Captopril renography in Goldblatt hypertension.
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Animals↗
Biomedical subjects
H Frischauf
Publications and source records attributed to H Frischauf.
Myocardial studies in haemodialysis patients.
Myocardial perfusion was studied using Thallium-201 (Tl-201) after dipyridamol in 33 patients on maintenance haemodialysis. It could be shown that coronary artery disease was underestimated by clinical symptoms, 55 per cent of patients had abnormal Tl-201 scintigrams, whereas typical or atypical chest pain was present in only 33 per cent of the patients. Eleven patients died within a year of the scintigraphic study, which resulted in an average mortality rate of 7.7 per cent/year. The risk of developing fatal cardiovascular complications was higher in patients with an abnormal Tl-201 perfusion (7 of 18) than in those with a normal scintigram (1 of 15). Thus nuclear medicine procedures appear to be of diagnostic value in haemodialysis patients, which in addition may have prognostic implications.
Adult↗
[Behavior of renal filtration performance in the massive intraoperative administration of crystalloid solutions].
Renal function of 12 adult patients was studied pre- and postoperatively using tracer techniques in a black-box model. Chrom 51 EDTA was employed to determine extracellular fluid volume and glomerular filtration rate, Iodine 125-albumin to measure plasma volume. These patients who received during two 4-h periods pre- and postoperatively 3 ml/kg/h of a salt-sugar solution had a significantly increased extracellular fluid volume postoperatively. Glomerular filtration rate was also increased, plasma volume was significantly reduced and colloidosmotic pressure in spite of attempts to supplement albumin solution intraoperatively was found to be postoperatively reduced. Hemodynamic parameters were virtually unchanged postoperatively with the exception of a small but significant increase of cardiac index. It is concluded, that these patients who received 12 ml/kg/h of crystalloid solutions apart from colloid replacement of measured bloodloss intraoperatively through natural regulation were about to excrete this extra amount of fluid, which had been relocated in the extracellular space. This regime, however, might help to decrease the rate of oliguric perioperative renal function failure, which has a high mortality.
Adult↗
The use of 123I-labeled heptadecanoic acid (HDA) as metabolic tracer: preliminary report.
The feasibility of using 123I-heptadecanoic acid (HDA) as a metabolic tracer was studied. Different administration routes of HDA were compared. An intracoronary bolus injection was given to calves (n = 3), and an intravenous injection was given to patients (n = 4). In addition, we examined the influence of 4-h halothane anesthesia in calves and in patients the impact of an insulin (1.5 IU/kg) + glucose (1.5 g/kg) infusion on the myocardial kinetics of HDA. Data were accumulated with a scintillation probe in calves (t = 50 min) and a gamma camera in patients (t = 70 min). In calves after an intracoronary bolus injection of HDA the myocardial time-activity curve could be described by two exponentials. The mean elimination half-time of the initial phase (ta 1/2) was 7.3 min and that of the second phase (tb 1/2) was 35 min. The ratio of the size of the initial and second component at to was 0.93. Halothane anesthesia prolonged the elimination half-times and reduced the component ratio. The biphasic behavior of the myocardial time-activity curve was maintained in patients after intravenous administration of HDA under basal conditions (initial ta 1/2 = 8.4 min). However, during infusion of insulin + glucose the decline in the myocardial activity was prolonged and monoexponential. This data shows that insulin glucose, interfering with fatty acid metabolism, influences the myocardial washout of HDA, and thus support its use as a metabolic tracer.
Animals↗
[Health disorders caused by radiation].
The rapid development and distribution of radiation sources has given rise to an "Energy Pollution" paralleling the chemical contamination of the environment. It has become necessary to establish limits for the "non-ionizing radiation" as well as for the ionizing radiation to which attention has been given for a long time. The non-ionizing radiation now includes the non-ionizing electromagnetic waves - radio frequency, micro waves, optical radiation - and ultrasound. Specific effects of these different radiation qualities caused by variation in biochemical and biophysical characteristics of tissues as well as the related biological changes and the mechanism of radiation effects are discussed shortly. Some commonly occurring radiation sources are quoted.
Age Factors↗
[Reproducibility of repeated measurements using M-mode echocardiography, radionuclide ventriculoradiography and systolic time intervals].
The reproducibility of M-mode echocardiography, radionuclide ventriculography, and systolic time intervals (PEP/LVET) was studied in 16 patients with symmetrically contracting left ventricles and no signs of coronary heart disease. The values were determined four times in these 16 patients: twice each on day 1 and day 8 at an interval of 2-3 h. The mean EF and PEP/LVET values were nearly identical in all 4 repeat studies. There was a high correlation of echocardiographic and scintigraphic EF measurements (r between 0.90 and 0.96); the correlation between PEP/LVET and EF was considerably poorer (r ranging from -0.56 to -0.79). There was no difference in mean serial variabilities of EF for all repeated studies performed on the same day and on separate days for either echocardiography or radionuclide ventriculography. The mean variability of absolute EF for repeated studies was 2.9 +/- 2.4% for M-mode echocardiography and 3.4 +/- 2.4% for radionuclide ventriculography. To be attributed to nonrandom physiological alterations the absolute change in EF in an individual patient should be at least 8% for echocardiography and 9% for radionuclide ventriculography. The mean variabilities of PEP/LVET were different in studies performed on the same day and on separate days (0.03 +/- 0.02 vs 0.04 +/- 0.03, p less than 0.01). In 7 further patients the effect of dobutamine infusion was studied.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Evaluation of 99mTc-dichloro bis (1,2-dimethylphosphino) ethane (99mTc-DMPE) for myocardial scintigraphy in man.
