Search

Background/aim: The severity and associated mortality of coronavirus disease 2019 (COVID-19) are higher in patients with thoracic cancer than in healthy populations and those with other cancer types. Here, we investigated real-world data on the incidence of COVID-19 and false-negative cases using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse-transcription polymerase chain reaction (rRT-PCR) testing in patients with thoracic cancer., Patients and Methods: We retrospectively reviewed patients with advanced thoracic cancer at the National Cancer Center Hospital between March 2020-May 2021. Blood samples were collected and evaluated for IgM and IgG antibodies specific for nucleocapsid (N) and spike (S) protein SARS-CoV-2 before and after rRT-PCR testing. False-negative cases were assessed based on anti-SARS-CoV-2 antibody levels before and after rRT-PCR testing., Results: A total of 2,107 patients with thoracic cancer were identified between March 2020 and May 2021, 7 (0.3%) of whom developed COVID-19. Among the 218 patients who underwent at least one rRT-PCR test because of suspected COVID-19 symptoms or as a screening test at our institute, the most common diagnosis was non-COVID-19 pneumonia (34.4%), followed by tumor fever (30.7%). Furthermore, of the 218 patients, 120 paired serum samples before and after rRT-PCR testing were available. Seroconversion was identified in all three patients with positive SARS-CoV-2 rRT-PCR results but was only observed in 1 out of the 117 patients who tested negative; the rate of false-negative cases was low (0.9%)., Conclusion: COVID-19 incidence among patients with advanced thoracic cancer was low during the early phase of the pandemic in Japan., (Copyright © 2023 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Biological monitoring programmes are increasingly relying upon large volumes of citizen-science data to improve the scope and spatial coverage of information, challenging the scientific community to develop design and model-based approaches to improve inference., Recent statistical models in ecology have been developed to accommodate false-negative errors, although current work points to false-positive errors as equally important sources of bias. This is of particular concern for the success of any monitoring programme given that rates as small as 3% could lead to the overestimation of the occurrence of rare events by as much as 50%, and even small false-positive rates can severely bias estimates of occurrence dynamics., We present an integrated, computationally efficient Bayesian hierarchical model to correct for false-positive and false-negative errors in detection/non-detection data. Our model combines independent, auxiliary data sources with field observations to improve the estimation of false-positive rates, when a subset of field observations cannot be validated a posteriori or assumed as perfect. We evaluated the performance of the model across a range of occurrence rates, false-positive and false-negative errors, and quantity of auxiliary data., The model performed well under all simulated scenarios, and we were able to identify critical auxiliary data characteristics which resulted in improved inference. We applied our false-positive model to a large-scale, citizen-science monitoring programme for anurans in the north-eastern United States, using auxiliary data from an experiment designed to estimate false-positive error rates. Not correcting for false-positive rates resulted in biased estimates of occupancy in 4 of the 10 anuran species we analysed, leading to an overestimation of the average number of occupied survey routes by as much as 70%., The framework we present for data collection and analysis is able to efficiently provide reliable inference for occurrence patterns using data from a citizen-science monitoring programme. However, our approach is applicable to data generated by any type of research and monitoring programme, independent of skill level or scale, when effort is placed on obtaining auxiliary information on false-positive rates. [ABSTRACT FROM AUTHOR]

Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are the current standards methods for the determination of tissue human epidermal growth factor receptor 2 (HER2) status in gastric cancer, as for breast cancer. However, HER2-positive gastric cancer occasionally exhibits heterogeneous tissue HER2 overexpression, raising concern regarding false-negative results in unresectable cases diagnosed by biopsy samples. Serum HER2, the concentration of the extracellular domain of HER2 protein shed into the bloodstream, has the potential to supplement the use of IHC or FISH to determine HER2 status. However, the clinical significance of serum HER2 has not been well studied in gastric cancer. The present study describes an illustrative case of metastatic gastric cancer initially diagnosed as HER2-negative (IHC score 1+). The patient exhibited an elevated serum HER2 level, which prompted a reevaluation of the tissue by IHC, using an alternative antibody, and FISH; re-biopsy analyses confirmed the case as HER2-positive, and trastuzumab was subsequently added to the combination chemotherapy with capecitabine and cisplatin. Serum HER2 may aid in avoiding false-negative diagnoses of HER2 gastric cancer. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this systematic review is to provide a discussion of the evidence supporting and negating the need for routine microbiological culture surveillance of flexible endoscopes. Methods: A medical librarian conducted a systematic search of the Ovid MEDLINE, EBSCO CINAHL, and Scopus databases as well as the Ovid Cochrane Database of Systematic Reviews for a national guideline on flexible endoscope processing to be developed by the Association of periOperative Registered Nurses (AORN). Search results were limited to literature published in English from 1994 through 2014. The author and the librarian also identified relevant guidelines and guidance from government agencies, professional organizations, and standards-setting bodies. Results: Routine microbiological surveillance culturing is supported in the literature as an effective method for monitoring [he effectiveness and quality of processing, reinforcing best practices, evaluating the effectiveness of corrective interventions, and detecting endoscopes requiring service.1-13; however, there is also evidence to show that surveillance cultures may be ineffective as a method for preventing transmission of infection from flexible endoscopes.13-18 Conclusions: A multidisciplinary team that includes infection preventionists, endoscopists, laboratory personnel, risk managers, and other involved individuals should evaluate the need for implementing a program of regular microbiological culture surveillance, establishing the methods and frequencies for culturing, and determining the benchmarks for microbial levels in flexible endoscope cultures. [ABSTRACT FROM AUTHOR]

