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PubMed1992

Radioimmunoassay data handling and calculations with a graphics-statistics computer program.

This paper discusses the application of the data handling-graphics-statistics program Stata (Computing Resources Center, Santa Monica, CA) to radioimmunoassay. We have found that this program is more powerful and easier to use than a spreadsheet for analyzing various kinds of laboratory data generated from chromatography, radiolabeling experiments, enzyme-linked immunosorbent assays, and radioimmunoassays, to name several examples. Data from a radioimmunoassay procedure, originally analyzed using a spreadsheet, Lotus 1-2-3, have been processed with Stata. Simple programs (batch files) have been devised for computations and graphics. The original data and a comparison of results are presented.

Radioimmunoassay↗
PubMed1978

Interactive computer surface graphics approach to study of the active site of bovine trypsin.

A descriptive medium for the presentation of protein structure has been developed and used to evaluate the structure of the active site of bovine trypsin (EC 3.4.21.4). This technique, involving advanced computer graphics technology, permits the facile display of a representation of the molecular surface of proteins of known structure and employs color to code the structural or chemical features of this surface. Benzamidine derivatives were inserted into the benzamidine-binding site of trypsin and the binary inhibitor-trypsin complex was evaluated by using the computer-generated structure. On the basis of qualitative assessments of the contribution of electrostatic and hydrophobic forces to the binding energy associated with complex formation, we made predictions concerning the effects of interaction of benzamidine substituents and amino acid side chains upon the binding energy associated with inhibitor-protein binding. The computer display of the molecular surfaces of the binary complex of substituted benzamidines and trypsin permitted unique insight into the identity and chemical properties of the atoms that participate at the interface of the molecular surfaces of the inhibitor and the protein. The computer-generated molecular surface display can potentially be combined with quantitative definition of the physical forces involved in the interaction of molecular surfaces. This technology should facilitate the study of the structure-activity relationship of substrates, inhibitors, and drugs that bind to proteins of known three-dimensional structure.

Animals↗
PubMed1992

[Comparison of fingerprints using a personal computer and graphic software sold on market].

We compared the fingerprint images using a personal computer and a graphic software sold on market. The fingerprints of thumb of left hand recorded by pressing and rolling on paper were input in computer using image scanner. These two fingerprint images were overlapped by moving and rotation on the computer screen, and were fitted well. This result showed that the fingerprints recorded by any way from one person were fitted. Latent and accused's fingerprints were also input in computer using image scanner. These images were analyzed by the same procedure. These two fingerprints were part by unfitting. It was decided these two fingerprints were not derived from one person. We also considered the possibility that the latent fingerprint was the reversed one. Then, the image was reversed of its color on the screen of computer (black to white and white to black) and compared by the same procedure. In this experiment, two fingerprint images were not fitted in a part. This showed that the reversed fingerprint was also able to be analyzed by this procedure. For the comparison of fingerprints, this report showed the ability of the personal computer and software which can be obtained easily from market. Following the improvement of the hardware and software used in this examination in near future, the computerized identification of fingerprints like this study will become more accurate and convenient.

Computer Graphics↗
PubMed1991

Two-dimensional computer color graphics of gastric mucosal blood distribution in normal subjects and ulcer patients.

The mucosal blood volume in 20 to 24 different regions of stomach was estimated by reflectance spectrophotometry during endoscopy, and an image showing mucosal blood distribution was made by two-dimensional computer color graphics with the aid of a personal computer. In 55 normal controls, the estimated mucosal blood volume (EMBV) was greater in the corpus mucosa than in the antral mucosa, and less in the lesser curvature than in the greater curvature. The volume in the anterior and posterior walls was almost the same. In 15 patients with active gastric ulcers in the angular region, the EMBV was decreased in all regions in the stomach. In 37 patients with healing ulcers, the EMBV increased, resuming the same levels as in normal controls. However, the EMBV around the ulcer increased remarkably at this stage. In 35 patients with ulcers in the scarring stage, the distribution of the EMBV was similar to that in the normal controls. These hemodynamic changes were shown clearly in a color display with the aid of a personal computer. This method could offer new possibilities in endoscopic research.

