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Sensitivity
Kinds of Sensitivity Terms modified by Sensitivity Selected AbstractsPERCEPTION OF MOUTHFEEL SENSATIONS ELICITED BY RED WINE ARE ASSOCIATED WITH SENSITIVITY TO 6-N-PROPYLTHIOURACILJOURNAL OF SENSORY STUDIES, Issue 3 2006GARY J. PICKERING ABSTRACT This study investigated the relationship between sensitivity to the bitterness of 6-n-propylthiouracil (PROP) , a genetically determined trait used as an index of general taste acuity , and a range of oral sensations elicited by 16 varietal red wines. Seventeen subjects were trained using descriptive analysis (DA) techniques and developed a lexicon consisting of three taste and 10 tactile attributes representing sensations experienced both in-mouth (IM) and after expectoration (AE). Analysis of variance showed that PROP super-tasters (ST) (n = 8) rated 11 of these 13 sensations differently compared to PROP nontasters (NT) (n = 8), specifically acidity, saltiness, heat/irritation, tingle/prickle, particulate IM, particulate AE, smoothness IM, smoothness AE, grippy/adhesive, mouthcoat and overall astringency. The greater sensitivity of ST to the textural components of red wine is discussed in the context of greater lingual acuity and implications for DA panels, psychophysics and wine consumer behavior. [source] SIMULATED MICROGRAVITY [BED REST] HAS LITTLE INFLUENCE ON TASTE, ODOR OR TRIGEMINAL SENSITIVITYJOURNAL OF SENSORY STUDIES, Issue 1 2001ZATA M. VICKERS ABSTRACT Anecdotal evidence suggests that astronauts' perceptions of foods in space flight may differ from their perceptions of the same foods on Earth. Fluid shifts toward the head experienced in space may alter the astronauts' sensitivity to odors and tastes, producing altered perceptions. Our objective was to determine whether head-down bed rest, which produces similar fluid shifts, would produce changes in sensitivity to taste, odor or trigeminal sensations. Six subjects were tested three times prior to bed rest, three times during bed rest and two times after bed rest to determine their threshold sensitivity to the odors isoamylbutyrate and menthone, the tastants sucrose, sodium chloride, citric acid, quinine and monosodium glutamate, and to capsaicin. Thresholds were measured using a modified staircase procedure. Self-reported congestion was also recorded at each test time. Thresholds for monosodium glutamate where slightly higher during bed rest. None of the other thresholds were altered by bed rest. [source] ELECTRONEUROGRAPHY IN GUILLAIN-BARRE, SYNDROME (GBS): SENSITIVITY AND SPECIFICITYJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2000G. Iuliano We assessed clinical sensitivity and specificity of different electroneurographic (ENG) parameters versus clinical diagnosis of GBS. Clinical data of 24 patients affected by upper and lower limb neuropathy were revised. In all the patients the neurophysiologic examination was performed according to the AAEM guidelines for GBS diagnosis. Fourteen patients (10 males, mean age 47.9, range 13-70, and 4 females 71.5, 69,76) received a diagnosis of GBS. The non-GBS group included nine males (59.11, 35,78) and one female (41 years) with different neuropathies (3 diabetic, 2 alcoholic, 5 unknown ethiology). Sensitivity and specificity of various neurophysiologic parameters were calculated. The single classical neurophysiological paremeters gave variable values of sensitivity and specificity. The new variables we introduced, Polineuropathy (diffusion of abnormal findings and F - Wave latency) and Demyelination (distal motor evoked potential amplitude and/or motor conduction blocks) gave the highest value of sensitivity and specificity, when associated. [source] SENSITIVITY OF INVESTOR REACTION TO MARKET DIRECTION AND VOLATILITY: DIVIDEND CHANGE ANNOUNCEMENTSTHE JOURNAL OF FINANCIAL RESEARCH, Issue 1 2005Diane Scott Docking Abstract We examine whether investor reactions are sensitive to the recent direction or volatility of underlying market movements. We find that dividend change announcements elicit a greater change in stock price when the nature of the news (good or bad) goes against the grain of the recent market direction during volatile times. For example, announcements to lower dividends elicit a significantly greater decrease in stock price when market returns have been up and more volatile. Similarly, announcements to raise dividends tends to elicit a greater increase in stock price when market returns have been normal or down and more volatile, although this latter tendency lacks statistical significance. We suggest an explanation for these results that combines the implications of a dynamic rational expectations equilibrium model with behavioral considerations that link the responsiveness of investors to market direction and volatility. [source] Diagnostic and Prognostic Use of Stress Echocardiography in Stable PatientsECHOCARDIOGRAPHY, Issue 5 2000Steven C. Smart M.D. Stress echocardiography is an effective diagnostic and prognostic technique in stable patients with known or suspected coronary artery disease (CAD), myocardial infarction, or chronic left ventricular dysfunction and those undergoing noncardiac surgery. Stress echocardiography is sensitive and specific for the detection and extent of CAD. Negative tests confer a high negative predictive value for cardiac events regardless of the clinical risk. Positive studies confer a high positive predictive value for ischemic events in patients with intermediate to high clinical risk. Stress echocardiography provides incremental prognostic information relative to clinical, resting echocardiographic, and angiographic data. Meta-analysis studies have shown that the diagnostic and prognostic information provided by stress echocardiography is comparable to that from radionuclide scintigraphic stress tests. Stress