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At least 307 records · Page 17Linked to original sources
PubMed1996

Investigation of carcinoma in situ cells of testis by quantification of argyrophilic nucleolar organizer region associated proteins (AgNORs).

The silver staining which specifically stains argyrophilic proteins (AgNORs) in interphase nuclei was applied to paraffin sections of 24 testicular specimens with carcinoma in situ (CIS). AgNOR area per nucleus was quantified by a computerized image analyser. Significant quantitative differences were found between CIS, Sertoli cells, and spermatogonia (P = 0.0001), with median values of 10.3, 2.8, and 1.4 microns2 in the three cell types, respectively. A Sertoli cell index (SCI), defined as the ratio between AgNORs in CIS or spermatogonia and Sertoli cells, was shown to be significant in the differential diagnosis of CIS cells from spermatogonia when 1.0 was used as the cut-off value (CIS > 1; spermatogonia < 1). Furthermore, CIS associated with non-seminoma was found to have a significantly higher level of AgNORs than CIS associated with pure seminoma (P < 0.01), indicating that subclonal variation in transformation potential might be present within morphologically identical CIS of the testis. It remains to be seen whether quantification of AgNORs in isolated CIS could be used to predict transformation of CIS into seminoma or non-seminoma.

Carcinoma in Situ↗
PubMed1997

Ultramicrotomy of powder material for TEM/STEM study.

This paper summarizes methods conventionally used to prepare thin foil samples of powder materials for transmission electron microscopy (TEM) and introduces another variant, ultramicrotomy, for the preparation of TEM samples of industrial dust powder. The choice of ultramicrotoming in the present work was based on two features of this technique: (1) it can produce thin-sectioned specimens with a uniform thickness; (2) it can retain the original elemental distribution in phases of the sample during sectioning. Dust powder preparation and the sectioning procedure are described in this paper. The results of the method are illustrated by examples of TEM/STEM micrographs of industrial dust.

Microscopy, Electron↗
PubMed1998

Ultramicrotomy on fretting wear debris.

A TEM-sample preparation method for small amounts of fretting wear debris is presented. After embedding in a resin, the debris are ultramicrotomed to ultra-thin sections. In this way, valuable observation of nanocrystalline fretting wear debris originating from TiN-coatings could be rapidly obtained.

Alloys↗
PubMed1998

Computer simulation as a tool in evaluating intracellular spatial arrangement of an organelle using random section data.

A random profile of a cell gives a highly biased presentation of the location of various organelles within an intracellular space. The technique combining mathematical modeling and computer simulation presented here is aimed to overcome this bias and interpret intracellular spatial arrangement of an organelle using two-dimensional (2-D) observations from random sections. It allows to simulate random sectioning of a cell whose shape approximates to an ellipsoid of rotation, and to obtain the coordinates for the center of an organelle profile located within a cell profile. The pilot study was performed to investigate the influence of different three-dimensional (3-D) scattering patterns of an organelle on the coordinates of an organelle profile's center. Computer tests were carried out on a personal computer using the original software written in Pascal. It was ascertained that statistical properties of a sample of organelle profile's center coordinates allow for a quantitative estimation of some 3-D features, including the position of an organelle with respect to a cell center and specific characteristics of an organelle position (e.g., its fixity or randomness).

Cells↗
PubMed1996

Formation of interalveolar pores in the rat lung.

