Cutaneous metastases as the presenting feature of lung cancer.

Lung cancer is the second most common cancer diagnosed in men and women worldwide with the highest mortality. A rare site of metastases for lung cancer is the skin. Typically, the diagnosis is secure prior to developing cutaneous metastases. We present a case of a man in his mid-70s who presented to dermatology with cutaneous metastases. We outline the presentation, diagnostic workup and management of this case. We also review the literature of cutaneous metastases in lung cancer; highlighting the clinical need for a timely accurate diagnosis and the implication in terms of prognosis.

Food insecurity and its consequences in indigenous children and youth in Canada.

Food insecurity (FI) is at a crisis level in some Indigenous communities and impacts many of the half million First Nations Inuit and Métis (FNIM) children across Canada, particularly in isolated northern communities. This can lead to malnutrition and can have significant impacts on the physical, intellectual, emotional and social development of a child, often with lasting effects across the life course. This is a narrative review article with extensive search of the medical literature with input from the FNIM National organizations. The primary cause of FI is an imbalance between the high price of food relative to household income, where poverty is a driving factor. The cost and lack of availability to healthy foods has resulted in a transition to unhealthy market foods. Food security programs need to be prioritized, multi-faceted and multi-tiered within a framework of food sovereignty. Translational science, research, to practice is also important. The use of successful Indigenous based models of FI, towards food sovereignty using self-determination, Indigenous Knowledge, strength-based models, and ancestral sustainability are critical. Continued community-based evaluation of FI towards sustainable healthy food programs are important for communities to initiate track, evaluate, and grow robust community-based programs to counter-balance FI. Continued scientific research in the fields of FI, food sovereignty, and their relationship to co-occurring conditions related to healthy eating and beverage consumption are vastly important to the health of Indigenous Peoples. These are all part of many Indigenous connection to the earth, through food source, the maintenance of health through ancestral ways of living, set in the premise of looking forward multiple generations towards the continued resiliency through food, diet, relationship, and sovereignty. Food Security is a human right and needs to be urgently addressed for Indigenous children in Canada.

Preventing symptomatic vitamin D deficiency and rickets among Indigenous infants and children in Canada.

Vitamin D deficiency (VitDD) rickets and other manifestations of severe VitDD, such as cardiomyopathy and hypocalcemic seizures, continue to be diagnosed in Canada. Breastfed Indigenous infants, particularly those living in northern communities, are disproportionately impacted, although formula-fed infants are not exempt in cases where the mother's vitamin D status is critically low. This statement deals with the prevention of rickets and hypocalcemia due to VitDD for Indigenous children, and revises an earlier document from the Canadian Paediatric Society. An assessment of the risk for VitDD is recommended for each maternal-infant dyad because of the link between maternal and infant VitDD. Along with supports for enhanced adherence, additional VitD supplementation is recommended for prenatal women and infants deemed at high risk and, in certain situations, intermittent higher dose supplementation may be required. Food insecurity can also contribute to rickets, so advocacy is required to prevent VitDD rickets in Indigenous children.

Near-Fatal Self-Harm Among Canadian Adolescents.

OBJECTIVE: To evaluate the clinical features of Canadian adolescents admitted to the intensive care unit (ICU) for medically serious self-harm. METHODS: 2700 Canadian paediatricians were surveyed monthly over two years (January 2017 to December 2018) through the Canadian Paediatric Surveillance Program to ascertain data from eligible cases. RESULTS: Ninety-three cases (73 female; age 15.2 ± 1.5) met the case definition. Four provinces reported the majority of cases: Quebec (n = 27), Ontario (n = 26), Alberta (n = 21), and British Columbia (n = 8). There were 10 deaths, 9 by hanging. Overdose and hanging were the most frequently reported methods of self-harm (74.2% and 19.4%, respectively). Overdose was more common in females (80.8% females vs. 50% males; χ2 = 7.8 (1), p = .005), whereas hanging was more common in males (35% males vs. 15.1% females, χ2 = 3.9 (1), p = .04). More females than males had a past psychiatric diagnosis (79% vs. 58%; χ2 = 4.1 (1), p = .06), a previous suicide attempt (55.9% vs. 29.4%, χ2 = 3.8 (1), p = .05), and prior use of mental health service (69.7% vs. 27.8%, χ2 = 10.4 (1), p = .001). Family conflict was the most commonly identified precipitating factor (43%) of self-harm. CONCLUSIONS: Among Canadian adolescents admitted to the ICU with medically serious self-harm, females demonstrate a higher rate of suicide attempts and prior mental health care engagement, whereas males are more likely to die by suicide. These findings are consistent with data from other adolescent samples, as well as data from working-age and older adults. Therefore, a sex-specific approach to suicide prevention is warranted as part of a national suicide prevention strategy; family conflict may be a specific target for suicide prevention interventions among adolescents.