echocardiography may be more specific for the detection and extent of CAD, whereas radionuclide scintigraphy may be more sensitive for one-vessel disease. Sensitivities are similar for the detection and extent of disease in patients with multivessel CAD. [source] Trying to See Red Through Stickleback Photoreceptors: Functional Substitution of Receptor SensitivitiesETHOLOGY, Issue 3 2006Mickey P. Rowe A key to understanding animal behavior is knowledge of the sensory information animals extract from their environment. For visually motivated tasks, the information animals obtain through their eyes is often assumed to be essentially the same as that perceived by humans. However, known differences in structure and processing among the visual systems of different animals clearly indicate that the world seen by each is different. A well-characterized difference between human and other animal visual systems is the number of types and spectral sensitivities of their photoreceptors. We are developing a technique, functional substitution, that exploits knowledge of these differences to portray for human subjects, colors as they would appear through the photoreceptors of another animal. In a specific application, we ask human subjects to rank hues of male threespine stickleback (Gasterosteus aculeatus) throats viewed through stickleback photopigments. We compare these ranks to ranks of the same throat hues viewed through normal human photoreceptors. We find essentially no difference between the two sets of rankings. This suggests that any differences in human and stickleback rankings of such hues would result from differences in post-receptoral neural processing. Using a previously developed model of stickleback neural processing, we established another ranking of the hues which was again essentially the same as the rankings produced by the human subjects. A growing literature indicates that stickleback do rank such hues in the evaluation of males as potential mates or threats. Although our results do not demonstrate that humans and stickleback use the same mechanisms to assess color, our experiments significantly failed to show that stickleback and human rankings of throat hues should be different. Nevertheless, a comparison of all these rankings to ranks derived from subjective color scoring by human observers suggests that color scoring may utilize other cues and should thus be used cautiously. [source] Opening the Social Gateway: Early Vocal and Social Sensitivities in Brown-Headed Cowbirds (Molothrus ater)ETHOLOGY, Issue 1 2002David J. White The organization of cowbird (Molothrus ater) social groups affords individuals living in the groups different opportunities for learning and also structures trajectories of social development. Here, we studied the influence of adults on social organization of very young cowbirds. In three experiments, we housed juvenile birds in large, seminatural environments that either contained or did not contain adult conspecifics. We then observed the social associations and vocalizations of juveniles in each environment. The presence of adults in the social environment influenced the assortment and singing patterns of juveniles, although throughout the three experiments adults rarely interacted physically with juveniles. Juveniles housed with adults interacted with other juveniles more often and sang significantly less often than juveniles housed without adults. Effects of adult presence or absence on social organization and singing patterns emerged extremely rapidly and could be reversed quickly. Taken as a whole, the experiments revealed that very young cowbirds, in the first days of independence from their hosts, were sensitive to, and reacted rapidly to, the composition of their social environment. Specifically, presence of other age classes of individuals within the group increased juvenile associations and delayed production of vocalizations by juvenile males. Self-organization within the social group produced different social environments, which could in turn create different gateways for social learning and vocal development. [source] CLINICAL STUDY/BIOMARKER: Phosphatidylethanol: normalization during detoxification, gender aspects and correlation with other biomarkers and self-reportsADDICTION BIOLOGY, Issue 1 2010Friedrich Martin Wurst ABSTRACT Phosphatidylethanol (PEth) is a direct ethanol metabolite, and has recently attracted attention as biomarker of ethanol intake. The aims of the current study are: (1) to characterize the normalization time of PEth in larger samples than previously conducted; (2) to elucidate potential gender differences; and (3) to report the correlation of PEth with other biomarkers and self-reported alcohol consumption. Fifty-seven alcohol-dependent patients (ICD 10 F 10.25; 9 females, 48 males) entering medical detoxification at three study sites were enrolled. The study sample was comprised of 48 males and 9 females, with mean age 43.5. Mean gamma glutamyl transpeptidase (GGT) was 209.61 U/l, average mean corpuscular volume (MCV) was 97.35 fl, mean carbohydrate deficient transferrin (%CDT) was 8.68, and mean total ethanol intake in the last 7 days was 1653 g. PEth was measured in heparinized whole blood with a high-pressure liquid chromatography method, while GGT, MCV and %CDT were measured using routine methods. PEth levels at day 1 of detoxification ranged between 0.63 and 26.95 µmol/l (6.22 mean, 4.70 median, SD 4.97). There were no false negatives at day 1. Sensitivities for the other biomarkers were 40.4% for MCV, 73.1% for GGT and 69.2% for %CDT, respectively. No gender differences were found for PEth levels at any time point. Our data suggest that PEth is (1) a suitable intermediate term marker of ethanol intake in both sexes; and (2) sensitivity is extraordinary high in alcohol dependent patients. The results add further