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1.
Phys Rev Lett ; 127(3): 033001, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34328758

RESUMO

Isotope shifts of ^{223-226,228}Ra^{19}F were measured for different vibrational levels in the electronic transition A^{2}Π_{1/2}←X^{2}Σ^{+}. The observed isotope shifts demonstrate the particularly high sensitivity of radium monofluoride to nuclear size effects, offering a stringent test of models describing the electronic density within the radium nucleus. Ab initio quantum chemical calculations are in excellent agreement with experimental observations. These results highlight some of the unique opportunities that short-lived molecules could offer in nuclear structure and in fundamental symmetry studies.

2.
Sci Rep ; 10(1): 12306, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32704132

RESUMO

This work reports on the application of a novel electric field-ionization setup for high-resolution laser spectroscopy measurements on bunched fast atomic beams in a collinear geometry. In combination with multi-step resonant excitation to Rydberg states using pulsed lasers, the field ionization technique demonstrates increased sensitivity for isotope separation and measurement of atomic parameters over previous non-resonant laser ionization methods. The setup was tested at the Collinear Resonance Ionization Spectroscopy experiment at ISOLDE-CERN to perform high-resolution measurements of transitions in the indium atom from the [Formula: see text] and [Formula: see text] states to [Formula: see text]p [Formula: see text]P and [Formula: see text]F Rydberg states, up to a principal quantum number of [Formula: see text]. The extracted Rydberg level energies were used to re-evaluate the ionization potential of the indium atom to be [Formula: see text]. The nuclear magnetic dipole and nuclear electric quadrupole hyperfine structure constants and level isotope shifts of the [Formula: see text] and [Formula: see text] states were determined for [Formula: see text]In. The results are compared to calculations using relativistic coupled-cluster theory. A good agreement is found with the ionization potential and isotope shifts, while disagreement of hyperfine structure constants indicates an increased importance of electron correlations in these excited atomic states. With the aim of further increasing the detection sensitivity for measurements on exotic isotopes, a systematic study of the field-ionization arrangement implemented in the work was performed at the same time and an improved design was simulated and is presented. The improved design offers increased background suppression independent of the distance from field ionization to ion detection.

3.
Nature ; 581(7809): 396-400, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32461650

RESUMO

Molecular spectroscopy offers opportunities for the exploration of the fundamental laws of nature and the search for new particle physics beyond the standard model1-4. Radioactive molecules-in which one or more of the atoms possesses a radioactive nucleus-can contain heavy and deformed nuclei, offering high sensitivity for investigating parity- and time-reversal-violation effects5,6. Radium monofluoride, RaF, is of particular interest because it is predicted to have an electronic structure appropriate for laser cooling6, thus paving the way for its use in high-precision spectroscopic studies. Furthermore, the effects of symmetry-violating nuclear moments are strongly enhanced5,7-9 in molecules containing octupole-deformed radium isotopes10,11. However, the study of RaF has been impeded by the lack of stable isotopes of radium. Here we present an experimental approach to studying short-lived radioactive molecules, which allows us to measure molecules with lifetimes of just tens of milliseconds. Energetically low-lying electronic states were measured for different isotopically pure RaF molecules using collinear resonance ionisation at the ISOLDE ion-beam facility at CERN. Our results provide evidence of the existence of a suitable laser-cooling scheme for these molecules and represent a key step towards high-precision studies in these systems. Our findings will enable further studies of short-lived radioactive molecules for fundamental physics research.

