SEARCH · PubMed Health

Results for “Quantitative Evaluation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMedDate not supplied

Multi-detector CT of the chest: influence of dose onto quantitative evaluation of severe emphysema: a simulation study.

PURPOSE: Quantitative evaluation of the lung parenchyma might be impaired or unreliable by use of reduced-dose CT protocols. Aim of the study was to define the threshold where reduced dose has significant impact on quantitative emphysema parameters. MATERIALS AND METHODS: Thirty patients with severe centrilobular emphysema underwent multidetector computed tomography (120 kV, 150 mAs). Original CT raw data were simulated using 10 mAs settings (10-100 SIMmAs). Quantitative analysis provided lung volume, emphysema volume, emphysema index, mean lung density, and 4 emphysema volume classes. Simulated low-dose results were compared with original acquisition. RESULTS: Emphysema index showed no clinical relevant variation down to 30 SIMmAs. The large emphysema volume class was significantly different below 50 SIMmAs. The intermediate and small classes showed an overproportional variation below 50 SIMmAs. CONCLUSIONS: Dose reduction down to 30 SIMmAs is possible for clinical routine. Settings below 50 SIMmAs significantly alter the in-detailed 3-dimensional emphysema quantification.

Adult↗

PubMed1990

Three-dimensional reconstruction and quantitative evaluation of devascularizing cortical lesions in the rat.

The use of a reconstruction method suitable for three-dimensional (3-D) representations of the cortex for the quantitative evaluation of unilateral devascularizing cortical lesions is reported, demonstrating that 3-D reconstructions can be used for quantitative evaluation of the extent of cortical lesions, in addition to simply visualizing shapes. The procedure allowed the definition of precise quantitative parameters characterizing the volumes and surface areas of the cortical regions involved. It was shown that digitized serial sections from atlases can be utilized for multiple correlation studies by superimposing morphological and biochemical parameters. More specifically, the enzymatic activity of choline acetyltransferase (ChAT) in the nucleus basalis magnocellularis (NBM), and morphological parameters (number and cross-sectional areas) of the ChAT-positive immunoreactive cholinergic neurons, were related to the numerical values for the volume and surface area of the cortical lesions. The applicability of this method goes beyond the scope illustrated in this study. For example, various morphological anomalies in the brain could be quantified; changes in various cortical and subcortical structures could be followed during development; and the 3-D size, shape and position of a graft could be related to the number of viable foetal cells.

Animals↗

PubMed2005

Quantitative evaluation of the fibrin clot extension on different implant surfaces: an in vitro study.

The aim of the present study was a quantitative evaluation of the in vitro fibrin clot extension on different implant surfaces. Forty-five disk-shaped commercially pure Grade 2 titanium samples with three different surface topographies (machined, DPS, and Plus) were used in the present study. For the quantitative evaluation of the fibrin clot, 30 specimens were used (10 per group); human whole blood was employed. Venous blood was drawn from three healthy adult volunteers, and 0.2 mL were immediately dropped onto the surface of each specimen. Contact time was 5 min at room temperature; then the samples were rinsed with saline solution and fixed in a buffered solution of glutaraldehyde and paraformaldehyde. Samples were washed again with buffer and dehydrated in an ascending alcohol series. Specimens belonging to all groups were observed under SEM at a magnification of 1000x. From each sample, 50 random micrographs were collected in .tif format with an N x M 1024 x 768 grid of pixels. Quantitative analysis of fibrin clot extension showed the following results: in machined samples fibrin clot extension was 345987.2 +/- 63747.7 pixels(2) (mean +/- SD), in DPS samples fibrin clot extension was 375930.9 +/- 54726.86 pixels(2) (mean +/- SD), and in Plus samples, fibrin clot extension was 612333.6 +/- 46268.42 pixels(2) (mean +/- SD). With ANOVA it was possible to find that there were significant differences among the groups. The Tukey test revealed that the extension of the fibrin clot of Plus samples was statistically higher compared to both machined and DPS samples. The results of this in vitro study indicate that there is a correlation between implant surface morphology and fibrin clot extension. Improvement in surface microtexture complexity seems to determine the formation of a more extensive and three dimensionally complex fibrin scaffold. Further investigations are necessary to explain in more detail the mechanisms that regulate the fibrin clot formation on different implant surfaces.

