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Results for “quantitative analysis”

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PubMed1995

[Quantitative analysis of smooth pursuit eye movement].

Abnormalities of smooth pursuit eye movement (SPEM) have been estimated, mainly using the wave form on an electro-oculogram, in a qualitative way. Many methods for quantitative analysis of SPEM have been designed, though most are still uncommon in present clinical use. Using a personal computer, we developed a method of automatic quantitative analysis of ocular tracking eye movement recorded by electro-oculography (EOG). The design concept of this method is based on the observation that eye movement during ocular tracking consists of two different kinds of eye movements, one is SPEM and the other is saccade. The combination of SPEM and saccade (composite eye movement: CEM) commonly appears during ocular tracking. These two kinds of eye movement are essentially different not only in behavior but also about involved neural pathway in the central nervous system. From this point of view, we believe that the two kinds of eye movements involved in ocular tracking should be evaluated separately. The analysis method is outlined as follows. A horizontal sinusoidally moving visual target was employed to elicit ocular tracking eye movements. The test frequencies were set at 0.1, 0.2, 0.4 and 0.8Hz, and the amplitude of target motion was 15 deg at each frequency. The 20 seconds of eye movement data measured by EOG were fed into the computer through a digital-analog converter for further analysis. Using our original saccade detection algorithm, based on the physiological behavior of saccades, the saccadic components were detected and removed from the eye movement wave. The remaining parts, fragments of SPEM, were connected by means of interpolating defective parts. The reconstructed wave was a slow cumulative eye position curve (SCEP). Sinusoidal target motion, CEM and SCEP were processed by the FFT (Fast Fourier Transformation) method. Bode plots were applied to summarize the gain and phase of responses to SCEP and the target motion wave. These processes enable us to estimate abnormalities of SPEM such as low gain, abnormal phase shift and large trends in tested duration. We conclude that the method described here is useful for quantitative estimation of SPEM in clinical neuro-otological examinations.

Adult↗

PubMed2000

Insights into the Electronic Structure of Ceramics through Quantitative Analysis of Valence Electron Energy-loss Spectroscopy.

Valence electron energy-loss (VEEL) spectroscopy was performed on six ceramic materials in a dedicated scanning transmission electron microscope (STEM). Quantitative analysis of these data is described yielding access to the complex optical properties and the electronic structure of the materials. Comparisons are made on the basis of the interband transition strength describing transitions between occupied states in the valence band and empty states in the conduction band. This proves that the quantitative analysis of VEEL data is a competitive and complementary method to be considered when investigating the electronic structure of materials. Possibilities for improvement and extension of the analysis are discussed extensively.

Journal Article↗

PubMed1987

A microcomputer program for the generation of random grid squares in quantitative analysis.

Subjectivity in selecting random grid squares for routine quantitative analysis can be circumvented through a combination of finder grids and a computer program. The simple BASIC program described in this paper generates a list of random grid-square numbers, which are sequentially analyzed. The concept was applied in the quantitation of asbestos and other microparticles in environmental samples. The use of finder grids and this program can also be useful in quality-control programs and in cross-referencing analyses, as well as in the study of biological specimens.

Asbestos↗

PubMed1995

[In situ quantitative analysis of Drosophila histone gene in S-phase].

We used a novel multiparametric microfluorometry analytic system to determine the replication timing of Drosophila histone gene DNA by in situ quantitative analysis of the gene in S-phase under a fluorescent microscope. There are 110 copies of histone genes per genome and each one of them is 5 kb in size. Primary cultured embryo cells were used to make preparations for microscopic analysis. Cells were first stained with DAPI and the total nuclear DNA contents in each nucleus reflected on the fluorescent intensity. We collected data of the fluorescent intensity from 400 of the cells in S-phase (Fig. 4). Then, the very same preparation was subjected to FISH (fluorescent in situ hybridization) using biotinylated DNA probes and FITC, and the fluorescent intensity of the hybridization signals were quantitatively detected from the same 400 cells and in the same order. This data showed the relative quantity of the signals representing the histone genes. From the correlation of fluorescent intensity of DAPI and that of FITC of the cells in S-phase, we found that the histone gene DNA completed its replication during early stage in S-phase (Fig. 5). The method we introduced here is considered to be able to use in many other cases of quantitative analysis directly in cells.

