High-frequency metabolite profiling and the incidence of recurrent cardiac events in patients with post-acute coronary syndrome

Abstract

Purpose: The aim of this study was to study temporal changes in metabolite profiles in patients with post-acute coronary syndrome (ACS), in particular prior to the development of recurrent ACS (reACS).

Methods: BIOMArCS (BIOMarker study to identify the Acute risk of a Coronary Syndrome) is a prospective study including patients admitted for ACS, who underwent high-frequency blood sampling during 1-year follow-up. Within BIOMArCS, we performed a nested case-cohort analysis of 158 patients (28 cases of reACS). We determined 151 metabolites by nuclear magnetic resonance in seven (median) blood samples per patient. Temporal evolution of the metabolites and their relation with reACS was assessed by joint modelling. Results are reported as adjusted (for clinical factors) hazard ratios (aHRs).

Results: Median age was 64 (25th–75th percentiles; 56–72) years and 78% were men. After multiple testing correction (p?<?0.001), high concentrations of extremely large very low density lipoprotein (VLDL) particles (aHR 1.60/SD increase; 95%CI 1.25–2.08), very large VLDL particles (aHR 1.60/SD increase; 95%CI 1.25–2.08) and large VLDL particles (aHR 1.56/SD increase; 95%CI 1.22–2.05) were significantly associated with reACS. Moreover, these longitudinal particle concentrations showed a steady increase over time prior to reACS. Among the other metabolites, no significant associations were observed.

Conclusion: Post-ACS patients with persistent high concentrations of extremely large, very large and large VLDL particles have increased risk of reACS within 1?year.     

Capturing the natural diversity of the human antibody response against vaccinia virus

The eradication of smallpox (variola) and the subsequent cessation of routine vaccination have left modern society vulnerable to bioterrorism employing this devastating contagious disease. The existing, licensed vaccines based on live vaccinia virus (VACV) are contraindicated for a substantial number of people, and prophylactic vaccination of large populations is not reasonable when there is little risk of exposure. Consequently, there is an emerging need to develop efficient and safe therapeutics to be used shortly before or after exposure, either alone or in combination with vaccination. We have characterized the human antibody response to smallpox vaccine (VACV Lister) in immunized volunteers and isolated a large number of VACV-specific antibodies that recognize a variety of different VACV antigens. Using this broad antibody panel, we have generated a fully human, recombinant analogue to plasma-derived vaccinia immunoglobulin (VIG), which mirrors the diversity and specificity of the human antibody immune response and offers the advantage of unlimited supply and reproducible specificity and activity. The recombinant VIG was found to display a high specific binding activity toward VACV antigens, potent in vitro VACV neutralizing activity, and a highly protective efficacy against VACV challenge in the mouse tail lesion model when given either prophylactically or therapeutically. Altogether, the results suggest that this compound has the potential to be used as an effective postexposure prophylaxis or treatment of disease caused by orthopoxviruses.     

Plasma membrane domains participate in pH banding of Chara internodal cells

We investigated the identity and distribution of cortical domains, stained by the endocytic marker FM 1-43, in branchlet internodal cells of the characean green algae Chara corallina and Chara braunii. Co-labeling with NBD C(6)-sphingomyelin, a plasma membrane dye, which is not internalized, confirmed their location in the plasma membrane, and co-labelling with the fluorescent pH indicator Lysotracker red indicated an acidic environment. The plasma membrane domains co-localized with the distribution of an antibody against a proton-translocating ATPase, and electron microscopic data confirmed their identity with elaborate plasma membrane invaginations known as charasomes. The average size and the distribution pattern of charasomes correlated with the pH banding pattern of the cell. Charasomes were larger and more frequent at the acidic regions than at the alkaline bands, indicating that they are involved in outward-directed proton transport. Inhibition of photosynthesis by DCMU prevented charasome formation, and incubation in pH buffers resulted in smaller, homogenously distributed charasomes irrespective of whether the pH was clamped at 5.5 or 8.5. These data indicate that the differential size and distribution of charasomes is not due to differences in external pH but reflects active, photosynthesis-dependent pH banding. The fact that pH banding recovered within several minutes in unbuffered medium, however, confirms that pH banding is also possible in cells with evenly distributed charasomes or without charasomes. Cortical mitochondria were also larger and more abundant at the acid bands, and their intimate association with charasomes and chloroplasts suggests an involvement in carbon uptake and photorespiration.     

Genetic relatedness of the Streptococcus pneumoniae capsular biosynthetic loci

Streptococcus pneumoniae (the pneumococcus) produces 1 of 91 capsular polysaccharides (CPS) that define the serotype. The cps loci of 88 pneumococcal serotypes whose CPS is synthesized by the Wzy-dependent pathway were compared with each other and with additional streptococcal polysaccharide biosynthetic loci and were clustered according to the proportion of shared homology groups (HGs), weighted for the sequence similarities between the genes encoding the shared HGs. The cps loci of the 88 pneumococcal serotypes were distributed into eight major clusters and 21 subclusters. All serotypes within the same serogroup fell into the same major cluster, but in six cases, serotypes within the same serogroup were in different subclusters and, conversely, nine subclusters included completely different serotypes. The closely related cps loci within a subcluster were compared to the known CPS structures to relate gene content to structure. The Streptococcus oralis and Streptococcus mitis polysaccharide biosynthetic loci clustered within the pneumococcal cps loci and were in a subcluster that also included the cps locus of pneumococcal serotype 21, whereas the Streptococcus agalactiae cps loci formed a single cluster that was not closely related to any of the pneumococcal cps clusters.     