Background and objective It is difficult to verify the bacteriological diagnosis of M ycobacterium avium complex ( MAC) infection. The anti-glycopeptidolipid ( GPL)-core IgA antibody test was recently developed as a diagnostic method for MAC pulmonary disease. Only a few studies evaluate its clinical efficacy. We conducted retrospective evaluations of clinical characteristics of patients suspected of MAC infection to explore the usefulness of the anti- GPL-core IgA antibody test. Methods We retrospectively evaluated 296 patients who were suspected to have MAC infection and underwent anti- GPL-core IgA antibody test between March 2013 and July 2014 in Jikei University hospital. Results A total of 29 patients were diagnosed with 'definite MAC' based on the American Thoracic Society ( ATS) criteria with multiple identifications of MAC. On the other hand, 106 patients were diagnosed with other pulmonary diseases than MAC. The sensitivity and specificity of anti- GPL-core IgA antibody test for MAC diagnosis were 58.6% and 98.1%, respectively. The definite MAC group showed no significant differences in strains, treatment history or number of segments involved. The duration of MAC disease in the positive-antibody group was significantly longer than in the negative-antibody group ( P = 0.046). A significant increase in the false-negative rate was observed in patients with malignant disease ( P = 0.029). Conclusions The anti- GPL-core IgA antibody test demonstrated high sensitivity and specificity for the diagnosis of MAC infection especially in patients without malignant diseases. [ABSTRACT FROM AUTHOR]

Highlights • A positive result of HIV antibody by serological test. • An undetectable HIV-1 RNA by the CAP/CTM v2.0 assay in the absence of ARV. • A low or even undetectable HIV-1 viral load may be a false-negative result. • Repeating serological confirmatory test (WB) is essential. Abstract Human immunodeficiency virus (HIV)/AIDS is a major public health problem worldwide. Here we report the case of a patient with positive HIV-1 serology and negative result of The COBAS AmpliPrep/COBAS Taqman HIV-1 Test version 2.0 (CAP/CTM v2.0) assay (Roche Diagnostics) for HIV-1 RNA quantification in the absence of antiretroviral therapy (ARV). Considering the HIV contact history and repeating serological confirmatory test is essential before considering a low or even undetectable HIV-1 viral load to be a false-negative result. [ABSTRACT FROM AUTHOR]

Background: Interleukin-27 (IL-27) has been proposed to be useful for diagnosing tuberculous pleural effusion (TPE). Adenosine deaminase (ADA) has been long used for the same purpose. The aim of this study was to compare the performance of IL-27, ADA, and their product (IL-27 · ADA) in the diagnosis of TPE. Methods: Pleural fluid samples from patients with exudative pleural effusions were assessed for IL-27 and ADA levels. Receiver operating characteristic (ROC) curves were constructed to compare the overall diagnostic accuracy of IL-27, ADA, and IL-27 · ADA. Curves of false-positive (FPR) and false-negative (FNR) rates as a function of TPE prevalence were also constructed, and mean rates of false results in low (1-10%), intermediate (11-40%), and high (41-70%) prevalences were estimated to evaluate the ability of the three markers in ruling in or ruling out TPE. Results: We studied 121 exudates. IL-27 and ADA were higher in TPEs compared with non-TPEs and they presented similar accuracies for the diagnosis of TPE. The product of IL-27 and ADA (IL-27 · ADA) was more accurate than ADA for the same purpose. IL-27 and IL-27 · ADA presented the lowest overall FPR and FNR, respectively. The FPR of IL-27, ADA and IL-27 · ADA was > 9%, even in high prevalence settings. Although their FNR was < 2% in low prevalence settings, only IL-27 · ADA exhibited sufficiently low FNR (< 1%) in intermediate and high prevalences. Conclusions: ADA, IL-27, and IL-27 · ADA cannot reliably 'rule in' TPE in any prevalence setting. TPE can be 'ruled out' by each of the biomarkers in low prevalence settings. In intermediate and high prevalence settings, IL-27 · ADA is a reliable 'rule out' test in the diagnostic approach to TPEs. [ABSTRACT FROM AUTHOR]

