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1.
Neurotrauma Rep ; 4(1): 781-789, 2023.
Article En | MEDLINE | ID: mdl-38028277

Open data sharing of clinical research aims to improve transparency and support novel scientific discoveries. There are also risks, including participant identification and the potential for stigmatization. The perspectives of persons participating in research are needed to inform open data-sharing policies. The aim of the current study was to determine perspectives on data sharing in persons with spinal cord injury (SCI), including risks and benefits, and types of data people are most willing to share. A secondary aim was to examine predictors of willingness to share data. Persons with SCIs in the United States and Canada completed a survey developed and disseminated through various channels, including our community partner, the North American Spinal Cord Injury Consortium. The study collected data from 232 participants, with 52.2% from Canada and 42.2% from the United States, and the majority completed the survey in English. Most participants had previously participated in research and had been living with an SCI for ≥5 years. Overall, most participants reported that the potential benefits of data sharing outweighed the negatives, with persons with SCI seen as the most trustworthy partners for data sharing. The highest levels of concern were that information could be stolen and companies might use the information for marketing purposes. Persons with SCI were generally supportive of data sharing for research purposes. Clinical trials should consider including a statement on open data sharing in informed consents to better acknowledge the contribution of research participants in future studies.

2.
J Spinal Cord Med ; : 1-7, 2023 Mar 28.
Article En | MEDLINE | ID: mdl-36975605

CONTEXT/OBJECTIVE: The risk for cardiovascular disease is amplified following spinal cord injury, but whether risk differs between the sexes remains unknown. Here, we evaluated sex differences in the prevalence of heart disease among individuals with spinal cord injury, and compared sex differences with able-bodied individuals. DESIGN: The design was a cross-sectional study. Multivariable logistic regression analysis was conducted, using inverse probability weighting to account for the sampling method and to adjust for confounders. SETTING: Canada. PARTICIPANTS: Individuals who participated in the national Canadian Community Health Survey. INTERVENTIONS: Not applicable. OUTCOME MEASURES: Self-reported heart disease. RESULTS: Among 354 individuals with spinal cord injury, the weighted prevalence of self-reported heart disease was 22.9% in males and 8.7% in females, with an inverse-probability weighted odds ratio of 3.44 (95% CI 1.70-6.95) for males versus females. Among 60,605 able-bodied individuals, the prevalence of self-reported heart disease was 5.8% in males and 4.0% in females, with an inverse probability weighted odds ratio of 1.62 (95% CI 1.50-1.75) for males versus females. The effect of male sex on increasing heart disease prevalence was about two times higher among individuals with spinal cord injury than able-bodied individuals (relative difference in inverse probability weighted odds ratios = 2.12, 95% CI 1.08-4.51). CONCLUSION: Males with spinal cord injury exhibit a significantly higher prevalence of heart disease, compared with females with spinal cord injury. Moreover, relative to able-bodied individuals, spinal cord injury amplifies sex-related differences in heart disease. Overall, this work will inform targeted cardiovascular prevention strategies, and may also inform a better understanding of cardiovascular disease progression in both able-bodied and individuals with spinal cord injury.

3.
Environ Microbiol ; 25(8): 1484-1504, 2023 08.
Article En | MEDLINE | ID: mdl-36912501

Dietary fibre is a major energy source for the human gut microbiota, but it is unclear to what extent the fibre source and complexity affect microbial growth and metabolite production. Cell wall material and pectin were extracted from five different dicotyledon plant sources, apples, beet leaves, beetroots, carrots and kale, and compositional analysis revealed differences in the monosaccharide composition. Human faecal batch incubations were conducted with 14 different substrates, including the plant extracts, wheat bran and commercially available carbohydrates. Microbial activity was determined for up to 72 h by measuring gas and fermentation acid production, total bacteria (by qPCR) and microbial community composition by 16S rRNA amplicon sequencing. The more complex substrates gave rise to more microbiota variation compared with the pectins. The comparison of different plant organs showed that the leaves (beet leaf and kale) and roots (carrot and beetroot) did not give rise to similar bacterial communities. Rather, the compositional features of the plants, such as high arabinan levels in beet and high galactan levels in carrot, appear to be major predictors of bacterial enrichment on the substrates. Thus, in-depth knowledge on dietary fibre composition should aid the design of diets focused on optimizing the microbiota.


