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At least 235 records · Page 13Linked to original sources
PubMedDate not supplied

Quantitative analysis of hydroxyl radicals in the anterior optic nerve of the cat following transient ischemia.

PURPOSE: Ischemic insults in the optic nerve are relatively common ocular disorders. This study provides quantitative data on the generation of hydroxyl radicals in the anterior optic nerve of the cat during the early reperfusion phase following 90 minutes of ischemia. MATERIALS AND METHODS: Cats were injected intravenously with sodium salicylate that by acting as an hydroxyl radical trap, forms 2,3-dihydroxybenzoic acid (2,3-DHBA). Ischemia was achieved by intraocular pressure (IOP) elevation via cannulation of the anterior chamber. Ischemia was maintained for 60 minutes in 6 eyes and 90 minutes in 12 eyes, followed by 5 minutes of reperfusion. In an additional 6 eyes, ischemia was maintained for 90 minutes without reperfusion. RESULTS: After 90 minutes of ischemia and reperfusion, mean normalized levels of 2,3-DHBA (ie, ng 2,3-DHBA/microg salicylate/mg protein) that represent the levels of hydroxyl radicals were 2.47 times (at least) higher in the anterior optic nerves than in the fellow sham-operated controls (P = 0.03). These levels were 3.9 times (at least) greater than in the corresponding levels after 90 minutes of ischemia without reperfusion (P= 0.005). CONCLUSION: This study provides a quantitative analysis and evidence for the generation of hydroxyl radicals in the optic nerve of the cat following transient ischemia. A quantitative analysis may provide an important tool to detect even relatively small levels of free radicals in the tissues, and to evaluate the relative efficacy of various therapeutic agents in the inhibition of free radical generation following ischemia and reperfusion.

Animals↗
PubMed2002

Quantitative analysis of polymorphic mixtures of ranitidine hydrochloride by Raman spectroscopy and principal components analysis.

Ranitidine hydrochloride exists as two polymorphs, forms I and II, both of which are used to manufacture commercial tablets. Raman spectroscopy can be used to differentiate the two forms but univariate methods of quantitative analysis of one polymorph as an impurity in the other lack sensitivity. We have applied principal components analysis (PCA) of Raman spectra to binary mixtures of the two polymorphs and to binary mixtures prepared by adding one polymorph to powdered tablets of the other. Based on absorption measurements of seven spectral regions, it was found that >97% of the spectral variation was accounted for by three principal components. Quantitative calibration models generated by multiple linear regression predicted a detection limit and quantitation limit for either forms I or II in mixtures of the two of 0.6 and 1.8%, respectively. This study demonstrates that PCA of Raman spectroscopic data provides a sensitive method for the quantitative analysis of polymorphic impurities of drugs in commercial tablets with a quantitation limit of less than 2%.

Drug Evaluation, Preclinical↗
PubMed2005

[Quantitative analysis of complicated casein hydrolysates by high performance size exclusion chromatography].

The enzymatic hydrolysates of casein are so complicated that there has no effective method for quantitative analysis. On the basis of membrane separation and high performance size exclusion chromatography (HPSEC), standard peptides with different relative molecular mass ranges were prepared, and the linear relationships between mass concentration of the standard peptides and the corresponding peak areas were established. Consequently, mass concentration of the different hydrolysates at different reaction time can be accurately calculated. The combination of chromatography and membrane separation is of great importance to the quantitative analysis of the complicated hydrolysates, which can be also applied to the other macromolecular systems, such as carbohydrates.

Amino Acid Sequence↗
PubMed2005

Quantitative analysis of Werner helicase activity using the single-molecule fluorescence detection system MF10S.

We developed a system that uses the single-molecule fluorescence detection system MF10S to assess quantitatively the activity of WRN helicase, the product of the causative gene of Werner syndrome that includes premature ageing. Double-strand DNA substrates labeled with the fluorescence dye TAMRA at the 5' end and with a quencher at the 3' end of the counter strand were incubated with a single trapper oligonucleotide and Werner helicase, and the resultant single DNA fragments labeled with TAMRA produced by the unwinding of WRN helicase were detected using the MF10S. The results using this system and those using polyacrylamide gel electrophoresis were well correlated. The MF10S system provides a quantitative analysis that is much faster, simpler, and more economical than systems using polyacrylamide gel electrophoresis and radioisotopes, and could be used as a quantitative analysis system for Werner helicase and other DNA helicase activities.

DNA Helicases↗
PubMed1994

Quantitative analysis of the two macrophage colony-stimulating factor mRNA expressed in a human stromal cell line by reverse transcription-polymerase chain reaction (RT-PCR).

