False negative breast cancers on imaging and associated risk factors: a single institution six-year analysis.

PURPOSE: Mitigating false negative imaging studies remains an important issue given its association with worse morbidity and mortality in patients with breast cancer. We aimed to identify risk factors that predispose to false negative breast imaging exams. METHODS: In an IRB-approved, HIPAA compliant retrospective study, we identified all patients who were diagnosed with breast cancer within 365 days of a negative imaging study assessed as BI-RADS 1-3 between January 1, 2014 and January 31, 2020. A matched cohort based on mammographic breast density was created from randomly selected studies with BI-RADS 4-5 designation that yielded breast cancer at pathology within the same time frame. Patient and cancer characteristics, prior personal history of breast cancer and gene mutation status were collected from patient charts. Pearson chi-squared and Student's t-test on two independent groups with significance at < 0.05 was used for statistical analysis. RESULTS: We identified 155 false negative studies of 129 missed cancers and 128 breast density matched true positive cancers. False negative studies were screening mammograms in 57.42% (89/155), diagnostic mammograms in 29.68% (46/155), ultrasounds in 6.45% (10/155) and MRIs in 6.45% (10/155). Rates of personal (41.09% vs. 18.75%, p < 0.001) and family history of breast cancer (68.22% vs. 49.21%, p = 0.002) were higher in the false negative cohort and remained significant when asymptomatic MRI-detected cancers were removed. CONCLUSION: Our findings suggest that supplemental screening may be useful in breast cancer survivors.

Are There More HER2 FISH in the Sea? An Institution's Experience in Identifying HER2 Positivity Using Fluorescent In Situ Hybridization in Patients with HER2 Negative Immunohistochemistry.

BACKGROUND: Approximately 20% of breast cancers express HER2-positive receptors in the USA. HER2 receptor immunohistochemistry (IHC) staining with equivocal (2+) results commonly undergoes fluorescence in-situ hybridization (FISH) for further classification. Current guidelines do not recommend routine FISH testing in IHC-negative (0 or 1+) cases. This study investigates an institution that performs both IHC and FISH testing on all cases to identify the true HER2-positive rate. PATIENTS AND METHODS: A retrospective chart review from 2015 to 2021 was conducted at an institution where both HER2 IHC and FISH testing were performed at the time of diagnosis for all invasive breast cancers. The rate of true HER2-positive patients was determined, and patient and tumor characteristics were further explored. RESULTS: A total of 1835 invasive breast cancer cases were primarily treated at this institution. A total of 289 cases were HER2 positive on IHC and FISH testing (15.7%). An additional 38 cases were identified as HER2 negative on IHC, but reclassified as HER2 positive on reflex FISH testing. Total HER2 positive cases increased from 289 (15.7%) to 327 cases (17.8%) with reflex FISH testing. CONCLUSIONS: The additional HER2-positive cases after completing FISH testing on IHC-negative tumors suggests there may be a role for routine FISH testing in addition to standard IHC staining to determine HER2 status for breast cancer. The ethical, prognostic and even  benefits of a correct diagnosis outweigh the added expense of FISH testing.

Clipped Axillary Node as a Potential Surrogate for Overall Axillary Nodal Status in Inflammatory Breast Cancer Patients after Neoadjuvant Chemotherapy.

BACKGROUND: Axillary lymph node dissection is the current standard for management of the axilla in inflammatory breast cancer (IBC). The present study aims to determine whether the initially positive node identified by clip placement accurately represents the overall nodal status of axilla after neoadjuvant chemotherapy (NAC) in IBC. PATIENTS AND METHODS: A retrospective study was conducted on patients with IBC who underwent operation (2014-2023). For patients with IBC who had clip placement in a positive axillary node at diagnosis, operative notes, specimen radiographs, and pathology reports were reviewed to confirm final pathologic status of clipped nodes. RESULTS: In total, 92 patients with IBC (90 cN+) were identified (median age 54 years, 78% invasive ductal, 10% invasive lobular, and 12% mixed); 81 (90%) were biopsy-proven cN+, with a clip placed in the positive node for 62/81 (77%). All patients were treated with NAC and axillary surgery with median 19 (range 4-49) nodes removed. Among 28 (out of 56) patients with retrieved clipped nodes that were pathologically negative (ypN0), only 1 had an additional positive node with micrometastasis for a false negative rate of 4% (95% CI 1-19%). Conversely, 3/3 patients with isolated tumor cells (ITCs) only in the clipped node had additional axillary disease (ITCs in 1, macrometastasis in 2), and 20/23 (87%) of patients with pathologically positive clipped node (micrometastasis or greater) had additional positive nodes [19/20 (95%) with macrometastasis]. CONCLUSIONS: The clipped biopsy-positive axillary node in IBC accurately represented the post-NAC overall axillary nodal status. ITCs post-NAC should be considered positive as an indicator of additional nodes with metastasis.

