The corticomuscular response to experimental pain via blood flow occlusion when applied to the ipsilateral and contralateral leg during an isometric force task

Blood flow occlusion (BFO) has been previously used to investigate physiological responses to muscle ischemia, showing increased perceptual effort (RPE) and pain along with impaired neuromuscular performance. However, at present, it is unclear how BFO alters corticomuscular activities when either applied to the exercising or nonexercising musculature. The present study therefore set out to assess the corticomuscular response to these distinct BFO paradigms during an isometric contraction precision task. In a repeated measures design, fifteen participants (age = 27.00 ± 5.77) completed 15 isometric contractions across three experimental conditions; no occlusion (CNTRL), occlusion of the contralateral (i.e., nonexercising) limb (CON-OCC), and occlusion of the ipsilateral (i.e., exercising) limb (IPS-OCC). Measures of force, electroencephalographic (EEG), and electromyographic (EMG) were recorded during contractions. We observed that IPS-OCC broadly impaired force steadiness, elevated EMG of the vastus lateralis, and heightened RPE and pain. IPSI-OCC also significantly decreased corticomuscular coherence during the early phase of contraction and decreased EEG alpha activity across the sensorimotor and temporoparietal regions during the middle and late phases of contraction compared with CNTRL. By contrast, CON-OCC increased perceived levels of pain (but not RPE) and decreased EEG alpha activity across the prefrontal cortex during the middle and late phases of contraction, with no changes observed for EMG and force steadiness. Together, these findings highlight distinctive psychophysiological responses to experimental pain via BFO showing altered cortical activities (CON-OCC) and altered cortical, corticomuscular, and neuromuscular activities (IPS-OCC) when applied to the lower limbs during an isometric force precision task.

The current use of ultrasound to measure skeletal muscle and its ability to predict clinical outcomes: a systematic review

Quantification and monitoring of lean body mass is an important component of nutrition assessment to determine nutrition status and muscle loss. The negative impact of reduced muscle mass and muscle function is increasingly evident across acute and chronic disease states but is particularly pronounced in patients with cancer. Ultrasound is emerging as a promising tool to directly measure skeletal muscle mass and quality. Unlike other ionizing imaging techniques, ultrasound can be used repeatedly at the bedside and may compliment nutritional risk assessment. This review aims to describe the current use of skeletal muscle ultrasound (SMUS) to measure muscle mass and quality in patients with acute and chronic clinical conditions and its ability to predict functional capacity, severity of malnutrition, hospital admission, and survival. Databases were searched from their inception to August 2021 for full-text articles in English. Relevant articles were included if SMUS was investigated in acute or chronic clinical contexts and correlated with a defined clinical outcome measure. Data were synthesized for narrative review due to heterogeneity between studies. This review analysed 37 studies (3100 patients), which met the inclusion criteria. Most studies (n = 22) were conducted in critical care. The clinical outcomes investigated included functional status at discharge (intensive care unit-acquired weakness), nutritional status, and length of stay. SMUS was also utilized in chronic conditions such as chronic obstructive pulmonary disease, chronic heart failure, and chronic renal failure to predict hospital readmission and disease severity. Only two studies investigated the use of SMUS in patients with cancer. Of the 37 studies, 28 (76%) found that SMUS (cross-sectional area, muscle thickness, and echointensity) showed significant associations with functional capacity, length of stay, readmission, and survival. There was significant heterogeneity in terms of ultrasound technique and outcome measurement across the included studies. This review highlights that SMUS continues to gain momentum as a potential tool for skeletal muscle assessment and predicting clinically important outcomes. Further work is required to standardize the technique in nutritionally vulnerable patients, such as those with cancer, before SMUS can be widely adopted as a bedside prognostic tool.

Associations between childhood and adulthood socioeconomic position and grip strength at age 46 years: findings from the 1970 British Cohort Study

BACKGROUND

Muscle weakness is a key criterion for important age-related conditions, including sarcopenia and frailty. Research suggests lower childhood socioeconomic position (SEP) may be associated with muscle weakness in later life but there is little evidence on associations in younger adults closer to peak muscle strength. We aimed to examine relationships between indicators of SEP in childhood and adulthood and grip strength at age 46y.

METHODS

We examined 7,617 participants from the 1970 British Cohort Study with grip strength measurements at 46y. We used sex-specific linear regression models to test associations between five different indicators of SEP in childhood and adulthood (paternal occupational class and parental education levels at age 5 and own occupational class and education level at age 46) and maximum grip strength. Models were adjusted for birth weight, BMI in childhood and adulthood, adult height, disability in childhood, leisure-time physical activity in childhood and adulthood, sedentary behaviour in childhood and adulthood, occupational activity and smoking at age 46.

