scholarly journals Comparison of Different Double Immunostaining Protocols for Paraffin Embedded Liver Tissue

1999 ◽  
Vol 18 (4) ◽  
pp. 227-233 ◽  
Author(s):  
Alexander Schütz ◽  
Andrea Tannapfel ◽  
Christian Wittekind
Keyword(s):  
Alkaline Phosphatase ◽  
Liver Tissue ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Time Cost ◽  
Double Immunostaining ◽  
Intracellular Protein ◽  
Background Staining ◽  
Fresh Frozen ◽  
Sensitivity Specificity

Most of the double immunostaining protocols that have been introduced so far have been developed for application on fresh frozen material or based on different species antibodies. In liver tissue, general problems of double immunostaining techniques are further complicated by tissue‐specific difficulties, such as necrosis or high intracellular protein content. To assess a reliable double immunostaining protocol for archived, paraffin embedded liver tissue, different protocols based on the use of same species primary antibodies were evaluated in terms of sensitivity, specificity and non‐specific background staining in pathological liver specimens. We compared peroxidase–anti‐peroxidase, alkaline phosphatase–anti‐alkaline phosphatase (PAP/APAP), labelled‐avidin–biotin (LAB/LAB) and digoxigenin–anti‐digoxigenin (dig–a‐dig/PAP) techniques using different cytokeratin antibodies and an antibody against PCNA. Comparison of the double immunostaining techniques revealed a high sensitivity and specificity in all procedures. Sections, which were stained employing PAP/APAP‐technique, displayed a higher background staining compared to sections which were treated with the LAB/LAB or dig–a‐dig/PAP protocol. In contrast to the dig–a‐dig/PAP protocol, the LAB/LAB technique provides a better time/cost relationship. Therefore, we would like to recommend a modified LAB/LAB protocol for simultaneous detection of different antigens in archived liver tissue.

scholarly journals Bioprocessing and integration of a high flux screening systematic platform based on isothermal amplification for the detection on 8 common pathogens

2020 ◽  
Author(s):  
Huamin Zhong ◽  
Hongwei Deng ◽  
Ming Li ◽  
Huahong Zhong
Keyword(s):  
Simultaneous Detection ◽  
High Sensitivity ◽  
Isothermal Amplification ◽  
High Flux ◽  
Double Blind ◽  
Screening Platform ◽  
Unique Specificity ◽  
Species Specific ◽  
Sensitivity Specificity ◽  
Human Infections

Abstract During a large variety of common pathogens, E. coli, P. aeruginosa, MRSA, MRCNS, V. parahaemolyticus, L. monocytogenes and Salmonella are the leading pathogens responsible for large number of human infections and diseases. In this study, a high flux screening based on nucleic acid isothermal amplification technique has been developed. For the 8 common pathogens, species-specific targets had been selected and analyzed for their unique specificity. After optimization, separate LAMP reaction assays had been bioprocessed and integrated into one systematic detection platform, including 8 strips (PCR tubes) and 96-well plates. Eight standard strains verified for the accuracy. Application of the established high flux screening platform was used for detection for 48 samples in 4 different 96-well plates, with 2 groups of 2 operators using double-blind procedure. The accuracy of 100% was obtained, with the total time consumption as 66–75 min (for 12 samples detection on 8 different pathogens). As concluded, through the bioprocess of the systematic platform based on LAMP technique, it’s been demonstrated to be capable of simultaneous detection of 8 pathogens, with high sensitivity, specificity, rapidity and convenience.

"Sandwich" enzyme immunoassay for placental alkaline phosphatase.

