Impaired liver regeneration following partial hepatectomy using the Pringle maneuver: Protective effect of mesna

Background and Aim: We investigated the role of the prophylactic administration of the antioxidant 2‐mercaptoethane sulfonate (mesna) on the hepatocyte‐regenerating capacity following partial hepatectomy (PH) with concurrent Pringle maneuver. Methods: Wistar rats were subjected to PH (70% hepatectomy), 30 min Pringle maneuver, PH plus Pringle with or without mesna pretreatment (400 mg/kg, per os, 3 h before Pringle), or sham operation. At 24 h, 48 h, 72 h, and 1 week after operation, relative liver weight, hepatocyte mitotic activity (mitotic index), the histopathological score and serum aspartate aminotransferase, and alanine aminotransferase concentrations were assessed. At 1 h after operation, oxidative stress markers (glutathione to glutathione disulfide ratio, malondialdehyde concentration, and superoxide dismutase activity) and nuclear factor‐κB (NF‐κB) activity were assessed. Results: Hepatectomy stimulated the regenerating process and induced mild oxidative stress and the activation of NF‐κB in hepatocytes, while causing tissue injury in the remnant liver. When PH was performed under Pringle maneuver, hepatocyte mitotic activity was substantially suppressed, although Pringle alone initiated a delayed regenerating response. Furthermore, Pringle maneuver deteriorated oxidative stress markers, markedly increased NF‐κB activity, and aggravated tissue injury, as compared to hepatectomy alone. Mesna pretreatment prevented the Pringle‐induced antimitotic effect and the induction of oxidative stress, inhibited the activation of NF‐κB, while attenuating liver injury after PH under Pringle. Conclusion: The excessive activation of NF‐κB is related to the suppression of hepatocyte‐regenerating activity following PH with concurrent liver ischemia. Mesna pretreatment protects the liver against the Pringle‐induced antimitotic effect after PH via the prevention of oxidative stress and the inhibition of NF‐κB activation.     

Mutational study of the role of N-terminal amino acid residues in tetrachlorohydroquinone reductive dehalogenase from Sphingomonas sp. UG30

This research presents the first extensive mutational study of N-terminal amino acids necessary for activity of a bacterial Zeta class glutathione transferase (GST). Our studies on UG30 tetrachlorohydroquinone reductive dehalogenase (PcpC) revealed that, similar to other Zeta class GSTs, N-terminal Ser and Cys residues play critical roles in glutathione binding and their mutation results in functional and structural changes to PcpC. Mutation of the N-terminal Ser and Cys residues decreased the apparent temperature optimum (by 6-10 °C) and maximum (by 5 °C) of PcpC. Also, mutation of Ser12 and Ser15 resulted in structural changes that were accompanied by the emergence of substrate inhibition. Mutation of the N-terminal Cys residue adversely affected the rate of the enzymatic reaction, but not on the metabolites formed. This study adds to the knowledge that, despite low sequence homology for the Zeta GST protein family, differences in preferred electrophilic substrates, and the manner in which glutathione is utilized in catalysis, GSTs from prokaryotic and eukaryotic organisms rely upon the same critical amino acids for glutathione binding.     

Treatment of intermediate- and high-grade non-Hodgkin's lymphoma using CEOP versus CNOP

