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Biomedical subjects

S M Spies

Publications and source records attributed to S M Spies.

50 records · Page 3Linked to original sources

Sequential changes in factor VIII and platelets preceding deep vein thrombosis in patients with spinal cord injury.

The relationships between factor VIII associated activities, platelet function, and venous thrombosis were studied in 18 patients with lower limb paralysis following acute spinal cord injury (SCI). Deep vein thrombosis (DVT) was detected in 13 patients (72%). Eight of the 13 thromboses were documented between 6 and 8 d following injury while the other five episodes were noted on days 11 (two), 13, 18 and 22. The detection of thrombosis was preceded by marked increases in VIIIR:Ag and VIII:RCoF whereas VIII:C was only marginally increased. The platelet aggregation response to collagen was hyperactive by the sixth day while the platelet aggregate ratio (PAR) did not become abnormal until after DVT was detected. These studies suggest a chronology in the series of events leading to DVT in patients with lower limb paralysis following SCI. Initial elevations in VIII:Ag and VIII:RCoF are followed in sequence by increased platelet responsiveness to collagen, the occurrence of DVT, and the appearance of circulating platelet aggregates. Conceivably, VIIIR:Ag elaborated by endothelial cells alters platelet reactivity and provides an important determinant for venous thrombosis.

Adolescent↗

Diagnosis of hydronephrosis: comparison of radionuclide scanning and sonography.

Diagnostic sonographic and radioisotope scanning techniques have been shown to be useful in the diagnosis of obstructive uropathy. The accuracy of both methods was compared and sonography was found to provide the more accurate data (sensitivity, 90%; specificity, 98%; accuracy, 97%). Sonography provides excellent anatomic information and enables one to grade the degree of dilatation. Renal radionuclide studies were less sensitive in detecting obstruction, particularly in the presence of chronic renal disease, but offered additional information regarding relative renal blood flow, total effective renal plasma flow, and interval change in renal parenchymal function.

Adult↗

Early and long-term improvement in left ventricular performance following coronary bypass surgery.

Changes in left ventricular performance after coronary artery bypass grafting (CABG) have been variable. Earlier studies based on contrast left ventriculography have shown occasional improvement in left ventricular function in patients with unstable angina or abnormal preoperative ventricular performance, but for the most part repeat cardiac catheterization several months after operation has shown no significant changes in global left ventricular contraction. In the past few years, advances in radiopharmaceutical technology have made the characterization of left ventricular wall motion accurate and highly reproducible. Since prognosis in patients with coronary artery disease and survival after CABG have been related to global ejection fraction (EF), we employed prospectively on analysis of short-term and long-term changes in EF after CABG utilizing multidose hypothermic potassium crystalloid cardioplegia as the method of myocardial protection. Concomitantly, newer techniques in anesthesia and perioperative patient management were employed to minimize myocardial damage in these patients. Postoperative scintigraphic evaluation showed a transient (2-hour) depression in left ventricular function, followed by recovery to preoperative levels at 24 hours and significant improvement in EF at 7 days. From 7 days to 8 months postoperatively, there was no further change in resting EF, but there was another significant exercise-induced increase in EF at the long-term examination. Thus, present advances in the multidisciplinary management of patients with coronary artery disease are associated with improvement in resting and exercise-related EF postoperatively.

Aged↗

Technetium-99m stannous pyrophosphate myocardial scintigraphy after cardiopulmonary resuscitation with cardioversion.

Thirty consecutive patients underwent technetium-99m stannous pyrophosphate myocardial scintigraphy 48--72 hours after successful cardiopulmonary resuscitation and direct current cardioversion. Five patients with transmural myocardial infarctions by ECG and enzyme determinations were correctly identified by scintigraphy. Myocardial scans were positive in five of nine patients with nontransmural infarction. Of 16 patients without evidence of myocardial infarction, only two (13%) had false-positive myocardial scans. The overall accuracy of imaging in this series was 80%. We conclude that false-positive scans after cardiopulmonary resuscitation with electrical cardioversion are infrequent, and do not significantly detract from the value of myocardial scintigraphy in the diagnosis of myocardial infarction.

