scholarly journals A New and Convenient Method to Get Paraffin-Embedded Sections of Tuberculous Bacteria as Positive Quality Controls for Acid-Fast Staining

2020 ◽  
Author(s):  
Lili Tao ◽  
Guangyin Yu ◽  
Chuqiang Huang ◽  
Junliang Tan ◽  
Xiaomin Yin ◽  
...  
Keyword(s):  
Pleural Fluid ◽  
Convenient Method ◽  
Detection Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Positive Control ◽  
Quality Controls ◽  
High False Negative Rate ◽  
Acid Fast Staining ◽  
Positive Quality

Abstract Background: Acid-fast staining for the detection of Mycobacterium tuberculosis has a high false negative-rate, partly due to it is hard to get a good positive control tissue of acid-fast staining. We aimed to design a simple and convenient method for making positive quality controls for acid-fast staining in paraffin-embedded sections.Methods: Three methods were used to get more tuberculous bacteria, which involving centrifugation, mixing, and culture of tubercle bacilli in pleural fluid, prior to the preparation of paraffin-embedded sections.Results: Culturing tubercle bacilli in pleural fluid proved to be, by far, the best of the three methods, with sufficient bacteria, convenient observation, clear staining, and potential for upscaled production.Conclusions: The application of this method should improve the detection rate of tuberculous bacteria, thus facilitating clinical treatment.

scholarly journals High mortality with High false negative rate: COVID-19 infection in patients with hematologic malignancies

2021 ◽  
Vol 106 ◽  
pp. 106582
Author(s):  
Alex Niu ◽  
Bo Ning ◽  
Francisco Socola ◽  
Hana Safah ◽  
Tim Reynolds ◽  
...  
Keyword(s):  
High Mortality ◽  
False Negative ◽  
False Negative Rate ◽  
Hematologic Malignancies ◽  
Negative Rate ◽  
High False Negative Rate

scholarly journals Comparison of Hysterosalpingography and Combined Laparohysteroscopy for the Evaluation of Primary Infertility

2017 ◽  
Vol 13 (4) ◽  
pp. 281-285 ◽  
Author(s):  
A. Nigam ◽  
P. Saxena ◽  
A. Mishra
Keyword(s):  
Detection Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Uterine Cavity ◽  
Cervical Canal ◽  
Diagnostic Modality ◽  
Infertile Patient ◽  
Infertile Women ◽  
Intrauterine Abnormalities

Background Hysterosalpingography (HSG) is a useful screening test for the evaluation of female infertility. Laparoscopy has proven role in routine infertility work up but role of hysteroscopy in an infertile patient with normal HSG for additional information is a subject of debate. Hysteroscopy permits direct visualization of the cervical canal and the uterine cavity and thereby helping in the evaluation of shape, and cavitary lesion.Objective To detect uterine abnormalities in infertile women by various approaches i.e. HSG and hysteroscopy and evaluating the role of combining hysteroscopy with laparoscopy for the evaluation of tubo-uterine factor for primary infertility.Method One twenty eight infertile women were evaluated and HSG was performed as a basic test for evaluation of tubes and uterine cavity. Women were subjected to combined laparoscopic and hysteroscopic examination on evidence of HSG abnormalities. In absence of any HSG abnormality, women were subjected to ovulation induction for three to six months and if they did not conceive during this period they were undertaken for combined laparo-hysteroscopic evaluation.Result The positive predictive value of HSG for detecting the intrauterine abnormalities was 70% among 126 patients where the hysteroscopy could be performed successfully. The diagnostic accuracy of HSG for intrauterine abnormalities revealed false negative rate of 12.96%. The most frequent pathologies encountered by laparoscopy were tubal and/or peritoneal and were found in 68% (87/128) of women. Total 64.06% infertile women had some abnormality on laparoscopy. This detection rate has been increased from 64.06% to 71.86% on including the concomitant hysteroscopy.Conclusion HSG is a good diagnostic modality to detect uterine as well as tubal abnormalities in infertile patient. HSG and hysteroscopy are complementary to each other and whenever the patient is undertaken for diagnostic laparoscopy for the infertility, hysteroscopy should be combined to improve the detection rate of abnormalities especially in communities where there is enormous risk of pelvic infection.

scholarly journals False Negative Mitigation in Group Testing for COVID-19 Screening

2021 ◽  
Vol 8 ◽  
Author(s):  
Amir Reza Alizad Rahvar ◽  
Safar Vafadar ◽  
Mehdi Totonchi ◽  
Mehdi Sadeghi
Keyword(s):  
Viral Load ◽  
False Negative ◽  
Group Testing ◽  
False Negative Rate ◽  
Screening Strategy ◽  
Web Interface ◽  
Rt Pcr ◽  
Promising Candidate ◽  
Testing Method ◽  
High False Negative Rate

