Analysis of vitamin D metabolic markers by mass spectrometry: Current techniques, limitations of the “gold standard” method, and anticipated future directions

2013 ◽  
Vol 34 (1) ◽  
pp. 2-23 ◽  
Author(s):  
Dietrich A. Volmer ◽  
Luana R.B.C. Mendes ◽  
Caroline S. Stokes
Keyword(s):  
Mass Spectrometry ◽  
Vitamin D ◽  
Standard Method ◽  
Gold Standard ◽  
Future Directions ◽  
Metabolic Markers ◽  
Gold Standard Method

scholarly journals Rapid Diagnosis of Malaria by Antigen Detection

2009 ◽  
Vol 3 (1) ◽  
pp. 14-16
Author(s):  
Mesbah Uddin Ahmed ◽  
Md Akram Hossain ◽  
AKM Shamsuzzaman ◽  
Md Murshed Alam ◽  
Abdul Hossain Khan ◽  
...  
Keyword(s):  
Thin Films ◽  
Sensitivity And Specificity ◽  
Standard Method ◽  
Gold Standard ◽  
Rapid Diagnosis ◽  
Healthy Controls ◽  
Immunochromatographic Test ◽  
Gold Standard Method ◽  
Malaria Antigen ◽  
Age And Sex

The study was conducted to evaluate the sensitivity and specificity of Immunochromatographic test (ICT) for antigen, using microscopy as the "gold standard" method for diagnosis of malaria. A total of 98 clinically suspected malaria patients and another 30 age and sex-matched healthy controls were included in this study. Thick and thin films were also prepared and examined under microscope as well as Immunochromatographic test (ICT) was performed for malaria antigen. Sensitivity and specificity of ICT for antigen were 93.22% and 94.87% respectively. Keywords: Detection of malaria antigen, Immunochromatographic test   doi: 10.3329/bjmm.v3i1.2965 Bangladesh J Med Microbiol 2009; 03 (01): 14-16

scholarly journals Evaluation of distilled water as buffered water replacement during 3% Giemsa’s solution preparation in Malaria diagnosis

2019 ◽  
Vol 10 (SPL1) ◽  
Author(s):  
Lai Yan Xia ◽  
Hamidah Abu Bakar
Keyword(s):  
Standard Method ◽  
Gold Standard ◽  
Malaria Diagnosis ◽  
Cost Effective ◽  
Peripheral Blood Smear ◽  
Blood Film ◽  
Distilled Water ◽  
Malaria Parasites ◽  
Gold Standard Method ◽  
Modified Method

Malaria is a life-threatening disease which has claimed many lives. Giemsa's stain is the gold standard method in malaria diagnosis. Generally, Giemsa's stain is diluted with buffered water. However, sometimes, it produces poor staining of the blood smears, in which can create a major challenge in detecting and identifying positive malaria parasites in a peripheral blood smear. This can lead to misdiagnosis and mistreatment to a patient. The present study examined the effect of replacing the buffered water to distilled water during the preparation of 3% Giemsa's solution. Blood specimens were collected from selected positive (n=80) and negative (n=300) malaria cases in EDTA tube. The modified method employed distilled water and different concentrations of buffered water for diluting Giemsa’s solution stock. The microscopy observation was performed on each set of blood film stained by both modified and standard Giemsa staining methods by two WHO’s qualified technicians. All Giemsa solutions with different diluents were comparable in detecting malaria parasites in the blood films. There was no difference between distilled water and different concentrations of buffered water. Furthermore, distilled water produced homogeneous staining and clearer background of the blood films, which enables different species of malaria to be identified. The present study demonstrates that the modified staining using distilled water in malaria parasites identification is comparable to the gold standard method. In addition, the modified method is rapid, easily available, cost-effective, and reliable.

Can we substitute brush cytology for biopsy in the evaluation of cervical lesions under the guidance of colposcopy?

2005 ◽  
Vol 15 (3) ◽  
pp. 489-492
Author(s):  
Z. Eftekhar ◽  
N. Izadi-Mood ◽  
F. Yarandi ◽  
M. Khodamoradi ◽  
P. Rahimi-Moghaddam
Keyword(s):  
Cervical Cancer ◽  
Cancer Screening ◽  
Cervical Cancer Screening ◽  
Standard Method ◽  
Uterine Cervix ◽  
Gold Standard ◽  
Brush Cytology ◽  
Cervical Lesions ◽  
Gold Standard Method ◽  
Special Expertise

