SEARCH · Search PubMed

Results for “object detection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources

PubMed1996

Visual awareness of objects correlates with activity of right occipital cortex.

In the search for human neural correlates of visual awareness, cortical magnetic responses to coherent and meaningful objects were compared with responses to disorganized and meaningless non-objects when observers tried to detect the coherent objects. Three brief stimulus durations were included to vary the detection rate of the objects. Of the multiple brain regions activated, only the right lateral occipital cortex showed signals correlating with the proportion of correct object detections. The results suggest an important role for this area in visual awareness of objects.

Adult↗

PubMed2002

Determination of the minimal clinically important difference in rheumatoid arthritis joint damage of the Sharp/van der Heijde and Larsen/Scott scoring methods by clinical experts and comparison with the smallest detectable difference.

OBJECTIVE: To assess the minimal clinically important difference (MCID) in joint damage on hand and foot radiographs of patients with early rheumatoid arthritis (RA) as assessed with the Sharp/van der Heijde and Larsen/Scott methods, and to study how the smallest detectable difference (SDD) relates to the MCID for each method. METHODS: The judgments of an international panel of experts on the clinical relevance of progression of joint damage as seen on sets of radiographs obtained at 1-year intervals in 4 clinical settings (early versus late RA and mild versus high disease activity) were used as the external criterion, which was compared with the progression scores as determined by the 2 scoring methods. Progression scores with the highest combined sensitivity and specificity for detecting clinically relevant progression represented the MCID. Subsequently, the sensitivity and specificity of the scoring methods were determined when using the SDD as the threshold for relevant progression, and these were compared with the sensitivity and specificity of the MCID. RESULTS: The panel judged changes in joint damage around the level of the SDD (5.0) of the Sharp/van der Heijde method as minimal clinically important, resulting in satisfactory sensitivity (mean 79%) and specificity (mean 84%) for detecting clinically important progression in the 4 clinical settings when using the SDD as the threshold value. The MCID (mean 2.3) of the Larsen/Scott method was much smaller than its SDD (5.8), and the sensitivity for detecting clinically important progression by applying the SDD as threshold was consequently low (mean 51%), accompanied by high specificity (mean 99%). CONCLUSION: This study suggests that the SDD of the Sharp/van der Heijde method can be used as the MCID, i.e., as the threshold level for individual response criteria. The SDD of the Larsen/Scott method, however, turned out to be too insensitive to use as the threshold for individual clinically relevant change.

Arthritis, Rheumatoid↗

PubMed2006

Comparing performance of Morbidity and Mortality Conference and National Surgical Quality Improvement Program for detection of complications after urologic surgery.

OBJECTIVES: The detection of postoperative complications is a necessary quality-of-care endeavor. Despite its historical role, the Morbidity and Mortality (M&M) Conference depends on voluntary reporting and may be an insufficient mechanism for comprehensive complication surveillance. In response to this concern, we compared the concordance between complications voluntarily reported at the M&M Conference and those identified prospectively by the National Surgical Quality Improvement Program (NSQIP). METHODS: For a single calendar year (2004), we compiled a comprehensive list of complications that were either identified and voluntarily entered into our department's electronic M&M Conference database and/or identified prospectively (from an explicit sample of cases) by a trained research associate-based NSQIP protocol. For analytic purposes, we treated NSQIP as the reference standard for the detection of complications. We then determined the sensitivity of the M&M Conference for the identification of complications at a patient and event level. Logistic regression modeling was used to evaluate for an association between complication category (ie, organ system affected) and detection by the M&M Conference. RESULTS: The NSQIP detected 347 complications in 176 patients. Using this reference standard, the patient-level and event-level sensitivity of the M&M Conference was 25% (44 of 176) and 14% (47 of 347), respectively. The sensitivity of the M&M Conference varied by NSQIP complication category (P = 0.08). Circulatory events were 11 times more likely to be reported at the M&M Conference than urinary complications (odds ratio 11.3, 95% confidence interval 2.4 to 53.7). CONCLUSIONS: Compared with the NSQIP, the M&M Conference has a low (but variable) sensitivity for the detection of postoperative complications. Therefore, despite its limitations, the NSQIP may provide a better foundation for urologic quality improvement endeavors.

