Characteristics of bone tunnel changes after anterior cruciate ligament reconstruction using Ligament Advanced Reinforcement System artificial ligament

Background  There are different materials used for anterior cruciate ligament (ACL) reconstruction. It has been reported that both autologous grafts and allografts used in ACL reconstruction can cause bone tunnel enlargement. This study aimed to observe the characteristics of bone tunnel changes and possible causative factors following ACL reconstruction using Ligament Advanced Reinforcement System (LARS) artificial ligament.

Methods  Forty-three patients underwent ACL reconstruction using LARS artificial ligament and were followed up for 3 years. X-ray and CT examinations were performed at 1, 3, 6, 12, 24, and 36 months after surgery, to measure the width of tibial and femoral tunnels. Knee function was evaluated according to the Lysholm scoring system. The anterior and posterior stability of the knee was measured using the KT-1000 arthrometer.

Results  According to the Peyrache grading method, grade 1 femoral bone tunnel enlargement was observed in three cases six months after surgery. No grade 2 or grade 3 bone tunnel enlargement was found. The bone tunnel enlargement in the three cases was close to the articular surface with an average tunnel enlargement of (2.5±0.3) mm. Forty cases were evaluated as grade 0. The average tibial and femoral tunnel enlargements at the last follow-up were (0.8±0.3) and (1.1±0.3) mm, respectively. There was no statistically significant difference in bone tunnel width changes at different time points (P >0.05). X-ray and CT measurements were consistent.

Conclusions  There was no marked bone tunnel enlargement immediately following ACL reconstruction using LARS artificial ligament. Such enlargement may, however, result from varying grafting factors involving the LARS artificial ligament or from different fixation methods.

     

Anatomical study of the anterolateral and posteromedial bundles of the posterior cruciate ligament for double-bundle reconstruction using the quadruple bone-tunnel technique

Background  Several techniques have been described for posterior cruciate ligament (PCL) reconstruction. However, double-bundle PCL reconstruction using the quadruple bone-tunnel technique has been seldom reported. The current study investigated this technique, focusing on the anatomy of the femoral and tibial insertions of the anterolateral (AL) and posteromedial (PM) bundles of the PCL.

Methods  Twenty-two fresh, healthy adult cadaveric knees were dissected and measured. The PCL was divided into the AL bundle and PM bundle at the insertion footprint. The insertion footprints of the AL and PM bundles, their location, size, and the clock positions were measured and described.

Results  On the femur, the clock position of the footprint of the AL bundle was 11:21±0:23 (left) or 0:39±0:23 (right), and the PM bundle was 9:50±0:18 (left) or 2:10±0:18 (right), with the knee flexed at 90 degrees. The distances from the center of the femoral insertions of the AL and PM bundles to the anterior cartilage margins of the medial femoral condyle were (7.79±1.22) mm and (8.36±1.63) mm, respectively. On the tibia, the vertical distances from the center of the tibial insertions of the AL and PM bundles to the tibial articular surface were (3.25±1.20) mm and (6.91±1.57) mm, respectively.

Conclusions  These results have led to a better definition of the anatomy of the AL and PM bundle footprint of the PCL. The technique of double-bundle PCL reconstruction using quadruple bone-tunnel is feasible. Application of these data during PCL reconstruction using the quadruple bone-tunnel technique may help optimize knee stability.

     

Ibutilide decreases defibrillation threshold by the reduction of activation pattern complexity during ventricular fibrillation in canine hearts

Background  Ibutilide has been commonly used for pharmacologic cardioversion of atrial fibrillation and flutter in clinical settings. The objective of this study was to investigate the effects of ibutilide on the defibrillation threshold (DFT), restitution properties, dispersion of refractoriness and activation patterns during ventricular fibrillation (VF).

Methods  Ibutilide was administrated intravenously in six open-chest beagles. Before and after the drug administration, 20-second episodes of VF were electrically induced and recorded with a 10×10 unipolar electrode plaque sutured on the lateral epicardium of the left ventricle. DFT and VF activation patterns, including type of epicardial activation maps, VF cycle length (VF-CL), conduction velocity, wavelength (WL) and reentry incidence, were measured. Restitution properties and dispersion of refractoriness were estimated from activation recovery intervals (ARI) during pacing.