1981 ◽  
Vol 27 (12) ◽  
pp. 2014-2018 ◽  
Author(s):  
J L Millán ◽  
T Stigbrand
Keyword(s):  
Alkaline Phosphatase ◽  
Rheumatoid Factor ◽  
Cancer Patients ◽  
High Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Placental Alkaline Phosphatase ◽  
Upper Limit ◽  
Highly Sensitive ◽  
Sensitivity Specificity ◽  
Sandwich Enzyme Immunoassay

Abstract Alkaline phosphatase of the placental type in serum has been suggested as a "marker" for malignancy and pregnancy. We describe a highly sensitive enzyme-linked immunosorbent assay (ELISA) for the measurement of this enzyme in serum and ascitic fluid. The assay will detect as little as 0.4 microgram/L, significantly less than with a radioimmunoassay performed with the same reagents. It is highly specific; it does not measure even above-normal concentrations of the intestinal and liver isoenzymes of alkaline phosphatase. The assay is technically simple and allows the processing of many samples in less than 10 h. We measured this isoenzyme in serum of an adult control population. The upper limit of normality is 1.85 microgram/L. Interference by rheumatoid factor was eliminated. Concentrations of the analyte were increased in all pregnancy sera tested. Concentration and activity as measured by two different catalytic assays correlated well. Samples from cancer patients also showed a good correlation, with some exceptions. Possible reasons for these exceptions are discussed. The high sensitivity, specificity, and simplicity of this assay should make it a useful adjunct in monitoring cancer and pregnancy.

TO SEPARATELY ASSESS THE DIAGNOSTIC POTENTIAL OF TVS & MRI IN THE TERMS OF SENSITIVITY AND SPECIFICITY BY CORRELATING THE IMAGING FINDINGS WITH HISTOPATHOLOGY

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Suraj Mathur
Keyword(s):  
Transvaginal Ultrasound ◽  
High Sensitivity ◽  
Imaging Evaluation ◽  
Medical College ◽  
Conventional Mri ◽  
Diagnostic Potential ◽  
Adc Mapping ◽  
Malignant Lesions ◽  
Sensitivity Specificity

This prospective study was done in the Department of Radio diagnosis Govt. Medical College, Kozhikode. A total of 65 patients who were referred to our department with clinical suspicion of endometrial lesions and incidentally detected endometrial lesions on ultrasonography underwent transvaginal ultrasound and subsequent Imaging evaluation of pelvis MRI has very high sensitivity (95%) and specificity (98%) and is almost as accurate (97%) as histopathology in differentiating benign from malignant lesions. Addition of DWI with ADC mapping to conventional MRI increases its accuracy even more. However there is inherent limitation to MRI in detecting carcinoma in situ and micrometastasis. Keywords: TVS, MRI, Sensitivity, Specificity, Histopathology.

scholarly journals Use of β-D-glucan in diagnosis of suspected Pneumocystis jirovecii pneumonia in adults with HIV infection

2021 ◽  
pp. 095646242110222
Author(s):  
Thomas Juniper ◽  
Chris P Eades ◽  
Eliza Gil ◽  
Harriet Fodder ◽  
Killian Quinn ◽  
...  
Keyword(s):  
Predictive Value ◽  
Diagnostic Tests ◽  
Elevated Serum ◽  
Clinical Information ◽  
High Sensitivity ◽  
Pneumocystis Pneumonia ◽  
Pneumocystis Jirovecii Pneumonia ◽  
Alternative Diagnosis ◽  
Positive Threshold ◽  
Sensitivity Specificity

Objectives: An elevated serum (1-3)-β-D-glucan (BDG) concentration has high sensitivity for a diagnosis of Pneumocystis pneumonia (PCP) in people with HIV (PWH). At the current manufacturer-recommended positive threshold of 80 pg/mL (Fungitell), specificity for PCP is variable and other diagnostic tests are required. We evaluated the utility of serum BDG for diagnosis of suspected PCP in PWH at three inner-London hospitals to determine BDG concentrations for diagnosis and exclusion of PCP. Methods: From clinical case records, we abstracted demographic and clinical information and categorised patients as having confirmed or probable PCP, or an alternative diagnosis. We calculated sensitivity, specificity and positive predictive value (PPV) of serum BDG concentrations >400 pg/mL and negative predictive value (NPV) of BDG <80 pg/mL. Results: 76 patients were included; 29 had laboratory-confirmed PCP, 17 had probable PCP and 30 had an alternative diagnosis. Serum BDG >400 pg/mL had a sensitivity of 83%, specificity of 97% and PPV 97% for diagnosis of PCP; BDG <80 pg/mL had 100% NPV for exclusion of PCP. Conclusions: In PWH with suspected PCP, BDG <80 pg/mL excludes a diagnosis of PCP, whereas BDG concentrations >400 pg/mL effectively confirm the diagnosis. Values 80–400 pg/mL should prompt additional diagnostic tests.

scholarly journals The Child Behavior Checklist as a Screening Instrument for PTSD in Refugee Children

Children ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 521
Author(s):  
Ina Nehring ◽  
Heribert Sattel ◽  
Maesa Al-Hallak ◽  
Martin Sack ◽  
Peter Henningsen ◽  
...  
Keyword(s):  
Child Behavior ◽  
Child Behavior Checklist ◽  
High Sensitivity ◽  
Roc Curves ◽  
Structured Interview ◽  
Screening Instrument ◽  
Screening Tools ◽  
Refugee Children ◽  
Post Traumatic Stress ◽  
Sensitivity Specificity

Thousands of refugees who have entered Europe experienced threatening conditions, potentially leading to post traumatic stress disorder (PTSD), which has to be detected and treated early to avoid chronic manifestation, especially in children. We aimed to evaluate and test suitable screening tools to detect PTSD in children. Syrian refugee children aged 4–14 years were examined using the PTSD-semi-structured interview, the Kinder-DIPS, and the Child Behavior Checklist (CBCL). The latter was evaluated as a potential screening tool for PTSD using (i) the CBCL-PTSD subscale and (ii) an alternative subscale consisting of a psychometrically guided selection of items with an appropriate correlation to PTSD and a sufficient prevalence (presence in more than 20% of the cases with PTSD). For both tools we calculated sensitivity, specificity, and a receiver operating characteristic (ROC) curve. Depending on the sum score of the items, the 20-item CBCL-PTSD subscale as used in previous studies yielded a maximal sensitivity of 85% and specificity of 76%. The psychometrically guided item selection resulted in a sensitivity of 85% and a specificity of 83%. The areas under the ROC curves were the same for both tools (0.9). Both subscales may be suitable as screening instrument for PTSD in refugee children, as they reveal a high sensitivity and specificity.

scholarly journals Evaluation of HiCrome KPC Agar for the Screening of Carbapenem-Resistant Enterobacterales Colonization in the ICU Setting of a Tertiary Care Hospital

2021 ◽  
Author(s):  
Ashoka Mahapatra ◽  
K Nikitha ◽  
Sutapa Rath ◽  
Bijayini Behera ◽  
Kavita Gupta
Keyword(s):  
Tertiary Care ◽  
High Sensitivity ◽  
Care Hospital ◽  
Predictive Values ◽  
Klebsiella Pneumoniae Carbapenemase ◽  
Carbapenem Resistant ◽  
Rectal Swabs ◽  
Control And Prevention ◽  
Indian Setting ◽  
Sensitivity Specificity

Abstract Background Spread of carbapenem-resistant Enterobacterales (CRE) is a significant concern in intensive care unit (ICU) settings. Approaches to routine screening for CRE colonization in all ICU patients vary depending on institutional epidemiology and resources. The present study was aimed to evaluate the performance of HiCrome Klebsiella pneumoniae carbapenemase (KPC) agar for the detection of CRE colonization in ICU settings taking the Centers for Disease Control and Prevention (CDC) recommended method as reference. Methods Two-hundred and eighty rectal swabs (duplicate) from 140 patients were subjected to CRE detection in HiCrome KPC agar and MacConkey agar (CDC criteria). Results Using CDC method, total 41 CRE isolates were recovered comprising of 29 E scherichia coli, 11 Klebsiella, and 1 Enterobacter spp. On the other hand, 49 isolates of CRE recovered from 140 rectal swabs using HiCrome KPC agar, out of which 33 were E. coli, 15 Klebsiella, and 1 Enterobacter sp. Statistical Analysis Sensitivity, specificity, negative, and positive predictive values of CRE screening by HiCrome KPC agar were found to be 100% (91.4–100), 91.9% (84.8–95.8), 83.6% (70.9–91.4), and 100% (95.9–100), respectively, taking the CDC recommended method as reference. Conclusion HiCrome KPC agar has high sensitivity in screening CRE colonization. Further studies are needed to establish its applicability for detecting the predominant circulating carbapenemases in the Indian setting.

