A stochastic model for topographically influenced cell migration

Migrating cells traverse a range of topographic configurations presented by the native extracellular environment to conduct their physiologic functions. It is well documented cells can modulate their behaviour in response to different topographic features, finding promising applications in biomaterial and bioimplant design. It is useful, in these areas of research, to be able to predict which topographic arrangements could be used to promote certain patterns of migration prior to laboratory experimentation. Despite a profusion of study and interest shown in these fields by experimentalists, the related modelling literature is as yet relatively sparse and tend to focus more on either cell-matrix interaction or morphological responses of cells. We propose a mathematical model for individual cell migration based on an Ornstein-Uhlenbeck process, and set out to see if the model can be used to predict migration patterns on 2-d isotropic and anisotropic topographies, whose characteristics can be broadly described as either uniform flat, uniform linear with variable ridge density or non-uniform disordered with variable feature density. Results suggest the model is capable of producing realistic patterns of migration for flat and linear topographic patterns, with calibrated output closely approximating NIH3T3 fibroblast migration behaviour derived from an experimental dataset, in which migration linearity increased with ridge density and average speed was highest at intermediate ridge densities. Exploratory results for non-uniform disordered topographies suggest cell migration patterns may adopt disorderedness present in the topography and that 'distortion' introduced to linear topographic patterns may not impede linear guidance of migration, given its magnitude is bounded within certain limits. We conclude that an Ornstein-Uhlenbeck based model for topographically influenced migration may be useful to predict patterns of migration behaviour for certain isotropic (flat) and anisotropic (linear) topographies in the NIH3T3 fibroblast cell line, but additional investigation is required to predict with confidence migration patterns for non-uniform disordered topographic arrangements.

Use of symptom-guided physical activity and exercise rehabilitation for COVID-19 and other postviral conditions

There are many similarities in symptoms between postviral conditions, including clinical features such as fatigue, reduced daily activity and postexertional symptom exacerbation. Unfavourable responses to exercise have influenced the wider debate on how to reintegrate physical activity (PA) and exercise while simultaneously managing symptoms during recovery from post-COVID-19 syndrome (or Long COVID). This has resulted in inconsistent advice from the scientific and clinical rehabilitation community on how and when to resume PA and exercise following COVID-19 illness. This article provides commentary on the following topics: (1) controversies surrounding graded exercise therapy as a treatment modality for post-COVID-19 rehabilitation; (2) evidence supporting PA promotion, resistance exercise and cardiorespiratory fitness for population health, and the consequences of physical inactivity in patients with complex rehabilitation needs; (3) population-based challenges for UK Defence Rehabilitation practitioners for the management of postviral conditions; and (4) 'symptom guided PA and exercise rehabilitation' as an appropriate treatment option for managing individuals with multifaceted medical needs.

Movement Foundations. The perceived impact of a digital rehabilitation tool for returning to fitness following a period of illness, including COVID-19 infection: a qualitative study

Digital interventions can increase physical activity (PA) levels in adults. However, the COVID-19 pandemic highlighted the complexities faced when guiding people to start or return to PA following illness or inactivity. A digital tool, Movement Foundations, was developed to provide remote guidance on building strength and capacity across functional movement patterns, with graduated progression based on user responses and input. This qualitative study aimed to explore the perceived impacts of using the tool. Nine participants aged over 35 years from the healthcare and academic healthcare sectors were recruited to use it and were subsequently interviewed. Thematic analysis identified three themes falling under the overarching concept of ‘Capability, Opportunity and Motivation—Behaviour (COM-B) Plus’, encompassing: skills and capacity for movement; opportunities, motivations and barriers for movement; and a personalised, safe space in which to develop. Participants felt that the digital tool increased their capacity and confidence in movement and positively impacted their daily activities. External factors such as illness and stress clouded perceptions of the impacts of PA. Time, work pressures and needing equipment were still considered significant barriers to PA. Still, participants appreciated the flexibility and non-prescriptive nature of the tool and felt that it helped movement to become opportunistic and habitual. Increased capacity for PA and feeling the subsequent physical and mental effects positively influenced motivation. Structure and guidance, with graduated progress, were seen as protective. Guided self-reflection helped participants understand their capacity and limitations with regard to movement and promoted motivation. Although acquiring technical skills to guide movement may be important for those recovering from illness, participants found that a structure promoting individualised guidance, graduated progression and guided self-reflection were important motivational factors for continuing use. Digital interventions should consider these aspects when seeking to promote habitual PA.

