Adenosine A2a Receptor Stimulation Attenuates Ischemia-Reperfusion Injury and Improves Survival in A Porcine Model of DCD Liver Transplantation.

Orthotopic liver transplantation (OLT) using allografts from donation after circulatory death (DCD) is potentially associated with compromised clinical outcomes due to ischemia-reperfusion injury (IRI)-induced organ damage and graft-related complications. The aim of this study was to provide in vivo data on the effects of adenosine A2a receptor stimulation in a clinically relevant large animal model of DCD liver transplantation. Cardiac arrest was induced in German Landrace pigs (n = 10; 20-25 kg). After 30 min of warm ischemia, the donor liver was retrieved following a cold flush with 3 L of histidine-tryptophan-ketoglutarate-HTK solution. Animals of the treatment group (n = 5/group) received a standard dose of the selective adenosine receptor agonist CGS 21680 added to the cold flush. All grafts were stored for 4.5 h at 4 °C in HTK-solution before OLT. Hepatocellular injury, apoptosis, protein kinase A-PKA activity, graft microcirculation, liver function, and animal survival were assessed. Compared to untreated livers, adenosine A2a receptor stimulation resulted in improved tissue microcirculation (103% ± 5% vs. 38% ± 4% compared to baseline; p < 0.05), accelerated functional recovery of the graft (indocyanine green-plasma disappearance rate (ICG-PDR) of 75% ± 18% vs. 40% ± 30% after 3 h), increased PKA activity ratio (56% ± 3% vs. 32% ± 3%; p < 0.001 after 1 h), and consequently reduced tissue necrosis and apoptosis. The potent protective effects were clinically manifested in significantly improved survival in the treatment group after 72 h (100% vs. 40%; p = 0.04). The ex vivo administration of adenosine A2a receptor agonist during the back-table flush mitigates IRI-mediated tissue damage and improves functional graft recovery and survival in a large animal model of DCD liver transplantation.

Role of preferential cyclooxygenase-2 inhibition by meloxicam in ischemia/reperfusion injury of the rat liver.

BACKGROUND: Ischemia/reperfusion injury (IRI) is one of the major clinical problems in liver and transplant surgery. Livers subjected to warm ischemia in vivo often show a severe dysfunction and the release of numerous inflammatory cytokines and arachidonic acid metabolites. Cyclooxygenase (COX)-2 is the inducible isoform of an intracellular enzyme that converts arachidonic acid into prostaglandins. The aim of the study was to evaluate the effect of COX-2 inhibition and the role of Kupffer cells in IRI of the liver. METHODS: Male Wistar rats [250- 280 g body weight (BW)] were anesthetized and subjected to 30-min warm ischemia of the liver (Pringle's maneuver) and 60-min reperfusion after median laparotomy. The I/R group received no additional treatment. In the COX-2 inhibitor (COX-2I) group, the animals received 1 mg/kg BW meloxicam prior to operation. Gadolinium chloride (GdCl3) (10 mg/kg BW) was given 24 h prior to operation in the GdCl3 and GdCl3 + COX-2I groups for the selective depletion of Kupffer cells. The GdCl3 + COX-2I group received both GdCl3 and meloxicam treatment prior to operation. Blood and liver samples were obtained at the end of the experiments for further investigations. RESULTS: After 30 min of warm ischemia in vivo, severe hepatocellular damage was observed in the I/R group. These impairments could be significantly prevented by the selective COX-2 inhibition and the depletion of Kupffer cells. Alanine aminotransferase was significantly reduced upon meloxicam and GdCl3 treatment compared to the I/R group: I/R, 3,240 ± 1,262 U/l versus COX-2I, 973 ± 649 U/l, p < 0.001; I/R versus GdCl3, 1,611 ± 600 U/l, p < 0.05, and I/R versus GdCl3 + COX-2I, 1,511 ± 575 U/l, p < 0.01. Plasma levels of tumor necrosis factor alpha (TNF-α) were significantly reduced in the COX-2I treatment group compared to I/R (3.5 ± 1.5 vs. 16.3 ± 11.7 pg/ml, respectively; p < 0.05). Similarly, the amount of TxB2, a marker for COX-2 metabolism, was significantly reduced in the meloxicam treatment groups compared to the I/R group: I/R, 22,500 ± 5,210 pg/ml versus COX-2I, 1,822 ± 938 pg/ml, p < 0.001, and I/R versus GdCl3 + COX-2I, 1,530 ± 907 pg/ml, p < 0.001. All values are given as mean ± SD (n = 6). CONCLUSION: These results suggest that the inhibition of COX-2 suppressed the initiation of an inflammatory cascade by attenuating the release of TNF-α, which is an initiator of the inflammatory reaction in hepatic IRI. Therefore, we conclude that preferential inhibition of COX-2 is a possible therapeutic approach against warm IRI of the liver.

