Relationship between Civilian Injuries Caused during Contact with Law Enforcement and Community-Level Sociodemographic Characteristics.

Civilian injuries caused during contact with law enforcement personnel erode community trust in policing, impact individual well-being, and exacerbate existing health inequities. We assessed the relationship between ZIP code-level rates of civilian injuries caused during legal interventions and community-level sociodemographic characteristics using Illinois hospital data from 2016 to 2022. We developed multivariable Poisson regression models to examine whether legal intervention injury rates differed by race-ethnicity and community economic disadvantage across three geographic regions of Illinois representing different levels of urbanization. Over the study period, 4976 civilian injuries were treated in Illinois hospitals (rate of 5.6 per 100,000 residents). Compared to non-Hispanic white residents, non-Hispanic Black residents demonstrated 5.5-10.5 times higher injury rates across the three geographic regions, and Hispanic-Latino residents demonstrated higher rates in Chicago and suburban Cook County, but lower rates in the rest of the state. In most regions, models showed that as the percent of minority residents in a ZIP code increased, injury rates among non-Hispanic Black and Hispanic-Latino residents decreased. As community economic disadvantage increased at the ZIP code level, civilian injury rates increased. Communities with the highest injury rates involving non-Hispanic white residents were significantly more economically unequal and disadvantaged. While the injury rates were consistently and substantially higher among non-Hispanic Black residents throughout the state, the findings illustrate that the association between overall civilian injuries caused during contact with law enforcement and community sociodemographic characteristics varied across regions. Data on local law enforcement agency policies and procedures are needed to better identify appropriate interventions.

Trends in non-fatal and fatal opioid overdoses during the first two years of the coronavirus disease-2019 pandemic.

PURPOSE: This study assessed opioid-involved overdose rates by age, sex, and race-ethnicity across strict pandemic mitigation phases and how this varied across data systems. METHODS: We examined opioid-involved overdoses using medical examiner and hospital data for Cook County, Illinois between 2016-2021. Multivariable segmented regression was used to assess weekly overdose rates across subgroups of age, sex and race/ethnicity and strict pandemic mitigation phases. RESULTS: The overall rate of weekly opioid-involved overdoses increased when assessing the medical examiner (ß = 0.01; 95% CI = 0.01,0.02; P ≤ .001) and emergency department visits data sources (ß = 0.15; 95% CI = 0.09,0.20; P ≤ .001) but not for the hospital admissions data source. We found differences in overdose rates across subgroups and phases of pandemic mandates. Fatal overdoses increased during lockdown-1 while admissions and emergency department (ED) visits for opioid-involved overdoses generally decreased across all phases of pandemic mitigation mandates except for the period following lockdown-1. Across pandemic mitigation phases, Hispanics and individuals under 25 years did not demonstrate any change in admissions and ED visits for overdoses. CONCLUSIONS: We underscore the importance of utilizing multiple sources of surveillance to better characterize opioid-involved overdoses and for public health planning.

Disparities in fatal and non-fatal opioid-involved overdoses among middle-aged non-Hispanic Black Men and Women.

The gap in fatal opioid overdose rates has been closing between non-Hispanic Black and non-Hispanic White individuals. The rising opioid-involved mortality rates among non-Hispanic Black adults has been identified by SAMHSA as a critical public health issue. However, further research is needed that utilizes comprehensive surveillance data on both fatal and non-fatal opioid-involved overdoses to better assess the changing trends and evaluate factors contributing to changing disparities. We conducted an analysis of medical examiner and hospital data for years 2016-2021 from the largest county in Illinois (Cook) to (1) evaluate disparities in non-fatal and fatal opioid-involved overdoses between middle-aged non-Hispanic Black adults and Black adults of other age groups stratified by sex, (2) to assess if disparities exist across middle-aged adults of different race-ethnicities specifically non-Hispanic White and Hispanic-Latino adults, and (3) evaluate factors contributing to the disparities. Fatal opioid overdose rates among middle-aged Black men 45-64 years old were on average 5.3 times higher than Black men of other age groups, and 6.2 times higher than middle-aged non-Black men. Similarly, fatal opioid overdose rates among middle-aged Black women were on average 5.0 times higher than Black women of other age groups, and 4.9 times higher than middle-aged non-Black women. Hospital utilization rates for opioid-involved overdoses showed similar disparities between age groups and race-ethnicities. Findings indicate that stark disparities in rates of opioid-involved overdoses among middle-aged Black men and women are likely attributed to exposure to more lethal opioids, drug variability in local markets, differences in concurrent drug exposures, and lower access to harm reduction, emergent and preventative health services.

