Differentiating mixed epithelial and stromal tumor family from predominantly cystic renal cell carcinoma using magnetic resonance imaging-based Bosniak classification system version 2019.

PURPOSE: To differentiate mixed epithelial and stromal tumor family (MESTF) of the kidney from predominantly cystic renal cell carcinoma (RCC) using the magnetic resonance imaging (MRI)-based Bosniak classification system version 2019 (v2019). MATERIALS AND METHODS: The study included 36 consecutive patients with MESTF and 77 with predominantly cystic RCC who underwent preoperative renal MRI. One radiologist evaluated and documented the clinical and MRI characteristics (age, sex, laterality, R.E.N.A.L. Nephrometry Score [RNS], surgical approach, the signal intensity on T2-weighted imaging, restricted diffusion and enhancement features in corticomedullary phase). Blinded to clinical and pathological information, another two radiologists independently evaluated Bosniak category of all masses. Interobserver agreement based on Bosniak classification system v2019 was measured by the weighted Cohen/Conger's Kappa coefficient. Furthermore, predominantly cystic RCCs and MESTFs were divided into low (categories I, II, and IIF) and high-class (categories III, and IV) tumors. The independent sample t test (Mann-Whitney U test) or Pearson Chi-square test (Fisher's exact probability test) was utilized to compare clinical and imaging characteristics between MESTFs and predominantly cystic RCCs. The performance of the Bosniak classification system v2019 in distinguishing MESTF from predominantly cystic RCC was investigated via receiver operating characteristic curve analysis. RESULTS: MESTF and predominantly cystic RCC groups significantly differed in terms of age, lesion size, RNS, restricted diffusion, and obvious enhancement in corticomedullary phase, but not sex, laterality, surgical approach, and the signal intensity on T2WI. Interobserver agreement was substantially based on the Bosniak classification system v2019. There were 24 low-class tumors and 12 high-class tumors in the MESTF group. Meanwhile, 13 low-class tumors and 64 high-class tumors were observed in the predominantly cystic RCC group. The distribution of low- or high-class tumors significantly differed between the MESTF and predominantly cystic RCC groups. Bosniak classification system v2019 had excellent discrimination (cutoff value = category III), and an area under curve value was 0.81; accuracy, 80.5%; sensitivity, 87.0%; and specificity, 66.7%. CONCLUSION: The MRI-based Bosniak classification system v2019 can effectively distinguish MESTF from predominantly cystic RCC if category III was used as a cutoff reference.

Study of the in situ test setup and analysis methods for self-healing properties of metallized film capacitors.

Metallized film capacitors (MFCs) are widely used in the power electronics industry due to their unique self-healing (SH) capability. SH performance is an essential assessment for MFC reliability verification in industrial production. The SH phenomenon of metallized films usually occurs rapidly in a very short period, and its real-time evolution details are often difficult to capture and analyze. In this paper, a test system for the SH performance of metallized films for capacitors was constructed. The system consists of three components: a voltage-current characteristic testing and current pulse capture device, a microscopic image real-time acquisition device, and an integrated analysis processing device. Through the voltage-current characteristic testing and current pulse capture device, the electrical parameters of the SH point, such as SH times, breakdown field strength, SH current, and SH energy, are obtained; through a microscopic image real-time acquisition device, the real-time spatial positioning of the SH point was obtained, and the interconnection between the morphology of the SH point and the electrical properties was established. The relationship between the SH point and the temperature distribution was further established using thermal imaging technology, which lays the foundation for a thorough and timely assessment and analysis of the failure mechanism and the real-time evolution of the metallized film SH process. This significantly improves the effectiveness of SH property research.

Renal cell carcinoma and venous tumor thrombus: predicting sarcomatoid dedifferentiation through preoperative IVIM-based MR imaging.

