Prenatal exposure to metal mixtures and childhood temporal processing in the PROGRESS Birth Cohort Study: Modification by childhood obesity

Children are frequently exposed to various biological trace metals, some essential for their development, while others can be potent neurotoxicants. Furthermore, the inflammatory and metabolic conditions associated with obesity may interact with and amplify the impact of metal exposure on neurodevelopment. However, few studies have assessed the potential modification effect of body mass index (BMI). As a result, we investigated the role of child BMI phenotype on the relationship between prenatal exposure to metal mixtures and temporal processing. Leveraging the PROGRESS birth cohort in Mexico City, children (N = 563) aged 6-9 years completed a Temporal Response Differentiation (TRD) task where they had to hold a lever down for 10-14 s. Blood and urinary metal (As, Pb, Cd, and Mn) measurements were collected from mothers in the 2nd and 3rd trimesters. Child BMI z-scores were dichotomized to normal (between -2 and +0.99) and high (≥1.00). Covariate-adjusted weighted quantile sum (WQS) regression models were used to estimate and examine the combined effect of metal biomarkers (i.e., blood and urine) on TRD measures. Effect modification by the child's BMI was evaluated using 2-way interaction terms. Children with a high BMI and greater exposure to the metal mixture during prenatal development exhibited significant temporal processing deficits compared to children with a normal BMI. Notably, children with increased exposure to the metal mixture and higher BMI had a decrease in the percent of tasks completed (β = -10.13; 95 % CI: -19.84, -0.42), number of average holds (β = -2.15; 95 % CI: -3.88, -0.41), longer latency (β = 0.78; 95 % CI: 0.13, 1.44), and greater variability in the standard deviation of the total hold time (β = 2.08; 95 % CI: 0.34, 3.82) compared to normal BMI children. These findings implicate that high BMI may amplify the effect of metals on children's temporal processing. Understanding the relationship between metal exposures, temporal processing, and childhood obesity can provide valuable insights for developing targeted environmental interventions.

Prenatal metal exposures and childhood gut microbial signatures are associated with depression score in late childhood

BACKGROUND

Childhood depression is a major public health issue worldwide. Previous studies have linked both prenatal metal exposures and the gut microbiome to depression in children. However, few, if any, have studied their interacting effect in specific subgroups of children.

OBJECTIVES

Using an interpretable machine-learning method, this study investigates whether children with specific combinations of prenatal metals and childhood microbial signatures (cliques or groups of metals and microbes) were more likely to have higher depression scores at 9-11 years of age.

METHODS

We leveraged data from a well-characterized pediatric longitudinal birth cohort in Mexico City and its microbiome substudy (n = 112). Eleven metal exposures were measured in maternal whole blood samples in the second and third trimesters of pregnancy. The gut microbial abundances were measured at 9-11-year-olds using shotgun metagenomic sequencing. Depression symptoms were assessed using the Child Depression Index (CDI) t-scores at 9-11 years of age. We used Microbial and Chemical Exposure Analysis (MiCxA), which combines interpretable machine-learning into a regression framework to identify and estimate joint associations of metal-microbial cliques in specific subgroups. Analyses were adjusted for relevant covariates.

RESULTS

We identified a subgroup of children (11.6 % of the sample) characterized by a four-component metal-microbial clique that had a significantly high depression score (15.4 % higher than the rest) in late childhood. This metal-microbial clique consisted of high Zinc in the second trimester, low Cobalt in the third trimester, a high abundance of Bacteroides fragilis, a high abundance of Faecalibacterium prausnitzii. All combinations of cliques (two-, three-, and four-components) were significantly associated with increased log-transformed t-scored CDI (β = 0.14, 95%CI = [0.05,0.23], P < 0.01 for the four-component clique).

SIGNIFICANCE

This study offers a new approach to chemical-microbial analysis and a novel demonstration that children with specific gut microbiome cliques and metal exposures during pregnancy may have a higher likelihood of elevated depression scores.

Sensitive development windows of prenatal air pollution and cognitive functioning in preschool age Mexican children

Introduction

Neurotoxicity resulting from air pollution is of increasing concern. Considering exposure timing effects on neurodevelopmental impairments may be as important as the exposure dose. We used distributed lag regression to determine the sensitive windows of prenatal exposure to fine particulate matter (PM2.5) on children's cognition in a birth cohort in Mexico.

Methods

Analysis included 553 full-term (≥37 weeks gestation) children. Prenatal daily PM2.5 exposure was estimated using a validated satellite-based spatiotemporal model. McCarthy Scales of Children's Abilities (MSCA) were used to assess children's cognitive function at 4-5 years old (lower scores indicate poorer performance). To identify susceptibility windows, we used Bayesian distributed lag interaction models to examine associations between prenatal PM2.5 levels and MSCA. This allowed us to estimate vulnerable windows while testing for effect modification.

Results

After adjusting for maternal age, socioeconomic status, child age, and sex, Bayesian distributed lag interaction models showed significant associations between increased PM2.5 levels and decreased general cognitive index scores at 31-35 gestation weeks, decreased quantitative scale scores at 30-36 weeks, decreased motor scale scores at 30-36 weeks, and decreased verbal scale scores at 37-38 weeks. Estimated cumulative effects (CE) of PM2.5 across pregnancy showed significant associations with general cognitive index (C E ^ = -0.35, 95% confidence interval [CI] = -0.68, -0.01), quantitative scale (C E ^ = -0.27, 95% CI = -0.74, -0.02), motor scale (C E ^ = -0.25, 95% CI = -0.44, -0.05), and verbal scale (C E ^ = -0.2, 95% CI = -0.43, -0.02). No significant sex interactions were observed.

Conclusions

Prenatal exposure to PM2.5, particularly late pregnancy, was inversely associated with subscales of MSCA. Using data-driven methods to identify sensitive window may provide insight into the mechanisms of neurodevelopmental impairment due to pollution.

Investigating Racial Disparities in Cancer Crowdfunding: A Comprehensive Study of Medical GoFundMe Campaigns

BACKGROUND

In recent years, there has been growing concern about prejudice in crowdfunding; however, empirical research remains limited, particularly in the context of medical crowdfunding. This study addresses the pressing issue of racial disparities in medical crowdfunding, with a specific focus on cancer crowdfunding on the GoFundMe platform.

OBJECTIVE

This study aims to investigate racial disparities in cancer crowdfunding using average donation amount, number of donations, and success of the fundraising campaign as outcomes.

METHODS

Drawing from a substantial data set of 104,809 campaigns in the United States, we used DeepFace facial recognition technology to determine racial identities and used regression models to examine racial factors in crowdfunding performance. We also examined the moderating effect of the proportion of White residents on crowdfunding bias and used 2-tailed t tests to measure the influence of racial anonymity on crowdfunding success. Owing to the large sample size, we set the cutoff for significance at P<.001.

