Károly Kalmár-Nagy

Changes and Effect of PACAP-38 on Intestinal Ischemia-Reperfusion and Autotransplantation

Tissue injury caused by cold preservation and reperfusion during small bowel transplantation remains an unsolved problem. Increasing evidence suggests that pituitary adenylate cyclase-activating polypeptide (PACAP) has protective effects in several ischemia-reperfusion (I/R) models. This study investigated the effect of PACAP-38 on oxidative stress in autotransplanted intestine. We established sham-operated, I/R, and autotransplanted groups in Wistar rats (n = 55). We applied ischemia for 1 (GI), 2 (GII), or 3 hours (GIII). In autotransplanted groups, we performed total orthotopic intestinal autotransplantation. Grafts were preserved in University of Wisconsin (UW) solution for 1 (GIV), 2 (GV), 3 (GVI), or 6 (GVII) hours and in PACAP-38-containing UW for 1 (GVIII), 2 (GIX), 3 (GX), or 6 (GXI) hours. Reperfusion lasted 3 hours in each group. Endogenous PACAP-38 values were measured by radioimmunoassay. Oxidative stress parameters malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) were measured in tissue homogenates. Concentration of endogenous PACAP-38 significantly decreased in GI to GIII compared with the sham-operated animals following I/R periods (P < .05). Cold preservation in UW and reperfusion of the intestine increased the level of tissue MDA in GIV to GVII, which correlated with the duration of cold storage. The content of GSH decreased in GIV to GVII to levels that were significantly different between GIV and GVIII and between GVII and GXI. SOD activity decreased dramatically in GIV to GVII with significantly higher activity in GIX to GXI. Our findings confirmed that I/R decreased endogenous PACAP-38 concentration. Administration of PACAP-38 to UW solution mitigated the oxidative injury during intestinal autotransplantation.

Incidence of Nonmelanoma Skin Cancer After Human Organ Transplantation: Single-Center Experience in Hungary

There is increasing evidence that nonmelanoma skin cancers (NMSCs) are the most frequently observed tumors in transplant recipients. The incidence of posttransplantation NMSC was determined using our dermatologic screening program. Included in the study were 116 white adults (70 men and 46 women; median age, 49.3 years) who had undergone kidney or combined kidney-pancreas transplantation, with follow-up from September 2008 to December 2009. All patients underwent a full skin examination for NMSC, and completed a standardized questionnaire. Screening resulted in detection of 16 NMSCs in 11 patients out of 116 (9.5%). Lesions were equally distributed by sex, and were detected at a median of 4.1 years posttransplantation. Histologic analysis verified 13 basal cell carcinomas and 3 squamous cell carcinomas (ratio, 4:1). The incidence of NMSC was significantly greater in patients who received cyclosporine immunosuppression therapy (16 vs 1; P < .05), had experienced 2 or more painful sunburns before transplantation (10 vs 11), or worked outdoors (10 vs 11). These data indicate the relevance of skin cancer surveillance in transplant recipients. Our results correspond to international statistics except for the ratio of basal cell carcinoma to squamous cell carcinoma. Further studies are needed to elucidate the reasons for this difference.

Influence of Pituitary Adenylate Cyclase-Activating Polypeptide on the Activation of Mitogen Activated Protein Kinases Following Small Bowel Cold Preservation

Cold preservation prior to small bowel transplantation can moderate tissue oxidative injury. This stress triggers several intracellular pathways via mitogen activated protein (MAP) kinases. MAP kinases include the extracellular signal related kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAP kinase. Pituitary adenylate cyclase-activating polypeptide (PACAP) plays a central role in intestinal physiology. We sought to investigate the effect of PACAP on the activation of MAP kinases during cold preservation of the small bowel. Total orthotopic intestinal autotransplantation was performed on 40 Wistar rats. Perfused grafts were stored in University of Wisconsin (UW) solution for 1 (GI), 2 (GII), 3 (GIII), or 6 hours (GIV) without or with 30 PACAP, namely 1 (GV), 2 (GVI), 3 (GVII), or 6 hours (GVIII). After 3 hours of reperfusion in all groups, the activation of MAP kinases were measured using immunocytochemistry of small bowel tissue. Among the UW preserved grafts (GI-GIV), phosphorylated ERK1/2 level were decreased, while phosphorylated JNK1/2 and p38 MAP kinase activation were elevated compared with control levels. In GV-GVIII PACAP we observed enhanced phospho-ERK1/2 appearance with decreased JNK and p38 MAP kinase activity at the end of the reperfusion periods. We concluded that cold preservation decreased phosphorylated ERK1/2 levels and increased JNK1/2 and p38 MAP kinase activities, which meant that cold storage triggered apoptotic cell death. In contrast, PACAP treatment induced signalling pathways protective against oxidative injury by MAP kinases in bowel tissue.

PARP Inhibition Attenuates Acute Kidney Allograft Rejection by Suppressing Cell Death Pathways and Activating PI-3K-Akt Cascade

