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[3D power Doppler ultrasound: new possibilities in the diagnosis and documentation of tumors of the base of the tongue].

BACKGROUND: To evaluate a novel 3-D power Doppler ultrasound technique (3-D PDUS) in the diagnosis and documentation of tumors of the base of the tongue. PATIENTS AND METHODS: Twenty patients with tumors of the base of the tongue (2T1, 6T2, 6T3, and 6T4 carcinomas) prospectively underwent two-dimensional gray scale and power Doppler ultrasound and 3-D PDUS (3-Scape). All examinations were performed with a 7.5 MHz transducer and the Sonoline Elegra Advanced. Two independent observers compared the examinations regarding clear tumor margins, maximal diameter of the tumor, midline crossing, infiltration of the mylohyoid muscle, infrahyoidal tumor, contact to the lingual artery, vascularization in the tumor and in surrounding tissue, and evaluated the documentary use of the 3-D reconstruction. RESULTS: All relevant pretreatment parameters were accessible in the 3-D data; results of both observers were almost identical. An acquisition and reconstruction of the 3-D data takes only a couple of minutes. In addition to two-dimensional ultrasound 3-D PDUS allows reconstruction of axial images of the base of the tongue similar to CT images and a 3-D visualization of tumor vascularization. CONCLUSIONS: 3-Scape is a novel user-friendly method that allows uninterrupted acquisition of large 3-D volumes, and digital storage and transmission of ultrasound studies without loss of information. US images can be reconstructed in any desired plane or visualized in 3-D. In the future, additional software will permit exact determination of the volume and degree of vascularization of tumors.

Adult↗

EON: a component-based approach to automation of protocol-directed therapy.

Provision of automated support for planning protocol-directed therapy requires a computer program to take as input clinical data stored in an electronic patient-record system and to generate as output recommendations for therapeutic interventions and laboratory testing that are defined by applicable protocols. This paper presents a synthesis of research carried out at Stanford University to model the therapy-planning task and to demonstrate a component-based architecture for building protocol-based decision-support systems. We have constructed general-purpose software components that (1) interpret abstract protocol specifications to construct appropriate patient-specific treatment plans; (2) infer from time-stamped patient data higher-level, interval-based, abstract concepts; (3) perform time-oriented queries on a time-oriented patient database; and (4) allow acquisition and maintenance of protocol knowledge in a manner that facilitates efficient processing both by humans and by computers. We have implemented these components in a computer system known as EON. Each of the components has been developed, evaluated, and reported independently. We have evaluated the integration of the components as a composite architecture by implementing T-HELPER, a computer-based patient-record system that uses EON to offer advice regarding the management of patients who are following clinical trial protocols for AIDS or HIV infection. A test of the reuse of the software components in a different clinical domain demonstrated rapid development of a prototype application to support protocol-based care of patients who have breast cancer.

Algorithms↗

Standardized, reproducible, high resolution global measurements of T1 relaxation metrics in cases of multiple sclerosis.

BACKGROUND AND PURPOSE: We herein present a methodology for standardized and clinically applicable measurement of T1 relaxation maps with high resolution and volumetric coverage by using the commercially available 3D spoiled gradient-echo sequence. The reproducibility of the T1 metrics derived from these maps and their sensitivity to distinguish between control participants and patients with multiple sclerosis are evaluated. METHODS: Axial view 3D RF spoiled data sets with two flip angles were acquired at 1.5 T to generate the T1 maps, with all other imaging parameters (27/6 ms [TR/TE]; field of view, 180 x 240 x 186 mm(3); matrix, 192 x 256 x 124) kept identical between the two acquisitions. T1 maps were collected from 20 normal control participants and 32 patients with multiple sclerosis. An automated and operator-independent method was developed to segment the relaxation maps and define T1 metrics. RESULTS: We showed that the metrics derived from these maps to represent tissue characteristics were highly reproducible (coefficient of variation, approximately 1% to 4%) and were significantly different between normal control participants and patients with multiple sclerosis (P <.001) for the small cohort of patients in this study. CONCLUSION: The commercially accessible 3D spoiled gradient-echo sequence can be used to generate T1 relaxation maps with high resolution and volumetric coverage. The metrics derived from the relaxation maps are reproducible and have been shown to be sensitive to qualitative and quantitative differences between subgroups of patients with multiple sclerosis and control participants, with strong statistical significance. The use of a commercially available sequence enables the standardization and comparison of T1 metrics across different multiple sclerosis centers.

