Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)
Syphilis serodiagnosis employing as the antigen Treponema pallidum obtained from rabbit syphilis orchitis. Treponemes are kept alive for a few hours in a special medium. When syphilitic serum and complement are added and incubated, the treponemes are immobilized, i.e., stop moving.
Serologic tests for syphilis.
A contagious venereal disease caused by the spirochete TREPONEMA PALLIDUM.
Passive agglutination tests in which antigen is adsorbed onto latex particles which then clump in the presence of antibody specific for the adsorbed antigen. (From Stedman, 26th ed)
Skin tests in which the sensitizer is applied to a patch of cotton cloth or gauze held in place for approximately 48-72 hours. It is used for the elicitation of a contact hypersensitivity reaction.
Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
Epicutaneous or intradermal application of a sensitizer for demonstration of either delayed or immediate hypersensitivity. Used in diagnosis of hypersensitivity or as a test for cellular immunity.
Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.
Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
Tests that are dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum. (From Stedman, 26th ed)
Studies determining the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. For drugs and devices, CLINICAL TRIALS AS TOPIC; DRUG EVALUATION; and DRUG EVALUATION, PRECLINICAL are available.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Diagnostic procedures involving immunoglobulin reactions.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
Techniques used in studying bacteria.
Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.
The larval form of the diphyllobothriid tapeworms of the genus DIPHYLLOBOTHRIUM and SPIROMETRA. Fish-eating mammals and man are the final hosts.
Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.
Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)
A recurrent contact dermatitis caused by substances found in the work place.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use.
Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.
A delayed hypersensitivity involving the reaction between sunlight or other radiant energy source and a chemical substance to which the individual has been previously exposed and sensitized. It manifests as a papulovesicular, eczematous, or exudative dermatitis occurring chiefly on the light-exposed areas of the skin.
In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.
The process of observing, recording, or detecting the effects of a chemical substance administered to an individual therapeutically or diagnostically.
A protein extracted from boiled culture of tubercle bacilli (MYCOBACTERIUM TUBERCULOSIS). It is used in the tuberculin skin test (TUBERCULIN TEST) for the diagnosis of tuberculosis infection in asymptomatic persons.
One of several skin tests to determine past or present tuberculosis infection. A purified protein derivative of the tubercle bacilli, called tuberculin, is introduced into the skin by scratch, puncture, or interdermal injection.
Prudent standard preventive measures to be taken by professional and other health personnel in contact with persons afflicted with a communicable disease, to avoid contracting the disease by contagion or infection. Precautions are especially applicable in the diagnosis and care of AIDS patients.
An active immunizing agent and a viable avirulent attenuated strain of Mycobacterium tuberculosis, var. bovis, which confers immunity to mycobacterial infections. It is used also in immunotherapy of neoplasms due to its stimulation of antibodies and non-specific immunity.
Directions or principles presenting current or future rules of policy for assisting health care practitioners in patient care decisions regarding diagnosis, therapy, or related clinical circumstances. The guidelines may be developed by government agencies at any level, institutions, professional societies, governing boards, or by the convening of expert panels. The guidelines form a basis for the evaluation of all aspects of health care and delivery.
Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.
An anticonvulsant used for several types of seizures, including myotonic or atonic seizures, photosensitive epilepsy, and absence seizures, although tolerance may develop. It is seldom effective in generalized tonic-clonic or partial seizures. The mechanism of action appears to involve the enhancement of GAMMA-AMINOBUTYRIC ACID receptor responses.
A carbamate derivative used as an alcohol deterrent. It is a relatively nontoxic substance when administered alone, but markedly alters the intermediary metabolism of alcohol. When alcohol is ingested after administration of disulfiram, blood acetaldehyde concentrations are increased, followed by flushing, systemic vasodilation, respiratory difficulties, nausea, hypotension, and other symptoms (acetaldehyde syndrome). It acts by inhibiting aldehyde dehydrogenase.
An anticonvulsant used to control grand mal and psychomotor or focal seizures. Its mode of action is not fully understood, but some of its actions resemble those of PHENYTOIN; although there is little chemical resemblance between the two compounds, their three-dimensional structure is similar.
A histamine H1 antagonist used as an antiemetic, antitussive, for dermatoses and pruritus, for hypersensitivity reactions, as a hypnotic, an antiparkinson, and as an ingredient in common cold preparations. It has some undesired antimuscarinic and sedative effects.
An antibacterial agent that is a semisynthetic analog of LINCOMYCIN.
A plant species of the genus CITRUS, family RUTACEAE that produces the familiar grapefruit. There is evidence that grapefruit inhibits CYTOCHROME P-450 CYP3A4, resulting in delayed metabolism and higher blood levels of a variety of drugs.
Infection with tapeworms of the genus Taenia.
A genus of large tapeworms.
An infection caused by the infestation of the larval form of tapeworms of the genus Echinococcus. The liver, lungs, and kidney are the most common areas of infestation.
Liver disease caused by infections with parasitic tapeworms of the genus ECHINOCOCCUS, such as Echinococcus granulosus or Echinococcus multilocularis. Ingested Echinococcus ova burrow into the intestinal mucosa. The larval migration to the liver via the PORTAL VEIN leads to watery vesicles (HYDATID CYST).
A genus of very small TAPEWORMS, in the family Taeniidae. The adult form is found in various CARNIVORA but not humans. The larval form is seen in humans under certain epidemiologic circumstances.
Helminth infection of the lung caused by Echinococcus granulosus or Echinococcus multilocularis.
Species of tapeworm in the genus TAENIA, that infects swine. It is acquired by humans through the ingestion of cured or undercooked pork.

Rational sequence of tests for pancreatic function. (1/3575)

Of 144 patients with suspected pancreatic disease in whom a 75Se-selenomethionine scan was performed, endoscopic retrograde pancreatography (ERP) was successful in 108 (75%). The final diagnosis is known in 100 patients and has been compared with scan and ERP findings. A normal scan reliably indicated a normal pancreas, but the scan was falsely abnormal in 30%. ERP distinguished between carcinoma and chronic pancreatitis in 84% of cases but was falsely normal in five patients with pancreatic disease. In extrahepatic biliary disease both tests tended to give falsely abnormal results. A sequence of tests to provide a rapid and reliable assessment of pancreatic function should be a radio-isotope scan, followed by ERP if the results of the scan are abnormal, and a Lundh test if the scan is abnormal but the findings on ERP are normal.  (+info)

Defining and analysing symptom palliation in cancer clinical trials: a deceptively difficult exercise. (2/3575)

The assessment of symptom palliation is an essential component of many treatment comparisons in clinical trials, yet an extensive literature search revealed no consensus as to its precise definition, which could embrace relief of symptoms, time to their onset, duration, degree, as well as symptom control and prevention. In an attempt to assess the importance of these aspects and to compare different methods of analysis, we used one symptom (cough) from a patient self-assessment questionnaire (the Rotterdam Symptom Checklist) in a large (>300 patient) multicentre randomized clinical trial (conducted by the Medical Research Council Lung Cancer Working Party) of palliative chemotherapy in small-cell lung cancer. The regimens compared were a two-drug regimen (2D) and a four-drug regimen (4D). No differences were seen between the regimens in time of onset of palliation or its duration. The degree of palliation was strongly related to the initial severity: 90% of the patients with moderate or severe cough at baseline reported improvement, compared with only 53% of those with mild cough. Analyses using different landmark time points gave conflicting results: the 4D regimen was superior at 1 month and at 3 months, whereas at 2 months the 2D regimen appeared superior. When improvement at any time up to 3 months was considered, the 4D regimen showed a significant benefit (4D 79%, 2D 60%, P = 0.02). These findings emphasize the need for caution in interpreting results, and the importance of working towards a standard definition of symptom palliation. The current lack of specified criteria makes analysis and interpretation of trial results difficult, and comparison across trials impossible. A standard definition of palliation for use in the analysis of clinical trials data is proposed, which takes into account aspects of onset, duration and degree of palliation, and symptom improvement, control and prevention.  (+info)

Computerized analysis of abnormal asymmetry in digital chest radiographs: evaluation of potential utility. (3/3575)

The purpose of this study was to develop and test a computerized method for the fully automated analysis of abnormal asymmetry in digital posteroanterior (PA) chest radiographs. An automated lung segmentation method was used to identify the aerated lung regions in 600 chest radiographs. Minimal a priori lung morphology information was required for this gray-level thresholding-based segmentation. Consequently, segmentation was applicable to grossly abnormal cases. The relative areas of segmented right and left lung regions in each image were compared with the corresponding area distributions of normal images to determine the presence of abnormal asymmetry. Computerized diagnoses were compared with image ratings assigned by a radiologist. The ability of the automated method to distinguish normal from asymmetrically abnormal cases was evaluated by using receiver operating characteristic (ROC) analysis, which yielded an area under the ROC curve of 0.84. This automated method demonstrated promising performance in its ability to detect abnormal asymmetry in PA chest images. We believe this method could play a role in a picture archiving and communications (PACS) environment to immediately identify abnormal cases and to function as one component of a multifaceted computer-aided diagnostic scheme.  (+info)

Brightness alters Heidelberg retinal flowmeter measurements in an in vitro model. (4/3575)

PURPOSE: The Heidelberg Retinal Flowmeter (HRF), a laser Doppler flowmetry device, has captured interest as a research and clinical tool for measurement of ocular blood flow. Concerns remain about the range and accuracy of the values that it reports. METHODS: An in vitro blood-flow model was constructed to provide well-controlled laminar flow through a glass capillary for assessment by HRF. A change in material behind the glass capillary was used to simulate changing brightness conditions between eyes. RESULTS: Velocities reported by the HRF correlated linearly to true velocities below 8.8 mm/sec. Beyond 8.8 mm/sec, HRF readings fluctuated randomly. True velocity and HRF reported velocities were highly correlated, with r = 0.967 (P < 0.001) from 0.0 mm/sec to 2.7 mm/sec mean velocity using a light background, and r = 0.900 (P < 0.001) from 2.7 mm/sec to 8.8 mm/sec using a darker background. However, a large change in the y-intercept occurred in the calibration curve with the background change. CONCLUSIONS: The HRF may report velocities inaccurately because of varying brightness in the fundus. In the present experiment, a darker background produced an overreporting of velocities. An offset, possibly introduced by a noise correction routine, apparently contributed to the inaccuracies of the HRF measurements. Such offsets vary with local and global brightness. Therefore, HRF measurements may be error prone when comparing eyes. When used to track perfusion in a single eye over time, meaningful comparison may be possible if meticulous care is taken to align vessels and intensity controls to achieve a similar level of noise correction between measurements.  (+info)

Improved methods using the reverse transcriptase polymerase chain reaction to detect tumour cells. (5/3575)

Reverse transcriptase polymerase chain reaction (RT-PCR) is increasingly used to detect small numbers of circulating tumour cells, though the clinical benefit remains controversial. The largest single contributing factor to the controversy of its value is the different approaches to sample processing. The aim of this study was to compare the sensitivity and reproducibility of RT-PCR for the detection of tumour cells after four commonly used different methods of sample processing. Using RT-PCR, one tumour cell spiked in 2 ml of whole blood was detected after analysis of separated mononuclear cell RNA, whole blood total or poly-A+ RNA. No false positives were identified with any method. However, the reproducibility of tumour cell detection was reduced after isolation of the mononuclear cell fraction. Only analysis of poly-A+ RNA had a sensitivity of 100% in all the cell spiking experiments. In patient blood samples, analysis of poly-A+ RNA increased the number of blood samples positive for tyrosine hydroxylase (TH) mRNA compared with those positive after analysis of total RNA. This may reflect high levels of cDNA reducing the efficiency of the PCR. Isolation of poly-A+ RNA increases the sensitivity and reproducibility of tumour cell detection in peripheral blood.  (+info)

Extensive cross-contamination of specimens with Mycobacterium tuberculosis in a reference laboratory. (6/3575)

A striking increase in the numbers of cultures positive for Mycobacterium tuberculosis was noticed in a mycobacterial reference laboratory in Campinas, Sao Paulo State, Brazil, in May 1995. A contaminated bronchoscope was the suspected cause of the increase. All 91 M. tuberculosis isolates grown from samples from patients between 8 May and 18 July 1995 were characterized by spoligotyping and IS6110 fingerprinting. Sixty-one of the 91 isolates had identical spoligotype patterns, and the pattern was arbitrarily designated S36. The 61 specimens containing these isolates had been processed and cultured in a 21-day period ending on 1 June 1995, but only 1 sample was smear positive for acid-fast bacilli. The patient from whom this sample was obtained was considered to be the index case patient and had a 4+ smear-positive lymph node aspirate that had been sent to the laboratory on 10 May. Virtually all organisms with spoligotype S36 had the same IS6110 fingerprint pattern. Extensive review of the patients' charts and investigation of laboratory procedures revealed that cross-contamination of specimens had occurred. Because the same strain was grown from all types of specimens, the bronchoscope was ruled out as the outbreak source. The most likely source of contamination was a multiple-use reagent used for specimen processing. The organism was cultured from two of the solutions 3 weeks after mock contamination. This investigation strongly supports the idea that M. tuberculosis grown from smear-negative specimens should be analyzed by rapid and reliable strain differentiation techniques, such as spoligotyping, to help rule out laboratory contamination.  (+info)

Introduction of appendiceal CT: impact on negative appendectomy and appendiceal perforation rates. (7/3575)

OBJECTIVE To evaluate the impact of appendiceal computed tomography (CT) availability on negative appendectomy and appendiceal perforation rates. SUMMARY BACKGROUND DATA: Appendiceal CT is 98% accurate. However, its impact on negative appendectomy and appendiceal perforation rates has not been reported. METHODS: The authors reviewed the medical records of 493 consecutive patients who underwent appendectomy between 1992 and 1995, 209 consecutive patients who underwent appendectomy in 1997 (59% of whom had appendiceal CT), and 206 patients who underwent appendiceal CT in 1997 without subsequent appendectomy. RESULTS: Before appendiceal CT, 98/493 patients (20%) taken to surgery had a normal appendix. After CT availability, 15/209 patients (7%) taken to surgery had a normal appendix; 7 patients did not have CT, 5 patients had surgery despite a negative CT, and 3 patients had a false-positive CT. Negative appendectomy rates were lowered overall (20% to 7%), in men (11% to 5%), in women (35% to 11%), in boys (10% to 5%), and in girls (18% to 12%). Appendiceal perforation rates dropped from 22% to 14% after CT availability. CT excluded appendicitis in 206 patients in 1997 who avoided appendectomy and identified alternative diagnoses in 105 of these patients (51%). CONCLUSION: The availability of appendiceal CT coincided with a drop in the negative appendectomy rate from 20% to 7% in all patients, and to only 3% in patients with a positive CT. Perforation rates decreased from 22% to 14%. Appendiceal CT can be advocated in nearly all female and many male patients.  (+info)

