11q13 amplification status and human papillomavirus in relation to p16 expression defines two distinct etiologies of head and neck tumours.

Two distinct etiologies of head and neck squamous cell carcinoma (HNSCC) have been proposed, DNA damage owing to tobacco and alcohol exposure and human papillomavirus (HPV) oncogene-mediated transformation. Common genetic alterations in HNSCC include TP53 mutations, 11q13 amplification (amp) and CDKN2A/p16 mutations or promoter methlyation. However, in HPV+ HNSCC it is frequent to observe wild-type TP53 and expression of p16. The relationship of this unusual pattern with 11q13 amp has not been tested. In a retrospective study on 125 HNSCC patients, only 17% (five out of 30) of HPV+ vs 44% (39 out of 89) of HPV - tumours expressed 11q13 amp (adjusted odds ratio (OR)=0.2, 95% confidence interval (CI)=0.1-0.6). A subpopulation of tumours (n=69) were classified according to the three molecular markers, TP53, p16 and 11q13 amp. In addition to wild-type TP53, and p16 expression, HPV+ tumours were more likely not to be amplified at 11q13 (OR=6.5, 95% CI=1.8-23.9). As HPV+ HNSCC lack the genetic alterations which are common in other tumours, we hypothesise that HPV infection may represent an early event in the HNSCC carcinogenic process, thus suggesting a distinct molecular pathway.

Reliability of self-reported heart murmur history: possible impact on antibiotic use in dentistry.

Administration of prophylactic antibiotics to a dental patient with a history of heart murmur, rheumatic fever or mitral valve prolapse should be based on a reliable diagnosis of heart valve disease. The authors conducted a study of 68 diabetic patients who reported having these conditions and found that at least 65 percent of these patients actually had no evidence of a pathological heart murmur during two previous physical examinations. They concluded that a self-reported history of heart valve disease should not be the sole criterion for antibiotic premedication.

Microsatellite instability in oral cancer.

Generalized genomic instability, detected as somatic changes in allele sizes at microsatellite loci in tumors compared to peripheral lymphocyte DNA, is a recently recognized mechanism of mutation in cancer. Such instability results from the somatic loss of DNA mismatch repair capability. Germ-line mutations at DNA mismatch repair loci confer susceptibility to colon cancer in hereditary non-polyposis colorectal cancer. Somatic loss of DNA mismatch repair has been reported in a large variety of other tumor types. Our goal was to determine the frequency of microsatellite instability in a large series of oral tumors. Out of 91 tumors analyzed for microsatellite instability, 6 (7%) showed microsatellite instability. Instability was observed at multiple loci with a range of 50-74% of loci affected. Alterations include both increase (74%) and decrease (26%) in allele sizes. The proportion of alleles affected ranged from 30-58% of all alleles. Our data suggest that somatic genomic instability plays a role in the pathogenesis of a small subset of oral tumors.

Visualization of INT2 and HST1 amplification in oral squamous cell carcinomas.

Oral squamous cell carcinoma (OSCC) develops along a multistep genetic pathway including loss of tumor suppressor genes and alteration of oncogenes. We characterized seven OSCC cell lines by classical and molecular cytogenetic analysis and fresh tumor and adjacent oral mucosa corresponding to three of the cell lines by molecular cytogenetics. We observed homogeneously staining regions (hsrs) in four of the seven cell lines, at 11q13 in three and at 11q23 and in an unidentified marker chromosome in the fourth. Amplification of band 11q13 occurs in 30-60% of head and neck squamous cell carcinomas. To determine whether INT2 and HST1, both located in band 11q13, are amplified in the tissues and cell lines and to confirm the chromosomal location(s) of the amplification, we used dual-color fluorescence in situ hybridization (FISH) with DNA probes for these genes and the chromosome 11 centromere. We report chromosomal localization of INT2/HST1 amplification in OSCC. Coamplification of INT2 and HST1 was detected in the hsrs in cultured tumor cells from the four hsr-containing tumors and in directly harvested tumor cells, which were available from only two of these tumors. Amplification was not present in tumors lacking hsrs or adjacent oral mucosa corresponding to any of the seven tumors. The observation of amplification in fresh tumor cells suggests that the amplification was present in the patients, may play a key role in the development and/or progression of OSCC, and is not due to karyotypic evolution in vitro. The absence of amplification in the adjacent mucosa suggests that 11q13 amplification is a relatively late event in OSCC tumorigenesis.

A monoclonal antibody recognizing Golgi apparatus produced using affinity purified material from a patient with connective tissue disease.

Serum antibodies recognizing the Golgi apparatus have been reported in patients with connective tissue diseases, but little is known of their significance. Serum from a systemic lupus erythematosus patient with polymyositis was found to have high titers of anti-Golgi apparatus antibody. This serum recognized a 64 kD polypeptide in immunoblotting with HEp-2 cells. To verify that the 64 kD polypeptide was associated with the Golgi apparatus and to characterize which Golgi component was recognized, a monoclonal antibody was produced. IgG, isolated from this serum, was used in affinity chromatography to produce purified material which was used to generate a mouse monoclonal antibody. The monoclonal antibody had an indirect immunofluorescent pattern identical to that produced by the patient's serum, and similarly recognized a 64kD polypeptide in immunoblotting. A 59 kD polypeptide was also recognized by the monoclonal antibody, suggesting that the antigens recognized by the monoclonal and serum antibodies may be only partially identical. The antigen appears to be a glycoprotein and an integral component of the Golgi cisternae membranes.

Thermally induced 'nicotine' stomatitis. A case report.

A palatal lesion resembling "nicotine" stomatitis was found in a woman who did not smoke. However, the patient frequently drank extremely hot beverages. After she was instructed to reduce the temperature of the beverages, the lesion almost completely resolved. This suggests that heat was the primary cause of this lesion and also implicates heat as the major cause of nicotine stomatitis.

Odontodysplasia in a pediatric patient: literature review and case report.

A case of a three-year-old Caucasian male with odontodysplasia is presented. Although the etiology of this condition is unknown, this anomaly involves both the mesodermal and ectodermal dental components and results in deficient and abnormal formation of dentin and enamel. The orofacial characteristics and dental findings of the condition are presented in this case report.

Graft-versus-host disease and sialodacryoadenitis viral infection in bone marrow transplanted rats.

The effect of a localized viral infection on the occurrence of graft-vs.-host disease (GVHD) was examined in allogeneic rat bone marrow chimeras (ACI/LEW). Animals without clinical evidence of GVHD, 62 days after bone marrow transplant, were infected in salivary and lacrimal glands with sialodacryoadenitis virus (SDAV), and sacrificed 8-25 days postinfection. Using established histologic criteria, GVHD was found more frequently in salivary and lacrimal glands of SDAV-infected chimeras than uninfected chimeras. Skin and oral mucosa, tissues not infected by the virus, showed no differences in occurrence of GVHD, suggesting that the viral infection induced only local and not systemic GVHD. GVHD and SDAV infection, which are histologically similar, were differentiated by examining tissues for SDAV antigen using immunoperoxidase technique. Histologic changes were present for at least 1 week longer than viral antigen, suggesting they represented GVHD rather than viral infection. GVHD and SDAV infection were also differentiated by looking for a histologic feature characteristic of GVHD and not found in SDAV infection (periductal lymphocytic infiltrate). This was found in SDAV-infected chimeras more frequently than uninfected chimeras, suggesting that the viral infection somehow induced GVHD. Results showed a localized increase in the occurrence of GVHD subsequent to localized viral infection.

Resolution of candidal lesions of the dorsal rat tongue by ketoconazole.

The purpose of this study was to determine whether the mucosal alterations of the dorsal rat tongue produced by Candida albicans infection were reversible upon treatment with the antifungal drug ketoconazole. Following experimentally-produced infection, 17 rats showed clinical evidence of persistent lesions over a period of 20 weeks. Eight of these animals were then treated with ketoconazole daily for 2 weeks (20 mg/kg/day). Appropriate non-infected controls and ketoconazole-only controls were also maintained. Five weeks after the ketoconazole treatment, all animals were killed and the dorsal tongues evaluated clinically and histologically. Control groups showed no abnormalities. Of the 8 animals in the treated-lesion group, all showed lesional resolution, while only 2 of the 9 animals in the untreated-lesion group showed resolution of their lesions (p = 0.002). These findings indicate that the epithelial changes produced by this candidal isolate for this period of time are reversible.

Influence of radiation therapy on oral Candida albicans colonization: a quantitative assessment.

An increase in quantity of oral Candida albicans was documented in patients receiving head and neck radiation therapy during and after therapy, as assessed by an oral-rinse culturing technique. The amount of the increase was greater in denture wearers and directly related to increasing radiation dose and increasing volume of parotid gland included in the radiation portal. A significant number of patients who did not carry C. albicans prior to radiation therapy developed positive cultures by 1 month after radiation therapy. The percentage of patients receiving head and neck radiation therapy who carried C. albicans prior to radiation therapy did not differ significantly from matched dental patient controls.

Necrotizing sialometaplasia: a case with metachronous lesions.

A case of two episodes of necrotizing sialometaplasia occurring metachronously in a single patient has been reported. The clinical and histologic features of these lesions are described and discussed in relation to the spectrum of presentations of the condition.

Relation of stress and anxiety to oral lichen planus.

Stress and anxiety have frequently been mentioned as possible factors related to the development of oral lichen planus, although this association appears to have only an anecdotal origin. In this study, 48 patients with a clinical and histologic diagnosis of oral lichen planus completed questionnaires aimed at assessing their stressful life events (Social Readjustment Rating Scale) and their tendency for anxiety (the trait portion of the State-Trait Anxiety Inventory). Age- and sex-matched control groups included patients who underwent biopsies for irritation fibroma and routine clinic patients. No significant differences were seen among any of the groups with respect to scores on the questionnaires. These results suggest that patients who manifest oral lichen planus have no greater tendency toward anxiety and no more stressful life events than other individuals.