Coronary patients with high plasma omentin are at a higher cardiovascular risk.

The adipokine omentin, also known as intelectin, is a secretory protein, expressed in visceral adipose tissue and is highly abundant in plasma. It is involved in the development of chronic inflammatory diseases, but nothing is known about its impact on the cardiovascular event risk. Here, plasma omentin was measured in 295 patients undergoing coronary angiography for the evaluation of established or suspected stable coronary artery disease (CAD). Patients were separated according to the median plasma omentin concentrations into a high and low omentin group and cardiovascular events occurring during a period of 3.5 years have been recorded. We observed that patients within the high omentin group had significantly more cardiovascular events than patients in the low omentin group. This was true even if using different study endpoints. This article describes data related to a research article titled "High Plasma Omentin Predicts Cardiovascular Events Independently From the Presence and Extent of Angiographically Determined Atherosclerosis" (Saely et al., 2015) [1].

High plasma chemerin is associated with renal dysfunction and predictive for cardiovascular events - Insights from phenotype and genotype characterization.

The novel adipokine chemerin, encoded by the RARRES2 gene, has been suggested to be linked to insulin resistance and to the metabolic syndrome (MetS). However, no well-defined cardiovascular profile has been reported and the association with coronary artery disease (CAD) is a matter of debate. Because there is a relation between renal dysfunction and CAD, we analyzed plasma chemerin levels and the estimated glomerular filtration rate (eGFR) in 495 patients undergoing coronary angiography for the evaluation of established or suspected stable CAD. Chemerin levels were higher in patients with Type 2 diabetes mellitus (T2DM, n=111) and the metabolic syndrome (MetS, n=147) than in subjects without T2DM (191.5±72.9 vs. 169.7±64.7ng/ml, p=0.001) or the MetS (201.2±71.0 vs. 163,1ng/ml, p<0.001), but did not differ significantly between patients with significant CAD (n=247) and those without significant CAD (177.1±67.0 vs. 171.7±67.2ng/ml, p=0.193). Analysis of covariance using age, sex, and BMI as covariates showed that chemerin was significantly and independently associated with eGFR (F=49.6, p<0.001). After an 8-year follow-up period, patients with high chemerin levels were more often affected by cardiovascular events (HR=1.72 [95% CI 1.19-2.47], p=0.004), even after appropriate adjustment for age, gender, BMI, as well as eGFR (adjusted HR 1.51 [95% CI 1.03-2.23], p=0.037). Given the cardiometabolic role of chemerin, we also applied a Cardio-Metabo Chip analysis and revealed a genome-wide significant association with SNPs (rs55709438, rs2444030, and rs3098423) located at chromosomal region 15q15-23, which were associated with metabolic traits and eGFR. This study for the first time demonstrates that high chemerin concentrations are significantly associated with renal impairment and predictive of cardiovascular events and that 15q15-23 might have an impact on chemerin levels beyond common genetic variations in RARRES2.

High plasma omentin predicts cardiovascular events independently from the presence and extent of angiographically determined atherosclerosis.

BACKGROUND AND AIMS: No prospective data on the power of the adipocytokine omentin to predict cardiovascular events are available. We aimed at investigating i) the association of plasma omentin with cardiometabolic risk markers, ii) its association with angiographically determined coronary atherosclerosis, and iii) its power to predict cardiovascular events. METHODS: We measured plasma omentin in 295 patients undergoing coronary angiography for the evaluation of established or suspected stable coronary artery disease (CAD), of whom 161 had significant CAD with coronary artery stenoses ≥50% and 134 did not have significant CAD. RESULTS: Over 3.5 years, 17.6% of our patients suffered cardiovascular events, corresponding to an annual event rate of 5.0%. At baseline, plasma omentin was not significantly associated with metabolic syndrome stigmata and did not differ significantly between patients with and subjects without significant CAD (17.2 ± 13.6 ng/ml vs. 17.5 ± 15.1 ng/ml; p = 0.783). Prospectively, however, cardiovascular event risk significantly increased over tertiles of omentin (12.1%, 13.8%, and 29.5%, for tertiles 1 through 3; ptrend = 0.003), and omentin as a continuous variable significantly predicted cardiovascular events after adjustment for age, gender, BMI, diabetes, hypertension, LDL cholesterol, HDL cholesterol, and smoking (standardized adjusted hazard ratio (HR) 1.41 [95% CI 1.16-1.72]; p < 0.001), as well as after additional adjustment for the presence and extent of significant CAD at baseline (HR 1.59 [95% CI 1.29-1.97, p < 0.001). CONCLUSION: From this first prospective evaluation of the cardiovascular risk associated with omentin we conclude that elevated plasma omentin significantly predicts cardiovascular events independently from the presence and extent of angiographically determined baseline CAD.

Angiopoietin-like protein 4 significantly predicts future cardiovascular events in coronary patients.