Adsorption↗

PubMed1984

Quantitative evaluation of the effects of acetazolamide in Friedreich's ataxia: a pilot study.

We evaluated the effects of acetazolamide in 4 young patients with Friedreich's ataxia by clinical and quantitative laboratory methods. Dynamic muscle function of the lower extremity was measured during isokinetic knee movements and gait. The acetazolamide trial was terminated at 7 to 11 weeks because of reported side effects or increased ataxia in 3 of the patients. The quantitative evaluations revealed lower dynamic strength values and alterations in the gait movement pattern in all patients. These changes, which were interpreted as deterioration, were partially reversible with cessation of acetazolamide. The advantages of such quantitative evaluations of dynamic muscle function in the evaluation of therapy in Friedreich's ataxia are discussed.

Acetazolamide↗

PubMed1991

A quantitative evaluation of sensory dysfunction in lumbosacral radiculopathy.

A quantitative evaluation of sensory disturbance of the foot was attempted in 94 cases of lumbosacral radiculopathy using the biothesiometer, the Semmes-Weinstein esthesiometer, light touch, tuning fork, and dermatomal somatosensory evoked potentials. Dermatomal somatosensory evoked potentials was the most sensitive of these tests, and reflected the duration of the lumbosacral radiculopathy better than the biothesiometer and the Semmes-Weinstein esthesiometer. The biothesiometer and Semmes-Weinstein esthesiometer reflected the clinical severity of sensory dysfunctions, the extent of numbness, and the immediate change in sensory function better than the dermatomal somatosensory evoked potentials. It is important to understand the characteristics of each test and to choose informative tests for clinical use. Grades of sensory disturbance in patients with lumbosacral radiculopathy were classified into three categories in combination with the findings of dermatomal somatosensory evoked potentials and the values recorded with the biothesiometer and Semmes-Weinstein esthesiometer.

Adult↗

PubMed1992

Quantitative evaluation of nuclear cataract using image analysis.

To quantitatively evaluate nuclear lens opacification, we applied image analysis techniques. Utilizing a newly developed anterior eye segment analysis system, Scheimpflug slit images were taken in 65 eyes with transparent lenses and 31 eyes with nuclear cataract. In transparent lenses, scattering light intensity of the anterior fetal nucleus (AFN) was equal to or less than that of the posterior fetal nucleus (PFN). In eyes with nuclear cataract, scattering light intensity of the AFN was higher than that of the PFN. Utilizing this phenomenon, nuclear opacification was evaluated by the difference of scattering light intensity between the AFN and PFN (delta i value). The methodology applied in this investigation provides precise grading of nuclear cataract and progression thereof.

Adult↗

PubMed1992

Evaluating quantitative research problems.

By focusing on criteria for evaluating quantitative research problems and by understanding their evolution from prior research and their placement within a theoretical context, nurses should realize that good research depends to a great degree on good questions. Unless an investigator has a "good, workable, significant topic, the most carefully and skillfully designed research project will be of no value.

Humans↗

PubMed2006

Carbon nanotubes: a promising standard for quantitative evaluation of AFM tip apex geometry.

The direct contact between tip and sample in atomic force microscopy (AFM) leads to demand for a quantitative knowledge of the AFM tip apex geometry in high-resolution AFM imaging and many other types of AFM applications like force measurements and surface roughness measurements. Given, the AFM tip apex may change continuously during measurements due to wear or during storage due to oxidation, it is very desirable to develop an easy and quick way for quantitative evaluation of AFM tip radius when necessary. In this study, we present an efficient method based on Zenhausern model (Scanning 14 (1992) 212) by measuring single-wall carbon nanotubes deposited on a flat substrate to reach this goal. Experimental results show the method can be used for routine quantitative evaluation of AFM tip apex geometry for tips with effective radii down to the nanometer scale.

