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At least 109 records · Page 6Linked to original sources
PubMed2004

Design and preparation of oligonucleotide microarray for vaccinia virus detection.

OBJECTIVE: To study the preparation of oligonucleotide microarray for detecting vaccinia virus. METHODS: Oligonucleotide probes were designed and synthesized according to the specific genes of vaccinia virus. Sample DNA of the virus and the negative control sample were obtained and labeled by restriction display technique, followed by hybridization to the oligonucleotide microarray and scanned by Agilent scanner. RESULTS: Strong hybridization signals were detected from the viral DNA hybridized with the microarray, but were absent in the negative sample when positive probes were not used. CONCLUSION: Distinct differences in the hybridization signals between the virus sample and negative sample and between the samples obtained in different phase of infection demonstrate high specificity and sensitivity of the microarray for vaccinia virus detection.

Base Sequence↗
PubMed1993

Objective response detection.

Evoked potential threshold estimation can be made truly objective by using statistically based methods. In general, time domain analysis is preferable for responses which are impulsive (temporally narrow, spectrally broad), whereas frequency-domain analysis is more appropriate for tonal responses (spectrally narrow, temporally broad). In both time and frequency domains, methods comparing evoked potential power to noise models are robust and powerful. For spectrally narrow responses such as steady-state evoked potentials, the performance of magnitude-squared coherence, the ratio of grand average power to mean subaverage power, is superior to that of other methods for objective response detection.

Acoustic Stimulation↗
PubMed2000

Objective response detection in an electroencephalogram during somatosensory stimulation.

Techniques for objective response detection aim to identify the presence of evoked potentials based purely on statistical principles. They have been shown to be potentially more sensitive than the conventional approach of subjective evaluation by experienced clinicians and could be of great clinical use. Three such techniques to detect changes in an electroencephalogram (EEG) synchronous with the stimuli, namely, magnitude-squared coherence (MSC), the phase-synchrony measure (PSM) and the spectral F test (SFT) were applied to EEG signals of 12 normal subjects under conventional somatosensory pulse stimulation to the tibial nerve. The SFT, which uses only the power spectrum, showed the poorest performance, while the PSM, based only on the phase spectrum, gave results almost as good as those of the MSC, which uses both phase and power spectra. With the latter two techniques, stimulus responses were evident in the frequency range of 20-80 Hz in all subjects after 200 stimuli (5 Hz stimulus frequency), whereas for visual recognition at least 500 stimuli are usually applied. Based on these results and on simulations, the phase-based techniques appear promising for the automated detection and monitoring of somatosensory evoked potentials.

Adult↗
PubMed1996

Hill-Sachs lesion: sonographic detection.

OBJECTIVE: To determine the value of ultrasonography (US) in the detection of Hill-Sachs lesion of the humerus in comparison with double-contrast computed tomographic arthrography (CTA) and with arthroscopy. DESIGN AND PATIENTS: US and CTA were performed on 92 patients, 86 of whom subsequently underwent arthroscopy. The findings of US, CTA and arthroscopy in these 86 patients in the diagnosis of Hill-Sachs lesion were analyzed. RESULTS AND CONCLUSIONS: In the detection of Hill-Sachs lesion US showed a sensitivity of 91% (21 of 23), a specificity of 95% (60 of 63) and an accuracy of 94% (81 of 86) when compared with CTA, and a sensitivity of 94% (18 of 19), specificity of 91% (61 of 67) and accuracy of 91% (79 of 86) when compared with arthroscopy. In only 2% (2 of 86) of patients was there reduced visualization because of restriction of movement. Hill-Sachs lesion and its relationship to the humeral head can be reliably diagnosed with US.

Adult↗
PubMed2001

Performance of a new F-speed film for caries detection.

