Low baseline ribosome-related gene expression and resistance training-induced declines in ribosome-related gene expression are associated with skeletal muscle hypertrophy in young men and women

Ribosomes are essential cellular machinery for protein synthesis. It is hypothesised that ribosome content supports muscle growth and that individuals with more ribosomes have greater increases in muscle size following resistance training (RT). Aerobic conditioning (AC) also elicits distinct physiological adaptations; however, no measures of ribosome content following AC have been conducted. We used ribosome-related gene expression as a proxy measure for ribosome content and hypothesised that AC and RT would increase ribosome-related gene expression. Fourteen young men and women performed 6 weeks of single-legged AC followed by 10 weeks of double-legged RT. Muscle biopsies were taken following AC and following RT in the aerobically conditioned (AC+RT) and unconditioned (RT) legs. No differences in regulatory genes (Ubf, Cyclin D1, Tif-1a and Polr-1b) involved in ribosomal biogenesis or ribosomal RNA (45S, 5.8S, 18S and 28S rRNAs) expression were observed following AC and RT, except for c-Myc (RT > AC+RT) and 5S rRNA (RT < AC+RT at pre-RT) with 18S external transcribed spacer and 5.8S internal transcribed spacer expression decreasing from pre-RT to post-RT in the RT leg only. When divided for change in leg-lean soft tissue mass (ΔLLSTM) following RT, legs with the greatest ΔLLSTM had lower expression in 11/13 measured ribosome-related genes before RT and decreased expression in 9/13 genes following RT. These results indicate that AC and RT did not increase ribosome-related gene expression. Contrary to previous research, the greatest increase in muscle mass was associated with lower changes in ribosome-related gene expression over the course of the 10-week training programme. This may point to the importance of translational efficiency rather than translational capacity (i.e. ribosome content) in mediating long-term exercise-induced adaptations in skeletal muscle.

Sex-Specific Effect of CARM1 in Skeletal Muscle Adaptations to Exercise

PURPOSE

The purpose of this study was to determine how the intersection of coactivator-associated arginine methyltransferase 1 (CARM1) and biological sex affects skeletal muscle adaptations to chronic physical activity.

METHODS

Twelve-week-old female (F) and male (M) wild-type (WT) and CARM1 skeletal muscle-specific knockout (mKO) mice were randomly assigned to sedentary (SED) or voluntary wheel running (VWR) experimental groups. For 8 wk, the animals in the VWR cohort had volitional access to running wheels. Subsequently, we performed whole-body functional tests, and 48 h later muscles were harvested for molecular analysis. Western blotting, enzyme activity assays, as well as confocal and transmission electron microscopy were used to examine skeletal muscle biology.

RESULTS

Our data reveal a sex-dependent reduction in VWR volume caused by muscle-specific ablation of CARM1, as F CARM1 mKO mice performed less chronic, volitional exercise than their WT counterparts. Regardless of VWR output, exercise-induced adaptations in physiological function were similar between experimental groups. A broad panel of protein arginine methyltransferase (PRMT) biology measurements, including markers of arginine methyltransferase expression and activity, were unaffected by VWR, except for CARM1 and PRMT7 protein levels, which decreased and increased with VWR, respectively. Changes in myofiber morphology and mitochondrial protein content showed similar trends among animals. However, a closer examination of transmission electron microscopy images revealed contrasting responses to VWR in CARM1 mKO mice compared with WT littermates, particularly in mitochondrial size and fractional area.

CONCLUSIONS

The present findings demonstrate that CARM1 mKO reduces daily running volume in F mice, as well as exercise-evoked skeletal muscle mitochondrial plasticity, which indicates that this enzyme plays an essential role in sex-dependent differences in exercise performance and mitochondrial health.

CARM1 drives mitophagy and autophagy flux during fasting-induced skeletal muscle atrophy

CARM1 (coactivator associated arginine methyltransferase 1) has recently emerged as a powerful regulator of skeletal muscle biology. However, the molecular mechanisms by which the methyltransferase remodels muscle remain to be fully understood. In this study, carm1 skeletal muscle-specific knockout (mKO) mice exhibited lower muscle mass with dysregulated macroautophagic/autophagic and atrophic signaling, including depressed AMP-activated protein kinase (AMPK) site-specific phosphorylation of ULK1 (unc-51 like autophagy activating kinase 1; Ser555) and FOXO3 (forkhead box O3; Ser588), as well as MTOR (mechanistic target of rapamycin kinase)-induced inhibition of ULK1 (Ser757), along with AKT/protein kinase B site-specific suppression of FOXO1 (Ser256) and FOXO3 (Ser253). In addition to lower mitophagy and autophagy flux in skeletal muscle, carm1 mKO led to increased mitochondrial PRKN/parkin accumulation, which suggests that CARM1 is required for basal mitochondrial turnover and autophagic clearance. carm1 deletion also elicited PPARGC1A (PPARG coactivator 1 alpha) activity and a slower, more oxidative muscle phenotype. As such, these carm1 mKO-evoked adaptations disrupted mitophagy and autophagy induction during food deprivation and collectively served to mitigate fasting-induced muscle atrophy. Furthermore, at the threshold of muscle atrophy during food deprivation experiments in humans, skeletal muscle CARM1 activity decreased similarly to our observations in mice, and was accompanied by site-specific activation of ULK1 (Ser757), highlighting the translational impact of the methyltransferase in human skeletal muscle. Taken together, our results indicate that CARM1 governs mitophagic, autophagic, and atrophic processes fundamental to the maintenance and remodeling of muscle mass. Targeting the enzyme may provide new therapeutic approaches for mitigating skeletal muscle atrophy.

Impact of short-term, pharmacological CARM1 inhibition on skeletal muscle mass, function, and atrophy in mice

Coactivator-associated arginine methyltransferase 1 (CARM1) catalyzes the methylation of arginine residues on target proteins critical for health and disease. The purpose of this study was to characterize the effects of short-term, pharmacological CARM1 inhibition on skeletal muscle size, function, and atrophy. Adult mice (n = 10 or 11/sex) were treated with either a CARM1 inhibitor (150 mg/kg EZM2302; EZM) or vehicle (Veh) via oral gavage for 11-13 days and muscle mass, function, and exercise capacity were assessed. In addition, we investigated the effect of CARM1 suppression on unilateral hindlimb denervation (DEN)-induced muscle atrophy (n = 8/sex). We report that CARM1 inhibition caused significant reductions in the asymmetric dimethylation of known CARM1 substrates but no change in CARM1 protein or mRNA content in skeletal muscle. Reduced CARM1 activity did not affect body or muscle mass, however, we observed a decrease in exercise capacity and muscular endurance in male mice. CARM1 methyltransferase activity increased in the muscle of Veh-treated mice following 7 days of DEN, and this response was blunted in EZM-dosed mice. Skeletal muscle mass and myofiber cross-sectional area were significantly reduced in DEN compared with contralateral, non-DEN limbs to a similar degree in both treatment groups. Furthermore, skeletal muscle atrophy and autophagy gene expression programs were elevated in response to DEN independent of CARM1 suppression. Collectively, these results suggest that short-term, pharmacological CARM1 inhibition in adult animals affects muscle performance in a sex-specific manner but does not impact the maintenance and remodeling of skeletal muscle mass during conditions of neurogenic muscle atrophy.NEW & NOTEWORTHY Short-term pharmacological inhibition of coactivator-associated arginine methyltransferase 1 (CARM1) was effective at significantly reducing CARM1 methyltransferase function in skeletal muscle. CARM1 inhibition did not impact muscle mass, but exercise capacity was impaired, particularly in male mice, whereas morphological and molecular signatures of denervation-induced muscle atrophy were largely maintained in animals administered the inhibitor. Altogether, the role of CARM1 in neuromuscular biology remains complex and requires further investigation of its therapeutic potential in muscle-wasting conditions.