Comparison of standard and CA-125 response criteria in patients with epithelial ovarian cancer treated with platinum or paclitaxel. (8/3575)

PURPOSE: To assess CA-125 as a measure of response in patients treated with paclitaxel. PATIENTS AND METHODS: One hundred forty-four patients treated with paclitaxel derived from four different trials and 625 patients treated with platinum from two trials were analyzed using precisely defined 50% and 75% reductions in CA-125. The standard and CA-125 response rates to paclitaxel and platinum were compared. In addition, we analyzed individual patient groups in which there was a difference in response according to the two response criteria. RESULTS: Patients with stable disease as determined by standard criteria who were treated with platinum and responded according to CA-125 criteria have an improved median progression-free survival compared with patients with stable disease who did not respond according to CA-125 criteria (10.6 v 4.8 months; P<.001). Standard and CA-125 response rates for patients treated with platinum (58.93% v 61.31%, respectively) and paclitaxel (30.65% v 31.67%, respectively) were very similar, as were rates of false-positive prediction of response by CA-125 (platinum 2.2% and paclitaxel 2.9%). Responders to paclitaxel had a significantly improved progression-free survival compared with non-responders by both standard criteria (median progression-free survival, 6.8 v 2.5 months; P<.001) and CA-125 criteria (median progression-free survival, 6.8 v 3.4 months; P<.001). CONCLUSION: Forassessing activity of therapy for ovarian cancer, these data show that precise 50% or 75% CA-125 response criteria are as sensitive as standard response criteria. We propose that they may be used as a measure of response in lieu of or in addition to standard response criteria in clinical trials involving epithelial ovarian cancer. Sensitivity is maintained whether patients are treated with platinum or paclitaxel.  (+info)

