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4,934 result(s) for "False Positive Reactions"
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Risk of breast cancer after false‐positive results in mammographic screening
Women with false‐positive results are commonly referred back to routine screening. Questions remain regarding their long‐term outcome of breast cancer. We assessed the risk of screen‐detected breast cancer in women with false‐positive results. We conducted a joint analysis using individual level data from the population‐based screening programs in Copenhagen and Funen in Denmark, Norway, and Spain. Overall, 150,383 screened women from Denmark (1991–2008), 612,138 from Norway (1996–2010), and 1,172,572 from Spain (1990–2006) were included. Poisson regression was used to estimate the relative risk (RR) of screen‐detected cancer for women with false‐positive versus negative results. We analyzed information from 1,935,093 women 50–69 years who underwent 6,094,515 screening exams. During an average 5.8 years of follow‐up, 230,609 (11.9%) women received a false‐positive result and 27,849 (1.4%) were diagnosed with screen‐detected cancer. The adjusted RR of screen‐detected cancer after a false‐positive result was 2.01 (95% CI: 1.93–2.09). Women who tested false‐positive at first screen had a RR of 1.86 (95% CI: 1.77–1.96), whereas those who tested false‐positive at third screening had a RR of 2.42 (95% CI: 2.21–2.64). The RR of breast cancer at the screening test after the false‐positive result was 3.95 (95% CI: 3.71–4.21), whereas it decreased to 1.25 (95% CI: 1.17–1.34) three or more screens after the false‐positive result. Women with false‐positive results had a twofold risk of screen‐detected breast cancer compared to women with negative tests. The risk remained significantly higher three or more screens after the false‐positive result. The increased risk should be considered when discussing stratified screening strategies. In this joint analysis based on individual level data from the population‐based screening programs in Copenhagen and Funen in Denmark, Norway, and Spain, we estimated that women with false‐positive screening results had a twofold risk of a later screen detected breast cancer compared to women with negative screening results. The increased risk should be considered when exploring the possibilities of stratified screening strategies.
Women who are recalled for further investigation for breast screening: psychological consequences 3 years after recall and factors affecting re-attendance
Background In 1995-1996 a study was commenced investigating the experience of 'false-positive' women, i.e. who had undergone further investigations following routine breast screening and received a clear final result. These women were found to experience significantly greater adverse psychological consequences at 1 month, 5 months and 11 months after assessment compared with women who received a clear result after the initial basic mammogram. The present study follows up these 'false-positive' women 3 years later (at 35 months) just before being invited for their next routine breast screening. It investigates the effect of the previous experience of breast screening on adverse psychological consequences reported by false-positive women at this time, and explores factors that may be associated with the current adverse psychological consequences. Factors influencing attendance for the forthcoming appointment are reported, and the non-attendance rate is monitored. Methods Women who had previously completed a questionnaire 1 month, 5 months and 11 months after their last breast screening 3 years ago, were invited to complete a postal questionnaire just before being invited to attend for their next routine mammogram 3 years later. Attendance for this appointment was monitored. A brief questionnaire was sent to non-attenders to ascertain their reasons for not attending. Results The response rate was 77 per cent (387/505). Women who, at their last routine breast screening, had received a clear result after fine needle aspiration (FNA) at assessment, after a surgical biopsy or after a 6 month early recall appointment, all suffered significantly greater adverse psychological consequences at 1 month before returning for routine breast screening 3 years later than women who had received a clear result after the initial mammogram at their last routine breast screening. They were between 1.7 and 2 times more likely to suffer psychological consequences than women who received a clear result after their last mammogram. Women who had received a clear result at assessment without undergoing FNA reported higher psychological consequences than those who received a clear result after mammography, but the difference was not significant (relative risk 1.28, 95 per cent confidence interval 0.82-2.00). Fifteen per cent of those who had undergone assessment 3 years earlier did not attend their next routine breast screening appointment compared with 8 per cent of those who received a clear result after mammography (p = 0.035). Factors associated with adverse psychological consequences are reported. Conclusion Despite having received a final clear result during their previous routine breast screening 3 years ago, women who had undergone FNA, surgical biopsy or been placed on early recall suffered significantly greater adverse psychological consequences at 1 month before their next routine breast screening appointment than women who had received a clear result after their initial mammogram at their last routine breast screening. Having undergone further investigations did not necessarily motivate women to attend for their next routine appointment, with 15 per cent of these women not returning for routine screening 3 years on.