Gastrointestinal Microbiome , Microbiota , Humans , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 16S/metabolism , Dietary Fiber/metabolism , Bacteria , Feces/microbiology , Fermentation , Pectins/metabolism
4.
Sci Rep ; 12(1): 14631, 2022 08 27.
Article En | MEDLINE | ID: mdl-36030282

Reflecting the first wave COVID-19 pandemic in Central Europe (i.e. March 16th-April 15th, 2020) the neurosurgical community witnessed a general diminution in the incidence of emergency neurosurgical cases, which was impelled by a reduced number of traumatic brain injuries (TBI), spine conditions, and chronic subdural hematomas (CSDH). This appeared to be associated with restrictions imposed on mobility within countries but also to possible delayed patient introduction and interdisciplinary medical counseling. In response to one year of COVID-19 experience, also mapping the third wave of COVID-19 in 2021 (i.e. March 16 to April 15, 2021), we aimed to reevaluate the current prevalence and outcomes for emergency non-elective neurosurgical cases in COVID-19-negative patients across Austria and the Czech Republic. The primary analysis was focused on incidence and 30-day mortality in emergency neurosurgical cases compared to four preceding years (2017-2020). A total of 5077 neurosurgical emergency cases were reviewed. The year 2021 compared to the years 2017-2019 was not significantly related to any increased odds of 30 day mortality in Austria or in the Czech Republic. Recently, there was a significant propensity toward increased incidence rates of emergency non-elective neurosurgical cases during the third COVID-19 pandemic wave in Austria, driven by their lower incidence during the first COVID-19 wave in 2020. Selected neurosurgical conditions commonly associated with traumatic etiologies including TBI, and CSDH roughly reverted to similar incidence rates from the previous non-COVID-19 years. Further resisting the major deleterious effects of the continuing COVID-19 pandemic, it is edifying to notice that the neurosurgical community´s demeanor to the recent third pandemic culmination keeps the very high standards of non-elective neurosurgical care alongside with low periprocedural morbidity. This also reflects the current state of health care quality in the Czech Republic and Austria.


COVID-19 , Hematoma, Subdural, Chronic , Europe , Humans , Neurosurgical Procedures , Pandemics
5.
Reg Anesth Pain Med ; 47(4): 263-269, 2022 04.
Article En | MEDLINE | ID: mdl-35027479

BACKGROUND: In an attempt to aggregate observations from clinical trials, several meta-analyses have been published examining the effectiveness of systemic, non-opioid, pharmacological interventions to reduce the incidence of chronic postsurgical pain. OBJECTIVE: To inform the design and reporting of future studies, the purpose of our study was to examine the quality of these meta-analyses. EVIDENCE REVIEW: We conducted an electronic literature search in Embase, MEDLINE, and the Cochrane Database of Systematic Reviews. Published meta-analyses, from the years 2010 to 2020, examining the effect of perioperative, systemic, non-opioid pharmacological treatments on the incidence of chronic postsurgical pain in adult patients were identified. Data extraction focused on methodological details. Meta-analysis quality was assessed using the A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) critical appraisal tool. FINDINGS: Our search yielded 17 published studies conducting 58 meta-analyses for gabapentinoids (gabapentin and pregabalin), ketamine, lidocaine, non-steroidal anti-inflammatory drugs, and mexiletine. According to AMSTAR 2, 88.2% of studies (or 15/17) were low or critically low in quality. The most common critical element missing was an analysis of publication bias. Trends indicated an improvement in quality over time and association with journal impact factor. CONCLUSIONS: With few individual trials adequately powered to detect treatment effects, meta-analyses play a crucial role in informing the perioperative management of chronic postsurgical pain. In light of this inherent value and despite a number of attempts, high-quality meta-analyses are still needed. PROSPERO REGISTRATION NUMBER: CRD42021230941.


Chronic Pain , Ketamine , Adult , Chronic Pain/diagnosis , Chronic Pain/drug therapy , Gabapentin , Humans , Ketamine/therapeutic use , Pain, Postoperative/diagnosis , Pain, Postoperative/drug therapy , Pain, Postoperative/etiology , Pregabalin
6.
Am J Respir Crit Care Med ; 205(6): 641-650, 2022 03 15.
Article En | MEDLINE | ID: mdl-34919021