Fortetropin supplementation prevents the rise in circulating myostatin but not disuse-induced muscle atrophy in young men with limb immobilization: A randomized controlled trial

Supplementation with Fortetropin® (FOR), a naturally occurring component from fertilized egg yolks, reduces circulating myostatin concentration. We hypothesized that FOR would mitigate muscle atrophy during immobilization. We examined the effect of FOR supplementation on muscle size and strength during 2-wk of single-leg immobilization and recovery. Twenty-four healthy young men (22 ± 2 yrs; BMI = 24.3 ± 2.9 kg/m2) were randomly allocated to either a Fortetropin® supplement (FOR-SUPP, n = 12) group consuming 19.8 g/d of FOR or placebo (PLA-SUPP, n = 12) group consuming energy- and macronutrient-matched cheese powder for 6-wk. The 6-wk period consisted of 2-wk run-in, 2-wk single-leg immobilization, and 2-wk recovery phase returning to habitual physical activities. Ultrasonography, dual-energy X-ray absorptiometry, muscle biopsies and isometric peak torque assessments were performed prior to and following each phase (days 1, 14, 28, and 42) to measure vastus lateralis and muscle fiber cross-section area (CSA), leg lean mass (LM), and muscular strength. Blood samples were taken on days 1 and 42 for measurement of plasma myostatin concentration, which increased in PLA-SUPP (4221 ± 541 pg/mL to 6721 ± 864 pg/mL, P = 0.013) but not in FOR-SUPP (5487 ± 489 pg/mL to 5383 ± 781 pg/mL, P = 0.900). After the immobilization phase, vastus lateralis CSA, LM, and isometric peak torque were decreased by 7.9 ± 1.7% (P < 0.001), -1.6 ± 0.6% (P = 0.037), and -18.7 ± 2.7% (P < 0.001) respectively, with no difference between groups. The decreased peak torque was recovered after 2-wk of normal activity (vs. day 1, P = 0.129); however, CSA and LM were not recovered (vs. day 1, P < 0.001 and P = 0.003, respectively), with no differences between groups. Supplementation with FOR prevented the rise in circulating myostatin but not disuse-induced muscle atrophy in young men after 2-wk of single-leg immobilization.

Acute, next-generation AMPK activation initiates a disease-resistant gene expression program in dystrophic skeletal muscle

Duchenne muscular dystrophy (DMD) is a life-limiting neuromuscular disorder characterized by muscle weakness and wasting. Previous proof-of-concept studies demonstrate that the dystrophic phenotype can be mitigated with the pharmacological stimulation of AMP-activated protein kinase (AMPK). However, first-generation AMPK activators have failed to translate from bench to bedside due to either their lack of potency or toxic, off-target effects. The identification of safe and efficacious molecules that stimulate AMPK in dystrophic muscle is of particular importance as it may broaden the therapeutic landscape for DMD patients regardless of their specific dystrophin mutation. Here, we demonstrate that a single dose of the next generation, orally-bioactive AMPK agonist MK-8722 (MK) to mdx mice evoked skeletal muscle AMPK and extensive downstream stimulation within 12 h post-treatment. Specifically, MK elicited a gene expression profile indicative of a more disease-resistant slow, oxidative phenotype including increased peroxisome proliferator-activated receptor ɣ coactivator-1⍺ activity and utrophin levels. In addition, we observed augmented autophagy signaling downstream of AMPK, as well as elevations in critical autophagic genes such as Map1lc3 and Sqstm1 subsequent to the myonuclear accumulation of the master regulator of the autophagy gene program, transcription factor EB. Lastly, we show that pharmacological AMPK stimulation normalizes the expression of myogenic regulatory factors and amends activated muscle stem cell content in mdx muscle. Our results indicate that AMPK activation via MK enhances disease-mitigating mechanisms in dystrophic muscle and prefaces further investigation on the chronic effects of novel small molecule AMPK agonists.

AMPK is mitochondrial medicine for neuromuscular disorders

Duchenne muscular dystrophy (DMD), myotonic dystrophy type 1 (DM1), and spinal muscular atrophy (SMA) are the most prevalent neuromuscular disorders (NMDs) in children and adults. Central to a healthy neuromuscular system are the processes that govern mitochondrial turnover and dynamics, which are regulated by AMP-activated protein kinase (AMPK). Here, we survey mitochondrial stresses that are common between, as well as unique to, DMD, DM1, and SMA, and which may serve as potential therapeutic targets to mitigate neuromuscular disease. We also highlight recent advances that leverage a mutation-agnostic strategy featuring physiological or pharmacological AMPK activation to enhance mitochondrial health in these conditions, as well as identify outstanding questions and opportunities for future pursuit.

A single dose of exercise stimulates skeletal muscle mitochondrial plasticity in myotonic dystrophy type 1

AIM

Myotonic dystrophy type 1 (DM1) is the second most common muscular dystrophy after Duchenne and is the most prevalent muscular dystrophy in adults. DM1 patients that participate in aerobic exercise training experience several physiological benefits concomitant with improved muscle mitochondrial function without alterations in typical DM1-specific disease mechanisms, which suggests that correcting organelle health is key to ameliorate the DM1 pathology. However, our understanding of the molecular mechanisms of mitochondrial turnover and dynamics in DM1 skeletal muscle is lacking.

METHODS

Skeletal muscle tissue was sampled from healthy and DM1 mice under sedentary conditions and at several recovery time points following an exhaustive treadmill run.

RESULTS

We demonstrate that DM1 patients exhibit an imbalance in the transcriptional apparatus for mitochondrial turnover and dynamics in skeletal muscle. Additionally, DM1 mice displayed elevated expression of autophagy and mitophagy regulators. A single dose of exercise successfully enhanced canonical exercise molecular pathways and skeletal muscle mitochondrial biogenesis despite failing to alter the cellular pathology in DM1 mice. However, treadmill running stimulated coordinated organelle fusion and fission signaling, as well as improved alternative splicing of Optic atrophy 1. Exercise also evoked autophagy and mitophagy pathways in DM1 skeletal muscle resulting in the normalized expression of autophagy- and lysosome-related machinery responsible for the clearance of dysfunctional organelles.