Results  Compared to baseline, ibutilide markedly decreased the DFT by 31% ((491±14) V vs. (337±59) V, P <0.01). The drug significantly reduced the maximal slope of the restitution curve (1.34±0.08 vs. 0.76±0.06, P <0.01) and its epicardial dispersion (0.36±0.09 vs. 0.21±0.06, coefficient of variation, P=0.03). The dispersion of refractoriness was enhanced at the pacing cycle length of 300 ms to 160 ms by ibutilide. The drug significantly increased the VF-CL ((96±19) ms vs. (112±20) ms, P <0.01) and the WL ((41±9) mm vs. (52±14) mm, P=0.02) during VF, and reduced the reentry incidence by 25% (0.08±0.02 vs. 0.06±0.02, P <0.01). In the epicardial activation maps, ibutilide significantly reduced the percentage of more complex activation maps during VF.

Conclusions  Intravenous ibutilide significantly decreased the DFT. It might be due to reduction of activation pattern complexity during VF.

     

Ibutilide decreases defibrillation threshold by the reduction of activation pattern complexity during ventricular fibrillation in canine hearts

Background  Ibutilide has been commonly used for pharmacologic cardioversion of atrial fibrillation and flutter in clinical settings The objective of this study was to investigate the effects of ibutilide on the defibrillation threshold (DFT), restitution properties, dispersion of refractoriness and activation patterns during ventricular fibrillation (VF).

Methods  Ibutilide was administrated intravenously in six open-chest beagles. Before and after the drug administration, 20-second episodes of VF were electrically induced and recorded with a 10×10 unipolar electrode plaque sutured on the lateral epicardium of the left ventricle. DFT and VF activation patterns, including type of epicardial activation maps, VF cycle length (VF-CL), conduction velocity, wavelength (WL) and reentry incidence, were measured. Restitution properties and dispersion of refractoriness were estimated from activation recovery intervals (ARI) during pacing.

Results  Compared to baseline, ibutilide markedly decreased the DFT by 31% ((491±14) V vs. (337±59) V, P<0.01). The drug significantly reduced the maximal slope of the restitution curve (1.34±0.08 vs. 0.76±0.06, P<0.01) and its epicardial dispersion (0.36±0.09 vs. 0.21±0.06, coefficient of variation, P=0.03). The dispersion of refractoriness was enhanced at the pacing cycle length of 300 ms to 160 ms by ibutilide. The drug significantly increased the VF-CL ((96±19) ms vs. (112±20) ms, P<0.01) and the WL ((41±9) mm vs. (52±14) mm, P=0.02) during VF, and reduced the reentry incidence by 25% (0.08±0.02 vs. 0.06±0.02, P<0.01). In the epicardial activation maps, ibutilide significantly reduced the percentage of more complex activation maps during VF.

Conclusions  Intravenous ibutilide significantly decreased the DFT. It might be due to reduction of activation pattern complexity during VF.

     

Effect of chronic intermittent hypoxia on theophylline metabolism in mouse liver

Background Chronic intermittent hypoxia (CIH) has been associated with abnormalities in the liver,which is the most important organ for drug metabolism.This study aimed to investigate the effect of CIH...     

Pure alumina bearings with cementless stems versus sandwich bearings with cemented stems in total hip arthroplasty

Background  Ceramic bearing surfaces have been introduced to prevent osteolysis after total hip arthroplasty (THA), but little is known about the difference in clinical and radiological results between pure alumina and sandwich alumina bearings. The purpose of this study was to analyze the results obtained with third-generation alumina-on-alumina THA with two different designs both in liner and femoral stem fixation after a minimum follow-up of 4.2 years.

Methods  The results of 195 primary alumina-on-alumina THAs in 167 patients were evaluated. The procedures were performed between January 1998 and October 2006. Three patients died and 11 patients were lost to follow-up, leaving a total of 153 patients (181 hips) available for study. In the 88 group A patients, 107 hips were implanted using pure alumina bearings with cementless femoral stems. These patients were followed for (6.84±1.49) years. In the 65 group B patients, 74 hips were implanted using sandwich alumina ceramic bearings with cemented femoral stems. These patients had a follow-up period of (7.73±1.60) years. Patients in both groups were evaluated clinically and radiographically.

