RESUMO
BACKGROUND: As individuals with intellectual and developmental disabilities (I/DD) age, services often diminish, with many family caregivers experiencing challenges finding and navigating services. The purpose of this study was to examine the benefits of a state-wide family support project for ageing caregivers (50+) of adults with I/DD in accessing and using services. METHOD: A one-group pre-test-post-test design was used to determine if participation in the MI-OCEAN intervention grounded in the Family Quality of Life (FQOL) theory reduced ageing caregivers' (n = 82) perceptions of barriers to accessing, using and needing formal services. RESULTS: After participating in the study, there was a reduction in reported barriers to accessing services. There was also greater use and reduced need for 10 of the 23 listed formal services. CONCLUSIONS: Findings indicate that a peer-mediated intervention grounded in FQOL theory can be beneficial in empowering ageing caregivers by reducing perceived barriers to accessing services and increasing their use of advocacy and support services.
Assuntos
Pessoas com Deficiência , Deficiência Intelectual , Adulto , Criança , Humanos , Qualidade de Vida , Deficiências do Desenvolvimento/terapia , Envelhecimento , Cuidadores , FamíliaRESUMO
BACKGROUND: Both circadian disruption and timing of feeding have important roles in the development of metabolic disease. Despite growing acceptance that the timing of food consumption has long-term impact on metabolic homeostasis, little is known regarding the immediate influence on whole body metabolism, or the mechanisms involved. We aimed to examine the acute effects of time-of-day-dependent high fat feeding on whole body substrate metabolism and metabolic plasticity, and to determine the potential contribution of the adipocyte circadian clock. METHODS: Mice were fed a regimen of 4-h meal at the beginning and end of the dark (waking) cycle, separated by 4 h of fasting. Daily experimental conditions consisted of either an early very high fat or high fat (EVHF or EHF, 60 or 45% kcals from fat, respectively) or late (LVHF or LHF) meal, paired with a low fat (LF, 10% kcals from fat) meal. Metabolic parameters, glucose tolerance, body fat composition and weight were assessed. To determine the role of the adipocyte circadian clock, an aP2-CLOCK mutant (ACM) mouse model was used. RESULTS: Mice in the EVHF or EHF groups showed a 13.2 or 8.84 higher percentage of caloric intake from fat and had a 0.013 or 0.026 lower daily average respiratory exchange ratio, respectively, compared with mice eating the opposite feeding regime. Changes in glucose tolerance, body fat composition and weight were not significant at the end of the 9-day restricted feeding period. ACM mice did not exhibit different metabolic responses to the feeding regimes compared with wild-type littermates. Circadian clock disruption did not influence the short-term response to timed feeding. CONCLUSIONS: Both the total fat composition of diet and the timing of fat intake may differentially mediate the effect of timed feeding on substrate metabolism, but may not induce acute changes in metabolic flexibility.
Assuntos
Adipócitos/metabolismo , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Dieta Hiperlipídica , Metabolismo Energético/fisiologia , Comportamento Alimentar/fisiologia , Animais , Comportamento Animal , Glicemia/metabolismo , Peso Corporal , Modelos Animais de Doenças , Ingestão de Energia , Privação de Alimentos , Teste de Tolerância a Glucose , Masculino , Camundongos , Camundongos Transgênicos , Fatores de Tempo , Aumento de PesoRESUMO
A kidney-paired donation (KPD) pool consists of transplant candidates and their incompatible donors, along with nondirected donors (NDDs). In a match run, exchanges are arranged among pairs in the pool via cycles, as well as chains created from NDDs. A problem of importance is how to arrange cycles and chains to optimize the number of transplants. We outline and examine, through example and by simulation, four schemes for selecting potential matches in a realistic model of a KPD system; proposed schemes take account of probabilities that chosen transplants may not be completed as well as allowing for contingency plans when the optimal solution fails. Using data on candidate/donor pairs and NDDs from the Alliance for Paired Donation, the simulations extend over 8 match runs, with 30 pairs and 1 NDD added between each run. Schemes that incorporate uncertainties and fallbacks into the selection process yield substantially more transplants on average, increasing the number of transplants by as much as 40% compared to a standard selection scheme. The gain depends on the degree of uncertainty in the system. The proposed approaches can be easily implemented and provide substantial advantages over current KPD matching algorithms.
