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An automated dosimetry data-acquisition and analysis system at the LAMPF pion therapy facility.

An automated data-acquisition and analysis system has been developed for dosimetry measurements on the pion therapy beam at the Clinton P. Anderson Meson Physics Facility Biomedical Channel in Los Alamos using a PDP-11/45 computer and CAMAC interface. Initialization, test, and monitor programs allow the user to set the physical limits of scanner travel, test the data lines, calibrate the analog signals for the scanner position, and monitor the analog versus digital values of the scanner position during operation. Data-acquisition programs scan beams in one, two, and three dimensions. Many options are available to the user in selecting the scan parameters and in changing some of these parameters during scanning. Data-analysis programs provide reproduction of stored data, comparison of linear scans, beam profiles along any line of a planar or volume scan, and isodose distributions from any planar scan or from any planar scan or from any plane of a volume scan. Other programs summarize stored data files and search for specific data according to the user's instruments.

Computers↗

Nomogram for dosing warfarin at steady state.

The predictive performance of a nomogram for dosing warfarin was compared with that of a computer program. The nomogram and the computer program were developed from the log-linear model describing warfarin pharmacodynamics at steady state. The nomogram's dose-response curves were generated by using previously reported pharmacodynamic and pharmacokinetic values for an outpatient population receiving warfarin. The series of dose-response curves were plotted by altering the pharmacodynamic values over a range of 3 standard deviations. The ability of the nomogram to predict the steady-state prothrombin time ratio (PTR) after an adjustment in the dosage of warfarin was evaluated, and the results were compared with those of a commercially available program involving Bayesian regression. Data for 65 outpatients were evaluated. The mean +/- S.D. nomogram-predicted, computer-predicted, and measured PTRs were 1.63 +/- 0.27, 1.64 +/- 0.24, and 1.66 +/- 0.23, respectively. The mean prediction errors for the nomogram and the computer program were -0.037 and -0.026, respectively, and the mean percent absolute prediction errors were 11.6% and 11.0%, respectively. Neither method was biased, and differences between the results for the two methods were not significant. The predictive performance of the warfarin dosing nomogram was comparable to that of the computer program.

Bayes Theorem↗

Practice variation and length of stay in alcohol and drug detoxification centers.

Admissions to 20 publicly funded alcohol and drug detoxification centers in Massachusetts were examined to identify program and patient variables that influenced length of stay. The last admission during fiscal year 1996 was abstracted for patients 18 years of age and older seeking alcohol, cocaine, or heroin detoxification (n=21,311; 29% women). A hierarchical generalized linear model examined the effects of patient and program characteristics on variation in length of stay and tested case-mix adjustments. Program size had the most influence on mean adjusted length of stay; stays were more than 40% longer in detoxification centers with 35 or more beds (7.69 days) than in centers with less than 35 beds (5.42 days). The study highlights the contribution of program size to treatment processes and suggests the need for more attention to program attributes in studies of patient outcomes and treatment processes.

Adolescent↗

Microcomputer experience in analysis of flow cytometric DNA distributions.

The program described analyses DNA histograms obtained in flow cytometry using the Gaussians method. The program is written in BASIC to run on a low-cost microcomputer. It utilizes a simple strategy to obtain good estimates of the parameters required for reducing the problem to a task solvable with linear least-squares methods. Features of the program are flexibility, since it is possible to choose different options for parametrization and spacing of Gaussians, and the fact that the operator is not required to provide interactive inspection or inputting parameter values. The capability and velocity of the program, in all its options, are tested and compared on a series of different (not computer-simulated) histograms obtained in our flow cytometry laboratory. Our results suggest that a fresh approach to parametrization may be useful.

Biometry↗

PEDA: a microcomputer program for parameter estimation and dosage adjustment in clinical practice.

