scholarly journals A COVID-19 from Laboratory Suspicion to Confirmatory Tests: Controversial Debatable

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Elsayed Yasser Mohammed Hassanain
Keyword(s):  
Confirmatory Tests

OPTIMISATION OF SAND CASTING PROCESS FOR IMPELLER USING TAGUCHI METHODOLOGY

2020 ◽  
Vol XVII (2) ◽  
pp. 23-33
Author(s):  
Faisal Hafeez ◽  
Salman Hussain ◽  
Wasim Ahmad ◽  
Mirza Jahanzaib
Keyword(s):  
Surface Roughness ◽  
Surface Defects ◽  
A356 Alloy ◽  
Casting Process ◽  
Sand Casting ◽  
Gate Length ◽  
Taguchi Methodology ◽  
Confirmatory Tests ◽  
Binder Ratio ◽  
Response Measures

This paper presents the study to investigate the effects of binder ratio, in-gate length and pouring height on hardness, surface roughness and casting defects of sand casting process. Taguchi methodology with L9 orthogonal array was employed to design the experimentation. Sand casting of six blade impeller using A356 alloy was performed and empirical models for all the above response measures were formulated. Confirmatory tests and analysis of variance results confirmed the accuracy of the model. Binder ratio was found to be the most significant parameter affecting casting surface defects and surface roughness. This was followed by pouring height and in-gate length.

Chronic Wasting Disease Options of Surveillance in Carpathian Cervids: from the Identification of Characteristic Microscopic Pathologic Changes to Prionic Seeded Conversion and Amplification Assays

2001 ◽  
Vol 71 (3) ◽  
pp. 480-486
Author(s):  
Florica Barbuceanu ◽  
Stelian Baraitareanu ◽  
Stefania-Felicia Barbuceanu ◽  
Gabriel Predoi
Keyword(s):  
Enzyme Immunoassay ◽  
Diagnostic Tests ◽  
Chronic Wasting Disease ◽  
Rapid Diagnostic Tests ◽  
Diagnostic Methods ◽  
Wasting Disease ◽  
Western Immunoblotting ◽  
Negative Results ◽  
Antigen Capture ◽  
Confirmatory Tests

This paper describes the current diagnostic methods of Chronic Wasting Disease (CWD) in cervides used between 2013 and 2017 in Romania. The active surveillance of CWD involves the targeted groups screening by using rapid diagnostic tests (e.g., antigen capture enzyme immunoassay). If the first test does not provide certain negative results, then the confirmatory methods have been used, i.e. histopathology, immunohistochemistry and Western immunoblotting. These tests did not lead to the detection of CWD prions (PrPCWD) in Romania. This may be due to the absence or insufficient quantity of PrPCWD in samples, below the threshold of confirmatory tests.

Bacillary Angiomatosis: A Unique Cutaneous Complication of Hiv Infection

1995 ◽  
Vol 3 (2) ◽  
pp. 1-10
Author(s):  
Joan Lipa ◽  
Walter Peters ◽  
Victor Fornasier ◽  
Benjamin Fisher
Keyword(s):  
Hiv Infection ◽  
Definitive Diagnosis ◽  
Causal Organism ◽  
Bacillary Angiomatosis ◽  
Immunodeficiency Virus ◽  
Confirmatory Tests ◽  
Nodular Lesions ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome ◽  
Erythromycin Therapy

As the prevalence of human immunodeficiency virus (HIV) infection increases, so does the recognition of unusual manifestations of this syndrome. This study describes two patients who presented with a unique, rare, cutaneous manifestion of HIV infection. One patient developed an aggressive atypical cellulitis and ascending lymphangitis of the hand, which failed to improve following multiple courses of several different antibiotics. The other patient presented with multiple, vascular, nodular lesions, clinically resembling Kaposi's sarcoma. Routine biopsies and wound cultures were not helpful for diagnosis. A definitive diagnosis of bacillary angiomatosis (BA) was made using a special silver-staining (Warthin-Starry) histological technique and electron microscopy. Both patients responded completely to oral erythromycin therapy. BA is a newly recognized bacterial infection caused by bacteria of the genus Bartonella. It is seen primarily in patients with acquired immunodeficiency syndrome (AIDS), and less commonly in patients with other immunosuppressed conditions. The term BA describes the lesion's pathogenesis (infective-bacillary) and clinico-histology (angiomatosis). The causal organism cannot be cultured reliably and is resistant to most antibiotics. This study reviews these two patients, the differential diagnosis of BA, specific confirmatory tests used in diagnosis, and the treatment outcome of this condition. It is important for the plastic surgeon to understand BA, because it can resemble other common presentations, but it can also be associated with internal involvement leading to mortality. However, when recognized, it can usually be cured by oral erythromycin therapy (500 mg qid) for several weeks.

