摘要:

In the present study, attempts are made to improve posttransplant survival of intraportally transplanted hepatocytes in a syngeneic hepatocyte transplantation (HTX) model. Engrafted hepatocytes were detected and quantified after pre-transplant labeling with 5’-bromo-deoxy-uridine. In order to enhance the survival percentage, three mechanisms that possibly influence cell survival were manipulated: (1) administration of MatrigelTM (extracellular-matrix components, Matrigel Basement Membrane Complex, Micronic BV, Lelystad, The Netherlands) in order to improve the environmental conditions of the transplanted hepatocytes; (2) immunosuppression of the recipients by 5 Gy total body irradiation and cyclosporin-A administration (25 mg/kg, 3 × weekly), and (3) Kupffer cell depletion by injection of dichloromethylene-diphosphonate-filled liposomes. The results were analyzed in relation to HTX without treatment. Cell survival was –14% (10 days after HTX), and the transplanted hepatocytes were distributed equally throughout the various recipient liver lobes. However, no increase was attained by Matrigel coadministration, immunosuppression, or Kupffer cell deple

ISSN:0014-312X    

DOI:10.1159/000129552

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The aim of the present study is to investigate the impact of bile duct reconstruction by a splint technique, a method which has not been sufficiently researched in animals after liver transplantation. Three experimental groups were set up: I = control, sham operation; II = bile duct reconstruction; III = orthotopic rat liver transplantation (ORLT). After bile duct reconstruction, serum levels of ASAT and ALAT in group II revealed a peak on the first postoperative day. The transplanted animals (group III) showed a second peak in liver enzyme levels on the fifth postoperative day; it was significantly higher than in group II. Serum bilirubin was more elevated in the transplant group, with a peak on day 7. Morphological investigations at the end of surgery revealed only intralobular necrosis and reactive changes in the liver capsule (group II); after transplantation (group III), there was also interstitial and intracellular edema, fatty degeneration and disintegration of the sinusoidal lining. One month later, necrosis, bile duct proliferation, cholestasis, cholangitis and vascular alterations were found in groups II and III. Furthermore, an increased rate of hepatocellular and bile duct proliferation was observed. These findings are partly due to the bile duct reconstruction. We recommend that a bile duct reconstruction control group should be included in ORLT experiments.

ISSN:0014-312X    

DOI:10.1159/000129553

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Exposure to high-concentration oxygen (O2) increases lipid peroxidation of the cellular membrane, leading to tissue injury which may involve hepatic ischemia-reperfusion (I/R) injury. We examined the effects of inhaling high-concentration O2 on hepatic I/R injury with allopurinol, which is a xanthine oxidase inhibitor. Partial hepatic ischemia was performed in rats with or without allopurinol under 21 or 100% O2 inhalation. Levels of lipid peroxide, serum liver enzymes, and hepatocellular oxidative stress in the 100% O2 group were significantly higher than in the 21% O2. Administration of allopurinol significantly inhibited those changes in the 100% O2 group. Severe degeneration of mitochondria were noted in the 100% O2 group, but appeared to be reduced by allopurinol. Results suggest that inhalation of high-concentration O2 during liver surgery may increase lipid peroxidation and exacerbate hepatic I/R injury, but those changes may be prevented by allopurinol.

ISSN:0014-312X    

DOI:10.1159/000129554

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

To clarify the action of dibutyryl cyclic adenosine monophosphate (DBcAMP) on reperfused ischemic muscle, experiments were conducted using the hindlimbs of 18 male Lewis rats. At the midportion of the thigh all tissues except for the femoral artery and vein were transected, and a route for continuous intravenous infusion was secured in a contralateral limb vein. After inducing total ischemia by clamping the femoral artery and vein with a vascular clamp for 4 h, the limb was reperfused for 1 h. Blood flow was then compared using the hydrogen gas clearance method in a group in which DBcAMP 10 mg was continuously infused from a vein in the contralateral hindlimb from 1 h prior to the induction of ischemia to 1 h after the completion of ischemia (DBcAMP group), a group in which saline was infused in the same manner (control group), and a group which was subjected to biopsy alone (biopsy group). The percent change in blood flow was significantly higher in the DBcAMP group than in the control group at 15 and 30 min after the release of the clamp. Adenosine triphosphate (ATP), phosphocreatine (PCr), and lipid peroxide (LPO) were measured in tissue samples obtained 1 h after reperfusion. Serum LPO was measured in blood samples collected at the same time. ATP values were higher in the DBcAMP group than in the control group. PCr was significantly higher in the DBcAMP group than in the control group. LPO levels in skeletal muscle tissue did not differ significantly between the DBcAMP and control groups. In contrast, serum LPO levels were significantly lower in the DBcAMP group than the control group. On morphologic analysis the control and DBcAMP groups showed normal vascular endothelial cells and absence of the ‘no-reflow’ phenomenon. These data confirm that in this reperfusion model the administration of DBcAMP enhances the viability of skeletal muscle cells. Moreover, mediated by an effect on vascular endothelial cells this agent is thought to be of help in mitigating the vascular endothelial cell injury occurring in acute ischemic injury. DBcAMP may be a useful agent in mitigating skeletal muscle ischemia-reperfusion inj

ISSN:0014-312X    

DOI:10.1159/000129555

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Epidermal growth factor (EGF) is known to exert a mitogenic effect in different tissues, including the digestive tract. The aim of the present study was to evaluate whether long-term infusion of EGF causes trophic effects in the gastrointestinal tract of female mice. The animals were infused subcutaneously in the neck with human recombinant EGF in a dose of 10 µg/kg/h (1.6 nmol/kg/h) using an osmotic minipump for 1, 3 and 7 days, respectively. Tritiated thymidine was continuously infused intraperitoneally during the same period, except in the 7-day group, where it was infused during the last 3 days. The mucosal thickness was measured microscopically. As a measurement of DNA synthesis, the amount of thymidine retained in the mucosa was registered using a scintillation counter. After 1 day of EGF infusion, the mucosal thickness was increased in the antrum and, after 3 days, in the fundus. In the proximal duodenum, an increased depth of the crypts was seen after 1 day, followed by increased villi height after 3 and 7 days; in the distal duodenum, EGF evoked increased villi height after 3 and 7 days. The height of villi was increased after 7 days in the jejunum and ileum in the EGF-treated animals. The tritium incorporation was increased in the fundus of the stomach and the proximal duodenum in the EGF-treated animals after 3 days, whereas no significant increase in tritiated thymidine incorporation could be detected in the EGF-treated animals after 1 and 7 days compared to the controls. In conclusion, continuous infusion of EGF evoked increased mucosal thickness in the small intestine, while the trophic effects were only of a short duration in the stomach and absent in the colon

ISSN:0014-312X    

DOI:10.1159/000129556

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Background: Transplantation of vascularized knee joints has become technically feasible, but graft rejection as well as failures of the vascular anastomoses remain critical hazards. We therefore tested the potential of repetitive non-invasive duplex sonography to detect changes of the arterial blood flow following canine knee joint transplantation. Methods: Four transplantations and, as controls, 4 replantations of intact canine knee joints were performed. The follow-up was 6 months. During this period, repetitive duplex sonography measurements as well as tests of knee joint function were performed. Six months postoperatively, angiographies were performed and all joints were explanted for histological investigation. Results: The luminal diameters of the implanted popliteal artery remained constant in the transplanted animals (preop. 2.6 ± 0.2 mm, 6 months postop. 2.7 ± 0.2 mm) but decreased in the autografted controls (preop. 2.9 ± 0.3 mm, postop. 2.0 ± 0.3 mm). The time-averaged velocity of the popliteal artery blood flow decreased in both groups 1 month postoperatively. Subsequently, blood flow velocity recovered in transplanted animals but remained low in replanted controls. Significant arterial wall thickening was also detected in transplanted animals as compared to controls. Six months postoperatively, hypervascularization of transplanted joints was confirmed by angiography and thickening of the arterial wall by histology. Furthermore, histology identified mild to chronic allograft rejection in all transplanted joints in spite of controlled cyclosporin A trough level immunosuppression. Conclusions: Chronic rejection of transplanted vascularized knee joints appears to be associated with vessel wall thickening and hypervascularization rather than with vascular rarefaction (picture of the ‘arbre mort’) that is characteristic of the rejection of most parenchymatous organs. Duplex sonography appears to be sensitive in detecting the corresponding changes of blood

ISSN:0014-312X    

DOI:10.1159/000129557

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

67 patients with operable colorectal adenocarcinomas were divided into two groups based on criteria referring to DNA flow-cytometric models and the histopathological type and stage of intraoperatively harvested tumor samples: low-aggressive tumor group and highly aggressive tumor group. Two kinds of immunological markers were investigated: humoral (carcinoembryonic antigen and α-fetoprotein serum levels were measured by ELISA) and cellular (blood lymphocyte counts of the following subpopulations: CD3+, CD4+, CD8+/ CDllb+, CD19+, CD16+/CD56+, HLA-DR+/CD3+, measured by means of flow cytometry). All assays were similarly performed before and 2, 4, 6 and 8 weeks after tumor exeresis. Results seem to reveal a relationship between patients without immunological recovering and a bad postoperative clinical evolution of the highly aggressive colorectal malignant tumors. The significance of multiway immune monitoring of colorectal cancer is discussed

ISSN:0014-312X    

DOI:10.1159/000129558

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Suture implantation of viable exfoliated tumour cells may be responsible for local recurrence of colorectal cancer. Using a colon cancer cell line, we obtained a suture implantation without intraperitoneal metastasis in about 80% of the control animals, when sacrificed on the 2nd postoperative week. The cytotoxic efficacy of povidone-iodine (PVP-I) was tested in vivo by a rat model with viable intracaecal tumour cells, and in vitro by trypan blue exclusion and the MTT assay. In vivo PVP-I at 5 % significantly reduced the incidence of tumour growth, while the product at 2.5% had a significant effect in only the monofilament polypropylene group. In an in vitro toxicity study, PVP-I higher than 0.16% was effective at killing almost all tumour cells. PVP-I had effective cytotoxicity in vivo and in vitro, being less cytotoxic in vivo than in vitro.

ISSN:0014-312X    

DOI:10.1159/000129559

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The computer-assisted-localizer (CAL) achieves a direct linkage between preoperative radiological images and individual intraoperative anatomical findings. Experiences with our system demonstrate that CAL improves the intraoperative orientation and facilitates the neurosurgical procedure. The system described here consists of a mechanical articulated robot arm with six degrees of freedom and a three-dimensional image processor. After calibration, the displayed image dynamically pointed out the exact intraoperative localization in three perpendicular sectional views. Meanwhile, CAL was successfully used in 73 selected microneurosurgical procedures.

ISSN:0014-312X    

DOI:10.1159/000129560

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:0014-312X    

DOI:10.1159/000129561

出版商:S. Karger AG    

年代:1997

数据来源: Karger