Protocol for a parallel cluster randomized trial of a participatory tailored approach to reduce overuse of antibiotics at hospital discharge: the ROAD home trial

BACKGROUND

Antibiotic overuse at hospital discharge is common, costly, and harmful. While discharge-specific antibiotic stewardship interventions are effective, they are resource-intensive and often infeasible for hospitals with resource constraints. This weakness impacts generalizability of stewardship interventions and has health equity implications as not all patients have access to the benefits of stewardship based on where they receive care. There may be different pathways to improve discharge antibiotic prescribing that vary widely in feasibility. Supporting hospitals in selecting interventions tailored to their context may be an effective approach to feasibly reduce antibiotic overuse at discharge across diverse hospitals. The objective of this study is to evaluate the effectiveness of the Reducing Overuse of Antibiotics at Discharge Home multicomponent implementation strategy ("ROAD Home") on antibiotic overuse at discharge for community-acquired pneumonia and urinary tract infection.

METHODS

This 4-year two-arm parallel cluster-randomized trial will include three phases: baseline (23 months), intervention (12 months), and postintervention (12 months). Forty hospitals recruited from the Michigan Hospital Medicine Safety Consortium will undergo covariate-constrained randomization with half randomized to the ROAD Home implementation strategy and half to a "stewardship as usual" control. ROAD Home is informed by the integrated-Promoting Action on Research Implementation in Health Services Framework and includes (1) a baseline needs assessment to create a tailored suite of potential stewardship interventions, (2) supported decision-making in selecting interventions to implement, and (3) external facilitation following an implementation blueprint. The primary outcome is baseline-adjusted days of antibiotic overuse at discharge. Secondary outcomes include 30-day patient outcomes and antibiotic-associated adverse events. A mixed-methods concurrent process evaluation will identify contextual factors influencing the implementation of tailored interventions, and assess implementation outcomes including acceptability, feasibility, fidelity, and sustainment.

DISCUSSION

Reducing antibiotic overuse at discharge across hospitals with varied resources requires tailoring of interventions. This trial will assess whether a multicomponent implementation strategy that supports hospitals in selecting evidence-based stewardship interventions tailored to local context leads to reduced overuse of antibiotics at discharge. Knowledge gained during this study could inform future efforts to implement stewardship in diverse hospitals and promote equity in access to the benefits of quality improvement initiatives.

TRIAL REGISTRATION

Clinicaltrials.gov NCT06106204 on 10/30/23.

Development of patient safety measures to identify inappropriate diagnosis of common infections

BACKGROUND

Inappropriate diagnosis of infections results in antibiotic overuse and may delay diagnosis of underlying conditions. Here, we describe the development and characteristics of two safety measures of inappropriate diagnosis of urinary tract infection (UTI) and community-acquired pneumonia (CAP), the most common inpatient infections on general medicine services.

METHODS

Measures were developed from guidelines and literature and adapted based on data from patients hospitalized with UTI and CAP in 49 Michigan hospitals and feedback from end-users, a technical expert panel (TEP), and a patient focus group. Each measure was assessed for reliability, validity, feasibility, and usability.

RESULTS

Two measures, now endorsed by the National Quality Forum (NQF), were developed. Measure reliability (derived from 24,483 patients) was excellent (0.90 for UTI; 0.91 for CAP). Both measures had strong validity demonstrated through a) face validity by hospital users, the TEPs, and patient focus group, b) implicit case review (ĸ 0.72 for UTI; ĸ 0.72 for CAP), and c) rare case misclassification (4% for UTI; 0% for CAP) due to data errors (<2% for UTI; 6.3% for CAP). Measure implementation through hospital peer comparison in Michigan hospitals (2017 to 2020) demonstrated significant decreases in inappropriate diagnosis of UTI and CAP (37% and 32%, respectively, p < 0.001), supporting usability.

CONCLUSIONS

We developed highly reliable, valid, and usable measures of inappropriate diagnosis of UTI and CAP for hospitalized patients. Hospitals seeking to improve diagnostic safety, antibiotic use, and patient care should consider using these measures to reduce inappropriate diagnosis of CAP and UTI.

Excellence in Antibiotic Stewardship: A mixed methods study comparing High, Medium, and Low Performing Hospitals

BACKGROUND

Despite antibiotic stewardship programs existing in most acute care hospitals, there continues to be variation in appropriate antibiotic use. While existing research examines individual prescriber behavior, contextual reasons for variation are poorly understood.

METHODS

We conducted an explanatory, sequential mixed methods study of a purposeful sample of 7 hospitals with varying discharge antibiotic overuse. For each hospital, we conducted surveys, document analysis, and semi-structured interviews with antibiotic stewardship and clinical stakeholders. Data were analyzed separately and mixed during the interpretation phase, where each hospital was examined as a case, with findings organized across cases using a strengths, weaknesses, opportunities, and threats framework to identify factors accounting for differences in antibiotic overuse across hospitals.

RESULTS

Surveys included 85 respondents. Interviews included 90 respondents (31 hospitalists, 33 clinical pharmacists, 14 stewardship leaders, 12 hospital leaders). On surveys, clinical pharmacists at hospitals with lower antibiotic overuse were more likely to report feeling: respected by hospitalist colleagues (p=0.001), considered valuable team members (p=0.001), comfortable recommending antibiotic changes (p=0.02). Based on mixed-methods analysis, hospitals with low antibiotic overuse had four distinguishing characteristics: a) robust knowledge of and access to antibiotic stewardship guidance, b) high quality clinical pharmacist-physician relationships, c) tools and infrastructure to support stewardship, and d) highly engaged Infectious Diseases physicians who advocated stewardship principles.

CONCLUSION

This mixed-method study demonstrates the importance of organizational context for high performance in stewardship and suggests improving antimicrobial stewardship requires attention to knowledge, interactions, and relationships between clinical teams and infrastructure that supports stewardship and team interactions.

Gender differences in COVID-19-related manuscript authorship by hospitalists during the pandemic: A bibliometric analysis

BACKGROUND

Hospital medicine (HM) has a well-described gender disparity related to academic work and promotion. During the COVID-19 pandemic, female authorship across medicine fell further behind historical averages.

OBJECTIVE

Examine how COVID-19 affected the publication gender gap for hospitalists.

DESIGN, SETTINGS, AND PARTICIPANTS

Bibliometric analysis to determine gender and specialty of US-based physician first and last authors of COVID-19 articles published March 1, 2020 to February 28, 2021 in the four highest impact general medical journals and two highest impact HM-specific journals.

MAIN OUTCOME AND MEASURES

We characterized the percentage of all physician authors that were women, the percentage of physician authors that were hospitalists, and the percentage of HM authors that were women. We compared author gender between general medical and HM-specific journals.

RESULTS

During the study period, 853 manuscripts with US-based first or last authors were published in eligible journals. Included manuscripts contained 1124 US-based physician first or last author credits, of which 34.2% (384) were women and 8.8% (99) were hospitalists. Among hospitalist author credits, 43.4% (n = 43/99) were occupied by women. The relative gender equity for hospitalist authors was driven by the two HM journals where, compared to the four general medical journals, hospitalist authors (54.1% [33/61] vs. 26.3% [10/38] women, respectively, p = .002) and hospitalist last authors (51.9% [14/27] vs. 20% [4/20], p = .03) were more likely to be women.

