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An algorithm and a program have been developed which enable optimal alignments of biological sequences on an 8-bit microcomputer. The compiled program can process sequences up to 1000 residues on a Commodore 64. Since this program was written originally in the BASIC language, it may readily be adapted to other microcomputers with small changes.
A microcomputer program which locates tRNA genes within long DNA sequences is described. The search is performed either by identifying tRNA-like secondary structures or by locating eukaryotic RNA polymerase III promoter consensus sequences. The program is also useful in finding inverted repeats allowing the formation of stem-loop secondary structures in tRNA. The program has been developed in BASIC and 6502 Assembler and runs on the Apple II plus and IIe microcomputers. The execution is quite fast; all the operations are carried out in 1-90 s, depending on the required task and on the sequence length.
A simple microcomputer package is described to make the theoretical analysis of protein sequences. Several methods designed to compare two sequences, to model proteolytic reactions and to predict the secondary structure, the hydrophobic/hydrophilic regions and the potential antigenic sites of proteins have been included in an Apple II microcomputer software. The package comprises 21 programs as well as the secondary structure database of Kabsch and Sander (1983).
The most common types of nucleotide sequence data analyses and handling can be done more conveniently and inexpensively on microcomputers than on large time-sharing systems. We present a package of computer programs for the analysis of DNA and RNA sequence data which overcomes many of the limitations imposed by microcomputers, while offering most of the features of programs commonly available on large computers, including sequence numbering and translation, restriction site and homology searches with dot-matrix plots, nucleotide distribution analysis, and graphic display of data. Most of the programs were written in Standard Pascal (on an Apple II computer) to facilitate portability to other micro-, mini-, and and mainframe computers.
This paper illustrates how a microcomputer spreadsheet package can be used by epidemiologists to facilitate the computation of multiple logistic regression (MLR) probabilities, as well as odds ratios and associated confidence intervals, given the coefficients of the MLR model. By formatting a spreadsheet, data entry is greatly simplified, and computations are accomplished without any arithmetic manipulations on the part of the user. This approach makes it feasible for clerical support staff to assist in the computation of seemingly complex expressions. The increasing availability of microcomputers in clinical and research settings suggests that numerous analytic applications are amenable to this approach, thereby decreasing reliance on mainframe computers and desk-top calculators.
A system is described for coding of anatomic--including forensic--pathologic diagnoses from necropsy cases using a microcomputer. The SNOMED software from the College of American Pathologists is utilized. RAM-disk software is employed to enhance the speed of operation of the system. The microcomputer can be operated by clerical staff versed in medical terminology. Speed of entry and retrieval, with minimal manual interaction, is an important aspect of operation. Equipment and storage costs are minimal.
Potential uses for microcomputers in medical education include evaluation of students and residents. A computer program developed at the University of Pennsylvania School of Medicine and the Children's Hospital of Philadelphia presents simulated patient cases and then scores participants' clinical problem-solving in the cases by comparing their performances with those of five faculty members. In the study reported here, the authors investigated the validity and reliability of this evaluation system. Total scores were significantly different among faculty members, residents, and third-year students on only the most difficult of the three cases included in the study. Performance was not related to the user's general analytic ability or to locus of control. This result suggested there is not a "type" of person who is better at medical problem-solving on a microcomputer. A prophecy formula was used to determine that nine cases would be needed to achieve an adequate level of reliability in measuring the ability of a student or a resident. Implications of selecting a battery of cases for the system are discussed.
A model for a microcomputer database to aid a school's efforts to recruit and retain students is presented. The model is based upon a working system developed by the author at the University of Colorado Health Sciences Center. The article discusses data needs for adequate records of the recruitment and retention efforts, especially those concerning minority students, and how these records can be used to administer and evaluate programs. The model provides a framework for microcomputer data files, record fields, relationships, and system development and maintenance considerations.
