The fine structure of epithelial cells from a human esophageal carcinoma cell line and normal esophageal cells in short-term cultures were studied. Different types of cellswere described according to their electron densities. In general they may be subdividedinto dark, light and empty cells. These different types of cells appear to correspond to proliferating, degenerating and dying cells. A comparative study between normal and malignant esophageal epithelial cells revealed the characteristics of cancer cells as follows: wider intercellular space, a greater number of villi, but few desmosomes and tonofilaments, larger and irregular nuclei and larger more distinct nucleoli. of much greater significance is the appearance of aggregated RNP in the cancer cells, a phenomenon heretofore not observed in normal cells. These electron microscopic evidences showed that this cell line originated from squamous epithelial cancer cells. Many nucleopores, each composed of eight subunits, and abundant cytoplasmic fibrils were seen in the neighborhood of part of the nuclear membrane in the cancer cells. The presence of more nucleopores in the cancer cells is in accord with the fact that malignant cells differentiate poorly and metabolize actively. Virus-like particles were seen in normal cells but not in the cancer cells.

ECa 109 cells were heated to 42.5℃ for 60 min.or 90 min.,and to 44℃ for 30 min.The number of microvilli,desmosomes and RER decreased,but tonofilments increased.The polyribosome disaggregated as monoribosome.The mitochondria dilated and mitochondrial granules were observed.The Golgi complex disaggregated.Peri- chromatin granules and more dense heterochromatin were visible in the nucleus.The nucleoli were smaller,and the granular components were lost.The changes of organelles in cytoplasm appeared earlier than those in the nucleus. Recovery of the ultrastructural changes were also observed.After 37℃ for one/day, vacuous cells and microvilli increased in number significantly.Desmosomes,tonofilments, mitochondria,Golgi complexes,RER and polyribosomes all showed a recovering ten- dency.But,at the same time,a lot of lysosomes could be seen.On the fourth day of recovery,the structure of nuclear envelop remained indistint.The nucleoli varied in shape,with disappearance of granular components.During recovery,the organelles in cytoplasm restored earlier,while nucleic changes recovered later. The mechanism of ultrastructure changes induced by hyperthemia were discussed.

The effect of cytochalasin D on ECa109 esophageal sqamous cancer cells was studied. When (ECa109) cells were treated with 0.2～1?g/ml cytochalasin D, small epithelial cells with a few microvilli could be seen. After incubation with 0.5?g/ml of cytochalasin D for one or three days, irregular buds containing endoplasmic reticulum, mitochondria and Golgi complexes grew out from the surface of the epithelial cells. The target-shaped mitochondria, the "confronting cisterna" of the endoplasmic reticulum, ring-shaped endoplasmic reticulum and disaggregated Golgi complexes were appeared in the cytoplasm. After treatment with 0.2?g/ml of cytochalasin D for one day multinucleated epithelial cells appeared. There were 2～6 nuclei, with different in size and shape. Some nuclei were fully enclosed with neuclear envelops and the others only partically. Mitotic cells could be seen too. The effect of cytochalasin D on the structure and function of the epithelial cells and the different roles played by the actin and tubulin in keeping the normal function of the cytoskeleton system of the ECa109 cells were discussed.

A comparision of the ECa 109 esophageal epithelial carcinoma cells and normal esophageal epithelial cells was made. Electron microscopically these two cells revealed remarkable differences. The normal esophageal epithelial cells had narrow intercellular space, fewer microvilli, more desmosomes and tonofilaments, with small and round nucleus. No polyribosome could be seen. The ECa 109 cells had wider intercellular space, more microvilli, fewer desmosomes and tonofilaments, larger and irregular nucleus, large and distinct nucleolus. Besides, the appearance of polyribosome was characteristic of cancer cells. Thus, the following characteristics were used as makers of cell differentiation: 1. less microvilli; 2. abundant tonofilaments; 3. more desmosomes; 4. monoribosomes; 5. round nucleus; 6. small nucleus/cytoplasma ratio.Upon addition of 2％ DMSO ECa 109 under went striking morphological changes resembling the terminal differentiation stage of normal esophageal epithelial cells.Inaddition, after DMSO treatment, circular Golgi complexes surrounded by small vesicles could be seen. Small vesicles and primary and secondary lysosomesappeared too. Electron-dense particles with halo were easily seen in the nuclei.