RESULTS

Among women, lower SEP in childhood and adulthood was associated with weaker grip strength even after adjustments for covariates. For example, in fully-adjusted models, women whose mothers had no qualifications at age five had mean grip strength 0.99 kg (95% CI: -1.65, -0.33) lower than women whose mothers were educated to degree and higher. Among men, lower levels of father's education and both adult SEP indicators were associated with stronger grip. The association between own occupational class and grip strength deviated from linearity; men in skilled-manual occupations (i.e. the middle occupational group) had stronger grip than men in the highest occupational group (Difference in means: 1.33 kg (0.60, 2.06)) whereas there was no difference in grip strength between the highest and lowest occupational groups. Adjustment for occupational activity largely attenuated these associations.

CONCLUSION

Findings highlight the need to identify age and sex-specific interventions across life to tackle inequalities in important age-related conditions related to weakness.

Age-related alterations in muscle architecture are a signature of sarcopenia: the ultrasound sarcopenia index

BACKGROUND

The assessment of muscle mass is a key determinant of the diagnosis of sarcopenia. We introduce for the first time an ultrasound imaging method for diagnosing sarcopenia based on changes in muscle geometric proportions.

METHODS

Vastus lateralis muscle fascicle length (Lf) and thickness (Tm) were measured at 35% distal femur length by ultrasonography in a population of 279 individuals classified as moderately active elderly (MAE), sedentary elderly (SE) (n = 109), mobility impaired elderly (MIE) (n = 43), and in adult young controls (YC) (n = 60). The ratio of Lf/Tm was calculated to obtain an ultrasound index of the loss of muscle mass associated with sarcopenia (USI). In a subsample of elderly male individuals (n = 76) in which corresponding DXA measurements were available (MAE, n = 52 and SE, n = 24), DXA-derived skeletal muscle index (SMI, appendicular limb mass/height2 ) was compared with corresponding USI values.

RESULTS

For both young and older participants, USI values were found to be independent of sex, height and body mass. USI values were 3.70 ± 0.52 for YC, 4.50 ± 0.72 for the MAE, 5.05 ± 1.11 for the SE and 6.31 ± 1.38 for the MIE, all significantly different between each other (P < 0.0001). Based on the USI Z-scores, with reference to the YC population, the 219 elderly participants were stratified according to their muscle sarcopenic status. Individuals with USI values within a range of 3.70 < USI ≥ 4.23 were classified as non-sarcopenic (prevalence 23.7%), those with USI values within 4.23 < USI ≥ 4.76 were classified as pre-sarcopenic (prevalence 23.7%), those with USI values within 4.76 < USI ≥ 5.29 were classified as moderately sarcopenic (prevalence 15.1%), those with USI values within range 5.29 < USI ≥ 5.82 were classified as sarcopenic (prevalence 27.9%), and those with USI values >5.82 were classified as severely sarcopenic (prevalence 9.6%). The DXA-derived SMI was found to be significantly correlated with USI (r = 0.61, P < 0.0001). Notably, the USI cut-off value for moderate sarcopenia (4.76 a.u.) was found to coincide with the DXA cut-off value of sarcopenia (7.26 kg/m2 ).

CONCLUSIONS

We propose a novel, practical, and inexpensive imaging marker of the loss of muscle mass associated with sarcopenia, called the ultrasound sarcopenic index (USI), based on changes in muscle geometric proportions. These changes provide a useful 'signature of sarcopenia' and allow the stratification of individuals according to the presence and severity of muscle sarcopenia. We are convinced that the USI will be a useful clinical tool for confirming the diagnosis of sarcopenia, of which the assessment of muscle mass is a key-component.

Determinants of Performance in the Timed Up-and-Go and Six-Minute Walk Tests in Young and Old Healthy Adults

The aim of this study was to assess associations between performance in the timed up-and-go (TUG) and six-minute walk distance (6MWD) with physiological characteristics in young and old healthy adults. Thereto, we determined TUG, 6MWD, normalised jump power, centre of pressure displacement during 1-leg standing, forced expiratory volume in 1 s, percentage of age-predicted maximal heart rate (HR%) and height in 419 healthy young (men: 23.5 ± 2.8 years, women: 23.2 ± 2.9 years) and old (men: 74.6 ± 3.2 years, women: 74.1 ± 3.2 years) adults. Normalised jump power explained 8% and 19% of TUG in young (p = 0.025) and older men (p < 0.001), respectively. When fat mass percentage and age were added to normalised jump power, 30% of TUG was explained in older men (R2adj = 0.30, p < 0.001 to 0.106). Appendicular lean muscle mass percentage (ALM%) and age were the best determinants of TUG for older women (R2adj = 0.16, p < 0.001 to 0.01). HR% explained 17-39% of 6MWD across all groups (R2adj = 0.17 to 39, p < 0.001). In conclusion, in men, jump power was a key determinant for TUG, while in old women only it was the ALM%. As HR% was the most important determinant of 6MWD, motivational bias needs to be considered in the interpretation of this test.

