Interferon y (IFN-?) could enhance the metastatic potential of a variety of tumors via increasing expression of MHC class I molecules or other unidentified mechanisms. It has been demonstrated that transfection of T-cell costimulatory molecule B7 gene into tumor cells could increase tumor immunogenicity and render them susceptible to immune attack. In this study, we investigate whether transfection of B7-1 gene could antagonize IFN-?-induced tumor metastasis. Lipofectamine-mediated transfection was used to introduce murine B7-1 (mB7-1) gene or neo gene into a low-metastatic variant of B16 melanoma cell line. The transfectants and parent B16 cells were treated with 100U/ml of IFN-? for 36 h before being subjected to experimental metastasis assay. The expression of MHC class I and class II molecules on the cells was analysed by flow cytometry. Pre-treatment of parent B16 cells and mock gene-transfected B16 cells (B16-neo) with IFN-? significantly increased their lung-metastizing capacity, while the same IFN-? treatment of B16 cells transfected with mB7-1 gene (B16-B7-1) showed no increase in the number of lung metastatic nodules as compared with control cells. Almost equally elevated expression of MHC class I (H-2Kb and H-2Db) molecules was found on the surface of B16, B16-neo and B16-B7-1 cells. However, a much higher expression of class II (I-Ab) molecule on B16-B7-1 cells than that on B16 and B16-neo cells was observed. These results demonstrate that transfection of B7-1 gene into B16 melanoma could reduce its IFN-?-induced metastasis and that the elevated MHC class II expression on B7-1-expressing cells might play a role in the B7-1 -associated reduction of metastasis.

ObjectiveCurrently,adsorption materials applied to remove low density lipoprotein (LDL) still remain defects.HB-H-8 resin has not been put in use in removing LDL.This study focused on primary evaluation of adsorption capability of HB-H-8 resin.MethodsHB-H-8 resin was used in the adsorption of LDL of patient that was higher than the normal range of blood sample in dynamic test and static test in vitro.ResultsThe time of adsorption saturation was two hours,and the optimum temperature was 37℃.The results of adsorption in vitro showed that the average adsorption rates of LDL and high density lipoprotein (HDL) were 63.2％ and 1.9％,respectively.ConclusionHB-H-8 resin has LDL higher adsorption capability,thus made it to be a potential blood purification material for the removal of LDL.

OBJECTIVE: To discuss the protective effect of captopril on the nicotine-induced impairment of endothelium-dependent relaxation(EDR) in rat mesenteric arteries and explore the possible mechanisms underlying the observed protective effects of captopril.METHODS: A total of 30 rats were randomly divided into 3 groups: normal control group,nicotine group(2 mg?kg-1),captopril group(nicotine 2 mg?kg-1+captopril 3 mg?kg-1).After treatment for 4 weeks,vasodilatation rate of mesenteric arteries,the content of NO and NOS,and the SOD activities in serum were measured.RESULTS: Nicotine significantly decreased the vasodilatation rate of mesenteric arteries and decreased the content of NO and NOS,SOD activities in serum(P

Objective:Observing the mechanism of apoptosis in the carcinoma of urinary bladder BIU 87 cell strain induced by staphylococcus enterotoxin A (SEA).Methods:The multiplicative inhibitory rate of the BIU 87 cell strain and cell cycle affected by SEA was tested with MTT colorimetry and low cytometry.Results:SEA restrain obviously the BIU 87 cell strain and have dosage dependence and obstruct the cell multiplication processes from G 1 period to S period.A crowd of cells was seen G 1 period.Conclusion:SEA having effect of cytotoxicity can make BIU 87 cell strain apoptosis and prevent the metastsis of the carcinoma of urinary bladder by pouring it into bladder.

Septic shock is one of the most serious diseases threatening the critically ill patients in Intensive Care Unit.How to improve the survival rate has now been most concerned and directed by critical care doctors.For that case,it is necessary to summarize and investigate the clinical cases about how to manage elderly patients with septic shock.