Rationale: In murine models, microbial exposures induce protection from experimental allergic asthma through innate immunity. Objectives: Our aim was to assess the association of early life innate immunity with the development of asthma in children at risk. Methods: In the PASTURE farm birth cohort, innate T-helper cell type 2 (Th2), Th1, and Th17 cytokine expression at age 1 year was measured after stimulation of peripheral blood mononuclear cells with LPS in n = 445 children. Children at risk of asthma were defined based on single-nucleotide polymorphisms at the 17q21 asthma gene locus. Specifically, we used the SNP rs7216389 in the GSDMB gene. Wheeze in the first year of life was assessed by weekly diaries and asthma by questionnaire at age 6 years. Measurements and Main Results: Not all cytokines were detectable in all children after LPS stimulation. When classifying detectability of cytokines by latent class analysis, carrying the 17q21 risk allele rs7216389 was associated with risk of wheeze only in the class with the lowest level of LPS-induced activation: odds ratio (OR), 1.89; 95% confidence interval [CI], 1.13-3.16; P = 0.015. In contrast, in children with high cytokine activation after LPS stimulation, no association of the 17q21 risk allele with wheeze (OR, 0.63; 95% CI, 0.29-1.40; P = 0.258, P = 0.034 for interaction) or school-age asthma was observed. In these children, consumption of unprocessed cow's milk was associated with higher cytokine activation (OR, 3.37; 95% CI, 1.56-7.30; P = 0.002), which was in part mediated by the gut microbiome. Conclusions: These findings suggest that within the 17q21 genotype, asthma risk can be mitigated by activated immune responses after innate stimulation, which is partly mediated by a gut-immune axis.


Asthma , Chromosomes, Human, Pair 17 , Lipopolysaccharides , Alleles , Animals , Asthma/genetics , Cattle , Cytokines/genetics , Female , Humans , Immunity, Innate , Leukocytes, Mononuclear , Mice , Respiratory Sounds/genetics
7.
Spinal Cord ; 59(12): 1256-1260, 2021 Dec.
Article En | MEDLINE | ID: mdl-34480090

STUDY DESIGN: Article. OBJECTIVE: ClinicalTrials.gov is an online trial registry that provides public access to information on past, present, and future clinical trials. While increasing transparency in research, the quality of the information provided in trial registrations is highly variable. The objective of this study is to assess key areas of information on ClinicalTrials.gov in interventional trials involving people with spinal cord injuries. SETTING: Interventional trials on ClinicalTrials.gov involving people with spinal cord injuries. METHODS: A subset of data on interventional spinal cord injury trials was downloaded from ClinicalTrials.gov. Reviewers extracted information pertaining to study type, injury etiology, spinal cord injury characteristics, timing, study status, and results. RESULTS: Of the interventional trial registrations reviewed, 62.5%, 58.6%, and 24.3% reported injury level, severity, and etiology, respectively. The timing of intervention relative to injury was reported in 72.8% of registrations. Most trials identified a valid study status (89.2%), but only 23.5% of those completed studies had posted results. CONCLUSIONS: Our review provides a snapshot of interventional clinical trials conducted in the field of spinal cord injury and registered in ClinicalTrials.gov. Areas for improvement were identified with regards to reporting injury characteristics, as well as posting results.


Clinical Trials as Topic , Spinal Cord Injuries , Humans , Registries , Spinal Cord Injuries/epidemiology , Spinal Cord Injuries/therapy
8.
Clin Nutr ; 40(8): 5009-5019, 2021 08.
Article En | MEDLINE | ID: mdl-34364241

BACKGROUND & AIMS: Siblings of people with Crohn's disease (CD) share aspects of the disease phenotype (raised faecal calprotectin, altered microbiota), which are markers of risk for their own development of CD. The aim was to determine whether supplementation with prebiotic oligofructose/inulin induces a prebiotic response and impacts the risk phenotype in CD patients and siblings. METHODS: Patients with inactive CD (n = 19, CD activity index <150) and 12 of their unaffected siblings (with calprotectin >50 µg/g) ingested oligofructose/inulin (15 g/day) for three weeks. Faecal microbiota (qPCR), intestinal permeability (lactulose-rhamnose test), blood T cells (flow-cytometry) and calprotectin (ELISA) were measured at baseline and follow-up. RESULTS: Following oligofructose/inulin, calprotectin did not significantly change in patients (baseline mean 537 SD 535 µg/g; follow-up mean 974 SD 1318 µg/g, p = 0.08) or siblings (baseline mean 73 SD 90 µg/g: follow up mean 58 SD 72 µg/g, p = 0.62). Faecal Bifidobacteria and Bifidobacterium longum increased in patients and siblings; Bifidobacterium adolescentis and Roseburia spp. increased only in siblings. Compared with patients, siblings had a greater magnitude change in Bifidobacteria (+14.6% vs +0.4%, p = 0.028), B. adolescentis (+1.1% vs 0.0% p = 0.006) and Roseburia spp. (+1.5% vs -0.1% p = 0.004). Intestinal permeability decreased significantly in patients after oligofructose/inulin to a level that was similar to siblings. Blood T cell abundance reduced in siblings but not patients following oligofructose/inulin. CONCLUSIONS: Oligofructose/inulin supplementation did not significantly impact calprotectin, but the prebiotic effect was more marked in healthy siblings compared with patients with inactive CD and was associated with alterations in other CD risk markers. Future research should focus on dietary intervention, including with prebiotics, in the primary prevention of CD.


