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At least 865 records · Page 48Linked to original sources
PubMed1996

Quantitative analysis of the transcription factor AP2 binding to DNA by atomic force microscopy.

Atomic force microscopy (AFM) allows to study the molecular structure of biological macromolecules with nm to A resolutions without crystallization. We show here the applicability of AFM in the quantitative analysis of the molecular mechanisms of DNA/protein interaction: (i) Protein-binding sites can be mapped over a few kilobases of target DNA. (ii) Multimerization state of DNA-binding proteins can be determined simply by measuring the sizes of proteins bound to the DNA. These features are significant advantages over the capabilities provided by conventional techniques in biochemistry and molecular and structural biology.

Animals↗
PubMed1985

Effect of 0.3 ppm ozone exposure on type II cells and alveolar walls of newborn mice: an image-analysis quantitation.

Newborn Swiss-Webster mice were exposed to intermittent 0.3 ppm ozone (O3) for 6 wk, and the lungs of 137 exposed and 138 control animals (275 of the 301 in the colony) were suitable for computer-assisted image-analysis quantitation. Data were obtained on numbers and areas of lactate dehydrogenase stained type II cells, and also area, perimeters, and linear intercepts of the alveolar wall. As noted in an earlier study of adult mice, ozone exposure increased all cell and wall measurements. In contrast to the adult animal findings, there was a greater increase in mean type II cell area (p = 0.07) than in numbers of type II cells, with the latter increase falling short of statistical significance. The increase in cell area at the expense of cell number may largely be due to cell pairing or multicell clustering, events that would mask type II cell hyperplasia. Ozone effects on the type II cell population implicate damage to the type I alveolar lining cells. Moreover, the increases in alveolar wall measurements that were found in both the adult and developing mouse lung imply an alteration of the lung scaffolding, and this raises the question of impaired regeneration of the epithelial lining.

Age Factors↗
PubMed2002

Quantitative analysis of intracellular glutathione levels in murine bone marrow cells by using reverse-phase high-performance liquid chromatography.

Intracellular reduced glutathione (GSH) and oxidized glutathione (GSSG) amounts in murine bone marrow cells were determined by using a simple and rapid quantitative analysis that used reverse-phase high-performance liquid chromatography. Freshly prepared murine bone marrow cells lysed with water were applied to C18 double columns, were eluted with 0.1% trifluoroacetic acid-H2O at 35EC and were detected by ultraviolet absorption (220 nm). GSH and GSSG peaks with retention times of 9.2 and 27.5 min, respectively, were clear and were free of interference from the peaks of contaminated molecules in the cells. The results of this study indicate that our simple method to determine intracellular GSH and GSSG amounts can be used for a small number of cells (>3 x 10(6) cells).

Animals↗
PubMed1992

[Quantitative analysis of the slow phase in congenital nystagmus during convergence].

A previous report described that congenital nystagmus (CN) shows a lower intensity (frequency x amplitude) of spontaneous oscillation during convergence than for distance viewing. However, there has been no detailed report of quantitative analysis of the slow phase of CN during convergence. Therefore, in the present study, the slow phase of CN during convergence was analyzed in 7 patients horizontal and jerky type CN. The time constant of the slow phases were estimated using the repetitive non-linear least square method by a personal computer (NEC, PC 9801). The slow phases of CN for distance viewing were increasing-velocity exponentials, while those of CN during convergence were constant-velocity exponentials. The frequency, amplitude and mean velocity of the slow phase decreased during convergence. Thus, it was suggested that the velocity of the retinal image in CN decreased during convergence.

Adolescent↗
PubMed1996

[Quantitative analysis of spermatogenesis in fine-needle aspirates of the testicle].

