摘要:

This study was designed to clarify the mechanism of ischemia-reperfusion injury to skeletal muscle using long-acting polyoxyethylene-modified superoxide dismutase (SOD-POE) in rats. The gastrocnemius muscles of male Lews rats were investigated. Tissue levels of ATP decreased to 20% of nonischemic values after 3 h ischemia and returned to 94% after 1 h reperfusion. In contrast, they decreased to 3.5% after 4 h ischemia and remained at 20% after 1 h reperfusion. Although SOD-POE did not affect the decrease of ATP during ischemia, it improved significantly the recovery of ATP: 28%. Tissue levels of lipid peroxides (LPO) after 3 h ischemia and 1 h reperfusion did not change significantly compared with the nonischemic levels (0.71 ± 0.32 nmol/mg protein, mean ± SD). They showed no increase after 4 h ischemia, but increased explosively after 1 h reperfusion (2.15 ± 0.73 nmol/mg protein). SOD-POE did not affect LPO levels during ischemia but prevented the increase of LPO significantly after reperfusion (0.98 ± 0.25 nmol/mg protein). Xanthine oxidase activity did not increase after 3 h ischemia (22.3 ± 7.0 mU/g) compared with the nonischemic values (17.6 ± 10.0 mU/g). In contrast, it increased 2.5-fold after 4h ischemia (50.1 ± 13.7 mU/g) and remained at a significantly high level after 1 h reperfusion. SOD-POE did not affect xanthine oxidase activity during ischemia and reperfusion. These results suggest that lipid peroxidation by superoxide radicals produced by xanthine oxidase is a contributory factor to ischemia-reperfusion injury to skeletal muscle, and the clinical application of SOD-POE might be ex

ISSN:0014-312X    

DOI:10.1159/000129267

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effects of infusion of the oxygen radical generating system, hypoxanthine-xanthine oxidase, on pulmonary hemodynamics and plasma proteolytic systems, as the plasma kallikrein-kinin and fibrinolytic systems, were studied in pigs by infusion of xanthine oxidase into the pulmonary circulation. A marked pulmonary vasoconstriction and increase in vasculatur resistance with a maximum after 25 min was observed. The effects were attenuated by indomethacin, allopurinol and catalase. During the 130-min observation time there were no signs indicating activation of either the plasma kallikrein or the plasma fibrinolytic systems.

ISSN:0014-312X    

DOI:10.1159/000129268

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

We examined changes in the enzyme activities and metabolites related to hepatic fatty acid synthesis in fasted rats with sepsis produced by cecal ligation and puncture. Sepsis stimulated the in vivo incorporation of tritiated water into hepatic fatty acids and nonsaponifiable lipids. The activities of acetyl-CoA carboxylase, ATP-citrate lyase, and NADPH-generating enzymes (glucose-6-phosphate dehydrogenase and malic enzyme), the tissue levels of citrate and malonyl-CoA, and the dephosphorylation of carboxylase were increased in the livers of fasted septic rats compared with fasted sham-operated control rats. These results indicate that sepsis stimulated hepatic lipogenesis and sterologenesis in fasting rats. Furthermore, sepsis reduced the specific activity of hepatic mitochondrial carnitine palmitoyltransferase and raised that of glycerophos-phate acyltransferase, suggesting an increased diversion of cytosolic acyl-CoA towards esterification. These intrahepatic metabolic changes strongly suggest that sepsis causes anabolic action on hepatic lipid metabolism.

ISSN:0014-312X    

DOI:10.1159/000129269

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Atrial natriuretic factor (ANF) is secreted from atrial myocytes in response to increased atrial wall stress caused by increased transmural pressure. This study investigates whether the presence of an intact pericardium restricts the ANF secretory response to an increment in left atrial pressure caused by acute aortic constriction in anaesthetized open-chest pigs. The rise in ANF plasma concentration secondary to constriction was higher when the pericardium had been surgically opened than when it was left intact. Furthermore, an opened pericardium led to a larger increase during constriction in left atrial diameter as measured by sonomicrometry. The results suggest that the intact pericardium restricts the cardiac release of ANF secondary to aortic constriction, probably by restricting left atrial dilatation.