Adolescent↗

PubMed2005

Using proteomic approaches to identify new biomarkers for detection and monitoring of ovarian cancer.

OBJECTIVES: Early detection and monitoring the treatment remain the most important factors in improving long-term survival of ovarian cancer patients. New biomarkers that individually or in combination improve the diagnostic performance of existing tumor markers are critically needed. This study uses proteomic approaches to identify new biomarkers for detection and monitoring of ovarian cancer. METHODS: We analyzed protein profiles of three sets of sera using surface enhanced laser desorption and ionization time-of-light mass spectroscopy (SELDI-TOF-MS) on IMAC ProteinChip arrays and ProPeak software for bioinformatics data analysis. The first set of patients included 21 ovarian cancers, 18 benign diseases, and 20 normal patients. The second set included 32 ovarian cancers, 30 benign ovarian diseases, and 30 age-matched healthy controls. The third set included samples collected before and after chemotherapy from 18 ovarian cancer patients. All samples were collected at the Gynecology and Obstetrics Hospital of Fudan University in Shanghai, China. The datasets from low-intensity and high-intensity spectra were analyzed separately. RESULTS: Seven peaks were selected for their contribution to the separation of ovarian cancers from controls using the first and second set of samples. The same dysregulation trends were confirmed for six of the seven peaks in independent validation using the third set of samples. CONCLUSIONS: Using SELDI-TOF analysis of 195 unique specimens, we discovered with preliminary validation six distinct peaks that may potentially be useful in the detection and monitoring of ovarian cancer. Additional studies are required to determine the protein identities of these peaks and to further validate their performance as biomarkers.

Adult↗

PubMed2006

[Infrared spectroscopy technology, one of the faster and more convenient methods to detect the stability of stored Niuxi].

OBJECTIVE: To detect the change of Niuxi in reserve and establish one easier method of evaluating the quality change of Niuxi. METHODS: Infrared spectroscopy and compare software were used to distinguish the different Niuxi, and simulation testing were used to observe calefactive stability. RESULTS: There were obvious difference between transmutative and normal Niuxi, and Niuxi had evident change when the temperature above 140 degrees C in the simulation testing. CONCLUSION: Infrared spectroscopy can be used to evaluae the quality stability of Niuxi. It is one tried method to provide the establishment of reserve and torrefaction conditions.

Achyranthes↗

PubMed1999

Preconceptional screening of couples for carriers of cystic fibrosis: a prospective evaluation of effects, costs and savings for different mutation detection methods.

OBJECTIVE: The aim of this study was to perform a prospective evaluation of the effects, costs and savings of a preconceptional screening programme of couples for carriers of cystic fibrosis (CF). METHODS: A decision model for both single-entry two-step (SETS) and double-entry two-step (DETS) couple screening was constructed. Two mutation detection methods were considered: allele-specific oligonucleotide (ASO) hybridisation screening of 32 mutations, with a sensitivity of 90%, and denaturing gradient gel electrophoresis (DGGE), with a sensitivity of 98%. In our model, the following combinations were used: (1) ASO for both steps; (2) DGGE for both steps, and (3) ASO for the first step and DGGE for the second step. The model is demonstrated using figures from the Netherlands, where there is a carrier frequency of 1:30. We estimated the value of different choices and probabilities in a decision tree and determined the costs of screening for CF and the costs of the illness itself. RESULTS: We found that with most of the combinations of mutation detection methods, SETS couple screening could offer positive net savings in the Netherlands. The ASO/DGGE combination resulted in the highest net savings. DETS couple screening for all combinations, including testing with DGGE in both steps, did not show a positive cost-savings balance at all, not even with an uptake rate of 100%. The maximum number of carrier couples identified when screening 100,000 couples with the ASO/DGGE combination was 98 (SETS). This could result in about 25 fewer children born with CF each year in the Netherlands, under the following assumptions: (1) each couple has two children and 10% of couples are unable to have children; (2) of detected carrier couples, 15% decide not to have children and 85% make use of prenatal diagnosis; (3) of those fetuses diagnosed with CF, 80% are aborted, and (4) prenatal diagnosis carries a 0.75% risk of iatrogenic abortion. CONCLUSIONS: The results of this evaluation show that there are no financial objections to the preconceptional screening of couples in the Netherlands when the above-mentioned assumptions apply; thus, further evaluation can concentrate on the balance of the non-economic consequences of screening for participants and for society.

