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PubMed2002

Local lattice distortions in spherical carbon nanoparticles as studied by HRTEM image analysis.

The study of lattice distortions in structures with spherical or cylindrical geometry is of growing interest in the field of carbon nanoparticles (onions, nanotubes, etc.). We report an image analysis procedure entirely performed in reciprocal space which provides a global map of the inter-shell distances in carbon nanoparticles. This procedure is applied to carbon nanoparticles with a size of 100 nm that are generated under CVD conditions and exhibit positive as well as negative curvature of the basal lattice planes. These nanoparticles are subjected to intense electron irradiation under the beam of a high-voltage electron microscope with an acceleration voltage of 1.25 MeV. We observe a compression in their centre and a dilation of the outer shells. The reciprocal-space analysis of the high-resolution electron microscopy images opens the way to investigate the stability and equilibrium structure of carbon nanoparticles and to conclude on the formation mechanism.

Journal Article↗
PubMed2004

Morphometric study by image analysis of Ag-stained nucleoli in thyroids bearing proliferating lesions.

The Ag-NOR staining technique and image analysis were used to evaluate morphological parameters (area, perimeter and axis ratio) in nucleoli from normal thyroids and from thyroids bearing proliferating lesions (carcinomas, adenomas and hyperplasias). Regions with normal appearance located close to adenomatous and carcinomatous regions, in the thyroid of every patient, were also analyzed for comparison with the respective pathological regions and with normal thyroids. Statistical analysis of data for the nucleolar area and perimeter allowed the separation of adenomas and carcinomas from hyperplasias and normal tissue but not the two components in each of these two groups. However, if we look at the numbers, a sequence of increasing nucleolar mean areas in the order: normal, hyperplasia, adenoma and carcinoma may be observed, indicating the sequence of increasing rRNA requirements in these different kinds of cells. The axis ratio that denotes the nucleolar shape (round or oblong) did not show significant differences among tissues, suggesting that shape is not important in the characterization of these pathologies. Differences in nucleolar areas and perimeter between normal and affected regions from each patient were statistically significant for adenomas and carcinomas. When these normal regions were compared with the normal thyroids, significant differences were not obtained in the three evaluated parameters. The observations and their importance for histopathological diagnosis are discussed.

Adenocarcinoma↗
PubMed1989

Bendazac lysine in selected types of human senile cataract. A long-term double-masked placebo-controlled clinical trial with multilinear densitometric image analysis of Scheimpflug photographs.

A double-masked placebo-controlled clinical trial with hard data evaluation by image analysis of Scheimpflug photographs taken at baseline and 6, 12 and 18 months after starting treatment was performed to assess the efficacy of bendazac lysine in four different types of senile cataract. The study had a classical split-plot design. For statistical evaluation, the analysis of variance and covariance for repeated measures were used for three different lens sections: anterior capsule and superficial layer, anterior cortex and nucleus. In the entire group of 53 evaluable patients (without separation into cataract-type subgroups), there was a significantly less increase over time in light scattering (i.e. film blackening) of the anterior cortex and nucleus with bendazac lysine than with placebo. There was also a strong trend in favour of the active drug at the anterior capsular level. Patients with water clefts and spokes showed a significantly less light scattering of the anterior capsule and cortex when treated with bendazac lysine. Those with nuclear changes also showed significantly less light scattering of the anterior cortex and nuclear region with the active drug than with placebo. The number of patients with subcapsular and wedge-shaped (cuneiform) cataracts was too small to be adequately assessed by statistical procedures. Nevertheless, there were indications of a beneficial effect of bendazac lysine on all the lens sections in patients with subcapsular cataracts and on the anterior cortical region in those with wedge-shaped cataracts. In conclusion, this study showed that the increase in light scattering over time, i.e. the progression of cataract, is less in bendazac lysine-treated patients than in those treated with placebo.

Adult↗
PubMed2004

Statistical and image analysis of sister chromatid exchange in maize.

