0.999 5), RSD were no more than 3.0%. The recovery rates were 98.0%-102.0%. There was no significant difference between the results of this method and EDTA-Na2 titration. Conclusion The method is rapid, accurate, simple, little disturbance and is acceptable in determination of total hardness in drinking water.

Objective To investigate the effects of dexmedetomidine (Dex) on the neuronal apoptosis in spinal dorsal horn in a rat model of chronic neuropathic pain.Methods Seventy-two adult male SD rats weighing 180-220 g were randomly divided into 3 groups ( n =24 each):sham operation group (group S) ; chronic constrictive injury (CCI) group; Dex + CCI group (group D).Two ligatures were placed on right sciatic nerve at 1 mm intervals with 4-0 silk thread in groups CCI and D.In group D Dex 50 μg/kg was injected intraperitoneally once a day starting from the end of operation until the animals were sacrificed.Paw withdrawal threshold to mechanical stimulation with yon Frey filament (PWT) and paw withdrawal latency to thermal stimulation (PWL) were measured at one day before (T0,baseline) and on the 3rd,7th and 14th day after operation (T1,2,3).Six animals were sacrificed at each time points (T1,2,3) after the measurement of PWT and PWL.Their lumbar segments (L4,5)were removed for examination with transmission electron microscope and detection of Bcl-2 and caspase-3 expression (by immune-histochemistry).Results CCI significantly decreased PWT and PWL,increased Bcl-2 and caspase-3 expression at T1,2,3 and induced apoptosis in spinal dorsal horn neurons in group CCI as compared with group S.Intraperitoneal Dex significantly attenuated CCI-induced mechanical and thermal hyperalgesia and neuronal apoptosis in group D as compared with group CCI.Dex injected intraperitoneally further increased Bcl-2 expression but decreased caspase-3 expression in group D as compared with group CCI.Conclusion Reduction in neuronal apoptosis in spinal dorsal horn is involved in the attenuation of neuropathic pain by Dex.

Objective To investigate the effect of dexmedetomidine on the expression of purinergic P2X4 receptor (P2X4R) mRNA and p38 mitogen-activated protein kinase (p38 MAPK) mRNA in spinal cord in a rat model of neuropathic pain (NP).Methods Seventy-two male SD rats weighing 180-220 g were randomly assigned into 3 groups ( n =24 each):sham operation group (group S),group NP and dexmedetomidine group ( group DEX).The animals were anesthetized with intraperitoneal 10％ choral hydrate 350 mg/kg.NP was induced by chronic constrictive injury (CCI).The right sciatic nerve was exposed and 4 ligatures were placed on sciatic nerve at 1 mm intervals with 4-0 silk thread in groups NP and DEX.In group S,the right sciatic nerve was only exposed but not ligated.Dexmedetomidine 50μg/kg was injected intraperitoneally daily staring from the end of operation,while the equal volume of normal saline was injected in groups S and NT.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured on day 1 before operation and on day 1,3,7 and 14 after operation.Six animals were sacrificed after MWT and TWL measurement on day 1,3,7 and 14 after operation in each group,the L4～6 segment of spinal cords was removed for determination of P2X4 R mRNA and p38 MAPK mRNA expression by RT-PCR.Results Compared with group S,MWT and TWL were significantly decreased and the expression of P2X4 R mRNA and p38 MAPK mRNA was significantly up-regulated after operation in groups NP and DEX ( P ＜0.05).Compared with group NP,TWL and MWT were significantly increased and the expression of P2X4 R mRNA and p38 MAPK mRNA was significantly down-regulated after operation in group DEX ( P ＜ 0.05 ).TWL and MWT were significantly higher and the expression of P2X4 R mRNA and p38 MAPK mRNA was significantly lower on day 1,3 and 14 after operation than on day 7 after operation in groups NiP and DEX ( P ＜ 0.05).Conclusion The mechanism by which dexmedetomidine attenuates NP is related to inhibition of the expression of P2X4 R mRNA and p38 MAPK in rats.