Surgical tracheostomy in a patient with a stuck tracheal tube in situ

The inability to extubate a patient's trachea due to a mechanical complication is rarely encountered in clinical practice. The risks of attempting to remove a stuck tracheal tube include laryngeal trauma, vocal cord injury and arytenoid dislocation, all of which have significant implications. Here, we report the case of a patient who was admitted to the intensive care unit for mechanical ventilation following liver transplant surgery. Her trachea was initially extubated on the second postoperative day, but she required further mechanical ventilation the following day and her trachea was re-intubated. Five days later, she was deemed suitable for tracheal extubation, but the formation of granulation tissue around the tracheal tube prevented its removal. A multi-disciplinary decision-making approach was taken when deciding to site a surgical tracheostomy. A flexible bronchoscope was used as an aid for safe placement. This facilitated safe extrication of the tracheal tube, which was freed by gentle manipulation both proximally and distally. We suspect that tracheal tube size may have been a factor in the development of the granulation tissue in this case. It is important to consider tracheal tube size in all patients, particularly if they require tracheal re-intubation or are likely to require mechanical ventilation for a prolonged period.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Maternal serum fructosamine levels and stillbirth: a case-control study of the Stillbirth Collaborative Research Network

OBJECTIVE

To evaluate the association between maternal fructosamine levels at the time of delivery and stillbirth.

DESIGN

Secondary analysis of a case-control study.

SETTING

Multicentre study of five geographic catchment areas in the USA.

POPULATION

All singleton stillbirths with known diabetes status and fructosamine measurement, and representative live birth controls.

MAIN OUTCOME MEASURES

Fructosamine levels in stillbirths and live births among groups were adjusted for potential confounding factors, including diabetes. Optimal thresholds of fructosamine to discriminate stillbirth and live birth.

RESULTS

A total of 529 women with a stillbirth and 1499 women with a live birth were included in the analysis. Mean fructosamine levels were significantly higher in women with a stillbirth than in women with a live birth after adjustment (177 ± 3.05 versus 165 ± 2.89 μmol/L, P < 0.001). The difference in fructosamine levels between stillbirths and live births was greater among women with diabetes (194 ± 8.54 versus 162 ± 3.21 μmol/L), compared with women without diabetes (171 ± 2.50 versus 162 ± 2.56 μmol/L). The area under the curve (AUC) for fructosamine level and stillbirth was 0.634 (0.605-0.663) overall, 0.713 (0.624-0.802) with diabetes and 0.625 (0.595-0.656) with no diabetes.

CONCLUSIONS

Maternal fructosamine levels at the time of delivery were higher in women with stillbirth compared with women with live birth. Differences were substantial in women with diabetes, suggesting a potential benefit of glycaemic control in women with diabetes during pregnancy. The small differences noted in women without diabetes are not likely to justify routine screening in all cases of stillbirth.

TWEETABLE ABSTRACT

Maternal serum fructosamine levels are higher in women with stillbirth than in women with live birth, especially in women with diabetes.

The influence of pain, kinesiophobia and psychological comorbidities on the accuracy of rating of perceived exertion in UK military spinal rehabilitation

INTRODUCTION

Chronic low back pain (CLBP) is a leading cause of disability in the UK Military. Pain and psychological comorbidities have been reported to influence the rating of perceived exertion (RPE). Exercise rehabilitation can be monitored using RPE; however, the accuracy of RPE in inpatient CLBP rehabilitation is unknown.

METHODS

A prospective cohort correlation study of 40 UK Military inpatients with CLBP was completed. Disability (ODI), kinesiophobia (TSK), anxiety (GAD-7) and depression (PHQ-9) were subjectively reported at the beginning and end of a 3 week intervention. Pain (VAS) and HR were recorded in the first aerobic exercise (AE) session (T1) and the final aerobic exercise session (T2). RPE was reported for each AE session.

RESULTS

At T1, a positive correlation was observed between RPE accuracy (-7.2±20.9), and pre-exercise pain (2.7 mm ±1.6 mm) (p>0.001) and ODI (31.0±16.9) (p>0.05), and a negative relationship between RPE accuracy and average HR (135 bpm ±22 bpm) (p>0.001) was observed. At T2, there was no significant correlation between RPE accuracy (-4.4±22.6) and pre-exercise pain (2.8 mm ±1.6 mm) or ODI (34.0±16.5) (p>0.05). The strong negative relationship between RPE accuracy and average HR (137 bpm ±20 bpm) remained at T2. Improved RPE accuracy over the 3-week rehabilitation programme was correlated to the change in average HR (r=-0.314, p<0.05).