Determining pregnancy status is vital in the approach to adolescent females with abdominal pain or vaginal bleeding. The prognosis of extrauterine pregnancies and gestational trophoblastic disease depends greatly on the ability to make an early diagnosis. Urine qualitative β human chorionic gonadotropin (β-hCG) tests are routinely used in emergency departments for pregnancy screening. However, point-of-care testing can be misleading in molar or late first-term pregnancies when β-hCG levels are extremely high. We report a case of an adolescent female presenting with a molar pregnancy in which point-of-care pregnancy testing was falsely negative due to the "high-dose hook effect." The "hook effect" affects almost all current qualitative assays and highlights the dangers of reliance on a single laboratory test. [ABSTRACT FROM AUTHOR]

Summary Objectives To investigate the risk factors for false-negative T-SPOT. TB results in patients with pulmonary TB (PTB) and extra-pulmonary TB (EPTB). Methods Patients with suspected TB who underwent valid T-SPOT. TB tests were prospectively enrolled at Beijing Chest Hospital between November 2012 and November 2013. Basic characters and clinical laboratory findings were compared between true-positive and false-negative T-SPOT. TB groups. Results Of 1928 suspected TB patients, 774 (530 PTB and 244 EPTB) microbiologically/histopathogenically-confirmed patients (636 culture-confirmed) were analyzed. Forty-six PTB patients (8.7%) and 32 EPTB patients (13.1%) had negative T-SPOT. TB results. Multivariate analysis showed that increased age [odds radio (OR) 2.26, 95% confidence interval (CI) 1.11–4.58], over-weight (BMI ≥ 25 kg/m 2 , OR 2.43, 95% CI 1.05–5.63), and a longer period of illness before hospitalization (>6 months, OR 2.46, 95% CI 1.24–4.92) were independent risk factors for false-negative T-SPOT. TB results in PTB patients. In EPTB patients, increased age (OR 2.42, 95% CI 1.09–5.35) also showed an independent association with false-negative T-SPOT. TB results. Conclusion Careful interpretation of negative T-SPOT. TB results is necessary in older patients with suspected PTB or EPTB, and in PTB patients who are over-weight or have had longer periods of illness before hospitalization. [ABSTRACT FROM AUTHOR]

Failure to understand the risk of false-negative HIV test results during the window period results in anxiety. Patients typically want accurate test results as soon as possible while clinicians prefer to wait until the probability of a false-negative is virtually nil. This review summarizes the median window periods for third-generation antibody and fourth-generation HIV tests and provides the probability of a false-negative result for various days post-exposure. Data were extracted from published seroconversion panels. A 10-day eclipse period was used to estimate days from infection to first detection of HIV RNA. Median (interquartile range) days to seroconversion were calculated and probabilities of a false-negative result at various time periods post-exposure are reported. The median (interquartile range) window period for third-generation tests was 22 days (19–25) and 18 days (16–24) for fourth-generation tests. The probability of a false-negative result is 0.01 at 80 days’ post-exposure for third-generation tests and at 42 days for fourth-generation tests. The table of probabilities of falsely-negative HIV test results may be useful during pre- and post-test HIV counselling to inform co-decision making regarding the ideal time to test for HIV. [ABSTRACT FROM AUTHOR]

In the short 10 years following the introduction of non-invasive prenatal testing (NIPT), it has been adapted in many countries around the world as a standard screening test. In this review, this development was analyzed with a special focus on Germany. As a result, it can be stated that all known advantages of NIPT apart from "compensating for having no access to centers offering invasive diagnostics" are valid for Germany. In addition, following a review of the international literature, all documented issues with NIPT are also observed in Germany. However, the German Gene Diagnostics Act (GenDG) addresses a number of these issues, for example, the regulations by GenDG hamper induced abortions, based exclusively on an abnormal NIPT result. At the same time, GenDG has created new problems, as a possible collusion between the "right not to know with regard to parts of the examination result" may occur, or that the sex of the fetus must not be reported to the pregnant woman before the 12th week of gestation. Main conclusions drawn are that appropriate training and the continuing education of the physicians providing NIPT-related counseling are needed, as well as the provision of balanced and comprehensive information for the pregnant woman or the couple that is imperative.