Early Childhood Caries in Indigenous Communities.

The oral health of Indigenous children of Canada (First Nations, Inuit, and Métis) and the United States (American Indian and Alaska native) is a major child health disparity when compared with the general population of both countries. Early childhood caries (ECC) occurs in Indigenous children at an earlier age, with a higher prevalence, and at much greater severity than in the general population. ECC results in adverse oral health, affecting childhood health and well-being, and may result in high rates of costly surgical treatment under general anesthesia. ECC is an infectious disease that is influenced by multiple factors, but the social determinants of health are particularly important. This policy statement includes recommendations for preventive and clinical oral health care for infants, toddlers, preschool-aged children, and pregnant women by primary health care providers. It also addresses community-based health-promotion initiatives and access to dental care for Indigenous children. This policy statement encourages oral health interventions at early ages in Indigenous children, including referral to dental care for the use of sealants, interim therapeutic restorations, and silver diamine fluoride. Further community-based research on the microbiology, epidemiology, prevention, and management of ECC in Indigenous communities is also needed to reduce the dismally high rate of caries in this population.

Perinatal and Early-Life Nutrition, Epigenetics, and Allergy.

Epidemiological studies have shown a dramatic increase in the incidence and the prevalence of allergic diseases over the last several decades. Environmental triggers including risk factors (e.g., pollution), the loss of rural living conditions (e.g., farming conditions), and nutritional status (e.g., maternal, breastfeeding) are considered major contributors to this increase. The influences of these environmental factors are thought to be mediated by epigenetic mechanisms which are heritable, reversible, and biologically relevant biochemical modifications of the chromatin carrying the genetic information without changing the nucleotide sequence of the genome. An important feature characterizing epigenetically-mediated processes is the existence of a time frame where the induced effects are the strongest and therefore most crucial. This period between conception, pregnancy, and the first years of life (e.g., first 1000 days) is considered the optimal time for environmental factors, such as nutrition, to exert their beneficial epigenetic effects. In the current review, we discussed the impact of the exposure to bacteria, viruses, parasites, fungal components, microbiome metabolites, and specific nutritional components (e.g., polyunsaturated fatty acids (PUFA), vitamins, plant- and animal-derived microRNAs, breast milk) on the epigenetic patterns related to allergic manifestations. We gave insight into the epigenetic signature of bioactive milk components and the effects of specific nutrition on neonatal T cell development. Several lines of evidence suggest that atypical metabolic reprogramming induced by extrinsic factors such as allergens, viruses, pollutants, diet, or microbiome might drive cellular metabolic dysfunctions and defective immune responses in allergic disease. Therefore, we described the current knowledge on the relationship between immunometabolism and allergy mediated by epigenetic mechanisms. The knowledge as presented will give insight into epigenetic changes and the potential of maternal and post-natal nutrition on the development of allergic disease.

The prevalence of high school multi-sport participation in elite national football league athletes.

Objectives: Early youth specialization is increasingly being researched and identified as a risk factor for overuse injuries and burnout. This study aimed to characterize high school sport specialization in top National Football League (NFL) athletes and determine whether associations exist between single-sport specialization and future injury risk, performance, and longevity.Methods: For NFL first-round draft picks from 2008-2017, data on the number of games played in the NFL, overuse injuries causing athletes to miss one or more regular season games, Pro Bowl selections, and current status in the NFL were collected using publicly available information.Results: A total of 318 athletes were analyzed. Multi-sport athletes were highly prevalent (88%, n = 280), while only 12% (n = 38) of athletes were classified as single-sport. No difference between multi-sport and single-sport athletes was found regarding games missed to upper (p = 0.93) or lower extremity injuries (p = 0.49), total games played (p = 0.57), or NFL longevity (p = 0.97). There was no significant difference in the proportions of athletes reaching at least 1 Pro Bowl.Conclusion: The majority of NFL first-round draft picks were multi-sport athletes in high school. Single-sport football participation in high school does not appear to aid athletes in reaching or succeeding in the NFL.

