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Post-capillary hypertension resulting from mitral regurgitation is typically considered a contraindication for single lung transplantation due to heightened risks of primary graft dysfunction. This case report highlights a 66-year-old COPD patient with severe mitral regurgitation who was deemed ineligible for surgical mitral replacement. As an alternative, transcatheter mitral valve replacement was successfully performed, resulting in the normalization of pulmonary artery pressures. Consequently, the patient became eligible for single lung transplantation, which was conducted successfully in the subsequent months. Eighteen months post-lung transplantation, the patient now experiences a normal functional status and excellent lung function. In conclusion, transcatheter mitral valve replacement appears to be a safe alternative to surgery for normalizing post-capillary pulmonary hypertension in patients with chronic respiratory diseases. This approach could potentially facilitate lung transplantation (LTx) in eligible candidates.

Aster yellows phytoplasmas (AYp) are a group of obligate parasites that infect a wide range of plant species, including crops such as canola and cereals and noncrops such as dandelion and wild mustard. In the Canadian Prairies, these microorganisms are mainly transmitted by a migratory species of leafhopper (Macrosteles quadrilineatus Forbes). Although a low incidence of the disease associated with this pathogen has been reported for most years in canola fields, several outbreaks have been documented in this region. A selection of crop and noncrop species commonly found in the Canadian Prairies and Arabidopsis thaliana were used to assess the suitability of these plant species as hosts for AYp (16SrI-B). Symptom expression and phytoplasma levels were examined at different time points following exposure to infective insects. A. thaliana, barley, and canola were susceptible to infection with AYp, yet symptoms differed among these plant species. A. thaliana and canola exhibited symptoms of infection as early as 2 weeks following exposure to infected insects, whereas symptoms in barley were observed at 5 weeks. A lower incidence rate was observed in wheat, and levels of AYp in phytoplasma-infected wheat plants were low. Dandelion and sowthistle tested negative for the presence of AYp at all time points, suggesting that these are unsuitable hosts for these microorganisms. Moreover, we observed a partial disassociation between the plant species that were suitable hosts for AYp and those that had been characterized as more suitable or suitable hosts for aster leafhopper oviposition and nymphal development in previous studies. [Figure: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Biological delignification using white-rot fungi is a possible approach in the pretreatment of lignocellulosic biomass. Despite the considerable promise of this low-input, environmentally-friendly pretreatment strategy, its large-scale application is still limited. Therefore, understanding the best combination of factors which affect biological pretreatment and its impact on enzymatic hydrolysis is essential for its commercialization. The present study was conducted to evaluate the impact of fungal pretreatment on the enzymatic digestibility of switchgrass under solid-state fermentation (SSF) using Phanerochaete chrysosporium (PC), Trametes versicolor 52J (Tv 52J), and a mutant strain of Trametes versicolor that is cellobiose dehydrogenase-deficient (Tv m4D). Response surface methodology and analysis of variance (ANOVA) were employed to ascertain the optimum pretreatment conditions and the effects of pretreatment factors on delignification, cellulose loss, and total available carbohydrate (TAC). Pretreatment with Tv m4D gave the highest TAC (73.4%), while the highest delignification (23.6%) was observed in the PC-treated sample. Fermentation temperature significantly affected the response variables for the wild-type fungal strains, while fermentation time was the main significant factor for Tv m4D. The result of enzymatic hydrolysis with fungus-treated switchgrass at optimum pretreatment conditions showed that pretreatment with the white-rot fungi enhanced enzymatic digestibility with wild-type T. versicolor (52J)-treated switchgrass, yielding approximately 64.9% and 74% more total reducing sugar before and after densification, respectively, than the untreated switchgrass sample. Pretreatment using PC and Tv 52J at low severity positively contributed to enzymatic digestibility but resulted in switchgrass pellets with low unit density and tensile strength compared to the pellets from the untreated switchgrass.

