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Biomedical subjects

D Oldag

Publications and source records attributed to D Oldag.

At least 19 recordsLinked to original sources
PubMed1990

[Electrophoretic studies of the composition of peripheral mononuclear cells during operations with extracorporeal circulation].

The increased incidence of infections after operations can be connected with changes of the immunocompetent cells. Mononuclear blood-cells were investigated by means of the cell electrophoresis during and after operations under the extracorporeal circulation, because electrophoretically different cells correlate with several immunological phenotypes. A heavy decrease of the electrophoretic quick mobility cell population was found out on the first postoperative day above all. This change allows itself the interpretation by decreasing the T-lymphocytes connected to a relative increase of monocytes, B-cells, and immature T-cells. Besides a lower quotient of the quick and low mobility T-cells refers to a lower immunoregulatory quotient CD4/CD8 after operation. Changes of the cell composition becomes evident also in dependence on the bypass length and the blood supply.

Adolescent↗
PubMed1989

[Results of the differentiated use of catecholamines and vasodilators in the early post-bypass phase].

Presented are the results of a procedure to characterize the haemodynamic situation and the required therapy in the early post-bypass period by including haemodynamic parameters (Part, CVP, PLA, TPR, PVR, f, Cl) in a system of seven parameter constellations although directly measured values must be supplemented by clinical data. In this way situations with increased or normal cardiac output and pathological peripheral resistance can be more easily distinguished from situations with reduced cardiac output. The investigations were performed in 300 patients who underwent cardiac surgery in 1985 and 1986. In more than 80% of the patients increased volume alone was not able to end the bypass, and so therapy including catecholamines and/or vasodilatators was instituted. Due to a relatively intensive but specific treatment, a favourable result with a 3% mortality was achieved. The frequency of patients after coronary surgery, valve replacement or correction of congenital heart defects in the seven situations of parameters corresponded to the expected haemodynamic peculiarities. In the group treated with catecholamines only, including 34% of the coronary patients, no increased mortality occurred compared with the total number. In patients in whom the constellation of parameters required a treatment with catecholamines combined with vasodilators, a higher mortality of 8.6% occurred compared with the total result. Here patients are concentrated with whom a good surgical result could not be obtained or the changes of myocardial stimulation were exhausted. Our findings emphasize the importance of the following points for further practice: improvement of invasive monitoring to apply vasodilators more intensively especially in infancy, careful selection of patients for coronary surgery, reduction of negative inotropic drugs preoperatively in high risk patients for improving postoperative stimulation of the myocardium.

Adult↗
PubMed1987

[Catheter problems in the use of ventricular cardiovascular assist systems].

The prerequisite for efficient assist-ventricles and impulses in the pulsatile pumping function are sufficiently dimensioned afflux and flowing off connections. In systematic investigations on the hydraulic circulation model the cannulas from an internal parameter of 12 mm with a total length of the connection distance to the inflow and outflow valve, respectively, at the bypass ventricle of 30 cm proved sufficient for performing a volume of output of 5-6 l/min in clinic-relevant filling pressures in a hypodynamic circulatory situation. Connection cannulas for the heart-lung machine used in routine work are not sufficient in periodic filling and ejection processes in the pulsatile pumping function for an effective decompression and effective increase of the cardiac output. In case of an ECG-triggered mode of action of the ventricular assist-system an increase of frequency up to 130/min in after that incomplete filling of the assist-ventricle does not remarkably restrict the effectiveness of the assist-system.

Assisted Circulation↗
PubMed1987

[Experimental testing of the left-ventricular and biventricular assistant systems in dogs].

The left-ventricular (LVAD) and bi-ventricular assistant system (BVAD) were tested in dogs. Our hitherto existing experiences give information specially for the indication of LVAD and BVAD. The risk of a belated application of the LVAD exists in case of only a clinical control by pressure parameters for the degree of a cardiac insufficiency caused by coronary starvations. An aortic pressure of nearly 150/70 mm Hg could be reached by means BVAD on condition of heart fibrillation and a left-atrial pressure of 20 mm Hg. The aortic pressure and the left-atrial pressure decrease drastically after disconnection of the BVAD and these attain the initial values again very promptly after a new connection with the BVAD.

