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PubMed2001

Quantitative analysis of angiogenesis using confocal laser scanning microscopy.

Angiogenesis is essential for tumor growth and metastasis. Angiogenesis is commonly quantified by measuring microvessel density (MVD) within tumors. In this report, we compared light microscopy with confocal laser scanning microscopy (CLSM) in the qualitative and quantitative analysis of angiogenesis. MVDs were determined manually in a lung tumor xenograft and a normal skeletal muscle using CD31 immunohistochemical staining and light microscopy. Area of three-dimensional representation of microvessels, detected as CD31 immunofluorescence, was measured automatically using computer-assisted CLSM. By manual counting under light microscopy, the relative level of MVD of the lung tumor vs. skeletal muscle was 0.8. However, the corresponding relative level of microvessels was 3.4 as determined by computer-assisted CLSM. Furthermore, the architecture of microvessels was better delineated with CLSM than with light microscopy. We have applied this CLSM method for analyzing the antiangiogenic effect of an anticancer drug, paclitaxel, in the lung tumor xenograft model. We conclude that CLSM is an appropriate method for quantitative and qualitative analysis of microvasculature in normal and tumor tissues.

Angiogenesis Inhibitors↗
PubMed2006

Dynamic and quantitative analysis of choroidal neovascularization by fluorescein angiography.

PURPOSE: In this study, the authors sought to develop and characterize techniques for measuring changes in choroidal neovascularization (CNV) lesion size and fluorescence over time for quantitative analysis of fluorescein angiograms. METHODS: Initial assessment of the quantitative technique was made by retrospectively analyzing digital fluorescein angiograms taken before and 3 months after photodynamic therapy (PDT) for CNV (6 patients, group 1). The method was then applied prospectively to digital fluorescein angiograms (baseline and day 71) obtained on 12 patients taking part in a clinical trial investigating the effect of vascular endothelial growth factor (VEGF) Trap in CNV (group 2). Two masked observers, with the use of image processing, measured the area of hyperfluorescence and fluorescence intensity above background. Values for each image were plotted against time after dye injection to generate curves, and each area under the curve (AUC) was calculated. RESULTS: The physician who treated the patients in group 1 judged the condition of three patients to be improved and of three to be worse 3 months after PDT. Masked retrospective grading of fluorescein angiograms showed an 11% decrease in AUC for fluorescence area and a 32% decrease in AUC for fluorescence intensity in the three patients whose conditions clinically improved but increases of 131% and 292% in the three patients whose conditions clinically worsened. In group 2, a 38% decrease in AUC for fluorescence intensity and a 19% decrease in AUC for fluorescence area were observed in patients who received VEGF Trap compared with increases of 66% (P = 0.004, Mann-Whitney U test) and 21% (P = 0.07) for patients who received placebo. Macular volume decreased by 11% in VEGF Trap-treated patients and increased by 10% in placebo-treated patients (P = 0.03). CONCLUSIONS: This study reports a technique for analysis of change in fluorescence area and intensity over time during fluorescein angiography (FA) using a continuous scale and its application in a clinical setting and a clinical trial. Compared with previous techniques making use of categorical scales, this approach provides an advantage for evaluating responses to treatment that may improve the value of FA as an outcome measure in clinical trials.

Choroidal Neovascularization↗
PubMed1996

Quantitative analysis of substance P-immunoreactive boutons on physiologically characterized dorsal horn neurons in the cat lumbar spinal cord.

A quantitative analysis of substance P (SP)-immunoreactive (IR) terminals contacting physiologically characterized dorsal horn neurons was performed. Three types of neuron were studied: nociceptive specific (NS) from lamina I (n = 3), wide dynamic range (WDR) from laminae II-IV (n = 3), and nonnociceptive (NN) from lamina IV (n = 3). The nociceptive response of focus was a slow, prolonged depolarization to noxious stimuli, because this response was previously shown to be blocked by selective neurokinin-1 (NK-1) receptor antagonists. Ultrastructural immunocytochemistry was used to quantify the relative number of SP-IR boutons apposed to the intracellularly labeled cell per unit of length (density). Densities of the total population (SP immunoreactive+nonimmunoreactive) of apposed boutons were similar in all three regions (cell body, proximal and distal dendrites) for the three functional types of neuron. NS neurons received a significantly higher density of appositions from SP-IR boutons than NN cells in all three regions. However, compared to WDR cells, NS cells possessed a significantly higher density of appositions from SP-IR boutons only in the cell body and proximal dendrites. WDR cells had a higher density of appositions from SP-IR boutons than NN cells, but only in the proximal and distal dendrites. On average, 33.5% of the SP-IR boutons apposed to the cells displayed a synaptic contact. Finally, 30-45% of the SP-IR boutons apposed to the cells colocalized calcitonin gene-related protein (CGRP) immunoreactivity, indicating their primary sensory origin. The data indicate a direct correlation between the amount of SP-IR input and the nociceptive nature of the cells and suggest that SP acts on NK-1 receptors at a short distance from its release site.

