Search results for " Radioisotope"
showing 10 items of 246 documents
Brachytherapy organ dose estimation using Monte Carlo simulations of realistic patient models
2018
Radiation Therapy Planning Systems (RTPS) currently used in hospitals contain algorithms based on deterministic simplifications that do not properly consider electrons lateral transport in the areas where there are changes of density, and as a result, erroneous dose predictions could be produced. According to this, the present work proposes the use of Monte Carlo method in brachytherapy planning systems, which could affect positively on the radiotherapy treatment planning, since it provides results that are more accurate and takes into account the in homogeneities density variations. This paper presents a Monte Carlo (MC) simulation of a brachytherapy prostate treatment with I-125 seeds, us…
Pronounced cholinergic but only moderate purinergic effects in isolated atrial and ventricular heart muscle from cats.
1989
1 The effects of cholinergic and purinergic stimulation on action potential, force of contraction and 86Rb efflux were investigated in cat atrial and/or ventricular heart muscle. 2 Acetylcholine and carbachol exerted a concentration-dependent negative inotropic effect in cat atrial heart muscle. Carbachol 10 μmol l−1 completely abolished the force of contraction and increased the rate constant of 86Rb efflux 2–3 fold, whereas the action potential duration was shortened to about 1/10 of its length under control conditions. 3 The effects of acetylcholine and carbachol in cat atrial heart muscle were mimicked, qualitatively, by adenosine and its analogues 5′-(N-ethyl)-carboxamido-adenosine (NE…
Liver Transplantation for Hepatocellular Carcinoma After Yttrium Therapy: A Case Report
2008
Yttrium-90 microspheres constitute one of the most recent treatment options for hepatocellular carcinoma (HCC) in the setting of cirrhosis. As such, their spectrum of indication is not yet fully established. Herein, we have reported the case of a patient with HCC beyond the listing criteria for liver transplantation (OLT) who was treated preoperatively with selective transarterial chemoembolization and yttrium-90 microspheres. He was subsequently transplanted with a liver from an 81-year-old donor allocated through Eurotransplant as a "rescue offer." The posttransplant course was uneventful. Pathologic examination revealed a multifocal, well-differentiated pT2 tumor with no vascular invasio…
Fecal Blood Loss in Patients With Colonic Polyps: A Comparison of Measurements With 51Chromium-Labeled Erythrocytes and With the Haemoccult Test
1982
Abstract The quantitative determinations of fecal daily blood loss after intravenous administration of 51Cr-labeled erythrocytes in 44 patients with colonic polyps and in 11 controls were compared with the results of the daily performed Haemoccult test without dietary restrictions. A total of 642 stool specimens was analyzed for 51Cr loss and the Haemoccult test. The mean fecal daily blood loss in the 34 patients with adenomatous polyps of the descending colon and rectosigmoid was 1.36 ± 0.14 ml/day (mean ± SEM), in the 10 patients with polyps of the ascending and transverse colon it was 1.28 ± 0.31 ml/day, and in the 11 controls 0.62 ± 0.07 ml/day. There was no positive Haemoccult test in …
Efficacy and safety of yttrium 90 ibritumomab tiuxetan in patients with relapsed or refractory diffuse large B-cell lymphoma not appropriate for auto…
2007
A prospective, multicenter, nonrandomized phase 2 trial was conducted to evaluate the efficacy and safety of a single dose of yttrium-90 (90Y) ibritumomab tiuxetan in elderly patients in first relapsed or primary refractory diffuse large B-cell lymphoma (DLBCL) ineligible for stem-cell transplantation. Patients had been previously treated with chemotherapy (group A, n = 76) or chemotherapy plus rituximab (group B, n = 28). Patients in group A were further divided into patients in whom induction therapy had failed (stratum AI, n = 33) and patients who had relapsed after achieving complete response (CR; stratum AII, n = 43). The overall response rate (ORR) was 52% and 53% in strata AI and AII…
Effects of sensitization on vasoactive intestinal polypeptide-induced relaxation and its concentration and binding in guinea-pig airways.
1993
We investigated the relaxant effect of vasoactive intestinal polypeptide (VIP) in trachea and lung parenchyma from normal and sensitized guinea-pigs. A technique by which drug access was restricted to either the mucosal or the adventitial surface of tracheal rings was used. In intact trachea, concentration-response curves for VIP entering from the mucosal surface (pD2 = 6.61 +/- 0.06) were displaced to the right compared with those for adventitial entry (pD2 = 6.78 +/- 0.04). Epithelium removal produced a leftward shift (approximately 2.8-fold) in the mucosal VIP concentration-response curve. Sensitization did not alter the responsiveness (maximal effect) or sensitivity (pD2 values) of trac…
Effect of endurance training on the capacity of red and white skeletal muscle of mouse to oxidize carboxyl-14C-labelled palmitate.
1977
Three groups of mice were trained for 1, 4 and 5 months according to different running programs on a motor driven treadmill and the fatty acid oxidation capacity (FAO) and the activities of some enzymes of energy metabolism (cytochrome c oxidase, malate dehydrogenase, triosephosphate dehydrogenase, and lactate dehydrogenase) were determined from m. quadriceps femoris (MQF). Endurance training increased the FAO [5-month training 4 days/week, 30 min/day 22% (p less than 0.05); 1-month training, 7 days/week, 150 min/day 37% (p less than 0.001); 4-month training, 5 days/week, 60 min/day 24% (p less than 0.05)]. The activities of cytochrome c oxidase and malate dehydrogenase increased approx. 30…
Papaverine decreases the efflux of42K in guinea-pig atrial heart muscle
1980
The effects of papaverine on resting potential and efflux of42K were investigated in guinea-pig left atria. Papaverine significantly reduced the potassium efflux in beating preparations. In resting preparations, the efflux of potassium was only slightly affected. However, the resting potential was significantly reduced by papaverine by about 5 mV.
Followup of irradiated prostatic carcinoma by aspiration biopsy.
1977
AbstractOf 66 patients with irradiated prostatic carcinoma 53 were controlled regularly by repeat aspiration biopsy every 6 months. Local sterilization was achieved in 43 per cent but the results of combined radiotherapy (endocrine therapy plus irradiation) were only 8 per cent more favorable than those in patients treated by radiotherapy alone. Thus, endocrine therapy is not warranted before the radiation effect is evaluated. Post-radiation treatment should be determined by the clinical and bioptic findings.
A presynaptic excitatory M1 muscarine receptor at postganglionic cardiac noradrenergic nerve fibres that is activated by endogenous acetylcholine.
1990
Rabbit atria were isolated with the extrinsic right vagus and sympathetic nerves intact and perfused with Tyrode solution. Noradrenaline overflow evoked by sympathetic nerve stimulation (SNS) at 3 Hz for 3 min was determined before, during, and after vagus nerve stimulation (VNS), also at 3 Hz and for 3 min. The VNS pulses preceded the SNS pulses by 3, 100 and 233 ms. Acetylcholine overflow was determined after labelling of the transmitter stores with [14C]choline. Pirenzepine 80 nmol/l failed to alter the muscarinic inhibition of noradrenaline overflow when the vago-sympathetic impulse intervals were 3 and 233 ms. At an interval of 100 ms VNS did not significantly inhibit noradrenaline ove…