Autonomic nervous system and endocrine system response to upper or lower cervical spine mobilization in males with persistent post-concussion symptoms: a proof-of-concept trial

INTRODUCTION

The peripheral stress response, consisting of the autonomic nervous system (ANS) and hypothalamic pituitary adrenal-axis (HPA-axis), functions to maintain homeostasis in response to stressors. Cervical spine manual therapy has been shown to differentially modulate the stress response in healthy populations. No study has investigated whether cervical spine mobilizations can differentially modulate the stress response in individuals with persistent post-concussion symptoms (PPCS), a population characterized by a dysfunctional stress response.

METHODS

A randomized, controlled, parallel design trial was performed to investigate whether upper or lower cervical spine mobilization can differentially modulate components of the stress response in individuals with PPCS. The outcomes were salivary cortisol (sCOR) concentration (primary) and the HRV metric, rMSSD, measured with a smartphone application (secondary). Nineteen males diagnosed with PPCS, aged 19-35, were included. Participants were randomly assigned into either intervention group, upper (n = 10) or lower (n = 9) cervical spine mobilization. Each outcome was collected at different time points, pre- and post-intervention. Statistical analyses were performed using the Friedman's Two-Way ANOVA, Mann-Whitney U test, and Wilcoxon Signed Rank Test.

RESULTS

There was a statistically significant within-group reduction in sCOR concentration 30 minutes following lower cervical spine mobilizations and statistically significant within-group increase in rMSSD 30 minutes following upper cervical spine mobilizations.

CONCLUSION

The results of this trial provide preliminary evidence for cervical spine mobilizations to differentially modulate components of the stress response at specific time points. Understanding the mechanisms of the effect of cervical spine mobilizations on the stress response provides a novel rationale for selecting cervical spine mobilizations to rehabilitate individuals with PPCS.

Creating and administering video vignettes for a study examining the communication of diagnostic uncertainty: methodological insights to improve accessibility for researchers and participants

BACKGROUND

Studying clinician-patient communication can be challenging, particularly when research seeks to explore cause-and-effect relationships. Video vignettes - hypothetical yet realistic scenarios - offer advantages to traditional observational approaches by enabling standardisation and manipulation of a clinician-patient encounter for assessment by participants. While published guidelines outline stages to create valid video vignette studies, constructing high quality vignettes which are accessible to a wide range of participants and feasible to produce within time and budget restraints remains challenging. Here, we outline our methods in creating valid video vignettes to study the communication of diagnostic uncertainty. We aim to provide practically useful recommendations for future researchers, and to prompt further reflection on accessibility issues in video vignette methodology.

METHODS

We produced four video vignettes for use in an online study examining the communication of diagnostic uncertainty. We followed established guidelines for vignette production, with specific consideration of how these might be applied pragmatically to save time and resources. Scripts were pilot-tested with 15 laypeople, and videos with 14 laypeople; pilot-testing involved both quantitative and qualitative analysis.

RESULTS AND DISCUSSION

We demonstrate the usefulness of existing guidelines, while also determining that vignette production need not necessarily be expensive or time-consuming to be valid. Our vignettes were filmed using an iPhone camera, and featured a physician rather than a professional actor; nonetheless, pilot-testing found them to be internally and externally valid for experimental use. We thus propose that if care is taken in initial script development and if pragmatic choices are made regarding filming techniques and pilot-testing, researchers can produce valid vignettes within reasonable time and budget restraints. We also suggest that existing research fails to critically examine the potential benefits and harms of online video vignette methodology, and propose that further research should consider how it can be adapted to be inclusive of those from underserved backgrounds.

CONCLUSIONS

Researchers creating video vignette studies can adapt the video vignette development process to suit time and budget constraints, and to make best use of available technology. Online methods may be harnessed to increase participant accessibility, but future research should explore more inclusive vignette design.

