Light and electron microscopic characteristics of signet-ring adenocarcinoma cells in serous effusions and their distinction from mesothelial cells

Signet-ring adenocarcinoma cells in serous fluids have been classically described as possessing vacuolated cytoplasm and eccentrically placed, crescent-shaped nuclei. We studied serous fluids from six patients that contained signet-ring adenocarcinoma cells by light microscopy; one case was also studied by transmission electron microscopy. We found that the adenocarcinoma cells were more often present in a non-signet-ring configuration. The typical crescent-shaped nucleus was rarely displayed in smears and may be seen only in the cell-block preparation. Special stains (PAS, mucicarmine and Diff-Quick) showed globular cytoplasmic positivity in signet-ring adenocarcinoma cells but not in mesothelial cells. Significant characteristic electron microscopic findings in the signet-ring adenocarcinoma cells included (1) cytoplasmic lumens or invaginations or both, (2) cytoplasmic protrusions and (3) mucin granules of various sizes and densities. Singly or in combination, all of the above features were located on one side of the nucleus, which suggests that signet-ring adenocarcinoma cells retain some degree of cellular polarity.     

Micro-buffy coats of whole blood: a method for the electron microscopic study of mononuclear cells

A method for the electron microscopic study of human peripheral lymphocytes by which very small buffy coats are obtained through centrifugation of heparinized whole blood in glass or plastic microhematocrit tubes is presented. This method is time saving and efficient, yielding well preserved material and a comparatively large number of mononuclear cells (mainly lymphocytes) in each thin section.     

An improved method for electron microscopic observation of cerebrospinal fluid cells

Human cerebrospinal fluid (CSF) cells were entrapped between two bovine serum albumin cylinders linked by glutaraldehyde using microhematocrit tubes. The "sandwiched" specimen could be processed in further preparatory steps like tissue for routine electron microscopy. This rapid procedure resulted in adequate cell preservation for transmission electron microscopy without substantial loss of CSF cells.     

Legume Lectins: I. Immunological Cross-Reactions between the Enzymic Lectin from Mung Beans and other Well Characterized Legume Lectins

A number of well characterized legume lectins including the enzymic lectin from Vigna radiata were examined for immunological relatedness. The immunological cross-reactions observed indicate that most of the legume lectins, including Vigna lectin, are evolutionarily closely related proteins. The possibility that these proteins are homologs with enzymic functions is discussed.     

Experimental charge density from electron microscopic maps

The charge density (CD) distribution of an atom is the difference per unit volume between the positive charge of its nucleus and the distribution of the negative charges carried by the electrons that are associated with it. The CDs of the atoms in macromolecules are responsible for their electrostatic potential (ESP) distributions, which can now be visualized using cryo‐electron microscopy at high resolution. CD maps can be recovered from experimental ESP density maps using the negative Laplacian operation. CD maps are easier to interpret than ESP maps because they are less sensitive to long‐range electrostatic effects. An ESP‐to‐CD conversion involves multiplication of amplitudes of structure factors as Fourier transforms of these maps in reciprocal space by 1/d², where d is the resolution of reflections. In principle, it should be possible to determine the charges carried by the individual atoms in macromolecules by comparing experimental CD maps with experimental ESP maps.     

Light microscopic distinction of collagens in hepatic cirrhosis

Summary Pollen DNAse of Chlorophytum comosum was demonstrated cytochemically by coupling the breakdown of DNA (due to the endogenous DNAse) with acid phosphatase supplied to the reaction mixture. Precipitation of the free phosphate groups (from acid phosphatase reaction on the freed nucleotides) as lead phosphate results in a electron dense deposit, visible with the electron microscope. Enzyme activity using this technique was localized in vesicles along the intine (principally along the aperture region) and around the generative cell.     

Electron microscopic autoradiographic and electron microscopic immunohistochemical studies on the anti-HPO antibody-producing cells

The secondary immune responses in mouse popliteal lymph nodes to horseradish peroxidase (HPO) were studied by a combination of electron microscopic autoradiography and electron microscopic immunohistochemistry in order to clarify the relationship between antibody-producing and DNA-synthesizing capacities of the plasmacytic series. The anti-HPO antibody-containing cells, which increased in number 72 h after the secondary antigenic stimulation, were mainly immunoblasts and immature plasma cells. Immunoblasts containing anti-HPO antibody incorporated [³H]thymidine more actively than did immature plasma cells containing anti-HPO antibody. In 144 h after the secondary antigenic stimulation, antibody containing cells consisted mainly of mature plasma cells and immature plasma cells. Immature plasma cells containing the anti-HPO antibody incorporated a little [³H]thymidine, but mature plasma cells containing anti-HPO antibody did not incorporate any [³H]thymidine.     

Comparison of different methods for the purification of eosinophils from human peripheral blood

Eosinophils are often purified in discontinuous gradients. Since continuous gradients usually provide a greater recovery of more highly purified cells, the present investigation was undertaken to compare the purification of eosinophils from normal whole blood in continuous and discontinuous gradients of Percoll. Contrary to our expectations, recovery and purity of eosinophils obtained from the discontinuous gradients were comparable to or higher than those from the continuous gradients of Percoll that were tested with whole blood. The purity of the modal fractions of eosinophils from the discontinuous gradients was between 88 and greater than 99% of the nucleated cells and from the continuous gradients, 80 to 93% of the nucleated cells. We have compared continuous and discontinuous gradients with many different kinds of cells. This is the first time we have found continuous and discontinuous gradients equally effective. We speculate this finding is related to the fact that the band capacities are vastly overloaded in these gradients. In addition, we tested the rate of superoxide production by eosinophils from the same donors after their purification by two different methods in discontinuous gradients. Eosinophils purified from normal whole blood in gradients of Percoll by a modification of the method of Roberts and Gallin [1985) Blood 65, 433-440) had a higher rate of superoxide production after stimulation with phorbol myristate acetate than those purified from leukocyte-rich plasma in gradients of Metrizamide by the method of Vadas et al. [1979) J. Immunol. 122, 1228-1236).     

The blood cells of the Antarctic icefish Chaenocephalus aceratus Lönnberg: light and electron microscopic observations

Peripheral blood and haemopoietic tissues of spleen and kidney of the icefish, Chaenocephalus aceratus were examined using LM and EM techniques. The peripheral blood contained cellular elements from all the recognized cell lines usually seen in other teleost groups. Erythrocytes were very rare; when found, they were mature or senile and fragile. Thrombocytes of two morphologies, several cell types considered to be part of the lymphoid series and monocytes/macrophages were present. Two distinctive types of granulocytes also were found; their morphologies and granulation were so different from teleost granulocytes hitherto described that their identification was impossible.     

The distinction of mesothelioma from adenocarcinoma in malignant effusions by electron microscopy

To determine the usefulness of the electron microscopic (EM) differential diagnosis between malignant mesothelioma and metastatic adenocarcinoma in cytologic specimens of serous fluids, we undertook a prospective study of 17 pleural and peritoneal effusions from 14 patients. In the nine effusions identified as malignant by routine cytologic examination, EM correctly diagnosed three mesotheliomas and six adenocarcinomas. EM resolved the differential diagnosis of mesothelioma versus adenocarcinoma in three cases in which routine cytologic examination could not. As with tissue specimens, EM cannot be used to diagnose the malignancy of cytologic specimens; it can, however, reliably identify the origin of cells diagnosed as malignant by routine cytologic examination. We conclude that, when EM is used to evaluate cytologically malignant effusions, it can accurately distinguish mesothelioma from adenocarcinoma. This technique will be diagnostically useful in selected cases and may be helpful in avoiding more invasive procedures as well as delays in diagnosis and therapy.     

An electron microscopic study of the cerebral blood vessels of the opossum

Summary Blood vessels of the opossum brain are paired, artery and vein, and end in a closed loop. Both anatomically and physiologically they are true end-arteries. The two limbs are enclosed within a single basement membrane and are separated from each other by an intercapillary cell thought to be analogous to the usual capillary pericytes. The similarity of this vascular arrangement to that in the rabbit placenta and in the medulla of the kidney is discussed in relation to the counter-current multiplier system.This work was supported in part by the Beaumont-May Institute of Neurology and by a grant, B-425, from the United States Public Health Service.Research Fellow of the National Multiple Sclerosis Society.     

An electron microscopic study of bacteriophages from marine waters

The morphology of 75 bacteriophage strains isolated from water samples collected in the North Sea or in the northern Atlantic was studied by electron microscopy. Only tailed phages were observed (bradley groups A, B, and C). According to structural similarities, the strains are ascribed to 12 groups, 5 of which comprise types of marine phages not reported before. Four of these 5 groups include phage types that have not been detected from any other source. Among the phages isolated from northern Atlantic water a high incidence was observed of strains the particles of which have long appendages. Certain types of the northern Atlantic phages investigated were derived only from samples collected either east or west of the Azores. This finding agrees with former observations pointing to the existence of different populations of closely related bacteria east and west, respectively, of the northern Mid-Atlantic Ridge.     

A simple technique for supporting single cells in electron microscopic immunocytochemistry and embedding

Summary Cell suspensions of rat anterior pituitaries were filtered with a polycarbonate filter (pore size 3 m) and fixed on the filter. After fixation the cells were adherent to the filter and immunocytochemical staining could be accomplished by simply dipping the filter into the different incubation media. The cells could be dehydrated and embedded in Epon 812 on the filter. After polymerization the embedded filter was sawn into small blocks and the cell layer was sectioned tangentially on an ultramicrotome. This method also seems to be applicable to other histochemical studies on single cells.Supported by Deutsche Forschungsgemeinschaft, SFB 87/B2