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PubMed2001

Immunoreactive relaxin in seminal plasma of fertile boars and its correlation with sperm motility characteristics determined by computer-assisted digital image analysis.

Ejaculates from 10 mature fertile large white Yorkshire boars were used to examine the correlation between immunoreactive relaxin levels in seminal plasma and sperm motility characteristics. Seminal plasma levels of immunoreactive relaxin were measured by a time-resolved fluoroimmunoassay (TR-FIA). Motility characteristics were assessed using a CellSoft computer-assisted digital image analysis system. The mean +/- SD level of immunoreactive relaxin in seminal plasma was 2.61 +/- 0.62 ng/mL. When the correlation between seminal plasma levels of immunoreactive relaxin and parameters of sperm movement was examined, it was found that relaxin levels were significantly correlated with the percentage of motile spermatozoa (r=0.687, p < 0.05), curvilinear velocity (r=0.745, p < 0.05), straight line velocity (r=0.651, p < 0.05), mean amplitude of lateral head displacement (mean ALH) (r=0.844, p < 0.01) and the maximum amplitude of lateral head displacement (max ALH) (r=0.830, p < 0.01), but not with linearity, beat-cross frequency, or percentage of circular cells. Among these parameters, seminal plasma levels of immunoreactive relaxin showed the strongest correlation with the ALH parameter related to fertilizing ability. These results indicate that immunoreactive relaxin in boar semen may be necessary not only for normal sperm motility but also for normal fertility, suggesting that determination of the profile of immunoreactive relaxin in ejaculates may have value as a potential marker for predicting sperm fertilizing ability of boars.

Animals↗
PubMed1991

Secretory pathway of vitellogenesis in the liver of the cockerel as revealed by immuno-gold and computer-assisted digitization techniques.

The protein A-gold immunocytochemical technique was used to localize the secretory pathway of oestradiol-induced vitellogenin in hepatic parenchymal cells of the cockerel. Liver was removed from experimental birds on the 1st, 4th and 8th day following oestradiol-treatment, and embedded in Lowicryl K4M resin cured at -20 degrees C. In selected electron micrographs the fractional surface area of each of the intracellular compartments was measured by the computer-assisted digitization technique. Labelling was detected over the cisternae of the rough endoplasmic reticulum (RER), the Golgi apparatus, the immature secretory vacuoles (ISV) including condensing vacuoles and the mature secretory vacuoles (MSV). Counts of the gold particles demonstrated an increasing concentration which progressed in the order RER less than Golgi less than ISV less than MSV and identified the secretory pathway of the protein. The highest density of labelling was obtained on the 4th day, when vitellogenin reaches its peak activity. Autophagic activity (or crinophagy) was also found in lysosomes and its labelling intensity increased daily. A hypothesis concerning the secretory pathway of non-stored proteins by the liver is discussed further.

Animals↗
PubMed1986

Analysis of growth patterns during gravitropic curvature in roots of Zea mays by use of a computer-based video digitizer.

A computer-based video digitizer system is described which allows automated tracking of markers placed on a plant surface. The system uses customized software to calculate relative growth rates at selected positions along the plant surface and to determine rates of gravitropic curvature based on the changing pattern of distribution of the surface markers. The system was used to study the time course of gravitropic curvature and changes in relative growth rate along the upper and lower surface of horizontally-oriented roots of maize (Zea mays L.). The growing region of the root was found to extend from about 1 mm behind the tip to approximately 6 mm behind the tip. In vertically-oriented roots the relative growth rate was maximal at about 2.5 mm behind the tip and declined smoothly on either side of the maximum. Curvature was initiated approximately 30 min after horizontal orientation with maximal (50 degrees) curvature being attained in 3 h. Analysis of surface extension patterns during the response indicated that curvature results from a reduction in growth rate along both the upper and lower surfaces with stronger reduction along the lower surface.

Computer Systems↗
PubMed1996

Development and evaluation of a new 3-D digitization and computer graphic system to study the anatomic tissue and restoration surfaces.

It is necessary to visualize and reconstruct tissue anatomic surfaces accurately for a variety of oral rehabilitation applications such as surface wear characterization and automated fabrication of dental restorations, accuracy of reproduction of impression and die materials, etc. In this investigation, a 3-D digitization and computer-graphic system was developed for surface characterization. The hardware consists of a profiler assembly for digitization in an MTS biomechanical test system with an artificial mouth, an IBM PS/2 computer model 70 for data processing and a Hewlett-Packard laser printer for hardcopy outputs. The software used includes a commercially available Surfer 3-D graphics package, a public domain data-fitting alignment software and an inhouse Pascal program for intercommunication plus some other limited tasks. Surfaces were digitized before and after rotation by angular displacement, the digital data were interpolated by Surfer to provide a data grid and the surfaces were computer graphically reconstructed: Misaligned surfaces were aligned by the data-fitting alignment software under different choices of parameters. The effect of different interpolation parameters (e.g. grid size, method of interpolation) and extent of rotation on the alignment accuracy was determined. The results indicate that improved alignment accuracy results from optimization of interpolation parameters and minimization of the initial misorientation between the digitized surfaces. The method provides important advantages for surface reconstruction and visualization, such as overlay of sequentially generated surfaces and accurate alignment of pairs of surfaces with small misalignment.

