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Biomedical subjects

J G Jacobstein

Publications and source records attributed to J G Jacobstein.

At least 19 recordsLinked to original sources
PubMed1995

Interictal single-photon emission computed tomography in partial epilepsy. Accuracy in localization and prediction of outcome.

The role of interictal brain single-photon emission computed tomography (SPECT) was examined using (99mTc)- labeled hexamethylpropyleneamine oxime (HMPAO) in refractory partial epilepsy. The accuracy with which SPECT localized an epileptic focus and whether it predicted long-term postoperative seizure relief were assessed. Twenty patients were evaluated, 14 of whom ultimately had anterior temporal lobectomy with follow-up ranging from 41 to 56 months. A single-headed gamma camera was used. The interictal SPECT showed ipsilateral temporal hypoperfusion in 8 (47%) of 17 patients with temporal lobe epilepsy and showed either multilobar hypoperfusion or no perfusion defects in the rest. The sensitivity and specificity were similar in patients with a more complex clinical picture who required intracranial electrodes and those who did not. Presence or absence of temporal lobe hypoperfusion did not correlate with postoperative seizure relief. It is concluded that interictal SPECT with 99mTc-HMPAO with a single-headed gamma camera does not add useful information in preoperative localization or predicting postoperative seizure relief.

Adolescent↗
PubMed1991

Epileptic palatal myoclonus.

Palatal myoclonus (PM) is usually caused by lesions of the brainstem. We report a case of PM of focal cortical origin in a patient with epilepsia partialis continua. The PM sometimes occurred in isolation, and at other times was accompanied by unilateral face, neck, and arm twitching. This was documented by both EEG and SPECT.

Adolescent↗
PubMed1981

Visualization of the liver with 99mTc-EHDP in thalassemia major.

A case is reported in which substantial liver uptake of 99mTc-hydroxyethylidene diphosphonate (99mTC-EHDP) was seen on bone scan. The patient, a 25-year-old male with the diagnosis of thalassemia major made at the age of 3 years, had received regular blood transfusions over many years. Clinical and laboratory evidence of hemosiderosis suggests that the presence of large quantities of iron in the liver of this patient may have been responsible for the hepatic uptake of the bone scanning agent.

Adult↗
PubMed1981

Anterior S-T segment depression in acute inferior myocardial infarction: indicator of posterolateral infarction.

Although patients with acute inferior myocardial infarction often manifest S-T segment depression in precordial electrocardiographic leads, the pathophysiologic abnormalities associated with this finding are poorly understood. To examine this problem, electrocardiographic findings on admission were compared with results of radionuclide cineangiography performed within 38 hours of the onset of symptoms in 25 patients with inferior infarction. Summation of S-T depression in leads V1 through V4 permitted the separation of patients into two groups: Group A (11 patients with 0.20 mV or less of S-T depression) and Group B (14 patients with 0.45 vM or more of S-T depression). The radionuclide cineangiogram revealed inferior wall dysfunction in all patients. Additional posterolateral dysfunction was seen in 13 patients, all in Group B. Patients in Group B had a relatively larger infarction (peak creatine kinase Units - 756 +2- 358 in Group A versus 1,566 +/- 983 units in Group B, p less than 0.01) and greater functional impairment (ejection fraction - 45 +/- 12 in Group A versus 33 +/- 12 in Group B, p less than 0.01). The relation between precordial S-T segment depression and posterolateral dysfunction appears to be largely independent of electrocardiographic evidence of "true posterior infarction." Thus moderate or severe anterior precordial S-T depression in patients with acute inferior infarction is a sensitive and specific indicator of relatively extensive myocardial damage, primarily involving the posterolateral region.

Adrenergic beta-Antagonists↗
PubMed1980

Visualization of a malignant pericardial effusion with Tc-99m-EHDP.

Increased accumulation of radioactivity in a pericardial effusion was observed on a routine bone scan in a patient with known primary breast and lung carcinomas. A dynamic flow study and echocardiography confirmed the presence of the effusion. Microscopic examination of the pericardial fluid revealed the presence of malignant cells.

Bone and Bones↗
PubMed1980

Decreased bone uptake of technetium-99m polyphosphate in thalassemia major.

Bone scans were performed with Tc-99m stannous polyphosphate on four patients with thalassemia major. Three of the scans show generalized decrease in skeletal uptake of the radiopharmaceutical, associated with renal enlargement and markedly increased renal radioactivity. The skeletal findings are consistent with the known bone abnormalities in thalassemia major, which are secondary to the extensive marrow hyperplasia and include loss of trabeculae and cortical thinning with consequent loss of bone mass. The increased renal uptake is probably due in part to the increased renal excretion (secondary to the poor bone uptake) and in part to the tubular dilatation and renal enlargement associated with thalassemia major. In addition, the presence of excessive amounts of iron in these patients may play a role in both the skeletal and renal findings.

Adult↗
PubMed1980

Ischemia and infarction in the isolated rabbit heart: a model for the evaluation of myocardial imaging agents.

An isolated-heart preparation has been adapted to permit rapid evaluation of, and imaging by, myocardial tracers. The rabbit heart provided a mass large enough for imaging and serial biopsies. Coronary arteries could be selectively ligated and provided landmarks for epicardial ST segment mapping. Uptake ratios between a tissue sample and normal myocardium (T/N), obtained using Tc-99m glucoheptonate as an infarct-seeker, increased with duration of the ischemic period, which was followed by reflow. After 25 min of occlusion the T/N was 4.5; after 40 min T/N = 6; after 60 min T/N = 8; and after 120 min T/N = 19. This well-controlled adjunct to in vivo studies allows evaluation of myocardial imaging agents without interfering with systemic effects or blood and tissue background. Functional and structural changes can be sequentially measured and correlated with the localization of various radiopharmaceuticals.

