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At least 649 records · Page 36Linked to original sources

PubMed2004

Computer-aided detection output on 172 subtle findings on normal mammograms previously obtained in women with breast cancer detected at follow-up screening mammography.

PURPOSE: To evaluate, by using a computer-aided detection (CAD) program, the nonspecific findings on normal screening mammograms obtained in women in whom breast cancer was later detected at follow-up screening mammography. MATERIALS AND METHODS: Four hundred ninety-three mammogram pairs-an initial negative screening mammogram and a subsequently obtained screening mammogram showing cancer-were collected. The mean interval between examinations was 14.6 months. In 169 cases, in which 172 cancers were later depicted, findings on the initial mammogram were subtle enough that either none or only one or two of five blinded radiologists recommended screening recall. On the initial negative mammograms, of the 172 areas where cancer later developed, 137 (80%) had subtle nonspecific findings and were retrospectively judged as having a benign or normal appearance. The mammograms with these subtle findings were evaluated with a commercially available CAD program, and the numbers of CAD marks on these nonspecific findings were analyzed. RESULTS: Of the 172 cancers, 129 (75%) were invasive and 43 (25%) were ductal carcinoma in situ. The CAD program marked 72 (42%) of the 172 findings that subsequently developed into cancer: 24 (29%) of 82 findings recalled by none, 25 (49%) of 51 findings recalled by one, and 23 (59%) of 39 findings recalled by two of the five radiologists. Among the 137 areas with nonspecific normal or benign findings, 41 (30%) areas where cancer subsequently developed were marked by the CAD program. CONCLUSION: A subset of cancers have perceptible but nonspecific mammographic findings that may be marked by a CAD program, even when the findings do not warrant recall as judged at blinded and unblinded radiologist review. The authors believe failure to act on such nonspecific but CAD-marked findings prospectively does not constitute interpretation below a reasonable standard of care.

Adult↗

PubMed1992

Plain and computed radiography for detecting experimentally induced pneumothorax in cadavers: implications for detection in patients.

Pneumothorax was induced in cadavers to determine the effects of patient positioning and imaging modality (conventional screen-film and computed radiography) on radiographic findings. Chest radiography, with cadavers in the supine frontal, erect frontal, and left lateral decubitus positions, was performed at baseline and after injection of incremental quantities of air into the pleural space. Five radiologists independently interpreted each radiograph. The ability of the radiologists to diagnose pneumothorax varied by cadaver position and depended on volume of air. Overall, the left lateral decubitus view was most sensitive (88%) for diagnosis of pneumothorax, followed by the erect (59%) and supine (37%) views. Receiver operating characteristic curves and multiple repeated measures analysis of variance revealed no statistically significant difference between diagnostic proficiency with conventional screen-film radiography and that with computed radiography. The authors conclude that the lateral decubitus view is superior to the erect and supine views for pneumothorax detection and that conventional and computed radiography perform similarly in pneumothorax detection.

Cadaver↗

PubMed2004

N-acetyl functions and acetate detected by nuclear magnetic resonance spectroscopy of urine to detect renal dysfunction following aminoglycoside and/or glycopeptide antibiotic therapy.

BACKGROUND/AIMS: N-acetylneuraminidine (NeuNAc), N-acetylglutamine (GIcNAc) and acetate are metabolites present in normal urine. In patients treated with aminoglycosides and/or glycopeptides, elevation of these metabolites in urine suggests renal tubular injury. NeuNAc, GIcNAc and acetate are easily detected by magnetic resonance spectroscopy (MRS), in contrast to other bioanalytical methods. In the present study, these urinary metabolites were detected using MRS and compared with standard biochemical markers of renal injury in intensive care unit patients treated with aminoglycosides and/or glycopeptides. METHODS: 16 patients with clinical and biochemical signs of renal dysfunction were included in the study. Proton magnetic resonance spectra were obtained from 134 urine samples. The resonance intensity of NeuNAc, GIcNAc and acetate were reported relative to the resonance intensity of creatinine (ct). These ratios were compared with classical parameters of renal dysfunction, such as plasma creatinine and urea concentration, and 24-hour urine volume, by logistic regression and general linear models. RESULTS: Statistical analysis showed that changes in plasma creatinine and urea concentration were reliably reflected in changes in the NeuNAc/ct ratio, and that plasma urea concentration changes also correlated with the acetate/ct ratio; however, the GIcNAc/ct ratio was not related to these measures of overall renal function. CONCLUSIONS: NeuNAc/ct may be a useful marker of renal dysfunction in patients treated with aminoglycosides and glycopeptides; by MRS it can be both straightforward and informative to follow the renal function of patients treated with these antibiotics.

