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 235 records · Page 13Linked to original sources
PubMed1978

Comparison of the conventional lecture method and the self-instruction method for teaching clinical pathology.

Two separate courses in clinical pathology were presented to two groups of second-year medical students. The first (large) group was taught by the conventional lecture method; the other (small) group, by a self-instructional method for roughly half of the course, followed by the conventional lecture method for the second half of the course. The effectivenesses of the two methods were compared, based on performances on the final written examination. It was found that the self-instructional method was as effective as the conventional method in teaching clinical pathology, at least in teaching basic principles and interpretive clinical chemistry, as judged by the performances of the two groups. Surprisingly, the two groups differed significantly in performances on the portion of the course taught by similar methods.

Education, Medical, Undergraduate↗
PubMed1998

Percutaneous dilational tracheostomy: the Ciaglia method versus the Portex [correction of Rapitrach] method.

UNLABELLED: In a prospective study, we performed percutaneous dilational tracheostomy (PDT) using either the Ciaglia method (gradual dilation) or the Portex [corrected] method (single dilation) in 80 patients. We encountered difficulty in dilating the tracheal stoma of three (7.5%) patients in the Ciaglia group because of tight pretracheal fascia. It was difficult to insert the tracheostomy tube in four (10%) patients in the Portex [corrected] group even after appropriate tracheal dilation. However, the tracheal cannulation was successfully completed in all patients in subsequent attempts. The mean time for completion of the procedures, from skin incision to insertion of the tracheostomy tube, was 14+/-5.5 min with the Ciaglia method and 6.5+/-3.5 min with the Portex [corrected] method. PDT with either method has not been associated with clinically significant hemorrhage, infection at the stoma site, or cosmetic deformity. In a follow-up period of 9 mo, none of our decannulated patients presented with clinical tracheal stenosis. Our results indicate that PDT with both methods is as safe and easy to organize and perform as a bedside procedure, obviating the need to transport critically ill patients from the critical care unit. IMPLICATIONS: The tracheas of 80 patients were cannulated through an artificial opening using either the Ciaglia (gradual dilation) or the Portex [corrected] (single dilation) method. Both techniques were successful with no significant complications. After 9 mo of closure of this opening, none of the survivors had significant scarring or narrowing of the trachea.

Adolescent↗
PubMed2000

Producing a full-scale model from computed tomographic data with the rapid prototyping technique using the binder jet method: a comparison with the laser lithography method using a dry skull.

Rapid prototyping using the binder jet method has recently been established and has already produced excellent results in industrial applications. The authors recently developed a technique for producing a full-scale model from computed tomographic (CT) data with the binder jet method as an approach to overcome the shortcomings of the laser lithography method, which is already widely used in medicine. They conducted a comparative investigation of full-scale models made with both techniques using a dry skull to determine the accuracy of the models. It was clearly demonstrated that the accuracy of the binder jet method was high enough to be used in craniomaxillofacial surgery because it was the same as the laser lithography method. This study employed data from the latest helical volume scan computed tomography device using a multidetector. The study showed that the new rapid prototyping technique was satisfactory in terms of speed, cost, installation environment, and accuracy of models, and that detailed shapes and structures can be reproduced well. Because this technique has many advantages over the laser lithography method, it should play a major role in craniomaxillofacial surgery and in other medical fields in combination with advances in CT devices. Although plaster is a more suitable fixation material when the emphasis is on the reproducibility of detailed structures, the binder jet method using starch is extremely useful for simulating operations and determining implant shapes because it allows for the prompt production of models.

Analog-Digital Conversion↗
PubMed1996

A comparison between a PCR method and a conventional culture method for detecting pathogenic Yersinia enterocolitica in food.

