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1.
Conserv Biol ; 37(5): e14091, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37021393

RESUMO

Understanding how habitat fragmentation affects individual species is complicated by challenges associated with quantifying species-specific habitat and spatial variability in fragmentation effects within a species' range. We aggregated a 29-year breeding survey data set for the endangered marbled murrelet (Brachyramphus marmoratus) from >42,000 forest sites throughout the Pacific Northwest (Oregon, Washington, and northern California) of the United States. We built a species distribution model (SDM) in which occupied sites were linked with Landsat imagery to quantify murrelet-specific habitat and then used occupancy models to test the hypotheses that fragmentation negatively affects murrelet breeding distribution and that these effects are amplified with distance from the marine foraging habitat toward the edge of the species' nesting range. Murrelet habitat declined in the Pacific Northwest by 20% since 1988, whereas the proportion of habitat comprising edges increased by 17%, indicating increased fragmentation. Furthermore, fragmentation of murrelet habitat at landscape scales (within 2 km of survey stations) negatively affected occupancy of potential breeding sites, and these effects were amplified near the range edge. On the coast, the odds of occupancy decreased by 37% (95% confidence interval [CI] -54 to 12) for each 10% increase in edge habitat (i.e., fragmentation), but at the range edge (88 km inland) these odds decreased by 99% (95% CI 98 to 99). Conversely, odds of murrelet occupancy increased by 31% (95% CI 14 to 52) for each 10% increase in local edge habitat (within 100 m of survey stations). Avoidance of fragmentation at broad scales but use of locally fragmented habitat with reduced quality may help explain the lack of murrelet population recovery. Further, our results emphasize that fragmentation effects can be nuanced, scale dependent, and geographically variable. Awareness of these nuances is critical for developing landscape-level conservation strategies for species experiencing broad-scale habitat loss and fragmentation.


Efectos de la fragmentación sobre las especies en peligro a lo largo de un gradiente desde el interior hasta el borde de su distribución Resumen Es complicado entender el efecto de la fragmentación del hábitat sobre las especies individuales debido a los retos asociados con la cuantificación de hábitats específicos por especie y la variabilidad espacial de los efectos de la fragmentación dentro de la distribución de la especie. Combinamos los datos de un censo reproductivo realizado durante 29 años para el mérgulo jaspeado (Brachyramphus marmoratus) de >42,000 sitios boscosos a lo largo del noroeste del Pacífico (Oregón, Washington, y el norte de California, EE. UU.). Construimos un modelo de distribución de especie (MDE) en el cual los sitios ocupados estuvieron vinculados con imágenes de Landsat para cuantificar el hábitat específico del mérgulo y después usamos los modelos de ocupación para comprobar la hipótesis de que la fragmentación afecta negativamente la distribución reproductiva de la especie y que estos efectos se amplifican con la distancia entre el hábitat de forrajeo marino y el borde de la distribución de anidación de la especie. El hábitat del mérgulo declinó en la zona en un 20% a partir de 1988, mientras que la proporción de hábitat que comprende bordes incrementó en un 17%, lo que indica un aumento en la fragmentación. Además, la fragmentación del hábitat del mérgulo a escala de paisaje (a de 2 km de las estaciones de censo) afectó negativamente a la ocupación de sitios potenciales de reproducción y estos efectos se amplificaron cerca del borde de la distribución. La probabilidad de ocupación disminuyó en un 37% (95% IC -54 a 12) por cada 10% de incremento en el hábitat de borde (es decir, fragmentación) en la costa, pero en el borde de la distribución (88 km tierra adentro), esta probabilidad disminuyó en un 99% (95% IC 98 a 99). De forma contraria, la probabilidad de ocupación incrementó en un 31% (95% IC 14 a 52) por cada 10% de incremento en el hábitat de borde local (a 100 m de las estaciones de censo). La evasión de la fragmentación a gran escala y el uso de hábitats con calidad reducida y fragmentados a nivel local podría explicar la falta de recuperación poblacional del mérgulo. Más allá, nuestros resultados resaltan que los efectos de la fragmentación pueden estar matizados, depender de la escala y tener variación geográfica. Es importante tener conciencia de estos matices para desarrollar estrategias de conservación a nivel paisaje para las especies que experimentan fragmentación y pérdida del hábitat a gran escala.


