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At least 1,171 records · Page 65Linked to original sources
PubMed1988

Selective induction of peroxisomal enzymes by the hypolipidemic drug bezafibrate. Detection of modulations by automatic image analysis in conjunction with immunoelectron microscopy and immunoblotting.

Quantitative immunoelectron microscopy in conjunction with quantitative analysis of immunoblots have been used to study the effects of bezafibrate (BF), a peroxisome-proliferating hypolipidemic drug, upon six different enzyme proteins in rat liver peroxisomes (Po). Antibodies against following peroxisomal enzymes: catalase, urate oxidase, alpha-hydroxy acid oxidase, acyl-CoA oxidase, bifunctional enzyme (hydratase-dehydrogenase) and thiolase, were raised in rabbits, and their monospecificities were confirmed by immunoblotting. Female Sprague-Dawley rats were treated for 7 days with 250 mg/kg/day bezafibrate and liver sections were incubated with the appropriate antibodies followed by the protein A-gold complex. The labeling density for each enzyme was estimated by automatic image analysis. In parallel experiments immunoblots prepared from highly purified peroxisome fractions of normal and BF-treated rats were incubated with the same antibodies. The antigens were visualized by an improved protein A-gold method including an anti-protein A step and silver amplification. The immunoblots were also quantitated by an image analyzer. The results revealed a selective induction of beta-oxidation enzymes by bezafibrate with thiolase showing the most increase followed by bifunctional protein and acyl-CoA oxidase. The labeling density for catalase and alpha-hydroxy acid oxidase was reduced, confirming fully the quantitative analysis of immunoblots which in addition revealed reduction of uricase. These observations demonstrate that hypolipidemic drugs induce selectively the beta-oxidation enzymes while other peroxisomal enzymes are reduced. The quantitative immunoelectron microscopy with automatic image analysis provides a versatile, highly sensitive and efficient method for rapid detection of modulations of individual proteins in peroxisomes.

Acetyl-CoA C-Acetyltransferase↗
PubMed1987

Electron microscopy and image analysis of the mitochondrial outer membrane channel, VDAC.

The channel protein in the outer membrane of Neurospora crassa mitochondria, VDAC, forms extended planar crystals on the membrane. The arrays, which are induced by phospholipase A2, are polymorphic, varying from parallelogram (P) to near-rectangular (R) geometry with increased phospholipase treatment. Computer-based analysis of projection images of negatively stained VDAC arrays indicates that the protein forms a transmembrane channel in the P array. Comparison of average images of arrays embedded in different negative stains suggests that the bore of the channel is 2-2.5 nm. The locations of functionally important lysine clusters on VDAC are inferred from the effects of succinylation on projection images of arrays negatively stained with phosphotungstate. Projection images of unstained frozen-hydrated arrays indicate the general shape of the channel and suggest each channel is formed by one 31-kDa VDAC polypeptide.

Intracellular Membranes↗
PubMedDate not supplied

Understanding proximal humerus fractures: image analysis, classification, and treatment.

Proximal humerus fractures are difficult to define because of their extreme variability and potential for complexity. We designed a study to evaluate further why this is true. Radiographs of 113 proximal humeral fractures were assessed by 3 knowledgeable observers. The observers were asked to answer independently 9 questions about the fracture, to classify the fracture according to the Neer classification, and to recommend treatment. Two months later, a learning session was held to discuss discrepancies among the observers and to develop learning points to improve analysis of the images. Two months later, the radiographs were reassessed. Developing 10 learning points enhanced the ability to interpret images at the second review and provide more consistent fracture classification with statistically significant improvements. The problem is understanding the images of complex fractures-not the classification system. To enhance consistency in understanding these fractures, imaging of complex fractures must be enhanced.

Adult↗
PubMed2005

Doppler echocardiography flow-velocity image analysis for patients with atrial fibrillation.