Results  One ceramic liner fracture occurred in group A and five took place in group B (P <0.05), four of them revised for liner fracture. In each group, one acetabular shell migration happened without liner breakage and two hips developed deep infections, and all these six hips received revisions. Nine femoral components loosened in group B, with seven undergoing revisions. Kaplan-Meier survivorship at 5 years for revision of any component for any reason in group A was 96.26% compared to 90.54% in group B (P <0.05). Better function was determined in group A (average Harris hip scores: 92.13±2.85) than in group B (average Harris hip scores: 86.03±4.21) and the difference was significant (P <0.05). Squeaking was not recorded in either group.

Conclusions  The sandwich design of the acetabular bearings can not reduce the migration rate in ceramic bearings but increase the liner fracture rate compared to pure ceramic liners. The high loosening rate in fluted and taped designed cemented stems with sandwich liners warrant caution to their use.

     

Serum antibodies to 25 myelin oligodendrocyte glycoprotein epitopes in multiple sclerosis and neuromyelitis optica: clinical value for diagnosis and disease activity

Background  Whether antibody to myelin oligodendrocyte glycoprotein (MOG) can be a diagnostic marker for multiple sclerosis (MS) is still controversial. Recent studies suggested that serum specific anti-MOG epitope antibody might be an MS specific marker. However, these studies did not include neuromyelitis optica (NMO) which might be proven to also have anti-MOG antibody. Hence, the present study was undertaken to investigate the clinical value of serum antibodies to 25 MOG epitopes in conventional MS (CMS) and NMO.

Methods  Serum anti-MOG epitope IgG was detected in 61 CMS patients, 54 NMO patients, and 77 healthy controls, using enzyme-linked immunosorbent assay (ELISA).

Results  Anti-MOG_27-38 IgG levels in both CMS and NMO patients were significantly higher than that in healthy controls (optical density (OD): 0.64±0.38, 0.48±0.23 vs. 0.19±0.09; P=0.000). CMS and NMO patients in relapse stage had significantly higher anti-MOG_27-38 IgG level than patients in remission stage (OD: 0.55±0.14 vs. 0.24±0.09, P=0.027).

Conclusion  Although serum anti-MOG epitope IgG could not differentiate MS from NMO, it may be a useful marker for monitoring disease activity.

     

Endothelial progenitor cell down-regulation in a mouse model of Kawasaki disease

Background  Cardiovascular complications of Kawasaki disease (KD) are a common cause of heart disease in pediatric populations. Previous studies have suggested a role for endothelial progenitor cells (EPCs) in coronary artery lesions associated with KD. However, long-term observations of EPCs during the natural progression of this disorder are lacking. Using an experimental model of KD, we aimed to determine whether the coronary artery lesions are associated with down-regulation of EPCs.

Methods  To induce KD, C57BL/6 mice were administered an intraperitoneal injection of Lactobacillus casei cell wall extract (LCWE; phosphate buffered saline used as control vehicle). Study groups included: group A (14 days following LCWE injection), group B (56 days following LCWE injection) and group C (controls). Numbers of circulating EPCs (positively staining for both CD34 and Flk-1 while staining negative for CD45) were evaluated using flow cytometry. Bone marrow mononuclear cells were cultured in vitro to expand EPCs for functional analysis. In vitro EPC proliferation, adhesion and migration were assessed.

Results  The model was shown to exhibit similar coronary artery lesions to KD patients with coronary aneurysms. Numbers of circulating EPCs decreased significantly in the KD models (groups A and B) compared to controls ((0.017±0.008)% vs. (0.028±0.007)%, P <0.05 and (0.016±0.007)% vs. (0.028±0.007)%, P <0.05). Proliferative, adhesive and migratory properties of EPCs were markedly impaired in groups A and B.

Conclusion  Coronary artery lesions in KD occur as a consequence of impaired vascular injury repair, resulting from excess consumption of EPCs together with a functional impairment of bone marrow EPCs and their precursors.

     

Anteroapical aneurysm plication improves mechanical intraventricular dyssynchrony in patients with anterior myocardial infarction

Background  Left ventricular (LV) dyssynchrony has been described to occur in patients with myocardial infarction. Dyssynchrony of left ventricular mechanical contraction produces adverse hemodynamic consequences. This study aimed to test the capacity of geometric rebuilding by aneurysm plication to restore a more synchronous contractile pattern after a mechanical, rather than electrical, intervention.

