Rainy weather and medical school admission interviews

Mood can influence behaviour and consumer choice in diverse settings. We found that such cognitive influences extend to candidate admission interviews at a Canadian medical school. We suggest that an awareness of this fallibility might lead to more reasonable medical school admission practices.Admission offers to medical school are competitive and sometimes based on an interview. Psychology research suggests, however, that interviews are prone to subconscious biases from extraneous factors unrelated to the candidate.¹ One of the most fundamental observations is that people interviewed on rainy days tend to receive lower ratings than people interviewed on sunny days.² We studied whether this bias also extends to admission interviews at a large Canadian medical school.We analyzed the results of consecutive medical school interviews at the University of Toronto between 2004 and 2009. We included all data available with no exclusions. Almost all interviews occurred in the early spring. Scores for each interview were obtained from the admissions office as recorded from 0 to 20.³ This Likert scale was anchored with integer values where 10 denoted “unsuitable,” 12 denoted “marginal,” 14 denoted “fair,” 16 denoted “good,” 18 denoted “excellent” and 20 denoted “outstanding.”We obtained weather data from the official government archive and defined a priori the day as “rainy” if precipitation (including freezing rain, snow and hail) occurred in the morning or afternoon.⁴ Otherwise, we defined the day as “sunny.” We did not examine more complex combinations with time lags, such as when a sunny day followed multiple rainy days.A total of 2926 candidates were interviewed over the 6-year period. As expected, their demographic characteristics were unrelated to the weather (Appendix 1, available online at www.cmaj.ca/cgi/content/full/cmaj.091546/DC1). Overall, those interviewed on rainy days received about a 1% lower score than those interviewed on sunny days (average score 16.31 v. 16.49, p = 0.042). This pattern was consistent for both senior interviewers (16.39 v. 16.55, p = 0.08) and junior interviewers (16.23 v. 16.42, p = 0.041). We next used logistic regression to analyze subsequent admission decisions. The difference in scores was equivalent to about a 10% lower total mark on the Medical College Admission Test.Open in a separate windowWe suggest that cognitive patterns evident in controlled psychology laboratories can also occur in regular medical settings. The magnitude of the specific influence may be modest, but such small differences can be important in some cases because each year there are about 100 candidates who receive a score within 1% of the admission threshold.⁵ In this study, we examined only one extraneous influence on mood. Many additional factors may also affect mood (e.g., ambiance, deportment, humour and scent).² Calling attention to these issues may diminish their impact on judgment.¹     

Chronic inflammation as a determinant of future aging phenotypes

Background:

The importance of chronic inflammation as a determinant of aging phenotypes may have been underestimated in previous studies that used a single measurement of inflammatory markers. We assessed inflammatory markers twice over a 5-year exposure period to examine the association between chronic inflammation and future aging phenotypes in a large population of men and women.

Methods:

We obtained data for 3044 middle-aged adults (28.2% women) who were participating in the Whitehall II study and had no history of stroke, myocardial infarction or cancer at our study’s baseline (1997–1999). Interleukin-6 was measured at baseline and 5 years earlier. Cause-specific mortality, chronic disease and functioning were ascertained from hospital data, register linkage and clinical examinations. We used these data to create 4 aging phenotypes at the 10-year follow-up (2007–2009): successful aging (free of major chronic disease and with optimal physical, mental and cognitive functioning), incident fatal or nonfatal cardiovascular disease, death from noncardiovascular causes and normal aging (all other participants).

Results:

Of the 3044 participants, 721 (23.7%) met the criteria for successful aging at the 10-year follow-up, 321 (10.6%) had cardiovascular disease events, 147 (4.8%) died from noncardiovascular causes, and the remaining 1855 (60.9%) were included in the normal aging phenotype. After adjustment for potential confounders, having a high interleukin-6 level (> 2.0 ng/L) twice over the 5-year exposure period nearly halved the odds of successful aging at the 10-year follow-up (odds ratio [OR] 0.53, 95% confidence interval [CI] 0.38–0.74) and increased the risk of future cardiovascular events (OR 1.64, 95% CI 1.15–2.33) and noncardiovascular death (OR 2.43, 95% CI 1.58–3.80).

Interpretation:

Chronic inflammation, as ascertained by repeat measurements, was associated with a range of unhealthy aging phenotypes and a decreased likelihood of successful aging. Our results suggest that assessing long-term chronic inflammation by repeat measurement of interleukin-6 has the potential to guide clinical practice. Chronic inflammation has been implicated in the pathogenesis of age-related conditions, ¹ such as type 2 diabetes, ^{2 , 3} cardiovascular disease, ⁴ cognitive impairment ⁵ and brain atrophy. ⁶ Chronic inflammation may result from or be a cause of age-related disease processes (illustrated in Appendix 1, available at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.122072/-/DC1 ). For example, obesity increases inflammation, and chronic inflammation, in turn, contributes to the development of type 2 diabetes by inducing insulin resistance, ^{7 , 8} and to coronary artery disease by promoting atherogenesis. ⁹ Thus, raised levels of inflammation appear to be implicated in various pathological processes leading to diseases in older age. Of the various markers of systemic inflammation, interleukin-6 is particularly relevant to aging outcomes. There is increasing evidence that interleukin-6 is the pro-inflammatory cytokine that “drives” downstream inflammatory markers, such as C-reactive protein and fibrinogen. ^{10 , 11} Interleukin-6, in contrast to C-reactive protein and fibrinogen, is also likely to play a causal role in aging owing to its direct effects on the brain and skeletal muscles. ^{12 , 13} In addition, results of Mendelian randomization studies of interleukin-6 and studies of antagonists are consistent with a causal role for interleukin-6 in relation to coronary artery disease, again in contrast to C-reactive protein and fibrinogen. ¹⁴ However, current understanding of the link between chronic inflammation and aging phenotypes is hampered by the methodologic limitations of many existing studies. Most studies reported an assessment of inflammation based on a single measurement, precluding a distinction between the short-term (acute) and longer-term (chronic) impact of the inflammatory process on disease outcomes. ⁷ We conducted a study using 2 measurements of interleukin-6 obtained about 5 years apart to examine the association between chronic inflammation and aging phenotypes assessed 10 years later in a large population of men and women. Because inflammation characterizes a wide range of pathological processes, we considered several aging phenotypes, including cardiovascular disease (fatal and nonfatal), death from noncardiovascular causes and successful aging (optimal functioning across different physical, mental and cognitive domains).     

Destroyed documents: uncovering the science that Imperial Tobacco Canada sought to conceal

Background

In 1992, British American Tobacco had its Canadian affiliate, Imperial Tobacco Canada, destroy internal research documents that could expose the company to liability or embarrassment. Sixty of these destroyed documents were subsequently uncovered in British American Tobacco’s files.

Methods

Legal counsel for Imperial Tobacco Canada provided a list of 60 destroyed documents to British American Tobacco. Information in this list was used to search for copies of the documents in British American Tobacco files released through court disclosure. We reviewed and summarized this information.

Results

Imperial Tobacco destroyed documents that included evidence from scientific reviews prepared by British American Tobacco’s researchers, as well as 47 original research studies, 35 of which examined the biological activity and carcinogenicity of tobacco smoke. The documents also describe British American Tobacco research on cigarette modifications and toxic emissions, including the ways in which consumers adapted their smoking behaviour in response to these modifications. The documents also depict a comprehensive research program on the pharmacology of nicotine and the central role of nicotine in smoking behaviour. British American Tobacco scientists noted that “… the present scale of the tobacco industry is largely dependent on the intensity and nature of the pharmacological action of nicotine,” and that “... should nicotine become less attractive to smokers, the future of the tobacco industry would become less secure.”