Journal Article↗

PubMed2004

Syndromic surveillance: the effects of syndrome grouping on model accuracy and outbreak detection.

STUDY OBJECTIVE: Data used by syndromic surveillance systems must be grouped into syndromes or prodromes. Previous studies have examined the accuracy of different methods of syndromic grouping. We seek to study the effects of different syndrome grouping methods on model accuracy, a key factor in the outbreak-detection performance of syndromic surveillance systems. METHODS: Daily emergency department visit rates were analyzed from 2 urban academic tertiary care hospitals for 1,680 consecutive days. During this period, each hospital census totaled approximately 230,000 patient visits. Three methods were used to group the visits into a respiratory-related syndrome category: 1 relying on chief complaint, 1 on diagnostic codes, and 1 on a combination of the two. The different groupings of the syndromic data resulting from these methods were used to build different historical models that were then tested for forecasting accuracy and for sensitivity to detecting simulated outbreaks. RESULTS: For both hospitals, the data grouped according to chief complaints alone yielded the lowest model accuracy and the lowest detection sensitivity. Using diagnostic codes to group the data yielded better results in accuracy and sensitivity. Combining the 2 grouping methods yielded the best results in accuracy and sensitivity. Temporal smoothing of the data was shown to improve sensitivity in all cases, although to various degrees in the different models. CONCLUSION: The methods used to group input data into syndromic categories can have substantial effects on the overall performance of syndromic surveillance systems. The results suggest that incorporating diagnostic data into these systems can improve the modeling accuracy and its detection sensitivity. Furthermore, the best results may be achieved by using a combination of methods to group visits into syndromic categories.

Bioterrorism↗

PubMed2006

Comparison of MRI sequences to detect ventriculitis.

OBJECTIVE: The ability of different MRI sequences to depict characteristic findings suggestive of ventriculitis was compared. CONCLUSION: The study comprised 20 brain MRI studies in 13 patients who had a final diagnosis of ventriculitis. Both diffusion-weighted imaging and FLAIR imaging were equally and highly sensitive for detecting intraventricular debris and pus--the most common MRI finding suggestive of ventriculitis. FLAIR imaging was superior to contrast-enhanced T1-weighted imaging for depicting ventricular wall abnormalities--a less common finding that also is suggestive of ventriculitis.

Adolescent↗

PubMed2002

Screening for chromosomal anomalies in the first trimester: does repeat maternal serum screening improve detection rates?

OBJECTIVE: To assess the within person biological variability of first trimester maternal serum biochemical markers of trisomy 21 across the 10-14 week gestational period. To evaluate whether repeat sampling and testing of free beta-hCG and PAPP-A during this period would result in an improved detection rate. METHODS: Women presenting at the first trimester OSCAR clinic have blood collected prior to ultrasound dating and nuchal translucency measurement. All samples are analysed for free beta-hCG and PAPP-A before an accurate estimate of gestation is available. In 10% of cases the gestation is prior to the minimum time for NT measurement (11 weeks) and these women are rebooked for a repeat visit to the clinic at the appropriate time. Our fetal database was interrogated to obtain cases in which two maternal blood samples had been collected and analysed in the 10-14 week period. Using data from the marker correlations and statistical modelling, the impact of repeat testing on detection rate for trisomy 21 at a fixed 5% false positive rate, was assessed. RESULTS: 261 pairs of data were available for analysis collected over a 3 year period. The correlation between free beta-hCG in sample 1 and sample 2 was 0.890 and that for PAPP-A was 0.827. The average within person biological variation for free beta-hCG was 21% and 32% for PAPP-A. The increase in detection rate when using both sets of marker data was 3.5% when using serum biochemistry and maternal age, and 1.3% when using nuchal translucency, serum biochemistry and maternal age. CONCLUSION: Repeat sampling and testing of maternal serum biochemical markers is unlikely to substantially improve first trimester screening performance.