Methods  A total of sixty patients with anterior myocardial infarction, QRS duration <120 ms, electively undergoing operation between January 2008 and January 2010 were included for analysis. Real-time 3-dimensional echocardiography was performed to assess LV function, LV systolic and diastolic dyssynchrony by measuring ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR) and LV dyssynchrony. LV dyssynchrony was defined as the systolic dyssynchrony of the time to reach the minimum systolic volume for 16 LV segments, expressed in percent cardiac cycle, systolic dyssynchrony index (SDI). We compared changes of LV dyssynchrony at different interval times.

Results  LV contraction was significantly asynchronous because preoperative SDI was higher, EF, PER and PFR were lowered. Compared with function after operation, LV mechanical intraventricular resynchronization was improved with decreased SDI ((8.7±0.5) % vs. (14.3±1.6) %, P=0.01); LV function was improved with EF increasing ((43±9)% vs. (37±7)%, P=0.001), and LV systolic and diastolic dyssynchrony was improved with more rapid PFR (199.4±15.6 vs. 148.4±21.2, P=0.002) and PER (212.4±14.5 vs. 156.3±26.2, P=0.001).

Conclusions  Systolic and diastolic dyssynchrony was highly prevalent in patients with aneurysm, irrespective of QRS duration. Aneurysm plication produces a mechanical intraventricular resynchronization.

     

Role of microRNA-181a in the apoptosis of tubular epithelial cell induced by cisplatin 

Background  Cisplatin (DDP) is one of most effective and most commonly used therapeutic agent in treating tumors, it can accumulate in the kidney and lead to acute renal failure. MicroRNA-181a can induce cell apoptosis by suppressing the expression of Bcl-2 family. In the present study, we investigated the role of microRNA-181a in the apoptosis of tubular epithelial cell induced by DDP.

Methods  HK-2 cells were cultured, transfected with microRNA-181a inhibitor for 48 hours, and stimulated with 50 µmol/L cisplatin for 24 hours. MicroRNA-181a expression was analyzed by real time PCR, and cell apoptosis was detected by flow cytometry. Moreover, Bcl-2 and Bcl-2-associated X protein (Bax) expression were measured by Western blotting.

Results  MicroRNA-181a expression significantly down-regulated in cells transfected with microRNA-181a inhibitor, compared with that in untransfectd cells (21.19±2.01 vs. 38.87±1.97, P <0.05). Cell apoptosis induced by DDP significantly decreased in cells transfected with MicroRNA-181a inhibitor. Compared with DDP treated cells alone, Bcl-2 expression strikingly was up-regulated and Bax expression was down-regulated in cells transfected with microRNA-181a inhibitor.

Conclusion  One pathway of DDP induces apoptosis of tubular epithelial cell by suppressing Bcl-2 expression is achieved by regulating the target gene of MicroRNA-181a.

     

Investigation of long-term implantation of BuMA stent in a porcine coronary model

Background  Stent-based delivery of sirolimus has been shown to reduce neointimal hyperplasia significantly. However, the long-term effect of the polymer is thought to initiate and sustain an inflammatory response and contribute to the occurrence of late complications. Our study aimed to evaluate the efficacy and safety of the BuMA biodegradable drug-coated sirolimus-eluting stent (BSES) for inhibiting neointimal hyperplasia in a porcine coronary model.

Methods  Four types of stents were implanted at random in different coronary arteries of the same pig: BSES (n=24), bare metal stent (BMS) (n=24), biodegradable polymer coated stent without drug (PCS) (n=24) and only poly (n-butyl methacrylate) base layer coated stent (EGS) (n=23). In total, 26 animals underwent successful random placement of 95 oversized stents in the coronary arteries. Coronary angiography was performed after 28 days, 90 days and 240 days of stent implantation. After 14 days, 28 days, 90 days and 240 days, 6 animals at each timepoint were sacrificed for histomorphologic analysis.

Results  The 28-day, 90-day and 240-day results of quantitative coronary angiography (QCA) showed reduction in luminal loss (LL) in the BSES group when compared with the BMS group;  (0.20±0.35) mm vs. (0.82±0.51) mm (P=0.035), (0.20±0.30) mm vs. (0.93±0.51) mm (P=0.013), and (0.18±0.16) mm vs. (0.19±0.24) mm (P=0.889), respectively. By 28-day, 90-day and 240-day histomorphomeric analysis results, there was also a corresponding significant reduction in neointimal tissue proliferation with similar injury scores of BSES compared with the BMS control; average neointimal area (0.90±0.49) mm² vs. (2.16±1.29) mm² (P=0.049), (1.53±0.84) mm² vs. (3.41±1.55) mm² (P=0.026), and (2.43±0.95) mm² vs. (3.12±1.16) mm² (P=0.228), respectively. High magnification histomorphologic examination revealed similar inflammation scores and endothelialization scores in both the BSES and BMS groups.

