scholarly journals ELISA and Fourier-transform infrared spectroscopy

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Alejandro Clavijo-Maldonado ◽  
Enio Ferreira ◽  
Jorge E. Pérez-Cárdenas ◽  
Carlos Vargas- Hernández ◽  
Fredy A. Rivera-Páez
Keyword(s):  
Gene Expression ◽  
Infrared Spectroscopy ◽  
Blood Serum ◽  
Primary Tumour ◽  
Area Under The Curve ◽  
Roc Curves ◽  
Human Detection ◽  
Serum Samples ◽  
Her2 Gene ◽  
Her2 Protein

ELISA and FTIR assay techniques were used to identify HER2 gene expression in the blood serum of female dogs and to characterise the biochemical composition. ELISA tests assess the stage of primary tumour development and evolution, while FTIR allows for a complete characterisation of biomolecules associated with the tumoral process. Blood serum samples from 30 female dogs were analysed. Concentrations of the HER2/neu protein were detected using ELISA kits specific for canine and human detection. Infrared spectroscopy (IR) was conducted in absorbance mode at a frequency range of 400–4000 cm-1 and a resolution of 4 cm-1 over 50 scans. The ELISA cut-off for HER2 protein concentration in blood serum was determined using the receiver operating characteristic (ROC) curve and by estimating the area under the curve (AUC) at a 95% confidence interval (CI=95%). The ROC curves in the canine and human ELISA tests were 0.75 and 0.45, respectively. The representative IR spectra for HER2 gene expression corresponded to lipids (1161 cm-1, 1452 cm-1, 2851 cm-1). This study contributes to the knowledge of HER2 through the identification of biochemical features associated with the changes in the HER2/neu+ and HER2/neu- states.

scholarly journals Two-Component Cluster Analysis of a Large Serodiagnostic Database for Specificity of Increases of IgG Antibodies against Pertussis Toxin in Paired Serum Samples and of Absolute Values in Single Serum Samples

2012 ◽  
Vol 19 (9) ◽  
pp. 1452-1456 ◽  
Author(s):  
Sabine C. de Greeff ◽  
Peter Teunis ◽  
Hester E. de Melker ◽  
Frits R. Mooi ◽  
Daan W. Notermans ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Pertussis Toxin ◽  
Area Under The Curve ◽  
Roc Curves ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Pertussis Infection ◽  
Diagnostic Laboratory ◽  
Two Component

ABSTRACTMeasuring IgG antibodies against pertussis toxin (IgG-Ptx) with an enzyme-linked immunosorbent assay (ELISA) can be used to diagnose pertussis infection; however, the cutoff points are not unanimously defined. To determine the diagnostic specificity of increases of IgG-Ptx in paired sera and of absolute values in single serum samples, we applied a two-component cluster analysis to serum samples of patients suspected for pertussis, whose sera had been submitted to a routine diagnostic laboratory between 2003 and 2009, and had been assayed with an in-house IgG-Ptx ELISA calibrated with the international FDA lot 3 IgG-Ptx reference serum. Children eligible for the acellular pertussis vaccination were excluded to avoid interference from a vaccine-induced IgG-Ptx rise. Binary distribution mixtures were fitted to the data. Receiver operating characteristic (ROC) curves were calculated for absolute values in single samples (n= 14,452) and increases in paired samples (n= 2,455). For both parameters, two subpopulations could be identified: a population with high reactivity (persons with pertussis infection) and a population with low reactivity (persons without pertussis infection). For absolute values in single samples, the area under the curve (AUC) of the ROC curve was 0.993 and the optimum cutoff (with the highest cumulative value of specificity plus sensitivity) was 67.7 IU/ml (95% confidence interval, 63.9 to 74.1; sensitivity, 96.4%; specificity, 95.7%). A previously determined diagnostic cutoff of 125 IU/ml was associated with a sensitivity of 88.1% and a specificity of 98.8%. For increases in paired sera, the AUC was 0.999 and the optimum cutoff was 3.1-fold (95% CI, 2.8 to 3.4; sensitivity, 99.6%; specificity, 99.2%). Given the methodology of this study, estimates of sensitivity probably are overrated (because pertussis patients without IgG-Ptx response are not detected), but estimates of specificities can be considered very accurate.

scholarly journals Urinary beta-trace protein gene expression analysis in type 2 diabetes mellitus patients

