[Lymphatic targeting study of pingyangmycin-activated carbon nanoparticles treating oral cancer lymph node metastasis].

OBJECTIVE: To investigate the drug distribution in tissues of cervical lymph node metastasis mice model after submucosa adjacent cancer injection of pingyangmycin-activated carbon nanoparticles (PYM-CH-NP) and evaluate the lymph targeting effect of PYM-CH-NP. METHODS: Pingyangmycin (PYM) was radiolabeled with 125I by modified the chloramine T method. Cervical lymph node metastasis mice model was established by buccal submucosa inoculation of a high lymph metastasis cell line U14 cancer cell. 360 mice models burdened with cervical lymph metastasis were randomly divided into 3 groups. PYM group was treated with PYM water solution, PYM-CH-NP group was treated with PYM-CH-NP. Negative control group was injected with activated carbon nanoparticles. PYM-CH-NP and pingyangmycin water solution were injected in pericancer submucosa of the mice respectively. The radioactivity of drug in blood, heart, liver, spleen, lung, kidney and cervical lymph node were measured after 0.5, 1, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168 h administration. The radioactivity of each samples per unit weight were calculated. The selectivity index (SI) and targeting index (TI) of drug were calculated. RESULTS: The radioactivity of drug in cervical lymph node of PYM-CH-NP group was much higher than PYM group in each time point (P < 0.001), whereas the blood, heart, liver, spleen, lung and kidney uptake of pingyangmycin was greatly decreased in PYM-CH-NP group after 4 h administration (P < 0.001). The SI value of PYM group at each time point was less than 1. While the minimum SI and TI value of PYM-CH-NP was 1.793 and 1.562, the maximum value reached to 68.126 and 14.623 after 72 h administration. CONCLUSION: PYM-CH-NP can increase drug dosage in metastasized cervical lymph nodes, and decrease drug dosage of other organs. So better therapeutic outcome and little adverse reaction may be achieved for lymph node metastasis.

Management of sternal osteomyelitis and mediastinal infection following median sternotomy.

BACKGROUND: Median sternotomy is considered the most usually performed procedure in cardiac operations. This study aimed to assess clinical effectiveness of bilateral pectoralis major muscle flaps (BPMMF) for management of sternal osteomyelitis and mediastinal infection following median sternotomy. METHODS: Clinical data were collected and retrospectively analyzed from twelve patients who underwent the BPMMF transposition for management of sternal osteomyelitis and mediastinal infection following median sternotomy from January 2006 to June 2009. Procedure consisted of rigorous debridement of necrotic tissues, dead space obliteration using the BPMMF, and placement of drainage tubes connected to a negative pressures generator for adequate drainage. RESULTS: No patients died of drainage, and all 12 patients had viable BPMMF when discharged from hospital. At 1 week post discharge, 2 patients presented with sternal infection but recovered following local debridement and medication. No patients showed infection recurrence during the follow-up period over 10 months. CONCLUSIONS: Sternal osteomyelitis and mediastinal infection following median sternotomy may be effectively managed through rigorous debridement of infected soft tissues, resection of the damaged sternal segment, transposition of the BPMMF to fill the damaged sternum resulting from debridement, and adequate postoperative drainage.

Derived vascular endothelial cells induced by mucoepidermoid carcinoma cells: 3-dimensional collagen matrix model.

Mucoepidermoid carcinoma undergoes uniquely vigorous angiogenic and neovascularization processes, possibly due to proliferation of vascular endothelial cells (ECs) induced by mucoepidermoid carcinoma cells (MCCs) in their three-dimensional (3D) microenvironment. To date, no studies have dealt with tumor cells and vascular ECs from the same origin of mucoepidermoid carcinoma using the in vitro 3D microenvironment model. In this context, the current research aims to observe neovascularization with mucoepidermoid carcinoma microvascular ECs (MCMECs) conditioned by the microenvironment in the 3D collagen matrix model. We observed the growth of MCMECs purified by immunomagnetic beads and induced by MCCs, and characteristics of tubule-like structures (TLSs) formed by induced MCMECs or non-induced MCMECs. The assessment parameters involved the growth curve, the length, the outer and inner diameters, and the wall thickness of the TLSs, and the cell cycle. Results showed that MCCs induced formation of the TLSs in the 3D collagen matrix model. A statistically significant difference was noted regarding the count of TLSs between the control group and the induction group on the 4th day of culture (t=5.00, P=0.001). The outer and inner diameters (t(1)=5.549, P(1)=0.000; t(2)=10.663, P(2)=0.000) and lengths (t=18.035, P=0.000) of the TLSs in the induction group were statistically significant larger than those in the control group. The TLSs were formed at the earlier time in the induction group compared with the control group. It is concluded that MCCs promote growth and migration of MCMECs, and formation of the TLSs. The 3D collagen matrix model with MCMECs induced by MCCs in the current research may be a favorable choice for research on pro-angiogenic factors in progression of mucoepidermoid carcinoma.