CONCLUSIONS

Comorbidities may negatively affect RPE accuracy in CLBP, but the magnitude of the influence reduces over intensive rehabilitation.

Integration of strength training into UK Defence Rehabilitation practice: current trends and future challenges

The use of strength and conditioning (S&C) in musculoskeletal rehabilitation has gained wide acceptance among the rehabilitation community. However, there is an absence of evidence demonstrating how to best integrate the principles of S&C into rehabilitation practice. This article discusses four broad themes: (1) an overview of the UK Defence Rehabilitation care pathway, (2) the historical and current approaches to physical training to support operational readiness of the British Armed Forces, (3) the current and future challenges of integrating S&C into Defence Rehabilitation practice and (4) research priorities relating to the use of S&C in Defence Rehabilitation. We detail the importance of strength/power-based physical attributes within our military population. We recommend that consideration be given to the benefits of an alternative education/coaching-based model to be used during the current 3-week residential care pathway, which aims to ensure effective implementation of therapeutic S&C over a longer period of care.

The current state of PEEK implant osseointegration and future perspectives: a systematic review

Polyetheretherketone (PEEK) has been considered as an alternative to replace surgical metal implants. Several medical applications, including dental and orthopaedic implants, need confirmed osseointegration before functional loading. The present study aims at providing a comprehensive systematic review of the evidence on PEEK implants' osseointegration. A systematic search was conducted using Cochrane library, MEDLINE (PubMed), Ovid MEDLINE, Web of Science and EMBASE databases. Publications were identified in accordance with specific inclusion and exclusion criteria. Eligibility screening, data extraction and quality assessment were performed. The review protocol was registered in PROSPERO (CRD42018116061). A total of 55 articles were reviewed and 29 of the most relevant that met the inclusion criteria were selected. Heterogeneity was identified among the included studies. Several approaches have been applied to enhance PEEK osseointegration, with most in vivo studies conducted on small-scale animal models but no study evaluating the osseointegration of PEEK under cyclic loading. However, PEEK modifications are demonstrated to enhance osseointegration preclinically. Collectively, the present review shows a shortage of evidence, including a lack of comprehensive assessment of osseointegration, the need for large-animal-model tests, the need to assess the effect of loading on the implants and the lack of randomised controlled clinical trials.

2201Coronary angioplasty patients' preferences for information about treatment risks: a survey study

Background

Percutaneous Coronary Intervention (PCI) is the commonest invasive procedure in cardiology. Before treatment consent must be given. As part of this communication process patients receive information about the risks and benefits of PCI and alternative treatments. Published studies tell us that the amount and quality of the information received by patients undergoing PCI is variable; benefits are often overestimated, risks forgotten and alternative treatments not always considered. Very little is known about patients' preferences for PCI risk information. Aim: To describe patients' preferences for formation about PCI treatment risk as part of the informed consent process Methods: A cross-sectional survey was distributed to 350 participants treated with PCI across 10 PCI centres in England.

Results

Three hundred and twenty six participants completed the survey. Thirty percent of the sample reported needing help to understand written medical information. Fifty-one percent were treated with elective PCI, 75% were male, average age of 66.5 years. Recall and comprehension of PCI information given during the consent process was generally limited; 47% and 61% agreed that patients do not usually understand, or remember, the information given to them respectively. Eighty-eight percent of urgent PCI patients wanted to know about all possible risks compared to 90% of elective cases. Most participants (88% urgent and 94% elective) believed that PCI would reduce their risk of a future heart attack.

Conclusion

A significant proportion of PCI patients find it difficult to recall or understand information about treatment risks. It is recommended that patients are given health-related information designed to accommodate different health literacy levels in advance of their treatment.

Acknowledgement/Funding

National Institute for Health Research Research for Patient Benefit Programme Grant Reference Number PB-PG-0712-28089

Cognitive functional therapy (CFT)-based rehabilitation improves clinical outcomes in UK military personnel with persistent low back pain

Introduction

Low back pain (LBP) has been reported as the most common reason for presentation to the Medical Centre in the British Military, and the most common re-referral for the same condition. In 2015, the UK Defence Medical Rehabilitation Centre (DMRC) adopted a cognitive functional therapy (CFT) approach to spinal rehabilitation in line with National Institute for Health and Care Excellence and military best practice guidelines. The aim of this study is to evaluate the functional and psychosocial outcomes of all patients with chronic LBP treated with CFT-based multidisciplinary rehabilitation at DMRC, Headley Court.