Computer Communication Networks↗
PubMed1977

A hybrid computer system for use in cardiology.

Recent upsurge in the use of physiologic data for medical diagnostic and treatment procedures has prompted the medical profession to use the computer to automate and reduce the time required for data processing. Although the digital computer has traditionally been used to perform these tasks, a hybrid computer (combined analog and digital) has been found to provide many advantages over the digital computer, especially where on-line data processing is concerned. As a result, the Bio-Medical Engineering Center has installed a centrally located hybrid computer system at Ohio State University. One of the applications of this system has been processing cardiac catheterization data. Data is transmitted between the hospital and computer via infrared optics. The data can be analyzed in real time, with the results immediately available to the physician.

Cardiac Catheterization↗
PubMed2002

Digital and biological computing in organizations.

Michael Conrad unveiled many of the fundamental characteristics of biological computing. Underlying the behavioral variability and the adaptability of biological systems are these characteristics, including the ability of biological information processing to exploit quantum features at the atomic level, the powerful 3-D pattern recognition capabilities of macromolecules, the computational efficiency, and the ability to support biological function. Among many other things, Conrad formalized and explicated the underlying principles of biological adaptability, characterized the differences between biological and digital computing in terms of a fundamental tradeoff between adaptability and programmability of information processing, and discussed the challenges of interfacing digital computers and human society. This paper is about the encounter of biological and digital computing. The focus is on the nature of the biological information processing infrastructure of organizations and how it can be extended effectively with digital computing. In order to achieve this goal effectively, however, we need to embed properly digital computing into the information processing aspects of human and social behavior and intelligence, which are fundamentally biological. Conrad's legacy provides a firm, strong, and inspiring foundation for this endeavor.

Adaptation, Physiological↗
PubMed2002

Comparison of conventional and TACT (Tuned Aperture Computed Tomography) digital subtraction radiography in detection of pericrestal bone-gain.

Tuned Aperture Computed Tomography or TACT is a relatively new technique that transforms correlated two-dimensional images into a three-dimensional display. Associating TACT with digital subtraction radiography (TACT-DSR) may enhance its use in the detection of diseases. This study aims to assess observer performance in the task of detecting simulated bone-gain in periodontal defects, comparing conventional and TACT DSR. Buccal, lingual and proximal pericrestal bony defects in a human dry skull were imaged with and without increments of crushed-bone and wax mixtures using standardized vertical bitewing projections, acquired with an intraoral digital receptor in a tomographic X-ray machine. One hundred and twenty pairs of baseline and follow-up images were obtained for each imaging modality. Post-acquisition processing including image-registration, density-correction and subtraction operation were applied to both transmission images and TACT-slices. Eight calibrated observers evaluated the presence or absence of pericrestal bone-gain using a 5-point confidence scale. Details about the location of periodontal defects and the amount of bone-gain for each subtracted image were recorded and used in the statistical analysis. Observer performance and study design factors were analyzed by means of receiver operating characteristic (ROC) curve analysis and ANOVA. Mean values of areas under ROC curves for bone-gain detection performance were 0.82 for conventional DSR and 0.90 for TACT-DSR. TACT-DSR provided statistically superior detection performance of simulated periodontal bone-gain over conventional DSR for tooth-obscured defects (p = 0.001) and for the smallest bone mass (p = 0.024). The findings support TACT-DSR's potential to provide greater sensitivity and technique flexibility in detecting periodontal bone-gain than standard DSR.

Alveolar Bone Loss↗
PubMed2000

Integration of computer-assembled digital images and text data as evidence for the oncological record.

Digitally created visual images of pertinent patient data have been integrated with text information to formulate a visual evaluation and summary sheet (VESS) using computer processing. The VESS incorporates images of a patient's physical appearance, radiological images, pharmacokinetic graphs, and text information into a 1-page document of the patient's condition. Thus, computer processing of digital images and other information helps to refine patient data presentation, analysis, interpretation, and communication. This form of data management is especially valuable in oncological research, where clinical trials demand rapid, ongoing assessment of results and analysis of large amounts of data. The VESS is an effective mechanism for monitoring both the progress of individual patients and the endpoints of the overall clinical trial.

Diagnostic Imaging↗
PubMed1985

[Three dimensional reconstruction of the human left ventricle from multiple cross-sectional echocardiograms: comparison with biplane cineventriculography using Simpson's rule].

