A Rational Approach to JAK2 Mutation Testing in Patients with Elevated Hemoglobin: Results from the JAK2 Prediction Cohort (JAKPOT) Study.

BACKGROUND: Erythrocytosis, most often measured as an increase in hemoglobin and/or hematocrit, is a common reason for referral to internal medicine and hematology clinics and a rational approach is required to effectively identify patients with polycythemia vera while avoiding over-investigation. AIM: We aimed to develop and validate a simple rule to predict JAK2 mutation positivity based on complete blood count parameters to aid in the diagnostic approach to patients referred for elevated hemoglobin. SETTING: Internal medicine and hematology clinics at an academic tertiary referral center. PARTICIPANTS: The JAK2 Prediction Cohort (JAKPOT), a large retrospective cohort (n = 901) of patients evaluated by internal medicine and hematology specialists for elevated hemoglobin. DESIGN: JAK2 mutation analysis was performed in all patients and clinical and laboratory variables were collected. Patients were randomly divided into derivation and validation cohorts. A prediction rule was developed using data from the derivation cohort and tested in the validation cohort. KEY RESULTS: The JAKPOT prediction rule included three variables: (i) red blood cell count >6.45×1012/L, (ii) platelets >350×109/L, and (iii) neutrophils >6.2×109/L; absence of all criteria was effective at ruling out JAK2-positivity with sensitivities 94.7% and 100%, and negative predictive values of 98.8% and 100% in the derivation and validation cohorts, respectively, with an overall low false negative rate of 0.4%. The rule was validated for three different methods of JAK2 testing. Applying this rule to our entire cohort would have resulted in over 50% fewer tests. CONCLUSION: In patients with elevated hemoglobin, the use of a simple prediction rule helps to accurately identify patients with a low likelihood of having a JAK2 mutation, potentially limiting costly over-investigation in this common referral population.

Defining the Intravital Renal Disposition of Fluorescence-Quenched Exenatide.

Despite the understanding that renal clearance is pivotal for driving the pharmacokinetics of numerous therapeutic proteins and peptides, the specific processes that occur following glomerular filtration remain poorly defined. For instance, sites of catabolism within the proximal tubule can occur at the brush border, within lysosomes following endocytosis, or even within the tubule lumen itself. The objective of the current study was to address these limitations and develop methodology to study the kidney disposition of a model therapeutic protein. Exenatide is a peptide used to treat type 2 diabetes mellitus. Glomerular filtration and ensuing renal catabolism have been shown to be its principal clearance pathway. Here, we designed and validated a Förster resonance energy transfer-quenched exenatide derivative to provide critical information on the renal handling of exenatide. A combination of in vitro techniques was used to confirm substantial fluorescence quenching of intact peptide that was released upon proteolytic cleavage. This evaluation was then followed by an assessment of the in vivo disposition of quenched exenatide directly within kidneys of living rats via intravital two-photon microscopy. Live imaging demonstrated rapid glomerular filtration and identified exenatide metabolism occurred within the subapical regions of the proximal tubule epithelia, with subsequent intracellular trafficking of cleaved fragments. These results provide a novel examination into the real-time, intravital disposition of a protein therapeutic within the kidney and offer a platform to build upon for future work.

Technical Difficulties: Teaching Critical Philosophical Orientations toward Technology.

Issue: Technological innovation is accelerating, creating less time to reflect on the impact new technologies will have on the medical profession. Modern technologies are becoming increasingly embedded in routine medical practice with far-reaching impacts on the patient-physician relationship and the very essence of the health professions. These impacts are often difficult to predict and can create unintended consequences for medical education. This article is driven by a main question: How do we prepare trainees to critically assess technologies that we cannot foresee and effectively use technology to support equitable and compassionate care? Evidence: We translate insights from the philosophy of technology into a proposal for integrating critical technical consciousness in medical curricula. We identify three areas required to develop critical consciousness with regard to emerging technologies. The first area is technical literacy, which involves not just knowing how to use technology, but also understanding its limitations and appropriate contexts for use. The second area is the ability to assess the social impact of technology. This practice requires understanding that while technification creates new possibilities it can also have adverse, unintended consequences. The third area is critical reflection on the relationship between 'the human' and 'the technical' as it relates to the values of the medical profession and professional identity formation. Human and technology are two sides of the same coin; therefore, thinking critically about technology also forces us to think about what we consider 'the human side of medicine'. Implications: Critical technical consciousness can be fostered through an educational program underpinned by the recognition that, although technological innovation can create new possibilities for healing, technology is never neutral. Rather, it is imperative to emphasize that technology is interwoven with the social fabric that is essential to healing. Like medication, technology can be both potion and poison.