Chorionic Gonadotropin, beta Subunit, Human↗

PubMed2005

Ten years of breast screening in the Nova Scotia Breast Screening Program, 1991-2001. experience: use of an adaptable stereotactic device in the diagnosis of screening-detected abnormalities.

OBJECTIVE: To evaluate and present 10-year outcomes of the Nova Scotia Breast Screening Program (NSBSP), a population-based screening program in the province of Nova Scotia, Canada, total population 900 000. SETTING: Organized Breast Screening Program in Nova Scotia, Canada. METHODS: Rates of participation, abnormal referrals, cancer detection rates, and benign:malignant (B:M) rates for core biopsy and surgical biopsy were calculated for asymptomatic women receiving a mammogram through the NSBSP 1991-2001. RESULTS: Of 192 454 mammograms performed on 71 317 women, 33% were aged 40 to 49 years, 39% aged 50 to 59 years, 23% aged 60 to 69 years, and 5% aged 70 years and over. Cancer detection rate increased in each age group respectively: 3.7, 5.8, 9.7, and 13.5 per 1000 population on first-time screens. The positive predictive value of an abnormal screen increased with increasing age groups. Benign breast surgery decreased with increased use of needle core breast biopsy (NCBB). Open surgery decreased from 25 to 6 surgeries per 1000 screens. Of 1519 open surgical procedures (1328 women), 878 cancers were removed, with 37% 10 mm or less, and 61% 15 mm or less. In 613 women in whom the node status was assessed, 79% were negative. CONCLUSION: A quality screening program incorporating NCBB in the diagnostic work-up is effective in the early detection of breast cancer and results in less open surgery, particularly in younger women.

Adult↗

PubMed1999

Sensitive method for the determination of the antiarrhythmic drug detajmium in serum by solid-phase extraction and high-performance liquid chromatography with fluorimetric detection.

The objective of this study was to develop a very sensitive and selective method for the determination of detajmium (4-3-diethylamino-2-hydroxypropyl-ajmaline), a sodium-channel-blocking drug with antiarrhythmic properties, in serum. A high-performance liquid chromatography (HPLC) method with solid-phase extraction and fluorimetric detection has been applied. Serum samples were diluted with phosphate buffer (pH 3.5) and the extraction of detajmium and ajmaline, which was used as an internal standard, was carried out with Oasis cartridges (Waters). The chromatographic separation was performed on a RP18 column. The limit of quantification for serum samples of detajmium was 1 ng/ml with good reproducibility (R.S.D. < 15%) and a linear response from 1 to 200 ng/ml. The described method is highly sensitive and specific for the determination of detajmium in serum of patients and volunteers.

Ajmaline↗

PubMed2005

Influence of handling-relevant factors on the behaviour of a novel calculus-detection device.