OBJECTIVE: To compare films from three speed groups for the detection of approximal caries. STUDY DESIGN: Insight, Ektaspeed Plus and Ultra-speed (Eastman-Kodak, Rochester, NY, USA) radiographs of the proximal surfaces of 40 extracted posterior teeth were evaluated by six observers. The presence or absence of caries was scored using a 5-point confidence scale. The actual status of each surface was determined from histology of ground sections. Observer responses were evaluated using ROC analysis and areas under the ROC curves (A(Z)) assessed using ANOVA. RESULTS: Ultra-speed film had a mean A(Z) of 0.88, Ektaspeed Plus 0.85, and Insight 0.84. These differences were not statistically significant (P=0.5). Differences between observers were also not statistically significant (P=0.42). CONCLUSIONS: The performance of the new F-speed film was not statistically different from E or D speed for caries detection. This film shows promise as a means of reducing patient dose while maintaining diagnostic quality.

Analysis of Variance↗
PubMed1996

Preoperative MR imaging in hyperparathyroidism: results and factors affecting parathyroid detection.

OBJECTIVE: To determine the sensitivity of MR imaging for the detection of abnormal parathyroid glands in patients with biochemical evidence of hyperparathyroidism and to identify the factors affecting detection. SUBJECTS AND METHODS: Between 1985, 82 patients with biochemical proof of hyperparathyroidism were referred for MR imaging of the parathyroid glands prior to surgery. Axial T1- (600/20 [TR/TE]) and T2-weighted (2500/40, 80) spin-echo images were obtained using an anterior neck surface coil. The interpretation of the MR image was compared with the findings at surgery and also correlated with gland histology, volume, and weight. Cases in which a false-positive or false-negative diagnosis was made were reviewed to determine the factors affecting detection. RESULTS: MR imaging detected 71 of 92 (77%) surgically proven abnormal glands (sensitivity, 77%; 95% confidence interval (CI), 68-86%) and misdiagnosed five (1.6%) of 314 normal glands as abnormal. There was no difference in the detection of enlarged glands in patients presenting for the first time (n = 71) (sensitivity, 77%; 95% CI, 66-86%) compared with patients with recurrent hyperparathyroidism (n = 12) (sensitivity, 77%; 95% CI, 46-95%). There was no significant difference in the detection of adenomas (sensitivity, 77%; 95% CI, 65-86%) compared with hyperplasia (sensitivity, 71%; 95% CI, 42-92%). Of five patients with ectopic parathyroid glands (1.6%), four had had previous surgery. All five glands were successfully located (three mediastinal, two in the neck). Factors contributing to a false-negative MR imaging diagnosis included small gland size and thyroid disease. Four of five false-positive diagnoses were due to enlarged lymph nodes being mistaken for parathyroid glands. CONCLUSIONS: MR imaging is an accurate technique for investigation of hyperparathyroidism. Pitfalls include low sensitivity for the identification of small glands, misinterpretation of enlarged lymph nodes as parathyroid adenomas, and misinterpretation because of thyroid disease. MR imaging is particularly useful in the investigation of patients who remain hypercalcemic following initial surgery.

Adult↗
PubMed2000

[Detection of lymphatic metastasis from malignant melanoma after identification of the sentinel node by preoperative lymphoscintigraphy and intraoperative radioisotopic detection].

OBJECTIVES: The aim of this study was to evaluate the detection of the first lymph node draining the primary tumour site, using a radioisotopic mapping alone and to determine whether a preoperative lymphoscintigraphy using technetium sulfur colloid and a hand-held gamma detecting probe could improve the detection of the sentinel lymph node (SLN) in melanoma. PATIENTS AND METHOD: From January to December 1998, 36 patients with a cutaneous melanoma larger than 0.75 mm, stage I TNM were included in this prospective study. Mean Breslow was 1.85 mm. The distribution of melanoma was head and neck (n = 9), trunk (n = 7), upper extremities (n = 4), lower extremities (n = 16). Preoperative lymphoscintigram and intraoperative detection were used. The first hot lymph node was supposed to be the SLN. RESULTS: In all cases, a lymph node was found and nine patients had more than one SLN (average number of SLN per patient: 1.25). Aberrant drainages were found in seven patients (19.4%): 1 in-transit lymph node, three paradoxical bassins, three bypasses). Four out of 36 patients had lymph node metastases and underwent elective lymph node dissection. CONCLUSION: The radio-isotopic technique used alone for the identification of the SLN is efficient in melanoma with a 100% detection rate in this short series.

