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At least 721 records · Page 40Linked to original sources
PubMed1994

KINI: a one compartment intravenous pharmacokinetic analysis program.

KINI is a microcomputer PC based software package which determines the one-compartment pharmacokinetic parameters for any drug using the Sawchuk-Zaske method. Through use of these programs, individualized pharmacokinetic analyses can be performed. The package allows for analysis of adult and pediatric patients, as well as offering a long and abbreviated data entry format. Additionally, KINI can generate a data file to be used with WordPerfect 5.0 or 5.1 to produce a consult for chart use.

Adult↗
PubMed1994

IS & C implementation of an image workstation.

The Image Save & Carry (IS & C) 5-inch magneto-optical disk system was introduced to a PACS image workstation so as to exchange digital image data between two independent PACS modules. The results showed that it was possible to connect two different PACS modules by off-line data transmission. Also, the IS & C standard software proved to be of high speed read/write performance for several data files on an image workstation. However, when the IS & C is implemented to the high resolution real-time digital radiography system, an image compression standard will be required to expand its capacity.

Animals↗
PubMed1992

A graphics program for the analysis and display of molecular dynamics trajectories.

The program SCARECROW has been developed to help the molecular modeler to analyze and display the very big and complex data files produced by molecular dynamics programs. The molecular graphics program SCARECROW is written to support the display, animation, and extensive analysis of molecular dynamics trajectories. Using the macro language it is easy to make scripts for video animation and for the automated display and analysis of time series. Extensive coloring and atom selection commands are included to help the user to focus on relevant regions of the molecule. Time series can be produced and viewed on the screen or transferred to other programs.

Chemical Phenomena↗
PubMed1991

Inequalities in health and health service use: evidence from the General Household Survey.

The General Household Survey data file for 1982 was examined to identify variations in self-reported morbidity and health service use between socio-economic groups and geographical areas in Great Britain. Both acute and chronic morbidity varied with socio-economic status. Morbidity was more strongly related to housing tenure and car availability than to occupational class. A north-west to south-east gradient in sickness was observed, although morbidity was comparatively high in Wales and comparatively low in Scotland, taking mortality differences into account. The highest age-adjusted morbidity ratios were for females in multiple occupancy inner city areas. Service use rates in relation to reported sickness showed little systematic variation. There was an indication that lack of car transport was an inhibiting factor for the sick in rural areas.

Adolescent↗
PubMed1989

Electron arc therapy: design, implementation and evaluation of a dynamic multi-vane collimator system.

Innovative techniques in motion control technology have been applied to the design and implementation of a portable computer-controlled multi-vane collimator for use in electron arc therapy. The collimator, consisting of 18 independently controlled vanes, is inserted into the standard accessory mount assembly of a linear accelerator, in the same fashion as standard field shaping blocks. Power is supplied to the collimator vane motors via a self-contained battery system. The range of motion of the vanes, symmetrically mounted nine on each side, provides a variable aperture width projected to isocenter of 2 cm minimum to 8 cm maximum. The projected length of the aperture at isocenter is 38 cm. The transition time between vane positions is less than 1 second, corresponding to gantry movement of less than 1 degree. The movement of each of the 18 vanes is monitored and controlled by six individually addressed three axis processors that are shielded from the electron beam. A table of collimator vane positions versus gantry angle, as determined by dose optimization calculations, is stored in a data file. The desired collimator vane position corresponding to the current arc segment is conveyed from the control console to each vane controller via packets within a token passing network. Communication between the computer in the console area and the vane controllers is accomplished through encoded infra-red pulse transmission, eliminating the need for additional communication lines between the console and the accelerator. This dynamic collimator offers improved dose uniformity while simplifying the delivery of electron arc therapy.

Electronics, Medical↗
PubMed1994

A multileaf collimator field prescription preparation system for conventional radiotherapy.