New EAU/ASCO guideline recommendations on sentinel node biopsy for penile cancer and remaining challenges from a nuclear medicine perspective.

INTRODUCTION: The European Association of Urology (EAU) and the American Society of Clinical Oncology (ASCO) recently issued updated guidelines on penile cancer, emphasising dynamic sentinel node biopsy (DSNB) as the preferred method for surgical staging among patients with invasive penile tumours and no palpable inguinal lymphadenopathy. This paper outlines the rationale behind this new recommendation and describes remaining challenges, as well as strategies for promoting DSNB worldwide. MAIN TEXT: DSNB offers high diagnostic accuracy with the lowest postoperative complications compared to open or minimally invasive inguinal lymph node dissection (ILND), prompting its preference in the new guidelines. Nevertheless, despite its advantages, there are challenges hampering the widespread adoption of DSNB. This includes the false-negative rate associated with DSNB and the potential negative impact on patient outcome. To address this issue, improvements should be made in several areas, including refining the timing and interpretation of the lymphoscintigraphy and the single photon emission computed tomography/computed tomography images. In addition, the quantity of tracer employed and choice of the injection site for the radiopharmaceutical should be optimised. Finally, limiting the removal of nodes without tracer activity during surgery may help minimise complication rates. CONCLUSION: Over the years, DSNB has evolved significantly, related to the dedicated efforts and innovations in nuclear medicine and subsequent clinical studies validating its efficacy. It is now strongly recommended for surgical staging among selected penile cancer patients. To optimise DSNB further, multidisciplinary collaborative research is required to improve SN identification for better diagnostic accuracy and fewer complications.

Characterization of the alcohol biomarker phosphatidylethanol in donor whole blood and apheresis red blood cells: Implications for transfusion recipients.

INTRODUCTION: Phosphatidylethanol (PEth) is a long-term marker of alcohol consumption used frequently in clinical scenarios such as liver transplant evaluation. Recent cases have demonstrated that packed red blood cell (pRBC) transfusion creates the potential for artificial elevation or decrease of observed PEth concentrations in recipients. Very little is known about the prevalence or stability of PEth in pRBCs. METHODS: Apheresis and whole-blood (WB) donations were tested for PEth using liquid chromatography - tandem mass spectrometry with limit of quantitation 10 ng/mL. Units were stored under routine blood bank conditions to evaluate the stability of PEth and the impact of irradiation. RESULTS: Over 40% of apheresis and WB donors had PEth ≥10 ng/mL (maximum observed 587 ng/mL). As WB units were processed into component pRBCs, PEth concentrations increased and were higher than donor WB levels (EDTA sample) prior to collection (maximum observed 711 ng/mL). Storage for up to 5 weeks post donation resulted in mean 17.3% decrease in PEth-positive units; in contrast to a prior report, we observed no PEth formation in units with negative (<10 ng/mL) baseline concentrations. Irradiation of pRBCs did not substantially affect PEth concentrations in either PEth-positive or PEth-negative units. DISCUSSION: PEth concentrations in healthy blood donors may potentially confound alcohol use or abstinence assessment in pRBC recipients. Transfusion medicine services and clinical practices such as transplantation and behavioral medicine should recognize this phenomenon and collaborate on testing protocols to appropriately interpret PEth in pRBC recipients.

The features associated with mammography-occult MRI-detected newly diagnosed breast cancer analysed by comparing machine learning models with a logistic regression model.