Adult↗
PubMed2005

[Preparation of time-resolved fluoroimmunoassay kit for human alpha-fetoprotein detection].

OBJECTIVE: To prepare time-resolved fluoroimmunoassay (TRFIA) kit for detecting human alpha-fetoprotein (hAFP). METHODS: Sandwich TRFIA kit for hAFP detection was developed using monoclonal antibody of anti-AFP. RESULTS: AFP-TRFIA kit was capable of detecting AFP within the range of 1-1 000 U/ml with sensitivity of 0.17 U/ml and without cross-reactivity with CEA, CA12-5, CA15-3, or CA19-9. The intra- and inter-assay coefficients of variation were (3.3-5.9)% and (3.7-6.5)%, respectively. The prepared AFP-TRFIA reagent could withstand preservation at 4 degrees celsius; for 1 year and at 37 degrees celsius; for 7 days with the cutoff value of 12 U/ml in healthy subjects (n=426). The correlation coefficient of the detection results between this kit and commercially available AFP kit (Wallac OY, Finland) for 60 blood samples was 0.995. CONCLUSION: The prepared TRFIA kit for hAFP detection meets the demand of clinical application with good sensitivity, precision, specificity, stability and accuracy.

Fluoroimmunoassay↗
PubMed2005

[Quantitative fluorogenic real-time PCR assay for respiratory syncytial virus detection].

OBJECTIVE: To Establish a rapid and objective quantitative fluorogenic real-time PCR assay for early detection of human respiratory syncytial virus (hRSV). METHODS: Two pairs of primers and one TaqMan Fluorogenic probe that are specific for the recognition of the most conservative N gene of hRSV for virus detection with LighCycler PCR in 93 nasopharyngeal secretion specimens collected from infants and young children. The assay was compared with virus isolation, routine PCR, nested PCR, and enzyme-linked immunosorbent assay (ELISA). RESULTS: This TaqMan assay had a sensitivity of 1 x 10(2) cDNA copies/microl with a dynamic range between 1 x 10(2) and 1 x 10(7) cDNA copies/microl, which was the same as that of nested PCR, but 10 times more sensitive than routine PCR. The specificity of the assay was evaluated by comparing hRSV with polivirus type 1, coxsackie virus type 2, influenza A, influenza B and adenovirus type 7. A PCR product of the expected size (195 bp) was produced and fluorescence signal detected for hRSV, but not for any of the other viruses. The results in LightCycler and Rotor-Gene instrument were consistent. Forty-four specimens (43.9%) were hRSV-positive with this assay and 4 (4/93,4.3%) were hRSV-positive with ELISA, showing rather low correlation between the two methods. No visible relation was found between the concentration of hRSV RNA and severity of the disease. CONCLUSION: This assay is rapid, sensitive, specific and quantitative, and has the potential of wide application for early diagnosis of hRSV infection and evaluation of the therapeutic effect.

Child, Preschool↗
PubMed2007

FISH analysis of 15 chromosomes in human day 4 and 5 preimplantation embryos: the added value of extended aneuploidy detection.

