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Biomedical subjects

R Taira

Publications and source records attributed to R Taira.

10 recordsLinked to original sources
PubMed2001

Fluctuations of Emax of the left ventricle: effect of atrial natriuretic polypeptide.

Recently the circadian rhythm of fluctuations in heart rate variability (HRV) has gained increasing attention, and the use of appropriate treatment corresponding to the circadian rhythm has become an important issue. However, the question has been raised as to whether the rhythm of fluctuation is only limited to HRV, and if a rhythm is also present in the contraction of the heart. The mathematical technique of electrical circuit simulation of the cardiovascular system was used to observe the Emax rhythm. In this study, the therapeutic effect of various drugs, including atrial natriuretic polypeptide (ANP), was confirmed. The effect of inotropic drugs including ANP on Emax was observed, and the results based on an old and a new method of determining Emax . were examined. Furthermore, the chaos analysis of Emax was also made. The time series of Emax showed an increased complexity due to the administration of ANP. In conclusion, it might be important to consider not only the fluctuation of HRV, but also an analysis of the fluctuation in the contraction of the heart.

Adrenergic beta-Antagonists↗
PubMed2001

Structure localization in brain images: application to relevant image selection.

Recent advances in imaging have lead to increases in the number of images/study. Automated methods to select relevant images are critical to effectively convey study results. The proposed method combines natural language processing (NLP) and automatic structure localization to identify relevant images of a MR brain study. NLP extracts relevant locations of findings. Two algorithms were implemented and evaluated for structure localization. The first method involves registration of patient dataset to a labeled atlas. The second method involves an eigenimage search using a training set of images. A prototype was developed and tested on MR brain studies of nine patients. With the registration method, slices containing the relevant structure agreed with expert selection in 98% of cases. Structure localization by eigenimage search was able to locate the lateral ventricles correctly in all the test cases. The proposed method provides an accurate method for identifying relevant slices of an imaging study.

Algorithms↗
PubMed2000

Improving the quality of care through routine teleradiology consultation.

RATIONALE AND OBJECTIVES: The hypotheses of this study were as follows: (a) University subspecialty radiologists can provide consultations effectively to general radiologists as part of routine clinical operations; (b) these consultations will improve the quality of the final radiologic report; and (c) the consultations will improve the care process and may save money, as well. MATERIALS AND METHODS: For 2,012 consecutive computed tomographic or magnetic resonance (MR) imaging studies, the initial interpretations provided by radiology generalists were subsequently reviewed by specialists, with a final consensus report available. "Truth" was established by final consensus reports. To control for potential bias, 150 adult MR imaging and 250 pediatric radiologic studies were interpreted initially by specialists and then by generalists. Again, truth was established by final consensus reports. RESULTS: There was disagreement between generalist and specialist radiologist interpretations in 427 (21.2%) of the cases reviewed. These disagreements were stratified further by independent specialists, who graded them as important, very important, or unimportant. Differences were considered important or very important in 99% of the cases reviewed. CONCLUSION: Consultations by subspecialty radiologists improved the quality of the radiology reports studied and, at least in some cases, improved the process of care by eliminating unnecessary procedures or suggesting more specific follow-up examinations. The consultation services can be provided cost-effectively from the payer's perspective and may save additional costs when unnecessary procedures can be eliminated.

Humans↗
PubMed2000

Interactive software for generation and visualization of structured findings in radiology reports.

OBJECTIVE: Our objectives were to develop a user-friendly graphic interface for a module that integrates traditional radiology reporting, natural language processing, and editing capabilities; to facilitate the structuring of radiology reports as part of routine clinical practice; to use a commercial speech recognition module for online transcription; and to implement the module in a hardware-independent environment. CONCLUSION: After implementation, the module was tested with 150 chest radiology reports by two radiologists and assessed for ease of use and accuracy. Overall, accuracy was close to 90% and user satisfaction was high. When radiology reports are structured as a part of routine clinical practice, it is possible to accomplish intelligent indexing and retrieval to facilitate teaching and research.

