The Maximal Intensity Period: Rationalising its Use in Team Sports Practice

Quantifying the highest intensity of competition (the maximal intensity period [MIP]) for varying durations in team sports has been used to identify training targets to inform the preparation of players. However, its usefulness has recently been questioned since it may still underestimate the training intensity required to produce specific physiological adaptations. Within this conceptual review, we aimed to: (i) describe the methods used to determine the MIP; (ii) compare the data obtained using MIP or whole-match analysis, considering the influence of different contextual factors; (iii) rationalise the use of the MIP in team sports practice and (iv) provide limitations and future directions in the area. Different methods are used to determine the MIP, with MIP values far greater than those derived from averaging across the whole match, although they could be affected by contextual factors that should be considered in practice. Additionally, while the MIP might be utilised during sport-specific drills, it is inappropriate to inform the intensity of interval-based, repeated sprint and linear speed training modes. Lastly, MIP does not consider any variable of internal load, a major limitation when informing training practice. In conclusion, practitioners should be aware of the potential use or misuse of the MIP.

Subcutaneous and visceral adipose tissue in patients with primary and recurrent incisional hernia

PURPOSE

Visceral obesity rather than body mass index has been reported to be associated with a higher incidence of incisional hernias. The aim of this study was to examine the relationship between CT measured adipose tissue and muscle in primary and recurrent incisional hernia.

METHODS

Patients with a 'Primary' or 'Recurrent incisional hernia' were obtained from a prospective cohort of patients who were being assessed for incisional hernia repair over a 2-year period. Computerised tomography (CT)-images were analysed using NIH Image-J software to quantify adipose tissue and skeletal muscle cross-sectional areas at the level of lumber vertebra 3/4 using standard Hounsfield units. To test inter-observer 'absolute agreement', each parameter was measured independently by two investigators and reliability analysis performed.

RESULTS

Thirty-six patients were included in the study: 15 had a Primary while 21 had a Recurrent incisional hernia. Both groups had similar baseline characteristics. Reliability analysis for CT-measured areas showed very high interclass correlation coefficient (ICC) between observers. Patients in the recurrent group had significantly greater subcutaneous adipose tissue (SAT) [median = 321.9cm2 vs 230.9cm2, p = 0.04] and visceral adipose tissue (VAT) [median = 221.1cm2 vs 146.8cm2, p = 0.03] than those in the primary group. There was no difference in skeletal muscle areas for right [median = 2.8cm2 vs 2.9cm2] and left [median = 3.7cm2 vs 4.1cm2] rectus muscles between groups.

CONCLUSION

Our study shows that patients with a recurrent incisional hernia have significantly more subcutaneous and visceral adipose tissue than those with a primary incisional hernia. Further studies in this area are required if we are to reduce the burden of recurrent hernia following repair of a primary incisional hernia.

A230 THE ROLE OF THE MICROBIOTA IN NOCICEPTOR DEVELOPMENT AND PAIN SENSITIVITY

Background

Pain is the most common cause of disability in IBD. What causes inter-individual variability in chronic pain after successful treatment of inflammation remains elusive. We have shown that activation of TRPV1+ colonic nociceptors is essential for the establishment of persistent pain in DSS colitis. Nociceptor development coincides with microbial colonization, while early life dysbiosis can lead to visceral hypersensitivity in adulthood. Whether the microbiota dictates nociceptor development and pain susceptibility remains unknown. Here we test the hypothesis that the microbiota programs nociceptor specification during early development, rendering them more susceptible to sensitization later in life. We have identified the aryl hydrocarbon receptor (AHR) that senses bacterial-derived metabolites as a candidate target that orchestrates transcriptional regulation in nociceptors.

Aims

We investigated the developmental regulation of nociceptors by the microbiome and how it influences pain sensitivity. We will determine the effects of AHR activation on nociceptor lineage and function as well as the long term impact of AHR signaling on pain sensitivity.

Methods

We have developed a germ-free (GF) TRPV1-GFP reporter mouse that was used to phenotype and visualise TRPV1+ nociceptors in the absence of a microbiota. We will isolate TRPV1+ neurons by FACS to identify genes that are under the control of the microbiota and to characterise the phosphoproteome of TRPV1+ nociceptors in GF conditions. Finally, we will investigate the role of AHR signaling in nociceptors both acutely and during development.

Results

We showed a reduction in thermal pain threshold and a reduction in capsaicin test responses in GF mice. The number and size of DRG neurons was unchanged in GF mice. Examination of molecular markers for peptidergic (CGRP) and non-peptidergic (IB4) neurons did not show a difference. Finally, there was no difference in the expression of TRPV1, suggesting post-translational modification of the channel. In cultured DRG neurons, we found a decrease in capsaicin induced action potentials and a decrease in the amplitude of the capsaicin response in GF mice. Using RNAscope, we showed that TRPV1+ neurons express AHR.

Conclusions

Our results highlight the importance of bacterial composition in regulating the development of nociceptors and pain sensitivity in adulthood. Furthermore, we are the first to demonstrate the expression of AHR in sensory neurons. These findings point to a role of the microbiota in programming nociceptors during development. My work will advance our understanding of the role of commensal bacteria in regulating pain and could lead to recommendations for the treatment of neonates in early life to reduce their risk of developing chronic pain later in life.