Crohn Disease/microbiology , Crohn Disease/prevention & control , Fructans/administration & dosage , Prebiotics/administration & dosage , Siblings , Adolescent , Adult , Feces/chemistry , Feces/microbiology , Female , Flow Cytometry , Healthy Volunteers , Humans , Intestines/microbiology , Inulin/administration & dosage , Leukocyte L1 Antigen Complex/analysis , Male , Oligosaccharides/administration & dosage , Permeability , Phenotype , Pilot Projects , T-Lymphocytes/microbiology , Young Adult
9.
Sci Rep ; 11(1): 6171, 2021 03 17.
Article En | MEDLINE | ID: mdl-33731753

The world currently faces the novel severe acute respiratory syndrome coronavirus 2 pandemic. Little is known about the effects of a pandemic on non-elective neurosurgical practices, which have continued under modified conditions to reduce the spread of COVID-19. This knowledge might be critical for the ongoing second coronavirus wave and potential restrictions on health care. We aimed to determine the incidence and 30-day mortality rate of various non-elective neurosurgical procedures during the COVID-19 pandemic. A retrospective, multi-centre observational cohort study among neurosurgical centres within Austria, the Czech Republic, and Switzerland was performed. Incidence of neurosurgical emergencies and related 30-day mortality rates were determined for a period reflecting the peak pandemic of the first wave in all participating countries (i.e. March 16th-April 15th, 2020), and compared to the same period in prior years (2017, 2018, and 2019). A total of 4,752 emergency neurosurgical cases were reviewed over a 4-year period. In 2020, during the COVID-19 pandemic, there was a general decline in the incidence of non-elective neurosurgical cases, which was driven by a reduced number of traumatic brain injuries, spine conditions, and chronic subdural hematomas. Thirty-day mortality did not significantly increase overall or for any of the conditions examined during the peak of the pandemic. The neurosurgical community in these three European countries observed a decrease in the incidence of some neurosurgical emergencies with 30-day mortality rates comparable to previous years (2017-2019). Lower incidence of neurosurgical cases is likely related to restrictions placed on mobility within countries, but may also involve delayed patient presentation.


COVID-19/mortality , Neurosurgical Procedures/mortality , Neurosurgical Procedures/trends , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Europe , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Neurosurgery/methods , Pandemics/statistics & numerical data , Retrospective Studies , Young Adult
10.
Expert Opin Drug Saf ; 20(1): 1-8, 2021 Jan.
Article En | MEDLINE | ID: mdl-33170749

INTRODUCTION: The use of observational data to assess drug effectiveness and safety can provide relevant information, much of which may not be feasible to obtain through randomized clinical trials. Because observational studies provide critical drug safety and effectiveness information that influences drug policy and prescribing practices, transparent, consistent, and accurate reporting of these studies is critical. AREAS COVERED: We provide recommendations to extend existing reporting guidelines, covering the main components of primary research studies (methods, results, discussion). EXPERT OPINION: Our recommendations include extending drug safety and effectiveness guidelines to include explicit checklist items on: study registration, causal diagrams, rationale for measures of effect, comprehensive assessment of bias, comprehensive data cleaning steps, drug equivalents, subject-level drug data visualization, sex and gender-based analyses and results, patient-oriented outcomes, and patient involvement in research.


Drug-Related Side Effects and Adverse Reactions/epidemiology , Guidelines as Topic , Observational Studies as Topic/standards , Research Design , Bias , Checklist , Humans , Pharmaceutical Preparations/administration & dosage
11.
Nat Med ; 26(11): 1766-1775, 2020 11.
Article En | MEDLINE | ID: mdl-33139948

