[Septic Shock in Pyogenic Liver Abscess: Clinical Considerations].

BACKGROUND/AIMS: Pyogenic liver abscess (PLA) is a life-threatening condition, despite advances in diagnostic technology and strategies for treatment. A strong predictor of mortality in this condition is septic shock. This study describes clinical, biochemical, and radiologic features in patients with PLA with or without septic shock, with the intent of describing risk factors for septic shock. METHODS: Of 358 patients with PLA enrolled, 30 suffered septic shock and the remaining 328 did not. We reviewed the medical records including etiologies, underlying diseases, laboratory, radiologic and microbiologic findings, methods of treatment and treatment outcomes. RESULTS: The case fatality rate was 6.1%. In univariate analysis, the presence of general weakness, mental change, low platelet level, prolonged PT, high BUN level, high creatinine level, low albumin level, high AST level, high CRP level, abscess size >6 cm, the presence of gas-forming abscess, APACHE II score ≥ 20, and the presence of Klebsiella pneumoniae infection were significantly associated with septic shock. Multivariate analysis showed the presence of mental change (p=0.004), gas-form -ing abscess (p=0.012), and K. pneumoniae infection (p=0.027) were independent predictors for septic shock. CONCLUSIONS: The presence of mental change, gas-forming abscess, and K. pneumoniae infection were independent predictors for septic shock in patients with PLA.

Cancer cell growth inhibitory effect of bee venom via increase of death receptor 3 expression and inactivation of NF-kappa B in NSCLC cells.

Our previous findings have demonstrated that bee venom (BV) has anti-cancer activity in several cancer cells. However, the effects of BV on lung cancer cell growth have not been reported. Cell viability was determined with trypan blue uptake, soft agar formation as well as DAPI and TUNEL assay. Cell death related protein expression was determined with Western blotting. An EMSA was used for nuclear factor kappaB (NF-κB) activity assay. BV (1-5 µg/mL) inhibited growth of lung cancer cells by induction of apoptosis in a dose dependent manner in lung cancer cell lines A549 and NCI-H460. Consistent with apoptotic cell death, expression of DR3 and DR6 was significantly increased. However, deletion of DRs by small interfering RNA significantly reversed BV induced cell growth inhibitory effects. Expression of pro-apoptotic proteins (caspase-3 and Bax) was concomitantly increased, but the NF-κB activity and expression of Bcl-2 were inhibited. A combination treatment of tumor necrosis factor (TNF)-like weak inducer of apoptosis, TNF-related apoptosis-inducing ligand, docetaxel and cisplatin, with BV synergistically inhibited both A549 and NCI-H460 lung cancer cell growth with further down regulation of NF-κB activity. These results show that BV induces apoptotic cell death in lung cancer cells through the enhancement of DR3 expression and inhibition of NF-κB pathway.

[Clinical features of pyogenic liver abscess according to age group].

BACKGROUND/AIMS: Pyogenic liver abscess remains a major diagnostic and therapeutic challenge, despite advances in diagnostic technology and new strategies for treatment. This study was conducted to compare the differences in clinical features and outcomes of pyogenic liver abscess according to age. METHODS: In total, 166 patients were enrolled and included 63 (<65 years old, group I), 62 (65-74 years old, group II), 41 (>75 years old, group III) patients in each group. We reviewed the medical records retrospectively including etiology, underlying diseases, characteristics of the liver abscess, laboratory and microbiologic findings, treatment, and outcome of the patients. RESULTS: Group I had higher prevalence rates of male patients and chronic alcoholics, but lower prevalence rates of biliary disease, hypertension, and malignancy. In laboratory findings, group II had higher incidence of thrombocytopenia, elevated blood urea nitrogen and creatinine. There were no differences in symptoms and microbiologic findings in blood and pus among the three groups. Liver abscesses were more common in right liver in Group I. The lengths of stay and the treatment modalities were similar in three groups. CONCLUSIONS: Although there were differences in sex ratio, etiology, underlying disease among the different age groups, they did not cause difference in treatment and clinical outcome of pyogenic liver abscess. Thus, we recommend active treatments in patients of all age.

