摘要:

The bacteriological barrier function of the ileocecal valve (ICV) can be replaced according to the principle of the nipple-valve anastomosis. Since late complications due to technical measures for stabilizing the ileal nipple have been hitherto unknown, 12 adult beagle dogs were operated on by three technical modifications of a nipple-valve anastomosis and were followed up for 1 year: In three cases the ileal nipple was stabilized by longitudinal staples (NVA), in three cases an intestinal neosphincter (INS) was produced by healing of the muscular layers between the ileal nipple and colon, and in six cases an oral zone of stabilization, preserving an aboral valve zone (S-NVA) was constructed. Measures for valve function at the end of the study period were the weight course of the animals and the intestinal bacterial profile, considering morphological complications of the substituted valves. As reference the respective bacterial counts in ICV and end-to-end anastomosis (EEA) were used, which had been determined in the same animals in earlier experiments. Following an initial increase in weight the 3 animals with NVA and the three animals with INS continuously lost weight from the 4th postoperative month onward. The 6 animals with S-NVA, however, showed from the 4th postoperative month onward a significantly higher weight level (p < 0.05), which remained constant up to the end of the 1-year observation period. Because of a morphologically intact structure of the substituted valve a significantly (p < 0.05) better bacteriological clearance of the ileum was confirmed in these animals after 12 months when compared with the EEA group. In contrast, in the NVA and INS animals a severe bacterial overgrowth of the entire small intestine was observed. This was caused by an intestinal stagnation due to partial prolapse of the nipple in NVA and due to fibrotic stenosis in INS. The results of our study suggest that technical measures to relieve the tendency to devaginate are only successful, if they do not lead to obstruction of the orthograde intestinal passage in the long term. Thus, only the clinical introduction of the S-NVA model may be justified.

ISSN:0014-312X    

DOI:10.1159/000129510

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

In the present study polyglycolic acid (PGA) mesh was used for repair of fascial defects experimentally made in rats. In the experimental group fibroblasts were cultured on the mesh before implantation and in the control group the mesh alone was used. Rats were sacrificed 7, 14, 28 and 60 days after the implantation of the mesh. Tissues were examined microscopically and for hydroxyproline content. Microscopically good incorporation of the mesh was noted in both the control and experimental groups. However, it seems that in the experimental group earlier dissolution of the mesh occurred. The hydroxyproline content was higher in the experimental group after 7 (statistically not significant) and 14 days (p < 0.05) and in the control group after 28 (p < 0.025) and 60 days (p < 0.05). These results suggest that the use of PGA mesh with cultured fibroblasts might have a beneficial effect on wound healing.

ISSN:0014-312X    

DOI:10.1159/000129511

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Since intercellular adhesion molecule-1 (ICAM-1) has been reported to play a major role in reperfusion injury after ischemia, we estimated the effects of an anti-rat ICAM-1 monoclonal antibody (1A29) on hepatic ischemia-reperfusion injury in rats. Partial liver ischemia was achieved by clamping hepatic hilar vessels supplying the cephalad three lobes of the liver for 90 min. An intraportal injection of 1A29 was given 5 min after revascularization (n = 28), and saline was injected in control rats (n = 28). Changes in the proportion of liver necrosis, hepatic tissue blood flow, serum liver enzymes and liver neutrophil sequestration were analyzed at 6, 24, 48 and 72 h after revascularization. The intraportal injection of 1A29 significantly reduced the hepatocellular necrosis, restored the hepatic tissue blood flow at 24, 48 and 72 h of reperfusion (p < 0.05 or p < 0.01), and significantly suppressed the levels of serum liver enzymes at all time points during reperfusion (p < 0.01, respectively). The 1A29 treatment significantly reduced the number of neutrophils at the pericentral area, while those at the periportal area were similar in the two groups. The results suggested that ICAM-1 plays an important role in the development of hepatic ischemia-reperfusion injury, and that 1A29 reduced the injury possibly caused by cytotoxic inflammatory responses, based on neutrophil adherence to pericentral sinusoids.