PURPOSE: The purpose of this work is to develop a prescription preparation system for efficient field shaping using a multileaf collimator that can be used in community settings as well as research institutions. The efficiency advantage of the computer-controlled multileaf collimator, over cerrobend blocks, to shape radiation fields has been shown in conformal treatments, which typically require complete volumetric computerized tomographic data for three-dimensional radiation treatment planning--a utility not readily available to the general community. As a result, most patients today are treated with conventional radiation therapy. Therefore, we believe that it is very important to fully use the same efficiency advantage of multileaf collimator as a block replacement in conventional practice. METHODS AND MATERIAL: The multileaf collimator prescription preparation systems developed by us acquires prescription images from different sources, including film scanner, and radiation treatment planning systems. The multileaf collimator angle and leaf positions are set from the desired field contour defined on the prescription image, by minimizing the area discrepancies. Interactive graphical tools include manual adjustment of collimator angle and leaf positions, and definition of portions of the field edges that require maximal conformation. Data files of the final leaf positions are transferred to the multileaf collimator controller via a dedicated communication link. RESULTS: We have implemented the field prescription preparation system and a network model for integrating the multileaf collimator and other radiotherapy modalities for routine treatments. For routine plan evaluation, isodose contours measured with film in solid water phantom at prescription depth are overlaid on the prescription image. Preliminary study indicates that the efficiency advantage of the MLC over cerrobend blocks in conformal therapy also holds true for conventional treatments. CONCLUSION: Our model of computer-controlled prescription, evaluation, and treatment using multileaf collimators can be effectively implemented in both community settings and research institutions. The resultant increase in treatment efficiency and accuracy is now available for conventional radiotherapy.

Humans↗
PubMed1995

A multileaf collimator field prescription preparation system for conventional radiotherapy.

PURPOSE: The purpose of this work is to develop a prescription preparation system for efficient field shaping using a multileaf collimator that can be used in community settings as well as research institutions. The efficiency advantage of the computer-controlled multileaf collimator, over cerrobend blocks, to shape radiation fields has been shown in conformal treatments, which typically require complete volumetric computerized tomographic data for three-dimensional radiation treatment planning--a utility not readily available to the general community. As a result, most patients today are treated with conventional radiation therapy. Therefore, we believe that it is very important to fully use the same efficiency advantage of multileaf collimator as a block replacement in conventional practice. METHODS AND MATERIAL: The multileaf collimator prescription preparation system developed by us acquires prescription images from different sources, including film scanner and radiation treatment planning systems. The multileaf collimator angle and leaf positions are set from the desired field contour defined on the prescription image, by minimizing the area discrepancies. Interactive graphical tools include manual adjustment of collimator angle and leaf positions, and definition of portions of the field edges that require maximal conformation. Data files of the final leaf positions are transferred to the multileaf collimator controller via a dedicated communication link. RESULTS: We have implemented the field prescription preparation system and a network model for integrating the multileaf collimator and other radiotherapy modalities for routine treatments. For routine plan evaluation, isodose contours measured with film in solid water phantom at prescription depth are overlaid on the prescription image. Preliminary study indicates that the efficiency advantage of the MLC over cerrobend blocks in conformal therapy also holds true for conventional treatments. CONCLUSION: Our model of computer-controlled prescription, evaluation, and treatment using multileaf collimators can be effectively implemented in both community settings and research institutions. The resultant increase in treatment efficiency and accuracy is now available for conventional radiotherapy.

Equipment Design↗
PubMedDate not supplied

A six-digit code for computer-aided dental identification.

A six-digit code for dental description is presented. It is intended to simplify the establishment of ante- and postmortem data files in a computer and consists of two digits for designating the individual tooth, two digits for describing the surface or surface combination involved (if any), and two digits for describing treatment type and material. Depending upon the number of teeth present, the dental description of one person may thus comprise from 1 to 32 six-digit numbers, ante- or post-mortem. The comparison by the computer of one antemortem with one postmortem set of numbers is a simple procedure.

Computers↗
PubMedDate not supplied

Implementation and evaluation of data compression of MR images.

A full-frame bit-allocation technique of data compression has been implemented using the existing computer facilities of an MR imager. Images reconstructed from compressed data files have been compared with the original image and changes in noise and pixel value measured to evaluate any image degradation introduced by the compression process. A 256 x 256 x 8 bit brain image can be compressed in 20 seconds with a compression ratio of greater than 4:1 without significant loss of information.

Head↗
PubMed1989

The craniofacial morphology in persons with maxillonasal dysplasia (Binder syndrome). A longitudinal cephalometric study of orthodontically treated children.