It was shown recently that testicular fine-needle aspiration (TFNA) can replace biopsy as a diagnostic tool in male infertility. The aim of this study was to determine whether a method of quantitative analysis of spermatogenesis can be developed based on the cytological elements in the aspirates. TFNA aspirates from markedly oligospermic and azoospermic patients were studied. All spermatogenic cells (spermatogonia, spermatocytes, spermatids and spermatozoa, as well as Sertoli cells) in the aspirates were identified and counted. It was found that: 500 consecutive cells were needed to reach conclusions about the spermatogenic process; the number of Sertoli cells in aspirates was constant in each individual's smears; each spermatogenic cell type could therefore be related to the number of Sertoli cells; the cell type index (CTI: the ratio between the number of cells of each given cell type and the number of Sertoli cells in the count of 500 consecutive cells) indicated the relative appearance of each cell type in the spermatogenic process. Determination of a spermatogenic process index (SPI), reflecting the ratio of the CTI for a given spermatogenic stage to its previous one, may be used in a flow sheet of the spermatogenic process. Assessing these indices for all the spermatogenic cell types in testicular aspirates provides a method for quantitative evaluation of the process of spermatogenesis. It enables expression of testicular pathology quantitatively and it defines various testicular fertility disorders. It can also be used as a guide for surveillance of therapy.

Biopsy, Needle↗
PubMedDate not supplied

[Quantitative analysis of circulatory radiograms using computers].

A technique of quantitative RCG analysis is proposed and tested. It enables the unbiased evaluation of regional hemodynamics phases and of the relation between blood flow rate in arterial and venous beds. The technique is based on calculating the first derivative of the radiocirculogram. The specially developed program may be executed by the computer (ZBM EC).

Angiography↗
PubMed1994

Quantitative analysis of the microstructure of the human cornea and sclera using 2-D Fourier methods.

A two-dimensional (2-D) Fourier analysis was used to characterize the microstructure of the human cornea and sclera. The average centre-to-centre spacing of collagen fibrils was found to be 59 nm for the cornea and 285 nm for the sclera. These results agreed with those obtained by direct measurement using the electron micrographs, and those reported in the literature. The spatial order in the microstructure of the cornea was much greater when compared with that of the sclera. The results of the 2-D Fourier analysis were consistent with the theory of transparency of the eye. The 2-D Fourier analysis will be useful in quantitative characterization and analysis of the complex microstructure of biological cells and tissues in normal development and abnormal pathogenesis.

Cornea↗
PubMed2003

Hydration of hyaluronan polysaccharide observed by IR spectrometry. II. Definition and quantitative analysis of elementary hydration spectra and water uptake.

We recorded a series of spectra of sodium hyaluronan (HA) films that were in equilibrium with their surrounding humid atmosphere. The hygrometry of this atmosphere extended from 0 to 0.97% relative humidity. We performed a quantitative analysis of the corresponding series of hydration spectra that are the difference spectra of the film at a defined hygrometry minus the spectrum of the dried film (hygrometry = 0). The principle of this analysis is to use this series of hydration spectra to define a limited number (four) of "elementary hydration spectra" over which we can decompose all hydration spectra with good accuracy. This decomposition, combined with the measurements of the numbers of H(2)O molecules at the origin in these elementary hydration spectra of the three characteristic vibrational bands of H(2)O, allowed us to calculate the hydration number under different relative humidity conditions. This number compares well with that determined by thermogravimetry. Furthermore, the decomposition defines for each hygrometry value which chemical mechanisms represented by elementary hydration spectra are active. This analysis is pursued by determining for the elementary hydration spectra the number of hydrogen bonds established by each of the four alcohol groups found in each disaccharide repeat unit before performing the same analysis for amide and carboxylate groups. These results are later utilized to discuss the structure of HA at various stages of hydration.

Alcohols↗
PubMed2006

Quantitative analysis of brain asymmetry by using the divergence measure: normal-pathological brain discrimination.

