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Biomedical subjects

R Fridrich

Publications and source records attributed to R Fridrich.

At least 37 records · Page 2Linked to original sources
PubMed1984

[Thallium scintigraphy of the thyroid as an alternative procedure for the demonstration of functionally silent thyroid tissue].

The efficacy of 201-thallium thyroid scintigraphy in nonvisualization of one or both thyroid lobes on 123I scan was evaluated prospectively in 38 patients with benign thyroid disease. In 17 of the 18 patients with autonomous toxic adenoma (Plummer's disease) the suppressed thyroid tissue was visualized by 201Tl scintigraphy. In one patient this method failed. A further 7 patients had partially decompensated adenomas demonstrated by both 123I and 201Tl scintigraphy. Homogeneous 201Tl uptake was observed in all 9 patients with bilateral subacute thyroiditis and depressed iodine uptake. Likewise, visualization of the thyroid was possible in the 3 patients with iodine blockade. 201Tl scintigraphy of the thyroid has substantial advantages over TSH stimulation and can be performed in all cases with diminished or suspended iodine metabolism.

Humans↗
PubMed1984

Antianginal drug effects on normal, ischemic and scar myocardial segments in man.

In order to assess acute effects of nitroglycerin, nifedipine and metoprolol on normal, ischemic and scar myocardial segments in man, non-invasive hemodynamic and radionuclide measurements of left ventricular function were performed. Sixteen patients with single left anterior descending (LAD) disease were studied at rest and during exercise: 9 patients with angina and exercise-induced ischemia (LAD stenosis) and 7 patients with previous transmural myocardial infarction and no ischemic changes at thallium imaging (LAD occlusion). Effects on regional ejection fraction were compared between involved antero-septal and normal postero-lateral areas. Global ejection fraction at rest was unchanged after nitroglycerin, increased after nifedipine and decreased after metoprolol. In patients with ischemia, improvement in exercise ejection fraction after all drugs was due to increased regional ejection fraction in ischemic segments, i.e. a real anti-ischemic effect could be demonstrated. In regions of myocardial scar, regional ejections fraction was not changed after either drug. In normal areas, regional ejection fraction remained unchanged after nitroglycerin and nifedipine but decreased after acute beta-blockade. Despite the very similar anti-ischemic effects of all drugs, underlying hemodynamic mechanisms were quite different: Reduction in preload and afterload after nitroglycerin, vasodilatation and reflex sympathetic activity after nifedipine and reduction in double product and contractility after metoprolol. Thus, the mode of action of nitroglycerin, nifedipine and metoprolol on normal, ischemic and scar myocardial segments could be demonstrated in man. Non-invasive antianginal drug testing as shown in this study should allow optimal medical therapy for patients with chronic ischemic heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Different actions of deferoxamine and iron on Ga-67 abscess detection in rats.

The contrast-enhancing properties of iron (Fe) and deferoxamine (DFO) in abscess imaging with Ga-67 citrate were compared in rats bearing turpentine-induced abscesses. Iron administration shifted Ga-67 from plasma into tissues such as muscle and fat. As a result, the abscess-to-plasma ratio increased whereas the abscess-to-muscle ratio decreased. DFO enhanced the abscess-to-muscle and abscess-to-plasma ratios by increasing urinary Ga-67 excretion. In contrast to Fe, DFO removed abscess-bound Ga-67, thus representing a disadvantage of DFO compared with Fe. As a result, the abscess-to-plasma ratio was more effectively enhanced by Fe than by DFO. We conclude that abscess imaging with Ga-67 citrate may be improved by administration of Fe for detection of abscesses masked by blood activity, or DFO for detection of abscesses surrounded by muscle tissue.

Abscess↗
PubMed1983

[Comparison between the intravenous TRH-test and the T4-thyroid suppression test for the diagnosis of borderline hyperthyroidism].

