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Biomedical subjects

S M Spies

Publications and source records attributed to S M Spies.

At least 37 records · Page 2Linked to original sources
PubMed1987

Considerations for tomographic imaging of monoclonal antibodies.

Monoclonal antibodies have begun to assume a significant role in clinical research. The ability to label these agents has initiated research in the areas of radioimmunodetection and radioimmunotherapy. In the case of antibodies directed against tumor antigens, imaging has been employed to help assess location and extent of disease, and to provide information and extent of disease, and to provide information concerning biodistribution to be used in subsequent dosimetric calculations. Because of the low counting statistics characteristic of such images, the use of single photon emission computed tomography (SPECT) is suggested as a potential method of improving the diagnostic yield from image data. Careful attention to acquisition parameters and image processing options is needed if these goals are to be achieved.

Antibodies, Monoclonal↗
PubMed1986

Ventilation-perfusion scintigraphy in suspected pulmonary embolism: correlation with pulmonary angiography and refinement of criteria for interpretation.

Retrospective analysis of 139 ventilation-perfusion (V/Q) lung scans obtained for suspected pulmonary embolism (PE) was undertaken, using the Biello criteria for interpretation. All scans were correlated with chest radiographs obtained within 24 hours and with pulmonary angiograms obtained within 72 hours of the V/Q study. The prevalence of PE in the high-, intermediate-, and low-probability groups was 89.5%, 49.3%, and 3.6%, respectively. Using minor modifications of these criteria, V/Q scans interpreted as high or low probability had a sensitivity of 97.1%, specificity of 94.3%, and accuracy of 95.7%. Perfusion defects corresponding to radiographic abnormalities that were present for at least 10 days were less likely to be associated with PE. Separate analysis of 27 perfusion-only lung scans that met all other criteria for inclusion in the study confirmed the nonspecificity of perfusion-only lung imaging and indicated the need for ventilation imaging with Tc-99m-DTPA aerosol or Kr-81m gas for portable studies.

Adolescent↗
PubMed1985

Radioimmunoimaging of human small cell lung carcinoma with I-131 tumor specific monoclonal antibody.

In this study, an IgM monoclonal antibody (MAb600D11) directed against human small cell lung cancer (NCI-H69) was radiolabeled with iodine-131, and the biodistribution and image quality of the radiolabeled antibody was evaluated. Radiolabeling was achieved in a solid-phase system consisting of 1,3,4,6-tetrachloro-3a,6a-diphenylglycoluril. Labeling efficiencies and protein purification were accomplished using gel exclusion chromatography while radioimmunoreactivity was determined using a solid-phase radioimmunoassay procedure. The biodistribution of I-131-labeled MAbs was determined in Sprague-Dawley rats up to 7 days after injection. Highest organ concentrations were observed in liver (3.91 +/- 0.47 (SD) and 0.17 +/- 0.04 (SD) mean percent injected dose at 1-7 days after injections) and in thyroid (5.33 +/- 0.71 (SD) and 5.32 +/- 2.01 (SD) mean percent injected dose at 1-7 days after injection). Nude mice, bearing either a small cell lung tumor (NCI-H69) or a nonspecific tumor (adenocarcinoma), were injected with 400-800 microCi of I-131 labeled monoclonal antibody. Optimum tumor visualization was observed 2-4 days after injection with tumor concentrations as high as 10.4% of the initial injected dose. The results demonstrated that radioimmunoimaging of human small cell lung carcinoma was feasible with the tumor-specific IgM I-131-labeled MAb.

Adenocarcinoma↗
PubMed1983

Leucocyte labeling with colloidal 111In in whole blood.

A simple method of 111In leucocyte labeling in whole blood is described. 111In-colloid is initially formulated using iron (50 micrograms Fe+3). 111In-colloid is then added to 10mL of whole blood and leucocyte labeling is achieved by phagocytosis. Non-phagocytosed 111In-colloid is solubilized using a sodium citrate solution. Labeling efficiencies of 60-80% have been achieved with this method. If needed, excess 111In-soluble-complexes can be removed in the plasma fraction by appropriate centrifugation. The labeling method described is easy to use and has the advantage of selectively labeling leucocytes in a whole blood mixture.