Growing up on a farm is associated with an asthma-protective effect, but the mechanisms underlying this effect are largely unknown. In the Protection against Allergy: Study in Rural Environments (PASTURE) birth cohort, we modeled maturation using 16S rRNA sequence data of the human gut microbiome in infants from 2 to 12 months of age. The estimated microbiome age (EMA) in 12-month-old infants was associated with previous farm exposure (ß = 0.27 (0.12-0.43), P = 0.001, n = 618) and reduced risk of asthma at school age (odds ratio (OR) = 0.72 (0.56-0.93), P = 0.011). EMA mediated the protective farm effect by 19%. In a nested case-control sample (n = 138), we found inverse associations of asthma with the measured level of fecal butyrate (OR = 0.28 (0.09-0.91), P = 0.034), bacterial taxa that predict butyrate production (OR = 0.38 (0.17-0.84), P = 0.017) and the relative abundance of the gene encoding butyryl-coenzyme A (CoA):acetate-CoA-transferase, a major enzyme in butyrate metabolism (OR = 0.43 (0.19-0.97), P = 0.042). The gut microbiome may contribute to asthma protection through metabolites, supporting the concept of a gut-lung axis in humans.


Asthma/epidemiology , Butyrates/metabolism , Coenzyme A-Transferases/genetics , Gastrointestinal Microbiome/genetics , Adolescent , Asthma/genetics , Asthma/microbiology , Asthma/pathology , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Butyrates/isolation & purification , Child , Feces/chemistry , Female , Humans , Infant , Lung/metabolism , Lung/pathology , Male , RNA, Ribosomal, 16S/genetics
12.
Neurology ; 95(24): e3412-e3419, 2020 12 15.
Article En | MEDLINE | ID: mdl-32989101

OBJECTIVE: To explore the hypothesis that earlier administration of acute gabapentinoids is beneficial to motor recovery after spinal cord injury in humans. METHODS: This is an observational study using a cohort from the European Multi-Centre Study about Spinal Cord Injury. Patient charts were reviewed to extract information regarding the administration and timing of gabapentinoid anticonvulsants. The primary outcome measure was motor scores, as measured by the International Standards for Neurological Classification of Spinal Cord Injury, collected longitudinally in the first year after injury. Sensory scores (light touch and pinprick) and functional measures (Spinal Cord Independence Measure) were secondary outcomes. Linear mixed effects regression models included a drug-by-time interaction to determine whether exposure to gabapentinoids altered recovery of muscle strength in the first year after injury. RESULTS: A total of 201 participants were included in the study and had a median age of 46 and baseline motor score of 50. Participants were mostly men (85%) with sensory and motor complete injuries (50%). Seventy individuals (35%) were administered gabapentinoids within the first 30 days after injury, and presented with similar demographics. In the longitudinal model, the administration of gabapentinoids within 30 days after injury was associated with improved motor recovery when compared to those who did not receive gabapentinoids during this time (3.69 additional motor points from 4 to 48 weeks after injury; p = 0.03). This effect size increased as administration occurred earlier after injury (i.e., a benefit of 4.68 points when administered within 5 days). CONCLUSIONS: This retrospective, observational study provided evidence of the beneficial effect of gabapentinoid anticonvulsants on motor recovery after spinal cord injury. More critically, it highlighted a potential time dependence, suggesting that earlier intervention is associated with better outcomes. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that gabapentinoids improve motor recovery for individuals with acute spinal cord injury.


Anticonvulsants/administration & dosage , GABA Agents/administration & dosage , Outcome Assessment, Health Care , Recovery of Function/drug effects , Spinal Cord Injuries/drug therapy , Spinal Cord Injuries/physiopathology , Adult , Female , Humans , Longitudinal Studies , Male , Middle Aged , Severity of Illness Index
13.
mSystems ; 5(5)2020 Sep 08.
Article En | MEDLINE | ID: mdl-32900872

