Dimitrios Takoudas

Intramuscular Administration of Very High Dose of a-Tocopherol Protects Liver from Severe Ischemia/Reperfusion Injury

The effect of intramuscular administration of high (30 mg/kg body weight for 3 days) or very high (300 mg/kg body weight for 3 days) doses of a-tocopherol to Wistar rats subjected to total severe warm hepatic ischemia and reperfusion was investigated. After a 60-minute period of total hepatic ischemia and 120 minutes of reperfusion, animals were killed, and liver samples were taken for determination of malondialdehyde (MDA) and histological examinations. Blood samples were also taken for assay of serum a-tocopherol, alanine transaminase (ALT), aspartate transaminase (AST), and lactic dehydrogenase (LDH). Additional animals were followed for a 7-day survival rate determination. Results showed that ischemia and reperfusion decreased the survival rate to 10%, whereas the levels of AST, ALT, and LDH in serum were increased compared with levels in animals that were sham operated. The MDA concentrations in liver were also increased, from 1.142 to 1.567 nmoles/g, whereas the levels of a-tocopherol in serum were decreased from 10.20 to 1.80 mmol/L. Pretreatment with a-tocopherol increased the viability to 50% and 70%, for the high and very high doses, respectively, and decreased the levels of AST, ALT, and LDH in serum. It also decreased the MDA concentrations in liver to 0.975 and 0.774 nmoles/g for the high and very high doses of a-tocopherol, respectively, whereas it increased the level of a-tocopherol in serum to 11.25 and 13.02 mmol/L for the high and very high doses, respectively. Histological examinations showed protection of the liver parenchyma in the animals treated with a-tocopherol.

Attenuation of intestinal ischemia/reperfusion induced liver and lung injury by intraperitoneal administration of (−)-Epigallocatechin-3-gallate

The aim of this study was to evaluate the effect of ( − )-epigallocatechin-3-gallate (EGCG), a natural antioxidant, on liver and lungs after warm intestinal ischemia/reperfusion (I/R). Thirty male Wistar rats were equally divided into a sham-operation group, an intestinal I/R group and an intestinal I/R group pretreated with EGCG intraperitoneally. Intestinal ischemia was induced by occlusion of the superior mesenteric artery for 60 min followed by reperfusion for 120 min. Immediately after reperfusion, liver, lung and blood samples were collected and analyzed. Results showed that intestinal I/R increased the levels of aspartate (AST) and alanine (ALT) transaminase in serum to 987 and 752 IU/l, respectively. Malondialdehyde (MDA) increased in liver to 1.524 nmol/g in the group subjected to intestinal I/R compared to 0.995 nmol/g in the sham operation group. MDA was also increased in lungs to 1.581 nmol/g compared to 0.896 nmol/g in the sham operation group. Myeloperoxidase (MPO) increased in liver, after intestinal I/R, to 5.16 U/g compared to 1.59 U/g in the sham operation group. MPO was also increased in lungs to 3.89 U/g compared to 1.65 U/g in the sham operation group. Pretreatment with EGCG decreased serum levels of AST and ALT to 236 and 178 IU/l, respectively. It also decreased mean MDA levels in liver and lungs to 1.061 and 1.008 nmol/g, respectively, and mean MPO levels in liver and lungs to 1.88 and 1.71 U/g, respectively. Light microscopy and transmission electron microscopy examinations showed significant alteration in liver and lungs and protection of liver and lung parenchyma in the animals treated with EGCG.

Attenuation of Liver Ischemia/Reperfusion Induced Apoptosis by Epigallocatechin-3-Gallate Via Down-Regulation of NF-κB and c-Jun Expression

INTRODUCTION Hepatic ischemia/reperfusion (I/R) activates Kupffer cells and initiates severe oxidative stress with enhanced production of reactive oxygen species (ROS) and tumor necrosis factor-alpha (TNF-alpha). ROS and TNF-alpha mediate the expression of nuclear factors and kinases, activating the signal transduction pathway, and triggering apoptosis. The aim of our study was to evaluate the potential protective effect of (-)-epigallocatechin-3-gallate (EGCG) administration in inhibition of apoptosis by attenuating the expression of NF-kappaB, c-Jun, and caspase-3 in a model of severe hepatic I/R. MATERIALS AND METHODS Thirty Wistar rats were allocated into three groups. Sham operation, I/R, and I/R-EGCG 50mg/kg. Hepatic ischemia was induced for 60min by Pringles maneuver. Malondialdehyde (MDA), myeloperoxidase (MPO), light histology, scanning electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and immunocytochemistry for NF-kappaB, c-Jun, caspase-3, analysis on liver specimens and aspartate (AST), and alanine (ALT) transferases analysis in serum, were performed 120min after reperfusion. RESULTS Apoptosis as indicated by TUNEL and caspase-3 was widely expressed in the I/R group but very limited in the EGCG treated group. Liver was stained positive for NF-kappaB and c-Jun in the I/R group but failed to be stained positive in the EGCG treated group. MDA, MPO, AST, and ALT showed marked increase in the I/R group and significant decrease in EGCG treated group. Significant alterations of liver specimens were observed by light histology and transmission electron microscopy whilst pretreatment with EGCG resulted in parenchymal preservation. CONCLUSIONS Administration of EGCG is likely to inhibit I/R-induced apoptosis and protect liver by down-regulating NF-kappaB and c-Jun signal transduction pathways.

The Protective Effect of α-Tocopherol and GdCl3 Against Hepatic Ischemia/Reperfusion Injury

PurposeTo evaluate the combined effect of α-tocopherol and gadolinium chloride (GdCl3) in reducing lipid peroxidation after severe hepatic ischemia/reperfusion (IR) injury.MethodsSixty male Wistar rats, 200–250 g, were randomly divided into six equal groups. There were two sham operation (SHAM) groups, two untreated IR groups, and two IR groups treated with GdCl3 and α-tocopherol (IRGT). After 60 min of total hepatic ischemia and 120 min reperfusion, one of each group was killed, liver samples were taken for malondialdehyde (MDA) and myeloperoxidase (MPO) analysis and light microscopy examination, and blood samples were analyzed for aspartate (AST) and alanine (ALT) transaminase, lactate dehydrogenase (LDH), and α-tocopherol content. The remaining groups were monitored for survival rate determination.ResultsThe mean MDA and MPO values in the SHAM, IR, and IRGT groups, respectively, were 1.117, 1.476, and 0.978 nmol/g wet tissue and 1.49, 6.26, and 1.78 (U/g). The mean α-tocopherol values in the SHAM, IR, and IRGT groups, respectively, were 10.4, 1.9, and 12 µmol/l. The mean serum AST, ALT, and LDH values were significantly higher in the IR group than in the SHAM group (P < 0.001), and significantly lower in the IRGT group than in the IR group (P < 0.001). Light microscopy examination revealed more severe congestion and vacuolization in the IR group than in the SHAM group, and minimal congestion and vacuolization in the IRGT group. Survival was significantly higher in the IRGT group than in the IR group.ConclusionThe administration of GdCl3 and α-tocopherol is likely to protect the liver against lipid peroxidation by suppressing Kupffer cell and polymorphonuclear leukocyte activation and enhancing endogenous antioxidant activity.

The natural history of vascular access for hemodialysis: A single center study of 2,422 patients

BACKGROUND Our objective is to provide provision of primary and secondary patency rates data and incidence of complications. Despite the publication of some review articles and small prospective trials about vascular accesses, controversy still exists regarding the choice of the outflow conduit and especially the choice of the fistula to be formed in secondary and tertiary access procedures. METHODS This is a retrospective study of 2,422 consecutive patients who underwent 3,685 vascular access procedures in a tertiary care hospital, including radial-cephalic (RCAVF), brachial-cephalic (BCAVF), brachial-basilic (BBAVF), and prosthetic graft (PTFE) fistulas. Maximum follow-up period was 20 years. Actuarial patency rates were obtained by Kaplan-Meier analysis. RESULTS The median primary patency (days) of the most common 1st choices for vascular access were 712 (95% CI: 606, 818), 1,009 (95% CI: 823, 1,195), and 384 (95% CI: 273, 945) days for RCAVF, BCAVF, and PTFE, respectively. The median secondary patency was 1809 days (95% CI: 1,692, 1,926) for the RCAVF. The median primary patency of BBAVF (2nd or 3rd choice for vascular access) was 1,582 days (95% CI: 415, 2,749). The cumulative incidence of clinically important complications for the patients who received a RCAVF, BCAVF, BBAVF, and u-PTFE was 0.25, 0.57, 0.33, and 0.61 per patient-year, respectively. CONCLUSION We advocate maximal use of autogenous conduits, except probably the case of the older diabetic patient, in whom access at the antecubital fossa should be the first choice. BBAVF is an excellent fistula and should probably be constructed before prosthetic graft placement.

Inhibition of intestinal ischemia/repurfusion induced apoptosis and necrosis via down-regulation of the NF-kB, c-Jun and caspace-3 expression by epigallocatechin-3-gallate administration

Intestinal ischemia/reperfusion (I/R) produces reactive oxygen species (ROS) activating signal transduction and apoptosis. The aim of this study was to evaluate the effect of (−)-epigallocatechin-3-gallate (EGCG) administration in inhibition of apoptosis by attenuating the expression of NF-kB, c-Jun and caspace-3 in intestinal I/R. Thirty male wistar rats were used. Group A sham operation, B I/R, C I/R-EGCG 50 mg/kg ip. Intestinal ischemia was induced for 60 min by clamping the superior mesenteric artery. Malondialdehyde (MDA), myeloperoxidase (MPO), light histology, Fragment End Labelling of DNA (TUNEL), immunocytochemistry for NF-kB, c-Jun and caspace-3 analysis in intestinal specimens were performed 120 min after reperfusion. Apoptosis as indicated by TUNEL and Caspace-3, NF-kB and c-Jun was widely expressed in I/R group but only slightly expressed in EGCG treated groups. MDA and MPO showed a marked increase in the I/R group and a significant decrease in the EGCG treated group. Light histology showed preservation of architecture in the EGCG treated group. In conclusion, EGCG pre-treatment is likely to inhibit intestinal I/R-induced apoptosis by down-regulating the expression of NF-kB, c-Jun and caspase-3.

Impact of double-j ureteric stent in kidney transplantation: single-center experience.

We retrospectively evaluated the use of double-j stent and the incidence of urological complications in 2 groups of patients who received a kidney transplant. From January 2005 to September 2007 we studied 172 patients receiving kidney transplants, 65 and 107 from living and cadaver donors, respectively. From the 172 patients, a total of 34 were excluded due to ureterostomy or Politano-Leadbetter ureterovesical anastomosis. Another 21 patients were excluded from the study due to graft loss due to acute or hyperacute rejection, cytomegalovirus (CMV) infection, or vascular complication. The remaining patients were divided into 2 groups: group A (44 patients) and B (73 patients) with versus without the use of a double-j-stent, respectively. The 2 groups were comparable in terms of donor and recipient gender, ischemia time, and delayed graft function. We failed to observes significant differences between the 2 groups in mean hospital stay (23 +/- 9 and 19 +/- 9), urinary leak (2.3% and 4.1%), and urinary tract infection (20.4% and 19.2%), among groups A and B, respectively. The only difference observed concerned the gravity of the urinary leak; no surgical intervention was needed among the double-j stent group versus 2 patients demanding ureterovesical reconstruction in the nonstent group. In conclusion, our data suggested that the routine use of a double-j stent for ureterovesical anastomosis neither significantly increased urinary tract infection rates, nor decreased the incidence of urinary leaks, but may decrease the gravity of the latter as evidenced by the need for surgical intervention.