Animals↗
PubMed2005

The use of tryptic marker-peptides for the quantitative analysis of cystatin C.

The use of marker-peptides, measured by LC-MS/MS, is investigated for the quantitative analysis of proteins. To that end, cystatin C is chosen as a model protein. It not only functions as a proof of concept protein but the growing interest in cystatin C as a new marker of kidney failure provides a practical application at the same time. The use of trypsin-based proteolysis, to obtain so-called marker-peptides, simplifies the quantification of a protein to the quantification of a single or a number of peptides. Reproducibility of the trypsin proteolysis procedure is vital and has been optimised. A number of the marker-peptides obtained are selected for LC-MS(/MS) analysis. They are completely separated by high-pressure LC allowing maximum selectivity and mass spectrometric multiple reaction monitoring sensitivity. By doing so, linear calibration curves can be obtained for cystatin C over two orders of magnitude. Experiments have been performed on a triple quadrupole mass spectrometer by single ion monitoring (maximum sensitivity) as well as by multiple reaction monitoring (maximum specificity).

Amino Acid Sequence↗
PubMed1996

Quantitative analysis of glomeruli lesions in patients with mesangial proliferative glomerulonephritis.

By using computer imaging analysis system combined with light microscopy, the glomeruli lesions on biopsy specimens sections were quantitatively analysed. The pathological changes of mesangial proliferative glomerulonephritis (MsPGN) in children were quantitatively evaluated and the correlation between the mesangial matrix area (MA) and some clinical data were also analysed. The results indicated that the levels of various glomerular parameters in MsPGN group were higher than those of normal controls. No correlation was found between MA and 24 h urinary protein excretion, but a negative correlation was revealed between MA and estimated GFR. MA was also correlated with the duration of MsPGN recovery. It was suggested that the quantitative analysis of glomerular parameters by computer is a reproducible methods. The parameter of MA may be used for evaluation of the renal function, determination of the duration of therapy and evaluation of prognosis of MsPGN in children.

Adolescent↗
PubMed1993

Quantitative analysis of proton movements associated with the uptake of weak carboxylic acids. The yeast Candida utilis as a model.

A quantitative analysis of the proton movements associated with the initial uptake rate of weak short-chain carboxylic acids was developed in order to estimate proton/carboxylate symports stoichiometries. The yeast Candida utilis was used as a biological model and the deduced equations were applied on the elucidation of the proton/carboxylate symports stoichiometries of lactate, succinate and citrate in a strain of that yeast species at different pH values. At pH 5.0, the proton/lactate and the proton/succinate symport stoichiometry was 1:1. In the cases of the proton/lactate and proton/citrate symports it appears that the stoichiometry ratio increased with increasing extracellular pH.

Biological Transport↗
PubMed2005

Calibration of solid-phase micro-extraction for quantitative analysis by gas chromatography.

Calibration of SPME by the injection of liquid standard solution is a common method for SPME quantitative analysis by gas chromatography. The feasibility of this calibration method relies on the assumption that sample transfer efficiencies are the same for both the liquid injection and the SPME fiber injection. Sample transfer efficiencies for liquid injection and SPME fiber injection were studied in this paper. The results showed that the sample transfer efficiency for liquid injection was affected by several factors, such as the dimensions of the liner, the presence of the wool, and the temperature of the injector. The sample transfer efficiency for SPME fiber injection was affected by the cross-sectional area of the space between the column and the liner, the carrier gas flow rate, and the length of the column inside the liner. An equation was proposed to estimate the sample loss rate for SPME injection. It was found that the use of a direct injection (DI) liner and program temperature vaporizing provides high sample transfer efficiencies, for both liquid injection and SPME fiber injection. When a common SPME straight liner is used, large outer diameter (o.d.) pre-column will help to achieve high sample transfer efficiency.

