scholarly journals Comparison of RT-PCR, RT-nested PCRs, and real-time PCR for diagnosis of severe fever with thrombocytopenia syndrome: a prospective study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sehrish Jalal ◽  
Seong Yeon Hwang ◽  
Choon-Mee Kim ◽  
Dong-Min Kim ◽  
Na Ra Yun ◽  
...  
Keyword(s):  
Prospective Study ◽  
Symptom Onset ◽  
High Specificity ◽  
Diagnostic Techniques ◽  
Nested Polymerase Chain Reaction ◽  
Convalescent Phase ◽  
Negative Results ◽  
Severe Fever ◽  
Positive Results ◽  
Control Samples

AbstractWe designed a highly sensitive reverse transcription nested polymerase chain reaction targeting the M-segment (NPCR-M) of severe fever with thrombocytopenia syndrome (SFTS) virus. NPCR-M was performed in parallel with three other referenced PCR assays QPCR-S, PCR-M, and NPCR-S to assess their clinical usefulness as routine diagnostic techniques for SFTS. In this multi-centered prospective study, 122 blood samples from 38 laboratory-confirmed SFTS patients and 85 control samples were used. The results demonstrated that QPCR-S and NPCR-S had better sensitivity rate up to 21 days after symptom onset however, the PCR-M showed poor sensitivity after 7 days of symptom onset. Our designed NPCR-M had a higher detection rate up to 40 days from symptom onset and revealed the persistence of SFTSV RNA in the early convalescent phase. No false-positive results were seen for the control samples. Additionally, NPCR-M showed positive results for a sample that initially showed negative results from other PCRs and for many other samples collected in the convalescent phase of SFTS. Our designed nested PCR is suitable for SFTSV detection in patients’ blood collected in the acute and early convalescent phase of SFTS, and shows better sensitivity and high specificity even up to 40 days after symptom onset.

F-18-FDG-hybrid-camera-PET in patients with postoperative fever

2002 ◽  
Vol 41 (01) ◽  
pp. 22-29 ◽  
Author(s):  
C. O. Sahlmann ◽  
K. Lehmann ◽  
U. Siefker ◽  
I. Meyer ◽  
K. Schreiber ◽  
...  
Keyword(s):  
Antibiotic Therapy ◽  
Prospective Study ◽  
Granulation Tissue ◽  
Malignant Disease ◽  
Surgical Wound ◽  
True Negative ◽  
Postoperative Fever ◽  
Fdg Uptake ◽  
Negative Results ◽  
Positive Results

Summary Aim: Evaluation of F-18-FDG-hybrid-camera-PET imaging in patients with undetermined postoperative fever (POF). Methods: Prospective study of 18 patients (9 women, 9 men; age 23-85 years) suffering from POF with 2-fluoro-2’-deoxyglucose (F-18-FDG) using a dual headed coincidence camera (DHCC). Surgery had been performed 5-94 days prior to our investigation. 13 of the 18 patients received antibiotic therapy during the time of evaluation. Ten (55%) had an infectious and eight (45%) a non infectious cause of fever. Results: Increased F-18-FDG-uptake outside the surgical wound occurred in 13 regions (infection n = 11, malignancy n = 2). The sensitivity of F-18-FDG-hybrid-camera-PET in imaging infection in areas outside the surgical wound was 86% and the specificity 100%, respectively. Antibiotic therapy did not negatively influence the results of F-18-FDG-scanning. Increased F-18-FDG-uptake within the surgical wound was seen in 8 of 18 patients. The sensitivity of F-18-FDG-hybrid-camera-PET in imaging infection within the surgical wound was 100% and the specificity 56%, respectively. The interval between surgery and F-18-FDG-scanning was significantly shorter in patients with false positive results compared with patients showing true negative results (median 34 vs. 54 days; p = 0,038). Conclusion: In POF-Patients, F-18-FDG transaxial tomography performed with a F-18-FDG-hybrid-camera-PET is sensitive in the diagnosis of inflammation and malignant disease within and outside the surgical wound. Because of the accumulation of the tracer both in granulation tissue and infection, the specificity in detecting the focus of fever within the surgical wound is poor.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

PET/CT WITH 68GA-PSMA-11 IN DETECTION OF PRIMARY TUMOR AND RECURRENCE OF PROSTATE CANCER

2018 ◽  
Vol 64 (6) ◽  
pp. 799-804
Author(s):  
Darya Ryzhkova ◽  
M. Poyda
Keyword(s):  
Prostate Cancer ◽  
Primary Tumor ◽  
Biochemical Recurrence ◽  
Whole Body ◽  
Negative Results ◽  
Primary Prostate Cancer ◽  
Pet Ct ◽  
The Relationship ◽  
Positive Results ◽  
T Category

