Microspheres made of poly-lactic-co-glycolic acid (PLGA) have been frequently proposed as drug delivery systems.A very significant challenge in the development of controlled PLGA releasing systems is the instability of drugs especially therapeutic peptides and proteins.Additional approaches,particularly the use of additives,are needed to optimize PLGA delivery of drugs.This article reviews the effects of additives,especially the effects of stabilizing protein during the preparation of PLGA microsphere and the sustained drug releasing processes.

Objective To compare the effects of different doses of dexmedetomidine on the median effective concentration (EC50) of ropivacaine for epidural block and investigate the appropriate dose.Methods One hundred and twenty ASA Ⅰ patients of both sexes,aged 20-55 yr,weighing 50-75 kg,scheduled for knee arthroscopic operation,were randomly divided into 4 groups (n =30 each):no dexmedetomidine group (group D0),0.25 μg/kg dexmedetomidine group (group D0.25),0.50μg/kg dexmedetomidine group (group D0.50),and 1.00μg/kg dexmedetomidine group (group D1.00).In group D0,ropivacaine 20 ml was injected into epidural space.The ropivacaine-dexmedetomidine mixtures containing 0.25,0.50 and 1.00 μg/kg dexmedetomidine were injected into epidural space in groups D0.25,D1.00 and D0.50 respectively.The volume of mixtures was 20 nl in groups D0.25,D1.00 and D0.50.The initial concentration of ropivacaine was set at 0.40 ％,0.40 ％,0.28 ％ and 0.20 ％ in groups D0,D0.25,D0.50 and D1.00 respectively and then the EC50 was determined by up-and-down technique.The concentration of ropivacaine was increased/decreased by 0.02％ in the next patient.The analgesic effect was assessed using VAS score.VAS score =0 was considered as effective analgesia.The EC50 and 95％ confidence interval (CI) of ropivacaine were calculated using probit method.Adverse effects were recorded.Results The EC50 and 95 ％ CI of ropivacaine was 0.38％ (0.35-0.41)％,0.34％ (0.31-0.36)％,0.22％ (0.20-0.24)％ and 0.14％ (0.12-0.15) ％ in groups D0,D0.25,D0.50 and D1.00 respectively.The EC50 of ropivacaine was decreased gradually in groups D0,D0.25,D0.50 and D1.00 ( P ＜ 0.05).Compared with group D0,the incidonce of hypotension and bradycardia was significantly increased in group D1.00 ( P ＜ 0.05),while no significant change was found in the incidence of adverse effects in groups D0.25 and D0.50 (P ＞ 0.05).Conclusion The appropriate dose of dexmedetomidine for epidural analgesia is 0.50 μg/kg.

BACKGROUND:Huperzine A is a reversible choline enzyme(CHE) inhibitor initially developed in China,which has favorable therapeutic effectiveness in benign memory dysfunction,and could significantly promote the learning process and memory reappearance in rodent animals. OBJECTIVE:To comprehend the impacts of Huperzine A on the enhancement of learning, memory and behavior in platform and maze experiments in D Galoctose(Gal) induced senile mouse model. DESIGN:A randomized and controlled trial. SETTING:Institute of Pharmaceuticals of Xinxiang Medical College. MATERIALS:Study was performed in the Laboratory of Physiology and the Institute of Pharmaceuticals of Xinxiang Medical College from January to December in 2002.A total of 100 healthy Kunming mice were selected for platform and electric maze experiments with 50 mice in each experiment.Huperzine A tablet was obtained from Henan Zhulin Zhongsheng Pharmaceutical Company Limited(batch number:031001).D Gal is the product of Shanghai No.2 Reagent Factory. MAIN OUTCOME MEASURES:The latency in the safe area on the platform and the times of electric shock occurred within 5 minutes were observed in mice in platform experiment;the times of the mice mistakenly escaping to the right electric attacking area were observed in mice in electric maze experiment. CONCLUSION:Huperzine A can effectively improve the learning and memory ability of D Gal induced senile mice, and there is dose effect relationship within certain range. Qiu PY,Chen ZY,Wang YX,Zhang JX,Wu ZZ.Effects of Huperzine A on the memory and behavior in D galactose induced senile mice.Zhongguo Linchuang Kangfu 2005;9(4):247- 9(China) [www.zglckf.com]

