Protective effects of deferoxamine mesylate preconditioning on pancreatic tissue in orthotopic liver autotransplantation in rats.

BACKGROUND: Deferoxamine mesylate is known to ameliorate tissue ischemia-reperfusion injury. This study was designed to explore the impact of deferoxamine mesylate preconditioning (DMP) on pancreatic tissue and its possible effects during orthotopic liver autotransplantation. METHODS: A modified orthotopic liver autotransplantation model was used to simulate pancreatic ischemia-reperfusion injury. Sprague-Dawley rats (0.25-0.30 kg) were randomly divided into normal control, autotransplantation (AT), systemic deferoxamine mesylate preconditioning (SDMP), and partial deferoxamine mesylate conditioning (PDMC) groups. The SDMP group was injected with deferoxamine mesylate (75-90 mg; 300 mg/kg), via the celiac artery at 24 and 48 hours before surgery. During surgery, the PDMC group underwent liver perfusion by means of deferoxamine mesylate solution (20 ml; 0.6 mmol/L) rather than Ringer's lactate solution, with no prior preconditioning. At 6, 24, and 48 hours after surgery, the rats were sacrificed to sample their pancreatic tissues for the expression of hypoxia-inducible factor-1α (HIF-1α) and malondialdehyde (MDA) content. The samples were subjected to blood chemistry analyses, light and transmission electron microscopic morphological studies, and quantitative measurement of HIF-1α expression. RESULTS: The serum levels of amylase, lipase, and MDA in SDMP and PDMC groups were significantly lower than those in the AT group at 6, 24, and 48 hours after orthotopic liver autotransplantation (P < .05). Light and electron microscopic analyses showed much more severe pancreatic injury in the autotransplantation than in the SDMP and PDMC groups. The HIF-1α expression was increased in the SDMP and PDMC groups more than in the autotransplantation group (P < .05). CONCLUSIONS: Deferoxamine mesylate preconditioning protected pancreatic tissue in orthotopic liver autotransplantation in rats. Inhibition of oxidative toxic reactions and up-regulated expression of HIF-1α protein are possible mechanisms.

Role of vascular endothelial growth factor in protection of intrahepatic cholangiocytes mediated by hypoxic preconditioning after liver transplantation in rats.

OBJECTIVE: To investigate the effect on intrahepatic cholangiocytes mediated by hypoxic preconditioning (HP) after liver transplantation and the role of vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: This experiment was based on a model of rat orthotopic liver autotransplantation. Sprague-Dawley rats were randomly divided into 3 groups: normal control, autotransplantation (AT), and HP. The HP group was subjected to 8% oxygen atmosphere for 90 minutes before surgery. At 6, 12, 24, and 48 hours after autotransplantation, the rats were killed for testing .Serum total bilirubin, direct bilirubin, and alkaline phosphatase concentrations were determined. The microstructure of cholangiocytes and the ultramicrostructure of cholangioles were determined. Immunohistochemistry was used to detect the expression of VEGF and the proliferation rate of cholangiocytes. RESULTS: Total bilirubin, direct bilirubin, and alkaline phosphatase concentrations in the AT group increased considerably more than in the HP group during the entire interval (P < .05). Light microscopy demonstrated that the microstructure of cholangiocytes in the AT group was damaged more seriously than in the HP group. At transmission electron microscopy, the ultramicrostructure of cholangioles was changed more obviously than in the HP group. The expression of VEGF on cholangiocytes and the proliferation rate of cholangiocytes were higher in the HP group than in the AT group over the entire experiment (P < .05). CONCLUSION: Hypoxic preconditioning has a protective effect on cholangiocytes after liver autotransplantation. The mechanism may be related to HP-induced overexpression of VEGF on cholangiocytes.

AGNORS in skin lesions of cutaneous malignant lymphomas and pseudolymphomas.

Nucleolar organiser regions (NORs) are loops of DNA situated on the short arms of acrocentric chromosomes 13, 14, 15, 21, and 22. They can be demonstrated in formalin-fixed paraffin-embedded sections by a one step silver technique; the resultant black structures are called AgNORs. The technique was used in 71 patients with cutaneous malignant lymphomas (CML) and 9 cutaneous pseudolymphomas (CPL). AgNORs in 200 nuclei were scored and the means, standard deviation and standard error of the means calculated. Counts were as follows: mycosis fungoides (MF) I (premycotic stage) 1.17 +/- 0.09, SEM = 0.01; MF II (infiltrating stage) 1.17 +/- 0.01, SEM = 0.02; MF III (tumor stage) 3.55 +/- 0.87, SEM = 0.43: cutaneous peripheral T cell lymphomas other than MF and Sezary's syndrome (SS) (CPTL) 2.55 +/- 1.11, SEM = 0.35; SS 1.52; cutaneous B cell lymphomas (CBCL) 2.18 +/- 0.18, SEM = 0.06; CPL 1.17 +/- 0.1, SEM = 0.03. There was a significant difference between counts for CML (MF III, CPTL, CBCL and SS) and CPL. Significant difference was also noted between scores for MF III and CBCL, and especially counts between tumor stage (MF III and CPTL) and pretumor stage (MF I and MF II) of cutaneous peripheral T cell lymphomas. Although the AgNOR technique is in the stage of research, it proves to be helpful in differentiating CML and CPL other than separating MF I and MF II from CPL.

[Nail fold microcirculation in patients with chest malignancy].

Nail fold microcirculation was observed in 90 patients suffering from chest malignancies. 33 were patients with esophageal cancer, 41 cancer of gastric cardia, 4 esophageal and cardiac cancer, 11 lung cancer and 1 malignant neurogenic tumor in the posterior mediastinum. The results indicate that, in cancer patients, marked microcirculatory disturbances are present in the form of marked exudation, cloudy visual field, abnormal and dilated capillary loops, granular and slow blood flow. There is no obvious difference in the various kinds of malignancies. Nor is there any difference between the operable and inoperable cases. Indication of operation is not predicted by this method. The probable cause and clinical significance of microcirculatory disturbances are discussed.