Thirty years of teaching evidence-based medicine: have we been getting it all wrong?

Evidence based medicine (EBM) has been synonymous to delivery of quality care for almost thirty years. Since the movement's inception, the assumption has been that decisions based on high quality evidence would translate to better care for patients. Despite EBM's many attractive features and the substantive attention it has received in the contemporary clinical and medical education literature, how it is defined and operationalized as a component of training is often unclear and problematic. How to practice EBM is not well articulated in the literature; therefore, it becomes difficult to teach and equally challenging to assess. In this paper, we put forward a call for deeper consideration of how EBM is taught, and for clarification on how it is defined and operationalized in medical education. In preparing this paper, we considered questions such as what it means to practice EBM, the role that medical education plays in helping realize EBM, how the teaching of EBM can change to reflect recent developments in clinical practice and education, and whether transformations in the practice of medicine necessitate a change in how we teach EBM. We end with four avenues that may be pursued to advance the teaching of EBM in medical education: (1) consensus on what we mean by EBM; (2) clear articulation of EBM-associated competencies; (3) empirically and theoretically supported means of promoting EBM competencies; (4) ways to assess both skill acquisition and use of EBM. We discuss implications for educators of EBM.

The Impact of Artificial Intelligence on Health Equity in Oncology: Scoping Review.

BACKGROUND: The field of oncology is at the forefront of advances in artificial intelligence (AI) in health care, providing an opportunity to examine the early integration of these technologies in clinical research and patient care. Hope that AI will revolutionize health care delivery and improve clinical outcomes has been accompanied by concerns about the impact of these technologies on health equity. OBJECTIVE: We aimed to conduct a scoping review of the literature to address the question, "What are the current and potential impacts of AI technologies on health equity in oncology?" METHODS: Following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines for scoping reviews, we systematically searched MEDLINE and Embase electronic databases from January 2000 to August 2021 for records engaging with key concepts of AI, health equity, and oncology. We included all English-language articles that engaged with the 3 key concepts. Articles were analyzed qualitatively for themes pertaining to the influence of AI on health equity in oncology. RESULTS: Of the 14,011 records, 133 (0.95%) identified from our review were included. We identified 3 general themes in the literature: the use of AI to reduce health care disparities (58/133, 43.6%), concerns surrounding AI technologies and bias (16/133, 12.1%), and the use of AI to examine biological and social determinants of health (55/133, 41.4%). A total of 3% (4/133) of articles focused on many of these themes. CONCLUSIONS: Our scoping review revealed 3 main themes on the impact of AI on health equity in oncology, which relate to AI's ability to help address health disparities, its potential to mitigate or exacerbate bias, and its capability to help elucidate determinants of health. Gaps in the literature included a lack of discussion of ethical challenges with the application of AI technologies in low- and middle-income countries, lack of discussion of problems of bias in AI algorithms, and a lack of justification for the use of AI technologies over traditional statistical methods to address specific research questions in oncology. Our review highlights a need to address these gaps to ensure a more equitable integration of AI in cancer research and clinical practice. The limitations of our study include its exploratory nature, its focus on oncology as opposed to all health care sectors, and its analysis of solely English-language articles.

Paralogization and New Protein Architectures in Planctomycetes Bacteria with Complex Cell Structures.