Testing for fecal occult blood can reduce the incidence and mortality from colorectal cancer. An annual screening is recommended for every person 50 years and older. Eating red meat, poultry, fish, certain raw vegetables, or taking some medications can cause false-positive test results. In addition, intake of vitamin C can cause false-negative test results. Few data address the advisability of restricting the use of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) during the stool specimen collection process for fecal occult blood testing. Various studies have attempted to define this issue but have had different limitations. Clinical guidelines state that it is unclear if low-dose aspirin can cause false-positive test results, and higher doses may cause problems. Kahi and Imperiale evaluated whether the regular use of aspirin or NSAIDs has any effect on the risk of false-positive fecal occult blood tests in patients that are likely to present to family physicians.. The trial design was ...
We reviewed reports of false-positive cultures for Mycobacterium tuberculosis and here propose guidelines for detecting and managing patients with possible false-positive cultures. Mechanisms of false-positive cultures included contamination of clinical devices, clerical errors, and laboratory cross-contamination. False-positive cultures were identified in 13 (93%) of the 14 studies that evaluated ⩾100 patients; the median false-positive rate was 3.1% (interquartile range, 2.2%-10.5%). Of the 236 patients with false-positive cultures reported in sufficient detail, 158 (67%) were treated, some of whom had toxicity from therapy, as well as unnecessary hospitalizations, tests, and contact investigations. Having a single positive culture was a sensitive but nonspecific criterion for detecting false-positive cultures. False-positive cultures for M. tuberculosis are not rare but are infrequently recognized by laboratory and clinical personnel. Laboratories and tuberculosis control programs should ...
During trials of preventive HIV vaccines, trial participants may develop HIV-related antibody responses that could lead to a positive HIV test by routine antibody detection methods (called vaccine-induced seropositivity/reactivity ...
Cedar nut oil makes menstrual pain and menopause easier to endure. Menopause Temperature Hot Flash Metformin Can False Positive Test Pregnancy Cause menopause - A cessation of ovarian function marked by the last Menopause Temperature Hot Flash Metformin Can False Positive Test Pregnancy Cause menstrual period. All herbal methods to stimulate teh hypothalmus to do what the body As far as I know there arent any over the counter medicines to help you.. A Nielsen spokesman said we have big plans for this campus. Post ablation syndrome. Polycystic ovarian syndrome (PCOS) a leading cause of cycle irregularities is seen which avoid the complication of multiple time scales. Prior evidence indicates that estrogen impacts the function of various. together with hysterectomy was associated with increased carotid arterial wall thickening.. Up to one in five women worldwide suffer from Polycystic Ovary Syndrome (PCOS) and must juggle various treatments that take care of the. If the testes begin producing ...
Be Aware: Tattoos Might Cause False-Positive Test Results for Cancer You love your tattoos. They are an artistic, permanent way to express your own individualistic personality and style. But tattoos can cause skin problems. They have been known to give test results that indicate that you have skin cancer when you do not. False-positive skin…. Read more ...
Objective We assessed the influence of external factors on false-positive, false-negative, and invalid fibronectin results in the prediction of spontaneous delivery within 7 days. Methods We studied symptomatic women between 24 and 34 weeks gestational age. We performed uni- and multivariable logistic regression to estimate the effect of external factors (vaginal soap, digital examination, transvaginal sonography, sexual intercourse, vaginal bleeding) on the risk of false-positive, false-negative, and invalid results, using spontaneous delivery within 7 days as the outcome. Results Out of 708 women, 237 (33%) had a false-positive result; none of the factors showed a significant association. Vaginal bleeding increased the proportion of positive fetal fibronectin (fFN) results, but was significantly associated with a lower risk of false-positive test results (odds ratio [OR], 0.22; 95% confidence intervals [CI], 0.12-0.39). Ten women (1%) had a false-negative result. None of the investigated ...
PURPOSE: To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC) for colorectal cancer screening. MATERIALS AND METHODS: Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between standard CTC and enhanced CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses. RESULTS: Data from 122 participants were analysed. There were 30 (25%) non-traders for the cancer scenario and 20 (16%) for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to |85) drop in specificity, equating to 2250 (IQR 1250 to |4250) additional false-positives per additional true
The drug test companies maintain that the reliability of their tests has improved dramatically over the last decade, but Im not sure I believe that. After all, these are the same folks who lied about the quality of urine testing in the first place so Im not sure why I should trust them when they say, Oh, we fixed that…. Urinalysis continues to be a limited - some might say flawed - science, and many common substances can still lead to a false positive result.. Which substances?. Lets start with the NSAIDs - Nonsteroidal anti-inflammatory drugs are a category of Over-The-Counter (OTC) medicines and many NSAIDs can test positive for cannabis. Ibuprofen is a prolific triple-threat NSAID that can provide a false positive result for marijuana, barbiturates, or benzodiazepines.. Also, many OTC medications are combined with pseudoephedrine, which, as anyone who has ever watched Breaking Bad will tell you, is a synthetic amphetamine highly coveted by the criminal class to make meth!. So any ...
The universitys researchers included small amounts of HIV protein as a molecular clamp as part of the vaccines design.. Although the universitys researchers have confirmed the protein fragment poses absolutely no health risk to people who have taken the vaccine, they have identified a partial antibody response to it among trial participants, Health Minister Greg Hunt said.. This has the potential to interfere with some HIV screening tests that look for these antibodies - leading to a false-positive test result, he said.. CSL stressed that no participant had contracted the HIV infection.. I want to emphasize there are no adverse health reactions and theres no possibility the vaccine causes HIV infection, CSLs chief scientific officer Andrew Nash said.. This outcome highlights the risk of failure associated with early vaccine development, and the rigorous assessment involved in making decisions as to what discoveries advance, said Nash.. While the vaccine had proved promising ...
ZIKV laboratory tests should be considered in pregnant women who travel to regions with active ZIKV, as well as neonates born to these women (68, 69). These laboratory tests include RT-PCR for symptomatic patients or those with exposure to the virus within the past 2 weeks and serological assessment for people, exposed to the infection within the past 2 to 12 weeks. However, false-positive test results could be detected in patients infected with other flaviviruses; in fact, a negative test result does not ultimately reject ZIKV infection (70).. A specific test of ZIKV is the plaque reduction neutralization test, which measures virus-specific neutralizing antibodies (anti-ZIKV IgM antibodies) (71). ZIKV RT-PCR test should be performed on both infants serum and urine samples. Also, ZIKV DetectTM IgM ELISA should be simultaneously performed on the serum within the first 2 days of life. In general, laboratory tests for pregnant women with ZIKV infection include RT-PCR to detect ZIKV RNA in maternal ...
Despite improvements in screening tests, none are perfect. Occasionally, proteins or chemical agents in the blood cause a first positive result, even when there is no infection.. Staff in charge of blood services and at Health Canadas Health Products & Food Branch are well aware of the possibility of false positive results and explain this phenomenon by the high degree of sensitivity of the tests used. At Héma-Québec, five to ten false reactions are recorded each week from among the thousands of blood donations analyzed. The sensitivity of the tests ensures their reliability.. The sensitivity of the screening tests can be compared to a smoke detector alarm that suddenly goes off when the device detects heat or smoke. The detectors sensor sets off the alarm even when the heat or smoke is not from a real fire. The sound alerts us to quickly check if the fire is real or if it is a false alarm.. ...
Question - How common is it for Hep B test to show false positive results?. Ask a Doctor about Vaccination, Ask an Internal Medicine Specialist
First trimester screening is the current standard of care for pregnant women in the United States. Women with a high screening risk for trisomy then have invasive testing, which carries a risk of miscarriage, to definitively determine if the fetus has trisomy. Because of the high false negative rate of the first trimester screening, an unacceptable number of trisomic fetuses are not detected. Moreover, because of the high false positive rate, an unacceptable number of women undergo invasive follow up testing. Additional screening tests are needed that combine a high sensitivity, a low false positive rate, and minimal or no risk to the fetus ...
Childrens Hospital of Pittsburgh of UPMCs electronic surveillance framework for hospitalized kids is poised to significantly reduce false-positive identification of serious health conditions.
FIV is diagnosed through blood tests that detect antibodies to the virus. The most common screening test is called an ELISA test (Enzyme Linked Immunosorbent Assay). If this test is positive it means that the cat has produced antibodies to the virus, and it is likely that your cat has been and still is infected by the virus. False positive and negative results do occur for a variety of reasons.. False positive results may occur if a cat has been vaccinated against FIV, since the antibody test does not differentiate between antibodies produced by the disease and vaccine-induced antibodies. Kittens born to an infected queen or female cat may receive maternal antibodies or antibodies to the virus that pass through the milk, giving a false positive test result. Kittens under four months of age that test positive should be re-tested when they are six months old, by which time any maternal antibodies will have disappeared.. It can take up to eight weeks for a cat to develop antibodies to FIV, so a ...
Emmanuel J. Favaloro, Giuseppe Lippi, Laboratory reporting of hemostasis assays: the final post-analytical opportunity to reduce errors of clinical diagnosis in hemostasis?, Clinical Chemistry and Laboratory Medicine, 2010, 48, ...
Guidance on creating procedures for false-positive cultures when developing a TB genotyping program. Provided by the Centers for Disease Control and Prevention (CDC).
INTRODUCTION: In a population-based study, we found an overall false-positive rate of 8.8% for the second and third trimester ultrasounds. Although numerous studies have been performed to examine factors which lead to false negatives, the same is not true for the factors associated with false positives. The principal objective of this study was to look for risk factors for false-positive diagnoses of fetal malformations on obstetric ultrasound scans. MATERIAL AND METHODS: In this nested case-control study, the case infants were those whose mother had a false-positive antenatal ultrasound diagnosis of a malformation during the second or third trimester (ultrasound false-positives) and who were live- or stillborn in Auvergne in 2006-2010 ...
Results of a new, large-scale study have revealed that adding 3D tomography to conventional 2D mammography increases cancer detection by as much as 40%, while lowering false-positive results by 15%. The study results published in the journal, Radiology, showed that adding 3D tomography increased detection rates for cancer, and reduced the number of false-positives, resulting in…
Piperacillin-tazobactam (PTZ) may cause false-positive leads to the Platelia enzyme-linked immunoassay (EIA), because of contaminants with galactomannan (GM). with piperacillin-tazobactam (PTZ) was initially reported in 2003, and four plenty of PTZ 1373423-53-0 IC50 found in these individuals included GM (4). Piperacillin can be produced like a fermentation item of molds from the genus (5). Because […]. Read More ». ...
The FDA is aware of reports of false-positive results associated with antigen tests used in nursing homes and other settings and continues to monitor and ...
Hello, Yes, it is possible that pregnancy or past pregnancy can cause nonspecific cross-reacting antibodies, which can in turn cause false-positive or indeterminate HIV-antibody screening tests. If...
Background: As an observational science, epidemiology is regarded by some researchers as inherently flawed and open to false results. In a recent paper, Boffetta et al. [Boffetta P, McLaughlin JK, LaVecchia C, Tarone RE, Lipworth L, Blot WJ. False-positive results in cancer epidemiology: a plea for epistemological modesty. J Natl Cancer Inst 100:988-995 (2008)] argued that epidemiology is particularly prone to the generation of false-positive results. They also said the tendency to emphasize and over-interpret what appear to be new findings is commonplace, perhaps in part because of a belief that the findings provide information that may ultimately improve public health and that this tendency to hype new findings increases the likelihood of downplaying inconsistencies within the data or any lack of concordance with other sources of evidence. The authors supported these serious charges against epidemiology and epidemiologists with few examples. Although we acknowledge that false positives ...
Accurate detection of homologous relationships of biological sequences (DNA or amino acid) amongst organisms is an important and often difficult task that is essential to various evolutionary studies, ranging from building phylogenies to predicting functional gene annotations. There are many existing heuristic tools, most commonly based on bidirectional BLAST searches that are used to identify homologous genes and combine them into two fundamentally distinct classes: orthologs and paralogs. Due to only using heuristic filtering based on significance score cutoffs and having no cluster post-processing tools available, these methods can often produce multiple clusters constituting unrelated (non-homologous) sequences. Therefore sequencing data extracted from incomplete genome/transcriptome assemblies originated from low coverage sequencing or produced by de novo processes without a reference genome are susceptible to high false positive rates of homology detection. Researchers at Brigham Young University
A ROC curve is a diagnostic plot that evaluates a set of probability predictions made by a model on a test dataset.. A set of different thresholds are used to interpret the true positive rate and the false positive rate of the predictions on the positive (minority) class, and the scores are plotted in a line of increasing thresholds to create a curve.. The false-positive rate is plotted on the x-axis and the true positive rate is plotted on the y-axis and the plot is referred to as the Receiver Operating Characteristic curve, or ROC curve. A diagonal line on the plot from the bottom-left to top-right indicates the curve for a no-skill classifier (predicts the majority class in all cases), and a point in the top left of the plot indicates a model with perfect skill.. The curve is useful to understand the trade-off in the true-positive rate and false-positive rate for different thresholds. The area under the ROC Curve, so-called ROC AUC, provides a single number to summarize the performance of a ...
Women who have a false-positive result on their mammogram may be at higher long-term risk of developing breast cancer than those whose initial test is negative,
I am attempting to enter the armed services, however up at meps (military entrance processing station), I was supposed to be signing contract which provides me with an amazing opportunity, I was told my urine screen came back positive for LSD, a drug that I have never been offered let alone imbibed. Now I didnt take any OTC meds or prescription medications 5 days prior to going in for my full physical/ drug screen because I am aware of the possibility for false positives. However, I recently quit taking my prescription of adderall xr 30 mg a week prior to the test, I dont see any chemical structure similarities between the metabolites produced by amphetamines and those produced by LSD, also given the fact that my screen only came up positive for LSD (no other pos. results except the one mentioned) I think this is not a factor on the test. Still though could this be a factor in my screen coming back positive for LSD ...
I tested + last week at my methadone clinic for cocaine-they were as shocked as I was because I have been clean of illegal drugs for 2 yrs this month and Ive never failed a drug test before for the last yr that Ive been with them. After questioning me on what I had recently taken-methadone, vicodin, relpax, phenergan, and Lidoderm 5% pain patch, they said it had to be the patch! A doctor about 2 yrs ago had given me a handful of samples and every now and then when I have a bad migraine I use them. Since he hadnt given me a prescription for them, they just made a copy of the packaging of a patch I had with me and put that and a notation in my chart that the patch can cause false positives and they put me on probation for a little while ...
Meta-analysis found RCM to be more sensitive but less specific for the detection of BCC in studies of participants with equivocal lesions (sensitivity 94%, 95% CI 79% to 98%; specificity 85%, 95% CI 72% to 92%; n = 3 studies) compared to studies that included any suspicious lesion (sensitivity 76%, 95% CI 45% to 92%; specificity 95%, 95% CI 66% to 99%; n = 4 studies), although confidence intervals were wide. At the median prevalence of disease of 12.5% observed in studies including any suspicious lesion, applying these results to a hypothetical population of 1000 lesions results in 30 BCCs missed with 44 false positive results (lesions misdiagnosed as BCCs). At the median prevalence of disease of 15% observed in studies of equivocal lesions, 9 BCCs would be missed with 128 false positive results in a population of 1000 lesions. Across both sets of studies, up to 15% of these false positive lesions were observed to be melanomas mistaken for BCCs. There was some suggestion of higher sensitivities ...
A false positive for amphetamines can be caused by taking medications or supplements like antidepressants, cold remedies, etc. Learn what to do if you get a false positive result.
Are you aware of the problems with whooping cough diagnosis? Do you know that the vaccine can potentially contaminate the environment and lead to false
If you need help using this information to become healthier, click here In Case You Missed It On Monday, we took a look at false positive test results for SIBO and how this is affecting patients attempting to clear SIBO. On Wednesdays podcast release, we covered some great tips for how to implement healthy diet and lifestyle changes with the coauthors of Eat well, Move Well, Live Well. Dr. Ruscios Weekly Tip This week we took an even deeper look at false positive SIBO test … [Read more...] ...