Interpretation

The scientific evidence contained in the documents destroyed by Imperial Tobacco demonstrates that British American Tobacco had collected evidence that cigarette smoke was carcinogenic and addictive. The evidence that Imperial Tobacco sought to destroy had important implications for government regulation of tobacco.On May 8, 1998, the US State of Minnesota reached a historic settlement with the tobacco industry.¹ As part of the settlement, the 7 tobacco manufacturers named in the trial were ordered to pay more than $200 billion dollars and to make public over 40 million pages of internal tobacco industry documents. These documents have provided a wealth of information about the conduct of the tobacco industry, the health effects of smoking and the role of cigarette design in promoting addiction.²A number of the most sensitive documents were concealed or destroyed before the trial as the threat of litigation grew.^3,4 Based on advice from their lawyers, companies such as British American Tobacco instituted a policy of document destruction.⁵ A.G. Thomas, the head of Group Security at British American Tobacco, explained the criteria for selecting reports for destruction: “In determining whether a redundant document contains sensitive information, holders should apply the rule of thumb of whether the contents would harm or embarrass the Company or an individual if they were to be made public.”⁶British American Tobacco’s destruction policy was most rigorously pursued by its subsidiaries in the United States, Canada and Australia, likely because of the imminent threat of litigation in these countries. The policy was developed following the 1989 decision by a Canadian judge to give Canadian government representatives access to scientific research conducted by Imperial Tobacco Canada and its principal shareholder, British American Tobacco.⁷ This ruling prompted British American Tobacco to undertake steps to prevent scientists in its affiliate companies from retaining industry studies and to require the destruction of sensitive documents.^8,9 Canadian scientists were the most resistant to this policy,¹⁰ but they too agreed to destroy their copies of British American Tobacco’s scientific research.¹¹In a letter dated June 5, 1992, a lawyer working on behalf of Imperial Tobacco Canada informed British American Tobacco that Imperial would destroy copies of 60 documents in compliance with the document destruction policy, and he provided reference numbers for each of these documents.¹² This memo was one of the earlier industry documents to be made public, and it became a key document in legal arguments about the destruction of evidence.¹³ The contents of the destroyed documents to which it referred, however, had never been analyzed. All that was known was that they contained what British American Tobacco considered “sensitive” research results.¹⁴ A list of the 60 documents is available in Appendix 1 (www.cmaj.ca/cgi/content/full/cmaj.080566/DC1). Appendix 2 (www.cmaj.ca/cgi/content/full/cmaj.080566/DC1) includes summaries of 3 documents not otherwise discussed that explore the transfer of the flavouring additive coumarin to tobacco smoke.^15–17What was the nature of the 60 reports that Imperial and British American Tobacco wanted destroyed? Although Imperial dutifully destroyed its copies of these sensitive documents, other copies of the same documents were stored at British American Tobacco headquarters in the United Kingdom and were released in 1998 through court disclosure in the Minnesota Trial and subsequent legal proceedings.¹ We searched British American Tobacco’s archives for each of the 60 reports using the research numbers included in the original letter.¹² In this article, we present the contents of these research reports.     

Effectiveness of a quality-improvement program in improving management of primary care practices

Background:

The European Practice Assessment program provides feedback and outreach visits to primary care practices to facilitate quality improvement in five domains (infrastructure, people, information, finance, and quality and safety). We examined the effectiveness of this program in improving management in primary care practices in Germany, with a focus on the domain of quality and safety.

Methods:

In a before–after study, 102 primary care practices completed a practice assessment using the European Practice Assessment instrument at baseline and three years later (intervention group). A comparative group of 102 practices was included that completed their first assessment using this instrument at the time of the intervention group’s second assessment. Mean scores were based on the proportion of indicators for which a positive response was achieved by all of the practices, on a scale of 0 to 100.

Results:

We found significant improvements in all domains between the first and second assessments in the intervention group. In the domain of quality and safety, improvements in scores (mean scores were based on the proportion of indicators for which a positive response was achieved by all of the practices, on a scale of 0 to 100) were observed in the following dimensions: complaint management (from a mean score of 51.2 at first assessment to 80.7 at second assessment); analysis of critical incidents (from 79.1 to 89.6); and quality development, quality policy (from 40.7 to 55.6). Overall scores at the time of the second assessment were significantly higher in the intervention group than in the comparative group.

Interpretation:

Primary care practices that completed the European Practice Assessment instrument twice over a three-year period showed improvements in practice management. Our findings show the value of the quality-improvement cycle in the context of practice assessment and the use of established organizational standards for practice management with the Europeaen Practice Assessment.A variety of quality-improvement initiatives in health care management have been implemented in most health care systems.^1,2 Countries such as Australia, New Zealand, the United Kingdom and the United States have a long tradition in, and established standards for, quality management in primary care. In Canada, such initiatives in primary care are in their infancy, despite support by the federal Primary Health Care Transition Fund since 2000.³ In Ontario, a comprehensive book was recently issued that provides recommendations on practice management and clinical indicators for improving quality in primary care settings in the province.⁴ The indicators were adopted and refined from the Royal New Zealand College of General Practitioners, the Royal Australian College of General Practitioners’ National Expert Committee on Standards for General Practices, the TOPAS–Europe Association European Practice Assessment, the United Kingdom’s Quality and Outcomes Framework and the Canadian Institute for Health Information.In Germany, similar developments took place. In 2005, the German government stipulated that health care providers implement a system of annual assessment of quality management.⁵ One of the systems available to practices is the European Practice Assessment (www.epa-qm.de), a validated instrument based on quality indicators for assessing practice management.⁶ The five key domains of the European Practice Assessment instrument and their respective dimensions are described in Figure 1.Open in a separate windowFigure 1:The domains and dimensions (and number of indicators) of the European Practice Assessment instrument used to measure the quality of practice management in primary care practices. For an example of how the pentagon shape is used to provide feedback to individual practices, see Appendix 1 (available at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.110412/-/DC1). GP = general practitioner.The European Practice Assessment is used to help general practices both assess and improve their quality of practice management set against predefined criteria with embedded quality indicators. The improvement process is ongoing (e.g., through plan–do–study–act cycles⁷): each step is reviewed and redesigned with a view to improving the quality of the end product, thereby fostering continuous improvement.⁸ The multifaceted strategy has three essential components: assessment and feedback using validated instruments based on quality indicators; external support through an outreach educational visit by a trained visitor (physician or nurse) to support the practice in improving areas of management identified by the practice;⁹ and formal accreditation by an external organization.Three requirements have to be fulfilled by practices to receive accreditation: achieve a positive response for more than 50% of the indicators; meet predefined safety indicators (e.g., the vaccination status of staff regarding hepatitis B vaccination is recorded and medical equipment is checked regularly according to national regulations); and highlight areas for continuous quality improvement.Accreditation is one method for assessing and benchmarking the performance of general practice care across a broad range of clinical and organizational domains. It describes a formal process of self-assessment and external and independent peer review to encourage best management practice and can result in recommendations for continuous improvement of safety and quality in the practice.⁸ Practice accreditation can be used for different purposes: quality control, regulation, quality improvement, providing data on performance, and marketing.⁸ In Germany, it is used for quality improvement, leading to a certificate.We conducted a study to determine whether improvements in practice management occurred in general practices that completed the European Practice Assessment twice over three years, compared with general practices that completed the European Practice Assessment once. We focused our analysis on the domain of quality and safety, expecting an association between practice organization and quality improvement.^10,11 We hypothesized that the initial use of the European Practice Assessment and reassessment with it three years later would result in improved scores in the dimensions and indicators within the domain of quality and safety.     

Obstructive sleep apnea and the prevalence and incidence of cancer

Background:

A link between obstructive sleep apnea and cancer development or progression has been suggested, possibly through chronic hypoxemia, but supporting evidence is limited. We examined the association between the severity of obstructive sleep apnea and prevalent and incident cancer, controlling for known risk factors for cancer development.

Methods:

We included all adults referred with possible obstructive sleep apnea who underwent a first diagnostic sleep study at a single large academic hospital between 1994 and 2010. We linked patient data with data from Ontario health administrative databases from 1991 to 2013. Cancer diagnosis was derived from the Ontario Cancer Registry. We assessed the cross-sectional association between obstructive sleep apnea and prevalent cancer at the time of the sleep study (baseline) using logistic regression analysis. Cox regression models were used to investigate the association between obstructive sleep apnea and incident cancer among patients free of cancer at baseline.

Results:

Of 10 149 patients who underwent a sleep study, 520 (5.1%) had a cancer diagnosis at baseline. Over a median follow-up of 7.8 years, 627 (6.5%) of the 9629 patients who were free of cancer at baseline had incident cancer. In multivariable regression models, the severity of sleep apnea was not significantly associated with either prevalent or incident cancer after adjustment for age, sex, body mass index and smoking status at baseline (apnea–hypopnea index > 30 v. < 5: adjusted odds ratio [OR] 0.96, 95% confidence interval [CI] 0.71–1.30, for prevalent cancer, and adjusted hazard ratio [HR] 1.02, 95% CI 0.80–1.31, for incident cancer; sleep time spent with oxygen saturation < 90%, per 10-minute increase: adjusted OR 1.01, 95% CI 1.00–1.03, for prevalent cancer, and adjusted HR 1.00, 95% CI 0.99–1.02, for incident cancer).