Colloids↗
PubMed1983

Changes in left ventricular performance related to perioperative myocardial infarction in coronary artery bypass graft surgery.

Strict electrocardiographic, enzymatic, scintigraphic, and hemodynamic criteria for perioperative myocardial infarction (MI) were defined and related to serial assessments of left ventricular performance during rest and exercise in patients seen early and late after coronary artery bypass graft operation. Global left ventricular performance was determined by radionuclide ventriculography from which changes in the pattern of serial postoperative ejection fractions (EF) were obtained. Patients were divided into two groups based on the presence or absence of perioperative MI, and were matched in pairs on the basis of preoperative EF and extent as well as location of coronary artery obstructions. The results indicate that neither short- nor long-term depression in resting EF occurred subsequent to perioperative MI. However, an exercise-related increase in EF eight months postoperatively was depressed in patients who had perioperative MI compared with those who did not. Patients with new Q waves and abnormal postoperative elevation in serum levels of the myocardial isoenzyme of creatine kinase (CK-MB) had a greater early decrease in EF compared with patients without evidence of perioperative MI. However, seven days after operation, the EF in both groups returned to preoperative levels. Patients with abnormal technetium 99m-pyrophosphate scintigrams had changes in perioperative EF similar to those in patients without MI. The presence of low cardiac output syndrome immediately after operation was associated with immediate and short-term decreases in EF, which were not seen in any of the other patient subgroups.

Cardiac Output, Low↗
PubMed1983

The efficacy of medical stabilization prior to myocardial revascularization in early refractory postinfarction angina.

The timing of coronary artery bypass graft (CABG) surgery in patients with persistent, severe myocardial ischemia after an acute myocardial infarction is controversial. Based on the previous disappointing clinical experience with urgent surgery, a period of medical stabilization (mean ten days, range two to 28) prior to surgery was employed in a prospective nonrandomized clinical trial. The frequent use of intravenous nitroglycerin and intra-aortic balloon pumping was important in allowing preoperative clinical stabilization in these patients who were refractory to conventional medical therapy. The combined medical-surgical treatment protocol was associated with no early or late mortality in 20 patients who suffered preoperative myocardial infarction and demonstrated refractory post-infarction angina. Although these patients were considered to be high-risk surgical candidates, the incidence of perioperative myocardial damage in this selected group was comparable with that observed in patients undergoing elective CABG surgery at this institution without recent preoperative myocardial infarction. In order to determine the hemodynamic effectiveness of this selected patient management process, perioperative changes in left ventricular performance were determined by multigated cardiac blood pool imaging. Computer-based analysis of this radionuclide-related data allowed the accurate determination of ejection fraction (EF). Those patients with preoperative subendocardial infarction (N = 12) had no decrease in global EF 24 hours after operation and significant increases in EF seven days and eight months after operation. This pattern is analogous to that observed in patients without preoperative myocardial necrosis undergoing elective CABG surgery at this institution. Those patients with recent preoperative transmural myocardial infarction (N = 8) showed a decrease in EF 24 hours after operation, but recovered to preoperative levels seven days and eight months after operation. There was, however, no increase in EF in this subgroup of patients. On the basis of this study, the authors tentatively recommend a concerted effort at preoperative medical stabilization prior to CABG surgery in patients with persistent refractory myocardial ischemia soon after acute myocardial necrosis. A prospective, randomized study comparing urgent and delayed surgery, as well as nonsurgical treatment, will be necessary to define more precisely optimal management of this subgroup of cardiac patients.

Angina Pectoris↗
PubMed1982

Rapid miniaturized chromatography for Tc-99m IDA agents: comparison with gel chromatography.