CONCLUSIONS

Across COVID-19-related manuscripts, disparities by gender were driven by the high-impact general medical journals. HM-specific journals had more equitable inclusion of women authors, demonstrating the potential impact of proactive editorial policies on diversity.

Antibiotic Stewardship Strategies and Their Association with Antibiotic Overuse after Hospital Discharge: An Analysis of the Reducing Overuse of Antibiotics at Discharge (Road) Home Framework

Background

Strategies to optimize antibiotic prescribing at discharge are not well understood.

Methods

In fall 2019, we surveyed 39 Michigan hospitals on their antibiotic stewardship strategies. The association of reported strategies with discharge antibiotic overuse (unnecessary, excess, suboptimal fluoroquinolones) for community-acquired pneumonia (CAP) and urinary tract infection (UTI) was evaluated in 2 ways: (1) all strategies assumed equal weight and (2) strategies were weighted based on the ROAD (Reducing Overuse of Antibiotics at Discharge) Home Framework (ie, Tier 1—Critical infrastructure, Tier 2—Broad inpatient interventions, Tier 3—Discharge-specific strategies) with Tier 3 strategies receiving the highest weight.

Results

Between 1 July 2017 and 30 July 2019, 39 hospitals with 20 444 patients (56.5% CAP; 43.5% UTI) were included. Survey response was 100%. Hospitals reported a median (interquartile range [IQR]) 12 (9–14) of 34 possible stewardship strategies. On analyses of individual stewardship strategies, the Tier 3 intervention, review of antibiotics prior to discharge, was the only strategy consistently associated with lower antibiotic overuse at discharge (adjusted incident rate ratio [aIRR] 0.543, 95% confidence interval [CI]: .335–.878). On multivariable analysis, weighting by ROAD Home tier predicted antibiotic overuse at discharge for both CAP and UTI. For diseases combined, having more weighted strategies was associated with lower antibiotic overuse at discharge (aIRR 0.957, 95% CI: .927–.987, per weighted intervention); discharge-specific stewardship strategies were associated with a 12.4% relative decrease in antibiotic overuse days at discharge.

Conclusions

The more stewardship strategies a hospital reported, the lower its antibiotic overuse at discharge. However, Tier 3, or discharge-specific strategies, appeared to have the largest effect on antibiotic prescribing at discharge.

Cigarettes and Straws: Late Positive Potential Modulation in Mental Illness and Nicotine Addiction

Tobacco use remains a major preventable cause of death worldwide, accumulating billions of dollars in healthcare spending annually in the U.S. alone. Evidence has found that among those addicted, individuals suffering with psychiatric illnesses are disproportionally abusing. To assess this disparity, our study observed event related potential (ERP) responses recorded with electroencephalogram (EEG) in chronic smokers with (MI; n=6) and without mental illness (NMI; n=6). We found that the MI group alone presented heightened late positive potential (LPP) responses while processing cigarette (addictive) stimuli compared to neutral images (t-value = 3.11 at Cz, 3.92 at Pz). Our study illustrates the significance of the LPP as a promising biomarker to assess tobacco addiction in individuals facing mental illness.

Non-Invasive, Cost-Effective, Early Diagnosis of Mild Cognitive Impairment in an Outpatient Setting: Pilot Study

Mild cognitive impairment (MCI) and Alzheimer's Disease (AD) affect millions worldwide, yet no curative treatments for these neuro-degenerative disorders have been developed to date. The current study aims to propose a noninvasive, cost-effective, early diagnostic protocol for individuals suffering with MCI in an outpatient setting. Elderly participants (n=11) were screened for MCI utilizing the Montreal Cognitive Assessment (MoCA) questionnaire preceding a visual stimuli task. Participants were presented with facial stimuli to elicit event related potentials (ERP) while their cortical activity was recorded utilizing electroencephalogram (EEG). Combining regional neurophysiological biomarkers into a multidimensional feature space allowed for differentiation between healthy and MCI participants based on their respective MoCA scores. This study illustrates the feasibility of recording reliable EEG in an outpatient setting while presenting a novel method for diagnosing MCI in elderly (age >60) populations.

Propofol for Treatment-Resistant Depression: A Pilot Study

BACKGROUND

We hypothesized that propofol, a unique general anesthetic that engages N-methyl-D-aspartate and gamma-aminobutyric acid receptors, has antidepressant properties. This open-label trial was designed to collect preliminary data regarding the feasibility, tolerability, and efficacy of deep propofol anesthesia for treatment-resistant depression.

METHODS

Ten participants with moderate-to-severe medication-resistant depression (age 18-45 years and otherwise healthy) each received a series of 10 propofol infusions. Propofol was dosed to strongly suppress electroencephalographic activity for 15 minutes. The primary depression outcome was the 24-item Hamilton Depression Rating Scale. Self-rated depression scores were compared with a group of 20 patients who received electroconvulsive therapy.

RESULTS

Propofol treatments were well tolerated by all subjects. No serious adverse events occurred. Montreal Cognitive Assessment scores remained stable. Hamilton scores decreased by a mean of 20 points (range 0-45 points), corresponding to a mean 58% improvement from baseline (range 0-100%). Six of the 10 subjects met the criteria for response (>50% improvement). Self-rated depression improved similarly in the propofol group and electroconvulsive therapy group. Five of the 6 propofol responders remained well for at least 3 months. In posthoc analyses, electroencephalographic measures predicted clinical response to propofol.

CONCLUSIONS

These findings demonstrate that high-dose propofol treatment is feasible and well tolerated by individuals with treatment-resistant depression who are otherwise healthy. Propofol may trigger rapid, durable antidepressant effects similar to electroconvulsive therapy but with fewer side effects. Controlled studies are warranted to further evaluate propofol's antidepressant efficacy and mechanisms of action. ClinicalTrials.gov: NCT02935647.

Gene Expression Factor Analysis to Differentiate Pathways Linked to Fibromyalgia, Chronic Fatigue Syndrome, and Depression in a Diverse Patient Sample

OBJECTIVE

To determine if independent candidate genes can be grouped into meaningful biologic factors, and whether these factors are associated with the diagnosis of chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS), while controlling for comorbid depression, sex, and age.

METHODS

We included leukocyte messenger RNA gene expression from a total of 261 individuals, including healthy controls (n = 61), patients with FMS only (n = 15), with CFS only (n = 33), with comorbid CFS and FMS (n = 79), and with medication-resistant (n = 42) or medication-responsive (n = 31) depression. We used exploratory factor analysis (EFA) on 34 candidate genes to determine factor scores and regression analysis to examine whether these factors were associated with specific diagnoses.

RESULTS

EFA resulted in 4 independent factors with minimal overlap of genes between factors, explaining 51% of the variance. We labeled these factors by function as 1) purinergic and cellular modulators, 2) neuronal growth and immune function, 3) nociception and stress mediators, and 4) energy and mitochondrial function. Regression analysis predicting these biologic factors using FMS, CFS, depression severity, age, and sex revealed that greater expression in factors 1 and 3 was positively associated with CFS and negatively associated with depression severity (Quick Inventory for Depression Symptomatology score), but not associated with FMS.

CONCLUSION

Expression of candidate genes can be grouped into meaningful clusters, and CFS and depression are associated with the same 2 clusters, but in opposite directions, when controlling for comorbid FMS. Given high comorbid disease and interrelationships between biomarkers, EFA may help determine patient subgroups in this population based on gene expression.

