OBJECTIVETo develop a HPLC method for the determination of plasma concentration of oridonin (ORI) and study the pharmacokinetics of ORI in mice.

METHODBlood was sampled from mice which were injected ORI by 10 mg x kg(-1) at different time intervals, and the concentration of ORI was determined by HPLC. The pharmacokinetic parameters were accessed by 3P97.

RESULTThe calibration curve was linear (r = 0.998 7) within the range of 0.202-20.0 mg x L(-1) for ORI in plasma. The average recoveries were more than 93%. The within-day and between-day precisions were no more than 9%. After i.v. oridonin in mice, the plasma concentration-time course fitted well to two-compartment model. The pharmacokinetic equation was C = 16.192 5e(-0.554 6t) + 5.475 7e(-0.016 3t). The pharmacokinetic parameters were below: t1/2alpha 1.249 9 min, t1/2beta 42.638 4 min, K21 0.152 3 min(-1), K12 0.359 3 min(-1), K10 0.0592 min(-1), AUC 366.035 0 microg x min x mL(-1), CL 0.0273 L x min(-1) x kg(-1), V(c)0.461 5 L x kg(-1).

CONCLUSIONThe method can be used to determine the concentration and to investigate the pharmacokinetics of ORI in mice. ORI was absorbed and distributed very fast in mice. The effect of ORI was rapid. The elimination was the main process.

Animals ; Chromatography, High Pressure Liquid ; methods ; Diterpenes, Kaurane ; pharmacokinetics ; Female ; Male ; Mice

Objective To assess the capability of monochromatic energy images of Gemstone spectral imaging(GSI) in reducing artifacts caused by metallic implants. Methods Twelve subjects with metallic implants underwent GSI (Discovery CT750 HD, GE Healthcare, Milwaukee ). The metallic orthopedic implants included 3 patients of dentures, 2 patients of cervical spinal vertebraplasty, one clavicle fracture fixation, one lumbar spinal vertehraplasty, 3 patients of artificial femoral head, one iliac fracture fixation and one tibial fracture fixation. GSI was performed by using a single source ultra-fast dual energy X-ray switching (80 kVp and 140 kVp). Following GSI scanning, thin slice images were reconstructed into 1.25 mm slice thickness. The monochromatic energy images were set to the same window width and level (window width 1500 HU,window level 500 HU). The artifact indexes (AI) at different kiloelectronvolts (keV) images were measured and compared. 3D reconstruction was performed using images with minimal AI. Result The artifacts index on monochromatic energy images varied with the change of keV. Of the images from 12 subjects, the maximal AI ranged between 145-225 at 40 keV, and minimal AI ranged between 15-90 at the 95-140 keV. The artifacts are clearly visible on polychromatic energy images and the artifacts are reduced markedly on the monochromatic energy images with minimal AI. Conclusion The artifacts caused by metallic implants can be reduced significantly by GSI with high keV monochromatic energy images.

Objective To measure and investigate the anatomical characteristics of the proximal femur canal curves in patients with developmental dysplasia of the hip (DDH), and to provide references for the design of femoral stem of DDH patients. Methods Three-dimensional reconstructions of the proximal femur were conducted from the CT data, and the anatomical morphology characteristics were obtained from 64 patients with DDH (74 hips, 12 males, 52 females, average age of 45.3 years) and 30 healthy controls (30 hips, 21 males, 9 females, average age of 29.4 years). Multiple anteroposterior diameter and mediolateral diameter around the lesser trochanter at different heights and the fitting curves of different groups were obtained. Results The femoral neck anteversion angle, neck-shaft angle, height of the isthmus, canal flare index (CFI), femoral head diameter and femoral offset of DDH patients and healthy controls were 26.39°±14.74° and 15.68°±7.95°, 125.65°±5.73° and 129.19°±5.80°, (99.14±14.62) mm and (110.13±11.73) mm, 3.63±0.77 and 4.45±0.79, (44.01±5.75) mm and (47.26±3.94) mm, (31.80±3.82) mm and (36.42±4.84) mm, respectively. DDH group had the significantly greater femoral neck anteversion angle, and other anatomical morphology characteristics were significantly smaller than the control group. The obtained anteroposterior diameter, mediolateral diameter and the fitting curves showed that DDH group had narrow medullary cavity and forward shifting anteroposterior diameter. In addition, there was a statistical significance between the Crowe Ⅳ DDH and other types of DDH, and deformation degree of the femur increased with the increase of DDH type. Conclusions The proximal femur of DDH patients was significantly different from the healthy controls. Moreover, there were significantly morphological differences between different types of DDH. The research findings can be used as quantitative references for understanding the morphological feature of DDH patients and the corresponding design of femoral stem for DDH patients.

Objective Aiming at solving the problems of pain on the anteromedial tibia, tibial component loosening and osteoarthritis progression after unicompartmental knee arthroplasty (UKA), the influence of different geometric shapes of tibial component pegs on stress distributions in tibia was analyzed by finite element method. Methods The finite element models with UKA were established and validated. Geometric shapes of tibial component were designed. Under the same loading condition, the tibial components with double-peg, single-keel, double-keel and cross-star were studied for finite element analysis and compared with intact model, so as to evaluate the influence of tibial component with different shapes on stresses of cortical bone in anteromedial tibia, cancellous bone under tibial component and cartilage in contralateral tibia. Results Compared with the intact model, the peak stress of cortical bone in anteromedial tibia with double-peg, single-keel, double-keel and cross-star tibial components increased by 56.1%, 55.9%, 54.5% and 68-4%, respectively. The peak stress of cancellous bone under tibial component with single-keel and double-keels decreased by 8.1% and 15.6% respectively, while the peak stress of cancellous bone under tibial component with double-peg and cross-star increased by 67-9% and 121-5%, which were higher than the fatigue yield stress of cancellous bone. The peak stress of cartilage in contralateral tibia with double-peg, single-keel, double-keel and cross-star tibial components decreased by 42.1%, 26.6%, 24.2% and 28.5%, respectively. ConclusionsThe load distribution of the medial and lateral tibia changed after UKA operation, and a greater load was observed on the replacement side. Single-keel and double-keel tibial components were more effective in reducing stresses on cortical bone in anteromedial tibia and cancellous bone, while the stress distribution in tibia with single-keel tibial component was closer to that of the intact tibia. The research findings can provide theoretical references for designing single-keel tibial component of unicompartmental knee prosthesis which conforms to better mechanical properties of the knee joint.