PURPOSE: To compare machine learning (ML) models with logistic regression model in order to identify the optimal factors associated with mammography-occult (i.e. false-negative mammographic findings) magnetic resonance imaging (MRI)-detected newly diagnosed breast cancer (BC). MATERIAL AND METHODS: The present single-centre retrospective study included consecutive women with BC who underwent mammography and MRI (no more than 45 days apart) for breast cancer between January 2018 and May 2023. Various ML algorithms and binary logistic regression analysis were utilized to extract features linked to mammography-occult BC. These features were subsequently employed to create different models. The predictive value of these models was assessed using receiver operating characteristic curve analysis. RESULTS: This study included 1957 malignant lesions from 1914 patients, with an average age of 51.64 ± 9.92 years and a range of 20-86 years. Among these lesions, there were 485 mammography-occult BCs. The optimal features of mammography-occult BC included calcification status, tumour size, mammographic density, age, lesion enhancement type on MRI, and histological type. Among the different ML models (ANN, L1-LR, RF, and SVM) and the LR-based combined model, the ANN model with RF features was found to be the optimal model. It demonstrated the best discriminative performance in predicting mammography false- negative findings, with an AUC of 0.912, an accuracy of 86.90%, a sensitivity of 85.85%, and a specificity of 84.18%. CONCLUSION: Mammography-occult MRI-detected breast cancers have features that should be considered when performing breast MRI to improve the detection rate for breast cancer and aid in clinician management.

Retrospective analysis of negative cytology results correlated with a positive high-risk in the human papillomavirus result and subsequent results of patients over a period of three years.

This research paper evaluates the efficacy of co-testing in precluding cervical cancer, with a particular focus on distinguishable outcomes of the human papillomavirus (HPV) vs. cytology tests. A retrospective review of 5948 patients, who tested positive for high-risk HPV but showed negative cytologic findings, revealed that 15.006% tested positive in subsequent screenings. A comparative analysis of various commercial HPV tests highlighted the precision of mRNA-based HPV testing by Aptima (Hologic) in reducing the likelihood of false-negative cytology. The paper challenges the conviction that a negative cytology alone suffices advocating for a condensed testing interval in instances of positive HPV outcomes, thereby facilitating earlier intervention and optimal preventive care. These findings unveil an exigency for reconsidering preventive strategies based on test outcomes.

[Defining sensitivity and specificity for quality control of organized cancer screening using Prefectural Cancer Registry data in Japan].

Objective　To decrease cancer mortality by implementing cancer screening programs, rigorous quality control measures that utilize standardized indicators are imperative. In Japan, although each municipality performing cancer screening programs implements quality control for their programs using the checklist authorized by the Ministry of Health, Labour and Welfare, compliance with all the items listed is not possible because calculating sensitivity and specificity using cancer registry data is difficult under these circumstances. This report elucidates the methodology for calculating indicators, including sensitivity and specificity, by delineating the parameters of false-negative cases within population-based cancer screening programs in Japan. Furthermore, the inherent challenges associated with ensuring the quality control of cancer screening procedures are expounded upon in this report.Method　Data from the Prefectural Cancer Registry of Japan and cancer screening records compiled by municipalities were used to differentiate true-positive, true-negative, false-positive, and false-negative cases based on the combination of screening test outcomes and subsequent cancer incidence.Results　A false-negative case was defined as an examinee who received a cancer diagnosis within one year after undergoing the screening test, notwithstanding the negative judgment of the cancer screening decision. The duration for judgment of true-positive, true-negative, and false-negative cases was also extended to one year. Cancer identification after cancer screening was ascertained using data from the Prefectural Cancer Registry, ensuring uniform categorization of the four cases. Subsequently, sensitivity and specificity values were calculated for municipalities conducting cancer screening programs.Conclusion　Sensitivity and specificity are indispensable metrics for the inherent quality control of cancer screening because these parameters directly assess the efficacy of screening tests. The anticipated increase in the number of municipalities engaged in comprehensive quality control of cancer screening in Japan is poised to enhance the efficiency of cancer control policies. This augmentation will be accomplished through the meticulous utilization of the sensitivity and specificity values elucidated in the present report. The forthcoming challenges involve the proliferation of medical institutes reporting their adherence to the checklist stipulated by the National Cancer Center of Japan and the widespread dissemination of fundamental knowledge pertaining to cancer screening.

Method for detecting rare differences between two LC-MS runs.

LC-MS based multi-attribute methods (MAM) have drawn substantial attention due to their capability of simultaneously monitoring a large number of quality attributes of a biopharmaceutical product. For successful implementation of MAM, it is usually considered a requirement that the method is capable of detecting any new or missing peaks in the sample when compared to a control. Comparing a sample to a control for rare differences is also commonly practiced in many fields for investigational purpose. Because MS signal variability differs greatly between signals of different intensities, this type of comparison is often challenging, especially when the comparison is made without enough replicates. In this report we describe a statistical method for detecting rare differences between two very similar samples without replicate analyses. The method assumes that an overwhelming majority of components have equivalent abundance between the two samples, and signals with similar intensities have similar relative variability. By analyzing several monoclonal antibody peptide mapping datasets, we demonstrated that the method is suitable for new-peak detection for MAM as well as for other applications when rare differences between two samples need to be detected. The method greatly reduced false positive rate without a significant increase of false negative rate.

