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。     

The influence of diabetes on free flap transfer: I. Flap survival and microvascular healing.

Although recent clinical case presentations suggest that diabetes does not predispose free tissue transfers to increased risk of failure, this remains an open question. The present study used a syngeneic rat strain (Lewis) for free groin flap transplantations between normal rats and streptozotocin-induced diabetic rats (2 months' duration of symptoms), to investigate the influence of diabetes on flap transfer. Flap survival at 1 week, vascular patency, flap histology and ultrastructure, and scanning electron microscopy of anastomotic sites and of corrosion casts of flap vasculature were used as bases for comparison. No differences were found in comparisons of flap survival between any groups of transfer combinations (normal flap onto normal recipient, diabetic flap onto normal recipient, normal flap onto diabetic recipient, and diabetic flap onto diabetic recipient); 100% success was achieved in each group. No differences were found in histology or corrosion casts. Transmission electron microscopy revealed a thickening of the capillary basement membrane in rat diabetic skin after only 8 weeks of symptoms. This ultrastructural finding is consistent with similar capillary basement membrane thickening seen in many other tissues of short- and long-term diabetic animals and humans. Re-endothelialization across the arterial anastomosis at 2 weeks postoperatively was significantly faster in normal versus diabetic animals (p less than 0.05). The predominantly negative findings of this study support the application of free flap transfers in diabetic patients. It is concluded that reconstructive efforts involving free tissue transfer may not be contraindicated in diabetic patients.     

Muscle mass effect on arterial desaturation after maximal exercise.

We measured arterial oxygen saturation before and immediately after randomly allocated 6 min of "all-out" maximal arm cranking, treadmill running, and ergometer rowing in 10 men and women with a median maximal oxygen uptake of 4.47 (range 3.22-5.34) 1.min-1. Arterial saturation for oxygen was unaltered after arm cranking, but decreased 1.7 (-2.5-6.0) % (P less than 0.05) after running, and 2.2 (1.0-8.7) % (P less than 0.01) after rowing. Arterial saturation was inversely related to capillary blood lactate, which reached 11.8 (7.4-14.0), 12.6 (8.9-18 2), and 14.3 (12.0-19.3) mmol.l-1 (P less than 0.01), respectively, and arterial bicarbonate fell to 15.0 (13.0-23.6), 12.4 (7.2-20.4), and 10.8 (0.0-12.5) mmol.l-1 (P less than 0.01). Thus, pH decreased to 7.25 (7.22-7.40), 7.17 (6.95-7.35), and 7.09 (6.84-7.19) (P less than 0.01). When measured immediately post-exercise, arterial oxygen tension was unchanged or elevated from rest, eliminating the possibility that the arterial desaturation was caused by a pulmonary diffusion limitation. The results of this investigation show that arterial desaturation associated with maximal exercise takes place in proportion to the involved muscle mass, as do deviations in blood lactate, bicarbonate, and hydrogen concentrations.