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1.
Estud. pesqui. psicol. (Impr.) ; 18(4): 1087-1105, out.-dez. 2019. tab, ilus
Artigo em Português | LILACS, Index Psicologia - Periódicos técnico-científicos | ID: biblio-994974

RESUMO

Discorre-se sobre o desenvolvimento brasileiro da psicologia do trabalho e das organizações, com o foco na sua formação pós-graduada e produção científica. Inicia-se pela demarcação conceitual. Na seção subsequente, argumenta-se a favor da relação entre o crescimento e a diversificação da subárea e também a expansão da pós-graduação no Brasil. Segue um panorama das revisões de literatura nacionais, visando ressaltar a diversidade na prática de pesquisa. Finaliza-se com considerações sobre os desafios para alcançar níveis mais elevados de amadurecimento científico.(AU)


This article aims to describe the Brazilian development of work and organizational psychology, with a focus on its graduate training and scientific production. It begins by defining concepts. The following section argues in favor of the relationship between growth and diversification of the subarea and the expansion of graduate programs in Brazil. An overview of the national scientific reviews follows, in order to mark the diversity in research practices. Finally, the chapter discusses challenges to achieve higher levels of scientific maturity.(AU)


Se aborda el desarrollo brasileño de la psicología del trabajo y de las organizaciones, con el foco en su formación en el posgrado y producción científica. Se inicia por la demarcación conceptual. En la sección posterior, se argumenta a favor de la relación entre el crecimiento y la diversificación del sub-área y también la expansión del posgrado en el Brasil. Se propone un panorama de las revisiones de literatura nacionales, con vistas a resaltar la diversidad en la práctica de investigación. Se concluye con consideraciones sobre los desafíos para alcanzar niveles más elevados de madurez científica.(AU)


Assuntos
Psicologia , Educação de Pós-Graduação , Psicologia Aplicada , Pesquisa , Pesquisa Científica e Desenvolvimento Tecnológico , Métodos
3.
An Acad Bras Cienc ; 91(3): e20190676, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618414

RESUMO

The aim of this work was to optimize a maceration condition of cannabis (Cannabis sativa L.). A circumscribed central composite experimental design was applied in this work. Temperature and time were varied from 40-80 °C and 30-90 min, respectively. The three responses (i.e., extraction yield, cannabidiol content, and Δ9- tetrahydrocannabinol content) were predicted by computer software. The yield was high when cannabis was macerated using ethanol at high temperature and long duration time. While cannabidiol and Δ9- tetrahydrocannabinol content was high when macerating at a low heating temperature and short duration time. The optimal condition provided the simultaneous high of cannabidiol and Δ9- tetrahydrocannabinol content was 40 °C for 30 min. The prediction was accurate due to low percent error. This optimal condition could be used as a guide for maceration of cannabis to obtain the extract containing a high content of cannabidiol and Δ9- tetrahydrocannabinol.


Assuntos
Canabidiol/análise , Cannabis/química , Dronabinol/isolamento & purificação , Extratos Vegetais/análise , Cromatografia Líquida de Alta Pressão , Dronabinol/análise , Métodos , Temperatura Ambiente , Fatores de Tempo
5.
Saude e pesqui. (Impr.) ; 12(2): 367-375, maio/ago 2019. ilus
Artigo em Português | LILACS | ID: biblio-1016580

RESUMO

Este estudo tem como objetivo descrever as particularidades teórico-metodológicas e discutir as experiências vivenciadas no processo de pesquisa sobre fragilidade biológica e condições de saúde de idosos ribeirinhos amazônicos. A pesquisa descritiva, de abordagem qualiquantitativa, realizada em 19 ilhas do município de Cametá, Pará, envolveu 108 idosos e permitiu alcançar tanto as proposições diretas sobre os marcadores de fragilidade e de saúde multidimensional, quanto os aspectos subjetivos referentes às particularidades do contexto histórico-cultural. A trajetória percorrida pelos pesquisadores nesse desafio foi marcada, especialmente, por uma arreigada estruturação metodológica, direcionada ao contexto peculiar da pesquisa, desde a inserção ecológica dos pesquisadores, ponto-chave para a concretização do arcabouço metodológico e do período de coleta de dados até a elaboração das propostas norteadoras em saúde pública considerando, sobretudo, as particularidades dos modelos de cuidado vigentes nessas comunidades amazônicas.