[Anticancer effects of Pingyangmycin-activated carbon nanoparticles against human oral squamous carcinoma Tca8113 and BcaCD885 cell lines in vitro].

OBJECTIVE: The cytotoxic effects of a new formulation of Pingyangmycin-activated carbon nanoparticles (PYM-CH-NP) on two human oral squamous cell carcinoma Tca8113 and BcaCD885 cell lines were studied in vitro. METHODS: The inhibitory effects of PYM-CH-NP and Pingyangmycin (PYM) were evaluated by methyl thiazolyl tetrazolium (MTT) assay at 1-7 days. The 50% inhibition concentration values (IC50) and relative antitumor activity (RAA) of PYM-CH-NP and PYM against Tca8113 and BcaCD885 with different drug concentration were evaluated. The time-dependent cytotoxic effects of PYM-CH-NP and PYM were during 1-5 days, so the doseeffect relationship was investigated at 5th day. RESULTS: Both PYM-CH-NP and PYM had high anticancer effects on Tca8113 and BcaCD885, and the cytotoxic effects were dose-dependent and time-dependent. CONCLUSION: The activated carbon nanoparticles (CH-NP) may serve as a new drug delivery carrier of PYM. The new formulation PYM-CH-NP could slow down drug release, prolonged the drug concentration and its acting time, so more effective anticancer efficacy could be achieved.

[Intralesional Pingyangmycin therapy for 51 infantile patients with parotid gland hemangiomas].

PURPOSE: To investigate the indication and outcome of intralesional Pingyangmycin (PYM) therapy for parotid gland hemangiomas in early childhood. METHODS: 51 infantile patients with hemangiomas in the parotid gland were studied retrospectively, which had been treated in the clinic of West China Hospital of Stomatology, Sichuan University during the 15-year period from May 1990 to May 2005. In this study, 21 were male, 30 were female, and the ratio of male to female was 1:1.43. The age of the children ranged from 6 months to 4 years, with an average age of 10 months. 38 were deep-seated hemangiomas, and 13 were mixed hemangiomas. 27 were in the right parotid gland and 24 in the left, no bilateral case. All the patients underwent intralesional injection of a solution of 8 mg PYM in 8 mL normal saline mixed with 5 mg dexamethasone. The total dose of PYM ranged from 20mg to 35 mg, which was administered 0.5 or 1 mg per injection. SPSS10.0 software package was used to compare the treatment efficacy between the patients with hemangioma <4 cm in diameter and >or=4 cm in diameter. RESULTS: Hemangiomas of 42 cases (82.35%) showed complete resolution with good appearance, 8 cases (15.69%) were partly regressed, and 1 case (1.96%) had no obvious size change. No serious side effects were seen, such as pulmonary fibrosis and growth inhibition. No significant correlation was found between treatment efficacy and tumor size. CONCLUSION: Intralesional PYM therapy maybe is a selective primary therapy option for parotid gland hemangioma, and ultrasonography should be useful for diagnosis and treatment of this lesion.

The expression profile of microRNAs in a model of 7,12-dimethyl-benz[a]anthrance-induced oral carcinogenesis in Syrian hamster.

