The protective effects of prostaglandin E1 on sinusoidal endothelial cells in xenogeneic pig liver perfusion

The effects of prostaglandin E1 (PGE1) on hepatic sinusoidal endothelial cells (SEC) in the xenogeneic immunoreaction were investigated. Porcine livers were perfused with fresh human blood via the portal vein (PV) and the hepatic artery (HA) either with the administration of PGE1 (Group PG) or without PGE1 (Group C). The creatine kinase-BB component (CK-BB) in the perfusate was measured to assess SEC damage. SEC activation and complement activation were evaluated immunohistochemically by the expression of von Willebrand factor (vWF) and by the deposition of membrane attack complex (MAC), respectively. Xenoperfusion in Group C was discontinued between 4 and 6 hr due to the rapid elevation of HA pressures and the massive loss of perfusate. In Group PG, both PV and HA pressures were kept stable for up to 9 hr. In Group C, severe interlobular bleeding and diffuse extrasinusoidal hemorrhage were observed at 4 hr histologically, while in Group PG, the hepatic architecture was maintained without hemorrhage at 6 hr. MAC was markedly deposited on SEC and parenchymal cells at 3 hr in both groups. The amount of vWF, however, was expressed on SEC in large amounts at 1 hr in Group C, while small amounts were expressed at 1 hr in Group PG. In Group PG, CK-BB release was significantly lower than in Group C (P < 0.01). These results suggest that PGE1 suppressed SEC activation and protected the impairment of hepatic SEC during xenoperfusion without suppressing complement activation, resulting in the prolongation of xenogeneic liver perfusion.

Control of centrifugal blood pump based on the motor current

In this study, centrifugal pump performance was examined in a mock circulatory loop to derive an automatic pump rotational speed (rpm) control method. The pivot bearing supported sealless centrifugal pump was placed in the left ventricular apex to aorta bypass mode. The pneumatic pulsatile ventricle was used to simulate the natural ventricle. To simulate the suction effect in the ventricle, a collapsible rubber tube was placed in the inflow port of the centrifugal pump in series with the apex of the simulated ventricle. Experimentally, the centrifugal pump speed (rpm) was gradually increased to simulate the suction effect. The pump flow through the centrifugal pump measured by an electromagnetic flowmeter, the aortic pressure, and the motor current were continuously digitized at 100 Hz and stored in a personal computer. The analysis of the cross-spectral density between the pump flow and motor current waveforms revealed that 2 waveforms were highly correlated at the frequency range between 0 and 4 Hz, with the coherence and phase angles being close to 1.0 and 0 degree, respectively. The fast Fourier transform analysis of the motor current indicated that the second harmonic component of the motor current power density increased with the occurrence of the suction effect in the circuit. The ratio of the fundamental to the second harmonic component decreased less than 1.3 as the suction effect developed in the circuit. It is possible to detect and prevent the suction effect of the centrifugal blood pump in the natural ventricle through analysis of the motor current waveform.

Successful long-term xenoperfusion of the pig liver: continuous administration of prostaglandin E1 and insulin

For clinical utilization of extracorporeal liver perfusion as an artificial liver assist device, we examined the possibility of long-term xenoperfusion of the pig liver by the continuous administration of prostaglandin E1 (PGE1) and insulin. After a 3-hr perfusion period, pig livers that were xenoperfused with human blood exhibited a drastic decrease in the perfusate volume, a progressive elevation of the hepatic artery pressure, a gradual deterioration of bile production, and a marked increase in the release of creatine kinase-BB component. The continuous administration of PGE1 (25 microg/hr) and insulin (1 U/hr) significantly improved these derangements (P<0.05) and allowed stable perfusion for up to 9 hr. This manipulation also inhibited leukocyte aggregation in the graft, the characteristic perfusate hemolysis, and acceleration of ketogenesis. Histological examination revealed that the interlobular edema and hemorrhage, characteristics of tissue injuries in xenogeneic hyperacute rejection, were markedly alleviated in the PGE1 and insulin-treated group. This study clarifies the finding that the combined administration of PGE1 and insulin is effective for long-term xenogeneic extracorporeal liver perfusion, with the graft viability well maintained.

