Investigating adaptive sport participation for adults aged 50 years or older with spinal cord injury or disease: A descriptive cross-sectional survey

CONTEXT

Spinal cord injury or disease (SCI/D) can lead to health challenges that are exacerbated with aging. Adaptive sport is understood to provide health benefits for the SCI/D population. Prior literature investigating adaptive sport in this population pertains to adults with SCI/D who are <50 years of age. However, most Canadians with SCI/D are >50 years of age.

OBJECTIVES

This study aimed to: (1) Compare demographics of those who do and do not participate in adaptive sport; (2) Describe the characteristics of adaptive sport that adults aged ≥50 years with SCI/D participate in; and (3) Identify barriers and facilitators to adaptive sport participation in this age group.

METHODS

This descriptive, cross-sectional survey was carried out using an online survey. Analytical statistics were used to address objective one, while descriptive statistics were employed for objectives two and three.

PARTICIPANTS

Responses from 72 adults aged ≥50 years, residing in Canada, living with a SCI/D for >6 months were included in the analysis.

RESULTS

Findings revealed that adaptive sport participants aged ≥50 years with SCI/D were more likely to identify as men, be younger individuals (50-59 years), and report greater satisfaction with physical health (P < 0.05). Adaptive sport participants most commonly played individual sports at the recreational level. Common barriers pertained to physical capacity, travel, and COVID-19; common facilitators included social support, desire to improve health, and having friends/peers who also participate.

CONCLUSION

Future research should investigate strategies to enhance facilitators and mitigate barriers to adaptive sport participation in order to improve access.

Bioengineering of the Marine Diatom Phaeodactylum tricornutum with Cannabis Genes Enables the Production of the Cannabinoid Precursor, Olivetolic Acid

The increasing demand for novel natural compounds has prompted the exploration of innovative approaches in bioengineering. This study investigates the bioengineering potential of the marine diatom Phaeodactylum tricornutum through the introduction of cannabis genes, specifically, tetraketide synthase (TKS), and olivetolic acid cyclase (OAC), for the production of the cannabinoid precursor, olivetolic acid (OA). P. tricornutum is a promising biotechnological platform due to its fast growth rate, amenability to genetic manipulation, and ability to produce valuable compounds. Through genetic engineering techniques, we successfully integrated the cannabis genes TKS and OAC into the diatom. P. tricornutum transconjugants expressing these genes showed the production of the recombinant TKS and OAC enzymes, detected via Western blot analysis, and the production of cannabinoids precursor (OA) detected using the HPLC/UV spectrum when compared to the wild-type strain. Quantitative analysis revealed significant olivetolic acid accumulation (0.6-2.6 mg/L), demonstrating the successful integration and functionality of the heterologous genes. Furthermore, the introduction of TKS and OAC genes led to the synthesis of novel molecules, potentially expanding the repertoire of bioactive compounds accessible through diatom-based biotechnology. This study demonstrates the successful bioengineering of P. tricornutum with cannabis genes, enabling the production of OA as a precursor for cannabinoid production and the synthesis of novel molecules with potential pharmaceutical applications.

Using the Standing and Walking Assessment Tool at Discharge Predicts Community Outdoor Walking Capacity in Persons With Traumatic Spinal Cord Injury

OBJECTIVE

The Standing and Walking Assessment Tool (SWAT) standardizes the timing and content of walking assessments during inpatient rehabilitation by combining 12 stages ranging from lowest to highest function (0, 0.5, 1A, 1B, 1C, 2A, 2B, 2C, 3A, 3B, 3C, and 4) with 5 standard measures: the Berg Balance Scale, the modified Timed "Up & Go" test, the Activities-specific Balance Confidence Scale, the modified 6-Minute Walk Test, and the 10-Meter Walk Test (10MWT). This study aimed to determine if the SWAT at rehabilitation discharge could predict outdoor walking capacity 1-year after discharge in people with traumatic spinal cord injury.

METHODS

This retrospective study used data obtained from the Rick Hansen Spinal Cord Injury Registry from 2014 to 2020. Community outdoor walking capacity was measured using the Spinal Cord Independence Measure III (SCIM III) outdoor mobility score obtained 12 (±4) months after discharge. Of 206 study participants, 90 were community nonwalkers (ie, SCIM III score 0-3), 41 were community walkers with aids (ie, SCIM III score 4-6), and 75 were independent community walkers (ie, SCIM III score 7-8). Bivariate, multivariable regression, and an area under the receiver operating characteristic curve analyses were performed.

RESULTS

At rehabilitation discharge, 3 significant SWAT associations were confirmed: 0-3A with community nonwalkers, 3B/higher with community walkers with and without an aid, and 4 with independent community walkers. Moreover, at discharge, a higher (Berg Balance Scale, Activities-specific Balance Confidence Scale), faster (modified Timed "Up & Go," 10MWT), or further (10MWT) SWAT measure was significantly associated with independent community walking. Multivariable analysis indicated that all SWAT measures, except the 10MWT were significant predictors of independent community walking. Furthermore, the Activities-Specific Balance Confidence Scale had the highest area under the receiver operating characteristic score (0.91), demonstrating an excellent ability to distinguish community walkers with aids from independent community walkers.

CONCLUSION

The SWAT stage and measures at discharge can predict community outdoor walking capacity in persons with traumatic spinal cord injury. Notably, a patient's confidence in performing activities plays an important part in achieving walking ability in the community.

IMPACT

The discharge SWAT is useful to optimize discharge planning.

Interrater reliability of the Standing and Walking Assessment Tool for spinal cord injury

STUDY DESIGN

Psychometric study.

OBJECTIVES

The Standing and Walking Assessment Tool (SWAT) is a standardized approach to the evaluation of standing and walking capacity following traumatic spinal cord injury (tSCI) in Canada. The SWAT classifies individuals with a tSCI into 12 stages of standing and walking capacity that are paired with well-established outcome measures, such as the Berg Balance Scale and 10-m Walk Test. Prior research has demonstrated the validity and responsiveness of the SWAT stages; however, the reliability remains unknown. The objective of this study was to evaluate the interrater reliability of the SWAT stages.

SETTING

Inpatient units of two Canadian rehabilitation hospitals.

METHODS

Adults with sub-acute tSCI were recruited. SWAT stage was evaluated for each participant by two physical therapists separately. The two therapists aimed to complete the evaluations within one day of each other. To evaluate interrater reliability, the percentage agreement between the SWAT stages rated by the two physical therapists was calculated, along with a linear weighted kappa statistic with a 95% CI.

RESULTS

Forty-five individuals with sub-acute tSCI (36 males, 9 females, mean (SD) age of 54.8 (17.9) years) participated. The percentage agreement in SWAT stages between the two physical therapists was 75.6%. A kappa statistic of 0.93 with a 95% CI, 0.81-1.05 was obtained. In cases where therapists disagreed (18% of participants), therapists differed by 1-2 stages only.

CONCLUSIONS

The SWAT stages have high interrater reliability, providing further support for the use of the SWAT in rehabilitation practice in Canada.

Wastewater-based epidemiology: the crucial role of viral shedding dynamics in small communities

Background

Wastewater surveillance (WWS) of pathogens is a rapidly evolving field owing to the 2019 coronavirus disease pandemic, which brought about a paradigm shift in public health authorities for the management of pathogen outbreaks. However, the interpretation of WWS in terms of clinical cases remains a challenge, particularly in small communities where large variations in pathogen concentrations are routinely observed without a clear relation to clinical incident cases.

Methods

Results are presented for WWS from six municipalities in the eastern part of Canada during the spring of 2021. We developed a numerical model based on viral kinetics reduction functions to consider both prevalent and incident cases to interpret the WWS data in light of the reported clinical cases in the six surveyed communities.

