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At least 487 records · Page 27Linked to original sources
PubMed1996

Comparisons of methods of myocardial hypothermia for cardiac transplantation.

BACKGROUND: Myocardial hypothermia of less than 10 degrees C is an essential component of preservation of donor hearts before implantation. Here we report temperature changes and comparison of methods for maintenance of myocardial hypothermia during implantation. METHODS: Twenty patients were prospectively randomized into two equal groups. In one cohort myocardial hypothermia was maintained by the "Stanford method" of continuous lavage of the pericardium and left atrium with refrigerated saline solution. In the other a cooling jacket was used without saline lavage. Temperatures at multiple sites were measured at 30-second intervals from initiation of cardiac suturing until aortic cross-clamp removal. Comparisons were made between groups at each temperature site. RESULTS: The cooling jacket group temperatures were significantly lower at the left ventricular epicardium and endocardium than those of the Stanford method group. CONCLUSIONS: During cardiac implantation maintenance of myocardial hypothermia with a cooling jacket resulted in significantly deeper and more consistent hypothermia of the left ventricle than pericardial and left atrial lavage with refrigerated saline solution. Blood loss from aspirated saline lavage and perfusate dilution by the saline solution were eliminated.

Adult↗
PubMed2003

Comparison of isotope dilution mass spectrometry methods for the determination of total homocysteine in plasma and serum.

Two independent methods have been critically evaluated and applied to the measurement of total homocysteine in serum and plasma: solid-phase anion extraction (SPAE) gas chromatography/mass spectrometry (GC/MS) and protein precipitation liquid chromatography/tandem mass spectrometry (LC/MS/MS). In addition, analysis of samples prepared by SPAE was accomplished by liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS. These methods have been used to determine total homocysteine levels in several existing serum-based Standard Reference Materials (SRMs) from the National Institute of Standards and Technology and in patient plasma samples provided by the Centers for Disease Control and Prevention. The precision of the homocysteine measurements in serum and plasma was critically evaluated, and method comparisons were carried out using Bland-Altman plots and bias analysis. On the basis of the excellent precision and close agreement of the mass spectrometric (MS) methods, the MS-based methods will be used for certification of a serum-based SRM for homocysteine and folates.

Chromatography, Liquid↗
PubMed1988

Detection of circulating immune complexes by Raji cell assay: comparison of flow cytometric and radiometric methods.

Several flow cytometric methods for the measurement of circulating immune complexes (CIC) have recently become available. We report a Raji cell flow cytometric assay (FCMA) that uses aggregated human globulin (AHG) as primary calibrator. Technical advantages of the Raji cell flow cytometric assay are discussed, and its clinical usefulness is evaluated in a method comparison study with the widely used Raji cell immunoradiometric assay. FCMA is more precise and has greater analytic sensitivity for AHG. Diagnostic sensitivity by the flow cytometric method is superior in systemic lupus erythematosus (SLE), rheumatoid arthritis, and vasculitis patients: however, diagnostic specificity is similar for both assays, but the reference interval of FCMA is narrower. Significant correlations were found between CIC levels obtained with both methods in SLE, rheumatoid arthritis, and vasculitis patients and in longitudinal studies of two patients with cerebral SLE. The Raji cell FCMA is recommended for measurement of CIC levels to clinical laboratories with access to a flow cytometer.

Antigen-Antibody Complex↗
PubMedDate not supplied

Comparison between flow cytometric and cytogenetic tumor cell DNA content using a simple flow sample preparation method: ploidy comparison of 86 fresh pediatric tumors.

A comparison of tumor ploidy by flow cytometry (FL) and cytogenetics (CYG) was made in 86 fresh pediatric solid (n = 47) and hematopoietic (n = 39) tumors using simple sampling and semiautomated proprietary FL preparation methods and defined histogram interpretive criteria. Tumor karyotypes with 44-48 chromosomes were regarded as CYG diploid and other chromosomal complements CYG aneuploid for comparison purposes. Five histograms were uninterpretable and nine cases failed to produce 15 or more metaphases for karyotyping. Mean G0/G1 peak coefficients of variation of all 86 cases were 2.7 and 3.0 for the diploid and aneuploid populations, respectively. Of the 72 eligible cases, 41 were concordant diploid and 16 concordant aneuploid with an overall concordance of 79%. The DNA index and karyotypic index correlation coefficient was 0.92 for the 16 concordant aneuploid cases. Analysis of the 15 discordant cases highlights the limitations of both methods and of the histogram interpretive criteria and indicates that FL is probably more sensitive for detection of tumor aneuploidy as defined and detected by these methods.

Aneuploidy↗
PubMedDate not supplied

The use of a digital imaging technique to aid bite mark analysis.