OBJECTIVE: Screening for an increased number of chromosomes may improve the detection of abnormal embryos and thus contribute to the capability of preimplantation genetic screening (PGS) to detect the embryo(s) for transfer in IVF with the best chance for a healthy child. Good-quality day 4 and 5 embryos were analyzed after cryopreservation for the nine chromosomes mostly recommended for screening (13, 14, 15, 16, 18, 21, 22, X and Y), next to six additional chromosomes which are less well studied in this context (1, 2, 7, 6, 10 and 17). METHOD: The copy numbers of 15 chromosomes were investigated by fluorescence in situ hybridization (FISH) in three consecutive rounds. The proportion of aneuploid and mosaic embryos was determined and compared in retrospect to results in case only the recommended probe set had been analyzed. RESULTS: A total of 52 embryos from 29 infertile women were analyzed. Screening the embryos for six additional chromosomes increased the proportion of abnormal embryos from 67 to 81% (P = 0.03), owing to an increase in mosaic embryos. CONCLUSION: All but one of the meiotic aneuploidies found in this study would have been detected by the probe set most frequently used in PGS clinics. However, aneuploid cell lines originating from mitotic errors could be detected for almost all chromosomes, so screening of six additional chromosomes mainly increased the proportion of mosaic embryos. The added value of screening for six additional chromosomes in PGS for clinical practice will remain undetermined as long as the fate of mosaic embryos after transfer is unclear.

Aneuploidy↗
PubMed1995

An ultrasensitive immunoassay for prostate-specific antigen based on conventional colorimetric detection.

OBJECTIVE: Development of an ultrasensitive immunoassay for serum PSA involving conventional detection probes. DESIGN AND METHODS: The assay involves a polyclonal antibody immobilized in microtitration wells and a monoclonal antibody labeled with horseradish peroxidase. In a one-step assay, the enzymatic activity of the bound detection antibody is monitored by the addition of hydrogen peroxide/tetramethylbenzidine substrate reagent followed by spectrophotometric quantification of the conversion product. RESULTS: The assay has a lower detection limit of 0.003 micrograms/L, biological detection limit of 0.009 micrograms/L, and intra- and interassay CVs of 8.2% and 10.5% at PSA concentrations of 0.022 and 0.065 micrograms/L, respectively. The recovery of the assay averaged 104% and it demonstrated a dilution linearity down to at least 0.01 micrograms of PSA/L. Results of comparison data correlated well with those obtained by a well established enzyme immunoassay. The serum PSA concentrations were < 0.012 micrograms/L in the majority of patients (53.8%) who had undergone radical prostatectomy. CONCLUSIONS: This assay is well suited for post-surgical monitoring of PSA in patients with prostate cancer.

Antibodies↗
PubMed2004

Reproducibility of a multitarget stool-based DNA assay for colorectal cancer detection.

OBJECTIVES: Recent studies have demonstrated good sensitivity and specificity for the detection of colorectal cancer (CRC) utilizing a multitarget DNA assay panel (MTAP) on a single stool specimen. The aim of this study was to determine if analyzing three stool specimens obtained on three different days with the MTAP was superior to a single specimen for the detection of CRC. A secondary aim was to confirm the sensitivity of this MTAP reported in earlier studies. METHODS: Sixteen patients with newly diagnosed CRC underwent stool collection on three different days prior to surgical resection. Each specimen was analyzed using a MTAP that included 21 specific mutations of p53, K-ras and APC, and a microsatellite instability marker (BAT-26). RESULTS: Eleven of the sixteen patients (69%) had at least one mutation detected in their first stool specimen. Identical mutations were found in 18 of 21 (86%) subsequent stool specimens from patients initially positive. No new mutations were detected in these 21 specimens or 9 subsequent specimens from 5 patients initially negative. Overall, there was a 93% concordance between initial results and subsequent stools analyzed. CONCLUSION: There did not appear to be any additional benefit from performing the MTAP on more than one specimen per patient. This MTAP was reproducible with the same mutation detected in serial samples from each patient. The sensitivity detected in this study was comparable to earlier reports. Studies in an asymptomatic average-risk population are required to determine the role of the MTAP in CRC screening.

Adult↗
PubMed1991

Anal human papillomavirus infection: a comparative study of cytology, colposcopy and DNA hybridisation as methods of detection.

