Expression of Notch in a case of osteosarcoma of the maxilla.

In this immunohistochemical examination, the expression of Notch1 peptide was detected in neoplastic cells in a case of osteosarcoma of the maxilla of a 31-year-old Indonesian male patient. Notch1 peptide appeared in the cytoplasm of neoplastic cells of comparatively well-differentiated areas of the osteosarcoma, an osteoblastic area containing osteoid and/or immature bone tissues. The results suggest that Notch1 is closely related to cytological differentiation or acquisition of cytological characteristics in neoplastic cells of osteosarcoma.

Various immunostaining patterns of CD31, CD34 and endoglin and their relationship with lymph node metastasis in oral squamous cell carcinomas.

Background: Intratumoral blood vessels are known to play an important role in cancer growth and metastasis. The discrepancy in previous reports using various endothelial markers individually suggested us to investigate both normal and various tumor areas with a wide panel of vascular markers.

Methods: Here, we used a panel of three antibodies (CD31, CD34, and endoglin) as blood vessel markers to investigate the distribution and properties of blood vessels in normal oral tissues and squamous cell carcinomas.

Heparanase expression correlates with malignant potential in human colon cancer.

Purpose: Heparanase cleaves carbohydrate chains of heparan sulphate proteoglycans and is an important component of the extracellular matrix. This study was designed to determine the relation between heparanase expression and prognosis of patients with colon cancer.

Methods: The study included 54 patients (35 males and 19 females) who underwent colorectal resection for colorectal cancer between January 1992 and December 1994.

Genetic and epigenetic alterations of BRG1 promote oral cancer development.

Loss of heterozygosity (LOH) analysis is a sensitive method to detect deletions of specific chromosome regions which are considered to harbor of putative tumor suppressor gene (TSG)s. Previous allelotype analyses in various human cancers suggested the presence of at least one TSG in chromosome 19p13 region. Functional analysis of BRG1, a member of SWI/SNF complex proteins, located at 19p13.

Expression and localization of cartilage-specific matrix protein chondromodulin-I mRNA in salivary pleomorphic adenomas.

Pleomorphic adenoma is the most common epithelial tumor in the salivary glands. This tumor frequently exhibits "mesenchyme"-like components, including myxoid or chondroid areas. Recently, using immunohistochemical techniques, we reported that cartilage-specific matrix protein, chondromodulin-I (ChM-I), was deposited on the inter-territorial matrix of the chondroid area in salivary pleomorphic adenomas and that ChM-I, which is also a strong angio-inhibitory factor, plays an important role in the avascular nature of the chondroid area and the chondroid formation in this type of tumor.

Stable long-term induction of perforin-positive CD8+ T cells in gut by oral administration of streptococcal preparation OK-432.

Perforin is known as a pore-forming cytotoxic granule released from cytotoxic T cells. Previous experiments in vitro revealed the presence of precursor cells that are capable of producing perforin in the immune system cells. The present study was undertaken to examine whether perforin-positive cells could be induced in the digestive tract and to characterize their precursor cells.

In vitro response of osteoblast-like and odontoblast-like cells to unsubstituted and substituted apatites.

Different types of calcium phosphate compounds [calcium-deficient apatite (CDA); beta-tricalcium phosphate (beta-TCP); biphasic calcium phosphate (BCP)] are commercially available for medical and dental applications as bone substitute materials. Most of the reported in vitro studies on cell-material interactions have used osteoblast-like cells. The purpose of this study was to investigate the in vitro response of osteoblast-like (MC3T3-E1) and odontoblast-like (MDPC23) cells on unsubstituted (HA) and substituted (F-substituted) apatites.

Localization of heparanase in esophageal cancer cells: respective roles in prognosis and differentiation.

In this study, we examined the distribution of heparanase protein in 75 esophageal squamous cell carcinomas by immunohistochemistry and analyzed the relationship between heparanase expression and clinicopathological characteristics. In situ hybridization showed that the mRNA expression pattern of heparanase was similar to that of the protein, suggesting that increased expression of the heparanase protein at the invasive front was caused by an increase of heparanase mRNA in tumor cells. Heparanase expression correlated significantly with depth of tumor invasion, lymph node metastasis, tumor node metastasis (TNM) stage and lymphatic invasion.

Influence of CpG island methylation status in O6-methylguanine-DNA methyltransferase expression of oral cancer cell lines.

