Video-assisted superior mediastinal lymphadenectomy for papillary thyroid cancer: a case report.

Superior mediastinal lymph node metastases in papillary thyroid cancer are uncommon. The clinical characteristics and surgical strategy of superior mediastinal lymph node metastases remain unclear. Superior mediastinal lymphadenectomy can be accomplished either by a transcervical or transsternal approach. Transsternal approach for superior mediastinal lymphadenectomy can cause great damage; transcervical approach sometimes results in inadequate exposure. Here we report our experience of a papillary thyroid cancer patient with superior mediastinal lymph node metastases who underwent video-assisted superior mediastinal lymphadenectomy. A 49-year-old woman diagnosed with papillary thyroid cancer in left thyroid underwent unilateral lobectomy and ipsilateral central and lateral node dissection in the local hospital 4 years ago. Currently lymph node metastases were found in mediastinum and the right neck, some of which were adjacent to the right innominate vein. Unilateral lobectomy, ipsilateral central and lateral node dissection, and video-assisted superior mediastinal lymphadenectomy were successfully performed by transcervical approach. Subsequently, the patient received thyroxine suppression therapy and adjuvant radioiodine treatment. Video-assisted superior mediastinal lymphadenectomy, providing adequate exposure for a complete superior mediastinal lymphadenectomy, is proved to be safe and feasible.

[Bushen Huatan recipe for treatment of polycystic ovary syndrome: therapeutic mechanism based on network pharmacology and molecular docking].

OBJECTIVE: To explore the pharmacological mechanism of Bushen Huatan (BSHT) recipe in the treatment of polycystic ovary syndrome (PCOS). METHODS: The active ingredients in the component drugs of the recipe were screened through TCMSP, and their potential targets were predicted by PubChem and Swiss target prediction. Genecards and OMIM were used to screen the therapeutic targets in the treatment of PCOS. The drug targets and disease targets were corrected using Uniprot, and the intersection targets were obtained. The protein-protein interaction (PPI) network was constructed using STRING, and the intersection targets were analyzed with CytoNCA to screen the core targets. DAVID was used for GO enrichment analysis and KEGG pathway enrichment analysis, and the core components and core targets were verified using AutoDock. Animal experiment was performed to verify the results using a female C57BL/6J mouse model of PCOS, treated daily with 1 mg/kg BSHT recipe granule for 35 days, and the ovarian expressions of the core targets and pathways were detected using Western blotting. RESULTS: We identified a total of 125 potential active ingredients from the 14 component drugs in the recipe, 990 drug targets, 4759 PCOS targets and 434 intersection targets. The core active ingredients of the recipe included ß -Sitosterol, kaempferol, and quercetin, whose core targets included PIK3CA, PIK3R1, APP, AKT1, and MAPK1. GO enrichment analysis highlighted such processes as drug reaction, negative regulation of apoptosis, and positive regulation of transcription from RNA polymerase Ⅱ promoter. The enriched KEGG pathways included primarily the cancer pathway and PI3K-Akt signaling pathway. Molecular docking showed that the core active ingredients had strong binding ability with the core targets. In the animal experiment, BSHT recipe was shown to improve the symptoms, down-regulate the expressions of PI3K and Akt proteins and up-regulate MAPK1 expression in the ovary of mice with PCOS. CONCLUSION: The therapeutic mechanism of BSHT recipe for PCOS involves multiple active ingredients, multiple therapeutic targets and multiple pathways.

Metabolic Disorders and Mineral Density of the Bone Tissue in the Early Pathogenesis of Osteonecrosis: Study on Rabbits with Steroid-Induced Osteonecrosis.

The relationship between the appearance of bone metabolism disorders and the onset of steroid-induced osteonecrosis remains unclear. We studied the time course of calcium, phosphorus, osteocalcin, alkaline phosphatase, and mineral density of bone tissue in the subchondral bone of the femoral head of rabbits injected with steroids and attempted to precisely determine the time when disorders in bone metabolism started in animals with steroid-induced osteonecrosis. We detected bone metabolism disorders involved in the early pathogenesis of steroid-induced osteonecrosis, which were the cause, but not the result of this condition.

Tea polyphenols protect bovine mammary epithelial cells from hydrogen peroxide-induced oxidative damage in vitro by activating NFE2L2/HMOX1 pathways.