Artifacts↗

Interventions for promoting booster seat use in four to eight year olds traveling in motor vehicles.

BACKGROUND: Public health and traffic safety agencies recommend use of booster seats in motor vehicles for children aged four to eight years, and various interventions have been implemented to increase their use by individuals who transport children in motor vehicles. There is little evidence regarding the effectiveness of these interventions, hence the need to examine what works and what does not. OBJECTIVES: To assess the effectiveness of interventions intended to increase acquisition and use of booster seats in motor vehicles among four to eight year olds. SEARCH STRATEGY: We searched the Cochrane Injuries Group's Specialized Register, the Cochrane Central Register of Controlled Trials, MEDLINE (January 1966 to April 2005), EMBASE (1980 to April 2005), LILACS, Transport Research Databases (1988 to April 2005), Australian Transport Index (1976 to April 2005), additional databases and reference lists of relevant articles. We also contacted experts in the field. SELECTION CRITERIA: We included randomized and controlled before-and-after trials that investigated the effects of interventions to promote booster seat use. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information. MAIN RESULTS: Five studies involving 3,070 individuals met the criteria for inclusion in the meta-analysis. All interventions for promoting use of booster seats among 4 to 8 year olds demonstrated a positive effect (relative risk (RR) 1.43; 95% confidence intervals (CI) 1.05 to 1.96). Incentives combined with education demonstrated a beneficial effect (RR 1.32, 95% CI 1.12 to 1.55; n = 1,898). Distribution of free booster seats combined with education also had a beneficial effect (RR 2.34; 95% CI 1.50 to 3.63; n = 380) as did education-only interventions (RR 1.32; 95% CI 1.16 to 1.49; n = 563). One study which evaluated enforcement of booster seat law met the criteria for inclusion in the meta-analysis, but demonstrated no marked beneficial effect. AUTHORS' CONCLUSIONS: Available evidence suggests that interventions to increase use of booster seats among children age four to eight years are effective. Combining incentives (booster seat discount coupons or gift certificates) or distribution of free booster seats with education demonstrated marked beneficial outcomes for acquisition and use of booster seats for four to eight year olds. There is some evidence of beneficial effect of legislation on acquisition and use of booster seats but this was mainly from uncontrolled before-and-after studies, which did not meet the criteria for inclusion in the meta-analysis.

Automobiles↗

Reliability of motor development data in the WHO Multicentre Growth Reference Study.

AIM: To describe the methods used to standardize the assessment of motor milestones in the WHO Multicentre Growth Reference Study (MGRS) and to present estimates of the reliability of the assessments. METHODS: As part of the MGRS, longitudinal data were collected on the acquisition of six motor milestones by children aged 4 to 24 mo in Ghana, India, Norway, Oman and the USA. To ensure standardized data collection, the sites conducted regular standardization sessions during which fieldworkers took turns to examine and score about 10 children for the six milestones. Assessments of the children were videotaped, and later the other fieldworkers in the same site watched the videotaped sessions and independently rated performances. The assessments were also viewed and rated by the study coordinator. The coordinator's ratings were considered the reference (true) scores. In addition, one cross-site standardization exercise took place using videotapes of 288 motor assessments. The degree of concordance between fieldworkers and the coordinator was analysed using the Kappa coefficient and the percentage of agreement. RESULTS: Overall, high percentages of agreement (81-100%) between fieldworkers and the coordinator and "substantial" (0.61-0.80) to "almost perfect" (> 0.80) Kappa coefficients were obtained for all fieldworkers, milestones and sites. Homogeneity tests confirm that the Kappas are homogeneous across sites, across milestones, and across fieldworkers. Concordance was slightly higher in the cross-site session than in the site standardization sessions. There were no systematic differences in assessing children by direct examination or through videotapes. CONCLUSION: These results show that the criteria used to define performance of the milestones were similar and applied with equally high levels of reliability among fieldworkers within a site, among milestones within a site, and among sites across milestones.