RESULTS

In the regression and supplementary analyses, the racial identity of the fundraiser significantly predicted average donations (P<.001), indicating that implicit bias may play a role in donor behavior. Gender (P=.04) and campaign description length (P=.62) did not significantly predict the average donation amounts. The race of the fundraiser was not significantly associated with the number of donations (P=.42). The success rate of cancer crowdfunding campaigns, although generally low (11.77%), showed a significant association with the race of the fundraiser (P<.001). After controlling for the covariates of the fundraiser gender, fundraiser age, local White proportion, length of campaign description, and fundraising goal, the average donation amount to White individuals was 17.68% higher than for Black individuals. Moreover, campaigns that did not disclose racial information demonstrated a marginally higher average donation amount (3.92%) than those identified as persons of color. Furthermore, the racial composition of the fundraiser's county of residence was found to exert influence (P<.001); counties with a higher proportion of White residents exhibited reduced racial disparities in crowdfunding outcomes.

CONCLUSIONS

This study contributes to a deeper understanding of racial disparities in cancer crowdfunding. It highlights the impact of racial identity, geographic context, and the potential for implicit bias in donor behavior. As web-based platforms evolve, addressing racial inequality and promoting fairness in health care financing remain critical goals. Insights from this research suggest strategies such as maintaining racial anonymity and ensuring that campaigns provide strong evidence of deservingness. Moreover, broader societal changes are necessary to eliminate the financial distress that drives individuals to seek crowdfunding support.

Prenatal Lead Exposure Is Associated with Reduced Abundance of Beneficial Gut Microbial Cliques in Late Childhood: An Investigation Using Microbial Co-Occurrence Analysis (MiCA)

Many analytical methods used in gut microbiome research focus on either single bacterial taxa or the whole microbiome, ignoring multibacteria relationships (microbial cliques). We present a novel analytical approach to identify microbial cliques within the gut microbiome of children at 9-11 years associated with prenatal lead (Pb) exposure. Data came from a subset of participants (n = 123) in the Programming Research in Obesity, Growth, Environment and Social Stressors cohort. Pb concentrations were measured in maternal whole blood from the second and third trimesters of pregnancy. Stool samples collected at 9-11 years old underwent metagenomic sequencing to assess the gut microbiome. Using a novel analytical approach, Microbial Co-occurrence Analysis (MiCA), we paired a machine learning algorithm with randomization-based inference to first identify microbial cliques that were predictive of prenatal Pb exposure and then estimate the association between prenatal Pb exposure and microbial clique abundance. With second-trimester Pb exposure, we identified a two-taxa microbial clique that included Bifidobacterium adolescentis and Ruminococcus callidus and a three-taxa clique that also included Prevotella clara. Increasing second-trimester Pb exposure was associated with significantly increased odds of having the two-taxa microbial clique below the median relative abundance (odds ratio (OR) = 1.03, 95% confidence interval (CI) [1.01-1.05]). Using a novel combination of machine learning and causal inference, MiCA identified a significant association between second-trimester Pb exposure and the reduced abundance of a probiotic microbial clique within the gut microbiome in late childhood.

Prenatal manganese biomarkers and operant test battery performance in Mexican children: Effect modification by child sex

BACKGROUND

Manganese (Mn) is essential to healthy neurodevelopment, but both Mn deficiency and over-exposure have been linked to prefrontal cortex (PFC) impairments, the brain region that regulates cognitive and neurobehavioral processes responsible for spatial memory, learning, motivation, and time perception. These processes facilitated by attention, inhibitory control, working memory, and cognitive flexibility are often sexually dimorphic and complex, driven by multiple interconnected neurologic and cognitive domains.

OBJECTIVE

We investigated the role of child sex as an effect modifier of the association between prenatal Mn exposure and performance in an operant testing battery (OTB) that assessed multiple cognitive and behavioral functional domains.

METHODS

Children (N = 575) aged 6-8 years completed five OTB tasks. Blood and urinary Mn measurements were collected from mothers in the 2nd and 3rd trimesters. Multiple regression models estimated the association between Mn biomarkers at each trimester with OTB performance while adjusting for socio-demographic covariates. Covariate-adjusted weighted quantile sum (WQS) regression models were used to estimate the association of a Mn multi-media biomarker (MMB) mixture with OTB performance. Interaction terms were used to estimate modification effect by child sex.

RESULTS

Higher blood Mn exposure was associated with better response rates (more motivation) on the progressive ratio task and higher overall accuracy on the delayed matching-to-sample task. In the WQS models, the MMB mixture was associated with better response rates (more motivation) on the progressive ratio task. Additionally, for the linear and WQS models, we observed a modification effect by child sex in the progressive ratio and delayed matching-to-sample tasks. Higher prenatal Mn biomarker levels were associated with improved task performance for girls and reduced performance in boys.

CONCLUSION

Higher prenatal blood Mn concentrations and the MMB mixture predicted improved performance on two of five operant tasks. Higher prenatal Mn concentrations regulated executive functions in children in a sexually dimorphic manner. Higher prenatal Mn exposure is associated with improved performance on spatial memory and motivation tasks in girls, suggesting that Mn's nutritional role is sexually dimorphic, and should be considered when making dietary and/or environmental intervention recommendations.

The interconnection between obesity and executive function in adolescence: The role of the gut microbiome

In the United States, adolescent obesity is a growing epidemic associated with maladaptive executive functioning. Likewise, data link the microbiome to obesity. Emerging microbiome research has demonstrated an interconnection between the gut microbiome and the brain, indicating a bidirectional communication system within the gut-microbiome-brain axis in the pathophysiology of obesity. This narrative review identifies and summarizes relevant research connecting adolescent obesity as it relates to three core domains of executive functioning and the contribution of the gut microbiome in the relationship between obesity and executive functions in adolescence. The review suggests that (1) the interconnection between obesity, executive function, and the gut microbiome is a bidirectional connection, and (2) the gut microbiome may mediate the neurobiological pathways between obesity and executive function deficits. The findings of this review provide valuable insights into obesity-associated executive function deficits and elucidate the possible mediation role of the gut microbiome.

Sex-specific association between prenatal manganese exposure and working memory in school-aged children in Mexico city: An exploratory multi-media approach

It remains unclear whether manganese (Mn) exposure affects working memory (WM) in a sexually dimorphic manner. Further, no gold standard media exists to measure Mn, suggesting a combined blood and urinary Mn index may better capture the totality of exposure. We investigated the modification effect of child sex on the influence of prenatal Mn exposure on WM in school-age children, exploring two methodological frameworks to integrate exposure estimates across multiple exposure biomarkers. Leveraging the PROGRESS birth cohort in Mexico City, children (N = 559) ages 6-8 completed the between errors and strategy measures of the CANTAB Spatial Working Memory (SWM) task. Mn levels were assayed in blood and urine of mothers during the 2nd and 3rd trimesters and in umbilical cord blood from mothers and children at delivery. Weighted quantile sum regression estimated the association of a multi-media biomarker (MMB) mixture with SWM. We applied a confirmatory factor analysis to similarly quantify a latent blood Mn burden index. We then used an adjusted linear regression to estimate the Mn burden index with SWM measures. Interaction terms were used to estimate the modification effect by child sex for all models. Results showed that the between-errors-specific MMB mixture (i.e., this model demonstrates the impact of the MMB mixture on the between-error scores.) was associated (β = 6.50, 95% CI: 0.91, 12.08) with fewer between errors for boys and more between errors for girls. The strategy-specific MMB mixture (i.e., this model demonstrates the impact of the MMB mixture on the strategy scores) was associated (β = -1.36, 95% CI: 2.55, - 0.18) with less efficient strategy performance for boys and more efficient strategy performance for girls. A higher Mn burden index was associated (β = 0.86, 95% CI: 0.00, 1.72) with more between errors in the overall sample. The vulnerability to prenatal Mn biomarkers on SWM differs in the directionality by child sex. An MMB mixture and composite index of body burden are stronger predictors than a single biomarker for Mn exposure on WM performance.