Methods

A prospective observational service evaluation of British Military patients (n=238) with LBP who attended 3 weeks of inpatient multidisciplinary CFT-based programme from 2015 to the end of 2017 at DMRC was analysed. Functional outcomes include: multistage locomotion test (MSLT) and sit and reach test. Psychosocial outcomes include: Tampa Scale of Kinesiophobia, Oswestry Disability Index, Brief Pain Inventory (BPI), General Anxiety Disorder-7 and Patient Health Questionnaire-9.

Results

There were significant improvements in endurance (MSLT), range of motion, kinesiophobia, pain-related lifestyle interference (BPI-Lifestyle), anxiety and depression (p≤0.001). However, no improvements in pain intensity (BPI-Intensity) were demonstrated (p>0.05).

Conclusion

After 3 weeks of CFT-based multidisciplinary rehabilitation, function and psychosocial health improved with symptoms of pain being less obtrusive to activities of daily activity. There were however no patient-reported reductions in pain intensity. The improvements demonstrated are indicative of outcomes that facilitate greater integration back to work or into society.

Low-Load Resistance Training With Blood Flow Restriction Improves Clinical Outcomes in Musculoskeletal Rehabilitation: A Single-Blind Randomized Controlled Trial

Background: There is growing evidence to support the use of low-load blood flow restriction (LL-BFR) exercise in musculoskeletal rehabilitation.

Purpose: The purpose of this study was to evaluate the efficacy and feasibility of low-load blood flow restricted (LL-BFR) training versus conventional high mechanical load resistance training (RT) on the clinical outcomes of patient’s undergoing inpatient multidisciplinary team (MDT) rehabilitation.

Study design: A single-blind randomized controlled study.

Methods: Twenty-eight lower-limb injured adults completed a 3-week intensive MDT rehabilitation program. Participants were randomly allocated into a conventional RT (3-days/week) or twice-daily LL-BFR training group. Outcome measurements were taken at baseline and 3-weeks and included quadriceps and total thigh muscle cross-sectional area (CSA) and volume, muscle strength [five repetition maximum (RM) leg press and knee extension test, isometric hip extension], pain and physical function measures (Y-balance test, multistage locomotion test—MSLT).

Results: A two-way repeated measures analysis of variance revealed no significant differences between groups for any outcome measure post-intervention (p > 0.05). Both groups showed significant improvements in mean scores for muscle CSA/volume, 5-RM leg press, and 5-RM knee extension (p < 0.01) after treatment. LL-BFR group participants also demonstrated significant improvements in MSLT and Y-balance scores (p < 0.01). The Pain scores during training reduced significantly over time in the LL-BFR group (p = 0.024), with no adverse events reported during the study.

Conclusion: Comparable improvements in muscle strength and hypertrophy were shown in LL-BFR and conventional training groups following in-patient rehabilitation. The LL-BFR group also achieved significant improvements in functional capacity. LL-BFR training is a rehabilitation tool that has the potential to induce positive adaptations in the absence of high mechanical loads and therefore could be considered a treatment option for patients suffering significant functional deficits for whom conventional loaded RT is contraindicated.

Trial Registration: ISRCTN Reference: ISRCTN63585315, dated 25 April 2017.

The effects of low-intensity blood flow restricted exercise compared with conventional resistance training on the clinical outcomes of active UK military personnel following a 3-week in-patient rehabilitation programme: protocol for a randomized controlled feasibility study

Background

A challenge for rehabilitation practitioners lies in designing optimal exercise programmes that facilitate musculoskeletal (MSK) adaptations whilst simultaneously accommodating biological healing and the safe loading of an injured limb. A growing body of evidence supports the use of resistance training at a reduced load in combination with blood flow restriction (BFR) to enhance hypertrophic and strength responses in skeletal muscle. In-patient rehabilitation has a long tradition in the UK Military, however, the efficacy of low intensity (LI) BFR training has not been tested in this rehabilitation setting. The aims of this study are to determine (1) the feasibility of a randomised controlled trial (RCT) investigating LI-BFR training in a residential, multidisciplinary treatment programme and (2) provide preliminary data describing the within and between-group treatment effects of a LI-BFR intervention and a conventional resistance training group in military personnel.

