Eine Methode zum Nachweis langsamer Elektronen aus der Anregung und Ionisation von Molekeln durch Elektronenstoß

A new type of secondary negative ions was found in mixtures of “indicator-compounds” such as methyl iodide and sulfur hexafluoride with sulfur dioxide, carbon disulfide, xenon and many other substances. It is shown that the precursors of these secondary ions are free electrons of low kinetic energy which are produced in collisions of fast electrons with gas molecules. For example, sulfur dioxide was found to possess three discrete levels between about 2 and 8 eV which are frequently excited by electrons according to SO2+ e–→ SO2* + e0 –, where the electron e0 – has nearly no kinetic energy and therefore is readily captured by an indicator molecule. Similarly, slow electrons were found to be formed in various excitation and ionization processes (including double and triple ionization) in xenon. This “indicator” method may generally be used to study excitation and ionization processes in which slow electrons are produced.

The relevance of physicochemical and biological parameters for setting emission limit values for plants treating complex industrial wastewaters

The influents of plants treating complex industrial wastewaters from third parties may contain a large variety of often unknown or unidentified potentially harmful substances. The conventional approach of assessing and regulating the effluents of these plants is to set emission limit values for a limited set of physicochemical parameters, such as heavy metals, biological oxygen demand, chemical oxygen demand and adsorbable organic halogen compounds. The objective of this study was to evaluate the relevance of physicochemical parameters for setting emission limit values for such plants based on a comparison of effluent analyses by physicochemical and biological assessment tools. The results show that physicochemical parameters alone are not sufficient to evaluate the effectiveness of the water treatment plants for removing hazardous compounds and to protect the environment. The introduction of toxicity limits and limits for the total bioaccumulation potential should be considered to supplement generic parameters such as chemical oxygen demand and adsorbable organic halogens. A recommendation is made to include toxicity screening as a technique to consider in the determination of best available techniques (BAT) during the upcoming revision of the BAT reference document for the waste treatment industries to provide a more rational basis in decisions on additional treatment steps.

Development and evaluation of a short 24-h food list as part of a blended dietary assessment strategy in large-scale cohort studies

BACKGROUND/OBJECTIVES

The validity of dietary assessment in large-scale cohort studies has been questioned. Combining data sources for the estimation of usual intake in a blended approach may enhance the validity of dietary measurement. Our objective was to develop a web-based 24-h food list for Germany to identify foods consumed during the previous 24 h and to evaluate the performance of the new questionnaire in a feasibility study.

SUBJECTS/METHODS

Available data from the German National Nutrition Survey II were used to develop a finite list of food items. A total of 508 individuals were invited to fill in the 24-h food list via the Internet up to three times during a 3-6-month time period. In addition, participants were asked to evaluate the questionnaire using a brief online evaluation form.

RESULTS

In total, 246 food items were identified for the 24-h food list, reflecting >75% variation in intake of 27 nutrients and four major food groups. Among the individuals invited, 64% participated in the feasibility study. Of these, 100%, 85% and 68% of participants completed the 24-h food list one, two or three times, respectively. The average time needed to complete the questionnaire was 9 min, and its acceptability by participants was rated as high.

CONCLUSIONS

The 24-h food list represents a promising new dietary assessment tool that can be used as part of a blended approach combining multiple data sources for valid estimation of usual dietary intake in large-scale cohort studies.

TRPM4

TRPM4 is a Ca(2+)-activated nonselective cation channel. The channel is activated by an increase of intracellular Ca(2+) and is regulated by several factors including temperature and Pi(4,5)P2. TRPM4 allows Na(+) entry into the cell upon activation, but is completely impermeable to Ca(2+). Unlike TRPM5, its closest relative in the transient receptor potential family, TRPM4 proteins are widely expressed in the body. Currents with properties that are reminiscent of TRPM4 have been described in a variety of tissues since the advent of the patch clamp technology, but their physiological role is only beginning to be clarified with the increasing characterization of knockout mouse models for TRPM4. Furthermore, mutations in the TRPM4 gene have been associated with cardiac conduction disorders in human patients. This review aims to overview the currently available data on the functional properties of TRPM4 and the current understanding of its physiological role in healthy and diseased tissue.

Comparison of methods for quantification of global DNA methylation in human cells and tissues

DNA methylation is a key epigenetic modification which, in mammals, occurs mainly at CpG dinucleotides. Most of the CpG methylation in the genome is found in repetitive regions, rich in dormant transposons and endogenous retroviruses. Global DNA hypomethylation, which is a common feature of several conditions such as ageing and cancer, can cause the undesirable activation of dormant repeat elements and lead to altered expression of associated genes. DNA hypomethylation can cause genomic instability and may contribute to mutations and chromosomal recombinations. Various approaches for quantification of global DNA methylation are widely used. Several of these approaches measure a surrogate for total genomic methyl cytosine and there is uncertainty about the comparability of these methods. Here we have applied 3 different approaches (luminometric methylation assay, pyrosequencing of the methylation status of the Alu repeat element and of the LINE1 repeat element) for estimating global DNA methylation in the same human cell and tissue samples and have compared these estimates with the "gold standard" of methyl cytosine quantification by HPLC. Next to HPLC, the LINE1 approach shows the smallest variation between samples, followed by Alu. Pearson correlations and Bland-Altman analyses confirmed that global DNA methylation estimates obtained via the LINE1 approach corresponded best with HPLC-based measurements. Although, we did not find compelling evidence that the gold standard measurement by HPLC could be substituted with confidence by any of the surrogate assays for detecting global DNA methylation investigated here, the LINE1 assay seems likely to be an acceptable surrogate in many cases.

