Search PubMed⌕ Search

Biomedical subjects

A Veyre

Publications and source records attributed to A Veyre.

At least 91 records · Page 5Linked to original sources
PubMed1981

Automatic construction of pulmonary functional images.

Dynamic study of regional ventilation of Xenon-133 with a gamma camera requires the medical interpretation of many analog scintigraphic images and time-consuming curve analysis. We have developed a program for the immediate creation of two functionally digitalized images by minicomputer which collects the data from the whole study. These images are constructed by assigning a value to each pont which depends upon the dynamic phenomenon. The program automatically computes the working files of the dynamic acquisition, performs the background subtraction, and delineates the boundaries of the lungs using isoactivity lines. Then the functional images of transit time and clearance of the radioactive gas in the alveoli are reconstructed. This processing takes less than 1 min and allows both time sharing and enhancement of interpretation.

Computers↗
PubMed1981

Myocardial emission tomography with thallium-201. Value of multiple and orthogonal sections in the study of the myocardial infarction.

The usefulness of transverse, sagittal, and frontal tomographic images was assessed in the study of the myocardium labelled with thallium-201. In a series of 20 patients with myocardial infarcts in various locations documented by clinical, electrocardiographical, and biochemical data in 15 cases and uncertain diagnosis in 5 cases, the sections reconstructed from 32 views obtained with a rotating scintillation camera were compared to the conventional views. Quantitatively, the mean myocardium-to-background activity ratio improved significantly from 1.60 to 2.57 (p less than 0.001); qualitatively, the presence, site, and size of the defect were more easily determined on the sections and generally showed a sharp contrast to the normal tissue; transverse sections enabled us to explore the anterior infarcts, but sagittal or frontal views were required for inferior locations. The tomographic exploration was normal in only patient whose diagnosis was uncertain. These results suggest that three-dimensional emission tomography can improve both detection and quantification of the myocardial infarct.

Humans↗
PubMed1981

[Normal pressure hydrocephalus. Pre- and postoperative study of 56 cases (author's transl)].

56 patients considered to have a low pressure hydrocephalus were treated between 1973 and 1979 by a ventriculo-atrial shunting, using a medium pressure Holter valve. Apart from a standard clinical examination, these patients underwent a pneumoencephalography, an isotope cisternography, a measurement of ventricular pressure, and a determination of the C.S.F. resistance to flow by mean of an infusion test. A 6 months to 5 years follow up study showed that the operative result could be considered a success in 47%, a failure in 53%. No precise correlation could be found between any clinical sign or response to investigations, and the functional results. However, an early and really unsteady gait, an important ventricular enlargement without image of cortical atrophy, and the presence of pressure waves on I.C.P. recordings, seem to be frequently associated with good results.

Adolescent↗
PubMed1979

Transverse CAT of the myocardium with 201 T1.

A new computerized axial tomographic (CAT) scanner (J&P Tomoscanner) which enables the transverse section viewing of any organ labelled by one of the monophotonic gamma-ray emitting racers commonly used in Nuclear Medicine, has been recently commercialized. Its abilities in visualising the 201 T1 labelled myocardium are evaluated with normal hearts and patients with documented infarctions. Positive results have been obtained, allowing an interesting approach to the estimation of the anatomical extent of necrosis.

Heart↗
PubMed1978

[Value of myeloscintigraphy in the detection of intraspinal compressions].

The authors report their experience of myeloscintigraphy summarizing the 120 examinations made during the years 1975 and 1976, in the department of rheumatology of the regional hospital centre of Clermont-Ferrand. The technique uses serum labelled with technetium 99 introduced by the lumbar route. Schematically 3 pathological patterns can be determined : complet block, segmental block, and partial block. The examination is particularly reliable at the dorsal and high lumbar levels, where only one "false negative" was found, and even that debatable. In this situation it has a valuable role in regard to both the presence and the level of a compression. In the cervical and low lumbar levels, its reliability seems definitely inferior, especially in the case of lateral disc herniations. Tolerance has always been excellent whatever the age of the patient. We have thus an investigation that is simple and well tolerated, and its valuable role in the early detection of myelo-radicular compressions should assure it a place of choice alongside other methods of paraclinical investigation of the spinal canal.

