Single-stage repair of adult aortic coarctation and concomitant cardiovascular pathologies: a new alternative surgical approach

BACKGROUND: Coarctation of the aorta in the adulthood is sometimes associated with additional cardiovascular pathologies that require intervention. Ideal approach in such patients is uncertain. Anatomic left-sided short aortic bypass from the arcus aorta to descending aorta via median sternotomy allows simultaneuos repair of both complex aortic coarctation and concomitant cardiac operation. MATERIALS: Four adult patients were underwent Anatomic left-sided short aortic bypass operation for complex aortic coarctation through median sternotomy using deep hypothermic circulatory arrest. Concomitant cardiac operations were Bentall procedure for annuloaortic ectasia in one patient, coronary artery bypass grafting for three vessel disease in two patient, and patch closure of ventricular septal defect in one patient. RESULTS: All patients survived the operation and were alive with patent bypass at a mean follow-up of 36 months. No graft-related complications occurred, and there were no instances of stroke or paraplegia. CONCLUSION: We conclude that single-stage repair of adult aortic coarctation with concomitant cardiovascular lesions can be performed safely using this newest technique

Examining the impact of agricultural drainage ditch management on in-stream bacterial communities involved in nitrogen cycling: insights from the Environmental Change One Health Observatory (ECO2)

IntroductionAgricultural drainage ditches are essential for maintaining flow efficiency and are often managed by brushing (i.e., vegetation clearing along ditch banks) and dredging. These maintenance practices not only impact flow but also the ditches’ capacity to process and assimilate agricultural chemicals. However, the influence of ditch management on microbial activities, essential in processing and transforming these contaminants, remains underexplored.MethodsWe conducted a four-year surface water sampling campaign in two long-established (over 40 years) agricultural drainage ditches situated in eastern Ontario, Canada. One drainage ditch underwent intensive bank brushing and channel dredging, while the other remained unmanaged. We assessed the impact of these contrasting ditch management practices on the diversity and compositional structure of surface water microbiome communities, with a particular focus on the distribution of genes associated with nitrogen (N) cycling, using shotgun metagenomics sequencing and an assembly-based metagenome approach.Results and discussionFrom 117 surface water samples, we reconstructed 157 metagenome-assembled genomes (MAGs), predominantly from the Patescibacteria superphylum. Brushing alone, conducted about 10 months prior to dredging, had an insignificant impact on the aquatic microbial community. However, dredging led to a significant reduction in community diversity and abundance of genes affiliated with denitrification, dissimilatory nitrate reduction to ammonia, and complete nitrification through comammox. Ditch management resulted in noticeable shifts in the microbial community, evidenced by the enrichment of taxa in Polaromonas, Emticicia, Flectobacillus, and Patescibacteria in the water of the managed ditch sites. The metagenomes of these taxa harbor genes involved in various nitrogen biotransformation pathways. Interestingly, following dredging, the levels of ammonia and ammonium, nitrite, and total Kjeldahl N in the managed ditch did not increase, but significantly decreased; likely due to ditch substrate removal and potentially increased flow efficiency and dilution. Being one of the few studies conducted to date, this study provided unique insights into the consequences of drainage ditch management on freshwater microbiomes involved in N cycling

Susceptibility of Mycobacterium immunogenum and Pseudomonas fluorescens to Formaldehyde and Non-Formaldehyde Biocides in Semi-Synthetic Metalworking Fluids

Mycobacterium immunogenum, a newly identified member of the Mycobacterium chelonae_M. abscessus complex is considered a potential etiological agent for hypersensitivity pneumonitis (HP) in machine workers exposed to contaminated metalworking fluid (MWF). This study investigated the biocidal efficacy of the frequently applied commercial formaldehyde-releasing (HCHO) biocides Grotan and Bioban CS 1135 and non-HCHO type biocides Kathon 886 MW (isothiazolone) and Preventol CMK 40 (phenolic) toward this emerging mycobacterial species (M. immunogenum) in HP-linked MWFs, alone and in presence of a representative of the Gram-negative bacterial contaminants, Pseudomonas fluorescens, using two semi-synthetic MWF matrices (designated Fluid A and Fluid B). Relative biocide susceptibility analysis indicated M immunogenum to be comparatively more resistant (2–1600 fold) than P. fluorescens to the tested biocides under the varied test conditions. In terms of minimum inhibitory concentration, Kathon was the most effective biocide against M. immunogenum. Fluid factors had a major effect on the biocide susceptibility. Fluid A formulation provided greater protective advantage to the test organisms than Fluid B. Fluid dialysis (Fluid A) led to an increased biocidal efficacy of Grotan, Kathon and Preventol against M. immunogenum further implying the role of native fluid components. Used fluid matrix, in general, increased the resistance of the two test organisms against the biocides, with certain exceptions. M. immunogenum resistance increased in presence of the co-contaminant P. fluorescens. Collectively, the results show a multifactorial nature of the biocide susceptibility of MWF-colonizing mycobacteria and highlight the importance of more rigorous efficacy testing and validation of biocides prior to and during their application in metalworking fluid operations

