Blinded Intraoperative Quantitative Indocyanine Green Metrics Associate With Intestinal Margin Acceptance in Colorectal Surgery.

BACKGROUND: Indocyanine green is a useful tool in colorectal surgery. Quantitative values may enhance and standardize its application. OBJECTIVE: To determine whether quantitative indocyanine green metrics correlate with standard subjective indocyanine green perfusion assessment in acceptance or rejection of anastomotic margins. DESIGN: Prospective single-arm, single-institution cohort study. Surgeons viewed subjective indocyanine green images but were blinded to quantitative indocyanine green metrics. SETTING: Tertiary academic center. PATIENTS: Adults undergoing planned intestinal resection. MAIN OUTCOME MEASURES: Accepted perfusion and rejected perfusion of the intestinal margin were defined by the absence or presence of ischemia by subjective indocyanine green and gross inspection. The primary outcomes included quantitative indocyanine green values, maximum fluorescence, and time-to-maximum fluorescence in accepted compared to rejected perfusion. Secondary outcomes included maximum fluorescence and time-to-maximum fluorescence values in anastomotic leak. RESULTS: There were 89 perfusion assessments comprising 156 intestinal segments. Nine segments were subjectively assessed to have poor perfusion by visual inspection and subjective indocyanine green. Maximum fluorescence (% intensity) exhibited higher intensity in accepted perfusion (accepted perfusion 161% [82%-351%] vs rejected perfusion 63% [10%-76%]; p = 0.03). Similarly, time-to-maximum fluorescence (seconds) was earlier in accepted perfusion compared to rejected perfusion (10 seconds [1-40] vs 120 seconds [90-120]; p < 0.01). Increased BMI was associated with higher maximum fluorescence. Anastomotic leak did not correlate with maximum fluorescence or time-to-maximum fluorescence. LIMITATIONS: Small cohort study, not powered to measure the association between quantitative indocyanine green metrics and anastomotic leak. CONCLUSIONS: We demonstrated that blinded quantitative values reliably correlate with subjective indocyanine green perfusion assessment. Time-to-maximum intensity is an important metric in perfusion evaluation. Quantitative indocyanine green metrics may enhance intraoperative intestinal perfusion assessment. Future studies may attempt to correlate quantitative indocyanine green values with anastomotic leak. See Video Abstract . LAS MTRICAS CUANTITATIVAS INTRAOPERATORIAS CIEGAS DEL VERDE DE INDOCIANINA SE ASOCIAN CON LA ACEPTACIN DEL MARGEN INTESTINAL EN LA CIRUGA COLORRECTAL: ANTECEDENTES:El verde de indocianina es una herramienta útil en la cirugía colorrectal. Los valores cuantitativos pueden mejorar y estandarizar su aplicación.OBJETIVO:Determinar si las métricas cuantitativas de verde de indocianina se correlacionan con la evaluación subjetiva estándar de perfusión de verde de indocianina en la aceptación o rechazo de los márgenes anastomóticos.DISEÑO:Estudio de cohorte prospectivo de un solo brazo y de una sola institución. Los cirujanos vieron imágenes subjetivas de verde de indocianina, pero no conocían las métricas cuantitativas de verde de indocianina.AJUSTE:Centro académico terciario.PACIENTES:Adultos sometidos a resección intestinal planificada.PRINCIPALES MEDIDAS DE RESULTADO:La perfusión aceptada y la perfusión rechazada del margen intestinal se definieron por la ausencia o presencia de isquemia mediante verde de indocianina subjetiva y la inspección macroscópica. Los resultados primarios fueron los valores cuantitativos de verde de indocianina, la fluorescencia máxima y el tiempo hasta la fluorescencia máxima en la perfusión aceptada en comparación con la rechazada. Los resultados secundarios incluyeron la fluorescencia máxima y el tiempo hasta alcanzar los valores máximos de fluorescencia en la fuga anastomótica.RESULTADOS:Se realizaron 89 evaluaciones de perfusión, comprendiendo 156 segmentos intestinales. Se evaluó subjetivamente que 9 segmentos tenían mala perfusión mediante inspección visual y verde de indocianina subjetiva. La fluorescencia máxima (% de intensidad) mostró una mayor intensidad en la perfusión aceptada [Perfusión aceptada 161% (82-351) vs Perfusión rechazada 63% (10-76); p = 0,03]. De manera similar, el tiempo hasta la fluorescencia máxima (segundos) fue más temprano en la perfusión aceptada en comparación con la rechazada [10 s (1-40) frente a 120 s (90-120); p < 0,01]. Aumento del índice de masa corporal asociado con una fluorescencia máxima más alta. La fuga anastomótica no se correlacionó con la fluorescencia máxima ni con el tiempo hasta la fluorescencia máxima.LIMITACIONES:Estudio de cohorte pequeño, sin poder para medir la asociación entre las mediciones cuantitativas del verde de indocianina y la fuga anastomótica.CONCLUSIÓN:Demostramos que los valores cuantitativos ciegos se correlacionan de manera confiable con la evaluación subjetiva de la perfusión de verde de indocianina. El tiempo hasta la intensidad máxima es una métrica importante en la evaluación de la perfusión. Las métricas cuantitativas de verde de indocianina pueden mejorar la evaluación de la perfusión intestinal intraoperatoria. Los estudios futuros pueden intentar correlacionar los valores cuantitativos de verde de indocianina con la fuga anastomótica. (Traducción-Dr. Yolanda Colorado).