Animals↗

PubMed1992

Prediction of reversible perfusion defects by quantitative analysis of post-exercise electrocardiogram-gated acquisition of technetium-99m 2-methoxyisobutylisonitrile myocardial perfusion scintigraphy.

The aim of this study was to assess the reliability of the quantitative analysis of regional wall thickening with electrocardiographic-gated technetium-99m 2-methoxyisobutylisonitrile (SESTAMIBI) in predicting the reversibility of stress-induced perfusion defects. The assumption was that a preserved resting wall thickening in a segment with stress-induced perfusion defect would predict normal resting perfusion. Twenty-five patients with suspected coronary artery disease underwent planar stress-rest SESTAMIBI scintigraphy. The wall thickening was quantitatively evaluated as percentage increase in counts from diastole to systole; a ratio defined as the wall thickening index (WTI) between patient and normal profile (mean - 2 SD) below 1 was considered abnormal. Improvement of the perfusion pattern at rest was observed in 76% (54/71) of segments with a stress-induced perfusion defect; 90% of these segments had a (WTI) greater than 0.8. Five segments (9%) showed fixed perfusion defects despite a WTI value greater than 0.8. In conclusion, quantitative analysis of regional wall thickening by electrocardiographic-gated SESTAMIBI identifies segments with reversible perfusion defects; this may overcome the need for studies at rest and may direct the detection of hypoperfused but viable myocardium.

Coronary Disease↗

PubMed1989

[Immunoglobulins in periapical lesion with special reference to qualitative and quantitative analysis of IgG].

Immunoglobulins in periapical lesions (including 34 radicular cysts and 11 radicular granulomas) were investigated through extracts of the lesions and cystic fluids. The extracts of dental sacs and sera were used as a control. For a qualitative analysis, the immunoglobulins (especially IgG) of each sample were investigated by agarose gel electrophoresis and agarose gel isoelectric focusing. For quantitative analysis, single radial immunodiffusion was employed for determining the concentration of IgG, IgG subclasses, IgA and IgM in the extracts, cystic fluids and autologous sera, also IgE in cystic fluids. In agarose gel electrophoresis, homogeneous bands that were regarded as monoclonal or oligoclonal patterns in gamma region were identified with IgG by immunofixation. These bands were detected in 65% of the radicular cysts, 73% of the radicular cysts obtained cystic fluid, and 73% of the radicular granulomas, but were not detected in any of the autologous sera and dental sacs. In cases that these homogeneous bands were found in extract of cyst, the same bands were found in fluid of same radicular cyst. These results strongly suggested that a part of IgG in periapical lesions was locally produced. By agarose gel isoelectric focusing, immunoglobulins in the extract, cystic fluid and serum were investigated. Many clearly detectable bands were found in extracts of periapical lesions and cystic fluids in the range of pH 6-9 and identified with IgG by immunofixation. These findings revealed restricted heterogeneity of IgG. These IgG bands were found randomly in the range of pH 6-9 and no specific inclination of arrangement. These results suggested that IgG in periapical lesions seem to have different specificities in immunological reaction. Furthermore, in isoelectric focusing pattern of IgG, similar bands were identified in the extract of the cystic wall and fluid of same radicular cyst in 82% of the cases. These bands were detected in some of the dental sacs but not in the serum. Therefore it means that a quantities of IgG in periapical lesions and cystic fluids were locally produced. By quantitative analysis, no statistically significant differences were found in the concentration of IgG, IgG subclasses, IgA and IgM in sera between periapical lesion group and control group.