Introduction: Cytomegalovirus (CMV) infections are frequent in solid organ transplant recipients and associated with increased allograft dysfunction. Clinical story: We report the case of a 58-year-old lung transplant recipient (CMV mismatched) who presented with severe acute kidney injury (AKI) without any other organ involvement. Urinalysis showed moderate proteinuria, leukocyturia, and hematuria suggestive of interstitial nephritis, while renal/urinary tract ultrasound was normal. Anamnesis excluded iatrogenic AKI causes including contrast- and non-steroidal anti-inflammatory drugs-induced AKI, while dedicated blood tests excluded other AKI causes such as vasculitis, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection, thrombotic microangiopathy, tacrolimus overdosage, rhabdomyolysis. Urine and serum CMV polymerase chain reaction (PCR) were strongly positive, while urine BK virus was negative. A renal biopsy could not be performed due to anticoagulation and logistic reasons. Diagnosis: Based on the existing literature, we made a presumptive diagnosis of CMV nephritis and initiated intravenous antiviral therapy with ganciclovir. Within a few weeks, renal function improved but did not fully recover. Conclusion: CMV nephritis is very rare in nonkidney solid organ transplant recipient but should be investigated in case of acute kidney injury as it may lead to chronic renal impairment.

BackgroundCOPD increases susceptibility to sleep disturbances, which may in turn predispose to increased respiratory symptoms. The objective of this study was to evaluate, in a population-based sample, the relationship between subjective sleep quality and risk of COPD exacerbations.MethodsData were obtained from the Canadian Cohort Obstructive Lung Disease (CanCOLD) study. Participants with COPD who had completed 18 months of follow-up were included. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI) and a three-factor analysis. Symptom-based (dyspnea or sputum change ≥ 48 h) and event-based (symptoms plus medication or unscheduled health services use) exacerbations were assessed. Association of PSQI with exacerbation rate was assessed by using negative binomial regression. Exacerbation-free survival was also assessed.ResultsA total of 480 participants with COPD were studied, including 185 with one or more exacerbations during follow-up and 203 with poor baseline sleep quality (PSQI score > 5). Participants with subsequent symptom-based exacerbations had higher median baseline PSQI scores than those without (6.0 [interquartile range, 3.0-8.0] vs 5.0 [interquartile range, 2.0-7.0]; P = .01), and they were more likely to have baseline PSQI scores > 5 (50.3% vs 37.3%; P = .01). Higher PSQI scores were associated with increased symptom-based exacerbation risk (adjusted rate ratio, 1.09; 95% CI, 1.01-1.18; P = .02) and event-based exacerbation risk (adjusted rate ratio, 1.10; 95% CI, 1.00-1.21; P = .048). The association occurred mainly in those with undiagnosed COPD. Strongest associations were with Factor 3 (sleep disturbances and daytime dysfunction). Time to symptom-based exacerbation was shorter in participants with poor sleep quality (adjusted hazard ratio, 1.49; 95% CI, 1.09-2.03).ConclusionsHigher baseline PSQI scores were associated with increased risk of COPD exacerbation over 18 months' prospective follow-up.

The current study explores steam explosion pre-treatment of wood sawdust to develop high-quality biofuel pellets. In order to determine optimized conditions (temperature and residence time) for steam-treated biomass, seven test responses were chosen, including bulk, particle and pellet densities as well as tensile strength, dimensional stability, ash content and higher heating value (HHV). Parameters tested for steam treatment process included the combination of temperatures 180, 200 and 220 °C and durations of 3, 6 and 9 min. Results showed that when the severity of steam pre-treatment increased from 2.83 to 4.49, most of the qualities except HHV and ash content were favorable for steam pretreated materials. The pellet density of pretreated sawdust in comparison to raw sawdust resulted in 20% improvement (1262 kg/m3 for pretreated material compared with 1049 kg/m3 for non-treated material). Another important factor in determining the best pellet quality is tensile strength, which can be as high as 5.59 MPa for pretreated pellets compared with 0.32 MPa for non-treated pellets. As a result, transportation and handling properties can be enhanced for steam pretreated biomass pellets. After optimization, the selected treatment was analyzed for elemental and chemical composition. Lower nitrogen and sulfur contents compared with fossil fuels make steam pretreated pellets a cleaner option for home furnaces and industrial boilers. High-quality pellets were produced based on optimized pre-treatment conditions and are therefore suggested for bioenergy applications.