Description of Opioid-involved Hospital Deaths that Do Not Have a Subsequent Autopsy.

BACKGROUND: Surveillance systems rely on death records to monitor the most severe outcome of the opioid epidemic. However, few studies have linked data from hospital systems with death records to determine potential undercount of opioid-involved deaths occurring in hospitals. This study describes characteristics of decedents less likely to have an autopsy following an opioid-involved death in hospitals and estimates the resulting undercount. METHODS: A probabilistic data linkage of hospital and medical examiner data involving 4,936 opioid-involved deaths among residents of Cook County, Illinois, US from 2016 to 2019. We included only hospital deaths that met a national case definition and presented with clinical signs of opioid overdose. RESULTS: Decedents had higher odds of not having an autopsy if they were 50+ years, admitted to the hospital (aOR = 3.7: 2.1, 6.5), hospitalized for 4+ days (aOR = 2.2: 1.5, 3.1), and had a comorbid diagnosis of malignant cancer (aOR = 4.3: 1.8, 10.1). However, decedents exposed to heroin and synthetic opioids (aOR = 0.39: 0.28, 0.55), and concurrent exposure to stimulants (aOR = 0.44: 0.31, 0.64) were more likely to have an autopsy). Compared to estimates from the US Centers for Disease Control and Prevention (CDC), we observed undercounts of opioid overdose deaths ranging from 6% to 15%. CONCLUSIONS: Surveillance systems may undercount decedents that do not meet the typical profile of those more likely to have an autopsy, particularly older patients with chronic health conditions. Our undercount estimate likely exists in addition to the estimated 20%-40% undercount reported elsewhere. See video abstract at, http://links.lww.com/EDE/B990 .

Performance of Prostate Health Index in Biopsy Naïve Black Men.

PURPOSE: The Prostate Health Index is validated for prostate cancer detection but has not been well validated for Gleason grade group 2-5 prostate cancer detection in Black men. We hypothesize that the Prostate Health Index has greater accuracy than prostate specific antigen for detection of Gleason grade group 2-5 prostate cancer. We estimated probability of overall and Gleason grade group 2-5 prostate cancer across previously established Prostate Health Index ranges and identified Prostate Health Index cutoffs that maximize specificity for Gleason grade group 2-5 prostate cancer with sensitivity >90%. MATERIALS AND METHODS: We recruited a "cancer-free" Black control cohort (135 patients) and a cohort of biopsy naïve Black men (158) biopsied for elevated prostate specific antigen. Descriptive statistics compared the prostate cancer cases and controls and the frequency of Gleason grade group 2-5 prostate cancer across Prostate Health Index scores. Receiver operating characteristics compared the discrimination of prostate specific antigen, Prostate Health Index and other prostate specific antigen related biomarkers. Sensitivity and specificity for Gleason grade group 2-5 prostate cancer detection were assessed at prostate specific antigen and Prostate Health Index thresholds alone and in series. RESULTS: Of biopsied subjects 32.9% had Gleason grade group 2-5 prostate cancer. In Blacks with prostate specific antigen from 4.0-10.0 ng/ml, Prostate Health Index and prostate specific antigen had similar discrimination for Gleason grade group 2-5 prostate cancer (0.63 vs 0.57, p=0.27). In Blacks with prostate specific antigen ≤10.0, a threshold of prostate specific antigen ≥4.0 had 90.4% sensitivity for Gleason grade group 2-5 prostate cancer; a threshold of prostate specific antigen ≥4.0 with Prostate Health Index ≥35.0 in series avoided unnecessary biopsy in 33.0% of men but missed 17.3% of Gleason grade group 2-5 prostate cancer. Prostate specific antigen ≥4.0 with Prostate Health Index ≥28.0 in series spared biopsy in 17.9%, while maintaining 90.4% sensitivity of Gleason grade group 2-5 prostate cancer. CONCLUSIONS: The Prostate Health Index has moderate accuracy in detecting Gleason grade group 2-5 prostate cancer in Blacks, but Prostate Health Index ≥28.0 can be safely used to avoid some unnecessary biopsies in Blacks.

Engaging African American Men as Citizen Scientists to Validate a Prostate Cancer Biomarker: Work-in-Progress.