Immunoglobulin G↗

PubMed2000

Quantitative analysis of relative protein contents by Western blotting: comparison of three members of the dystrophin-glycoprotein complex in slow and fast rat skeletal muscle.

We have developed a method for accurate quantitative analysis and statistical comparison of the relative contents of the dystrophin-glycoprotein complex (DGC) in skeletal muscle. This method was applied to compare DGC contents in slow (soleus) and in fast (extensor digitorum longus, EDL) rat skeletal muscles. The quantitative analysis combines a modified bicinchoninic acid (BCA) assay with Western blotting and enhanced chemiluminescence (ECL). This combination allows the use of high levels of detergents and reducing reagents essential for extracting DGC. In addition, the evaluation of the total amount of proteins in each sample makes it possible to have a reference and to accurately compare relative protein levels without using a specific standard. With a large gradient gel, we could concomitantly compare two groups (n = 9) and quantify all protein contents differing highly in their molecular masses (from 35 kDa to 427 kDa). Each experiment was triplicated and normalized; the two muscles were compared using the Mann-Whitney test (P<0.001) to establish their protein content. The DGC relative levels for the slow muscle soleus and the fast muscle EDL differed significantly: dystrophin, beta-dystroglycan, and gamma-sarcoglycan levels were 130%, 110% and 120% higher in the soleus, respectively. The differences observed in the expression level of cytoskeletal associated protein (dystrophin) and transmembranous anchorage components may correspond to a physiological response of the muscle fibers to duration, magnitude, and frequency of the imposed mechanical loading.

Animals↗

PubMed1999

Area under pH 4: a more sensitive parameter for the quantitative analysis of esophageal acid exposure in adults.

OBJECTIVE: Traditional quantitative analysis of 24-h esophageal pH monitoring data does not include the pH of reflux episodes. Area under pH 4 (AU4) is a recently introduced parameter that describes the acid exposure rate through both duration and depth of pH falls. METHODS: In Study A, we enrolled 20 healthy controls and 42 patients (18 without esophagitis, 24 with Savary I-III esophagitis) in a study evaluating reference values for 24-h reflux time at pH <4 (RT) and 24-h AU4 by means of receiver operating characteristic (ROC) discriminant analysis. For Study B, we next prospectively applied the resulting cutoffs to 16 healthy controls and to 110 gastroesophageal reflux (GERD) patients (55 with esophagitis) to adjust sensitivity, specificity, and predictive values of both RT and AU4. RESULTS: In Study A, the best cutoff values were 5.1% for RT (Area Index +/- SE, 0.899 +/- 0.038; 95% confidence interval [C.I.], 0.796 +/- 0.961) and 36.1 pH x min for AU4 (Area Index +/- SE, 0.935 +/- 0.03; 95% C.I., 0.842 +/- 0.981); AU4 gave the best performance (p = 0.038 vs RT) in discriminating controls and GERD patients. In Study B, RT was abnormal in three controls and 79 patients; AU4 identified all the controls and patients with abnormal RT and also 10/31 patients (32.3%) with so-called "normal" acid exposure (according to RT). In the whole GERD group of patients, AU4 and RT specificity was 81.2%, whereas sensitivity was 71.8% for RT and 80.9% for AU4 (chi2, 61.831; DF, 1; p < 0.005); PPV/NPV were 96.3%/29.5% for RT, and 96.7%/38.2% for AU4. CONCLUSIONS: AU4 appears to be a simple and sensitive quantitative parameter to measure the esophageal acid exposure in adults submitted to 24-h pH monitoring, and it could be an useful clinical aid in evaluating normal RT tests where, from a clinical point of view, a reflux disease is highly likely.

Adult↗

PubMed1999

Evaluation of a sugar-free medicines campaign in north east England: quantitative analysis of medicines use.