Reducing environment protects sinusoidal lymphocytes isolated from normal human liver from apoptosis

BACKGROUND/AIMS

We previously reported that the populations of lymphocytes and the expression of activated antigens in human sinusoidal mononuclear cells were different from those in peripheral blood mononuclear cells. Attempts to culture these cells for further study failed because they died rapidly under standard culture conditions in vitro after isolation from the liver. In this study, we evaluated the characteristics of cell death and the effects of various culture conditions on the viability of these cells.

METHODS

Sinusoidal mononuclear cells were isolated from University of Wisconsin solution that had been perfused through the portal veins of normal healthy human livers harvested for transplantation into living related recipients.

RESULTS

70% of sinusoidal mononuclear cells cultured in vitro were nonviable within 48 h after isolation, while only 10% of peripheral blood mononuclear cells died under the same conditions. Sinusoidal mononuclear cells showed DNA ladder formation of DNA on electrophoresis and characteristic morphological pattern on electron microscopic examination that suggested they had died in an apoptotic manner. The addition of human liver extracts or 2-mercaptoethanol and reduced glutathione to the cultures rescued the sinusoidal mononuclear cells from apoptosis. Furthermore, diamide, a sulfhydryl group specific oxidant, negated the effect of the liver extract.

CONCLUSION

In comparison with peripheral blood mononuclear cells, human sinusoidal mononuclear cells were more subject to death by apoptosis ex vivo, which was reversed by exogenous agents producing reducing conditions. These results suggested that hepatic sinusoidal mononuclear cells might express a different sensitivity to redox environment than peripheral blood mononuclear cells.

Apical canal sealing ability of calcium phosphate based cements

The apical canal sealing ability of newly developed calcium phosphate cement (TDM-C), an equimolar mixture of tetracalcium and dicalcium phosphate dihydrate kneaded with McIlvain's buffer solution containing sodium carboxymethyl cellulose, was evaluated in a relative comparison with several recognized available products. The latter included BONETRIX (alpha-tricalcium phosphate mixed with citric acid and tannic acid), ARS (alpha-tricalcium phosphate and hydroxyapatite mixed with polyacrylic acid), and zine oxide eugenol sealer (ZOE). Canals of forty extracted human maxillary central incisors were prepared to the file size #70, divided into four groups, and obturated with each of the four above materials. Setting of all sealers took place either in 30% bovine serum solution or in phosphate buffered saline solution. Teeth were then decalcified and cleared to measure linear penetration of India ink from the apex into the canal. Results were statistically analyzed by Student's t-test. Surfaces of all materials, after setting, were also observed by scanning electron microscopy (SEM). We found that TDM-C, BONETRIX, and ZOE all showed excellent apical sealing ability whereas ARS was less effective in this regard. SEM analysis revealed micropores on the surface of every apatitic product, but ZOE was free of such porosity. It was concluded that TDM-C and BONETRIX may prove clinically useful as root canal sealant materials.

Guidelines for donor selection and an overview of the donor operation in living related liver transplantation

Guidelines for donor selection and an overview of the donor operation are reported on the basis of our experience with 120 cases of living related liver transplantation (LRLT) in pediatric patients. Once the parents had clearly expressed their desire to serve as donors, tests were performed to functionally and anatomically screen the donor livers to determine whether or not the parents' general physical condition allowed them to serve as donors. We then evaluated which of the two parental candidates was more suitable as a donor. The wishes of the family as to which parent should serve as donor was considered secondary and taken into account only in a few cases in which certain functional and/or anatomical abnormalities were uncovered that made the prime candidate less suitable. For the 120 LRLTs, 135 candidates were evaluated as potential donors, 15 (11.1%) of whom were rejected for various reasons. The mean volume of blood loss during the donor operation decreased significantly from 489 g in the first 60 LRLTs to 390 g in the latter 60 LRLTs; this was accompanied by a significant decrease in the mean volume of autologous blood transfused from 449 g to 390 g. Mean cold ischemia time of the graft increased significantly from 71.4 to 128.0 min, while mean operation time conversely decreased from 6.7 to 6.2 h. Bile leakage from the cut surface of the remnant liver, which was the only post-operative surgical complication encountered, was noted in five cases. We conclude that donor candidates should be strictly selected according to basic guidelines, taking into account both the results of preoperative screening and the wishes of the family. With this accumuled experience, we have been able to simplify our LRLT operative procedure, resulting in decreases in blood loss volume, blood transfused, and operation time.