The possibility of applying biochar in mild torrefaction treatment to improve the thermochemical characteristics of ground biomass was the focus of the study. Camelina straw and switchgrass were torrefied in a reactor using microwave irradiation at torrefaction temperatures of 250 °C and 300 °C with residence times 10, 15 and 20 min, under nitrogen-activated inert conditions. Both biochar addition of more than 10% and residence time significantly affected the product yields, as MW torrefaction temperatures shifted from 250 °C to 300 °C. Overall, the results indicated a slight increase in ash content, mass loss percentage intensification, heating values, and fixed carbon, while moisture content and volatile matter decreased in camelina straw and switchgrass, with or without biochar. Biochar addition with a long residence time (20 min) at 250 °C reduced energy requirement during the microwave torrefaction process. The combustion index values showed that torrefied camelina straw or switchgrass with biochar addition suits co-combustion with coal in a coal-fired plant and is a potential biomaterial for biofuel pellets.

A one-year-old female Eastern black-and-white Colobus (Colobus guereza) was evaluated after tangling its right forelimb in exhibit netting. Radiographs of the right forelimb revealed craniolateral luxation of the radial head and a complete transverse fracture of the proximal ulna, otherwise known as a type III Monteggia fracture. Open reduction was performed and a locking cuttable bone plate was placed to address the ulnar fracture. The reduced radial head was maintained by the placement of a Mini Tightrope Fixation System. Rapid return to normal activity was observed. Radiographs taken four weeks post-operatively showed healing of the fracture as well as appropriate articulation of the radial head. At three years post-operatively, the Colobus continued to demonstrate normal ambulation without evidence of growth disruption. This is the first documented report of this specific surgical technique and implant in an exotic species. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass has demonstrated great potential as feedstock for pellet production, notwithstanding the fact that the industrial production of pellets is faced with some economic challenges. This study presents a technoeconomic analysis of six scenarios to develop a process model for pellet production from sawdust and oat straw that employs torrefaction and steam explosion pretreatment prior to pelletization. SuperPro Designer was used to carry out this evaluation. The pellet plants were designed to have a capacity of 9.09 t/h of sawdust and oat straw each. The pellet yield ranged from 59 kt to 72 kt/year. The scenarios analyzed included variations of steam explosion and torrefaction. In some scenarios, materials were lost in the form of liquid and gas due to the pretreatment process. The breakdown of equipment purchase cost showed that the torrefaction reactor is the most expensive unit with approximately 51% of the purchase cost. Facility-dependent and feedstock costs were the major significant contributors to the pellet production cost. The minimum selling prices of the pellets obtained from Scenarios 1–6 were $113.4/t, $118.7/t, $283.4/t, $298.7/t, $200.5/t, and $208.4/t, respectively. The profitability of pellet production as determined by the net present value (NPV), internal rate of return (IRR), and payback period was found to be sensitive to variations in feedstock cost.

Abstract Background The cause of the motor neuron (MN) death that drives terminal pathology in amyotrophic lateral sclerosis (ALS) remains unknown, and it is thought that the cellular environment of the MN may play a key role in MN survival. Several lines of evidence implicate vesicles in ALS, including that extracellular vesicles may carry toxic elements from astrocytes towards MNs, and that pathological proteins have been identified in circulating extracellular vesicles of sporadic ALS patients. Because MN degeneration at the neuromuscular junction is a feature of ALS, and muscle is a vesicle‐secretory tissue, we hypothesized that muscle vesicles may be involved in ALS pathology. Methods Sporadic ALS patients were confirmed to be ALS according to El Escorial criteria and were genotyped to test for classic gene mutations associated with ALS, and physical function was assessed using the ALSFRS‐R score. Muscle biopsies of either mildly affected deltoids of ALS patients (n = 27) or deltoids of aged‐matched healthy subjects (n = 30) were used for extraction of muscle stem cells, to perform immunohistology, or for electron microscopy. Muscle stem cells were characterized by immunostaining, RT‐qPCR, and transcriptomic analysis. Secreted muscle vesicles were characterized by proteomic analysis, Western blot, NanoSight, and electron microscopy. The effects of muscle vesicles isolated from the culture medium of ALS and healthy myotubes were tested on healthy human‐derived iPSC MNs and on healthy human myotubes, with untreated cells used as controls. Results An accumulation of multivesicular bodies was observed in muscle biopsies of sporadic ALS patients by immunostaining and electron microscopy. Study of muscle biopsies and biopsy‐derived denervation‐naïve differentiated muscle stem cells (myotubes) revealed a consistent disease signature in ALS myotubes, including intracellular accumulation of exosome‐like vesicles and disruption of RNA‐processing. Compared with vesicles from healthy control myotubes, when administered to healthy MNs the vesicles of ALS myotubes induced shortened, less branched neurites, cell death, and disrupted localization of RNA and RNA‐processing proteins. The RNA‐processing protein FUS and a majority of its binding partners were present in ALS muscle vesicles, and toxicity was dependent on the expression level of FUS in recipient cells. Toxicity to recipient MNs was abolished by anti‐CD63 immuno‐blocking of vesicle uptake. Conclusions ALS muscle vesicles are shown to be toxic to MNs, which establishes the skeletal muscle as a potential source of vesicle‐mediated toxicity in ALS.