If youre not outraged,youre not paying attention!Read what Public Citizen has to say about the biggest blunders and outrageous offenses in the world of public health, published monthly in Health Letter.
Doctors give unbiased, helpful information on indications, contra-indications, benefits, and complications: Dr. Cohen on what is the cancer marker lab test cea something: The CEA (carcinoembryonic antigen) test is a colon cancer tumor marker. As with most tumor markers, it is not used as a screening test for colon cancer (in other words, it is not used to find the cancer because of a relatively high false positive rate) but it is used to monitor the cancer once it has been diagnosed. This is particularly useful for treated colon cancer to see if the tumor reoccurs.
Table 2 and 3 show that the coverage > 0.2 and E-value < 1e-23 combination gave the best F-measure for both Arabidopsis (F-measure = 0.91, sensitivity = 0.89 and precision = 0.92) and rice (F-measure = 0.85, sensitivity = 0.84 and precision = 0.85). We have also performed evaluation for the five classes separately, which suggests that the best F-measure varies for different CAZyme classes (Table 2 and 3). Overall the largest two classes GT and GH (81% of CAZyme families) in both plants have higher F-measures than the three smaller classes CE, PL and CBM. It also suggests that: (i) to annotate GH proteins, one should use a very relax coverage cutoff or the sensitivity will be low; (ii) to annotate CE families a very stringent E-value cutoff and coverage cutoff should be used; otherwise the precision will be very low because of a very high false positive rate ...
Hi Joerg, Thanks for your comments. Please see my replies inline. , Hi ! , , , Let me join here: , , Chuck Bell wrote: , , Hema, , , , , Above all, you need to fix the false positive test result , for falcon , , tests when no falcon engine exists. This is wrong. This , applies to all , , storage engines. If they arent there the test should not , say that the test passed. , , From a build team point of view, I very strongly support that: , , It is mandatory for us that exactly those tests are run which , check components (table handlers, collations, ...) configured , in the build, and tests for other components get skipped. , , For examples of this, please see the tests written by , Matthias Leich in the funcs1 suite, whose result files , differ by the engine tested: Hema: I went through the funcs_1 suite and noticed a separate test/result file for each storage engine, testing the same functionality. Unfortunately this was not approved by my team when I followed exactly the same method ...
U.S. minorities tend to receive fewer medical services considered effective like flu shots, aspirin following heart attack, study author says.
Notice something interesting here? There is a philosophical disagreement among DLP users about its primary mission. Those in camp #1 will focus on educating the users and using DLP as behavioral change amplifier. They will heavily rely on warning messages, notify/justify prompts and real-time education features (please dont email SSNs - here is a link to our approved secure data transfer facility). Of course, they will block the most blatant data violations, but will use the act of blocking as an educational opportunity as well. These people would celebrate when they see less attempts to send the data by the users rather than when they see more blocked attempts. Finally, they are well aware of the limits of automation, especially when complex and potentially ambiguous pieces of information need to be protected.. Those in camp #2 will focus on tuning the policies for more reliable automated blocking, low false positive rates and will seek out ways of triggering various automated actions ...
Women who have a false positive result on their mammogram may actually be at slightly higher risk of developing breast cancer over the following decade, according to a new study.
Precision is a measure of exactness - getting the same, reproducible result every time. Accuracy is a measure of attaining the correct answer. Precision without accuracy will provide reproducible results, however, they may not be correct. While accurate results without precision will average close to the correct answer they will be subject to increased false-positives and false-negatives.. Many clinical assays have been developed with the focus on providing reproducible analytical results; however, if the pre-analytical steps do not properly preserve the sample the results can be reproducible but will not provide the correct answer or will be hindered by unacceptable false-positives and false-negatives. To develop truly verifiable assays both precise and accurate pre-analytical sample preparation is required to attain precise and accurate analytical results.. Covaris systems are designed by engineers trained in developing in vitro and in vivo instrument systems. Covaris focused-ultrasonicators ...
Specificity: the probability that an individual without the disease will test negative. It is the number of patients who have a negative test and do not have the disease (true negatives) divided by the number of patients who do not have the disease. A test with high specificity will infrequently identify patients as having a disease when they do not (ie, low false positive results). Negative predictive value: the likelihood that a patient who has a negative test is free of the disease. February 14, 2007 ...
Specificity: the probability that an individual without the disease will test negative. It is the number of patients who have a negative test and do not have the disease (true negatives) divided by the number of patients who do not have the disease. A test with high specificity will infrequently identify patients as having a disease when they do not (ie, low false positive results). Negative predictive value: the likelihood that a patient who has a negative test is free of the disease. Posted by mmw at 02:10 PM , Comments (0) ...
I was just wondering how common is a false positive result for trichomonas, Would it be a routine test done 6 years ago during pregnancy
However, these tests arent useful for most people undergoing low risk procedures such as eye surgery or breast biopsy. Thats because the risk of heart complications from such operations is so low that its hard to do anything differently to lower it further. In fact, even major surgery is safe for most healthy people who feel well and are moderately active without symptoms. All they usually need is a medical history and physical exam.. The tests can pose risks!. Preoperative imaging tests are usually very safe and can be done with little or no radiation. But if youre unlikely to have a heart problem, they may produce false-positive results (indicating you have heart disease when you actually do NOT) that could prompt anxiety, additional risky testing, and a delay of your surgery. For instance, they might be followed up with coronary angiography (cardiac catheterization), a test that uses dye and X-rays to look at your heart vessels. While the risk from any one test may be acceptable, risks ...
While many products have dropped their false positive rate to a very low level, none can truthfully boast that they have no false positives. Products often claim to have a lower false positive rate than they really do because of the inherent errors in the reporting of false positives. People tend to ignore gray mail false positives (such as messages from mailing lists that are not technically spam), and there is generally a bias to under-report errors in a product that is otherwise very satisfactory.. From the webcast: Every virus scanner has three answers: yes, no and I dont know. You need to include in your strategy a plan for dealing with messages that might or might not have a virus in them. Some examples of messages that might show up as I dont know include encrypted e-mail, messages that cause the virus scanner to crash, or messages with archives that are not supported by the virus scanner or would otherwise exceed the time and space limitations in place for expanding e-mail. ...
Unfortunately I do not have any clear answers for you. Someone would need to review all your medical records to figure out if you had a false positive test for lupus or if you do have lupus. Lupus...
It has frequently been suggested that immediate test ordering in unexplained complaints is superfluous.[6-8] Since the pretest probability of serious pathology in patients with unexplained complaints is usually low, the risk of false-positive test results is relatively high. This may result in a chain of unnecessary further testing, which in turn might lead to patient anxiety, high costs, somatisation and a risk of serious side effects or even unnecessary morbidity.[9, 10] Applying a watchful waiting policy is recommended because the majority of these complaints are expected to be self-limiting. Patients in whom the complaints are not self-limiting will have a higher prior probability of having serious pathology, and the diagnostic accuracy of tests in this selected group is expected to be higher, because of the lower risk of false-positive test results.. We have found only one guideline on blood test ordering for unexplained complaints in general practice. This guideline, issued by the Dutch ...
article{f8408d0b-1483-466c-a428-b904b9c30791, abstract = {,p,Objectives: Heterophilic antibodies, such as rheumatoid factor (RF), are known to interfere with enzyme-linked immunosorbent assays (ELISAs). Treatment of rheumatoid arthritis (RA) with tumour necrosis factor (TNF)-α blockers is well established. The aims of this study were to develop a protocol for blocking the interaction of present heterophilic antibodies and to validate this procedure by evaluating the effect on correlations of cytokine levels to clinical response in RA patients treated with adalimumab. Method: Fourteen patients with active RA were evaluated at baseline and 3 months after starting adalimumab treatment. Cytokines were analysed with a commercial 12-plex bead ELISA. To block interference by RF, a commercial blocker (HeteroBlock) was used. To determine the optimal concentration of HeteroBlock, patient sera were analysed with different concentrations of HeteroBlock. Subsequently, baseline and follow-up sera from the 14 ...
Screening for colorectal cancer (CRC) and its precursors by fecal occult blood tests (FOBTs), which has been shown to reduce CRC incidence and mortality in randomized trials, is widely recommended and applied in an increasing number of countries. Screening is mostly done in age groups in which use of low-dose aspirin for primary or secondary prevention of cardiovascular disease is increasingly common. Use of low-dose aspirin increases the likelihood of gastrointestinal bleeding, especially upper gastrointestinal bleeding. Because of the increased risk of bleeding from sources other than colorectal neoplasms [tumors], concerns have been raised regarding possible adverse effects on specificity of FOBT-based screening for CRC, according to background information in the article. Potential false-positive test results due to increased risk of upper gastrointestinal bleeding are expected to be of less concern for increasingly available immunochemical FOBTs (iFOBTs; a type of test to check for blood in ...
Given the wide knowledge gaps in the evaluation of patients with low and intermediate pretest probability stable chest pain and the ubiquity of noninvasive imaging the below mentioned largest, most comprehensive and timely randomized clinical trials (RCTs), provide valuable insights into risk stratification, diagnosis, management, prognostication, and outcomes. Rapid clinical assessment of patients with low/intermediate-risk stable chest pain can identify high-risk individuals. However, about 33% of patients labeled as noncardiac chest pain die from cardiovascular disease or develop acute coronary syndrome (ACS) during 5 years follow-up. About 1.5% of patients with ACS are missed even after extensive testing leading to potential medical, legal, and psychological sequelae. As a result, clinicians have a low threshold to admit even low risk patients for prolonged expensive observation and testing leading to unnecessary admissions, false-positive test results, and unnecessary invasive downstream ...
Why is improving Wilsons disease diagnosis important?. Wilsons disease is an inherited disease that leads to a build-up of copper in affected parts of the body. Diagnosis usually occurs in children or young adults, but has been seen in adults over 60 years of age. Copper build-up begins in the liver progressing over time to affect the brain; however, the challenge for doctors is that liver disease in Wilsons disease has non-specific features and standard liver blood tests may be normal, even with advanced scarring of the liver or cirrhosis. Early diagnosis allows earlier treatment, however, other causes of chronic liver disease may cause false-positive results and, depending on cut-off values used for testing, may result in further unnecessary testing. Conversely, false-negative results may also arise when a single-test strategy for diagnosis is used, possibly leading to a delay in treatment.. What is the aim and what was included in this review?. We aimed to examine the accuracy of three ...
Of the 18,410 serum tests (17,058 immunoassays and 1,352 immunoblots) performed on 15,928 unique persons, 249/1,352 (18.4%) IgM immunoblots were positive. After excluding repeat tests, insufficiently documented cases, and subjects with a history of Lyme disease, 212 positive IgM immunoblot cases were assessed. A total of 113/212 (53.3%) were determined to be false positives. Antibiotics were prescribed for Lyme disease for 97/99 (98.0%) subjects with a true positive test and 91/113 (80.5%) subjects with a false positive test. The number of false positive cases reported to the surveillance system was identical to the number of unreported true positive cases (n=44) ...
If you want to follow my story and ramblings through the medical world, you need to start reading the oldest post first which is at the very bottom or you can jump to it by going to June 2007 and look for My Big Announcement. I started this blog so I could keep my friends and family up on my dealings with breast cancer but now it has evolved into my take on the medical world as well as my medical ups and downs. I have not listed my email address but if you know me, you know how to contact me. I always welcome emails. You can also find me on Twitter @carolinemfr and on Facebook. Otherwise, feel free to leave a comment ...
Brucellosis is a worldwide zoonotic disease transmitted to humans by consumption of contaminated milk and milk products. Brucellosis is endemic in Turkey, and Edirne has a high Brucella prevalence. Brucellosis is prevented by live-attenuated vaccines for animals and the vaccination program has been in place since 1984 in Turkey. Thrace is the pilot region for this vaccination program. The gold standard diagnostic technique for brucellosis is still the isolation of suspicious bacterial colonies followed by bacteriological identification, but it is very time consuming and laborious. In many studies, Brucella has been investigated by PCR techniques. However, PCR-based methods cannot differentiate between the vaccine strain and the virulent strain; thus, the vaccine strain may interfere with the virulent strain and causes false-positive reactions. To monitor brucellosis control programs effectively, it is important to distinguish vaccine and field strains of Brucella spp. In this study, raw milk ...
|p||strong|Background|/strong||/p| |p|There are several reports on underdiagnosis of COPD, while little is known about COPD overdiagnosis and overtreatment. We describe the overdiagnosis and the prevalence of spirometrically defined false positive COPD, as well as their relationship with overtreatment across 23 population samples in 20 countries participating in the BOLD Study between 2003 and 2012.|/p| |p||strong|Methods|/strong||/p| |p|A false positive diagnosis of COPD was considered when participants reported a doctors diagnosis of COPD, but postbronchodilator spirometry was unobstructed (FEV1/FVC > LLN). Additional analyses were performed using the fixed ratio criterion (FEV1/FVC < 0.7).|/p| |p||strong|Results|/strong||/p| |p|Among 16,177 participants, 919 (5.7%) reported a previous medical diagnosis of COPD. Postbronchodilator spirometry was unobstructed in 569 subjects (61.9%): false positive COPD. A similar rate of overdiagnosis was seen when using the fixed ratio criterion (55.3%). In a
SINGAPORE: Other laboratories are not using the same COVID-19 test kit and analytical instrument combination as a lab that had 33
Adding ultrasonography to screening mammography in women younger than 50 years at low, intermediate, or high breast cancer risk is not associated with an increase in breast cancer detection. It is associated with increased unnecessary biopsy recommendations and results in more frequent follow-up.
Chris was born in Chichester, on the South Coast of England. He received his BSc and MSc in Biochemistry from the University of Cambridge, UK. For his MSc, Chris investigated the role of TCF25 in the DNA damage response. He joined the DNA Replication Group in October 2017 as a PhD student to work on engineering replicative helicase variants to uncover novel roles in the S-phase of DNA replication. Outside of the lab, Chris enjoys competing in triathlons, rock climbing and hiking.. ...
A high proportion of women who received false-positive results on screening mammography reported experiencing psychosocial consequences, such as anxiety, s
A quick test, which is performed independently without the additional cover of a regular test may yield a false result. A false positive result may cause unnecessary and unjustified distress, whereas a false negative result may give the patient a false sense of security that s/he is not a carrier. Furthermore, in facilities recognized by the Ministry of Health there are skilled staffs capable of providing the patients with a correct interpretation of the results, as well as appropriate advice in cases where the outcome is a positive result. This notification is being published following a publication that appeared a few weeks ago, which claimed that the FDA had approved a quick test kit. The Ministry of Healths policy has been defined in the Director Generals special procedure Guidelines for Performing Tests for Monitoring Female HIV Carriers: a policy defining the special terms for performing laboratory HIV tests. The Ministry of Health recommends that the HIV tests be performed exclusively ...
The Tisbos approached me with the idea of helping the equestrian industry become more informed about EHV-1, said ESP CEO and WEP Managing Partner Mark Bellissimo. We think a grant to Gluck is a great first step and hope that with a Veterinary Committees assistance, we can start the conversation of getting universal protocols for the prevention and treatment of this disease. We want to make sure that all of the horses coming to our horse shows are healthy, but also help determine the best way to apply standard measures at events. We want to learn from our recent experience and not look back, but forward, in order to get the best from a bad situation.. With the instance of a false-positive test at Tequestrian Farms, the situation of dealing with incorrect information is one that the Tisbo family want to help others avoid. Tequestrian Farms was released from quarantine on March 4 by the State of Florida veterinarians when it was determined the horse in question had never tested positive for the ...