Assuntos
Algoritmos , Técnicas de Apoio para a Decisão , Seleção do Doador/métodos , Transplante de Rim , Doadores Vivos , Incerteza , Simulação por Computador , Seleção do Doador/organização & administração , Humanos , Modelos EstatísticosRESUMO
BACKGROUND AND OBJECTIVES: Donor plasmapheresis involves the removal of a weight-adjusted volume of plasma and the return of cellular components to the donor. Although plasma volume generally returns to normal, some residual effect on vital signs may be possible. This analysis was performed to determine the possible effects of plasmapheresis on blood pressure. MATERIALS AND METHODS: A 16-week study was conducted to evaluate the effects of plasma donations on cholesterol levels in healthy donors. From this study, the vital signs obtained prior to donation were analysed using statistical and dynamic analytical predictive models. RESULTS: Preliminary analyses revealed a change in systolic and diastolic blood pressure from the corresponding baseline values (Pearson Coefficient -0.44 and -0.47, respectively). Statistical models predicted a marked decrease in systolic and diastolic blood pressure following multiple donations in donors with baseline pressure in the Stage 2 hypertension range with less pronounced decreases predicted in Stage 1 donors. Little or no change in blood pressure was predicted in donors with baseline normal blood pressure or prehypertension. Dynamic models including time between donations supported these results and predicted a recovery period of about 14 days without donation in donors with Stage 2 baseline levels. CONCLUSIONS: Results suggest that systolic and diastolic blood pressure may be decreased following plasmapheresis used for plasma donations at intervals of <14 days in donors with high baseline blood pressure levels.
Assuntos
Doadores de Sangue , Pressão Sanguínea , Plasmaferese/efeitos adversos , Adulto , Humanos , Pessoa de Meia-Idade , Modelos CardiovascularesRESUMO
Pigmentation is a rapidly evolving trait that is under both natural and sexual selection in many organisms. In the quinaria group of Drosophila, nearly all of the 30 species have an abdomen that is light in color with distinct markings; D. tenebrosa is the exception in that it has a completely melanic abdomen with no visible markings. In this study, we use a combination of quantitative genetic and candidate gene approaches to investigate the genetic basis of abdominal pigmentation in D. tenebrosa. We find that abdominal pigmentation is invariant across wild-caught lines of D. tenebrosa and is not sexually dimorphic. Quantitative genetic mapping utilizing crosses between D. tenebrosa and the light-colored D. suboccidentalis indicates that two genomic regions together underlie abdominal pigmentation, including the X-chromosome and an autosome (Muller Element C/E). Further support for their central importance in pigmentation is that experimental introgression of one phenotype into the other species, in either direction, results in introgression of these two genomic regions. Finally, the expression of the X-linked gene yellow in the pupae exactly foreshadows the adult melanization pattern in the abdomen of both species, suggesting that changes in the regulation of yellow are important for the phenotypic divergence of D. tenebrosa from the rest of the quinaria group. These results contribute to a body of work that demonstrates how changes in expression of highly conserved genes can cause substantial phenotypic differences even between closely related species.
Assuntos
Drosophila/genética , Genoma , Pigmentação/genética , Abdome/anatomia & histologia , Animais , Ligação Genética , Genótipo , Dados de Sequência MolecularRESUMO
The presence of systematic noise in images in high-throughput microscopy experiments can significantly impact the accuracy of downstream results. Among the most common sources of systematic noise is non-homogeneous illumination across the image field. This often adds an unacceptable level of noise, obscures true quantitative differences and precludes biological experiments that rely on accurate fluorescence intensity measurements. In this paper, we seek to quantify the improvement in the quality of high-content screen readouts due to software-based illumination correction. We present a straightforward illumination correction pipeline that has been used by our group across many experiments. We test the pipeline on real-world high-throughput image sets and evaluate the performance of the pipeline at two levels: (a) Z'-factor to evaluate the effect of the image correction on a univariate readout, representative of a typical high-content screen, and (b) classification accuracy on phenotypic signatures derived from the images, representative of an experiment involving more complex data mining. We find that applying the proposed post-hoc correction method improves performance in both experiments, even when illumination correction has already been applied using software associated with the instrument. To facilitate the ready application and future development of illumination correction methods, we have made our complete test data sets as well as open-source image analysis pipelines publicly available. This software-based solution has the potential to improve outcomes for a wide-variety of image-based HTS experiments.