Periparturient dairy cows are likely subject to altered intracellular reduction-oxidation (redox) balance due to the high metabolic rates and physiological adaptations occurring around parturition. Such conditions could induce oxidative damage. In nonruminants, it is well established that nuclear factor erythroid 2 like 2 (NFE2L2) is a critical transcription factor for maintaining cellular redox balance by inducing adaptive responses against oxidative stress (OS) that can otherwise lead to uncontrolled inflammation. Tea polyphenols (TP), the major polyphenolic constituents of green tea, are potent antioxidants that could exert protective effects on bovine mammary epithelial cells (BMEC) by scavenging free radicals. We used NFE2L2 short interfering RNA (siRNA) to downregulate NFE2L2 expression in cultured BMEC to investigate whether TP could inhibit H2O2-induced OS by activating the NFE2L2/heme oxygenase-1 (HMOX1) pathway. Isolated BMEC were exposed to H2O2 (600 µM) for 6 h to induce OS. Optimal doses of TP (0, 60, 80, and 100 µg/mL) were evaluated by pretreatment of BMEC for 0, 2, 4, 6, 8, 12, and 24 h, followed by a H2O2 (600 µM) challenge for 6 h. The BMEC were transfected with NFE2L2-siRNA for 48 h, pretreated with 100 µg/mL of TP for 12 h, then challenged by 600 µM H2O2 for 6 h. Results revealed that after H2O2 exposure a concentration of TP of 100 µg/mL during a 12-h incubation led to greater cell viability, protein, and mRNA abundance of NFE2L2, and lower intracellular reactive oxygen species (ROS) accumulation. In addition, transfection with NFE2L2-siRNA decreased abundance of NFE2L2 and HMOX1 in spite of exogenous TP supplementation, whereas ROS production was increased in response to exogenous H2O2 (600 µM). Overall, TP had beneficial effects on redox balance in BMEC, slowing down cellular OS-related injury through decreasing the production of ROS and enhancing mechanisms controlled at least in part by the NFE2L2/HMOX1 pathway.

Effect of NB-UVB on levels of MCP-1 and CCR6 mRNA in patients with psoriasis vulgaris.

The aim of this study is to explore the effect of narrow band ultraviolet B (NB-UVB) on the chemokine receptor CCR6 mRNA levels in patients with psoriasis. Psoriasis area and severity index (PASI) values were recorded before and after the treatment with NB-UVB phototherapy of 30 psoriasis vulgaris patients. The reverse transcription-polymerase chain reaction method was used to detect the expression level of CCR6 mRNA in peripheral blood mononuclear cells, and compared with 30 healthy subjects. The PASI value of the 30 psoriasis vulgaris patients decreased significantly after 15 iterations of phototherapy treatment (P < 0.01). The expression level of CCR6 mRNA in psoriasis patients was significantly higher than in the healthy controls (P < 0.01), while the expression level of CCR6 mRNA decreased significantly after phototherapy (P < 0.01). Reduction of CCR6 level may be one of the mechanisms through which NB-UVB can treat psoriasis.

Efficacy of low-level laser therapy in the treatment of TMDs: a meta-analysis of 14 randomised controlled trials.

This study was designed to evaluate the efficacy of low-level laser therapy (LLLT) in the treatment of temporomandibular disorders (TMDs). We searched electronic databases and references lists of relevant articles, retrieved all of the published randomised controlled trials in regard to these issues and then performed a meta-analysis. Fourteen highly qualified RCTs reporting on a total of 454 patients, which evaluated the effectiveness of LLLT for patients suffering from TMDs were retrieved. The results indicated that LLLT was not better than placebo in reducing chronic TMD pain (weighted mean difference = -19·39; 95% confidence interval = -40·80-2·03; P < 0·00001; I(2)  = 99%). However, the LLLT provided significant better functional outcomes in terms of maximum active vertical opening (MAVO) (weighted mean difference = 4·18; 95% confidence interval = 0·73-7·63; P = 0·006; I(2)  = 73%), maximum passive vertical opening (MPVO) (weighted mean difference = 6·73; 95% confidence interval = 01·34-12·13; P = 0·06; I(2)  = 73%), protrusion excursion (PE) (weighted mean difference = 1·81; 95% confidence interval = 0·79-2·83; P = 0·59; I(2)  = 0%) and right lateral excursion (RLE) (weighted mean difference = 2·86; 95% confidence interval = 1·27-4·45; P = 0·01; I(2)  = 73%). The results of our meta-analysis have provided the best evidence on the efficacy of LLLT in the treatment of TMDs. This study indicates that using LLLT has limited efficacy in reducing pain in patients with TMDs. However, LLLT can significantly improve the functional outcomes of patients with TMDs.