Purpose: To study the diagnostic value of PET-CT with 68Ga-PSMA-11 in the diagnosis of a primary prostate cancer, preoperative staging, and the detection of recurrence of prostate cancer (PCa). Methods: 28 patients aged 64.7 ± 8.74 years were included. 10 patients primary prostate cancer, and 18 patients with biochemical recurrence of the disease after radical treatment were examined. All patients underwent PET-CT with 68Ga-PSMA-11 according the whole body protocol. Interpretation of images was performed visually and quantitatively by calculation of SUL max. Results: High focal or diffuse 68Ga-PSMA-11 uptake was found in prostate parenchyma in patients with primary prostate cancer. Additionally metastases in regional lymph nodes were diagnosed in 4 patients and bone metastases were found in one patient. The correlation between 68Ga-PSMA-11 uptake level and Gleason index in the primary tumor (R Spearmen = 0.25, p = 0.57) was not observed. PET-positive results were obtained in 14 patients and PET-negative results in 4 patients with biochemical recurrence of PCa. The relationship between the frequency of PET-positive results and Gleason index was not revealed (R Spearmen = 0.2, p = 0.39). We found a weak but significant correlation between the frequency of PET-positive results and the prostate tumor stage according to the T category (R Spearmen = 0.49, p = 0.049). In patients with low values of PSA (less than 1.0 ng/ml) in 4 out of 9 cases, PET-negative results were obtained. In patients with PSA level more than 1.0 ng/ml PET-positive results were obtained in all cases. Conclusions: PET/CT with 68Ga-PSMA-11 allows to diagnose the primary prostate cancer, to establish the stage of the disease in categories N and M, and also to determine the localization and dissemination of the tumor in patients with biochemical recurrence of prostate cancer. The relationship between 68Ga-PSMA-11 uptake in primary tumor and Gleason index was not found. The probability of obtaining PET-positive results in cases of biochemical recurrence is affected by a PSA level above 1 ng/ml and a high stage of the disease according to the T category (T3-T4).

A Nylon Filter A-ELISA for Detecting Viruses in Water

1993 ◽  
Vol 27 (7-8) ◽  
pp. 135-141 ◽  
Author(s):  
Abidelfatah M. Nasser ◽  
Yehudit Elkana ◽  
Leon Goldstein
Keyword(s):  
Positive Result ◽  
Solid Phase ◽  
Enteric Viruses ◽  
High Specificity ◽  
Negative Results ◽  
Order Of Magnitude ◽  
Lower Background

This study was designed to develop a modification of A-ELISA performed in microtitre plates. Nylon filters have been utilized successfully as a solid phase for the performance of A-ELISA. The use of nylon filters resulted in lower background than nitro-cellulose and paper filters, indicating their suitability as a solid phase for developing A-ELISA. With enteric viruses, human rotaviruses and MS-2 coliphage, negative results were obtained, suggesting high specificity of the developed technique for poliovirus 1. The sensitivity of the developed A-ELISA has been shown to be at least one order of magnitude greater than ordinary ELISA. A positive result with the nylon A-ELISA can be obtained with samples containing 100-1000 pfu/ml of poliovirus. Up to date methods used for detecting viruses in water are elaborate, time consuming and costly. Applying the nylon A-ELISA may overcome some of these disadvantages.

scholarly journals Diagnostic Performance of Ankle-Brachial Pressure Index in Lower Extremity Arterial Disease

2021 ◽  
Vol 07 (03) ◽  
pp. e132-e137
Author(s):  
Mohammed Alagha ◽  
Thomas M. Aherne ◽  
Ahmed Hassanin ◽  
Adeel S. Zafar ◽  
Doireann P. Joyce ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Sensitivity And Specificity ◽  
False Negative ◽  
Arterial Disease ◽  
Initial Assessment ◽  
Reference Standard ◽  
Lower Extremity Arterial Disease ◽  
Negative Results ◽  
Positive Results ◽  
Arterial Imaging