Assuntos
Ensaios de Triagem em Larga Escala/métodos , Iluminação/métodos , Microscopia/métodos , Estatística como Assunto/métodos , Ruído , SoftwareRESUMO
BACKGROUND: Viscoelastometric haemostatic assays (VHA) give rapid information on coagulation status, allowing individualised resuscitation. METHODS: This paper compares outcomes from two observational studies of postpartum haemorrhage (PPH) in the same institution, before and after practice changed from fixed ratio empirical transfusion of coagulation products with laboratory coagulation testing to VHA-guided fibrinogen replacement incorporated into an enhanced PPH care bundle. In both studies, all blood samples were taken near 1000â¯mL qualitative blood loss (QBL). In Study One, QBL started once PPH was identified, and resuscitation with coagulation blood products was empirical or based on laboratory tests of coagulation. In Study Two, QBL started at delivery and VHA was used to guide fibrinogen replacement if FIBTEM A5 was <12â¯mm (Claus fibrinogen ≤2â¯g/L) or to withhold coagulation products if FIBTEM A5 was >12â¯mm. RESULTS: Improved PPH outcomes were observed in Study Two, with rates of measured blood loss ≥2500â¯mL, ≥4 units red blood cell (RBC) transfusion, fresh frozen plasma transfusion and ≥8 units of any blood product transfusion all reduced (Pâ¯<â¯0.01). Clinically significant improvements occurred in women with fibrinogen ≤2â¯g/L at study entry, where the proportion of women who received ≥4 units RBC transfusion fell from 67% in Study One to 0% in Study Two (Pâ¯=â¯0.0007). CONCLUSIONS: These results suggest that use of VHA as part of an early bundle of PPH care targeting fibrinogen ≤2â¯g/L with fibrinogen concentrate reduces PPH progression. The greatest benefit was seen when fibrinogen levels were ≤2â¯g/L at first testing.
Assuntos
Fibrinogênio , Hemorragia Pós-Parto , Humanos , Feminino , Hemorragia Pós-Parto/terapia , Fibrinogênio/uso terapêutico , Estudos Prospectivos , Adulto , Gravidez , Resultado do Tratamento , Tromboelastografia/métodos , Hemostáticos/uso terapêutico , Transfusão de Sangue/métodos , Testes de Coagulação SanguíneaRESUMO
BACKGROUND: Considerable evidence suggests that the time of day at which calories are consumed markedly impacts body weight gain and adiposity. However, a precise quantification of energy balance parameters during controlled animal studies enforcing time-of-day-restricted feeding is currently lacking in the absence of direct human interaction. OBJECTIVE: The purpose of the present study was therefore to quantify the effects of restricted feeding during the light (sleep)-phase in a fully-automated, computer-controlled comprehensive laboratory animal monitoring system (CLAMS) designed to modulate food access in a time-of-day-dependent manner. Energy balance, gene expression (within metabolically relevant tissues), humoral factors and body weight were assessed. RESULTS: We report that relative to mice fed only during the dark (active)-phase, light (sleep)-phase fed mice: (1) consume a large meal upon initiation of food availability; (2) consume greater total calories per day; (3) exhibit a higher respiratory exchange ratio (indicative of decreased reliance on lipid/fatty acid oxidation); (4) exhibit tissue-specific alterations in the phases and amplitudes of circadian clock and metabolic genes in metabolically active tissues (greatest phase differences observed in the liver and diminution of amplitudes in epididymal fat, gastrocnemius muscle and heart); (5) exhibit diminished amplitude in humoral factor diurnal variations (for example, corticosterone); and (6) exhibit greater weight gain within 9 days of restricted feeding. CONCLUSIONS: Collectively, these data suggest that weight gain following light (sleep)-phase restricted feeding is associated with significant alterations in energy balance, as well as dyssynchrony between metabolically active organs.