Dissecting the mechanism of Solanum lycopersicum and Solanum chilense flower colour formation.

Flowers are the defining feature of angiosperms, and function as indispensable organs for sexual reproduction. Flower colour typically plays an important role in attracting pollinators, and can show considerable variation, even between closely related species. For example, domesticated tomato (S. lycopersicum) has orange/yellow flowers, while the wild relative S. chilense (accession LA2405) has bright yellow flowers. In this study, the mechanism of flower colour formation in these two species was compared by evaluating the accumulation of carotenoids, assessing the expression genes related to carotenoid biosynthetic pathways and observing chromoplast ultrastructure. In S. chilense petals, genes associated with the lutein branch of the carotenoid biosynthetic pathway, phytoene desaturase (PDS), ζ-carotene desaturase (ZDS), lycopene ß-cyclase (LCY-B), ß-ring hydroxylase (CRTR-B) and ε-ring hydroxylase (CRTR-E), were highly expressed, and this was correlated with high levels of lutein accumulation. In contrast, PDS, ZDS and CYC-B from the neoxanthin biosynthetic branch were highly expressed in S. lycopersicum anthers, leading to increased ß-carotene accumulation and hence an orange/yellow colour. Changes in the size, amount and electron density of plastoglobules in chromoplasts provided further evidence of carotenoid accumulation and flower colour formation. Taken together, these results reveal the biochemical basis of differences in carotenoid pigment accumulation and colour between petals and anthers in tomato.

Linezolid in the treatment of extensively drug-resistant tuberculosis.

PURPOSE: To investigate the linezolid (LZD) treatment outcome and correlation between in vitro susceptibility to LZD and clinical outcome. METHODS: We retrospectively reviewed records of tuberculosis (TB) patients who received treatment with linezolid between March 2012 and February 2013. RESULTS: A total of 43 extensively drug-resistant (XDR) TB patients identified by drug susceptibility testing were enrolled in this study, including 15 (34.9 %) received LZD as part of individualized treatment regimens. Among the 43 XDR TB patients, 15 patients (34.9 %) obtained favorable clinical outcome, including 9 (60.0 %) from LZD group and 6 (21.4 %) from control group without LZD. Statistical analysis revealed that the percentage of favorable outcomes of LZD group was significantly higher than that of control group (P = 0.011). Furthermore, we analyzed the LZD minimum inhibitory concentrations of Mycobacterium tuberculosis (MTB) isolates from patients in LZD group and identified 4 (26.7 %) resistant to LZD. All of the patients with LZD resistance harbored adverse clinical outcome, while most of the patients infected with LZD sensitive MTB harbored favorable clinical outcome (81.8 %, 9/11). Statistical analysis revealed that the percentage of favorable outcome among the patients with LZD resistance was statistically lower than that among the LZD susceptible group (P = 0.011). CONCLUSION: This study demonstrates that linezolid has efficacy against XDR pulmonary TB patients, even in shorter duration of administration. The XDR TB patients infected with LZD-resistant isolates were more likely to obtain the adverse clinical outcome under the treatment of regimen containing LZD.

Comparative study between Ephedra sinica Stapf and Fructus Schisandrae Chinensis on ET-1 and 6-keto-prostaglandin F1α in rats with idiopathic pulmonary fibrosis.

The aim of this study was to evaluate differences in the effects of Ephedra sinica Stapf and Fructus Schisandrae Chinensis on angiogenesis in the treatment of bleomycin-induced rat idiopathic pulmonary fibrosis. The rat models were created using bleomycin. The animals were divided into six groups: model, control, Ephedra alone, Schisandrae alone, combination of Ephedra and Schisandrae, and hydrocortisone alone. The treatments were administered for 28 days. After 7 and 28 days, the rats were sacrificed for pathological morphology examination, microvascular density determination, and angiogenesis-related cytokine examination. The Ephedra and hydrocortisone groups demonstrated significantly reduced alveolitis and pulmonary fibrosis grades compared with the model group (P < 0.05). The number of blood vessels in the Ephedra group was higher than that in the Schisandrae and combination therapy groups. At 7 days, the expression level of endothelin (ET)-1 in the model group was significantly higher than that in the normal group (P < 0.01). The level of 6-keto-prostaglandin F1α (6-keto-PGF1α) in the treatment group increased, and there were significant differences between the Ephedra group and the combination therapy and normal groups (P < 0.05). Ephedra inhibited the increase in the lung coefficient. The combination therapy prevented pulmonary artery injury and angiogenesis of the arteries by reducing the level of ET-1 and promoting the level of 6-keto-PGF1α in the blood. Ephedra and Schisandrae prevented alveolitis and the development of pulmonary fibrosis.

