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PubMed1984

Alkaline reflux esophagitis in gastroresected patients. Objective detection with a simple isotope method.

The incidence and severity of alkaline reflux esophagitis occurring in 1129 gastroresected patients were evaluated. As far as the incidence of esophagitis are concerned, no significant difference was found after Billroth I or Billroth II type resection. Severe esophagitis developed in 62.6 per cent of patients with total gastrectomy, but never occurred when a long limb Roux-en-Y anastomosis was also performed. The majority of esophagitis was recognized within the first year after resection, so it might be supposed that not only operative procedure itself but the postoperative care period might be responsible for the development of esophagitis. It can be avoided and treated by Roux-en-Y anastomosis. Scintigraphy is a simple rapid method in the detection of gastroesophageal reflux, thus patients can be selected by it for further invasive investigation.

Duodenogastric Reflux↗
PubMed2000

Detection of object motion by a fly neuron during simulated flight.

Object detection on the basis of relative motion was investigated in the fly at the neuronal level. A representative of the figure detection cells (FD-cells), the FD1b-cell, was characterized with respect to its responses to optic flow which simulated the presence of an object during translatory flight. The figure detection cells reside in the fly's third visual neuropil and are believed to play a central role in mediating object-directed turning behaviour. The dynamical response properties as well as the mean response amplitudes of the FD1b-cell depend on the temporal frequency of object motion and on the presence or absence of background motion. The responses of the FD1b-cell to object motion during simulated translatory flight were compared to behavioural responses of the fly as obtained with identical stimuli in a previous study. The behavioural responses could only partly be explained on the basis of the FD1b-cell's responses. Further processing between the third visual neuropil and the final motor output has to be assumed which involves (1) facilitation of the object-induced responses during translatory background motion at moderate temporal frequencies, and (2) inhibition of the object-induced turning responses during translatory background motion at high temporal frequencies.

Animals↗
PubMed2000

Automatic detection of foreign objects in computed radiography.

This paper presents an effective two-step scheme for automatic object detection in computed radiography (CR) images. First, various structure elements of the morphological filters, designed by incorporating available morphological features of the objects of interest including their sizes and rough shape descriptions, are used to effectively distinguish the foreign object candidates from the complex background structures. Second, since the boundaries of the objects are the key features in reflecting object characteristics, active contour models are employed to accurately outline the morphological shapes of the suspicious foreign objects to further reduce the rate of false alarms. The actual detection scheme is accomplished by jointly using these two steps. The proposed methods are tested with a database of 50 hand-wrist computed radiographic images containing various types of foreign objects. Our experimental results demonstrate that the combined use of morphological filters and active contour models can provide an effective automatic detection of foreign objects in CR images achieving good sensitivity and specificity, and the accurate descriptions of the object morphological characteristics.

Algorithms↗
PubMed1992

Orthopteran DCMD neuron: a reevaluation of responses to moving objects. II. Critical cues for detecting approaching objects.

1. We examine the critical image cues that are used by the locust visual system for the descending contralateral motion detector (DCMD) neuron to distinguish approaching from receding objects. Images were controlled by computer and presented on an electrostatic monitor. 2. Changes in overall luminance elicited much smaller and briefer responses from the DCMD than objects that appeared to approach the eye. Although a decrease in overall luminance might boost the response to an approaching dark object, movement of edges of the image is more important. 3. When two pairs of lines, in a cross-hairs configuration, were moved apart and then together again, the DCMD showed no preference for divergence compared with convergence of edges. A directional response was obtained by either making the lines increase in extent during divergence and decrease in extent during convergence; or by continually increasing the velocity of line movement during divergence and decreasing velocity during convergence. 4. The DCMD consistently gave a larger response to growing than to shrinking solid rectangular images. An increase compared with a decrease in the extent of edge in an image is, therefore, an important cue for the directionality of the response. For single moving edges of fixed extent, the neuron gave the largest response to edges that subtended 15 degrees at the eye. 5. The DCMD was very sensitive to the amount by which an edge traveled between frames on the display screen, with the largest responses generated by 2.5 degrees of travel. This implies that the neurons in the optic lobe that drive this movement-detecting system have receptive fields of about the same extent as a single ommatidium. 6. For edges moving up to 250 degree/s, the excitation of the DCMD increases with velocity. The response to an edge moving at a constant velocity adapts rapidly, in a manner that depends on velocity. Movement over one part of the retina can adapt the subsequent response to movement over another part of the retina. 7. For the DCMD to track and continue to respond to the image of an approaching object, the edges of the image must continually increase in velocity. This is the second important stimulus cue. 8. Edges of opposite contrasts (light-dark compared with dark-light) are processed in separate pathways that inhibit each other. This would contribute to the reduction of responses to wide-field movements.

