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BACKGROUND: Progesterone receptor (PR) expression assessment in early invasive breast cancer remains controversial. This study sought to re-evaluate PR expression as a potential therapeutic guide in early breast cancer; particularly in oestrogen receptor (ER)-positive, lymph node (LN)-negative disease. METHODS: A population cohort of 1074 patients presenting to a single Cancer Centre over 4 years (2000-2004) underwent surgery for primary invasive breast cancer with curative intent. Prospective data collection included patient demographics, pathology, ER and PR expression, HER2 status, adjuvant chemotherapy and endocrine therapy. Progesterone receptor expression was compared with (all causes) overall survival (OS), breast cancer-specific survival (BCSS) and disease-free survival (DFS). RESULTS: Overall survival was 71.0% and BCSS was 83.0% at median follow-up of 8.34 years. Absent PR expression was significantly associated with poorer prognosis for OS, BCSS and DFS (P<0.0001, log-rank), even within the ER-positive, LN-negative group (hazard ratio for BCSS 3.17, 95% CI 1.43-7.01) and was not influenced by endocrine therapy. Cox's regression analysis demonstrated that PR expression was an independent prognostic variable. CONCLUSION: Absence of PR expression is a powerful, independent prognostic variable in operable, primary breast cancer even in ER-positive, LN-negative patients receiving endocrine therapy. Absence of PR expression should be re-evaluated as a biomarker for poor prognosis in ER-positive breast cancer and such patients considered for additional systemic therapy.
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Biomarcadores de Tumor/biosíntesis , Neoplasias de la Mama/genética , Detección Precoz del Cáncer , Receptores de Progesterona/biosíntesis , Adulto , Neoplasias de la Mama/patología , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Pronóstico , Receptor ErbB-2/genética , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/genéticaRESUMEN
The International Tamoxifen Pharmacogenomics Consortium was established to address the controversy regarding cytochrome P450 2D6 (CYP2D6) status and clinical outcomes in tamoxifen therapy. We performed a meta-analysis on data from 4,973 tamoxifen-treated patients (12 globally distributed sites). Using strict eligibility requirements (postmenopausal women with estrogen receptor-positive breast cancer, receiving 20 mg/day tamoxifen for 5 years, criterion 1); CYP2D6 poor metabolizer status was associated with poorer invasive disease-free survival (IDFS: hazard ratio = 1.25; 95% confidence interval = 1.06, 1.47; P = 0.009). However, CYP2D6 status was not statistically significant when tamoxifen duration, menopausal status, and annual follow-up were not specified (criterion 2, n = 2,443; P = 0.25) or when no exclusions were applied (criterion 3, n = 4,935; P = 0.38). Although CYP2D6 is a strong predictor of IDFS using strict inclusion criteria, because the results are not robust to inclusion criteria (these were not defined a priori), prospective studies are necessary to fully establish the value of CYP2D6 genotyping in tamoxifen therapy.
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Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Citocromo P-450 CYP2D6/genética , Tamoxifeno/uso terapéutico , Anciano , Antineoplásicos Hormonales/farmacocinética , Neoplasias de la Mama/genética , Femenino , Variación Genética/genética , Genotipo , Humanos , Menopausia , Persona de Mediana Edad , Farmacogenética/métodos , Análisis de Supervivencia , Tamoxifeno/farmacocinética , Resultado del TratamientoRESUMEN
BACKGROUND: Multiparameter flow cytometry is a robust and reliable method for determining tumour DNA content applicable to formalin-fixed paraffin-embedded (FFPE) tissue. This study examined the clinical and pathological associations of DNA content in primary breast cancer using an improved multiparametric technique. METHODS: The FFPE tissue from 201 primary breast cancers was examined and the cancers categorised according to their DNA content using multiparametric flow cytometry incorporating differential labelling of stromal and tumour cell populations. Mathematical modelling software (ModFit 3.2.1) was used to calculate the DNA index (DI) and percentage S-phase fraction (SPF%) for each tumour. Independent associations with clinical and pathological parameters were sought using backward stepwise Binary Logistic Regression (BLR) and Cox's Regression (CR) analysis. RESULTS: Tumours were grouped into four categories based on the DI of the tumour cell population. Low DI tumours (DI=0.76-1.14) associated with progesterone receptor-positive status (P=0.012, BLR), intermediate DI (DI=1.18-1.79) associated with p53 mutant tumours (P=0.001, BLR), high DI (DIî¶1.80) tumours with human epidermal growth factor receptor 2 (HER2)-positive status (P=0.004, BLR) and 'multiploid tumours' (two or more tumour DNA peaks) did not show any significant associations. Tumours with high SPF% (î¶10%) independently associated with poor overall survival (P=0.027, CR). CONCLUSION: Multiparametric flow analysis of FFPE tissue can accurately assess tumour DNA content. Tumour sub-populations associated with biomarkers of prognosis or likely response to therapy. The alterations in DNA content present the potential for greater understanding of the mechanisms underlying clinically significant biomarker changes in primary breast cancer.