Increased β-adrenergic inotropy in ventricular myocardium from Trpm4-/- mice

RATIONALE

The Trpm4 gene has recently been associated with several disorders, including cardiac conduction diseases and Brugada syndrome. Transient receptor potential member 4 (TRPM4) proteins constitute Ca2+ -activated, but Ca2+ -impermeable, nonselective cation channels and are expressed both in atrial and in ventricular cardiomyocytes. The physiological function of TRPM4 in the heart remains, however, incompletely understood.

OBJECTIVE

To establish the role of TRPM4 in cardiac muscle function.

METHODS AND RESULTS

We used TRPM4 knockout mice and performed patch-clamp experiments, membrane potential measurements, microfluorometry, contractility measurements, and in vivo pressure-volume loop analysis. We demonstrate that TRPM4 proteins are functionally present in mouse ventricular myocytes and are activated on Ca2+ -induced Ca2+ release. In Trpm4(-/-) mice, cardiac muscle displays an increased β-adrenergic inotropic response both in vitro and in vivo. Measurements of action potential duration show a significantly decreased time for 50% and 90% repolarization in Trpm4(-/-) ventricular myocytes. We provide evidence that this change in action potential shape leads to an increased driving force for the L-type Ca2+ current during the action potential, which explains the altered contractility of the heart muscle.

CONCLUSIONS

Our results show that functional TRPM4 proteins are novel determinants of the inotropic effect of β-adrenergic stimulation on the ventricular heart muscle.

Influence of ambient air pollution on global DNA methylation in healthy adults: a seasonal follow-up

BACKGROUND

DNA methylation changes are potential pathways of environmentally induced health effects. We investigated whether exposure to ambient concentrations of NO2, PM10, PM2.5 and O3 and traffic parameters were associated with global DNA methylation in blood of healthy adults.

METHODS

48 non-smoking adults (25 males) with a median age of 39years were sampled in winter and summer. Global DNA methylation in whole blood (% 5-methyl-2'-deoxycytidine, %5mdC) was analyzed with HPLC. Exposure to air pollutants at the home address was assessed using interpolated NO2, PM10, PM2.5 and O3 concentrations for various exposure windows (60- to 1-day moving average exposures and yearly averages) and GIS-based traffic parameters. Associations between pollutants and %5mdC were tested with multiple mixed effects regression models.

RESULTS

Average %5mdC (SD) was 4.30 (0.08) in winter and 4.29 (0.08) in summer. Men had higher %5mdC compared to women both in winter (4.32 vs. 4.26) and summer (4.31 vs. 4.27). When winter and summer data were analyzed together, various NO2, PM10 and PM2.5 moving average exposures were associated with changes in %5mdC (95% CI) ranging from -0.04 (-0.09 to 0.00) to -0.14 (-0.28 to 0.00) per IQR increase in pollutant. NO2, PM10, PM2.5 and O3 moving average exposures were associated with decreased %5mdC (95% CI) varying between -0.01 (-0.03 to 0.00) and -0.17 (-0.27 to -0.06) per IQR increase in pollutant in summer but not in winter.

CONCLUSION

Decreased global DNA methylation in whole blood was associated with exposure to NO2, PM10, PM2.5 and O3 at the home addresses of non- adults. Most effects were observed for the 5- to 30-day moving average exposures.

Double-blind, controlled phase II study of a 5-HT6 receptor antagonist, SB-742457, in Alzheimer's disease

BACKGROUND

This randomized, double-blind, placebo-controlled study investigated the efficacy and tolerability of the 5-HT6 receptor antagonist, SB-742457, in subjects with mild-to-moderate probable Alzheimer's disease (AD).

METHODS

Participating subjects had a Mini-Mental State Examination (MMSE) score of 12 to 26 after a 4-week, single-blind, placebo run-in phase, and were randomized (2:1:1:2) to receive placebo, SB-742457 5 mg, 15 mg, or 35 mg once daily for 24 weeks. Coprimary efficacy endpoints were the Clinician's Interview-Based Impression of Change with caregiver input (CIBIC+) score and change from baseline in Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) score at Week 24, in the intent-to-treat (ITT) population. A model-based design provided 90% power to detect a linear trend in treatment response across increasing doses and > or =90% power to compare SB-742457 35 mg with placebo.