Abstract Among the mutations arising in the DMD gene and causing Duchenne Muscular Dystrophy (DMD), 10–15% are multi-exon duplications. There are no current therapeutic approaches with the ability to excise large multi-exon duplications, leaving this patient cohort without mutation-specific treatment. Using CRISPR/Cas9 could provide a valid alternative to achieve targeted excision of genomic duplications of any size. Here we show that the expression of a single CRISPR/Cas9 nuclease targeting a genomic region within a DMD duplication can restore the production of wild-type dystrophin in vitro. We assessed the extent of dystrophin repair following both constitutive and transient nuclease expression by either transducing DMD patient-derived myoblasts with integrating lentiviral vectors or electroporating them with CRISPR/Cas9 expressing plasmids. Comparing genomic, transcript and protein data, we observed that both continuous and transient nuclease expression resulted in approximately 50% dystrophin protein restoration in treated myoblasts. Our data demonstrate that a high transient expression profile of Cas9 circumvents its requirement of continuous expression within the cell for targeting DMD duplications. This proof-of-concept study therefore helps progress towards a clinically relevant gene editing strategy for in vivo dystrophin restoration, by highlighting important considerations for optimizing future therapeutic approaches.

Advancing microbial pretreatment of lignocellulose has the potential not only to reduce the carbon footprint and environmental impacts of the pretreatment processes from cradle-to-grave, but also increase biomass valorization, support agricultural growers, and boost the bioeconomy. Mathematical modeling of microbial pretreatment of lignocellulose provides insights into the metabolic activities of the microorganisms as responses to substrate and environment and provides baseline targets for the design, development, and optimization of solid-state-fermentation (SSF) bioreactors, including substrate concentrations, heat and mass transfer. In this study, the growth of Trametes versicolor 52J (TV52J), Trametes versicolor m4D (TVm4D), and Phanerochaete chrysosporium (PC) on camelina straw (CS) and switchgrass (SG) during an SSF process was examined. While TV52J illustrated the highest specific growth rate and maximum cell concentration, a mutant strain deficient in cellulose catabolism, TVm4D, performed best in terms of holocellulose preservation and delignification. The hybrid logistic-Monod equation along with holocellulose consumption and delignification models described well the growth kinetics. The oxygen uptake rate and carbon dioxide production rate were directly correlated to the fungal biomass concentration; however, a more sophisticated non-linear relationship might explain those correlations better than a linear model. This study provides an informative baseline for developing SSF systems to integrate fungal pretreatment into a large-scale, on-farm, wet-storage process for the utilization of agricultural residues as feedstocks for biofuel production.

Birth mode has been implicated as a major factor influencing neonatal gut microbiome development, and it has been assumed that lack of exposure to the maternal vaginal microbiome is responsible for gut dysbiosis among caesarean-delivered infants. Consequently, practices to correct dysbiotic gut microbiomes, such as vaginal seeding, have arisen while the effect of the maternal vaginal microbiome on that of the infant gut remains unknown. We conducted a longitudinal, prospective cohort study of 621 Canadian pregnant women and their newborn infants and collected pre-delivery maternal vaginal swabs and infant stool samples at 10-days and 3-months of life. Using cpn60-based amplicon sequencing, we defined vaginal and stool microbiome profiles and evaluated the effect of maternal vaginal microbiome composition and various clinical variables on the development of the infant stool microbiome. Infant stool microbiomes showed significant differences in composition by delivery mode at 10-days postpartum; however, this effect could not be explained by maternal vaginal microbiome composition and was vastly reduced by 3 months. Vaginal microbiome clusters were distributed across infant stool clusters in proportion to their frequency in the overall maternal population, indicating independence of the two communities. Intrapartum antibiotic administration was identified as a confounder of infant stool microbiome differences and was associated with lower abundances of Escherichia coli, Bacteroides vulgatus, Bifidobacterium longum and Parabacteroides distasonis. Our findings demonstrate that maternal vaginal microbiome composition at delivery does not affect infant stool microbiome composition and development, suggesting that practices to amend infant stool microbiome composition focus factors other than maternal vaginal microbes.

