Involvement of endothelin in graft-versus-host disease after rat small bowel transplantation

Endothelin (ET-1) expression was evaluated by radioimmunoassay in both plasma and various tissue specimens serially obtained from LBN-F1 recipients of LEW heterotopic small bowel allografts. The recipients showed graft-versus-host disease (GVHD), which histologically became apparent on postoperative day (POD) 13. The ET-1 levels peaked on POD 9 in the kidney, lung, and host intestine at 51.0 ± 21.1, 90.9 ± 59.6, and 25.4 ± 11.8 pg/g wet, respectively, and peaked on POD 11 in the plasma at 7.7 ± 3.2 pg/ml; thereafter, they decreased to basal levels in both the plasma and tissue specimens on POD 13. An immunohistochemical study of these organs showed a corresponding increase in ET-1 staining in both the endothelial and epithelial cells on PODs 5 and 9, and a reduction in staining on POD 13. In conclusion, ET-1 was found to be increasingly released from the target cells of GVHD before any histological changes became apparent, thus suggesting the pathophysiological involvement of ET-1 in intestinal GVHD. Received: 11 June 1996 Received after revision: 3 September 1996 Accepted: 28 October 1996     

Adenovirus-mediated gene transfer using ex vivo perfusion of the heart graft

A replication-deficient adenovirus was used for ex vivo gene transfer into rat heart grafts under conditions simulating clinical transplantation. The adenoviral vector, AdHCMVsp1LacZ, containing an expression cassette of Escherichiae coli lacZ, was used to perfuse heart grafts during cold ischemia before transplantation. Heart grafts were perfused with University of Wisconsin (UW) solution containing either 0 pfu, 5×10¹⁰ pfu, or 1×10¹¹ pfu of viral vector, and were preserved for either 2 or 4 h and then transplanted into syngeneic recipients. The animals were killed at 1, 7, and 14 days after transplantation. The infection rate was assessed by histochemical staining for -galactosidase. Using polymerase chain reaction (PCR), viral DNA presence was confirmed in every graft perfused with viral vectors. The protein production from the transfected gene was confirmed by a functional protein assay. An efficient gene transfer was achieved with an infection rate of 1%–1.5% for all cardiac myocytes, as assessed by 5-bromo-4-chloro-indolyl--d-galactopyranoside (X-gal) staining. All studies were negative in the control grafts. Gene expression persisted for at least 10 days after transplantation. We thus conclude that an efficient adenovirus-mediated gene transfection and expression of gene products can be achieved in ex vivo perfusion of the heart graft during cold preservation.     

Effect of Routine Varicella Immunization on the Epidemiology and Immunogenicity of Varicella and Shingles

Varicella-zoster virus (VZV) causes varicella as a primary infection and remains latent in the ganglia until it becomes reactivated to cause herpes zoster. Individuals with varicella develop adaptive humoral and cell-mediated immunity. Compromised cell-mediated immunity is thought to contribute to the development of herpes zoster. Recent evidence suggests that changes in the epidemiology of varicella have affected the epidemiology of herpes zoster. The incidence of herpes zoster is higher in older adults; thus, the herpes zoster vaccine is recommended for older adults. However, the incidence of herpes zoster is expected to rise among younger individuals; hence, vaccination with the varicella vaccine should also be considered in younger adults. In order to determine the need for vaccination in different populations, it is important to establish methods to accurately assess the activity of cell-mediated immunity and humoral immunity.     

The use of stents for duct-to-duct anastomoses of biliary reconstruction in orthotopic liver transplantation