2017 ◽  
Vol 15 (4) ◽  
pp. 441-444
Author(s):  
Marcelo Rodrigues Bacci ◽  
Beatriz da Costa Aguiar Alves ◽  
Marina Romera Cavallari ◽  
Ligia Ajaime Azzalis ◽  
Ross Martin de Rozier-Alves ◽  
...  
Keyword(s):  
Gene Expression ◽  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Protein Gene ◽  
Area Under The Curve ◽  
Roc Curves ◽  
Diabetic Patients ◽  
Glucose Levels

ABSTRACT Objective: To evaluate the gene expression of beta-trace protein in urine of diabetic patients, with no reduction in glomerular filtration rate, which was defined as below 60mL/min/1.73m2. Methods: Type 2 diabetes mellitus patients were recruited, and a group of non-diabetic individuals served as control. Beta-trace protein gene expression was analyzed by quantitative PCR. Blood samples were collected to establish glucose levels and baseline kidney function. Accuracy was analyzed using ROC curves. Results: Ninety type 2 diabetes mellitus patients and 20 non-diabetic individuals were recruited. The area under the curve was 0.601, sensitivity of 20% and specificity of 89.47%. Among diabetic participants, 18% showed an expression above the cutoff point. Conclusion: These results of accuracy of beta-trace protein gene expression in urine of diabetic patients are promising, although they did not achieve a higher area under the curve level.

Diagnostic accuracy and comparison of two assays for Borrelia-specific IgG and IgM antibodies: proposals for statistical evaluation methods, cut-off values and standardization

2013 ◽  
Vol 62 (12) ◽  
pp. 1835-1844 ◽  
Author(s):  
Ram Benny Dessau
Keyword(s):  
Area Under The Curve ◽  
Roc Curves ◽  
Statistical Testing ◽  
Serological Response ◽  
Test Interpretation ◽  
Serum Samples ◽  
Discriminatory Ability ◽  
Proper Comparison ◽  
Specific Igg ◽  
Positive Results

Two assays (Liaison, Diasorin; IDEIA, Oxoid) for detection of Borrelia-specific antibodies were compared. A case–control design using patients with neuroborreliosis (n = 48), laboratory defined by a positive Borrelia-specific antibody index in the spinal fluid, was available and was intended to represent the serological response of disseminated early Lyme borreliosis in general. Serum samples were obtained from 216 Danish blood donors as controls. By comparing sensitivity and specificity using pre-specified cut-off values, significant differences were found. However, using receiver operating characteristic (ROC) curves to optimize and standardize test interpretation, it was shown that testing with both IDEIA IgG and IgM was comparable to testing with Liaison IgG alone by comparing the area under the curve of the diagnostically relevant 25 % partial ROC curve (P = 0.1). When using the Liaison OspC/VlsE IgM assay, the specificity was decreased without a gain in sensitivity. This study proposes standardizing of reporting by using a control population as the reference and choosing decision thresholds guided by the risk of false-positive results at 2 and 8 %. The sensitivities for IDEIA (IgG and IgM combined) were 85 and 95 % and for the Liaison (VlsE IgG) method were 67 and 96 %, respectively. Methods for test evaluation, test interpretation and statistical testing are presented and discussed. In conclusion, Liaison VlsE IgG alone and IDEIA IgG/IgM combined showed a high and comparable discriminatory ability to distinguish serum samples from patients with neuroborreliosis from blood donor controls. However, cut-off values should be adjusted for a proper comparison.

Evaluation of the clot burden score (cbs) for acute ischemic stroke (ais) in intent-to-treat patients.

2019 ◽  
Vol 1 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Sarah Yaziz ◽  
Ahmad Sobri Muda ◽  
Wan Asyraf Wan Zaidi ◽  
Nik Azuan Nik Ismail
Keyword(s):  
Ischemic Stroke ◽  
Clinical Outcome ◽  
Acute Ischemic Stroke ◽  
Predictive Value ◽  
Area Under The Curve ◽  
Rank Correlation ◽  
Treatment Decision ◽  
Roc Curves ◽  
Significant Negative Correlation ◽  
Clot Burden