Fatigue sensation and gene expression in trained cyclists following a 40 km time trial in the heat

PURPOSE

We examined the effect of race-effort cycling exercise with and without heat stress on post-exercise perceptions of fatigue and pain, as well as mRNA expression in genes related to exercise responses.

METHODS

Trained cyclists (n = 20) completed 40 km time trials during temperate (TC, 21 °C) and hot (HC, 35 °C) conditions. Blood lactates were measured 1 and 5 min post-exercise. Venous blood samples and ratings of fatigue and pain perceptions were obtained at baseline and at 0.5, 8, 24, and 48 h post-exercise. Leukocyte mRNA expression was performed for metabolite detecting, adrenergic, monoamine, and immune receptors using qPCR.

RESULTS

Significantly lower mean power (157 ± 32.3 vs 187 ± 40 W) and lactates (6.4 ± 1.7 vs 8.8 ± 3.2 and 4.2 ± 1.5 vs 6.6 ± 2.7 mmol L(-1) at 1- and 5-min post-exercise) were observed for HC versus TC, respectively (p < 0.05). Increases (p < 0.05) in physical fatigue and pain perception during TTs did not differ between TC and HC (p > 0.30). Both trials resulted in significant post-exercise decreases in metabolite detecting receptors ASIC3, P2X4, TRPV1, and TRPV4; increases in adrenergic receptors α2a, α2c, and β1; decreases in adrenergic β2, the immune receptor TLR4, and dopamine (DRD4); and increases in serotonin (HTR1D) and IL-10 (p < 0.05). Post-exercise IL-6 differed between TC and HC, with significantly greater increases observed following HC (p < 0.05).

CONCLUSIONS

Both TT performances appeared to be regulated around a specific sensory perception of fatigue and pain. Heat stress may have compensated for lower lactate during HC, thereby matching changes in metabolite detecting and other mRNAs across conditions.

Resistance strength training exercise in children with spinal muscular atrophy

INTRODUCTION

Preliminary evidence in adults with spinal muscular atrophy (SMA) and in SMA animal models suggests exercise has potential benefits in improving or stabilizing muscle strength and motor function.

METHODS

We evaluated feasibility, safety, and effects on strength and motor function of a home-based, supervised progressive resistance strength training exercise program in children with SMA types II and III. Up to 14 bilateral proximal muscles were exercised 3 times weekly for 12 weeks.

RESULTS

Nine children with SMA, aged 10.4 ± 3.8 years, completed the resistance training exercise program. Ninety percent of visits occurred per protocol. Training sessions were pain-free (99.8%), and no study-related adverse events occurred. Trends in improved strength and motor function were observed.

CONCLUSIONS

A 12-week supervised, home-based, 3-day/week progressive resistance training exercise program is feasible, safe, and well tolerated in children with SMA. These findings can inform future studies of exercise in SMA.

Dysregulation of leukocyte gene expression in women with medication-refractory depression versus healthy non-depressed controls

BACKGROUND

Depressive Disorders (DD) are a great financial and social burden. Females display 70% higher rate of depression than males and more than 30% of these patients do not respond to conventional medications. Thus medication-refractory female patients are a large, under-served, group where new biological targets for intervention are greatly needed.

METHODS

We used real-time quantitative polymerase chain reaction (qPCR) to evaluate mRNA gene expression from peripheral blood leukocytes for 27 genes, including immune, HPA-axis, ion channels, and growth and transcription factors. Our sample included 23 females with medication refractory DD: 13 with major depressive disorder (MDD), 10 with bipolar disorder (BPD). Our comparison group was 19 healthy, non-depressed female controls. We examined differences in mRNA expression in DD vs. controls, in MDD vs. BPD, and in patients with greater vs. lesser depression severity.

RESULTS

DD patients showed increased expression for IL-10, IL-6, OXTR, P2RX7, P2RY1, and TRPV1. BPD patients showed increased APP, CREB1, NFKB1, NR3C1, and SPARC and decreased TNF expression. Depression severity was related to increased IL-10, P2RY1, P2RX1, and TRPV4 expression.

CONCLUSIONS

These results support prior findings of dysregulation in immune genes, and provide preliminary evidence of dysregulation in purinergic and other ion channels in females with medication-refractory depression, and in transcription and growth factors in those with BPD. If replicated in future research examining protein levels as well as mRNA, these pathways could potentially be used to explore biological mechanisms of depression and to develop new drug targets.

Exogenously applied muscle metabolites synergistically evoke sensations of muscle fatigue and pain in human subjects

NEW FINDINGS

What is the central question of this study? Can physiological concentrations of metabolite combinations evoke sensations of fatigue and pain when injected into skeletal muscle? If so, what sensations are evoked? What is the main finding and its importance? Low concentrations of protons, lactate and ATP evoked sensations related to fatigue. Higher concentrations of these metabolites evoked pain. Single metabolites evoked no sensations. This suggests that the combination of an ASIC receptor and a purinergic P2X receptor is required for signalling fatigue and pain. The results also suggest that two types of sensory neurons encode metabolites; one detects low concentrations of metabolites and signals sensations of fatigue, whereas the other detects higher levels of metabolites and signals ache and hot. The perception of fatigue is common in many disease states; however, the mechanisms of sensory muscle fatigue are not understood. In mice, rats and cats, muscle afferents signal metabolite production in skeletal muscle using a complex of ASIC, P2X and TRPV1 receptors. Endogenous muscle agonists for these receptors are combinations of protons, lactate and ATP. Here we applied physiological concentrations of these agonists to muscle interstitium in human subjects to determine whether this combination could activate sensations and, if so, to determine how the subjects described these sensations. Ten volunteers received infusions (0.2 ml over 30 s) containing protons, lactate and ATP under the fascia of a thumb muscle, abductor pollicis brevis. Infusion of individual metabolites at maximal amounts evoked no fatigue or pain. Metabolite combinations found in resting muscles (pH 7.4 + 300 nm ATP + 1 mm lactate) also evoked no sensation. The infusion of a metabolite combination found in muscle during moderate endurance exercise (pH 7.3 + 400 nm ATP + 5 mm lactate) produced significant fatigue sensations. Infusion of a metabolite combination associated with vigorous exercise (pH 7.2 + 500 nm ATP + 10 mm lactate) produced stronger sensations of fatigue and some ache. Higher levels of metabolites (as found with ischaemic exercise) caused more ache but no additional fatigue sensation. Thus, in a dose-dependent manner, intramuscular infusion of combinations of protons, lactate and ATP leads to fatigue sensation and eventually pain, probably through activation of ASIC, P2X and TRPV1 receptors. This is the first demonstration in humans that metabolites normally produced by exercise act in combination to activate sensory neurons that signal sensations of fatigue and muscle pain.

Antidepressant and neurocognitive effects of isoflurane anesthesia versus electroconvulsive therapy in refractory depression

Background

Many patients have serious depression that is nonresponsive to medications, but refuse electroconvulsive therapy (ECT). Early research suggested that isoflurane anesthesia may be an effective alternative to ECT. Subsequent studies altered drug, dose or number of treatments, and failed to replicate this success, halting research on isoflurane's antidepressant effects for a decade. Our aim was to re-examine whether isoflurane has antidepressant effects comparable to ECT, with less adverse effects on cognition.