Aged↗

Unusual bone scan presentation in osteomalacia: symmetrical uptake--a suggestive sign.

Osteomalacia presents radiographically as deossification, coarsening of the trabecular pattern, and pseudofractures. Contrary to the usual bone scan manifestation of osteomalacia, consisting of a generalized increase in periarticular radionuclide accumulation and pronounced costochondral junctional uptake, this report describes an unusual bone scan presentation with negative radiographic studies showing only some deossification. Symmetric distribution of the focal lesions is considered a suggestive sign of osteomalacia.

Aged↗

A quantitative clinical comparison of three 99mTechnetium labeled brain imaging radiopharmaceuticals.

In a comparison study of three commonly employed 99mTc brain imaging pharmaceuticals, 16 patients with proven brain lesions had imaging performed with DTPA, glucoheptonate, and pertechnetate over a short interval of time. Lesion detectability was assessed by a data processing system which evaluated average lesion-to-background activity ratios for each patient examination. Statistical analysis of the resultant data demonstrated a significant improvement (20%) in lesion-to-background ratio in favor of one hour delayed DTPA images versus two hour delayed pertechnetate images. Comparison of one hour delayed DTPA images with one hour delayed glucoheptonate images did not reveal a significant difference in lesion-to-background ratio. The authors conclude that both Tc-DTPA and Tc-glucoheptonate are superior alternatives to pertechnetate when employed in the manner described.

Brain↗

Improved dynamic and static imaging of abdominal aortic aneurysms.

The authors describe a technique for rapid, convenient in vivo labeling of circulating erythrocytes with 99mTc and the application of this technique to the evaluation of abdominal aortic aneurysms. Dynamic perfusion images and equilibrium blood pool images were obtained in 9 patients with documented aneurysm, and 7 of them indicated an aneurysm on the radionuclide study.

Aorta, Abdominal↗

A case of myocardial abscess evaluated by radionuclide techniques: case report.

A patient with infective endocarditis was evaluated by Ga-67 citrate imaging, Tc-99m pyrophosphate imaging, equilibrium gated blood pool imaging, and Tl-201 imaging of the chest. The diagnosis of ventricular abscess was first suggested by an abnormal gallium scan. At surgery, an abscess was identified in the area where the scan was abnormal, and postoperatively a repeat scan was normal.

Abscess↗

Radioisotope scanning in inflammatory muscle disease.

Fourteen whole-body rectilinear bone scans using technetium 99m-polyphosphate were done in nine patients with well-documented inflammatory myopathy (either polymyositis or dermatomyositis). In all nine patients, the scans showed evidence of increased muscle labeling. Muscle uptake was markedly increased in one patient, moderately increased in two patients, and minimally increased in six patients. The degree of muscle labeling correlated with the severity of the muscle weakness at the time the scan was done. In four patients, who received high-dose corticosteroid treatment, muscle uptake was decreased following therapy. These findings suggest that radioisotope scanning may be useful in the diagnosis and management of patients with inflammatory muscle diseases.

Adrenal Cortex Hormones↗

Increased 99mTc-polyphosphate muscle uptake in a patient with polymyositis: case report.

A patient with well-documented rheumatoid arthritis and polymyositis displayed abnormal muscle uptake of 99mTc-polyphosphate during routine bone scanning for occult malignancy. The regions of increased uptake corresponded to the areas of clinically active inflammatory muscle disease. On serial scans the degree of muscle labeling correlated well with both clinical and laboratory indices of disease activity.

Adult↗

Biodistribution and dosimetry results from a phase III prospectively randomized controlled trial of Zevalin radioimmunotherapy for low-grade, follicular, or transformed B-cell non-Hodgkin's lymphoma.

