In vitro targeting efficiency evaluation of reduction-responsive co-loaded doxorubicin/siRNA nanoparticles / 药学学报

In this study a reduction-responsive nanoparticles (NPs) modified with hyaluronic acid (HA) was prepared for the co-delivery of doxorubicin (DOX) and siRNA and then evaluated as a lung cancer targeting delivery system in vitro. The amphiphilic polymer of poly-L-lysine-lipoic acid (PLA) based on poly-L-lysine (PLL) with lipoic acid (LA) was synthesized via amidation reaction and characterized by 1H NMR. The DOX loaded PLA NPs were prepared via dialysis method, and siRNA was loaded via electrostatic attraction to prepare the co-delivery NPs system (PLA/DOX-siRNA-NPs). Then PLA/DOX-siRNA-NPs were coated with HA to obtain HA-PLA/DOX-siRNA-NPs. The tumor microenvironment-responsive properties under different pH or reduction condition of HA-PLA/DOX-siRNA-NPs were evaluated by investigating the particle size and zeta potential. Cellular uptake of HA-PLA/DOX-siRNAFAM-NPs by A549 cells and endosomal escape of siRNA were studied using confocal laser scanning microscope (CLSM). 1H NMR spectrum demonstrated that PLA was successfully synthesized with LA grafting rate of 25.1%. The encapsulation efficiency (EE) and drug loading (DL) of HA-PLA/DOX-NPs was (86.93±8.91)% and (4.17±0.68)%, respectively, and siRNA was loaded at an N/P of 6:1 in carrier. HA-PLA/DOX-siRNA-NPs exhibited a suitable size of (167.3±9.9) nm and negative charge of (-15.5±1.4) mV with the optimal ratio of PLA and HA of 1:3. Additionally, the zeta potential of HA-PLA/DOX-siRNA-NPs significantly increased with charge reversal from negative to positive after the treatment with HAase, and the particle size of HA-PLA/DOX-siRNA-NPs changed significantly under the condition of 10 mmol·L-1 glutathione (GSH). The release profiles in vitro demonstrated that HA-PLA/DOX-NPs exhibited a maintained release behavior at pH 7.4 and the adding of GSH (10 mmol·L-1) led to rapid release of DOX from NPs. In vitro cellular uptake and subcellular distribution study demonstrated that themodification of HA enhanced the affinity of NPs to A549 cells and targeting ability, and the cellular uptake of HA-PLA/DOX-siRNAFAM-NPs significantly increased after the treatment with HAase. It was observed that HA-PLA/DOX-siRNAFAM-NPs could escape from endo-lysosomes followed by sharp payloads release to their relative targets. All these results demonstrated that the co-loaded NPs have a high entrapment efficiency of DOX and siRNA. And they also exhibited an active tumor targeting efficiency and tumor microenvironment-responsive properties, which were beneficial to cellular uptake and intracellular release of DOX and siRNA. In conclusion, these reduction-responsive NPs modified with HA have great potential as co-delivery systems for antitumor agents and siRNA.

Serum Uric Acid Relation for Hearing Threshold Shift

OBJECTIVES: The effects of serum uric acid (UA) level on a variety of diseases were found from experimental and observational studies via oxidative stress and anti-oxidants. However, research on the association of UA and hearing thresholds is relatively sparse. We investigated this issue in the U.S. general population to evaluate the relationship of serum UA levels and pure tone threshold of hearing. METHODS: Forty four thousand eighty four eligible participants aged 20 to 69 years who have serum UA data and received Audiometry Examination Component were enrolled from the National Health and Nutrition Examination Survey 1999–2004. Hearing thresholds (dB) as a pure tone average at low frequencies (0.5, 1, 2 kHz) and at high frequencies (3, 4, 6, and 8 kHz) were computed. Multivariate linear regression models and tertile-based analysis with an extended-model approach for covariates adjustment were used to assess the correlation between serum UA level and hearing thresholds. RESULTS: In the adjusted mode of tertile-based analysis, the regression coefficients elucidated as the change of log-transformed mean hearing thresholds upon comparing participants in the highest tertile of serum UA to those in the lowest tertile were –0.067 (P=0.023) in high frequency and –0.058 (P=0.054) in low frequency. After adjusting for multiple pertinent covariates, inverse association between tertiles of serum UA and hearing thresholds remained essentially unchanged. The negative trends between serum UA and hearing thresholds were statistically significant (P for trends <0.05) in tertile-based multiple linear regressions. CONCLUSION: Individuals with elevated UA levels independently were found to be inversely associated with hearing thresholds for pure tone audiometry in a nationally representative sample of U.S. adults.