Aquatic Bacterial Communities Associated With Land Use and Environmental Factors in Agricultural Landscapes Using a Metabarcoding Approach

This study applied a 16S rRNA gene metabarcoding approach to characterize bacterial community compositional and functional attributes for surface water samples collected within, primarily, agriculturally dominated watersheds in Ontario and Québec, Canada. Compositional heterogeneity was best explained by stream order, season, and watercourse discharge. Generally, community diversity was higher at agriculturally dominated lower order streams, compared to larger stream order systems such as small to large rivers. However, during times of lower relative water flow and cumulative 2-day rainfall, modestly higher relative diversity was found in the larger watercourses. Bacterial community assemblages were more sensitive to environmental/land use changes in the smaller watercourses, relative to small-to-large river systems, where the proximity of the sampled water column to bacteria reservoirs in the sediments and adjacent terrestrial environment was greater. Stream discharge was the environmental variable most significantly correlated (all positive) with bacterial functional groups, such as C/N cycling and plant pathogens. Comparison of the community structural similarity via network analyses helped to discriminate sources of bacteria in freshwater derived from, for example, wastewater treatment plant effluent and intensity and type of agricultural land uses (e.g., intensive swine production vs. dairy dominated cash/livestock cropping systems). When using metabarcoding approaches, bacterial community composition and coexisting pattern rather than individual taxonomic lineages, were better indicators of environmental/land use conditions (e.g., upstream land use) and bacterial sources in watershed settings. Overall, monitoring changes and differences in aquatic microbial communities at regional and local watershed scales has promise for enhancing environmental footprinting and for better understanding nutrient cycling and ecological function of aquatic systems impacted by a multitude of stressors and land uses

Carfilzomib and dexamethasone versus bortezomib and dexamethasone for patients with relapsed or refractory multiple myeloma (ENDEAVOR): And randomised, phase 3, open-label, multicentre study

Background: Bortezomib with dexamethasone is a standard treatment option for relapsed or refractory multiple myeloma. Carfilzomib with dexamethasone has shown promising activity in patients in this disease setting. The aim of this study was to compare the combination of carfilzomib and dexamethasone with bortezomib and dexamethasone in patients with relapsed or refractory multiple myeloma. Methods: In this randomised, phase 3, open-label, multicentre study, patients with relapsed or refractory multiple myeloma who had one to three previous treatments were randomly assigned (1:1) using a blocked randomisation scheme (block size of four) to receive carfilzomib with dexamethasone (carfilzomib group) or bortezomib with dexamethasone (bortezomib group). Randomisation was stratified by previous proteasome inhibitor therapy, previous lines of treatment, International Staging System stage, and planned route of bortezomib administration if randomly assigned to bortezomib with dexamethasone. Patients received treatment until progression with carfilzomib (20 mg/m2 on days 1 and 2 of cycle 1; 56 mg/m2 thereafter; 30 min intravenous infusion) and dexamethasone (20 mg oral or intravenous infusion) or bortezomib (1·3 mg/m2; intravenous bolus or subcutaneous injection) and dexamethasone (20 mg oral or intravenous infusion). The primary endpoint was progression-free survival in the intention-to-treat population. All participants who received at least one dose of study drug were included in the safety analyses. The study is ongoing but not enrolling participants; results for the interim analysis of the primary endpoint are presented. The trial is registered at ClinicalTrials.gov, number NCT01568866. Findings: Between June 20, 2012, and June 30, 2014, 929 patients were randomly assigned (464 to the carfilzomib group; 465 to the bortezomib group). Median follow-up was 11·9 months (IQR 9·3-16·1) in the carfilzomib group and 11·1 months (8·2-14·3) in the bortezomib group. Median progression-free survival was 18·7 months (95% CI 15·6-not estimable) in the carfilzomib group versus 9·4 months (8·4-10·4) in the bortezomib group at a preplanned interim analysis (hazard ratio [HR] 0·53 [95% CI 0·44-0·65]; p<0·0001). On-study death due to adverse events occurred in 18 (4%) of 464 patients in the carfilzomib group and in 16 (3%) of 465 patients in the bortezomib group. Serious adverse events were reported in 224 (48%) of 463 patients in the carfilzomib group and in 162 (36%) of 456 patients in the bortezomib group. The most frequent grade 3 or higher adverse events were anaemia (67 [14%] of 463 patients in the carfilzomib group vs 45 [10%] of 456 patients in the bortezomib group), hypertension (41 [9%] vs 12 [3%]), thrombocytopenia (39 [8%] vs 43 [9%]), and pneumonia (32 [7%] vs 36 [8%]). Interpretation: For patients with relapsed or refractory multiple myeloma, carfilzomib with dexamethasone could be considered in cases in which bortezomib with dexamethasone is a potential treatment option. Funding: Onyx Pharmaceuticals, Inc., an Amgen subsidiary

