Determination of lycopene in tissues and plasma of rats by normal-phase high-performance liquid chromatography with photometric detection.

An analytical method for the determination of lycopene in tissues and plasma of rats is described. The method was validated for the determination of lycopene in liver and plasma with respect to selectivity, linearity, accuracy, recovery and precision. Following precipitation of proteins with water-ethanol plasma was extracted with hexane; tissues were extracted with acetone followed by precipitation of proteins with water-ethanol and extraction of lycopene with hexane. Separation and quantification of geometrical isomers of lycopene was achieved by normal-phase HPLC with UV/VIS detection at 471 nm. The method proved to be selective and specific for lycopene in plasma and liver. Detector response was linear in the range from 2 ng/g to 10 microg/g liver and 0.5 ng/ml to 2 microg/ml plasma, respectively. Average recoveries ranged from 96 to 101% in spiked liver samples and from 91 to 94% in spiked plasma samples. Intra-day variability (C.V.) was < or = 6% and < or = 5% in liver and plasma, respectively. Inter-day precision was < or = 9% for liver samples and < or = 6% for plasma samples. The procedures were successfully applied to the sample analysis of pharmacokinetic and metabolism studies.

The Mitchell bunionectomy: a prospective study of 60 consecutive cases utilizing single K-wire fixation.

The authors prospectively evaluated 45 patients (60 feet) affected by hallux valgus and treated with a distal metatarsal osteotomy. The surgical procedure consisted of a modified Mitchell osteotomy, in which fixation was achieved with a Kirschner wire that was driven into the proximal osteotomy fragment and buttressed the distal one. Early weightbearing was allowed without a cast. Follow-up averaged 25 months. The mean American Orthopedic Foot and Ankle Society clinical hallux score increased from 44.6/100 preoperatively to 83.2/100. Radiographic evaluation showed that mean metatarsophalangeal and intermetatarsal angles decreased respectively from 31.7 degrees to 16.9 degrees, and from 15.4 degrees to 8.6 degrees. Short-term loss of correction occurred in three cases (4%). Six feet (10%) had unrelieved metatarsalgia that was related to excessive shortening of the first metatarsal and/or inappropriate orientation of the metatarsal head. Stabilization of the Mitchell osteotomy with a Kirschner wire proved safe and effective for the surgical correction of mild to moderate hallux valgus.