Physiologically based pharmacokinetic modeling of apixaban to predict exposure in populations with hepatic and renal impairment and elderly populations.

BACKGROUND: Apixaban is a factor Xa inhibitor with a limited therapeutic index that belongs to the family of oral direct anticoagulants. The pharmacokinetic (PK) behavior of apixaban may be altered in elderly populations and populations with renal or hepatic impairment, necessitating dosage adjustments. METHODS: This study was conducted to examine how the physiologically based pharmacokinetic (PBPK) model describes the PKs of apixaban in adult and elderly populations and to determine the PKs of apixaban in elderly populations with renal and hepatic impairment. After PBPK models were constructed using the reported physicochemical properties of apixaban and clinical data, they were validated using data from clinical studies involving various dose ranges. Comparing predicted and observed blood concentration data and PK parameters was utilized to evaluate the model's fit performance. RESULTS: Doses should be reduced to approximately 70% of the healthy adult population for the healthy elderly population to achieve the same PK exposure; approximately 88%, 71%, and 89% of that for the elderly populations with mild, moderate, and severe renal impairment, respectively; and approximately 96%, 81%, and 58% of that for the Child Pugh-A, Child Pugh-B, and Child Pugh-C hepatic impairment elderly populations, respectively to achieve the same PK exposure. CONCLUSION: The findings indicate that the renal and hepatic function might be considered for apixaban therapy in Chinese elderly patients and the PBPK model can be used to optimize dosage regimens for specific populations.

Evaluation of the cargo contents and potential role of extracellular vesicles in osteoporosis.

Osteoporosis is a common aging-related disease diagnosed primarily using bone mineral density (BMD). Extracellular vesicles (EVs) remain unexplored in the context of osteoporosis. Towards this, EVs were isolated from plasma of a discovery cohort with 8 non-osteoporotic and 8 osteoporotic individuals, and nanoparticle tracking analysis (NTA) revealed a significantly higher EV concentration in osteoporotic individuals (P = 0.003). Moreover, EVs concentration showed a linear correlation with bone mineral density (BMD) values (linear correlation coefficient r = 0.9542, deviation from zero, p < 0.001). Results using a mouse model of osteoporosis confirmed that the number of EVs in mice from hindlimb unloading group was significantly higher than that from the age-matched control group (p = 0.015). TaqMan Real-Time PCR demonstrated that miR-335-5p, -320a, -483-5p, and miR-21-5p, were significantly higher expressed in osteoporotic patients compared with non-osteoporotic individuals. Quantitative real-time PCR shown that Wnt1, Wnt5a, Wnt7a, and Wnt9a mRNAs were lower expressed in osteoporosis derived EVs. In vitro functional assay indicated that osteoporosis derived EVs resulted in reduced mineralization in SaOS-2 cells. In conclusion, these results suggest that osteoporosis increased the secretion of EVs which carry higher expression of miRNAs and decreased expression of Wnt signals, further decreased the mineralization capacity in human osteoblasts.

Lycium barbarum polysaccharides exert an antioxidative effect on rat chondrocytes by activating the nuclear factor (erythroid-derived 2)-like 2 signaling pathway.

INTRODUCTION: Oxidative stress is the main cause of osteoarthritis (OA). Lycium barbarum polysaccharides (LBP) have antioxidant properties. Thus, the potential effect of LBP on H2O2-stimulated chondrocytes was examined. MATERIAL AND METHODS: The cell viability was detected by CCK-8. The reactive oxygen species (ROS) production and apoptosis rates were determined by flow cytometric analysis. The DNA damage was detected by comet assay. Real-time polymerase chain reaction (qPCR) and Western blot assays were performed to examine the expression of histone 2A family member X (γH2AX), checkpoint kinase 1 (Chk1), poly ADP-ribose polymerase (PARP), cysteinyl aspartate specific proteinase (caspase)-3/8/9, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and its antioxidant-response element (ARE) dependent factors including heme oxygenase-1 (HO-1) and quinine oxidoreductase-1 (NQO-1). RESULTS: Compared to the H2O2 group, LBP inhibited the ROS production and DNA damage caused by H2O2 (p < 0.05), respectively. LBP inhibited the mRNA and protein expressions of γH2AX and Chk1 (p < 0.05). Meanwhile, LBP significantly decreased apoptosis (p < 0.05). And LBP inhibited the expression levels of PARP and Caspase-3/8/9 (p < 0.05). Moreover, LBP increased the expression of Nrf2, HO-1and NQO-1 (p < 0.05). Furthermore, the depletion of Nrf2 that mediated by RNA interference reversed the apoptosis and DNA damage inhibition effect of LBP (p < 0.05). CONCLUSIONS: LBP protected chondrocytes through inhibiting DNA damage and apoptosis caused by H2O2, in which the Nrf2/ARE signaling pathway played a positive role. It provided an inspiration for clinical application - developing LBP as a therapeutic agent and Nrf2 as a promising candidate.