Experiences lived during the research on the biological fragility and health conditions of elderly river people on the Amazon are described. Descriptive, qualitative and quantitative research in 19 islands in Cametá, Pará, Brazil, involved 108 elderly people and attained direct propositions on fragility markers, multidimensional health, and the subjective aspects on particulars within the historical and cultural context. Researchers´ trajectory was marked by strict methodology, foregrounded on the peculiar context of research ranging from the ecological insertion of the researchers, a key point for the materialization of the methodological design. It also took into account the period of data retrieval until the elaboration of proposals in public health, with special attention to care models in Amazon communities.


Assuntos
Idoso , Idoso de 80 Anos ou mais , Idoso Fragilizado , Ecossistema Amazônico , Características Culturais , Pesquisa Empírica , Métodos
6.
Kidney Blood Press Res ; 44(4): 848-857, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31242492

RESUMO

AIMS: The aim of this study was to develop a new method for detecting anti-phospholipase A2 receptor-IgG4 to improve the sensitivity and specificity in the diagnosis of idiopathic membranous nephropathy (IMN). METHODS: A highly sensitive quantitative assay was developed for the detection of serum anti-phospholipase A2 receptor-IgG4 with europium chelation by time-resolved fluoroimmunoassay (TRFIA), and a mouse anti-human IgG4 tracer was prepared using europium chelation for detection. The specificity and sensitivity of anti-phospholipase A2 receptor-IgG4 in the diagnosis of IMN were further assessed in patients with different kidney diseases. RESULTS: The detection limit of anti-PLA2R-IgG4 was 0.69 ng/mL. The measurement range of anti-PLA2R-IgG4 TRFIA was 0.69-2,500 ng/mL. Mean serum anti-PLA2R-IgG4 was 21.27 ± 15.15 ng/mL in 45 healthy volunteers, 31.08 ± 18.17 ng/mL in 29 IgA nephropathy patients, 49.10 ± 34.32 ng/mL in 8 lupus nephropathy patients, and 10,324.11 ± 17,030.40 ng/mL in 30 IMN patients. The anti-PLA2R-IgG4 cutoff concentration was >161.2 ng/mL with the sensitivity of 90.0% and specificity of 100% in the diagnosis of IMN. However, the cutoff for other kidney diseases was lower than 161.2 ng/mL. CONCLUSION: The serum anti-phospholipase A2 receptor IgG4 detected with the method developed in this study has higher sensitivity and higher specificity than total IgG in the diagnosis of IMN.


Assuntos
Glomerulonefrite Membranosa/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Receptores da Fosfolipase A2/imunologia , Feminino , Humanos , Imunoensaio/normas , Limite de Detecção , Masculino , Métodos
7.
Chemosphere ; 234: 373-378, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31228839

RESUMO

The diffusive gradients in thin films technique (DGT) was used for the determination of bioavailable mercury in urban soils, and results were compared to the mercury accumulation by Pisum sativum L. (pea) parts (leaf, root, stem, blossom, legume, and green seed). The total mercury concentration in soil samples was ranged between 0.084 and 0.326 mg kg-1. The soil solutions contained 0.15%-0.20% of mercury present in soils. In the soil solution, 2.21%-3.45% of mercury was available for DGT units. The highest mercury content was determined in the leaf and root of the pea plant, and the lowest in the consumable part of the pea plant (green seed). Mercury concentration in the parts of the pea plant increased over time, alongside the growth of the plant. The effect of acid precipitation on mercury bioavailability was statistically non-significant (p = 0.53). Significant and positive correlations were found between mercury flux into DGT unit, and mercury flux into the root (r = 0.989), leaf (r = 0.985), and stem (r = 0.904) of the pea plant. The obtained results suggest that the DGT method could be used for description of the uptake of mercury by pea plant parts in non-contaminated and slightly contaminated soils.