99mTc-DMPE was used for myocardial scintigraphy in ten patients with coronary artery disease. As in 201T1 studies regional activity of 99mTc-DMPE was reduced in infarcted myocardium. However, activity accumulation of 99mTc-DMPE in the heart was faint, while that in the liver was prominent. The activity ratio of heart to liver improved with time, whereas that of heart to lung decreased. The scintigraphic quality was considerably worse in 99mTc-DMPE studies than in those with 201Tl, due to high background activity. Also the visualization of the ribs and sternum interfered with the interpretation of the scintigrams. From these results it appears that 201Tl remains still the agent of choice for myocardial perfusion scintigraphy.
Coronary Disease↗
Thallium-201 imaging after dipyridamole in patients with coronary multivessel disease.
In 60 patients with angiographically documented 2- or 3-vessel disease (at least 70%) thallium-201 images after dipyridamole (0.50 mg/kg bodyweight i.v.) and 4 h later were obtained. In 95% of the patients stress perfusion defects were found. In 48% of the cases scintigraphy correctly diagnosed the presence of multivessel disease, but in only 30% of the patients were all angiographically narrowed vessels detected. The reliability of the method was much higher in the detection of 'infarct stenoses' (96%) than of 'noninfarct stenoses' (46%). The regional sensitivity to assess stenoses of the left anterior descending artery (75%) and right coronary artery (73%) was greater than in stenoses of the left circumflex artery (37%). Thallium-201 scintigraphy after dipyridamole is a sensitive method for diagnosing the presence of coronary artery disease. The diagnostic value is severely limited however by the fact that coronary vasodilation may provoke perfusion abnormalities only in the most ischemic regions, whereas perfusion defects in other areas may not be detectable. Therefore this method does not allow the precise quantitation of all coronary stenoses in the majority of patients.
Adult↗
[Protection from ionizing radiation in medicine].
Radiation burden of medical personnel is low in trained medical staff. Higher doses can occur with therapeutic application of unsealed or sealed sources, if adequate shielding is not possible or not cared for or if radiation protection measures are not observed in work with higher activities of radionuclides. More important than immoderate structural alterations for shielding purposes is individual inspection with advice on the working place and optimisation of working methods, also in regard to the radiation protection. This is possible only by cooperation and by discussing risks and problems between the radiation protection officer and the working personnel in an overt manner, assuring the mutual understanding. Radiation protection concerning medical uses of radiation in the whole population and in patients especially is determined by the necessity of indication for the medical application of radiation, by quality control and lastly by the correct interpretation of results or consequences. The latter necessitates a good collaboration between nuclear medicine specialists and clinicians because of the individual particularity of the patient which must be considered in the evaluation of results.
Adenoma↗
[Diagnostic value of 201-thallium imaging following dipyridamole in patients with a normokinetic left ventricle].
In 100 patients with a normokinetic left ventricle 201-thallium imaging following administration of dipyridamole (0.50 mg/kg body wt. i.v.) showed a sensitivity of 67% (41/61) and a specificity of 95% (37/39) in diagnosing coronary artery disease. Exercise stress testing gave nearly equal sensitivity values (36/58 = 62%) with only slightly lower specificity (32/39 = 85%). The rate of true positive 201-thallium findings increased with the number of narrowed vessels (one vessel disease 50%, two vessel disease 63%, three vessel disease 94%); the extent of coronary artery disease was almost regularly underestimated with the scintigraphic method. Because of the low sensitivity a negative finding cannot exclude the presence of coronary artery disease, but the existence of three vessel disease can be considered improbable in patients in whom thallium scintigraphy findings are negative. Analysis following Bayes' theorem revealed the method to have a low diagnostic value in patients with either very low or high pretest probability for the disease; either a positive or a negative finding is of most use in a patient with low or average pretest probability of the disease (20-60%).
Coronary Disease↗
Plasma concentration of platelet-specific proteins and fibrinopeptide A in patients with artificial heart valves.
beta-Thromboglobulin (beta TG), platelet factor 4 (PF4), fibrinopeptide A (FPA), lactic dehydrogenase (LDH), and platelet count were evaluated in patients with bioprostheses and prosthetic heart valves. beta TG and PF4 were significantly elevated in both patient groups (p less than 0.001), whereas FPA was normal. There was no significantly difference in plasma concentrations of beta TG and PF4 between patients with prosthetic heart valves and bioprostheses. LDH levels were significantly (p less than 0.001) higher and platelet count lower (p less than 0.001) in patients with prosthetic cardiac valves. The data indicate that bioprostheses do not cause haemolysis or activation of the coagulation system. The findings that the plasma concentration of platelet-specific proteins were elevated, support the assumption that both types of valves cause platelet damage.
Adult↗
Transient accumulation of Tc 99m MDP in the liver.
A patient with multiple myeloma complicated by hypercalcemia is presented. During the state of an elevated calcium phosphate product a transient diffuse accumulation of Tc 99m MDP in the liver was demonstrable, whereas the demonstrated metastatic calcifications of the kidneys persisted after therapeutic reduction of the elevated ion product. This points to a difference in the formation of calcium phosphate precipitations in these organs. Accumulation of Tc 99m labelled bone seeking agents in the liver must not always mean severe liver damage or amyloidosis or tumour manifestation. An altered serum calcium phosphate balance has to be taken into account when interpreting scintigrams performed with bone seeking radiopharmaceuticals.
Bone and Bones↗
[Biphasic 201thallium scintigraphy after dipyridamole in mitral valve diseases (author's transl)].
The results of biphasic 201thallium scintigraphy after dipyridamole i.v. could neither prove nor exclude the presence of small focal lesions in the myocardium of 17 patients with mitral valve diseases. The frequent finding of a decrease in activity in the anterolateral myocardium is probably due to a relative increase in activity in the region of the inferior wall with superimposed areas of the papillary muscle and right ventricular myocardium. If the right ventricle is visualized in stress- or redistribution images, an increase in mean pulmonary artery pressure can be accepted. According to Cohen's criteria, a grade 2 or 3 virtually proves the existence of pulmonary hypertension, a grade 1 makes this finding rather probable. The possibility of pulmonary hypertension can not be excluded if the right ventricular myocardium is not visualized.
Adult↗
Comparison of two different biliary agents in healthy subjects and in patients with liver disease.
The kinetics of the iminodiacetic acids, dimethyl and diethyl IDA were studied in patients without and with liver disease. Diethyl IDA seems to be superior to dimethyl IDA in its diagnostic usefulness. It shows lower urinary excretion and a faster liver uptake, leading to more pronounced differences in liver peak time and in liver elimination half time and to faster visualisation of the gall bladder in patients with liver disease. The enterohepatic reabsorption is negligible as shown by enteral administration of the radiopharmaceutical and monitoring blood activity. Therefore it is not necessary to correct time activity curves of the liver for the IDA secreted into the gastrointestinal system. The most valuable diagnostic information with this substances may be gained in investigations on cholecystectomized patients with cholestasis.
Humans↗
Radiation exposure due to 99mTc and 131I manipulated in syringes.
Dose rates around and at the surface of disposable polypropylene syringes of 1 and 2 ml volume filled with 99mTc and 131I solutions were determined by thermoluminescence dosimetry. Data for the efficacy of 0.5 and 1 mm lead shielding of 99mTc and for the dose contribution due to beta- -radiation from 131I are given.
Humans↗
[Indication and value of erythrokinetic examinations in anemia].
As erythrokinetic studies are time consuming and costly, this technique should only be done to provide information which is unavailable through simpler tests. By means of discussion concerning the methodological procedure and obtainable information, the indications for erythrokinetic investigations with Cr 51 and Fe 59 are derived. Since the results should be interpreted together with the clinical and haematological findings, a close cooperation of the departments of nuclear medicine and haematology would be essential.
Anemia↗
[In vitro testing of human lymphocytes (author's transl)].
The use of surface markers for the characterization of various lymphocyte subpopulation today belongs to the standard techniques of immunological laboratories. Recently, functional in vitro testing of human lymphocytes has met with increasing interest. In this paper some of the relevant in vitro test systems such as the lymphocyte stimulation test, the determination of the B cell differentiation capacity in vitro and the demonstration of suppressor cell activity are discussed. Apart from a discussion of the results obtained by these techniques in normal, healthy individuals, the applicability of these techniques for studies in patients is dealt with.
B-Lymphocytes↗
Expression and specificity of FcIgG receptor sites on neoplastic lymphocytes.
We investigated the ability of an FcIgG receptor marker to discriminate between subtypes of malignant lymphoproliferative diseases that differed in their clinical presentations. A quantitative radioimmuno assay was established that enabled us to evaluate average receptor densities on a population basis. Surface receptors were first saturated with IgG complexes. The number of membrane associated IgG molecules was subsequently determined with 125I-staphylococcal protein A. Results obtained with this assay on a battery of malignant lymphocytes suggested that the range of receptor densities of malignant B and T cells might overlap each other but would correlate with the degree of tumor cell differentiation and the clinical stage of the underlying disease. This behavior limits the use of this marker in the characterization of the derivation of malignant lymphocytes; these findings, however, may be useful in the prognostic classification of lymphomas of known origin.
Binding Sites, Antibody↗