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2.
Immunooncol Technol ; 19: 100394, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37519414

RESUMO

Adenosine is a potent immunosuppressive metabolite that accumulates in the extracellular space within solid tumors and inhibits the antitumor function of native immune cell responses as well as chimeric antigen receptor (CAR) T-cell therapies. Here, we show that engineered human cells can degrade extracellular adenosine through secretion of adenosine deaminase (ADA) enzymes-a possible therapeutic enhancement for CAR T cells. We first determine that the high-activity ADA1 isoform is naturally intracellularly restricted and show that the addition of canonical or computationally predicted secretory peptides did not allow for improved secretion. We did, however, determine that the lower-activity ADA2 isoform is naturally secreted. Thus, we utilized phylogenetic-based structural comparisons to guide a mutational survey of ADA2 active site residues, which when coupled with a high-throughput screen for enhanced ADA2-mediated extracellular adenosine rate allowed isolation of the most catalytically efficient ADA2 variant reported to date. When expressed by human cells, this variant exhibits 30× higher extracellular adenosine degradation activity than the wild-type enzyme. Finally, we demonstrate that Jurkat and CAR T cells engineered to express this secreted, high-activity ADA2 variant can degrade significant amounts of extracellular adenosine in vitro.

3.
Science ; 373(6559): 1156-1161, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34516839

RESUMO

Dominant mutations in ubiquitously expressed transfer RNA (tRNA) synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth (CMT) disease. Genetic evidence in mouse and Drosophila models suggests a gain-of-function mechanism. In this study, we used in vivo, cell type­specific transcriptional and translational profiling to show that mutant tRNA synthetases activate the integrated stress response (ISR) through the sensor kinase GCN2 (general control nonderepressible 2). The chronic activation of the ISR contributed to the pathophysiology, and genetic deletion or pharmacological inhibition of Gcn2 alleviated the peripheral neuropathy. The activation of GCN2 suggests that the aberrant activity of the mutant tRNA synthetases is still related to translation and that inhibiting GCN2 or the ISR may represent a therapeutic strategy in CMT.


Assuntos
Doença de Charcot-Marie-Tooth/metabolismo , Glicina-tRNA Ligase/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Estresse Fisiológico , Tirosina-tRNA Ligase/metabolismo , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Animais , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/fisiopatologia , Modelos Animais de Doenças , Feminino , Deleção de Genes , Genes Dominantes , Glicina-tRNA Ligase/genética , Masculino , Camundongos , Camundongos Mutantes , Neurônios Motores/fisiologia , Biossíntese de Proteínas , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Medula Espinal/fisiopatologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Transcriptoma , Tirosina-tRNA Ligase/genética
4.
Int J Psychophysiol ; 158: 340-348, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33080287

RESUMO

Alterations in error processing are implicated in a range of DSM-defined psychiatric disorders. For instance, obsessive-compulsive disorder (OCD) and generalised anxiety disorder show enhanced electrophysiological responses to errors-i.e. error-related negativity (ERN)-while others like schizophrenia have an attenuated ERN. However, as diagnostic categories in psychiatry are heterogeneous and also highly intercorrelated, the precise mapping of ERN enhancements/impairments is unclear. To address this, we recorded electroencephalograms (EEG) from 196 participants who performed the Flanker task and collected scores on 9 questionnaires assessing psychiatric symptoms to test if a dimensional framework could reveal specific transdiagnostic clinical manifestations of error processing dysfunctions. Contrary to our hypothesis, we found non-significant associations between ERN amplitude and symptom severity of OCD, trait anxiety, depression, social anxiety, impulsivity, eating disorders, alcohol addiction, schizotypy and apathy. A transdiagnostic approach did nothing to improve signal; there were non-significant associations between all three transdiagnostic dimensions (anxious-depression, compulsive behaviour and intrusive thought, and social withdrawal) and ERN magnitude. In these same individuals, we replicated a previously published transdiagnostic association between goal-directed learning and compulsive behaviour and intrusive thought. Possible explanations discussed are (i) that associations between the ERN and psychopathology might be smaller than previously assumed, (ii) that these associations might depend on a greater level of symptom severity than other transdiagnostic cognitive biomarkers, or (iii) that task parameters, such as the ratio of compatible to incompatible trials, might be crucial for ensuring the sensitivity of the ERN to clinical phenomena.