PURPOSE: To evaluate the value of preoperative intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and conventional MRI indicators in identifying sarcomatoid dedifferentiation in renal cell carcinoma (RCC) and tumor thrombus. METHODS: From September 2016 to April 2023, consecutive patients with RCC and tumor thrombus who received routine MRI examination and IVIM-DWI before radical resection were enrolled prospectively. Kaplan-Meier method with log-rank test was used to calculate and compare the survival probability. The preoperative imaging features were analyzed. Univariate and multivariable logistic regression analyses were employed to identify independent predictors of sarcomatoid dedifferentiation. The predictive ability was evaluated by receiver operating characteristic (ROC) curves. RESULTS: Twenty-two patients (15.3%) of the 144 patients in the training set (median age, 58.0 years [IQR, 52.0-65.0 years]; 108 men) and 11 patients (22.4%) of the 49 patients in the test set (median age, 58.0 years [IQR, 53.0-63.0 years]; 38 men) had sarcomatoid dedifferentiated tumors. Patients with sarcomatoid-differentiated tumors had poor progress-free survival in the training set and test set (P < 0.001 and P = 0.007). f value (P = 0.011), mN stage (P = 0.007), and necrosis (P = 0.041) were independent predictors for predicting sarcomatoid dedifferentiation in the training set. The model combining conventional MRI features and f value had AUCs of 0.832 (95% CI 0.755-0.909) and 0.825 (95% CI 0.702-0.948) in predicting sarcomatoid dedifferentiation in the training set and test set. CONCLUSION: It is feasible to preoperatively identify sarcomatoid dedifferentiation based on IVIM-DWI and conventional MR imaging indicators.

Assessment of the Added Value of Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging in Identifying Non-Diabetic Renal Disease in Patients With Type 2 Diabetes Mellitus.

BACKGROUND: Identification of non-diabetic renal disease (NDRD) in patients with type 2 diabetes mellitus (T2DM) may help tailor treatment. Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) is a promising tool to evaluate renal function but its potential role in the clinical differentiation between diabetic nephropathy (DN) and NDRD remains unclear. PURPOSE: To investigate the added role of IVIM-DWI in the differential diagnosis between DN and NDRD in patients with T2DM. STUDY TYPE: Prospective. POPULATION: Sixty-three patients with T2DM (ages: 22-69 years, 17 females) confirmed by renal biopsy divided into two subgroups (28 DN and 35 NDRD). FIELD STRENGTH/SEQUENCE: 3 T/ T2 weighted imaging (T2WI), and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI). ASSESSMENT: The parameters derived from IVIM-DWI (true diffusion coefficient [D], pseudo-diffusion coefficient [D*], and pseudo-diffusion fraction [f]) were calculated for the cortex and medulla, respectively. The clinical indexes related to renal function (eg cystatin C, etc.) and diabetes (eg diabetic retinopathy [DR], fasting blood glucose, etc.) were measured and calculated within 1 week before MRI scanning. The clinical model based on clinical indexes and the IVIM-based model based on IVIM parameters and clinical indexes were established and evaluated, respectively. STATISTICAL TESTS: Student's t-test; Mann-Whitney U test; Fisher's exact test; Chi-squared test; Intraclass correlation coefficient; Receiver operating characteristic analysis; Hosmer-Lemeshow test; DeLong's test. P < 0.05 was considered statistically significant. RESULTS: The cortex D*, DR, and cystatin C values were identified as independent predictors of NDRD in multivariable analysis. The IVIM-based model, comprising DR, cystatin C, and cortex D*, significantly outperformed the clinical model containing only DR, and cystatin C (AUC = 0.934, 0.845, respectively). DATA CONCLUSION: The IVIM parameters, especially the renal cortex D* value, might serve as novel indicators in the differential diagnosis between DN and NDRD in patients with T2DM. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging and Venous Tumor Thrombus Consistency in Renal Cell Carcinoma.