Results

The use of the proposed numerical model with a viral kinetics reduction function drastically increased the interpretability of the WWS data in terms of the clinical cases reported for the surveyed community. In line with our working hypothesis, the effects of viral kinetics reduction modeling were more important in small communities than in larger communities. In all but one of the community cases (where it had no effect), the use of the proposed numerical model led to a change from a +1.5% (for the larger urban center, Quebec City) to a +48.8% increase in the case of a smaller community (Drummondville).

Conclusion

Consideration of prevalent and incident cases through the proposed numerical model increases the correlation between clinical cases and WWS data. This is particularly the case in small communities. Because the proposed model is based on a biological mechanism, we believe it is an inherent part of any wastewater system and, hence, that it should be used in any WWS analysis where the aim is to relate WWS measurement to clinical cases.

A multi-center international study on the spinal cord independence measure, version IV: Rasch psychometric validation

CONTEXT

The Spinal Cord Independence Measure is a comprehensive functional rating scale for individuals with spinal cord lesion (SCL).

OBJECTIVE

To validate the scores of the three subscales of SCIM IV, the fourth version of SCIM, using advanced statistical methods.

STUDY DESIGN

Multi-center cohort study.

SETTING

Nineteen SCL units in 11 countries.

METHODS

SCIM developers created SCIM IV following comments by experts, included more accurate definitions of scoring criteria in the SCIM IV form, and adjusted it to assess specific conditions or situations that the third version, SCIM III, does not address. Professional staff members assessed 648 SCL inpatients, using SCIM IV and SCIM III, at admission to rehabilitation, and at discharge. The authors examined the validity and reliability of SCIM IV subscale scores using Rasch analysis.

RESULTS

The study included inpatients aged 16-87 years old. SCIM IV subscale scores fit the Rasch model. All item infit and most item outfit mean-square indices were below 1.4; statistically distinct strata of abilities were 2.6-6; most categories were properly ordered; item hierarchy was stable across most clinical subgroups and countries. In a few items, however, we found misfit or category threshold disordering. We found SCIM III and SCIM IV Rasch properties to be comparable.

CONCLUSIONS

Rasch analysis suggests that the scores of each SCIM IV subscale are reliable and valid. This reinforces the justification for using SCIM IV in clinical practice and research.

Right Superior Frontal Gyrus Cortical Thickness in Pediatric ADHD

OBJECTIVE

We investigated the right Superior Frontal Gyrus (right-SFG) and Anterior Cingulate Cortex (ACC) in children with ADHD and their clinical relevance with Executive Function (EF) and ADHD symptom severity.

METHODS

About 26 children with ADHD and 24 typically developing children (TDC; 7‒16 years) underwent Magnetic Resonance Imaging (MRI) and completed an EF assessment battery.

RESULTS

Significantly thinner right-SFG in the ADHD group was found compared to the TDC group (t (48) = 2.81, p = .007, Cohen's d = 0.84). Linear regression models showed that 12.5% of inattention, 13.6% of hyperactivity, and 9.0% of EF variance was accounted for by the right-SFG thickness.

CONCLUSIONS

Differences in the right-SFG thickness were found in our ADHD group and were associated with parent ratings of inattentive and hyperactive symptoms as well with EF ratings. These results replicate previous findings of thinner right-SFG and are consistent with the delayed cortical maturation theory of ADHD.

A genome-wide screen identifies SCAI as a modulator of the UV-induced replicative stress response

Helix-destabilizing DNA lesions induced by environmental mutagens such as UV light cause genomic instability by strongly blocking the progression of DNA replication forks (RFs). At blocked RF, single-stranded DNA (ssDNA) accumulates and is rapidly bound by Replication Protein A (RPA) complexes. Such stretches of RPA-ssDNA constitute platforms for recruitment/activation of critical factors that promote DNA synthesis restart. However, during periods of severe replicative stress, RPA availability may become limiting due to inordinate sequestration of this multifunctional complex on ssDNA, thereby negatively impacting multiple vital RPA-dependent processes. Here, we performed a genome-wide screen to identify factors that restrict the accumulation of RPA-ssDNA during UV-induced replicative stress. While this approach revealed some expected "hits" acting in pathways such as nucleotide excision repair, translesion DNA synthesis, and the intra-S phase checkpoint, it also identified SCAI, whose role in the replicative stress response was previously unappreciated. Upon UV exposure, SCAI knock-down caused elevated accumulation of RPA-ssDNA during S phase, accompanied by reduced cell survival and compromised RF progression. These effects were independent of the previously reported role of SCAI in 53BP1-dependent DNA double-strand break repair. We also found that SCAI is recruited to UV-damaged chromatin and that its depletion promotes nascent DNA degradation at stalled RF. Finally, we (i) provide evidence that EXO1 is the major nuclease underlying ssDNA formation and DNA replication defects in SCAI knockout cells and, consistent with this, (ii) demonstrate that SCAI inhibits EXO1 activity on a ssDNA gap in vitro. Taken together, our data establish SCAI as a novel regulator of the UV-induced replicative stress response in human cells.

Differences in neurometabolites and transcranial magnetic stimulation motor maps in children with attention-deficit/hyperactivity disorder

BACKGROUND

Although much is known about cognitive dysfunction in attention-deficit/hyperactivity disorder (ADHD), few studies have examined the pathophysiology of disordered motor circuitry. We explored differences in neurometabolite levels and transcranial magnetic stimulation (TMS)-derived corticomotor representations among children with ADHD and typically developing children.

METHODS

We used magnetic resonance spectroscopy (MRS) protocols to measure excitatory (glutamate + glutamine [Glx]) and inhibitory (γ-aminobutyric acid [GABA]) neurometabolite levels in the dominant primary motor cortex (M1) and the supplementary motor area (SMA) in children with ADHD and typically developing children. We used robotic neuronavigated TMS to measure corticospinal excitability and create corticomotor maps.

RESULTS

We collected data from 26 medication-free children with ADHD (aged 7-16 years) and 25 typically developing children (11-16 years). Children with ADHD had lower M1 Glx (p = 0.044, d = 0.6); their mean resting motor threshold was lower (p = 0.029, d = 0.8); their map area was smaller (p = 0.044, d = 0.7); and their hotspot density was higher (p = 0.008, d = 0.9). M1 GABA levels were associated with motor map area (p = 0.036).Limitations: Some TMS data were lost because the threshold of some children exceeded 100% of the machine output. The relatively large MRS voxel required to obtain sufficient signal-to-noise ratio and reliably measure GABA levels encompassed tissue beyond the M1, making this measure less anatomically specific.

CONCLUSION

The neurochemistry and neurophysiology of key nodes in the motor network may be altered in children with ADHD, and the differences appear to be related to each other. These findings suggest potentially novel neuropharmacological and neuromodulatory targets for ADHD.

Parental evaluation of a revised autism spectrum disorder diagnostic process for children under 36 months of age

Background

The Alberta Children's Hospital-Autism Spectrum Disorder Diagnostic Clinic (ACH-ASDC) was restructured due to long wait times and unsustainable clinic workflow. Major changes included the initiation of pre- and post-ASD parent education sessions and distinct ASD screening appointments before the ASD diagnostic appointment.

Methods

We conducted a parental program evaluation in summer 2018 of the ACH-ASDC. We used a cross-sectional survey to evaluate key outcomes including parental satisfaction, and the percentage of families obtaining access to government supports and early intervention programs.

