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Biomedical subjects

D Ducassou

Publications and source records attributed to D Ducassou.

At least 109 records · Page 6Linked to original sources
PubMed1978

Comparative results of 99mTc-pertechnetate scintigraphy and computerized tomography after contrast injection in cerebral pathology.

Fifty-six patients presenting acute cerebral ischemia were investigated by means of 160 CT and 90 RN scans. CT was positive before contrast injection in 90% of cases. A total of 120 CTs were done before and after contrast injection. Only 31% of the ischemic areas were enhanced. Out of 90 RN scans, 50 showed localized uptake. The peak of scintigraphic detection was found on the 15th day of evolution, while enhancement at CT was more frequent between the 15th and 21st days. For the hematomas (13 cases) detection by RN scan depends on the size of the lesion. Among the 47 patients presenting cerebral tumor, the RN uptake depends above all on the intensity of the BBB lesion. RN uptake and CT enhancement both show the same blood-brain barrier disturbance.

Brain↗
PubMed1978

[Importance of measuring blood volume by an isotope method in essential hypertension].

Measurement of the blood volume in cases of essential hypertension has shown a negative correlation with increase in blood pressure. We have been able to distinguish a group of moderate hypertensives who are hypervolemic, and whose systemic effect is more marked than in the moderate hypovolemic type. Such cases respond poorly to single drug therapy with beta blockers, but well to diuretics. The authors propose a general treatment scheme for essential hypertension: single therapy (beta blockers or diuretics) in mild cases of hypertension; single therapy by diuretics in the moderate types with the increased volume; single therapy by beta blockers in the moderate types with low volume, multiple treatment with the drugs together in cases of severe hypertension.

Adolescent↗
PubMed1977

[Scintigraphy using Technetium 99 m pyrophosphate in detection of bone metastasis of breast cancers. Analysis of 310 examinations].

Three hundred and ten bone scintigraphies were carried out in patients with a carcinoma of the breast. The results of these studies were compared not only with radiological findings but also the clinical and paraclinical course of the patients, the period of observation being between 8 and 44 months. Amongst the scintigrams in which no abnormality was detected, approximately 3.3% were obtained in patients with osteolytic metastases, the majority of these patients also having a rapidly growing primary tumourmamongst the patients with zones of hyperfixation and, at the same time, non-fixing metastases, 14/22 diedvery rapidly with diffuse bone metastases, this confirming the notion of poor prognosis in this "false negative" group. 11.3% of the abnormal results involved patients who showed no bone lesions more than 6 months after radio-isotopic examination "false positives". Of these, 12/18 were single lessions (41%). 14% of examinations carried out on a routine basis demonstrated metastases for which clinical and/or radiological confirmation was obtained only 2 to 9 months later.

Bone Neoplasms↗
PubMed1977

[Metyrapone test and plasma hormone estimations (author's transl)].

The usual metyrapone test based on the determination of the urinary steroid levels after ingestion of the product is relatively difficult to use because of its duration. In order to simplify this test, a comparative study was carried out with thirty subjects, 24 of whom were normal, by measuring their plasma hormonal levels by radioimmunoassay for ACTH, cortisol and aldosterone and by radiocompetition after extraction by carbon tetrachloride for the 11-desoxycortisol (S compound). The results show a parallel between the variation of the urinary steroid levels and the variations of plasma hormone levels during the first 24 hours of the test. Therefore, measuring the levels of ACTH, S compound and cortisol in the plasma before the ingestion of metyrapone and 24 hours afterwards seems simpler to carry out and accurate enough to test the integrity of the feed-back system between hypothalamus, pituitary and adrenal glands.

Adrenal Cortex Hormones↗
PubMed1976

A new stannous agent kit for labelling red blood cells with 99TCM and its clinical application.

99Tcm is chosen for labelling erythrocytes for vascular imaging to take advantage of the physical properties of the radionuclide. A new procedure is described which belongs to the category of pre-treatment methods using a kit. Stannous pyrophosphate is the specific reducing reagent. The technique is easier than already published methods: it consists of adding the above reagent to 2 ml. of heparinized blood, waiting five minutes and discarding the serum after centrifugation, then adding the radioactivity required as 99TcmO4. Labelling yield is superior to 95 per cent. The influence of technetium concentration of the pertechnetate solution on the labeling yield is evaluated and compensated by a slight adjustment of tin concentration when necessary. In vitro and in vivo stability studies show that 99Tcm-labelled red cells are suitable for determination of red cell volume, spleen and placental imaging, particularly in emergencies and in paediatrics.

Blood Volume Determination↗
PubMed1975

[Unusual isotope scanning aspects of hot thyroid nodules: diagnostic problems].

The classical picture of development of the "hot" nodule, which takes into account at the same time fixing or non-fixing nature of healthy perinodular tissue and the clinical condition of the patient fails to explain certain biological and scintigraphic findings. The authors discuss problems related to scintigraphy which they encounter in the course of the examination. In 174 stimulation tests carried out, 12 resulted in hypofixation of the isotope in the nodule, scintigraphy being carried out in three patients using 99-mTcO4 spontaneous reactivation of healthy tissue was seen in 5 patients. In the light of the cases reported, it would appear that the scintigraphic picture of the "hot" nodule is more in favor of a duality between the latter and healthy tissue with respect to iodine than of a hypersensitivity to TSH. In the 12 inhibition studies carried out, 3 showed the persistence of a contralateral shadow. Finally, on five occasions histological examination of the operative specimen showed the presence of neoplastic change, in two cases within the "hot/ nodule.

Adenocarcinoma↗