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1.
PLoS Comput Biol ; 19(9): e1011511, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37769024

RESUMEN

Computer programming is a fundamental tool for life scientists, allowing them to carry out essential research tasks. However, despite various educational efforts, learning to write code can be a challenging endeavor for students and researchers in life-sciences disciplines. Recent advances in artificial intelligence have made it possible to translate human-language prompts to functional code, raising questions about whether these technologies can aid (or replace) life scientists' efforts to write code. Using 184 programming exercises from an introductory-bioinformatics course, we evaluated the extent to which one such tool-OpenAI's ChatGPT-could successfully complete programming tasks. ChatGPT solved 139 (75.5%) of the exercises on its first attempt. For the remaining exercises, we provided natural-language feedback to the model, prompting it to try different approaches. Within 7 or fewer attempts, ChatGPT solved 179 (97.3%) of the exercises. These findings have implications for life-sciences education and research. Instructors may need to adapt their pedagogical approaches and assessment techniques to account for these new capabilities that are available to the general public. For some programming tasks, researchers may be able to work in collaboration with machine-learning models to produce functional code.

2.
Hum Mol Genet ; 24(21): 6186-97, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26307082

RESUMEN

Immunotherapy, both active and passive, is increasingly recognized as a powerful approach to a wide range of diseases, including Alzheimer's and Parkinson's. Huntington's disease (HD), an autosomal dominant disorder triggered by misfolding of huntingtin (HTT) protein with an expanded polyglutamine tract, could also benefit from this approach. Individuals can be identified genetically at the earliest stages of disease, and there may be particular benefits to a therapy that can target peripheral tissues in addition to brain. In this active vaccination study, we first examined safety and immunogenicity for a broad series of peptide, protein and DNA plasmid immunization protocols, using fragment (R6/1), and knock-in (zQ175) models. No safety issues were found. The strongest and most uniform immune response was to a combination of three non-overlapping HTT Exon1 coded peptides, conjugated to KLH, delivered with alum adjuvant. An N586-82Q plasmid, delivered via gene gun, also showed ELISA responses, mainly in the zQ175 strain, but with more variability, and less robust responses in HD compared with wild-type controls. Transcriptome profiling of spleens from the triple peptide-immunized cohort showed substantial HD-specific differences including differential activation of genes associated with innate immune responses, absence of negative feedback control of gene expression by regulators, a temporal dysregulation of innate immune responses and transcriptional repression of genes associated with memory T cell responses. These studies highlight critical issues for immunotherapy and HD disease management in general.


Asunto(s)
Regulación de la Expresión Génica , Enfermedad de Huntington/genética , Enfermedad de Huntington/inmunología , Proteínas del Tejido Nervioso/inmunología , Proteínas Nucleares/inmunología , Vacunación , Secuencia de Aminoácidos , Animales , Femenino , Hemocianinas , Proteína Huntingtina , Enfermedad de Huntington/prevención & control , Memoria Inmunológica , Mediadores de Inflamación/metabolismo , Activación de Linfocitos , Masculino , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Fragmentos de Péptidos/inmunología , Linfocitos T/inmunología , Transcripción Genética , Regulación hacia Arriba
3.
J Bacteriol ; 196(3): 660-71, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24272778

RESUMEN

Escherichia coli AraC is a well-described transcription activator of genes involved in arabinose metabolism. Using complementary genomic approaches, chromatin immunoprecipitation (ChIP)-chip, and transcription profiling, we identify direct regulatory targets of AraC, including five novel target genes: ytfQ, ydeN, ydeM, ygeA, and polB. Strikingly, only ytfQ has an established connection to arabinose metabolism, suggesting that AraC has a broader function than previously described. We demonstrate arabinose-dependent repression of ydeNM by AraC, in contrast to the well-described arabinose-dependent activation of other target genes. We also demonstrate unexpected read-through of transcription at the Rho-independent terminators downstream of araD and araE, leading to significant increases in the expression of polB and ygeA, respectively. AraC is highly conserved in the related species Salmonella enterica. We use ChIP sequencing (ChIP-seq) and RNA sequencing (RNA-seq) to map the AraC regulon in S. enterica. A comparison of the E. coli and S. enterica AraC regulons, coupled with a bioinformatic analysis of other related species, reveals a conserved regulatory network across the family Enterobacteriaceae comprised of 10 genes associated with arabinose transport and metabolism.