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Neoplasias de la Mama/genética , ADN de Neoplasias/análisis , Citometría de Flujo/métodos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/mortalidad , Femenino , Genes p53 , Humanos , Persona de Mediana Edad , Mutación , Pronóstico , Receptor ErbB-2/análisis , Receptores de Progesterona/metabolismoRESUMEN
PURPOSE: Over one million American firefighters are routinely exposed to various occupational hazards agents. While efforts have been made to identify and reduce some causes of injuries and illnesses among firefighters, relatively little has been done to evaluate and understand occupational noise exposures in this group. The purpose of this pilot study was to apply a task-based noise exposure assessment methodology to firefighting operations to evaluate potential noise exposure sources, and to use collected task-based noise levels to create noise exposure estimates for evaluation of risk of noise-induced hearing loss by comparison to the 8-hr and 24-hr recommended exposure limits (RELs) for noise of 85 and 80.3 dBA, respectively. METHODS: Task-based noise exposures (n=100 measurements) were measured in three different fire departments (a rural department in Southeast Michigan and suburban and urban departments in Northern California). These levels were then combined with time-at-task information collected from firefighters to estimate 8-hr noise exposures for the rural and suburban fire departments (n=6 estimates for each department). Data from 24-hr dosimetry measurements and crude self-reported activity categories from the urban fire department (n=4 measurements) were used to create 24-hr exposure estimates to evaluate the bias associated with the task-based estimates. RESULTS: Task-based noise levels were found to range from 82-109 dBA, with the highest levels resulting from use of saws and pneumatic chisels. Some short (e.g., 30 min) sequences of common tasks were found to result in nearly an entire allowable daily exposure. The majority of estimated 8-hr and 24-hr exposures exceeded the relevant recommended exposure limit. Predicted 24-hr exposures showed substantial imprecision in some cases, suggesting the need for increased task specificity. CONCLUSIONS: The results indicate potential for overexposure to noise from a variety of firefighting tasks and equipment, and suggest a need for further exposure characterization and additional hearing loss prevention efforts. RELEVANCE TO INDUSTRY: Firefighters may be at risk of noise-induced hearing loss, which can affect their fitness for duty and ability to respond effectively to emergencies. The results of this study suggest that additional efforts at hearing loss prevention among firefighters are warranted.
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BACKGROUND: Relapse risk assessment and individual treatment recommendations remain suboptimal for breast cancer patients. In the light of existing preclinical and clinical data, we studied NT5E (5'-nucleotidase, ecto) expression and NT5E CpG island methylation in breast cancer. METHODS: We used RT-PCR, qPCR, methylation-specific PCR and pyrosequencing to analyse NT5E in breast carcinoma cell lines and primary and breast carcinomas. RESULTS: NT5E CpG island methylation was inversely associated with NT5E expression in breast carcinoma cell lines. In clinical series, patients whose primary tumours had NT5E CpG island methylation were less likely to develop metastasis (P=0.003, OR=0.34, 95% CI: 0.17-0.69). In 3/4 paired samples, NT5E was methylated in primary tumours and demethylated in CNS metastases. Patients progressing to non-visceral as compared with visceral metastases were more likely to have NT5E CpG island methylation in primary tumours (P=0.01, OR=11.8). Patients with tumours lacking detectable methylation had shorter disease-free survival (DFS) (P=0.001, HR=2.7) and overall survival (OS) (P=0.001, HR=3). The favourable prognostic value of NT5E methylation was confirmed in oestrogen receptor negative (P=0.011, HR=3.27, 95% CI: 1.31-8.12) and in triple negative cases (P=0.004; HR=6.2, 95% CI: 1.9-20). Moreover, we observed a more favourable outcome to adjuvant chemotherapy in patients whose tumours were positive for NT5E CpG island methylation: DFS (P=0.0016, HR=5.1, 95% CI: 1.8-14.37) and OS (P=0.0005, HR=7.4, 95% CI: 2.416-23.08). CONCLUSION: NT5E CpG island methylation is a promising breast cancer biomarker.
