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Biomedical subjects

O Elert

Publications and source records attributed to O Elert.

54 records · Page 3Linked to original sources
PubMed1981

[Haemostatic changes related to extracorporeal circulation (ECC) (author's transl)].

After-bleeding not due to surgery following extracorporeal circulation (ECC) in open heart surgery has its origin in disorders of platelet number and function as well as in changes of the haemostatic balance. Not only are the plasmatic factors of the coagulation and the fibrinolytic system of importance but also their inhibitors which tend to avoid dysfunctions and overshooting reactions. To detect early the danger of an excessive bleeding tendency assays of fibrinogen (factor I), prothrombin (factor II), antithrombin III (AT III) and of alpha 2-macroglobulin (A 2 M) are recommended. A substitution therapy can be oriented by the results of these coagulation parameters.

Aged↗
PubMed1981

[Experimental examination of skeletal muscle perfusion with stroma-free hemoglobin solution in ischemia].

An experimental study about post-ischemic perfusion of muscles with a new stroma-free hemoglobin solution is presented. Compared to other storage and perfusion methods the solution has several advantages: 1. Oxygenation and metabolism of the skeletal muscles are preserved. 2. Excellent wash-out effect. 3. The rheologic characteristics are better than those of whole blood. 4. No incompatibility. 5. No thrombogenetic effect. 6. The method is easy to manage. Our ultrastructural investigations show less damage of the muscle cells after a post-ischemic perfusion with oxygenated hemoglobin solution than after a post-ischemic physiological perfusion with whole blood.

Animals↗
PubMed1980

Determination of maximal ischemic tolerance of the human heart by ultrastructural recording of preischemic degree of myocardial hypertrophy and degeneration.

Three biopsies were taken transmurally in different time intervals (before and after ischemia and during the reperfusion phase) from 20 patients undergoing open-heart operation for acquired valvular heart disease, and the myocardial cylinders were examined with the electron microscope. They were scrutinized to see if there is a relationship between the degree of hypertrophy and degeneration before ischemia and the extent of ischemic damage after a certain ischemia period, and between the damage before ischemia and the postoperative outcome of the patients. Our results show that the ischemic changes are not dependent on the preischemic extent of hypertrophy and degeneration. It seems that they are mainly dependent on the duration of ischemia because the degree of ischemic damage increases with prolongation of the ischemia interval. However, a good correlation was found between the preischemic changes and the postoperative outcome. Especially the combination of marked hypertrophy and the appearance of degenerative signs in the biopsy taken before ischemia seems to predestine a bad postoperative course. Therefore, it can be concluded that the total damage to the myocardial cells, which results from the sum of previous damage (hypertrophy and degeneration) and ischemic alterations, is responsible for the postoperative outcome.

Cardiomegaly↗
PubMed1979

[Chest injuries (author's transl)].

The mortality rate of chest injuries sustained during work or in road accidents stands now at 15-20%. The considerable force of the impact in road accidents is, in 60-80% of the cases, responsible for chest injuries which involve not only the chest wall but also the lungs. The extent and course of the lung damage must be assessed by repeated X-ray examinations, blood gas analyses and clinical observations. The decision to intubate and apply artificial ventilation should be made at an early stage. Fracture of a single rib needs only pain killers. If a rib is broken in several places or if several ribs are fractured instability of the chest wall is apt to develop in 15-20% of the cases. It manifests itself in paradoxical breathing and ensuing increase in the dead space. These cases require prompt "internal pneumatic splinting" in the form of positive pressure respiration and intubation. In recent years surgical stabilization of the chest wall has regained favour. Plate osteosynthesis, screw-less rib plates, self-gripping steel plates and steel splints are being used (Brunner, Hofmeister, Koncz). Primary osteosynthetic stabilization of the chest wall is indicated only if artificial ventilation has proved inadequate and there are other reasons for performing a thoracotomy. In these circumstances surgical intervention ensures that prolonged artificial ventilation and its attendent risks and complications and the demands made on the nursing staff are reduced to a minimum.