Assuntos
Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Animais , Ecossistema , Florestas , Washington
2.
Mod Pathol ; 32(4): 560-567, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30425334

RESUMO

Amphiregulin, a weak epidermal growth factor receptor agonist, is elevated, while epidermal growth factor, a strong epidermal growth factor receptor agonist, is low in the blood of patients with severe acute graft-versus-host disease. However, the tissue expression and function of these epidermal growth factor receptor ligands in acute graft-versus-host disease target organs is unknown. We compared by immunohistochemistry expression of amphiregulin and epidermal growth factor in archived, formalin-fixed, paraffin-embedded intestinal tissues of 48 patients with biopsy-proven gastrointestinal acute graft-versus-host disease to 3 groups: (1) 10 non-hematopoietic cell transplant normal controls, (2) 11 patients with newly diagnosed ulcerative colitis (ulcerative colitis), (3) 8 patients with a clinical diagnosis of acute graft-versus-host disease despite pathologically non-diagnostic biopsies, (4) and 10 cases of cytomegalovirus colitis. We used a semi-quantitative score of 0 (absent) through 3 (strong) to describe the intensity of immunohistochemical staining. We correlated serum and tissue amphiregulin and epidermal growth factor in patients with acute graft-versus-host disease. Gastrointestinal amphiregulin was significantly lower in acute graft-versus-host disease biopsies (median score 1), ulcerative colitis (median score 1.5), and cytomegalovirus colitis (median score 1) than in normal colon (median score 2, p = 0.004, p = 0.03, p = 0.009 respectively). Amphiregulin expression in was low in 74% of acute graft-versus-host disease cases with or without significant apoptosis. Patients with acute graft-versus-host disease exhibiting the pattern of high gastrointestinal amphiregulin but low serum amphiregulin (n = 14) had the best 1-year survival at 71%, but patients with high serum amphiregulin had poorer survival (<30%) regardless of gastrointestinal amphiregulin expression. Overall, our results lead to the hypothesis that amphiregulin is released into the circulation from damaged intestinal epithelium and stroma, although contributions from other cellular sources are likely. Low gastrointestinal amphiregulin expression by immunohistochemistry may be further studied for its utility in the pathologic acute graft-versus-host disease diagnosis without classic apoptotic changes.


Assuntos
Anfirregulina/análise , Anfirregulina/biossíntese , Biomarcadores/análise , Doença Enxerto-Hospedeiro/diagnóstico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Receptores ErbB/análise , Feminino , Humanos , Intestinos/patologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
Transpl Int ; 31(12): 1405-1417, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29981183

RESUMO

Portable normothermic EVLP has been evaluated in clinical trials using standard and extended-criteria donor lungs. We describe a swine model of lung transplant following donation after circulatory death using prolonged normothermic EVLP to assess the relationship between EVLP data and acute lung allograft function. Adult swine were anesthetized and heparinized. In the control group (n = 4), lungs were procured, flushed, and transplanted. Treatment swine underwent either standard procurement (n = 3) or agonal hypoxia followed by 1 (n = 4) or 2 hours (H) (n = 4) of ventilated warm ischemia. Lungs were preserved for 24H using normothermic blood-based EVLP then transplanted. Recipients were monitored for 4 H. After 24H of preservation, mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and dynamic compliance (Cdyn ) were improved in all EVLP groups. After transplant, EVLP groups showed similar allograft oxygenation. EVLP PVR, mPAP, and lung block weights had significant negative correlations with post-transplant allograft oxygenation. EVLP P:F ratio did not correlate with acute post-transplant allograft function until 24H of preservation. Data measured in the first 8H of EVLP were sufficient for predicting acute post-transplant allograft function. This study provides a benchmark and platform for evaluation of therapies for donor-related allograft injury in injured lungs treated with prolonged normothermic EVLP.


Assuntos
Pneumopatias/cirurgia , Transplante de Pulmão/métodos , Pulmão/patologia , Perfusão , Aloenxertos , Animais , Modelos Animais de Doenças , Hemodinâmica , Hipóxia , Inflamação , Masculino , Preservação de Órgãos , Oxigênio/química , Edema Pulmonar , Traumatismo por Reperfusão , Suínos , Fatores de Tempo , Transplante Homólogo , Isquemia Quente
4.
Integr Environ Assess Manag ; 20(3): 725-748, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37417421