Journal Article↗

PubMed2005

Quantitative evaluation of acute mucosal reaction to interstitial brachytherapy using color histograms.

PURPOSE: Color histograms of tongue photographs were used to make a quantitative evaluation of acute mucosal reaction to high-dose-rate fractionated interstitial brachytherapy. METHODS AND MATERIALS: Six patients with oral cavity cancer were analyzed with two methods (color histogram and vinyl plate). Using a photograph of the tongue, we calculated the histogram of each pixel of 1mm(2) of the tongue surface. The results were compared with the physician's inspection and the radiation dose. RESULTS: The histogram showed a difference between the reactive area (erythema and pseudomembranous mucositis [PM]) and the nonreactive area. The relationship between inspection and the histogram showed a good correlation, although the histogram tended to change earlier than the subjective judgment. The peak time was 12-13 days after delivery of the final fraction of brachytherapy. The minimum dose required to cause PM was 3.3-3.6Gy per fraction (total: 29.7-32.4Gy). CONCLUSIONS: Our new method of using color histograms for quantitative evaluation is helpful in the analysis of the relationship between mucosal reaction and radiation dose. The minimum dose causing PM was considered to be about 30Gy per nine fractions.

Acute Disease↗

PubMed1990

[Quantitative evaluation by measuring affected area for cytotoxicity of dental materials].

The agar overlay method was modified and employed in this study to quantitatively evaluate the cytotoxicity of dental materials. The area of fibroblasts affected by the release of toxic substances from tested materials was determined with an image analysis system in order to compare the relative cytotoxicity of amalgams and composite resins. The cytotoxicity of amalgams decreased by 50% or more with aging time. Zinc appeared to be the major contributor to the cytotoxicity of amalgams. The cytotoxicity of chemically cured composite resins was also reduced with hardening time. However, even after 24 hours, the cytotoxicity of all chemically cured composite resins was still apparent. The cytotoxicity of light cured composite resins was dramatically reduced after illumination with the light source. The cytotoxicity of both amalgams and composite resins was strongly dependent upon their hardening process, since aging and curing produced a more stable material which was less likely to release toxic substances into the culture medium. The technique developed in the present study for measuring the area of affected cells to quantitatively evaluate the cytotoxicity of dental materials is simple and reproducible.

Composite Resins↗

PubMed1989

Qualitative and quantitative evaluation of chrysotile and crocidolite fibres with infrared spectrophotometry: application to asbestos-cement products.

Infrared (IR) spectrophotometry allows simple and rapid qualitative and quantitative evaluations of different types of asbestos, as well as of other inorganic particles. In particular, chrysotile and crocidolite have characteristic IR spectra, and optical density measurements in the 2710 nm band for chrysotile and the 12820 nm band for crocidolite permit the quantitative evaluation of each fibre either alone or in mixtures. IR spectra also provide information on changes in fibre structure and in chemical composition as the result, for example, of thermal treatment or acid leaching. The analytical method that we have developed can detect amounts as small as 0.1 mg of fibre in a 300-mg disk of potassium bromide using a low-cost IR spectrophotometer. The use of a Fourier transform IR spectrophotometer dramatically improves the sensitivity and selectivity. Computer-assisted analysis of spectra offers the possibility of reducing matrix interference and of comparing different spectra. The application of the IR technique to asbestos-cement products and insulating materials is described.

Asbestos↗

PubMed1993

Quantitative evaluation of mRNAs by in situ hybridization and image analysis: principles and applications.