Assuntos
Potenciais Evocados , Transtorno Obsessivo-Compulsivo , Encéfalo , Eletroencefalografia , Humanos , Autorrelato
5.
Sci Adv ; 6(11): eaax7515, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32195339

RESUMO

Many pathogens produce virulence factors that are specific toward their natural host. Clinically relevant methicillin-resistant Staphylococcus aureus (MRSA) isolates are highly adapted to humans and produce an array of human-specific virulence factors. One such factor is LukAB, a recently identified pore-forming toxin that targets human phagocytes by binding to the integrin component CD11b. LukAB exhibits strong tropism toward human, but not murine, CD11b. Here, phylogenetics and biochemical studies lead to the identification of an 11-residue domain required for the specificity of LukAB toward human CD11b, which is sufficient to render murine CD11b compatible with toxin binding. CRISPR-mediated gene editing was used to replace this domain, resulting in a "humanized" mouse. In vivo studies revealed that the humanized mice exhibit enhanced susceptibility to MRSA bloodstream infection, a phenotype mediated by LukAB. Thus, these studies establish LukAB as an important toxin for MRSA bacteremia and describe a new mouse model to study MRSA pathobiology.


Assuntos
Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Antígeno CD11b/metabolismo , Leucocidinas/metabolismo , Staphylococcus aureus Resistente à Meticilina/metabolismo , Infecções Estafilocócicas/metabolismo , Fatores de Virulência/metabolismo , Animais , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Antígeno CD11b/genética , Células HL-60 , Humanos , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Camundongos , Camundongos Transgênicos , Infecções Estafilocócicas/genética , Fatores de Virulência/genética
6.
Biochem Biophys Res Commun ; 507(1-4): 173-177, 2018 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-30415777

RESUMO

N-glycolylneuraminic acid (Neu5Gc)-containing glycans are a prominent form of aberrant glycosylation found in human tumor cells and have been proposed as cancer biomarkers. The B subunit of the subtilase cytotoxin (SubB) produced by Shiga toxigenic Escherichia coli recognises Neu5Gc containing glycans. We have previously engineered this lectin, SubB2M, for greater specificity and enhanced recognition of Neu5Gc-containing glycans. Here we further explore the utility of SubB2M to detect Neu5Gc tumor biomarkers in sera from patients with ovarian cancer. Using surface plasmon resonance (SPR) we show that SubB2M can detect the established ovarian cancer biomarker, CA125, in a highly sensitive and specific fashion in the context of human serum. These studies established conditions for screening serum samples from patients with ovarian cancer for Neu5Gc glycans. We found that serum from patients with all stages of ovarian cancer had significantly elevated mean levels of Neu5Gc glycans compared to normal controls. Serum from patients with late stage disease (stages IIIC, IV) had uniformly elevated levels of Neu5Gc glycans. Detection of Neu5Gc-glycans using SubB2M has the potential to be used as a diagnostic ovarian cancer biomarker, as well as a tool for monitoring treatment and disease progression in late stage disease.


Assuntos
Biomarcadores Tumorais/sangue , Lectinas/metabolismo , Ácidos Neuramínicos/sangue , Neoplasias Ovarianas/sangue , Engenharia de Proteínas , Antígeno Ca-125/metabolismo , Feminino , Humanos , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia , Ressonância de Plasmônio de Superfície
7.
BMJ Open ; 8(8): e021445, 2018 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-30127050

RESUMO

INTRODUCTION: Health outcomes have been associated with physical and social characteristics of neighbourhoods, but little is known about the relationship between contextual factors and perceived neighbourhood scale. OBJECTIVE: To identify the contextual factors associated with self-perceived neighbourhood scale. METHODS: We analysed data from a cross-sectional population-based study in Belo Horizonte, Brazil, that took place in 2008-2009. The dependent variable was perceived neighbourhood, encoded as an ordinal scale based on a brief description of the concept of the neighbourhood, and two independent scales relating distance, expressed in terms of geography and time. Street connectivity, demographic density and residents' perceptions of the neighbourhoods' physical and social environment were used as contextual predictors. Individual characteristics were used as covariates. Multilevel ordinal logistic regression models estimated the association between perceived neighbourhood scale and contextual characteristics. RESULTS: Residents that perceive better walkability (OR 2.96; 95% CI 1.29 to 3.82) and high amounts of violence (OR 1.35; 95% CI 1.12 to 1.62) perceived their neighbourhoods to be larger, even after adjusting for individual characteristics. CONCLUSION: There are contextual factors that are associated with self-perceived neighbourhood scale. Careful definition of neighbourhood scale is a key factor in improving the results of eco-epidemiological studies. Although these findings must be further explored in other studies, these results can contribute to a better understanding of an appropriate choice of neighbourhood scale, especially for cities in Latin America.


