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Biomedical subjects

H A Goldstein

Publications and source records attributed to H A Goldstein.

At least 19 recordsLinked to original sources
PubMed1990

Safety assessment of gadopentetate dimeglumine in U.S. clinical trials.

Gadopentetate dimeglumine is an intravenous contrast medium used in magnetic resonance imaging. To determine its safety, the authors summarized data concerning adverse reactions, laboratory parameters, and other assessments for 1,068 adult patients who received gadopentetate dimeglumine in United States clinical trials. For all studies, 213 of 1,068 patients (19.9%) who received gadopentetate dimeglumine experienced one or more clinical adverse reactions. Most of these reactions were minor and short-lived. Hematologic, blood chemistry, and urinary evaluations showed no apparent drug-related effects, with the exception of a transient, asymptomatic rise in serum iron and bilirubin levels in some patients. Other safety assessments--electrocardiography, electroencephalography, neurologic examinations, and vital signs--showed no clinically significant trends in change from baseline results. It was concluded that gadopentetate dimeglumine demonstrated a high degree of safety and tolerance.

Bilirubin↗
PubMed1990

Hemodynamic effects of Gd-DTPA administered via rapid bolus or slow infusion: a study in dogs.

The hemodynamic effects of rapid (10 sec) versus slow (1 min) IV injection of Gd-DTPA were compared in normal, pentobarbital-anesthetized mongrel dogs. Hypertonic mannitol and isotonic saline were used as equiosmotic and equivolumetric controls. Two dose levels of Gd-DTPA were administered: 0.1 mmol/kg and 0.5 mmol/kg, corresponding to dose volumes of 0.2 and 1.0 ml/kg, respectively. The rapid injection of a high dose (0.5 mmol/kg) produced a transient decrease in arterial blood pressure (21 mm Hg, p less than .001), which returned to control values within 1 min after the injection. Slow IV infusion at this high dose had no statistically significant hemodynamic effects. There were no statistically significant effects of the lower dose (0.1 mmol/kg) administered as a bolus or by infusion, nor of the saline or osmotic control solutions. These results suggest that acute hemodynamic effects of Gd-DTPA are not observed at clinically relevant doses and the vasodilation observed at a higher dose may result from a direct action of the contrast agent.

Analysis of Variance↗
PubMed1989

Multicenter double-blind placebo-controlled study of gadopentetate dimeglumine as an MR contrast agent: evaluation in patients with cerebral lesions.

A multicenter double-blind randomized study was designed to evaluate and compare the safety and diagnostic efficacy of gadopentetate dimeglumine (Gd-DTPA) (0.1 mmol/kg) against a saline placebo for use as an IV contrast agent for MR. The randomization code provided for a 2:1 ratio of Gd-DTPA and saline patients. Six investigators studied 88 patients with signs and symptoms of a cerebral lesion. Although safety data were complete in all 88 cases, only 83 had valid efficacy data (57 received Gd-DTPA, 26 placebo). Three patients were excluded from efficacy evaluation because of incomplete scans or scans with severe motion artifacts. Two patients were excluded for protocol variations (did not have a mass lesion). The protocol required that spin-echo MR images be acquired both before and after infusion at mode 1, 500/30/2 (TR/TE/excitations), and at a single-echo mode 2 sequence within a selected range, 1500-2000/56-90/2. Additional TEs could also be used at the discretion of each investigator. Efficacy was determined by comparing post- with preinjection images for relative degree of enhancement and improvement of diagnostic ability after injection, and by comparing these results with placebo results. Enhancement was reported in 43 (75%) of 57 Gd-DTPA patients and in none of the 26 placebo patients. Improvement of diagnostic ability was noted in 37 of 57 Gd-DTPA patients and in no placebo patients. Of 17 patients receiving Gd-DTPA for whom no diagnosis could be made before infusion, nine of 17 were diagnosed after infusion. By comparison, none of five patients not diagnosed before infusion of placebo could be diagnosed after infusion. Of 43 patients in whom lesion enhancement was observed after Gd-DTPA infusion, the diagnosis changed after infusion in 16 (37%) and the number of lesions detected after infusion increased in 10 (23%). Safety studies showed no clinically significant abnormal trends. Minor changes in blood pressure, pulse, and serum iron levels were noted in a higher percentage of Gd-DTPA patients. This study confirms that Gd-DTPA is an efficacious contrast agent for use with MR and that it exhibits excellent patient tolerance. Enhancement allows for a decisive diagnosis to be made in selected cases in which such capability had previously been lacking with unenhanced MR.

Adolescent↗
PubMed1989

Clinical trials with iotrolan in myelographic and computed tomography applications in the United States.

Iotrolan, a new nonionic contrast agent, was studied in the United States using 190 mg I/ml, 240 mg I/ml, and 300 mg I/ml concentrations. Procedures performed were lumbar, thoracic, cervical, and total columnar myelography and computed tomography applications. Two multicenter double-blind studies (iotrolan versus metrizamide in 190 mg I/ml and 240 mg I/ml concentrations) and five open-label studies were conducted in a total of 863 patients (569 iotrolan, 294 metrizamide). Iotrolan and metrizamide both demonstrated diagnostic efficacy. Iotrolan demonstrated better patient tolerance in comparison with metrizamide.