OBJECTIVES: The aim of periodontal therapy is always the complete debridement of root surfaces with the removal of calculus and without damaging cementum. We have recently demonstrated the feasibility of a surface recognition device that discriminates dental surfaces by mathematical analysis of reflected ultrasound waves. This principle should enable the construction of calculus detecting ultrasonic device. Pre-clinical test results are presented here. MATERIAL AND METHODS: An impulse generator, coupled to a conventional piezo-driven ultrasonic scaler, sends signals to the cementum via the tip of an ultrasound device. The oscillation signal reflected from the surface contains the information necessary to analyse its characteristics. In order to discriminate different surfaces, learning sets were generated from 70 extracted teeth using standardized tip angle/lateral force combinations. The complete device was then used to classify root surfaces unknown to the system. RESULTS: About 80% of enamel and cementum was correctly identified in vivo (sensitivity: 75%, specificity: 82%). The surface discrimination method was not influenced by the application conditions examined. A new set of 200 tests on 10 teeth was correctly recognized in 82% of the cases (sensitivity: 87%, specificity: 76%). CONCLUSIONS: It was shown in vitro that the tooth surface recognition system is able to function correctly, independent of the lateral forces and the tip angle of the instrument.

Dental Calculus↗

PubMed2004

Patient perceptions of breast biopsy procedures for screen-detected lesions.

OBJECTIVE: This study was undertaken to compare patient perceptions of 2 common image-guided breast biopsy procedures on 3 main outcomes: decision making about which procedure to undergo, its convenience, and its side effects. METHODS: Women who had either an excisional or ultrasound-guided core needle breast biopsy in 1997 for a screen-detected lesion had telephone interviews 1 to 3 months after the biopsy. Bivariate associations were tested by using chi(2) and t test statistics. Mulitvariate analyses were used to control for effects of demographic characteristics. RESULTS: Most women (66%) could not remember being offered a choice of procedures, and of those who did have a choice, a higher proportion had an excisional biopsy. Only 2% reported being told the cost of the biopsy procedure. Women who had an excisional biopsy compared with those who had undergone a core needle biopsy reported statistically more hours and days off from work and reported more side effects 1 to 3 days after the biopsy (P<.05). Associations between side effects and type of biopsy procedure were unchanged when adjustment was made for demographic characteristics. CONCLUSION: Women who had the ultrasound-guided needle biopsy reported significantly fewer side effects and needed less time off from work. When a suspicious lesion is noticed on a screening mammogram, it is important that women and their physicians discuss the benefits and risks of the various biopsy procedures before deciding how to proceed, allowing for informed choice.

Biopsy↗

PubMed1992

HIV-1 in postmortem brain tissue from patients with AIDS: a comparison of different detection techniques.

OBJECTIVE: The presence of HIV-1 in postmortem brain tissue from 31 patients with AIDS and 12 HIV-1-negative controls was investigated. DESIGN: Most laboratories have access to the methods used. We readily applied in situ hybridization and immunohistochemistry to archival formalin-fixed paraffin-embedded (FFPE) brain specimens. METHODS: The techniques used to detect HIV-1 were explant culture, in situ hybridization with 35S-labeled polymerase (pol) gene riboprobes and immunohistochemistry with monoclonal antibody to gp41. RESULTS: HIV-1 was isolated from explant cultures in 13 out of 20 (65%) patients, whereas HIV-1-infected cells were detected in FFPE brain tissue from nine out of 26 (35%) patients examined by in situ hybridization and in seven out of 26 (27%) patients examined by immunohistochemistry. CONCLUSIONS: Although the isolation technique was the most sensitive of the three techniques tested, infected cells may be identified with in situ hybridization in conjunction with immunohistochemistry.

AIDS-Related Opportunistic Infections↗

PubMed2004

Paravaginal defects: prevalence and accuracy of preoperative detection.