Assuntos
Planejamento Ambiental/estatística & dados numéricos , Características de Residência/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Cidades/estatística & dados numéricos , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Meio Social , Saúde da População Urbana/estatística & dados numéricos , População Urbana/estatística & dados numéricos , Adulto Jovem
8.
Breast Dis ; 37(3): 147-154, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29376844

RESUMO

BACKGROUND: Breast cancer is the leading cause of cancer death in Hispanic/Latina women nationwide. Limited cancer research has been conducted in this population. El Paso, Texas is a large border city with a population of around 900,000, of which 85% are Latinos and would provide a suitable setting for this study. The aim of this study is to evaluate ethnic differences and cancer characteristics in Hispanic/latina women with breast cancer. METHODS: After IRB approval, we retrospectively analyzed the variables of patients with breast cancer treated consecutively at a large tertiary medical center in El Paso, TX between 2005-2015. Descriptive statistics, bivariate, and multivariable analyses were conducted. RESULTS: 1,252 patients were identified. Mean age at diagnosis was 57 years. 1074 were Hispanics/Latinas (86%). When comparing Hispanics versus non-Hispanics, 31% of Hispanics compared to 24% Non-Hispanics were diagnosed at age <50 (P = 0.043). More Hispanics are uninsured (34%) compared to Non-Hispanics (25%) (p = 0.008). Hispanics presenting with advanced stages were more likely to be uninsured (P = 0.02). CONCLUSIONS: This analysis confirms that Hispanics/Latinas are diagnosed with breast cancer at a younger age and are more commonly uninsured than Non-Hispanics. We did not observe significant differences in the prevalence of ER+, triple negative or Her2 -neu positive disease or stages at presentation between the 2 groups in this cohort, however the non-Hispanic group was constituted only 14% of the studied population. A larger multi-institutional comparative study is being conducted to confirm these findings.


Assuntos
Neoplasias da Mama/etiologia , Neoplasias da Mama/patologia , Hispânico ou Latino , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Fatores de Risco , Centros de Atenção Terciária , Texas
10.
Sci Rep ; 7(1): 1601, 2017 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-28487520

RESUMO

Meckel syndrome (MKS) is an inherited autosomal recessive hepatorenal fibrocystic syndrome, caused by mutations in TMEM67, characterized by occipital encephalocoele, renal cysts, hepatic fibrosis, and polydactyly. Here we describe an ovine model of MKS, with kidney and liver abnormalities, without polydactyly or occipital encephalocoele. Homozygous missense p.(Ile681Asn; Ile687Ser) mutations identified in ovine TMEM67 were pathogenic in zebrafish phenotype rescue assays. Meckelin protein was expressed in affected and unaffected kidney epithelial cells by immunoblotting, and in primary cilia of lamb kidney cyst epithelial cells by immunofluorescence. In contrast to primary cilia of relatively consistent length and morphology in unaffected kidney cells, those of affected cyst-lining cells displayed a range of short and extremely long cilia, as well as abnormal morphologies, such as bulbous regions along the axoneme. Putative cilia fragments were also consistently located within the cyst luminal contents. The abnormal ciliary phenotype was further confirmed in cultured interstitial fibroblasts from affected kidneys. These primary cilia dysmorphologies and length control defects were significantly greater in affected cells compared to unaffected controls. In conclusion, we describe abnormalities involving primary cilia length and morphology in the first reported example of a large animal model of MKS, in which we have identified TMEM67 mutations.


