Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
2.
Eur J Psychol ; 18(3): 293-301, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36348819

RESUMEN

Tests are updated and revised periodically in order to remain current, valid and reliable in a competitive psychological testing industry. Despite the prevalence of test revisions, especially in recent years, a number of authors have commented on the lack of comprehensive guidelines for test revision. Whilst some guideline documents from test associations have mentioned test revision, these guidelines tend to be focussed on test user responsibility, with limited guidance for practitioners embarking on a test revision project. Test revision is expensive and time consuming, leaving little scope for experimentation or trial-and-error. Test revision deserves a comprehensive document that addresses aspects such as what the different types of revision are, when to embark on a revision, what process to follow and how test users should use revised tests. The current study developed a comprehensive and practical set of 23 guidelines across ten phases of a revision project to assist revision teams, test users and publishers. These guidelines were peer-reviewed and refined.

3.
Ecol Evol ; 11(10): 5511-5521, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34026025

RESUMEN

Anthropogenic land use changes have broad impacts on biological diversity, often resulting in shifts in community composition. While many studies have documented negative impacts on occurrence and abundance of species, less attention has been given to native species that potentially benefit from anthropogenic land use changes. For many species reaching high densities in human-dominated landscapes, it is unclear whether these environments represent higher quality habitat than more natural environments. We examined the influence of landscape ecological integrity on relative abundance and body condition of two native generalist freshwater turtle species that are prevalent in anthropogenic systems, the painted turtle (Chrysemys picta) and red-eared slider (Trachemys scripta elegans). Relative abundance was negatively associated with ecological integrity for both species, but the relationship was not strongly supported for painted turtles. Body condition was positively associated with ecological integrity for painted turtles, with no strong association for red-eared sliders. Our study suggests that both species benefitted at the population level from reduced ecological integrity, but individual-level habitat quality was reduced for painted turtles. The differing responses between these two habitat generalists could partially explain why red-eared sliders have become a widespread exotic invasive species, while painted turtles have not.

4.
Oncol Res ; 16(11): 497-506, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18306929

RESUMEN

Resistance to cisplatin represents a major obstacle in the effective management of many cancers, including metastatic breast cancer. We aimed to gain further understanding of the mechanisms underlying development of cisplatin resistance using an in vitro cell line model. The MCF-7 breast cancer cell line and a novel derivative displaying significant resistance to cisplatin were analyzed using two-dimensional gel electrophoresis. The protein profiles were compared and 15 differentially expressed proteins were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The downregulation of beta-tubulin type 3, cytokeratin 17, tropomyosin 1-alpha, peroxiredoxin 4, heat shock 27-kDa protein 1, glutathione-S-transferase mu 3, ribosomal protein P0, isocitrate dehydrogenase 3, and peptidyl-prolyl isomerase A isoform 1 was associated with cisplatin-resistant cells. In contrast, the expression of hydroxyprostaglandin dehydrogenase 15-(NAD), matrix metalloproteinase 9, heterogeneous nuclear ribonucleoprotein A3, proteasome beta 1 subunit, electron transfer flavoprotein beta-polypeptide isoform 1, and peptidyl-propyl isomerase B precursor was upregulated in cisplatin-resistant cells. The downregulation (at least twofold) of glutathione-S-transferase mu 3, cytokeratin 17, and peroxiredoxin 4 was confirmed by Western blotting. We have identified alterations in the expression levels of several proteins that may be associated with cisplatin resistance and are candidates for further validation in clinical samples.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Cisplatino/farmacología , Resistencia a Antineoplásicos , Proteínas de Neoplasias/metabolismo , Proteómica/métodos , Western Blotting , Línea Celular Tumoral , Regulación hacia Abajo , Electroforesis en Gel Bidimensional , Femenino , Humanos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Regulación hacia Arriba
5.
Mol Cancer Ther ; 5(8): 2115-20, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16928833

