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Biomedical subjects

D Ducassou

Publications and source records attributed to D Ducassou.

At least 73 records · Page 4Linked to original sources
PubMed1984

Comparative pharmacokinetics of [65Zn]zinc sulfate and [65Zn]zinc pantothenate injected intravenously in rabbits.

The pharmacokinetics of zinc sulfate were compared with those of a new zinc salt, pantothenate, in rabbits. Each salt was administered at a dosage of 3.3 microCi of zinc-65/kg of body weight. The measured pharmacokinetics of the two compounds responded to a two-compartment open model. The urinary elimination of the two salts was similar, as was their localization in the skin and fur, but zinc pantothenate was fixed by the liver to a lesser extent than was zinc sulfate.

Animals↗
PubMed1984

Routine studies of swallowed radionuclide transit in paediatrics: experience with 400 patients.

Scintigraphic studies of swallowed 99m Tc-sulphur colloid mixed with a few millilitres of liquid, performed on 400 paediatric patients of all ages, allowed visualisation of foregut function and measurement of oesophageal transit time and gastric emptying proportions. This non-invasive and physiological procedure requires a standard gamma camera with computing facilities and was performed as an outpatient routine. It proved very effective for the detection of gastro-oesophageal reflux and aspiration of refluxed liquid in patients of all ages but especially in neonates. The relevance of these scintigraphic results to oesophagitis, repeated respiratory problems, cyanotic and apnoeic spells and alternative methods of investigation is described.

Apnea↗
PubMed1984

Radionuclide angiocardiography in the diagnosis of congenitally corrected transposition of the great arteries.

Congenitally corrected transposition of the great arteries (CTGA) may constitute a pitfall for interpretation of radionuclide angiocardiography, since the two anatomic discordances cancel each other from a physiologic point of view. However, the unusual shape of the ventricles (due to ventricular discordance) and the relative position of the great arteries (due to transposition) can allow a clear scintigraphic diagnosis, especially for CTGA with mild or absent associated congenital anomalies. Five cases are described. Gated cardiac blood pool imaging is particularly helpful since it permits multiple views, allowing a more detailed study of the scintigraphic signs.

Adolescent↗
PubMed1984

Single photon emission computed tomography (SPECT), planar scintigraphy, and transmission computed tomography: a comparison of accuracy in diagnosing focal hepatic disease.

A prospective evaluation of conventional planar scintigraphy (PS), single photon emission computed tomography (SPECT), and transmission computed tomography (TCT) was performed in 98 patients with suspected focal hepatic disease (FHD). The three examinations were performed on the same day. TCT had slightly higher sensitivity (91%) and specificity (96%) than either PS or SPECT. The sensitivity and specificity of TCT was also higher than that of the combination of PS and SPECT, which was more accurate than either radionuclide technique alone, with a sensitivity of 85-87% and a specificity of 90%. These differences were not statistically significant. However, receiver operating characteristic (ROC) analysis showed that the performance of TCT was significantly better. The ROC curves also showed, without statistical significance, that SPECT appears to have better diagnostic accuracy than PS and that it seems desirable to complement SPECT imaging with PS views, to reduce the number of equivocal results.

Adult↗
PubMed1984

Radionuclide studies in postoperative evaluation of the Fontan procedure.

Radionuclide studies were performed on 12 patients who had had a Fontan operation for cyanotic congenital heart disease, six of whom had undergone a prior palliative Glenn procedure. The patients without prior Glenn anastomoses were studied by radionuclide first-pass angiocardiography, using a right antecubital vein injection of 99mTc pertechnetate. The patients with Glenn anastomoses required two injections, one by femoral vein to study the Fontan procedure, using bolus injection of 99mTc pertechnetate or microspheres, and the second by right antecubital vein to study the Glenn anastomosis and right lung, using a bolus of microspheres. Gated cardiac blood-pool scintigraphy was used to measure right atrial and left ventricular ejection fraction in three patients. In nine patients, contrast angiography confirmed that these techniques allowed recognition of residual right-to-left shunts, right atrial stasis, right atrial outflow obstructions, left ventricular dysfunction, and right lung arteriovenous fistulas. Noninvasive radionuclide methods seem to be dependable in the postoperative evaluation of patients after the Fontan procedure. First-pass angiocardiography is most helpful in evaluating the dynamics and distribution of blood flow, especially the right atrial output, and gated blood-pool scintigraphy offers a better evaluation of right atrial and left ventricular contraction, so both supply complementary information.

Adolescent↗
PubMed1984

Quantitative analysis of left-ventricular function using gated single photon emission tomography.

We describe a quantitative method that measures segmental motion of the left ventricle, using tomographic slices obtained by gated single photon emission tomography (GSPECT). These slices contain the major axis of the left ventricle and are presumed to show wall motion directed towards a center of contraction. Values of parameters describing segmental wall motion in GSPECT were obtained from 61 patients, who received a left cardiac catheterization 1 hr later. These values were compared with results of similar calculations applied to data from contrast ventriculography. We conclude that GSPECT allows a detailed and quantitative, noninvasive study of wall motion of all left ventricular segments, with high inter- and intraobserver reproducibility.

Angiocardiography↗
PubMed1984

Intraperitoneal injection of technetium-99m sulfur colloid in visualization of a peritoneo-vaginalis connection.