BACKGROUND: Non-coding RNA molecules, such as microRNAs, may play an important role in carcinogenesis. Recent studies have indicated that microRNAs are involved in initiation and progression of various malignancies. However, little work has been done to compare the microRNA expression patterns in oral cancer. In this study, we constructed an animal model of oral squamous cell carcinoma to investigate expression profiles of microRNAs in oral carcinogenesis. METHODS: The animal model of oral squamous cell carcinoma was conducted by tri-weekly (Monday, Wednesday, and Friday) painting with 5% DMBA in acetone. Six Syrian hamsters, including three from the treated group and three from the control group, were used as a training group for microRNA microarray analysis. All microarray data were analyzed by Significance Analysis of Microarrays (SAM) and CLUSTER 3.0 software, and this result was further confirmed by qRT-PCR assay. RESULTS: Seventeen microRNAs were differentially expressed in oral squamous cell carcinoma. Five microRNAs (hsa-miR-21, hsa-miR-200b, hsa-miR-221, hsa-miR-338, and mmu-miR-762) were significantly upregulated and twelve microRNAs (hsa-miR-16, hsa-miR-26a, hsa-miR-29a, hsa-miR-124a, hsa-miR-125b, mmu-miR-126-5p, hsa-miR-143, hsa-miR-145, hsa-miR-148b, hsa-miR-155, hsa-miR-199a, and hsa-miR-203) were down-regulated in cancer tissues. The expression levels of hsa-miR-21 and hsa-miR-16 seen with Stem-loop qRT-PCR were also seen in microarray analysis in all samples. CONCLUSION: Our findings identified specific microRNA expression in oral squamous cell carcinoma and suggested that microRNAs have a role in oral carcinogenesis.

[Embolization and degradation of arteries in vivo by pingyangmycin albumin microspheres].

OBJECTIVE: To investigate the embolization effect of Pingyangmycin-albumin microspheres (PYM-AMS) on small arteries and its process of degradation in vivo. METHODS: Twenty four Japanese white rabbits were randomly divided into four groups, 6 in each group. PYM hydrochloride + 0.9% NaCl, PYM + soybean oil, and PYM-AMS + soybean oil were injected into the central auricular arteries of the rabbits in the three experimental groups, respectively, for about 30 seconds (0.26 mL/per ear, which contained PYM 5 mg/mL). The vessel samples were taken and examined at 2, 7, 14, and 21 days. RESULTS: The PYM + 0.9% NaCl group had no significant vessel changes. In the PYM+ soybean oil group, some endothelial cells dropped off at the 7th day after injection. At the 21st day, mild proliferation of endothelial cells and walls of central auricular arteries were observed, especially on the intima. But the lumen was still obvious and the blood flow was not blocked. In the PYM-AMS group, the central auricular arteries were narrowed at the 7th day after injection. At the 21st day, the vessels had sclerostenosis, and the blood flow was blocked. At the 14th day, significant proliferation of endothelial cells and walls of central auricular arteries were observed. The surface of PYM-AMS was absorbed. At the 21st day, the walls of central auricular arteries and some small veins proliferated obviously, and the arteries were sclerostenosed. Many smooth muscle cells, fibroblasts, and myofibroblasts in the original blood vessel lumen appeared. There were thrombi besides the PYM-AMS. CONCLUSION: PYM-AMS may become an option for the treatment of large venous or arteriovenous malformations and for the local chemotherapy of malignant tumors.

Metastatic tumors to the oral and maxillofacial region: a retrospective study of 19 cases in West China and review of the Chinese and English literature.

PURPOSE: The aim of this article was to obtain an overview of metastatic tumors to the oral and maxillofacial (OMF) region, especially the differences in the constituent ratios of primary cancers between the United States and China. PATIENTS AND METHODS: Clinical findings of 19 cases encountered in West China Hospital of Stomatology were summarized and the English and Chinese literature were reviewed and analyzed. The main clinical features of OMF metastases were summarized, with an emphasis on primary cancers' constituents. RESULTS: The lung, breast, kidney, liver, and prostate were the top 5 common primary sites of cancer. However, there was a significant difference in the primary cancers' constituents between United States and China (P < .001). The breast, kidney, prostate cancers, and melanoma of skin were more frequent primary cancers in United States than in China, whereas that of the lung, thyroid, liver, esophagus, and the stomach were more common in China than in United States. The proportions of the OMF metastatic lesions originating in the lung, kidney, liver, thyroid, and esophagus in all OMF metastatic tumors were higher than the corresponding primary cancers' prevalent proportions. CONCLUSIONS: The frequency of developing OMF metastasis is not always consistent with primary cancers' prevalence, which suggests that different cancers have different potentiality to develop OMF metastasis. Cancers of the kidney, liver, lung, thyroid, and esophagus were more likely to spread to the OMF region. In general screening of primary cancer, it would be helpful to take into account the metastatic potentiality of different cancers and primary cancers' prevalence in different countries in the case of occult primary.

