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At least 613 records · Page 34Linked to original sources
PubMed2003

[Preimplantation genetic diagnosis (PGD) of chromosomal aberrations using the fluorescence in situ hybridization method (FISH)--introduction to problems, sampling methods and examination techniques].

OBJECTIVE: Presentation of preimplantation genetic diagnosis and the set of laboratory processes like aspiration, preparation and evaluation of polar bodies, sperm cells and blastomeres using FISH method (fluorescent in situ hybridization) in ART. DESIGN: Review. SETTING: Sanatorium REPROMEDA, Brno, Veterinary Research Institute, Brno. METHODS: Overview of published data and own clinical experience with the cell aspiration methods, evaluated sample preparation and the proper chromosomes visualisation using FISH method. CONCLUSION: The review brings an overview of conditions and methods including sample obtaining, FISH analysis preparation and implementation, processed during PGD.

Chromosome Disorders↗
PubMed1992

[Measurement of cardiac output by invasive methods: methods and variability].

Invasive techniques for the measurement of cardiac output include the Fick method, the marker dilution method and radiological ventriculography. The principles, methods and accuracy of these techniques are described. The reference method remains that of Fick, despite its being less widely used now because of its complicated nature and its technical limitations (need for strict baseline conditions, precision of sampling). The thermodilution method is often performed. It is easy and provides reliable results, except in conditions of low cardiac output or when there is severe tricuspid insufficiency. Radiological ventriculography is used less for the measurement of cardiac output, since it is heavily dependent upon heart rate and theoretical geometrical models. It remains valuable for the quantification of mitral and aortic regurgitation.

Cardiac Output↗
PubMed2004

[Comparing two kinds of labeled streptavidin biotin methods and selecting the best antigen retrieval method].

OBJECTIVE: To compare two kinds of labeled streptavidin biotin(LsAB) methods and provide the optimal method of antigen retrieval. METHODS: The alkaline phosphatase(AP) LsAB method and the horseradish peroxidase (HRP) LsAB method were used to stain anti-tryptase in paraffin embedding tissue of patients with chronic obstructive pulmonary disease (COPD) and their staining effects were compared. The antigens were repaired by high pressure cooking, tryptin digestion and microwave, and the repairing effects were compared. RESULTS: The backgrounds of stained sections were more distinct and the color distinction of nucleus and positive signal were brighter by AP-LsAB, compared with those by HRP-LsAB; the repairing effect of high pressure cooking was better than the repairing effect of tryptin digestion and than that of microwave. CONCLUSION: AP-LsAB and high pressure cooking retrieval were recommended for use in immunohistochemical staining of pulmonary inflammatory tissue.

Alkaline Phosphatase↗
PubMed2004

[Study on the calculation methods of confidence intervals of genetic parameter estimates by method R and number of repeating estimations].

The objective of the study was to probe the calculation methods of confidence intervals of genetic parameter estimates by Method R and influences of number of repeating estimations (NORE). Four models were used to generate the datasets by simulation. The datasets originated from 200 sires and 2 000 dams and simulation progressed by BLUP( Best Linear Unbiased Prediction) selection for five overlapping generations. Variance components were estimated by using multivariate multiplicative iteration (MMI), combined with preconditioned conjugate gradient (PCG) to solve the mixed model equations. Parameter estimates and their standard errors and confidence intervals were computed by classical method, classical method after Box-Cox transformation and bootstrapping. The results showed that when NORE was larger, all three methods were feasible, but when NORE was fewer, bootstrapping was recommended. Fewer NORE was feasible under simple models, but more NORE was needed for complex models. Direct heritabilities were overestimated with the increase of number of random effects, but underestimation was found for many parameters with the increase of iteration numbers of PCG and MMI.

Animals↗
PubMedDate not supplied

Evaluation of the VIDAS Listeria (LIS) immunoassay for the detection of Listeria in foods using demi-Fraser and Fraser enrichment broths, as modification of AOAC Official Method 999.06 (AOAC Official Method 2004.06).

A multilaboratory study was conducted to compare the VIDAS LIS immunoassay with the standard cultural methods for the detection of Listeria in foods using an enrichment modification of AOAC Official Method 999.06. The modified enrichment protocol was implemented to harmonize the VIDAS LIS assay with the VIDAS LMO2 assay. Five food types--brie cheese, vanilla ice cream, frozen green beans, frozen raw tilapia fish, and cooked roast beef--at 3 inoculation levels, were analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study, 1206 test portions were tested, of which 1170 were used in the statistical analysis. There were 433 positive by the VIDAS LIS assay and 396 positive by the standard culture methods. A Chi-square analysis of each of the 5 food types, at the 3 inoculation levels tested, was performed. The resulting average Chi square analysis, 0.42, indicated that, overall, there are no statistical differences between the VIDAS LIS assay and the standard methods at the 5% level of significance.

