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Biomedical subjects

A G Jones

Publications and source records attributed to A G Jones.

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

Non calculous cholecystitis: an 8 year review of cases treated by elective cholecystectomy.

From a total of 248 cases of cholecystectomy, 36 were found to be without stones. These cases of acalculous cholecystitis have been reviewed with regard to signs, symptoms and radiological investigations. The complications of operative treatment have been documented and the etiology of the condition discussed. As a result of favourable outcome of operative treatment in these patients, it is suggested that surgery should be considered even in the absence of positive radiological findings at an earlier date.

Adult↗
PubMed1978

Frankie Wild's hut.

Explore the source record for details and available documents.

Antarctic Regions↗
PubMed1978

Tantalum-178--a short-lived nuclide for nuclear medicine: production of the parent W-178.

The physical decay characteristics of the short-lived radionuclide Ta-178 (half-life 9.3 min) appear to be suitable for use in conjunction with low-energy detection systems such as the multiwire proportional camera. This camera is inefficient for emissions with energies greater than 100 keV. The gamma-ray spectrum of Ta-178 is dominated by the characteristic hafnium x-rays (55--65 keV), emitted as a result of electron-capture decay. The parent nuclide, W-178 (half-life 21.7 d), was produced in the Michigan State University cyclotron by proton bombardment of stacked natural tantalum-foil targets. Optimum production was found to occur with an incident proton energy of 34 MeV at an effective activity of 1.1 mCi/muA-hr per MeV of target thickness. Tungsten-178 was chemically separated from the Ta foils with a yield of 98%.

Particle Accelerators↗
PubMed1978

Tantalum-178--a short-lived nuclide for nuclear medicine: development of a potential generator system.

We describe a chemical separation that may form the basis of a generator system for the short-lived radionuclide Ta-178 (T 1/2 = 9 min). The parent nuclide W-178 (T 1/2 = 21.7 days) is loaded on an anion-exchange column and the daughter eluted with a mixture of dilute hydrochloric acid and hydrogen peroxide. The yields of tantalum and the breakthrough of the tungsten parent as a function of the eluting conditions are discussed, and preliminary animal distribution data are presented for various treatments of the eluant solution.

Animals↗
PubMed1977

Quantification of flow in a dynamic phantom using Rb81-Kr81m, and a Nal detector.

Blood flow can be measured by monitoring the count rate of Krypton-81m after its parent, Rubidium-81 (a potassium analogue), has been deposited in the tissue. The steady-state Kr-81m count rate reflects both production by decay of Rb-81 and washout due to blood flow. Its use is theoretically superior to that of Xenon-133 for quantification of blood flow (cc/min per 100 gm) since: (1) multiple flow measurements can be obtained from a single arterial injection, (2) flow-dependent changes in the count rate of Kr-81m provide a steady-state measure of specific flow, and (3) errors due to uptake in fat are eliminated. The count rate of Kr-81m was measured as a function of flow in a dynamic phantom with a NaI crystal, suing both pure cyclotron-produced Rb-81 and commercially available samples with as much as 25% contamination from Rb-82m. The phantom was calibrated by measuring the flow-rate constants with Xe-133. No significant difference was found between the flow-rate constant measured with three pure samples. The ratio of the zero-flow Kr-81m count rate to the rate observed in the presence of flow showed excellent correlation with calibrated flow over a range of rate constant from 0 to 0.02 sec (-1). This study suggests that regional specific flow can be measured in vivo with currently available Nal detecting systems after the intra-arterial injection of Rb-81.

Blood Flow Velocity↗
PubMed1977

Radionuclide left ventriculography with the slant hole collimator.

A 30 degrees slant-hole collimator was used during radionuclide ventriculography of the cardiac blood pool to improve imaging of the heart in both the modified left anterior oblique (MLAO) and right anterior oblique (RAO) views. In the MLAO view, with the holes slanted caudally, good separation between the left atrium and left ventricle was achieved, and the septum was displayed without foreshortening. In the RAO view with the collimator flat against the chest there was better resolution of the cardiac apex. The results of ejection fraction and wall motion analysis in these patients correlated well with contrast ventriculography (r=0.94). Combination of the slant-hole collimator, in vivo red blood cell labeling with stannous pyrophosphate, simultaneous collection of all phases of the cardiac cycle, and cine mode display, provide a practical system for the noninvasive measurement of left ventricular performance parameters.

Coronary Disease↗
PubMed1976

Bone scanning: radionuclidic reaction mechanisms.

One of the major successes of nuclear medicine in recent years has been the clinical utility of the 99mTc-labeled bone-imaging agents. This article is concerned with the evidence available for the mechanisms by which these and other such radiopharmaceuticals localize at sites in the skeleton.

Animals↗
PubMed1976

Double-labeling of experimental acute myocardial infarcts with 113mIn- and 99mTc-EDTMP.

The feasibility of double-labeling of acute myocardial infarcts with 113mIn-EDTMP [ethylenediaminetetra(methylene phosphonic acid)] and 99mTc-EDTMP was evaluated. The in vitro distributions of these tracers in acute myocardial infarcts in dogs and their selectivities for infarcted versus noninfarcted myocardium were compared. Both tracers concentrated in acutely infarcted myocardium, and there was excellent correlation between their uptakes (r = 0.88). They also provided complete separation between infarcted and uninfarcted tissue, as checked by histology. Accordingly, these agents show promise for the multiple-labeling of acute myocardial infarcts in experiments to determine the natural course of myocardial infarction and the efficacy of therapy aimed at limiting infarct size. In addition, 113mIn-EDTMP may be useful for serial scintigraphy during the early phase of acute myocardial infarction when the damage may be, at least to some extent, reversible.

Animals↗
PubMed1975

Radionuclide immunoglobulin lymphangiography: a case report.

Iodine-131-labeled immunospecific gamma globulin derived from immunization of rabbits with F antigen, a tumor associated antogen in Hodgkin's disease, has been utilized for intralymphatic infusion in a patient with known recurrent Hodgkin's disease inthe inguinofemoral and pelvic regions. Rectilinear scanning successfully delineatedthe tumor masses, and external monitoring showed retention of activity in the tumor sitesover an 8-day period.

Adult↗
PubMed1975

113mIn-labeled bone scanning agents.

Phosphonate analogs of EDTA and DTPA, in which the acetic acid has been replaced by methylene phosphonic acid (DTPMP and EDTMP) have been labeled with 113mIn and evaluated as skeletal imaging agents. Organ distribution in rats, blood clearances in dogs, and images obtained in rabbits are presented. 113mIn-DTPMP exhibits the desired characteristics to supplant 85Sr and other bone-seeking radiopharmaceuticals used in areas of the world where 99mTc is not routinely or regularly available.

Animals↗