scholarly journals Confirming putative variants at ≤ 5% allele frequency using allele enrichment and Sanger sequencing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yan Helen Yan ◽  
Sherry X. Chen ◽  
Lauren Y. Cheng ◽  
Alyssa Y. Rodriguez ◽  
Rui Tang ◽  
...  
Keyword(s):  
Sanger Sequencing ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Sequencing Errors ◽  
Whole Exome ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Fresh Frozen ◽  
The Cost ◽  
Allelic Fraction

AbstractWhole exome sequencing (WES) is used to identify mutations in a patient’s tumor DNA that are predictive of tumor behavior, including the likelihood of response or resistance to cancer therapy. WES has a mutation limit of detection (LoD) at variant allele frequencies (VAF) of 5%. Putative mutations called at ≤ 5% VAF are frequently due to sequencing errors, therefore reporting these subclonal mutations incurs risk of significant false positives. Here we performed ~ 1000 × WES on fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tissue biopsy samples from a non-small cell lung cancer patient, and identified 226 putative mutations at between 0.5 and 5% VAF. Each variant was then tested using NuProbe NGSure, to confirm the original WES calls. NGSure utilizes Blocker Displacement Amplification to first enrich the allelic fraction of the mutation and then uses Sanger sequencing to determine mutation identity. Results showed that 52% of the 226 (117) putative variants were disconfirmed, among which 2% (5) putative variants were found to be misidentified in WES. In the 66 cancer-related variants, the disconfirmed rate was 82% (54/66). This data demonstrates Blocker Displacement Amplification allelic enrichment coupled with Sanger sequencing can be used to confirm putative mutations ≤ 5% VAF. By implementing this method, next-generation sequencing can reliably report low-level variants at a high sensitivity, without the cost of high sequencing depth.

scholarly journals Microfluidics-Based Plasmonic Biosensing System Based on Patterned Plasmonic Nanostructure Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 826
Author(s):  
Yanting Liu ◽  
Xuming Zhang
Keyword(s):  
Plasmon Resonance ◽  
Point Of Care ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Microfluidic Chips ◽  
Label Free ◽  
Plasmonic Nanostructure ◽  
Point Of Care Diagnostics ◽  
Surface Enhanced Raman ◽  
Nanostructure Arrays

This review aims to summarize the recent advances and progress of plasmonic biosensors based on patterned plasmonic nanostructure arrays that are integrated with microfluidic chips for various biomedical detection applications. The plasmonic biosensors have made rapid progress in miniaturization sensors with greatly enhanced performance through the continuous advances in plasmon resonance techniques such as surface plasmon resonance (SPR) and localized SPR (LSPR)-based refractive index sensing, SPR imaging (SPRi), and surface-enhanced Raman scattering (SERS). Meanwhile, microfluidic integration promotes multiplexing opportunities for the plasmonic biosensors in the simultaneous detection of multiple analytes. Particularly, different types of microfluidic-integrated plasmonic biosensor systems based on versatile patterned plasmonic nanostructured arrays were reviewed comprehensively, including their methods and relevant typical works. The microfluidics-based plasmonic biosensors provide a high-throughput platform for the biochemical molecular analysis with the advantages such as ultra-high sensitivity, label-free, and real time performance; thus, they continue to benefit the existing and emerging applications of biomedical studies, chemical analyses, and point-of-care diagnostics.

scholarly journals Sensitivity, specificity, and accuracy of a liquid biopsy approach utilizing molecular amplification pools