Asunto(s)
Factor de Transcripción de AraC/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Salmonella enterica/metabolismo , Factor de Transcripción de AraC/genética , Arabinosa , Secuencia de Bases , Sitios de Unión , Mapeo Cromosómico , ADN Bacteriano , ARN Polimerasas Dirigidas por ADN , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica/fisiología , Genoma Bacteriano , Regulón , Salmonella enterica/genética
4.
J Environ Qual ; 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38816346

RESUMEN

The Lower Mississippi River Basin-Long-Term Agroecosystem Research Site (LMRB-LTAR) encompasses six states from Missouri to the Gulf of Mexico and is coordinated by the USDA-ARS National Sedimentation Laboratory, Oxford, MS. The overarching goal of LTAR is to assess regionally diverse and geographically scalable farming practices for enhanced sustainability of agroecosystem goods and services under changing environment and resource-use conditions. The LMRB-LTAR overall goal is to assess sustainable row crop agricultural production systems that integrate regional environmental and socioeconomic needs. Primary row crops in the region include soybeans, corn, cotton, rice, and sugarcane with crop rotations influenced by commodity crop price and other factors. The field-scale common experiment (CE) includes four row crop farms (26-101 ha) established in 2021 and 2023. Three fields are managed with alternative practices, including reduced tillage, cover crops, and automated prescription irrigation, and three fields are managed with prevailing farming practices, consisting of conventional tillage, no cover crop, and nonprescription irrigation. Treatment effects on crop productivity, soil quality, water use efficiency, water quality, and carbon storage are assessed. Research from the LMRB CE will deliver outcomes linked to overarching LTAR network goals, including innovative agricultural systems, strengthened partnerships, data management technologies, and precision environmental tools.

5.
Behav Res Ther ; 169: 104406, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37738844

RESUMEN

Recent studies have shown that fear conditioning experiments can be successfully conducted online. However, there is limited evidence that measures other than subjective ratings of threat expectancy can be collected, which means that online research may not be able to adequately replace laboratory experiments. In the current study, we conducted an online fear conditioning experiment consisting of habituation, acquisition, extinction and 48 h delayed extinction recall using ratings of threat expectancy and conditional stimulus pleasantness, and probe reaction time as outcome measures. The conditional stimuli were categories of words and a levels of processing manipulation explored whether words that were processed at a deeper level during extinction evoked smaller differential threat responses during extinction recall. Although the levels of processing manipulation did not produce a significant outcome, we found that extinction recall was successfully operationalised in our study. Reaction time indicated differential responding during both acquisition and extinction recall, and age of participants was correlated in one of two experiments with differential threat expectancy and reaction time, such that older participants showed better safety learning. The outcomes of this experiment provide multiple novel tools for researchers to explore fear conditioning, especially in an online environment.


Asunto(s)
Extinción Psicológica , Miedo , Humanos , Tiempo de Reacción , Extinción Psicológica/fisiología , Emociones/fisiología , Respuesta Galvánica de la Piel , Evaluación de Resultado en la Atención de Salud
6.
J Environ Qual ; 41(2): 564-81, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22370419

