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Selective automated indexing of findings and diagnoses in radiology reports.

The recent improvements in capabilities of desktop computers and communications networks give impetus for the development of clinical image repositories that can be used for patient care and medical education. A challenge in the use of these systems is the accurate indexing of images for retrieval performance acceptable to users. This paper describes a series of experiments aiming to adapt the SAPHIRE system, which matches text to concepts in the UMLS Metathesaurus, for the automated indexing of image reports. A series of enhancements to the baseline system resulted in a recall of 63% but a precision of only 30% in detecting concepts. At this level of performance, such a system might be problematic for users in a purely automated indexing environment. However, if the ability to retrieve images in repositories based on content in their reports is desired by clinical users, and no other current systems offer this functionality, then follow-up research questions include whether these imperfect results would be useful in a completely or partially automated indexing environment and/or whether other approaches can improve upon them.

Abstracting and Indexing↗

The MEDLINE experience at Yale: 1986-1996.

The Cushing/Whitney Medical Library began providing end-user access to MEDLINE in 1986 and switched to the OVID system in 1993. MEDLINE is a core service of the library, and the choice of delivery systems has had a significant impact throughout the Yale-New Haven Medical Center. This paper describes the user response to MEDLINE, discusses the effects of MEDLINE on other library services, and suggests ways in which technology, policy, and funding have influenced use. Yale's experience suggests that removing barriers in all three areas can dramatically expand the points of access, the number of users, and the amount of use with manageable effects on other library services.

Academic Medical Centers↗

The time course of hearing aid benefit.

OBJECTIVE: The present study sought to determine whether benefit derived from hearing aid use increases with hearing aid experience. This question is of considerable interest to both researchers and clinicians. Several previous investigations recently published have obtained mixed results. DESIGN: Control conditions were provided to address the potential influences of practice effects and changes in preferred hearing aid gain. The experimental group consisted of 13 hearing-impaired listeners about to be fit with their first hearing-aid. The control group consisted of 13 hearing aid users with at least 1 yr's experience with their hearing aids. The control group permitted examination of practice effects that may have confounded previous results showing increases in benefit with experience. Hearing aid benefit was defined as aided speech recognition ability minus unaided speech recognition ability and was assessed repeatedly over 18 wk. Two measures of hearing aid benefit were employed: an objective syllable recognition task and a subjective questionnaire. For the objective measure, hearing aid benefit was assessed for the condition of fixed hearing aid gain and also for the condition of subject-adjusted hearing aid gain to examine effects of changes in audibility that may have influenced benefit and confounded previous results. RESULTS: The objective measure of group mean hearing aid benefit increased significantly over time for both gain conditions for the new hearing aid users, but did not increase for the long-standing control group. Subjective benefit increased over time, but without statistical significance for the new hearing aid users, and was essentially unchanged for the long-standing control group. CONCLUSIONS: Results suggest that the observed improvements in speech recognition are not due to increases in audibility nor to simple practice effects. The overall improvements in benefit over time were of statistical significance and also practical importance for studies of group differences. However, the improvements are too small to be observed consistently for individual hearing aid users.

Aged↗

The mind over the Web: the quest for the definition of a method for Internet research.

Psychology is increasingly interested in understanding the characteristics of the Internet and its effects on people, groups and organizations. However, studying the Internet is not a simple task. First, the Internet is a medium that can be experienced in many different ways. Though a computer and keyboard are usually the mediator of our Internet experience, there are different ways in which users can explore the Internet, present themselves, and communicate using it. Second, the Internet is a social and cognitive space. The handling of information is linked to the activation of psychosocial relationships in which cognitions are elaborated. This happens inside a rather special kind of container--Cyberspace--which tends to rarefy the structural and process features of communication. Third, the Internet experience is always situated in a specific context, even when we are chatting alone in a room. In this sense it can only be fully understood through detailed analysis of the social context in which it happens. Starting from a general three-level model of interpersonal interaction in the Web, this paper tries to define a model of data analysis (Complementary Explorative Multilevel Data Analysis--CEMDA) suited to the constraints of Internet research. The main characteristics of the model are: the focus on different frames and objects for each considered unit of research; the mixed use of quantitative and qualitative tools; and the final integration of results in a general framework.

Cognition↗

Effect of oral contraceptives on the renin angiotensin system and renal function.

