Biomedical subjects

K Kletter

Publications and source records attributed to K Kletter.

At least 73 records · Page 4Linked to original sources

PubMed1985

[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↗

PubMed1984

[Radionuclide studies in chronically hemodialyzed patients. Bone scintigraphy for the evaluation and control of renal osteopathy].

The clinical applicability of bone scintigraphy (Tc99m MDP) was evaluated in 42 patients on maintenance hemodialysis. Typical scintigraphic findings are shown which were related to hormonal and biochemical parameters of calcium and phosphate metabolism. Visual grading of representative regions for metabolic bone disease in bone scans was compared to scintimetry which applies a bone to soft tissue ratio to grade osseous abnormalities. It could be shown that visual interpretation and grading of the findings according to a score is sufficient to assess the degree and extent of renal bone disease. Semiquantitative analysis of bone scintigrams by scintimetry did not improve the diagnostic information.

Adult↗

PubMed1984

[Radionuclide studies in chronically hemodialyzed patients. Diagnosis of coronary disease using Tl-201 myocardial scintigraphy after administration of dipyridamole].

Myocardial perfusion using Tl 201 after dipyridamol was evaluated in 33 patients on maintenance hemodialysis. In addition radionuclide angiography (RNA) was performed following hemodialysis to assess left ventricular function. RNA was done at rest in 31 patients and repeated in 13 after isometric exercise. All patients studied showed no signs of congestive heart failure. 55% of the patients had abnormal Tl 201 scintigrams, whereas coronary artery disease (CAD) was underestimated from clinical symptoms alone (33%). The incidence of an abnormal Tl 201 finding increased with the duration of hemodialysis treatment. However, in the symptomatic patients angina appeared already in the first (45%) or second year of hemodialysis treatment. 39% of patients with abnormal Tl 201 findings died within a year following scintigraphic examination. From 15 patients with normal Tl 201 scans 26% died. Overall mortality rate was above that in asymptomatic or mildly symptomatic patients with CAD, averaging about 7.7% per day. The major causes of death were cardiovascular complications in patients with abnormal Tl 201 findings. In all patients left ventricular ejection fraction (LVEF) was within the normal range following hemodialysis. Thus in our patients LVEF appeared not as an important prognostic characteristic. However, ventricular function can be impaired following exercise. As expected, in 7 patients with CAD (abnormal Tl 201 scan) isometric handgrip induced a mean decrease in LVEF by 11% and abnormalities in regional wall motion. However, also in 4 of 6 patients with normal Tl 201 scintigrams LVEF decreased following isometric exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1984

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↗

PubMed1984

[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↗

PubMed1983

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↗

PubMed1983

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↗

PubMed1983

[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↗

PubMed1983

[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↗

PubMed1982

[Androgen-producing adrenal adenoma in an 18 year-old woman: diagnosis by gas-chromatographic steroid analysis, histology and postoperative course].

Gas-chromatographic analysis of the urinary steroids in an 18 year-old girl with primary amenorrhoea and hirsutism revealed markedly elevated excretion of androsterone, etiocholanolone, dehydroepiandrosterone, and androstendiole, both under basal conditions and after oral dexamethasone (0.5 mg q.i.d. for three days). Adrenal scintigraphy revealed the presence of a tumour of the right adrenal gland, which was subsequently removed by unilateral adrenalectomy. Histologically, the tumour showed marked anisocytosis, but since there was no evidence of capsular or angioinvasion or of mitotic activity, it was classified as an adrenocortical adenoma. Postoperatively the patient showed regression of the virilizing syndrome and normal menstrual bleeding. Urinary steroid excretion has remained normal for four years after adrenalectomy. Androgen-producing tumours must be considered as a possible cause of hirsutism in young females and should, thus, be excluded in each case. Analysis of urinary steroids by gas chromatography is a valuable tool in accomplishing this task.

Adenoma↗

PubMed1982

[Endemic goiter in Austria. Is iodine deficiency the primary cause of goiter?].

In spite of government-regulated iodide admixture to table salt, the incidence of goiter is still high in Austria. Iodine excretion and thyroid function were therefore investigated in 80 patients suffering from ordinary goiter in whom thyroid size and resulting symptoms had increased lately. 25 euthyroid non-goitrous subjects served as controls. 48% of the goitrous patients investigated presented with iodine excretion of less than 70 micrograms/24 h, suggesting an insufficient iodine supply. Thyroid I131 uptake, basal and TRH-stimulated plasma TSH concentrations, and serum T3 levels were higher, whereas serum T4 levels were lower in these patients than in goitrous patients with higher iodine excretion and non-goitrous controls. Iodine deficiency thus appears to be of pathogenetic relevance in about half of the goitrous Austrian population. Other factors enhancing goiter development seem to assume particular importance in goitrous patients with a sufficient iodine supply.

Adolescent↗

PubMed1982

[Effect of parenteral administration of fat on the glucose and fat metabolism in acute pancreatitis].