Results

For the 101 eligible patients diagnosed with ASD under 36 months of age 70 (69.3%) parents agreed to participate. The mean diagnostic age of the children diagnosed with ASD was 30.6 months (SD=4.1 months). There were no statistically significant age differences between biological sexes. Ninety-three per cent of parents felt that ASD educational sessions were useful, and 92% of parents were satisfied to very satisfied with the overall ASD diagnostic process. Ninety per cent of parents had access to at least one of the key resources available for ASD early intervention in our province following diagnosis. Parents reported a positive impact on intervention provided to their child in the areas of communication, social interaction, and behaviour.

Conclusion

Parents of children diagnosed with ASD expressed a high level of satisfaction with the restructured ACH-ASDC process. Implementing parent education sessions was well received and met parents' needs. Parents were able to access intervention services following diagnosis and reported positive impacts for their child. Re-envisioning program approaches to incorporate novel strategies to support families should be encouraged.

Cross-validation of ELISA and a portable surface plasmon resonance instrument for IgG antibody serology with SARS-CoV-2 positive individuals

We report on the development of surface plasmon resonance (SPR) sensors and matching ELISAs for the detection of nucleocapsid and spike antibodies specific against the novel coronavirus 2019 (SARS-CoV-2) in human serum, plasma and dried blood spots (DBS). When exposed to SARS-CoV-2 or a vaccine against SARS-CoV-2, the immune system responds by expressing antibodies at levels that can be detected and monitored to identify the fraction of the population potentially immunized against SARS-CoV-2 and support efforts to deploy a vaccine strategically. A SPR sensor coated with a peptide monolayer and functionalized with various sources of SARS-CoV-2 recombinant proteins expressed in different cell lines detected human anti-SARS-CoV-2 IgG antibodies in clinical samples. Nucleocapsid expressed in different cell lines did not significantly change the sensitivity of the assays, whereas the use of a CHO cell line to express spike ectodomain led to excellent performance. This bioassay was performed on a portable SPR instrument capable of measuring 4 biological samples within 30 minutes of sample/sensor contact and the chip could be regenerated at least 9 times. Multi-site validation was then performed with in-house and commercial ELISA, which revealed excellent cross-correlations with Pearson's coefficients exceeding 0.85 in all cases, for measurements in DBS and plasma. This strategy paves the way to point-of-care and rapid testing for antibodies in the context of viral infection and vaccine efficacy monitoring.

Impact of COVID-19 on lifestyle habits and mental health symptoms in children with attention-deficit/hyperactivity disorder in Canada

Objectives

The COVID-19 pandemic created an environment of restricted access to health and recreation services. Lifestyle habits including sleep, eating, exercise, and screen use were modified, potentially exacerbating adverse mental health outcomes. This study investigates the impact of COVID-19 on lifestyle habits and mental health symptoms in paediatric attention-deficit/hyperactivity disorder (ADHD) in Canada.

Methods

An online survey was distributed across Canada to caregivers of children with ADHD (children aged 5 to 18 years) assessing depression (PHQ-9), anxiety (GAD-7), ADHD (SNAP-IV), and lifestyle behaviours. Data were analyzed by gender (male/female) and age category (5 to 8, 9 to 12, and 13 to 18 years). Spearman’s correlations between lifestyle habits and mental health outcomes were conducted.

Results

A total of 587 surveys were completed. Mean child age was 10.14 years (SD 3.06), including 166 females (28.3%). The PHQ-9 and GAD-7 indicated that 17.4% and 14.1% of children met criteria for moderately severe to severe depression and anxiety symptoms respectively. Children met SNAP-IV cut-off scores for inattention (73.7%), hyperactivity/impulsivity (66.8%), and oppositional defiant disorder (38.6%) behaviours. Caregivers reported changes in sleep (77.5%), eating (58.9%), exercise (83.7%), and screen use (92.9%) in their ADHD child, greatly impacting youth. Sleeping fewer hours/night, eating more processed foods, and watching TV/playing videogames >3.5 hours/day correlated with greater depression, anxiety and ADHD symptoms, and exercising <1 hour/day further correlated with depression symptoms (P<0.01).

Conclusions

The COVID-19 pandemic has resulted in less healthy lifestyle habits and increased mental health symptoms in Canadian children with ADHD. Longitudinal studies to better understand the relationship between these factors are recommended.

Characterization of standing balance after incomplete spinal cord injury: Alteration in integration of sensory information in ambulatory individuals

BACKGROUND

Up to one-third of individuals with a recent spinal cord injury (SCI) and most of the individuals with an incomplete lesion are able to regain partial balance and walking ability after the first-year post-injury. However, most individuals experience injurious falls while standing and frequent losses of balance post-rehabilitation, which can result in physical injuries and a fear of falling.

RESEARCH QUESTION

Control of balance during quiet standing depends on the integration of sensory information. Since SCI causes sensory and motor impairments, understanding the underlying mechanisms of how postural control is regulated is of significant importance for targeted and guided rehabilitation post-SCI.

METHODS

We characterized the impact of a variety of challenging conditions on the standing balance for eight participants with incomplete SCI with walking ability compared to twelve age-matched able-bodied individuals using a waist-mounted inertial measurement unit (IMU). We compared balance biomarkers derived from IMUs' readouts under conditions that challenged balance by affecting somatosensory (i.e., standing on hard vs. foam surfaces) and visual (i.e., eyes open vs. closed) inputs. We performed a three-way ANOVA or a Kruskal-Wallis test to characterize changes in postural control post-SCI based on reliance on somatosensory and visual information using balance biomarkers.

RESULTS

We observed a reduced stability performance, an increased control demand, and a less effective active correction post-SCI in all standing conditions. Due to impaired somatosensory feedback, individuals with incomplete SCI showed a higher and lower reliance on visual and somatosensory information, respectively, for maintaining balance (p < 0.05).

SIGNIFICANCE

Using a single waist-mounted IMU, the proposed method could characterize standing balance in individuals with incomplete SCI compared to able-bodied participants. Having high clinical utility and sufficient resolution with discriminatory ability, our method could be used in the future to objectively evaluate the effectiveness of rehabilitative interventions on the balance performance of individuals with SCI.

Postural control strategy after incomplete spinal cord injury: effect of sensory inputs on trunk-leg movement coordination

BACKGROUND

Postural control is affected after incomplete spinal cord injury (iSCI) due to sensory and motor impairments. Any alteration in the availability of sensory information can challenge postural stability in this population and may lead to a variety of adaptive movement coordination patterns. Hence, identifying the underlying impairments and changes to movement coordination patterns is necessary for effective rehabilitation post-iSCI. This study aims to compare the postural control strategy between iSCI and able-bodied populations by quantifying the trunk-leg movement coordination under conditions that affects sensory information.

METHODS

13 individuals with iSCI and 14 aged-matched able-bodied individuals performed quiet standing on hard and foam surfaces with eyes open and closed. We used mean Magnitude-Squared Coherence between trunk-leg accelerations measured by accelerometers placed over the sacrum and tibia.

RESULTS

We observed a similar ankle strategy at lower frequencies (f ≤ 1.0 Hz) between populations. However, we observed a decreased ability post-iSCI in adapting inter-segment coordination changing from ankle strategy to ankle-hip strategy at higher frequencies (f > 1.0 Hz). Moreover, utilizing the ankle-hip strategy at higher frequencies was challenged when somatosensory input was distorted, whereas depriving visual information did not affect balance strategy.

CONCLUSION

Trunk-leg movement coordination assessment showed sensitivity, discriminatory ability, and excellent test-retest reliability to identify changes in balance control strategy post-iSCI and due to altered sensory inputs. Trunk-leg movement coordination assessment using wearable sensors can be used for objective outcome evaluation of rehabilitative interventions on postural control post-iSCI.