It has been found that patients recovered from COVID 19 may still test Reverse Transcriptase- Polymerase Chain Reaction (RT- PCR) positive without being infectious; the reasons are unclear. The occurrence of false-negative results of RT- PCR interferes with a proper diagnosis. The objectives of that work were to determine factors associated with persistently detectable SARS-CoV-2 RNA among recovered hospitalized patients and to determine the incidence of false-negative RT-PCR results and associated factors. Relevant data were collected from 482 COVID 19 patients hospitalized in six referral centers from four countries. The median duration of RT- PCR conversion to negative was 20 days. Out of 482 studied patients, 8.7% tested positive after more than four weeks and were considered prolonged convertors. Binary logistic regression analysis revealed headache as an independent risk factor for short conversion time while fever, hypertension, chronic obstructive pulmonary disease, lymphopenia, elevated erythrocyte sedimentation rate, and the number of lobes affected, and bilateralism were found to be independent risk factors for prolonged positivity. Eighteen patients had initial negative results then turned positive after 24–48 h. Associated factors and outcomes were identified. Identifying patients with a high likelihood of COVID-19 despite a negative RT-PCR is critical for effective clinical care. However, patient isolation resumption depending on positive RT-PCR despite clinical and radiological recovery is an overrating that greatly burdens the health sector. [ABSTRACT FROM AUTHOR]

BACKGROUND Fine-needle aspiration (FNA) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules, but the false-negative rates are generally reported to be between 3.6% and 10.2%. To lower the overall incidence of this false-negative testing, new reporting systems encourage the molecular testing of thyroid nodules. However, to the authors' knowledge, the role of molecular testing in false-negative FNA has not yet been evaluated. METHODS In total, 1347 consecutive papillary thyroid carcinomas (PTCs) with both cytological and histological diagnoses were collected from the same center. A blinded revision of the false-negative cases was performed. An analysis of the BRAF and Ras genes in the false-negative cases was then performed. RESULTS The false-negative rate at the time of primary FNA diagnosis was 4.8% (65 of 1347 cases). False-negative cases were 15 follicular variant PTCs, 2 classical variant, and 1 solid variant that lacked peculiar PTC cytomorphological features. Adequate cellular material for molecular analysis was available only in 54 of the 65 false-negative cases. Mutations were found in 6 cases (11%), and Ras alterations were present in 16 cases (29.6%). The addition of molecular analysis decreased the false-negative rate to 0.4% (5 of 1347 cases). CONCLUSIONS The results of the current study confirm the feasibility of BRAF and Ras analysis in routine FNA. However, when the false-negative FNA rate is low, the cost-benefit analysis of the detection of BRAF and Ras mutations should be carefully evaluated. Consequently, the authors suggest that preoperative molecular assessment could be helpful for benign nodules, but only in the presence of clinical suspicion of malignancy. Cancer (Cancer Cytopathol) 2014;122:751-759. © 2014 American Cancer Society. [ABSTRACT FROM AUTHOR]