Correlation between the expression of thrombospondin-1 and neovascularization in mucoepidermoid carcinoma.

BACKGROUND: Researchers have recently demonstrated that thrombospondin-1 (TSP-1) has an important function in regulating neovascularization. Whether it inhibits or accelerates neovascularization, however, is still controversial. We found few reports about the correlation between TSP-1 and vascularization in mucoepidermoid carcinoma. In this research, the distribution and expression of TSP-1 in mucoepidermoid carcinoma were investigated. We also analyzed (1) the correlation between the expression of TSP-1 and microvessel density (MVD), as an indicator of neovascularization activity, and (2) the effect of TSP-1 on neovascularization and tumor growth in the subcutaneous xenotransplanted model of mucoepidermoid carcinoma. METHOD: (1) The sites and intensity of expression of TSP-1 and the MVD were analyzed in 45 cases of mucoepidermoid carcinoma after surgery by the method of streptavidin-peroxidase (SP) immunohistochemistry; and (2) recombinant human thrombospondin-1 (rhTSP-1) was injected twice a week for five consecutive weeks around the tumor in the subcutaneous xenotransplanted tumor model of mucoepidermoid carcinoma in nude mice. Each week, the tumor size was measured, in order to draw the growth curve of the xenotransplanted tumor model of mucoepidermoid carcinoma, and MVD was measured. RESULTS: (1) The positive expression of TSP-1 protein was 57.78% (26/45). Most positive staining for TSP-1 was found in the cytoplasm of the cancer cells, while some staining occurred in the extracellular matrix. The mean MVD in 45 cases of mucoepidermoid carcinoma was 58.17 +/- 19.77 per 100 visual fields. Tumors with a high expression of TSP-1 showed a low MVD value, and the TSP-1 immunocompetence and microvessel density showed a significant negative correlation (r(s) = -0.947, P < 0.001). (2) The xenotransplanted tumors with the injection doses of 1.25, 0.75 and 0.25 microg/ml respectively were 36.97%, 53.36% and 73.61% of the size of the control group ((451 +/- 92), (651 +/- 113), (898 +/- 86) and (1220 +/- 157) mm(3) respectively, F = 53.167, P < 0.001), and their weights were respectively 35.14%, 51.35% and 70.27% of the control group ((1.3 +/- 0.5), (1.9 +/- 0.5), (2.6 +/- 0.3), and (3.7 +/- 0.7) g respectively, F = 62.669, P < 0.001). Their MVDs were 25.00%, 45.93%, and 72.20% respectively of the control group and concentration dependent (15.43 +/- 3.45, 28.35 +/- 4.24, 44.57 +/- 3.35 and 61.73 +/- 5.43 per 100 visual fields respectively, F = 54.582, P < 0.001). CONCLUSIONS: The TSP-1 has a higher expression in mucoepidermoid carcinoma and the expression has a significant negative correlation with neovascularization. The TSP-1 inhibits neovascularization and tumor growth, and it might be a new biological therapy for treatment of patients with mucoepidermoid carcinoma.

[Study of increased sensitivity on Tca8113 cell line to cisplatin by nm23-H1 in vitro].

OBJECTIVE: To study the mechanism of sensitivity variation to cisplatin caused by nm23-H1. METHODS: The samles was divided into two groups: Tca8113 group and Tca8113/nm23-H1 group. Using MTT and flow cytometer, the changes of cell mortality rate, apoptosis and mitochondrial membrane potential were detected. By VG PQ Excell, the changes of the intracellular platinum were detected. RESULTS: In vitro the cell mortality rate and apoptosis were increased in Tca8113/nm23-H1 group, comparing with Tea8113 group. Mitochondrial membrane potential was decreased in Tca8113/nm23-H1 group. The intracellular platinum was increased significantly in Tca8113/nm23-H1 group. This effect could be inhibited by oubain which was an inhibitor of Na+/K+-ATP. CONCLUSION: nm23-H1 can increase the sensitivity of cisplatin on Tca8113 cell line. The mitochondrial membrane potential was decreased by nm23-H1 so that intracellular platinum was increased and finally increased the apoptosis or necrosis.

[Correlation between the expression of thrombospondin-1 and the angiogenesis in mucoepidermoid carcinoma].

