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Biomedical subjects

E Lebowitz

Publications and source records attributed to E Lebowitz.

18 recordsLinked to original sources
PubMed1986

Giant cell arteritis in a 20-year-old black man: a cause of intermittent calf claudication.

Giant cell arteritis in a young black man is an extremely unusual occurrence. A 20-year-old black man came for treatment of bilateral leg claudication that had been present for a 2-month period. His medical and angiographic evaluation led to an arterial biopsy that demonstrated giant cell arteritis. The patient was treated with corticosteroids and his condition has subsequently improved. Unusual variants of giant cell arteritis are discussed.

Adult↗
PubMed1977

Thallium-201 for medical use. Part 3: Human distribution and physical imaging properties.

Studies were undertaken to determine the biologic distribution of thallium-201 in man. The disappearance from the blood is extremely rapid and intracellular deposition is nearly immediate. The biologic half-time of thallium was measured by both the Brookhaven whole-body counter and the Donner whole-body scanner, with excellent agreement. The effective whole-body half-time of thallium-201 is about 57 hr. Concentration of activity was seen in the heart, kidneys, large bowel, and thyroid. The whole-body radiation dose is 0.21 rads/mCi.

Animals↗
PubMed1975

Thallium-201 for myocardial imaging. Relation of thallium-201 to regional myocardial perfusion.

Following intravenous administration, the myocardial concentration of tracer thallium-201, potassium-43, and rubidium-81 were determined in mice; thallium was present in the greatest concentration in the myocardium (2.08% compared 1.25% for potassium and 1.15% for rubidium at 10 minutes). The regional myocardial distribution of thallium-201 was determined in dogs under conditions of normal flow, and total occlusion, and compared with potassium-43 (r=0.97). The regional distribution of thallium-201 was compared to microspheres under conditions of partial occlusion and reactive hyperemia (r=0.97). Thallium-201 was evaluated in a series of phantom scans, which demonstrated that the low energy X-ray of thallium was suitable for imaging. These results suggest that thallium-201 can be used for the evaluation of the distribution of regional myocardial perfusion.

Animals↗
PubMed1975

Thallium-201 for medical use. I.

Thallium-201 merits evaluation for myocardial visualization, kidney studies, and tumor diagnosis because of its physical and biologic properties. A method is described for preparation of this radiopharmaceutical for human use. A critical evaluation of 201Tl and other radiopharmaceuticals for myocardial visualization is given.

Cesium Isotopes↗
PubMed1975

Thallium-201 for medical use. II: Biologic behavior.

Thallium-201 has been evaluated for myocardial imaging by determining its distribution and assessing its imaging properties. Organ distribution with time was studied in goats, chosen for their large size and easy operability. Myocardial imaging was performed in living and sacrificed goats and also in two anesthetized dogs, without infarction. Infarcts were made by ligature at open chest surgery on the goats and the infarcts subsequently confirmed histologically. The myocardium of normal and infarced, young and old goats was cut into blocks and the isotope distribution measured and compared with that in the lungs, liver, spleen, and kidney in normal goats. The renal medulla-to-cortex concentration ratio in goats was studied and is approximately five. The heart uptake exceeds 3% for 100 min whereas contiguous organs have less than one-half of the myocardial concentration, and blood clearance is rapid. One problem may prove to be inhomogeneity of uptake of thallium in the "normal" myocardium, showing a standard deviation of 1u% in a young goat and 29% in an old goat. In view of the good myocardial uptake, however, this work strongly suggests the trial 201Tl in patients.

Animals↗
PubMedDate not supplied

Investigation of 125I as an isotopic source for mammography.

An isotopic radiation source 125I was investigated for use in soft tissue radiaography, with particular attention to possible use in mammography for mass screening. Film sensitivities, exposure rates, absorbed doeses, contrast and resolution were determined, and compared to conventional x-ray units. It was found that contrast and resolution were comparable to 30 kVp x-rays (W anode) but that surface absorbed dose was reduced by a factor of two with 125I. These results experimentally verified the advantage to be obtained from monoenergetic radiations, which had been predicted from theoretical considerations by others. Duration of exposure was estimated to be between 4 and 12 sec with a 40 Ci source. The 60-day half life of 125I may necessitate its use in conjunction with an image intensification system or electron radiographic techniques, in order to preclude source replacement at inconveniently short intervals.

Female↗