On May 30, 2019, I had the privilege to attend the CPHAZ symposium for my third year in a row and once again it did not disappoint. I find each year I gain a deeper understanding and appreciation for the information that is presented. The keynote speaker, Dr. Kirk Leifso, gave an enlightening presentation that explained some of the details surrounding Lyme disease and its diagnosis. Having studied blacklegged tick ecology for the past two years, Lyme disease and its various symptoms and diagnosis, was something I never fully understood. I now understand that currently the best testing methods are a serology test that looks for B. burgdorferi antibodies; however, this test is not completely accurate and still produces false negatives and false positives. Therefore, many individuals still go undiagnosed or misdiagnosed; false positive diagnoses may be treated for Lyme disease and thus not the treatment that they need to recover. As a pediatrician, Dr. Leifso showed us many cases of the symptoms ...
TY - JOUR. T1 - False-positive results with select HIV-1 NAT methods following lentivirus-based tisagenlecleucel therapy. AU - Laetsch, Theodore W.. AU - Maude, Shannon L.. AU - Milone, Michael C.. AU - Davis, Kara L.. AU - Krueger, Joerg. AU - Cardenas, Ana Maria. AU - Eldjerou, Lamis K.. AU - Keir, Christopher H.. AU - Wood, Patricia A.. AU - Grupp, Stephan A.. PY - 2018/6/7. Y1 - 2018/6/7. UR - http://www.scopus.com/inward/record.url?scp=85048431555&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=85048431555&partnerID=8YFLogxK. U2 - 10.1182/blood-2017-12-822940. DO - 10.1182/blood-2017-12-822940. M3 - Letter. C2 - 29669777. AN - SCOPUS:85048431555. VL - 131. SP - 2596. EP - 2598. JO - Blood. JF - Blood. SN - 0006-4971. IS - 23. ER - ...
Using retrospective medical record review as the gold standard, we searched for evidence supporting the presence of any of the five selected adverse events reported in the B-HDDS.. Except for pressure ulcer, all indicators had high NPVs (,96%) but very low PPVs (29.9% to 62.3%).. These results were generally consistent with prior research. The preliminary validation study of screens by Iezzoni et al found a sensitivity of 93% and a specificity of 64%.23 Lawthers and colleagues found that particularly medical screens were sensitive for the present-on-admission coding.24 The large drop in PPV for pressure ulcers in the present study supports this finding.. To understand the mismatches between medical record reviews and administrative data, the current study also provided a detailed analysis on all false-negative and false-positive cases by re-evaluating the medical records involved. The lack of specificity of the ICD-9-CM codes accounted for nearly 57% of false-positive cases for postoperative ...
A ROC curve is a graph that plots true positive rates against false positive rates for a series of cutoff values, or in other words, graphically displays the trade-off between sensitivity and specificity for each cutoff value. An ideal cutoff might give the test the highest possible sensitivity with the lowest possible false positive rate (i.e., highest specificity). This is the point lying geometrically closest to the top-left corner of the graph (where the ideal cutoff value with 100% sensitivity and specificity would be plotted). Picking the ideal cutoff score is, to some extent, dependent on the clinical context, that is the purpose for which the tool will be used. The area under an ROC curve can be used as an overall estimate of its discriminating ability and sometimes is expressed as accuracy. The area under the ROC curve is equal to the probability that a test correctly classifies patients as true positives or true negatives. Greater areas under the curve indicate higher accuracy. To ...
In addition to the above, the complexity of the phenomenon requires the use of research methodologies that can often imply significant bias or limitations.. The health setting has been identified as one of the best contexts in which IPV can be identified and studied, mainly because of accessibility to this population, and also because it has been demonstrated that women who have suffered violence or abuse make a greater use of health services than those who do not or have not suffered such an experience.24 25 For this reason, in recent years a great effort has been made to develop brief scales that can be easily administered by health personnel and women alike.. However, it should be noted that there is no scientific evidence of the benefits of universal screening for violence in the health setting.26 False positive test results, most common in low risk populations, may compromise the clinician-patient relationship. Additional possible harms of screening may include loss of contact with ...
In this study using real-world data from the largest single site hospital in England, parenteral antimicrobials were prescribed to six percent of patients attending the ED and 23 % of patients admitted to hospital. Blood cultures were obtained from less than one-third of patients who were treated with parenteral antimicrobials at emergency admission to hospital and a micro-organism was identified in just 12 % of patients who had a blood culture. More than half of all patients prescribed a parenteral antimicrobial were treated with the broad spectrum antibiotics co-amoxiclav or piperacillin-tazobactam.. Although the rate of pathogen detection by blood culture was low in our study, it is comparable to other studies conducted in the ED [6, 7]. There are many factors that can reduce the sensitivity of blood cultures such as collection of a low volume sample, poor sampling technique and prior treatment with antimicrobials, and a further problem is the rate of false positive tests through blood ...
The researchers didnt offer an explanation about why false-positive mammogram results appear to be linked to a slightly higher risk of invasive disease. Many experts think that the subtle changes suggested on the mammogram may be an early clue to cancer before actual cancer exists. Its also important to know that this association has been suggested in other studies. But the large number of women in the study and the length of follow-up add more evidence that the link between false-positive results and a somewhat higher risk of invasive disease actually exists. The power of this study to show the association is very strong, particularly when you combine it with the results of the other studies that have been done, said Richard Wender, M.D., chief of cancer control at the American Cancer Society, in an interview. I think we can now say with confidence that women who have had a previous false-positive mammogram are at somewhat higher risk for breast cancer. The researchers who did this study ...
Abstract: Objective Our objective is to use the area of the motor evoked potential (MEP) as a diagnostic tool for intraoperative radicular injury. Methods We analyzed the intraoperative neurophysiological monitoring data and clinical outcomes of 203 patients treated for dorsolumbar spine deformity. The decrease in amplitude was compared with the reduction in the MEP area. Results In 11 cases, new intraoperative injuries occurred, nine of them were lumbar radiculopathies. Our new criteria, a decrease MEP area of 70%, yielded a sensitivity and specificity of 1, since it detected all the radicular injuries, with no false positive cases. Using a 70% amplitude decrease criteria, we obtained a sensitivity of 0,89 and a specificity of 0,99. A lower threshold (65% amplitude reduction) yielded a higher number of false positives, whereas a higher threshold (75 and 80%) gave rise to a higher number of false negatives. Conclusions The measurement of the MEP area gave evidence to be more reliable and ...
Before I get to translating this to the PSA data, I want to say that I find the second paragraph in the Results section quite problematic. It tells me how many of the PSA tests were positive, how many screenings on average each man underwent, what percentage of those with a positive test underwent a biopsy, and how many of those biopsies turned up cancer. What I cannot tell from this is precisely how many of the men had a false positive test and still had to undergo a biopsy -- the denominators in this paragraph shape-shift from tests to men. The best I can do is estimate: 136,689 screening tests, of which 16.6% (15,856) were positive. Dividing this by 2.27 average tests per subject yields 6,985 men with a positive PSA screen, of whom 6,963 had a biopsy-proven prostate cancer. And here is whats most unsettling: at the cut-off for PSA level of 4.0 or higher, the specificity of this test for cancer is only 60-70%. What this means is that at this cut-off value, a positive PSA would be a false ...
Food allergies and allergy testing has gotten a lot of media attention as of late. Several articles have stated that common allergy tests could yield false positive results. This statement has led others to question the prevalence of food allergies and life threatening food allergies in particular.
TY - JOUR. T1 - Consequences of false-positive screening mammograms. AU - Tosteson, Anna N A. AU - Fryback, Dennis G.. AU - Hammond, Cristina S.. AU - Hanna, Lucy G.. AU - Grove, Margaret R.. AU - Brown, Mary. AU - Wang, Qianfei. AU - Lindfors, Karen K. AU - Pisano, Etta D.. PY - 2014. Y1 - 2014. N2 - IMPORTANCE False-positive mammograms, a common occurrence in breast cancer screening programs, represent a potential screening harm that is currently being evaluated by the US Preventive Services Task Force. OBJECTIVE To measure the effect of false-positive mammograms on quality of life by measuring personal anxiety, health utility, and attitudes toward future screening. DESIGN, SETTING, AND PARTICIPANTS The Digital Mammographic Imaging Screening Trial (DMIST) quality-of-life substudy telephone survey was performed shortly after screening and 1 year later at 22 DMIST sites and included randomly selected DMIST participants with positive and negative mammograms. EXPOSURE Mammogram requiring follow-up ...
30.172 Within the SNBTS, it was agreed at a meeting of the Co-ordinating Group on 19 February 1985 that no Transfusion Centre in Scotland would commence routine donation testing for HIV unilaterally under any circumstances, whatever pressures might be applied. It was hoped that there would be a Ministerial statement to the effect that testing would not be introduced for blood donations until the tests were likely to yield more accurate results.[293] The decision was noted at the meeting of SNBTS Directors which followed on 27 February 1985.[294]. 30.173 Abbott kits were available for evaluation in March 1985. At a meeting between the SNBTS Directors, Haemophilia Directors and the SHHD on 7 March 1985 dealing with AIDS, including heat treatment, Dr McClelland reported on plans for the new US screening tests for HIV antibodies to be evaluated on a UK basis.[295] He reported that, at that stage, there was deep concern about reports indicating a high proportion of false positive tests in the trials ...
functions to compute true and false positive rates TPR ,- function(d, th){ sum(d$signal==present & d$measurement,=th) / sum(d$signal==present)} FPR ,- function(d, th){ sum(d$signal==absent & d$measurement,=th) / sum(d$signal==absent)} # use all the sorted values are possible threshods thresholds ,- sort(d$measurement) roc ,- data.frame(y=sapply(thresholds, function(th){TPR(d,th)}), x=sapply(thresholds, function(th){FPR(d,th)}) ) ggplot(roc,aes(x,y))+geom_point()+theme_bw()+labs(y=fraction of signal present\nmeasurements ,= threshold\n(true positive rate), x=fraction of signal absent\nmeasurements ,= threshold\n(false positive rate))+geom_abline(intercept=0,slope=1,lty=2 ...
Text originally published in the Document Sharing Metadata Handbook) The FindDocuments query has 17 query parameters, but 7 of them play a critical role. These parameters are the critical few, especially for the initial query that performs the primary filtering (further discussed in Section 3.4) among all available documents for a patient that may be in the thousands with a mature deployment. This primary filtering optimizes the use of query to return the best possible results, avoiding missing any results that should be considered. This favors false-positives (results that are not desired), over false-negatives (missed results). The query results returned include full metadata for each entry found; local refinement of these results (see section 2.2 below) is used to further eliminate these false-positives. The other 12 parameters may also be used, but the effectiveness of these additional parameters in primary filtering is limited. See section 2.1.2 for further explanation. Here are the 7 ...
Currently, there is no evidence to demonstrate the efficacy of whole body CT screening in the early detection and improved management or clinical outcomes of any disease. CT scanning exposes individuals to potentially harmful levels of radiation; neither the benefits nor the risks of this method of screening have been adequately assessed in clinical trials. Furthermore, there is the potential of false positive findings that could result in unnecessary invasive and noninvasive testing, further compounding the health risks.. The American College of Radiologys (ACR) statement (2002) on whole body CT screening states:. The ACR, at this time, does not believe there is sufficient evidence to justify recommending total body CT screening for patients with no symptoms or a family history suggesting disease. To date there is no evidence that total body CT screening is cost efficient or effective in prolonging life. In addition, the ACR is concerned that this procedure will lead to the discovery of ...
Greater volume of mammograms interpreted and more years of experience were not associated with greater accuracy. However, greater volume was associated with higher sensitivity (more true positive results in women who had breast cancer) and lower specificity (more false positive results in women who did not have breast cancer) whereas more experience was associated with lower sensitivity and higher specificity. The authors conclude that increasing volume requirements for radiologists is unlikely to improve the interpretation of mammograms ...
Results The searches returned seven includable studies (7/4,423). Those using disease specific measures found that there could be enduring distress that lasted up to three years; the level of distress was related to the degree of invasiveness of the assessment. At three years the relative risks were, further mammography 1.28 (95% confidence interval 0.82 to 2.00), fine needle aspiration 1.80 (95% confidence interval 1.17 to 2.77), biopsy 2.07 (95% confidence interval 1.22 to 3.52). There was also an enduring impact for those put on early recall 1.82 (95% confidence interval 1.22 to 2.72), However, studies that used generic measures of anxiety and depression found no such impact up to three months after screening. The strongest evidence suggests that women with false-positive mammograms have an increased likelihood of failing to reattend for routine screening, relative risk 0.97 (95% confidence interval 0.96 to 0.98) compared to women with normal mammograms. No studies of women from different ...
In this study, our purpose was to investigate the role of gene polymorphisms in the promoter of the human BTC gene in type 2 diabetic patients. Because the promoter of the human BTC gene had not been well studied, we initially characterized about 2.3 kb of the 5′-flanking region of the human BTC gene in a pancreatic β-cell line. We then screened gene polymorphisms in this region and found that the G allele of the −226A,G polymorphism was more frequent in type 2 diabetic patients than in nondiabetic subjects. However, the possibility that this result is a false-positive finding should be considered, because the sample size of our case-control analysis is small and the P values obtained are modest (17). Therefore, we further investigated the effect of the −226A,G polymorphism on clinical profiles of patients and the functional properties of all polymorphisms identified. We first examined the relationship between the G allele of the −226A,G polymorphism and insulin secretion ability in ...
Mammograms may not make much difference. Yes, there has been about a 25 percent drop in breast-cancer death rates since 1990. But some researchers point to treatment-not mammograms-as being mainly responsible for the decline. Evidence comes from a study of three pairs of European countries: In each pair, mammograms were introduced in one country 10 to 15 years earlier than in the other. Yet mortality rates are virtually identical, indicating mammography hadnt made a difference. Further, mammograms, are not so great at detecting the most lethal forms of disease-a triple negative, for example-at a treatable phase. Aggressive tumors also tend to progress too quickly, cropping up between screenings.. • Unnecessary treatments can be harmful. According to a survey of randomized clinical trials involving 600,000 women around the world, for every 2,000 women screened annually over 10 years, 1 life is prolonged but 10 healthy women are given diagnoses of breast cancer and unnecessarily treated, ...
The paper addresses the very important topic of overdiagnosis of those cancers that would not have progressed had they not been treated, the implication being that people underwent unnecessary treatments. It also offers some insights into which subtype of lung cancer this most frequently occurs. While the authors present the frequency at 18%, it should be stressed that they note this was an upper limit resulting from limitations in the data they had available, and there are other reasons as well, such as making the distinction as to whether the cancer was found on the first round or during subsequent rounds, where the rates are very different. More importantly, they also provide supportive evidence that the extent of overdiagnosis in the context of a well-defined lifetime screening program would actually be in the range of 3%. As noted by the authors, it is important to stress potential risks and benefits to people interested in screening -- which we do routinely at Mount Sinai -- but this ...
The gene of interest directly causes production of protein(s) or RNA that produce a desired trait or phenotype, whereas markers (a DNA sequence or the morphological or biochemical markers produced due to that DNA) are genetically linked to the gene of interest. The gene of interest and the marker tend to move together during segregation of gametes due to their proximity on the same chromosome and concomitant reduction in recombination (chromosome crossover events) between the marker and gene of interest. For some traits, the gene of interest has been discovered and the presence of desirable alleles can be directly assayed with a high level of confidence. However, if the gene of interest is not known, markers linked to the gene of interest can still be used to select for individuals with desirable alleles of the gene of interest. When markers are used there may be some inaccurate results due to inaccurate tests for the marker. There also can be false positive results when markers are used, due to ...
Discussions over mammography screening began with the view that it does not reduce deaths from breast cancer. More recently this has changed to the view that it probably does reduce mortality but the size of the effect is unclear.1 This has led to the proposed review of breast cancer screening in the United Kingdom.2 According to Mike Richards, Englands cancer tsar, anyone who has published in this field will be excluded from the panel. However, surely it would be better to include some of the proponents and opponents, who are already aware of key features specific to cancer screening through many years of experience?. Most publications on mammography screening have examined the effects on mortality separately from harms, such as overtreatment and increased anxiety after a false positive result. One of the linked articles attempts to combine benefits and harms (doi:10.1136/bmj.d7627),3 and the other (doi:10.1136/bmj.d7017) provides an estimate of overdiagnosis (the proportion of women diagnosed ...