Method

Patients with medication-refractory depression received an average of 10 treatments of bifrontal ECT (n = 20) or isoflurane (n = 8) over 3 weeks. Depression severity (Hamilton Rating Scale for Depression-24) and neurocognitive responses (anterograde and retrograde memory, processing speed and verbal fluency) were assessed at Pretreatment, Post all treatments and 4-week Follow-up.

Results

Both treatments produced significant reductions in depression scores at Post-treatment and 4-week Follow-up; however, ECT had modestly better antidepressant effect at follow-up in severity-matched patients. Immediately Post-treatment, ECT (but not isoflurane) patients showed declines in memory, fluency, and processing speed. At Follow-up, only autobiographical memory remained below Pretreatment level for ECT patients, but isoflurane patients had greater test-retest neurocognitive score improvement.

Conclusions

Our data reconfirm that isoflurane has an antidepressant effect approaching ECT with less adverse neurocognitive effects, and reinforce the need for a larger clinical trial.

Effect of passive whole body heating on central conduction and cortical excitability in multiple sclerosis patients and healthy controls

Heat stress is associated with increased fatigue perception and decrements in function for individuals with multiple sclerosis (MS). Similarly, healthy individuals experience decrements in exercise performance during hyperthermia. Alterations in central nervous system (CNS) function during hyperthermia include reduced voluntary activation of muscle and increased effort perception. The purpose of this investigation was to test the hypothesis that passive heat exposure in MS patients will produce increased subjective fatigue and impairments in physiological measures of central conduction and cortical excitability compared with healthy individuals. Eleven healthy individuals and 11 MS patients completed a series of transcranial magnetic stimulation studies to examine central conduction and cortical excitability under thermoneutral and heat-stressed (HS) conditions at rest and after a fatiguing thumb abduction task. Passive heat stress resulted in significantly greater fatigue perception and impairments in force production in MS patients. Central motor conduction time was significantly shorter during HS in controls; however, in MS patients normal increases in conduction velocity with increased temperature were not observed centrally. MS patients also exhibited decreased cortical excitability during HS, evidenced by significant increases in resting motor threshold, decreased MEP amplitude, and decreased recruitment curve slope. Both groups exhibited postexercise depression of MEP amplitude, but the magnitude of these decrements was amplified in MS patients during HS. Taken together, these results suggest that CNS pathology in MS patients played a substantial role in reducing cortical excitability during HS.

Gene expression alterations at baseline and following moderate exercise in patients with Chronic Fatigue Syndrome and Fibromyalgia Syndrome

OBJECTIVES

To determine mRNA expression differences in genes involved in signalling and modulating sensory fatigue, and muscle pain in patients with chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FM) at baseline, and following moderate exercise.

DESIGN

Forty-eight patients with CFS only, or CFS with comorbid FM, 18 patients with FM that did not meet criteria for CFS, and 49 healthy controls underwent moderate exercise (25 min at 70% maximum age-predicted heart rate). Visual-analogue measures of fatigue and pain were taken before, during and after exercise. Blood samples were taken before and 0.5, 8, 24 and 48 h after exercise. Leucocytes were immediately isolated from blood, number coded for blind processing and analyses and flash frozen. Using real-time, quantitative PCR, the amount of mRNA for 13 genes (relative to control genes) involved in sensory, adrenergic and immune functions was compared between groups at baseline and following exercise. Changes in amounts of mRNA were correlated with behavioural measures and functional clinical assessments.

RESULTS

No gene expression changes occurred following exercise in controls. In 71% of patients with CFS, moderate exercise increased most sensory and adrenergic receptor's and one cytokine gene's transcription for 48 h. These postexercise increases correlated with behavioural measures of fatigue and pain. In contrast, for the other 29% of patients with CFS, adrenergic α-2A receptor's transcription was decreased at all time-points after exercise; other genes were not altered. History of orthostatic intolerance was significantly more common in the α-2A decrease subgroup. FM-only patients showed no postexercise alterations in gene expression, but their pre-exercise baseline mRNA for two sensory ion channels and one cytokine were significantly higher than controls.

CONCLUSIONS

  At least two subgroups of patients with CFS can be identified by gene expression changes following exercise. The larger subgroup showed increases in mRNA for sensory and adrenergic receptors and a cytokine. The smaller subgroup contained most of the patients with CFS with orthostatic intolerance, showed no postexercise increases in any gene and was defined by decreases in mRNA for α-2A. FM-only patients can be identified by baseline increases in three genes. Postexercise increases for four genes meet published criteria as an objective biomarker for CFS and could be useful in guiding treatment selection for different subgroups.

Thermoregulation in multiple sclerosis

Multiple sclerosis (MS) is a progressive neurological disorder that disrupts axonal myelin in the central nervous system. Demyelination produces alterations in saltatory conduction, slowed conduction velocity, and a predisposition to conduction block. An estimated 60-80% of MS patients experience temporary worsening of clinical signs and neurological symptoms with heat exposure. Additionally, MS may produce impaired neural control of autonomic and endocrine functions. This review focuses on five main themes regarding the current understanding of thermoregulatory dysfunction in MS: 1) heat sensitivity; 2) central regulation of body temperature; 3) thermoregulatory effector responses; 4) heat-induced fatigue; and 5) countermeasures to improve or maintain function during thermal stress. Heat sensitivity in MS is related to the detrimental effects of increased temperature on action potential propagation in demyelinated axons, resulting in conduction slowing and/or block, which can be quantitatively characterized using precise measurements of ocular movements. MS lesions can also occur in areas of the brain responsible for the control and regulation of body temperature and thermoregulatory effector responses, resulting in impaired neural control of sudomotor pathways or neural-induced changes in eccrine sweat glands, as evidenced by observations of reduced sweating responses in MS patients. Fatigue during thermal stress is common in MS and results in decreased motor function and increased symptomatology likely due to impairments in central conduction. Although not comprehensive, some evidence exists concerning treatments (cooling, precooling, and pharmacological) for the MS patient to preserve function and decrease symptom worsening during heat stress.

Severity of symptom flare after moderate exercise is linked to cytokine activity in chronic fatigue syndrome

Chronic fatigue syndrome (CFS) patients often report symptom flare (SF) for >24 h after moderate exercise (post-ex). We hypothesized that SF is linked to increases in circulating cytokines and CD40 Ligand (CD40L). In 19 CFS patients and 17 controls, mental and physical fatigue and pain symptom ratings were obtained together with serum for 11 cytokines and CD40L before and at 0.5, 8, 24, and 48 h post-ex. Before exercise, CFS had lower CD40L (p<.05) but similar cytokines versus controls. In subgroups based on SF at 48 h, high SF patients (n=11) increased in IL-1beta, IL-12, IL-6, IL-8, IL-10, and IL-13 (p<.05) 8 h post-ex. Low SF patients (n=8) showed post-ex decreases in IL-10, IL-13, and CD40L, and controls decreased in IL-10, CD40L, and TNFalpha (p<.05). Thus, in CFS, cytokine activity may vary directly with SF, which may explain prior inconsistent findings.

