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At least 1,369 records · Page 76Linked to original sources
PubMed2004

Evaluation of radial optic neurotomy for central retinal vein occlusion by indocyanine green videoangiography and image analysis.

PURPOSE: To evaluate the effects of radial optic neurotomy (RON) on retinal circulation in patients with central retinal vein occlusion (CRVO) by indocyanine green (ICG) videoangiography and a computer-assisted image analysis. DESIGN: An interventional case series. METHODS: RON was performed in 15 eyes of 15 patients with CRVO. Within 72 hours before the surgery and at 3 months after the surgery, ICG videoangiography was performed with a scanning laser ophthalmoscope, and the images were transferred to a computer. Two measurement points were selected, one on a main retinal artery close to the optic disk and the other on the corresponding retinal vein. At each point, fluorescence intensities were serially measured, and dye dilution curves were obtained. Retinal circulation times (DeltaT(50)) before and after the surgery were calculated. RESULTS: Mean preoperative DeltaT(50) was 6.46 +/- 1.36 seconds, and mean postoperative DeltaT(50) was 6.80 +/- 2.50 seconds. In 8 of 15 eyes, T(50) decreased by 6.8% to 29.6% after the surgery. In the seven eyes that developed chorioretinal anastomosis (CRA) at the site of RON, DeltaT(50) decreased after the surgery. In contrast, DeltaT(50) decreased postoperatively in only one of the eight eyes without CRA. Best-corrected visual acuity improved significantly after the surgery in the group of eyes with improvement in DeltaT(50), but not in the group of eyes without improvement in DeltaT(50). CONCLUSIONS: Some degree of retinal circulation improvement occurred in approximately half of these eyes, which appears to be correlated with the development of CRA.

Aged↗
PubMed2003

Evaluation of murine liver transmission electron micrographs by an innovative object-based quantitative image analysis system (Cellenger).

BACKGROUND: Transmission electron micrographs are widely used to demonstrate tissue damage. However, the results are qualitative and dependent on the experience of the investigator. Recently, a new multiscale object-based quantitative image analyzing systems (Cellenger) has been introduced to study highly textured black-and-white images. It is unknown, whether this system permits the quantitative image analysis of electron micrographs of parenchymal tissue. Therefore, we analyzed whether the Cellenge system permits the quantitative evaluation of electron micrographs of murine liver under normal conditions and after ischemia-reperfusion injury. The results were compared with those obtained by conventional qualitative classification. - METHOD: Transmission electron micrographs from murine liver that had been exposed to isolated reversible ischemia at hypothermic conditions of 4 degrees C, 15 degrees C, 26 degrees C and 37 degrees C, and of sham-operated animals, which served as controls (2 images per animal, n = 3 in each group), were analyzed qualitatively by an investigator with experience in electron microscopy. For quantitative analysis, the Cellenger was used and the following damage parameters were studied: ratio of area of endothelial cell nucleus to area of endothelial cell (N/C ratio), ratio of area of hepatocellular vacuoles to area of total hepatocyte cytoplasm (V/C ratio) and ratio of area of microvilli in the space of Disse to area of the sinusoids (M/S ratio). All values were sampled within one group (n=6) and the data given in [%] (MW +/- SEM). P-values were accepted as significant below 0.05. RESULTS: After normothermic ischemia, all quantitative damage parameter were significantly altered as compared to sham-operated animals (N/C 15 +/- 9% vs. 37 +/- 7%, V/C 18 +/- 4% vs. 0, and M/S 0 vs. 10 +/- 1%) and all hypothermia groups. The qualitative electron micrograph section analysis corresponded very well with these results. CONCLUSION: We demonstrate that an multiscale object-based quantitative analysis of transmission electron micrographs from mouse liver under control conditions and after I/R provide accurate classification of relevant tissue damage parameter. The system is now ready to use for further applications within the field of highly textured electron micrographs.

Animals↗
PubMed2000

Quantitative image analysis of hyaluronan expression in human tooth germs.

The expression of hyaluronan in human tooth germs was studied by using a biotinylated hyaluronan-binding complex and quantitative digital image analysis. At the cap stage, dental papilla exhibited a moderate staining, while intense reaction was observed in the apical portion of presecretory ameloblasts, stellate reticulum, and in dental basement membrane. When the enamel and dentine matrices started to develop, a strong hyaluronan reaction was evident in the young enamel and the apical portion of secretory ameloblasts. No hyaluronan could be detected in the secretory ameloblasts and enamel matrix of the early (9-wk-old) post-natal stage. It is concluded that hyaluronan may play a transitory role in the early phase of the development of the enamel matrix organization. A very weak signal was observed in the wall of dentin tubules, whereas the rest of the dentine matrix was not stained. The odontoblasts and the pulp were also moderately stained, and these reactions gradually decreased with age, suggesting that hyaluronan may also contribute to the development of dentine matrix and pulp.