High-dose glucose-insulin-potassium treatment reduces myocardial apoptosis in patients with acute myocardial infarction.

BACKGROUND: Several clinical trials have suggested that a metabolic cocktail of glucose-insulin-potassium (GIK) decreases mortality rates in patients with acute myocardial infarction (AMI). It has also been reported that Fas-mediated apoptosis plays an important role in ischaemic/reperfusion injury in the rat model. This study was designed to evaluate the interaction of ischaemic/reperfusion and reperfusion therapy coadministered with high-dose GIK treatment on soluble Fas/APO-1 (sFas) and Fas ligand (sFasL) plasma concentration in patients with AMI. MATERIALS AND METHODS: Seventy-four patients presenting with AMI who underwent reperfusion therapy were randomized into a GIK group (n = 35) receiving high-dose GIK for 24 h or a vehicle group (n = 39). Thirty-four control subjects were also enrolled in the present study. Strepavidin-biotin ELISA was used to determine the soluble sFas and sFasL plasma concentration at baseline, 24 h (h), 3 day (d), 7 d and 14 d. RESULTS: Soluble Fas and sFas-L serum concentrations ([sFas] and [sFas-L]) of patients with AMI were significantly elevated at baseline as compared with normal controls (NCs; P < 0.01 vs. NC). The sFas in the GIK and vehicle groups markedly decreased 24 h after the GIK infusion (10.7-->5.9 ng mL(-1) and 9.7-->6.5 ng mL(-1); P < 0.01 vs. baseline) and then increased during the 3-7-d period (5.9-->12.1 ng mL(-1) and 6.5-->11.1 ng mL(-1); P < 0.01 vs. 24 h). The GIK group demonstrated reduced sFas (12.1-->5.9 ng mL(-1)) at 14 d (P < 0.01 vs. 7 d), with no concomitant changes in the vehicle group. The sFas-L in the GIK and vehicle groups was not significant different during the 14-d period. CONCLUSIONS: These results indicate that the sFas and sFasL in patients with AMI increased significantly compared with NC. Owing to the cardioprotective effects reported here and by others, a high-dose GIK infusion co-administered with the timely re-establishment of nutritive perfusion should be strongly considered as a treatment of choice for AMI. Additionally, sFas may be a valuable marker of the physiological response to ischaemic/reperfusion injury and reperfusion associated with high-dose GIK treatment.

Dual control of the nodA operon of Azorhizobium caulinodans ORS571 by a nod box and a NifA-sigma54-type promoter.

Earlier studies have shown that the Azorhizohium caulinodans nodA promoter is controlled by a host plant-derived flavonoid signal via the transcription activator NodD. Here, we report that the transcription of the nodA operon is also under the control of NifA-RpoN. A NifA-sigma54-type promoter, P2nodA, is present upstream of the nod-box consensus motif of the nodA gene and directs expression of a nodA-uidA reporter gene both in free-living bacteria under nitrogen fixation conditions and in bacteroids. Mutation of P2nodA reduced, under certain conditions, the efficiency of nodulation and accelerated nodule senescence, suggesting that the dual control may help to optimize nodule initiation and function in the natural context of the symbiosis.

Characterization of binding of leukotriene C4 by human multidrug resistance protein 1: evidence of differential interactions with NH2- and COOH-proximal halves of the protein.