Acenaphthenes↗
PubMed2000

Pedagogical implications of approaches to study in distance learning: developing models through qualitative and quantitative analysis.

The need for flexibility in the delivery of nurse education has been identified by various initiatives including: widening the entry gate; continuous professional development; and the specialist practitioner. Access to degree level programmes is creating the need to acquire academic credit through flexible learning. The aim of this study was to further develop relationships between the need for guidance, materials design and learning styles and strategies and how these impact upon the construction of meaning. The study is based on interviews of 20 female community nurses purposively selected from the 96 respondents who had previously completed a survey questionnaire. The interviews were underpinned by theories relating to learning styles and approaches to study. Of particular concern was how these variables are mediated by student context, personal factors and materials design, to influence the need for support and guidance. The interview transcripts were first analysed using open and axial coding. Three approaches to study emerged from the data - systematic waders, speedy-focusers and global dippers - which were linked to other concepts and categories. Categories were then assigned numerical codes and subjected to logistical regression analysis. The attributes of the three approaches to study, arising from both qualitative and quantitative analysis, are explained in detail. The pedagogical implications of the three approaches to study are explained by their predicted relationships to other variables, such as support and guidance, organization of study, materials design and role of the tutor. The global dipper approach is discussed in more detail due to its association with a variety of predictor variables, not associated with the other two approaches to study. A feedback model is then developed to explore the impact of guidance on the global dipper approach. The paper makes recommendations for guidance to students using different approaches to study in distance learning.

Adult↗
PubMed2002

Quantitative analysis of factors affecting intraoperative precision and stability of optoelectronic and electromagnetic tracking systems.

This study aims to provide a quantitative analysis of the factors affecting the actual precision and stability of optoelectronic and electromagnetic tracking systems in computer-aided surgery under real clinical/intraoperative conditions. A "phantom-skull" with five precisely determined reference distances between marker spheres is used for all measurements. Three optoelectronic and one electromagnetic tracking systems are included in this study. The experimental design is divided into three parts: (1) evaluation of serial- and multislice-CT (computed tomography) images of the phantom-skull for the precision of distance measurements by means of navigation software without a digitizer, (2) digitizer measurements under realistic intraoperative conditions with the factors OR-lamp (radiating into the field of view of the digitizer) or/and "handling with ferromagnetic surgical instruments" (in the field of view of the digitizer) and (3) "point-measurements" to analyze the influence of changes in the angle of inclination of the stylus axis. Deviations between reference distances and measured values are statistically investigated by means of analysis of variance. Computerized measurements of distances based on serial-CT data were more precise than based on multislice-CT data. All tracking systems included in this study proved to be considerably less precise under realistic OR conditions when compared to the technical specifications in the manuals of the systems. Changes in the angle of inclination of the stylus axis resulted in deviations of up to 3.40 mm (mean deviations for all systems ranging from 0.49 to 1.42 mm, variances ranging from 0.09 to 1.44 mm), indicating a strong need for improvements of stylus design. The electromagnetic tracking system investigated in this study was not significantly affected by small ferromagnetic surgical instruments.

Biophysical Phenomena↗
PubMed2001

Qualitative and quantitative analysis of monocyte transendothelial migration by confocal microscopy and three-dimensional image reconstruction.

A novel method for qualitative and quantitative analysis of monocyte transendothelial migration is described. By labeling monocytes and endothelial cells with different fluorophores, and utilizing confocal microscopy and three-dimensional image reconstruction, transmigrating monocytes were resolved and quantified within a subendothelial collagen gel. Comparison of monocyte migration across endothelial monolayers derived from human brain microvessels versus umbilical veins revealed diapedesis across brain endothelium to be significantly delayed. Inclusion of astrocytes within the subendothelial collagen gel resulted in the formation of an array of astrocytic processes that simulated the glia limitans surrounding brain microvessels in situ, thus yielding a more physiologic paradigm of the blood-brain barrier. By virtue of its unique capacity to provide information on the total number of migrating cells, this analytic approach overcomes significant caveats associated with sampling only aspects of the migration process. The potential adaptability of this method to computer-assisted analysis further enhances its prospective use in high-throughput screening.

