Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “methods”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources
PubMed1997

[Detection of mycobacteria using the Bactec radiometry method and standard culture methods].

For parallel detection of mycobacteria by the radiometric method using a Bactec 460 TB apparatus and by the standard cultivation method 5383 specimens of pathological material from patients of in-patient TB departments (90%) and other health facilities (10%) were examined. 492 samples were positive. By the radiometric method alone 114 samples were positive and by cultivation only 15 samples. The mean period of detection was 12.9 days for the Bactec method, for the cultivation method 32.4 days. For the Bactec system 0.4 ml inoculum was used and one cultivation vessel, for the cultivation 0.4-0.6 ml inoculum and two egg media per sample. Of 15 samples positive on cultivation only, rarely colonies were obtained after 6-9 weeks' incubation.

Bacteriological Techniques↗
PubMedDate not supplied

Assessment of percent body fat content in young and middle aged men: skinfold method v/s girth method.

Percent body fat content was found in apparently normal healthy 30 young (17-20 Yrs.) and 30 middle aged men (30-46 Yrs.) by measuring the skinfold and girth. None of the subjects were athletes or did regular physical exercise. Body density was calculated using mean of the four skinfold measurements as per the equations advocated by Durnin and Womersley, while percent body fat content was calculated from the body density by the Siri's equation. The mean % body fat content by this method in young men was 15.87 +/- 3.85% and in middle aged men was 24.75 +/- 3.55%. Ten percent of the young subjects and 90% of the middle aged subjects were found to be obese. Percent body fat content was also calculated from the girth measurements as advocated by McArdle et al. The mean of % body fat content with this method was 14.91 +/- 3.82% in young men and 24.30 +/- 3.35% in middle aged men. On comparison, the difference in percent body fat content calculated by both the methods was found to be significant in young men but not for middle aged men. The correlation, coefficient between girth method and skinfold method was 0.95 in case of young men and 0.90 for middle aged men. Therefore, we advocate that girth measurements can be used to determine percent body fat content, main advantage being simplicity of technique and requirement of inexpensive instruments for measurement.

Adipose Tissue↗
PubMed1998

Comparison of two homogeneous assays with a precipitation method and an ultracentrifugation method for the measurement of HDL-cholesterol.

We report on the performance of four HDL-cholesterol assays: a homogeneous method based on polyethylene glycol-modified enzymes/alpha-cyclodextrin sulfate (PEGME; Kyowa); a homogeneous method based on polyanion-polymer/detergent (PPD; Daiichi); the usual precipitation method with phosphotungstic acid/MgCl2 (PTA); and an ultracentrifugation (UC) procedure. The homogeneous HDL-cholesterol assays (performed with automated analyzers) were precise and correlated well with the PTA and UC assays. The specificity and accuracy of the PEGME method were better than those of the PPD method.

Chemical Precipitation↗
PubMedDate not supplied

A method for quantifying artefacts in mapping methods illustrated by application to headbanging.

Maps of disease rates (and other quantities) often must contend with variance associated with variable population sizes and low incidence within spatial units. These characteristics can lead to substantial statistical noise that can mask underlying spatial variation. As Gelman and Price illustrated, most conventional mapping methods fail to address this problem, and in fact can introduce statistical artefacts; mapped quantities can show spatial patterns even when there are no spatial patterns in the underlying parameter of interest. Kafadar evaluated the performance of the headbanging algorithm for spatial smoothing (Tukey and Tukey, Hansen) for eliminating small scale variation and preserving edge structure. Here we perform a simulation study to investigate the artefacts of maps smoothed by unweighted and weighted headbanging. We find substantial artefacts that depend on the spatial structure of the statistical variation (for example, the spatial pattern of sample sizes) and on the details of the spatial distribution of geographic units. The methods used here could readily be adapted to study other spatial smoothers; we choose headbanging because (i) it is an important method used in practice, and (ii) its heavily computational nature is naturally studied using simulation (in contrast to the analytical methods used by Gelman and Price).