Efficacy of Anal Sphincter Division During Fistulotomy in Anal Fissure-Associated Fistula.

BACKGROUND: A subset of chronic anal fissures beget focal infection, leading to concomitant fistula. The optimal management of fissure-associated fistula is unknown. OBJECTIVE: This study aimed to characterize healing rates and effects of fistulotomy in fissure-associated fistula. DESIGN: Retrospective study. SETTING: Urban tertiary center. PATIENTS: Adults who underwent fistulotomy for a fistula associated with a chronic anal fissure were included in the study. However, those with Crohn's disease, a history of lateral internal sphincterotomy, and a fistula not amenable to fistulotomy were excluded. INTERVENTIONS: Patients were managed with fistulotomy. Fissures were otherwise managed conservatively with a step-up approach. MAIN OUTCOME MEASURES: The primary end point was healing, defined as resolution of symptoms and both fistula and fissure wounds within 1 year. Subgroup analysis compared those who underwent subcutaneous fistulotomy (group A) with those who underwent fistulotomy involving anal sphincter fibers (group B). RESULTS: Twenty-four of 38 patients (63%) healed with a median overall follow-up of 6.6 months (4.2-14.1). The overall median time to healing was 4.4 months (2.2-6.0). No clinical or pathologic factors predicted healing. In subgroup analysis, overall subcutaneous fistulotomy healing rates were nonstatically lower at 46% (6/13) compared to fistulotomy involving anal sphincter fibers at 72% (18/25; p = 0.16). There was no difference in time to healing (subcutaneous fistulotomy, 6.7 mo [5.2-8.4] vs fistulotomy involving sphincter, 5.1 mo [2.1-7.0]; p = 0.36). LIMITATIONS: The limitations include treatment bias, with increased utilization of chemical sphincter-relaxing agents in those who did not heal. Findings are not applicable to complex fistulas, Crohn's disease, or atypical fissures. CONCLUSIONS: Patients presenting with chronic fissure and associated subcutaneous, intersphincteric, or low transphincteric fistula are successfully managed with fistulotomy. Patients with a subcutaneous fistula tract exhibited nonstatistically significantly lower rates of healing. See Video Abstract at http://links.lww.com/DCR/C145 . EFICACIA DE LA DIVISIN ESFINTRICA DURANTE LA FISTULOTOMA EN CASOS DE FSTULA ASOCIADA A FISURA ANAL: ANTECEDENTES: Ciertos subgrupos de fisuras anales crónicas ocasionan infección localizada, induciendo la aparición de una fístula anal concomitante. Se desconoce el manejo óptimo de la fístula concomitante a una fisura anal.OBJETIVO: Se trata de caracterizar las tasas de curación y el efecto de la fistulotomía en el tratamiento de la fístula concomitante a la fisura anal.DISEÑO: Estudio retrospectivo.EMPLAZAMIENTO: Centro terciario urbano.PACIENTES: Adultos sometidos a fistulotomía por una fístula concomitante a una fisura anal crónica. Se excluyeron la enfermedad de Crohn, el antecedente de una esfinterotomía lateral interna y las fístulas no susceptibles de fistulotomía.INTERVENCIONES: Los pacientes fueron manejados con una fistulotomía clasica. Por lo demás, las fisuras se trataron de forma conservadora con un enfoque médico escalonado.PRINCIPALES MEDIDAS DE RESULTADO: El criterio principal de valoración fué la cura definitiva, determinada como la resolución completa de los síntomas y de las heridas tanto de la fístula como de la fisura en el plazo de un año. El análisis de los subgrupos comparó los que se sometieron a una fistulotomía subcutánea (grupo A) versus una fistulotomía que involucró las fibras del esfínter anal interno (grupo B).RESULTADOS: 24/38 pacientes (63%) curaron con una mediana de seguimiento global de 6,6 meses (4,2-14,1). El tiempo medio general de curación fue de 4,4 meses (2,2-6,0). Ningún factor clínico o patológico predijo la cura. En el análisis de subgrupos, las tasas generales de cura de la fistulotomía subcutánea no fueron estadísticamente más bajas de 46 % (6/13) comparados con la fistulotomía que involucró las fibras del esfínter anal interno en 72 % (18/25; p = 0,16). No hubo diferencia en el tiempo de cicatrización [fistulotomía subcutánea 6,7 meses (5,2-8,4) conparada a la fistulotomía y esfínterotomía parcial interna a 5,1 meses (2,1-7,0); p = 0,36].LIMITACIONES: Sesgo del tratamiento, con mayor utilización de agentes químicos relajantes de la musculatura esfínteriana en aquellos pacientes que no sanaron. No aplicable a fístulas complejas, enfermedad de Crohn o fisuras atípicas.CONCLUSIÓNES: Los pacientes que presentan fisura crónica y fístula subcutánea, inter-esfintérica o trans-esfintérica baja concomitante se manejan con éxito con una fistulotomía. Los pacientes con un trayecto de fístula subcutánea exhibieron tasas de curación más bajas y no estadísticamente significativas. Consulte Video Resumen en http://links.lww.com/DCR/C145 . (Traducción-Dr. Xavier Delgadillo ).