The present study reports the use of the fluorescence plus Giemsa (FPG) technique, image analysis and statistical methods to assess the sister chromatid exchanges (SCEs) frequency in maize. Roots derived from germinated maize seeds were treated with BrdU solution and fixed. The slides were prepared by enzymatic cellular dissociation, air-drying technique, stained with Hoechst 33258 fluorochrome, and incubated in salt solution. The chromosomes were irradiated with ultraviolet light and stained with Giemsa solution. The FPG technique associated with digital analysis system was used to measure the length of 597 BrdU-incorporated maize chromosomes and to identify 0.5243 SCE per chromosome. A range from 0 to 4 SCE events were classified and the chi-square test (chi2=1.586, P=0.662) showed a good fit to the hypothesis that the SCEs are independent and random events that follow Poisson distribution. The SCE frequencies in long and short chromosome arms corresponded to a mean value of 0.876 SCE microm(-1). Considering that the maize line used in this study contains 5.78 picogram (pg) DNA (2C value) in interphasic G0/G1 nuclei or 11.56 pg DNA (4C value) in metaphase, and that the DNA mean value corresponds to 0.578 pg/metaphasic chromosome, the analysis suggests an occurrence of approximately 0.9 SCE/pg DNA.

Azure Stains↗
PubMed1977

Computer assisted image analysis of Feulgen-stained cell nuclei from transitional cell carcinoma of the human urinary bladder.

Computer assisted image analysis was performed in Feulgen-stained cell nuclei from 117 transitional cell carcinomas of the human urinary bladder. The results were compared to corresponding findings from a control group consisting of 27 specimens from non-malignant urothelium. Generally, the mean nuclear area in carcinoma specimens was found to be increased as compared to the control group, both in diploid and non-diploid tumours. The concentration and the distribution of nuclear chromatin, and the relative area and content of non-condensed chromatin were dependent on nuclear DNA-content and nuclear area. These nuclear parameters did not give supplementary information which could be used in discriminating benign urothelial cell nuclei from malignant ones. A multiple regression analysis, performed for diploid and non-diploid tumours separately, did not show any significant correlation between the considered nuclear parameters and clinical stage of the tumours or the patient's survival.

Adult↗
PubMed1987

Morphometric quantification of atherosclerotic plaques by computer-assisted image-analysis of histographs.

A method is described for quantifying the amount of atherosclerotic plaque in collapsible blood vessels by a computer-assisted image analysis of cross-sectional contours traced under microscopic visualization. The digitized contours are processed using a computer program that transforms the irregular image of the collapsed vessel into an ideal geometry and then calculates in vivo linear and areal parameters, variables, and ratios. The analysis is based on conventional stereologic principles and utilizes relatively inexpensive and widely available equipment: microscope with drawing tube attachment, digitizing board, microcomputer, monitor, and printer or plotter. Some of the output data include the fraction of vessel lumen occluded by plaque, average thickness of plaque, the fraction of wall surface area covered by plaque, and the ratio of the vessel bore to vessel wall volumes. The error and precision of measuring lumen occlusion and plaque surface area are assessed.

Animals↗
PubMed1997

Stereological image analysis of cultured human melanocytes observed by transmission electron microscopy.

The aims of the study were to write an image analysis (IA) program allowing the stereological quantification of human epidermal melanocyte melanization at the ultrastructural level and to specify the suitable preparative methods, in keeping with IA limits and stereological principles. Micrographs of cultured human melanocytes obtained in transmission electron microscopy were digitized with a scanner. The key step of the designed IA program is a thresholding based on the gray levels. Hence, gray level histograms (pixel frequency as a function of gray level) of melanocyte images exhibit a peak specific to melanin. The gray level thresholding used consists in isolating the melanin pixels that form profiles on a binary image and in storing the numerical data produced for a given melanocyte profile. These primary data are used to calculate numerous parameters via stereology with melanocyte cytoplasm and melanized melanosome as main reference spaces. The most important stereological parameters obtained are v(mi,cy) (melanin volume per average cell), v(mi,m) (melanin volume per average melanized melanosome), and nm (number of melanized melanosomes per average cell), and their validity is discussed. Melanocytes embedded in situ were abandoned for stereological reasons but pelleted melanocytes were found suitable. Using this computerized tool and stereology, we are able to perform quantitative studies producing varied data even from small cell samples. To our knowledge, this is the first stereological approach for quantifying intracellular melanization. A quantitative comparison of spectrophotometrical results (melanin assay) with stereological results obtained in ultraviolet B-irradiated Caucasian epidermal melanocytes will be performed in order to appraise this method.

