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1.
Mol Cell ; 69(2): 321-333.e3, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29351850

RESUMO

We have developed a highly parallel strategy, systematic gene-to-phenotype arrays (SGPAs), to comprehensively map the genetic landscape driving molecular phenotypes of interest. By this approach, a complete yeast genetic mutant array is crossed with fluorescent reporters and imaged on membranes at high density and contrast. Importantly, SGPA enables quantification of phenotypes that are not readily detectable in ordinary genetic analysis of cell fitness. We benchmark SGPA by examining two fundamental biological phenotypes: first, we explore glucose repression, in which SGPA identifies a requirement for the Mediator complex and a role for the CDK8/kinase module in regulating transcription. Second, we examine selective protein quality control, in which SGPA identifies most known quality control factors along with U34 tRNA modification, which acts independently of proteasomal degradation to limit misfolded protein production. Integration of SGPA with other fluorescent readouts will enable genetic dissection of a wide range of biological pathways and conditions.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Ensaios de Triagem em Larga Escala/métodos , Quinase 8 Dependente de Ciclina/genética , Redes Reguladoras de Genes , Genótipo , Complexo Mediador/genética , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
2.
BMC Nurs ; 23(1): 317, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720346

RESUMO

Although there is a growing literature on the use of telepresence robots in institutional dementia care settings, limited research focused on the perspectives of frontline staff members who deliver dementia care. Our objective was to understand staff perspectives on using telepresence robots to support residents with dementia and their families. Guided by the Consolidated Framework for Implementation Research, we conducted four focus groups and 11 semi-structured interviews across four long-term care (LTC) homes and one hospital in Canada. We included 22 interdisciplinary staff members (e.g., registered nurses, social workers, occupational therapists, recreational therapists) to understand their experiences with telepresence robots. Thematic analysis identified three key themes: 1) Staff Training and Support; 2) Robot Features; 3) Environmental dynamics for Implementation. Our results underscore the imperative of structural support at micro-, meso- and macro-levels for staff in dementia care settings to effectively implement technology. This study contributes to future research and practice by elucidating factors facilitating staff involvement in technology research, integrating staff voices into technology implementation planning, and devising strategies to provide structural support to staff, care teams, and care homes.

3.
J Sleep Res ; 31(5): e13558, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35102669

RESUMO

Sleep inertia is the brief period of performance impairment and reduced alertness experienced after waking, especially from slow-wave sleep. We assessed the efficacy of polychromatic short-wavelength-enriched light to improve vigilant attention, alertness and mood immediately after waking from slow-wave sleep at night. Twelve participants (six female, 23.3 ± 4.2 years) maintained an actigraphy-confirmed sleep schedule of 8.5 hr for 5 nights, and 5 hr for 1 night prior to an overnight laboratory visit. In the laboratory, participants were awakened from slow-wave sleep, and immediately exposed to either dim, red ambient light (control) or polychromatic short-wavelength-enriched light (light) for 1 hr in a randomized crossover design. They completed a 5-min Psychomotor Vigilance Task, the Karolinska Sleepiness Scale, and Visual Analogue Scales of mood at 2, 17, 32 and 47 min after waking. Following this testing period, lights were turned off and participants returned to sleep. They were awakened from their subsequent slow-wave sleep period and received the opposite condition. Compared with the control condition, participants exposed to light had fewer Psychomotor Vigilance Task lapses (χ2 [1] = 5.285, p = 0.022), reported feeling more alert (Karolinska Sleepiness Scale: F1,77  = 4.955, p = 0.029; Visual Analogue Scalealert : F1,77  = 8.226, p = 0.005), and reported improved mood (Visual Analogue Scalecheerful : F1,77  = 8.615, p = 0.004). There was no significant difference in sleep-onset latency between conditions following the testing period (t10  = 1.024, p = 0.330). Our results suggest that exposure to polychromatic short-wavelength-enriched light immediately after waking from slow-wave sleep at night may help improve vigilant attention, subjective alertness, and mood. Future studies should explore the potential mechanisms of this countermeasure and its efficacy in real-world environments.


