0.05).Concentration of ethanol above 1.6 % could obviously suppress enzymatic activity(P0.05).CONCLUSION: A handy and fast screening method for type Ⅱ5?-reductase inhibitors has been set up using UV-spectrophotometry.It may be used to screening drugs for BPH treatment.

AIM: Tranditional methods of screening drugs for benign prostatic hyperplasia(BPH)requires senile male animals such as dogs or rats.It consumes a long time to get the results. Over-expression of type Ⅱ5α-reductase in prastate induces BPH.A fast and efficient screening model of type Ⅱ5α-reductase inhibitors for BPH was set up in this paper.METHODS:Microsomes were extracted from male Sprague-Dawley rat livers by gradient centrifugation.Type Ⅱ5α-reductase enzyme-catalyzed reaction was assayed by UV-spectrophotometry using testosterone as a substrate and NADPH as hydrogen donor.The change of enzymatic activity was recorded with a NADPH wavelength of 340 nm by subtracted descending velocity of the control(without 5α-reductase).Effects at different conditions(temperatures,pH,enzyme and testosterone concentrations)on 5α-reductase were assayed.RESULTS:The suitable condition of type Ⅱ5α-reductase reaction Was defined as concentration of 109.05 mg protein/L enzyme(pH 6.00)with 2 μmol/L testosterone at 37℃.Michaelis'constant of type Ⅱ5α-reductase was 0.6μmol/L.Finasteride,a new drug for BPH,significantly inhibited activity of type Ⅱ 5α-reductase.IC50 of finasteride Was 64.1 nmol/L.As solvent of drugs,concentration of ethanol below 1.1% did not inhibite enzymatic activity(P＞0.05).Concentration of ethanol above 1.6%could obviouslv suppress enzymatic activity(P＜0.01).Daytime difference within five days had no significant difference(P＞0.05).CONCLUSION:A handy and fast screening method for type Ⅱ 5α-reductase inhibitors has been set up using UV-spectrophotometry.It may be used to screening drugs for BPH treatment.

Objective To investigate the effects of crocodilian plasma on 12 bacteria(including G+ bacteria and G-bacteria) lines in vitro.Methods The bacteria CFUs on nutrient broth agar plates were determined after bacteria and crocodilian plasma incubated together for 1h.Then effects of the samples on the survival rate of various concentrations of bacteria were calculated.To evaluate the antibacterial spectrum of crocodilian plasma,the zones of bacterial inhibition were measured through agar disk method.Results and Conclusion Crocodilian plasma had superior bactericidal effects on Escherichia coli M421C1,O111B4,E240-3 LT,Micrococcus catarrhalis,Shiga's bacillus,Pseudomonas aeruginosa and Diplococcus pneumoniae.The results indicated why wound of crocodilian by tearing each other was not susceptible,and crocodilian plasma could be developed a natural antibacterials.

OBJECTIVE:To evaluate the bioequiavailability of the domestic and the imported paracetamol and oxycodone tablets.METHODS:The blood concentrations of paracetamol and oxycodone in22healthy male volunteers were determined by HPLC-MS after a single dose orally1tablet of domestic or imported oxycodone tablet by a randomized crossover way.RE?SULTS:The main pharmacokinetic parameters of the domestic and the imported oxycodone tablets were as follows:C max were(10.4?2.2),(11.1?3.3)?g/L,respectively;t max were(1.05?0.35),(0.92?0.40)h,respectively;t 1/2 ke were(5.36?0.91),(5.53?1.25)h,respectively;AUC 0～t were(44.2?7.9),(44.5?8.3)(?g?h)/L,respectively;AUC 0～∞ were(49.3?9.4),(51.0?11.6)(?g?h)/L,respectively;the relative bioavailability of the domestic preparation was(102.8?27.4)%.The main pharmacokinetic parameters of the domestic and the imported paracetamol were the following:C max were(4612?696),(4592?825)?g/L,respectively;t max were(0.94?0.28),(0.96?0.23)h,respectively;t 1/2 ke were(3.99?0.77),(4.05?0.83)h,re?spectively;AUC 0～t were(15732?3450),(16265?3858)(?g?h)/L,respectively;AUC 0～∞ were(16618?3545),(17205?4194)(?g?h)/L,respectively;the relative bioavailability of the domestic one was(97.6?10.3)%.CONCLUSIONS:The2preparations are bioequivalent.

AIM: To prepare α-tricalcium phosphate (α-TCP)/calcium polyphosphate (CPP) fiber and to study the feasibility of CPP fiber to reinforce calcium phosphate bone cement composites. METHODS: Firstly,α-TCP powder was synthesized using chemical sediment method. Secondly, the α-TCP was mixed with CPP fiber according to different contents and lengths. Finally, bone cement was tempered with firming agent. Solidification time and mechanical property of the samples were measured. Microstructure of hardened sample was observed with scanning electron microscope. RESULTS: When the amount of CPP fibers was 10% and the length was 2 mm, the compressive strength reached 62.5 MPa and the rupture strength reached 12.4 MPa. Scanning electron microscope suggested that CPP fibers with great associativity were well distributed in bone cement. After immersing in Ringer fluid for two months, the CPP fibers did not biodegrade obviously and still had certain function to increase strength and toughness. CONCLUSION: To a certain extent, the CPP fiber can increase strength and toughness of bone cement. Furthermore, α-TCP/CPP composites have good mechanical properties and biocompatibility.

BACKGROUND:When bone cement solidifies fast,the bone cement consistency will be decreased.resulting in difficulty in molding.DESIGN,TIME AND SETTING:Open experiment,performed in the Laboratory of Department of Materials,Lanzhou Jiaotong University between March 2005 and August 2006.gelatin were mixed with citric acid to produce hardening liquid.Then bone cement power and hardening liquid were mixed to form a paste,I.e.,bone cement.METHODS:Setting time of bone cement was determined using a Vicat apparatus.The compressive strength of bone cement at different proportions was tested using MTS-810 material tester.After 2 months of physiological saline soaking at 37℃.the microstructure of solidified bone cement was observed using scanning electron microscope.MAIN OUTCOME MEASURES:Setting time and compressive strength of bone cement,pH value of hydrated bone cement and the microstructure.RESULTS:After adding chitosan and gelatin in the hardening liquid.the consistency of the concoction obviously increased,the setting time became a little longer and the water-resistance of samples was enhanced.therefore the samples could be easily molded.But the compressive strength of the bone cement decreased a little.The pH value of the hydrated bone cement increased gradually with time and was close to the pH value of physiological saline at hour 24.The compressive strength of bone cement was achieyed at 24 hours and it almost did not change after 48 hours.the drawback of ceramic HA,including sintering and difficulties in shaping.It has the characteristics of simple-producing,easy application and low heat energy.

T A R D N A-binding dom ain protein 43 (T D P-43) is a highly conserved and w idely expressed nuclear protein. N ow adays, the expression of T D P-43 can be found in m ost neurodegenerative diseases such as A lzheim er's disease, w hich m akes it becom e a neurodegenerative disease associated m arker pro-tein. From the current research status at hom eland and abroad, and around the relationship betw een the expression of T D P-43 and brain injury, this article em phatically probes into the specific expression and function of T D P-43 in acute and chronic brain injury based on the know ledge of its biological charac-teristics, w hich aim s to explore the feasibility for determ ining the cause of death and the injury and dis-ability situations by T D P-43 in forensic pathology.