Cytoplasm↗
PubMedDate not supplied

[CT image analysis for surface reconstruction of the hip joint].

From a sequence of planar CT-pictures of the hip joint the diagnostically relevant contours are extracted on a graphic monitor by means of an image analysis process. To enable this an image-preprocessing has been needed to improve quality of the CT-pictures. From theses contour data, a mathematical surface model of the hip joint will be derived with well-known methods to simulate osteotomy.

Biomechanical Phenomena↗
PubMedDate not supplied

Observer variation in quantification of immunocytochemistry by image analysis.

This paper reports the findings of a study designed to examine observer variation as a source of inaccuracy inherent in the use of computer-assisted image analysis to measure areas of stained tissue. The rat pituitary immunostained for prolactin and galanin was used as an example to estimate patterns of immunoreactivity exhibited by different cell types. Six observers, with differing experience, selected grey level threshold values on 40 fields of images of stained tissue making three repeats of each field. The 40 fields consisted of 20 serial pairs of colocalized fields, one immunostained for prolactin, the other for galanin. The 20 pairs consisted of four pairs from each of five animals. Analysis of observer variation in the selection of threshold values showed large differences in the within- and between-observer variation. Analysis of the components of variance in the estimation of the ratios of stained tissues showed that the major source of variation was the within-observer component. An additional experiment using two observers, where half of the images were compared to the original microscope images before setting threshold levels, showed that the opportunity to make a comparison did not reduce observer variation. It is suggested that any study which uses semi-automatic methods to segment regions of a digital image can benefit from an analysis of this kind so that the sources of variation can be determined to enable maximum discriminating power in future studies.

Animals↗
PubMed2003

Focal segmental sclerotic lesions of the glomerulus in transplanted kidneys assessed using computerized image analysis.

Mechanisms responsible for the development of focal segmental sclerotic lesions of the glomerulus (FSGS lesions) in transplanted kidneys were investigated by morphometric analysis. The mean glomerular area and the interstitial area were measured using computerized image analysis to compare implantation biopsies (so-called 1-h biopsies; 1Bx) with later biopsies (episode Bx; EBx) that had been taken for diagnostic purposes to identify the cause of deteriorating renal function. Groups of patients with (group A, n = 15) or without (group B, n = 10) FSGS lesions were compared. Twelve of 15 in group A and all in group B had lost graft function due to chronic allograft nephropathy. It was found that neither the mean glomerular area nor the interstitial area differed significantly between the two groups in either 1Bx or EBx. The interstitial area was significantly increased (P = 0.007) and the mean glomerular area tended to be increased (P = 0.085) in EBx compared with 1Bx in group A but not in group B. The serum creatinine level at the time of EBx in group A correlated with the interstitial area (P = 0.031) but not the mean glomerular area. However, there was no similar correlation in group B. In conclusion, factors for the development of FSGS lesions in transplanted kidneys may be the increase in interstitial area and possible glomerular hypertrophy following transplantation, rather than pre-existing reduced renal mass of the donor kidneys.

Adult↗
PubMed2005

Image analysis using the fluorochromasia assay to quantify tumor drug sensitivity.