Assuntos
Sono de Ondas Lentas , Atenção , Ritmo Circadiano , Feminino , Humanos , Luz , Desempenho Psicomotor , Sono , Sonolência , Vigília
4.
Brain Behav Immun ; 88: 559-565, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32330593

RESUMO

OBJECTIVE: Since the declaration of the coronavirus 2019 (COVID-19) outbreak as pandemic, there are reports on the increased prevalence of physical symptoms observed in the general population. We investigated the association between psychological outcomes and physical symptoms among healthcare workers. METHODS: Healthcare workers from 5 major hospitals, involved in the care for COVID-19 patients, in Singapore and India were invited to participate in a study by performing a self-administered questionnaire within the period of February 19 to April 17, 2020. Healthcare workers included doctors, nurses, allied healthcare workers, administrators, clerical staff and maintenance workers. This questionnaire collected information on demographics, medical history, symptom prevalence in the past month, Depression Anxiety Stress Scales (DASS-21) and the Impact of Events Scale-Revised (IES-R) instrument. The prevalence of physical symptoms displayed by healthcare workers and the associations between physical symptoms and psychological outcomes of depression, anxiety, stress, and post-traumatic stress disorder (PTSD) were evaluated. RESULTS: Out of the 906 healthcare workers who participated in the survey, 48 (5.3%) screened positive for moderate to very-severe depression, 79 (8.7%) for moderate to extremely-severe anxiety, 20 (2.2%) for moderate to extremely-severe stress, and 34 (3.8%) for moderate to severe levels of psychological distress. The commonest reported symptom was headache (32.3%), with a large number of participants (33.4%) reporting more than four symptoms. Participants who had experienced symptoms in the preceding month were more likely to be older, have pre-existing comorbidities and a positive screen for depression, anxiety, stress, and PTSD. After adjusting for age, gender and comorbidities, it was found that depression (OR 2.79, 95% CI 1.54-5.07, p = 0.001), anxiety (OR 2.18, 95% CI 1.36-3.48, p = 0.001), stress (OR 3.06, 95% CI 1.27-7.41, p = 0.13), and PTSD (OR 2.20, 95% CI 1.12-4.35, p = 0.023) remained significantly associated with the presence of physical symptoms experienced in the preceding month. Linear regression revealed that the presence of physical symptoms was associated with higher mean scores in the IES-R, DASS Anxiety, Stress and Depression subscales. CONCLUSIONS: Our study demonstrates a significant association between the prevalence of physical symptoms and psychological outcomes among healthcare workers during the COVID-19 outbreak. We postulate that this association may be bi-directional, and that timely psychological interventions for healthcare workers with physical symptoms should be considered once an infection has been excluded.


Assuntos
Ansiedade/epidemiologia , Infecções por Coronavirus , Depressão/epidemiologia , Pessoal de Saúde/estatística & dados numéricos , Pandemias , Pneumonia Viral , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Estresse Psicológico/epidemiologia , Adulto , Pessoal Técnico de Saúde/psicologia , Pessoal Técnico de Saúde/estatística & dados numéricos , Betacoronavirus , COVID-19 , Feminino , Cefaleia/epidemiologia , Pessoal de Saúde/psicologia , Humanos , Índia/epidemiologia , Internacionalidade , Letargia/epidemiologia , Masculino , Enfermeiras e Enfermeiros/psicologia , Enfermeiras e Enfermeiros/estatística & dados numéricos , Faringite/epidemiologia , Médicos/psicologia , Médicos/estatística & dados numéricos , Prevalência , SARS-CoV-2 , Singapura/epidemiologia , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Inquéritos e Questionários
5.
J Thromb Thrombolysis ; 50(4): 921-928, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32337652

RESUMO

Intravenously administered tissue plasminogen activator (IV-tPA), dose determined by patients' body-weight, remains the only approved drug treatment for acute ischemic stroke (AIS). Since a shorter onset-to-treatment time results in better functional outcome, treatment is often initiated according to the estimated or last-known body-weight of the patient. This approach may result in underdosing or overdosing of tPA. In this multicenter retrospective study, we evaluated the extent of error in tPA dosing in our AIS cohort and its impact on functional outcome and symptomatic intracranial hemorrhage (SICH). Consecutive AIS patients, receiving IV-tPA, dose determined by the estimated body-weight, at three tertiary centers between January and December 2017 were included. Collected data included information about demographics, cardiovascular risk factors, stroke subtype and National Institute of Health Stroke Scale (NIHSS) score. Estimated and measured body-weights were recorded. Modified Rankin scale (mRS) of 2 or more defined unfavorable outcome. The study included 150 patients. Median age was 64 -years (IQR 55-75) with male preponderance (67%) and median NIHSS score of 9 points (IQR 6-17). Mean measured weight of our study population was 58 (SD 13) kg. Median difference between actual and estimated body-weight was 3 kg (IQR 1.5-6). Difference was more than 10% in 35 (23.3%) patients. Good functional outcome (mRS 0-1) was achieved by 74 (49.3%) patients and 10 (6.8%) developed SICH. NIHSS (OR 1.288; 95% CI 1.157-1.435, p < 0.001) and large artery atherosclerosis (OR 5.878; 95% CI 1.929-17.910, p = 0.002) were independent predictors of unfavorable functional outcome. Our finding of the statistically insignificant 2.5-fold increase in poor outcomes among patients where the estimated and actual weight differed by more than 10% should be interpreted with caution due to the limited sample size. Significant difference occurs between estimated and actual body-weight in a considerable proportion of thrombolysed AIS patients. However, this discrepancy does not affect functional outcome or the risk of SICH.


