2,3-diphosphoglycerate and oxygen supply of tissues in cardiosurgical diabetics.

THE MAIN AIM OF THE STUDY: The oxygen supply of tissues was studied under haemodilution in cardiosurgical diabetic and non-diabetic patients. METHODS: There were 30 cardiosurgery patients examined, 9 were patients with diabetes mellitus.and 21 were non-diabetic patients. Venous blood samples were examined preoperatively, intraoperatively and for 10 days after operation. RESULTS: Haemodilution caused a decrease in haematocrit values in both groups, as well as in the erythrocyte count and haemoglobin concentration. Postoperatively, an increase was recorded in haematological values in both groups, the values had not reached the baseline even by 10th day. Increased values of blood oxygen saturation and partial oxygen pressure during the operation returned to baseline in both groups in the postoperative days. Values of p50 did not change in both groups for the period of observation. CONCLUSION: The obtained data suggest that sufficient oxygen supply to tissues was ensured under haemodilution in cardiosurgery patients in both groups. These results confirm multifactorial dependence of blood oxygen transport to tissues (Tab. 1, Fig. 3, Ref. 13).

The assessment of erythrocyte deformability by filtration rate.

The aim of the study was to monitor the erythrocyte deformability as one of important factors securing the appropriate tissues perfusion in healthy subjects and diabetic patients with insulin dependent diabetes mellitus. Erythrocyte deformability was determined by the method of filtration and centrifugation, and the erythrocyte filtrability was calculated as a percentage of filtered erythrocytes out of the number of erythrocytes counted before centrifugation. Diluted blood suspensions were filtered by centrifugation through membrane filters with pores of 5 microm in diameter. The speed and duration of centrifugation of 1400 rpm and 5 min respectively were selected as the best ones for filtration due to the lowest value of the coefficient of variance. The values of the arithmetic mean and standard deviation of erythrocyte filtrability were 72.2 +/- 7.9% in normal subjects. In the group of diabetic patients with the long history of insulin therapy the values amounted to 69.1 +/- 4.4%. In diabetic patients, the average value of blood glucose was 11.7 mmol x L(-1), and the glycated haemoglobin concentration reached 9.04%. From the viewpoint of reference values, these facts indicate good compensation of diabetes mellitus. Other haematological values, namely erythrocyte count, haematocrit value, haemoglobin concentration and mean cell volume were within normal reference ranges. No difference between the groups of healthy subjects and diabetic patients was found. (Fig. 4, Ref. 18.)

The effect of selected membrane active substances on erythrocyte deformability.

Aminoguanidine improved the erythrocyte filterability by 4%, pyridoxyliden-aminoguanidine by 11% and pyridoxal by 13% in healthy subjects. In diabetic patients the aminoguanidine effect on erythrocyte filterability was improved by 7%, PAG effect by 9% and pyridoxal effect by 15% in comparison to the control group. The other investigated haematological variables in both groups were within the range of the physiological standard. All of the tested substances demonstrated a mild protective influence on erythrocyte elasticity both in healthy subjects and diabetic patients. Significant elasticity improvement was obtained only by pyridoxal (p<0.01) in patients with diabetes mellitus. (Fig. 4, Ref. 18.).

[Oxygen transport values in patients with surgery performed under extracorporeal blood circulation]. / Hodnoty parametrov transportu kyslíka u pacientov operovaných v podmienkach mimotelového krvného obehu.