evidence to the data that suggest that PEth has potential as a candidate for a sensitive and specific biomarker, which reflects longer-lasting intake of higher amounts of alcohol and seemingly has the above mentioned certain advantages over traditional biomarkers. [source] Accuracy of computer-automated caries detection in digital radiographs compared with human observersEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2002Ann Wenzel The aim of this study was to compare diagnostic accuracy of a caries detection program with that of human observers. A total of 190 extracted teeth were radiographed with two Trophy RVG (RadioVisioGraphy) digital sensor systems. Four observers scored the approximal surfaces in all images on a disease severity scale. Each observer thereafter used the Logicon Caries Detector (LCD) program to analyse the surfaces in the digital images and recorded their outcome. To determine the true absence or presence of caries, histological validation was used. Sensitivities, specificities, positive and negative predictive values were calculated and differences between the diagnostic methods tested. Specificities for the outcome with the LCD were significantly lower for three observers than when they themselves assessed the RVG images and, correspondingly, the positive predictive values were lower for the LCD outcome for three of the observers. Sensitivity was also lower for two observers on the diagnostic threshold caries in dentine. It was concluded that the automated caries detection program is less accurate than human observers in detecting approximal caries lesions. [source] Can Contaminant Transport Models Predict Breakthrough?GROUND WATER MONITORING & REMEDIATION, Issue 4 2000Wei-Shyuan "Stone" Peng A solute breakthrough curve measured during a two-well tracer test was successfully predicted in 1986 using specialized contaminant transport models. Water was injected into a confined, unconsolidated sand aquifer and pumped out 125 feet (38.3 m) away at the same steady rate. The injected water was spiked with bromide for over three days; the outflow concentration was monitored for a month. Based on previous tests, the horizontal hydraulic conductivity of the thick aquifer varied by a factor of seven among 12 layers. Assuming stratified flow with small dispersivities, two research groups accurately predicted breakthrough with three-dimensional (12-layer) models using curvilinear elements following the arc-shaped flowlines in this test. Can contaminant transport models commonly used in industry, that use rectangular blocks, also reproduce this breakthrough curve? The two-well test was simulated with four MODFLOW-based models, MT3D (FD and HMOC options), MODFLOWT, MOC3D, and MODFLOW-SURFACT. Using the same 12 layers and small dispersivity used in the successful 1986 simulations, these models fit almost as accurately as the models using curvilinear blocks. Subtle variations in the curves illustrate differences among the codes. Sensitivities of the results to number and size of grid blocks, number of layers, boundary conditions, and values of dispersivity and porosity are briefly presented. The fit between calculated and measured breakthrough curves degenerated as the number of layers and/or grid blocks decreased, reflecting a loss of model predictive power as the level of characterization lessened. Therefore, the breakthrough curve for most field sites can be predicted only qualitatively due to limited characterization of the hydrogeology and contaminant source strength. [source] Validation of a simple model for predicting liver fibrosis in HIV/hepatitis C virus-coinfected patientsHIV MEDICINE, Issue 6 2005H Al-Mohri Objectives Recently, several models incorporating laboratory measurements have been validated for use as surrogate markers for liver fibrosis in hepatitis C virus (HCV) mono-infection, the simplest of these being the aspartate aminotransferase (AST) to platelet ratio index (APRI). We evaluated how well the APRI predicts significant hepatic fibrosis in patients with HIV/HCV coinfection. Methods Forty-six HIV/HCV-coinfected patients who underwent liver biopsy and had concomitant laboratory measurements (±3 months) were included in the study. Significant fibrosis was defined as F2,F4 using Batt and Ludwig scoring (=3 Ishak). APRI=[(AST/upper limit of normal)/platelet count (109/L)] × 100. We used sas proc logistic (SAS Institute, Cary, NC) to calculate the area under the receiver operating curve (ROC) (AUC). Sensitivities, specificities, positive predictive value (PPV) and negative predictive value (NPV) were compared using cut-offs previously identified in the literature. Results Thirty-three of 46 patients (72%) had significant fibrosis on biopsy. For significant fibrosis, the area under the ROC for the APRI was 0.847±0.057. APRI scores >1.5 (the higher cut-off) were 100% specific and 52% sensitive; PPV was 100% and NPV 45%. Scores <0.5 (the lower cut-off) were 82% sensitive and 46% specific in ruling out significant fibrosis (PPV 79%; NPV 50%). Conclusions A simple model incorporating readily available laboratory data is highly predictive of significant fibrosis in HIV/HCV coinfection and could serve as a biopsy-sparing measure, thus making treatment more accessible for this population. [source] The usefulness of sensitivity analysis for predicting the effects of cat predation on the population dynamics of their avian preyIBIS, Issue 2008MAIREAD M. MACLEAN Sensitivity analyses of population projection matrix (PPM) models are often used to identify life-history perturbations that will most influence a population's future dynamics. Sensitivities are linear extrapolations of the relationship between a population's growth rate and perturbations to its demographic parameters. Their effectiveness depends on the validity of the assumption of linearity. Here we assess