Ameloblastomatoid, central odontogenic fibroma: an epithelium-rich variant.

Two cases are presented of a central odontogenic fibroma (OF) in the mandible of a middle-aged female, which posed considerable difficulty in microscopic diagnosis. These well-demarcated but non-encapsulated intraosseous tumors had hybrid features of both OF and ameloblastoma. Their clinical findings are more in keeping with the putative OF rather than ameloblastoma.

Prediction of clinical course of diffusely infiltrating astrocytomas from telomerase expression and quantitated activity level.

Telomerase, one of the reverse transcriptases that extend telomere length, has been suggested to facilitate tumorigenesis and tumor immortality. Little is yet known, however, concerning the clinical significance of telomerase expression in brain tumors. We found in the present study that telomerase expression may contribute to malignant progression and can be an important indicator of high grade diffusely infiltrating astrocytomas, and its quantitated activity level reflects their growth potential.

Endovascular papillary hemangioma of the lip.

We present a previously undescribed, intravenously occurring papillary hemangioma of the lip in a 10-year-old girl. Maze-like anastomosing capillary loops were found within the numerous, dilated veins widely distributed in the submucosa. These peculiar endovascular papillae of bland endothelial cells plugged the lumens and bore a striking resemblance to the renal glomeruli.

Compound odontoma with granular cells.

The authors present an interesting and unusual histology of compound odontoma from an 18-year-old female. Part of the subepithelial connective tissue beneath the enamel organ epithelium was replaced by a granular cell nodule, of a probable histiocytic nature. This case represents the first published report of odontoma accompanied by granular cells.

Dendritic cells in human squamous cell carcinoma of the oral cavity.

Dendritic cells (DCs) are antigen-presenting cells that initiate and modulate immune responses, including tumor immunity. In this study we examined, immunohistochemically, the distribution of DC subsets in the primary tumor, adjacent tissue and regional lymph nodes (RLNs) of patients with oral squamous cell carcinoma (OSCC). The numbers of S100+ and CD1a+ DCs in tissue adjacent to the primary tumor were greater in patients without metastasis to RLNs (PN- cases), compared with those with metastasis (PN+ cases), while greater numbers of CD83+ DCs in the primary tumors were found in PN+ cases.

Histopathologic reaction of a calcium phosphate cement for alveolar ridge augmentation.

The objective of the present study was to evaluate the feasibility of using a calcium phosphate cement (CPC) in the reconstruction of a defective alveolar ridge in conjunction with implant placement. The CPC consisted of an equimolar amount of tetracalcium phosphate and dicalcium phosphate anhydrous. At the beginning of the experiment, all mandibular premolar teeth of mature beagle dogs were extracted.

Inhibition of chlorogenic acid-induced cytotoxicity by CoCl2.

Chlorogenic acid (CGA) induced apoptotic cell death in human oral squamous cell carcinoma (HSC-2) and salivary gland tumor (HSG) cell lines. CGA exhibited oxidation potential in the culture medium, as demonstrated by NO monitor. Both cytotoxic activity and oxidation potential were significantly reduced by the addition of CoCl2.

Primary intraosseous carcinoma associated with impacted third molar of the mandible: review of the literature and report of a new case.

This study investigated the clincopathologic features of primary intraosseous carcinoma (PIOC) related to the third molar of the mandible. Six cases (5 from the literature and 1 new case; mean patient age 73 years) of PIOC associated with completely impacted lower third molar were analyzed. For comparison, 8 cases of PIOC presenting after extraction of the lower third molar were also evaluated, with a significantly lower mean patient age of 56 years.

Basaloid squamous cell carcinoma of the oral mucosa: a new case and review of 45 cases in the literature.

Basaloid squamous cell carcinoma (BSCC) of the oral mucosa other than the tongue is uncommon. We report a case of a 67-year-old man who diagnosed with Stage I BSCC in the floor of the mouth. This early stage presentation carries a considerably better prognosis.