Real-time quaking-induced conversion assays for prions: Applying a sensitive but imperfect test in clinical practice.

BACKGROUND AND PURPOSE: Real-time quaking-induced conversion (RT-QuIC) assays offer a sensitive and specific means for detection of prions, although false negative results are recognized in clinical practice. We profile the clinical, laboratory, and pathologic features associated with false negative RT-QuIC assays and extend these to frame the diagnostic approach to patients with suspected prion disease. METHODS: A total of 113 patients with probable or definite prion disease were assessed at Mayo Clinic (Rochester, MN; Jacksonville, FL; Scottsdale, AZ) or Washington University School of Medicine (Saint Louis, MO) from 2013 to 2021. RT-QuIC testing for prions was performed in cerebrospinal fluid (CSF) at the National Prion Disease Pathology Surveillance Center (Cleveland, OH). RESULTS: Initial RT-QuIC testing was negative in 13 of 113 patients (sensitivity = 88.5%). RT-QuIC negative patients were younger (median = 52.0 years vs. 66.1 years, p < 0.001). Other demographic and presenting features, and CSF cell count, protein, and glucose levels were similar in RT-QuIC negative and positive patients. Frequency of 14-3-3 positivity (4/13 vs. 77/94, p < 0.001) and median CSF total tau levels were lower in RT-QuIC negative patients (2517 vs. 4001 pg/mL, p = 0.020), and time from symptom onset to first presentation (153 vs. 47 days, p = 0.001) and symptomatic duration (710 vs. 148 days, p = 0.001) were longer. CONCLUSIONS: RT-QuIC is a sensitive yet imperfect measure necessitating incorporation of other test results when evaluating patients with suspected prion disease. Patients with negative RT-QuIC had lower markers of neuronal damage (CSF total tau and protein 14-3-3) and longer symptomatic duration of disease, suggesting that false negative RT-QuIC testing associates with a more indolent course.

Prenatal detection of congenital heart disease at 12-13 gestational weeks: detailed analysis of false-negative cases.

OBJECTIVES: To report on the early detection of congenital heart disease (CHD) in low- and high-risk populations managed at our hospital; and perform a detailed analysis of false-negative diagnoses, in order to derive possible recommendations on how to reduce their incidence. METHODS: This was a retrospective observational study analyzing cases which underwent an ultrasound examination at the end of the first trimester at the Fetal Medicine and Surgery Unit of Gaslini Children's Hospital, Genoa, Italy, in the period January 2015 to December 2021. The study population included both low-risk pregnancies that underwent standard first-trimester combined screening and high-risk ones referred to our unit because of a positive combined test or suspicion of fetal anomalies raised in a regional community hospital. For each case, the following variables were retrieved and analyzed: number of fetuses, maternal body mass index, gestational age at first-trimester screening, whether the pregnancy was low or high risk, nuchal translucency thickness (normal or > 99th  centile), type of CHD, associated extracardiac anomalies, karyotype and pregnancy outcome. For low-risk pregnancies, suspicion of CHD was also recorded. In low-risk cases, sonographic cardiac screening comprised evaluation of the four-chamber view (grayscale and color/power Doppler) and three-vessel-and-trachea view (color/power Doppler). High-risk cases underwent early fetal echocardiography. False-negative cases were categorized according to likely cause of the missed diagnosis, as follows: human factor; technical factor; acoustic-window factor. RESULTS: Gestational age at ultrasound ranged from 12 + 0 to 13 + 6 weeks (crown-rump length (CRL), 50.1-84.0 mm) in the low-risk group and from 11 + 5 to 13 + 6 weeks (CRL, 45.1-84.0 mm) in the high-risk group. Over the 7-year study period, 7080 pregnancies were evaluated in the first trimester. Of these, 6879 (7167 fetuses) were low-risk and 201 were high-risk cases. In the low-risk group, there were 30 fetuses with CHD (including 15 major and 15 minor CHD), yielding a prevalence of 4.2/1000 (2.1/1000 for major CHD). Nine of the 30 CHD cases were suspected at screening ultrasound (7/15 major CHD). Excluding cases in which the CHD would not be expected to be associated with a modification of the screening views and would therefore not be detectable on screening ultrasound, 7/12 cases of major CHD were detected, corresponding to a sensitivity of 58.3%. Among the 201 high-risk cases, there were 46 fetuses with CHD (including 44 major and two minor CHD), of which 43 were detected, corresponding to a sensitivity for early fetal echocardiography of 93.5%, or 97.7% if the two cases that were unlikely to be detectable on first-trimester screening were excluded. Analysis of the 11 (of 24) false-negative cases that would be expected to be picked up on screening views revealed that human error (image interpretation and/or scanning approach) was involved in all 11 cases and technical factors (excessive color priority (color-balance function) and/or incorrect plane alignment) were present in two. There was impairment of the acoustic window (associated with maternal obesity and/or twin gestation) as a cofactor in five of the 11 cases. CONCLUSIONS: The sensitivity for detection of major CHD of early cardiac screening in low-risk pregnancy is under 60%, partly due to the natural history of CHD and, it seems, partly relating to human error and technical issues with image quality. Factors associated with false-negative diagnoses may be categorized into three types: human error, technical factors and acoustic-window impairment. We recommend: appropriate assessment with fetal posterior spine; that sufficient time is spent on assessment of the fetal situs; and that color/power Doppler settings are adapted to the individual case. A lower threshold for referring doubtful cases for early fetal echocardiography should be adopted in cases of maternal obesity and in twin gestation. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Cystic fibrosis and CFTR-related disorder with electrolyte imbalance at diagnosis: clinical features and outcome in an Italian cohort.