Clinical studies examining performance of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in identifying excessive alcohol consumption have been primarily conducted in male populations. An impact of hair cosmetics in producing both false-negative EtG results and false-positive FAEE results has been demonstrated, suggesting a possible bias in female populations. This study evaluates FAEE-positive hair samples (>0.50 ng/mg) from n = 199 female and n = 73 male subjects for EtG. Higher FAEE/EtG concordance was observed amongst male over female subjects. Performance of multiple proposed EtG cut-off levels were assessed; amongst female samples, FAEE/EtG concordance was 36.2% (30 pg/mg), 36.7% (27 pg/mg), and 43.7% (20 pg/mg). Non-coloured hair demonstrated a two-fold increase in concordance (41.8 v. 20.8%) over coloured hair in the female cohort. FAEE levels did not differ between male and female subjects; however they were lower in coloured samples (p = 0.046). EtG was lower in female subjects (p = 0.019) and coloured samples (p = 0.026). A total of n = 111 female samples were discordant. Amongst discordant samples (EtG-negative), 26% had evidence of recent alcohol use including consultation histories (n = 20) and detectable cocaethylene (n = 9); 29% of discordant samples were coloured. False-negative risk with ethyl glucuronide analysis in females was mediated by cosmetic colouring. These findings suggest that combined analysis of FAEE and EtG is optimal when assessing a female population and an EtG cut-off of 20 pg/mg is warranted when using combined analysis. While concordant FAEE/EtG-positive findings constitute clear evidence, discordant FAEE/EtG findings should still be considered suggestive evidence of chronic excessive alcohol consumption. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Many factors affecting satellitism tests are unclear, and it is difficult to avoid misidentification, even if the medium is properly selected. We investigated the factors causing false-positive results for Haemophilus influenzae and false-negative results for Haemophilus parainfluenzae in the satellitism tests using Staphylococcus aureus as the source of nicotinamide adenine dinucleotide (NAD). H. influenzae (four reference strains and 47 clinical isolates), H. parainfluenzae (two reference strains and 67 clinical isolates), four different media, and two strains of S. aureus revived on two different media were used in this study. The type of medium used to revive S. aureus was the most common factor causing false-positive results for H. influenzae , followed by different strains of S. aureus and the type of medium used for the experiment. The production of false-negative results for H. parainfluenzae was only related to the medium used in the experiment. To improve the accuracy of the tests in routine laboratories, using S. aureus as the source of NAD, tryptic soy agar, and S. aureus (ATCC 25923) revived on nutrient agar should be adopted. • Scientifically operating satellitism tests is important in routine laboratories. • Types of medium used to revive S. aureus have the most impact on Haemophilus influenzae. • Haemophilus parainfluenzae is only affected by the medium used in the experiment. • TSA and S. aureus (ATCC 25923) revived on nutrient agar should be adopted. [ABSTRACT FROM AUTHOR]

Objectives: This study sought to investigate the clinical and imaging characteristics associated with diagnostic inaccuracy of computed tomography angiography (CTA) for detecting obstructive coronary artery disease (CAD) defined by quantitative coronary angiography (QCA). Background: Although diagnostic performance metrics of CTA have been reported, there are sparse data on predictors of diagnostic inaccuracy by CTA. Methods: The clinical characteristics of 291 patients (mean age: 59 ± 10 years; female: 25.8%) enrolled in the multicenter CorE-64 (Coronary Artery Evaluation Using 64-Row Multi-detector Computed Tomography Angiography) study were examined. Pre-defined CTA segment-level characteristics of all true-positive (N = 237), false-positive (N = 115), false-negative (FN) (N = 159), and a random subset of true-negative segments (N = 511) for ≥50% stenosis with QCA as the reference standard were blindly abstracted in a central core laboratory. Factors independently associated with corresponding levels of CTA diagnostic inaccuracies on a patient level and coronary artery segment level were determined using multivariable logistic regression models and generalized estimating equations, respectively. Results: An Agatston calcium score of ≥1 per patient (odds ratio [OR]: 5.2; 95% confidence interval [CI]: 1.1 to 24.6) and the presence of within-segment calcification (OR: 10.2; 95% CI: 5.2 to 19.8) predicted false-positive diagnoses. Conversely, absence of within-segment calcification was an independent predictor of an FN diagnosis (OR: 2.0; 95% CI: 1.2 to 3.5). Prior percutaneous revascularization was independently associated with patient-level misdiagnosis of obstructive CAD (OR: 4.2; 95% CI: 1.6 to 11.2). Specific segment characteristics on CTA, notably segment tortuosity (OR: 3.5; 95% CI: 2.4 to 5.1), smaller luminal caliber (OR: 0.48; 95% CI: 0.36 to 0.63 per 1-mm increment), and juxta-arterial vein conspicuity (OR: 2.1; 95% CI: 1.4 to 3.2), were independently associated with segment-level misdiagnoses. Attaining greater intraluminal contrast enhancement independently lowered the risk of an FN diagnosis (OR: 0.96; 95% CI: 0.94 to 0.99 per 10-Hounsfield unit increment). Conclusions: We identified clinical and readily discernible imaging characteristics on CTA predicting inaccurate CTA diagnosis of obstructive CAD defined by QCA. Knowledge and appropriate considerations of these features may improve the diagnostic accuracy in clinical CTA interpretation. (Diagnostic Accuracy of Multi-Detector Spiral Computed Tomography Angiography Using 64 Detectors [CORE-64]; NCT00738218) [Copyright &y& Elsevier]