4.
Eur J Dent Educ ; 20(3): 129-34, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25874344

RESUMO

BACKGROUND: Progress testing is well established as a longitudinal form of assessment in undergraduate medical programmes to measure growth in knowledge. Peninsula Dental School is the first school to use progress testing and remains the only one to do so. AIMS: To share the experience of developing progress testing in an undergraduate dental programme as a major summative assessment tool at a newly established dental school in the United Kingdom. METHODS: Data were collected for progress tests conducted from 2007 to 14. The tests were formative in the first 2 years of the programme and summative in subsequent years. Each test was based on 100 single best answer multiple-choice items with an appropriate vignette. The students chose their answer from 5 options. A score 1 mark is awarded for each correct answer, minus 0.25 for an incorrect answer and 0 for 'don't know' (DK). The standard setting for each sitting was carried out using Angoff and Hofstee methods. RESULTS: There were two tests per year with each cohort undertaking eight tests in their 4 years of study providing a total 14 test occasions. The reliability of each test for each student cohort tests was measured using Cronbach's alpha. The average reliability over 42 test/cohort combinations was 0.753 (±SD 0.08). Data analyses show growth in knowledge of dental students across successive years with the largest increase in knowledge observed between tests 1 and 5 and concomitant reduction in DK responses. CONCLUSION: This is the first study to report the establishment and use of progress testing as the principle form of written summative testing in an undergraduate dental curriculum. Progress testing is a valid and reliable tool to assess growth in knowledge longitudinally over the duration of a dental programme. Although a labour-intensive process, progress testing merits more widespread use in dental programmes.


Assuntos
Educação em Odontologia , Educação de Graduação em Medicina/normas , Avaliação Educacional/métodos , Currículo , Avaliação Educacional/estatística & dados numéricos , Humanos , Reprodutibilidade dos Testes , Faculdades de Odontologia , Estudantes de Odontologia , Reino Unido
5.
Hum Mol Genet ; 23(9): 2428-39, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24334765

RESUMO

TMEM127 is an endosome-associated tumor suppressor gene in pheochromocytomas, neuroendocrine tumors that can co-occur with renal cell carcinomas (RCCs). TMEM127 loss leads to increased mTOR signaling. However, the spectrum of tumors with TMEM127 mutation and how TMEM127 and mTOR interact in tumorigenesis remains unknown. Here, we report that germline TMEM127 mutations occur in RCCs and that some mutant proteins, unlike wild-type (WT) TMEM127, fail to cooperate with activated early endosomal GTPase, Rab5, to inhibit mTOR signaling. Tmem127-null mouse embryonic fibroblasts (MEFs) are deficient in generating early-to-late hybrid endosomes upon constitutive Rab5 activation, a defect rescued by WT, but not mutant, TMEM127. This endosomal dysfunction results in diminished mTOR colocalization with Rab5-positive vesicles. Conversely, active, lysosomal-bound mTOR is increased in Tmem127-null MEFs, which also display enhanced lysosomal biogenesis. Our data map the tumor-suppressive properties of TMEM127 to modulation of mTOR function in the endolysosome, a feature that may contribute to both pheochromocytoma and RCC pathogenesis.


Assuntos
Carcinoma de Células Renais/metabolismo , Endossomos/metabolismo , Proteínas de Membrana/metabolismo , Animais , Carcinoma de Células Renais/genética , Linhagem Celular , Endossomos/genética , Células HeLa , Humanos , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Microscopia de Fluorescência , Reação em Cadeia da Polimerase em Tempo Real
6.
Oncogene ; 30(12): 1390-401, 2011 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-21132003

RESUMO

The detection of promoter region hypermethylation and transcriptional silencing has facilitated the identification of candidate renal cell carcinoma (RCC) tumour suppressor genes (TSGs). We have used a genome-wide strategy (methylated DNA immunoprecipitation (MeDIP) and whole-genome array analysis in combination with high-density expression array analysis) to identify genes that are frequently methylated and silenced in RCC. MeDIP analysis on 9 RCC tumours and 3 non-malignant normal kidney tissue samples was performed, and an initial shortlist of 56 candidate genes that were methylated by array analysis was further investigated; 9 genes were confirmed to show frequent promoter region methylation in primary RCC tumour samples (KLHL35 (39%), QPCT (19%), SCUBE3 (19%), ZSCAN18 (32%), CCDC8 (35%), FBN2 (34%), ATP5G2 (36%), PCDH8 (58%) and CORO6 (22%)). RNAi knockdown for KLHL35, QPCT, SCUBE3, ZSCAN18, CCDC8 and FBN2 resulted in an anchorage-independent growth advantage. Tumour methylation of SCUBE3 was associated with a significantly increased risk of cancer death or relapse (P=0.0046). The identification of candidate epigenetically inactivated RCC TSGs provides new insights into renal tumourigenesis.


