OBJECTIVETo modify biomacromolecules, such as chitosan and collagen, to synthesize a mineralized template that will induce self-growing remineralization of tooth enamel.

METHODSNatural polycation polysaccharide chitosan was modified through phosphorylation to synthesize the polyanion derivative ofphosphorylated chitosan. Parent hydrogels com- bined with chitosan and collagen I were built through peptide binding reaction using genipin as a crosslinker. The gels self- assembled on the tooth's inert surface, which was stimulated by ultraviolet radiation. The bionic saliva provided mineralized ion, and then the hydroxyapatite assembled and grew in situ on the tooth.

RESULTSThe functional group P04(3-) (3,446 cm(-1)) was grafted on chitosan as confirmed by the Fourier transform infrared spectroscopy. The porous polyelectrolyte complex hydrogel formed by the interaction between the polycation chitosan and the polyanion phosphorylated chitosan could induce hydroxyapatite crystal nucleation and growth on the hydrogel fiber surfaces. The neonatal crystal was hydroxyapatite as confirmed by X-ray diffraction and was tightly connected to the tooth. A continuous structure of column crystals with sizes ranging from 30 nm to 60 nm was observed. The structure was in parallel direction similar to the direction of the enamel rod, and its hardness was close to dentin.

CONCLUSIONThe parent hydrogels that were easily obtained and controlled could mimic the template of the enamel mineralization and induce a self-growing hydroxyapatite, which is an important step in the structural bionics of enamel.

Biocompatible Materials ; Chitosan ; Collagen ; Dental Enamel ; Durapatite ; Microscopy, Electron, Scanning ; Polymers ; Spectroscopy, Fourier Transform Infrared ; Tooth ; Tooth Remineralization ; Ultraviolet Rays ; X-Ray Diffraction

OBJECTIVETo study and evaluate the clinical effects of combined preoperative chemotherapy and their relations with multi drug resistance (MDR).

METHODS102 cases with oral squamous cell carcinoma(OSCC) were included in the study (63 males and 39 females, aged 22 to 67 years). Among the subjects there were 57 cases with cancer of tongue and 45 cases with cancer of buccal mucosa. 27 cases in the group were classified as stage II, 55 as stage III and 20 cases as stage IV according to TNM standard. All cases accepted PYM + 5-Fu + DDP combined chemotherapy pre-operatively. The total given dose was PYM 48 mg, 5-Fu 7.5 g and DDP 300 mg. After the chemotherapy, radical surgery were performed within 2 weeks. The diagnosis of all cases were proved as OSCC by biopsy.

RESULTSTotal effective rate of the combined chemotherapy was 82.4%. All of the cases were followed up and their 3 years' survival rate was 67.6%.

CONCLUSIONThe combined chemotherapy of PYM + 5-Fu + DDP is effective in using as one of comprehensive treatment for OSCC.

Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Bleomycin ; administration & dosage ; analogs & derivatives ; Carcinoma, Squamous Cell ; therapy ; Cisplatin ; administration & dosage ; Combined Modality Therapy ; Female ; Fluorouracil ; administration & dosage ; Humans ; Male ; Middle Aged ; Mouth Neoplasms ; therapy ; Tongue Neoplasms ; therapy ; Treatment Outcome

OBJECTIVEThe aim of this study was to analyze the clinical characters, diagnosis and treatment of primary neoplasms in the parapharyngeal regions.

METHODSA total of 115 cases of primary neoplasms in the parapharyngeal regions were included in this study.

RESULTSDisorders of swallowing, breath or speaking were the common symptoms of neoplasms in parapharyngeal regions. The majority of neoplasms parapharyngeal regions were benign. 46 cases were from the deep lobe of the parotid, and 42 cases were neurogenic. CT or MRI provides useful information such as their sizes, shapes and extents. The relationship between the tumor and vessel was shown using super-selective angiography. All the tumors were resected completely by extra-oral approach through the posteroinferior incision of the mandible. The follow-up was carried out from 1 to 10 years, and the data indicated that 2 patients died, 18 cases were lost, and others had no recurrence.

CONCLUSIONCT and/or MRI are essentially useful for diagnosis and presurgical planning. Super-selective angiography can be used if the lesions involved carotid artery. Posteroinferior incision of the mandible is a simple, effective and safe approach for excision of neoplasms parapharyngeal regions.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Female ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neurilemmoma ; diagnosis ; pathology ; surgery ; Parotid Neoplasms ; diagnosis ; pathology ; surgery ; Pharyngeal Neoplasms ; diagnosis ; pathology ; surgery ; Retrospective Studies ; Tomography, X-Ray Computed

Objective: To study the changes of TGFβ/Smad signaling expression in oral squamous cell carcinoma (OSCC) after hyperthermia. Methods: The expression of TGFβ, Smad2, 3, 4 and 7 in OSCC of tumor bearing nude mice were examined by quantitative real-time RT-PCR and Western blot respectively. Results: The mRNA expression of TGFβ, Smad2 and 3 was decreased significantly, and the mRNA levels of Smad7 was elevated in hyperthermia (HT) group (n = 10) (P ＜ 0. 05), but the mRNA expression of Smad4 did not change significantly compared with that of control group (n = 10) . The changes of protein expression of TGFβ, Smad7 and 4 were consistent with that of mRNA, the expression of Smad2 and 3 was not significantly different between the groups, but the expression of p Smad2 and p Smad3 decreased dramatically in HT group (P ＜ 0. 05) . Conclusion: TGFβ/Smad signaling exhibits important role in the antitumor effects of hyperthermia, and the inhibition of Smad7 on R-Smad phosphorylation may play a key role.