[Construction and immunoscreening of cDNA library of Babesia orientalis].

OBJECTIVE: To construct a cDNA library for Babesia orientalis and screen immunologically positive clones. METHODS: Total RNA of B. orientalis in red blood cells from an infected calf was isolated. cDNA was synthesized by reverse transcriptase, amplified by PCR and ligated into lambdaTriplEx2 vector. The recombined vectors were packaged and the unamplified cDNA library was constructed. The cDNA library was then amplified and immunologically screened with rabbit anti-B. orientalis serum. The recombinant lambdaTriplEx2 of positive clones were converted to the corresponding recombinant pTriplEx2. The inserted fragments were identified by PCR amplification. The plasmids were sequenced and compared against GenBank database by Blast. RESULTS: The titer of the unamplified library was 2.0 x 10(6) pfu/ml. The inserted fragment length of the library ranged from 500 to 3,000 bp, and the recombination efficiency accounted for 98.8%. The titer of the amplified library was 5.8 x 10(8) pfu/ml. Three positive clones were selected by serum immunological screening and named B04, B05, and B41, respectively. The inserted fragments of the B04, B05 and B41 were about 1,300 bp, 1,000 bp, and 2,400 bp, respectively. Sequence analysis revealed that the 3 clones contained open reading frames. Blast results showed that they were highly homologous to the nuclear movement protein gene, the hypothetical protein gene and the heat shock protein 70 (HSP70) gene, respectively. The deduced amino acid sequences of B04, B05 and B41 contained 310, 192 and 647 amino acid residues, with Mr of 34,000, 21,000, and 70,700, respectively. CONCLUSION: A qualified cDNA library of B. orientalis has been constructed and three positive clones of B. orientalis discovered.

Transdermal delivery of praziquantel: effects of solvents on permeation across rabbit skin.

To explore a new method for the transdermal delivery of praziquantel (PZQ), the effects of solvents on permeation across rabbit skin were investigated. The solubility of PZQ in five different solvents, ethylene glycol monophenyl ether (EGPE), 1,4-dioxane, tetrahydrofuran, dimethyl sulfoxide, and oleic acid, were measured with a UV-Vis spectrophotometer. The determination of the n-octanol/water partition coefficient of PZQ in the five different solutions and assay of serum concentration following PZQ transdermal administration in rabbits were performed using HPLC. The results indicated that the transdermal absorption of the drug was related to the partition coefficient and lipophilic characteristics of the solvent. The optimal solvent for PZQ transdermal delivery was EGPE in our protocol. The solubility of PZQ in EGPE is >400 mg/ml, and the apparent partition coefficient of PZQ in the solution is 0.895 (log P value). After transdermal administration of PZQ in EGPE solution, the bioavailability is 2.85-fold that after oral administration. The serum drug concentration was maintained at 4.0 mug/ml over 4 h, which is sufficient for the treatment of schistosomiasis. At the same time, no apparent side effects were found on the skin. EGPE may thus be a promising vehicle for the transdermal delivery of PZQ in the future.

The host responses in sheep artificially infected with Theileria sp. (China).

Studies on host responses in sheep artificially infected with Theileria sp. (China) were discussed and summarized mainly on typical high fever periods, merozoits and schizoon observation, antibody response.