Small Pulmonary Artery Defects Are Not Reliable Indicators of Pulmonary Embolism
To evaluate the rate of agreement of pulmonary embolism diagnosis in computed tomography (CT) pulmonary angiogram studies and to evaluate the rate of inaccurate interpretations in the community hospital setting. Using the keywords \"pulmonary embolism/embolus/emboli,\" the radiology information system was searched for CT pulmonary angiograms performed over a 3-year period at three U.S. community hospitals. Studies containing probable or definite pulmonary emboli were independently reviewed by four subspecialty thoracic radiologists. Agreement about the presence of pulmonary embolism progressively decreased with decreasing diameter of pulmonary vascular lesions (P < 0.0001). There was a sharp fall in observer agreement for pulmonary embolism of subsegmental lesions (P < 0.0001). The frequency of agreement decreased with decreasing quality of the imaging examination (P < 0.0001). Community radiologists were prone to false-positive pulmonary embolism diagnosis of subsegmental and/or small pulmonary arterial defects. The probability of a false-positive diagnosis and indeterminate examinations progressively increased with: (1) more peripheral location of the lesion, (2) decreased size (short-axis diameter) of the lesion, and (3) diminishing quality of the CT examination. Forty-eight of 177 (27%) of subsegmental vascular defects identified by community radiologists were deemed indeterminate, and 27 of 177 (15%) of subsegmental vascular defects were judged to be false positive for pulmonary embolism by the consensus diagnosis. Fifty-four of 274 (20%) vascular defects with short axis less than 6 mm were indeterminate for pulmonary embolism, and 37 of 274 (14%) of vascular defects with short axis less than 6 mm were false positive for pulmonary embolism. Eleven of 13 (85%) of vascular lesions identified as pulmonary emboli on the lowest-quality CT examinations were false positive or indeterminate for pulmonary embolism. False-positive examinations were most often due to respiratory motion artifact (19/38, 50%). There is relatively poor interobserver agreement for subsegmental and/or small pulmonary artery defects, especially in CT pulmonary angiograms degraded by technical artifacts. These factors can lead to an increased frequency of inaccurate interpretation or indeterminate diagnosis of subsegmental and/or small defects. Caution is indicated in interpreting the significance of small vascular defects in CT pulmonary angiograms.
Preventing further misuse of the ELISA technique and misinterpretation of serological antibody assay data
The indirect ELISA is a widely utilized method to assay serum antibodies. However, a common and critical problem when analyzing serum antibodies is the disregard for the background noise reaction caused by the hydrophobic binding of immunoglobulin components in serum components to plastic. Unfortunately, current blocking agents cannot prevent this background noise reaction. To prevent further misuse of the ELISA technique, it is important to openly discuss the fundamental problems involved in the ELISA system.
Revisiting ALK (D5F3) immunohistochemistry: Insights into focal staining and neuroendocrine differentiation
Background Screening for anaplastic lymphoma kinase (ALK) rearranged non‐small cell lung cancer (NSCLC) is crucial for identifying patients eligible for targeted therapy. The FDA‐approved ALK (D5F3) immunohistochemistry (IHC) assay, used with the OptiView Amplification Kit, demonstrates excellent sensitivity and specificity in detecting these patients. However, the clinical significance of resulting focal positivity remains unclear, and ALK (D5F3) expression unrelated to ALK fusion is observed in some cases of neuroendocrine differentiation. This study aims to validate these findings with molecular testing and contribute to the accurate interpretation of ALK (D5F3) IHC results. Methods A total of 1619 patients diagnosed with NSCLC and neuroendocrine carcinoma were evaluated using ALK (D5F3) IHC. For cases with strong but focal expression and those with diffuse strong positivity in neuroendocrine differentiation, ALK fluorescence in situ hybridization (FISH) and/or next‐generation sequencing (NGS) tests were performed. Results Seven out of 1109 adenocarcinomas (0.6%) and six out of 289 squamous cell carcinomas (2.1%) exhibited strong focal ALK (D5F3) expression. Nine out of 209 neuroendocrine carcinomas (4.3%) showed homogeneously strong ALK (D5F3) expression. All these cases, including adenocarcinoma with neuroendocrine differentiation and combined small cell carcinoma, were negative for ALK fusions by FISH and/or NGS. Conclusion This study demonstrates that strong but focal ALK (D5F3) immunostaining and strong expression in neuroendocrine differentiation may not indicate ALK fusion. By considering these findings, we can improve the accuracy of patient selection for targeted therapy by minimizing false‐positive interpretations of ALK (D5F3) staining. We investigated the clinical significance of focal strong ALK (D5F3) immunostaining in NSCLC and neuroendocrine differentiation cases. Our findings revealed that these staining patterns can occur independently of ALK fusion, suggesting the need for revised interpretation guidelines to avoid false‐positive results and improve patient selection for targeted therapy.