In a prospective study of 60 patients with T3 and/or T4 values within +/- 10% of the upper limit of normal, the suppressibility of thyroid storage values before and after oral administration of 3 mg L-thyroxine was tested and compared with the results of an intravenous TRH test. In 46 patients the results of the two methods agreed (77%): in 31 patients (52%) radioiodine uptake could not be suppressed nor TSH stimulated in the TRH test. Physiological suppression of the storage values in normal TSH stimulation after TRH as a sign of completely euthyroid function was present in 15 (25%). In the remaining 14 patients, 13 had a suppressed TRH test. In all patients radioiodine uptake could be suppressed either normally (above 50%) or partially (20-30%). A normal T4 suppression test in the absence of TSH rise after TRH indicates that biologically active TSH is circulating, even though not demonstrated by radioimmuno-assay. A normal T4 suppression test is an important argument against treating a given case of hyperthyroidism. The T4 suppression test reveals smooth gradation between euthyroid and hyperthyroid states. If the TRH test is normal one can assume a physiological T4 suppression test and no further tests are needed. If the TRH test is negative and there is only slight elevation of the thyroid hormones, the T4 suppression test is indicated before definitive treatment of hyperthyroidism is initiated.

Adult↗
PubMed1983

[Thyroglobulin as a tumor marker and thallium scintigraphy for the course control of differentiated thyroid cancer].

The usefulness of measurement of serum thyroglobulin (TG) concentration and whole body 201-thallium scintigraphy for follow-up were evaluated prospectively in 80 patients with differentiated thyroid cancer. All patients had undergone thyroidectomy and 131-iodine ablation. In 74 patients without residual thyroid tissue and a negative whole body thallium and/or iodine scan, the TG concentration in plasma was undetectable. In 5 of the remaining 6 patients, TG was measurable while the patient was receiving T3 therapy and undetectable in one. After 1 and 2 weeks off T3, TG increased in all 6 patients in parallel with TSH. Of 5 patients with abnormal 201Tl scintigraphy, 2 have residual local tissue and 3 distant metastases. Of these cases, 131I scintigraphy detected metastases in only one and local tissue in 2 patients. It is concluded that 1. TG is TSH-dependent and increases after withdrawal of T3 replacement therapy. 2. TG measurements under T3 replacement therapy are less sensitive than measurements made after withdrawing T3. 3. 201Tl scintigraphy can replace 131I scintigraphy in follow-up controls. 4. The combination of serum TG and 201Tl scintigraphy seems to be superior to either one alone and can be performed while patient is on replacement therapy.

Humans↗
PubMed1982

Some chemical aspects of labeling human fibrinogen with 99m-technetium.

Human fibrinogen was labeled with 99m-Technetium. Tin(II)-chloride in citric acid served as reducing agent for the pertechnetate-ion, eluted from a Mo-Tc-generator. Before adding the fibrinogen, the citric acid was always neutralized with sodium hydrogen carbonate. The influences on the quantity of fibrinogen bound 99m-Tc of the relative concentrations of Sn(II), fibrinogen and sodium hydrogen carbonate, of the reaction time and temperature were tested by thin-layer chromatography. The reaction temperature of 28 degrees C showed an optimum of fibrinogen bound 99m-Tc for the reaction time from 1 and 2 hours. With a reaction time of 30 minutes not enough 99m-Tc was bound to fibrinogen, the doubling of the reaction time from 1 to 2 hours showed only an increase of binding of less than 4%. The concentration of Sn(II) with respect to the fibrinogen concentration showed no influence on the quantity of fibrinogen bound 99m-Tc at low Sn(II)-concentrations. At values higher than 34 times of the fibrinogen concentration a decrease of the quantity of bound 99m-Tc was observed. The concentrations of sodium hydrogen carbonate showed no influence on the quantity of fibrinogen bound 99m-Tc but on the clottability of fibrinogen, the pH of the solution must be approximately 7.5. In 3 parallel and independent experiments under optimized conditions (1 hour at 28 degrees C, molar ratio of Sn(II) : fibrinogen = 8.5, pH = 7.5) 89.97 +/- 0.92 % of 99 m-Tc were bound to fibrinogen. Controls of these results by column chromatography showed a binding of 81.08 +/- 1.47 % of 99m-Tc to fibrinogen. The clottability of fibrinogen tested by the method of Clauss (1) was entirely preserved.

Bicarbonates↗
PubMed1982

[In vitro and in vivo diagnosis of borderline hyperthyroidism].