The aim of this study was to develop a polymerase chain reaction (PCR) method for the detection of pathogenic Yersinia enterocolitica and to compare it with an official culture method (NMKL-117). Primers were selected for nested PCR directed at the attachment invasion locus, ail, on the bacterial chromosome, as well as at a sequence on the pathogenic marker plasmid, termed virulence factor, virF. The final results obtained by the two methods were similar. However, while the conventional method yielded contradictory data for some steps the PCR method provided unambiguous results. Considerable advantages, i.e. higher sensitivity and specificity of the PCR method, compared with the conventional method for detecting pathogenic Y. enterocolitica, were demonstrated in this study.

Bacterial Outer Membrane Proteins↗
PubMed1996

Comparison of the Equil2 program and other methods for estimating the ion-activity product of urinary calcium oxalate: a new simplified method is proposed.

BACKGROUND: We aimed to develop a new simplified method to determine the urinary calcium-oxalate saturation. METHODS: The ion-activity product (AP) of urinary calcium oxalate was estimated in 345 clinical urine specimens (all 2.5 hour collections) using the Equil2 computer program and several other methods, and the results were compared. A new index using 4 parameters was created using multiple regression analysis. RESULTS: Our new simplified method (the AP(CaOx) index EQ2) provided a better approximation to the Equil2 method (r = 0.9897) than other conventional methods. CONCLUSION: This new method requiring 4 factors (urinary calcium, magnesium, oxalate, and citrate concentrations) is simple and clinically usable.

Calcium Oxalate↗
PubMed1996

A regression method including chronological and bone age for predicting final height in Turner's syndrome, with a comparison of existing methods.

A total of 235 measurement points of 57 Dutch women with Turner's syndrome (TS), including women with spontaneous menarche and oestrogen treatment, served to develop a new Turner-specific final height (FH) prediction method (PTS). Analogous to the Tanner and Whitehouse mark 2 method (TW) for normal children, smoothed regression coefficients are tabulated for PTS for height (H), chronological age (CA) and bone age (BA), both TW RUS and Greulich and Pyle (GP). Comparison between all methods on 40 measurement points of 21 Danish TS women showed small mean prediction errors (predicted minus observed FH) and corresponding standard deviation (ESD) of both PTSRUS and PTSGP, in particular at the "younger" ages. Comparison between existing methods on the Dutch data indicated a tendency to overpredict FH. Before the CA of 9 years the mean prediction errors of the Bayley and Pinneau and TW methods were markedly higher compared with the other methods. Overall, the simplest methods--projected height (PAH) and its modification (mPAH)--were remarkably good at most ages. Although the validity of PTSRUS and PTSGP remains to be tested below the age of 6 years, both gave small mean prediction errors and a high accuracy. FH prediction in TS is important in the consideration of growth-promoting therapy or in the evaluation of its effects.

Adolescent↗
PubMed1999

Fluconazole susceptibilities of bloodstream Candida sp. isolates as determined by National Committee for Clinical Laboratory Standards method M27-A and two other methods.

The in vitro activity of fluconazole against 143 Candida spp. obtained from the bloodstreams of 143 hospitalized patients from 1995 to 1997 was studied. Susceptibility tests were carried out by two macrodilution methods, the M27-A and a modified M27-A method (0. 165 M, pH 7/morpholinepropanesulfonic acid-buffered RPMI 1640 medium supplemented with 20 g of D-dextrose per liter), and by the agar diffusion method (with 15-microg fluconazole [Neo-Sensitab] tablets). With 2 microg of fluconazole per ml, 96.92% of 65 C. albicans isolates, 86.2% of 58 C. parapsilosis isolates 7 of 8 C. tropicalis isolates, and 1 of 6 C. glabrata isolates were inhibited. Only one strain of C. albicans and one strain of C. tropicalis were resistant. The agreement between the two macrodilution methods was greater than 90% within +/-2 log2 dilutions for all strains except C. glabrata (83.3%) and C. tropicalis (87.5%). Generally, MICs were 1 log2 dilution lower in glucose-supplemented RPMI 1640 medium. No correlation between zone sizes and MICs was found. All strains susceptible by the diffusion test were susceptible by the dilution method, but the converse was not necessarily true. Interestingly, inhibition zones were smaller for C. albicans, for which the geometric mean MIC was 0.29 microg/ml and the mean inhibition zone diameter was 25.7 mm, while for C. parapsilosis the geometric mean MIC was 0.96 microg/ml and the mean inhibition zone diameter was 31. 52 mm. In conclusion, the two macrodilution methods give similar results. The modified M27-A method with 2% dextrose has the advantage of shortening the incubation time and simplifying the endpoint determination.

