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1.
Prostate ; 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38704755

RESUMO

BACKGROUND: Prebiopsy magnetic resonance imaging (MRI) increases the detection rate of clinically significant prostate cancer (csPCa). Prostate-specific membrane antigen-positron emission tomography/computed tomography (PSMA PET/CT) maximum standardized uptake value (SUVmax) of the prostate may offer additional value in predicting the likelihood of csPCa in biopsy. METHODS: A single-center cohort study involving patients with biopsy-proven PCa who underwent both MRI and PSMA PET/CT between 2020 and 2021. Logistic regression models were developed for International Society of Urological Pathology (ISUP) Grade Group (GG) ≥ 2 and GG ≥ 3 using noninvasive prebiopsy parameters: age, (log-)prostate-specific antigen (PSA) density, PI-RADS 5 lesion presence, extraprostatic extension (EPE) on MRI, and SUVmax of the prostate. Models with and without SUVmax were compared using Likelihood ratio tests and area under the curve (AUC). DeLong's test was used to compare the AUCs. RESULTS: The study included 386 patients, with 262 (68%) having ISUP GG ≥ 2 and 180 (47%) having ISUP GG ≥ 3. Including SUVmax significantly improved both models' goodness of fit (p < 0.001). The GG ≥ 2 model had a higher AUC with SUVmax 89.16% (95% confidence interval [CI]: 86.06%-92.26%) than without 87.34% (95% CI: 83.93%-90.76%) (p = 0.026). Similarly, the GG ≥ 3 model had a higher AUC with SUVmax 82.51% (95% CI: 78.41%-86.6%) than without 79.33% (95% CI: 74.84%-83.83%) (p = 0.003). The SUVmax inclusion improved the GG ≥ 3 model's calibration at higher probabilities. CONCLUSION: SUVmax of the prostate on PSMA PET/CT potentially improves diagnostic accuracy in predicting the likelihood of csPCa in prostate biopsy.

2.
Eur Urol Oncol ; 7(2): 204-210, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37296065

RESUMO

BACKGROUND: The use of clinical parameters, including prebiopsy magnetic resonance imaging (MRI), to decide between active surveillance (AS) and active therapy for prostate cancer (PCa) leads to imperfect selection. Additional prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) imaging may improve risk stratification. OBJECTIVE: To study risk stratification and patient selection for AS with the addition of PSMA PET/CT to standard practice. DESIGN, SETTING, AND PARTICIPANTS: A single-centre prospective cohort study (NL69880.100.19) enrolled patients recently diagnosed with PCa who started AS. At diagnosis, all participants had undergone prebiopsy MRI and targeted biopsy for visualised lesions. Patients underwent an additional [68Ga]-PSMA PET/CT and targeted biopsy of all PSMA lesions with a maximum standardised uptake value (SUVmax) of ≥4 not covered by previous biopsies. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was the number needed to scan (NNS) to detect one patient with upgrading. The study was powered to detect an NNS of 10. Regarding secondary outcomes, univariate logistic regressions analyses were performed on all patients and on the patients who received additional PSMA targeted biopsies on the likelihood of upgrading. RESULTS AND LIMITATIONS: A total of 141 patients were included. Additional PSMA targeted biopsies were performed in 45 (32%) patients. In 13 (9%) patients, upgrading was detected: nine grade group (GG) 2, two GG 3, one GG 4, and one GG 5. The NNS was 11 (95% confidence interval 6-18). Of all participants, PSMA PET/CT and targeted biopsies yielded upgrading most frequently in patients with negative MRI (Prostate Imaging Reporting and Data System [PI-RADS] 1-2). Of patients who received additional PSMA targeted biopsies, upgrading was most frequently found in those with higher prostate-specific antigen density and negative MRI. Limitations included the lack of comparison with standard repeat biopsy, no central review of MRI, and possibility of biopsy sampling error. CONCLUSIONS: PSMA PET/CT can further improve PCa risk stratification and selection for AS patients diagnosed after MRI and targeted biopsies. PATIENT SUMMARY: Prostate-specific membrane antigen positron emission tomography/computed tomography and additional targeted prostate biopsies can identify more aggressive prostate cancer cases previously missed in patients recently started with expectant management for favourable-risk prostate cancer.