Funding Agencies

CAG, CIHR

The Between-Competition Running Demands of Elite Hurling Match-Play

The current study aimed to investigate the differences in running demands between the National Hurling League (NHL) and the Championship, and within playing positions. GPS (10 Hz, STATSports Apex GNSS) were used to analyse the running demands during 34 games (2017–2020 seasons) of the Championship and the NHL. The running demands (total-, relative-, high-speed- [>17 km·h⁻¹] and sprint [≥22 km·h⁻¹] distance, number and length of sprints, and peak speed) were compared between competitions. Greater total- [ES = 0.32], relative- [ES = 0.26], and sprint-distance [ES = 0.41], and number of sprints [ES = 1.29] were completed in the Championship. The high-speed distance was similar between competitions. Half-backs and half-forwards covered greater total- (ES = 0.91 and 0.21, respectively), relative- (ES = 1.14 and 0.68, respectively), high-speed- (ES = 0.69 and 0.44, respectively), and sprint-distance (ES = 0.50 and 1.26, respectively), number of sprints (ES = 2.66 and 1.73, respectively), and peak speed (ES = 1.09 and 1.32, respectively) in the Championship. There was no difference (p < 0.05) in the sprint distance covered between positions in the Championship. The results showed that the Championship is more physically demanding. The findings present key implications for the transition between competitions.

Clinical features and presentation of cervicofacial infection: a Maxillofacial Trainee Research Collaborative (MTReC) study

Cervicofacial infection (CFI) is a common presentation to the Oral and Maxillofacial (OMFS) department and accounts for significant emergency activity. The current study aims to understand the aetiology, management, and clinical features of patients hospitalised with CFI. Our study included all patients admitted for management of CFI from May to October 2017 at 25 OMFS units across 17 UK regions. Data were collected prospectively and included age, comorbidities, prior treatment received, markers of sepsis, and presenting clinical features. One thousand and two (1002) admissions were recorded; 546 (54.5%) were male. Median (range) age was 34 (1-94) years. The most common presenting complaints were trismus (46%) and dysphagia (27%). Airway compromise was present in 1.7% of cases. Odontogenic infection accounted for 822/1002 (82%) admissions. Of those with an infection of odontogenic origin, 453/822 (55.1%) had received previous treatment. Two-thirds of those who had received treatment were managed by antibiotics alone (300/453, 66.2%). Patients met criteria for sepsis in 437/1002 (43.6%) of CFI, and in 374/822 (45.5%) of odontogenic infections. This is the largest study worldwide of patients requiring inpatient management for CFI. Infection due to odontogenic origin is the most frequent reason for admission and nearly half do not seek treatment before presentation. Patients with CFI often present late in their disease and frequently meet criteria for sepsis, requiring timely and aggressive treatment to ensure optimum outcomes. Trismus is an emerging dominant feature with all the implications related to the anaesthetic management of these patients. Knowledge of these factors has implications for the referrer, triage, the emergency department, the anaesthetic team, and members of the OMFS team.

Identification of Maximal Running Intensities During Elite Hurling Match-Play

Young, D, Malone, S, Beato, M, Mourot, L, and Coratella, G. Iidentification of maximal running intensities during elite hurling match-play. J Strength Cond Res 34(9): 2608-2617, 2020-The current study aimed to describe the duration-specific running intensities of elite hurling players during competition with respect to position using a rolling average method. Global positioning systems (10-Hz Viper; STATSport, Viper, Newry, Northern Ireland) were used to collect data from 36 elite hurling players across 2 seasons. Players were categorized according to playing positions (full-backs, half-backs, midfielders, half-forwards, and full-forwards). A total of 230 full match samples were obtained from 22 competitive games for analysis. The velocity-time curve was analyzed using a rolling average method, in which the maximum relative total distance (TD; m·min), high-speed running distance (HSR; m·min), and sprint distance (SD; m·min) intensities were calculated across 10 different rolling time durations (1-10 minutes) within each game. There were large to very large (effect sizes [ES] = 0.66-4.33) differences between 1 minute rolling averages and all other durations for TD, HSR, and SD. However, pairwise comparisons between 6 and 10 minutes for TD, HSR, and SD were smaller and more variable (ES = 0.07, trivial to ES = 0.85, moderate). Half-backs, midfielders, and half-forwards achieved a higher maximal relative TD and HSR in all duration-specific fields when compared with full-backs and full-forwards. No positional difference was observed in 1- and 2-minute durations for SD. Because the rolling average duration increased the maximum TD, HSR and SD running intensities decreased across all positions. These data provide knowledge of the peak running intensities of elite hurling competition and can be used to design training activities to sufficiently prepare players for these "worst-case scenarios."

Match-Play Temporal and Position-Specific Physical and Physiological Demands of Senior Hurlers

Young, D, Beato, M, Mourot, L, and Coratella, G. Match-play temporal and position-specific physical and physiological demands of senior hurlers. J Strength Cond Res 34(6): 1759-1768, 2020-The aims of the current study were to examine the temporal differences in match-running performances and heart rate (HR) in elite senior hurling players between halves of play and field positions. Global positioning systems (10 Hz) and HR monitors were used to collect data from 48 players over 18 games. Running performances (total distance [TD], relative distance, high-speed running [HSR], sprint efforts [SE], mean length of sprints, and sprint distance [SD]) and HR values (HRmean and HRpeak) were assessed. Decrements in TD (p = 0.009, effect size [ES] = -0.15), relative distance (p = 0.009, ES = -0.18), HSR (p = 0.001, ES = -0.28), SE (p = 0.001, ES = -0.23), SD (p = 0.001, ES = -0.24), HRmean (p < 0.001, ES = -0.38), and HRpeak (p < 0.001, ES = -0.21) were found between halves. Half backs showed between-half decrements in all metrics (p < 0.05) except SD (p = 0.130, ES = -0.26). Midfielders (p < 0.001, ES = -0.68) and half forwards (p < 0.001, ES = -0.79) experienced second-half decrements in HSR. No decrements (p > 0.05) in running performances were found between halves for full backs. HRmean was lower in full backs (p = 0.007, ES = -0.46) and half backs (p = 0.001, ES = -0.76) in the second half. Coaches should consider the specific HSR between-half temporal decrements in half backs, midfielders, and half forwards, and customize training program design to minimize these decrements.

