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PubMedDate not supplied

[Results of two methods for testing bacterial susceptibility to antibiotics: disk method and a new semi-automatic method in liquid medium (ABACR procedure) and comparison with the minimal inhibitory concentration (author's transl)].

A performance analysis was established between three methods for testing of bacterial susceptibility to sixteen antibiotics: agar dilution or minimal inhibitory concentration (MIC) method, agar diffusion or DISK method, and semi-automatic dilution in liquid medium or ABACR method. Precision of the three methods was determined using three reference strains in repetition experiments (9 repetitions for MIC, 60 repetitions for both DISK and ABAC). The results show that MIC method was the most precise, and that the precision of DISK and ABAC methods was not sifnificantly different. Fidelity of both DISK and ABAC methods was compared in taking as reference the MIC of 200 wild strains of Gram-negative bacteria. Omitting the data concerning trimethoprim-sulfamethozoaxol, the results were found concordant between DISK and MIC methods in 68.6 percent of the cases, between ABAC and MIC methods in 73.6 percent, and between ABAC and DISK methods in 68.9 percent. With regard to MIC, ABAC method gave results slightly better than those of DISK method, especially for five antibiotics: gentamicin, minocyclin, doxycylin, chloramphenicol and polymyxin B. So, the ABAC method looks very interesting for a semi-automatic routine method in testing bacterial susceptibility to antibiotics.

Anti-Bacterial Agents↗

PubMedDate not supplied

Single cuff comparison of two methods for indirect measurement of arterial blood pressure: standard auscultatory method versus automatic oscillometric method.

With the introduction of automatic oscillometric systems for indirect measurement of arterial blood pressure (e.g. DINAMAP), the problem of correspondence between that method and the standard auscultatory method arose. For an exact and valid comparison of two methods, for physiological and methodological reasons, both measurements have to be performed simultaneously and using only one single cuff. Applying a methodological approach fulfilling these preconditions and offering in addition the advantage of a graphic documentation of the individual measurement cycles, we were able to investigate both methods in a sample of 216 comparative experiments. We found a mean difference (auscultatory method minus oscillometric method) between the methods (bias) of -0.82 mm Hg (-0.109 kPa) for systolic pressure, 1.25 mm Hg (0.166 kPa) for diastolic pressure and 1.00 mm Hg (0.133 kPa) for mean pressure. Except for systolic pressure, the differences were statistically significant (paired t-test and analysis of variance). We also obtained a significant negative correlation between the differences and the average of both pressure values (decreasing error with increasing pressure) and a significant negative correlation between differences and heart rate (decreasing differences with increasing heart rate). The conclusions drawn from the comparative study are that, although the oscillometric method exhibited a tendency to higher systolic and lower diastolic measurement values compared to the auscultatory method, both methods are well comparable and the differences are below the level of physiological and clinical significance.

Blood Pressure Determination↗

PubMed1988

Evaluation of several creatinine methods in search of a suitable secondary reference method: report from the subcommittee on reference method for creatinine, Nordic Society for Clinical Chemistry.

Several methods for creatinine have been examined by the subcommittee on reference method for creatinine. These include the use of picric acid to precipitate proteins followed by alkalization, or the use of alkaline picrate after protein precipitation and adsorption to Fuller's earth. The first approach was not found to be suitable as a reference method since it was susceptible to matrix effects, fluctuations in temperature and wavelengths. The second approach was less sensitive to these effects but showed variations with different batches of Fuller's earth. The method using high performance liquid chromatography (HPLC) had poor precision, probably because endogenous compounds co-eluted either with creatinine or with the internal standard. The enzymatic method based on the determination of hydrogen peroxide had good accuracy and precision. However, the main disadvantage is that the method is sold as a kit and detailed specifications concerning all the ingredients are not available to permit independent studies using the basic components.

Chromatography, High Pressure Liquid↗

PubMed1978

[Comparison of two methods of antibiotic sensitivity tests: gel diffusion and automatic method using ABAC apparatus. I. Variation and dispersion of the two methods (author's transl)].