Proof-of-PUF Enabled Blockchain: Concurrent Data and Device Security for Internet-of-Energy.

A detailed review on the technological aspects of Blockchain and Physical Unclonable Functions (PUFs) is presented in this article. It stipulates an emerging concept of Blockchain that integrates hardware security primitives via PUFs to solve bandwidth, integration, scalability, latency, and energy requirements for the Internet-of-Energy (IoE) systems. This hybrid approach, hereinafter termed as PUFChain, provides device and data provenance which records data origins, history of data generation and processing, and clone-proof device identification and authentication, thus possible to track the sources and reasons of any cyber attack. In addition to this, we review the key areas of design, development, and implementation, which will give us the insight on seamless integration with legacy IoE systems, reliability, cyber resilience, and future research challenges.

Explaining the variability in cardiovascular risk factors among First Nations communities in Canada: a population-based study.

BACKGROUND: Historical, colonial, and racist policies continue to influence the health of Indigenous people, and they continue to have higher rates of chronic diseases and reduced life expectancy compared with non-Indigenous people. We determined factors accounting for variations in cardiovascular risk factors among First Nations communities in Canada. METHODS: Men and women (n=1302) aged 18 years or older from eight First Nations communities participated in a population-based study. Questionnaires, physical measures, blood samples, MRI of preclinical vascular disease, and community audits were collected. In this cross-sectional analysis, the main outcome was the INTERHEART risk score, a measure of cardiovascular risk factor burden. A multivariable model was developed to explain the variations in INTERHEART risk score among communities. The secondary outcome was MRI-detected carotid wall volume, a measure of subclinical atherosclerosis. FINDINGS: The mean INTERHEART risk score of all communities was 17·2 (SE 0·2), and more than 85% of individuals had a risk score in the moderate to high risk range. Subclinical atherosclerosis increased significantly across risk score categories (p<0·0001). Socioeconomic advantage (-1·4 score, 95% CI -2·5 to -0·3; p=0·01), trust between neighbours (-0·7, -1·2 to -0·3; p=0·003), higher education level (-1·9, -2·9 to -0·8, p<0·001), and higher social support (-1·1, -2·0 to -0·2; p=0·02) were independently associated with a lower INTERHEART risk score; difficulty accessing routine health care (2·2, 0·3 to 4·1, p=0·02), taking prescription medication (3·5, 2·8 to 4·3; p<0·001), and inability to afford prescription medications (1·5, 0·5 to 2·6; p=0·003) were associated with a higher INTERHEART risk score. Collectively, these factors explained 28% variation in the cardiac risk score among communities. Communities with higher socioeconomic advantage and greater trust, and individuals with higher education and social support, had a lower INTERHEART risk score. Communities with difficulty accessing health care, and individuals taking or unable to afford prescription medications, had a higher INTERHEART risk score. INTERPRETATION: Cardiac risk factors are lower in communities with high socioeconomic advantage, greater trust, social support and educational opportunities, and higher where it is difficult to access health care or afford prescription medications. Strategies to optimise the protective factors and reduce barriers to health care in First Nations communities might contribute to improved health and wellbeing. FUNDING: Heart and Stroke Foundation of Canada, Canadian Partnership Against Cancer, Canadian Institutes for Health Research.

Early Sports Specialization Is Associated With Upper Extremity Injuries in Throwers and Fewer Games Played in Major League Baseball.