Adult↗
PubMed1991

Model for the structure of formaldehyde dehydrogenase based on alcohol dehydrogenase.

The three-dimensional structure of rat liver formaldehyde dehydrogenase (FALDH), previously known as class III alcohol dehydrogenase, was constructed using computer graphics and computer programs developed for model building. The construction is based on horse liver alcohol dehydrogenase (EE-ADH), whose structure has been elucidated by X-ray crystallography. The high sequence homology between the two enzymes makes knowledge-based modelling feasible in this case. The model shows a remarkable similarity to horse liver alcohol dehydrogenase especially in the NAD-binding domain. Certain mutations, and the one insertion in FALDH compared to EE-ADH in particular, have cause important changes in the substrate binding site, and thus aliphatic alcohols have been replaced by hemi-thioacetals as favourable substrates.

Alcohol Dehydrogenase↗
PubMed1991

Displaying inter-main chain hydrogen bond patterns in proteins.

Two computer graphics techniques for displaying hydrogen bonds between the main chains of different proteins are described, and illustrated for two thiol proteases. (The X-ray crystallography was performed by Kamphuis et al. in 1984, and by Baker and Dodson in 1980.) One is a three-dimensional model that can be manipulated in space; the hydrogen bonds are represented with the smoothed alpha-carbon plot of the polypeptide chain. In the other type of display, hydrogen bonds are viewed in relation to the one-dimensional sequence. Both types of picture facilitate visualization of hydrogen bond patterns, such that loop motifs, as well as alpha-helices and beta-sheets, can be examined easily. We suggest that such displays are useful as a general means of displaying whole proteins and whole domains because they reveal more information than do conventional simplified pictures of proteins, which focus exclusively on alpha-helices and beta-sheets. These techniques can be implemented on a UNIX-based computer graphics workstation. (UNIX is a trademark of Bell Telephone laboratories.)

Computer Graphics↗
PubMed1976

Morphological correlates of synaptic transmission in lamprey spinal cord.

The dye Procion brown was used to identify in the light and electron microscope, synaptic contacts made between monosynaptically coupled neurons in the lamprey spinal cord whose synaptic interaction had been recorded. Synaptic contacts were made on different dendrites of the postsynaptic cell at different distances from the soma. Some of the contacts were made on dentritic spines and some on the smooth shaft of the dentrites. Serial sections through synaptic contacts made on dendritic processess of the postsynaptic cells were used for three-dimensional reconstruction of the synapses using computer graphics techniques. The computer reconstructions and detailed examination of the serial EM micrographs revealed the large proliferation of membrane involved in making these en passant synapses as well as the morphological changes due to stimulation of the presynaptic axon. These changes include depletion of synaptic vesicles and formation of complex vesicles and synaptic cisternae. Besides chemical synaptic contacts, four electrotonic contacts were located, confirming the mixed electrochemical synaptic response recorded from the postsynaptic cell. The mean quantum content was estimated and compared with the estimate of the available transmitter pool, assuming the quantal release hypothesis applies at these synapses. The total transmitter pool was estimated by counting all synaptic vesicles in all synaptic contacts. It was estimated that about 6% of the total transmitter pool is available for release at these synapses. This compares with less than 1% at the neuromuscular junction and about 20% at sympathetic synapses. These results support the hypothesis that synaptic vesicles may be recycled as described by Heuser and Reese (22) at the neuromuscular junction. Ongoing studies are investigating the effect on a variety of synaptic junctions to stimulation for different periods of time of presynaptic axons. The methods described in this study can also be used to test the models of synaptic interaction on dendritic trees described by Rall (39) and Jack and Redman (24).

Action Potentials↗
PubMed1992

Stereolithographic models for surgical planning: preliminary report.

Recent application of computer graphics, using standardized cephalometric analyses, have allowed the surgeon to visualize the predicted surgical outcome on the computer video monitor. Stereolithographic models constructed from digital image data (computed tomography and magnetic resonance) will allow the surgeon to view the external and internal anatomy prior to surgery. This article describes the development of such technology and reports its use in one case.

