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Biomedical subjects

F Prigent

Publications and source records attributed to F Prigent.

At least 55 records · Page 3Linked to original sources
PubMed1987

Comparative methods for quantifying myocardial infarct size by thallium-201 SPECT.

Maximum-count circumferential profile analysis of 201TI single photon emission computed tomograms (SPECT) was employed to quantify infarct size (15) in ten dogs with acute closed chest coronary occlusion (seven left anterior descending coronary artery and three left circumflex coronary artery) who underwent rest-redistribution 201TI SPECT. The extent of hypoperfused myocardium was calculated as a percentage of slice mass on rest-redistribution 201TI SPECT. Pathologic IS was determined by triphenyl tetrazolium chloride (TTC) staining. On each tomogram, SPECT IS was defined as the % of the maximum-count circumferential profile points falling below normal. To calculate total LV infarct size, slice ISs were added to one another after each was multiplied by a coefficient K that reflected the contribution of that slice to the total left ventricular mass. K was derived from an observed relationship in normal dogs between slice fractional distance from the apex and either its actual weight, its geometric SPECT area, or its count-based SPECT area, the assessment of which was independent of edge detection. Using any of these algorithms, there was a high linear correlation between the tomographic and TTC IS. A similar algorithm was also developed from tomograms of eight normal patients. These data offer promise for the clinical noninvasive assessment of the extent of hypoperfused myocardium.

Algorithms↗
PubMed1986

Noninvasive quantification of the extent of jeopardized myocardium in patients with single-vessel coronary disease by stress thallium-201 single-photon emission computerized rotational tomography.

In 22 patients with single-vessel coronary artery disease and no history of infarction, stress Tl-201 rotational tomography was used to quantify the extent of jeopardized myocardium. The vertical long- and short-axis tomograms were quantified by means of maximum-count circumferential profile analysis. The scintigraphic extent of jeopardized myocardium was expressed as the percentage of profile points falling 2.5 standard deviations below a previously established mean normal profile and was correlated to a quantitatively expressed angiographic extent of jeopardized myocardium. The extent of jeopardized myocardium varied from 1% to 55% by tomography and 8% to 50% by angiography and correlated with an r = 0.79 and a 10% standard error of the estimate. Defect intensity, reflecting the mean depth by which the abnormal points fell below the normal value of greater than or equal to 10%, was 100% specific for a coronary stenosis of greater than or equal to 70%. In conclusion, this study demonstrates that: patients with single-vessel disease have highly variable extents of hypoperfused myocardium defined by Tl-201 tomography and coronary arteriography, there is a fair relationship between angiographic jeopardy score and perfusion defects by Tl-201 tomography during exercise, and Tl-201 tomography may be used to noninvasively determine the extent of hypoperfused myocardium in coronary artery disease.

Aged↗
PubMed1986

Quantification of myocardial infarct size by thallium-201 single-photon emission computed tomography: experimental validation in the dog.

To evaluate the potential advantages of thallium-201 (201T1) single-photon emission computerized tomography (SPECT) to assess myocardial infarct size in the experimental animal, six normal dogs and 14 dogs with 6 to 8 hr closed-chest coronary occlusion (eight left anterior descending and six left circumflex) were studied. Ten minutes after intravenous administration of 2 mCi of 201T1, 30 projections were obtained over 180 degrees. The dogs were killed and their hearts sliced and stained by triphenyl tetrazolium chloride (TTC). Pathologic infarct size was calculated for each slice and for the entire left ventricular myocardium as percent weight. Tomograms were quantified by automatically generating maximum-count circumferential profiles, which were compared with normal limit profiles derived from the six normal dogs. Tomographic infarct size was defined as the percentage of circumferential points falling below normal for each tomogram. SPECT and TTC infarct size on 71 slices correlated highly (mean +/- SD 27.9 +/- 23.4% and 26.7 +/- 25.3%, respectively; r = .93, p less than .001, SEE = 9.4%). To determine SPECT infarct size as percent total left ventricular myocardial weight, infarct sizes from each slice were added to one another after each was multiplied by a coefficient that reflected the contribution of that slice to the total left ventricular weight. SPECT and TTC infarct size for the entire left ventricle correlated closely (mean +/- SD 20.5 +/- 7.6% and 19.3 +/- 8.3%, respectively; r = .86, p less than .001, SEE = 4.5%). It is concluded that 201T1 SPECT is a valid method for the noninvasive assessment of experimental myocardial infarct size.

Animals↗
PubMed1986

[Cutaneous pigmentation induced by minocycline: 2 cases].

Two new cases of cutaneous pigmentation induced by minocycline are reported, in addition to the 38 cases collected in the literature. Our first case was a 50-year old man with a history of multiple orthopaedic operations for injuries sustained in road accidents. Arthritis of the elbow, probably of bacterial origin, was treated with cephalexin and gentamicin, followed by minocycline 300 mg/day. After a total dose of 60 g of minocycline had been reached, a bluish-grey pigmentation was observed on the internal aspect of the left tibia and on the scars left by the orthopaedic operations. Subsequently, lenticular lesions of the hands developed, together with a blue area on the palate. Our second case was an 18-year old girl who presented initially with nodulo-cystic acne. Minocycline 200 mg/day was prescribed, then withdrawn on account of dizziness; no pigmentation was observed. The acne was cured after 7 months of treatment with 13-cis-retinoic acid in doses of 30 mg/day (for a patient's weight of 50 kg). A second course of minocycline 100 mg/day was prescribed; after a total dose of 3 g all the acne scars had become pigmented. A pathological study performed in the first case confirmed the data found in the literature: light microscopy displayed hyperpigmentation of the basal layer of the epidermis with Masson's silver stain, and an intrahistiocytic pigment coloured by Turnbull's stain; electron microscopy showed an increase in melanosomes within the basal keratinocytes, and a pathological accumulation of pigment in the dermis in the form of electron-dense granules usually surrounded by a membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