There is limited information available on the clinical data, sweat test trends, and outcomes of individuals with cystic fibrosis (CF) who present with an isolated episode of hypoelectrolytemia with metabolic alkalosis (HMA). This study describes a cohort of Italian individuals with HMA as presenting symptom. The study is a retrospective multicenter analysis of individuals who presented with HMA as an initial symptom and was followed at 8 Italian CF Centers, from March 1988 to March 2022. Demographic, clinical, microbiological, biochemical, and genetic data were extracted from local health records. Ninety-three individuals were enrolled in the study. At first evaluation, 82 (88.2%) were diagnosed with CF, and 11 received a CFTR-Related Disorder (CFTR-RD) diagnostic label. Twenty-three (85.1%) out of the 27 subjects who underwent CF neonatal screening (NBS) resulted falsely negative. After a mean observational period of 11.5 years, most of subjects had a mild pulmonary phenotype, pancreatic sufficiency, and rarely CF-related complications. Four CFTR-RD changed to a CF diagnosis during the study period, resulting in 86 (92.4%) subjects classified as CF. CONCLUSIONS:  Most CF patients presenting with isolated HMA have a mild course of disease and rarely CF-related complications. WHAT IS KNOWN: • Isolated episode of hypoelectrolytemia with metabolic alkalosis is a well-known onset symptom of Cystic Fibrosis in infancy. • There is limited information available on the clinical data and outcomes of individuals with Cystic Fibrosis who present with electrolyte imbalance at diagnosis. WHAT IS NEW: • Most patients with Cystic Fibrosis presenting with isolated hypoelectrolytemia and metabolic alkalosis have a mild course of disease and rarely CF-related complications. • Electrolyte imbalance at diagnosis of Cystic Fibrosis is a common symptom in children not screened for CF at birth, or in those who received a false negative result from newborn screening.

Interpreting frequentist hypothesis tests: insights from Bayesian inference.

Randomized controlled trials are one of the best ways of quantifying the effectiveness of medical interventions. Therefore, when the authors of a randomized superiority trial report that differences in the primary outcome between the intervention group and the control group are "significant" (i.e., P ≤ 0.05), we might assume that the intervention has an effect on the outcome. Similarly, when differences between the groups are "not significant," we might assume that the intervention does not have an effect on the outcome. Nevertheless, both assumptions are frequently incorrect.In this article, we explore the relationship that exists between real treatment effects and declarations of statistical significance based on P values and confidence intervals. We explain why, in some circumstances, the chance an intervention is ineffective when P ≤ 0.05 exceeds 25% and the chance an intervention is effective when P > 0.05 exceeds 50%.Over the last decade, there has been increasing interest in Bayesian methods as an alternative to frequentist hypothesis testing. We provide a robust but nontechnical introduction to Bayesian inference and explain why a Bayesian posterior distribution overcomes many of the problems associated with frequentist hypothesis testing.Notwithstanding the current interest in Bayesian methods, frequentist hypothesis testing remains the default method for statistical inference in medical research. Therefore, we propose an interim solution to the "significance problem" based on simplified Bayesian metrics (e.g., Bayes factor, false positive risk) that can be reported along with traditional P values and confidence intervals. We calculate these metrics for four well-known multicentre trials. We provide links to online calculators so readers can easily estimate these metrics for published trials. In this way, we hope decisions on incorporating the results of randomized trials into clinical practice can be enhanced, minimizing the chance that useful treatments are discarded or that ineffective treatments are adopted.