Moderate exercise increases expression for sensory, adrenergic, and immune genes in chronic fatigue syndrome patients but not in normal subjects

Chronic fatigue syndrome (CFS) is characterized by debilitating fatigue, often accompanied by widespread muscle pain that meets criteria for fibromyalgia syndrome (FMS). Symptoms become markedly worse after exercise. Previous studies implicated dysregulation of the sympathetic nervous system (SNS), and immune system (IS) in CFS and FMS. We recently demonstrated that acid sensing ion channel (probably ASIC3), purinergic type 2X receptors (probably P2X4 and P2X5) and the transient receptor potential vanilloid type 1 (TRPV1) are molecular receptors in mouse sensory neurons detecting metabolites that cause acute muscle pain and possibly muscle fatigue. These molecular receptors are found on human leukocytes along with SNS and IS genes. Real-time, quantitative PCR showed that 19 CFS patients had lower expression of beta-2 adrenergic receptors but otherwise did not differ from 16 control subjects before exercise. After a sustained moderate exercise test, CFS patients showed greater increases than control subjects in gene expression for metabolite detecting receptors ASIC3, P2X4, and P2X5, for SNS receptors alpha-2A, beta-1, beta-2, and COMT and IS genes for IL10 and TLR4 lasting from 0.5 to 48 hours (P < .05). These increases were also seen in the CFS subgroup with comorbid FMS and were highly correlated with symptoms of physical fatigue, mental fatigue, and pain. These new findings suggest dysregulation of metabolite detecting receptors as well as SNS and IS in CFS and CFS-FMS.

PERSPECTIVE

Muscle fatigue and pain are major symptoms of CFS. After moderate exercise, CFS and CFS-FMS patients show enhanced gene expression for receptors detecting muscle metabolites and for SNS and IS, which correlate with these symptoms. These findings suggest possible new causes, points for intervention, and objective biomarkers for these disorders.

Brain activation in multiple sclerosis: a BOLD fMRI study of the effects of fatiguing hand exercise

Background

Multiple sclerosis (MS) patients experience fatigue as a chronic symptom that decreases quality of life. Commonly, fatigue in MS patients is manifested as decreased motor function during or after physical activity and is associated with changes in brain metabolism.

Objective

To determine brain activation patterns in MS patients and healthy controls during a simple motor task before and after fatiguing hand-grip exercise.

Methods

Functional magnetic resonance imaging (fMRI) scans were conducted on 10 MS patients and 13 healthy controls during 4-finger flexion and extension in rested and fatigued states.

Results

Before the fatigue protocol, MS patients had greater activation in the contralateral primary motor cortex, insula, and cingulate gyrus than controls. Following fatiguing exercise, controls showed increased activation of precentral gyrus and insula while patients did not show any activation increases and actually decreased activity to the insula.

Conclusion

Results indicate that before fatiguing exercise, MS patients marshaled more brain activation compared to controls, which may represent functionally adaptive changes in response to demyelination. This increased activation may suggest that patients require more effort to perform even simple motor tasks, possibly because peripheral or central signals for fatigue are chronically enhanced. When fatigued further by muscle contraction, brain activation cannot be further increased.

Adjustment for gas exchange threshold enhances precision of heart rate-derived VO2 estimates during heavy exercise

Overestimates of oxygen uptake (VO2) are derived from the heart rate reserve – VO2 reserve (HRR–VO2R) model. We tested the hypothesis that adjusting for differences above and below gas exchange threshold (HRR–GET model) would tighten the precision of HR-derived VO2 estimates during heavy exercise. Seven men and 7 women of various VO2 max levels, on 2 separate days, cycled for 6 min at intensities equal to power at GET, 15% the difference between GET and VO2 max (15% above), and at 30% above GET. A second bout at 15% above GET (15% above (bout 2)) after 3 min of recovery was performed to assess estimates during interval training. Actual VO2 was compared with estimates derived from the HRR–VO2R and the HRR–GET. VO2 values were summed over the 6 min duration of data collection (6 min LO2) and compared with Bland–Altman plots. HRR–VO2R yielded 6 min LO2 (±2 SD) overestimates of 2.0 (±2.5), 1.9 (±2.7), and 1.3 (±3.3) for GET, 15% over, and 30% over, respectively, whereas corresponding 6 min LO2 difference values for the HRR–GET model were –0.42 (±1.6), –0.23 (±1.1), and –0.55 (±1.8), respectively. For 15% above (bout 2), the 6 min LO2 difference for HRR–VO2R was 1.8 (±2.9), whereas the difference for HRR–GET was 0.17 (±1.4). The 6 min LO2 values relative to the subjects’ VO2 max did not vary (r = 0.05 to 0.36); therefore, fitness level did not affect estimates. Sex did not affect accuracy of either estimate model (sex X estimate model interaction, p > 0.95). We observed accurate estimates from the HRR–GET model during heavy exercise.

Eccentric strain at long muscle length evokes the repeated bout effect

The repeated bout effect (RBE) is a phenomenon characterized by less delayed onset muscle soreness (DOMS) and torque deficit after the second of 2 separate eccentric exercise bouts. Previous investigators have reported that shifting of optimum angle after an initial bout of eccentric exercise mediates the RBE. We hypothesized that an RBE for elbow extensor exercise occurs after an initial bout performed at long (starting position of 50 degrees to an end position of 130 degrees) but not short (starting position of 0 degrees to an end position of 80 degrees) muscle length because strain at long length evokes a shifting of the optimum angle to a longer length. Untrained women performed an initial bout at either long or short length (n = 9 per group) followed 1 week later by a repeated bout (RB) through the full ROM (0-130 degrees). Extensor torque and optimum angle was evaluated before, immediately after, and 2 days after each bout. A mechanical transducer depressed on the triceps brachii quantified DOMS. Torque deficits were 3% and 7% after exercise at short vs. long length, respectively. Two days after the RB, torque deficit was 8% and 1% for those previously exercising at short vs. long length (group x bout, p < 0.05). Greater DOMS (N) was observed after exercise at long (16 +/- 3) vs. short (23 +/- 2) length; whereas greater DOMS occurred for the short-length (17 +/- 2) vs. long (26 +/- 3) group after the RB (group x bout, p < 0.05). Optimum angle shifted to a longer length after exercise at long (+10 +/- 4 degrees) vs. short (+1 +/- 3 degrees) length (group x bout, p < 0.05). After the RB, those exercising previously at short length experienced a shift of +15 +/- 4 degrees (main effect, p < 0.05). The findings of this study indicate that the repetitive strain at long but not short muscle length evokes both immediate and sustained shifts in optimum angle to longer lengths, and that this shifting mediates (r(2) = 0.71) the RBE.

Pilocarpine-induced sweat gland function in individuals with multiple sclerosis

This investigation tested the hypothesis that cholinergic sweat function of individuals with multiple sclerosis (MS) (MS-Con; n = 10) is diminished relative to matched healthy control subjects (Con; n = 10). In addition, cholinergic sweat function was determined before and after 15 wk of aerobic training in a subgroup of individuals with MS (MS-Ex; n = 7). Cholinergic sweating responses were assessed via pilocarpine iontophoresis on ventral forearm skin. A collection disk placed over the stimulated area collected sweat for 15 min. Sweat rate (SR) was calculated by dividing sweat collector volume by collection area and time. Iodine-treated paper was applied to the stimulated area to measure number of activated sweat glands (ASG). Sweat gland output (SGO) was calculated by dividing SR by density of glands under the collector. Sweat gland function was determined in MS-Ex to test the hypothesis that exercise training would increase sweating responses. No differences in ASG were observed between MS-Con and Con. SR and SGO in MS-Con [0.18 mg·cm−2·min−1(SD 0.08); 1.74 μg·gland−1·min−1(SD 0.79), respectively] were significantly lower ( P ≤ 0.05) than in Con [0.27 mg·cm−2·min−1(SD 0.10); 2.43 μg·gland−1·min−1(SD 0.69)]. Aerobic exercise training significantly ( P ≤ 0.05) increased peak aerobic capacity in MS-Ex [1.86 (SD 0.75) vs. 2.10 (SD 0.67) l/min] with no changes in ASG, SR, and SGO. Sweat gland function in individuals with MS is impaired relative to healthy controls. Fifteen weeks of aerobic training did not increase stimulated sweating responses in individuals with MS. Diminished peripheral sweating responses may be a consequence of impairments in autonomic control of sudomotor function.