Multi-response optimization of electrothermal micromirror using desirability function-based response surface methodology

The design of a micromirror for biomedical applications requires multiple output responses to be optimized, given a set of performance parameters and constraints. This paper presents the parametric design optimization of an electrothermally actuated micromirror for the deflection angle, input power, and micromirror temperature rise from the ambient for Optical Coherence Tomography (OCT) system. Initially, a screening design matrix based on the Design of Experiments (DOE) technique is developed and the corresponding output responses are obtained using coupled structural-thermal-electric Finite Element Modeling (FEM). The interaction between the significant design factors is analyzed by developing Response Surface Models (RSM) for the output responses. The output responses are optimized by combining the individual responses into a composite function using desirability function approach. A downhill simplex method, based on the heuristic search algorithm, is implemented on the RSM models to find the optimal levels of the design factors. The predicted values of output responses obtained using multi-response optimization are verified by the FEM simulations. © 2017 by the authors

Development of a Single-Tube, Cell Lysis-Based, Genus-Specific PCR Method for Rapid Identification of Mycobacteria: Optimization of Cell Lysis, PCR Primers and Conditions, and Restriction Pattern Analysis

A single-tube PCR method was developed for efficient identification of nontuberculous mycobacteria (NTM) and their environmental isolates in about 3 h without conventional DNA isolation. The following three steps were optimized or developed: (i) a simple, 6-min direct cell lysis protocol as a PCR prestep for generation of DNA-template, (ii) an improved Mycobacterium-specific PCR amplification protocol with a broader species specificity using newly designed primers targeting a 228-bp region of the 65-kDa heat shock protein (hsp) gene and optimal PCR amplification conditions, and (iii) a genus-specific restriction analysis of the PCR product for conclusive identification of the unknown NTM isolates

Biocidal Activity of Formaldehyde and Nonformaldehyde Biocides toward Mycobacterium immunogenum and Pseudomonas fluorescens in Pure and Mixed Suspensions in Synthetic Metalworking Fluid and Saline

The microbicidal activity of four different biocides was studied in synthetic metalworking fluid (MWF) against Mycobacterium immunogenum, a suspected causative agent for hypersensitivity pneumonitis, and Pseudomonas fluorescens, a representative for the predominant gram-negative bacterial contaminants of MWF. The results indicated that M. immunogenum is more resistant than P. fluorescens to the tested formaldehyde-releasing biocides (Grotan and Bioban), isothiazolone (Kathon), and phenolic biocide (Preventol). Kathon was effective against mycobacteria at lower concentrations than the other three test biocides in MWF. In general, there was a marked increase in biocidal resistance of both the test organisms when present in MWF matrix compared to saline. Increased resistance of the two test organisms to biocides was observed when they were in a mixed suspension (1:1 ratio). The results indicate the protective effect of the MWF matrix against the action of commonly used biocides on the MWF-colonizing microbial species of occupational health significance, including mycobacteria

Method for Rapid Identification and Differentiation of the Species of the Mycobacterium chelonae Complex Based on 16S-23S rRNA Gene Internal Transcribed Spacer PCR-Restriction Analysis

Members of the Mycobacterium chelonae complex (MCC), including M. immunogenum, M. chelonae, and M. abscessus, have been associated with nosocomial infections and occupational hypersensitivity pneumonitis due to metalworking fluid (MWF) exposures. In order to minimize these health hazards, an effective and rapid assay for detection of MCC species and differentiation of MCC species from other species of rapidly growing mycobacteria (RGM) and from one another is warranted. Here we report such a method, based on the variable 16S-23S rRNA gene internal transcribed spacer (ITS) region. Mycobacterium genus-specific primers derived from highly conserved sequences in the ITS region and the flanking 16S rRNA gene were used. Specificity of the primers was verified using the MCC member species, 11 non-MCC RGM species, 3 slow-growing mycobacterial (SGM) species (two strains each), and 19 field isolates, including 18 MCC isolates (from in-use MWF) and one non-MCC isolate (from reverse osmosis water). The ITS amplicon size of M. immunogenum varied from those of M. chelonae and M. abscessus. Sequencing of the ∼250-bp-long ITS amplicons of the three MCC member species showed differences in 24 to 34 bases, thereby yielding variable deduced restriction maps. ITS PCR-restriction analysis using the in silico-selected restriction enzyme MaeII or HphI differentiated the three MCC members from one another and from other RGM and SGM species without sequencing. The enzyme MaeII discriminated all three member species; however, HphI could only differentiate M. immunogenum from M. chelonae and M. abscessus. Use of an optimized rapid DNA template preparation step based on direct cell lysis in the PCR tube added to the simplicity and adaptability of the developed assay