RéSUMé: Les études randomisées contrôlées constituent l'un des meilleurs moyens de quantifier l'efficacité des interventions médicales. Par conséquent, lorsque les autrices et auteurs d'une étude randomisée superiorité signalent que les différences dans le critère d'évaluation principal entre le groupe d'intervention et le groupe témoin sont « significatives ¼ (c.-à-d. P ≤ 0,05), nous pourrions supposer que l'intervention a un effet sur le critère d'évaluation. De même, lorsque les différences entre les groupes ne sont « pas significatives ¼, nous pourrions supposer que l'intervention n'a pas d'effet sur le critère d'évaluation. Pourtant, ces deux hypothèses s'avèrent souvent incorrectes.Dans cet article, nous explorons la relation qui existe entre les effets réels d'un traitement et les déclarations de signification statistique fondées sur les valeurs P et les intervalles de confiance. Nous expliquons pourquoi, dans certaines circonstances, la probabilité qu'une intervention soit inefficace lorsque P ≤ 0,05 dépasse 25 % et la probabilité qu'une intervention soit efficace lorsque P > 0,05 dépasse 50 %.Au cours de la dernière décennie, nous avons assisté à un intérêt croissant pour les méthodes bayésiennes comme alternative aux tests d'hypothèses fréquentistes. Nous proposons une introduction robuste mais non technique à l'inférence bayésienne et expliquons pourquoi une distribution postérieure bayésienne surmonte bon nombre des problèmes associés aux tests d'hypothèses fréquentistes.Malgré l'intérêt actuel pour les méthodes bayésiennes, les tests d'hypothèses fréquentistes restent la méthode par défaut pour l'inférence statistique en recherche médicale. Par conséquent, nous proposons une solution provisoire au « problème de signification ¼ basée sur des mesures bayésiennes simplifiées (par exemple, facteur de Bayes, risque de faux positifs) qui peuvent être rapportées en même temps que les mesures traditionnelles des valeurs P et des intervalles de confiance. Nous calculons ces paramètres pour quatre études multicentriques bien connues. Nous fournissons des liens vers des calculatrices en ligne afin que les lectrices et lecteurs puissent facilement estimer ces mesures pour les études publiées. De cette façon, nous espérons que les décisions sur l'intégration des résultats des études randomisées dans la pratique clinique pourront être améliorées, minimisant ainsi le risque que des traitements utiles soient rejetés ou que des traitements inefficaces soient adoptés.

Comprehensive genomic analysis of the potential limitations of several published PCR primers targeting prfA-virulence gene cluster in Listeria species.

Polymerase chain reaction (PCR) is commonly used to detect Listeria monocytogenes, foodborne pathogen. This study conducted in silico genomic analysis to investigate the specificity and binding efficacy of four published pairs of PCR primers targeting Listeria prfA-virulence gene cluster (pVGC) based on Listeria sequences available. We first performed comprehensive genomic analyses of the pVGC, the main pathogenicity island in Listeria spp. In total, 2961 prfA, 642 plcB, 629 mpl, and 1181 hlyA gene sequences were retrieved from the NCBI database. Multiple sequence alignments and phylogenetic trees were generated using unique (non-identical or not-shared) sequences of each represented genes, targeting four pairs of PCR primers published previously, namely 202 prfA, 82 plcB, 150 mpl, and 176 hlyA unique gene sequences. Only the hlyA gene showed strong (over 94%) primer mapping results, while prfA, plcB, and mpl genes showed weak (<50%) matching results. In addition, nucleotide variations were observed at the 3' end of the primers, indicating non-binding to the targets could potentially cause false-negative results. Thus, we propose designing degenerate primers or multiple PCR primers based on as many isolates as possible to minimize the false-negative risk and reach the aim of low tolerable limits of detection.

Ultrasonographic and cytological characterization of ultrasound-guided fine-needle aspiration cytology of cervical lymph nodes for false-negative and false-positive diagnosis.

