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At least 163 records · Page 9Linked to original sources

[Confidence factors-method for estimating the confidence limits of standardized population rate of indirect method].

The standardized rate of indirect method is widely used, but no method of interval estimation for its population rate has been reported. The authors have discussed the standard error of standardized rate of indirect method and suggested that a method using this standard error should be used to determine the confidence limits for the population rate. In this paper, the authors put forward another method (Confidence Factors-Method) which can be easily applied to determine the confidence limits. It gives approximately the same result with the method mentioned above.

Mathematics

[Evaluation of bacterial growth rate by the ATP-bioluminescence method (luciferase assay)--comparison with conventional methods and application to clinical studies].

Bacterial growth rate was evaluated by estimating the increase in ATP content of cultures of bacterial suspensions using luciferase assay, and the method was applied to the estimation of bactericidal activity of serum and anti-bacterial activity of antibiotics. The results obtained were as follows: The bacterial numbers or bacterial growth rate determined by the ATP-Bioluminescence method was in accordance with those by CFU assay and spectrometrical assay by optical density readings. Furthermore this method was confirmed to be non-time-consuming and more simple than other methods. Using this method, anti-bacterial activity of fresh serum was evaluated. The serum suppressed the growth rate of E. coli, Str. fecalis, CBS, Kleb. pneumoniae and Staph. aureus at least for 2 hours. Heat-inactivated serum and absorbed serum with bacteria tended to lose such suppressive effect. Thus the main effective factors seem to be complements and specific antibody. The anti-microbial activity of antibiotics was enhanced by addition of fresh serum to bacterial cultures, and the results were not in accordance with those by the conventional Disc method. Thus the sensitivity test under the influence of fresh serum is recommended in order to know the clinical effect of antibiotics. These results suggest the usefulness of ATP-Bioluminescence method in the clinical laboratory examinations or investigations.

Adenosine Triphosphate

Comparison of Eustachian tube function measured by the microflow method and a new quantitative impedance method.

Eustachian tube function in 25 applicants for flight training was tested during simulated flights using two methods alternately; the integrating microflow method with a stationary pressure chamber, and a new quantitative impedance method in combination with a new mobile pressure chamber. All ears were tested by both methods. The results of the various tests did not differ significantly between methods. The reliability of the measurements was good and almost equal in both methods. Several practical advantages with the new impedance method in combination with the mobile pressure chamber make it preferable.

Acoustic Impedance Tests

[Evaluation of methods to determine the vitamin B6 status of humans. 1. alpha-EGOT: methods and validation].

A semiautomatic method to determine the activation coefficient of the glutamic-oxaloacetic-transaminase in the erythrocytes is described. This method is compared with other methods and possible sources of error are discussed. Colorimetric methods show considerable disadvantages, such as lack of precision or unspecific hydrazone formation. The kinetic tests avoid these problems. This is in part due to the fact that enzyme stimulation by excessive PLP-addition as used in our procedure bears practical and theoretical advantages. Nevertheless, comparison with published data on vitamin B6 status remains difficult because of insufficient standardization of the used methods. To validate our method we performed experiments testing the stability of the samples, short-term physiological changes and influence of the chelating agent EDTA on transamination. Heparinised blood samples can be stored only for one day with changing at 4 degrees C or room temperature. Storing of the erythrocytic suspension at deep-freezing temperature (-18 degrees C) leads to considerable changes of results. When kept under liquid nitrogen there is no change of the alpha-values for at least 45 days. The addition of EDTA to the samples is known to exclude the influences of cations, such as non enzymatic transamination of a direct alteration of the enzyme activity and therefore EDTA should be added to improve standardisation of the method. The described procedure is a fast, reliable and precise way to determine the alpha-EGOT.

Aspartate Aminotransferases

Candidate reference method for determining serum theophylline applied to target-setting in external quality assessment and routine method evaluation.

We present a candidate reference method for the determination of serum theophylline by isotope dilution gas chromatography-mass spectrometry, using extractive alkylation in sample preparation. The maximum method bias was < 1.0%. The mean method imprecision (CV) was 0.63% (range 0.37-0.96%), calculated from the results of six measurements independently performed on 3 days. The maximum total error of the method, including the method bias and 95% confidence interval, was < 2.1%. Investigation of various substances and metabolites for interference proved the specificity of the proposed method. The method was used to evaluate three routine assays by linear regression analysis. Performance of the TDx II (Abbott) was excellent and of the Emit 2000 (Syva) assay was good. The Kodak Ektachem assay showed a high dispersion of results and a pronounced positive bias in the subtherapeutic range.

