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At least 595 records · Page 33Linked to original sources
PubMed1977

Paracetamol estimation: comparison of a quick colorimetric method with a standard spectrophotometric method.

A new colorimetric method for the estimation of plasma paracetamol was slightly modified and compared with a standard spectrophotometric method. Good correlation and no significant difference was found between results by the two procedures. Precision, accuracy, and recovery by the colorimetric method were acceptable. On the other hand it is less susceptible than the spectrophotometric method to interference by certain other drugs. The speed and simplicity of the colorimetric method, together with its satisfactory performance, make it a worthwile alternative to the spectrophotometric procedure.

Acetaminophen↗
PubMed1989

Development of the convenient and direct numerical analytical method of the pharmacokinetics of phenytoin by an ordinary and/or the Bayesian weighted least-squares method using the program MULTI2(BAYES).

A Simple and convenient numerical integration method was developed for the purpose of analyzing the pharmacokinetics of phenytoin not only at steady state but also at non-steady state. The algorithm was linked on a nonlinear least-squares method program MULTI2(BAYES). The computing time was significantly decreased compared to Runge-Kutta-Gill Method at analysis by the Simplex algorithm and calculating precision was higher, especially at a large integration interval. This method was found to be sufficiently applicable to the analyses of the serum concentrations of phenytoin at non-steady state as well as at steady state and the dosage adjustment by simulation. The flexibility of analyzed parameters on a microcomputer can be overcome by analyzing at the integration subinterval smaller than 0.25 h with the appropriate initial values of parameters, although very time consuming, or by using the Bayesian method with appropriate population parameters.

Bayes Theorem↗
PubMed2002

Comparing the Fourier modal method with the C method: analysis of conducting multilevel gratings in TM polarization.

The coordinate transformation method (C method) with adaptive spatial resolution and the Fourier modal method (FMM) are compared in the case of conducting discontinuous multilevel gratings in TM polarization. A procedure permitting analysis of such gratings more efficiently with the C method than with the FMM is presented. The C method is observed to converge more rapidly than the FMM, whose instabilities are shown to harm the convergence in the aforementioned case.

Journal Article↗
PubMed2006

Fast numerical method for electromagnetic scattering by rough layered interfaces: propagation-inside-layer expansion method.

Electromagnetic scattering from a stack of two one-dimensional rough surfaces separating homogeneous media is modeled with a rigorous integral formulation solved by the method of moments. We present an efficient numerical method for computing the field scattered by such rough layers, in reflection as well as in transmission. We call this method propagation-inside-layer expansion (PILE) due to its straightforward physical interpretation. To our knowledge, it is the first method able to handle problems for this configuration with a huge number of unknowns. We study the convergence of this method versus a coupling condition and validate it by comparison with results from the literature.

Journal Article↗
PubMed1989

A comparison of reference method values for calcium, lithium and magnesium with method-dependent assigned values.

Commercially available control sera were analysed by the reference methods for calcium, lithium and magnesium. Calcium: The mean deviation of the target values for routine flame atomic absorption spectrometry from the reference method values was -1.2%, in the case of flame atomic emission spectrometry -0.1%. The assigned values of determinations by methylthymol blue and cresolphthalein showed a positive bias: +2.3 and +2.2%. Lithium: Target values for routine flame atomic absorption spectrometry and flame atomic emission spectrometry were in generally good agreement with the reference method values (deviation +1.7% and +0.7%), although the differences were dependent on concentration. Magnesium: The assigned values for routine flame atomic absorption spectrometry yielded a mean bias of -0.4% from the reference method value. The target values for absorption spectrometry after reaction with Magon and Calmagite, however, differed by +8.2% and +9.3% on average. These methods seem to be less suitable for the determination of magnesium in serum than FAAS and would have failed several times to meet the requirements of quality assessment.

Calcium↗
PubMed2004

[Principle of LAMP method--a simple and rapid gene amplification method].

So far nucleic acid test (NAT) has been employed in various fields, including infectious disease diagnoses. However, due to its complicated procedures and relatively high cost, it has not been widely utilized in many actual diagnostic applications. We have therefore developed a simple and rapid gene amplification technology, Loop-mediated Isothermal Amplification (LAMP) method, which has shown prominent results of surpassing the performance of the conventional gene amplification methods. LAMP method acquires three main features: (1) all reaction can be carried out under isothermal conditions; (2) the amplification efficiency is extremely high and tremendous amount of amplification products can be obtained; and (3) the reaction is highly specific. Furthermore, developed from the standard LAMP method, a rapid LAMP method, by adding in the loop primers, can reduce the amplification time from the previous 1 hour to less than 30 minutes. Enormous amount of white precipitate of magnesium pyrophosphate is produced as a by-product of the amplification, therefore, direct visual detection is possible without using any reaction indicators and detection equipments. We believe LAMP technology, with the integration of these features, can rightly apply to clinical genetic testing, food and environmental analysis, as well as NAT in different fields.

Chemical Precipitation↗
PubMed1979

A comparison between the transthoracic electrical impedance method and the direct Fick and the dye dilution methods for cardiac output measurements in man.

In fourteen patients referred for preoperative evaluation of heart disease we compared the transthoracic electrical impedance method to the direct Fick (four patients) and dye dilution methods (ten patients) for estimation of cardiac output. On statistical analysis of paired differences we found no reliable agreement between the absolute impedance values and the reference methods. The reproducibility was, however, acceptable, and the coefficient of variation for impedance cardiac output was 7.8%, and for impedance stroke volume 7.6%. Our conclusion is that in patients with advanced heart disease cardiac output cannot be determined with accuracy with the impedance cardiographic method. In clinical practice this must be considered so important, that we hesitate to use the method for monitoring cardiac output in critically ill patients even if the reproducibility for individual changes is acceptable.

Adult↗
PubMed1989

[A study of the risk factors in calcium oxalate stone formation--simple method for measuring metastable limits by the microplate method].

The stone forming urinary environment may be conducive to spontaneous nucleation of calcium oxalate, since it is generally characterized by a reduced metastable limit. This study indicates that the microplate method offers simple and reliable measures for estimating calcium oxalate's propensity for spontaneous nucleation. In measuring the metastable limit by the microplate method, 200 microliters aliquots of each urine sample were treated with sodium oxalate to give final concentrations of 0-1.5 mmol. The urine samples were then incubated at 37 degrees C for 20 min and the minimum amount of oxalate necessary to induce nucleation detectable by inverted microscopy was taken to be the measured metastable limit of each urine. The metastable limit by microplate method positively was correlated (p less than 0.001) with the metastable limit found by the Coulter counter method and inversely correlated (p less than 0.001) with the concentration product ratio. The metastable limits were significantly lower (p less than 0.001) in recurrent stone formers than in the control subjects. The metastable limit rose significantly (p less than 0.01) during treatment with thiazides. Moreover, the metastable limit was inversely correlated (p less than 0.01) with the stone episode rate. It is concluded that the metastable limits by the microplate method are useful in stone forming potential identification in urine as well as in the assessment of the response to the therapy.

Adult↗
PubMed1999

The Misgav Ladach method for cesarean section: method description.

SUBJECT: A method description is given for the Misgav Ladach method for cesarean section. This is based on the Joel-Cohen incision originally introduced for hysterectomy. METHOD: The incision is a straight transverse incision somewhat higher than the Pfannenstiel incision. The subcutaneous tissue is left undisturbed apart from the midline. The rectus sheath is separated along its fibres. The rectus muscles are separated by pulling. The peritoneum is opened by stretching with index fingers. The uterus is opened with an index finger and the hole enlarged between the index finger of one hand and the thumb on the other. The uterus is closed with a one-layer continuous locking stitch. The visceral and parietal peritoneal layers are left open. The rectus muscle is not stitched. The rectus sheath is stitched with a continuous non-locking stitch. The skin is closed with two or three mattress sutures. The space in between is apposed with non-traumatic forceps for 5 minutes. RESULTS: The basic philosophy is to work in harmony with the body's anatomy and physiology and not against them. The method is restrictive in the use of sharp instruments, preferring manual manipulation. CONCLUSION: The method gives quicker recovery, less use of post-operative antibiotics, antifebrile medicines and analgesics. There is a shorter anesthetic and shorter working time for the operative team. It is suitable for both emergency and planned operations.

Cesarean Section↗
PubMed1999

Rapid method for diagnosis of leprosy by measurements of antibodies to the M. leprae 35-kDa protein: comparison with PGL-I antibodies detected by ELISA and "dipstick" methods.

A new rapid immuno-chromatographic test card for the detection of antibodies to the Mycobacterium leprae 35-kD protein is described. The new assay is compared in the same group of subjects with a direct enzyme ELISA method for 35-kD antibodies and with assays for anti-phenolic glycolipid-I (PGL-I) antibodies using a standard ELISA as well as the recently described "dipstick" method. Good concordance was found between the rapid methods and the corresponding ELISA methods. The detection of untreated paucibacillary leprosy by the 35-kD test card was 59% compared with 27% for the PGL-I dipstick; however, the specificity for the 35-kD test card was 90% compared with 100% for the PGL-I dipstick in an endemic population. The potential application of these new, rapid serologic methods for the diagnosis of leprosy under field conditions is discussed.

Adolescent↗
PubMed1998

[Patch clamp recording in brain slice--modified blind method and the perforated patch clamp method].

The use of the patch clamp recording in combination with the technique of the brain slice is the forefront method widely used in the studies of the neurocircuit in vitro. However, few authors in the papers published in domestic journals adopted this method. This paper presents the author's work to modify some details of blind method and the perforated patch clamp method. We used a dissecting microscope (with 40 times object lens) to replace the reverse microscope. As the recording electrode is very important in the experiment, we studied the size and the shape of the electrode tip and used two to three steps to pull the electrode so that the process of polishing of the electrode tip was not necessary and in perforated patch recording the synaptic transmission could be observed at the depolarization of 0-40 mV. The author also showed typical current or voltage waveforms in voltage or current mode respectively for guiding how to obtain the tight-seal whole cell patch. As these modifications have facilitated the acquisition of stable recording and lowered the cost of instrumentation, the methods become more suitable for the use in domestic laboratories.

Animals↗
PubMed2000

Are convective methods superior to diffusive dialytic methods?

The principle of convective elimination is the passage of solutes through the membrane carried by water flux, so the elimination of all substances for which membrane is permeable is equal to water. This results in uniform clearances of small, medium and large molecules. Dialytic methods with exclusive or considerable convective elimination are hemofiltration, hemodiafiltration and high-flux hemodialysis. Only by convective methods, middle (MM 300-15,000 D) and large molecules (MM > 1-15,000 D) are cleared. Standard low-flux hemodialysis does not eliminate a considerable amount of medium and large molecules, in contrast to outstanding efficiency in small molecule removal. Clinical significance of larger molecule removal was analyzed in 4 studies prominent for a great number of patients included, very long observation times, or prospective, multicentric randomized design. In 3 studies, dialytic methods with convective elimination were connected with a mortality decrease by 10% to 39% (statistically significant in 2 studies). Dialysis amyloidosis morbidity was lowered by 42%-50% when convective methods were used. Results of the presented studies support the conclusion that dialytic methods with convective elimination are beneficial for survival and prevention of dialysis amyloidosis, irrespective of the biochemical characteristics and complement activation by the membrane used.

Diffusion↗
PubMed2000

[Effect of heparin cofactor II on the antithrombin III activities measured by thrombin methods or factor Xa methods--fundamental studies and clinical studies using the plasma of pregnant women].

We evaluated the effects of heparin cofactor II(HC II) on the antithrombin III(AT III) activities measured by the methods of thrombin or factor Xa. Reagents A and B were using the method of thrombin and reagent C was based on the method of Xa. Purified HC II was directly measured or indirectly measured after the dilution with control plasma. Cross reaction of HC II in AT III assay were negligible in reagent C, but substantial amount of AT III activities were measured in reagent A and B. Plasma AT III activities from full-term pregnant women were significantly higher than those from non pregnant control women in reagent A, but comparable in reagent B or C. These results indicate that AT III activities measured by thrombin methods by thrombin were overestimated in pregnant women due to the cross-reactivities of HC II. It is recommended that AT III activities would be measured by the methods of factor Xa.

Antithrombin III↗
PubMed2001

[The case method--a new student-activating method in medical education].

The case method is a student-activating method, used together with problem based learning (PBL) and traditional teaching methods in the curriculum for undergraduate medical education at the Faculty of Medicine in Lund/Malmö, Sweden. The case method provides training in the solving of clinical problems and is thus especially useful at the clinical level of medical education, and in an integrated and problem based curriculum. The case method consumes less teaching resources than PBL, and might thus be useful in a situation with increasing numbers of medical students.

Curriculum↗
PubMed2001

[Studies on kinetic viscoelasticity of slow muscle fibers--2. Dynamic stiffness changes studied by quick release method and frequency response method].