Child Development↗

Intrapleural liquid flow down a gravity-dependent hydraulic pressure gradient.

We studied the vertical movement of 2 mg technetium-labeled albumin injected intrapleurally in 0.5 ml saline (15% of pleural liquid volume) in eight spontaneously breathing anesthetized dogs subject to a sudden change in posture (prone to supine or vice versa). The albumin movements were evaluated through a large field gamma camera placed laterally to the animal and detecting total (AT) and regional activities from two superimposed equal areas (At and Ab, top and bottom, respectively). The At/Ab ratio decreased from 2.1 to 1.3 in four animals up to 20 min from the change in posture and from 0.9 to 0.5 in four more animals studied from 50 to 90 min from turning maneuver. The rate of change in At and Ab was similar in the two groups of animals and unaffected by the acquisition posture. AT decreased by 7.7 and 3.5% for the two groups, respectively, reflecting albumin clearance from the pleural space. The opposite time course of regional activities and the independence of their rate of change of the At/Ab ratio and of the animal posture suggest a top-to-bottom albumin transfer occurring through a bulk flow of liquid estimated at 0.006 ml.kg-1.h-1. The data are consistent with a measured vertical pleural liquid pressure gradient that does not reflect a hydrostatic condition.

Animals↗

Striatal D2 receptor binding in sleep bruxism: a controlled study with iodine-123-iodobenzamide and single-photon-emission computed tomography.

The neurochemical mechanisms underlying sleep bruxism are little understood at present. However, recent pharmacologic evidence suggests that the central dopaminergic system may be involved in the pathophysiology of sleep bruxism. This possibility was further assessed by means of functional neuroimaging of dopamine D2 receptors with single-photon-emission computed tomography (SPECT). Ten controls and ten patients with polysomnographically confirmed sleep bruxism were injected intravenously with 185 MBq (5 mCi) iodine-123-iodobenzamide, a specific D2 receptor antagonist radioligand, and data acquisition was performed 90 min post-injection. Following image reconstruction, it was found that striatal D2 receptor binding potential (basal ganglia/background ratio) did not differ significantly between bruxism patients and controls. However, side-to-side differences between unilateral values of the striatal D2 binding potential ("highest side" values minus "lowest side" values) were significantly larger for the bruxism patients (p < 0.001, by two-independent-samples t test with pooled variances). It was concluded that an abnormal side imbalance in striatal D2 receptor expression can be associated with sleep bruxism. This reinforces the possibility that the central dopaminergic system plays a role in the pathophysiology of this disorder.

Adult↗

End-user involvement in health technology assessment (HTA) development: a way to increase impact.

OBJECTIVES: A mechanism to increase the influence of Health Technology Assessments (HTAs) on hospital policy decisions was developed. METHODS: We describe the process and results of an experiment in which a local in-hospital HTA unit was created to provide sound evidence on technology acquisition issues, and to formulate locally appropriate policy recommendations. The Unit consists of a small technical staff that accesses and synthesizes the evidence incorporating local health and economic data, and a Policy Committee that develops policy recommendations based on this evidence. It represents administration, health-care professionals, patients, and representatives of the clinical disciplines affected by each issue. The level of success of the Unit was independently evaluated. RESULTS: To date, 16 reports have been completed, each within 2-4 months. Five recommended unrestricted use, seven recommended rejection, and four recommended very limited use of the technology in question. All have been incorporated into hospital policy. Budget impact is estimated at approximately 3 million dollars of savings per year. CONCLUSIONS: This local in-house HTA agency has had a major impact on the adoption of new technology. Probable reasons for success are (i) relevance (selection of topics by administration with on-site production of HTAs allowing them to incorporate local data and reflect local needs), (ii) timeliness, and (iii) formulation of policy reflecting community values by a local representative committee. Because over one third of all health-care costs are incurred in the hospital, diffusion of this model could have a significant effect on the quantity and quality of health-care spending.

Budgets↗

A multicenter trial on interobserver and intraobserver reproducibility of segmental scoring of thallium-201 planar myocardial imaging before and after reinjection. Italian Group of Nuclear Cardiology.