Bacteria of the phylum Planctomycetes have a unique cell plan with an elaborate intracellular membrane system, thereby resembling eukaryotic cells. The origin and evolution of these remarkable features is debated. To study the evolutionary genomics of bacteria with complex cell architectures, we have resequenced the 9.2-Mb genome of the model organism Gemmata obscuriglobus and sequenced the 10-Mb genome of G. massiliana Soil9, the 7.9-Mb genome of CJuql4, and the 6.7-Mb genome of Tuwongella immobilis, all of which belong to the family Gemmataceae. A gene flux analysis of the Planctomycetes revealed a massive emergence of novel protein families at multiple nodes within the Gemmataceae. The expanded protein families have unique multidomain architectures composed of domains that are characteristic of prokaryotes, such as the sigma factor domain of extracytoplasmic sigma factors, and domains that have proliferated in eukaryotes, such as the WD40, leucine-rich repeat, tetratricopeptide repeat and Ser/Thr kinase domains. Proteins with identifiable domains in the Gemmataceae have longer lengths and linkers than proteins in most other bacteria, and the analyses suggest that these traits were ancestrally present in the Planctomycetales. A broad comparison of protein length distribution profiles revealed an overlap between the longest proteins in prokaryotes and the shortest proteins in eukaryotes. We conclude that the many similarities between proteins in the Planctomycetales and the eukaryotes are due to convergent evolution and that there is no strict boundary between prokaryotes and eukaryotes with regard to features such as gene paralogy, protein length, and protein domain composition patterns.

The impact of video gaming on cognitive functioning of people with schizophrenia (GAME-S): study protocol of a randomised controlled trial.

BACKGROUND: Video gaming is a promising intervention for cognitive and social impairment in patients with schizophrenia. A number of gaming interventions have been evaluated in small-scale studies with various patient groups, but studies on patients with schizophrenia remain scarce and rarely include the evaluation of both clinical and neurocognitive outcomes. In this study, we will test the effectiveness of two interventions with gaming elements to improve cognitive and clinical outcomes among persons with schizophrenia. METHODS: The participants will be recruited from different outpatient units (e.g., outpatient psychiatric units, day hospitals, residential care homes). The controlled clinical trial will follow a three-arm parallel-group design: 1) cognitive training (experimental group, CogniFit), 2) entertainment gaming (active control group, SIMS 4), and 3) treatment as usual. The primary outcomes are working memory function at 3-month and 6-month follow-ups. The secondary outcomes are patients' other cognitive and social functioning, the ability to experience pleasure, self-efficacy, and negative symptoms at 3-month and 6-month follow-ups. We will also test the effectiveness of gaming interventions on neurocognitive outcomes (EEG and 3 T MRI plus rs-fMRI) at a 3-month follow-up as an additional secondary outcome. Data will be collected in outpatient psychiatric services in Hong Kong. Participants will have a formal diagnosis of schizophrenia and be between 18 and 60 years old. We aim to have a total of 234 participants, randomly allocated to the three arms. A sub-sample of patients (N = 150) will be recruited to undergo an EEG. For neuroimaging assessment, patients will be randomly allocated to a subset of patients (N=126). We will estimate the efficacy of the interventions on the primary and secondary outcomes based on the intention-to-treat principle. Behavioural and EEG data will be analysed separately. DISCUSSION: The study will characterise benefits of gaming on patients' health and well-being, and contribute towards the development of new treatment approaches for patients with schizophrenia. TRIAL REGISTRATION: ClinicalTrials.gov NCT03133143 . Registered on April 28, 2017.

Small lesions of the dorsal or ventral hippocampus subregions are associated with distinct impairments in working memory and reference memory retrieval, and combining them attenuates the acquisition rate of spatial reference memory.

