Liquid-chromatographic evaluation of age-related changes in the urinary excretion of free catecholamines in pediatric patients.

1984 ◽  
Vol 30 (2) ◽  
pp. 301-303 ◽  
Author(s):  
T G Rosano
Keyword(s):  
Urinary Excretion ◽  
Pediatric Patients ◽  
False Negative ◽  
Age Groups ◽  
Reference Intervals ◽  
Clinical Sensitivity ◽  
Negative Results ◽  
Age Related ◽  
False Negative Results ◽  
Liquid Chromatographic

Abstract Pediatric patients (to age 18) without neuroblastoma show an age-related decrease in urinary excretion of each of the catecholamines--epinephrine, norepinephrine, and dopamine--in relation to creatinine excretion. From these data, I have developed reference intervals for pediatric age groups. Application of these ranges to seven patients with neuroblastoma and ganglioneuroblastoma indicated a high clinical sensitivity for the urinary dopamine determination but significant false-negative results for epinephrine and norepinephrine.

scholarly journals Visualization of Lesions of Metaphyses and Epiphyses of Bones in Newborns and Young Children

2021 ◽  
pp. 82-90
Author(s):  
N. A. Sholokhova
Keyword(s):  
Young Children ◽  
False Negative ◽  
Age Groups ◽  
High Sensitivity ◽  
Negative Results ◽  
False Negative Results ◽  
Inflammatory Processes ◽  
Group 5 ◽  
Magnetic Resonance Imaging Mri ◽  
Diagnostic Capabilities

The aim of this study was to determine the diagnostic capabilities of various methods of radiological diagnostics for lesions of the metaphyses and epiphyses of bones in newborns and young children.The study involved 108 children in the age group 5 days – 12 months with pathological changes in the pineal gland and bone metaphysis. The possibilities and advantages of standard radiography (СR), ultrasound examination (US) and magnetic resonance imaging (MRI) in the early and differential diagnosis of the osteomyelitis process and epiphyseolysis have been determined. High sensitivity (98 %), specificity (99 %) and accuracy (98 %) for ultrasound and sensitivity (94 %), specificity (89 %) and accuracy (95 %) of MRI in diagnosing osteomyelitis in patients of this age groups. At the same time, the possibilities of standard radiography at the stages of early diagnosis of inflammatory processes in the distal parts of the bones were limited due to a number of factors. The use of diagnostic algorithms greatly facilitates the work of a radiologist and reduces the number of false negative results during the initial treatment of patients.

scholarly journals Clinical Performance of SARS-CoV-2 Molecular Testing

2020 ◽  
Author(s):  
Daniel A. Green ◽  
Jason Zucker ◽  
Lars F. Westblade ◽  
Susan Whittier ◽  
Hanna Rennert ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Severe Disease ◽  
False Negative ◽  
Molecular Testing ◽  
Repeat Testing ◽  
Clinical Sensitivity ◽  
Initial Testing ◽  
Molecular Assays ◽  
Negative Results ◽  
False Negative Results

AbstractMolecular testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the gold standard for diagnosis of coronavirus disease 2019 (COVID-19), but the test clinical performance is poorly understood. From 3/10/2020-5/1/2020 NewYork-Presbyterian laboratories performed 27,377 SARS-CoV-2 molecular assays from 22,338 patients. Repeat testing was performed in 3,432 patients, of which 2,413 had negative and 1,019 had positive first day results. Repeat-tested patients were more likely to be older, male, African-American or Hispanic, and to have severe disease. Among the patients with initially negative results, 18.6% became positive upon repeat-testing. Only 58.1% of any-time positive patients had a result of “detected” on the first test. The clinical sensitivity of COVID-19 molecular assays is estimated between 66.2 % and 95.6%, depending on the unknown number of false negative results in single-tested patients. Conversion to a negative result is unlikely to occur before 15 to 20 days after initial testing or 20-30 days after the onset of symptoms, with 50% conversion occurring at 28 days after initial testing. Forty-nine initially-positive patients converted to negative and then back to positive in subsequent days. Conversion from first day negative to positive results increased linearly with each day of testing, reaching 25% probability in 20 days. In summary, our study provides estimates of the clinical performance of SARS-CoV-2 molecular assays and suggests time frames for appropriate repeat testing, namely 15 to 20 days after a positive test and the same or next 2 days after a negative test in a patient with high suspicion for COVID-19.

