The number of clinical postgraduates is growing with the reform of educational mode of postgraduates.It is a particular concern for medical colleges to improve educational quality of postgraduates,especially to cultivate postgraduates with great ability of observational study.The ability of clinical thinking and observational study is a key objective throughout postgraduate teaching.A good teaching method plays an important role in improving the ability of observational study for clinical postgraduates.A teaching platform combining academic theories with clincal pratice is a basis for promoting quality of clinical postgraduates.The construction of tutor team is a key point in elevating clinical observational ability.Academic exchange is a shortcut to cultivate postgraduates with great observational ability in clinical work.

Objective To investigate the distribution of ompA gnne in 15 Chinese reference standard strains belonging to 15 serogroups of Leptospira interrogate, and to express recombinant OmpA ( rOmpA ) and to identify immunogenicity and immunoprotection of rOmpA. Methods Genomic DNAs from different leptospiral strains were extracted by phenol-chloroform method. Entire ompA gene fragments from the strains were amplified by PCR and then sequenced after T-A cloning. A prokaryotic expression system of ompA gene from L. interrogans strain 56601 was constructed, and the expression and yield of rOmpA were determined by SOS-PAGE plus Bio-Rad Agarose Image Analyser. Rabbits were immunized with rOmpA for obtaining antiserum, and immunodiffusion test was used to measure the antiserum's titer. Western blot assay was performed to determine the immunoreaetivity of rOmpA with the antiserum against rOmpA and antiserum against whole cell of L. interrogans strain 56601, while mi-croscopic agglutination test (MAT) was applied to detect the cross agglutination to the 15 L. interrogans strains. A leptospire adhering cell model and a leptospire infecting guinea pigs model were used to determine the adhesion-bloc-king effect of rOmpA antiserum and immunoprotection of rOmpA. Results All the 15 L. interrogans strains, but not L. biflexa strain Patoe Ⅰ , had sequence conserved ompA genes. The yield of rOmpA was approximate 20% of the total bacterial proteins, rOmpA could induce rabbits to produce antibody and immunodiffusion titer of the anti-serum was 1:4. Both antisera against rOmpA and against whole cell of L. interrogans strain 56601 were able to pro-duce positive Western blot signs to rOmpA, and the former offered 1 : 20-1 : 320 MAT titers to the 15 L. interrogans strains. 1: 10-1:160 dilutions of rOmpA antiserum could efficiently block L. interrogans strain 56601 adhering to J774A. 1 cells, and 100 μg and 200 μg rOmpA displayed 50.0% and 75.0% immunoprotective rates in the infee-ted guinea pigs. Conclusion ompA gene only exists in genomes of different pathogenic L. interrogans serogroups. rOmpA has relatively stronger antigenicity, cross immunoreactivity and certain immunoprotection, implying that this recombinant protein may be used as a candidate antigen for developing universal genetic engineering vaccine of L. interrogans.

Objective To explore a new high-throughput method with internal standards for analyzing the methylation profiles of lung cancer related genes. Methods The promoter sequences of 7 lung cancer related genes were cloned into plasmids and the target segments were amplified by their special primers respectively. The products were treated with M. Sss Ⅰ methylase and bisulfite. The multiplex ligation PCR method was established by designing probes containing CpGpCpG(for methylatedsequence) at the 3' ends and choosing the optimal ligation enzyme, annealing and ligation temperatures. The standard calibrators and clinic samples were tested by fluid chip platform. The results were validated by methylationspecific PCR. Results We successfully set up the standard calibrators for methylation and unmethylaiton of 7 lung cancer related genes and established a multiplex ligation PCR combined with fluid chip method, which was used to detect methylation status of 7 genes simultaneously. The fluorescence value of p16INK4A, APC,DAPK, RARIβ, RASSF1 A, MGMT and GSTP1 methylation standard calibrators were 863,909,703,701,901,1 060 and 885, much higher than that of unmethylation standard calibrators. The results were consistent with the results of methylation-specific PCP. ConclusionThe new high-throughput method can be used to evaluate the methylation status of 7 lung cancer related genes simultaneously and might be useful for clinical practice.

BACKGROUND: It has been suggested that amniotic epithelial cells (AECs) express almost all the markers of neural cell and secrete biologically active neurotrophins such as brain derived neurotrophin factor (BDNF) and neurotrophin-3 (NT3).If AECs can substitute neural cells, its neurotrophic effect will bring expansive prospect in treating spinal cord injuries and degenerative neural disease.OBJECTIVE: To observe the survival, migration and secretory function of AECs after transplanted into the injured spinal cord.DESIGN: An observational experiment.SETTING: Department of Histology and Embryology, School of Basic Medical Science, Jilin University.MATERIALS: Embryonic rat of 12-14 days (n =1) and adult Wistar rats (n =18, 300-350 g) were provided by the Experimental Animal Center of Jilin University. Immunohistochemical reagents: Mouse anti-rat BrdU monoclonal antibody was bought from Sigma Company. Rabbit anti-rat NT3 polyclonal antibody and rabbit anti-rat BDNF polyclonal antibody were bought from Boster Company. SP immunohistochemistry reagents were purchased from Maixin Company.METHODS: The experiment was made in the Department of Histology and Embryology, Basic Medical Science of Jilin University from July to October 2005. ① Wistar rats were anesthetized by intraperitoneal injection of chloral hydrate, subcutaneous tissue and muscle were separated, spinous process and lamina of vertebra were removed by bone ribbing rongeur. to expose the spinal cord. The spinal cords were clamped at the twelfth thoracic vertebra (T12) for 3 minutes.After surgery, the wounds were smeared with penicillin G, then muscle and skin were sutured. The rats were anesthetized by inhaling ether if necessary. ② Obtaining and culture of AECs: Amniotic membrane was peeled from the placenta of a pregnant Wistar rat of 12-14 days. The amnictic membrane was dissected into small pieces of 1 mm×1 mm×1 mm, then digested and cultured, and mechanically made into single cell suspension, finally plated in bottles. ③ Transplantation of AECs into injured spinal cord: The initial wound was slit and injected with 5 μL Brdu labeled AECs (1×1012 L-1) to the exposed injured spinal cord at 3.0 mm anterior to the injured site. The injections were made at a rate of 5 μL per 3 minutes with a microsyringe. The syringe was slowly pulled out after 5 minutes, then muscle and skin were sutured. ④ Sampling and immunohistochemical analysis: Three animals were sacrificed at 1 week and the other three at 2 weeks postoperatively. The sections were fixed with 40 g/L paraformaldehyde in phosphate buffer solution (PBS) for 20 minutes at room temperature, followed by incubation with primary antibodies at 4 ℃ overnight. The samples were treated with secondary antibodies, biotinylated anti-mouse or rabbit immunoglobulin (IgG) at 37 ℃ for 20 minutes; Followed by incubation of horseradish peroxidase (HRP) labeled third antibodies at 37 ℃ for 20 minutes, then stained with 0.2 g/L diaminobenzidine (DAB) or AEC.MAIN OUTCOME MEASURES: Survival, migration and expression of AECs after transplanted into the injured spinal cord. RESULTS: After transplantation, most of the AECs gather beneath the pia mater of injured spinal cord at 1 week. But they migrated more extensively and many positive nuclear cells (brown) were observed in the center cannel and surrounding gray mater. Meantime, it was also detected that the transplanted AECs could express NT3 (positive cells stained as red) and BDNF in the injured spinal cord.CONCLUSION: AECs could survive for at least 3W after transplanted into the injured spinal cord of adult rats and could migrate widely; Furthermore, they could secrete neurotrophic factors such as NT-3 and BDNF.

Cre/LoxP system has been widely used as new type of gene targeting, which can transform genes in specific tissues and organs, remove specific gene fragments, and help to study the effects of specific genes on growth and development.Cre/LoxP system is the core technology of conditional gene targeting, which induces gene targeting, and spatiotemporal specific gene targeting.The resource about the mechanism of the Cre/LoxP system is helpful to obtain the Cre transgenic mouse model on different cell types of the retina.The Cre transgenic mice with specific expression in retinal bipolar cells and ganglion cells can provide the experimental basis for the absence of specific tissue single genes during growth and development.This review focused on the Cre/LoxP system and specific Cre recombinase mouse model in eyes.

Objective A new method for detecting K-ras mutations based liquid chip was used to evaluate K-ras mutations associated with non-small cell lung cancer (NSCLC) patients,to direct the personalized treatment and prognosis evaluation.Methods Take the diagnosis technology research methods,the sensitivity and repeatability of the liquid chip K-ras gene mutation detection method were assessed.A total of 100 NSCLC patients from Nov 2011 to Feb 2012 in Shanghai Chest hospital were included in this study,the fresh tumor tissues were collected for DNA extraction.The 2nd exon 12 and 13 codons,containing 8 K-ras mutations occuring in high frequency were amplified by polymerase chain reaction (PCR),followed by ligation of the PCR products to a series of special probes using ligase detection reaction (LDR),then the PCR-LDR products were analyzed by liquid chip platform.Direct sequencing was applied to compare with the detection results.Results The sensitivity of liquid chip technology detection was 10％-20％,higher than the traditional sequencing method by 1％.Average CV value was 4％-15％ and showed good repeatability.5 K-ras mutations in 100 patients (5％) were detected using multiplex PCR-LDR combined fluid chip methods,including 3 Glyl2Val and 2 Gly12Asp mutations in exon 2.The 5 K-ras mutations were verified accurately by direct sequencing.Conclusions The novel detection method of K-ras mutations based PCRLDR and fluid chip shows high throughput,high sensitivity,good repeatability and the results are reliable and accurate.This method can be used to accurately identified K-ras mutations for NSCLC patients prior to their targeted therapy with TKIs.

AlM: To investigate the effect of endocapsular phacoemulsification cataract extraction and intraocular lens (lOL) implantation with a 1. 8mm or 3. 0mm clear corneal incision on total root mean square ( RMS ) value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film.
METHODS:ln a prospective study, 156 age- related patients ( 196 eyes ) were randomly distributed into two groups. 1. 8mm-group comprised 94 eyes that had a silicone lOL inserted through a 1. 8mm sutureless clear corneal incision, while, 3. 0mm- group comprised 102 eyes through a 3. 0mm clear corneal incision. Postoperatively, the changes in the total RMS value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film at 1wk, 1 and 3mo were determined respectively.
RESULTS:ln both groups, postoperatively at 1wk,there were statistically significant differences ( P<0. 05 ) in the total RMS value of the cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film, while, there were statistically minimal differences ( P< 0. 05 ) between 1. 8mm-group and 3. 0mm-group at 1mo, but were not statistically significantly different ( P > 0. 05 ) between two groups at 3mo postoperative.
CONCLUSlON:This study confirms that incision size has strong impact on the corneal higher-order aberrations, especially, 3. 0mm incision caused significant differences in the total RMS value of cornea, corneal astigmatism, spherical aberration, coma, trefoil and tear film compared with 1. 8mm micro-incision, therefore, micro-incision is very beneficial for clinical use in phacoemulsification.

Sepsis and septic shock have high morbidity and mortality. The key point is that huge amount of nitric oxide (NO) is releasing into circulation, inducing marked dilation of blood vessels, and continuously decreased of blood pressure. The central link is inflammation and oxidative stress. Methylene blue can effectively inhibit NO, remove excessive NO and block the signal transduction pathway named inducible nitric oxide synthase-NO-soluble guanylate cyclase-cyclic guanosine monophosphate (iNOS-NO-sGC-cGMP). Meanwhile, it also play a role in inhibiting oxidative stress and inflammation. This paper reviews the mechanism of methylene blue in the treatment of sepsis and septic shock, as well as its treatment time window, optimal dose, administration mode and potential adverse reactions, to provide new ideas for clinical treatment.