Abstract Background Facioscapulohumeral dystrophy (FSHD) is caused by mutations leading to the aberrant expression of the DUX4 transcription factor in muscles. DUX4 was proposed to induce cell death, but the involvement of different death pathways is still discussed. A possible pro‐apoptotic role of DUX4 was proposed, but as FSHD muscles are characterized by necrosis and inflammatory infiltrates, non‐apoptotic pathways may be also involved. Methods We explored DUX4‐mediated cell death by focusing on the role of one regulated necrosis pathway called necroptosis, which is regulated by RIPK3. We investigated the effect of necroptosis on cell death in vitro and in vivo experiments using RIPK3 inhibitors and a RIPK3‐deficient transgenic mouse model. Results We showed in vitro that DUX4 expression causes a caspase‐independent and RIPK3‐mediated cell death in both myoblasts and myotubes. In vivo, RIPK3‐deficient animals present improved body and muscle weights, a reduction of the aberrant activation of the DUX4 network genes, and an improvement of muscle histology. Conclusions These results provide evidence for a role of RIPK3 in DUX4‐mediated cell death and open new avenues of research.

Abstract Blueberry stunt phytoplasma (BBSP; ‘Candidatus Phytoplasma asteris’) is an insect-vectored plant pathogen that causes severe yield losses in blueberry (Vaccinium corymbosum), which is the most valuable fruit crop in Canada. Rapid, field-based diagnostic assays are desirable tools for the control of BBSP, as part of an integrated, proactive approach to production management termed biovigilance. We designed and validated a chaperonin-60 (cpn60)-targeted LAMP assay for detection of BBSP, providing a rapid, low cost, field-deployable diagnostic option. Our validation demonstrates that the assay is reproducible, with high analytical specificity and improved sensitivity when compared with 16S rRNA nested PCR. We applied the validated LAMP assay to nearly 2000 blueberry samples from Québec and Nova Scotia over three growing seasons (2016–2018). Our surveys revealed that BBSP is present in most sites across both provinces, though detection of the pathogen in individual plants varied in different tissues across sampling dates and across years, and evidence of spread between plants was limited. To quantify pathogen load in select plants, we designed additional qPCR and ddPCR assays, also based on cpn60. We found that pathogen load fluctuates in individual plants, both within and between growing seasons. Finally, we designed an interactive map to visualize the results of our surveys. These results provide a validated diagnostic assay that can be used as part of a biovigilance strategy for detecting and controlling infections caused by BBSP.

Phytoplasmas are insect-vectored, difficult-to-culture bacterial pathogens that infect a wide variety of crop and non-crop plants, and are associated with diseases that can lead to significant yield losses in agricultural production worldwide. Phytoplasmas are currently grouped in the provisional genus ‘Candidatus Phytoplasma’, which includes 49 ‘Candidatus’ species. Further differentiation of phytoplasmas into ribosomal groups is based on the restriction fragment length polymorphism (RFLP) pattern of the 16S rRNA-encoding operon, with more than 36 ribosomal groups (16Sr) and over 100 subgroups reported. Since disease symptoms on plants are not associated with phytoplasma identity, accurate diagnostics is of critical importance to manage disease associated with these microorganisms. Phytoplasmas are typically detected from plant and insect tissue using PCR-based methods targeting universal taxonomic markers. Although these methods are relatively sensitive, specific and are widely used, they have limitations, since they provide limited resolution of phytoplasma strains, thus necessitating further assessment of biological properties and delaying implementation of mitigation measures. Moreover, the design of PCR primers that can target multiple loci from phytoplasmas that differ at the sequence level can be a significant challenge. To overcome these limitations, a PCR-independent, multilocus sequence typing (MLST) assay to characterize an array of phytoplasmas was developed. Hybridization probe s targeting cpn60, tuf, secA, secY, and nusA genes, as well as 16S and rp operons, were designed and used to enrich DNA extracts from phytoplasma-infected samples for DNA fragments corresponding to these markers prior to Illumina sequencing. This method was tested using different phytoplasmas including ‘Ca. P. asteris’ (16SrI-B), ‘Ca. P. pruni’ (16SrIII-A),‘Ca. P. prunorum’ (16SrX-B), ‘Ca. P. pyri’ (16SrX-C), ‘Ca. P. mali’ (16SrX-A), and ‘Ca. P. solani’ (16SrXII-A). Thousands of reads were obtained for each gene with multiple overlapping fragments, which were assembled to generate full-length (typically >2 kb), high-quality sequences. Phytoplasma groups and subgroups were accurately determined based on 16S ribosomal RNA and cpn60 gene sequences. Hybridization-based MLST facilitates the enrichment of target genes of phytoplasmas and allows the simultaneous determination of sequences corresponding to seven different markers. In this proof-of-concept study, hybridization-based MLST was demonstrated to be an efficient way to generate data regarding ‘Ca. Phytoplasma’ species/strain differentiation.

