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Objective To investigate the density seasonal fluctuation and insecticide resistance of Anopheles sinensis in the Taibai Lake area and to provide a scientific basis for formulation of Anopheles sinensis control strategy.Methods The surveillance was carried out from June to October in 2013-2016.The adult mosquito density was monitored using human bait trapping method.WHO bioassay method was used to measure the sensibility of mosquitoes to insecticides.Results In 2013-2016,totally 2 318 Anopheles sinensis were captured,the Anopheles sinensis peaked in late July till early August,which were 67-127,317-386,77-89,107-139,respectively.Anopheles sinensis showed high resistance to dichlorodiphenyltrichloroethane,malathion,and initial resistance to propoxur and deltamethrin (mortality ratio:38.10％,41.82％,86.11％,83.02％).Conclusions The Taibai Lake area has a diverse Anopheles sinensis population,its seasonal fluctuations and insecticide resistance monitoring can provide effective guidance for malaria control.In order to prevent the development of resistance to the insecticides,integrated management measures should be adopted in the future.
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Objective To study the biological characteristics of cypermethrin?resistance strain and?susceptible strain of Ae?des albopictus under different controlled temperatures in the laboratory. Methods The two strains were raised at three different temperatures 20 25℃and 28℃respectively and the biological characteristics of the two mosquito strains such as reproduc?tion development and life expectancy were observed and recorded in the laboratory. Results The life expectancy of both strains became shorter as the temperature raised and the resistant strain 69.37%± 0.01% 77.04%± 0.07% lived shorter than the susceptible strain 85.24%±0.03% 88.23%±0.05% in average. Under 25℃ the hatching rate of resistant strain decreased by 25.88% and the pupation rate decreased by 11.18%. In the three temperatures all the life expectancy expanded as the tem?perature went up the periods for the susceptible strain were 19.75±0.10 23.65±0.07 d and 25.08±0.08 d under 28 25℃and 20℃. While life expectancy for the resistant strain decreased to 17.21±0.09 20.95±0.09 22.58±0.10 d. Under the same tem?perature the development timing of the resistance strain was longer than that of the susceptible strain and the period was the longest under 28 ℃ 156.2 h 137.1 h . In the three temperatures all the development periods expanded as the temperature went up the susceptible and resistant larvae developed 137.1 d and 163.3 d 247.7 d and 156.2 d 182.3 d and 263.2 d under 28 25℃and 20℃. The differences show statistic significance P<0.05 . Conclusion The resistance of A. albopictus to cy?permethrin results in the decrease of adaptability to the environment change and the disadvantage of reproduction at different temperatures.
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Objective To investigate the existence of genetic divergence of sympatric populations of Anopheles sinensis of different feeding preferences based on the rDNA-ITS2 sequence differences. Methods A large number of wild anopheles popu-lations were trapped all night by man-baited net and calf-baited net that had been set up between high-density natural villages of An. sinensis populations and vector-breeding sites,from which two groups of An. sinensis were separated by morphological iden-tification and brought back to the lab for conventional breeding. A large closed greenhouse which temperature and humidity was appropriate was selected as research settings of mark-release-recapture methods by female mosquitoes ,in the center of which above An. sinensis populations baited by man and calf and respectively correspondingly marked by red and yellow phosphors were released in together,in each side of which An. sinensis were recaptured simultaneously by man-baited net and calf-baited net. An. sinensis populations trapped by man twice were brought back to the lab and bred with man-blood,correspondingly ones trapped by calf with calf-blood. Man-preferring and calf-preferring strains were screened respectively from An. sinensis which had been baited by man and calf by the mark-release-recapture methods after parent and F1 mosquitoes,and sequencing and aligning of both rDNA-ITS2 were conducted via PCR amplification. Results The recapture ratios of wild parental mosquitoes An. sinensis of man-preferring group by man-baited net and calf-baited net were 54.07%(339/627)and 45.93%(288/627)re-spectively,and ones of calf-preferring group by man-baited net and calf-baited net were 58.01%(409/705)and 41.99%(296/705)respectively. Two groups of parental mosquitoes trended towards selecting the original blood hosts in host-seeking prefer-ence(χ2=19.42,P<0.01). The recapture ratios of F1 mosquitoes An. sinensis of man-preferring group by man-baited net and calf-baited net were 63.43%(765/1 206)and 36.57%(441/1 206),and ones of calf-preferring group by man-baited net and calf-baited net were 68.22%(1 039/1 523)and 31.78%(484/1 523). Two groups of F1 mosquitoes had more significant characteris-tics of selecting the original blood hosts in host-seeking preference(χ2=271.69,P<0.01)and showed the genetic differentia-tion phenomenon,but the results of sequencing and aligning of the rDNA-ITS2 via PCR amplification showed no difference in base sequence between the two strains and both were 469 bp. Conclusions The genetic divergence based on the rDNA-ITS2 se-quence does not happen in An. sinensis sympatric populations of different feeding preferences.