RESUMEN

Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath two stormwater infiltration basins in north-central Florida. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median, 41% silt+clay) exhibited decreases in dissolved oxygen from 3.8 to 0.1 mg L and decreases in nitrate nitrogen (NO-N) from 2.7 mg L to <0.016 mg L, followed by manganese and iron reduction, sulfate reduction, and methanogenesis. In contrast, beneath the basin with predominantly sandy soils (median, 2% silt+clay), aerobic conditions persisted from 2007 through 2009 (dissolved oxygen, 5.0-7.8 mg L), resulting in NO-N of 1.3 to 3.3 mg L in shallow groundwater. Enrichment of δN and δO of NO combined with water chemistry data indicates denitrification beneath the clayey basin and relatively conservative NO transport beneath the sandy basin. Soil-extractable NO-N was significantly lower and the copper-containing nitrite reductase gene density was significantly higher beneath the clayey basin. Differences in moisture retention capacity between fine- and coarse-textured soils resulted in median volumetric gas-phase contents of 0.04 beneath the clayey basin and 0.19 beneath the sandy basin, inhibiting surface/subsurface oxygen exchange beneath the clayey basin. Results can inform development of soil amendments to maintain elevated moisture content in shallow soils of stormwater infiltration basins, which can be incorporated in improved best management practices to mitigate NO impacts.


Asunto(s)
Carbono/química , Agua Subterránea/química , Nitrógeno/química , Suelo/química , Clima Tropical , Bacterias/aislamiento & purificación , Carbono/análisis , Florida , Minerales/análisis , Minerales/química , Nitratos/análisis , Nitratos/química , Nitrógeno/análisis , Oxígeno/análisis , Oxígeno/química , Calidad del Agua
7.
JSES Rev Rep Tech ; 2(1): 1-7, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37588294

RESUMEN

Background: Surgical management of massive irreparable rotator cuff tears remains controversial. Arthroscopic debridement (AD) has shown promising results especially in the population older than 65 years; however, there is no consensus on the benefits of various AD procedures. The aim of this systematic review was to evaluate the functional midterm to long-term outcomes in patients treated with AD in combination with subacromial decompression, biceps tenotomy, tuberoplasty, or bursectomy, without repair of the rotator cuff tear. Methods: A comprehensive search was performed in PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Cochrane databases for studies reporting clinical outcomes of AD of massive rotator cuff tears. Quality was determined using the Methodological Index for Nonrandomized Studies (MINORS) criteria by two independent reviewers. Pooled frequency-weighted means and standard deviations were calculated for patient-reported outcomes. Results: Sixteen articles containing 643 patients and 662 shoulders met the eligibility criteria. The mean age at the time of surgery was 65.9 ± 4.4 years with a mean follow-up period of 46.5 ± 27.3 months. There was notable clinically significant improvement across all patient-reported outcome scores postoperatively: Constant 70.4 ± 8.9 (P value = .06), University of California, Los Angeles ultrasonography 26.7 ± 5.2 (P value = .001), American Shoulder and Elbow Surgeons score 71.7 ± 2.1 (P value = .12), Disabilities of the Arm, Shoulder, and Hand score 35.3, and visual analog score 1.7 ± 0.9. Forty-nine patients (7%) required reoperation, which most commonly was a reverse total shoulder arthroplasty for the development of rotator cuff arthropathy. Conclusion: Arthroscopic debridement with a combination of subacromial decompression, tuberoplasty, subacromial bursectomy, and biceps tenotomy, for treatment of massive irreparable rotator cuff tears, produces good functional outcomes and improvement in pain at mid to long term follow up for the low-demand population greater than 65 years of age looking for pain relief over substantial increase in function.

