摘要:

We report the presence of platelet-activating factor (PAF-acether; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) in small-intestinal and colonic mucosa of neonatal rats. The PAF-acether content was higher in the colon than in the small intestine, and was lower in the small intestine of 30-day-old animals than in 14-day-old animals. We also report that cultured intestinal epithelial cells (INT 407) produce PAF-acether when stimulated with the calcium ionophore A23187, and that homogenized INT 407 cells can degrade PAF-acether with the formation of lysoPAF-acether. These findings suggest that intestinal epithelial cells are able to produce and metabolize PAF-acether, a potent mediator of inflammation. The authors propose that this might contribute to the pathophysiology of inflammatory bowel disease.

ISSN:0014-312X    

DOI:10.1159/000129224

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

In order to investigate the effects of the exogenously administered radical scavenger superoxide dismutase (SOD) on the orthotopic liver graft, livers from male Wistar rats were transplanted after subjection to 40 min of warm ischemia and 30 min of storage at 4 °C. SOD was given at the onset of ischemia and before reperfusion as a supplement (6,000 IU) to the washout solutions. 30,000 IU were infused into the recipient. SOD reduced tissue levels of thiobarbituric acid-reacting substances at the end of ischemia (737 vs. 956 nmol/g; p < 0.01) and 60 min after the onset of reperfusion (629 vs. 947 nmol/g; p < 0.001) and preserved total adenine nucleotides after reperfusion (11.69 vs. 10.40 µmol/g; p < 0.01). Survival 2 weeks after transplantation was 18% (2/11) in the SOD group versus 10% (1/10; nonsignificant) in untreated animals. It is concluded that SOD protects the ischemically altered liver from radical mediated peroxidation and preserves hepatic energy stores upon reperfusion. However, in our model no major improvement in organ viability could by achieve

ISSN:0014-312X    

DOI:10.1159/000129225

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Effects of 5 cold storage solution on hepatic high energy phosphate metabolism and metabolic function were examined using the isolated perfused rat liver. University of Wisconsin (UW), Euro-Collins (EC), and 2 cardioplegic solutions, Bretschneider’s HTK and St. Thomas Hospital solution, were studied for their protective capacity. Krebs-Henseleit bicarbonate buffer (KHB) was used to point out the effect of simple hypothermia. Liver ATP, total adenine nucleotides and energy charge losses were significantly lower during 21 h of storage in UW-preserved livers. Also, only UW-protected livers were able to complete regeneration of ATP and total adenine nucleotides after 1 h of reperfusion, whereas EC, HTK, St. Thomas and KHB stored livers only showed minimal regeneration. Concerning metabolic function, UW protected livers liberated significantly less LDH and sGOT as well in the 21-hour storage solution as into the perfusate under reperfusion conditions. This study demonstrates the capability of UW solution in liver preservation by its ability to maintain and restore high energy phosphate

ISSN:0014-312X    

DOI:10.1159/000129226

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Iron is suggested to play an important role in free radical generation during ischemia reperfusion. In the present study, the protective action of 4 iron-chelating agents, with different iron affinities, against reperfusion injury was examined in Langendorff-perfused hearts of neonatal rabbits. The chelators and their iron-binding constants (log Km) were as follows: catechol (43), mimosine (36), deferoxamine (31) and kojic acid (27). Following cardiac arrest, the hearts were subjected to global ischemia for 45 min at 37 °C, and then reperfused with modified Krebs-Henseleit solution for 30 min. In control, the left ventricular developed pressures (LVDP) after 30 min reperfusion recovered to 50.5 ± 3.0% (mean ± SEM; n = 5) of the preischemic level. In the hearts treated with catechol (30 µM), mimosine (30 µM) or deferoxamine (30 µM), the LVDP recovery was significantly improved up to 84.9 ± 1.3, 88.2 ± 2.9 or 87.4 ± 1.5%, respectively (p < 0.01 vs. control). Creatine phosphokinase (CPK) leakage during the initial 5 min of reperfusion was significantly decreased to about half of control in the hearts treated with catechol, mimosine, or deferoxamine. However, the treatment with kojic acid (30 µM) showed no improvement in the LVDP recovery and CPK leakage. Free radical generation was measured with an electron spin resonance using a spin-trapping agent, 5,5-dimethyl-pyroline-N-oxide (DMPO). The treatment with catechol, mimosine, or deferoxamine reduced the maximum intensity of DMPO-OH signal to about one third of control. However, the maximum intensity in the hearts treated with kojic acid showed a similar level to control. These results suggest that iron chelators have a protective effect on myocardial injury induced by ischemia reperfusion through inhibition of iron-catalyzed radical formation, and that the potentiality of iron chelators for myocardial protection is related to their iron