ISSN:0014-312X    

DOI:10.1159/000129512

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

AUopurinol (AP) protects skeletal muscle function against ischaemia-induced injury, but the mechanism is not yet clear. As AP acts as a competitive xanthine oxidaxe inhibitor, both a reduction of oxygen-derived free radicals and an enhancement of purine resynthesis (salvage pathway) might be involved. We investigated the in vivo kinetics of high-energy phosphates in skeletal muscle after AP pretreatment using 31P-magnetic resonance spectroscopy during 2 h of ischaemia and 3 h of reperfusion in rat hindlimbs. Three animals (group A) were pre-treated with a total of 160 mg/kg AP i.p., 3 control animals (group B) received the same amount of 0.9% saline solution. ATP decreased to 18.6 ± 1.3% of the pre-ischaemic value in group A and to 17.3 ± 2.8% in group B after 2 h of ischaemia, and rose to only 47.7 ± 1.5 and 50.5 ± 1.8%, respectively, after 3 h of reperfusion. Phosphocreatine fell to 7.2 ± 2.9 and 7.6 ± 2.2% of pre-ischaemic values after 2 h of ischaemia and rose again to 36.5 ± 12.9 and 45.4 ± 20.4% after 3 h of reperfusion. Inorganic phosphate (Pi) increased 5-fold after 2 h of ischaemia, irrespective of the treatment. After 3 h of reperfusion, Pi was still 4 times the pre-ischaemic value. The kinetics of ATP, PCr, and Pi levels were not statistically different between the two groups. These results indicate that the ATP salvage pathway does not play an important role in AP-induced attenuation of ischaemia/reperfusion-induced muscle

ISSN:0014-312X    

DOI:10.1159/000129513

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

In order to elucidate the immunological characteristics of rat liver transplantation, graft-infiltrating cells (GIC) isolated from rat hepatic allografts were analyzed phenotypically and functionally. GIC from long-surviving recipients (Brown Norway livers into Lewis hosts) and acutely rejecting recipients (DA livers into Lewis hosts) were compared. The relative proportions of all T cells and activated T cells determined by flow cytometry were significantly higher in acutely rejecting Lewis recipients than in long-surviving recipients on day 6 after grafting. Phenotypic kinesis of GIC on days 6, 14, and 45 after transplantation from long-surviving Lewis hosts was analyzed. Each proportion of all T cells, OX8-positive cells (cytotoxic T and natural killer cells), and OX39-positive cells (IL-2 receptor), was greatest on day 6 and decreased by day 45. Cytotoxic activity of GIC toward donor lymphocytes on day 6 was greater in acutely rejecting versus long-surviving recipients. These results demonstrate that an immunosuppressive mechanism is already present on day 6 posttransplantation, and that infiltration or activation of cytotoxic T cells is inhibited in the long-surviving rat hepatic allografts.

ISSN:0014-312X    

DOI:10.1159/000129514

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Our previous study demonstrated that Lewis (LEW) rat recipients engrafted with Brown-Norway (BN) rat liver displayed a long-term graft survival and that phenotypic and functional analyses of graft-infiltrating cells on day 6 postgrafting showed a lower proportion and activity of cytotoxic cells in long-term surviving hosts than LEW recipients engrafted with DA rat liver which showed acute rejection on day 9 postgrafting. In order to assess the immunological mechanisms of unrespon-siveness, we analyzed the lymphocyte and serum from LEW recipients engrafted with BN liver. Spleen cells from tolerant LEW recipients on day 6 posttransplantation had no suppressor effect on the one-way mixed lymphocyte culture (MLC) reaction. On the other hand, when serum was added to MLC at a concentration of 6% of the total volume, it suppressed the mixed lymphocyte reaction (MLR) toward donor BN cells by 45.6%, but not toward third-party DA stimulator (-0.4%). Adoptive transfer of the serum from tolerant LEW hosts into the virgin secondary LEW hosts significantly prolonged the graft survival ofBN kidneys from 7.8 ± 0.2 to 14.7 ± 1.6 days (p < 0.01), but not of third party DA kidney graft (mean survival time = 9.5 ± 1.3 days). The in vitro study demonstrated that the suppressor factor in the serum inhibited the production of IL-2 as well as γ-IFN in MLR. The suppressor factor was absorbed by LEW cells stimulated with BN cells in vitro, indicating that this factor was directed against recognition sites on responder T lymphocytes. These results showed that an antigen-specific tolerogenic factor which recognized the idiotype of the donor was released into the circulation through the process of BN liver graft