A system for reconstructing three-dimensional images of the left ventricle from randomly-recorded multiple short-axis two-dimensional images was developed. This system consisted of a real-time phased array sector scanner, a transducer-locating arm system for registering the spatial coordinates of the images, and a digitizer-computer system for digitizing the endocardial edge to display the reconstruction image and to calculate the left ventricular volume. The clinical applicability of this system was assessed by comparing the calculated left ventricular volumes by this system (3DE) with those measured by cineventriculography (LVG) for 10 patients. For end-diastolic volumes (EDV) determined by 3DE and LVG, the linear regression equation was EDV (LVG) = 1.07 EDV (3 DE)-3.4, SEE = 19.0 ml, r = 0.959. For end-systolic volumes (ESV), it was ESV (LVG) = 1.16 ESV (3 DE)-6.0, SEE = 13.1 ml, r = 0.970, and for stroke volumes (SV), it was SV (LVG) = 0.70 SV (3 DE) + 32.3, SEE = 24.5 ml, r = 0.606. This method was considered applicable to clinical non-invasive measurements of left ventricular volumes. Digitized images were easily processed by a computer, and much informations, such as volumes, shapes and wall motion, were assessable.

Cardiac Volume↗
PubMed1988

Evaluation of a digitizer and computer system designed to analyze articulator-generated occlusal tracings.

Occlusal tracings generated on a Denar fully adjustable articulator were photographed, projected, digitized, and stored in a computer data file. These steps were accomplished with sufficient accuracy for clinical analysis. This study demonstrated that appropriately referenced tracing data can be transferred accurately into a machine-readable form. Studies of pantographic tracings for mandibular movements are facilitated by this convenient and accurate method of handling data.

Dental Articulators↗
PubMed2000

Digital and Computer-Aided Mammography.

Digital mammography uses an electronic system to record an image of the breast that can be stored on a computer instead of on hardcopy films. There are a number of digital mammography technologies under evaluation. The potential advantages of digital mammography include improvements in image contrast, manipulation of the image after it is performed (avoiding repeats for technical problems), elimination of lost films, reduction in film library maintenance costs, and the ability to transmit the images over long distances (telemammography). Challenges and potential problems for digital mammography include a need to prove equivalence in detection and diagnosis with conventional mammography, the high cost of digital mammography equipment, and lagging workstation technology. Computer-aided detection and diagnosis (CAD) uses analysis by a computer program to assist the interpreting physician in identifying abnormal findings on mammograms and in making a benign versus malignant diagnosis of calcifications and masses. Several studies suggest that this technology can reduce the incidence of missed cancers and improve the positive predictive value for biopsies. CAD can be performed after digitization of hardcopy films but is best suited to digitally acquired soft copy images.

Journal Article↗
PubMed1982

Some potential pitfalls associated with the use of computers and microprocessors.

Although digital computers and microprocessors are marvelously sophisticated devices, users are well advised to be aware of certain possible drawbacks associated with their use in the clinical environment. One relates to flawed software, the use of which can generate spurious data upon which subsequent treatment decisions might be based. Another drawback may arise when the computational power of a computer is tapped to generate data that, though mathematically correct, are interpreted in the context of physiologic assumptions that may themselves be faulty. Finally, one must resist the temptation to use computers solely "because they are there." Certain tasks are better left undone, and one must exercise restraint and not plunge into a task simply because a computer is very well suited for that task.

Computers↗
PubMed1985

Low dissipation computing in biological systems.

Biological systems frequently need to solve many computationally hard decision and optimization problems. The solution of these problems by digital computers as presently understood requires exponentially large energy dissipation. This severely restricts the ability of digital computers to attack such problems. We shall show that only polynomial dissipation is required to solve these problems adequately by "physical annealing", as realized in the genetic system, making these problems tractable energetically.

Biometry↗
PubMed2003

Normative values of bone parameters of children and adolescents using digital computer-assisted radiogrammetry (DXR).