Acetates↗

PubMedDate not supplied

Immunocytochemical detection of HPV high-risk type L1 capsid proteins in LSIL and HSIL as compared with detection of HPV L1 DNA.

OBJECTIVE: To investigate the prevalence of HPV L1 capsid proteins in HPV-infected HSIL and LSIL. STUDY DESIGN: Cervical smears from 74 women with cytologically and histologically confirmed LSIL (n = 32) and HSIL (n = 42) were collected prospectively to detect HPV high-risk (hr) types 16, 18, 33, 35, 39, 45, 56 and 58 L1-DNA by standardized L1-consensus primer PCR (MY 09/11) and L1 capsid proteins by immunocytochemistry using monoclonal antibodies T31 (HPV16) and T16 (HPV hr) in a standardized protocol. RESULTS: In HSIL and LSIL, L1 DNA was found for HPV hr in 93% and 59% and for HPV16 in 69% and 37% of the specimens, respectively. HPV L1 capsid proteins were detected in HSIL and LSIL for HPV hr in 33% and 44% and for HPV16 in 29% and 31% of the specimens, respectively. Expression of L1 capsid proteins was significantly reduced, by 59.6% for HPV hr L1 DNA-positive HSIL (P < .01) and by 40.4% for HPV 16 L1 DNA-positive HSIL (P < .01). In HPV 16 DNA-positive and HPV hr DNA-positive LSIL, no significant reduction of corresponding L1 capsid protein expression could be demonstrated. CONCLUSION: These data suggest a disturbed viral cellular interaction in HPV 16 and HPV hr-infected HSIL, with loss of viral L1 capsid antigen. In this context there is a possible role of T31 and T16 as prognostic markers to predict the prognosis of CIN.

Adolescent↗

PubMed1997

Detection of phosphatidylinositol glycan class A gene transcripts by RT in situ PCR hybridization. A comparative study using fluorescein, Texas Red, and digoxigenin-11 dUTP for color detection.

Gene-specific probes labeled with fluorescein, Texas Red, and digoxigenin-11 dUTP (DIG) were used for RT in situ PCR hybridization to detect PIG-A gene (phosphatidylinositol glycan class A) transcripts. The PIG-A gene is responsible for biosynthesis of the glycosylphosphatidyl-inositol (GPI) anchor. Lack of GPI anchor expression due to mutations can cause an acquired clonal hematologic disorder called paroxysmal nocturnal hemoglobinuria (PNH). In this RT in situ PCR study, two types of labeling methods, a direct method (using fluorescein and Texas Red) and an indirect method (using DIG-11 dUTP) were compared. Both were successfully applied to detect and localize the PIG-A gene transcripts within single cells of the cell lines AA2, H9, and JY. Furthermore, similar results for sensitivity and reproducibility were obtained. Advantages and disadvantages of the different labeling techniques are discussed. In addition, peripheral blood mononuclear cells from PNH patients were also included in this study.

Cells, Cultured↗

PubMed1991

Potential and limitations of angle-independent flow detection algorithms using radio-frequency and detected echo signals.

New techniques to estimate local blood and tissue velocities have been developed by several groups, including our own. The performance of these techniques is ultimately limited by the characteristics of ultrasonic imaging systems that determine the second-order statistics of speckle. These statistical parameters vary widely depending on the dimension of analysis in the image plane (lateral or axial) and on the echo input signal (radio-frequency or detected data). We use experiments and theory to examine these factors and describe their impact on the performance of our correlation-based technique for angle-independent tracking of blood or tissue motion. The results indicate that the second-order statistics determine the performance of our correlation-based algorithm and can be used to predict the performance of other angle-independent flow detection techniques.

Algorithms↗

PubMed2003

Human infection with Wuchereria bancrofti in Matara, Sri Lanka: the use, in parallel, of an ELISA to detect filaria-specific IgG4 in urine and of ICT card tests to detect filarial antigen in whole blood.