scholarly journals Seroprevalence and correlates of SARS-CoV-2 neutralizing antibodies from a population-based study in Bonn, Germany

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
N. Ahmad Aziz ◽  
Victor M. Corman ◽  
Antje K. C. Echterhoff ◽  
Marcel A. Müller ◽  
Anja Richter ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Response Rate ◽  
Neutralization Test ◽  
Population Based ◽  
Immunofluorescence Assay ◽  
Test Results ◽  
Community Based ◽  
Population Based Study ◽  
Temporal Course ◽  
Confirmatory Tests

AbstractTo estimate the seroprevalence and temporal course of SARS-CoV-2 neutralizing antibodies, we embedded a multi-tiered seroprevalence survey within an ongoing community-based cohort study in Bonn, Germany. We first assessed anti-SARS-CoV-2 immunoglobulin G levels with an immunoassay, followed by confirmatory testing of borderline and positive test results with a recombinant spike-based immunofluorescence assay and a plaque reduction neutralization test (PRNT). Those with a borderline or positive immunoassay result were retested after 4 to 5 months. At baseline, 4771 persons participated (88% response rate). Between April 24th and June 30th, 2020, seroprevalence was 0.97% (95% CI: 0.72−1.30) by immunoassay and 0.36% (95% CI: 0.21−0.61) when considering only those with two additional positive confirmatory tests. Importantly, about 20% of PRNT+ individuals lost their neutralizing antibodies within five months. Here, we show that neutralizing antibodies are detectable in only one third of those with a positive immunoassay result, and wane relatively quickly.

Evaluation of methods for detection of β-lactamase production in MSSA

2021 ◽  
Author(s):  
Robert Skov ◽  
David R Lonsway ◽  
Jesper Larsen ◽  
Anders Rhod Larsen ◽  
Jurgita Samulioniené ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Confirmatory Test ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Confirmatory Tests ◽  
Correct Determination ◽  
Primary Test ◽  
Zone Edge ◽  
Evaluation Of Methods

Abstract Objectives Correct determination of penicillin susceptibility is pivotal for using penicillin in the treatment of Staphylococcus aureus infections. This study examines the performance of MIC determination, disc diffusion and a range of confirmatory tests for detection of penicillin susceptibility in S. aureus. Methods A total of 286 consecutive penicillin-susceptible S. aureus blood culture isolates as well as a challenge set of 62 MSSA isolates were investigated for the presence of the blaZ gene by PCR and subjected to penicillin-susceptibility testing using broth microdilution MIC determination, disc diffusion including reading of the zone edge, two nitrocefin tests and the cloverleaf test. Results Using PCR-based detection of blaZ as the gold standard, both broth microdilution MIC testing and disc diffusion testing resulted in a relatively low accuracy (82%–93%) with a sensitivity ranging from 49%–93%. Among the confirmatory tests, the cloverleaf test performed with 100% accuracy, while zone edge interpretation and nitrocefin-based tests increased the sensitivity of β-lactamase detection to 96%–98% and 82%–96% when using MIC determination or disc diffusion as primary test, respectively. Conclusions This investigation showed that reliable and accurate detection of β-lactamase production in S. aureus can be obtained by MIC determination or penicillin disc diffusion followed by interpretation of the zone edge as a confirmatory test for apparently penicillin-susceptible isolates. The more cumbersome cloverleaf test can also be used. Nitrocefin-based tests should not be used as the only test for confirmation of a presumptive β-lactamase-negative isolate.