Accidents, Traffic↗
PubMed1978

Surgical management of massive pulmonary embolism.

Between 1972 and 1976, 24 patients have been treated by open pulmonary embolectomy with the aid of cardiopulmonary bypass (CPB). In 17 (71 percent) acute pulmonary embolism occurred 3 to 60 days after a surgical procedure. The remaining seven (29 percent) patients had chronic medical diseases. The interval between clinical manifestation of acute pulmonary embolism and the performance of open embolectomy ranged from 8 to 36 hours. The definitive diagnosis in all patients was made by pulmonary arteriography. Candidates for pulmonary embolectomy were selected by assessment of hemodynamic stuides: shock, arterial Po2 less than 65 mm. Hg, acidosis, pulmonary artery pressure higher than 20 to 30 mm. Hg, and central venous pressure elevated (patients in Class III or IV according to the Greenfield classification). The definitive indication for embolectomy was occlusion of the main pulmonary artery of more than 50 percent as well as occlusion of the right or left pulmonary artery. Of the seven patients operated upon between 1973 and 1974, three (43 percent) died in the early postoperative period. Between 1975 and 1976 the operative mortality rate in 17 patients was 23 percent (four patients). Our results show that prompt diagnosis of acute massive pulmonary embolism and better selection of patients may improve significantly the survival rate after open pulmonary embolectomy with CPB.

Adult↗
PubMed1975

[Surgical treatment of cerebrovascular insufficiency due to extracranial obstruction of the carotid artery(author's transl)].

Reconstruction of the carotid artery was performed in 41 patients (between 1967 and 1974). All had had signs of cerebrovascular insufficiency. There was angiographic evidence of obliterating arteriosclerotic lesions in the carotid artery of 32 patients, carotid aneurysm in two, kinking of the internal carotid artery in four, and acute thromboses of the carotid artery in three. Early and late results indicate that best chances of success exist for stage II and III a cases. The high mortality rate in stages III b and IV (five of twelve patients) clearly shows that in these reconstruction of the carotid artery should be embarked on with caution, especially in the early stages.

Adult↗
PubMed1975

[Total electrode retraction (Twiddler syndrome) in infection of the pacemaker system].

We report upon a case of total retraction of an electrode (Twiddler syndrom) in an infected pacemaker battery. The silk-thread fixation was still fastened at the right place on the electrode; the tissue owing to the inflammation was no longer sufficient as a fixation point. The casues of this total retraction of the electrode are the following factors: the battery hat sufficient freedom of movement for rotation following exudation into the pacemaker cavity, the electrode was elastic and above all the pacemaker system was infected which could no longer guarantee a sufficient fixation of the electrode in the infected tissue. Attention is drawn to the necessity to remove an infected pacemaker system.

Aged↗
PubMed1975

[The effect of ischemic and cardioplegic heart standstill on the myocard metabolism in normal and less perfused heart (author's transl)].

The tolerance of ischemia in normal and less perfused myocard during an ischemic and cardioplegic heart standstill was investigated. A decrease of ATP and ADP and an increase of the lactate, pyruvate and AMP was established during an ischemia of 20 minutes. The less perfused hearts gave considerably worse results regarding the energy transformation than normal hearts. In less perfused hearts the energy reserve of myocardial metabolism showed a considerably better behaviour during a cardioplegic heart standstill of 45 minutes than an ischemic one of 20 minutes. During the recuperation period this trend was emphasised.

Adenosine Diphosphate↗
PubMedDate not supplied

Electron microscopic visible ischemic changes of the mitochondrial ATPases in human myocardial cells during extracorporal circulation.

During open heart surgery, needle biopsy material was obtained in four patients, and electron microscopic preparations of the mitochondrial ATPases (coupling factors 1) in human myocardial cells were performed. The pre-ischemic, normal structure of the mitochondrial ATPases and the changes which occur during the ischemic interval were described. An increase in the center-to-center space was shown in the post-ischemic phase. This result was discussed for the pathogenesis of subcellular injuries due to ischemia.