UNLABELLED: Inter- and intraobserver reproducibility (R) of segmental 201Tl scores after stress (ST), redistribution (RD) and reinjection (RI) planar imaging were evaluated. METHODS: Images were examined from 396 patients with suspected coronary artery disease, demonstrated by means of post-ST imaging of at least one perfusion defect. To eliminate external sources of variability, the same gamma camera, acquisition protocol and computer software were used in this multicenter study. Thallium-201 images of the anterior, left anterior oblique and left lateral projections were obtained immediately, 4 hr after exercise and 30 min after the injection of additional 201Tl either on the same day or on a different day. The left ventricle was divided into 15 segments and evaluated by three independent observers, blinded to clinical data, according to a five-point scale. RESULTS: The R score for ST, RD and RI images, expressed as an intraclass correlation coefficient, was 0.76, 0.74 and 0.72, respectively. After averaging multiple observer scores, R increased to 0.91, 0.90 and 0.89, respectively. Individual observer measurement of the R score was 0.48, 0.51 and 0.32 for ST-RD, ST-RI and RD-RI image pairs, respectively, and multiple observer scores showed R increases to 0.74, 0.76 and 0.58. CONCLUSION: This qualitative scale reliably assesses the severity of 201Tl perfusion defects, particularly when multiple-observer scores are averaged. Individual observer change scores should be taken with great caution, especially in studies involving the visual evaluation of RD-RI image changes.

Coronary Disease↗

Classical conditioning of the eyeblink reflex in the decerebrate-decerebellate rabbit.

The purpose of these experiments was to test the hypothesis that a conditioned nictitating membrane reflex can be acquired in decerebrate rabbits in the absence of the cerebellum. Experiments examining the effects of large cerebellar lesions on the acquisition and performance of the conditioned reflex were performed in acutely prepared decerebrate rabbits. Most lesions encompassed all of the cerebellar nuclear regions ipsilateral to the eye receiving the unconditioned stimulus. In all rabbits included in this study the continuity between the cerebellar nuclei and the brainstem was interrupted, even in those preparations in which small regions of the nuclei were present in the lateral hemisphere. The findings demonstrate that these animals could acquire the conditioned reflex independent of whether conditioning had occurred prior to the cerebellectomy. Strong associativity was found between the latency of the conditioned response and the interstimulus interval between the conditioned and unconditioned stimuli. The behavior of the conditioned reflex observed in the decerebrate-decerebellate animals differed from that reported for awake intact rabbits in two ways. Once the conditioned behavior had been acquired, the percent of trials showing conditioned responses was somewhat less in decerebrate-decerebellate rabbits and was also more variable in these animals. The data demonstrate that the nictitating membrane reflex can be classically conditioned in the absence of the cerebellum, indicating that this structure is neither necessary nor sufficient for the acquisition of this type of conditioned behavior. In addition, an hypothesis is presented which addresses the difference between the data reported here and those previously reported by other laboratories based on observations in awake intact animals.

Animals↗

mtDNA ribosomal gene phylogeny of sea hares in the genus Aplysia (Gastropoda, Opisthobranchia, Anaspidea): implications for comparative neurobiology.

Sea hares within the genus Aplysia are important neurobiological model organisms; as more studies based on different Aplysia species are appearing in the literature, a phylogenetic framework has become essential. We present a phylogenetic hypothesis for this genus, based on portions of two mitochondrial genes (12S and 16S). In addition, we reconstruct the evolution of several behavioral characters of interest to neurobiologists to illustrate the potential benefits of a phylogeny for the genus Aplysia. These benefits include determination of ancestral traits, direction and timing of evolution of characters, prediction of the distribution of traits, and identification of cases of independent acquisition of traits within lineages. This last benefit may prove especially useful in understanding the linkage between behaviors and their underlying neurological bases.

Animals↗

Competitive growth advantage of nontoxigenic mutants in the stationary phase in archival cultures of pathogenic Vibrio cholerae strains.

Spontaneous nontoxigenic mutants of highly pathogenic Vibrio cholerae O1 strains accumulate in large numbers during long-term storage of the cultures in agar stabs. In these mutants, production of the transcriptional regulator ToxR was reduced due to the presence of a mutation in the ribosome-binding site immediately upstream of the toxR open reading frame. Consequently, the ToxR-dependent virulence regulon was turned off, with concomitant reduction in the expression of cholera toxin and toxin-coregulated pilus. An intriguing feature of these mutants is that they have a competitive fitness advantage when grown in competition with the parent strains in stationary-phase cocultures which is independent of RpoS, the only locus known to be primarily associated with acquisition of a growth advantage phenotype in bacteria.