Background : The clot burden score (CBS) is a scoring system used in acute ischemic stroke (AIS) to predict patient outcome and guide treatment decision. However, CBS is not routinely practiced in many institutions. This study aimed to investigate the feasibility of CBS as a relevant predictor of good clinical outcome in AIS cases. Methods:  A retrospective data collection and review of AIS patients in a teaching hospital was done from June 2010 until June 2015. Patients were selected following the inclusion and exclusion criteria. These patients were followed up after 90 days of discharge. The Modified Rankin scale (mRS) was used to assess their outcome (functional status). Linear regression Spearman Rank correlation was performed between the CBS and mRS. The quality performance of the correlations was evaluated using Receiver operating characteristic (ROC) curves. Results: A total of 89 patients with AIS were analysed, 67.4% (n=60) male and 32.6% (n=29) female. Twenty-nine (29) patients (33.7%) had a CBS ?6, 6 patients (6.7%) had CBS <6, while 53 patients (59.6%) were deemed clot free. Ninety (90) days post insult, clinical assessment showed that 57 (67.6%) patients were functionally independent, 27 (30.3%) patients functionally dependent, and 5 (5.6%) patients were deceased. Data analysis reported a significant negative correlation (r= -0.611, p<0.001). ROC curves analysis showed an area under the curve of 0.81 at the cut-off point of 6.5. This showed that a CBS of more than 6 predicted a good mRS clinical outcome in AIS patients; with sensitivity of 98.2%, specificity of 53.1%, positive predictive value (PPV) of 76%, and negative predictive value (NPV) of 21%. Conclusion: CBS is a useful additional variable for the management of AIS cases, and should be incorporated into the routine radiological reporting for acute ischemic stroke (AIS) cases.

scholarly journals Sphingolipid Analysis Indicate Lactosylceramide as a Potential Biomarker of Inflammatory Bowel Disease in Children

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1083
Author(s):  
Aleksandra Filimoniuk ◽  
Agnieszka Blachnio-Zabielska ◽  
Monika Imierska ◽  
Dariusz Marek Lebensztejn ◽  
Urszula Daniluk
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
High Performance ◽  
Area Under The Curve ◽  
Study Groups ◽  
Diagnostic Value ◽  
Serum Samples ◽  
Specificity And Sensitivity ◽  
Potential Biomarker ◽  
Inflammatory Bowel

An altered ceramide composition in patients with inflammatory bowel disease (IBD) has been reported recently. The aim of this study was to evaluate the concentrations of sphingolipids in the serum of treatment-naive children with newly diagnosed IBD and to determine the diagnostic value of the tested lipids in pediatric IBD. The concentrations of sphingolipids in serum samples were evaluated using a quantitative method, an ultra-high-performance liquid chromatography-tandem mass spectrometry in children with Crohn’s disease (CD) (n=34), ulcerative colitis (UC) (n = 39), and controls (Ctr) (n = 24). Among the study groups, the most significant differences in concentrations were noted for C16:0-LacCer, especially in children with CD compared to Ctr or even to UC. Additionally, the relevant increase in C20:0-Cer and C18:1-Cer concentrations were detected in both IBD groups compared to Ctr. The enhanced C24:0-Cer level was observed only in UC, while C18:0-Cer only in the CD group. The highest area under the curve (AUC), specificity, and sensitivity were determined for C16:0-LacCer in CD diagnosis. Our results suggest that the serum LacC16-Cer may be a potential biomarker that distinguishes children with IBD from healthy controls and differentiates IBD subtypes. In addition, C20:0-Cer and C18:0-Cer levels also seem to be closely connected with IBD.

scholarly journals Gene expression-based biomarkers designating glioblastomas resistant to multiple treatment strategies

2021 ◽  
Author(s):  
Otília Menyhárt ◽  
János Tibor Fekete ◽  
Balázs Győrffy
Keyword(s):  
Gene Expression ◽  
Treatment Strategies ◽  
Area Under The Curve ◽  
Predictive Biomarkers ◽  
Subsequent Treatment ◽  
Survival Status ◽  
Multiple Treatment ◽  
Post Surgery ◽  
Potential Biomarker ◽  
Elevated Expression

Abstract Despite advances in molecular characterization of glioblastoma multiforme (GBM), only a handful of predictive biomarkers exist with limited clinical relevance. We aimed to identify differentially expressed genes in tumor samples collected at surgery associated with response to subsequent treatment, including temozolomide (TMZ) and nitrosoureas. Gene expression was collected from multiple independent datasets. Patients were categorized as responders/nonresponders based on their survival status at 16 months post-surgery. For each gene, the expression was compared between responders and nonresponders with a Mann-Whitney U test and receiver operating characteristic. The package "roc" was used to calculate the area under the curve (AUC). The integrated database comprises 454 GBM patients from three independent datasets and 10,103 genes. The highest proportion of responders (68%) were among patients treated with TMZ combined with nitrosoureas, where FCGR2B upregulation provided the strongest predictive value (AUC=0.72, p &lt; 0.001). Elevated expression of CSTA and MRPS17 was associated with a lack of response to multiple treatment strategies. DLL3 upregulation was present in subsequent responders to any treatment combination containing TMZ. Three genes (PLSCR1, MX1, and MDM2) upregulated both in the younger cohort and in patients expressing low MGMT delineate a subset of patients with worse prognosis within a population generally associated with a favorable outcome. The identified transcriptomic changes provide biomarkers of responsiveness, offer avenues for preclinical studies, and may enhance future GBM patient stratifications. The described methodology provides a reliable pipeline for the initial testing of potential biomarker candidates for future validation studies.

scholarly journals Magnetic resonance cisternography imaging findings related to the leakage of Gadolinium into the subarachnoid space

2021 ◽  
Author(s):  
Rei Nakamichi ◽  
Toshiaki Taoka ◽  
Hisashi Kawai ◽  
Tadao Yoshida ◽  
Michihiko Sone ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Subarachnoid Space ◽  
Area Under The Curve ◽  
Rank Correlation ◽  
Predictive Performance ◽  
Roc Curves ◽  
Imaging Findings ◽  
Spearman’S Rank Correlation ◽  
Sagittal Sinus ◽  
Magnetic Resonance Cisternography

Abstract Purpose To identify magnetic resonance cisternography (MRC) imaging findings related to Gadolinium-based contrast agent (GBCA) leakage into the subarachnoid space. Materials and methods The number of voxels of GBCA leakage (V-leak) on 3D-real inversion recovery images was measured in 56 patients scanned 4 h post-intravenous GBCA injection. Bridging veins (BVs) were identified on MRC. The numbers of BVs with surrounding cystic structures (BV-cyst), with arachnoid granulations protruding into the superior sagittal sinus (BV-AG-SSS) and the skull (BV-AG-skull), and including any of these factors (BV-incl) were recorded. Correlations between these variables and V-leak were examined based on the Spearman’s rank correlation coefficient. Receiver-operating characteristic (ROC) curves were generated to investigate the predictive performance of GBCA leakage. Results V-leak and the number of BV-incl were strongly correlated (r = 0.609, p < 0.0001). The numbers of BV-cyst and BV-AG-skull had weaker correlations with V-leak (r = 0.364, p = 0.006; r = 0.311, p = 0.020, respectively). The number of BV-AG-SSS was not correlated with V-leak. The ROC curve for contrast leakage exceeding 1000 voxels and the number of BV-incl had moderate accuracy, with an area under the curve of 0.871. Conclusion The number of BV-incl may be a predictor of GBCA leakage and a biomarker for waste drainage function without using GBCA.

Factors affecting progression to permanent atrial fibrillation in an unselected population of patients with non-permanent form of atrial fibrillation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
V.L Malavasi ◽  
E Fantecchi ◽  
V Tordoni ◽  
L Melara ◽  
A Barbieri ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cox Regression ◽  
Area Under The Curve ◽  
Roc Curves ◽  
Factors Affecting ◽  
Cox Proportional Hazard ◽  
Significant Difference ◽  
History Of ◽  
Unselected Population ◽  
Cox Proportional Hazard Regression

Abstract Background Natural history of atrial fibrillation (AF) shows a progression of arrhythmia from non-permanent to permanent AF. Permanent AF was found associated with a worse prognosis than non-permanent one. Aim To assess the factors associated with progression to permanent AF in an unselected population of AF patients with non-permanent AF. Methods In this prospective study we enrolled in- as well as out-patients with non-permanent AF and age ≥18 years, with at least one episode of ECG-documented AF within 1 year. The patients were followed-up at 1 month and every 6 months thereafter. Results Out of 523 patients, 314 (60%) were in non-permanent AF (80 [25.5%] paroxysmal AF, 165 [52.5%] persistent AF, 69 [2%] first diagnosed AF), mostly male (188, 59.9%), median age 71 years (IQ range 62–77), median CHA2DS2VASc 3 (1–4), median HATCH score 1 (1–2). After a median follow-up of 701 (IQ range 437–902) days, 66 patients (21%) showed permanent AF. CHA2DS2VASc and HATCH scores were incrementally associated to progression to permanent AF (CHA2DS2VASc χ2 p=0.001; HATCH χ2 p=0.017; p for trend CHA2DS2VASc &lt;0.001, HATCH p=0.001). At multivariable Cox proportional hazard regression the following variables were significantly associated with AF progression: age (hazard ratio [HR] 1.041; 95% CI: 1.004–1.079; p=0.028), at least moderate left atrial (LA) enlargement (&gt;42 ml/m2) (HR 2.092; 95% CI: 1.132–3.866; p=0.018), antiarrhythmics drugs after the enrollment (HR 0.087; 95% CI: 0.011–0.662; p=0.018), EHRA score &gt;2 (HR 0.351; 95% CI: 0.158–0.779; p=0.010) and Valvular HD (HR 2.161; 95% CI: 1.057–4.420; p=0.035). Adding LA dilation to HATCH score (HATCH-LA) and assigning 2 points based on multivariable Cox regression, HATCH-LA was statistically better in ROC curves in prediction of AF progression vs HATCH score (area under the curve 0.695 vs 0.636; DeLong p=0.0225). Survival-free curves on freedom from permanent AF using as discriminator HATCH-LA score ≤2 vs &gt;2 led to a statistically significant difference (χ2=16.080 p&lt;0.001), but the same was not found for HATCH score (χ2 =3.099; p=0.078). Conclusions In patients without permanent AF, progression of AF was independentely related to age, LA dilation, AF symptoms severity, antiarrhythmic drugs and Valvular HD. HATCH score predicted AF progression and adding to it LA dilation (at least moderate) improved patients stratification for the risk of evolution to permanent AF. Funding Acknowledgement Type of funding source: None

scholarly journals N6-Methyladenosine RNA modification in cerebrospinal fluid as a novel potential diagnostic biomarker for progressive multiple sclerosis

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Fei Ye ◽  
Tianzhu Wang ◽  
Xiaoxin Wu ◽  
Jie Liang ◽  
Jiaoxing Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Sclerosis ◽  
Clustering Analysis ◽  
Roc Curves ◽  
Progressive Multiple Sclerosis ◽  
Rna Modification ◽  
Diagnostic Model ◽  
Consensus Clustering ◽  
Rna Methylation ◽  
M6a Rna Methylation

Abstract Background Progressive multiple sclerosis (PMS) is an uncommon and severe subtype of MS that worsens gradually and leads to irreversible disabilities in young adults. Currently, there are no applicable or reliable biomarkers to distinguish PMS from relapsing–remitting multiple sclerosis (RRMS). Previous studies have demonstrated that dysfunction of N6-methyladenosine (m6A) RNA modification is relevant to many neurological disorders. Thus, the aim of this study was to explore the diagnostic biomarkers for PMS based on m6A regulatory genes in the cerebrospinal fluid (CSF). Methods Gene expression matrices were downloaded from the ArrayExpress database. Then, we identified differentially expressed m6A regulatory genes between MS and non-MS patients. MS clusters were identified by consensus clustering analysis. Next, we analyzed the correlation between clusters and clinical characteristics. The random forest (RF) algorithm was applied to select key m6A-related genes. The support vector machine (SVM) was then used to construct a diagnostic gene signature. Receiver operating characteristic (ROC) curves were plotted to evaluate the accuracy of the diagnostic model. In addition, CSF samples from MS and non-MS patients were collected and used for external validation, as evaluated by an m6A RNA Methylation Quantification Kit and by real-time quantitative polymerase chain reaction. Results The 13 central m6A RNA methylation regulators were all upregulated in MS patients when compared with non-MS patients. Consensus clustering analysis identified two clusters, both of which were significantly associated with MS subtypes. Next, we divided 61 MS patients into a training set (n = 41) and a test set (n = 20). The RF algorithm identified eight feature genes, and the SVM method was successfully applied to construct a diagnostic model. ROC curves revealed good performance. Finally, the analysis of 11 CSF samples demonstrated that RRMS samples exhibited significantly higher levels of m6A RNA methylation and higher gene expression levels of m6A-related genes than PMS samples. Conclusions The dynamic modification of m6A RNA methylation is involved in the progression of MS and could potentially represent a novel CSF biomarker for diagnosing MS and distinguishing PMS from RRMS in the early stages of the disease.

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