Polyamine contents in rectal and buccal mucosae in humans treated with oral difluoromethylornithine. (33/260)

Difluoromethylornithine (DFMO) is an investigational chemopreventive agent that inhibits ornithine decarboxylase (ODC) activity, lowers cellular polyamine concentrations, and decreases cell proliferation in vivo and in vitro. In five subjects we have compared the polyamine concentrations in rectal mucosal biopsies and in exfoliated buccal mucosal cells (EBM) before and after DFMO treatment to assess the suitability of EBM as an easily accessible marker tissue for DFMO suppression of polyamine synthesis in the rectal mucosa. One month of 3 g/m2/day of DFMO treatment caused a statistically significant decrease in putrescine and spermidine concentrations in rectal mucosa biopsy specimens but not in EBM samples. ODC activity in EBM was high (approximately 1 mumol/min/mg protein), resistant to DFMO inhibition (Ki = 4200 microM), dependent on GTP concentration (maximal at 0.1 mM), and was reduced concomitantly with bacterial concentration by antiseptic mouthwashing. Bacteria adherent to EBM were visible by electron microscopy. Forty bacterial colonies/ng protein were culturable from washed EBM samples. Oral bacteria preclude the use of EBM samples as a marker tissue of DFMO effect in the rectal mucosa, but oral DFMO therapy is effective in depleting polyamines in rectal mucosa.  (+info)

Evaluation of an oral preventive protocol in children with acute lymphoblastic leukemia. (34/260)

This study was designed to assess the effectiveness of a preventive oral protocol in children receiving antineoplastic treatment for acute lymphoblastic leukemia (ALL) before initiating a larger intervention study. During a seven month period, fourteen children from two to ten years old with a diagnosis of ALL were evaluated. Patients with ALL who received a 0.12% chlorhexidine mouth rinse (seven children) were compared to a control group of patients who were not given the same preventive treatment (seven children) as to the occurrence of oral mucosal complications. Children in both groups received daily oral hygiene care, and were examined daily by the pediatric dentistry team until discharge. A significant decrease in the incidence of oral mucositis and ulceration was observed in the children who received a 0.12% chlorhexidine mouth rinse (p < 0.05 by Fisher's exact test). The findings obtained in the present trial are encouraging, and suggest that the systematic application of a preventive protocol reduces the incidence of oral complications in children with ALL receiving chemotherapy.  (+info)

An attenuated adenovirus, ONYX-015, as mouthwash therapy for premalignant oral dysplasia. (35/260)

PURPOSE: Dysplastic lesions of the oral epithelium are known precursors of oral cancer. A significant proportion of oral dysplastic lesions have functional defects in p53 response pathways. The ONYX-015 adenovirus is selectively cytotoxic to cells carrying defects in p53-dependent signaling pathways. The current study sought to establish the feasibility and activity of ONYX-015 administered topically as a mouthwash to patients with clinically apparent and histologically dysplastic lesions of the oral mucosa. PATIENTS AND METHODS: A total of 22 patients (19 assessable patients) were enrolled onto the study. ONYX-015 was administered on three different schedules to consecutive cohorts. Biopsies of the involved mucosa were performed to evaluate histologic response and changes in expression of putative markers of malignant potential, including p53, cyclin D1, and Ki-67. Serology was performed to measure antiadenoviral titers. RESULTS: Histologic resolution of dysplasia was seen in seven (37%) of 19 patients, and the grade of dysplasia improved in one additional patient. The majority of responses were transient. No toxicity greater than grade 2 (febrile episode in one patient) was observed. Only one of seven patients demonstrated an increase in circulating antiadenoviral antibody titer while on therapy. Although responding and resistant lesions had similar mean p53 staining at baseline, histologic response correlated with a decrease in p53 positivity over time. Significant changes in cyclin D1 or Ki-67 were not observed. Viral replication was confirmed in two of three lesions examined. CONCLUSION: This novel approach to cancer prevention is tolerable, feasible, and has demonstrable activity.  (+info)

Effect of a 0.5% chlorhexidine gel on dental plaque superinfecting microorganisms in mentally handicapped patients. (36/260)

A randomized clinical trial was conducted to investigate the effect of a 0.5% chlorhexidine (CHX) gel on dental plaque superinfecting microorganisms in mentally handicapped patients. Thirty inmates from the institution "Casas Andre Luiz" were assigned to either test group (CHX gel, n = 15) or control group (placebo gel, n = 15). The gel was administered over a period of 8 weeks. Supragingival plaque samples were collected at baseline, after gel use (8 weeks) and 16 weeks after baseline. The presence of Gram-negative Enterobacteriaceae, Staphylococcus and yeasts was evaluated. No significant growth of any superinfecting microorganism was observed in the CHX group, when compared to the placebo group. The results indicated that the 0.5% chlorhexidine gel did not produce an undesirable shift in these bacterial populations.  (+info)

Alcohol-containing mouthwashes and oral cancer. Critical analysis of literature. (37/260)

For centuries, mouthwashes have been used in order to provide us with oral health or cosmetic benefits. Nowadays, in most countries, there is a variety of formulas available for the general public in the form of products which may require prescription or not. Alcohol is used in mouthwashes as a solvent of other ingredients and as a preservative of the preparation. For years, different formulas of mouthwashes have been used, however, the question about its alcohol content being a threat for health or not has recently appeared. The high quantity of alcohol in some mouthwashes combined with the fact that they keep in contact with the oral mucosa for much more time than alcoholic drinks, can make us think about a harmful effect from a local mechanism. Mouthrinses increase the time of the mucosa being in contact with alcohol and it has been proved that those with a high content of alcohol do cause hyperkerastosic lesions both in human beings and laboratory animals. At the moment and with the data we have, it has not been possible to establish a causal relationship between the use of alcohol-containing mouthwashes and the development of oral cancer. There is neither an evidence of the fact that alcohol increases the effects of antiplaque agents in mouthwashes.  (+info)

Randomized, double-blind, placebo-controlled phase IIb trial of the cyclooxygenase inhibitor ketorolac as an oral rinse in oropharyngeal leukoplakia. (38/260)

PURPOSE: Nonselective cyclooxygenase (COX) inhibitors have been reported to decrease the frequency of upper aerodigestive cancers. Ketorolac tromethamine oral rinse has been shown to resolve another COX-dependent process, periodontal disease, without incurring gastrointestinal side effects. This trial evaluated if a topically delivered oral rinse containing ketorolac was as safe as and more effective than oral rinse alone in reducing the area of oral leukoplakia. EXPERIMENTAL DESIGN: 57 patients were randomized (2:1 ratio) in a double-blind, placebo-controlled study of ketorolac (10 ml of a 0.1% ketorolac rinse solution; n = 38) or placebo (10 ml of rinse solution; n = 19) given twice daily for 30 s over 90 days. Primary end point was evaluated visually obtaining bidimensional measurement of the size of leukoplakia lesion(s) at entry and at 90 days. Secondary end point was histological assessment of the leukoplakia as sampled by serial punch biopsy and independently reviewed by three pathologists. RESULTS: The patients included 67% males, 11% non-Caucasian, and 86% used tobacco with no significant differences between the two arms. Both rinses were well tolerated with good compliance, and there was no significant difference in adverse events (P = 0.27). Major response rate (complete response and partial response) was 30% for ketorolac and 32% for the placebo arm. There was no significant difference in change in histology between the two arms. CONCLUSION: Local delivery of a COX-containing oral rinse was well tolerated but produced no significant reduction in the extent of leukoplakia compared with the placebo. However, the favorable response rate to placebo arm remains unexplained and additional investigation of the tissue penetration with ketorolac is warranted.  (+info)

Selection for high-level resistance by chronic triclosan exposure is not universal. (39/260)

OBJECTIVES: To investigate the effect of triclosan exposure on the antimicrobial susceptibilities of numerically important dental bacteria. METHODS: A gradient plate technique was used to expose Fusobacterium nucleatum, Lactobacillus rhamnosus, Neisseria subflava, Porphyromonas gingivalis, Actinomyces naeslundii, Prevotella nigrescens, Streptococcus oralis, Streptococcus sanguis, Streptococcus mutans and Veillonella dispar repeatedly to escalating, sublethal concentrations of triclosan. Escherichia coli ATCC 8739 was included as an organism showing the triclosan resistance development trait. MIC values towards chlorhexidine, metronidazole and tetracycline were determined before and after biocide exposure. RESULTS: N. subflava, Pr. nigrescens Po. gingivalis and E. coli were highly susceptible to triclosan (MIC range 0.1-3.9 mg/L), whereas the lactobacillus and S. mutans were less susceptible (MIC range 15.6-20.8 mg/L). Triclosan exposure resulted in a highly significant ( approximately 400-fold) reduction in triclosan susceptibility (P < 0.01) for the positive control E. coli, although its MICs towards chlorhexidine, metronidazole and tetracycline were not significantly altered. Minor ( approximately two-fold) decreases in triclosan susceptibility (MIC) occurred for Pr. nigrescens and in S. sanguis and S. oralis (MBC). Mean changes in susceptibilities (MIC and MBC) of the oral species to chlorhexidine, metronidazole and tetracycline did not exceed two-fold, although chlorhexidine MBCs for S. sanguis were markedly, but transiently, increased. CONCLUSIONS: These data fail to demonstrate biologically significant drug resistance in triclosan-exposed bacteria and suggest that markedly decreased triclosan susceptibility, although confirmed for E. coli, is not a universal phenomenon. Other bacteria possibly possess more susceptible targets than FabI that are highly conserved, which may govern triclosan activity.  (+info)

In vitro activities of iodonium salts against oral and dental anaerobes. (40/260)

The comparative in vitro activities of 11 iodonium salt compounds, 0.12% chlorhexidine, and four antimicrobial agents against 322 anaerobic and fastidious potential dental and periodontal bacterial pathogens were studied. Iodonium salts 3, 4, 5, 9, and 10 had in vitro activities comparable to that of chlorhexidine against most isolates. These compounds may be suitable for incorporation into an oral mouthwash.  (+info)