Currently, Doppler echocardiography analysis is performed manually. An automated method that analyzes the Doppler signal can potentially improve accuracy and result in a powerful tool for noninvasive evaluation of cardiac hemodynamics, especially for patients with atrial fibrillation, where multiple samples are needed to obtain an accurate averaged measurement. The aim of this study was to develop an automated method for Doppler analysis based on image processing and computer vision algorithms. Images were obtained from the mitral valve and the tricuspid valve Doppler tracings from 45 patients, 20 with normal sinus rhythm and 25 with atrial fibrillation. The proposed algorithm automatically detects the maximal velocity envelope of the spectral Doppler ultrasound tracings. Averaged values for the time velocity integral, peak mitral inflow velocity and peak tricuspid regurgitation velocity were calculated for multiple beats available in a single screen frame. Measurements extracted automatically from the maximal velocity envelope were compared to measurements obtained manually by two expert technicians. High linear correlation (r) was found between the automatically- and the manually-extracted parameters (0.95 < r < 0.99). A smaller variation was found in most cases between the manually-calculated average beat and the automated average beat (bias value between 3.8% and 5.2%) than between the manually-calculated average beat and the selection of a representative beat (bias value between 6.2% and -2.6%). The newly-developed automated method offers a new, accurate and reliable clinical tool, particularly for the assessment of patients with irregular heart rate.

Algorithms↗
PubMed1995

Bacterial growth on surfaces: automated image analysis for quantification of growth rate-related parameters.

A fast routine method for estimating bacterial cell growth rates by using the metachromatic dye acridine orange is described. The method allows simultaneous estimates of cellular RNA and DNA contents of single cells. Acridine orange staining can be used as a nonspecific supplement to quantitative species-specific hybridizations with fluorescence-labelled ribosomal probes to estimate the single-cell concentration of RNA. By automated analysis of digitized images of stained cells, we determined four independent growth rate-related parameters: cellular RNA and DNA contents, cell volume, and the frequency of dividing cells in a cell population. These parameters were used to compare physiological states of liquid-suspended and surface-growing Pseudomonas putida KT2442 in chemostat cultures. The major finding is that the correlation between substrate availability and cellular growth rate found for the free-living cells was not observed for the surface-bound cells; in contrast, the data indicate an almost constant growth rate for attached cells which was independent of the dilution rate in the chemostat.

Journal Article↗
PubMed2002

[Computed image analysis of neutrophils: alkaline phosphatase].

Alkaline phosphatase (AP) activity was detected under optic microscope in neutrophilic leukocyte granules and intergranular cytoplasm. Computer analysis of the image showed that activation of neutrophils in the blood of patients with purulent peritonitis was paralleled by a drastic increase in the activity of AP and its intracellular redistribution. AP granules increased in size and their capacity to conglomeration increased. The enzyme activity increased both in the granules and diffuse zone of the cytoplasm. Total area of AP granules directly correlated with the size of the zone of the enzyme diffuse-granular location.

Alkaline Phosphatase↗
PubMed1989

Use of image analysis to quantitate changes in form of mitochondrial DNA after x-irradiation.

In order to develop a sensitive method that can reliably assess the amount of previous genotoxic exposure, we examined whether relative loss of the supercoiled form of mitochondrial DNA in tissue culture cells could retrospectively reflect exposure to x-irradiation of 375,750, and 1500 roentgens. Five routines of a graphic analysis program named IMAGE developed for the Apple Macintosh II computer were used to densitometrically quantitate the relative amounts of supercoiled and nicked-circular forms of mitochondrial DNA blotted onto nitrocellulose. After x-irradiation, there were dose-dependent losses of supercoiled relative to nicked-circular DNA forms. Further developments in the methodology to evaluate changes in form of mitochondrial DNA should increase the sensitivity and reliability of the dosimetry. The IMAGE program is useful for a wide variety of studies in molecular biology, and is available at no charge.

Animals↗
PubMedDate not supplied

[Sequelae of craniocerebral traumas: CT tomography with digital image analysis].

Using the method digital analysis of CT image (ASOT programme) the cerebrospinal brain index was analysed in a group of 78 patients after past craniocerebral trauma. The studied subjects had had craniocerebral trauma complicated with focal brain contusions and intracerebral and paracerebral haematomas, as well as posttraumatic multiple changes. The control group comprised 12 subjects who had had cerebral concussion. A significant statistically increase of the index was found in the groups with past craniocerebral trauma complicated with intracerebral haematoma or multiple posttraumatic lesions.

Adolescent↗
PubMed2000

Diffusion limited hypoxia estimated by vascular image analysis: comparison with pimonidazole staining in human tumors.

PURPOSE: To assess diffusion limited hypoxia in human tumors using image analysis of vasculature and to compare it with the bioreductive marker pimonidazole as an independent method. MATERIALS AND METHODS: To set up the method, nine rectal adenocarcinomas and ten squamous cell carcinomas were analyzed. To validate the method, ten squamous cell carcinomas of the cervix were analyzed from patients who were injected with pimonidazole and biopsied approximately 24 h later. Sections of the rectal and esophageal tumors were stained for vasculature, while cervix tumor sections were double stained for vasculature and pimonidazole. Tumor areas were delineated on digitized images, and the proportion of tumor tissue greater than a fixed distance from the nearest blood vessel (called diffusion limited fraction, DLF) was then calculated. The proportion of tumor area stained for pimonidazole was also measured. RESULTS: There was a wide variation between tumors in both the vascular-derived DLF and in the pimonidazole-stained fraction. Average DLFs varied between 1.5 and 92% for different tumors, with significant differences between them. The area stained by pimonidazole was significantly smaller than DLF for all tumors. The correlation between pimonidazole area and DLF was significant in three of seven tumors containing > or = 3 images. When images from all tumors (n=123) were analyzed together, the correlation was highly significant (r=0.47, P<0.0001). CONCLUSION: The vascular derived DLF correlates significantly with pimonidazole staining, but there was large scatter. Both methods may underestimate perfusion limited hypoxia.

Adenocarcinoma↗
PubMed1995

Motility and substratum adhesion of Dictyostelium wild-type and cytoskeletal mutant cells: a study by RICM/bright-field double-view image analysis.

To investigate the dynamics of cell-substratum adhesion during locomotion, a double-view optical technique and computer-assisted image analysis has been developed which combines reflection interference contrast microscopy (RICM) with bright-field imaging. The simultaneous recording of cell-substratum contact and cell body contour has been applied to aggregation-competent cells of Dictyostelium discoideum. These cells are distinguished from cells at earlier stages of development by small areas of contact to a substratum. Three questions have been addressed in analysing the locomotion of aggregation-competent cells. (1) What is the relationship between changes in the shape of cells and their contact to a substratum during a chemotactic response? (2) What is the relationship between protrusion and retraction of the cell body, and between local attachment and detachment? (3) Are there differences between wild-type and mutant cells that lack certain cytoskeletal proteins? During a chemotactic response the front region of the amoeba can bend towards the gradient of attractant without being supported by its contact with a surface, which excludes the necessity for gradients of adhesion for the response. The finding that in locomoting cells protrusion of the leading edge often precedes retraction establishes a pioneer role for the front region. The finding that gain of contact area precedes loss provides evidence for the coordination of interactions between the cell surface and a substratum. For comparison with wild-type, aggregation-competent triple mutant cells have been used that lack two F-actin crosslinking proteins, alpha-actinin and 120 kDa gelation factor, and an actin filament fragmenting protein, severin. Disturbances in the spatial and temporal control of cytoskeletal activities have been unravelled in the mutant by RICM and quantified by cross-correlation analysis of attachment and detachment vectors. In order to detect these disturbances, it was essential to analyse cell locomotion on the weakly adhesive surface of freshly cleaved mica.

Animals↗
PubMedDate not supplied

A semiautomated image analysis procedure for the quantification of dental microwear II.

Paleontologists often examine microscopic scratches and pits that form on teeth for indications of the diets of past animals. Most researchers count and measure scratches and pits from photomicrographs to identify microwear patterns for comparison among samples. This paper describes an affordable, available semiautomated image analysis procedure for microwear quantification. An image is downloaded from a scanning electron microscope frame buffer to a microcomputer, and the user identifies microwear features with a mouse-driven pointer. Microwear feature density, dimensions, and orientations are then computed and stored as ASCII files for subsequent data analysis.

Animals↗
PubMed2004

Development of advanced image analysis techniques for the in situ characterization of multiphase dispersions occurring in bioreactors.

Fermentation bioprocesses typically involve two liquid phases (i.e. water and organic compounds) and one gas phase (air), together with suspended solids (i.e. biomass), which are the components to be dispersed. Characterization of multiphase dispersions is required as it determines mass transfer efficiency and bioreactor homogeneity. It is also needed for the appropriate design of contacting equipment, helping in establishing optimum operational conditions. This work describes the development of image analysis based techniques with advantages (in terms of data acquisition and processing), for the characterization of oil drops and bubble diameters in complex simulated fermentation broths. The system consists of fully digital acquisition of in situ images obtained from the inside of a mixing tank using a CCD camera synchronized with a stroboscopic light source, which are processed with a versatile commercial software. To improve the automation of particle recognition and counting, the Hough transform (HT) was used, so bubbles and oil drops were automatically detected and the processing time was reduced by 55% without losing accuracy with respect to a fully manual analysis. The system has been used for the detailed characterization of a number of operational conditions, including oil content, biomass morphology, presence of surfactants (such as proteins) and viscosity of the aqueous phase.