RESULTS

371 subjects were randomized. In the ITT population (n=357), linear trend analysis at Week 24 suggested a dose response for CIBIC+ with a mean slope of -0.05 points/5-mg dose increase (95% confidence interval [CI]: -0.09, -0.01; p=0.016). The dose response slope for change from baseline in ADAS-Cog was -0.22 points/5-mg dose increase (95% CI: -0.45, 0.01; p=0.059). The adjusted mean treatment difference from placebo at Week 24 for SB-742457 35 mg (-0.31) was significant on CIBIC+ (95% CI: -0.62, -0.00; p=0.047) but non-significant on ADAS-Cog (-1.28 [95% CI: -2.96, 0.40]; p=0.135). Adverse events occurred in 24-37% in the SB-742457 groups vs 29% for placebo; 11-16% discontinued SB-742457 vs 15% for placebo.

COMMENTS

SB-742457 was generally safe and well tolerated and may be efficacious in AD.

Association of inflammatory bowel disease risk loci with sarcoidosis, and its acute and chronic subphenotypes

Sarcoidosis is a complex granulomatous inflammatory disorder that shares several clinical and pathogenic features with inflammatory bowel disease (IBD). Postulating a common genetic basis of inflammatory diseases, we tested 106 single-nucleotide polymorphisms (SNPs) that are known or have been suggested to be associated with IBD for a potential association with sarcoidosis and its acute and chronic subphenotypes. We genotyped 1,996 German sarcoidosis patients, comprising 648 acutely and 1,161 chronically affected individuals, 2,622 control subjects, and 342 German trios with affected offspring using SNPlex™ technology. The nonsynonymous SNP rs11209026 (Arg381Gln) in the interleukin (IL)-23 receptor (IL23R) gene was associated with chronic sarcoidosis (OR 0.63; p = 5.58×10(-5)), which was supported by the result of a transmission disequilibrium test analysis in the independent family sample (OR 0.50; p = 0.031). Marker rs12035082 located at chromosome 1q24.3 was found to be associated with the acute subphenotype (OR 1.36; p = 6.80×10(-7)) and rs916977 (HERC2 locus; OR 1.30; p = 4.49×10(-5)) was associated with sarcoidosis. Our results highlight the potential importance of the IL-23 signalling pathway for the development of chronic sarcoidosis. The finding links sarcoidosis pathogenesis to other inflammatory conditions and may contribute to new hypotheses on disease mechanisms.

NOD-like receptors: ancient sentinels of the innate immune system

NOD-like receptors (NLRs) comprise a family of cytosolic proteins that have been implicated as ancient cellular sentinels mediating protective immune responses elicited by intracellular pathogens or endogenous danger signals. Genetic variants in NLR genes have been associated with complex chronic inflammatory barrier diseases (e.g. Crohn disease, bronchial asthma). In this review, we focus on the molecular pathophysiology of NLRs in the context of chronic inflammatory diseases and pinpoint recent advances in the evolutionary understanding of NLR biology. We propose that the field of NLRs may serve as a prototype for how a comprehensive understanding of an element of the immunological barrier will eventually lead to the development of targeted diagnostic, therapeutic and/or preventive strategies.

Prognostic factors (PF) in advanced hepatocellular carcinoma (AHCC): Multivariate analysis and comparison between staging systems (SS) in patients (pts) treated at Memorial Sloan-Kettering Cancer Center (MSKCC)

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Background: Several SS have been proposed in hepatocellular carcinoma. These include TNM, Okuda, Cancer of the Liver Italian Program (CLIP), Chinese University Prognostic Index (CUPI), and Barcelona Clinic Liver Cancer (BCLC). There is no consensus as to what constitutes the best SS for use by oncologists for pts with AHCC with no locoregional therapy options. We propose to define the PF and compare SS in this patient population. SS may help select pts for systemic therapy, predict outcome, and help in clinical trial design for AHCC. Methods: We retrospectively identified pts with AHCC treated at MSKCC between 2001 and 2006. Clinical, laboratory, tumor characteristics and all four SS were recorded. Survival (S) was measured from the date of development of AHCC to the date of death. S was estimated using Kaplan-Meier’s method, differences in S were tested using the log rank test. A Cox regression model was used for the multivariate analysis. A second Cox regression was done to compare SS and was expressed using the Akaike information (AI) criterion. AI helps determine which SS is the most informative of S. A low AI is favorable. Results: We identified 280 pts. Data on the first 101 pts analyzed are presented. Median age 61 years; 71% males, 29% females; 60% Caucasians, 9% Black, 24% Asians and 5% Hispanics. Etiologies included HCV 24%, HBV 38%, and alcohol 22%. Child Pugh score: A in 65% and B in 29% of pts. Multivariate analysis independent PF for S were albumin (p=0.0358), alkaline phosphatase (ALP) (p=0.001), identified etiology (p=0.008), abdominal pain (p=0.001) and liver tumor extent (more or less than 50% of the liver) (p=0.0043). AI ranked SS as follows: TNM 6th (588.991), TNM 5th (591.373), BCLC (541.095), Okuda (540.490), CLIP (537.8), and CUPI (526.483). CUPI S was 19.47 months (m) for low, 5.89 m for medium, and 1.36 m for high risk pts. Conclusions: Pts with AHCC who are treated by oncologists in this US-based population have distinct PF. CUPI provided the best prognostic information for our patient population. CUPI may be suggested as the SS to use clinically for AHCC. These results need prospective validation.

No significant financial relationships to disclose.