Adult↗
PubMedDate not supplied

A medical workstation for the evaluation of alternative 3D radiotherapy treatment plans.

A medical workstation for the evaluation of alternative 3D radiotherapy plans is described. Our system can simultaneously apply qualitative as well as quantitative evaluation methods to as many as three 3D dose distributions. The user interface of the workstation has been designed with the demands of radiation oncologists in mind. The handling of the large amounts of 3D data (CT data, up to three 3D dose distributions, volumes of interest) is assisted by computer graphics.

Computer Graphics↗
PubMed1978

Computer-generated graphic models of the N2-substituted deoxyguanosine adducts of 2-acetylaminofluorene and benzo[a]pyrene and the O6-substituted deoxyguanosine adduct of 1-naphthylamine in the DNA double helix.

Computer models of three deoxyguanosine-carcinogen adducts in double-helical DNA are presented. The carcinogen moiety is rotated and the best fit within the double helix is evaluated. The 2-acetylaminofluorene (AAF) derivative, 3-(deoxyguanosin-N2-yl)-AAF, is found to be situated within the minor groove, has very little freedom of rotation and causes little helical distortion. The (+)-anti-benzo[a]-pyrene (BP)-diol epoxide-N2 adduct, 10beta-(deoxyguanosin-N2-yl)-7beta, 8alpha,9alpha-trihydroxy-7,8,9,10-tetrahydro-BP, has a similar fit with a greater degree of steric interaction, suggesting that this adduct could cause some local destabilization. The 1-naphthylamine (NA) derivative, N1-(deoxyguanosine-O6-yl)-1-NA, resides within the major groove, does not perturb the helix and has considerable freedom of movement.

1-Naphthylamine↗
PubMed1989

Imaging workstations for computer-aided primatology: promises and pitfalls.

In this paper, the application of biomedical imaging workstations to primatology will be explained and evaluated. The technological basis, computer hardware and software aspects, and the various uses of several types of workstations will all be discussed. The types of workstations include: (1) Simple - these display-only workstations, which function as electronic light boxes, have applications as terminals to picture archiving and communication (PAC) systems. (2) Diagnostic reporting - image-processing workstations that include the ability to perform straightforward manipulations of gray scale and raw data values will be considered for operations such as histogram equalization (whether adaptive or global), gradient edge finders, contour generation, and region of interest, as well as other related functions. (3) Manipulation systems - three-dimensional modeling and computer graphics with application to radiation therapy treatment planning, and surgical planning and evaluation will be considered. A technology of prime importance in the function of these workstations lies in communications and networking. The hierarchical organization of an electronic computer network and workstation environment with the interrelationship of simple, diagnostic reporting, and manipulation workstations to a coaxial or fiber optic network will be analyzed.

Animals↗
PubMed1991

HAMOG: molecular graphics program for chemistry, biochemistry, molecular biology and enzyme research.

HAMOG is a computer graphics program written in C for personal computers. Clear menus and a context-sensitive help option make the program easy to operate for occasional users. HAMOG provides a flexible environment for displaying and manipulating molecules and molecular systems. Special functions allow the investigation of structure-activity relationships of biologically active molecules. These include the calculation of molecular electrostatic potentials and fields, the superposition of molecules and the calculation of steric accessibilities. The visualization and manipulation of protein structures immediately readable from the Brookhaven Protein Data Bank files are also possible using HAMOG. The construction of any peptide or protein structure is very simple.

Chemical Phenomena↗
PubMed1991

Computer- and robot-assisted resection of thalamic astrocytomas in children.

Six children ranging in age from 2 to 10 years who harbored deep benign astrocytomas were operated upon using a computer- and robot-assisted system. A radical excision was achieved in all cases with no significant morbidity nor any mortality. The system consists of an interactive, three-dimensional display of computed tomographic image contours and digitized cerebral angiograms taken using the Brown-Roberts-Wells stereotactic frame. The surgical retractor is held and manipulated using a PUMA 200 robot. The position and orientation of the surgical retractor is displayed on the three-dimensional display. Preoperative planning and simulation are important features of this system. Movement of the brain after removal of the tumor and cerebrospinal fluid is substantial, so the tumor removal is based on visually defined margins. Enhanced computer graphics and robotic devices are important adjuncts to neurosurgical procedures and will find increasing use in the future.

