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At least 757 records · Page 42Linked to original sources
PubMed1991

Rapid Image Analysis Screening Procedure for Identifying Chloroplast Number Mutants in Mesophyll Cells of Arabidopsis thaliana (L.) Heynh.

To analyze the genetic control of the process of chloroplast division, a direct image analysis screening procedure has been developed in which mutants of Arabidopsis thaliana (L.) Heynh. var Landsberg erecta are selected on the basis of abnormal chloroplast number. The selection procedure is based on image analysis thresholding after iodine staining, which facilitates the automatic counting of chloroplasts in isolated mesophyll cells. M2 seedlings are screened for significant deviation from the wild type relationship between mesophyll cell size and chloroplast number. Mutants with both abnormally high and abnormally low chloroplast numbers were identified. Of 3500 individual M2 seedlings screened, 18 mutant lines have been isolated and shown to be stably inherited in three subsequent generations. The most extreme phenotypes show an 80% reduction or a 50% increase in chloroplast number per mesophyll cell.

Journal Article↗
PubMed1992

B-scanning evaluation with image analysis of psoriatic skin.

Ten psoriatic plaques from different subjects were investigated by 20 MHz ultrasound B scanning. Lesions were evaluated before therapy, and after 7 and 15 days of topical treatment with anthralin. Recordings from lesional skin were compared with those from clinically non-involved contralateral skin. Images were assessed by means of a new image analysis program, allowing the conversion of the B-scan image color scale into a numerical amplitude scale, the selection and highlighting of amplitude bands, and the quantification of objects reflecting in a definite amplitude range. B-scanning evaluation of the psoriatic plaque revealed a thickening of the epidermis and dermis, the presence of parallel acoustic shadows in the dermis, and a characteristic hypo-echogenic band corresponding to the papillary dermis. Image processing allowed an exact quantification of the progressive reduction in thickness of the epidermis and dermis and of the hypo-echogenic band observed at skin sites which had been treated with topical substances. Thus, the echographic method with image analysis allows the evaluation of three different parameters of response to topical treatment of psoriatic skin.

Adult↗
PubMedDate not supplied

Gel electrophoresis-autoradiographic image analysis of radiolabeled protein drug concentration in serum for pharmacokinetic studies.

INTRODUCTION: The purpose of this study was to evaluate the feasibility of using gel electrophoresis combined with autoradiographic image analysis for quantitating protein drug concentrations in biological fluid for pharmacokinetic studies. METHODS: Protein drugs were iodinated using the Iodogen reagent and injected into Sprague-Dawley rats for pharmacokinetic evaluation. Serum samples were analyzed using trichloroacetic acid (TCA)-precipitable counts or sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Commercially available precasted Bis-Tris gradient gels were used for SDS-PAGE. Autoradiography of gel samples was performed using phosphoimager and quantitated using the ImageQuant software. RESULTS: The maximum loading volume for protein drugs with molecular weight close to that of albumin ( approximately 70 kDa) was about 1 microl, whereas for protein drugs with larger or smaller molecular weight (i.e., >80 or <40 kDa), the maximum loading volume was up to 20 microl/lane. The optimal exposure time was about 18 h or overnight. Standard curves were constructed using serially diluted dosing solution, which was linear over a 10-fold concentration range with a correlation coefficient of.98. Comparing to the soluble human interleukin-13 receptor (shIL-13R) pharmacokinetic profiles from TCA-precipitable counts, the quantitative gel analysis revealed lower concentrations at later time points and a lower bioavailability from intraperitoneal injection. DISCUSSION: This study provided the first systemic evaluation of gel electrophoresis technology for quantitative protein drug determination in serum and its application in pharmacokinetic studies. The combination of gel electrophoresis with autoradiographic image analysis provided accurate and specific quantitation results. The overnight turnover time allowed routine application in preclinical pharmacokinetic studies.

Animals↗
PubMed1987

Computerized ultrasonic image analysis for placental characterization in normal and hypertensive pregnancies.

A technique has been developed for characterizing ultrasonic images of the human placenta by computerized image analysis. An ultrasonic image data base has been assembled from routine obstetric scans collected from 112 patients. A region within the placenta was manually identified in each image, and a series of parameters which mathematically describe the image texture in the region of interest was calculated. Our pilot study has shown that gestational age at scan, placental position and the presence or absence of hypertension can all be correlated with the mathematically defined textural descriptors of the ultrasonic placental image.

Data Interpretation, Statistical↗
PubMed1991

Measurement of hip prostheses using image analysis. The maxima hip technique.

A computer-based image analysis system has been developed as a research tool in total hip replacement. The system has been programmed to take multiple measurements from coronal plane radiographs. Poor quality radiographic images can be enhanced and standardised. The measurements which can be obtained include stem subsidence, cup migration, cup wear, and stem loosening. Reproducibility and accuracy were +/- 0.01 mm and +/- 0.5 mm respectively. The present application is in retrospective research, but prospective monitoring of radiographs is planned.

Hip Joint↗
PubMed2006

Surface plasmon resonance imaging analysis of protein-receptor binding in supported membrane arrays on gold substrates with calcinated silicate films.

A new method to fabricate supported bilayer membrane (SBM) arrays for surface plasmon resonance (SPR) imaging analysis is demonstrated in this work. Thin silicate films are produced on gold SPR substrates using layer-by-layer assembly, followed by calcination. Etching into the glassified substrates using photolithographic techniques generates nanowells of desirable size and depth. Atomic force microscopy and SPR imaging analysis show that the features are well-defined, and the etching process appears to have a surface smoothing effect. After the wells are oxidized with strong acid, vesicles spontaneously fuse onto them to form supported membranes with a high degree of lateral mobility. Fluorescence recovery after photobleaching measurements yielded a diffusion coefficient of 1.1 mum2/s. To demonstrate the feasibility for high-throughput receptor-ligand interaction analysis, binding of cholera toxin (CT) to SBM arrays containing 5 mol % ganglioside GM1 receptor was carried out with SPR imaging. The results showed excellent well-to-well reproducibility (8% RSD at 60 nM CT) and marked detection sensitivity.

Calcium↗
PubMed1995

Knowledge-based medical image analysis and representation for integrating content definition with the radiological report.

Technology breakthroughs in high-speed, high-capacity, and high performance desk-top computers and workstations make the possibility of integrating multimedia medical data to better support clinical decision making, computer-aided education, and research not only attractive, but feasible. To systematically evaluate results from increasingly automated image segmentation it is necessary to correlate them with the expert judgments of radiologists and other clinical specialists interpreting the images. These are contained in increasingly computerized radiological reports and other related clinical records. But to make automated comparison feasible it is necessary to first ensure compatibility of the knowledge content of images with the descriptions contained in these records. Enough common vocabulary, language, and knowledge representation components must be represented on the computer, followed by automated extraction of image-content descriptions from the text, which can then be matched to the results of automated image segmentation. A knowledge-based approach to image segmentation is essential to obtain the structured image descriptions needed for matching against the expert's descriptions. We have developed a new approach to medical image analysis which helps generate such descriptions: a knowledge-based object-centered hierarchical planning method for automatically composing the image analysis processes. The problem-solving steps of specialists are represented at the knowledge level in terms of goals, tasks, and domain objects and concepts separately from the implementation level for specific representations of different image types, and generic analysis methods. This system can serve as a major functional component in incrementally building and updating a structured and integrated hybrid information system of patient data.(ABSTRACT TRUNCATED AT 250 WORDS)

Artificial Intelligence↗
PubMed1984

Image analysis and DNA content of urothelial cells infected with human polyomavirus.

Human polyomavirus (HPV)-infected cells in the urinary sediment are characterized by large homogeneous basophilic nuclear inclusions, which may mimic the nuclear changes in urothelial cancer. The virus is composed of double-stranded DNA and produces intense green fluorescence of nuclei stained with acridine orange. DNA measurements of Feulgen-stained smears of urinary sediment disclosed that HPV-infected cells have aneuploid DNA values and could not be differentiated from cancer cells on the basis of DNA content alone. On the other hand, computer discriminant analysis performed on high-resolution images of HPV-infected and malignant urothelial cells stained by both the Papanicolaou and Feulgen methods showed that excellent discrimination between the two groups of cells could be achieved with either stain. The misclassification rates ranged from 3% to 9%. This differentiation was almost entirely based upon computer features pertaining to the texture of the nuclear chromatin. This study documented still further the diagnostic value of high-resolution image analysis of cells in the human urinary sediment.

Animals↗
PubMed1985

The G0 in equilibrium G1 transitions of human lymphocytes as monitored by quantitative 14C-uridine autoradiography and high-resolution image analysis.