Abstract Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for lower extremity arterial disease (LEAD). However, there remains a paucity of data to support its accuracy. This study aims to evaluate its diagnostic sensitivity and specificity using established arterial-imaging modalities as a benchmark. Methods In this retrospective study, a regional, prospectively maintained, vascular laboratory database was interrogated to identify referred patients with arterial disease who underwent concomitant assessment with ABI and lower limb arterial duplex ultrasound (DUS). Duplex acted as the reference standard. Those who had peripheral computed tomography angiogram (CTA) within 3 months of initial assessment were included in a subgroup analysis to correlate ABI with CTA. The primary end point was the sensitivity and specificity of ABI compared with DUS as the reference standard. Results Concomitant assessment was performed in 438 limbs (250 patients) over a 27-month period. The ABI was normal (0.9 to 1.4) in 196 limbs (44.9%) and abnormal in the remaining 241 limbs (55.1%). False-positive results occurred in 83 out of 241 limbs (34.4%), and false-negative results occurred in 54 limbs out of 196 (27.5%). True-positive results were 158 out of 241 limbs (65.6%), whereas true-negative results were 142 out of 196 limbs (72.4%). ABI using DUS as a benchmark identified a sensitivity for peripheral artery disease of 72.3% and a specificity of 69.3%. Concomitant CTA imaging was available in 200 limbs. The sensitivity and specificity of ABI correlated with CTA were 65.5 and 68.8%, respectively. Conclusion ABIs have a moderate predictive value in the diagnosis of LEAD. Normal range outcomes cannot be taken to infer the absence of LEAD and, as such, further arterial imaging in the form of DUS or angiography should be strongly considered in those with suspected underlying disease requiring intervention. Further noninvasive tests such as exercise studies or pulse volume waveforms should be considered, if diagnostic uncertainty exists, in those requiring nonoperative intervention and risk factor control.

scholarly journals The Interpretation of Studies Using the Reading Level Design

1989 ◽  
Vol 21 (4) ◽  
pp. 413-424 ◽  
Author(s):  
Usha Goswami ◽  
Peter Bryant
Keyword(s):  
Reading Disability ◽  
Reading Level ◽  
Chronological Age ◽  
Control Group ◽  
Causal Factors ◽  
Negative Results ◽  
Level Design ◽  
Positive Results

Recent research in reading disability has been strengthened by the addition of a reading level (RL) control group to the more traditional chronological age (CA) control group. However, caution is required in interpreting results from these two kinds of control. Only positive results in a RL match and negative results in a CA match are interpretable; negative results in a CA match and positive results in a RL match are not. Furthermore, the RL control group cannot be used to unambiguously determine between specific deficit and developmental lag interpretations of reading disability. It is argued that the use of the RL control can only ever be a first step in research aimed at delineating the causal factors in reading backwardness.

scholarly journals Accuracy of brush cytology in biliopancreatic strictures: a single-center cohort study

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098777
Author(s):  
Song-Ming Ding ◽  
Ai-Li Lu ◽  
Bing-Qian Xu ◽  
Shao-Hua Shi ◽  
Muhammad Ibrahim Alhadi Edoo ◽  
...  
Keyword(s):  
Duct Cell ◽  
Carbohydrate Antigen ◽  
Maximum Diameter ◽  
Biliary Duct ◽  
Brush Cytology ◽  
Tumor Biopsy ◽  
Bile Duct Wall ◽  
Negative Results ◽  
Brushing Cytology ◽  
Positive Results

Objective False positive and negative results are associated with biliary tract cell brushing cytology during endoscopic retrograde cholangiopancreatography (ERCP). The causes are uncertain. The purpose of this study was to evaluate the accuracy of diagnoses made via cell brushing in our center, and to explore the factors influencing diagnosis. Methods The clinical data of patients who underwent cell brushing at our center from January 2016 to August 2019 were retrospectively analyzed. These included age, gender, stricture location, thickness of the bile duct wall in the narrow segment, maximum diameter of the biliary duct above the stricture, number of cell brush smears, carbohydrate antigen 19-9, and carcinoembryonic antigen. Positive brush cytology results were compared with results of surgical histology or tumor biopsy as well as with the patient’s clinical course. Results Of the 48 patients who underwent cell brushing cytology, 27 (56.3%) had positive results. The sensitivity and specificity of biliary duct cell brushing was 79.4%, and 85.7%, respectively. None of the above-mentioned factors were associated with positive cytology brushing results. Conclusions Cell brushing cytology remains a reliable method for diagnosis of pancreaticobiliary malignancies.

