Immunochemical reactions are fast, can be automated, and generally do not require pretreatment of biological material. Based on these advantages, they are widely used. On the other hand, they are susceptible to analytical interference that can lead to inaccurate results. These factors include the presence of anti-mouse antibodies, causing false positive (or sometimes false negative) results. Although the anti-mouse antibodies over many decades have been repeatedly identified to be the causative source but due to the rarity of such encounters they remain insufficiently considered. Here we show a case, a 45 year-old female who was mis-diagnosed with pregnancy due to falsely elevated human chorionic gonadotropin (hCG) due to anti-mouse antibodies. This led to the patient undergoing two ultrasound examinations and laparoscopy before the hCG was repeated on alternative assays which showed negative results, preventing the patient from methotrexate treatment. Here we describe the details of the case, outline the assay principal, supporting the finding from literature and outlining a process on how to identify such interferences in timely manner.

• Klíčová slova
• anti-mouse antibodies, false positivity, hCG, interferences, pregnancy,
• MeSH
• choriogonadotropin * MeSH
• falešně pozitivní reakce MeSH
• lidé středního věku MeSH
• lidé MeSH
• protilátky * MeSH
• těhotenství MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• choriogonadotropin * MeSH
• protilátky * MeSH

We are reporting a study evaluating the crossover of antigens reacting in Platelia Aspergillus (PA) enzyme-linked immunosorbent assay (ELISA) from faeces to vessels during mucositis as a possible cause of false-positivity of this test. In our series of 102 episodes of different grades of mucositis, we found strong reactivity of faeces in the PA ELISA test irrespective of the grade of mucositis, the percentage of oral food intake or the presence of total parenteral nutrition. However, none of the patients included in the study were positive in the serum (when the criterion of two samples with cut-off index of positivity [IP] > 0.5 was used).

• MeSH
• Aspergillus imunologie   izolace a purifikace   MeSH
• aspergilóza diagnóza   MeSH
• dospělí MeSH
• ELISA metody   MeSH
• falešně pozitivní reakce * MeSH
• feces mikrobiologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mukozitida komplikace   MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH

Some compounds without apparent chelation sites have been shown to chelate cupric ions using the hematoxylin assay. Since these compounds also have reduction potential (direct antioxidant effect), the aim of this study was to determine the possible interference of reducing agents with the hematoxylin assay. Four different known reducing agents (hydroxylamine, vitamin C, trolox - a water-soluble form of vitamin E and reduced glutathione /GSH/) were selected for the study together with oxidized glutathione (GSSG) for comparison. All tested compounds behaved as cupric chelators in the spectrophotometric mildly competitive hematoxylin assay. In-depth analysis however showed that only GSH and GSSG were able to form complexes with both cupric and cuprous ions and only GSSG partly retained copper in its complexes in the more competitive bathocuproine assay. Further experiments showed that with the exception of GSSG, all other compounds reduce Cu2+ ions. Conclusion: Compounds reducing copper such as antioxidants can give false positive results in the hematoxylin-screening assay. GSSG is a stronger Cu chelator than GSH and does not reduce Cu, in contrast to the latter and thus may be a protective element after oxidation of GSH.

• Klíčová slova
• Complex, Copper, Glutathione, Hematoxylin, Stoichiometry,
• MeSH
• chelátory chemie   MeSH
• falešně pozitivní reakce * MeSH
• hematoxylin chemie   MeSH
• měď chemie   MeSH
• molekulární konformace MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chelátory MeSH
• cuprous ion MeSH Prohlížeč
• hematoxylin MeSH
• měď MeSH

Results of meta-analyses are regarded as the highest level of evidence. A statistically non-significant effect size from a meta-analysis is typically considered true negative even in the presence of a statistically significant signal in individual studies, presumed to be false positive. Here we provide examples from neuroimaging, genetics and psychopharmacology of why meta-analyses may frequently yield false negative results from true positive findings. This may happen in situations when individual studies report findings in opposing directions, the sum of which yields a non-significant overall effect size. Such non-significant meta-analyses, which show statistical heterogeneity and include studies with opposing effect sizes do not provide an accurate estimate of the overall effect and may have lower heuristic value than individual studies. Over reliance on such meta-analyses may falsely identify certain potentially fruitful research avenues as blind alleys.

• Klíčová slova
• False negative, Meta-analyses, Statistical heterogeneity,
• MeSH
• biomedicínský výzkum metody   MeSH
• genetické asociační studie MeSH
• lidé MeSH
• medicína založená na důkazech * MeSH
• metaanalýza jako téma * MeSH
• neurozobrazování MeSH
• psychofarmakologie metody   MeSH
• reprodukovatelnost výsledků MeSH
• statistické modely * MeSH
• velikost vzorku MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A male patient had undergone total thyroidectomy for thyroid papillary carcinoma. He was administered thyroablation activity of radioiodine. Whole body imaging after diagnostic activity of 131-I demonstrated intense radioiodine uptake in the right side of the upper abdominal region. The serum thyroglobulin level was low. Ultrasonography demonstrated a large irregular anechoic structure in the centre of the right kidney--a cyst in the parapelvic region. Renal cysts can lead to erroneous interpretation of radioiodine scintigraphy.