Adenosine Triphosphatases↗
PubMedDate not supplied

Direct detection of red blood cell fragments: a new flow cytometric method to evaluate hemolysis in blood pumps.

Pump induced hemolysis is presently evaluated by measuring plasma free hemoglobin (fHb). However, this method has disadvantages because quantification of fHb depends on hematocrit (HCT) and hemoglobin (Hb) levels. The aim of this work was to devise a hemoglobin independent method, capable of quantifying cell trauma directly by measuring the number of red blood cell (RBC) fragments. Whole blood flow cytometry was used to quantify circulating RBC fragments derived from a roller pump (Sarns, Inc. Model 2 M 6,002) and a centrifugal pump (Gyro C1E3, Kyocera Corp.). The pumps were tested in a mock circuit for 2 hr (5 L/min flow against 100 mm Hg pressure head). Red blood cell fragments were quantified by a phycoerythrin (PE) labeled glycophorin A antibody specific for erythrocytes. Red blood cell fragments were smaller than the intact RBC population and overlapped in size with the platelet population (based on forward- and side-light scattering measurements). For the roller pump, the values for RBC fragments increased from 1,090 +/- 260/microl at 0 min to 14,880 +/- 5,900/microl after 120 min. In contrast, using the centrifugal pump, there was little increase in RBC fragments (from 730 +/- 270/microl at 0 min to 1,400 +/- 840/microl after 120 min). Flow cytometry can be used for the rapid, sensitive, hemoglobin independent evaluation of pump induced RBC trauma.

Erythrocytes↗
PubMedDate not supplied

Cerebral microembolus generation in different extracorporeal circulation systems.

Microemboli generated during extracorporeal circulation (ECC) are likely to induce neurological sequelae. This study examines whether the choice of a distinct type of ECC can reduce intracerebral emboli counts. Middle cerebral artery blood flow during coronary artery bypass grafting was monitored continuously by transcranial Doppler ultrasound in 45 patients. The ECC systems used were a roller pump (n = 16), a centrifugal pump (n = 18) and a combination of centrifugal pump and heparin-coated ECC system (n = 11). Patients' characteristics as well as surgical and anesthesiological procedure did not differ between the groups. Total counts did not differ significantly between the three groups. Intraoperative events in individual patients may lead to massive embolus generation overcoming positive properties of a distinct ECC system.

Aged↗
PubMedDate not supplied

Correlation between mononuclear infiltration and changes in VASP phosphorylation patterns after heterotopic cardiac transplantation in the rat.

Chronic cardiac transplant vasculopathy still remains the major cause of late graft failure after the 1st postoperative year, with iNOS playing a central role in the progression of this disease. Since VASP, a recently identified microfilament-associated protein in smooth muscle cells, endothelial cells, and platelets, is phosphorylated by cyclic nucleotide dependent protein kinases, changing amounts of NO-producing mononuclear infiltration cells during cardiac rejection are supposed to change platelet VASP phosphorylation patterns. We investigated whether platelet VASP Ser(157) phosphorylation (VASP shift) after coronary passage of rat cardiac allografts correlates with graft infiltration. The Lew-F344 heterotopic rat cardiac transplantation model was used. Native hearts and grafts were harvested 3-150 days after transplantation and were used for Langendorff perfusion. The platelet VASP shift after native heart and graft perfusion was identified. Additional iNOS stimulation and iNOS inhibition were achieved pharmacologically. Immunohistology revealed graft mononuclear infiltration. Platelet VASP Ser(157) and Ser(239) phosphorylation significantly increased after coronary passage of native hearts and grafts (p < 0.01). Though platelet VASP Ser(157) phosphorylation failed to directly express graft infiltration, we showed a significant correlation between changes of platelet VASP shift and extent of grafts' mononuclear infiltration after competitive iNOS inhibition (p < 0.01). The platelet VASP shift is modified during coronary perfusion, and this modification correlates with mononuclear infiltration in the graft. This emphasizes the influence of mononuclear infiltration cells on microfilamental structures of the cytoskeleton in adjacent cells.

Animals↗