whether sensitivity analysis is an appropriate tool to investigate the effect of predation by cats on the population growth rates of their avian prey. We assess whether predation by cats leads to non-linear effects on population growth and compare population growth rates predicted by sensitivity analysis with those predicted by a non-linear simulation. For a two-stage, age-classified House Sparrow Passer domesticus PPM slight non-linearity arose when PPM elements were perturbed, but perturbation to the vital rates underlying the matrix elements had a linear impact on population growth rate. We found a similar effect with a slightly larger three-stage, age-classified PPM for a Winter Wren Troglodytes troglodytes population perturbed by cat predation. For some avian species, predation by cats may cause linear or only slightly nonlinear impacts on population growth rates. For these species, sensitivity analysis appears to be a useful conservation tool. However, further work on multiple perturbations to avian prey species with more complicated life histories and higher-dimension PPM models is required. [source] Parameter sensitivity in finite element analysis with constitutive models of the rate typeINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2006Wolfgang Fellin Abstract Non-linear soil,structure interactions are usually analysed using an incremental finite element approach. There a constitutive subroutine provides for each element the stress increment for a given strain increment. In geotechnical calculations, uncertainties in material parameters and initial conditions are abundant. Sensitivity analysis can be a first step to account for such uncertainties. Sensitivities of the system response with respect to material parameters and initial conditions can be calculated by differentiating the whole numerical scheme. It turns out that the essential information from the constitutive subroutine are the derivatives of the stress increment with respect to the strain increment, as well as the derivatives with respect to material parameters and all state variables involved in the problem. We propose a method to compute these quantities numerically for any constitutive model that can be written in rate form and for any suitable integrator of such a model. We further present a concise way to supply the output of the sensitivity analysis to the designing engineer. Our theoretical investigations are illustrated with element tests and with a typical geotechnical application. Copyright © 2005 John Wiley & Sons, Ltd. [source] Finite element and sensitivity analysis of thermally induced flow instabilitiesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 10 2010Jean-Serge Giguère Abstract This paper presents a finite element algorithm for the simulation of thermo-hydrodynamic instabilities causing manufacturing defects in injection molding of plastic and metal powder. Mold-filling parameters determine the flow pattern during filling, which in turn influences the quality of the final part. Insufficiently, well-controlled operating conditions may generate inhomogeneities, empty spaces or unusable parts. An understanding of the flow behavior will enable manufacturers to reduce or even eliminate defects and improve their competitiveness. This work presents a rigorous study using numerical simulation and sensitivity analysis. The problem is modeled by the Navier,Stokes equations, the energy equation and a generalized Newtonian viscosity model. The solution algorithm is applied to a simple flow in a symmetrical gate geometry. This problem exhibits both symmetrical and non-symmetrical solutions depending on the values taken by flow parameters. Under particular combinations of operating conditions, the flow was stable and symmetric, while some other combinations leading to large thermally induced viscosity gradients produce unstable and asymmetric flow. Based on the numerical results, a stability chart of the flow was established, identifying the boundaries between regions of stable and unstable flow in terms of the Graetz number (ratio of thermal conduction time to the convection time scale) and B, a dimensionless ratio indicating the sensitivity of viscosity to temperature changes. Sensitivities with respect to flow parameters are then computed using the continuous sensitivity equations method. We demonstrate that sensitivities are able to detect the transition between the stable and unstable flow regimes and correctly indicate how parameters should change in order to increase the stability of the flow. Copyright © 2009 John Wiley & Sons, Ltd. [source] Screening for mild cognitive impairment: a systematic reviewINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 9 2009Jane A. Lonie Abstract Objective Patients with mild cognitive impairment account for a significant number of referrals to old age psychiatry services and specialist memory clinics. The cognitive evaluation of such patients is commonly restricted to brief dementia screens, with no consideration to their suitability for assessing MCI. Here, we review the utility of such cognitive screens for MCI and provide an overview of validated instruments. Methods We identified papers published after Petersen and colleagues 1999 MCI criteria (Petersen et al., 1999) and examining face-to-face cognitive screening for MCI from publication databases using combinations of the search terms ,mild cognitive impairment' and ,cognitive screening'. We also combined the former search with the names of 39 screening tests recently identified in a relevant review (Cullen et al., 2007). Results Fifteen cognitive screening instruments were identified, 11 cover a restricted range of cognitive domains. High sensitivity and specificity for MCI relative to healthy controls were reported for two comprehensive and two noncomprehensive screening instruments, adequate test-retest and inter-rater reliability for only one of these. With the exception of three studies, sample sizes were universally small (i.e. n,,,100), and prognostic values were reported for only two of the identified 15 screening measures. Sensitivities of the full domain measures were universally high, but information about their specificity against psychiatric and non-progressive neurological conditions and predictive validity is lacking. Conclusion Several cognitive screening instruments afford the clinician the ability to detect MCI, early AD, and in some cases non-AD dementia, but they cannot currently be used to make reliable inferences about the course and eventual outcome of MCI. Copyright © 2009 John Wiley & Sons, Ltd. [source] The clock drawing test in primary care: sensitivity in dementia detection and specificity against normal and depressed elderlyINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 10 2001Michael Kirby Abstract Objectives The aim of this study was to examine the sensitivities and specificities of the clock drawing test (CDT) in the detection of dementia among older people in primary care, with particular emphasis on the effect of depression on CDT specificity. Most previous studies have been sited in specialist settings and few have addressed the issue of specificity aginst depression. Methods Comparison of cohorts identified from community-based screening with GMS-AGECAT. The CDT and the Mini-Mental State Examination (MMSE) were administered to 41 elderly subjects with organic disorder (dementia), 84 elderly subjects with case level depression and 523 normal elderly subjects. Sensitivities and specificities of the CDT were calculated. Results The sensitivity of the CDT in the detection of dementia in the general community was 76%. The specificities of the CDT against normal elderly and depressed elderly was 81% and 77% respectively. Higher sensitivity and specificity were achieved by the MMSE. Conclusions The use of the CDT in the detection of dementia syndromes is likely to be more relevant in the primary care context than in specialist settings. The CDT provides good sensitivity and specificity but may not be as sensitive or specific in the general community as previous studies have suggested, particularly in mild dementia. Community-based late life depression does not appear to alter the specificity of the CDT. Copyright © 2001 John Wiley & Sons, Ltd. [source] Diagnosis of occlusal caries in primary teethINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 2 2000Ashley Much research has been published over the last few years looking at alternative diagnostic systems for the diagnosis of occlusal caries in permanent teeth, but there has been little research on primary teeth. The aim of this study was to compare the accuracy of one alternative system (the Electronic Caries Monitor [ECM]) against visual diagnosis for the detection of occlusal dentine caries in primary teeth. Fifty-eight apparently noncavitated extracted first and second primary molars were selected. They were examined visually and with the ECM for dentine caries. Presence or absence of caries was validated by hemisecting the teeth and examining them under a stereo-microscope , 37 teeth had occlusal dentine caries, 21 were sound or had enamel caries. Sensitivities and specificities of the ECM diagnoses were 0·81 and 0·90, respectively, and for the visual diagnosis were 0·73 and 1. In conclusion, the ECM did not provide increased accuracy over visual diagnosis when detecting occlusal caries in primary teeth. [source] Estimating the Value of Employee Stock Option Portfolios and Their Sensitivities to Price and VolatilityJOURNAL OF ACCOUNTING RESEARCH, Issue 3 2002John Core The costs associated with compiling data on employee stock option portfolios is a substantial obstacle in investigating the impact of stock options on managerial incentives, accounting choice, financing decisions, and the valuation of equity. We present an accurate method of estimating option portfolio value and the sensitivities of option portfolio value to stock price and stock-return volatility that is easily implemented using data from only the current year's proxy statement or annual report. This method can be applied to either executive stock option portfolios or to firm-wide option plans. In broad samples of actual and simulated CEO option portfolios, we show that these proxies capture more than 99% of the variation in option portfolio value and sensitivities. Sensitivity analysis indicates that the degree of bias in these proxies varies with option portfolio characteristics, and is most severe in samples of CEOs with a large proportion of out-of-the-money options. However, the proxies' explanatory power remains above 95% in all subsamples. [source] Classification of fixed urological cells using Raman tweezersJOURNAL OF BIOPHOTONICS, Issue 1-2 2009Tim J. Harvey Abstract In this paper we report on preliminary investigations into using Raman tweezers to classify urological cell lines. This builds on earlier work within the group, whereby Raman tweezer methodologies were developed, and the application of this technique to differentiate between live prostate cancer (CaP) and bladder cells lines (PC-3 and MGH-U1 respectively) was demonstrated. In this present study we analysed chemically fixed cells using two different fixative methods; SurePathTM (a commercial available liquid based cytology media) and 4% v/v formalin/PBS fixatives. The study has been expanded from our previous live cell study to include the androgen sensitive CaP cell line LNCaP, primary benign prostate hyperplasia (BPH) cells as well as primary urethral cells. Raman light from the cells was collected using a 514.5 nm Ar-ion laser excitation source in back-scattering configuration mode. Principal component-linear discriminate analysis (PC-LDA) models of resulting cell spectra were generated and these were validated using a blind comparison. Sensitivities and specificities of > 72% and 90% respectively, for SurePath fixed cells, and > 93% and 98% respectively for 4% v/v formalin/PBS fixed cells was achieved. The higher prediction results for the formalin fixed cells can be attributed to a better signal-to-noise ratio for spectra obtained from these cells. Following on from this work, urological cell lines were exposed to urine for up to 12 hours to determine the effect of urine on the ability to classify these cells. Results indicate that urine has no detrimental effect on prediction results. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Biopsy site for detecting Helicobacter pylori infection in patients with gastric cancerJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2009Chan Gyoo Kim Abstract Background:,Helicobacter pylori eradication is recommended in post-gastric cancer resection, but premalignant changes may prevent the detection of H. pylori. The aim of this study was to determine appropriate biopsy site for detecting H. pylori in gastric cancer patients. Materials and Methods:, Consecutive patients (194) with gastric adenocarcinoma were prospectively enrolled. Helicobacter pylori was evaluated by serology, histology and rapid urease test. Biopsy sites included antrum lesser curvature, upper body lesser curvature (UBLC) and upper body greater curvature (UBGC). Two biopsy specimens were obtained from each site for histological examination. One additional specimen was obtained from UBGC for the rapid urease test. Results:, The overall infection rate of H. pylori was 84.0% (95% CI 78.9,89.2). The sensitivity of histology for detecting H. pylori at various sites was: antrum (54.9%; 95% CI 45.7,63.9), UBLC (80.3%; 95% CI 72.2,87.0) and UBGC (95.1%; 95% CI 89.6,98.2). Specificities of all three biopsy sites were more than 95%. Sensitivity and specificity of the rapid urease test performed at UBGC were 96% and 100%, respectively. Sensitivities of histology decreased in correlation with increasing severity of atrophy and intestinal metaplasia (both P < 0.001 using the chi-square test for trend). The proportions of moderate to marked atrophy/intestinal metaplasia at UBGC (12.8%/14.7%) were significantly lower than those at antrum (50.0%/57.8%, P < 0.001 respectively) or UBLC (40.0%/48.9%, P < 0.001 respectively). Conclusions:, The UBGC side is the most sensitive and specific biopsy site to detect H. pylori in gastric cancer patients due to less frequent atrophy and intestinal metaplasia than at the antrum or UBLC side. [source] Clinical feature profile of spinocerebellar ataxia type 1,8 predicts genetically defined subtypesMOVEMENT DISORDERS, Issue 11 2005Matthias Maschke MD Abstract An increasing number of genetically defined types of spinocerebellar ataxia (SCA) have been reported in the past decade. Phenotype,genotype correlation studies have suggested a broad overlap between SCA types. The aim of the present study was to identify patterns of clinical features that were likely to distinguish between SCA types and to test the specificity and sensitivity of these signs and symptoms using a Bayesian classifier. In total, 127 patients from 50 families with SCA types 1 to 8 were examined using a worksheet with a panel of 33 symptoms and signs. By computing the probabilities of each trait for each SCA type, we rated the predictive value of each feature for each form of ataxia and then combined the probabilities for the entire panel of traits to construct a Bayesian classifier. Results of this analysis were summarized in a simpler, more operator-based algorithm. Patients with SCA5, SCA6, and SCA8 demonstrated a predominant cerebellar syndrome, whereas patients with SCA1, SCA2, SCA3, SCA4, and SCA7 frequently had clinical features indicating an extracerebellar involvement. The Bayesian classifier predicted the SCA type in 78% of patients with sensitivities between 60 and 100% and specificities between 94 and 98.2%. The highest sensitivity to correctly predict the true SCA type was found for SCA5, SCA7, and SCA8. Sensitivities and specificities found in the present study validate the use of algorithms to help to prioritize specific SCA gene testing, which will help to reduce costs for gene testing. © 2005 Movement Disorder Society [source] Predictive factors for organic central precocious puberty and utility of simplified gonadotropin-releasing hormone testsPEDIATRICS INTERNATIONAL, Issue 6 2007JIN-HO CHOI Abstract Background: The aim of the present study was to determine whether the clinical presentation of patients with central precocious puberty (CPP) permits differentiation between idiopathic and organic forms, and to examine whether luteinizing hormone (LH) determination in single blood sample after gonadotropin-releasing hormone (GnRH) administration is sufficient to diagnose CPP. Methods: Potential clinical and laboratory predictors for the presence of central nervous system (CNS) abnormalities were assessed. Sensitivities and specificities of LH and follicle-stimulating hormone (FSH) levels at 0, 15, 30, 60, 90 and 120 min were compared after GnRH stimulation. Results: In 45 girls with signs of breast development, 26 were diagnosed as having CPP. The age of onset in patients with organic CPP was 4.75 ± 2.01 years (range 1.2,7.1 years, median 5.0 years), whereas the age in patients with idiopathic CPP was 7.09 ± 0.87 years (range 5.0,7.9 years, median 7.0 years). This parameter is the only one showing statistical significance. In addition, the specimen at 30 min after GnRH stimulation yielded highest sensitivity for the diagnosis of CPP. Conclusions: The earlier the onset of disease, the higher the possibility of presence of CNS lesion. According to the mean GnRH-stimulated LH levels and sensitivity at each