BACKGROUND The diagnosis of pancreatic tumors is often complicated because of sampling and interpretive challenges. The current study was performed to determine the rates, types, and causes of diagnostic discrepancies. METHODS The authors retrospectively reviewed cytology cases from 2004 to 2010 using matched surgical resection cases as the gold standard. RESULTS A total of 733 cases were divided into 3 categories: 1) positive or suspicious (290 cases); 2) negative or atypical (403 cases); and 3) unsatisfactory (40 cases). Of these cases, 101 fine-needle aspiration (FNA) cases had matched surgical resections including 58 positive diagnoses, 39 negative diagnoses, and 4 unsatisfactory diagnoses. All 19 discrepant cases represented false-negative diagnoses without any false-positive cases noted, which included 2 cases with interpretive errors (10%) and 17 cases with sampling errors (90%). All matched cytology cases were divided into 5 subgroups based on the type of lesion or type of error and were analyzed for sensitivity and specificity. The sampling error rate in cystic lesions (8 of 24; 33%) was significantly higher than that in solid lesions (9 of 73; 12%). The false-negative rate in the interpretive error group (3%) was significantly lower than that in the sampling error group (23%). CONCLUSIONS The results of the current study confirm that pancreatic endoscopic ultrasound-guided FNA diagnosis has a very low false-positive rate but a relatively high false-negative rate using matched surgical resections as the gold standard. The major cause of a false-negative cytology diagnosis is sampling error and the rate of sampling error in cystic lesions is significantly higher than that in solid lesions. Cancer (Cancer Cytopathol) 2013;121:449-58. © 2013 American Cancer Society. [ABSTRACT FROM AUTHOR]

We treated a case that exhibited dissociation between blood flow in the transferred jejunum and the monitoring flap. The monitoring flap showed a false-negative, indicating blood flow to be favorable despite blood congestion in the transferred jejunum. The patient was a 69-year-old man. After tumor resection, reconstruction was performed with free jejunal transfer. Vascular anastomosis was performed on the jejunal artery and transverse cervical artery and on the jejunal vein (V1) and external jugular vein. After esophagus anastomosis, blood congestion was noted in the transferred jejunum. An engorged arcade vein (V2) was observed in the mesenterium on the transferred jejunum side. Therefore, it was anastomosed to the external jugular vein bifurcation. The first postoperative day, thrombus had formed in the vein (V2). The transferred jejunum side vein (V2) was re-anastomosed to the external jugular vein, and improved blood flow was observed in the transferred jejunum. Monitoring transferred jejunum blood flow with monitoring flap exteriorization appears to be a simple and highly reliable method. However, because the monitoring flap cannot directly evaluate transferred jejunum blood flow, blood flow obstruction can occur between the transferred jejunum and the true situation may not be reflected. [ABSTRACT FROM AUTHOR]

Background.The currently used patch test concentration for formaldehyde is 1.0% (wt/vol) in water. However, clinical experience and previous studies suggest that 1.0% might be insufficient for detecting an optimized number of clinically relevant cases of contact allergy to formaldehyde. Objectives.To validate earlier patch test results for comparison of 1% (wt/vol) and 2% (wt/vol) formaldehyde in water, and to investigate co-reactivity with quaternium-15. Materials and methods.In 12 dermatology clinics, 3591 patients were routinely patch tested simultaneously with 2.0% (wt/vol) (0.60 mg/cm2) and 1.0% (wt/vol) (0.30 mg/cm2) formaldehyde. Micropipettes were used for delivering the exact dosage of the allergen. Results.Significantly more patients reacted to 2.0% formaldehyde than to 1.0% (3.4% versus 1.8%, p < 0.001). Overall, there were no sex differences between those reacting positively to 2.0% and 1.0%. Of 25 quaternium-15-positive patients, 4 (0.1%) reacted positively without reacting to formaldehyde. Conclusion.On the basis of the results of this multicentre study, as well as of previous studies, it can be suggested that 2.0% (wt/vol) in water formaldehyde should be used in routine patch testing in the baseline series. [ABSTRACT FROM AUTHOR]