CONCLUSION

Collectively, our data indicate that mitochondrial dynamics and turnover processes in DM1 skeletal muscle are initiated with a single dose of exercise, which may underlie the adaptive benefits previously documented in DM1 mice and patients.

The CARM1 transcriptome and arginine methylproteome mediate skeletal muscle integrative biology

OBJECTIVE

Coactivator-associated arginine methyltransferase 1 (CARM1) catalyzes the methylation of arginine residues on target proteins to regulate critical processes in health and disease. A mechanistic understanding of the role(s) of CARM1 in skeletal muscle biology is only gradually emerging. The purpose of this study was to elucidate the function of CARM1 in regulating the maintenance and plasticity of skeletal muscle.

METHODS

We used transcriptomic, methylproteomic, molecular, functional, and integrative physiological approaches to determine the specific impact of CARM1 in muscle homeostasis.

RESULTS

Our data defines the occurrence of arginine methylation in skeletal muscle and demonstrates that this mark occurs on par with phosphorylation and ubiquitination. CARM1 skeletal muscle-specific knockout (mKO) mice displayed altered transcriptomic and arginine methylproteomic signatures with molecular and functional outcomes confirming remodeled skeletal muscle contractile and neuromuscular junction characteristics, which presaged decreased exercise tolerance. Moreover, CARM1 regulates AMPK-PGC-1α signalling during acute conditions of activity-induced muscle plasticity.

CONCLUSIONS

This study uncovers the broad impact of CARM1 in the maintenance and remodelling of skeletal muscle biology.

Aerobic exercise elicits clinical adaptations in myotonic dystrophy type 1 patients independent of pathophysiological changes

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a complex life-limiting neuromuscular disorder characterized by severe skeletal muscle atrophy, weakness, and cardio-respiratory defects. Exercised DM1 mice exhibit numerous physiological benefits that are underpinned by reduced CUG foci and improved alternative splicing. However, the efficacy of physical activity in patients is unknown.

METHODS

Eleven genetically diagnosed DM1 patients were recruited to examine the extent to which 12-weeks of cycling can recuperate clinical, and physiological metrics. Furthermore, we studied the underlying molecular mechanisms through which exercise elicits benefits in skeletal muscle of DM1 patients.

RESULTS

DM1 was associated with impaired muscle function, fitness, and lung capacity. Cycling evoked several clinical, physical, and metabolic advantages in DM1 patients. We highlight that exercise-induced molecular and cellular alterations in patients do not conform with previously published data in murine models and propose a significant role of mitochondrial function in DM1 pathology. Lastly, we discovered a subset of small nucleolar RNAs (snoRNAs) that correlated to indicators of disease severity.

CONCLUSION

With no available cures, our data supports the efficacy of exercise as a primary intervention to partially mitigate the clinical progression of DM1. Additionally, we provide evidence for the involvement of snoRNAs and other noncoding RNAs in DM1 pathophysiology.

TRIAL REGISTRATION

This trial was approved by the HiREB committee (#7901) and registered under ClinicalTrials.gov (NCT04187482).

FUNDING

This work was primarily supported by Neil and Leanne Petroff. This study was also supported by a Canadian Institutes of Health Research Foundation Grant to MAT (#143325).

Effect of the use of earplugs and eye masks on the quality of sleep after major abdominal surgery: a randomised controlled trial

Significant sleep disturbance can occur following major abdominal surgery. We aimed to evaluate the effectiveness of earplugs and eye masks in improving sleep quality and patient satisfaction, reducing nursing demands and in the incidence of delirium in patients after major abdominal surgery. We conducted a randomised controlled trial in 100 patients undergoing major abdominal surgery. We randomly allocated participants to sleep with or without earplugs and eye masks on postoperative days 1-3. The primary outcome measure was sleep quality as measured by the Richards-Campbell Sleep Questionnaire. Secondary outcomes were patient satisfaction, frequency of nursing demand and incidence of delirium measured by the Neelon and Champagne Confusion Scale. Median (IQR [range]) sleep scores were 64 (38-74 [0-100] and 60 (44-82 [18-100]) for the control and intervention groups, respectively (p = 0.310). Age and Pittsburgh Sleep Quality Index scores were found to be significant factors affecting sleep quality. There were no differences in patient satisfaction, reduction in frequency of nursing demands or incidence of delirium on postoperative days 1-3 after major abdominal surgery. The compliance rate in the intervention group was 60-65%. This study has demonstrated that the use of earplugs and eye masks did not contribute to improvements in sleep quality. Of note, sleep quality was moderate, with higher age and worse baseline sleep quality contributing to worse sleep scores. More studies are needed to investigate interventions to improve sleep quality after major abdominal surgery.

Recent insights into neuromuscular junction biology in Duchenne muscular dystrophy: Impacts, challenges, and opportunities

Duchenne muscular dystrophy (DMD) is the most common and relentless form of muscular dystrophy. The pleiotropic effects of dystrophin deficiency include remarkable impacts on neuromuscular junction (NMJ) structure and function. Some of these alterations contribute to the severe muscle wasting and weakness that distinguish DMD, while others attempt to compensate for them. Experimental approaches that correct NMJ biology in pre-clinical models of DMD attenuate disease progression and improve functional outcomes, which suggests that targeting the NMJ may be an effective therapeutic strategy for DMD patients. The objectives of this review are to 1) survey the distinctions in NMJ structure, function, and gene expression in the dystrophic context as compared to the healthy condition, and 2) summarize the efforts, opportunities and challenges to correct NMJ biology in DMD. This information will expand our basic understanding of neuromuscular biology and may be useful for designing novel NMJ-targeted drug or behavioural strategies to mitigate the dystrophic pathology and other disorders of the neuromuscular system.

Tunability of Acoustic and Mechanical Behaviors in Breast Tissue Mimicking Materials

In radiology practices, the ultrasound-guided breast biopsy is among the most commonly performed minimally invasive procedures. However, many radiology residents in their graduate residencies are found with little or no hands-on experience with ultrasound-guided breast procedures. To enhance safety, the problem can be solved by the use of anthropomorphic training phantoms which can provide the resident with realistic ultrasound imaging and needle insertion haptic feedback. Stiffness and acoustic properties of breast tissues vary between different people. The training breast phantom should be able to possess different acoustic and mechanical properties which conform the inconsistencies found in real tissues among people. Therefore, this paper investigates the tunability of acoustic and mechanical behaviors in breast tissue mimicking materials (TMMs). Experiments of central composite design (CCD) with a center point, four corner points, and an additional four axis points were used to fit the non-linear regression model of the speed of sound. The same design of experiment approach was then used to fit the second-order response surface of the attenuation coefficient. Suitable series of tissue mimicking materials for the glandular tissue and malignant lesion were suggested. Latin hypercube design method was conducted to evaluate the main factors that affected the mechanical property (Young's modulus) of tissue mimicking materials. The results showed that the recipe of tissue mimicking materials could be customized to possess different acoustic and mechanical properties which conform the inconsistencies found in real breast tissues.

