Simultaneous Determination of Six Compounds in Rat Plasma by Ultra‑Performance Liquid Chromatography with Tandem Mass Spectrometry: Application in the Pharmacokinetic Study of Qing Gan‑Shu Yu‑Fang

A rapid and high selective ultra?performance liquid chromatography (UPLC) with tandem mass spectrometry method for simultaneous determination of six compounds including albiflorin, paeoniflorin, picroside I, picroside II, saikosaponin A, and saikosaponin D in rat plasma was developed and validated using butyl p-hydroxybenzoate as an internal standard. One-step direct protein precipitation with acetonitrile was used to extract the compounds from the rat plasma samples. Chromatographic separation was achieved using an ACQUITY UPLC BEH C18 column (100 mm × 2.1 mm, 1.7 µm) at a flow rate of 0.4 mL/min, using gradient mode containing 0.1% formic acid in water and acetonitrile were used as the Mobile phase A and B. Electrospray ionization in negative ion mode and multiple reaction monitoring were used to identify and quantify active components. Calibration curves showed good linearity (R2 > 0.9908) over a wide concentration range for all compounds. The intra- and interday precision (relative standard deviation) ranged 2.4%–7.0% and 2.6%–8.0%, respectively. The accuracy (relative error) was from ?13.0% to 13.2% at all quality control levels. The recovery ranged from 81.1% to 92.5%. The validated method was successfully applied to pharmacokinetic study in rats after oral administration of Qing Gan?Shu Yu?Fang. The results show that one can draw a conclusion that these six active ingredients can be quickly absorbed and play a pharmacodynamic role rapidly in vivo.     

Inhibition of focal adhesion kinase enhances antitumor response of radiation therapy in pancreatic cancer through CD8+ T cells

Objective:Pancreatic ductal adenocarcinoma(PDAC)is a deadly malignancy,due in large part to its resistance to conventional therapies,including radiotherapy(RT).Despite RT exerting a modest antitumor response,it has also been shown to promote an immunosuppressive tumor microenvironment.Previous studies demonstrated that focal adhesion kinase inhibitors(FAKi)in clinical development inhibit the infiltration of suppressive myeloid cells and T regulatory(T regs)cells,and subsequently enhance effector T cell infiltration.FAK inhibitors in clinical development have not been investigated in combination with RT in preclinical murine models or clinical studies.Thus,we investigated the impact of FAK inhibition on RT,its potential as an RT sensitizer and immunomodulator in a murine model of PDAC.Methods:We used a syngeneic orthotopic murine model to study the effect of FAKi on hypofractionated RT.Results:In this study we showed that IN10018,a small molecular FAKi,enhanced antitumor response to RT.Antitumor activity of the combination of FAKi and RT is T cell dependent.FAKi in combination with RT enhanced CD8+T cell infiltration significantly in comparison to the radiation or FAKi treatment alone(P<0.05).FAKi in combination with radiation inhibited the infiltration of granulocytes but enhanced the infiltration of macrophages and T regs in comparison with the radiation or FAKi treatment alone(P<0.01).Conclusions:These results support the clinical development of FAKi as a radiosensitizer for PDAC and combining FAKi with RT to prime the tumor microenvironment of PDAC for immunotherapy.     

Biomechanical behavior of brain injury caused by sticks using finite element model and Hybrid-III testing

Objective: To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases. Methods: In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks. Results: In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values. Conclusions: The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism.     

LIM kinases in synaptic plasticity and their potential as therapeutic targets

LIM domain kinases(LIMKs),which modulate cytoskeletal dynamics,are found throughout the central nervous system.The synaptic junctions between neurons show structural alteration or plasticity during neurodevelopment,learning and memory formation,or after injury and disease;in some cases completely new connections form,while others are lost.This remodeling is under the control of the actin cytoskeleton and therefore is influenced by the activity of LIMKs(Scott and Olson,2007).Recent reports discussed in this perspective shed light on the potential role of LIMK in hippocampal dendritic spines and photoreceptor presynaptic terminals and illustrate the importance of LIMK in nerve cell function.     

去势比格犬腹部脂肪与相关血清学指标及骨密度的变化关系

目的通过建立去势比格犬模型,观察绝经早期腹部脂肪变化规律,并通过对脂肪与骨代谢相关血清学指标的测量与分析,探讨脂肪及骨代谢的关键影响因素。方法选取6只成年雌性比格犬进行去势术,分别在术前、术后4个月、6个月、10个月进行腰椎定量CT(quantatitive computed tomography,QCT)腹部脂肪面积、骨密度(bone mineral density,BMD)、MRI腰椎骨髓脂肪含量及血清学指标的检测,比较不同时间各指标的变化趋势及关系。结果比格犬腹内脂肪面积(visceral fat area,VFA)、皮下脂肪面积(subcutaneous fat area,SFA)、腹部总脂肪面积(total fat area,TFA)在术后6个月、10个月均增加(P0.05),术后10个月VFA增加百分比均值为84.39%,且为三者中最大;术后比格犬BMD并未明显降低。体重、BMD、瘦素(leptin,LP)、VFA、高密度脂蛋白(high-density lipoprotein,HDL)与SFA相关。SFA、体重、低密度脂蛋白(low-density lipoprotein,LDL)、内脏脂肪素(visfatin,VFN)与BMD相关。结论去势比格犬模型可用于研究绝经后雌激素缺乏所引起的脂肪代谢变化,但短期内BMD并未明显丢失,骨、脂肪代谢之间存在交互作用。