摘要:

This work was undertaken to study the effects of tumor necrosis factor-α (TNF-α/cachectin) on developing granulation tissue in rats. Cylindrical hollow sponge implants were used as an inductive matrix for the growth of granulation tissue. In the two test groups the implants were injected daily for 4 days with a solution containing either 50 or 200 ng of TNF-α, while the implants of the control group were treated correspondingly with phosphate-buffered saline solution only. Analyses of granulation tissue and wound fluid in the sponge implants were carried out 7, 14 and 21 days after implantation. In histological specimens the ingrowth rate of granulation tissue into the sponge was significantly lower after 7 days in the group treated with 200 ng of TNF-α. No such an effect was observed after 14 or 21 days. After 7 days, the mean amounts of nucleic acids reflecting cellularity in the granulation tissue decreased dose-dependently, but nonsignificantly, in the groups treated with TNF-α. Simultaneously, the accumulation of collagen hydroxyproline of the sponge was significantly lower in the group treated with 200 ng of TNF-α than in the controls (–30%, one-way analysis of variance). This effect was not observed after 14 or 21 days. No significant differences were detected in the amounts of nitrogen, hexosamines and uronic acids between the groups, reflecting unchanged accumulation of glycosaminoglycans in the developing granulation tissue. No difference was detected in interleukin-1 activity of the wound fluid between the control and TNF-α-treated groups. These findings demonstrate that TNF-α treatment inhibits wound healing during its inflammatory phase by decreasing production of new granulation tissue. However, this effect disappears at later phases o

ISSN:0014-312X    

DOI:10.1159/000129163

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The orthotopic liver transplant model in rats has been very useful for immunological studies. However, differing opinions exist as to whether rearterialization of the graft is necessary for such experiments. Therefore, in this study we evaluted the short-term allograft function when rearterialized was compared to restored venous portal flow only and in situ hepatic artery ligation. The technique of orthotopic liver transplantation in the rat with and without rearterialization of the graft is described in detail. In addition, we evaluated the technical feasibility of sutured vascular anastomosis as compared to the traditional cuff technique. Urea synthesis rate was used as a sensitive marker of integrated liver function, including uptake, synthesis and excretion. Standard liver test of bilirubin, plasma aspergine aminotransferase and alanine aminotransferase were measured. We found no significant differences in the biochemical markers between allografts with portal venous flow only compared to the combination with arterial flow. Autopsy was performed after the biochemical studies at day 14. Histopathological analyses revealed no differences between the two groups of transplanted rats. The patency of sutured anastomoses was in our hands found to be superior to that of the cuff technique, with a success rate of more than 90% in rats with portal venous flow. This rat model in which vascular anastomosis is performed with a running suture technique and without rearterialization seems to be excellent for short-term studies of preservation and liver function after orthotopic liver transplantation.

ISSN:0014-312X    

DOI:10.1159/000129164

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Effects of treatment with prostaglandin E1 (PgE1) on normothermic liver ischemia were studied in male Lewis rats. Animals were subjected to 90 min of warm liver ischemia. Two groups of rats were constituted: group A (no treatment) and group B (PgE1 treatment). PgE1 (100 µg/kg) was given as a bolus 2 min before induction of ischemia and 2 min before the end of ischemia. Survival rates were assessed and, 6 h after the end of ischemia, serum transaminases, histology of the liver, Kupffer cell activity were evaluated. PgE1 treatment significantly improved survival rate (80%) in comparison with the nontreated group (40%). A significant reduction in transaminase levels was observed after PgE1 treatment. The extent of necrosis and congestion was improved by PgE1 treatment. Sheep red blood cell 51Cr liver uptake was deeply depressed 6 h after the end of ischemia in group A (6 ± 2.3 %/g tissue), and was significantly higher (p < 0.001) after PgE1 administration in group B (32.98 ± 11.7 %/g tissue). Our results demonstrate that PgE1 is able to protect the liver from ischemic insult. The mechanism by which prostaglandins exert this beneficial effect on normothermic liver ischemia may be related to their action on hepatic macrophag