Medical Records Systems, Computerized↗
PubMed1999

[Laboratory-based evaluation of DainaScreen TPAb to detect specific antibodies against Treponema pallidum].

A newly developed immunochromatography assay, DainaScreen TPAb (Dainabot, Tokyo), to detect antibodies specific to Treponema pallidum was evaluated. When we tested serum and plasma samples of Syphilis Mixed Titer Performance Panel PSS201 (Boston Biomedica, Inc. , Bridgewater, MA, U.S.A.), all the test results obtained by DainaScreen TPAb were comparable to those determined by fluorescent treponemal antibody absorption test (FTA-ABS). Both within-run and day-to-day variation tests were highly precise, and no discrepant interpretation was obtained by the different medical technicians performed. Also, the testings of whole blood and plasma for individual samples gave same interpretations. The minimum detectable antibody titer was equal to that of Mediace TPLA (Sekisui Chemicals, Osaka) determined by Behring Nephelometer Analyzer (Dade Behring, Marburg, Germany). All the test results by DainaScreen TPAb for clinical serum samples were comparable to those by Mediace TPLA. With these results, we can conclude that DainaScreen TPAb is a rapid, practical and easy-to-perform alternative to detect antibodies specific to Treponema pallidum, in particular as being a point-of-care testing.

Antibodies, Bacterial↗
PubMed1995

High proportion of false positive reactions among donors with anti-HCV antibodies in a low prevalence area.

Among 39,656 voluntary blood donors in Okinawa Prefecture, Japan, 115 (0.29%) were repeatedly reactive for antibody to hepatitis C virus (anti-HCV) by second generation (2nd-gen) passive hemagglutination assay (PHA). Positive serum samples were tested for anti-HCV using three different enzyme immunosorbent assays (ELISAs; Abbott 2nd EIA, UBI-HCV-EIA, JCC-2) and for HCV-RNA by the polymerase chain reaction (PCR). The 115 2nd-gen PHA-positive sera were divided into three groups according to the agglutination titers; > 2(10) (high titer group), 2(7)-2(9) (median), 2(5)-2(6) (low). All but one serum (44/45) in the high PHA titer group reacted in each of the three second screening ELISAs. Furthermore, 43 (97.7%) of the 44 sera contained HCV-RNA by PCR. In the median titer group, 11 of the 13 samples tested were positive by each of the three ELISAs, and 4 (36.4%) of the 11 showed reaction by PCR. On the other hand, all of the 38 sera tested in the low titer group were negative for HCV-RNA by PCR, and 24 of the 38 were also negative by each of the three ELISAs. Most of the low titer positive reactions in the 2nd-gen agglutination assay seemed to be false positive. In Okinawa Prefecture, the prevalence of anti-HCV among blood donors is much lower than in the rest of Japan (0.29% vs. 1.11%). Moreover, a significant proportion of these sera were low titer by the PHA assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Donors↗
PubMed1995

Data clustering and other archive retrieval strategies for teleradiology and picture archiving and communication systems.

A key advantage in the conversion from film-based to digital radiology is the possibility of a long-term on line electronic archival of patient studies. The popular approach based on optical disk jukeboxes for the long-term archive and magnetic disk storage for data caching is not economically attractive because of the cost of both the jukebox and the medium. Strategies for extending the archival system design with a tape jukebox have been studied. The proposed strategy calls for the use of high-ratio lossy compression together with low-cost tape storage to make long-term on line archiving more affordable. An intelligent prefetching algorithm based on hospital information system and radiologic information system triggers, which in turn are augmented by manual case preparation, can effectively overcome the longer latency of ad hoc retrievals. This longer latency is caused by both system-level bottlenecks and the sequential access constraint of the tape drive. Strategies for image clustering and tape allocation by patient classification also enhance retrieval efficiency. This archival design using image compression, prefetching, and clustering could be implemented in many of the existing teleradiology and picture archiving and communication systems.

Algorithms↗