OBJECTIVE: To compare anal cytology, colposcopy and DNA hybridisation as methods of detecting anal HPV infection. SUBJECTS AND DESIGN: Patients attending: (1) a genitourinary medicine (GUM) clinic with ano-genital warts; (2) a surgical out-patient department with anal fissure or haemorrhoids were examined for evidence of anal HPV infection. RESULTS: Considering GUM clinic attenders, 17% (38/225) and 40% (90/225) had perianal or anal canal warts respectively. Colposcopic examination revealed anal acetowhite lesions without warts in 28% (63/225). Cytological evidence of HPV infection was found in 98%, 83%, and 90% of patients with anal canal warts, perianal warts and acetowhite lesions respectively. Anal intraepithelial neoplasia (AIN) was documented in 22% of patients with anal canal warts compared with 6% with perianal warts (p less than 0.01). HPV DNA was detected from the anal brushings of 71%, 50%, 32%, and 29% of patients with anal canal warts, perianal warts, acetowhite lesions and a normal anal examination respectively. HPV type 6/11 was detected in the majority of HPV positive samples. Considering surgical out-patient attenders with no history or signs of anal warts, 25% showed cytological evidence of anal HPV infection and HPV DNA was detected from anal brushings in 3% (2/71). CONCLUSION: Anal examination with the colposcope is a useful method for detecting subclinical HPV infection. Anal cytology may prove helpful for detecting AIN, however, since koilocytosis was rarely seen, the specificity of the cytological criteria for anal HPV infection in the absence of AIN is uncertain. DNA analysis of anal brushings proved only moderately sensitive.

Adult↗
PubMed2006

[Determination of rhodamine 123 in cell lysate by high-performance liquid chromatography with visible wavelength detection].

OBJECTIVE: To establish a high-performance liquid chromatography with visible wavelength detection method for rhodamine 123 in cell lysate. METHODS: The HPLC separation was performed on a Kromasil C(18) (5 microm, 4.6 mm x 250 mm) column, using water (15 mmol/L potassium acetate and 1.2 mmol/L tetrabutylammonium bromide) - acetonitrile (65:35) as the mobile phase. The wave length was 390 nm, the internal standard was rhodamine B. Protein in the sample was precipitated by trichloroacetic acid. RESULTS: The calibration curve was linear in the range of 3 - 300 microg/L. The intra-day and inter-day RSDs were less than 5%. CONCLUSION: The method is accurate,sensitive, simple, and reliable for determining rhodamine 123 in cell lysate.

Animals↗
PubMed2004

[Diagnosis of osseous metastases of malignant tumors by bone scanning combined with bone alkaline phosphatase detection].

OBJECTIVE: To assess the diagnostic value of bone alkaline phosphatase (B-AKP) detection in diagnosis of osseous metastases of malignant tumors. METHODS: Bone scanning and B-AKP detection were performed in 106 patients with malignancies. According to the findings in bone imaging and clinical symptoms, the patients were divided into bone metastases group (BM) and non-bone metastases group (NBM), between whom B-AKP was compared by t test. According to the number of osseous lesions on bone imaging, the patients were graded and B-AKP was compared between the 4 grades. Correlation analysis was performed between B-AKP level and the number of osseous lesions. RESULTS: Among the 106 patients, bone scanning found osseous metastases in 68 patients. For diagnosing osseous metastases, the sensitivity, specificity, PPV and NPV of B-AKP detection were 89.7%, 52.6%, 77.2% and 74.0%, respectively. B-AKP was 28.4+/-14.8 microg/L in BM group and 12.8+/-7.6 microg/L in NBM group, showing significant difference (t=6.056, P<0.001). B-AKP was 13.9+/-6.8 microg/L, 17.2+/-9.4 microg/L, 23.8+/-10.4 microg/L and 49.5+/-17.6 microg/L in patients of grade 0, 1, 2, and 3, respectively, showing significant difference by comparisons between the grades (P<0.05) except for that between grades 0 and 1 (t=1.320, P>0.05) and between grades 1 and 2 (t=1.803, P>0.05). B-AKP was 19.6+/-4.2 microg/L in patients with single hot focus and 13.1+/-3.4 microg/L in patients with single cold focus (t=2.570, P<0.05). Correlation analysis showed that there was low-degree correlation between B-AKP level and the number of osseous lesions (r=0.751, P<0.01). CONCLUSIONS: B-AKP level detection and bone imaging yield consistent results. For diagnosis of osseous metastases in patients with malignant tumor, bone scanning is the primary choice but in cases of single hot lesions, B-AKP should be performed to prevent missed diagnosis; for false positive lesions, B-AKP should also be detected to prevent misdiagnosis.