Assuntos
Radioisótopos de Gálio , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/terapia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Próstata/diagnóstico por imagem , Próstata/patologia , Imageamento por Ressonância Magnética , Estudos Prospectivos , Conduta Expectante
3.
Cancers (Basel) ; 15(19)2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37835494

RESUMO

BACKGROUND: Diagnostic pathways for prostate cancer (PCa) balance detection rates and burden. MRI impacts biopsy indication and strategy. METHODS: A prospectively collected cohort database (N = 496) of men referred for elevated PSA and/or abnormal DRE was analyzed. All underwent biparametric MRI (3 Tesla scanner) and ERSPC prostate risk-calculator. Indication for biopsy was PIRADS ≥ 3 or risk-calculator ≥ 20%. Both targeted (cognitive-fusion) and systematic cores were combined. A hypothetical full-MRI-based pathway was retrospectively studied, omitting systematic biopsies in: (1) PIRADS 1-2 but risk-calculator ≥ 20%, (2) PIRADS ≥ 3, receiving targeted biopsy-cores only. RESULTS: Significant PCa (GG ≥ 2) was detected in 120 (24%) men. Omission of systematic cores in cases with PIRADS 1-2 but risk-calculator ≥ 20%, would result in 34% less biopsy indication, not-detecting 7% significant tumors. Omission of systematic cores in PIRADS ≥ 3, only performing targeted biopsies, would result in a decrease of 75% cores per procedure, not detecting 9% significant tumors. Diagnosis of insignificant PCa dropped by 52%. PCa undetected by targeted cores only, were ipsilateral to MRI-index lesions in 67%. CONCLUSIONS: A biparametric MRI-guided PCa diagnostic pathway would have missed one out of six cases with significant PCa, but would have considerably reduced the number of biopsy procedures, cores, and insignificant PCa. Further refinement or follow-up may identify initially undetected cases. Center-specific data on the performance of the diagnostic pathway is required.

4.
World J Urol ; 41(11): 3357-3366, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37755520

RESUMO

OBJECTIVE: To evaluate the proportions of detected prostate cancer (PCa) and clinically significant PCa (csPCa), as well as identify clinical predictors of PCa, in patients with PI-RADS > = 3 lesion at mpMRI and initial negative targeted and systematic biopsy (initial biopsy) who underwent a second MRI and a re-biopsy. METHODS: A total of 290 patients from 10 tertiary referral centers were included. The primary outcome measures were the presence of PCa and csPCa at re-biopsy. Logistic regression analyses were performed to evaluate predictors of PCa and csPCa, adjusting for relevant covariates. RESULTS: Forty-two percentage of patients exhibited the presence of a new lesion. Furthermore, at the second MRI, patients showed stable, upgrading, and downgrading PI-RADS lesions in 42%, 39%, and 19%, respectively. The interval from the initial to repeated mpMRI and from the initial to repeated biopsy was 16 mo (IQR 12-20) and 18 mo (IQR 12-21), respectively. One hundred and eight patients (37.2%) were diagnosed with PCa and 74 (25.5%) with csPCa at re-biopsy. The presence of ASAP on the initial biopsy strongly predicted the presence of PCa and csPCa at re-biopsy. Furthermore, PI-RADS scores at the first and second MRI and a higher number of systematic biopsy cores at first and second biopsy were independent predictors of the presence of PCa and csPCa. Selection bias cannot be ruled out. CONCLUSIONS: Persistent PI-RADS ≥ 3 at the second MRI is suggestive of the presence of a not negligible proportion of csPca. These findings contribute to the refinement of risk stratification for men with initial negative MRI-TBx.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Próstata , Masculino , Humanos , Imageamento por Ressonância Magnética , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Biópsia Guiada por Imagem , Centros de Atenção Terciária , Estudos Retrospectivos
5.
Sensors (Basel) ; 23(2)2023 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-36679516