PEDA, an integrated program in BASIC for implementation on microcomputers, has been developed for use in clinical practice to assist dosage adjustment for individual patients. A parameter optimization for individual patients is based on the principle of Bayes' theory and Maximum Likelihood Estimation, and utilizes a prior information on the distribution of population pharmacokinetic parameters, means and variances, as well as serum drug concentrations. The program can accommodate a one-compartment open linear model and a non-linear model at steady state (Michaelis-Menten model) and handle both uniform and non-uniform multiple dosage regimens mostly arising from clinical settings. Clinical examples which demonstrate the ability and the flexibility of the program are provided. The program may also be used as an aid for instruction in clinical pharmacokinetics.

Adult↗

A computer-based AIDS education program for nursing students.

A multidisciplinary team has developed a computer-based software program for educating nursing students and other college students about six sexually transmitted diseases (STDs). The program for educating about Acquired Immune Deficiency Syndrome (AIDS) is the first of the six "Smartbooks" to be completed, using the Hypercard Expert System shell on the Macintosh computer. Information is organized within a framework known as a concept map, and the student user progresses through the program in a self-directed way by "clicking" on the portion of the concept map that is of interest. Thus, the knowledge base can be accessed in many different ways, and is not restricted to a linear format. Comparative quantitative analysis using a control program shows consistently better student retention of information presented within the program that features concept maps. Qualitative results indicate that students find the conceptually-arranged knowledge base implicitly easy to understand, "fun" to use, and interesting to explore. Educational theory suggests that the success of such a format may be related to the schematic nature of memory.

Acquired Immunodeficiency Syndrome↗

[Determination of naoning pian by multi-wavelength linear regression method].

Assay of naoning pian was reported by multi-wavelength linear regression method in this paper. The program was edited by BASIC. The recoveries and RSD of pyramidon and caffeine were 98.03%-100.9%, 1.0% and 97.77%-99.39%, 0.61%, respectively. This method could be used for the determination of two components in naoning pian without separation. The method was simple, rapid, and results were satisfactory.

Analgesics, Non-Narcotic↗

A computer program for parallel line bioassays.

PARLIN is a program for the statistical analysis of biological assays that are either completely randomized, or in randomized blocks, in which the regression on log dose is linear with a constant variance per response. An earlier program (McArthur et al., J. Pharmacol. Exp. Ther. 153: 573-580, 1966) has been completely rewritten, improved and extended in its facilities. PARLIN, written in FORTRAN IV, will handle up to 99 test preparations, up to 100 doses in all, and up to 50 responses per dose. It is designed with special attention to simplicity for routine use, versatility of facilities and output immediately available for all forms of reporting results. A wide choice of transformations of response is available. The output reproduces the data for verification and tabulates potency estimates with limits at probabilities .95, .99; optional output includes an analysis of variance, information on validity, values of residuals and a rough plot of the dose-response relation.

Analysis of Variance↗

Multiple-dose nonlinear regression analysis program for the microcomputer.

An adaptation of a previously published program for nonlinear regression analysis of serum drug concentrations which can utilize data obtained during multiple-dose administration is described. Specific programs have been developed for aminoglycosides, digoxin, and theophylline. The programs provide initial parameter estimates (for a one-compartment linear model) for each drug based on mean population parameters and refined estimates based on observed concentration data. Clinical examples which demonstrate the flexibility of these programs are provided. The programs may also be employed for fitting data for any drug that can be adequately described by a one-compartment linear model.

Adult↗

Dynamic simulation of pharmacokinetic systems using the electrical circuit analysis program SPICE2.

The electrical circuit simulation program SPICE2 is used to perform computer simulations of linear and non-linear pharmacokinetic systems. This is achieved by applying novel network thermodynamic principles which make use of the analogy between the conservation laws of chemical reactions and mass transport and Kirchoff's laws of current and voltage balance for electrical circuits. A simple description of program input for general pharmacokinetic simulation as well as simulation of complex pharmacokinetic and physiologic phenomena such as single and multiple divided daily dosing, Michaelis--Menten kinetics, gastric emptying cycle, drug resorption and linear and non-linear drug protein binding is provided. Drug concentrations or amounts in different compartments are graphically obtained or tabulated as time functions. The economy of time and effort afforded by this program is illustrated by simulating the metabolism and accumulation kinetics of salicylic acid on single and repeated divided dosing. The advantages of SPICE2 over other available simulation packages and its educational value as a teaching and research tool are discussed.