Animals↗
PubMedDate not supplied

Comparative validation study to demonstrate the equivalence of a minor modification to AOAC methods 996.09, Vip for EHEC and 996.10, assurance Eia EHEC with the reference culture method for the detection of Escherichia coli O157:H7 in beef.

The Visual Immunoprecipitate Assay (VIP) method for the detection of enterohemorrhagic Escherichia coli O157:H7 (VIP for EHEC) and Assurance Enzyme Immunoassay (EIA) method for the detection of EHEC (EHEC EIA) are AOAC INTERNATIONAL Official Methods 996.09 and 996.10, respectively. A minor modification to the enrichment medium used in both methods has been developed. This modification, the BioControl modified EHEC medium (BioControl mEHEC) provides a more cost-effective procedure with performance equivalent to that of the cultural method for detection of E. coli O157:H7 in beef.

Animals↗
PubMed2005

A re-evaluation of plasma sialic acid determination using the periodate resorcinol method versus the enzymatic method.

The concentration of plasma sialic acid was estimated using the modified chemical method and the more sensitive enzymatic method in 20 subjects with impaired glucose tolerance and 20 control subjects. The mean sialic acid concentration values of the control subjects and subjects with impaired glucose tolerance using the enzymatic method were 1.747 +/- 0.047 and 2.583 +/- 0.070 mmole/l and 1.753 +/- 0.067 and 2.591 +/- 1.02 mmole/l for the chemical method. The intra-assay coefficient of variation for the control subjects and for the subjects with impaired glucose tolerance were 1.963% and 1.583%, respectively, for the enzymatic assay and 2.728% and 2.431%, respectively, for the chemical assay. The inter-assay coefficient of variation for the control subjects and for the subjects with impaired glucose tolerance were 2.686% and 2.723% for the enzymatic assay, and 3.819% and 3.95% for the chemical assay. Since the values do not differ significantly, the chemical assay is a cost effective method that can be used in large epidemiological studies.

Chemistry Techniques, Analytical↗
PubMed1990

Proposed reference method for iron in serum used to evaluate two automated iron methods.

The manual Reference Method of the Centers for Disease Control for serum iron (CDC/RM/Fe) and a semiautomated adaptation of it were used to evaluate two working methods: one, a detergent solubilization procedure for the Roche Cobas-Bio analyzer, the other, the Kodak Ektachem 700 procedure, based on dry-film technology. The CDC/RM/Fe and its semiautomated version gave essentially the same results for 40 sera from hospital patients. This semiautomated version was in turn compared with the two working procedures in a study involving 200 patients. Each of the working methods correlated well with the semiautomated CDC/RM/Fe method. Separate recovery and interference studies indicated satisfactory analytical recovery of iron in all cases, but the detergent solubilization method was found to be susceptible to interference by hemoglobin, lipemia, and bilirubin.

Autoanalysis↗
PubMed1990

The AMeX method: a multipurpose tissue-processing and paraffin-embedding method. II. Extraction of spooled DNA and its application to Southern blot hybridization analysis.

In our previous report, we described a new fixation and paraffin-embedding method (the AMeX method) that preserves many of the antigens that are normally destroyed by routine formalin fixation. The current study was conducted to examine the preservation of high-molecular-weight DNA in tissues processed by this method. DNA was extracted from AMeX-processed tissue sections after deparaffinization by the same method as that used to extract DNA from fresh tissues. The total amounts of DNA extracted from 10 mg each in wet weight of AMeX-processed and fresh mouse liver tissues were identical. In tissues of malignant lymphoma, the total amount of spooled DNA extracted from 50 sections, each 20 microns thick, was about 8 micrograms/mm2. The electrophoretic pattern of DNA digested with restriction endonucleases on agarose gel from AMeX-processed tissue sections did not differ from that of fresh materials. Southern blot hybridization analysis also revealed that the mobility of specific DNA fragments was identical for AMeX-processed and fresh tissues. The AMeX method was thus proved to be a versatile multipurpose tissue-processing procedure, which is expected to provide important information regarding the correlation between morphology, phenotypic expression, and gene alteration.

Blotting, Southern↗
PubMed1985

[Determination of estrogen receptors in 160 breast tumors using monoclonal antibodies: comparison of Abbott's immunoenzymatic method with the carbon dextran method].

