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Golden Standard (golden + standard)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Which color vision test should be used in progressive cone dystrophy?

ACTA OPHTHALMOLOGICA, Issue 2007
AAHJ THIADENS
Purpose: The early manifestation of progressive cone dystrophy (COD) can remain unrecognized due to the relatively normal macular appearance. Color vision testing can be very useful as a first diagnostic step. The many available color vision tests have different benefits and shortcomings. We aimed to identify which test would be preferred to use in a clinical setting as a first step towards diagnosis of COD. Methods: We compared patients (n=18) derived from the ophthalmogenetic unit of Erasmus Medical Center and University Medical Center Nijmegen, with various levels of cone dysfunction. Golden Standard for diagnosis of COD was a diminished photopic ERG and a relative central scotoma on Goldmann perimetry. Controls (n=33) were patients from these clinics with other diagnoses or healthy companions of COD patients. We estimated sensitivity and specificity of the Ishihara test, Lanthony Desaturated and Saturated Panel D15 test, the Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates, and the Nagel anomaloscope. We analyzed sensitivity, specificity and the predictive value with receiver operating characteristic curve (ROC). Results: The HRR test had the highest sensitivity and specificity for protan and deutan axes. HRR and Ishihara had the highest predictive value. Lanthony Panel D15 test did not have an additional predictive value for severe color vision defects. The Nagel anomaloscope was not reliable due to low specificity. Its results showed high variations among both healthy and afflicted individuals. Conclusions: The HRR test was the most useful for COD. This test had the highest sensitivity in detecting early dysfunction of all three cone types, and it adequately quantifies the level of cone dysfunction in the course of the disease. [source]

Medical imaging and MRI in nail disorders: report of 119 cases and review of the literature

DERMATOLOGIC THERAPY, Issue 2 2002
Bertrand Richert
Radiographs remain the golden standard for exploration of the bony structures located beneath the nail plate, but they provide no information on the perionychium. Until a few years ago the nail apparatus was deprived of investigative medical imaging. Glomus tumor was the only condition that was explored using invasive techniques such as angiography or scintigraphy. High-frequency ultrasound rapidly came up against technical limits. High-resolution magnetic resonance imaging (MRI) offers a superior alternative in detection of distal lesions as well as their relationship with the adjacent structures. MRI provides an accurate analysis of the nail apparatus with detection of lesions as small as 1 mm. This noninvasive technique will allow us to better understand, diagnose, and treat pathologies of the distal phalanx. [source]

The clinical value of rapid assay for plasma B-type natriuretic peptide in differentiating congestive heart failure from pulmonary causes of dyspnoea

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2008
S.-Q. Zhao
Summary Background:, B-type natriuretic peptide (BNP) is a cardiac neurohormone secreted from the cardiac ventricles in response to pressure overload. Objective:, To evaluate the optimal cutoff point of plasma BNP in diagnosing congestive heart failure (CHF). Methods:, We conducted a prospective study of 195 patients who were hospitalised with dyspnoea. Pulmonary capillary wedge pressure (PCWP) was measured with a Swan-Ganz catheterisation and plasma BNP level was obtained by a rapid immunofluorescence assay in all patients. PCWP > 12 mmHg was chosen as the golden standard for left ventricular dysfunction in this study. The subjects were divided into two groups by the criteria, one group with dyspnoea caused by CHF (n = 134) and the other caused by lung diseases (n = 61). Results:, (1) BNP cutoff point of 100 pg/ml had a sensitivity of 94.34%, a specificity of 92.13% and an accuracy of 93.33% for differentiating CHF from pulmonary dyspnoea. (2) By multiple logistic-regression analysis, measurements of BNP added significantly independent predictive power to other clinical variables in models predicting which patients had CHF. Conclusion:, A value of 100 pg/ml or more for a rapid BNP assay may be the most accurate independent predictor of the presence or absence of CHF. [source]

