青蒿琥酯皮肤擦剂在小鼠和兔体内的药代动力学研究

将青蒿琥酯溶于苯二甲酸二甲酯,加适量氨酮制成皮肤擦剂。给兔脱毛后,皮肤涂抹此擦剂25mg/kg后,血药浓度达峰时间平均为2 h,峰浓度平均为1.80μg/ml。药物在兔体内平均驻留时间为3.54 h,清除半衰期约为2.46 h。给小鼠脱毛皮肤涂抹擦剂6.7,31.3和71.4 mg/kg,血药浓度在给药后0.5～4 h达高峰,峰浓度分别为0.82,2.05和7.11μg/ml,体内药物平均驻留时间为3.39,2.79及3.54 h,清除半衰期为2.35,1.93及2.45 h。可见,给兔及小鼠皮肤擦剂后,青蒿琥酯吸收良好,血药浓度维持时间较长。     

Microencapsulated pancreatic islets: a pathologic study.

Dog pancreatic islets isolated by an enzymatic digestion method were encapsulated in an alginate-poly L-lysine-alginate membrane. These microencapsulated pancreatic islets were cultured in vitro to study their ability of insulin secretion. Portions of these in vitro-cultured microencapsulated pancreatic islets were taken out for a viability dye exclusion study as well as for pathologic studies to correlate them with insulin secretion ability. We found that there was a strong correlation between them. Good insulin-secreting microcapsules showed well-preserved cell membranes and beta-cell granules. An in vitro culture for one to two days in RPMI-1640 made the islets more stable, the cellular surface became smoother and the beta-granules were in better shape. The microencapsulated pancreatic islets were also injected into the peritoneum of streptozotocin-induced diabetic CDF1 mice. Blood glucose levels dropped and stayed low for up to 60 days. But, when non-encapsulated dog pancreatic islets were used, the blood glucose levels remained low for only about 14 days. A small portion of the injected microcapsules were washed out at specific times for pathologic study. Up to 28 days after injection, only a few of the injected microcapsules showed pericapsular cellular infiltrate. However, after 56 days, most of the microcapsules showed dense pericapsular cellular infiltrate. Immunohistochemical analysis of these infiltrates showed that the majority of cells were fibroblasts and macrophages. Most of the cells located in the inner portion of the infiltrate were fibroblasts, while the macrophages were located mainly on the outer portion. Both scanning and transmission electron microscopy showed that the surface of the microcapsule outer wall was much smoother than the inner wall. The size of the microcapsules was approximately 0.6-0.8 mm and the thickness of the wall measured around 10 nm. The smaller the microcapsule is, the less chance there is of rupture with release of the xenographic islets. Once the wall of the transplanted microcapsules was ruptured, the inner surface showed more increased inflammatory cell and fibroblast infiltration than the outer surface.     

Rapid determination of zygosity and common aneuploidies from amniotic fluid cells using quantitative fluorescent polymerase chain reaction following genetic amniocentesis in multiple pregnancies

Following second-trimester twin amniocentesis, we used quantitative fluorescent polymerase chain reaction (QF-PCR) assays and polymorphic small tandem repeats (STR) for rapid determination of zygosity and common aneuploidies from amniotic fluid (AF) cells in four pregnancies with like-sex twins, fused placentae and inconclusive chorionicity. The first and the second cases were suspected to have inadvertent sampling of the same amniotic cavity twice. The first case showed a dizygotic (DZ) pattern and repeat amniocentesis was thus avoided. The second case was monozygotic (MZ) and was complicated by discordant fetal growth and twin-twin transfusion syndrome. The third case was associated with a co-twin malformation, occipital encephalocele. DNA studies revealed MZ twinning with a discordant structural defect. The fourth case was associated with co-twin abnormalities of cystic hygroma and hydrops fetalis. DNA studies showed DZ twinning with discordant structural and chromosomal defects. The QF-PCR assay with STR has the advantages of rapid determination of zygosity and common aneuploidies in AF cells. This simple test appears to be useful in the instances of possible inadvertent puncture of the same amniotic cavity twice during amniocentesis and of discordant fetal structural and/or chromosomal abnormalities following genetic amniocentesis in multiple pregnancies with uncertain chorionicity.