Methods

This is a single-blind randomised controlled feasibility study. A minimum of 28 lower-limb injured UK military personnel, aged 18 to 50 years, attending rehabilitation at the UK Defence Medical Rehabilitation Centre (DMRC) will be recruited into the study. After completion of baseline measurements, participants will be randomised in a 1:1 ratio to receive 3 weeks (15 days) of intensive multidisciplinary team (MDT) in-patient rehabilitation. Group 1 will receive conventional resistance training 3 days per week. Group 2 will perform twice daily LI-BFR training. Both groups will also undertake the same common elements of the existing MDT programme. Repeat follow-up assessments will be undertaken upon completion of treatment. Group 2 participants will be asked to rate their pain response to LI-BFR training every five sessions.

Discussion

The results will provide information on the feasibility of a full-scale RCT. Recommendations for an adequately powered study to determine the efficacy of LI-BFR training during in-patient rehabilitation can then be made. The study may also provide insights into the potential effectiveness of LI-BFR training as a novel exercise modality to induce muscle adaptations in the absence of high mechanical loading of the lower-limb.

Trial registration

ISRCTN Reference: ISRCTN 63585315 dated 25 April 2017.

Pattern analysis of microtubule-polymerizing and -depolymerizing agent combinations as cancer chemotherapies

Subcellular distribution of mass can be analyzed by a technique that involves culturing cells on interferometers and digitizing their interference contours. Contour sampling resulted in 102 variables per cell, which were predictors of oncogenic transformation. Cell phenotypes can be deconstructed by use of latent factors, which represent the covariance of the real variables. The reversal of the cancer-type phenotype by a combination of microtubule-stabilizing and -depolymerizing agents was described previously. The implications of these results have been explored by clinicians who treated patients with the combination of docetaxel and vinorelbine (Navelbine). The current study was performed to determine the effects of different combinations on phenotype and in phases of the cell cycle other than mitosis. Combinations of paclitaxel with either colchicine, podophyllotoxin, nocodazole, or vinblastine caused phenotype reversal. Paclitaxel analogue, 7-deoxytaxol, by itself caused reversal. Factors #4, (filopodia), #5 (displacement and/or deep invaginations in the periphery), #8, and #12 took on values typical of normal cells, whereas the values of #7 (p21-activated kinase), and #13 (rounding up) shifted toward the cancer-type. All combinations altered microtubule arrangement at the cell edge. Delivery schedules and drug ratios used in clinical studies were subjected to analysis. Clinical response rates were better when the combination was not interspersed with a single agent (P=0.004). The results support the idea that efficacy depends upon simultaneous exposure to both agents, and suggest a novel mechanism for combination therapies. These therapies appear to restore in transformed cells some of the features of a contact-inhibited cell, and to impede progress through the cell cycle even when provided at nanomolar concentrations.

Inclusion of Vpr accessory gene in a plasmid vaccine cocktail markedly reduces Nef vaccine effectiveness in vivo resulting in CD4 cell loss and increased viral loads in rhesus macaques

We compared the immunogenicity of plasmid vaccines containing multiple human immunodeficiency virus (HIV) antigens and found that covaccination with plasmids expressing HIV-1 14 kDa vpr gene product profoundly reduces antigen-specific CD8-mediated cytotoxic T-cell activity (CTL). Interestingly, Th1 type responses against codelivered antigens (pGag-Pol, pNef, etc.) encoded by the plasmid vaccines were suppressed. This suggested that vpr might compromise CD8 T-cell immunity in vivo during infection. A pilot primate vaccine study was designed to test the hypothesis to compare the following groups: unvaccinated controls, animals vaccinated without simean immunodeficiency virus (SIV)-Nef antigen plasmid, and animals covaccinated with the identical plasmid antigen and a plasmid construct encoding SIV Vpr/Vpx. Animals were subsequently challenged intrarectally with pathogenic SIVmac251 after the final vaccination of a multiple immunization protocol. Control animals were all infected and exhibited high viral loads and rapid CD4+ T-cell loss. In contrast, the Nef plasmid-vaccinated animals were also infected but exhibited preservation of CD4+ T-cells and a multilog reduction in viral load compared with controls. Animals covaccinated multiple times with the Nef vaccine and pVpr/Vpx plasmid suffered rapid and profound loss of CD4+ T-cells. These results have important implications for the design of multicomponent and particle vaccines for HIV-1 as well as for our understanding of HIV/SIV pathogenesis in vivo.