Astrocytoma↗
PubMed1987

Motor end-plate distribution in the human interarytenoid muscle.

Histochemical and computer graphic techniques were used to determine the distribution of neuromuscular junctions in the human interarytenoid (IA) muscle. The motor end-plates of four IA specimens obtained from normal postmortem larynges were visualized using an acetylcholinesterase stain. The three-dimensional distribution of motor end-plates was later reconstructed using computer graphics. The motor end-plates in the IA were found to be distributed in an inverted "Y" configuration. A broad band of end-plates was found at the midpoint of the muscle fibers in the superior and middle aspect of the muscle. This band divided obliquely in a lateral direction toward the inferior border of the muscle. This pattern of motor end-plate distribution is possibly consistent with the bilateral innervation of the IA by the recurrent laryngeal nerves.

Adult↗
PubMed1990

On the development of an integrated computer system for cephalometric analyses.

This paper describes a microcomputer based system that integrates image processing and computer graphics techniques to automate the data extraction and storage process in cephalometric analyses. The system increases the consistency of measurements and improves the productivity of surgical and dental staff.

Cephalometry↗
PubMedDate not supplied

Quantitative changes in fissure sealant six months after placement.

Earlier studies have reported extensive volumetric loss of fissure sealant shortly after placement. To determine the volume of fissure sealant lost at six months, we used a servohydraulic profilometric apparatus in combination with computer graphics. Twenty-two premolar teeth were selected, and baseline silicone impressions were made of each tooth. The teeth were sealed and the occlusion adjusted where necessary. Impressions were made immediately of sealed teeth and again at six months. Epoxy replicas were made from all impressions, and their surfaces digitized by sequential profilometry. Using a three-dimensional root mean square (RMS) goodness-of-fit computer program, before sealant, after sealant, and six months after sealant computer-graphic images were superimposed. The volume of sealant lost after six months for all premolar teeth was X = 0.23 mm3 (maxillary second premolar: N = 9, X = 0.29 mm3; maxillary first premolar: N = 5, X = 0.27 mm3; mandibular second premolar: N = 4, X = 0.20 mm3; mandibular first premolar: N = 4, X = 0.08 mm3). The volume differences between tooth groups were not significant as measured by analysis of variance (ANOVA). These volumes represented a 13.99% loss of applied sealant for all premolars (maxillary second premolar: 19.72%; maxillary first premolar: 15.37%; mandibular second premolar: 8.46%; mandibular first premolar: 6.37%). The area of wear and the depth of wear also were measured.

Humans↗
PubMed1992

Towards 3-D modelling of epithelia by computer simulation.

The present work is a preliminary step towards dynamic 3-D modelling by computer graphics simulation of the structure of normal and pathological epithelia, using an expert system. In its present state, Esexsy (Epithelium Simulation by EXpert SYstem) allows the construction, through iterative steps, of a simple 3-D representation of the nasal epithelium, based on the positions, sizes and shapes of nuclei. The iterative process is based on statistical comparisons between distributions of parameter values calculated from real (2-D) histological sections and those issued from an equivalent computer 'section' through the simulated 3-D image. We show the results of attempts at simulating normal, metaplastic and dysplastic states of the nasal epithelium, the latter two being characterized by a progressive architectural disorganization, accompanied by nuclear size/shape alterations. The representation takes into account the size, shape, orientation and spatial arrangement of nuclei, with one or several layers from the basal lamina to the lumen. A modified Poisson point process is used at present to position the nuclei, which are modelled by bi-axial spheroids (from prolate to oblate through spherical), with random orientation and size/shape deviations. It should be possible to use the same computer program to simulate other types of epithelia and to achieve increasingly realistic representations by incorporating, notably, nuclear deformations and chromatin texture.

Computer Graphics↗