Treatment of multiple sclerosis with an anti-interleukin-2 receptor monoclonal antibody

We examined whether treatment with daclizumab, a humanized monoclonal antibody specific for the interleukin-2 receptor alpha chain, was safe and efficacious in relapsing-remitting and secondary progressive multiple sclerosis patients. Nineteen ambulatory patients with clinically active disease were treated for 5 to 25 months. Seventeen patients were not responding to other immunotherapies. Daclizumab was generally well tolerated. Sustained clinical improvement (10 patients) or stabilization (9 patients) was observed. Daclizumab treatment produced significant reduction in magnetic resonance imaging activity.

Physiological measures of therapeutic response to interferon beta-1a treatment in remitting-relapsing MS

OBJECTIVE

This pilot study was designed to determine the effects of interferon beta-1a (IFNB) therapy (Avonex) on cortically evoked motor potentials (MEPs) during resting and fatigued states in individuals with multiple sclerosis (MS).

METHODS

Eight women with relapsing-remitting MS (mean age 36) and mean Expanded Disability Status Scale (EDSS) score of 3.1 were evaluated before and after 3, 6, and 12 months of IFNB therapy. At each test period, MEPs were recorded at rest and following a fatigue paradigm (3 min maximal contraction). Effects of IFNB on neurological and functional (7.7 m walk and 10 s finger tapping) status and fatigue were also examined.

RESULTS

Recovery from post-exercise depression of MEP amplitudes (PED) was 41, 43, and 43.5% faster at 3, 6, and 12 months, respectively, compared to baseline (P < 0.05). Percent reduction of MEP amplitude was significantly less at 6 months (P < 0.05) The majority of subjects (5/8 at 3 months; 6/8 at 6 and 12 months) reported decreased physical fatigue. Functional improvements were observed for walk and finger tapping scores after 3 months of IFNB treatment. MEP latencies were unchanged over the course of the intervention.

CONCLUSIONS

Results indicate that IFNB therapy may improve the rate of recovery from central fatigue.

SIGNIFICANCE

Transcranial magnetic stimulation (TMS) may have promise as an objective physiological tool to evaluate disease activity and treatment responses in MS.

Metabolic, thermoregulatory, and perceptual responses during exercise after lower vs. whole body precooling

The purpose of this investigation was to compare the thermoregulatory, metabolic, and perceptual effects of lower body (LBI) and whole body (WBI) immersion precooling techniques during submaximal exercise. Eleven healthy men completed two 30-min cycling bouts at 60% of maximal O(2) uptake preceded by immersion to the suprailiac crest (LBI) or clavicle (WBI) in 20 degrees C water. WBI produced significantly lower rectal temperature (T(re)) during minutes 24-30 of immersion and lower T(re), mean skin temperature, and mean body temperature for the first 24, 14, and 16 min of exercise, respectively. Body heat storage rates differed significantly for LBI and WBI during immersion and exercise, although no net differences were observed between conditions. For WBI, metabolic heat production and heart rate were significantly higher during immersion but not during exercise. Thermal sensation was significantly lower (felt colder) and thermal discomfort was significantly higher (less comfortable) for WBI during immersion and exercise. In conclusion, WBI and LBI attenuated T(re) increases during submaximal exercise and produced similar net heat storage over the protocol. LBI minimized metabolic increases and negative perceptual effects associated with WBI.

Thermal regulatory responses to submaximal cycling following lower-body cooling in humans

This study compared the effects of pre-exercise cooling with control water immersions on exercise-induced thermal loads derived from steady-state submaximal exercise. Eight healthy male participants [mean (SEM) age 29 (1) years, maximal oxygen uptake 3.81 (0.74) l x min(-1), and body surface area 1.85 (0.11) m(2)] took part in experiments that included 30 min of baseline data collection [ambient temperature 21.3 (0.2 degrees C)], 30 min of immersion in water to the level of the supra-iliac crest [water temperatures of 35.1 (0.3) degrees C for thermoneutral and 17.7 (0.5) degrees C for precooled treatments], and 60 min of cycling exercise at 60% of maximal oxygen uptake. No significant differences were noted during exercise in net mechanical efficiency, metabolic rate, O(2) pulse, or ratings of perceived exertion between the two treatments. Precooling resulted in a significant negative body heat storage during immersion and allowed greater heat storage during exercise. However, net body heat storage for the entire protocol was no different between treatments. Cooling significantly lowered rectal, mean skin, and mean body temperatures as well as more than doubling the exercise time until a 0.5 degrees C rectal temperature increase was observed. The cooling trial significantly delayed onset of sweating by 19.62 min and decreased sweat rate by 255 ml x h(-1) compared to control. Thermal and sweat sensation scores were lower after the cooling treatment compared to control. These data suggest that lower-body precooling is effective at decreasing body heat storage prior to exercise and decreases reliance on heat dissipation mechanisms during exercise. Therefore, this unique, well-tolerated cooling treatment should have a broader application than other precooling treatments.

Motor-evoked potentials in response to fatiguing grip exercise in multiple sclerosis patients

OBJECTIVE

This study examined central and peripheral effects of fatiguing exercise (3 min maximal grip) in healthy controls (n=10) and multiple sclerosis (MS) subjects with weakness, MS-W (n=16) and normal motor function, MS-NM (n=16) in the studied extremity.

METHOD

Transcranial magnetic stimulation (TMS) was used to assess resting and facilitated motor-evoked potentials (MEPs) of abductor pollicus brevis (APB) and flexor carpi radialis (FCR) muscles before and after fatiguing exercise. Exercise-induced depletion and recovery of phosphocreatine (PCr) were measured using (31)P magnetic resonance spectroscopy ((31)PMRS) in FCR.

RESULTS AND CONCLUSION

MS subjects demonstrated significantly lower peak force and a faster decline in force than controls. Contralateral muscle activation (hand grip) before the fatigue protocol resulted in significantly increased MEP amplitudes in all groups. Contralateral hand grip following fatiguing exercise resulted in significantly higher MEP amplitudes in controls and MS-NM subjects, but not MS-W subjects. Fatiguing exercise resulted in prolonged central motor conduction time (CMCT) in MS subjects, but not controls. No group differences in PCr depletion or resynthesis were observed. All groups demonstrated significant post-exercise depression (PED) of MEP amplitude that persisted beyond the time course of PCr recovery, indicating fatigue was central in origin. MS subjects were less able than controls to increase cortical excitability using contralateral muscle activation following fatiguing exercise, possibly indicating impaired conduction in the corpus callosum.