A case of laparoscopic distal gastrectomy and median arcuate ligament release for a gastric cancer patient with median arcuate ligament syndrome.

BACKGROUND: The median arcuate ligament syndrome (MALS) is a disease in which the celiac artery is compressed by the arcuate ligament and causes stenosis. If abdominal pain or an aneurysm is observed in the head of the pancreas, it is necessary to release the arcuate ligament, and recently laparoscopic surgery has been reported. However, the indication for treatment in asymptomatic cases is unknown. The treatment for asymptomatic MALS in patients with gastric cancer who are indicated for surgery is also novel. CASE PRESENTATION: A 70-year-old female was found with early gastric cancer in the middle body of the stomach. An enhanced CT scan showed no metastasis, but a gallstone and stenosis of the celiac artery due to the MALS were found. The patient underwent releasing median arcuate ligament after lymph node dissection. A median arcuate ligament was located on the ventral side of the left gastric artery stump, and the celiac artery was exposed when cutting it off. The operation time was 4 h and 59 min, and the bleeding was 6 ml. It took about 5 min to dissect the medial arcuate ligament. The postoperative course was satisfactory, and the patient was discharged 7 days after the operation. CT scan and 3-D CT angiography were performed about 2 months after the operation, and the findings revealed that the celiac artery's stenosis resolved. CONCLUSION: The patient underwent laparoscopic gastrectomy and simultaneously the median arcuate ligament release under an excellent visual field. Therefore, median arcuate ligament release may be considered if MALS is found in a gastrectomy case.

[A case of rupture of post-gastrectomy afferent loop obstruction due to invasion by pancreatic cancer].

A 77-year-old man with history of distal gastrectomy with Billroth II reconstruction for peptic ulcer disease performed 55 years ago was admitted to our hospital for diarrhea and abdominal pain. Abdominal computed tomography revealed a dilatation of the afferent loop and the duodenum, and a low density mass located in the body of the pancreas, which invaded the gastro-jejunal anastomosis site as well as the celiac axis and the superior mesenteric artery. Judging from these findings, we diagnosed this case as acute afferent loop obstruction due to an unresectable pancreatic cancer. Endoscopic decompression of the afferent loop was unsuccessful. After a while, the patient complained a severe abdominal pain, and an emergency surgery was performed under the diagnosis of rupture of the afferent loop. At laparotomy, a perforation of the jejunum located at a 15 cm anal side from Ligament of Treitz was found, and Braun's anastomosis was performed using the perforated site. The patient was treated with chemotherapy and survived for 15 months after the operation. Prompt decompression of afferent loop should be performed for preventing a rupture in case of acute obstruction of the afferent loop.

[A case of pseudo-Meigs' syndrome caused by metastatic ovarian tumors from gastric cancer].

A 54-year-old woman brought by ambulance had a lower abdominal mass and cough. Bilateral pleural effusion was revealed by X-ray and CT. An abdominal CT and MRI disclosed bilateral ovarian tumors which were considered to be metastatic tumors. GI endoscopy disclosed IIc-like advanced gastric cancer on the posterior wall of the stomach. Distal gastrectomy, total hysterectomy and bilateral adnexectomy were carried out. Gastric cancer was pathologically diagnosed as signet-ring cell carcinoma. Ovarian tumors had a similar histology, which suggested metastasis from gastric cancer. Since bilateral pleural effusion completely vanished after the ovarian resection, we concluded that this case coincided with pseudo-Meigs' syndrome. Pseudo-Meigs' syndrome of metastatic ovarian tumor from gastric cancer is very rare, only 3 cases having been reported in Japan.

[A case of severe hand-foot syndrome caused by capecitabine].