RESUMO

Despite advances in toxicity testing and the development of new approach methodologies (NAMs) for hazard assessment, the ecological risk assessment (ERA) framework for terrestrial wildlife (i.e., air-breathing amphibians, reptiles, birds, and mammals) has remained unchanged for decades. While survival, growth, and reproductive endpoints derived from whole-animal toxicity tests are central to hazard assessment, nonstandard measures of biological effects at multiple levels of biological organization (e.g., molecular, cellular, tissue, organ, organism, population, community, ecosystem) have the potential to enhance the relevance of prospective and retrospective wildlife ERAs. Other factors (e.g., indirect effects of contaminants on food supplies and infectious disease processes) are influenced by toxicants at individual, population, and community levels, and need to be factored into chemically based risk assessments to enhance the "eco" component of ERAs. Regulatory and logistical challenges often relegate such nonstandard endpoints and indirect effects to postregistration evaluations of pesticides and industrial chemicals and contaminated site evaluations. While NAMs are being developed, to date, their applications in ERAs focused on wildlife have been limited. No single magic tool or model will address all uncertainties in hazard assessment. Modernizing wildlife ERAs will likely entail combinations of laboratory- and field-derived data at multiple levels of biological organization, knowledge collection solutions (e.g., systematic review, adverse outcome pathway frameworks), and inferential methods that facilitate integrations and risk estimations focused on species, populations, interspecific extrapolations, and ecosystem services modeling, with less dependence on whole-animal data and simple hazard ratios. Integr Environ Assess Manag 2024;20:725-748. © 2023 His Majesty the King in Right of Canada and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Reproduced with the permission of the Minister of Environment and Climate Change Canada. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

5.
Integr Environ Assess Manag ; 20(3): 699-724, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37259706

RESUMO

Model species (e.g., granivorous gamebirds, waterfowl, passerines, domesticated rodents) have been used for decades in guideline laboratory tests to generate survival, growth, and reproductive data for prospective ecological risk assessments (ERAs) for birds and mammals, while officially adopted risk assessment schemes for amphibians and reptiles do not exist. There are recognized shortcomings of current in vivo methods as well as uncertainty around the extent to which species with different life histories (e.g., terrestrial amphibians, reptiles, bats) than these commonly used models are protected by existing ERA frameworks. Approaches other than validating additional animal models for testing are being developed, but the incorporation of such new approach methodologies (NAMs) into risk assessment frameworks will require robust validations against in vivo responses. This takes time, and the ability to extrapolate findings from nonanimal studies to organism- and population-level effects in terrestrial wildlife remains weak. Failure to adequately anticipate and predict hazards could have economic and potentially even legal consequences for regulators and product registrants. In order to be able to use fewer animals or replace them altogether in the long term, vertebrate use and whole organism data will be needed to provide data for NAM validation in the short term. Therefore, it is worth investing resources for potential updates to existing standard test guidelines used in the laboratory as well as addressing the need for clear guidance on the conduct of field studies. Herein, we review the potential for improving standard in vivo test methods and for advancing the use of field studies in wildlife risk assessment, as these tools will be needed in the foreseeable future. Integr Environ Assess Manag 2024;20:699-724. © 2023 His Majesty the King in Right of Canada and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Reproduced with the permission of the Minister of Environment and Climate Change Canada. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

6.
Med Sci Educ ; 33(2): 409-421, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36820280

RESUMO

The arrival of COVID-19 restrictions and the increasing demand of online instruction options posed challenges to education communities worldwide, especially in human anatomy. In response, Colorado State University developed and deployed an 8-week-long large-scale virtual reality (VR) course to supplement online human anatomy instruction. Students (n = 75) received a VR-capable laptop and head-mounted display and participated in weekly synchronous group laboratory sessions with instructors. The software enabled students to remotely collaborate in a common virtual space to work with human anatomy using an artist-rendered cadaver. Qualitative data were collected on student engagement, confidence, and reactions to the new technology. Quantitative data assessed student knowledge acquisition and retention of anatomical spatial relationships. Results indicated that students performed better in the online course (mean = 82.27%) when compared to previous in-person laboratories (mean = 80.08%). The utilization of VR promoted student engagement and increased opportunities for student interaction with teaching assistants, peers, and course content. Notably, students reported benefits that focused on unique aspects of their virtual learning environment, including the ability to infinitely scale the cadaver and walk inside and around anatomical structures. Results suggested that using VR was equivalent to 2D methods in student learning and retention of anatomical relationships. Overall, the virtual classroom maintained the rigor of traditional gross anatomy laboratories without negatively impacting student examination scores and provided a high level of accessibility, without compromising learner engagement. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-023-01751-w.