ISSN:0014-312X    

DOI:10.1159/000129227

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

An experimental model of clostridial gas gangrene was developed in rats and the therapeutic value of surgical debridement alone versus a combination of surgery and hyperbaric oxygen (HBO) was assessed. The infection was produced by an intramuscular injection of Clostridium perfringens microorganisms. The mortality of untreated rats was 100%. The mortality of the rats treated only with surgery was 37.5% compared to 12.5% when HBO was added to the treatment protocol (p < 0.01). In the group treated with HBO and surgery 82.5% of the animals healed completely and were able to walk normally, wheras the corresponding figure in the rats treated with surgery alone was 12.5% (p < 0.001). In the present experimental setting HBO treatment was an important therapeutic adjunct to surgery reducing both mortality and morbidity.

ISSN:0014-312X    

DOI:10.1159/000129228

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The relationship between superoxide production by liver macrophages and arterial ketone body ratio (AKBR), which reflects the oxidation-reduction state in the mitochondrial compartment of hepatocytes, was studied in rats with lethal and sublethal septicemia induced by intravenous injection of live Escherichia coli 014. In the sublethal model, AKBR decreased transiently (p < 0.01) and superoxide production by isolated liver macrophages increased significantly after opsonized zymosan (OZ) stimulation (p < 0.05). On the other hand, in the lethal model, AKBR decreased markedly (p < 0.01) to below 0.4 without recovery, and superoxide production was not activated by OZ stimulation. Thus, when AKBR decreases to an irreversible level, below about 0.4, superoxide production by liver macrophages is impaired, while as long as AKBR remains reversible, more than about 0.4, it is enhanced. It is suggested that superoxide production by the Kupffer cells is related to the intrahepatic oxidation-reduction state in the septic model.

ISSN:0014-312X    

DOI:10.1159/000129229

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

To clarify the effect of splenomegaly on portal hemodynamics in patients with portal hypertension and esophageal varices, manometric studies were carried out before and after splenectomy during an operation for esophageal varices. The 118 patients evaluated retrospectively had underlying liver cirrhosis (LC) (62), idiopathic portal hypertension (IPH) (42), and extrahepatic portal occlusion (EHO) (14). The weight of the spleen did not differ significantly among the three diagnostic groups: 640 ± 473.5 g for LC, 780 ± 414.6 g for IPH, and 683 ± 457.2 g for EHO. Before splenectomy, portal pressure was significantly elevated in the patients with EHO (410 ± 85.2 mm H2O) as compared to either the LC or IPH groups (348 ± 64.1 and 348 ± 73.5 mm H2O). Following splenectomy the reduction of portal pressure was significantly greater in the EHO group (29 ± 15.5 %) than in either the LC (18 ± 17.4%) or IPH (19 ± 17.0%) groups. Each group was subdivided according to severity of splenomegaly: marked (spleen weight ≧ 500 g) or slight (spleen weight < 500 g). Patients with LC and marked splenomegaly showed a reduction in liver function parameters as shown by the prolongation of indocyanine retention rate at 15 min as compared to those with slight splenomegaly. Though it is not statistically significant, the average portal pressure tended to be higher among those with marked splenomegaly. Except for the patients with LC, the reduction of portal pressure following splenectomy in those with marked enlargement was significantly large as compared to those patients with IPH and EHO and only slight splenomegaly (22.0 ± 14.7 vs. 11.6 ± 20.2% and 37.5 ± 14.1 vs. 19.5 ± 11.1%). These observations suggest that in EHO the effect of inflow portal hypertension contributes significantly to the severity of splenomegaly, while in LC the progression of disease may influence the extent o

ISSN:0014-312X    

DOI:10.1159/000129230

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Nitinol® is an equiatomic alloy of nickel and titanium which has been attracting increasing interest in the field of biomedical engineering. To quantify toxicity as a preliminary evaluation of biocompatibility, inhibition of mitosis in human fibroblasts in tissue cultures exposed to test materials is an accepted screening method, although a dose-effect relationship had never been investigated. In this experiment, the effect of an increasing dose exposure to Nitinol, nickel or titanium on human fibroblasts in cell cultures was tested in subgroups in comparison with a control group. The results showed that nickel induces a significant (p ≤ 0.05) inhibition of mitosis in human fibroblasts, whereas no significant effects of this kind were found for titanium or Nitinol. According to the results of these studies, Nitinol is to be considered in this respect bio-compatible and comparable to titanium, which would seem to justify application as a surgical impla

ISSN:0014-312X    

DOI:10.1159/000129231

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0014-312X    

DOI:10.1159/000129232

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0014-312X    

DOI:10.1159/000129233

出版商:S. Karger AG    

年代:1992

数据来源: Karger