ISSN:0014-312X    

DOI:10.1159/000129165

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

In a clinical setting, the effect of Eurocollins (EC) and University of Wisconsin solution (UW) on liver grafts were studied in the early reperfusion phase of liver transplantation. Blood samples were drawn before and after declamping of the portal vein in a group of 11 transplants with EC-perfused livers, and a group of 12 transplants with UW-perfused livers. Parenchymal damage was assessed by the LDH, AST, and ALT, and purine degradation by measuring the uric acid levels. Metabolic function was determined by the serum bile acids and the plasma amino acids, i.e. (valine + leucine + isoleucine)/(phenylalanine + tyrosine) ratio. Donor and pretransplant recipient parameters were almost identical. The cold ischemia time of both groups differed significantly. The results show the following: a significant difference between both the LDH and the uric acid levels in the two groups was revealed, with a smaller increase of the LDH levels and no increase of the uric acid levels in the UW group. Metabolic activity, as measured from the bile acids and the amino acid profile in the peripheral blood, was identical in both groups. We conclude that both EC-stored and UW-stored liver grafts show immediate metabolic function after reperfusion. The amount of metabolic function was equal in both groups, notwithstanding longer cold ischemia time in the UW group. In addition, more parenchymal damage occurred in the EC group.

ISSN:0014-312X    

DOI:10.1159/000129166

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

We have examined whether or not ciclosporin A (CsA) affects structure and function of the exocrine pancreas. Male Wistar rats were treated once a day for 7 days with intraperitoneal injections of vehicle or 5, 15, 30, or 50 mg/kg of CsA. Following the CsA treatment, incorporations of [3H]thymidine into DNA and [3H]orotic acid into RNA were found to be significantly reduced in a dose-dependent manner up to 30 and 15 mg/kg, respectively, at which doses the incorporations reached a plateau. The incorporation of [3H]-L-leucine into protein also decreased by 36% at the dose of 5 and by 53% at the dose of 50 mg/kg of CsA. The activities of amylase and lipase in the pancreas also decreased in the CsA-treated rats. Furthermore, a significant reduction in the specific binding of [3H]N-methylscopolamine to muscarinic receptor was observed following the administration of CsA. The Scatchard analysis for the [3H]N-methylscopolamine binding to the pancreatic membrane revealed a significant decrease in Bmax, but not in Kd values in the CsA-treated animals. In addition, it was found histologically that administration of CsA induced cellular atrophy, cytoplasmic vacuolization, and cellular necrosis in the exocrine pancreas. These results strongly suggest that prolonged treatment with CsA may induce the suppression of pancreatic exocrine functions by decreasing the contents of amylase and lipase as well as the number of muscarinic receptors, possibly by the inhibition of the syntheses of protein and DNA in the exocrine pancreas.

ISSN:0014-312X    

DOI:10.1159/000129167

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

It has previously been suggested that rejection after islet transplantation in mice is prevented by using a small amount of islet tissue from several donor animals of different strains. Furthermore, it has been suggested that ultraviolet light (UV) irradiation of islet grafts prevents rejection. We therefore studied whether islet allotransplantation in the rat could be improved by using islets from donor rats of several different strains or by using UV-irradiated islets. We found that Sprague-Dawley rats transplanted with 1,000 Wistar rat islets 2 days after streptozotocin (70 mg/kg, i.v.) remained normoglycemic for only 8 ± 1 days. The same poor result was obtained when the diabetic rats were transplanted with islets collected from donor rats of four different strains, also when only 100 islets from each donor rat were used in combination with short-term insulin treatment. In contrast, streptozotocin-diabetic Sprague-Dawley rats isotransplanted with either 1,000 islets or with 400 islets combined with a short-term insulin treatment remained normoglycemic for more than 3 months. Furthermore, rats allotransplanted with 400 UV-irradiated islets and also treated with ciclosporin remained normoglycemic for 30 ± 3 days, whereas those transplanted either with 400 UV-irradiated islets without ciclosporin treatment or with 400 nonirradiated islets with ciclosporin treatment did not reach normoglycemia. We conclude that, in rats, multistrain islet donation is not efficient and that UV irradiation of islets does not result in long-term benefit

ISSN:0014-312X    

DOI:10.1159/000129168

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Transferrin is reported to be a major lipopolysaccharide binding protein of human plasma, at least in vitro. By use of the limulus-amebocyte-lysate test the influence of transferrin on endotoxicity was studied. In the absence of any other protein human iron-free transferrin was able to strongly enhance endotoxicity in a concentration-dependent manner. Similar results were obtained when transferrin was added to primarily heat-inactivated plasma. Even in this assay the endotoxin recovery increased when transferrin was exogenously added. On the other hand, transferrin inhibited endotoxicity when inactivation of the plasma samples was performed after the addition of endotoxin and transferrin. These results lead to the conclusion that transferrin in fact interacts with lipopolysaccharide in a biologically important manner. In order to achieve neutralization of endotoxin, however, other plasma constituents are needed. The hypothetical function of transferrin is possibly a disaggregation of lipopolysaccharide micelles, following the interaction between the two molecules. The present data should justify further studies in order to clarify a possible benefit of the substitution of transferrin during gram-negative sepsis.