We examined the effect of oral contraceptive (OC) usage on the renin angiotensin system (RAS) in two related experiments. In the first experiment, subjects were 34 healthy, normotensive, premenopausal women, 15 OC users and 19 OC nonusers, mean age 25 +/- 1 yr, ingesting a controlled sodium diet. We assessed arterial pressure, glomerular filtration rate, effective renal plasma flow, renal vascular resistance (RVR), and filtration fraction (FF) using inulin and p-aminohippurate clearance techniques, both at baseline and in response to the ANG II receptor blocker losartan. In the second experiment, in similar subjects, 10 OC users and 10 nonusers, we examined circulating RAS components [angiotensinogen, ANG II, aldosterone, plasma renin activity (PRA), and active renin] in response to incremental lower body negative pressure (LBNP), to determine whether renin secretion is suppressed by OC usage. OC users exhibited elevations in systolic blood pressure, RVR, and FF compared with nonusers, which were partially corrected by losartan. In the LBNP phase of the study, baseline measures of PRA, angiotensinogen, ANG II, and aldosterone were all increased in the OC group compared with the control group. Active renin levels did not differ between groups. Incremental LBNP resulted in increased circulating levels of RAS components in both groups. We conclude that the RAS is activated in women using OCs. There was no evidence that decreases in renin secretion result in normalization of the RAS as a whole.

Adult↗

Direct comparison of time to AIDS and infectious disease death between HIV seroconverter injection drug users in Italy and the United States: results from the ALIVE and ISS studies. AIDS Link to Intravenous Experiences. Italian Seroconversion Study.

OBJECTIVE: To compare the rate of HIV disease progression in a sample of polydrug injectors (AIDS Link to Intravenous Experiences [ALIVE] study) with that in a sample of predominantly opiate injectors (Italian Seroconversion Study [ISS]). DESIGN: Prospective cohort studies of HIV-positive individuals whose date of seroconversion (SC) is known with a good degree of precision. The ALIVE study involves a community-based cohort of injection drug users (IDU) in the United States and the ISS reports on a clinic-based cohort of seroconverters in Italy with different exposure modalities to HIV. METHODS: Data from the two cohorts were combined. The date of SC was estimated as the midpoint in time between the last negative and the first positive HIV test. Time-to-event (i.e., AIDS or death from an infectious disease) statistical methods were used. Relative hazards (RH) of progression to event were adjusted by age at SC, gender, and year of SC. RESULTS: Of the 1003 IDUs (251 from ALIVE and 752 from ISS), 226 progressed to AIDS, and 146 died after AIDS or from an infectious disease; of these, 10 were without an AIDS diagnosis. The two groups of IDUs differed in terms of age at SC (median, 35 years for ALIVE and 25 years for ISS), proportion of women (24% versus 31%), race (7.6% versus 100% white), and year of seroconversion (i.e., ISS participants seroconverted, on average, earlier than ALIVE participants). Although the univariate analysis suggested possible differences for progression to AIDS, or to death from infectious disease between cohorts, multivariate analyses that adjusted for age showed no significant differences by cohort, gender, race, or time of seroconversion. The median time to AIDS for 25-year-old persons was 12.3 years for ALIVE and 11.8 years for ISS; for 35-year-old persons, it was 8.5 and 8.2 years, respectively. These estimates were similar to those for non-IDUs observed in the ISS and to those from large cohort of homosexual men. CONCLUSION: Our results confirm the importance of accounting for age when considering the incubation period for HIV infection. Despite differences in drug use characteristics, the similar median times to AIDS, for each age, between the two cohorts of IDUs and between the IDUs and the non-IDUs suggest a negligible effect of injection drug use on HIV progression.

Acquired Immunodeficiency Syndrome↗

Overdoses among cocaine users in Brazil.

AIMS: A survey of cocaine users was undertaken to study (i) the frequency of reported drug overdoses among cocaine users; and (ii) the frequency of witnessing drug overdoses in the same population. DESIGN AND SETTING: A cross-sectional study as part of the World Health Organization (WHO) Multi-city Study among injecting drug users (IDUs), phase II, was conducted in Santos Metropolitan Region, State of São Paulo, Brazil, in 1999. PARTICIPANTS: Three hundred and ninety-six exclusive users of cocaine in the Santos Metropolitan Region, São Paulo State, Brazil were surveyed concerning their past experience with drug overdoses. FINDINGS: Eighty (20%) of the cocaine users reported having experienced one or more overdoses, and 50% reported that they knew one or more other cocaine users who had died of an overdose. On multivariate analysis, being female and having spent time in jail were associated with an increased likelihood of having had one or more overdoses. CONCLUSION: Cocaine overdoses are an important and under-recognized health problem in the Santos Metropolitan Region, and possibly in other areas of Brazil.