Multi-ancestry genome-wide analysis identifies shared genetic effects and common genetic variants for self-reported sleep duration

Both short (≤6 h per night) and long sleep duration (≥9 h per night) are associated with increased risk of chronic diseases. Despite evidence linking habitual sleep duration and risk of disease, the genetic determinants of sleep duration in the general population are poorly understood, especially outside of European (EUR) populations. Here, we report that a polygenic score of 78 European ancestry sleep duration single-nucleotide polymorphisms (SNPs) is associated with sleep duration in an African (n = 7288; P = 0.003), an East Asian (n = 13 618; P = 6 × 10-4) and a South Asian (n = 7485; P = 0.025) genetic ancestry cohort, but not in a Hispanic/Latino cohort (n = 8726; P = 0.71). Furthermore, in a pan-ancestry (N = 483 235) meta-analysis of genome-wide association studies (GWAS) for habitual sleep duration, 73 loci are associated with genome-wide statistical significance. Follow-up of five loci (near HACD2, COG5, PRR12, SH3RF1 and KCNQ5) identified expression-quantitative trait loci for PRR12 and COG5 in brain tissues and pleiotropic associations with cardiovascular and neuropsychiatric traits. Overall, our results suggest that the genetic basis of sleep duration is at least partially shared across diverse ancestry groups.

Racial differences in the effect of verbal and nonverbal memory on concrete planning for future care needs among older adults: a multi-group structural equation modeling approach

Concrete planning for future care needs may positively impact older adults' subsequent mental health and quality of life. However, the cognitive factors that facilitate concrete planning among Black and White older adults are still poorly understood. We investigated whether there are significant differences between Black (n = 159) and White (n = 262) older adults in concrete planning and explored racial differences in the relationship between verbal and nonverbal episodic memory and concrete planning. Results revealed that Blacks showed lower engagement in concrete planning and lower scores than Whites on each verbal and nonverbal memory task. For Blacks, but not Whites, verbal memory and nonverbal memory performance predicted concrete planning with higher nonverbal memory relating to less concrete planning and higher verbal memory associated with more concrete planning. Our findings suggest racial differences exist in how episodic verbal and nonverbal memory affect concrete planning, a crucial factor for older adults' preparation for future care.

Linguistic Methodologies to Surveil the Leading Causes of Mortality: Scoping Review of Twitter for Public Health Data

BACKGROUND

Twitter has become a dominant source of public health data and a widely used method to investigate and understand public health-related issues internationally. By leveraging big data methodologies to mine Twitter for health-related data at the individual and community levels, scientists can use the data as a rapid and less expensive source for both epidemiological surveillance and studies on human behavior. However, limited reviews have focused on novel applications of language analyses that examine human health and behavior and the surveillance of several emerging diseases, chronic conditions, and risky behaviors.

OBJECTIVE

The primary focus of this scoping review was to provide a comprehensive overview of relevant studies that have used Twitter as a data source in public health research to analyze users' tweets to identify and understand physical and mental health conditions and remotely monitor the leading causes of mortality related to emerging disease epidemics, chronic diseases, and risk behaviors.

METHODS

A literature search strategy following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) extended guidelines for scoping reviews was used to search specific keywords on Twitter and public health on 5 databases: Web of Science, PubMed, CINAHL, PsycINFO, and Google Scholar. We reviewed the literature comprising peer-reviewed empirical research articles that included original research published in English-language journals between 2008 and 2021. Key information on Twitter data being leveraged for analyzing user language to study physical and mental health and public health surveillance was extracted.

RESULTS

A total of 38 articles that focused primarily on Twitter as a data source met the inclusion criteria for review. In total, two themes emerged from the literature: (1) language analysis to identify health threats and physical and mental health understandings about people and societies and (2) public health surveillance related to leading causes of mortality, primarily representing 3 categories (ie, respiratory infections, cardiovascular disease, and COVID-19). The findings suggest that Twitter language data can be mined to detect mental health conditions, disease surveillance, and death rates; identify heart-related content; show how health-related information is shared and discussed; and provide access to users' opinions and feelings.

CONCLUSIONS

Twitter analysis shows promise in the field of public health communication and surveillance. It may be essential to use Twitter to supplement more conventional public health surveillance approaches. Twitter can potentially fortify researchers' ability to collect data in a timely way and improve the early identification of potential health threats. Twitter can also help identify subtle signals in language for understanding physical and mental health conditions.

Prenatal Pb exposure is associated with reduced abundance of beneficial gut microbial cliques in late childhood: an investigation using Microbial Co-occurrence Analysis (MiCA)

Background

Many analytical methods used in gut microbiome research focus on either single bacterial taxa or the whole microbiome, ignoring multi-bacteria relationships (microbial cliques). We present a novel analytical approach to identify multiple bacterial taxa within the gut microbiome of children at 9-11 years associated with prenatal Pb exposure.

Methods

Data came from a subset of participants (n=123) in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort. Pb concentrations were measured in maternal whole blood from the second and third trimesters of pregnancy. Stool samples collected at 9-11 years old underwent metagenomic sequencing to assess the gut microbiome. Using a novel analytical approach, Microbial Co-occurrence Analysis (MiCA), we paired a machine-learning algorithm with randomization-based inference to first identify microbial cliques that were predictive of prenatal Pb exposure and then estimate the association between prenatal Pb exposure and microbial clique abundance.

Results

With second-trimester Pb exposure, we identified a 2-taxa microbial clique that included Bifidobacterium adolescentis and Ruminococcus callidus, and a 3-taxa clique that added Prevotella clara. Increasing second-trimester Pb exposure was associated with significantly increased odds of having the 2-taxa microbial clique below the 50th percentile relative abundance (OR=1.03,95%CI[1.01-1.05]). In an analysis of Pb concentration at or above vs. below the United States and Mexico guidelines for child Pb exposure, odds of the 2-taxa clique in low abundance were 3.36(95%CI[1.32-8.51]) and 6.11(95%CI[1.87-19.93]), respectively. Trends were similar with the 3-taxa clique but not statistically significant.

Discussion

Using a novel combination of machine-learning and causal-inference, MiCA identified a significant association between second-trimester Pb exposure and reduced abundance of a probiotic microbial clique within the gut microbiome in late childhood. Pb exposure levels at the guidelines for child Pb poisoning in the United States, and Mexico are not sufficient to protect against the potential loss of probiotic benefits.