Evaluating the significance of HLA class II genotype matching in living-related liver transplantation

To evaluate the clinical significance of HLA class II matching in living-related liver transplantation, the genotypes of HLA class II including DPB1 were determined by the PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method and their matching was compared to the postoperative course. Conventional serotypes included 15.6% and 13.6% errors in DR and DQ, respectively. Among 42 consecutive cases that were followed up over 1 year after transplant, rejection occurred in seven cases. There was no correlation between the matching for each locus and the frequency of rejection episodes. In this study, rejection-free cases were investigated in terms of the potency of immunosuppressive therapy and graft function during 1 year after operation. The doses of tacrolimus in unmatched cases tended to be larger than those in matched cases for every locus except for DQA1. Its trough levels in matched cases were lower than those in unmatched cases, especially at 9-12 months after operation for DRB1 (p < 0.05). The termination of steroid administration tended to be postponed in unmatched cases for every locus. Serum levels of asparatan transaminase, alanine transaminase gamma-glutamyltranspeptidase (gamma-GTP) and total bilirubin were generally lower in matched cases than in unmatched ones for DRB1, DQB1 and DPB1, while in DQA1 the tendency was the opposite, especially total bilirubin and gamma-GTP, which were p < 0.02 and p < 0.05, respectively, at 6 months after operation. Investigation of subclinical immune responses other than rejection episodes showed that DRB1, DQB1 and DPB1 matching had a beneficial effect on graft function, while DQA1 matching seemed to have a varied effect.

Guidelines for donor selection and an overview of the donor operation in living related liver transplantation

Guidelines for donor selection and an overview of the donor operation are reported on the basis of our experience with 120 cases of living related liver transplantation (LRLT) in pediatric patients. Once the parents had clearly expressed their desire to serve as donors, tests were performed to functionally and anatomically screen the donor livers to determine whether or not the parents' general physical condition allowed them to serve as donors. We then evaluated which of the two parental candidates was more suitable as a donor. The wishes of the family as to which parent should serve as donor was considered secondary and taken into account only in a few cases in which certain functional and/or anatomical abnormalities were uncovered that made the prime candidate less suitable. For the 120 LRLTs, 135 candidates were evaluated as potential donors, 15 (11.1%) of whom were rejected for various reasons. The mean volume of blood loss during the donor operation decreased significantly from 489 g in the first 60 LRLTs to 390 g in the latter 60 LRLTs; this was accompanied by a significant decrease in the mean volume of autologous blood transfused from 449 g to 390 g. Mean cold ischemia time of the graft increased significantly from 71.4 to 128.0 min, while mean operation time conversely decreased from 6.7 to 6.2 h. Bile leakage from the cut surface of the remnant liver, which was the only post-operative surgical complication encountered, was noted in five cases. We conclude that donor candidates should be strictly selected according to basic guidelines, taking into account both the results of preoperative screening and the wishes of the family. With this accumuled experience, we have been able to simplify our LRLT operative procedure, resulting in decreases in blood loss volume, blood transfused, and operation time.

Medication of feedlot calves infected with Eimeria spp. by a combination of sulfamonomethoxine and ormetoprim

Feedlot calves naturally infected with Eimeria spp. were medicated by a combination of sulfamonomethoxine and ormetoprim (Ektecin). Calves, less than one year old and positive for coccidiosis, were administered with Ektecin (5, 10 and 20 ml/100 kg of body weight/day) and Daimeton (100% sulfamonomethoxine: 5 g/100 kg of body weight/day) for five days. No diarrhea were found on and after 3 days of medication in all the groups, and no oocysts were detected on and after day 5, 2, 1 or 3 from calves of the respective medicated groups. In samples from a group of calves administered with lowest dose of Ektecin, eimerian oocysts of 4 species were detected on day 0, and additionally 3 species (totally 7 species) were found on day 3 of medication.

