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At least 19 recordsLinked to original sources
PubMedDate not supplied

FAZYTAN: a system for fast automated cell segmentation, cell image analysis and feature extraction based on TV-image pickup and parallel processing.

Cell location, segmentation and feature extraction of cell images are principal tasks of a high-resolution system for automated cytology. To perform these tasks with high speed, image processing algorithms and the architecture of a processor have to be optimized mutually. This has led to the development of a fast system for the evaluation of cytologic samples based on an optimized TV microscope, a host minicomputer with different peripheral array processors and digital image storages. The processors are optimized in speed for two-dimensional local operations to investigate neighborhood relations and morphology in cell images. Two-dimensional transformations of TV images (288 x 512 x 8 bit) can be carried out within 20 to 200 msec. The processors are able to realize linear filter functions (correlation, convolution) as well as nonlinear functions (median filtering). A set of measurements like area, circumference and connectivity can be derived parallely from one image in 20 msec. The system performs efficient and fast detection and segmentation of cells scanned in one TV frame within one second as well as the extraction of a large number of morphologic features within a few seconds. Based on these procedures, high-resolution analysis of several thousand cells of a sample within one minute will be possible.

Autoanalysis↗
PubMed1983

Influence of staining on fast automated cell segmentation, feature extraction and cell image analysis.

FAZYTAN, a system for fast automated cell segmentation, cell image analysis and extraction of nuclear features, was used to analyze cervical cell images variously stained by the conventional Papanicolaou stain, the new Papanicolaou stain and hematoxylin and thionin only; the last two dyes are used as the nuclear stains in the two versions of the Papanicolaou stain. Other dyes were also tried in cell classification experiments. All cell images in the variously stained samples could be described by the same nuclear features as had been adapted for the discrimination of conventional-Papanicolaou-stained cells. Variances were lower for thionin-stained cells as compared with hematoxylin-stained cells. By application of spectrophotometry, it was confirmed that the spectra of the cytoplasmic counterstains are superimposed on those of the nuclear stains. It appears that a variety of dyes are suitable as cytologic stains for cell classification by the FAZYTAN system, provided that they achieve sufficiently strong nuclear-cytoplasmic contrast by precisely delineating the chromatin texture.

Cell Nucleus↗
PubMed1998

Automatic cell segmentation in cyto- and histometry using dominant contour feature points.

Automatic cell segmentation has various application potentials in cytometry and histometry. In this paper, an automatic cluster (touching) cell segmentation approach using the dominant contour feature points has been presented. Dominant feature points are the locations of indentation on the contour of the cluster. First, dominant feature points on the contour of the cluster are detected by distance profile. Next, using shape features of the cells, these feature points are selected for segmentation. We compared the results of the proposed method with manual segmentation and observed that the method has an overall accuracy about to 82%.

Cell Nucleus↗
PubMed1999

Efficient cell segmentation tool for confocal microscopy tissue images and quantitative evaluation of FISH signals.

In this paper we have presented a semi-automatic method for segmenting 3-D cell nuclei from tissue images obtained using Confocal Laser Scanning Microscope. This microscope can focus at different layers of the specimen and hence a stack of images giving a 3D representation can be obtained. The existing methods for segmenting the cells in 3-D confocal images are highly interactive and, hence, time consuming. We have developed an approach, where, given one segmented image-slice (optical section) of the set of confocal images, the remaining image-slices in the image stack can be automatically segmented in a layered approach. One of the image-slices in an image stack is considered as a representative image-slice. In this image-slice, overlapping boundary pixels are identified interactively while the remaining part of the cell boundary is marked using Laplacian of a Gaussian operator. This interactively traced portion of the boundary is considered as initial boundary for finding the overlapping boundary pixels in the neighboring image-slices. Simple basic search strategy is used for boundary search in the neighboring image-slices. The method minimizes the human interaction and is also found to be efficient and reasonably accurate. Some experimental results are presented to illustrate the usefulness of the technique. We have also given the application of our segmentation method to quantitative evaluation of fluorescence in situ hybridization (FISH) signals. A brief comparative study of visual FISH signal evaluation and the FISH signal counting by automatic image analysis is also given.

Automation↗
PubMedDate not supplied

Characterization of Notch-class gene expression in segmentation stem cells and segment founder cells in Helobdella robusta (Lophotrochozoa; Annelida; Clitellata; Hirudinida; Glossiphoniidae).

To understand the evolution of segmentation, we must compare segmentation in all three major groups of eusegmented animals: vertebrates, arthropods, and annelids. The leech Helobdella robusta is an experimentally tractable annelid representative, which makes segments in anteroposterior progression from a posterior growth zone consisting of 10 identified stem cells. In vertebrates and some arthropods, Notch signaling is required for normal segmentation and functions via regulation of hes-class genes. We have previously characterized the expression of an hes-class gene (Hro-hes) during segmentation in Helobdella, and here, we characterize the expression of an H. robusta notch homolog (Hro-notch) during this process. We find that Hro-notch is transcribed in the segmental founder cells (blast cells) and their stem-cell precursors (teloblasts), as well as in other nonsegmental tissues. The mesodermal and ectodermal lineages show clear differences in the levels of Hro-notch expression. Finally, Hro-notch is shown to be inherited by newly born segmental founder cells as well as transcribed by them before their first cell division.

Animals↗
PubMed1996

An iterative algorithm for cell segmentation using short-time Fourier transform.

In this paper, an iterative cell image segmentation algorithm using short-time Fourier transform magnitude vectors as class features is presented. The cluster centroids of the magnitude vectors are obtained by the K-means clustering method and used as representative class features. The initial image segmentation classifies only those image pixels whose surrounding closely matches a class centroid. The subsequent procedure iteratively classifies the remaining image pixels by combining their spatial distance from the regions already segmented and the similarities between their corresponding magnitude vectors and the cluster centroids. Experimental results of the proposed algorithm for segmenting real cell images are provided.

Algorithms↗
PubMed2005

Whole cell segmentation in solid tissue sections.

BACKGROUND: Understanding the cellular and molecular basis of tissue development and function requires analysis of individual cells while in their tissue context. METHODS: We developed software to find the optimum border around each cell (segmentation) from two-dimensional microscopic images of intact tissue. Samples were labeled with a fluorescent cell surface marker so that cell borders were brighter than elsewhere. The optimum border around each cell was defined as the border with an average intensity per unit length greater that any other possible border around that cell, and was calculated using the gray-weighted distance transform. Algorithm initiation requiring the user to mark two points per cell, one approximately in the center and the other on the border, ensured virtually 100% correct segmentation. Thereafter segmentation was automatic. RESULTS: The method was highly robust, because intermittent labeling of the cell borders, diffuse borders, and spurious signals away from the border do not significantly affect the optimum path. Computer-generated cells with increasing levels of added noise showed that the approach was accurate provided the cell could be detected visually. CONCLUSIONS: We have developed a highly robust algorithm for segmenting images of surface-labeled cells, enabling accurate and quantitative analysis of individual cells in tissue.

Algorithms↗
PubMed1985

Block of sodium currents by the calcium antagonist D600 in human heart cell segments.

The effects of micromolar concentrations of racemic D600 on the transmembrane inward sodium current (INa) were investigated in voltage clamped, intracellularly perfused, human heart cell segments. Extracellular D600 blocked INa in a 'voltage- and rate-dependent' manner as shown by the enhanced INa depression with a reduction of the 'resting' transmembrane polarization (Vmo) and stimulation interval (SI). D600 action was manifested as a voltage-dependent slowing down of the Na+ channels' recovery kinetics after a pulsed excitation, with greater recovery times during longer depolarized states, excited or non-excited. This phenomenon seems linked to the improved control of the intracellular environment normally influencing channel activity, and to the increased ratio of 'non-sarcolemmal' to 'sarcolemmal' cell membranes for this preparation.

Calcium Channel Blockers↗
PubMed2001

Sex and strain differences in the brush border and PAS-positive granules and giant bodies of the mouse renal S3 segment cells.

We recently demonstrated sexual dimorphism in the S3 segment of the ICR mouse kidney, as differences in periodic acid Schiff (PAS) staining on the brush border and the number and size of PAS-positive granules. However, whether these sex dependent features in the S3 segment of the mouse kidney occur only in the ICR strain or are a general feature also observed in other strains is unclear. In the present study, we examined the renal S3 segment of the ICR, BALB/c, C57BL/6, C3H/He and DBA/2 mice strains, which are commonly used in laboratory experiments. PAS staining of the brush border in females of all strains was more intense than that of males, and PAS-positive granules were detected in all females. In male groups, PAS-positive granules were detected in the DBA/2 strain only, but their number was very few. In addition, PAS-positive giant bodies, larger than the nuclear size, were detected in females except those of the C57BL/6 strain. Histometrical investigation demonstrated apparent strain differences in a number of PAS-positive granules and PAS-positive giant bodies. The ultrastructural and cytochemical investigations suggest that the PAS-positive granules and PAS-positive giant bodies were multilamellar lysosomes. We propose that the present findings are significant for comparative morphology in laboratory animal science.

Animals↗
PubMed2005

A method based on multispectral imaging technique for white blood cell segmentation.

Aiming at the problem of image analysis of White Blood Cells in bone marrow microscopic images, multispectral imaging techniques with spectral calibration method was proposed to acquire device-independent images, which is almost impossible in conventional color imaging method. For image segmentation, Support Vector Machine (SVM) was applied directly to the spectrum of each pixel, and using sequential minimal optimization (SMO) algorithm for feature selection to reduce the time of training SVM classifier. Mass of experiments showed that the method is robust, effective and insensitive to smear staining and illumination condition.

Algorithms↗
PubMed2005

Cell segmentation, tracking, and mitosis detection using temporal context.

The Large Scale Digital Cell Analysis System (LSDCAS) developed at the University of Iowa provides capabilities for extended-time live cell image acquisition. This paper presents a new approach to quantitative analysis of live cell image data. By using time as an extra dimension, level set methods are employed to determine cell trajectories from 2D + time data sets. When identifying the cell trajectories, cell cluster separation and mitotic cell detection steps are performed. Each of the trajectories corresponds to the motion pattern of an individual cell in the data set. At each time frame, number of cells, cell locations, cell borders, cell areas, and cell states are determined and recorded. The proposed method can help solving cell analysis problems of general importance including cell pedigree analysis and cell tracking. The developed method was tested on cancer cell image sequences and its performance compared with manually-defined ground truth. The similarity Kappa Index is 0.84 for segmentation area and the signed border positioning segmentation error is 1.6 +/- 2.1 microm.

Algorithms↗
PubMed1975

[Neuronal organization of the large-cell segment of the cat's red nucleus].

When studying the neuronal organization of the large-cell part of the red nucleus in cats by the Golgi and Golgi-Kopsch methods three types of neurons have been revealed: large (50-90 mu), medium-sized (20-50 mu) and small cells (8-20 mu). long axon and short-axon neurons were found as well as long-dendrite cells with few thorns (the length of the dendrites form 600-900 mu) and short-dendrite cells (up to 400 mu). On basis ofanalysis of neuronal groups found in the large-cell part of the red nucleus of the cat a neuronal map of this part of the central nervous sytem is composed.

Animals↗
PubMed1990

Segmental cell kinetics of the human anagen hair: a DNA-flow cytometric analysis.

The cell kinetics of anagen scalp hair taken by punch biopsies from 70 healthy male volunteers were determined at nine different defined bulbar and follicular hair segments using microdissection and DNA-flow cytometry. The highest mean proliferative activity (S-phase) was measured within the lowermost bulbar segment (14.0%), but decreased to 7.6% at Auber's segment and to 5.9% at the follicle isthmus. Notably, the S-phase data of the upper follicular segments (subdermal 2.4%, infundibular 2.4%) were found to be similar to those of the epidermis (2.5%). This study supporting and supplementing former autoradiographic investigations on human hair matrix epithelium clearly demonstrates the main proliferative activity of the anagen hair follicle being localized in the bulbar segments below Auber's level. Moreover, the method described is well suited for studying the effects of agents influencing cell growth (e.g., hormones or drugs) on the cell kinetics of different anagen hair compartments.

Adult↗
PubMed2001

Early development of amphioxus nervous system with special reference to segmental cell organization and putative sensory cell precursors: a study based on the expression of pan-neuronal marker gene Hu/elav.

The development of the nervous system of amphioxus was investigated at the cellular level based on the expression of the pan-neuronal marker gene Hu/elav. In situ hybridization analysis showed that an amphioxus Hu/elav homolog (AmphiHu/Hel) was expressed in individual cells within the neural plate, but the cells exhibited no obvious arrangements in early embryos without distinct somites. However, in neurulae with somites, AmphiHu/Hel-positive cells were clustered along the D-V axis in close register with the boundaries of somites, resulting in reiterated cell arrangements that became evident along the neuraxis. Furthermore, AmphiHu/Hel-positive cell clusters appeared one by one along with the development of underlying somites. Double-staining in situ hybridization analysis with the islet gene revealed that the cell clusters contain presumptive motoneurons. In addition, AmphiHu/Hel expression was also observed outside the CNS, probably in the epithelial ectoderm, suggesting that amphioxus has a large number of putative sensory cell precursors as early as the early neurula stage. Taking recent gene expression studies and anatomical studies into consideration, we discuss ontogenetic and phylogenetic features of the amphioxus nervous system.

Amino Acid Sequence↗