Preoperative CT Indices Predict Nonreach Before IPAA.

BACKGROUND: IPAA aims to restore continence to patients after total proctocolectomy. However, some patients have inadequate small-bowel mesenteric length to achieve reconstruction. No preoperative risk stratification tools of native anatomy exist. OBJECTIVE: We report CT-guided measurements of anatomic landmarks to predict nonreach before IPAA. DESIGN: This is a single-institution retrospective analysis of a prospective database. SETTING: This study was conducted at Cedars-Sinai between January 2007 and December 2021. PATIENTS: Patients with IBD undergoing a 2- or 3-stage IPAA with a preoperative abdominal CT using either an enterography protocol or IV contrast sufficient to visualize mesenteric vasculature were included in the study. CT mesenteric indices were assessed, including total length (representing length required for the pouch to reach the anal canal), mesenteric length (inherent length of small-bowel mesentery), and mobilization length (the difference between total length and mesenteric length). MAIN OUTCOME MEASURES: The primary outcome was IPAA nonreach. The secondary outcomes were association of clinical variables and CT mesenteric indices. RESULTS: Six of 59 patients (10%) experienced nonreach. Mobilization length was longer in the nonreach group by 5.8 cm ( p = 0.01), and mesenteric length was shorter by 3.5 cm ( p = 0.04). Mobilization length ≥17 cm provided 100% sensitivity and 69% specificity (OR 1.46, area under the curve 0.84, p = 0.004) for nonreach. Similarly, a mesenteric length <14.6 cm demonstrated 100% sensitivity and 49% specificity for IPAA nonreach (area under the curve 0.75, p = 0.03). LIMITATIONS: The retrospective nature of the study precluded a standardized imaging protocol. External validation will be required because of the small sample size. CONCLUSIONS: CT-based measurements of length, specifically mesenteric and mobilization length, predict nonreach before IPAA. This method is noninvasive, readily available, and may be useful for preoperative patient counseling and operative planning. See Video Abstract at http://links.lww.com/DCR/C140 . LOS NDICES DE TOMOGRAFA COMPUTARIZADA PREOPERATORIA PREDICEN LA AUSENCIA DE ALCANCE ANTES DE LA ANASTOMOSIS DEL RESERVORIO ILEALANAL: ANTECEDENTES:La anastomosis del reservorio ileoanal tiene como objetivo restaurar la continencia en los pacientes después de una proctocolectomía total. Sin embargo, algunos pacientes tienen una longitud mesentérica del intestino delgado inadecuada para lograr la reconstrucción. No existen herramientas de estratificación del riesgo preoperatorio de la anatomía nativa.OBJETIVO:Informamos mediciones guiadas por tomografía computarizada de puntos de referencia anatómicos para predecir la falta de alcance antes de la anastomosis ileoanal con reservorio.DISEÑO:Este es un análisis retrospectivo de una sola institución de una base de datos prospectiva.AJUSTE:Este estudio se realizó en Cedars-Sinai entre Enero de 2007 y Diciembre de 2021.PACIENTES:Pacientes con enfermedad inflamatoria intestinal que se someten a una anastomosis anal con reservorio ileal en 2 o 3 etapas con una tomografía computarizada abdominal preoperatoria utilizando un protocolo de enterografía o contraste intravenoso suficiente para visualizar la vasculatura mesentérica. Se evaluaron los índices mesentéricos de tomografía computarizada, incluida la longitud total (que representa la longitud requerida para que la bolsa alcance el canal anal), la longitud mesentérica (longitud inherente del mesenterio del intestino delgado) y la longitud de movilización (la diferencia entre la longitud total y la longitud mesentérica).PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue falta de alcance de la anastomosis del reservorio ileoanal. Los resultados secundarios fueron la asociación de variables clínicas y los índices mesentéricos de tomografía computarizada.RESULTADOS:Seis de 59 (10%) pacientes experimentaron falta de alcance. La longitud de movilización fue mayor en el grupo sin alcance en 5,8 cm ( p = 0,01) y la longitud mesentérica fue menor en 3,5 cm ( p = 0,04). La longitud de movilización ≥17 cm proporcionó una sensibilidad del 100% y una especificidad del 69% (OR 1,46, AUC 0,84, p = 0,004) para la falta de alcance. De manera similar, una longitud mesentérica <14,6 cm demostró una sensibilidad del 100% y una especificidad del 49% para la falta de alcance de la anastomosis del reservorio ileoanal (AUC 0,75, p = 0,03).LIMITACIONES:La naturaleza retrospectiva del estudio impidió un protocolo de imágenes estandarizado. Se requerirá una validación externa debido al pequeño tamaño de la muestra.CONCLUSIONES:Las mediciones de longitud basadas en tomografía computarizada, específicamente la longitud mesentérica y de movilización, predicen la falta de alcance antes de la anastomosis anal con bolsa ileo. Este método no es invasivo, está fácilmente disponible y puede ser útil para el asesoramiento preoperatorio del paciente y la planificación quirúrgica. Consulte el Video Resumen en https://links.lww.com/DCR/C140 . (Traducción-Dr. Yesenia Rojas-Khalil ).

Ensuring Indigenous co-leadership in health research: a Can-SOLVE CKD case example.