Interpretation:

In a large cohort, the severity of obstructive sleep apnea was not independently associated with either prevalent or incident cancer. Additional studies are needed to elucidate whether there is an independent association with specific types of cancer.Obstructive sleep apnea is a sleep-related breathing disorder characterized by repetitive episodes of upper-airway obstruction during sleep. Through sleep fragmentation, hypoxemia, hypercapnia, swings in intrathoracic pressure and increased sympathetic activity, these episodes lead to symptoms and health consequences.¹ In 2009, 23% of Canadian adults reported risk factors for obstructive sleep apnea, and 5% of the population 45 years and older reported being told by a health professional that they had the condition.²Obstructive sleep apnea has been postulated to cause cancer^3,4 or cancer progression,⁵ possibly through chronic intermittent hypoxemia,⁶ thus making it a potential modifiable risk factor for cancer development.⁷ However, the longitudinal evidence on this association is limited. Four cohort studies evaluated the longitudinal association between obstructive sleep apnea (expressed by the apnea–hypopnea index, oxygen desaturation or symptoms) and cancer development or cancer-related mortality (Appendix 1, available at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.140238/-/DC1).^3–5,8 All had limitations. Of the 3 that reported a positive association,^3,5,8 2 studies included a small number of participants with severe obstructive sleep apnea, had a relatively small number of events and did not consider competing risk of death from other causes;^5,8 and 2 used less reliable sleep-testing devices to define obstructive sleep apnea,^3,8 which may have introduced measurement bias. In the only study that did not show an association between obstructive sleep apnea and cancer,⁴ the former was diagnosed on the basis of self-reported symptoms, which could have resulted in misclassification of exposure.There is a need for a sufficiently large cohort study with a long enough follow-up to allow for the potential development of cancer that adjusts for important potential confounders, examines common cancer subtypes and has a rigorous assessment of both obstructive sleep apnea and cancer.^7,9,10 Our study was designed to improve upon the methods of published studies. We examined the association between the severity of obstructive sleep apnea (expressed by the apnea–hypopnea index or oxygen desaturation) and prevalent or incident cancer after controlling for known cancer risk factors.     

Do clinicians understand the size of treatment effects? A randomized survey across 8 countries

Background:

Meta-analyses of continuous outcomes typically provide enough information for decision-makers to evaluate the extent to which chance can explain apparent differences between interventions. The interpretation of the magnitude of these differences — from trivial to large — can, however, be challenging. We investigated clinicians’ understanding and perceptions of usefulness of 6 statistical formats for presenting continuous outcomes from meta-analyses (standardized mean difference, minimal important difference units, mean difference in natural units, ratio of means, relative risk and risk difference).

Methods:

We invited 610 staff and trainees in internal medicine and family medicine programs in 8 countries to participate. Paper-based, self-administered questionnaires presented summary estimates of hypothetical interventions versus placebo for chronic pain. The estimates showed either a small or a large effect for each of the 6 statistical formats for presenting continuous outcomes. Questions addressed participants’ understanding of the magnitude of treatment effects and their perception of the usefulness of the presentation format. We randomly assigned participants 1 of 4 versions of the questionnaire, each with a different effect size (large or small) and presentation order for the 6 formats (1 to 6, or 6 to 1).

Results:

Overall, 531 (87.0%) of the clinicians responded. Respondents best understood risk difference, followed by relative risk and ratio of means. Similarly, they perceived the dichotomous presentation of continuous outcomes (relative risk and risk difference) to be most useful. Presenting results as a standardized mean difference, the longest standing and most widely used approach, was poorly understood and perceived as least useful.

Interpretation:

None of the presentation formats were well understood or perceived as extremely useful. Clinicians best understood the dichotomous presentations of continuous outcomes and perceived them to be the most useful. Further initiatives to help clinicians better grasp the magnitude of the treatment effect are needed.Health professionals increasingly rely on summary estimates from systematic reviews and meta-analyses to guide their clinical decisions and to provide information for shared decision-making. Meta-analyses of clinical trials typically provide the information necessary for decision-makers to evaluate the extent to which chance can explain apparent intervention effects (i.e., statistical significance). However, interpreting the magnitude of the treatment effect — from trivial to large — particularly for continuous outcome measures, can be challenging.Such challenges include decision-makers’ unfamiliarity with the instruments used to measure the outcome. For instance, without further information, clinicians may have difficulty grasping the importance of a 5-point difference on the Short-Form Health Survey-36 (SF-36) or a 1-point difference on a visual analogue scale for pain.¹ Second, trials often use different instruments to measure the same construct. For instance, investigators may measure physical function among patients with arthritis using 1 of 5 instruments (the Western Ontario and McMaster Universities Arthritis Index using either a visual analogue or Likert scale; the Arthritis Impact Measurement Scale; the SF-36 Physical Function; or the Lequesne index).^2,3Authors have several options for pooling results of continuous outcomes. When all trials have used the same instrument to measure outcomes such as physical function or pain, the most straightforward method is to present the mean difference in natural units between the intervention and control groups. When trialists have used different instruments to measure the same construct, authors of systematic reviews typically report differences between intervention and control groups in standard deviation units, an approach known as the standardized mean difference (SMD). This approach involves dividing the mean difference in each trial by the pooled standard deviation for that trial’s outcome.⁴For meta-analyses of outcomes measured using different instruments, presenting results as an SMD is the longest standing and most widely used approach and is recommended in the Cochrane handbook for systematic reviews of interventions.⁴ Limitations of this approach include, however, statistical bias toward decreased treatment effects,^5,6 the possibility that decision-makers will find the measure difficult to interpret^7,8 and the possibility that the same treatment effect will appear different depending on whether the study population had similar results in the measure of interest (i.e., if homogeneous, a small standard deviation) or varied greatly in the measure of interest (i.e., if heterogeneous, a large standard deviation).^9,10Several research groups have proposed alternative statistical formats for presenting continuous outcomes from meta-analyses that they postulate clinicians will more easily interpret.^{6–8,11–16} The Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group recently provided an overview of methods for presenting pooled continuous data.^9,10 These alternatives (Appendix 1, available at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.150430/-/DC1), although intuitively compelling, have seen limited use.We conducted a survey to determine clinicians’ understanding of the magnitude of treatment effect for 6 approaches to the presentation of continuous outcomes from meta-analyses, as well as their perceptions of the usefulness of each approach for clinical decision-making. We also evaluated whether their understanding and perceptions of usefulness were influenced by country, medical specialty, clinical experience or training in health research methodology.     

Cardiac resynchronization therapy: a meta-analysis of randomized controlled trials

Background

Studies of cardiac resynchronization therapy in addition to an implantable cardioverter defibrillator in patients with mild to moderate congestive heart failure had not been shown to reduce mortality until the recent RAFT trial (Resynchronization/Defibrillation for Ambulatory Heart Failure Trial). We performed a meta-analysis including the RAFT trial to determine the effect of cardiac resynchronization therapy with or without an implantable defibrillator on mortality.

Methods

We searched electronic databases and other sources for reports of randomized trials using a parallel or crossover design. We included studies involving patients with heart failure receiving optimal medical therapy that compared cardiac resynchronization therapy with optimal medical therapy alone, or cardiac resynchronization therapy plus an implantable defibrillator with a standard implantable defibrillator. The primary outcome was mortality. The optimum information size was considered to assess the minimum amount of information required in the literature to reach reliable conclusions about cardiac resynchronization therapy.

Results

Of 3071 reports identified, 12 studies (n = 7538) were included in our meta-analysis. Compared with optimal medical therapy alone, cardiac resynchronization therapy plus optimal medical therapy significantly reduced mortality (relative risk [RR] 0.73, 95% confidence interval [CI] 0.62–0.85). Compared with an implantable defibrillator alone, cardiac resynchronization therapy plus an implantable defibrillator significantly reduced mortality (RR 0.83, 95% CI 0.72–0.96). This last finding remained significant among patients with New York Heart Association (NYHA) class I or II disease (RR 0.80, 95% CI 0.67–0.96) but not among those with class III or IV disease (RR 0.84, 95% CI 0.69–1.07). Analysis of the optimum information size showed that the sequential monitoring boundary was crossed, which suggests no need for further clinical trials.