Adaptation, Physiological↗
PubMed2000

[Detection of hepatitis C virus RNA in the tissue of hepatocellular carcinoma by multiple detection system].

OBJECTIVE: Detection of hepatic HCV RNA in hepatocellular carcinoma (HCC) is difficult, since its expression is very low. Several techniques have been established. However, false positive and negative rates still exist. In this study, we applied several conventional and recently developed detection systems to determine the exact effect of HCV RNA on the development of RCC. METHODS: Immunohistochemistry for HCV core antigen and in situ hybridization for HCV RNA had been performed in 39 cases of HCC. IS-RT-PCR was applied for detection and localization of HCV RNA. We extracted microdissected liver tissues to detect HCV RNA separately in cancerous and pericancerous tissues so that the microscopic origin of the amplicons could be controlled. The serological tests including ELISA and RT-PCR for HCV also were performed in all cases. RESULTS: The positive rate by ELISA (30.8%) was not always consistent with that by RT-PCR(43.6%)from serum samples. The latter was much more sensitive and accurate to reflect existence of HCV RNA. Immunohistochemistry showed expression of RCV core antigen in 15 of 39 HCC cases. In pericancerous tissues, the signals were mainly localized in the cytoplasm of hepatocytes. However, translocated expression of HCV core protein was observed in the nuclei of tumor cells, the translocated rate was 73.3%. According to IS-RT-PCR, the positive signals were located mainly in the cytoplasm of cancer cells, the positive rate in HCC was 53.8%, expression of HCV RNA, serum HCV RNA level was detected to be low or negative. This suggested that serum HCV RNA was not always a good reflection of hepatic HCV RNA in HCC tissues. The microdissection RT-PCR described here gave an equal positive rate (59.0%) of HCV RNA in cancerous and pericancerous tissues. CONCLUSIONS: The high detection rate of HCV RNA in HCC specimens even from seronegative patients confirms the important role of HCV RNA during malignant transformation. IS-RT-PCR is a good detection and localization method to visualize HCV RNA in HCC tissues. The microdissection RT-PCR method has a distinct advantage and we anticipate this method will provide an important evidence to determine whether HCV play a direct or indirect role in hepatocarcinogenesis.

Adult↗
PubMed1999

[Annual chest X-ray in patients after treatment for laryngeal or oral cancer: only a limited number of second primary lung cancers detected].

OBJECTIVE: To evaluate the detection of second primary lung cancer in patients treated for laryngeal or oral cancer by means of the current annual chest radiography screening program. DESIGN: Retrospective follow-up. METHOD: In a source population of Utrecht University Hospital consisting of patients treated for laryngeal or oral cancer, the occurrence of non-simultaneous second primary lung cancer was analysed. The charts of the patients who developed second primary lung cancer were reviewed with respect to diagnosis (either by means of routine annual chest radiography or triggered by symptoms and signs) and treatment of lung cancer. A Kaplan-Meier survival analysis was performed for both routes of diagnosis and for each form of lung cancer treatment. RESULTS: The source population consisted of 2067 patients. Second primary lung cancer was diagnosed in 44 patients (37 with laryngeal and 7 with oral cancer). In 21 patients lung cancer was diagnosed by means of annual chest radiography (routine group). The remaining 23 patients presented with symptoms and signs (symptomatic group). In 13 patients, surgery with curative intent was performed. These patients had the best prognosis. Of the surgical cases, 12 out of 13 patients (27% of the total of 44) were in the routine group. Patients in the routine group had better survival than those in the symptomatic group. CONCLUSION: In view of the limited number of patients with second primary lung cancer and the small percentage of patients eligible for curative surgical treatment detected by annual radiography, screening in its present form is of little benefit.

Humans↗
PubMed1990

Influence of visual blur on object-motion detection, self-motion detection and postural balance.