A method of assessing chemosensitivity of tissue utilizing tissue fluorescence and image analysis was implemented to provide a rapid and quantitative means of assessing the effect of drugs on tissue metabolic activity and proliferative capacity. The fluorescent microscopic image captured by a silicon-intensified target (low-light-detecting) camera and linked to an image- processing unit was measured for fluorescent brightness and tumor image area. An established rodent model served to characterize the system's ability to measure serially the tumor's metabolic activity and growth. Further studies on fresh human tumors were conducted with a novel topoisomerase II inhibitor, NC-190. Tumor image area and fluorescent brightness were measured 24 h pretreatment, 48 h posttreatment, and 48 h post-drug removal. Fifty-five percent (28/51) of fresh human tumors showed sensitivity to 48-h exposure to 10, 30, or 100 microM NC-190. The potential benefit of this technique is the ability to predict the response of tumors to chemotherapeutic agents as a laboratory tool for preclinical drug evaluation and clinically prior to the commencement of therapy.

1,2-Dimethylhydrazine↗
PubMed1989

Effect of measurement conditions on quantification of hyperactivated human sperm subpopulations by digital image analysis.

The effect of different measurement conditions on the quantification of hyperactivated (HA) motility in human sperm by digital image analysis (DIA) was determined with respect to chamber depth, temperature, sperm concentration, time in the analysis chamber, culture medium, and type as well as concentration of extracellular protein components. In whole semen, the level of HA (less than 1%) as well as the values for all other motility parameters (curvilinear and straight-line velocity, linearity of forward progression, maximum and mean lateral head amplitude, and beat cross frequency) were independent (p greater than 0.05) of temperature (24 vs. 37 degrees C). In washed sperm samples prepared by in vitro fertilization procedures, the percentage of HA cells was inversely related to measurement temperature and to albumin concentration in the culture medium. The effect of temperature on percentage of HA in washed sperm was reversible. HA analysis of washed sperm from 6 donors (3 ejaculates per donor) under defined DIA assay conditions showed no intra-donor variability (p greater than 0.05) but significant inter-donor variability (donor mean percentages ranging from a low of 3.6 to a high of 28.2). These results indicate that HA is influenced by measurement conditions, that HA is donor-dependent, and that each donor shows a characteristic level of HA.

Culture Media↗
PubMed1992

Proliferative activity of human uterine leiomyoma cells as measured by automatic image analysis.

Proliferative activity of uterine leiomyomas from premenopausal (n = 44) and postmenopausal (n = 12) women was investigated by automatic image analysis on frozen tissue sections using immunohistochemistry with anti-proliferating cell nuclear antigen antibody. The quantitative proliferation index (QPI) in premenopausal leiomyoma cells was significantly (p < 0.025) higher than that in leiomyomas in postmenopausal women. Leiomyomas proliferated most actively during the secretory phase. After the climacterium, leiomyomas showed no proliferative activity in the absence of hormone supply, while combined substitution with estrogen and progestagen considerably increased QPI.

Antibodies, Anti-Idiotypic↗
PubMed1990

The use of computer-assisted video image analysis in the enumeration of immuno-stained cells in tissue sections.

A novel method of computer-assisted video image analysis (VIA) was used to determine the number of immunostained cells in tissue sections. This method permitted an accurate and objective quantification of cells of a particular phenotype. This enumeration was achieved by measuring the area stained by a test monoclonal antibody (such as the T cell marker, CD3) and comparing it with the area stained by a leukocyte common (LCA) monoclonal antibody (CD45). The proportion of T cells within the total leukocyte population in a particular tissue was then calculated. The differentiation of positive (stained) and negative (unstained) cells was uniformly maintained by setting the computer to detect a threshold for staining intensity. This enabled consistency to be maintained within a tissue section as well as between sections stained with the same antibody. In the present study, we determined the phenotype of leukocytes in colonic carcinomas by VIA and compared this with results obtained by normal visual analysis. The VIA method showed distinct advantages over normal visual analysis especially in sections which contained moderate numbers of stained cells.

Antibodies, Monoclonal↗
PubMed1996

Knowledge-based image analysis in the precursors of prostatic adenocarcinoma.

