Objective:To study the effects of isoproterenol(Iso) on the proliferation of cultured submandibular gland cells of SD rats. Methods:Submandibular gland cells of SD rats were primarily cultured. The cells were exposed to Iso at 10 -3 g/L continuously for 8 days or intermittently(2 h each day for 8 days). The cell proliferation was sutdied by bromodeoxyuridine Brdu labeling and cell counting.Results:Iso increased cell proliferation(P

Objective To investigate the clinical,MRI and pathological features of supratentorial primitive neuroectodermal tumor(PNET).Methods The clinical manifestations of 21 PNET patients were analyzed,the skull imaging examination were taken,including MRI with diffuse weighing imaging(DWI) and measured apparent diffusion coefficient(ADC) of tumor and its edema zone before surgery.After operation,the brain tumor tissues were routine and immunohistochemical staining.The relationship between the histopathologic changes and ADC were analyzed.Results In the group,the age of onset of 11cases(52%) were below 20 years old.Clinical manifestation include headache,dizziness and vomiting(16 cases),visual disorder(5 cases),dysosphresis or epilepsy(3 cases).MRI showed single PNET lesion in all the cases and which located at each brain region,the most of them were located at frontal,temporal,parietal lobes(18 cases),and could growing to cross a brain region.MRI T1WI showed that the lesions were iso-signal and lowiso-signal in 15 cases,interspersed high signal in 6 cases.T2WI showed that the lesions were iso and high mixed signal companing capsule change and necrosis,4 cases with lighter tumor edema,5 cases with vascular air flow sign.The imaging enhanced tumors showed uneven enhancement,and 4cases with meningeal tail sign.The pathological examination showed that PNET cell form was main differentiated to neuron(10 cases) and neuroglia(8 cases).There was no statistical significance between ADC and different cell differentiation.Immunity histochemistry showed that the positive of NSE,Syn and GFAP were more offen.Conclusions In the group,the age of onset is below 20 years old.Manifestations of supratentorial PNET are intracranial pressure incresing,visual disorder and dysosphresis.MRI features are mixed isgnal,vascular air flow sign and meningeal tail sign in the tumor.The tumor edema is lighter.The tumor is differentiation mainly toward nerurons and neuroglias in the pathology.There is no positive relationship between ADC and types of tumor differentiation.

Objective: To observe HLA DR expression in different s tages of oral squamous cell carcinoma (OSCC) and to study the clinic significan ce of the abnormal HLA DR expression in primary OSCC. Method: HLA DR expression was detected by immunohistochemistry method in 26 cas es of histologically normal oral epithelia, 8 leukoplakia, 32 primary focuses an d 12 metastasis focuses of OSCC. Results: HLA DR express ion in primary OSCC focuses was significantly higher than that in normal epithel ium( P 0.05). Conclusion: Although HLA DR expression is frequently obs erved in the development of OSCCs, it can not be regarded as one of the indepen dent prognosis factors.

s Objective: To study the feasibility of allogeneic tra ns plantation of myoblasts of SD rats for the reconstruction of facial muscle de fects. Methods: Myoblasts obtained from the forelimbs and hindlimbs of neonatal SD rats were purified and cultured. 5?10 4 myoblasts w ere seeded onto each of type Ⅰcollagen sponges in the size of 1.5 mm?0.8 mm? 0.5 cm. The myoblasts/sponge constructs were transplanted into the facial muscl e defects of syngeneic mutured rats and observed with microscopy,immunohistoche mistry and electromyography (EMG).Result:Myoblasts attac hed and kept alive on type I collagen for at lest 3～4 days in culture. 4 and 8 w eeks after transplantation,muscle like tissue with blood vessles was observed i n the implants. Expression of actin and myosin in the implants was similar to th at in the control muscle.8 weeks after implantation,the spike wave (mV) on the g rafted side and control side was 0.7?0.3 and 2.7?0.6 ( P

Objective:To prepare an acellular matrix from trachea of rabbits and SD rats, and to investigate its biocompatibility.Methods: A modified detergent and enzyme link extraction procedure was performed to remove cells from the trachea of SD rats and rabbits. The histology, topography of inner-surface and biocompatibility were studied by morphological observation,cell culture and in vivo transplantation respectively.Results:The acellular trachea matrix did not inhibit the growth and amylase secretion of allogenic salivary gland cells cultured on it.The allogenically transplanted acellular trachea matrix did not result in inflammation reaction of the host tissue,could integrate with surrounding tisses.Conclusion:The acellular trachea matix is biocompatible.

