Area estimation in pharmacokinetic studies using a hand-held programmable calculator

A short program for area analysis in pharmacokinetic studies using the Hewlett-Packard HP41C hand-held programmable calculator is described. Area under the concentration-time curve is calculated firstly within defined time limits and then with extrapolation to infinite time using the slope constant of the terminal phase. Input of concentration-time data is simple and there is no limit on the number of time-concentration co-ordinates which can be entered for area calculation.     

Calculating genetic risk figures using a programmable pocket calculator

Summary In autosomal irregular dominant as well as in sex-linked recessive inheritance, heterozygosity probabilities for up to six or eight pedigree members with unknown genotype can easily be calculated using a programmable pocket calculator. The application of the underlying combinatorial programs is explained by means of two relevant examples. Genetic counsellors without a computer at hand are provided with a simple and accurate method for calculating genetic risk figures taking into account pedigree data, incidence and/or mutation rate, reproductive fitness, as well as penetrance or results of heterozygosity tests of the disease in question.     

Measurement and analysis of gas exchange during exercise using a programmable calculator

Although exercise testing is useful in the diagnosis and management of cardiovascular and pulmonary diseases, a rapid comprehensive method for measurement of ventilation and gas exchange has been limited to expensive complex computer-based systems. We devised a relatively inexpensive, technically simple, and clinically oriented exercise system built around a desktop calculator. This system automatically collects and analyzes data on a breath-by-breath basis. Our calculator system overcomes the potential inaccuracies of gas exchange measurement due to water vapor dilution and mismatching of expired flow and gas concentrations. We found no difference between the calculator-derived minute ventilation, CO2 production, O2 consumption, and respiratory exchange ratio and the values determined from simultaneous mixed expired gas collections in 30 constant-work-rate exercise studies. Both tabular and graphic displays of minute ventilation, CO2 production, O2 consumption, respiratory exchange ratio, heart rate, end-tidal O2 tension, end-tidal CO2 tension, and arterial blood gas value are included for aid in the interpretation of clinical exercise tests.     

Application of a programmable pocket calculator to a single compartment mathematical model of solute kinetics.

A single compartment mathematical model has been applied to kinetics of small solutes (urea and creatinine) in dialysis therapy. The model can be described by two equations requiring iterative solution of calculated values, given several measurable variables. The equations have been programmed onto a Hewlett-Packard 65 pocket calculator and recorded on 3 X 1/2" magnetic strips, facilitating clinical application to dialysis therapy.     

Automatic collection and processing of data from the ultracentrifuge using a programmable desk calculator.

Previous investigators [Trautman, R., Spragg, S. P., and Halsall, H. B. (1969) Anal. Biochem.28, 396–415] have published a detailed protocol for the analysis of sedimentation velocity measurements which is adaptable to data generated by an ultraviolet scanning system. The advent of programmable desk calculators capable of sampling the output of digital measuring devices has made it possible to develop inexpensive and highly convenient systems for collecting and processing scanner data. Basing our approach on the referenced protocol, we have developed algorithms for dealing with real data, that is, data characterized by a relatively high level of noise. The techniques are applieable to both sedimentation equilibrium and sedimentation velocity measurements using the seanning system and multicell rotors. With known concentration dependence, valid estimates of weight-average sedimentation coefficients, diffusion coefficients, and heterogeneity parameters have been obtained for both simulated and actual sedimenting anddiffusing macromolecular solutes. We find, however, that concentration dependence derived internally from a single sedimentation velocity measurement is unreliable.     

The use of a pocket-size, programmable calculator for phenotype tallying of a three-point cross.

A program is presented which permits use of a pocket-size programmable calculator, the HP-65, to tally phenotypes resulting from a three-point cross. For practical purposes the total number recorded for any of the eight possibel phenotypic combinations is unlimited. Although programmed operation of the calculator for tallying purposes is slower than a single purpose instrument designed for tallying, this deficiency is componensated by the computational capability of this instrument.     

Evaluation of centrifugation parameters for density gradient experiments by means of a programmable pocket calculator

A calculation program is proposed suitable for programmable pocket calculators (e.g. HP series) to estimate s_20,w ∫ ω² dt values from density gradient centrifugation data. The program can be applied to linear or exponential density gradients prepared from sucrose or glycerol solutions spun in zonal rotors or swinging bucket rotors. A wide solute concentration range and temperature range is accounted for. Constants for empirical density calculation of glycerol and sucrose solutions concentrated in % (w/v) are estimated. Experiment verification of the program was carried out.     

Transient state isoelectric focusing: computational procedures for digital data processing with a desk-top programmable calculator

Computational procedures (applicable to desk-top programmable calculators) have been described which are useful in the processing of data generated by transient state isoelectric focusing (TRANSIF) experiments. The system allows the calculation of methological parameters such as peak position, peak separation, segmental pH gradient, resolving power, and resolution. “Apparent” physical constants such as the isoelectric point (pI), diffusion coefficient (D), and the slope of the pH-mobility curve ($\text{du}\text{d}\text{(}\text{pH}\text{)}$) of amphoteric molecules can be calculated either by linear interpolation (pI) or by linear regression analysis (D and $\text{du}\text{d}\text{(}\text{pH}\text{)}$). The computing programs are also capable of performing operations such as smoothing of raw data, conversion to absorbance, baseline detection and correction, and calculation of the higher statistical moments of Gaussian, bi-Gaussian, and asymmetric peak shapes. Moment analysis is carried out by direct statistical procedures, curve simulation, and slope detection methods. The above computational procedures provide a useful and necessary adjunct to the scanning isoelectric focusing assembly which is coupled to a digital data acquisition and recording system.     

An off-line data processing system for biochemistry profiling based on a 2K programmable calculator.