Studies on Diagnosis of Bovine Brucellosis by Immunocyto-chemistry and Immunohistochemistry

2021 ◽  
Author(s):  
K.S. Lakshmikanth ◽  
N.S. Sharma ◽  
D. Pathak ◽  
Paviter Kaur
Keyword(s):  
Biochemical Analysis ◽  
Placental Tissue ◽  
Diagnostic Techniques ◽  
Clinical Samples ◽  
Bovine Brucellosis ◽  
Reproductive Disorders ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Polymerase Chain ◽  
Positive Results

Background: Brucellosis is a major threat to livestock economy and an important zoonotic disease. A rapid and accurate diagnosis is a necessity to curb the spread and progress of the disease. The current study aimed to evaluate sensitivity of Immunocytochemistry and Immunohistochemistry methods for detection of Brucella spp.Methods: A total of 50 samples comprising of fetal stomach content, vaginal discharges and placenta were collected from cattle and buffaloes suffering from abortions and other reproductive disorders in and around Ludhiana, Punjab during the period 2017-2018. All the samples were processed for isolation and confirmed with biochemical analysis and Polymerase chain reaction (PCR). The isolates obtained and 43 clinical samples excluding placental samples were subjected to Immunocytochemistry (ICC). Immunohistochemistry (ICH) was performed on placental samples.Result: A total of four isolates were recovered from the screened samples. The four isolates also yielded positive results in Immunocytochemistry. Among the 43 clinical samples screened by Immunocytochemistry, five were positive, however only 3 isolates were recovered on isolation. A total of seven placental tissue samples were processed and subjected to immunohistochemistry. Of the three placental samples positive by immunohistochemistry, only one sample was isolated on culture. The results suggest that both immunocytochemistry and immunohistochemistry are sensitive diagnostic techniques in comparison to isolation.

scholarly journals The Positive Predictive Value of Diagnostic Ultrasound for Occult Herniae

2006 ◽  
Vol 88 (2) ◽  
pp. 165-167 ◽  
Author(s):  
M Bradley ◽  
J Morgan ◽  
B Pentlow ◽  
A Roe
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Diagnostic Tests ◽  
Diagnostic Ultrasound ◽  
Pain Clinic ◽  
Diagnostic Problem ◽  
Clinical Criteria ◽  
Negative Results ◽  
Positive Results

INTRODUCTION The aim of this study is to ascertain the accuracy of diagnostic ultrasound in the assessment of the occult abdominal and groin herniae. The authors have previously demonstrated its efficacy in diagnosing the type of clinical groin herniae but occult herniae provide a further diagnostic problem. PATIENTS AND METHODS A total of 113 consecutive patients were referred prospectively for ultrasound examinations with clinically suspected occult herniae. All positive scans were offered surgery whilst the negative results were offered further imaging or other diagnostic tests depending on the clinical criteria. The end point for negative scans was based on 18-month follow-up or resolution of symptoms. RESULTS Overall, 59 scans showed positive results for herniae and 56 of these had surgery. In the other three patients, two refused an operation, and one had no hernia detected at operation. In the remaining 57 scans, ultrasound offered alternative soft tissue diagnoses in 23 patients and surgical/endoscopic diagnoses accounted for a further 8 patients. CONCLUSIONS Ultrasound offered a diagnosis for the symptomology in 82 patients (70.6%) of which 59 were herniae. The positive predictive value for hernia is 98.3%. Twenty-six patients with no diagnosis or confirmation of herniae on follow-up showed symptom resolution in 22 cases, and four patients were treated by the pain clinic.

scholarly journals A 16S rDNA-based nested PCR protocol to detect Campylobacter gracilis in oral infections

2003 ◽  
Vol 17 (2) ◽  
pp. 142-146 ◽  
Author(s):  
José Freitas Siqueira Júnior ◽  
Isabela das Neves Rôças
Keyword(s):  
16S Rdna ◽  
High Sensitivity ◽  
High Specificity ◽  
Cross Reactivity ◽  
Nested Polymerase Chain Reaction ◽  
Oral Infections ◽  
Root Canals ◽  
Infected Root ◽  
Pcr Products ◽  
Species Specific

The aim of this study was to describe a 16S rDNA-based nested polymerase chain reaction (nPCR) assay to investigate the occurrence of Campylobacter gracilis in oral infections. Samples were collected from ten infected root canals, ten cases of acute periradicular abscesses and eight cases of adult marginal periodontitis. DNA extracted from the samples was initially amplified using universal 16S rDNA primers. A second round of amplification used the first PCR products to detect C. gracilis using oligonucleotide primers designed from species-specific 16S rDNA signature sequences. The nPCR assay used in this study showed a detection limit of 10 C. gracilis cells and no cross-reactivity was observed with nontarget bacteria. C. gracilis was detected in the three types of oral infections investigated - 4/10 infected root canals; 2/10 acute periradicular abscesses; and 1/8 subgingival specimens from adult periodontitis. The method proposed in this study showed both high sensitivity and high specificity to directly detect C. gracilis in samples from root canal infections, abscesses, and subgingival plaque. Our findings confirmed that C. gracilis may be a member of the microbiota associated with distinct oral infections, and its specific role in such diseases requires further clarification.

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