Owing to the lack of practical cell culture system for human noroviruses (HuNoV), various detection methods based on conventional reverse transcription-PCR (RT-PCR) and the quantitative real-time PCR have been major tools for monitoring environmental water safety. In this study, we showed that the proportion of water sample concentrates used for one-step RT-PCR significantly influences false-negative findings of the non-culturable viruses. In total, 59 archived samples of previously analyzed water concentrates were reexamined for HuNoV RNA by the one-step RT-PCR and semi-nested PCR. Using new aliquots for RNA extraction for every trial, up to 20 PCR trials were performed for each archive to determine whether the crosscheck results supported the previous determinations. We reconfirmed that 27.6% (8/29) of the samples were HuNoV-positive samples: 6.7% (1/15) from groundwater, 33.3% (3/9) from river water, and 80% (4/5) from treated sewage effluent (TSE). These results corresponded to the ratio of previously negative HuNoV samples now identified as positive (8/30): 6.7% (1/15) from groundwater, 20% (1/5) from river water, and 60% (6/10) from TSE. To elucidate the cause of these results, 16 different concentrations of murine norovirus (MNV) RNA (from 2×10 to 8×10 copies, divided into 10 tubes for each concentration) were subjected to one-step RT-PCR. The detection frequency and reproducibility decreased sharply when the number of MNV RNA copies fell below threshold levels. These observations suggest that the proportion of water concentrate used for PCR-based detection should be considered carefully when deciding viral presence in certain types of environmental water, particularly in regard with legal controls. [ABSTRACT FROM AUTHOR]

Abstract: Background: The goal of this study was to determine whether sampling error was the major cause for false-negative fine needle aspiration (FNA) results for thyroid nodules. Methods: Patients who underwent preoperative FNA between 1994 and 2008 were identified, and the results were compared with surgical pathology findings. Other related variables including nodule number and size were also recorded. Results: Excluding the microcarcinomas, the false-negative rate was 4% (19/479). Sampling errors occurred in only 4 (21%) cases in which the malignant nodule was not actually biopsied. Of the other 15 cases, 8 (53%) were solitary nodules, 8 (53%) were ≥4 cm in size, and 5 (33%) had underlying thyroiditis. Because of the missed diagnosis, 9 patients (47%) had lobectomy only as the initial surgery, which then required a completion thyroidectomy. Conclusions: Sampling error is a minor cause for false-negative FNAs, suggesting that there are some inherent limitations to cytological evaluation of the thyroid. [Copyright &y& Elsevier]

Background: We previously investigated the current status of breast cytology cancer screening at seven institutes in our area of southern Fukuoka Prefecture, and found some differences in diagnostic accuracy among the institutions. In the present study, we evaluated the cases involved and noted possible reasons for their original cytological classification as inadequate, indeterminate, false-negative and false-positive according to histological type. Methods: We evaluated the histological findings in 5693 individuals who underwent cytological examination for breast cancer (including inadequate, indeterminate, false-negative and false-positive cases), to determine the most common histological types and/or features in these settings and the usefulness/limitations of cytological examination for the diagnosis of breast cancer. Results: Among 1152 cytologically inadequate cases, histology revealed that 75/173 (43.6%) cases were benign, including mastopathy (fibrocystic disease) in 38.6%, fibroadenoma in 24.0% and papilloma in 5.3%. Ninety-five of 173 (54.9%) cases were histologically malignant, with scirrhous growing type, invasive ductal carcinoma (SIDC) being significantly more frequent (49.5%) than papillotubular growing type (Papi-tub) (P < 0.0001), solid-tubular growing type (P = 0.0001) and ductal carcinoma in situ (DCIS) (P = 0.0001). Among 458 indeterminate cases, 54/139 (38.8%) were histologically benign (mastopathy, 30.0%; fibroadenoma, 27.8%; papilloma, 26.0%) and 73/139 (52.5%) were malignant, with SIDC being the most frequent malignant tumor (37.0%). Among 52 false-negative cases, SIDC was significantly more frequent (42.3%) than DCIS (P = 0.0049) and Papi-tub (P = 0.001). There were three false-positive cases, with one each of fibroadenoma, epidermal cyst and papilloma. Conclusions: The inadequate, indeterminate, false-negative and false-positive cases showed similar histological types, notably SIDC for malignant tumors, and mastopathy, fibroadenoma and papilloma for benign cases. We need to pay particular attention to the collection and assessment of aspirates for these histological types of breast disease. In particular, several inadequate, indeterminate and false-negative cases with samples collected by aspiration were diagnosed as SIDC. These findings should encourage the use of needle biopsy rather than aspiration when this histological type is identified on imaging. Namely, good communication between clinicians and pathological staff, and triple assessment (i.e., clinical, pathological and radiological assessment), are important for accurate diagnosis of aspiration samples. [ABSTRACT FROM AUTHOR]