Antifungal Agents↗
PubMed1976

A comparative study of the Bessey method and Hausamen method for serum alkaline phosphatase determination.

The methods of Bessey et al. and Hausamen et al. for serum alkaline phosphatase determination were compared. Determinations were carried out using sera from healthy blood donors and sera from patients suffering from different hepatobiliary diseases. A high reproducibility of values obtained using both methods was noted. The sensitivity of the method of Hausamen et al. is about four times greater than that of the method of Bessey et al., even though the former method employed a lower reaction temperature. A high degree of correlation exists between the two methods and the data reported indicate that both methods are completely valid.

Adult↗
PubMed1991

Collagen-gel-embedded three-dimensional culture of human thyroid epithelial cells: comparison between the floating sandwich method and the dispersed embedding method.

Human thyroid epithelial cells were isolated from surgically resected human thyroid gland with collagenase and cultured for one week under EGF-supplemented conditions to allow them to proliferate. Then the cells were transferred to the following three-dimensional culture systems. One was a culture of isolated cells between floating double layers of collagen gel, designated the "floating sandwich method." The other was a culture of isolated cells mixed with collagen gel, designated the "dispersed embedding method." Many folliclelike structures with lumina of appreciable size were obtained by the former method. The cells cultured by the floating sandwich method exhibited a distinct polarity shown by the presence of numerous microvilli at the apical surface and close contact with collagen gels at the basal surface. On the other hand, only a few folliclelike structures were obtained by the dispersed embedding method, in which the folliclelike structures were small in size and the cells showed less distinct polarity than those observed in the floating sandwich method. Thus, the floating sandwich method appears to be suitable for studying the process and mechanism of in vitro organization of follicular structures by human thyroid epithelial cells.

Cell Division↗
PubMed1990

Particle design of tolbutamide by the spherical crystallization technique. III. Micromeritic properties and dissolution rate of tolbutamide spherical agglomerates prepared by the quasi-emulsion solvent diffusion method and the solvent change method.

With the objective of modifying the micromeritic properties of tolbutamide (i.e., to manufacture a highly functional powder form), particle design was attempted using a quasi-emulsion solvent diffusion (QESD) method, and the micromeritic properties and dissolution rate of the obtained spherical agglomerates were evaluated by comparison with agglomerates prepared by the solvent change (SC) method. For the production of tolbutamide agglomerates by the QESD method, a necessary condition was the addition of a sucrose fatty acid ester to the system as an emulsifying agent. The particle diameter of the agglomerates obtained by the QESD method depended on the size of the initially formed quasi-emulsion droplets, which in turn depended on the viscosity of the solution. In addition, the agglomerates were nearly perfectly spherical in shape. In the QESD method, the quasi-emulsion droplets crystallized instantaneously from the droplet surface inward. The resultant agglomerates were dense, had great mechanical strength and showed excellent flowability due to their perfect spherical shape. On the other hand, the agglomerates produced by the SC method were conglomerates of primary crystals, and fine, needle-like crystals formed on their surface. As a result, these agglomerates had a large specific surface area, and they therefore showed greater solubility than the agglomerates prepared by the QESD method.

Chemistry, Pharmaceutical↗
PubMed1992

[Development of a new method for calibration of pneumotachograph according to flow rate--evaluation of a computer-controlled-system for assessing respiratory gas exchange using this method].