It is known that the O6-methylguanine-DNA methyltransferase (MGMT) gene is susceptible to epigenetic regulation associated with an altered frequency of CpG methylation. To investigate whether epigenetic regulation of the MGMT gene might lead to significant reductions in the expression levels of cancer cells, we sought evidence of a link between the methylation status of the MGMT promoter and the expression levels of seven human oral cancer cell lines. We found two frequently methylated regions: the 5' region extending from nt 690 to nt 893 in the promoter, and the more 3' region extending from nt 1060 to nt 1151 in the untranslated first exon.

Radiographic examination of dentigerous cysts in the transitional dentition.

Objectives: To examine radiographically the relationship between the deciduous tooth and dentigerous cyst of the permanent successor during the transitional dentition.

Methods: From a retrospective review of all patients who visited our institution from April 1988 to August 2001, 70 patients under 16 years of age who had histologically confirmed dentigerous cysts that had developed from the central incisor to the second premolar were identified. These 70 patients were investigated using panoramic and periapical radiographs.

Gene expression of type I collagen in neoplastic chondrocytes.

In the present examination, we detected type I collagen mRNA in neoplastic chondrocytes in osteochondromas, typical benign bone neoplasms. We believe that the cells involved in >chondroid bone< appearing in osteochondromas temporally express cartilage phenotypes and then change directly into bone-forming cells that survive in the >chondroid bone< until the tissue is resorbed and remodelled into true bone tissue.

Heparanase expression correlates with invasion and poor prognosis in gastric cancers.

Degradation of basement membrane and extracellular matrix structures are important features of the metastatic process of malignant tumors. Human heparanase degrades heparan sulfate proteoglycans, which represent the main components of basement membranes and the extracellular matrix. Because of the role of heparanase in tumor invasion and metastasis, we examined heparanase expression in primary gastric cancers and in cell lines derived from gastric cancers by immunohistochemistry and RT-PCR, respectively.

Mastoid obliteration by BMP-2/collagen composites: an experimental study using tissue engineering.

Purpose: Several materials have been used in the application of mastoid cavity obliteration during surgery for cholesteatoma; however, nothing has won universal acceptance. Through the advancement of tissue engineering, bone morphogenetic protein-2 (BMP-2)/collagen composites have been elucidated as inducers of heterogenic bone formation. This study was performed to investigate whether these composites are potentially obliteration materials for use in the mastoid cavity by using an animal experimental study.

Angioarchitecture of primary oral malignant melanomas.

Angiogenesis is an essential process in the progression of malignant tumors. However, little is known of the angioarchitecture in primary oral malignant melanoma. We sought to determine this by the use of periodic acid-Schiff (PAS) stain, endothelial markers (CD34, CD105) and laminin, and by transmission electron microscopy in two cases.

Differential expression of collagen IV alpha1 to alpha6 chains in basement membranes of benign and malignant odontogenic tumors.

Type IV collagen, the major component of basement membrane (BM), demonstrates a stage- and position-specific distribution of its isoforms during tooth development. To determine its localization in BM of odontogenic neoplasms, immunohistochemistry using six anti-alpha(IV) chain-specific monoclonal antibodies was performed. Results disclosed that BM demonstrated an irregular alpha(IV) chain profile in malignant odontogenic tumors as compared to benign odontogenic neoplasms.

Distribution of basement membrane type IV collagen alpha chains in ameloblastoma: an immunofluorescence study.

Background: Type IV collagen, a heterotrimeric molecule that exists in six genetically distinct forms, alpha1(IV)-alpha6(IV) is a major structural component of basement membrane (BM) and acts as a scaffold for other BM constituents.

Methods: Indirect immunofluorescence using alpha chain-specific monoclonal antibodies was employed to clarify basement membrane (BM) collagen IV distribution in two ameloblastoma, and for comparison, on oral mucosa and tooth germ.

Results: Ameloblastoma BM expressed five of six genetically distinct forms of collagen IV: alpha1(IV), alpha2(IV), alpha5(IV) and alpha6(IV) chains occurred as intense linear stainings without disruption around neoplastic epithelium, and this expression pattern was fundamentally similar to oral mucosa BM; alpha4(IV) expression was rare and occurred around nests of primitive tumor cells or potentially invasive sites.

Elemental sulphur and alkali elutable melanin detected in oral melanosis and malignant melanoma by energy-filtering transmission electron microscopy.

Background: The morphology and contents of melanosomes are important features for differentiating melanocyte-derived melanotic lesions such as melanosis and malignant melanoma.

Methods: In this study, we attempted to elucidate the structure of melanin and sulphur content in oral melanosis and malignant melanomas by ultrastructural analysis.

Results: In oral melanosis, the essential pathological findings were overproduction of eumelanin and discharge of melanin into keratinocytes.

The expression of dentin sialophosphoprotein gene in bone.

Dentin sialoprotein (DSP) and dentin phosphoprotein (DPP) are expressed as a single mRNA transcript coding for a large precursor protein termed dentin sialophosphoprotein (DSPP). DSP, DPP, and DSPP have been considered to be tooth-specific. To test for the expression of the dspp gene in bone, we performed Western immunoblots and reverse-transcription polymerase chain-reaction (RT-PCR).

Expression of type I, type II, and type X collagen genes during altered endochondral ossification in the femoral epiphysis of osteosclerotic (oc/oc) mice.

The osteosclerotic (oc/oc) mouse, a genetically distinct murine mutation that has a functional defect in its osteoclasts, also has rickets and shows an altered endochondral ossification in the epiphyseal growth plate. The disorder is morphologically characterized by an abnormal extension of hypertrophic cartilage at 10 days after birth, which is later (21 days after birth) incorporated into the metaphyseal woven bone without breakdown of the cartilage matrix following vascular invasion of chondrocyte lacunae. In situ hybridization revealed that the extending hypertrophic chondrocytes expressed type I and type II collagen mRNA, as well as that of type X collagen and that the osteoblasts in the metaphysis expressed type II and type X collagen mRNA, in addition to type I collagen mRNA.

Usefulness as guided bone regeneration membrane of the alginate membrane.

Alginate membrane is a new bioabsorbable, guided bone regeneration (GBR) membrane, which is placed directly on the surface of the bone defect. It is designed to drop a calcium chloride aqueous solution into the bone defect, which is filled with sodium alginate aqueous solution. Alginate membrane is an excellent agent for this procedure due to its close assimilation to the surface of the bone.

Characteristics of bone morphogenetic protein-induced chondroid bone: histochemical, immunohistochemical and in situ hybridization examinations.

The third ossification mode, known as transchondroid bone formation, is displayed chiefly in the bone morphogenetic protein (BMP)-induced heterotopic bone formation model. This paper describes the results of histopathological, histochemical, immunohistochemical, and in situ hybridization examinations of BMP-induced heterotopic bone in mice. The research focuses on the localization of typical matrix proteins (peptide and its mRNA) of cartilage and bone--type-I and type-II collagen, osteocalcin and osteopontin--in the chondroid bone matrix.

Localization of type IV collagen a 1 to a 6 chains in basement membrane during mouse molar germ development.

The dental basement membrane (BM) putatively mediates epithelial-mesenchymal interactions during tooth morphogenesis and cytodifferentiation. Type IV collagen alpha chains, a major network-forming protein of the dental BM, was studied and results disclosed distinct expression patterns at different stages of mouse molar germ development. At the dental placode and bud stage, the BM of the oral epithelium expressed alpha 1, alpha 2, alpha 5 and alpha 6 chains while the gubernaculum dentis, in addition to the above four chains, also expressed a 4 chain.

Quantitation of epidermal growth factor receptor gene amplification by competitive polymerase chain reaction in pre-malignant and malignant oral epithelial lesions.

Abnormal amplification of epidermal growth factor receptor (EGFR) gene has been reported widely in various human tumors. However, the status of amplification of this gene in the process of carcinogenesis is not clearly defined. We used competitive polymerase chain reaction (PCR) to study whether EGFR gene is amplified and the degree of amplification in pre-malignant and malignant oral epithelial lesions, and also examined the relationship between EGFR gene aberration and the development of squamous cell carcinoma (SCC).

Human alpha-and beta-defensin immunoreactivity in oral mucoepidermoid carcinomas.

The purpose of this study was to demonstrate the immunohistochemical localization and distribution of human alpha- and beta-defensins, peptides with antimicrobial activity, in oral mucoepidermoid carcinoma tissue. Tissue samples were embedded in paraffin and alpha- and beta-defensins were immunostained by the streptavidin-biotin coupled peroxidase method. Cancer cells that constituted the ducts, as well as neutrophils, were positively immunostained with the anti-alpha-defensin antibody (HNPs).

Novel asymmetric oxy-michael addition reaction of the chiral ketones to the achiral gamma--or delta-hydroxy-alpha,beta-unsaturated carbonyl compounds.

A novel asymmetric oxy-Michael addition reaction was developed. In the presence of a catalytic amount of base, chiral ketones 1 and 2, derived from D-glucose and D-fructose, respectively, reacted with omega-hydroxy enones or enoates 3a-e, 17 and 21 to form the hemiacetal-derived alkoxide which underwent stereoselective intramolecular Michael addition to give cyclic acetals. Although the stereoselectivities in the formation of the five-membered acetal rings were modest, six-membered ring formation proceeded with high stereoselectivity and the utility of the reaction was demonstrated by a simple syntheses of natural products.