BACKGROUND: Indigenous people are insightful and informed about their own health and wellness, yet their visions, strengths and knowledge are rarely incorporated into health research. This can lead to subpar engagement or irrelevant research practices, which exacerbates the existing health inequities Indigenous people experience compared to the non-Indigenous population. Data consistently underscores the importance of Indigenous self-determination in research as a means to address health inequities. However, there are few formal methods to support this goal within the existing research context, which is dominated by Western perspectives. MAIN TEXT: Canadians Seeking Solutions and Innovations to Overcome Chronic Kidney Disease (Can-SOLVE CKD) is a patient-oriented research network in Canada that recognizes the need to create the space to facilitate Indigenous self-determination in research. Indigenous members of the network therefore created and evolved a unique group, called the Indigenous Peoples' Engagement and Research Council (IPERC). IPERC plays a critical role in informing Can-SOLVE CKD research priorities, as well as creating tools to support Indigenous-specific research and engagement. This approach ensures that Indigenous voices and knowledge are critical threads within the fabric of the network's operations and research projects. Here, we describe the methods taken to create a council such as IPERC, and provide examples of initiatives by the council that aim to increase Indigenous representation, participation and partnership in research. We share lessons learned on what factors contribute to the success of IPERC, which could be valuable for other organizations interested in creating Indigenous-led research councils. CONCLUSION: Indigenous self-determination in research is critical for addressing health inequities. Here, we present a unique model, led by a council of diverse Indigenous people, which could help reduce health equities and lead to a better era of research for everyone.

Distribution and trends of mercury in aquatic and terrestrial biota of New York, USA: a synthesis of 50 years of research and monitoring.

Mercury (Hg) inputs have particularly impacted the northeastern United States due to its proximity to anthropogenic emissions sources and abundant habitats that efficiently convert inorganic Hg into methylmercury. Intensive research and monitoring efforts over the past 50 years in New York State, USA, have informed the assessment of the extent and impacts of Hg exposure on fishes and wildlife. By synthesizing Hg data statewide, this study quantified temporal trends of Hg exposure, spatiotemporal patterns of risk, the role that habitat and Hg deposition play in producing spatial patterns of Hg exposure in fish and other wildlife, and the effectiveness of current monitoring approaches in describing Hg trends. Most temporal trends were stable, but we found significant declines in Hg exposure over time in some long-sampled fish. The Adirondack Mountains and Long Island showed the greatest number of aquatic and terrestrial species with elevated Hg concentrations, reflecting an unequal distribution of exposure risk to fauna across the state. Persistent hotspots were detected for aquatic species in central New York and the Adirondack Mountains. Elevated Hg concentrations were associated with open water, forests, and rural, developed habitats for aquatic species, and open water and forested habitats for terrestrial species. Areas of consistently elevated Hg were found in areas driven by atmospheric and local Hg inputs, and habitat played a significant role in translating those inputs into biotic exposure. Continued long-term monitoring will be important in evaluating how these patterns continue to change in the face of changing land cover, climate, and Hg emissions.

Mercury in Neotropical birds: a synthesis and prospectus on 13 years of exposure data.

Environmental mercury (Hg) contamination of the global tropics outpaces our understanding of its consequences for biodiversity. Knowledge gaps of pollution exposure could obscure conservation threats in the Neotropics: a region that supports over half of the world's species, but faces ongoing land-use change and Hg emission via artisanal and small-scale gold mining (ASGM). Due to their global distribution and sensitivity to pollution, birds provide a valuable opportunity as bioindicators to assess how accelerating Hg emissions impact an ecosystem's ability to support biodiversity, and ultimately, global health. We present the largest database on Neotropical bird Hg concentrations (n = 2316) and establish exposure baselines for 322 bird species spanning nine countries across Central America, South America, and the West Indies. Patterns of avian Hg exposure in the Neotropics broadly align with those in temperate regions: consistent bioaccumulation across functional groups and high spatiotemporal variation. Bird species occupying higher trophic positions and aquatic habitats exhibited elevated Hg concentrations that have been previously associated with reductions in reproductive success. Notably, bird Hg concentrations were over four times higher at sites impacted by ASGM activities and differed by season for certain trophic niches. We developed this synthesis via a collaborative research network, the Tropical Research for Avian Conservation and Ecotoxicology (TRACE) Initiative, which exemplifies inclusive, equitable, and international data-sharing. While our findings signal an urgent need to assess sampling biases, mechanisms, and consequences of Hg exposure to tropical avian communities, the TRACE Initiative provides a meaningful framework to achieve such goals. Ultimately, our collective efforts support and inform local, scientific, and government entities, including Parties of the United Nations Minamata Convention on Mercury, as we continue working together to understand how Hg pollution impacts biodiversity conservation, ecosystem function, and public health in the tropics.

