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Results for “quantitative analysis”

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At least 73 records · Page 4Linked to original sources
PubMed1993

[Quantitative analysis of gallbladder function using quantitative dynamic radionuclide cholecystography].

The aim of the study is to demonstrate general function of the cholecyst through selected quantitative parameters derived from the quantitative radionuclide cholecystography method, using our own computer software HIDATA, and to evaluate values of specific quantitative parameters in 15 patients presenting with chronic calculous and 15 with chronic acalculous cholecystitis. A control group comprised 10 subjects with no changes on the cholecyst. Of four quantitative parameters calculated during cholecyst filling, the only significant one was the ascending segment slope of the curve from specific ROI, that is, K1 derived from it, because it shows its functional status, depending on the changes in its wall and the lumen content. The most significant parameters which maintain motor function of the cholecyst are ejection fraction (EF) and ejection rate (ER) which are always decreased in chronic cholecystitis, regardless of the presence of calculosis and the number of calculi in the lumen. The ejection fraction is especially decreased in the multiple sclerosis group; it is significantly decreased when compared with acalculous chronic cholecystitis. Our results indicate that a selection of parameters used in clinical practice for the assessment of the cholecyst function is necessary. Our program HIDATA included a large number of parameters of which three were classified as important for the assessment of the cholecyst function (K1, EF, ER), reflecting the process of filling and emptying of the cholecyst and offering reliable and valuable data for the treatment.

Cholecystitis↗
PubMed1994

Quantitative analysis of crystal growth. Tryptophanyl-tRNA synthetase crystal polymorphism and its relationship to catalysis.

We show that quantitative analysis of replicated, full-factorial crystal growth experiments and, by implication, similar studies of a wide variety of other phenomena, can be a powerful tool for analyzing macromolecular systems with complex, interacting dependencies on functionally significant factors. Bacillus stearothermophilus tryptophanyl-tRNA synthetase crystallizes in three different crystal forms depending on the ligands present under otherwise identical conditions. Comparison of crystallographic space groups for complexes with different ligands reveals that the three forms entail at least two very different families of packing arrangements that are correlated with specific changes in the enzyme ligation state. One is associated with the ligand-free enzyme, substrate ligands, and the binding of the activated amino acid; the other results from the presence of high ATP concentrations and/or the synthesis of the unusual acyl-transfer product, tryptophanyl-2'(3') ATP. Together with previous physico-chemical studies of aminoacyl-tRNA synthetases, these observations suggest that the two families are related, respectively, to the biochemical processes of amino acid activation and acyl transfer. Further evidence that the crystal polymorphism results from an underlying protein conformational polymorphism has now been obtained by quantitative analysis of how crystal growth depends on pH and the substrates tryptophan and ATP. The analysis consists first in showing that crystallization conditions for the unliganded protein are very favorable, suggesting that variation in crystal growth induced by pH and substrates under otherwise identical conditions is due to their effects on the protein conformation and not on incidental perturbations of crystal growth, per se. Next, crystal growth experiments are shown to be reproducible enough to support statistical analysis of quantitative scores assigned to the results. Finally, the observed variation in scores can be attributed at high confidence levels chiefly to three effects: that of pH alone, the synergistic effects of pH plus tryptophan, and of tryptophan plus ATP. These statistical inferences are consistent with other biochemical data, and support the conclusions based on crystal packing that representative stages of the enzyme mechanism have been trapped in the different crystal forms. The pH-tryptophan interaction implies that there is a pH-dependent conformational change favoring high affinity substrate binding at high pH. The pH-ATP interaction implies that a subsequent conformational change, not previously considered, occurs between tryptophan activation and acyl transfer.

Adenosine Triphosphate↗
PubMed1996

Quantitative analysis of immunofluorescence and lipofuscin distribution in human cortical areas by dual-channel confocal laser scanning microscopy.