A new process to measure postural sway using a Kinect depth camera during a Sensory Organisation Test

Posturography provides quantitative, objective measurements of human balance and postural control for research and clinical use. However, it usually requires access to specialist equipment to measure ground reaction forces, which are not widely available in practice, due to their size or cost. In this study, we propose an alternative approach to posturography. It uses the skeletal output of an inexpensive Kinect depth camera to localise the Centre of Mass (CoM) of an upright individual. We demonstrate a pipeline which is able to measure postural sway directly from CoM trajectories, obtained from tracking the relative position of three key joints. In addition, we present the results of a pilot study that compares this method of measuring postural sway to the output of a NeuroCom SMART Balance Master. 15 healthy individuals (age: 42.3 ± 20.4 yrs, height: 172 ± 11 cm, weight: 75.1 ± 14.2 kg, male = 11), completed 25 Sensory Organisation Test (SOT) on a NeuroCom SMART Balance Master. Simultaneously, the sessions were recorded using custom software developed for this study (CoM path recorder). Postural sway was calculated from the output of both methods and the level of agreement determined, using Bland-Altman plots. Good agreement was found for eyes open tasks with a firm support, the agreement decreased as the SOT tasks became more challenging. The reasons for this discrepancy may lie in the different approaches that each method takes to calculate CoM. This discrepancy warrants further study with a larger cohort, including fall-prone individuals, cross-referenced with a marker-based system. However, this pilot study lays the foundation for the development of a portable device, which could be used to assess postural control, more cost-effectively than existing equipment.

Dysregulation of C-X-C motif ligand 10 during aging and association with cognitive performance

Chronic low-grade inflammation during aging (inflammaging) is associated with cognitive decline and neurodegeneration; however, the mechanisms underlying inflammaging are unclear. We studied a population (n = 361) of healthy young and old adults from the MyoAge cohort. Peripheral levels of C-X-C motif chemokine ligand 10 (CXCL10) was found to be higher in older adults, compared with young, and negatively associated with working memory performance. This coincided with an age-related reduction in blood DNA methylation at specific CpGs within the CXCL10 gene promoter. In vitro analysis supported the role of DNA methylation in regulating CXCL10 transcription. A polymorphism (rs56061981) that altered methylation at one of these CpG sites further associated with working memory performance in 2 independent aging cohorts. Studying prefrontal cortex samples, we found higher CXCL10 protein levels in those with Alzheimer's disease, compared with aged controls. These findings support the association of peripheral inflammation, as demonstrated by CXCL10, in aging and cognitive decline. We reveal age-related epigenetic and genetic factors which contribute to the dysregulation of CXCL10.

Targeting miR-423-5p Reverses Exercise Training-Induced HCN4 Channel Remodeling and Sinus Bradycardia

Supplemental Digital Content is available in the text.

Rationale:

Downregulation of the pacemaking ion channel, HCN4 (hyperpolarization-activated cyclic nucleotide gated channel 4), and the corresponding ionic current, I_f, underlies exercise training–induced sinus bradycardia in rodents. If this occurs in humans, it could explain the increased incidence of bradyarrhythmias in veteran athletes, and it will be important to understand the underlying processes.

Objective:

To test the role of HCN4 in the training-induced bradycardia in human athletes and investigate the role of microRNAs (miRs) in the repression of HCN4.

Methods and Results:

As in rodents, the intrinsic heart rate was significantly lower in human athletes than in nonathletes, and in all subjects, the rate-lowering effect of the HCN selective blocker, ivabradine, was significantly correlated with the intrinsic heart rate, consistent with HCN repression in athletes. Next-generation sequencing and quantitative real-time reverse transcription polymerase chain reaction showed remodeling of miRs in the sinus node of swim-trained mice. Computational predictions highlighted a prominent role for miR-423-5p. Interaction between miR-423-5p and HCN4 was confirmed by a dose-dependent reduction in HCN4 3′-untranslated region luciferase reporter activity on cotransfection with precursor miR-423-5p (abolished by mutation of predicted recognition elements). Knockdown of miR-423-5p with anti-miR-423-5p reversed training-induced bradycardia via rescue of HCN4 and I_f. Further experiments showed that in the sinus node of swim-trained mice, upregulation of miR-423-5p (intronic miR) and its host gene, NSRP1, is driven by an upregulation of the transcription factor Nkx2.5.