Interpretation

The cumulative evidence is now conclusive that the addition of cardiac resynchronization to optimal medical therapy or defibrillator therapy significantly reduces mortality among patients with heart failure.Congestive heart failure is currently reaching epidemic proportions in Canada, with 500 000 Canadians affected and 50 000 new patients identified each year.¹ It accounts for more than 100 000 hospital admissions per year and has a one-year mortality ranging from 15% to 50%, depending on the severity of heart failure.² By 2050, the number of patients with heart failure is projected to increase threefold.²Advances in medical therapies have resulted in substantial reductions in mortality associated with congestive heart failure.^3–7 The use of devices has recently become an important adjuvant therapy.⁸ Cardiac resynchronization therapy involves pacing from both the right and left ventricles simultaneously to improve myocardial efficiency (see radiographs in Appendix 1, at www.cmaj.ca/cgi/content/full/cmaj.101685/DC1). Cardiac resynchronization therapy has been shown to reduce morbidity and, when compared with medical therapy alone, to reduce mortality.^9–13 Until recently, it was not shown to reduce mortality among patients who also received an implantable cardioverter defibrillator. Among patients receiving optimal medical therapy, the Resynchronization/Defibrillation for Ambulatory Heart Failure Trial (RAFT) showed the superiority of cardiac resynchronization therapy in addition to an implantable defibrillator over a standard implantable defibrillator in reducing mortality and the combined outcome of death from any cause or hospital admission related to heart failure.¹⁴We performed a meta-analysis to further assess the effect on mortality of cardiac resynchronization therapy with and without an implantable defibrillator among patients with mildly symptomatic and advanced heart failure.     

A prospective cluster-randomized trial to implement the Canadian CT Head Rule in emergency departments

Background

The Canadian CT Head Rule was developed to allow physicians to be more selective when ordering computed tomography (CT) imaging for patients with minor head injury. We sought to evaluate the effectiveness of implementing this validated decision rule at multiple emergency departments.

Methods

We conducted a matched-pair cluster-randomized trial that compared the outcomes of 4531 patients with minor head injury during two 12-month periods (before and after) at hospital emergency departments in Canada, six of which were randomly allocated as intervention sites and six as control sites. At the intervention sites, active strategies, including education, changes to policy and real-time reminders on radiologic requisitions were used to implement the Canadian CT Head Rule. The main outcome measure was referral for CT scan of the head.

Results

Baseline characteristics of patients were similar when comparing control to intervention sites. At the intervention sites, the proportion of patients referred for CT imaging increased from the “before” period (62.8%) to the “after” period (76.2%) (difference +13.3%, 95% CI 9.7%–17.0%). At the control sites, the proportion of CT imaging usage also increased, from 67.5% to 74.1% (difference +6.7%, 95% CI 2.6%–10.8%). The change in mean imaging rates from the “before” period to the “after” period for intervention versus control hospitals was not significant (p = 0.16). There were no missed brain injuries or adverse outcomes.

Interpretation

Our knowledge–translation-based trial of the Canadian CT Head Rule did not reduce rates of CT imaging in Canadian emergency departments. Future studies should identify strategies to deal with barriers to implementation of this decision rule and explore more effective approaches to knowledge translation. (ClinicalTrials.gov trial register no. NCT00993252)More than six million instances of head and neck trauma are seen annually in emergency departments in Canada and the United States.¹ Most are classified as minimal or minor head injury, but in a very small proportion, deterioration occurs and neurosurgical intervention is needed for intracranial hematoma.^2,3 In recent years, North American use of computed tomography (CT) for many conditions in the emergency department, including minor head injury, has increased five-fold.^1,4 Our own Canadian data showed marked variation in the use of CT for similar patients.⁵ Over 90% of CT scans are negative for clinically important brain injury.^6–8 Owing to its high volume of usage, such imaging adds to health care costs. There have also been increasing concerns about radiation-related risk from unnecessary CT scans.^9,10 Additionally, unnecessary use of CT scanning compounds the Canadian problems of overcrowding of emergency departments and inadequate access to advanced imaging for nonemergency outpatients.Clinical decision rules are derived from original research and may be defined as tools for clinical decision-making that incorporate three or more variables from a patient’s history, physical examination or simple tests.^11–13 The Canadian CT Head Rule comprises five high-risk and two medium-risk criteria and was derived by prospectively evaluating 3121 adults with minor head injury (Figure 1) (Appendix 1, available at www.cmaj.ca/cgi/content/full/cmaj.091974/DC1).⁶ The resultant decision rule was then prospectively validated in a group of 2707 patients and showed high sensitivity (100%; 95% confidence interval [CI ] 91–100) and reliability.¹⁴ The results of its validation suggested that, in patients presenting to emergency departments with minor head trauma, a rate of usage of CT imaging as low as 62.4% was possible and safe.Open in a separate windowFigure 1The Canadian CT Head Rule, as used in the study. Note: CSF = cerebrospinal fluid, CT = computed tomography, GCS = Glasgow Coma Scale.Unfortunately, most decision rules are never used after derivation because they are not adequately tested in validation or implementation studies.^15–19 We recently successfully implemented a similar rule, the Canadian C-Spine Rule, at multiple Canadian sites.²⁰ Hence, the goal of the current study was to evaluate the effectiveness and safety of an active strategy to implement the Canadian CT Head Rule at multiple emergency departments. We wanted to test both the impact of the rule on rates of CT imaging and the effectiveness of an inexpensive and easily adopted implementation strategy. In addition, we wanted to further evaluate the accuracy of the rule.     

The cost-effectiveness of screening for colorectal cancer

Background

Published decision analyses show that screening for colorectal cancer is cost-effective. However, because of the number of tests available, the optimal screening strategy in Canada is unknown. We estimated the incremental cost-effectiveness of 10 strategies for colorectal cancer screening, as well as no screening, incorporating quality of life, noncompliance and data on the costs and benefits of chemotherapy.

Methods

We used a probabilistic Markov model to estimate the costs and quality-adjusted life expectancy of 50-year-old average-risk Canadians without screening and with screening by each test. We populated the model with data from the published literature. We calculated costs from the perspective of a third-party payer, with inflation to 2007 Canadian dollars.

Results

Of the 10 strategies considered, we focused on three tests currently being used for population screening in some Canadian provinces: low-sensitivity guaiac fecal occult blood test, performed annually; fecal immunochemical test, performed annually; and colonoscopy, performed every 10 years. These strategies reduced the incidence of colorectal cancer by 44%, 65% and 81%, and mortality by 55%, 74% and 83%, respectively, compared with no screening. These strategies generated incremental cost-effectiveness ratios of $9159, $611 and $6133 per quality-adjusted life year, respectively. The findings were robust to probabilistic sensitivity analysis. Colonoscopy every 10 years yielded the greatest net health benefit.

Interpretation

Screening for colorectal cancer is cost-effective over conventional levels of willingness to pay. Annual high-sensitivity fecal occult blood testing, such as a fecal immunochemical test, or colonoscopy every 10 years offer the best value for the money in Canada.Colorectal cancer is the fourth most common cancer diagnosed in North America and the second leading cause of cancer death.^1,2 An effective population-based screening program is likely to decrease mortality associated with colorectal cancer^3–6 through earlier detection and to decrease incidence by allowing removal of precursor colorectal adenomas.^7,8 Professional societies and government-sponsored committees have released guidelines for screening of average-risk individuals for colorectal cancer by means of several testing options.^9–12 These tests vary in sensitivity, specificity, risk, costs and availability. With no published studies designed to directly compare screening strategies, decision analysis is a useful technique for examining the relative cost-effectiveness of these strategies.^13–21 Previous studies have shown that screening for colorectal cancer is cost-effective at conventional levels of willingness to pay, but no single strategy has emerged as clinically superior or economically dominant.²² The interpretations of economic evaluations in this area have been limited because investigators have not simultaneously accounted for the positive effects of screening on quality of life, the effect of noncompliance with screening schedules, and the greater efficacy and cost of more modern chemotherapy regimens for colorectal cancer. Furthermore, no study has included all of the strategies recommended in the 2008 guidelines of the US Multi-Society Task Force on Colorectal Cancer.¹⁰Our objective was to estimate the incremental cost-effectiveness of 10 strategies for colorectal cancer screening, as well as the absence of a screening program. The current study is more complete than earlier studies because we included information on quality of life, noncompliance with screening and the efficacy observed in recent randomized trials of colorectal cancer treatments. The complete model is available in Appendix 1 (available at www.cmaj.ca/cgi/content/full/cmaj.090845/DC1). This article focuses on the comparison of no screening and three screening strategies:¹ low-sensitivity guaiac fecal occult blood test,² performed annually; fecal immunochemical test,³ performed annually; and colonoscopy, performed every 10 years. These three tests are currently being used or considered for population-based screening of average-risk individuals in some Canadian provinces.     