Ten minutes after an intraperitoneal infusion of Tc-99m sulfur colloid, a gamma camera was used to obtain anterior abdominal views. This visualized a peritoneoscrotal communication in an 80-yr-old patient. He had developed extensive edema of the genitals and lower limbs after about 6 wk of continuous ambulatory peritoneal dialysis. At operation the communication was confirmed and closed. A repeat test verified the success of operation.

Aged↗
PubMed1983

Transient intense gastric fixation of 99mTc-MDP.

A case is described of reversible, intense gastric uptake of 99mTc-MDP in the fundal region of a patient with myeloma, while very little transient pulmonary fixation was seen. The significance of this unusual finding in terms of relevant blood chemistry, results of gastric biopsies, which failed to show metastatic calcification, and the drugs administered is discussed.

Aged↗
PubMed1983

Deconvolution analysis of radionuclide angiocardiography curves: problems arising from fragmented bolus injections.

Deconvolution analysis of radionuclide angiocardiography time-activity curves (TAC) in the cases of fragmented bolus injections was studied by using a new deconvolution technique based on the maximum a posteriori estimator. This method was first tested by simulation studies which showed its capability for accurate handling of deconvolution both for single and double peak input functions. These simulations have proved this technique to have advantages over a Fourier transform division method used with a low-pass filter. In patient studies, deconvolution of pulmonary TAC by superior vena caval TAC produced poor results in double peak (fragmented) bolus injections, compared with single peak bolus injections (SPBI). This discrepancy seems to be due to the fact that the postulates of linearity and invariance, on which deconvolution analysis is based, do not hold for the 'cardiopulmonary system' which extends from the superior vena cava to the lung. The differences between the model and the real system appear unimportant for SPBI. However, differences become apparent for fragmented bolus injections. Deconvolution analysis should be avoided with this type of input function in this cardiopulmonary system.

Aged↗
PubMed1983

[Effects of synthetic ACTH on plasma cortisol and aldosterone in neurosurgery].

Cerebral oedema, present or potential, is a predominant medical complication of neurosurgery. Its physiopathology and treatment can be in part linked to adrenal activity (aldosterone and sodium balance; cortisol and hormone treatments). In 25 non-comatose patients presenting with a tumoral or vascular neurosurgical condition, plasma cortisol and aldosterone levels were measured by radioimmunoassay, always at the same time (07 h), before any investigations or treatment were carried out, the patient being at rest. Cortisol levels were increased in more than half the patients (n = 14; 44.11 +/- 3.4 micrograms X 100 ml-1; p less than 0.001); aldosterone levels were high in one third of the patients (n = 8; 304.29 +/- 57 micrograms X ml-1; p less than 0.001). 17 of these patients were studied according to the protocol of the synthetic ACTH test during the first four days of their receiving 1 mg X 24 h-1 synthetic ACTH. The expected therapeutic effect on cortisol was not obtained in all cases, and the stimulation of aldosterone release was important and prolonged.

Adrenocorticotropic Hormone↗
PubMed1983

Pediatric esophageal scintigraphy. Results of 200 studies.

Esophageal transit of a small volume of watery liquid has been observed scintigraphically in 200 studies performed on patients aged between 6 days and 16 years. Qualitative information concerning esophageal morphology and function in the various phases of deglutition, and scintigraphic features of achalasia, stenosis, and other pathologies are described. Measured esophageal transit time and its normal variation, its relevance to the diagnosis of esophagitis, and the monitoring of treatment are discussed. This technique observing distinct deglutitions has proven a useful diagnostic tool. Its advantages and limitations are discussed in comparison with other methods.

Adolescent↗
PubMed1983

Cerebrospinal shunt flow in adults: radionuclide quantitation with emphasis on patient position.

Radionuclide quantitation of cerebrospinal fluid (CSF) flow through a ventricular shunt using a Cordis-Hakim valve was performed in 78 adults (138 studies). All remained supine for at least two hours before the study to avoid possible depletion of ventricular CSF. The absolute flow rate distinguished shunt adequacy from patency by defining flow of less than 0.1 ml/min. as abnormal. Measurements were performed with the patient first supine and then erect. When abnormal supine flow was the criterion of malfunction, all obstructions were detected but there were 6 false positives. When abnormal erect flow was considered, there were 5 false negatives. Abnormal flow in both supine and erect positions is a reliable indication of malfunction. The authors conclude that this technique is valuable for neurosurgical management of ventricular shunts.

Adolescent↗
PubMed1983

Radionuclide angiographic demonstration of systemic lung arterialization with arteriovenous fistulas.

Radionuclide angiography has diagnosed systemic arterialization of the right lung base in a patient presenting with a basal thoracic bruit. The bruit was due to high flow in the systemic artery and development of arteriovenous fistulas, confirmed by TCT scan and contrast aortography. But the parenchyma of the right lung base appeared normally aerated on the radiographic studies, and Xe-133 ventilation scintigraphy was normal. This case was therefore classified as systemic arterialization of lung without sequestration.

Adult↗
PubMed1982

[Kinetic study of indium-111 labelled platelets in idiopathic thrombocytopenic purpura (author's transl)].

Labelling platelets with 111 Indium-oxine has advantages over the conventional 51 Chromium method: labelling is more efficient and the radiations emitted almost exclusively consist of gamma-rays. Owing to these advantages, autologous platelets can be used for kinetic studies in patients with idiopathic thrombocytopenic purpura, even when thrombocytopenia is severe. 111 Indium labelling also provides accurate information on the sites of platelet destruction, which may help to predict the patient's response to splenectomy.

Blood Platelets↗