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5'-Nucleotidasa/genética , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/genética , Metilación de ADN , Neoplasias de la Mama/patología , Línea Celular Tumoral , Islas de CpG , Supervivencia sin Enfermedad , Femenino , Proteínas Ligadas a GPI/genética , Silenciador del Gen , Humanos , Metástasis de la Neoplasia/genética , Pronóstico , Regiones Promotoras GenéticasRESUMEN
BACKGROUND: Brain metastasis from breast cancer is usually associated with a poor prognosis and early death. Alteration of p53 may contribute to malignant progression by abrogation of apoptosis induced by oncogene activation and by acquisition of gain-of-function properties, which promote tumour aggression. Mutation in TP53 occurs at high frequency in carcinomas of the lung and gastro-intestinal tract, but is much less frequent, at 25%, in primary breast cancer. The frequency of TP53 alteration in the central nervous system (CNS) metastatic breast cancer is not known. METHODS: In all, 23 cases of histologically confirmed CNS metastatic breast cancer were identified and the coding sequence of TP53 determined. TP53 was also sequenced in two control series of primary breast carcinomas from independent clinical centres. RESULTS: We demonstrate a strikingly high frequency of TP53 mutation in the CNS metastatic lesions with an over-representation of complex mutations (non-sense/deletions/insertions). Complex mutations occur in metastatic lesions in both triple-negative breast cancer and hormone receptor/HER2-positive cases. Analysis of paired primary carcinomas and brain metastatic lesions revealed evidence for both clonal selection and generation of new mutations (missense and complex) in progression from a primary breast carcinoma to brain metastasis. CONCLUSION: Mutation in TP53 is the most common genetic alteration reported during metastasis to the brain in breast cancer.
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Neoplasias de la Mama/genética , Neoplasias del Sistema Nervioso Central/secundario , Genes p53 , Mutación , Secuencia de Bases , Neoplasias de la Mama/patología , Neoplasias del Sistema Nervioso Central/genética , Cartilla de ADN , Femenino , HumanosRESUMEN
Tumor growth factor-ß (TGF-ß) signaling in cancer has been implicated in growth suppression of early lesions and enhancing tumor cell invasion and metastasis. However, the cellular mechanisms that determine this signaling output in individual tumors are still largely unknown. In endothelial cells, TGF-ß signaling is modulated by the TGF-ß co-receptor endoglin (CD105). Here we demonstrate that endoglin is expressed in a subset of invasive breast cancers and cell lines and is subject to epigenetic silencing by gene methylation. Endoglin downregulation in non-tumorigenic MCF10A breast cells leads to the formation of abnormal acini in 3D culture, but does not promote cell migration or transformation. In contrast, in the presence of activated ErbB2, endoglin downregulation in MCF10A cells leads to enhanced invasion into a 3D matrix. Consistent with these data, ectopic expression of endoglin in MDA-MB-231 cells blocks TGF-ß-enhanced cell motility and invasion and reduces lung colonization in an in vivo metastasis model. Unlike endothelial cells, endoglin does not modulate Smad-mediated TGF-ß signaling in breast cells but attenuates the cytoskeletal remodeling to impair cell migration and invasion. Importantly, in a large cohort of invasive breast cancers, lack of endoglin expression in the tumor cell compartment correlates with ENG gene methylation and poor clinical outcome.