Animals↗
PubMed1979

Perioperative myocardial infarction associated with coronary artery bypass graft surgery: improved sensitivity in the diagnosis within 6 hours after operation with 99mTc-glucoheptonate myocardial imaging and myocardial-specific isoenzymes.

The present study was performed to evaluate scintigraphic imaging with technetium 99m-labeled glucoheptonate and serum enzyme levels of creatine phosphokinase isoenzyme (MB-CPK) in the early diagnosis of perioperative acute myocardial infarction associated with saphenous vein bypass graft operations. Myocardial imaging was done in 27 patients (50% of whom were considered high-risk) before operation and again 5 hours after operation. Four of these patients (15%) had both electrocardiographic and serum MB-CPK evidence of acute myocardial infarction, and all 4 had developed positive postoperative scintigrams. Four other patients had only elevated serum MB-CPK, and scintigrams became positive after operation in 3 of them. In addition, serum MB-CPK 6 hours after operation was 83 +/- 21 mIU/ml (mean +/- standard error of the mean) in patients with positive postoperative scans compared with 24 +/- 5 mIU/ml in those patients with negative postoperative scintigrams (p less than 0.001). Myocardial imaging with 99mTc-glucoheptonate in the perioperative period is rapid, safe, and atraumatic. Furthermore, our results suggest that it is a sensitive method for the early diagnosis of perioperative acute myocardial infarction, and, when imaging is combined with serum MB-CPK isoenzyme analysis, the reliability of the diagnosis of acute myocardial infarction is enhanced even further. Only 1 of the patients who showed perioperative myocardial damage had acute hemodynamic compromise or obvious impairment of recovery in the immediate postoperative period, and the 30-day mortality of the total group was 4% (1 of 27).

Acute Disease↗
PubMed1979

A simple method for the air monitoring of xenon-133.

A simple and inexpensive method to monitor the air for Xe-133 is described. The procedure requires only standard 10-cc evaculated tubes, a scintillation well counter, and a dose calibrator--standard equipment in most nuclear medicine laboratories. Air contamination in the range of the maximum permissible concentration in restricted areas (10pCi/cc) can be detected easily by this technique.

Air Pollution↗
PubMed1978

Role of delayed intraaortic balloon pumping in treatment of experimental myocardial infarction.

Intraaortic balloon pumping improves coronary blood flow characteristics while simultaneously reducing myocardial oxygen demands by reducing aortic systolic pressure. Clinical application of intraaortic balloon pumping has largely been in the "high risk" patient (cardiogenic shock, postinfarction angina, left main coronary artery disease and unstable angina) for support during diagnostic studies or cardiac surgery, or both. In addition, there is some evidence that balloon pumping immediately after coronary occlusion reduces the size of experimentally induced myocardial infarcts. In this study, myocardial infarcts were produced by ligation of the left anterior descending coronary artery in 12 dogs, 6 of which were treated with balloon counterpulsation beginning 3 hours after coronary occlusion. All dogs were killed 8 hours after coronary ligation. Intraaortic balloon pumping resulted in the expected hemodynamic changes (decreased aortic systolic pressure, left ventricular end-diastolic pressure and heart rate and increased aortic peak diastolic pressure). In addition, there was a significant reduction in infarct size in the group with balloon pumping as determined with epicardial S-T segment mapping, myocardial imaging with technetium-99m-glucoheptonate and histochemical staining with nitroblue tetrazolium. These results suggest that even when instituted as long as 3 hours after coronary occlusion, intraaortic balloon pumping results in significant reduction in infarct size and, it might be speculated, the mortality and morbidity associated with acute myocardial infarction may also be decreased.

Angina Pectoris↗
PubMed1978

Early quantification of experimental myocardial infarction with technetium-99m glucoheptonate: scintigraphic and anatomic studies.

Recent advances in understanding of the pathophysiology of myocardial necrosis indicate the need for a noninvasive method that will allow detection and quantification of infarcts in the first few hours after the onset of infarction. Myocardial infarct scintigraphy using technetium-99m glucoheptonate is capable of detecting infarction in dogs and man within 4 to 6 hours of onset. Studies were performed in 45 dogs with acute myocardial infarction: 28 with with an anterior infarct, 5 with an inferior infarct, 6 with an anterior infarct studied after infusion of mannitol and 6 with ligation of the left anterior descending coronary coronary artery and reperfusion of the ischemic area. The dogs were given 20 m Ci of technetium-99m glucoheptonate 1 hour after coronary occlusion, subjected to imaging 5 to 9 hours later and then killed. The experiments revealed that (1) scintigraphic infarct size correlated with infarct weight for anterior (r = 0.85) and inferior (r = 0.88) infarcts; (2) technetium-99m glucoheptonate also concentrated in a rim of myocardium around the infarct that probably represented the ischemic zone; and (3) technetium-99m glucoheptonate uptake by infarcted myocardium could be greatly increased with mannitol and reperfusion.

Animals↗
PubMed1977

Splenic uptake of 99mTc-diphosphonate in sickle cell disease associated with increased splenic density on computerized transaxial tomography.

Splenic uptake of 99mTc-diphosphonate was found on the bone scan of a patient with sickle cell disease. No splenic activity was demonstrated on 99mTc-sulfur colloid liver-spleen scans and no evidence of splenic calcification was seen on plain abdominal radiographs. A computerized transaxial tomographic scan, however, did demonstrate a small spleen denser than other abdominal organs. The splenic accumulation of 99mTc-diphosphonate and the increased density on computerized transaxial tomography could be attributed to microscopic splenic calcifications and/or iron deposits in the spleen.

Adolescent↗