Adolescent↗

Development of quantitative reverse transcriptase PCR assays for measuring gene expression.

Real-time, quantitative reverse transcriptase (RT)-PCR is a very useful and powerful technology for analysis of gene expression. At a first pass, real-time PCR appears to be a simple extension of regular PCR, and it should therefore be easy for an experienced PCR user to convert to quantitative assays. In practice, however, our experience would indicate that this is not usually the case, and most novice real-time PCR users run into problems even though they are very capable at regular PCR. One problem is that, unlike Northern blots, which are technically difficult but typically either work or do not, real-time PCR assays, even poorly designed ones, usually give data. Unfortunately, these data, or their interpretation, may be erroneous, since there are many potential pitfalls that need to be avoided when designing and using real-time PCR for measurement of gene expression. The purpose of this chapter is not to try to discuss the complexities of real-time PCR in detail (which would require a whole book), but, instead, to provide a simple outline for the development of real-time PCR assays. If followed, these guidelines should allow the reader to develop real-time PCR assays that avoid the most common pitfalls and that are capable of producing reliable and accurate gene expression data.

Animals↗

Characteristics of condom use and associated problems: experience in Bangladesh.

Data from the 1983 Bangladesh Condom User Survey (BCUS) are analyzed for patterns of condom use and various problems directly influencing their effectiveness. The survey was undertaken to explain an apparent gap between reports of the number of condoms distributed in certain areas compared with prevalence of users as reported in contraceptive prevalence surveys. These data are analyzed from behavioral and management perspectives to identify various factors influencing utilization, with potential implications for understanding and improving family planning and AIDS/STD prevention service systems. Patterns of use are related to differences in source of supply through public, free or private-priced systems, differences in urban or semi-rural place of residence, and differences in perceptions of men or women. The problem with condom use most often identified by the respondents was breakage.

Adult↗

Teaching cancer chemotherapy by means of a computer simulation.

BIO-1014 is an educational computer-based program written in TURBO PASCAL 3.01 which simulates experiments of antitumour activity. Basically, this program offers the user the possibility of checking the therapeutical efficiency of anticancer drugs as applied to different tumors, but many other types of experiment can be also performed with BIO-1014. Drugs such as methotrexate, cyclophosphamide and arabinosylcytosine can be tested on the following tumors: sarcoma, carcinoma, leukemia and melanoma. The dose, the number of treatments per day, the total number of treatments and the time interval between the treatments are the parameters to be adjusted for each therapeutical schedule. Tumoral growth, cause of death and survival are among the results that are generated after each simulation. These results are either tabulated or plotted. In addition, four statistical tests have also been integrated to the program in order to provide with a way to check whether or not there is a significant difference in terms of survival between two groups of mice differently treated. Furthermore, the program has been elaborated to also consider some physiological phenomena met within an anticancer drug screening programme. The potential and the performance of the program BIO-1014 is presented and discussed.

Animals↗

Reduced duration of intrathecal sufentanil analgesia in laboring cocaine users.

UNLABELLED: On the basis of our previous clinical experience, we hypothesized in this study that the duration and/or quality of labor analgesia produced by intrathecal sufentanil was less in cocaine-abusing parturients compared with nonabusing parturients. Ten micro g of sufentanil was given intrathecally as part of a combined spinal-epidural (CSE) technique to two groups of laboring parturients: 1). those whose urine tested positive for cocaine (cocaine group), and 2). those whose urine tested negative for cocaine (control group). The epidural catheter was not injected with local anesthetic until the patient requested additional pain relief. The time from injection of intrathecal sufentanil until patient request for additional pain relief was defined as duration of analgesia. Baseline visual analog pain score (VAPS) and cervical dilation were measured before the CSE was performed. After injection of intrathecal sufentanil, VAPS was recorded at specific intervals. Cervical dilation was again documented when the patient requested additional analgesia. We found that both groups reported high baseline VAPS and a marked decrease in VAPS after injection of sufentanil that did not differ between groups. Geometric mean duration of pain relief with adjustment for cervical dilation was 87 min in the cocaine group compared with 139 min in the control group (P = 0.019). All patients experienced itching. We conclude that intrathecal sufentanil produces a similar quality but shorter duration of analgesia in cocaine-abusing parturients compared with nonabusing parturients. IMPLICATIONS: Intrathecal sufentanil administered as part of a combined spinal-epidural technique produces similar quality but reduced duration of labor analgesia in cocaine-abusing parturients compared with nonabusing parturients.

