Objective To observe the student's endocrine metabolism in senior high school during different periods.Methods 328 senior middle school students in different periods were investigated and the blood concentration of adrenaline(N),norepinephrine(NE),cortisol(CS),interleukin-2(IL-2),interleukin-6(IL-6)were measured by radioimmunoassay and Magnetic Solid Phase Separation-Enzyme Immunoassay,and at the same time,students in vocational high school were contrasted.Results As the university entrance examination was coming,the values of N,NE and CS were apparently rising,while the values of IL-2 and IL-6 were going down.The biodifferences.Grade Two and Grade One(t=1.96～2.52,P＜0.05).Grade Two and the control(t=3.53～4.20,P＜0.01)were different significantly,while Grade one and the control had no obvsious difference(t=1.18～1.92,P＞0.05).Conclusion N,NE,CS of the senior hish school students in Grade Three were higher,while IL-2and IL-6 were lower than that of the Grade Two.

Objective To clarify the morphological features,types,regional distributions and cell densities of gastrointestinal endocrine cells in various parts of the digestive tracts of Canis lupus and Canis familiaris. Methods Immunohistochemical techniques of streptavidin-peroxidase(SP) method was used. Results Seven kinds of gastrointestinal endocrine cells were found positive in the digestive tracts of Canis lupus and Canis familiaris.The endocrine cells were mainly located between the epithelia cells of gastric gland,intestinal villus and intestinal gland.There were also some endocrine cells distributed in the lamina propria and submucosa.The endocrine cells found in the digestive tract were in various shapes.Most of the endocrine cells had long cell processes run ning out to the lumen or the nearby cells.Among these endocrine cells,5-hydroxytryptamine(5-HT) positive cells had a widest distribution,followed by vasointestinal poplypetide(VIP) positive cells.The distributions of other cells were limited.From the comparison of the characters of endocrine cells of Canis lupus and Canis familiaris,most of the endocrine cells had similar morphological features and regional distributions except pancreatic polypeptide(PP) positive cells and substance P(SP) positive cells.There were differences in cell densities of some endocrine cells.Conclusion The results of Canis lupus and Canis familiaris reflect the similarity of mammals in the characteristics of the morphological features,types,regional distributions and cell densities of gastrointestinal endocrine cells,as well as the similarity in digestive physiology of canine animals.At the same time,the results of Canis lupus also exhibit characteristics of gastrointestinal endocrine cells of wild animals.

BACKGROUND:Fluorouracil is a basic chemotherapy drug for gastric cancer, and its drug resistance is commonly seen in clinic. Cancer stem cels have low sensitivity to chemotherapy drugs, which may be an important cause of tumor recurrence and progression folowing chemotherpay. OBJECTIVE: To explore the sensitivity of gastric cancer stem cels to 5-fluorouracil and related biology mechanism underlying multidrug resistance. METHODS: Stem cel marker CD44 and multidrug resistance protein thymidylate synthase in 69 cases of gastric cancer tissues were tested by immunohistochemical staining. The selection strategy was based on the clonal morphology, and gastric cancer stem cels were isolated from human gastric cancer cel line AGS to detect the expression of CD44 and thymidylate synthase and the self renewing ability. Inhibitory concentration 50 (IC50) of 5-fluorouracil in different AGS cel clone was detected using cel counting kit-8. RESULTS AND CONCLUSION:In 69 cases of gastric cancer tissues, the positive expression rates of thymidylate synthase and CD44 were 57% (39/69) and 61% (42/69), respectively, and there was a positive correlation between the expression of CD44 and thymidylate synthase (Kappa=0.41,χ2=11.59,P < 0.05). Cloning efficiency of the AGS cel line was 39% (29/69), wherein, vice cloning, secondary cloning, and ful clone proportions were 17% (5/29), 69% (20/29), 14% (4/29), respectively. After sub-cloning, the clone was digested using trysin folowed by low-density passage; vice clones were unable to passage, secondary clones could only passage a few, and ful clones could serialy passage. After treatment with different concentrations of 5-fluorouracil, the ful clone growth inhibition rate was significantly lower than that of secondary clones and AGS cels (P < 0.05). These findings show that gastric cancer stem cels are less sensitive to 5-fluorouracil, indicating the cels have a resistance to chemotherapy drugs, which may be one of the chemotherapy resistance mechanisms in the clinical treatment of gastric cancer.