Computers↗

Effects of extra immunization efforts on routine immunization at district level in Pakistan.

A study was made of the effects of extra immunization activities on routine immunization coverage at district level in Pakistan in a secondary analysis of data from UNICEF and the Pakistan national census. Linear regression analysis was made on data from 107 districts to estimate the effects of extra immunization efforts in the national neonatal tetanus programme on the coverage rate of the third dose of diphtheria-pertussis-tetanus (DPT3) after controlling for other potential confounding factors. The districts that implemented extra national neonatal tetanus immunization were at risk of having lower routine DPT3 coverage than those that did not. Additional immunization efforts, without additional resources, may reduce the effect of the routine Expanded Programme on Immunization.

Cluster Analysis↗

Sexual risk attitudes and intentions of youth aged 12-14 years: survey comparisons of parent-teen prevention and control groups.

In this study, the authors compared differences in sexual risk attitudes and intentions for three groups of youth (experimental program, n = 90; attention control, n = 80; and nonparticipant control, n = 634) aged 12-14 years. Two student groups participated with their parents in programs focused on strengthening family interaction and prevention of sexual risks, HIV, and adolescent pregnancy. Surveys assessed students' attitudes and intentions regarding early sexual and other health-risk behaviors, family interactions, and perceived parental disapproval of risk behaviors. The authors used general linear modeling to compare results. The experimental prevention program differentiated the total scores of the 3 groups (p < .05). A similar result was obtained for student intentions to avoid sex (p < .01). Pairwise comparisons showed the experimental program group scored higher than the nonparticipant group on total scores (p < .01) and on students' intention to avoid sex (p < .01). The results suggest this novel educational program involving both parents and students offers a promising approach to HIV and teen pregnancy prevention.

Adolescent↗

Mixed-function oxygenation of the lower fatty acyl residues. II. The kinetics of microsomal omega- and (omega - 1)-hydroxylation of N-(4-chlorophenyl)propanamide.

Investigation of the kinetics of microsomal omega- and (omega - 1)-hydroxylation of 4,'-chloropropionanilide with rabbit liver microsomes revealed normal Michaelis-Menten behavior for that form of cytochrome P-450 which catalyzes omega-hydroxylation, and deviation from Michaelis-Menten behavior for the form(s) of the hemoprotein that catalyze(s) (omega - 1)-hydroxylation. This is deduced from linear Lineweaver-Burk plots of the kinetic data from omega-hydroxylation and from concavely curved downward plots of the kinetic data from (omega - 1)-hydroxylation. Evaluation of the apparent kinetic constants for (omega - 1)-hydroxylation was achieved by means of a computer program developed on the basis of non-linear regression analysis. The effect of inducers of microsomal oxygenases, such as phenobarbital and 3-methylcholanthrene, and of modifiers of microsomal enzyme activities, such as NADH, EDTA, nicotinamide, and SKF 525-A on the kinetics of omega- and (omega - 1)-hydroxylation has been studied. The two types of hydroxylation were affected differently, and different concentrations of the modifiers affected the hydroxylation pattern differently.

Anilides↗

Malnourished children treated in day-hospital or outpatient clinics exhibit linear catch-up and normal body composition.

