Utility of gadoxetate disodium-enhanced magnetic resonance imaging in evaluating liver failure risk after major hepatic resection.

Background: Post-hepatectomy liver failure (PHLF) is still a predominant cause of hepatectomy-related mortality. However, it is difficult to evaluate the remnant liver functional reserve accurately before surgery to prevent PHLF. In this study, we aimed to explore the role of gadoxetate disodium-enhanced magnetic resonance imaging (MRI) in evaluating remnant liver functional reserve. Methods: For this cross-sectional study, the sample retrospectively included 56 patients undergoing liver resections of at least three segments between June 2019 and September 2022 at The General Hospital of the Western Theater Command. Pre-surgery assessments involved liver computer tomography (CT), an indocyanine green (ICG) clearance test, the Child-Pugh scoring system, and liver function serum biochemical indicators. Each patient underwent a gadoxetate disodium-enhanced MRI before the hepatectomy, and we measured the remnant hepatocellular uptake index (rHUI) as well as the standard remnant hepatocellular uptake index (SrHUI). We examined the diagnostic utility of rHUI, SrHUI, indocyanine green retention rate of 15 minutes (ICG R15), and Albumin for PHLF. Receiver operating characteristics (ROC) analyses were used to measure the preoperative liver function parameters (namely, rHUI, SrHUI, ICG R15, and Albumin) for predicting PHLF. The areas under the curve (AUCs) were calculated and compared between different preoperative liver function parameters using the Wilson/Brown method. The Pearson or Spearman correlation coefficient was used for correlation analysis between ICG R15, Albumin, and rHUI and between ICG R15, Albumin, and SrHUI, respectively. Results: Twelve patients (21.43%) had complications of PHLF. We found significant differences in rHUI, SrHUI, ICG R15, and Albumin between the non-PHLF and PHLF groups. The pooled r between ICG R15 and rHUI was -0.591 [95% confidence interval (CI): -0.740 to -0.389, P<0.001], and between ICG R15 and SrHUI was -0.534 (95% CI: -0.703 to -0.308, P<0.001). The area under the curve (AUC) values of rHUI, SrHUI, ICG R15, and Ablumin were 0.871 (sensitivity 81.82%; specificity 91.67%), 0.878 (sensitivity 79.55%; specificity 83.33%), 0.835 (sensitivity 99.73%; specificity 66.67%), and 0.782 (sensitivity 88.64%; specificity 58.33%), respectively. Conclusions: We found that the rHUI and SrHUI calculated using the gadoxetate disodium-enhanced MRI reflected a combination of remnant hepatocyte function and liver volume, and these were useful as a quantitative assessment indicator of remnant liver functional reserve and can be a better predictor of PHLF after major hepatic resection.

Establishment of a Rabbit Model of Chronic Obstructive Sleep Apnea and Application in Cardiovascular Consequences.