A60 DOWN WITH THE SHP-1: CHRONIC HELMINTH INFECTION DISRUPTS BILE ACID HOMEOSTASIS AND SIGNALLING RECEPTOR ACTIVATION IN THE MURINE SMALL INTESTINE TO POTENTIALLY IMPACT GUT IMMUNITY

Background

Helminths (parasitic worms) use immunomodulatory mechanisms to maintain their presence in the host intestines. Understanding how helminths reduce inflammation in the guts may lead to new therapeutic options for inflammatory bowel diseases. Our lab uses a helminth which infects the proximal small intestine of mice to identify new, potentially immunomodulatory molecules. In this project, we examined the impact of helminth infection on bile acids (BA)s; a class of metabolites that can function as immunomodulatory signalling molecules. To our knowledge, how helminth infection alters BA homeostasis, and the potential consequences for proximal small intestine immunity have not yet been reported.

Purpose

Our aims were to determine whether helminth infection alters (1) the intestinal BA pool, (2) expression of BA transporters in the small intestine, and (3) expression and/or activation of the Farnesoid X receptor (FXR), a BA signalling receptor.

Method

We used a murine model system to study the effects of the mouse-specific helminth Heligmosomoides polygyrus on BA homeostasis, BA transporter gene expression, and BA signalling receptors in the small intestine. Male and female littermate mice were used. Targeted metabolomics was used to assess the composition of the BA pool in the small intestine. Reverse transcription qPCR was used to quantify gene expression of BA transporters/signalling molecules in tissues. All data were segregated by sex of mice for data analysis.

Result(s)

We found that helminth infection disrupts the BA pool of mice, with consistent reductions in T-CDCA and T-αMCA during helminth infection. In the proximal small intestine, expression of the genes that encode the apical sodium dependant BA transporter (ASBT) and organic solute transporter alpha (OSTα) were unaffected during helminth infection, however expression of the organic solute transporter β (OSTβ) gene, which encodes half of the basal BA transporter, was decreased. Expression of Shp-1, an indicator of activation of BA receptor FXR, and expression of the Fxr gene were significantly decreased in both the proximal and distal small intestine. Lastly, expression of the gene encoding Gpbar1 trended upwards in the proximal and distal small intestine of female mice.

Conclusion(s)

Infection of mice with a proximal small intestine-dwelling helminth impacts BA homeostasis in the small intestine. Helminth infection decreases expression of a BA transporter in the proximal small intestine, although whether this contributes to or is caused by perturbations in the BA pool during infection remains to be seen. The downregulation of BA signalling we see during helminth infection in the proximal small intestine points to a potential functional impact on the host immune response which we now intend to explore. Understanding the immunomodulatory mechanisms used by helminths to dampen the host immune response could lead to further advancements in treating intestinal inflammatory disorders such as Crohn’s and Colitis.

Disclosure of Interest

None Declared

Caregivers' perspectives on the contextual influences within family management for ethnically diverse children with ADHD

PURPOSE

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder affecting over 9% of children in the United States. Family caregivers are often responsible for the management of their child's ADHD. Contextual influences, such as healthcare providers, systems, and resources, are factors contributing to the ease or difficulty of family management. The purpose of this article is to qualitatively describe the major contextual influences that impact family management for ethnically diverse children with ADHD.

DESIGN AND METHODS

This analysis is part of a mixed methods study using a concurrent nested design (QUAL + quant) to understand the phenomenon of family management from a contextual and socioecological perspective. In this analysis, cross-sectional data from caregivers of children with ADHD (N = 50) within a large northeastern city in the United States were collected, analyzed, and interpreted in the qualitative descriptive tradition. Semistructured interviews were conducted with participants to understand the contextual influences within family management. Conventional content analysis resulted in the emergence of barrier and facilitator domains and subdomains.

RESULTS

Caregivers were predominantly female (98%) and between 24 and 61 years with a mean age of 37.54 (SD = 1.18). Caregivers identified their children as Black or African American (56%), White (26%), Multi-Racial (16%), Hispanic or Latinx (8%), and Asian (2%). Contextual influences within family management emerged as barrier or facilitator domains. Barrier domains included: (1) family, (2) healthcare systems, (3) educational systems, (4) stigma, and (5) financial, insurance, and policy issues. Facilitator domains included: (1) family and community, (2) healthcare providers, and (3) educational providers. Subdomains within each domain are expanded in the article.

PRACTICE IMPLICATIONS

Specialists in pediatric nursing should consider contextual influences within family management for ethnically diverse children with ADHD. As healthcare providers, it is important to recognize system-level barriers or facilitators for caregivers and their children and find creative ways to overcome obstacles and leverage strengths within families, communities, and care systems. Another important area for pediatric specialists to consider is understanding how stigma impacts children with ADHD. Policy-level engagement and advocacy should maximize the political will of nurses, families, and educators to create change within communities.

The association of motivation and perceived social norms with eating behaviors in emerging adults

Objective

This study examines the associations of eating-related motivation, perceived norms, and their interaction with eating behaviors in emerging adults.

Design

Data are from the NEXT Generation Health Study, a nationally representative sample of US emerging adults. Binominal logistic regression analyses estimated associations of eating behaviors with self-determined motivation, non-self-determined motivation, and perceived social norms. Multiplicative interaction terms between each motivation construct and perceived social norms were tested in the models.

Results

Self-determined motivation was positively associated with intake frequency of whole grains, low-fat dairy, and fruit and vegetables. Soda intake frequency was inversely associated with greater non-self-determined motivation, but not self-determined motivation or perceived social norms. Perceived social norms were positively associated with the intake of whole grains, low-fat dairy, and fruit and vegetables. Perceived social norms did not moderate the association of motivation constructs with eating behaviors.

Conclusion

Self-determined motivation and perceived social norms may be considered in intervention targeting healthful eating behaviors in emerging adults.

Anabolic agents: what is beyond osteoporosis?

Osteoporosis is a common skeletal disorder characterized by low bone mass, which leads to reduced bone strength and an increased risk of fractures. Anabolic agents have been shown to improve bone mass and decrease fracture risk in osteoporosis patients by directly stimulating osteoblasts to produce new bone. Currently, two anabolic agents are available in the USA: recombinantly produced teriparatide (TPTD), which is the fully active (1-34) amino active sequence of human parathyroid hormone (PTH), and abaloparatide (APTD), a synthetic analog of parathyroid hormone-related peptide (PTHrP). At present, both agents are approved only for treatment of patients with osteoporosis at high risk of fracture. Nonetheless, their anabolic properties have led to off-label application in additional settings which include spine fusion, osteonecrosis of the jaw, arthroplasty, and fracture healing. In this article, we summarize available scientific literature regarding the efficacy, effectiveness, and safety of TPTD in these off-label settings.