Astrocytes↗
PubMed1976

[Quantitative analysis of absorption spectra and spectra of magneto-optical rotatory dispersion of hemoproteins with reference to zero-field splitting. I. Analysis of the divalentcation of deuteroporphyrin in the Q-band region].

I. Analysis of the dication of deuteroporphyrin in the Q-band region. Methods for quantitative analysis of absorption spectra and magneto-optical rotatory dispersion with regard to zero-field splitting of a nearly degenerated term for the latter are described. The methods are based on adaptation of band-form functions to the spectrum using the principle of least squares. Calculation of the zero-field splitting utilizes the formalism evolved by Stephens for strictly degenerated terms (A-terms in the magneto-optical spectrum) which has been further developed to a band-form function depending on zero-field splitting. The curve-form function of the modified A-term contains 4 parameters (zero-field splitting, rotational strength, band width, and the maximum of the band) which have been determined by a computer program. The oscillator and the dipole strength of absorption bands to be calculated simultaneously with the program allows the determination of the magnetic orbital moments of the terms. Exemplified by the dication of deuteroporphyrindimethylester, the significance of zero-field splitting for the recognition of the exact molecule symmetry is demonstrated, and a model of the molecular structure is proposed.

Cations, Divalent↗
PubMed1999

Quantitative analysis of changes occurring in muscle vastus lateralis in patients with heart failure after low-intensity training.

OBJECTIVE: To quantitate the changes occurring in muscle vastus lateralis after exercise training of low intensity adopted for the rehabilitation of patients with chronic heart failure. STUDY DESIGN: Nine consecutive males with a clinical diagnosis of idiopathic dilated and ischemic cardiomyopathy underwent an eight-week period of training. The intensity of the work was calculated as 40% of peak VO2. The program consisted of 30 minutes of cycling three times per week. A cardiopulmonary exercise test, hemodynamic measurements and echocardiographic studies were carried out. Needle biopsies were taken from muscle vastus lateralis before starting and after completing training. Quantitative analysis was carried out on sections stained with ATPase at pH 9.5 for measurement of the lesser diameter of type 1 and 2 fibers (by using an image analyzer) and on UEA 1-stained sections for capillary density and capillary/fiber ratio (by using a frame in the eyepiece of the microscope). The Wilcoxon test was applied to identify significant differences before and after training. Spearman's rank correlation coefficient was also calculated to highlight any correlation between the morphologic data and results of clinical tests. RESULTS: After completing the training program, all the patients experienced an improvement in exercise tolerance and a significant increase (P < .004) in the VO2 and VCO2 peak. Skeletal muscle showed a significant (P < .02) increase in the capillary/fiber ratio. The changes were not significantly correlated with any of the clinical findings. CONCLUSION: Low-intensity training can improve the functional capacity of patients with heart failure while producing only mild morphologic changes in their muscles.

Adult↗
PubMed2000

A systematic and quantitative analysis of PCR template contamination.

A quantitative and systematic analysis is provided for ubiquitously present template DNA interfering with the quantification of human DNA by PCR. Two sources contributing to DNA background were identified. The first one is interpreted as DNA present in chemicals and on equipment and the second as caused by operator handling. The amounts were equivalent to 2.5 and 8.9 pg per mL of sample, and the estimated frequencies of contamination were 65 and 35%, respectively, resulting in an effective limit of detection of 17.4 pg/mL. Below this level--named effective laboratory background--a result could not be considered as authentic. Knowledge of these parameters is important for laboratories that analyze minute amounts of human DNA by PCR for purposes such as quantification, typing, and sequencing.

DNA Fingerprinting↗
PubMed2003

[Qualitative and quantitative analysis of ammonium salts of hexamethylenetetramine and 1,10-phenanthroline].

By use of chemical and physicochemical methods the qualitative and quantitative analysis of bacteriostatic agents N-carbamoylmethylhexamethylenetetraamonium chloride (U-77) and 1-propyl-1,10-phenanthrolinium iodide (X-50) was carried out. The color reactions of these salts with various agents, e. g., concentrated acids, precipitants, oxidizers, indicators, ninhydrin, salts of heavy metals were assesssed. Some characteristic color reactions were found for analysis of quaternary ammonium salts. Experimental results indicate that interaction of N-carbamoylmethyhexamethylenetetraammonium chloride with silver nitrate leads to precipitate of the free silver in the form of a mirror under the proper conditions. It is a result of degradation of hexamethylenetetramine to formaldehyde and its oxidation, which is accompanied by reduction of silver ion to free silver. By use of thin-layer chromatography and ultraviolet spectrophotometry the physicochemical properties of compounds were tested. The suitability of qualitative methods, such as argentometry, mercurimetry, iodometry, extraction photometric analysis was detected. The results suggest, that the most suitable and precise method is argentometry.

Anti-Infective Agents↗
PubMed2003

[Quantitative analysis of resveratrol from grape seeds and grape skins by high performance liquid chromatography method].

In order to perform a quantitative analysis of resveratrol from grape seeds, grape skins and waste residue of grape winery, acetonitrile-water (26:74) was applied as the fluxion phase. The detective wave-length (lambda) was 303 nm. Colume temperature was 35 degrees C. The type of chrimato pattern colume was SupelcosiLTMLC-18 (250 mm x 4.6 mm, 5 microns). Results showed that the contents of resveratrol from grape skins were higher than those of grape seeds. Among different kinds of grape skins, resveratrol contents varied. The reserveratrol content of Suo Suo grape skin was the lowest (0.9850 microgram/g). Among the same kinds of grape skins from the same production area, the resveratrol content was highest in the skin of waste residue of grape winery followed by the fresh grape skin and the old grape skin ranked thirdly, and the differences of resveratrol contents were statistically significant.

Chromatography, High Pressure Liquid↗
PubMed2004

[Quantitative analysis of sigma genes expression in Mycobacterium tuberculosis cultures exposed to rifampicin and isoniazid].

The aim of the study was quantitative analysis of five genes encoding Mycobacterium tuberculosis sigma factors sigA, sigE, sigF, sigH, and sigI as well as the 85B reference gene known as the mycobacterial viability marker, in cultures exposed to rifampicin and isoniazid. The mRN levels were assessed using QRT-PCR technique, in the automated system of real time quantification with the ABI PRISM 7700 Sequence Detector System (TaqMan). The number of each analyzed gene transcript copies was expressed as a number of mRNA per 1 eg of isolated total RNA. In cultures exposed to the tested chemicals the number of 85B mRNA copies declined as compared to the controls (without tested chemicals). There was no detectable expression of sigA and sigI in the control cultures. Both, rifampicin and isoniazid induced expression of sigA and sigI genes. The sigE gene expression increased during exposure to isoniazid and decreased under rifampicin exposure conditions. The sigF mRNA was detected neither in the control culture, nor in cultures exposed to rifampicin or isoniazid. Both tested chemicals caused decrease of sigH expression.

Antibiotics, Antitubercular↗
PubMed1986

[Quantitative analysis of the ultrastructural changes in the organoids of the visual cells of chick embryos exposed to actinomycin D].

A quantitative analysis of ultrastructural changes in organelles of retina differentiating photoreceptors in 10, 11, 12, and 13 day old chick embryos in the presence of Actinomycin was done. Within 10-13th days of development, with the formation of ellipsoid and paraboloid photoreceptors, there is an increase in the areas of mitochondria and endoplasmic reticulum, and in the number of polyribosomes. Actinomycin injection to embryos sharply reduces some cell parameters: single mitochondrial area, areas of endoplasmic reticulum elements, their length and diameters. In addition to disintegration of polyribosomal complexes was noticed in the cell cytoplasm beginning from 1 hour to 24 hours of inhibitor action. A delay in formation of ellipsoid and paraboloid occurred, especially in membrane discs of the external segment of photoreceptor.

Animals↗
PubMed1984

Quantitative analysis and pattern recognition of two-dimensional electrophoresis gels.

We describe a system, both hardware and software, that provides quantitative analysis and data reduction of two-dimensional electrophoresis gels. Image-analysis techniques are used to determine spot intensities and to match spot patterns among many gels. A pattern-recognition program is used to extract the useful information contained in the spot lists. The application of this technology to a study of supernates from bacterial cultures is described.

Bacterial Proteins↗