BACKGROUND: African American men (AAM) are under-represented in prostate cancer (PCa) research despite known disparities. Screening with prostate-specific antigen (PSA) has low specificity for high-grade PCa leading to PCa over diagnosis. The Prostate Health Index (PHI) has higher specificity for lethal PCa but needs validation in AAM. Engaging AAM as citizen scientists (CSs) may improve participation of AAM in PCa research.Results and Lessons Learned: Eight CSs completed all training modules and 139 AAM were recruited. Challenges included equity in research leadership among multiple principal investigators (PIs) and coordinating CSs trainings. CONCLUSIONS: Engaging AAM CSs can support engaging/recruiting AAM in PCa biomarker validation research. Equity among multiple stakeholders can be challenging, but proves beneficial in engaging AAM in research. OBJECTIVES: Assess feasibility of mobilizing CSs to recruit AAM as controls for PHI PCa validation biomarker study. METHODS: We highlight social networks/assets of stakeholders, CSs curriculum development/implementation, and recruitment of healthy controls for PHI validation.

Heat-related deaths among construction workers in the United States.

BACKGROUND: Heat is a severe hazard for construction workers and may be worsening with global warming. This study sought to explore heat-related deaths among U.S. construction workers and a possible association with climate change. METHODS: Heat-related deaths in the Census of Fatal Occupational Injuries from 1992 to 2016 were analyzed. Denominators estimated from the Current Population Survey were matched with demographic and occupational categories in rate calculations. Statistical tests were used to examine heat-related deaths in relation to time, geographic region, and temperature. RESULTS: Construction workers, comprising 6% of the total workforce, accounted for 36% (n = 285) of all occupational heat-related deaths from 1992 to 2016 in the U.S. Mean temperatures from June to August increased gradually over the study period. Increasing summer temperatures from 1997 to 2016 were associated with higher heat-related death rates (r = 0.649; 95% confidence interval: 0.290, 0.848). Compared to all construction workers (risk index = 1), statistically significant elevated risk of heat-related death was found among Hispanics (1.21), in particular workers born in Mexico (1.91). Occupations with a high risk index included cement masons (10.80), roofers (6.93), helpers (6.87), brick masons (3.33), construction laborers (1.93) and heating, air conditioning, and refrigeration mechanics (1.60). CONCLUSIONS: U.S. construction workers are at a high risk of heat-related death, and this risk has increased with climate change over time. Effective workplace interventions, enhanced surveillance, and improved regulations and enforcement should accompany broader efforts to combat global warming. The construction industry can help reduce global warming through increased implementation of green building principles.

A 5-Year Retrospective Analysis of Legal Intervention Injuries and Mortality in Illinois.

There has been a public outcry for the accountability of law enforcement agents who kill and injure citizens. Epidemiological surveillance can underscore the magnitude of morbidity and mortality of citizens at the hands of law enforcement. We used hospital outpatient and inpatient databases to conduct a retrospective analysis of legal interventions in Illinois between 2010 and 2015. We calculated injury and mortality rates based on demographics, spatial distribution, and cause of injury. During the study period, 8,384 patients were treated for injuries caused during contact with law enforcement personnel. Most were male, the mean age was 32.7, and those injured were disproportionately black. Nearly all patients were treated as outpatients, and those who were admitted to the hospital had a mean of length of stay of 6 days. Most patients were discharged home or to an acute or long-term care facility (83.7%). It is unclear if those discharged home or to a different medical facility were arrested, accidentally injured, injured when no crime was committed, or injured when a crime was committed. Surveillance of law enforcement-related injuries and deaths should be implemented, and injuries caused during legal interventions should be recognized as a public health issue rather than a criminal justice issue.

Risk factors associated with legal interventions.

