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。     

Studies on the mechanism of decreased neutrophil adherence to postconfluent cultured endothelial cells

The adherence of neutrophils (PMN) to endothelium is a crucial early step in neutrophil-mediated vascular injury. However, vascular injury is not a necessary event in inflammatory states, which suggests that endogenous mechanisms may protect endothelial cells from neutrophil-mediated injury. Previous studies suggested that leukocytes adhered in greater numbers to vascular endothelium in vivo and in vitro, where the contiguity of the cells was disrupted and where endothelial cells were actively migrating and proliferating. We studied the effect of development of a confluent monolayer on adherence of human PMN to cultured bovine calf aortic endothelial cells and investigated several mechanisms by which this effect might occur. We found that adherence of quiescent and activated PMN decreased with development of a confluent endothelial cell monolayer. A similar effect was found using human umbilical-vein endothelial cells. In contrast, adherence of nylon wool-nonadherent, thymus-derived lymphocytes increased. Variation in neutrophil adherence was not due to adherence of PMN to exposed tissue culture plastic or to exposed matrix components in preconfluent cultures, nor due to products released into culture supernatants. Diminished PMN adherence to postconfluent monolayers may have been related to changes in endothelial cell glycoproteins because neuraminidase or cycloheximide pretreatment augmented PMN adherence to postconfluent cultures more than to preconfluent cultures. However, the extent of total cell surface sialation, as assessed by neuraminidase-releasable [3H]glucosamine from metabolically labeled monolayers, did not differ between pre- and postconfluent cultures, suggesting that some specific sialated cell surface constituent is responsible for decreased PMN adherence to postconfluent monolayers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Combining Free Flap Reconstruction and Craniofacial Prosthetic Technique for Orbit,Scalp, and Temporal Defects

Objectives: To identify factors leading to successful application of prosthetic techniques following free flap reconstruction of the orbit, scalp, and temporal region. Study Design: Retrospective review. Methods: Twenty-eight patients who underwent free flap reconstruction for defects of these regions between 1989 and 1996 were reviewed for clinical parameters, flap loss, patient survival, and implant loss rate. Prosthetic usage rates were compared before and after introduction of a site-specific reconstructive algorithm. Results: Free flap success rate was 93%, whereas osseointegrated implant loss rate was 11%. In addition to implants, a reconstructive strategy that provided thin, vascular tissue between bone and skin, a flat platform in the temporal region, and preservation of orbital cavity depth led to increased prosthetic usage. Conclusions: Craniofacial prosthetic techniques can significantly augment the results of free flap surgery for the orbit, scalp, and temporal region. Successful combination of these techniques requires a site-specific surgical approach.