BACKGROUND: The investigation of culturing, passaging and establishing human limbal stem cells can strengthen the recognition of the stem cells and provide the enough cellular reserve for the basic and clinical research of limbal stem cell transplantation.OBJECTIVE: To explore a method of pessaging and establishing cell line of human limbal stem cells cultured in vitro.DESIGN: Randomized controlled observation.SETTING: Gannan Medical College.MATERIALS: The experiment was performed at Scientific Center of Gannan Medical College and the National Key Laboratory of Ophthalmology Hospital Affiliated to Sun Yat-Sen University from June 2003 to April 2004. Fresh human limbus corneae were isolated from two healthy donors. Procedures were performed according to the informed consent of the donors. Main reagents contained RPMI-1640 (Sigma R8755, containing L-glutamine) and 200 g/L fetal calf serum (FCS) (Gibco 16140-071). DMEM medium, chondroitin sulfatase and human epidermal growth factor (hEGF) were purchased from Sigma Co. USA; HEPES and DMSO were bought from Gibco, USA; 100% glycerinum was purchased from Yunjia Huangpu Pharmaceutical Product Limited Company, PRC; glutaraldehyde was bought from E.Merk, Germany; Alcohol, chlorhydric acid, acetone and methyl aldehyde were purchased from Beijing Chemical Agent Company, PRC; 0.25% parenzyme was bought from Shanghai Xinhua Pharmaceutical Factory, PRC.Above-mentioned reagents were analytical pure grade.METHODS: After digestion, human limbal tissues in limbal basilar part with an abundant pigment were cultured in the culture flask containing RPMI-1640 and 200 g/L FCS and in culture dish containing amniotic extracellular matrix (AECM) as the cultural supporter. Primary and passage cells were observed under light microscope and scanning electron microscope (SEM). The revival ratio of stem cell refrigeration of every generation was calculated by the trypanblau exclusion experiment.MAIN OUTCOME MEASURES: ① Observational results of limbal stem cells during the primary culture and serial subcultivation in vitro, and ② revival ratio of stem cell refrigeration.RESULTS: ①Findings of primary culture: Most limbal stem cells in the culture flask had the adherence and were arrayed uniformly sparsely to form monolayer and adhered to the bottom of culture flask under the inverted phase contrast microscope after 1-day culture. ② Findings of serial subcultivation: After human epidermal growth factor (hEGF) was added into the second passage, cells were scattered into the monolayer and adhered to grow quickly.Morphological variability of all the cells increased obviously when passage the 30th generation. The cellular volume was obviously increasing, and the round or irregular round cells gathered together. The 33rd generation human limbal stem cells still could vigorously differentiate, proliferate and grow in ACEM. ③ The revival ratio of stem cell refrigeration was 82.2%.CONCLUSION: The human limbal stem cell lines were preliminarily established by culturing and freezing the cells of 33 generations in vitro. The human limbal stem cell lines preferred to grow in the culture dish containing AECM as the cultural supporter.

ObjectiveTo explore the treatment options for fresh Grauer type Ⅱ odontoid fractures and discuss corresponding clinical outcome.Methods The study involved 40 patients with fresh odontoid fractures including seven with type Ⅱ A fractures, 18 with type Ⅱ B and 15 with type ⅡC according to Grauer classification.There were five patients with incomplete cervical cord injuries.Type Ⅱ A fractures were treated by traction of occipital-jaw band or skull for 1-2 weeks and then fixed with head-neck-chest plaster or brace.Type Ⅱ B fractures were treated with anterior odontoid screw system fixation.Fifteen patients with type Ⅱ C fractures and three patients with type Ⅱ B fractures combined with severe fracture displacement were managed with posterior atlantoaxial pedicle screw fixation.Results All the patients were followed up for 6-24 months.Seven patients with type Ⅱ A fractures showed union after fixation with head-neck-chest plaster or brace for 3-6 months.Fifteen patients treated with odontoid screw fixation had good positions of screws, with no injury to the spinal cord, of which 14 patients obtained bone union, with union rate of 93.3％.Eighteen patients (including 15 patients with type Ⅱ C fractures and three with type Ⅱ B fractures combined with severe displacement) managed with atlantoaxial pedicle screw system showed no injury to the vertebral artery and spinal cord.Solid bone fusion was achieved.in 31 patients after 3 to 6 months.The X-ray and SCT scans verified proper fixation of the screws, with no deformation, loosening or breakage of the screws.Five patients with incomplete cervical cord injuries obtained neural function recovery at various degrees after surgery.ConclusionsConservative treatment cau be alternative to type ⅡA fractures.Anterior odontoid hollow screw fixation is better for type ⅡB fractures (non-displaced or reducible) and has advantages of minor trauma, fast postoperative recovery and high union rate.However, posterior atlantoaxial pedicle screw system fixation and fusion is suitable to type Ⅱ C and ⅡB fractures with severe displacement and has the advantages of stable three-dimension fixation, direct screw placement, intraoperative reduction, short-segment fixation and high fusion rate.