We have compared the influence of visual blurring (either by use of plastic foils or by plus lenses) on detection of object-motion and self-motion, and on visual control of postural balance. Three experiments were performed--in all of which object-motion and self-motion detection latencies (response times) and postural sway (sway path) increased with increasing visual blurring. We conclude that visual blurring either by foils or by glasses affects object- and self-motion perception and postural sway in a similar way.

Attention↗
PubMed1995

The influence of prostate size on cancer detection.

OBJECTIVES: To determine if cancer detection rates vary with prostate size using a sextant core biopsy pattern. METHODS: We reviewed 1021 transrectal ultrasound (TRUS)-guided sextant pattern prostate biopsies to determine if cancer detection varied based on prostate size. Prostate size was determined using a computer generated elliptical estimation method. Sextant core biopsies were taken, and the patients divided into groups based on estimated size of the prostate and biopsy outcome. Large prostates were those that were estimated by TRUS as 50 cc or more. Prostates were considered small if they were less than 50 cc. Groups were compared based on size and biopsy outcome. RESULTS: Adenocarcinoma was detected in 33% (334 of 1021) of the patients. Large prostates were noted in 34% (346 of 1021), of which 23% (80 of 346) had cancer detected by sextant biopsy. Small prostates were noted in 66% (675 of 1021), of which 38% (254 of 675) had cancer detected. The difference in cancer detection in large and small glands using a sextant pattern was statistically significant (P < 0.01). Patients with positive biopsies had significantly smaller prostate sizes (40 cc +/- 26) when compared with those with negative biopsies (51 cc +/- 33) (P < 0.01). Only 14% (8 of 58) of patients with gland sizes 100 cc or greater had positive sextant biopsies while 49% (118 of 239) with prostates 25 cc or less had cancer detected. Multivariate statistical analysis was used to control for differences in age, prostate-specific antigen (PSA), PSA density, TRUS findings, and digital rectal examination between the large and small prostate groups. The difference in cancer detection persisted (P < 0.05) CONCLUSIONS: Currently no evidence exists to support differing cancer rates based on gland size alone. Our cancer detection rate using a sextant pattern was higher in men with prostates less than 50 cc, and patients diagnosed with cancer had significantly smaller prostates than those with a negative sextant biopsy. Our data suggest that significant sampling error may occur in men with large glands, and more biopsies may be needed under these circumstances. The effects of tumor volume, focality, and specimen size in relation to overall gland size may contribute to these findings.

Adenocarcinoma↗
PubMed1998

Detection of small low-contrast objects in mammography: effect of viewbox masking and luminance.

OBJECTIVE: Viewing conditions can affect an observer's performance in object detection. Our objective was to determine the effect of viewbox masking and luminance on the detection of small low-contrast objects revealed by mammography. MATERIALS AND METHODS: Mammographic contrast-detail images having various film densities were viewed on masked and unmasked viewboxes. Similar images with fixed film contrast and density were viewed when luminance ranged from 250 to 8000 nits (1 nit = 1 cd/m2). RESULTS: Detection of small low-contrast objects was significantly easier using a masked viewbox with high luminance that using a regular unmasked viewbox. When a regular viewbox (approximately 3000 nits) was used masking had a more significant effect on films with high optical densities than on films with low optical densities. Brighter, masked viewboxes improved detection on films with higher optical densities. CONCLUSION: Better detection of small low-contrast objects results when mammographic images are masked and viewed on high-luminance viewboxes than when a regular unmasked viewbox is used.

Female↗
PubMed2003

Rapid preparation of DNA microarray using PCR for hepatitis B and D virus detection.

OBJECTIVE: To prepare DNA microarray for detecting both hepatitis B and D virus as (HBV and HDV). METHODS: With the assistance of Oligo6.4 software, specific PCR primers targeting the conserved region of HBV and HDV were designed. The PCR products were purified and cloned into the pMD18-T vectors, followed by rapid identification. The recombinant plasmids were then extracted from positive clones and the target gene fragments underwent sequence analysis. RESULTS: The gene fragments of HBV and HDV were obtained by PCR, which were confirmed by sequence analysis to be specific gene fragments of HBV and HDV. CONCLUSION: Using PCR amplification products to prepare the DNA microarray is quick, simple and effective.

Hepatitis B virus↗
PubMed1996

Screening for cervical intraepithelial neoplasia grade 2/3: validity of cytologic study, cervicography, and human papillomavirus detection.

