Objective:To analyze the changes and significance in clinical cardiac indicators of early cardiac myocardial dysfunction and cardiac substructure dose during conventional radiotherapy for N 2-N 3 non-small cell lung cancer (NSCLC) with mediastinal lymph node metastases. Methods:The data of 34 NSCLC patients with lymph node metastases in regions 4-8 admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to August 2023 were observed and analyzed. All patients were treated with volumetric modulated arc therapy with a prescribed dose of 60-70 Gy. Cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at 6 time points: within 1 week before radiotherapy ( t0); when the cumulative radiotherapy dose reaches 20 Gy ( t20), 40 Gy ( t40), 60 Gy ( t60) during radiotherapy; within 1 week after radiotherapy ( tp); 1 month after radiotherapy( tp1). Left ventricular global longitudinal strain (LVGLS) and left atrial global longitudinal strain (LAGLS) were assessed at 4 time points: t0, t40, tp and tp1, respectively. The changes in cardiac indicators at different time points during radiotherapy and their correlation with substructure doses were analyzed using analysis of variance, linear regression analysis, and Pearson correlation. Results:The correlation between cardiac substructure dose and mean heart dose (MHD) in the study cohort in the descending order was as follows: left ventricle ( B=0.43, P<0.001), right ventricle ( B=0.37, P=0.002), left atrium ( B=0.16, P<0.001), and right atrium ( B=0.15, P=0.001). There were significant differences in the changes of LVGLS and LAGLS across different time points ( F=3.13, P=0.029; F=17.18, P<0.001). At 1 month after radiation, LAGLS was significantly decreased compared to pre-radiation levels ( P=0.009), whereas no significant difference was observed in LVGLS ( P=1.000). No significant differences were observed in the changes of cTnT and NT-proBNP across different time points (all P>0.05). Significant correlations were identified between cTnT and right ventricle mean dose at t40 ( r=0.38, P=0.025), as well as between NT-proBNP and right atrium mean dose at t60 and tp ( r=0.54, P=0.001; r=0.41, P=0.016). Conclusions:At present, there is no significant difference between the sensitive serum markers of myocardial injury and LVGLS in detecting early myocardial injury. LAGLS may hold substantial clinical value. There is uncertainty about radiation injury and repair of various cardiac substructures.

Objective:To analyze the changes and significance in clinical cardiac indicators of early cardiac myocardial dysfunction and cardiac substructure dose during conventional radiotherapy for N 2-N 3 non-small cell lung cancer (NSCLC) with mediastinal lymph node metastases. Methods:The data of 34 NSCLC patients with lymph node metastases in regions 4-8 admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to August 2023 were observed and analyzed. All patients were treated with volumetric modulated arc therapy with a prescribed dose of 60-70 Gy. Cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at 6 time points: within 1 week before radiotherapy ( t0); when the cumulative radiotherapy dose reaches 20 Gy ( t20), 40 Gy ( t40), 60 Gy ( t60) during radiotherapy; within 1 week after radiotherapy ( tp); 1 month after radiotherapy( tp1). Left ventricular global longitudinal strain (LVGLS) and left atrial global longitudinal strain (LAGLS) were assessed at 4 time points: t0, t40, tp and tp1, respectively. The changes in cardiac indicators at different time points during radiotherapy and their correlation with substructure doses were analyzed using analysis of variance, linear regression analysis, and Pearson correlation. Results:The correlation between cardiac substructure dose and mean heart dose (MHD) in the study cohort in the descending order was as follows: left ventricle ( B=0.43, P<0.001), right ventricle ( B=0.37, P=0.002), left atrium ( B=0.16, P<0.001), and right atrium ( B=0.15, P=0.001). There were significant differences in the changes of LVGLS and LAGLS across different time points ( F=3.13, P=0.029; F=17.18, P<0.001). At 1 month after radiation, LAGLS was significantly decreased compared to pre-radiation levels ( P=0.009), whereas no significant difference was observed in LVGLS ( P=1.000). No significant differences were observed in the changes of cTnT and NT-proBNP across different time points (all P>0.05). Significant correlations were identified between cTnT and right ventricle mean dose at t40 ( r=0.38, P=0.025), as well as between NT-proBNP and right atrium mean dose at t60 and tp ( r=0.54, P=0.001; r=0.41, P=0.016). Conclusions:At present, there is no significant difference between the sensitive serum markers of myocardial injury and LVGLS in detecting early myocardial injury. LAGLS may hold substantial clinical value. There is uncertainty about radiation injury and repair of various cardiac substructures.

Objective To evaluate the relationship between hydrogen sulfide (H2S) and P2X3 receptors in dorsal root ganglions (DRGs) of rats with neuropathic pain (NP).Methods Thirty-six healthy male Sprague-Dawley rats,aged 4-6 weeks,weighing 180-200 g,in which IT catheters were successfully implanted,were divided into 3 groups (n=12 each) using a random number table method:sham operation group (group S),group NP and endogenous H2S synthase (cystathionine beta-syntheses [CBS]) inhibitor animooxyacetic acid (AOAA) group (group A).NP was induced by chronic constriction injury (CCI) to the sciatic nerve at 3 days after IT catheters were successfully implanted.AOAA (10 μg/kg) 10 μl and normal saline 10 μl were intrathecally injected once a day for 14 consecutive days starting from 1 day after CCI in group A,and normal saline 20 μl was intrathecally injected instead in S and NP groups.At 1 day before CCI and 1,3,7,10 and 14 days after CCI,the thermal paw withdrawal latency (TWL) and mechanical paw withdrawal threshold (MWT) were measured at 30 min after intrathecal injection.The animals were sacrificed at 7 and 14 days after CCI,and ipsilateral DRGs of the lumbar segment (L4-6) were removed for detection of the expression of CBS and P2X3 receptors by Western blot.Results Compared with group S,the TWL was significantly shortened,MWT was decreased,and the expression of CBS and P2X3 receptors in DRGs was up-regulated at each time point after CCI in group NP (P＜0.05).Compared with group NP,the TWL was significantly prolonged,the MWT was increased,and the expression of CBS and P2X3 receptors in DRG s was down-regulated at each time point after CCI in group A (P＜0.05).Conclusion H2S in DRG s can up-regulate the expression of P2X3 receptors,which may be involved in the pathophysiological mechanism of NP in rats.