Criminal cases occasionally involve the analysis of bite mark injuries. This paper presents a method of digital image enhancement of an injury and an overlay production method to improve the comparison between the dentition of a suspect and the image of the injury. A comparison method entirely within the digital image software is also illustrated. The use of digitally-produced overlays appears to provide a more objective method of comparison. The use of this method for shoe print, tyre mark and other blunt instrument injury analysis is noted.

Acetates↗
PubMed1983

Urine specific gravity measurements: comparison of a new reagent strip method with existing methodologies, as applied to the water concentration/dilution tests.

A study was carried out to compare a new, unique chemical strip test for the measurement of urine specific gravity with the traditional methods of hydrometry and refractometry, during water concentration/dilution tests in 12 normal subjects. The pattern of specific gravity results during these serial measurements was virtually identical for the strip and for the comparative methods. Comparison of the strip results with those obtained by both hydrometry and refractometry produced acceptable linear regression data. In addition, a close relationship was demonstrated between the strip specific gravity and urine osmolality. The findings show that the strip method is an acceptable alternative to traditional methods as an indicator of urine concentration.

Adult↗
PubMedDate not supplied

Quantitative analysis of flavonol glycosides in Ginkgo biloba: a comparison of two analytical methods.

A comparison of testing methods for constituents of Ginkgo biloba was performed as part of the process for determining which of the many available analytical methods was most appropriate for inclusion in the American Herbal Pharmacopoeia (AHP). Three primary methods were reviewed: those adopted by the European Pharmacopoeia, the National Science Foundation-Institute for Nutraceutical Advancement (NSF-INA) and the United States Pharmacopeia. Methods were compared by evaluating sample preparation and hydrolysis, precision and methods of total flavonol glycoside calculation by two independent laboratories. The AHP adopted the method of NSF-INA for inclusion in the AHP monograph owing to observed superiority of this method in terms of precision, glycoside calculation, ease of sample preparation and chromatographic parameters.

Chromatography, High Pressure Liquid↗
PubMed2001

A comparison of methods for yeast identification including CHROMagar Candida, Vitek system YBC and a traditional biochemical method.

BACKGROUND: CHROMagar Candida (CAC) is a new chromogenic medium for the presumptive identification of clinically-important yeast isolates. A yeast biochemical card (YBC), a part of the Vitek system is an automatic method for the identification of clinically-important yeast isolates. We conducted a comparison of these two methods with a traditional biochemical method in order to choose a rapid and accurate technique for yeast identification. METHODS: All yeast isolates were inoculated onto Sabourand dextrose agar (SDA) and CAC, and incubated at 30 degrees C for 48 hours. All isolates were simultaneously tested using traditional biochemical methods and the yeast biochemical card from the Vitek system. RESULTS: We evaluated 235 yeast isolates from clinical specimens, including 89 Candida albicans, 47 Candida tropicalis, 43 Candida glabrata, six Trichosporon beigelii, and five Candida krusei in addition to 45 isolates of other yeast species. Isolates were presumptively identified on the basis of colony color and appearance on CAC medium. These observations were compared with a traditional biochemical yeast-identification method and also with YBC from the Vitek system. For five commonly-isolated species (Candida albicans, Candida tropicalis, Candida glabrata, Candida krusei and Trichosporon beigelii), agreement among the CAC medium, YBC method and traditional biochemical method were 98.9% (187/189), 96.3% (182/189), 100% (189/189), respectively. CONCLUSIONS: From our comparison, the CAC medium is a convenient and economic method to identify five commonly-noted yeast species, and the YBC method warrants a greater cost and requires a longer period of time to obtain reliable results.

Candida↗
PubMed1988

Comparison of methods of analysis using data of the panel study of the Federal Institute for Population Research (BIB).

The author compares methods of analysis using data from a panel study of the Federal Republic of Germany's Institute for Population Research. "This does not only involve a comparison of the methods as such, but above all also a comparison of the results (of these methods), of their presentation and of the possibilities of interpreting them. The three programmes selected for this paper represent methods for...so-called multivariate analysis, in particular for the analysis of non-metric data as they are included in the panel study...." Data are for a sample of 1,868 women interviewed at least twice and concern women's educational status and the qualities of motherhood.

Developed Countries↗
PubMed2005

Comparison of protein and peptide prefractionation methods for the shotgun proteomic analysis of Synechocystis sp. PCC 6803.

Proteome analysis by gel-free "shotgun" proteomics relies on the simplification of a peptide mixture before it is analyzed in a mass spectrometer. While separation on a reverse-phase (RP) liquid chromatographic column is widely employed, a variety of other methods have been used to fractionate both proteins and peptides before this step. We compared six different protein and peptide fractionation workflows, using Synechocystis sp. PCC 6803, a useful model cyanobacterium for potential exploitation to improve its production of hydrogen and other secondary metabolites. Pre-digestion protein separation was performed by strip-based isoelectric focusing, one-dimensional polyacrylamide gel electrophoresis, or weak anion exchange chromatography, while pre-RP peptide separation was accomplished by isoelectric focusing (IEF) or strong cation exchange chromatography. Peptides were identified using electrospray ionization quadrupole time of flight-tandem mass spectrometry. Mass spectrometry (MS) and tandem mass spectra were analyzed using ProID software employing both a single organism database and the entire NCBI non-redundant database, and a total of 776 proteins were identified using a stringent set of selection criteria. Method comparisons were made on the basis of the results obtained (number and types of proteins identified), as well as ease of use and other practical aspects. IEF-IEF protein and peptide fractionation prior to RP gave the best overall performance.

Chromatography, High Pressure Liquid↗
PubMed1994

Nonuniform sampling of urodynamic signals: a comparison of different methods.

Several different techniques for urodynamic signal compression have been proposed in the last few years. Using these techniques it is possible to reduce the requirements for digital storage or transmission. There are a number of applications where it is essential to use such techniques in diagnostic and ambulatory urodynamics. The purpose of this study is to compare different techniques of urodynamic data compression. The so-called FAN, voltage triggered, two point projection and second difference methods. The comparison between the methods is based on 65 pressure, 46 uroflow and 18 surface electromyogram signals. The reduction ratio achieved for different allowable errors between the original and compressed signals is calculated and compared for the different techniques. Results show that it is possible to store urodynamic signals accurately at a low sampling rate, where FAN and voltage triggered methods seem to be superior to the rest.

Algorithms↗
PubMed1997

A comparison of methods of botulinum toxin injection for abductory spasmodic dysphonia.

Treatment of abductory spasmodic dysphonia with botulinum toxin injection into the posterior cricoarytenoid muscles often results in only partial symptom relief. In contrast, excellent results can be achieved after thyroarytenoid injection for the adductory type of spasmodic dysphonia. One reason for disappointing results may be inaccurate placement of the botulinum toxin into the posterior cricoarytenoid muscles. We describe a new approach to posterior cricoarytenoid injection used in 18 patients for treatment of abductory spasmodic dysphonia. Of the 30 patients treated for abductory spasmodic dysphonia at Loyola University-Chicago, 6 underwent both a retrocricoid approach and the newer transcricoid method, thus allowing patient and clinician comparison of techniques. We and all six of our patients preferred the transcricoid approach because of less discomfort, equivalent or better voice results, and fewer side effects.

Adult↗
PubMed2001

Clinical evaluation of a new non-isotopic leptin immunoassay.

OBJECTIVE: Evaluate the new Active human leptin ELISA available through Diagnostic Systems Laboratories Inc for use in clinical research laboratories. DESIGN: Fasting plasma samples for this study were obtained randomly from human subjects. Precision, linearity, recovery, and interference studies were performed, in addition to method comparison with the conventional leptin RIA method and comparison between laboratories. SETTING: University of Hawaii at Manoa, Division of Medical Technology and the Native Hawaiian Health Research-RCMI laboratory. PARTICIPANTS: Native Hawaiians were selected for this study since this population has consistently demonstrated a higher incidence rate of obesity and Type 2 diabetes and thus, potentially have high leptin levels. RESULTS: At leptin concentrations of 2.3, 16.6, and 45.6 ng/ mL, within-run imprecision (n = 5) ranged from 3.1%, 1.6%, and 4.2%, and the between-run imprecision (n = 10) ranged from 6.8%, 4.1%, and 2.7%. The comparison-of-method gave a linear regression equation of y = 0.92x + 1.6 mg/dL (r = 0.96, n = 74, S(y/x) 2.0) when compared to the Linco human leptin RIA method. The dilution curve showed acceptable linearity within the reportable range of the assay, and the recovery was 88.5% to 112%. No interference was detected with hemoglobin up to 1 g/dL, and with triglyceride, up to 1.8 g/dL. However, bilirubin, 10 mg/dL, did show significant interference. CONCLUSION: Overall, we feel that the new Active Human Leptin assay offers a safe and rapid alternative method appropriate for clinical research laboratories and epidemiological studies.

Enzyme-Linked Immunosorbent Assay↗
PubMed2003

Methods for comparison of parameters from longitudinal rhythmometric models with multiple components.

Multiple components linear least-squares methods have been proposed for the detection of periodic components in nonsinusoidal longitudinal time series. However, a proper test for comparison of parameters obtained from this method for two or more time series is not yet available. Accordingly, we propose two methods, one parametric and one nonparametric, to compare parameters from rhythmometric models with multiple components. The parametric method is based on techniques commonly and generally employed in linear regression analysis. The comparison of parameters among two or more time series is accomplished by the use of so-called dummy variables. The nonparametric method is based on bootstrap techniques. This approach basically tests if the difference in any given parameter obtained by fitting a model with the same periods to two different longitudinal time series differs from zero. This method calculates a confidence interval for the difference in the tested parameter. If this interval does not contain zero, it can be concluded that the parameters obtained from the two time series are different with high probability. An estimation of the p-value for the corresponding test can also be calculated. By the use of similar bootstrap techniques, confidence intervals can also be obtained for any parameter derived from the multiple component fit of several periods to nonsinusoidal longitudinal time series, including the orthophase (peak time), bathyphase (trough time), and global amplitude (difference between the maximum and the minimum) of the fitted model waveform. These methods represent a valuable tool for the comparison of rhythm parameters obtained by multiple component analysis, and they render this approach as a generally applicable one for waveform representation and detection of periodicities in nonsinusoidal, sparse, and noisy longitudinal time series sampled with either equidistant or unequidistant observations.

Blood Pressure↗
PubMed1983

Albumin determination with bromocresol purple: imprecision, comparison of methods and quality control.

The bromocresol purple methods for the determination of serum albumin on the Du Pont aca and on the KONE CD show very acceptable linear ranges and imprecision data. Comparison of methods showed good agreement between albumin determinations on the two instruments. Human based quality control materials are required in order to monitor the accuracy of bromocresol purple methods, and to obtain results that are independent of method or instrument. Assigned values in assayed controls and external quality control schemes based on the bromocresol green method are not suitable.

Autoanalysis↗
PubMedDate not supplied

[A method of comparison of DNA polynucleotide sequences].

The results of a comparative analysis of the kinetic curves of reassociation of DNA of closely related species of Microtus (Microtus arvalis, Microtus oeconomus oeconomus, Microtus oeconomus Chachlovi) are presented. A five power polynomial was used as a mathematical model of the kinetic DNA reassociation curves. The values of polynomial coefficients and the theoretical value, both with statistical deviations dispersion, have been estimated with the help of a standard computer programme. The modified Fischer criterium was used for comparing the model kinetic curves of reassociation of the above species and of subspecies of Microtus, and to estimate the significance of the difference between two random means. A pair-wise comparison of the model curves shows that the similarity of the DNA polynucleotide sequences in two subspecies is less expressed than in two species of Microtus. A method of comparison of DNA nucleotide sequences is suggested on the basis of mathematical models of kinetic curves of DNA reassociation.

Animals↗
PubMed2005

A pooled analysis to evaluate results of capsule endoscopy trials.

BACKGROUND AND STUDY AIM: Capsule endoscopy is a new tool in the evaluation of the small intestine. To speed evaluation and acceptance of this technology, the manufacturer (Given Imaging Ltd, Yoqneam, Israel) funded several trials. The data from these trials were collected at a central repository using a standardized reporting tool. Presentation of this data to the US Food and Drug Administration (FDA) in July 2003 led to the removal of the adjunctive term with regard to indication for capsule endoscopy, recognizing that the method is of independent importance for evaluating the small bowel. The aim of the present study was to combine the data from several capsule trials to help determine the yield and miss rate of capsule endoscopy for different diseases, compared with alternative diagnostic modalities. METHODS: Capsule studies were identified from a master database of funded studies. Studies were included in the pooled analysis if they reported a prospective comparison with another modality for evaluation of the small intestine. RESULTS: 32 studies with a total of 691 patients were found in the master database, of which 24 studies, representing 530 patients, met inclusion criteria and were entered into the pooled analysis. Prior to study entry, patients had undergone a mean of 6.77 diagnostic procedures, without findings. Of these 24 studies, 14 (involving 310 patients) were categorized as "bleeding" studies, and 10 studies (220 patients) as "nonbleeding small-bowel disorders" studies. The comparison procedure was push enteroscopy in 300 patients (in 45 for nonbleeding disorders), small-bowel series in 140 patients (in 125 for non-bleeding disorders), and colonoscopy with ileoscopy in 90 patients (50 for nonbleeding disorders). Overall analysis per patient showed new findings from capsule endoscopy in 50 % of patients; 17 % had new findings from the comparison method; in 22 % there were similar findings; and in 11 % there were no findings. A total of 1349 instances of disease were identified in the 530 examinations. Capsule endoscopy solely detected 87 % of the disease instances, while the comparison method solely detected 13 %. The yield for push enteroscopy alone was 14.8 %, for small-bowel series it was 9.9 %, and for colonoscopy it was 13.2 %. Capsule endoscopy missed 146 disease instances for a miss rate of 10 %; 989 were missed by the comparison methods for a miss rate of 73 %; and 214 were detected by both methods. CONCLUSION: Capsule endoscopy is the state of the art method for noninvasive detection of small-bowel disease.

Adolescent↗