An algorithm for solving first-order non-recycling compartment models is described. Given the initial amounts of a radioactive material in each compartment and the fundamental transfer rate constants between each compartment, the algorithm gives both the amount of material remaining at any time t and the integrated number of transformations that would occur up to time t. The method is analytical, and consequently, is ideally suited for implementation on a microcomputer. For a typical microcomputer with 64 kilobytes of random access memory, a model containing up to 100 compartments, with any number of interconnecting translocation routes, can be solved in a few seconds; providing that no recycling occurs. An example computer program, written in 30 lines of Microsoft BASIC, is included in an appendix to demonstrate the use of the algorithm. A detailed description is included to show how the algorithm is modified to satisfy the requirements commonly encountered in compartment modelling, for example, continuous intake, partitioning of activity, and transformations from radioactive progeny. Although the algorithm does not solve models involving recycling, it is often possible to represent such cases by a non-recycling model which is mathematically equivalent.
A general algorithm for solving first-order compartmental models including recycling systems has been developed and its implementation on a microcomputer is described. Matrix algebra is used to obtain for any compartmental model an analytical solution, which is expressed as the exponential of a matrix of rate constants. A special technique is used in the algorithm to enable this exponential to be evaluated with a rapidly converging series. Truncation errors incurred in this process are estimated automatically. Thus, in an extreme case, where these errors may be significant, the appropriate action can be taken. Given a particular model, the user enters the model parameters into a rate matrix according to a simple rule. The algorithm then uses this matrix to solve the model, and thus no specialized mathematical knowledge is needed. The algorithm is given in a short BASIC program (60 lines) listed in an appendix. No additional software is required. By running this program on a standard microcomputer, the user can solve models of any complexity: those up to 15 compartments in seconds and those up to 30 compartments within a minute. The algorithm is thus ideally suited to solve kinetic models describing the transport of radionuclides in the environment or the translocation of elements in biological systems such as the metabolic models recommended by the International Commission on Radiological Protection (ICRP). Given the initial amount of material in each compartment at time t = 0, together with its radioactive decay constant, the algorithm gives both the amount in each compartment at any future time t and the number of disintegrations that will have occurred in each compartment up to time t. The computer program, shown in an appendix, could easily be used to calculate disintegrations over any time interval of interest, or to predict the quantities or fractions of an intake expected to be present in any in vivo or excretion compartments of interest. Thus, the algorithm can be useful in both the design and conduct of bioassay and internal dose assessment procedures.
This paper presents a microcomputer-based technique that accurately quantifies volumes from computed tomographic (CT) scans of irregularly shaped objects as well as displaying 3-D reconstructions. The method uses standard CT film, allowing analysis of previous or outside CT studies. The planimetry method showed less than 5% error in measuring irregular 2-D areas larger than 6 mm2. The method is demonstrated to be significantly more accurate than spherical, ellipsoid, or rectangular geometric models in quantifying object volume by CT (P less than .001). With a single gantry angle, planimetry showed a two standard deviation error under 10% in measuring the volume of irregular objects compared with an error over 30% for ellipsoid models. The inaccuracy of the spherical model (80% error) and the rectangular prism model (192% error) renders them impractical to provide quantitative object volume. Microcomputer planimetry provides an accurate and versatile means to measure the volume and produce 3-D reconstructions of objects scanned with CT, and it has potential application in quantifying tumor response with CT and magnetic resonance imaging.
Recent endeavors have applied microcomputers and interactive laser/optical videodisks to create simulations of psychodynamic processes. This paper briefly describes the technical aspects of microcomputers and videodisks, explores attributes and drawbacks of these simulation systems, and outlines future directions toward the ideal psychodynamic simulation.
From maintaining patient records to analyzing data to documenting time of professional efforts, microcomputers provide specific benefits to today's health care professional. Recent advances in microprocessor technology has made a new generation of personal computers feasible and affordable. The use of these microcomputers in clinical management, education, and data manipulation promises to offer unlimited potential for improving health care delivery.