ISSN:0014-312X    

DOI:10.1159/000129515

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

In order to understand the role of vasoactive peptides in fat embolism, arterial plasma atrial natriuretic peptide (ANP) and endothelin-1 concentrations were investigated in an experimental study. Nine anesthetized and mechanically ventilated pigs received an intracaval infusion of allogeneic bone marrow suspension at a dose of 100 mg/kg (fat embolism group); 9 control pigs received saline. The observation period was 5 h. In the fat embolism group, cardiac index and heart rate decreased within 30 min, whereas mean arterial pressure remained stationary. Pulmonary capillary wedge pressure rose transiently and central venous pressure rose slightly in time, while mean pulmonary arterial pressure, pulmonary vascular resistance and pulmonary shunt increased immediately and persistently after the bone marrow suspension infusion. Simultaneously, arterial oxygen tension and arterial hemoglobin oxygen saturation decreased markedly. Arterial plasma ANP and endothelin-1 concentrations remained stable in the fat embolism animals, whereas in the controls ANP and endothelin-1 levels decreased at 3 and 5 h. Arterial epinephrine concentrations were stable in animals receiving bone marrow suspension, while in the controls arterial epinephrine concentrations decreased towards the end of the experiment. Arterial norepinephrine concentrations remained unchanged in both groups. To conclude, impaired pulmonary function and consequent systemic hypoxemia distinguish the present fat embolism model. Unchanged arterial ANP and endothelin-1 concentrations in the fat embolism group suggest that these circulating vasoactive hormones have a minor impact on the pathogenesis of the current experimental fat embolism.

ISSN:0014-312X    

DOI:10.1159/000129516

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

This study aimed at evaluating the role of platelet-activating factor (PAF) on cardiovascular dysfunction in postischemic shock in pigs. Sixteen pigs were randomly allocated to two groups of eight each. Their aorta was clamped above the celiac axis for 45 min and then declamped. The animals were studied for 2 h after declamping. They were given a continuous infusion of Hartmann’s solution 6.75 ml/kg/h throughout the experiment. The experimental group was given a potent specific PAF receptor antagonist 15 min before reperfusion (BB-882 1 mg/kg bolus followed by continuous infusion of 1 mg/ kg/h till the end of the experiment). The control group was given vehicle instead. Reperfusion in the control group caused prolonged hypotension (mean arterial pressure (SEM): 29 (1) mm Hg, immediately after declamping, compared with 74 (3) at baseline), an increase in pulmonary vascular resistance (491.6 (51.5) dyn·s·cm–5, 2h after declamping, compared with 274.2 (19.4) dyn·s·cm–5 at baseline), a reduction in cardiac output (1.75 (0.15) liters/min, 2 h after declamping, compared with 2.8 (0.21) liters/min at baseline), hyperglycemia (13.7 (0.8) mmol/l, immediately after declamping, compared with 6.26 (0.6) mmol/l at baseline), and lactic acidemia (11.28 (0.5) mmol/l, immediately after declamping, compared with 4.55 (0.67) mmol/l at baseline). BB-882 did not improve any of these variables. PAF does not play a major role on cardiovascular dysfunction in postischemic shoc

ISSN:0014-312X    

DOI:10.1159/000129517

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Epidermal growth factor (EGF) is a potent growth factor with possible implications on the regulation of pancreatic secretion and duodenal absorption but also on pancreatic tumor growth. In the present study the growth effect on duodenal mucosa and pancreas by a 14-day continuous infusion of three different doses of EGF (4, 30 and 60 µg EGF/kg/24 h) was studied in rats. The EGF content in duodenal mucosa and pancreatic tissue was significantly increased by 30 and 60 µg/kg/24 h of EGF while plasma levels were only marginally increased. Neither duodenal mucosal nor pancreatic weights were changed but DNA content in both tissues was increased with the higher EGF doses. Long-term EGF infusion has moderate trophic effect on duodenal mucosa and the pancreas. There is a high tissue uptake of EGF, specially in duodenal mucosa. The hyperplasia seems to be related to tissue levels of EGF but not to plasma level

ISSN:0014-312X    

DOI:10.1159/000129518

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

To study consequences of cystic duct occlusion, 121 NMRI mice were operated: 40 had cystic duct ligature (L group), 41 had cystic duct ligature and evacuation of bile from the gallbladder (LE group), and 40 were sham-operated (S group). Ten mice from each group were sacrificed at 1 week, 1, 3 and 6 months, respectively. All but 2 mice showed signs of wellbeing during the observation time, and weight gain was the same in the three groups. Distended gallbladder occurred in 14 animals, 7 each in the L and the LE group, more frequent after 3 and 6 months. In the remainder mice the gallbladders were smaller than at the time of operation (p < 0.0001). Fibrosis and adhesions around the gallbladder were frequent in the L and the LE groups, and more pronounced in the latter (p = 0.0001). At microscopy there were signs of inflammation in the gallbladder wall in 16 cases in the L group, 28 in the LE group and 2 in the S group, and the degree of inflammation was more pronounced in the LE group than in the L group (p = 0.002). Eleven mice in the LE group had empyema, and slight intralumininal inflammation was more frequent in the LE group than in the L group (p < 0.0001). In conclusion, despite a high incidence of microscopic inflammation the study gave no indication that occlusion of the cystic duct did serious harm to the mice in this series.

ISSN:0014-312X    

DOI:10.1159/000129519

出版商:S. Karger AG    

年代:1997

数据来源: Karger