The aim of this investigation was to study the influence of orthodontic treatment on facial growth in subjects with maxillonasal dysplasia. The subjects were followed longitudinally from early childhood until growth was completed or almost completed. Fifteen patients, 9 boys and 6 girls, were orthodontically treated by conventional methods. They were compared with (1) another longitudinal group consisting of 13 orthodontically untreated children, 7 boys and 6 girls with the same syndrome, and (2) with a control material taken from computer-filed data on Swedish children and young adults with orthognatic profiles and normal occlusion. The orthodontic treatment led to acceptable dental conditions in 10 of the patients. No influence on craniofacial growth could be demonstrated. However, the mean facial polygons of the children showed that certain differences already existed at early ages between the treated subjects with a generally more severe form of the syndrome and the untreated children. The growth pattern seemed, however, to follow about the same rate in both groups. In six patients the orthodontic treatment was followed by surgical correction at adult age to solve their craniofacial problems. The optimum care of these patients requires an interdisciplinary treatment approach with thorough treatment planning by orthodontists in collaboration with oral and plastic surgeons.

Cephalometry↗
PubMed2006

Crash costs in the United States by crash geometry.

MAIN OBJECTIVES: This study was conducted to estimate the costs per crash for three police-coded crash severity groupings within 16 selected crash geometry types and within two speed limit categories ( or=50 mph). METHODS: We merged previously developed costs per victim by abbreviated injury scale (AIS) score into U.S. crash data files that scored injuries in both the AIS and police-coded severity scales to estimate injury costs, then aggregated the estimates into costs per crash by maximum injury severity. RESULTS: The most costly crashes were non-intersection fatal/disabling injury crashes on a road with a speed limit of 50 miles per hour or higher where multiple vehicles crashed head-on or a single vehicle struck a human (over 1.69 US dollars and 1.16 million US dollars per crash, respectively). The annual cost of police-reported run-off-road collisions, which include both rollovers and object impacts, represented 34% of total costs. CONCLUSIONS: This paper provides cost estimates useful for evaluating roadway countermeasures and for designing vehicles to minimize crash harm. It gives unit costs of crashes by type in the coding system used by the police. The costs are in an appropriate form for economic analysis of countermeasures addressing locally defined problems identified by analyzing police crash reports.

Abbreviated Injury Scale↗
PubMed2006

Effects on accidents of periodic motor vehicle inspection in Norway.

An extensive programme of periodic motor vehicle inspection was introduced in Norway after 1995, when the treaty between Norway and the European Union (EU) granting Norway (not a member of the EU) access to the EU inner market took effect (The EEA treaty). This paper evaluates the effects on accidents of periodic inspections of cars. Trucks and buses were not included in the study. Negative binomial regression models were fitted to data on accidents and inspections created by merging data files provided by a major insurance company and by the Public Roads Administration. Technical defects prior to inspection were associated with an increased accident rate. Inspections were found to strongly reduce the number of technical defects in cars. Despite this, no effect of inspections on accident rate were found. This finding is inconsistent with the fact that technical defects appear to increase the accident rate; one would expect the repair of such defects to reduce the accident rate. Potential explanations of the findings in terms of behavioural adaptation among car owners are discussed. It is suggested that car owners adapt driving behaviour to the technical condition of the car and that the effect attributed to technical defects before inspection may in part be the result of a tendency for owners who are less concerned about safety to neglect the technical condition of their cars. These car owners might have had a higher accident rate than other car owners irrespective of the technical condition of the car.

Accidents, Traffic↗
PubMed2006

Pathways between ecstasy initiation and other drug use.

This study aims to shed light on drug use pathways associated with ecstasy use initiation. Data from 54,573 respondents aged 12-21 years old from the 2002-2003 National Survey on Drug Use and Health (NSDUH) public use data files were analyzed via Cox proportional hazards models with time-dependent covariates. Our findings showed that marijuana, cocaine, and heroin were significant independent predictors of subsequent ecstasy use. Earlier ecstasy initiation was significantly associated with subsequent other illegal drug initiation (marijuana, cocaine and heroin). The strength of the association was greater for the pathway from earlier marijuana initiation to subsequent ecstasy initiation as compared to the pathway in the opposite direction. The pathway from earlier ecstasy initiation to subsequent cocaine and heroin initiation was also stronger as compared to pathways in the opposite directions. Pathways between ecstasy initiation and marijuana, cocaine and heroin initiation seem to be independent of the association between drug use and psychiatric symptoms/deviant behaviors. Ecstasy initiation seems to play a role in the subsequent initiation of cocaine and heroin.