Autonomic nervous system and endocrine system response to upper and lower cervical spine mobilization in healthy male adults: a randomized crossover trial

BACKGROUND

Cervical spine mobilizations may differentially modulate both components of the stress response, consisting of the autonomic nervous system and hypothalamic pituitary adrenal-axis, depending on whether the target location is the upper or lower cervical spine. To date, no study has investigated this.

METHODS

A randomized, crossover trial investigated the effects of upper versus lower cervical mobilization on both components of the stress response simultaneously. The primary outcome was salivary cortisol (sCOR) concentration. The secondary outcome was heart rate variability measured with a smartphone application. Twenty healthy males, aged 21-35, were included. Participants were randomly assigned to block-AB (upper then lower cervical mobilization, n = 10) or block-BA (lower than upper cervical mobilization, n = 10), separated by a one-week washout period. All interventions were performed in the same room (University clinic) under controlled conditions. Statistical analyses were performed with a Friedman's Two-Way ANOVA and Wilcoxon Signed Rank Test.

RESULTS

Within groups, sCOR concentration reduced thirty-minutes following lower cervical mobilization (p = 0.049). Between groups, sCOR concentration was different at thirty-minutes following the intervention (p = 0.018).

CONCLUSION

There was a statistically significant reduction in sCOR concentration following lower cervical spine mobilization, and between-group difference, 30 min following the intervention. This indicates that mobilizations applied to separate target locations within the cervical spine can differentially modulate the stress response.

DREAM5: An open-label, randomized, cross-over study to evaluate the safety and efficacy of day and night closed-loop control by comparing the MD-Logic automated insulin delivery system to sensor augmented pump therapy in patients with type 1 diabetes at home

AIMS

Previous DREAM studies demonstrated the safety and efficacy of the CE marked MD-Logic closed-loop system (DreaMed GlucoSitter) in different settings for overnight glycaemic control. The present study aimed to evaluate the system for day and night use for 60 hours during the weekend at home compared to sensor-augmented pump (SAP) therapy in participants with type 1 diabetes.

METHODS

This was a prospective, multicentre, crossover, controlled study (clinicaltrials.gov NCT01238406). All participants were connected in randomized order for one weekend to SAP therapy or the MD-Logic System. In the intervention arm only, the amount of carbohydrate was entered into the bolus calculator; the rest of insulin delivery was automated and wireless via a tablet computer. The primary endpoint was percentage of glucose values between 70 and 180 mg/dL.

RESULTS

The ITT population comprised 48 (19 males, 29 females) adolescents and adults experienced in sensor use: (median, [IQR]): age, 16.1years [13.2-18.5]; diabetes duration, 9.4 years [5.0-12.7]; pump use, 5.4 years [3.1-9.4]; HbA1c, 7.6% [7.0-8.1]. A significant increase in the percentage of time within target range (70-180 mg/dL) (66.6% vs 59.9%, P = 0.002) was observed with the closed-loop system vs control weekends with unchanged percentage of time below 70 mg/dL (2.3% vs 1.5%, P = 0.369). Mean weekend glucose level per participant was significantly lower (153 [142-175] vs 164 [150-186] mg/dL, P = 0.003). No safety signals were observed.

CONCLUSIONS

The MD-Logic system was safe and associated with better glycaemic control than SAP therapy for day and night use. The absence of remote monitoring did not lead to safety signals in adapting basal rates nor in administration of automated bolus corrections.

Effects of protein quantity and type on diet induced thermogenesis in overweight adults: A randomized controlled trial

BACKGROUND & AIMS

Protein content of a meal is hypothesized to drive DIT dose-dependently. However, no single meal study exists comparing two different doses of protein on DIT. In addition, the source of protein, particularly whey protein, was shown to have a higher DIT than casein and soy in the acute setting, however the mechanism behind this difference is not yet clear. The aim of the present work is therefore to evaluate the efficacy of two different doses and types of protein (whey protein and casein) on DIT in overweight adults.

METHODS

Randomized, double blind crossover including seventeen overweight men and women assigned to four isocaloric study treatments where protein and carbohydrate were exchanged: control, 30 g of whey protein microgels (WPM30), 50 g WPM (WPM50) or 50 g micellar casein (MC50). Energy expenditure was measured by indirect calorimetry. Blood, breath and urine samples were collected in order to measure substrate oxidation, amino acid profile, glucose and insulin, protein turnover and other metabolic parameters.

RESULTS

DIT was 6.7 ± 3.7%, 13.0 ± 5.0%, 18.0 ± 5.0% and 16.0 ± 5.0% for control, WPM30, WPM50 and MC50, respectively. There was a significant difference between WPM50 and WPM30 (p < 0.005) and a trend was observed between WPM50 and MC50 (p = 0.06). WPM50 resulted in the highest total, essential, and branched-chain plasma amino acid concentrations when compared with the other study treatments (p < 0.005) and a higher insulin concentration than MC50 (p < 0.005). Protein oxidation was higher for WPM50 than MC50. Protein turnover was significantly correlated with DIT through total leucine oxidation (r = 0.52, p = 0.005).

CONCLUSIONS

Our findings show that DIT does increase at a dose beyond 30 g of WPM and that the type of dairy protein may have an effect on DIT with WPM tending towards a higher DIT than casein. Although further research is required to understand the mechanism behind the effect of different protein sources on thermogenesis, we suggest that amongst the components of protein turnover, protein oxidation may be an important driver of thermogenesis at doses higher than 30 g. These results have concrete implications when choosing a dose of protein to optimize its thermogenic effect.

CLINICAL TRIAL REGISTRY NUMBER

NCT02303080 www.clinicaltrials.gov.

Adherence to Point-of-Use Water Treatment over Short-Term Implementation: Parallel Crossover Trials of Flocculation-Disinfection Sachets in Pakistan and Zambia

The health benefits of point-of-use (POU) water treatment can only be realized through high adherence: correct, consistent, and sustained use. We conducted parallel randomized, longitudinal crossover trials measuring short-term adherence to two single-use flocculant-disinfectant sachets in Pakistan and Zambia. In both trials, adherence declined sharply for both products over the eight week surveillance periods, with overall lower adherence to both products in Zambia. There was no significant difference in adherence between the two products. Estimated median daily production of treated water dropped over the crossover period from 2.5 to 1.4 L person^-1 day^-1 (46% decline) in Pakistan and from 1.4 to 1.1 L person^-1 day^-1 (21% decline) in Zambia. The percentage of surveillance points with detectable total chlorine in household drinking water declined from 70% to 49% in Pakistan and rose marginally from 28% to 30% in Zambia. The relatively low and decreasing adherence observed in this study suggests that these products would have provided little protection from waterborne disease risk in these settings. Our findings underscore the challenge of achieving high adherence to POU water treatment, even under conditions of short-term adoption with intensive follow-up.

Clinical Fitting and Adjustment Time for Implant-Supported Crowns Comparing Digital and Conventional Workflows

PURPOSE

The aim of this prospective cohort study was to investigate clinical and laboratory performance of implant-supported reconstructions comparing the digital to the conventional workflow.

MATERIALS AND METHODS

Twenty study participants were treated in a cross-over design for single-tooth replacement in posterior sites, each with a customized titanium abutment plus computer-assisted design and computer-assisted manufacturing (CAD/CAM)-zirconia-suprastructure (test: digital workflow; n = 20) and a standardized titanium abutment plus PFM-crown (control: conventional pathway; n = 20). Evaluation of the 40 reconstructions included: 1) feasibility of laboratory cross-mounting of each abutment-crown-connection, and 2) assessment of adaptation time for clinical adjustments of interproximal and occlusal surfaces. Statistical analyses were performed using the exact Wilcoxon rank sum tests.

RESULTS

Laboratory cross-mounting was feasible for three reconstruction pairings revealing a 15% vice versa transfer success rate. All implant crowns could be provided successfully within two clinical appointments, independently of the workflow used. The mean clinical adjustment time was significantly lower (p < .001) for test reconstructions from the digital workflow with 2.2 min (standard deviation [SD] ± 2.1) compared with the ones from the conventional pathway with 6.0 min (SD ± 3.9).