Peter Kropotkin (1842–1921) is well known as an anarchist intellectual, an amiable mass of contradictions who loved humanity and was highly regarded in academic and intellectual circles, yet also penned “fiery peans to violence” in Le Révolté, the anarchist journal he established with Elisée Reclus in the 1870s [...]

DUX4 is the major gene responsible for facioscapulohumeral dystrophy (FSHD). Several mouse models expressing DUX4 have been developed, the most commonly used by academic laboratories being ACTA1-MCM/FLExDUX4. In this study, molecular and histological modifications in the tibialis anterior and quadriceps muscles were investigated in this model at different time points. We investigated several changes that could be used as markers of therapeutic efficacy. Our results confirm the progressive muscular dystrophy previously described but also highlight biases associated with tamoxifen injections and the complexity of choosing the genes used to calculate a DUX4-pathway gene composite score. We also developed a comprehensive force test that better reflects the movements made in everyday life. This functional force–velocity–endurance model, which describes the force production capacities at all velocity and fatigue levels, was applied on 12–13-week-old animals without tamoxifen. Our data highlight that previously unsuspected muscle properties are also affected by the expression of DUX4, leading to a weaker muscle with a lower initial muscle force but with preserved power and endurance capacity. Importantly, this force–velocity–endurance approach can be used in humans for clinical evaluations. [ABSTRACT FROM AUTHOR]

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening syndrome that can occur either in genetically predisposed individuals (primary HLH) or in particular conditions in immunocompromised patients (secondary HLH). Secondary HLH is very rare among solid organ transplant recipients, especially in lung transplant recipients, for whom its prognosis is dismal. Case Report: We report an exceptional case of HLH occurring unusually late following lung transplantation. At 11 years after transplantation, the patient, aged 67 years, presented with pancytopenia, fever, hyperferritinemia, and hypertriglyceridemia, along with splenomegaly. Exhaustive serological and PCR tests ruled out active infection. Bone marrow aspirates showed signs of hemophagocytosis, and bone marrow biopsy was suggestive of posttransplant lymphoproliferative disorder (PTLD). Timely treatment with etoposide and corticosteroids led to a transient improvement in the patient's clinical condition, and rituximab was initiated as a treatment for PTLD. Unfortunately, pancytopenia persisted for weeks, and the patient died from refractory septic shock, despite appropriate intravenous antibiotics. Autopsy revealed lymphoid infiltration of the mediastinal lymph nodes, liver and bone marrow, with some lymphocytes expressing CD3. A final diagnosis of Ann-Arbor stage IV non-EBVmediated monomorphic T-cell PTLD was established. Conclusions: This case report highlights a very unusual and fatal presentation of HLH in a lung transplant recipient, secondary to a T-cell PTLD. Indeed, HLH is typically seen as infection-related and reported to occur in the initial months following transplantation. To date, no guidelines or consensus exist regarding the management of immunosuppression regimen in solid organ transplantation. [ABSTRACT FROM AUTHOR]