Adolescent↗
PubMed2005

Mode of delivery and risk of stillbirth and infant mortality in triplet gestations: United States, 1995 through 1998.

OBJECTIVE: The purpose of this study was to estimate the risks of stillbirth and neonatal and infant deaths in triplets, according to mode of delivery. STUDY DESIGN: We used the "matched multiple birth" data file that was comprised of triple births that were delivered in the United States in the years 1995 through 1998. Analyses were restricted to fetuses that were delivered at >/=24 weeks of gestation. Based on the order of the birth of the fetuses within the triplet set, the mode of delivery of triplets was assigned as cesarean-cesarean-cesarean (all cesarean), vaginal-vaginal-vaginal (all vaginal), and vaginal-cesarean-cesarean or vaginal-vaginal-cesarean (other). Associations between mode of delivery and stillbirth, neonatal deaths (within 28 days), and infant deaths (up to 1 year) were expressed as relative risks with 95% confidence intervals and population attributable risks, which were derived from multivariate logistic regression models that were based on the method of generalized estimated equations (with all cesarean deliveries serving as the reference). All analyses were adjusted for several confounding factors. RESULTS: Ninety-five percent of all triplets were delivered by cesarean delivery. Vaginal delivery (all vaginal) was associated with an increased risk for stillbirth (relative risk, 5.70; 95% CI, 3.83, 8.49) and neonatal (relative risk, 2.83; 95% CI, 1.91, 4.19) and infant (relative risk, 2.29; 95% CI, 1.61, 3.25) deaths. The population-attributable risks were 15.9% for neonatal and 12.4% for infant deaths, which implied that these proportions of deaths were potentially avoidable had these triplet fetuses all been delivered by cesarean delivery rather than all fetuses being delivered vaginally. CONCLUSION: Cesarean delivery of all 3 triplet fetuses is associated with the lowest neonatal and infant mortality rate. Vaginal delivery among triplet gestations should be avoided.

Cesarean Section↗
PubMed2006

Temporal changes in rates of stillbirth, neonatal and infant mortality among triplet gestations in the United States.

OBJECTIVE: The purpose of this study was to examine temporal changes in stillbirth, neonatal and infant mortality rates among triplet births in the US, and to assess the contributions of triplet delivery at < 34 weeks to these changes. STUDY DESIGN: Data on triplet live births, and fetal and infant deaths (1990-2002) delivered at > or = 22 weeks and fetuses weighing > or = 500 g (n = 66,986) were derived from the US linked birth/infant death data files. Relative risk (RR), quantifying changes in triplet stillbirth, neonatal (death within the first 28 days) and infant mortality (death within the first year) rates between 1990 and 1991 and 2001 and 2002, were derived. Temporal changes in triplet births at < 34 weeks, and changes in stillbirth, and neonatal and infant mortality rates were examined through logistic regression models before and after adjusting for confounders. RESULTS: Triplet births at < 34 weeks increased by 25% between 1990 and 1991 (48.7%) and 2001 and 2002 (60.9%). Stillbirth, neonatal and infant mortality rates declined by 52% (RR 0.48, 95% confidence interval [CI] 0.36-0.63), 32% (RR 0.68, 95% CI 0.58-0.80), and 38% (RR 0.62, 95% CI 0.53-0.71), respectively, between 1990 and 1991 and 2001 and 2002. The increase in triplet births at < 34 weeks was not associated with the stillbirth decline, but was associated with an excess 14% and 12% increase in neonatal and infant deaths, respectively. CONCLUSION: Our findings suggest that the increase in triplet births at < 34 weeks' gestation is not associated with changes in triplet stillbirths, but is associated with increases in triplet neonatal and infant mortality.

Female↗
PubMed2004

Changes in weight among a nationally representative cohort of adults aged 51 to 61, 1992 to 2000.