The evaluation of "preclinical hyperthyroidism" includes laboratory and in vivo tests. The measurements of circulating total thyroxine (T4) and total triiodothyronine (T3) depend on the plasma concentration of thyroid hormone binding proteins. A simple approach, the calculation of the free T3 index (FT3I) and the augmented FT3I (aFT3I) from total T3 and T3-resin uptake corrects the total serum T3 for variation in thyroid hormone binding capacity. In a group of 95 patients with border-line elevated T3 levels we have correlated the results of FT3I and aFT3I with clinical, biochemical and radioisotope findings. It was shown that in patients with moderate elevation of T3 the FT3I and aFT3I are capable of distinguishing clearly between the euthyroid and hyperthyroid range. To detect an imbalance in the hypothalamic-pituitary-thyroid axis either the T4-suppression test or the TRH-test could be used. In 60 patients with "preclinical hyperthyroidism" we have compared both of them. In 77% of the patients the T4-suppression test and i.v. TRH-test provided concomitant results. In 13 patients without response to the i.v. TRH-test 7 showed a definite (more than 50%) and 6 a partial suppression (10-40%) of radioiodine uptake. This suggests that there is no sharp distinction between hyper- and euthyroidism.

Female↗
PubMed1980

[Improved thyroid diagnosis in borderline hyperthyroidism by determination of free T3 index].

The measurements of circulating total thyroxine (T4) and total triiodothyronine (T3) depend on the concentrations of thyroid hormone binding proteins, especially TBG. A simple approach, the calculation of free T3 index (FT3I) and augmented FT3I (aFT3I) from total T3 and T3-resin uptake, corrects the total serum T3 for variation in thyroid hormone binding capacity. In a group of 95 patients with borderline elevated T3 levels (3.0-4.5 nmol/l) we have correlated the results of FT3I and aFT3I with clinical, biochemical and radioisotope findings: in a subgroup of 23 euthyroid females taking oestrogens (group A1) and in 22 other patients with TBG elevations (independent of oestrogens, group A2) the results for total T3 were within the slightly hyperthyroid range (3.32 +/- 0.3 and 3.26 +/- 0.24 nmol/l respectively), but FT3I was always within the normal range. In contrast, FT3I was clearly elevated in 50 hyperthyroid patients (group B) compared to the total T3 (4.6 +/- 0.6 and 3.9 +/- 0.4 nmol/l respectively). An even better discrimination was obtained by calculation of augmented FT3I. It is concluded that in patients with moderate elevations of T3 the FT3I and aFT3I are capable of distinguishing clearly between the euthyroid and hyperthyroid range. The estimation is thus indicated in all patients with changes in thyroid hormone binding protein concentration and is of great value in confirming or ruling out the diagnosis of T3-toxicosis, T4-toxicosis and in all cases of "preclinical" or borderline hyperthyroidism.

Diagnosis, Differential↗
PubMed1980

[Can ischemia-induced wall motion abnormalities of the left ventricle be predicted by non-invasive thallium-201 scintigraphy? Comparison with the ventriculography test].

To assess the relation between stress-induced perfusion defects and wall motion abnormalities (WMA), 20 patients were studied by thallium-201 (201Tl) scintigraphy and cineventriculography at rest and during exercise. Of 100 analyzed segments, 63 were normal while 13 showed constant (scar) and 24 reversible (ischemia) perfusion defects. At peak exercise, 85% of the scar and 80% of the ischemic segments corresponded to abnormally contracting wall segments. There was a marked correlation between the extent of ischemia and the degree of WMA. The increase in abnormal scintigraphic and angiographic segments from rest to exercise was parallel by a significant deterioration in left ventricular function. It is concluded that (1) ischemic perfusion defects detected by 201Tl scintigraphy correlate well with exercise induced wall motion abnormalities, and (2) the localization, extent and degree of WMA can be predicted by non-invasive 201Tl scintigraphy.

Coronary Disease↗
PubMed1980

[Myocardial perfusion scintigraphy and radionuclide angiography for the evaluation of outpatients with suspected coronary disease].

Combined ECG/myocardial perfusion szintigraphy (MPS) exercise tests were performed in 82 out-patients with suspected CAD who eventually underwent left heart catheterization. The sensitivity of MPS as compared to ECG was higher in patients with angina (86% vs. 67%) as well as in patients with atypical symptoms (63% vs. 25%). Here MPS was also more specific than ECG (86% vs. 68%). Combination of both tests improved sensitivity even more. The comparison of radionuclide and contrast ventriculography in 20 patients studied at rest revealed an excellent correlation (r = 0.90). Changes in radionuclide ejection fraction during exercise in 60 subjects showed significant differences between normals (increase of greater than 10% above resting level) and patients with CAD (decrease in patients with angina, no significant change without angina). Methods and indications are briefly discussed in the light of this experience.

