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1.
Nature ; 594(7864): 535-540, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34163056

RESUMEN

Night-migratory songbirds are remarkably proficient navigators1. Flying alone and often over great distances, they use various directional cues including, crucially, a light-dependent magnetic compass2,3. The mechanism of this compass has been suggested to rely on the quantum spin dynamics of photoinduced radical pairs in cryptochrome flavoproteins located in the retinas of the birds4-7. Here we show that the photochemistry of cryptochrome 4 (CRY4) from the night-migratory European robin (Erithacus rubecula) is magnetically sensitive in vitro, and more so than CRY4 from two non-migratory bird species, chicken (Gallus gallus) and pigeon (Columba livia). Site-specific mutations of ErCRY4 reveal the roles of four successive flavin-tryptophan radical pairs in generating magnetic field effects and in stabilizing potential signalling states in a way that could enable sensing and signalling functions to be independently optimized in night-migratory birds.


Asunto(s)
Migración Animal , Criptocromos/genética , Campos Magnéticos , Pájaros Cantores , Animales , Proteínas Aviares/genética , Pollos , Columbidae , Retina
2.
J Am Chem Soc ; 145(21): 11566-11578, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-37195086

RESUMEN

The primary step in the mechanism by which migratory birds sense the Earth's magnetic field is thought to be the light-induced formation of long-lived magnetically sensitive radical pairs within cryptochrome flavoproteins located in the birds' retinas. Blue-light absorption by the non-covalently bound flavin chromophore triggers sequential electron transfers along a chain of four tryptophan residues toward the photoexcited flavin. The recently demonstrated ability to express cryptochrome 4a from the night-migratory European robin (Erithacus rubecula), ErCry4a, and to replace each of the tryptophan residues by a redox-inactive phenylalanine offers the prospect of exploring the roles of the four tryptophans. Here, we use ultrafast transient absorption spectroscopy to compare wild type ErCry4a and four mutants having a phenylalanine at different positions in the chain. We find that each of the three tryptophan residues closest to the flavin adds a distinct relaxation component (time constants: 0.5, 30, and 150 ps) in the transient absorption data. The dynamics of the mutant containing a phenylalanine at the fourth position, furthest from the flavin, are very similar to those of wild type ErCry4a, except for a reduced concentration of long-lived radical pairs. The experimental results are evaluated and discussed in the framework of real-time quantum mechanical/molecular mechanical electron transfer simulations based on the density functional-based tight binding approach. This comparison between simulation results and experimental measurements provides a detailed microscopic insight into the sequential electron transfers along the tryptophan chain. Our results offer a route to the study of spin transport and dynamical spin correlations in flavoprotein radical pairs.


Asunto(s)
Criptocromos , Triptófano , Criptocromos/química , Triptófano/química , Electrones , Transporte de Electrón , Campos Magnéticos , Flavinas/metabolismo
3.
J Chem Phys ; 159(10)2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37694754

RESUMEN

Cryptochrome 4a (Cry4a) has been proposed as the sensor at the heart of the magnetic compass in migratory songbirds. Blue-light excitation of this protein produces magnetically sensitive flavin-tryptophan radical pairs whose properties suggest that Cry4a could indeed be suitable as a magnetoreceptor. Here, we use cavity ring-down spectroscopy to measure magnetic field effects on the kinetics of these radical pairs in modified Cry4a proteins from the migratory European robin and from nonmigratory pigeon and chicken. B1/2, a parameter that characterizes the magnetic field-dependence of the reactions, was found to be larger than expected on the basis of hyperfine interactions and to increase with the delay between pump and probe laser pulses. Semiclassical spin dynamics simulations show that this behavior is consistent with a singlet-triplet dephasing (STD) relaxation mechanism. Analysis of the experimental data gives dephasing rate constants, rSTD, in the range 3-6 × 107 s-1. A simple "toy" model due to Maeda, Miura, and Arai [Mol. Phys. 104, 1779-1788 (2006)] is used to shed light on the origin of the time-dependence and the nature of the STD mechanism. Under the conditions of the experiments, STD results in an exponential approach to spin equilibrium at a rate considerably slower than rSTD. We attribute the loss of singlet-triplet coherence to electron hopping between the second and third tryptophans of the electron transfer chain and comment on whether this process could explain differences in the magnetic sensitivity of robin, chicken, and pigeon Cry4a's.


Asunto(s)
Proteínas Aviares , Pollos , Criptocromos , Animales , Pollos/fisiología , Criptocromos/química , Criptocromos/fisiología , Campos Magnéticos , Migración Animal
4.
J Emerg Med ; 64(3): 328-337, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36863911

RESUMEN

BACKGROUND: Cardiopulmonary ultrasound (CPUS) is commonly used to assess cardiac function and preload status in patients with septic shock. However, the reliability of CPUS findings at the point of care is unknown. OBJECTIVE: To assess interrater reliability (IRR) of CPUS in patients with suspected septic shock between treating emergency physicians (EPs) vs emergency ultrasound (EUS) experts. METHODS: Single-center, prospective, observational cohort enrolling patients (n = 51) with hypotension and suspected infection. Treating EPs performed and interpreted CPUS for cardiac function parameters (left ventricular [LV] function and right ventricular [RV] function and size) and preload volume parameters (inferior vena cava [IVC] diameter and pulmonary B-lines). The primary outcome was IRR (assessed by Kappa values [κ] and intraclass correlation coefficient [ICC]) between EP and EUS-expert consensus. Secondary analyses examined the effects on IRR of operator experience, respiratory rate, and known difficult views on a Cardiology-performed echocardiogram. RESULTS: IRR was fair for LV function, κ = 0.37, 95% confidence interval (CI) 0.1-0.64; poor for RV function, κ = -0.05, 95% CI -0.6-0.5; moderate for RV size, κ = 0.47, 95% CI 0.07-0.88; and substantial for B-lines, κ = 0.73, 95% CI 0.51-0.95 and IVC size, ICC = 0.87, 95% CI 0.2-0.99. Involvement of ultrasound-trained faculty was associated with improved IRR of RV size (p = 0.002), but not other CPUS domains. CONCLUSIONS: Our study demonstrated high IRR for preload volume parameters (IVC size and presence of B-lines), but not for cardiac parameters (LV function and RV function and size) in patients presenting with concern for septic shock. Future research must focus on determining sonographer and patient-specific factors affecting CPUS interpretation in real-time.


Asunto(s)
Sistemas de Atención de Punto , Choque Séptico , Humanos , Servicio de Urgencia en Hospital , Estudios Prospectivos , Reproducibilidad de los Resultados
5.
Anal Chem ; 94(10): 4209-4217, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35231175

RESUMEN

The analysis of (trace) contaminants in environmental samples represents an important tool for exposure assessment and for the evaluation of potential risks to human health. Currently, mass spectrometric detection using triple quadrupole (TQMS) systems is the established method of choice. However, screening methods using high resolution mass spectrometry (HRMS) find increasing application as they provide advantages such as enhanced selectivity. A complex composition of environmental samples is known to have enormous effects on mass analyzers. The present work therefore compares the impact of a highly matrix-loaded sample material like house-dust on the performance of mass spectrometric detection of the emerging indoor contaminant group of mycotoxins by quadrupole time-of-flight (QTOF) and TQMS after ultrahigh-performance liquid chromatographic separation. Furthermore, the role of ionization efficiencies of different ion sources in instrument sensitivity was compared using an electrospray ionization source and a newly developed heated electrospray ion source (Bruker VIP-HESI) during QTOF experiments. Finally, it was evaluated whether an additional dimension of separation enables increased sensitivity in QTOF-HRMS detection by applying mycotoxins in house-dust to an (trapped) ion mobility spectrometry instrument. The sensitivity of the QTOF detection was positively influenced by the application of the VIP-HESI ion source, and overall HRMS instruments provided enhanced selectivity resulting in simplified data evaluation compared to the TQMS. However, all performed experiments revealed strong signal suppression due to matrix components. QTOF results showed more severe effects, enabling a more sensitive detection of mycotoxins in house-dust by applying TQMS detection.


Asunto(s)
Micotoxinas , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida , Polvo , Humanos , Espectrometría de Masas/métodos
6.
J Ultrasound Med ; 41(5): 1159-1167, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34378821

RESUMEN

OBJECTIVES: Use of point-of-care lung ultrasound (POC-LUS) has increased significantly in pediatrics yet it remains under-studied in the pediatric intensive care unit (PICU). No studies explicitly evaluate the reliability of POC-LUS artifact interpretation among critically ill children with acute respiratory failure (ARF) in the PICU. We thus designed this study to determine the inter-rater reliability of POC-LUS interpretation in pediatric ARF among pediatric intensivists trained in POC-LUS and an expert intensivist. METHODS: We compared the interpretation of lung sliding, pleural line characteristics, ultrasound artifacts, and POC-LUS diagnoses among pediatric intensivists and an expert intensivist in a cohort of children admitted to the PICU for ARF. Kappa statistics (k) adjusted for maximum attainable agreement (k/kmax ) were used to quantify chance-correct agreement between the pediatric intensivist and expert physician. RESULTS: We enrolled 88 patients, evaluating 3 zones per hemithorax (anterior, lateral, and posterior) for lung sliding, pleural line characteristics, ultrasound artifacts, and diagnosis. There was moderate agreement between the PICU intensivist and expert-derived diagnoses with 56% observed agreement (k/kmax  = 0.46, 95% confidence interval [CI] 0.31-0.65). Agreement in identification of lung sliding (k = 0.19, 95% CI -0.17 to 0.56) and pleural line characteristics (k = 0.24, 95% CI 0.08-0.40) was slight and fair, respectively, while agreement in the interpretation of ultrasound artifacts ranged from moderate to substantial. CONCLUSIONS: Evidence supporting the evaluation of neonatal and adult patients with POC-LUS should not be extrapolated to critically ill pediatric patients. This study adds to the evidence supporting use of POC-LUS in the PICU by demonstrating moderate agreement between PICU intensivist and expert-derived POC-LUS diagnoses.


Asunto(s)
Pediatría , Síndrome de Dificultad Respiratoria , Insuficiencia Respiratoria , Adulto , Niño , Enfermedad Crítica , Humanos , Recién Nacido , Pulmón/diagnóstico por imagen , Sistemas de Atención de Punto , Reproducibilidad de los Resultados , Insuficiencia Respiratoria/diagnóstico por imagen , Ultrasonografía
7.
Pediatr Crit Care Med ; 22(8): 722-732, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-33739956

RESUMEN

OBJECTIVES: Determine the sensitivity and specificity of point-of-care lung ultrasound in identifying the etiology of acute respiratory failure at admission to the PICU. DESIGN: Prospective observational study. SETTING: Tertiary PICU. PATIENTS: Children older than 37 weeks gestational age and less than or equal to 18 years old admitted to the PICU with acute respiratory failure from December 2018 to February 2020. INTERVENTION: Point-of-care lung ultrasound performed within 14 hours of admission to the PICU by physicians blinded to patient history and clinical course. Two physicians, blinded to all clinical information, independently interpreted the point-of-care lung ultrasound and then established a consensus diagnosis (ultrasound diagnosis). The ultrasound diagnosis was compared with an independent, standardized review of the medical record following hospital discharge (final diagnosis). MEASUREMENTS AND RESULTS: Eighty-eight patients were enrolled in the study. Forty-eight patients had a final diagnosis of bronchiolitis/viral pneumonitis (55%), 29 had pneumonia (33%), 10 had status asthmaticus (11%), and one was excluded because of an inability to differentiate the final diagnosis. Point-of-care lung ultrasound correctly identified the etiology of acute respiratory failure in 56% of patients (49/87; 95% CI, 46-66%). It identified bronchiolitis/viral pneumonitis with 44% sensitivity (95% CI, 0.31-0.58) and 74% specificity (95% CI, 0.59-0.85), pneumonia with 76% sensitivity (95% CI, 0.58-0.88) and 67% specificity (95% CI 0.54-0.78), and status asthmaticus with 60% sensitivity (95% CI, 0.31-0.83) and 88% specificity (95% CI, 0.79-0.94). CONCLUSIONS: In contrast to literature demonstrating high utility differentiating the cause of acute respiratory failure in adults, blinded point-of-care lung ultrasound demonstrates moderate sensitivity and specificity in identifying the etiology of pediatric acute respiratory failure at admission to the PICU among children with bronchiolitis, pneumonia, and status asthmaticus.