Estrogen receptor determinations were performed on 241 cytosols from 160 breast cancer tumors, using both dextran coated charcoal method (D.C.C.) and monoclonal antibodies (Abbott's ER-EIA kit) in order to compare the two methods, and to evaluate the clinical usefulness of this new immunological simplified assay. Intra- and inter-assay reproducibility were studied during a six month period. Intra-assay of both methods were lower than 5%. Inter-assay variation coefficients of ER-EIA studied on 35 standard curves varied from 12.5% (standard: 0) to 6.7% (standard: 250 fmoles/ml). ER determination of 80 human breast cancers were performed both by EIA and Scatchard analysis. The regression curve obtained was (EIA) = 1.04 (Scatchard) + 21 fmoles/mg of proteins (r = 0.963). With 153 breast cancer cytosols whose volume was too small for multipoint Scatchard analysis, EIA results were compared to results obtained by a "near saturating" concentration of tritiated ligand (5 nM). The regression curve obtained was (EIA) = 1.34 (5nM) + 5 fmoles/mg proteins (r = 0.978). These results can be compared with those obtained between Scatchard and 5 nM: (Scatchard) = 1.29 (5nM) - 9 fmoles/mg proteins (r = 0.985). Reproducibility was studied on clinical specimens assayed at two different periods during the clinical evaluation. Regression curves obtained were (2nd assay) = 1.05 (1st assay) - 5.5 fmoles/mg proteins for EIA, and (2nd assay) = 0.96 (1st assay) + 9 fmoles/mg proteins for DCC method. EIA assay presented an high stability for protein concentrations very low, up to 0.2 mg/ml. Finally, a very good correlation was obtained between ER-EIA and DCC method, and ER-EIA seemed specially well fitted to small tumors.

Adult↗
PubMed1987

PF 4 assay by an ELISA method: a good correlation with the usual RIA method.

PF 4 is a specific platelet protein. This protein is released from alpha granules during the platelet activation and later it adheres to endothelium. Intravenous heparin injection displaces PF 4 from vessels wall. Thus, PF 4 levels are an index of in act or past platelet activation. We have compared two methods of PF 4 dosage on 39 blood samples taken from healthy volunteers and patients. The samples has been shared out tree groups according to the procedure of collecting; so the values of PF 4 are widely enough distributed. There was no difference between the mean values of each group obtained with two methods. Equally the mean value of all samples processed with radioimmunoassay was similar to the mean value obtained with immunoenzymatic method. The correlation index between the values of PF 4 obtained with radioimmunoassay and immunoenzymatic method was 0.97. Therefore the new immunoenzymatic method for the dosage of PF 4 is as sensitive and precise as the radioimmunoassay.

Blood Specimen Collection↗
PubMedDate not supplied

Comparison of the ion exclusion chromatographic method with the Monier-Williams method for determination of total sulfite in foods.

Experimental data comparing the alkali extraction/ion exclusion chromatographic method with the Monier-Williams method for determination of total sulfite are presented in (a) enzymatic and nonenzymatic browning systems, (b) vegetables containing naturally occurring sulfite, and (c) a carbohydrate-type food additive, erythorbic acid. Excellent agreement, with a linear correlation coefficient of 0.99, was observed in fresh potato samples homogenized with sulfite and allowed to react for different time intervals (enzymatic browning system). A good overall correlation was observed in dehydrated, sulfited apple samples heated for different times (nonenzymatic browning system); however, as heating time increased, higher results were obtained by the Monier-Williams method than by the alkali extraction/ion exclusion chromatographic method. The results of determining sulfite in the alkali trapping solution following acid distillation or acid treatment without heat suggested that this deviation was due to a fraction of sulfite bound to the browning reaction products in such a way that it was released by acid distillation but not by alkali extraction or acid treatment without heat. Similar behavior was demonstrated in cabbage with naturally occurring sulfite, which was released by acid distillation but not by alkali extraction or acid treatment without heat. The ion exclusion chromatographic method could overcome interference by the volatile caramelization reaction products in the Monier-Williams determination of erythorbic acid.

Brassica↗
PubMed1988

A commercial enzyme immunoassay method (EMIT) compared with liquid chromatography and bioassay methods for measurement of chloramphenicol.

A new enzyme immunoassay method (EMIT; Syva Co.) was compared with conventional high-performance liquid chromatography (HPLC) and agar-diffusion bioassay methods for measurement of chloramphenicol in human serum. Forty-nine serum samples were assayed by each of the three methods. Excellent correlation was observed between values by EMIT and by the two conventional methods (r = 0.986 and 0.961). Precision was acceptable (CV less than 5%) with EMIT. Assay of samples containing chloramphenicol glucuronide and chloramphenicol succinate demonstrated that EMIT recognizes only the biologically active (base) form of the drug. The capability to test serum samples as small as 0.2 mL, adaptation to widely available instrumentation, and provision of rapid results are principal advantages of the EMIT method for routine chloramphenicol measurements.

Biological Assay↗
PubMed1979

[Results of testing a new method of using antibiotics in nutrient media for the isolation of Shigella: the 2-streak method].

A new variant of media with antibiotics for isolation of Shigella, i.e. a method of 2 streaks each containing different antibiotics was tested in analysis of excrements from patients with acute dysentery. It was found that the new method is more effective than the well known method of gradient plates (isolation of Shigella in one series of the experiments amounted to 85.2 and 64.7 per cent respectively, and in the other series of the experiments the respective figures were 95.4 and 89.3 per cent). Its efficiency was lower as compared to the procedure of inoculation onto 2 plates, i.e. onto the media with and without an antibiotic (isolation of Shigella was 67.5 and 77.4 per cent respectively). The new method provided a higher frequency of Shigella isolation as compared to inoculation onto the media without an antibiotic, as well as onto any of the media used with one antibiotic. The method of 2 streaks offers wider possibilities for choosing the antibiotics for adding to the nutrient medium, as well as estimation of the antibioticograms and species structures of Shigella distributed in a concrete area.

Anti-Bacterial Agents↗
PubMed1985

Six methods for isolating high-density lipoprotein compared, with use of the reference method for quantifying cholesterol in serum.

Using 90 serum specimens, we compared six routine procedures for high-density lipoprotein (HDL) isolation to determine the biases, if any, of each. Use of the Reference Method for cholesterol (Duncan et al., Centers for Disease Control, Atlanta, GA) and automated dispensing equipment helped ensure the accuracy of the cholesterol measurements and minimized errors from sample and reagent manipulations. Regression analysis of the results showed significant differences between most HDL isolation methods, except for those involving precipitation with heparin-MnCl2 (1.0 mol/L) or polyethylene glycol 6000, which yielded comparable results with a slope close to one and a zero intercept. The dextran sulfate (Mr 500 000)-MgCl2 method had the largest proportional and constant bias with respect to those two methods. All the methods produced comparable results in the clinically important low HDL-cholesterol range (250 to 350 mg/L), but biases were significant at high concentrations. We conclude that these increased biases in the upper ranges of HDL-cholesterol concentrations are the result of increased heterogeneity of HDL and the different mechanisms involved in forming the insoluble complexes between lipoproteins and the various precipitation reagents.

Analysis of Variance↗
PubMed1977

A rapid and sensitive method using immunological nephelometric analysis to evaluate the gel-filtration method. (Application to the diagnosis of rubella).

Immunological nephelometric analysis has been shown to be a more sensitive method than either immunoelectrophoresis or gel-diffusion for testing the gel-filtration method of human immunoglobulins sera. This method has the advantages of facility, rapidity and sensitivity. We have compared this method to radial immunodiffusion. This method can be applied to locate with precision any antigens after gel-filtration or ion-exchange chromatography.

Antibodies, Anti-Idiotypic↗
PubMed1977

Determination of serum bilirubin concentration during phototherapy of newborns and in vitro: results compared by the direct spectrometric method and the diazo method.

During direct illumination of a serum bilirubin solution the bilirubin concentration decreased markedly, both as determined by the direct spectrometric method and (even more so) by the diazo method. In contrast, I found the same values for serum bilirubin concentrations as determined by these two methods for serum from untreated, "single light", and "double light" treated full-term infants with neonatal hyperbilirubinemia without blood type immunization. The same was true for untreated and "single light" treated premature infants with this disease. Furthermore, no difference was found in the above-mentioned relationship between "single light" treated infants with the same disease, and untreated infants with neonatal hyperbilirubinemia without immunization, all born at term. This is important, because the direct spectrometric method is simpler and requires less serum than does the diazo method.

Azo Compounds↗
PubMed1977

[New method of determination of carboxyhemoglobin by the conductometric method of extraction of carbon monoxide from the blood].

The newly elaborated method consists in the gasometric CO determination in the blood. The extraction of CO from the blood sample (0,1-1,0 ml) is performed by means of a simple device designed by the authors. The extracted CO is determined by gas analyser ANKO-3 or Ultragas 5. The comparison between the new method and iodometric method showed very high correlation (r greater than 0,9). A discussion follows on the advantages of the new method (quick, easy, high-sensitive and precise), its use can be suggested to laboratories which are equipped with a gas analyser ANKO-3 for other purposes. The new method can be used for numerous routine analyses as well as for scientific studies.

Carbon Monoxide↗