Assuntos
Mercúrio/farmacocinética , Ervilhas/metabolismo , Solo/química , Disponibilidade Biológica , Mercúrio/análise , Métodos , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Sementes/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/farmacocinética
8.
Clin Chim Acta ; 495: 422-428, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31082361

RESUMO

Fatty acids are fundamental as energy and structural source to the human cells. They are not usually found free in human circulation. Alteration in fatty acids metabolism is linked to diseases such as diabetes, preeclampsia, heart disease, and some infectious diseases. Increased levels of non-esterified fatty acids (NEFA) may cause cell dysfunction and lipotoxicity. Since physiologically fatty acids are transported bound to albumin, we propose here a simple and cheap test that consists of albumin isoelectric focusing determination to measure the potential systemic NEFA cytotoxicity. For validation of this method, albumin isoelectric focusing in 51 serum samples from 40 critically ill patients and 11 controls was compared with NEFA/albumin ratios measured by HPLC. We called this approach an albumin saturation test. This test may indicate to physicians the potential NEFA lipotoxicity guiding them throughout better patient management. The albumin saturation test can point out serum albumin-NEFA saturation through a cheap assay that could be performed by any care facility.


Assuntos
Ácidos Graxos/análise , Focalização Isoelétrica/métodos , Albumina Sérica/análise , Transporte Biológico , Estudos de Casos e Controles , Ácidos Graxos/toxicidade , Humanos , Focalização Isoelétrica/economia , Métodos
9.
Clin Chim Acta ; 495: 287-293, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31039337

RESUMO

BACKGROUND: Therapeutic drug monitoring of calcineurin inhibitor, tacrolimus (TAC), is routinely used in post-transplantation. Currently, measurement of calcineurin activity has been proposed as a promising clinical tool to evaluate efficacy and to optimize drug dosing. The main aim of our study was to develop a method to measure phosphatase calcineurin activity (CNA) in peripheral blood mononuclear cells (PBMCs) by ultra-high performance liquid chromatography-tandem mass spectrometry and to validate it following FDA and EMA guidelines. METHODS: This methodology is based on monitoring the Ca2+-dependent dephosphorylation of a phosphopeptide substrate. CNA was evaluated in 5 healthy volunteers and in 5 renal transplant patients receiving twice-daily formulation of TAC before drug intake. Moreover, we studied pharmacodynamic effect of TAC and blood concentrations of TAC in different drug dose intervals (0, 1, 3, 6 and 12 h). RESULTS: Our results showed linearity in the range 0.04-2.00 µM with a lower limit of quantification of 0.04 µM. Coefficients of variation and absolute relative biases were <4.3% and 10.3%, respectively. The mean recovery for peptide was 91.6 ±â€¯4.0%. Matrix effect study displayed ion suppression, and no carry-over and interferences were observed. There were no differences in CNA between healthy and TAC-treated patients. Furthermore, CNA showed maximum inhibition at 1 h after drug intake when TAC reached the highest blood concentration. CONCLUSIONS: This method improves the extraction phase of PBMCs and achieves faster determination compared to other techniques, bringing us closer to be applied in daily laboratory practice.