The importance of the hippocampus in spatial learning is well established, but the precise relative contributions by the dorsal (septal) and ventral (temporal) subregions remain unresolved. One debate revolves around the extent to which the ventral hippocampus contributes to spatial navigation and learning. Here, separate small subtotal lesions of dorsal hippocampus or ventral hippocampus alone (destroying 18.9 and 28.5% of total hippocampal volume, respectively) spared reference memory acquisition in the water maze. By contrast, combining the two subtotal lesions significantly reduced the rate of acquisition across days. This constitutes evidence for synergistic integration between dorsal and ventral hippocampus in mice. Evidence that ventral hippocampus contributes to spatial/navigation learning also emerged early on during the retention probe test as search preference was reduced in mice with ventral lesions alone or combined lesions. The small ventral lesions also led to anxiolysis in the elevated plus maze and over-generalization of the conditioned freezing response to a neutral context. Similar effects of comparable magnitudes were seen in mice with combined lesions, suggesting that they were largely due to the small ventral damage. By contrast, small dorsal lesions were uniquely associated with a severe spatial working memory deficit in the water maze. Taken together, both dorsal and ventral poles of the hippocampus contribute to efficient spatial navigation in mice: While the integrity of dorsal hippocampus is necessary for spatial working memory, the acquisition and retrieval of spatial reference memory are modulated by the ventral hippocampus. Although the impairments following ventral damage (alone or in combination with dorsal damage) were less substantial, a wider spectrum of spatial learning, including context conditioning, was implicated. Our results encourage the search for integrative mechanism between dorsal and ventral hippocampus in spatial learning. Candidate neural substrates may include dorsoventral longitudinal connections and reciprocal modulation via overlapping polysynaptic networks beyond hippocampus.

Genomic data in prognostic models-what is lost in translation? The case of deletion 17p and mutant TP53 in chronic lymphocytic leukaemia.

Genomic technologies are revolutionizing the practice of haematology-oncology, leading to improved disease detection, more accurate prognostication and targeted treatment decisions. These advances, however, have also introduced new clinical challenges, which include problems of prognostic underdetermination and its attendant risks of over- and undertreatment. Genomic data is generated from different technologies, from cytogenetics to next-generation sequencing, which are often interpreted interchangeably and in a binary fashion-as the presence or absence of a given chromosomal deletion or mutation-an oversimplification which may lead to mistaken prognosis. We discuss the clinical use of one such prognostic marker, represented by sequence and copy number alterations in TP53, located on chromosome 17p. Mutations in TP53 are strongly linked to poor prognosis in a variety of haematological malignancies, including chronic lymphocytic leukaemia (CLL). We review studies in CLL which utilize the 17p deletion or TP53 mutations for prognostic stratification with specific focus on the technologies used for detection, the thresholds established for clinical significance, and the clinical contexts in which these alterations are identified. The case of CLL illustrates issues arising from simplistic, binary interpretation of genetic testing and highlights the need to apply a critical lens when incorporating genomics into prognostic models.

Megalin-mediated albumin endocytosis in cultured murine mesangial cells.

Endocytosis by podocytes is gaining increased attention as a biologic means of removing large proteins such as serum albumin from the glomerular barrier. Some of this function has been attributed to the megalin/cubilin (Lrp2/Cubn) receptor complex and the albumin recycling protein FcRn (Fcgrt). However, whether other glomerular cells possess the potential to perform this same phenomenon or express these proteins remains uncharacterized. Mesangial cells are uniquely positioned in glomeruli and represent a cell type capable of performing several diverse functions. Here, the expression of megalin and FcRn in murine mesangial cells along with the megalin adaptor protein Dab-2 (Dab2) was shown for the first time. Cubilin mRNA expression was detected, but the absence of the cubilin partner amnionless (Amn) suggested that cubilin is minimally functional, if at all, in these cells. Mesangial cell endocytosis of albumin was characterized and shown to involve a receptor-mediated process. Albumin endocytosis was significantly impaired (p < 0.01) under inducible megalin knockdown conditions in stably transduced mesangial cells. The current work provides both the novel identification of megalin and FcRn in mesangial cells and the functional demonstration of megalin-mediated albumin endocytosis.

The Protective Impact of Telemedicine on Persons With Dementia and Their Caregivers During the COVID-19 Pandemic.