Motivation State-of-the-art tools for classifying metagenomic sequencing reads provide both rapid and accurate options, although the combination of both in a single tool is a constantly improving area of research. The machine learning-based Naïve Bayes Classifier (NBC) approach provides a theoretical basis for accurate classification of all reads in a sample. Results We developed the multithreaded Minimizer-based Naïve Bayes Classifier (MNBC) tool to improve the NBC approach by applying minimizers, as well as plurality voting for closely related classification scores. A standard reference- and test-sequence framework using simulated variable-length reads benchmarked MNBC with six other state-of-the-art tools: MetaMaps, Ganon, Kraken2, KrakenUniq, CLARK, and Centrifuge. We also applied MNBC to the "marine" and "strain-madness" short-read metagenomic datasets in the Critical Assessment of Metagenome Interpretation (CAMI) II challenge using a corresponding database from the time. MNBC efficiently identified reads from unknown microorganisms, and exhibited the highest species- and genus-level precision and recall on short reads, as well as the highest species-level precision on long reads. It also achieved the highest accuracy on the "strain-madness" dataset. Availability and implementation MNBC is freely available at: https://github.com/ComputationalPathogens/MNBC. [ABSTRACT FROM AUTHOR]

Facioscapulohumeral dystrophy (FSHD) is a skeletal muscle disease caused by the aberrant expression of the DUX4 gene in the muscle tissue. To date, different therapeutic approaches have been proposed, targeting DUX4 at the DNA, RNA or protein levels. The recent development of the clustered regularly interspaced short-palindromic repeat (CRISPR) based technology opened new avenues of research, and FSHD is no exception. For the first time, a cure for genetic muscular diseases can be considered. Here, we describe CRISPR-based strategies that are currently being investigated for FSHD. The different approaches include the epigenome editing targeting the DUX4 gene and its promoter, gene editing targeting the polyadenylation of DUX4 using TALEN, CRISPR/cas9 or adenine base editing and the CRISPR-Cas9 genome editing for SMCHD1. We also discuss challenges facing the development of these gene editing based therapeutics.

Abstract Background Spinal muscular atrophy (SMA) is caused by genetic defects in the survival motor neuron 1 (SMN1) gene that lead to SMN deficiency. Different SMN‐restoring therapies substantially prolong survival and function in transgenic mice of SMA. However, these therapies do not entirely prevent muscle atrophy and restore function completely. To further improve the outcome, we explored the potential of a combinatorial therapy by modulating SMN production and muscle‐enhancing approach as a novel therapeutic strategy for SMA. Methods The experiments were performed in a mouse model of severe SMA. A previously reported 25‐mer morpholino antisense oligomer PMO25 was used to restore SMN expression. The adeno‐associated virus‐mediated expression of myostatin propeptide was used to block the myostatin pathway. Newborn SMA mice were treated with a single subcutaneous injection of 40 μg/g (therapeutic dose) or 10 μg/g (low‐dose) PMO25 on its own or together with systemic delivery of a single dose of adeno‐associated virus‐mediated expression of myostatin propeptide. The multiple effects of myostatin inhibition on survival, skeletal muscle phenotype, motor function, neuromuscular junction maturation, and proprioceptive afferences were evaluated. Results We show that myostatin inhibition acts synergistically with SMN‐restoring antisense therapy in SMA mice treated with the higher therapeutic dose PMO25 (40 μg/g), by increasing not only body weight (21% increase in male mice at Day 40), muscle mass (38% increase), and fibre size (35% increase in tibialis anterior muscle in 3 month female SMA mice), but also motor function and physical performance as measured in hanging wire test (two‐fold increase in time score) and treadmill exercise test (two‐fold increase in running distance). In SMA mice treated with low‐dose PMO25 (10 μg/g), the early application of myostatin inhibition prolongs survival (40% increase), improves neuromuscular junction maturation (50% increase) and innervation (30% increase), and increases both the size of sensory neurons in dorsal root ganglia (60% increase) and the preservation of proprioceptive synapses in the spinal cord (30% increase). Conclusions These data suggest that myostatin inhibition, in addition to the well‐known effect on muscle mass, can also positively influence the sensory neural circuits that may enhance motor neurons function. While the availability of the antisense drug Spinraza for SMA and other SMN‐enhancing therapies has provided unprecedented improvement in SMA patients, there are still unmet needs in these patients. Our study provides further rationale for considering myostatin inhibitors as a therapeutic intervention in SMA patients, in combination with SMN‐restoring drugs.