OBJECTIVES: It is the objective of this study to present the use of knowledge-guided procedures in quantitative image analysis and interpretation in histopathology. METHODS: The knowledge-guided procedures were implemented in the form of N-gram encoding methods for the search and detection of areas of atypicality or abnormality in histopathologic sections; they were implemented as expert system for automated scene segmentation based on an associative network with frames at each node. The extraction of histometric features from the basal cell layer of prostatic lesions is presented as an example of automated image interpretation. RESULTS: Rapid search algorithms for lesion detection were able to identify approximately 90% of areas labelled as atypical or abnormal by visual assessment, in lesions of colon, prostate and breast. Automated segmentation of very complex histopathologic imagery was possible with a success rate of approximately 80-90%, in sections of prostatic and colonic lesions. Histometry of the deterioration of the basal cell layer in prostatic lesions provided a monotonic trend curve suitable for the measurement of progression or regression. CONCLUSIONS: Knowledge-guided procedures bring external information, not offered by the imagery itself, to bear on image processing and image analytic methods. This has enabled automated analysis and interpretation of very complex imagery, such as from cribriform glands, resulting in quantitative diagnostic information.

Adenocarcinoma↗
PubMed1994

Computerised image analysis in conjunction with fluorescence microscopy for the study of blood-brain barrier permeability in vivo.

The present paper describes a new method using computerised image analysis techniques for quantification of tracer extravasation over the blood-brain barrier as studied by intravital fluorescence microscopy. Cats were equipped with an open cranial window and continuously infused with fluorescein isothiocyanate-labelled dextran (FITC-dextran, mol. wt. 70,000) to maintain a steady plasma concentration. Several cortical fields were recorded in each experiment and the images stored on video tape for off-line analysis. This procedure, which largely eliminates the superficial pial vasculature and allows extraction of the extravasation areas, consists of the following steps: (1) averaging of images, (2) software shading correction based on the original images for compensation of optical non-uniformity, (3) correction of displacement artefacts, (4) intensity adjustment, (5) generation of subtraction images by subtracting the first image of a series from the subsequent ones, (6) median filtering and thresholding, (7) a length recognition algorithm, and (8) elimination of small areas. Compared to the previously described method, step (2) has been newly developed and steps (4) and (8) added to enhance sensitivity for detecting tracer extravasation. The degree of extravasation in a cortical field at a given time point [E(f) value] was calculated as the mean intensity of the remaining pixels. The E(f) is a quantitative value computed by a fully automatised procedure which takes into account the number, as well as the size and intensity, of extravasation areas in a given cortical field. The E(f) values obtained at different times in a series of experiments were averaged to give the E(I) value.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1999

Quantitative digital image analysis applied to demonstrate the stratified distribution of involucrin in organ cultured human skin.

In this study, quantitative digital image analysis was utilized to measure the optical density of immunostains of involucrin at different depths in the epidermis to obtain reliable ordinal-scaled interpretations of the staining intensity. The distribution of involucrin within the epidermis was investigated in air-liquid interface and submerged skin organ cultures at different time-points. A greyscale calibration procedure to standardize the optical units was used. By the 2nd day of culture, staining of involucrin had shifted markedly towards the mid or basal epidermis. Air-liquid interface cultures showed a less intensive shift than the submerged cultures. Up to the 7th day, involucrin staining remained in the upper epidermis in the air-liquid interface cultures, though weak staining was already observed in the basal epidermis. The results suggest that air-liquid interface conditions maintained physiological conditions better than submerged conditions which result in cultures that may have to increase their involucrin synthesis to improve the barrier function against the surrounding liquid during culture. Alternatively, changes in involucrin synthesis could reflect disturbed homeostasis. Concentrating measurements on certain cell layers might give more detailed information about changes in involucrin expression. Although the detection method was used to study the histochemistry of skin, it could easily be applied to other tissues as well.

Aged↗