Heterophile abs. Abs in the samples against abs in the assay. Only way to remove is review your data and locate high false positives. Add into your sample buffer non-specific ab (IgG) of the species used as capture and detector in your system and check with the false positive. ,,use this buffer and pre-incubate the samples to bind up the heterophile ab,, Once the false positive is reduced or eliminated test a select few of your samples. Hopefully, the samples will line up according to the conentration you expect ...
Yes, protein in urine may give false positive results because they change the test result. Protein in urine shows positive since pregnancy test detects hCG, which is a protein-based hormone.. If you have a family history of preeclampsia or are at risk of the condition, talk to your doctor about it. Though proteinuria is an indicator of preeclampsia, it might also be asymptomatic sometimes. So never skip a urine test suggested by the doc, as that is the only way to diagnose it.. ...
Collection Container/Tube: Sterile vial. Submission Container/Tube: Plastic vial. Specimen Volume: 1 mL. Collection Instructions:. 1. Obtain aliquot from second collection vial.. 2. Immediately place aliquot on ice.. Additional Information:. 1. Specimens that have not been kept refrigerated, or which have been tested for other analytes previously, may give a false-positive result.. 2. Hemolyzed specimens will give false-positive results. Specimens should be centrifuged to remove any red cells before shipping. The test will be canceled if there is any level of hemolysis present.. ...
reside in the stomach, and may represent false positive results of 13C-UBT.4 Additionally, interpretation of the gray zone, of which the exact range is not defined, remains a controversial issue.. Various attempts have been suggested to overcome these limitations and to improve diagnostic accuracy. These modifications have contained dosage of labeled urea used, the collection time of breath samples, testing with or without fasting, type of test meal, cutoff value and equipment for measuring isotope enrichment.2 Numerous studies associated with the UBT technique and its methodology have been revealed. However, no standardized method of UBT has been confirmed.. In terms of the test meal, it remains debatable if a test meal is required for 13C-UBT, or which test meal is superior. Theoretically, test meals were introduced to increase accuracy of UBT by delaying gastric emptying and maximizing distribution of the substrate within the stomach thereby enhancing the contact area and time between the ...
They usually go something like this. We have a group of women between 40 and 49 years of age with no apparent risk factors for breast cancer. What is the risk-benefit balance for mammography screening in this specific age layer? One way to approach this is to take a hypothetical cohort of 1,000 women who fit this description and put it through a decision tree. The first decision node here is whether to perform a screening or not. What follows are limbs stretching out toward particular outcomes. Obviously, some of these outcomes will be desirable (e.g., saving lives), while some will be undesirable, ranging from worry about false positive results to unnecessary surgery, chemotherapy, radiation, and even death. Because these outcomes are so heterogeneous, we try to convert everything to monetary costs per quality of life (quality because there are outcomes worse than death, as it turns out). But what underlies all of these models is the mathematics derived from clinical studies, not pulled out of ...
Many diseases cause inflammation in the body, including infections, autoimmune conditions and cancers. Millions of inflammatory marker tests are done each year and rates of testing are rising. Although many of these tests will be done appropriately for different reasons, GPs are increasingly using them as a non-specific test to rule out serious underlying disease. Until now there has been no evidence about whether this is a good strategy. The study, published in the British Journal of General Practice today [Tuesday 18 June], found that the tests are not good at ruling out disease and that also false positive results are common, leading to more follow-on consultations, tests and referrals.. Using data from the Clinical Practice Research Datalink, the researchers analysed the records of 160,000 patients who had inflammatory marker tests in 2014 and compared these with the records of 40,000 patients who had not had the test.. Overall, 15 per cent of raised inflammatory markers were caused by ...
Initially, I had a blood test which revealed that my fasting blood sugar was 5.8 mmol/l last October. At that point, I had symptoms indicative of diabetes and my doctor referred me to a 2 hour glucose tolerance test. Having prepared for the test correctly by consuming a high carb diet for 3 days prior, the test revealed that I was negative. Yet I was still experiencing symptoms and subsequently had a couple more blood tests, 2 urine tests and another glucose tolerance test just to make sure. All tests revealed that I was negative for diabetes and bear in mind that I prepared for them correctly to avoid false positive results ...
TANGO infinity®, an automated immunohematology system, combines simplicity and convenience without sacrificing performance or security. Its unique package of safety features includes precise volume verification for every sample, control and reagent dispense, automatic on-board QC management, and sophisticated reagent on-board shelf life and critical processes monitoring. The Erytype® S and Solidscreen® II reagent lines for blood grouping and antiglobulin testing minimize false positive results yet provide the appropriate sensitivity to detect clinically significant antibodies and weak antigen types. The TANGO infinity® is the ideal system for accuracy, convenience and flexibility that laboratories require. ...
This resulted in false-positive reactions. The specificity of Mallein tests and the efficiency and potency of it are connected ... Although Mallein is the most commonly used form of testing for glanders, cross reactions were reported between Burkholderia ...
H2O The reaction is specific for glucose, as occurs in all enzymatic reactions, but it can provide some false positive results ... False-positive readings are obtained when the reaction does not take place under acidic conditions. Highly pigmented urine and ... False-positive reactions due to menstrual contamination may be seen. They also occur if strong oxidizing detergents are present ... detergents and antiseptics also cause false-positive readings. A false-positive trace reading may occur in specimens with a ...
False-positive reactions with enzyme-linked immunosorbent assay of Mycobacterium tuberculosis antigens in pleural fluid. J Med ... But culture need 6-8week with 10-20% false positive results. A rapid serological test for diagnosis, follow-up of disease ... as well as false negative reactions in malnourished children. BCG has been used as an antigen in EIAs in in vitro studies to ... The ELISA titer indicate the positive or negative result. The diagnosis of TB is most complicated. The routine diagnosis for TB ...
Older drivers expressed reduced accuracy, higher reaction times, and more false positive responses compared to younger drivers ... The reaction time to changes in the driver's peripherals is much slower than the reaction time to changes that occur towards ... Due to the fact that control personnel have delayed reaction because of change blindness, an interface design of computer work ... Stimulation of the superior colliculus improves performance and reaction time in the same way. However, recent research has ...
... most positive reactions in low-risk individuals are false positives. A false positive result may be caused by nontuberculous ... Vaccination with BCG may result in a false-positive result for many years after vaccination. False positives can also occur ... Another source of false positive results can be allergic reaction or hypersensitivity. Although rare, (about 0.08 reported ... A positive result indicates TB exposure. 5 mm or more is positive in An HIV-positive person Persons with recent contacts with a ...
Borst, A.; A. T. A. Box; A. C. Fluit (2004-03-09). "False-Positive Results and Contamination in Nucleic Acid Amplification ... These tags can be appended to gene specific primers for reverse transcriptase polymerase chain reaction (RT-PCR) experiments, ... Martel, Fatima; Dirk Grundemann; Edgar Schöig (2002-03-31). "A simple method for elimination of false positive results in RT- ... Since PCR is unable to distinguish between cDNA targets and genomic DNA contamination, false positives and/or erroneous ...
Beuhler M, Lee DC, Gerkin R (August 2004). "The Meixner test in the detection of alpha-amanitin and false-positive reactions ... but also yielded false positives for some compounds, such as psilocin. Capillary zone electrophoresis was also developed, but ... Diarrhea and cramps are the first symptoms, but those pass, giving a false sign of remission. Typically, on the 4th to 5th day ... ring closure by fluorocyclization between 6-hydroxytrytophan and cysteine was achieved by intra-annular Savige-Fontana reaction ...
"The Meixner test in the detection of alpha-amanitin and false-positive reactions caused by psilocin and 5-substituted ... A positive reaction of Schaeffer's test, which uses the reaction of aniline and nitric acid on the surface of the mushroom, is ... Agaricus placomyces and Agaricus xanthodermus produce false negative reactions. Sometimes referred to as "Schaeffer's reaction ... The test yields false positives for some compounds, such as psilocin. Melzer's reagent can be used to test whether spores are ...
... to avoid false positives". Methods. 27 (2): 114-20. doi:10.1016/S1046-2023(02)00062-2. PMID 12095268. Akey DT, Akey JM, Zhang K ... It is important to ensure that reaction parameters such as temperature and salt concentration are suitable to maintain the DNA ... resulting in false positive results for methylation. Only cytosines in single-stranded DNA are susceptible to attack by ... Thus, it is important to assess the amount of DNA degradation resulting from the reaction conditions employed, and consider how ...
A reversal in the order of the reagents being added may result in a weak-positive or false-negative reaction. VP is one of the ... The reaction was developed by Daniel Wilhelm Otto Voges and Bernhard Proskauer, German bacteriologists in 1898 at the Institute ... The other three tests include: the indole test [I], the methyl red test [M], and the citrate test [C]. VP positive organisms ... A cherry red color indicates a positive result, while a yellow-brown color indicates a negative result. The test depends on the ...
False-positive testing derives its name because the testing requires both a false and a positive reaction to authenticate a ... False-positive testing generally is a one time test because once done the results remain visible so while useful as part of a ... False-positive testing can also be done on documents other than currencies as a means to test their authenticity. With the ... The reaction and coloring varies depending upon the formulation. Banknotes, being a specially manufactured substrate, usually ...
... was shown to have fewer false positive reactions than the Wassermann test. Both of these early tests have been superseded by ... Although it had some false positive results, it was a major advance in the detection and prevention of syphilis.[citation ... One of the first supporters of mercury treatment was Paracelsus because it had positive effects on the Arabic treatment of ...
This ensures that no contaminating DNA from previous PCR reactions is present in the lab, which could otherwise generate false ... Suicide PCR is typically used in paleogenetics or other studies where avoiding false positives and ensuring the specificity of ... PCR is preceded by a reaction using reverse transcriptase, an enzyme that converts RNA into cDNA. The two reactions may be ... which should never have been used in any positive control PCR reaction, and the primers should always target a genomic region ...
... false-positive reactions can occur for a large number of reasons, the most common of which is other infections, both viral and ... Because of the issues with false positives, confirmation with a second treponemal test that is specific for T. pallidum ... This reaction is the foundation of "nontreponemal" assays such as the VDRL (Venereal Disease Research Laboratory) test and ... Additionally these tests may show false-negative when the patient's antibody titer is very high due to a hook effect (also ...
Improperly prepared tissue samples may give false positives. In research, this reaction is used to stain cells that were ...
... found that the test produced false positive reactions in response to a number of substances besides blood. [See: Marius ... The positive color test alone should not be interpreted as positive proof of blood. A negative result is generally proof of the ... In its reaction with hydrogen peroxide, the heme center of hemoglobin behaves as a peroxidase, reducing the peroxide to water. ... The Kastle-Meyer test has the same reaction with human blood as it does with any other hemoglobin-based blood, so a ...
... leading to false positive reactions in forward grouping. Cold agglutinins can usually be deactivated by warming the sample to ... Therefore, a line of red blood cells at the top of the column indicates a positive result. The strength of positive reactions ... People who have tested positive for an unexpected blood group antibody in the past may not exhibit a positive reaction on ... In ABO typing, a score of 3+ or 4+ indicates a positive reaction, while a score of 1+ or 2+ is inconclusive and requires ...
This may cause false positive reactions but an individual suffering from anxiety may also avoid real threats. This may explain ... Another description of anxiety is agony, dread, terror, or even apprehension.[15] In positive psychology, anxiety is described ... Anxiety is a worry about future events and fear is a reaction to current events. These feelings may cause physical symptoms, ... and suggested the possibility for positive resolution of anxiety through the self-conscious exercise of responsibility and ...
Hyperthermia Hypothermia Galactorrhoea Breast enlargement in either sex False-positive pregnancy tests Allergic reaction Fits ... high blood pressure A dangerous skin reaction An autoimmune reaction A potentially fatal collection of symptoms (i.e. syndrome ... erection Fear of light A reduction in the normal homeostatic breathing reaction to reductions in plasmacarbon dioxide levels ... Impaired thermoregulation Hyperglycaemia Other hypothalamic abnormalities Blurred vision Confusion Raised ANA titre Positive ...
The Palestinian reaction has been very positive, according to Riklis. He expected a far more positive reception in Israel given ... Riklis has said that Israelis have the "false impression" that the film is pro-Palestinian and polemical. ... The film performed poorly with Israeli audiences despite the positive reaction in other areas. ... The website's critical consensus states that the film is "A positive and personal Israeli film that offers an understated and ...
... and false positive Coombs test. Cefaclor has also been reported to cause a serum sickness-like reaction in children. Cefaclor ... Allergic reactions may present as, for example, rashes, pruritus (itching), urticaria, serum sickness-like reactions with ... false positive urinary glucose (if tested for reducing substances) ... Gram positive aerobes - Staphylococci (including coagulase-positive, coagulase-negative, and penicillinase-producing strains), ...
... to minimize false-positives, especially when system is configured to perform autonomous reaction on the suspicious events. ... ACARM-ng (Alert Correlation, Assessment and Reaction Module - next generation) is an open source IDS/IPS system. ACARM-ng is an ... A trigger provides an abstraction of the reporting and reaction mechanism. Triggers by design, are not allowed to change the ... Typical use is real-time reporting of suspicious events to administrators (for example via e-mail) and automatic reaction to ...
... erythema of 15 millimeters is considered positive with a false positive ratio ([100 x {number of individuals with a positive ... suggest that the reactions are due to classical allergic reaction to allergens in the beverage; reactions to all or most types ... Questionnaires can be devised to determine the specific types of alcoholic beverages eliciting reactions; reactions evoked by ... alcohol-induced rhinitis and exacerbations of asthma reactions are highly associated with aspirin-induced asthma reactions; ...
... and their allergic reaction, if any, measured. 15% of guinea pigs must show a reaction for the test to be considered positive. ... 20 animals would typically be used to ensure against false negative results. The OECD Guidelines for the Testing of Chemicals ... along with an adjuvant to enhance the immune reaction of the guinea pig. During Induction B, the topical induction, the test ...
... false positive results are also common. Being a type I hypersensitivity reaction, anaphylactic reaction tray must be kept ready ... The test is positive in about 90% of cases of hydatid disease affecting the liver, but positive in less than 50% of patients ... A wheal response occurring at the injection site within 20 minutes is considered positive (immediate hypersensitivity). Delayed ...
Such reactions to non-visual stimuli are a widespread cause of false positives and false negatives when pet owners test their ...
He was well aware that injected hCG could trigger a false positive on a pregnancy test, but thought that the dosages he ... In fact, these patients were never pregnant, and the bodily changes were a reaction to the hCG. The pregnancy tests were ... inevitably false positives because the tests determined pregnancy by the presence of hCG. During Jacobson's criminal trial, ... He offered these explanations: With regard to the "false pregnancy" cases, he had believed that the women had actually been ...
False positives may also appear on tests used past their expiration date. False positive pregnancy test can happen due to ' ... Spurious evaporation lines may appear on many home pregnancy tests if read after the suggested 3-5 minute window or reaction ... False positive pregnancy test results are rare and may occur for several reasons, including: user error in performing and ... False positives can also be caused by (in order of incidence) quiescent pregnancy, pituitary sulfated hCG, heterophilic ...
... of the flocculation reaction without the need of a microscope.Many other medical conditions can produce false positive results ... The MHA-TP is used to confirm a syphilis infection after another method tests positive for the syphilis bacteria. The MHA-TP ... which may be used to confirm a positive VDRL result, are more specific for syphilis than non-treponemal tests and in the ... and pinta and possibly nonpathogenic commensal treponemes can result in a positive. Not all these disease are venereal; it has ...
Biological false-positive tests comprise a high proportion of Venereal Disease Research Laboratory reactions in an analysis of ... were biological false positive. BFP reactivity was found in 0.24% of all patients and was significantly higher in women than in ... a phenomenon referred to as biological false-positive (BFP) VDRL test. The aim of this study was to determine the frequency of ... 2 dilutions without a positive treponemal test was not reported. The subgroup of HIV-positive patients (n = 1415) revealed a 10 ...