Agar↗

Estimation of age-specific rates of acquisition and loss of Wuchereria bancrofti infection.

This study uses a reversible catalytic model to estimate the age-specific rates of gain and loss of Wuchereria bancrofti infection from data collected during a control programme in Pondicherry, South India. The data describe the infection status in 1981 and 1986 of two cohorts of individuals, one living in an area where vector reduction had been achieved, and the other in a comparable endemic area. The rate of loss of infection in the absence of reinfection is estimated for the cohort in the control area, and the rate of gain of infection by the cohort in the endemic area estimated by substitution in the model. The mean expected life span of patent infection is estimated to be 5.4 years. The instantaneous rate of loss of infection is independent of age, while the rate of gain of infection exhibits a convex age-profile, peaking in the 16-20 year age-class. The reduced rate of gain in adults is largely attributable to the increasing proportion of potentially resistant individuals with clinical disease. The results suggest that the age-distribution of bancroftian filariasis is primarily determined by age-dependency in the rate of acquisition of infection.

Adolescent↗

A two-channel action-potential generator for testing neurophysiologic data acquisition/analysis systems.

A 2-channel action-potential generator system was designed for use in testing neurophysiologic data acquisition/analysis systems. The system consists of a personal computer controlling an external hardware unit. This system is capable of generating 2 channels of simulated action potential (AP) waveshapes. The AP waveforms are generated from the linear combination of 2 principal-component template functions. Each channel generates randomly occurring APs with a specified rate ranging from 1 to 200 events per second. The 2 trains may be independent of one another or the second channel may be made to be excited or inhibited by the events from the first channel with user-specified probabilities. A third internal channel may be made to excite or inhibit events in both of the 2 output channels with user-specified rate parameters and probabilities. The system produces voltage waveforms that may be used to test neurophysiologic data acquisition systems for recording from 2 spike trains simultaneously and for testing multispike-train analysis (e.g., cross-correlation) software.

Action Potentials↗

[Meticillin-resistant Staphylococcus aureus: incidence, risk factors and interest of systematic screening for colonization in intensive-care unit].

OBJECTIVE: To summarize recent international and national epidemiological data of methicillin-resistant Staphylococcus aureus (MRSA) colonization in ICU. STUDY DESIGN: Review articles using Medline, CDC (Atlanta, GA, USA) and IVS (St Maurice, France) databases (1994-2004): critical assessment of literature and data of MRSA colonization epidemiology in ICU. RESULTS: MRSA colonization varied from 3 to 14% on ICU admission. Five to twelve percent of patient acquired MRSA colonization during hospitalization. This reservoir is often unknown as clinical sample identifies only a part of MRSA colonization. The probability to develop an infection caused by MRSA in colonized patients is about 30%. Acquisition of MRSA in ICU patients is strongly and independently influenced by colonization pressure. CONCLUSION: Systematic screening for colonization on ICU admission and during hospitalization is essential for many authors to control the spread of MRSA. Other policies such as implementation of isolation precaution and antibiotic use also contribute to decrease the MRSA incidence rate observed for several years in French ICU.

Anti-Bacterial Agents↗

The closed equilibrated biological aquatic system: a 12 months test of an artificial aquatic ecosystem.