OBJECTIVE: To study the relationship between the expression of thrombospondin-1 (TSP-1) and the angiogenesis in mucoepidermoid carcinoma. METHODS: Immunohistochemistry were applied to detect the expression of TSP-1 and the value of microvessel density (MVD) in 45 mucoepidermoid carcinoma patients. RESULTS: Positive expressions of TSP-1 protein were detected in 26 of the 45 (57. 78%) cases. Most positive staining for TSP-1 was observed in the cytoplasm of the cancer cells, some of those were in the extracellular matrix. The mean MVD in 45 cases with mucoepidermoid carcinoma was 60. 68 +/- 19.84 vessels per 100 field of vision. Tumors with a high expression of TSP-1 showed a low value of MVD and the correlation between TSP-1 immunocompetence and microvessel density was highly significant (r(s) = -0.942, P < 0.001). CONCLUSION: The TSP-1 is expressed in most mucoepidermoid carcinoma and were associated with neovascularization. TSP-1 is likely to inhibit the extensive neovascularization and increased TSP-1 expression might inhibit angiogenic phenotype in mucoepidermoid carcinoma.

[A clinical retrospective study on modified parotidectomy in benign tumors of parotid gland].

PURPOSE: A clinical perspective study was designed for patients undergoing a modified parotidectomy to reduce complications of parotidectomy. METHODS: 110 patients were divided randomly into two groups; Group 1 (55 cases) was operated via routine surgical modality. Group 2(55 cases) was treated with preserving the fascia parotideomasseterica and great auricular nerve and partial parotidectomy. Tumor size, blood loss, operating time, temporary facial paralysis, tumour recurrence were compared between the two groups. The follow-up period was 2 years. The incidence of Frey's syndrome was clinically evaluated by Minor test (starch-iodine test). The feeling of the region around the auricular lobule was also evaluated. The data were analyzed using SPSS10.0 software package for Student's t test and Chi-square test. RESULTS: There was no significant difference between the two groups in tumor size, temporary facial paralysis and tumor recurrence. Group 1 was significantly lower than that in Group 2 in the bleeding volume and operating time. The incidence rate of Frey's syndrome in Group 1 was significantly lower than that in Group 2 by objective observation and Minor test. There was significant difference between the feeling of pro- operation and pre-operation in the auricular lobule. CONCLUSIONS: The modified parotidectomy is a function-preserving surgery for benign parotid tumours, which improves the cosmetics, the feeling around ear, reduces the duration of surgery, and the incidence rate of Frey's syndrome. Supported by Research Fund of Science and Technology Bureau of Shanxi Province [Grant No.2005K14-G8(2)] and Science and Technology Project of Xi'an City [Grant No.SF08008-(4)].

Clinical analysis of salivary gland tumor cases in West China in past 50 years.

In our study, 3461 cases of salivary gland tumor treated between 1955 and 2002 at West China Stomatology Hospital of Sichuan University were retrospectively analyzed, and compared with the previous reports. Measures such as age, tumor location, tumor histological type, and the nature of the growth (benign or malignant) were recorded at the same time. The findings are as follows: the average ages of salivary gland tumor patients were 41.38 years for the benign cases and 45.20 for the malignant ones; the male:female ratio was 0. 99:1 in the benign cases and 1.34:1 in the malignant ones; primary tumors were mostly in the parotid gland, palate and submandibular gland in sequence. Pleomorphic adenoma was the most frequent benign tumor followed by Warthin's tumor and basal cell adenoma, whereas mucoepidermoid carcinoma, adenoid cystic carcinoma and adenocarcinoma not otherwise specified were the most frequent malignant tumors. The incidence of salivary gland tumors increased with age. The male:female ratio of malignant tumors was higher than that of benign ones. The parotid gland and palate were the most common locations of salivary gland tumors. Pleomorphic adenoma and mucoepidermoid carcinoma were the most frequent benign and malignant tumors, respectively.

[Proteomics study of the serum biomarkers in tongue cancer].

OBJECTIVE: To search for specific serum biomarkers associated with tongue cancer by means of the serum proteomics technology. METHODS: The tongue cancer cells of human tongue cancer cell line Tca8113 were subcutaneously inoculated into nude mice, while control nude mice were injected with phosphate-buffered saline. Serums from these two group of mice were collected for proteomic analysis using two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). RESULTS: Comparing the serum 2-DE maps from the tumor-bearing mice with those produced from control mice, we found that squamous cell carcinoma antigen 1 was over expressed only in the serum of tumor-bearing mice. CONCLUSIONS: The squamous cell carcinoma antigen 1 may be of great potential as the biomarker of tongue cancer and as the potential therapeutic target for gene therapy.