Vitamin B12 (cobalamin) deficiency in elderly patients

VITAMIN B₁₂ OR COBALAMIN DEFICIENCY occurs frequently (> 20%) among elderly people, but it is often unrecognized because the clinical manifestations are subtle; they are also potentially serious, particularly from a neuropsychiatric and hematological perspective. Causes of the deficiency include, most frequently, food-cobalamin malabsorption syndrome (> 60% of all cases), pernicious anemia (15%–20% of all cases), insufficent dietary intake and malabsorption. Food-cobalamin malabsorption, which has only recently been identified as a significant cause of cobalamin deficiency among elderly people, is characterized by the inability to release cobalamin from food or a deficiency of intestinal cobalamin transport proteins or both. We review the epidemiology and causes of cobalamin deficiency in elderly people, with an emphasis on food-cobalamin malabsorption syndrome. We also review diagnostic and management strategies for cobalamin deficiency. Vitamin B₁₂ or cobalamin deficiency occurs frequently among elderly patients,¹ but it is often unrecognized or not investigated because the clinical manifestations are subtle. However, the potential seriousness of the complications (particularly neuropsychiatric and hematological)^1,2,3,4 requires investigation of all patients who present with vitamin or nutritional deficiency. We summarize the current state of knowledge on cobalamin deficiency, with a particular focus on deficiency in elderly people.In gathering information for this article, we systematically searched PubMed for articles published from 1990 to July 2003 (the search strategy is outlined in online Appendix 1 [www.cmaj.ca/cgi/content/full/171/3/251/DC1]). We have also included unpublished data from our working group, the Groupe d''étude des carences en vitamine B12 des Hôpitaux Universitaires de Strasbourg.     

The Enhancing Secondary Prevention in Coronary Artery Disease trial

Background

Proven efficacious therapies are sometimes underused in patients with chronic cardiac conditions, resulting in suboptimal outcomes. We evaluated whether evidence summaries, which were either unsigned or signed by local opinion leaders, improved the quality of secondary prevention care delivered by primary care physicians of patients with coronary artery disease.

Methods

We performed a randomized trial, clustered at the level of the primary care physician, with 3 study arms: control, unsigned statements or opinion leader statements. The statements were faxed to primary care physicians of adults with coronary artery disease at the time of elective cardiac catheterization. The primary outcome was improvement in statin management (initiation or dose increase) 6 months after catheterization.

Results

We enrolled 480 adults from 252 practices. Although statin use was high at baseline (n = 316 [66%]), most patients were taking a low dose (mean 32% of the guideline-recommended dose), and their low-density lipoprotein (LDL) cholesterol levels were elevated (mean 3.09 mmol/L). Six months after catheterization, statin management had improved in 79 of 157 patients (50%) in the control arm, 85 of 158 (54%) patients in the unsigned statement group (adjusted odds ratio [OR] 1.18, 95% CI 0.71–1.94, p = 0.52) and 99 of 165 (60%) patients in the opinion leader statement group (adjusted OR 1.51, 95% CI 0.94–2.42, p = 0.09). The mean fasting LDL cholesterol levels after 6 months were similar in all 3 study arms: 2.35 (standard deviation [SD] 0.86) mmol/L in the control arm compared with 2.24 (SD 0.73) among those in the opinion leader group (p = 0.48) and 2.19 (SD 0.68) in the unsigned statement group (p = 0.32).

Interpretation

Faxed evidence reminders for primary care physicians, even when endorsed by local opinion leaders, were insufficient to optimize the quality of care for adults with coronary artery disease. ClinicalTrials.gov trial register no. {"type":"clinical-trial","attrs":{"text":"NCT00175240","term_id":"NCT00175240"}}NCT00175240.Despite the abundant evidence base for the secondary prevention of coronary artery disease,¹ many of these therapies are underused in clinical practice.^1–4 These gaps between evidence and clinical reality are linked to poor outcomes for patients.⁵ Improved uptake of secondary-prevention therapies would reduce cardiac morbidity and mortality.⁶ However, most quality-improvement initiatives in coronary artery disease have focused on patients in hospital. Few studies have evaluated means of translating evidence into clinical practice for outpatients cared for by primary care physicians.⁷Previously,⁸ we developed and tested the Local Opinion Leader Statement (Appendix 1, available at www.cmaj.ca/cgi/content/full/cmaj.090917/DC1), a quality-improvement tool consisting of a 1-page summary of evidence with explicit treatment advice about secondary prevention of coronary artery disease. This summary was endorsed by local opinion leaders and was faxed to the primary care physicians of patients with coronary artery disease. Although this fax did not lead to a significant improvement in statin prescribing, our pilot trial was small (117 patients) and enrolled patients with chronic coronary artery disease at the time they presented to their community pharmacy for medication refills. We hypothesized that this was not a “teachable moment” and that if the intervention was given at a time when the diagnosis was made, it would be more influential on the primary care physician.Thus, we designed this trial to test the impact of the opinion leader statement if it was sent to the primary physician at the time when patients were diagnosed with coronary artery disease. In addition, because local opinion leaders are not always self-evident and conducting surveys to identify them for each condition and in each locale would be time-consuming and expensive, we also evaluated the impact of an unsigned statement.     

Birth outcomes in the Inuit-inhabited areas of Canada

Background

Information on health disparities between Aboriginal and non-Aboriginal populations is essential for developing public health programs aimed at reducing such disparities. The lack of data on disparities in birth outcomes between Inuit and non-Inuit populations in Canada prompted us to compare birth outcomes in Inuit-inhabited areas with those in the rest of the country and in other rural and northern areas of Canada.

Methods

We conducted a cohort study of all births in Canada during 1990–2000 using linked vital data. We identified 13 642 births to residents of Inuit-inhabited areas and 4 054 489 births to residents of all other areas. The primary outcome measures were preterm birth, stillbirth and infant death.

Results

Compared with the rest of Canada, Inuit-inhabited areas had substantially higher rates of preterm birth (risk ratio [RR] 1.45, 95% confidence interval [CI] 1.38–1.52), stillbirth (RR 1.68, 95% CI 1.38–2.04) and infant death (RR 3.61, 95% CI 3.17–4.12). The risk ratios and absolute differences in risk for these outcomes changed little over time. Excess mortality was observed for all major causes of infant death, including congenital anomalies (RR 1.64), immaturity-related conditions (RR 2.96), asphyxia (RR 2.43), sudden infant death syndrome (RR 7.15), infection (RR 8.32) and external causes (RR 7.30). Maternal characteristics accounted for only a small part of the risk disparities. Substantial risk ratios for preterm birth, stillbirth and infant death remained when the comparisons were restricted to other rural or northern areas of Canada.

Interpretation

The Inuit-inhabited areas had much higher rates of preterm birth, stillbirth and infant death compared with the rest of Canada and with other rural and northern areas. There is an urgent need for more effective interventions to improve maternal and infant health in Inuit-inhabited areas.Birth outcomes are worse in Aboriginal than in non-Aboriginal populations in many developed countries, including the United States, Australia and Canada.^1–18 Inuit are the smallest Aboriginal group in Canada, with a population of about 45 000.¹⁹ Some regional and community studies have shown that Inuit experience the highest rates of infant mortality in Canada.^16–18 However, data are lacking at the national level on birth outcomes among Inuit owing to the absence of Aboriginal identifiers on birth registration forms in most provinces.In Canada, over 80% of all Inuit reside in one of four vast, sparsely populated regions: the Inuvialuit region of the Northwest Territories, Nunavut, Nunavik (northern Quebec) and Nunatsiavut (northern coast of Labrador) (Figure 1). Taken together, 80% of the population in those four regions is Inuit,²⁰ and 90% of the births are to Inuit women according to 2006 census data. This creates an opportunity to examine birth outcomes according to maternal place of residence in any of the four Inuit-inhabited areas of Canada. We conducted this study to describe birth outcomes in those areas compared with outcomes in the rest of country and in other rural and northern areas of Canada.Open in a separate windowFigure 1Inuit-inhabited communities in the Inuvialuit (dots), Nunavut (triangles), Nunavik (squares) and Nunatsiavut (stars) regions of Canada. Source: Statistics Canada population data. Base map © 2002 Government of Canada with permission from Natural Resources Canada.     