Human lymphocytes, transferred in culture into medium conditioned with phytohemagglutinin, were studied with the combined use of quantitative 14C-uridine autoradiography and high-resolution image analysis. During the first 24 h before the onset of DNA synthesis it was possible to study pure G0 and G1 populations. The return of the proliferating cells into the G0 state was clearly monitored in an RNA synthesis rate/DNA content plot during 1-week growth. On days 3-6, the proliferation decreased progressively, and more cells accumulated in the quiescent G0 state. Geometric, densitometric, and textural parameters evaluated from the Feulgen-stained nuclei of the same cells indicated that the decondensation/condensation processes of the nuclear chromatin during the G0 in equilibrium G1 transitions paralleled the RNA synthesis activity. The results help to associate descriptors of nuclear morphology, as derived from image analysis, with functional parameters during activation and return to quiescence of human lymphocytes.

Autoradiography↗
PubMed1995

Application of image analysis to the study of skin granulomas.

Histologically- and immunohistochemically- stained paraffin sections of a well-documented collection of infectious skin reactions were studied using a BIOCOM 200 image analysis system. Examples of quantitative evaluation of dermal fibrosis and collagen isotypes pattern, as well as morphometric demonstration of cutaneous vessels or tissue macrophage changes were shown. In addition, the topography of specifically immunostained cell populations was specified in different granulomatous reactions. There was a loss of cytokine positive signal on paraffin sections during the tissue processing. Immunohistochemistry and image analysis were shown to be complementary techniques when applied to pathological material. However, technical improvements will be necessary before routine application of the techniques to the study in situ of the role of cytokines and remodelling enzymes.

Collagen↗
PubMed1997

[Quantification of protein p53 expression by image analysis in 58 cases of colon carcinoma. Study of correlations between sex, age, histology, Dukes stage, DNA content and lymph node invasion].

The analysis of p53 expression has been performed on 58 cases of colonic carcinomas. p53 expression was revealed by immunohistochemistry with the monoclonal antibody DO.7, and its quantification was performed by image analysis on deparaffinized tissue sections treated by microwaves. p53 expression evaluated by images analysis has been compared to visual estimation performed under light microscopy, and an excellent correlation was found between the two methods. No statistical significant relationships were found between the proportion of tumours expressing p53, sex, age (< 70 or > 70 years), histology (well, intermediate or poorly differentiated) and DNA index (< 1.3 or > 1.3) whereas the proportion of tumors expressing p53 was significantly higher in case of metastatic behaviour as well as in the C stage of Dukes classification. p53 expression was also significantly more important in colonic carcinomas with DNA index higher than 1.3 and in case of metastatic behaviour. According to these data, the metastatic behaviour is correlated both with the proportion of tumors expressing p53 and with the level of p53 expression.

Age Factors↗
PubMed2003

Internet (WWW) based system of ultrasonic image processing tools for remote image analysis.

Ultrasonic Doppler color imaging can provide anatomic information and simultaneously render flow information within blood vessels for diagnostic purpose. Many researchers are currently developing ultrasound image processing algorithms in order to provide physicians with accurate clinical parameters from the images. Because researchers use a variety of computer languages and work on different computer platforms to implement their algorithms, it is difficult for other researchers and physicians to access those programs. A system has been developed using World Wide Web (WWW) technologies and HTTP communication protocols to publish our ultrasonic Angle Independent Doppler Color Image (AIDCI) processing algorithm and several general measurement tools on the Internet, where authorized researchers and physicians can easily access the program using web browsers to carry out remote analysis of their local ultrasonic images or images provided from the database. In order to overcome potential incompatibility between programs and users' computer platforms, ActiveX technology was used in this project. The technique developed may also be used for other research fields.

Algorithms↗
PubMed1999

Discrimination of osteoarthritic and rheumatoid human synovial cells in culture by nuclear image analysis.

Rheumatoid arthritic (RA) and osteoarthritic (OA) synovial cells in culture differ in their metabolic and proliferative behaviour. To assess links between these properties and nuclear changes, we used image analysis to study chromatin texture, together with nuclear morphometry and densitometry of OA and RA cells in primary culture. Chromatin pattern at the third day (D3) was heterogeneous and granular with chromatin clumps whereas at the final stage (D11) of culture a homogeneous and finely granular chromatin texture was observed. This evolution indicates global chromatin decondensation. These characteristics were more marked for RA than for OA nuclei. At each culture time, RA nuclei could be discriminated with high confidence from OA ones from parameters evaluating the organization of the chromatine texture. Nuclear image analysis is thus a useful tool for investigating synovial cell biology.

