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PubMed1981

Real-time color graphics in studies of molecular interactions.

Studies of the structures and interactions of large biological molecules require both coordinate data and three-dimensional visualization. Orthodox molecular models often bear a tenuous relationship to the coordinate data. In contrast, computer graphics requires that the display directly and accurately represent the data, and storage of modified configurations and recovery of original structures are simple. Software has been developed that allows real-time display of color line and surface displays of several interacting molecules, while quantitatively monitoring the stereochemistry.

Carboxypeptidases↗

PubMedDate not supplied

Mixing Apple microcomputer graphics for ultrasound scan measurement.

A modern microcomputer with high-resolution graphics can provide an inexpensive method for measurement on video images from a real-time ultrasound scanner. The problem which has to be overcome to allow the computer graphics to be superimposed on the ultrasound video image and permit subsequent analysis is that of synchronization. The video signals must be synchronized before they can be mixed, but neither microcomputers nor ultrasound scanners provide facilities for external synchronization of their video output. A mixer has been designed which uses a buffer memory and allows the graphics of an Apple II microcomputer to be synchronized and mixed with an external video image; we used a Hitachi EUB22 real-time ultrasound scanner. The resulting combination is a versatile instrument which permits a wide range of measurements on ultrasonic images.

Computers↗

PubMed1983

Computer-assisted modeling of the picrotoxinin and gamma-butyrolactone receptor site.

Three-dimensional models of the picrotoxinin and alkyl-substituted gamma-butyrolactone (GBL) receptor sites were constructed with the aid of a molecular graphics computer system (MMS-X). These two independently derived models proved to be very compatible, which suggested that both types of compounds share a common site of action. Since picrotoxinin is known to act at gamma-aminobutyric acid-regulated chloride channels, a hypothesis was made and tested that the convulsant GBL and picrotoxinin analogues physically impede the passage of chloride ions through the channel. It was also shown that it was theoretically possible for the anticonvulsant GBLs to act at this same site without blocking chloride flux. Finally, the model was applied to several convulsant and anticonvulsant compounds of different chemical classes and was found to be of somewhat general applicability.

4-Butyrolactone↗

PubMed1997

Dissociable effects of cingulate and medial frontal cortex lesions on stimulus-reward learning using a novel Pavlovian autoshaping procedure for the rat: implications for the neurobiology of emotion.

The effects of quinolinic acid-induced lesions of the anterior cingulate, posterior cingulate, and medial frontal cortices on stimulus-reward learning were investigated with a novel Pavlovian autoshaping procedure in an apparatus allowing the automated presentation of computer-graphic stimuli to rats (T. J. Bussey, J. L. Muir, & T. W. Robbins, 1994). White vertical rectangles were presented on the left or the right of a computer screen. One of these conditioned stimuli (the CS+) was always followed by the presentation of a sucrose pellet; the other, the CS-, was never followed by reward. With training, rats came to approach the CS+ more often than the CS-. Anterior cingulate cortex-lesioned rats failed to demonstrate normal discriminated approach, making significantly more approaches to the CS- than did sham-operated controls. Medial frontal cortex-lesioned rats acquired the task normally but had longer overall approach latencies. Posterior cingulate cortex lesions did not affect acquisition.

Animals↗

PubMed1998

[Three dimensional reconstruction of human permanent teeth].

OBJECTIVE: Dental anatomy is one of the most important basic courses in the education of stomatology. The deep understanding of morphologic characters is closely instructive to the clinic of endodontics, oral surgery, orthodontics and prosthodontics. METHODS: In present study, 32 permanent teeth from a skull specimen were inputted into computer after the processes of burying, grinding, photographing, scanning and recognizing. By the techniques of reconstruction, the 3D stereo tooth models were retrieved from 2D digital data. RESULTS: On the basis of those 3D data, computer graphics techniques were used to realize the lighted, smoothed and shaded teeth. CONCLUSION: Such a series of data teeth might be applicated as a corner stone of the computer aided instruction (CAI) in stomatology.

Computer-Assisted Instruction↗

PubMed1992

Continuing medical education software: a comparative review.

Personal microcomputers can be used by physicians for continuing medical education (CME). Advantages of computerized CME include local control over the topic, time, place, and pace of instruction. Computers can be interactive, providing selected information that depends on the desires and needs of the physician. Learners have different preferred styles of receiving information, and computer programs can be written to appeal to a particular style of learning. Three examples of commercial software programs available for CME are reviewed. Cyberlog should appeal to those who like to learn from reading textbooks but also desire simple computer graphics and case simulations to reinforce key concepts. Patient Simulator II is a detailed patient simulation for those who learn best by doing. A subscription to Discotest provides patient management problems, and multiple choice questions (no graphics) based on information in Scientific American Medicine. No one program is suitable for all family physicians.