Finding smORFs: getting closer

Millions of small open reading frames exist in eukaryotes. We do not know how many, or which are translated, but bioinformatics is getting us closer to the answer.See related Research article: http://www.genomebiology.com/2015/16/1/179DNA sequences encoding small open reading frames (smORFs) of fewer than 100 amino acids (aa) exist in each eukaryotic genome in numbers several orders of magnitude higher than the corresponding annotated protein-coding genes (Fig. 1). Due to difficulties with bioinformatic detection and experimental analysis, along with their sheer numbers, smORFs have been ignored for a long time by mainstream genomics. Thanks to recent advances in bioinformatic and experimental techniques, however, smORFs are receiving increasing attention. Extensive use of RNA-Seq has shown that thousands of smORFs are transcribed, in many cases, in putative noncoding RNAs, and high-throughput experimental techniques have detected translation of a few hundred of these. However, the possibility remains that many more smORFs are functional, but yet uncharacterized. Bioinformatic methods followed by targeted experimental verification are needed to improve the identification of putative functional smORFs. A new paper in Genome Biology [1] provides a significant step towards such a solution.Open in a separate windowFig. 1The number of small open reading frames (smORFs) in eukaryotic genomes (shown in log scale) greatly exceeds that of annotated protein-coding genes, and reaches 265,000 in yeast [4], 556,000 in the fruit fly Drosophila [2], and 40,700,000 in mouse [3]. Note that the current number of corroborated functional smORFs is but a small fraction of these (see text and [1] for details). The number of annotated protein-coding genes was obtained from the Saccharomyces Genome Database (yeast; http://www.yeastgenome.org/), FlyBase (fruit fly; http://flybase.org/), and Ensembl (mouse; http://www.ensembl.org/index.html) (accessed 12 August 2015)     

Splenogonadal Fusion: An Unusual Case of an Acute Scrotum

We highlight a case on a normal left testicle with a fibrovascular cord with three nodules consistent with splenic tissue. The torsed splenule demonstrated hemorrhage with neutrophilic infiltrate and thrombus consistent with chronic infarction and torsion. Splenogonadal fusion (SGF) is a rather rare entity, with approximately 184 cases reported in the literature. The most comprehensive review was that of 123 cases completed by Carragher in 1990. Since then, an additional 61 cases have been reported in the scientific literature. We have studied these 61 cases in detail and have included a summary of that information here.Key words: Splenogonadal fusion, Acute scrotumA 10-year-old boy presented with worsening left-sided scrotal pain of 12 hours’ duration. The patient reported similar previous episodes occurring intermittently over the past several months. His past medical history was significant for left hip dysplasia, requiring multiple hip surgeries. On examination, he was found to have an edematous left hemiscrotum with a left testicle that was rigid, tender, and noted to be in a transverse lie. The ultrasound revealed possible polyorchism, with two testicles on the left and one on the right (Figure 1), and left epididymitis. One of the left testicles demonstrated a loss of blood flow consistent with testicular torsion (Figure 2).Open in a separate windowFigure 1Ultrasound of the left hemiscrotum reveals two spherical structures; the one on the left is heterogeneous and hyperdense in comparison to the right.Open in a separate windowFigure 2Doppler ultrasound of left hemiscrotum. No evidence of blood flow to left spherical structure.The patient was taken to the operating room for immediate scrotal exploration. A normalappearing left testicle with a normal epididymis was noted. However, two accessory structures were noted, one of which was torsed 720°; (Figure 3). An inguinal incision was then made and a third accessory structure was noted. All three structures were connected with fibrous tissue, giving a “rosary bead” appearance. The left accessory structures were removed, a left testicular biopsy was taken, and bilateral scrotal orchipexies were performed.Open in a separate windowFigure 3Torsed accessory spleen with splenogonadal fusion.Pathology revealed a normal left testicle with a fibrovascular cord with three nodules consistent with splenic tissue. The torsed splenule demonstrated hemorrhage with neutrophillic infiltrate and thrombus consistent with chronic infarction and torsion (Figure 4).Open in a separate windowFigure 4Splenogonadal fusion, continuous type with three accessory structures.     

Teaching cases: A patient with loss of vision in the right eye and neurofibromatosis type 1

Abstract: Neurofibromatosis type 1 is a common autosomal dominant condition that affects about 1 in 5000 people. We describe a 75-year-old man who, in addition to many classic developmental changes of the disease in his skin, eyes and nervous system, had blindness in his right eye as a complication.Case: A 75-year-old man with long-standing neurofibromatosis type 1 was admitted because the vision in his right eye had decreased progressively over 3 months. Physical examination showed disseminated cutaneous and subcutaneous neurofibromas of varying size (Figure 1) and café-au-lait spots (Figure 2). The patient had a visual acuity of 6/18 (20/60) in his right eye and Lisch nodules (iris hamartomas) (Figure 3). A neurologic examination showed no abnormalities other than his loss of vision. Axial T₁-weighted magnetic resonance imaging of the brain and orbits (Figure 4) showed an isointense mass lateral to the right optic nerve that appeared atrophic and pushed to the left. The mass showed a hyperintense signal on T₂-weighted images with contrast enhancement. These findings are compatible with glioma of the optic nerve.Open in a separate windowFigure 1: Disseminated cutaneous and subcutaneous neurofibromas of varying size on the torso of a patient with neurofibromatosis type 1.Open in a separate windowFigure 2: A café-au-lait spot on the patient''s right knee.Open in a separate windowFigure 3: Lisch nodules on the left iris.Open in a separate windowFigure 4: T₁-weighted axial magnetic resonance imaging of the brain and orbits, showing an isointense mass lateral to the right optic nerve (white arrow) that appears atrophic and pushed to the left (black arrow on inset).Axial and coronal magnetic resonance imaging (Figure 5) showed a mass in the left parietal lobe with hyperintensity on T₂-weighted images and hypointensity on T₁-weighted images. After a contrast medium was administered, the lesion showed a thickened, enhanced wall with a central necrotic area. These findings are compatible with astrocytoma.Open in a separate windowFigure 5: T₂-weighted axial (left) and coronal (right) magnetic resonance imaging showing a mass with hyperintensity (arrow) in the left temporal lobe. After administration of a contrast medium, the lesion is visible with a thickened enhanced wall and a central necrotic area.Because of slight enlargement and increased hardness of the subcutaneous lesions, an excisional biopsy was performed. Histology showed delicate fascicles consisting of cells with oval or spindle-shaped nuclei, scant cytoplasm and round cells with entrapped axons (Figure 6). Only scattered neoplastic Schwann cells were stained during immunostaining for S-100 protein (Figure 7). This pattern is consistent with neurofibroma. The patient chose not to receive further treatment and was discharged.Open in a separate windowFigure 6: Biopsy specimen of a subcutaneous neurofibroma showing spindle-shaped and round cells with entrapped axons (hematoxylin and eosin, original magnification ×10).Open in a separate windowFigure 7: Only scattered neoplastic Schwann cells (arrow) are stained after immunostaining for S-100 protein. Normally, S-100 protein is present in cells derived from the neural crest, such as Schwann cells. It can be found in melanoma cells, in malignant peripheral nerve sheath tumours and in certain types of sarcomas.Neurofibromatosis type 1, also known as von Recklinghausen disease,¹ is characterized by changes in pigmentation and the growth of tumours along nerves in the skin and other parts of the body. It is caused by a defect in a tumour-suppressing gene on chromosome 17q11.2. Normally the gene produces neurofibromin, a protein that regulates cellular proliferation.² With the gene mutation, the lack of neurofibromin results in overgrowth of cells from neural crest areas in both the central nervous system (causing Schwann cell tumours on virtually every nerve) and the skin. All people who inherit a copy of the mutated gene are affected. As the pattern of inheritance is autosomal dominant, only 1 copy of the defective gene is needed to cause the condition. However, it is not necessary to have an affected parent. About 30%–50% of patients have a new mutation.Neurofibromatosis type 2 is a much rarer form of neurofibromatosis caused by mutations in both alleles of a different tumour suppressor gene on chromosome 22q12.1.About 1 in 3000–5000 individuals are affected by neurofibromatosis type 1, without differences related to ethnic background.³ Pigmented small macules and café-au-lait patches are often present shortly after birth, although neurofibromas are rare in early childhood. In later childhood and adolescence, both neurofibromas and pigmented lesions become common. Clinical manifestations are variable (4Table 1Open in a separate windowA diagnosis of neurofibromatosis type 1 is based on clinical findings. The patient should have 2 or more of the following: 6 or more café-au-lait spots of ≥ 1.5 cm in postpubertal individuals or ≥ 0.5 cm in prepubertal individuals; 2 or more neurofibromas of any type or 1 or more plexiform neurofibroma; and freckling in the underarms and groin.¹ The differential diagnosis includes benign café-au-lait pigmentation (present in up to 10% of the general population), multiple lipomas, and sporadic schwannomas, gliomas and meningiomas in the central nervous system.Most people with mild neurofibromatosis have little disability. People affected by more severe variants have a shortened life expectancy, especially if tumours of the central nervous system or other malignant neoplasms arise during the course of illness.^1,3 The condition can have a serious psychological impact because the accumulation of skin nodules can be quite disfiguring.⁵ Surgical excision and laser treatment of the neurofibromas are possible, but neither treatment is universally effective.⁶ Transplantation with an allograft of composite tissue on the lower and middle parts of a patient''s face was recently reported.⁷Gliomas of the optic nerve are found in up to 15% of pediatric patients with neurofibromatosis type 1. Best detected using magnetic resonance imaging, these gliomas are symptomatic in about 50% of patients at diagnosis. A minority will progress to vision loss.⁸ The high prevalence of gliomas of the optic nerve that are asymptomatic may, however, be biased by referral patterns, Indeed, in patients with neurofibromatosis type 1, the threshold of risk for optic nerve glioma is low.⁹Guidelines are available for the diagnosis and management of neurofibromatosis type 1.^10,11 Physicians who identify patients with neurofibromatosis type 1 should refer them early to facilities where appropriate evaluation and monitoring of lesions can be carried out. Early detection and monitoring may help to prevent disability and death.     