Assuntos
Carcinoma de Células Renais/genética , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Genes Supressores de Tumor , Neoplasias Renais/genética , Adulto , Idoso , Carcinoma de Células Renais/patologia , Feminino , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , Imunoprecipitação , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Adulto Jovem
7.
Oncogene ; 29(14): 2104-17, 2010 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-20154727

RESUMO

Promoter region hyermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty-eight genes were then selected for analysis of promoter methylation status in cell lines and primary RCC. Eight genes (BNC1, PDLIM4, RPRM, CST6, SFRP1, GREM1, COL14A1 and COL15A1) showed frequent (>30% of RCC tested) tumour-specific promoter region methylation. Hypermethylation was associated with transcriptional silencing. Re-expression of BNC1, CST6, RPRM and SFRP1 suppressed the growth of RCC cell lines and RNA interference knock-down of BNC1, SFRP1 and COL14A1 increased the growth of RCC cell lines. Methylation of BNC1 or COL14A1 was associated with a poorer prognosis independent of tumour size, stage or grade. The identification of these epigenetically inactivated candidate RCC TSGs can provide insights into renal tumourigenesis and a basis for developing novel therapies and biomarkers for prognosis and detection.


Assuntos
Carcinoma de Células Renais/genética , Metilação de DNA , Genes Supressores de Tumor , Adulto , Idoso , Sequência de Bases , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Proliferação de Células , Epigênese Genética , Perfilação da Expressão Gênica , Inativação Gênica , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Análise de Sobrevida , Adulto Jovem
8.
J Fr Ophtalmol ; 30(4): 357-64, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17486027

RESUMO

BACKGROUND: To measure changes in tear-film lipid-layer thickness (LLT) and symptoms in patients with dry eye symptoms with and without Sjögren's syndrome after using a novel device. The device is designed to promote release of meibomian sebum into the tear film by delivering latent heat to the eyelids. STUDY DESIGN: Two prospective, controlled, randomised, observer-masked, single-intervention studies. METHODS: Two independent studies were conducted in a major university hospital in the South West of England. The first study involved 24 patients with dry eye symptoms without Sjögren's [the PDE study] and the second study involved 31 patients with dry eye symptoms and Sjögren's syndrome (the SS study). The PDE study was randomised into two groups. Group I (12 patients) underwent 10 min of treatment with the activated device and Group II (12 patients) had no treatment. The SS study was similarly randomised into Group I (17 patients) and Group II (14 patients). The LLT and subjective alterations in ocular comfort of each subject were assessed prior and immediately after 5 and 30 min subsequent to the 10-min period. In the SS study, a further assessment was carried out at 60 min. RESULTS: In the PDE study, treated patients exhibited a bilateral increase of LLT at 5 min (right eyes, 1.2 levels, p<0.0005; left eyes, 1.0 levels, p<0.0005, Mann-Whitney) and at 30 min (right eyes, 0.7 levels, p<0.005; left eyes, 0.6 levels, p<0.005). Mean symptom scores improved in the treated group compared with the control group at 5 min (treatment group, +2.0; control group, +0.2; p<0.05) and 30 min (treatment group, +2.8; control group, +0.4; p<0.015). In the SS study, treated patients exhibited a bilateral increase of LLT, 5 min (right eyes, 0.5 levels, p<0.009; left eyes, 0.5 levels, p<0.005, Monte Carlo 2-tailed), 30 min (right eyes, 0.5 levels, p<0.007; left eyes 0.5 levels, p<0.002) and 60 min (right eyes, 0.3 levels, p<0.1; left eyes, 0.3 levels, p<0.05). There was no change in any of the control patients in any of the assessments. With regard to symptom scores, the mean change at 5 min measured +0.8 in the treatment group and remained relatively unchanged at +0.1 in the control group (p<0.1). At 30 min, this change measured +1.3 in the treatment group and +0.1 in the control group (p<0.03) and at 60 min, the change measured +1.5 in the treatment group and remained at +0.1 in the control group (p<0.02). CONCLUSION: Meibomian therapy with this novel device increases LLT and ocular comfort in patients with dry eye symptoms with and without Sjögren's syndrome.