The ICT card test to detect circulating filarial antigen and an ELISA that detects filaria-specific urinary IgG(4) were each used to screen 473 subjects from a community in Sri Lanka where Wuchereria bancrofti is endemic. When the ICT test was used as the gold standard, the ELISA was found to have a sensitivity of 91.2%. However, far more of the subjects were found ELISA-positive than ICT-positive (76.5% v. 31.1%). The youngest children studied (aged 1-10 years) were similar to the adult subjects in terms of the prevalence of antigenaemia (33.8%) and the prevalence (72.1%) and concentration of filaria-specific IgG(4) in their urine. Therefore, especially as urine samples are easier, less painful and safer to collect than blood samples, the ELISA may be particularly useful to screen very young and school-age children, to estimate current levels of transmission in a particular area.

Adolescent↗

PubMed2005

Design of the BiRmingham Early Detection In untREated psyChosis Trial (REDIRECT): cluster randomised controlled trial of general practitioner education in detection of first episode psychosis [ISRCTN87898421].

BACKGROUND: Treatment delay in first episode psychosis is common. As general practitioners are the first point of contact for many individuals with first episode psychosis, they are well placed to detect the early symptoms and make urgent referrals to specialist secondary care services. However, early psychosis is often difficult to detect. The primary objective of the Redirect trial is to estimate whether an educational intervention targeted at general practitioners increases the general practitioner referral rate of young people with first episode psychosis to Early Intervention Services. METHODS/DESIGN: This paper describes the design of a stratified-cluster randomised controlled trial of an educational intervention on first episode psychosis in primary care. The primary outcome is the number of general practitioner referrals of young people with first episode psychosis to Early Intervention Services. Secondary outcomes are duration of untreated psychosis, time to recovery, use of the Mental Health Act, and general practitioner consultation rate. Young people with first episode psychosis referred to Early Intervention Services will be recruited over a two-year period from 1 March 2004. Seventy-eight out of 89 eligible general practices were recruited. The educational intervention has been implemented and evaluated by general practitioners. The education was well received and considered relevant to clinical practice by the general practitioners. DISCUSSION: The results suggest that the recruitment strategy and implementation of the educational intervention are feasible and acceptable in a primary care setting. The Redirect trial will provide robust information about the efficacy of an evidence-based complex educational intervention targeted at general practitioners on referral rates of young people with first episode psychosis to Early Intervention Services.

Adolescent↗

PubMed2006

Detection of aberrant methylation of four genes in plasma DNA for the detection of breast cancer.

PURPOSE: Novel approaches to breast cancer screening are necessary, especially in the developing world where mammography is not feasible. In this study, we explored the hypothesis that blood-based biomarkers have potential for biomarkers for breast cancer. PATIENTS AND METHODS: We first determined the frequency of aberrant methylation of four candidate genes (APC, GSTP1, Rassf1A, and RARbeta2) in primary breast cancer tissues from West African women with predominantly advanced cancers. We used a high-throughput DNA methylation assay (quantitative methylation-specific polymerase chain reaction) to examine plasma from 93 women with breast cancer and 76 controls for the presence of four methylated genes. Samples were randomly divided evenly into training and validation data sets. Cutoff values for gene positivity of the plasma-based assay and the gene panel were determined by receiver operating characteristic curves in the training data set and subsequently evaluated as a screening tool in the validation data set. RESULTS: Methylation of at least one gene resulted in a sensitivity of 62% and a specificity of 87%. Moreover, the assay successfully detected 33% (eight of 24) of early-stage tumors. CONCLUSION: These data suggest that epigenetic markers in plasma may be of interest for detection of breast cancer. Identification of additional breast cancer specific methylated genes with higher prevalence in early stage cancers would improve this approach.

Adult↗

PubMed2006

Chemical fingerprinting of Shexiang Baoxin Pill and simultaneous determination of its major constituents by HPLC with evaporative light scattering detection and electrospray mass spectrometric detection.

High-performance Liquid Chromatography (HPLC) with evaporative light scattered detection (ELSD) and electrospray ionization mass spectrometric detection (ESI-MS) was employed to establish chemical fingerprint of Shexiang Baoxin Pill (SBP) and to simultaneously determinate its seven major constituents, including cholic acid, deoxycholic acid, ursodeoxycholic acid, chenodeoxycholic acid, cinobufagin, recibufogenin, and ginsenoside Rb1. The analysis was performed on a C18 column with water-acetonitrile gradient elution, and the investigated constituents were authenticated by comparing their retention times and mass spectra with those of reference compounds. The proposed method was applied to analyze nine SBP samples and produced data with acceptable linearity, precision, stability and accuracy. Both the chemical fingerprints and quantification data were used to evaluate the quality of various SBP products. The proposed method allows obtaining chemical fingerprint and quantification of multi-components in one run, and therefore can be readily utilized as a comprehensive quality control approach for traditional Chinese medicine.