8.
BMC Genomics ; 12: 169, 2011 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-21453490

RESUMEN

BACKGROUND: Foraminiferan protists, which are significant players in most marine ecosystems, are also genetic innovators, harboring unique modifications to proteins that make up the basic eukaryotic cell machinery. Despite their ecological and evolutionary importance, foraminiferan genomes are poorly understood due to the extreme sequence divergence of many genes and the difficulty of obtaining pure samples: exogenous DNA from ingested food or ecto/endo symbionts often vastly exceed the amount of "native" DNA, and foraminiferans cannot be cultured axenically. Few foraminiferal genes have been sequenced from genomic material, although partial sequences of coding regions have been determined by EST studies and mass spectroscopy. The lack of genomic data has impeded evolutionary and cell-biology studies and has also hindered our ability to test ecological hypotheses using genetic tools. RESULTS: 454 sequence analysis was performed on a library derived from whole genome amplification of microdissected nuclei of the Antarctic foraminiferan Astrammina rara. Xenogenomic sequence, which was shown not to be of eukaryotic origin, represented only 12% of the sample. The first foraminiferal examples of important classes of genes, such as tRNA genes, are reported, and we present evidence that sequences of mitochondrial origin have been translocated to the nucleus. The recovery of a 3' UTR and downstream sequence from an actin gene suggests that foraminiferal mRNA processing may have some unusual features. Finally, the presence of a co-purified bacterial genome in the library also permitted the first calculation of the size of a foraminiferal genome by molecular methods, and statistical analysis of sequence from different genomic sources indicates that low-complexity tracts of the genome may be endoreplicated in some stages of the foraminiferal life cycle. CONCLUSIONS: These data provide the first window into genomic organization and genetic control in these organisms, and also complement and expands upon information about foraminiferal genes based on EST projects. The genomic data obtained are informative for environmental and cell-biological studies, and will also be useful for efforts to understand relationships between foraminiferans and other protists.


Asunto(s)
Foraminíferos/genética , Genoma de Protozoos , Secuenciación de Nucleótidos de Alto Rendimiento , Secuencia de Aminoácidos , Secuencia de Bases , Mapeo Contig , ADN Mitocondrial/genética , ADN Protozoario/genética , Etiquetas de Secuencia Expresada , Biblioteca Genómica , Genómica/métodos , Datos de Secuencia Molecular , Análisis de Secuencia de ADN
9.
Respir Res ; 10: 86, 2009 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-19781081

RESUMEN

BACKGROUND: There is a need for new, noninvasive risk assessment tools for use in lung cancer population screening and prevention programs. METHODS: To investigate the technical feasibility of determining DNA methylation in exhaled breath condensate, we applied our previously-developed method for tag-adapted bisulfite genomic DNA sequencing (tBGS) for mapping of DNA methylation, and adapted it to exhaled breath condensate (EBC) from lung cancer cases and non-cancer controls. Promoter methylation patterns were analyzed in DAPK, RASSF1A and PAX5beta promoters in EBC samples from 54 individuals, comprised of 37 controls [current- (n = 19), former- (n = 10), and never-smokers (n = 8)] and 17 lung cancer cases [current- (n = 5), former- (n = 11), and never-smokers (n = 1)]. RESULTS: We found: (1) Wide inter-individual variability in methylation density and spatial distribution for DAPK, PAX5beta and RASSF1A. (2) Methylation patterns from paired exhaled breath condensate and mouth rinse specimens were completely divergent. (3) For smoking status, the methylation density of RASSF1A was statistically different (p = 0.0285); pair-wise comparisons showed that the former smokers had higher methylation density versus never smokers and current smokers (p = 0.019 and p = 0.031). For DAPK and PAX5beta, there was no such significant smoking-related difference. Underlying lung disease did not impact on methylation density for this geneset. (4) In case-control comparisons, CpG at -63 of DAPK promoter and +52 of PAX5beta promoter were significantly associated with lung cancer status (p = 0.0042 and 0.0093, respectively). After adjusting for multiple testing, both loci were of borderline significance (p(adj) = 0.054 and 0.031). (5) The DAPK gene had a regional methylation pattern with two blocks (1) approximately -215--113 and (2) -84-+26; while similar in block 1, there was a significant case-control difference in methylation density in block 2 (p = 0.045); (6)Tumor stage and histology did not impact on the methylation density among the cases. (7) The results of qMSP applied to EBC correlated with the corresponding tBGS sequencing map loci. CONCLUSION: Our results show that DNA methylation in exhaled breath condensate is detectable and is likely of lung origin. Suggestive correlations with smoking and lung cancer case-control status depend on individual gene and CpG site examined.