BACKGROUND: Single-sport athletes who specialize in baseball at a young age may have a greater predisposition to overuse injury, burnout, and decreased career longevity when compared with multiple-sport athletes. The effect of sport specialization has not been studied in professional baseball players. HYPOTHESIS: Major League Baseball (MLB) players who played multiple sports in high school would experience fewer injuries, spend less time on the disabled list, play more games, and have a longer career than athletes who played only baseball in high school. STUDY DESIGN: Descriptive epidemiology study. METHODS: First- and second-round MLB draft picks from 2008 to 2016 who played in at least 1 professional game were included in this study. Athletes who participated in 1 or more sports in addition to baseball during high school were considered multisport athletes, and athletes who participated in only baseball were considered single-sport athletes. For each athlete, participation in high school sports, injuries sustained in MLB and Minor League Baseball, number of days on the disabled list for each injury, number of games played in both leagues, and whether the athlete was still active were collected from publicly available records. RESULTS: A total of 746 athletes were included in this study: 240 (32%) multisport and 506 (68%) single sport. Multisport athletes played in significantly more mean total games (362.8 vs 300.8; P < .01) as well as more mean MLB games (95.9 vs 71.6; P = .04) than single-sport athletes. There was no difference in the mean number of seasons played in the major leagues (1.8 vs 1.6; P = .15) or minor league (5.25 vs 5.20; P = .23) between multisport and single-sport athletes. Single-sport athletes had a significantly higher prevalence of upper extremity injuries compared with multisport athletes (136 [63%] vs 55 [50%]; P = .009). Single-sport pitchers also had a higher prevalence of shoulder and elbow injuries (86 vs 27; P = .008) and were more likely to have recurrent elbow injuries (33% vs 17% recurrence; P = .002) compared with multisport pitchers. CONCLUSION: Professional baseball players who participated in multiple sports in high school played in more major league games and experienced lower rates of upper and lower extremity injuries than players who played only baseball in high school.

Short-term outcomes associated with drain use in shoulder arthroplasties: a prospective, randomized controlled trial.

BACKGROUND: This study examined the immediate outcomes during the perioperative period associated with drains in the setting of total shoulder arthroplasty or reverse shoulder arthroplasty. We hypothesized that drain use would result in lower postoperative hemoglobin and hematocrit levels that would increase transfusion rates and longer hospital stays that would increase hospital costs. METHODS: The study prospectively randomized 100 patients (55% women; average age, 69.3 years) who underwent total shoulder arthroplasty or reverse shoulder arthroplasty to receive a closed-suction drainage device (drain group, n = 50) or not (control group, n = 50) at the time of wound closure. Basic demographic information and intraoperative and postoperative data were collected. RESULTS: The groups were similar with respect to basic patient demographics. Postoperatively, drains had no effect on transfusion rates or any perioperative complication (P > .715). There were also no significant differences in hemoglobin or hematocrit levels immediately after surgery or on postoperative day 1. On average, patients were discharged from the hospital 1.6 days and 2.1 days postoperatively in the control and drain groups, respectively (P = .124). The average cost associated for the control cohort's hospital stay was $35,796 ± $13,078 compared with $43,219 ± $24,679 for the drain cohort (P = .063). DISCUSSION: Drain use after shoulder arthroplasty had no appreciable difference on short-term perioperative outcomes, postoperative anemia, length of hospital stay, or cost. It is possible that the potential negative effects of postoperative drainage are blunted by the routine use of tranexamic acid.

Lower Extremity Injuries in Ice Hockey: Current Concepts.

Ice hockey is a fast-paced, collision sport requiring tremendous skill and finesse, yet ice hockey can be a harsh and violent game. It has one of the highest musculoskeletal injury rates in all of competitive sports. Razor sharp skates, aluminum sticks and boards made from high density polyethylene (HDPE), all contribute to the intrinsic hazards of the game. The objective of this article is to review evaluation, management, and return-to-the-rink guidelines after common lower extremity ice hockey injuries.

Canadian Alliance for Healthy Hearts and Minds: First Nations Cohort Study Rationale and Design.