The nutritional programming hypothesis proposes that early life malnutrition is related to an increase in body fat later in life. Brazilian boys and girls (n = 94; 4-14 y old) were studied. Malnourished children treated in a Nutrition Recovery Center, were followed up and divided into 2 groups: the Outpatient group (recovered after outpatient care, n = 28), and the Day-hospital group (recovered after day-hospital care, n = 38). They were compared with a Control group (healthy individuals without intervention, n = 28). Nutritional recovery was confirmed by anthropometry. Body composition was evaluated by dual-energy X-ray absorptiometry. Both recovered groups had a greater increase in height-for-age Z-scores than in weight-for-age Z-scores after treatment (P < 0.03). Body fat mass (kg) and the percentage of body fat were significantly lower in recovered groups of girls and boys compared with controls. Among boys, lean mass/height (kg/cm), fat-free mass (kg) and the fat-free mass index (kg/m(2)) were significantly lower in the Outpatient and Day-hospital groups than in Controls, but girls did not differ. Bone mineral content (BMC)/height (g/cm) did not differ between the recovered girls and the girls in the Control group (P < 0.15) or between the boys in the Day-hospital group and those in the Control group (P = 0.06). The Outpatient boys group had lower BMC/height than boys in the Control group (P = 0.02). This study demonstrates that when malnourished children receive adequate treatment, linear catch-up growth occurs and is followed by appropriate gain in lean body mass and BMC.

Adipose Tissue↗

Easy and practical utilization of CONSAM for simulation, analysis, and optimization of complex dosing regimens.

Complex dosing regimens simulated in the literature using a universal dosing regimen were calculated with a general dosing program developed using the program CONSAM. The program provides a rapid method of calculating nonuniform dosing regimens for up to n = 3 compartments for any linear model. Subject data can also be curve fitted with the program to obtain individual subject estimates to allow for dosage optimization, which is important in a clinical setting. Examples are presented to show the use of the program in optimizing a theophylline regimen, as well as estimation of a new parameter, Cuneq(T), which is defined as the average non-steady-state drug concentration at time t for a drug with an irregular dosing interval.

Computer Simulation↗

Helicobacter pylori specific immune response induced by conservative flagellin linear B-cell epitope.

AIM: To testify the immunogenicity of a conservative B-cell linear epitope of Helicobacter pylori (H pylori) flagellin A. METHODS: Different programs were used to analyze the secondary structure, molecular hydropathy, and surface accessibility of H pylori flagellin A. Linear B-cell epitopes were estimated based on the structural and physiochemical information. Analysis of residue divergence was proposed to screen a conservative linear epitope. The 29-peptide (Pep29mer) synthesized by chemical method, including the predicted conservative B-cell epitope and a known K2d compatible T-cell epitope, was used to immunize mice, and then H pylori-specific antibodies were detected by ELISA. RESULTS: Based on the analyses of divergent amino acid residues, structural and physiochemical characteristics, it was strongly suggested that the short fragment NDSDGR was the core of a conservative linear epitope in flagellin A. Animals immunized by Pep29mer acquired efficient immune response. In detail, serum H pylori-specific IgA and IgG1 increased significantly in immunized group, while IgG2a only had an insignificant change. H pylori-specific IgA in gastrointestinal flushing fluid also increased significantly. CONCLUSION: The conservative short fragment NDSDGR is the core of a linear B-cell epitope of flagellin A.

Amino Acid Sequence↗

A Pascal program for weighted least squares regression on a microcomputer.

Weighted least-squares regression has been programmed in Pascal for a microcomputer. A double precision Pascal compiler and the Motorola 6809 assembler produce a fast machine-code program occupying 22,000 bytes of memory when appended to the Pascal run-time module. Large data sets fit in the remaining memory. A regression with 72 observations and 24 parameters runs in 7 min, excluding optional print out of large matrices. The maximum dimensions of the design matrix, X, can be altered by modifying two Pascal constants. Minor changes to the Pascal source program will make it compatible with other Pascal compilers. The program optionally orthogonalises the X matrix to detect linearly-dependent columns in X, and/or generate orthogonal parameter estimates. After orthogonalizing X and fitting the model, the parameter estimates for the original X can be retrieved by the program. Regressions on a repeatedly reduced model are performed through elimination of columns in X until the minimum adequate model is obtained.

Computers↗