A case of glyphosate poisoning with falsely elevated creatinine levels measured by dry chemistry methods
Background The ingestion of glyphosate herbicides can cause severe acute kidney injury. We present a case of glyphosate poisoning in which creatinine levels were falsely elevated when measured using a dry chemistry analyzer. Case Presentation An 83‐year‐old man ingested glyphosate herbicide during a suicide attempt and presented with gastrointestinal symptoms. A dry chemistry analyzer showed high creatinine levels (10.62 mg/dL); thus, the patient was transported to our hospital for renal replacement therapy. However, enzymatic testing showed a lower creatinine level (1.36 mg/dL). Further investigation comparing creatinine measurements revealed a high creatinine level only through the dry chemistry method, despite the relatively low glyphosate concentration (55 mg/L). Conclusion The dry chemistry method falsely shows an elevated creatinine value, which may affect clinical decisions regarding the management of patients with glyphosate poisoning. Careful interpretation of creatinine measurements using the dry chemistry method is important in glyphosate poisoning cases. We describe a case of glyphosate poisoning in which creatinine levels were determined to be elevated using dry chemistry. Because the assay uses ammonia to measure creatinine levels, the ammonia generated from the isopropylamine salt in the glyphosate herbicide solution interferes with the assay, resulting in falsely high creatinine levels.
Scaling up COVID-19 rapid antigen tests: promises and challenges
WHO recommends a minimum of 80% sensitivity and 97% specificity for antigen-detection rapid diagnostic tests (Ag-RDTs), which can be used for patients with symptoms consistent with COVID-19. However, after the acute phase when viral load decreases, use of Ag-RDTs might lead to high rates of false negatives, suggesting that the tests should be replaced by a combination of molecular and serological tests. When the likelihood of having COVID-19 is low, such as for asymptomatic individuals in low prevalence settings, for travel, return to schools, workplaces, and mass gatherings, Ag-RDTs with high negative predictive values can be used with confidence to rule out infection. For those who test positive in low prevalence settings, the high false positive rate means that mitigation strategies, such as molecular testing to confirm positive results, are needed. Ag-RDTs, when used appropriately, are promising tools for scaling up testing and ensuring that patient management and public health measures can be implemented without delay.
LTR_retriever
Long terminal repeat retrotransposons (LTR-RTs) are prevalent in plant genomes. The identification of LTR-RTs is critical for achieving high-quality gene annotation. Based on the well-conserved structure, multiple programs were developed for the de novo identification of LTR-RTs; however, these programs are associated with low specificity and high false discovery rates. Here, we report LTR_retriever, a multithreading-empowered Perl program that identifies LTR-RTs and generates high-quality LTR libraries from genomic sequences. LTR_retriever demonstrated significant improvements by achieving high levels of sensitivity (91%), specificity (97%), accuracy (96%), and precision (90%) in rice (Oryza sativa). LTR_retriever is also compatible with long sequencing reads. With 40k self-corrected PacBio reads equivalent to 4.5× genome coverage in Arabidopsis (Arabidopsis thaliana), the constructed LTR library showed excellent sensitivity and specificity. In addition to canonical LTR-RTs with 5'-TG...CA-3' termini, LTR_retriever also identifies noncanonical LTR-RTs (non-TGCA), which have been largely ignored in genome-wide studies. We identified seven types of noncanonical LTRs from 42 out of 50 plant genomes. The majority of noncanonical LTRs are Copia elements, with which the LTR is four times shorter than that of other Copia elements, which may be a result of their target specificity. Strikingly, non-TGCA Copia elements are often located in genic regions and preferentially insert nearby or within genes, indicating their impact on the evolution of genes and their potential as mutagenesis tools.
High false-positive response in perimetry
In Humphrey visual field analyzer, the false-positive (FP) responses imply that the patient has pressed the response button despite no stimulus being seen at the time of response and FP rates >15 are flagged. The classical \"Trigger happy\" visual field has increased fixation loss, very high threshold retinal sensitivity with the values in supernormal range, \"white scotoma\" on grayscale map, high positive mean deviation (MD), glaucoma hemifield test (GHT) gives classification of \"abnormally high sensitivity, ‘Excessive high false positive' message is displayed,\" and pattern deviation probability plot has more defects than total deviation probability plot known as \"reverse cataract pattern.\" However, these classical findings are not seen in all the cases of FP as the same thumb rule cannot be applied to all the visual fields with high FP. This video emphasizes the significance of careful examination of all the parameters in a visual field printout of high FP to interpret the test results and the caution needed when an FP response is seen in a patient with advanced glaucoma. The video presents some interesting visual fields in normal and glaucoma patients and the effect of high FP responses on MD, the different classification messages displayed for GHT, patterns of total deviation probability plot and pattern deviation probability plot, and how to identify the hidden FP.