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Isolated Liver (isolated + liver)

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Medical Sciences75%

Terms modified by Isolated Liver

  • isolated liver transplantation
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    Selected Abstracts

    Gold-Tip Electrodes,A New "Deep Lesion" Technology for Catheter Ablation?

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2005
    In Vitro Comparison of a Gold Alloy Versus Platinum, Iridium Tip Electrode Ablation Catheter
    Radiofrequency (RF) catheter ablation is widely used to induce focal myocardial necrosis using the effect of resistive heating through high-frequency current delivery. It is current standard to limit the target tissue,electrode interface temperature to a maximum of 60,70°C to avoid char formation. Gold (Au) exhibits a thermal conductivity of nearly four times greater than platinum (Pt,Ir) (3.17 W/cm Kelvin vs 0.716 W/cm Kelvin), it was therefore hypothesized that RF ablation using a gold electrode would create broader and deeper lesions as a result of a better heat conduction from the tissue,electrode interface and additional cooling of the gold electrode by "heat loss" to the intracardiac blood. Both mechanisms would allow applying more RF power to the tissue before the electrode,tissue interface temperature limit is reached. To test this hypothesis, we performed in vitro isolated liver and pig heart investigations comparing lesion depths of a new Au-alloy-tip electrode to standard Pt,Ir electrode material. Mean lesion depth in liver tissue for Pt,Ir was 4.33 ± 0.45 mm (n = 60) whereas Au electrode was able to achieve significantly deeper lesions (5.86 ± 0.37 mm [n = 60; P < 0.001]). The mean power delivered using Pt,Ir was 6.95 ± 2.41 W whereas Au tip electrode delivered 9.64 ± 3.78 W indicating a statistically significant difference (P < 0.05). In vitro pig heart tissue Au ablation (n = 20) increased significantly the lesion depth (Au: 4.85 ± 1.01 mm, Pt,Ir: 2.96 ± 0.81 mm, n = 20; P < 0.001). Au tip electrode again applied significantly more power (P < 0.001). Gold-tip electrode catheters were able to induce deeper lesions using RF ablation in vitro as compared to Pt,Ir tip electrode material. In liver and in pig heart tissue, the increase in lesion depth was associated with a significant increase in the average power applied with the gold electrode at the same level of electrode,tissue temperature as compared to platinum material. [source]

    Liver glycogen metabolism during short-term insulin-induced hypoglycemia in fed rats

    CELL BIOCHEMISTRY AND FUNCTION, Issue 7 2008
    Simoni Obici
    Abstract The activities of glycogen phosphorylase and synthase during infusions of glucagon, isoproterenol, or cyanide in isolated liver of fed rats submitted to short-term insulin-induced hypoglycemia (IIH) was investigated. A condition of hyperinsulinemia/hypoglycemia was obtained with an intraperitoneal injection of regular insulin (1.0,U,kg,1). The control group received ip saline. The experiments were carried out 60,min after insulin (IIH group) or saline (COG group) injection. The rats were anesthetized and after laparotomy, blood was collected from the vena cava for glucose and insulin measurements. The liver was then infused with glucagon (1,nM), isoproterenol (2,µM), or cyanide (0.5,mM) during 20,min and a sample of the organ was collected for determination of the activities of glycogen phosphorylase and synthase 5,min after starting and 10,min after stopping the infusions. The infusions of cyanide, glucagons, and isoproterenol did not change the activities of glycogen synthase and glycogen phosphorylase. However, glycogen catabolism was decreased during the infusions of glucagon and isoproterenol in IIH rats, being more intense with isoproterenol (p,<,0.05), than glucagon. It was concluded that short-term IIH promoted changes in the liver responsiveness of glycogen degradation induced by glucagon and isoproterenol without a change in the activities of glycogen phosphorylase and synthase. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Isolated liver transplantation in infants with end-stage liver disease due to short bowel syndrome,

    LIVER TRANSPLANTATION, Issue 7 2006
    Jean F. Botha
    Infants with short bowel syndrome (SBS) and associated liver failure are often referred for combined liver/intestinal transplantation. We speculated that in some young children, nutritional autonomy would be possible with restoration of normal liver function. Features we believed to predict nutritional autonomy include history of at least 50% enteral tolerance, age less than 2 yr, and no underlying intestinal disease. This report documents our experience with liver transplantation alone in children with liver failure associated with SBS. Twenty-three children with SBS and end-stage liver disease, considered to have good prognostic features for eventual full enteral adaptation, underwent isolated liver transplantation. Median age was 11 months (range, 6.5 to 48 months). Median pretransplant weight was 7.4 kg (range, 5.2 to 15 kg). All had growth retardation and advanced liver disease. Bowel length ranged from 25 to 100 cm. Twenty-three children underwent 28 isolated liver transplants. There were 14 whole livers and 14 partial grafts (five living donors). Seventeen patients are alive at a median follow-up of 57 months (range, 6 to 121 months). Actuarial patient and graft survival rates at 1 yr are 82% and 75% and at 5 yr are 72% and 60%, respectively. Four deaths resulted from sepsis, all within 4 months of transplantation, and 1 death resulted from progressive liver failure. Two allografts developed chronic rejection; both children were successfully retransplanted with isolated livers. Of 17 surviving patients, three require supplemental intravenous support; the remaining 14 have achieved enteral autonomy, at a median of 3 months (range, 1 to 72 months) after transplantation. Linear growth is maintained and, in many, catch-up growth is evident. Median change in z score for height is 0.57 (range, ,4.47 to 2.68), and median change in z score for weight is 0.42 (range, ,1.65 to 3.05). In conclusion, Isolated liver transplantation in children with liver failure as a result of SBS, who have favorable prognostic features for full enteral adaptation, is feasible with satisfactory long-term survival. Liver Transpl 12:1062,1066, 2006. © 2006 AASLD. [source]

    NG -NITRO- l -ARGININE METHYL ESTER POTENTIATES ANAPHYLACTIC VENOCONSTRICTION IN RAT PERFUSED LIVERS

    CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2006
    Toshishige Shibamoto
    SUMMARY 1The effects of the nitric oxide (NO) synthase inhibitor NG -nitro- l -arginine methyl ester (l -NAME) on anaphylaxis-induced venoconstriction were examined in rat isolated livers perfused with blood-free solutions in order to clarify the role of NO in anaphylactic venoconstriction. 2Rats were sensitized with ovalbumin (1 mg) and, 2 weeks later, livers were excised and perfused portally in a recirculating manner at a constant flow with Krebs',Henseleit solution. The antigen (ovalbumin; 0.1 mg) was injected into the reservoir 10 min after pretreatment with l-NAME (100 mmol/L) or d -NAME (100 mmol/L) and changes in portal vein pressure (Ppv), hepatic vein pressure (Phv) and perfusate flow were monitored. In addition, concentrations of the stable metabolites of NO ( and ) were determined in the perfusate using an HPLC,Griess system. 3The antigen caused hepatic venoconstriction, as evidenced by an increase in Ppv from a mean (SEM) baseline value of 7.7 ± 0.1 cmH2O to a peak of 21.4 ± 1.1 cmH2O at 3 min in d -NAME-pretreated livers. Pretreatment with l-NAME augmented anaphylactic venoconstriction, as reflected by a higher Ppv (27.4 ± 0.8 cmH2O) after antigen than observed following d -NAME pretreatment. The addition of l -arginine, a precursor for the synthesis of NO, reversed the augmentation of anaphylactic venoconstricion by l -NAME. This suggests that hepatic anaphylaxis increased the production of NO, which consequently attenuated anaphylactic venoconstriction. However, perfusate NOx levels did not increase significantly after antigen in livers pretreated with either l -NAME or d -NAME. 4In conclusion, l -NAME potentiates rat anaphylactic hepatic venoconstriction, suggesting that NO contributes to the attenuation of the venoconstriction. However, this functional evidence was not accompanied by corresponding changes in perfusate NOx concentrations. [source]