Magnetic Resonance Spectroscopy of γ-Aminobutyric Acid and Glutamate Concentrations in Children With Attention-Deficit/Hyperactivity Disorder

This cohort study assesses concentrations of γ-aminobutyric acid (GABA) and glutamate in children with attention-deficit/hyperactivity disorder (ADHD) compared with typically developing children.

Effect of cathode material and charge loading on the nitrification performance and bacterial community in leachate treating Electro-MBRs

Electro-MBR technology, which combines an electrocoagulation process inside the mixed liquor of a membrane bioreactor, was studied for the treatment of a high-strength ammonia leachate (124 ± 4 mg NH₄-N L^-1). A lab-scale aerobic Electro-MBR was operated with a solid retention time of 45 days, hydraulic retention times of 24h and 12h, and charge loading ranging from 100 to 400 mAh L^-1. At 400 mAh L^-1, with a combination of a Ti/Pt cathode and a sacrificial iron anode, removal percentages for ammonia nitrogen, total organic carbon, and total phosphorus were 99.8%, 38%, and 99.0%, respectively. At 400 mAh L^-1, the estimated ferric ion dosage was 325 mg Fe³⁺ L^-1. Experiments conducted with different cathode materials showed that previously reported inhibition phenomena may result from a cathodic nitrate reduction into ammonia nitrogen. Conventional cathode materials, such as graphite, have electrochemical nitrate reduction rates of -0.03 mg NO₃-N mAh^-1. By comparison, when using Ti/Pt, the rate was -0.0045 mg NO₃-N mAh^-1(85% lower than graphite due to its low hydrogen overpotential). Charge loading tested in this study had no significant impact on both nitrification performance and microbial population diversity. However, the relative abundance of the mixed liquor's Nitrosomonas increased from 4.8% to 8.2% when the charge loading increased from 0 to 400 mAh L^-1. Results from this study are promising for future applications of the Ti/Pt - Iron Electro-MBR in various high-strength ammonia wastewater treatment applications.

Identifying the link between MBRs' key operating parameters and bacterial community: A step towards optimized leachate treatment

A MBR treating compost leachate was studied in order to link the operating parameters (solid and hydraulic retention time) to contaminant's specific bacterial catabolic activity. In this context, a lab-scale aerobic membrane bioreactor was operated for 200 days, at solid retention times (SRT) of 30 and 45 days and four different contaminant load rates. Results showed that increasing the food to microorganism ratio (F/M) by increasing the contaminant load rates lessened the selectivity pressure, which allowed the proliferation of subdominant operational taxonomic units (OTU) (relative abundance >3%) that were otherwise inhibited by highly adapted dominant OTUs (relative abundance >10%). Subsequently, increasing the SRT resulted in a lower species richness and the selection of two dominant types of bacteria: 1) genera with low growth rates that feed on non-limiting substrates or substrates with few competitors, and 2) genera with metabolisms that are highly specific to the available substrates and that can outcompete the other genera by using the substrate more efficiently. The bacterial population evolution observed during this study suggests that the mixed liquor population diversity and structure can be modulated with the operating conditions for the bioenhancement of contaminant specific catabolic activity. Identified dominant and subdominant genera were linked to the MBR's NH₄⁺ and COD removal performances. Interestingly, nitrification performances were unaffected by the organic load rate and the Nitrosomonas relative abundance.

The standing and walking assessment tool for individuals with spinal cord injury: A qualitative study of validity and clinical use

Context/Objective: The Spinal Cord Injury (SCI) Standing and Walking Assessment Tool (SWAT) combines stages of walking recovery with measures of balance and walking. It standardizes the timing and content of walking assessment in inpatient rehabilitation. The study aims were: (1) Evaluate the content validity of the SWAT stages of walking recovery, and (2) Understand physical therapists' (PTs) experiences using the SWAT to gauge acceptance, implementation and impact. Design: Qualitative, exploratory study. Setting: Nine Canadian rehabilitation hospitals. Participants: Thirty-four PTs who had used the SWAT ≥10 times. Interventions: Seven focus group meetings were completed. Semi-structured questions queried the content, order and spacing of SWAT stages, and current SWAT use (i.e. processes, challenges, facilitators, impact on practice). Meetings were audio-recorded and transcribed. Themes and categories were derived through a conventional content analysis. Outcome Measure: Not applicable. Results: PTs agreed with the ordering and content of the SWAT stages, but reported unequal spacing between stages. Three themes related to PTs' use of the SWAT were identified: (1) Variable process: SWAT implementation varied across sites, PTs and patients. (2) Implementation challenges: unfamiliarity of the SWAT, lack of time, not required by place of work, and patients who are outliers or have poor gait quality. (3) Potential to influence clinical decision-making: the SWAT did not influence clinical decisions, but PTs recognized the potential of the tool to do so. Conclusions: Content validity of the SWAT stages was supported and implementation challenges identified. Variability in SWAT implementation may reflect the heterogeneity and person-centeredness of SCI rehabilitation.

Long noncoding RNA repertoire and targeting by nuclear exosome, cytoplasmic exonuclease, and RNAi in fission yeast

Long noncoding RNAs (lncRNAs), which are longer than 200 nucleotides but often unstable, contribute a substantial and diverse portion to pervasive noncoding transcriptomes. Most lncRNAs are poorly annotated and understood, although several play important roles in gene regulation and diseases. Here we systematically uncover and analyze lncRNAs in Schizosaccharomyces pombe. Based on RNA-seq data from twelve RNA-processing mutants and nine physiological conditions, we identify 5775 novel lncRNAs, nearly 4× the previously annotated lncRNAs. The expression of most lncRNAs becomes strongly induced under the genetic and physiological perturbations, most notably during late meiosis. Most lncRNAs are cryptic and suppressed by three RNA-processing pathways: the nuclear exosome, cytoplasmic exonuclease, and RNAi. Double-mutant analyses reveal substantial coordination and redundancy among these pathways. We classify lncRNAs by their dominant pathway into cryptic unstable transcripts (CUTs), Xrn1-sensitive unstable transcripts (XUTs), and Dicer-sensitive unstable transcripts (DUTs). XUTs and DUTs are enriched for antisense lncRNAs, while CUTs are often bidirectional and actively translated. The cytoplasmic exonuclease, along with RNAi, dampens the expression of thousands of lncRNAs and mRNAs that become induced during meiosis. Antisense lncRNA expression mostly negatively correlates with sense mRNA expression in the physiological, but not the genetic conditions. Intergenic and bidirectional lncRNAs emerge from nucleosome-depleted regions, upstream of positioned nucleosomes. Our results highlight both similarities and differences to lncRNA regulation in budding yeast. This broad survey of the lncRNA repertoire and characteristics in S. pombe, and the interwoven regulatory pathways that target lncRNAs, provides a rich framework for their further functional analyses.

Redesign of the autism spectrum screening and diagnostic process for children aged 12 to 36 months

Diagnosing autism spectrum disorder (ASD) is challenging, resource-intense and time-consuming due to clinical and etiologic heterogeneity. With the rapid increase in prevalence of ASD, higher demand for diagnostic assessment often means long waitlists for families, and limited access to specialized intervention and support. In 2013, the Alberta Children's Hospital-Autism Spectrum Disorder Diagnostic Clinic (ACH-ASDC) experienced a significant waitlist in the 12 to 36 months' population. A Quality Improvement Project was started in 2014; one program aim was to create an efficient, sustainable and evidence-based ASD diagnostic evaluation process. The redesigned diagnostic process included: 1) pre- and postassessment parent information sessions, 2) a screening appointment and 3) standardized clinical appointment pathways. Within its first year, the new process reduced wait times to under a month without an increase in resources, leading to an efficient diagnostic process being sustained since its implementation.