Objective To investigate the functional polarization of T cells in children with obstructive sleep apnea hypopnea syndrome (OSAHS).Methods Forty five cases of OSAHS children were chosen to undergo tonsillectomy and adenoidectomy.Preoperative analyses of peripheral blood Th1 /Th2 ratio and Tc1 /Tc2 ratio were compared with those of normal children and those of postoperative 6 months for observation of the change of T cells.Th1/Th2 ratio and Tc1/Tc2 ratio were detected by flow cytometry.Results The preoperative ratio of Th1 cells in children with OSAHS was significantly lower than normal children [(9.66 ± 3.73) ％ vs (13.34 ± 4.36) ％,P ＜ 0.05],while the preoperative ratio of Th2 cells was significantly higher than normal children [(3.42 ± 1.64) ％ vs (2.53 ± 1.97) ％,P ＜ 0.05],which made the Thl/Th2 ratio lower than normal children (3.51 ± 1.53 vs 5.41 ±2.17,P ＜0.05).At the 6th month after tonsillectomy and adenoidectomy,the postoperative ratio of Th1 cells was significantly higher than preoperative ratio [(12.99 ± 3.68) ％ vs (9.66 ± 3.73) ％,P ＜ 0.05],while the postoperative ratio of Th2 cells was lower than preoperative ratio [(2.62 ± 1.88) ％ vs (3.42 ± 1.64) ％,P ＜ 0.05],which made the postoperative Th1 /Th2 ratio higher than preoperative ratio (5.15 ± 1.86 vs 3.51 ± 1.53,P ＜ 0.05).There was no significant difference in Tc1 /Tc2 ratio between the OSAHS children and normal children.Conclusions Functional polarization of T cells was abnormal in OSAHS children accompanied by the predomination of Th2 cells and the normal Tc cell polarization.Functional polarization of T cells can return to normal at the 6th month after tonsillectomy and adenoidectomy.

Objective To prepare totel glucosides in paeony(TGP) pellets by extrusion-spheronization and to optimize the formulation of TGP sustained-release pellets coated with Eudragit RS 100.Methods The TGP sustained-release pellets were prepared by mini Glatt fluidized bed coating method.The factors to influence the drug release behaviors and their properties were evaluated.Results The optimal TGP sustained-release pellet was shown significant sustained-releasing at the loading weight of copolymers of 6% and the plasticizer concentration of 10%.And the curves of cumulative drug release were fit for Peppas and Higuchi equation.Conclusion The pellets showed an obviously sustained-release effect.

Human papillomavirus continuous (HPV) infection is an essential factor to induce cervical intraepithelial neoplasia and cervical cancer.Treating HPV infection is considered as a starting point to develop an effective therapeutic vaccine, which is a new strategy for prevention and treatment of cervical cancer.In recent years, development and trials of therapeutic HPV vaccine have made great progress.Selection of vectors, utilization of adjuvants, synthesis of fusion proteins and chimeric proteins have been widely applied to research to enhance vaccine immunogenicity, to increase vaccination safety, to reduce the side effect and so on.The clinical trial results are encouraging: various types of vaccines can induce a specific immune response with good tolerance.However, numerous studies are still required to obtain further success.In addition, HPV exists in various forms, thus it is also the focus of study to expand the range of action and reduce immune escape.

Tianjin Medical University set up the module of Early Clinical Practice in the 2012 year's new curriculum system which takes the teaching mode of combining the in-class curriculum and the extracurricular scientific research as well as the social practice.The in-class curriculum refers to the early contact clinical curriculum,namely making the early contact clinical practice training as a compulsory course,which focuses on the cultivation of students' medical professional ethics and the cultivation of doctor-patient communication ability,health promotion and preventive medicine consciousness,to strengthen students' clinical thinking,clinical research ability and basic skills training.The extracurricular part mainly takes the innovation credit project as the instruction,which will make the social practice,scientific and technological innovation activity project,clinical basic skills training comprehensive,and train students' ability of organization plan,communication and coordination,word expression and scientific research ability.

