Assessment of cardiac reserve in patients with hyperthyroidism.

Radionuclide multigated cardiac imaging was performed to assess functional cardiac reserve in patients with hyperthyroidism. In 11 normal individuals, submaximl supine exercise increased heart rate (HR) by 60 percent, systolic blood pressure (BP) by 54 percent, and the left ventricular ejection fraction (LVEF) by 13 percent. All of these increments were statistically significant (p < 0.

Spectroscopic analysis of the equilibrium and kinetic DNA binding properties of several actinomycin analogs.

Experiments are described that measure DNA dissociation kinetics and thermal denaturation temperatures for a series of actinomycin analogs containing, in the 3' amino acid position, pipecolic acid, proline or azetidine-2-carboxylic acid. Also included are studies on actinomycin C3. Analysis of the temperature dependence of the slowest rate constant for DNA dissociation shows that both the enthalpy and entropy of ativation increase as the ring size of the 3' amino acid decreases from six to five to four.

Comparison of gated radionuclide scans and chest radiographs. Assessment of left ventricular impairment in patients with coronary disease.

Diagnostic efficacy of gated cardiac blood pool imaging was studied in 41 consecutive patients with LV ejection fractions (LVEF) less than or equal to 0.50. Eighty percent of patients were receiving therapy for LV failure at the time of the study.

Angiotensin infusion effects on left ventricular function. Assessment in normal subjects and in patients with coronary disease.

Radionuclide multigating of the cardiac cycle was employed to assess effects of angiotensin infusion on left ventricular function. In six normal subjects, angiotensin infusion decreased heart rate (HR) from 72 +/- SEM 2 to 57 +/- 2 beats/min (P less than 0.001); while systolic blood pressure (BP) increased from 119 +/- 2 to 178 +/- 1 mm Hg (P less than 0.

Blood transfusion reactions.

Transfusion reactions range from mismatching of blood causing reaction, to the transmission of diseases such as hepatitis through the improper screening of blood. This paper discusses guidelines for transfusions of various blood fractions or components, reasons for transfusions of red blood cells rather than whole blood, the problem of blood platelets, the prohibition against fibrinogen, and the various volume expanders.

Viscoelastic behavior of mammalian DNA.

The viscoelastic behavior of rat 9L cellular DNA was studied as a function of the detergent used for lysis, the pH and duration of lysis, and gamma ray dose. For nondenaturing lysis conditions, a model of the DNA was proposed to account for the effects of these agents on the viscoelastic retardation time. It was concluded that these agents affect the hydrodynamic radius of the DNA rather than its molecular weight.

Abnormal images of right heart disorders.

Increasing attention is being given to radioisotopic studies of the right heart. Measurement of right ventricular ejection fraction has become more common. We present examples of cardiac images which were obtained during the scintigraphic assessment of right sided cardiac disorders.

Assessment of left ventricular function in aortic insufficiency using echocardiography, gated scintigraphy and contrast angiography.

Echocardiography, gated scintigraphy and contrast angiography were used to measure left ventricular ejection fractions in 20 patients with varying degrees of aortic insufficiency. There was good correlation between the radionuclide and the angiographic ejection fractions. Echocardiographic ejection fraction correlated less well with the angiographic ejection fraction.

Binding of N-methyl isatin beta-thiosemicarbazone-copper complexes to proteins and nucleic acids.

N-Methyl isatin beta-thiosemicarbazone-copper complexes interact with nucleic acids and proteins as shown by ultraviolet (UV) and visible spectroscopy and Sephadex exclusion chromatography. The Cu++ ions are most effective; Co++ ions have less albeit significant activity. Chelating agents, such as Tris and histidine, high NaCl concentration, and dimethyl sulfoxide reduce the binding of the drug-metal complex.

Radionuclide methods in the assessment of left ventricular function.

The recent introduction of newer scintillation cameras, convenient radiopharmaceuticals and innovative data-processing systems has hastened the use of radionuclide methods in the evaluation of cardiac function. This review familiarizes the primary internist with physics and instrumentation required in understanding cardiovascular nuclear images. Basic principles underlying the gated cardiac blood-pool scan and the first-pass study are described.

Radionuclide left ventricular dV/dt for the assessment of cardiac function in patients with coronary disease.

To investigate potential uses of left-ventricular (LV) systolic ejection rate (LV dV/dt) in the evaluation of LV function, we examined the effect of exercise, angiotensin, and leg raising on LV ejection fraction and LV dV/dt in patients with coronary-artery disease. The following observations were made: a) LV ejection fraction and dV/dt changed proportionately, but in opposite directions, during supine exercise; b) LV ejection fraction and dV/dt decreased to a similar extent during angiotensin infusions; and c) LV ejection fraction and dV/dt were unchanged by leg raising. The changes in peak and mean LV dV/dt were similar.

Fenestrated sagittal sinus mimicking posterior cerebral infarction.

Two patients who presented with abnormal neurological findings and focal abnormalities on static brain imaging, were felt to have infarction in the distribution of the posterior cerebral artery. However, the posterior flow study delineated the cause of the abnormality as being a fenestrated anomaly of the sagittal sinus. The incidence of occlusive disease of the posterior cerebral artery, its clinical and scintigraphic presentation and the potential pitfalls for misinterpretation are reviewed.

Implications of liver activity associated with 133Xe ventilation lung scans.

A series of 35 xenon-133 (133Xe) ventilation studies yielded nine cases demonstrating accumulation of activity in the liver. Maximum intrahepatic deposition of radioxenon occurred during the washout phase of the study. In addition to those clinical instances which make this phenomenon possible, i.

A review of carotid cavernous fistula including diagnosis and evaluation by nuclear medicine angiography.

The various causes and differential diagnosis of carotid cavernous fistula are discussed as well as the description of the use of radionuclide angiography in the diagnosis and evaluation of patients with carotid cavernous fistulas. Radionuclide angiography has proven extremely useful in the diagnosis and follow-up of patients with carotid cavernous fistulas. The procedure is of maximum benefit in situations where repeat studies are required at frequent intervals.

Comparison of two radioimmunoassays and a microbiologic assay for bleomycin.

Recently two radioimmunoassays have been independently developed for determination of bleomycin levels. In this study these assays are compared with each other and with a standard microbiologic assay for bleomycin. Bleomycin levels were determined in serum and urine samples obtained at varying intervals following intramuscular bleomycin injection.