OBJECTIVE: A commercial test for human papillomavirus detection (hybrid capture assay) was examined for its potential value to augment the sensitivity of cytologic study or cervicography for screening for cervical intraepithelial neoplasia grade 2/3. STUDY DESIGN: In a cohort of 967 women with a mean age of 37.1 years who underwent routine cytologic screening, cytologic examination, cervicography, and testing for high-risk human papillomavirus by the hybrid capture assay were compared for their ability to detect cervical intraepithelial neoplasia grade 2/3. Cervical punch biopsy specimens were taken in 20.5% (198/967) patients because they had an atypical or positive cervigram or abnormal cytologic results in the primary screening smears. The data were analyzed by two-tailed chi(2) and Fisher's exact test. RESULTS: Thirty-eight patients were diagnosed with cervical intraepithelial neoplasia grade 2/3 (prevalence 3.9%) by histologic study. Cytologic study identified 29%, cervicography 45%, and testing for high-risk human papillomavirus 50% of cervical intraepithelial neoplasia grade 2/3. When combined, detection of high-risk human papillomavirus or cervicography augmented sensitivity of cytologic study to 58% (p = 0.01) with positive predictive values of 23% and 17%, respectively. Results of the different techniques should be interpreted in relationship to each other and not as absolute values because collection of specimens for cytologic study was done with cotton swabs, which may be suboptimal for screening but is general practice in Germany. CONCLUSIONS: Screening for cervical intraepithelial neoplasia grade 2/3 can significantly be improved by human papillomavirus testing with the hybrid capture assay.

Adolescent↗
PubMed2002

Persistence of placenta previa according to gestational age at ultrasound detection.

OBJECTIVE: To evaluate gestational age at ultrasound detection of placenta previa as a predictor of previa persistence until delivery, and to estimate the effects of previa type, parity, and prior cesarean delivery on previa persistence. METHODS: This was a retrospective cohort study of pregnancies with placenta previa detected during transabdominal or endovaginal ultrasound examination. Previa was categorized as complete if the placenta completely covered the internal cervical os or incomplete if the inferior placental edge partially covered or reached the margin of the os. Gestational age was grouped into 4-week intervals from 15 to 36 weeks. The outcome was cesarean delivery for persistent previa. RESULTS: Previa was detected during 940 ultrasound examinations in 714 pregnancies. Of those with placenta previa at 15-19 weeks, 20-23 weeks, 24-27 weeks, 28-31 weeks, and 32-35 weeks, previa persisted until delivery in 12%, 34%, 49%, 62%, and 73%, respectively. At each interval, complete previa was more likely to persist than incomplete previa, all P <.001. Prior cesarean delivery was an independent risk factor for persistent previa among women diagnosed with previa in the second trimester, P <.05. However, parity was not an independent risk factor for persistence at any gestational age interval after adjusting for prior cesarean delivery. CONCLUSION: Gestational age at ultrasound detection of placenta previa may be used to predict likelihood of previa persistence. After midpregnancy, risk of persistence appears to be higher than previously reported. Type of placentation and prior cesarean delivery are important factors that modify the risk that previa will complicate delivery.

Cesarean Section↗
PubMed2002

Hydramnios: anomaly prevalence and sonographic detection.

OBJECTIVE: To characterize the prevalence and ultrasound detection of fetal anomalies in pregnancies with hydramnios, and to estimate anomaly and aneuploidy risks when no sonographic abnormality is noted. METHODS: This was a retrospective cohort study of singleton pregnancies with hydramnios. Hydramnios was categorized as mild, moderate, or severe based on greatest amniotic fluid index of 25.0-29.9 cm, 30.0-34.9 cm, or 35.0 cm or more, respectively. Antenatal anomaly detection was compared with assessment in the immediate neonatal period. Aneuploidy and fetal deaths were analyzed separately. RESULTS: Hydramnios was diagnosed in 672 pregnancies, and 77 (11%) of neonates had one or more anomalies. Though more severe hydramnios was associated with higher likelihood of anomaly (P <.001), sonographic anomaly detection (79%) did not differ according to degree of hydramnios (P =.4). Of anomalies which eluded sonographic diagnosis, cardiac septal defects, cleft palate, imperforate anus, and tracheoesophageal fistula were the most frequent. If sonographic evaluation was normal, the risk of a major anomaly was 1% with mild hydramnios, 2% with moderate hydramnios, and 11% with severe hydramnios (P <.001). Aneuploidy was present in 10% of fetuses with sonographic anomalies and 1% without apparent sonographic anomalies. The fetal death rate was 4% in the setting of hydramnios; 60% of these cases had anomalies. CONCLUSION: The anomaly detection rate in pregnancies with hydramnios was nearly 80%, irrespective of the degree of amniotic fluid increase. Residual anomaly risk after normal sonographic evaluation was 2% or less if hydramnios was mild or moderate and 11% if severe.