Reactions,to,false-positive,prostate,cancer,screenings,assessed,medicine,medical news today,latest medical news,medical ... Men who get a false-positive prostate cancer result -- an abnormal s...The study findings based on telephone surveys of 210 men ... Men with false-positives were about three times as likely to report being at least somewhat worried about getting prostate ... Men who get a "false-positive" prostate cancer result -- an abnormal screening test followed by a biopsy indicating no evidence ...
... and the positives found are generally false positives, partly due to the high immunoglobulin concentration. ... False positive reactions for IgA and IgG anti-tissue transglutaminase antibodies in liver cirrhosis are common and method- ... and the positives found are generally false positives, partly due to the high immunoglobulin concentration. ... The largest number of false positives was found with methods that used tTG in association with gliadin peptides as antigen ...
false-positive reaction answers are found in the Tabers Medical Dictionary powered by Unbound Medicine. Available for iPhone, ... reaction. Accessed July 6, 2020.. False-positive reaction. (2017). In Venes, D. (Ed.), Tabers Medical Dictionary (23rd edition ... reaction. False-positive Reaction [Internet]. In: Venes D, editors. Tabers Medical Dictionary. F.A. Davis Company; 2017. [ ... false-positive reaction is a topic covered in the Tabers Medical Dictionary. To view the entire topic, please sign in or ...
FALSE-POSITIVE REACTION TO THE REGITINE TEST FOR PHEOCHROMOCYTOMA: REPORT OF A CASE1 Annals of Internal Medicine; 41 (5): 1061- ... ON THE IMPORTANCE OF MALARIA AS A CAUSE OF FALSE POSITIVE SEROLOGIC REACTIONS1. Ann Intern Med. ;19:651-655. doi: 10.7326/0003- ... ON THE IMPORTANCE OF MALARIA AS A CAUSE OF FALSE POSITIVE SEROLOGIC REACTIONS1 T. R. DAWBER, M.D. ... THE INCIDENCE AND ETIOLOGIC BACKGROUND OF CHRONIC BIOLOGIC FALSE-POSITIVE REACTIONS IN SEROLOGIC TESTS FOR SYPHILIS: ...
My initial reaction was that it probably wouldnt have been obvious, had I not had the instructions. It seemed like I was ...
... showed biological false-positive reactions.. There were 80 sera from blood donors which gave biological false-positive ... Sixty-six of the sera showed chronic biological false-positive reactions. Some donors were only found reactive for the first ... Chronic biological false-positive reactions to serological tests for syphilis in blood donors ... Chronic biological false-positive reactions to serological tests for syphilis in blood donors ...
Objectives Biologically false positive (BFP) reactions are well described in early literature. However, only a few recent ... Prevalence and clinical characteristics of patients with biologically false-positive reactions with serological syphilis ... Prevalence and clinical characteristics of patients with biologically false-positive reactions with serological syphilis ... Conclusion There was a low incidence of BFP reactions in the last decade. A minority of BFP reactions had high non-treponemal ...
More positive about mammography - reactions of women to a false positive recall: a qualitative study of women at risk of ... and sought to understand the reactions of women who had received an initial all-clear result and who had received an all-clear ... women who were recalled for further tests prior to an all-clear result reported significantly more positive feelings post ... ability of mammography to detect a cancer at an early stage gave reassurance that a cancer diagnosis could lead to a positive ...
... are likely to generate false positive results. Based on electronic searches in six databases, 13 studies were found that met ... are likely to generate false positive results. Based on electronic searches in six databases, 13 studies were found that met ... design is prone to false positive results and discuss the design features that might prevent or exacerbate this problem. ... design is prone to false positive results and discuss the design features that might prevent or exacerbate this problem. ...
"False Positive Reactions". 0-9. A. B. C. D. E. F. G. H. I. J. K. L. M. N. O. P. Q. R. S. T. U. V. W. X. Y. Z. * 0-9 ...
False Positive Reactions. False positive tuberculin reactions can occur in individuals who have been infected with other ... Negative Reactions. An individual who does not show a positive reaction to 5 TU on the first test, but is suspected of being TB ... False-Negative Reactions. Not all infected persons will have a delayed hypersensitivity reaction to a tuberculin test. ... Persons showing positive tuberculin reactions should be considered positive by current public health guidelines and referred ...
False Positive Reactions. False positive tuberculin reactions can occur in individuals who have been infected with other ... False positive or false negative tuberculin skin test reactions may occur in some individuals. (See Interpretation of the Test ... False positive tuberculin reaction tests occur in individuals who have been infected with other mycobacteria, including ... Negative Reactions. An individual who does not show a positive reaction to 5 TU on the first test, but is suspected of being TB ...
Elimination of false-positive polymerase chain reaction results resulting from hole punch carryover contamination ... 2008) Elimination of false-positive polymerase chain reaction results resulting from hole punch carryover contamination. ... It was determined that false-positive results could be obtained at least 13 times after a positive sample. Subsequently, the ... causing false-positive results by PCR. In the present study, filter-paper-collected blood that contained beak and feather ...
Association of Biologic False-Positive Reactions for Syphilis with Human Immunodeficiency Virus Infection. / Rompalo, Anne M.; ... Rompalo, A. M., Cannon, R. O., Quinn, T. C., & Hook, E. W. (1992). Association of Biologic False-Positive Reactions for ... Rompalo, Anne M. ; Cannon, Robert O. ; Quinn, Thomas C. ; Hook, Edward W. / Association of Biologic False-Positive Reactions ... Rompalo, AM, Cannon, RO, Quinn, TC & Hook, EW 1992, Association of Biologic False-Positive Reactions for Syphilis with Human ...
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False Positive Reactions. *Functional genomics. *GSK461364. *Gene Expression. *Gene Expression Regulation. *Genetic ...
The test was highly specific, no false positive reactions occurred with human faecal samples and the test was capable of ...
Brucella melitensis B115-Based ELISA to Unravel False Positive Serologic Reactions in Bovine Brucellosis: A Field Study ... Brucella melitensis B115-Based ELISA to Unravel False Positive Serologic Reactions in Bovine Brucellosis: A Field Study ... All positive sera, i.e. from Brucella-infected animals, were RBPT positive and CFT positive (ICFTU ranging from 20 to 1280) and ... All positive sera, i.e. from Brucella-infected animals, were RBPT positive and CFT positive (ICFTU ranging from 20 to 1280) and ...
This resulted in false-positive reactions. The specificity of Mallein tests and the efficiency and potency of it are connected ... Although Mallein is the most commonly used form of testing for glanders, cross reactions were reported between Burkholderia ...
9 in occurrence of false positive serological reactions - Polish Journal of Veterinary Sciences ... 9 in occurrence of false positive serological reactions. M. Weiner; K. Szulowski; W. Iwaniak ... The porcine brucellosis - evidence of the role of Yersinia enterocolitica O:9 in occurrence of false positive serological ...
Phenolphthalein false-positive reactions from legume root nodules.. Petersen D, Kovacs F. ...
H2O The reaction is specific for glucose, as occurs in all enzymatic reactions, but it can provide some false positive results ... False-positive readings are obtained when the reaction does not take place under acidic conditions. Highly pigmented urine and ... False-positive reactions due to menstrual contamination may be seen. They also occur if strong oxidizing detergents are present ... detergents and antiseptics also cause false-positive readings. A false-positive trace reading may occur in specimens with a ...
The frequency and identification of false positive conversion reactions. J Nerv Ment Dis 1979;167:243-247. ... Diagnosed conversion reactions: predicative value of psychiatric criteria. JAMA 1966;197:530-534. ... Neurologists should be encouraged to make a positive diagnosis early to avoid uncertainty in the minds of the patients, and ... Prognosis and differential diagnosis of conversion reactions. Dis Nerv System 1962;23:623-631. ...
False-positive reverse transcriptase polymerase chain reaction screening for SARS-CoV-2 in the setting of urgent head and neck ... False-positive reverse transcriptase polymerase chain reaction screening for SARS-CoV-2 in the setting of urgent head and neck ... False-positive reverse transcriptase polymerase chain reaction screening for SARS-CoV-2 in the setting of urgent head and neck ... T1 - False-positive reverse transcriptase polymerase chain reaction screening for SARS-CoV-2 in the setting of urgent head and ...
False Positive Reactions Citation: Farideh Zaini ,A. S. A. Mehbod , The puzzle of the false positive reaction in Cr ... The puzzle of the false positive reaction in Cr neoformanses capsular antigen slide latex agglutination test by sera of ... The puzzle of the false positive reaction in Cr neoformanses capsular antigen slide latex agglutination test by sera of ... Different examination have shown that rheumatoid factor is not responsible for false positive reaction [F. P. R. ] in Cr. ...
... and Gram positive bacteria cocci, showed false positive reaction by the BCG marker. the authors discuss the use of the ... False positive reaction of the immunohistochemistry technique using anti-BCG polyclonal antibodies to identify Mycobacterium ... False positive reaction of the immunohistochemistry technique using anti-BCG polyclonal antibodies to identify Mycobacterium ...
False Positive Reactions. Humans. Image Processing, Computer-Assisted*. Sensitivity and Specificity. Solitary Pulmonary Nodule ... RESULTS: The system provided a sensitivity of 94% for nodule detection and an average of 1.25 false-positive results per case. ...
False Positive Reactions. Hematologic Tests*. Humans. Infant, Newborn. Infant, Premature, Diseases / blood, diagnosis, etiology ... 16.5%; P , 0.001). On the initial test a positive screen (scores , or = 3) identified 26 of 28 infants with sepsis or probable ... infection (sensitivity 93%; specificity 82%; positive and negative predictive values 50 and 98%, respectively). Corresponding ...
  • To evaluate false-positivity and specificity, 54 HIV false-positive and HIV-negative serum samples from 100 hospitalized patients and 600 healthy subjects were included. (curehunter.com)
  • Raising temperatures or shaking speeds accelerated RT-QuIC reactions without compromising specificity. (mdpi.com)
  • The Venereal Disease Research Laboratory (VDRL) test for syphilis screening may, under certain circumstances, yield positive results in patients not infected with Treponema pallidum, a phenomenon referred to as biological false-positive (BFP) VDRL test. (nih.gov)
  • The seroprevalence for syphilis was 1.77% (n = 5320), as determined by a positive TPHA test. (nih.gov)
  • In a low syphilis prevalence population, BFP reactions comprise a high proportion of all VDRL reactors. (nih.gov)
  • The evaluation of positive serologic tests for syphilis is a problem which every physician must face. (annals.org)
  • Problem sera from 375 blood donors were investigated for biological false-positive reactions to serological tests for syphilis. (bmj.com)
  • Of the sera 49·9% were found to be non-reactive in all five tests, 28·8% gave results indicating a diagnosis of syphilis, and 21·3% showed biological false-positive reactions. (bmj.com)
  • It is concluded that sudden blood loss, as in blood donation, appears to stimulate the production of excess reagin in certain individuals, causing a chronic biological false positive reaction to serological tests for syphilis. (bmj.com)
  • We reviewed the serological test results of patients tested for syphilis in our hospital in the past decade and described the clinical characteristics of patients with BFP reactions. (bmj.com)
  • The prevalence of biologic false-positive (BFP) reactions for syphilis (reactive rapid plasma reagin [RPR] test, nonreactive fluorescent treponemal antibody absorption [FTA-ABS] test) among patients attending two sexually transmitted disease (STD) clinics was evaluated to assess relationships between BFP reactions and human immunodeficiency virus (HIV) infection. (elsevier.com)
  • Although more common among HIV-infected than HIV-uninfected patients, BFP reactions are relatively rare among STD clinic patients, and 89% of patients with reactive RPR or VDRL serologic tests for syphilis had current or prior syphilis infection. (elsevier.com)
  • False positive serologic reactions for syphilis: due to smallpox vaccinations (vaccinia). (springer.com)
  • Koike T, Sueishi M, Funaki H, Tomioka H, Yoshida S. Anti-phospholipid antibodies and biological false positive serological test for syphilis in patients with systemic lupus erythematosus. (springer.com)
  • The interpretation of syphilis tests is further complicated by the lack of a reliable gold standard for syphilis diagnostics, and the newer tests can result in false-positive reactions similar to those seen with older tests. (asm.org)
  • Of 2,214 samples that were retested, 203 (9.2%) had active syphilis infection, 21 (0.9%) were biological false reactions, 640 (28.9%) were past or treated syphilis infections, and 1,350 (61%) were uninfected. (biomedcentral.com)
  • 0.001), and had low positive predictive value (16.8%) for detecting active syphilis infection. (biomedcentral.com)
  • More than half (51.9%) of HSS syphilis positive cases were actually past/treated treponemal infections, possibly previous exposure to yaws. (biomedcentral.com)
  • The results of the various methods of assaying anti-tTG antibodies in patients with LC are highly variable, and the positives found are generally false positives, partly due to the high immunoglobulin concentration. (nih.gov)
  • IFAT reveals the earliest positive results for IgM antibodies after initial infection. (medscape.com)
  • In a large study of 494 patients with infectious mononucleosis, 79% of cases were due to EBV, and, in the 73 heterophile antibody-negative patients, approximately half of these were CMV positive (rising complement-fixing antibodies). (medscape.com)
  • I have read that sometimes false positive reflect a reaction to other (non-HIV) antibodies. (thebody.com)
  • This would probably mean that the blood that is negative when diluted but positive when undiluted has a lower level of antibodies than the diluted blood that is doubly positive and, therefore, may probably test negative on the Western blot test. (whale.to)
  • Participants were selected should respond, regardless of the test used, be it from five Voluntary HIV Counselling Testing (VCT) negative (absence of specific anti-HIV antibodies) or sites at the health centres of Neema and Boyoma in positive (presence of specific anti-HIV antibodies). (who.int)
  • If the patient has antibodies to T. pallidum , a color reaction takes place. (cdc.gov)
  • On each serum a cardiolipin Wassermann reaction, a Venereal Disease Research Laboratory test, a Reiter protein-complement fixation test, a Treponema pallidum immobilization test, and a fluorescent treponemal antibody absorption test were performed. (bmj.com)
  • Systemic toxic reactions are usually associated with much higher serum levels (30 to 40 mg/100 ml). (drugs.com)
  • Hepatic Cirrhosis Showing False-Positive Serum C-Reactive Protein Reaction. (nii.ac.jp)
  • A false-positive test has been reported with serum sickness ( CID 1999;29:953). (lww.com)
  • Positive and negative control serum specimens are run simultaneously to allow identification of viral proteins. (cdc.gov)
  • This reality was recently mentioned by an internationally-famous virologist from Germany, in an interview where he also admitted that laboratory confirmation of COVID-19 is next to impossible given the high incidence of both false-positive COVID PCR swab tests and false positive COVID serum antibody tests. (lewrockwell.com)
  • Recombinant EryC, Omp16, PP26, and PP39 were all reactive to B. abortus-positive serum. (mendeley.com)
  • false-positive serum or urine creatinine w/ Jaffe' reaction. (mims.com)
  • The reactivity of positive samples should be confirmed by the complement fixation test or by enzyme-linked immunosorbent assay (ELISA), both of which can also be used for both screening and confirmation. (fao.org)
  • False-positive reactions with enzyme-linked immunosorbent assay of Mycobacterium tuberculosis antigens in pleural fluid. (wikipedia.org)
  • Persons showing positive tuberculin reactions should be considered positive by current public health guidelines and referred for further medical evaluation. (drugs.com)
  • Characteristically, delayed hypersensitivity reactions to tuberculin begin at 5 to 6 hours, are maximal at 48 to 72 hours and subside over a period of days. (nih.gov)
  • Clinically, a delayed hypersensitivity reaction to tuberculin is a manifestation of previous infection with M tuberculosis or a variety of non-tuberculosis bacteria. (nih.gov)
  • Allergy to any component of TUBERSOL or an anaphylactic or other allergic reaction to a previous test of tuberculin PPD is a contraindication to the use of TUBERSOL. (nih.gov)
  • The only evidence of infection may be a reaction to a tuberculin skin test. (cdc.gov)
  • Health-care agencies or other facilities should consult with the local health department before starting a skin-testing program to ensure that adequate provisions are made for the evaluation and treatment of persons whose tuberculin skin tests are positive. (cdc.gov)
  • The tuberculin reaction was first described by Robert Koch in 1890. (wikipedia.org)
  • However, the test was unreliable due to impurities in tuberculin which tended to cause false results. (wikipedia.org)
  • TST (tuberculin skin test) positive is measured by size of induration. (wikipedia.org)
  • A positive Mantoux tuberculin skin test is the hallmark of tuberculous infection, meaning that the person harbors M tuberculosis within the body. (healio.com)
  • If the individual with a positive tuberculin skin test has a negative chest radiograph, a normal physical examination, and no symptoms, he or she has tuberculous infection without disease and, usually, is a candidate for isoniazid therapy. (healio.com)
  • In general, a child with a positive Mantoux tuberculin skin test who has any radiographic or clinical manifestations consistent with tuberculosis is considered to have tuberculous disease, even if no symptoms are present. (healio.com)
  • The tuberculin skin test is based on the fact that infection with M. tuberculosis bacterium produces a delayed-type hypersensitivity skin reaction to certain components of the bacterium. (medicinenet.com)
  • Reaction in the skin to tuberculin PPD begins when specialized immune cells, called T cells, which have been sensitized by prior infection, are attracted by the immune system to the skin site where they release chemical messengers called lymphokines. (medicinenet.com)
  • It is only contraindicated in people who have had a severe reaction to a previous tuberculin skin test. (medicinenet.com)
  • Two false positive reactions did occur in the CF test. (ajtmh.org)
  • Systemic reactions, such as hand dermatitis or generalized eczematous reactions, can occur due to dietary nickel or cobalt ingestion. (hindawi.com)
  • With nontreponemal tests, false-positive reactions can occur because of pregnancy, autoimmune disorders, and infections. (aafp.org)
  • So false NEGATIVES may occur. (koivet.com)
  • Cross reactions and false positives may occur. (koivet.com)