Asunto(s)
Biomarcadores de Tumor/análisis , Pruebas Respiratorias/métodos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Regiones Promotoras Genéticas/genética , Fumar/metabolismo , Metilación de ADN , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
10.
J Biochem Mol Toxicol ; 23(3): 222-32, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19526463

RESUMEN

Arsenite, an environmental cocontaminant of polycyclic aromatic hydrocarbons (PAHs), diminishes the PAH-mediated upregulation of human CYP1A1, the enzyme that bioactivates PAHs to carcinogenic metabolites. Mechanistically, while transcriptional downregulation contributes to these effects, a role for posttranslational regulation has been implicated but not proven. We hypothesize that arsenite induces heme oxygenase-1 (HO-1), which catabolizes CYP1A1 heme or cellular heme pools, thereby downregulating CYP1A1. Arsenite (5 microM), in HepG2 cells, induced HO-1 mRNA 7.4-fold over the 48 h observation period, and it upregulated HO-1 protein expression. Arsenite decreased the induction of CYP1A1 by a PAH, benzo[k]fluoranthene (BKF), by 50%; and transfection of HepG2 cells with siRNA targeting the human HO-1 gene, reduced the arsenite downregulation of BKF-induced CYP1A1 from 54% to 27%, relative to untransfected cells. Reconstituted HO-1 did not significantly catabolize CYP1A1 heme in vitro. Together these findings demonstrate that a posttranslational mechanism involving decreases in the cellular heme pool by arsenite-induced HO-1 may contribute to arsenite-mediated downregulation of CYP1A1.


Asunto(s)
Arsenitos/toxicidad , Citocromo P-450 CYP1A2/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Contaminantes Ambientales/toxicidad , Fluorenos/toxicidad , Hemo-Oxigenasa 1/metabolismo , Teratógenos/toxicidad , Línea Celular Tumoral , Activación Enzimática/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Humanos , Factores de Tiempo
12.
PLoS One ; 13(6): e0198154, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29874260

RESUMEN

A critical issue in transgene delivery studies is immune reactivity to the transgene- encoded protein and its impact on sustained gene expression. Here, we test the hypothesis that immunomodulation by rapamycin can decrease immune reactivity after intrathecal AAV9 delivery of a transgene (GFP) in non-human primates, resulting in sustained GFP expression in the CNS. We show that rapamycin treatment clearly reduced the overall immunogenicity of the AAV9/GFP vector by lowering GFP- and AAV9-specific antibody responses, and decreasing T cell responses including cytokine and cytolytic effector responses. Spinal cord GFP protein expression was sustained for twelve weeks, with no toxicity. Immune correlates of robust transgene expression include negligible GFP-specific CD4 and CD8 T cell responses, absence of GFP-specific IFN-γ producing T cells, and absence of GFP-specific cytotoxic T cells, which support the hypothesis that decreased T cell reactivity results in sustained transgene expression. These data strongly support the use of modest doses of rapamycin to modulate immune responses for intrathecal gene therapies, and potentially a much wider range of viral vector-based therapeutics.


Asunto(s)
Sistema Nervioso Central/metabolismo , Dependovirus/genética , Vectores Genéticos , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/inmunología , Inmunomodulación/fisiología , Primates/genética , Primates/inmunología , Animales , Animales Modificados Genéticamente , Autoantígenos/inmunología , Sistema Nervioso Central/inmunología , Dependovirus/inmunología , Expresión Génica , Técnicas de Transferencia de Gen , Vectores Genéticos/inmunología , Macaca fascicularis , Distribución Aleatoria , Transducción Genética , Transgenes/inmunología
13.
AIDS Patient Care STDS ; 21(9): 644-52, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17919091

RESUMEN

The duration of HIV infection is usually unknown for most patients entering into HIV care. Data on the frequency at which resistance mutations are detected in these patients are needed to support practical guidance on the use of resistance testing in this clinical situation. Furthermore, little is known about HIV subtype diversity in much of the United States. Therefore, we analyzed the prevalence of drug resistance mutations and nonsubtype B strains of HIV among antiretroviral-naïve individuals presenting for HIV care in New York State between September 2000 and January 2004. Sequences were obtained using a commercial HIV genotyping assay. Seventeen of 151 subjects (11.3%; 95% confidence interval 7.2%-17.3%) had at least one drug-resistance mutation, including 5 subjects with fewer than 200 CD4(+) T cells, indicative of advanced infection. Nucleoside reverse transcriptase inhibitor, non-nucleoside reverse transcriptase inhibitor, and protease inhibitor resistance mutations were detected in 6.6%, 5.3%, and 0.7% of subjects, respectively. Subjects from New York City-based clinics were less likely to have resistant virus than subjects from clinics elsewhere in New York State. Nonsubtype B strains of HIV were detected in 9 (6.0%) individuals and were associated with heterosexual contact. Two nonsubtype B strains from this cohort also carried drug-resistance mutations. These data indicate that drug-resistant virus is frequently detected in antiretroviral-naïve individuals entering HIV care in New York State. Furthermore, a diverse set of nonsubtype B strains were identified and evidence suggests that nonsubtype B strains, including those carrying drug-resistance mutations, are being transmitted in New York State.


Asunto(s)
Farmacorresistencia Viral/genética , Infecciones por VIH/genética , VIH/genética , ARN Viral/genética , Adulto , Anciano , Femenino , Genotipo , VIH/clasificación , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Inhibidores de la Proteasa del VIH/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , New York/epidemiología , Prevalencia , ARN Viral/sangre , Inhibidores de la Transcriptasa Inversa/uso terapéutico
14.
J Homosex ; 52(3-4): 151-66, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17594975

RESUMEN

This research project explores the relationship between social anxiety and appearance management behaviors (AMB), including both routine and non-routine, among gay and straight men and women. Prior research had found links between AMB and stress (Reilly & Rudd, 2002), stress and (perceived) discrimination (Lee, 1997; Savin-Williams, 1994), and sexual orientation and weight (Brand, Rothblum, & Solom, 1992). An argument is made that links stress with AMB using the foundation of Social Comparison Theory (Festinger, 1954) as a guide. Research questions investigated were: (1) Is there a correlation between stress and AMB; (2) Is there a significant difference between body mass indices of men and women of differing sexual orientations; (3) How do AMB differ between those with gay and straight orientations; and (4) How do AMB differ between men and women? Using a survey design, a questionnaire was posted on the Internet. Measures included the Rudd/Lennon Appearance Management Scale of Routine and Risky Behaviors and the Liebowitz Social Anxiety Scale. A total of 365 usable forms were completed. Results show that social anxiety is positively correlated with non-routine AMB, or behaviors that carry some risk. Gay and straight participants differed on the routine AMB they practiced. Men and women differed on the non-routine or risky AMB they practiced or would consider practicing. Implications are discussed and further research is suggested.


Asunto(s)
Ansiedad , Vestuario/psicología , Heterosexualidad/psicología , Homosexualidad Masculina/psicología , Estrés Psicológico , Adulto , Anciano , Ansiedad/etiología , Índice de Masa Corporal , Humanos , Masculino , Persona de Mediana Edad , Autoimagen , Percepción Social , Estrés Psicológico/etiología
15.
Appl Radiat Isot ; 64(6): 656-62, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16455264

RESUMEN

Monte Carlo modeling of a linear accelerator is the first and most important step in Monte Carlo dose calculations in radiotherapy. We developed a photon beam model for Varian 2100EX for dose calculation purposes using MCNP4C Monte Carlo code. Results of our modeling were in close agreement with our measurements. The effect of beam width on percentage depth doses and beam profiles was studied. Our results showed that electron beam width could be tuned using large field beam profile at the depth of maximum dose.