Long-duration xenogeneic extracorporeal pig liver perfusion with human blood

Hepatic xenografts can tolerate hyperacute rejection owing to their lower susceptibility to humorally mediated injury. We investigated the possibility of long-duration xenoperfusion without immunologically controlling natural antibodies or complements. Pig livers were perfused for 9 h with human blood (Group 1) or pig blood (Group 2). Physiological conditioning and administration of prostaglandin E1 and insulin was characteristic of our system. The portal vein and hepatic artery pressure and bile production did not significantly differ between the two groups. Despite a gradual decrease throughout the perfusion, overall oxygen consumption was significantly higher in Group 1. Liver enzymes were released at higher levels in Group 1. Histological examination revealed intact hepatic architecture in Group 2, while in Group 1 interlobular morphology was severely damaged by endothelial disruption, although hepatic sinusoidal architecture was preserved. It is concluded that, despite biochemically and histologically confirmed tissue injury, graft viability was well-maintained in xenoperfusion even without immunological manipulations.

Inhibitory effect of plasma FKBP12 on immunosuppressive activity of FK506

To evaluate the roles of extracellular FKBP12, we examined the effect of extracellular FKBP12 on the immunosuppressive activity of FK506 in vitro and clinically. The ability of FK506 to suppress phytohemagglutinin-induced proliferative response of human peripheral blood mononuclear cells was inhibited in the presence of recombinant FKBP12 dose-dependently. We measured plasma levels of FKBP12 using a newly developed enzyme-linked immunosorbent assay system in 34 patients receiving FK506 after liver transplantation. In 7 patients with acute cellular rejection, plasma FKBP12 increased significantly at the onset of rejection compared with 1 week before onset (P < 0.05) and further increased to or remained at more than 250 ng/ml 1 week after onset. In 22 of 27 patients without acute cellular rejection, plasma FKBP12 was less than 70 ng/ml during the 4 weeks after transplantation. In the other 5 of 27 patients without acute cellular rejection, plasma FKBP12 exceeded 250 ng/ml. Rapid increase of plasma FKBP12 was observed in only one of these 5 patients, at the onset of high fever due to a liver abscess. There was no significant difference in whole blood trough levels of FK506 between the patients with or without acute cellular rejection. These results suggest that the rapid increase in plasma levels of FKBP12 may contribute to the occurrence and progress of acute cellular rejection probably by inhibiting the immunosuppressive activity of FK506.

Suppression of adult T cell leukemia-derived factor/human thioredoxin induction by FK506 and cyclosporin A: a new mechanism of immune modulation via redox control

Adult T cell leukemia-derived factor (ADF), which is identical to a disulfide reducing enzyme human thioredoxin (TRX), is produced and released by activated or virus-infected lymphocytes. Here we report that, in peripheral blood mononuclear cells (PBMC) stimulated with phytohemagglutinin (PHA), ADF/TRX mRNA was induced within 8 h after stimulation as detected by in situ hybridization study. To analyze the mechanism of ADF/TRX induction during T cell activation, the effects of immunosuppressants including FK506, rapamycin (Rap) and cyclosporin A (CsA) on ADF/TRX expression were investigated by immunoblot analysis. ADF/TRX induction in PBMC by PHA, Con A or OKT3 mAb was almost completely suppressed by FK506. Whereas CsA also inhibited ADF/TRX expression in OKT3 mAb-stimulated PBMC, Rap failed to affect it in spite of exhibiting growth inhibition. In addition, exogenous IL-2 could not increase ADF/TRX production in FK506-treated PBMC or in PHA blasts. These results indicate that ADF/TRX induction in T cell activation depends on calcineurin-dependent events in the early phase and that IL-2 production is not directly involved in ADF/TRX induction. Furthermore, when recombinant ADF (rADF) was added to a culture of PBMC 1 h before the addition of PHA and FK506, the action of FK506 was partially reversed as determined by [3H]thymidine incorporation and viable cell counts. These results suggest that ADF/TRX produced and released from PBMC may be a crucial event in lymphocyte activation, and that FK506 and CsA may exert the immune suppression partly through inhibiting the induction of the endogenous reducing factor ADF/TRX.