Assuntos
Anormalidades Múltiplas/genética , Síndrome de Dandy-Walker/genética , Síndrome Hepatorrenal/genética , Proteínas de Membrana/genética , Mutação/genética , Cisto Pancreático/genética , Anormalidades Múltiplas/patologia , Substituição de Aminoácidos , Animais , Sequência de Bases , Cromossomos de Mamíferos/genética , Cílios/patologia , Síndrome de Dandy-Walker/patologia , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Loci Gênicos , Complexo de Golgi/metabolismo , Síndrome Hepatorrenal/patologia , Homozigoto , Rim/patologia , Proteínas de Membrana/química , Mutação de Sentido Incorreto/genética , Cisto Pancreático/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ovinos , Peixe-Zebra
11.
Parasitology ; 143(14): 1847-1861, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27608857

RESUMO

Notoedric mange, caused by obligately parasitic sarcoptiform Notoedres mites, is associated with potentially fatal dermatitis with secondary systemic disease in small mammals, felids and procyonids among others, as well as an occasional zoonosis. We describe clinical spectra in non-chiropteran hosts, review risk factors and summarize ecological and epidemiological studies. The genus is disproportionately represented on rodents. Disease in felids and procyonids ranges from very mild to death. Knowledge of the geographical distribution of the mites is highly inadequate, with focal hot spots known for Notoedres cati in domestic cats and bobcats. Predisposing genetic and immunological factors are not known, except that co-infection with other parasites and anticoagulant rodenticide toxicoses may contribute to severe disease. Treatment of individual animals is typically successful with macrocytic lactones such as selamectin, but herd or wildlife population treatment has not been undertaken. Transmission requires close contact and typically is within a host species. Notoedric mange can kill half all individuals in a population and regulate host population below non-diseased density for decades, consistent with frequency-dependent transmission or spillover from other hosts. Epidemics are increasingly identified in various hosts, suggesting global change in suitable environmental conditions or increased reporting bias.


Assuntos
Doenças do Gato/parasitologia , Infestações por Ácaros/veterinária , Ácaros/fisiologia , Animais , Animais Selvagens/parasitologia , Gatos/parasitologia , Coinfecção/parasitologia , Coinfecção/veterinária , Estágios do Ciclo de Vida , Lynx/parasitologia , Infestações por Ácaros/tratamento farmacológico , Infestações por Ácaros/epidemiologia , Infestações por Ácaros/parasitologia , Ácaros/classificação , Ácaros/crescimento & desenvolvimento , Animais de Estimação/parasitologia , Doenças dos Roedores/parasitologia , Roedores , Pele/parasitologia , Urbanização
12.
Acad Med ; 91(6): 751, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27218900
14.
J Anim Sci ; 93(12): 5791-800, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26641189

RESUMO

English × Continental heifers ( = 180) were sourced in 2 loads (219.3 ± 16.0 and 221.4 ± 16.4 kg, respectively) from commercial auction barns to study the effects of feeding dehydrated citrus pulp (DCP) on feedlot performance of newly received heifers. A completely randomized block design was used with BW nested within arrival load and blocked by BW into 3 dietary treatments (36 pens, 5 heifers/pen, 12 blocks, 3 pens/block, and 12 pens/treatment). Treatment diets contained 1) 0% DCP (control diet [CON]), 2) 10% DCP, or 3) 20% DCP on a DM basis. Diets containing DCP were exchanged with steam-flaked corn on a 1:1 basis. Cattle were fed a 63, 73, and 83% concentrate diet from d 0 to 28, d 28 to 42, and d 42 to 56, respectively. Over the 56-d trial period, as the amount of dietary DCP increased, DMI decreased ( = 0.01), ADG decreased ( < 0.01), and G:F decreased ( = 0.02). From d 0 to 28, there was no difference in the observed minus the predicted NEg of the diet ( = 0.73); from d 28 to 42, there was a linear increase in NEg favoring DCP treatments ( < 0.01); and from d 42 to 56, there was a linear decrease in NEg against the DCP treatments ( < 0.01). At the conclusion of the trial, a subset of heifers ( = 22; 307.89 ± 3.32 kg on d 63) were used to evaluate blood metabolite concentrations before and after a lipopolysaccharide (LPS) challenge. On d 63, heifers were fitted with jugular catheters and moved into individual stalls. On d 64, heifers were intravenously challenged with LPS (0.5 µg/kg BW), and blood samples were collected every 0.5 h from -2 to 8 h and at 24 h relative to the LPS challenge (0 h). Serum glucose, serum urea nitrogen (SUN), and NEFA concentrations were determined. Cattle lost less weight at both 24 and 72 h after the LPS challenge with increasing DCP percentage ( < 0.01). Glucose ( = 0.12) and NEFA ( = 0.13) concentrations did not differ before the LPS challenge; however, there was a treatment effect for SUN, with elevated concentrations of SUN in CON cattle ( < 0.01). After the LPS challenge, DCP-fed cattle had reduced glucose, elevated NEFA, and reduced SUN concentrations ( ≤ 0.01). Results indicate that dietary DCP modulated metabolite concentrations in heifers following an endotoxin challenge and affected feedlot performance when incorporated in receiving diets in replacement of corn. Future studies will need to address strategies to increase DMI or explore levels of DCP less than 10% in the diet of newly received heifer calves.