OBJECTIVE: The aim of the study was to evaluate the effectiveness of a sugar-free medicines campaign using suitable prescribing and purchasing indicators. BASIC RESEARCH DESIGN: Quantitative analysis of sugar-free medicine use, before (1995) and after (1996) the campaign. CLINICAL SETTING: Two test and two control districts in north east England. PARTICIPANTS: General medical practitioners (GPs) and community pharmacists. INTERVENTION: A 12-month campaign involving development and distribution of information packs designed to increase the proportion of prescriptions dispensed sugar-free for paediatric use. MAIN OUTCOME MEASURES: Changes in the proportion of the following which were sugar-free: (a) for target prescribed medicines (i) number of prescriptions dispensed. (ii) number of prescribed daily amounts (PDA); (b) for target over the counter (OTC) medicines, (i) number of bottles sold, (ii) number of standard daily amounts (SDA) sold. RESULTS: Quantitative analysis of prescriptions and OTC sales showed statistically highly significant changes towards sugar-free prescribing and dispensing of prescribed medicines but only small increases in the proportion of some sugar-free OTC sales. CONCLUSIONS: The impact of the campaign was shown to be greatest in changing prescribing habits of GPs with less effect on OTC medicine use. The outcome measures used were suitable for quantitative evaluation of the campaign. POST-CAMPAIGN DEVELOPMENT: Sustainable changes in GPs' prescribing behaviour can be facilitated by software suppliers' modifications to computing software used for prescription writing.

Carbohydrates↗

PubMed2001

Quantitative analysis of the effect of salt concentration on enzymatic catalysis.

Like pH, salt concentration can have a dramatic effect on enzymatic catalysis. Here, a general equation is derived for the quantitative analysis of salt-rate profiles: k(cat)/K(M) = (k(cat)/K(M))(MAX)/[1+([Na+]/K[Na+])(n')], where (k(cat)/K(M))(MAX) is the physical limit of k(cat)/K(M), K(Na+) is the salt concentration at which k(cat)/K(M) = (k(cat)/K(M))(MAX)/2, and -n' is the slope of the linear region in a plot of log(k(cat)/K(M)) versus log [Na+]. The value of n' is of special utility, as it reflects the contribution of Coulombic interactions to the uniform binding of the bound states. This equation was used to analyze salt effects on catalysis by ribonuclease A (RNase A), which is a cationic enzyme that catalyzes the cleavage of an anionic substrate, RNA, with k(cat)/K(M) values that can exceed 10(9) M(-1) s(-1). Lys7, Arg10, and Lys66 comprise enzymic subsites that are remote from the active site. Replacing Lys7, Arg10, and Lys66 with alanine decreases the charge on the enzyme as well as the value of n'. Likewise, decreasing the number of phosphoryl groups in the substrate decreases the value of n'. Replacing Lys41, a key active-site residue, with arginine creates a catalyst that is limited by the chemical conversion of substrate to product. This change increases the value of n', as expected for a catalyst that is more sensitive to changes in the binding of the chemical transition state. Hence, the quantitative analysis of salt-rate profiles can provide valuable insight into the role of Coulombic interactions in enzymatic catalysis.

Catalysis↗

PubMed1988

Quantitative analysis of interstitial alterations in lupus nephritis.

Ninety-eight patients with lupus nephritis followed up for 3 years or more since initial biopsy were the subject of a qualitative and quantitative study of interstitial lesions. Thirty of the 98 patients showed interstitial cell infiltration and/or fibrosis. The initial and final creatinine clearance (Ccr) values were significantly lower in these 30 patients than in the remaining cases. Hypertension and progressive cases were more frequent in the group with interstitial lesions. Histologically, the severity and activity of glomerular lesions and IgG deposition in tubular basement membranes were more severe in the interstitial disease group. On a quantitative analysis of interstitial volumes (IV) in 20 of the 30 patients, there were significant differences in delta IV between the two respective groups with Ccr values greater than 80 ml/min and with those less than 80 both at the initial and final observations (p less than 0.05, each). Further, renal function was significantly lower in 11 cases showing delta IV greater than 17%, than in 9 cases with less than this (p less than 0.01). However, no differences in delta IV were found between the two groups divided according to the degree of severity and activity of glomerular lesions. Further, there was no correlation between renal function, and the severity and activity of glomerular lesions in the 20 cases with interstitial lesions. These results indicate that quantitative analysis is a very useful tool in the evaluation of the functional and prognostic significance of interstitial alterations in lupus nephritis.