An accidental laboratory exposure to Brucella melitensis: the prospective post-exposure management and a detailed investigation into the nature of the exposure

Our aim was to prospectively manage 22 Brucella-exposed individuals and identify the lapses in laboratory practices that lead to the exposure. The exposed individuals were risk-stratified, assessed for post-exposure prophylaxis (PEP), counselled to self-monitor symptoms and followed-up with three serology tests. Staff laboratory practices were recorded. Ten out of 13 high-risk individuals received PEP within 48 h of exposure. Compliance with PEP and serology monitoring was 90 and 96 %, respectively. No brucellosis cases were documented. A single handler manipulated the Brucella isolate on the open bench. Movement of the isolate was tracked in detail, highlighting various points of laboratory non-conformance. Early PEP intervention is effective in preventing acquired brucellosis. Our pragmatic post-exposure management achieved high PEP and serology compliance. We experience first-hand how regular staff engagement motivated PEP adherence and interval blood sampling attendance. The enforcement of practical strategies and safety practices was also implemented without compromising our laboratory processing times.

Mechanisms of exercise-induced survival motor neuron expression in the skeletal muscle of spinal muscular atrophy-like mice

Key points

Spinal muscular atrophy (SMA) is a health‐ and life‐limiting neuromuscular disorder caused by a deficiency in survival motor neuron (SMN) protein.

While historically considered a motor neuron disease, current understanding of SMA emphasizes its systemic nature, which requires addressing affected peripheral tissues such as skeletal muscle in particular.

Chronic physical activity is beneficial for SMA patients, but the cellular and molecular mechanisms of exercise biology are largely undefined in SMA.

After a single bout of exercise, canonical responses such as skeletal muscle AMP‐activated protein kinase (AMPK), p38 mitogen‐activated protein kinase (p38) and peroxisome proliferator‐activated receptor γ coactivator 1α (PGC‐1α) activation were preserved in SMA‐like Smn^2B/− animals. Furthermore, molecules involved in SMN transcription were also altered following physical activity. Collectively, these changes were coincident with an increase in full‐length SMN transcription and corrective SMN pre‐mRNA splicing.

This study advances understanding of the exercise biology of SMA and highlights the AMPK–p38–PGC‐1α axis as a potential regulator of SMN expression in muscle.

Abstract

Chronic physical activity is safe and effective in spinal muscular atrophy (SMA) patients, but the underlying cellular events that drive physiological adaptations are undefined. We examined the effects of a single bout of exercise on molecular mechanisms associated with adaptive remodelling in the skeletal muscle of Smn^2B/− SMA‐like mice. Skeletal muscles were collected from healthy Smn^2B/+ mice and Smn^2B/− littermates at pre‐ (postnatal day (P) 9), early‐ (P13) and late‐ (P21) symptomatic stages to characterize SMA disease progression. Muscles were also collected from Smn^2B/− animals exercised to fatigue on a motorized treadmill. Intracellular signalling and gene expression were examined using western blotting, confocal immunofluorescence microscopy, real‐time quantitative PCR and endpoint PCR assays. Basal skeletal muscle AMP‐activated protein kinase (AMPK) and p38 mitogen‐activated protein kinase (p38) expression and activity were not affected by SMA‐like conditions. Canonical exercise responses such as AMPK, p38 and peroxisome proliferator‐activated receptor γ coactivator‐1α (PGC‐1α) activation were observed following a bout of exercise in Smn^2B/− animals. Furthermore, molecules involved in survival motor neuron (SMN) transcription, including protein kinase B (AKT) and extracellular signal‐regulated kinases (ERK)/ETS‐like gene 1 (ELK1), were altered following physical activity. Acute exercise was also able to mitigate aberrant proteolytic signalling in the skeletal muscle of Smn^2B/− mice. Collectively, these changes were coincident with an exercise‐evoked increase in full‐length SMN mRNA expression. This study advances our understanding of the exercise biology of SMA and highlights the AMPK–p38–PGC‐1α axis as a potential regulator of SMN expression alongside AKT and ERK/ELK1 signalling.

Spinal muscular atrophy (SMA) is a health‐ and life‐limiting neuromuscular disorder caused by a deficiency in survival motor neuron (SMN) protein.

While historically considered a motor neuron disease, current understanding of SMA emphasizes its systemic nature, which requires addressing affected peripheral tissues such as skeletal muscle in particular.

Chronic physical activity is beneficial for SMA patients, but the cellular and molecular mechanisms of exercise biology are largely undefined in SMA.

After a single bout of exercise, canonical responses such as skeletal muscle AMP‐activated protein kinase (AMPK), p38 mitogen‐activated protein kinase (p38) and peroxisome proliferator‐activated receptor γ coactivator 1α (PGC‐1α) activation were preserved in SMA‐like Smn^2B/− animals. Furthermore, molecules involved in SMN transcription were also altered following physical activity. Collectively, these changes were coincident with an increase in full‐length SMN transcription and corrective SMN pre‐mRNA splicing.

This study advances understanding of the exercise biology of SMA and highlights the AMPK–p38–PGC‐1α axis as a potential regulator of SMN expression in muscle.

Comparison of the AMBU® Laryngeal Mask and the LMA Classic in Anaesthetised, Spontaneously Breathing Patients

There may be a role for single-use laryngeal mask airways with concerns about inability to adequately sterilise laryngeal mask airways to eradicate prion proteins. A single-blinded prospective randomised controlled trial was conducted to compare the clinical performance of the single-use AMBU®LMA with the reuseable LMA Classic. There was no difference in time to insertion, successful insertion at first attempt, oropharyngeal leak pressure, haemodynamic response to insertion or complications of placement. The AMBU®LMA was easier to insert. There was a suggestion of reduced postoperative sore throat and pharyngeal trauma for the AMBU® LMA group. The AMBU®LMA is a viable alternative to the LMA Classic for airway management in spontaneously breathing patients.

Exercise biology of neuromuscular disorders

Neuromuscular disorders (NMDs) are chronic conditions that affect the neuromuscular system. Many NMDs currently have no cure; however, as more effective therapies become available for NMD patients, these individuals will exhibit improved health and/or prolonged lifespans. As a result, persons with NMDs will likely desire to engage in a more diverse variety of activities of daily living, including increased physical activity or exercise. Therefore, there is a need to increase our knowledge of the effects of acute exercise and chronic training on the neuromuscular system in NMD contexts. Here, we discuss the disease mechanisms and exercise biology of Duchenne muscular dystrophy (DMD), spinal muscular atrophy (SMA), and myotonic dystrophy type 1 (DM1), which are among the most prevalent NMDs in children and adults. Evidence from clinical and preclinical studies are reviewed, with emphasis on the functional outcomes of exercise, as well as on the putative cellular mechanisms that drive exercise-induced remodelling of the neuromuscular system. Continued investigation of the molecular mechanisms of exercise adaptation in DMD, SMA, and DM1 will assist in enhancing our understanding of the biology of these most prevalent NMDs. This information may also be useful for guiding the development of novel therapeutic targets for future pursuit.