Comparative analysis of alternative polyadenylation in S. cerevisiae and S. pombe

Alternative polyadenylation (APA) is a widespread mechanism that generates mRNA isoforms with distinct properties. Here we have systematically mapped and compared cleavage and polyadenylation sites (PASs) in two yeast species, S. cerevisiae and S. pombe. Although >80% of the mRNA genes in each species were found to display APA, S. pombe showed greater 3′ UTR size differences among APA isoforms than did S. cerevisiae. PASs in different locations of gene are surrounded with distinct sequences in both species and are often associated with motifs involved in the Nrd1-Nab3-Sen1 termination pathway. In S. pombe, strong motifs surrounding distal PASs lead to higher abundances of long 3′ UTR isoforms than short ones, a feature that is opposite in S. cerevisiae. Differences in PAS placement between convergent genes lead to starkly different antisense transcript landscapes between budding and fission yeasts. In both species, short 3′ UTR isoforms are more likely to be expressed when cells are growing in nutrient-rich media, although different gene groups are affected in each species. Significantly, 3′ UTR shortening in S. pombe coordinates with up-regulation of expression for genes involved in translation during cell proliferation. Using S. pombe strains deficient for Pcf11 or Pab2, we show that reduced expression of 3′-end processing factors lengthens 3′ UTR, with Pcf11 having a more potent effect than Pab2. Taken together, our data indicate that APA mechanisms in S. pombe and S. cerevisiae are largely different: S. pombe has many of the APA features of higher species, and Pab2 in S. pombe has a different role in APA regulation than its mammalian homolog, PABPN1.

Evolutions in clinical reasoning assessment: The Evolving Script Concordance Test

INTRODUCTION

Script concordance testing (SCT) is a method of assessment of clinical reasoning. We developed a new type of SCT case design, the evolving SCT (E-SCT), whereby the patient's clinical story is "evolving" and with thoughtful integration of new information at each stage, decisions related to clinical decision-making become increasingly clear.

OBJECTIVES

We aimed to: (1) determine whether an E-SCT could differentiate clinical reasoning ability among junior residents (JR), senior residents (SR), and pediatricians, (2) evaluate the reliability of an E-SCT, and (3) obtain qualitative feedback from participants to help inform the potential acceptability of the E-SCT.

METHODS

A 12-case E-SCT, embedded within a 24-case pediatric SCT (PaedSCT), was administered to 91 pediatric residents (JR: n = 50; SR: n = 41). A total of 21 pediatricians served on the panel of experts (POE). A one-way analysis of variance (ANOVA) was conducted across the levels of experience. Participants' feedback on the E-SCT was obtained with a post-test survey and analyzed using two methods: percentage preference and thematic analysis.

RESULTS

Statistical differences existed across levels of training: F = 19.31 (df = 2); p < 0.001. The POE scored higher than SR (mean difference = 10.34; p < 0.001) and JR (mean difference = 16.00; p < 0.001). SR scored higher than JR (mean difference = 5.66; p < 0.001). Reliability (Cronbach's α) was 0.83. Participants found the E-SCT engaging, easy to follow and true to the daily clinical decision-making process.

CONCLUSIONS

The E-SCT demonstrated very good reliability and was effective in distinguishing clinical reasoning ability across three levels of experience. Participants found the E-SCT engaging and representative of real-life clinical reasoning and decision-making processes. We suggest that further refinement and utilization of the evolving style case will enhance SCT as a robust, engaging, and relevant method for the assessment of clinical reasoning.

The Nrd1-like protein Seb1 coordinates cotranscriptional 3' end processing and polyadenylation site selection

Termination of RNA polymerase II (RNAPII) transcription is associated with RNA 3' end formation. For coding genes, termination is initiated by the cleavage/polyadenylation machinery. In contrast, a majority of noncoding transcription events in Saccharomyces cerevisiae does not rely on RNA cleavage for termination but instead terminates via a pathway that requires the Nrd1-Nab3-Sen1 (NNS) complex. Here we show that the Schizosaccharomyces pombe ortholog of Nrd1, Seb1, does not function in NNS-like termination but promotes polyadenylation site selection of coding and noncoding genes. We found that Seb1 associates with 3' end processing factors, is enriched at the 3' end of genes, and binds RNA motifs downstream from cleavage sites. Importantly, a deficiency in Seb1 resulted in widespread changes in 3' untranslated region (UTR) length as a consequence of increased alternative polyadenylation. Given that Seb1 levels affected the recruitment of conserved 3' end processing factors, our findings indicate that the conserved RNA-binding protein Seb1 cotranscriptionally controls alternative polyadenylation.

Contribution of SWEET to improve paediatric diabetes care in developing countries

Diabetes affects many children living in developing countries. Through an informal survey, five SWEET (Better control in Pediatric and Adolescent diabeteS: Working to crEate CEnTers of Reference) centers from developing countries (Mali, Costa Rica, Argentina and two from India) share their perspective on caring for children with diabetes. Each center provides a description of the population of children with diabetes they serve, the organization of care, and the challenges encountered on a daily basis in the provision of this care. In the second part, we summarize the anticipated benefits and challenges associated with participation in SWEET. This resulting article is a testimony of the reality of managing diabetes by dynamic teams striving to achieve recommended standards of care for pediatric diabetes in an environment with limited resources.

Fail-safe transcription termination: Because one is never enough

Termination of RNA polymerase II (RNAPII) transcription is a fundamental step of gene expression that involves the release of the nascent transcript and dissociation of RNAPII from the DNA template. As transcription termination is intimately linked to RNA 3' end processing, termination pathways have a key decisive influence on the fate of the transcribed RNA. Quite remarkably, when reaching the 3' end of genes, a substantial fraction of RNAPII fail to terminate transcription, requiring the contribution of alternative or "fail-safe" mechanisms of termination to release the polymerase. This point of view covers redundant mechanisms of transcription termination and how they relate to conventional termination models. In particular, we expand on recent findings that propose a reverse torpedo model of termination, in which the 3'5' exonucleolytic activity of the RNA exosome targets transcription events associated with paused and backtracked RNAPII.

Improving Diagnostic Efficiency in Children Aged 12-39 Months Referred for Autism Spectrum Disorder (ASD)

BACKGROUND: Early diagnosis and intervention for ASD is important. The increasing prevalence of ASD in Canada is challenging teams performing ASD diagnostic evaluations to keep pace with demand. In October 2013, the ASD clinic at our Pediatric Tertiary Care Centre (PTCC) faced a waitlist of more than twelve months for children under 39 months of age; it became necessary to engage in a quality improvement with the aim of looking for efficiencies with a focus of reducing our waitlist.

OBJECTIVES: To present a) two years of experience (Jan. 2014-Dec. 2015) using our diagnostic assessment model for evaluation of children aged 12-39 months referred for ASD evaluation to PTCC, and b) psychometric performance of RITA-T (Rapid Interactive Test for Autism in Toddlers-developed by Choueiri/Wagner – Boston).

DESIGN/METHODS: This quality improvement project incorporated evidence-based practice with process improvement methodology. Our team utilized a Plan-Do-Study-Act (PDSA) approach in the development of a ‘new’ ASD standardized diagnostic process. Our new model included: a) an initial mandatory parent education session followed one week later by b) a child visit using the face-to-face ‘level 2 screening tool’ (RITA-T) + completion of M-CHAT (questionnaire) followed in 7-10 days by c) an ASD diagnostic evaluation appointment, and finally 5-7 days after evaluation d) an “After ASD Diagnosis” parent group session.