BACKGROUND: Venous tumor thrombus (VTT) consistency of renal cell carcinoma (RCC) is an important consideration in nephrectomy plus thrombectomy. However, evaluation of VTT consistency through preoperative MR imaging is lacking. PURPOSE: To evaluate VTT consistency of RCC through intravoxel incoherent motion-diffusion weighted imaging (IVIM-DWI) derived parameters (Dt , Dp , f, and ADC) and the apparent diffusion coefficient (ADC) value. STUDY TYPE: Retrospective. POPULATION: One hundred and nineteen patients (aged 55.8 ± 11.5 years, 85 male) with histologically-proven RCC and VTT who underwent radical resection. FIELD STRENGTH/SEQUENCES: 3.0-T; two-dimensional single-shot diffusion-weighted echo planar imaging sequence at 9 b-values (0-800 s/mm2 ). ASSESSMENT: IVIM parameters and ADC values of the primary tumor and the VTT were calculated. The VTT consistency (friable vs. solid) was determined through intraoperative findings of two urologists. The accuracy of VTT consistency classification based on the individual IVIM parameters of primary tumors and of VTT, and based on models combining parameters, was assessed. Type of operation, intra-operative blood loss, and operation length were recorded. STATISTICAL TESTS: Shapiro-Wilk test; Mann-Whitney U test; Student's t-test; Chi-square test; Receiver operating characteristic (ROC) analysis. Statistical significance level was P < 0.05. RESULTS: Of the enrolled 119 patients, 33 patients (27.7%) had friable VTT. Patients with friable VTT were significantly more likely to experience open surgery, have significantly more intraoperative blood loss, and significantly longer operative duration. The area under the ROC curve (AUC) values of Dt of the primary tumor and VTT in classifying VTT consistency were 0.758 (95% CI 0.671-0.832) and 0.712 (95% CI 0.622-0.792), respectively. The AUC value of the model combining Dp and Dt of VTT was 0.800 (95% CI 0.717-0.868). Furthermore, the AUC of the model combining Dp and Dt of VTT and Dt of the primary tumor was 0.886 (95% CI 0.814-0.937). CONCLUSION: IVIM-derived parameters had the potential to predict VTT consistency of RCC. EVIDENCE LEVEL: 3 Technical Efficacy: Stage 2.

New insight into the analgesic recipe: A cohort study based on smart patient-controlled analgesia pumps records.

Purpose: Intravenous patient-controlled analgesia (IV-PCA) has been widely used; however, regimen criteria have not yet been established. In China, the most often used opioid is sufentanil, for which repeated doses are a concern, and empirical flurbiprofen axetil (FBP) as an adjuvant. We hypothesized that hydromorphone would be a better choice and also evaluated the effectiveness of FBP as an adjuvant. Methods: This historical cohort study was conducted in two tertiary hospitals in China and included 12,674 patients using hydromorphone or sufentanil for IV-PCA between April 1, 2017, and January 30, 2021. The primary outcome was analgesic insufficiency at static (AIS). The secondary outcomes included analgesic insufficiency with movement (AIM) and common opioid-related adverse effects such as postoperative nausea and vomiting (PONV) and dizziness. Results: Sufentanil, but not the sufentanil-FBP combination, was associated with higher risks of AIS and AIM compared to those for hydromorphone (OR 1.64 [1.23, 2.19], p < 0.001 and OR 1.42 [1.16, 1.73], p < 0.001). Hydromorphone combined with FBP also decreased the risk of both AIS and AIM compared to those for pure hydromorphone (OR 0.74 [0.61, 0.90], p = 0.003 and OR 0.80 [0.71, 0.91], p < 0.001). However, the risk of PONV was higher in patients aged ≤35 years using FBP (hydromorphone-FBP vs. hydromorphone and sufentanil-FBP vs. hydromorphone, OR 1.69 [1.22, 2.33], p = 0.001 and 1.79 [1.12, 2.86], p = 0.015). Conclusion: Hydromorphone was superior to sufentanil for IV-PCA in postoperative analgesia. Adding FBP may improve the analgesic effects of both hydromorphone and sufentanil but was associated with an increased risk of PONV in patients <35 years of age.

Plasma amyloid beta level changes in aged mice with cognitive dysfunction following sevoflurane exposure.