The Role of AMPK in Neuromuscular Biology and Disease

AMP-activated protein kinase (AMPK) is a primary regulator of cellular metabolism. Recent studies have revealed that AMPK also mediates the maintenance and plasticity of α-motoneurons, the neuromuscular junction, and skeletal muscle. Furthermore, AMPK stimulation by either genetic, pharmacological, or physiological approaches elicits beneficial phenotypic remodeling in neuromuscular disorders (NMDs). Here, we review the role of AMPK as a governor of neuromuscular biology, and present evidence for AMPK as an effective molecular target for therapeutic pursuit in the context of the most prevalent NMDs, including Duchenne muscular dystrophy, spinal muscular atrophy, and myotonic dystrophy type 1. This information may be useful for engineering AMPK-targeted pharmacological- or lifestyle-based strategies to treat disorders of the neuromuscular system.

Nurse Performed Ultrasonography in Confirming the Position of Nasogastric Tube in the Emergency Department: A Prospective Single Group Diagnostic Test Study

Introduction

Emergency nurses often encounter patients with nasogastric tube (NGT) dislodgements who require reinsertion. Empirical evidence supporting the use of ultrasonography in verifying the position of NGT in local accident and emergency departments (AED) is scanty. There is also a lack of validation of nurse performed ultrasonography in Hong Kong. With the support from hospitals and medical personnel, a prospective, single group diagnostic test study was conducted to review the possibility of nurse performed ultrasonography in verifying the position of NGT in AED.

Methods

This study was conducted in the AED of three local hospitals. Investigators with specific ultrasound training performed ultrasonography scans to the subjects in addition to conventional pH test and “whoosh” test. Results were compared with chest or abdominal X-ray for evaluation of accuracies.

Results

This study confirmed a high sensitivity and specificity of nurse performed ultrasonography in confirming the position of NGT in the AED. The high positive predictive value and positive likelihood ratio supported the confirmation of NGT position by bedside ultrasound. The high specificities and minimal negative likelihood ratios of ultrasonography tests also suggested the application of bedside ultrasound in ruling out patients with misplaced NGTs.

Conclusions

Nurse performed ultrasonography allows immediate bedside confirmation of the position of NGT in the overcrowded AED. Considered the limitations of conventional methods, nurse performed ultrasonography can be incorporated into daily practice for providing extra evidence for the confirmation of NGT position.

Dynapenic obesity and the risk of incident Type 2 diabetes: the English Longitudinal Study of Ageing

AIM

Obesity is a well-established risk factor for developing Type 2 diabetes. Evidence suggests that sarcopenia, the age-related decline in muscle mass and strength, may exacerbate diabetes risk in obese individuals. The aim of this study was to determine the combined effect of obesity and low muscle strength, dynapenia, on the risk of incident Type 2 diabetes in older adults.

METHODS

Participants were 5953 (1670 obese) men and women from the English Longitudinal Study of Ageing without known Type 2 diabetes at baseline and for whom handgrip strength, biochemical and other clinical data were collected. A diagnosis of Type 2 diabetes was recorded from self-reported physician diagnosis over 6 years.

RESULTS

For each unit increase in grip strength, there was a reduction in diabetes risk (age-, sex- and BMI adjusted HR; 0.98; 95% CI 0.96-0.99). The risk of Type 2 diabetes was elevated in all obese participants, but was greatest in those with low handgrip strength (HR = 4.93, 95% CI 2.85, 8.53) compared with non-obese individuals with high handgrip strength. Eleven per cent of the sample met the threshold for weakness (handgrip strength: men < 26 kg; women < 16 kg) that was associated with elevated Type 2 diabetes risk in obese (HR = 3.57, 95% CI 2.04, 6.24) but not in non-obese (HR = 0.86, 95% CI, 0.44, 1.68) compared with normal/non-obese participants.

CONCLUSION

Dynapenic obesity, determined by high BMI and low handgrip strength, is associated with increased risk of incident Type 2 diabetes in older people.

Temporal bone squamous cell carcinoma - Penang experience

Temporal bone squamous cell carcinoma (TBSCC) is rare and poses difficulties in diagnosing, staging and management. We describe a case series with six patients who were diagnosed TBSCC, from January 2009 to June 2014, with median age of 62 years old. All patients presented with blood-stain discharge and external auditory canal mass, showing that these findings should highly alert the diagnosis of TBSCC. Three patients staged T3 and another three with T4 disease. High-resolution CT (HRCT) temporal findings were noted to be different from intraoperative findings and therefore we conclude that MRI should be done to look for middle ear involvement or other soft tissue invasion for more accurate staging. Lateral temporal bone resection (LTBR) and parotidectomy was done for four patients with or without neck dissection. Patients with positive margin, perineural invasion or parotid and glenoid involvement carry poorer prognosis and postoperative radiotherapy may improve the survival rate. One patient had successful tumor resection via piecemeal removal approach in contrast with the recommended en bloc resection shows that with negative margin achieved, piecemeal removal approach can be a good option for patients with T2-3 disease. In general, T4 tumor has dismal outcome regardless of surgery or radiotherapy given.

Bracing Scoliosis - State of the Art

Spinal bracing is indicated in moderate to severe curves during growth. Brace effectiveness in halting progression of adolescent idiopathic scolisosis has been shown in a Cochrane review and in a randomized controlled trial (RCT). The outcome of brace treatment is dependent on the extent of in-brace correction and compliance. We have reviewed the literature on bracing to determine the types of brace that offer the best in-brace correction.

MATERIALS AND METHODS

The literature has been searched for papers on bracing with documented in-brace corrections and long-term results .

RESULTS

The in-brace percentage of correction of asymmetric braces is generally higher than that of the symmetric braces. According to the literature found in our search, long-term corrections are possible when starting treatment early, at an immature stage and with asymmetric braces of recent standards.

CONCLUSIONS

Bracing today is supported by high quality evidence (Level I). Asymmetric braces have led to better corrections than that described for symmetric braces . An improvement of the average corrective effect has been described due to the latest CAD / CAM development. Long-term corrections are possible when starting brace treatment early, at an immature stage and with asymmetric braces of recent standards.

What Do Mothers know about Neonatal Jaundice? Knowledge, Attitude and Practice of Mothers in Malaysia

No abstract available.

Design and preliminary recruitment results of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP)

BACKGROUND

Screening for prostate cancer continues to generate controversy because of concerns about over-diagnosis and unnecessary treatment. We describe the rationale, design and recruitment of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP) trial, a UK-wide cluster randomised controlled trial investigating the effectiveness and cost-effectiveness of prostate-specific antigen (PSA) testing.

METHODS

Seven hundred and eighty-five general practitioner (GP) practices in England and Wales were randomised to a population-based PSA testing or standard care and then approached for consent to participate. In the intervention arm, men aged 50-69 years were invited to undergo PSA testing, and those diagnosed with localised prostate cancer were invited into a treatment trial. Control arm practices undertook standard UK management. All men were flagged with the Health and Social Care Information Centre for deaths and cancer registrations. The primary outcome is prostate cancer mortality at a median 10-year-follow-up.

RESULTS

Among randomised practices, 271 (68%) in the intervention arm (198,114 men) and 302 (78%) in the control arm (221,929 men) consented to participate, meeting pre-specified power requirements. There was little evidence of differences between trial arms in measured baseline characteristics of the consenting GP practices (or men within those practices).

