Ultrastructure of oral sarcoma

Sarcoma of the oral region is extremely rare and ultrastructural studies of the tumor are limited in number. We collected oral sarcomas, such as fibrosarcoma, malignant fibrous histiocytoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma, angiosarcoma, alveolar soft-part sarcoma, solitary plasmacytoma, and osteosarcoma, and performed ultrastructural studies of these tumors. The value of these studies for an understanding of the biological behavior of the tumors was then investigated. In these studies, electron microscopic examinations of oral sarcoma were of assistance in our attempt to establish correct diagnosis and histogenesis. Data from the studies of oral sarcoma by light microscopy, electron microscopy, and immunohistochemistry should be accumulated.     

Active matrix metalloproteinases in the tear fluid of individuals with vernal keratoconjunctivitis

Corneal epithelial lesions distinguish vernal keratoconjunctivitis (VKC) from other ocular allergic diseases. Such lesions result from degradation of the corneal epithelial basement membrane, which comprises mostly type IV collagen and laminin. Matrix metalloproteinase 2 (MMP-2) and MMP-9 catalyze the degradation of these 2 extracellular matrix proteins. The possible role of MMP-2 and MMP-9 in the pathogenesis of corneal lesions associated with VKC was investigated by assaying tear fluid for the presence of these enzymes. Tear fluid was collected from 6 eyes of 6 patients with active VKC, 14 eyes of 14 patients with active allergic conjunctivitis, and 6 eyes of 6 nonallergic healthy volunteers. Gelatin zymography revealed that the tear fluid of healthy volunteers contained inactive proforms of both MMP-2 and MMP-9 but not the active forms of these enzymes. Active forms of MMP-2 or MMP-9 were detected in a minority of patients with allergic conjunctivitis. However, with the exception of one individual for whom active MMP-9 was not detected, tear fluid from all patients with VKC contained both proforms and active forms of MMP-2 and MMP-9. These results implicate MMP-2 and MMP-9 in the pathogenesis of corneal epithelial disorders associated with VKC.     

The effect of 12-O-tetradecanoylphorbol-13-acetate on hormone-induced differentiation of rat parotid gland in organ culture

Parotid glands of 5-day-old rats were maintained in DM-153 synthetic, serum-free medium in organ culture for 24 to 48 hr. Differentiation of acinar cells in vitro, as revealed by an increase in amylase activity in the gland and in the culture fluid, as well as by the immunocytochemical demonstration of amylase in the acinar cells, was accelerated by insulin, prednisolone, and l-thyroxine added to the culture medium. The potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate (10^?7M) inhibited both the unstimulated and hormone-stimulated differentiation of the gland without causing cellular degeneration or necrosis.     

Glomerular expression of cell-cycle-regulatory proteins in human crescentic glomerulonephritis

To elucidate the mechanism underlying crescentic formation, we assessed the phenotypic characterization and cell-cycle protein expression in human crescentic glomerulonephritis (CRGN). Kidney tissue specimens taken from CRGN patients (10 patients with pauci-immune type rapidly progressive glomerulonephritis (RPGN), 2 patients with Henoch-Schönlein purpura nephritis, and 1 patient with IgA nephropathy) were examined immunohistochemically. Most of the cellular components of the crescents expressed cytokeratin, whereas few cells expressed PHM-5. CD68-positive cells were minor components of cellular crescents, indicating that the major principal cellular component of the crescents is made up of cells with the parietal glomerular epithelial cell (PEC) phenotype. Additionally, serial section analysis revealed that Ki-67-positive cells in the crescents were frequently cyclin-A positive and Bcl-2 positive, but seldom cyclin-B₁ positive. Moreover, the expression of cyclin-dependent kinase inhibitor p27^Kip1 was low in the cellular crescents, despite being exclusively positive in podocytes within the same section. We concluded that the major component of the cellular crescents is made up of PECs and that apparent expression of cyclins and Bcl-2 and restrained expression of p27^Kip1 may be synergistically associated with the development of cellular crescents in human CRGN.     

