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Development and validation of a new glaucoma screening test using temporally modulated flicker
Purpose
Describing the psychometric characteristics and diagnostic accuracy of the Accelerator 4‐Alternative Forced‐Choice Flicker Test prototype (A4FTp) for detecting chronic open angle glaucoma (COAG).
Methods
A4FTp measures temporally‐modulated flicker thresholds in regions of the visual field with high susceptibility to glaucomatous loss. We initially evaluated its psychometric properties on 20 normals (aged 33.8 ± 8.5 years) who were tested multiple times over a period of 3 months. All subjects underwent four repetitions for shorter (T8) and longer (T12) staircase termination criteria, to determine the most suitable threshold criterion. Four randomly selected subjects underwent a total of 10 repetitions to study test‐retest repeatability and learning effects. To determine its diagnostic accuracy, one eye of 40 participants with COAG and 38 normal controls were tested with the A4FTp in comparison with the Frequency Doubling Technology (FDT; C20‐5 programme) and iVue Spectral Domain Optical Coherence Tomography (SD‐OCT). Tests were conducted in a random order with results masked to the clinician conducting the reference ophthalmic examination. The accuracy of each test was determined by analysis of the area under the receiver operator characteristic curve (AUROC).
Results
A4FTp flicker thresholds were stable, with standard deviations of only 0.52 decilog (dL) for T8, increasing to 1.32 dL for T12, and no significant flicker sensitivity threshold improvement over the 10 repeat runs. T8 was superior to T12 on several other measures, so it was used for the remaining comparisons. In terms of diagnostic accuracy, the mean AUROC for the three tests were A4FTp [T8 criterion; 0.82, 95% confidence interval (0.73–0.92)]; SD‐OCT [any RNFL parameter p < 1% level; 0.90 (0.83–0.97)]; and FDT [one or more locations missed at p < 5% level; 0.91 (0.82–0.96)]. There was no statistical difference in AUROC between A4FTp and SD‐OCT (p = 0.18) or FDT (p = 0.12). The A4FTp test duration averaged just over 2 min per eye, taking approximately one‐third of the time for completion of the HFA SITA 24‐2 algorithm (conducted as part of the reference examination) and twice the time for the suprathreshold FDT.
Conclusion
Test accuracy for the A4FTp was comparable to those of the FDT and SD‐OCT for the detection of COAG. Time taken to complete the A4FTp was relatively short and initial results are promising. With further refinement, the A4FTp could have a future role in glaucoma detection
Analyzing peptides and proteins by mass spectrometry: principles and applications in proteomics
Podeu consultar el llibre complet a: http://hdl.handle.net/2445/32166The study of proteins has been a key element in biomedicine and biotechnology because of their important role in cell functions or enzymatic activity. Cells are the basic unit of living organisms, which are governed by a vast range of chemical reactions. These chemical reactions must be highly regulated
in order to achieve homeostasis. Proteins are polymeric molecules that have
taken on the evolutionary process the role, along with other factors, of control
these chemical reactions. Learning how proteins interact and control their up and
down regulations can teach us how living cells regulate their functions, as well as
the cause of certain anomalies that occur in different diseases where proteins are
involved. Mass spectrometry (MS) is an analytical widely used technique to study
the protein content inside the cells as a biomarker point, which describes
dysfunctions in diseases and increases knowledge of how proteins are working.
All the methodologies involved in these descriptions are integrated in the field
called Proteomics
Role of advanced technology in the detection of sight-threatening eye disease in a UK community setting.