Assuntos
Calcineurina/metabolismo , Monitoramento de Medicamentos/métodos , Leucócitos Mononucleares/química , Tacrolimo/sangue , Adulto , Inibidores de Calcineurina/sangue , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Transplante de Rim , Masculino , Métodos , Espectrometria de Massas em Tandem , Fatores de Tempo , Transplantados
10.
Clin Chim Acta ; 495: 399-405, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31085187

RESUMO

BACKGROUND: LDL-C level can be measured by direct methods (LDL-CM) or calculated by Friedewald formula (LDL-CC). The aim of this study was to investigate the difference between LDL-CM and LDL-CC after a daily breakfast in Chinese patients with coronary heart disease (CHD). METHODS: Three hundred and three inpatients, including 203 CHD patients (CHD group) and 100 non-CHD controls (CON group), were enrolled in this study. Serum levels of blood lipid parameters, including LDL-CC and LDL-CM, at 0, 2 and 4 h (h) were monitored after a daily breakfast in all subjects. RESULTS: LDL-CM was significantly higher than LDL-CC in fasting state in each group and at 4 h postprandially in CHD group (P < .05). Postprandial LDL-CM and LDL-CC significantly decreased in each group (P < .05). Postprandial decline in LDL-CM was significantly greater than that of LDL-CC (P < .05). For CHD patients taking statins for ≥1 month before admission, non-fasting percent attainment of LDL-CM or LDL-CC was significantly higher than its fasting value, especially at 4 h (P < .05). The percent deviation of LDL-CM from 1.8 mmol/L at 4 h was significantly different from its fasting value. However, there was no significant difference in percent deviation of LDL-CC from 1.8 mmol/L between fasting and non-fasting states. CONCLUSIONS: It indicated that the clinical monitoring of non-fasting LDL-C level in CHD patients could be relatively complex, and the judgement may depend not only on the method to acquire LDL-C level, but also on the evaluation method.


Assuntos
Desjejum , LDL-Colesterol/sangue , Doença das Coronárias/sangue , Período Pós-Prandial , Idoso , Grupo com Ancestrais do Continente Asiático , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Lipídeos/sangue , Masculino , Métodos , Pessoa de Meia-Idade
11.
J Forensic Leg Med ; 65: 5-8, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31009839

RESUMO

Generally, the term complex suicide refers to a form of suicide in which more than one traumatic method is applied, simultaneously or consecutively, through multiple self-injurious actions using different methods and involving various bodily sites. A distinctive feature of complicated suicides is the failure of the initial attempt of the self-suppressive method that, nonetheless, results in death due to a subsequent accidental occurrence. In such cases, forensic pathologists and coroners are faced with the challenging differential diagnosis that generally includes homicide as well as suicide. We retrospectively analyzed autopsies from complex and complicated suicides registered at the Medicolegal bureau of Genoa (Italy) from 2006 to 2017. In the considered period, nineteen cases of complex suicides were identified and with only one case of a complicated suicide. In our series, the most frequent method of complex suicide was the cutting of the wrists followed by (unplanned) hanging for a total of eight cases (42.1%). The next most common cause (21% of cases) involved the jumping from a height after wrist cutting. In each case, it was necessary to meticulously examine the crime scene, reconstruct the chain of events, confirmed by the testimonies of relatives or eyewitnesses, review any medical history, particularly for psychiatric conditions, and perform a thorough autopsy so as to firmly establish the methods and causes of death.


Assuntos
Suicídio/estatística & dados numéricos , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Patologia Legal , Humanos , Itália/epidemiologia , Masculino , Métodos , Pessoa de Meia-Idade , Estudos Retrospectivos , Distribuição por Sexo , Ferimentos e Lesões/mortalidade
12.
Eur J Histochem ; 63(1)2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30920191

RESUMO

Transmission electron microscopy is the technique of choice to visualize the spatial relationships between nanoconstructs and cells and especially to monitor the uptake process of nanomaterials. It is therefore crucial that the cell surface be preserved in its integrity, to obtain reliable ultrastructural evidence: the plasmalemma represents the biological barrier the nanomaterials have to cross, and the mode of membrane-nanoconstruct interaction is responsible for the intracellular fate of the nanomaterials. In this paper, we describe a simple and inexpensive method to process cell monolayers for ultrastructural morphology and immunocytochemistry, ensuring consistent preservation of the cell surface and of the occurring interactions with nanoparticles of different chemical composition.