1) We evaluated the method for calibrating the pneumotachograph according to flow rate by the software on personal computer. Flow volume was detected using the approximated equation (y = 1.294x2 + 0.989x + 35.824, r = 0.976, p less than 0.01) from various mean flow rate and integration of output voltage. The error between syringe volume (21) and the estimated value on the equation was 10 +/- 8 ml (0.48 +/- 0.42%). 2) Using the method described in 1), we developed computer-controlled-system for assessing respiratory gas exchange by mixing chamber method. To evaluate the accuracy of the system as compared with the Douglas Bag method, we measured the gas parameters of the both methods for two male subjects at rest(3 and 5min) and steady state exercise (3 min., 60-240watt). The error between the both methods were within +/- 5% in ventilation(VE), mixed expired O2 (FEO2) and CO2 (FECO2) concentration, and were within +/- 8% in O2 uptake(VO2) and CO2 production (VCO2). There were high positive correlation (r greater than 0.99, p less than 0.01) between the both methods in the all parameters. These results indicate that the system in this study would be practical use, that VE can be measured in only one pneumotachograph, even if the range of flow rate was wide(e.g. from rest to heavy exercise).

Adult↗
PubMed1987

Comparative study of colorimetric method using diazotization reaction and high-performance liquid chromatographic method in determination of para-aminohippuric acid.

In this study, colorimetric method and high-performance liquid chromatographic (HPLC) method were improved and established, respectively, in order to minimize analytical errors in determination of para-aminohippuric acid (PAH) in rat urine and plasma. In terms of the colorimetric method, an operative step following addition of Tsuda reagent was modified as follows: after the addition of Tsuda reagent, reaction mixture was kept at 40 degrees C for 70 min before spectrophotometry. Linearities were observed both in the higher range of 0 and 2.5 to 12.5 micrograms and in the lower range of 0 and 100 to 1,000 ng per test tube, and its practical detection limit was 100 ng per test tube. In terms of HPLC method, using a reversed-phase column (Nucleosil 5 C18), PAH was separated by a mobile phase of acetonitrile/50 mM KH2PO4 (pH 2.8) = 9/95. Linearities were observed in the higher range of 0 and 10 ng to 2 micrograms and in the lower range of 0 and 1 to 10 ng per injection, and its practical detection limit was 1 ng per injection. These results denote that the above two methods are applicable to routine PAH determination. In addition, our HPLC method is considered to be applicable to microassay of PAH, because its sensitivity is more sensitive and minimization of volume system is more easily achieved as compared with the colorimetric method.

Aminohippuric Acids↗
PubMed1999

Heart rate monitoring as a field method for estimating energy expenditure as evaluated by the doubly labeled water method.

Energy expenditure (TEE) determined by the doubly labeled water technique (DLW) in 10 adult subjects (5 males and 5 females) was used to evaluate the energy expenditure estimated from 24 h heart rate monitoring records (HR method) for 2 d randomly sampled during 2 weeks of DLW study. Individual data on HR and oxygen consumption, obtained during a step test (resting conditions, and up and down at 3 or 4 stepping rates) and postabsorptive conditions (resting metabolic rate: RMR), were used to calculate three types of calibration regression line, i.e., straight-linear regression (EE-HR: A for TEEhr-A), log-linear regression (lnEE-HR: B for TEEhr-B), and two-linear regression (flex-HR method: C for TEEhr-C). When the 24 h HR records were applied, these calibration regressions provided three estimates of TEE (mean +/- SD kcal/24 h): TEEhr-A (3,059 +/- 1,246 in all subjects), TEEhr-B (2,472 +/- 843), and TEEhr-C (2,759 +/- 1,228). Mean TEE determined by the DLW method (TEEdlw) was 2,544 +/- 378 kcal/24 h. Although no mean values estimated by HR methods were significantly different statistically from the mean value of TEEdlw, the variances of the estimates (e.g., SD) by the HR method were much greater than that of TEEdlw (between twofold and threefold). TEEhr-B estimated by lnEE-HR regression provided the smallest differences from that of TEEdlw (mean difference of -3.1% with a range of -35.1(-)+36.6%). From these observations, the following conclusions were made: 1) The estimates of TEE by HR are useful as a group mean, but interpretation of the individual TEE estimates requires caution because of great deviations from the reference values. 2) Among the calibration methods tested, the log-linear calibration regression (lnEE on HR) gives the best estimates of TEE by the HR method and is recommended for use in future studies.