BACKGROUND: Few studies have examined patterns and predictors of changes in body weight among adults in late middle age. METHODS: Prospective cohort study of 7391 community-dwelling U.S. adults aged 51 to 61 years at baseline (1992), using publicly available data files from the 1992, 1994, 1996, 1998, and 2000 Health and Retirement Survey interviews. Changes in weight and body mass index (BMI) were examined for different racial/ethnic groups of men and women. The predictors of changes in body weight and BMI were determined using gender-specific linear regression. RESULTS: Mean body weight and BMI increased in both genders and all ethnic groups. The mean weight gain was higher for women (1.67 kg, 95% confidence interval [CI]=1.34-1.99) than for men (1.43 kg, 95% CI=1.17-1.68). White men and women had the lowest baseline BMI but tended to gain more weight than other racial/ethnic groups. In multivariate analyses, individuals who were older or had higher baseline weight showed less weight gain. Men were less likely to gain weight if their self-reported overall health at baseline was poor compared to those in excellent health. Regular light or vigorous recreational activities and work-related activities were not associated with less weight gain. Race, education, and income were not associated with weight gain in multivariate analyses. CONCLUSIONS: All population subgroups are at risk for weight gain. Public health messages should target diverse populations. The current levels of physical activity attained by this population do not appear to protect against weight gain.

Body Mass Index↗
PubMed2005

Regression models for clustered binary responses: implications of ignoring the intracluster correlation in an analysis of perinatal mortality in twin gestations.

PURPOSE: Dependent binary responses, such as health outcomes in twin pairs or siblings, frequently arise in perinatal epidemiologic research. This gives rise to correlated data, which must be taken into account during analysis to avoid erroneous statistical and biological inferences. METHODS: An analysis of perinatal mortality (fetal deaths plus deaths within the first 28 days) in twins in relation to cluster-varying (those that are unique to each fetus within a twin pregnancy such as birthweight) and cluster-constant (those that are identical for both twins within a sibship such as maternal smoking status) risk factors is presented. Marginal (ordinary logistic regression [OLR] and logistic regression using generalized estimating equations [GEE]) and cluster-specific (conditional and random-intercept logistic regression models) regression models are fit and their results contrasted. The United States "matched multiple data" file of twin births (1995-1997), which includes 285,226 twins from 142,613 pregnancies, was used to examine the implications of ignoring of clustering on regression inferences. RESULTS: The OLR models provide variance estimates for cluster constant covariates that ranged from 7% to 71% smaller than those from GEE-based models. This underestimation is even more pronounced for some cluster-varying covariates, ranging from 21% to 198%. CONCLUSIONS: Ignoring the cluster dependency is likely to affect the precision of covariate effects and consequently interpretation of results. With widespread availability of appropriate software, statistical methods for taking the intracluster dependency into account are easily implemented and necessary.

Cluster Analysis↗
PubMed2006

Paediatric burns in Kuwait: incidence, causes and mortality.

From a prospective study on burn patients admitted at the Burn Center in Kuwait during 1993-2001, 826 paediatric burn cases, in 0-14 years age group, were retrieved to study incidence, causes, and mortality among children. The demographic characteristics, clinical features, and outcome constituted our data file in Statistical Software, SPSS. Overall incidence rate was 17.5/100,000 children aged 0-14 years, being almost twice (34/100,000) among those between 0 and 4 years, constituting 70.8% of all paediatric burns. Scald was the main cause of burn (67%), followed by flame (23%). Mean age (6.4 years) of children with flame burns, was significantly higher (p < 0.001) than those with scalds, or other causes. A positive significant correlation existed between duration of hospital stay and TBSA% (r = 0.56, p < 0.001). Overall mortality rate was 0.23/100,000 children, maximum (0.52/100,000) being in children below 5 years. Among 11 (1.3%) non-survivors, flame burns caused nine fatalities. Multiple logistic regression mooring predicted children aged < 5 years, flame burns and TBSA >or= 70%, (OR = 29.2, p < 0.001), as main contributing factors to fatal outcome among children. Gender and nationality had no influence on incidence or mortality. These findings will hopefully stimulate development of targeted and sustainable interventions for reducing burns occurrence among identified paediatric high-risk groups.

Adolescent↗