Assuntos
Peso Corporal , Proteínas CLOCK/metabolismo , Ritmo Circadiano/fisiologia , Metabolismo Energético/fisiologia , Comportamento Alimentar/fisiologia , Luz , Animais , Biomarcadores/metabolismo , Glicemia/metabolismo , Relógios Circadianos , Corticosterona/metabolismo , Ingestão de Energia , Expressão Gênica , Masculino , Camundongos , Atividade Motora , Triglicerídeos/metabolismoRESUMO
BACKGROUND AND OBJECTIVES: LDL apheresis is used to treat patients with familial hypercholesterolaemia, and low-volume plasmapheresis for plasma donation may similarly lower cholesterol levels in some donors. This study was designed to assess the effect of plasmapheresis on total, LDL and HDL cholesterol levels in a plasma donor population. MATERIALS AND METHODS: This was a prospective, unblinded longitudinal cohort study in which a blood sample was obtained for analysis before each donation. Data from 663 donors were analysed using a multivariable repeated measures regression model with a general estimating equations approach with changes in cholesterol as the primary outcome measure. RESULTS: The model predicted a significant decrease in total and LDL cholesterol for both genders and all baseline cholesterol levels (P < 0.01). The greatest total cholesterol decreases (women, -46.8 mg/dL; men, -32.2 mg/dL) were associated with high baseline levels and 2-4 days between donations. Small but statistically significant increases (P ≤ 0.01) in HDL cholesterol were predicted for donors with low baseline levels. CONCLUSIONS: These results suggest that, in donors with elevated baseline cholesterol levels, total and LDL cholesterol levels may decrease during routine voluntary plasmapheresis.
Assuntos
Doadores de Sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Modelos Biológicos , Plasmaferese , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
GSK2245035, a small molecule Toll-like Receptor 7 (TLR7) agonist developed for immunomodulatory treatment for allergic airways disease, aimed to reduce Th2 and enhance Th1/Treg responses to aeroallergens via the local induction of type I interferons (IFNs). GSK2245035 demonstrated selectivity for potent release of type I IFNs compared to TNF-α and IL-6, with dose dependent increases in the interferon inducible chemokine, IP-10, in the nasal compartment. Implantation and parturition require pro-inflammatory processes including IFNs, Interferon Stimulated Genes, TNFα and IP-10 while pregnancy requires immune regulation to maintain maternal fetal immune tolerance, and recombinant type I IFNs induced abortions in monkeys. Due to its mechanism of action, GSK2245035 was studied at pharmacologically and clinically relevant doses in a monkey pregnancy model. Monkeys received 0, 3 or 30 ng/kg/week GSK2245035 intranasally once weekly, from Day 20 postcoitum through Day 63 postpartum. Although systemic IFN-α and IP-10 levels were approximately 14.8 or 40 -fold (respectively) above predose levels at 3 or 30 ng/kg/week, respectively, there were no effects on pregnancy and infant outcome. Non-adverse effects included increased incidence of nasal discharge, increased maternal body temperature at 30 ng/kg/week and dose-dependent increases in maternal IP-10 and IFN-α and decreased infant anti-KLH IgM and IgG titers following KLH immunization at ≥3 ng/kg/week, relative to controls. Potentially, lower IFN-α and IP-10 levels as well as once-weekly intranasal dosing vs daily subcutaneous or intramuscular dosing with recombinant type I IFNs could explain the lack of pregnancy effects; however, there was an undesired impact on offspring immune function.