Assuntos
Fibrinolíticos/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/administração & dosagem , Idoso , Peso Corporal , Relação Dose-Resposta a Droga , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento
6.
J Thromb Thrombolysis ; 50(3): 596-603, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32661758

RESUMO

The Coronavirus disease 2019 (COVID-19) pandemic is rapidly evolving and affecting healthcare systems across the world. Singapore has escalated its alert level to Disease Outbreak Response System Condition (DORSCON) Orange, signifying severe disease with community spread. We aimed to study the overall volume of AIS cases and the delivery of hyperacute stroke services during DORSCON Orange. This was a single-centre, observational cohort study performed at a comprehensive stroke centre responsible for AIS cases in the western region of Singapore, as well as providing care for COVID-19 patients. All AIS patients reviewed as an acute stroke activation in the Emergency Department (ED) from November 2019 to April 2020 were included. System processes timings, treatment and clinical outcome variables were collected. We studied 350 AIS activation patients admitted through the ED, 206 (58.9%) pre- and 144 during DORSCON Orange. Across the study period, number of stroke activations showed significant decline (p = 0.004, 95% CI 6.513 to - 2.287), as the number of COVID-19 cases increased exponentially, whilst proportion of activations receiving acute recanalization therapy remained stable (p = 0.519, 95% CI - 1.605 to 2.702). Amongst AIS patients that received acute recanalization therapy, early neurological outcomes in terms of change in median NIHSS at 24 h (-4 versus -4, p = 0.685) were largely similar between the pre- and during DORSCON orange periods. The number of stroke activations decreased while the proportion receiving acute recanalization therapy remained stable in the current COVID-19 pandemic in Singapore.


Assuntos
Assistência Integral à Saúde/organização & administração , Infecções por Coronavirus/terapia , Prestação Integrada de Cuidados de Saúde/organização & administração , Necessidades e Demandas de Serviços de Saúde/organização & administração , Pneumonia Viral/terapia , Acidente Vascular Cerebral/terapia , Idoso , COVID-19 , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Serviço Hospitalar de Emergência/organização & administração , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Equipe de Assistência ao Paciente/organização & administração , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Recuperação de Função Fisiológica , Encaminhamento e Consulta/organização & administração , Singapura/epidemiologia , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Fatores de Tempo , Tempo para o Tratamento/organização & administração , Resultado do Tratamento , Fluxo de Trabalho
7.
Int J Med Sci ; 16(4): 556-566, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31171907

RESUMO

Background: Clinical significance of germinal center B-cell (GCB) and non-GCB sub-categorization, expression of MYC, BCL2, BCL6, CD5 proteins and Epstein Barr virus encoded RNA (EBER) positivity in diffuse large B-cell lymphoma (DLBCL) remain controversial. Could these biomarkers accurately identify high risk DLBCL patients? Are MYC, BCL2 and BCL6 proteins expression feasible as baseline testing to predict c-Myc, BCL2 or BCL6 gene rearrangements? Aims: To investigate prognostic values of GCB/non-GCB sub-categorization, Double Protein Expression Lymphoma (DPL), Triple Protein Expression Lymphoma (TPL), positivity of CD5 protein and EBER in patients with DLBCL disease. To evaluate correlation between BCL2 , c-Myc and BCL6 gene rearrangements with BCL2, MYC and BCL6 proteins expression. Methods: Diagnostic tissue samples of 120 DLBCL patients between January 2012 to December 2013 from four major hospitals in Malaysia were selected. Samples were subjected to immunohistochemical staining, fluorescent in-situ hybridization (FISH) testing, and central pathological review. Pathological data were correlated with clinical characteristics and treatment outcome. Results: A total of 120 cases were analysed. Mean age of diagnosis was 54.1 years ± 14.6, 64 were males, 56 were females, mean follow up period was 25 months (ranged from 1 to 36 months). Of the 120 cases, 74.2% were non-GCB whereas 25.8% were GCB, 6.7% were EBER positive, 6.7% expressed CD5 protein, 13.3% were DPL and 40% were TPL. The prevalence of c-Myc, BCL2, BCL6 gene rearrangements were 5.8%, 5.8%, and 14.2%, respectively; and 1.6% were Double Hit Lymphoma (DHL). EBER positivity, DPL, TPL, c-Myc gene rearrangement, BCL2 gene rearrangement, extra copies of BCL2 gene and BCL6 gene rearrangement were associated with shorter median overall survival (P<0.05). IPI score was the significant determinants of median overall survival in DPL and TPL (P<0.05). CD5 protein expression and GCB/non-GCB sub-categorization did not affect treatment outcome (P>0.05). Overall, c-Myc, BCL2 and BCL6 gene rearrangements showed weak correlation with expression of MYC, BCL2 and BCL6 proteins (P>0.05). Fluorescent in situ hybridization is the preferred technique for prediction of treatment outcome in DLBCL patients. Conclusion: c-Myc, BCL2, and BCL6 gene rearrangements, EBER expression, DHL, TPL and IPI score are reliable risk stratification tools. MYC, BCL2 and BCL6 proteins expression are not applicable as baseline biomarkers to predict c-Myc, BCL2, and BCL6 gene rearrangements.