Animals↗
PubMed1984

[Animal experiments using the left-ventricular-assist system].

The left ventricular assist device (LVAD) was tested in 27 sternotomied dogs using hemodynamic parameters. The left ventricular failure was attained by the starvation of the coronary vessels. The use of cannulae and ventriculi fitting for the size of the animals, and a diastolic vacuum were an essential premise for an effective support of the left heart. By variation of the latent period, the systole duration, and the operating pressures were selected for optimal pumping conditions. The effectiveness of the LVAD was shown by the detected pressure and flow parameters.

Animals↗
PubMed1979

[Pre- and postoperative erythrocyte volume distribution curves in children with cyanotic heart defects].

The behaviour of the volume distribution curves (VVK) of red blood cells in children with cyanosed organic heart defect is reported by taking preoperative and postoperative observations as a basis. MCV determined from the volume distribution curve amounts to 80.3 micron3. If the volume distribution curves of the preoperative patient group are compared with the postoperative patient group (4 months) by means of the criteria DSmax, DS, inclination and dispersion, no significant changes can be identified. Therefore, shifting maturity divisions cannot be assumed in children with cyanosed organic heart defects, even in those with a preoperative hypoxia of a high degree.

Adolescent↗
PubMed1978

[Electron microscopical findings of the myocardium in Fallot's disease and of the ventricular septal defects (author's transl)].

Ultrastructural quantitative and qualitative investigations of the myocardium of 7 children with Fallot's disease and 3 children with a ventricular septal defect (VSD) have shown bizarre nuclei and a slight increase in the myofibril share of the volume (Fallot's disease: 51.22%; VSD: 56.85%). This may be interpreted as a sign of a cellular hypertrophy. The mitochondria have a proportion of 35.07% and 33.75%, respectively. The glycogen content is relatively high. The lipofuscin bodies originate mainly from mitochondria having a percentage of 1.43 and 1.67, respectively. Particular signs of a lesion could not be observed. From the ultrastructural findings on the morphology of heart muscle cells it can be deduced that operations of vitia may be safely carried out.

Adolescent↗
PubMed1978

[Electronmicroscopic changes in the myocardium of children with cyanotic heart diseases].

In 7 children with Fallot's tetralogy ultrastructural quantitative and qualitative investigations on the heart muscle were carried out. Bizarre nuclei and slightly increased volume of mitochondrial part indicated hypertrophy. The amount of mitochondria was 35.07 per cent. The content of glycogen is relatively high. The lipofuscin bodies, mainly originating from mitochondria, amount to 1.43 per cent. No essential damage is observed. From the ultrastructural findings can be concluded that surgery may be done without suspicion as to cardiac cell morphology.

Cell Nucleus↗
PubMed1977

[The pre- and postoperative 2,3-diphosphoglycerate concentration of erythrocytes in children with cyanotic heart disease].

The behaviour of 2,3-diphosphoglycerate concentration (2,3-DPG) of red blood cells of babies and children with cyanotic heart diseases is studied before and after shunt operations. In babies with cyanotic heart diseases at the age of up to 6 months an increase of 2,3-DPG-level and haematocrit (HCT) is seen. Later, the compensation of chronic hypoxia is effected by further increase of HCT at unchanged high 2,3-DPG-level. The 2,3-DPG concentration which is still increased after successfull shunt operations as compared with the normal value is considered as an effective adaptation mechanism to the residual hypoxia presenting only a small load on the circulatory system. The 2,3-DPG concentration alone does not represent a criterion for the assessment of chronic hypoxia.

Adolescent↗
PubMed1975

Quantitative changes of canine diaphragm muscle cells following electrostimulation.

1. In 12 dogs the right part of the diaphragm was stimulated 4, 5, 8, 11, and 14 weeks by means of a pacemaker. 2. Essential findings have been the increase of the amount of glycogen after 5 weeks, the increase of myofilaments per myofibril after 8 weeks, and the increase in the share of mitochondria in the 11th week. After 14 weeks all values have reached again their initial level as the result of an adaptation. 3. From the quantitative structural findings it can be taken that the diaphragm musculature is not changed by the electrostimulation in such a way that the functional preconditions for covering heart muscle deficiencies by diaphragm flaps are given.

Animals↗