Metabolic power in hurling with respect to position and halves of match-play

The current investigation compared the metabolic power and energetic characteristics in team sports with respect to positional lines and halves of match-play. Global positioning system (GPS) technology data were collected from 22 elite competitive hurling matches over a 3-season period. A total of 250 complete match-files were recorded with players split into positional groups of full-back; half-back; midfield; half-forward; full-forward. Raw GPS data were exported into a customized spreadsheet that provided estimations of metabolic power and speed variables across match-play events (average metabolic power [P_met], high metabolic load distance [HMLD], total distance, relative distance, high-speed distance, maximal speed, accelerations, and deceleration). P_met, HMLD, total, relative and high-speed distance were 8.9 ± 1.6 W·kg^-1, 1457 ± 349 m, 7506 ± 1364 m, 107 ± 20 m·min^-1 and 1169 ± 260 m respectively. Half-backs, midfielders and half-forwards outperformed full-backs (Effect Size [ES] = 1.03, 1.22 and 2.07 respectively), and full-forwards in P_met (Effect Size [ES] = 1.70, 2.07 and 1.28 respectively), and HMLD (full-backs: ES = -1.23, -1.37 and -0.84 respectively, and full-forwards: ES = -1.77, -2.00 and -1.38 respectively). Half-backs (ES = -0.60), midfielders (ES = -0.81), and half-forwards (ES = -0.74) experienced a second-half temporal decrement in HMLD. The current investigation demonstrates that metabolic power may increase our understanding of the match-play demands placed on elite hurling players. Coaches may utilize these findings to construct training drills that replicate match-play demands.

Accuracy of contrast-enhanced CT and predictive factors for extracapsular spread in unknown primary head and neck squamous cell cancer

AIM

To determine the accuracy of contrast-enhanced computed tomography (CECT) for nodal extracapsular spread (ECS) and identify predictive radiological signs and clinicopathological features for ECS in unknown-primary head and neck squamous cell cancer (UPHNSCC).

MATERIALS AND METHODS

The CECT imaging of patients who underwent primary neck dissection for UPHNSCC during 2011-2015 was analysed. The largest pathological-looking node at each radiologically involved level was evaluated in consensus by two head and neck radiologists. Parameters included longest diameter, margin sharpness, haziness in adjacent fat, necrosis, and loss of fat plane with adjacent structures. Independent assessment was also made regarding the presence/absence of ECS. Findings and clinicopathological parameters were correlated with histopathology.

RESULTS

Thirty-one patients with 39 neck levels had metastatic nodal involvement determined on CECT. Confirmed ECS was found at 26 levels in 23 patients. Sensitivity of radiological assessment for ECS by nodal level was 81-85% (95% confidence interval [CI]=65-93%) and specificity 46-54% (95% CI=19-81%); kappa 0.87. On univariate analysis based on the largest involved node per patient, longest diameter being ≥30 mm (p=0.007), haziness in adjacent fat (p=0.023), increasing age (p=0.006), and more advanced pathological nodal status (p=0.027) were statistically significantly associated with ECS. Haziness and increasing age were independent predictors on multivariate analysis (odds ratio [OR]=26.4 and 1.24).

CONCLUSION

Expert assessment of ECS on CECT had good sensitivity with excellent interobserver agreement. A longest nodal diameter of ≥30 mm, haziness in the surrounding fat on CECT, advanced pathological nodal status, and advancing patient age were significantly associated with ECS in UPHNSCC patients, findings not previously reported.

Signal processing methods for reducing artifacts in microelectrode brain recordings caused by functional electrical stimulation

OBJECTIVE

Functional electrical stimulation (FES) is a promising technology for restoring movement to paralyzed limbs. Intracortical brain-computer interfaces (iBCIs) have enabled intuitive control over virtual and robotic movements, and more recently over upper extremity FES neuroprostheses. However, electrical stimulation of muscles creates artifacts in intracortical microelectrode recordings that could degrade iBCI performance. Here, we investigate methods for reducing the cortically recorded artifacts that result from peripheral electrical stimulation.

APPROACH

One participant in the BrainGate2 pilot clinical trial had two intracortical microelectrode arrays placed in the motor cortex, and thirty-six stimulating intramuscular electrodes placed in the muscles of the contralateral limb. We characterized intracortically recorded electrical artifacts during both intramuscular and surface stimulation. We compared the performance of three artifact reduction methods: blanking, common average reference (CAR) and linear regression reference (LRR), which creates channel-specific reference signals, composed of weighted sums of other channels.

MAIN RESULTS

Electrical artifacts resulting from surface stimulation were 175  ×  larger than baseline neural recordings (which were 110 µV peak-to-peak), while intramuscular stimulation artifacts were only 4  ×  larger. The artifact waveforms were highly consistent across electrodes within each array. Application of LRR reduced artifact magnitudes to less than 10 µV and largely preserved the original neural feature values used for decoding. Unmitigated stimulation artifacts decreased iBCI decoding performance, but performance was almost completely recovered using LRR, which outperformed CAR and blanking and extracted useful neural information during stimulation artifact periods.

SIGNIFICANCE

The LRR method was effective at reducing electrical artifacts resulting from both intramuscular and surface FES, and almost completely restored iBCI decoding performance (>90% recovery for surface stimulation and full recovery for intramuscular stimulation). The results demonstrate that FES-induced artifacts can be easily mitigated in FES  +  iBCI systems by using LRR for artifact reduction, and suggest that the LRR method may also be useful in other noise reduction applications.

Genomic determinants of speciation and spread of the Mycobacterium tuberculosis complex

Models on how bacterial lineages differentiate increase our understanding of early bacterial speciation events and the genetic loci involved. Here, we analyze the population genomics events leading to the emergence of the tuberculosis pathogen. The emergence is characterized by a combination of recombination events involving core pathogenesis functions and purifying selection on early diverging loci. We identify the phoR gene, the sensor kinase of a two-component system involved in virulence, as a key functional player subject to pervasive positive selection after the divergence of the Mycobacterium tuberculosis complex from its ancestor. Previous evidence showed that phoR mutations played a central role in the adaptation of the pathogen to different host species. Now, we show that phoR mutations have been under selection during the early spread of human tuberculosis, during later expansions, and in ongoing transmission events. Our results show that linking pathogen evolution across evolutionary and epidemiological time scales points to past and present virulence determinants.