The authors studied comparatively the sensitivity of 3 bacterial strains (P. Aeruginosa and two E. coli) with regard to antibiotics using an automatic method (ABAC) compared with a gel diffusion technic with impregnated disks. Each strain was tested by both methods 50 to 55 times. The diffusion method was easily reproducible with an average standard deviation of 2.23 mm. Its results were in agreement compared with the average diameter of measurements in 93.3% of cases. The automatic method gave results which agreed together in 95.7% of cases. It is thus reproducible. If one compares it with the results of the diffusion method, considered here as the reference method, we obtained the same response in 86.3% of cases. In 13.7% there was disagreement in interpretation (in most cases, the strain found intermediate in gel diffusion was considered sensitive on autoanalysis).

Anti-Bacterial Agents↗

PubMed1979

[Determination of Li, Na, K, Mg and Ca with a mechanised flame photometric micro-method. Mechanised micro-method ("injection method") of flame photometry (atomic absorption--atomic emission) for the determination of serum electrolytes and trace elements (Fe, Cu, Zn); Part I. (author's transl)].

By introduction of the analysis solution in measured quantities in atomic absorption and atomic emission spectrometry, the quantity sensitivity of these methods can be increased by an order of magnitude, while the concentration sensitivity remains unchanged. The required volume of sample (serum) is thereby considerably reduced. Using this method, the serum electrolytes and certain trace elements can be determined simply and quickly in only a few microlitres of serum. The automation of this micro-sample application ("injection method") largely abolishes individual errors, and markedly shortens the time for the analysis of large series of samples. The first part of this paper describes the determination of serum electrolytes and lithium, using only 5--20 microliters of serum.

Calcium↗

PubMedDate not supplied

Comparison of a quantitative microtiter method, a quantitative automated method, and the plate-count method for determining microbial complement resistance.

A quantitative microtiter method for determining the degree of complement resistance or sensitivity of microorganisms is described. The microtiter method is compared with a quantitative automated system and the standard plate-count technique. Data were accumulated from 30 avian Escherichia coli isolates incubated at 35 C with either chicken plasma or heat-inactivated chicken plasma. Analysis of data generated by the automated system and plate-count techniques resulted in a classification of the microorganisms into three groups: those sensitive to the action of complement; those of intermediate sensitivity to the action of complement; and those resistant to the action of complement. Although the three methods studied did not agree absolutely, there were statistically significant correlations among them.

Animals↗

PubMed1975

[Comparative studies of the initial rate method (modified Centrifi Chem method) and the Frankonit method to assay creatinine in serum and urine (author's transl)].

In the method described, by modification of the measurement according to changing reagent blanks (7 g albumin/100 ml + reagent for serum, and water + reagent for urine), excellent agreement with the results obtained by the Frankonit method was found. 262 parallel determinations with serum and 103 with urine were carried out. With a correlation of 0.99, the regression line y = x was almost maintained.

Creatinine↗

PubMed1991

[Clinical and experimental studies on gastrointestinal motility following total colectomy: direct measurement (strain gauge force transducer method, barium method) and indirect measurement (hydrogen breath test, acetaminophen method)].

In a clinical study, we examined the clinical assessment of bowel function and lactulose hydrogen breath test in 14 patients after total colectomy. All patients within one year after ileostomy closure had 'poor' function and showed no increase of hydrogen breath gas concentration. 10 of 12 patients more than one year showed increase of hydrogen breath gas concentration, and 8 of them had 'fair' function. The oro-neorectal transit time (ONTT) in 'poor' group was shorter than in 'fair' group and control (p less than 0.05). The increase of hydrogen breath gas suggests changes of bacterial flora and colonization of the remained ileum. In an experimental study, we performed subtotal colectomy with the J-pouch reservoir in 11 dogs. We examined ONTT with barium method, gastric emptying with acetaminophen method, and gastrointestinal motility with strain gauge force transducers. Although ONTT at one month after operation had been shorter than control, ONTT at 3 and 6 months became longer than at one month. The gastric emptying after subtotal colectomy was significantly slower than control. Although the propagation velocity of interdigestive migrating complex (IMC) in the jejunum and ileum at 2 weeks had been faster than control, the velocity at 4 weeks and 3 months became slower than at 2 weeks. The frequency of IMC and prolonged propagated contraction in the J-pouch reservoir decreased. The specimen of J-pouch reservoir resected at 6 months showed villous atrophy, crypt elongation, decrease of muscle layers thickness and disappearance of solitary follicles. Therefore, the suppressed motility in each sites of the gastrointestinal tract, increase of anaerobic and colonization of the ileum implied 'adaptation' after total colectomy.