Biochemical and antigenical characterization of tannin-protein complex degrading enterobacteria isolated from koalas, Phascolarctos cinereus

Biochemical and antigenical characteristics of tannin-protein complex degrading enterobacteria (T-PCDE) isolated from Koalas, Phascolarctos cinereus, were investigated. T-PCDE had a specific profile of characteristics, and T-PCDE was distinguished from those of 12 type strains of Enterobacteriaceae used.

Changes in lymphocyte beta 2-adrenoceptors after hepatic resection

Hepatic resection promotes such a high degree of surgical stress that it induces deterioration of various vital functions, which may involve the breakdown of signal transduction systems. To investigate the influence of surgical stress on signal transduction, we studied ligand-receptor specific binding activity after hepatic resection, focusing on lymphocyte beta 2-adrenoceptors. The maximum binding capacity (Bmax) and the dissociation constant (KD) were determined by radioligand binding assay using (-)3H-CGP12177 as a ligand. In the hepatectomy group, Bmax significantly decreased from 1380 +/- 109 to 799 +/- 49 receptors/cell on postoperative day (POD) 3 and to 802 +/- 93 receptors/cell on POD 7 (P < 0.05). In the control group, however, it did not significantly change after the operation. No significant changes in KD were found in either of these groups. The Bmax alteration was not due to the redistribution of lymphocyte subsets or receptor down regulation, but to the decrease in the Bmax of the individual subset. The hepatectomy group was divided into two groups according to the postoperative arterial ketone body ratio (AKBR): Group A, AKBR maintained at 0.7 or more; and Group B, AKBR decreased to below 0.7. The Bmax decrease, a percentage of the preoperative value, of Group B was significantly smaller than that of Group A (48.4 +/- 3.9 and 72.3 +/- 7.3%, respectively, P < 0.05). These results suggest that intense surgical stress, produced by hepatic resection, may influence even ligand-receptor binding parameters, and the decrease in AKBR can indicate the magnitude of surgical stress.

The slow progression of hepatic fibrosis in intrahepatic cholestasis as compared with extrahepatic biliary atresia

It has been shown that the progression of hepatic fibrosis in intrahepatic cholestasis (IHC) is not so prominent as in extrahepatic biliary atresia (EHBA), and that the biosynthetic activity of collagen increases along with the fibrotic disease process. We conducted immunohistochemical and ultrastructural studies on the distribution of collagen types III and IV and of alpha-actinin in the smooth musculature in liver specimens obtained from 4 patients with IHC and 14 patients with EHBA in liver transplantation from living related donors (LRLT). A recently developed sandwich enzyme immunoassay (EIA) was used to determine serum concentrations of type IV collagen, laminin and prolyl 4-hydroxylase (PH) in the patients before and after LRLT. Pathological study showed that the excessive deposition of type IV collagen in the perisinusoidal walls resulted in a clearly developed basal membrane beneath the sinusoidal endothelial cells, so-called sinusoidal capillarization. In the fibrous septa of IHC, fibrogenesis was apparently lower than in EHBA, since collagen deposition and myofibroblast proliferation were not so prominent compared to EHBA. Serum type IV collagen, laminin and PH increased in IHC, although not so markedly as in EHBA, and returned to normal within 5 weeks after successful LRLT. In conclusion, it is suggested that an increased level of serum type IV collagen reflects the de novo synthesis of basal membrane components, and that the determination of their serum levels by EIA can be utilized for the differentiation of the specific fibrogenic activity in each disease, and for monitoring patients before and after liver transplantation.