Asunto(s)
Método de Montecarlo , Aceleradores de Partículas , Fotones , Planificación de la Radioterapia Asistida por Computador , Dosificación Radioterapéutica
16.
J Biomol Tech ; 26(2): 37-44, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25802488

RESUMEN

In this paper, we describe a statistically based algorithm to quantify the uniformity of illumination in an optical light microscopy imaging system that outputs a single quality factor (QF) score. The importance of homogeneous field illumination in quantitative light microscopy is well understood and often checked. However, there is currently no standard automatic quantitative measure of the uniformity of the field illumination. Images from 89 different laser-scanning confocal microscopes (LSCMs), which were collected as part of an international study on microscope quality assessment, were used as a "training" set to build the algorithm. To validate the algorithm and verify its robustness, images from 33 additional microscopes, including LSCM and wide-field (WF) microscopes, were used. The statistical paradigm used for developing the quality scoring scale was a regression approach to supervised learning. Three intensity profiles across each image-2 corner-to-corner diagonals and a center horizontal-were used to generate pixel-intensity data. All of the lines passed through the center of the image. The intensity profile data then were converted into a single-field illumination QF score in the range of 0-100, with 0 having extreme variation, and therefore, essentially unusable, and 100 having no deviation, i.e., straight lines with a constant uniform intensity. Empirically, a QF ≥ 83 was determined to be the minimum acceptable value based on manufacturer acceptance tests and reasonably achievable values. This new QF is an invaluable metric to ascertain objectively and easily the uniformity of illumination quality, provide a traceable reference for monitoring field uniformity over time, and make a direct comparison among different microscopes. The QF can also be used as an indicator of system failure and the need for alignment or service of the instrument.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Iluminación , Microscopía Confocal/métodos , Imagen Óptica/métodos , Algoritmos , Simulación por Computador , Microscopía Confocal/instrumentación
17.
J Biomol Tech ; 26(2): 45-53, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25802489

RESUMEN

Identification of genetic factors that modify complex traits is often complicated by gene-environment interactions that contribute to the observed phenotype. In model systems, the phenotypic outcomes quantified are typically traits that maximize observed variance, which in turn, should maximize the detection of quantitative trait loci (QTL) in subsequent mapping studies. However, when the observed trait is dependent on multiple interacting factors, it can complicate genetic analysis, reducing the likelihood that the modifying mutation will ultimately be found. Alternatively, by focusing on intermediate phenotypes of a larger condition, we can reduce a model's complexity, which will, in turn, limit the number of QTL that contribute to variance. We used a novel method to follow angiogenesis in mice that reduces environmental variance by measuring endothelial cell growth from culture of isolated skin biopsies that varies depending on the genetic source of the tissue. This method, in combination with a backcross breeding strategy, is intended to reduce genetic complexity and limit the phenotypic effects to fewer modifier loci. We determined that our approach was an efficient means to generate recombinant progeny and used this cohort to map a novel s.c. angiogenesis QTL to proximal mouse chromosome (Chr.) 8 with suggestive QTL on Chr. 2 and 7. Global mRNA expression analysis of samples from parental reference strains revealed ß-defensins as potential candidate genes for future study.


Asunto(s)
Células Endoteliales/metabolismo , Neovascularización Fisiológica/genética , Sitios de Carácter Cuantitativo/genética , Piel/irrigación sanguínea , beta-Defensinas/metabolismo , Animales , Células Cultivadas , Mapeo Cromosómico , Cromosomas/genética , Ratones , ARN Mensajero/biosíntesis , Factor A de Crecimiento Endotelial Vascular/genética , beta-Defensinas/genética
18.
Diagn Microbiol Infect Dis ; 83(3): 312-8, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26272282

RESUMEN

Patients with infection, sepsis, severe sepsis, or septic shock were compared to each other and to healthy controls with regard to serum levels of biomarkers and clinical symptoms. Of the 15 biomarkers assayed, 9 were detectable in patients, and 4, in controls. Both proinflammatory and anti-inflammatory cytokines were detected in the patients. No single biomarker could differentiate the 3 septic levels of severity from each other; however, interleukin (IL) 1 receptor antagonist (IL-1ra) had the best sensitivity and specificity for differentiating sepsis and severe sepsis from septic shock. IL-6 was the only cytokine able to differentiate infected patients without signs of sepsis from those with sepsis. Although IL-1ra, IL-6, IL-8, and monocyte chemoattractant protein 1 could differentiate infection, sepsis, and severe sepsis from septic shock, the biomarkers could not differentiate sepsis from severe sepsis. The top scoring pair algorithm with clinical and biomarker analyses was able to correctly diagnose those with sepsis who will progress to a more severe state.