RESUMEN

Doxorubicin is considered to be the most effective agent in the treatment of breast cancer patients. Unfortunately, resistance to this agent is common, representing a major obstacle to successful treatment. The identification of novel biomarkers that are able to predict treatment response may allow therapy to be tailored to individual patients. Antibody microarrays provide a powerful new technique, enabling the global comparative analysis of many proteins simultaneously. This technology may identify a panel of proteins to discriminate between drug-resistant and drug-sensitive samples. The Panorama Cell Signaling Antibody Microarray was exploited to analyze the MDA-MB-231 breast cancer cell line and a novel derivative, which displays significant resistance to doxorubicin at clinically relevant concentrations. The microarray comprised 224 antibodies selected from a variety of pathways, including apoptotic and cell signaling pathways. A standard >/=2.0-fold cutoff value was used to determine differentially expressed proteins. A decrease in the expression of mitogen-activated protein kinase-activated monophosphotyrosine (phosphorylated extracellular signal-regulated kinase; 2.8-fold decrease), cyclin D2 (2.5-fold decrease), cytokeratin 18 (2.5-fold decrease), cyclin B1 (2.4-fold decrease), and heterogeneous nuclear ribonucleoprotein m3-m4 (2.0-fold decrease) was associated with doxorubicin resistance. Western blotting was exploited to confirm results from the antibody microarray experiment. These results suggest that antibody microarrays can be used to identify novel biomarkers and further validation may reveal mechanisms of chemotherapy resistance and identify potential therapeutic targets. [Mol Cancer Ther 2006;5(8):2115-20].


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Anticuerpos , Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Análisis por Matrices de Proteínas/métodos , Western Blotting , Femenino , Humanos , Células Tumorales Cultivadas
6.
Psychol Rep ; 94(2): 694-6, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15154204

RESUMEN

Social cognitive career theory suggests that males and females may not differ in career decision-making self-efficacy, but this statement requires extension of research to high school samples. The Career Decision-making Self-efficacy Scale-Short Form was administered to white South African high school students in Grades 9 to 11, of whom 368 were boys and 494 girls. No significant sex differences were found, suggesting that career interventions based on social cognitive career theory in high school need not be sex-specific in content.


Asunto(s)
Selección de Profesión , Toma de Decisiones , Autoeficacia , Estudiantes/psicología , Adolescente , Femenino , Humanos , Masculino , Modelos Psicológicos , Inventario de Personalidad/estadística & datos numéricos , Factores Sexuales , Sudáfrica/etnología , Población Blanca/psicología
7.
Neoplasia ; 11(11): 1194-207, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19881955

RESUMEN

PURPOSE: We aimed to identify putative predictive protein biomarkers of radioresistance. EXPERIMENTAL DESIGN: Three breast cancer cell lines (MCF7, MDA-MB-231, and T47D) were used as in vitro models to study radioresistance. Inherent radiosensitivities were examined using a clonogenic survival assay. It was revealed that each cell line differed in their response to radiotherapy. These parental breast cancer cell lines were used to establish novel derivatives (MCF7RR, MDA-MB-231RR, and T47DRR) displaying significant resistance to ionizing radiation. Derivative cells were compared with parental cells to identify putative biomarkers associated with the radioresistant phenotype. To identify these biomarkers, complementary proteomic screening approaches were exploited encompassing two-dimensional gel electrophoresis in combination with mass spectrometry, liquid chromatography coupled with tandem mass spectrometry and quantitative proteomics using iTRAQ technology. RESULTS: A large number of potential biomarkers were identified, and several of these were confirmed using Western blot analysis. In particular, a decrease in the expression of the 26S proteasome was found in all radioresistant derivatives when compared with the respective parent cells. Decreased expression of this target was also found to be associated with radioresistant laryngeal tumors (P = .05) in a small pilot immunohistochemical study. CONCLUSIONS: These findings suggest that the 26S proteasome may provide a general predictive biomarker for radiotherapy outcome.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Complejo de la Endopetidasa Proteasomal/biosíntesis , Tolerancia a Radiación/genética , Western Blotting , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Cromatografía Liquida , Electroforesis en Gel Bidimensional , Femenino , Perfilación de la Expresión Génica , Humanos , Inmunohistoquímica , Análisis de Secuencia por Matrices de Oligonucleótidos , Complejo de la Endopetidasa Proteasomal/genética , Proteómica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrometría de Masas en Tándem
8.
Anticancer Drugs ; 18(7): 749-54, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17581296