RESúMEN: La contaminación ambiental por mercurio (Hg) en los trópicos supera nuestra comprensión de sus consecuencias para la biodiversidad. Los vacíos de conocimiento que existen sobre la exposición a la contaminación podrían ocultar las amenazas para la conservación en el Neotrópico: una región que alberga a más de la mitad de las especies del mundo, pero que enfrenta una continua intensificación de las emisiones de Hg y del cambio de uso del suelo por el avance de la minería de oro artesanal y de pequeña escala (MAPE). Debido a su distribución global y su sensibilidad a la contaminación, las aves brindan una oportunidad valiosa como bioindicadores para evaluar cómo las emisiones de Hg afectan la capacidad de un ecosistema para sustentar la biodiversidad y, en última instancia, la salud global. Presentamos la más grande base de datos sobre concentraciones de Hg en aves Neotropicales (n = 2,316) para establecer una línea base para los niveles de exposición a Hg en 322 especies de aves de nueve países de América Central, América del Sur, y el Caribe. Encontramos patrones de las concentraciones de Hg en aves de los trópicos que se asemejan a los de las regiones templadas: mostrando una bioacumulación consistente a través de grupos funcionales y una alta variación espaciotemporal. Las especies de aves que ocupan posiciones más altas en la cadena trófica y en hábitats acuáticos registraron concentraciones elevadas de Hg que podrían tener efectos negativos en su éxito reproductivo. Es importante resaltar que las concentraciones de Hg en las aves de los sitios afectados por la MAPE fueron cuatro veces más altas que las de los sitios control y además difirió por temporada para ciertos nichos tróficos. Desarrollamos esta síntesis a través de una red de investigación colaborativa, la Iniciativa de Investigación Tropical para la Conservación y Ecotoxicología Aviar (TRACE), que ejemplifica un intercambio de datos inclusivo, equitativo e internacional. Si bien nuestros hallazgos sugieren una necesidad urgente de evaluar los sesgos en el muestreo, los mecanismos, y las consecuencias de la exposición al Hg en las comunidades de aves tropicales, la Iniciativa TRACE proporciona un marco para abordar estos objetivos. Nuestro esfuerzo colectivo tiene como propósito respaldar y brindar información a las entidades locales, científicas, y gubernamentales, incluyendo las Partes de la Convención de Minamata de las Naciones Unidas sobre el Mercurio, mientras continuamos trabajando juntos para comprender cómo la contaminación por Hg en los trópicos puede afectar la salud pública, el funcionamiento de los ecosistemas, y la conservación de la biodiversidad. Total mercury (THg) concentrations (µg/g) and sample sizes of birds across Central America, South America, and the West Indies from 2007­2023. Point size and color are arranged in order of increasing THg concentration and hexagonal grid cells are colored in terms of increasing sample size.

Mercury exposure in migrating songbirds: correlations with physical condition.

Many migratory songbirds are at high risk of methylmercury (MeHg) exposure due to their trophic position and foraging in and around wetland habitats. Methylmercury has the potential to alter migratory behaviors and physiology via neurological impairment or reduced flight performance and can be remobilized from songbird muscle tissue during migration, increasing the risk of acute MeHg exposure. To document MeHg exposure and its relationship with physical condition in migratory songbirds, we sampled passerine blood and feathers at a migration stopover site on Key Biscayne, FL during fall and spring from 2009 to 2012. We found evidence that spring blood total mercury (THg) concentrations decreased throughout the day and that fall feather THg concentrations changed over the migratory season. Total mercury exposure was marginally correlated with migratory fat stores and related to changes in pectoral muscle thickness by time of day. These patterns suggest that environmentally relevant levels of THg are related to, and may be influencing, the physical condition of free-living migrating songbirds. Further research and monitoring during the migratory period will be important to elucidate exposure risk across multiple species and assess the potential for effects during this complex period of the annual cycle.

Mercury exposure in songbird communities along an elevational gradient on Whiteface Mountain, Adirondack Park (New York, USA).

Mercury (Hg) is a potent neurotoxin that biomagnifies within food webs. Adverse effects have been documented for avian species related to exposure of elevated Hg levels. High elevation, boreal forests generally receive higher atmospheric Hg deposition and regional studies have subsequently identified elevated blood Hg concentrations in songbird species inhabiting these montane habitats. The overall goal of this study was to investigate spatial and seasonal Hg exposure patterns in songbird species along an elevational gradient on Whiteface Mountain in the Adirondack Park of New York State. Songbird blood samples were collected from June-July in 2009 and 2010 along an elevational gradient at 13 study plots (450-1400 m) with a focus on Catharus thrushes, including the hermit thrush, Swainson's thrush, and Bicknell's thrush. The main results of this study documented: (1) an overall linear pattern of increasing blood Hg concentrations with increasing elevation, with additional analysis suggesting a nonlinear elevational pattern of increasing blood Hg concentrations to 1075 m, followed by decreasing concentrations thereafter, for all Catharus thrush species across the elevational gradient; and (2) an overall nonlinear seasonal pattern of increasing, followed by decreasing blood Hg concentrations across target species. Avian exposure patterns appear driven by elevated atmospheric Hg deposition and increased methylmercury bioavailability within high elevation habitats as compared with low elevation forests. Seasonal patterns are likely influenced by a combination of complex and dynamic variables related to dietary selection and annual molting cycles. Considering that few high elevation analyses have been conducted within the context of regional songbird research, this project complements the results from similar studies and highlights the need for further monitoring efforts to investigate environmental Hg contamination within avian communities.

Mercury exposure in songbird communities within Sphagnum bog and upland forest ecosystems in the Adirondack Park (New York, USA).