UNLABELLED: Radiation dosimetry studies were performed in patients with non-Hodgkin's lymphoma (NHL) treated with 90Y Zevalin (90yttrium ibritumomab tiuxetan, IDEC-Y2B8) on a Phase III open-label prospectively randomized multicenter trial. The trial was designed to evaluate the efficacy and safety of 90Y Zevalin radioimmunotherapy compared to rituximab (Rituxan, MabThera) immunotherapy for patients with relapsed or refractory low-grade, follicular, or transformed NHL. An important secondary objective was to determine if radiation dosimetry prior to 90Y Zevalin administration is required for safe treatment in this patient population. METHODS: Patients randomized into the Zevalin arm were given a tracer dose of 5 mCi (185 MBq) (111)In Zevalin (111indium ibritumomab tiuxetan) on Day 0, evaluated with dosimetry, and then administered a therapeutic dose of 0.4 mCi/kg (15 MBq/kg) 90Y Zevalin on Day 7. Both Zevalin doses were preceded by an infusion of 250 mg/m(2) rituximab to clear peripheral B-cells and improve Zevalin biodistribution. Following administration of (111)In Zevalin, serial anterior and posterior whole-body scans were acquired and blood samples were obtained. Residence times for 90Y were estimated for major organs, and the MIRDOSE3 computer software program was used to calculate organ-specific and total body radiation absorbed dose. Patients randomized into the rituximab arm received a standard course of rituximab immunotherapy (375 mg/m(2) weekly x 4). RESULTS: In a prospectively defined 90 patient interim analysis, the overall response rate was 80% for Zevalin vs. 44% for rituximab. For all patients with Zevalin dosimetry data (N=72), radiation absorbed doses were estimated to be below the protocol-defined upper limits of 300 cGy to red marrow and 2000 cGy to normal organs. The median estimated radiation absorbed doses were 71 cGy to red marrow (range: 18-221 cGy), 216 cGy to lungs (94-457 cGy), 532 cGy to liver (range: 234-1856 cGy), 848 cGy to spleen (range: 76-1902 cGy), 15 cGy to kidneys (0.27-76 cGy) and 1484 cGy to tumor (range: 61-24274 cGy). Toxicity was primarily hematologic, transient, and reversible. The severity of hematologic nadir did not correlate with estimates of effective half-life (half-life) or residence time of 90Y in blood, or radiation absorbed dose to the red marrow or total body. CONCLUSION: 90Y Zevalin administered to NHL patients at non-myeloablative maximum tolerated doses delivers acceptable radiation absorbed doses to uninvolved organs. Lack of correlation between dosimetric or pharmacokinetic parameters and the severity of hematologic nadir suggest that hematologic toxicity is more dependent on bone marrow reserve in this heavily pre-treated population. Based on these findings, it is safe to administer 90Y Zevalin in this defined patient population without pre-treatment (111)In-based radiation dosimetry.

Antibodies, Monoclonal↗

Nuclear scanning with technetium-99m-sestamibi to evaluate ischemia in muscle flaps for cardiomyoplasty.

Mobilization of the latissimus dorsi muscle from the chest wall for cardiomyoplasty interrupts part of its blood supply. The time required for adequate collaterals to develop from the thoracodorsal artery is unknown. In four dogs, the latissimus dorsi muscle was mobilized as for cardiomyoplasty and stimulating electrodes were implanted. The muscle was replaced on the chest wall over a sheet of Gore-Tex (W. L. Gore & Associates, Inc. Flagstaff, AZ) membrane to block growth of collateral vessels from the chest wall. The opposite latissimus dorsi muscle served as the control. After a delay of 2 weeks the latissimus dorsi was burst stimulated at a rate of 80 per min with two 100 msec bursts at 85 Hz and 25 Hz for 30 min. Technetium-99m-sestamibi scans were then done to detect ischemia. Serial studies were done during the next several weeks. Images at 4 weeks demonstrated maximum uptake in the mobilized muscle, which did not subsequently improve. The authors conclude that the mobilized latissimus dorsi muscle can be imaged with technetium-99m-sestamibi and evidence of ischemia resolves at 4 weeks. These findings suggest that collateral flow is adequate as early as 4 weeks after mobilization of the latissimus dorsi muscle for cardiomyoplasty.

Animals↗