Artifacts↗
PubMed1978

A selected ion monitoring method for the determination of pethidine and norpethidine in plasma. Comparison with a gas chromatographic method using electron capture detection.

An analytical procedure for the simultaneous determination of pethidine and norpethidine in plasma by selected ion monitoring is described. The method has a capacity of 15--20 analyses per hour and can be used to determine pethidine and norpethidine down to 25 ng ml(-1) and 5 ng ml(-1), respectively. The selected ion monitoring method has been compared with a method based on electron capture detection after analysis of pethidine and norpethidine in spiked plasma samples and in plasma from patients. The two methods are capable of performing selective and accurate determinations of pethidine and norpethidine, in the concentration ranges obtained in man after a single therapeutic dose of pethidine.

Chromatography, Gas↗
PubMed1976

Comparison of methods to calculate cardiac output using the CO2 rebreathing method.

A comparison was made of methods used to calculate cardiac output by the indirect (CO2) Fick procedure (equilibrium method). Alternative methods for calculation of arterial PCO2, mixed venous PCO2, and conversion of gas tension to content were tested. Cardiac output values determined with a "corrected" equilibrium PCO2, to approximate mixed venous PCO2, were observed to be closest to cardiac output values determined on similar populations by the dye dilution method. Arterial PCO2 was best estimated from the Bohr equation using a dead space in exercise from prediction equations in the literature applicable to the populations under study. CO2 dissociation curves used to derive the veno-arterial CO2 content difference, were shown to differ considerably. For the present, the curve by McHardy [25], as modified by Jones (personal communication), and similar to the standard Comroe curve [5], was chosen.

Adolescent↗
PubMed1975

A new assay method for hydrogenase based on an enzymic electrode reaction. The enzymic electric cell method.

A new assay method for hydrogenase [EC 1.12.2.1] based on the enzymic electrode reaction of H2-H+ equilibrium has been established. The method is based on the experimental fact that the short-circuit current of the electric cell composed of an electrode with hydrogenase and methylviologen as the mediator of H2-H+ equilibrium and a saturated calomel electrode as the counter electrode, is practically proportional to the amount of hydrogenase in the cell. The new method is referred to as the "enzymic electric cell method." This technique has applications not only to routine activity assay but also to the direct determination of the time course of enzyme denaturation, which has not previously been possible.

Cytochrome c Group↗
PubMed1972

Quality control of antimicrobial disc susceptibility testing with a rapid method compared to the standard methods.

A rapid method for assay of antimicrobial agents in human serum was modified to provide a method for rapidly assessing the activity of antimicrobial discs being used for susceptibility testing. Each morning, discs are taken from the clinical laboratory's working supply and are applied directly onto test plates which have been inoculated, preincubated, and stored in a refrigerator. Inhibitory zones can be measured within 5 to 6 hr, i.e., before that day's batch of tests is to be set up. If the zone of inhibition for any agent is more than 2 standard deviations below the mean, the discs are discarded and another cartridge is selected from the stock supply for that day's susceptibility tests. In this way, discs of questionable potency are discarded before they are used for testing, rather than waiting until the next day as is usually done with the standard methods. The rapid control test yields zones which are slightly smaller and somewhat more variable than with the standard Kirby-Bauer or agar overlay methods, but the slight decrease in precision is outweighed by the advantages of rapidity and simplicity.

Methods↗
PubMed1984

Correction for tissue attenuation in radionuclide gastric emptying studies: a comparison of a lateral image method and a geometric mean method.

Variation in depth of radionuclide within the stomach may result in a significant error in the measurement of gastric emptying if no attempt is made to correct for gamma-ray attenuation by the patient's tissues. In this study a method of attenuation correction, which uses a single posteriorly located scintillation camera and correction factors derived from a lateral image of the stomach, was compared with a two-camera geometric mean method, both in phantom studies and in five volunteer subjects. A meal of 100 g of ground beef containing 99Tcm-chicken liver, and 150 ml of water, was used in the in vivo studies. In all subjects the geometric mean data showed that solid food emptied in two phases: an initial lag period, followed by a linear emptying phase. Using the geometric mean data as a standard, the anterior camera overestimated the 50% emptying time (T50) by an average of 15% (range 5-18) and the posterior camera underestimated this parameter by 15% (4-22). The posterior data, corrected for attenuation using the lateral image method, underestimated the T50 by 2% (-7 to +7). The difference in the distances of the proximal and distal stomach from the posterior detector was large in all subjects (mean 5.7 cm, range 3.9-7.4). We conclude that attenuation effects may account for large errors in the measurement of gastric emptying with radionuclide methods and that the application of correction factors derived from a lateral image of the stomach reduces these errors.