Assuntos
Aborto Espontâneo/induzido quimicamente , Adenina/análogos & derivados , Asma/tratamento farmacológico , Piperidinas/efeitos adversos , Complicações na Gravidez/tratamento farmacológico , Receptor 7 Toll-Like/antagonistas & inibidores , Aborto Espontâneo/sangue , Aborto Espontâneo/imunologia , Adenina/efeitos adversos , Administração Intranasal , Animais , Asma/sangue , Asma/imunologia , Quimiocina CXCL10/sangue , Modelos Animais de Doenças , Feminino , Humanos , Interferon-alfa/sangue , Macaca fascicularis , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/imunologiaRESUMO
BACKGROUND: Excess caloric intake is strongly associated with the development of increased adiposity, glucose intolerance, insulin resistance, dyslipidemia, and hyperleptinemia (that is the cardiometabolic syndrome). Research efforts have focused attention primarily on the quality (that is nutritional content) and/or quantity of ingested calories as potential causes for diet-induced pathology. Despite growing acceptance that biological rhythms profoundly influence energy homeostasis, little is known regarding how the timing of nutrient ingestion influences development of common metabolic diseases. OBJECTIVE: To test the hypothesis that the time of day at which dietary fat is consumed significantly influences multiple cardiometabolic syndrome parameters. RESULTS: We report that mice fed either low- or high-fat diets in a contiguous manner during the 12 h awake/active period adjust both food intake and energy expenditure appropriately, such that metabolic parameters are maintained within a normal physiologic range. In contrast, fluctuation in dietary composition during the active period (as occurs in human beings) markedly influences whole body metabolic homeostasis. Mice fed a high-fat meal at the beginning of the active period retain metabolic flexibility in response to dietary challenges later in the active period (as revealed by indirect calorimetry). Conversely, consumption of high-fat meal at the end of the active phase leads to increased weight gain, adiposity, glucose intolerance, hyperinsulinemia, hypertriglyceridemia, and hyperleptinemia (that is cardiometabolic syndrome) in mice. The latter perturbations in energy/metabolic homeostasis are independent of daily total or fat-derived calories. CONCLUSIONS: The time of day at which carbohydrate versus fat is consumed markedly influences multiple cardiometabolic syndrome parameters.
Assuntos
Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Dislipidemias/fisiopatologia , Resistência à Insulina/fisiologia , Obesidade/fisiopatologia , Aumento de Peso/fisiologia , Animais , Dieta , Ingestão de Energia/fisiologia , Masculino , Camundongos , Periodicidade , Fatores de TempoRESUMO
BACKGROUND: Wolff-Parkinson-White syndrome (WPW) is a bypass re-entrant tachycardia that results from an abnormal connection between the atria and ventricles. Mutations in PRKAG2 have been described in patients with familial WPW syndrome and hypertrophic cardiomyopathy. Based on the role of bone morphogenetic protein (BMP) signalling in the development of annulus fibrosus in mice, it has been proposed that BMP signalling through the type 1a receptor and other downstream components may play a role in pre-excitation. METHODS AND RESULTS: Using the array comparative genomic hybridisation (CGH), we identified five individuals with non-recurrent deletions of 20p12.3. Four of these individuals had WPW syndrome with variable dysmorphisms and neurocognitive delay. With the exception of one maternally inherited deletion, all occurred de novo, and the smallest of these harboured a single gene, BMP2. In two individuals with additional features of Alagille syndrome, deletion of both JAG1 and BMP2 were identified. Deletion of this region has not been described as a copy number variant in the Database of Genomic Variants and has not been identified in 13 321 individuals from other cohort examined by array CGH in our laboratory. CONCLUSIONS: Our findings demonstrate a novel genomic disorder characterised by deletion of BMP2 with variable cognitive deficits and dysmorphic features and show that individuals bearing microdeletions in 20p12.3 often present with WPW syndrome.
Assuntos
Proteína Morfogenética Óssea 2/genética , Transtornos Cognitivos/genética , Deleção de Sequência , Síndrome de Wolff-Parkinson-White/genética , Adulto , Síndrome de Alagille/genética , Animais , Proteínas de Ligação ao Cálcio/genética , Hibridização Genômica Comparativa , Eletrocardiografia , Fácies , Feminino , Dosagem de Genes , Humanos , Lactente , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteína Jagged-1 , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Serrate-Jagged , Síndrome de Wolff-Parkinson-White/patologiaRESUMO
To determine the ability of antibodies to provide protection from Ebola viruses, monoclonal antibodies (mAbs) to the Ebola glycoprotein were generated and evaluated for efficacy. We identified several protective mAbs directed toward five unique epitopes on Ebola glycoprotein. One of the epitopes is conserved among all Ebola viruses that are known to be pathogenic for humans. Some protective mAbs were also effective therapeutically when administered to mice 2 days after exposure to lethal Ebola virus. The identification of protective mAbs has important implications for developing vaccines and therapies for Ebola virus.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Ebolavirus/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Proteínas do Envelope Viral/imunologia , Animais , Afinidade de Anticorpos , Antígenos Virais/imunologia , Ligação Competitiva , Proteínas do Sistema Complemento/imunologia , Ebolavirus/fisiologia , Epitopos/imunologia , Feminino , Doença pelo Vírus Ebola/terapia , Humanos , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Testes de Neutralização , Organismos Livres de Patógenos Específicos , Ensaio de Placa ViralRESUMO
Although several studies have examined the association between phase I/II enzyme polymorphisms and esophageal adenocarcinoma (EAC) and/or Barrett's esophagus (BE), their overall findings remain unclear. We performed a systematic review and meta-analysis to determine whether phase I/II polymorphisms are independent risk factors for either BE or EAC. We employed keyword searches in multiple databases to identify studies published before October 1, 2007. Single-nucleotide polymorphisms (SNPs) examined in > or =3 studies were meta-analyzed to obtain a pooled estimate of effect. Meta-analysis suggested the minor allele for GSTP1 Val(105) conveys modest excess risk (odds ratio [OR](BE)= 1.50, 95% confidence interval [CI] 1.16-1.95; OR(EAC)= 1.20, 95% CI 0.94-1.54). No excess risk was observed with GSTM1 null (OR(BE)= 0.77, 95% CI: 0.56-1.08; OR(EAC)= 1.08, 95% CI: 0.79-1.48), GSTT1 null (OR(BE)= 1.35, 95% CI: 0.91-2.01; OR(EAC)= 0.84, 95% CI: 0.48-1.49), or CYP1A Val(462) (OR(EAC)= 0.89, 95% CI: 0.40-1.97). Insufficient data existed to meta-analyze remaining SNPs. Our review identified GSTP1(Ile105Val) as a possible risk factor for BE and EAC in Caucasian males. No excess risk was observed for other phase I/II polymorphisms with sufficient data to meta-analyze. Additional studies are needed to determine if GSTP1 conveys excess risk in females or non-Caucasians and to evaluate other phase I/II polymorphisms.
Assuntos
Adenocarcinoma/epidemiologia , Esôfago de Barrett/epidemiologia , Esôfago de Barrett/genética , Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/genética , Predisposição Genética para Doença/epidemiologia , Polimorfismo de Nucleotídeo Único , Adenocarcinoma/enzimologia , Adenocarcinoma/genética , Esôfago de Barrett/enzimologia , Estudos de Casos e Controles , Neoplasias Esofágicas/enzimologia , Humanos , Fatores de RiscoRESUMO
Obesity is one of the most profound public health problems today, and simplistic explanations based on excessive nutritional consumption or lack of physical activity are inadequate to account for this dramatic and literal growth in our world population. Recent reports have suggested that disruptions in sleep patterns, often linked to our '24-h' lifestyle, are associated with increased body fat and altered metabolism, although the cause-effect relationship for these associations has yet to be elucidated. Abnormal sleep/wake patterns likely alter intracellular circadian clocks, which are molecular mechanisms that enable the cell/tissue/organism to anticipate diurnal variations in its environment. The environment may include circulating levels of nutrients (e.g. glucose, fatty acids and triglycerides) and various hormones (e.g. insulin, glucocorticoids). As such, alterations in this molecular mechanism, in particular within the adipocyte, likely induce metabolic changes that may potentiate disrupted metabolism, adipose accumulation and/or obesity. Although diurnal variations in adipokines and adipose tissue metabolism have been observed, little is known regarding the molecular mechanisms that influence these events.