In cervical cancer screening, colposcopically directed biopsy is the gold standard method for identifying intraepithelial and occult invasive lesions of the uterine cervix. As biopsy needs special expertise and the procedure is not convenient for the patients, we sought to evaluate colposcopically directed brush cytology as a substitute for biopsy of cervical lesions. We studied a series of 150 women who were referred for colposcopic evaluation. Colposcopically directed brush cytology and biopsy were performed for all patients with abnormal colposcopic findings. A total of 40 samples were excluded due to unsatisfactory report of brush cytology. Of the remaining 110 samples, 34 abnormal pathologies were reported in biopsy evaluations, while only 9 abnormal cytologies were reported in brush cytology specimens. Brush cytology sensitivity and specificity were 26% and 97%, respectively. We conclude that colposcopically directed brush cytology is not a safe substitute for biopsy in the evaluation of cervical lesions.

Diagnostic possibilities of methods for the evaluation of liver fibrosis in chronic viral hepatitis

2016 ◽  
Vol 88 (11) ◽  
pp. 149-155
Author(s):  
A N Navrotsky
Keyword(s):  
Liver Fibrosis ◽  
Viral Hepatitis ◽  
Histological Examination ◽  
Standard Method ◽  
Gold Standard ◽  
Transient Elastography ◽  
Chronic Viral Hepatitis ◽  
Point Of View ◽  
Severe Liver ◽  
Gold Standard Method

The paper reviews the diagnostic possibilities of different methods for the evaluation of liver fibrosis in chronic viral hepatitis from the point of view of their clinical application. Histological examination retains its value as the gold standard method in evaluating the liver. Transient elastography is a rather effective tool for identifying severe liver fibrosis.

A comparison of microsatellite instability analysis methods in colorectal cancer.

2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 46-46
Author(s):  
Samantha Lewis ◽  
Shaun Peterson ◽  
Kathryn Oostdik ◽  
Heather Tomlinson
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Instability ◽  
Standard Method ◽  
Gold Standard ◽  
Curve Analysis ◽  
Patient Treatment ◽  
Human Colorectal Cancer ◽  
Fragment Analysis ◽  
Gold Standard Method ◽  
Melt Curve Analysis

46 Background: Use of biomarkers for patient treatment stratification is an increasingly important topic with the recent FDA approval of Pembrolizumab and Nivolumab for microsatellite instability (MSI) high/mismatch repair (MMR) deficient cancers. This ground-breaking approval allows physicians to make patient treatment decisions based on molecular biomarker status. Thus, performance of detection methods for these biomarkers is of great importance. The gold standard for MSI analysis in a research setting is PCR followed by fragment analysis to resolve DNA size. Recently, PCR followed by melt curve analysis has been presented as an alternative approach. In this set of experiments these two methods are compared using a subset of human colorectal cancer samples. Methods: A cohort of matched human colorectal cancer and adjacent normal FFPE samples were used for this comparison. Eight pairs were selected that contained subtle shifts, low tumor volume or heterozygosity at microsatellite loci. These samples were then tested for MSI by fragment or melt curve analysis. Samples were then classified as MSI-H, MSI-L or microsatellite stable (MSS) according to manufacturer specifications for melt curve analysis or by an interpretive software for fragment analysis. Results: 40 mononucleotide markers were examined for each method. Melt curve analysis was concordant with fragment analysis in 70% of markers tested (28/40). Of discordant markers, 92% (11/12) were identified as unstable with fragment analysis but were stable by melt curve analysis. Additionally, two of the samples identified as MSI-H by fragment analysis were called MSS or MSI-L using the melt curve analysis method. These preliminary results suggest there may be differences in sensitivity when using challenging samples with melt curve compared to the gold standard method, fragment analysis. Conclusions: The standard method for determining MSI status utilizes PCR and fragment analysis. Recently, melt curve analysis has been proposed as an alternative method. We present preliminary findings of decreased sensitivity with melt curve compared to fragment analysis. Additional studies with a larger, more diverse sample set will be required to define this relationship further.

scholarly journals Estimation of Estradiol in Mouse Serum Samples: Evaluation of Commercial Estradiol Immunoassays

Endocrinology ◽  
2011 ◽  
Vol 152 (11) ◽  
pp. 4443-4447 ◽  
Author(s):  
Daniel J. Haisenleder ◽  
Aleisha H. Schoenfelder ◽  
Elizabeth S. Marcinko ◽  
Lisa M. Geddis ◽  
John C. Marshall
Keyword(s):  
Enzyme Immunoassay ◽  
Standard Method ◽  
Gold Standard ◽  
Correlation Study ◽  
Sample Volume ◽  
Mouse Serum ◽  
Serum Samples ◽  
Gold Standard Method ◽  
Standard Curve ◽  
Minimal Sample