A 55-year-old woman underwent total mastectomy and axillary lymphnode dissection in 2001. Widespread lymphnode metastasis was found histologically (26/33). Neither PgR nor ER was positive. She underwent an AC regimen and paclitaxel chemotherapy. As CEA began to rise in 2002, she was given paclitaxel and docetaxel chemotherapy sequentially. As CEA rose again in 2004, capecitabine was begun. Painful erythema of the palms and soles of the feet appeared at the end of the second cycle. After admission, severe bone marrow suppression and jaundice were found. The bilateral hands, palms and soles of the feet became bullous and erosive with desquamation. The erosive lesions began to heal with epithelization in the third week. After general conditions had improved, capecitabine was restarted at a reduced dose. This patient had continued taking capecitabine even though she noticed the occurrence of the adverse effect. Patients and doctors must share confidential information when performing chemotherapy at the outpatient clinic.

Beneficial effect of cepharanthine on overcoming drug-resistance of hepatocellular carcinoma.

Despite improvement in liver surgery, patient prognoses after surgical resection for hepatocellular carcinoma (HCC) remain unsatisfactory. One of the obstacles in managing post-operative recurrence is resistance to chemotherapy. We examined the effect of Cepharanthin (CEP), a natural alkaloid extracted from Stephania cepharantha Hayata, in overcoming P-glycoprotein (P-gp)-associated doxorubicine (DOX) resistance, using 2 DOX-resistant HCC cell lines, and their DOX-sensitive parental cell lines. P-gp expression in surgically removed HCC tumours was also examined. In the in vitro study, overexpression of P-gp in the resistant cells was confirmed by immunoblotting and RT-PCR. Drug sensitivity testing with MTT assay showed that co-administration of CEP significantly enhanced cytotoxicity of DOX, but only in resistant cells. Flow cytometric analysis revealed that CEP significantly increased intracellular DOX concentration by inhibiting DOX efflux. P-gp expression in 107 patients with HCC was examined retrospectively by immunohistochemistry. P-gp was overexpressed in the tumours of 36% of these patients, especially in well-differentiated tumours that are often insensitive to chemotherapy, supporting the use of P-gp modulation as a new chemotherapeutic approach. Multivariate logistic regression analysis revealed that serum alpha-fetoprotein level was inversely related to P-gp expression. Our data suggest that co-administration of CEP with DOX may potentiate the effect of chemotherapy on drug-resistant HCC.

L-carnitine could not improve hepatic warm ischemia-reperfusion injury despite ameliorated blood flow.

BACKGROUND: Carnitine is applied to ameliorate ischemia-reperfusion (I/R) injury of several organs. However, application to hepatic I/R injury is not frequently reported. The aim of this study was to elucidate the effect of exogenous carnitine administration to ameliorate the warm hepatic I/R injury. MATERIALS AND METHODS: Male Wistar rats were divided into two groups, a carnitine group (Car);100 mg/kg of l-carnitine administration and a control group (C); vehicle administration. Thirty minutes after administration, the left hepatic lobes were given 60-min ischemia and then reperfused. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), tumor necrosis factor (TNF)-alpha, and lipoperoxides (LPO) were measured. Hepatic adenosine triphosphate (ATP) concentration was also measured. The hepatic blood flow was estimated using a Laser Doppler. The presence of apoptosis in the livers was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. RESULTS: In group Car, the blood flow of the left hepatic lobes was better recovered during the reperfusion period than in group C (P < 0.0001). Plasma levels of ALT, AST, GLDH, and TNF-alpha at 1 h after reperfusion were not significantly different between the groups. Although there were no statistical significances, ALT, AST, and TNF-alpha levels in group Car at 24 h after reperfusion tended to be higher than in group C. Plasma LPO levels were not different between the two groups. Also hepatic ATP concentration was not different between the two groups. TUNEL positive liver cells were visible only in group Car at 24 h after reperfusion, but not in the controls. CONCLUSIONS: Although carnitine administration improved the hepatic blood flow during the reperfusion period, we could not demonstrate a protective effect to the hepatic warm I/R injury.

Effect of heat shock preconditioning on NF-kappaB/I-kappaB pathway during I/R injury of the rat liver.

