Outbreak of histoplasmosis among cavers attending the National Speleological Society Annual Convention, Texas, 1994.
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In June 1994, 18 people developed serologically confirmed histoplasmosis following cave exploration associated with the annual National Speleological Society Convention in Bracketville, Texas. Six others had an undiagnosed illness suspected to be histoplasmosis. Two persons were hospitalized. We conducted a survey of convention attendees and a nested case-control study of those entering caves. We also conducted a histoplasmin skin test survey of a subgroup of the society, the Texas Cavers Association, who were attending a reunion in October 1994. Among the national convention attendees, exposure to two caves was identified as responsible for 22 (92%) of the 24 cases; 12 (75%) of 16 people exploring one cave (Cave A) and 10 (77%) of 13 exploring a separate cave (Cave B) developed acute histoplasmosis. Additional risk-factors included fewer years of caving experience, longer time spent in the caves, and entering a confined crawl space in Cave A. Of 113 participants in the separate skin test survey, 68 (60%) were found to be skin test positive, indicating previous exposure to Histoplasma capsulatum. A positive skin test was significantly associated with male sex and more years of caving experience. Those less experienced in caving associations should be taught about histoplasmosis, and health care providers should pursue histories of cave exposure for patients with bronchitis or pneumonia that does not respond to initial antibiotic therapy. (+info)
Enabling, empowering, inspiring: research and mentorship through the years.
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The interrelationship between research and mentorship in an association such as the Medical Library Association (MLA) is revealed through the contributions of individuals and significant association activities in support of research. Research is vital to the well-being and ultimate survival of health sciences librarianship and is not an ivory tower academic activity. Mentorship plays a critical role in setting a standard and model for those individuals who want to be involved in research and, ultimately, for the preparation of the next generation of health sciences librarians. Research and mentorship are discussed in the context of personal experiences, scholarship, and problem solving in a practice environment. Through research and mentorship, we are enabled to enhance our services and programs, empowered to look beyond our own operations for information puzzles to be solved, and inspired to serve society by improving health. (+info)
American College of Cardiology/ European Society of Cardiology international study of angiographic data compression phase II. The effects of varying JPEG data compression levels on the quantitative assessment of the degree of stenosis in digital coronary angiography.
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OBJECTIVES: This report describes whether lossy Joint Photographic Experts Group (JPEG) image compression/decompression has an effect on the quantitative assessment of vessel sizes by state-of-the-art quantitative coronary arteriography (QCA). BACKGROUND: The Digital Imaging and Communications in Medicine (DICOM) digital exchange standard for angiocardiography prescribes that images must be stored loss free, thereby limiting JPEG compression to a maximum ratio of 2:1. For practical purposes it would be desirable to increase the compression ratio (CR), which would lead to lossy image compression. METHODS: A series of 48 obstructed coronary segments were compressed/decompressed at CR 1:1 (uncompressed), 6:1, 10:1 and 16:1 and analyzed blindly and in random order using the QCA-CMS analytical software. Similar catheter and vessel start- and end-points were used within each image quartet, respectively. All measurements were repeated after several weeks using newly selected start- and end-points. Three different sub-analyses were carried out: the intra-observer, fixed inter-compression and variable inter-compression analyses, with increasing potential error sources, respectively. RESULTS: The intra-observer analysis showed significant systematic and random errors in the calibration factor at JPEG CR 10:1. The fixed inter-compression analysis demonstrated systematic errors in the calibration factor and recalculated vessel parameter results at CR 16:1 and for the random errors at CR 10:1 and 16:1. The variable inter-compression analysis presented systematic and random errors in the calibration factor and recalculated parameter results at CR 10:1 and 16:1. Any negative effect at CR 6:1 was found only for the calibration factor of the variable inter-compression analysis, which did not show up in the final vessel measurements. CONCLUSIONS: Compression ratios of 10:1 and 16:1 affected the QCA results negatively and therefore should not be used in clinical research studies. (+info)
American College of Cardiology/ European Society of Cardiology international study of angiographic data compression phase III. Measurement Of image quality differences at varying levels of data compression.
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OBJECTIVES: We sought to investigate up to which level of Joint Photographic Experts Group (JPEG) data compression the perceived image quality and the detection of diagnostic features remain equivalent to the quality and detectability found in uncompressed coronary angiograms. BACKGROUND: Digital coronary angiograms represent an enormous amount of data and therefore require costly computerized communication and archiving systems. Earlier studies on the viability of medical image compression were not fully conclusive. METHODS: Twenty-one raters evaluated sets of 91 cine runs. Uncompressed and compressed versions of the images were presented side by side on one monitor, and image quality differences were assessed on a scale featuring six scores. In addition, the raters had to detect pre-defined clinical features. Compression ratios (CR) were 6:1, 10:1 and 16:1. Statistical evaluation was based on descriptive statistics and on the equivalence t -test. Results At the lowest CR (CR 6:1), there was already a small (15%) increase in assigning the aesthetic quality score indicating "quality difference is barely discernible-the images are equivalent.' At CR 10:1 and CR 16:1, close to 10% and 55%, respectively, of the compressed images were rated to be "clearly degraded, but still adequate for clinical use' or worse. Concerning diagnostic features, at CR 10:1 and CR 16:1 the error rate was 9.6% and 13.1%, respectively, compared with 9% for the baseline error rate in uncompressed images. CONCLUSIONS: Compression at CR 6:1 provides equivalence with the original cine runs. If CR 16:1 were used, one would have to tolerate a significant increase in the diagnostic error rate over the baseline error rate. At CR 10:1, intermediate results were obtained. (+info)
Past presidents I have known.