PURPOSE: To verify whether estimation of bone mineral density (BMD) using digital X-ray radiogrammetry (DXR) is possible on children and to determine normative values of both such a DXR-BMD estimate and a corresponding metacarpal index (DXR-MCI) on. PATIENTS AND METHODS: In retrospect, X-rays were selected of the hands of 200 healthy Caucasian children (120 boys and 80 girls, aged 4-18 yr). The involved children were selected among a larger group of children submitted to the surgical department of our institute for evaluation of a suspected fracture after an occurred trauma. All children with a verified fracture or a chronic bone-related disease, including bone age retardation or acceleration, were excluded from the study. Furthermore, only conventional X-rays with the same film and capture parameters were included. The images were scanned and analyzed using the Pronosco X-posure system V.2 (Sectra Pronosco, Denmark). DXR-BMD, DXR-MCI, and a porosity index (DXR-PI) were automatically calculated using the midshafts of the metacarpals II-IV. Mean values of DXR-BMD and DXR-MCI were calculated separately for girls and boys in 2-yr intervals. RESULTS: In the present study the system has been demonstrated to be capable of calculating DXR-BMD from conventional X-rays of the hand from children down to approx 6 yr of age. This ability depended somewhat on the diameter and the length of the involved metacarpals. The success rate was higher for large bones than for small bones. The system succeeded in analyzing the images of 110 boys and 68 girls. Values of DXR-BMD were observed to increase with age from 0.40 g/cm2 to 0.62 g/cm2 in the male group and from 0.39 g/cm2 to 0.54 g/cm2 in the female group. Girls aged 11-12 yr had a higher DXR-BMD than did boys, corresponding to the earlier entry to puberty of girls. Standard deviations (SDs) reached values of up to 0.05 g/cm2. DXR-MCI increased with age from 0.36 to 0.47 for boys and from 0.34 to 0.49 for girls with a maximum SD of 0.06. The correlation between DXR-BMD and age was r=0.83 and r=0.84 for boys and girls, respectively. The corresponding correlations for DXR-MCI was lower, with observed correlations of r=0.63 (boys) and r=0.68 (girls), respectively, with p<0.01 in all cases. The DXR-PI did not reveal a significant correlation to age (r=-0.31 and r=0.04. respectively) and showed SDs marginally higher than the calculated mean values. CONCLUSION: The newly available DXR-methodology seems to offer the ability to determine DXR-BMD and DXR-MCI in children starting with a bone age of 6. This possibility may be of special relevance for children suffering from chronic bone diseases that require repeated X-rays of the hand (e.g. to determine bone age). The acquired normative data suggest that the measurements are of clinical value owing to low age-dependent variability (SDs) relative to an observed high increase with age. The clinical value of the porosity index (DXR-PI) remains uncertain and is limited owing to a high inter-individual variability.

Adolescent↗
PubMed1998

Measurements of Contact Angles between an Oil-Water Interface and a Fiber by the ACDPAC Technique.

The ACRPAC (Analysis of Capillary Rise Profile Around a Cylinder) method was modified and extended to measure the contact angles between an oil-water interface and a fiber. Basically, the accurate image of the partial capillary depression profile was acquired and digitized by applying computer digital image processing and analysis techniques. The contact angle was determined by finding the best fit of the theoretically predicted profile, i.e., the curve representing a solution of the Laplace equation of capillarity, to the physically observed liquid-liquid interface. This analysis of the capillary depression profile around a cylinder (ACDPAC) technique was used to measure the contact angles of different water-oil interfaces on cylindrical glass fibers pre-coated with FC725. The wettability of the fiber-water-oil systems with varying oil and aqueous phases was examined. In particular, the wetting effects of a cationic surfactant cetyltrimethylammonium bromide (CTAB) and an anionic surfactant sodium dodecyl sulfate (SDS) dissolved in the aqueous phase were studied by using the ACDPAC technique. The oil phases tested were two dimethyl siloxane liquids, silicone oil A-type and silicone oil B-type. Copyright 1998 Academic Press.

Journal Article↗
PubMedDate not supplied

Caloric testing. 3. Patients with peripheral and central vestibular lesions.

Results of bithermal caloric testing in 83 patients with unilateral peripheral vestibular disease, cerebellopontine angle tumors and vertebrobasilar insufficiency were compared in order to find which response measurements identified the most abnormal responses in each disease category. A laboratory digital computer was used to quantitatively assess each caloric response and a large digital computer was used to statistically compare 110 measurements generated from each caloric test. Of the commonly used response parameters maximum slow component velocity (SVMx) and sum of slow amplitudes (SSA) were most sensitive in each category and duration of response (TDUR) was least sensitive. This order was maintained for the vestibular paresis (VP), directional preponderance (DP) and temperature effect (TE) formulas. The magnitude of DP was significantly correlated with the magnitude of spontaneous vestibular nystagmus and both occurred with approximately the same frequency in peripheral and central disorders. There was no reliable way of separating end-organ from VIII nerve or peripheral from central disorders on the basis of the caloric responses.

Adolescent↗
PubMed1993

An inexpensive computer-based digital imaging teaching file.

Despite a decade and a half of digital imaging in radiology, most radiology teaching files remain film-based. The reasons include the high cost or unavailability of digital acquisition and display devices. In the past few years, a number of excellent exhibits that combine inexpensive microcomputers with radiologic education have been shown at national meetings [1-6]. Unfortunately, many of these methods require esoteric hardware, expensive or proprietary software, or special programming skills. We developed a simple method for creating and disseminating a teaching file of imaging studies obtained with digital techniques.

Computer-Assisted Instruction↗