Efficiency in the diagnosis of acute pancreatitis increased by improved electrophoresis of amylase isoenzyme P3 on cellulose acetate.

1985 ◽  
Vol 31 (1) ◽  
pp. 70-75 ◽  
Author(s):  
T H Massey
Keyword(s):  
Acute Pancreatitis ◽  
Complete Resolution ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
True Positive Rate ◽  
Diagnostic Efficiency ◽  
Electrophoretic Method ◽  
Diagnostic Potential ◽  
Positive Rate ◽  
Positive Results

Abstract Serum from patients who have suffered acute pancreatitis contains P3, an isoenzyme of pancreatic-derived amylase (EC 3.2.1.1). Heretofore, complete resolution of P3 from the major salivary isoenzyme in serum, S1, has not been possible, thus compromising the diagnostic potential of P3 for pancreatitis. I describe an electrophoretic method for the essentially complete resolution of P3 from S1 by including CaCl2, 1 mmol/L, in the Tris barbiturate electrophoresis buffer (25 mmol/L, pH 8.8). I evaluated the clinical utility of the method for 129 consecutive patients suspected of having pancreatitis, by using receiver operating characteristic curve analysis for results for total amylase, P2, and P3 activity. For a true-positive rate of 90% with a prevalence of pancreatitis of 7.8%, the diagnostic efficiency was increased from 82% (total amylase) to 91% (P2) to 98% (P3). Thus, including P3 activity in the diagnostic criteria will eliminate most false-positive results for pancreatitis based on total amylase activity alone, and should decrease the need for expensive radiologic procedures currently required to confirm the presence of pancreatitis. I conclude that P3 can be of significant value in the differential diagnosis of pancreatitis from other syndromes with hyperamylasemia.

Amylase, lipase, pancreatic isoamylase, and phospholipase A in diagnosis of acute pancreatitis

1995 ◽  
Vol 41 (8) ◽  
pp. 1129-1134 ◽  
Author(s):  
P Clavé ◽  
S Guillaumes ◽  
I Blanco ◽  
N Nabau ◽  
J Mercé ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Operating Characteristic ◽  
Serum Amylase ◽  
Acute Abdominal Pain ◽  
Characteristic Curve ◽  
Threshold Value ◽  
Phospholipase A ◽  
Diagnostic Efficiency ◽  
Pancreatic Isoamylase ◽  
Parallel Fashion

Abstract To determine the utility of serum amylase (AMY), lipase (Lp), pancreatic isoamylase (isoA), phospholipase A (PLA), and urine AMY in the diagnosis of acute pancreatitis, samples of serum and urine were obtained on admission and every day thereafter for 5 days from 384 patients with acute abdominal pain. Diagnostic accuracy, determined as the area under the receiver operating characteristic curve, was > 0.975 for serum AMY, Lp, isoA, and urine AMY. For each of these enzymes, a threshold value (twice to sixfold the upper limit of the reference values) offering diagnostic efficiency > 95% could be determined. In contrast, accuracy and efficiency of serum PLA were low. The profiles of these enzymes in acute pancreatitis decreased in a parallel fashion over 5 days except for PLA. We conclude that diagnostic utilities are similar for serum AMY, Lp, isoA, and urine AMY for acute pancreatitis, provided that an appropriate threshold is established.

scholarly journals Are sniffer dogs a reliable approach for diagnosing SARS-CoV-2 infection?

Diagnosis ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Giuseppe Lippi ◽  
Camilla Mattiuzzi ◽  
Brandon M. Henry
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Pooled Analysis ◽  
Diagnostic Efficiency ◽  
Diagnostic Specificity ◽  
Summary Receiver Operating Characteristic ◽  
Electronic Search ◽  
Individual Variations ◽  
Infected Material