Conclusions  The BuMA biodegradable drug-coated sirolimus-eluting stents can significantly reduce neointimal hyperplasia and in-stent restenosis. Re-endothelialization of the BuMA stent is as good as that of the BMS in the porcine coronary model due to the reduced inflammation response to the BuMA stent.

     

Cigarette smoking increases levels of retinol-binding protein-4 in healthy men with normal glucose tolerance

Background  Smoking is related with insulin resistance and type 2 diabetes mellitus. Retinol-binding protein-4 is a new adipocytokine associated with insulin resistance. We investigated the serum levels of a series of adipocytokines including retinol-binding protein-4 in smokers and non-smokers to explore the possible roles of adipocytokines on smoking induced insulin resistance.

Methods  A total of 136 healthy male subjects (92 smokers and 44 non-smokers) with normal glucose tolerance were enrolled in the study. Adipocytokines including retinol-binding protein-4, visfatin, leptin, resistin, adiponectin were measured for the comparison between the two groups. Serum lipid profile, glucose, true insulin and proinsulin levels were measured as well in both groups. Food intake spectrum was also investigated.

Results  Both groups had similar profile of food consumption; visfatin, leptin, resistin and adiponectin, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, as well as blood pressure and body mass index, were similar in both groups. Triglycerides, retinol-binding protein-4 and homeostatic model assessment index for insulin resistance were higher in smoker group ((2.58±2.53) vs. (1.60±0.94) mmol/L, (26.05±8.50) vs. (21.83±8.40) µg/ml, and 2.25±2.08 vs. 1.58±1.15, respectively).

Conclusion  Smoking may have effect on insulin sensitivity, which is correlated with retinol-binding protein-4.

     

Safety and feasibility of repeated percutaneous transradial coronary intervention in the same route

Background  The radial approach has been increasingly used as an alternative to femoral access. And more procedures using repeated transradial coronary intervention (r-TRI) are performed. However, few data about r-TRI has been obtained. Therefore, we investigated the safety and feasibility of r-TRI using the same route.

Methods  A total of 423 consecutive eligible patients undergoing r-TRI were enrolled in the r-TRI group, and 846 patients with initial TRI (i-TRI) were assigned to the i-TRI group in a 2:1 matching ratio compared to r-TRI group. The primary endpoint included the success rate of the procedure and the incidence of vascular related complications.

Results  The baseline clinical characteristics in the two groups were comparable. The success rate of procedures in the r-TRI and i-TRI was similar (96.0% vs. 97.5%, P=0.130). In subgroup analysis (coronary angiography only or angiography with pecutaneous coronary intervention), similar results were also observed. The puncture numbers and incidence of radial artery spasm in the r-TRI group were significantly higher than in the i-TRI group (P=0.024 and P <0.001, respectively). The other procedural outcomes in the two groups were identical. With respect to the incidence of overall vascular related complication and independent events, there were no significant differences in spite of a higher incidence of radial artery occlusion (RAO) in the r-TRI group (RAO: 1.2% vs. 0.7%, P=0.521). The patients in the i-TRI group had more comfortable feeling than patients in the r-TRI group (P=0.001).

Conclusions  R-TRI produces a comparable procedure success rate and incidence of vascular complication when compared to i-TRI. It should be considered as an acceptable and safe procedure.

     

Proteomic analysis for detecting serum biomarkers related to smoking in humans

Background  Smoking is the leading cause of death in the world. This study focused on the difference of the serum proteomic profiling between healthy smokers and nonsmokers in order to find smoking-specific serum biomarkers.

Methods  Pattern-based proteomic profiling of 100 serum samples (from 50 Chinese male smokers and 50 matched nonsmokers) was performed through magnetic bead fractionation coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis (MALDI-TOF-MS) and resulting data were statistically analyzed by Ciphergen ProteinChip software 3.0.2.