Miniaturized chromatography systems for determining free pertechnetate and hydrolyzed reduced 99mTc levels in commercial 99mTc-labeled iminodiacetate (IDA) hepatobiliary radiopharmaceuticals were evaluated and the results compared with gel chromatography column scanning (GCS). Commercial IDA agents were evaluated including 2,6-dimethyl IDA, p-isopropyl IDA, p-butyl IDA, and 2,6-diisopropyl IDA. Of all the chromatography systems evaluated, only Gelman ITLC-SA with 20% NaCl and Gelman ITLC-SG with distilled water correlated with GCS in evaluating free pertechnetate and hydrolyzed reduced 99mTc levels for all IDA radiopharmaceuticals. The miniaturized chromatography procedure, as outlined, is rapid, taking less than 4 min, and can easily be incorporated into the daily quality control program in any nuclear medicine facility.

Chromatography↗
PubMed1982

Clinical evaluation of the relative effectiveness of multidose crystalloid and cold blood potassium cardioplegia in coronary artery bypass graft surgery: a nonrandomized matched-pair analysis.

Controversy exists concerning the most effective method of myocardial protection during coronary artery bypass graft operations. Accordingly, we performed a matched-pair analysis between 25 patients receiving multidose hypothermic potassium crystalloid cardioplegia and 25 other patients receiving cold blood potassium cardioplegia. Patients were matched on the basis of preoperative ejection fraction (EF) and the number of anatomically similar stenotic coronary arteries. The adequacy of myocardial protection was assessed by serial perioperative determinations of radionuclide ventriculography, hemodynamic measurements, analyses of electrocardiograms and serum levels of MB-CK. We found that the level of myocardial protection was similar between unstratified groups. However, when subgroups were selected on the basis of prolonged aortic cross-clamp time (greater than ninety minutes) or impaired preoperative left ventricular function (EF less than 40%), there was a suggestion that cold blood cardioplegia may be advantageous.

Adult↗
PubMed1982

Deep vein thrombosis in spinal cord injury: effect of prophylaxis with calf compression, aspirin, and dipyridamole.

Twenty-eight consecutive patients with acute spinal cord injury were randomised to one of two regimens for the prevention of deep vein thrombosis (DVT): external pneumatic calf compression (EPCC, 15), or EPCC combined with aspirin, 300 mg bid, and dipyridamole, 75 mg tid (ASA/dip, 13). DVT, detected by the 125I-fibrinogen test and impedence plethysmography, was confirmed by contrast venography. The incidence of DVT in the total group was 33 per cent, significantly less than the 78 per cent observed in 37 untreated patients studied previously (p less than 0.001). DVT developed in six of 15 patients receiving only EPCC, and three of 12 on ASA/dip as well as EPCC (p less than 0.1). The untreated patients studied earlier had significantly increased circulating platelet aggregates, increased platelet affinity for collagen, and elevated factor VIII activities, which generally coincided with the development of DVT (usually 7-9 days after injury). Prophylaxis partially prevented these coagulation abnormalities and delayed the onset of thrombosis. While the differences in the haemostatic parameters between those not treated with ASA/dip and those receiving these agents were not statistically significant (except for the platelet-collagen affinity), there was a trend toward less elevated values in the drug-treated patients. We conclude that spinal cord injury patients are at extreme risk for DVT, and have abnormal platelet and factor VIII activities. Prophylaxis with EPCC significantly and safely reduces the risk of DVT in these patients.

Aspirin↗
PubMed1981

Hemophilic bleeding evaluated by blood pool scanning.

The technique of blood pool scanning was used to examine 15 hemophilic subjects. Employing an in vivo method for erythrocyte labeling with Technetium-99 m, a dynamic perfusion sequence is obtained using a scintillation camera positioned over the area to be examined. This demonstrates the vascularity of the tissue. Subsequently, equilibrium blood pool images of the area are obtained and analyzed with a densitometer to assess relative regional blood volume. In patients who were not bleeding but had chronic arthropathy, vascularity was not increased, and the blood volume of comparable joints was similar. By contrast, marked increases in vascularity and image density were observed in studies of acutely bleeding joints. Chronic hemarthroses were associated with persistent, but less marked increases in joint perfusion. Transient increases in joint vascularity were demonstrated after insertion of knee prostheses. In a patient with a thigh hematoma, the dimensions of the hemorrhage were clearly delineated. Since only a tracer dose of nuclide is infused intravenously, there are no allergic reactions or other side effects of the procedure. Blood pool scanning is a safe, non-invasive technique that augments clinical and radiographic evaluations, and provides a new dimension in the assessment of the hemophilic patient.