BACKGROUND: Although obstructive sleep apnea (OSA) has been recognized as a major risk factor for cardiovascular complications and its clinical features are well characterized, it is difficult to replicate the OSA hypoxic model in humans. We aimed to establish an experimental rabbit model for chronic OSA and to explore its application to measure blood pressure (BP), myocardial systolic function, and oxidative stress. METHODS: The rabbit model for OSA was established by repeatedly closing the airway and then reopening it. A tube specially designed with a bag that could be alternately inflated and deflated according to a predetermined time schedule, resulting in recurrent airway occlusions and chronic intermittent hypoxia (CIH) imitating OSA patterns in humans, was used. Twenty-four rabbits were randomly divided into obstruction, sham, and control groups, and their upper airways were alternately closed for 15 s and then reopened for 105 s in a 120-s-long cycle, for 8 h each day over 12 consecutive weeks. Before and after the experiment, the BP of each rabbit was monitored. Levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the serum, superoxide dismutase (SOD) activity, malondialdehyde (MDA) and reactive oxygen species (ROS) contents, as well as Na+-K+-ATPase/Ca2+-ATPase activities in cardiac muscle were examined. In addition, cardiac functional parameters were measured using echocardiography. RESULTS: After 3 months, all rabbits in the obstruction group manifested sleepiness performance similar to that observed in OSA patients. Traces of airflow and SpO2showed that this model mimicked the respiratory events involved in OSA, including increased respiratory effort and decreased oxygen saturation. Gradually, the BP rose each month. CIH led to obvious oxidative stress and injured myocardial systolic performance. The serum levels of IL-6 and TNF-α increased significantly (64.75 ± 9.05 pg/ml vs. 147.00 ± 19.24 pg/ml and 59.38 ± 8.21 pg/ml vs. 264.75 ± 25.54 pg/ml, respectively, both P < 0.001). Compared with the sham and the control groups, myocardial activities of Na+-K+-ATPase/Ca2+-ATPase and SOD in the obstruction group decreased markedly, while ROS and MDA content increased. CONCLUSIONS: These results show that the rabbit model for OSA simulates the pathophysiological characteristics of OSA in humans, which implies that this animal model is feasible and useful to study the mechanisms involved in the cardiovascular consequences of OSA.

Anti-tumor activity of tanshinone IIA in combined with cyclophosphamide against Lewis mice with lung cancer.

OBJECTIVE: To explore the anti-tumor activity of tanshinone IIA in combined with cyclophosphamide against Lewis mice with lung cancer and the effect on cellular immune function. METHODS: Lewis tumor cells were inoculated subcutaneously into the right armpit of mice in each group (n = 20) to establish Lewis lung cancer mice model. After model establishment, mice in the model group were given normal saline by lavage, qd. Mice in treatment I group were given intraperitoneal injection of Tan IIA, 15 mg/kg, qd. Mice in treatment II group were given intraperitoneal injection of CTX, 25 mg/kg, qd. Mice in treatment III group were given intraperitoneal injections of Tan IIA and CTX, in which the administration method of Tan IIA was the same as in treatment I group, continuously for 2 weeks, and the dosage of CTX was the same as in treatment II group, 24 h after model establishment, every other day. Mice were sacrificed 2 weeks after establishment. The tumor tissues were collected to calculate the anti-tumor rate. Immunohistochemistry was used to detect the expressions of Bcl-2, Bax, VEGF, Angiostatin, and Endostatin. FCM was used to detect T lymphocyte subsets in spleen and liver of mice. RESULTS: The tumor weight in treatment I, II, and III groups was significantly lower than that in the model group (P < 0.05). The tumor weight in treatment III group was significantly lower than that in treatment I and II groups (P < 0.05). The anti-tumor rate in treatment II and III groups was significantly higher than that in treatment I group (P < 0.05). Bcl-2 expression in the tumor tissues of treatment I, II, and III groups was significantly lower than that in the model group (P < 0.05), while Bax expression was significantly higher than that in the model group (P < 0.05). Bcl-2 expression in the tumor tissues of treatment I and II groups was significantly higher than that in treatment III group (P < 0.05), while Bax expression was significantly lower than that in treatment III group (P < 0.05). CD4+ and CD4+/CD8+ in treatment I, II, and III groups were significantly higher than those in the model group (P < 0.05). CD4+ in treatment III group was significantly higher than that in treatment I and II groups (P < 0.05), while CD4+/CD8+ was significantly higher than that in treatment II group (P < 0.05). The comparison of CD8+ among each group was not statistically significant (P > 0.05). NK cell activity in treatment I, II, and III groups was significantly higher than that in the model group (P < 0.05). NK cell activity in treatment III group was significantly higher than that in treatment I and II groups (P < 0.05). CONCLUSIONS: Tan IIA in combined with CTX can down regulate Bcl-2 expression in lung cancer tissues, up regulate Bax expression, inhibit the neovascularization of tumor tissues, and enhance the immunological function, with a significant anti-tumor activity.