Assuntos
Síndromes do Olho Seco/terapia , Hipertermia Induzida/instrumentação , Metabolismo dos Lipídeos , Glândulas Tarsais/metabolismo , Lágrimas/química , Adulto , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Método de Monte Carlo , Análise Multivariada , Estudos Prospectivos , Sebo/química , Método Simples-Cego , Síndrome de Sjogren/complicações , Síndrome de Sjogren/terapia , Estatísticas não Paramétricas
9.
J Clin Endocrinol Metab ; 91(8): 3110-6, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16720663

RESUMO

CONTEXT: Alström syndrome (AS) is a monogenic form of infancy-onset obesity and insulin resistance, caused by ALMS1 mutations. The natural history of the insulin resistance is unknown, in particular how this relates to changes in body composition. It is also unclear how ALMS1 mutations relate to the characteristic phenotype. OBJECTIVES: Our objectives were to characterize body composition and metabolic parameters, to establish ALMS1 mutation spectrum of United Kingdom AS patients, and to determine whether a genotype-phenotype correlation exists. DESIGN AND PATIENTS: We conducted a cross-sectional cohort study of 12 unrelated subjects with AS. Age-standardized body composition was assessed by anthropometry and dual-energy x-ray absorptiometry and insulin sensitivity by homeostasis model assessment. The exons and intron-exon boundaries of ALMS1 were directly sequenced. SETTING: The study was performed during the annual Alström Syndrome UK multidisciplinary screening clinic. RESULTS: AS patients have early-onset obesity, but body mass index, waist circumference, and body fat from dual-energy x-ray absorptiometry were negatively correlated with age (r = -0.37, P = 0.2; r = -0.84, P = 0.002; and r = -0.6, P = 0.05). Despite this, insulin resistance increased, demonstrated by raised fasting insulin and fall in homeostasis model assessment insulin sensitivity with age (r = -0.64, P = 0.02). ALMS1 mutations were identified in 10 of 12 patients, with a potential founder mutation in exon 16 present in five [np 10775del (C); Del3592fs/ter3597]. No genotype-phenotype correlation was observed. CONCLUSIONS: We identified mutations in ALMS1 in more than 80% of patients with no genotype-phenotype correlation. In AS, severe childhood obesity, waist circumference, and body fat decrease with age, whereas insulin resistance increases. The abdominal obesity, insulin resistance, diabetes, hypertriglyceridemia, and hypertension suggest that AS could represent a monogenic model for the metabolic syndrome.


Assuntos
Envelhecimento , Composição Corporal , Diabetes Mellitus/genética , Mutação , Obesidade/genética , Proteínas/genética , Absorciometria de Fóton , Tecido Adiposo , Adolescente , Adulto , Antropometria , Índice de Massa Corporal , Proteínas de Ciclo Celular , Criança , Pré-Escolar , Análise Mutacional de DNA , Diabetes Mellitus/fisiopatologia , Feminino , Efeito Fundador , Genótipo , Perda Auditiva Neurossensorial/genética , Humanos , Hiperinsulinismo/genética , Hipertensão/genética , Hipertrigliceridemia/genética , Resistência à Insulina/genética , Masculino , Obesidade/fisiopatologia , Fenótipo , Síndrome , Reino Unido
10.
Diabetologia ; 49(6): 1209-13, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16601972

RESUMO

AIMS/HYPOTHESIS: Alström syndrome is a rare monogenic disorder characterised by retinal dystrophy, deafness and obesity. Patients also have insulin resistance, central obesity and dyslipidaemia, thus showing similarities with type 2 diabetes. Rare mutations in the ALMS1 gene cause severe gene disruption in Alström patients; however, ALMS1 gene polymorphisms are common in the general population. The aim of our study was to determine whether common variants in ALMS1 contribute to susceptibility to type 2 diabetes in the UK population. METHODS: Direct sequencing was performed on coding regions and intron/exon boundaries of the ALMS1 gene in 30 unrelated probands with type 2 diabetes. The linkage disequilibrium (LD; D' and r2) and haplotype structure were examined for the identified variants. The common (minor allele frequency [MAF] >5%) single-nucleotide polymorphisms tagging the common haplotypes (tagged SNPs [tSNPs]) were identified and genotyped in 1985 subjects with type 2 diabetes, 2,047 control subjects and 521 families. RESULTS: We identified 18 variants with MAF between 6 and 38%. Three SNPs efficiently tagged three common haplotypes (rs1881245, rs3820700 and rs1320374). There was no association (all p > 0.05) between the tSNPs and type 2 diabetes in the case-control study and minor alleles of the tSNPs were not overtransmitted to probands with type 2 diabetes in the family study. CONCLUSIONS/INTERPRETATION: Common variations in the ALMS1 gene were not associated with type 2 diabetes in a large study of a white UK population.