Abstract Objectives Despite inter-individual variations in their diagnostic efficiency, dogs have been trained to investigate many human pathologies, especially cancer, diabetes, migraine, seizures and even infectious diseases. To this end, we performed a critical review and pooled analysis of current scientific literature on the performance of dogs trained for identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive human specimens. Methods We carried out an electronic search in PubMed, Scopus and Web of Science with the keywords “dog(s)” AND “sniffer” OR “scent” OR “smell” AND “SARS-CoV-2” OR “severe acute respiratory syndrome coronavirus 2” OR “coronavirus disease 2019” OR “COVID-19” within all fields, without date or language restrictions, to identify studies describing dogs’ performance for identifying SARS-CoV-2 infected material. Results Three studies could be finally included in pooled analysis, totaling 17 dogs (47% females), aged between 0.5 and 12 years. The pooled diagnostic sensitivity was 0.88 (95% CI, 0.84–0.91; I 2, 85.3%), the diagnostic specificity 0.99 (95% CI, 0.99–0.99; I 2, 97.4%), whilst the area under the summary receiver operating characteristic curve (SROC) was 0.979 (standard error, 0.003). Conclusions The notable performance observed in this pooled analysis would persuade us to suggest that adequately trained dogs could represent an intriguing and sustainable resource for purposes of rapid SARS-CoV-2 mass screening.

Considerations on the region of interest in the ROC space

2021 ◽  
pp. 096228022110605
Author(s):  
Luigi Lavazza ◽  
Sandro Morasca
Keyword(s):  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
False Positive Rate ◽  
Area Under The Curve ◽  
Region Of Interest ◽  
True Positive Rate ◽  
True Positive ◽  
Receiver Operating Characteristic Curves ◽  
Positive Rate ◽  
Receiver Operating

Receiver Operating Characteristic curves have been widely used to represent the performance of diagnostic tests. The corresponding area under the curve, widely used to evaluate their performance quantitatively, has been criticized in several respects. Several proposals have been introduced to improve area under the curve by taking into account only specific regions of the Receiver Operating Characteristic space, that is, the plane to which Receiver Operating Characteristic curves belong. For instance, a region of interest can be delimited by setting specific thresholds for the true positive rate or the false positive rate. Different ways of setting the borders of the region of interest may result in completely different, even opposing, evaluations. In this paper, we present a method to define a region of interest in a rigorous and objective way, and compute a partial area under the curve that can be used to evaluate the performance of diagnostic tests. The method was originally conceived in the Software Engineering domain to evaluate the performance of methods that estimate the defectiveness of software modules. We compare this method with previous proposals. Our method allows the definition of regions of interest by setting acceptability thresholds on any kind of performance metric, and not just false positive rate and true positive rate: for instance, the region of interest can be determined by imposing that [Formula: see text] (also known as the Matthews Correlation Coefficient) is above a given threshold. We also show how to delimit the region of interest corresponding to acceptable costs, whenever the individual cost of false positives and false negatives is known. Finally, we demonstrate the effectiveness of the method by applying it to the Wisconsin Breast Cancer Data. We provide Python and R packages supporting the presented method.

The Utility of Pleural Fluid Lactate Dehydrogenase to Adenosine Deaminase Ratio in Pleural Tuberculosis

Respiration ◽  
2020 ◽  
pp. 1-5
Author(s):  
Amanda Beukes ◽  
Jane Alexandra Shaw ◽  
Andreas H. Diacon ◽  
Elvis M. Irusen ◽  
Coenraad F.N. Koegelenberg
Keyword(s):  
Lactate Dehydrogenase ◽  
Adenosine Deaminase ◽  
Pleural Fluid ◽  
Operating Characteristic ◽  
Retrospective Studies ◽  
Characteristic Curve ◽  
Diagnostic Efficiency ◽  
Pleural Tuberculosis ◽  
High Incidence ◽  
The Mean

In high-burden settings, the diagnosis of pleural tuberculosis (TB) is frequently inferred in patients who present with lymphocyte predominant exudative effusions and high adenosine deaminase (ADA) levels. Two recent small retrospective studies suggested that the lactate dehydrogenase (LDH)/ADA ratio is significantly lower in TB than in non-TB pleural effusions and that the LDH/ADA ratio may be useful in differentiating pleural TB from other pleural exudates. We compared the pleural LDH/ADA ratios, ADA levels, and lymphocyte predominance of a prospectively collected cohort of patients with proven pleural TB (<i>n</i> = 160) to those with a definitive alternative diagnosis (<i>n</i> = 68). The mean pleural fluid LDH/ADA ratio was lower in patients with pleural TB than alternative diagnoses (6.2 vs. 34.3, <i>p</i> &#x3c; 0.001). The area under the receiver operating characteristic curve was 0.92 (<i>p</i> &#x3c; 0.001) for LDH/ADA ratio and 0.88 (<i>p</i> &#x3c; 0.001) for an ADA ≥40 U/L alone. A ratio of ≤12.5 had the best overall diagnostic efficiency, while a ratio of ≤10 had a specificity of 90% and a positive predictive value of 95%, with a sensitivity of 78%, making it a clinically useful “rule in” value for pleural TB in high incidence settings. When comparing the LDH/ADA ratio to an ADA level ≥40 U/L in the presence of a lymphocyte predominant effusion, the latter performed better. When lymphocyte values are unavailable, our data suggest that the LDH/ADA ratio is valuable in distinguishing TB effusions from other pleural exudates.

scholarly journals Triglyceride to HDL-C Ratio Is Associated with Plasma D-Dimer Levels in Different Types of Pancreatitis: A Retrospective Single-Centered Study in China

2022 ◽  
Author(s):  
Xiaoqing Jia ◽  
Xiaoting Zhang ◽  
Dalong Sun ◽  
Rong Li ◽  
Na Yang ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Control Group ◽  
Recurrent Acute Pancreatitis ◽  
Significant Difference ◽  
Different Types ◽  
Coefficient Corrélation ◽  
The Relationship ◽  
D Dimer

Abstract BackgroundThis study aims to evaluate the relationship between D-dimer and dyslipidemia, especially triglyceride to HDL-C ratio (TG/HDL-C) in different types of pancreatitis. We analyzed the D-dimer and dyslipidemia levels in acute pancreatitis (AP), recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP). Material and MethodsA single-centered retrospective study was conducted on 1013 patients diagnosed with AP, RAP or CP. Only patients hospitalized within 24 h of onset were included, and 204 patients were enrolled in pancreatitis groups. 68 normal persons without pancreatitis, malignant diseases, pregnancy, or organ failure, who had health check-ups, were enrolled in the control group. Blood samples were taken within 24h of admission. The epidemiology and etiology were analyzed. D-dimer and dyslipidemia levels were compared between different types of pancreatitis. Furthermore, the area under the receiver-operating characteristic curve (AUC) was used to estimate the validity of the predictor and to define optimal cut-off points for prediction.ResultsWe found that D-dimer and TG/HDL-C ratio could distinguish mild AP (MAP) and non-MAP in AP and RAP patients. The D-dimer level was related to TG/HDL-C ratio and severity of pancreatitis, with the coefficient correlation of 0.379 and 0.427(p<0.01), respectively. TG/HDL-C was related to D-dimer in different types of pancreatitis. Multivariate analysis was conducted in the parameters at admission like alcohol abuse, dyslipidemia and coagulation disturbance in distinguishing AP and RAP groups from the control group, and the parameter like diabetes in RAP and CP groups significantly increased compared with that of the control group. ConclusionsThe value of D-dimer level and TG/HDL-C ratio in predicting the severity of AP and RAP was confirmed but there was no significant difference between CP group and the control group. The D-dimer level was related to dyslipidemia and TG/HDL-C ratio.

scholarly journals Evaluation on the Diagnostic Efficiency of Different Methods in Detecting COVID-19.

2020 ◽  
Author(s):  
Haitao Yang ◽  
Yuzhu Lan ◽  
Xiujuan Yao ◽  
Sheng Lin ◽  
Baosong Xie
Keyword(s):  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Web Of Science ◽  
Characteristic Curve ◽  
Positive Likelihood Ratio ◽  
Diagnostic Odds Ratio ◽  
Diagnostic Efficiency ◽  
Summary Receiver Operating Characteristic ◽  
Operating Characteristic Curve ◽  
Higher Sensitivity

Abstract Objective: To evaluate the diagnostic efficiency of different methods in detecting COVID-19.Methods: PubMed, Web of Science and Embase databases were searched for identifing eligible articles. All data were calculated utilizing Meta Disc 1.4, Revman 5.3.2 and Stata 12. The diagnostic efficiency was assessed via these indicators including summary sensitivity and specificity, positive likelihood ratio (PLR), negative LR (NLR), diagnostic odds ratio (DOR), summary receiver operating characteristic curve (sROC) and calculate the AUC. Results: 18 articles (3648 cases) were included. EPlex: pooled sensitivity was 0.94; specificity 1.0; PLR 90.91; NLR 0.07; DOR 1409.49; AUC=0.9979, Q*=0.9840. Panther Fusion: pooled sensitivity was 0.99; specificity 0.98; PLR 42.46; NLR 0.02; DOR 2300.38; AUC=0.9970, Q*=0.9799. Simplexa: pooled sensitivity was 1.0; specificity 0.97; PLR 26.67; NLR 0.01; DOR 3100.93; AUC=0.9970, Q*=0.9800. Cobas®: pooled sensitivity was 0.99; specificity 0.96; PLR 37.82; NLR 0.02; DOR 3754.05; AUC=0.9973, Q*=0.9810. RT-LAMP: pooled sensitivity was 0.98; specificity 0.99; PLR 36.22; NLR 0.04; DOR 751.24; AUC=0.9905, Q*=0.9596. Xpert Xpress: pooled sensitivity was 0.99; specificity 0.97; PLR 27.44; NLR 0.01; DOR 3488.15; AUC=0.9977, Q*=0.9829.Conclusions: These methods (ePlex, Panther Fusion, Simplexa, Cobas®, RT-LAMP and Xpert Xpress) bear higher sensitivity and specificity, and might be efficient methods complement to the gold standard.

scholarly journals Copeptin in the Differential Diagnosis of Hyponatremia

2009 ◽  
Vol 94 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Wiebke Fenske ◽  
Stefan Störk ◽  
Anne Blechschmidt ◽  
Sebastian G. K. Maier ◽  
Nils G. Morgenthaler ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Prospective Observational Study ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Urine Osmolality ◽  
Close Correlation ◽  
Correct Treatment ◽  
Primary Polydipsia ◽  
Diagnostic Potential ◽  
Healthy Control

Abstract Background: Treatment of patients with hyponatremia varies widely; thus, convenient diagnostic parameters are needed to guide the correct treatment strategy. This study was designed to evaluate the diagnostic potential of copeptin, the C-terminal part of provasopressin, as a new marker in the differential diagnosis of hyponatremia. Methods: In this prospective observational study, 106 consecutive hyponatremic patients were classified based on their history, clinical evaluation, and laboratory tests. In patients and 32 healthy control subjects, plasma copeptin concentration and standard biochemical parameters were tested for their utility of diagnosing the syndrome of inappropriate antidiuresis (SIAD). Results: Four patients (4%) were diagnosed as primary polydipsia, nine (8%) as diuretic-induced hyponatremia, 42 (40%) as SIAD, 29 (27%) as hypovolemic hyponatremia, and 22 patients (21%) as hypervolemic hyponatremia. In controls, a close correlation between plasma copeptin and serum sodium (r2 = 0.62, P &lt; 0.001) or urine osmolality (r2 = 0.39, P = 0.001) was observed. Plasma copeptin levels were significantly higher in patients with hypo- and hypervolemic hyponatremia compared with SIAD (P &lt; 0.005, respectively) and primary polydipsia (P &lt; 0.001). The copeptin to U-Na ratio differentiated accurately between volume-depleted and normovolemic disorders (area under the receiver-operating characteristic curve 0.88, 95% confidence interval 0.81–0.95; P &lt; 0.001), resulting in a sensitivity and specificity of 85 and 87% if a cutoff value of 30 pmol/mmol was used. The combined information of plasma copeptin less than 3 pmol/liter and urine osmolality less than 200 mOsm/kg ensured primary polydipsia in 100% of suspected patients. Conclusion: Copeptin measurement reliably identifies patients with primary polydipsia but has limited utility in the differential diagnosis of other hyponatremic disorders. In contrast, the copeptin to U-Na ratio is superior to the reference standard in discriminating volume-depleted from normovolemic hyponatremic disorders.

scholarly journals Accuracy of new Corvis ST parameters for detecting subclinical and clinical keratoconus eyes in a Chinese population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shengwei Ren ◽  
Liyan Xu ◽  
Qi Fan ◽  
Yuwei Gu ◽  
Kaili Yang
Keyword(s):  
Receiver Operating Characteristic Curve ◽  
Chinese Population ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Youden Index ◽  
Diagnostic Efficiency ◽  
Stiffness Parameter ◽  
Diagnostic Ability ◽  
Corvis St ◽  
Operating Characteristic Curve

AbstractThis study aimed to compare the values of new corneal visualization Scheimpflug technology (Corvis ST) parameters in normal, subclinical keratoconus (SKC) and keratoconus (KC) eyes, and evaluate the diagnostic ability to distinguish SKC and KC eyes from normal eyes. One-hundred normal, 100 SKC and 100 KC eyes were included in the study. Corvis ST parameters containing dynamic corneal response parameters were measured by one ophthalmologist. The receiver operating characteristic curve was used to evaluate the diagnostic ability of new Corvis ST parameters. The new Corvis ST parameters in KC eyes were different from those in the control and SKC eyes after adjusting for IOP and CCT, and stiffness parameter at the first applanation (SP-A1) and Corvis biomechanical index (CBI) were significantly different between the control and SKC eyes (all P < 0.05). The parameter with the highest diagnostic efficiency was SP-A1 (Youden index = 0.40, AUC = 0.753), followed by CBI (Youden index = 0.38, AUC = 0.703), and Integrated Radius (Youden index = 0.33, AUC = 0.668) in diagnosing SKC from control eyes. New Corvis ST parameters in SKC eyes were significantly different from normal control and KC eyes, and could be considered to distinguish SKC and KC eyes from normal eyes.

scholarly journals Semi-Supervised Learning for Maximizing the Partial AUC

2020 ◽  
Vol 34 (04) ◽  
pp. 4239-4246
Author(s):  
Tomoharu Iwata ◽  
Akinori Fujino ◽  
Naonori Ueda
Keyword(s):  
Supervised Learning ◽  
Binary Classification ◽  
Characteristic Curve ◽  
False Positive Rate ◽  
True Positive Rate ◽  
Unlabeled Data ◽  
Spam Filtering ◽  
Classification Problems ◽  
Partial Area ◽  
Positive Rate

The partial area under a receiver operating characteristic curve (pAUC) is a performance measurement for binary classification problems that summarizes the true positive rate with the specific range of the false positive rate. Obtaining classifiers that achieve high pAUC is important in a wide variety of applications, such as cancer screening and spam filtering. Although many methods have been proposed for maximizing the pAUC, existing methods require many labeled data for training. In this paper, we propose a semi-supervised learning method for maximizing the pAUC, which trains a classifier with a small amount of labeled data and a large amount of unlabeled data. To exploit the unlabeled data, we derive two approximations of the pAUC: the first is calculated from positive and unlabeled data, and the second is calculated from negative and unlabeled data. A classifier is trained by maximizing the weighted sum of the two approximations of the pAUC and the pAUC that is calculated from positive and negative data. With experiments using various datasets, we demonstrate that the proposed method achieves higher test pAUCs than existing methods.

scholarly journals Skin imprints to provide noninvasive metabolic profiling of COVID-19 patients

2021 ◽  
Author(s):  
Jeany Delafiori ◽  
Rinaldo Focaccia Siciliano ◽  
Arthur Noin de Oliveira ◽  
José Carlos Nicolau ◽  
Geovana Manzan Sales ◽  
...  
Keyword(s):  
Operating Characteristic ◽  
Characteristic Curve ◽  
Endocannabinoid System ◽  
Skin Lesions ◽  
Routine Care ◽  
Fatty Acid Amides ◽  
Non Invasive ◽  
Diagnostic Potential ◽  
Curve Model ◽  
System Maintenance

As the current COVID-19 pandemic progresses, more symptoms and signals related to how the disease manifests in the human body arise in the literature. Skin lesions and coagulopathies may be confounding factors on routine care and patient management. We analyzed the metabolic and lipidic profile of the skin from COVID-19 patients using imprints in silica plates as a non-invasive alternative, in order to better understand the biochemical disturbances caused by SARS-CoV-2 in the skin. One hundred and one patients (64 COVID-19 positive patients and 37 control patients) were enrolled in the study from April 2020 to June 2020 during the first wave of COVID-19 in São Paulo, Brazil. Fourteen biomarkers were identified related to COVID-19 infection (7 increased and 7 decreased in COVID-19 patients). Remarkably, oleamide has shown promising performance, providing 79.0% of sensitivity on a receiver operating characteristic curve model. Species related to coagulation and immune system maintenance such as phosphatidylserines were decreased in COVID-19 patients; on the other hand, cytokine storm and immunomodulation may be affected by molecules increased in the COVID-19 group, particularly primary fatty acid amides and N-acylethanolamines, which are part of the endocannabinoid system. Our results show that skin imprints may be a useful, noninvasive strategy for COVID-19 screening, by electing a pool of biomarkers with diagnostic potential.

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