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C G Soares

Publications and source records attributed to C G Soares.

7 recordsLinked to original sources
PubMed1992

Effects of haloperidol, bromocriptine and amphetamine on the development of Ehrlich ascites carcinoma in mice.

We determined the effect of 13 days of treatment with 2.0 mg/kg haloperidol, 4.0 mg/kg bromocriptine or 2.0 mg/kg amphetamine on the number of tumor cells of mice bearing Ehrlich ascites carcinoma. The dopaminergic blocker significantly reduced the number of tumor cells of experimental mice, but the two dopamine-mimetic drugs used did not significantly affect tumor development. These results suggest that although neuroleptic drugs to inhibit Ehrlich ascites tumors, this effect does not seem to be related to changes in dopaminergic neuronal transmission.

Amphetamine↗
PubMed1991

Antitumor effects of dopaminergic blockers in mice bearing Ehrlich tumors.

We determined the effect of 13 days of treatment with 2.0 mg/kg haloperidol, 30.0 mg/kg metoclopramide or 4.0 mg/kg domperidone on the number of tumor cells of mice bearing Ehrlich ascites carcinoma. The three dopaminergic blockers significantly reduced the number of tumor cells of experimental mice. The mean +/- SEM number of tumor cells x 10(6)/ml saline lavage was 25.5 +/- 5.9 for the haloperidol group, 36.8 +/- 4.7 for the metoclopramide group, 25.3 +/- 3.5 for the domperidone group and 54.0 +/- 9.0 for the control mice (treated with 0.9% NaCl). In a second experiment, treatment with 0.5 and 2.0 mg/kg haloperidol showed that the antitumor effect of this drug was dose dependent. The possible mechanisms underlying these results (such as an increase in prolactin levels or a direct action of these drugs on lymphocytes) are discussed in light of the specific pharmacological properties of each dopaminergic blocker.

Analysis of Variance↗
PubMed1978

X-ray scatter data for diagnostic radiology.

The ratio of the scattered to the total X-ray fluence (scatter fraction) at the centre of the image plane for X-rays transmitted through polystyrene phantoms has been measured for X-ray energies of 32 and 69 keV, X-ray beam diameters from 4 to 40 cm, phantom thicknesses from 5 to 30 cm and phantom-to-image-plane separations from 0.3 to 40 cm. The experimental values for this ratio have less than a 10% variation for these two X-ray energies and the experimental data show good agreement with Monte Carlo calculations and available experimental results for low atomic number materials. Based on these results, simple curves are generated which give estimates (+/- 10%) of the scatter fraction for all combinations of the geometric parameters encountered in diagnostic radiology.

Models, Biological↗
PubMedDate not supplied

Calibration of ophthalmic applicators at NIST: a revised approach.

A revised approach to the problem of measuring a surface-absorbed dose from beta-particle-emitting ophthalmic applicators is presented. The technique chosen employs an extrapolation chamber equipped with a 4-mm-diam collecting electrode to make current measurements at air gaps from 0.08 to 0.20 mm at 0.02-mm intervals. These data yield a linear relationship between current and air gap, the slope of which is used to determine average surface-absorbed-dose rate over the central area of the source. For additional information about the distribution of the activity over the source surface, autoradiographs using calibrated radiochromic dye films are analyzed to map the dose-rate profile across the surface of the applicator. Experiments varying several parameters of the extrapolation chamber measurement, including collecting electrode area, voltage gradient, range of air gaps used, and entrance foil material, are described. Also treated are calibrations of, and a description of the use of, radiochromic dye films for source profiling. Experiments for determining correction factors for the extrapolation chamber measurements are described, and an assessment of the uncertainties associated with these measurements is given.

Autoradiography↗