Assuntos
Membrana Celular/metabolismo , Microscopia Eletrônica de Transmissão/métodos , Nanopartículas/metabolismo , Manejo de Espécimes/métodos , Animais , Linhagem Celular , Humanos , Métodos , Camundongos , Nanoestruturas , Ratos
13.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1864(7): 1053-1060, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30853650

RESUMO

Lysophospholipid acyltransferases (LPLATs) incorporate a fatty acid into the hydroxyl group of lysophospholipids (LPLs) and are critical for determining the fatty acid composition of phospholipids. Previous studies have focused mainly on their molecular identification and their substrate specificity regarding the polar head groups and acyl-CoAs. However, little is known about the positional specificity of the hydroxyl group of the glycerol backbone (sn-2 or sn-1) at which LPLATs introduce a fatty acid. This is mainly due to the instability of LPLs used as an acceptor, especially for LPLs with a fatty acid at the sn-2 position of the glycerol backbone (sn-2-LPLs), which are essential for the enzymatic assay to determine the positional specificity. In this study, we established a method to determine the positional specificity of LPLAT by preparing stable sn-2-LPLs in combination with PLA2 digestion, and applied the method for determining the positional specificity of several LPLATs including LPCAT1, LYCAT and LPCAT3. We found that LPCAT1 introduced palmitic acid both at the sn-1 and sn-2 positions of palmitoyl-LPC, while LYCAT and LPCAT3 specifically introduced stearic acid at the sn-1 position of LPG and arachidonic acid at the sn-2 position of LPC, respectively. The present method for evaluating the positional specificity could also be used for biochemical characterization of other LPLATs.


Assuntos
Aciltransferases/metabolismo , Ácidos Graxos/metabolismo , Lisofosfolipídeos/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferase/metabolismo , Sítios de Ligação , Glicerol/metabolismo , Métodos , Ácido Palmítico/metabolismo , Ácidos Esteáricos/metabolismo , Especificidade por Substrato
14.
Blood Cells Mol Dis ; 76: 32-39, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30709626

RESUMO

The potential use of patient-specific induced pluripotent stem cells (hiPSCs) in the study and treatment of hematological diseases requires the setup of efficient and safe protocols for hiPSC generation. We aimed to adopt a reprogramming method for large-scale production of integration-free patient-specific hiPSC-lines in our stem cell processing laboratory, which supports a pediatric hematopoietic stem cell transplant unit located at a tertiary care children's hospital. We describe our 5-year experience in generation of hiPSC-lines from human bone marrow-derived mesenchymal stromal cells (BM-MSCs) using synthetic mRNAs encoding reprogramming factors. We generated hiPSC-lines from pediatric patients with ß-Thalassemia, Sickle Cell Anemia, Blackfan-Diamond Anemia, Severe Aplastic Anemia, DOCK8 Immunodeficiency and 1 healthy control. After optimization of the reprogramming procedure, average reprogramming efficiency of BM-MSCs was 0.29% (range 0.25-0.4). The complete reprogramming process lasted 14-16 days. Three to five hiPSC-colonies per sample were selected, expanded to 5 culture passages and then frozen. The whole procedure took an average time of 1.8 months (range 1.6-2.2). The hiPSC-lines expressed embryonic stem cell markers and exhibited pluripotency. This mRNA reprogramming method can be applicable in a hematopoietic stem cell culture lab setting and would be useful for the clinical translation of patient-specific hiPSCs.