Asunto(s)
Sistemas de Atención de Punto , Insuficiencia Respiratoria , Niño , Humanos , Lactante , Unidades de Cuidado Intensivo Pediátrico , Pulmón/diagnóstico por imagen , Insuficiencia Respiratoria/diagnóstico por imagen , Insuficiencia Respiratoria/etiología , Ultrasonografía
8.
Genome Res ; 27(4): 524-532, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28373299

RESUMEN

Genomic analyses of cutaneous melanoma (CM) have yielded biological and therapeutic insights, but understanding of non-ultraviolet (UV)-derived CMs remains limited. Deeper analysis of acral lentiginous melanoma (ALM), a rare sun-shielded melanoma subtype associated with worse survival than CM, is needed to delineate non-UV oncogenic mechanisms. We thus performed comprehensive genomic and transcriptomic analysis of 34 ALM patients. Unlike CM, somatic alterations were dominated by structural variation and absence of UV-derived mutation signatures. Only 38% of patients demonstrated driver BRAF/NRAS/NF1 mutations. In contrast with CM, we observed PAK1 copy gains in 15% of patients, and somatic TERT translocations, copy gains, and missense and promoter mutations, or germline events, in 41% of patients. We further show that in vitro TERT inhibition has cytotoxic effects on primary ALM cells. These findings provide insight into the role of TERT in ALM tumorigenesis and reveal preliminary evidence that TERT inhibition represents a potential therapeutic strategy in ALM.


Asunto(s)
Aberraciones Cromosómicas , Melanoma/genética , Mutación , Neoplasias Cutáneas/genética , Telomerasa/genética , Adulto , Anciano , Anciano de 80 o más Años , Células Cultivadas , Femenino , GTP Fosfohidrolasas/genética , Genes de Neurofibromatosis 1 , Humanos , Masculino , Melanoma/patología , Proteínas de la Membrana/genética , Persona de Mediana Edad , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias Cutáneas/patología , Telomerasa/metabolismo , Transcriptoma , Quinasas p21 Activadas/genética
9.
J Am Acad Dermatol ; 82(4): 846-853, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31437542

RESUMEN

BACKGROUND: Inositol polyphosphate-5-phosphatase (INPP5A) has been shown to play a role in the progression of actinic keratosis to cutaneous squamous cell carcinoma (cSCC) and the progression of localized disease to metastatic disease. Currently, no cSCC biomarkers are able to risk stratify recurrent and metastatic disease. OBJECTIVE: To determine the prognostic value of INPP5A expression in cSCC recurrent and metastatic disease. METHODS: We conducted a multicenter, single-institutional, retrospective cohort study within the Mayo Clinic Health System on the use of immunohistochemical staining to examine cSCC INPP5A protein expression in primary tumors and recurrent and metastatic disease. Dermatologists and dermatopathologists were blinded to outcome. RESULTS: Low staining expression of INPP5A in recurrent and metastatic disease tumors was associated with poor overall survival (OS) (31.0 months for low versus 62.0 months for high expression; P = .0272). A composite risk score (calculated as score of primary tumor + score of recurrent or metastatic disease tumor, with tumors with high expression scoring a zero and low expression a 1, score range 0-2) of 0 was predictive of improved OS compared with a composite risk score of ≥1 (hazard ratio 0.42, 95% confidence interval 0.21-0.84; P = .0113). LIMITATIONS: This is a multicenter but single institution study of a white population. CONCLUSION: Loss of INPP5A expression predicts poor OS in recurrent and metastatic disease of cSCC.


Asunto(s)
Carcinoma de Células Escamosas/enzimología , Inositol Polifosfato 5-Fosfatasas/genética , Recurrencia Local de Neoplasia/enzimología , Neoplasias Cutáneas/enzimología , Anciano , Biomarcadores/análisis , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Progresión de la Enfermedad , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Inositol Polifosfato 5-Fosfatasas/análisis , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Pronóstico , Estudios Retrospectivos , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología
10.
Am J Emerg Med ; 38(12): 2653-2657, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33041124

RESUMEN

STUDY OBJECTIVE: To describe changes in cardiac function throughout the course of resuscitation of patients with suspected septic shock. METHODS: Prospective observational cohort study of Point-of-Care Transthoracic Echocardiograms (TTE) obtained in Emergency Department (ED) patients with a presumed infectious cause of hypotension within one hour of initiating IV fluid resuscitation. Findings of this pre-resuscitation TTE were compared to mid-resuscitation TTE (obtained upon disposition from the ED), and post-resuscitation TTE (obtained after admission to hospital). RESULTS: 22 enrolled patients had a second TTE available for comparison to the initial, pre-resuscitation TTE. 12 patients had a mid-resuscitation TTE and 16 patients had a post-resuscitation TTE. We observed a high incidence of changes on TTE during the clinical course of resuscitation (14/22 [64%]). Patients who developed LV or RV dysfunction during resuscitation were more likely to require vasopressor infusion and ICU admission (Spearman's coefficients [95% CI] of 0.68 [0.36-0.86] and 0.47 [0.04;0.75] respectively). Development of RV dysfunction alone was associated with increased use of positive pressure ventilation and vasopressor infusion (Spearman's coefficients [95% CI] of 0.43 [0;0.72] and 0.47 [0.05,0.75] respectively). CONCLUSIONS: Cardiac function changes assessed by TTE are common during the resuscitation of patients with septic shock. These changes likely reflect the underlying physiology of patients with septic shock and correlate with need for interventions and higher level of care. Further work is required to characterize these changes and to elucidate how to use these physiologic data to guide management.


Asunto(s)
Fluidoterapia , Resucitación , Choque Séptico/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Disfunción Ventricular Derecha/fisiopatología , Anciano , Estudios de Cohortes , Ecocardiografía , Servicio de Urgencia en Hospital , Femenino , Hospitalización , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Sistemas de Atención de Punto , Respiración con Presión Positiva/estadística & datos numéricos , Estudios Prospectivos , Choque Séptico/diagnóstico por imagen , Choque Séptico/terapia , Vasoconstrictores/uso terapéutico , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Derecha/diagnóstico por imagen
11.
Child Youth Serv Rev ; 1192020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33041412

RESUMEN

Limited rigorous research has been conducted to evaluate the impact of interventions designed to promote the successful transitions of young people exiting foster care. The current study builds on previous experimental evaluations of the My Life Model (MLM) for self-determination enhancement, which demonstrated effectiveness in improving educational and transition-to-adulthood outcomes for youth in foster care with disabilities, including those with mental health challenges. The model features one-on-one youth-directed coaching and near-peer mentoring to increase self-determination and goal achievement. The current study was the first to test the impact of the model with a diverse population-based cohort of youth aged 16.5-18.5 in foster care (N=293), including those with and without disabilities, on key model outcome indicators of self-determination and self-efficacy. This study also explored potential moderation by disability status, trauma symptoms, placement stability, and placement restrictiveness. Findings show that, compared to the randomized control group, the treatment group had greater post-intervention and one-year follow-up gains on several indicators of self-determination. Moderation analysis demonstrated no difference in intervention effectiveness for youth with or without disabilities, suggesting the universality of this approach. Findings also suggest that foster youth participants with low-to-average risks in terms of placement stability, placement restrictiveness, and traumatic stress levels seem to benefit most from the intervention, although youth who are at higher risk due to low placement stability, high placement restriction, and high traumatic stress still showed some benefit of participating in the intervention on some measures. My Life is one of only a few intervention models with experimental evidence of effectiveness with older youth in foster care. This validation study establishes that the approach has benefits for both youth with and without disabilities, as well as providing the first information available on the influence of critical barriers facing many youth in care.

12.
J Am Acad Dermatol ; 80(3): 626-632.e1, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30359624

RESUMEN

BACKGROUND: Inositol polyphosphate 5-phosphatase (INPP5A) has been shown to play a role in development and progression of cutaneous squamous cell carcinoma (cSCC). The goal of the current study was to explore the prognostic value of INPP5A expression in cSCC. METHODS: A total of 189 cases of actinic keratosis and SCC in 174 patients were identified; clinical and outcome data were abstracted, histopathology was rereviewed, and immunohistochemical staining and interpretation was performed for INPP5A. RESULTS: The majority of tumors (89.4%) had an INPP5A score of 2 or 3. No patients had complete loss of INPP5A. Tumors with an INPP5A score of 1 were more likely to be intermediate- to high-risk tumors (Brigham and Women's Hospital stage ≥T2a 85.0% vs 23.7% [P < .0001]) characterized by a larger diameter (2.4 cm vs 1.3 cm [P = .0004]), moderate-to-poor differentiation (86.7% vs 17.6% [P < .0001]), and perineural invasion (37.5% vs 5.3%, [P < .0001]). An INPP5A score of 1 was associated with a worse 3-year survival (a rate of 42.3% [hazard ratio, 2.81, P = .0006]) and a local metastasis rate of 48.0% (hazard ratio, 4.71; P < .0001). CONCLUSIONS: Low INPP5A scores are predictive of aggressive tumors and may be a useful adjunct to guide clinical management of cSCC.


Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/secundario , Inositol Polifosfato 5-Fosfatasas/metabolismo , Queratosis Actínica/metabolismo , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Femenino , Humanos , Queratosis Actínica/patología , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica , Metástasis de la Neoplasia , Nervios Periféricos/patología , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Carga Tumoral
13.
J Exp Bot ; 69(13): 3195-3210, 2018 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-29562265

RESUMEN

Drought and heat stress cause losses in wheat productivity in major growing regions worldwide, and both the occurrence and the severity of these events are likely to increase with global climate change. Water deficits and high temperatures frequently occur simultaneously at sensitive growth stages, reducing wheat yields by reducing grain number or weight. Although genetic variation and underlying quantitative trait loci for either individual stress are known, the combination of the two stresses has rarely been studied. Complex and often antagonistic physiology means that genetic loci underlying tolerance to the combined stress are likely to differ from those for drought or heat stress tolerance alone. Here, we review what is known of the physiological traits and genetic control of drought and heat tolerance in wheat and discuss potential physiological traits to study for combined tolerance. We further place this knowledge in the context of breeding for new, more tolerant varieties and discuss opportunities and constraints. We conclude that a fine control of water relations across the growing cycle will be beneficial for combined tolerance and might be achieved through fine management of spatial and temporal gas exchange.


Asunto(s)
Adaptación Biológica , Sequías , Termotolerancia , Triticum/fisiología , Adaptación Fisiológica , Estrés Fisiológico/genética , Termotolerancia/genética , Triticum/genética
14.
Curr Microbiol ; 75(3): 323-327, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29085995

RESUMEN

Using bacterial and fungal tag-encoded FLX-Titanium amplicon pyrosequencing, the microbiota of the fecal material of seven giraffes living in captivity at the Jacksonville Zoo and Gardens, Jacksonville, FL was investigated. In all samples, the most predominant bacterial phylum was the Firmicutes followed by Bacteroidetes. The most predominant fungi were members of the phylum Ascomycota followed by Neocallimastigomycota in five of seven samples. The reverse was true in the other two samples.


Asunto(s)
Bacterias/aislamiento & purificación , Biodiversidad , Heces/microbiología , Hongos/aislamiento & purificación , Microbiota , Animales , Bacterias/clasificación , Bacterias/genética , ADN Bacteriano/genética , ADN de Hongos/genética , Hongos/clasificación , Hongos/genética , Jirafas/microbiología , Filogenia , ARN Ribosómico 16S/genética
15.
Child Youth Serv Rev ; 86: 277-286, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29551847

RESUMEN

Research clearly documents the serious challenges and poor outcomes experienced by many young people exiting foster care, as well as compounded disparities for the high percentage of youth in care who are identified with disabilities and/or mental health challenges. However, very little research has been conducted to specify or validate effective models for improving the transition trajectories of youth exiting care. Evidence suggests the My Life self-determination enhancement model offers a promising approach for supporting youths' self-determined and positive transition to adulthood. The model includes youth-directed, experientially oriented coaching in the application of self-determination skills to achieve youth-identified transition goals, coupled with peer mentoring workshops that provide opportunities for learning, networking and fun. This in depth qualitative study of 10 youth who completed the My Life intervention focused on investigating coaching and mentoring elements and processes that youth participants identify as most important to their success, with the intention of informing the further development of youth-directed approaches to supporting young people who are transitioning to adulthood. Themes emerged around the centrality of youth self-direction, important processes in the coaching relationship, the essential value of experiential activities and self-determination skill development, and peer mentoring experiences that youth identified as fostering their success. Implications are discussed for research and practice in supporting youth exiting foster care.

16.
Blood ; 125(3): 483-91, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25395420

RESUMEN

To identify molecular targets that modify sensitivity to lenalidomide, we measured proliferation in multiple myeloma (MM) cells transfected with 27 968 small interfering RNAs in the presence of increasing concentrations of drug and identified 63 genes that enhance activity of lenalidomide upon silencing. Ribosomal protein S6 kinase (RPS6KA3 or RSK2) was the most potent sensitizer. Other notable gene targets included 5 RAB family members, 3 potassium channel proteins, and 2 peroxisome family members. Single genes of interest included I-κ-B kinase-α (CHUK), and a phosphorylation dependent transcription factor (CREB1), which associate with RSK2 to regulate several signaling pathways. RSK2 knockdown induced cytotoxicity across a panel of MM cell lines and consistently increased sensitivity to lenalidomide. Accordingly, 3 small molecular inhibitors of RSK2 demonstrated synergy with lenalidomide cytotoxicity in MM cells even in the presence of stromal contact. Both RSK2 knockdown and small molecule inhibition downregulate interferon regulatory factor 4 and MYC, and provides an explanation for the synergy between lenalidomide and RSK2 inhibition. Interestingly, RSK2 inhibition also sensitized MM cells to bortezomib, melphalan, and dexamethasone, but did not downregulate Ikaros or influence lenalidomide-mediated downregulation of tumor necrosis factor-α or increase lenalidomide-induced IL-2 upregulation. In summary, inhibition of RSK2 may prove a broadly useful adjunct to MM therapy.


Asunto(s)
Resistencia a Antineoplásicos/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Mieloma Múltiple/genética , Inhibidores de Proteínas Quinasas/farmacología , ARN Interferente Pequeño/aislamiento & purificación , Proteínas Quinasas S6 Ribosómicas 90-kDa/antagonistas & inhibidores , Talidomida/análogos & derivados , Inhibidores de la Angiogénesis/farmacología , Apoptosis/efectos de los fármacos , Western Blotting , Proliferación Celular/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Redes Reguladoras de Genes , Humanos , Factores Reguladores del Interferón/genética , Factores Reguladores del Interferón/metabolismo , Lenalidomida , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Mensajero/genética , ARN Interferente Pequeño/análisis , ARN Interferente Pequeño/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteínas Quinasas S6 Ribosómicas 90-kDa/genética , Talidomida/farmacología , Células Tumorales Cultivadas
17.
J Am Chem Soc ; 138(41): 13673-13692, 2016 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-27643954

RESUMEN

Activation of human telomerase reverse transcriptase (hTERT) is necessary for limitless replication in tumorigenesis. Whereas hTERT is transcriptionally silenced in normal cells, most tumor cells reactivate hTERT expression by alleviating transcriptional repression through diverse genetic and epigenetic mechanisms. Transcription-activating hTERT promoter mutations have been found to occur at high frequencies in multiple cancer types. These mutations have been shown to form new transcription factor binding sites that drive hTERT expression, but this model cannot fully account for differences in wild-type (WT) and mutant promoter activation and has not yet enabled a selective therapeutic strategy. Here, we demonstrate a novel mechanism by which promoter mutations activate hTERT transcription, which also sheds light on a unique therapeutic opportunity. Promoter mutations occur in a core promoter region that forms tertiary structures consisting of a pair of G-quadruplexes involved in transcriptional silencing. We show that promoter mutations exert a detrimental effect on the folding of one of these G-quadruplexes, resulting in a nonfunctional silencer element that alleviates transcriptional repression. We have also identified a small drug-like pharmacological chaperone (pharmacoperone) molecule, GTC365, that acts at an early step in the G-quadruplex folding pathway to redirect mutant promoter G-quadruplex misfolding, partially reinstate the correct folding pathway, and reduce hTERT activity through transcriptional repression. This transcription-mediated repression produces cancer cell death through multiple routes including both induction of apoptosis through inhibition of hTERT's role in regulating apoptosis-related proteins and induction of senescence by decreasing telomerase activity and telomere length. We demonstrate the selective therapeutic potential of this strategy in melanoma cells that overexpress hTERT.