The Answer is Vitamin D! From Pediatrics to Geriatrics in Orthopaedics

Vitamin D is necessary for the regulation of calcium and phosphate in the human body. Decreased vitamin D levels can alter the bone mineralization process. The prevalence of vitamin D deficiency in the general population is high, and low vitamin D levels are associated with disorders such as rickets and osteoporosis. As knowledge about vitamin D metabolism increases, physicians of all specialties are becoming more attentive to the vitamin D status of their patients. Similarly, orthopaedic surgeons, through various initiatives such as "Own the Bone," are making greater efforts to medically manage skeletal disorders. Unfortunately, universal guidelines for the optimization of vitamin D levels have not been adopted by orthopaedic surgeons, and, despite substantial efforts, vitamin D is not an integral part of most orthopaedic residency training programs. Although this may be partially attributed to attitudes among orthopaedic surgeons, the large number of vitamin D recommendations in the literature may be confusing and require substantial effort to synthesize into a viable approach for a given patient. Despite this confusion, orthopaedic surgeons should understand how to diagnose and manage disorders related to vitamin D and calcium deficiency.

Surgery for a fracture of the hip within 24 hours of admission is independently associated with reduced short-term post-operative complications

AIMS

We aimed to characterise the effect of expeditious hip fracture surgery in elderly patients within 24 hours of admission on short-term post-operative outcomes.

PATIENTS AND METHODS

Patients age 65 or older that underwent surgery for closed femoral neck and intertrochanteric hip fractures were identified from the American College of Surgeons National Surgical Quality Improvement Program between 2011 and 2014. Multivariable propensity-adjusted logistic regressions were performed to determine associations between early surgery within 24 hours and post-operative complications, controlling for selection bias in patients undergoing early surgery based on observable characteristics.

RESULTS

A total of 26 051 patients were included in the study; 5921 (22.7%) had surgery within 24 hours of admission, while 20 130 (77.3%) patients had surgery after 24 hours. Propensity-adjusted multivariable logistic regressions demonstrated that surgery within 24 hours was independently associated with lower odds of respiratory complications including pneumonia, failure to extubate, or reintubation (odds ratio (OR) 0.78, 95% confidence interval (CI) 0.67 to 0.90), and extended length of stay (LOS) defined as ≥ 6 days (OR 0.84, 95% CI 0.78 to 0.90).

CONCLUSION

In elderly patients with hip fractures, early surgery within 24 hours of admission is independently associated with less pulmonary complications including pneumonia, failure to extubate, and reintubation, as well as shorter LOS. Cite this article: Bone Joint J 2017;99-B:1216-22.

Patients with prior vertebral or hip fractures treated with teriparatide in the Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) observational study

SUMMARY

In patients in the Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) observational study with and without a prior vertebral or hip fracture, the incidence of nonvertebral fractures was lower with >6 months of teriparatide treatment than during the first 6 months.

INTRODUCTION

Clinical evidence on the effect of teriparatide in patients with prior fracture is limited. In the DANCE observational study, the incidence of nonvertebral fragility fractures (NVFX) decreased significantly in patients receiving teriparatide for >6 months (6-24 months) versus >0 to ≤6 months (reference period).

METHODS

We performed a post hoc analysis to assess the effect of teriparatide 20 μg/day in patients who entered DANCE with prior vertebral or hip fractures. The incidence of patients experiencing a NVFX for four 6-month intervals during and after treatment was compared with the reference period.

RESULTS

Overall, 4085 patients received ≥1 dose of teriparatide. Of 3720 with sufficient data for efficacy analysis, 692 had prior vertebral fracture, including 179 with previous kyphoplasty/vertebroplasty; 290 had prior hip fracture. These patients were older, and those with prior vertebral fractures had more comorbid conditions at baseline than those without prior vertebral fractures. The incidence of patients experiencing NVFX declined over time in all patient groups. The fracture incidence rate declined 49 and 46%, respectively, in patients with and without prior vertebral fracture and was 63 and 46% lower in patients with previous kyphoplasty/vertebroplasty and without prior vertebral fracture. NVFX declined 43 and 48% in patients with and without prior hip fracture. The reduced incidence over time was consistent in the subgroups (all interaction p values >0.05). Patients with prior fracture were more likely to experience serious adverse events.

CONCLUSION

The incidence of NVFX decreased over time in patients receiving teriparatide in DANCE regardless of prior fracture status.

Effect of osteoporosis medications on fracture healing

Antiosteoporotic medications are often used to concurrently treat a patient's fragility fractures and underlying osteoporosis. This review evaluates the existing literature from animal and clinical models to determine these drugs' effects on fracture healing. The data suggest that these medications may enhance bone healing, yet more thorough prospective studies are warranted. Pharmacologic agents that influence bone remodeling are an essential component of osteoporosis management. Because many patients are first diagnosed with osteoporosis when presenting with a fragility fracture, it is critical to understand how osteoporotic medications influence fracture healing. Vitamin D and its analogs are essential for the mineralization of the callus and may also play a role in callus formation and remodeling that enhances biomechanical strength. In animal models, antiresorptive medications, including bisphosphonates, denosumab, calcitonin, estrogen, and raloxifene, do not impede endochondral fracture healing but may delay repair due to impaired remodeling. Although bisphosphonates and denosumab delay callus remodeling, they increase callus volume and result in unaltered biomechanical properties. Calcitonin increases cartilage formation and callus maturation, resulting in improved biomechanical properties. Parathyroid hormone, an anabolic agent, has demonstrated promise in animal models, resulting in accelerated healing with increased callus volume and density, more rapid remodeling to mature bone, and improved biomechanical properties. Clinical data with parathyroid hormone have demonstrated enhanced healing in distal radius and pelvic fractures as well as postoperatively following spine surgery. Strontium ranelate, which may have both antiresorptive and anabolic properties, affects fracture healing differently in normal and osteoporotic bone. While there is no effect in normal bone, in osteoporotic bone, strontium ranelate increases callus bone formation, maturity, and mineralization; forms greater and denser trabeculae; and improves biomechanical properties. Further clinical studies with these medications are needed to fully understand their effects on fracture healing in order to simultaneously treat fragility fractures and underlying osteoporosis.

Cardiovascular Considerations for Joint Replacement Surgery

Heart disease is the leading cause of death in the United States. Cardiovascular complications are associated with higher morbidity and mortality rates for patients who undergo orthopaedic surgery. Therefore, the clinical importance of a comprehensive preoperative evaluation and medical clearance is crucial and may substantially improve postoperative outcomes. A thorough knowledge of cardiovascular perioperative planning and management can enable healthcare professionals to identify patients who are potentially at risk for cardiovascular complications, and eventually improve both short- and long-term patient outcomes and satisfaction.

Perioperative Treatment of Patients with Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disease mediated by a widespread, chronic, and systematic inflammatory process that causes joint deterioration, which leads to pain, disability, and poor quality of life. The increased use of disease-modifying antirheumatic drugs has been shown to markedly slow disease progression, which has translated into a decrease in the need for orthopaedic intervention in this population. However, in a substantial percentage of patients with the disease, optimal pharmacologic treatment fails and surgical intervention is required. A thorough understanding of medical considerations in these patients and improved knowledge of the medical complications caused by the disease process and the pharmacologic therapy used to treat it may lead to improved preoperative planning and medical clearance, which may ultimately improve the overall postoperative outcome.