Objective To study the biocompatibility of bone marrow mesenchymal stem cells (BMSCs) on acellular collagen matrix double-layer material.Methods BMSCs with acellular collagen matrix double-layer material were trained as experimental group,while separately cultured BMSCs as control group.The growth and proliferation of BMSCs on acellular collagen matrix double-layer material were investigated.Scanning electron microscope was used to observe the adherence of cells,and cell vitality was detected by CCK-8 method.Results The acellular collagen matrix double-layer material did not influence the growth and proliferation of BMSCs.The difference between the growth curves of experimental group and control group was not significant (P＞0.05).Conclusions The acellular collagen matrix double-layer material has acceptable biocompatibility.This research provides a scientific basis for the application of this composite material.

Objective To evaluate the damaged level of auditory processing and diagnose the type of language impairment in an auditory agnosia patient using Psycholinguistic Assessment in Chinese Aphasia (PACA), and predict the outcome of the language function. Methods A patient with a bilateral damage involving the temporal lobe could physically hear the sounds, but was unable to recognize or differentiate between the sounds. Speech and language evaluations were taken with PACA 4 weeks, 8 weeks and 3 months after the onset of disease. Results At 4 weeks, the correct rates were 2.5% and 95.0% in spoken word-picture matching and written word-picture matching (P<0.001), and were 5.6% and 80.6% in spoken semantic knowledge and written semantic knowledge (P<0.001). The scores of auditory input processing function score were low, including phoneme discrimination, spoken word matching with minimal differences, environmental sounds identification. The correct rates were 67.5% in oral picture naming, 0 in word repetition, 70.0% in word reading, 0 in dictation, 100.0% in directly copy writing. At 8 weeks and 3 months, there was complete recovery in written word- picture matching (both 100%) and written semantic knowledge (97.2%, 100%), and improvement in oral picture naming (87.5%, 90%), word repetition (87.5%, 97.5%), picture name writing (77.5%, 87.5%) and copy writing (both 100%) (P<0.05). But no change was found in auditory input processing function examinations, spoken word-picture matching (5.0%, 7.5%), spoken semantic knowledge (2.8%, 5.6%), word repetition (0, 3.3%) and dictation (both 0). Conclusion The patient was diagnosed as auditory agnosia with the inability to distinguish sounds. PACA can well identify the impaired level of auditory comprehension disorder and the outcome of language function recovery for aphasics.

Objective To investigate and design a coincidence detection system for an all-digital small animal PET scanner and evaluate its preliminary performance properties.Methods This coincidence module adopted a coincidence identification mode based on singles data in list-mode.Using digital signal processing technology,energy calibration,crystal identification,timing alignment and coincidence events extraction were performed on singles data in list-mode.The obtained data could be used for image reconstruction.Results The 13 × 13 crystal array was well recognized by the position histogram of one lutetium yttrium orthosilicate (LYSO) crystal block.In the coincidence timing histogram of the micro-Derenzo phantom,1.36 ns full width at half maximum was obtained.The rods with a diameter of 1.2 mm were clearly displayed in the reconstructed image of the micro-Derenzo phantom.Conclusion The coincidence module can provide satisfactory performance to meet the design needs of an all-digital small animal PET scanner.

Objective To investigate the correlation between human epidermal stem cell (hESCs) and hypertrophic scar or keloid. Methods Improved collagen Ⅳ-coated adhesion methods was used to isolate and culture the epidermal stem cells after neutral protease selectively digested the dermo-epidermal junctions. After the cells were cultured and expanded in vitro, and passage 3 hESCs were induced by different concentrations of TGF-β1 (0.1, 5.0, and 10.0 ng/ml). Morphological fea-tures and identification of these cells were meseasured by HE, Masson, immunohistochemical staining on the days 3 and 7, respectively. Results After induced by TGF-β1 for 3 and 7 days, the morpholo-gy of the epidermal stem cell (hESCs) was changed into fusiform shape, similar to fibroblasts. 70 % ofthe cell which was induced by TGF-β1 were blue stained in the cytoplasm by Masson stain, which is the distinctive method for collagen, suggesting collagen appeared or increased in the cells. The collagen concentrations in supernatants of hESCs were 0.4150±0.0014, 0.3380±0. 0020, and 0.3870±0.0020, much higher than that in control group (0.0780±0.0025) and normal skin fibro-blast group (0.15004±0.0051) (P<0.05). Immunohistochemical staining revealed that positive rates of these cells for anti-vimentin staining were more than (95.00±1.20)% in experiments and (5.70±0.20)% in control group. Conclusion The differentiantion of hESCs induced by TGF-β1 into fibro-blasts indicates that hESCs may play a role in the pathogenesis of hypetrophic scar and keloid.