BACKGROUND/AIMS: Biliary anastomotic complications remain a major cause of morbidity in liver transplant recipients. The objective of this retrospective study is to reassess the use of anastomotic stents for biliary reconstruction while focusing on an end-to-end choledochocholedochostomy (EECC) in orthotopic liver transplantation (OLT). METHODOLOGY: EECC for the biliary reconstruction in OLT was performed in 115 patients. Sixty-three had their bile duct reconstructed over a T-tube stent (S group) while the remaining 52 patients underwent the same procedure without the stent (non-S group). The two groups were compared in terms of biliary complications and the conversion rate to a hepaticojejunostomy (HJS). RESULTS: Twenty-three biliary complications were observed in the OLT patients. In the S group, the incidence of a biliary leak was 12.7%, 8 of 63 patients in which 5 patients showed a bile leak when T tubes were removed. The rate of biliary stricture in the S group was 25.4%, or 16 patients. This stricture rate was not significantly different from the 13.5% rate observed in the non-S group (p=0.086). In the non-S group, 7 patients showed a biliary stricture. Four of 7 patients also developed a bile leak identified to be an anastomotic leak, which consequently resulted in HJS. A total of 6 patients, 5.2% of all OLT patients, underwent a subsequent revision of their primary anastomoses. The incidence of conversion from EECC to HJS in the non-S group, 57.1% was significantly higher than that in the S group, 12.5% (p=0.046). CONCLUSIONS: EECC (i.e. with or without a T-tube stent) is both a safe and effective technique for biliary reconstruction in OLT. However, the conversion rate from EECC to HJS in the non-S group was significantly higher than that in the S group. An indwelling T-tube stent is therefore considered to be useful for both achieving the lowest possible rate of severe anastomotic stricture and to prevent any subsequent intervention.     

Lipopolysaccharide-induced microglial activation induces learning and memory deficits without neuronal cell death in rats

We used lipopolysaccharide (LPS) to activate microglia that play an important role in the brain immune system. LPS injected into the rat hippocampus CA1 region activated microglial cells resulting in an increased production of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha in the hippocampus during the initial stage of treatment. Immunostaining for IL-1beta was increased at 6 hr after LPS injection. IL-1beta-immunopositive cells were co-localized with immunostaining for CD11b. Subacute treatment with LPS by the same route for 5 days caused long-term activation of microglia and induced learning and memory deficits in animals when examined with a step-through passive avoidance test, but histochemical analysis showed that neuronal cell death was not observed under these experimental conditions. The increased expression of the heme oxygenase-1 (HO-1) gene, an oxidative stress maker, was observed. However, the genetic expression of brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, decreased during the course of LPS treatment. We found decreases in [3H]MK801 binding in the hippocampus CA1 region by LPS-treatment for 5 days. The data shows that glutamatergic transmission was attenuated in the LPS-treated rats. These results suggest that long-term activation of microglia induced by LPS results in a decrease of glutamatergic transmission that leads to learning and memory deficits without neuronal cell death. The physiologic significance of these findings is discussed.     

Hydrodynamically stable adhesion of endothelial cells onto a polypropylene hollow fiber membrane by modification with adhesive protein

The effect on the adhesion of endothelial cells of immobilization of adhesion proteins onto a microporous polypropylene hollow fiber membrane for a conventional artificial lung was investigated with the aim of constructing a hybrid artificial lung bearing endothelial cells on the modified membrane. The membrane was modified by adsorption or covalent bonding of adhesion proteins of fibronectin, gelatin, or Pronectin. The density of adherent cells on the membrane modified by adsorption of or covalent bonding with fibronectin reached 1 × 10⁵ cells/cm² after 1 day of incubation, which corresponds to the confluent cell density in a conventional culture dish, while the cell densities on the membranes modifieds with gelatin and Pronectin were 1–5 × 10⁴ cells/cm² and 0.5–1 × 10⁴ cells/cm², respectively. The loading of hydrodynamic shear force (0.23N/m²) for 30min to the membranes bearing endothelial cells had little effect on the density of adhered cells. The membrane covalently bonded with fibronectin could well maintain a high cell density even after the loading of a higher shear force of 1.15N/m² for 180min, however, at this level of shear force 49% of adhered cells on the fibronectin-adsorbed membrane were lost after 30min. A partial cardiopulmonary bypass in rats employing the hybrid artificial lung model composed of a polypropylene hollow fiber membrane covalently bonded with fibronectin and endothelial cell adhesion showed the inhibition of tumor necrosis factor- release and an increase in IL-10 concentration in the circulating blood compared with that employing an artificial lung without cells. Long-term partial cardiopulmonary bypass employing the hybrid artificial lung model should be studied further.