IMMUNOHISTOCHEMICAL STUDY ON THE DISTRIBUTION AND SIGNIFICANCE OF MONONUCLEAR CELLS IN HUMAN BREAST CARCINOMA

Lymphocyte subsets in the tumor nests of breast carcinoma were immunohistochemically investigated and a quantitative analysis was added. The majority of cases showed predominance of T cell and suppressor T cell (T8). A decrease in number of lymphocyte subsets and the helper T (T4)/T8 ratio in the stroma of tumor nests correlated well with the progression of clinical stage and the presence of metastasis. This correlation could not be found in the peripheral region of the tumor nests. Macrophages and NK cells were infrequently observed only in the peripheral region of ductal carcinoma. T cell infiltration was prominent in medullary carcinoma with lymphocyte infiltration (MC), and macrophages, NK cells, and T zone histiocytes were frequently encountered. For the purpose of knowing the activity of T cells, IL-2 receptor (Tac) and transferrin receptor were examined irnmunohistochemically. The fact that a few activated T cells were found only in the peripheral region of tumor nest suggested the local immune response in ductal carcinoma not to be so active as to reject the tumor cells. Since numerous activated T cells were recognized in the tumor nests of MC, this type of breast carcinoma was thought to have a higher immune reactivity. There was little evidence indicating NK cells to play a role for natural cytotoxicity in breast carcinoma. ACTA PATHOL. JPN. 36 1455-1468, 1968     

Overexpression of lipoprotein lipase in transgenic rabbits leads to increased small dense LDL in plasma and promotes atherosclerosis

Lipoprotein lipase (LPL) is a key enzyme in the hydrolysis of triglyceride-rich lipoproteins. Previous studies using transgenic mice and rabbits have demonstrated that high level of LPL activity in adipose and skeletal muscle protects against diet-induced hypercholesterolemia and subsequently prevents aortic atherosclerosis. However, it is unknown, per se, whether increased LPL activity itself is antiatherogenic, or whether the antiatherogenic effect of LPL is dependent upon the LPL lipid-lowering effect. To address this issue, we fed LPL transgenic and littermate rabbits diets containing different amounts of cholesterol (0.3-0.6%) adjusted to maintain their plasma cholesterol concentrations at similarly high levels for 16 weeks. We analyzed their lipoprotein profiles and compared their susceptibility to atherosclerosis. The results showed that the overexpression of LPL in transgenic rabbits reduced remnant lipoproteins (beta-VLDL, d<1.006 g/ml) but concomitantly led to a significant increase of the large (d=1.02-1.04 g/ml) and small LDLs (d=1.04-1.06 g/ml) compared to the amounts in control rabbits. Furthermore, we found that with equally high hypercholesterolemia, transgenic rabbits developed 1.8-fold more extensive aortic atherosclerosis than control rabbits. To examine the hypothesis that altered lipoprotein profiles may be responsible for the enhanced atherosclerosis in transgenic rabbits, we studied the atherogenic properties of apoB-containing lipoproteins in vitro. These studies revealed that small-sized LDLs of transgenic rabbits were more susceptible to copper-induced oxidation and had higher affinity to biglycan than large remnant lipoproteins. We conclude, therefore, that LPL exerts a dual function in terms of its atherogenicity, namely antiatherogenicity, through enhancing receptor-mediated remnant lipoprotein catabolism and proatherogenicity via the generation of a large amount of small-sized LDLs. At an equal atherogenic-cholesterol level, small and dense LDLs are more atherogenic than large remnant lipoproteins.     

Inhibitory effect of oral administration of Lactobacillus casei on 3-methylcholanthrene-induced carcinogenesis in mice

The present study was designed to determine whether tumor induction by 3-methylcholanthrene (MC), a carcinogenic hydrocarbon, can be inhibited by oral administration of Lactobacillus casei strain Shirota (LC). C3H/HeN mice were divided into four groups and assigned to the following treatments: treated with MC and given control or LC-containing diet; treated with vehicle only and given control or LC-containing diet. MC (1 mg) was injected intradermally at 7 weeks of age and the tumor incidence was monitored; LC was mixed into a diet at a concentration of 0.05% (w/w) and the diet was fed from the day of MC injection throughout the study. Spleen cells were analyzed for the immune parameters at 12 and 16 weeks after the MC injection. Oral feeding of mice with LC reduced tumor incidence (P < 0.05). MC treatment lowered the in vitro response to concanavalin A (Con A) of spleen cells, the secretion of interleukin-2 in spleen cell culture after stimulation of the cells with Con A and the proportions of CD3⁺, CD4⁺ and CD8⁺ splenic cells. However, the analysis of the spleen cells obtained from the mice treated with MC and given the LC-containing diet revealed that these disrupted host immune parameters were maintained at the level of normal controls. These results suggest that oral feeding of mice with LC inhibits MC-induced tumorigenesis by modulating the disrupted host immune responses during MC carcinogenesis. Received: 14 April 1999     

Localization of T lymphocytes and macrophages expressing IL-1, IL-2 receptor,IL-6 and TNF in human aortic intima. Role of cell-mediated immunity in human atherogenesis

Recent observations have demonstrated the presence of activated T lymphocytes and macrophages in human atherosclerotic lesions. Cells found within these lesions produce cytokines that alter vascular homeostasis in a manner that promotes atherogenesis. To elucidate the role of these immunocompetent cells in human atherosclerosis, the localization of various cytokines with an analysis of immunophenotypic features of the cellular infiltrates was studied in normal aortas from children; and in later phases of the disease (including fatty streaks and fibrous or atheromatous plaques). Semi-quantitative analysis of cytokine-expressing cells was also investigated with serial sectioning. In 4 of 9 young subjects, the grossly normal aorta contained relatively cell-rich areas which were located preferentially around the ostia of intercostal arteries and were composed of isolated or layered T lymphocytes and macrophages. In these prelesional areas, interleukin-1 (IL-1), IL-2 receptor (IL-2R) and tumour necrosis factor (TNF) were detected in the cytoplasm of the infiltrating cells, whereas no detectable reactivity was noted for IL-2, IL-6, interferon-γ (IFN-γ) or lymphotoxin (LT). In fatty streaks and full-grown atheromas including “cap” and “shoulder” regions, various numbers of T lymphocytes, macrophages and macrophage foam cells were present. In these lesion areas, especially where the cellular infiltrates were numerous, macrophage foam cells and smooth muscle cells expressed not only IL-1 and TNF but also IL-6. The ratio of IL-2R positive cells showed a tendency to decrease with advance of the disease process. Electron-microscopic examination of lesion areas demonstrated ultrastructural aspects of the cognate cellto-cell interaction, as shown by the direct apposition of lymphocytes to macrophages or macrophage foam cells. These results suggest that a specific in situ, cell mediated hypersensitivity plays a pivotal role in the nascent as well as the progression stages of human atherosclerosis.     

Influence of insulin immobilization to thermoresponsive culture surfaces on cell proliferation and thermally induced cell detachment

Temperature-responsive culture dishes immobilized with insulin have been fabricated and studied to shorten cell culture periods by facilitating more rapid cell proliferation. Cells are recovered as contiguous cell sheets simply by temperature changes. Functionalized culture dishes were prepared by previously reported electron beam grafting copolymerization of N-isopropylacrylamide (IPAAm) with its carboxylate-derivatized analog, 2-carboxyisopropylacrylamide (CIPAAm), having similar molecular structure to IPAAm but with carboxylate side chains to tissue culture polystyrene dishes. Insulin was then immobilized onto culture dishes through standard amide bond formation with CIPAAm carboxylate groups. Adhesion and proliferation of bovine carotid artery endothelial cells (ECs) were examined on these insulin-immobilized dishes. Insulin immobilization was shown to promote cell proliferation in serum-supplemented medium. Increasing the grafted CIPAAm content on the tissue culture surfaces reduces cell adhesion and proliferation, even though these surfaces contained increased amounts of immobilized insulin. This result implies that a discrete balance exists between the amount of CIPAAm-free carboxylate groups and immobilized insulin for optimum cell proliferative stimulation. Cells grown on the insulin-immobilized surfaces can be recovered as contiguous cell monolayers simply by lowering culture temperature, without need for exogenous enzyme or calcium chelator additions. In conclusion, insulin-modified thermoresponsive culture dishes may prove useful for advanced cell culture and tissue engineering applications since they facilitate cell proliferation, and cultured cells can be recovered as viable contiguous monolayers by merely reducing culture temperature.