Designed experiment can improve the students'study interest and train their scientific research ability in bioanalytical chemistry experiment teaching.This article probes into the devise of designed experiment,the selectivity of the contents and the detailed process of the experiments.

Objective To investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) pretreatment on lung agaillst LPS-indueed injury in rats.Methods Fifty-four Wistar rats of both sexes weighing 180-220 g were randomly idivided into 3 groups:group I normal control(group C,n=6);group Ⅱ LPS (group L,n=24)and group Ⅲ PDTC(group P,n=24).Endotoxemia was induced by intraperitoneal LPS 8 mg/kg in group Ⅱ and Ⅲ.In group Ⅲ PDTC 120 mg/kg was injected iv at 30 min before IP LPS.Venous blood samples were collected at 1,3,6 and 12 h after LPS administration in group L and P and after normal saline administration in group C for determination of serum IL-6 concentration by ELISA.Six animals were killed at each time point after blood sample collection.The lungs were removed for microscopic examination and determination of W/D lung weight ratio,HSP70 expression and NF-κB activity.Results Intraperitoneal LPS significantly increased serum IL-6 concentration and W/D lung weight ratio,HSP70 expression and NF-κB activity in group Ⅱ.PDTC pretreatment significantly attenuated LPS-induced increase in serum IL-6 concentration,W/D lung weight ratio andNF-κB activity.The lung histologic dalnage induced by LPS Wag also ameliorated by pretreatment with PDTC.Conclusion Pyrrolidine dithiocarbamate pretreatment Can protect lung against LPS-induced injury through inhibition of activation of lung tissue NF-κB and up-regulation of expression of HSP70.

Objective To investigate the change of endocrine, cAMP and potential mechanism in asthenia cold syndrome rats. Method The rats were randomly divided into normal group and asthenia cold model group. The model group were treated with intramuscular injection of hydrocortisone for 14 days, and the normal group with NS. The content of cyclic adenosine monophosphate (cAMP) and adenylate cyclase (AC), triiodothyronine (T3), thyroxine (T4), dopamine (rT3), cortisol (COR), cyclic guanosine monophosphate (cGMP) was detected by radioimmunoassay (RIA). The content of adenosine triphosphate (ATP) was detected by chemiluminescence. Result The content of T3, T4, rT3, COR, cAMP were decreased, the activity of AC was decreased, the conent of ATP was increased. Conclution The function of the endocrine system was suppressed in asthenia cold rats, which can down-regulate cAMP and lead to asthenia cold syndrome.

The disadvantages of Admas clasp include inconvenient manual adjustment and being unsuitable to the deciduous molars.The modified Admas clasp can overcome the shortcomings.

Objective To investigate the changes in concentrations of the homocysteine (Hey) and other aminothiols (ESRD) in plasma of end-stage renal disease (ESRD) patients before and after hemodialysis (HD). Methods 26 chronic renal failure patients treated with hemodialysis plus 54 healthy controls were randomly chosen. The concentrations of plasma total homocysteine (they), total cysteine ( tCys), total cysteinylg]ycine (tCysGly), total glutathione (tGSH) were determined by HPLC-fluorescence detection (FD). The concentrations of serum lipids were detected and several renal function tests were conducted. Results The concentrations of they ( 16. 70 ± 3.51 μmol/L vs 10. 95±3.07 μmol/L, t =3. 625,P <0. 01),tCys(341.87±70.65 μmoL/L vs 249.76 ± 13.18 μ mol/L,t =6.219,P <0.01), tCysGly(41.33 ± 32. 95 μmol/L vs 31.3 ± 11.78 μmol/L, t = 3. 530, P <0.01 ) in pre-hemodialysis plasma were significantly elevated , and tGSH ( 5.91 ± 0. 08 μmol/L vs 9. 33 ± 2. 62 μ mol/L, t =-5.404, P < 0. 01 ) was significantly decreased compared with the control group. The concentrations of tHey and tCys (11.74 ± 3.42 μmol/L and 272. 67 ± 64. 18 μmol/L) in post-hemodialyais plasma were significantly decreased compared with in pre-hemodiaIysis plasma, but they could not be restored to normal levels. However, the concentrations of tCysGly(41.33 ± 32. 95 μmol/L vs 44. 93 ± 13.88 μmol/L,t =-0.758, P>0.05) and tGSH (5.91±0.08 μmol/L vs 5.93±0.38 μmol/L,t = -0.068,P >0.05) in pre-hemodialysis plasma and post-hemodialysis plasma didn't change significantly. There were significant positive correlations between plasma levels of they and tCys(r =0. 458 2 ,P <0. 01 ). There was significant negative correlations between plasma levels of tHcy and tGSH ( r =-0.609 9, P=0.000 9). Nevertheless, tHcy levels were was not correlated with tCysGly levels and other serum lipid parameters. Conclusion There is a high prevalence of metabolic disturbance in Hcy and other related aminothiols in ESRD patients.

Medical English is an indispensible tool subject for medical students.However,the limited in-class teaching hours fail to provide adequate opportunities for students to participate in a diversity of subject-based tasks to practice medical English.Therefore,extracurricular activities serve as a complement to in-class teaching.Moreover,the features of extracurricular activities conform to those of Content-based instruction ( CBI),a teaching mode adopted in the teaching of ESP ( English for special purposes).The specific forms of extracurricular activities can be designed based on need analysis to cultivate the students' language competence in communicating biomedicine in Medical English.

