[Research progress on antimicrobial peptides against malaria parasite].

Antimicrobial peptides have broad-spectrum antibacterial activity and high thermal stability. Researches prove that they can inhibit the development of Plasmodium or kill them. The paper focuses on research advances in their biological characteristics, natural or synthetic peptides as potential anti-Plasmodium agents in malaria research.

[Porcine MSC-derived CLC induced by rabbit's cardiomyocytes extract did not induce immune reaction in vivo].

OBJECTIVE: To compare the in vivo immune reaction of transplanting porcine MSC-derived CLC with rabbit cardiomyocytes extracts induced differentiation or in vitro cultured porcine MSC. METHODS: After injecting the MSC-derived CLC or MSC to the original porcines, the number of CD4+, CD8+ T cells were determined by flow cytometry. The serum concentrations of IL-2, IL-4 were measured by ELISA, and the porcine spleen lymphocyte CTL cytotoxicity was determined by Cell Counting Kit-8 Assay. RESULTS: The numbers of CD4+ and CD8+ T cells, the serum concentrations of IL-2, IL-4 and spleen lymphocyte CTL cytotoxicity were all similar in porcines received MSC-derived CLC induced by rabbit's CMs extract or MSC transplantation. CONCLUSION: The porcine MSC-derived CLC induced by rabbit's CMs extract did not induce extra immune reaction when injected back to the original porcine.

The interfacial dilational properties of hydrophobically modified associating polyacrylamide studied by the interfacial tension relaxation method at an oil-water interface.

The interfacial dilational viscoelastic properties of hydrophobically associating block copolymer composed of acrylamide (AM) and a low amount of 2-phenoxylethyl acrylate (POEA) (<1.0 mol%) at the octane-water interfaces were studied by means of the interfacial tension relaxation method. The dependencies of interfacial dilational elasticity and viscous component on the dilational frequency were investigated. The interaction of hydrophobically associating block copolymer [P(AM/POEA)] with sodium dodecyl sulfate (SDS) has been explored. The results show that at lower frequency, the dilational elasticity for different concentration copolymer is close to zero; at higher frequency, the dilational elasticity shows no change with increased frequency; At moderate frequency (10(-3)-1 Hz), the dilational elasticity decreased with a decrease in the dilational frequency. The results show that the hydrophobic groups of [P(AM/POEA)] chains can be associated by inter- or intrachain liaisons in water solution. The dilational viscous component for P(AM/POEA) comes forth a different maximum value at different frequencies when the polymer concentration is different. It is generally believed that the dilational viscous component reflects the summation of the various microscopic relaxation processes at and near the interface and different relaxation processes have different characteristic frequencies. The spectrum of dilational viscous component may appear more than once maximum values at different frequencies. The influence of SDS on the limiting dilational elasticity and viscous component for polymer solution was elucidated. For 5000 ppm polymer solution, the limiting dilational elasticity decreased with an increase in SDS concentration. The dilational viscous component passed through a maximum value with a rise in the dilational frequency, which appeared at different frequency when SDS concentration is different; and the higher is the concentration, the lower is the dilational frequency. It can be explained that macromolecules may be substituted by SDS molecules in the interface and the interaction of molecules decrease, which makes the limiting dilational elasticity decrease. For 200 ppm polymer solution, the limiting dilational elasticity increased firstly and then decreased with SDS concentration increasing. This may be explained that the interfacial polymer concentration is so low that SDS molecules absorbed in the interface dominate dilational properties of the interfacial film even at very low SDS concentration. However, SDS molecules can gradually substitute the polymer molecules in the interface with a rise in SDS concentration, which results in the decrease in the limiting dilational elasticity.

[Study on biological characteristics of cypermethrin-resistant and -susceptible strains of Aedes albopictus at different temperatures].

OBJECTIVE: To study the biological characteristics of cypermethrin-resistance strain and -susceptible strain of Aedes albopictus under different controlled temperatures in the laboratory. METHODS: The two strains were raised at three different temperatures, 20, 25 degrees C and 28 degrees C respectively, and the biological characteristics of the two mosquito strains, such as reproduction, 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 degrees C, 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 temperature 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 degrees C and 20 degrees C. 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 temperature, the development timing of the resistance strain was longer than that of the susceptible strain, and the period was the longest under 28 degrees C (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 degrees C and 20 degrees C. The differences show statistic significance (P < 0.05). CONCLUSION: The resistance of A. albopictus to cypermethrin results in the decrease of adaptability to the environment change and the disadvantage of reproduction at different temperatures.

[Progress in application of genetic control of mosquitoes].

With the specific, environmental-friendly, fast and efficient characteristics, the genetic control of mosquitoes has been preliminary shown a good effect. However, the prejudices and misunderstandings to the genetic control limit its popularization and application. Therefore, in order to re-recognize and take full advantage of this method, the recent progresses towards applying the genetic control of mosquitoes are reviewed.

Identification of TCT, a novel knockdown resistance allele mutation and analysis of resistance detection methods in the voltage-gated Na⁺ channel of Culex pipiens pallens from Shandong Province, China.

The present study aimed to investigate deltamethrin resistance in Culex pipiens pallens (C. pipiens pallens) mosquitoes and its correlation with knockdown resistance (kdr) mutations. In addition, mosquito­resistance testing methods were analyzed. Using specific primers in polymerase chain reaction (PCR) and allele-specific (AS)-PCR, kdr gene sequences isolated from wild C. pipiens pallens mosquitoes were sequenced. Linear regression analysis was used to determine the correlation between the mutations and deltamethrin resistance. A kdr allelic gene was cloned and sequenced. Analysis of the DNA sequences revealed the presence of two point mutations at the L1014 residue in the IIS6 transmembrane segment of the voltage­gated sodium channel (VGSC): L1014F, TTA→TTT, replacing a leucine (L) with a phenylalanine (F); L1014S, TTA→TCA, replacing leucine (L) with serine (S). Two alternative kdr-like mutations, L1014F and L1014S, were identified to be positively correlated with the deltamethrin-resistant phenotype. In addition a novel mutation, TCT, was identified in the VGSC of C. pipiens pallens. PCR and AS-PCR yielded consistent results with respect to mosquito resistance. However, the detection rate of PCR was higher than that of AS-PCR. Further studies are required to determine the specific resistance mechanism. PCR and AS-PCR demonstrated suitability for mosquito resistance field tests, however, the former method may be superior to the latter.