ISSN:0014-312X    

DOI:10.1159/000129169

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

With a 2.9-mM concentration of unlabelled bovine serum albumin (BSA), the FITC-albumin transport (2 mg included) across the omental monolayer (0.48 ± 0.16 mg/ml/30 min) was found to be significantly reduced as compared with the interstitial BSA concentration (290 µM) as it is the case, e.g., in peritonitis (0.79 ± 0.09 mg/ml/30 min). Adding 10 µg lipopolysaccharide (LPS)&slash;ml from Escherichia coli, serotype 0128:B12, we did not see any differences from the control. Cultured mesothelial cells took up double the amount of FITC-albumin (4.2 ± 0.13 µg/105 cells/30 min) and in the presence of LPS the uptake of FITC-albumin was reduced to half the control (2.15 ± 0.47 µg/105 cells/30 min). The results reveal the active participation of the mesothelium because high concentrations of BSA reduced exocytosis and stimulated endocytosis. Applying 10 µg/ml of LPS turned out to influence endocytosis and to reduce it at a high BSA conce

ISSN:0014-312X    

DOI:10.1159/000129170

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

In order to examine the postprandial blood concentrations of insulin-independent carbohydrates after gastric surgery oral galactose test (1.65 g/kg body weight in water, 33%, w/v) was performed in 55 symptomatic patients and in 5 healthy subjects. There were patients after total gastrectomy (TG) (n = 17), gastric resection with (GRS, n = 17) or without (GR; n = 12) selective vagotomy, and after proximal selective vagotomy (PSV, n = 9). The patients had immediately after drinking the test solution a 2- to 5-fold higher blood galactose concentration than the healthy subjects. The TG patients had the most rapid, the healthy subjects the slowest and the GR and GRS patients an intermediate rapid, immediate increase of blood galactose concentration. The TG patients showed a plateau 40–60 min and a decrease 60–90 min after the start of the test. The PSV patients showed a plateau 60–90 min after the commencement of the test. The GR and GRS patients and the healthy subjects had a continuous increase in blood galactose concentration during the whole test period, but the maximal point 90 min after the drinking of the solution was lower in the GRS than in the GR patients and lowest in the healthy subjects. The PSV patients had a lower blood galactose curve than the TG, GRS and GR patients but higher than the healthy subjects except the plateau 60–90 min postprandially. These results suggest that the postprandial blood concentration of insulin-independent carbohydrate, galactose, in symptomatic patients after gastric surgery relates with the type of operation and clearly deviates from healthy

ISSN:0014-312X    

DOI:10.1159/000129171

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Jejunal or colonic segments are currently used as esophageal substitutes after resection of intractable peptic stenoses. The present study was carried out in order to investigate the effects of the jejunal or colonic mucosa on antral gastrin (G) cells. Colonic or jejunal patches with intact vascular supply were sutured to the pyloric antrum or the higher portion of the gastric body in 40 rats. Ten further animals were used as controls. Three to 4 months after surgery, the serum gastrin levels were weekly determined in fasted (24 h) and freely fed rats using radioimmunoassay. The pyloric antrum was then removed, and the G cell density was assessed with an immunoperoxidase method. Transposal of the colonic mucosa to the antrum increased G cell density and basal serum gastrin levels, while grafting of the jejunal mucosa did not. G cell proliferation proved to be dependent on the topographic location of the colonic patch with respect to the pyloric antrum. Serum gastrin values in freely fed rats tended to be greater in the colon-to-antrum transposition group than in the other experimental groups, but the difference was not significant. In conclusion, variations between the properties of the jejunal and colonic mucosa would include their uneven effects on antral G cells.

ISSN:0014-312X    

DOI:10.1159/000129172

出版商:S. Karger AG    

年代:1991

数据来源: Karger