Adult↗
PubMed1997

Prostatic asymmetry as a risk factor for prostatic carcinoma: serial prostate-specific antigen monitoring and cancer detection.

OBJECTIVE: To compare the rates of cancer detection in men with a normal, asymmetric, or suspicious prostate on digital rectal examination (DRE) initially and after 3 years of serial monitoring of prostate specific antigen (PSA) level. PATIENTS AND METHODS: Prostatic 'asymmetry' was defined as asymmetric growth of the lateral lobes of the prostate without induration or nodules, as assessed by a DRE. The study included 963 men with no clinical evidence of prostate cancer and whose serum PSA levels were monitored at 4 month intervals. Prostatic biopsy was recommended if the PSA level became persistently abnormal (> 4ng/mL) or increased by > 20% after having been initially abnormal. Cancer detection rates were compared among groups categorized by the initial DRE findings and serum PSA level. RESULTS: On comparing groups with suspicious and normal DREs, and abnormal with normal PSA levels both, as expected, were associated with a statistically significant increase in cancer detection. However, an asymmetric prostate did not carry an increased risk of detecting prostate cancer when compared with a normal prostate, regardless of PSA level. CONCLUSIONS: An asymmetric prostate does not appear to be an independent risk factor for detecting prostate cancer. Therefore, an asymmetric prostate with no abnormality in PSA level should not mandate prostatic biopsy, or even an increase in monitoring frequency above the presently recommended annual interval.

Aged↗
PubMed2003

[New improved approaches for DYS385 detection].

OBJECTIVE: To establish more sensitive methods for detection of DYS385 in routine forensic casework. METHODS: The primers recommended by Genome Database (GDB) and Schneider were used to amplify DYS385 respectively. Then, a semi-nested PCR of DYS385 was designed by using the two different primers as outer and inner primer. A series of experiments were carried out to achieve good result by adjusting the ratio of outer/inner primer and optimizing the PCR condition. RESULTS: It showed that an overall 112 bp shorter DYS385 fragments and better electrophoretic separation were obtained by using primer2B. By using the semi-nested PCR approach, the shorter specific DYS385 fragments could be amplified and detectable DNA amounted to 50 pg. CONCLUSION: This method is 20 fold more sensitive than the ordinary method.

Chromosomes, Human, Y↗
PubMedDate not supplied

Automated tuberculosis detection.

OBJECTIVE: To measure the accuracy of automated tuberculosis case detection. SETTING: An inner-city medical center. INTERVENTION: An electronic medical record and a clinical event monitor with a natural language processor were used to detect tuberculosis cases according to Centers for Disease Control criteria. MEASUREMENT: Cases identified by the automated system were compared to the local health department's tuberculosis registry, and positive predictive value and sensitivity were calculated. RESULTS: The best automated rule was based on tuberculosis cultures; it had a sensitivity of .89 (95% CI.75-.96) and a positive predictive value of .96 (.89-.99). All other rules had a positive predictive value less than .20. A rule based on chest radiographs had a sensitivity of .41 (.26-.57) and a positive predictive value of .03 (.02-.05), and rule the represented the overall Centers for Disease Control criteria had a sensitivity of .91 (.78-.97) and a positive predictive value of .15 (.12-.18). The culture-based rule was the most useful rule for automated case reporting to the health department, and the chest radiograph-based rule was the most useful rule for improving tuberculosis respiratory isolation compliance. CONCLUSIONS: Automated tuberculosis case detection is feasible and useful, although the predictive value of most of the clinical rules was low. The usefulness of an individual rule depends on the context in which it is used. The major challenge facing automated detection is the availability and accuracy of electronic clinical data.

Diagnosis, Computer-Assisted↗
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↗