After lifting the COVID-19 lockdown restrictions and opening businesses, screening is essential to prevent the spread of the virus. Group testing could be a promising candidate for screening to save time and resources. However, due to the high false-negative rate (FNR) of the RT-PCR diagnostic test, we should be cautious about using group testing because a group's false-negative result identifies all the individuals in a group as uninfected. Repeating the test is the best solution to reduce the FNR, and repeats should be integrated with the group-testing method to increase the sensitivity of the test. The simplest way is to replicate the test twice for each group (the 2Rgt method). In this paper, we present a new method for group testing (the groupMix method), which integrates two repeats in the test. Then we introduce the 2-stage sequential version of both the groupMix and the 2Rgt methods. We compare these methods analytically regarding the sensitivity and the average number of tests. The tradeoff between the sensitivity and the average number of tests should be considered when choosing the best method for the screening strategy. We applied the groupMix method to screening 263 people and identified 2 infected individuals by performing 98 tests. This method achieved a 63% saving in the number of tests compared to individual testing. Our experimental results show that in COVID-19 screening, the viral load can be low, and the group size should not be more than 6; otherwise, the FNR increases significantly. A web interface of the groupMix method is publicly available for laboratories to implement this method.

scholarly journals Sentinel Lymph Node Biopsy in Early Breast Cancer Using the Indocyanine Green Fluorescence Technique: A Validation Study

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Loh Soon Khang ◽  
Suraya Baharudin ◽  
Juliana Abdul Latiff ◽  
Siti Aishah Mahamad Dom ◽  
Shahrun Niza Suhaimi
Keyword(s):  
Breast Cancer ◽  
Lymph Node ◽  
Sentinel Lymph Node ◽  
Early Breast Cancer ◽  
Detection Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Lymph Node Biopsy ◽  
Blue Dye ◽  
Node Biopsy

INTRODUCTION: Introduction: Sentinel lymph node biopsy (SLNB) is now recognized as the standard of care for early breast cancer patients with negative axillary lymph nodes. Various approaches for Sentinel Lymph Node (SLN) identification using either the blue dye method or scintigraphy alone or their combination have been proposed. However, this method is costly and may not be applicable in certain developing countries. SLNB involving the use of indocyanine green (ICG) offers several advantages, and it is valid and safe when in direct comparison with the blue dye method and scintigraphy. Hence, we performed SLNB using this method in early breast cancer as the first center that involves the use of ICG in Malaysia. We performed validation study on this method with the aims to determine its sensitivity and safety profile. MATERIALS AND METHODS: This is a validation and non-randomised prospective observational study involving 20 patients underwent SLNB wherein ICG is used for localisation. The patients were recruited according to the recommendations stipulated in the Malaysia Clinical Practice Guideline. RESULT: The average number of SLNs removed per patient was 4.0 (range, 3–6) with sentinel lymph nodes detection rate at 98.75% (79/80). The false negative rate is at 5%. No adverse events were observed in all cases. CONCLUSION: The ICG fluorescence method is simple, reliable and safe. Moreover, it demonstrates a high SLN detection rate with a low false-negative rate, and it does not require a special instrument for radioisotope use.

Pathologic Assessment of Computerized Tomography Accuracy for the Evaluation of the Laryngeal Cartilaginous Frame Work in Laryngopharyngeal Carcinomas

1989 ◽  
Vol 75 (2) ◽  
pp. 156-162 ◽  
Author(s):  
Sandro Sulfaro ◽  
Francesco Querin ◽  
Luigi Barzan ◽  
Mario Lutman ◽  
Roberto Comoretto ◽  
...  
Keyword(s):  
Computerized Tomography ◽  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Cartilage Destruction ◽  
High False Negative Rate ◽  
Positive Rate ◽  
Pathologic Assessment ◽  
Low Sensitivity

Sixty-six whole-organ sectioned laryngopharyngectomy specimens removed for cancer during a seven-year period were uniformly examined to determine the accuracy of preoperative high resolution computerized tomography (CT) for detection of cartilaginous involvement. Our results indicate that CT has a high overall specificity (88.2%) but a low sensitivity (47.1 %); we observed a high false-negative rate (26.5%) and a fairly low false-positive rate (5.9%). Massive cartilage destruction was easily assessed by CT, whereas both small macroscopic and microscopic neoplastic foci of cartilaginous invasion were missed on CT scans. Moreover, false-positive cases were mainly due to proximity of the tumor to the cartilage. Clinical implications of these results are discussed.

scholarly journals 0587 Convenience vs Accuracy: Negative Predictability of the Home Sleep Test in Clinical Practice

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A225-A225
Author(s):  
C D Morse ◽  
S Meissner ◽  
L Kodali
Keyword(s):  
Clinical Practice ◽  
Sleep Apnea ◽  
False Negative ◽  
False Negative Rate ◽  
True Negative ◽  
Negative Rate ◽  
High False Negative Rate ◽  
Obstructive Sleep ◽  
Respiratory Disturbance ◽  
Lost To Follow Up