Ameloblasts↗
PubMed1989

[Automated microscopic image analysis and the prognosis of preneoplasms and carcinomas of the mammary gland].

Studies of preneoplasias and carcinomas of the mammary gland have been conducted by means of automated microscopic image analysis, on the basis of previous results as well as with references to the international literature, for 2 purposes: 1. Determination in the context of a clinical follow-up study of the individual carcinoma risk for patients with proliferative fibrocystic breast disease (mastopathy) and 2. Preparation of an objective automated grading of ductal breast carcinomas for better assessment of prognosis. Against the background of the assumption that the majority of carcinomas and precancerous lesions of the breast originate from the terminal ductal lobular unit, an effort is made to determine, independent severity of the mastopathy, the biological valence of solid, cribriform, and papillary ductal epithelial proliferations (no, possible or inevitable preneoplasia). Proliferation patterns without and with atypical features are checked for their similarity with intraductal and invasive carcinomas (similarity principle) and are additionally examined for differences, depending on localization and distance from tumour (topological principle). Automated histological tumour grading is to distinguish with greater subtlety within the large heterogeneous group of moderately differentiated carcinomas and is to objectify and thus facilitate the difficult task of delimitation of moderately and poorly differentiated carcinomas. Nuclear grading will be the major basis for classification along these lines. Objectified and reproducible tumour grading is believed to be extremely helpful in better prognostication of breast cancer.

Breast Neoplasms↗
PubMed2001

Proliferation and apoptosis measurements by color image analysis based on differential absorption.

Cell proliferation and apoptosis indices are important indicators for the prognosis and treatment of a variety of cancers. A method is described using differential absorption color image analysis to measure proliferation and apoptosis in tumor sections using BrdU (5' bromodeoxyuridine) incorporation and immunohistochemistry and terminal deoxytransferase nick end-labeling (TUNEL). Nuclei were labeled with streptavidin-peroxidase-diaminobenzidine (DAB) secondary detection. The differential absorption method uses a computer-controlled microscope equipped with a tunable filter and digital camera to take advantage of the spectral differences of stained objects of interest. Images collected at defined wavelengths are divided and scaled to form ratio images in which the hematoxylin- or DAB-stained nuclei have intensity ranges far above those of surrounding structures. Using brightness thresholding followed by selection based on nuclear size and shape parameters, binary images were formed of the BrdU/apoptotic-positive tumor and all the tumor nuclei for subsequent counting and calculations of proliferation and apoptotic indices.

Animals↗
PubMed1994

[Feulgen and Rossenbeck staining using a microwave oven for quantification of DNA by image analysis].

A domestic microwave oven was used to modify the Feulgen staining procedure in order to speed up the preparation of cytopathologic smears for the quantification of cell DNA in image analysis. This simple technique needs some precautions concerning the temperature, the hydrolysis time and the position of staining dishes inside the oven must be taken in order to get reproducible results. Thereafter, the conventional staining time can be reduced to 30%. This technique can be applied to cytopathologic smears from various tissues: bladder, prostate, breast, ovary.

Coloring Agents↗
PubMed2006

Langerhans cells in cutaneous tumours: immunohistochemistry study using a computer image analysis system.

Immunohistochemistry, based on antibody anti-S100 protein, was used to evaluate the Langerhans cells (LC) in benign and malign skin neoplasias. These cells were quantitatively estimated using a computer image analysis (OPTIMAS software system, Version 6.1) in skin biopsies diagnosed as basal cell carcinoma (BCC), epidermoid carcinoma (EpC), trichoepithelioma (TE), keratoacanthoma (KA), seborreic keratosis (SK) and actinic keratosis (AK). The antibody anti-S100 protein recognized them. No significant variations were observed in the number of LC among malignant tumour (BCC = 23.25 +/- 5.81 and EpC = 20.88 +/- 4.24). Benign lesions (AK = 33.04 +/- 7.11; TE = 55.74 +/- 9.35; SK = 42.38 +/- 9.92, and KA = 47.62 +/- 10.4) presented a higher number of LC when they were compared among them and to malignant and normal tissues. No significant differences were observed in LC area and volume between benign and malign neoplasias. These results indicate possibly differences in the immunogenicity between benign and malign epidermic tumours. In conclusion, the experimental computer assessment method was reliable and consistent to morphometric analysis of tumoural tissues.

