulation-induced hypotension and/or bleeding. Inadequate venous and aortic cannula position may lead to severe complications, such as insufficient brain flow or difficult venous drainage. Deep hypothermia and total circulatory arrest are common during CPB. Hypothermia changes blood viscosity, which is treated with hemodilution and has implications on pH correction (alpha-stat versus pH stat. Low cardiac output is common during CPB weaning and adjustments in one or all its components (preload, contractility, afterload and heart rate may be necessary. In addition to classic drugs, such as epinephrine and dopamine, other substances may be needed, such as aprotinin, nitric oxide or phosphodiesterase inhibitors. CONCLUSIONS: Anesthesiologists play a major role in adjusting perioperative homeostasis. Understanding the type of cardiac disease, the

  1. JS ISH-ESH-2 UPDATE ON THE DETECTION AND FOLLOW-UP OF EARLY HYPERTENSIVE HEART DISEASE.

    Science.gov (United States)

    Rosei, Enrico Agabiti

    2016-09-01

    , LV mass reproducibility represents one of the major technical limitations of echocardiography and LV mass calculation may be not reliable in patients with previous myocardial infarction or with asymmetrical hypertrophy, assuming a prolate ellipsoid shape for the left ventricle. For this reason LV mass measurement with cardiac magnetic resonance (CMR) imaging, which is indubitably more accurate and reproducible, has been proposed, but with obvious limitations related to availability and costs of the technique.Three-dimensional echocardiographic (3DEcho) imaging represents a relevant innovation in cardiovascular imaging. The development of fully sampled matrix-array transducers, together with significant improvements in hardware and software of ultrasound systems, has made possible excellent real-time imaging of the beating heart in 3D. More recent studies indicate that 3DEcho has an excellent accuracy and provides better correlations that 2-dimensional echocardiography with MRI measurements.Echocardiography may also give useful information on cardiac functional changes, including systolic and diastolic abnormalities. LV diastole may be accurately evaluated by assessment of transmitral flow velocities, mitral annular pulsed tissue Doppler imaging and left atrial volume assessment. In uncomplicated hypertensives LV systolic dysfunction, as assessed by LV shortening fraction (FS) and ejection fraction (EF), expressing endocardial fibers shortening are usually preserved or even "supernormal", while midwall FS is reduced. In the absence of major structural abnormalities, the TDI measurement of longitudinal myocardial systolic velocity has been proposed as a reliable index of myocardial performance, independent of LV preload and afterload.Compared to the conventional 2D traditional approach, 3D echo offers the opportunity for a more sophisticated assessment of LV function, by the improvement in the accuracy of the evaluation of left ventricular and left atrial volumes by

  2. 脉搏指示连续心排血量监测技术救治重症胰腺炎并发急性呼吸窘迫综合征患儿二例%Pulse indicator continuous cardiac output measurement-guided treatment aids two pediatric patients with severe acute pancreatitis complicated with acute respiratory distress syndrome

    Institute of Scientific and Technical Information of China (English)

    颜卫源; 王丽杰

    2014-01-01

    PICU,EVLWI dropped to 6 ml/kg,GEDVI dropped to 370 mL/m2,and the oxygenation index increased to 180 mmHg.On day 8,the patient was successfully weaned from the ventilator.However,on day 9,the patient reverted to mechanical ventilation due to secondary infection.On day 30,the patient was discharged for voluntarily giving up treatment.Late follow-up results showed that the patient was dead one day after giving up treatment.Case 2 was admitted due to SAP induced by overeating one day before admission.On day 2,the patient showed dyspnea and oxygen saturation decreased to 80%.We applied mechanical ventilation,CVVHDF to remove inflammatory mediators and PiCCO to guide fluid management.According to the initial data of PiCCO,EVLWI was 9 m[/kg,GEDVI was 519 ml/m2,the oxygenation index was 298 mmHg,the bedside chest X-ray showed decreased permeability and PEEP was adjusted to 5 cmH2O,suggesting the existence of ARDS.During treatment,the dehydration speed of CVVHDF was set at 50 ml/h to maintain the balance of fluid input and output.Two hours after PiCCO monitoring,the oxygenation index decreased to 140 mmHg,GEDVI 481 ml/m2,EVLWI 9 ml/kg,thus the dehydration speed of CVVHDF was increased (up to 100 ml/h).On day 4 in the PICU,EVLWI was 9 ml/kg,GEDVI was 430 ml/m2,oxygenation index was 394 mmHg,and the bedside chest X-ray showed that permeability was higher.On day 5,the patient was transferred from PiCCO.On day 30,the patient recovered and was discharged.Conclusion PiCCO monitoring can provide real-time surveillance of cardiac function,cardiac preload and afterload,and extravascular lung water in pediatric patients with SAP combined with ARDS.These results are clinically significant for the rescue of critically ill patients with ARDS or shock.%目的 探讨脉搏指示连续心排血量监测(PiCCO)在指导儿童重症胰腺炎(SAP)并发急性呼吸窘迫综合征(ARDS)治疗中的作用.方法 对2例SAP合并ARDS患儿在综合治疗的同时进行PiCCO监测,根据心脏指

  3. Clinical study of rapid shallow breathing index as the switching point for sequential ventilation for patients with prolonged weaning after thoracolaparotomy%胸腹术后延迟撤机患者以浅快呼吸指数为切换点序贯通气治疗临床研究

    Institute of Scientific and Technical Information of China (English)

    丁欢; 周文艳; 王丽娟; 马希刚; 曹相原

    2015-01-01

    , pH, PaO2, PaCO2 and PaO2/FiO2;hemodynamic and microcirculation-related variables: HR, MAP, fluid balance, BNP and Lac;endocrine and metabolism variables : Hb, ALB and random serum cortisol (COR).The clinical features and the changes of the above-mentioned variables before and at the time of switching were compared between both groups.The independent sample t test was used for the single factor comparison and Mann-Whitney U test was applied to the non-normal distributions.The Fisher exact probability test was used for the single factor comparison of ranked data such as categorical variables.Results There were no significant differences in age, gender and severity of disease between two groups (P > 0.05);the successfully prolonged weaning group had longer duration of invasive mechanical ventilation and ICU stay compared with the refractory weaning group (P < 0.05).There were significant differences in cough severity, PaCO2, pH, HR and fluid balance between two groups before switching (P < 0.05).Compared with those before switching, in the refractory weaning group there were marked decrease in Lac (P < 0.05), obvious increase in cough severity, pH, Hb and ALB (P < 0.05), but there was no significant difference in COR (P > 0.05);while in the successfully delayed weaning group, there were significant decrease in CPIS, PaCO2, HR, MAP, BNP, fluid balance and Lac (P < 0.05), and cough severity, pH, ALB and COR showed an upward trend (P < 0.05).Conclusions The key of successful sequential ventilation is within the values of RSBI ranging from 80 to 120 times/ (min · L) during the initial SBT (60 min) selected as the switching point in patients with prolonged weaning after thoracolaparotomy.The major influencing factors for determining the ideal timing of switching include the matching status between respiratory endurance and respiratory work, the balance between myocardial strength and both cardiac preload and afterload, the severe disease associated with