Conclusions:

HCN remodeling likely occurs in human athletes, as well as in rodent models. miR-423-5p contributes to training-induced bradycardia by targeting HCN4. This work presents the first evidence of miR control of HCN4 and heart rate. miR-423-5p could be a therapeutic target for pathological sinus node dysfunction in veteran athletes.

Human limb skeletal muscle wasting and architectural remodeling during five to ten days intubation and ventilation in critical care - an observational study using ultrasound

Background

Critically ill patients frequently suffer muscle weakness whilst in critical care. Ultrasound can reliably track loss of muscle size, but also quantifies the arrangement of the muscle fascicles, known as the muscle architecture. We sought to measure both pennation angle and fascicle length, as well as tracking changes in muscle thickness in a population of critically ill patients.

Methods

On days 1, 5 and 10 after admission to critical care, muscle thickness was measured in ventilated critically ill patients using bedside ultrasound. Elbow flexor compartment, medial head of gastrocnemius and vastus lateralis muscle were investigated. In the lower limb, we determined the pennation angle to derive the fascicle length.

Results

We recruited and scanned 22 patients on day 1 after admission to critical care, 16 were re-scanned on day 5 and 9 on day 10. We found no changes to the size of the elbow flexor compartment over 10 days of admission. In the gastrocnemius, there were no significant changes to muscle thickness or pennation angle over 5 or 10 days. In the vastus lateralis, we found significant losses in both muscle thickness and pennation angle on day 5, but found that fascicle length is unchanged. Loss of muscle on day 5 was related to decreases in pennation angle. In both lower limb muscles, a positive relationship was observed between the pennation angle on day 1, and the percentage of angle lost by days 5 and 10.

Discussion

Muscle loss in critically ill patients preferentially affects the lower limb, possibly due to the lower limb becoming prone to disuse atrophy. Muscle architecture of the thigh changes in the first 5 days of admission, in particular, we have demonstrated a correlation between muscle thickness and pennation angle. It is hypothesised that weakness in the lower limb occurs through loss of force generation via a reduced pennation angle.

Conclusion

Using ultrasound, we have been able to demonstrate that muscle thickness and architecture of vastus lateralis undergo rapid changes during the early phase of admission to a critical care environment.

Human skeletal muscle fibre contractile properties and proteomic profile: adaptations to 3 weeks of unilateral lower limb suspension and active recovery

KEY POINTS

It is generally assumed that muscle fibres go through atrophy following disuse with a loss of specific force and an increase in unloaded shortening velocity. However, the underlying mechanisms remain to be clarified. Most studies have focused on events taking place during the development of disuse, whereas the subsequent recovery phase, which is equally important, has received little attention. Our findings support the hypotheses that the specific force of muscle fibres decreased following unilateral lower limb suspension (ULLS) and returned to normal after 3 weeks of active recovery as a result of a loss and recovery of myosin and actin content. Furthermore, muscle fibres went through extensive qualitative changes in muscle protein pattern following ULLS, and these were reversed by active recovery. Resistance training was very effective in restoring both muscle mass and qualitative muscle changes, indicating that long-term ULLS did not prevent the positive effect of exercise on human muscle.

ABSTRACT

Following disuse, muscle fibre function goes through adaptations such as a loss of specific force (PO /CSA) and an increase in unloaded shortening velocity, which could be a result of both quantitative changes (i.e. atrophy) and qualitative changes in protein pattern. The underlying mechanisms remain to be clarified. In addition, little is known about the recovery of muscle mass and strength following disuse. In the present study, we report an extensive dataset describing, in detail,the functional and protein content adaptations of skeletal muscle in response to both disuse and re-training. Eight young healthy subjects were subjected to 3 weeks of unilateral lower limb suspension (ULLS), a widely used human model of disuse skeletal muscle atrophy. Needle biopsies samples were taken from the vastus lateralis muscle Pre-ULLS, Post-ULLS and after 3 weeks of recovery during which heavy resistance training was performed. After disuse, cross-sectional area (CSA), PO /CSA and myosin concentration (MC) decreased in both type 1 and 2A skinned muscle fibres. After recovery, CSA and MC returned to levels comparable to those observed before disuse, whereas Po/CSA and unloaded shortening velocity reached a higher level. Myosin heavy chain isoform composition of muscle samples did not differ among the experimental groups. To study the mechanisms underlying such adaptations, a two-dimensional proteomic analysis was performed. ULLS induced a reduction of myofibrillar, metabolic (glycolytic and oxidative) and anti-oxidant defence system protein content. Resistance training was very effective in counteracting ULLS-induced alterations, indicating that long-term ULLS did not prevent the positive effect of exercise on human muscle.