Simulation of the impacts of climate change on groundwater resources in eastern England

This study investigated the impacts of climate change on the Chalk aquifer in west Norfolk. A two-layer transient groundwater flow model of the aquifer system was calibrated and validated for the period 1980–1995 and provided the historic flow record for the climate change simulations. Two future scenarios were selected from the Hadley Centre’s climate change experiments using HadCM2: (1) a medium-high (MH) emissions scenario; and (2) a medium-low (ML) emissions scenario of ‘greenhouse’ gases. Two future periods were considered: 2020–2035 and 2050–2065. Future recharge to the aquifer was estimated by adjusting the historic record of monthly precipitation and potential evapotranspiration by factors calculated from comparing control and future HadCM2-generated values. Impacts of climate change were evaluated by incorporating the monthly estimated recharge inputs within the flow model. The most noticeable and consistent result of the climate change impact simulations is the decrease in recharge expected in autumn for all scenarios (decreases ranging from 17 to 35%) as a consequence of the smaller amount of summer precipitation and increased autumn potential evapotranspiration. For the 2050MH scenario, these conditions lead to a 42 0ncrease in autumn soil moisture deficit and a 26% reduction in recharge. Hence, west Norfolk can expect longer and drier summers that are predicted to have relatively little effect on summer groundwater levels (generally a 1 to 2 0ecrease) but will result in a decrease of up to 14 0n autumn river baseflow volumes.

Use of intraoperative cytologic assessment of mandibular marrow scrapings to predict resection margin status in patients with squamous cell carcinoma

PURPOSE

This study assessed the feasibility of intraoperative microscopic assessment of mandibular bone resection margins in patients undergoing segmental resection of mandible for treatment of squamous cell carcinoma.

PATIENTS AND METHODS

This prospective pilot study involved 7 consecutive patients undergoing segmental resection of mandible as part of surgical treatment of oral squamous cell carcinoma. Cytologic examination of smear/touch preparations of 35 bone marrow scrapings, including simulated positive margins, was performed.

RESULTS

"Malignant" excision margins produced a high cell yield, and it was easy to assign samples to malignant or benign categories on microscopic examination. All the simulated positive margins were easily identified. No false positive results were found.

CONCLUSION

Cytologic examination of bone excision margin scrapings is a rapid, inexpensive, and accurate technique. This study confirms its feasibility and accuracy in cases of mandibular resection for squamous cell carcinoma.

Neuromuscular monitoring in intensive care patients: milliamperage requirements for supramaximal stimulation

We investigated the effects of peripheral oedema on the supramaximal current required for neuromuscular monitoring of critically ill patients. We studied 32 sedated patients who had not needed a neuromuscular blocking drug. The presence of oedema over the volar aspect of both wrists was assessed by a blinded observer and graded (grade 0, no oedema; grade 1, mild oedema; grade 2, gross oedema). The supramaximal current was derived by applying an incrementally increasing current over the ulnar nerve and measuring the amplitude of the electromyographic (EMG) response of the first dorsal interosseous muscle. The supramaximal current was that current above which there was no significant increase in EMG amplitude. It was 40 mA in the absence of oedema. This current was significantly increased in the presence of grade 1 oedema (60 mA, Mann-Whitney test, P<0.01) and grade 2 oedema (82.5 mA, Mann-Whitney test, P<0.01). In the presence of oedema, the required supramaximal current decreased significantly after the application of pressure over the stimulating electrodes (Wilcoxon signed rank test, P<0.05). Supramaximal current in critically ill patients is increased in the presence of peripheral oedema. We recommend that nerve stimulators used for neuromuscular monitoring in the ICU are capable of delivering a stimulus current of at least 100 mA.

Ecthyma gangrenosum as a manifestation of Pseudomonas sepsis in a previously healthy child

We present a case of Pseudomonas aeruginosa sepsis heralded by ecthyma gangrenosum in a previously healthy 15-month-old child. Pseudomonas infection and its uncommon skin manifestation are rarely encountered in an immunocompetent child. This case highlights the critical importance of identifying ecthyma gangrenosum to institute optimal antimicrobial therapy.