Clinical study of submental artery island myocutaneous flap for reconstruction of oral and maxillofacial defects following operation / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the outcome and indication of the reconstruction of oral and maxillofacial postoperative defects by submental artery island myocutaneous flaps.</p><p><b>METHODS</b>Sixty eight cases with the reconstruction of oral and maxillofacial defects by submental artery island myocutaneous flaps from January 2006 to May 2010 were analysed retrospectively. Primary lesions included carcinomas originating from tongue (28 cases), palate (13 cases), mouth floor (9 cases), gingiva (4 cases), buccal mucosa (6 cases), lip (3 cases), and other malignant or benign tumors (5 cases). The ages ranged from 25 to 84 years (mean 58 years); 47 males and 21 females. The sizes of skin paddle varied from a minimum of 4 cm × 4 cm to a maximum of 15 cm × 10 cm.</p><p><b>RESULTS</b>Of the 68 flaps, 62 were survival, 4 had partial necrosis but healed with treatments, and 2 failed due to complete necrosis. Appearance and functions of recipient sites were satisfactory. The followed-up time was 3 - 24 months, local recurrence occurred in 5 cases and cervical lymph node metastases were found in 15 patients.</p><p><b>CONCLUSION</b>Submental island flap is reliable for the reconstruction of postoperative defects in early oral cancer without regional lymph node metastasis or in benign tumor.</p>

A review of clinical and histological parameters associated with contralateral neck metastases in oral squamous cell carcinoma / 国际口腔科学杂志·英文版

Oral squamous cell carcinoma (OSCC) has a high incidence of cervical micrometastases and sometimes metastasizes contralaterally because of the rich lymphatic intercommunications relative to submucosal plexus of oral cavity that freely communicate across the midline, and it can facilitate the spread of neoplastic cells to any area of the neck consequently. Clinical and histopathologic factors continue to provide predictive information to contralateral neck metastases (CLNM) in OSCC, which determine prophylactic and adjuvant treatments for an individual patient. This review describes the predictive value of clinical-histopathologic factors, which relate to primary tumor and cervical lymph nodes, and surgical dissection and adjuvant treatments. In addition, the indications for elective contralateral neck dissection and adjuvant radiotherapy (aRT) and strategies for follow-up are offered, which is strongly focused by clinicians to prevent later CLNM and poor prognosis subsequently.

Reconstruction of tongue defects following oral cancer ablation with extended supraclavicular fasciocutaneous island flap / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To assess the reliability and usefulness of the extended supraclavicular fasciocutaneous island flap (eSIF) for reconstructing soft tissue defects followinng tongue cancer ablation.</p><p><b>METHODS</b>Twenty-two tongue defects in 22 patients with tongue cancer were repaired with eSIF after resection of the tongue malignant tumours. The sizes of the skin paddle ranged from (4 cm × 6 cm) to (8 cm × 14 cm) (average: 5.5 cm × 8.7 cm).</p><p><b>RESULTS</b>The eSIF survived in twenty cases, including two cases with minimal partial necrosis. The patients were follwed up for 5 - 16 months. Eighteen patients were alive with disease free, two were alive with disease and two died of a lung and liver metastasis.</p><p><b>CONCLUSIONS</b>The eSIF is reliable for reconstructing oral defects following the ablation of advanced oral malignant tumors.</p>

Application of multislice spiral CT and 3D reconstruction in diagnosis and treatment of vascular malformations in head and neck / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the application of MS-CT and 3D reconstruction in diagnosis and treatment of vascular malformations in head and neck.</p><p><b>METHODS</b>20 cases with vascular malformations in head and neck underwent MS-CT and 3-D reconstruction. Then the treatment was determined based on the results of MSCT scanning. The postoperative results were evaluated.</p><p><b>RESULTS</b>The images of MS-CT showed the edge of vascular malformations partially or completely in 16 cases of venous malformations. The lesion's anatomic site and 3-D position was obtained. The 3-D images also showed the overexpanded supply arteries in 4 case of arteriovenous malformations. 2 case of venous malformations in lip underwent resection and healed completely. 12 cases of venous malformations in buccal and floor of mouth were treated with compartmentalized sclerotherapy with partial lesion involution. 2 case of venous malformations in mouth floor were treated with operation followed by sclerotherpy with partial lesion involution. 4 cases of arteriovenous malformations were treated with Superselective Artery Embolization with partial lesion involution.</p><p><b>CONCLUSION</b>MS-CT and 3D reconstruction can play an important role in diagnosis and treatment of vascular malformations in head and neck.</p>

Effects of Ezrin gene on the proliferation and invasion activity of human salivary gland adenoid cystic carcinoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To examine the expression of Ezrin in human salivary gland adenoid cystic carcinoma and investigate the effects of Ezrin gene silence on cell proliferation, apoptosis and invasion of adenoid cystic carcinoma (ACC)-M.</p><p><b>METHODS</b>The expression of Ezrin was detected by immunohistochemistry in normal salivary gland tissue (n=15), pleomorphic adenoma (n=40) and salivary gland adenoid cystic carcinoma (n=43). The Ezrin Stealth RNAi Duplex, containing Stealth RNAi Negative Control Duplex were constructed and transfected into ACC-M cells by Lipofectamine 2000. The expression levels of Ezrin were detected by RT-PCR and immunohistochemistry. The cell cycle and apoptosis rate were analyzed by flow cytometry (FCM). The cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) and cell invasion by Transwell test.</p><p><b>RESULTS</b>The positive rate of Ezrin expression in ACC was significantly higher than that in normal salivary gland tissue and pleomorphic adenoma (P<0.05). After transfection of Ezrin Stealth RNAi Duplex, the mRNA and protein expression of Ezrin were down-regulated, the cell proliferation activity was inhibited, the G0-G1 Phase cells were increased, and the apoptosis rate of Ezrin Stealth RNAi Duplex group was higher than that in control groups and cell invasion ability was decreased.</p><p><b>CONCLUSIONS</b>Over expression of Ezrin in human salivary gland adenoid cystic carcinoma may promote genesis, development and metastasis of tumors. Ezrin Stealth RNAi Duplex could efficiently down-regulate the expression of Ezrin gene, and partly inhibited proliferation of ACC-M cells, induce apoptosis and decrease invasion ability of these cells in vitro.</p>

Impacted lower third molar fused with a supernumerary tooth--diagnosis and treatment planning using cone-beam computed tomography / 国际口腔科学杂志·英文版

This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography-which provides precise three-dimensional information-was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomography.

Mental neurovascular V-Y island advancement flap in functional reconstruction of partial lower lip defect / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the functional reconstruction technique for partial lower lip defects.</p><p><b>METHODS</b>7 patients with lower lip cancer (3 cases of basal cell carcinoma, 2 cases squamous cell carcinoma and 2 cases papillary carcinoma) underwent excision. The full-thickness lower lip defects were one-third to two-third of the total lower lip length. All the defects were reconstructed with V-Y island advancement flaps based on the mental neurovascular bundle.</p><p><b>RESULTS</b>There was no flap loss. No recurrence was observed during the follow-up period of 3 months to one year. Both the aesthetic appearance, muscle function and sensation of the reconstructed lower lip were satisfactory.</p><p><b>CONCLUSIONS</b>Mental neurovascular V-Y island advancement flap is an ideal method for functional repair of partial lower lip defect.</p>

Influence of iNOS silencing by RNA interference on proliferation activity of Tca8113 cell / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the apoptosis and proliferation activity of Tca8113 cells.</p><p><b>METHODS</b>The vector that involves short hairpin RNA of iNOS was transfected to Tca8113 cells. The change of iNOS expression was observed using immunohistochemistry technique, the apoptosis rate examined by flow cytometry, and the proliferation Tca8113 cells examined by methyl thiazolyl tetrazolium (MTT).</p><p><b>RESULTS</b>The expression of iNOS in Psilencer-iNOS group was lower than that in control groups (P < 0.01), the apoptosis rate was higher than that in control groups (P < 0.01); whereas the proliferation activity of Tca8113 cells in Psilencer-iNOS group was lower than that in control groups.</p><p><b>CONCLUSIONS</b>Down expression of iNOS by RNAi can promotes apoptosis of Tca8113 cells and has an anti-proliferation activity effect.</p>