Changes of glaciers in the Andes of Chile and priorities for future work

Glaciers in the Andes of Chile seem to be shrinking and possibly loosing mass, but the number and types of studies conducted, constrained mainly by data availability, are not sufficient to provide a synopsis of glacier changes for the past or future or explain in an explicit way causes of the observed changes. In this paper, we provide a systematic review of changes in glaciers for the entire country, followed by a discussion of the studies that have provided evidence of such changes. We identify a missing type of work in distributed, physically-oriented modelling studies that are needed to bridge the gap between the numerous remote sensing studies and the specific, point scale works focused on process understanding. We use an advanced mass balance model applied to one of the best monitored glaciers in the region to investigate four main research issues that should be addressed in modelling studies for a sound assessment of glacier changes: 1) the use of physically-based models of glacier ablation (energy balance models) versus more empirical models (enhanced temperature index approaches); 2) the importance of the correct extrapolation of air temperature forcing on glaciers and in high elevation areas and the large uncertainty in model outputs associated with it; 3) the role played by snow gravitational redistribution; and 4) the uncertainty associated with future climate scenarios. We quantify differences in model outputs associated with each of these choices, and conclude with suggestions for future work directions.

Impact of age, performance and athletic event on injury rates in master athletics - first results from an ongoing prospective study

OBJECTIVES

Recent studies have identified rates of injuries in young elite athletes during major athletic events. However, no such data exist on master athletes. The aim of this study was to assess incidence and types of injuries during the 2012 European Veteran Athletics Championships as a function of age, performance and athletic discipline.

METHODS

Report forms were used to identify injured athletes and injury types. Analysis included age (grouped in five-year bands beginning at age 35 years), athletic event, and age-graded performance.

RESULTS

Of the 3154 athletes (53.2 years (SD 12.3)) that participated in the championships (1004 (31.8%) women, 2150 (68.2%) men), 76 were registered as injured; 2.8% of the female (29), 2.2% of the male (47) athletes. There were no fractures. One injury required operative treatment (Achilles tendon rupture). Injury rates were significantly higher in the sprint/middle distance/jumps than the throws, long distance and decathlon/heptathlon groups (X(2) (3)=16.187, P=0.001). There was no significant interrelationship with age (X(2) (12)=6.495, P=0.889) or age-graded performance (X(2) (3)=3.563, P=0.313).

CONCLUSIONS

The results suggest that healthy master athletes have a low risk of injury that does not increase with age or performance.

Photophosphorylation by monomolecular films at an air-water interface

An acetone extract of chloroplast particles, when layered on an aqueous surface, exhibited light-dependent phosphorylation. Studies with the firefly-tail enzyme assay, as well as with (32)P-labeled inorganic phosphate, show an initial release of adenosine triphosphate (a step that is apparently only light-triggered), followed by a light-dependent uptake of the labeled inorganic phosphate into adenosine diphosphate and adenosine triphosphate.

Mental health and other clinical correlates of euthanasia attitudes in an Australian outpatient cancer population

A majority of patients with cancer have been reported to endorse euthanasia and physician assisted suicide (PAS) in general and a substantial proportion endorse these for themselves. However, the potential influence of mental health and other clinical variables on these decisions is not well understood. This study of 228 outpatients attending an oncology clinic in Newcastle, Australia used a cross-sectional design and logistic regression modelling to examine the relationship of demographic, disease status, mental health and quality of life variables to attitudes toward euthanasia and PAS. The majority reported support for euthanasia (79%, n=179), for PAS (69%, n=158) and personal support for euthanasia/PAS (68%, n=156). However, few reported having asked their doctor for euthanasia (2%, n=5) or PAS (2%, n=5). Three outcomes were modelled: support for euthanasia was associated with active religious belief (adjusted odds ratio (AOR) 0.21, 95% CI: 0.10-0.46); support for PAS was associated with active religious belief (AOR 0.35, 95% CI: 18-0.70) and recent pain (AOR 0.87, 95% CI: 0.0.76-0.99); and personal support for euthanasia/PAS was associated with active religious belief (AOR 0.26, 95% CI: 0.14-0.48). Depression, anxiety, recent suicidal ideation, and lifetime suicide attempt were not independently associated with any of the three outcomes modelled.