Coronary Disease↗
PubMed1980

[Vitamin status in diabetic neuropathy (thiamine, riboflavin, pyridoxin, cobalamin and tocopherol)].

Investigations on the vitamin pattern of diabetic neuropathy: thiamine, riboflavin, pyridoxine, cobalamin and tocopherol. The contents of the vitamins mentioned above have been measured in the blood of 119 patients (53 diabetic neuropathies, 66 diabetics without neuropathy). The incidence of neuropathy shows a strong correlation with the duration of the diabetic state, but not with sex, nor with concomitant diseases such as adipositas, hypertension, heart and circulatory diseases, except retinopathia diabetica. Most of the diabetics in our study are well supplied with vitamins B1, B2, and E; B6 and B12 are occasionally low, but there is no statistically relevant difference between diabetic controls and neuropathies. Adipose patients have neither a markedly different vitamin content nor a different calory uptake from non-adipose patients. A general trend towards reduced total calory uptake is seen in old age, men (lower protein intake) and women (lower carbohydrate intake) obviously differing somewhat in their habits. The influence of therapy on the vitamin pattern is not clear cut, except for patients under diet and biguanide-therapy showing a higher proportion of low or subnormal B12 values. The increased frequency of neuropathies in patients treated with sulfonyl-urea approaches only the limits of significance and needs further investigations.

Diabetes Complications↗
PubMed1980

Dihydroergotamine and heparin or heparin alone for the prevention of postoperative thromboembolism in gynecology.

The efficacy of combined dihydroergotamine and heparin (DHE-heparin) medication (2500 IU sodium heparin and 0.5 mg DHE, both given subcutaneously twice daily) or low doses of heparin (5,000 IU of sodium heparin given subcutaneously thrice daily) in preventing postoperative thromboembolic complications was investigated in a prospective, randomized trial in 125 patients over the age of 40 years undergoing elective major gynecological surgery. The I125-fibrinogen uptake test was used for the diagnosis of deep vein thrombosis. There was no statistically significant difference in the incidence of thromboembolism between the groups. Major bleeding occurred less often (p < 0.05) in the DHE-heparin group.

Adult↗
PubMed1980

Prevention of postoperative thromboembolism by dextran 70 or low-dose heparin.

The efficacy of intravenous infusion of dextran 70 or subcutaneous administration of low-dose heparin in preventing postoperative thromboembolic complications has been investigated in a prospective randomized trial. During part 1 of the study, 232 patients over the age of 40 years who were undergoing major gynecologic surgery underwent a complete test protocol. The 125I fibrinogen uptake test (FUT) was used for the diagnosis of deep vein thrombosis (DVT) in 117 patients in the dextran and 115 patients in the heparin group. Heparin was significantly more effective than dextran for reducing DVT (P less than .001). During part 2 of the study no FUT was done but the incidence of clinical and fatal pulmonary embolism (PE) and the number of complications were studied. Of 444 patients (parts 1 and 2) 1 fatal and 2 nonfatal pulmonary emboli were diagnosed. All the emboli occurred in the dextran group. The benefit: hazard ratio appeared to favor heparin for the prophylaxis of DVT.

Adult↗
PubMed1980

Hemodynamic changes in placenta, myometrium and heart after administration of the uterine relaxant ritodrine.

The action of the uterine relaxant ritodrine on placental, myometrial and cardiac blood pools has been examined during spontaneous and oxytocin-induced uterine activity. 113mIndium was injected intravenously and the blood pools were measured by recording gamma-activity externally. After i.v. injection of Ritodrine, the typical blood pool changes in labor were inhibited. Thereafter, placental and myometrial blood pools increased more than due to inhibition of labor alone. Simultaneously, there was a corresponding decrease in cardiac blood pool indicating an increase in cardiac output. The rapid inflow of blood in the uteroplacental region after Ritodrine indicates an improved hemodynamic situation. This action could be of benefit in emergency situations in a hyperactive ischaemic uterus during labor.

Coronary Circulation↗