We describe an image analysis (IA) program that has been developed for the quantitative evaluation of mRNA evidenced by in situ hybridization (ISH) with radiolabeled probes in cultured cells and tissue sections. ISH-IA allowed the detection and quantitative evaluation of mRNA expressed by heterogeneous in vitro cultured cells. This method, when combined with dot-blot analysis, allowed the evaluation of the approximate number of mRNA molecules expressed by single cells. IA permitted the evaluation of cultured cells' morphological parameters (such as cytoplasm and nucleus areas) modifications in relation to specific mRNAs expression, which can vary during cell cycle, development, aging, and in different pathologies and treatment with drugs. ISH-IA was applied for the evaluation of mRNA isoforms generated by alternative splicing in single cells. This methodology was also applied for the semiquantitative evaluation and comparison of mRNA levels expressed by different cell types in human normal and tumor tissue sections.

Alternative Splicing↗

PubMed1986

Qualitative and quantitative evaluation of chrysotile and crocidolite fibers with IR-spectroscopy: application to asbestos-cement products.

Infrared (IR) spectrophotometry allows simple and quick qualitative and quantitative evaluations of different kinds of asbestos, as well as of other inorganic particles. In particular, chrysotile and crocidolite have characteristic IR spectra and optical density measures of 2,710 nm band for chrysotile, of 12,820 nm band for crocidolite permit quantitative evaluation of each fiber alone or in mixture. IR spectra also give informations about changes of fiber structure and of chemical composition due, for example, to thermal treatment or acid leaching. The analytical method we developed can detect levels as low as 0.1 mg of fiber in a 300 mg disk of KBr using a low cost IR spectrophotometer. The use of a Fourier Transform IR spectrophotometer (FTIR) improves dramatically the sensitivity and selectivity. Computer assisted analysis of spectra offers the possibility to reduce matrix interferences and to compare different spectra. Examples of IR technique applied to asbestos-cement products and insulating materials are presented.

Asbestos↗

PubMed2002

Quantitative evaluation of the anal sphincter by the tendency presented in the manometric asymmetry variations.

OBJECTIVES: To assess the tendency of manometric asymmetry, and to quantitatively evaluate the function of the anal sphincter. METHODS: Using the PC polygram HR at the states of relax and squeeze, we compared the values of pressure asymmetry in the anorectum of 27 normal children with that of 12 children with fecal incontinence. RESULTS: In the two states, the anal sphincter in normal children showed not only the gradient of pressure, but also a gradient of pressure asymmetry. Children with fecal incontinence did not show any gradients. CONCLUSION: Gradients of pressure and pressure asymmetry can quantitatively evaluate the function of the anal sphincter.

Adolescent↗

PubMed1997

Further studies of the relationships among strains classified as taxon 15, taxon 18, taxon 20, (Pasteurella) granulomatis or the (Pasteurella) haemolytica-complex in ruminants using quantitative evaluation of phenotypic data.

Ninety-three trehalose-negative (P.) haemolytica-like strains of ruminant, porcine and leprine origin were investigated. A quantitative evaluation of phenotypic tests was used and the results obtained were compared with those from 246 previously investigated ruminant strains. Cluster analysis of the results obtained displayed most of the taxa as distinct groups which could be related to differences in key characters. Although only minor phenotypic differences were observed between the taxa investigated and the taxa were internally heterogeneous for many of the tests, it was possible to identify characters separating most groups. However, in three instances, taxa isolated from different species could not be separated by any of the tests used or by quantitative evaluation of all 79 tests--the only difference being the species of animals from which they had been isolated. Taxa which could not be separated by phenotypic tests included the ruminant biogroup 6 of (P.) haemolytica and the porcine taxon 15/biovar 1, the ruminant biogroup 7 of (P.) haemolytica and the porcine taxon 15/biovar 2, and ruminant biogroup 31 of (P.) haemolytica and the leprine taxon 20/biovar 1.

Animals↗

PubMed1995

Quantitative evaluation of the cutting quality and abrasive resistance of scalers.

An automatic scaling apparatus that simulated the scaling process of hand instrumentation was developed to quantitatively analyze the cutting quality and abrasive resistance of scalers. We first tested 4 synthetic resins as the abraded material. Of the 4 synthetic resins tested, polycarbonate resin proved most similar to dentin. The effects of lateral scaling forces (700, 500, and 300 dyne) and scaler angles (70 degrees to 95 degrees) on the cutting quality and abrasive resistance of scalers were evaluated quantitatively by the amount of the abraded material worn away in 1,000 strokes. Comparison of the 3 scaling forces showed a greater amount of abrasion at higher force than that at lower force. This suggests that the decrease in the amount due to abrasion could be compensated by increasing the lateral scaling force. Regarding the scaler angle, results indicated that the amount of material removed increased with an increase of the scaler angle up to 70 degrees, but then rapidly decreased at an angle of 90 degrees or more. The most effective scaling angle was 87 degrees, and this was not affected by scaling force. These results suggest that a greater amount of removal could be obtained at a scaling angle of 87 degrees and a scaling force of 700 dyne. The present findings suggested the automatic scaling apparatus could be a useful tool for quantitatively evaluating the cutting quality and abrasive resistance of scalers.

Analysis of Variance↗

PubMed2001

Efficacy of computerized discrimination between structure-related and non-structure-related echoes in ultrasonographic images for the quantitative evaluation of the structural integrity of superficial digital flexor tendons in horses.

OBJECTIVE: To evaluate effectiveness of computerized discrimination between structure-related and non-structure-related echoes in ultrasonographic images for quantitative evaluation of tendon structural integrity in horses. SAMPLE POPULATION: 4 superficial digital flexor tendons (2 damaged tendons, 2 normal tendons). PROCEDURE: Transverse ultrasonographic images that precisely matched histologic sections were obtained in fixed steps along the long axis of each tendon. Distribution, intensity, and delineation of structure-related echoes, quantitatively expressed as the correlation ratio and steadiness ratio , were compared with histologic findings in tissue that was normal or had necrosis, early granulation, late granulation, early fibrosis, or inferior repair. RESULTS: In normal tendon, the even distribution of structure-related echoes with high intensity and sharp delineation yielded high correlation ratio and steadiness ratio. In areas of necrosis, collapsed endotendon septa yielded solid but blurred structure-related echoes (high correlation ration and low steadiness ratio). In early granulation tissue, complete lack of organization caused zero values for both ratios. In late granulation tissue, reorganization and swollen endotendon septa yielded poorly delineated structure-related echoes (high correlation ratio, low steadiness ratio). In early fibrosis, rearrangement of bundles resulted in normal correlation ration and slightly low steadiness ratio. In inferior repair, the almost complete lack of structural reorganization resulted in heterogeneous poorly delineated low-intensity echoes (low correlation ratio and steadiness ratio). CONCLUSIONS AND CLINICAL RELEVANCE: The combination of correlation ratio and steadiness ratio accurately reflects histopathologic findings, making computerized correlation of ultrasonographic images an efficient tool for quantitative evaluation of tendon structural integrity.

Animals↗

PubMedDate not supplied

Quantitative evaluation of "sunset glow" fundus in Vogt-Koyanagi-Harada disease.

PURPOSE: To evaluate the color of the fundus quantitatively, especially the "sunset glow" fundus, in patients with Vogt-Koyanagi-Harada (VKH) disease. METHODS: The fundus of 39 patients (13 men and 26 women) who were diagnosed with VKH disease were photographed. The photographs were scanned by a film scanner and the amount of red, green, and blue pixels making up the image was determined by image analyzing software. A "sunset glow" index, the ratio of the number of red pixels to the total number of pixels, was determined for all patients as well as 31 normal controls. RESULTS: In comparison to the controls, the "sunset glow" indices at 3 months after onset of the "sunset glow" fundus showed significant increases in VKH patients. Six months after onset, the "sunset glow" indices showed further significant increases and continued to increase during the course of the disease. CONCLUSIONS: The depigmentary changes can be found earlier by using our method rather than ophthalmoscopy. Because our method is more sensitive for slight depigmentary changes, the pigmentary changes in the fundus could be found in all the VKH patients. This quantitative evaluation of the fundus makes a correct diagnosis possible even in patients who do not demonstrate the "sunset glow" fundus by normal ophthalmoscopic examinations.

Adolescent↗