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

An allogenic transplantation of the total-pancreas with duodenum was carried out in the minipig model. The oral duodenum was closed blindly and the aboral part was led out as a stoma. The portal vein of the transplant was anastomosed end-to-side in the inferior vena cava and the celiac artery of the transplant in the distal aorta. Investigations for early diagnosis of rejection were carried out in this model parallelly respectively one by one. CT/MRT, selective angiography, laboratory chemical parameters were unsuitable for early detection. The pancreatic succus cytology and nuclear medical investigations show reproducible changes caused by rejection before the blood-sugar level was increased.

The influence of the stable prostacyclin-analogue Iloprost (Fa. Schering, Berlin) in the enzyme release from extracorporalic perfused kidneys was tested in an experimental investigation. The mechanic hypothermic perfusion was carried out on four different conditions. The estimation of specially cytosolic, lysosomal, and membrane-associated enzymes in the perfusat of the kidneys showed less activities in the Iloprost-protected kidneys. The results after the replantation of the kidneys support the interpretation of the enzyme determinations.

The early and the late motility of the donor organ was measured after 13 allogeneic and 4 autologous small bowel transplantations in mongrel dogs. The postoperative motility indices were increased in contrast to the preoperative values. The activity of allogeneic transplants were greater than these of autologous intestinal segments. The basal tonus of the intestinum obtains a higher level because inhibiting central nervous influences are omitted after the denervation of the mesenteric radix. The contraction frequency remained constant. Disturbances of the motility model with irregular contractions and decrease of the frequency become evident in case of ischemia and rejection of the transplant still before the clinical signs.

Endothelialization seems to be a possibility to reduce thrombogenicity of artificial vascular prostheses. We have been occupied to find an ideal coating for the cells. Substances of extracellular matrix (ECM) were used: human fibronectin (HFN), laminin, collagen type I + III + IV. We have compared the influence of these materials with regard to adherence, sheer stress resistance and growth of cultivated human vena saphena endothelial cells (SEC). There was not any statistically significant difference according to cell proliferation. During a cultivation period of 7 days SEC increased by population doubling number 5 corresponding to a population doubling time of 76 hours. PTFE prostheses were coated with the materials, seeded with SEC and exposed to sheer stress in a physiological perfusion unit. Adherent SEC were counted after 24 hours of perfusion. Counts were correlated to the number of seeded cells. After perfusion only 23 +/- 4%, resp. 25 +/- 6% of cells were counted on collagen I + IV + HFN and on collagen I + IV + laminin. We found better results on collagen I + III and on collagen I + III + HFN; there were adherent 55 +/- 5%, resp. 53 +/- 7% after perfusion. These results document that there is no difference for SEC cultivation on different native components of basal membrane, under sheer stress conditions there seems to be differences in cell adherence.

Perichondrium of human nasal, tracheal, costal and conchal cartilage was analysed by an immunohistological staining technique using monoclonal antibodies against different class II antigens. Our morphological study shows clearly the presence of class II antigens on the perichondrium of nasal, tracheal and conchal cartilage. Therefore the transplantation of cartilage allograft free of perichondrium may be preferred.

Good Laboratory Practice (GLP), Good Manufacturing Practice (GMP), and Good Clinical Practice (GCP) are the constituents of a new concept for quality assurance in pharmaceutical research. They are to establish standards for preclinical and experimental research in animals (GLP), for the manufacturing of drugs (GMP), and for trials on medical products in human beings (GCP), respectively. Each of the 3 entities is characterized by the same principles of control; these involve written instruction describing the general operations to be performed, the so called Standard Operating Procedures (SOP), and Quality Assurance Units being responsible for surveying the operations in accordance with the SOP, and ensuring that the generated data will satisfy the requirements for quality. As far as clinical trials are concerned, the SOP is represented by the study protocol and a Monitor provides for the surveying of the trial. GCP is further characterized by ethical principles, which aim primarily at protecting personal integrity and welfare of the trial subjects. The Declaration of Helsinki is the accepted basis for clinical trial ethics. Following the Declaration of Helsinki during the planning, conducting, surveying and evaluating of clinical trials provides for a degree of seriousness being the real hallmark of Good Clinical Practice.

Pressure and volume flow measurements were performed on a simple model of the tracheobronchial tree using a catheter-jet-ventilation apparatus. This type of respiration is particularly favourable in tracheo-bronchial surgery, i.e. resections and anastomosing, due to the experience of model as well as animal experiments. Under consideration of the particularities of catheter-jet-ventilation, this type of respiration provides excellent conditions for the surgeon. This is valid for the overview of the site of operation and possible manipulation within this region. This method of respiration is suggested as a reliable tool in the hands of less skilled anaesthetists, too, for its easy handling.

The ultrasonic treatment of vital tissue with therapeutically qualified ultrasonic intensity immediate before the cryosurgery leads to a significant enlargement of the plane and the depth of the cryodestruction. This knowledge should be used in the cryosurgical treatment of inoperable carcinomas with extensive tumor mass.

The manufacture of a skin button for use in chronic animal experiments is described, which is made of silicone rubber and intended to anchor the exit site of intravascular catheters. The button holds the catheter permanently in the skin and can also be used to anchor connections for occlusion cuffs and cables leading to implanted measuring elements.