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This paper is an account of the accomplishments of some of the early past presidents of the Medical Library Association known personally to the author in his career as a medical librarian. It demonstrates the qualities that made these librarians leaders of our profession and also indicates their personal attributes that contributed to the advancement of medical librarianship. It is hoped that the historical presentation of some of the giants of our profession will inspire present and future presidents and other medical librarians with an understanding of some of the qualities necessary to the continuing success of our profession. (+info)
Why some Jehovah's Witnesses accept blood and conscientiously reject official Watchtower Society blood policy.
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In their responses to Dr Osamu Muramoto (hereafter Muramoto) Watchtower Society (hereafter WTS) spokesmen David Malyon and Donald Ridley (hereafter Malyon and Ridley), deny many of the criticisms levelled against the WTS by Muramoto. In this paper I argue as a Jehovah's Witness (hereafter JW) and on behalf of the members of AJWRB that there is no biblical basis for the WTS's partial ban on blood and that this dissenting theological view should be made clear to all JW patients who reject blood on religious grounds. Such patients should be guaranteed confidentiality should they accept whole blood or components that are banned by the WTS. I argue against Malyon's and Ridley's claim that WTS policy allows freedom of conscience to individual JWs and that it is non-coercive and non-punitive in dealing with conscientious dissent and I challenge the notion that there is monolithic support of the WTS blood policy among those who identify themselves as JWs and carry the WTS "advance directive". (+info)
Medical confidentiality and the protection of Jehovah's Witnesses' autonomous refusal of blood.
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Mr Ridley of the Watch Tower Society (WTS), the controlling religious organisation of Jehovah's Witnesses (JWs), mischaracterises the issue of freedom and confidentiality in JWs' refusal of blood by confusing inconsistent organisational policies with actual Biblical proscriptions. Besides exaggeration and distortion of my writings, Ridley failed to present substantive evidence to support his assertion that no pressure exists to conform to organisational policy nor systematic monitoring which compromises medical confidentiality. In this refutation, I present proof from the WTS's literature, supported by personal testimonies of JWs, that the WTS enforces its policy of blood refusal by coercive pressure to conform and through systematic violation of medical confidentiality. Ridley's lack of candour in dealing with the plea of dissident JWs for freedom to make personal and conscientious decisions regarding blood indicates that a serious breach of ethics in the medical care of JWs continues. The medical community should be seriously concerned. (+info)
Use of a reference material proposed by the International Federation of Clinical Chemistry and Laboratory Medicine to evaluate analytical methods for the determination of plasma lipoprotein(a).
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BACKGROUND: As part of the NIH/National Heart, Lung and Blood Institute Contract for the Standardization of Lipoprotein(a) [Lp(a)] Measurements, a study was performed in collaboration with the IFCC Working Group for the Standardization of Lp(a) Assays. The aims of the study, performed with the participation of 16 manufacturers and 6 research laboratories, were to evaluate the IFCC proposed reference material (PRM) for its ability to transfer an accuracy-based value to the immunoassay calibrators and to assess concordance in results among different methods. METHODS: Two different purified Lp(a) preparations with protein mass concentrations determined by amino acid analysis were used to calibrate the reference method. A Lp(a) value of 107 nmol/L was assigned to PRM. After uniformity of calibration was demonstrated in the 22 evaluated systems, Lp(a) was measured on 30 fresh-frozen sera covering a wide range of Lp(a) values and apolipoprotein(a) [apo(a)] sizes. RESULTS: The among-laboratory CVs for these samples (6-31%) were, in general, higher than those obtained for PRM (2.8%) and the quality-control samples (14%, 12%, and 9%, respectively), reflecting the broad range of apo(a) sizes in the 30 samples and the sensitivity of most methods to apo(a) size heterogeneity. Thus, although all of the assays were uniformly calibrated through the use of PRM, no uniformity in results was achieved for the isoform-sensitive methods. CONCLUSIONS: Linear regression analyses indicated that to various degrees, apo(a) size heterogeneity affects the outcome of the immunochemical methods used to measure Lp(a). We have also shown that the inaccuracy of Lp(a) values determined by methods sensitive to apo(a) size significantly affects the assessment of individual risk status for coronary artery disease. (+info)