Effect of Vitamin D on Joint Replacement Outcomes

Vitamin D is a steroid hormone that affects not only bone metabolism and strength but also a variety of musculoskeletal health and surgical outcomes that are relevant to orthopaedic medicine. Risk factors for vitamin D deficiency include sex, age, skin pigmentation, obesity, and preexisting conditions such as nephritic syndrome and malabsorption syndrome. Furthermore, vitamin D deficiency is associated with the development of postoperative complications, such as an increased risk of infection, morbidity, and mortality. The standardization of vitamin D terminology as well as a thorough understanding of the medical considerations associated with vitamin D deficiency can improve preoperative planning and clearance, and, ultimately, patient outcomes and satisfaction.

Effect of Smoking on Joint Replacement Outcomes: Opportunities for Improvement Through Preoperative Smoking Cessation

Because orthopaedic surgeons focus on identifying serious potential complications, such as heart attack, stroke, and deep vein thrombosis, during the preoperative assessment, correctable factors, such as smoking, may be overlooked. Chronic exposure to nicotine has been correlated with perioperative complications that lead to worse outcomes, including decreased patient satisfaction, longer hospitalization periods, and an increased rate of hospital readmission. It has been proven that smoking is a negative risk factor for decreased bone mineral density, which leads to increased fracture risk, heightened pain, postoperative wound and bone healing complications, decreased fusion rates, and postoperative tendon and ligament healing complications. Physician-led preoperative smoking cessation programs that include, but are not limited to, pharmacotherapy plans have been shown to improve primary surgical outcomes and smoking cessation rates. Smoking has detrimental effects on specialty-specific physiology; however, there are many effective options for intervention that can improve primary outcomes.

Theoretical consideration of the effect of drug holidays on BMD and tissue age

It has been suggested that some patients undergoing prolonged treatment for osteoporosis with anti-resorptive agents may benefit from discontinuing treatment. Here we use a computer simulation of bone cell activity to estimate changes in bone mineral density (BMD) and tissue age when treatment is discontinued.

INTRODUCTION

Although anti-resorptive agents are effective at reducing fracture risk, questions remain regarding how long patients should continue treatment and how long treatment should be discontinued. Suspending treatment as part of a drug holiday may reduce the risk of adverse effects, but may also lead to reduced BMD.

METHODS

We use a computer simulation of the bone remodeling process to estimate how BMD and mean tissue age are changed after treatment is suspended. Mean tissue age is studied because increased tissue age has been associated with impaired bone quality and has been linked to the risk of adverse effects.

RESULTS

Our simulations suggest that BMD gains from anti-resorptive therapy can be lost over time, especially with anti-resorptive agents that have little residual effects. With regard to mean tissue age, the simulations suggest that increases in tissue age from anti-resorptive treatment are long lasting; increases in mean tissue age caused by treatment may remain for as long as 15 years after treatment is suspended. After stopping treatment, reductions in BMD are expected to occur long before mean tissue age returns to normal.

CONCLUSIONS

Our simulations suggest that, when using a long-lasting anti-resorptive agent, 1- to 5-year drug holidays may have little effect on BMD in most patients but that drug holiday intervals that maintain BMD are unlikely to reverse alterations in tissue age caused by treatment. Our analysis echoes recent reviews suggesting patient selection and monitoring when anti-resorptive treatment is discontinued.

Osteoporosis drug therapy strategies in the setting of disease-modifying agents for autoimmune disease

The purpose of this systematic review is to evaluate the effects of methotrexate (MTX) and tumor necrosis factor-alpha (TNF-α) inhibitors on bone mineral properties in the clinical literature. A systematic review of the literature identifying relevant case reports, population-based studies, cohort studies, case control studies, and randomized controlled trials in Pubmed and Web of Science databases from inception to December 31, 2011 was conducted. The following keywords were used: "bone turnover," "bone mineral density," "TNF-α inhibitors," "infliximab," "adalimumab," "etanercept," and "MTX." The bibliographies of all retrieved studies were also reviewed to identify additional articles. Based on these results, a rational drug therapy strategy was suggested for treating osteoporosis in patients with inflammatory disease. MTX and TNF-α inhibitors do not appear to have an adverse effect on BMD in patients with inflammatory disease. Their negative effects on BMD and bone turnover in pre-clinical models appear to be outweighed by their anti-disease effects in clinical studies. Treatment with MTX or TNF-α inhibitors has no adverse effect on BMD in patients with inflammatory disease. Future studies will focus on developing optimal drug strategies when combining DMARDs with anti-osteoporotic agents in this patient population.

The effects of ABCG5/G8 polymorphisms on HDL-cholesterol concentrations depend on ABCA1 genetic variants in the Boston Puerto Rican Health Study

BACKGROUND AND AIMS

ATP-binding cassette transporters G5/G8 (ABCG5/G8) are associated with HDL-C concentrations. To assess whether the effect of ABCG5/G8 genetic variants on HDL-C concentrations is dependent on ATP-binding cassette transporters A1 (ABCA1), we studied potential interactions between single nucleotide polymorphisms (SNPs) at ABCG5/G8 (i7892T > C, 5U145A > C, T54CA > G, T400KC > A) and ABCA1 (i27943G > A, i48168G > A, K219RG > A, i125970G > C, 3U8995A > G) genes with HDL-C concentrations.

METHODS AND RESULTS

ABCG5/G8 and ABCA1 SNPs were genotyped in 788 subjects (228 men and 560 women) who participated in the Boston Puerto Rican Health Study. Biochemical measurements were determined by standard procedures. Genotyping was performed using TaqMan assays according to routine laboratory protocols. Significant gene-gene interactions for HDL-C were found between ABCG8 (5U145A > C, T54CA > G, T400KC > A) SNPs and ABCA1_i48168G > A genetic variant (P = 0.009, P = 0.042 and P = 0.036, respectively), in which carriers of the 5U145C and 54C alleles, and homozygotes for the T400 allele at ABCG8 genetic variants displayed lower HDL-C concentrations than homozygotes for the 5U145A and T54 alleles, and heterozygotes for the 400K allele at ABCG8 SNPs, only if they were also homozygous for the minor allele (A) at the aforementioned ABCA1 SNP.

CONCLUSIONS

The gene-gene interactions reported in the present study support the hypothesis that the effect of ABCG5/G8 genetic variants on HDL-C concentrations is dependent on ABCA1 expression. Replication of these analyses to further populations, particularly with low HDL-C, is clearly warranted.

Fragility fractures of the hip and femur: incidence and patient characteristics

SUMMARY

Using national discharge and medical claims data, we studied the epidemiology of femoral fractures from 1996 to 2006. The annual hip fracture incidence declined from 600/100,000 to 400/100,000, without decline in the more rare femur fractures. Incidence rates for subtrochanteric and femoral shaft fractures were each below 20 per 100,000.

INTRODUCTION

This study's purpose is to describe the site-specific epidemiology of femur fractures among people aged 50 and older.

METHODS

Using the National Hospital Discharge Survey from 1996 to 2006 and a large medical claims database (MarketScan), we studied epidemiology of all femur fractures. Hip fractures were grouped together; subtrochanteric, shaft, and distal femur fractures were kept separate.