BACKGROUND: Current research regarding injuries caused during interactions between police officers and civilians is conducted intermittently or on a very narrow sample frame which provides very little clinical information about the injuries suffered or the adverse outcomes. The aim of this study is to identify comorbid risk factors and describe acute outcomes of medically treated traumatic injuries occurring as a result of contact with law enforcement personnel. METHODS: For this retrospective study, patients injured as a result of contact with law enforcement personnel were identified using ICD-9 external cause of injury codes from medical record databases of patients treated in all hospitals and trauma units in Illinois between 2000 and 2009. RESULTS: A total of 836 cases injured as a result of contact with law enforcement personnel were identified. These patients were more likely to suffer from substance abuse, depression, schizophrenia, and paralytic disorders compared to the reference cases. Persons injured as a result of contact with law enforcement personnel were predominately injured from being man-handled, unarmed blows, firearms or being struck by a blunt object. Although the injury severity did not differ from the comparison group, these patients had longer lengths of hospitalization, a greater proportion of injuries to the back and spine, and a greater proportion required extended care in an intermediate care facility (not a jail) following discharge. CONCLUSIONS: Although medical record data do not explain the detailed circumstances of the face-to-face encounters between law enforcement personnel and civilians, the data provide valuable information regarding who may be at risk of injury and the clinical features of injuries that are suffered following a legal intervention. Similar data systems should be considered to augment existing data systems.

Transcriptomic and functional resources for the small hive beetle Aethina tumida, a worldwide parasite of honey bees.

The small hive beetle (SHB), Aethina tumida, is a major pest of managed honey bee (Apis mellifera) colonies in the United States and Australia, and an emergent threat in Europe. While strong honey bee colonies generally keep SHB populations in check, weak or stressed colonies can succumb to infestations. This parasite has spread from a sub-Saharan Africa to three continents, leading to immense management and regulatory costs. We performed a transcriptomic analysis involving deep sequencing of multiple life stages and both sexes of this species. The assembled transcriptome appears to be nearly complete, as judged by conserved insect orthologs and the ability to find plausible homologs for 11,952 proteins described from the genome of the red flour beetle. Expressed genes include each of the major metabolic, developmental and sensory groups, along with genes for proteins involved with immune defenses and insecticide resistance. We also present a total of 23,085 high-quality SNP's for the assembled contigs. We highlight potential differences between this beetle and its honey bee hosts, and suggest mechanisms of future research into the biology and control of this species. SNP resources will allow functional genetic analyses and analyses of dispersal for this invasive pest. All resources are posted as Supplemental Tables at https://data.nal.usda.gov/dataset/data-transcriptomic-and-functional-resources-small-hive-beetle-aethina-tumida-worldwide, and at NCBI under Bioproject PRJNA256171.

Occupational Injury Surveillance Among Law Enforcement Officers Using Workers' Compensation Data, Illinois 1980 to 2008.

OBJECTIVE: Injuries among law enforcement officers are common, but poorly understood; workers' compensation (WC) data are an underutilized tool for occupational surveillance. METHODS: A stratified analysis of WC claims among four categories of law enforcement officers used descriptive techniques, linear and robust regression. RESULTS: Eighteen thousand eight hundred ninety-two officers filed claims from 1980 to 2008. Correctional officers had the highest rates, with leading causes of falls and assaults; motor vehicle crashes were the most common cause of injury among state police. Total monetary compensation was lower for correctional officers, but was explained by lower time lost and lower average weekly wage. CONCLUSION: The rate and types of injuries varied by subgroups, with correctional officers having the majority of injuries, but lower severity. WC data elucidate causes and outcomes of occupational injuries, which can guide prevention.

tassel-less1 encodes a boron channel protein required for inflorescence development in maize.

tassel-less1 (tls1) is a classical maize (Zea mays) inflorescence mutant. Homozygous mutant plants have no tassels or very small tassels, and ear development is also impaired. Using a positional cloning approach, ZmNIP3;1 (a NOD26-like intrinsic protein) was identified as the candidate gene for tls1. The ZmNIP3;1 gene is completely deleted in the tls1 mutant genome. Two Mutator-insertional TUSC alleles of ZmNIP3;1 exhibited tls1-like phenotypes, and allelism tests confirmed that the tls1 gene encodes ZmNIP3;1. Transgenic plants with an RNA interference (RNAi) construct to down-regulate ZmNIP3;1 also showed tls1-like phenotypes, further demonstrating that TLS1 is ZmNIP3;1. Sequence analysis suggests that ZmNIP3;1 is a boron channel protein. Foliar application of boron could rescue the tls1 phenotypes and restore the normal tassel and ear development. Gene expression analysis indicated that in comparison with that of the wild type or tls1 plants treated with boron, the transition from the vegetative to reproductive phase or the development of the floral meristem is impaired in the shoot apical meristem of the tls1 mutant plants. It is concluded that the tls1 mutant phenotypes are caused by impaired boron transport, and boron is essential for inflorescence development in maize.