Reverse facial artery-submental artery island myocutaneous flap for reconstruction of oral and maxillofacial defects following cancer ablation / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the reliability of the reverse facial artery-submental artery island myocutaneous flap for repairing the oral and maxillofacial defects.</p><p><b>METHODS</b>Eighteen oral and maxillofacial defects were repaired with reverse facial artery-submental artery island myocutaneous flaps following resection of malignant tumors. The ages of the patients ranged from 28 to 90 years; 11 were male and 7 were female. Primary sites of the lesions were the tongue squamous cell carcinoma (SCC) (7 cases), buccal mucosa SCC (4 cases), palate SCC (3 cases), oropharyngeal SCC (2 case), and facial skin basal cell carcinoma (2 cases). The sizes of skin paddle varied from a minimum of 4.0 cm x 12.0 cm to a maximum of 5.0 cm x 15.0 cm. The followed-up period was 9 to 18 months (11.8 months on average).</p><p><b>RESULTS</b>The postoperative outcome for the flaps was 17 cases surviving, one complete necrosis, and one temporary palsy of the marginal mandibular branch of the facial nerve. The form and function of recipient sites were well recovered. The donor site left a well-hidden scar. One case of cervical lymph node metastasis was observed.</p><p><b>CONCLUSIONS</b>Reverse facial artery-submental artery island myocutaneous flap is reliable for reconstructing medium-sized oral and maxillofacial defects.</p>

Lower trapezius myocutaneous flap for repairing defects in head and neck region / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the anatomy basis and clinical effects of the lower trapezius myocutaneous flap to reconstruct defects in the head and neck.</p><p><b>METHODS</b>From Jan. 2000 to Jan. 2004, lower trapezius myocutaneous flaps which were used to reconstruct the defects in the head and neck after radical tumors resection in twenty four cases in Center of Craniomaxillofacial Surgery of the Second Affiliated Hospital of Sun Yat-sen University were analyzed retrospectively. Male was 14,female was 10. Ages ranged from 35 to 76 (median = 54). The causes of the defects were malignant neoplasm of the tongue (n = 10), buccal (n =4), oral floor (n = 2), parotid (n = 1 ), oropharynx (n = 2), gingiva (n = 3), maxillary sinus (n = 1), zygomatic and frontal part (n = 1). Fifteen patients were primary, nine patients were recurrent. The flaps ranged from 8 cm x 7 cm to 12 cm x 10 cm.</p><p><b>RESULTS</b>Twenty one flaps survived fully and the other three had partial necrosis at the distal portion. Twenty two donor sites were closed primarily. Follow up 6 to 24 months, all flaps were good, the texture and color of the flaps were satisfying.</p><p><b>CONCLUSIONS</b>Lower trapezius myocutaneous flap is a thin, pliable and simple myocutaneous with a long pediculi and wide arc of rotation, and it is preferred for reconstructing huge soft-tissues defects in the head and neck regions simultaneously.</p>

Study on the inhibition of vascular endothelial growth factor expression in Tca8113 cell by inducible nitric oxide synthase gene RNA interference / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of inducible nitric oxide synthase (iNOS) on vascular endothelial growth factor (VEGF) expression.</p><p><b>METHODS</b>The vector containing short hairpin RNA of iNOS was transfected into Tca8113 cells using the RNA interference (RNAi) technique. The gene and protein expression of iNOS and VEGF was examined by RT-PCR and Western blot.</p><p><b>RESULTS</b>The expression of iNOS, VEGF gene in Tca8113 cells was significantly different between the experimental and control groups 24 h and 48 h after transfection (P < 0.05). The protein expression of iNOS was different between the two groups 36 h and 48 h after transfection, and of VEGF was also different between the two groups 48 h after transfection (P < 0.05).</p><p><b>CONCLUSIONS</b>The expression of VEGF could be down-regulated by silencing the iNOS gene in Tca8113 cells.</p>

Relationship between expression of inducible nitric oxide synthase and proliferative potency of endothelium in hemangioma in infants / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate relationship between expression of inducible nitric oxide synthase (iNOS) and proliferative potency of endothelium in hemangioma (HM).</p><p><b>METHODS</b>Immunohistochemical staining was used to detect expression of iNOS and Ki-67 protein in 49 cases of HM and 29 cases of vascular malformation (VM).</p><p><b>RESULTS</b>Expressive rate of iNOS and Ki-67 protein of 49 cases of HM was 38% and (10.98 +/- 7.93)%. Expressive rate of iNOS and Ki-67 protein of 29 cases of VM was respectively 3% and (0.03 +/- 0.19)%. The expressive rate of iNOS and Ki-67 protein of HM was significantly higher than that of VM (P = 0.001 and 0). The expressive rate of Ki-67 protein of HM of proliferative phase was (12.67 +/- 7.65)% , which was significantly higher than that of HM of extinctive phase, (7.27 +/- 7.49)% (P = 0.028).</p><p><b>CONCLUSIONS</b>Expression of iNOS and Ki-67 protein of HM is significantly higher than that of VM, and the proliferative potency of HM is significantly higher than that of VM.</p>

Extended lower trapezius myocutaneous flap for repair of defects after resection of recurrent oral carcinoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To explore an effective repairing method for oral and maxillofacial soft-tissue defects after resection of recurrent oral carcinoma.</p><p><b>METHODS</b>Six patients with recurrent oral squamous cell carcinoma (R-OSCC) of tongue (n = 2), oral cavity floor (n = 2) and buccal (n = 2) were treated with salvage surgery and the oral and maxillofacial soft-tissue defects were repaired primarily by extended lower trapezius island myocutaneous flap (TIMF).</p><p><b>RESULTS</b>No flap failure occurred. The donor sites were primarily closed. There were no disabilities with regard to shoulder motion. The life period of the patients was 13 to 30 months and the average life period was 22.6 months after the operation.</p><p><b>CONCLUSIONS</b>The TIMF, which is a simple, reliable and large flap can be preferred as a salvage procedure for oral and maxillofacial soft-tissue defects after treatment of R-OSCC.</p>

Plastic surgical treatment of extensive hemangiomas in the oral and maxillofacial regions in children / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate plastic surgical procedures for the extensive soft tissue hemangiomas in the oral and maxillofacial regions in children and to explore prevention methods from surgical complications.</p><p><b>METHODS</b>134 patients with hemangiomas were surgically treated. The defects of soft tissue were repaired with pedicle flaps or skin grafts. Of the 134 patients, 16 were newborns, 91 infant, 16 at preschool age and 11 at school age. The location of hemangiomas included parotid gland (39.6%), lip (20.9%), buccal (20.1%), suborbital (9%), orbital (7.5%) and nasal region (3%).</p><p><b>RESULTS</b>Follow-up from 6 months to 5 years showed that the cure rate was 80.6%, apparently effective rate was 15.7%, effective rate was 2.2% and ineffective rate was 1.5%. No major surgical complications were found.</p><p><b>CONCLUSION</b>Extensive hemangiomas in the oral and maxillofacial regions in children were treated safely using plastic surgical procedures with satisfactory results esthetically and functionally.</p>

Cellular toxic effects of combination of low dose of cisplatin and interstitial injection of 32P glass microspheres on mouse solid tumor S180 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although 32P-glass microspheres (32P-GMS) have been used in internal radiotherapy for malignant tumors, it has been one of the key obstacles to improve the effect of radiotherapy. We investigated the cellular and hypersensitive effect of combined use of low dose of cisplatin and interstitial injection of 32P-GMS on mouse solid tumor S180.</p><p><b>METHODS</b>The mice with solid tumor S180 were randomly divided into four groups (controls, cisplatin therapy, 32P-GMS therapy and combination therapy). The specimens of the mice were sectioned two weeks after treatment and weighed. The death rate of tumor cells and the inhibition rate of tumor were calculated respectively. The cell cycle and apoptosis rate were evaluated with flow-cytometry. The ultrastructural changes of the four groups were observed by a transmission electron microscope. The data were analyzed by the chi-square test.</p><p><b>RESULTS</b>The growth of tumor was slower in the combination therapy group than in the simple therapy groups by macrography. The inhibition rate and the death rate of tumor cells of the combination therapy group were significantly higher than those of the control group and the other two simple therapy groups (P < 0.05). More cell damages were displayed in the combination therapy group than in the other groups under the light and electronic microscope.</p><p><b>CONCLUSION</b>Low-dose cisplatin combined with interstitial injection of 32P glass microspheres could be used as an effective hypersensitive regimen for the internal radiotherapy of mouse solid tumor S180.</p>