OBJECTIVES: The primary goal of this study was to examine the ultrasound and cytological characteristics of inconsistent cases (false negatives and false positives)of ultrasound-guided fine-needle aspiration cytology (US-FNAC) of cervical lymph nodes, to investigate factors influencing the diagnostic accuracy of fine-needle aspiration, and to improve diagnostic efficiency. METHODS: The results of US and FNAC of cervical lymph nodes in 562 cases treated at our institution from February 2019 to June 2021 were retrospectively analyzed. FNAC cytology results were compared with the final diagnostic results (242 surgical resections/core-needle biopsy, 320 cases followed up for more than 1 year), and the final diagnostic results were taken as the gold standard, and the ultrasound features and clinicopathology-related features were systematically retrospectively analyzed in cases of inconsistency. RESULTS: The overall diagnostic accuracy of US-FNAC for cervical lymph nodes was 94.9%, with a false-negative rate of 6.7% and a false-positive rate of 3.8%. Analyzing the cases, sampling error due to factors associated with ultrasound features, such as larger, more numerous nodes, non-solid, hypoechoic, inhomogeneous, and increased vascularity are the main causes of false-negative diagnosis, while smaller nodules, overlapping cytologic patterns, and overinterpretation by pathologists are associated with false-positive FNAC results. CONCLUSIONS: Proper interpretation of cytomorphologic and ultrasound features can improve diagnostic accuracy, and diagnostic misdiagnosis should be carefully observed, the identification of both features should be enhanced to reduce interpretation errors and sampling errors and to reduce the rate of misdiagnosis and missed diagnoses in fine needle aspiration of lymph nodes.

Parental Psychological Distress of Missed Diagnosis of Down Syndrome at Antenatal Screening: A Rare, but Still Real Occurrence - A Case Report and Review of Literature.

INTRODUCTION: Prenatal screening programs are important components for pregnant women care and are often linked with grief and shock based on gestational age or the diagnosis. Lower/no sensitivity is also associated with these screening programs leading to providing false-negative outputs. CASE PRESENTATION: Present work shows a case of missed antenatal diagnosis of Down syndrome and its persistant medical and psychological impact on the family members. We have also discussed the relevant economic and medical-legal issues related to the context and aimed to maintain an adequate awareness among healthcare to discuss properly these investigations (difference between screening and diagnostic testing), their possible outcome (chances of false results) and enabled the pregnant women/couple to take informed decision on early pregnancy. CONCLUSION: These programs are considered as routine clinical practice in many countries from last few years and are necessary to assess the pros and cons of these programs. One of the prime cons involves the likeliness of obtaining a false-negative result due to lack of 100% sensitivity and specificity.

Using Alzheimer's disease blood tests to accelerate clinical trial enrollment.

INTRODUCTION: Screening potential participants in Alzheimer's disease (AD) clinical trials with amyloid positron emission tomography (PET) is often time consuming and expensive. METHODS: A web-based application was developed to model the time and financial cost of screening for AD clinical trials. Four screening approaches were compared; three approaches included an AD blood test at different stages of the screening process. RESULTS: The traditional screening approach using only amyloid PET was the most time consuming and expensive. Incorporating an AD blood test at any point in the screening process decreased both the time and financial cost of trial enrollment. Improvements in AD blood test accuracy over currently available tests only marginally increased savings. Use of a high specificity cut-off may improve the feasibility of screening with only an AD blood test. DISCUSSION: Incorporating AD blood tests into screening for AD clinical trials may reduce the time and financial cost of enrollment. HIGHLIGHTS: The time and cost of enrolling participants in Alzheimer's disease (AD) clinical trials were modeled. A web-based application was developed to enable evaluation of key parameters. AD blood tests may decrease the time and financial cost of clinical trial enrollment. Improvements in AD blood test accuracy only marginally increased savings. Use of a high specificity cut-off may enable screening with only an AD blood test.

Emergent multipath COVID-19 specimen collection problem with green corridor through variable length GA.