Computational fluid dynamics applied to virtually deployed drug-eluting coronary bioresorbable scaffolds: Clinical translations derived from a proof-of-concept.

BACKGROUND: Three-dimensional design simulations of coronary metallic stents utilizing mathematical and computational algorithms have emerged as important tools for understanding biomechanical stent properties, predicting the interaction of the implanted platform with the adjacent tissue, and informing stent design enhancements. Herein, we demonstrate the hemodynamic implications following virtual implantation of bioresorbable scaffolds using finite element methods and advanced computational fluid dynamics (CFD) simulations to visualize the device-flow interaction immediately after implantation and following scaffold resorption over time. METHODS AND RESULTS: CFD simulations with time averaged wall shear stress (WSS) quantification following virtual bioresorbable scaffold deployment in idealized straight and curved geometries were performed. WSS was calculated at the inflow, endoluminal surface (top surface of the strut), and outflow of each strut surface post-procedure (stage I) and at a time point when 33% of scaffold resorption has occurred (stage II). The average WSS at stage I over the inflow and outflow surfaces was 3.2 and 3.1 dynes/cm(2) respectively and 87.5 dynes/cm(2) over endoluminal strut surface in the straight vessel. From stage I to stage II, WSS increased by 100% and 142% over the inflow and outflow surfaces, respectively, and decreased by 27% over the endoluminal strut surface. In a curved vessel, WSS change became more evident in the inner curvature with an increase of 63% over the inflow and 66% over the outflow strut surfaces. Similar analysis at the proximal and distal edges demonstrated a large increase of 486% at the lateral outflow surface of the proximal scaffold edge. CONCLUSIONS: The implementation of CFD simulations over virtually deployed bioresorbable scaffolds demonstrates the transient nature of device/flow interactions as the bioresorption process progresses over time. Such hemodynamic device modeling is expected to guide future bioresorbable scaffold design.

Phenotypic and genetic analyses of the varroa sensitive hygienic trait in Russian honey bee (hymenoptera: apidae) colonies.

Varroa destructor continues to threaten colonies of European honey bees. General hygiene, and more specific Varroa Sensitive Hygiene (VSH), provide resistance towards the Varroa mite in a number of stocks. In this study, 32 Russian (RHB) and 14 Italian honey bee colonies were assessed for the VSH trait using two different assays. Firstly, colonies were assessed using the standard VSH behavioural assay of the change in infestation of a highly infested donor comb after a one-week exposure. Secondly, the same colonies were assessed using an "actual brood removal assay" that measured the removal of brood in a section created within the donor combs as a potential alternative measure of hygiene towards Varroa-infested brood. All colonies were then analysed for the recently discovered VSH quantitative trait locus (QTL) to determine whether the genetic mechanisms were similar across different stocks. Based on the two assays, RHB colonies were consistently more hygienic toward Varroa-infested brood than Italian honey bee colonies. The actual number of brood cells removed in the defined section was negatively correlated with the Varroa infestations of the colonies (r2 = 0.25). Only two (percentages of brood removed and reproductive foundress Varroa) out of nine phenotypic parameters showed significant associations with genotype distributions. However, the allele associated with each parameter was the opposite of that determined by VSH mapping. In this study, RHB colonies showed high levels of hygienic behaviour towards Varroa -infested brood. The genetic mechanisms are similar to those of the VSH stock, though the opposite allele associates in RHB, indicating a stable recombination event before the selection of the VSH stock. The measurement of brood removal is a simple, reliable alternative method of measuring hygienic behaviour towards Varroa mites, at least in RHB stock.

More than training: Community-based participatory research to reduce injuries among hispanic construction workers.

BACKGROUND: Workplace mortality and severe injury are disproportionately distributed among foreign born and Hispanic construction workers. Worker Centers (WCs) provide services and advocacy for low-wage workers and a way for investigators to reach them. The goal of this project is to prevent occupational injuries by increasing awareness of hazards and self-efficacy among foreign born, Hispanic construction workers and by expanding the agenda of WCs to include occupational health and safety (H&S). METHODS: Investigators partnered with eight WCs in seven cities to train worker leaders to deliver a modified OSHA 10-hr curriculum to their peers. RESULTS: Thirty-two worker leaders trained 446 workers over 3 years. There was a demonstrated improvement in knowledge, hazard identification, self-efficacy, and sustainable H&S activities. CONCLUSIONS: This study provides evidence for successful implementation of a training intervention for low wage, low literacy Hispanic construction workers using a community-based participatory research approach.