CONCLUSIONS

The CAP trial successfully met its recruitment targets and will make an important contribution to international understanding of PSA-based prostate cancer screening.

A comparison between bitewing radiographs taken with rectangular and circular collimators in UK military dental practices: a retrospective study

OBJECTIVES

The aim of this study was to determine any increase in the incidence of cone cut errors that adversely affected diagnostic yield resulting in more retakes using rectangular collimation with film holders in bitewing radiography. Comparisons were also made with other positioning errors that occurred when bitewings were taken with circular collimation, with and without film holders.

METHODS

A preliminary questionnaire was used to determine the year that rectangular collimation was adopted by military dental practice. 3 time-framed subsets, each of 1000 bitewing radiographs, were identified: subset 1, films taken with circular collimators without film holders; subset 2, films taken with circular collimators with film holders; and subset 3, films taken with rectangular collimators with film holders. Each subset was assessed for positioning errors of cone cut, horizontal overlap, vertical distortion and film centring. The χ(2) test was used to test significant differences amongst the three subsets.

RESULTS

The use of film holders with circular collimation significantly reduced the incidence of cone cut errors from 21.7% to 3.3%. There was an increase in the incidence of cone cut errors from 3.3% to 20.9% when rectangular collimation was used, but the actual number considered "rejects" was very small, only 0.1% (1 in 1000 films) in subset 2 and 0.3% (3 of 1000 films) in subset 3, when assessed for diagnostic yield.

CONCLUSIONS

This study provides evidence that rectangular collimation did not significantly affect the diagnostic yield of bitewing radiographs despite the presence of cone cut. Therefore, all practitioners should adopt rectangular collimation.

UGT1A1 haplotype mutation among Asians in Singapore

BACKGROUND

The uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) enzyme is responsible for conjugation of the bilirubin in the liver as well as for drug metabolism. Some of the polymorphisms have been associated with an increased risk of neonatal hyperbilirubinemia which may explain the increased incidence of jaundice in an Asian population as well as exaggerated irinotecan-induced leukopenia.

OBJECTIVE

The local Asian incidence of hypomorphic haplotypes, defined as gene mutations known to have a reduced function, has not been described. Clinical correlation between the mutations and the need for phototherapy for hyperbilirubinemia was carried out.

METHODS

A cohort of 241 consecutive term infants delivered in the National University Hospital, Singapore, was recruited with parental consent. Cord blood was collected, and the promoter and coding regions of the UGT1A1 gene were sequenced.

RESULTS

Six known haplotypes and 2 novel haplotypes were identified: 1 wild type, 5 with reduced function, while the 2 novel ones were predicted to have decreased function. The frequency of these hypomorphic haplotypes was high. Among the 241 infants screened, 35% had 1 hypomorphic haplotype and 12% had 2 hypomorphic haplotypes. The frequency was also different among ethnic groups, with 48% Chinese, 64% Indian and 31% Malay infants having at least 1 hypomorphic haplotype (chi(2) test, p < 0.05). There was a trend seen between the number of G71R mutations and the need for phototherapy (chi2 test for trend, p < 0.05).

CONCLUSIONS

The local Asian incidence of hypomorphic haplotypes was high and there was a trend between the number of G71R mutations and the need for phototherapy. The G71R mutation may account for the increased incidence of neonatal jaundice seen in Asian populations.

Use of Block Copolymers of Poly(Ortho Esters) and Poly (Ethylene Glycol) Micellar Carriers as Potential Tumour Targeting Systems

Amphiphilic AB and ABA block copolymers have been prepared from poly (ortho esters) and poly (ethylene glycol). Such block copolymers readily form micellar dispersions in water, or buffers. The CMC is in the range of 3 x 10(-4)-5 x 10(-4) g/l which is a value low enough to assure retention of micelle integrity upon intravenous injection. The size, as determined by dynamic light scattering was in the 40-70 nm range. The micelles can be stored in lyophilized form for at lest 8 months and easily reconstituted to the original properties. The micelles are stable in PBS at pH 7.4 and 37 degrees C for 3 days and in a citrate buffer at pH 5.5 and 37 degrees C for 2 h. Stability in the presence of bovine serum albumin depends on the structure of the block copolymer and especially the length of the POE block.

Detection of plasmid-mediated AmpC in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis

AIMS

This study investigated the prevalence of plasmid-mediated AmpC production in selected clinical isolates of Escherichia coli, Klebsiella species and Proteus mirabilis, and compared the results of boronic acid disc screening with conventional susceptibility testing for the detection of AmpC-positive isolates.

METHODS

E coli, Klebsiella species and P mirabilis with reduced susceptibility to amoxycillin-clavulanate, cefuroxime and cephalexin, but without phenotypic evidence of extended-spectrum beta-lactamases were screened for AmpC activity using enzyme-extraction methods. The presence of plasmid-mediated ampC was determined by multiplex PCR. Antibiotic susceptibilities were determined using both disc and dilution-based methods. A disc-based screening method for detection of AmpC-producing strains was evaluated using boronic acid as an inhibitor of AmpC, and cefoxitin as the antibiotic substrate.

RESULTS

Plasmid-mediated ampC was present in 26% of study isolates, with CMY-like enzymes detected predominantly in E coli and DHA-like enzymes predominantly in Klebsiella pneumoniae. Current susceptibility methods failed to detect a significant proportion of plasmid-mediated AmpC-producing isolates, with 33% of such strains interpreted as susceptible to third-generation cephalosporins using current Clinical Laboratory Standards Institute breakpoints. The boronic acid disc method showed sensitivity and specificity of 90% and 98% respectively in detecting AmpC-positive isolates.

CONCLUSION

The prevalence of plasmid-mediated ampC was high in the study population, and may be missed by conventional susceptibility testing methods. Inhibitor-based screening methods would improve detection of this emerging resistance phenotype.

Salivary duct strictures: nature and incidence in benign salivary obstruction

OBJECTIVES

The aim of this study was to establish the incidence and character of salivary duct strictures by carrying out a 10 year retrospective review. Salivary gland obstruction is most commonly caused either by salivary calculi or duct strictures. These strictures or stenoses develop secondarily to inflammation in the duct wall and may be single or multiple.

METHODS

All reports of sialographic examinations performed on patients referred to the Dental Radiology Department in a London Dental Hospital between 1995 and 2004 were reviewed and those patients with symptoms of salivary obstruction identified. In total, 1362 sialograms using the conventional hand injection technique with water-soluble contrast media were performed on 1349 patients with obstructive symptoms during the 10-year period.

RESULTS

Of the 1362 sialograms performed, the reports revealed that 877 (64.4%) showed evidence of benign intraductal obstruction. The remaining 485 (35.6%) were normal. 642 of the cases (73.2%) revealing obstruction were reported to be due to salivary calculi, 198 due to duct strictures (22.6%) and the remaining 37 (4.2%) were considered to be due to mucous plugs. Detailed analysis of the patients with strictures showed they were more common in women with a mean age of 52 years. Single strictures were evident in 66.7% of cases while 33.3% showed multiple stenoses. Strictures were more common in the parotid duct (75.3%). 7% of patients presented with bilateral stenoses.

CONCLUSION

This is the largest review of duct strictures to be reported. It has shown that ductal stricture formation accounts for almost 25% of cases of benign salivary obstruction and appears to have been an under-recognized condition. Strictures more commonly affect parotid ducts and are typically found in the fourth, fifth or sixth decades, particularly in women.

Comparison of Etest, Vitek and agar dilution for susceptibility testing of colistin

In total, 172 isolates of Enterobacteriaceae, Acinetobacter spp., Pseudomonas aeruginosa and Stenotrophomonas maltophilia were tested for susceptibility to colistin by agar dilution, Etest and the Vitek 2 system. Isolates with a colistin MIC < or =2 mg/L were considered to be susceptible. Fifty-four (31%) Gram-negative isolates were resistant to colistin. Categorical agreement between agar dilution and Etest was 87%, and between agar dilution and Vitek 2 was 82%. Based on the data obtained, the Vitek 2 system was unreliable for detecting colistin resistance, and results obtained by Etest may require confirmation by a standard MIC susceptibility testing method.

Comparison of ultrasound, digital and conventional radiography in differentiating periapical lesions

OBJECTIVES

To carry out an in vivo comparative pilot study to evaluate the efficacy of ultrasound, digital (DR) and conventional plain film-based imaging (PF) in the differential diagnosis of periapical lesions.

METHODS

Fifteen patients aged between 13 years and 40 years with periapical lesions associated with anterior maxillary or mandibular teeth requiring endodontic surgery were selected and consented for the study. Pre-operative periapical radiographs (PF) and charge coupled device (CCD) DR were obtained. Measurements and provisional diagnoses of the apical areas were made by three specialist observers (two dental radiologists and one endodontist) on three separate occasions. Pre-operative ultrasound examinations were then performed and the images assessed by two specialist observers (ultrasonographer and endodontist) for the size, contents, vascular supply and a provisional diagnosis made as to whether the lesion was a cyst or granuloma. Endodontic surgery was performed including curettage of the apical tissues to enable histopathological investigation, which provided the gold standard diagnosis. All measurements and findings were compared and statistically analysed.

RESULTS

On PF and DR the periapical lesions were readily identified but observers were unable to differentiate granuloma from cyst using either modality. Dimensional measurements were subject to greater interobserver variation on DR than on PF. Where sufficient buccal cortical bone had been resorbed, ultrasound imaging was straightforward but underestimated the size of the lesions compared with PF and DR. In all 15 cases, the ultrasound diagnosis agreed with the histopathological gold standard.

CONCLUSIONS

PF and DR enable diagnosis of periapical disease existence, but not of its nature; while ultrasound underestimates the extent of disease, but can provide accurate information on the pathological nature of the lesion.

The in-vitro activity of colistin in gram-negative bacteria

INTRODUCTION

Colistin is a polypeptide antibiotic belonging to the polymyxins, and has been increasingly used for the treatment of multiresistant gram-negative infections. There is little current available data on the susceptibility of gram-negative bacilli to colistin, in part because susceptibility testing for colistin remains problematic, and also because the use of colistin is not widespread. This study tested clinical isolates of gram-negative bacilli for susceptibility to colistin using the reference susceptibility testing method of agar dilution.

METHODS

102 strains of gram-negative bacilli were collected over a one-year period. Antibiotic susceptibility profiles were derived from disc susceptibility testing, and organisms were identified by standard microbiological methods. Isolates were selected for inclusion in the study using susceptibility profiles and epidemiological data. Minimum inhibitory concentrations to colistin were obtained by performing agar dilution according to a standardised method.

RESULTS

30 percent of tested isolates were resistant to colistin. All Acinetobacter spp. and Escherichia coli were susceptible to colistin. Colistin resistance was detected predominantly in Stenotrophomonas maltophilia and Pseudomonas aeruginosa, but was also present in Enterobacter spp. and Klebsiella spp.

CONCLUSION

Colistin resistance is uncommon in the Enterobacteriaceae, but present in a significant proportion of S. maltophilia and P. aeruginosa isolates. From the results of this study, we recommend that susceptibility testing be performed whenever the clinical use of the polymyxins is considered.

Observation of tumour thickness and resection margin at surgical excision of primary oral squamous cell carcinoma—assessment by ultrasound

Tumour thickness and the status of resection margins are of prognostic significance in the treatment of oral cancer. In a single blind prospective study, 14 patients with biopsy proven oral squamous cell carcinoma had intraoral ultrasound imaging done preoperatively to measure tumour thickness, and intraoperatively to measure the deep surgical margin half way during resection. The cut surface was demonstrated on ultrasound by placing a metal, ultrasound-reflective, retractor into the surgical cut. The ultrasound measurements were compared to the subsequent histological measurements. Using the threshold of 5mm as indicator of margin clearance, there was agreement in 10 out of 14 cases between ultrasound and histology. Ultrasound detection of close surgical margins had a sensitivity of 83% and a specificity of 63%. For preoperative tumour thickness measurement, ultrasound imaging showed a high degree of correlation with histology (Pearson correlation coefficient=0.95, P<0.01). This original paper demonstrates that high resolution ultrasound imaging applied intraorally is a reliable tool in objectively assessing both the tumour thickness and the surgical margin clearance at the time of surgery.

Tensile testing of a single ultrafine polymeric fiber

Due to the difficulty in handling micro and nanoscale fibers and measuring the small load required for deformation, mechanical properties of these fibers have not been widely characterized. In this study, tensile test of a single-strand polycaprolactone electrospun ultrafine fiber was performed using a nano tensile tester. The tested fiber exhibited the characteristic low strength and low modulus but high extensibility at room temperature. The mechanical properties were also found to be dependent on fiber diameter. Fibers with smaller diameter had higher strength but lower ductility due to the higher 'draw ratio' that was applied during the electrospinning process.

Diagnostic difficulties of complex root morphology: case study of a lower wisdom tooth

We did a panoramic radiographic examination of a symptomatic lower third molar for surgical planning and risk assessment. This showed a close association with the inferior dental canal, in addition to uncertain root morphology. A periapical radiograph showed evidence of additional smaller curved roots. Axial computed tomography (CT) with coronal reformats did not provide further information about the morphology of the root. After removal of the tooth, its root form was compared with the diagnostic images. The periapical radiograph provided the most information about the morphology of the additional roots. The axial and reformatted coronal CT showed accurately the position and tortuous course of the inferior dental canal.

Ultrasound imaging in the preoperative estimation of the size of tracheostomy tube required in specialised operations in children

BACKGROUND

Some children are dependent on a tracheostomy for many years. As they grow, larger tracheostomy tubes may be required. Although tables of sizes of tracheas exist for different age groups, they are estimations of normal and may not be accurate for atypical cases. Chest radiographs and computed tomograms (CT) have been used experimentally to estimate tracheal sizes, but are not in regular use.