INTRODUCTION: Previous studies have stated that cognitive impairment induced by anesthetics was associated with amyloid beta (Aß). However, few researchers have investigated the transport of Aß inside and outside of the brain. AIM: We attempted to probe the effects of sevoflurane on cognitive functions, the plasma Aß, and transporters of Aß in aged mice. The receptor for advanced glycation end-products (RAGE) is an Aß influx protein, and Low-density lipoprotein receptor-related protein-1 (LRP-1) is an Aß efflux protein. METHODS: Aged mice were divided into the control group and the sevoflurane group. The mice were exposed to 100% oxygen or 2.5% sevoflurane for 2 h. The abilities of spatial learning and memory in mice were tested using the Morris water maze. Aß concentrations of plasma were measured with enzyme-linked immunosorbent assay kits. The RAGE and LRP-1 gene levels in the brain were assessed with quantitative polymerase chain reaction, and the protein levels were determined by western blot analysis. The locations of RAGE in the brain were confirmed via immunofluorescence. RESULTS: In the sevoflurane group mice, the escape latency was increased on the 5th day of training, and the time spent in the target quadrant was decreased on the 7th day after anesthesia. Sevoflurane reduced the concentration of plasma Aß1-40. In addition, sevoflurane increased both gene and protein levels of RAGE in the brain, and increased RAGE proteins co-localized with the hippocampal vascular endothelial cells. CONCLUSION: RAGE over-expression in the hippocampal vascular endothelial cells possibly resulted in the excessive transport of the plasma Aß1-40 into the brain after treatment with sevoflurane, which was associated with sevoflurane-induced cognitive dysfunction in aged mice.

The effect of celastrol on learning and memory in diabetic rats after sevoflurane inhalation.

INTRODUCTION: The aim was to devise an animal model showing some of the neuropathological changes seen in senile dementia, and to investigate the effect of celastrol on cognition neuropathology in this model. MATERIAL AND METHODS: Forty male Sprague Dawley rats weighing 300-350 g were randomly divided into 5 groups (n = 8 each): control (Con); inhaled sevoflurane (Sev); diabetes mellitus (DM); diabetes mellitus + inhaled sevoflurane (DM/Sev); diabetes + inhaled sevoflurane + celastrol (Cel). Diabetes was induced by an intraperitoneal injection of streptozotocin (STZ). After 20 days, the Sev, DM/Sev and Cel group rats inhaled 3% sevoflurane for 2 h, while the control and DM groups inhaled air. Cel group rats were given intraperitoneal injections of celastrol (0.7 mg/kg) daily for 4 days, while the control group received intraperitoneal injections of an equal volume of dimethylsulfoxide. The Morris water maze test was performed to test cognition. Animals were killed after the last water maze test and Congo red staining was used to observe deposition of amyloid substance in the hippocampus. The expression of GFAP and IGF-1 in the hippocampus was observed by immunohistochemistry. RESULTS: Diabetes decreased cognition, increased amyloid substance and GFAP expression, and decreased IGF-1 expression in the hippocampus (all p-values < 0.05). Sevoflurane administration intensified and celastrol decreased these changes (all p-values < 0.05). CONCLUSIONS: Sev/DM rats showed cognitive and neurochemical changes similar to those seen in senile dementia. Celastrol decreased these changes and should be evaluated further as a possible clinical agent in dementia.

Isoflurane anesthesia induces liver injury by regulating the expression of insulin-like growth factor 1.

It has been suggested that isoflurane may cause perioperative liver injury. However, the mechanism of its action remains unknown. The purpose of the present study was to determine this possible mechanism. Sprague-Dawley rats were randomly assigned into one of three groups (all n=12): Control group (exposed to mock anesthesia), isoflurane group (exposed to 2% isoflurane for 90 min), and isoflurane + insulin-like growth factor 1 (IGF-1) group (exposed to 2% isoflurane for 90 min and then treated with IGF-1). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were conducted to determine the levels of expression of IGF-1 and its receptor IGF-R. Liver necrosis was assessed by histological examination. TUNEL assay was performed to determine the apoptosis of hepatic cells. In addition, the levels of the proteins caspase-3 and B-cell lymphoma-extra large (Bcl-xL) were measured. Compared with the control group, levels of IGF-1 and IGF-1R mRNA and protein were significantly decreased following exposure to isoflurane (all P<0.05). The necrosis rate and liver apoptosis were significantly increased in the group treated with isoflurane alone compared with the control group (P<0.05), but were significantly decreased compared with the isoflurane group following application of IGF-1 (P<0.05). Additionally, isoflurane exposure significantly increased levels of caspase-3 compared with the control group (P<0.05), but decreased levels of Bcl-xL (P<0.05). By contrast, application of IGF-1 reversed these changes. The present study therefore suggests that isoflurane induces liver injury in part by regulating the expression of IGF-1 and that application of IGF-1 may protect against liver injury induced by isoflurane exposure.