Delayed recurrence of teratoid cyst 17 years after enucleation.

This report describes a teratoid cyst showing delayed recurrence 17 years after enucleation. A brief discussion concerning disease recurrence is also provided.

Peripheral ameloblastoma with potentially malignant features: report of a case with special regard to its keratin profile.

A peripheral ameloblastoma with atypical features occurring on the left maxillary alveolar ridge of 40-year-old man is described, along with an immunohistochemical profile of its cytokeratin (CK). The lesion apparently originated from the surface gingival epithelium. The tumor nests or strands were highly cellular with a variable degree of squamous differentiation and microcyst formation.

Modification of apoptosis-inducing activity of gallic acid by saliva.

Gallic acid, a structural unit of tannin, induced apoptotic cell death, characterized by nuclear condensation and caspase activation in human oral tumor cell lines (HSC-2, HSG). Agarose gel electrophoresis demonstrated that gallic acid produced large DNA fragments in these cells, as well as in T-cell leukemia (MOLT-4) and erythroleukemia (K-562) cells, whereas it induced internucleosomal DNA fragmentation in human myelogenous leukemic cell lines (HL-60, ML-1, U-937, THP-1). This indicates that induction of internucleosomal DNA fragmentation or production of large DNA fragments depends on both target cells and inducers.

Tumor-specific action of sodium 5,6-benzylidene-L-ascorbate in N-nitrosodiethylamine-administered mouse model.

In order to elucidate the mechanisms of antitumor action of sodium 5,6-benzylidene-L-ascorbate (SBA), we established a mouse hepatocellular carcinoma model by oral administration of N-nitrosodiethylamine (NDA) and examined the ascorbate radical intensity and putrescine content in the liver. The oral intake of NDA induced precancerous lesion and a significant increase in putrescine content among three major polyamines. When the oral intake of NDA was stopped, morphological changes were reversed.

Immunohistochemical detection of cytokeratin 18 and its neo-epitope in Warthin's tumor (adenolymphoma) of the parotid glands.

An immunohistochemical method using a monoclonal antibody M30 (MAb M30), which reacts with the product released by cleavage of cytokeratin 18 (CK18) by activated caspase, was used to investigate the presence and extent of apoptosis in 36 cases of Warthin's tumor (WT) of the parotid glands. The distribution of CK18 in WT was also determined and compared with that of the product detected by MAb M30. In WT, CK18 was observed mainly in the tumor cells of duct-like structures, but not in the cells of lymphatic tissues.

Xeroderma pigmentosum group A gene action as a protection factor against 4-nitroquinoline 1-oxide-induced tongue carcinogenesis.

To test the hypothesis that nucleotide excision repair (NER) plays a protective role in chemical carcinogenesis in internal organs, xeroderma pigmentosum group A gene-deficient (XPA(-/-)) mice, heterozygous (XPA(+/-)) and wild-type (XPA(+/+)) mice were orally administered 0.001% 4-nitroquinoline 1-oxide (4NQO) in their drinking water and compared. After 50 weeks of 4NQO exposure, tongue squamous cell carcinomas (SCCs) occurred in XPA(-/-) mice only, no tumors being observed in XPA(+/-) and XPA(+/+) animals.

Induction of cytotoxicity by chlorogenic acid in human oral tumor cell lines.

Millimolar concentrations of chlorogenic acid (CGA) showed higher cytotoxic activity against human oral squamous cell carcinoma (HSC-2) and salivary gland tumor (HSG) cell lines, as compared with that against human gingival fibroblast (HGF). The cytotoxic activity of CGA was significantly reduced by catalase or CoCl2, but not affected by FeCl3 or CuCl2. ESR spectroscopy showed that higher (millimolar) concentrations of CGA produced radicals under alkaline conditions, acting as a prooxidant, whereas lower concentrations of CGA scavenged superoxide and hydroxyl radical.