OBJECTIVEThis study aimed to explore further the mechanisms of tongue squamous cell carcinoma (TSCC) cell recurrence, metastasis, and diffusion, as well as to establish the experimental basis for the molecular biology research on TSSC. We intend to complete our objective through differential proteomics and preliminary analysis protein expression of exosomes derived from TSCC and normal mucosa cells.

METHODSWe acquired cultured supernatant fluid in vitro in the laboratory by culturing TSCC (tongue cancer Tca8113 cell line) and human normal mucosa cells (HOK cell line). The exosomes were separated and purified through differential centrifugation. Furthermore, the different protein expressions were identified through dielectrophoresis and mass spectrometry. The functions of the different protein expressions were identified through an online database search.

RESULTSTSCC and human normal mucosa cells secrete a large amount of capsule bubble structure substances in vitro, as confirmed by electron microscopy and surface markers heat shock protein-70 and major histocompatibility complex class 1. A total of 16 oral cancer cell-derived exosomes that expressed quantity more than two times, twelve that increased their expression levels, and four that cut their expressions were identified through the differential proteomics research on the two groups.

CONCLUSIONDifferential proteins that were verified through the online database serve an important function in exosome formation and in the progress of cancer.

The innovative experiment programs are important teaching reform for improving the students' innovating spirit and practical ability.The innovative experimental studies for medical students in preclinical stage include scientific research topic selection,information retrieval,experimental study and manuscript preparation.The innovative experiments stimulated the research interests,improved the comprehensive quality and promoted the learning of preclinical theories.However,the supporting rules,the assessment methods and the quality of teachers remain to be further improved in order to execute the programs more successfully.

BACKGROUND: An important initial step in developing a tissue engineering artificial salivary gland organoid is to find an ideal scaffold. To find other new biomaterials should to be further studied.OBJECTIVE: To obtain an acellular matrix from tracheae of rabbits and SD rats, and to investigate its biocompatibility as a primary step toward developing a tissue engineering artificial salivary gland organoid.DESIGN, TIME AND SETTING: A randomized controlled animal study, which was performed at the Key Laboratory of Transplantation Engineering and Immunology of Ministry of Health, West China Hospital of Sichuan University from February 2003 to May 2005.MATERIALS: A modified detergent and enzyme link extraction procedure was performed to remove cells from SD rats and rabbits tracheae. The histology, topography of inner-surface and biocompatibility were studied on both acellular tracheae.METHODS: Eighteen SD rats were randomly divided into 2 groups. One group was planted acellular trachea of SD rats. Other group consisted of acellular trachea of rabbits. On the third generations, submandibular gland cells were inoculated on two acellular tracheae and cultured on PGA membrane; while, cells in the control group were inoculated on 12-well culture plate, and cell/scaffold complex was cultured at the same time.MAIN OUTCOME MEASURES: The structure and topography of inner-surface of the acellular tracheae matrixes were observed both by light and scanning electron microscopy. The inflammatory response of the tissue around acellular tracheae implanted under the skin of cheek was evaluated at 1, 4, 12 weeks. The numbers of cells grown on the acellular tracheae and PGA film were counted at 1, 2, 3, 4, 5, 6, 7 days. At 1, 3, 5, 7 days, the mean values of metabolic activity test and the amylase activities of supernatants of the cells/scaffold complexes were examined.RESULTS: The cells were completely removed from both tracheae. No evident inflammatory response was found in tissues around two kinds of acellular tracheae implanted under the skin of cheek. The number of submandibular gland cells (SSG) grown on the two kinds of naturally derived biomaterials was much more than grown on PGA (P<0.05). The mean values of metabolic activity test and the amylase activities of supernatants containing cell/acellular matrixes were much higher than that of cell/PGA (P<0.05).CONCLUSION: The acelhilar tracheae matrixes made by our laboratory can be used as scaffold in the study of tissue engineering artificial salivary gland organoid.