Successful, combined long-term treatment of cerebral aspergillosis in a liver transplant patient.

Invasive aspergillosis has long been recognized as one of the most significant and often fatal opportunistic fungal infections in liver transplant recipients. We report a case of a liver transplant recipient who developed an Aspergillus fumigatus brain abscess that produced significant neurologic symptoms. The patient was managed successfully with a combination of surgery and medical treatment with Voriconazole. To our knowledge, this is the second such case reported in the literature.

Association between the heme oxygenase-1 promoter polymorphism and renal transplantation outcome in Greece.

BACKGROUND Heme oxygenase-1 (HO-1) is the enzyme that catabolizes heme into carbon monoxide, biliverdin, and free iron. The induction of this enzyme is an important cytoprotective mechanism, which occurs as an adaptive and beneficial response to a wide variety of oxidant stimuli. HO-1 has recently been suggested to protect transplants from ischemia/reperfusion and immunologic injury. HO-1 inducibility is mainly modulated by a (GT)(n) repeat polymorphism in the promoter region, and has been shown that short repeats (S) are associated with greater upregulation of HO-1, compared with long repeats (L). In the present study we investigated the influence of this HO-1 gene polymorphism on clinical outcome after transplantation and on renal transplant function. METHODS DNA from 175 donor/recipient pairs who underwent transplantation between October 2002 and June 2007 was genotyped. We divided the HO-1 alleles into 2 subclasses, the S ≤ 27 repeats and L > 27 repeats. RESULTS There has been significant relevance between the genotype of the donor and the outcome of the graft, as far as recipients with normal graft function and recipients with deteriorated graft function are concerned (P = .021). In patients with normal graft function, grafts from L-homozygotes were found in 24%, whereas in patients with deteriorated function, grafts from L-homozygotes exhibited in higher rate (50%). Neither the donors nor the recipients polymorphism influenced the graft survival (log-rank test P = .228 for the donors and log-rank test P = 0.844 for the recipients). There was no evidence of a gene-dose effect on graft survival (P = .469). Recipients of allografts from S-carriers donors had significantly lower serum creatinine levels at 24 months compared with recipients of allografts from L-homozygotes donors (P = .016).

Tc-99m Sestamibi Accuracy in Detecting Parathyroid Tissue Is Increased When Combined With Preoperative Laboratory Values: A Retrospective Study in 453 Greek Patients With Chronic Renal Failure Who Underwent Parathyroidectomy

PURPOSE Technetium(99m) sestamibi (MIBI) has poor sensitivity and specificity when applied to patients with secondary hyperparathyroidism. We investigated whether the combination of MIBI with preoperative parameters increased its accuracy. PATIENTS AND METHODS This prospective study of 453 consecutive patients with secondary hyperparathyroidism who underwent parathyroidectomy (bilateral neck exploration) included preoperative MIBI scintigraphy compared with intraoperative and histopathology findings. Four patient groups were comprised according to the results: true positivity (TP), true negativity (TN), false positivity (FP), and false negativity (FN). RESULTS MIBI scintigraphy sensitivity, specificity, positive predictive value, and negative predictive value were 66.4%, 50%, 76.3%, and 37.9%, respectively. For the TP group, mean age and mean parathormone (PTH) value were 56 years and 754, respectively. The binary logistic regression for the prediction (1) or not (2) of TP was as follows: 0.138 + (-.011) * age + 0.001 * PTH (P = .012). For the TN group, the mean age and mean phosphate value were 49 years and 5.24, respectively. The binary logistic regression for the prediction (1) versus not (2) of the TN was as follows: -1.463 + age * (-.029) + phosphate * 0.233 (P = .012). CONCLUSION MIBI accuracy in patients with secondary hyperparathyroidism was increased when combined with other preoperative parameters. The sensitivity was increased as patients were older and the PTH levels were lower. The specificity was increased as patients were younger and the phosphate levels were lower.