A method for quantitative analysis of confocal laser scanning microscopy (CLSM) images of immunofluorescence and lipofuscin in human brain cortical areas is described. Indirect immunofluorescence was used to show the distribution and density of a synaptic vesicle protein--synaptophysin (p38). Dual channel CLSM was used for imaging immunofluorescence and autofluorescence of lipofuscin granules. Special software was developed for quantitative analysis of the CLSM images. The method has been tested in studies of frontal, temporal, motor, visual, and entorhinal cortices in normal and pathological human brains (Rett syndrome and autism). Using this technique the intensity and amount of p38 immunoreactivity was quantified after subtraction of lipofuscin fluorescence. In normal cortex no statistically significant differences were found for p38 antigen between layers II, III and V. The highest concentration of p38 immunoreactivity was found in the frontal cortex. In Rett syndrome and autistic patients, the p38 immunofluorescence in the investigated cortex areas appeared reduced compared with normal. The software is also suitable for quantitative analysis of double-labelled immunofluorescent specimens in animals without lipofuscin.

Adolescent↗
PubMed1994

Quantitative analysis of planar technetium-99m Sestamibi myocardial perfusion images. Clinical application of a modified method for the subtracton of tissue crosstalk.

Application of the Thallium-201 quantitative analysis method to Tc-99m Sestamibi planar myocardial perfusion images results in oversubtraction of tissue crosstalk, defined as 'activity within the myocardial image, which originated outside the heart'. A modified algorithm, specific for Tc-99m Sestamibi, was applied in 60 patients and the results of quantitative analysis to estimate the risk of coronary artery disease were compared with coronary angiographic findings and with visual analysis. New crosstalk planes were generated based on the results in 20 male healthy volunteers. The results in our study group indicate a higher diagnostic accuracy when circumferential profiles are generated on the basis of maximal counts compared to mean counts. Quantitative analysis was able to predict the presence or absence of CAD as accurately as visual analysis. Odds ratios were 1.07 and 1.32 respectively (P < 0.001) for both quantitative maximal uptake and visual uptake analysis. Sensitivity of visual analysis alone was 89%, increasing to 96% with combined visual/quantitative analysis. Specificity of visual analysis decreased from 79% to 64% with combined analysis. Although only minor differences are seen, the maximal count uptake profiles were found to have additional diagnostic value compared to visual analysis alone.

Adult↗
PubMed1998

[Study on endothelin-1 positive expression and quantitative analysis in lung cancer].

OBJECTIVE: In order to study endothelin-1 (ET-1) positive expression in lung cancer and the relationship between the ET-1 quantitative analysis and the types, grades of lung cancer. METHOD: ET-1 positive expression and quantitative analysis were detected using avidin-biotin-peroxidase complex method and image analysis technology. RESULT: The ET-1 positive expression were mainly located in the cytoplasm in 104 cases with various types of lung cancer. The positive rate of ET-1 in adenocarcinoma, squamous-cell carcinoma and large-cell-lung cancer were 71.4%, 57.1% and 40.0% respectively. The positive rate of ET-1 in small-cell-lung cancer was 21.4%, significantly lower than others. The results of image analysis on adenocarcinoma and squamous-cell carcinoma showed that the lower lung cancer differentiation, the higher ET-1 quantitative. CONCLUSION: There is ET-1 positive expression in all of types of lung cancer, but there is a high ET-1 positive expression in adenocarcinoma and squamous-cell carcinoma. The results of image analysis indicated that ET-1 quantitive expression was somehow related to the differentiation degree of neoplasm, so ET-1 quantitative analysis may be as a monitoring index of adenocarcinoma and squamous-cell carcinoma growing.

Adenocarcinoma↗
PubMed2000

A new technique for the quantitative analysis of cranial suture biology.