Direct-to-consumer advertising under the radar: the need for realistic drugs policy in Australia

Direct-to-consumer advertising of prescription medicines (DTCA-PM) is currently banned in Australia. DTCA-PM is thought to increase health-care costs by increasing demand for drugs that are both expensive and potentially harmful. However, DTCA-PM is occurring in Australia despite the current prohibition. We argue that successful regulation of the practice has been undermined as a result of changes brought about by the ongoing communications revolution, the increasing centrality of patient choice in medical decision-making and the impossibility of drawing and maintaining a sharp distinction between information and advertising. The prohibition is further threatened by recent international trade agreements. These factors make DTCA-PM inevitable and legislative and professional bodies need to acknowledge this to create a more effective health-care policy.

From advance directives to advance care planning: current legal status, ethical rationales and a new research agenda

This paper uses a case example to review the current legal status of advance directives, as well as their ethical rationale. We draw attention to ongoing efforts to institutionalize advance directives, and to some of the tractable and intractable reasons why advance directives are ineffective. We then introduce the concept of advance care planning, and argue that we should not assume that advance care directives have a place in this process. We conclude by offering three reasons why this assumption may operate, and by suggesting that contingency and uncertainty may sometimes overwhelm all rational approaches to medical care.

Towards a dialogical ethics of interprofessionalism

Contemporary medical practice brings a diverse range of professions and disciplines together in greater and closer contact. This situation of increasing complexity and changing professional roles gives rise to multifaceted ethical dilemmas and theoretical and practical concerns. In this essay we argue that for multidisciplinary relationships to be facilitated and to progress towards interdisciplinary teamwork, moral agents have to go beyond orthodox ethical systems and appeal to normative theory. We will argue that conceptualising ethics as a shared social practice may provide a useful starting point. This dialogic approach places greater emphasis on open deliberation and the articulation, negotiation, exploration and generation of new ethical perspectives in the here and now of clinical practice.

Death, dying and donation: organ transplantation and the diagnosis of death

Refusal of organ donation is common, and becoming more frequent. In Australia refusal by families occurred in 56% of cases in 1995 in New South Wales, and had risen to 82% in 1999, becoming the most important determinant of the country's very low organ donation rate (8.9/million in 1999). Leading causes of refusal, identified in many studies, include the lack of understanding by families of brain death and its implications, and subsequent reluctance to relegate the body to purely instrumental status. It is an interesting paradox that surveys of the public continue to show considerable support for organ donation programmes--in theory we will, in practice we won't (and don't). In this paper we propose that the Australian community may, for good reason, distrust the concept of and criteria for "whole brain death", and the equation of this new concept with death of the human being. We suggest that irreversible loss of circulation should be reinstated as the major defining characteristic of death, but that brain-dead, heart-beating entities remain suitable organ donors despite being alive by this criterion. This presents a major challenge to the "dead donor rule", and would require review of current transplantation legislation. Brain dead entities are suitable donors because of irreversible loss of personhood, accurately and robustly defined by the current brain stem criteria. Even the dead are not terminally ill any more.

An ethics core curriculum for Australasian medical Schools

Teaching ethics incorporates teaching of knowledge as well as skills and attitudes. Each of these requires different teaching and assessment methods. A core curriculum of ethics knowledge must address both the foundations of ethics and specific ethical topics. Ethical skills teaching focuses on the development of ethical awareness, moral reasoning, communication and collaborative action skills. Attitudes that are important for medical students to develop include honesty, integrity and trustworthiness, empathy and compassion, respect, and responsibility, as well as critical self-appraisal and commitment to lifelong education.

Advance care planning in residential care

BACKGROUND

To provide optimal care for our ageing population, some form of advance care planning (ACP) is essential. Overseas data suggest that the process of ACP and the use of advance care directives (ACD) is suboptimal in residential care institutions. By comparison there are few Australian data.

AIM

To study the process of ACP and the prevalence of ACD in residential care.

METHODS

Cross-sectional study using a questionnaire in the Hunter area, NSW, Australia.

RESULTS

Very low levels of formal advance directives were found (available for only 0.2%). Only 1.1% of residents had 'no-CPR' orders documented in the medical record, while 5.6% had a formal guardian and 2.8% had an enduring guardian. Informal processes of advance planning were much more prevalent. Sixty-five per cent had a 'person responsible' recorded to make decisions for them while in 13% of cases, there was 'staff consensus' as to the optimal care for the patient. However, in 10.6% there was no clear process for medical decision making identified.

