Cancer stem cells located in specific microenvironment,that play an important role in the proliferation and metastasis of tumor cells.Hypoxia is one of the important features of tumor tissue microenvironment.A series of studies results show that the hypoxic microenvironment of tumor stem cells could promote tumor metastasis,which provides new clues for understanding tumor pathogenesis and tumors treatment.

Objective To summarize the experience of modified mini-cholecystectomy. Methods A total of 128 patients underwent mini-cholecystectomy by using a modified Bookwalter retractor, a self-made deep-site tying tool and an L-shape electrotome from September 1998 to June 2003. Results That the length of incision ≤ 6 cm was regarded as a surgical success. Out of the 128 patients, the surgical success was achieved in 110 patients (85 9%). Conclusions In mini-cholecystectomy, the use of the modified Bookwalter retractor greatly improves the visualization of operation field, and the use of the self-made tying tool facilitates deep-site manual knot tying.

Objective To establish loop-mediated isothermal amplification(LAMP)method for detecting Streptococcus pneumoniae in clinical samples.Methods Four Streptococcus pneumoniae-specific LAMP primers were designed according to the published sequence of strain R6(GenBank accession number AE008540).Genomie DNA in positive blood cultures was extracted by nanidine hydrochloride and benzene-methanol.Then lytA was amplified by LAMP at 63℃ for 45 minutes.We observed the turbidity in thereaction tube.For further confirmation.The amplified products were also detected using electrophoresis in 2% agarose gels,followed by ethidium bromide staining.Resuits 16 strains of Streptococcus pneumoniae were detected in 196 positive blood cuhure bottles by LAMP.Compared with traditional method.It8 sensitivity and specificity were both 100%and the detection could be finished in an hour.The assay had a minimum detection limit of 102 CFU/m1.Conclusions This IJAMP-based assay is simple,rapid.Sensitive and specific.It can be used to detect trept OCOCCUS pneumoniae in clinical samples.

Objective To investigate the skin basic conditions of normal female consumers for cosmetics who use a cream of lower than RMB 25 yuan in markets in Chengdu area.Methods Female subjects aged 25 to 45 years were recruited in Chengdu and divided into four age groups.Parameters were noninvasively tested to investigate skin baseline conditions of the two groups,including skin moisturization,trans-epidermal water loss (TEWL),color,texture and pH etc.Meanwhile,subjective scores were acquired by experienced dermatologists and self-questionnaires were collected to investigate subjects' concerns.Results Skin texture,softness,and skin color were found significantly different between age groups.The top 3 skin problems were dryness,skin color and wrinkles; the top 3 ideal skin were moisture,shining and fairness.Conclusions With similar environment and skin care habits,35-year-old is a turning point for females of decreased metabolism in the skin,as seen from skin color,elasticity,and roughness.

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 investigate the feasibility and accuracy of osmometer in the osmolarity measurement of pirenoxinun sodi-um eye drops. Methods:An osmometer was used to measure the osmolarity of pirenoxinun sodium eye drops, and the stability of the osmolality was studied. Results:The osmolarity of pirenoxinun sodium eye drops with different formula conformed to the requirement of ophthalmic preparations. The osmolality showed no significant change at the ambient temperature, indicating the stability of the prepa-ration. Conclusion:The method is simple, rapid and practical, which can be used as the osmolarity measurement method for pirenoxi-nun sodium eye drops.

Objective To investigate the protective effect and the mechanisms of 17β-estradiol on ketamine-induced apoptosis on primary cultured rat cortical neurons. Methods Cortical neurons were primarily cultured for seven days,then divided into four groups :control group ( treated with equal valume of DMSO ),estradiol-treated group ( treated with 0.1 μmol·L-1 17β-estradiol),ketamine-treated group(treated with 100 μmol·L-1 ketamine),ketamine plus 17β-estradiol-treated group( treated with 0. 1 μmol·L-1 17β-estradiol+100μmol·L-1 ketamine). The neurons were treated for 24 hours. The neuron viability was determined by MTT. Neuroapoptosis was measured by nuclear morphometry after Hoechest 33258 dying. Western blotting was performed to detect the expression levels of cleaved-caspase-3 and Bcl-2protein. Results The neuron viability in the ketamine group was(54. 02±7. 78)%,significantly decreased from the control group,whereas ketamine plus 17β-estradiol increased the cell viability to(88. 09±6. 54)%,significantly higher than the ketamine group. The neuroapoptosis rate in the ketamine group was(49. 50±4. 34)%,significantly increased from the control group,while that in the drug combination group was(15. 74 ± 3. 40)%,significantly lower compared with the ketamine group. Meanwhile,the cleaved-caspase-3 expression increased,and Bcl-2 expression decreased remarkably after ketamine treatment,while which was reversed in the drug combination group. Conclusion 17β-estradiol can protect against ketamine-induced injury by inhibiting neuron apoptosis.

AIM To investigate if morphine addiction and relapse to morphine-seeking is related to the change in neurosteroid levels in the brain of rats. METHODS Rats were injected ip morphine (5 mg·kg-1·d-1, 18:00-20:00) and trained in conditioned place preference (CPP) box, once daily for 10 d. CPP test was performed 24 h after the last training. After discontinuation of training for 7 d for CPP extinction, then intermittent and inescapable foot-shock (FS, 0.5 mA, 0.5 s on, 40 s off, 15 min) was applied to rats as the priming stimuli for relapse. CPP test was performed 2 h after FS. When CPP test finished, rats were decapitated and the levels of neurosteroids were analyzed using gas chromatography/mass spectrometry. RESULTS CPP was established when rats were injected morphine and trained for 10 d. At the same time, the levels of pregnenolone and allopregnanolone in the brain tissues of rats were significantly increased. When CPP was reinstated in morphine-treated rats by FS-stress after 7 d CPP extinction, the levels of dehydroepiandrosterone and dehydroepiandrosterone sulfate were significantly increased. CONCLUSIONThe development of morphine addiction and relapse may be related to endogenous neurosteroids in rat brain tissues.

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.

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.