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Antígenos CD/genética , Antígenos CD/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Metilación de ADN/genética , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Endoglina , Femenino , Silenciador del Gen , Humanos , Pulmón/patología , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/secundario , Ratones , Ratones Desnudos , Invasividad Neoplásica , Metástasis de la Neoplasia , Reacción en Cadena de la Polimerasa , Pronóstico , Receptor ErbB-2/metabolismo , Transducción de Señal , Factor de Crecimiento Transformador beta/genéticaRESUMEN
The RNA helicase p68 is a potent co-activator of p53-dependent transcription in response to DNA damage. Previous independent studies have indicated that p68 and the Δ133p53 isoforms, which modulate the function of full-length p53, are aberrantly expressed in breast cancers. Here we identify a striking inverse association of p68 and Δ133p53 expression in primary breast cancers. Consistent with these findings, small interfering RNA depletion of p68 in cell lines results in a p53-dependant increase of Δ133p53 in response to DNA damage, suggesting that increased Δ133p53 expression could result from downregulation of p68 and provide a potential mechanistic explanation for our observations in breast cancer. Δ133p53α, which has been shown to negatively regulate the function of full-length p53, reciprocally inhibits the ability of p68 to stimulate p53-dependent transcription from the p21 promoter, suggesting that Δ133p53α may be competing with p68 to regulate p53 function. This hypothesis is underscored by our observations that p68 interacts with the C-terminal domain of p53, co-immunoprecipitates 133p53α from cell extracts and interacts only with p53 molecules that are able to form tetramers. These data suggest that p68, p53 and 133p53α may form part of a complex feedback mechanism to regulate the expression of Δ133p53, with consequent modification of p53-mediated transcription, and may modulate the function of p53 in breast and other cancers that harbour wild-type p53.
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Neoplasias de la Mama/metabolismo , ARN Helicasas DEAD-box/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Regiones Promotoras Genéticas , Dominios y Motivos de Interacción de Proteínas , Isoformas de Proteínas/metabolismo , ARN Interferente Pequeño/metabolismoRESUMEN
BACKGROUND: This study assessed the impact of human epidermal growth factor receptor 2 (HER2) status on the outcomes in an unselected population of breast cancer patients who did not receive HER2-targeted therapy. METHODS: HER2 status by immunohistochemistry and fluorescence in situ hybridisation was compared with clinicopathological data, overall survival (OS) and disease-free survival (DFS) for all patients presenting with breast cancer over 3 years. RESULTS: In 865 patients (median follow up 6.02 years), HER2 positivity was identified in 13.3% of all cancers and was associated with higher tumour grade (P<10(-8)), lymphovascular invasion (P<0.001) and axillary nodal metastasis (P=0.003). There was a negative association with oestrogen-receptor (ER) and progesterone-receptor expression (P<10(-8)), but the majority (57%) of HER2+tumours were ER+HER2 positivity was associated with poorer OS (P=0.0046) and DFS (P=0.0001) confined to the lymph node-positive (LN+) and ER+ subgroups. CONCLUSION: HER2-positive cancers were less common in this population-based cohort than most selected series. The association of HER2 positivity with poor prognosis was confined to the ER+ and LN+ subgroups. The survival deficit for the 7.5% of patients with ER+/HER2+ cancer compared with ER+/HER2- patients points to a significant subgroup of women who may not (currently) be considered for HER2-directed therapy.
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Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/mortalidad , Receptor ErbB-2/metabolismo , Receptores de Estrógenos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Femenino , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Persona de Mediana Edad , Análisis de SupervivenciaRESUMEN
BACKGROUND: The deprivation gap for breast cancer survival remains unexplained by stage at presentation, treatment, or co-morbidities. We hypothesised that p53 mutation might contribute to the impaired outcome observed in patients from deprived communities. METHODS: p53 mutation status was determined using the Roche Amplichip research test in 246 women with primary breast cancer attending a single cancer centre and related to deprivation, pathology, overall, and disease-free survival. RESULTS: p53 mutation, identified in 64/246 (26%) of cancers, was most common in 10 out of 17 (58.8%) of the lowest (10th) deprivation decile. Those patients with p53 mutation in the 10th decile had a significantly worse disease-free survival of only 20% at 5 years (Kaplan-Meier logrank chi(2)=6.050, P=0.014) and worse overall survival of 24% at 5 years (Kaplan-Meier logrank chi(2)=6.791, P=0.009) than women of deciles 1-9 with p53 mutation (c.f. 56% and 72%, respectively) or patients in the 10th decile with wild-type p53 (no disease relapse or deaths). CONCLUSION: p53 mutation in breast cancer is associated with socio-economic deprivation and may provide a molecular basis, with therapeutic implications, for the poorer outcome in women from deprived communities.