Assuntos
Adipócitos/fisiologia , Ritmo Circadiano/fisiologia , Obesidade/fisiopatologia , Animais , Índice de Massa Corporal , Humanos , Redes e Vias Metabólicas/fisiologia , Obesidade/etiologia , Obesidade/genética , Sono/fisiologiaRESUMO
The success of proteomics hinges in part on the development of approaches able to map receptors on the surface of cells. One strategy to probe a cell surface for the presence of internalized markers is to make use of Shiga-like toxin 1 (SLT-1), a ribosome-inactivating protein that kills eukaryotic cells [1, 2]. SLT-1 binds to the glycolipid globotriaosylceramide [3, 4], which acts as a shuttle, allowing the toxin to be imported and routed near ribosomes. We investigated the use of SLT-1 as a structural template to create combinatorial libraries of toxin variants with altered receptor specificity. Since all SLT-1 variants retain their toxic function, this property served as a search engine enabling us to identify mutants from these libraries able to kill target cells expressing internalizable receptors. Random mutations were introduced in two discontinuous loop regions of the SLT-1 receptor binding subunit. Minimal searches from screening 600 bacterial colonies randomly picked from an SLT-1 library identified toxin mutants able to kill cell lines resistant to the wild-type toxin. One such mutant toxin was shown to bind to a new receptor on these cell lines by flow cytometry. Toxin libraries provide a strategy to delineate the spectrum of receptors on eukaryotic cells.
Assuntos
Técnicas de Química Combinatória , Toxina Shiga I/química , Sequência de Aminoácidos , Animais , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Células Eucarióticas , Citometria de Fluxo , Humanos , Modelos Moleculares , Sondas Moleculares , Toxina Shiga I/farmacologia , Células Tumorais Cultivadas , Células VeroRESUMO
A common feature of gene expression in all retroviruses is that unspliced, intron-containing RNA is exported to the cytoplasm despite the fact that cellular RNAs which contain introns are usually restricted to the nucleus. In complex retroviruses, the export of intron-containing RNA is mediated by specific viral regulatory proteins (e.g., human immunodeficiency virus type 1 [HIV-1] Rev) that bind to elements in the viral RNA. However, simpler retroviruses do not encode such regulatory proteins. Here we show that the genome of the simpler retrovirus Mason-Pfizer monkey virus (MPMV) contains an element that serves as an autonomous nuclear export signal for intron-containing RNA. This element is essential for MPMV replication; however, its function can be complemented by HIV-1 Rev and the Rev-responsive element. The element can also facilitate the export of cellular intron-containing RNA. These results suggest that the MPMV element mimics cellular RNA transport signals and mediates RNA export through interaction with endogenous cellular factors.
Assuntos
Íntrons , Vírus dos Macacos de Mason-Pfizer/genética , RNA Viral/genética , RNA Viral/metabolismo , Animais , Sequência de Bases , Transporte Biológico , Células COS , Núcleo Celular/virologia , Mapeamento Cromossômico , Citoplasma/virologia , Produtos do Gene env/biossíntese , Produtos do Gene gag/biossíntese , Produtos do Gene rev/genética , Produtos do Gene rev/fisiologia , HIV-1/genética , Humanos , Vírus dos Macacos de Mason-Pfizer/fisiologia , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Splicing de RNA , RNA Mensageiro/metabolismo , RNA Viral/química , Replicação Viral/genética , Produtos do Gene rev do Vírus da Imunodeficiência HumanaRESUMO
The myeloperoxidase (MPO) gene is transcribed specifically in immature myeloid cells and is regulated in part by a 414-bp proximal enhancer. Mutation of a core binding factor (CBF)-binding site at -288 decreased enhancer activity 30-fold in 32D cl3 myeloid cells cultured in granulocyte colony-stimulating factor (G-CSF). A novel functional analysis, linking the CBF-binding site to an enhancer deletion series, located at -147 an evolutionarily conserved c-Myb-binding site which was required for optimal enhancer activity and synergy with CBF in 32D cells. These sites cooperated in isolation and independent of a precise spacing. Deletional analysis carried out in the absence of the c-Myb-binding site at -147 located at -301 a second c-Myb-binding site which also synergized with CBF to activate the enhancer. A GA-rich region at -162 contributed to cooperation with CBF when the adjacent c-Myb-binding site was intact. Mutation of both c-Myb-binding sites in the context of the entire enhancer greatly impaired activation by endogenous CBF in 32D cells. Similarly, activation by c-Myb was impaired in constructs lacking the CBF-binding site. CBF and c-Myb were required for induction of MPO proximal enhancer activity when 32D cells differentiated in response to G-CSF. A fusion protein containing the Gal4 DNA-binding domain and the AML-1B activation domain, amino acids 216 to 480, activated transcription alone and cooperatively with c-Myb in nonmyeloid CV-1 cells. Determining how CBF and c-Myb synergize in myeloid cells might contribute to our understanding of leukemogenesis by the AML1-ETO, AML1-MDS1, CBFbeta-SMMHC, and v-Myb oncoproteins.