Objective. The results of sentinel lymph node biopsy (SLNB) can be useful for staging and deciding on adjuvant treatment for patients with head and neck melanoma. False-negative SLNB can result in treatment delay. This study aimed to evaluate the characteristics and outcome of patients with false-negative SLNB in cutaneous melanoma of the head and neck.Study Design. Longitudinal cohort study using a prospective institutional tumor registry.Setting. Academic health center.Subjects and Methods. Data from 153 patients who underwent SLNB for melanoma of the head and neck were analyzed. False-negative biopsy was defined as recurrence of tumor in a previously identified negative nodal basin. Statistical analysis was performed on registry data.Results. Positive sentinel lymph nodes were identified in 19 (12.4%) patients. False-negative SLNB was noted in 9 (5.9%) patients, with a false-negative SLNB rate of 32.1%. Using multivariate regression analysis, only examination of a single sentinel lymph node was a significant predictor of false-negative SLNB (P = .01). The mean treatment delay for the false-negative SLNB group was 470 days compared with 23 days in the positive SLNB group (P < .001). The 2-year overall survival of patients with false-negative SLNB was 75% compared with 84% and 98% in positive and negative SLNB groups, respectively (P = .02).Conclusions. False-negative SLNB is more likely to occur when a single sentinel lymph node is harvested. There is significant treatment delay in patients with false-negative SLNB. False-negative SLNB is associated with poor outcome in patients with melanoma of the head and neck. [ABSTRACT FROM AUTHOR]

Abstract: In managing non-native species, surveillance programmes aim to minimise the opportunity for invasions to develop from initial introductions through early detection. However, this is dependent on surveillance methods being able to detect species at low levels of abundance to avoid false-negative recordings through imperfect detection. We investigated through field experimentation the ability to detect Pseudorasbora parva, a highly invasive pest fish in Europe, in relation to their known density and sampling method. Secure pond mesocosms of area 100m2 contained P. parva densities from 0.02 to 5.0m−2; each density was in triplicate. These were searched using point sampling electric fishing and deployment of fish traps (non-baited and baited). No fish were captured at densities <0.5m−2 using any method and this was considered their detection threshold. Point sample electric fishing was the least effective detection method, producing high proportions of false-negative data even at high fish densities. Baited traps were the most effective detection method. Probability of detection of P. parva was 1.0 for baited traps at all densities >0.5m−2, whereas for electric fishing it only exceeded 0.95 at 5.0m−2 using high searching effort. These data reveal that small pest fishes such as P. parva may be prone to imperfect detection when at low densities and this is consistent with a number of other invasive species. This indicates the importance of designing surveillance programmes using methods of known statistical power to optimise conservation resource expenditure and enhance management outcomes. [Copyright &y& Elsevier]

F-Fluoro-2-deoxy- d-glucose (FDG) positron emission tomography (PET) is increasingly being used for the evaluation of several malignancies. Key to the correct interpretation of oncological FDG-PET studies is awareness of the concept that the degree of FDG uptake reflects the biology of the tumor in many cancers. More specifically, cancers with high FDG uptake are often histologically and clinically more aggressive than those with low or no FDG uptake. Therefore, although a negative FDG-PET scan in a patient with a cancer that has a size above the spatial resolution of PET may be interpreted as false-negative in terms of tumor detectability, it should in fact be regarded as true-negative from the view-point of tumor biology. This nonsystematic review will give examples of several major cancers in which the relationship between FDG avidity and tumor biology is applicable, and emphasizes the need to reconsider the definition of a 'false-negative' FDG-PET scan in clinical oncology. [ABSTRACT FROM AUTHOR]

In this study, we correlated the results of concurrent molecular and cytogenetic detection of entity-defining translocations in adults with acute leukemia to determine the frequency of cryptic translocations missed by conventional cytogenetics (CC) and of recurrent, prognostically relevant translocations not detectable by multiplex reverse transcriptase-polymerase chain reaction (MRP). During a 5.5-year period, 442 diagnostic acute leukemia specimens were submitted for MRP-based detection of 7 common recurrent translocations: t(8;21), t(15;17), inv(16), t(9;22), t(12;21), t(4;11), and t(1;19), with a detection rate of 15.2% (67/442). CC was performed in 330 (74.7%) of 442 cases. In 7 of these 330 cases, CC missed the translocation detected by MRP. In 50 additional cases, CC revealed 1 of the MRP-detectable translocations (all were also MRP positive), yielding a false-negative rate of 12% (7/57) for the CC assay. The remaining 140 of 190 cases with clonal cytogenetic changes harbored abnormalities that were not targeted by the MRP assay, including 8 that define specific acute myeloid leukemia entities. This study revealed the frequent occurrence of falsenegative, entity-defining CC analysis and highlighted the complementary nature of MRP and CC approaches in detecting genetic abnormalities in acute leukemia. [ABSTRACT FROM AUTHOR]