RESUMO

In recent years, employment in sedentary occupations has continuously risen. Office workers are more prone to prolonged static sitting, spending 65−80% of work hours sitting, increasing risks for multiple health problems, including cardiovascular diseases and musculoskeletal disorders. These adverse health effects lead to decreased productivity, increased absenteeism and health care costs. However, lack of regulation targeting these issues has oftentimes left them unattended. This article proposes a smart chair system, with posture and electrocardiography (ECG) monitoring modules, using an "invisible" sensing approach, to optimize working conditions, without hindering everyday tasks. For posture classification, machine learning models were trained and tested with datasets composed by center of mass coordinates in the seat plane, computed from the weight measured by load cells fixed under the seat. Models were trained and evaluated in the classification of five and seven sitting positions, achieving high accuracy results for all five-class models (>97.4%), and good results for some seven-class models, particularly the best performing k-NN model (87.5%). For ECG monitoring, signals were acquired at the armrests covered with conductive nappa, connected to a single-lead sensor. Following signal filtering and segmentation, several outlier detection methods were applied to remove extremely noisy segments with mislabeled R-peaks, but only DBSCAN showed satisfactory results for the ECG segmentation performance (88.21%) and accuracy (90.50%).


Assuntos
Doenças Musculoesqueléticas , Postura , Humanos , Postura/fisiologia , Ocupações , Postura Sentada , Eletrocardiografia
6.
Eur Urol Open Sci ; 46: 30-32, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36310760

RESUMO

We describe a <36-h superfast diagnostic pathway for men at risk of prostate cancer (PCa) that was initiated in our centre in March 2022. Patients are scheduled to undergo a repeat prostate-specific antigen blood test, magnetic resonance imaging, a urology consultation, and, if indicated, prostate biopsies in a single morning. The histopathology report is available the next day, after which the biopsy results and treatment options are discussed via a telephone consultation. The project has included 122 patients so far. With a reduction to only one hospital visit per patient and just five appointments (4%) cancelled so far, this timely pathway seems to be efficient from a patient perspective. In addition, reducing the waiting time until histopathology diagnosis could decrease the anxiety and depression that patients may experience during the diagnostic workup for PCa. Therefore, we believe that this fast-track diagnostic pathway could be incorporated in the future European standard of care, bringing PCa care in line with other malignancies such as breast cancer. Patient summary: We describe a superfast diagnostic pathway for men at risk of prostate cancer. So far, this strategy seems to be an efficient and appropriate way to shorten time to diagnosis and to reduce the number of hospital visits for patients.

7.
Eur Urol Open Sci ; 44: 30-32, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36046616

RESUMO

Magnetic resonance imaging (MRI) has resulted in a reduction in the number of patients indicated for prostate biopsy. Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has recently shown additional value in detecting clinically significant prostate cancer (csPCa). Combining these imaging modalities allows such specific prediction of the presence of csPCa that the need for histological confirmation may be obsolete. We retrospectively analyzed PSMA PET/CT scans performed in the primary staging of PCa in the past 2 yr in our center (n = 451). All 74 patients with a PSMA ligand maximum standardized uptake value (SUVmax) of ≥16 had csPCa (grade group ≥2). Of the 185 patients with a combination of a Prostate Imaging-Reporting and Data System score ≥4 and SUVmax ≥8, 98% had csPCa. A nomogram combining predictive factors should be developed to identify patients in whom biopsy could theoretically be avoided. Nevertheless, biopsy will remain indispensable in patients with indefinite risk of csPCa and can provide important additional information. Patient summary: Using patient data from our center, we found that addition of a special type of scan based on prostate-specific membrane antigen could help in the diagnosis of clinically significant prostate cancer without the need for prostate biopsy. Direct therapy without biopsy confirmation of cancer might be possible for a highly select group of patients.