7.
Am J Emerg Med ; 30(7): 1048-54, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21855261

RESUMO

OBJECTIVES: Medication reconciliation is a Joint Commission for the Accreditation of Healthcare Organizations requirement to reduce medication errors. This study evaluated the reliability of patient-completed medication reconciliation forms (MRs) compared with pharmacy-generated lists and determined if there was a difference in concordance when patients completed the forms from memory compared with when they brought a separate list or pill bottles. METHODS: We prospectively enrolled patients with completed MRs. Research assistants contacted the patient's pharmacy to determine medications filled in the prior 3 months, which was compared with the MR. Discrepancies and the method by which the patient completed the MR (memory, list, or pill bottles) were recorded. RESULTS: Three hundred fifteen patients were enrolled. Thirty-three percent made errors of omission (reported by pharmacy, but not on MR), 12.7% made errors of addition (reported on MR, but not by pharmacy), 18.1% made both types of errors, and 36.3% made no errors. Patients with errors were on 5.6 medications compared with 3.6 medications for those without errors (P < .0001). Those completing the MR from a list made 2.3 errors compared with 1.2 for those completing from memory and 1.8 for those completing from their pill bottles (P < .001). Of 390 medications omitted from patient lists, 16% were cardiac medications, 13% were neuropsychiatric agents, and 9.5% were narcotics. CONCLUSIONS: Thirty-six percent of patients were able to provide a medication list that matched their pharmacy-prescribed drugs. More errors were noted from patients taking more medications and from those completing their MR from a separate list.


Assuntos
Reconciliação de Medicamentos/métodos , Farmácias , Registros , Autorrelato , Adulto , Feminino , Humanos , Masculino , Memória , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo
8.
PLoS One ; 17(8): e0273572, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36037158

RESUMO

Current estimates of terrestrial bird losses across Europe from ingestion of lead ammunition are based on uncertain or generic assumptions. A method is needed to develop defensible European-specific estimates compatible with available data that does not require long-term field studies. We propose a 2-step method using carcass data and population models. The method estimates percentage of deaths diagnosed as directly caused by lead poisoning as a lower bound and, as an upper bound, the percentage of possible deaths from sublethal lead poisoning that weakens birds, making them susceptible to death by other causes. We use these estimates to modify known population-level annual mortality. Our method also allows for potential reductions in reproduction from lead shot ingestion because reductions in survival and reproduction are entered into population models of species with life histories representative of the most groups of susceptible species. The models estimate the sustainability and potential population decreases from lead poisoning in Europe. Using the best available data, we demonstrate the method on two taxonomic groups of birds: gallinaceous birds and diurnal raptors. The direction of the population trends affects the estimate, and we incorporated such trends into the method. Our midpoint estimates of the reduction in population size of the European gallinaceous bird (< 2%) group and raptor group (2.9-7.7%) depend on the species life history, maximum growth rate, population trend, and if reproduction is assumed to be reduced. Our estimates can be refined as more information becomes available in countries with data gaps. We advocate use of this method to improve upon or supplement approaches currently being used. As we demonstrate, the method also can be applied to individual species of concern if enough data across countries are available.


Assuntos
Intoxicação por Chumbo , Aves Predatórias , Animais , Aves , Ingestão de Alimentos , Chumbo/toxicidade , Intoxicação por Chumbo/epidemiologia , Intoxicação por Chumbo/veterinária , Dinâmica Populacional
9.
Front Bioeng Biotechnol ; 9: 727869, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34485262

RESUMO

Tissue engineering using decellularized whole lungs as matrix scaffolds began as a promise for creating autologous transplantable lungs for patients with end-stage lung disease and can also be used to study strategies for lung regeneration. Vascularization remains a critical component for all solid organ bioengineering, yet there has been limited success in generating functional re-endothelialization of most pulmonary vascular segments. We evaluated recellularization of the blood vessel conduits of acellular mouse scaffolds with highly proliferating, rat pulmonary microvascular endothelial progenitor cells (RMEPCs), pulmonary arterial endothelial cells (PAECs) or microvascular endothelial cells (MVECs). After 8 days of pulsatile perfusion, histological analysis showed that PAECs and MVECs possessed selective tropism for larger vessels or microvasculature, respectively. In contrast, RMEPCs lacked site preference and repopulated all vascular segments. RMEPC-derived endothelium exhibited thrombomodulin activity, expression of junctional genes, ability to synthesize endothelial signaling molecules, and formation of a restrictive barrier. The RMEPC phenotype described here could be useful for identifying endothelial progenitors suitable for efficient vascular organ and tissue engineering, regeneration and repair.