Assuntos
Ração Animal , Bovinos/fisiologia , Citrus/química , Lipopolissacarídeos/toxicidade , Ração Animal/análise , Animais , Glicemia/análise , Nitrogênio da Ureia Sanguínea , Peso Corporal , Bovinos/sangue , Bovinos/crescimento & desenvolvimento , Dessecação , Dieta/veterinária , Ácidos Graxos não Esterificados/sangue , Feminino , Lipopolissacarídeos/administração & dosagem , Distribuição Aleatória
15.
Acad Med ; 90(9): 1246-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26177527

RESUMO

The problem of poor mental health in residency is well established. Burnout, depression, and suicidal ideation are prevalent among resident physicians, and these problems appear to persist into practice. Leaders in graduate medical education such as policy makers at the Accreditation Council for Graduate Medical Education (ACGME) and directors of individual programs and institutions should acknowledge these important issues and take steps to address them. The ACGME's Clinical Learning Environment Review (CLER) Program currently outlines an expectation that institutions both educate residents about burnout and measure burnout annually. The CLER Program could go further by expecting institutions to create quality initiatives to enhance resident wellness and increase resident engagement. The ACGME should also call for and support research in this area. Leaders or directors of individual programs and institutions should consider wellness initiatives that both (1) identify and address suboptimal aspects of the learning environment and (2) train residents in resilience skills. Efforts to improve the residency learning environment could be guided by the work of Maslach and Leiter, who describe six categories of work stress that can contribute to burnout: (1) workload, (2) control, (3) balance between effort and reward, (4) community, (5) fairness, and (6) values.


Assuntos
Esgotamento Profissional/psicologia , Depressão/psicologia , Educação de Pós-Graduação em Medicina/métodos , Internato e Residência/métodos , Saúde Mental , Médicos/psicologia , Meio Social , Carga de Trabalho/psicologia , Acreditação , Educação de Pós-Graduação em Medicina/organização & administração , Humanos , Internato e Residência/organização & administração , Cultura Organizacional , Estresse Psicológico/psicologia
16.
J Neurol Sci ; 355(1-2): 84-9, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26073484

RESUMO

BACKGROUND: Although multiple sclerosis (MS) is thought to represent an excessive and inappropriate immune response to several central nervous system (CNS) autoantigens, increasing evidence also suggests that MS may also be a neurovascular inflammatory disease, characterized by endothelial activation and shedding of cell membrane microdomains known as 'microparticles' into the circulation. OBJECTIVE: To investigate the relationships between these endothelial biomarkers and MS. METHODS: We examined the relative abundance of CD31(+)/PECAM-1, CD51(+)CD61(+) (αV-ß3) and CD54(+) (ICAM-1) bearing microparticles in sera of healthy individuals, patients with relapsing-remitting MS, and secondary-progressive MS. We also investigated the correlation among circulating levels of different microparticle species in MS with conventional MRI (T2- and T1-lesion volumes and brain atrophy), as well as novel MR modalities [assessment of iron content on susceptibility-weighted imaging (SWI)-filtered phase]. RESULTS: Differences in circulating microparticle levels were found among MS groups, and several microparticle species (CD31(+)/CD51(+)/CD61(+)/CD54(+)) were found to correlate with conventional MRI and SWI features of MS. CONCLUSION: These results indicate that circulating microparticles' profiles in MS may support mechanistic roles for microvascular stress and injury which is an underlying contributor not only to MS initiation and progression, but also to pro-inflammatory responses.