Glucose intolerance is well known in acute pancreatitis. The question of this study was to clarify, if fat used partly instead of glucose in the parenteral nutrition of these patients allows to reduce the insulin necessary to control the blood glucose. A second question was if hypertriglyceridemia is caused by long term infusion of fat in such patients. 10 patients with acute necrotising pancreatitis were divided in two groups: group I (5 patients) were infused with a parenteral nutrition with fat, group II (5 patients) with a parenteral nutrition without fat. As parameters the amount of insulin needed to maintain the blood glucose at levels less than 200 mg% and the serum triglycerides were used. The blood glucose was controlled three times a day. For statistical evaluation the Student-t-test was used. The patients in group I (parenteral nutrition with fat) were infused 44 days and received insulin on 40 days. 69 units insulin/day were needed with a glucose dose of 243 g/day. The insulin dose per 100 g glucose was 29.9 U. The fat dose was 74 g/day. Group II (parenteral nutrition without fat) was infused 45 days and received insulin on 38 days. 103 units insulin/day were needed metabolized 295 g of glucose. The insulin per 100 g glucose was 28.7 units. The dose of insulin per 100 g glucose was not different between the two groups. In 1 patient a hypertriglyceridemia occurred after infusion of fat and disappeared immediately after withdrawal of the fat infusion. In the other patients no hypertriglyceridemia occurred during fat infusion. The parenteral infusion of fat has no influence on the glucose intolerance of patients with acute necrotising pancreatitis.

Acute Disease↗

PubMed1981

Exposure to X-rays during small bowel biopsies in children.

Peroral small bowel biopsy is a decisive step in the diagnosis of coeliac disease and is performed frequently. The patient's exposure to ionizing radiation during fluoroscopic control therefore deserves consideration. Compared to data in the literature, the biopsy method employed at the University Children's Hospital in Vienna achieves a markedly shorter duration of fluoroscopy. These values were registered during 1039 biopsies. In 439 examinations the exposure area products were also documented In 10 consecutive biopsies additional measurements were carried out by lithium fluoride thermoluminescence dosimeters attached to the patient. Expert biopsy-technique with precise and thoughtful use of modern fluoroscopes on the one hand, and critical self-control by routine documentation of the exposure area product and duration of fluoroscopy on the other can markedly reduce the patient's exposure to X-rays.

Biopsy↗

PubMed1981

Adrenal Size and function after irradiation with 131I-6 beta-Iodocholesterol in rabbits.

Administration of high doses of 131I-6 beta-iodocholesterol to rabbits is followed by marked size reduction of the adrenal glands with concomitant changes of the histological structure and with a decrease of serum cortisol. Stimulation of 131I-6 beta-iodocholesterol uptake into the adrenals by additional administration of ACTH had only a minor additional effect on adrenal weight. However, with further accumulation of labeled cholesterol in the adrenals the radioactivity was reduced in blood urine, and the ovaries.

Adrenal Glands↗

PubMed1981

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↗

PubMed1981

[Thallium-201-myocardial imaging after high dose dipyridamole (author's transl)].

Biphasic thallium-201-myocardial imaging was performed in 100 patients undergoing coronary angiography. The images were obtained in several views after the administration of dipyridamole (0.50 mg/kg body weight) and 4 hours later. 24 patients had normal coronary arteries or insignificant stenoses, in 74 patients a 70-percent or greater stenosis of one or more coronary arteries was present. 55 transmural myocardial scars were diagnosed by left ventriculography in 53 patients. The described method showed a sensitivity of 93 percent and a specificity of 96 percent in the detection of patients with significant coronary artery stenoses. Irreversible perfusion defects were found in 91 percent of myocardial scars, in additional 7 percent the scintigraphic defects were reversible. In patients with multivessel disease and transmural infarctions, only one third of non-infarction-related stenoses were recognized. The number of angiographically stenotic coronary arteries could be determined scintigraphically only in a minority of the cases. The regional sensitivity in the assessment of LAD and right coronary artery stenoses was higher than for the left circumflex artery (75%, 80%, and 48% resp.), the specificity was equally high for all three vessels (96%, 99%, 100%).

Coronary Disease↗

PubMed1980

[The effect of the calciumantagonist dimeditiapramine on thallium-201 myocardial perfusion during exercise in patients with coronary heart disease (author's transl)].

The effect of dimeditiapramine (Ro 11-1781), a new calciumantagonist, on thallium-201 myocardial perfusion during exercise was studied in a double-blind trial with 10 patients suffering from coronary heart disease. Treatment with a single intravenous dose of 1 mg/kg body weight resulted in a significant regional thallium-201 perfusion increase in 8 out of 10 patients. These results correspond with the clinically observed decrease in exercise-induced angina and ischaemic ECG alterations. The findings indicate that dimeditiapramine might be a useful anti-anginal drug.

Aged↗

PubMed1980

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↗