Assuntos
Reprogramação Celular/efeitos dos fármacos , Doenças Hematológicas/terapia , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Mesenquimais/citologia , RNA Mensageiro/farmacologia , Criança , Transplante de Células-Tronco Hematopoéticas , Humanos , Métodos , Medicina de Precisão/métodos , RNA Mensageiro/síntese química , Fatores de Tempo
15.
Chem Biol Interact ; 303: 79-89, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-30772286

RESUMO

The indiscriminate use of medicinal plants and herbal medicinal products concomitantly with conventional drugs may result in herb-drug interactions that may lead to fluctuations in drug bioavailability, therapeutic failure, and/or toxic effects. CYP450 enzymes play an important role in drug biotransformation and herb-drug interactions. Thus, the aim of this study was to develop and apply Caco-2 cells-based gene reporter assays to study in vitro the potential occurrence of CYP3A4 and CYP2D6 gene expression modulation by standardized extracts of selected medicinal plants. Reporter cell lines developed showed a significant increase in CYP3A4 and CYP2D6 reporter fluorescent emission, 4 and 16-fold respectively, when compared to the controls. The standardized extracts of Cecropia glaziovii, Bauhinia forficata and Echinacea sp. significantly increased CYP3A4 reporter fluorescence, and those of Ilex paraguariensis, Bauhinia forficata and Echinacea sp. significantly decreased CYP2D6 reporter fluorescence in Caco-2 cells-based gene reporter assays. The data obtained suggest that CYP3A4 and CYP2D6 gene expression seem to be modulated by the extracts tested. In addition, the reporter cell lines developed are functional assays that could be used to study drug-drug and herb-drug interactions during the research and development of new drugs.


Assuntos
Citocromo P-450 CYP2D6/metabolismo , Citocromo P-450 CYP3A/metabolismo , Genes Reporter , Interações Ervas-Drogas , Células CACO-2 , Fluorescência , Expressão Gênica/efeitos dos fármacos , Humanos , Métodos , Extratos Vegetais/farmacologia , Plantas Medicinais
16.
Chemosphere ; 222: 114-123, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30703650

RESUMO

A methodology combining experimental design methodology, liquid chromatography, excitation emission matrixes (EEM) and bioassays has been applied to study the performance of O3 and O3/UVA-vis in the treatment of a mixture of eight phenolic pollutants. An experimental design methodology based on Doehlert matrixes was employed to determine the effect of pH (between 3 and 12), ozone dosage (02-1.0 g/h) and initial concentration of the pollutants (1-6 mg/L each). The following conclusions were obtained: a) acidic pH and low O3 dosage resulted in an inefficient process, b) increasing pH and O3 amount produced an enhancement of the reaction, and c) interaction of basic pH and high amounts of ozone decreased the efficiency of the process. The combination of O3/UVA-vis was able to enhance ozonation in those experimental regions were this reagent was less efficient, namely low pH and low ozone dosages. The application of EEM-PARAFAC showed four components, corresponding to the parent pollutants and three different groups of reaction product and its evolution with time. Bioassys indicated important detoxification (from 100% to less than 30% after 1 min of treatment with initial pollutant concentration of 6 mg/L, pH = 9 and ozone dosage of 0.8 g/h) according to the studied methods (D. magna and P. subcapitata). Also estrogenic activity and dioxin-like behavior were significantly decreased.


Assuntos
Ozônio/química , Fenóis/química , Raios Ultravioleta , Poluentes Químicos da Água/química , Bioensaio , Cromatografia Líquida , Fluorometria , Concentração de Íons de Hidrogênio , Métodos , Fenóis/toxicidade , Poluentes Químicos da Água/toxicidade
17.
Blood Cells Mol Dis ; 75: 48-55, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30616104