The objective of this study was to determine the prevalence of paravaginal defects and to report the correlation between diagnosing a paravaginal defect preoperatively and observing the presence of one intraoperatively. This was a prospective study in which 77 patients with at least stage 2 prolapse of the anterior vaginal wall who desired surgical correction of their prolapse were assessed pre- and intraoperatively for the detection of a paravaginal defect. In order to differentiate a midline or central defect from a paravaginal defect, an index finger or ring forceps was placed vaginally toward each ischial spine separately. If the prolapse became reduced, the patient was clinically diagnosed with a paravaginal defect on that side. The intraoperative visualization or palpation of the pubocervical fascia detached from the arcus tendineus fasciae pelvis was used as the gold standard in diagnosing a paravaginal defect. The overall prevalence of a paravaginal defect in patients with at least stage 2 prolapse of the anterior vaginal wall was 37.7%. The sensitivities for detecting a left, right and bilateral paravaginal defect were 47.6, 40.0 and 23.5%, respectively, while the specificities for each side were 71.4, 67.3, and 80.0%, respectively. The overall prevalence of a paravaginal defect in patients with anterior vaginal wall prolapse is low. The standard clinical evaluation used to preoperatively detect a paravaginal defect in our hands is a poor predictor for the actual presence of a paravaginal defect.

Female↗

PubMed2003

Rapid and sensitive determination of phenol in honey by high-performance liquid chromatography with fluorescence detection.

The objective of this research was to develop a novel high-performance liquid chromatographic (HPLC) method involving a simple sample preparation procedure for the rapid, low-cost, and sensitive quantitation of phenol in honey at levels of regulatory and practical importance. After proper dilution of honey with water, the samples were analyzed by a gradient HPLC system, using a reversed-phase column with fluorescence detection at excitation and emission wavelengths of 270 and 300 nm, respectively. The eluents applied were water-acetonitrile-85% orthophosphoric acid (10:10:0.01, v/v/v) and water-85% orthophosphoric acid (20:0.01, v/v). The retention time of phenol was found to be 14.1 min, and the limit of quantitation for phenol in honey was set at 5 microg/kg. Overall recovery was 98%. The proposed method has been successfully applied to real sample analysis.

Chromatography, High Pressure Liquid↗

PubMed1997

Mycoplasma infection and rheumatoid arthritis: analysis of their relationship using immunoblotting and an ultrasensitive polymerase chain reaction detection method.

OBJECTIVE: To examine the relationship between infection with Mycoplasma and the development of rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA). METHODS: Immunoblotting of patient synovial fluid and sera on detergent-phase membrane protein extracts of various Mycoplasma species was carried out to learn whether patients exhibited serologic evidence of previous exposure to mycoplasmas. Moreover, an ultrasensitive polymerase chain reaction (PCR) method was developed for assessing whether Mycoplasma DNA could be detected in synovial fluid from patients and controls. RESULTS: Immunoblotting provided serologic evidence of previous Mycoplasma exposure in patients and controls. The genus-specific PCR detected known human Mycoplasma species and could reliably detect <5 copies of Mycoplasma hominis, Mycoplasma fermentans, or a molecular mimic control in synovial fluid. Repeat testing revealed no evidence of Mycoplasma DNA in patient synovial samples. CONCLUSION: This study provided serologic evidence suggesting that, while previous exposure to Mycoplasma was common, there was no detectable persistence of Mycoplasma DNA in the synovial fluid or tissue of patients with RA or JRA.

Adult↗

PubMed2003

Do women prefer to have screening tests for Down syndrome that have the lowest screen-positive rate or the highest detection rate?

OBJECTIVE: To assess whether women have a preference for Down syndrome screening test performance. METHODS: A structured questionnaire exploring women's preferences for screening test performance was administered to women attending their first prenatal visit who wished to have Down syndrome screening performed. RESULTS: One hundred and twenty women were interviewed. The majority of women (n=80) chose a screening test with a low screen-positive rate rather than the highest detection rate. The reasons given for this preference were a desire to minimise the risk of miscarriage of a normal baby and a belief that a detection rate of 80 to 90% was acceptable. However, older women (>37 years) chose a test with the highest detection rate possible, regardless of the higher screen-positive rate, preferring to miscarry a normal baby as a result of a diagnostic test rather than miss the detection of a baby with Down syndrome. Preferences were not influenced by previous screening experience. CONCLUSIONS: Women express different preferences for screening test performance. Maternal age rather than previous screening experiences appears to be the major influence in these choices.

Abortion, Spontaneous↗