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jessica Garcia ◽  
Nick Kamps-Hughes ◽  
Florence Geiguer ◽  
Sébastien Couraud ◽  
Brice Sarver ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cancer Patients ◽  
Clinical Setting ◽  
High Sensitivity ◽  
Sequencing Error ◽  
Lung Cancer Patients ◽  
Mutation Discovery ◽  
Sensitivity Specificity ◽  
Next Generation Sequencing Ngs ◽  
Digital Polymerase Chain Reaction

AbstractCirculating cell-free DNA (cfDNA) has the potential to be a specific biomarker for the therapeutic management of lung cancer patients. Here, a new sequencing error-reduction method based on molecular amplification pools (MAPs) was utilized to analyze cfDNA in lung cancer patients. We determined the accuracy of MAPs plasma sequencing with respect to droplet digital polymerase chain reaction assays (ddPCR), and tested whether actionable mutation discovery is improved by next-generation sequencing (NGS) in a clinical setting. This study reports data from 356 lung cancer patients receiving plasma testing as part of routine clinical management. Sequencing of cfDNA via MAPs had a sensitivity of 98.5% and specificity 98.9%. The ddPCR assay was used as the reference, since it is an established, accurate assay that can be performed contemporaneously on the same plasma sample. MAPs sequencing detected somatic variants in 261 of 356 samples (73%). Non-actionable clonal hematopoiesis-associated variants were identified via sequencing in 21% of samples. The accuracy of this cfDNA sequencing approach was similar to that of ddPCR assays in a clinical setting, down to an allele frequency of 0.1%. Due to broader coverage and high sensitivity for insertions and deletions, sequencing via MAPs afforded important detection of additional actionable mutations.

Adaptation and Validation of the Mini-Addenbrooke’s Cognitive Examination in Dementia in Arabic Speakers in Egypt

2020 ◽  
Vol 49 (6) ◽  
pp. 611-616
Author(s):  
Tarik Qassem ◽  
Mohamed S. Khater ◽  
Tamer Emara ◽  
Doha Rasheedy ◽  
Heba M. Tawfik ◽  
...  
Keyword(s):  
Screening Tool ◽  
Characteristic Curve ◽  
High Sensitivity ◽  
Receiver Operator Characteristic Curve ◽  
Cutoff Score ◽  
Arabic Speakers ◽  
Dementia Patients ◽  
Significant Difference ◽  
Sensitivity Specificity ◽  
Addenbrooke’S Cognitive Examination

<b><i>Background:</i></b> The mini-Addenbrooke’s Cognitive Examination (m-ACE) is a brief cognitive battery that assesses 5 subdomains of cognition (attention, memory, verbal fluency, visuospatial abilities, and memory recall). It is scored out of 30 and can be administered in under 5 min providing a quick screening tool for assessment of cognition. <b><i>Objectives:</i></b> We aimed to adapt the m-ACE in Arabic speakers in Egypt and to validate it in dementia patients to provide cutoff scores. <b><i>Methods:</i></b> We included 37 patients with dementia (Alzheimer’s disease [<i>n</i> = 25], vascular dementia [<i>n</i> = 8], and dementia with Lewy body [<i>n</i> = 4]) and 43 controls. <b><i>Results:</i></b> There was a statistically significant difference (<i>p</i> &#x3c; 0.001) on the total m-ACE score between dementia patients (mean 10.54 and standard deviation [SD] 5.83) and controls (mean 24.02 and SD 2.75). There was also a statistically significant difference between dementia patients and controls on all sub-score domains of the m-ACE (<i>p</i> &#x3c; 0.05). Performance on the m-ACE significantly correlated with both the Mini-Mental State Examination (MMSE) and the Addenbrooke’s Cognitive Examination-III (ACE-III). Using a receiver operator characteristic curve, the optimal cutoff score for dementia on the m-ACE total score was found to be 18 (92% sensitivity, 95% specificity, and 94% accuracy). <b><i>Conclusions:</i></b> We adapted the m-ACE in Arabic speakers in Egypt and provided objective validation of it as a screening tool for dementia, with high sensitivity, specificity, and accuracy.

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