The aim of the work was to study the O2-transport changes to tissues in cardio-surgical patients suffering from CAD and operated during extra-corporeal blood circulation (ECC). The changes of selected haematologic variables, 2,3-diphosphoglycerate (2,3-DPG) and ATP concentration, acid-base balance parameters with p50 calculation were measured in the venous blood samples taken before the operation, during the operation and on the 1st, 2nd, 3d, 5th, 7th and 10th day after the operation. From the obtained results follows, that extreme haemodilution causes significant decrease of the haematocrit value (Htc) by 35%, the value of haemoglobin (Hb) by 37% and the count of erythrocytes (Er) by 37% from the initial values. The count of reticulocytes (Ret) was increased by 52%. In the days after operation the increase in Htc values, the values of Hb and count of erythrocytes was observed, whereby the initial values were not reach even on the 10th day after the operation. The increase of the reticulocytes count by 33% prevailed to the 10th day after the operation in comparison with the initial values. 2,3-DPG concentration was increased between 3d and 10th day after the operation by 30% and ATP concentration between 5th and 10th day was increased by 23% from the initial values. Hb-O2 saturation (SpO2) and pO2 were increased already during the operation, the increase prevailed until the 7th day by 27%, pO2 until the 3d day by 39% from the initial values. Calculated values p50 did not change in the course of this study--they fluctuated in range +/- 0.04 kPa from the initial value 3.55 kPa. Supposing multifactorial character of Hb oxygenation and deoxygenation process it is possible to conclude, that the determined changes of observed parameters did not significantly influence O2-transport to tissues during ECC. (Fig. 3, Ref. 12.)

[Salivary testosterone and cognitive ability in children]. / Slinný testosterón a kognitívne schopnosti u detí.

There are suggestive data with indicate the link of testosterone levels with specific cognitive abilities in humans. As soon as during intrauterine development, testosterone is supposed to influence to organization of fetal specific brain structures. This influence is permanent and it is reflected in cognitive abilities during prepubetal period. In puberty, the testosterone level rapidly increases mainly in boys and it appears to influence the definitive development of cognitive functions. In this paper, results of the first four years of our logitudinal study are presented. Salivary testosterone levels in children were determined, and their effect on spatial ability was studied. Radioimmunoanalytical method of testosterone determination in saliva was developed, since saliva reflects free fraction of testosterone directly available for uptake by receptors in the central nervous system. The sampling of saliva is non-invasive and unstressful, which is important for relevant evaluation of cognitive performance. One hundred and forty-seven children (78 boys and 69 girls) at the ae of 8 to 12 were examined. The data received from intellectually gifted children attending the School for gifted children in Bratislava (100 measurements) were compared with the data received from age-matched children attending randomly chosen elementary schools (151 measurements). Lower salivary testosterone levels were found in intellectually gifted children of both sexes, and negative relationship between testosterone levels and cognitive abilities in preadolescent children was observed.

[The physiologic significance of 2,3-diphosphoglycerate and changes in its erythrocyte levels in an experiment]. / Fyziologický význam 2,3-difosfoglycerátu a zmeny jeho obsahu v erytrocytoch pocas experimentu.

The regulatory effect of 2,3-DPG on oxygen transport and binding to hemoglobin was analyzed. Under conditions of substitution hemodilution by isooncotic 3.4% Rheodextran (Spofa), changes in the content of 2,3-DPG in arterial and venous blood were enzymatically determined over several days. Reference values of 2,3-DPG were obtained in the studied series of dogs (2.05 +/- 0.74 x 10(-6) mol.ml-1 in whole blood 4.69 +/- 1.52 x 10(-6) mol.g-1 of erythrocyte volume, and 13.39 +/- 2.82 x 10(-6) mol.ml-1 of hemoglobin). In anesthetized animals the content of 2,3-DPG in arterial blood was significantly higher (6.28 +/- 0.84 x 10(-6) mol.ml-1 of erythrocyte volume) than in venous blood (6.01 +/- 0.80 x 10(-6) mol.ml-1 of erythrocyte volume). At substitution hemodilution the 2,3-DPG content in erythrocytes of venous blood decreased from 5.46 +/- 0.67 to 4.97 +/- 1.31 x 10(-6) mol.ml-1 of erythrocyte volume. The subsequent increase to 6.04 +/- 0.71 x 10(-6) mol.ml-1 of erythrocyte volume was achieved by nonlinear increase over the following days, at persisting low hemoglobin content in blood.