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Biomedical subjects

D Oda

Publications and source records attributed to D Oda.

17 recordsLinked to original sources
PubMed1992

Intraoral infantile hemangiopericytoma: literature review and addition of a case.

A rapidly growing neoplasm in the buccal mucosa of a 4-month-old baby was excised. By light and electron microscopy the neoplasm had features that were similar to those described in infantile hemangiopericytoma, a rare neoplasm of vascular origin. By light microscopy the neoplasm was multilobular with highly proliferating round to spindle-shaped cells interspersed with numerous vascular spaces. Ultrastructurally, round to elongated cells with short processes, pinocytotic vesicles, reduplicated basal lamina, and basal lamina-like material were identified. Immunohistochemically the cells were weakly positive with antibodies to vimentin, focally positive with HHF-35, a smooth-muscle cell antibody, negative with antibodies to S-100 protein, T-200, neuron-specific enolase, neurofilaments, desmin, and cytokeratins 35BH11 and 34BE12. Blood vessels were positive with Ulexeuropaeuslectin, but tumor cells were negative. Reticulin stain decorated a delicate network of fibrils surrounding tumor cells and vascular spaces. Clinically the neoplasm did not recur and the baby has been disease free for more than 26 months. The difficulty of the histologic diagnosis of this neoplasm is discussed and the literature is reviewed, with special emphasis on lesions occurring in the oral cavity.

Diagnosis, Differential↗
PubMed1992

Smooth muscle and epithelial cells express specific binding sites for the C1q component of complement.

In injury and inflammation, interactions of complement C1q with C1q receptors may provide attachment sites for cell localization and tissue regeneration. Cultured smooth muscle cells (58%), epithelial cells (26%), and endothelial cells (25%) attach to C1q-coated surfaces, while only 6% of cultured B cells (Raji) attach. Endothelial and Raji cells express C1q receptors, but C1q receptors (C1qR) on smooth muscle cells and epithelial cells have not previously been demonstrated. Evidence is provided that smooth muscle cells express an average of 1.5 x 10(6) C1qR/cell (K alpha = 10(8) M-1) and that epithelial cells express an average of 0.7 x 10(6) C1qR/cell (K alpha = 1.4 x 10(8) M-1). Binding properties of C1qR, and immunoreactivity to anti-C1qR antibodies, are characterized. The antibodies specifically recognize a 67-kDa component of smooth muscle cell lysates and inhibit cell attachment to C1q substrates. We conclude that distribution of C1qR may be ubiquitous; binding properties, size, and antigenicity of various C1qR may be related, but adhesive function may be tissue specific.

Animals↗
PubMed1992

Interaction of Porphyromonas gingivalis with gingival epithelial cells maintained in culture.

Interactions between Porphyromonas gingivalis and gingival epithelial cells were investigated. Gingival epithelial cells were cultured from surgically removed gingival tissue. Electron microscopy demonstrated adherence of P. gingivalis to the cell membranes and microvilli followed by internalization of the bacteria into the epithelial cell cytoplasm. Saliva from healthy and periodontally diseased patients inhibited P. gingivalis association with the epithelial cells. Attachment to and penetration of gingival epithelial cells by P. gingivalis may be important virulence factors in periodontal disease. Salivary molecules may play a role in modulating these interactions.

Bacterial Adhesion↗
PubMed1992

Odontogenic myxoma: histochemical and ultrastructural study.

Three cases of odontogenic myxoma are presented, two of which were located in the mandible and one in the maxilla. All cases demonstrated similar morphology by light microscopy. Immunohistochemical studies demonstrated positive reaction with antibodies to vimentin and actin, and negative reaction to antibody to S-100 protein. A 127-day-old human tooth bud was used as a control. The ultrastructural features performed on Case 3, when combined with the immunohistochemical findings suggest that the cells comprising odontogenic myxoma are of myofibroblastic origin.

Actin Cytoskeleton↗
PubMed1992

Neutrophil-mediated damage to human gingival epithelial cells.

Polymorphonuclear leukocytes (PMNs) have been implicated in the pathogenesis of inflammatory gingivitis and periodontitis. To further study the role of PMNs in mediating gingival injury, we cocultured these cells in vitro with monolayers of human gingival epithelial cells. Scanning electron microscopy revealed that the epithelial cells were homogeneous and SDS-PAGE/immunoblot analysis identified the presence of keratins K3, K13 and the K6/16 pair which authenticated the oral origin of the cells. Injury to the gingival cells was determined by scanning electron microscopy and measurement of cell detachment and cytolysis. Unstimulated PMNs produced minimal lysis or detachment, but PMNs stimulated by phorbol myristate acetate produced marked epithelial cell detachment without lysis, which was time- and PMN-dose-dependent. Supernatants of activated PMNs were similarly effective, indicating that the mediator was a stable soluble substance. Elastase and cathepsin G, two neutral proteases of PMN origin, produced time- and concentration-dependent detachment of gingival epithelial cells, suggesting that these enzymes may mediate this form of injury. In other studies, gingival epithelial cells were exposed to PMN myeloperoxidase (MPO), chloride and glucose plus glucose oxidase (GO) as a hydrogen peroxide (H2O2) generating system. The toxic oxygen species produced by this system caused lysis of the epithelial targets which was dependent on the duration of incubation and the concentrations of MPO and GO. Azide, an inhibitor of MPO, and catalase, a scavenger of H2O2, inhibited the lytic activity of this system. Scanning electron micrographs of gingival epithelial cells cocultured with activated PMNs showed lifting of the cells from the plating surface, while target cells attacked by the MPO system revealed extensive damage of cell membranes. These studies indicate that activated PMNs cause nonlytic detachment injury to gingival epithelial cells which may be mediated by digestion of their extracellular matrix by granule neutral proteases. Furthermore, PMN MPO is capable of generating toxic oxygen species which can lyse these epithelial cells. Collectively, these actions could have profound adverse effects on the function and integrity of the gingival epithelium.

Cell Death↗
PubMed1991

Comparison of elemental concentrations in the acinar cells of the human labial salivary gland.

Two types of acinar cells were observed in human labial glands by conventional and analytical electron microscopic and light microscopic techniques. The predominant type contained large and prominent secretory granules that were strongly mucicarmine and PAS (with and without diastase) positive. The second type contained small, lacy, secretory granules, and these cells were faintly positive with these stains. The elemental contents of the two types of granules were measured by analytical electron microscopy using digital mapping and spot analysis applied to freeze-dried cryosections prepared from gland slices incubated in vitro under non-stimulated conditions. The large secretory granules had significantly higher Ca, S and Mg concentrations and significantly lower Cl and K concentrations than the small granules. The difference in elemental contents probably reflects differences in the content of secretory macromolecules. Specifically, the S content is thought to reflect the anionic properties of the secretory macromolecules, while the levels of divalent cations are thought to be determined by electroneutrality requirements for macromolecular folding and storage. No differences were found in nuclear or cytoplasmic elemental concentrations between the two cell types.

Adult↗
PubMed1991

Proliferating oral epithelial cells in culture are capable of both extracellular and intracellular degradation of interstitial collagen.

The potential of epithelial cells to degrade interstitial collagen was studied by culturing human masticatory mucosa on decalcified dentin matrix. Morphological changes were observed in the underlying collagen substratum and in the connective tissue of the explant. Degradation of the substratum was initiated two days after the first contact with epithelial cells exhibiting basal cell markers. Electron microscopic studies confirmed extensive collagen degradation in the vicinity of these cells. No collagen degradation was observed underneath the connective tissue portion of the explant. Experiments in which the explant was partially separated from the underlying substratum by a filter further showed that connective tissue was apparently not involved in the collagen degradation by the epithelial cells. Lysis of connective tissue of the explant was observed in association with epithelial cells that showed a disrupted basal lamina and release of vesicular material from the exposed cell membrane. Collagen fibers were visible inside some epithelial cells suggesting intracellular collagenolysis. Primary cultures of human gingival epithelial cells and porcine periodontal ligament epithelial cells (epithelial cell rests of Malassez) that expressed similar basal cell cytokeratins as the active cells of the mucosal explants secreted collagenase, gelatinase and TIMP to the culture medium. They also contained acid collagenolytic proteinases. When cultured on a porous polycarbonate membrane the epithelial cells secreted collagenolytic enzymes from the pores at cell membrane sites lacking basal lamina. These results provide evidence that proliferating basal epithelial cells have a strong capacity for collagen degradation. It seems that the absence of basement membrane is the signal for these cells to secrete matrix degrading enzymes.

Cell Division↗
PubMed1991

Synthesis of type VIII collagen by epithelial cells of human gingiva.