Assuntos
Infecções por Vírus Epstein-Barr/genética , Regulação Neoplásica da Expressão Gênica/genética , Linfoma Difuso de Grandes Células B/genética , Prognóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Antígenos CD5/genética , Intervalo Livre de Doença , Infecções por Vírus Epstein-Barr/patologia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Rearranjo Gênico/genética , Humanos , Hibridização in Situ Fluorescente , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/virologia , Malásia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-myc/genética , Serpinas/genética , Resultado do Tratamento , Adulto Jovem
8.
Adv Exp Med Biol ; 1185: 125-130, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31884600

RESUMO

Intravitreal (IVT) injection of ophthalmic therapeutics is the most widely used drug delivery route to the posterior segment of the eye. We employed this method to deliver our inorganic, catalytic antioxidant, cerium oxide nanoparticles (CeNPs), to rodent models of retinal degeneration. A single IVT of CeNPs delays disease progression. Even though we have shown that our synthesized CeNPs are retained in the retina for over a year, we still do not know which cell types in the retina preferentially take up these nanoparticles. In this study, we examined the temporal and spatial distribution of fluorescently labeled CeNPs in retinal sections after IVT. We detected elevated fluorescent signals in all the layers where retinal neurons and glia reside and retinal pigment epithelium (RPE) up to 90 days post injection. Additionally, we found that free fluorochrome accumulated in retinal vasculature instead of retinal cells. These data suggested that CeNP-conjugation mediated the targeting of the fluorochrome to retinal cells. We propose that CeNPs can be deployed as ophthalmic carriers to the retina.


Assuntos
Carbocianinas/análise , Nanopartículas , Retina/citologia , Animais , Cério , Fluorescência , Injeções Intravítreas , Camundongos , Neuroglia , Neurônios , Epitélio Pigmentado da Retina
9.
Anesth Analg ; 126(4): 1340-1348, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29049076

RESUMO

Long duty periods and overnight call shifts impair physicians' performance on measures of vigilance, psychomotor functioning, alertness, and mood. Anesthesiology residents typically work between 64 and 70 hours per week and are often required to work 24 hours or overnight shifts, sometimes taking call every third night. Mitigating the effects of sleep loss, circadian misalignment, and sleep inertia requires an understanding of the relationship among work schedules, fatigue, and job performance. This article reviews the current Accreditation Council for Graduate Medical Education guidelines for resident duty hours, examines how anesthesiologists' work schedules can affect job performance, and discusses the ramifications of overnight and prolonged duty hours on patient safety and resident well-being. We then propose countermeasures that have been implemented to mitigate the effects of fatigue and describe how training programs or practice groups who must work overnight can adapt these strategies for use in a hospital setting. Countermeasures include the use of scheduling interventions, strategic naps, microbreaks, caffeine use during overnight and extended shifts, and the use of bright lights in the clinical setting when possible or personal blue light devices when the room lights must be turned off. Although this review focuses primarily on anesthesiology residents in training, many of the mitigation strategies described here can be used effectively by physicians in practice.