Computer Simulation↗

PubMed1990

Applications of computer technology in dentistry.

Technological advances in industrial manufacturing have contributed to improvement in productivity and quality of dental care. However, computer technology has also been exploited but not to the same extent as other forms of technology. This paper examines computer applications that have been utilised by various groups of dental professionals in the provision of dental care and in dental education. The benefits derived from existing applications and future possibilities are seen in the following fields. In practice management, besides the usual collecting, sorting and searching of data, productivity and efficiency are greatly increased through computer appointments, recall and practice analysis programmes. In patient education, the use of computer graphics has enabled simulation of cosmetic changes to be presented to the patient with before and after possibilities. Dental education and communications have moved forward with the introduction of Computer Assisted Instruction programmes, and bibliographic databases including electronic transmission of Continuing Dental Education which are now easily available. In the field of Diagnostics and Treatment planning, the advent of CAD-CAM has made possible the use of cutting devices which mills a 3-dimensional model of the designed restoration from solid blocks of gold. Computer applications has also been used in forensic dentistry where identification systems describe tooth conditions and other oral characteristics besides automated screening and matching of antemortem databases.

Computer-Assisted Instruction↗

PubMed1999

[Informationization policies of local governments].

In line with the rapid progress in technical innovation, the wave of informationization is now reaching every aspect of Japanese society. With the explosive spread of the Internet, local governments are implementing administrative policies to facilitate the construction of information network systems which will help promote the spread of information at the local level. The Ministry of Posts and Telecommunications, the Ministry of International Trade and Industry, and other organizations of the Japanese government are also implemending a variety of measures to assist these moves on the part of local governments. A look at administrative services for local residents reveals a great need for the proliferation of information within the areas of welfare and medical care; in particular, counselling concerning nursing care and medical services in remote areas are needed. In order to realize new measures promoting informationization, however, the cooperation and understanding of local governors or mayors are essential. Because these people are very busy, short video and computer graphic presentations should be prepared in order to make the greatest impact in the least amount of time.

Computers↗

PubMed2006

A computer method for assessing satisfaction with hearing aids.

The purpose of this study was to evaluate a new clinical assessment, the Dynamic Assessment of Hearing Aids (DAHA), for a large clinical population. Unlike traditional questionnaire methods, the DAHA has patients use an intuitive graphical computer interface to record visual analogue ratings of satisfaction with various features of their hearing aids (e.g. clarity, cost, appearance). Data were collected from 191 participants.A subset of participants returned for retest. The DAHA items assess satisfaction with hearing aids within four domains: communication, physical features, sound quality, and personal reactions. The concurrent validity was determined by comparing DAHA results to those obtained with the satisfaction with amplification in daily life (SADL). Ratings for personal reactions to hearing aids indicate the most satisfaction, and ratings for communication (especially group conversations and phone use) indicate the least satisfaction. The DAHA total score was found to have good test/retest and high internal consistency. Concurrent validity was supported by a strong correlation between total scores on the DAHA and the SADL. Results suggest the DAHA maybe an effective tool for clinical use.

Activities of Daily Living↗

PubMed1984

Computerized reconstruction of an anatomical structure based on digitized sections. Preliminary study.

The authors propose a technique of spatial reconstruction of serial sections using the modern methods of computer graphics. The technical problems encountered and the duration of the classical Born method render the proposed technique difficult to apply as a routine procedure. The results of this work show that computer assisted image reconstruction could be used in daily routine work only when appropriate software programs and sufficient memory capacity become available to allow rapid image restitution. With the technique described in this paper, the reconstruction and display of a single image require 7 to 8 h of computer time.

Computers↗

PubMed1988

Molecular modelling in design of crop protection chemicals.

Specific examples from pesticide research are given which illustrate the types of analysis employed to design optimal inhibitors for a given receptor, based on the assumption that a congeneric series of compounds behave in a related mode in the biosystem. The examples illustrate the complementary role played by computational chemistry, X-ray crystallography and computer graphics and also raise questions as to the current limitations of existing molecular mechanics and quantum mechanics techniques.

Agriculture↗

PubMed1998

VR simulation of abdominal trauma surgery.

In this paper we describe a test-bed we have developed for simulation of abdominal trauma surgery. The abdominal surgery scene is highly complex and contains many layers of deformable organs. Representing this layered and deformable anatomy with models that can interact, be probed and cut presents a unique challenge. We have met this challenge by applying a variety of technology advances in deformable models, computer graphics, and force-feedback (haptic) interfaces.