Adult↗

The wheelchair skills test (version 2.4): measurement properties.

OBJECTIVE: To evaluate the measurement properties of the Wheelchair Skills Test (WST), version 2.4. DESIGN: Cohort study. SETTING: Rehabilitation center. PARTICIPANTS: A total of 298 subjects (169 wheelchair users, 129 able-bodied subjects) ranging in age from 17 to 88 years. INTERVENTION: We videotaped subjects as they attempted the 50 skills of the WST 2.4. MAIN OUTCOME MEASURES: The test-retest, intrarater, and interrater reliabilities were determined on a subset of 20 wheelchair users. We assessed construct validity by evaluating whether the WST detected expected changes and concurrent validity by seeing how well total WST scores correlated with criterion measures. RESULTS: The mean time +/- standard deviation taken to administer the WST was 27.0+/-9.3 minutes. There were no serious adverse incidents, and the test was well tolerated. For the test-retest, intrarater and interrater reliabilities, the intraclass correlation coefficients for the total scores were.904,.959, and.968. For individual skills, the percentage concordance ranged from 73% to 100%. Regarding construct validity, there was a slightly negative Pearson correlation between total WST score and age (-.434). Gender was identified as a significant factor on multiple regression analysis (P<.001). Wheelchair users with more than 21 days of experience scored higher than those with less experience (65.0% vs 59.6%; P=.01). Participants with stroke and related disorders had a mean score (55.0%+/-13.9%) that was significantly lower than those in other diagnostic categories (P<.05). Participants using conventional wheelchairs had lower scores than those in lightweight ones (66.4% vs 75.1%; P<.001). Regarding concurrent validity, Spearman rank correlations between total WST scores and the global assessments of the wheelchair users' therapists and admission and discharge FIM instrument scores were.394,.38, and.31. CONCLUSIONS: The WST 2.4 is practical and safe, and its measurement properties are very good to excellent. Further study is needed to determine its usefulness in various clinical settings.

Adolescent↗

A comparison of injection and non-injection methamphetamine-using HIV positive men who have sex with men.

There is a paucity of research on the psychosocial and behavioral characteristics of individuals who inject methamphetamine (meth). The present study compared injection and non-injection users of meth in terms of background characteristics, drug use patterns, health and social problems, sexual risk behavior, and psychosocial factors. The sample consisted of 194 HIV+Men who have Sex with Men (MSM) who were enrolled in a sexual risk reduction intervention for meth users. Men who injected meth were significantly more likely to be Caucasian, bisexual, homeless, divorced/separated, with lower educational attainment as compared to non-injectors. Injectors also reported more years of meth use, greater frequency and amount of meth use, more social and health problems, including higher prevalence of STDs and Hepatitis C, and more sexual risk behaviors. In terms of psychosocial factors, injection users of meth scored significantly higher on measures of impulsivity and experiences of rejection, and lower on a measure of emotional support. A multivariate logistic regression revealed that educational attainment and experiences of rejection were the factors that best discriminated between injection and non-injection users of meth. The unique characteristics of injection meth users are discussed in relation to the development of effective HIV prevention programs for the target population.

Adult↗

Multidimensional data visualization.

Historically, data visualization has been limited primarily to two dimensions (e.g., histograms or scatter plots). Available software packages (e.g., Data Desk 6.1, MatLab 6.1, SAS-JMP 4.04, SPSS 10.0) are capable of producing three-dimensional scatter plots with (varying degrees of) user interactivity. We constructed our own data visualization application with the Visualization Toolkit (Schroeder, Martin, & Lorensen, 1998) and Tcl/Tk to display multivariate data through the application of glyphs (Ware, 2000). A glyph is a visual object onto which many data parameters may be mapped, each with a different visual attribute (e.g., size or color). We used our Multi-Dimensional data Viewer to explore data from several psycholinguistic experiments. The graphical interface provides flexibility when users dynamically explore the multidimensional image rendered from raw experimental data. We highlight advantages of multidimensional data visualization and consider some potential limitations.