BACKGROUND: Eggembryosin is characterized by tonifying kidney and vital essence, invigorating qi and spleen, replenishing and activating blood, beautifying and nourishing face, and improving constitution of whole organism.OBJECTIVE: To observe the influence of eggembryosin on aging index,quantity of hemocytes and quality of immune organs of animal models, and analyze its effect on cosmetology, anti-senility and immunoloregulation.DESIGN: Randomized controlled observation.SETTING: Department of Pharmacology, Xinxiang Medical College.MATERIALS: The experiment was carried out in the Department of Pharmacology of Xinxiang Medical College between April 1998 and September 2002. A total of 80 Kunming mice of both sexes were selected in this study.METHODS: ① Effect of eggembryosin on activity of superoxide dismutase (SOD) in serum, content of malondialdehyde (MDA), lipofuscin and hydroxyproline respectively in serum, liver and tendon of tail of aging mice: Thirty mice were divided into 3 groups according to randomly lined table, including eggembryosin group, D-galactose model group and normal control group with 10 in each group. The former two groups were injected with D-galactose to copy aging models, and eggembryosin group were perfused with eggembryosin to measure activity of SOD in serum, content of MDA, lipofuscin (aging index) and hydroxyproline (elasric index of skin) respectively in serum, liver and tendon of tail. ② Effect of eggembryosin on mass of immune organs of mice with low immunological function: Thirty mice were selected and divided as the same way mentioned above. Mice in eggembryosin group were perfused with eggembryosin. In addition, those in eggembryosin group and cyclophosphamide (CAP) group were peritoneally injected with CAP to copy immunosuppression models and calculate index of thymus (spleen) (mg/g) = weight of thymus (spleen)/body. ③ Effect of eggembryosin on quantities of erythrocytes and hemoglobin of mice with blood deficiency: Twenty mice were divided into 2 groups according to randomly lined table, including eggembryosin group and normal control group with 10 in each group. Values of erythrocytes and hemoglobins of mice were measured before administration. Models in types of blood-deficiency blood-loss were copied with tail xsanguinations, and then, mice were perfused with eggembryosin and saline, respectively. Blood of mice were collected from their tails to measure values of erythrocytes and hemoglobin.MAIN OUTCOME MEASURES: Activity of superoxide dismutase (SOD) in serum, content of malondialdehyde (MDA), lipofuscin and hydroxyproline respectively in serum, liver and tendon of tail of aging mice, index of thymus, and spleen, contents of blood erythrocytes and hemoglobins.RESULTS: A total of 80 mice were involved in the final analysis without any loss. ① Activity of SOD in serum and contents of hydroxyproline in tendon of tail of mice in eggembryosin group were significantly higher than those of mice in D-galactose model group (P ＜ 0.01); content of MDA in serum and content of lipofuscin in liver of mice in eggembryosin group were significantly lower than those of mice in D-galactose model group (P＜ 0.01). ② Indexes of thymus and spleen of mice in eggembryosin group were higher than those of mice in CAP group (P ＜ 0.05-0.01). ③ Increasing values of blood erythrocytes and hemoglobin of mice in eggembryosin group were significantly higher than those of mice in normal control group (P ＜ 0.01).CONCLUSION: Eggembryosin taken orally can improveanti-oxidation of organism and elasticity of skin, increase quality of immune organs damaged by CAP and immunological function, and nourish the blood.