ISSN:0014-312X    

DOI:10.1159/000129270

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The influence of biosynthetic human growth hormone (b-hGH) on the mechanical strength development of skin incisional wounds in diabetic rats has been investigated after 4, 7 and 21 days of healing. Diabetes caused decreased mechanical strength of the wounds. After 21 days of healing, the diabetic animals treated with b-hGH from 7 days before wound infliction had an increased maximum load (14%) compared with the untreated diabetic animals. After 4 and 7 days of healing, no differences in the bîomechanical strength of diabetic wounds with and without b-hGH treatment were found. The diabetic animals receiving b-hGH showed a significant increase in body weight compared with the untreated diabetic animals. In the diabetic animals, the blood glucose concentration was increased by treatment with b-hGH. In conclusion, treatment with b-hGH from 7 days before operation can counteract the reduced mechanical strength of skin wounds in diabetic rats on day 21

ISSN:0014-312X    

DOI:10.1159/000129273

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Suture-holding capacity (breaking strength) of small bowel anastomoses made with interrupted or continuous sutures was assessed in two groups of rats. The tightness of the suture line was varied in a standardized manner in both groups. All types of anastomoses had similar strength immediately after surgery. After 72 h, suture-holding capacity had decreased by 50–55% (p 0.05) if sutures were loose. Changes in strength were similar regardless of whether interrupted or continuous sutures were used. Myeloperoxidase activity, reflecting tissue neutrophil accumulation, and hydroxyproline content were similar in all types of anastomoses after 72 h. Deterioration of early anastomotic strength is probably due to proteinase-mediated tissue degradation. It is speculated that tight sutures encourage proteolytic enzyme activity in the bowel wall by disturbing the local proteinase/proteinase inhibitor bala

ISSN:0014-312X    

DOI:10.1159/000129274

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Liver regeneration following transplantation in ‘small for size’ conditions is not fully understood. We therefore evaluated the regenerative response of transplanted partial liver grafts in outbred rats without the use of immunosuppression and compared it to liver regeneration following resection. The transplanted livers showed enhanced regeneration compared to controls. We suggest that this is caused by activation of the immune sys

ISSN:0014-312X    

DOI:10.1159/000129275

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

This study investigates the use of EuroCollins (EC) and University of Wisconsin (UW) solution, two major preservation fluids, for small bowel preservation. After in situ flushing, grafts were cold-stored at 4°C with either EC for 30 min (group 1a), 6 h (group 1b) and 12 h (group 1c) or with UW for 30 min (group 2a), 6 h (group 2b) and 12 h (group 2c). Using UW, cold ischemia was extended to up to 18 h (group 2d). As a control, small intestines were flushed and stored for the same time periods in cold saline (group 3a–c). Survival in group 1b was 66 % versus 100% in group 2b. After 12 h 80% survived in group 2c, but there were no survivors in group 1 c. After 18 h of cold storage, survival was only observed in group 2d (25%). Saline was ineffective after 6 h of preservation. Histology at the end of preservation revealed characteristic changes for EC (intracellular vacuoles) and UW (amorphic granules). We conclude that with UW small bowel can be preserved for up to 12

ISSN:0014-312X    

DOI:10.1159/000129276

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Forty-seven colorectal polyps of various histologic types were studied using retrospective flow cytometric (FCM) DNA analysis to determine the prevalence of aneuploid cell populations and whether they were associated with any particular histologic features. Overall, 6 of 47 polyps (12.8%) contained DNA aneuploid cells, comprising 4 adenomatous polyps, 1 of 12 with mild atypia (8.3 %), 2 of 19 with moderate atypia (10.5 %) and 1 of 4 with severe atypia (25.0%), and 2 of 4 polyps (50.0%) with histologic features of carcinoma in situ (CIS). The incidence of DNA aneuploid cells in CIS was significantly higher than that of all adenomatous polyps (p = 0.043). All of the 8 hyperplastic polyps were diploid. The detection of aneuploidy as a marker of increased risk for malignant transformation was possible even in colorectal adenomas measuring ≤ 10 mm. These results show that retrospective FCM analysis can detect DNA aneuploidy in adenomatous polyps and that DNA aneuploidy may occur before histologic evidence of invasive carcinom

ISSN:0014-312X    

DOI:10.1159/000129277

出版商:S. Karger AG    

年代:1993

数据来源: Karger