Exosomes containing differential expression of microRNA and mRNA in osteosarcoma that can predict response to chemotherapy.

A major challenge in osteosarcoma (OS) is the selection of the most effective chemotherapeutic agents for individual patients, while the administration of ineffective chemotherapy increases mortality and decreases quality of life in patients. This emphasizes the need to evaluate every patient's probability of responding to each chemotherapeutic agent. We developed a profiling strategy for serum exosomal microRNAs and mRNAs in OS patients with differential chemotherapeutic responses. Twelve miRNAs were up regulated and 18 miRNAs were under regulated significantly in OS patient with poor chemotherapeutic response when compared with those in good chemotherapeutic response (p<0.05). In addition, miR-124, miR133a, miR-199a-3p, and miR-385 were validated and significantly reduced in poorly responded patients with an independent OS cohort. While miR-135b, miR-148a, miR-27a, and miR-9 were significantly over expressed in serum exosomes. Bioinformatic analysis by DIANA-mirPath demonstrated that Proteoglycans in cancer, Hippo signaling pathway, Pathways in cancer, Transcriptional misregulation in cancer, PI3K-Akt signaling pathway, Ras signaling pathway, Ubiquitin mediated proteolysis, Choline metabolism in cancer were the most prominent pathways enriched in quantiles with the miRNA patterns related to poor chemotherapeutic response. Messenger RNAs(mRNAs) includingAnnexin2, Smad2, Methylthioadenosine phosphorylase (MTAP), Cdc42-interacting protein 4 (CIP4), Pigment Epithelium-Derived Factor (PEDF), WW domain-containing oxidoreductase (WWOX), Cell division cycle 5-like (Cdc5L), P27 were differentially expressed in exosomes in OS patients with different chemotherapeutic response. These data demonstrated that exosomal RNA molecules are reliable biomarkers in classifying osteosarcoma with different chemotherapy sensitivity.

Multiple large xanthomas: A case report.

A 23-year-old male patient presented with multiple large masses in his elbows, buttocks, knees, Achilles tendons, feet, shoulders and hands. The large masses in the elbows and buttocks measured ~6×5×5 cm and ~7×5×4 cm, respectively. The patient presented with an elevated level of low-density lipoprotein cholesterol, and had been previously diagnosed with homozygous familial hypercholesterolemia (FH) and multiple xanthomas. Local surgical excisions were performed to remove the massive xanthomas from the elbows and buttocks, and histological analysis of the surgical specimens confirmed the previous diagnosis of homozygous FH (HoFH). The aim of the present study was to report a rare case of HoFH coinciding with multiple, large and widely-distributed xanthomas and to discuss the clinical characteristics, in order to provide a better understanding of xanthomas and FH.

Intertrochanteric hip fracture surgery in Chinese: risk factors for predicting mortality.

Surgery is the preferred treatment for intertrochanteric fractures. This study aimed to analyze risk factors for predicting mortality after intertrochanteric hip fracture surgery by arthroplasty and internal fixation. We performed a retrospective analysis of 1,263 patients who received surgical treatment for intertrochanteric fractures from January 2005 to December 2010. The clinical and follow-up data from 491 eligible patients were collected and analyzed. The age, activity before surgery, activity after surgery, anesthesia, medical illness, and the time between fracture and surgery were significantly associated with the mortality as single factor. Multifactor analysis showed that the activity after surgery, medical illness, and the time between fracture and surgery were correlated with postoperative mortality. In conclusion, these data suggest that the age, activity after surgery, medical illness could affect postoperative mortality of patients of intertrochanteric fractures. These factors may be used to predict the postoperative mortality of intertrochanteric fractures.