An Automated Fluorescent Excitation Analysis System for Medical Applications

Kaufman, Leonard; Deconinck, Frank; Price, David C.; Guesry, Pierre; Wilson, Charles J.; Hruška, Branislav; Swann, S.; Camp, D.C.; Voegele, Alexis; Friesen, R.D.; Nelson, John F.

doi:10.1097/00004424-197605000-00009

Cited by 44 publications

(8 citation statements)

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“…Fluorescent excitation analysis and its use for assessing iodine concentration in the myocardium have been described. 9 The tissue samples were also assayed for radioactivity in a well-type automatic gamma scintillation counter (Searle model 1185R). Counts were obtained from the photon energy peaks of "mTc (140 keV), 201T1 (80 keV) and "'In (243 keV).…”

Section: Methodsmentioning

confidence: 99%

Contrast enhancement of myocardial infarction: dependence on necrosis and residual blood flow and the relationship to distribution of scintigraphic imaging agents.

Higgins¹,

Hagen²,

Newell³

et al. 1982

Circulation

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SUMMARY All or part of a myocardial infarction (MI) can be preferentially enhanced on computerized transmission tomography after i.v. administration of iodinated contrast material. To examine the relationship of this phenomenon to the presence of myocardial necrosis, the blood flow profile of the MIs and the distribution of radionuclide infarct imaging agents, collateralized infarcts were produced in six dogs (group A) and noncollateralized infarcts were produced in nine dogs (group B). After 48 hours of coronary occlusion, each dog received technetium-99m pyrophosphate ( mTc-PYP), thallium-201 (201T1), indium-111-labeled microspheres and meglumine sodium diatrizoate (Renografin-76) before sacrifice.Residual blood flow in the center of the MI was 3-27% in group A and less than 3% in group B. In group A, the iodine concentration in the center (1.33 mg/g myocardium), periphery (1.48 mg/g), and margin (1.09 mg/g) were several times higher than normal myocardium (0.45 mg/g). The distribution of "9mTc PYP was similar to that of iodine; the distribution of 201TI was roughly the inverse of that of iodine.In group B, the average iodine and OmTc concentrations in the margin, and periphery of the MI were several times higher than that in normal myocardium, but in the center neither concentration was significantly higher than normal. However, there was no consistent relationship between iodine and 201TI, as concentrations of iodine and 201TI were low in the center of the infarct and were inversely related at other sites.The results show that contrast material has a distribution in MI similar to that of "9mTc PYP and both are markers of ischemic myocardial necrosis. Distribution of both agents in the MI depends on a threshold level of residual myocardial blood flow.COMPUTERIZED transmission tomography (CTT) has been used to image myocardial infarctions in experimental animalsl-3 and, in a few instances, in man.' After i.v. or intracoronary administration of iodinated contrast material to dogs with myocardial infarctions, CTT scans have shown delayed and differential enhancement of the area of ischemic damage compared with normal myocardium. Measurement of myocardial tissue concentration of iodine have confirmed this preferential accumulation of contrast material in infarcted myocardium and have shown peak concentrations of iodine in the infarct at 10 minutes after i.v. administration of the contrast material.5Contrast material therefore can provide a positive image of the infarct on the CTT scan, similar to the image produced by technetium-99m pyrophosphate (99mTc-PYP) on scintigraphic scans of acute myocardial infarction.6 Moreover, like the BmTc-PYP scan, the pattern of contrast enhancement has been homogeneous in some infarcts and only partial or peripheral in others" 2 ( fig. 1) cumulation of iodinated contrast material in areas of ischemic myocardial damage has not been determined.The purpose of the current study was to determine the significance of contrast enhancement of myocardial infarctions by studying the relatio...

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Section: Methodsmentioning

confidence: 99%

Contrast enhancement of myocardial infarction: dependence on necrosis and residual blood flow and the relationship to distribution of scintigraphic imaging agents.

Higgins¹,

Hagen²,

Newell³

et al. 1982

Circulation

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“…BSP, cBSP, and phenol red solutions were alkalinized with 0.1 N NaOH to pH 10 before analysis. Bilirubin concentrations were determined by the method of Malloy and Evelyn (30) and iopanoic acid concentrations were determined by fluorescent excitation analysis (31). Radioactivity was measured by liquid scintillation counting (Beckman model LS-250, Beckman Instruments, Inc., Fullerton, Calif.) with external or internal standardization for quench correction.…”

Section: Methodsmentioning

confidence: 99%

The Micellar Sink

Scharschmidt¹,

Schmid²

1978

J. Clin. Invest.

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Although the importance of mixed micelles in the solubilization and biliary excretion of lipids is established, little is known about a possible role of mixed micelles in the excretion of other biliary solutes. Ultrafiltration and ultracentrifugation techniques were used to investigate the interaction between substances that are excreted in bile and biliary mixed micelles. Substances (urea, erythritol, sucrose) excreted in bile at concentrations equal to, or less than, that in plasma did not show an association with mixed micelles, whereas substances (indocyanine green, iopanoic acid, rose bengal, unconjugated and conjugated sulfobromophthalein, and conjugated bilirubin) excreted in bile at high concentration relative to plasma did. The percentage of these latter substances in bile associated with micelles varied from 26 to 93% and was relatively independent of concentration. In addition to their association with mixed micelles, these test solutes formed self-aggregates that were stabilized primarily by ionic bonds, and only a small percentage (range = 0-5%) of these solutes were present in bile in the form of monomer or complexes small enough to pass a 5,000-mol wt membrane.These findings offer a possible explanation for the increase in sulfobromophthalein, bilirubin, and indocyanine green maximal biliary excretory rate produced by bile salt infusion, and suggest that the concentrative transport into bile of endogenous compounds and xenobiotics may result from their incorporation into mixed micelles and other macromolecular complexes.

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“…Furthermore, the iodine content of a sample can be accurately measured by X-ray fluorescence without the need to take any precautions regarding biological treatment of the sample (9), which is a practical advantage of using nonionic contrast medium as the test substance for GFR measurement.…”

Section: Discussionmentioning

confidence: 99%

“…Iodine concentration measurement: The iodine concentration of the injected contrast medium and plasma samples was measured twice using a fluorescent excitation analysis system (X‐ray fluorescence analyser, RFA) with a 241‐americium source (EG & Ortec, Germany), using the method described by K aufmann and coworkers (9). The measuring range of the RFA was 0.01–2.0 mg/dl.…”

mentioning

confidence: 99%