Chromatography, High Pressure Liquid↗

PubMed2005

Trace detection of explosives with low vapor emissions by laser surface photofragmentation-fragment detection spectroscopy with an improved ionization probe.

Trace explosive residues are measured in real time by surface laser photofragmentation-fragment detection (SPF-FD) spectroscopy at ambient conditions. A 248-nm laser photofragments the target residue on a substrate, and a 226-nm laser ionizes the resulting NO fragment by resonance-enhanced multiphoton ionization by means of its A-X (0, 0) transitions near 226 nm. We tested two probes on selected explosives and modeled their electric field in the presence of a substrate with an ion optics simulation program. The limits of detection range from 1 to 15 ng/cm2 (signal-to-noise ratio of 3) at 1 atm and 298 K and depend on the electrode orientation and mechanism for NO formation.

Journal Article↗

PubMed1985

Development of enzyme-linked immunospecific assay (ELISA) for the detection of monoclonal antibody: application to detection of monoclonal anti-TBG.

An enzyme-linked immunospecific assay (ELISA) was developed to screen monoclonal antibody to human thyroxine-binding globulin (TBG). The assay is based on the absorption of TBG from human pooled serum by rabbit polyclonal anti-TBG antibody coated on a microtiter plate and subsequent binding of monoclonal antibody to the absorbed antigen. Monoclonal antibody which binds TBG can be detected by peroxidase labeled anti-mouse IgG. From the examination with two different rabbit polyclonal anti-TBG antibodies, it was demonstrated that both purified IgG fraction and whole serum could be used as coating materials. It was not necessary to use purified TBG to react with anti-TBG antibody coated on the microtiter plate. When eight commercially available microtiter ELISA plates were tested in the assay, only 3 gave satisfactory results. The sensitivity of the assay was comparable with that of the conventional immunoprecipitation method using 125I-TBG and formalin fixed Staphylococcus aureus (Kowan strain) as an immunoabsorbent. The ELISA method could detect antibody activity in 0.032 microliter of medium obtained from a 3 day culture of confluent hybridoma cells. It is possible to store the antibody-antigen complexed microtiter plate for more than 2 weeks at 4 C. This makes possible rapid screening of monoclonal antibody.

Animals↗

PubMed2006

Increased sensitivity in detecting renal impairments by quantitative measurement of marker protein excretion compared to detection of pathological particles in urine sediment analysis.

BACKGROUND: Positive test strip results, pathological particles in urine and the presence of proteinuria are common findings in nephropathies. A comparison between these methods and renal biopsies became available with the introduction of quantitative measurement of marker proteins (albumin, transferrin, IgG, alpha(1)-microglobulin, retinol binding protein, alpha(2)-macroglobulin, Bence Jones proteins) and standardised urine sediment analysis by flow cytometry or microscopy. METHODS: A total of 400 urine samples were examined using marker protein patterns, test strips and quantitative sediment analyses. RESULTS: Results from standardised urine sediment analyses were compared with the excretion of renal marker proteins. Increased erythrocyte and leukocyte counts in urine were observed in only 29% and 39% of the samples for which pathological protein excretion was found. The sensitivity in detecting pathological particles in urine sediment, such as casts and/or dysmorphic erythrocytes, was only 19%. Renal biopsies from 65 patients who were classified as pathological were compared with proteinuria and sediment analyses. Increased excretion of marker proteins was found in all cases, whereas only 41% of the cellular urine sediments showed pathological results. CONCLUSIONS: Quantitative measurement of marker proteins from both the glomerular and tubular sides should be used upfront as screening parameters for the early detection of renal disorders.

Alpha-Globulins↗

PubMed1987

A rapid method for the detection of papillomavirus in warts: the frequency of virus detection in various types of warts.

A rapid method was devised for the detection of virus particles in wart specimens. The upper layer of warts was cut perpendicularly to the surface, and the freshly cut surface was lightly touched to an electron microscope grid. The grid was then stained with a small drop of phosphotungstate and observed electron microscopically. On the specimen grid thus prepared, papillomavirus particles were easily discriminated from tissue debris. Papillomavirus particles were detected in 71% of verrucae plantares, 78% of verrucae palmares, 50% of verrucae vulgares and 75% of condylomata acuminata by the present method.