The composition of the extracellular matrix produced by epithelial cells in contact with metabolically inert substrata was studied with antibodies specific for type VIII collagen. Type VIII collagen was present in the cell layer of cultured gingival epithelial cells, and at the epithelium-substratum interface of an explant culture model for junctional epithelium. Samples of the epithelial attachment apparatus (EAA) in vivo were collected by removing the junctional cells directly attached to the tooth (DAT cells) and the associated EAA matrix. The amount of material collected was sufficient for biochemical analysis of both intra- and extracellular components of the junctional cell-EAA complex. Immunological examination of the samples revealed that type VIII collagen was associated with epithelial cells forming the EAA in vivo. We suggest that this collagen type functions in the extracellular space as an attachment-promoting factor for gingival epithelial cells at the tooth surface.

Adult↗
PubMed1991

Long-term culture and partial characterization of dog gallbladder epithelial cells.

We describe the successful isolation and maintenance of primary cultures of dog gallbladder epithelial cells. The surgically removed gallbladder was treated with trypsin/EDTA for 45 minutes and epithelial cells were collected and resuspended in Eagle's minimum essential medium with 10% fetal calf serum, and plated on Vitrogen-coated culture dishes. Each gallbladder yielded approximately 12 to 15 x 10(6) columnar epithelial cells, greater than 95% of which were viable by trypan blue exclusion. In culture, cells maintained their polarity. They were arranged and grew in small and tight clusters that coalesced at confluency. When examined using transmission electron microscopy, prominent and numerous microville were identified on the apical portion of the plasma membrane. Cells were connected by well-formed desmosomes. Scanning electron microscopy revealed clusters of polyhedral cells with numerous papillary projections. Immunohistochemical studies demonstrated uniform staining of cells to keratin 35BH11 and AE1. Histochemical studies were positive for gamma-glutamyl transpeptidase and negative for glucose-6-phosphatase and albumin. Cells incorporated [3H]uridine into intracellular proteins and [14C]glucosamine into tissue and secreted mucous glycoproteins linearly over 2 to 24 hours. Flow cytometry studies demonstrated a consistent and reproducible number of cells (10 to 12%) at S-phase. However, the number of cells at S-phase was dramatically reduced to almost negligible as cells reached confluency. This method of culturing primary dog gallbladder epithelial cells is highly reproducible and reliable. These cells preserve their state of differentiation, polarity, histochemical and immunohistochemical profile, morphologic, and metabolic integrity with repeated passaging or after being frozen. [3H]Thymidine uptake is well maintained, although doubling time shows a trend of decreased cell duplication with time. This technique offers the opportunity to study the electrophysiologic, metabolic, and immunologic properties of epithelial cells.

Animals↗
PubMed1990

Human oral epithelial cell culture I. Improved conditions for reproducible culture in serum-free medium.

Gingival tissue from healthy adult human donors was used as a source of epithelial cells for culture. An overnight incubation of this tissue with dispase facilitated the mechanical separation of the surface epithelium from the underlying fibrous connective tissue. This step minimized culture contamination with fibroblasts. The epithelium was then trypsinized to prepare a single cell suspension. The cell pellets were collected by centrifugation and resuspended in keratinocyte growth medium, incubated at 37 degrees C and 5% CO2 in a humid atmosphere. Primary cultures grew in small islands that coalesced at confluency. Immunohistochemistry demonstrated uniform staining of the cells with antibodies to keratins of stratified squamous epithelium. Ultrastructurally, the cells contained distinct intermediate filaments. When cells were grown in media with low calcium (0.15 mM), cell-to-cell contacts were via interlacing papillary projections with no desmosomes. However, when cells were grown under physiologic calcium (1.2 mM), desmosomes were prominent and well developed. Cells were maintained in culture for over 100 d (7 passages).

Adult↗
PubMed1990

Human oral epithelial cell culture. II. Keratin expression in fetal and adult gingival cells.

Epithelial cells from human fetal and adult gingiva were cultured in keratinocyte growth medium (KGM), a serum-free medium. The expression of keratin proteins in these cells was evaluated using immunohistochemistry and SDS-PAGE-immunoblot analysis and compared with expression in the tissue. Keratins 5, 6, 14, 16, and 19 were identified in cells cultured from both fetal and adult tissues. K19 was localized in basal cells of fetal oral tissue but was not seen in adult gingiva (except for scattered Merkel cells). K1 and K10 were expressed in tissue, but not in cultured cells. The keratin profiles of cultured epithelial cells from several adult donors were similar and were identical in cultures from primary through Passage 5. K13, a differentiation-specific keratin, was expressed in all suprabasal cells of fetal oral epithelium, but shows only spotty expression in adult gingival tissue. K13 was expressed in cultures of fetal cells, but very weakly or not at all in cultures of adult cells. K13 expression was greater in cultures grown with physiologic calcium concentrations (1.2 mM) than in those grown at 0.15 mM or less. Our findings are consistent with basal-like characters of these cells in 0.15 mM calcium growth conditions. Differentiation of fetal oral cells in culture to the suprabasal basal cell stage in 1.2 mM Ca2+ is shown by the expression of K13.

Adult↗
PubMed1990

Instability of the myofibroblast phenotype in culture.

Myofibroblasts are cells that have features of both smooth muscle cells and fibroblasts. Myofibroblasts from rat granulation tissue were studied using a coordinated biochemical and morphological approach. These myofibroblasts were maintained in culture for more than 17 passages. After establishing that these cells were indeed myofibroblasts by immunohistochemical and ultrastructural criteria, their biochemical parameters and phenotypic stability were studied. Rat dermal fibroblasts grown under similar conditions served as controls. Biochemically, it was found that both cells produced similar types of procollagens, namely collagens I and III, in similar proportions at or near a 1:1 ratio. However, myofibroblasts at early passage produced threefold more procollagens than did fibroblasts at the same stage of passage, while similar quantities were produced in each at late passage. These observations for procollagens were confirmed by separate studies for collagens, as measured by hydroxyproline determinations. Such differences were also reflected ultrastructurally. Secretory vesicles were identified in myofibroblasts at early stage, but not at late stage of passaging. No such vesicles were seen in fibroblasts at any stage of passage. In conclusion, myofibroblasts are active secretory variants of fibroblasts which have an unstable phenotype in culture and become indistinguishable from fibroblasts at late passage.

Animals↗
PubMed1990

Oral histoplasmosis as a presenting disease in acquired immunodeficiency syndrome.

A 43-year-old homosexual man visited his dentist with painful, nodular, ulcerated lesions on the soft palate, right buccal mucosa, and right posterior maxillary gingiva. Serologic studies for exposure to human immunodeficiency virus, performed before biopsy, were positive. Biopsy of the maxillary gingiva demonstrated sheets of histiocytes containing small intracellular yeasts, which on culture were identified as Histoplasma capsulatum. Bilateral leukoplakic lesions with some vertical furrowing involving the lateral borders of the tongue were also noted. Histologically, hyperkeratosis and fungal hyphae were identified. The patient was treated for histoplasmosis with amphotericin B, which resulted in significant improvement of the oral lesions. He was subsequently hospitalized for fatigue and dyspnea and was found to have Pneumocystis carinii pneumonia. Pulmonary status deteriorated within a 3-week period, and the patient died. Autopsy findings were negative for histoplasmosis but positive for necrotizing and cavitary P. carinii pneumonia, pulmonary and hepatic herpes simplex infections, and pulmonary and intestinal cytomegalovirus infection.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The fibroblast-like nature of myofibroblasts.

The myofibroblast is found in normal tissue as well as in a wide variety of pathological processes. We have cultured myofibroblasts and dermal fibroblasts and have found that they secrete similar type-specific procollagens into the culture media. These were primarily type I and III procollagens with a predominance of type I procollagen. These patterns are distinctly different from those of smooth muscle cells, which synthesize predominantly type III procollagen. Cultured fixed cells were also examined by immunohistochemistry. Both myofibroblasts and fibroblasts stained positively with antibodies to type I and III procollagens. Reaction to type V procollagen antibodies was prominent only in the myofibroblast, as was immunostaining with anti-muscle actin antibodies. Immunostaining with desmin antibodies was negative in both cell types. By electron microscopy, the myofibroblast had well-developed dense microfilament fibers of 40-80 degrees that were prominent in the long axes of the cells near the cellular margins. Although the myofibroblast has properties of both smooth muscle cells and fibroblasts, it appears to be most likely a modified fibroblast that has undergone differentiation, probably in response to specific signals from the extracellular matrix.

Actins↗