Increase in CFC-11 emissions from eastern China based on atmospheric observations

The recovery of the stratospheric ozone layer relies on the continued decline in the atmospheric concentrations of ozone-depleting gases such as chlorofluorocarbons¹. The atmospheric concentration of trichlorofluoromethane (CFC-11), the second-most abundant chlorofluorocarbon, has declined substantially since the mid-1990s². A recently reported slowdown in the decline of the atmospheric concentration of CFC-11 after 2012, however, suggests that global emissions have increased^3,4. A concurrent increase in CFC-11 emissions from eastern Asia contributes to the global emission increase, but the location and magnitude of this regional source are unknown³. Here, using high-frequency atmospheric observations from Gosan, South Korea, and Hateruma, Japan, together with global monitoring data and atmospheric chemical transport model simulations, we investigate regional CFC-11 emissions from eastern Asia. We show that emissions from eastern mainland China are 7.0 ± 3.0 (±1 standard deviation) gigagrams per year higher in 2014-2017 than in 2008-2012, and that the increase in emissions arises primarily around the northeastern provinces of Shandong and Hebei. This increase accounts for a substantial fraction (at least 40 to 60 per cent) of the global rise in CFC-11 emissions. We find no evidence for a significant increase in CFC-11 emissions from any other eastern Asian countries or other regions of the world where there are available data for the detection of regional emissions. The attribution of any remaining fraction of the global CFC-11 emission rise to other regions is limited by the sparsity of long-term measurements of sufficient frequency near potentially emissive regions. Several considerations suggest that the increase in CFC-11 emissions from eastern mainland China is likely to be the result of new production and use, which is inconsistent with the Montreal Protocol agreement to phase out global chlorofluorocarbon production by 2010.

The match-play sprint performance of elite senior hurlers during competitive games

The typical sprint profile in elite hurling has yet to be established. The purpose of this study was to investigate the sprinting demands of elite hurling competition and characterize the sprinting patterns of different playing positions. GPS (10-Hz, STATSports Viper) were used to collect data from 51 hurlers during 18 games. The total sprint (≥22 km·h-1) distance (TSD), the number of sprints (NOS) classified as length (<20 m, ≥20 m) and relative speed thresholds (<80%, 80-90%, >90%), the between-sprint duration and the number of repeated-sprint bouts (≥2 sprints in ≤60 s) were analyzed. The NOS was 22.2 ± 6.8 accumulating 415 ± 140 m TSD. The NOS <20 m, ≥20 m was 14.0 ± 4.7 and 8.1 ± 3.6 respectively. The NOS <80%, 80-90% and >90% was 10.6 ± 4.3, 8.2 ± 3.6, 3.4 ± 2.4 respectively. The between-sprint duration and the repeated-sprint bouts were 208 ± 86 s and 4.5 ± 2.6 respectively. TSD (ES = -0.20), NOS (ES = -0.34), NOS <20 m (ES = -0.33), ≥20 m (ES = -0.24), 80-90% (ES = -0.35) >90% (ES = -0.13) and repeated-sprint bouts (ES = -0.28) decreased between-halves. Full-backs performed a lower NOS <80% than half-backs (ES = -0.66) and a shorter mean duration of sprints than half-backs (ES = -0.75), midfielders (ES = -1.00) and full-forwards (ES = -0.59). These findings provide a sprint profile of elite hurling match-play that coaches should consider to replicate the sprint demands of competition in training.

GooD4Mum: A general practice-based quality improvement collaborative for diabetes prevention in women with previous gestational diabetes

AIMS

Gestational diabetes (GDM) and Type 2 diabetes pose tremendous health and economic burdens as worldwide incidence increases. Primary care-based systematic diabetes screening and prevention programs could be effective in women with previous GDM. GooD4Mum aimed to determine whether a Quality Improvement Collaborative (QIC) would improve postpartum diabetes screening and prevention planning in women with previous GDM in general practice.

METHODS

Fifteen general practices within Victoria (Australia) participated in a 12-month QIC, consisting of baseline and four quarterly audits, guideline-led workshops and Plan-Do-Study-Act feedback cycles after each audit. The primary outcome measures were the proportion of women on local GDM registers completing a diabetes screening test and a diabetes prevention planning consultation within the previous 15 months.

RESULTS

Diabetes screening increased with rates more than doubled from 26% to 61% and postpartum screening increased from 43%-60%. Diabetes prevention planning consultations did not show the same level of increase (0%-10%). The recording of body mass index improved overall (51%-69%) but the number of women with normal body mass index did not.

CONCLUSIONS

GooD4Mum supported increased diabetes screening and the monitoring of high risk women with previous GDM in general practice.

Match-Play Demands of Elite U17 Hurlers During Competitive Matches

Young, D, Mourot, L, Beato, M, and Coratella, G. Match-play demands of elite U17 hurlers during competitive matches. J Strength Cond Res 34(7): 1982-1989, 2020-The current study aimed to quantify the match-play workload in elite male under 17 hurlers, measuring the differences between the first and second halves and between positions. Global positioning system (10-Hz) and heart rate monitors were used to collect data from 76 players during 18 matches. Players' total distance (TD), relative distance (RD), high-speed running (HSR), the number and length of sprints, and the total sprint distance (TSD) was 6,483 ± 1,145 m, 108 ± 19 m·min, 583 ± 215 m, 18 ± 6, 15 ± 3 m, and 272 ± 77 m, respectively. Peak and mean heart rate were 194 ± 8 b·min and 167 ± 4 b·min, respectively. Decrements in TD (p < 0.001, effect size [ES] = 0.72), RD (p < 0.001, ES = 0.72), HSR (p < 0.001, ES = 0.55), the number of sprints (p < 0.001, ES = 0.57), mean length of sprint (p < 0.011, ES = 0.25), TSD (p < 0.001, ES = 0.69), mean heart rate (p < 0.001, ES = 0.35), and peak heart rate (p < 0.001, ES = 0.52) were found between halves. Largely-to-very largely greater TD, RD, and HSR were covered by midfielders, half-backs, and half-forwards compared with full-backs and full-forwards. No between-position difference was found in peak and mean heart rate. The current results are the first to highlight the differences in external and internal position-specific workload in elite male under 17 hurlers. Coaches need to consider the position-specific demands and between-half drop-off to prepare young hurlers appropriately to repeat the match-play performances of competition.

