Caveats in the use of archival cell material for DNA ploidy analysis by image cytometry

Monolayer preparation from paraffin-embedded tissue from archival biopsy specimens older than 10 years was shown in this study to be more difficult to deal with than recent biopsies. We have studied the disseminative effect of several enzymes on archival biopsies from laryngeal epithelium, as well as mechanical dissemination. Thirty minutes incubation in protease 0.5% in 37 degrees C without syringing provided the best cell yield. Hydrolysis and Schiff staining conditions were also studied. Cell loss was calculated by stereological methods and found to be high in most cases. Cell loss during various steps in monolayer production was examined and we found no proof of selective cell loss. Large variations in Feulgen-Schiff staining intensities were observed, especially in biopsy specimens older than 10 years. The use of reliable internal (intrinsic) control cells is advocated since interspecimen variations in the diploid integrated optical density (IOD) can be expected. Although DNA measurements on archival biopsy material should be treated with caution, we demonstrate that meticulous studies of the preparation procedures will make it possible to obtain reliable histograms from old, archival biopsies.

Chemical composition and morphology of welding fume particles and grinding dusts

Elemental composition and morphology of pure manual metal arc (MMA) welding fumes, pure grinding dust, and combined fume/dust air samples were collected and determined separately under semilaboratory conditions. The base material was stainless steel. The purpose of the present study was to create a "synthetic" work situation under semilaboratory conditions by combining one grinding period and two MMA welding periods and comparing these results with results during welding in a workshop. The duty cycles of pure welding and of pure grinding were also observed. A comparison was also made between metal inert gas (MIG) and MMA welding on stainless steel as well as a nickel-rich alloy under regular conditions. The amount of collected material was determined by weighing the membrane filters before and after exposure, and the element contents were determined by atomic spectroscopy. Other transmission electron microscopy (TEM) filters were used for TEM and computer-image analysis, in which the amount of collected material and its morphological characteristics were observed. The arcing time and the consumption of filler material were estimated for different kinds of electrodes. Chemical analysis showed that the contents of manganese and total chromium were lower in grinding dust than in welding fumes. The contents of hexavalent chromium, Cr(VI), in grinding dust were undetectable. Samples collected in welding shops where concomitant grinding was performed contained about 30% less Cr(VI) than those collected under laboratory conditions during welding only. The sizes and shapes of the particles depend on the welding process and distance of collection from the plume of the fume. To compare laboratory experiments with regular welding situations, the experiment must resemble industrial welding.(ABSTRACT TRUNCATED AT 250 WORDS)

Low-grade cribriform ductal carcinoma in situ of the breast. Fine needle aspiration cytology in three cases

This paper presents the cytologic features of fine needle aspiration biopsy specimens from three cases of ductal carcinoma in situ characterized by small and uniform tumor cells growing in a predominantly cribriform pattern without comedo necrosis (low-grade cribriform ductal carcinoma in situ). On cytology, most of the tumor cells were clustered in three-dimensional ductal structures. Occasionally in the clusters the tumor cells were seen bordering central lumina, quite similar to the architecture in histology. A few single tumor cells and no myoepithelium were seen. The background was clear or slightly hemorrhagic, without necrosis. The tumor cells were uniform and had a cylindroid shape, with round or oval nuclei. Morphometrically the mean largest nuclear diameter was 1.5-1.6 times that of a red blood cell. The chromatin was finely granular, with a minute nucleolus and slight condensation along the nuclear membrane. In cut sections all three tumors showed strong immunoreactivity for neuron-specific enolase. Unless the cribriform growth pattern is recognized in the smear, the cytologic diagnosis of this entity is difficult.

Chromosome 13 alterations in osteosarcoma cell lines derived from a patient with previous retinoblastoma

Various sublines of cells established from an osteosarcoma that developed in a patient (O.H.) with previous bilateral retinoblastoma were examined for different restriction fragment-length polymorphisms of chromosome 13q, as well as for rearrangements of the retinoblastoma gene using a cDNA probe. The independently established sublines were used to help separate primary and secondary events taking place in tumorigenesis of the osteosarcoma of this patient. Information from the present DNA analysis, taken together with data from cytogenetic and enzymatic studies on chromosome 13 in the cell lines, revealed both common and distinct genetic changes on chromosome 13q. The common changes may indicate the nature of the first and second mutational events in the development of the osteosarcoma. The first, constitutional cancer predisposing mutation seemed to be a base mutation or a small deletion/insertion, and the second event involved a deletion of a larger part of the long arm of chromosome 13. The distinct genetic changes included other deletion and duplication events of chromosome 13q. The existence of multiple sublines with different genetic constitutions provides improved possibilities for gaining insight into the nature of the genetic lesions leading to tumor formation, as these may reflect the clonal variation present in the primary tumor. We also demonstrate the difficulty of inferring from single tumor cell isolates to properties of the primary tumor.

Localization of potent photosensitizers in human tumor LOX by means of laser scanning microscopy

By means of laser scanning fluorescence microscopy the intratumoral localization patterns of several photosensitizers in LOX tumors in nude mice were studied. Lipophilic dyes such as TPPS1 (tetraphenylporphine monosulfonate), TPPS2a (tetraphenylporphine disulfonates with the sulfonate groups on adjacent rings), AlPCS1 (aluminium phthalocyanine monosulfonate) and AlPCS2 (aluminium phthalocyanine disulfonates) localized mainly in tumor cells. The fluorescence intensity of these dyes increased from 4 h to 48 h postinjection and the fluorescence was still observable 120 h postinjection. The more hydrophilic dyes such as TPPS3 (tetraphenylporphine trisulfonates), TPPS4 (tetraphenylporphine tetrasulfonates), and AlPCS4 (aluminium phthalocyanine tetrasulfonates) localized mainly extracellularly in the tumorous stroma. The fluorescence intensity of these dyes decreased from 4 h to 48 h postinjection. 120 h postinjection no significant fluorescence of these dyes could be seen in the tumors. P-II (Photofrin II), 3-THPP [tetra(3-hydroxyphenyl)porphine], TPPS2o (tetraphenylporphine disulfonates with the sulfonate groups on opposite rings) and AlPCS3 (aluminum phthalocyanine trisulfonates) had a combined localization pattern, i.e. a strongly cytoplasmic membrane-localizing pattern and a weakly intracellular distribution pattern, although some fluorescence could be seen in the tumorous stroma. The data are discussed in relation to what is known about the in vivo photosensitizing efficiency of some of the dyes.

Localization of potent photosensitizers in human tumor LOX by means of laser scanning microscopy

By means of laser scanning fluorescence microscopy the intratumoral localization patterns of several photosensitizers in LOX tumors in nude mice were studied. Lipophilic dyes such as P-II (Photofrin II), 3-THPP tetra(3-hydroxyphenyl)porphin, TPPS1 (tetraphenylporphine monosulfonate), TPPS2a (tetraphenylporphine disulfonates with the sulfonate groups on adjacent rings), A1PCS1 (aluminium phthalocyanine monosulfonate) and A1PCS2 (aluminium phthalocyanine disulfonates) localized mainly in tumor cells. The fluorescence intensity of these dyes increased from 4 h to 48 h post-injection and the fluorescence was still observable 120 h post-injection. The more hydrophilic dyes such as TPPS2o (tetraphenylporphine disulfonates with the sulfonates groups on opposite rings), TPPS3 (tetraphenylporphine trisulfoantes), TPPS4 (tetraphenylporphine tetrasulfonates), A1PCS3 (aluminium phthalocyanine trisulfonates) and A1PCS4 (aluminium phthalocyanine tetrasulfonates) localized mainly extracellularly in the tumorous stroma. The fluorescence intensity of these dyes decreased from 4 h to 48 h post-injection. 120 h post-injection no significant fluorescence of these dyes could be seen in the tumors. The data are discussed in relation to what is known about the in vivo photosensitizing efficiency of some of the dyes.

The selection of thin epithelial layers: a method for single cell preparations of very small biopsies from the vocal cords

Precancerous lesions in biopsy material very rarely contain more than a thin epithelial layer of atypical cells overlaying stromal parts. This makes it difficult to produce cell monolayers for cytometry from archival material and necessitates a technique which excludes the stromal areas. We have developed a method by which it is possible to separate epithelial layers from the stroma with a thickness of 100-200 microns, using fluorescence microscopy and dissection under a stereo microscope. The stroma can be used as an internal reference in IOD measurements. Our method insures maximum control when dealing with very small lesions of interest (down to 0.02 mm2) that have to be separated from the rest of the biopsy. The method has been applied to normal, dysplastic and cancerous epithelial parts of biopsies of the vocal chords.

Three-dimensional structure of the surface layer of Wolinella recta

The three-dimensional structure of the crystalline surface layer (S-layer) of Wolinella recta ATCC 33238T, a gram-negative, anaerobic periodontopathogen, was determined to 3.8 nm resolution by electron microscopy and digital image processing. The S-layer protein is closely associated with the outer bacterial membrane, and shows p6 symmetry with lattice spacing and thickness of 21 nm and 15 nm, respectively. The funnel-shaped subunits consist of 6 heavy domains located round a common base at the sixfold axis, and communicate with the adjacent subunits through a lighter domain at the threefold axis (M6C3 arrangement).

Image analysis of endodontic radiographs: digital subtraction and quantitative densitometry

In this study computerized image analysis procedures were applied to endodontic radiographs. Kontron IBAS 2000 is a commercially available image analysis system with processing routines applicable to radiograph digitizing and transformations. The system was evaluated for: its ability to harmonize blackening and contrast in endodontic radiographs; its ability to compensate for angulation distortion of sequential exposures of individual teeth; its potential for application of digital subtraction methods; and its use in automated gray-level analyses of diseased and healthy bone areas in endodontic radiographs. The Kontron IBAS 2000 system proved suitable for all applications. However, the specificity of the subtraction procedure was limited by some inherent problems in the harmonization of blackening and in the subtraction process itself. On the other hand, automated gray level measurements proved to be a robust method for unbiased and quantitative assessment of healing of apical periodontitis.

Characterization of the morphological properties of welding fume particles by transmission electron microscopy and digital image analysis

The morphological characteristics of welding fume particles have been determined using transmission electron microscopy (TEM) and automatic image analysis (AIA). Two personal samples and one background sample were collected using a new, easy to handle sampling method, during tungsten inert gas (TIG) and manual metal arc (MMA) welding on Inconel in the same shop. The collection method gave samples which were suitable for TEM and AIA. Electron micrographs were taken in a transmission electron microscope and further analyzed using an image analysis unit. Aggregates composed of many individual particles were analyzed both for the parameters of the aggregate and for the parameters of the individual particles by using an algorithm based on a grain boundary reconstruction technique. The morphological parameters allowed the welding fume's particulate matter to be divided into three types - here called small, medium, and large - with a somewhat unclear distinction between medium and large. Medium and large particles occur either as individual particles or as clusters of approximately spherical particles with average diameters of 0.07 and 0.15 microm, respectively. Small particles occur almost exclusively as long chains or lace-like structures of aggregates of particles, often in the range of 5-10 microm. The aggregates have an average projected area of 2.6 x 10-3 microm2 and are composed of several hundred individual particles.

Structures of two different surface layers found in six Bacteroides strains

The structures of crystalline layers from six Bacteroides strains were studied by electron microscopy. Two different hexagonal crystalline surface layers were found, one with a unit cell spacing of 21.5 nm and another with a spacing of 7.7 nm. A three-dimensional structure of the 21.5-nm layer and a two-dimensional projection of the 7.7-nm layer were determined to 3.0- and 3.8-nm resolution, respectively, by computerized image processing of electron micrographs. Both of these two crystalline layers were found in all six strains studied: B. pentosaceus NP333T and WPH61, B. capillus ATCC 33690T and ATCC 33691, and B. buccae ATCC 33574T and ES57. This further supports the identity of B. pentosaceus, B. capillus, and B. buccae as suggested by M. Haapasalo, K. Lounatmaa, H. Ranta, H. Shah, and K. Ranta (Int. J. Syst. Bacteriol. 35:65-72, 1985). The surface layer with 21.5-nm spacing is an intricate network with two classes of pores through the layer.