Aim To investigate the protective effect of naringenin on isoniazid and rifampicin induced hepatotoxicity and the role of CYP 3A4.Methods Isoniazid and rifampicin were added to culture media for QSG-7701 cells and cultured for 48 hours. Narringenin, 1,5 and 25 mg·L~(-1) in final concentration,was added concomitant with isoniazid and rifampicin. The culture media and cells were collected and the activities of lactate dehydrogenase were detected with chromatometry. The ratio of extra/intracellular lactate dehydrogenase was calculated as the release rate of lactate dehydrogenase. Cells were incubated with midazolam for 2 hours after treatment with durgs and the concentration of midazolam in the incubation media was determined with HPLC-MS.Results Compared with control group, isoniazid and rifampicin treatment increased lactate dehydrogenase release and CYP 3A4 activity significantly. Naringenin attenuated the effect of isoniazid and rifampicin on lactate dehydrogenase and CYP 3A4 activity.Conclusion Naringenin can attenuate the hepatotoxicity of isoniazid and rifampicin through inhibiting the activity of CYP 3A4 in cultured hepatocytes.

Objective Dexmedetomidine is known to have a neuroprotective effect.The aim of this study was to investigate the effects of dexmedetomidine on ketamine-induced apoptosis of primarily cultured cortical neurons and its action mechanisms. Methods Rat cortical neurons were primarily cultured for 7 days and treated with ketamine (100μmol/L) and different concentrations of dexmedetomi-dine (0.001, 0.01, 0.1, and 1 μmol/L) for 24 hours, followed by measurement of the viability of the neurons by MTT assay.The neurons were divided into four groups:vehicle control, ketamine ( trea-ted with 100 μmol/L ketamine), dexmedetomidine+ketamine (DD+K, treated with 0.1 μmol/L DD and 100 μmol/L ketamine), and LY294002 ( treated with 0.1 μmol/L DD, 100 μmol/L ketamine, and 10 μmol/L LY294002) .After 24 hours of treatment, the apoptosis rate of the neurons was determined by Hoechst33258 staining, and the expressions of pAkt and cleaved-caspase-3 in the neu-rons detected by Western blot. Results The apoptosis rate of neurons was dramatically increased in the LY294002 and ketamine groups in comparison with the vehicle control and DD+K groups ([36.8 ±4.4] and [43.4 ±4.5]%vs [7.5 ±1.1] and [16.4 ± 3.6]%, P<0.01), the pAkt level remarkably decreased (0.26 ±0.02 and 0.15 ±0.01 vs 0.61 ±0.05 and 0.50 ±0.04, P<0.01), and the expression of cleaved caspase-3 significantly upregulated in the former two as compared with the latter two groups (0.40 ±0.02 and 0.65 ±0.03 vs 0.10 ±0.02 and 0.12 ±0.01, P<0.01). Conclusion Dexmedetomidine exerts a neuroprotec-tive effect against ketamine-induced apoptosis of neurons by activating the PI3K-Akt signaling pathway.

Objectives:This study was designed to observe the effect of S adenosyl L methionine (SAMet) on total parenteral nutrition (TPN) induced cholestasis in infected rats and to analyse the change of the bile acids in the bile. Methods:18 Sprague Dawley rats were divided randomly into 3 groups,control group,infection plus TPN group,and infection plus TPN and SAMet group.Each contained 6 rats.Caecum was ligated to induce intra abdominal infection.Nutritional support was maintained for 5 days.Bile was collected by cannulating catheter.The bile flow was determined.The blood samples were gathered to measure the levels of serum total bile acid(STBA),gammaglutamyltranspeptidase (GGT),alanine aminotransferase (ALT)and alkaline phosphatase (AKP).The pathological change in the liver was observed under light microscope and electron microscope.The billiary bile acid contents were determined by high performance liquid chromatographic (HPLC) method. Results:The infection plus TPN group showed that the bile flow was reduced,levels of STBA,GGT and AKP were elevated,and fat infiltration,bile capillary dilatation and bile embolism were obvious in the liver.However,the infection plus TPN and SAMet group showed that the bile flow was increased,levels of STBA,GGT,ALT and AKP were decreased,and the liver was kept normal. Conclusions:The use of SAMet is helpful to could prevent TPN induced cholestasis in infected rats.

