Novel magnetic rings for rapid vascular reconstruction in canine liver transplantation model

OBJECTIVE

Magnetic rings were used for rapid vascular reconstruction in a canine liver transplantation model.

MATERIALS AND METHODS

Thirty-two adult mongrel dogs weighing 13 to 16 kg were randomly selected as donors or recipients of transplantations. The recipients were randomly divided into two groups: group A (n = 10) had magnetic rings used for vascular reconstruction without venovenous bypass; group B (n = 6) had vascular reconstruction performed by continuous suturing with splenojugular venovenous bypass.

RESULTS

In group A, the entire operative period was 3.24 +/- 0.49 hours, the durations of clamping the portal vein and the infrahepatic vena cava of the recipient were 5.89 +/- 2.27 minutes and 3.89 +/- 0.73 minutes, respectively. In group B, the entire operative period was 4.12 +/- 0.51 hours with the duration of clamping portal vein and infrahepatic vena cava, 28.33 +/- 6.04 minutes and 12.16 +/- 3.72 minutes (P < .01 vs group A). In group A, mean arterial pressure dropped during the anhepatic phase but recovered quickly after reperfusion. The fluid infusion was about 730.56 +/- 50.56 mL in the group A and a pressor agent was unnecessary. In group B, blood pressure dropped during the anhepatic phase and slowly recovered. The fluid infusion was about 2241.67 +/- 390.78 mL and a pressor agent was used to maintain the blood pressure of the recipient. No twist or thrombus was discovered in the anastomoses group A and the endothelium at the site of anastomosis was entire. In group B, errhysis was common in the anastomotic stomas. Nine of 10 dogs in group A survived more than 3 days, the longest being 8 days, whereas four of the six dogs in group B survived less than 3 days.

CONCLUSION

The results showed that the anhepatic time was significantly shortened (about 5.89 +/- 2.27 minutes) in group A compared with group B and venovenous bypass was unnecessary. Magnetic rings could be used for rapid vascular reconstruction in canine liver transplantation model. The long-term results of this procedure should be clarified before it is applied in clinical practice in the future.

Conjugation metabolism of acetaminophen and bilirubin in extrahepatic tissues of rats

An anhepatic rat model was used to explore the extrahepatic conjugating metabolism of acetaminophen and serum bilirubin. The recovery of glucuronide- and sulfate-acetaminophen was 47.5% in normal control and 13.4% in model rats in the urine collected for 6 h after administration of acetaminophen 20 mg kg(-1). Following the increase of acetaminophen dose to 150 mg kg(-1), the recovery of urinary glucuronide-acetaminophen increased by 53.9% in normal control; but it decreased by 36.4% in model rats. In contrast to normal control, the pretreatment with phenobarbital did not affect acetaminophen and its metabolite levels in plasma and urine in model rats. After the establishment of anhepatic model the serum direct bilirubin rose dramatically. Urinary bilirubin test was positive in model rats, but not in normal control. No changes were observed in serum total bilirubin and ratio of direct/total bilirubin after the pretreatment with ranitidine or phenobarbital 50 mg kg (-1), i.p. for 5 days in model rats. The results indicate that the glucuronide- and sulfate-acetaminophen formed in the extrahepatic tissues of model rats is 28.2% of normal control, serum free bilirubin can be transformed into conjugated bilirubin in extrahepatic tissues, and the regulation mechanism of phase II conjugating enzymes is different between the hepatic and extrahepatic tissues.

[Postliposuction histologic alteration of adipose tissue in mini-pig models]

OBJECTIVE

To study the postliposuction histologic alterations of adipose tissue in Mini-pigs.

METHODS

Five Wuzhishan adult Mini-pigs were suctioned with syringe-assisted liposuction using a suction needle of 2 mm in diameter. The subcutaneous adipose tissues on both operated and controlled non-operated areas were collected from one week to eight months after operation and all samples were measured and observed macroscopically and microscopically.

RESULTS

The thickness of subcutaneous adipose tissues at the operated sites is thinner than the controlled sites. There was no significant difference in adipocyte morphology between the two kinds of samples. The structure of fat tissue recovered normally during 6-8 months after liposuction.

CONCLUSION

Liposuction is an effective operation to eliminate the subcutaneous adipose tissue and the structure of subcutaneous adipose tissue is completely normal in 6-8 months after the operation.