Redox-sensitivity and site-specificity of S- and N- denitrosation in proteins.

BACKGROUND: S-nitrosation--the formation of S-nitrosothiols (RSNOs) at cysteine residues in proteins--is a posttranslational modification involved in signal transduction and nitric oxide (NO) transport. Recent studies would also suggest the formation of N-nitrosamines (RNNOs) in proteins in vivo, although their biological significance remains obscure. In this study, we characterized a redox-based mechanism by which N-nitroso-tryptophan residues in proteins may be denitrosated. METHODOLOGY/PRINCIPAL FINDINGS: The denitrosation of N-acetyl-nitroso Trp (NANT) by glutathione (GSH) required molecular oxygen and was inhibited by superoxide dismutase (SOD). Transnitrosation to form S-nitrosoglutathione (GSNO) was observed only in the absence of oxygen or presence of SOD. Protein denitrosation by GSH was studied using a set of mutant recombinant human serum albumin (HSA). Trp-214 and Cys-37 were the only two residues nitrosated by NO under aerobic conditions. Nitroso-Trp-214 in HSA was insensitive to denitrosation by GSH or ascorbate while denitrosation at Cys-37 was evident in the presence of GSH but not ascorbate. GSH-dependent denitrosation of Trp-214 was restored in a peptide fragment of helix II containing Trp-214. Finally, incubation of cell lysates with NANT revealed a pattern of protein nitrosation distinct from that observed with GSNO. CONCLUSIONS: We propose that the denitrosation of nitrosated Trp by GSH occurs through homolytic cleavage of nitroso Trp to NO and a Trp aminyl radical, driven by the formation of superoxide derived from the oxidation of GSH to GSSG. Overall, the accessibility of Trp residues to redox-active biomolecules determines the stability of protein-associated nitroso species such that in the case of HSA, N-nitroso-Trp-214 is insensitive to denitrosation by low-molecular-weight antioxidants. Moreover, RNNOs can generate free NO and transfer their NO moiety in an oxygen-dependent fashion, albeit site-specificities appear to differ markedly from that of RSNOs.

Modeling and kinetic analysis of the reaction system using whole cells with separately and co-expressed D-hydantoinase and N-carbamoylase.

We developed a kinetic model that describes a heterogeneous reaction system for the production of D-p-hydroxyphenylglycine from D,L-p-hydroxyphenyl-hydantoin using D-hydantoinase of Bacillus stearothermophilus SD1 and N-carbamoylase of Agrobacterium tumefaciens NRRL B11291. As a biocatalyst, whole cells with separately or co-expressed enzymes were used. The reaction system involves dissolution of substrate particles, enzymatic conversion, racemization of the L-form substrate, and transfer of the dissolved substrate, intermediate, and product through the cell membrane. Because the two enzymes have different pH optimum, kinetic parameters were evaluated at different pH for the reaction systems. The model was simulated using the kinetic parameters and compared with experimental data, and it was found that the kinetic model well describes the behavior of the reaction systems using whole cells with separately and co-expressed enzymes. Factors affecting the kinetics of the reaction systems were analyzed on the basis of the kinetic model. In the reaction system with separately expressed enzymes, racemization rate and transport of the reaction intermediate (N-carbamoyl-D-p-hydroxyphenylglycine) were revealed to be the limiting factors at neutral pH, resulting in accumulation of intermediate in the reaction medium. At alkaline condition, on the other hand, inhibition of N-carbamoylase by ammonia was severe, and thereby the reaction rate significantly reduced. In the co-expressed enzyme system, accumulation of intermediate was negligible in the reaction medium, and the improved performance was observed compared to that with separately expressed enzymes. The present model might be applied for the optimization and development of the reaction system using two sequential enzymes.