The Match Heart Rate and Running Profile of Elite Under-21 Hurlers During Competitive Match-Play

Young, D, Mourot, L, Beato, M, and Coratella, G. The match heart rate and running profile of elite under-21 hurlers during competitive match-play. J Strength Cond Res 32(10): 2925-2933, 2018-The aims of the current study were to examine the physical and physiological demands of elite under-21 male hurling match-play across halves of play and between positions. Global positioning systems (10 Hz) and heart rate (HR) monitors were used to collect data from 95 players during 10 games. Total distance (TD), relative speed, high-speed running (HSR), sprint distance, total sprints, and mean length of sprint was 6,688 ± 942 m, 112 ± 16 m·min, 661 ± 203 m, 274 ± 111 m, 18 ± 8 m, and 16 ± 5 m, respectively. Players' mean HR (HRmean) and peak HR (HRpeak) was 165 ± 9 b·min and 190 ± 7 b·min, respectively. Decrements in TD (p < 0.05, effect size [ES] = 0.81), HSR (p < 0.05, ES = 0.69), and HRmean (p < 0.05, ES = 0.80) were found between halves. Full backs covered significantly less TD than half backs (p < 0.05, ES = -1.24), midfielders (p < 0.05, ES = -1.39), and half forwards (p < 0.05, ES = -1.85). Half forwards covered a greater TD than full forwards (p < 0.05, ES = 0.94), greater HSR than full backs (p < 0.05, ES = 1.13), and greater sprint distance than half backs (p < 0.05, ES = 1.41). Between-half decreases were evident in TD, HSR, and HRmean, with no significant positional differences observed in TD, HSR, number of sprints, length of sprint, HRpeak, and HRmean between half backs, midfielders, and half forwards. The current findings provide data that coaches should consider to customize training program design for under-21 hurlers.

Infertility patients with chromosome inversions are not susceptible to an inter-chromosomal effect

PURPOSE

The aim of this study was to evaluate the incidence of an inter-chromosomal effect (ICE) in blastocyst-stage embryos from carriers of balanced chromosome inversions.

METHODS

Infertility patients (n = 52) with balanced inversions (n = 66 cycles), and maternal age-matched controls that concurrently cycled (n = 66), consented to an IVF cycle with preimplantation genetic testing for aneuploidy (PGT-A). Blastocyst-stage embryos underwent trophectoderm biopsy for PGT-A with only euploid blastocysts transferred in a subsequent frozen embryo transfer. Subtypes of inversions were included in aggregate: paracentric/pericentric, polymorphic/non-polymorphic, male/female carriers, and varying inversion sizes.

RESULTS

The incidence of aneuploidy was not significantly higher for the inversion patients compared to the controls (inversion = 48.8% vs. control = 47.2% ns). Following euploid blastocyst transfer, there were excellent live birth outcomes.

CONCLUSIONS

Carriers of balanced chromosome inversions did not exhibit higher aneuploidy rates for chromosomes that were not involved in the inversion compared to maternal age-matched controls, signifying the absence of an inter-chromosomal effect for this data set. These results provide the largest investigation of blastocyst embryos regarding the debated existence of an ICE resulting from the presence of an inversion during meiosis. However, further studies are warranted to investigate an ICE among inversions subtypes that were outside the scope of this study.

Individual patient data analysis of tidal volumes used in three large randomized control trials involving patients with acute respiratory distress syndrome

Background.

The acute respiratory distress syndrome (ARDS) is a condition with a high mortality and morbidity. Mechanical ventilation prevents immediate mortality but may further damage patients' lungs. Low tidal volume lung-protective strategies have been shown to increase survival by reducing this iatrogenic damage. Current guidelines recommend tidal volumes of 6-8 ml kg -1 of predicted body weight. We used data from three large randomized controlled trials of treatments for ARDS to determine compliance with these recommendations.

Methods.

We used the tidal volume recorded at randomization for all patients in the OSCAR, HARP-2, and BALTI-2 studies. In addition, we used the ventilation data for control arm patients in OSCAR and all patients in HARP-2 at days 1 and 7 after randomization.

Results.

The three trials enrolled 1660 patients, with tidal volume data available at least at one time point in 1412 patients. Compliance with the 6-8 ml kg -1 recommendation for tidal volume ranged from 20 to 39% of patients across all time points in all three trials.

Conclusion.

Poor compliance with the guidelines for tidal volume in patients with ARDS has been demonstrated before in case series, but not in clinical trials where the patient population is specifically selected against standard ARDS diagnostic criteria and the investigators were encouraged to use low tidal volumes. This study may indicate a need to improve implementation and compliance with protective lung ventilation.

Closed-loop cortical control of virtual reach and posture using Cartesian and joint velocity commands

OBJECTIVE

Brain-computer interfaces (BCIs) are a promising technology for the restoration of function to people with paralysis, especially for controlling coordinated reaching. Typical BCI studies decode Cartesian endpoint velocities as commands, but human arm movements might be better controlled in a joint-based coordinate frame, which may match underlying movement encoding in the motor cortex. A better understanding of BCI controlled reaching by people with paralysis may lead to performance improvements in brain-controlled assistive devices.