RATIONALE AND OBJECTIVES: The human brain demonstrates approximate bilateral symmetry of anatomy, function, neurochemical activity, and electrophysiology. This symmetry reflected in radiological images may be affected by pathology. Hence quantitative analysis of brain symmetry may enable the normal and pathological brain discrimination. We propose a method based on the Jeffreys divergence measure (J-divergence), which attempts to quantify "approximate symmetry" and also aids to classify the brain as bilaterally symmetrical/asymmetrical (normal/abnormal). MATERIALS AND METHODS: The dataset included studies of 101 patients (59 without detectable pathologies and 42 with different abnormalities). First, the midsagittal plane is computed for the volume data that divides the head into two hemispheres. The J-divergence is calculated from the density functions of intensities of both the hemispheres. Statistical analysis was conducted to find the best distribution for normal/abnormal datasets. RESULTS: Statistical tests showed that the lognormal distribution best characterizes the values of the J-divergence for both normal and abnormal cases, and the threshold value for the Jeffreys divergence measure to classify the brains with and without detectable pathologies is T = 0.007. The threshold value had a sensitivity of 88.1% and specificity of 90.9%. CONCLUSION: The proposed method is fast and simple to compute. The high sensitivity and specificity indicate the results are encouraging. This method can be used for the initial analysis of data, detection of pathology, classification of dataset as presumably normal/abnormal, and localization of abnormality.

Algorithms↗
PubMed1993

Quantitative analysis of 1-naphthol in urine of neonates exposed to mothballs: the value in infants with unexplained anaemia.

In Nigeria, severe NNJ is common in babies exposed to mothballs and other icterogenic agents. High-performance liquid chromatographic (HPLC) method was employed for quantitative analysis of 1 and 2-naphtol in the urine of 50 neonates aged one to 19 days. Five of the 25 babies who had a history of exposure to mothballs, and none of the babies without a history of exposure had 1-naphtol in their urine. The value of 1-naphtol ranged between 0.75 and 11.69 micrograms/ml with mean of 5 +/- 5 micrograms/ml. The overall correlation coefficient (r) between bilirubin values and 1-naphtol was 0.1 while it was 1 in the three G-6-PD deficient infants. The procedure will be very useful in the evaluation of infants with unexplained NNJ, anaemia, acute haemolytic jaundice and haemoglobinuria if naphthalene poisoning is suspected.

Anemia↗
PubMed1996

Further evidence for a unique developmental compartment in the cerebellum of the meander tail mutant mouse as revealed by the quantitative analysis of Purkinje cells.

The cerebellum of the meander tail mutant mouse (mea/mea) is characterized by a relatively normal cytoarchitecture posteriorly with an abrupt transition to an anterior region in which there is abnormal foliation, agranularity, and Purkinje cell (PC) ectopia. This study presents the results of a qualitative and quantitative analysis of the PC in the mea/mea cerebellum. Developmental and morphological analyses reveal that the PC in the anterior region of the mea/mea cerebellum do not form a monolayer during the first week of postnatal development as they do in the wild type mouse. In the adult mea/mea, the dendrites of these ectopic cells are atrophic and disoriented. Quantitative studies in adult animals reveal that while the total number of PC is normal, the number of PC in the affected anterior region of the mea/mea cerebellum is greater than the number of PC in the anterior lobe, as classically defined by the primary fissure, of the normal animal. These data suggest that 1) the developmental morphology of the PC in the anterior region is abnormal, probably due to the lack of granule cells at early postnatal times; 2) the total number of PC in the cerebellum is normal, and 3) the defect is not restricted to the anterior lobe but involves a portion of the posterior lobe. The latter supports the notion that the mutant gene affects a unique developmental compartment in the cerebellum which does not coincide with the classic adult boundary, the primary fissure, between the anterior and posterior lobes.

Animals↗
PubMed1997

Quantitative analysis of electrophoresis data: novel curve fitting methodology and its application to the determination of a protein-DNA binding constant.

A computer program, GelExplorer, which uses a new methodology for obtaining quantitative information about electrophoresis has been developed. It provides a straightforward, easy-to-use graphical interface, and includes a number of features which offer significant advantages over existing methods for quantitative gel analysis. The method uses curve fitting with a nonlinear least-squares optimization to deconvolute overlapping bands. Unlike most curve fitting approaches, the data is treated in two dimensions, fitting all the data across the entire width of the lane. This allows for accurate determination of the intensities of individual, overlapping bands, and in particular allows imperfectly shaped bands to be accurately modeled. Experiments described in this paper demonstrate empirically that the Lorentzian lineshape reproduces the contours of an individual gel band and provides a better model than the Gaussian function for curve fitting of electrophoresis bands. Results from several fitting applications are presented and a discussion of the sources and magnitudes of uncertainties in the results is included. Finally, the method is applied to the quantitative analysis of a hydroxyl radical footprint titration experiment to obtain the free energy of binding of the lambda repressor protein to the OR1 operator DNA sequence.

Bacteriophage lambda↗
PubMed2004

Quantitative analysis of anti-inflammatory and radical scavenging triterpenoid esters in evening primrose oil.

Cold pressed, nonraffinated evening primrose oil (EPO) was recently found to contain lipophilic triterpenoidal esters with radical scavenging and anti-inflammatory properties. A simple and robust method for the quantitative analysis of these 3-O-trans-caffeoyl derivatives of betulinic, morolic, and oleanolic acid was developed and validated. Separation was achieved by normal phase chromatography on a Diol column and with hexane/ethyl acetate (50:50) as eluent. The analytes could be determined directly in the oil matrix, without need of a previous removal of the triglycerides. Normal phase LC ESI-MS with a makeup flow of polar modifier was used for checking the identity and purity of analyte peaks. Samples from 22 commercially available EPOs were analyzed. The average caffeoyl ester contents were 58 mg/100 g in cold pressed oils and 4.7 mg/100 g in partially raffinated oils. In fully raffinated EPO samples, the concentration was below the limit of detection. The influence of extraction temperature on the content of caffeoyl esters in nonraffinated EPO was investigated with seeds of Oenothera biennis and Oenothera lamarckiana, respectively. With O. lamarckiana, the concentration of caffeoyl esters in the oil increased with rising pressure and temperature, whereas no such dependency was found with O. biennis. Microscopic analysis revealed some differences in the histology of the seed testa, which may explain in part the differing behaviors in the extraction experiments. There was a difference between O. biennis and O. lamarckiana oils with respect to the relative amounts of the three esters. The temperature of the extraction process had no effect on the ratio of the compounds.

Anti-Inflammatory Agents↗
PubMed1998

Quantitative analysis of thuringiensin by high-performance liquid chromatography using adenosine monophosphate as an internal standard.

An analytical method for thuringiensin using adenosine monophosphate (AMP) as an internal standard is established. AMP, with high stability and availability, is an appropriate internal standard for thuringiensin quantitative analysis using high-performance liquid chromatography and ultraviolet absorbance detection at 260 nm. A good correlation between the concentration of thuringiensin and the peak-area ratios of thuringiensin to AMP is demonstrated. From this general equation of linear regression line, the concentration of thuringiensin can be assessed in fermentation broth or semi-purified product.

Adenosine↗
PubMed1995

Quantitative analysis of the effect of surface impregnation with biomedical polymers on the proliferation rate of HeLa cells in culture.

The use of biomaterials in biological system was extensively conducted in an in vivo environments. This method limits the evaluation and imposes an obstacle for quantitative analysis of several parameters. The development of tissue culture techniques to evaluate the bioactivity of potential organic compounds alleviated these problems and provided a reliable prediction regarding the biocompatibility of biomaterials when compared with parallel animal testing. The objective of this study is to investigate the effect of various biomedical polymers on the adhesion rate of transformed HeLa cells as a model. The HeLa cells used in this study seeded by following our standard laboratory procedure. A total of 1.5 x 10(5) cells were plated in each of the pretreated wells with various concentrations of (0.01 0.1 and 1% wt/vol) polyvaline (P-Val), polyalanine (P-Ala), polytryptophan (P-Trp), polyasparagine (P-Asn), polyaspartate (P-Asp), poly glycine (P-Gly), and buffered control. At the end of 1,4, and 24 hours the cell viability was determined by hexoamindase activity. The data obtained from this study suggest that (I) the ease of adhesion of HeLa cells were in the following order: P-Val = P-Ala > P-Gly = P-Trp = P-Asp = P-Asn > Control, (II) the rate of HeLa cells spreading was strongly influenced by both incubation time and the polymer concentration, and (III) the surface attachment of HeLa to the polymer were demonstrated to vary depending on their chemical structure and level of microporosity. Thus, overall observation led us to conclude that the surface reactivity of polymer materials be always taken into account in discussing their biocompatibility in vivo.

Biopolymers↗
PubMed2005

[Quantitative analysis of human globin gene expression in beta-thalassemia using real-time RT-PCR].

Whole blood samples were collected from 100 normal healthy adults, from umbilical cord of 33 newborn infants, 111 individuals with beta-thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and 39 with beta-thalassemia major (beta(T)/beta(T),alphaalpha/alphaalpha). Prior to quantitative analysis of globin gene expression, DNA was extracted from all blood samples and used for beta-thalassemia genotype analysis. Different types of beta globin gene mutations were analyzed using reverse dot blotting (RDB) method. Total RNA were extracted and subjected to real-time RT-PCR for quantitative measurement of alpha, beta and gamma globin mRNA using three sets of primers and fluorescent-labeled probes, designed according to the sequences of alpha, beta and gamma human globin gene. Real-time RT-PCR was performed in ABI 7700 system. Following the real-time RT-PCR, the mean values of alpha, beta and gamma globin mRNA were calculated and the ratios of alpha/beta, alpha/(beta + gamma ) and gamma /(beta + gamma ) were determined to characterize the relative expression levels of different globin genes among normal adult, infant, beta-thalassemia minor and beta-thalassemia major patients. The resultant data were analyzed using SPSS 10.0 software to determine statistical significance of human globin gene expression among normal controls and beta-thalassemia patients. Due to vast variations of the mean globin gene mRNA levels among different groups, log conversion of alpha/beta + 1, alpha/(beta + gamma ) + 1 and gamma /(beta + gamma ) +1 was used for statistical analyses and intergroup comparison. The alpha/beta globin gene mRNA ratios were determined to be 4.62+/-1.20, 7.81+/-2.89, 13.51+/-5.12, and 188.24+/-374.04 for normal healthy adult (beta(A)/beta(A),alphaalpha/alphaalpha), infant (beta(A)/beta(A),alphaalpha/alphaalpha), beta- thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and beta-thalassemia major(beta(T)/beta(T),alphaalpha/alphaalpha) respectively. The alpha/(beta+ gamma ) ratios were 4.43+/-1.17, 0.56+/-0.49, 9.62+/-4.37, and 2.14+/-1.58 for normal healthy adult (beta(A)/beta(A),alphaalpha/alphaalpha), infant (beta(A)/beta(A),alphaalpha/alphaalpha), beta- thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and beta- thalassemia major(beta(T)/beta(T),alphaalpha/alphaalpha) respectively. The gamma /(beta+ gamma ) ratios were 0.04+/-0.03, 0.92+/-0.06, 0.28+/-0.18, and 0.95+/-0.04 for normal healthy adult (beta(A)/beta(A),alphaalpha/alphaalpha), infant (beta(A)/beta(A),alphaalpha/alphaalpha), beta- thalassemia minor (beta(T)/beta(A),alphaalpha/alphaalpha) and beta- thalassemia major (beta(T)/beta(T),alphaalpha/alphaalpha) respectively. Following statistical analyses, the alpha/beta and alpha/(beta+ gamma ) globin gene mRNA ratios were significantly different among four different groups (normal adult, normal infant, beta- thalassemia minor and beta- thalassemia major). The gamma /(beta + gamma ) globin gene mRNA ratio was significantly different among all groups except for between infant and beta- thalassemia major patients. Human beta globin gene mRNA levels decrease progressively and dramatically from normal adults to beta-thalassemia patients with beta-thalassemia major having the lowest levels. On the other hand, the gamma globin gene mRNA levels increase progressively from normal adult to beta-thalassemia patients with beta-thalassemia major having the highest levels. Infants have relatively lower levels of beta but higher levels of gamma globin gene mRNA as compared to those in normal adults. Thus, the relative expression levels of alpha, beta or gamma globin genes varied but inter-related among different ages of normal individuals and different beta-thalassemia genotypes.

Adult↗