应用威布尔分布函数研究红霉素微囊的溶出度

本文测定了红霉素微囊在人工肠液中的溶出度，并用威布尔分布函数求出了溶出百分率与时间的关系。     

诺氟沙星微囊包囊率及收率的测定

采用6种不同溶剂-非溶剂制备诺氟沙星微囊,并测定包囊率和收率.结果表明,选用二氯甲烷-正已烷制备诺氟沙星微囊其包囊率在6种溶剂-非溶剂组成中最高,达90.90%,收率也较高为87.27%.     

胸腺肽乙基纤维素微囊的制备和体外释药研究

 目的为提高胸腺肽的生物利用度，增强疗效，制备了胸腺肽乙基纤维素缓释微囊。方法用液中干燥法制备胸腺肽乙基纤维素微囊，正交设计法筛选其最佳制备工艺，Lowry法测定药物的含量，计算微囊的载药量、包封率及体外释药量。结果微囊粒径范围为30-80ym，平均粒径为52.64 tim，平均含药量为20.420h，平均包封率为81.64%，其体外释药符合Higuchi方程Q=5.15387+35. 350 59t1/2(r=0.997,n=9)，f1／2-80min，稳定性考察实验结果表明其稳定性较好。结论本法制备的胸腺肽乙基纤维素微囊粒径分布集中，体外释药有明显的缓释作用，具有良好应用前景。     

LS8 cell apoptosis induced by NaF through p-ERK and p-JNK – a mechanism study of dental fluorosis

Objective: To investigate the possible biological mechanism of dental fluorosis at a molecular level.

Material and methods: Cultured LS8 were incubated with serum-free medium containing selected concentrations of NaF (0?～?2?mM) for either 24 or 48?h. Subcellular microanatomy was characterized using TEM; meanwhile, selected biomolecules were analysed using various biochemistry techniques. Transient transfection was used to modulate a molecular pathway for apoptosis.

Results: Apoptosis of LS8 was induced by NaF treatment that showed both time and concentration dependency. The activity of caspase-3, -8, -9 was found to be increased with NaF in a dose-dependent manner. Western blot revealed that the protein expression of p-ERK and p-JNK were decreased, while the expression of p-P38 was increased. Inhibition of the p-ERK and p-JNK pathways resulted in a similar decrease for caspase-3.

Conclusion: During NaF-induced apoptosis of LS8, p-ERK and p-JNK were closely associated with induction of apoptosis, which might be a mechanism of dental fluorosis.     

Determination of the shell permeability of microcapsules with a core of oil-based active ingredient

An experimental and theoretical methodology is proposed to calculate the permeability of microcapsules that contain a core of oil-based active ingredient. Theoretical analysis is performed considering the polydispersity of the measurable capsule size, which allows the estimation of the permeability polydispersity via three different methods. The models proposed were applied in order to determine the permeability of melamine-formaldehyde microcapsules with hexyl salicylate as core oil. Release experiments were performed with four different co-solvents (ethanol, propan-1-ol, propan-2-ol and 1,3-butanediol) of different concentration. Permeability values were found to be constant, despite a two order magnitude of difference in the solubility concentrations.     

Plasmodium falciparum synthetic LbL microparticle vaccine elicits protective neutralizing antibody and parasite-specific cellular immune responses

Epitopes of the circumsporozoite (CS) protein of Plasmodium falciparum, the most pathogenic species of the malaria parasite, have been shown to elicit protective immunity in experimental animals and human volunteers. The mechanisms of immunity include parasite-neutralizing antibodies that can inhibit parasite motility in the skin at the site of infection and in the bloodstream during transit to the hepatocyte host cell and also block interaction with host cell receptors on hepatocytes. In addition, specific CD4+ and CD8+ cellular mechanisms target the intracellular hepatic forms, thus preventing release of erythrocytic stage parasites from the infected hepatocyte and the ensuing blood stage cycle responsible for clinical disease. An innovative method for producing particle vaccines, layer-by-layer (LbL) fabrication of polypeptide films on solid CaCO₃ cores, was used to produce synthetic malaria vaccines containing a tri-epitope CS peptide T1BT* comprising the antibody epitope of the CS repeat region (B) and two T-cell epitopes, the highly conserved T1 epitope and the universal epitope T*. Mice immunized with microparticles loaded with T1BT* peptide developed parasite-neutralizing antibodies and malaria-specific T-cell responses including cytotoxic effector T-cells. Protection from liver stage infection following challenge with live sporozoites from infected mosquitoes correlated with neutralizing antibody levels. Although some immunized mice with low or undetectable neutralizing antibodies were also protected, depletion of T-cells prior to challenge resulted in the majority of mice remaining resistant to challenge. In addition, mice immunized with microparticles bearing only T-cell epitopes were not protected, demonstrating that cellular immunity alone was not sufficient for protective immunity. Although the microparticles without adjuvant were immunogenic and protective, a simple modification with the lipopeptide TLR2 agonist Pam₃Cys increased the potency and efficacy of the LbL vaccine candidate. This study demonstrates the potential of LbL particles as promising malaria vaccine candidates using the T1BT* epitopes from the P. falciparum CS protein.     

口服不同剂量的碘化油微囊防治地方性甲状腺肿的疗效及有效期观察

本文报告1990～1991年在缺碘性疾病流行区新疆托克逊县观察了一次性口服不同剂量(400、300和200mg)碘化油微囊的防治疗效及尿碘排泄。结果表明,在服药后半年和1年甲状腺肿患病率在不同剂量组均有不同程度的下降,治愈率均有不同程度的提高,但与对照组比较无论患病率还是治愈率均无显著差异(P>0.05)。不同剂量组之间服药后1月内尿碘排泄有随剂量增大相应增高的趋势(P<0.01),但至第三个月时无论是不同剂量组之间还是与对照组之间均未见显著差异(P>0.05)。从而提示,口服碘化油微囊能否作为防治缺碘性疾病的长效补碘方法,很值得商榷。     

选择性激光熔化技术在口腔医学中的应用

选择性激光熔化（Selective laser melting,SLM）技术是一种快速成型技术,它以其制作方便、快捷、产品组织结构密度高、精度高、避免传统加工方式原材料浪费等优点,被逐渐运用于各个行业。然而,在口腔医学中的应用还报道较少,主要集中在冠桥修复、可摘局部义齿支架、骨替代物及生物植片等方面。本文介绍了SLM技术的原理,分类以及在口腔医学中的应用特点和前景。