10.
Ecology ; 91(11): 3177-88, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21141179

RESUMO

We explored the interacting effects of marine-derived nutrient fertilization and physical disturbance introduced by coastal river otters (Lontra canadensis) on the production and nutrient status of pristine shrub and tree communities in Prince William Sound, Alaska, USA. We compared production of trees and shrubs between latrines and non-latrines, while accounting for otter site selection, by sampling areas on and off sites. Nitrogen stable isotope analysis (delta15N) indicated that dominant tree and shrub species assimilated the marine-derived N excreted by otters. In association with this uptake, tree production increased, but shrub density and nonwoody aboveground shrub production decreased. The reduced shrub production was caused by destruction of ramets, especially blueberry (Vaccinium spp.), through physical disturbance by river otters. False azalea (Menziesia ferruginea) ramets were less sensitive to otter disturbance. Although surviving individual blueberry ramets showed a tendency for increased production per plant, false azalea allocated excess N to storage in leaves rather than growth. We found that plant responses to animal activity vary among species and levels of biological organization (leaf, plant, ecosystem). Such differences should be accounted for when assessing the influence of river otters on the carbon budget of Alaskan coastal forests at the landscape scale.


Assuntos
Ericaceae/fisiologia , Lontras/fisiologia , Árvores/fisiologia , Vaccinium/fisiologia , Alaska , Animais , Ecossistema , Fertilizantes , Rios
11.
J Med Educ Curric Dev ; 7: 2382120520941822, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32775692

RESUMO

Using cadaveric instruction in a graduate-level anatomy course is an expensive and time-consuming undertaking. While this is a worthwhile endeavor, most first-year medical students and students in the health fields struggle with the independent, self-directed learning approach in the cadaveric laboratory, and going beyond rote memorization of the material. As such, effective assessment tools that maximize student learning in the cadaveric laboratory are critical, especially if no lecture component is present. Dissection quality often reflects student attention to detail and therefore may be tied to overall performance in the course. The aim of this study was to investigate the relationship between weekly table quizzes and the overall student outcomes in a graduate biomedical human dissection class as well as examining the benefits and implications of this approach. In this course, a uniquely structured weekly quiz assessed dissection quality and probed student understanding in human anatomy. Student data compiled from 5 years of dissection courses were analyzed to evaluate the relationship between performance in the weekly assessment and on the unit examinations. The results showed a statistically significant relationship between the weekly quizzes and the student examinations at the end of each dissection block in 2013, 2015, 2016, and 2017. The data suggest a potential correlation between performance on weekly quizzes and on unit examinations. The unique nature of the table quizzes provides the students with the opportunity to practice the retrieval of their knowledge, feel more guided throughout their dissection, and receive immediate feedback on their performance. This assessment tool also provides a way to predict student outcomes and an opportunity for early intervention to help at-risk students. The analysis of this research study contributes to the need for more data on the usage of assessment tools in a graduate human dissection class.

12.
Adv Mater ; 31(10): e1806899, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30663123

RESUMO

The development of 3D in vitro models capable of recapitulating native tumor microenvironments could improve the translatability of potential anticancer drugs and treatments. Here, 3D bioprinting techniques are used to build tumor constructs via precise placement of living cells, functional biomaterials, and programmable release capsules. This enables the spatiotemporal control of signaling molecular gradients, thereby dynamically modulating cellular behaviors at a local level. Vascularized tumor models are created to mimic key steps of cancer dissemination (invasion, intravasation, and angiogenesis), based on guided migration of tumor cells and endothelial cells in the context of stromal cells and growth factors. The utility of the metastatic models for drug screening is demonstrated by evaluating the anticancer efficacy of immunotoxins. These 3D vascularized tumor tissues provide a proof-of-concept platform to i) fundamentally explore the molecular mechanisms of tumor progression and metastasis, and ii) preclinically identify therapeutic agents and screen anticancer drugs.