The use of porous calcium phosphate scaffolds with transforming growth factor beta 1 as an onlay bone graft substitute

CLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2004
An experimental study in rats
Abstract Objectives: Autogeneous bone grafting is regarded to be the golden standard for onlay grafts, but it requires a harvesting procedure and the remodeling pattern over time is unpredictable. New materials are constantly being sought to overcome these problems. An in vivo experiment was carried out to evaluate whether (1) porous calcium phosphate cement is a suitable biomaterial for onlay bone grafting, and (2) the addition of transforming growth factor beta 1 (TGF-,1) accelerates de novo bone formation inside the cement porosity. Material and methods: A carrier of porous calcium phosphate cement (Calcibon®) was designed and 16 rats received one preshaped implant each. In 8 out of 16 implants 0.75 ,g TGF-,1 was applied. The animals were killed after 4 weeks and the characteristics of tissue ingrowth into the onlay graft were evaluated. Results: Histologic and quantitative histomorphometrical measurements demonstrated osteoid-like tissue formation in both experimental groups. The addition of TGF-,1 did not induce significantly more osteoid-like tissue formation. On the other hand, in TGF-,-loaded implants, a higher number of pores contained an inflammatory infiltrate. Conclusion: This study indicated that porous calcium phosphate cement is a promising material for clinical situations where bone formation has to be supported. Résumé La greffe osseuse autogčne est considérée comme la meilleure technique actuelle pour les greffons onlay mais elle requiert un processus de prélevement et le remodelage qui s'en suit est imprévisible. De nouveaux matériaux sont donc constamment recherchés. Cette étude in vitro a essayé d'évaluer si 1) le cément phosphate calcium poreux était un biomatériel favorable pour le greffage osseux onlay, 2) si l'addition de TGF-,1 accélérait la néoformation osseuse ŕ l'intérieur de la porosité du cément. Un porteur de cément phosphate calcium poreux (Calcibon®) a été fabriqué et seize rats ont reçu chacun un implant prédécoupé. Au niveau de huit des seize implants 0,75 ,g de TGF ,1 a été appliqué. Les animaux ont été euthanasiés aprčs quatre semaines et les caractéristiques de la croissance interne tissulaire dans le greffon onlay ont étéévaluées. Les mesures histologiques et histomorphométriques quantitatives ont démontré une formation tissulaire semblable ŕ l'ostéogénie dans les deux groupes expérimentaux. L'addition de TGF-ß1 n'induisait pas plus de formation tissulaire ressemblant ŕ celle d'ostéogénie. D'un autre côté, dans les implants chargés de TGF-,1, un nombre plus important de pores contenaient un infiltrat inflammatoire. Cette étude indique que le cément phosphate calcium poreux est un matériau prometteur pour les situations cliniques dans lesquelles la formation osseuse doit ętre améliorée. Zusammenfassung Ziel: Die Transplantation von autologem Knochen wird heute als Goldstandard für die Onlay-Transplantate betrachtet. Es braucht dazu aber einen zusätzlichen Eingriff für die Entnahme und eine Prognose bezüglich der anschliessenden Remodellationsvorgänge sind kaum möglich. Man sucht ständig nach neuen Produkten, um diese Probleme zu überwinden. Man führte eine in vivo Studie durch und untersucht, ob (1) ein poröser Kalziumphosphatzement ein brauchbares Biomaterial für ein Onlay-Transplantat ist, und (2) der Zusatz von TGF-,1 die Neubildung von Knochen in den Porositäten des Zementes positiv beeinflusst. Material und Methode: Man entwickelte einen Trägerzement aus porösem Kalziumphosphat (Calcibon®) und 16 Ratten erhielten je ein vorgeformtes Implantat eingesetzt. Bei 8 der 16 Implantate fügte man zusätzlich 0.75 ,g TGF-,1 dazu. Vier Wochen später opferte man die Tiere und konnte nun die Charakteristika des in die Implantate einwachsenden Gewebes untersuchen. Resultate: Die histologischen und quantitativen histomorphometrischen Messungen zeigten in beiden experimentellen Gruppen osteoidähnliche Gewebsbildungen. Der Zusatz von TGF-,1 bewirkte keine signifikante Zunahme dieser osteoidähnlichen Gewebsbildungen. Die mit TGF-,1 durchsetzten Implantate enthielten aber mehr mit entzündlichem Infiltrat angefüllte Poren. Zusammenfassung: Diese Arbeit zeigte uns, dass ein poröser Kalziumphosphatzement bei klinischen Situationen, wo die Knochenbildung unterstützt werden muss, ein erfolgsversprechendes Material ist. Resumen Objetivos: El injerto de hueso autógeno está considerado como el estándar de oro para injertos superpuestos, pero requiere un procedimiento de recolección y el patrón de remodelado a lo largo del tiempo es impredecible. Constantemente se están buscando materiales nuevos para superar estos problemas. Se llevó a cabo un experimento in vivo para evaluar si (1) el cemento de fosfato cálcico poroso es un biomaterial apropiado para injerto óseo superpuesto, y (2) la adición de TGF-,1 acelera la formación de hueso de novo dentro de la porosidad del cemento. Material y Métodos: Se diseńó un portador de cemento de fosfato cálcico (Calcibon®) y 16 ratas recibieron un implante preformado cada una. En 8 de 16 implantes se aplicaron 0.75 ,g de TGF-,1. Los animales se sacrificaron tras 4 semanas y se evaluaron las características del tejido crecido hacia adentro del injerto superpuesto. Resultados: Las mediciones histológicas e histomorfométricas cuantitativas demostraron formación de tejido tipo osteoide en ambos grupos experimentales. La adición de TGF-,1 no indujo significativamente más formación de tejido tipo osteoide. Por otro lado, en los implantes cargados con TGF-,1, un mayor número de de poros contenían infiltrado inflamatorio. Conclusión: Este estudio indica que el cemento de fosfato cálcico poroso es un material prometedor para situaciones clínicas donde la formación de hueso ha de ser favorecida. [source]