• MeSH
• biologický transport MeSH
• cystická onemocnění ledvin diagnostické zobrazování   metabolismus   patologie   MeSH
• falešně pozitivní reakce MeSH
• lidé MeSH
• pánev diagnostické zobrazování   patologie   MeSH
• radioisotopová scintigrafie MeSH
• radioizotopy jodu metabolismus   MeSH
• senioři MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• radioizotopy jodu MeSH

Inter-rater reliability (IRR) is one of the commonly used tools for assessing the quality of ratings from multiple raters. However, applicant selection procedures based on ratings from multiple raters usually result in a binary outcome; the applicant is either selected or not. This final outcome is not considered in IRR, which instead focuses on the ratings of the individual subjects or objects. We outline the connection between the ratings' measurement model (used for IRR) and a binary classification framework. We develop a simple way of approximating the probability of correctly selecting the best applicants which allows us to compute error probabilities of the selection procedure (i.e., false positive and false negative rate) or their lower bounds. We draw connections between the IRR and the binary classification metrics, showing that binary classification metrics depend solely on the IRR coefficient and proportion of selected applicants. We assess the performance of the approximation in a simulation study and apply it in an example comparing the reliability of multiple grant peer review selection procedures. We also discuss other possible uses of the explored connections in other contexts, such as educational testing, psychological assessment, and health-related measurement, and implement the computations in the R package IRR2FPR.

• Klíčová slova
• Type I error, Type II error, error rate, mixed‐effect models, rating,
• MeSH
• falešně pozitivní reakce MeSH
• lidé MeSH
• odchylka pozorovatele MeSH
• počítačová simulace MeSH
• posudkové řízení metody   MeSH
• pravděpodobnost MeSH
• reprodukovatelnost výsledků MeSH
• statistické modely * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Minimal residual disease (MRD) monitoring via quantitative PCR (qPCR) detection of Ag receptor gene rearrangements has been the most sensitive method for predicting prognosis and making post-transplant treatment decisions for patients with ALL. Despite the broad clinical usefulness and standardization of this method, we and others have repeatedly reported the possibility of false-positive MRD results caused by massive B-lymphocyte regeneration after stem cell transplantation (SCT). Next-generation sequencing (NGS) enables precise and sensitive detection of multiple Ag receptor rearrangements, thus providing a more specific readout compared to qPCR. We investigated two cohorts of children with ALL who underwent SCT (30 patients and 228 samples). The first cohort consisted of 17 patients who remained in long-term CR after SCT despite having low MRD positivity (<0.01%) at least once during post-SCT monitoring using qPCR. Only one of 27 qPCR-positive samples was confirmed to be positive by NGS. Conversely, 10 of 15 samples with low qPCR-detected MRD positivity from 13 patients who subsequently relapsed were also confirmed to be positive by NGS (P=0.002). These data show that NGS has a better specificity in post-SCT ALL management and indicate that treatment interventions aimed at reverting impending relapse should not be based on qPCR only.

• MeSH
• akutní lymfatická leukemie * krev   diagnóza   genetika   terapie   MeSH
• dítě MeSH
• falešně pozitivní reakce MeSH
• lidé MeSH
• mladiství MeSH
• polymerázová řetězová reakce * MeSH
• předškolní dítě MeSH
• prognóza MeSH
• reziduální nádor MeSH
• transplantace hematopoetických kmenových buněk * MeSH
• vysoce účinné nukleotidové sekvenování * MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• multicentrická studie MeSH

False alarms in intensive care units represent a serious threat to patients. We propose a method for detection of five live-threatening arrhythmias. It is designed to work with multimodal data containing electrocardiograph and arterial blood pressure or photoplethysmograph signals. The presented method is based on descriptive statistics and Fourier and Hilbert transforms. It was trained using 750 records. The method was validated during the follow-up phase of the CinC/Physionet Challenge 2015 on a hidden dataset with 500 records, achieving a sensitivity of 93% (95%) and a specificity of 87% (88%) for real-time (retrospective) files. The given sensitivity and specificity resulted in score of 81.62 (84.96) for real-time (retrospective) records. The presented method is an improved version of the original algorithm awarded the first and the second prize in CinC/Physionet Challenge 2015.

• MeSH
• algoritmy * MeSH
• elektrokardiografie přístrojové vybavení   MeSH
• falešně pozitivní reakce MeSH
• fotopletysmografie přístrojové vybavení   MeSH
• jednotky intenzivní péče * MeSH
• klinické alarmy * MeSH
• krevní tlak MeSH
• lidé MeSH
• monitorování fyziologických funkcí přístrojové vybavení   MeSH
• počítačové zpracování signálu * MeSH
• srdeční arytmie diagnóza   patofyziologie   MeSH
• strojové učení MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• dospělí MeSH
• falešně pozitivní reakce MeSH
• fibrinogen analýza   MeSH
• lidé středního věku MeSH
• lidé MeSH
• radioizotopy jodu * MeSH
• senioři MeSH
• tromboflebitida diagnóza   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fibrinogen MeSH
• radioizotopy jodu * MeSH

• MeSH
• falešně pozitivní reakce MeSH
• kožní testy * přístrojové vybavení   metody   MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH