Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “new 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 109 records · Page 6Linked to original sources
PubMed1973

The optical density of erythrolabe determined by a new method.

1. A new method is described for the determination of optical density by retinal densitometry based on an analysis of stray light.2. The basic assumption used is that the stray light present in retinal densitometry is independent of wave-length. The justification for this assumption is considered.3. The stray light and hence the optical density was determined by a method of successive approximations using a Linc 8 computer.4. The optical density of erythrolabe for the direction of maximum Stiles-Crawford efficiency was determined for five subjects, two deuteranopes, two deuteranomalous and one red-rich normal subject. The mean values for three of the subjects were close to the grand mean value of 0.42, but the other two subjects had considerably higher and lower values respectively.5. The results are in satisfactory agreement with optical density values determined by the self-screening method using retinal densitometry, and also with determinations using microspectrophotometry and psychophysics.6. The relevance of dielectric wave-guide modes in the outer segments is considered.

Color Vision Defects↗
PubMed1995

Daily excretion levels of an unidentified ketosteroid in the urine of patients with Cushing's syndrome and healthy subjects measured by a new method.

We developed a new method for measuring an unidentified ketosteroid glucuronide (US-G) detected by the method of Iwata et al. for measuring 17-ketosteroid glucuronides by reversed phase HPLC on a Capcell-Pak C8 column with three kinds of mobile phase solutions (Iwata method; Clin Chem 35: 795-799, 1989). The Iwata method inadequately separated US-G and two hydroxy 17-ketosteroides, 11 beta-hydroxyetiocholanolone and 11 beta-hydroxyandrosterone, and it exhibits insufficient sensitivity for measuring traces of US-G in the urine of healthy subjects. We solved these problems by developing a new method which measures US-G in urine, as a free type by hydrolyzing the glucuronide type enzymatically, by normal phase HPLC on a Capcell-Pak Silica column with one kind of mobile phase solution. By this method, the levels of US excreted as a glucuronide in the urine of healthy subjects and of patients with Cushing's syndrome were determined as proportions of the levels of 11 beta-hydroxyandrosterone. The average daily urinary excretion of US was 971 micrograms (125-4,995 micrograms) in patients with Cushing's syndrome (n = 22: two males and 20 females aged 26 to 65 years), and 34 micrograms (0-141 micrograms) in healthy subjects (n = 63: 49 males, and 14 females aged 21 to 54 years), and the differences were clearly significant. However, there were no differences between the urinary US levels of patients with pituitary adenoma and patients with adrenal adenoma. Furthermore, no US was detected in the urine of patients with aldosteronism (two males and eight females aged 34 to 61 years).(ABSTRACT TRUNCATED AT 250 WORDS)

17-Ketosteroids↗
PubMedDate not supplied

Conservative surgery for tubal pregnancy: a new method.

A new technique of conservative surgery for tubal pregnancy is presented. The procedure is simple and easily applied whenever the pregnant fallopian tube is not ruptured and there is a desire for further pregnancy. Although the number of cases is very small, the results are promising.

Fallopian Tubes↗
PubMed1995

New methods for estimating the numbers of synonymous and nonsynonymous substitutions.

New methods for estimating the numbers of synonymous and nonsynonymous substitutions per site were developed. The methods are unweighted pathway methods based on Kimura's two-parameter model. Computer simulations were conducted to evaluate the accuracies of the new methods, Nei and Gojobori's (NG) method, Miyata and Yasunaga's (MY) method, Li, Wu, and Luo's (LWL) method, and Pamilo, Bianchi, and Li's (PBL) method. The following results were obtained: (1) The NG, MY, and LWL methods give overestimates of the number of synonymous substitutions and underestimates of the number of nonsynonymous substitutions. The major cause for the biased estimation is that these three methods underestimate the number of synonymous sites and overestimate the number of nonsynonymous sites. (2) The PBL method gives better estimates of the numbers of synonymous and nonsynonymous substitutions than those obtained by the NG, MY, and LWL methods. (3) The new methods also give better estimates of the numbers of synonymous and nonsynonymous substitutions than those obtained by the NG, MY, and LWL methods. In addition, estimates of the numbers of synonymous and nonsynonymous sites obtained by the new methods are reasonably accurate. (4) In some cases, the new methods and the PBL method give biased estimates of substitution numbers. However, from the number of nucleotide substitutions at the third position of codons, we can examine whether estimates obtained by the new methods are good or not, whereas we cannot make an examination of estimates obtained by the PBL method. (5) When there are strong transition/transversion and nucleotide-frequency biases like mitochondrial genes, all of the above methods give biased estimates of substitution numbers. In such cases, Kondo et al.'s method is recommended to be used for estimating the number of synonymous substitutions, although their method cannot estimate the number of nonsynonymous substitutions and is time-consuming. These results, particularly result (1), call for reexaminations of some genes. This is because evolutionary pictures of genes have often been discussed on the basis of results obtained by the NG, MY, and LWL methods, which are favorable for the neutral theory of molecular evolution.

Animals↗
PubMedDate not supplied

Otoscopy and photography: a new method.

A new hand-held otoscope photographic system, convenient and suitable for clinical application, is introduced. This instrument allows clear otoscopic examination in stenotic or tortuous ear canals, and photographs the subject in one procedure. The instrument consists of a rod-lens optical system, a fiberoptic light source, a camera, and exchangeable speculum and a strobe light. Color photographs of tympanic membranes and middle ear pathology are presented.

Ear Canal↗
PubMed1992

[Percutaneous transjugular intrahepatic portosystemic shunt (TIPS). The preliminary experience and proposal of a new method].

A new interventional procedure employing metallic stents has been recently suggested to perform percutaneous portosystemic shunts in the treatment of variceal bleeding in portal hypertension; the technique is called TIPSS (transjugular intrahepatic portosystemic stent shunt). This percutaneous treatment presents several advantages over surgery: the shunt diameter can be calibrated according to the degree of portal hypertension; moreover, TIPSS can be performed in patients waiting for liver transplantation because it does not alter the vascular anatomy of liver. The original technique employed transhepatic portography. In this paper the authors report on their personal experience and present their series of 4 patients with portal hypertension and variceal bleeding, in whom TIPSS was performed utilizing noninvasive US guidance. Variceal bleeding was successfully treated in all patients and variceal distension was also obtained.

Adult↗
PubMed1993

[Breast biopsy with fine needle. Evaluation of a new method].

A new methodology to obtain tissue samples from breast tumors through fine needle aspiration is described. This consists of a screwdriver like movement of the needle and continuous aspiration. The tissue is embedded in a blood clot, fixed in 10% formalin and routinely processed for histopathological study. From March 1987 to March 1990 this technique was applied in 84 patients. Ten did not have conventional histopathological study. The 74 patients studied had 76 tumors. Six cases (7.9%) had "unsatisfactory" specimens and nine (11.8%) only allowed cytological diagnosis. The 61 remaining samples (80.3%) were considered "sufficient" for histopathological study. The new methodology had a sensitivity of 95.5% specificity of 100% and positive predictive value of 100%. In this series there were no false positive cases.

Adult↗
PubMed1980

[Evaluation of the antistreptolysin antibody titer with a new method, correlated with other antistreptococcal antibodies].

The Authors have compared two methods (the new Aso Quantum method and the Rantz-Randall traditional method) for the assay of ASO antibodies testing about 2,000 blood samples in out laboratory. Particularly, the data of one hundred of these cases were correlated also to the values of the Streptozyme test, and other parameters of the rheumatology diagnostics. The Authors, considering the final data, think this new method can be applied successfully in the routine of a laboratory.

Antibodies, Bacterial↗
PubMed1975

Mixed-image planimetry. Assessment of a new method for stereometric analysis in microscopy.

A new method for stereometric measurement of surface area in microscopy is described, based on the mixed-image principle. The measurement was accomplished by observing the area on which was superimposed the image of a miniature electric lamp attached to an ordinary planimeter. Mixed-image planimetric measurements were more easily made and required much less time than area calculation by an integrating eyepiece, by weight or by ordinary planimetric measurements of photomicrographs or tracings of the area. Mixed-image planimetric measurements of a finite area varied less than 1 per cent. Such precision was not obtained with the other methods. The new method was devised in vivo stereometric measurements of bone tissue remodelling in rabbit ear chambers, but should find a much wider application in quantitative microscopy of both finite and extensive objects.

