Quantitation of radio-ligand binding data using a desk-top calculator in the program mode

Quantitation of specific estrogen-binding capacity was facilitated using an inexpensive procedure for the rapid processing of data from radioligand binding measurements from sucrose gradient analyses. Ligand-binding data from each fraction of a gradient were punched into a paper tape in ASCII code and, later, read by a tape reader into an Olivetti Programma 101. Using the total instructional capacity (120 steps) a program was written in symbolic language which describes: (a) the calculation of counting efficiency of the instrument for each fraction, (b) the conversion of counts/minute to disintegrations/minute, (c) the computation of the concentration of [³H]estradiol-17β in each fraction and (d) the summation of the quantity of [³H]estradiol-17β bound by specified regions of the gradient. The program can easily be adapted for use with data generated from separation procedures such as centrifugation, electrophoresis or chromatography in which large number of samples are analysed.     

A modified method for the estimation of pregnanediol, pregnanetriol and seven common 17-ketosteroids in urine by gas-liquid chromatography

A method is described for simultaneous determination of seven common urinary 17-ketosteroids, pregnanediol (5β-pregnane- 3α, 20α-diol) and pregnanetriol (5β-pregnane-3α,17α,20α-triol) by gas-liquid chromatography. The essential steps include hydrolysis of conjugates by an extract from $\text{Helix}$$\text{pomatia}$, use of 5β-cholestan-3α-ol as an internal standard, silylation and gas chromatography using 3% XE-60 as a stationary phase. The chromatograms were clear and the peaks easily identifiable. Laborious purification procedures were not necessary. 5β-pregnane-3α,20α-diol and 5β-pregnane-3α, 17α,20α-triol were measured in 22 adult males and 17 adult females. The subjects were trained hospital personnel, healthy and without medications. The results, in general, were in agreement with those reported by others.     

A simplified strategy for the identification of Gram negative fermenting rods using a desk-top computer

A total of 845 strains of Gram negative, fermenting rods isolated from humans were routinely identified using a desk-top computer. A reduced matrix of 54 taxa x 29 tests was used for a multistep procedure. By an average number of 24 tests, 97–5% of strains reached an identification score of P < 0.9.     

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.     

A concept of a general computer program for the iterative calculation of maximum likelihood estimators with application to qualitative dose response analyses

In this article we describe the construction of a general computer program for the iterative calculation of maximum likelihood estimators. The program is general in the sense that it allows the maximization of any given likelihood function. The user only has to write a subroutine LKLHD, in which the special likelihood function and their first and second derivatives will be calculated. This subroutine is an input parameter of the optimization program. This enables the user to employ one main program for the maximization of various likelihood functions. This advantage will be shown for the evaluation of qualitative dose response relationships (quantal assays: probit-, logit-analysis).     

A rapid gas-liquid chromatographic method for the quantitation of urinary estrone, estradiol-17 , estriol, and pregnanediol throughout pregnancy

A rapid, sensitive and inexpensive method is presented for the determination of urinary estrone (E₁), estradiol-17β (E₂), estriol (E₃), and pregnanediol (P₂) in pregnancy urine. The assay involves enzymatic hydrolysis, ion-exchange chromstography, and final quantitation of the steroids as heptafluorobutyric anhydride derivatives in a gas Chromatograph. Twenty to 30 samples may be prepared for gas-liquid chromatography in one working day. For six samples, the results including gas-liquid chromatography and calculation can be obtained eight hours after receiving the urine specimens thus competing in speed with radioimmunoassays. The method is sensitive enough to allow urines from less than six weeks after the last menstrual period to be quantitated.     

A desk-top computer coupled fermentation system for the study of microbial processes: Description and some applications

The configuration and hardware components of a desk-top computer coupled system for bench-top bioreactors are described. Examples of on-line acquisition of several directly accessible environmental process parameters and computations of directly inaccessible state variables are presented. The system described offers great advantages in experiments for establishing sophisticated control algorithms and for studying the physiological behaviour of microbial populations.     

Natural oils are better than organic solvents for the conversion of soybean sterols to 17-ketosteroids by Mycobacterium fortuitum

Conversion of soybean sterols to 17-ketosteroids by thawed cells of Mycobacterium fortuitum is strongly inhibited by organic solvents. Use of natural oils instead of the solvents leads to enhanced activity, even after 4 h.The authors are with the School of Life Sciences, Devi Ahilya Vishwavidyalaya, Vigyan Bhawan, Khandwa Road Campus, Indore-452 001, India.