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Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/genética , Carencia Psicosocial , Proteína p53 Supresora de Tumor/genética , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/psicología , Femenino , Frecuencia de los Genes , Humanos , Persona de Mediana Edad , Mutación , Pronóstico , Clase Social , Análisis de SupervivenciaRESUMEN
Expression of P3H2 (Leprel1) and P3H3 (Leprel2) but not P3H1 (Leprecan) is down-regulated in breast cancer by aberrant CpG methylation in the 5' regulatory sequences of each gene. Methylation of P3H2 appears specific to breast cancer as no methylation was detected in a range of cell lines from other epithelial cancers or from primary brain tumours or malignant melanoma. Methylation in P3H2, but not P3H3, was strongly associated with oestrogen-receptor-positive breast cancers, whereas methylation in P3H3 was associated with higher tumour grade and Nottingham Prognostic Index. Ectopic expression of P3H2 and P3H3 in cell lines with silencing of the endogenous gene results in suppression of colony growth. This is the first demonstration of epigenetic inactivation of prolyl hydroxylases in human cancer, implying that this gene family represents a novel class of tumour suppressors. The restriction of silencing in P3H2 to breast carcinomas, and its association with oestrogen-receptor-positive cases, suggests that P3H2 may be a breast-cancer-specific tumour suppressor.
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Neoplasias de la Mama/genética , Carcinoma/genética , Epigénesis Genética/fisiología , Regulación Neoplásica de la Expresión Génica , Procolágeno-Prolina Dioxigenasa/genética , Línea Celular Tumoral , Células Cultivadas , Islas de CpG/genética , Metilación de ADN/fisiología , Regulación hacia Abajo , Femenino , Silenciador del Gen , Genes Supresores de Tumor/fisiología , Humanos , Procolágeno-Prolina Dioxigenasa/fisiología , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Ensayo de Tumor de Célula MadreRESUMEN
OBJECTIVES: Self-reported exposure to vapours, gas, dust or fumes (VGDF) has been widely used as an occupational exposure metric in epidemiological studies of chronic lung diseases. Our objective was to characterise the performance of VGDF for repeatability, systematic misclassification, and sensitivity and specificity against exposure likelihood by a job-exposure matrix (JEM). METHODS: We analysed data from two interviews, 24 months apart, of adults with asthma and chronic rhinitis. Using distinct job as the unit of analysis, we tested a single response item (exposure to VGDF) against assignment using a JEM. We further analysed VGDF and the JEM among a subset of 199 subjects who reported the same job at both interviews, using logistic regression analysis to test factors associated with VGDF inconsistency and discordance with the JEM. RESULTS: VGDF was reported for 193 (44%) of 436 distinct jobs held by the 348 subjects studied; moderate to high exposure likelihood by JEM was assigned to 120 jobs (28%). The sensitivity and specificity of VGDF against JEM were 71% and 66%, respectively. Among 199 subjects with the same job at both interviews, 32% had a discordant VGDF status (kappa = 0.35). Those with chronic rhinitis without concomitant asthma compared to asthma alone were more likely to have a VGDF report discordant with the JEM (OR 3.6, 95% CI 1.4 to 9.0; p = 0.01). Rhinitis was also associated with reported VGDF in a job classified by the JEM as low exposure (OR 3.9, 95% CI 1.6 to 9.4; p = 0.003). CONCLUSION: The VGDF item is moderately sensitive measured against JEM as a benchmark. The measure is a useful assessment method for epidemiological studies of occupational exposure risk.
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Contaminantes Ocupacionales del Aire/toxicidad , Asma/etiología , Enfermedades Profesionales/etiología , Exposición Profesional , Rinitis/etiología , Adulto , Contaminantes Ocupacionales del Aire/análisis , Interpretación Estadística de Datos , Polvo , Gases , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional/análisis , Salud Laboral , Ocupaciones , Medición de Riesgo/métodos , Autorrevelación , Sensibilidad y EspecificidadRESUMEN
Catatonia is a life-threatening disorder characterized by motor abnormalities, mutism, and disturbances of behaviour, which is increasingly being diagnosed in persons with autism. In this report, we describe the presentation and course of catatonia in an adolescent with autism who responded to electroconvulsive therapy (ECT). The illness started with depressive symptoms, but the predominant feature was one of extreme obsessive slowing and immobility. We propose that catatonia should be ruled out as a cause of regression sometimes seen in adolescents with autism, and that catatonia of autism may index a distinct subtype with a particularly poor outcome.
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Trastorno Autístico/complicaciones , Catatonia/complicaciones , Catatonia/diagnóstico , Adolescente , Antidepresivos de Segunda Generación/uso terapéutico , Catatonia/terapia , Citalopram/uso terapéutico , Terapia Combinada , Terapia Electroconvulsiva/métodos , Hospitalización , Humanos , Masculino , Índice de Severidad de la EnfermedadRESUMEN
Animal and human studies have shown that greatly increasing the amount of fish oil [rich in long-chain (n-3) PUFA] in the diet can decrease lymphocyte functions. The effects of a more modest provision of long-chain (n-3) PUFA and whether eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6) have the same effects as one another are unclear. Whether the position of 20:5 or 22:6 in dietary triacylglycerols (TAG) influences their incorporation into immune cells and their subsequent functional effects is not known. In this study, male weanling rats were fed for 6 wk one of 9 diets that contained 178 g lipid/kg and that differed in the type of (n-3) PUFA and in the position of these in dietary TAG. The control diet contained 4.4 g alpha-linolenic acid (18:3)/100 g total fatty acids. In the other diets, 20:5 or 22:6 replaced a portion (50 or 100%) of 18:3, and were in the sn-2 or the sn-1(3) position of dietary TAG. There were significant dose-dependent increases in the proportion of 20:5 or 22:6 in spleen mononuclear cell phospholipids when 20:5 or 22:6 was fed. These increases were at the expense of arachidonic acid and were largely independent of the position of 20:5 or 22:6 in dietary TAG. Spleen lymphocyte proliferation increased dose dependently when 20:5 was fed in the sn-1(3) position of dietary TAG. There were no significant differences in interleukin-2, interferon-gamma or interleukin-10 production among spleen cells from rats fed the different diets. Prostaglandin E(2) production by spleen mononuclear cells was decreased by inclusion of either 20:5 or 22:6 in the diet in the sn-1(3) position. Thus, incorporation of 20:5 or 22:6 into spleen mononuclear cell phospholipids is not influenced by the position in dietary TAG. However, the pattern of incorporation may be influenced, and there are some differential functional effects of the position of long-chain (n-3) PUFA in dietary TAG. A moderate increase in the intake of 20:5 at the sn-1(3) position of dietary TAG increases lymphocyte proliferation.
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Ácido Eicosapentaenoico/química , Ácido Eicosapentaenoico/farmacología , Linfocitos/citología , Triglicéridos/administración & dosificación , Triglicéridos/química , Animales , Peso Corporal , División Celular/efectos de los fármacos , Células Cultivadas , Concanavalina A/farmacología , Citocinas/metabolismo , Dieta , Ácidos Grasos/metabolismo , Leucocitos Mononucleares/metabolismo , Tejido Linfoide/anatomía & histología , Masculino , Estructura Molecular , Tamaño de los Órganos , Fosfolípidos/metabolismo , Ratas , Ratas Endogámicas Lew , Bazo/citología , Bazo/metabolismoAsunto(s)
Antipsicóticos/administración & dosificación , Trastornos Generalizados del Desarrollo Infantil/tratamiento farmacológico , Haloperidol/análogos & derivados , Haloperidol/administración & dosificación , Cooperación del Paciente , Administración Oral , Niño , Trastornos de la Conducta Infantil/etiología , Trastornos Generalizados del Desarrollo Infantil/complicaciones , Humanos , Inyecciones Intramusculares , Masculino , Resultado del TratamientoRESUMEN
Within a stereoscopic display the field of view (FOV) was held constant at 13.86 degrees while the geometric field of view (GFOV) was varied across four levels: 0 degrees (parallel), 13.86 degrees (veridical), 50 degrees and 100 degrees. Participants performed a distance-matching task where they adjusted the distance of a standard track from the centre of the display to match the distance of a target track from the same point. The results indicated that while the least error occurred in the veridical GFOV condition, small variations of GFOV away from the veridical have little effect. Large differences between FOV and GFOV (36 degrees and 86 degrees) increased errors markedly. A trend toward better performance in the veridical GFOV condition relative to the parallel GFOV condition suggests that the use of linear perspective information in a stereoscopic display may facilitate more accurate spatial perception. Actual or potential applications of this work include stereoscopic display design in aviation and non-aviation settings.
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Medicina Aeroespacial , Percepción de Profundidad/fisiología , Reconocimiento Visual de Modelos , Adulto , Atención , Aviación , Percepción de Distancia , Análisis Factorial , Femenino , Humanos , Juicio , Masculino , Sensibilidad y Especificidad , Simulación del EspacioRESUMEN
The objective of this study was to determine the effect of caffeine level in tea and coffee on acute physiological responses and mood. Randomised full crossover design in subjects after overnight caffeine abstention was studied. In study 1 (n = 17) the caffeine level was manipulated naturalistically by preparing tea and coffee at different strengths (1 or 2 cups equivalent). Caffeine levels were 37.5 and 75 mg in tea, 75 and 150 mg in coffee, with water and no-drink controls. In study 2 (n = 15) caffeine level alone was manipulated (water, decaffeinated tea, plus 0, 25, 50, 100, and 200 mg caffeine). Beverage volume and temperature (55 degrees C) were constant. SBP, DBP, heart rate, skin temperature, skin conductance, and mood were monitored over each 3-h study session. In study 1, tea and coffee produced mild autonomic stimulation and an elevation in mood. There were no effects of tea vs. coffee or caffeine dose, despite a fourfold variation in the latter. Increasing beverage strength was associated with greater increases in DBP and energetic arousal. In study 2, caffeinated beverages increased SBP, DBP, and skin conductance and lowered heart rate and skin temperature compared to water. Significant dose-response relationships to caffeine were seen only for SBP, heart rate, and skin temperature. There were significant effects of caffeine on energetic arousal but no consistent dose-response effects. Caffeinated beverages acutely stimulate the autonomic nervous system and increase alertness. Although caffeine can exert dose-dependent effects on a number of acute autonomic responses, caffeine level is not an important factor. Factors besides caffeine may contribute to these acute effects.
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Afecto/efectos de los fármacos , Sistema Nervioso Autónomo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Cafeína/farmacología , Café , Té , Adulto , Sistema Nervioso Autónomo/fisiología , Cafeína/análisis , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Saliva/metabolismo , Piel/inervación , Temperatura Cutánea/efectos de los fármacosRESUMEN
Two experiments are reported which examine immediate serial recall for high- and low-frequency words. The words in each list were either repeatedly drawn from the same small pool of candidates (in the closed set conditions) or each word only ever occurred once during the experiment (in the open set conditions). The results consistently show an effect of word frequency but the effect of set size was only apparent for low-frequency words. It is argued that both frequency and set size effects reflect processes concerning the "clean-up" of degraded short-term memory traces.
Asunto(s)
Memoria a Corto Plazo/fisiología , Recuerdo Mental , Adulto , Femenino , Humanos , Masculino , Fonética , Tamaño de la MuestraRESUMEN
RATIONALE: The effects of caffeine, especially caffeinated coffee, on human performance have been extensively studied. However, few studies have been naturalistic representations of how tea/coffee is normally consumed in terms of dose and time of consumption. OBJECTIVES: This study investigated the effects of day-long consumption of tea, coffee and water on cognitive and psychomotor performance, and sleep quality at night. METHODS: Thirty healthy volunteers received equal volume drinks equivalent to either 1 or 2 cups of tea (containing 37.5 mg or 75 mg caffeine), or coffee (75 mg or 150 mg caffeine), or water, in a randomised five-way crossover design. Drinks were administered on four occasions during the day (0900, 1300, 1700 and 2300 hours). A psychometric battery consisting of critical flicker fusion (CFF), choice reaction time (CRT) and subjective sedation (LARS) tests, was administered pre-dose and at frequent time points post-dose. The Leeds Sleep Evaluation Questionnaire (LSEQ) was completed each morning and a wrist actigraph was worn for the duration of the study. RESULTS: Caffeinated beverages maintained CFF threshold over the whole day (P<0.05), independent of caffeine dose or beverage type. During the acute phase of beverage ingestion, caffeine significantly sustained performance compared to water after the first beverage for CFF and subjective sedation (P<0.05), and after the second beverage for the Recognition component of the CRT task (P<0.05). Additionally, there were significant differences between tea and coffee at 75 mg caffeine after the first drink. Compared to coffee, tea produced a significant increase in CFF threshold between 30 and 90 min post-consumption (P<0.01). However, following the second beverage caffeinated coffee at 75 mg significantly improved reaction time (P<0.05), compared to tea at the same dose, for the Recognition component of the CRT task. Caffeinated beverages had a dose dependent negative effect on sleep onset (P<0.001), sleep time (P<0.001) and sleep quality (P<0.001). CONCLUSIONS: These results indicate that ingestion of caffeinated beverages may maintain aspects of cognitive and psychomotor performance throughout the day and evening when caffeinated beverages are administered repeatedly. This study also demonstrates that day-long tea consumption produces similar alerting effects to coffee, despite lower caffeine levels, but is less likely to disrupt sleep. Other differences between tea and coffee were more subtle, and require further investigation.