PURPOSE: To evaluate the mechanical properties of slow fibers and fast fibers which make up the extraocular muscles in rabbits. SUBJECTS AND METHOD: I studied the contractile properties and viscoelastic properties of the superior rectus muscle(SR) and the retractor bulbi muscle (RB) of rabbits using the quick release method and the frequency response method. RESULTS: In the quick release method, isometric tension transients were slower in the SR than in the RB. In the frequency response method, the muscle length is perturbed sinusoidally to measure kinetic viscoelasticity. In resting muscle, dynamic stiffness was not changed with increasing frequency. In contracted muscle, dynamic stiffness was increased with increasing frequency, and the rate of increase was greater in the SR than in the RB. CONCLUSION: It was concluded that the viscoelasticity of the activated cross bridge is greater in slow fibers than in fast fibers.

Animals↗
PubMedDate not supplied

Method extension study to validate applicability of AOAC Official Method 996.14 Assurance polyclonal enzyme immunoassay for detection of Listeria monocytogenes and related Listeria spp. from environmental surfaces: collaborative study.

Test portions from 3 environmental surface types, representative of typical surfaces found in a food production facility, were analyzed by the Assurance Listeria Polyclonal Enzyme Immunoassay (EIA) and the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) culture method for Listeria monocytogenes and related Listeria species. In all cases, naturally contaminated environmental test samples were collected from an actual food production facility by sponge or swab. Test samples from concrete surfaces were collected by both swab and sponge; sponge test samples were collected from rubber surfaces, and swabs were used to sample steel surfaces. Test portions from each surface type were simultaneously analyzed by both methods. A total of 23 collaborators, representing government agencies, as well as private industry in both the United States and Canada, participated in the study. During this study, a total of 550 test portions and controls was analyzed and confirmed, of which 207 were positive and 336 were negative by both methods. Six test portions were positive by culture, but negative by the EIA. Three test portions were negative by culture, but positive by the EIA. Two test portions were negative by EIA and by culture, but confirmed positive when EIA enrichment broths were subcultured to selective agars. The data reported here indicate that the Assurance Listeria EIA method and the USDA/FSIS culture method are statistically equivalent for detection of L. monocytogenes and related Listeria species from environmental surfaces taken by sponges or swabs.

Bacteriological Techniques↗
PubMedDate not supplied

Method extension study to validate applicability of AOAC Official Method 997.03 visual immunoprecipitate assay (VIP) for Listeria monocytogenes and related Listeria spp. from environmental surfaces: collaborative study.

Test portions from 3 environmental surface types, representative of typical surfaces found in a food production facility, were analyzed by the Visual Immunoprecipitate assay (VIP) and the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) culture method for Listeria monocytogenes and related Listeria species. In all cases, naturally contaminated environmental test samples were collected from an actual food production facility by sponge or swab. Test samples from concrete surfaces were collected by both swab and sponge; sponge test samples were collected from rubber surfaces, and swabs were used to sample steel surfaces. Test portions from each surface type were simultaneously analyzed by both methods. A total of 27 laboratories, representing government agencies as well as private industry in both the United States and Canada, participated in the study. During this study, a total of 615 test portions and controls was analyzed and confirmed, of which 227 were positive and 378 were negative by both methods. Nine test portions were positive by culture, but negative by the VIP. Five test portions were negative by culture, but positive by the VIP. Four test portions were negative by VIP and by culture, but confirmed positive when VIP enrichment broths were subcultured to selective agars. The data reported here indicate that the VIP method and the USDA/FSIS culture method are statistically equivalent for detection of L. monocytogenes and related Listeria species from environmental surfaces taken by sponges or swabs.

Bacteriological Techniques↗
PubMed1976

Evaluation of a reagent-strip method for glucose in whole blood, as compared with a hexokinase method.

The hexokinase method (I) for glucose in biological fluids, proposed by the FDA as a potential national standard method, is compared with the Eyetone/Dextrostix/Control method (II) for measurement of glucose in whole blood. I used a new, two-step calibration procedure based on a 1.30 g/liter standard for the II system. The correlation coefficient for results by the two methods was 0.99 for 142 assays in duplicate. Recovery values were near 100% (I, range 100.0 to 106.2%; II, range 100.8 to 105.1%), and the coefficients of variation were respectively +/- 4.1% and +/- 4.5%. Considering the close correlation between the two methods, together with the simplicity, speed, and convenience of II, I conclude that it has great clinical utility, particularly in emergency situations. The precision and accuracy of II depends greatly on proper calibration and control procedures and on adequate training of the operator.

Bilirubin↗