BACKGROUND: The aim of this morphological investigation was to obtain more information about the structural and cellular mechanisms of interalveolar pore formation in postnatal lung development. Assuming that alveolar pore formation is related to the general thinning of interalveolar walls observed in the postnatal period, we have focused our attention on the topographical relationship between epithelial cells and connective tissue in the septum. Thereby we tried to formulate a uniform concept of pore formation. METHODS: After fixation with glutaraldehyde and osmiumtetroxide, tissue blocks of rat lungs aged 44 days were embedded in Epon. Serial sections were obtained in order to analyse precisely pores and supposed sites of pore formation (type II cells and thin spots in transsections of interalveolar walls). RESULTS: We made the following observations: there are pores with or without type II cells in the neighbourhood, and "pre-pores" with either fully transseptal granular pneumocytes, or thin spots in the interalveolar wall consisting of one or two layers of type I cell epithelium or of type II and type I cells without intervening connective tissue. CONCLUSIONS: From these findings we deduce that there is a general principle of interalveolar pore formation which consists in the formation of transseptal interepithelial cell contacts (i.e., between cells of type II and type I or type I and type I), promoted by the thinning of interalveolar walls in the stage of microvascular maturation. Within the zone of contact the cells thin out and give way to form an interalveolar opening.

Animals↗
PubMed1997

External marker-based automatic congruencing: a new method of 3D reconstruction from serial sections.

BACKGROUND: Computer-based three-dimensional (3D) visualizations reconstructed from sectional images represent a valuable tool in biomedical research and medical diagnosis. Particularly with those imaging techniques that provide virtual sections, such as CT, MRI, and CLSM, 3D reconstructions have become routine. Reconstructions from physical sections, such as those used in histological preparations, have not experienced an equivalent breakthrough, due to inherent shortcomings in sectional preparation that impede automated image-processing and reconstruction. The increased use of molecular techniques in morphological research, however, generates an overwhelming amount of 3D molecular information, stored within series of physical sections. This valuable information can be fully appreciated and interpreted only through an adequate method of 3D visualization. METHODS AND RESULTS: In this paper we present a new method for a reliable and largely automated 3D reconstruction from physically sectioned material. The 'EMAC' concept (External Marker-based Automatic Congruencing) successfully approaches the three major obstacles to automated 3D reconstruction from serial physical sections: misalignment, distortion, and staining variation. It utilizes the objectivity of external markers for realignment of the sectional images and for geometric correction of distortion. A self-adapting dynamic thresholding technique compensates for artifactual staining variation and automatically selects the desired object contours. CONCLUSIONS: Implemented on a low-cost hardware platform, EMAC provides a fast and efficient tool that largely facilitates the use of computer-based 3D visualization for the analysis of complex structural, molecular, and genetic information in morphological research. Due to its conceptual versatility, EMAC can be easily adapted for a broad range of tasks, including all modern molecular-staining techniques, such as immunohistochemistry and in situ hybridization.

Animals↗
PubMed1997

Three-dimensional reconstruction of histological sections using modern product-design software.

BACKGROUND: Computer-based, three-dimensional reconstruction of histological sections is necessary for solving a diversity of questions in morphology and anatomy. Programming software for this purpose is difficult and time-consuming. Therefore, we tested if commercially available product-design software is useful for reconstructing anatomical virtual models. METHODS: We used Alias Wavefront Studio software on a Silicon Graphics workstation. Sections were projected with a newly developed microslide projector on a digitizing board and digitized interactively. Alternatively, pictures of sections were digitized on screen. The resulting set of contours was used as scaffold around which a surface was created manually. RESULTS: Repeated creation of the same object and subsequent measurements gave results that will be sufficiently reliable for many purposes. The visual presentation of objects satisfy highest demands. Little time is needed to reconstruct simple objects, and the time used for complex virtual models is acceptable. Manipulation of objects on screen is nearly in real time and rendering speed is high. CONCLUSIONS: Product-design software packages are a readily available and useful option for anatomists who want to do virtual reconstructions quickly without programming software themselves.

Animals↗
PubMed1998

Three-dimensional direction and interrelationship of prisms in cuspal and cervical enamel of dog tooth.