Aged↗
PubMedDate not supplied

Cellular changes in the mammary gland epithelium during the menstrual cycle. A computer image analysis study.

While examining fine needle aspirates of lesions, it became evident that preovulatory aspirates differed from postovulatory ones. Proliferation activity was noted in cells and in fragments aspirated during the luteal phase. In order to verify this observation, pairs of smears obtained during different phases of the menstrual cycle from eight fertile women were studied by computer image analysis. Using discriminant analysis based on nuclear features extracted from the digitized cell images, 84.87% of all cells were correctly classified as preovulatory or postovulatory, according to the smear of origin. When the classification was restricted to only the cells from each woman, a 100% correct identification of cell types was obtained, which supports the visual observation that there are cellular changes in the mammary epithelium correlated to the menstrual cycle. Since some proliferative changes may mimic atypia or malignancy, these findings suggest that it is advisable to perform needle aspirations of breast lesions during the preovulatory phase of the cycle.

Adolescent↗
PubMed1992

Spatial and temporal thyrocyte response to TSH: a computer-assisted image analysis.

Pseudopods at the apical pole of porcine thyroid monolayers in culture were considered as reflecting individual thyrocyte responses to thyrotropin (TSH) stimulation. Scanning electron microscopy and computer-assisted image analysis showed that whatever TSH stimulation was used, the pseudopods were characterized by two populations: P1 with small diameters (2 microns) and P2 with greater diameters (5 microns). The density of P1 rapidly increased to reach a plateau, while P2 continuously increased during stimulation. Two-dimensional pseudopod patterns were compared with random point distributions by means of two topographical parameters: the interpseudopod distances and angles. A factorial analysis of experimental distribution of pseudopods obtained after increasing stimulation times displayed a shift from a nonrandom (10-20 min) to a random (60-90 min) distribution. Clusters of three pseudopods characterized by short distances (6-9 microns) and equilateral organization (angles 40-60 degrees) were observed after a 10-min stimulation. These results suggested that early thyrocyte response to TSH stimulation is characterized by interrelations between three adjoining cells, with the thyrocyte response later appearing as random.

Animals↗
PubMed2006

An electromechanical model of the heart for image analysis and simulation.

This paper presents a new three-dimensional electromechanical model of the two cardiac ventricles designed both for the simulation of their electrical and mechanical activity, and for the segmentation of time series of medical images. First, we present the volumetric biomechanical models built. Then the transmembrane potential propagation is simulated, based on FitzHugh-Nagumo reaction-diffusion equations. The myocardium contraction is modeled through a constitutive law including an electromechanical coupling. Simulation of a cardiac cycle, with boundary conditions representing blood pressure and volume constraints, leads to the correct estimation of global and local parameters of the cardiac function. This model enables the introduction of pathologies and the simulation of electrophysiology interventions. Moreover, it can be used for cardiac image analysis. A new proactive deformable model of the heart is introduced to segment the two ventricles in time series of cardiac images. Preliminary results indicate that this proactive model, which integrates a priori knowledge on the cardiac anatomy and on its dynamical behavior, can improve the accuracy and robustness of the extraction of functional parameters from cardiac images even in the presence of noisy or sparse data. Such a model also allows the simulation of cardiovascular pathologies in order to test therapy strategies and to plan interventions.

Body Surface Potential Mapping↗
PubMed1995

Pulmonary xanthoma. A case report with immunohistologic study and DNA-image analysis.

A case is reported of a xanthoma of the lung in a 32-year-old asymptomatic male. Detailed roentgenographic and immunohistopathologic studies, as well as DNA-image analysis, are presented. The benign nature of this tumor is well recognised and it is generally agreed that conservative local excision with a margin of uninvolved lung is the treatment of choice. The existing literature is reviewed.

Adult↗
PubMed1996

Digital-image analysis of the brain-base arteries in chinchilla, chinchilla laniger (Molina).

This paper attempts to quantitatively characterize the cerebral arterial circle in the chinchilla using a computerized image-analysis system. The sole source of the blood supply to the brain in this animal is the vertebral arteries and the basilar arteries. It was found that the diameter and volume of the basilar artery were over twofold larger than those of cerebral-circle arteries. The total length of the cerebral-circle arteries was approximately two times greater than the length of the basilar artery. A strong correlation between the parameters of the basilar artery and the total volume of the arterial circle was observed, as might be expected. These results suggest that if appropriate geometrical parameters are maintained, the brain can be adequately vascularized, even in the absence of additional blood supply.