Adult↗
PubMedDate not supplied

[Assessment of drug-related risk using expected/observed methods (standardized rate method): definition and application to pharmacovigilance].

Indirect standardisation or the standardised rate method, consists of a comparison of the number of observed and expected cases. This method could be applied in the field of pharmacovigilance in order to investigate the potential relationship between drug exposure and the occurrence of an adverse event. It consists of the calculation of an expected number of events obtained by multiplying the exposed population by the event rate in the reference population. The comparison is made by means of a standardised mortality or incidence ratio (SMR or SIR). Three examples of this method are presented. The first example concerns central nervous system demyelinating disorders and hepatitis B vaccine, where the SIR calculated from spontaneous reports was equal to 1.05 (95% CI [0.82-1.26]). In the second example, the SMR of cardiovascular deaths related to sildenafil was significantly different from 1 (0.69, [0.43-1.08]) using data from prescription-event monitoring. In the last example, a strong association between acute leukaemia and chemotherapy in breast cancer was found (SIR 28.5, [12.3-56.2]) using exhaustive data from cancer registries. This method allows a quick and cheap risk assessment, although the quality of available data may limit validity of results. In this case, the hypothesis need to be examined by further ad-hoc clinical and pharmacoepidemiological studies.

Antineoplastic Agents↗
PubMed2006

[Control study of therapeutic effects of three phase acupuncture method and routine acupuncture method on periarthritis of shoulder].

OBJECTIVE: To compare therapeutic effects of the three phase acupuncture method and routine acupuncture method on periarthritis of shoulder. METHODS: Randomized, controlled and single blind method was adopted and 70 cases were divided into a three phase acupuncture group and a routine acupuncture group, 35 cases in each group. Same acupoints were selected in the two groups and selection of acupoints, manipulation of the needle and motion in the three phase acupuncture group were conducted by stages. RESULTS: The effective rate was 97.15% in the three phase acupuncture group which was better than 87.10% in the routine acupuncture group (P < 0.05). After treatment, VAS scores decreased significantly in the two groups (P < 0.01), and there was a significant difference between the two groups in the difference of VAS after treatment (P < 0.01). CONCLUSION: The three phase acupuncture treatment was superior to the routine acupuncture therapy in therapeutic effect on periarthritis of shoulder.

Acupuncture Therapy↗
PubMed1978

Two immunofluorescent methods compared with a radial immunodiffusion method for measurement of serum immunoglobulins.

We found high correlations when the values for immunoglobulins G, A, and M, obtained from the analysis of a group of 50 or more human sera by a measured-time radial immunodiffusion method, were compared to values found by two new commercial immunofluorescent methods. The Fiax and the Immuno-Fluor systems make use of fluorescently labeled antibodies and solid-phase immunoadsorbents and offer simple, precise, and objective methods for immunoglobulin quantitation. The Fiax procedure is less time consuming than is the Immuno-Fluor and gives IgG and IgA concentrations that are in close agreement with those found by radial immunodiffusion and IgM values that are significantly lower than the radial immunodiffusion values. The IgG results determined by the Immuno-Fluor method compare well with the radial immunodiffusion results, uhile the IgA values are significantly higher and IgM values significantly lower than those obtained by radial immunodiffusion.

Evaluation Studies as Topic↗
PubMed1981

[Citrate method of extracting antigens from Shigella sonnei. I. Comparison with other methods].