Evaluation of Neuroprotective Effect of Thymoquinone Nanoformulation in the Rodent Cerebral Ischemia-Reperfusion Model.

The purpose of the present study was to evaluate the neuroprotective efficacy of optimized thymoquinone loaded PLGA-chitosan nanoparticles delivered via nose to brain route in the rodent cerebral ischemia-reperfusion model. The neuroprotective efficacy of the optimized thymoquinone loaded PLGA-chitosan nanoparticles was evaluated in middle cerebral artery occluded rats by various pharmacodynamic and biochemical studies. The pharmacokinetics of thymoquinone loaded PLGA-chitosan nanoparticles in the brain and blood plasma together with qualitative localization of florescent labelled PLGA-chitosan nanoparticles in brain tissues were also determined. Intranasal delivery of optimized thymoquinone loaded PLGA-chitosan nanoparticles (183.5 ± 8.2 nm, 33.63 ± 2.25 mV) to brain significantly reduced the ischemia infarct volume and enhanced the locomotor activity and grip strength in the middle cerebral artery occluded rats. Biochemical studies showed that intranasal delivery of thymoquinone loaded PLGA-chitosan nanoparticles significantly reduced the lipid peroxidation but elevated the glutathione, catalase, and superoxide dismutase in the brain of middle cerebral artery occluded rats. The pharmacokinetic and localization studies showed that thymoquinone loaded PLGA-chitosan nanoparticles facilitated the delivery of thymoquinone to brain by intranasal nose to brain transport pathways and enhanced their pharmacokinetic profile in brain tissues. Thus, intranasal delivery of thymoquinone loaded PLGA-chitosan nanoparticles to brain could be potentially used for the neuroprotection and treatment of cerebral ischemia.

Comparison of recovery parameters for xenon versus other inhalation anesthetics: systematic review and meta-analysis.

STUDY OBJECTIVE: To summarize and evaluate the available data describing the recovery parameters of xenon anesthesia. DESIGN: Systematic review and meta-analysis. SETTING: Anesthesia for elective surgeries. PATIENTS: Systematic review of randomized controlled trials (RCTs) from databases including Medline (1964-2013), the Cochrane Central Register of Controlled Trials (CENTRAL, 1990-2012), and Google Scholar (1966-2013). INTERVENTIONS: Inhalation of xenon or other anesthetics was administered in elective surgery. MEASUREMENTS: Recovery parameters (time to recovery, alertness/sedation scale scores at "eye opening," bispectral index at "reaction on demand," time to extubation, and time to orientation). MAIN RESULTS: Eleven RCTs (N = 661 patients) met the inclusion criteria. Recovery from xenon anesthesia was significantly faster in terms of the time to eye opening (mean difference [MD], -4.18 minutes; 95% confidence interval [CI], -5.03 to -3.32 minutes; P < .00001), the time to reaction on demand (MD, -5.35 minutes; 95% CI, -6.59 to -4.11 minutes; P < .00001), the time to extubation (MD, -4.49 minutes; 95% CI, -5.40 to -3.58 minutes; P < .00001), and the time to orientation (MD, -4.99 minutes; 95% CI, -6.45 to -3.52 minutes; P < .00001). CONCLUSIONS: This meta-analysis confirmed that recovery from xenon anesthesia is faster than other inhalation anesthesia.

Diabetes Worsens Ischemia-Reperfusion Brain Injury in Rats Through GSK-3ß.