OBJECTIVES: Social distancing under the COVID-19 pandemic has restricted access to community services for older adults with neurocognitive disorder (NCD) and their caregivers. Telehealth is a viable alternative to face-to-face service delivery. Telephone calls alone, however, may be insufficient. Here, we evaluated whether supplementary telehealth via video-conferencing platforms could bring additional benefits to care-recipient with NCD and their spousal caregivers at home. PARTICIPANTS: Sixty older adults NCD-and-caregiver dyads were recruited through an activity center. DESIGN, INTERVENTION: The impact of additional services delivered to both care-recipient and caregiver through video conference (n = 30) was compared with telehealth targeted at caregivers by telephone only (n = 30), over 4 weeks in a pretest-post-test design. Interviews and questionnaires were conducted at baseline and study's end. MEASUREMENTS, RESULTS: Supplementary telemedicine had averted the deterioration in the Montreal Cognitive Assessment evident in the telephone-only group (ηp2 = 0.50). It also reversed the falling trend in quality of life observed in the telephone only group (QoL-AD, ηp2 = 0.23). Varying degrees of improvements in physical and mental health (Short-Form 36 v2), perceived burden (Zarit Burden Interview Scale) and self-efficacy (Revised Caregiving Self-Efficacy Scale) were observed among caregivers in the video-conferencing group, which were absent in the telephone-only group (ηp2 = 0.23-0.51). CONCLUSION: Telemedicine by video conference was associated with improved resilience and wellbeing to both people with NCD and their caregivers at home. The benefits were visible already after 4 weeks and unmatched by telephone alone. Video conference as the modus operandi of telehmedicine beyond the context of pandemic-related social distancing should be considered.

From hermeneutics to heteroglossia: 'The Patient's View' revisited.

This article explores conceptual and methodological challenges surrounding the recovery of patients' voices in the history of medicine. We examine the debate that followed Roy Porter's seminal article, 'The Patient's View: Doing Medical History from Below' (1985). Porter argued that patients should be given a central role in medical history, aiming to restore to patients a voice and agency that is often lost in 'physician-centered' historical narratives. His work carried significant influence but also sparked an ongoing debate about the possibility of conducting 'patient-centered' history of medicine. The growth of the medical humanities has afforded renewed attention to patient narratives, supporting the need to recognise patients' voices in contemporary healthcare and medical education. However, several barriers complicate and problematise the expansion of a patient-centred epistemology across historical periods. Postmodern critics have expressed scepticism that 'the patient's view' can be recovered from history, with some claiming that 'the patient' is a construct of the 'medical gaze' whose subjectivity cannot be reconstituted outside of sociohistorical discourses of knowledge and power. Psychiatry in the mid-20th century presents a particular challenge for patient-centred history. We discuss the influence of postmodern theorists, especially Michel Foucault, whose work is seen as undermining the possibility of a patient-centred epistemology. We argue against Foucault's erasure of the patient, and instead explore alternate constructivist epistemologies, focusing on the hermeneutics of Hans-Georg Gadamer and dialogism of Mikhail Bakhtin, to help address historiographical challenges in recovering 'the patient's view'. To illustrate the value of Gadamerian and Bakhtinian approaches, we apply them to a case study from the Verdun Protestant Hospital (Québec, Canada) from 1941 to 1956, which sheds light on the introduction of the first antipsychotic, chlorpromazine, into clinical practice. We highlight how Gadamer's hermeneutics and Bakhtin's dialogism together offer insights into patient perspectives during this liminal period in the history of psychiatry.

Exosomes in Inflammation and Inflammatory Disease.

Exosomes are a subset of extracellular vesicles released by all cell types and involved in local and systemic intercellular communication. In the past decade, research into exosomes has swelled as their important role in the mediation of health and disease has been increasingly established and acknowledged. Exosomes carry a diverse range of cargo including proteins, nucleic acids, and lipids derived from their parental cell that, when delivered to the recipient cell, can confer pathogenic or therapeutic effects through modulation of immunity and inflammation. In this review, the role of exosomes on mediation of immune and inflammatory responses, and their participation in diseases with a significant inflammatory component is discussed. The considerable potential for exosomes in therapy and diagnosis of inflammatory diseases is also highlighted.

Crusted scabies in a renal transplant recipient treated with daily ivermectin: A case report and literature review.