Assuntos
Proteínas de Ligação a DNA/farmacologia , Células-Tronco Hematopoéticas/metabolismo , Proteínas de Neoplasias , Peroxidase/genética , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/farmacologia , Animais , Sequência de Bases , Sítios de Ligação , Diferenciação Celular , Células Cultivadas , Fatores de Ligação ao Core , Elementos Facilitadores Genéticos , Ativação Enzimática , Camundongos , Dados de Sequência Molecular , Proteínas Proto-Oncogênicas c-myb , Transcrição GênicaRESUMO
Malignant mesothelioma (MM) is an aggressive malignancy, highly resistant to current medical and surgical therapies, whose tumor cells characteristically show a high level of aneuploidy and genomic instability. We tested our hypothesis that targeting chromosomal instability in MM would improve response to therapy. Thr/Tyr kinase (TTK)/monopolar spindle 1 kinase (Mps-1) is a kinase of the spindle assembly checkpoint that controls cell division and cell fate. CFI-402257 is a novel, selective inhibitor of Mps-1 with antineoplastic activity. We found that CFI-402257 suppresses MM growth. We found that Mps-1 is overexpressed in MM and that its expression correlates with poor patients' outcome. In vitro, CFI-402257-mediated inhibition of Mps-1 resulted in abrogation of the mitotic checkpoint, premature progression through mitosis, marked aneuploidy and mitotic catastrophe. In vivo, CFI-402257 reduced MM growth in an orthotopic, syngeneic model, when used as a single agent, and more so when used in combination with cisplatin+pemetrexed, the current standard of care. Our preclinical findings indicate that CFI-402257 is a promising novel therapeutic agent to improve the efficacy of the current chemotherapeutic regimens for MM patients.
Assuntos
Antineoplásicos/uso terapêutico , Proteínas de Ciclo Celular/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Mesotelioma/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirazóis/farmacologia , Pirimidinas/farmacologia , Animais , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Cisplatino/administração & dosagem , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Mesotelioma/genética , Mesotelioma/metabolismo , Mesotelioma Maligno , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Pemetrexede/administração & dosagem , Inibidores de Proteínas Quinases/administração & dosagem , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Análise de SobrevidaRESUMO
Reactive Fe(III) minerals can influence methane (CH4 ) emissions by inhibiting microbial methanogenesis or by stimulating anaerobic CH4 oxidation. The balance between Fe(III) reduction, methanogenesis, and CH4 oxidation in ferruginous Archean and Paleoproterozoic oceans would have controlled CH4 fluxes to the atmosphere, thereby regulating the capacity for CH4 to warm the early Earth under the Faint Young Sun. We studied CH4 and Fe cycling in anoxic incubations of ferruginous sediment from the ancient ocean analogue Lake Matano, Indonesia, over three successive transfers (500 days in total). Iron reduction, methanogenesis, CH4 oxidation, and microbial taxonomy were monitored in treatments amended with ferrihydrite or goethite. After three dilutions, Fe(III) reduction persisted only in bottles with ferrihydrite. Enhanced CH4 production was observed in the presence of goethite, highlighting the potential for reactive Fe(III) oxides to inhibit methanogenesis. Supplementing the media with hydrogen, nickel and selenium did not stimulate methanogenesis. There was limited evidence for Fe(III)-dependent CH4 oxidation, although some incubations displayed CH4 -stimulated Fe(III) reduction. 16S rRNA profiles continuously changed over the course of enrichment, with ultimate dominance of unclassified members of the order Desulfuromonadales in all treatments. Microbial diversity decreased markedly over the course of incubation, with subtle differences between ferrihydrite and goethite amendments. These results suggest that Fe(III) oxide mineralogy and availability of electron donors could have led to spatial separation of Fe(III)-reducing and methanogenic microbial communities in ferruginous marine sediments, potentially explaining the persistence of CH4 as a greenhouse gas throughout the first half of Earth history.