Assuntos
Antígenos CD/sangue , Encéfalo/patologia , Esclerose Múltipla Crônica Progressiva/sangue , Esclerose Múltipla Crônica Progressiva/patologia , Esclerose Múltipla Recidivante-Remitente/sangue , Esclerose Múltipla Recidivante-Remitente/patologia , Adulto , Estudos de Casos e Controles , Estudos Transversais , Feminino , Citometria de Fluxo , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
17.
Nanotechnology ; 26(11): 115203, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25719801

RESUMO

The gallium nitride (GaN)-based buffer/barrier mode of growth and morphology, the transistor electrical response (25-310 °C) and the nanoscale pattern of a homoepitaxial AlGaN/GaN high electron mobility transistor (HEMT) have been investigated at the micro and nanoscale. The low channel sheet resistance and the enhanced heat dissipation allow a highly conductive HEMT transistor (Ids > 1 A mm(-1)) to be defined (0.5 A mm(-1) at 300 °C). The vertical breakdown voltage has been determined to be ∼850 V with the vertical drain-bulk (or gate-bulk) current following the hopping mechanism, with an activation energy of 350 meV. The conductive atomic force microscopy nanoscale current pattern does not unequivocally follow the molecular beam epitaxy AlGaN/GaN morphology but it suggests that the FS-GaN substrate presents a series of preferential conductive spots (conductive patches). Both the estimated patches density and the apparent random distribution appear to correlate with the edge-pit dislocations observed via cathodoluminescence. The sub-surface edge-pit dislocations originating in the FS-GaN substrate result in barrier height inhomogeneity within the HEMT Schottky gate producing a subthreshold current.

18.
J Vet Intern Med ; 29(2): 607-13, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25711602

RESUMO

BACKGROUND: Reports of histiocytic sarcoma (HS) involving the central nervous system (CNS) are sparse and consist mainly of case reports describing 1-3 animals. OBJECTIVE: The objective of this study was to report the signalments, clinical signs, clinicopathologic and diagnostic imaging findings, treatment, and outcome of a series of dogs with HS and CNS involvement. ANIMALS: Nineteen dogs with HS examined at veterinary referral hospitals. METHODS: Retrospective case series. Medical records were reviewed and cases with a histopathological diagnosis of CNS HS were included in the study. Diagnostic imaging studies of the CNS were evaluated and histopathologic samples were reviewed to confirm the diagnosis. RESULTS: Retrievers and Pembroke Welsh Corgis were overrepresented in this cohort of dogs. Tumors involved the brain in 14 dogs and the spinal cord in 5. In 4 dogs, HS was part of a disseminated, multiorgan process whereas it appeared confined to the CNS in 15 dogs. Diagnostic imaging had variable appearances although extraaxial masses predominated in the brain. There was meningeal enhancement in all dogs that was often profound and remote from the primary mass lesion. Pleocytosis was present in all dogs with CSF evaluation. Median survival was 3 days. CONCLUSIONS AND CLINICAL IMPORTANCE: Breed predispositions appear to vary from reports of HS in other organ systems. Some unique imaging and clinicopathologic characteristics, particularly brain herniation, profound meningeal enhancement, and pleocytosis in combination with 1 or more mass lesions, might help to differentiate this neoplasm from others involving the CNS, although this requires further study.


Assuntos
Neoplasias do Sistema Nervoso Central/veterinária , Doenças do Cão/patologia , Sarcoma Histiocítico/veterinária , Animais , Neoplasias do Sistema Nervoso Central/patologia , Cães , Feminino , Sarcoma Histiocítico/patologia , Masculino , Estudos Retrospectivos
20.
Am J Community Psychol ; 51(1-2): 140-50, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22886284

RESUMO

Neighborhood is a social and geographic concept that plays an increasingly important role in research and practice that address disparities in health and well-being of populations. However, most studies of neighborhoods, as well as community initiatives geared toward neighborhood improvement, make simplifying assumptions about boundaries, often relying on census geography to operationalize the neighborhood units. This study used geographic information system (GIS) tools to gather and analyze neighborhood maps drawn by residents of low-income communities in 10 cities. The median resident map size was approximately 30 percent smaller than the median census tract, but 25 percent of residents viewed their neighborhood as quite small (less than one-fifth of the typical census tract). Multi-level modeling showed significant within context variation in perceived neighborhood scale. Longer term residents with higher education and income and who were more engaged in the neighborhood held more expansive views. But there were also contextual influences with higher density and mixed use areas associated with smaller perceived neighborhoods, and higher collective efficacy associated with larger neighborhood sizes. Artificially imposed neighborhood units may misrepresent resident experience, but GIS tools can be used to craft more authentic neighborhood definitions for research and practice.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Características de Residência , População Urbana , Adulto , Feminino , Sistemas de Informação Geográfica , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Estados Unidos
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