Assuntos
Anestesiologia/educação , Anestesistas/educação , Competência Clínica , Educação de Pós-Graduação em Medicina/métodos , Internato e Residência , Fadiga Mental/prevenção & controle , Desempenho Profissional , Carga de Trabalho , Anestesistas/psicologia , Atenção , Currículo , Humanos , Fadiga Mental/diagnóstico , Fadiga Mental/etiologia , Fadiga Mental/psicologia , Desempenho Psicomotor , Fatores de Risco , Jornada de Trabalho em Turnos , Privação do Sono/psicologia , Fatores de Tempo , Tolerância ao Trabalho Programado
10.
Malays J Med Sci ; 25(4): 63-71, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30914848

RESUMO

OBJECTIVE: The Filipino ß°-deletion has been reported as a unique mutation in East Malaysia with a severe phenotype due to the complete absence of ß-globin chain synthesis. In this study, the haplotype patterns of the ß-globin gene cluster were used to relate the human genetic variation to this specific ß-thalassaemia mutation. METHODS: The 376 study subjects included 219 ß-thalassaemia major (ß-TM) patients with homozygous Filipino ß°-deletion and 157 carriers with heterozygous Filipino ß°-deletion from 10 government hospitals in different regions of Sabah. Genomic DNA was isolated from whole blood using silica membrane based DNA purification protocol. Polymerase chain reaction restriction fragment length polymorphism analysis (PCR-RFLP) was conducted on five markers within the ß-globin gene cluster to construct the haplotype patterns. RESULTS: Four haplotypes (Haplotype I-IV) were identified with Haplotype I as the predominant haplotype with the highest frequency of 0.98, followed by Haplotype II, III and Haplotype IV with 0.02. Haplotype I was strongly linked with the Filipino ß°-deletion among the indigenous population. CONCLUSION: Haplotype I as the predominant haplotype suggests the patients with the Filipino ß°-deletion in Sabah have a similar origin.

11.
Optom Vis Sci ; 94(1): 51-59, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27391532

RESUMO

PURPOSE: Diffuse tissue damage from impact or blast traumatic brain injury (TBI) degrades information processing throughout the brain, often resulting in impairments in sensorimotor function. We have developed an eye-movement assessment test, consisting of a simple, appropriately randomized, radial tracking task together with a broad set of oculometric measures that can be combined to yield a sensitive overall indicator of sensorimotor functional status. We show here that this multidimensional method can be used to detect and characterize sensorimotor deficits associated with TBI. METHODS: To compare dynamic visuomotor processing of TBI subjects (n = 34) with a separate control population (n = 41), we used the Comprehensive Oculometric Behavioral Response Assessment (COBRA) method (Liston & Stone, J Vision. 14:12, 2014) to quantify 10 performance metrics for each subject. Each TBI subject's set of oculometrics was then combined to compute a single TBI impairment vector whose magnitude we refer to as the impairment index. RESULTS: In our TBI population, several individual oculometrics were significantly degraded, including pursuit latency, initial pursuit acceleration, pursuit gain, catch-up saccade amplitude, proportion smooth tracking, and speed responsiveness. Furthermore, the TBI impairment index discriminated TBI subjects from controls with an 81% probability that increased with self-reported TBI severity; although the 9 subjects self-reporting "little-to-no" residual impairment were statistically indistinguishable from controls (58% probability), the remaining 25 subjects were easily detectable (91% probability). Given the demonstrated link between higher-order visual perception/cognition and eye movements, we interpret the observed TBI-related impairments as degradations in the speed, accuracy, and precision of information processing within cortical circuits supporting higher-order visual processing and sensorimotor control, not just low-level brainstem motor deficits. CONCLUSIONS: We conclude that multidimensional oculometric testing could be used as a sensitive screen for subtle neurological signs of subclinical neurological insults, to quantify functional impairment, to monitor deterioration or recovery, and to evaluate treatment efficacy.


Assuntos
Lesões Encefálicas Traumáticas/diagnóstico , Medições dos Movimentos Oculares , Movimentos Oculares/fisiologia , Transtornos Psicomotores/diagnóstico , Córtex Visual/fisiologia , Adulto , Encéfalo/fisiopatologia , Lesões Encefálicas Traumáticas/fisiopatologia , Cognição/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Psicomotores/fisiopatologia , Adulto Jovem
13.
Appl Environ Microbiol ; 81(16): 5639-49, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26070672

RESUMO

Agar, a seaweed extract, has been the standard support matrix for microbial experiments for over a century. Recent developments in high-throughput genetic screens have created a need to reevaluate the suitability of agar for use as colony support, as modern robotic printing systems now routinely spot thousands of colonies within the area of a single microtiter plate. Identifying optimal biophysical, biochemical, and biological properties of the gel support matrix in these extreme experimental conditions is instrumental to achieving the best possible reproducibility and sensitivity. Here we systematically evaluate a range of gelling agents by using the yeast Saccharomyces cerevisiae as a model microbe. We find that carrageenan and Phytagel have superior optical clarity and reduced autofluorescence, crucial for high-resolution imaging and fluorescent reporter screens. Nutrient choice and use of refined Noble agar or pure agarose reduce the effective dose of numerous selective drugs by >50%, potentially enabling large cost savings in genetic screens. Using thousands of mutant yeast strains to compare colony growth between substrates, we found no evidence of significant growth or nutrient biases between gel substrates, indicating that researchers could freely pick and choose the optimal gel for their respective application and experimental condition.