Objective To find the spectacular indexes in the diagnosis of acute rejection of renal transplantation with color Doppler ultrasonography. Methods Forty-two patients with renal rejection were confirmed with percutaneous needle biopsy and 115 patients with stable renal function were confirmed with following-up (>1 year) and clinical examination. The length, width, thickness, cortex thickness and resistive index (RI) of two groups were analyzed statistically. Then the specificity, sensitivity, misdiagnosis rate, false negative rate and consistency rate of renal volume, pyramid swelling, echo weakening, RI＜0.7, RI≥0.7 and RI≥0.8 were calculated. Results The length, width and thickness were statistically different in two groups (P＜0.05). In patients with renal rejection, the marginal blood vessels in renal cortex decreased, and the blood velocity reduced obviously in the diastolic phase and RI increased obviously (P＜0.05). The sensitivity of the above indexes were 55.30%, 55.20%, 42.10%, 57.90%, 31.60%, respectively, while the specificity were 71.30%, 87.10%, 25.70%, 74.20% and 98.20%, respectively. Conclusion Enlargement of renal volume, swelling of renal pyramids, echo weakening and RI increasing are specific indexes for diagnosis of acute rejection of renal transplantation.

Lysostaphin is highly effective on eliminating methicillin resistant Staphylococcus aureus (MRSA). In order to achieve controlled release of lysostaphin, a biocompatible drug carrier is needed. Hydroxyapatite/chitosan (HA/CS) composites were chosen to carry lysostaphin and sample composites with different weight ratios of HA to CS, including 80/20, 70/30, 60/40, and 40/60, were prepared. Multiple analyses were performed to determine the structural and physicochemical properties of the composites, including scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We immersed HA/CS composites loaded with 1 wt% lysostaphin to test in vitro release activity and cultured MC3T3-E1 cells to carry out biocompatibility test. The result of the release behavior of the composites revealed that the controlled release of lysostaphin from 60/40 HA/CS composites was the highest release rate of (87.4 ± 2.8)%, which lasted for 120 hours. In biocompatibility testing, MC3T3-E1 cells were able to proliferate on the surface of these composites, and the extract liquid from the composites could increase the growth of the cells. These results demonstrate the controlled release of lysostaphin from HA/CS composites and their biocompatibility, suggesting the potential application of these composites to bone injury and infection applications.

BACKGROUND: Hydroxyapatite/chitosan (HA/CS) complex may act as a drug carrier for drug release, but little is reported about the release amount and antibacterial effect of minocycline-HA/CS (Mino-HA/CS) complex. OBJECTIVE: To investigate the in vitro release and antibacterial property of Mino-HA/CS complex. METHODS: HA/CS and Mino-HA/CS were prepared using co-precipitation method. The surface and cross-section features of the complexes were observed under scanning electron microscopy. The porosities were measured according to Archimedes Principle. The release of minocycline hydrochloride was measured by high performance liquid chromatography with the simulated saliva as drug release media. In vitro antibacterial effect on Porphyromonas gingivalis and Staphylococcus aureus were measured by bacteria-inhibiting ring method. Biological toxicities were evaluated via cel counting kit-8cel proliferation assay. RESULTS AND CONCLUSION: The porosity of Mino-HA/CS was larger than that of HA/CS, with the average porosity of 53.99%. Single-day release amount of Mino-HA/CS could maintain at the level of 0.5-1 μg per day for a long-term. Bacteriostatic rings of Porphyromonas gingivalis and Staphylococcus aureus stil existed clearly after 7 days. Cel proliferation assays showed that Mino-HA/CS extract had the significant effect on promoting cel proliferation. These findings indicate that the Mino-HA/CS sustains the release of minocycline at a relatively stable level within a longer period, shows good inhibitory effect on Porphyromonas gingivalis and Staphylococcus aureus and promotes the proliferation of periodontal ligament cel s.