Crusted scabies is a rare disease variant associated with T-cell dysregulation. Transplant patients are at risk of developing crusted scabies as a consequence of their immunosuppressive regimens. We report a case of crusted scabies presenting with recurrent septicemia in a 65-year-old renal transplant recipient, treated with daily ivermectin for 7 days after initial failure of weekly ivermectin dosing. A literature review of crusted scabies in transplant recipients consisting of 19 cases reports was summarized. Pruritus was common, and initial misdiagnosis was frequent. Most were treated with topical therapy, with one-third receiving ivermectin. Three of seven cases presenting with a concomitant infection died. Crusted scabies is commonly misdiagnosed in transplant recipients owing to its rarity, varied appearance, and different skin distributions. It should be considered in the differential diagnosis of transplant recipients presenting with rash and pruritus, given its association with secondary infection and subsequent mortality.

Three visions of doctoring: a Gadamerian dialogue.

Medicine in the twenty-first century faces an 'identity crisis,' as it grapples with the emergence of various 'ways of knowing,' from evidence-based and translational medicine, to narrative-based and personalized medicine. While each of these approaches has uniquely contributed to the advancement of patient care, this pluralism is not without tension. Evidence-based medicine is not necessary individualized; personalized medicine may be individualized but is not necessarily person-centered. As novel technologies and big data continue to proliferate today, the focus of medical practice is shifting away from the dialogic encounter between doctor and patient, threatening the loss of humanism that many view as integral to medicine's identity. As medical trainees, we struggle to synthesize medicine's diverse and evolving 'ways of knowing' and to create a vision of doctoring that integrates new forms of medical knowledge into the provision of person-centered care. In search of answers, we turned to twentieth-century philosopher Hans-Georg Gadamer, whose unique outlook on "health" and "healing," we believe, offers a way forward in navigating medicine's 'messy pluralism.' Drawing inspiration from Gadamer's emphasis on dialogue and 'practical wisdom' (phronesis), we initiated a dialogue with the dean of our medical school to address the question of how medical trainees and practicing clinicians alike can work to create a more harmonious pluralism in medicine today. We propose that implementing a pluralistic approach ultimately entails 'bridging' the current divide between scientific theory and the practical art of healing, and involves an iterative and dialogic process of asking questions and seeking answers.

Three Problems with Big Data and Artificial Intelligence in Medicine.

The rise of big data and artificial intelligence (AI) in health care has engendered considerable excitement, claiming to improve approaches to diagnosis, prognosis, and treatment. Amidst the enthusiasm, the philosophical assumptions that underlie the big data and AI movement in medicine are rarely examined. This essay outlines three philosophical challenges faced by this movement: (1) the epistemological-ontological problem arising from the theory-ladenness of big data and measurement; (2) the epistemological-logical problem resulting from the inherent limitations of algorithms and attendant issues of reliability and interpretability; and (3) the phenomenological problem concerning the irreducibility of human experience to quantitative data. These philosophical issues demonstrate several important challenges for these technologies that must be considered prior to their integration into clinical care. Our article aims to initiate a critical dialogue on the impact of big data and AI in health care in order to allow for more robust evaluation of these technologies and to aid in the development of approaches to clinical care that better serve clinicians and their patients.

Increased megalin expression in early type 2 diabetes: role of insulin-signaling pathways.

The megalin/cubilin complex is responsible for the majority of serum protein reclamation in the proximal tubules. The current study examined if decreases in their renal expression, along with the albumin recycling protein neonatal Fc receptor (FcRn) could account for proteinuria/albuminuria in the Zucker diabetic fatty rat model of type 2 diabetes. Immunoblots of renal cortex samples obtained at worsening disease stages demonstrated no loss in megalin, cubilin, or FcRn, even when proteinuria was measured. Additionally, early diabetic rats exhibited significantly increased renal megalin expression when compared with controls (adjusted P < 0.01). Based on these results, the ability of insulin to increase megalin was examined in a clonal subpopulation of the opossum kidney proximal tubule cell line. Insulin treatments (24 h, 100 nM) under high glucose conditions significantly increased megalin protein ( P < 0.0001), mRNA ( P < 0.0001), and albumin endocytosis. The effect on megalin expression was prevented with inhibitors against key effectors of insulin intracellular signaling, phosphatidylinositide 3-kinase and Akt. Studies using rapamycin to inhibit the mechanistic target of rapamycin complex 1 (mTORC1) resulted in a loss of insulin-induced megalin expression. However, subsequent evaluation demonstrated these effects were independent of initial mTORC1 suppression. The presented results provide insight into the expression of megalin, cubilin, and FcRn in type 2 diabetes, which may be impacted by elevated insulin and glucose. Furthermore, proximal tubule endocytic activity in early diabetics may be enhanced, a process that could have a significant role in proteinuria-induced renal damage.