Adolescent↗
PubMed1975

[Systematic study of sequential salivary gland scintigraphy during rheumatoid arthritis and collagenosis. Apropos of 150 examinations].

Sequential salivary scintigraphy has been practised systematically in 130 patients hospitalized in a rheumatology unit. These patients were suffering from typical, classical rheumatoid arthritis, rheumatoid arthritis with high positivity for anti-nuclear antibodies, clearly defined polyarthritis, systemic scleroderma, other types of collagenosis, forms of inflammatory polyarticular rheumatism other than rheumatoid arthritis and collagenosis, and from different degenerative diseases. The scintigraphic anomalies were divided in three stages according to a personal classification. Nine patients presented a patend Gougerot-Sjögren syndrome. All of them had abnormal or very abnormal scintigraphy. However, the patients with classical rheumatoid arthritis without signs of the Gougerot-Sjögren syndrome, also showed a high frequency of isotopic anomalies that were equally severe. These were clearly connected only with the particular diagnosis (with classical rheumatoid arthritis, but not with clearly defined polyarthritis or collagenosis). No other direct relationship could be established between these diseases and the clinical, radiological, laboratory, or therapeutic aspects of the case. On the other hand, they were often associated with a reduction in lacrymal and salivary secretion. These isotopic studies, in combination with other findings shed a new light on the Gougerot-Sjögren syndrome, taking into account the diffusion of the exocrine lesions and of the contributions of the most modern methods of investigation.

Antibodies, Antinuclear↗
PubMed1975

[Resistance in cerebrospinal fluid flow in normal pressure hydrocephalus].

C.S.F. resistance to flow (Rf) was measured in 24 patients by the mean of a constant infusion manometric test, and the results were compared with those of pneumo-encephalography and isotope cisternography. It is concluded that Rf is constantly elevated in patients with normal pressure hydrocephalus, is at least as reliable as the two other tests and therefore provides a really valuable aid to the identification of the patients to be shunted.

Alzheimer Disease↗
PubMedDate not supplied

Brain uptake of labelled adiphenine in rats.

This study describes the behaviour of a dual labelled drug, adiphenine, in the rat brain. Macroautoradiographies show images of the brain at different times after injection. Some of the tissue metabolites are identified at the brain level and the passage of the blood brain barrier is compared with tritiated water. The obtained data give very interesting indications on the blood brain distribution and on the metabolism at the brain level. Different techniques of high pressure liquid chromatography, macro- and histoautoradiographies allowed us to visualize how the drug is fixed on cerebral structures, giving indications on its mechanism of action. This fat soluble compound freely crosses the normal blood brain barrier and if labelled with the appropriate emittor could be very useful in nuclear medicine to obtain imaging of the brain.

Animals↗
PubMedDate not supplied

Adiphenine plasma levels and blood-brain barrier crossing in the rat.

Adiphenine was administered in 3H-labelled form in doses of 15 mumole/kg intravenously to male Wistar rats. Plasma and brain levels of the unchanged drug were measured. The elimination of the 3H-labelled compound from the plasma was monophasic with a half-life of 13 minutes. The unchanged drug was detectable in the plasma for 30 minutes after the injection. The time course of brain levels of unchanged drug paralleled that found in the plasma with a half-life of 9 to 12 minutes. In all experiments, brain and plasma levels of unchanged adiphenine correlate highly.

Animals↗
PubMedDate not supplied

3D modeling in myocardial 201TL SPECT.

A method to model the left ventricular myocardium in thallium-201 Single Photon Emission Computed Tomography (SPECT) is presented. This method is based on the fitting of the morphological skeleton of the left ventricle to a truncated bullet. This automatic approach would provide a more reproducible visualization of the organ for clinical applications.

Computer Graphics↗
PubMedDate not supplied

Mechanism of uptake of technetium-tetrofosmin. II: Uptake into isolated adult rat heart mitochondria.