BACKGROUND: Diabetes aggravates brain injury after cerebral ischemia/reperfusion (I/R). OBJECTIVE: To investigate whether limb I/R causes cerebral injury in a rat diabetes model and whether glycogen synthase kinase-3ß (GSK-3ß) is involved. METHODS: Male adult Sprague-Dawley rats were assigned into streptozotocin-induced diabetes (n = 30; blood glucose ≥16.7 mmol/L) or control (n = 20) groups, further subdivided into diabetes I/R (3-hour femoral artery/vein clamping), diabetes-I/R + TDZD-8 (I/R plus GSK-3ß inhibitor), diabetes-sham, control-sham and control-I/R groups (n = 10 each). Cortical and hippocampal morphology (hematoxylin/eosin); hippocampal CA1 apoptosis (TUNEL assay); cleaved caspase-3 (apoptosis), and Iba1 (microglial activation) protein expression (immunohistochemistry); phosphorylated/total GSK-3ß and nuclear factor-κB (NF-κB) protein levels (Western blotting); and serum and brain tissue tumor necrosis factor (TNF)-α levels (enzyme-linked immunosorbent assay) were analyzed. RESULTS: The diabetes-I/R group showed greater cortical and hippocampal injury, apoptosis, cleaved caspase-3 expression and Iba1 expression than the control-I/R group; TDZD-8 reduced injury/apoptosis and cleaved caspase-3/Iba1 expressions. The diabetes-I/R group had lower p-GSK-3ß and p-NF-κBp65 expression than the control-I/R group (P < 0.05); TDZD-8 increased p-GSK-3ß expression but decreased p-NF-κBp65 expression (P < 0.05). The diabetes-I/R group showed higher elevation of serum and brain tissue TNF-α than the control-I/R group (P < 0.05); TDZD-8 reduced TNF-α production. CONCLUSIONS: Diabetes exacerbates limb I/R-induced cerebral damage and activates NF-κB and GSK-3ß.

Effects of sevoflurane pretreatment on renal Src and FAK expression in diabetic rats after renal ischemia/reperfusion injury.

The diabetic kidney is sensitive to ischemia-reperfusion (I/R) injury due to microvascular complications, such as cellular apoptosis and necrosis. The aim of this study was to determine if sevoflurane pretreatment could help preserve renal function in rats with diabetes mellitus (DM) by altering non-receptor tyrosine kinases steroid receptor coactivator (Src) and focal adhesion kinase (FAK) expression (Src and FAK are mediators of cellular apoptosis and necrosis). Male rats (N = 40) were randomly assigned to one of five groups: Group A, sham operation; Group B, renal I/R injury; Group C, DM + sham operation; Group D, DM + renal I/R injury; and Group E, DM + sevoflurane pretreatment + renal I/R injury. Sevoflurane pretreatment comprised exposure to 2.5 % sevoflurane for 30 min, followed by exposure to air for 10 min. After 24 h, serum creatinine (Cr) and blood urea nitrogen (BUN) levels, and renal Src and FAK expression (immunohistochemistry) were assessed. Compared with rats in C, rats in D had significantly higher Cr and BUN levels, but significantly lower renal Src and FAK expression. Rats in E had significantly lower serum Cr and BUN levels and significantly higher renal Src and FAK expression levels than rats in D. Our findings suggest that sevoflurane pretreatment in rats with DM protects the kidneys from ischemia/reperfusion injury in part due to increased renal Src and FAK expression.

[Relationship between dynamic contrast-enhanced and perfusion magnetic resonance imaging and T-staging of nasopharyngeal carcinoma].