Adolescent↗
PubMed1988

Gd DTPA. Clinical efficacy.

Both the diagnostic accuracy and sensitivity of the MRI diagnosis of central nervous system neoplasms appear to be improved by the administration of a paramagnetic contrast agent, Gd DTPA.

Brain Neoplasms↗
PubMed1988

Renal scans in pregnant transplant patients.

This study demonstrates the normal technetium-99m diethylenetriaminepentaacetic acid ([99mTc]DTPA) renal scan in pregnant patients with transplanted kidneys. Five pregnant renal transplant patients had seven [99mTc]DTPA renal studies to assess allograft perfusion and function. All scans showed the uteroplacental complex. The bladder was always compressed and distorted. The transplanted kidney was frequently rotated to a more vertical position. In all patients allograft flow and function were maintained. There was calyceal retention on all studies and ureteral retention activity in three of five patients. Using the MIRD formalism, the total radiation absorbed dose to the fetus was calculated to be 271 mrad. This radiation exposure is well within NRCP limits for the fetus of radiation workers and an acceptable low risk in the management of these high risk obstetric patients.

Female↗
PubMed1987

The effect of prednisolone, thromboxane, and platelet-activating factor receptor antagonists on lymphocyte and platelet migration in experimental cardiac transplantation.

Three agents that significantly prolong cardiac allograft survival were tested in Lewis rats that were recipients of hearts from Lewis X Brown-Norway F1 hybrid donors. In the presence of azathioprine, the effects of daily administration of either the thromboxane antagonist (L 640,035), the platelet-activating factor (PAF) antagonist (BN 52021) or prednisolone were evaluated on the infiltration of cardiac allografts by syngeneic lymphocytes and platelets labeled with 111indium. As anticipated, platelet deposition was reduced by the thromboxane antagonist and unaffected by the PAF antagonist; the latter is likely due to the known absence of PAF receptors in rat platelets. In addition prednisolone had no effect. The increased accumulation of lymphocytes on days 4-5 was also unaffected by all three drugs. These experiments indicate that, in this model, graft survival is not necessarily related to lymphocyte and platelet infiltration of the graft. The data also provide evidence for the efficacy of the thromboxane receptor antagonist L 640,035 in preventing platelet deposition in vivo.

Animals↗
PubMed1987

Average radiation doses in a standard head examination for 250 CT systems.

Approximately 250 computed tomography (CT) systems were surveyed in a nationwide study to determine the average radiation dose resulting from a typical adult head procedure. The multiple scan average dose (MSAD) was selected as the dose descriptor. For the typical adult CT head procedure, the MSAD was generally within 2.2-6.8 rads (22-68 mGy). Variations in dose by a factor of two or more were often seen for a given manufacturer and model. These dose ranges indicate a potential to reduce dose by carefully selecting imaging techniques. Overall, variations in dose can result from differences in the user's choice of technique (desired image quality) or from actual differences in scanner performance (caused by differences in collimation, filtration, or geometry). To use CT appropriately, a facility should consider dose as well as image quality in selecting optimal techniques for typical modes of operation.

Head↗
PubMed1986

The assessment of contractile reserve after thrombolytic therapy for acute myocardial infarction.

"Stunned" myocardium prevents the assessment of myocardial salvage after streptokinase. In order to unmask "stunning," we sought to evaluate left ventricular inotropic contractile reserve of patients after streptokinase. Radionuclide ventriculograms were obtained in 75 consecutive patients 2 weeks after myocardial infarction, at rest and during intravenous isoproterenol infusion. Resting and isoproterenol-stressed ejection fractions were compared in the patent and closed-infarct vessel groups. Although there was no difference in the resting ejection fractions between the patent group (0.48 +/- 0.02) and the closed group (0.48 +/- 0.02), isoproterenol increased the ejection fractions in the patent group (increase 0.14 +/- 0.01) significantly more than in the closed group (increase 0.06 +/- 0.01) (p less than 0.0001). Thus, despite identical resting ventricular function, the greater inotropic contractile reserve in the patent infarct vessel group suggests that restoration of blood flow in acute myocardial infarction salvages myocardium.

Adult↗
PubMed1986

Role of radionuclides in acute cardiac care: current status.

The aforementioned studies demonstrate the varied and important clinical information concerning acute myocardial infarctions that is obtainable from certain radionuclide procedures. Limitations of these procedures as well as futuristic improvements are also discussed.

Computers↗
PubMed1985

Atlas of hepatic arterial perfusion scintigraphy.

Tc-99m MAA intra-arterial perfusion studies are necessary to determine blood flow distribution for hepatic arterial chemotherapy. In this mini-atlas, examples selected from over 900 cases to illustrate important points to aid in a better understanding and interpretation of these studies with particular emphasis on diagnostic and therapeutic interventions are presented.

Humans↗
PubMed1985

Thallium/technetium functional imaging of the thyroid and parathyroid. A case report.

This case report demonstrates the usefulness and limitations of technetium/thallium scintigraphy in the diagnosis of parathyroid hyperplasia. In addition, discordant thyroid tracer uptake (Tc-99m but not TI-201) due to colloid cysts is described. Another perspective in the controversy over which radiopharmaceutical, Tc-99m or TI-201, should be injected first also is presented.

Aged↗