8.
Foods ; 10(5)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064616

RESUMO

The interest in developing reliable wine authenticity schemes is a hot-topic, especially for wines with recognized added-value. In order to accomplish this goal, two dimensions need to be considered: the grapevine variety determination and the geographical provenance. The aim of this study was to develop a multidisciplinary approach applicable to wines from the sub region Melgaço and Monção of the demarcated Vinho Verde region and from the demarcated Douro region. The proposed scheme consists on the use of DNA-based assays to detect Single Nucleotide Polymorphisms (SNPs) on three genes of the anthocyanin pathway (UFGT, F3H and LDOX) coupled with High-resolution melting (HRM) analysis aiming the varietal identification. The Alvarinho wines revealed to have the same haplotype using this marker set, demonstrating its applicability for genetic identification. In addition, to assess their geographical provenance, a multi-elemental approach using Sr and Pb isotopic ratios of wine, soil and bedrock samples was used. The isotopic data suggest a relation between Sr and Pb uptake by vine roots and soil's texture and clay content, rather than with the whole rock's isotopic ratios, but also highlights the potential of a discriminating method based on the combination of selected isotopic signatures.

9.
Sci Rep ; 8(1): 5850, 2018 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-29643453

RESUMO

The wine sector requires quick and reliable methods for Vitis vinifera L. varietal identification. The number of V. vinifera varieties is estimated in about 5,000 worldwide. Single Nucleotide Polymorphisms (SNPs) represent the most basic and abundant form of genetic sequence variation, being adequate for varietal discrimination. The aim of this work was to develop DNA-based assays suitable to detect SNP variation in V. vinifera, allowing varietal discrimination. Genotyping by sequencing allowed the detection of eleven SNPs on two genes of the anthocyanin pathway, the flavanone 3-hydroxylase (F3H, EC: 1.14.11.9), and the leucoanthocyanidin dioxygenase (LDOX, EC 1.14.11.19; synonym anthocyanidin synthase, ANS) in twenty V. vinifera varieties. Three High Resolution Melting (HRM) assays were designed based on the sequencing information, discriminating five of the 20 varieties: Alicante Bouschet, Donzelinho Tinto, Merlot, Moscatel Galego and Tinta Roriz. Sanger sequencing of the HRM assay products confirmed the HRM profiles. Three probes, with different lengths and sequences, were used as bio-recognition elements in an optical biosensor platform based on a long period grating (LPG) fiber optic sensor. The label free platform detected a difference of a single SNP using genomic DNA samples. The two different platforms were successfully applied for grapevine varietal identification.


Assuntos
Técnicas Biossensoriais , Técnicas de Genotipagem/métodos , Proteínas de Plantas/genética , Vitis/genética , DNA de Plantas/isolamento & purificação , Oxigenases de Função Mista/genética , Oxigenases/genética , Polimorfismo de Nucleotídeo Único , Reação em Cadeia da Polimerase em Tempo Real/métodos , Análise de Sequência de DNA/métodos
10.
Food Res Int ; 103: 170-181, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29389603

RESUMO

Olive oil and wine production have a worldwide economic impact. Their market reliability is under great concern because of the increasing number of fraud and adulteration attempts. The need for a traceability system in all its extension is crucial particularly for the cases of olive oils and wines with certified labels, in which only a limited number of olives and grapevine varieties, respectively, are allowed in a restricted well-defined geographical area. Molecular markers have been vastly applied to the food sector, and in particular High-Resolution DNA Melting technology has been successfully applied for olive oil and wine authentication, as part of the traceability system. In this review, the applications of HRM and their usefulness for this sector considering, Safety, Security and Authenticity will be reviewed. A broad overview of the HRM technique will be presented, focusing on the aspects that are crucial for its success, in particular the new generation of fluorescent dsDNA dyes used for amplicon detection and quantification, and the data analysis. A brief outlook on the olive oil and wine authenticity procedures, based on new DNA technology advances, and in which way this may influence the future establishment of a traceability system will be discussed.