Bacteria↗
PubMed1996

Assessment of testicular spermatozoa morphology by image analysis.

OBJECTIVE: We objectively evaluated the testicular sperm cell morphology. METHODS: The spermatozoa head morphology was evaluated by image analysis as presented on testicular fine-needle aspiration cytology smears. RESULTS: 2,356 spermatozoa heads were classified into six groups, according to different morphology parameters. CONCLUSIONS: This objective method of morphologic assessment of testicular spermatozoa provides an important tool for the evaluation of testicular spermatozoa and can serve as a guide for therapy in male infertility.

Biopsy, Needle↗
PubMed1994

The use of computer-aided image analysis in the evaluation of epithelial nuclear area in the digestive tract of rats.

Semiautomatic computer-aided image analysis was used to measure nuclear area of epithelial cells (surface and glandular epithelium) in various parts of digestive tract in rats. In surface epithelium largest nuclei were observed in duodenum and jejunum. In glandular epithelium largest nuclei were found in duodenum. Nuclear area of epithelial cells within normal mucosa of digestive tract shows differences, that seems to be related to localization and resorption activity.

Animals↗
PubMed1996

[Computer image analysis in the study of endolymphatic hydrops].

In search for an objective method to be used to judge the extent of hydrops, computer image analysis system was used in the study on guinea pig endolymphatic hydrops. The image information of the whole cochlea was collected, then the length of Reissener's membrane and section area of scala media were calculated based upon parameters such as ratio factors and point values. The results were as follows: 1) Hydrops observed with light microscope had no statistical difference. 2) Within 55 days postoperatively, the hydrops grew more obvious with time. 3) The hydrops was more extensive in the basal turn than in the apical turn, though more conspicuous cytopathologic change was found in the apical turn. The conclusions: 1) The current technique is objective, accurate and reliable. 2) Both the length of Reissener's membrane and section area of scala media can be used to measure the extent of hydrops.

Animals↗
PubMed1989

[The peripheral nerves of non-diabetic rats after streptozotocin administration using automatic microscopic image analysis].

Electrophysiologic studies of posterior tibial nerves by averaging method and morphometric investigations of sural nerves by automatic image analysis were performed in 7 non-diabetic rats 42 d after the administration of 55 mg streptozotocin/kg b.w. and in 10 untreated controls. Morphometry of stained semithin sections was carried out with system A 6471-AMBA/R (Robotron, Dresden, G.D.R.). There was no decrease of motor nerve conduction velocity in streptozotocin injected animals. The investigated morphometric parameters showed no significant alterations in the streptozotocin group. The studies show that in streptozotocin diabetic rats electrophysiological and morphological alterations of the peripheral nerve are caused by hyperglycemia but not by direct neurotoxic effects of streptozotocin.

Animals↗
PubMed1993

[Image analysis of arterial vessels of the internal auditory meatus during presenile and aged with hypertension and atherosclerosis].

The image analysis of the arterial vessels of the internal auditory meatus in patients with atherosclerosis and hypertension during presenility and presbycusis was done. The inner and outer diameters of the blood vessels in these patients reduced more markedly than those in the controls. There was a negative correlation between the vessel diameter and correlation age. The lumen of the vessels reduced more in patients with atherosclerosis and hypertension than those patients without these conditions. The tunica adventitia showed fibroid thickness. It suggests that the progress of the vessel changes in patients with presbycusis might be accelerated by atherosclerosis and hypertension.

Aged↗
PubMed1993

[Quantitative study of diabetic retinopathy by computerized image analysis].

Composite fluorescein angiographic pictures of 66 eyes with diabetic retinopathy and nonperfusion areas were studied by computerized image analysis, and the ratio of the nonperfusion area to the disc area was calculated. There were 49 eyes with neovascularization (NV), in which the mean ratio +/- standard error was 46.33 +/- 7.01 (8.15 to 298.26), and the corresponding value in the other 17 eyes without NV was 6.90 +/- 1.31 (2.20 to 21.37), the difference being very significant. When the ratios were under 10, from 10 to 30, or over 30, the percentages of eyes manifesting NV were 13.3%, 81.8% and 100% respectively. In the 49 eyes with NV, the majority of the total 267 neovascular clusters were distributed 4-6 DD away from the optic disc, which itself was involved only in 18 eyes.

Adult↗