Results  We found 72 serum peaks were significantly different between smokers and nonsmokers (P <0.05). Marker peaks of mass-to-charge ratio (m/z) 3159.13, 7561.03 and 9407.32 were smoking-specific.

Conclusion  The preliminary data suggested that smoking-specific serum biomarkers could be detected in humans.

     

Steady-state pharmacokinetics of zidovudine in Chinese HIV-infected patients

Background  The pharmacokinetics of zidovudine (AZT) are possibly influenced by weight, age, sex, liver and renal functions, severity of disease, and ethnicity. Currently, little information is available on the steady-state pharmacokinetics of AZT in Chinese HIV-infected patients. The current study aimed to characterize the steady-state pharmacokinetics of AZT in a Chinese set-up.

Methods  Eleven Chinese HIV-infected patients were involved in the steady-state pharmacokinetic study. In total, 300 mg of AZT, as a part of combination therapy, was given to patients, and serial blood samples were collected for 12 hours. The samples were measured by a high-performance liquid chromatography (HPLC) assay, and the results were analyzed by both the non-compartment model and the one-compartment model.

Results  The C_max of AZT in Chinese patients was higher than that in non-Asian patients. The half-life of AZT, analyzed by the non-compartment model (P=0.02), in male patients ((1.02±0.22) hours) was shorter than that of AZT in female patients ((1.55±0.29) hours). The AZT clearance, analyzed by the one-compartment model (P=0.045), in male patients ((262.60±28.13) L/h) was higher than that in female patients ((195.85±60.51) L/h).

Conclusion  The present study provides valuable information for the clinical practice of AZT-based highly active antiretroviral therapy in a Chinese set-up.

     

Ultrasound facilitates identification of combined spinal-epidural puncture in obese parturients

Background  The palpation method is widely used in clinical practice to identify the puncture site of combined spinal-epidural (CSE) blocks, but it is usually difficult to accurately locate the puncture site in obese parturients. Accurate identification of the puncture site is crucial for successful CSE block. The objective of this study was to evaluate the impact of ultrasound imaging on the success rate of CSE puncture in obese parturients.

Methods  Sixty obese parturients with a body mass index ³30 kg/m² who were scheduled for caesarean section were randomized into two equal-sized groups for location of the puncture site: an ultrasound group and a palpation group. The success rate of puncture at the first puncture site, the number of puncture attempts, duration of CSE procedure, time taken to determine the puncture site, and the depth of the epidural space were compared between groups. The frequencies of complications such as puncture site hemorrhage, neurological damage, and inadvertent dural puncture were also studied.

Results  There were no differences in age, body weight, height, body mass index, or gestational age between the two groups. The success rate of puncture at the first puncture site was significantly higher in the ultrasound group than the palpation group (100.00% vs. 70.00%, P=0.004). The number of puncture attempts was significantly lower in the ultrasound group than the palpation group (c²=6.708, P=0.035). The time taken for determining the puncture site was (0.30±0.12) minutes in the palpation group and (2.60±0.61) minutes in the ultrasound group (P <0.001). The duration of CSE procedure was (7.67±1.52) minutes in the palpation group and (9.37±1.35) minutes in the ultrasound group (P <0.001). The depth of the epidural space was similar in both groups (P=0.586). Puncture site hemorrhage was observed in 6 (20.00%) patients in the palpation group and 2 (6.67%) patients in the ultrasound group (P=0.255).

Conclusions  Ultrasound imaging improves the rate of successful puncture at the first puncture site and decreases the number of puncture attempts. It facilitates CSE puncture in obese parturients.

     

Epicardial radiofrequency ablation for left ventricular aneurysm related ventricular arrhythmias during off-pump coronary artery bypass surgery

Background  Left ventricular aneurysm (LVA) is one of the serious complications after acute myocardial infarction. We attempted to evaluate the preliminary efficacy of LVA repair combined with epicardial radiofrequency ablation for ventricular arrhythmia during off-pump coronary artery bypass grafting (OPCAB).

Methods  From June 2009 to April 2011, 31 patients with LVA had angina symptoms and ventricular arrhythmia. In all patients, circular and cross-shaped radiofrequency epicardial ablations were performed using unipolar ablation pen along the border between the aneurysm wall and normal cardiac tissue and in the central zone of the aneurysms, followed by a linear placation of ventricular aneurysms on beating heart.