Objective To establish a reliable approach for quantification of colony forming unit(CFU)of Mycobac-terium tuberculosis (M.tb)by measuring optical density(OD).Methods M.tb suspension H37Ra was prepared using low-power ultrasonic or glass bead beating methods,and was two-fold serially diluted,OD at 600nm (OD600)of each dilution ratio was measured respectively,OD600 and dilution curve were analyzed to determine the optimum approach for preparing bacterial suspension,linear range of OD600,as well as linear relationship between OD600 and CFU.Results OD600 was 0.1 -0.6,linear regression analysis of OD600 and dilution ratio within linear range revealed that correlation coefficient (R2 )of glass bead beating and low-power ultrasonic methods were 0.98 and 1 .00 respectively,both presented a good correlation,low-power ultrasonic method was better than glass bead beat-ing method,bacterial suspension dispersed more evenly.Linear regression analysis results of OD600 and CFU val-ues showed that the regression equation of glass bead beating method and low-power ultrasonic method were CFU=2.35×107 ×OD600+4.42×105 and CFU=3.26×107 ×OD600+6.89×105 respectively.Conclusion Low-power ultrasonic method is a good method for preparation of M.tb suspension,combined the measurement of OD600 value, it can be a reliable and rapid method for quantitative analysis of M.tb.

Objective To evaluate the efficacy of neuronavigation-guided selective percutaneous radiofrequency aiming at the target point semilunar ganglion in the treatment of trigeminal neuralgia.Methods One hundred and forty-seven patients with primary trigeminal neuralgia of both sexes,aged 32-99 yr,with VAS score ≥ 8,were randomly divided into 2 groups:C-arm group (group C,n =72) and neuronavigation group (group N,n =72).Hartel anterior puncture was used and the C-arm guided puncture was performed at the target point foramen ovale in group C.In group N,three-dimensional reconstruction was made after the skull MRI images were transmired to the navigational system of StealthStation,and then the puncture path and point were designed after the target in the trigeminal ganglion was determined.The successful puncture and puncture-and radiofrequency-related complications were also recorded.The VAS scores were recorded at 1 and 7 days and 1,6,12 and 24 months after operation and the analgesic efficacy was evaluated.The therapeutic effect was evaluated by using Barrow Neurological Institute scoring system at 1 and 24 months after operation.Results No puncture-related side effects,damage to the oculomotor nerve or tinnitus developed in group N.The success rate of puncture at first attempt and the effective analgesia rate at different time points after operation were significantly higher,and the treatment effect was better in group N than in group C (P ＜ 0.05).There was no significant difference in the time for location of the nerve and incidence of facial numbness between the two groups (P ＞ 0.05).Conclusion Neuronavigation-guided selective percutaneous radiofrequency aiming at the target point semilunar ganglion in the treatment of trigeminal neuralgia provides a better efficacy,and a lower recurrence rate and a higher probability of successful puncture,with fewer complications.

Objective:To assess the role of EGFR mutations on pemetrexed response in patients with advanced lung adenocarcino-ma. Method: Forty pulmonary adenocarcinoma patients with evaluable lesions were retrospectively screened .They had been treated with pemetrexed-included chemotherapy and had EGFR gene test results. The evaluation endpoints were overall response rate,disease control rate and progression free survival. Result:No significant statistical difference was seen in overall response rate(ORR) (44.4%VS 31.8%, respectively) and disease control rate(DCR) (88.9%VS 81.8%, respectively ) between EGFR wild group and EGFR muta-tion group, but patients in EGFR wild group had longer progression free survival(PFS) ( 8.9 months VS 5.3 months;P=0.046). Conclu-sion:EGFR mutation status can influence the efficacy of pemetrexed.

Gas chromatography with mass spectrum detector ( GC-MSD) coupled with purge-and-trap system was set up to analyze the concentration of isoprene in natural waters. The best experimental conditions were established, including purge gas flow rate ( 50 mL/min ) , purge time ( 15 min ) , the optimum capillary column ( Rt-Alumina BOND/KCl) and the appropriate condition of temperature programming. When analyzing isoprene in natural waters, the precision was <4% (n=6), the detection limit was 0. 5 pmol/L and the recovery was 91%-102%. The preservative experiment showed that there was no obvious variation in sample concentrations of isoprene within 60 days. The concentrations of isoprene measured with the method ranged from 60 . 8 to 278 . 7 pmol/L in the Jiaozhou Bay and its adjacent river estuaries and from 44 . 7 to 77 . 2 pmol/L in Yellow River estuary, which was in good accord with those results reported in literatures in other coastal waters. In conclusion, the analytical method could meet the requirements of the analysis of concentration of isoprene in natural waters.