Computational Analysis of Human Adenovirus Type 22 Provides Evidence for Recombination among Species D Human Adenoviruses in the Penton Base Gene

Recombination in human adenoviruses (HAdV) may confer virulence upon an otherwise nonvirulent strain. The genome sequence of species D HAdV type 22 (HAdV-D22) revealed evidence for recombination with HAdV-D19 and HAdV-D37 within the capsid penton base gene. Bootscan analysis demonstrated that recombination sites within the penton base gene frame the coding sequences for the two external hypervariable loops in the protein. A similar pattern of recombination was evident within other HAdV-D types but not other HAdV species. Further study of recombination among HAdVs is needed to better predict possible recombination events among wild-type viruses and adenoviral gene therapy vectors.Adenoviruses were first isolated in 1953 (18, 31) and currently cause an array of human diseases. These include respiratory, gastrointestinal, and ocular surface infections, opportunistic infections in immune-deficient individuals, and possibly, obesity (9, 13, 14, 20, 40). Adenoviruses have also recently been used as gene therapy vectors (19, 35). Thus, while adenoviruses continue to cause significant morbidity and mortality in the human population, their existence also provides a potential benefit for the treatment of patients with an even broader range of ailments.Since the characterization of the first human adenovirus (HAdV), 53 types have been identified and subsequently classified into seven species (A to G) on the basis of serology, restriction endonuclease digestion patterns, and to a lesser degree, genotyping. Recently, high-throughput sequencing technology has made whole-genome sequencing both rapid and affordable (27). However, the genomic sequences of 23 out of 53 HAdV types remain to be determined, with most of those within species D.Species D HAdV type 22 (HAdV-D22) was originally isolated from a child in 1956 (3). While it is not clear what role HAdV-D22 plays in human disease, one report revealed a possible tropism for the eye (32). Recently, recombination with HAdV-D22 has been identified as the source of a novel HAdV, HAdV-D53, causing an outbreak of keratoconjunctivitis in Germany (37). HAdV-D22 recombination was also identified in a possible variant of HAdV-D53 that was isolated from a patient in Japan (2). Therefore, HAdV-D22 has shown the propensity to recombine with other viruses, with clinically important consequences. The emergence of new pathogenic HAdV genotypes, along with continued interest in HAdVs as vectors for human gene therapy, make adenovirus recombination a critically important issue.HAdV-D22 was acquired from the American Type Culture Collection (Manassas, VA). The complete genome of the prototype strain AV-2711 (ATCC VR-1100) was sequenced on an Applied Biosystems (Foster City, CA) 3730 XL DNA sequencer in the Laboratory for Genomics and Bioinformatics at the University of Oklahoma Health Sciences Center using a previously described protocol (29). The sequence was validated by sequencing on an ABI SOLiD DNA sequencer. Sequences from both methodologies were 100% identical and provided 7,727-fold coverage for the genome.The mVISTA Limited Area Global Alignment of Nucleotides (LAGAN) tool (http://genome.lbl.gov/vista/index.shtml) was used to align and compare the whole HAdV genomes (6) of HAdV-D22 and each of the other nine completely sequenced HAdV-Ds. Analysis revealed sequence diversity in the penton base, hexon, E3, and fiber open reading frames (Fig. ​(Fig.1).1). Surprisingly, comparison of HAdV-D22 to HAdV-D19 strain C (30) and HAdV-D37 (29) revealed considerable sequence conservation in the penton base gene (Fig. ​(Fig.11 and 2A and B).Open in a separate windowFIG. 1.Global pairwise sequence alignment of HAdV-D22 with nine other HAdV-D types. The percent sequence conservation is reflected in the height of each data point along the y axis. A conserved sequence in the penton base open reading frame is designated by an asterisk. GenBank accession numbers are as follows: HAdV-D8, AB448768; HAdV-D9, AJ854486; HAdV-D19, EF121005; HAdV-D26, EF153474; HAdV-D37, DQ900900; HAdV-D46, AY875648; HAdV-D48, EF153473; HAdV-D49, DQ393829; and HAdV-D53, FJ169625.Open in a separate windowFIG. 2.Multisequence alignment of HAdV-D penton base genes. Nucleotide alignment of the bp 397 to 594 (A) and bp 694 to 1089 (B) regions of the penton base gene.Based on the sequence conservation seen in the penton base, Simplot 3.5.1 (http://sray.med.som.jhmi.edu/SCRoftware/simplot/) and Recombination Detection Program (RDP) version 3.34 (http://darwin.uvigo.es/rdp/rdp.html) were used to identify possible recombination sites (21, 24). Bootscan analysis identified two possible recombination loci in the HAdV-D22 penton base, the first in HAdV-D37, encompassing nucleotides 400 to 600, and the second in HAdV-D19 at nucleotides 750 to 1350 (Fig. ​(Fig.3A).3A). In silico amino acid analysis showed that these two probable recombination areas code for the two variable loops in the penton base protein (Fig. ​(Fig.3A),3A), located on the exterior of the viral capsid (16, 44).Open in a separate windowFIG. 3.Bootscan analysis of HAdV-D penton base genes. Comparison of HAdV-D22 (A) with completely sequenced HAdV types. Similar comparisons of the same region were performed with HAdV-D9 (B), HAdV-D49 (C), HAdV-A12 (D), HAdV-B3 (E), HAdV-C2 (F), or HAdV-F41 (G) as the reference type. HAdV-D53 was left out of the analysis due to the 100% identity of its penton base to that of HAdV-D37. The axes of all panels are as labeled in panel A. GenBank accession numbers are as follows: HAdV-A12, NC_001460; HAdV-B3, DQ086466; HAdV-C2, AC_000007; and HAdV-F41, DQ315364.We extended our investigation to determine if these recombination sites were common to penton base genes of other HAdV genomes. We found evidence for recombination between HAdV-D9 and HAdV-D26 in both the nucleotide 400 to 600 and 750 to 1350 regions (Fig. ​(Fig.3B),3B), between HAdV-D49 and HAdV-D48 in the nucleotide 400 to 600 region, and between HAdV-D49 and HAdV-D8 in the nucleotide 750 to 1350 region (Fig. ​(Fig.3C).3C). A similar pattern was observed in one or both of these nucleotide regions for HAdV-D8, -17, -19, -26, -37, and -48 (data not shown). Remarkably, this pattern of recombination in the penton base gene was unique to HAdV species D (Fig. 3D, E, F, and G).Bootstrap-confirmed neighbor-joining phylogenetic trees of HAdV-D penton base genes were constructed with Molecular Evolutionary Genetics Analysis (MEGA) 4.0.2 (http://www.megasoftware.net/index.html) to examine viral evolution in HAdV-D (34). Analysis of the entire penton gene revealed a close relationship of HAdV-D22 and HAdV-D19 strain C (Fig. ​(Fig.4A)4A) (30). Additional phylogenetic trees were constructed to encompass the two proposed recombination sites within this gene. Phylogenetic analysis of the nucleotide 400 to 600 region revealed a close identity among HAdV-D22, HAdV-D37, and HAdV-D53 (Fig. ​(Fig.4B).4B). Analysis of the nucleotide 750 to 1350 region of the penton base gene revealed a close identity of HAdV-D22 and HAdV-D19 (Fig. ​(Fig.4C4C).Open in a separate windowFIG. 4.Phylogenetic analysis of HAdV-D penton base genes. Bootstrap neighbor-joining tree designed using MEGA 4.0.2. The Gonnet protein weight matrix in ClustalX alignment was used, along with complete deletion options. Percent bootstrap confidence levels (1,000 replicates) are shown on the relevant branches. (A) Analysis of sequenced HAdV-D penton base genes. (B) Analysis of the nucleotide 400 to 600 region of sequenced HAdV-D penton base genes. (C) Analysis of the nucleotide 750 to 1350 region of sequenced HAdV-D penton base genes.In summary, comparison of the HAdV-D22 genome to other sequenced HAdV-D genomes identified substantial sequence divergence in the penton, hexon, E3, and fiber open reading frames. Differences between HAdV-D genomes in these areas have previously been described by us in reports on HAdV-D19 strain C and HAdV-D37 genomes (29, 30). However, the sequence conservation among HAdV-D22, HAdV-D19, and HAdV-D37 in the penton base gene was unexpected and suggests recombination among these viruses. Bootscan analysis identified recombination events at two regions within the penton base gene, encompassing nucleotides 400 to 600 and 750 to 1350. Further analysis of other HAdV-D penton genes suggests that these areas represent hot spots for recombination.The propensity for recombination among different HAdV-Ds in the penton base gene can be understood in the context of penton base function. The adenovirus penton base acts as the ligand for a secondary attachment event that is critical to host cell internalization (38) and thus is critical to infection. The penton base protein contains two hypervariable loops located on the surface of the viral capsid (16, 44). One loop contains the host cell integrin binding Arg-Gly-Asp (RGD) motif mediating attachment to host cell integrins (8, 38). The RGD motif is conserved in almost every HAdV penton base protein, with the exception of HAdV-F40 and HAdV-F41, which do not use host cell integrins for internalization (1, 11). The second exterior loop, known as the variable loop (HVL1), has no known function. Both of these regions are highly variable among different HAdV types. We identified recombination around both of these loops for multiple viruses within HAdV-D (Fig. ​(Fig.3A3A).In recent epidemiological studies, patients were identified with coincident clinical infections with two or more adenovirus types (17, 36). Simultaneous infection by more than a single HAdV type is possible because of conserved host receptor affinity, common tissue tropisms, and an absence of immunity across serotypes. Our data, along with evidence from previous studies (22, 23, 37, 43), identified recombination events among viruses with similar tissue tropisms, providing evidence that the restriction of tissue tropism might determine in part the observed recombination within adenoviruses of the same species. Recently, a novel HAdV, HAdV-D53, was isolated from an outbreak of keratoconjunctivitis. Subsequent analysis revealed recombination among HAdV-D22, HAdV-D37, HAdV-D8, and a previously unknown adenoviral sequence, suggesting the potential for the emergence of new pathogens, with important ramifications for human disease.Previous work provides evidence for recombination in HAdVs (10, 12, 22, 25, 26, 37, 39, 41-43), but the mechanisms of recombination have yet to be identified. Recombination may result from selective pressure from the host immune system relative to surface capsid proteins, a nucleotide motif that directs cellular recombination machinery to the local sites on the viral DNA, or a combination of both. Two eukaryotic recombinases, RAD51 and Dmc1, both homologues of the bacterial recombinase RecA, act in host cell DNA recombination (5, 33). RAD51 mediates recombination during mitosis, while Dmc1 acts during meiosis. RAD51 is of potential interest because it colocalizes with promyelocytic leukemia nuclear bodies in the nucleus (4). Adenoviral proteins E1A and E4 Orf3 have been shown to interact with promyelocytic leukemia nuclear bodies, which play an important role in adenoviral replication (7, 15). An interaction between RAD51 and adenoviral DNA has not been studied. A proposed motif consisting of CCNCCNTNNCCNC was recently identified as being associated with loci of recombination and genome instability in humans (28). Although not present in the viruses we studied, sequencing of other viruses within HAdV-D may yet reveal a consensus site for recombination. The elucidation of recombination mechanisms for HAdVs should allow a better understanding of adenoviral evolution.In conclusion, our analysis of the penton base gene of HAdV-D identified a potential paradigm for adenovirus recombination and the emergence of pathogenic strains. An in depth understanding of adenovirus recombination and evolution is critical to ensure the safety of adenoviral gene therapy.     