Assuntos
Certificação/normas , DNA de Plantas/genética , Abastecimento de Alimentos/normas , Fraude/prevenção & controle , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Olea/genética , Azeite de Oliva/normas , Reação em Cadeia da Polimerase/métodos , Vitis/genética , Vinho/normas , Marcadores Genéticos , Fidelidade a Diretrizes , Guias como Assunto , Olea/classificação , Azeite de Oliva/classificação , Reprodutibilidade dos Testes , Vitis/classificação , Vinho/classificação
11.
Pacing Clin Electrophysiol ; 40(5): 578-584, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28156009

RESUMO

BACKGROUND: Idiopathic ventricular fibrillation (iVF) is diagnosed in cardiac arrest survivors without an identifiable cause. Data regarding the health-related quality of life (HRQoL) in iVF patients are lacking. The purpose of this study was to investigate the HRQoL of iVF patients and to compare it to patients with an implantable cardioverter defibrillator (ICD) diagnosed with an underlying disease and healthy subjects. METHODS: In 61 iVF patients with an ICD (iVF-ICD) and 59 ICD patients with a diagnosis (diagnosis-ICD), HRQoL was assessed using the 12-item Short-Form Health Survey (SF-12), the EuroQoL-5 dimensions (EQ-5D), the 9-item Patient Health Questionnaire, and the ICD Patient Concerns (ICDC) Questionnaire. In addition, 860 healthy subjects completed the SF-12. RESULTS: IVF-ICD showed similar SF-12 physical summary scores compared with diagnosis-ICD patients (50.8 [interquartile range (IQR) = 42.1-53.9] vs 54.1 [IQR = 46.5-58.3]; P = 0.080) and healthy subjects (51.8 [IQR = 45.9-54.1]; P = 0.691). The mental summary score was impaired in iVF-ICD patients compared with diagnosis-ICD patients (45.9 [IQR = 40.7-49.4] vs 54.6 [IQR = 46.0-57.9]; P < 0.001) and healthy subjects (47.7 [IQR = 43.0-50.4]; P = 0.027). Scores on all five EQ-5D domains were similar between iVF-ICD patients and diagnosis-ICD patients, as well as symptoms of severe depression (19% vs 12%; P = 0.101). ICD concerns were similar between iVF-ICD and diagnosis-ICD patients (ICDC-scores 2 vs 2; P = 0.494). CONCLUSIONS: Data suggest that there is a reduced mental HRQoL in patients with iVF compared to other cardiac arrest survivors. Screening and treatment of psychological distress should therefore be considered in iVF patients.


Assuntos
Desfibriladores Implantáveis/estatística & dados numéricos , Depressão/epidemiologia , Cardioversão Elétrica/psicologia , Cardioversão Elétrica/estatística & dados numéricos , Qualidade de Vida/psicologia , Fibrilação Ventricular/prevenção & controle , Fibrilação Ventricular/psicologia , Adulto , Idoso , Causalidade , Comorbidade , Efeitos Psicossociais da Doença , Depressão/psicologia , Feminino , Humanos , Masculino , Saúde Mental/estatística & dados numéricos , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Prevalência , Fatores de Risco , Resultado do Tratamento , Fibrilação Ventricular/epidemiologia
12.
Food Chem ; 218: 40-46, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27719927

RESUMO

The generalization ability of hyperspectral imaging combined with neural networks (NN) in estimating pH and anthocyanin content during ripening was evaluated for vintages and varieties not employed in the NN creation. A NN, from a previously published work, trained with grape samples of Touriga Franca (TF) variety harvested in 2012 was tested with TF from 2013 and two new varieties, Touriga Nacional (TN) and Tinta Barroca (TB) from 2013. Each sample contained a small number of whole berries. The present work results suggest that, under certain conditions, it might be possible for the NN to provide for new vintages and varieties results comparable to those of the vintages and varieties employed in the NN training. For pH, the results are state-of-the-art for the new vintage and varieties tested. For anthocyanin, generalization is bad for TB from 2013 but presents state-of-the-art absolute percentage error for TF and TN from 2013.