The three-dimensional architecture of enamel prisms was examined in cuspal enamel and compared with that in cervical enamel by light and electron microscopy as well as computer-assisted reconstruction using the developing enamel of several dog teeth. Dog tooth enamel consists of two groups of alternately arranged enamel prisms oriented in opposite sideward directions basically forming thick horizontal rings, partly branching off from the stem. Along a 8-10 enamel prism-wide group, the enamel prisms emerge in parallel tilting uniformly to the same sideward direction. In cervices, groups of enamel prisms are arranged nearly in parallel displaying a regular arrangement of prisms. Approaching the cusp of tooth, the groups of enamel prisms fuse to a concentric cusp-centered arrangement and the prisms exhibit no periodic arrangement as shown in the cervical enamel. It is suggested that the three-dimensional structure of enamel becomes complicated close to the cusp, contributing to the chewing stress of tooth.

Ameloblasts↗
PubMed1998

Increase in odontoclast nuclei number by cell fusion: a three-dimensional reconstruction of cell fusion of human odontoclasts.

Osteoclasts and odontoclasts are known to increase their nuclear number by fusion of mononuclear precursors. However, the pattern of fusion remains morphologically unclear. One lower right deciduous canine of an 8-year-old male was investigated. Tartrate-resistant acid phosphatase activity (TRAP) positive cells on the resorbing surface of the tooth were serially sectioned into 0.5 microm-thick semithin sections. The sections were photographed, and cells possessing a light microscopic brush border facing a resorptive lacuna were identified as odontoclasts. Fourteen odontoclasts appearing as a continuous figure of cellular membrane between cells on one section were three-dimensionally reconstructed using NIKON COSMOZONE 2SA. A criterion for fusion was established in this study, requiring that there must be two or more nucleated cells which contacted each other at one site only in the three-dimensional reconstruction. Among 14 reconstructed cells, 10 odontoclasts satisfied the criterion for fusion. The observations of the three-dimensional structures of these odontoclasts showed that mononuclear and multinucleated odontoclasts participated in fusion. Cell fusion occurred between resorbing odontoclasts and cells not forming lacunae, and between resorbing odontoclasts. A case of odontoclastic fusion among three cells was also observed. The results establish that fusion resulting in multinucleation occurred among various odontoclasts with different numbers of nuclei including mononuclear odontoclasts.

Cell Fusion↗
PubMed1996

Combination of lamin immunocytochemistry and in situ hybridization for the analysis of chromosome copy numbers in tumor cell areas with high nuclear density.

We describe the application of lamin immunocytochemistry (ICC) and single- or double-target fluorescence in situ hybridization (FISH) on 4 microm thick frozen tissue sections as a method to facilitate scoring of aberrant chromosome copy numbers in colonic tumors. Analysis of FISH signals in colon tissue sections is often hampered by overlap and truncation of epithelial nuclei, due to the density of the epithelial cells. Furthermore, on the basis of nuclear staining it is often difficult to determine whether or not nuclei are overlapping, or adjoining. Therefore, reliable evaluation of (F)ISH signals to screen for genomic changes was until now mainly restricted to isolated nuclei obtained from relatively thick tissue sections. In this study the applicability of lamin ICC, to stain the nuclear periphery and to distinguish individual nuclei, combined with the FISH procedure is explored to solve this problem for colon epithelium. For ICC we applied the alkaline phosphatase (APase)-Fast Red detection method, since the fluorescent precipitate of this reaction resists extensive proteolytic digestion as needed for efficient FISH on tissue sections. Chromosome copy numbers could easily be determined in 4 microm thick frozen tissue sections by combining lamin ICC and FISH. The ratio of the copy numbers of the chromosomes 7 and 17 could be determined in frozen tissue sections after combined lamin ICC and double-target FISH. It is concluded that the combination of lamin ICC and FISH improves chromosome copy number analysis and can be used to investigate genomic changes in different tumor compartments in thin frozen tissue sections.

Alkaline Phosphatase↗
PubMed1996

New method of nuclear grading of tissue sections by means of digital image analysis with prognostic significance for node-negative breast cancer patients.

To optimize treatment of the individual patient with node-negative breast cancer, objective, reproducible, and standardized prognostic criteria are required. A number of factors have been studied in recent years, but until now it has been possible to obtain information about the risk of recurrence only for some patients belonging to subgroups with special characteristics. We report the establishment of an image analysis method for nuclear grading as an attempt to solve this problem. In a retrospective analysis, we used routine hematoxylin and eosinstained paraffin sections from 54 node-negative patients with surgery between 1980 and 1985. Cell scenes of primary tumors were scanned in a light microscope in successive focus positions to obtain three-dimensional information. After automatic image segmentation, nuclear features were calculated as input for a first binary classification tree to differentiate between tumor and nontumor cells. Tumor nuclei from patients with or without relapse were defined as high-risk or low-risk nuclei, respectively, and were separated with a second tree. Feature values of the measured tumor nuclei from each patient were examined with this second tree to analyze whether the majority of nuclei for each patient were classified as high-risk or low-risk nuclei. Correct classification rates in the two binary cell classification trees were 88.0% and 83.8%, respectively. In the learning sample of our study, all patients with a relapse had the majority of nuclei in the high-risk group, most with more than 80%. Therefore, it seems to be possible to develop an image analytical risk profile system for nuclear grading to provide information on individual prognosis.

Algorithms↗
PubMed1996

DNA image cytometry on sections as compared with image cytometry on smears and flow cytometry in melanoma.

DNA measurements of 130 melanomas were carried out by flow cytometry (FCM) and image cytometry (ICM). ICM was applied to cytological preparations of fresh material (cICM) and to sections of formalin-fixed paraffin embedded tissue (sICM). The DNA ploidy, the DNA index of G0/G1 peaks (DI), and the proliferation index (PI) were used to compare all the methods. The following parameters reflecting malignancy were calculated only from ICM histograms: the 5c exceeding rate (5cER) and the malignancy grade (MG). In cases found to be DNA aneuploid by FCM, the PI values (FCM versus cICM) and the DIs (between all methods) showed a high correlation, and the concordance in relation to the DNA ploidy status was 96% (FCM versus cICM) and 94% (FCM versus sICM). However, we ascertained essential differences between FCM and ICM in melanomas classified as DNA diploid by FCM. The concordance in DNA ploidy was only 66% (FCM versus cICM) and 64% (FCM versus sICM). In contrast, cICM and sICM yielded similar results in most cases. With the exception of the near diploid range, ICM is superior to FCM in detecting DNA aneuploidy. In particular, DNA tetraploid stem lines can easily be overlooked by FCM. Therefore, DNA measurements of tumours judged to be DNA diploid by FCM must be verified by ICM. ICM on sections proved to be applicable and yielded reliable results provided that a suitable thickness was used, and the measuring of sectioned and overlapping nuclei was largely avoided by careful focusing in either direction.

Aneuploidy↗
PubMed1997

Application of automatic thresholding in image analysis scoring of cells in human solid tumors labeled for proliferation markers.

We previously reported an image analysis program that uses four investigator-defined parameters including two thresholds, i.e., gray-level threshold (GLT) and hue threshold (HT), to determine the number of cells (TC) and the proliferating cell nuclear antigen (PCNA) or bromodeoxyuridine (BrdUrd) labeling indices (LI) in human solid tumors. The present study investigated if the accuracy and reproducibility of image analysis results can be improved by using computer-defined GLT and HT. Three investigators evaluated 142 images on 3 days, using visual analysis and four image analysis routines, which used different combinations of computer- and investigator-selected GLT and HT. The data show that image analysis using computer-selected GLT and HT yielded (i) LI of PCNA and BrdUrd that were indistinguishable from visual analysis, (ii) equal (BrdUrd LI) or better (TC and PCNA LI) inter-day reproducibility relative to visual analysis results, and (iii) results that were equally (TC) or more accurate (LI of PCNA and BrdUrd) with higher inter-day reproducibility (TC and LI of PCNA and BrdUrd) than image analysis obtained using investigator-defined thresholds. We conclude that the use of computer-defined GLT and HT improved the accuracy and reproducibility of image analysis results.