Emerging Trends in Clinical Research: With Implications for Population Health and Health Policy.

Policy Points: Significant advances in clinical medicine that have broader societal relevance may be less accessible to population health researchers and policymakers because of increased specialization within fields. We describe important recent clinical advances and discuss their broader societal impact. These advances include more expansive strategies for disease prevention, the rise of precision medicine, applications of human microbiome research, and new and highly successful treatments for hepatitis C infection. These recent developments in clinical research raise important issues surrounding health care costs and equitable resource allocation that necessitate an ongoing dialogue among the fields of clinical medicine, population health, and health policy. CONTEXT: Developments in clinical medicine have important implications for population health, and there is a need for interdisciplinary engagement among clinical medicine, the social sciences, and public health research. The aim of this article is to help bridge the divide between these fields by exploring major recent advances in clinical medicine that have important implications for population health. METHODS: We reviewed the most cited articles published from 2010 to 2015 in 5 high-impact clinical journals and selected 5 randomized controlled trials and 2 related clinical practice guidelines that are broadly relevant to population health and policy. FINDINGS: We discuss the following themes: (1) expanding indications for drug therapy and the inherent medicalization of the population as highlighted by studies and clinical guidelines supporting lower blood pressure targets or widespread statin use; (2) the tension in nutritional research between quantifying the impact of isolated nutrients and studying specific foods and dietary patterns, for example, the role of the Mediterranean diet in the primary prevention of cardiovascular disease; (3) the issue of high medication costs and the challenge of providing equitable access raised by the development of new and effective treatments for hepatitis C infection; (4) emerging clinical applications of research on the human microbiome as illustrated by fecal transplant to treat Clostridium difficile infections; and (5) the promise and limitations of precision medicine as demonstrated by the rise of novel targeted therapies in oncology. CONCLUSIONS: These developments in clinical science hold promise for improving individual and population health and raise important questions about resource allocation, the role of prevention, and health disparities.

Blood donation and testosterone replacement therapy.

BACKGROUND: Polycythemia is the most common adverse effect of testosterone replacement therapy (TRT) and may predispose patients to adverse vascular events. Current Canadian guidelines recommend regular laboratory monitoring and discontinuing TRT or reducing the dose if the hematocrit exceeds 54% (hemoglobin ≥180 g/L). This threshold has been interpreted by some physicians and patients to indicate the need for phlebotomy or blood donation while on TRT. STUDY DESIGN AND METHODS: We reviewed all male blood donors in Southwestern Ontario at Canadian Blood Services from December 2013 to March 2016 who self-identified or were found on donor screening to be on TRT. Hemoglobin concentration was measured at the time of donation or clinic visit and with each subsequent appointment in repeat donors. RESULTS: We identified 39 patients on TRT who presented for blood donation over a 2-year period. The mean hemoglobin level at all clinic visits was 173 g/L (range, 134-205 g/L; n = 108). Hemoglobin concentrations of 180 g/L or more (calculated hematocrit, ≥54%) were measured at 25% of appointments. Of the 27 repeat donors, 12 (44%) had persistently elevated hemoglobin levels (≥180 g/L) at subsequent donations. CONCLUSION: Hemoglobin concentrations were elevated in donors on TRT, and significant numbers had hemoglobin levels above those recommended by current guidelines. These data also suggest that repeat blood donation was insufficient to maintain a hematocrit below 54%. Our findings raise concerns about the persistent risk of vascular events in these donors, particularly when coupled with the misperception by patients and health care providers that donation has reduced or eliminated the risks of TRT-induced polycythemia.