Bimodal skin reactivity to histamine in atopic children in Singapore: influence of specific sensitizations

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 6 2004
Mona Iancovici Kidon
Histamine skin prick test (SPT) is used as the ,golden standard' for positive control in in vivo immediate type hypersensitivity testing. The skin reactivity to histamine can, however, be modulated by a bevy of extraneous factors. We aimed to define whether histamine skin reactivity in atopic children in Singapore is influenced by age, ethnic origin, gender, environmental exposure or specific sensitization patterns. A retrospective analysis of children, with specific aeroallergen sensitization (as measured by at least one allergen-specific SPT with a wheal size >3 mm compared with the negative control) from the outpatient speciality clinic of the KK Children's Hospital, during 06/2002,06/2003. A total of 315 patients were included, 235 (75%) were males, 252 (80%) were Chinese, age mean was 7.7 yr (range: 2,15). Patients were referred to the SPT with a diagnosis of one or more of: allergic rhinitis 287 (91%), asthma 112 (36%) or atopic dermatitis 60 (19%). The mean histamine response showed a bimodal distribution, independent of age, ethnic origin, gender or phenotypical expression of allergic disease. Histamine skin reactivity was higher in atopic patients with polysensitization (mean 5.0 mm vs. 2.9 mm in monosensitized patients, p < 0.001), and in patients with mould sensitization (mean 5.1 mm vs. 3.3 mm in patient not sensitized to moulds, p < 0.001). The presence of passive smoking increased the likelihood of a diminished histamine skin response. Histamine skin response data strongly suggested the presence of two heterogeneous subpopulations. Children with polysensitization and mould sensitization were more likely to show a large significant histamine response, whereas children with passive smoke exposure, showed a diminished skin reactivity to histamine. [source]