Confirmatory Tests for Aflatoxin B1

1964 ◽  
Vol 47 (5) ◽  
pp. 801-803 ◽  
Author(s):  
Peter John Andrellos ◽  
George R Reid
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Formic Acid ◽  
Thionyl Chloride ◽  
Aflatoxin B1 ◽  
Trifluoroacetic Acid ◽  
Reaction Products ◽  
Confirmatory Tests ◽  
Aflatoxin B ◽  
Layer Chromatography

Abstract Three confirmatory tests have been devised to identify aflatoxin B±. Portions of the isolated toxin are treated with formic acid-thionyl chloride, acetic acid-thionyl chloride, and trifluoroacetic acid, respectively, and aliquots of the three fluorescent reaction products are spotted on thin-layer chromatography plates. Standards treated with each of the three reagents, plus an untreated standard, are spotted on the same plate, and after development the spots are compared under ultraviolet light.

scholarly journals Combination of Modified Atmosphere and Irradiation for the Phytosanitary Disinfestation of Trogoderma granarium Everts (Coleoptera: Dermestidae)

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 442
Author(s):  
Qing-Ying Zhao ◽  
Tian-Xiu Li ◽  
Zi-Jiao Song ◽  
Tao Sun ◽  
Bo Liu ◽  
...  
Keyword(s):  
Late Stage ◽  
Synergistic Effects ◽  
Combined Treatment ◽  
Modified Atmosphere ◽  
Trogoderma Granarium ◽  
Combination Treatments ◽  
Phytosanitary Measure ◽  
Ma Packaging ◽  
Confirmatory Tests ◽  
Lethal Time

The khapra beetle, Trogoderma granarium Everts, is defined as one of the most important quarantine pests globally, and fumigation with methyl bromide, an ozone-depleting substance, is a common phytosanitary measure currently used. The modified atmosphere (MA), irradiation, and their combination treatments of T. granarium larvae and adults were performed at room temperature (24–26 ℃) to develop an ecofriendly phytosanitary disinfestation measure and to shorten the exposure time and overcome treatment disadvantages of irradiation. Late-stage larvae are determined as the most tolerant stage resulted in large LT99.9968 values of 32.6 (29.2–37.5) and 38.0 (35.1–41.7) days treated under 1% and 2% O2 (with N2 balance) atmosphere, respectively. Ionizing radiation was used to enhance the effect of MA and the mortality was highly significantly affected by all the interaction effects, indicating that the synergistic effects present in all the combined treatments. The synergistic ratios, which is defined as the estimated lethal time for MA treatment (LD90, LD99, and LD99.9968), divided by that of combined treatment, were between 1.47 and 2.47. In the confirmatory tests, no individuals recovered from a sum of 111,366 late-stage larvae treated under 1% O2 atmosphere for 14- or 15-d after 200 Gy irradiation, which resulted in validating the probit estimations and achieving an efficacy of 99.9973% mortality at 95% confidence level. Therefore, these treatment schedules are recommended to disinfest T. granarium infecting commodities for phytosanitary purposes under the warehouse, MA packaging, or in combination with international transportation by train or sea container.

Clinical and laboratory changes in the hemostasis system in patients with optic nerve vasculitis

2021 ◽  
pp. 23-27
Author(s):  
T.V. Shelkovnikova ◽  
◽  
H.P. Takhchidi ◽  
G.V. Nikolaeva ◽  
G.V. Vavin ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Research Methods ◽  
Lupus Anticoagulant ◽  
Young Patients ◽  
Venous Stasis ◽  
Hemostasis System ◽  
Hemostatic System ◽  
Retinal Microvasculature ◽  
Confirmatory Tests ◽  
Laboratory Changes

Purpose. Clinical and laboratory studies of the hemostasis system in patients with optic nerve vasculitis. Materials and methods. Medical records and case history of 45 people (49 eyes) were analyzed, of which pathology in two eyes was detected in 4 people (8 eyes). The study involved 24 men and 21 women aged 17 to 35 years. The follow-up period ranged from 3 months to 5 years. Standard ophthalmic research methods and special research methods were used. Laboratory methods for the study of hemostasis included the detection of lupus anticoagulant was carried out using poison tests, as well as confirmatory tests with donor plasma and corrective phospholipids. Results. Retinopathy of the type of venous stasis was found in 30 people, neuropathy of the type of stagnant disc – in 15 people. In young patients after a viral infection with damage to the optic nerve in clinical form, retinopathy such as venous stasis and congestive optic nerve head with lupus anticoagulant was found in 73.4% of cases. In patients with vasculitis of the optic nerve with lupus anticoagulant, disturbances in the vascular-platelet and plasma-coagulation links in the hemostatic system were revealed. Conclusion. Lupus anticoagulant significantly reduces thromboresistance of the endothelium of the retinal microvasculature and enhances hypercoagulation, breaks the natural regulation of the hemostasis system and aggravates ischemia of the retina, optic nerve, participates in the pathogenesis of clinical forms of optic nerve vasculitis. Key words: hemostatic system, lupus anticoagulant, thrombophilia, optic nerve vasculitis.

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