CONCLUSIONS

Advanced directives are infrequently used in residential care. Further qualitative and quantitative studies are warranted to explore current processes of decision making.

Translation of the alzheimer amyloid precursor protein mRNA is up-regulated by interleukin-1 through 5'-untranslated region sequences

The amyloid precursor protein (APP) has been associated with Alzheimer's disease (AD) because APP is processed into the beta-peptide that accumulates in amyloid plaques, and APP gene mutations can cause early onset AD. Inflammation is also associated with AD as exemplified by increased expression of interleukin-1 (IL-1) in microglia in affected areas of the AD brain. Here we demonstrate that IL-1alpha and IL-1beta increase APP synthesis by up to 6-fold in primary human astrocytes and by 15-fold in human astrocytoma cells without changing the steady-state levels of APP mRNA. A 90-nucleotide sequence in the APP gene 5'-untranslated region (5'-UTR) conferred translational regulation by IL-1alpha and IL-1beta to a chloramphenicol acetyltransferase (CAT) reporter gene. Steady-state levels of transfected APP(5'-UTR)/CAT mRNAs were unchanged, whereas both base-line and IL-1-dependent CAT protein synthesis were increased. This APP mRNA translational enhancer maps from +55 to +144 nucleotides from the 5'-cap site and is homologous to related translational control elements in the 5'-UTR of the light and and heavy ferritin genes. Enhanced translation of APP mRNA provides a mechanism by which IL-1 influences the pathogenesis of AD.

Rapid intraoperative facial nerve expansion

The repair of nerve length defect presents a reconstructive challenge after trauma and oncologic resection. This study examined rapid intraoperative nerve expansion as a method of repairing nerve length defects with the cat facial nerve model. We compared expanded nerves with grafted nerves and intact nerves 1 year after repair using the criteria of gross function (symmetry and blink reflex according to a modified House scale), electromyography thresholds, nerve-conduction velocity, morphology, and axon count. Three of the five expanded nerves regenerated, and all of the grafted nerves regenerated. Functional results were similar for the regenerated expanded and the grafted facial nerves, and both methods achieved an equivalent level of function. The facial nerves of the regenerated expanded group, grafted group, and intact group had mean electromyography thresholds of 132 mV, 98 mV, and 134 mV, respectively, and mean conduction velocities of 48.3 mg/second, 47.9 m/second, and 44.7 m/second, respectively. Morphologic examination of all five expanded nerves immediately after the expansion process revealed an intact fascicular structure. However, 1 year after excision of the expanded segment and repair, only three of the five nerves regenerated. Axon count at 1 year was as follows: 404 for the regenerated expanded nerves, 449 for the grafted nerves, and 403 for the intact nerves. The potential advantages of rapid intraoperative nerve expansion over nerve grafting for the repair of nerve gap defects include a single suture line and absence of donor site morbidity. This pilot study demonstrates that rapid intraoperative nerve expansion and regeneration is possible and can be used to repair a nerve length deficit. The development of a rapid and reliable method of intraoperative nerve expansion deserves further study.

Child abuse: a study of the child's perspective

This study ascertained the child's response to various types of abuse and neglect. With interviews and questionnaires for the staff of a child psychiatric unit, the mothers and the children involved, we assessed the severity, frequency and duration of physical abuse, verbal abuse, physical neglect, emotional neglect or sexual abuse of children. The physically abused children accepted blame for mild but not severe mistreatment. Verbally and sexually abused children did not believe it was their fault if the mistreatment was moderately extensive but did if it was mild or severe. The relationship between extent of abuse and blame was less clear for neglect, but children usually though it was their fault. Verbal and sexual abuse appeared to have a greater impact on the children's perception of themselves and the world. Verbally abused children were more angry and more pessimistic about their future. Although physical abuse appeared to make some children feel they were unwanted at birth, how much the mother wanted her children was not related to the extent of any type of abuse. Both the type and extent of mistreatment appear to have different effects on the child's subjective experience. The use of the visual analogue scale in this study made it possible to differentiate a continuum of severity and frequency of five types of mistreatment without the need for definition.