Objective To investigate the correlation between the expression of adhesion molecule CD146 and the vulnerability of carotid atherosclerotic plaque.Methods The plaque samples were collected from 40 patients who underwent the carotid endarterectomy and were divided into the stable plaque group and the instable plaque group by ultrasound imaging.Five carotid artery samples were taken from the healthy donors as the control.Immunohistochemistry was applied to test the CD146 expression in all samples.Results Higher expression of CD146 was observed in the atherosclerotic plaques than in the healthy control.Moreover,statistical difference was found in the expression of CD146 in the plaques between the instable plaque group and the stable plaque group (0.31 ± 0.19 vs 0.17 ± 0.07,P ＜ 0.05).The expression of CD146 was positively correlated with the necrotic area (r =0.471 8,P =0.019 9) and the matrix metalloproteinase (MMP)-9 expression in the plaques (r =0.535 6,P =0.000 9).Conclusion The CD146 expression is correlated with the vulnerability of carotid atherosclerotic plaque.

Objective To evaluate the effects of unilastatin on brain injury in children undergoing aortic arch surgery under cardiopulmonary bypass (CPB).Methods Twenty ASA physical status Ⅲ or Ⅳ children of both sexes,aged 1-24 months,weighing 3-12 kg,undergoing repair of coarctation of aorta or interrupted aortic arch complicated with intracardiac malformations under CPB,were randomly divided into 2 groups (n =10 each):control group (group C) and ulinastatin group (group U).Ulinastatin 20 000 U/kg was diluted into 10 000 U/ml with normal saline and it was then injected intravenously in 3 parts (1/3 was injected via the internal jugular vein after induction of anesthesia; 1/3 at the beginning of CPB and 1/3 at 5 min before aortic unclamping).In group C the equal volume of normal saline was given instead of ulinastatin.Blood samples were taken from the radial artery after induction of anesthesia (T1),at 10 min after aortic clamping (T2),at 10 min after aortic unclamping (T3),at the end of CPB (T4),and at 6 and 24 h after termination of CPB (T5,T6) for determination of plasma S100B protein and neuron-specific enolase (NSE) concentrations.Results There was no significant difference in plasma levels of S100B protein and NSE at T1 between the two groups (P ＞ 0.05).Plasma S100B protein and NSE levels were significantly increased at T2-5 as compared to the baseline values at T1 in both groups (P ＜ 0.05).Plasma S100B protein and NSE levels were significantly lower at T2-5 in group U than in group C (P ＜ 0.05).Conclusion Ulinastatin can attenuate brain injury in children undergoing aortic arch surgery under CPB.

Objective To investigate the effect of formative assessment on skill acquisition of basic life support (BLS) among medical students. Methods Totally 206 undergraduates were ran-domized into control group (C group) and interventional group (F group). A BLS lecture was given in both groups. And then, 45 min BLS training and BLS skill assessment (after training) were given in C group. Undergraduates in F group received BLS skill assessment (formative assessment) before training, and 15 min feedback was delivered based on the assessment, then 30 min BLS training was conducted. Skills assessment was conducted again in F group after the training. Student's-t-test was used to compare the difference of skills between the two groups and P<0.05 signifies statistically sig-nificant differences. Results Score of F group (85.2±7.3) were higher than that in C group (68.2± 13.2), with statistical difference. Conclusion A formative assessment could significantly improve skill acquisition of BLS among medical students.