Mercury (Hg) is a potent neurotoxin that biomagnifies within both aquatic and terrestrial food webs resulting in adverse physiological and reproductive effects on impacted wildlife populations, including songbird communities. Due to reducing conditions, wetland ecosystems promote the formation of methylmercury. Regional studies have documented elevated blood mercury concentrations in songbird species within these habitat types. The overall goal of this research was to examine spatial and seasonal patterns of Hg exposure for targeted songbird species within Sphagnum bog wetland systems and compare these patterns with adjacent upland forests in the Adirondack Park of New York State. Project sampling was conducted at study plots within four Sphagnum bog and associated upland forest sites from May - August during the 2008, 2009, and 2011 field seasons. The overall results documented: (1) blood Hg concentrations were elevated in songbird species inhabiting Sphagnum bog habitats as compared to nearby upland forest species; (2) target species within each habitat type exhibited consistent species-level patterns in blood Hg concentrations at each study site; and (3) no seasonal change in blood Hg concentrations within Sphagnum bog habitats was documented, but an increasing, followed by a decreasing seasonal pattern in mercury exposure was detected for upland forest species. Habitat type was demonstrated to influence avian Hg exposure levels. Moreover, Sphagnum bog ecosystems may be contributing to elevated Hg concentrations in biota within the surrounding environment. Seasonal patterns for blood Hg concentrations were found to vary between habitat type and are likely related to a combination of variables including habitat-driven Hg concentrations in prey items, seasonal dietary shifts, and annual molting cycles. This project emphasizes the importance of prioritizing future research efforts within identified high Hg habitat types, specifically wetland systems, to better characterize associated avian exposure levels, estimate the spatial extent of wetland systems on the surrounding environment, and identify locations of potential biological hotspots across the Adirondack Park.

The effects of climate, habitat, and trophic position on methylmercury bioavailability for breeding New York songbirds.

Mercury (Hg) is a global pollutant that affects songbird populations across a variety of ecosystems following conversion to methylmercury (MeHg)-a form of Hg with high potential for bioaccumulation and bioavailability. The amount of bioavailable MeHg in an ecosystem is a function of the amount of total Hg present as well as Hg methylation rates, which vary across the landscape in space and time, and trophic transfer. Using songbirds as an indicator of MeHg bioavailability in terrestrial ecosystems, we evaluated the role of habitat, climate, and trophic level in dictating MeHg exposure risk across a variety of ecosystems. To achieve this objective, 2243 blood Hg samples were collected from 81 passerine and near-passerine species in New York State, USA, spanning 10 different sampling regions from Long Island to western New York. Using a general linear mixed modeling framework that accounted for regional variation in sampling species composition, we found that wetland habitat area within 100 m of capture location, 50-year average of summer maximum temperatures, and trophic position inferred using stable isotope analysis were all correlated with songbird blood Hg concentrations statewide. Moreover, these patterns had a large degree of spatial variability suggesting that the drivers of MeHg bioavailability differed significantly across the state. Mercury deposition, land cover, and climate are all expected to change throughout the northeastern United States in the coming decades. Terrestrial MeHg bioavailability will likely respond to these changes. Focused research and monitoring efforts will be critical to understand how exposure risk responds to global environmental change across the landscape.

Long-term monitoring of mercury in adult saltmarsh sparrows breeding in Maine, Massachusetts and New York, USA 2000-2017.

Here we report on the results of a long-term study of mercury exposure in a songbird species, the saltmarsh sparrow (Ammodramus caudacutus). We measured total mercury concentrations in blood (n = 840) and feathers (n = 560) of adult saltmarsh sparrows at six locations between 2000 and 2017: Rachel Carson National Wildlife Refuge (RCNWR) in Wells, Maine; Scarborough Marsh State Wildlife Management Area in Scarborough, Maine; Parker River National Wildlife Refuge on Plum Island, Massachusetts; Pine Neck Preserve in Southampton, Long Island, New York; and North Cinder and North Green Sedge Islands off the coast of Long Island, New York. During the 12-17 year sampling periods, we found that mercury exposure differed by site and year but there was no consistent temporal trend across sites. Blood mercury concentrations declined only at RCNWR in Maine. We also found seasonal variation in blood mercury concentrations and a positive relationship between mercury concentrations of blood and innermost primary feather, but not between blood and tail feather.

Ultraviolet-assisted oiling assessment improves detection of oiled birds experiencing clinical signs of hemolytic anemia after exposure to the Deepwater Horizon oil spill.