Abdominal Injuries↗

PubMed1990

Mechanism of the in vitro antimutagenic action of retinol.

The antimutagenic action of retinoids against three amino-imidazoazaarene pre-carcinogens, i.e. 2-amino-3-methylimidazo(4,5-f)quinoline (IQ), 2-amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ) and 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline (MeIQx), was investigated using the Ames test and hepatic activation systems derived from rats pretreated with Aroclor 1254. Both retinol and retinal, when incorporated into the S9 activation system, gave rise to a concentration-dependent decrease in the mutagenicity of all three mutagens, retinol being generally the more effective. Retinol suppressed the mutagenic activity of IQ even when isolated microsomes were used as activation systems. Moreover, retinol gave rise to a concentration-dependent inhibition of the microsomal dealkylations of pentoxy- and benzyloxy- and, especially, ethoxy-resorufin, but had no effect on the NADPH-dependent reduction of cytochrome c. Exposure of the bacteria to retinol with subsequent removal of the vitamin did not influence the mutagenicity of IQ. It is concluded that retinoids suppress the mutagenicity of aminoimidazoazaarenes and this is achieved through inhibition of their cytochrome P450-dependent metabolic activation. Retinol is a non-selective in vitro inhibitor of the hepatic cytochrome P450-dependent mixed function oxidase system as predicted by a computer graphic analysis of its molecular shape.

Animals↗

PubMed1987

An "expanded stick" model for coding Golgi-impregnated neuronal morphology.

A new model for coding Golgi-impregnated neuronal morphology, which can be implemented in any computer-assisted optical microscope, is described. This model, in addition to storing the three-dimensional coordinates of the selected neuronal points and their topological identifiers, codes for "width", "nature", and "shape". The "width" code digitizes the width of a neuronal process. The "nature" code can identify structures such as perikaryon, axon, apical dendrite, basal dendrite, etc. The "shape" code defines nodules and spines. Computer graphics routines are described for drawing nodules and spines as well as neuronal processes with "width".

Animals↗

PubMed1989

A method for MRI and CT mapping of diencephalic somatotopography.

The author presents a method for the mapping of diencephalic somatotopography by the use of computerized image acquisition of CT and/or MRI scans with a computer graphics technique. Data gathered from exploratory stimulation and recordings during the normal course of stereotactic surgical procedures can then be used with this image acquisition and graphics technique for composing diencephalic somatotopographical maps.

Brain Mapping↗

PubMed1997

[Evaluation of peroperative measurement system in the follow-up of vertebral displacements].

A computer assisted surgery system has been developed to quantify the vertebral displacements induced by the Cotrel-Dubousset instrumentation and to visualize in 3-D the spine at different per-operative steps. This spinal surgery is realized to correct idiopathic scoliosis. Per-operative measurements are obtained by using a magnetic digitizer. Five points per thoracic vertebra and six points per lumbar vertebra are digitized. The method proposed estimates the location of the digitized points on a computer graphics 3-D model of vertebrae by a point-to-surface matching algorithm. The 3-D models are constructed before the surgery using multiplanar radiographic reconstruction technique (2 or 3 views) and geometric modeling methods. Computer tools permit the 3-D visualization of the spine peroperatively and the evaluation of clinical indices such as Cobb angles and vertebral rotations. The system includes 3 principal error sources: 2) reconstruction error; 2) digitizer error (digitizer precision) and 3) point-to-surface matching error. In order to validate the overall system, measurements have been simulated for 2 vertebrae and 2 digitizers of different precision, taking onto account the reconstruction error. For 5 and 6 digitized points per vertebra, the matching algorithm gives a RMS error of respectively 3.0 and 2.0 mm.

Biomechanical Phenomena↗

PubMed1990

Localization of visually evoked cortical activity using magnetic resonance imaging and computerized tomography.

Evoked scalp potentials, computerized tomography, and magnetic resonance imaging were used together to localize cortical activity evoked by visual stimuli in humans. The temporal resolution of evoked potential measurements is sufficient to track the flow of cortical activity which evolves in epochs of a few tens of msec. Spatial localization was enhanced by deconvolving scalp potential fields with a Laplacian operator. Markers glue to the scalp served to unify the three geometric reference frames into a single computer graphics database.

Brain Mapping↗

PubMed1985

Computerized prediction of the results of orthognathic surgery.

Methods of visually and numerically predicting the results of orthognathic treatment are reviewed. The use of a computer program written by the authors and employing computer graphics for orthognathic prediction is described and illustrated. Suggested advantages and disadvantages of such a method are discussed.

Cephalometry↗