BACKGROUND: Angiopoietin-like protein 4 (ANGPTL4) has been associated with cardiometabolic disorders including dyslipidemia and atherosclerosis in animal studies; in humans, however, its impact on metabolic traits and cardiovascular risk remains unclear. METHODS: We examined the association of plasma ANGPTL4 levels with the metabolic syndrome (harmonized consensus definition), with angiographically determined coronary artery disease (CAD), and with the risk of future cardiovascular events in a cohort of 490 patients undergoing coronary angiography for the evaluation of stable CAD. In addition, we investigated the influence of the tagging single nucleotide polymorphisms (SNPs) rs4076317, rs2278236, rs1044250, and rs11672433 as well as variant rs116843064 (E40K) of the ANGPTL4 gene on cardiovascular risk in a larger sample of 983 angiographied coronary patients including the above mentioned 490 subjects. RESULTS: Plasma ANGPTL4 was significantly higher in patients with the metabolic syndrome than in subjects without the metabolic syndrome (26.0 ± 19.4 ng/ml vs. 22.2 ± 19.7 ng/ml; p = 0.008). No significant association was found between ANGPTL4 and angiographically characterized coronary atherosclerosis. Prospectively, however, plasma ANGPTL4 significantly predicted future cardiovascular events both univariately (HR1.45 [1.16-1.82], p = 0.001) and after adjustment for standard cardiovascular risk factors (1.26 [1.01-1.58]; p = 0.045). Concordantly, rs4076317, rs2278236, and rs1044250 significantly affected the risk of future cardiovascular events (adjusted HRs 0.70 [0.54-0.90]; p = 0.005, 0.76 [0.61-0.94]; p = 0.012, and 1.30 [1.03-1.62]; p = 0.025, respectively). CONCLUSIONS: We conclude that plasma ANGPTL4 levels as well as ANGPTL4 variants significantly predict cardiovascular events independently of conventional cardiovascular risk factors.

Reactor performance of a 750 m(3) anaerobic digestion plant: varied substrate input conditions impacting methanogenic community.

A 750 m(3) anaerobic digester was studied over a half year period including a shift from good reactor performance to a reduced one. Various abiotic parameters like volatile fatty acids (VFA) (formic-, acetic-, propionic-, (iso-)butyric-, (iso-)valeric-, lactic acid), total C, total N, NH4 -N, and total proteins, as well as the organic matter content and dry mass were determined. In addition several process parameters such as temperature, pH, retention time and input of substrate and the concentrations of CH4, H2, CO2 and H2S within the reactor were monitored continuously. The present study aimed at the investigation of the abundance of acetogens and total cell numbers and the microbial methanogenic community as derived from PCR-dHPLC analysis in order to put it into context with the determined abiotic parameters. An influence of substrate quantity on the efficiency of the anaerobic digestion process was found as well as a shift from a hydrogenotrophic in times of good reactor performance towards an acetoclastic dominated methanogenic community in times of reduced reactor performance. After the change in substrate conditions it took the methano-archaeal community about 5-6 weeks to be affected but then changes occurred quickly.

Impact of protein-, lipid- and cellulose-containing complex substrates on biogas production and microbial communities in batch experiments.

In the present study, nine complex organic substrates from three classes (protein-, lipid-, and cellulose-rich) were investigated in batch experiments and compared with a control in order to evaluate their potential for utilisation as substrates for biogas production. High methane production was observed from protein-rich substrates; problems arose from lipid-containing, lactose and cellulose fermentation. Using DGGE analysis it could be shown that different classes of substrate resulted in different microbial communities, whereupon similar substrates tended to show a similar microbial structure. By means of qPCR Methanoculleus sp., a hydrogenotrophic methanogen was found to be the most abundant organism in the batch experiments. Additionally, it could be demonstrated that methanogenic organisms withstood adverse environmental conditions for at least an incubation period of 55 days, pointing to a high stability of the archaeal community even in times of decreasing or even failing fermenter performance.

Effects of various fatty acid amendments on a microbial digester community in batch culture.

Since biogas production is becoming increasingly important the understanding of anaerobic digestion processes is fundamental. However, large-scale digesters often lack online sensor equipment to monitor key parameters. Furthermore the possibility to selectively change fermenting parameter settings in order to investigate methane output or microbial changes is limited. In the present study we examined the possibility to investigate the microbial community of a large scale (750,000 L) digester within a laboratory small-scale approach. We studied the short-term response of the downscaled communities on various fatty acids and its effects on gas production and compared it with data from the original digester sludge. Even high loads of formic acid led to distinct methane formation, whereas high concentrations of other acids (acetic, butyric, propionic acid) caused a marked inhibition of methanogenesis coupled with an increase in hydrogen concentration. Molecular microbial techniques (DGGE/quantitative real-time-PCR) were used to monitor the microbial community changes which were related to data from GC and HPLC analysis. DGGE band patterns showed that the same microorganisms which were already dominant in the original digester re-established again in the lab-scale experiment. Very few microorganisms dominated the whole fermenting process and species diversity was not easily influenced by moderate varying fatty acid amendments--Methanoculleus thermophilus being the most abundant species throughout the variants. MCR-copy number determined via quantitative real-time-PCR--turned out to be a reliable parameter for quantification of methanogens, even in a very complex matrix like fermenter sludge. Generally the downscaled batch approach was shown to be appropriate to investigate microbial communities from large-scale digesters.