RESULTS: We assessed a total of 173 patients (81% male, mean age 30.74±5.53 mo., interval 15.4-39.0 mo.). The diagnostic process was completed within a max 30-day cycle (previously a period &gt;4 months) and required less hours/child (12 vs. 20 hours – overall 40% net gain or 1384 hours). Waitlist was reduced to &lt;1 month (compared to &gt;12 mo. in Oct. 2013). A total of 143 children (82.7% of total cohort; 116 male/27 female) were diagnosed with ASD. The discriminative properties of RITA-T were calculated: Sensitivity: 0.99; Specificity 0.53; Positive Predictive Value 0.91; Negative Predictive Value: 0.94.

CONCLUSION: By following a combination of quality improvement methodology with evidence-based practice, we successfully reduced wait and cycle times at our PTCC for children aged 12-39 months referred for ASD diagnostic assessment. RITA-T showed very good discriminative properties and was instrumental in the overall process improvement. This sustainable diagnostic approach promoted practice innovation. Consequently, patients are now able to access critical community supports and resources in a timely manner.

Parental Satisfaction Towards Autism Spectrum Disorder Diagnostic Assessment Process for Children 12-39 Months

BACKGROUND: To address lengthy delays in accessing diagnostic assessment for Autism Spectrum Disorder (ASD), our ASD services underwent a review of the service model in 2013-2014. In addition to establishing a formal ASD Diagnostic Clinic, the diagnostic evaluation process for children 12-39 months was re-designed. A major implemented change as part of our diagnostic process was the Pre- and Post-diagnosis parent information sessions.

OBJECTIVES: To assess the satisfaction level for parents of children being evaluated through our new ASD diagnostic process for children 12-39 months.

DESIGN/METHODS: This evaluation was done through two different surveys: 1) a validated, standardized telephone survey (average 15 minutes) was administered by an experienced nurse to parents whose child was diagnosed with ASD (January 2014-June 2015) based on the new ASD diagnostic process. Parents were asked to retrospectively evaluate their experience undergoing the new diagnostic assessment process; 2) a subgroup of parents completed a written survey to evaluate the Pre- and Post-diagnosis parent information sessions (of note: survey was given at the end of these educational sessions).

RESULTS: 1) Telephone questionnaire: a total of 68/96 parents were surveyed (71% overall response rate; &gt;90% mothers). Percentage of strongly agree/agree answers were obtained to these statements: a) better awareness of your child’s needs: 78%; b) receiving useful ASD information and educational materials: 90% c) overall process met needs: 77%; d) overall experience: 80%; e) parents having early intervention support since the ASD diagnostic assessment given to their child: 91%; 2) In regards to the educational sessions (Pre-diagnosis ([n=44] & Post ASD Diagnosis [n=33]), the responses to questions on the delivery, content and materials presented revealed &gt;90% level of satisfaction. Challenges to attending theses educational sessions were less than we anticipated.

CONCLUSION: The level of satisfaction to our ‘new’ ASD diagnostic process for children 12-39 months, as reported by parents, was very good. Parents felt the Pre- & Post-educational sessions were positive and valuable. This Quality Improvement initiative, redesigning the ASD diagnostic assessment process, has been validated by families.

Do Children with Adhd Show Improvements in Memory and Behaviour When Stimulant Medication Dosage is Titrated?

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that often negatively impacts behaviour, memory, cognition, and academic achievement. Children with ADHD also exhibit deficits in executive functioning (EF). Currently, stimulant medications are the most commonly used treatment for ADHD; however, finding an ideal dose remains a challenge in the day-to-day practice of pediatricians. Medication titration is a possible option that might help in treatment.

OBJECTIVES: 1) to determine if children with ADHD show improvements in both memory and behaviour when long active methylphenidate (MPH) medication dosage is titrated; 2) to report if differences exist in memory/behaviour results relative to baseline and placebo conditions.

DESIGN/METHODS: A randomized controlled MPH medication trial was conducted with children ages 8-12 with a diagnosis of ADHD. Participants began with 1-week of baseline assessment, followed by a randomized 3-week trial order of placebo, low MPH dose, and high MPH dose. The Wisconsin Selective Reminding Test (WSRT) was used to measure long-term memory storage, retrieval, and learning (memory component) and the Behavior Rating Inventory of Executive Function (BRIEF) was used to measure parental perceptions of EF (behavioural component). These neuropsychological and behavioural assessment results were then graphically depicted and an optimal “best dose” determined for each child that was most effective in improving memory and behaviour. Also, a repeated-measures ANOVA was run to compare between baseline, placebo, and best dose conditions.

RESULTS: A total of 19 children (10 males, 9 females) ages 8-12 (M = 10 years±1.3 years) were enrolled. Statistically significant improvements were noticed on the WSRT (F range = 22.30–48.17, p&lt;.001), and on the BRIEF (F=22.68, p&lt;.001) during the “best dose” condition relative to baseline and placebo. These improvements were similar across most measures for both males and females. In addition, no significant differences were noted between the baseline and placebo conditions for any measure on both the WSRT and BRIEF (F range 0 – 4.11, p range .061 – .994).

CONCLUSION: When neuropsychological and behavioural test results are used to titrate medication and help with “best dose” selection, MPH appears to improve both memory and behaviour in children with ADHD. Overall, no differences were observed between baseline and placebo. Thus, a better understanding of memory and behavioural dose-response relationships may ultimately lead to targeted intervention plans that help foster long-term treatment efficacy in these ADHD children.

Widespread exon skipping triggers degradation by nuclear RNA surveillance in fission yeast

Exon skipping is considered a principal mechanism by which eukaryotic cells expand their transcriptome and proteome repertoires, creating different splice variants with distinct cellular functions. Here we analyze RNA-seq data from 116 transcriptomes in fission yeast (Schizosaccharomyces pombe), covering multiple physiological conditions as well as transcriptional and RNA processing mutants. We applied brute-force algorithms to detect all possible exon-skipping events, which were widespread but rare compared to normal splicing events. Exon-skipping events increased in cells deficient for the nuclear exosome or the 5′-3′ exonuclease Dhp1, and also at late stages of meiotic differentiation when nuclear-exosome transcripts decreased. The pervasive exon-skipping transcripts were stochastic, did not increase in specific physiological conditions, and were mostly present at less than one copy per cell, even in the absence of nuclear RNA surveillance and during late meiosis. These exon-skipping transcripts are therefore unlikely to be functional and may reflect splicing errors that are actively removed by nuclear RNA surveillance. The average splicing rate by exon skipping was ∼0.24% in wild type and ∼1.75% in nuclear exonuclease mutants. We also detected approximately 250 circular RNAs derived from single or multiple exons. These circular RNAs were rare and stochastic, although a few became stabilized during quiescence and in splicing mutants. Using an exhaustive search algorithm, we also uncovered thousands of previously unknown splice sites, indicating pervasive splicing; yet most of these splicing variants were cryptic and increased in nuclear degradation mutants. This study highlights widespread but low frequency alternative or aberrant splicing events that are targeted by nuclear RNA surveillance.

