The problematic interpretation of foamy cells in breast fine needle aspirates. A report of two cases

BACKGROUND: Lipid-rich carcinoma and primary malignant fibrous histiocytoma (MFH) of the breast are rare tumors. Cytologically the presence of cells with foamy cytoplasm can cause diagnostic difficulties in both tumors. CASES: Fine needle aspiration was performed on two females with breast masses. The lipid-rich carcinoma showed cells with fine, variably sized vacuoles in the cytoplasm. The MFH smears showed large, histiocytelike cells with foamy cytoplasm, both mononucleated and multinucleated. CONCLUSION: When presented with cytologic smears showing foamy cells, in addition to the nature of the nucleus one must pay attention to the size and character of the cytoplasmic vacuoles to differentiate between sarcoma versus carcinoma.     

Stability of n-3 fatty acids in human fat tissue aspirates during storage

Six cases of atypical and malignant meningioma studied by intraoperative crush preparations are reported. Four atypical meningiomas were characterized by large cohesive and dyshesive cell clusters showing slightly pleomorphic nuclei and scant cytoplasm. The papillary meningioma yielded dyshesive groups of pleomorphic cells with variable and well-defined cytoplasm. The malignant meningioma, hemangiopericytic type, showed dyshesive cells with scant, ill-defined cytoplasm and spindle-shaped or vesicular nuclei.     

Nuclear localization of the interferon-inducible protein kinase PKR in human cells and transfected mouse cells

The levels and subcellular distribution of the interferon-inducible double-stranded RNA-dependent protein kinase PKR have been measured in human Daudi cells and stably transfected mouse NIH 3T3 cells expressing the human protein kinase. Immunofluorescence of intact cells and quantitative immunoblotting of cell extracts indicate that PKR occurs in both the cytoplasm and the cell nucleus, with staining specifically in the nucleolus. The ratio of cytoplasmic to nuclear PKR is approximately 5:1 in control cells; in response to interferon treatment the protein kinase is induced severalfold in the cytoplasm whereas the level in the nucleus does not increase significantly. Analysis of individual transfected cells by confocal microscopy reveals a pattern of distribution of PKR similar to that in Daudi cells, with immunostaining of cytoplasm and nucleoli. Similar results are observed whether cells expressing wild-type PKR or a catalytically inactive mutant form of the kinase are analyzed, but untransfected 3T3 cells are not stained by the antibody used. Two-dimensional isoelectric focusing analysis of PKR in whole cell extracts reveals the presence of multiple forms with different pI values whereas similar analysis of the nuclear fraction indicates only one predominant species with a relatively basic pI. These results suggest that PKR may have a role in the cell nucleus as well as the cytoplasm and that the subcellular distribution of the protein kinase may be related to post-translational modifications.     

The influence of Chernobyl nuclear power station disaster on the erythropoietic cells in the microenvironment of the liver

Erythropoesis activation, realizing by microenvironmental cells, was noted in hepar of the tailless amphibians R. Lessonae and R. Ridibunda, living in the Chernobyl AES alienation zone. Destructive changes, and the ribosome-protein complexes, fibrillar structures synthesis intensification was revealed in hepatocytes. Ribosome-protein complexes and fibrillar-granular material of hepatocytes enter the blood stream, where they incorporate into the erythroblasts cytoplasm. Focal hyperplasia and macrophages hypertrophy were revealed. Macrophages, transporting the hepatocytes cytoplasm components into erythroblasts and supplementing them with their cytoplasm synthesis products, take an active part in supply of differentiating red blood cells with different materials.     

Highways for protein delivery to the mitochondria

Messenger RNA (mRNA) localisation is one of the prime mechanisms to ensure protein localisation in the cytoplasm of polarised embryonic cells, and has been well-studied in the development of Xenopus and Drosophila embryos. But what of other cells? Here, we discuss whether the directed transport of mRNA out of the nucleus, following cytoplasmic highways to a specified organelle in the cytoplasm, might also contribute to the exquisite fidelity of protein targeting observed in all eukaryotic cells.     

Mechanical basis of cell shape: investigations with the scanning acoustic microscope

The shape of cells during interphase in sparse cultures often resembles that of fried eggs. XTH-2 cells, which have been derived from tadpole heart endothelia, provide a typical example of this type of shape. To understand the physical basis of this shape, the cytoskeleton of these cells has been investigated in detail. Subcellular elasticity data have been achieved by scanning acoustic microscopy (SAM). Their changes were observed during treatment of the cells with microtubule-disrupting agents (colcemid and low temperature), and shape generation in giant cells produced by electro-fusion was observed with SAM, revealing the role of the nucleus as a force centering organelle. From these observations combined with well-documented observations on cellular dynamics described in the literature, a model is developed explaining the fried-egg shape of cells by means of interacting forces and fluxes (cortical flow, bulk flow of cytoplasm, microtubule-mediated transport of cytoplasm) of cytoplasm. The model also allows the comprehension of the increase of tension in cells treated with colcemid.     

Nucleotide sequence of 5''-upstream region and expression of a silkworm gene encoding a new member of the attacin family

The morphometric and morphological changes in the mesothelial cell population were studied in rabbits in peritoneal dialysis with lactate and bicarbonate buffer solution. During dialysis the mesothelial population underwent radical changes in morphology and morphometric analysis showed a significant increase in cell size. Light microscope examination showed two types of changes: hyperplasia of the mesothelial cell with diameters of up to 80 microns, nucleus proportional to the cytoplasm, a large nucleole giving an owl's eye appearance and cytoplasm rich in granular material. The second change was multiple nuclei and arrest of cell division. Nuclear division occurred, but no separation of the cytoplasm. The cells became larger than 200 microns, packed with nuclei and relatively little cytoplasm. Electron microscopy confirmed that the hyperplastic cells had perfect structure whereas the polynucleate cells contained vacuoles and little cytoplasmic reticulum. Immunohistochemistry using monoclonal antibodies SK2-27 and SK 60-61 specific to cytokeratins 14, 16, 17 and 8, 18, respectively, identified the cells as mesothelial. The changes were related to the glucose content of the peritoneal dialysis solution. Glucose is therefore the bioincompatible agent that modifies the mesothelium during peritoneal dialysis, causing it to become hyperplastic or blocking replication.     

Nerve and glial cells of the sympathetic ganglia of mice of different ages. I. Interferometric and electron microscopic study of the perikarya of nerve cells of normally developing animals

The perikarya of sympathetic nerve cells from stellate ganglia of 1.3 and 8 month old mice were studied by interference and electron microscopy. Both the number of nerve cells and the dry weight of their perikarya are the same in animals of different ages. According to the ultrastructure, all the sympathetic neurons of adult mice belong to one of the two main groups. The "dark" cells are characterized by a higher electron opacity of nucleo and cytoplasm, the convoluted nuclear envelope and endoplasmic reticulum being randomly distributed throughout the cytoplasm. In the "light" cells from ganglia of I and 3 month old mice, the granular endoplasmic reticulum forms a kind of a belt around the nucleus and is situated in the middle area of the cytoplasm. The majority of nerve cells from the ganglia of 8 month old mice, in addition to the increase in pigment granule contents, are characterized by a lower frequency of the rough endoplasmic reticulum without changes in the number of polysomes not attached to membranes.     

Nuclear RNA in the mouse spleen at the peak of primary immune response

Results of studies on the synthesis of different fractions of cytoplasmic RNA in the spleens of immunized mice at the peak of primary immune response are reported. RNA was extracted by the phenol-detergent procedure from the cytoplasm of spleen cells of mice immunized with sheep red blood cells. The kinetics of labeling in vivo with 32P-orthophosphate indicate an accelerated biosynthesis and transport from nucleus to cytoplasm of 28S, 18S and 4S fractions of RNA.     

The pathology of americium 241

The morphology of satellite cells was investigated in skeletal muscle from mice of various ages between 7 days and 50 weeks. Satellite cells of very young muscle had abundant cytoplasm which was rich in organelles. Free ribosomes were abundant and usually arranged into polysomes of 5-6 units. Cisternae of rough endoplasmic reticulum were heavily studded with ribosomes and occupied the polar regions of the cytoplasm. Marked dilations of the cisternae, filled with an amorphous electron-lucent material, were a frequent and characteristic feature of satellite cells of very young muscle. The cytoplasm of young cells also contained a well developed Golgi apparatus as well as numerous mitochondria, microfilaments and microtubules. With increasing age there was a rapid reduction in organelles both qualitatively and quantitatively. For rxample, as the number of ribosomes decreased, their organization into polysomes was lost. The rough endoplasmic reticulum was present in cells of older muscle merely as small isolated profiles that lacked dilations. These and other features demonstrated during this study are consistent with the concept that satellite cells are metabolically very active in young muscle but rapidly become quiescent as the animal grows older.     

Intracellular redistribution of truncated La protein produced by poliovirus 3Cpro-mediated cleavage

The La autoantigen (also known as SS-B), a cellular RNA binding protein, may shuttle between the nucleus and cytoplasm, but it is mainly located in the nucleus. La protein is redistributed to the cytoplasm after poliovirus infection. An in vitro translation study demonstrated that La protein stimulated the internal initiation of poliovirus translation. In the present study, a part of the La protein was shown to be cleaved in poliovirus-infected HeLa cells, and this cleavage appeared to be mediated by poliovirus-specific protease 3C (3Cpro). Truncated La protein (dl-La) was produced in vitro from recombinant La protein by cleavage with purified 3Cpro at only one Gln358-Gly359 peptide bond in the 408-amino-acid (aa) sequence of La protein. The dl-La expressed in L cells was detected in the cytoplasm. However, green fluorescence protein linked to the C-terminal 50-aa sequence of La protein was localized in the nucleus, suggesting that this C-terminal region contributes to the steady-state nuclear localization of the intact La protein in uninfected cells. The dl-La retained the enhancing activity of translation initiation driven by poliovirus RNA in rabbit reticulocyte lysates. These results suggest that La protein is cleaved by 3Cpro in the course of poliovirus infection and that the dl-La is redistributed to the cytoplasm. dl-La, as well as La protein, may play a role in stimulating the internal initiation of poliovirus translation in the cytoplasm.     

A case of intracytoplasmic edema of follicular epithelial cells in rat thyroid

Hydropic change of follicular epithelial cells in the thyroid was observed in a female Fischer 344 rat. Microscopically follicular epithelial cells were characterized by edematous swelling with weakly eosinophilic and homogeneous cytoplasm. The cytoplasm was negative for periodic acid-Schiff reaction, and thyroxine- and thyroglobulin-immunohistochemical reactions. Electron-microscopically, a small amount of amorphous substance was noted in remarkably dilated rough-surfaced endoplasmic reticulum (r-ER), and slight regressive changes of cytoplasmic organella were also observed. These morphological changes may indicate that focal intracytoplasmic edema was occurred in r-ER, and that the change belonged to hydropic degeneration of the thyroid follicular cells in the thyroid.     

In vivo autoradiography and nitrosoheptamethyleneimine carcinogenesis in hamsters

Quantitative autoradiograms were made, in vivo, in European hamsters with the use of [14C]nitrosoheptamethyleneimine (260 muCi/animal; time between administration of nitrosamine and killing of animals, 6 hr). In this species, the lung is the principal target, and radioactivity was found in the Clara cells of the bronchial epithelium and in the nitrosoheptamethyleneimine-induced tumors which derive from these cells. Tumors are not induced in the liver, which can metabolize this compound, and labeling is found principally in the cytoplasm, whereas in the target cells there is a high degree of labeling in both the cytoplasm and the nuclei.     

Negligible prevalence of antibodies against Trypanosoma cruzi among blood donors in the southeastern United States

The ultrastructure of alpha-bacteroids in relation to the fat-body cells of the lantern bug Pyrops candelaria was described. The fat-body-cell cytoplasm contained numerous mitochondria, rough endoplasmic reticula, vacuoles, and storage granules. Its nucleus had scattered chromatin materials. The alpha-bacteroid was enveloped by three membrane layers, namely, the plasma membrane, the cell wall, and the membrane envelope. Its cytoplasm contained amorphous dense bodies. The bacteroid reproduced by binary fission. Tracheoles were also found among fat-body cells.     

A histochemical and immunohistochemical study of certain defense mechanisms in the human lacrimal sac epithelium

The mucosal surface of the human lacrimal sac represents an area exposed to exogenous agents including potentially harmful microorganisms. The human lacrimal sac was examined histochemically to identify glycoproteins, and immunohistochemically to identify secretory IgA. Neutral and acid glycoconjugates were detected mainly in the cytoplasm of the surface cells of the columnar stratified epithelial lining. The same reactions were recognized in occasional clusters of secretory cells forming intraepithelial glands in the lining of the lacrimal sac. The presence of secretory IgA in the cytoplasm of the apical epithelial cells was demonstrated. The results indicate that the lacrimal sac mucosa possesses certain active defense mechanisms against ascending infections.     

Ultrastructural detection of surface exposed phosphatidylserine on activated blood platelets

Phosphatidylserine (PS) is normally restricted to the inner leaflet of the plasma membrane of cells (including blood platelets). Upon cell activation PS may become exposed to the outer surface of the cell. Cell membranes with surface exposed PS at the outside form a catalytic surface for coagulation reactions. When platelets are activated with ionophore or with thrombin in combination with thapsigargin, calcium induced scrambling of phospholipids takes place, resulting in PS exposure. Concomitant with PS exposition structural changes take place. On resting and activated platelets we combined the immunocytochemical detection of surface exposed PS with (ultra)structural information. Blood platelets were activated in the presence of annexin V, a protein which binds to PS in the presence of Ca2+. Annexin V was found to bind to lipid bilayers containing more than 5 mole % PS as estimated by binding of fluorescent-labelled annexin V to liposomes with varying PS concentrations. After vitrification, freeze-substitution and embedding of the platelets, annexin V was located on ultra thin sections, as detected by an anti-annexin V antibody and gold labelled protein A. Upon activation, the platelets show two different forms; irregular platelets with unchanged cytoplasm and round cells with apparently diluted cytoplasm. Activation with ionophore initially resulted in both forms, but after ten minutes only round platelets with diluted cytoplasm were observed. Both forms of these platelets as well as the microvesicles were found to be annexin V positive. However upon activation with thrombin in combination with thapsigargin, only the round cells with diluted cytoplasm and microvesicles were annexin V positive, whereas platelets with unchanged cytoplasm, even when microvesicles are present, are negative for annexin V.     

Spatial organization of microtubules and microfilaments in larval and adult salivary glands of Drosophila melanogaster

We examined the distribution of microtubules and microfilaments by conventional fluorescence microscopy and laser scanning confocal microscopy in larval and adult salivary glands of Drosophila melanogaster. The cells of the larval salivary gland epithelium were characterized by the same spatial distribution of microfilaments, whereas microfilament localization was more complex in adult salivary glands, showing some regional differentiation. Microtubules distributed throughout the cell cytoplasm of the larval salivary glands, whereas in adult glands they were mostly observed in the basal or apical cytoplasm of the cells. These observations were related to the secretory process and the mechanism of saliva discharge.