While large-scale oil spills can cause acute mortality events in birds, there is increasing evidence that sublethal oil exposure can trigger physiological changes that have implications for individual performance and survival. Therefore, improved methods for identifying small amounts of oil on birds are needed. Because ultraviolet (UV) light can be used to identify thin crude oil films in water and on substrate that are not visually apparent under normal lighting conditions, we hypothesized that UV light could be useful for detecting small amounts of oil present on the plumage of birds. We evaluated black skimmers (Rynchops niger), brown pelicans (Pelecanus occidentalis), clapper rails (Rallus crepitans), great egrets (Ardea alba), and seaside sparrows (Ammodramus maritimus) exposed to areas affected by the Deepwater Horizon oil spill in the Gulf of Mexico as well as from reference areas from 20 June, 2010 to 23 February, 2011. When visually assessed without UV light, 19.6% of birds evaluated from areas affected by the spill were determined to be oiled (previously published data), whereas when examined under UV light, 56.3% of the same birds were determined to have oil exposure. Of 705 individuals examined in areas potentially impacted by the spill, we found that fluorescence under UV light assessment identified 259 oiled birds that appeared to be oil-free on visual exam, supporting its utility as a simple tool for improving detection of modestly oiled birds in the field. Further, UV assessment revealed an increase in qualitative severity of oiling (approximate % of body surface oiled) in 40% of birds compared to what was determined on visual exam. Additionally, black skimmers, brown pelicans, and great egrets exposed to oil as determined using UV light experienced oxidative injury to erythrocytes, had decreased numbers of circulating erythrocytes, and showed evidence of a regenerative hematological response in the form of increased reticulocytes. This evidence of adverse effects was similar to changes identified in birds with oil exposure as determined by visual examination without UV light, and is consistent with hemolytic anemia likely caused by oil exposure. Thus, UV assessment proved useful for enhancing detection of birds exposed to oil, but did not increase detection of birds experiencing clinical signs of anemia compared to standard visual oiling assessment. We conclude that UV light evaluation can help identify oil exposure in many birds that would otherwise be identified visually as unexposed during oil spill events.

Historical patterns in mercury exposure for North American songbirds.

Methylmercury (MeHg) is a global environmental contaminant that poses significant risks to the health of humans, wildlife, and ecosystems. Assessing MeHg exposure in biota across the landscape and over time is vital for monitoring MeHg pollution and gauging the effectiveness of regulations intended to reduce new mercury (Hg) releases. We used MeHg concentrations measured in museum specimen feathers (collected between 1869 and 2014) and total Hg concentrations (as a proxy for MeHg) of feathers sampled from wild birds (collected between 2008 and 2017) to investigate temporal patterns in exposure over approximately 150 years for North American songbirds. For individual species, we found greater concentrations for samples collected post-2000 compared to those collected during historic times (pre-1900) for six of seven songbird species. Mean feather concentrations measured in samples collected post-2000 ranged between 1.9 and 17 times (mean 6.6) greater than historic specimens. The proportion of individual songbirds with feather concentrations that exceeded modeled toxicity benchmarks increased in samples collected after 1940. Only 2% of individual songbirds collected prior to 1940 had feather concentrations greater than 2.4 µg/g (a toxicity benchmark related to a 10% decrease in nest success) compared to 35% of individuals collected post-1940. Many species included in this study have a vulnerable or near-threatened conservation status, suggesting recovery actions are needed to address mercury pollution.

Engagement in Maximally-Assisted Therapy and Adherence to Antiretroviral Therapy Among a Cohort of Indigenous People Who Use Illicit Drugs.

Throughout the world, Indigenous populations experience a disproportionate burden of HIV infection. Maximally-assisted therapy (MAT) is an interdisciplinary care intervention that includes ART dispensation to support individuals with a history of addiction and homelessness. This study sought to longitudinally evaluate the relationship between engagement in MAT and achieving optimal adherence using data from an ongoing cohort of HIV-positive individuals who use drugs in Vancouver, Canada, where HIV/AIDS treatment is offered at no cost. Between December 2005 and November 2016, 354 HIV-positive Indigenous participants were enrolled and data were analyzed using generalized mixed-effects (GLMM) and marginal structural modeling. In both multivariable analyses, engagement in MAT was independently associated with optimal adherence to ART (GLMM: AOR = 4.92, 95% CI 3.18-7.62; marginal structural model: AOR = 5.76, 95% CI 3.34-9.96). MAT-based programmes could be a part of a renewed evidence-base to elevated levels of preventable HIV/AIDS-associated morbidity, mortality and viral transmission among Indigenous peoples in Canada.

Prognostic utility of MELD-XI in adult congenital heart disease patients undergoing cardiac transplantation.

BACKGROUND: Model of End-Stage Liver Disease eXcluding INR (MELD-XI) at cardiac transplant has demonstrated prognostic survival utility, but has not been specifically validated in adult congenital heart disease (ACHD) in a registry study. METHODS: Adults undergoing first-time orthotopic heart transplant from 2005 to 2015 in the United Network for Organ Sharing (UNOS) registry were examined in parallel: ACHD (n = 543), ischemic-dilated cardiomyopathy (IDCM, n = 6954) and valvular heart disease (VHD, n = 355). Our primary endpoint was a composite of death, graft failure, and retransplantation assessed at 3 months (early), and those with freedom from early endpoint were reassessed at 5 years (late). Interactions between hepatorenal indices and waitlist time were examined. Secondary outcomes relating to long-term morbidity were assessed at late endpoint. Freedom from endpoint analysis in ACHD at clinically relevant endpoints was also conducted. RESULTS: Model of End-Stage Liver Disease eXcluding INR score at transplant associated with an increased risk of early endpoint in all cohorts. At late endpoint, bilirubin level associated with increased risk uniquely in ACHD. CONCLUSIONS: Model of End-Stage Liver Disease eXcluding INR holds prognostic application to ACHD in early time points and demonstrates unique waitlist interactions. Transplant bilirubin level may hold significance in long-term risk stratification of the ACHD population. Time on waitlist is an important consideration to contextualize these values.

Single-locus enrichment without amplification for sequencing and direct detection of epigenetic modifications.