RESUMO

Zebrafish is emerging as a promising model for the study of human cancers. Several xenograft models of zebrafish have been developed, particularly in larval stages (<48 h post fertilization) when the immune system of fish is not developed. However, xenografting in adult zebrafish requires laborious and transient methods of immune suppression (γ- irradiation or dexamethasone) that limits engraftment and survival of the tumor or fail to recapitulate specific characteristics of malignancies. Thus, the availability of a simple protocol to successfully engraft adult zebrafish, remains a challenge. The current study addresses this limitation and describes a robust method of xenografting in adult zebrafish. We describe a protocol that involves pre-conditioning of Casper, a pigmentation mutant of zebrafish with busulfan that led to a higher rate of engraftment of hepatocellular carcinoma and acute myeloid leukemia cells. To further ascertain the homing characteristics of the injected cancer cells, we transplanted adult zebrafish by two routes of administration and then studied their compartmentalization. This model presents a valuable alternative to rodents to study the biology of these cancers and also a cost-effective platform for evaluation of potential anti-cancer agents.


Assuntos
Carcinoma Hepatocelular/patologia , Modelos Animais de Doenças , Xenoenxertos , Leucemia Mieloide Aguda/patologia , Neoplasias Hepáticas Experimentais/patologia , Peixe-Zebra , Animais , Bussulfano/farmacologia , Compartimento Celular , Humanos , Métodos
18.
Biometrics ; 75(2): 392-403, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30648746

RESUMO

In this article, we introduce the concept of model confidence bounds (MCB) for variable selection in the context of nested models. Similarly to the endpoints in the familiar confidence interval for parameter estimation, the MCB identifies two nested models (upper and lower confidence bound models) containing the true model at a given level of confidence. Instead of trusting a single selected model obtained from a given model selection method, the MCB proposes a group of nested models as candidates and the MCB's width and composition enable the practitioner to assess the overall model selection uncertainty. A new graphical tool-the model uncertainty curve (MUC)-is introduced to visualize the variability of model selection and to compare different model selection procedures. The MCB methodology is implemented by a fast bootstrap algorithm that is shown to yield the correct asymptotic coverage under rather general conditions. Our Monte Carlo simulations and real data examples confirm the validity and illustrate the advantages of the proposed method.


Assuntos
Intervalos de Confiança , Modelos Estatísticos , Algoritmos , Interpretação Estatística de Dados , Humanos , Métodos , Método de Monte Carlo , Incerteza
19.
PLoS One ; 14(1): e0211225, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30677098

RESUMO

The endophytic Streptomyces sp. VV/E1, and rhizosphere Streptomyces sp. VV/R4 strains, isolated from grapevine plants were shown in a previous work to reduce the infection rate of fungal pathogens involved in young grapevine decline. In this study we cloned fragments from randomly amplified polymorphic DNA (RAPD), and developed two stably diagnostic sequence-characterized amplified region (SCAR) markers of 182 and 160 bp for the VV/E1 and VV/R4 strains, respectively. The SCAR markers were not found in another 50 actinobacterial strains isolated from grapevine plants. Quantitative real-time PCR protocols based on the amplification of these SCAR markers were used for the detection and quantification of both strains in plant material. These strains were applied on young potted plants using two methods: perforation of the rootstock followed by injection of the microorganisms or soaking the root system in a bacterial suspension. Both methods were combined with a booster treatment by direct addition of a bacterial suspension to the soil near the root system. Analysis of uprooted plants showed that those inoculated by injection exhibited the highest rate of colonization. In contrast, direct addition of either strain to the soil did not lead to reliable colonization. This study has developed molecular tools for analyzing different methods for inoculating grapevine plants with selected Streptomyces sp. strains which protect them from fungal infections that enter through their root system. These tools are of great applied interest since they could easily be established in nurseries to produce grafted grapevine plants that are protected against fungal pathogens. Finally, this methodology might also be applied to other vascular plants for their colonization with beneficial biological control agents.


Assuntos
Inoculantes Agrícolas , Agentes de Controle Biológico/análise , Doenças das Plantas/prevenção & controle , Vitis/microbiologia , Inoculantes Agrícolas/crescimento & desenvolvimento , Endófitos , Métodos , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Vitis/toxicidade
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