RESULTS

In females, the overall hospital discharge rates of hip fracture decreased from about 600/100,00 to 400/100,000 person-years from 1996 to 2006. Subtrochanteric, femoral shaft, and lower femur rates remained stable, each approximately 20 per 100,000 person-years. Similar trends but lower rates existed in males. No significant trends were found in any of these fractures during the more recent years of 2002-2006 (MarketScan data). Using MarketScan, the overall incidence of hip fracture was <300/100,000 person-years; incidence of subtrochanteric and femoral shaft fractures combined was <25/100,000 person-years and distal femur fracture incidence was <18/100,000 person-years in females; rates were lower in males. The incidence of hip and other femur fractures increased exponentially with age.

CONCLUSIONS

We found no evidence of an increasing incidence of any femoral fracture. Hip fracture incidence is declining but the incidence of each of the more rare femur fractures (distal to the lesser trochanter) is stable over time.

Vertebral height restoration in osteoporotic compression fractures: kyphoplasty balloon tamp is superior to postural correction alone

INTRODUCTION

Kyphoplasty has been shown to restore vertebral height and sagittal alignment. Proponents of vertebroplasty have recently demonstrated that many vertebral compression fractures (VCFs) are mobile and positional correction can lead to clinically significant height restoration. The current investigation tested the hypothesis that positional maneuvers do not achieve the same degree of vertebral height correction as kyphoplasty balloon tamps for the reduction of low-energy VCFs.

METHODS

Twenty-five consecutive patients with a total of 43 osteoporotic VCFs were entered into a prospective analysis. Each patient was sequentially evaluated for postural and balloon vertebral fracture reduction. Preoperative standing and lateral radiographs of the fractured vertebrae were compared with prone cross-table lateral radiographs with the patient in a hyper-extension position and on pelvic and sternal rolls. Following positional manipulation, patients underwent a unilateral balloon kyphoplasty. Postoperative standing radiographs were evaluated for the percentage of height restoration related to positioning and balloon kyphoplasty.

RESULTS

In the middle portion of the vertebrae, the percentage available for restoration restored with extension positioning was 10.4% (median 11.1%) and after balloon kyphoplasty was 57.0% (median 62.2%). This difference was statistically significant (p<0.001). Thus, kyphoplasty provided an additional 46.6% of the height available for restoration from the positioning alone. With operative positioning, 51.2% of VCFs had >10% restoration of the central portion of the vertebral body, whereas 90.7% of fractures improved at least 10% following balloon kyphoplasty (p<0.002).

CONCLUSION

Although this study supports the concept that many VCFs can be moved with positioning, balloon kyphoplasty enhanced the height reduction >4.5-fold over the positioning maneuver alone and accounted for over 80% of the ultimate reduction. If height restoration is the goal, kyphoplasty is clearly superior in most cases to the positioning maneuver alone.

Mass vaccination and surveillance/containment in the eradication of smallpox

The Smallpox Eradication Program, initiated by the WHO in 1966, was originally based on mass vaccination. The program emphasized surveillance from the beginning, largely to track the success of the program and further our understanding of the epidemiology of the disease. Early observations in West Africa, bolstered by later data from Indonesia and the Asian subcontinent, showed that smallpox did not spread rapidly, and outbreaks could be quickly controlled by isolation of patients and vaccination of their contacts. Contacts were usually easy to find because transmission of smallpox usually required prolonged face-to-face contact. The emphasis therefore shifted to active searches to find cases, coupled with contact tracing, rigorous isolation of patients, and vaccination and surveillance of contacts to contain outbreaks. This shift away from mass vaccination resulted in an acceleration of the program's success.

Prevention and treatment of osteoporotic fractures

With the aging international population, osteoporosis has become an epidemic. This painless disease is characterized by a decreased bone mass, resulting in decreased structural integrity of bone, and often goes undiagnosed. Typical osteoporotic fractures include vertebrae, hip, and wrist fractures, and these may have a dramatic impact on quality of life, even if the fracture is successfully treated. Many antiresorptive agents have demonstrated the ability to reduce the risk of osteoporotic fractures, and newer anabolic agents may further reduce risk. Non-medical treatments, such as external hip protectors and balance and low-impact strength training, are also very effective in preventing fractures. Before specific treatments can be addressed, however, osteoporosis must first be considered as a diagnosis in any patient with a low-energy fracture. This requires continued public health initiatives involving patient and physician education regarding the necessity for bone mass measurement and the merits of antiresorptive therapy.

Antioxidant treatment for amyotrophic lateral sclerosis / motor neuron disease

BACKGROUND

Free radical accumulation and oxidative stress have been proposed as contributing to the progression of amyotrophic lateral sclerosis (or motor neuron disease). A range of antioxidant medications are available, and have been studied.

OBJECTIVES

To examine the effects of antioxidant medication in the treatment of people with amyotrophic lateral sclerosis.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group trials register (July 2003), MEDLINE (from January 1966 to July 2003), EMBASE (from January 1980 to July 2003) and other sources.

SELECTION CRITERIA

All randomized or quasi-randomized controlled trials of antioxidant treatment for amyotrophic lateral sclerosis.

DATA COLLECTION AND ANALYSIS

The reviewers independently applied the selection criteria, assessed study quality and two reviewers performed independent data extraction.

MAIN RESULTS

The search identified 21 studies for consideration but only eight studies met the inclusion criteria. Only two studies used our predetermined primary outcome measure, (survival at 12 months treatment). Sufficient data were available from three studies to allow analysis of the primary outcome measure, and a meta-analysis was performed. In the individual studies no significant effect was observed of vitamin E 500 mg twice daily; acetylcysteine 50 mg/kg daily subcutaneous infusion; or a combination of L-methionine 2 g, vitamin E 400 International Units, and selenium 3 x 10-5g three times daily (Alsemet). No significant effect on the primary outcome measure was observed in a meta-analysis of antioxidants in general when combining the results. No significant differences were demonstrated in secondary outcome measures.

REVIEWERS' CONCLUSIONS

There is insufficient evidence of efficacy of individual antioxidants, or antioxidants in general, in the treatment of people with amyotrophic lateral sclerosis. One study reported a mild positive effect, but this was not supported by the analysis we used. Generally the studies were poorly designed, and underpowered, with low numbers of participants and of short duration. Further well-designed trials of medications such as vitamin C and E are unlikely to be performed. If future trials of antioxidant medications are performed, careful attention should be given to sample size, outcome measures, and duration of the trial. The high tolerance and safety, and relatively low cost of vitamins C and E, and other considerations related to the lack of other effective treatments for amyotrophic lateral sclerosis, explain the continuing use of these vitamins by physicians and patients. While there is no substantial clinical trial evidence to support their clinical use, there is no clear contraindication.

The osteoporotic spine

Osteoporotic vertebral fractures represent the most common type of osteoporotic fracture. They can cause significant morbidity and mortality, including physical, functional, and psychosocial impairments. Screening using fracture risk assessments can identify those at greatest risk. Medical and non-medical comprise appropriate, comprehensive treatment programs. The minimally invasive spine procedures vertebroplasty and kyphoplasty can help to significantly reduce pain and deformity in patients with severe pain and deformity from vertebral fracture.

Farm residence and exposures and the risk of allergic diseases in New Zealand children

BACKGROUND

Studies in Europe have reported a reduced prevalence of allergy in farmers' children. We aimed to determine if there is a similar reduction in allergy among New Zealand farm children.