The comparative characteristic of extracts obtained from Sh. sonnei by the method of Raynaud and Digeon and neurotoxin obtained by sedimentation with trichloroacetic acid from chloroform autolysates by the method of Mesrobeanu et al. is presented. Both preparations were shown to be similar in their antigenic structure and immunogenicity for mice and guinea-pigs. Nevertheless the extracts obtained by the citrate method contained considerably less protein and endotoxin and had no enterotoxic activity. This allows to recommend the citrate method for extracting protective antigens from Sh. sonnei.

Animals↗
PubMed1980

[Determination of proteins with the Coomassie brilliant blue G 250 method. III. Behavior of various pure proteins and comparative analysis with the biuret and Lowry methods].

Some proteins were tested by the Bradford's method with Coomassie Brilliant Blue G 250. The findings were compared to those obtained by the Lowry's and the biuret methods. Coomassie, as the other methods, has the inconvenient of giving different absorbaces according to the nature of single protein. The use of standards of analogous composition in assaying proteins by the Bradford's method is suggested.

Animals↗
PubMedDate not supplied

[Accelerated method of numerical analysis for the diagnosis of microorganisms: the transpose of a matrix method].

Numeric methods were used to analyse the characteristics of methane oxidizing bacteria in order to reveal descriptors that had a significant effect on the formation of phenones. It was found that descriptors with an equal degree of significance for the organisms being analysed could be assembled into groups by using the method of transposed matrix with the following processing by numeric methods. Poorly reproducible or instrumentally complicated characteristics can be excluded from these groups of descriptors (1 of 2, or 2 of 3), and the organisms would be identified then by using a limited range of characteristics. This technique seems to be appropriate as an accelerated method for diagnostics of methane oxidizing bacteria as well as any other organisms.

Bacteria↗
PubMed1982

Singh's method of the radiological quantitative evaluation of osteoporosis compared with the densitometric method.

The quantitative evaluation of osteoporosis by Singh's radiographic method, which is based on analysis of the trabecular pattern of the upper end of the femur, recognises seven successive grades of bone loss. This method has been shown, by comparison with bone densitometry, to be reliable both for the quantification of osteoporosis and as a screening method for early diagnosis. The method is sufficiently precise, and is not affected by independent factors such as variations of radiographic technique and the individual characteristics of the subject being tested.

Adult↗
PubMed1977

The estimation of fibrinogen levels in animal plasmas by a simple refractometric method. A comparison with a biuret method.

A comparison was made between a biuret (reference) method and a simple refractometric (test) method for measuring fibrinogen levels in 84 animal plasmas. Although the correlation between the two methods was high (4=0.90 P less than 0-001) there was considerable random variation in the refractometric results in relation to the biuret results. This was thought to be due in part to the fact that refractometric results could only be expressed in multiples of 2.4 g/litre. In spite of this limitation, the refractometric method, on the grounds of speen and simplicity, is considered to have worthwhile application for fibrinogen determinations in practice laboratory.

Animals↗
PubMed1998

Reference method for detection of Pgp mediated multidrug resistance in human hematological malignancies: a method validated by the laboratories of the French Drug Resistance Network.

Multidrug resistance (MDR) associated with overexpression of the MDR1 gene and of its product, P-glycoprotein (Pgp), plays an important role in limiting cancer treatment efficacy. Many studies have investigated Pgp expression in clinical samples of hematological malignancies but failed to give definitive conclusion on its usefulness. One convenient method for fluorescent detection of Pgp in malignant cells is flow cytometry which however gives variable results from a laboratory to another one, partly due to the lack of a reference method rigorously tested. The purpose of this technical note is to describe each step of a reference flow cytometric method. The guidelines for sample handling, staining and analysis have been established both for Pgp detection with monoclonal antibodies directed against extracellular epitopes (MRK16, UIC2 and 4E3), and for Pgp functional activity measurement with Rhodamine 123 as a fluorescent probe. Both methods have been validated on cultured cell lines and clinical samples by 12 laboratories of the French Drug Resistance Network. This cross-validated multicentric study points out crucial steps for the accuracy and reproducibility of the results, like cell viability, data analysis and expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