Arthritis, Rheumatoid↗
PubMed1991

Quantification of estrogen receptors on paraffin-embedded tumors by image analysis.

Emphasis on early detection of breast carcinomas has increased the number of instances in which an insufficient amount of tissue is available for biochemical estrogen receptor (ER) assay. Image analysis, used together with immunohistochemistry, introduces the possibility of quantifying molecules, such as ER, in routinely processed tissues. To explore that possibility, sections from 40 formalin-fixed, paraffin-embedded breast carcinomas with biochemically determined ER values were reacted with H222 anti-ER antibody (ER-ICA) and quantified on a CAS 200 image analysis system. A minimum of ten fields comprising at least 15,000 microns 2 of nuclear area were analyzed in each case. If the antigen distribution were not homogeneous, proportional sampling of the different tumor areas was carried out. Of the 31 ER-positive (10 to 344 fmol/mg) tumors, 27 (87%) were immunoreactive by the ER-ICA assay (greater than 5% positive nuclear area), which represents an improvement over simple microscopic evaluation (68%). Bivariate analyses showed statistically significant, albeit only modest, correlation between ER values and the percentages of positive area (r = 0.556) and positive stain (r = 0.518). The following obstacles were found to interfere with a proper correlation: (a) antigen loss during fixation and processing; (b) intratumoral antigenic heterogeneity; and directly associated with it, (c) interobserver variability. Uniform tissue handling or, alternatively, the use of internal controls to compensate for fixation-induced differences, together with thorough assessment of the tissue, should reduce these obstacles and facilitate accurate and reproducible quantification.

Antibodies, Monoclonal↗
PubMed2001

Computerized image analysis: estimation of breast density on mammograms.

An automated image analysis tool is being developed for the estimation of mammographic breast density. This tool may be useful for risk estimation or for monitoring breast density change in prevention or intervention programs. In this preliminary study, a data set of 4-view mammograms from 65 patients was used to evaluate our approach. Breast density analysis was performed on the digitized mammograms in three stages. First, the breast region was segmented from the surrounding background by an automated breast boundary-tracking algorithm. Second, an adaptive dynamic range compression technique was applied to the breast image to reduce the range of the gray level distribution in the low frequency background and to enhance the differences in the characteristic features of the gray level histogram for breasts of different densities. Third, rule-based classification was used to classify the breast images into four classes according to the characteristic features of their gray level histogram. For each image, a gray level threshold was automatically determined to segment the dense tissue from the breast region. The area of segmented dense tissue as a percentage of the breast area was then estimated. To evaluate the performance of the algorithm, the computer segmentation results were compared to manual segmentation with interactive thresholding by five radiologists. A "true" percent dense area for each mammogram was obtained by averaging the manually segmented areas of the radiologists. We found that the histograms of 6% (8 CC and 8 MLO views) of the breast regions were misclassified by the computer, resulting in poor segmentation of the dense region. For the images with correct classification, the correlation between the computer-estimated percent dense area and the "truth" was 0.94 and 0.91, respectively, for CC and MLO views, with a mean bias of less than 2%. The mean biases of the five radiologists' visual estimates for the same images ranged from 0.1% to 11%. The results demonstrate the feasibility of estimating mammographic breast density using computer vision techniques and its potential to improve the accuracy and reproducibility of breast density estimation in comparison with the subjective visual assessment by radiologists.

Biophysical Phenomena↗
PubMed1994

Image analysis software for the detection of preneoplastic and early neoplastic lesions.

Preneoplastic lesions are usually small, and often appear as foci of atypical cells that blend into the surrounding normal tissue without producing a detectable tumor mass. Since these lesions seldom provide adequate tissue for biochemical studies, their detection often depends upon subtle distinctions in cytologic features. Image analysis permits pathologists to obtain quantitative measurements on cytologic and histologic preparations, so that visual impressions can be augmented by quantitative morphometry. Preneoplastic lesions have well-described morphometric features relating to nuclear area, texture, or shape. It is now feasible for every pathology department to capture images of pathologic material with equipment costing less than the price of a microscope. Captured image files can be analyzed using commercial software or software developed in several U.S. government agencies and made freely available to the public. Image analysis has been shown to improve the detection of preneoplastic cells. Recent improvements in the resolution of captured images, in the algorithms that measure preneoplastic descriptors, and in the ease and speed of transmission of images between laboratories, should increase our ability to detect and treat preneoplastic lesions.

Carcinoma in Situ↗