Human dendritic cell responses to lipopolysaccharide and CD40 ligation are differentially regulated by interleukin-10

We evaluated the effects of interleukin (IL)-10 on the maturation of human dendritic cells (DC) induced either by lipopolysaccharide (LPS) or CD40 engagement. For this purpose, DC generated by culturing plastic-adherent peripheral blood mononuclear cells for 7 days with granulocyte/macrophage-colony-stimulating factor and IL-4 were incubated for 3 days with either LPS (10 ng/ml) or 3T6 fibroblasts transfected with the gene encoding CD40 ligand, in absence or presence of IL-10. First we found that the membrane expression of CD83, a marker of mature DC, was inhibited by IL-10 when induced by LPS but not by CD40 engagement. Likewise, IL-10 inhibited LPS-induced but not CD40-dependent CD86 (B7.2) up-regulation on DC. Furthermore, IL-10 inhibited the production of IL-8 and tumor necrosis factor-α by DC when activated by LPS but not by CD40. In contrast, IL-10 inhibited IL-12 production in both activation systems. We conclude that IL-10 differentially influences LPS-dependent and CD40-dependent pathways of DC maturation.     

Effects of Antidepressants on G Protein-coupled Receptor Signaling and Viability in Xenopus laevis Oocytes

Background: Tricyclic antidepressants are structurally related to local anesthetics, suggesting that part of their analgesic action may result from properties shared with local anesthetics. Because local anesthetics block G protein-coupled receptor signaling (which explains, in part, their inflammatory modulating properties), the authors studied whether antidepressants have similar effects.

Methods: Peak Ca-activated Cl currents induced in Xenopus laevis oocytes by lysophosphatidic acid (10-4 m) were measured using a voltage clamp. The effects of a 30-, 120-, or 240-min incubation in amitriptyline, nortriptyline, imipramine, or fluoxetine were determined.

Results: After a 30-min incubation, low concentrations (10-7-10-5 m) of antidepressants had no effect on lysophosphatidic acid-induced currents. After prolonged incubation, only amitriptyline or nortriptyline inhibited lysophosphatidic acid signaling (each to 58% of the control response at 10-7 m after 240 min). At low concentrations, none of the compounds induced membrane damage (defined as a holding current of > 1 [mu]A, 2% in control cells). Imipramine at 10-3 m induced damage in 100% of oocytes, and fluoxetine at 10-4 m induced damage in 71% of oocytes (P < 0.05 vs. control). Amitriptyline and nortriptyline had no effect.     

Synthesis of Potential Impurities of Cefalexin and Cefradine

The synthesis of some impurities of the cephalosporin antibiotics cefalexin and cefradine is described. These impurities which may be present in commercial samples are formed during the semi-synthetic preparation of these antibiotics or upon their degradation. The preparation of these compounds enables the validation of selective quantitative analytical methods, such as column liquid chromatography and thin layer chromatography.     

Microsatellite instability in pediatric and adult high-grade gliomas

About 15% of sporadic gastrointestinal and endometrial tumors show the microsatellite instability (MSI) phenotype because of loss of DNA mismatch repair (MMR) function. The incidence of MSI in tumors of the central nervous system still remains controversial. Previous studies reported a particular high frequency of MSI (approximately 25%) in young patients suffering from high-grade gliomas. Based on these data and the fact that in different tumor entities MMR deficiency defines a subgroup of tumors with distinct pathogenesis and particular clinicopathological features that may have impact on prognosis and therapy, we screened 624 gliomas from 71 young and 553 adult patients for MMR deficiency by MSI analysis using three highly sensitive diagnostic markers. Alterations of MMR protein expression was examined by immunohistochemistry. A malignant glioma from an adult patient displayed MSI and concomitant loss of nuclear MSH2 and MSH6 protein expression (0.16%; 1/619). No evidence for MSI or loss of MMR protein expression was observed in 71 gliomas from young patients (0%; 0/71) including 41 high-grade astrocytic tumors. Overall, we observed a much lower incidence of MSI among high-grade pediatric gliomas than initially reported and suggest that MMR deficiency does not play a major role in the pathogenesis of glial neoplasms.     