External and internal detection of Nosema ceranae on honey bees using real-time PCR.

Numerous methods exist for molecular-based detection of Nosema ceranae. Here we determine location of parasite loads, the optimal tissue for pathogen detection, and the likely sources of variability among assays. Bee washes and head/thorax samples revealed substantial N. ceranae loads (2.67×10(4)±1.12×10(4) and 1.83×10(4)±4.14×10(3)). Midgut samples carried the highest parasite loads (3.42×10(6)±1.84×10(6)), followed by the hindgut (5.50×10(5)±3.24×10(5)). We recommend using midgut samples for molecular-based detection and quantification of N. ceranae because of the low variability among samples.

Myosin Gene Expression and Protein Abundance in Different Castes of the Formosan Subterranean Termite (Coptotermes formosanus).

The Formosan subterranean termite (Coptotermes formosanus) is an important worldwide pest, each year causing millions of dollars in structural damage and control costs. Termite colonies are composed of several phenotypically distinct castes. Termites utilize these multiple castes to efficiently perform unique roles within the colony. During the molting/caste differentiation process, multiple genes are believed to be involved in the massive reorganization of the body plan. The objective of this research was to analyze the muscle gene, myosin, to further understand the role it plays in C. formosanus development. We find that comparing worker vs. solider caste myosin gene expression is up-regulated in the soldier and a myosin antibody-reactive protein suggests changes in splicing. Comparison of body regions of mature soldier and worker castes indicates a greater level of myosin transcript in the heads. The differential expression of this important muscle-related gene is anticipated considering the large amount of body plan reorganization and muscle found in the soldier caste. These results have a direct impact on our understanding of the downstream genes in the caste differentiation process and may lead to new targets for termite control.

Genome-wide expression quantitative trait loci (eQTL) analysis in maize.

BACKGROUND: Expression QTL analyses have shed light on transcriptional regulation in numerous species of plants, animals, and yeasts. These microarray-based analyses identify regulators of gene expression as either cis-acting factors that regulate proximal genes, or trans-acting factors that function through a variety of mechanisms to affect transcript abundance of unlinked genes. RESULTS: A hydroponics-based genetical genomics study in roots of a Zea mays IBM2 Syn10 double haploid population identified tens of thousands of cis-acting and trans-acting eQTL. Cases of false-positive eQTL, which results from the lack of complete genomic sequences from both parental genomes, were described. A candidate gene for a trans-acting regulatory factor was identified through positional cloning. The unexpected regulatory function of a class I glutamine amidotransferase controls the expression of an ABA 8'-hydroxylase pseudogene. CONCLUSIONS: Identification of a candidate gene underlying a trans-eQTL demonstrated the feasibility of eQTL cloning in maize and could help to understand the mechanism of gene expression regulation. Lack of complete genome sequences from both parents could cause the identification of false-positive cis- and trans-acting eQTL.

Myofibrillogenesis in skeletal muscle cells in zebrafish.

The "premyofibril" model of myofibrillogenesis, based on observations in cultured avian muscle cells, proposes that mature myofibrils are preceded by two intermediary structures: premyofibrils and nascent myofibrils. To determine if this model applies to zebrafish skeletal muscle development, we stained developing embryos with antibodies to sarcomeric alpha-actinin and myosin II. In the youngest muscle cells, sarcomeric alpha-actinin and non-muscle myosin II were each localized in linear arrays of small bands that resembled the premyofibrils in avian myocytes. The distribution of muscle-specific myosin II began as scattered short filaments followed in time by overlapping bundles of filaments and organized A-bands in the older somites. Alpha-actinin organization changed from small z-bodies to beaded Z-bands and ordered Z-bands in myofibrils that extended the length of the elongating somites. In older somites with mature myofibrils, premyofibrils were also present at the ends of the mature myofibrils, suggesting that as the cells and somites grew longer, premyofibrils were involved in the elongation of existing mature myofibrils. Fluorescence Recovery After Photobleaching showed that the exchange of proteins (actin, alpha-actinin, FATZ, myotilin and telethonin) between sarcoplasm and the Z-bands of mature myofibrils in zebrafish resembled that seen for the same proteins in cultured avian myotubes, suggesting that myofibril assembly and maintenance in zebrafish share common properties with avian muscle. Cell Motil. Cytoskeleton 2009. (c) 2009 Wiley-Liss, Inc.