Epidemiologic, clinical, and laboratory features of Coxsackie B1-B5 infections in the United States, 1970-79

In the period 1970 through 1979, the Coxsackie B1, B2, B3, B4, and B5 viruses constituted 24 percent of more than 18,000 enteroviruses isolated and reported through national surveillance. Young children, especially males, were most frequently affected: 48 percent of the national surveillance population were less than 5 years of age, including 30 percent who were less than 1 year old. Among the most frequently reported clinical syndromes associated with B infection were meningitis (in 56 percent of patients with B1-B5 infections), encephalitis (in 15 percent), and respiratory tract disease (in 14 percent). Carditis, a well-known B syndrome, was reported with only 2 percent of B1-B5 infections. Like most enteroviral agents, Group B viruses were isolated primarily during the summer: 87 percent of all these isolations were made during the 5 months from June through October. Although B2, B3, and B4 viruses were isolated at relatively uniform levels each year, B1 and B5 viral illnesses occurred nationwide as explosive epidemics only in certain years. A separate population of B-infected patients, identified by the Nassau County Medical Center (NCMC) Virus Laboratory, East Meadow, N.Y., during the same 10-year period, was studied to compare epidemiologic characteristics and to evaluate in greater detail clinical and laboratory features of B infections. Because of more active solicitation of specimens for testing, ascertainment in the NCMC system was more complete. The most frequently reported clinical findings at NCMC included fever (97 percent of cases), which was biphasic in 27 percent; pharyngitis (85 percent); vomiting (56 percent); headache (49 percent); other respiratory signs and symptoms (44 percent); diarrhea (40 percent); abdominal pain (33 percent); rash (31 percent); and otitis (28 percent). Rash was more frequently associated with younger than with older age groups (P < .01) for all B agents. Overall, throat (T) and rectal (R) swabs had the highest B-positivity rates among known infected patients(83 percent for T and 78 percent for R). Only for T was the positivity rate correlated with the interval between onset of illness and obtaining the specimen (P < .05). B agents grew most quickly from T specimens, but most reliably from R specimens. On the basis of these data,the authors recommend that both T and R specimens be obtained from every patient for whom prompt and reliable laboratory diagnosis of B infection is sought.To the authors' knowledge, these results from 10 years of national surveillance represent the largest surveillance summary of Coxsackie B viruses to date in the literature. Comparison of these results with those reported over the same 10 years by NCMC reflects differences that arise mostly because of differences in ascertainment systems.

Group B coxsackievirus infections in infants younger than three months of age: a serious childhood illness

From 1970 to 1979 the viral laboratory at the Nassau County Medical Center (NCMC) tested 602 culture specimens that were positive for group B coxsackievirus. Eighty-one of the specimens were from hospitalized infants younger than three months of age with nonfatal infection. The case histories of 77 of these infants, whose medical records were available for study, are reviewed here. Aseptic meningitis was the clinical syndrome seen most frequently (48 of 77 patients). Protein levels in cerebrospinal fluid (CSF) did not rise above 170 mg/dl, and in only three infants did the glucose concentration in CSF fall below 30 mg/dl. Infants were febrile for an average of 3.1 days, and no infant had fever of longer than six days' duration. During 1970-1981, eight newborns whose culture specimens were examined at NCMC died of overwhelming group B coxsackievirus disease. The clinical histories of these eight patients and 33 other fatal cases reported in the literature are reviewed. Three patterns of death were observed. Rapid death occurred in 12 patients aged 2-17 days. In 11 patients a diphasic illness led to death at age 8-24 days. In 18 patients a progressive illness was described. Myocarditis was present in all infants. Pulmonary hemorrhage and liver necrosis occurred in 30 and 18 patients, respectively. Jaundice was more frequently observed in fatal cases. Bleeding diatheses were also reported and probably reflect hepatic necrosis. Twenty-four mothers had evidence of a viral-like infection occurring between 10 days antepartum and five days postpartum. Group B coxsackievirus infection must be considered a serious disease of the newborn, which in our community occurred in 77 of 153,250 live births and accounted for six deaths between 1970 and 1979.

Influences on the coiling of the cochlea

The growth and shape of the cochlea appears to be controlled by the formation of the cartilaginous capsule. Coiling of the cochlear duct is apparently the result of the physical barrier and support provided by the cartilage cells differentiating from mesenchyme surrounding the ventral portion of the otocyst. In addition, tissue interactions between this mesenchyme and the developing cochlear duct will influence the formation of the cartilaginous capsule and they may also be the origin of one of the controlling agents for the coiling mechanism.

Development of the cochlea and its coiling mechanism

The growth and shape of the membraneous labyrinth appears to be organized and restricted by the formation of the cartilaginous capsule. Coiling of the cochlear duct appears to be the result of the physical barrier and support provided by the cartilage cells differentiating from mesenchyme surrounding the otocyst. In addition, tissue interactions between this mesenchyme and the developing cochlear duct may be the source of a genetic message for the coiling mechanism.