Reconsidering "inattention" in attention-deficit hyperactivity disorder: implications for neuropsychological assessment and intervention

Attention-deficit hyperactivity disorder (ADHD) does not exist. This explicit statement needs elucidation of course given ADHD is a common neurodevelopmental disorder, but it provides the reader with the impetus to reconsider long-held beliefs about this condition and its treatment. Surely, there is a disorder called ADHD from which this thesis is framed, but primary attention and hyperactivity-impulsivity problems are mediated by different albeit interrelated brain systems. Like many neurodevelopmental disorders (e.g., learning disabilities, autism spectrum disorder), the medical and psychological professions have used a single, large inclusive ADHD diagnostic category to represent children with different etiologies for their overt symptoms. Despite neurobiological differences among children diagnosed with ADHD, the clinical position that attention-deficit or primary attention problems are sufficient for ADHD identification undermines clinical practice. This commonly accepted dubious position not only undermines the diagnostic utility of our neuropsychological measures, but it attenuates treatment effects as well. Supported with evidence from our ongoing ADHD research program, this data-based review will support these contentions and provide implications for diagnosis and treatment of children with attention problems.

A motor reeducation program aimed to improve strength and coordination of the upper limb of a hemiparetic subject

The objective of the study is to describe a new reeducation program based on a multi-directional and multi-articular dynamometer and to evaluate its applicability in one chronic right hemiparetic subject. The treatment sessions lasted 1 h and were conducted three times per week for a period of 8 weeks. During these sessions, the subject was asked to exert 10 repetitions of 16 torque combinations exerted at the shoulder, elbow and forearm or combined with handgrip exertion. The sequence of torques and force progressed from proximal to distal joints, and were realized in and out of the typical 'synergy patterns' described in this population. In addition, the levels of torque and force requested were increased progressively throughout the treatment period. The coordination of both upper extremities, tested using the finger to nose test, and the dexterity of the affected side, evaluated using the Box and Blocks assessment, tended to improve as treatments progressed. These results indicate the feasibility of this approach and suggest that it may be worthwhile examining the effectiveness of this approach on improving the functional performance of the upper extremity in a larger population of hemiparetic subjects.

Center-of-pressure total trajectory length is a complementary measure to maximum excursion to better differentiate multidirectional standing limits of stability between individuals with incomplete spinal cord injury and able-bodied individuals

Background

Sensorimotor impairments secondary to a spinal cord injury affect standing postural balance. While quasi-static postural balance impairments have been documented, little information is known about dynamic postural balance in this population. The aim of this study was to quantify and characterize dynamic postural balance while standing among individuals with a spinal cord injury using the comfortable multidirectional limits of stability test and to explore its association with the quasi-static standing postural balance test.

Methods

Sixteen individuals with an incomplete spinal cord injury and sixteen able-bodied individuals participated in this study. For the comfortable multidirectional limits of stability test, participants were instructed to lean as far as possible in 8 directions, separated by 45° while standing with each foot on a forceplate and real-time COP visual feedback provided. Measures computed using the center of pressure (COP), such as the absolute maximal distance reached (COP_max) and the total length travelled by the COP to reach the maximal distance (COP_length), were used to characterize performance in each direction. Quasi-static standing postural balance with eyes open was evaluated using time-domain measures of the COP. The difference between the groups and the association between the dynamic and quasi-static test were analyzed.

Results

The COP_length of individuals with SCI was significantly greater (p ≤ 0.001) than that of able-bodied individuals in all tested directions except in the anterior and posterior directions (p ≤ 0.039), indicating an increased COP trajectory while progressing towards their maximal distance. The COP_max in the anterior direction was significantly smaller for individuals with SCI. Little association was found between the comfortable multidirectional limits of stability test and the quasi-static postural balance test (r ≥ −0.658).

Conclusion

Standing dynamic postural balance performance in individuals with an incomplete spinal cord injury can be differentiated from that of able-bodied individuals with the comfortable limits of stability test. Performance among individuals with an incomplete spinal cord injury is characterized by lack of precision when reaching. The comfortable limits of stability test provides supplementary information and could serve as an adjunct to the quasi-static test when evaluating postural balance in an incomplete spinal cord injury population.

Potential of the smart balance master system to assess standing balance in people with incomplete spinal cord injury

OBJECTIVES

The aim of this study was to investigate the concurrent validity of the Smart Balance Master (SBM) tests in individuals with incomplete spinal cord injury.

DESIGN

Correlational study.

SUBJECTS

A total of 32 individuals with an American Spinal Injury Association Impairment Scale D spinal cord injury able to walk 10 m independently, with or without walking assistive devices.

METHODS

Outcome measures obtained from static and dynamic balance tests while standing using the SBM were compared to data obtained from the Berg Balance Scale (BBS) (14 items).

RESULTS

No difference in performance between paraplegic and tetraplegic subjects was noted in the SBM tests. No ceiling effect was apparent in the SBM tests. The highest levels of association with the BBS was found for the limits of stability test (-0.416 < R < -0.752, p ≤ 0.05). The limits of stability test also correlated significantly with the majority of the other SBM tests and, except for the weight-shifting test, was completed by all but two participants.

CONCLUSION

The limits of stability test of the SBM system appears to be useful for assessing dynamic standing-balance ability in spinal cord injury subjects and could potentially be used to complement the BBS.

Influence of visual inputs on quasi-static standing postural steadiness in individuals with spinal cord injury

Postural steadiness while standing is impaired in individuals with spinal cord injury (SCI) and could be potentially associated with increased reliance on visual inputs. The purpose of this study was to compare individuals with SCI and able-bodied participants on their use of visual inputs to maintain standing postural steadiness. Another aim was to quantify the association between visual contribution to achieve postural steadiness and a clinical balance scale. Individuals with SCI (n = 15) and able-bodied controls (n = 14) performed quasi-static stance, with eyes open or closed, on force plates for two 45 s trials. Measurements of the centre of pressure (COP) included the mean value of the root mean square (RMS), mean COP velocity (MV) and COP sway area (SA). Individuals with SCI were also evaluated with the Mini-Balance Evaluation Systems Test (Mini BESTest), a clinical outcome measure of postural steadiness. Individuals with SCI were significantly less stable than able-bodied controls in both conditions. The Romberg ratios (eyes open/eyes closed) for COP MV and SA were significantly higher for individuals with SCI, indicating a higher contribution of visual inputs for postural steadiness in that population. Romberg ratios for RMS and SA were significantly associated with the Mini-BESTest. This study highlights the contribution of visual inputs in individuals with SCI when maintaining quasi-static standing posture.

Fluorescence monitoring of riboswitch transcription regulation using a dual molecular beacon assay

Riboswitches are mRNA elements that specifically bind cellular metabolites and control gene expression by modifying their structure. As riboswitches often control essential genes in pathogenic bacteria, riboswitches have been proposed as new targets for antibiotics. High-throughput screening provides a powerful approach to identify riboswitch ligand analogs that could act as powerful antibacterial drugs. Biochemical assays have already been used to find riboswitch-binding analogs, but those methods do take into account the transcriptional context for riboswitch regulation. As the importance of co-transcriptional ligand binding has been shown for several riboswitches, it is vital to develop an assay that screens riboswitch-binding analogs during the transcriptional process. Here, we describe the development of a dual molecular beacon system monitoring the transcriptional regulation activity of the Bacillus subtilis pbuE adenine riboswitch. This system relies on two molecular beacons that enable the monitoring of transcription efficiency, as well as the regulatory activity of the riboswitch. Different analogs were tested using our system, and a good correlation was observed between riboswitch activity and reported metabolite affinities. This method is specific, reliable and could be applied at the high-throughput level for the identification of new potential antibiotics targeting any riboswitch-regulating gene expression at the mRNA level.

Complementary and alternative medicine use in children and adolescents with type 1 diabetes

BACKGROUND

The use of complementary and alternative medicine (CAM) in paediatric patients varies between 11% and 68%. There are limited reports of its use in children with type 1 diabetes mellitus (T1DM).

OBJECTIVE

To describe the use of CAM in children with T1DM, and the perceptions of both users and nonusers regarding the effect of CAM on diabetes management.