Objective To investigate the effect of dexmedetomidine on inflammatory response during the perioperative period in patients with acute craniocerebral trauma.Methods Seventy ASA Ⅰ-Ⅳ patients of both sexes,aged 20-68 yr,with craniocerebral trauma,who required decompressive craniectomy within the next 24 h,were randomly divided into 2 groups (n =35 each) ∶ control group (group C) and dexmedetomidine group (group D).Anesthesia was induced with fentanyl,propofol and cisatracurium and maintained with remifentanil,sevoflurane and propofol and intermittent iv boluses of cisatracurium.In group D,dexmedetomidine 1 μg/kg was infused over 10 min,followed by infusion at 0.4 μg· kg-1 · h-1 for 2 h.Venous blood samples were taken before induction of anesthesia (baseline),2 h after the beginning of operation,at the end of operation and at 24 h after operation (T1-T4) to determine the concentrations of serum neurone specific enolase (NSE),interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α).Results Compared with group C,the concentrations of serum NSE,IL-6 and TNF-α were significantly decreased in group D (P ＜ 0.05).The concentrations of serum NSE,IL-6 and TNF-αwere significantly higher at T2 and T3,and the concentration of serum TNF-α was significantly lower at T4 than at T1 in group C (P ＜ 0.05).The concentrations of serum NSE and IL-6 were significantly higher at T2 and T3 and lower at T4 and the concentration of serum TNF-α was significantly higher at T3 and T4 than at T1 in group D (P ＜0.05).Conclusion Dexmedetomidine protects the brain against acute craniocerebral trauma by inhibiting systemic inflammatory response during the perioperative period.

Objective To investigate the effect of KCNQ2/3 channel opener retigabine on the median effective dose (ED50) of bupivacaine and chloroprocaine for induction of convulsion in mice and the relationship between KCNQ2/3 channels and the neurotoxicity of local anesthetics.Methods Pathogen-free female Kunming mice,weighing 20-30 g,were used in the study.The experiment was performed in two parts.Part Ⅰ Sixty mice were randomly divided into 2 groups (n =30 each):control group (group C) and retigabine group (group R).The C and R groups were further divided into 3 subgroups with different doses of chlorprocaine (C + L1,C + L2 and C+ L3 groups,and R+ L1,R+ L2 and R+ L3 groups,n =10 each).In groups C and R,0.9％ normal saline 0.005 ml/g and retigabine 20 mg/kg were injected intraperitoneally,respectively,and chlorprocaine was injected intraperitoneally 20 min later.The doses of chlorprocaine were 150.0,172.5 and 198.4 mg/kg in C + L1,C + L2 and C + L3 groups,respectively,and 198.4,228.2 and 262.4 mg/kg in R+ L1,R+ 12 and R+ L3 groups,respectively.Part Ⅱ Eighty mice were randomly divided into 2 groups (n =40 each):control group (group C) and retigabine group (group R).The C and R groups were further divided into 4 subgroups with different doses of bupivacaine (C + B1,C + B2,C + B3 and C + B4 groups,and R + B1,R + B2,R + B3 and R + B4 groups,n =10 each).In groups C and R,0.9％ normal saline 0.005 ml/g and retigabine 20 mg/kg were injected intraperitoneally,respectively,and bupivacaine was injected intraperitoneally 20 min later.The doses of bupivacaine were 37.8,43.5,50.0 and 57.5 mg/kg in C + B1,C + B2,C + B3 and C + B4 groups,respectively,and 50.0,57.5,66.1 and 76.0 mg/kg in R + B1,R + B2,R + B3 and R + B4 groups,respectively.The ED50 and 95％ confidence interval (CI) of bupivacaine and chloroprocaine for induction of convulsion were calculated by Probit analysis.Results The ED50(95％ CI) of chloroprocaine was 165.3 (155.8-175.0) mg/kg,and the ED50(95％CI) of bupivacaine was 41.1 (36.7-44.5) mg/kg in C group.The ED50 (95％ CI) of chloroprocaine was 212.4 (200.2-224.3) mg/kg,and the ED5o (95％ CI)of bupivacaine was 51.5 (945.1-56.0)mg/kg in R group.Compared with group C,the ED50 of bupivacaine and chloroprocaine for induction of convulsion was significantly increased in group R (P ＜ 0.01).Conclusion KCNQ2/3 channel opener retigabine can significantly increase the ED50 of bupivacaine and chloroprocaine for induction of convulsion and reduce convulsion induced by bupivacaine and chloroprocaine in mice,indicating that the neurotoxicity of local anesthetics is related to inhibition of KCNQ2/3 channels.