BACKGROUND: This is the first national indigenous cohort study in which a common, in-depth protocol with a common set of objectives has been adopted by several indigenous communities across Canada. OBJECTIVES: The overarching objective of the Canadian Alliance for Healthy Hearts and Minds (CAHHM) cohort is to investigate how the community-level environment is associated with individual health behaviors and the presence and progression of chronic disease risk factors and chronic diseases such as cardiovascular disease (CVD) and cancer. METHODS: CAHHM aims to recruit approximately 2,000 First Nations indigenous individuals from up to nine communities across Canada and have participants complete questionnaires, blood collection, physical measurements, cognitive assessments, and magnetic resonance imaging (MRI). RESULTS: Through individual- and community-level data collection, we will develop an understanding of the specific role of the socioenvironmental, biological, and contextual factors have on the development of chronic disease risk factors and chronic diseases. CONCLUSIONS: Information collected in the indigenous cohort will be used to assist communities to develop local management strategies for chronic disease, and can be used collectively to understand the contextual, environmental, socioeconomic, and biological determinants of differences in health status in harmony with First Nations beliefs and reality.

Integrated genome and transcriptome sequencing identifies a noncoding mutation in the genome replication factor DONSON as the cause of microcephaly-micromelia syndrome.

While next-generation sequencing has accelerated the discovery of human disease genes, progress has been largely limited to the "low hanging fruit" of mutations with obvious exonic coding or canonical splice site impact. In contrast, the lack of high-throughput, unbiased approaches for functional assessment of most noncoding variants has bottlenecked gene discovery. We report the integration of transcriptome sequencing (RNA-seq), which surveys all mRNAs to reveal functional impacts of variants at the transcription level, into the gene discovery framework for a unique human disease, microcephaly-micromelia syndrome (MMS). MMS is an autosomal recessive condition described thus far in only a single First Nations population and causes intrauterine growth restriction, severe microcephaly, craniofacial anomalies, skeletal dysplasia, and neonatal lethality. Linkage analysis of affected families, including a very large pedigree, identified a single locus on Chromosome 21 linked to the disease (LOD > 9). Comprehensive genome sequencing did not reveal any pathogenic coding or canonical splicing mutations within the linkage region but identified several nonconserved noncoding variants. RNA-seq analysis detected aberrant splicing in DONSON due to one of these noncoding variants, showing a causative role for DONSON disruption in MMS. We show that DONSON is expressed in progenitor cells of embryonic human brain and other proliferating tissues, is co-expressed with components of the DNA replication machinery, and that Donson is essential for early embryonic development in mice as well, suggesting an essential conserved role for DONSON in the cell cycle. Our results demonstrate the utility of integrating transcriptomics into the study of human genetic disease when DNA sequencing alone is not sufficient to reveal the underlying pathogenic mutation.

The role of PKCζ in cord blood T-cell maturation towards Th1 cytokine profile and its epigenetic regulation by fish oil.

While immunodeficiency of immaturity of the neonate has been considered important as the basis for unusual susceptibility to infection, it has also been recognized that the ability to progress from an immature Th2 cytokine predominance to a Th1 profile has relevance in determining whether children will develop allergy, providing an opportunity for epigenetic regulation through environmental pressures. However, this notion remains relatively unexplored. Here, we present evidence that there are two major control points to explain the immunodeficiency in cord blood (CB) T-cells, a deficiency in interleukin (IL)-12 (IL-12) producing and IL-10 overproducing accessory cells, leading to a decreased interferon γ (IFNγ) synthesis and the other, an intrinsic defect in T-cell protein kinase C (PKC) ζ (PKCζ) expression. An important finding was that human CB T-cells rendered deficient in PKCζ, by shRNA knockdown, develop into low tumour necrosis factor α (TNFα) and IFNγ but increased IL-13 producing cells. Interestingly, we found that the increase in PKCζ levels in CB T-cells caused by prenatal supplementation with fish oil correlated with modifications of histone acetylation at the PKCζ gene (PRKCZ) promoter. The data demonstrate that PKCζ expression regulates the maturation of neonatal T-cells into specific functional phenotypes and that environmental influences may work via PKCζ to regulate these phenotypes and disease susceptibility.

Is There a Difference in Graft Motion for Bone-Tendon-Bone and Hamstring Autograft ACL Reconstruction at 6 Weeks and 1 Year?