Application of the biotic ligand model to explain potassium interaction with thallium uptake and toxicity to plankton

Abstract-Competitive interaction between TI(I) and K was successfully predicted by the biotic ligand model (BLM) for the microalga Chlorella sp. (Chlorophyta; University of Toronto Culture Collection strain 522) during 96-h toxicity tests. Because of a greater affinity of T1(I) (log K = 7.3-7.4) as compared to K (log K = 5.3-6.3) for biologically sensitive sites, an excess of 40- to 160-fold of K is required to suppress T1(I) toxic effects on Chlorella sp., regardless of [T1(I)] in solution. Similar excess of K is required to suppress T1(I) toxicity to Synechococcus leopoliensis (Cyanobacteria; University of Texas Culture Collection strain 625) and Brachionus calyciflorus (Rotifera; strain AB-RIF). The mechanism for the mitigating effect of K on T1(I) toxicity was investigated by measuring 204T1(I) cellular uptake flux and efflux in Chlorella sp. Potassium shows a competitive effect on T1(I) uptake fluxes that could be modeled using the BLM-derived stability constants and a Michaelis-Menten relationship. A strong T1 efflux dependent only on the cellular T1 concentration was measured. Although T1 efflux does not explain the effect of K on T1(I) toxicity and uptake, it is responsible for a high turnover of the cellular T1 pool (intracellular half-life = 12-13.5 min). No effect of Na+, Mg2+, or Ca2+ was observed on T1+ uptake, whereas the absence of trace metals (Cu, Co, Mo, Mn, Fe, and Zn) significantly increased T1 uptake and decreased the mitigating effect of K+. The importance of K+ in determining the aquatic toxicity of T1+ underscores the use of ambient K+ concentration in the establishment of T1 water-quality guidelines and the need to consider K in predicting biogeochemical fates of T1 in the aquatic environment.     

Cost-effectiveness analysis in colorectal cancer using a semi-Markov model

Cost and effectiveness are usually modeled according to one studied event or one health state with parametric or non-parametric methods. In this paper, we propose an original method for assessing total costs while incorporating the dynamics of change in the health status of patients. A semi-Markov model in which the distributions of sojourn times are explicitly defined is developed. The hazard function of sojourn times is modeled by Weibull distributions specific to each transition. A vector of covariates is incorporated into the hazard function of each transition. From a regression model for costs, a cumulative cost function is derived. An estimation of the mean cost per patient in each state defined in the semi-Markov model could thus be made, and this enables us to identify the determinants of direct costs. The results of incremental net benefit (INB) are assessed using the bootstrap method. A cost-effectiveness analysis is performed in order to compare two strategies of follow-up in the colorectal cancer study. Two hundred and forty patients were enrolled in this study. Three health states are defined for patients with curative resection of colorectal cancer: alive without relapse, alive with relapse, and dead. The mean survival is 4.35 and 4.12 years, respectively, in the standard and moderate follow-up groups. We show that mean cost differs significantly by follow-up strategy and Dukes stage. Finally, the INB is assessed and this indicates that neither of the strategies compared was more cost-effective than the other.     

Validation of psychomotor tasks by Simbionix LAP Mentor simulator and identifying the target group

Background: This study addresses target group reliability and task validity for training on a laparoscopic simulator.

Material and methods: Data were collected on 64 participants prospectively at the Department of OB/GYN, University Hospitals Schleswig-Holstein, Campus Kiel. The Simbionix LAP Mentor for laparoscopic simulation was used to test trainees. Each participant received a questionnaire to clarify his/her medical position, surgical experience, and previous virtual reality (VR) experience, including video gaming experience. Pre- and post-tests were performed. Performances were analyzed for task completion and total time.

Results: All participants revealed a significant improvement in the post-test compared with the pre-test (p?Conclusion: The trainer could be beneficial for medical students and surgical novices.     

A Polyprotein-Expressing Salmonid Alphavirus Replicon Induces Modest Protection in Atlantic Salmon (Salmo Salar) Against Infectious Pancreatic Necrosis

Vaccination is an important strategy for the control and prevention of infectious pancreatic necrosis (IPN) in farmed Atlantic salmon (Salmo salar) in the post-smolt stage in sea-water. In this study, a heterologous gene expression system, based on a replicon construct of salmonid alphavirus (SAV), was used for in vitro and in vivo expression of IPN virus proteins. The large open reading frame of segment A, encoding the polyprotein NH2-pVP2-VP4-VP3-COOH, as well as pVP2, were cloned and expressed by the SAV replicon in Chinook salmon embryo cells (CHSE-214) and epithelioma papulosum cyprini (EPC) cells. The replicon constructs pSAV/polyprotein (pSAV/PP) and pSAV/pVP2 were used to immunize Atlantic salmon (Salmo salar) by a single intramuscular injection and tested in a subsequent IPN virus (IPNV) challenge trial. A low to moderate protection against IPN was observed in fish immunized with the replicon vaccine that encoded the pSAV/PP, while the pSAV/pVP2 construct was not found to induce protection.