Introduction: To analyze the perioperative hidden blood loss (HBL) and its influencing factors in elderly cervical spondylosis patients treated with anterior cervical discectomy fusion (ACDF). Materials and Methods: From January 2017 to December 2018, 128 elderly cervical spondylosis patients (age > 65 y) treated with ACDF were selected. The patients’ height, weight, duration of symptoms, previous medical history and other basic information were routinely recorded. The hemoglobin (Hb), hematocrit (Hct) and blood coagulation function preoperative and the next day postoperative were recorded. The operation time, surgical bleeding, ASA classification, fixation method, total drainage and the time for extraction of drainage tube were recorded. The total blood loss (TBL) was calculated according to the Gross’s formula, and HBL was calculated based on TBL, total drainage and surgical bleeding. The statistical analysis of HBL was performed, and then influential factors were further analyzed by multivariate linear regression analysis and t test. Results: The mean surgical bleeding was 102.70 ± 46.78 mL and HBL was 487.98 ± 255.96 mL. HBL accounted for 67.61 ± 5.20% of TBL. According to the multiple linear regression analysis, the gender (P = 0.047), operation time (P = 0.000), fixation method (P = 0.014) and international normalized ratio (INR) (P = 0.003) influenced the amount of HBL. Body mass index (BMI) (P = 0.624), hypertension (P = 0.977), diabetes (P = 0.528), blood type (P = 0.577), ASA classification (P = 0.711), duration of symptoms (P = 0.661), preoperative cobb angle (P = 0.152), number of surgical level (P = 0.709), intramedullary hyperintensity (P = 0.967), drainage time (P = 0.294), postoperative drainage volume (P = 0.599), prothrombin time (PT) (P = 0.674), activated partial thromboplastin time (APTT) (P = 0.544) and thrombin time (TT) (P = 0.680) had no correlation with the amount of HBL. Conclusions: There was obvious HBL during the perioperative period of ACDF in elderly cervical spondylosis patients. The male patients, longer operation time, fusion with titanium plate and cage and high INR were independent risk factors for HBL.

BACKGROUND In degenerative intervertebral disc (IVD), an unfavorable IVD environment leads to increased senescence of nucleus pulposus (NP)-derived mesenchymal stem cells (NPMSCs) and the inability to complete the differentiation from NPMSCs to NP cells, leading to further aggravation of IVD degeneration (IDD). Urolithin A (UA) has been proven to have obvious effects in delaying cell senescence and resisting oxidative stress. AIM To explore whether UA can alleviate NPMSCs senescence and to elucidate the underlying mechanism. METHODS In vitro , we harvested NPMSCs from rat tails, and divided NPMSCs into four groups: the control group, H 2 O 2 group, H 2 O 2 + UA group, and H 2 O 2 + UA + SR-18292 group. Senescence-associated β-Galactosidase (SA-β-Gal) activity, cell cycle, cell proliferation ability, and the expression of senescence-related and silent information regulator of transcription 1/PPAR gamma coactivator-1α (SIRT1/ PGC-1α) pathway-related proteins and mRNA were used to evaluate the protective effects of UA. In vivo , an animal model of IDD was constructed, and X-rays, magnetic resonance imaging, and histological analysis were used to assess whether UA could alleviate IDD in vivo . RESULTS We found that H 2 O 2 can cause NPMSCs senescence changes, such as cell cycle arrest, reduced cell proliferation ability, increased SA-β-Gal activity, and increased expression of senescence-related proteins and mRNA. After UA pretreatment, the abovementioned senescence indicators were significantly alleviated. To further demonstrate the mechanism of UA, we evaluated the mitochondrial membrane potential and the SIRT1/PGC-1α pathway that regulates mitochondrial function. UA protected mitochondrial function and delayed NPMSCs senescence by activating the SIRT1/PGC-1α pathway. In vivo , we found that UA treatment alleviated an animal model of IDD by assessing the disc height index, Pfirrmann grade and the histological score. CONCLUSION In summary, UA could activate the SIRT1/PGC-1α signaling pathway to protect mitochondrial function and alleviate cell senescence and IDD in vivo and vitro .

Osteosarcoma, the most common malignant tumor of the bone, seriously influences people’s lives and increases their economic burden. Conventional chemotherapy drugs achieve limited therapeutic effects owing to poor targeting and severe systemic toxicity. Nanocarrier-based drug delivery systems can significantly enhance the utilization efficiency of chemotherapeutic drugs through targeting ligand modifications and reduce the occurrence of systemic adverse effects. A variety of ligand-modified nano-drug delivery systems have been developed for different targeting schemes. Here we review the biological characteristics and the main challenges of current drug therapy of OS, and further elaborate on different targeting schemes and ligand selection for nano-drug delivery systems of osteosarcoma, which may provide new horizons for the development of advanced targeted drug delivery systems in the future.