BACKGROUND: Bone-patellar tendon-bone (BTB) grafts are generally believed to heal more quickly than soft tissue grafts after anterior cruciate ligament (ACL) reconstruction, but little is known about the time course of healing or motion of the grafts within the bone tunnels. HYPOTHESIS: Graft-tunnel motion will be greater in hamstring (HS) grafts compared with BTB grafts and will be less at 1 year than at 6 weeks. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve patients underwent anatomic single-bundle ACL reconstruction using HS or BTB autografts (6 per group) with six 0.8-mm tantalum beads embedded in each graft. Dynamic stereo x-ray images were collected at 6 weeks and 1 year during treadmill walking and stair descent and at 1 year during treadmill running. Tibiofemoral kinematics and bead positions were evaluated. Graft-tunnel motion was based on bead range of motion during the loading response phase (first 10%) of the gait cycle. RESULTS: During treadmill walking, there was no difference in femoral tunnel or tibial tunnel motion between BTB or HS grafts at 6 weeks (BTB vs HS: 2.00 ± 1.05 vs 1.25 ± 0.67 mm [femoral tunnel]; 1.20 ± 0.63 vs 1.27 ± 0.71 mm [tibial tunnel]), or 1 year (BTB vs HS: 1.62 ± 0.76 vs 1.08 ± 0.26 mm [femoral tunnel]; 1.58 ± 0.75 vs 1.68 ± 0.53 mm [tibial tunnel]). During stair descent, there was no difference in femoral or tibial tunnel motion between BTB and HS grafts at 6 weeks or 1 year. With running, there was no difference between graft types at 1 year. For all results, P values were > .05. Knee kinematics were consistent with the literature. CONCLUSION: During walking and stair descent, ACL reconstruction using suspensory fixation yielded no difference between graft types in femoral or tibial tunnel motion at 6 weeks or 1 year. All subjects were asymptomatic with knee kinematics similar to that of the literature. The significance of persistent, small (1 to 3 mm) movements at 1 year for healing or graft performance is unknown. CLINICAL RELEVANCE: These study results may have significant implications for graft choice, rehabilitation strategies, and timing for return to sports.

The Effects of Anterior Cruciate Ligament Deficiency on the Meniscus and Articular Cartilage: A Novel Dynamic In Vitro Pilot Study.

BACKGROUND: Anterior cruciate ligament (ACL) injury increases the risk of meniscus and articular cartilage damage, but the causes are not well understood. Previous in vitro studies were static, required extensive knee dissection, and likely altered meniscal and cartilage contact due to the insertion of pressure sensing devices. HYPOTHESIS: ACL deficiency will lead to increased translation of the lateral meniscus and increased deformation of the medial meniscus as well as alter cartilage contact location, strain, and area. STUDY DESIGN: Descriptive laboratory study. METHODS: With minimally invasive techniques, six 1.0-mm tantalum beads were implanted into the medial and lateral menisci of 6 fresh-frozen cadaveric knees. Dynamic stereo x-rays (DSXs) were obtained during dynamic knee flexion (from 15° to 60°, simulating a standing squat) with a 46-kg load in intact and ACL-deficient states. Knee kinematics, meniscal movement and deformation, and cartilage contact were compared by novel imaging coregistration. RESULTS: During dynamic knee flexion from 15° to 60°, the tibia translated 2.6 mm (P = .05) more anteriorly, with 2.3° more internal rotation (P = .04) with ACL deficiency. The medial and lateral menisci, respectively, translated posteriorly an additional 0.7 mm (P = .05) and 1.0 mm (P = .03). Medial and lateral compartment cartilage contact location moved posteriorly (2.0 mm [P = .05] and 2.0 mm [P = .04], respectively). CONCLUSION: The lateral meniscus showed greater translation with ACL deficiency compared with the medial meniscus, which may explain the greater incidences of acute lateral meniscus tears and chronic medial meniscus tears. Furthermore, cartilage contact location moved further posteriorly than that of the meniscus in both compartments, possibly imparting more meniscal stresses that may lead to early degeneration. This new, minimally invasive, dynamic in vitro model allows the study of meniscus function and cartilage contact and can be applied to evaluate different pathologies and surgical techniques. CLINICAL RELEVANCE: This novel model illustrates that ACL injury may lead to significant meniscus and cartilage abnormalities acutely, and these parameters are dynamically measurable while maintaining native anatomy.

Can reduced predation offset negative effects of sea louse parasites on chum salmon?

The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host-parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations.