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Biomedical subjects

J Holan

Publications and source records attributed to J Holan.

At least 19 recordsLinked to original sources

[Clinical evaluation of a new radiopharmaceutical agent 99mTc-mercaptoacetyltriglycine (MAG3)].

In the present clinically oriented study the authors checked the properties of 99mTc-mercaptoacetyltriglycine (MAG3), the new radiopharmaceutical for dynamic scintigraphy of the kidneys, in a group of 30 patients. They positively value particularly the high quality of visualization of the parenchyma and the urinary tract, the pharmacokinetic properties similar to those of 131I-orthoiodhippurate and the capability of representation of the kidneys with their markedly decreased function. They examined the take-up of the pharmaceutical in the liver, which is slightly more marked with the worsening tubular function and partly depends also on the length of the time interval between the preparation and administration of MAG3. No significant changes were found in the clinical and principal laboratory parameters after its administration. In conclusion, the authors point out to advantageous properties of the novel radiopharmaceutical for clinical use in our conditions.

Adolescent↗

[The significance of a new radiopharmaceutic agent, 99mTc-mercaptoacetyltriglycine (MAG 3), in the diagnosis of diseases of the kidneys and urinary tract in children].

Using the method of dynamic scintigraphy of the kidneys by means of a new radiopharmaceutical preparation, 99mTc--mercaptoacetyltriglicide [MAG 3], the authors examined 35 children with various urological and nephrological diseases. In indicated cases the examination was supplemented by administration of a diuretic, further projections or indirect mictional cystography. The authors assessed normal parameters of functional curves and their normal extent in a group of 18 healthy kidneys. They did not find a significant difference, as compared with results obtained by means of 131I-OIH. The assessed values of global clearance attained 66% of the 131I-OIH clearance values. In 60% of the patients the visualization of the parenchyma and in 80% the visualization of the efferent urinary pathways was better than when 99mTc-DTPA was used. In all instances the scintigrams were better than when 131I-OIH was used. The new radiopharmaceutical preparation combines the advantages of technetium-labelled preparations and the favourable pharmacokinetic properties of hippuran. It is suitable for quantification of tubular secretion. It is superior to hitherto used substances as regard the quality of visualization and in particular the lower radiation load. Therefore it is particularly suited for paediatric practice.

Adolescent↗

Relationship between platelet aggregation and plasma beta-thromboglobulin levels in arterio-vascular and renal diseases.

The incidence of second wave of platelet aggregation induced by a small dose of ADP (1 mumol/l) was compared with plasma levels of beta-thromboglobulin in 81 normal individuals, 34 patients with acute myocardial infarction, 11 patients with acute cerebrovascular disease and 26 patients with renal disease. Platelet hyperaggregability was observed in 7% of normal individuals. Plasma levels of beta-thromboglobulin were higher in normal individuals over 60 years of age (48 vs. 32 micrograms/l). In contrast, hyperaggregability was observed in 79% of patients with acute myocardial infarction and in 64% of those with acute cerebrovascular disease. Median plasma levels of beta-thromboglobulin were also significantly elevated in patients with acute myocardial infarction (82 micrograms/ml) or acute cerebrovascular disease (99 micrograms/l). Levels of beta-thromboglobulin in plasma were significantly higher in those patients who demonstrated hyperaggregability. In patients with renal disease only 12% had signs of hyperaggregability. Nevertheless their plasma levels of beta-thromboglobulin were elevated (76 micrograms/l) and correlated with the serum creatinine values. These investigations indicate that patients with acute myocardial infarction or stroke have hyperreactive platelets and evidence of increased platelet inactivation in the circulation. However, evaluation of increased levels of beta-thromboglobulin requires consideration of renal function.

Adenosine Diphosphate↗

Investigations on platelet function in diabetes mellitus.

Investigations on the platelet function in diabetes mellitus were performed on 28 patients with insulin-dependent diabetes and in 33 healthy controls of similar age. In the diabetic patients it was possible to induce 50% of maximal aggregation by lower concentrations of adenosine diphosphate or arachidonic acid than in the controls. In the presence of N-ethyl maleimide, platelets from diabetic patients produced significantly more malondialdehyde than those from normal controls. After addition of arachidonic acid the platelets from the diabetic patients also synthesized more thromboxane B2. This synthesis of thromboxane was inversely correlated to the minimal concentration of arachidonic acid necessary to induce 50% platelet aggregation. Circulating platelet aggregates were more common in the diabetic patients than in the controls. Plasma levels of beta-thromboglobulin and platelet factor 4 were raised in parallel in the diabetic patients and correlated with the increased production of thromboxane B2 by the platelets from the same patients. Platelets from patients with diabetes thus demonstrated signs of hyperreactivity both in vivo and in vitro. This may be of clinical importance for the development of vascular complications in this disease.

Arachidonic Acid↗

Influence of cis-platinum on some platelet functions in vitro.

Cis-platinum added to citrated platelet rich plasma in vitro did not influence the aggregation of the platelets, their adhesion to glass, their release of platelet factor 4 or availability of platelet factor 3 and acid phosphatase. Neither any effect on the uptake of 14C-serotonin, the reptilase clot retraction or the coagulation system has been observed.

Blood Platelets↗