RESUMEN

Chemotherapy resistance is one of the most prevalent obstacles to the treatment of cancer, resulting in increased mortality and prolonged exposure to cytotoxic agents with no treatment benefit. One of the tools utilized in the study of mechanisms of chemotherapy resistance are established cell lines derived from human neoplasms. These cell lines can be challenged in vitro with controlled chemotherapy doses to produce chemotherapy-resistant variants. Analysis of these novel chemotherapy-resistant cell lines may then identify genetic and proteomic changes which are associated with the resistant phenotype. Two very important mediators of chemotherapy resistance (P-glycoprotein and multidrug resistance protein-1) were initially identified in chemotherapy-resistant cell lines. To make these in-vitro studies clinically relevant it is, however, necessary to duplicate as far as possible the treatment conditions used in vivo. Considerations should include clinically relevant drug concentrations, such as those derived from peak plasma values, and the type of treatment schedule to be employed.


Asunto(s)
Antineoplásicos/farmacología , Resistencia a Antineoplásicos , Neoplasias/tratamiento farmacológico , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Técnicas de Cultivo de Célula/métodos , Línea Celular Tumoral , Humanos , Modelos Biológicos , Neoplasias/fisiopatología , Fenotipo , Reproducibilidad de los Resultados
9.
Acta Oncol ; 46(5): 651-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17562441

RESUMEN

We aimed to investigate the mechanisms of cisplatin resistance using an in vitro cancer model. A derivative breast cancer cell line (MCF-7CR) was established which demonstrated significant resistance to cisplatin at clinically relevant low concentrations compared to the MCF-7 parental cell line. Expression microarray analysis was used to identify targets from a 3k cancer-related oligonucleotide platform which were differentially expressed between the derivative and parental cell lines. Real-time quantitative PCR was used to confirm the difference in expression of a subset of genes which demonstrated significant up- or down-regulation. Using expression microarray analysis a total of 28 genes were identified to be differentially expressed (by at least 2-fold) between the MCF-7 and MCF-7CR cells. Real-time quantitative PCR expression analysis confirmed the differential expression of a selection of these genes (ACTG2, ARHD, CTSL, GSTM3, GSTM4 and EHF) between the two cell lines. An in vitro model of cisplatin resistance has been established and expression microarray analysis revealed 28 genes which may be associated with cisplatin resistance.


Asunto(s)
Cisplatino/farmacología , Resistencia a Antineoplásicos/genética , Perfilación de la Expresión Génica , Análisis de Secuencia por Matrices de Oligonucleótidos , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Humanos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
10.
Ann Surg Oncol ; 13(6): 881-6, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16614877

RESUMEN

BACKGROUND: Although BRCA genes have been implicated in certain tumors, particularly breast tumors, their role in colon tumorigenesis has not been fully explored. We aimed to investigate the association of the BRCA2 and putative "BRCA3" genes in a homogeneous series of right-sided colon cancer specimens. METHODS: Twenty-three Dukes' stage C, replication error-negative carcinomas were selected from patients with right-sided colon cancer. After histological examination and microdissection, DNA was extracted from normal colon and carcinoma from each patient. Five microsatellite markers spanning the region of BRCA2 and BRCA3 on chromosome 13 (D13S218, D13S219, D13S165, D13S156, and D13S160) and two markers intragenic to BRCA2 and BRCA3 (D13S171 and D13S1308, respectively) were used. Polymerase chain reaction products were analyzed by using a fluorescent allele imbalance assay. RESULTS: Markers demonstrating the highest allelic imbalance were D13S1308 (53%), D13S171 (33%), and D13S160 (37%). CONCLUSIONS: The intragenic markers D13S1308 (BRCA3) and D13S171 (BRCA2) on chromosome 13 demonstrated a high frequency of allelic imbalance in primary colon carcinoma. This suggests an involvement of BRCA2 and putative BRCA3 in colon tumorigenesis in right-sided, replication error-negative, Dukes' stage C cancers. Further studies are needed to confirm the precise role of these genes, and any prognostic significance, in colon cancer.


Asunto(s)
Neoplasias del Colon/genética , Genes BRCA2 , Alelos , Cromosomas Humanos Par 13 , Neoplasias del Colon/patología , Daño del ADN , ADN de Neoplasias/genética , Genes Supresores de Tumor , Humanos , Pérdida de Heterocigocidad , Repeticiones de Microsatélite , Estadificación de Neoplasias , Reacción en Cadena de la Polimerasa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA