Klaus G. Bensch

Oat‐cell carcinoma of the lung. Its origin and relationship to bronchial carcinoid

Electron‐microscopic examination of normal bronchial epithelium and mucous glands has revealed the presence of cells similar in appearance to Kultschitzky (argentaffin) cells in the intestinal canal. The cells, which possess long cytoplasmic processes, are present in small numbers at all levels of the bronchial tree and are found adjacent to the basement membrane. They contain characteristic cytoplasmic granules referred to as neurosecretory‐type granules, which are similar to those present in intestinal argentaffin cells, adrenal medullary cells and sympathetic nerve endings. Eighteen bronchial carcinoid tumors and 22 oat‐cell pulmonary cancers have also been found to contain similar neurosecretory‐type granules in the tumor cell cytoplasm. On the basis of light‐microscopic similarities and the production of similar common patterns of hormonal disturbances and the possession of similar ultramicroscopic features, it is suggested that oat‐cell pulmonary cancer and bronchial carcinoid tumors are closely related. They may be, respectively, the malignant and locally malignant form of tumors derived from Kultschitzky‐type cells normally found throughout the bronchial tree.

Vinblastine and griseofulvin reversibly disrupt the living mitotic spindle.

Using polarized light we have studied the effects of various mitotic poisons on mitotic spindles of living Pectinaria oocytes; we have studied fixed specimens with phase and electron microscopy. Vinblastine caused attrition and eventual disappearance of spindle structure as rapidly as did colcemid, and subsequent recovery from this treatment was at least as fast as that from colcemid. Griseofulvin, however, was easily the best agent for rapid, reversible, and repeated dissolution of the spindle. Agents that arrest metaphase may act on nondividing cells by interfering with the organization of other gelated structures.

Studies on the bronchial counterpart of the Kultschitzky (Argentaffin) cell and innervation of bronchial glands

The fine structural details of a cell occasionally encountered among the exocrinic cells of human bronchial glands are very similar to those of the intestinal argentaffin (Kultschitzky) cell. Arguments for the existence of a bronchial counterpart to the Kultschitzky cell are presented. Also described are nerve endings encountered between the bronchial glandular cells and in juxtaposition to myoepithelial cells. These are thought to be of the cholinergic type.

Fixation of tissue culture cells for ultrastructural cytochemistry

Abstract Adjustment of the osmolality of buffered gluteraldehyde to isotonic levels allows cytochemical studies of tissue culture cells with the electron microscope. This method will permit similar studies on cells obtained from blood or other body fluids.

Granular Pneumocytes: Electron Microscopic Evidence of Their Exocrinic Function

The contents of the lamelar bodies of granular pneumocytes are normally released into the alveolar lumen. Exposure of guinea pigs to an atmosphere containing carbon dioxide causes the formation of abnormal lamellar bodies and a significant increase in the pulmonary surface tension. The eventual return to a normal pulmonary surface tension coincides with the formation of normal lamellar bodies.

Human Polymorphonuclear Leukocytes: Demonstration of Microtubules and Effect of Colchicine

Microtubules are demonstrable in mature human polymorphonuclear leukocytes, even after prolonged incubation in vitro. These organelles are not seen after treatment with colchicine, which has various functional effects on these cells but does not inhibit phagocytosis.

Absorption of Intact Protein Molecules across the Pulmonary Air-Tissue Barrier

The majority of heterologous serum albumin and globulin molecules introduced into the pulmonary alveoli of dogs are absorbed into the circulatory system antigenically intact. This function of the alveoli has both physiologic and pathologic importance.

Light and electron microscopic studies of acute and chronic thallium intoxication in rats

Abstract The morphologic changes induced by subcutaneous injection of varying doses of thallium acetate in adult male and female Sprague-Dawley rats were studied with the light and electron microscopes. The animals were sacrificed at various intervals within the period of 18 hours to 6 1 2 months after the initial injection. With the light microscope, renal eosinophilic casts, enteritis, and severe colitis were consistently present in the acutely poisoned animals. In the subacutely poisoned animals, frequent foci of perivascular cuffing and a rare focus of recent necrosis were seen in the brain. No changes were noted with the light microscope in the chronically poisoned animals. With the electron microscope, the most consistent changes in all groups of poisoned animals were noted in the kidney, liver, and intestine. In the kidney there was swelling of the tubule cells and partial to total loss of microvilli in many of the swollen cells. In swollen cells of the proximal tubules, the endoplasmic reticulum was dilated and partially ruptured. Intraluminal tubular casts of membranous debris and cytoplasmic organelles were frequently seen in all portions of the renal tubules. Greatly increased numbers of autophagic vacuoles, lysosomes, lipid droplets, and residual bodies were present in tubular cells, particularly in the proximal convoluted tubules. Degenerative changes were frequently present in the mitochondria of the kidney, liver, and intestine; they were sometimes also observed in the brain, seminal vesicle, and pancreas. These changes included swelling of mitochondria and partial or total loss of cristae and mitochondrial granules, increased size and density of mitochondrial granules with occasional electron-lucent cores within these granules, and increased numbers and stacking of mitochondrial cristae. In hepatocytes of subacutely and chronically poisoned animals, there were infrequent accumulations of homogeneous electron-opaque material in the center of mitochondria, with a peripheral displacement of the enlarged and aggregated mitochondrial granules. Autophagic vacuoles and lysosomes were found in increased numbers in all organs examined. Lipid, in the form of droplets, was often increased in hepatocytes of the chronically poisoned animals. No intranuclear or cytoplasmic inclusion bodies were seen. The variety of changes noted in mitochondria and the increased numbers of autophagic vacuoles and lipid droplets in thallium poisoning are not considered specific for thallium, and are similar to changes seen following cellular injury evoked by a variety of agents. The enlargement of mitochondrial granules is thought to be due to the accumulation of thallium within these structures. It is proposed that one mode of action of thallium may be to combine with mitochondrial sulfhydryl groups and thereby interfere with oxidative phosphorylation.

Fibrillar structures resembling leiomyofibrils in endothelial cells of mammalian pulmonary bloodvessels

SummaryEndothelial cells of mammalian pulmonary arteries, arterioles and precapillaries (metarterioles) posses bundled filamentous structures which resemble leiomyofibrils.

Cytochemical differentiation of the guinea pig sperm flagellum with phosphotungstic acid

Guinea pig sperm were treated with ethanolic phosphotungstic acid (E-PTA) after glutaraldehyde fixation with and without refixation in osmium tetroxide. PTA staining differentiated the cortex from the interior of the coarse fibers, and further differentiated the cortex into two segments, one densely stained, the other pale. The internal substance of the peripheral doublets stains heavily with PTA when sperm are not fixed in osmium tetroxide, but the limiting walls around the doublets are not apparent. Outlines of the central filaments, however, are preserved by PTA. PTA-stained sperm do not show the arms on sub-filament A, irrespective of fixation procedures. Structural relationships between the coarse fibers and the peripheral doublets are also brought out by E-PTA. In addition, this cytochemical method revealed a nodule connecting the implantation and basal plates.