Current techniques for imaging chest deformity are limited to two-dimensional representations, and clinical testing for lung volume measurements are based on pulmonary function studies that are effort-dependent. The authors evaluated spine deformity and lung volume by using a new three-dimensional microcomputer imaging technique. Results from preoperative and postoperative chest computed tomograms underwent boundary detection by expert human observers. Data were then processed by polygon surface tiling to create three-dimensional color images of the spine and lungs for display. This computer technique allowed: 1) visualization of the anatomic relationships from any angle, 2) assessment of spinal deformity in relation to lung volume, and 3) measurement of individual lung volumes. Three-dimensional microcomputer imaging is a useful technique in objectively measuring lung volume and assessing postoperative changes.
A retrospective study of patients receiving tobramycin compared the accuracy of predictions of actual trough serum concentrations using two commercially available microcomputer software programs. Twelve patients met the study criteria of intravenous tobramycin treatment for more than 10 days with serum concentration monitoring within the first 5 days and after 10 days of therapy. No patients received dialysis. Twenty-five serum concentrations were compared. Predictions within 0.2 microgram/ml were considered clinically "exact." No significant differences were found by chi-square analysis for any of the four possible choices (p less than 0.3). One of the programs, distributed by Dista Pharmaceuticals, offers a one-compartment model, a two-compartment model, and a two-compartment prenephrotoxic option. SIMKIN, a program marketed by Medical Engineering, Inc., uses a two-compartment model. Overall, the predictions errors were small, but occasionally were clinically significant. Further evaluation of microcomputer programs for therapeutic drug monitoring is necessary to document their impact on predicting drug efficacy and toxicity.
1. The literature relating to the effects of benzodiazepines in general, and temazepam in particular, on human psychomotor performance as assessed using microcomputer-based testing batteries is surveyed. 2. The adverse effects of central nervous system depressants on performance is an important mediocolegal issue and frequently comes into question in on-the-road and on-the-job accidents. The use of microcomputer-based testing batteries allows for performance evaluation both in the laboratory and at-the-scene, as well as providing the opportunity to model a large number of different behaviours required in routine yet complex psychomotor tasks. 3. The conclusions in general are: (1) The benzodiazepines as a class of drugs impair both cognitive and motor performance. These effects are often subtle when low doses are involved or when testing occurs the morning following evening administration of the medication. (2) No single psychomotor task adequately simulates complex daily tasks such as automobile driving. A battery of tests that evaluates a number of the components of such tasks is necessary to determine adequately the full range of effects of these medications.
A microcomputer based patient data file and analysis system is both feasible and useful. One such system is described in this paper. The advantages and disadvantages of the system are discussed. It may be used in many patient-related specialties and will enable practitioners not only to file their data but more importantly to analyse it so that they can improve their performance and cost-effectiveness. It is the author's belief that few realize the potential of the microcomputer in clinical practice and many are put off computing and computerized recording and data analysis because of the size and the difficulties that most experience with larger minicomputer-based facilities.
Steady state exercise is widely used for psychophysiological studies in which a constant heart rate at a predetermined level is desired. We have developed a microcomputer servo-controlled bicycle ergometer system that can be used for administering steady state exercise. Fourteen healthy male subjects, with a wide range of fitness levels (measured by VO2max) were exercised to either a fixed workload (130 watts) or a predetermined heart rate level (servo-heart rate) of 122 bpm (i.e., 65% of maximum calculated heart rate for the sample). Servo-heart rate was implemented using a feedback loop that automatically adjusted workload to compensate for immediate variations in heart rate, resulting in a more consistent heart rate. Heart rate varied from the predetermined value by 17 bpm during fixed workload but only 3 bpm during servo-heart rate (p less than .05). Therefore, by using the microcomputer servo-controlled bicycle ergometer, heart rate was maintained at a predetermined level regardless of the subject's fitness level. VO2max and workload during servo-heart rate were significantly correlated (r = .85, p less than .05). Therefore, the workload necessary to maintain heart rate at a constant level may provide an approximate index of aerobic fitness level.