time, a single blood sample obtained for LH determined after GnRH administration at 30 min can be used to diagnose CPP. [source] The Interdependent and Intertemporal Nature of Financial Decisions: An Application to Cash Flow SensitivitiesTHE JOURNAL OF FINANCE, Issue 2 2010VLADIMIR A. GATCHEV ABSTRACT We develop a dynamic multiequation model where firms make financing and investment decisions jointly subject to the constraint that sources must equal uses of cash. We argue that static models of financial decisions produce inconsistent coefficient estimates, and that models that do not acknowledge the interdependence among decision variables produce inefficient estimates and provide an incomplete and potentially misleading view of financial behavior. We use our model to examine whether firms are constrained from accessing capital markets. Unlike static single-equation studies that find firms underinvest given cash flow shortfalls, we conclude that firms maintain investment by borrowing. [source] Parathyroid Adenoma Localization: Surgeon-Performed Ultrasound Versus Sestamibi,THE LARYNGOSCOPE, Issue 8 2006David L. Steward MD Abstract Objectives: Compare surgeon-performed ultrasound versus sestamibi for preoperative parathyroid adenoma localization. Study Design: Single-institutional cohort. Methods: One hundred six consecutive patients undergoing parathyroidectomy at an academic institution between 2004 to 2005 were included. Of those, 103 underwent both surgeon-performed ultrasound and sestamibi-Tc99m localization preoperatively. Primary outcome is sensitivity for adenoma localization to correct quadrant (right vs. left, superior vs. inferior). Results: Hypercalcemia resolved in 97% of patients. Sensitivities for correct quadrant localization for ultrasound versus sestamibi were 87% versus 58% (P < .001). Specificities were 95%. Positive and negative predictive values were 85% versus 78% and 96% versus 87%, respectively. Combined sensitivity was 93%. Sensitivities for correct side localization were 91% and 74% (P = .002). Conclusions: Ultrasound appears more sensitive than sestamibi for localization to correct quadrant or side when performed in-office by the author in this cohort. [source] Accuracy of Ottawa Ankle Rules to Exclude Fractures of the Ankle and Midfoot in Children: A Meta-analysisACADEMIC EMERGENCY MEDICINE, Issue 4 2009Shawn Dowling MD Abstract Objectives:, The objectives were to conduct a systematic review to determine the diagnostic accuracy of the Ottawa Ankle Rules (OAR) to exclude ankle and midfoot fractures in children and the extent to which x-ray use could be reduced without missing significant fractures. Methods:, The authors conducted comprehensive searches of electronic databases and gray literature sources. Independent reviewers applied standard inclusion and exclusion criteria. The criterion standard diagnostic test was an ankle and/or foot x-ray or proxy measure to ensure no missed fractures. Standard 2 × 2 tables were constructed. Sensitivities and specificities were pooled using an approximation of the inverse variance; 95% confidence intervals (95% CIs) were calculated using the exact method. Likelihood ratios (LR ±) and diagnostic odds ratios were combined under DerSimonian and Laird random effects model. Results:, A pooled analysis of 12 studies (N = 3,130) identified 671 fractures (prevalence = 21.4%). Ten studies reported Salter-Harris Type I (SH-I) fractures. The pooled sensitivity was 98.5% (95% CI = 97.3 to 99.2), suggesting that the OAR can be used to rule out a fracture. Four of 10 missed fractures were characterized: 1 SH-I, 1 SH-IV, and 2 "insignificant fractures" (either SH-I or avulsion fractures <3 mm). The pooled estimate for rate of x-ray reduction was 24.8% (95% CI = 23.3% to 26.3%; range = 5% to 44%). Conclusions:, The OAR appear to be a reliable tool to exclude fractures in children greater than 5 years of age presenting with ankle and midfoot injuries. Employing the OAR would significantly decrease x-ray use with a low likelihood of missing a fracture. [source] A Single Gene May Account For Individual SensitivitiesAUSTRALIAN ENDODONTIC JOURNAL, Issue 2 2000Article first published online: 11 FEB 2010 No abstract is available for this article. [source] Accuracy of clinical diagnosis of skin lesionsBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2008C.F. Heal Summary Background, Skin cancer is an increasing problem in fair-skinned populations worldwide. It is important that doctors are able to diagnose skin lesions accurately. Objectives, To compare the clinical with the histological diagnosis of excised skin lesions from a set of epidemiological data. We analysed diagnostic accuracy stratified by histological subtype and body site and examined the histological nature of misclassified diagnosis. Methods, All excised and histologically confirmed skin cancers in Townsville/Thuringowa, Australia from December 1996 to October 1999 were recorded. Positive predictive values (PPVs) and sensitivities were calculated for the clinical diagnoses and stratified by histological subtype and body site. Results, Skin excisions in 8694 patients were examined. PPVs for the clinical diagnoses were: basal cell carcinoma (BCC) 72·7%; squamous cell carcinoma (SCC) 49·4%; cutaneous melanoma (CM) 33·3%. Sensitivities for the clinical diagnosis were: BCC 63·9%; SCC 41·1%; CM 33·8%. For BCC, PPVs and sensitivities were higher for the trunk, the shoulders and the face and lower for the extremities. The reverse pattern was seen for SCCs. Conclusions, Diagnostic accuracy was highest for BCC, the most prevalent lesion. Most excisions were correctly diagnosed or resulted in the removal of malignant lesions. With nonmelanocytic lesions, doctors tended to misclassify benign lesions as malignant, but were less likely to do the reverse. Although a small number of clinically diagnosed common naevi subsequently proved to be melanoma (6·3%), a higher proportion of all melanomas had been classified as common naevi (20·9%). Accuracy of diagnosis was dependent on body site. [source] Rich Sensitivities: An Analysis of Conflict Among Women in Feminist Memoir,CANADIAN REVIEW OF SOCIOLOGY/REVUE CANADIENNE DE SOCIOLOGIE, Issue 2 2009JUDITH TAYLOR Alors que le mouvement nord-américain des femmes est surtout connu pour ses efforts en vue de transformer les relations sociales entre les femmes et les hommes, ses partisanes ont également mis l'accent sur la reformulation des relations entre les femmes. Utilisant une source de données novatrice, les mémoires du mouvement social, l'auteure souligne la profondeur de la déception que les féministes s'infligent les unes aux autres. Les mémorialistes débattent des notions provenant du mouvement et du courant principal voulant que les femmes soient compétentes socialement. Cet article présente le concept d'«idéation relationnelle» pour décrire la façon dont les mémorialistes féministes analysent d'une manière critique la compréhension de la socialité des femmes tenue pour acquise et aiguisent leurs désirs d'une nouvelle éthique sociale entre elles. While the North American women's movement is most known for its efforts to transform social relations between women and men, its adherents have also focused on remaking relations among women. Using an innovative data source, social movement memoir, this paper indicates the depth of disappointment feminists cause one another. Memoirists dispute notions found in the movement and mainstream that women are socially capable. The paper offers the concept "relational ideation" to describe the way feminist memoirists critically examine taken for granted understandings of women's sociality and amplify their desires for a new social ethic among them. [source] Derivation of a Triage Algorithm for Chest Radiography of Community-acquired Pneumonia Patients in the Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 1 2008Demetrios N. Kyriacou MD Abstract Background:, Community-acquired pneumonia (CAP) accounts for 1.5 million emergency department (ED) patient visits in the United States each year. Objectives:, To derive an algorithm for the ED triage setting that facilitates rapid and accurate ordering of chest radiography (CXR) for CAP. Methods:, The authors conducted an ED-based retrospective matched case,control study using 100 radiographic confirmed CAP cases and 100 radiographic confirmed influenzalike illness (ILI) controls. Sensitivities and specificities of characteristics assessed in the triage setting were measured to discriminate CAP from ILI. The authors then used classification tree analysis to derive an algorithm that maximizes sensitivity and specificity for detecting patients with CAP in the ED triage setting. Results:, Temperature greater than 100.4°F (likelihood ratio = 4.39, 95% confidence interval [CI] = 2.04 to 9.45), heart rate greater than 110 beats/minute (likelihood ratio = 3.59, 95% CI = 1.82 to 7.10), and pulse oximetry less than 96% (likelihood ratio = 2.36, 95% CI = 1.32 to 4.20) were the strongest predictors of CAP. However, no single characteristic was adequately sensitive and specific to accurately discriminate CAP from ILI. A three-step algorithm (using optimum cut points for elevated temperature, tachycardia, and hypoxemia on room air pulse oximetry) was derived that is 70.8% sensitive (95% CI = 60.7% to 79.7%) and 79.1% specific (95% CI = 69.3% to 86.9%). Conclusions:, No single characteristic adequately discriminates CAP from ILI, but a derived clinical algorithm may detect most radiographic confirmed CAP patients in the triage setting. Prospective assessment of this algorithm will be needed to determine its effects on the care of ED patients with suspected pneumonia. [source] The influence of age, sex, race, refractive error and optic disc parameters on the sensitivity and specificity of scanning laser polarimetryACTA OPHTHALMOLOGICA, Issue 4 2004Vital P. Costa Abstract. Purpose:,To evaluate the influence of age, sex, race, refractive error and optic disc topography on the sensitivity and specificity of scanning laser polarimetry (SLP) in the diagnosis of glaucoma. Methods:,A total of 88 normal individuals and 95 glaucoma patients were included in this study. Glaucoma was defined on the basis of both optic nerve damage and visual field defects. Scanning laser polarimetry, optic disc topography, automated perimetry and refractometry were performed in all subjects. The sensitivity and specificity of SLP were assessed applying a previously calculated cut-off to a previously described linear discriminant function (LDF). Results:,The sensitivity and specificity of SLP in the study population were 82% and 83%, respectively. Sensitivity and specificity were not affected by age, sex, race, average disc diameter or disc area. The sensitivity of SLP tended to be higher in myopes (93%) than in emmetropes (80%) and hyperopes (71%) (p = 0.08). Sensitivities were higher in individuals with cup areas > 0.96 mm2 (89%), rim areas , 1.36 mm2 (92%), and cup area/disc area ratios > 0.45 (89%) (p < 0.05). Stepwise logistic regression analysis indicated that the presence of a cup area > 0.96 mm2 and a rim area < 1.36 mm2 significantly increased the sensitivity of the LDF, whereas a cup area/disc area ratio , 0.45 significantly increased the specificity of the LDF. Conclusion:,The sensitivity and specificity of SLP may be influenced by refractive error and optic disc parameters that are affected by glaucomatous damage (cup area, rim area and cup area/disc area ratio). These parameters must be considered in studies evaluating the sensitivity and specificity of optic nerve/retinal nerve fibre layer imaging technologies. [source] | ||||||||||||||||||||||||||||||||||||||||||||||