ABSTRACT
BACKGROUND:Cycloserine with low hepatotoxicity exhibits no cross-resistance with the existing anti-tuberculosis drugs,and has been commonly used for the treatment of drug-resistant tuberculosis.However,its oral administration or injection leads to a certain degree of neurotoxicity.OBJECTIVE:To prepare poly(lactic-co-glycolic acid) (PLGA)-cycloserine sustained-release microspheres which are expected to reduce the neurotoxicity and adverse reactions,and maintain the drug concentration in the bone tuberculosis region for a long time,and to observe the in vitro drug release of the microspheresMETHODS:Double emulsion solvent evaporation method was used to prepare PLGA-cycloserine microspheres that were bonded into sponge implant by Bletilla striata polysaccharide extract.Then,morphology,particle size,encapsulation efficiency and in vitro performance of the microspheres were observed.The drug loading,burst release,appearance and dispersion of the microspheres were observed at 0,1,2 months after the microspheres were placed in room temperature (25 ℃),high temperature (60 ℃) and high humidity (93％),respectively.RESULTS AND CONCLUSION:The PLGA-cycloserine microspheres that were round and spherical presented with the mean particle size of (143±38) μm,the drug loading of 38.38％ and the encapsulation efficiency of 67.54％.No burst release occurred,and the cumulative release of drug within 50 days was 65.62％ After being stored at room temperature,high temperature and high humidity for 1 and 2 months,the microspheres were intact in the appearance and morphology,and showed insignificant changes in drug loading and burst release.To conclude,the time of degradation and the release of drug accord with the biological requirements of bone restoration.
ABSTRACT
5-AZA-2'-deoxycytidine (5-AZA-CdR) is a demethylating, teratogenic agent and a mutagen, which causes defects in the developing mouse and rat after implantation. Our previous data indicated that 5-AZA-CdR (0.2 and 1.0 muM) inhibited the development of mouse preimplantation embryos. Pronuclear embryos exposed to 5-AZA-CdR at the pronuclear stage were unable to form 8-cell embryos, while 2-cell-stage embryos exposed to 5-AZA-CdR only developed into uncompacted 8-cell-stage embryos. And there was no formation of blastocysts when 4-cell embryos cultured in 5-AZA-CdR. In our present study, we detected Dnmt1o protein and some developmental gene expression in order to find the reasons for the developmental arrest. Dnmt1o could not traffic to 8-cell nuclei as control when embryos were exposed to 5-AZA-CdR. Dnmt1o was in cytoplasm at 2-cell and 4-cell stages before and after treated with 5-AZA-CdR. Gene expression changes were also detected in this research. Our data indicated that connexin 31 (Cx31), connexin 43 (Cx43), connexin 45 (Cx45), E-cadherin (Cdh1) and beta-catenin (Ctnnb1) were all downregulated by 5-AZA-CdR. Cx31, Cx43 and Cx45 are members of connexins family, which have a central role in gap junctions. Cdh1 and Ctnnb1 are necessary for the foundation of tight junctions. Therefore, developmental arrest induced by 5-AZA-CdR may be caused by the failure of Dnmt1o cytoplasmic-nuclear traffic and the down-regulation of developmental gene expression. Normal compaction and blastocoel cavitation need Dnmt1o traffic to 8-cell nuclei and the right gene expression, especially the correlative genes in gap junctions and tight junctions.
Subject(s)
Azacitidine/analogs & derivatives , Blastocyst/drug effects , DNA (Cytosine-5-)-Methyltransferases/antagonists & inhibitors , Embryonic Development/drug effects , Mutagens/toxicity , Teratogens/toxicity , Animals , Azacitidine/toxicity , Blastocyst/physiology , Cadherins/antagonists & inhibitors , Cadherins/metabolism , Connexins/antagonists & inhibitors , Connexins/metabolism , DNA (Cytosine-5-)-Methyltransferase 1 , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Methylation , Decitabine , Down-Regulation , Female , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Developmental/physiology , Mice , beta Catenin/antagonists & inhibitors , beta Catenin/metabolismABSTRACT
In the present study, we analyzed the effects of 22 microsatellite DNA loci on behavior responses and plasma concentration of hormones related to stress and metabolism following transport trial in pigs. These subjects were selected from the segregating F2 generation of a Pietrain (PIE) x Erhualian (EHL) cross, and the two swine strains differ in stress tolerance. A so-called Backtest Score (BS) at 3, 10 and 17 days after birth (BS3, BS10 and BS17) was implemented to assess the behavior responses for each piglet. Plasma concentrations of Insulin, ACTH, Cortisol, T3 and T4 in pigs were measured after the 2 hours' transport. One-way ANOVA was applied to analyze the relation between microsatellite polymorphisms and stress tolerance markers including BS and concentration of hormones. The results revealed that the allelic number was 3-8, heterozygosity was 0.4155-0.7432 and polymorphism information content was 0.3651-0.8150. SW1808 (P<0.01) and SW0320 (P<0.05) had significant effect on ACTH. The effect of SW1303 on Insulin, SW1092 on Cortisol, SW0320 on T3, S0101 on T4, and SW2446 on BS3 reached a significant level at P<0.05, respectively. The effects of SW2446 (P<0.01), SW1816 (P<0.05) and SW0092 (P<0.05) on BS10 were significant, and the effects of SW2108, SW1816 and SW1023 on BS17 were also significant (P<0.05). Our study suggested that these 11 microsatellites in swine were closely associated with behavior responses and stress tolerance in response to transport.