The surface and ultrastructure of the interphase and mitotic ECa 109 esophagealcancer epithelial cells were investigated by means of scanning and transmission electronmicroscopes.The electron microscopies revealed that cells grown in culture haddifferent external appearances during the different phases of cell cycle.At interphase,the cells were flattened and irregular in shapes,the surface were covered with microvilli.Centrosome,tonofilaments,mitochondria could be found in the cytoplasm.The largeand irregular shaped nucleus was located at the centre.It had one or more nucleoli.During the mitotic phase the cells were spherical and they became first cylindricaland then dumb-bell in shapes,Finally,they divided into daughter cells.There werespindle area and non-spindle area in the cell.The former was at the center of thecell and the latter occupied the outer part of the cell.In the spindle area,thechromatin clumped and the centrioles were prominent,the chromosomes were close tothe equatorial plate.The spindle tubules were seen radiating from the centriole andattached to chromosome at the kinetochore,and among them there were a fewmitochondria.In the non-spindle area,the cell organelles could be observed but fewGolgi complex present.It was shown that many changes of the cells could be foundduring mitosis,and that the spindle-fibers,filopodia,rod-like elements and the cellmembranes might play an important role during mitosis.

The phagocytosis of opsonic chicken erythrocytes which were engulfed byMMC-1 cells was studied by means of transmission electron microscopy.After incu-bating chicken erythrocytes with the serum of rabbit-anti chicken antibody.MMC-1cells were surrounded by 1 to more than 10 opsonized erythrocytes.The EA rosetteswere formed.At first,opsonized erythrocytes attached to the MMC-1 cells in somepoints.At the site of interaction of opsonized erythrocytes with MMC-1 cells theelectron dense bands which were the specialization of the MMC-1 cell plasma mem-brane appeared.Then many projections of the erythrocytes were engulfed intoMMC-1 cells.When part of the erythrocyte was engulfed by macrophage,a collar-like structure arround the erythrocyte could be seen.Partially engulfed erythrocyteslooked like a dumbbell.The engulfed erythrocytes were irregular in shape.Thedensity of engulfed erythrocytes became faint gradually.The round ring with highelectron density appeared and enlarged in erythrocytes.It was shown that the opso-nized erythrocytes which formed EA rosettes were engulfed by MMC-1 phagocyte.After engulfing many erythrocytes,MMC-1 cells might degenerated or be engulfedby other MMC-1 cells.It was proved that Fc receptors presented on MMC-1 cells.Many mitochondria were easily found in MMC-1 cells,they were responsible forenergy supplies.Extruding of engulfed nuclei from macrophage could be seen too.It was shown that MMC-1 cells had the characteristics of macrophage and it wasestablished by cell fusion of phagocyte and thymoma cell.

Preparations of cell-free supernatant from Rous sarcoma "?????" were inocu-lated onto the chorio-allantoic membranes (CAM) of the chick embryos of 7--9 days in-cubation. The inoculated portions of the CAM were removed at various intervals from6 hours to 10 days afterwards. The tissues were fixed in Carnoy's solution and werestained with methyl green-pyronin for nucleic acid, Alcian blue-hematoxylin or Alcianblue-alum cochineal for acid polysaccharide and toluidine blue for metachromatic reac-tion. The pathogenesis of the Rous sarcoma of the inoculated CAM and the histo-chemical reaction of the nucleic acid and acid polysaccharide have been followed by his-tological examinations. Recognizable macroscopic lesions consisting of membrane opacity, focal thickening,oedema and discrete nodules in the inoculated CAM appeared from the first day on-ward. Distinctive hemorrhagic lesions and pocks were observed on the 3rd to the 5thday. Tumor masses of different sizes appeared from the 7th to the 9th day. In casethe CAM were inoculated with horse serum-saline, no or only slight reaction was ob-served, and the normal thickness and structures of the CAM were generally maintained. Three successive stages of the Rous sarcoma on the inoculated CAM weredistinguished: (1) Focal ecto-mesodermal proliferation with formation of earlytumor-like nodules; (2) Extreme ectodermal hyperplasia and early mesodermalsarcoma-like proliferation; (3) Ectodermal necrosis and extensive malignant growthof the mesodermal neoplastic cells. The fibroblasts, pyroninophilic round cells andthe ectodermal cells were the main types of cells concerned in the developmentof tumors following infection of the CAM Rous virus. The fibroblasts transformedinto tumor cells and became the most conspicuous elements of the Rous sarcoma. Thepyroninophilic round cells were considered to be belonging to the basophilic myelocyteseries, according to their morphological and staining characteristics. Their possible rolein the tumor infiltration was discussed. The intensity of the nucleic acid in the CAM cells increased along with the increaseof histopathological changes at the inoculated area of the membrane. The possible sig-nificance of their parallel relationship was discussed. Alcian blue staining of the growing tumor tissue demonstrated the presence of acidpolysaccharide reaction in the ground substance. The intensity increased with the increaseof the malignancy of the neoplastic cells. This material is non-metachromatic whenstained with toluidine blue and could be removed by treatment with testicular hyaluroni-dase for 3--5 hours. The mucin present is considered to be of a hyaluronic acid nature.

Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whether pretreatment with monoclonal antibody against TNF-α (TNF-α MoAb) would affect the release of D(-)-lactate after local gut ischemia followed by reperfusion. Methods Anesthetized Sprague-Dawley rats underwent superior mesenteric artery occlusion for 75 min followed by reperfusion for 6 hr. The rats were treated intravenously with either TNF-α MoAb (20 mg/kg) or albumin (20 mg/kg) 30 min prior to the onset of ischemia. Plasma D(-)-lactate levels were measured in both the portal and systemic blood by an enzymatic spectrophotometric assay. Intestinal TNF-αmRNA expression as well as protein levels were also measured at various intervals. In addition, a postmortem examination was performed together with a macropathological evaluation based on a four-grade scoring system.Results Intestinal ischemia resulted in a significant elevation in D(-)-lactate levels in the portal vein blood in both the control and treatment groups ( P ＜0.05). However, animals pretreated with TNF-α MoAb at 6 hr after reperfusion showed significant attenuation of an increase in both portal and systemic D(-)-lactate levels when compared with those only receiving albumin (P ＜ 0.05). In the control animals, a remarkable rise in intestinal TNF-α level was measured at 0.5 hr after clamp release ( P ＜ 0.01); however, prophylactic treatment with TNF-α MoAb completely annulled the increase of local TNF-α levels seen in the control animals. Similarly, after anti-TNF-α MoAb administration, intestinal TNF-α mRNA expression was markedly inhibited, which showed significant differences when compared with the control group at 0.5 hr, 2 hr and 6 hr after the release of occlusion ( P ＜ 0.05-0.01 ). In addition, the pathological examination showed marked intestinal lesions that formed during ischemia, which were much worse upon reperfusion,particularly at the 6 hr time point. These acute injuries were obviously attenuated in animals receiving TNF-α MoAb.Conclusions It appeared that acute intestinal ischemia was associated with failure of the mucosal barrier, resulting in increased plasma D(-)-lactate levels in both portal and systemic blood. These results suggest that TNF-α appears to be involved in the development of local damage associated with intestinal ischemic injury. Moreover, prophylactic treatment with TNF-α MoAb exerts preventive effects on ischemia/ reperfusion-induced circulating D (-)-lactate elevation and gut injury. ( J Geriatr Cardiol 2004;1(2):119-124. )