An island pectoralis major myocutaneous flap for the reconstruction of tongue and floor of mouth / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate an island pectoralis major myocutaneous flap for immediate reconstruction of the total tongue body and the floor of the mouth after radical resection of bilateral tongue carcinoma involved.</p><p><b>METHODS</b>Form October 2000 to December 2002, seven patients with bilateral tongue carcinoma were selected to treat with salvage surgery, and an island pectoralis major myocutaneous flap were applied for immediate reconstruction of total body of tongue and floor of mouth.</p><p><b>RESULTS</b>Six flaps survived well. Only one flap showed a partial necrosis, with no submandibular fistula, infection, and other complications. The reconstructed tongue and floor of mouth worked well. The speaking and swallowing functions were satisfactory after 2 approximately 16 months' follow-ups. Only one patient died of lung metastasis carcinoma in 9 months after the operation.</p><p><b>CONCLUSIONS</b>The island pectoralis major myocutaneous flap could be an ideal selection for the immediate reconstruction of the total tongue body and the floor of mouth.</p>

Effect of salvage surgery for patients with recurrent oral squamous cell carcinoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To examine the benefit of restaging recurrent oral squamous cell carcinoma (R-OSCC) and the effect on salvage surgery.</p><p><b>METHODS</b>An analysis was performed on 30 patients with local only first failure (n = 13) or loca-regional only first failure (n = 9) or first recurrence in the neck (n = 8) after surgery and/or radiation treatment given for oral squamous cell carcinoma. All the 30 patients were restaged and treated with salvage surgery.</p><p><b>RESULTS</b>The overall survival time and disease-free survival time of patients with early staged R-OSCC was longer than that of patients with advanced staged R-OSCC. The 1-year survival and 1-year disease-free survival rates for early staged R-OSCC is also higher than that of advanced staged R-OSCC.</p><p><b>CONCLUSIONS</b>The re-stage of the recurrent tumor is significantly correlated with survival. The salvage surgery is an effective measure in patients with recurrent oral squamous cell carcinoma, especially in early staged patients of R-OSCC.</p>

Intervention effect of an inducible nitric oxide synthase inhibitor on carcinogenesis of hamster cheek pouch carcinoma / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe the expression changes of VEGF, iNOS and the level of MVD and NO during the evolution of Golden hamster cheek pouch carcinogenesis. To study the effect of NO in carcinogenesis in the pouch of hamster, and to investigate the effect of NOS inhibitor L-NAME in interfering with carcinogenesis.</p><p><b>METHODS</b>90 golden hamsters were divided into three groups: 40 in experiment group, 40 in control group and 10 in blank group. DMBA was painted on hamster's cheek pouch in experiment and control group, L-NAME was given to hamster in experiment group at the dose of 0.02 ml/g. Hamsters were killed at 6, 9, 12 and 16th weeks, respectively. The blank group was killed at the 16th week. SABC immunohistochemistry assay was used to detect the expression of iNOS, VEGF and factor VIII-related antigen. MVD was measured. The level of NO was measured by Spectrophotometry.</p><p><b>RESULTS</b>The difference between control group and experiment group at the 12th week and 16th week was observed. The difference of positive expression rate of iNOS in all group was significant and difference between blank group and control group was significant. The difference of positive expression rate of VEGF in all group was significant and difference between blank group and control group at the 12th and 16th week was significant; there was significant difference in every group MVD from the 6th week control group to the 16th week control. There were significant difference among the control group, except the 6th week of experiment and control group.</p><p><b>CONCLUSION</b>There is an increased expression of iNOS and the level of NO, as well MVD during the evolution of Golden hamster cheek pouch carcinogenesis from slightly dysplasia to invasive carcinoma. NO plays an important role during the evolution of carcinogenesis, and iNOS inhibitor L-NAME can inhibit the carcinogenesis.</p>