The role of laboratory and field leaching tests in hazard identification for solid materials

The use of various in vitro toxicity assays for testing environmental solid samples is dependent on the availability of reliable methods for the sampling and pretreatment of the material. This study focuses on the evaluation of leaching behaviour as a first step in the context of the toxicity testing of solid environmental matter. Spent shale, from oil shale retorting, was chosen as a suitable example of deposited solid waste material. For the generation of leachate in the laboratory setting, a standard two-stage batch-leaching test was applied to the samples of technogenic waste. In the field, a new type of lysimeter, which does not disturb the surface, was used for in situ leachate collection. The chemical composition of water extracts was found to be different under field conditions, as compared with the laboratory experiments. Thus, the hazard identification of a solid technogenic waste by in vitro toxicological tests applied to laboratory leachates would not be the best solution. The content of hazardous ingredients could be underestimated if only laboratory tests are used. For risk assessment concerned with solid waste materials, the generation of leachate by using field lysimeters is recommended.     

<Emphasis Type="Italic">Fusarium</Emphasis> toxins of the scirpentriol subgroup: a review

Scirpentriol and its seven acetylated derivatives comprise a family of type-A trichothecene toxins produced by several species of Fusarium fungi. Out of this group 4,15-diacetoxyscirpenol has attracted most attention. It elicits toxic responses in several species and was detected in a variety of substrates. Out of the three possible monoacetylated derivatives 15-monoacetoxyscirpenol and the parent alcohol scirpentriol received some attention, whereas the remaining members of the family were mentioned in few reports. The present review deals with the structure, biosynthesis, analysis and toxicity of scirpentriol toxins. Formation by Fusarium species as well as culture conditions used for toxigenicity studies are reviewed; data about the natural occurrence of scirpentriol toxins in different cereal types, cereal associated products as well as in non-grain matrices including potato and soya bean are reported. Basing on literature reports about the toxicity of scirpentriol toxins an attempt is made to summarise the state of knowledge for risk evaluation for human and animal health.     

Isolation and characterization of a novel n-alkane-degrading strain, Acinetobacter haemolyticus AR-46

Strain AR-46, isolated and identified as Acinetobacter haemolyticus, evolutionally distant from the known hydrocarbon-degrading Acinetobacter spp., proved to have excellent long-chain n-alkane-degrading ability. This is the first detailed report on an n-alkane-utilizing strain belonging to this species. The preferred substrate is n-hexadecane, with an optimal temperature of 37 degrees C under aerobic conditions. Five complete and two partial open reading frames were sequenced and correlated with the early steps of monoterminal oxidation-initiated n-alkane mineralization. The encoded protein sequences and the arrangement of these genes displayed high similarity to those found in Acinetobacter sp. M-1, but AR-46 seemed to have only one alkane hydroxylase gene, with a completely different induction profile. Unique behaviour was also observed in n-alkane bioavailability. Substrate uptake occurred through the hydrophobic surface of n-alkane droplet-adhered cells possessing long, thick fimbriae, which were presumed to play a major role in n-alkane solubilization. A majority of the cells was in detached form, with thick, but short fimbriae. These free cells were permanently hydrophilic, unlike the cells of other Acinetobacter strains.     

Detection of a rare oligo(A) repeat tract mutation (8As-->7As) in the sequence encoding the La/SS-B autoantigen

Several diseases are characterized by the presence of point mutations, which are amenable to molecular detection using a number of methods such as PCR. However, certain mutations are particularly difficult to detect due to factors such as low abundance and the presence of special (e.g., oligonucleotide repeat) sequences. The mutation 7A in the oligoA sequence of exon 7 of the gene encoding the La autoantigen is difficult to detect at the DNA level, and even at the RNA level, due to both its estimated low abundance and its differentiation from the wild-type 8A sequence. This article describes a technique in which amplification of the excess wild-type 8A La sequence is suppressed by a peptide nucleic acid (PNA) during a nested PCR step. Detection of the amplified 7A mutant form was then performed by simple electrophoresis following a final primer extension step with an infrared dye-labeled primer. This technique allowed us to detect the mutation in 3 of 7 individuals harboring serum immunoglobulin G (IgG) antibodies reactive with a neo-B cell epitope in the 7A mutant protein product. We propose that this method is a viable screening test for mutations in regions containing simple polynucleotide repeats.     

The temporal pattern of immune and inflammatory proteins prior to a recurrent coronary event in post-acute coronary syndrome patients

Purpose: We assessed the temporal pattern of 29 immune and inflammatory proteins in post-acute coronary syndrome (ACS) patients, prior to the development of recurrent ACS.

Methods: High-frequency blood sampling was performed in 844 patients admitted for ACS during one-year follow-up. We conducted a case-control study on the 45 patients who experienced reACS (cases) and two matched event-free patients (controls) per case. Olink Proteomics’ immunoassay was used to obtain serum levels of the 29 proteins, expressed in an arbitrary unit on the log2-scale (Normalized Protein eXpression, NPX). Linear mixed-effects models were applied to examine the temporal pattern of the proteins, and to illustrate differences between cases and controls.

Results: Mean age was 66?±?12 years and 80% were men. Cases and controls had similar baseline clinical characteristics. During the first 30 days, and after multiple testing correction, cases had significantly higher serum levels of CXCL1 (difference of 1.00 NPX, p?=?0.002), CD84 (difference of 0.64 NPX, p?=?0.002) and TNFRSF10A (difference of 0.41 NPX, p?<?0.001) than controls. After 30 days, serum levels of all 29 proteins were similar in cases and controls. In particular, no increase was observed prior to reACS.

Conclusions: Among 29 immune and inflammatory proteins, CXCL1, CD84 and TNFRSF10A were associated with early reACS after initial ACS-admission.