Asunto(s)
Biomarcadores/sangre , Sepsis/diagnóstico , Sepsis/patología , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Sensibilidad y Especificidad
19.
J Neuroimmunol ; 258(1-2): 51-60, 2013 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-23537887

RESUMEN

Autism spectrum disorders (ASD) are neurodevelopmental disorders with unknown etiology. BTBR-T(+)tf/J (BTBR) mice, a mouse strain with behaviors that resemble autism and with elevated levels of anti-brain antibodies (Abs), have enhanced activation of peripheral B cells and CD4(+) T cells and an expanded percentage of CD4(+) T cells expressing Vß6 chains. The CD4(+)CD25(+)Vß6(+) and Vß6-splenic cells of BTBR mice have elevated levels of IL-4, IFN-γ and IL-17, but there appears to be no preferential CD4(+) T subset skewing/polarization. The high level of IgG production by BTBR B cells was dependent on T cells from BTBR mice. The CD4(+) T cells of BTBR mice, especially those expressing Vß6 become spontaneously activated and expanded in an autoimmune-like manner, which occurred in both BTBR and B6 hosts that received an equal number of BTBR and B6 bone marrow cells. BTBR mice also have an elevated percentage of peripheral blood neutrophils, which may represent their elevated inflammatory state. B6 offspring derived from B6 dams that were gestationally injected with purified IgG from sera of BTBR mice, but not IgG of B6 mice, developed significantly impaired social behavior. Additionally, B6 offspring that developed in BTBR dams had impaired social behavior, while BTBR offspring that developed in B6 dams had improved social behavior. All of the immunological and behavioral parameters of BTBR mice were compared with those of B6 mice, which have relatively normal behaviors. The results indicate maternal Abs and possibly other maternal influences affect the social behavior of offspring.


Asunto(s)
Trastorno Autístico/inmunología , Autoinmunidad/inmunología , Efectos Tardíos de la Exposición Prenatal/inmunología , Conducta Social , Traslado Adoptivo , Animales , Autoanticuerpos/inmunología , Autoantígenos/sangre , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Inmunoglobulina G/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Embarazo , Resonancia por Plasmón de Superficie
20.
Virology ; 427(2): 135-43, 2012 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-22414343

RESUMEN

A coxsackievirus B4 induces acute pancreatitis with different outcomes. The study utilized a systems biology approach to identify molecular immune responses that differentiate between disease resolution and disease progression. The data establish a temporal pattern of host responses that differentiate the resolution of acute pancreatitis from the progression to chronic pancreatitis. A group of twenty-five genes exhibited characteristic expression profiles that were observed during the development of chronic pancreatitis but not during the resolution of disease. We postulate that the temporal dynamics of the twenty-five genes influence the development of pathogenic immune responses associated with chronic pancreatitis. Furthermore, a subset of eleven genes exhibited increased expression as viral titers waned. Of the eleven gene products, five are secreted molecules, TNF-α, IFN-γ, CXCL10, IL-10, and IL-22b, and represent novel potential therapeutic targets since they can be readily modulated with antibodies against the specific cytokine/chemokine or with antibodies against the corresponding receptors.


Asunto(s)
Infecciones por Coxsackievirus/virología , Enterovirus Humano B/inmunología , Pancreatitis Crónica/virología , Animales , Infecciones por Coxsackievirus/inmunología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/inmunología , Interleucina-10/genética , Interleucina-10/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Páncreas/patología , Páncreas/virología , Pancreatitis Crónica/metabolismo
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