Acetaminophen↗

PubMed1989

Comparison of conventional staining methods and monoclonal antibody-based methods for Cryptosporidium oocyst detection.

The sensitivity and specificity of seven microscopy-based Cryptosporidium oocyst detection methods were compared after application to unconcentrated fecal smears. The seven methods were as follows: (i) a commercial acid-fast (AF) stain (VOLU-SOL) method, (ii) Truant auramine-rhodamine (AR) stain method, (iii) fluorescein-conjugated C1B3 monoclonal antibody (MAb) direct fluorescence method, (iv) OW3 MAb indirect fluorescence method, (v) biotinylated OW3 indirect fluorescence method, (vi) biotinylated OW3-indirect diaminobenzidine (DAB) method, and (vii) biotinylated OW3-aminoethylcarbazole (AEC) method. A total of 281 randomly collected Formalin-fixed fecal samples (submitted to the Maricopa County Health Department, Phoenix, Ariz.) and 30 known positives (Formalin-fixed and K2Cr2O7-preserved stools from our laboratory) were examined in a blind test; 32 of 311 samples (10.3%) were confirmed positive. Of the confirmed positives, 40.6% were identified by the AF method, 93.8% were identified by the AR method, 93.8% were identified by the C1B3 method, 81.3% were identified by the OW3-DAB method, 71.9% were identified by the OW3-AEC method, 100% were identified by the OW3 indirect fluorescence method, and 100% were identified by the biotinylated OW3 indirect fluorescence method. False-positives were encountered by the AF and AR methods (52.0 and 85.7% specificity, respectively), while no false-positives encountered by the MAb-based methods. Oocysts in infected tissue sections were easily detected by the MAb-based methods.

Animals↗

PubMed1991

Allocation of patients to paucibacillary or multibacillary drug regimens for the treatment of leprosy--a comparison of methods based mainly on skin smears as opposed to clinical methods--alternative clinical methods for classification of patients.

This paper reports on the experience with classification of patients at the All-Africa Leprosy and Rehabilitation Training Centre (ALERT) in the Shoa Province in Ethiopia. Classification on clinical grounds is compared with classification which is primarily based on the result of skin-smear examinations. In addition, possible alternative clinical methods for the allocation of patients to the multidrug therapy (MDT) regimens are discussed. The analysis includes 1525 new patients. In 730 patients classified clinically as paucibacillary (PB), this classification was not confirmed by skin-smear results in only 1.5%; whereas in 795 patients classified clinically as multibacillary (MB), the classification was not confirmed in 21.1%. Possible reasons, notably for the latter discrepancy, are discussed. Based on an assessment of the correctness of the diagnosis and the most probable classification, it was found that if classification had been based on the skin-smear results, 9.3% of the 795 patients classified as MB would have been classified incorrectly as PB. Classification based on clinical signs resulted in incorrect classification, MB instead of PB, of 8.7% of the 795 patients. Over-classification of MB patients, which was found to be supervisor related, is open to improvement by a strict application of clinical criteria for classification. The experience in the ALERT leprosy control program shows that classification which is based on clinical signs may, in particular, result in some PB patients being classified as MB, while classification based on the results of skin-smear examinations is more likely to result in some MB patients being classified as PB. It was concluded that, provided a number of requirements aimed at limiting the number of misclassified patients are introduced, patients can be classified based on clinical signs and, hence, in the absence of skin-smear services for routine classification purposes.

Drug Therapy, Combination↗

PubMed1990

Gallbladder volume and contraction measured by sum-of-cylinders method compared with ellipsoid and area-length methods.