Objective To assess the value of dual-source computed tomography angiography (DSCTA)in detecting intracranial aneurysms by comparing with conventional and three-dimensional DSA.Methods In this study,95 patients with subarachnoid hemorrhage(SAH)underwent both DSCTA and DSA examination.The detection rate,size,and ratio of the neck to the dome(N/D ratio)of the aneurysrns were evaluated.Statistical analysis was performed using a paired sample Student's t-test for the comparisons of the value of N/D and 2 Related Samples test for long axis.Results A total of 67 aneurysms in 63 patients at DSA and 64 aneurysms in 60 patients at DSCTA were detected,respectively;whereas no aneurysm was detected in 32 patients at DSA.Compared with DSA,the overall sensitivity.specificity,positive predictive value,and negative predictive value of DSCTA on a per-aneurysm basis were 94.2%,100.0%,100.0%,and 91.4%,respectively.For the aneurysms larger than 3 mm,the sensitivity and specificity of DSCTA in detecting intracranial aneurysms were equal to those of DSA:For aneurysms smaller than 3 mm,however,the sensitivity and specificity of DSCTA is 80.0% and 100.0%.The N/D ratio for DSA and DSC:TA was 0.46±0.14 and 0.51±0.18.respectively,and the median of long axis was 4.9 mm and 4.8 mm.respectively.There was no significant difierence in the N/D ratio(t=3.20;P＞0.05)and the long axis(Z=-1.309;P＞0.05)between DSA and DSCT.Condusions Compared with conventional and three-dimensional digital subtraction angiography,DSCTA has high sensitivity and specificity in the detection of intracranial aneurysms,especially for detection of snlall aneurysnm(＜3 mm).It can be used as a routine screening technique.

Objective Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a novel functional imaging tech-nique for assessing the property of the tissue vessel .This study was to investigate whether DCE-MRI can manifest the angiogenesis of pri-mary liver cancer in the aspect of vascular permeability so as to provide more objective diagnostic information for the evaluation of primary liver cancer . Methods Twenty-one patients with primary liver cancer underwent DCE-MRI.The region of interest ( ROI) was placed in the whole tumor, the hot spot of the tumor and the adjacent liver parenchyma .Tissue 4D software package was used for the post-pro-cessing of the DCE-MRI images, the quantitative parameters including transfer constant (Ktrans), rate constant (Kep) and tumor extravas-cular extracellular space volume (Ve), and such semi-quantitative parameter as the initial area under the contrast concentration versus time curve (iAUC). Results The mean Ktrans, Kep, Ve and iAUC values were (0.124 ±0.057)/min, (0.632 ±0.158)/min, (0.205 ±0.098) and (10.009 ±6.201) in the adjacent liver parenchyma , (0.196 ±0.109)/min, (0.546 ±0.214)/min, (0.424 ± 0.160) and (13.675 ±6.113) in the whole tumor, and (0.422 ±0.170)/min, (0.780 ±0.308)/min, (0.589 ±0.116) and (35.663 ±19.086) in the hot spot of the tumor .All the parameters were significantly higher in the hot spot of the tumor than in the whole tumor (P<0.05), and so were Ktrans and Ve in the whole tumor than in the adjacent liver parenchyma (P<0.05), but Ktrans, Ve, and iAUC were markedly lower in the adjacent liver parenchyma than in the hot spot of the tumor (P<0.05). Conclusion Analysis of the vascular permeability of the tissue using DCE-MRI parameters can indirectly reflect the angiogenesis of the tumor and contribute to the evaluation of primary liver cancer , while monitoring the DCE-MRI pa-rameters of the hot spots of the tumor may allow more accurate evalua-tion of primary liver cancer .