Objective To evaluate the effect of dexmedetomidine administered locally on the median effective concentration ( EC50 ) of ropivacaine for paravertebral nerve block ( PVNB) . Methods Forty?eight ASA physical status Ⅰ or Ⅱ female patients, aged 20-64 yr, with body mass index<24 kg∕m2 , scheduled for elective unilateral segmental mastectomy under PVNB, were randomly divided into 2 groups ( n=24 each) using a random number table: ropivacaine group ( group R) and ropivacaine mixed with dexmedetomidine group ( group RD) . PVNB was performed at T4 on the operated side guided by ultrasound and nerve stimulator. Ropivacaine 20 ml and a mixture of ropivacaine and 20 μg dexmedetomidine 20 ml were injected locally in group R and group RD, respectively. The concentration of ropivacaine was determined by up?and?down sequential allocation. The initial ropivacaine concentration was set at 0. 35%, and the ratio between the two successive concentrations was 1. 2. The EC50 and 95%confidence interval of ropivacaine were calculated using Dixon?Massey method. Results The EC50 ( 95%confidence interval) of ropivacaine was 0.27% (0.23%-0.30%) and 0.22% (0.18%-0.25%) in group R and group RD, respectively. Compared with group R, the EC50 of ropivacaine was significantly decreased by 19% in group RD. Conclusion Small dose of dexmedetomidine administered locally can significantly enhance the efficacy of PVNB with ropivacaine.

Some biological properties of eperythrozoon, such as the influence of low temperature on their viability, their infectivity in different kinds of animals and their changes in amount of organisms in vivo were investigated in the present study. The experimental results showed that the viability of eperythrozoon could be maintained at -20 ℃ for 835 days and at 4 ℃ for 205 days. Small rats could be infected by Eperythrozoon suis, while chickens were not infected. The basic regulation on the changes in amount of organisms in animals was expressed by the fact that the percentages of erythrocytes being infected increased rapidly up to 96-98% 2-4 hours after infection, then it dropped down and followed by dropping and re-rising, attaining its climax up to 8 hours after infection. Finally, it reflected a fluctuating cycle of 14-16 hours. This results showed that eperythrozoons can maintain their viability at -20℃ for a long time and they possess relative species specificity to host with a reproduction cycle of 14-16 hours in animal body.

Objective To investigate the effects of morroniside on fibrinogen (Fib), prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) in focal cerebral ischemia/reperfusion in rats. Methods The animal model was induced with occlusion of middle cerebral artery (MCAO) with suture embolus, and morroniside was then administered intragastrically at the dose of 30, 90 and 270 mg/kg for 7 d. Acetyl salicylic acid was taken as positive control drug. The content of Fib, and PT, APTT and TT were measured withrelated kits. Results Compared with the sham-operated group, the concentration of Fib significantly increased (P<0.001) and PT, APTT and TT significantly shortened in the model group (P<0.001); however, compared with the model group, morroniside significantly decreased Fib content (P<0.01) and prolonged PT, APTT and TT (P<0.05). Conclusion Morroniside can antagonize the coagulation function in focal cerebral ischemia/reperfusion in rats.

Parkinson's disease is a common progressive neurodegenerative disorder among old people, characterized by progressive loss of dopamine-producing neurons in the substantia nigra pars compacta and accordingly low level of dopamine in the nigrostriatal pathway.Neuroinflammation and even systemic inflammation have been suggested to be involved in the demise of dopaminergic neurons. Anti-inflammatory treatment could protect brain from inflammatory injury and prevent the progressive course of Parkinson's disease, which suggests a potential new strategy for Parkinson's disease treatment.