Animals↗
PubMed1995

A new method of inference of ancestral nucleotide and amino acid sequences.

A statistical method was developed for reconstructing the nucleotide or amino acid sequences of extinct ancestors, given the phylogeny and sequences of the extant species. A model of nucleotide or amino acid substitution was employed to analyze data of the present-day sequences, and maximum likelihood estimates of parameters such as branch lengths were used to compare the posterior probabilities of assignments of character states (nucleotides or amino acids) to interior nodes of the tree; the assignment having the highest probability was the best reconstruction at the site. The lysozyme c sequences of six mammals were analyzed by using the likelihood and parsimony methods. The new likelihood-based method was found to be superior to the parsimony method. The probability that the amino acids for all interior nodes at a site reconstructed by the new method are correct was calculated to be 0.91, 0.86, and 0.73 for all, variable, and parsimony-informative sites, respectively, whereas the corresponding probabilities for the parsimony method were 0.84, 0.76, and 0.51, respectively. The probability that an amino acid in an ancestral sequence is correctly reconstructed by the likelihood analysis ranged from 91.3 to 98.7% for the four ancestral sequences.

Amino Acid Sequence↗
PubMed2003

A new method of spatial compounding imaging.

A new method of spatial compound imaging is presented that improves image quality without the usual requirement to decrease the frame rate. The new method of imaging utilizes three transducers for data acquisition. The transducer located at the center of the transducer system is a phased array probe that acts as both transmitter and receiver. The other transducers are unfocused pistons that act only as receivers. Envelope data acquired by each transducer are combined to form a final image with improved quality (speckle contrast, target detectability and lateral resolution). It is shown that the improvement in speckle contrast depends on the correlation between individual images acquired by the transducers. The effective aperture approach is used for analytic estimation of the correlation between images in order to optimize the lateral separation between transducers. Using simulations, several compounding strategies have been performed to find the strategy that maximizes image quality. The central frequency of 2.5 MHz is used in simulations. Quantitative analysis of simulated B-mode images shows that the new method of imaging efficiently improves visibility, detectability, and lateral resolution of low contrast regions. The image frame rate is preserved because multiple scans are not required for the spatial compounding.

Computer Simulation↗
PubMed1999

A new method to measure vertebral rotation from CT scans.

CT measurement methods have good reliability for idiopathic scoliosis transverse plane deformity evaluation. However, because of application difficulties and variations in how these methods are applied, more sensitive methods are needed. This paper presents a new method for measurement of vertebral rotation from tomographic scans. First, the method was subject to clinical, intra-observer and inter-observer analysis. Twenty-three patients with adolescent idiopathic scoliosis were studied to test the clinical reliability of this method. There were no statistical differences between the results of the new method and Ho's method (P = 0.3380) in the clinical study. Intraobserver and inter-observer analysis showed that this method was reliable. An experimental study was then conducted to show the confidence limits of our new method, which were found to be +/-1.6 degrees, and there was no significant difference between the mean rotation value obtained from CT scans using our new method and that obtained using the mechanical method. These results suggest that our new method is a simple, practical and reliable method for measurement of vertebral rotation from CT scans.

Adolescent↗
PubMed1977

A new method for the assessment of thyroxine metabolism in the rat.

A new method for assessing thyroxine (T4) metabolism in the rat has been devised and the results that it yields have been compared to those obtained by other methods for assessing peripheral T4 metabolism. The new method uses a simple analysis of the kinetics of exogenous T4 metabolism in rats chronically treated with daily injections of exogenous labeled T4 to determine T4 clearance rates via both fecal and deiodinative pathways. Fecal clearance rates of endogenously labeled hormone measured in rats brought into approximate 125I/127I specific activity equilibrium by administration of iodide of know specific activity in the drinking water were nearly the same as those determined with this new method. Furthermore, total T4 clearance rate determined with the new method agreed well with that measured by the standard single injected technique utilizing radioactive T4. These results indicate that quantitation of the clearance rate of endogenous T4 via not only the fecal, but also the deiodinative, pathway for T4 disposal can be achieved with this new method. In rats made hyperthyroid with exogenous T4, clearance rates of T4 via both deiodinative and fecal pathways were markedly increased. This result supports the concept that hyperthyroidism increases the activity of the tissue mechanisms for metabolizing T4.

Animals↗
PubMed2002

A new method for attenuation coefficient measurement in the liver: comparison with the spectral shift central frequency method.

OBJECTIVE: To assess the feasibility of a new method of measuring the attenuation coefficient in the liver, which offers less variability of results than the conventional method. METHODS: The attenuation coefficient was evaluated on the basis of the following equation with sound field correction: [log(M0 (z)) - tau(z)]. In our system, the attenuation coefficient was also evaluated by the spectral shift central frequency method at the same time. We used 44 cases of normal liver, 40 cases of fatty liver, and 20 cases of cirrhotic liver in the system. RESULTS: With this new method, attenuation coefficient values were 0.59+/-0.10 dB x cm(-1) x MHz(-1) in normal livers, 0.80+/-0.12 dB x cm(-1) x MHz(-1) in fatty livers, and 0.62+/-0.09 dB x cm(-1) x MHz(-1) in cirrhotic livers. In both methods we recorded a statistically significant difference between normal and fatty livers and between fatty and cirrhotic livers (P < .0001). Only in the fatty liver was any significant difference (P < .0001) found between attenuation coefficients in the new method and those in the spectral shift central frequency method (0.70+/-0.05 dB x cm(-1) x MHz(-1)). CONCLUSIONS: This new method, which was more sensitive in detecting fatty infiltration than the spectral shift central frequency method, was considered usable for evaluating the attenuation coefficient of the liver in vivo.

Adolescent↗
PubMed1998

[Study on a new method for spectrophotometry].

In this paper, the relation between absorbance difference and concentration was measured by the ultraviolet spectrophotometer and computer made P-E company of U.S.A. The basic goal is to prove that the standard absorption curve method can be replaced by the new method, in which the sample was put in standard room and the standard material in sample room. Utilizing this method can minimize the error, most importantly, can measure the higher concentration sample, which can not be measured by the standard curve method. The new method does not require a Linear deltaA-c linear relationship.

English Abstract↗
PubMedDate not supplied

[A new method correcting metabolic acidosis].

A new method is suggested for correction of metabolic acidosis. The method consists in a decrease of pH of the bicarbonate sodium solution used for intravenous injection down to the physiological value of pH in the blood at the expense of buffering the solution by CO2. Experimental data conforming the efficiency of the new method application are presented.

Acidosis↗
PubMed2000

Chimeric swine vesicular disease viruses produced by fusion PCR: a new method for epitope mapping.

A new method of epitope mapping based on chimeric swine vesicular disease (SVD) viruses produced by fusion PCR (polymerase chain reaction). Seven out of 16 neutralising and non-neutralising newly produced monoclonal antibodies (MAbs) discriminated between SVD isolate ITL/1/66 and NET/1/92. Using fusion PCR eight chimeric viruses were produced containing different supplementary pieces of the P1 region of both parent strains. Using these chimeric viruses we were able to map the epitope regions recognised by these seven neutralising and non-neutralising Mabs. This new method, using chimeric viruses produced by fusion PCR, is particularly valuable for the epitope mapping of non-neutralising MAbs.

Animals↗
PubMed1996

Probability distribution of molecular evolutionary trees: a new method of phylogenetic inference.

A new method is presented for inferring evolutionary trees using nucleotide sequence data. The birth-death process is used as a model of speciation and extinction to specify the prior distribution of phylogenies and branching times. Nucleotide substitution is modeled by a continuous-time Markov process. Parameters of the branching model and the substitution model are estimated by maximum likelihood. The posterior probabilities of different phylogenies are calculated and the phylogeny with the highest posterior probability is chosen as the best estimate of the evolutionary relationship among species. We refer to this as the maximum posterior probability (MAP) tree. The posterior probability provides a natural measure of the reliability of the estimated phylogeny. Two example data sets are analyzed to infer the phylogenetic relationship of human, chimpanzee, gorilla, and orangutan. The best trees estimated by the new method are the same as those from the maximum likelihood analysis of separate topologies, but the posterior probabilities are quite different from the bootstrap proportions. The results of the method are found to be insensitive to changes in the rate parameter of the branching process.

Animals↗