Multidrug resistance protein 1 (MRP1) is capable of actively transporting a wide range of conjugated and unconjugated organic anions. The protein can also transport additional conjugated and unconjugated compounds in a GSH- or S-methyl GSH-stimulated manner. How MRP1 binds and transports such structurally diverse substrates is not known. We have used [(3)H]leukotriene C(4) (LTC(4)), a high affinity glutathione-conjugated physiological substrate, to photolabel intact MRP1, as well as fragments of the protein expressed in insect cells. These studies revealed that: (i) LTC(4) labels sites in the NH(2)- and COOH-proximal halves of MRP1, (ii) labeling of the NH(2)-half of MRP1 is localized to a region encompassing membrane-spanning domain (MSD) 2 and nucleotide binding domain (NBD) 1, (iii) labeling of this region is dependent on the presence of all or part of the cytoplasmic loop (CL3) linking MSD1 and MSD2, but not on the presence of MSD1, (iv) labeling of the NH(2)-proximal site is preferentially inhibited by S-methyl GSH, (v) labeling of the COOH-proximal half of the protein occurs in a region encompassing transmembrane helices 14-17 and appears not to require NBD2 or the cytoplasmic COOH-terminal region of the protein, (vi) labeling of intact MRP1 by LTC(4) is strongly attenuated in the presence of ATP and vanadate, and this decrease in labeling is attributable to a marked reduction in LTC(4) binding to the NH(2)-proximal site, and (vii) the attenuation of LTC(4) binding to the NH(2)-proximal site is a consequence of ATP hydrolysis and trapping of Vi-ADP exclusively at NBD2. These data suggest that MRP1-mediated transport involves a conformational change, driven by ATP hydrolysis at NBD2, that alters the affinity with which LTC(4) binds to one of two sites composed, at least in part, of elements in the NH(2)-proximal half of the protein.

PG490-88, a derivative of triptolide, blocks bleomycin-induced lung fibrosis.

In this study we evaluate the antifibrotic properties of PG-490-88, a water-soluble derivative of triptolide. Triptolide is an oxygenated diterpene that is derived from a traditional Chinese herb that has potent immunosuppressive and antitumor activity. We used the intratracheal bleomycin mouse model and found that PG490-88 inhibits fibrosis in the bleomycin group when given the same day or 5 days after bleomycin. PG490-88 also markedly reduced the number of myofibroblasts in the bleomycin treatment group. An enzyme-linked immunosorbent assay of transforming growth factor (TGF)-beta in the bronchoalveolar lavage fluid showed a significant decrease in TGF-beta in the PG490-88-treated groups compared to the bleomycin-treated group. Additionally, triptolide blocked bleomycin-induced increase in TGF-beta mRNA in cultured normal human lung fibroblasts. The efficacy of PG490-88 when administered late after bleomycin installation suggests a potential role in the treatment of idiopathic pulmonary fibrosis.

[An experimental study on inhibitory effect of xinjierkang granules on virus myocarditis].

OBJECTIVE: To investigate the inhibitory effect of Xinjierkang(XJEK) granules on virus myocarditis. METHODS: Using a model mouse of virus myocarditis induced by coxsackie virus B3m (CVB3m) and mouse toxic myocarditis induced by adriamycin, a model of arrhythmia induced by BaCl2 and CHCl3, a model of inflammation caused by egg white and agar, along with a dynamic test of cardiac blood flow and an inhibitory test of CVB3m in vitro. RESULTS: XJEK granules are efficacious in inhibiting CVB3m both in vitro and in vivo, protecting and curing virus myocarditis and toxic myocarditis in mice, reducing mouse death rate, serum level of LDH, AST and CK, titer of neutralizing antibodies, virus concentration of heart, and improving the abnormal ECG, pathological and ultrastructural damage of myocadium. The granules are also good for anti-inflammation, anti-myocardial ischemia, anti-arrhythmia, as well as for strengthening myocardiac contraction and increasing the serum IgG level. CONCLUSION: Xinjerkang granules possess an inhibitory effect on virus myocarditis and toxic myocarditis.

[Improving memory effects of eel oil capsule on memory obstruction of mice hurt by anisodine].

The effects of eel oil capsule on memory obstruction of mice were observed in step-down test, step-through test, Y-maze test and Japanese labyrinth test. The results indicated that the eel oil capsule treating group with dosages of 0.234, 0.702 and 2.106 g/kg markedly enhance the acquirement, strengthing and reappearance of memory, having the functions of improving brain memory hurt by Anisodine.

[Study on relationship between two different syndromes and three soluble cytokine receptors in patients with rheumatoid arthritis].