Assuntos
Biomimética , Neoplasias , Impressão Tridimensional , Engenharia Tecidual , Microambiente Tumoral , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Neoplasias/patologia , Alicerces Teciduais/química
13.
J Cardiovasc Transl Res ; 12(4): 271-279, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30680546

RESUMO

Dyspnea is a major symptom of heart failure (HF). Here, we have studied the lung remodeling and airway resistance in HF mice. We demonstrated that aortic banding-induced HF caused a dramatic decrease of lung compliance and an increase of lung airway resistance. The decrease of lung compliance was correlated with the increased lung weight in a linear fashion (γ2 = 0.824). An HF-induced increase of lung airway resistance and a decrease of lung compliance were almost identical in anesthetized mice and in the isolated lungs from these mice. HF caused profound lung fibrosis in mice with increased lung weight. Moreover, HF patients of NYHA class III-IV showed increased lung density as revealed by high-resolution CT scanning. These data indicate that lung compliance and lung airway resistance may be useful in determining lung remodeling after HF, and lung structure changes may contribute to dyspnea in HF.


Assuntos
Remodelação das Vias Aéreas , Resistência das Vias Respiratórias , Dispneia/etiologia , Insuficiência Cardíaca/complicações , Pulmão/fisiopatologia , Fibrose Pulmonar/etiologia , Animais , Modelos Animais de Doenças , Dispneia/diagnóstico por imagem , Dispneia/patologia , Dispneia/fisiopatologia , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fibrose Pulmonar/diagnóstico por imagem , Fibrose Pulmonar/patologia , Fibrose Pulmonar/fisiopatologia , Volume Sistólico , Tomografia Computadorizada por Raios X , Função Ventricular Esquerda
14.
Artigo em Inglês | MEDLINE | ID: mdl-30377470

RESUMO

Both research and practical experience in education support the use of case studies in the classroom to engage students and develop critical thinking skills. In particular, working through case studies in scientific disciplines encourages students to incorporate knowledge from a variety of backgrounds and apply a breadth of information. While it is recognized that critical thinking is important for student success in professional school and future careers, a specific strategy to tackle a novel problem is lacking in student training. We have developed a four-step systematic approach to solving case studies that improves student confidence and provides them with a definitive road map that is useful when solving any novel problem, both in and out of the classroom. This approach encourages students to define unfamiliar terms, create a timeline, describe the systems involved, and identify any unique features. This method allows students to solve complex problems by organizing and applying information in a logical progression. We have incorporated case studies in anatomy and neuroanatomy courses and are confident that this systematic approach will translate well to courses in various scientific disciplines.

15.
Radiother Oncol ; 124(3): 468-474, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28778346

RESUMO

PURPOSE: To develop a murine total marrow irradiation (TMI) model in comparison with the total body irradiation (TBI) model. MATERIALS AND METHODS: Myeloablative TMI and TBI were administered in mice using a custom jig, and the dosimetric differences between TBI and TMI were evaluated. The early effects of TBI/TMI on bone marrow (BM) and organs were evaluated using histology, FDG-PET, and cytokine production. TMI and TBI with and without cyclophosphamide (Cy) were evaluated for donor cell engraftment and tissue damage early after allogeneic hematopoietic cell transplantation (HCT). Stromal derived factor-1 (SDF-1) expression was evaluated. RESULTS: TMI resulted in similar dose exposure to bone and 50% reduction in dose to bystander organs. BM histology was similar between the groups. In the non-HCT model, TMI mice had significantly less acute intestinal and lung injury compared to TBI. In the HCT model, recipients of TMI had significantly less acute intestinal injury and spleen GVHD, but increased early donor cell engraftment and BM:organ SDF-1 ratio compared to TBI recipients. CONCLUSIONS: The expected BM damage was similar in both models, but the damage to other normal tissues was reduced by TMI. However, BM engraftment was improved in the TMI group compared to TBI, which may be due to enhanced production of SDF-1 in BM relative to other organs after TMI.


Assuntos
Medula Óssea/efeitos da radiação , Irradiação Corporal Total , Anfirregulina/análise , Animais , Fator de Crescimento Epidérmico/análise , Feminino , Transplante de Células-Tronco Hematopoéticas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Doses de Radiação
16.
Transplantation ; 101(10): 2303-2311, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28009782

RESUMO

BACKGROUND: We report the ability to extend lung preservation up to 24 hours (24H) by using autologous whole donor blood circulating within an ex vivo lung perfusion (EVLP) system. This approach facilitates donor lung reconditioning in a model of extended normothermic EVLP. We analyzed comparative responses to cellular and acellular perfusates to identify these benefits. METHODS: Twelve pairs of swine lungs were retrieved after cardiac arrest and studied for 24H on the Organ Care System (OCS) Lung EVLP platform. Three groups (n = 4 each) were differentiated by perfusate: (1) isolated red blood cells (RBCs) (current clinical standard for OCS); (2) whole blood (WB); and (3) acellular buffered dextran-albumin solution (analogous to STEEN solution). RESULTS: Only the RBC and WB groups met clinical standards for transplantation at 8 hours; our primary analysis at 24H focused on perfusion with WB versus RBC. The WB perfusate was superior (vs RBC) for maintaining stability of all monitored parameters, including the following mean 24H measures: pulmonary artery pressure (6.8 vs 9.0 mm Hg), reservoir volume replacement (85 vs 1607 mL), and PaO2:FiO2 ratio (541 vs 223). Acellular perfusion was limited to 6 hours on the OCS system due to prohibitively high vascular resistance, edema, and worsening compliance. CONCLUSIONS: The use of an autologous whole donor blood perfusate allowed 24H of preservation without functional deterioration and was superior to both RBC and buffered dextran-albumin solution for extended lung preservation in a swine model using OCS Lung. This finding represents a potentially significant advance in donor lung preservation and reconditioning.


Assuntos
Eritrócitos , Circulação Extracorpórea/métodos , Transplante de Pulmão/métodos , Pulmão/irrigação sanguínea , Pulmão/efeitos dos fármacos , Soluções para Preservação de Órgãos/farmacologia , Preservação de Órgãos/métodos , Perfusão/métodos , Animais , Eritrócitos/metabolismo , Parada Cardíaca , Hemodinâmica , Pulmão/patologia , Pulmão/cirurgia , Lesão Pulmonar/etiologia , Transplante de Pulmão/efeitos adversos , Masculino , Modelos Animais , Preservação de Órgãos/efeitos adversos , Oxigênio/sangue , Perfusão/efeitos adversos , Pneumonia/etiologia , Circulação Pulmonar , Edema Pulmonar/etiologia , Traumatismo por Reperfusão/etiologia , Sus scrofa , Fatores de Tempo , Sobrevivência de Tecidos/efeitos dos fármacos
17.
PLoS One ; 11(1): e0147716, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26824231

RESUMO

Selenium is an essential element required for activity of several antioxidant enzymes, including glutathione peroxidase. Because of the critical role of the antioxidant system in responding to traumatic events, we hypothesized that dietary selenium supplementation would enhance neuroprotection in a rodent model of spinal cord injury. Rats were maintained on either a control or selenium-enriched diet prior to, and following, injury. Dietary selenium supplementation, provided as selenized yeast added to normal rat chow, resulted in a doubling of selenium levels in the spinal cord. Dietary selenium reduced the time required for recovery of bladder function following thoracic spinal cord injury. However, this was not accompanied by improvement in locomotor function or tissue sparing.


Assuntos
Suplementos Nutricionais , Locomoção/efeitos dos fármacos , Compostos Organosselênicos/uso terapêutico , Traumatismos da Medula Espinal/tratamento farmacológico , Medula Espinal/efeitos dos fármacos , Bexiga Urinária/efeitos dos fármacos , Animais , Suplementos Nutricionais/análise , Feminino , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Bexiga Urinária/fisiopatologia
18.
PLoS One ; 11(1): e0147189, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26799815

RESUMO

Little is known about the magnitude of the effects of lead shot ingestion alone or combined with poisons (e.g., in bait or seeds/granules containing pesticides) on population size, growth, and extinction of non-waterbird avian species that ingest these substances. We used population models to create example scenarios demonstrating how changes in these parameters might affect three susceptible species: grey partridge (Perdix perdix), common buzzard (Buteo buteo), and red kite (Milvus milvus). We added or subtracted estimates of mortality due to lead shot ingestion (4-16% of mortality, depending on species) and poisons (4-46% of mortality) reported in the UK or France to observed mortality of studied populations after models were calibrated to observed population trends. Observed trends were decreasing for partridge (in continental Europe), stable for buzzard (in Germany), and increasing for red kite (in Wales). Although lead shot ingestion and poison at modeled levels did not change the trend direction for the three species, they reduced population size and slowed population growth. Lead shot ingestion at modeled rates reduced population size of partridges by 10%, and when combined with bait and pesticide poisons, by 18%. For buzzards, decrease in mean population size by lead shot and poisons combined was much smaller (≤ 1%). The red kite population has been recovering; however, modeled lead shot ingestion reduced its annual growth rate from 6.5% to 4%, slowing recovery. If mortality from poisoned baits could be removed, the kite population could potentially increase at a rapid annual rate of 12%. The effects are somewhat higher if ingestion of these substances additionally causes sublethal reproductive impairment. These results have uncertainty but suggest that declining or recovering populations are most sensitive to lead shot or poison ingestion, and removal of poisoned baits can have a positive impact on recovering raptor populations that frequently feed on carrion.