Safety of the donor in living-related liver transplantation--an analysis of 100 parental donors

The safety and lack of undue operative stress on the donor are documented from an analysis of 100 parental donors, whose children (3 months to 17 years old), received LRLTx at our institution between June 1992 and May 1994. Survival rate of recipients was 86%. No primary nonfunctioning liver was observed. The donors were 56 mothers and 44 fathers. Their ages ranged from 19 to 51 years and their weight ranged from 44 to 80 kg. They received partial liver resections to harvest the grafts. With regard to the liver graft, the left lobe was used in 24 cases (group L) and the left lateral segment was used in 75 cases (group S). The right lobe was used in one case. In the two groups, blood losses were 242 +/- 5 (S) and 312 +/- 14 ml (L); operation times were 6.22 +/- 0.11 (S) and 7.15 +/- 0.21 hr (L), respectively; in both groups, the postoperative hospital stay was 11 days (S, L). No significant differences between the two groups were observed in peripheral RBC and WBC count or serum AST. An increase in total bilirubin was not observed. In the exceptional case using the right lobe, blood loss of 2300 ml necessitated a blood transfusion of 1000 ml, and the total bilirubin increased up to 4.0 mg/dl on the third postoperative day, which prolonged the postoperative hospital stay to 17 days. These results conclusively suggest that safety is guaranteed when the left lobe or the left lateral segment is used as the liver graft for LRLTx.

Analysis of functional abnormalities uncovered during preoperative evaluation of donor candidates for living-related liver transplantation

Functional abnormalities of the liver uncovered during preoperative routine evaluation were analyzed in 109 donor candidates for 100 cases of living-related liver transplantation (LRLT) performed during the period from June, 1990 to May, 1994 at the Second Department of Surgery, Kyoto University Hospital. High serum transaminase (GOT, GPT) levels were noted in 10 (9.2%) cases among 109 candidates, high alkaline phosphatase in 4 (3.7%), hyperbilirubinemia in 3 (2.8%), anemia in 3 and high choline esterase in 3 cases. Positive hepatitis C antibody (HCV) was also noted in 1 case. Fatty liver was detected in 10 (9.2%) cases, cholecystitis in 2 cases, 1 case each of cyst and calcification in the liver by diagnostic imaging (ultra sonograph and/or computed tomography). These abnormalities of the liver necessitated replacing the initial candidate with the other parent in 9 cases, including 1 case without any functional abnormality whose graft liver was too large to fit the recipient abdominal cavity. There were 14 cases of ABO blood type incompatible combination. Switching the initial candidate due to these abnormalities mentioned above resulted in incompatible combinations in 4 of these 14 cases. Although the advantages of the LRLT are the superior viability of the donor graft and the genetic histocompatibility between recipient and donor, to optimize the advantage of LRLT, all donor candidates should be strongly advised to make every effort preoperatively to improve their physical condition in preparation for the LRLT protocol, since many of these abnormalities are typically reversible.

Safety of the donor in living-related liver transplantation--an analysis of 100 parental donors

The safety and lack of undue operative stress on the donor are documented from an analysis of 100 parental donors, whose children (3 months to 17 years old), received LRLTx at our institution between June 1992 and May 1994. Survival rate of recipients was 86%. No primary nonfunctioning liver was observed. The donors were 56 mothers and 44 fathers. Their ages ranged from 19 to 51 years and their weight ranged from 44 to 80 kg. They received partial liver resections to harvest the grafts. With regard to the liver graft, the left lobe was used in 24 cases (group L) and the left lateral segment was used in 75 cases (group S). The right lobe was used in one case. In the two groups, blood losses were 242 +/- 5 (S) and 312 +/- 14 ml (L); operation times were 6.22 +/- 0.11 (S) and 7.15 +/- 0.21 hr (L), respectively; in both groups, the postoperative hospital stay was 11 days (S, L). No significant differences between the two groups were observed in peripheral RBC and WBC count or serum AST. An increase in total bilirubin was not observed. In the exceptional case using the right lobe, blood loss of 2300 ml necessitated a blood transfusion of 1000 ml, and the total bilirubin increased up to 4.0 mg/dl on the third postoperative day, which prolonged the postoperative hospital stay to 17 days. These results conclusively suggest that safety is guaranteed when the left lobe or the left lateral segment is used as the liver graft for LRLTx.