Lactate can be produced by many gut bacteria, but in adults its accumulation in the colon is often an indicator of microbiota perturbation. Using continuous culture anaerobic fermentor systems, we found that lactate concentrations remained low in communities of human colonic bacteria maintained at pH 6.5, even when dl-lactate was infused at 10 or 20 mM. In contrast, lower pH (5.5) led to periodic lactate accumulation following lactate infusion in three fecal microbial communities examined. Lactate accumulation was concomitant with greatly reduced butyrate and propionate production and major shifts in microbiota composition, with Bacteroidetes and anaerobic Firmicutes being replaced by Actinobacteria, lactobacilli, and Proteobacteria Pure-culture experiments confirmed that Bacteroides and Firmicutes isolates were susceptible to growth inhibition by relevant concentrations of lactate and acetate, whereas the lactate-producer Bifidobacterium adolescentis was resistant. To investigate system behavior further, we used a mathematical model (microPop) based on 10 microbial functional groups. By incorporating differential growth inhibition, our model reproduced the chaotic behavior of the system, including the potential for lactate infusion both to promote and to rescue the perturbed system. The modeling revealed that system behavior is critically dependent on the proportion of the community able to convert lactate into butyrate or propionate. Communities with low numbers of lactate-utilizing bacteria are inherently less stable and more prone to lactate-induced perturbations. These findings can help us to understand the consequences of interindividual microbiota variation for dietary responses and microbiota changes associated with disease states.IMPORTANCE Lactate is formed by many species of colonic bacteria, and can accumulate to high levels in the colons of inflammatory bowel disease subjects. Conversely, in healthy colons lactate is metabolized by lactate-utilizing species to the short-chain fatty acids butyrate and propionate, which are beneficial for the host. Here, we investigated the impact of continuous lactate infusions (up to 20 mM) at two pH values (6.5 and 5.5) on human colonic microbiota responsiveness and metabolic outputs. At pH 5.5 in particular, lactate tended to accumulate in tandem with decreases in butyrate and propionate and with corresponding changes in microbial composition. Moreover, microbial communities with low numbers of lactate-utilizing bacteria were inherently less stable and therefore more prone to lactate-induced perturbations. These investigations provide clear evidence of the important role these lactate utilizers may play in health maintenance. These should therefore be considered as potential new therapeutic probiotics to combat microbiota perturbations.

14.
Cancer Epidemiol Biomarkers Prev ; 29(10): 2093-2095, 2020 10.
Article En | MEDLINE | ID: mdl-32699076

BACKGROUND: Tattoos may cause a variety of adverse reactions in the body, including immune reactions and infections. However, it is unknown whether tattoos may increase the risk of lymphatic cancers such as non-Hodgkin lymphoma (NHL) and multiple myeloma. METHODS: Participants from two population-based case-control studies were included in logistic regression models to examine the association between tattoos and risk of NHL and multiple myeloma. RESULTS: A total of 1,518 participants from the NHL study (737 cases) and 742 participants from the multiple myeloma study (373 cases) were included in the analyses. No statistically significant associations were found between tattoos and risk of NHL or multiple myeloma after adjusting for age, sex, ethnicity, education, body mass index, and family history. CONCLUSIONS: We did not identify any significant associations between tattoos and risk of multiple myeloma, NHL, or NHL subtypes in these studies. IMPACT: Though biologically plausible, tattoos were not associated with increased risk of NHL or multiple myeloma in this study. Future studies with greater detail regarding tattoo exposure may provide further insights.


Hematologic Neoplasms/etiology , Tattooing/adverse effects , British Columbia , Canada , Female , Hematologic Neoplasms/physiopathology , Humans , Male
15.
mBio ; 11(4)2020 07 14.
Article En | MEDLINE | ID: mdl-32665271

We investigated the requirement of 15 human butyrate-producing gut bacterial strains for eight B vitamins and the proteinogenic amino acids by a combination of genome sequence analysis and in vitro growth experiments. The Ruminococcaceae species Faecalibacterium prausnitzii and Subdoligranulum variabile were auxotrophic for most of the vitamins and the amino acid tryptophan. Within the Lachnospiraceae, most species were prototrophic for all amino acids and several vitamins, but biotin auxotrophy was widespread. In addition, most of the strains belonging to Eubacterium rectale and Roseburia spp., but few of the other Lachnospiraceae strains, were auxotrophic for thiamine and folate. Synthetic coculture experiments of five thiamine or folate auxotrophic strains with different prototrophic bacteria in the absence and presence of different vitamin concentrations were carried out. This demonstrated that cross-feeding between bacteria does take place and revealed differences in cross-feeding efficiency between prototrophic strains. Vitamin-independent growth stimulation in coculture compared to monococulture was also observed, in particular for F. prausnitzii A2-165, suggesting that it benefits from the provision of other growth factors from community members. The presence of multiple vitamin auxotrophies in the most abundant butyrate-producing Firmicutes species found in the healthy human colon indicates that these bacteria depend upon vitamins supplied from the diet or via cross-feeding from other members of the microbial community.IMPORTANCE Microbes in the intestinal tract have a strong influence on human health. Their fermentation of dietary nondigestible carbohydrates leads to the formation of health-promoting short-chain fatty acids, including butyrate, which is the main fuel for the colonic wall and has anticarcinogenic and anti-inflammatory properties. A good understanding of the growth requirements of butyrate-producing bacteria is important for the development of efficient strategies to promote these microbes in the gut, especially in cases where their abundance is altered. The demonstration of the inability of several dominant butyrate producers to grow in the absence of certain vitamins confirms the results of previous in silico analyses. Furthermore, establishing that strains prototrophic for thiamine or folate (butyrate producers and non-butyrate producers) were able to stimulate growth and affect the composition of auxotrophic synthetic communities suggests that the provision of prototrophic bacteria that are efficient cross feeders may stimulate butyrate-producing bacteria under certain in vivo conditions.