Gallbladder volume, determined by ultrasonography (US) using the sum-of-cylinders (SOC) method, is tedious and time-consuming. We therefore examined whether ellipsoid (ELL) or area-length (A-L) methods, which are easier to perform, could reliably replace the SOC method. Fasting gallbladder volume and emptying were determined according to these 3 methods in 20 normal subjects and 20 gallstone patients. Excellent correlations were found but the ELL method yielded significantly larger mean volumes and the A-L method revealed significantly smaller volumes than the SOC method. Analysis of differences between methods revealed a considerable lack of consistency. Volumes according to the ELL method were 35 percent larger to 46 percent smaller for normal subjects and 34 percent larger to 41 percent smaller for gallstone patients than volumes according to the SOC method. Volumes according to the A-L method were 35 percent larger to 15 percent smaller for normal subjects and 51 percent larger to 17 percent smaller for gallstone patients. Maximal decrement of gallbladder volume in ml and in percentage according to the 3 different methods did not differ. Regardless of the method used, both fasting and minimal gallbladder volumes were significantly larger in gallstone patients than in normal subjects, whereas maximal decrement of gallbladder volume in ml and percentage was not different. The present study indicates that the SOC method remains the method of choice for US determination of gallbladder volume for scientific purposes.

Adult↗

PubMed1991

[Direct integral linear least square regression method for kinetic evaluation of hepatobiliary scintigraphy: theory, basic analysis and comparison with non-linear least square regression method].

In hepatobiliary scintigraphy, kinetic model analysis, which provides kinetic parameters like hepatic extraction or excretion rate, have been done for quantitative evaluation of liver function. In this analysis, unknown model parameters are usually determined using nonlinear least square regression method (NLS method) where iterative calculation and initial estimate for unknown parameters are required. As a simple alternative to NLS method, direct integral linear least square regression method (DILS method), which can determine model parameters by a simple calculation without initial estimate, is proposed, and tested the applicability to analysis of hepatobiliary scintigraphy. In order to see whether DILS method could determine model parameters as good as NLS method, or to determine appropriate weight for DILS method, simulated theoretical data based on prefixed parameters were fitted to 1 compartment model using both DILS method with various weightings and NLS method. The obtained parameter values were then compared with prefixed values which were used for data generation. The effect of various weights on the error of parameter estimate was examined, and inverse of time was found to be the best weight to make the error minimum. When used this weight, DILS method could give close parameter values to those obtained by NLS method and both parameter values were very close to prefixed values. With appropriate weighting, the DILS method could provide reliable parameter estimate which is relatively insensitive to the data noise. In conclusion, the DILS method could be used as a simple alternative to NLS method, providing reliable parameter estimate.

Biliary Tract↗

PubMed1987

The neighbor-joining method: a new method for reconstructing phylogenetic trees.

A new method called the neighbor-joining method is proposed for reconstructing phylogenetic trees from evolutionary distance data. The principle of this method is to find pairs of operational taxonomic units (OTUs [= neighbors]) that minimize the total branch length at each stage of clustering of OTUs starting with a starlike tree. The branch lengths as well as the topology of a parsimonious tree can quickly be obtained by using this method. Using computer simulation, we studied the efficiency of this method in obtaining the correct unrooted tree in comparison with that of five other tree-making methods: the unweighted pair group method of analysis, Farris's method, Sattath and Tversky's method, Li's method, and Tateno et al.'s modified Farris method. The new, neighbor-joining method and Sattath and Tversky's method are shown to be generally better than the other methods.

Animals↗

PubMed1988

Predicting serum lithium concentration using Bayesian method: a comparison with other methods.

Two pharmacokinetic approaches (single-point Bayesian and two fixed volume of distribution-iterative methods) for predicting serum lithium concentrations in patients treated with lithium carbonate for manic-depressive illness or cyclic neutropenia in Kyushu University Hospital were evaluated and compared retrospectively. Prior to these analyses, three methods (prediction using mean parameters reported by Mason et al., the Pepin method, and the Zetin method) without measuring serum concentrations were also compared. In the Bayesian analysis, the effect of population mean parameters (reported by Mason et al. and Pepin et al.), which were used as initial estimates in a fitting process, on predictive performance was also studied. Forty five patients (21 male, 24 female) were included in this study. The average number of determinations per patient was 6.3, and the sampling times ranged from 2 to 18 h after the last dose. Serum lithium concentrations were measured by atomic absorption spectrometer. The Bayesian method used a computer program (PEDA) developed previously by one of us. The prediction using the population mean values from Mason's report gave the least root mean squared error (RMSE; a composite measure for bias and precision of prediction), and was considered to be the most precise among the methods without measuring serum concentrations. Among the methods using a single measured concentration, the Bayesian prediction was less biased and more precise than that by the two fixed volume of distribution-iterative methods. The Bayesian method reduced prediction error in serum concentration prediction compared with those obtained from population mean parameters in both cases: A high reduction of RMSE was observed when the values from Pepin method were used as initial estimates (from 0.320 to 0.219 meq/l), while, Mason's values gave less reduction (from 0.219 to 0.213 meq/l). In the Bayesian prediction of serum lithium concentration, the selection of population-based initial estimates gave no effect on predictive ability of the Bayesian method in terms of RMSE. In conclusion, the Bayesian method was robust and flexible with regard to dosing schedule, sampling time and number of blood samples, and gave the most clinically acceptable precision among the methods evaluated.

Adolescent↗

PubMed1990

Comparison of five routine methods with the candidate reference method for the determination of bilirubin in neonatal serum.

Using five routine methods and the candidate reference method of Doumas (Clin. Chem. 31, 1779-1789 (1985)), total bilirubin was determined in 77 neonatal serum samples (concentration range 63-444 mumol/l, average value 227 mumol/l). Four of the routine methods (Jendrassik & Grof's (Biochem. Z. 297, 81-89 (1938)) method, Hertz's (Scand. J. Clin. Lab. Invest. 33, 215-230 (1974)) method, the bilirubinometer procedure, and the method employing 2,5-dichlorophenyldiazonium (Scand. J. Clin. Lab. Invest. 29, Suppl. 126, Abstr. 11. 12. (1972]) gave values that were generally higher than those of the reference method. In contrast, the results from Vink's (Clin. Chem. 34, 67-70 (1988] direct spectrophotometric method differed only negligibly from those of the reference method. The accuracy of Jendrassik & Grof's method, and to a limited extent that of the 2,5-dichlorophenyldiazonium method, can be improved by redetermination of the molar absorption coefficient, or by using a standard containing a matrix of human albumin, with an assigned value determined by the reference method. It was found that Hertz's direct spectrophotometric method can be replaced by that of Vink. The accuracy of the bilirubinometer results could be improved only by using calibrators with assigned values specific for the bilimeter, or by calibration with a serum pool.

Bilirubin↗

PubMed1992

[Validity of the proximal isovelocity surface area color Doppler method for calculating the valve area in patients with mitral stenosis; comparison with the two-dimensional echocardiographic method].

BACKGROUND: The proximal isovelocity surface area (PISA) method, assessed by color Doppler echocardiography, has gained acceptance as a means of calculating flow rate through regurgitant orifice. The method can also be used to derive mitral valve area (MVA), by continuity equation, in patients with mitral stenosis (MS). The aim of this study was to compare the PISA method with the two-dimensional echocardiographic planimetry (2D) method and pressure half-time method (PHT) in MVA calculations in a group of 37 patients with MS. METHODS AND RESULTS: All of these patients had satisfactory MVA by 2D method. There were 22 female and 15 male; age 56 +/- 11 years (range 32-71); 19 were in sinus rhythm (SR) and 18 in atrial fibrillation (AF); 17 patients had pure MS, while the remaining 20 had associated mitral regurgitation (MR); in 23 patients the orifice morphology was circular or elliptic, and was defined as regular; while in 14 patients the morphology was irregular for the presence of two or more nodular calcifications on the commissures or leaflet's edges. MVA by PISA method was calculated assuming a uniform radial flow convergence region along a hemispherical surface, according to the formula: MVA = 2 pi r2 Vn(1-cos theta)/Vmax; where r was the PISA radius measured in 2D from the first alias to the mitral leaflet's edge; Vn was the flow velocity at radial distance from the mitral orifice; Vmax was the peak transmitral velocity by CW Doppler; 1-cos theta was a factor that accounted for the inflow angle formed by the mitral leaflets. The Nyquist limit was lowered to 29 cm/sec. Alpha angle formed by the mitral leaflets ranged between 86 degrees and 134 degrees; average 110 degrees +/- 10 degrees. 2D MVA was 1.33 +/- 0.37 cm2; range 0.69-2.2 cm2; PHT MVA was 1.29 +/- 0.34 cm2; range 0.70-2.1 cm2; PISA MVA was 1.18 +/- 0.36 cm2; range 0.47-1.95 cm2. The PISA method underestimates MVA by 0.15 +/- 0.21 cm2, in comparison with the 2D method; and by 0.11 +/- 0.18 cm2 in comparison with PHT method (p ns). The correlation between 2D and PISA MVA was: r = 0.84; p < 0.001; y = 0.83x + 0.06; 95% confidence intervals +/- 0.40 cm2; and between PHT and PISA MVA was: r = 0.79; y = 0.84x + 0.09; p < 0.001; 95% confidence intervals +/- 0.46 cm2. The correlation coefficient was similarly good in patients with SR or AF, and did not significantly change in patients with pure MS or MS+MR; neither did it vary with respect to the orifice morphology (p < 0.001 for all the variables considered), except for the correlation PHT-PISA in the group of patients with irregular orifice morphology (r = 0.70; p = 0.005). The interobserver and intraobserver variability were, respectively: 2.2% and 4.4% for 2D MVA; 3.4% and 3.8% for PHT MVA; 5.2% and 3.5% for the PISA radius; 6.1% and 4.4% for the alpha angle; 10.2% and 7.2% for PISA MVA (F ratio of variances ns). CONCLUSIONS: In conclusion, the PISA method allows accurate assessment of MVA in patients with MS, regardless of cardiac rhythm or additional MR. Moreover, our study suggests that orifice morphology does not affect the accuracy of this method.

Adult↗

PubMed1992

A new method for measurement of femoral anteversion. A comparative study with other radiographic methods.

A new biplanar method of measuring femoral anteversion, which may be considered a modified Magilligan's method, is described. In addition to the true antero-posterior radiograph, a true translateral radiograph is taken, instead of a transcervical lateral radiograph as in the Magilligan method. The acute angles (alpha and gamma) between the long axes of the shaft and neck of the femur on both the antero-lateral and lateral radiographs are measured. The angle (gamma') of anteversion is obtained by the trigonometric formula; tan gamma' = tan/tan alpha. The femoral anteversion in 20 adult dried femora and 40 femora in 20 children was measured by the Magilligan method, the authors' method and the conventional CT method. Compared with direct measurement in the dried femora, it was found that both the Magilligan and the authors' methods tended to overestimate and the CT method tended to underestimate (p < 0.05) the anteversion. In children's femora, a similar trend was observed among the three methods and the measurements by each method differed significantly from the other (p < 0.05). We feed that our method of biplanar measurement of femoral anteversion is more accurate, although probably marginally, than the conventional Magilligan method. It also has some relative advantages in clinical application in that positioning is easier, rotation is better controlled, and less time is consumed.

Adolescent↗

PubMed1991

[Clinical study of new technique for collection of EPS, prostate catheter method--comparison with Meares and Stamey's method].

We newly developed a catheter for expressed prostatic secretions (EPS) collection and examined whether or not EPS can be collected with this catheter without contamination of urethral bacteria. The clinical value of the prostate catheter method was examined in comparison with Meares & Stamey's method. Both prostate catheter and Meares & Stamey's method were performed by crossover method in 11 patients who were highly suspected of chronic prostatitis based on symptoms and physical findings. Three of the 4 cases of bacterial prostatitis on Meares & Stamey's method were diagnosed as bacterial prostatitis by the prostate catheter method, but the remaining one was diagnosed as prostatodynia. One of the 3 cases of non-bacterial prostatitis on Meares & Stamey's method was diagnosed as non-bacterial prostatitis, but the other two cases were diagnosed as urethritis. Four cases of prostatodinia on Meares & Stamey's method were given the same diagnosis by the prostate catheter method. In conclusion, eight of 11 cases received the same diagnosis by the two different method. The remaining three cases were given different diagnosis, but the prostate catheter method gave a more accurate diagnosis. We concluded that the prostate catheter method is useful in the differential diagnosis of bacterial prostatitis and non-bacterial prostatitis.

Adult↗