BACKGROUND: 99mTc-labeled tetrofosmin is a new myocardial imaging agent that gives stable heart uptake. However, little is known about the mechanism of uptake in heart tissue. The aim of this study was to assess the factors responsible for the uptake and retention of 99mTc-labeled tetrofosmin in isolated heart mitochondria. METHODS AND RESULTS: Mitochondria were isolated from adult rat heart tissue with competent metabolic function (i.e., respiratory control ratio of 3 and adenosine diphosphate/oxygen ratio of 2) for succinate oxidation. Intramitochondrial volume measured by the distribution of 3H-water and 14C-sucrose was 1.16 +/- 0.23 microliters/mg protein (mean +/- SD). In the isolated mitochondria, uptake could be demonstrated within 30 seconds of addition of oxidative substrate, but adenosine triphosphate alone did not stimulate marked uptake. Uptake was proportional to the amount of mitochondrial protein over a range of 0.2 to 3 mg protein but independent of Tc-labeled tetrofosmin concentration over a range of 0.4 to 200 pmol/L (0.1 to 50 microCi/ml). The presence of Tc-labeled tetrofosmin had no effect on the oxidative capability of the mitochondria. Use of the mitochondrial uncoupler 2,4-dinitrophenol caused release of 92% of radioactivity. Addition of Ca2+ to the mitochondria to partially depolarize the membrane resulted in partial release of activity. Application of the Nernst equation to the uptake data gave rise to a value of -163 mV for the mitochondrial membrane potential. CONCLUSION: It was concluded that the accumulation of 99mTc-labeled tetrofosmin by the mitochondria is related to their ability to transduce metabolic energy into electronegative membrane potential.

Animals↗
PubMedDate not supplied

Biodistribution and metabolism in rats and mice of bucromarone.

The metabolism and disposition of bucromarone, labeled with 14C on the chromone group, has been investigated in C3H mice and Wistar rats. In separate experiments, animals received 4.4 mmol/kg, iv or po, [14C]bucromarone hydrochloride or succinate. More than 90% of the administered radioactivity was excreted in bile, after iv and po administration. Less than 5 min after iv injection, radioactivity concentrated in all tissues, and blood concentration became very low as compared with its initial level. After po administration, no more than 10% of the dose was incorporated in the tissues. The discrepancy between the high biliary excretion and the low tissue and blood concentration after po administration suggested that bucromarone was well absorbed through the gastrointestinal tract; but after liver uptake, drug and its metabolites were excreted in the bile, less than 10% being distributed into the extrahepatic blood. Comparison of the iv and po areas under the plasma 14C-radioactivity concentration-time curves indicated a poor bioavailability of the molecule after po administration. Analysis of the radioactivity content of bile showed that bucromarone was extensively metabolized after both administration routes. Unchanged bucromarone and three main metabolites, monodesbutylbucromarone, didesbutyl bucromarone, and 2-(3-5-dimethyl-4-hydroxybenzoyl) chromone, amounting to 85% of the bile radioactivity, were identified by HPLC and mass spectrometry. These findings are consistent with a dealkylation of the N-dibutyl group, yielding potential pharmacologically active metabolites monodesbutyl and didesbutyl bucromarone.

Administration, Oral↗
PubMedDate not supplied

[Pelvic pain of venous origin].

Although the causes of chronic unrecognized pelvic pain are multifactorial, most investigators observe circulatory disturbance as being a main etiological factor, in particular if the patient has a retroverted uterus. We examined 50 patients who were diagnosed to have this condition, comparing data obtained by hysterophlebography and laparoscopy, with complementary but sometimes differing results, which, in any event, are not sufficient to establish the diagnosis, thereby leading us to offer a method to measure uterine blood flow using a radioisotope of Xe 133. It is certain that better understanding of the pathophysiology of this disorder would provide an improved therapeutic approach. Here too, the value of laparoscopy must be emphasized, because of its contribution both to positive as well as differential diagnosis.

Diagnostic Imaging↗