Effect of precooling on physical performance in multiple sclerosis

Many individuals with MS experience heat sensitivity that may be associated with transient increases in the frequency of clinical signs and symptoms. Although physical activity may be beneficial for those with MS, induced thermal loads may preclude participation in exercise and other daily activities. This project was designed to evaluate the effects of precooling on physical function. Six thermosensitive MS patients were studied. Participants performed a graded exercise test to determine maximal oxygen uptake (VO2max) on a combined arm-leg ergometer. Thermal load was induced by 30 min of exercise under noncooled and precooled conditions at a workrate corresponding to 60% VO2max. Precooling consisted of 30 min lower body immersion in 16 - 17 degrees C water. Fatigue and 25-ft walk performance were assessed before, immediately after, and 30 min following exercise. No treatment differences in VO2 were observed. Rectal temperature, heart rate, and rating of perceived exertion (RPE) were significantly lower during the precooled exercise trial compared to the noncooled trial. Immediately following exercise, 25-ft walk performance and fatigue scores showed significantly greater deterioration in the noncooled condition. Precooling was effective in preventing gains in core temperature with physical work and may allow heat-sensitive individuals with MS to exercise with greater physical comfort.

Recommendations for physical activity in patients with multiple sclerosis

For many years, patients with multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system, have been advised to avoid exercise. MS is believed to be autoimmune in origin, mediated by activated T cells which penetrate the blood-brain barrier and attack myelin. The pathophysiology, with respect to function is an impairment of saltatory conduction, specifically, slowing of conduction speed and/or conduction block. Symptoms can temporarily worsen on exposure to heat or during physical exercise. Exercise programmes must be designed to activate working muscles but avoid overload that results in conduction block. Fatigue, often severe, affects about 85% of MS patients and, along with motor and sensory symptoms, results in decreased mobility and reduced quality of life. Physical activity and recreation are reduced in patients with MS. Before developing recommendations, physical activity patterns and the physical effects of MS should be assessed in individual patients. Patients may then be functionally classified. Physical activity can also be classified in a pyramid structure, with the most basic functions forming the base and the most integrated functions on top. The muscular fitness pyramid progresses through passive range of motion, active resistive, specific strengthening and integrated strength exercises Overall physical activity may be increased according to functional level by performing activities of daily living, incorporating inefficiencies into daily living, pursuing more active recreation and eventually developing a structured exercise programme. The importance of the proper exercise environment, balance and coordination issues and factors related to adherence are discussed.

The physiological effects of beverage ingestion during cross country ski training in elite collegiate skiers

The purpose of this study was to investigate the effects of beverage ingestion on fluid balance during 1.5 hr of low intensity cross country skiing. In Part I, 6 skiers drank water ad libitum during ski training. In Part II, 10 skiers were matched by body weight (BW) and assigned to ingest 2.5 ml.kg-1 BW of water or a carbohydrate/electrolyte (CE) beverage every 2.5 km. Skiing speed averaged 11.5 km.hr-1 for 90 min around a 5 km groomed track. Following 20 min of seated rest, blood samples were collected immediately before and approximately 30 min after skiing. Part I data indicated that subjects ingested 576 +/- 189 ml of fluid and produced 266 +/- 205 ml of urine; BW, plasma and urine osmolality, and plasma protein decreased significantly. In Part II, the CE group produced less urine (135u75 vs. 450 +/- 262 ml) and had smaller decreases in plasma osmolality (-1.0 +/- 1.0 vs. -7.0 +/- 2.4 mOsm.kg H2O) and protein (-0.11 +/- 08 vs. -0.42 +/- 0.24 gL-1) than the water group. No differences were observed for BW loss, % change in PV, FWC, or change in urine osmolality. It was concluded that ad lib water ingestion was inadequate to minimize fluid balance disruption. Plain water ingestion also led to significant dilution of the plasma and increased urine output. However, the ingestion of CE led to attenuation of fluid balance disruption, presumably due to the maintenance of osmotic balance in the plasma.

Impact of aerobic training on fitness and quality of life in multiple sclerosis

Fifty-four multiple sclerosis (MS) patients were randomly assigned to exercise (EX) or nonexercise (NEX) groups. Before and after 15 weeks of aerobic training, aspects of fitness including maximal aerobic capacity (VO2max), isometric strength, body composition, and blood lipids were measured. Daily activities, mood, fatigue, and disease status were measured by the Profile of Mood States (POMS), Sickness Impact Profile (SIP), Fatigue Severity Scale (FSS), and neurological examination. Training consisted of 3 x 40-minute sessions per week of combined arm and leg ergometry. Expanded Disability Status Scale (EDSS) scores were unchanged, except for improved bowel and bladder function in the EX group. Compared with baseline, the EX group demonstrated significant increases in VO2max, upper and lower extremity strength, and significant decreases in skinfolds, triglyceride, and very-low-density lipoprotein (VLDL). For the EX group, POMS depression and anger scores were significantly reduced at weeks 5 and 10, and fatigue was reduced at week 10. The EX group improved significantly on all components of the physical dimension of the SIP and showed significant improvements for social interaction, emotional behavior, home management, total SIP score, and recreation and past times. No changes were observed for EX or NEX groups on the FSS. Exercise training resulted in improved fitness and had a positive impact on factors related to quality of life.

Physiological aspects and injury in elite Alpine skiers

Alpine skiing requires aerobic and anaerobic power, muscular strength, and a variety of complex motor abilities including quickness, agility, balance and coordination. There is evidence of variability in physical characteristics between skiers of different events. Generally, successful alpine competitors are taller and heavier than in the past. Greater size, specifically lean mass, may be related to technique changes because of the advent of breakaway poles. Aerobic power, although important, does not discriminate competitors of varying ability categories. Aerobic power is more likely to be a result of conditioning for alpine skiing rather than a profound requirement of the sport. Anaerobic power is important for skiing and both laboratory and field power tests correlate well with performance. Tests that measure explosive and sustained anaerobic power such as the Wingate, vertical jump, 60-second repeated jump, and Margaria-Kalamen stair run are valuable in assessing skiers. On-snow lactate and oxygen consumption measurements further substantiate the need for high anaerobic power. Alpine skiers have very high leg strength compared with other athletes. Isokinetic testing has been used to evaluate dynamic leg strength in skiers, but little is known about high speed dynamic or eccentric strength capabilities. A new mechanism of knee injury that is associated with tibial acceleration has been identified in competitive alpine skiers. A release binding that is sensitive to physiological factors in addition to release forces should be developed. Strength profiling of skiers may also be valuable in evaluating injury risk.

Human infection by genetically diverse SIVSM-related HIV-2 in west Africa

Our understanding of the biology and origins of human immunodeficiency virus type 2 (HIV-2) derives from studies of cultured isolates from urban populations experiencing epidemic infection and disease. To test the hypothesis that such isolates might represent only a subset of a larger, genetically more diverse group of viruses, we used nested polymerase chain reactions to characterize HIV-2 sequences in uncultured mononuclear blood cells of two healthy Liberian agricultural workers, from whom virus isolation was repeatedly unsuccessful, and from a culture-positive symptomatic urban dweller. Analysis of pol, env and long terminal repeat regions revealed the presence of three highly divergent HIV-2 strains, one of which (from one of the healthy subjects) was significantly more closely related to simian immunodeficiency viruses infecting sooty mangabeys and rhesus macaques (SIVSM/SIVMAC) than to any virus of human derivation. This subject also harboured multiply defective viral genotypes that resulted from hypermutation of G to A bases. Our results indicate that HIV-2, SIVSM and SIVMAC comprise a single, highly diverse group of lentiviruses which cannot be separated into distinct phylogenetic lineages according to species of origin.