Adolescent↗
PubMed1998

Comparison of the SimPlate total plate count method with Petrifilm, Redigel, conventional pour-plate methods for enumerating aerobic microorganisms in foods.

The SimPlate Total Plate Count (TPC) method, developed by IDEXX Laboratories, Inc., is designed to determine the most probable number of aerobic microorganisms in foods. The 24-h test was compared to the conventional plate count agar (PCA) method, the Petrifilm Aerobic Count plates, and the Redigel Total Count procedure for enumerating microflora in 751 food samples. Results using the SimPlate TPC method were highly correlated (r > or = 0.96) with results from other test methods. Slopes (0.96-0.97) were not significantly different from 1, and y intercepts (-0.03-0.08) were not different from O. The SimPlate has a high counting range (> 1600 most probable number per single dilution), thus requiring fewer dilutions of samples compared to other methods evaluated. Some foods, e.g., raw liver, wheat flour, and nuts, contain enzymes that gave false-positive reactions on SimPlates. Overall, however, the SimPlate TPC method is a suitable alternative to conventional PCA, Petrifilm, and Redigel methods for estimating populations of mesophilic aerobic microorganisms in a wide range of foods.

Aerobiosis↗
PubMed1999

[Comparison of LDL-C values measured with the automated method and the ultracentrifugation method in severe hypertriglyceridemia, and prevalence and life-style of patients with hypertriglyceridemia].

The correlation between LDL-cholesterol (LDL-C) values assayed by the direct method and the ultra-centrifugation method is reported good in normal to moderate hypertriglyceridemia, but it is not clear in severe hypertriglyceridemia. We examined such a correlation in mild (triglycerides, 150-400 mg/dl; n = 3) and severe (> or = 800 mg/dl, n = 9) hypertriglyceridemia. The bias of LDL-C determined by the direct method in comparison with the ultracentrifugation method was from -1.1% to 3.4% and from -49.5% to 15.7% in mild and severe hypertriglyceridemia, respectively. The prevalence of severe hypertriglyceridemia was only 0.2% both in hospital patients and in company workers. Data analyses of company workers indicated that people with severe hypertriglyceridemia have a higher body-mass index, consume more alcohol, smoke more, and exercise less than those with a normal level of triglycerides. These results suggest that there is not a good correlation between LDL-C values assayed by the direct method and the ultracentrifugation method in severe hypertriglyceridemia; but that the direct method can be used for the clinical examination of LDL-C, because of the very low prevalence of severe hypertriglyceridemia. Patients with severe hypertriglyceridemia should improve their life-style as soon as possible.

Adult↗
PubMed1999

[Changes of body fat mass determined by be-electrical impedance and by anthropometry: BMI method and skinfolds method in overweight and obese women after implementation of low energy diet].