Bacteria/genetics , Butyrates/metabolism , Fermentation , Microbiota , Vitamins/biosynthesis , Bacteria/metabolism , Clostridiales/genetics , Clostridiales/physiology , Colon/microbiology , Faecalibacterium prausnitzii/genetics , Faecalibacterium prausnitzii/physiology , Humans , Ruminococcus/genetics , Ruminococcus/physiology
16.
Environ Microbiol ; 22(6): 2150-2164, 2020 06.
Article En | MEDLINE | ID: mdl-32141148

A clone encoding carboxymethyl cellulase activity was isolated during functional screening of a human gut metagenomic library using Lactococcus lactis MG1363 as heterologous host. The insert carried a glycoside hydrolase family 9 (GH9) catalytic domain with sequence similarity to a gene from Coprococcus eutactus ART55/1. Genome surveys indicated a limited distribution of GH9 domains among dominant human colonic anaerobes. Genomes of C. eutactus-related strains harboured two GH9-encoding and four GH5-encoding genes, but the strains did not appear to degrade cellulose. Instead, they grew well on ß-glucans and one of the strains also grew on galactomannan, galactan, glucomannan and starch. Coprococcus comes and Coprococcus catus strains did not harbour GH9 genes and were not able to grow on ß-glucans. Gene expression and proteomic analysis of C. eutactus ART55/1 grown on cellobiose, ß-glucan and lichenan revealed similar changes in expression in comparison to glucose. On ß-glucan and lichenan only, one of the four GH5 genes was strongly upregulated. Growth on glucomannan led to a transcriptional response of many genes, in particular a strong upregulation of glycoside hydrolases involved in mannan degradation. Thus, ß-glucans are a major growth substrate for species related to C. eutactus, with glucomannan and galactans alternative substrates for some strains.


Clostridiales/growth & development , Gastrointestinal Microbiome , beta-Glucans , Bacterial Proteins/genetics , Clostridiales/genetics , Gene Expression , Glucans/pharmacology , Glycoside Hydrolases/genetics , Humans , Proteomics
17.
CNS Drugs ; 33(5): 503-511, 2019 05.
Article En | MEDLINE | ID: mdl-30949923

BACKGROUND: Recent observational studies have shown an association between gabapentinoid anticonvulsants and greater motor recovery after spinal cord injury. There is preclinical evidence to suggest that other anticonvulsants, such as sodium channel blockers, may also confer beneficial effects. PURPOSE: The aim of the current study was to determine if non-gabapentinoid anticonvulsants were associated with neurological recovery after acute, traumatic spinal cord injury. METHODS: This was an observational cohort study using data from the Sygen clinical trial. The primary outcome was total motor score recovery in the first year after injury. Anticonvulsant use was extracted from concomitant medication records; individuals were classified based on early administration (within 30 days of injury), or late/no administration. Motor recovery was compared using linear mixed effects regression models with a drug-by-time interaction, and adjustment for confounders. A secondary analysis incorporated a propensity score matched cohort. RESULTS: Of the cohort (n = 570), 6% received anticonvulsants (carbamazepine, phenytoin, clonazepam, phenobarbital, and valproic acid) early after injury. After adjustments for initial injury level and severity, early exposure to non-gabapentinoid anticonvulsants was not associated with motor neurological outcomes (p = 0.38 for all anticonvulsants, p = 0.83 for sodium channel blockers, p = 0.82 in propensity-matched cohort). CONCLUSION: Non-gabapentinoid anticonvulsant exposure was not associated with greater or lesser neurological recovery. This suggests that these medications, as administered for the acute management of spinal cord injury, do not impact long-term neurological outcomes.