Evaluation Studies as Topic

[Length method in evaluating right ventricular volume in children with congenital heart disease: a comparison with two dimensional echocardiographic method].

The accuracy and reliability of two-dimensional echocardiographic length method in right ventricular volume measurement were assessed by three-dimensional echocardiographic method in 10 normal children, 10 patients with atrial septal defect, and 10 patients with pulmonary stenosis. Their age and sex were matched. Right ventricular end diastolic, end systolic, mid-systolic volume, and ejection fraction evaluated by length method were correlated very well with the values obtained by three-dimensional echocardiographic method in normal and pulmonary stenosis group (r = 0.71-0.95, P < 0.01). In atrial septal defect group, right ventricular volume obtained by the two methods was correlated well (r = 0.86-0.95, P < 0.01). Although the correlation in right ventricular ejection fraction was lower, it was still significant. The shortening rate of X, Y, Z parameters required by length method were similar in each group: delta Z % > delta X % > delta Y %. We conclude that right ventricular volume and function could be assessed accurately by two-dimensional echocardiographic length method in children with right ventricular volume or pressor overloaded, and that right ventricular systolic pattern is similar in those situations.

Child, Preschool

A comparison of a 30-cluster survey method used in India and a purposive method in the estimation of immunization coverages in Tamil Nadu.

A 30-cluster survey method that is employed for estimating immunization coverages by the Government of India (GOI) was compared with a Purposive method, to investigate whether the likely omission of SC/ST and backward classes in the former would lead to the reporting of higher coverages. The essential difference between the two methods is in the manner in which the first household is selected in the chosen first stage sampling units (villages). With the GOI method, it is often close to the village centre, whereas with the Purposive method it is always in the periphery or in a pocket consisting of SC/ST or backward classes. A concurrent comparison of the two methods in three districts in Tamil Nadu showed no real differences in the coverage with DPT and BCG vaccines. However, the coverage was consistently higher by the GOI method in the case of the Polio vaccine (by 1.5%, 3.1% and 5.3% in the 3 districts), and the Measles vaccine (by 4.8%, 13.3% and 13.9%); the average difference was 3.3% for Polio vaccine (p = 0.08) and 7.3% for Measles vaccine (p = 0.01).

Analysis of Variance

[Critical study of methods of estimation by an enzymatic method of serum triglycerides (author's transl)].

The authors describe a critical study of two entirely enzymatic methods of determination of serum triglycerides which differ mainly by the choice of hydrolytic agents: esterase and hydrolase by the Roche methods, lipase and esterase in the case of the Boehringer method. The estimation of the resulting free glycerol requires 3 sequential enzymatic reactions (glycerol kinase, pyruvate kinase, lactate dehydrogenase, ending by the measurement of the consumed reduced NAD. The study of the kinetics of the analysis in two stages is carried out using standard solutions of glycerol and with human sera of variable concentration; the optimal conditions of the reaction time and temperature are drawn up. The trials of repeatability and reproducibility from day to day were carried out together with evaluation of the precision. The method was compared with Beohringer's method (n = 50) using hydrolysis of alcoholic potash. The authors conclude on the use of the methods studied.

Esterases

Combined gel filtration, biuret/copper method compared with an immunochemical method for urinary protein measurement.

We compared an immunochemical method specific for plasma proteins with a chemical method, in which interfering substances are separated by gel filtration and "total" urinary protein is determined by the biuret reaction followed by reaction of protein-bound copper with diethyldithiocarbamate after a second gel filtration to remove nonprotein-bound copper. More than 250 24-h urine samples were analyzed by each method. There was linear agreement and a correlation of 0.96 between the two methods, but urinary protein values determined by the immunochemical method, especially for patients with multiple myeloma, were lower than by the chemical method.

Chromatography, Gel

Comparative study on two methods for serotyping of Staphylococcus aureus: the Pillet method and the Oeding method. II.-Possible identity between Pillet's antigen 9 and Oeding's antigen h1.

Using two techniques (agglutination and immunoprecipitation), the authors have observed that: -Pillet's strain CK9 and Oeding's strains 670 and 17A are very similar; -antigen 9 is also present in the three strains; the same relation is found in wild strains. Using agglutination and immunoprecipitation, there is a cross reactivity between h1 factor serum, serum 9 and strains CK9, 670 and 17A. A precipitation line involving strain CK9 and serum CK9 is described in the Pillet system. Finally, there is a strong presumption that Oeding's h1 antigen and Pillet's antigen 9 are identical.

Antigens, Bacterial