Assuntos
Aves/crescimento & desenvolvimento , Chumbo/toxicidade , Animais , Europa (Continente) , Humanos , Crescimento Demográfico
19.
PLoS One ; 11(3): e0150966, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26954258

RESUMO

The lung changes functionally and structurally with aging. However, age-related effects on the extracellular matrix (ECM) and corresponding effects on lung cell behavior are not well understood. We hypothesized that ECM from aged animals would induce aging-related phenotypic changes in healthy inoculated cells. Decellularized whole organ scaffolds provide a powerful model for examining how ECM cues affect cell phenotype. The effects of age on ECM composition in both native and decellularized mouse lungs were assessed as was the effect of young vs old acellular ECM on human bronchial epithelial cells (hBECs) and lung fibroblasts (hLFs). Native aged (1 year) lungs demonstrated decreased expression of laminins α3 and α4, elastin and fibronectin, and elevated collagen, compared to young (3 week) lungs. Proteomic analyses of decellularized ECM demonstrated similar findings, and decellularized aged lung ECM contained less diversity in structural proteins compared to young ECM. When seeded in old ECM, hBECs and hLFs demonstrated lower gene expression of laminins α3 and α4, respectively, as compared to young ECM, paralleling the laminin deficiency of aged ECM. ECM changes appear to be important factors in potentiating aging-related phenotypes and may provide clues to mechanisms that allow for aging-related lung diseases.


Assuntos
Células Epiteliais Alveolares/metabolismo , Fibroblastos/metabolismo , Expressão Gênica , Laminina/genética , Fatores Etários , Animais , Caderinas/genética , Caderinas/metabolismo , Técnicas de Cultura de Células , Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Feminino , Perfilação da Expressão Gênica , Laminina/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos , Fenótipo , Tromboplastina/genética , Tromboplastina/metabolismo
20.
Integr Environ Assess Manag ; 11(1): 56-66, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25345977

RESUMO

Coal-fly ash was released in unprecedented amounts (4.1 × 10(6) m(3) ) into the Emory River from the Tennessee Valley Authority Kingston Fossil Plant on Watts Bar Reservoir in Tennessee. Tree swallows were exposed to ash-related constituents at the ash release via their diet of emergent aquatic insects, whose larval forms can accumulate constituents from submerged river sediments. Reproduction of tree swallow colonies was assessed over a 2-year period by evaluating whether 1) ash constituent concentrations were elevated in egg, eggshell, and nestling tissues at colonies near ash-impacted river reaches compared to reference colonies, 2) production of fledglings per nesting female was significantly lower in ash-impacted colonies versus reference colonies, and 3) ash constituent concentrations or diet concentrations were correlated with nest productivity measures (clutch size, hatching success, and nestling survival, and fledglings produced per nest). Of the 26 ash constituents evaluated, 4 (Se, Sr, Cu, and Hg) were significantly elevated in tissues potentially from the ash, and 3 (Se, Sr, and Cu) in tissues or in swallow diet items were weakly correlated to at least one nest-productivity measure or egg weight. Tree swallow hatching success was significantly reduced by 12%, but fledgling production per nest was unaffected due to larger clutch sizes in the impacted than reference colonies. Bioconcentration from the ash to insects in the diet to tree swallow eggs appears to be low. Overall, adverse impacts of the ash on tree swallow reproduction were not observed, but monitoring is continuing to further ensure Se from the residual ash does not adversely affect tree swallow reproduction over time. Integr Environ Assess Manag 2015;11:56-66. © 2014 SETAC.


Assuntos
Vazamento de Resíduos Químicos , Cinza de Carvão , Andorinhas/fisiologia , Animais , Animais Recém-Nascidos , Arsênio/análise , Monitoramento Ambiental , Ephemeroptera/química , Feminino , Cadeia Alimentar , Metais/análise , Reprodução , Tennessee , Poluentes Químicos da Água/análise , Zigoto/química
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