OBJECTIVE: To study the relationship between two different Syndromes (Cold-Damp Syndrome and Damp-Heat Syndrome) and three soluble cytokine receptors (sCKR, soluble interleukin-2 receptor, sIL-2R, soluble interleukin-6 receptor, sIL-6R, soluble tumor necrosis factor receptor 1, sTNFR1) in rheumatoid arthritis (RA). METHODS: The serum levels of three soluble receptors were measured by ELISA in patients with RA. RESULTS: The serum levels of 3 sCKR were significantly elevated in RA patients compared to healthy controls and obviously lowered after treatment (P < 0.01). The level of sIL-2R was significantly higher in Cold-Damp Syndrome than that in Damp-Heat Syndrome (P < 0.01), but serum sTNFR1 was significantly higher in Damp-Heat Syndrome than that in Cold-Damp Syndrome, there was no obvious difference between sIL-6R of two Syndromes. CONCLUSION: The high serum sIL-2R and low sTNFR1 might be a criterion of Cold-Damp Syndrome, but the high sTNFR1 and low sIL-2R might be a criterion of Damp-Heat Syndrome, these criteria reflected some states of different functions in immune system in patients with RA.

Study on pathogenic mechanism of emotions in traditional Chinese medicine--an observation of hydrogen peroxide releasing function of celiac macrophages in rats under stress state.

The hydrogen peroxide releasing function of macrophages in rats under the stress state was observed with the animal model of "excessive anger impairing the liver". The results showed that the volume of hydrogen peroxide released from the macrophages in rats was decreased, while the corticosterone level in plasma increased after stress. It indicates that stimulation of harmful emotions could cause inhibition of immunoreaction of the organism, which might be related to the enhancement in excitability of the hypothalamus-pituitary-adrenal axis and hypersecretion of glucocorticoid hormone.

[Study on changes of plasma substance P in essential hypertension with left ventricular hypertrophy patients and the effect of promoting blood circulation and eliminating phlegm].

OBJECTIVE: Exploring the relationship between the plasma substance P(SP) and essential hypertension with left ventricular hypertrophy (EH-LVH) and the effect of promoting blood circulation and eliminating phlegm. METHODS: Before and after treatment, the changes of SP in patients wiith EH-LVH were measured by radioimmunoassay. Meanwhile, the changes of plasma renin activity (PRA), angiotension II (Ang II), left ventricular mass index (LVMI) and mean arterial pressure (MAP) were measured. RESULTS: The level of plasma SP in patients with EH-LVH was markedly lower than that of patients without EH-NLVH and healthy subjects (P < 0.001); the levels of PRA and Ang II were higher than those in control group (P < 0.01 or < 0.05). After treatment, the level of SP was significantly increased, while LVMI, MAP, PRA and Ang II were significantly decrease (P < 0.01 or < 0.05). The levels between SP and LVMI, MAP, PRA, Ang II were markedly negative correlated (P < 0.01) while levels between LVMI and PRA, Ang II were markedly positive correlated. CONCLUSIONS: The SP may be involved in the pathogenesis of EH-LVH; the mechanism of promoting blood circulation and eliminating phlegm reversing LVH might be related to its increasing the plasma SP.

Epidemiological survey of oral submucous fibrosis in Xiangtan City, Hunan Province, China.

Oral submucous fibrosis is a high risk precancerous condition and is suggested to be caused by areca nut chewing. Areca nut chewing is popular in Hunan Province of China, and is more concentrated in Xiangtan City. Two and nine cases of oral submucous fibrosis (OSF) were first noticed in 1984 and 1985 respectively, and an epidemiologic survey was subsequently performed in 1986. The epidermiologic method of cluster sampling was used. The Yuhu District, one of the five urban districts of the Xiangtan City with a population of 100,000 was selected as a whole body in the survey, 57 independent units of various professions were randomly selected as group samples and more than 70% of subjects in each unit were examined. Definite fibrous band on palpation was used as a main diagnostic criterion for OSF. A total of 11046 individuals were examined; among them were 3907 areca nut chewers (35.37%) and 7139 non-chewers (64.63%). 335 cases of OSF were found, comprising a prevalence rate of 3.03%. The disease involved mainly the middle third of the oral cavity. All of the OSF cases were areca nut chewers. No case had been found in non-chewers. Four cases of oral carcinoma were found on the basis of OSF, the malignant transformation rate was 1.19%. The high prevalence of OSF may be due to areca nut chewing plus extensive and heavy use of hot pepper in Xiangtan people. The result supports the role of the areca nut as an etiologic factor in the development of OSF. The low malignant transformation rate of 1.19% compared with the 7.6% in an Indian report may be because Xiangtan people chew areca nut without tobacco.