18.
Blood ; 124(4): 536-45, 2014 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-24914135

RESUMEN

Cereblon (CRBN) mediates immunomodulatory drug (IMiD) action in multiple myeloma (MM). Using 2 different methodologies, we identified 244 CRBN binding proteins and established relevance to MM biology by changes in their abundance after exposure to lenalidomide. Proteins most reproducibly binding CRBN (>fourfold vs controls) included DDB1, CUL4A, IKZF1, KPNA2, LTF, PFKL, PRKAR2A, RANGAP1, and SHMT2. After lenalidomide treatment, the abundance of 46 CRBN binding proteins decreased. We focused attention on 2 of these-IKZF1 and IKZF3. IZKF expression is similar across all MM stages or subtypes; however, IKZF1 is substantially lower in 3 of 5 IMiD-resistant MM cell lines. The cell line (FR4) with the lowest IKZF1 levels also harbors a damaging mutation and a translocation that upregulates IRF4, an IKZF target. Clinical relevance of CRBN-binding proteins was demonstrated in 44 refractory MM patients treated with pomalidomide and dexamethasone therapy in whom low IKZF1 gene expression predicted lack of response (0/11 responses in the lowest expression quartile). CRBN, IKZF1, and KPNA2 levels also correlate with significant differences in overall survival. Our study identifies CRBN-binding proteins and demonstrates that in addition to CRBN, IKZF1, and KPNA2, expression can predict survival outcomes.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Proteínas Portadoras/metabolismo , Resistencia a Antineoplásicos , Factores Inmunológicos/farmacología , Mieloma Múltiple/metabolismo , Péptido Hidrolasas/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Antiinflamatorios/farmacología , Western Blotting , Ensayos Clínicos Fase II como Asunto , Dexametasona/farmacología , Citometría de Flujo , Estudios de Seguimiento , Humanos , Factor de Transcripción Ikaros/metabolismo , Inmunoprecipitación , Lenalidomida , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/mortalidad , Pronóstico , Estudios Prospectivos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Tasa de Supervivencia , Talidomida/análogos & derivados , Talidomida/farmacología , Células Tumorales Cultivadas , Ubiquitina-Proteína Ligasas , alfa Carioferinas/metabolismo
19.
Br J Haematol ; 168(4): 507-10, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25302557

RESUMEN

We constructed a multiple myeloma (MM)-specific gene panel for targeted sequencing and investigated 72 untreated high-risk (del17p) MM patients. Mutations were identified in 78% of the patients. While the majority of studied genes were mutated at similar frequency to published literature, the prevalence of TP53 mutation was increased (28%) and no mutations were found in FAM46C. This study provides a comprehensive insight into the mutational landscape of del17p high-risk MM. Additionally, our work demonstrates the practical use of a customized sequencing panel, as an easy, cheap and fast approach to characterize the mutational profile of MM.


Asunto(s)
ADN de Neoplasias/genética , Genes Relacionados con las Neoplasias , Mieloma Múltiple/genética , Análisis de Secuencia de ADN/métodos , Aberraciones Cromosómicas , Cromosomas Humanos Par 17/ultraestructura , Análisis Mutacional de ADN/métodos , Genes p53 , Humanos , Hibridación Fluorescente in Situ , Mutación , Riesgo
20.
Child Youth Serv Rev ; 56: 61-67, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-26240471

RESUMEN

While it has been well documented that racial and ethnic disparities exist for children of color in child welfare, the accuracy of the race and ethnicity information collected by agencies has not been examined, nor has the concordance of this information with youth self-report. This article addresses a major gap in the literature by examining: 1) the racial and ethnic self-identification of youth in foster care, and the rate of agreement with child welfare and school categorizations; 2) the level of concordance between different agencies (school and child welfare); and 3) the stability of racial and ethnic self-identification among youth in foster care over time. Results reveal that almost 1 in 5 youth change their racial identification over a one-year period, high rates of discordance exist between the youth self-report of Native American, Hispanic and multiracial youth and how agencies categorize them, and a greater tendency for the child welfare system to classify a youth as White, as compared to school and youth themselves. Information from the study could be used to guide agencies towards a more youth-centered and flexible approach in regards to identifying, reporting and affirming youth's evolving racial and ethnic identity.

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