Hepatic ischemia-reperfusion (I/R) injury continues to be a fatal complication after liver surgery. Heat shock (HS) preconditioning is an effective strategy for protecting the liver from I/R injury, but its exact mechanism is still unclear. Because the activation of nuclear factor-kappaB (NF-kappaB) is an important event in the hepatic I/R-induced inflammatory response, the effect of HS preconditioning on the pathway for NF-kappaB activation was investigated. In the control group, NF-kappaB was activated 60 min after reperfusion, but this activation was suppressed in the HS group. Messenger RNA expressions of proinflammatory mediators during reperfusion were also reduced with HS preconditioning. Concomitant with NF-kappaB activation, NF-kappaB inhibitor I-kappaB proteins were degraded in the control group, but this degradation was suppressed in the HS group. This study shows that HS preconditioning protected the liver from I/R injury by suppressing the activation of NF-kappaB and the subsequent expression of proinflammatory mediators through the stabilization of I-kappaB proteins.

Induction of heme oxygenase-1 and dilatation of hepatic sinusoids by an administration of pyrrolidine dithiocarbamate in rat livers.

INTRODUCTION: Inducing heme oxygenase-1 (HO-1) provides the liver with various protective effects against stressful conditions. In this article, we report our use of pyrrolidine dithiocarbamate (PDTC) to induce HO-1 in the liver in vivo and its impact on hepatic microcirculation. MATERIALS AND METHODS: PDTC was injected intramuscularly into rats and the expression of HO-1 in liver tissue was assessed by measuring both mRNA and protein levels. The distribution of induced HO-1 was evaluated immunohistochemically. The effect of PDTC administration on hepatic microcirculation was evaluated using intravital microscopy (IVM). Rats were divided into three groups: PDTC administration (group P), vehicle administration only (group C), and ZnPP-an inhibitor of HO-1-administration after PDTC treatment (group Z). Sinusoidal diameters were measured 24 h after the injections. RESULTS: PDTC administration induced HO-1 strongly in the liver, but not in other organs. HO-1 mRNA expression in liver tissue peaked 3 h after PDTC injection and then gradually decreased. The protein expression reached a maximum level at 24-48 h after the injection, and its expression was dose-dependent with PDTC. Immunohistochemistry revealed that HO-1 was induced not only in Kupffer cells, but also in hepatocytes in the pericentral area. IVM showed that in group P, sinusoidal diameters in zone 3 (21.94 +/- 1.29 microm) were twice as large as those in group C (11.14 +/- 0.28 microm, P < 0.0001). This dilation of sinusoids was completely reversed by ZnPP (10.95 +/- 0.37 microm, P < 0.0001). CONCLUSION: A single administration of PDTC induced HO-1 in the liver with remarkable sinusoidal dilation. PDTC administration, therefore, may be a useful, new strategy in place of other stress preconditioning.

Impact of novel histone deacetylase inhibitors, CHAP31 and FR901228 (FK228), on adenovirus-mediated transgene expression.

BACKGROUND: Histone deacetylase inhibitors (HDIs) are known to enhance adenovirus (Ad)-mediated transgene expression. Recently, novel HDIs, including cyclic hydroxamic-acid-containing peptide 31 (CHAP31) and FR901228 (FK228), have been developed. METHODS: The effects of these two novel HDIs on Ad-transduced or endogenous gene expression were investigated. Acetylation of core histones and the expression of the coxsackie and adenovirus receptor (CAR) in HDI-treated cells were examined using Western blot and a quantitative reverse transcription polymerase chain reaction (TaqMan RT-PCR), respectively. Their in vivo effect on adenoviral gene expression was investigated in BALB/c mice. RESULTS: Both compounds enhanced and prolonged Ad-mediated beta-galactosidase expression more effectively than did trichostatin A, a classic HDI. The same effect was observed in Ad-transduced heat shock protein 72 (HSP72), but not in hyperthermia-induced endogenous expression of HSP72, suggesting that the effect is specific for transduced gene expression. Hyperacetylation of core histones induced by HDIs was considered responsible for the augmentative effects of gene expression. Intravenous administration of either CHAP31 or FR901228 enhanced beta-galactosidase expression in mice infected with AdLacZ. CONCLUSIONS: CHAP31 and FR901228 amplified Ad-mediated transgene expression. The enhancement of transgene expression by HDIs may result in fewer vector doses for necessary gene expression, helping to alleviate disadvantages caused by Ad vectors. This could be a useful tool in overcoming current limitations of gene therapy using adenovirus vectors.