Assuntos
Antocianinas/análise , Redes Neurais de Computação , Vitis/química , Vinho/análise , Análise de Alimentos , Concentração de Íons de Hidrogênio
13.
Food Chem ; 216: 80-6, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27596395

RESUMO

Wine authenticity methods are in increasing demand mainly in Denomination of Origin designations. The DNA-based methodologies are a reliable means of tracking food/wine varietal composition. The main aim of this work was the study of High Resolution Melting (HRM) application as a screening method for must and wine authenticity. Three sample types (leaf, must and wine) were used to validate the three developed HRM assays (Vv1-705bp; Vv2-375bp; and Vv3-119bp). The Vv1 HRM assay was only successful when applied to leaf and must samples. The Vv2 HRM assay successfully amplified all sample types, allowing genotype discrimination based on melting temperature values. The smallest amplicon, Vv3, produced a coincident melting curve shape in all sample types (leaf and wine) with corresponding genotypes. This study presents sensitive, rapid and efficient HRM assays applied for the first time to wine samples suitable for wine authenticity purposes.


Assuntos
DNA de Plantas/genética , Folhas de Planta/metabolismo , Reação em Cadeia da Polimerase/métodos , Vitis/genética , Vinho/análise , Genótipo , Técnicas de Diagnóstico Molecular , Desnaturação de Ácido Nucleico , Vitis/classificação
14.
Biosens Bioelectron ; 84: 30-6, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26456729

RESUMO

A label-free fiber optic biosensor based on a long period grating (LPG) and a basic optical interrogation scheme using off the shelf components is used for the detection of in-situ DNA hybridization. A new methodology is proposed for the determination of the spectral position of the LPG mode resonance. The experimental limit of detection obtained for the DNA was 62±2nM and the limit of quantification was 209±7nM. The sample specificity was experimentally demonstrated using DNA targets with different base mismatches relatively to the probe and was found that the system has a single base mismatch selectivity.


Assuntos
Técnicas Biossensoriais/instrumentação , DNA/análise , Tecnologia de Fibra Óptica/instrumentação , Hibridização In Situ/instrumentação , Pareamento Incorreto de Bases , Técnicas Biossensoriais/métodos , DNA/genética , Desenho de Equipamento , Tecnologia de Fibra Óptica/métodos , Hibridização In Situ/métodos , Limite de Detecção , Modelos Moleculares
15.
J Agric Food Chem ; 63(41): 9165-74, 2015 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-26422991

RESUMO

Vitis vinifera L. is a species with a large number of varieties, which differ in terms of anthocyanin content. The genes involved in the anthocyanin biosynthesis pathway have a direct effect in the anthocyanin profile of each variety, being potentially interesting for varietal identification. The current study aimed at the design of an assay suitable for the discrimination of the largest number of grapevine varieties. Two genes of the anthocyanin pathway, chalcone isomerase (CHI) and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT), were sequenced in 22 grapevine varieties. The CHI gene presented 5 SNPs within the sequence. A total of 58 SNPs and 1 INDEL were found among the UFGT gene, allowing the discrimination of 18 different genotypes within the 22 grapevine varieties. A HRM assay designed for UFGT, containing 704 bp, produced differentiated melting curves for each of the 18 haplotypes. The developed HRM assay is efficient in grapevine varietal discrimination.


Assuntos
Técnicas Genéticas , Glucosiltransferases/genética , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Uridina Difosfato Glucose/metabolismo , Vitis/genética , DNA de Plantas/química , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Genótipo , Glucosiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Temperatura de Transição , Vitis/enzimologia , Vitis/metabolismo
16.
Disabil Rehabil ; 33(6): 475-85, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20594034

RESUMO

The aim of this study is to characterise the accessibility of all Public Portuguese Universities' homepages and the support services they offer to disabled students. We employed two different online automatic tools: using the 'eXaminator' to determine the conformance of websites to checkpoints; using 'HERA' to identify any automatically detectable errors or checkpoints. The choice of these tools was according to the Portuguese Government recommendation, to public in general, as the ones best suited to perform accessibility check-ups. Thus, we used those tools to present a brief characterisation of the sites' accessibility. The data collection took place in 2007, 2008 and 2009 to identify differences. Following this work, we chose all the sites that stated to have specific services to support disabled students and made a detailed analysis to: (a) identify existing university services to disabled students; (b) identify possible relations among the accessibility' scores in the universities that offer services to disabled students. The main results of this study were as follows: schools overall accessibility of the webpage were not acceptable and only 12.5% sites had information regarding supporting services to disabled students. The data collected identified an overall web accessibility improvement during the 2007-2008, followed by a stabilisation of the results.


Assuntos
Acesso à Informação , Pessoas com Deficiência , Internet , Estudantes , Universidades , Humanos , Modelos Lineares , Portugal
17.
Yeast ; 24(8): 625-36, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17534867

RESUMO

One hundred isolates of the commercial Saccharomyces cerevisiae strain Zymaflore VL1 were recovered from spontaneous fermentations carried out with grapes collected from vineyards located close to wineries in the Vinho Verde wine region of Portugal. Isolates were differentiated based on their mitochondrial DNA restriction patterns and the evaluation of genetic polymorphisms was carried out by microsatellite analysis, interdelta sequence typing and pulsed-field gel electrophoresis (PFGE). Genetic patterns were compared to those obtained for 30 isolates of the original commercialized Zymaflore VL1 strain. Among the 100 recovered isolates we found a high percentage of chromosomal size variations, most evident for the smaller chromosomes III and VI. Complete loss of heterozygosity was observed for two isolates that had also lost chromosomal heteromorphism; their growth and fermentative capacity in a synthetic must medium was also affected. A considerably higher number of variant patterns for interdelta sequence amplifications was obtained for grape-derived strains compared to the original VL1 isolates. Our data show that the long-term presence of strain VL1 in natural grapevine environments induced genetic changes that can be detected using different fingerprinting methods. The observed genetic changes may reflect adaptive mechanisms to changed environmental conditions that yeast cells encounter during their existence in nature.


Assuntos
Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/isolamento & purificação , Vitis/microbiologia , Vinho/microbiologia , Agricultura , DNA Fúngico/genética , DNA Mitocondrial/genética , Fermentação , Marcadores Genéticos , Cariotipagem , Repetições de Microssatélites , Polimorfismo Genético , Saccharomyces cerevisiae/fisiologia , Fatores de Tempo
18.
Curr Genet ; 51(3): 161-9, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17186243

RESUMO

The present work describes a detailed physiological and molecular characterization of the mechanisms of transport of carboxylic acids in Kluyveromyces lactis. This yeast species presents two homologue genes to JEN1 of Saccharomyces cerevisiae: KlJEN1 encodes a monocarboxylate permease and KlJEN2 encodes a dicarboxylic acid permease. In the strain K. lactis GG1888, expression of these genes does not require an inducer and activity for both transport systems was observed in glucose-grown cells. To confirm their key role for carboxylic acids transport in K. lactis, null mutants were analyzed. Heterologous expression in S. cerevisiae has been performed and chimeric fusions with GFP showed their proper localization in the plasma membrane. S. cerevisiae jen1delta cells transformed with KlJEN1 recovered the capacity to use lactic acid, as well as to transport labeled lactic acid by a mediated mechanism. When KlJEN2 was heterologously expressed, S. cerevisiae transformants gained the ability to transport labeled succinic and malic acids by a mediated mechanism, exhibiting, however, a poor growth in malic acid containing media. The results confirmed the role of KlJen1p and KlJen2p as mono and dicarboxylic acids permeases, respectively, not subjected to glucose repression, being fully functional in S. cerevisiae.


Assuntos
Ácidos Carboxílicos/metabolismo , Transportadores de Ácidos Dicarboxílicos/genética , Regulação Fúngica da Expressão Gênica , Kluyveromyces/enzimologia , Kluyveromyces/genética , Proteínas de Membrana Transportadoras/genética , Transportadores de Ácidos Monocarboxílicos/genética , Simportadores/genética , Transportadores de Ácidos Dicarboxílicos/biossíntese , Transportadores de Ácidos Dicarboxílicos/fisiologia , Kluyveromyces/metabolismo , Ácido Láctico/metabolismo , Proteínas de Membrana Transportadoras/biossíntese , Proteínas de Membrana Transportadoras/fisiologia , Transportadores de Ácidos Monocarboxílicos/biossíntese , Transportadores de Ácidos Monocarboxílicos/fisiologia , Ácido Pirúvico/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Homologia de Sequência do Ácido Nucleico , Simportadores/biossíntese , Simportadores/fisiologia
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