Anticonvulsants/pharmacology , Spinal Cord Injuries/drug therapy , Anticonvulsants/administration & dosage , Anticonvulsants/therapeutic use , Cohort Studies , Early Medical Intervention , Humans , Motor Activity/drug effects , Recovery of Function , Trauma Severity Indices , Treatment Outcome
18.
Neurotherapeutics ; 16(3): 858-867, 2019 07.
Article En | MEDLINE | ID: mdl-30725362

The objective of our study was to determine whether treatment with baclofen is neurologically safe with respect to exposure during recovery from spinal cord injury. We performed a secondary longitudinal analysis of a cohort of adult patients with traumatic acute spinal cord injury. Cumulative baclofen dose was computed over the first 4 weeks following injury from concomitant medication information from a completed clinical trial. The main outcome measure was neurologic status, which was assessed over 52 weeks with "marked recovery" defined as the conversion to higher sensory and motor function. To complete the drug safety profile, drug toxicity was assessed with assays from standard blood work. Multivariable Cox regression was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs). Of the cohort (n = 651), 18% (n = 115) received baclofen within 4 weeks post injury. Baclofen use was associated with higher rates of marked neurologic recovery, even after adjustment for injury severity (HR = 2.1, 95% CI 1.5-3.0 for high dose vs none). Baclofen exposure was not associated with liver or renal side effects. The use of other medications indicated for spasticity was not associated with neurological outcomes. Overall, this longitudinal analysis provides level 3 evidence on the neurologic safety of baclofen and potential beneficial effects on recovery in the early days after acute traumatic spinal cord injury. The usefulness of concomitant medication files from completed clinical trials is highlighted. We also highlight the importance of incorporating logical patient questions and neurological outcomes into research addressing drug safety.


Baclofen/therapeutic use , GABA-B Receptor Agonists/therapeutic use , Spinal Cord Injuries/drug therapy , Adult , Baclofen/adverse effects , Female , GABA-B Receptor Agonists/adverse effects , Humans , Longitudinal Studies , Male , Proportional Hazards Models , Recovery of Function , Touch/drug effects
19.
J Neurotrauma ; 36(9): 1461-1468, 2019 05 01.
Article En | MEDLINE | ID: mdl-30417730

The translation of therapeutic interventions to humans with spinal cord injury with the goal of promoting growth and repair in the central nervous system could, inadvertently, drive mechanisms associated with the development of neuropathic pain. A framework is needed to evaluate the probability that a therapeutic intervention for acute spinal cord injury modifies the progression of neuropathic pain. We analyzed a large, longitudinal dataset from the European Multi-Center Study about Spinal Cord Injury (EMSCI) and compared these observations with a previously published Swedish/Danish cohort. A meta-analysis was performed to produce aggregate estimates for the transition period between 1-6 months and the transition period between 1-12 months after injury. A secondary analysis used logistic regression to explore associations between the progression of neuropathic pain and demographics, pain characteristics, and injury characteristics. For overall neuropathic pain, 72% presenting with pain symptoms at one month reported persisting symptoms at six months, and 23% who did not have neuropathic pain at one month later had it develop. From 1-12 months, there was a similar likelihood of pain persisting (69%) and slightly higher rate of pain developing (36%). Characteristics that were significantly associated with the progression of pain included age and sensory and motor preservation. We provide historical benchmarks for estimating the progression of neuropathic pain during the first year after acute SCI. This information will be useful for comparison and evaluating safety during early phase acute spinal cord injury trials.


Disease Progression , Neuralgia/etiology , Spinal Cord Injuries/complications , Humans
20.
J Pain Res ; 11: 901-912, 2018.
Article En | MEDLINE | ID: mdl-29750052

BACKGROUND: Understanding factors associated with high placebo responses in clinical trials increases the likelihood of detecting a meaningful treatment effect. The aim of the present study was to identify subject-level factors that contribute to placebo variability in patients with neuropathic pain due to spinal cord injury (SCI). METHODS: Multiple regression analysis of patient data from randomized, double-blind, placebo-controlled trials (duration >4 weeks) involving individuals with SCI was performed. Patient demographics, as well as injury and pain characteristics were examined for their association with changes in pain rating from baseline to the end of the trial (i.e., placebo response). The overall effect of individual predictors was quantified with meta-analysis statistics. RESULTS: A total of 276 patients with SCI from six studies were included in the analysis. Based on the meta-analysis of subject-level predictors, larger placebo responses were associated with male subjects (ß=0.635; standard error [SE]=0.262; p=0.016) and higher baseline pain (ß=-0.146; SE=0.073; p=0.044). There were no significant effects for injury characteristics (i.e., severity, level, and time since injury) or pain characteristics (i.e., location and evoked). No significant publication bias was detected. CONCLUSION: The current meta-analysis of individual patient data demonstrated the importance of sex and baseline pain intensity on changes in pain ratings in the placebo arm of SCI central neuropathic pain randomized controlled clinical trials. Overall, our findings indicate that placebo responses occur independent of injury characteristics.

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