Does a change in quality control results influence the sensitivity of an anti-HCV test?

2020 ◽  
Vol 58 (8) ◽  
pp. 1372-1380 ◽  
Author(s):  
Wayne J. Dimech ◽  
Giuseppe A. Vincini ◽  
Liza M. Cabuang ◽  
Megan Wieringa
Keyword(s):  
Quality Control ◽  
False Negative ◽  
External Quality Assessment Scheme ◽  
Clinical Sensitivity ◽  
Root Cause ◽  
Negative Results ◽  
False Negative Results ◽  
Three Samples ◽  
The Difference

AbstractBackgroundLaboratories use quality control (QC) testing to monitor the extent of normal variation. Assay lot number changes contribute the greatest amount of variation in infectious disease serology testing. An unexpected change in six lots of an anti-HCV assay allowed the determination of the effect these lot changes made to the assay’s clinical sensitivity.MethodsTwo sets of seroconversion samples comprising of 44 individual samples and 9 external quality assessment scheme (EQAS) samples, all positive to anti-HCV, were tested in affected and unaffected assay lots, and the difference in the quantitative and qualitative results of the samples was analyzed.ResultsOf 44 low-positive seroconversion samples tested in affected and unaffected assay lots, only three samples had results reported below the assay cutoff when tested on two of the six affected assay lot. A further sample had results below the cutoff for only one affected lot. None of the EQAS samples reported false-negative results. Samples having a signal to cutoff value of less than 6.0 generally had lower results in the affected lots compared with the unaffected lots.ConclusionsUnexpected changes in QC reactivity related to variation, in particular assay lot changes, may affect patient results. This study demonstrated that QConnect Limits facilitated the detection of an unexpectedly large variation in QC test results, allowed for the identification of the root cause of the change, and showed that the risk associated with the change was low but credible. The use of evidence-based QC program is essential to detect changes in test systems.

scholarly journals Ultrasound technologies in the diagnosis, treatment, and rehabilitation of children with testicular torsion

2021 ◽  
Vol 11 (3) ◽  
pp. 351-358
Author(s):  
Svetlana Yu. Komarova ◽  
Natalya A. Tsap ◽  
Il’ya A. Karachev
Keyword(s):  
Testicular Torsion ◽  
Inflammatory Diseases ◽  
False Negative ◽  
Disease Onset ◽  
Age Groups ◽  
Treatment Strategies ◽  
Negative Results ◽  
Left Testicle ◽  
False Negative Results ◽  
Disease Stages

AIM: This study improves the diagnosis of testicular inversion in children to select different treatment strategies by determining the effectiveness of conservative and surgical testicular detorsion criteria. MATERIALS AND METHODS: The clinical data from 2010 to 2020 included 110 children with testicular torsion. In 64% of cases, the left testicle predominated. Testicular torsion occurred in 50% of children in the 12- to 14-year-old age group. The time from disease onset to seeking medical help ranged from 1.5 hours to 11 days. It was less than 6 hours in 41.8% of children, from 6 to 12 hours in 13.6% of boys, 12 to 24 hours in 11% of patients, and more than 24 hours in 33.6% of boys and adolescents. The protocol for the diagnosis, treatment and rehabilitation of all children included various techniques for ultrasound examination of the scrotal organs. RESULTS: The analysis showed the absence of reliable criteria for detecting testicle torsion in the early periods (61%100%): spiral course of the spermatic vessels (63.9%), change in the position of the testicle (19.8%), increase in the volume of the testicle and appendage (98.3%), a change in testicle shape and the inability to withdraw its poles (47.5%), and a hydrocele (67.2%). The index of false-negative results of the ultrasound scan of the scrotal organs reaches 40%. Conservative navigation detorsion was performed in 39 (35.5%) boys and adolescents during the early disease stages. The ultrasound criteria for the effectiveness of conservative detorsion were established. The main criteria normalized blood flow in the testis (100%). Surgical treatment of testicular inversion was performed in 71 (64.5%) boys and adolescents. CONCLUSIONS: Compliance with the protocol for diagnosing, treating, and rehabilitating children in different age groups with testicular torsion allowed us to determine adequate emergency treatment strategies and follow-up. An ultrasound differential diagnosis is performed with testicular hydatid torsion and inflammatory diseases of the scrotal organs. The informativeness of the ultrasound methods amounted to 60%.