Animals↗
PubMed1986

High resolution image analysis of cell nuclei in tissue sections of primary and metastatic carcinomas.

The present study examines whether certain histological tumour types can be differentiated on account of their nuclear image with the aid of automated image analysis. For karyometric investigations three tumour types (adenocarcinomas, squamous cell carcinomas and mammary carcinomas) were chosen, which occur frequently as occult primary tumours. From each type ten primary tumours with their corresponding lymph node metastases were examined. 100 cell nuclei were measured from each case using 4 micron thick paraffin sections stained with gallocyanin-chromalum. For each cell nucleus 21 contour and texture features were determined. Through the application of linear classifiers 41 out of 52 cases (25 primary tumours, 27 metastases) of these three tumour types were correctly classified. Eight cases could not be classified with certainty and only three cases were wrongly classified. In addition, within the group of adenocarcinomas differences due to localisation were detected which allow us to draw conclusions on the seat of the primary tumour.

Adenocarcinoma↗
PubMed1992

Identification of alpha 2-macroglobulin conformational intermediates by electron microscopy and image analysis. Comparison of alpha 2-macroglobulin-thrombin and alpha 2-macroglobulin reacted with cis-dichlorodiammineplatinum(II) and trypsin.

Human alpha 2-macroglobulin (alpha 2M) exists in two well defined, highly distinct conformations and in less well described intermediate conformations. In this study, previously characterized reactions were used to partially or completely transform the conformation of alpha 2M. Electron micrographs of each preparation were subjected to image analysis. Ternary alpha 2M-trypsin (2 mol of trypsin/mol of alpha 2M) was analyzed as a control for the fully transformed state. Correspondence analysis (CORAN) and hierarchical ascendant classification (HAC) generated five image clusters from 330 aligned alpha 2M-trypsin complexes. Average images of each cluster resembled the letter "H" with four nearly equivalent lateral arms. Abnormally shaped lateral arms were not demonstrated by HAC, using a variety of factor sets. In a native polyacrylamide gel electrophoresis system, alpha 2M-thrombin migrated in a diffuse band partially behind alpha 2M-trypsin, suggesting conformational heterogeneity. CORAN and HAC of 733 alpha 2M-thrombin complexes identified two neighboring clusters, the average images of which showed an H-like structure in which one arm was replaced by a globular stain-excluding body. The two alpha 2M-thrombin clusters included 125 images (17.1% of image population). The complete absence of atypical lateral arm structure in the alpha 2M-trypsin clusters suggests that this variation is not the result of orientation or staining artifact. Native alpha 2M was reacted with cis-dichlorodiammineplatinum(II) and then with trypsin to form alpha 2M-Pt-trypsin, a preparation that includes partially transformed alpha 2M structures. CORAN and HAC of 580 alpha 2M-Pt-trypsin complexes generated five clusters, the average images of which showed atypical lateral arm structure equivalent to that demonstrated with alpha 2M-thrombin. The five alpha 2M-Pt-trypsin clusters accounted for 15.2% of the image population. These studies suggest that alpha 2M conformational change intermediates demonstrate common structural characteristics, permitting an elucidation of the steps involved in this complex transformation.

Cisplatin↗
PubMed2007

New advances in fluorochrome sequential labelling of teeth using seven different fluorochromes and spectral image analysis.

Fluorochrome sequential labelling of mineralizing tissues is commonly used in different fields of clinical and basic research. Recently we improved polychrome fluorescent sequential labelling of bone by applying spectral image analysis to discriminate seven different fluorochromes. Although basic mineralization processes of bone and teeth follow comparable principles, the respective tissues differ in terms of matrix composition and mineral assembly. The aim of this study therefore was to investigate the feasibility of this new technique for polychrome sequential labelling of teeth and to demonstrate the advantages in the field of dentistry. Furthermore, the exact labelled area of each fluorochrome could be measured, even in regions of overlapping fluorochromes. The technique presented may provide a basis for further investigations of mineralization processes of different anatomical dental structures.

Animals↗
PubMed1992

Application of image analysis on monolayer cultures of rat hepatocytes: assessment of a chemically inducible G0-G1 cell cycle phase shift.