[Analyses of differential expression of Homeobox genes between lingual squamaous cell carcinoma and normal mucosa].

OBJECTIVE: To investigate the differently expressed Homeobox genes between lingual squmaous cell carcinoma and normal mucosa. METHODS: Seven paired specimens including lingual squmaous cell carcinoma and its surrounding normal tissue were obtained from 7 patients. Customized Oligo microarray which contains numerous probes of 232 human Homeobox genes was used to analyse the results. All datas were scanned by Agilent scanner and differentiately expressed genes were sorted out. RESULTS: Homeobox gene NANOG was found up-regulated in 5 samples. PHTF2 was found down-regulated in 7 samples, and CRX, PITX1, OTEX was found down-regulated in 5 samples. CONCLUSION: As the key gene to cellular proliferation and differentiation, Homeobox genes is closely releverant to the oncogenesis of lingual squmaous cell carcinoma.

[Effect on induction of differentiation of Tca8113 cells affected by abscisic acid in vitro].

OBJECTIVE: To approach the effects on induction of differentiation of Tca8113 cells affected by abscisic acid. METHODS: The changes of surface differentiation markers, cell configuration, restrain of cell growth and the expression of Caspase-3 mRNA were examined by using inverted-phase contrast microscope, immunohistochemistry (IHC) and in situ hybridization in vitro. The dependablity between the surface differentiation markers and Caspase-3 mRNA was analysed. RESULTS: The restraint of cell growth in ABA groups was higher than that of the control group (P<0.05). There was a trend that the tumor cell had transformed the normal cell. Furthermore, the time-dosage dependent relationship existed in the inhibition rate of tumor cells. The results showed that the expressions of Involucrin protein, retinoic acid receptor beta (RARbeta) and Caspase-3 mRNA in experimental group had been higher than that of control group. There was a significance between the different concentration experimental groups at 24 h (P<0.05). Moreover, the positive correlation existed among the Involucrin, RARbeta and Caspase-3 mRNA at the time of 12 hour and 24 hour (P<0.05). CONCLUSION: The possible mechanism is that abscisic acid acted on the tumor cell and raised the level of RARbeta gene through combining the correlative receptors so that increased the expression of Involucrin protein and promoted the activity of Caspase-3 and resulted in apoptosis of tumor cell.

Malignant sublingual gland tumors: a retrospective clinicopathologic study of 28 cases.

OBJECTIVES: To evaluate the clinicopathologic features and therapeutic efficacy of malignant sublingual gland tumors. PATIENTS AND METHODS: From 1955 to 2005, the clinicopathologic data of 28 patients treated in our hospital were obtained from their medical records and histopathologic slides. RESULTS: There were 16 males and 12 females, with a mean age of 50.3 years. Eighteen cases (64.3%) were adenoid cystic carcinoma; 16 (57.1%) cases were clinically staged as III-IV. Adenoid cystic carcinoma was mainly of the histologic type, and the other histologic classifications included mucoepidermoid carcinoma, myoepithelial carcinoma, polymorphous low-grade adenocarcinoma, adenocarcinoma and malignant pleomorphic adenoma. Pulmonary metastasis and tumor recurrence were the main death reasons. Eleven patients remain alive and well 34-312 months (median 108) after treatment. CONCLUSIONS: Malignant sublingual gland tumors are extremely rare and most are adenoid cystic carcinoma. Surgery is the main treatment option. For adenoid cystic carcinoma, hematogenous spread is common, and pulmonary metastasis is a common pathway of the distant metastasis. For some patients having lung metastasis, regional control is also important as there are some examples of patients surviving many years with asymptomatic pulmonary metastases. Postoperative radiation therapy may be adjuvant for selected patients with high-stage and high-grade tumors, or when there is concern about the inadequacy of the resection. The effect of chemotherapy remains elusive.

[Diagnosis and surgical approach of parapharyngeal space neoplasms].