METHODS

Two hundred and ninety-three children participated (60%) aged 7-10 years, from selected schools in small towns and the surrounding rural area. Skin prick tests (SPT) to eight common allergens were performed. Parents completed questionnaires about allergic and infectious diseases, place of residence, exposure to animals, and diet, and they provided dust from the living-room floor. Endotoxin was measured using an Limulus amoebocyte lysate (LAL) assay and Der p 1 using enzyme-linked immunoassay (ELISA).

RESULTS

Current farm abode was found to increase the risk of having symptoms associated with allergy, but not SPT positivity. Independent inverse associations were found for early-life exposures: at least weekly consumption of yoghurt with hayfever (odds ratio (OR) = 0.3, 95% confidence intervals (CI) 0.1-0.7) and allergic rhinitis (OR = 0.3, 95% CI 0.2-0.7); any unpasteurized milk consumption with atopic eczema/dermatitis syndrome (AEDS) (OR = 0.2, 95% CI 0.1-0.8); cats inside or outside with hayfever (OR = 0.4, 95% CI 0.1-1.0) and AEDS (OR = 0.4, 95% CI 0.2-0.8); dogs inside or outside with asthma (OR = 0.4, 95% CI 0.2-0.8); and pigs with SPT positivity (OR = 0.2, 95% CI 0.1-0.9).

CONCLUSIONS

Despite finding a protective effect of early-life animal exposures, we found a greater prevalence of allergic disease on farms.

Patellar metastasis from a squamous carcinoma of the lung: a case report

Bone is a common site of metastasis from lung cancer. Metastasis to the patella, however, is rare. A 76-year-old man presented with knee pain caused by an isolated patellar metastasis from squamous cell carcinoma of the lung. Treatment was delayed secondary to delay in diagnosis. In cases of bone pain that are unexplained or out of proportion to a traumatic event, more extensive diagnostic studies should be done.

Rehabilitation for limb salvage patients: kinesiological parameters and psychological assessment

Osteosarcoma is the most frequently occurring primary malignant tumor of bone, especially in adolescence. Treatment involves either limb salvage surgery or amputation with neoadjuvant chemotherapy. This review article discusses the current treatment modalities for osteosarcoma and also compares the gait patterns and psychosocial profiles of patients treated with either limb salvage surgery or amputation for osteosarcoma. Contemporary orthopedic literature on therapeutic options for osteosarcoma patients is reviewed. Background information on the basic principles of kinesiology, with emphasis on studies of gait pattern differences among patients treated with limb salvage versus amputation, is presented. Finally, several studies of the psychologic profiles of patients after these two procedures for osteosarcoma are reviewed. Trends in contemporary orthopedic literature suggest that functional outcomes, in terms of kinesiologic parameters, are comparable for patients treated with either limb salvage or amputation. Both sets of patients reported quality-of-life problems, including difficulty retaining health insurance and finding appropriate employment, social isolation, and poor self-esteem. The management of patients with osteosarcoma includes not only an individualized surgical plan for each patient but also includes awareness of the patients' psychologic and social needs after surgery.

Comparative study of the activity of total hip arthroplasty patients and normal subjects

The walking activity of normal subjects and total hip arthroplasty (THA) patients from the Wrightington Hospital for Joint Disease and The General Infirmary at Leeds was assessed by means of electronic pedometers. The principal objectives were to establish the extent to which joint arthroplasty patients recover their activity relative to normal subjects and to establish the number of loading cycles to which prostheses should be subjected in joint simulator studies of implant performance. A further objective was to establish an experimental procedure for the assessment of the role of activity in contributing to the well-known scatter in the measurements of femoral head penetration into acetabular cups in in vivo studies of implant performance. The last-mentioned issue is addressed in another article ([1]). The walking activity of 2 normal subjects of disparate ages was assessed during 1 full year. It was concluded that fair estimates of activity could be achieved by recording pedometer readings during successive 2- to 4-week periods. This approach was adopted in the full assessment of the walking activity of cohorts of normal subjects and THA patients. Linear regression expressions relating the number of steps taken daily and the annual number of loading cycles on each leg to age are presented for normal subjects and THA patients. In all cases, activity declines with age, but it is shown that total joint arthroplasty is not at all restrictive on walking activity-a remarkable testimony to the efficacy of total joint arthroplasty. Attention is drawn, however, to different levels of activity of THA patients recorded in the present United Kingdom study and a similar survey conducted in California.

The effect of activity levels of total hip arthroplasty patients on socket penetration

Survivorship of total hip arthroplasties (THAs) has been linked to penetration of the femoral head into the polyethylene acetabular cup and to polyethylene wear. The activity level of patients with THAs is considered to be an important factor affecting wear, and the purpose of this study was to explore the relationship between activity as recorded by pedometers and cup penetration. The measurement of daily activity levels of normal subjects and THA patients of various ages are discussed in another article ([1]). Subjects were monitored continuously during 2- to 4-week periods using simple pedometer devices. Patients (n = 54; mean age, 58 years) from the Centre for Hip Surgery at Wrightington Hospital for whom the penetration data also were available were included in the study. The average activity level for the patient group was 1.426 million loading cycles on each hip joint per year. Radiographic penetration measurements were compared for 81 hips in 54 patients with a mean follow-up of 13.1 years (range, 1.3-26.4 years). The overall correlation of penetration with implantation period is known to be poor, however, and did not improve significantly when the penetration was plotted against a new parameter that took account of not only implant life, but also the level of activity and patient weight. The considerable scatter of penetration levels was noted to increase with increasing implantation period, which indicates that in the multifactorial problem of polyethylene wear, other factors, particularly femoral head surface finish or polyethylene deterioration, may predominate.

An unexpected outcome during testing of commercially available demineralized bone graft materials: how safe are the nonallograft components?

STUDY DESIGN

Radiographic and histologic analyses of commercially available bone graft materials were performed.

OBJECTIVE

To compare the osteoinductive efficacy of commercially available demineralized bone matrix material.

SUMMARY OF BACKGROUND DATA

The relative in vivo bone formation and toxicology of the nonallograft components the make up various commercially available demineralized bone matrix products are not known.

METHODS

An in vivo bone formation model was used in 30 athymic rats. Six different bone grafting materials were tested in subcutaneous and intermuscular locations. After 4 weeks, radiographic and histologic testing of bone formation was performed.

RESULTS

Eight of nine rats implanted with Grafton demineralized bone matrix products died 1 to 4 days after implantation of the bone graft material. None of the remaining 10 animals implanted with the four other grafting materials died. The experiment was modified and completed with a lower dose of bone graft material. Pathologic analysis indicated that the cause of death was hemorrhagic necrosis of the kidneys, most likely caused by a toxic effect on the glomeruli and tubules. A possible causative factor may have been the glycerol in the graft material.

CONCLUSIONS

Although the volume of Grafton product per kilogram of body weight used in this study was approximately eight times the maximum volume used in humans, the authors believe that this data must be reported because this product is used substantially in clinical settings. In addition, the osteoinductive performance and relative safety of the nonallograft components in all commercially available demineralized bone grafts are not known.