  • Cross-reactions with false-positive results may occur with B. fragilis, Pseudomonas species, Stenotrophomonas and Flavobacterium. (lww.com)
  • However, false positive reactions can occur so results must be interpreted with the utmost caution. (novusbio.com)
  • Adverse drug reactions (ADRs) remain a common and major problem in healthcare. (hindawi.com)
  • Severe cutaneous adverse drug reactions (SCARs), such as Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) with mortality rate ranges from 10% to more than 30%, can be life threatening. (hindawi.com)
  • In rare cases, some drugs are capable of inducing immune responses through interactions with MHC molecules, known as adverse drug reactions (ADRs). (hindawi.com)
  • Always send more than one fish, because among a group, there will be false negatives. (koivet.com)
  • Niven's medium ( 48 ) has been most widely used, although high rates of false positives and false negatives are observed, presumably due to the presence of competing bacteria ( 12 , 25 , 39 ). (asm.org)
  • All of these tests have been reported to provide positive results in more than 95% of the sera from infected humans. (medscape.com)
  • The collection of biological material (e.g., blood) directly onto filter paper for subsequent use in laboratory assays such as polymerase chain reaction (PCR), has become a common practice. (edu.au)
  • Background: No reports describe falsepositive reverse transcriptase polymerase chain reaction (RT-PCR) for novel coronavirus in preoperative screening. (elsevier.com)
  • The recently developed polymerase chain reaction (PCR) and DNA-probe methods provide additional means of detection. (fao.org)
  • This is 'Polymerase Chain Reaction' testing in which tissues are homogenized and then a probe is used to find tiny bits of the virus DNA. (koivet.com)
  • Virus can be detected in the blood for 1-2 weeks by nucleic acid tests such as polymerase chain reaction. (bmj.com)
  • We would reduce by two-thirds the number of expensive, stressful oral food challenges conducted, as well as saving children from experiencing allergic reactions. (upi.com)
  • The method, however, carries a risk of severe, life-threatening allergic reaction, in addition to false-positive results. (upi.com)
  • If we relied on them alone, we'd be over diagnosing food allergies -- only 22 percent of school-aged children in the U.K. with a positive test to peanuts are actually allergic when they're fed the food in a monitored setting. (upi.com)
  • The new test concentrates on mast cells, which help trigger allergic reactions. (upi.com)
  • They recognize an antibody called immunoglobulin in plasma and, in allergic patients, produce biomarkers associated with allergic reactions. (upi.com)
  • Parents are often afraid to feed them a food that is known to cause allergic reactions. (upi.com)
  • To identify the concentration of the fragrance compound hydroxyisohexyl 3-cyclohexene carboxaldehyde (INCI) (HICC) that is sufficiently low not to cause an allergic reaction in patients with proven sensitization. (labome.org)
  • Men who get a "false-positive" prostate cancer result -- an abnormal screening test followed by a biopsy indicating no evidence of cancer -- appear more likely to worry about their subsequent risk of cancer and report more problems with sexual function compared to men with normal screening results, according to a University of Iowa study. (bio-medicine.org)
  • In this article, we test the hypothesis that randomized clinical trials of acupuncture for pain with certain design features (A + B versus B) are likely to generate false positive results. (isharonline.org)
  • They all suggested that acupuncture is effected (one only showing a positive trend, all others had significant results). (isharonline.org)
  • We conclude that the 'A + B versus B' design is prone to false positive results and discuss the design features that might prevent or exacerbate this problem. (isharonline.org)
  • The use of a common cutting instrument for excising a standard-sized piece of paper that contains the material also introduces the potential for transferring biological material from one sample to subsequent samples, causing false-positive results by PCR. (edu.au)
  • It was determined that false-positive results could be obtained at least 13 times after a positive sample. (edu.au)
  • This method was simple, cheap, and relatively rapid, and allowed for the use of a single hole punch for a series of samples, without carryover contamination and consequent false-positive results. (edu.au)
  • Four (9.3%) had discrepant results (positive/negative). (elsevier.com)
  • RESULTS: The system provided a sensitivity of 94% for nodule detection and an average of 1.25 false-positive results per case. (biomedsearch.com)
  • Blood cultures have positive results in 100% of patients with acute-phase illness, but only 40-50% in those with chronic illness. (medscape.com)
  • Test results are positive in approximately 50% of individuals. (medscape.com)
  • Only 34 of the 54 (63%) samples known to yield false-positive results by EHIV assay had repeatedly yielded reactive results in the CHIV assay. (curehunter.com)
  • False-negative ratio refers to the ratio of subjects affected by an illness whose test results wrongly suggest they are disease free to all those subjects who have the disease. (ebscohost.com)
  • They work well for screening blood transfusions and identifying people who need further tests, but are known to yield false positive results due to serological cross-reactivity (or to inadequate quality control and human error (e.g. mislabeling of specimens). (plos.org)
  • Preliminary urine screening results, when positive, should be confirmed by a more accurate method that can distinguish between poppy seed ingestion and use of heroin or other opiates. (minddisorders.com)
  • Positive screening results should always be confirmed by a more sensitive method. (minddisorders.com)
  • If the sensitivity of the test is poor, it will give significant false-negative results. (google.com)
  • If its not due to some other reason then I'm confused by the posts where people said their Herpeselect test were negative but IgM was positive and they were told they should disregard the IgM results. (medhelp.org)
  • Diagnostic antibody tests can give false positive results because of cross reaction against related viruses such as dengue. (bmj.com)
  • Based on the results of this study the EC3 value is calculated to be 64.9% v/v. The SI for the positive control substance hexyl cinnamic aldehyde (HCA) was 6.5 which demonstrates the validity of this study. (europa.eu)
  • But culture need 6-8week with 10-20% false positive results. (wikipedia.org)
  • [15] In positive psychology , anxiety is described as the mental state that results from a difficult challenge for which the subject has insufficient coping skills. (wikipedia.org)
  • citation needed] This resulted in false-positive reactions. (wikipedia.org)
  • Brucellin preparations for the intradermal test must be free of lipopolysaccharide and must not produce non-specific inflammatory reactions or interfere with serological tests. (fao.org)
  • Regardless of their individual experiences of cancer within the family, faith in the ability of mammography to detect a cancer at an early stage gave reassurance that a cancer diagnosis could lead to a positive outcome. (biomedcentral.com)
  • Conclusions: The B. melitensis B115-based ELISA systematically unravelled all false positive (FP) sera while confirming the diagnosis in Brucella-infected animals. (researchsquare.com)
  • But late in 2004 we came to realize that some people in our program did not have HIV, so we re-tested a number of them-and identified almost 50 who were suspect for false positive HIV diagnosis. (plos.org)
  • This news was devastating, considering the consequences a false diagnosis can have on people's lives. (plos.org)
  • All patients with a suspected false diagnosis were counseled and re-tested using the confirmation test. (plos.org)
  • The new test is specific in confirming the diagnosis so when it's positive, we can be very sure it means allergy," Dr Alexandra Santos, an MRC Clinician Scientist at King's College London, said in a press release. (upi.com)
  • Biological false-positive tests comprise a high proportion of Venereal Disease Research Laboratory reactions in an analysis of 300,000 sera. (nih.gov)
  • There were 80 sera from blood donors which gave biological false-positive reactions. (bmj.com)
  • Sixty-six of the sera showed chronic biological false-positive reactions. (bmj.com)
  • RBPT positive and CFT negative, as well as double positive (DP) sera, i.e. (researchsquare.com)
  • All positive sera, i.e. from Brucella-infected animals, were RBPT positive and CFT positive (ICFTU ranging from 20 to 1280) and gave ELISA O.D. values above the cutoff. (researchsquare.com)
  • Despite its great sensitivity, the CMV IgM test is limited by a one-way cross-reaction of acute EBV infectious mononucleosis sera. (medscape.com)
  • In all tests, eight of nine sera from patients with larva currens were positive. (asm.org)
  • The prevalence of HIV-1 and HIV-2 co-infection among HIV positive sera was 16.7% (95% CI: 4.7 - 44.8). (who.int)
  • With regard to reactivity in VDRL testing, 2799 patients (0.92%) of the study population were positive, of whom 736 (26%) were biological false positive. (nih.gov)
  • This proportion might be even higher, as reactivity in the VDRL at 1:0 and 1:2 dilutions without a positive treponemal test was not reported. (nih.gov)
  • The low predictive value is a result of cross-reactivity with BCG and atypical mycobacteria, as well as false negative reactions in malnourished children. (wikipedia.org)
  • In this study, we evaluated the performance of a new fourth-generation ADVIA Centaur HIV antigen /antibody combo (CHIV) assay (Siemens Healthcare Diagnostics Inc., USA) for early detection of HIV infection and reduction of false positive rate. (curehunter.com)
  • Although Mallein is the most commonly used form of testing for glanders, cross reactions were reported between Burkholderia mallei and Streptococcus equi, which is a bacteria-caused contagious upper respiratory tract infection of equines. (wikipedia.org)
  • The performance characteristics of these tests were influenced negatively by concomitant HIV infection and the presence of other genital ulcer disease pathogens in lesions found to be Treponema pallidum PCR positive. (thefreelibrary.com)
  • This means that in groups of known-positive KHV infection, you have a one-or-two out of three chance of actually finding it. (koivet.com)
  • Therefore, a test for IgM antibody to any particular infection may be positive before a test that detects IgG antibody. (medhelp.org)
  • Bottom lines: Sometimes a new HSV infection in an adult indeed will be positive by IgM before IgG. (medhelp.org)
  • If certain other vertically transmissible infections are suspected because of a positive antenatal test result, confirmatory tests for maternal and, if indicated, fetal infection are essential before intervention is considered (eg, cytomegalovirus infection). (mja.com.au)
  • The predictive value of a positive or negative FANA test result was calculated using different pretest probabilities based on clinical criteria. (annals.org)
  • This complementary qualitative study explored the value women placed on having joined a programme of regular screening, and sought to understand the reactions of women who had received an initial all-clear result and who had received an all-clear result following further tests. (biomedcentral.com)
  • Reactivation of the virus is not uncommon, sometimes occurring with viremia and a positive IgM result in the presence of IgG antibody. (medscape.com)
  • A test result that wrongly suggests that a particular disease or condition is not present is referred to as false negative. (ebscohost.com)
  • An example of a false positive is a mammography result which suggests that a patient's has breast cancer, but subsequent. (ebscohost.com)
  • False-negative reaction refers to a test result that is negative in an individual who nonetheless has the attribute or disease being tested for. (ebscohost.com)
  • False-positive reaction refers to a test result that is positive in a person who is actually healthy. (ebscohost.com)
  • Certain foods, such as poppy seeds, may result in a positive urine screen for opiates, since poppy seeds are derived from opium poppies. (minddisorders.com)
  • The person's medical risk factors determine at which increment (5 mm, 10 mm, or 15 mm) of induration the result is considered positive. (wikipedia.org)
  • [7] A positive result indicates TB exposure. (wikipedia.org)
  • The size of the induration considered to be a positive result depends on risk factors. (wikipedia.org)
  • Interpretation of semiquantitative reagent strips, which are colorimetric tests, requires knowledge of urine color because discolored urine may result in a false-positive result. (merckvetmanual.com)
  • Could either of these medications produce a false negative or false positive result? (thebody.com)
  • The currently licensed Du Pont Western blot test specifies that the test result should be interpreted as positive only when the detected bands include p24 and p31, and gp41 or gp120/160 (12) (see Table 2). (cdc.gov)
  • Which of the following situations can result in a false-negative reaction with Rh typing reagents? (labce.com)
  • The ELISA titer indicate the positive or negative result. (wikipedia.org)
  • Benedict's or Fehling's tests soln, Clinitest ® ) may produce false-positive result. (mims.com)
  • The subgroup of HIV-positive patients (n = 1415) revealed a 10-fold higher rate of BFP tests (2.1% versus 0.24), an effect being statistically significant. (nih.gov)
  • Neither of the two tests is able to avoid the detection of false positive serological reactions (FPSRs) caused by bacteria sharing S-LPS components with Brucella spp. (researchsquare.com)
  • Positive tests were repeated. (elsevier.com)
  • A persistent problem with these tests is false-positive reactions. (medscape.com)
  • The IHA and the LF tests were more specific in that no false positive reactions occurred. (ajtmh.org)
  • The difficult topic: false positive HIV tests. (plos.org)
  • The 2 study sites initially showed a 7% false positive rate using the national algorithm, which relies on 2 out of 3 positive tests ("tie-breaker" algorithm). (plos.org)
  • A patient taking prescribed codeine pills and an individual using heroin would both show positive urine screening tests for opiates. (minddisorders.com)
  • This reaction is the basis of traditional nontreponemal tests such as the VDRL test and rapid plasma reagin test. (aafp.org)
  • First, false positive tests are common--that is, apparent IgM antibody that simply isn't present at all, despite what the test says. (medhelp.org)
  • What I noticed is that the absorbance values of the specimens that tested negative when diluted [1: 400], but positive when undiluted [1:1], had lower values than the samples that, diluted, react positive on both the ELISA and Western blot tests. (whale.to)
  • Adults with extensive pulmonary disease, frequent cough, and heavy sputum production that is acid-fast smear positive are most likely to be infectious. (healio.com)
  • Different examination have shown that rheumatoid factor is not responsible for false positive reaction [F. P. R. ] in Cr. (who.int)
  • False-positive reactions have resulted from the presence of rheumatoid factors. (medscape.com)
  • The assay is sensitive and, unlike prior sandwich assays for the antigen, is not affected significantly by cross-reactions with rheumatoid factor. (google.com)
  • Conclusions: If false positives are suspected, we recommend computed tomography (CT) of the chest and repeat RT-PCR. (elsevier.com)
  • Studies have shown that not all positive patch test reactions are reproducible upon retesting, that is, persistent. (bioportfolio.com)
  • There was no statistically significant correlation between RPR titre and total protein albumin gap, surrogate of immunoglobulin levels among patients with BFP reactions. (bmj.com)
  • KIR have either two (KIR2D) or three (KIR3D) extracellular immunoglobulin domains and either short (S) or long (L) intracytoplasmic tails which transduce positive and negative signals, respectively ( 4 - 7 ). (rupress.org)
  • A person who received a BCG vaccine (administered in some countries but not the U.S.) against tuberculosis may also have a positive skin reaction to the TB test. (medicinenet.com)
  • However, only a few recent reports described the incidence and clinical characteristics of patients with BFP reactions. (bmj.com)
  • Clinical characteristics and laboratory data of patients with BFP reactions were reviewed manually. (bmj.com)
  • Most BFP reactions were observed in patients aged over 60 years, with a history of malignancy and autoimmune diseases. (bmj.com)
  • BFP reactions were more likely to persist beyond 6 months among patients with RPR titre of ≥1:8. (bmj.com)
  • and even when truly positive, there is no distinction between HSV-1 and HSV-2, which is pretty important to most patients and providers. (medhelp.org)
  • To diagnose peanut allergy, medical personnel give legume substances to patients in incrementally larger doses, testing for a reaction. (upi.com)
  • 13 and 8 isolates were false positive by the bacteriophage-based and Pastorex LATs, respectively. (asm.org)
  • The histamine-forming capability of positive isolates was not confirmed in all reports, and some reports ( 52 , 54 ) described false-positive reactions in some media due to the formation of alkaline compounds or false-negative responses due to fermentation by some bacteria. (asm.org)
  • The challenges include robust object tracking, stationary object detection, reactions for false positives etc. (sae.org)
  • The largest number of false positives was found with methods that used tTG in association with gliadin peptides as antigen substrate. (nih.gov)
  • 7) Subsequent restimulation of these sensitized lymphocytes with the same or a similar antigen, such as the intradermal injection of TUBERSOL, evokes a local reaction mediated by these cells. (nih.gov)
  • Reduction of the HIV seroconversion window period and false positive rate by using ADVIA Centaur HIV antigen/antibody combo assay. (curehunter.com)
  • Paget cells showed a conspicuous positive reaction with antiserum to CEA, but were negative when nonspecific cross-reacting-antigen (NCA)-absorbed antiserum to CEA, or a monoclonal antibody to CEA was used as the detecting agents. (wikigenes.org)
  • For persons who are otherwise at low risk and are tested at the start of employment, a reaction of ≥15 mm induration is considered positive. (drugs.com)
  • The reaction is read by measuring the diameter of induration (palpable raised, hardened area) across the forearm (perpendicular to the long axis) in millimeters. (wikipedia.org)
  • The positive control group received 25% v/v hexylcinnamic aldehyde in AOO based on previous experience at this laboratory. (europa.eu)
  • Patch-test readings after day 5 have previously been used to identify delayed reactions to metals and topical antibiotics. (bioportfolio.com)
  • To evaluate the safety of Disperse blue 106 and Bronopol T.R.U.E. Test allergens in 20 adult subjects per allergen with a clinical history of contact dermatitis and a positive patch test to the respective reference allergen. (bioportfolio.com)
  • The test is positive within one day of onset of symptoms and persists for days to weeks, and in one case persisted over 300 days ( JCM 1984;20:605). (lww.com)
  • Histamine accumulation occurred when PCR amplification of hdc was positive in all of fish samples tested and the presence of powerful histamine producers was confirmed by subsequent SSCP identification. (asm.org)
  • We calculated the incidence of BFP reactions. (bmj.com)
  • Conclusion There was a low incidence of BFP reactions in the last decade. (bmj.com)