OBJECTIVE: To perform the dynamic contrast-enhanced and perfusion magnetic resonance imaging (MRI) of nasopharyngeal carcinoma (NPC) and analyze the correlation with T-staging. METHODS: A total of 46 naïve NPC patients underwent MRI. The parameters of dynamic contrast-enhanced and perfusion MRI included time to peak (TTP), Slopemax and area under the curve (AUC). RESULTS: The increasing period of signal intensity-time curve of all cases was steep. And the perfusion image of AUC could reflect the blood perfusion of tumor tissue. Parameters (TTP/Slopemax/AUC) in different T-staging were T1-staging (60.45/10.59/20 619.56), T2-staging (58.12/12.47/23 037.23), T3-staging (70.61/15.06/26 507.23) and T4-staging (41.72/19.87/30 092.27). Their statistical results were r = -0.247, P > 0.05 and r = 0.859, P < 0.050 and r = 0.963, P < 0.05 respectively. And statistical significance existed in Slopemax, AUC with T-staging. CONCLUSION: Dynamic contrast-enhanced and perfusion MRI can reflect angiogenesis of NPC. And there is a positive correlation between the parameters of dynamic contrast-enhanced and perfusion MRI (Slopemax, AUC) and T-staging.

Protective effect of sevoflurane on hepatic ischaemia/reperfusion injury in the rat: A dose-response study.

BACKGROUND: Ischaemia/reperfusion injury is a common problem in hepatic surgery. An appreciation of the role of sevoflurane dose in preconditioning and subsequent hepatoprotection against ischaemia/reperfusion injury would be useful. OBJECTIVE: The aim of current study was to investigate the protective effect of sevoflurane preconditioning at different doses on hepatic ischaemia/reperfusion injury in rats. DESIGN: Randomised, controlled, laboratory study. SETTING: The Department of Anaesthesiology, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China. PARTICIPANTS: Fifty male Sprague-Dawley rats weighing 200 to 250 g, randomly assigned to five groups. INTERVENTIONS: Control group (sham surgery, no ischaemia/reperfusion), I/R group (ischaemia/reperfusion but no sevoflurane pretreatment), S1 [1 minimum alveolar concentration (MAC) = 2.4%], S2 (1.5 MAC = 3.6%) and S3 (2 MAC = 4.8%) groups with sevoflurane pretreatment, respectively, followed by 60 min ischaemia and 120 min reperfusion. MAIN OUTCOME MEASURES: At the end of reperfusion, serum levels of alanine aminotransferase and aspartate aminotransferase as well as superoxide dismutase activity, myeloperoxidase and malondialdehyde content in the liver were determined. Histological examination of the liver was also performed. RESULTS: Serum levels of aspartate aminotransferase and alanine aminotransferase in the sevoflurane groups were significantly reduced compared to the elevated levels seen in the I/R group (P < 0.05). In the liver, the I/R-induced increase in myeloperoxidase activity and malondialdehyde level were significantly reduced by all sevoflurane concentrations (P < 0.05). The decrease in superoxide dismutase activity induced by I/R was prevented by all sevoflurane pretreatments (P < 0.05). No significant differences between the S1, S2 and S3 groups were seen in any of the above variables. CONCLUSION: Sevoflurane pretreatment exerts a protective effect on hepatic ischaemia/reperfusion injury but there is no significant dose-response relationship in the concentration range used. It is possible that a dose-response relationship might exist at lower concentrations.

Apoptosis in glioma-bearing rats after neural stem cell transplantation.

Abnormal activation of the Ras/Raf/Mek/Erk signaling cascade plays an important role in glioma. Inhibition of this aberrant activity could effectively hinder glioma cell proliferation and promote cell apoptosis. To investigate the mechanism of glioblastoma treatment by neural stem cell transplantation with respect to the Ras/Raf/Mek/Erk pathway, C6 glioma cells were prepared in suspension and then infused into the rat brain to establish a glioblastoma model. Neural stem cells isolated from fetal rats were then injected into the brain of this glioblastoma model. Results showed that Raf-1, Erk and Bcl-2 protein expression significantly increased, while Caspase-3 protein expression decreased. After transplantation of neural stem cells, Raf-1, Erk and Bcl-2 protein expression significantly decreased, while Caspase-3 protein expression significantly increased. Our findings indicate that transplantation of neural stem cells may promote apoptosis of glioma cells by inhibiting Ras/Raf/Mek/Erk signaling, and thus may represent a novel treatment approach for glioblastoma.