PURPOSE: The aim of this study is to investigate the diagnosis and reasonable surgical approach for parapharyngeal space neoplasms. METHODS: A retrospective study was carried out from the data of 24 patients, who suffered from paralaryngeal space neoplasms and underwent surgical treatment from 1998 to 2006. The follow- up was carried out from 1 to 10 years. RESULTS: The patients had no specific symptoms initially. Most patients visited the doctor with cervical or submandibular masses and some of them with disorders of swallowing or speech. 87.5% of the neoplasms were benign and 12.5% were malignant. Neurogenic tumors and tumors originating from the parotid gland accounted the most. CT or MRI provided useful information such as their sizes, shapes, extents and the relationship between the neoplasm and surrounding tissues. The trans-cervical approach was used in 10 cases, the trans-parotid approach in 10 cases, the trans-mandible approach in 4 cases. One patient was dead, two patients were lost to follow up, the others had been cured without recurrence. CONCLUSIONS: CT and/or MRI are essentially useful tools for diagnosis and presurgical planning. Based on the trans-cervical approach, according to the size, origination and nature of the neoplasms, choose of the trans-parotid or the trans- mandibular approach for surgical treatment is reasonable. Supported by Natural Scientific Research Plan of Shanxi Province of China [Grant No.2006k09-G3(5) and 2005K14-G8(2)].

[Cancer stem cells: its existence, proliferation and differentiation in an adenoid cystic carcinoma cell line].

OBJECTIVE: To investigate the evidences of the presence of tumor stem cells and its impact on the tumorigenesis of adenoid cystic carcinoma cell (ACC)-2 cell line by analyzing the biologic characteristics of different sub-clones of adenoid cystic carcinoma cell line. METHODS: In vitro individual cell culture was employed to observe the proliferating character of ACC-2 cells. The expression of CD44(+) and CD24(-) of ACC-2 cells were investigated by immunohistochemical. Immunomagnetic isolation of different phenotype of ACC-2 cells, followed by cell culture, was used to study the proliferating abilities of different clusters of the cell line. The hetero-transplanted tumor mold was established using BALB/C nude mice by subcutaneous injection of tumor cells. The tumorigenic and differentiating properties of the different cluster were investigated. RESULTS: Only 4.41% of cultured ACC-2 cell had ability of division, proliferation and establishment of cell clone. CD44(+)-CD24(-) cluster accounted for about 8.1% of total ACC-2 cells, among which, 25.71% cells could divide and proliferate. All of CD44 and CD44(+)-CD24(+) cells were failure to be eternal alive in the condition of in vitro individual cell culture. According to the results of in vivo tumorigenic study, the minimal cell quantity to develop a subcutaneous transplanted tumor by CD44(+)-CD24(-) cells was 1 x 10(3), where as the needed cell amount were 1 x 10(5) and 1 x 10(4) as to non-isolated ACC-2 cells and CD44(+) cells, respectively. The CD44(-) and CD44(+)-CD24(+) did not develop transplanted tumors. CD44(+)-CD24(-) ACC-2 cell could differentiate into cells of other phenotypes. CONCLUSIONS: CD44(+)-CD24(-) ACC-2 cells consist of a very small portion of all ACC-2 cells (about 4%). They have remarkable proliferating ability and can bear special phenotypes, The tumorogenic ability of CD44(+)-CD24(-) cells are stronger than that of CD44(+) and non-isolated ACC-2 cells. Eliminating of this cluster from ACC-2 would actually deprive the tumorogenic ability of the cell line.

[A retrospective clinicopathologic study of 30 cases of sublingual gland malignant tumors].

OBJECTIVE: To assess the clinical and histological features and therapeutic efficacy of 30 cases of malignant sublingual salivary gland tumors. METHODS: The clinicopathologic data of 30 patients with malignant sublingual salivary gland tumor were obtained from West China Hospital of Stomatology, Sichuan University from 1955 to 2005. RESULTS: There were 18 male and 12 female, and the average age of patients was 50.6 years old. Seventeen cases were adenoid cystic carcinoma, accounting for 56.7%. There were 17 cases clinically staged as III, accounting for 56.7%. Distant metastasis and tumor recurrence were the main death reasons. The overall local recurrence rate was 30.0%, and distant metastasis rate was 26.7%. CONCLUSION: Sublingual gland malignant tumors are rare and most of them are adenoid cystic carcinoma. Surgery is the main treatment option. The resection of the tumor accompanying with the neck dissection is the key method to achieve good therapeutic effect. The postoperative radiotherapy and chemotherapy should be adjuvant.