Spotlight on Zebrafish: Translational Impact

In recent years, the zebrafish has emerged as an increasingly prominent model in biomedical research. To showcase the translational impact of the model across multiple disease areas, Disease Models & Mechanisms has compiled a Special Issue that includes thought-provoking reviews, original research reporting new and important insights into disease mechanisms, and novel resources that expand the zebrafish toolkit. This Editorial provides a summary of the issue’s contents, highlighting the diversity of zebrafish disease models and their clinical applications.Open in a separate windowE. Elizabeth PattonOpen in a separate windowJames F. AmatrudaOpen in a separate windowLalita Ramakrishnan     

Gold for Ubiquitin in Vancouver: FIRST CONFERENCE ON PROTEOMICS OF PROTEIN DEGRADATION AND UBIQUITIN PATHWAYS HELD JUNE 6–8, 2010 IN VANCOUVER,UNIVERSITY OF BRITISH COLUMBIA,ORGANIZED BY LAN HUANG,THIBAULT MAYOR,AND PEIPEI PING*

The rise of proteomics has had tremendous influence on analysis and understanding of the role of post-translational modifications in biological processes. The covalent attachment of small proteins like ubiquitin, SUMO,1 or other ubiquitin-like proteins (Ubls) is one class of post-translational modifications where proteomics has had notable impact. Various proteomics approaches, but in particular mass spectrometry-based analyses, have influenced the field and enabled significant advances over the past few years. The first meeting dedicated to proteomics of protein degradation and ubiquitin pathways showcased these advances and allowed a glimpse at future contributions of proteomics to this field. With its many attractive drug targets, the ubiquitin and proteasome system, as well as other proteolysis pathways, could offer new therapies for various human diseases including cancer and neurodegenerative disorders.The covalent linkage of ubiquitin to other proteins is catalyzed by the E1-E2-E3 cascade of enzymatic reactions whereby the many different E3 ubiquitin ligases provide substrate specificity to the process of protein ubiquitylation (1). Ubiquitylation is best known for targeting proteins for degradation by the proteasome, but other functions for ubiquitylation independent of proteolysis are also known. Likewise, modifications with SUMO or other Ubls generally do not regulate protein degradation but instead control subcellular localization, protein interactions, or change protein conformation and activity (2).The questions addressed by proteomics approaches to ubiquitylation and Ubl modifications are plentiful. They range from very specific, e.g. determination of the modified residue in a substrate protein, to complex, such as protein dynamics in proteome-wide ubiquitin (or Ubl) modification profiles (3). In either case, the rapid technological advancements (particularly in mass spectrometry instrumentation as well as quantitation and separation technologies) have allowed impressive progress, which was evident in the First Conference on Proteomics of Protein Degradation and Ubiquitin Pathways in Vancouver (http://ppdup.org/) (Fig. 1).Open in a separate windowFig. 1.Group picture from First Conference on Proteomics of Protein Degradation and Ubiquitin Pathways held June 6–8, 2010 in Vancouver (http://ppdup.org/).