Acute Disease↗
PubMed1981

Nonrandomized matched pair analysis of intermittent ischemic arrest versus potassium crystalloid cardioplegia during myocardial revascularization.

The quest for the ideal method of myocardial preservation during coronary artery bypass graft (CABG) surgery continues at a rapid pace. Nevertheless, in the present clinical practice of cardiac surgery, the choice is chiefly between hypothermic intermittent ischemic arrest and hypothermic potassium cardioplegia. This study applies newer technics in radionuclear cardiology, as well as more conventional enzymatic, electrocardiographic, and hemodynamic determinations, to the evaluation of the effectiveness of the previously mentioned modes of myocardial protection. Serial assessments are made preoperatively as well as during the first ten days postoperatively. We find that the perioperative incidence of myocardial damage and changes in left ventricular performance are almost identical using either method in patients with relatively normal preoperative left ventricular performance who do not have severe preoperative refractory ischemia or necrosis.

Aged↗
PubMed1981

The paper spot test: a rapid method for quantitating stannous concentrations in radiopharmaceutical kits.

We have developed a simplified, semiquantitative test for the determination of stannous tin in pyrophosphate and other tin-containing radiopharmaceuticals, excluding those stabilized with ascorbic acid and MAA preparations. The test involves the formation and disappearance of a positive red color complex in the presence of Sn(II) and in acidified porphyrin solution. With this technique, the time of spot disappearance is directly proportional to the Sn(II) concentration spotted. The procedure is easy to use, requiring only a high-intensity light source (30-watt light bulb) and a timing device. The test is accurate, reproducible, and sensitive to Sn(II) levels as low as 40 micrograms/ml. Because the procedure is rapid (requiring less than 5 min), it can easily be incorporated into the routine radiopharmaceutical quality-control program of any nuclear medicine facility.

Diphosphates↗
PubMed1981

Serial assessment of left ventricular performance following coronary artery bypass grafting. Early postoperative results with myocardial protection afforded by multidose hypothermic potassium crystalloid cardioplegia.

Forty patients who recently underwent coronary artery bypass graft (CABG) operations had serial hemodynamic and scintigraphic studies. Multidose hypothermic potassium crystalloid cardioplegia was used for myocardial protection and newer techniques in anesthetic management and perioperative patient care were also employed. The method of equilibrium cardiac gated blood pool (GBP) scintigraphy was used to obtain perioperative changes in global ejection fraction (EF) and regional wall motion (RWM). Ninety percent of patients displayed a decrease in EF 2 hours postoperatively when compared to their preoperative values. This change was also associated with a fall in cardiac index (CI) and left ventricular stroke work index (LVSWI). Twenty-four hours postoperatively, EF and CI recovered to preoperative levels, but LVSWI remained depressed. Seven days postoperatively, global EF had improved to a value greater than the preoperative one (50% +/- 3% versus 57% +/- 4%, p < 0.05). Perioperative changes in RWM followed the same pattern as EF, but recovery in this index of regional contractility was faster than EF, since maximal improvement was observed 24 hours postoperatively. Thus transient left ventricular dysfunction is common immediately after CABG, but recent advances in myocardial protection and perioperative management are associated with short-term increases in regional and global left ventricular function documented by noninvasive GBP imaging.

Aged↗
PubMed1980

Bone scan in a case of amyloidosis.

A 49-year-old woman was diagnosed as having multiple myeloma and tuberculosis of the spine (Pott's disease) in 1973. In 1975, she complained of skin nodules in her lower extremities. Biopsy showed that these were amyloid nodules. A bone scan in 1978 showed accumulation of Tc-99m-MDP in the nodules. To our knowledge, this finding has not been previously described.

Amyloidosis↗