Zeitschrift fur experimentelle Chirurgie, Transplantation, und kunstliche Organe : Organ der Sektion Experimentelle Chirurgie der Gesellschaft fur Chirurgie der DDR最新文献

In patients with a funnel chest, light-microscopic studies of their rib cartilage showed vessels in all slices of the cartilage. In all analysed stages of life there is a constant number of vessels per unit area; even in not deformed parts of the cartilage. Furthermore, the number of the chondrocytes strongly increases within the single chondrons with rising age in an extraordinary way.

The systolic, diastolic, and the mean arterial systemic blood pressure decreased after thoracotomy (by -12%). The systolic, diastolic, and the mean pulmonary arterial pressure showed an immediate decrease (by 25%). The central venous pressure was not changed. The cardiac output (HMV) and the stroke volume could not be measured before the thoracotomy. However, the HMV (+17%), the HMV-index (+30%), and the stroke volume (+60%) increased from the 10th to the 30th min after the thoracotomy. The heart rate decreased continuously (by -19%). The maximum rate of pressure rise (dp/dtmax) increased primarily insignificantly and decreased afterwards (by -10%). The quotient dp/dt/p decreased immediately (by -10%). All measures were carried out until the 30th min after thoracotomy.

After ligation of the mesenteric arteries an intestinal ischaemia was obtained. Endotoxin was measured from the peritoneal cavity, the portal und the peripheral blood. The limulus test for Endotoxin was used after phenol-water-extraction of the plasma. Microbiological investigations were done simultaneously. The endotoxin concentrations correlated to the clinical state of gram negative sepsis.

The qualification of tantalum wire as suture material was tested by means of physical and histological investigations. Starting-point were the physiochemical and biological attributes and its hitherto existing employment in the medicine. Indication and recommendations for handling the material were found out.

Unlabelled: The changes in the exocrine pancreas were investigated after ligature of the excretory duct in 51 Wistar rats. A qualitative microdetermination of the epithelial cells was carried out in the originated ductulus-like structures.

Conclusions: The acinic epithelial cells grow atrophically first of all and become necrotic in the end. A dedifferentiated acinic cellular atrophy with metamorphosis to a ductulus-like cell type could not be observed. Proliferative and preproliferative events occur in the duct epithelial cells. Cystic ductulus-like structures originated from this. These fill out the former acinic areas by immature, few differentiated, pluripotent epithelial cells that look similar to embryonal pancreatic cells.

Aside from the medical requirements a material has to fulfill to qualify as biocompatible, for the bioengineer, who is involved in the design, construction and fabrication of prosthetic devices, the mechanical, physical and chemical properties of the material as well as its possible manufacturing procedures and, last but not least, its biostability are of the same importance. In the very aggressive biological environment, the material should behave inertly, showing no surface erosions, molecular chain disruptions, uptake of low molecular weight biological materials, local chemical imbalances, tendency to calcification or negative changes of mechanical properties. With regard to this aspect, different polyurethanes have been evaluated in-vitro and in-vivo as basic materials and already fabricated devices (blood pumps and heart valves). The comparison of the results stresses the necessity of further efforts to achieve a standardized test protocol for the prove of the biostability of polymers, containing appropriate, well-defined in-vitro and in-vivo test methods to establish the necessary data basa for the materials' clinical approval.

Specific pediatric surgical problems, specially the hemisplenectomy and the partial liver resection in newborns and small children, offer a new indication for the laser beam. Special morphologic characteristics, like small organs and small vessels diameter, make the laser an useful procedure in children. With help of a histochemical technic could be shown a defined necrosis area - in dependence of the laser dose - in liver, spleen and kidney of rabbits under standard laser photocoagulation. Five days after the partial organ resection one could observe a well defined vital border, and after one week an invasive growing fibrotic tissue into the necrosis area, which would form the new capsula. No cases of infection or bleeding were present (84 partial organ resections). Using known doses one can exactly calculate the area of necrosis and evaporation.

A cage for total separation of feces and urine in the awake rat is presented. Construction and function are described in detail. Two important indications (investigation of the urinary enzyme activity, and determination of the endogenous creatinine clearance) are denominated.

Intestinal haemodynamics was examined invasively in 30 mongrel dogs. Beside registration of blood pressure values of the blood flow were evaluated especially. Measured flow values in the three main intestinal vessels - Truncus coeliacus, A. mesenterica superior and A. mesenterica inferior - were compared to aortal flow. Thereby the sum of intestinal arteries values was equal to intrarenal aortal flow. Two thirds of aortal flow may be expected in the portal vein. These relations make in possible to get informations about physiological intestinal circulation from single values without measurement of all intestinal vessels.

The antioxidative potential (AP) of blood plasma was defined for its O2-.-trapping capacity. The superoxide radicals were generated in a photochemical system and detected by luminol chemiluminescence. During the preparation phase of experimental liver transplantation on mini-pig the AP of peripheral blood increased twice. There is a 20-fold increase of AP one hour after the blood recirculation in transplant. An antioxidative defence of organ with ascorbic acid during the cold preservation period removed these increase. The possible mechanisms of the observed phenomena and the information significance of the AP measurement in blood plasma are discussed.