Analysis of Variance↗
PubMed1998

Differentiation of low-grade non-Hodgkin's lymphomas using paraffin sections by image processing.

In a previous study, we were able to demonstrate that the differentiation of low-grade non-Hodgkin's lymphomas (NHLs) using digital image analysis of touch imprints obtained from native tumor tissue is feasible. The availability of touch imprints in routine diagnostics, however, is restricted. Therefore, we extended our studies toward paraffin sections being used as routine material for histological diagnoses. To identify five types of NHL classified according to the Revised European American Lymphoma classification, paraffin sections (n=53) of NHL and 9 reactive lymphoid tissues (RLTs) were scanned with a color-video-based microscope system and analyzed by digital image processing. A reliable division between benign and neoplastic lymphoproliferations was achieved. We were able to identify 78% of RLTs as benign and 94% of NHLs as neoplastic. The average probability of correct identification into the six subgroups was 66%. In detail, 78% of RLTs, 50% of chronic lymphocytic lymphomas and MALT-type lymphomas, 72% of mantle cell lymphomas, and 67% of follicle center cell lymphoma were classified correctly. Although the method of subclassifying or identifying NHLs on the basis of a computer-mediated assay is still not usable in daily practice, we show that a reliable differentiation between reactive and neoplastic lymphoproliferative lesions can be achieved by analysis of paraffin sections with high-resolution image analysis and that it is possible to define nuclear structures by identifying subtypes of NHL.

Diagnosis, Differential↗
PubMed1998

Role of touch imprint and core biopsy for detection of tumor metastases in bone marrow.

A total number of 248 bone marrow trephine biopsies were reviewed and 21 paired biopsy and touch imprints were identified to estimate the role of these two diagnostic methods for detection of tumor metastases from nonhematologic malignancies in the bone marrow. The study period ran between January 1, 1993, and June 1, 1996. Eight histology sections and eight touch imprints were prepared from every case and were reviewed by two pathologists independently. In 20 cases, tumor cells were present without a doubt both on cytologic and histologic preparations. In one touch imprint, single cells were suspicious for malignancy, and the final pathology report was prepared after examination of the histologic sections. There was no positive biopsy in which the imprint was negative for tumor cells, and no positive touch imprint in which the biopsy was negative for such cells. The results from our study show that every one of these approaches has advantages and disadvantages and that they have a complementary role for identification of solid malignancies in the bone marrow.

Bone Marrow Neoplasms↗
PubMed1998

Diagnosing Helicobacter pylori by imprint cytology: can the same biopsy specimen be used for histology?

Imprint cytology of the gastric mucosa has been found to be very simple, inexpensive, and rapid for diagnosing Helicobacter pylori infection. However, there is a fear that preparing imprint smears may damage the biopsy specimen for subsequent histologic examination. This study was planned to investigate whether this damage happens. Four antral biopsy specimens were obtained from each of the 100 patients undergoing upper gastrointestinal endoscopy. Imprint smears were made from two biopsy specimens, which were then fixed in 10% formal saline and sent for histologic study. The third and fourth biopsy specimens were directed fixed in 10% formal saline for histologic examination. Two pathologists examined the imprint smears. Agreement between the two observers was observed in 97% of cases. Beyond-chance agreement was good with a kappa index of 0.90. H. pylori organisms were seen in 82% of biopsy specimens from which imprint smears were prepared and in the same percentage of biopsy specimens that were processed directly. The pathologists could not identify the histologic sections form which imprints were made. It is concluded that imprint cytology is an excellent method of diagnosing H. pylori infection and that preparing imprint smears does not alter the quality of the tissue. The same biopsy specimen can be used for histologic studies.

Cytodiagnosis↗