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BACKGROUND: The free radicals induced by cerebral ischemia/reperfusion consist mainly of xanthine oxidase, which induces cell swelling in the infarcted area.OBJECTIVE: To observe the changes of cerebral ischemia/reperfusioninduced changes in the activity of cerebral superoxide dismutase (SOD), an enzyme responsible for free radical clearance, and investigate the effect of apurin, a inhibitor of purine oxidase, on cellular water content in the brain tissue with ischemia/reperfusion injury.DESIGN: Completely randomized controlled study.SETTING: Department of Neurology of the Central Hospital Affiliated to Shenyang Medical College, Department of Neurosurgery of the First Hospital Affiliated to China Medical University, and Liaoning Provincial Orthopedic Hospital for Limb Disabilities.MATERIALS: The experiment was conducted in the Laboratory of the Central Hospital Affiliated to Shenyang Medical College from May 2003 to April 2004. Forty Wistar rats were subjected to a 6-hour cerebral ischemia and randomized into 4 equal groups to receive intragastric administration of 100 mg/kg apurin (ischemia + apurin group), oxolinic acid suspension of the same dose (ischemia+ oxolinic acid group), 100 mg/kg apurin after a 2-hour reperfusion (Ischemia/reperfusion + apurin group), or oxolinic acid of the same dosage after the 2-hour reperfusion (ischemia/reperfusion + oxolinic acid goup), respectively. The rats in apurin group had intragastric administration of 100 mg/kg apurin 48, 24 and 1 hour before occlusion of the cervical internal carotid artery (CICA) to induce the ischemia, respectively. Oxolinic acid was given in the two oxolinic acid groups in the same manner.METHODS:Water content of brain tissue of rats was measured after 6 hours of CICA occlusion in the two ischemia groups and after the 2-hour perfusion in the two ischemia/reperfusion groups. Distribution of SOD in the brain tissue was observed with SOD immunostaining.MAIN OUTCOME MEASURES: Distribution of SOD and water content in the brain tissue of rats.RESULTS: In the two oxolinic acid groups, Cu-Zn SOD staining identified obviously increased staining intensity in the ischemic foci. Mn SOD staining in ischemia+oxolinic acid group resulted in increased circular staining surrounding the vessels in the ischemic foci, with also obvious staining of the vascular wall and neural cells. The ischemic foci of the ischemia/reperfusion + oxolinic acid group showed diffuse but lightly weaker staining. Cu-Zn SOD staining in the two apurin groups revealed no significant difference. In the two oxolinic acid groups, endothelial cell nuclear swelling of the arteriole, protrusion of the mid-layer myocytes, and expansion of the vascular membrane were observed, with the tissues surrounding the vessels appearing spongy. These changes were less severe in the two apurin groups. The water content in the brain tissue was (78.56±0.30) % in ischemia + apurin group and (78.85±0.49) % in ischemia/reperfusion + apurin group, significantly lower than that of (79.08±0.33) % in ischemia + oxolinic acid group and (79.86±0.49) % in ischemia/reperfusion + oxolinic acid group (P ＜ 0.05).CONCLUSION: Apurin can relieve tissue injury after cerebral ischemia/reperfusion by inhibition of SOD.
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To provide the basis for preparation of diagnostic kits and vaccines in Toxoplasma gondii infection, the gene coding for the qualified recombinant p30 protein (SAG1) of this parasite was amplified by PCR, and the amplified gene was cloned into prokaryotic expression vector pET-30a(+) to construct the recombinant plasmid, and then transformed to E.coli DH5α. The positive recombinant plasmid was screened by PCR and double enzymes digestion, and the nucleotide sequence of p30 gene was determined by automated DNA sequencing. Meanwhile, the identified recombinant plasmid was transformed to E.coli BL21(DE3) with the expression of p30 on bacteria induced by IPTG and the expressed protein was identified by SDS-PAGE. The protein obtained was then further purified and refolded, and its biological activity was checked by Western blotting. It was shown that the size of the amplified gene was 750 bp with molecular weight of 30 ku, and this protein could specifically react with monoclonal antibody against p30 protein.