Data Display↗

MiMiR: a comprehensive solution for storage, annotation and exchange of microarray data.

BACKGROUND: The generation of large amounts of microarray data presents challenges for data collection, annotation, exchange and analysis. Although there are now widely accepted formats, minimum standards for data content and ontologies for microarray data, only a few groups are using them together to build and populate large-scale databases. Structured environments for data management are crucial for making full use of these data. DESCRIPTION: The MiMiR database provides a comprehensive infrastructure for microarray data annotation, storage and exchange and is based on the MAGE format. MiMiR is MIAME-supportive, customised for use with data generated on the Affymetrix platform and includes a tool for data annotation using ontologies. Detailed information on the experiment, methods, reagents and signal intensity data can be captured in a systematic format. Reports screens permit the user to query the database, to view annotation on individual experiments and provide summary statistics. MiMiR has tools for automatic upload of the data from the microarray scanner and export to databases using MAGE-ML. CONCLUSION: MiMiR facilitates microarray data management, annotation and exchange, in line with international guidelines. The database is valuable for underpinning research activities and promotes a systematic approach to data handling. Copies of MiMiR are freely available to academic groups under licence.

Data Collection↗

Breakage and slippage of condoms among users in north Gondar Province, Ethiopia.

OBJECTIVE: To determine the frequency of condom breakage and slippage among male condom users and to analyse some factors affecting condom breakage. DESIGN: Prospective study undertaken from March to June 1996. SETTING: Gondar, Teda and Aykel health centres in north Gondar province. PARTICIPANTS: One hundred and seventy literate male condom users who volunteered to participate in the study were enrolled, but data were collected and analysed for 143 persons. MAIN OUTCOME MEASURES: Condom breakage was measured as the number of condom broken while opening the package, putting on, during intercourse or withdrawal; and condom slippage was measured as the number of condoms slipped off the penis during intercourse or withdrawal. RESULTS: Of 143 participants, 26.6% broke condoms. Total condom breakage rate was 4.6% and slippage rate was 0.1%; half of the condom breakage occurred at the tip. Condom breakage was more observed in less educated (p < 0.05). Breakage rate and experience of condom use were negatively correlated (r = -0.214, P < 0.05). CONCLUSION: User's knowledge and experience reduce the breakage of condom.

Adolescent↗

Visualization and analysis of microarray and gene ontology data with treemaps.

BACKGROUND: The increasing complexity of genomic data presents several challenges for biologists. Limited computer monitor views of data complexity and the dynamic nature of data in the midst of discovery increase the challenge of integrating experimental results with information resources. The use of Gene Ontology enables researchers to summarize results of quantitative analyses in this framework, but the limitations of typical browser presentation restrict data access. RESULTS: Here we describe extensions to the treemap design to visualize and query genome data. Treemaps are a space-filling visualization technique for hierarchical structures that show attributes of leaf nodes by size and color-coding. Treemaps enable users to rapidly compare sizes of nodes and sub-trees, and we use Gene Ontology categories, levels of RNA, and other quantitative attributes of DNA microarray experiments as examples. Our implementation of treemaps, Treemap 4.0, allows user-defined filtering to focus on the data of greatest interest, and these queried files can be exported for secondary analyses. Links to model system web pages from Treemap 4.0 enable users access to details about specific genes without leaving the query platform. CONCLUSIONS: Treemaps allow users to view and query the data from an experiment on a single computer monitor screen. Treemap 4.0 can be used to visualize various genome data, and is particularly useful for revealing patterns and details within complex data sets.

Animals↗

Computer mouse operation: is the left-handed user disadvantaged?

A survey of University of Melbourne student-use computers showed that 100% had the mouse installed on the right-hand side. An experiment was performed to determine if the left-handed user was disadvantaged by this arrangement. Times to move the cursor to targets of different sizes and distances showed that left-handed users were not significantly disadvantaged and that, in accord with other tests, they were as good using their non-preferred hand as they were with their preferred hand. As expected, left-handers were superior to right-handed users when using their non-preferred hand.

Analysis of Variance↗