APPROACH

Two intracortical BCI participants in the BrainGate2 pilot clinical trial performed a visual 3D endpoint virtual reality reaching task using two decoders: Cartesian and joint velocity. Task performance metrics (i.e. success rate and path efficiency) and single feature and population tuning were compared across the two decoder conditions. The participants also demonstrated the first BCI control of a fourth dimension of reaching, the arm's swivel angle, in a 4D posture matching task.

MAIN RESULTS

Both users achieved significantly higher success rates using Cartesian velocity control, and joint controlled trajectories were more variable and significantly more curved. Neural tuning analyses showed that most single feature activity was best described by a Cartesian kinematic encoding model, and population analyses revealed only slight differences in aggregate activity between the decoder conditions. Simulations of a BCI user reproduced trajectory features seen during closed-loop joint control when assuming only Cartesian-tuned features passed through a joint decoder. With minimal training, both participants controlled the virtual arm's swivel angle to complete a 4D posture matching task, and achieved significantly higher success using a Cartesian  +  swivel velocity decoder compared to a joint velocity decoder.

SIGNIFICANCE

These results suggest that Cartesian velocity command interfaces may provide better BCI control of arm movements than other kinematic variables, even in 4D posture tasks with swivel angle targets.

Fludrocortisone-a treatment for tubulopathy post-paediatric renal transplantation: A national paediatric nephrology unit experience

Calcineurin inhibitors post-renal transplantation are recognized to cause tubulopathies in the form of hyponatremia, hyperkalemia, and acidosis. Sodium supplementation may be required, increasing medication burden and potentially resulting in poor compliance. Fludrocortisone has been beneficial in addressing tubulopathies in adult studies, with limited paediatric data available. A retrospective review of data from an electronic renal database from December 2014 to January 2016 was carried out. Forty-seven post-transplant patients were reviewed with 23 (49%) patients on sodium chloride or bicarbonate. Nine patients, aged 8.3 years (range 4.9-16.4), commenced fludrocortisone 22 months (range 1-80) after transplant and were followed up for 9 months (range 2-20). All patients stopped sodium bicarbonate; all had a reduction or no increase in total daily doses of sodium chloride. Potassium levels were significantly lower on fludrocortisone, 5.2 vs 4.5 mmol/L, P = .04. No difference was noted in renal function (eGFR 77.8 vs 81.7 mL/min/1.73 m² , P = .45) and no significant increase in systolic blood pressure (z-scores 0.99 vs 0.85, P = .92). No side effects secondary to treatment with fludrocortisone were reported. A significant proportion of renal transplant patients were on sodium supplementation and fludrocortisone reduced sodium supplementation without significant effects on renal function or blood pressure. Fludrocortisone appears to be safe and effective for tubulopathies in children post-transplantation.

Metabolic and Distribution Studies with Radiolabeled 5-Fluorouracil

5-Fluorouracil (5-FU) is an effective anti-tumor drug, which has been used both as a single agent and in combination with other chemotherapeutic agents for the treatment of tumors such as breast and colorectal carcinoma. We synthesized 5-FU with trace amounts of 18F-5-FU and administered the compounds intravenously to 6 cancer patients. The patients were scanned at 2 hr intervals for 12 hrs and their urine collected whenever possible. We also injected 5-FU with the tracer 18F-5-FU, at pharmacological doses, into non-tumored rats, and sampled their bile and blood for 95 mins post-injection. For comparison, 2-14C-5-FU was injected into non-tumored rats and their bile and blood sampled at the same intervals. Minute quantities of rat bile and serum were analyzed chromatographically by high-performance TLC. 5-FU and two of its metabolites (FBAL and FUPA) were identified and quantified by this technique. Both percentage and absolute amounts of 5-FU in the bile follow comparative kinetic patterns. While the liver and the urinary bladder were clearly observable in all 6 patients, the detectability of the gall-bladder was correlated to the inverse of the alkaline phosphatase level in the blood. This work suggests that the diversity of the 5-FU metabolism in cancer patients may allow the use of 18F-5-FU as a probe for understanding those individual variabilities in clinical situations.

Sepsis caused by bloodstream infection in patients in the intensive care unit: the impact of inactive empiric antimicrobial therapy on outcome

BACKGROUND

Sepsis is one of the leading causes of death in the UK.

AIMS

To identify the rate of inactive antimicrobial therapy (AMT) in the intensive care unit (ICU) and whether inactive AMT has an effect on in-hospital mortality, ICU mortality, 90-day mortality and length of hospital stay. A further aim was to identify risk factors for receiving inactive AMT.

METHODS

This was a retrospective observational study conducted at Glasgow Royal Infirmary ICU between January 2010 and December 2013. In total, 12,000 blood cultures were taken over this time period, of which 127 were deemed clinically significant. Multi-variate logistic regression was used to identify risk factors independently associated with mortality. Univariate analysis followed by multi-variate analysis was performed to identify risk factors for receiving inactive AMT.

RESULTS

The rate of inactive AMT was 47% (N = 60). Multi-variate analysis showed that receiving antibiotics within the first 24h of ICU admission led to reduced mortality [relative risk 1.70, 95% confidence interval (CI) 1.19-2.44]. Furthermore, it showed that severity of illness (as defined by SIRS criteria sepsis vs septic shock) increased mortality [odds ratio (OR) 9.87, 95% CI 1.73-55.5]. However, inactive AMT did not increase mortality (OR 1.07, 95% CI 0.47-2.41) or length of hospital stay (53.2 vs 69.1 days, P = 0.348). Fungal bloodstream infection was found to be a risk factor for receiving inactive AMT (OR 5.10, 95% CI 1.29-20.14).

CONCLUSION

Mortality from sepsis is influenced by multiple factors. This study was unable to demonstrate that inactive AMT had an effect on mortality in sepsis.