DESIGN/METHODS

A cross-sectional, anonymous questionnaire survey was mailed to a randomly selected subgroup of patients with T1DM. Each patient's main caregiver was asked to complete the questionnaire.

RESULTS

Of 403 questionnaires mailed, 195 (48%) were completed. The mean (± SD) age of the children was 12.2±4.0 years (56% boys). Use of CAM was reported in 110 children (56%) (vitamins/minerals [n=99], herbal medicine [n=22], dietary supplement [n=13]). When excluding the use of vitamins/minerals, the CAM number dropped to 47 children (24%). Only the current age of the child was significantly different between users and nonusers of CAM. In users, reasons cited for using CAM were to minimize symptoms, improve control, prevent complications and add benefits to insulin. Only 30% of CAM users stated that CAM improved diabetes control. Nonusers cited satisfaction with current diabetes treatment and lack of knowledge as reasons for not using CAM.

CONCLUSIONS

CAM use in children with T1DM was frequent, and appeared to be an attempt to improve control or prevent diabetes complications. However, improved control was not reported as a benefit. Diabetes care teams should assess the use of CAM in children with T1DM, and monitor for any potential positive or negative effects.

The THO complex cooperates with the nuclear RNA surveillance machinery to control small nucleolar RNA expression

THO is a multi-protein complex that promotes coupling between transcription and mRNA processing. In contrast to its role in mRNA biogenesis, we show here that the fission yeast THO complex negatively controls the expression of non-coding small nucleolar (sno) RNAs. Accordingly, the deletion of genes encoding subunits of the evolutionarily conserved THO complex results in increased levels of mature snoRNAs. We also show physical and functional connections between THO and components of the TRAMP polyadenylation complex, whose loss of function also results in snoRNA accumulation. Consistent with a role in snoRNA expression, we demonstrate that THO and TRAMP complexes are recruited to snoRNA genes, and that a functional THO complex is required to maintain TRAMP occupancy at sites of snoRNA transcription. Our findings suggest that THO promotes exosome-mediated degradation of snoRNA precursors by ensuring the presence of the TRAMP complex at snoRNA genes. This study unveils an unexpected role for THO in the control of snoRNA expression and provides a new link between transcription and nuclear RNA decay.

Constitutive regulatory activity of an evolutionarily excluded riboswitch variant

The exquisite specificity of the adenine-responsive riboswitch toward its cognate metabolite has been shown to arise from the formation of a Watson-Crick interaction between the adenine ligand and residue U65. A recent crystal structure of a U65C adenine aptamer variant has provided a rationale for the phylogenetic conservation observed at position 39 for purine aptamers. The G39-C65 variant adopts a compact ligand-free structure in which G39 is accommodated by the ligand binding site and is base-paired to the cytosine at position 65. Here, we demonstrate using a combination of biochemical and biophysical techniques that the G39-C65 base pair not only severely impairs ligand binding but also disrupts the functioning of the riboswitch in vivo by constitutively activating gene expression. Folding studies using single-molecule FRET revealed that the G39-C65 variant displays a low level of dynamic heterogeneity, a feature reminiscent of ligand-bound wild-type complexes. A restricted conformational freedom together with an ability to significantly fold in monovalent ions are exclusive to the G39-C65 variant. This work provides a mechanistic framework to rationalize the evolutionary exclusion of certain nucleotide combinations in favor of sequences that preserve ligand binding and gene regulation functionalities.

Comparative study between transcriptionally- and translationally-acting adenine riboswitches reveals key differences in riboswitch regulatory mechanisms

Many bacterial mRNAs are regulated at the transcriptional or translational level by ligand-binding elements called riboswitches. Although they both bind adenine, the adenine riboswitches of Bacillus subtilis and Vibrio vulnificus differ by controlling transcription and translation, respectively. Here, we demonstrate that, beyond the obvious difference in transcriptional and translational modulation, both adenine riboswitches exhibit different ligand binding properties and appear to operate under different regulation regimes (kinetic versus thermodynamic). While the B. subtilis pbuE riboswitch fully depends on co-transcriptional binding of adenine to function, the V. vulnificus add riboswitch can bind to adenine after transcription is completed and still perform translation regulation. Further investigation demonstrates that the rate of transcription is critical for the B. subtilis pbuE riboswitch to perform efficiently, which is in agreement with a co-transcriptional regulation. Our results suggest that the nature of gene regulation control, that is transcription or translation, may have a high importance in riboswitch regulatory mechanisms.

Bacterial genetic regulation is mostly performed at the levels of transcription and translation. Recently discovered riboswitches are RNA molecules located in untranslated regions of messenger RNAs that modulate the expression of genes involved in the transport and metabolism of small metabolites. Several riboswitches have recently been shown to employ various regulation mechanisms, but no general rules have yet been deduced from these studies. Here, we have analyzed two adenine-sensing riboswitches of Bacillus subtilis and Vibrio vulnificus that differ by the level at which they control gene expression, which is transcription and translation, respectively. We find that, beyond the obvious difference in transcriptional and translational modulation, riboswitch regulation mechanisms of both adenine riboswitches are fundamentally different. For instance, while the adenine riboswitch from B. subtilis performs co-transcriptional binding for gene regulation, the riboswitch from V. vulnificus relies on reversible ligand binding to achieve gene regulation during mRNA translation. In agreement with co-transcriptional binding of the B. subtilis riboswitch, we find that transcriptional pausing is crucial for gene regulation. Our results suggest that the nature of gene regulation control, that is transcription or translation, may have a high importance in riboswitch regulatory mechanisms.

Crossing the borders: poly(A)-binding proteins working on both sides of the fence

The addition of a 3' poly(A) tail is a pre-requisite for the maturation of the majority of eukaryotic transcripts. In most eukaryotic species, RNA poly(A) tails are bound by two important poly(A)-binding proteins (PABPs): PABPC1 and PABPN1 that localize to the cytoplasm and the nucleus, respectively. Such steady state localization for PABPN1 and PABPC1 led to a model whereby PABPN1-bound nuclear mRNAs are remodeled during or after nuclear export so that PABPN1 is replaced by PABPC1 to allow robust cap-dependent translation in the cytoplasm. Here we discuss evidence that challenge the view in which PABPN1 and PABPC1 function solely in the nucleus and cytoplasm, respectively. We discuss accumulating evidence that support nuclear roles for PABPC1 in mRNA biogenesis as well as cytoplasmic roles for PABPN1 in translational control. Because 3' poly(A) tails can also act as a degradation mark via the exosome complex of 3'-5' exonucleases, we also discuss recent results that involve the nuclear PABP in posttranscriptional gene regulation.

The nuclear poly(A)-binding protein interacts with the exosome to promote synthesis of noncoding small nucleolar RNAs

Poly(A)-binding proteins (PABPs) are important to eukaryotic gene expression. In the nucleus, the PABP PABPN1 is thought to function in polyadenylation of pre-mRNAs. Deletion of fission yeast pab2, the homolog of mammalian PABPN1, results in transcripts with markedly longer poly(A) tails, but the nature of the hyperadenylated transcripts and the mechanism that leads to RNA hyperadenylation remain unclear. Here we report that Pab2 functions in the synthesis of noncoding RNAs, contrary to the notion that PABPs function exclusively on protein-coding mRNAs. Accordingly, the absence of Pab2 leads to the accumulation of polyadenylated small nucleolar RNAs (snoRNAs). Our findings suggest that Pab2 promotes poly(A) tail trimming from pre-snoRNAs by recruiting the nuclear exosome. This work unveils a function for the nuclear PABP in snoRNA synthesis and provides insights into exosome recruitment to polyadenylated RNAs.