INTRODUCTION: During the last few years epirubicin (E) and mitoxantrone (M) (Novantrone) have been used in the treatment of non-Hodgkin's lymphoma (NHL), because of their favorable principal profile. In particular, M has less severe non-hematological toxicity. PATIENTS AND METHODS: A randomized multicenter phase III study was conducted in order to compare the efficacy and toxicity of CEOP and CNOP in intermediate- and high-grade NHL. CEOP (arm A) consisted of cyclophosphamide 1000mg m(-2), vincristine 2mg, E 70mg m(-2) on day 1 and prednisone 60mg on days 1-7. The CNOP regimen (arm B) was identical to CEOP except for replacement of E by M at a dose of 12mg m(-2). Randomization was stratified according to stages I-IV. From September 1993 to March 1999, 249 patients registered for the trial. Patient characteristics were equally distributed in the two arms, except for age and International Prognostic Index (IPI) groups. RESULTS: There were no significant differences between the two groups in the rates of complete (CR) and partial response (PR). The overall response rate was 78% in arm A (57% CR, 21% PR) and 82% in arm B (60% CR, 22% PR). With a median follow-up time of 47.3 months, the median survival was not reached in arm A, while it was 39.5 months in arm B (P=0.09). Three-year survival rates were 62.5% for CEOP and 51.5% for CNOP. There was no significant difference regarding the time to progression between the two groups (29.7 vs. 18.5 months); furthermore the median duration of CRs was 71.6 and 49 months for CEOP and CNOP, respectively (P=0.07). The therapeutic efficacies of both regimens were equivalent among the four IPI groups. More alopecia was observed in arm A. WHO grade >2 neutropenia was more frequent in arm B. Supportive treatment with G-CSF was given to 22 and 24 patients, respectively. CONCLUSION: There were no significant differences in terms of overall response rates, overall survival and time to progression between CEOP and CNOP in the treatment of intermediate- and high-grade NHL. Patients with low or low intermediate IPI risk treated with either CEOP or CNOP showed significantly better survival, response rates and time to progression than those with high intermediate or high IPI risk. Therefore, new improved therapeutic approaches should be developed for the treatment of high IPI risk patients.     

Breakfast cereal is associated with a lower prevalence of obesity among 10-12-year-old children: the PANACEA study

Background and aimEating behaviours and obesity status among children have already been evaluated in several studies, with conflicting results. The aim of this study is to assess the correlation of breakfast cereal with childhood obesity.Methods and resultsA representative sample of 700 children (323 male) selected from 18 schools located in Athens greater area were enrolled. Children and their parents completed questionnaires that evaluated dietary habits and physical activity. We also retrieved information about the type of breakfast most frequently consumed. Height and weight of the children was measured and body mass index (BMI) was calculated. Simple and multiple logistic regression methods were used in order to determine the relationship between cereal intake for breakfast and obesity.Some boys (8.6%) and girls (9.0%) were obese, whereas 33.9% of boys and 22.1% of girls were overweight. For boys, the adjusted odds ratio for breakfast cereal intake for being overweight or obese was 0.54 (95% confidence interval (CI): 0.45–1.29), while for girls it was 0.41 (95% CI: 0.21–0.79). Moreover, the odds ratio of overweight/obesity for boys who ate daily breakfast was 0.51 (95% CI: 0.25–1.05), and for girls was 0.27 (95% CI: 0.12–0.64), adjusted for physical activity and other potential confounders.ConclusionThese data provide evidence that breakfast cereal as a most frequent choice, and daily consumption of breakfast, are inversely associated with the prevalence of overweight or obesity in 10–12-year-old children.     

Modeling and validating Bayesian accrual models on clinical data and simulations using adaptive priors

Slow recruitment in clinical trials leads to increased costs and resource utilization, which includes both the clinic staff and patient volunteers. Careful planning and monitoring of the accrual process can prevent the unnecessary loss of these resources. We propose two hierarchical extensions to the existing Bayesian constant accrual model: the accelerated prior and the hedging prior. The new proposed priors are able to adaptively utilize the researcher's previous experience and current accrual data to produce the estimation of trial completion time. The performance of these models, including prediction precision, coverage probability, and correct decision‐making ability, is evaluated using actual studies from our cancer center and simulation. The results showed that a constant accrual model with strongly informative priors is very accurate when accrual is on target or slightly off, producing smaller mean squared error, high percentage of coverage, and a high number of correct decisions as to whether or not continue the trial, but it is strongly biased when off target. Flat or weakly informative priors provide protection against an off target prior but are less efficient when the accrual is on target. The accelerated prior performs similar to a strong prior. The hedging prior performs much like the weak priors when the accrual is extremely off target but closer to the strong priors when the accrual is on target or only slightly off target. We suggest improvements in these models and propose new models for future research. Copyright © 2014 John Wiley & Sons, Ltd.