Non-specific abdominal pain: the resource implications

Non-specific abdominal pain (NSAP) is responsible for a significant proportion of emergency surgical admissions with resultant resource implications. The extent of the problem was assessed in a consecutive group of 100 patients, aged between 15 and 35 years, admitted with lower abdominal pain to one general surgical firm. No less than 67 of these patients (67%) were diagnosed as having NSAP (13.29% of all general surgical admissions), most (75%) being female and having a mean hospital stay of 4.1 days. Only 11 patients (11%) had appendicitis and the remaining 22 had miscellaneous gynaecological, urological or gastrointestinal problems. Detailed analysis of the resources used revealed that the mean cost to the NHS of each case of NSAP was 807 pounds, the bulk of which was attributable to the hospital stay. Wider assessment of the problem (by means of postal questionnaire) suggests that the cost to the NHS in Wales is in the region of 6 million pounds per year and may be over 100 million pounds per year in the UK as a whole.

Physiological comparison of international, national and regional alpine skiers

The purpose of this study was to evaluate the predictive power of physiological tests in categorizing competitive alpine skiers. Sixty-one subjects (30 female and 31 male) were classified into three levels: international, national, and regional on the basis of past competition results. Hydrostatic weighing, maximal cycling, Wingate, 60-s repeated jump, and vertical jump tests were used to assess body composition, aerobic and anaerobic power, respectively. MANOVA revealed a significant group by gender interaction (Hotellings T, p less than .001), and main effects of gender and group (p less than .001). Discriminant analyses performed separately for male and female groups determined which variables were responsible for differences and resulted in selection of the following variables for classification of the men: average work from the repeated jump, absolute power for the vertical jump, and Wingate endurance. For the women, average work from the repeated jump, absolute and relative vertical jump power, absolute maximum Wingate power, and relative repeated jump power were most important. Fat-free mass was a powerful predictor for both sexes because of its strong relationship (r greater than 0.85) with power results. Aerobic power was not useful in group classification. In conclusion, physiological tests of anaerobic power and fat-free mass were the best predictors of group membership.

Improvement in severe onchocercal skin disease after a single dose of ivermectin

PURPOSE

Skin disease is the most common clinically important manifestation of onchocerciasis. Ivermectin, a newly available drug, is well tolerated and effective in Onchocerca volvulus infection. However, little information is available regarding its effect on onchocercal skin disease. The purpose of this study was to examine, in patients with well-characterized onchodermatitis, the effect of a single dose of ivermectin.

SUBJECTS AND METHODS

Twenty-one persons with severe onchodermatitis were followed over a 6-month period. In order to evaluate the effect of ivermectin on their skin lesions, photographic transparencies were made before treatment and at 3 and 6 months after treatment. These were then evaluated in a blinded fashion.

RESULTS

Following a single dose of 150 micrograms/kg, there was a significant improvement in dermatitis in the first 3 months after treatment. All 14 persons with the worst skin disease showed improvement. The drug had no demonstrable effect on depigmented lesions over the period of observation. Treatment was well tolerated.

CONCLUSION

Single-dose ivermectin shows promise as the first acceptable treatment for severe onchocercal dermatitis.

Ocular manifestations of onchocerciasis in a rain forest area of west Africa

The epidemiology and natural history of onchocerciasis and its ocular complications in rain forest areas are poorly understood. The present study was conducted on a rubber plantation in a hyperendemic area in the rain forest of Liberia, West Africa, where 800 persons were examined. The prevalence of infection was 84% overall 29% had intraocular microfilariae, and 2.4% were blind in one or both eyes. Onchocerciasis was the cause of all binocular blindness and one-third of all visual impairment. Over half of the visual impairment caused by onchocerciasis was due to posterior segment diseases. Chorioretinal changes were present in 75% of people, and included intraretinal pigment clumping in 52% and retinal pigment epithelium atrophy in 32%. Atrophy of the retinal pigment epithelium was associated with increasing age and severity of infection. Intraretinal pigment was strongly associated with anterior uveitis. There was a strong correlation between uveitis and the inflammatory chorioretinal sequelae: retinitis, intraretinal pigment, subretinal fibrosis, and optic neuropathy. These findings indicate that considerable visual impairment associated with rain forest onchocerciasis is common and is due largely to chorioretinal disease.

A comparison of 6-, 12-, and 24-monthly dosing with ivermectin for treatment of onchocerciasis

This study was designed to examine the optimal dose and interval of administration of ivermectin, the now-accepted drug of choice for onchocerciasis. Two hundred Liberians with Onchocerca volvulus infection received 100, 150, or 200 micrograms/kg ivermectin or placebo and were followed for 36 months. The reaction after the second dose of ivermectin was significantly less than after the initial dose, although it was still significant in the 200-micrograms/kg group. The skin microfilaria counts in the group treated 6-monthly with 150 micrograms/kg was significantly less than in the group treated yearly (12 and 24 months after initial therapy). Prevalence of microfilariae in the anterior chamber and punctate corneal opacities decreased progressively in all groups over 3 years. There appears to be a slight advantage, in terms of antiparasitic effect over the first 2 years, of therapy given 6-monthly compared with yearly.

Grand rounds revisited: results of a survey of U.S. Departments of Medicine

Medical grand rounds is a time-honored weekly conference at United States teaching hospitals. We surveyed 122 departments of medicine to test the hypothesis that grand rounds may have changed with the changing training environment. Our goal was to gain a new perspective on the way physicians learn clinical medicine and maintain their fund of information. A questionnaire was designed to assess several aspects of grand rounds, including format, objectives, popularity, and changes over time. The questionnaire was directed to department heads of 122 U.S. medical schools. Seventy-five percent of respondents were department chairs; the remainder were chief residents and other faculty. Survey response rate was 96%. According to respondents, the major objective of grand rounds was to provide "updates in diagnosis and treatment." Case presentations were regularly included in about one third of departments; patients were rarely present for examination or interview. The popularity of grand rounds was thought to have decreased. These data support the impression that medical grand rounds is still considered important in most academic medical centers. Suggestions are made for increasing the clinical relevance of the conference. New techniques for presenting clinical material are reviewed, and an argument is made for returning to a basic strategy of "solving the patient's problem."

Safety of and compliance with community-based ivermectin therapy

In a study of the safety, acceptability, and efficacy of ivermectin for community-based mass treatment of onchocerciasis, the drug was issued twice, one year apart, to the population of a rubber plantation (14,000 people) in Liberia, where over 80% of the adults have Onchocerca volvulus infection. The plantation microfilarial load in a sample of adults was reduced by 86% 6 months after initial treatment and by 78% after 1 year. Compliance was 97% with each round of treatment. After the initial treatment of 7699 people, 101 (1.3%) had moderate adverse reactions. After re-treatment only 37 (0.5%) people had moderate adverse reactions. No ivermectin-related death or severe adverse reactions occurred. The data show that community-based treatment with ivermectin is well accepted and effective in reducing microfilarial loads. Ivermectin is likely to provide the first realistic means of chemotherapy-based control of onchocerciasis on a mass scale.