METHOD

High-resolution diagnostic ultrasound imaging was used to estimate the internal and external transverse tracheal diameter, and the depth of the trachea from the skin surface. This allowed selection of the correct standard pattern tracheostomy tube, or the construction of a custom-made tube preoperatively.

RESULTS

Four children with various abnormalities who were being considered for replacement tracheostomies were scanned. In one, diagnostic ultrasound confirmed that a new larger fenestrated tube could be placed, which subsequently improved vocalisation and respiration. In the other three, the scan showed there was no space to allow a larger tube to be placed. The standard tables were not suitable for any of these patients.

CONCLUSION

High-resolution ultrasound has a role in the non-invasive measurement of the size of the tube needed for specialised operations in children.

A new approach using intraoperative ultrasound imaging for the localization and removal of multiple foreign bodies in the neck

An innovative method of using ultrasound imaging intraoperatively is reported. Multiple radiopaque and radiolucent foreign bodies within soft tissues were localized in theatre using high resolution ultrasonography. Depth of injury and vessel status were also ultrasonically assessed. Surgical removal of all foreign bodies was aided by intraoperative ultrasound guidance. In addition, this new approach of using intraoperative ultrasonography was pivotal in confirming the removal of all foreign bodies from the wound at the time of the operation.

Decreased access to health care and social isolation among young adults with cerebral palsy after leaving school

OBJECTIVE

To examine if leaving special schools has a negative impact on the health care and social isolation of young adults with cerebral palsy.

METHODS

Young adults with cerebral palsy, aged between 15 and 22 years, were divided into 2 cohorts: current students, who were still receiving services from special schools, and school-leavers, who had since been discharged from care. A questionnaire and physical examination were administered to assess the extent of disability, health care received by, and social isolation of these young adults.

RESULTS

School-leavers had a greater degree of dissability than did students, although the results were not statistically significant. Health care exposure to specialists, general practitioners, therapists physiotherapists, occupational therapists, and/or speech therapists), and medical social workers decreased after leaving school; with the exception of contact with general practitioners, these results were significant (p<0.05). The entire cohort was more socially isolated than a control cohort. School-leavers participated in fewer activities outside their homes, but showed less concern about their disability than did current students.

CONCLUSIONS

Young adults with cerebral palsy continue to have health care and lifestyle needs after leaving school, which are currently not being adequately met.

Interpretation of skull radiographs for facial fractures by medical staff working in UK emergency departments: a pilot study

OBJECTIVES

This was a pilot study to determine the ability of hospital doctors (1) to assess the technical quality of occipitomental (OM) radiographs and (2) to identify facial fractures.

METHOD

Twenty-two doctors from four UK Accident and Emergency (A&E) departments participated in a two part study: Part A was a postal questionnaire containing questions on demographic data, educational background, selection criteria, assessing radiographs and radiation protection; and Part B was a clinical viewing session to interpret 20 randomized OM radiographs divided into four groups; technically good and poor without fractures, and technically good and poor with fractures.

RESULTS

Study participants ranged from junior house officers to senior consultants. There was considerable variation in educational background and radiographic interpretation instruction at undergraduate and postgraduate level. OM radiographs constituted 10% of all skull radiographs examined per week, yet only 40% of the doctors felt confident when assessing technical quality. The majority of participants had only a limited knowledge of radiation protection legislation. During the viewing session, only 50% of the participants correctly identified those radiographs with fractures and those with technique errors. There was no significant difference between house officers and other grades of staff. A higher level of seniority did not equate with greater interpretative ability. Subjective confidence in assessing film quality did not correlate with the actual film viewing.

CONCLUSION

Only half of the A&E doctors taking part in the study were able to correctly assess film quality and identify facial fractures on OM radiographs. If the pilot sample is representative, then the findings are of considerable concern.

Development and applications of injectable poly(ortho esters) for pain control and periodontal treatment

Poly(ortho esters) with a low glass transition temperature are semi-solid materials so that therapeutic agents can be incorporated at room temperature, without the use of solvents, by a simple mixing procedure. When molecular weights are limited to < 5 kDa, such materials are directly injectable using a needle size no larger than 22 gauge. Somewhat hydrophilic polymers can be produced by using the diketene acetal 3,9-diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane and triethylene glycol (TEG), while hydrophobic materials can be produced by using the diketene acetal and 1,10-decanediol. Molecular weight can be reproducibly controlled by using an excess of the diol, or by use of an alcohol that acts as a chain-stopper. Erosion rates can be controlled by varying the amount of latent acid incorporated into the polymer backbone. Toxicology studies using the TEG polymer have been completed and have shown that the polymer is non-toxic. Toxicology studies using the decanediol polymer are underway. Development studies using the TEG polymer aimed at providing a sustained delivery of an analgesic agent to control post-surgical pain are under development and human clinical trials using the decanediol polymer for the treatment of periodontitis are also underway.

A retrospective survey of attitudes toward acceptance of peritoneal dialysis in Chinese end-stage renal failure patients in Hong Kong--from a cultural point of view

OBJECTIVE

We undertook to study the attitudes toward dialysis of patients approaching end-stage renal failure and to analyze those attitudes from a cultural perspective.

SETTING

The study was performed in the pre-dialysis clinic of a tertiary referral renal center.

PATIENTS

All patients of Chinese ethnic origin seen in the pre-dialysis clinic from 1995 to 2000 for assessment of dialysis therapy were included.

METHOD

We performed a retrospective analysis of patient records with regard to attitudes of the patients toward dialysis, reasons for those attitudes, and factors that could lead to a subsequent change in attitude.

RESULTS

We assessed 462 patients over the 6-year period. Their mean age was 65.5 +/- 13.3 years, and 43.9% of the patients had diabetes. Peritoneal dialysis (PD) was offered to 74% of the patients, and hemodialysis (HD) to 3.9%. Among the patients offered PD, only 44% accepted dialysis. After counselling, 54% of the patients who originally declined PD ultimately accepted it. The major reasons for refusing PD were the ideas of "having lived long enough" and "lack of family support." Most other reasons could be overcome by counselling. Only a minority of patients demanded hemodialysis.

CONCLUSIONS

Declining an offer of dialysis was common. Counselling helped patients to accept PD. Certain cultural elements that hindered acceptance of dialysis were involved in the ideas of "having lived long enough" and "lack of family support." Those cultural elements should be tackled more specifically during counselling.

Intraoperative ultrasound imaging to aid abscess drainage--a technical note

Diagnostic ultrasound is used widely to identify the presence of fluid collections preoperatively. Although its role in other parts of the body is well established, this report describes the technique of using diagnostic ultrasound intraoperatively to aid drainage of a large fascial space abscess in the head and neck. Following previously inadequate drainage of a large superficial abscess from a blindly placed drain, a second procedure was carried out, using ultrasound imaging to locate the persisting abscess. Furthermore, ultrasound demonstrated the adequacy of drainage and helped the surgeon to position the drain in the correct tissue space. We consider that intraoperative use of ultrasound has a role as a guidance tool to drain superficial fascial space abscesses in the head and neck region.