Comparison of Fetal Rabbit Brain Xenografts to Three Different Strains of Athymic Nude Rats: Electrophysiological and Immunohistochemical Studies of Intraocular Grafts

Interest in the use of neural tissue transplantation for the study of CNS development and maturation and the potential use of this technique for the treatment of certain degenerative CNS disorders has led to our use of transplantation of neural tissue across species lines. Prior to extensive transplantation studies using athymic rats as recipients, we wished to evaluate the currently available strains of athymic rat for their suitability as host animals for xenografts of neural tissue. Fetal cerebellar and cerebral cortex tissue from rabbit brain of gestational age 20-25 days was dissected and transplanted to the anterior chamber of the eye of Harlan Wisconsin, Fisher 344 Jnu, or NCI-Harlan athymic nude rat strains. The brain tissue grafts were allowed to mature for 3 mo during which time the size and vascularity of each graft was monitored through the cornea of anesthetized hosts. In each group all of the transplants survived and grew to varying extents in the anterior chamber of the eye. Following the growth study in vivo extracellular recording of single neuronal activity was performed. Spontaneous neural activity was found in most transplants in all three groups with no difference in the viability or discharge rates of neurons between the groups. Illumination of the ipsilateral eye increased the firing rate of neurons in all three groups, suggesting excitatory cholinergic innervation of the grafted neurons from the host parasympathetic iris ground plexus. Antibodies directed against neurofilament protein, glial fibrillary acidic protein, synapsin, and tyrosine hydroxylase were used to characterize the transplants immunocytochemically and revealed no differences between the grafts in the three groups of recipients. All transplants contained significant numbers of glial and neuronal elements with the distribution resembling that in adult brain tissue. Some of the transplants contained a sparse innervation of tyrosine hydroxylase–positive fibers from the sympathetic plexus of the host iris. Furthermore, synapsin-immunoreactivity suggested that synaptogenesis had taken place within the grafts. Histological examination of the grafts revealed that 67% of the grafts had been infiltrated, to varying extents, by lymphocytes which led to areas of cell lysis and necrosis. All host animals had populations of T-cell receptor positive cells, most of which also expressed the T-cell surface antigens CD4 and CD8. However, no transplants were overtly rejected over the 15 wk period of study. Our investigation demonstrates that all of the athymic strains used in this study are able to mount an immune response against grafted fetal tissue, despite the absence of rejection, and that none of these strains is superior to the others with respect to suitability as a host for the long-term study of fetal CNS xenografts in oculo.

pRotective vEntilation with veno-venouS lung assisT in respiratory failure: A protocol for a multicentre randomised controlled trial of extracorporeal carbon dioxide removal in patients with acute hypoxaemic respiratory failure

One of the few interventions to demonstrate improved outcomes for acute hypoxaemic respiratory failure is reducing tidal volumes when using mechanical ventilation, often termed lung protective ventilation. Veno-venous extracorporeal carbon dioxide removal (vv-ECCO₂R) can facilitate reducing tidal volumes. pRotective vEntilation with veno-venouS lung assisT (REST) is a randomised, allocation concealed, controlled, open, multicentre pragmatic trial to determine the clinical and cost-effectiveness of lower tidal volume mechanical ventilation facilitated by vv-ECCO₂R in patients with acute hypoxaemic respiratory failure. Patients requiring intubation and mechanical ventilation for acute hypoxaemic respiratory failure will be randomly allocated to receive either vv-ECCO₂R and lower tidal volume mechanical ventilation or standard care with stratification by recruitment centre. There is a need for a large randomised controlled trial to establish whether vv-ECCO₂R in acute hypoxaemic respiratory failure can allow the use of a more protective lung ventilation strategy and is associated with improved patient outcomes.

Interleukin-10 is differentially expressed in the small intestine and the colon experiencing chronic inflammation and ulcerative colitis induced by dextran sodium sulfate in young pigs

Intestinal inflammation induced with dextran sodium sulfate (DSS) is used to study acute or chronic ulcerative colitis in animal models. Decreased gut tissue anti-inflammatory cytokine IL-10 concentration and mRNA abundance are associated with the development of chronic bowel inflammation. Twelve piglets of 3 days old were fitted with an intragastric catheter and randomly allocated into control and DSS groups by administrating either sterile saline or 1.25 g of DSS/kg body weight (BW) in saline per day, respectively, for 10 days. Growth rate and food conversion efficiency were reduced (p<0.05) in the DSS piglets compared with the control group. Quantitative histopathological grading of inflammation in the jejunum and colon collectively showed that the DSS treatment resulted in 12 fold greater (p<0.05) inflammation severity scoring in the colon than in the jejunum, indicative of chronic ulcerative colitis in the colon. Upper gut permeability endpoint was 27.4 fold higher (p<0.05) in the DSS group compared with the control group. The DSS group had higher concentrations and mRNA abundances (p<0.05) of TNF-alpha and IL-6 in the jejunal and colonic tissues compared with the control group. Colonic concentration and mRNA abundance of IL-10 were reduced (p<0.05), however, jejunal IL-10 mRNA abundance was increased (p<0.05) in the DSS group compared with the control group. In conclusion, administration of DSS at 1.25 g/kg BW for 10 days respectively induced acute inflammation in the jejunum and chronic inflammation and ulcerative colitis in the colon with substantially decreased colonic concentration and mRNA abundance of IL-10 in the young pigs, mimicking the IL-10 expression pattern in humans Associated with chronic bowel inflammation.