Reduction of accumulated volatile fatty acids by an acetate-degrading enrichment culture.

The effects of the addition of an acetate-degrading enrichment culture to an anaerobic digester with a stagnating biogas production were investigated. Initially, a thermophilic batch-operated lab-scale digester was inoculated with the diluted fermenter sludge of a biogas plant, and process parameters including the concentration of volatile fatty acids (VFAs) and gases in the headspace were measured. After a phase of high gas production, a stagnation of biogas production followed for a further 30 days. An acetate enrichment culture was added 34 days after the commencement of the experiment and this resulted in a sharp decrease in the concentrations of accumulated VFAs and an increase in total biogas and CH(4) production. An archaeon with a sequence similarity of 98% to Methanosarcina sp. and the ability to degrade acetic acid was introduced with the enrichment culture and is proposed to have been the driving factor for the changes that occurred within a few days to the process.

Survival of selected pathogens in diluted sludge of a thermophilic waste treatment plant and in NaCl-solution under aerobic and anaerobic conditions.

Decimal reduction times (DRT or D-value) of Campylobacter jejuni, Salmonella enterica (formerly Salmonella choleraesuis) serovar Senftenberg, Escherichia coli, and Listeria monocytogenes were determined in two different matrices, diluted fermenter sludge (DFS) and 0.95% NaCl-solution (NaCl) at 50 degrees C, both under aerobic and anaerobic conditions. Depending on aeration, matrix composition, and the respective organism, the D-values varied between 10min and more than 15h. Generally the viability of bacteria decreased faster in DFS compared to NaCl-solution and under aerobic compared to anaerobic conditions. After 24h no viable cells could be detected in DFS, both under aerobic as well as under anaerobic conditions, whereas viable cells were still found in NaCl solutions. In both matrices the detection limits determined by means of PCR-based and classical microbiological methods were compared and pointed to lower detection limits of the latter methods. Results of the present investigation show that test organisms were far from surviving several days in DFS whereas hydraulic retention times normally used for thermophilic anaerobic digestion are in the range of 2 weeks. However, an underestimation of survival rates of the test organisms seems probable when applying aerobic standard methods.

Application of denaturing high-performance liquid chromatography in microbial ecology: fermentor sludge, compost, and soil community profiling.

Genetic fingerprinting methods, such as denaturing gradient gel electrophoresis (DGGE), are used in microbial ecology for the analysis of mixed microbial communities but are associated with various problems. In the present study we used a new alternative method: denaturing high-performance liquid chromatography (dHPLC). This method was previously shown to work with samples from water and gut flora but had not yet been applied to complex environmental samples. In contrast to other publications dealing with dHPLC, we used a commonly available HPLC system. Samples from different origins (fermentor sludge, compost, and soil), all ecologically significant, were tested, and the 16S rRNA gene was amplified via PCR. After optimization of the HPLC elution conditions, amplicons of pure cultures and mixed microbial populations could be separated successfully. Systematic differentiation was carried out by a cloning approach, since fraction collection of the peaks did not result in satisfactory fragment separation. dHPLC was evaluated as a tool for microbial community analysis on a genetic level and demonstrated major improvements compared to gel-based fingerprinting methods, such as DGGE, that are commonly used in microbial ecology.

Removal of free extracellular DNA from environmental samples by ethidium monoazide and propidium monoazide.

Recently, new DNA extraction techniques (using ethidium monoazide and propidium monoazide) have been developed to discriminate between alive and dead bacterial cells. Nevertheless, for complex environmental samples, no data are available yet. In the present study, these new methods were applied to anaerobic-fermentor sludge and the results were compared to a conventional microbiological approach.

Ability of DNA content and DGGE analysis to reflect the performance condition of an anaerobic biowaste fermenter.

Molecular-microbiological techniques have delivered insight into microbial populations present in anaerobic fermenters, although much information still remains to be elucidated. In this study, the ability of denaturing gradient gel electrophoresis (DGGE) to throw light on microbial community composition was investigated and latter data were compared with the gas production of a 750,000l anaerobic biogas fermenter. During 1 year, samples were taken from two different sites of the reactor and additionally from the substrate material. After DNA extraction and PCR with archaeal and bacterial primers, PCR products were run on denaturing gradient gels to compare band patterns. Using gel-imaging software (GelComparII), two major clusters could be identified. Dominant bands were excised from the gels, reamplified and sequenced. Most sequences were closely related to Lactobacilli and yet uncultured microorganisms. DNA content of all samples was significantly correlated with the gas production measured online. We concluded that PCR and subsequent DGGE are useful to monitor community shifts in anaerobic fermenter sludge. However, as these changes are not readily detectable via DGGE-pattern analysis, alternative factors influencing the fermenter functioning should be found and investigated. So far DNA-content measurement seems to be a good parameter to quickly determine anaerobic fermenter condition.