Background Novel immunosuppressive therapy facilitates long term allograft survival, but acute tubular necrosis and ischemia-reperfusion during transplantation can compromise allograft function. These processes are related to oxidative stress which activates poly- (ADP-ribose) polymerase (PARP) contributing to the activation of cell death pathways. Here we raised the possibility that PARP inhibition curbs cell death pathways and shifts kinase signaling to improved graft survival. Methods Findings In an acute rat kidney rejection model, we provided evidence that the PARP inhibitor 4-hydroxy-quinazoline (4OHQ) attenuates rejection processes initiated oxidative/nitrosative stress, nuclear poly-ADP-ribosylation and the disintegration of the tubulo-interstitial structures. The PARP inhibitor attenuated rejection processes induced pro-apoptotic pathways by increasing Bcl-2/Bax ratio and suppressing pro-apoptotic t-Bid levels. In transplanted kidneys, the cell death inducing JNK1/2 is normally activated, but PARP inhibition suppressed this activation with having only modest effects on ERK1/2 and p38 MAP kinases. In untreated transplanted kidneys, no significant alterations were detected in the cytoprotective PI-3K-Akt pathway, but the PARP inhibitor significantly activated Akt (by S473 phosphorylation) and suppressed GSK-3β, as well as activated acute NF-kappaB activation contributing to graft protection. Conclusion These data show the protective role of PARP inhibition on graft survival by attenuating poly-ADP-ribosylation, oxidative stress, suppressing pro-apoptotic and increasing anti-apoptotic protein level, and by shifting MAP kinases and PI-3-K-Akt pathways to cytoprotective direction. Thus, addition of PARP inhibitors to standard immunosuppressive therapies during kidney transplantation may provide increased protection to prolong graft survival.

Changes in oxidative stress in patients screened for skin cancer after solid-organ transplantation

Transplant recipients are at high risk of nonmelanoma skin cancer (NMSC). Ultraviolet radiation can generate oxygen free radicals (OFRs), leading to oxidative stress and carcinogenesis, primarily during immunosuppression therapy. In the present study, changes in oxidative stress were examined in transplant recipients with and without NMSC. The study included 116 white adults who had undergone kidney or combined kidney-pancreas transplantation. Dermatologic follow-up revealed 16 NMSCs (13.8%). To monitor oxidative stress, peripheral blood samples were used to measure malondialdehyde (MDA), reduced glutathione, sulfhydryl (-SH) groups, OFRs, and activity of myeloperoxidase, superoxide dismutase, and catalase. The mean (SD) plasma MDA concentration was significantly greater in patients without NMSC compared with healthy control individuals (0.48+/-0.05 nmol/mL; P < .05), whereas MDA concentration in hemolysate was slightly increased. In peripheral blood samples, the MDA concentration in both plasma (0.71+/-0.03 nmol/mL) and hemolysate (87.74+/-1.25 nmol/mL) was significantly increased in the NMSC group compared with the healthy control group (0.24+/-0.05 nmol/mL vs 75.87+/-2.8 nmol/mL; P < .05) or patients without NMSC (0.48+/-0.04 nmol/mL vs 79.62+/-2.77 nmol/mL; P < .05). The reduced glutathione concentration was significantly decreased in the -SH groups compared with the healthy control group (P < .05). Antioxidant activity of myeloperoxidase (0.78+/-0.05 IU/mL) and catalase (1855.8+/-45.41 IU/mL) was significantly increased in the group without NMSC compared with the healthy control group (0.41+/-0.1 IU/mL vs 1642.07+/-82.96 IU/mL) and the NMSC group (0.93+/-0.03 IU/mL vs 2180.5+/-15.03 IU/mL). The superoxide dismutase activity was decreased slightly but not significantly. Total production of OFRs was significantly greater in the NMSC group compared with the non-NMSC group or the healthy control group (P < .05). These findings suggest that an imbalance exists between pro-oxidant and antioxidant status in transplant recipients, with a significant difference in patients with vs without NMSC.

Az epeutak ritka anatómiai variánsa − A jobb ductus hepaticus intraparenchymalis csatlakozása a bal oldali ductus hepaticusba

Absztrakt: A szerzők egy 67 eves ferfi beteg esetet ismertetik, akinel előzőleg a maj II. szegmentumaban kepalkoto vizsgalatokkal igazolt terfoglalas miatt II, III szegment teljes es a IV. szegment reszleges eltavolitasat vegeztek. Műtet utani icterus jelent meg, emelkedő tendenciat mutato szerum bilirubin koncentracioval. Kepalkoto vizsgalatok elvegzese utan reoperatiora kerult sor. A műtet alatt derult feny a ritka epeuti variansra. A primer műtetnel a rezekcio soran lekotesre kerult a jobb oldali ductus hepaticus, ami intraparenchimalisan omlott a bal oldali ductus hepaticusba. Az erintetlenul hagyott hilusban nem tűnt fel a jobb extrahepaticus epeut hianya. Az epeelvezetes Roux-Y-kaccsal vegzett hepatico jejunostomiaval kerult megoldasra.

Changes of Progesterone-Induced Blocking Factor in Patients After Kidney Transplantation

The prediction of graft rejection can play an important part in graft survival. Analysis of immune reactions has shown that graft rejection shares mechanisms with recurrent abortions during pregnancy. Progesterone-induced blocking factor (PIBF), a mediator of progesterone that blocks natural killer cell activity in peripheral blood, produces antiabortive effects. The aim of this study was to examine the PIBF concentration in the urine of transplanted recipients. The study included 116 white adults (70 men and 46 women) of median age 49.3 years, who had undergone kidney transplantations. The median duration after transplantation was 3.46 years. The average period between renal disease and our measurement was 12.3 years, and the median interval between graft rejection and our study was 1.75 years. Urine samples were used to measure PIBF concentrations by an enzyme-linked immunsorbent assay. PIBF urinary concentrations decreased significantly in patients who experienced ≥1 rejection episode (31.8±2.2 ng/mL) compared with those without any episode (22.7±1.2 ng/ml; P<.01). Moreover, the urinary PIBF level was significantly lower among patients who had increased creatinine and urea nitrogen levels in blood samples (P<.05 and P<.01, respectively). Decreased PIBF values in kidney transplant patients followed previous rejection episodes. A close negative correlation was observed between urinary PIBF concentrations and blood levels of creatinine and urea nitrogen. These findings suggested that PIBF detection may predict graft rejection in transplant recipients.