Effects of gelatine and medium molecular weight starch as priming fluid in cardiopulmonary bypass - a randomised controlled trial

Perioperative volume replacement after cardiopulmonary bypass is complicated by post-bypass systemic inflammatory process. The aim of this study was to assess the effects of using two different colloid solutions as priming fluids in cardiopulmonary bypass. The study's primary end point was to measure the amount of fluid replacement needed during and post-cardiopulmonary bypass; blood loss, change in blood profile and intraocular pressure were secondary end points, used as measures of plasma oncotic pressures. Patients undergoing coronary artery bypass grafting were recruited. Both patients and surgeons were blinded to receive either Gelofusine® or Voluven® as priming fluids. At fixed intervals during cardiopulmonary bypass, the patients had their intraocular pressures measured. Intra and postoperative fluid replacement was in the form of 4.5% human albumin and the amount was recorded for each subject. The result did not show any significant differences in the amount of fluid needed to be replaced, in blood loss or in blood profile between the two groups. However, it showed an increase in intraocular pressure in both groups once cardiopulmonary bypass commenced. The average intraocular pressure was higher in the Gelofusine ® group compared to the Voluven® group. The significant increase in intraocular pressure measurements in the Gelofusine® group compared to the Voluven® group support the hypothesis that Voluven maintains the plasma oncotic pressure better and reduces fluid shift. Perfusion (2007) 22, 57—62.

Child oral health in migrant families: A cross-sectional study of caries in 1-4 year old children from migrant backgrounds residing in Melbourne, Australia

Early Childhood Caries (ECC) is the most common, preventable disease of childhood. It can affect children's health and wellbeing and children from migrant families may be at greater risk of developing ECC.

OBJECTIVE

To describe ECC in children from migrant families, and explore possible influences.

BASIC RESEARCH DESIGN

Cross-sectional analysis of caries data collected as baseline data for an oral health promotion study.

PARTICIPANTS

The analysis sample included 630 1-4 year-old children clustered within 481 Iraqi, Lebanese and Pakistani families in Melbourne, Australia.

METHOD

Child participants received a community-based visual dental examination. Parents completed a self-administered questionnaire on demographics, ethnicity, and oral health knowledge, behaviour and attitudes.

MAIN OUTCOME MEASURE

Child caries experience. Bivariate associations between oral health behaviours and ethnicity were tested for significance using chi-square. Multivariate logistic regression analyses were performed to identify associations with ECC, adjusting for demographic variables and accounting for clustering by family.

RESULTS

Overall, 34% of children in the sample experienced caries (both non-cavitated and cavitated). For all caries lesions, parent' length of residence in Australia, consumption of sweet drinks and parental education remained as independent predictors of child caries experience. Adding sugar to drinks was an additional risk factor for cavitation. Ethnicity was associated with some individual oral health behaviours suggesting cultural influences on health, however the relationship was not independent of other predictors.

CONCLUSION

Culturally competent oral health promotion interventions should aim to support migrant families with young children, and focus on reducing sweet drink consumption.

Impact of insulin initiation on glycaemic variability and glucose profiles in a primary healthcare Type 2 diabetes cohort: analysis of continuous glucose monitoring data from the INITIATION study

AIM

To use continuous glucose monitoring to examine the effects of insulin initiation with glargine, with or without glulisine, on glycaemic variability and glycaemia in a cohort of people with Type 2 diabetes receiving maximum oral hypoglycaemic agents in primary healthcare.

METHODS

We conducted a post hoc analysis of continuous glucose monitoring data from 89 participants at baseline and at 24 weeks after insulin commencement. Indicators of glycaemic variability (standard deviation, J-index and mean amplitude of glycaemic excursion) and glycaemia (HbA1c , mean glucose, area under the glucose-time curve) were assessed. Multi-level regression analysis was used to identify the predictors of change.

RESULTS

Complete glycaemic variability data were available for 78 participants. Of these participants, 41% were women, their mean (sd) age was 59.2 (10.4) years, the median (interquartile range) diabetes duration was 10.4 (6.5, 13.3) years and the median (interquartile range) baseline HbA1c was 82.5 (71.6, 96.7) mmol/mol [9.7 (8.7, 11.0)%]. At baseline, BMI correlated negatively with standard deviation (r = -0.30) and mean amplitude of glycaemic excursion (r = -0.26), but not with J-index; HbA1c correlated with J-index (r = 0.61) but not with mean amplitude of glycaemic excursion and standard deviation. After insulin initiation the mean (sd) glucose level decreased [from 12.0 (3.0) to 8.5 (1.6) mmol/l; P < 0.001], as did the median (interquartile range) J-index [from 66.9 (47.7, 95.1) to 36.9 (27.6, 49.8) mmol/l; P < 0.001]. Baseline HbA1c correlated with a greater J-index reduction (r = -0.45; P < 0.001). The mean amplitude of glycaemic excursion and standard deviation values were unchanged. The baseline temporal profile, showing elevated postprandial morning glucose levels, was unchanged after insulin initiation, despite an overall reduction in glycaemia.

CONCLUSION

Insulin initiation reduced hyperglycaemia but did not alter glycaemic variability in adults with Type 2 diabetes receiving maximum oral hypoglycaemic agents. The most significant postprandial excursions were seen in the morning, which identifies prebreakfast as the most effective target for short-acting insulin therapy.

Standing sedation with medetomidine and butorphanol in captive African elephants (Loxodonta africana)

Doses for standing sedation allowing for various procedures in otherwise inaccessible, untrained captive African elephant bulls are presented. Thirty-three standing sedations were performed in 12 males aged 8-30 years (one to four sedations per animal). Each bull received a combination of 0.009 ± 0.002 mg/kg medetomidine and 0.03 ± 0.007 mg/kg butorphanol. Full sedation was reached on average 25.5 min after injection. The addition of hyaluronidase (1000-2000 IU) significantly reduced time to full sedation to 16.5 min (paired t test, P = 0.024). Reversal was induced with intramuscular atipamezole 0.008 (±0.002) and naltrexone 0.035 (±0.015) mg/kg. Recovery took on average 7 min (3-18 min). The medetomidine/butorphanol combination provided safe standing sedation for smaller procedures.

New Antarctic Gravity Anomaly Grid for Enhanced Geodetic and Geophysical Studies in Antarctica

Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km², which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated levelling of the different gravity datasets with respect to an Earth Gravity Model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth Gravity Models to be derived and represent a major step forward towards solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica.