Biostimulatory effects of laser irradiation on cell proliferation and wound healing has been reported. However, little is known about the molecular basis of the mechanism. Interleukin 1beta (IL-1beta), tumor necrotic factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) play an important role in inflammation, while platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-beta) and blood-derived fibroblast growth factor (bFGF) are the most important growth factors of periodontal tissues. The aim of this study was to investigate the effect of low-level He-Ne laser on the gene expression of these mediators in rats' gingiva and mucosal tissues. Twenty male Wistar rats were randomly assigned into four groups (A(24), A(48), B(24), B(48)) in which A(24) and A(48) were cases and B(24), B(48) were controls. An incision was made on gingiva and mucosa of the labial surface of the rats' mandibular incisors. Group A(24) was irradiated twice with 24 hours interval, while the inflamed tissues of group A(48) was irradiated three times with continuous He-Ne laser (632.8 nm) at a dose of 7.5 J/cm2 for 300 s. An energy of 5.1 J was given to the 68 mm(2) irradiation zone. Rats were killed 30 min after the last irradiation of case and control groups, then excisional biopsy was performed. Gene expression of the cytokines was measured using reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Results were analyzed with Kruskal-Wallis and Mann-Whitney U tests. The gene expression of IL-1beta and IFN-gamma was significantly inhibited in the test groups (P < 0.05), while the gene expression of PDGF and TGF-beta were significantly increased (P < 0.05). The case and control groups did not have a significant difference in the gene expression of TNF-alpha and bFGF (P > 0.05). These findings suggest that low-level He-Ne laser irradiation decreases the amount of inflammation and accelerates the wound healing process by changing the expression of genes responsible for the production of inflammatory cytokines.

No abstract

The purpose of this study was to analyze the 5-year survival rates of 82 patients with lip cancer attending 5 university hospitals during 1999-2003 in Tehran, Iran. We used information from patient records, telephone calls, and death register files of the Iran Ministry of Health to ascertain the patients' vital status. Associations between survival and the variables of sex, age, stage of the tumor at the time of diagnosis, treatment modality, and tumor histopathologic type were analyzed with Kaplan-Meier, log-rank, and Cox regression methods. Of all patients, 70 (85%) were men, with a median age of 62 years (mean, 58.6 years [SD, 15 years]; range, 27-85 years) at the time of diagnosis. The median follow-up time of the patients was 57 months (mean, 56.4 months [SD, 28 months]; range, 0-112 months). The 1- to 5-year overall survival rate was 91% to 62%. The tumor stage at the time of diagnosis and the treatment modality were associated with survival (P < 0.05) in both univariate and multivariable analyses. Patients who underwent surgery and had lower stage tumors at the time of diagnosis showed higher survival rates. No differences in patient survival were found regarding sex, age, and histopathologic type of tumors. These findings indicate that although lip tumors are curable, early detection, diagnosis, and treatment lead to even higher rates of survival. Importance of the early detection of lip cancer should be emphasized in all health care and cancer prevention campaigns directed to the public and professionals.

This study analyzed characteristics of oral cancer patients from Tehran, Iran, and their tumors. Data came from the patient records of 30 major hospitals in Tehran. Patients (n = 1042), diagnosed with invasive oral cancer in 1993-2003, were classified by primary tumor site according to ICD-10 (C00-C10). Data were analyzed separately for lip, oral cavity and salivary gland tumors. Statistical evaluation included chi and t-test. Of all cases, 59% were male. Age for all cases ranged from 6-103 years, mean age was 58.8 years (SD 16; median 62); 89% were older than 40. Tumor site breakdown was 65% oral cavity, 21% major salivary glands and 14% lip. A clear gender difference (P < 0.001) appeared regarding the primary tumor sites: women dominated in oral cavity cancers and men in lip cancers. The most common cancer site was the tongue (32%), accounting for 50% of the oral cavity cancers. Histologically, 88% of all oral cavity and lip cancers were squamous cell carcinomas, 10% of those were in age /= age 65. At the time of diagnosis, 59% of oral cavity cancers and 29% of lip cancers were at stage III or IV (P < 0.001). The results emphasize an urgent need for a national program focusing on early detection of oral cancers, including educational information addressed to oral health professionals.