scholarly journals Target specific serologic analysis of COVID-19 convalescent plasma

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249938
Author(s):  
Sachie Ikegami ◽  
Robert C. Benirschke ◽  
Hossein Fakhrai-Rad ◽  
Mohammad H. Motamedi ◽  
Rick Hockett ◽  
...  
Keyword(s):  
False Negative ◽  
High Specificity ◽  
Clinical Samples ◽  
Disease Symptoms ◽  
Clinical Sensitivity ◽  
Negative Results ◽  
False Negative Results ◽  
Assay Performance ◽  
Roche Diagnostics ◽  
Donor Characteristics

This study compared the performance of four serology assays for Coronavirus Disease 2019 (COVID-19) and investigated whether COVID-19 disease history correlates with assay performance. Samples were tested at Northshore using the Elecsys Anti-SARS-CoV-2 (Roche Diagnostics), Access SARS-CoV-2 IgG anti-RBD (Beckman Coulter), and LIAISON SARS-CoV-2 S1/S2 IgG (DiaSorin) as well as at Genalyte using Maverick Multi-Antigen Serology Panel. The study included one hundred clinical samples collected before December 2019 and ninety-seven samples collected from convalescent plasma donors originally diagnosed with COVID-19 by PCR. COVID-19 disease history was self-reported by the plasma donors. There was no difference in specificity between the assays tested. Clinical sensitivity of these four tests was 98% (Genalyte), 96% (Roche), 92% (DiaSorin), and 87% (Beckman). The only statistically significant differences in clinical sensitivity was between the Beckman assay and both Genalyte and Roche assays. Convalescent plasma donor characteristics and disease symptoms did not correlate with false negative results from the Beckman and DiaSorin assays. All four tests showed high specificity (100%) and varying sensitivities (89–98%). No correlations between disease history and serology results were observed. The Genalyte Multiplex assay showed as good or better sensitivity to three other previously validated assays with FDA Emergency Use Authorizations.

scholarly journals Identification and assessment of markers of biotin status in healthy adults

2013 ◽  
Vol 110 (2) ◽  
pp. 321-329 ◽  
Author(s):  
Wei Kay Eng ◽  
David Giraud ◽  
Vicki L. Schlegel ◽  
Dong Wang ◽  
Bo Hyun Lee ◽  
...  
Keyword(s):  
Organic Acids ◽  
Urinary Excretion ◽  
False Negative ◽  
Holocarboxylase Synthetase ◽  
Biotin Deficiency ◽  
Treatment Groups ◽  
Negative Results ◽  
Expression Of Genes ◽  
False Negative Results ◽  
Feeding Protocol

Human biotin requirements are unknown and the identification of reliable markers of biotin status is necessary to fill this knowledge gap. Here, we used an outpatient feeding protocol to create states of biotin deficiency, sufficiency and supplementation in sixteen healthy men and women. A total of twenty possible markers of biotin status were assessed, including the abundance of biotinylated carboxylases in lymphocytes, the expression of genes from biotin metabolism and the urinary excretion of biotin and organic acids. Only the abundance of biotinylated 3-methylcrotonyl-CoA carboxylase (holo-MCC) and propionyl-CoA carboxylase (holo-PCC) allowed for distinguishing biotin-deficient and biotin-sufficient individuals. The urinary excretion of biotin reliably identified biotin-supplemented subjects, but did not distinguish between biotin-depleted and biotin-sufficient individuals. The urinary excretion of 3-hydroxyisovaleric acid detected some biotin-deficient subjects, but produced a meaningful number of false-negative results and did not distinguish between biotin-sufficient and biotin-supplemented individuals. None of the other organic acids that were tested were useful markers of biotin status. Likewise, the abundance of mRNA coding for biotin transporters, holocarboxylase synthetase and biotin-dependent carboxylases in lymphocytes were not different among the treatment groups. Generally, datasets were characterised by variations that exceeded those seen in studies in cell cultures. We conclude that holo-MCC and holo-PCC are the most reliable, single markers of biotin status tested in the present study.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

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