Assuntos
Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , Variação Genética , Proteínas/genética , Adulto , Proteínas de Ciclo Celular , Surdez/genética , Dislipidemias/genética , Éxons , Feminino , Humanos , Resistência à Insulina/genética , Masculino , Pessoa de Meia-Idade , Obesidade/genética , Síndrome , Reino Unido , População Branca/genética
11.
Eye (Lond) ; 19(6): 657-60, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15332095

RESUMO

AIM: This study measures changes in tear film lipid layer thickness (LLT) and ocular comfort in normal subjects after 10 min use of a novel device, which delivers meibomian therapy with latent heat. The device is designed to promote the release of meibomian sebum into the tear film by delivering latent heat to the eyelids, thus thickening the lipid layer. Normal lid movements are maintained, facilitating resurfacing of the tear film. METHOD: A prospective, controlled, observer masked, single intervention trial in which 24 normal subjects were randomised into three groups. Group I underwent 10 min treatment with the activated device, Group II used the inactivated device for the same duration of time, and Group III had no intervention. The LLT of each subject was measured with a Keeler Tearscope prior and subsequent to the 10-min period. Subjective alteration in ocular comfort was also assessed. RESULTS: Seven of eight subjects (87.5%) in Group I exhibited an increase in LLT. The mean LLT in this group showed a statistically significant increase (left eyes 1.0 levels, P<0.001, right eyes 0.9 levels, P<0.003) compared to Groups II and III. Six of eight subjects (75%) using the activated device experienced subjective improvement in ocular comfort. CONCLUSION: Meibomian therapy with this device increases LLT in normal individuals. This implies a more stable tear film, reflected in subjective improvement in ocular comfort.


Assuntos
Síndromes do Olho Seco/terapia , Hipertermia Induzida/instrumentação , Bicamadas Lipídicas , Glândulas Tarsais/fisiopatologia , Lágrimas , Adulto , Síndromes do Olho Seco/fisiopatologia , Desenho de Equipamento , Pálpebras , Feminino , Humanos , Hipertermia Induzida/métodos , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Estatísticas não Paramétricas
12.
Clin Radiol ; 58(12): 971-9, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14654030

RESUMO

AIM: To determine whether reporting plain films at faster rates lead to a deterioration in accuracy. METHODS: Fourteen consultant radiologists were asked to report a total of 90 radiographs in three sets of 30. They reported the first set at the rate they would report normally and the subsequent two sets in two thirds and one half of the original time. The 90 radiographs were the same for each radiologist, however, the order was randomly generated for each. RESULTS: There was no significant difference in overall accuracy for each of the three film sets (p=0.74). Additionally no significant difference in the total number of false-negatives for each film set was detected (p=0.14). However, there was a significant decrease in the number of false-positive reports when the radiologists were asked to report at higher speeds (p=0.003). CONCLUSIONS: When reporting accident and emergency radiographs increasing reporting speed has no overall effect upon accuracy, however, it does lead to less false-positive reports.


Assuntos
Competência Clínica/normas , Fraturas Ósseas/diagnóstico por imagem , Corpo Clínico Hospitalar/normas , Radiologia/normas , Consultores , Erros de Diagnóstico , Serviço Hospitalar de Emergência/normas , Inglaterra , Humanos , Radiografia , Distribuição Aleatória , Sensibilidade e Especificidade , Filme para Raios X
13.
Hear Res ; 158(1-2): 84-94, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11506940

RESUMO

A common problem among the elderly is a difficulty in discriminating speech sounds. One factor that may contribute to this is a deterioration in the ability to process dynamic aspects of speech such as formant transitions. For the aging auditory system, this deterioration in temporal processing speed may be manifest as a deficit in encoding time-varying sounds that contain rapidly changing frequencies such as formant transitions. The primary goal of this study was to explore the neural basis of the effects of aging on temporal processing speed. To this end, single units were recorded from the auditory cortex of young and aged rats in response to frequency-modulated (FM) sweeps that changed from trial to trial in both direction and speed. Results showed that the majority of cells recorded from young rats responded most vigorously to fast and medium speeds. By contrast, the majority of units recorded from aged animals responded best to slow speeds. For preferred direction of FM sweep, similar results were observed for both age groups, namely, approximately half of the units exhibited a direction-selective response. The results of the present study demonstrate an age-related decrease in the rate of change of frequency that can be processed by the auditory cortex.


Assuntos
Envelhecimento/fisiologia , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Percepção do Tempo/fisiologia , Animais , Masculino , Ratos , Ratos Long-Evans
14.
J Adv Nurs ; 30(4): 785-95, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10520090

RESUMO

Nurse education has been transformed over the last decade and continuing change is likely. Nurse educators are responsible for meeting the quality assurance standards of local stakeholders and student retention and progress are important aspects of this process. As part of a monitoring exercise, an enquiry was set up to review pre-registration selection and recruitment strategies and to establish if there were any significant relationships between the characteristics of pre-registration diploma entrants and their academic achievement or completion rates. A multi-factorial tree-based technique was used for this purpose. This is one of the first British studies to consider both academic performance and completion rates for pre-registration diploma students. Four cohorts (N = 355) were studied. There was marked heterogeneity in student characteristics with a wide age distribution, a significant proportion of mature entrants with previous care experience, and considerable diversity in terms of education. Education and age were significant predictors of academic achievement: entrants with a minimum of two A levels and mature women with recent study experience did particularly well. Younger recruits with modest educational qualifications on entry performed less well in their assessments of theoretical knowledge. Younger students tended to leave more regularly, and well-qualified entrants showed a greater tendency to complete, although these relationships were not statistically significant. Multi-factorial analysis demonstrated that organisational and course characteristics have a conjoint influence on course outcomes. Although the study is concerned with Project 2000 in the United Kingdom, there are lessons to be drawn concerning the selection and support of non-traditional recruits into nursing.


Assuntos
Logro , Bacharelado em Enfermagem , Estudantes de Enfermagem/psicologia , Adulto , Fatores Etários , Estudos de Coortes , Avaliação Educacional , Inglaterra , Análise Fatorial , Feminino , Previsões , Humanos , Evasão Escolar
15.
Hear Res ; 123(1-2): 27-30, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9745952

RESUMO

Responses to frequency modulated (FM) sweeps were recorded in rat primary auditory cortex. Forty-four percent of the cells were direction-selective. For speed selectivity, the majority of the cells preferred faster sweeps. The results suggest that rat auditory cortex may be used for processing communication signals of their predators or for detecting spectral changes in acoustic signals.


Assuntos
Estimulação Acústica , Córtex Auditivo/fisiologia , Animais , Masculino , Neurônios/fisiologia , Ratos
16.
Eur J Clin Nutr ; 51(11): 778-81, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9368813

RESUMO

OBJECTIVE: To examine the relationship between fat preference, dietary intake data and body composition in children. SUBJECT AND METHODS: Subjects studied were 88 children aged 9-12 y from two elementary schools in Ohio. Measures for dietary intake and body composition were obtained by 3 day diet records, anthropometrics, triceps and subscapular skinfolds. Fat preference data was assessed by hedonic rating of high and low fat snack foods. RESULTS: Data indicate that children who preferred the high fat snack items had high dietary fat intakes (r = 0.57, P < 0.05). Tricep skinfold measurement and BMI correlated positively with high fat food preferences (r = 0.51 and r = 0.46 P < 0.05). CONCLUSIONS: These data suggest preference for high fat foods may occur due to diet composition and that increased adiposity may be associated with higher relative fat intakes.


Assuntos
Composição Corporal , Gorduras na Dieta/administração & dosagem , Preferências Alimentares , Criança , Inquéritos sobre Dietas , Ingestão de Energia , Feminino , Humanos , Masculino
17.
Eur J Cancer Prev ; 6(1): 11-9, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9161807

RESUMO

This study assessed whether there is any variation in the incidence of haematological malignancies between geographical areas of differing water supplies in the South West peninsula of the United Kingdom (1984 to 1988 inclusive). The possibility of correlations existing between variation in water quality and variation in the incidence of haematological malignancies was examined. Haematological incidence data, taken from the Leukaemia Research Fund's Data Collection Study, were mapped into 46 geographical areas of differing water supply. The distribution of the mapped cases was then tested for homogeneity using the Potthoff and Whittinghill (1966) test score. The age-adjusted incidence ratios calculated during the heterogeneity testing were examined for correlations with water quality indicators using correlation and stepwise regression. Significant heterogeneity in the incidence rates among water supply areas was observed for two groups of disease-acute leukaemias and myeloproliferative disorders. Three water quality indicators-pH, nitrate concentration and aluminium concentration-varied considerably over the study period. Significant correlations were observed between the standardized incidence ratios of five disease categories and some water quality indicators, especially aluminium and trihalomethane concentrations. The standardized incidence ratios of some haematological malignancies differed between geographical areas of water supply in South West England, and the evidence suggests that this variation may be associated with variation in water quality indicators. Although this lends support to similar findings in the United States of America, the pattern of correlations are affected by disease latency and statistical methodology.


Assuntos
Neoplasias Hematológicas/epidemiologia , Leucemia/epidemiologia , Poluição Química da Água/efeitos adversos , Abastecimento de Água/normas , Inglaterra/epidemiologia , Água Doce/análise , Água Doce/química , Guias como Assunto , Neoplasias Hematológicas/etiologia , Humanos , Incidência , Leucemia/etiologia , Análise de Regressão , Fatores de Risco , Poluição Química da Água/análise , Organização Mundial da Saúde
18.
Dermatol Surg ; 22(11): 955-9, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9063511

RESUMO

BACKGROUND: Treatment of hypertrophic scars can be difficult for both patients and physicians. Silicone-containing gel dressings have been reported to be an effective alternative treatment for hypertrophic scars, yet the mechanism of action of these dressings is unknown. OBJECTIVE: To determine whether silicone is an essential factor in the treatment of hypertrophic scars and investigate the effects of occlusive dressing therapy on the expression of key wound healing mediators. METHODS: A pilot paired comparison, nonrandomized study was conducted comparing a silicone gel sheeting (Silastic [SGS]) with a hydrogel dressing (ClearSite). The effects of the dressings were compared side by side in the treatment of 15 hypertrophic scars at both the clinical and molecular levels through the use of reverse transcriptase/polymerase chain reaction to evaluate effects on the expression of interleukin 8 (IL-8), basic fibroblast growth factor (bFGF), granulocyte-macrophage colony-stimulating factor (GMCSF), epidermal growth factor (EGF), transforming growth factor beta (TGF-beta), and fibronectin. RESULTS: Comparable clinical improvement of the hypertrophic scars was obtained with both dressings. Treatment of hypertrophic scars resulted in increased mean levels of IL-8, bFGF, and GMCSF mRNA; while mean TGF beta and fibronectin mRNAs decreased after treatment with both dressings. Comparison between the two dressings revealed significant changes in IL-8 and fibronectin mRNA levels after treatment with ClearSite, while only fibronectin changes were significant after treatment with SGS with respect to normal skin. Only ClearSite induced significant changes in IL-8 and bFGF levels when untreated scars were compared with posttreatment lesions, suggesting that the hydrogel augments collagenolysis via promotion of inflammation. CONCLUSIONS: This study demonstrates that silicone is not a necessary component of occlusive dressings in the treatment of hypertrophic scars. The pathogenesis of hypertrophic scars is further elucidated by demonstrating that there is molecular evidence for extensive connective tissue remodeling occurring during occlusive dressing therapy.


Assuntos
Cicatriz Hipertrófica/terapia , Citocinas/genética , Curativos Oclusivos , RNA Mensageiro/genética , Silicones , Adulto , Idoso , Cicatriz Hipertrófica/genética , Cicatriz Hipertrófica/patologia , Colágeno/metabolismo , Tecido Conjuntivo/metabolismo , Tecido Conjuntivo/patologia , Fator de Crescimento Epidérmico/genética , Fator 2 de Crescimento de Fibroblastos/genética , Fibronectinas/genética , Géis , Regulação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Humanos , Inflamação , Interleucina-8/genética , Pessoa de Meia-Idade , Projetos Piloto , Polietilenoglicóis , Reação em Cadeia da Polimerase , Poliuretanos , RNA Mensageiro/análise , Elastômeros de Silicone , Pele/metabolismo , Pele/patologia , Fator de Crescimento Transformador beta/genética , Cicatrização/genética
19.
Gut ; 38(6): 905-10, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8984031

RESUMO

BACKGROUND: Simple criteria are needed to predict which patients with severe ulcerative colitis will respond poorly to intensive medical treatment and require colectomy. AIMS: To find out if the early pattern of change in inflammatory markers or other variables could predict the need for surgery and to evaluate the outcome of medical treatment during one year follow up. PATIENTS: 51 consecutive episodes of severe colitis (Truelove and Witts criteria) affecting 49 patients admitted to John Radcliffe Hospital, Oxford. METHODS: Prospective study monitoring 36 clinical, laboratory, and radiographic variables. All episodes treated with intravenous and rectal hydrocortisone and 14 of 51 with cyclosporine. RESULTS: Complete response in 21 episodes (< or = 3 stools on day 7, without visible blood), incomplete response in 15 (> 3 stools or visible blood on day 7, but no colectomy), and colectomy on that admission in 15. During the first five days, stool frequency and C reactive protein (CRP) distinguished between outcomes (p < 0.00625, corrected for multiple comparisons) irrespective of whether patients or the number of episodes were analysed. It could be predicted on day 3, that 85% of patients with more than eight stools on that day, or a stool frequency between three and eight together with a CRP > 45 mg/l, would require colectomy. For patients given cyclosporine, four of 14 avoided colectomy but two continued to have symptoms. After admission, complete responders remained in remission for a median nine months and had a 5% chance of colectomy. Incomplete responders had a 60% chance of continuous symptoms and 40% chance of colectomy. CONCLUSIONS: After three days intensive treatment, patients with frequent stools (> 8/day), or raised CRP (> 45 mg/l) need to be identified, as most will require colectomy on that admission. The role of cyclosporine for treating severe colitis has yet to be defined. After seven days' treatment, patients with > 3 stools/day of visible blood have a 60% chance of continuous symptoms and 40% chance of colectomy in the following months.


Assuntos
Proteína C-Reativa/análise , Colite Ulcerativa/terapia , Adulto , Idoso , Biomarcadores , Colectomia , Colite Ulcerativa/diagnóstico por imagem , Colite Ulcerativa/cirurgia , Ciclosporina/uso terapêutico , Defecação , Fezes , Feminino , Hospitalização , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Radiografia
20.
J Am Diet Assoc ; 96(1): 35-8, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8537567

RESUMO

OBJECTIVE: Dietary intake, physical activity, and serum lipid levels of college students living on and off campus were compared. DESIGN: Subjects completed a questionnaire regarding lifestyle factors and a 3-day food record. Lipid levels were determined. SUBJECTS: College students enrolled in an introductory nutrition class. MAIN OUTCOME MEASURES: Energy and nutrient intakes and serum lipid levels. STATISTICAL ANALYSES PERFORMED: Analysis of variance and Student's t tests were used to determine differences in energy and nutrient intakes and serum lipid levels between men and women living on and off campus; chi 2 analysis was used to determine whether there were associations between residence and lifestyle factors; stepwise multiple regression analysis was used to investigate relationships among serum lipid levels, nutrient intakes, and exercise levels. RESULTS: Of the 104 participants, 81% were women and 19% were men; 51% lived on campus. In women, there was a statistically significant difference in age based on residence. Reported percentage of energy from protein was significantly higher in subjects living off campus. Serum triglyceride level and the ratio of total cholesterol to high-density lipoprotein were also significantly higher in students living off campus. APPLICATIONS/CONCLUSIONS: Residence may affect serum lipid levels; living arrangements influence lifestyle factors such as food choices, nutrient content of the diet, and activity patterns. University foodservice directors are challenged to offer low-fat foods that students will choose to eat. Nutrition education is important for all students because their lifestyle may predispose them to development of chronic disease.


Assuntos
Ingestão de Alimentos , Exercício Físico , Lipídeos/sangue , Características de Residência , Estudantes , Adolescente , Adulto , Análise de Variância , Índice de Massa Corporal , Registros de Dieta , Ingestão de Energia , Metabolismo Energético , Feminino , Humanos , Masculino , Caracteres Sexuais , Inquéritos e Questionários
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