Assuntos
Ágar , Meios de Cultura/química , Géis , Técnicas Microbiológicas/métodos , Fenômenos Químicos , Ensaios de Triagem em Larga Escala , Saccharomyces cerevisiae/crescimento & desenvolvimento
14.
J Biol Chem ; 288(23): 16308-16320, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-23599433

RESUMO

Spermiogenesis is characterized by a profound morphological differentiation of the haploid spermatid into spermatozoa. The testis-specific serine/threonine kinases (TSSKs) comprise a family of post-meiotic kinases expressed in spermatids, are critical to spermiogenesis, and are required for male fertility in mammals. To explore the role of heat shock protein 90 (HSP90) in regulation of TSSKs, the stability and catalytic activity of epitope-tagged murine TSSKs were assessed in 293T and COS-7 cells. TSSK1, -2, -4, and -6 (small serine/threonine kinase) were all found to associate with HSP90, and pharmacological inhibition of HSP90 function using the highly specific drugs 17-AAG, SNX-5422, or NVP-AUY922 reduced TSSK protein levels in cells. The attenuation of HSP90 function abolished the catalytic activities of TSSK4 and -6 but did not significantly alter the specific activities of TSSK1 and -2. Inhibition of HSP90 resulted in increased TSSK ubiquitination and proteasomal degradation, indicating that HSP90 acts to control ubiquitin-mediated catabolism of the TSSKs. To study HSP90 and TSSKs in germ cells, a mouse primary spermatid culture model was developed and characterized. Using specific antibodies against murine TSSK2 and -6, it was demonstrated that HSP90 inhibition resulted in a marked decrease of the endogenous kinases in spermatids. Together, our findings demonstrate that HSP90 plays a broad and critical role in stabilization and activation of the TSSK family of protein kinases.


Assuntos
Fertilidade/fisiologia , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Espermátides/metabolismo , Animais , Células COS , Chlorocebus aethiops , Estabilidade Enzimática/efeitos dos fármacos , Estabilidade Enzimática/genética , Fertilidade/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/genética , Humanos , Masculino , Camundongos , Camundongos Mutantes , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteólise/efeitos dos fármacos , Espermátides/citologia , Ubiquitinação/efeitos dos fármacos , Ubiquitinação/fisiologia
15.
J Biol Chem ; 288(23): 16895-16904, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-23612964

RESUMO

Activating mutations in the αC-ß4 loop of the ERBB2 kinase domain, such as ERBB2(YVMA) and ERBB2(G776VC), have been identified in human lung cancers and found to drive tumor formation. Here we observe that the docking protein GAB1 is hyper-phosphorylated in carcinomas from transgenic mice and in cell lines expressing these ERBB2 cancer mutants. Using dominant negative GAB1 mutants lacking canonical tyrosine residues for SHP2 and PI3K interactions or lentiviral shRNA that targets GAB1, we demonstrate that GAB1 phosphorylation is required for ERBB2 mutant-induced cell signaling, cell transformation, and tumorigenesis. An enzyme kinetic analysis comparing ERBB2(YVMA) to wild type using physiologically relevant peptide substrates reveals that ERBB2(YVMA) kinase adopts a striking preference for GAB1 phosphorylation sites as evidenced by ∼150-fold increases in the specificity constants (kcat/Km) for several GAB1 peptides, and this change in substrate selectivity was predominantly attributed to the peptide binding affinities as reflected by the apparent Km values. Furthermore, we demonstrate that ERBB2(YVMA) phosphorylates GAB1 protein ∼70-fold faster than wild type ERBB2 in vitro. Notably, the mutation does not significantly alter the Km for ATP or sensitivity to lapatinib, suggesting that, unlike EGFR lung cancer mutants, the ATP binding cleft of the kinase is not significantly changed. Taken together, our results indicate that the acquired substrate preference for GAB1 is critical for the ERBB2 mutant-induced oncogenesis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Transformação Celular Neoplásica/metabolismo , Neoplasias Pulmonares/metabolismo , Mutação de Sentido Incorreto , Fosfoproteínas/metabolismo , Receptor ErbB-2/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Trifosfato de Adenosina/genética , Trifosfato de Adenosina/metabolismo , Substituição de Aminoácidos , Animais , Antineoplásicos/farmacologia , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Feminino , Humanos , Lapatinib , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Camundongos Transgênicos , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/genética , Fosforilação/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Quinazolinas/farmacologia , Receptor ErbB-2/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Especificidade por Substrato/efeitos dos fármacos , Especificidade por Substrato/genética
16.
J Hum Genet ; 59(3): 119-23, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24369358