Abstract Introduction Sleep apnea is a serious disorder associated with numerous health conditions. In clinical practice, providers order screening home sleep testing (HST) for obstructive sleep apnea (OSA); however, there is limited research about the negative predictive value (NPV) and false negative rate of this test. Providers may not understand HST limitations; therefore, what is the NPV and false negative rate in clinical practice? Methods A retrospective study of non-diagnostic HST is conducted in a Northeastern US rural community sleep clinic. The study population includes adult patients ≥ 18 years old who underwent HST from 2016-2019. The non-diagnostic HST result is compared to the gold standard, the patient’s nocturnal polysomnogram (NPSG). The results provide the NPV (true negative/total) and false negative (true positive/total) for the non-diagnostic HST. Results We identified 211 potential patients with a mean age of 43 years, of which 67% were female. Of those, 85% (n=179) underwent NPSG, with the others declining/delaying testing or lost to follow up. The non-diagnostic HST showed 15.6% NPV for no apnea using AHI<5 and 8.4% NPV using respiratory disturbance index (tRDI)<5. The false negative rate for AHI/tRDI was 84.4% and 91.6%, respectively. The AHI for positive tests ranged from 5-89 per hour (mean AHI 14.9/tRDI 16/hour), of which OSA was identified with an elevated AHI (≥5) ranging from 54.2% mild, 21.8% moderate, and 8.4% severe. Conclusion The high false negative rate of the HST is alarming. Some providers and patients may forgo NPSG after non-diagnostic HST due to a lack of understanding for the HST’s limitations. Knowing that the non-diagnostic HST is a very poor predictor of no sleep apnea will help providers advise patients appropriately for the necessity of the NPSG. The subsequent NPSG provides an accurate diagnosis and, therefore, an informed decision about pursuing or eschewing sleep apnea treatment. Support none

scholarly journals A Deep-Learning-Based Framework for Automated Diagnosis of COVID-19 Using X-ray Images

Information ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 419 ◽  
Author(s):  
Irfan Ullah Khan ◽  
Nida Aslam
Keyword(s):  
Deep Learning ◽  
False Negative ◽  
False Negative Rate ◽  
Complex Nature ◽  
Learning Models ◽  
Daily Lives ◽  
X Ray ◽  
High False Negative Rate ◽  
Diagnosis Method ◽  
Novel Coronavirus

The emergence and outbreak of the novel coronavirus (COVID-19) had a devasting effect on global health, the economy, and individuals’ daily lives. Timely diagnosis of COVID-19 is a crucial task, as it reduces the risk of pandemic spread, and early treatment will save patients’ life. Due to the time-consuming, complex nature, and high false-negative rate of the gold-standard RT-PCR test used for the diagnosis of COVID-19, the need for an additional diagnosis method has increased. Studies have proved the significance of X-ray images for the diagnosis of COVID-19. The dissemination of deep-learning techniques on X-ray images can automate the diagnosis process and serve as an assistive tool for radiologists. In this study, we used four deep-learning models—DenseNet121, ResNet50, VGG16, and VGG19—using the transfer-learning concept for the diagnosis of X-ray images as COVID-19 or normal. In the proposed study, VGG16 and VGG19 outperformed the other two deep-learning models. The study achieved an overall classification accuracy of 99.3%.

scholarly journals Septic arthritis of the knee: the use and effect of antibiotics prior to diagnostic aspiration

2012 ◽  
Vol 94 (5) ◽  
pp. 351-355 ◽  
Author(s):  
P Hindle ◽  
E Davidson ◽  
LC Biant
Keyword(s):  
Septic Arthritis ◽  
Joint Infection ◽  
False Negative ◽  
False Negative Rate ◽  
Standard Test ◽  
Entire Cohort ◽  
High False Negative Rate ◽  
Total Knee ◽  
Prosthetic Knees ◽  
No Gold Standard

Septic arthritis of the native knee joint and total knee arthroplasty both cause diagnostic and treatment issues. There is no gold standard test to diagnose a joint infection and the use of joint aspiration is commonly relied on. It is widely accepted by orthopaedic surgeons that antibiotics should be withheld until aspiration has been performed to increase the odds of identifying an organism. Patients often present to other specialties that may not be as familiar with these principles. Our study found that 25 (51%) of the 49 patients treated for septic arthritis of the native or prosthetic knee in our unit over a 3-year period had received antibiotics prior to discussion or review by the on-call orthopaedic service. Patients were significantly less likely to demonstrate an organism on initial microscopy (entire cohort: p=0.001, native knees: p=0.006, prosthetic knees: p=0.033) or on subsequent culture (entire cohort: p=0.001, native knees: p=0.017, prosthetic knees: p=0.012) of their aspirate if they had received antibiotics. The sensitivity of microscopy in all patients dropped from 58% to 12% when patients had received antibiotics (native knees: 46% to 0%, prosthetic knees: 72% to 27%). The sensitivity of the culture dropped from 79% to 28% in all patients when the patient had received antibiotics (native knees: 69% to 21%, prosthetic knees: 91% to 36%). This study demonstrated how the management of patients with suspected cases of septic arthritis of the knee may be compromised by empirical administration of antibiotics. These patients were significantly less likely to demonstrate an organism on microscopy and culture of their initial aspirate. There is a significant high false negative rate associated with knee aspiration with prior administration of antibiotic therapy.

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