Objective To investigate the effects of different stabilizers, time and temperature before centrifugation on the stability of homocysteine (Hcy) and other related thiols levels involving EDTA-containing whole blood.Methods Blood was drawn from 17 healthy adults and collected into tubes containing EDTA, EDTA plus NaF and EDTA plus 3-deazaadenosine(3DA),then stored on crush ice(0-4 ℃) immediately or at room temperature(25 ℃).Plasma was separated at 0, 3, 6, 24 and 48 hours, respectively.The levels of plasma total Hcy (tHcy), total cysteine (tCys), tatal cysteinylglycine (tCysGly) and tatal glutathione (tGSH) were measured by HPLC.The plasma immediately separated was used as baseline sample. Results In EDTA tubes stored at room temperature, tHcy levels increased by 38.5%, 64.2%, 141.9%, 225.4% for 3, 6, 24, and 48 h, respectively.The levels of tCysGly and tGSH increased by 20.0% and 37.9% within 3 h, however, tCys decreased by 3.5%.The levels of the thiols increase by less than 5% up to 6 h in EDTA tubes stored on crush ice.In EDTA-3DA and EDTA-NaF tubes, no statistical differences were observed in the plasma levels of tHcy, tCys,tCysGly and tGSH compared with their respective baseline values at room temperature for 3 h(EDTA-3DA tubes:F=0.01,0.94,0.09,0.01,all P>0.05;EDTA-NaF tubes:F=0.85,0.04,0.03,0.02,all P>0.05).Conclusions The EDTA-plasma levels of tHcy and other related thiols are time and temperature-dependent. There is a strong need for standardization of blood sample collection and processing in tHcy and other thiols assays. The plasma concentrations of tHcy, tCys, tCysGly and tGSH were stable for 3 h at least in the EDTA-3DA and EDTA-NaF tubes kept at room temperature.

Objective To study the effect of docosahexaenoic acid ( DHA ) and eicosapentaenoic acid (EPA) on cognition impairment and huntingtin associated protein 1 ( HAP1 ) expression in hippocampus of rat model with Alzheimer' s disease(AD). Methods Forty healthy Sprague-Dawley rats were randomly divided into control group, AD group, DHA group and EPA group on average. Alcl3 was injected intraperitoneally and D-galac tose was injected into subcutaneous to establish the model of rat with AD. ABC method of immunohistochemistry was used to observe the expression level of HAP1 in the hippocampus. Morris water maze was used to study the spatial learning and memory in rats. Results Compared with control group,the HAP1-positive neurons of hippo campus decreased and poorer performance in Morris water maze test was observed in AD group. Compared with AD group, DHA and EPA treatments significantly caused the decreases in escape latency and searching distance in the Morris water maze test. The number of HAP1- positive cells in DG region of DHA group(43.57 ±6.14) increased obviously compared with AD group( 28.56 ± 4.23 ) (P ＜ 0.05 ＝. Conclusion The immunoreactivities of HAP1 decrease in hippocampus of AD rat. The applications of DHA and EPA in AD rats significantly improve the ability of learning and memory;and the mechanisms may be related to the decrease of HAP1 expressions in hippocampus.

Objective To study the effect of cirrhosic liver on dynamic vascular curves analysis f(t)of hepatocellular carcinomas(HCCs) at contrast-enhanced ultrasound by exploring the difference between perfusion parameters of HCCs in cirrhotic liver and that in noncirrhotic liver. Methods One hundred and fifteen HCCs were analyzed off-line with dynamic vascular curve f(t) of Sonoliver. The HCCs were divided into 2 groups based on their background liver as cirrhotic liver group ( n = 86) and noncirrhotic liver group ( n =29). Such parameters as maximum of intensity(IMAX) ,rise time (RT,from 10% to 90% of IMAX),time to peak(TTP) ,mean trasit time(mTT) ,rise slope(RS) and washout time(WT) of the two groups were analyzed by statistics. Results There was no significant difference in the f(t) parameters of HCCs between cirrhotic liver group and noncirrhotic group(P >0. 05) [IMAX:(124. 25 ± 5. 56)% vs (113. 65 ± 5. 58)% ; RT: (12. 98 ± 0. 48)s vs (13. 68 ± 0. 92)s;TTP:(13. 70 ± 0. 52)s vs (14. 39 ± 0. 9)s;mTTi(138. 61 ± 9. 20)s vs (149. 49 ± 21. 70)s;RS:10. 11 ± 0. 60 vs 8. 89 ± 0. 77, WT: (34.17 ± 2. 91 )s vs (28. 36 ± 3. 25)s]. There was also no significant statistical difference in all above parameters in reference regions for the two group (P > 0. 05). Conclusions The f(t) parameters in HCCs can evaluate blood perfusion of the tumors, and cirrhotic liver does not affect the perfusion parameters of HCCs.

The buccoversion malpositon of maxillary second molars is one kind of common malocclusion.It can lead to damages to stoma-tognathic system.The adjustable maxillary molar retractor is an effective tool in the early treatment of this kind of malposition.