The Closed Equilibrated Biological Aquatic System" (C.E.B.A.S.) is finally disposed for long-term multi-generation experiments with aquatic organisms in a space station. Therefore a minimum operation time of three months is required. It is verified in three versions of laboratory prototypes. The third one passed successfully a 12 months mid-term test in 1995/96 thus demonstrating its high biological stability. The third version of the C.E.B.A.S. consists of a 100 l animal tank, two plant cultivators with a volume of 15 l each with independent illuminations, a 3.0 l semibiological "mechanical" filter, a 3.0 l bacteria filter, a heating/cooling device and a dummy filter unit. The live-bearing teleost Xiphophorus helleri is the vertebrate and the pulmonate water snail Biomphalana glabrata the invertebrate experimental animal in the system. The rootless higher water plant Ceratophyllum demersum is the producer organism. Ammonia oxidizing bacteria and other microorganisms settle in the filters. A sample data acquisition is combined with temperature and plant illumination control. Besides of the space aspects the C.E.B.A.S. proved to be an extremely suitable tool to investigate the organism and subcomponent interactions in a well defined terrestrial aquatic closed ecosystem by providing physical, chemical and biological data which allow an approach to a comprehensive system analysis. Moreover the C.E.B.A.S. is the base for the development of innovative combined animal-plant aquaculture systems for human nutrition on earth which could be implemented into bioregenerative life support systems with a higher degree of complexity suitable for lunar or planetary bases.

Animals↗

The dynamics of microfilaraemia and its relation with development of disease in periodic Brugia malayi infection in south India.

Rates of acquisition and loss of Brugia malayi microfilaraemia were estimated using the parasitological data of a cohort of population in Shertallai, South India. The rate of acquisition of microfilaraemia was found to be dependent on age but not gender. The decline in the rate of acquisition of microfilaraemia in adults above 35 years could be due to the development of acquired immunity. The mean reproductive lifespan for the periodic Brugia malayi adult female worm was estimated to be 3.4 years and it was independent of host age and gender. The age-specific estimated proportion of population at risk (microfilaria carriers who lost their microfilaria in course of time) of developing lymphoedema approximately mirrored the observed age specific prevalence of lymphoedema in the study population. On an average, 99% of population at risk developed disease in different endemic areas is compared and its epidemiological significance is discussed.

Adolescent↗

Accuracy of quantitative MR vessel wall imaging applying a semi-automated gradient detection algorithm--a validation study.

UNLABELLED: Magnetic resonance imaging (MRI) is uniquely suited to study the pathophysiology of arteriosclerosis. So far, magnetic resonance (MR) measurements of vessel dimensions have mainly been done by manual tracing of vessel wall contours. However, such data postprocessing is very time-consuming and has limited accuracy due to difficulties in precise tracing of the thin vessel wall. PURPOSE: To assess the accuracy and reproducibility of quantitative vascular MR imaging applying a data analysis method based on (1) vessel wall unwrapping, followed by (2) a gradient detection algorithm for MR data postprocessing. Vascular MR imaging studies were done both in vessel phantoms and in healthy volunteers (n=29) on a clinical 1.5 T MR scanner. A dark blood double-inversion turbo spin echo sequence with fat suppression was applied, with proton-density-weighted and breath-hold acquisition for aortic imaging and T2-weighted acquisition for carotid imaging. Intraobserver and interobserver variability were systematically evaluated by two independent observers. A repeat study within 10 days of the first MRI was performed in 10 of these subjects for assessment of interstudy reproducibility. RESULTS: The semiautomated edge detection software revealed a clear view of the inner and outer vessel wall boundaries both in the phantoms and in the volunteers studied. There was close agreement between MR-derived measurements and phantom dimensions (mean difference of 1.1+/-16.9 mm2, 8.0+/-19.9 mm2, 9.0+/-12.1 mm2 for vessel wall cross-sectional area, inner vessel area, and total vessel area, respectively). Quantification of vessel dimensions was feasible in all 29 healthy volunteers studied. Semiautomated quantification of cross-sectional vessel wall area (mean+/-SD, 253.6+/-208.4 mm2) revealed close correlation for repeated measurements by one or two observers (r=0.99 each). Both intraobserver and interobserver variability of vessel wall area MR measurements were low (mean difference 7.5+/-16.7 mm2 and 14.4+/-24.6 mm2 , respectively). In the repeat study of 10 volunteers, MRI with semiautomated postprocessing quantitation revealed a high correlation and agreement of vessel dimensions between the two scans (r=0.994, mean difference 2.6+/-25.1 mm2). CONCLUSION: Semiautomated analysis methods can provide approaches that benefit from the human understanding of the image and the computer's ability to measure precisely and rapidly. Thus, by combining the latest MRI methods and semiautomated image analysis methods, we are now able to reproducibly determine the geometric parameters of blood vessels.

Adult↗