Adult↗
PubMed2004

Nature as a model for technical sensors.

Nature has developed a stunning diversity of sensory systems. Humans and many animals mainly rely on visual information. In addition, they may use acoustic, olfactory, and tactile cues for object detection and spatial orientation. Beyond these sensory systems a large variety of highly specialized sensors have evolved. For instance, some buprestid beetles use infrared organs for the detection of forest fires. The infrared sensors of boid and crotalid snakes are used for prey detection at night. For object detection and spatial orientation many species of nocturnal fish employ active electrolocation. This review describes certain aspects of the detection and processing of infrared and electrosensory information. We show that the study of natural exotic sensory systems can lead to discoveries that are useful for the construction of technical sensors and artificial control systems. Comparative studies of animal sensory systems have the power to uncover at least a small fraction of the gigantic untapped reservoir of natural solutions for perceptive problems.

Animals↗
PubMed2000

Culture as an influence on breast cancer screening and early detection.

OBJECTIVES: To explore how culture may play a part in breast cancer screening, early detection, and efforts to decrease breast mortality. DATA SOURCES: Journal articles published in the past 20 years on cultural aspects of cancer prevention and control. CONCLUSIONS: Research seems directed more at discovering cultural differences than at identifying similarities on how culture influences breast cancer screening and early detection. The influences of poverty and lack of educational opportunities account for much of what is termed cultural difference. IMPLICATIONS FOR NURSING PRACTICE: Improving practice through an informed understanding of culture calls for considerable self-education and a fundamental refinement of care delivery.

Adult↗
PubMedDate not supplied

Cine phase-contrast MR flow measurements: improved precision using an automated method of vessel detection.

OBJECTIVE: The purpose of this study was to construct a method of vessel edge detection that correctly identifies vessel pixels and to compare the interuser variability of cine phase contrast MR volumetric flow rates obtained with the conventional manual method and an automated method. MATERIALS AND METHODS: The automated method was developed based on a magnitude image threshold value and compared with the manual method in a flow phantom (three users) and in velocity images of the portal vein (five users). The threshold value determined from the magnitude image was applied to a region of interest surrounding the vessel of interest on the magnitude image to construct a vessel edge detection mask m(x,y). The velocity images were then multiplied by the mask m(x,y) and volumetric flow rates determined using the identified vessel pixels. RESULTS: In the flow phantom, flow measurements with the magnitude threshold method had significantly less interuser variability compared with the manual method (p < 0.01) and were within 10% (mean 6.0%) of the actual flow versus 35% (mean 18.6%) with the manual method. Regarding flow measurements in the portal vein of six volunteers, the magnitude threshold method was significantly more precise (p < 0.01) than the manual method with a mean standard deviation between the five users of 40.4 +/- 12.9 ml/min (range 22-60 ml/min) and 110.4 +/- 32.7 ml/min (range 70-155 ml/min), respectively. CONCLUSION: The magnitude threshold method of vessel edge detection developed in this study yields flow measurements that are accurate in the model system and have significantly less interuser variability than the manual method. This method shows promise for improving the precision of cine phase contrast flow measurements.

Adult↗