An off-line data processing system based on a Hewlett Packard 2K programmable calculator to be used with a biochemistry profiling system is described. The program is in two sections. A Data Acquisition phase calculates results from Auto Analyser II peak heights after corrections for drift and stores them on magnetic tape cassettes. Quality control statistics are produced. A Reporting phase types the profile results on self-adhesive pre-printed labels to be attached to the test-request form and also prepares a laboratory record sheet. The system is routinely used to process up to 2000 peak heights per day. Non-profile heights may also be read using this program.     

Gentamicin: use of a programmable calculator to determine dosages from pharmacokinetic data for individual patients.

Gentamicin, an antibiotic frequently used in the treatment of gram-negative infections, has a narrow therapeutic index, so the correct prediction of its serum concentrations is important. Recent studies have emphasized the dubious accuracy of commonly used formulas, and computer programs that provide pharmacokinetic data for individual patients from multiple blood samples have helped to adjust dosages but are expensive. This study tested the applicability of a method using only two blood samples and a programmable calculator to estimate pharmacokinetic parameters for individual patients and adjust dosages to aim at peak and trough serum levels of 6 and 1 micrograms/ml respectively. In the 48 patients with normal renal function this method produced peak serum concentrations of gentamicin within 1 microgram/ml of the desired level in 22 (46%) and therapeutic peak concentrations (between 4 and 10 micrograms/ml) in all the patients. In 10 patients with renal failure it produced peak serum concentrations within 1 microgram/ml of the desired value in 4 and therapeutic serum concentrations in 7. Two patients had peak concentrations below 4 micrograms/ml and one had a peak concentration above 10 micrograms/ml. Two of the three patients whose serum levels were outside the therapeutic range had unstable renal insufficiency. Thus, patients with renal insufficiency need continued monitoring of the serum level of gentamicin, particularly when their renal function is changing.     

A technique for joint center analysis using a stored program calculator

For a long time in the study of joint kinematics, the instant center of rotation in plane motion was obtained through graphic drawings. Since then the study of joint kinematics has become three-dimensional involving the use of computers. For this paper a stored-program calculator has been used as it is a precise instrument and several films can be used even if their positions are very close to one another.

A movement is never perfectly plane, it was important to define a coefficient (in percentage) to qualify the more or less plane character of a movement.

We believe that an analytical location is a better way than using graphic drawings of I.C.R.:

1. (1) to smooth the raw coordinates;

2. (2) to calculate the plane motion coefficient in order to eliminate an X-Ray picture of a whole series of pictures for lack of plane character;

3. (3) to define in the results an error rectangle whose dimensions are linked to errors in the observation and then to pick out among the points of a body those with the smallest risk for error.

To probe this method the two radio-ulnaris joints have been studied. At present studies are being carried on to compare the I.C.R.'s behaviour of the lumbar spine during a motion of lateral inflexion both in the case of normal people and people with scoliosis.     

Two simple programs for the analysis of data from enzyme-linked immunosorbent (ELISA) assays on a programmable desk-top calculator

We have designed two programs for use with an inexpensive programmable calculator which rapidly and accurately convert raw data generated from enzyme-linked immunosorbent assays directly into antigen concentration. The first program computes and compares effective doses (ED₅₀)'s between a standard and each unknown sample assayed. The ED₅₀ from the unknown sample is then multiplied by a concentration factor which yields the unknown concentration. The second program linearizes the sigmoidal enzyme-linked immunosorbent assay titration curve using a logit-log transformation of the data in order to compute unknown concentration values. Both programs employ stringent limit conditions to decrease “nonsense” calculations. Data are then processed by a least-squares best-fit linear regression analysis.     

Biolistic transfection of neuronal cultures using a hand-held gene gun

Biolistic transfection is a technique in which subcellular-sized particles coated with DNA are accelerated to high velocity to propel them into cells. This method is applicable to tissues, cells and organelles, and can be used for both in vitro and in vivo transformations; with the right equipment, it is simple, rapid and efficient. Here we provide a detailed protocol for biolistic transfection of plasmids into cultured human embryonic kidney (HEK) 293 cells and organotypic brain slices using a hand-held gene gun. There are three major steps: (i) coating microcarriers with DNA, (ii) transferring the microcarriers into a cartridge to make a 'bullet', and (iii) firing the DNA-coated microcarriers into cells using a pulse of helium gas. The method can be readily adapted to other cell types and tissues. The protocol can be completed in 1-2 h.     

Application of a programmable calculator in data fitting according to one and two compartment open models in clinical pharmacokinetics

The plasma or blood concentration profiles are fitted by single or two compartment open models using log-linear regression analyses. For two compartment models, “feathering” is performed at 95% equilibration time obtained from raw pharmacokinetic data. The equations have been programmed onto a Texas Instrument SR 52 pocket calculator and recorded on 8.5 × 1.7 cm magnetic strips, facilitating drug dosage regimen calculations through individual patient titrations in a clinical setting.     

A programmable calculator program for rapid logarithmic extrapolation, and calculation of mean transit time from an indicator-dilution curve.

Reconstruction of the primary indicator-dilution curve is accomplished by exponential curve-fit from a set of points obtained on the downslope of the curve. Curve-fit is simplified by requiring entry of indicator concentrations (Yi) only, where time increments (Xi) are made self-generating in the program. Similarly, calculation of mean transit time requires only the entries of Yi. Stored values supply the needed quantities for calculations of cardiac output and the central blood volume as defined by the injection and the sampling sites. The Texas Instrument TR 52 model hand-held programmable calculator is utilized in this program but it should be adaptable to other programmable calculators. The present program provides a procedure for rapid reconstruction of the primary indicator-dilution curve, and hence calculations of cardiac output, mean transit time and central blood volume.