RESUMO

Beta-thalassemia is one of the most prevalent inherited diseases and a public health problem in Malaysia. Malaysia is geographically divided into West and East Malaysia. In Sabah, a state in East Malaysia, there are over 1000 estimated cases of ß-thalassemia major patients. Accurate population frequency data of the molecular basis of ß-thalassemia major are needed for planning its control in the high-risk population of Sabah. Characterization of ß-globin gene defects was done in 252 transfusion dependent ß-thalassemia patients incorporating few PCR techniques. The study demonstrates that ß-thalassemia mutations inherited are ethnically dependent. It is important to note that 86.9% of transfusion-dependent ß-thalassemia major patients in Sabah were of the indigenous population and homozygous for a single mutation. The Filipino ß(0)-deletion was a unique mutation found in the indigenous population of Sabah. Mutations common in West Malaysia were found in 11 (4.3%) patients. Four rare mutations (Hb Monroe, CD 8/9, CD 123/124/125 and IVS I-2) were also found. This study is informative on the population genetics of ß-thalassemia major in Sabah.


Assuntos
Transfusão de Sangue , Talassemia beta/genética , Talassemia beta/terapia , Etnicidade/genética , Frequência do Gene/genética , Humanos , Malásia , Globinas beta/genética
17.
Biotechnol Appl Biochem ; 61(2): 184-92, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24033810

RESUMO

Bioreactor process changes can have a profound effect on the yield and quality of biotechnology products. Mannose-6-phosphate (M6P) glycan content and the enzymatic catalytic kinetic parameters are critical quality attributes (CQAs) of many therapeutic enzymes used to treat lysosomal storage diseases (LSDs). Here, we have evaluated the effect of adding butyrate to bioreactor production cultures of human recombinant ß-glucuronidase produced from CHO-K1 cells, with an emphasis on CQAs. The ß-glucuronidase produced in parallel bioreactors was quantified by capillary electrophoresis, the catalytic kinetic parameters were measured using steady-state analysis, and mannose-6-phosphorylation status was assessed using an M6P-specific single-chain antibody fragment. Using this approach, we found that butyrate treatment increased ß-glucuronidase production up to approximately threefold without significantly affecting the catalytic properties of the enzyme. However, M6P content in ß-glucuronidase was inversely correlated with the increased enzyme production induced by butyrate treatment. This assessment demonstrated that although butyrate dramatically increased ß-glucuronidase production in bioreactors, it adversely impacted the mannose-6-phosphorylation of this LSD therapeutic enzyme. This strategy may have utility in evaluating manufacturing process changes to improve therapeutic enzyme yields and CQAs.


Assuntos
Reatores Biológicos , Butiratos/farmacologia , Glucuronidase/biossíntese , Doenças por Armazenamento dos Lisossomos/enzimologia , Animais , Butiratos/química , Células CHO , Cricetinae , Cricetulus , Glucuronidase/uso terapêutico , Humanos , Doenças por Armazenamento dos Lisossomos/tratamento farmacológico , Doenças por Armazenamento dos Lisossomos/patologia , Manosefosfatos/química , Manosefosfatos/farmacologia , Fosforilação , Polissacarídeos/química
18.
Pediatr Crit Care Med ; 15(2): e56-65, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24196009

RESUMO

OBJECTIVES: To describe sleep quantity, sleep patterns, fatigue, and sleepiness for parents of critically ill hospitalized children. DESIGN: Prospective observational study. SETTING: Quaternary academic PICU. PARTICIPANTS: One hundred eighteen parents of 91 children recruited during their child's PICU stay. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: For 5 days and nights, parents wore an actigraph to determine objective sleep-wake times and reported sleep location, level of fatigue (Fatigue Visual Analogue Scale), and sleepiness (Stanford Sleepiness Scale). Mean amounts of nocturnal sleep were less than recommended for optimal health (398 min, fathers vs 422 min, mothers; p = 0.04). Parents woke frequently (7.8 wakes, fathers; 7.2 wakes, mothers) and spent over an hour awake at night (65 min, fathers; 60 min, mothers). On 130 nights (26%), parents slept less than 6 hours and 209 nights (44%) were evaluated as "worse" sleep than usual. Fifty-four parents (53%) experienced more than 30% difference in minutes of sleep between consecutive nights. Mean morning fatigue levels (41 mm, fathers vs 46 mm, mothers; p = 0.03) indicated clinically significant fatigue. Sleeping in a hotel, parent room, or residence was associated with 3.2 more wakes per night (95% CI, 0.61-5.78; p = 0.015) than sleeping in a hospital lounge or waiting room. CONCLUSIONS: We performed a prospective observational study of 118 parents of critically ill children using objective measures of sleep and validated scales to assess fatigue and sleepiness. We found that more than a quarter of nights met criteria for acute sleep deprivation, there was considerable variability in the amount of nocturnal sleep that individual participants slept on different nights, and sleep was fragmented with a large portion of the night spent awake. Future research should focus on interventions that improve parents' ability to return to sleep upon awakening and maintain regular sleep-wake schedules.


Assuntos
Estado Terminal , Fadiga/epidemiologia , Pais/psicologia , Transtornos do Sono-Vigília/epidemiologia , Actigrafia , Adulto , Criança , Pré-Escolar , Fadiga/etiologia , Feminino , Humanos , Unidades de Terapia Intensiva Pediátrica , Masculino , Estudos Prospectivos , Transtornos do Sono-Vigília/etiologia , Inquéritos e Questionários
19.
Adv Exp Med Biol ; 801: 821-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24664776

RESUMO

Cerium oxide (CeO2) nanoparticles, CeNPs or nanoceria are inorganic and possess catalytic antioxidant activity. They scavenge reactive oxygen species and act as an oxygen buffer. Their application in industry is well-established. However, their usage as bona fide antioxidants in biological systems has been recent and is quite revolutionary. Other reviews have documented nanoceria's protective effect in reducing oxidative stress in cell culture and in animal disease models that are associated with oxidative stress. We specifically have targeted CeNPs as ophthalmic therapeutics to slow the progression of retinal degeneration and as anti-angiogenic agents in rodent models. The radical scavenging activity of CeNPs is mainly due to the dramatic increase of surface area to volume ratio in these nanocrystalline structures. The parameters for CeNPs usage in industrial settings are decidedly not suitable for biological applications. In this short review, we report the pharmacokinetics, biodistribution, and toxicity evaluation of CeNPs when applied as ophthalmic therapeutic agents in an in vivo system. We highlight studies that examine how CeNPs behave in biological environments and how they interact with bio-macromolecules. We also discuss studies that examine the dynamic changes of the surface chemistry of CeNPs in physiological buffers. Finally, we raise a list of questions that we think ought to be answered for CeNPs to be considered the antioxidants of choice in medicine, specifically in the treatment of ocular diseases.


Assuntos
Antioxidantes/metabolismo , Cério/metabolismo , Nanopartículas/metabolismo , Degeneração Retiniana/tratamento farmacológico , Degeneração Retiniana/metabolismo , Animais , Antioxidantes/farmacologia , Cério/farmacologia , Humanos
20.
PLoS Genet ; 7(8): e1002249, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21901112

RESUMO

In plants and fungi, small RNAs silence gene expression in the nucleus by establishing repressive chromatin states. The role of endogenous small RNAs in metazoan nuclei is largely unknown. Here we show that endogenous small interfering RNAs (endo-siRNAs) direct Histone H3 Lysine 9 methylation (H3K9me) in Caenorhabditis elegans. In addition, we report the identification and characterization of nuclear RNAi defective (nrde)-1 and nrde-4. Endo-siRNA-driven H3K9me requires the nuclear RNAi pathway including the Argonaute (Ago) NRDE-3, the conserved nuclear RNAi factor NRDE-2, as well as NRDE-1 and NRDE-4. Small RNAs direct NRDE-1 to associate with the pre-mRNA and chromatin of genes, which have been targeted by RNAi. NRDE-3 and NRDE-2 are required for the association of NRDE-1 with pre-mRNA and chromatin. NRDE-4 is required for NRDE-1/chromatin association, but not NRDE-1/pre-mRNA association. These data establish that NRDE-1 is a novel pre-mRNA and chromatin-associating factor that links small RNAs to H3K9 methylation. In addition, these results demonstrate that endo-siRNAs direct chromatin modifications via the Nrde pathway in C. elegans.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Cromatina/genética , Proteínas Nucleares/metabolismo , Precursores de RNA/genética , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/metabolismo , Animais , Proteínas de Caenorhabditis elegans/genética , Cromatina/metabolismo , Metilação de DNA/genética , Histonas/genética , Histonas/metabolismo , Lisina/genética , Proteínas Nucleares/genética , Proteínas de Ligação a RNA/genética
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