OBJECTIVE: Our objective was to assess the ability of the microcomputed tomography scanner to correctly image normal and synostosed cranial sutures at the ultrastructural level. DESIGN AND METHODS: Two specimens of coronal sutures were collected from operative specimens. After appropriate preparation, histological sections were obtained and stained with toluene blue for evaluation. Representative histological sections were compared to microcomputed tomography slices. RESULTS AND CONCLUSIONS: With microcomputed tomography, we successfully imaged one normal and one synostosed human coronal suture and performed a quantitative analysis of these specimens. Microcomputed tomography scanning was found to be a highly accurate imaging device for the evaluation of cranial suture development. Microcomputed tomography offers three-dimensional imaging at the microscopic level and allows for rapid quantitative analysis of bone architecture, including several measurements unavailable through histologic analysis. We believe that microcomputed tomography can play an important role in imaging and in the quantitative analysis of the stereology of bone microarchitecture. Among its advantages, microcomputed tomography is able to image many more slices than are obtainable through histology, and the method is not prone to human error. Microcomputed tomography slices are generated without destruction of the specimen and without loss or corruption of reproducible data. Structure-oriented slices from microcomputed tomography together with cellular-oriented sections from histology are complementary in the overall quantitative analysis of cranial sutures.

Child, Preschool↗
PubMed1986

Quantitative analysis of immunoglobulin-containing cells in gastrointestinal pathology.

The morphometric quantitative analysis of immunoglobulin-containing cells in gastrointestinal biopsies was explored as a possible additional parameter in making the histologic diagnosis of gastrointestinal diseases. Determination of immunoglobulin-containing cells was useful in the differential diagnosis of small intestinal disorders and may be useful in inflammatory diseases of the colon. However, before its general application in diagnosing inflammatory diseases of the colon can be advocated, prospective studies are necessary to determine the specificity and sensitivity of the quantitative analysis of immunoglobulin-containing cells in individual cases of large bowel disease.

Biopsy↗
PubMed1992

Oscillations in glycolysis: multifactorial quantitative analysis in muscle extract.

A multifactorial quantitative analysis of oscillations in glycolysis was conducted in the postmicrosomal supernatant of rat muscle homogenates incubated in the presence of yeast hexokinase. Oscillations in adenine nucleotides, D-fructose 1,6-bisphosphate, triose phosphates, L-glycerol 3-phosphate, 3HOH generation from D-[5-3H]glucose, NADH and L-lactate production were documented. The occurrence of such oscillations were found to depend mainly on the balance between the consumption of ATP associated with the phosphorylation of D-glucose, as catalyzed by both yeast and muscle hexokinase, and the net production of ATP resulting from the further catabolism of D-fructose 6-phosphate, as initiated by activation of phosphofructokinase. The oscillatory pattern was suppressed in the presence of D-fructose 2,6-bisphosphate. It is proposed that the quantitative information gathered in this study may set the scene for further studies in extracts of cells other than myocytes, e.g. hepatocytes and pancreatic islet cells, in which no oscillation of glycolysis was so far observed.

Adenine Nucleotides↗
PubMed2000

Ribosome synthesis in Tetrahymena: a quantitative analysis.

We have performed a detailed quantitative analysis of the transcription and accumulation of ribosomal RNA and ribosomal protein mRNA in the ciliated protozoan Tetrahymena thermophila during changes in growth conditions, and found that: (1) nutritional downshifts lead to a rapid decrease in transcriptional activity whereas nutritional upshifts lead to rapid restoration of transcriptional activity, (2) starvation leads to decreased translation of ribosomal protein mRNA and (3) the rate of ribosomal protein mRNA degradation decreases after a nutritional upshift. We present evidence that the proximal promoters of two ribosomal protein genes and the ribosomal RNA gene compete for binding of nuclear factor(s) in vitro, suggesting that the coordinated regulation of these genes may involve a common set of transcriptional regulators.

Animals↗
PubMed1987

Quantitative analysis of NMR spectroscopic imaging.

A quantitative analysis of recovery curves derived from a series of standard and spectroscopic images is presented. Inversion recovery sequences were modified to produce difference (W-F) images of a water and fat phantom. Adding and subtracting these data from those obtained from standard inversion recovery images resulted in separate recovery curves for the fat and water fractions of emulsions making up the phantom. The procedure yielded consistent reproducible values of longitudinal relaxation times for the constituents of the emulsions.

Emulsions↗
PubMed1998

QU-GENE: a simulation platform for quantitative analysis of genetic models.

MOTIVATION: Classical quantitative genetics theory makes a number of simplifying assumptions in order to develop mathematical expressions that describe the mean and variation (genetic and phenotypic) within and among populations, and to predict how these are expected to change under the influence of external forces. These assumptions are often necessary to render the development of many aspects of the theory mathematically tractable. The availability of high-speed computers today provides opportunity for the use of computer simulation methodology to investigate the implications of relaxing many of the assumptions that are commonly made. RESULTS: QU-GENE (QUantitative-GENEtics) was developed as a flexible computer simulation platform for the quantitative analysis of genetic models. Three features of the QU-GENE software that contribute to its flexibility are (i) the core E(N:K) genetic model, where E is the number of types of environment, N is the number of genes, K indicates the level of epistasis and the parentheses indicate that different N:K genetic models can be nested within types of environments, (ii) the use of a two-stage architecture that separates the definition of the genetic model and genotype-environment system from the detail of the individual simulation experiments and (iii) the use of a series of interactive graphical windows that monitor the progress of the simulation experiments. The E(N:K) framework enables the generation of families of genetic models that incorporate the effects of genotype-by-environment (G x E) interactions and epistasis. By the design of appropriate application modules, many different simulation experiments can be conducted for any genotype-environment system. The structure of the QU-GENE simulation software is explained and demonstrated by way of two examples. The first concentrates on some aspects of the influence of G x E interactions on response to selection in plant breeding, and the second considers the influence of multiple-peak epistasis on the evolution of a four-gene epistatic network. AVAILABILITY: QU-GENE is available over the Internet at (http://pig.ag.uq.edu.au/qu-gene/) CONTACT: m.cooper@mailbox.uq.edu. au

Computer Simulation↗
PubMed1983

The course and prognosis of manic-depressive psychosis: a quantitative analysis of episodes and intervals.

A quantitative analysis of episodes and symptom-free intervals in the course of manic-depressive psychosis was attempted. 1,066 patients who visited Tohoku University Hospital between 1955 and 1965 were investigated by a mail questionnaire and subsequent review of records in their care hospitals. There was no difference between the reply group and non-reply group in terms of demographic status. About 6.2% of patients were chronically ill. Eighteen percent of patients were dead at the time of study. The number of episodes was about three in depression and about seven in bipolar type during twelve years of observation. The length of symptom-free interval between episodes was about five years in depression and two years in bipolar type. There was no difference in the number of episodes or in the length of interval between 1955-1959 group and 1960-1965 group. The change of length was not confirmed between early and late intervals.

Bipolar Disorder↗
PubMed1991

[Quantitative analysis of signal-averaged electrocardiograms].

Quantitative analysis of the high frequency components of the terminal portion of the high-resolution surface QRS was performed in 119 normal subjects (N), 62 patients with ventricular tachycardia (VT) including 20 patients with sustained VT or VF (VTs/VF) and in 565 ischemic and nonischemic cardiac patients (NO-VT). High-resolution surface ECG (SAECG) was obtained during sinus rhythm with noise level below 0.4 microV by ART-1200EPX. The vector magnitude of the filtered and signal-averaged standard bipolar orthogonal leads X, Y, Z (V = square root of X2 + Y2 + Z2) were used for analysis. Total duration of the QRS (QRST), the duration of the low amplitude (40 microV) signals in the terminal portion of the QRS (D40) and the amplitude of the signals in the last 40 ms (V40) were measured at filter settings of both 25Hz and 40Hz by the computer. Specific values for each of the indices were identified at both 25Hz and 40Hz filterings, which could separate N as well as NO-VT from VTs/VF. They were greater than or equal to 120 ms for QRST, greater than or equal to 34 ms for D40 and less than or equal to 25 microV for V40 at 25Hz, greater than or equal to 120 ms for QRST, greater than or equal to 39 ms for D40 and less than or equal to 20 microV for V40 at 40 Hz filtering.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