Results  All the patients showed complete recovery. The average number of grafted vessels was 2.7±1.3. Intraoperative examinations revealed that the ventricular arrhythmia was effectively controlled by radiofrequency ablation. All cases had been followed up for one year. Holter monitoring revealed a significant reduction in ventricular arrhythmias (P <0.05). Echocardiography showed significant increase in left ventricular ejection fraction (P <0.05) and decrease in left ventricular end-diastolic diameter (P <0.05).

Conclusions  For patients with ventricular aneurysm and preoperative malignant arrhythmia, aneurysm repair plus epicardial radiofrequency ablation in OPCAB was found to be an effective and feasible therapeutic technique. However, medium- to long-term therapeutic efficacy of this method remains to be determined by future studies and observations.

     

Protective effect of low potassium dextran solution on acute kidney injury following acute lung injury induced by oleic acid in piglets

Background  Low potassium dextran (LPD) solution can attenuate acute lung injury (ALI). However, LPD solution for treating acute kidney injury secondary to ALI has not been reported. The present study was performed to examine the renoprotective effect of LPD solution in ALI induced by oleic acid (OA) in piglets.

Methods  Twelve animals that suffered an ALI induced by administration of OA into the right atrium were divided into two groups: the placebo group (n=6) pretreated with normal saline and the LPD group (n=6), pretreated with LPD solution. LPD solution was injected intravenously at a dose of 12.5 ml/kg via the auricular vein 1 hour before OA injection.

Results  All animals survived the experiments with mild histopathological injury to the kidney. There were no significant differences in mean arterial pressure (MAP), creatinin and renal damage scores between the two groups. Compared with the placebo group, the LPD group had better gas exchange parameters at most of the observation points ((347.0±12.6) mmHg vs. (284.3±11.3) mmHg at 6 hours after ALI, P <0.01). After 6 hours of treatment with OA, the plasma concentrations of NGAL and interleukin (IL)-6 in both groups increased dramatically compared to baseline ((6.0±0.6) and (2.50±0.08) folds in placebo group; and (2.5±0.5) and (1.40±0.05) folds in LPD group), but the change of both parameters in the LPD group was significantly lower (P <0.01) than in the placebo group. And 6 hours after ALI the kidney tissue concentration of IL-6 in the LPD group ((165.7 ± 22.5) pg∙ml^-1∙g^-1 protein) was significantly lower (P <0.01) than that in placebo group ((67.2± 25.3) pg∙ml^-1∙g^-1 protein).

Conclusion  These findings suggest that pretreatment with LPD solution via systemic administration might attenuate acute kidney injury and the cytokine response of IL-6 in the ALI piglet model induced by OA injection.

     

Effects of partial portal vein arterialization on liver regeneration after hepatectomy in minipigs with obstructive jaundice

Background  Hilar cholangiocarcinoma is a malignant tumor that is difficult to cure. BACKGROUNDThe aim of this study was to observe the effects of flow-controlled partial portal vein arterializations (PPVA) on liver regeneration after hepatectomy in minipigs with chronic obstructive jaundice.

Methods  Eight minipigs were made into chronic obstructive jaundice models. United semi-hepatectomy, which imitates extended radical surgery for treatment of hilar cholangiocarcinoma, was then performed. The eight minipigs were randomly divided into groups A and B (n=4 minipigs each). PPVA was performed in Group A but not in Group B. The effects of flow-controlled PPVA on live regeneration after hepatectomy were observed for 30 days after hepatectomy.

Results  The portal vein PO₂ at the immediate time point and on postoperative day 30 was higher in Group A ((47.33±2.43) and (48.50±4.44) mmHg) than in Group B ((35.38±4.06) and (35.55±2.55) mmHg respectively, all P <0.01). The mitotic index of liver cells on postoperative days 14 and 21 was higher in Group A (12.55%±2.85% and 15.25%±1.99% respectively) than in Group B (6.85%±2.10% and 11.88%±1.15% respectively, all P <0.05). The regeneration rate of residual liver on postoperative days 14 and 21 was higher in Group A (24.56%±6.15% and 70.63%±9.83% respectively) than in Group B (11.96%±5.43% and 44.92%±7.42% respectively, P <0.05 and P <0.01 respectively).

Conclusion  Flow-controlled PPVA can promote liver regeneration after hepatectomy and prevent liver failure in minipigs with chronic obstructive jaundice.