BACKGROUND:Intervertebral disc degeneration is an important cause of low back pain.At present,there are many modeling methods for disc degeneration in China and abroad,but there is not a model for low back pain due to disc degeneration. OBJECTIVE:To compare the effect of mechanical puncture combined with tumor necrosis factor α and complete Freund's adjuvant with a conventional disc mechanical puncture alone. METHODS:A total of 18 male adult Sprague-Dawley rats were randomly divided into 3 groups,with 6 animals in each group.No treatment was given in the blank group.Animal models of intervertebral disc degeneration were made in the L4-5 segments of rats in the control using conventional mechanical puncture.In the experimental group,on the basis of mechanical puncture,tumor necrosis factor α+complete Freund's adjuvant was injected into the L4-5 intervertebral discs using a microinjector to establish a model of disc degeneration induced by mechanical puncture combined with inflammatory factors.Four weeks after surgery,the pain threshold of rats was measured by the hot plate method for assessing the perception of heat injury in rats with intervertebral disc degeneration.MRI examination was performed to observe the disc degeneration in each group.ELISA was used to detect the levels of serum tumor necrosis factor α,interleukin 1β,interleukin 6 and prostaglandin E2.Hematoxylin-eosin and Safranin O-fast green staining were used to observe the morphological changes of the disc. RESULTS AND CONCLUSION:In terms of pain,the behavioral pain threshold of the experimental group was continuously decreased,and the levels of serum inflammatory factors were significantly higher compared with the control group.In terms of morphology,the MRI results showed that the L4-5 nucleus pulposus signal completely disappeared in the experimental group.Histopathological results showed that in the control group,the nucleus pulposus was intact,more notochord cells were visible,and some fiber rings were ruptured,while in the experimental group,there are fewer notochord cells and the structure of the nucleus pulposus and fibrous ring is disturbed,with the boundary disappearing.To conclude,mechanical puncture combined with tumor necrosis factor alpha and complete Freund's adjuvant can successfully establish a discogenic low back pain model in rats.This operation is simple and economical to achieve obvious disc degeneration and low back pain,with greatly shortened molding cycle.This model can be used as a reference for studying discogenic low back pain models.

Objective:To investigate the prognostic value and related factors of heart-type fatty acid binding protein (H-FABP) in patients with heart failure.Methods:A total of 877 consecutive patients who were admitted to heart failure care unit of Fuwai hospital and diagnosed as heart failure from July 2015 to July 2017 were enrolled in this study. Baseline serum H-FABP concentration was measured by fluorescence lateral flow immunoassay. According to serum H-FABP levels, patients were divided into three groups: low H-FABP group (H-FABP≤4.04 ng/ml, n=292), middle H-FABP group (H-FABP 4.04-7.02 ng/ml, n=292) and high H-FABP group (H-FABP≥7.02 ng/ml, n=293). The general clinical characteristics were collected and compared among the three groups. According to whether heart failure was caused by coronary artery disease or not, patients with heart failure were divided into ischemic heart failure and non-ischemic heart failure. Multivariate linear regression analysis was performed to explore the independent risk factors of H-FABP. The primary endpoint events were the composite of all-cause death or heart transplantation. Multivariate Cox regression analyses, receiver operating characteristic (ROC) curves, risk prediction tests with multivariate Cox regression model and Kaplan-Meier analyses were conducted to investigate the relationship between H-FABP and the prognosis of heart failure. Results:Multivariate linear regression analysis showed that age, coronary artery disease, alanine aminotransferase, uric acid and N-terminal pro-B type natriuretic peptide (NT-proBNP) were positively associated with H-FABP (β=0.012, 0.238, 0.001, 0.345 and 0.063 respectively,all P<0.05), while female, hemoglobin, albumin, sodium, and estimated glomerular filtration rate (eGFR) were negatively associated with H-FABP (β=-0.184, -0.006, -0.016, -0.034 and -0.006 respectively, all P<0.05). One hundred and nineteen patients (13.6%) lost to follow-up, and 246 patients (32.5%) suffered from all-cause death or heart transplantation during the median follow-up duration of 931 (412-1 185) days. Multivariate Cox regression analysis showed that baseline H-FABP (log 2H-FABP) level was the independent predictor of all-cause death or heart transplantation in patients with heart failure ( HR=1.39, P<0.001). ROC curves showed that baseline H-FABP was a predictor of all-cause death or heart transplantation in patients with heart failure within 3 months, 1 year and 2 years (areas under the curves were 0.69, 0.69 and 0.71 respectively), and the best cut-off values were 5.85 ng/ml, 6.54 ng/ml and 6.54 ng/ml respectively. Risk prediction test with multivariate Cox regression model showed that baseline H-FABP could provide additional prognostic value in predicting all-cause death or heart transplantation for patients with heart failure on top of basic model and baseline NT-proBNP ( P<0.001). Taking 6.54 ng/ml and trisected levels of H-FABP as cut-off values respectively, Kaplan-Meier analyses showed that the survival rates were significantly different among the two or three groups ( P<0.001). Subgroup analyses showed that baseline H-FABP (log 2H-FABP) level was an independent predictor of all-cause death or heart transplantation in patients with ischemic heart failure ( HR=1.74, P<0.001), as well as in patients with non-ischemic heart failure ( HR=1.28, P=0.027). Conclusions:Age, sex, coronary artery disease, hemoglobin, albumin, alanine aminotransferase, sodium, eGFR, uric acid and NT-proBNP are associated with H-FABP level. Baseline H-FABP level is an independent predictor of all-cause death or heart transplantation in patients with heart failure. On top of basic model and baseline NT-proBNP, baseline H-FABP could provide additional prognostic value in predicting adverse events for patients with heart failure.