Objective To observe the effect and safety of metformin com-bined with saxagliptin or glimepiride in patients with type 2 diabetes me-llitus inadequately controlled with metformin alone .Methods Sixty pa-tients with type 2 diabetes mellitus inadequately controled by metformin alone were randomly divided into trial group and control group , 30 pa-tients in each group .The two groups maintain the original dose of met-formin and usage unchanged , patients in trial group were given oral saxa-gliptin 5 mg, once a day , and the patients in control group were treated with glimepiride 1-4 mg once daily before breakfast .The treatment las-ted 12 weeks.The data of fasting plasma glucose ( FPG) , 2 h postpran-dial plasma glucose(2 h PG), hemoglobin A1c(HbA1c), lipids weight, fasting insulin ( FINS) , homeostasis model assessment of β-cell function ( HOMA -β) were recorded and compared between the two groups . Results The serum levels of FPG , 2 h PG and HbA1 c were significantly decreased in two groups after treatment ( P<0.05 ) , but had no signifi-cant differences between the two groups .Compared with control group , the levels of FINS and HOMA-βstatistically increased after treatment in the trial group ( P <0.05 ) .There was no serious adverse reaction in both groups during the treatment , the incidence of mild hypoglycemia was significantly less in trial group ( P<0.05 ) . Conclusion The blood glucose control of saxagliptin is comparable to glimepiride , but saxagliptin showed a better effect on the improvement of β-cell function and decrease of the risk of hypoglycaemia .

OBJECTIVETo observe the expression of Clara cell secretory protein(CCSP) in the Kunming mouse model of n-hexane long-term inhalation, and to discuss the functions of Clara cell in injury lung induced by n-hexane.

METHODS24 healthy mice were randomly divided into 4 groups: one control group and three n-hexane groups (4 w, 8 w and 12 w), 6 each group. Primary concentration of n-hexane was 17.6 g/m3, 8 hours per day, 6 d per week. After inhalation, n-hexane concentration of blood from celiac artery was detected. The lungs were embedded with paraffin and HE staining in the routine. The ratio of Clara cells with CCSP reaction in bronchiole and the number of macrophage cells with lysozyme reaction were determined by immuno-histochemistry.

RESULTSIn the poisoning groups, the average n-hexane concentration of blood was significantly higher than that of the control group (P < 0.01). There were apparent pathologic damages in lungs of the poisoning mice. In poisoning 4 w, 8 w and 12 w groups, the ratio of Clara cells was significantly decreased [(73.33 +/- 4.21)%, (60.98 +/- 4.94)%, (34.04 +/- 2.33)% in terminal bronchiole, and (75.44 +/- 7.91)%, (58.54 +/- 4.86)%, (33.35 +/- 2.67)% in respiratory bronchiole] as compared with the control mice [(80.26 +/- 6.43)% and (81.74 +/- 7.75)%, P < 0.05 or P < 0.01], meanwhile the numbers of macrophage cells were gradually increased [(21.39 +/- 7.41), (28.54 +/- 10.73), (48.97 +/- 19.55) per microscopic field at 200x] in poisoning mice than those in control mice [(7.84 +/- 3.12) per microscopic field at 200x, P < 0.05 or P < 0.01].

CONCLUSIONIn injury lungs after n-hexane inhalation, Clara cells are the target cells of n-hexane toxicity effect. Clara cells play an extensive protective role in lung inflammation.

Animals ; Epithelial Cells ; metabolism ; Hexanes ; toxicity ; Inhalation Exposure ; Lung Injury ; etiology ; metabolism ; Mice ; Mice, Inbred Strains ; Toxicity Tests, Chronic ; Uteroglobin ; metabolism