Basing on the machine learning model to analyse the coronary calcification score and the coronary flow reserve score to evaluate the degree of coronary artery stenosis.

AIM: To obtain the coronary artery calcium score (CACS) for each branch in coronary artery computed tomography angiography (CCTA) examination combined with the flow fraction reserve (FFR) of each branch in the coronary artery detected by CT and apply a machine learning model (ML) to analyse and predict the severity of coronary artery stenosis. METHODS: All patients who underwent coronary computed tomography angiography (CCTA) from January 2019 to April 2022 in the HOSPITAL (T.C.M) AFFILIATED TO SOUTHWEST MEDICAL UNIVERSITY) were retrospectively screened, and their sex, age, characteristics of lipid-containing lesions, coronary calcium score (CACS) and CT-FFR values were collected. Five machine learning models, random forest (RF), k-nearest neighbour algorithm (KNN), kernel logistic regression, support vector machine (SVM) and radial basis function neural network (RBFNN), were used as predictive models to evaluate the severity of coronary stenosis. RESULTS: Among the five machine learning models, the SVM model achieved the best prediction performance, and the prediction accuracy of mild stenosis was up to 90%. Second, age and male sex were important influencing factors of increasing CACS and decreasing CT-FFR. Moreover, the critical CACS value of myocardial ischemia >200.70 was calculated. CONCLUSION: Through computer machine learning model analysis, we prove the importance of CACS and FFR in predicting coronary stenosis, especially the prominent vector machine model, which promotes the application of artificial intelligence computer learning methods in the field of medical analysis.

[Analgesic effect and mechanism of electroacupuncture on SNI rats based on microglia-BDNF-neuron signal].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Huantiao" (GB 30) and "Weizhong" (BL 40) on the activation of glial cells, the expression of brain-derived neurotrophic factor (BDNF), excitability and the number of dendritic spines of neurons in the spinal dorsal horn in rats with spared nerve injury (SNI) of sciatic nerve, and to explore the analgesic mechanism of EA on SNI. METHODS: PartⅠ: Sixty SD rats were randomly divided into a sham operation group, a model group, an EA group and a sham EA group, 15 rats in each group. Except the sham operation group, the SNI rat model was established in the remaining groups. The rats in the sham operation group were only treated with incision without damaging the nerve. The rats in the EA group were treated with EA at "Huantiao" (GB 30) and "Weizhong" (BL 40) on the affected side, continuous wave, frequency of 2 Hz, current intensity of 1 mA, 30 minutes each time, once a day, for 14 days. The rats in the sham EA group were treated with EA at points 0.5 cm next to "Huantiao" (GB 30) and "Weizhong" (BL 40) on the affected side; the manipulation, EA parameters and treatment course were the same as the EA group. The latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex were detected 1 day before modeling and 3, 7 and 14 days after modeling. Fourteen days after modeling, Western blot was used to detect the protein expressions of ionized binding adapter junction protein 1 (Iba-1), glial fibrillary acidic protein (GFAP), BDNF and c-Fos in the spinal dorsal horn; the expressions of Iba-1 and c-Fos proteins in the spinal dorsal horn were detected by immunofluorescence staining; immunohistochemical method was used to detect the expression of GFAP protein in the spinal dorsal horn; Golgi staining was used to detect the number of dendritic spines in spinal dorsal horn neurons. PartⅡ: Thirty SD rats were randomly divided into a control group, a BDNF group and a BDNF+anti-TrkB group, 10 rats in each group. The control group was treated with intrathecal injection of 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and dimethyl sulfoxide (DMSO); the BDNF group was treated with intrathecal injection of 10 µg rat recombinant BDNF dissolved in 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and DMSO; the BDNF+anti-TrkB group was treated with intrathecal injection of 10 µg rat recombinant BDNF and 30 µg tyrosine kinase receptor B (TrkB) antibody dissolved in 10 µL mixture with 1︰1 of 0.9% sodium chloride solution and DMSO. The threshold of mechanical foot retraction reflex was detected 1 day before intrathecal injection and 1, 3 and 7 days after injection. Seven days after injection, the expression of c-Fos protein in the spinal dorsal horn was detected by Western blot and immunofluorescence staining. RESULTS: PartⅠ: Compared with the sham operation group, 3, 7 and 14 days after modeling, the latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex in the model group were decreased (P<0.05); 7 and 14 days after modeling, compared with the model group, the latency of thermal foot contraction reflex and the threshold of mechanical foot contraction reflex in the EA group were increased (P<0.05). The expressions of Iba-1, GFAP, BDNF, c-Fos proteins and the number of neuronal dendritic spines in the spinal dorsal horn in the model group were higher than those in the sham operation group (P<0.05); the expressions of Iba-1, BDNF, c-Fos proteins and the number of neuronal dendritic spines in the EA group were lower than those in the model group (P<0.05). PartⅡ: 3 and 7 days after intrathecal injection, the threshold of mechanical foot retraction reflex in the BDNF group was lower than that in the control group (P<0.05); the threshold of mechanical foot retraction reflex in the BDNF+anti-TrkB group was higher than that in the BDNF group (P<0.05). The expression of c-Fos protein in spinal dorsal horn in the BDNF group was higher than that in the control group (P<0.05); the expression of c-Fos protein in spinal dorsal horn in the BDNF+anti-TrkB group was lower than that in the BDNF group (P<0.05). CONCLUSION: The analgesic effect of EA at "Huantiao" (GB 30) and "Weizhong" (BL 40) on SNI rats may be related to inhibiting the activation of microglia in the dorsal horn of the spinal cord, thereby blocking the signal of microglia-BDNF-neuron, and finally reducing the excitability of neurons.