We established a quantitative analysis system for 4.0 kb and 1.6 kb macrophage colony-stimulating factor (M-CSF) mRNA, using reverse transcription-polymerase chain reaction. Using this system, we performed quantitative analysis of the two mRNAs expressed in the human stromal cell line, KM102, in the resting condition and when stimulated by various concentrations of interferon-gamma (IFN-gamma). The expression of 1.6 kb M-CSF mRNA was more efficiently stimulated by IFN-gamma than that of 4.0 kb M-CSF mRNA. The alternative splicing of a single M-CSF gene has been shown to generate several M-CSF proteins with different localization; we believe that molecular analysis of the transcription products by this system is important to better understand the physiological significance of the different species of M-CSF derived from each mRNA.

Base Sequence↗
PubMed1980

[Qualitative and semi-quantitative analysis of local wall motion abnormalities by gated-blood-pool in comparison to biplane cineventriculography (author's transl)].

Left ventricular wall motion at rest was assessed by the following three methods in 37 patients of whom 12 patients had coronary artery lesions of > 75% and Ecg-signs of transmural MI: A) qualitative analysis of GBP, B) semi-quantitative analysis of GBP, C) qualitative analysis of a biplane cineventriculogram. Sensitivity and specificity of each method were evaluated based on the cineventriculographic findings. Specificity of method A was 83%, of method B 100%. Sensitivity of method A was 88%, of method B 84%. Concordance of methods B and C was 92.8% (167/180 left ventricular segments). Discordance between the two methods was found only in 1 segment judged to be akinetic and in 12 segments judged to be hypokinetic by one of the two methods.

Adult↗
PubMed1982

[A quantitative analysis of the phrenic nerve activities during the cough reflex].

The phrenic nerve activity is an appropriate indicator for the output of the respiratory center as a whole, although a quantitative analysis of each of the frequency band components that constitute the neural activities during the respiratory reflex has not yet been made by other investigators. In the present study, we have made a quantitative analysis of each of the frequency band components of phrenic nerve activity during the cough reflex in anesthetized dogs. The efferent activities of the phrenic nerve were recorded from the central cut end of the phrenic nerve. Each fraction of phrenic nerve activity was separated into bands spanning a range of 100 Hz each by a variable filter and analyzed using a program for the power spectrum. The cough reflex was induced by mechanical stimulation of the tracheal mucosa. In the power spectrum analysis of each frequency band, increase in the power of each of the frequency band components was observed during the cough reflex. Particularly, the power of the 2 approximately 100 Hz band components increased significant as compared with the other frequency band components. Such as increase in the power of the 2 approximately 100 Hz band components toward the other frequency band components during the cough reflex was not observed after an i.v. administration of DMPP and lobeline, but the power increased extended over every frequency band. These findings suggest that the process for integrating the cough reflex was different from that of the other respiratory reflexes and that the present method is useful for investigating the central mechanisms of the cough reflex.

Action Potentials↗
PubMed2003

Semi-quantitative analysis of indigo carmine, using silver colloids, by surface enhanced resonance Raman spectroscopy (SERRS).

The application of surface enhanced resonance Raman spectroscopy (SERRS) to the semi-quantitative analysis of the dye, indigo carmine, has been examined using citrate-reduced silver colloids. Good linear correlations are observed for the dye band at 1580 cm(-1) in the concentration range 10(-7)-10(-5) and 10(-9)-10(-5) mol dm(-3), using laser exciting wavelengths of 514.5 [(R=0.9983)] and 632.8 nm [(R=0.9978)], respectively. At concentrations of dye above 10(-6) M the concentration dependence of the SERRS signals is non-linear due to the coverage of the surface of the colloidal particles by the dye being in excess of a full monolayer. At concentrations above 10(-6) M resonance Raman spectroscopy (RRS) can be employed for the quantitative analysis of the dye. An internal standard was used and a good linear correlation (R=0.997) was observed for the dependence of dye signal intensities at 1580 cm(-1) in the concentration range 10(-5)-10(-4) M using a laser exciting wavelength of 514.5 nm. The limits of detection of indigo carmine by SERRS (514.5 nm), SERRS (632.8 nm) and solution RRS (514.5 nm) are found to be 0.9, 1 and 38 ppm, respectively.

Colloids↗
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↗
PubMedDate not supplied

Quantitative analysis of liposuction with B mode ultrasound.

BACKGROUND: The objective of this study was to determine whether ultrasonography is a reliable method for monitoring subcutaneous fat thickness in the quantitative analysis of liposuction results. METHODS: Subcutaneous fat thicknesses before and 2 months after liposuction in prespecified areas were measured in 14 patients using a 7.5-MHz ultrasound scanner. Pre- and postoperative subcutaneous fat thicknesses were compared statistically. RESULTS: The thicknesses of pre- and postoperative subcutaneous fat layers were statistically different. CONCLUSION: Ultrasound is a valuable tool for perioperative guidance, preoperative planning, and quantitative analysis of the procedure results.

Adipose Tissue↗
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↗