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At least 343 records · Page 19Linked to original sources
PubMed2001

Comparison of volatile components in dried scallops (Chlamys farreri and Patinopecten yessoensis) prepared by boiling and steaming methods.

Comparison of two types of dried scallops, Chlamys farreri and Patinopecten yessoensis, and effects of preparation methods (boiling and steaming) on the composition of their volatile components were carried out by simultaneous steam distillation and extraction and with analysis by gas chromatography-mass spectrometry. One hundred and seventy-two compounds were identified, three tentatively. Qualitatively, both scallops had similar components. Quantitatively, C. farreri contained more components with higher levels in aldehydes, alkanes, naphthalenes, esters, furans, miscellaneous compounds, alcohols, and ketones, whereas P. yessoensis had more components with higher levels in aromatics, pyrazines, pyridines, sulfur-containing compounds, and terpenes from both boiling and steaming methods. Comparison between methods for the same scallop showed that similar qualities of components were detected. Overall, more compounds with higher levels were detected from the boiling method.

Alcohols↗
PubMed1977

Evaluation of the dual-precipitation method by comparison with the ultracentrifugation method for measurement of lipoproteins in serum.

We evaluated the dual-precipitation method for quantitative measurement of lipoproteins as described by Wilson and Spiger [J. Lab. Clin. Med. 82, 473 (1973)] for normo- and hyperlipemic sera, by comparison with the results obtained with ultracentrifugation. If serum with an above-normal triglyceride concentration is analyzed, the very-low-density lipoprotein cholesterol value obtained with the precipitation method is usually too low. For measurement of high-density lipoprotein cholesterol the ultracentrifugation and precipitation procedures give comparable results, but the latter method is preferred because sinking pre-beta-lipoproteins present in the high-density lipoprotein fraction isolated by means of the ultracentrifuge may result in falsely high values for cholesterol in that fraction. Therefore, at least for the determination of very-low-density lipoprotein cholesterol in hyperlipemic serum, the use of an ultracentrifuge remains necessary. Because few laboratories have an ultracentrifuge at their disposal, it seemed important to look at the stability of sera in view of the forwarding of samples. Also, a way of increasing the efficiency of the ultracentrifuge was studied. Sera can be stored for a week at 4 degrees C or for 54 h at room temperature without noticeable effect on lipoprotein values. Moreover, reliable values can be obtained with an ultracentrifugation time of 8 h (0.8 X 10(8) g-min).

Chemical Precipitation↗
PubMed1984

Determination of heparin activity by a new laser nephelometric method and comparison to the USP method.

A new method for the determination of heparin activity in solutions has been developed, based on the increase in light scattering observed during the clotting of plasma. The recalcification clotting time (RCT) of sheep plasma is measured in the presence of heparin, using a laser nephelometer. The activity of heparin in the sample is determined from a standard curve of the logarithm of RCT versus heparin activity. The results indicate that this method is simpler, faster, and more reproducible than the current USP grading method.

Animals↗
PubMed1990

Skin sampling-validation of a pad method and comparison with commonly used methods.

Two types of pad were tested for sampling bacteria from the skin. One pad was made of 85% viscose and a 15% mixture of polyester and polyamide fibres, the other was made of polyvinyl-alcohol foam. The efficiency was calculated using double samples and 8 consecutive samples. The two pads were equally efficient and more efficient when moist. Their efficiency was compared with that of the bud swab, the Rodac plate and the scrub cylinder method. Using the double sample method for calculation, the scrub cylinder method and the pads were equally efficient, around 50%. As calculated from consecutive samples the efficiency of the pads was about 45%, the efficiency of the cylinder scrub method 29%, and that of the bud swab and Rodac plate 16% and 5% respectively. The low efficiency of the Rodac plate may be partly explained by the fact that microcolonies and not bacterial cells are sampled with this method.

Bacteria↗
PubMed1984

Bilirubin binding in the plasma of newborns: critical evaluation of a fluorescence quenching method and comparison to the peroxidase method.

Bilirubin binding affinities and capacities and apparent unbound ("free") bilirubin levels were determined in serum samples from 47 high-risk newborns, in 22 samples of cord serum, and in serum samples from 15 Greek children with marked hyperbilirubinemia, by both fluorescence quenching and peroxidase methods. The free fatty acid:albumin molar ratio was also determined for serum samples from high-risk newborns. In vitro and in vivo measurements suggest that free fatty acids are rarely present at levels that produce significant displacement of bilirubin, which is in agreement with previous studies. The two bilirubin binding assays showed only fair correlation with sizable discrepancies for many specimens. Technical difficulties inherent in the fluorescence quenching method and possible sources of error are discussed. Our observations suggest that routine application of these two assays as the primary criterion for therapeutic intervention (e.g., exchange transfusion) is premature.

Bilirubin↗
PubMed1996

[The accuracy of blood alcohol determination with head-space GC, ADH and REA ethanol assay for the AXSYM system--a comparison of the methods].

The most commonly used methods for the determination of blood alcohol are the Head-Space Gas Chromatography (HSGC) and the ADH-Method. Abbott offers now a REA-ethanol Assay for the AXSYM-System. The accuracy of the 3 analytical procedural were checked by a method comparison. This involved blood alcohol concentration of 347 serum samples being determined by means of all 3 methods. The deviation of the results of double analysis within the respective method, the difference of the values when using 2 measuring methods each (HSGC-ADH, ADH-AXSYM, HSGC-AXSYM) and the standard deviation of the measurements from HSGC-AXSYM and HSGC-ADH were determined. The REA Ethanol Assay, which was developed for diagnostic and therapeutic questions in cases of alcohol intoxication works with an accuracy which suffices entirely for this task designation. However, the fixed regulation for determining blood alcohol in forensic use cannot be observed fully.

Alcohol Dehydrogenase↗
PubMed1992

Preferred use of primary radiolabeled anti-platelet monoclonal antibodies. Comparison of immunoblotting methods for the analysis of functional domains on human platelets.

Several methodologies used for the identification and characterization of platelet receptors for antiplatelet monoclonal antibodies are compared. Two antiplatelet monoclonal antibodies, are investigated due to their potent effects on human platelet function. A platelet-activating monoclonal antibody, called M.Ab.F11, is able to induce platelet aggregation and granular secretion. A platelet-inhibitory monoclonal antibody, named G10, strongly blocks the platelet aggregation and granular secretion induced by M.Ab.F11, as well as by physiological agonists. In order to identify the specific antigens recognized by these monoclonal antibodies, we tested a number of immunostaining methods. Comparison of various procedures revealed that a high degree of nonspecific interactions with platelet proteins occurred when the commonly used secondary reagents, protein A and radiolabeled or enzyme-conjugated secondary antibodies interacted with the platelet proteins either in the presence or absence of primary monoclonal antibodies. On the other hand, we observed a high degree of specificity and selectivity when only radiolabeled anti-platelet monoclonal antibodies were used as single reagents. It is established that M.Ab.F11 interacts with the platelet membrane proteins of 32 and 35 Kd, and M.Ab.G10 recognizes 100 Kd protein, which corresponds to GPIIIa molecule.

Antibodies, Monoclonal↗
PubMed2005

Chemometrics-assisted simple UV-spectroscopic determination of carbamazepine in human serum and comparison with reference methods.

In the present report, carbamazepine is determined on serum samples of real patients by a procedure completely assisted by chemometric tools. First, a response surface methodology based on a mixture design was applied in order to select the best conditions for the extraction step. Finally, partial least squares multivariate calibration (PLS-1) was applied to second-derivative UV spectra, eliminating a shift baseline effect that originated in the extraction procedure. The performance assessment included: (a) a three-level precision study, (b) a recovery study analyzing spiked samples, and (c) a method comparison with high-performance liquid chromatography (HPLC) and fluorescence polarization immunoassay (FPIA) applied on real patient samples. The obtained results show the potentiality of the presently studied methodology for the monitoring of patients treated with this anticonvulsant.

Calibration↗
PubMed1998

Carbohydrate deficient transferrin in the assessment of alcohol misuse: absolute or relative measurements? A comparison of two methods with regard to total transferrin concentration.

Carbohydrate deficient transferrin (CDT) is now accepted as a potentially useful marker for the detection of alcohol misuse. It is not clear whether absolute values or values expressed relative to the total transferrin concentration provide the same diagnostic efficiency. CDT was measured in 35 patients with alcohol related liver disease, 35 subjects abusing alcohol without evidence of liver disease and 35 patients with chronic viral hepatitis using two commercial methods (CDTect and %CDT). To compare the methods, results were normalised by dividing the actual result by the upper limit of the reference range. Subtracting normalised %CDT results from the normalised CDTect results demonstrated a linear relationship between CDTect and total transferrin. This linear relationship could be abolished by calculating the CDTect/total transferrin ratio. The sensitivity of the methods was similar with CDTect (43 and 57%) being slightly superior to %CDT (40 and 46%). Specificity was similar (78%) for both methods. Calculation of the CDTect/total transferrin ratio improved the sensitivity and specificity slightly. The linear relationship between CDTect and total transferrin may produce misleading results in populations with a high prevalence of abnormal total transferrin concentrations and could cause difficulties in method comparisons unless taken into account.

Adolescent↗
PubMed1984

Comparison of methods for estimating gentamicin clearance and retrospective analysis of changes in clearance with emphasis on patients with normal renal function.

The subjects were 29 general medical and surgical patients with apparently normal renal function at the start of treatment with gentamicin. Nine methods of estimating gentamicin clearance (CL) were compared as means of calculating gentamicin dosage. In 23 of the 29 patients CL was measured twice during treatment. The first measurement was based on 10 blood samples taken around a dose early in treatment. CL calculated from the area under the serum concentration-time curve using all 10 samples was designated a reference method for comparison with other methods. There was considerable inter-individual variation in CL. Serum creatinine and body weight gave poor estimates of an individual's CL. A good estimate of CL was obtained from four blood samples taken immediately before and 2, 3 and 4 h after dosing. Prediction of serum levels is not a good method for checking CL estimations. A significant decrease in CL was found during treatment. This was probably due to a reduction in glomerular filtration rate.

Adult↗
PubMed1998

Comparison of three methods for testing azole susceptibilities of Candida albicans strains isolated sequentially from oral cavities of AIDS patients.

Three susceptibility testing procedures were compared to determine fluconazole, itraconazole, and ketoconazole MICs against 47 Candida albicans strains isolated sequentially from the oral cavities of five AIDS patients undergoing azole therapy. They included the broth microdilution method (BM), performed according to the National Committee for Clinical Laboratory Standards' tentative standard, the agar dilution method (AD), and the Etest; the latter two tests were performed both in Casitone agar (AD-Cas and Etest-Cas) and in RPMI (AD-RPMI and Etest-RPMI). Twenty-four- and 48-h MICs obtained by AD and Etest were compared with 48-h MICs obtained by BM. The MICs of all the azoles determined by BM were usually lower than those obtained by the other methods, mainly due to different reading criteria. In order to assess the most appropriate way of evaluating the agreement of MICs obtained by different methods with those produced by the proposed reference method (BM), we used the mean differences calculated according to Bland and Altman's method. Comparison of fluconazole MICs obtained by BM and AD-Cas yielded a mean difference of 3, and the percentages of agreement within +/-2 dilutions were 98 and 100% at 24 and 48 h, respectively. For ketoconazole and itraconazole MICs, lower mean differences were noted, and agreement ranged from 96 to 100%. Agreement between the AD-RPMI and BM results was poor for all azoles, and an increase in MICs was always observed between the 1st- and 2nd-day readings. Similarly, Etest-Cas gave better agreement with BM than did Etest-RPMI for all the azoles. BM, AD-Cas, and Etest-Cas each demonstrated a progressive increase in fluconazole MICs against strains isolated sequentially from a given patient, in accordance with the decreased clinical response to fluconazole.

AIDS-Related Opportunistic Infections↗
PubMed2006

Selection of optimum sorption kinetics: comparison of linear and non-linear method.

Comparison of linear least-squares method and a trial and error non-linear method of estimating the kinetic parameters was examined to the experimental data of methylene blue onto activated carbon. Two most commonly used kinetic equations first order kinetics and pseudo second order kinetics was used to analyze the experimental data. The four different form of Ho's pseudo second order kinetic was also discussed. Present investigation showed that the non-linear analysis method as more appropriate method to determine the rate kinetic parameters.

Adsorption↗
PubMed2000

Calibration and comparison of the acoustic location methods used during the spring migration of the bowhead whale, Balaena mysticetus, off Pt. Barrow, Alaska, 1984-1993.

Between 1984 and 1993, visual and acoustic methods were combined to census the Bering-Chukchi-Beaufort bowhead whale, Balaena mysticetus, population. Passive acoustic location was based on arrival-time differences of transient bowhead sounds detected on sparse arrays of three to five hydrophones distributed over distances of 1.5-4.5 km along the ice edge. Arrival-time differences were calculated from either digital cross correlation of spectrograms (old method), or digital cross correlation of time waveforms (new method). Acoustic calibration was conducted in situ in 1985 at five sites with visual site position determined by triangulation using two theodolites. The discrepancy between visual and acoustic locations was <1%-5% of visual range and less than 0.7 degrees of visual bearing for either method. Comparison of calibration results indicates that the new method yielded slightly more precise and accurate positions than the old method. Comparison of 217 bowhead whale call locations from both acoustic methods showed that the new method was more precise, with location errors 3-4 times smaller than the old method. Overall, low-frequency bowhead transients were reliably located out to ranges of 3-4 times array size. At these ranges in shallow water, signal propagation appears to be dominated by the fundamental mode and is not corrupted by multipath.

Acoustics↗