Condylomata Acuminata↗

PubMed2005

Single-molecule detection and probe strategies for rapid and ultrasensitive genomic detection.

This paper reviews the current state-of-the-art development of single-molecule detection (SMD)-based methods for ultrasensitive and specific analysis of genomic sequences. We first discuss several newly devised single fluorescent probe strategies that allow separation-free detection of low-abundance DNA sequences, such as quantum dot (QD)-mediated fluorescence resonance energy transfer (FRET) technology and dual-color fluorescence coincidence and colocalization analysis. Various schemes toward single DNA sizing and sequencing in solutions or on surfaces are also reviewed. In the end, we summarize the different microfluidic approaches developed for use with SMD to facilitate rapid, low-volume and quantitative analysis, such as electrokinetic and hydrodynamic single-molecule manipulation techniques.

DNA Probes↗

PubMed2004

Comparison of three PCR methods for detection of Helicobacter pylori DNA and detection of cagA gene in gastric biopsy specimens.

AIM: To comparatively evaluate PCR and other diagnostic methods (the rapid urease test and / or culture) in order to determine which of the three PCR methods (ureA, glmM and 26-kDa, SSA gene) was most appropriate in the diagnosis of Helicobacter pylori (H pylori ) infection and also to evaluate the detection of a putative virulence marker of H pylori, the cagA gene, by PCR in biopsy specimens. METHODS: One hundred and eighty-nine biopsy specimens were collected from 63 patients (three biopsies each) undergoing upper gastroduodenal endoscopy for various dyspeptic symptoms. The PCR methods used to detect H pylori DNA directly from biopsies were the glmM, 26-kDa, ureA and then cagA was used to compare the culture technique and CLO for urease with the culture technique being used as the gold standard. RESULTS: Thirty-five percent of the biopsies were positive for H pylori DNA using the 3 PCR methods, while 68% of these were positive for the cagA gene. Twenty-four percent of the biopsies were negative for H pylori DNA in all PCR methods screened. The remaining 41% were either positive for ureA gene only, glmM only, 26-kDa only, or ureA + glmM, ureA + 26-kDa, glmM + 26-kDa. Out of the 35% positive biopsies, 41% and 82% were positive by culture and CLO respectively, while all negative biopsies were also negative by culture and cagA. Cag A+ infection was also predominantly found in H pylori DNA of the biopsies irrespective of the clinical diagnosis. CONCLUSION: This method is useful for correctly identifying infections caused by H pylori and can be easily applied in our laboratory for diagnostic purposes.

Antigens, Bacterial↗

PubMed1997

A signal detection theory analysis of gap detection in the rat.

An innocuous sensory event (a prestimulus) briefly preceding a startle-eliciting stimulus (SES) reduces the amplitude of the elicited reflex. This study used signal detection theory (SDT) techniques to quantify the effects of gaps (pauses in otherwise continuous noise) on the rat's acoustic startle reflex. Sixteen rats were given four identical test sessions consisting of the randomized presentation of 150 trials of the SES alone and 150 trials of a gap-and-SES combination. Gap duration (1, 2, 4, and 8 msec) varied between sessions. Data analyses based on amplitude, difference scores, percentage scores, and SDT techniques identified similar patterns. The three longest gaps, but not the shortest, were reliably detected, and differences among these three were identified with percentage and SDT analyses. Analyses of amplitude changes over test sessions yielded different patterns for each measure. The results demonstrate that an SDT analysis is a sensitive index of prestimulus effects.

Animals↗

PubMed1985

[SOL-detectability of liver SPECT--analysis by SOL detection model].

The purpose of this study is to evaluate the clinical efficacy of liver SPECT (single photon emission computed tomography). Eleven hospitals which are in or near Tokyo are participating in this study. Planar liver images and SPECT images of 134 cases which were retrospectively confirmed for its final diagnosis were collected. At the first study, the planar images (PS) were read by 13 nuclear medicine physicians. The second, the image reading by the combination of the planar images and the SPECT images (PS + SPECT) were performed. The confidence level of diagnosis for SOL (space occupying lesion) obtained by the image reading of PS and PS + SPECT has been analyzed by using the SOL detection model. The SOL detectability of PS + SPECT was higher than that of PS only. However, these differences were not statistically significant.

Diagnosis, Differential↗