The University of Virginia Center for Research in Reproduction Ligand Core performed an evaluation of nine commercial estradiol (E2) immunoassays for use with mouse serum. The evaluation had two components. 1) Recovery Studies: a mouse pool was spiked with E2 concentrations across the assay range, and percent recovery and parallelism to the assay standard curve were determined. 2) Correlation Studies: serum pools were collected from intact females, ovariectomized (OVX) and OVX-E2 treated mice and E2 assayed, then measured by gas chromatography/tandem mass spectrometry (GC/MSMS) for comparison to a gold standard method. Recovery results showed that E2 recovery from spiked mouse pools varied greatly (from <18% to >640%) among kits tested. However, three kits (DiaSorin Radioimmunoassay, Siemens Double Antibody RIA, and CalBiotech Enzyme Immunoassay) showed reasonable recoveries and parallelism. Data collected from the Correlation Study showed that values from intact, OVX and OVX-E2-treated mouse pools varied by several fold vs. GC/MSMS for most of the kits tested. The DiaSorin RIA and CalBiotech Enzyme Immunoassay Kits showed the best correlation to GC/MSMS. Unfortunately, while this evaluation was ongoing, the DiaSorin Kit was discontinued. In summary, the CalBiotech Kit was the only available assay tested that demonstrated good E2 parallelism to the assay standard curve and accuracy vs. a gold standard method (i.e. GC/MSMS). Also of note, the CalBiotech assay is sensitive and requires minimal sample volume. Therefore, based on these findings the CalBiotech E2 assay has been implemented for use in mouse serum samples within the Ligand Core.

scholarly journals An open-source synesthesia consistency test for use on the Qualtrics platform.

2021 ◽  
Author(s):  
Nicholas Root
Keyword(s):  
Open Source ◽  
Standard Method ◽  
Gold Standard ◽  
Sensory Input ◽  
Healthy Individuals ◽  
Consistency Test ◽  
Gold Standard Method ◽  
Open Source Tool ◽  
The World ◽  
Tone Color

Synesthesia is a neurological phenomenon in which healthy individuals experience additional, automatic, and consistent perceptions unrelated to veridical sensory input. For most of the most common forms of synesthesia, the additional sensation is a color: grapheme-color synesthetes experience specific letters of the alphabet as having specific colors, tone-color synesthetes experience specific sounds as having specific colors, etc. The “gold standard” method to diagnose X-to-color synesthesia is to measure test-retest consistency: synesthetes use a colorpicker to choose the color they experience for a particular stimulus, and then are retested minutes, months, or even years later; genuine synesthetes experience highly consistent associations across time. There is not currently an open source tool to collect color associations from synesthetes. In addition to presenting a technical barrier for entry into synesthesia research, the lack of an open source standard has also led to a proliferation of (slightly) different choices in methodology from lab to lab. In the present work, I use colorpicker experiements in synesthetes and controls to demonstrate that even small methodological details in test-retest experiments can profoundly influence the resulting data. I use this data to generate an online color picker with ideal experimental properties. The colorpicker is open source (available on a Github respository) and can be implemented by anyone with an account on the Qualtrics platform, one of the most common online experimental platforms in the world.

scholarly journals Current Diagnostic Methods for Assessing Transfer of Passive Immunity in Calves and Possible Improvements: A Literature Review

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2963
Author(s):  
Rayanne Soalheiro Souza ◽  
Lucas Braga Costa Santos ◽  
Isabela Oliveira Melo ◽  
Daiane Maria Cerqueira ◽  
Juliana Vieira Dumas ◽  
...  
Keyword(s):  
Literature Review ◽  
Standard Method ◽  
Immunoglobulin G ◽  
Gold Standard ◽  
Diagnostic Methods ◽  
Radial Immunodiffusion ◽  
Passive Immunity ◽  
Indirect Methods ◽  
Gold Standard Method ◽  
Methods Of Evaluation

Several direct or indirect methods can be used to assess immunoglobulin G (IgG) concentrations in calves, which evaluates the transfer of passive immunity (TPI). Radial immunodiffusion (RID) is the gold standard method to measure serum IgG in bovines. Previous studies have shown that colostrum provides several molecules in addition to immunoglobulins, which play an important role in the passive immunity of the calf. However, no studies have yet determined the level of interference of these components in the immunity, health and survival of calves. In this sense, the objective of this study is to review the methods of evaluation available for the laboratory and field diagnosis of TPI in calves and discuss the main aspects of each technique. Several methods available for TPI evaluation in calves may provide insights into the various components of colostrum involved in passive immunity.

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