Background/aims: To determine the performance of combinations of structural and functional screening tests in detecting sight-threatening eye disease in a cohort of elderly subjects recruited from primary care. Methods: 505 subjects aged ≥60 years underwent frequency doubling technology (FDT) perimetry, iVue optical coherence tomography (iWellness and peripapillary retinal nerve fibre layer (RNFL) scans) and intraocular pressure with the Ocular Response Analyzer, all performed by an ophthalmic technician. The reference standard was a full ophthalmic examination by an experienced clinician who was masked to the index test results. Subjects were classified as presence or absence of sight-threatening eye disease (clinically significant cataract, primary open-angle glaucoma, intermediate or advanced age-related macular degeneration and significant diabetic retinopathy). Univariate and multivariate logistic regression analyses were used to determine the association between abnormal screening test results and the presence of sight-threatening eye disease. Results: 171 subjects (33.8%) had one or more sight-threatening eye diseases. The multivariate analysis found significant associations with any of the target conditions for visual acuity of <6/12, an abnormal FDT and peripapillary RNFL thickness outside the 99% normal limit. The sensitivity of this optimised screening panel was 61.3% (95% CI 53.5 to 68.7), with a specificity of 78.8% (95% CI 74.0 to 83.1), a positive predictive value of 59.5% (95% CI 53.7 to 65.2) and an overall diagnostic accuracy of 72.9% (95% CI 68.8 to 76.8). Conclusions: A subset of screening tests may provide an accurate and efficient means of population screening for significant eye disease in the elderly. This study provides useful preliminary data to inform the development of further larger, multicentre screening studies to validate this screening panel
Sirolimus no Tratamento de um Linfangioma Quístico num Doente Pediátrico
Cystic lymphangioma (CL) is a rare benign tumor, which occurs typically during childhood, with craniofacial, cervical or axillary being the most common locations. Lymphangiomas management can be challenging due to their permeative growth throughout tissue layers. Sirolimus is an immunosuppressive and antitumor agent that can inhibit abnormal vascular proliferation by blocking the mTOR/PI3K pathway. It is typically well-tolerated, with nausea, cytopenias, and metabolic imbalances as the most significant adverse effects. We present the case of a pediatric patient in which sirolimus was used to treat a macrocytic lymphangioma, highlighting its effectiveness and safety.info:eu-repo/semantics/publishedVersio
Growth and biochemical profile of juvenile mussels (mytilus galloprovincialis Lmk) fed on different algal diets
The food value of different microalgal diets to juvenile Mytilus galloprovincialis Lmk was assessed. Three different marine microalgae species (Tetraselmis suecica, Dunaliella tertiolecta and Phaeodactylum tricornutum) were fed singly and in various mixtures. Composition of the mixtures was based on the dry weight of(n~cells. Significantly higher growth rates in length and volume were obtained with diets containing T. suecica. Differences in food value between diets containing T. suecica and the remainder also were observed in terms of growth in dry and organic weights, gross growth efficiencies and condition indexes. All these parameters were correlated significantly with each other. The biochemical profile of the mussels also was modified by the diet. Mussels fed on diets containing D. tertiolecta showed increased levels of carbohydrales. Growth rates, gross growth efficiencies and condition indexes were correlated significantly with the protein and lipid deposited as body constituents, and lipid content (%DW) of the mussels. In the diets of higher growth, 44-47% of algal protein supplied was deposited as body protein, against 4.2-4.5% of Jipids and 33-64% of carbohydrates.Consejo Interinstitucional de Ciencia y Tecnología; nº AGF92-073
Diagnóstico do espaço turístico e das propostas de gestão no município de Cachoeiras de Macacu.
bitstream/CNPS-2010/14742/1/bpd135-2009-planejamento-espaco-turistico.pd
High pressure and thermal pasteurization effects on sweet cherry juice microbiological stability and physicochemical properties
This study evaluated high pressure processing (P1 – 400 MPa/5 min; P2 – 550 MPa/2 min) and thermal
pasteurization (TP – 70°C/30 s) effects on sweet cherry juice’s microbiological and physicochemical
parameters, during four weeks of refrigerated storage. All treatments reduced the microbiological load
to undetectable levels not affecting total soluble solids and titratable acidity. The pH increased with all
treatments, however, it decreased during storage. Phenols were differently affected: TP increased them
by 6%, P1 had no effect while P2 decreased them by 11%. During storage, phenols in control and TP
samples decreased by 26% and 20%, P1 samples decreased them by 11% whereas P2 showed no variation.
TP had no effect on anthocyanins, while pressure treatments increased them by 8%. Anthocyanins
decreased during storage, particularly in the control and P1 (decreasing 41%). All treatments had no effect
on antioxidant activity until the 14th day, thereafter high pressure processing samples showed the highest
antioxidant activity
Shelf-life extension of watermelon juice preserved by hyperbaric storage at room temperature compared to refrigeration
This work reports Hyperbaric Storage (HS) preservation of raw watermelon juice at variable/uncontrolled
room temperature (RT,z21 C) for 7 days at 100 MPa and compared it with refrigeration (RF). At the end
of storage, there was an increase in microbial counts (total aerobic mesophiles, psychrophiles, and yeasts
and moulds) to above 6 log10 CFU/mL for samples stored at atmospheric pressure (RF and RT), while juice
stored under HS/RT showed maximum values of about 2 log10 CFU/mL for total aerobic mesophiles/
psychrophiles and below the detection limit for yeasts and moulds. HS/RT juice showed also physicochemical
parameters at levels similar to the initial juice. Thus, HS/RT can not only be used to preserve foods with no refrigeration energetic costs (since it does not require temperature control), but additionally, has also a great potential to extend the shelf-life of food products, compared to RF. This is the first case in the literature showing this additional potential/advantage of HS/RT
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