The COVID-19 pandemic has spread worldwide exponentially. Typically, for testing, a provincial main government hospital cum testing center collects patients' specimens from remote health centers in the minimum possible time, satisfying the 'false negativity' constraint of the first collected specimen. With infrastructural developments throughout the world, multiple paths are available for transportation between two cities. Currently, the 'green corridor' is used for the transportation of human organs to be implanted, travel of VIPs, etc., in the minimum possible time. Taking these facts in consideration, for the first time, a green corridor system is suggested to provide a transportation pathway from small hospitals and urban/rural health centers to the testing center with COVID-19 specimens such as blood, nasal and throat swabs, and viral RNA, within the first collected specimen's life period. As health centers are located in different places, appropriate routing plans are needed for visiting them in the minimum possible time. A problem arises if this routing time exceeds the 'false negativity' of the first collected specimen. Thus, multipath COVID-19 specimen collection problems (MPC-19SCPs) are mathematically formulated to be collected from all health centers, and optimum routing plans are obtained using fixed and variable length genetic algorithms (VLGAs) developed for this purpose. For the first time, green corridor systems are suggested to incorporate the centers. The objectives of the models are, subject to the 'false-negative" constraint, minimization of the system time (Model A) and the green corridor time without or with mutual cooperation among the minimum number of centers for the transfer of specimens (Models B and C, respectively). The developed algorithms are based on variable length chromosomes, probabilistic selection, comparison crossover and generation-dependent mutation. Some benchmark instances from TSPLIB are solved by VLGA and GA. The competitiveness of VLGA is established through ANOVA. The models are numerically demonstrated, and some conclusions are derived.

A ruptured thoracic aortic aneurysm and the difficulties of confirming syphilis.

A 43-year-old woman died suddenly and was found at PM to have a ruptured thoracic aortic aneurysm. The endothelial surface of the aorta showed a 'tree-bark' appearance. Histology of the aneurysm wall showed a patchy, mainly perivascular, plasma cell infiltrate. Multiple spirochete-like organisms were identified on T. pallidum IHC. However, PM syphilis serology (screen including rapid plasma reagin (RPR) and T. pallidum particle agglutination (TPPA)) on femoral blood was negative. PCR testing on FFPE aortic wall tissue was negative. Further history revealed routine antenatal syphilis screening tests had been negative, no known history or risk of exposure to syphilis or other treponemes. This case raises the possibility of false negative syphilis testing. While acknowledged in RPR testing, with the modern testing regime using multiple methods, the rate of false negative results is now thought to be markedly reduced, and false positive results are a much greater problem in clinical medicine. The most common cause of false negative results is early in primary infection before an immune response has been mounted and in those patients that are immunocompromised. False negative results are also more often seen in tertiary syphilis, as in this case. Newer testing methods which include 16S rRNA sequencing have become available and early discussion with a microbiologist would be recommended. Strong macroscopic and microscopic suggestion of syphilis as the cause of the aneurysm makes it necessary to include the possibility of infection in the Post Mortem Report to Coroner as this will have implications for her sexual partners and children.

[Recurrent atelectasis in an infant : about one case of false-negative newborn screening for cystic fibrosis]. / Atélectasie récidivante chez un nourrisson : à propos d'un cas de faux-négatif du dépistage néonatal pour la mucoviscidose.

In infants as well as in older children, persistent or recurrent atelectasis remains a classic indication for sweat testing, even if neonatal screening for cystic fibrosis has been considered normal. Atelectasis is a common complication of cystic fibrosis. Yet, it has rarely been reported in infants. In cystic fibrosis, chronic atelectasis worsens the prognosis, especially when involving a lower lobe. Therefore, early and effective intervention is required. Antibiotic therapy, intensive chest physiotherapy together with inhaled mucolytics often allow to relieve bronchial obstruction but bronchoscopy with local aspiration and Dornase alpha instillation is sometimes necessary. In a two-month-old infant, we describe here the first reported case of false-negative cystic fibrosis newborn screening in Belgium.

Chez le nourrisson comme chez l'enfant plus âgé, une atélectasie persistante ou récidivante reste une indication classique de test à la sueur, même si le dépistage néonatal de la mucoviscidose a été considéré comme normal. Rarement rapportées chez le nourrisson, les atélectasies sont une complication commune de la mucoviscidose. Dans cette affection, l'atélectasie chronique d'un territoire péjore le pronostic, en particulier si elle concerne un lobe inférieur. Une intervention précoce et efficace est donc requise. Antibiothérapie, kinésithérapie respiratoire intensive et recours aux fluidifiants par voie de nébulisation suffisent souvent à lever l'obstruction bronchique, mais une endoscopie avec aspiration locale et instillation de dornase alpha est parfois nécessaire. Chez un nourrisson de 2 mois, nous rapportons ici le premier cas de faux-négatif du programme belge de dépistage néonatal de la mucoviscidose.