OBJECTIVE: To estimate the effect of a low energy diet on body fat mass measured by bioelectrical impedance (BIA) in overweight (BMI > or = 25 < 30) and obese women (BMI > or = 30). DESIGN: Randomised six weeks trial. METHODS: The studied group consisted of 86 women aged 20-67 attended the Outpatients Clinic of Metabolic Disorders. Dietary assessments were performed by 24-hour dietary recall. Body fat mass was measured by bioelectrical impedance method and by skinfolds thickness method. Percent body fat and fat free mass was estimated from equations based on BMI and skinfolds thickness. RESULTS: In overweight women after 6 weeks of dietary treatment mean intake of energy decreased from 10071 +/- 2678 kJ to 4560.6 +/- 1405.8 kJ, total fat intake from 88.7 +/- 33.9 g/d (33.4% of energy) to 38.8 +/- 19.9 g/d (31.1% of energy), protein intake from 89.5 +/- 36.5 g/d (14.8% of energy) to 50.7 +/- 16.9 g/d (19.0% of energy), carbohydrates intake from 312.7 +/- 106.6 g/d (51.8% of energy) to 134.5 +/- 53.7 g/d (50% of energy). In obese women mean intake of energy decreased from 10,376.3 +/- 2953.9 kJ to 4665.2 +/- 1380.7 kJ. The value of total energy, total fat and saturated fatty acids intake correlated with body weight, BMI and body fat. After dietary treatment the body weight decreased by 2.4 kg (3.3%) in overweight women and by 3.9 kg (4.1%) in obese women and percent of body fat decreased by 1.6% and 2.3%, respectively. Body fat mass determined by BIA method significantly correlated with skinfolds method by Siri, Schutte, Rathbun, Brozek, Keys-Brozek, and BMI method by Webster, Deurenberg. CONCLUSION: BIA method may be a helpful tool for the analysis of changes in total body composition occurring under obesity treatment.

Adipose Tissue↗
PubMed2001

[Measurements of cerebral blood flow by the noninvasive microsphere method with 123I-IMP and fan beam collimator: comparison with the continuous arterial blood sampling method].

PURPOSE AND METHODS: The noninvasive microsphere (NIMS) method quantifies cerebral blood flow with N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) without blood sampling of a patient, but when a fan beam collimator is used for collecting raw data in single photon emission computed tomography (SPECT), the procedure is complicated because we have to change the collimator. In phantom and clinical studies we investigated the validity of using a fan beam collimator in collecting planar and SPECT raw data. RESULTS: The phantom study suggested that using a fan beam collimator for planar imaging was feasible because of the image magnification rate and the count rate. Mean cerebral blood flow (mCBF) values obtained by the NIMS method with the fan beam collimator were compared with mCBF simultaneously estimated from the conventional continuous arterial blood sampling (microsphere: MS) method in twenty patients with ischemic cerebral vascular diseases. There was good correlation (y = 1.033x + 8.004, r2 = 0.729, p < 0.01) in mCBF between the fan beam NIMS method and the MS method. CONCLUSION: In conclusion, this method for the measurement of CBF was acceptable for routine clinical studies.

Brain Ischemia↗
PubMedDate not supplied

[Comparative evaluation of 2 methods for the determination of pyruvate dehydrogenase activity in tissues in avitaminosis B 1 induced by various methods].

A method for determination of pyruvate dehydrogenase activity in mitochondria and tissue homogenates was developed. The method was based on a spectrophotometric monitoring of p-nitroaniline acetylation under conditions required to ensure correct stoichiometric course of the reaction. In rat tissues absolute amounts of the enzyme activity, determined by the method, were found to be several-fold lower as compared with the values determined by the conventional ferricyanide method. Within 24 hrs after a single administration of hydroxythiamin into rats (400 mg per 1 kg of body weight) the pyruvate dehydrogenase activity was decreased 1.5-fold in heart (as estimated by the reaction of p-nitroaniline acetylation) and did not alter in liver tissue. While if the determinations were carried out by the method of terricyanide reduction the enzyme activity was decreas 7- and 2-fold, respectively, in heart and liver tissue. The data obtained suggest that hydroxythiamin impaired reactions of electron transport in tissues; on the other hand, the data obtained showed that the method for determination of the pyruvate dehydrogenase activity, based on the acetylation reaction, was more specific than the conventional method which involved measuring of ferricyanide reduction.

Animals↗