CONCLUSIONS

The digital workflow was almost threefold more efficient than the established conventional pathway for fixed implant-supported crowns. Clinical fitting could be predictably achieved with no or minor adjustments within the digital process of intraoral scanning plus CAD/CAM technology.

Transcription factor AP-2 beta genotype and psychosocial adversity in relation to adolescent depressive symptomatology

The aim of this study was to investigate possible interactions between the gene coding for activating protein-2 beta (AP-2 beta) and psychosocial factors to predict depressive symptoms in adolescents. Two-hundred 16- and 19-year-old adolescents from the county of Västmanland, Sweden, were asked to complete a questionnaire, interviewed about psychosocial risk factors, and genotyped with regard to the transcription factor AP-2 beta intron 2 polymorphism. AP-2 beta genotype interacted significantly both with type of housing and parental separation to predict depressive symptoms. Individuals who were homozygous for the short AP-2 beta allele displayed higher depression scores when psychosocial adversity was taken into account. Amongst carriers of one or two copies of the long allele, there was no difference in depressive symptoms despite differences in psychosocial environments.

The MAO-A gene, platelet MAO-B activity and psychosocial environment in adolescent female alcohol-related problem behaviour

BACKGROUND

Antisocial behaviour has been associated with polymorphic variants in candidate genes and recently also gene-environmental interaction models have been presented. It has been suggested that antisocial behaviour, associated with alcohol consumption in males, is related to a variation in the monoamine oxidase A gene (MAO-A) promoter. Furthermore, platelet MAO-B activity has in several studies been reported to be low in male alcoholics, while this has not been the case with regard to female alcoholics. Aims of the present study were to: (1) investigate possible interactions between the MAO-A polymorphism, family relations and maltreatment/sexual abuse on adolescent alcohol-related problem behaviour among female adolescents; (2) to investigate if platelet MAO-B enzyme activity interacted with environment to predict female alcohol-related problems.

METHODS

A random sample of 114 female individuals from a total population of 16- and 19-year adolescents from a Swedish county, who volunteered to participate in the study, were interviewed, filled in a questionnaire and a blood sample was drawn.

RESULTS

In contrast to what has been reported in males, presence of the long (4-repeat) variant of the MAO-A gene in females interacted significantly with an unfavourable environment (poor family relations or maltreatment/abuse/sexual abuse) to increase the risk for high scores of alcohol-related problems. Furthermore, females with low platelet MAO-B activity showed an increased risk of alcohol-related problem behaviour in an unfavourable environment.

CONCLUSIONS

Poor psychosocial environment interacts with the high activity MAO-A genotype and low platelet MAO-B enzyme activity to increase vulnerability for female adolescent alcohol-related problem behaviour.

The monoamine oxidase A (MAO-A) gene, family function and maltreatment as predictors of destructive behaviour during male adolescent alcohol consumption

AIM

To investigate possible interactions between a polymorphism in the monoamine oxidase A (MAO-A) gene promoter, family relations and maltreatment/sexual abuse on adolescent alcohol-related problem behaviour among male adolescents.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional study of a randomized sample of 66 male individuals from a total population of 16- and 19-year adolescents from a Swedish county. Boys, who volunteered to participate answering an alcohol-related problem/behaviour questionnaire, were investigated with regard to interactions between such problems, family function, maltreatment and MAO-A genotype.

MEASUREMENTS

MAO-A genotype, family relations history, history of being maltreated or abused and alcohol-related problem behaviour.

FINDINGS

Boys with the short (three-repeat) variant of the MAO-A gene, who had been maltreated/abused or came from families with poor relations, showed significantly higher scores of alcohol-related problems. We also found that maltreatment/abuse independently showed the strongest relation to alcohol-related problems among boys in our model.

CONCLUSIONS

The results suggest that both maltreatment and MAO-A genotype may be useful for the understanding of male adolescent alcohol-related problem behaviour.