Adolescent↗

PubMedDate not supplied

A program package for quantitative analysis of histologic structure and remodeling dynamics of bone.

Quantitative bone histology has become an increasingly valuable tool for the management and diagnosis of metabolic bone disease. A new computer-assisted method for quantitative analysis of bone histology which combines the advantages of discriminatory input by the investigator with a significant reduction of evaluation time is presented. These programs allow the analysis of a sufficient number of subjects from different populations for the establishment of normative data, and are useful in the diagnosis and documentation of the treatment of metabolic bone disease.

Bone Diseases, Metabolic↗

PubMed1998

Intraoperative brain shift and deformation: a quantitative analysis of cortical displacement in 28 cases.

OBJECTIVE: A quantitative analysis of intraoperative cortical shift and deformation was performed to gain a better understanding of the nature and extent of this problem and the resultant loss of spatial accuracy in surgical procedures coregistered to preoperative imaging studies. METHODS: Three-dimensional feature tracking and two-dimensional image analysis of the cortical surface were used to quantify the observed motion. Data acquisition was facilitated by a ceiling-mounted robotic platform, which provided a number of precision tracking capabilities. The patient's head position and the size and orientation of the craniotomy were recorded at the start of surgery. Error analysis demonstrated that the surface displacement measuring methodology was accurate to 1 to 2 mm. Statistical tests were performed to examine correlations between the amount of displacement and the type of surgery, the nature of the cranial opening, the region of the brain involved, the duration of surgery, and the degree of invasiveness. RESULTS: The results showed that a displacement of an average of 1 cm occurred, with the dominant directional component being associated with gravity. The mean displacement was determined to be independent of the size and orientation of the cranial opening. CONCLUSION: These data suggest that loss of spatial registration with preoperative images is gravity-dominated and of sufficient extent that attention to errors resulting from misregistration during the course of surgery is warranted.

Adult↗

PubMed1992

Biochemical studies on 2-deoxy-scyllo-inosose, an early intermediate in the biosynthesis of 2-deoxystreptamine. II. Quantitative analysis of 2-deoxy-scyllo-inosose.

A practical quantitative analysis of 2-deoxy-scyllo-inosose by means of GC-MS selected-ion monitoring (SIM) was exploited in order to assay the enzymatic 2-deoxy-scyllo-inosose formation, the first stage of the 2-deoxystreptamine biosynthesis. Mass spectral fragmentations of 2-deoxy-scyllo-inosose tetra-O-trimethylsilyl (TMS) ether was also investigated by the use of [2,2-2H2]-2-deoxy-scyllo-inosose.

Anti-Bacterial Agents↗

PubMed2001

Ionic and non-ionic contrast agent-mediated endothelial injury. Quantitative analysis of cell proliferation during endothelial repair.

PURPOSE: To quantitatively evaluate endothelial injury in vivo and to assess the time course of cellular repair after endothelial cell exposure to ionic and non-ionic contrast media. MATERIAL AND METHODS: Local changes at the cellular level following intraaortic injection of 1 ml of the ionic contrast agent ioxithalamate or 1 ml of the non-ionic contrast agent iomeprol, each with an iodine content of 300 mg/ml, were investigated using rat endothelium as an in vivo model. A sorbitol solution iso-osmolar to iomeprol served as control. Quantitative analysis of endothelial changes by autoradiography of 3H-thymidine-labeled endothelial cells was assessed after 3, 5 and 10 days, determining the 3H-thymidine index and the DNA synthesis rate. RESULTS: Ioxithalamate showed a clear harmful effect on the endothelium, with an elevated 3H-thymidine index of 7.68% on day 3 and 6.89% on day 5, versus 2.97% on day 3 and 2.55% on day 5 for iomeprol and 2.29% on day 3 and 1.91% on day 5 for the control. CONCLUSION: Ionic contrast agents lead to reversible transient focal endothelial cell injury. No such side effect was detectable for non-ionic contrast agents.

Animals↗

PubMed1979

Quantitative analysis of two-dimensional electrophoretograms.

A method for quantitative analysis of complex film density distributions in autoradiograms is described. The method is intended particularly for measuring the distribution of radioactivity among the proteins resolved by two-dimensional gel electrophoresis but should, of course, be suited to analyzing other two dimensional separations. The film density distribution is first digitized by a high speed rotating drum scanner to generate the image data array that is stored on a magnetic disk. Subsequent analysis involves: 1) data averaging, 2) detection of contours and of their locations, 3) splitting of overlapping spots, 4) conversion of film density to radioactive intensity by means of calibration films, and 5) differentiation and integration to measure the total radioactivity contained in the protein which generates a spot in the autoradiogram. The product of the analysis is a numbered contour map and a table listing coordinates and radioactivity content of each resolved spot. Coordinate transformations for comparison and matching of autoradiograms are also described. A set of utility programs print and graph the data at intermediate stages of the analysis in order to facilitate the checking of procedures and programs.

Autoradiography↗

PubMed1993

Evaluation of storage phosphor imaging for quantitative analysis of 2-D gels using the Quest II system.

The advent of storage phosphor technology has been of considerable benefit to the imaging of gel-separated radiolabeled proteins due to the rapid and quantitative nature of the data acquisition process. Previously, times over one month were required to obtain fluorographs of the same gel to yield data of sufficient dynamic range for quantitative analysis of high-resolution two-dimensional (2-D) gels. As we are in the process of building a human 2-D gel protein database, and therefore have a high throughput of 2-D gels both to image and quantitate using the Quest II software, we undertook an evaluation of a storage phosphor imager, including an evaluation of signal fade. The results of this evaluation demonstrate the feasibility of using such a system, and we describe the procedures that allow us to use this technique for quantitative analysis of many complex 2-D gel patterns. These procedures include a useful batch printing program that allows printing of many images in a non-interactive mode. Examples will be presented of how autoradiography, using storage phosphor plates and the Quest II system, have enabled us to begin building a human 2-D gel protein database including posttranslational modification information, without the previous time constraints associated with such a project.

Autoradiography↗

PubMed1991

[Clinical application of image processing system and quantitative analysis of left ventriculogram and coronary arteriogram].

Currently cine left ventriculography and coronary arteriography are still one of the most important methods in the diagnosis of coronary heart disease and other coronary arterial diseases. An image processing system, called "IA-87 Medical Image Processing System", for quantitative analysis of cine-coronary and left ventricular angiograms has been developed using IBM-PC/AT computer. The major functions of this system are: (1) left ventricular volume determination, i.e. left ventricular contour can be drawn automatically or semi-automatically, the systolic and diastolic volume of the left ventricle are calculated by Simpson's, length-area and chord-length methods. (2) left ventricular segmental wall motion analysis, using rectilinear and polar method, the segmental ejection fraction and normalized segmental contraction are determined. (3) dynamic display of the cardiac cycle. (4) coronary arterial lesion, such as stenosis, can be quantitatively analysed. In a series of cases free from cardiac disease the normal coronary artery (40 cases) and left ventricle (30 cases) were quantitatively analysed using "IA-87 Medical Image Processing System", and the normal value of coronary artery diameter and left ventricular function among Chinese obtained. At the same time, in a series of 45 cases with coronary heart disease (including anterior, posterior wall infarction, and left ventricular aneurysm in 15 respectively), quantitative analysis of the left ventricle was made. The results showed that the system is of significant value for quantitative diagnosis of ischemic heart disease as well as evaluation of therapeutic effect and prediction of prognosis.

Cineangiography↗