摘要:

Earlier we reported a positive effect of platelet-derived growth factor (PDGF-BB) on rat wound healing while corresponding doses of PDGF-AA were not as effective. The present work was undertaken to study the effects of the heterodimeric form of PDGF (PDGF-AB) on wound healing in rats. Subcutaneously implanted hollow cylindrical cellulose sponges served as an inductive matrix for the granulation tissue. Fifty microliters of solutions containing 0, 5, 50 or 500 ng of PDGF-AB heterodimer were injected daily into the sponges. The analyses of the granulation tissue in the sponge cylinders were carried out 7 days after implantation. Injections of 500 ng of PDGF-AB stimulated significantly the accumulation of collagen and proteins, indicated by the elevated hydroxyproline and nitrogen content of the sponge (+51%, p < 0.01 and +48%, p < 0.001 respectively). Similarly, the amounts of DNA, RNA, hexosamines and uronic acids were significantly higher, reflecting a PDGF-AB-induced increase in the cellularity and glycosaminoglycans. Analyses of wound fluid showed a marked decrease in the number of polymorphonuclear leukocytes in response to PDGF-AB treatment. Injections of a lower dose, 50 ng, of PDGF-AB increased significantly the mean amounts of nitrogen, RNA and uronic acids but no significant changes were observed in other parameters. The lowest dose of PDGF-AB, 5 ng daily, induced no essential effect. In vitro PDGF-AB increased the number of rat granulation tissue-derived fibroblasts and collagen accumulation per culture dish at concentrations of 10 and 30 ng/ml. To conclude, PDGF-AB accelerates dose-dependently granulation tissue formation in experimental wounds. Correspondingly, PDGF-AB stimulates the proliferation of granulation tissue-derived fibroblasts in culture.

ISSN:0014-312X    

DOI:10.1159/000129345

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Fibrin glue was prepared from citrated plasma of human donors by means of ethanol. The outcome was a fibrinogen concentrate with a mean concentration of 43 mg/ml. The fibrinogen was converted to fibrin by the addition of 0.3 part of thrombin solution, 150 NIH U/ml, containing 100 mM calcium chloride. In a rat model full-thickness skin grafts were sealed with the glue, and the adhesive strength was measured at different fibrin concentrations, and after a variable reaction time, and compared to commercial fibrin glue (Tisseel®). The strength of ethanol-prepared glue was directly proportional to the fibrin concentration, and increased rapidly within the first minutes of the reaction time. The strength of the commercial glue could be obtained with autologous fibrin glue at the same fibrin concentration

ISSN:0014-312X    

DOI:10.1159/000129346

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The purpose of this experimental study was to analyze the effect of different doses of atropine and bilateral transthoracic truncal vagotomy on pancreatic secretion. We chose the dog as our experimental model and used the modified Thomas method to obtain gastric juice, removing the gastric acid with a gastric cannula. An additional duodenal cannula was used for the selective intubation of the greater pancreatic duct in order to obtain pure pancreatic juice. To stimulate pancreatic secretion the pancreas was stimulated with intravenous secretin at a constant dose and intraduodenal tryptophan at gradually increasing doses. The juice was collected at 10-min intervals and volume, output of bicarbonate and protein were determined. The results obtained show that low doses of atropine (0.65, 1.25 and 5 µg/kg/h) strengthen the suppressive effect of truncal vagotomy on the hydrobicarbonate secretion. Greatest suppression was found in the highest dosage of atropine in response to the intraduodenal tryptophane at gradually increasing doses. The above results suggest the possible existence of local enteropancreatic cholinergic reflexes that are readily suppressed by atropine and vagotomy. Suppression is not global though, since there is no significant reduction in the pancreatic protein secretion, which shows a dosage-effect curve in response to the gradually increasing doses of intraduodenal tryptophan released by the action of endogenous cholecystokinin. Our hypothesis is that there exists a nonvagal enteropancreatic cholinergic reflex

ISSN:0014-312X    

DOI:10.1159/000129347

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The aim of parenteral nutrition in tumour patients is to offer an alternative nutritional support to the patient without accelerating the growth of the tumour. For this purpose we fed a total of 100 rats, divided into five groups of 20 animals each (10 with and 10 without tumours), for a total period of 15 days with various nutritional regimes. Group 1 received glucose, group 2 long-chain triglycerides, group 3 medium-chain triglycerides (MCT), group 4 ω-3 fatty acids, and group 5 an oral diet. On the 10th day the Yoshida sarcoma in its ascites form was implanted into the tumour-bearing rats. In animals receiving MCT or ω-3 fatty acids tumour growth was considerably smaller than in the other groups (group 1 vs. groups 3 and 4; p 0.05). We think that modulation of the immune system by feeding with MCT or ω-3 fatty acids was responsible for the reduced tumour growth in relation to the other groups. The extrapolation of these results to the clinical situation, however, may not be possi

ISSN:0014-312X    

DOI:10.1159/000129348

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Absorbable, nonwoven patches made from polyhydroxybutyrate (PHB) were implanted as transannular patches into the right ventricular outflow tract and pulmonary artery in 13 weanling sheep, the test group. Six sheep, in which a transannular Dacron patch was implanted, served as control group. The test and the control patches were harvested 3-24 months later. The results were documented macroscopically, by histological examination, and by scanning electron microscopy. The 6-keto-PGF1α activity was measured in the regenerated tissue and compared with that in the native pulmonary artery. No aneurysms were noted. Regeneration of a neointima and a neomedia, comparable to native arterial tissue, was observed in the test group. In the control group, a neointimal layer was present but no neomedia comparable to native arterial tissue. Scanning electron microscopy disclosed differences in the endothelial structure between the test and control groups. 6-keto-PGF1α activity was present in both the test and control groups. It is concluded that absorbable, nonwoven patches of PHB can be used as a scaffold for tissue regeneration in low-pressure systems. The regenerated vessel had structural and biochemical qualities in common with the native pulmonary arter

ISSN:0014-312X    

DOI:10.1159/000129349

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The relation between the level of cellular adenine nucleotides and graft viability after cold preservation and warm ischemia was studied by using a rat small-bowel transplantation model. The rat jejunum was preserved in lactated Ringer’s solution at 4°C for 120 min, and was then transplanted syngeneically under warm ischemia after between 60 and 180 min. The recovery levels of ATP and the energy charge at 30 min after reperfusion in the viable graft were significantly higher than those in the nonviable graft. None of the grafts were viable when the recovery level of ATP at 30 min after reperfusion was less than 2.8 µmol/g dry weight. These results suggest that the recovery level of ATP at 30 min after reperfusion is a reliable parameter for graft viability in small-bowel transplantat

ISSN:0014-312X    

DOI:10.1159/000129350

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

A novel device was constructed and used to bypass a ruptured aortic aneurysm internally in vitro. Three human aortas each containing an abdominal aneurysm were used for the production of transparent silicons rubber replicas. A pulsatile flow within the range of physiological parameters was employed. The aortic aneurysms were ruptured iatrogenically. After positioning the device in the aneurysm, complete control of fluid leakage through the ruptures was achieved. Normal flow through aortic abdominal branches and distal to the aneuryms was maintained.

ISSN:0014-312X    

DOI:10.1159/000129351

出版商:S. Karger AG    

年代:1994

数据来源: Karger

ISSN:0014-312X    

DOI:10.1159/000129352

出版商:S. Karger AG    

年代:1994

数据来源: Karger