The phenobarbital induced shift from G0 to G1 cell cycle phases was analyzed in freshly isolated cultured rat hepatocytes by image analysis. Nuclei in situ in monolayers or in an isolated state were stained with quinacrine dihydrochloride. Fluorescence intensity and fluorescence area were recorded in controls and after treatment with phenobarbital (1.5 or 3 mM, 48 h). Reproducible measurements were obtained with the aid of an elaborate background correction and image enhancement procedure and by the construction of individual measuring masks for each nucleus. A complete statistical analysis revealed that in both preparations (isolated nuclei and monolayer cultures, treated and untreated), individual ploidy classes were distinguishable by fluorescence area measurements. Within each ploidy class, the area is modified by the cell density: with increasing cell density the area occupied by a single cell decreases. After phenobarbital treatment, a decrease in size, due to the higher cell density after the mitotic stimulus of the test compound and a decrease in total fluorescence, due to the G0-G1 cell cycle phase shift was recorded. In monolayer cultures, but not in isolated nuclei, two populations of nuclei were discernible suggesting two cell populations, one responding to treatment and one refractive.

Animals↗
PubMed2001

Gamma ray induced DNA damage in human and mouse leucocytes measured by SCGE-Pro: a software developed for automated image analysis and data processing for Comet assay.

The studies reported in this communication had two major objectives: first to validate the in-house developed SCGE-Pro: a software developed for automated image analysis and data processing for Comet assay using human peripheral blood leucocytes exposed to radiation doses, viz. 2, 4 and 8 Gy, which are known to produce DNA/chromosome damage using alkaline Comet assay. The second objective was to investigate the effect of gamma radiation on DNA damage in mouse peripheral blood leucocytes using identical doses and experimental conditions, e.g. lyses, electrophoretic conditions and duration of electrophoresis which are known to affect tail moment (TM) and tail length (TL) of comets. Human and mouse whole blood samples were irradiated with different doses of gamma rays, e.g. 2, 4 and 8 Gy at a dose rate of 0.668Gy/min between 0 and 4 degrees C in air. After lyses, cells were electrophorased under alkaline conditions at pH 13, washed and stained with propidium iodide. Images of the cells were acquired and analyzed using in-house developed imaging software, SCGE-Pro, for Comet assay. For each comet, total fluorescence, tail fluorescence and tail length were measured. Increase in TM and TL was considered as the criteria of DNA damage. Analysis of data revealed heterogeneity in the response of leucocytes to gamma ray induced DNA damage both in human as well as in mouse. A wide variation in TM and TL was observed in control and irradiated groups of all the three donors. Data were analyzed for statistical significance using one-way ANOVA. Though a small variation in basal level of TM and TL was observed amongst human and mouse controls, the differences were not statistically significant. A dose-dependent increase in TM (P<0.001) and TL (P<0.001) was obtained at all the radiation doses (2-8 Gy) both in human and mouse leucocytes. However, there was a difference in the nature of dose response curves for human and mouse leucocytes. In human leucocytes, a linear increase in TM and TL was observed up to the highest radiation dose of 8 Gy. However, in case of mouse leucocytes, a sharp increase in TM and TL was observed only up to 4 Gy, and there after saturation ensued. In human samples, the dose response of both TM and TL showed best fits with linear model (r(TM)=0.999 and r(TL)=0.999), where as in mouse, the best fit was obtained with Sigmoid (Boltzman) model. From the present data on leucocytes with increase in TM and TL as the criteria of DNA damage, it appears that mouse is relatively more sensitive to radiation damage than humans.

Adult↗
PubMed1997

[Video image analysis of AgNORs distribution in the testicular tumor].

For the purpose of exploring the relationship between AgNORs and the biological behaviour of the testicular tumor, the value of enumeration and image analysis of AgNORs has been investigated in 10 normal testicular tissues and 49 cases of testicular tumors. The major findings were: AgNORs value for number, area, mean area, large partical number (LPN) and roundness in normal, benign and malignant tumors had significant difference (P < 0.01). The former four parameters turned larger when the tumor became more malignant, and they were significantly higher in the good prognosis group than in the bad one. LPN was higher in stage III than in stage I and II (P < 0.05), no difference was found between stage I and II. Other parameters had no significant difference in each stage. These results indicate that AgNORs is helpfull in differentiating the benign and malignant testicular tumors, in determining the degree of malignancy and offering an additional prognostic indicator in testicular tumors. Partical numbers, area and LPN were more helpfull. It had no important value in differenciating each stage.

Endodermal Sinus Tumor↗