A gene-level targeted enrichment method for direct detection of epigenetic modifications is described. The approach is demonstrated on the CGG-repeat region of the FMR1 gene, for which large repeat expansions, hitherto refractory to sequencing, are known to cause fragile X syndrome. In addition to achieving a single-locus enrichment of nearly 700,000-fold, the elimination of all amplification steps removes PCR-induced bias in the repeat count and preserves the native epigenetic modifications of the DNA. In conjunction with the single-molecule real-time sequencing approach, this enrichment method enables direct readout of the methylation status and the CGG repeat number of the FMR1 allele(s) for a clonally derived cell line. The current method avoids potential biases introduced through chemical modification and/or amplification methods for indirect detection of CpG methylation events.

Songbirds as sentinels of mercury in terrestrial habitats of eastern North America.

Mercury (Hg) is a globally distributed environmental contaminant with a variety of deleterious effects in fish, wildlife, and humans. Breeding songbirds may be useful sentinels for Hg across diverse habitats because they can be effectively sampled, have well-defined and small territories, and can integrate pollutant exposure over time and space. We analyzed blood total Hg concentrations from 8,446 individuals of 102 species of songbirds, sampled on their breeding territories across 161 sites in eastern North America [geometric mean Hg concentration = 0.25 µg/g wet weight (ww), range <0.01-14.60 µg/g ww]. Our records span an important time period-the decade leading up to implementation of the USEPA Mercury and Air Toxics Standards, which will reduce Hg emissions from coal-fired power plants by over 90 %. Mixed-effects modeling indicated that habitat, foraging guild, and age were important predictors of blood Hg concentrations across species and sites. Blood Hg concentrations in adult invertebrate-eating songbirds were consistently higher in wetland habitats (freshwater or estuarine) than upland forests. Generally, adults exhibited higher blood Hg concentrations than juveniles within each habitat type. We used model results to examine species-specific differences in blood Hg concentrations during this time period, identifying potential Hg sentinels in each region and habitat type. Our results present the most comprehensive assessment of blood Hg concentrations in eastern songbirds to date, and thereby provide a valuable framework for designing and evaluating risk assessment schemes using sentinel songbird species in the time after implementation of the new atmospheric Hg standards.

Mercury in bats from the northeastern United States.

This study examines mercury exposure in bats across the northeast U.S. from 2005 to 2009. We collected 1,481 fur and 681 blood samples from 8 states and analyzed them for total Hg. A subset (n = 20) are also analyzed for methylmercury (MeHg). Ten species of bats from the northeast U.S. are represented in this study of which two are protected by the Endangered Species Act (ESA 1973) and two other species are pending review. There are four objectives in this paper: (1) to examine correlates to differences in fur-Hg levels among all of the sampling sites, including age, sex, species, and presence of a Hg point source; (2) define the relationship between blood and fur-Hg levels and the factors that influence that relationship including age, sex, species, reproductive status, and energetic condition; (3) determine the relationships between total Hg and MeHg in five common eastern bat species; and (4) assess the distribution of Hg across bat populations in the northeast. We found total blood and fur mercury was eight times higher in bats captured near point sources compared to nonpoint sources. Blood-Hg and fur-Hg were well correlated with females on average accumulating two times more Hg in fur than males. On average fur MeHg accounted for 86 % (range 71-95 %) of the total Hg in bat fur. Considering that females had high Hg concentrations, beyond that of established levels of concern, suggests there could be negative implications for bat populations from high Hg exposure since Hg is readily transferred to pups via breast milk. Bats provide an integral part of the ecosystem and their protection is considered to be of high priority. More research is needed to determine if Hg is a stressor that is negatively impacting bat populations.

Surface and subsurface oceanographic features drive forage fish distributions and aggregations: Implications for prey availability to top predators in the US Northeast Shelf ecosystem.

Forage fishes are a critical food web link in marine ecosystems, aggregating in a hierarchical patch structure over multiple spatial and temporal scales. Surface-level forage fish aggregations (FFAs) represent a concentrated source of prey available to surface- and shallow-foraging marine predators. Existing survey and analysis methods are often imperfect for studying forage fishes at scales appropriate to foraging predators, making it difficult to quantify predator-prey interactions. In many cases, general distributions of forage fish species are known; however, these may not represent surface-level prey availability to predators. Likewise, we lack an understanding of the oceanographic drivers of spatial patterns of prey aggregation and availability or forage fish community patterns. Specifically, we applied Bayesian joint species distribution models to bottom trawl survey data to assess species- and community-level forage fish distribution patterns across the US Northeast Continental Shelf (NES) ecosystem. Aerial digital surveys gathered data on surface FFAs at two project sites within the NES, which we used in a spatially explicit hierarchical Bayesian model to estimate the abundance and size of surface FFAs. We used these models to examine the oceanographic drivers of forage fish distributions and aggregations. Our results suggest that, in the NES, regions of high community species richness are spatially consistent with regions of high surface FFA abundance. Bathymetric depth drove both patterns, while subsurface features, such as mixed layer depth, primarily influenced aggregation behavior and surface features, such as sea surface temperature, sub-mesoscale eddies, and fronts influenced forage fish diversity. In combination, these models help quantify the availability of forage fishes to marine predators and represent a novel application of spatial models to aerial digital survey data.