ABSTRACT Detection of bacterial DNA within meconium is often cited as evidence supporting in utero colonization. However, many studies fail to adequately control for contamination. We aimed to define the microbial content of meconium under properly controlled conditions. DNA was extracted from 141 meconium samples and subjected to cpn60-based microbiome profiling, with controls to assess contamination throughout. Total bacterial loads of neonatal meconium, infant stool, and controls were compared by 16S rRNA quantitative PCR (qPCR). Viable bacteria within meconium were cultured, and isolate clonality was assessed by pulsed-field gel electrophoresis (PFGE). Meconium samples did not differ significantly from controls with respect to read numbers or taxonomic composition. Twenty (14%) outliers with markedly higher read numbers were collected significantly later after birth and appeared more like transitional stool than meconium. Total bacterial loads were significantly higher in stool than in meconium, which did not differ from that of sequencing controls, and correlated well with read numbers. Cultured isolates were most frequently identified as Staphylococcus epidermidis, Enterococcus faecalis, or Escherichia coli, with PFGE indicating high intraspecies diversity. Our findings highlight the importance of robust controls in studies of low microbial biomass samples and argue against meaningful bacterial colonization in utero. Given that meconium microbiome profiles could not be distinguished from sequencing controls, and that viable bacteria within meconium appeared uncommon and largely consistent with postnatal skin colonization, there does not appear to be a meconium microbiota. IMPORTANCE Much like the recent placental microbiome controversy, studies of neonatal meconium reporting bacterial communities within the fetal and neonatal gut imply that microbial colonization begins prior to birth. However, recent work has shown that placental microbiomes almost exclusively represent contamination from lab reagents and the environment. Here, we demonstrate that prior studies of neonatal meconium are impacted by the same issue, showing that the microbial content of meconium does not differ from negative controls that have never contained any biological material. Our culture findings similarly supported this notion and largely comprised bacteria normally associated with healthy skin. Overall, our work adds to the growing body of evidence against the in utero colonization hypothesis.

Clinical trials with treatments inhibiting myostatin pathways to increase muscle mass are currently ongoing in spinal muscular atrophy. Given evidence of potential myostatin pathway downregulation in Spinal Muscular Atrophy (SMA), restoring sufficient myostatin levels using disease-modifying treatments (DMTs) might arguably be necessary prior to considering myostatin inhibitors as an add-on treatment. This retrospective study assessed pre-treatment myostatin and follistatin levels' correlation with disease severity and explored their alteration by disease-modifying treatment in SMA. We retrospectively collected clinical characteristics, motor scores, and mysotatin and follistatin levels between 2018 and 2020 in 25 Belgian patients with SMA (SMA1 (n = 13), SMA2 (n = 6), SMA 3 (n = 6)) and treated by nusinersen. Data were collected prior to treatment and after 2, 6, 10, 18, and 30 months of treatment. Myostatin levels correlated with patients' age, weight, SMA type, and motor function before treatment initiation. After treatment, we observed correlations between myostatin levels and some motor function scores (i.e., MFM32, HFMSE, 6MWT), but no major effect of nusinersen on myostatin or follistatin levels over time. In conclusion, further research is needed to determine if DMTs can impact myostatin and follistatin levels in SMA, and how this could potentially influence patient selection for ongoing myostatin inhibitor trials. [ABSTRACT FROM AUTHOR]

Steam explosion pretreatment of sawdust and oat straw under mild, medium, and severe conditions was conducted to improve the quality of pellets generated from these feedstocks. This work examined the effects of temperature, time, and moisture content on the mechanical properties of biomass pellets. From the ANOVA conducted, the p-values of the regression models for all the response variables (dimensional stability, tensile strength, and pellet density) studied were significant (p < 0.05), except for the pellet density of steam-pretreated oat straw pellets. The interaction of these three factors did not significantly affect the response variables of oat straw pellets. In addition, the higher heating value (HHV) of treated biomass increased up to a maximum of about 9.5% and 7% as compared with the non-treated sawdust and oat straw, respectively. In addition, an increment of about 3.6-fold and 3.1-fold in pellet tensile strength of steam-pretreated sawdust and oat straw was observed, respectively. Microstructural examination of the pellets from steam-pretreated biomass revealed that the material contained particles that were more closely bonded and featured a cemented surface with fewer pores when compared to particles from untreated oat straw and sawdust.