Checkpoint Kinase 1 Stimulates Endogenous Cardiomyocyte Renewal and Cardiac Repair by Binding to Pyruvate Kinase Isoform M2 C-Domain and Activating Cardiac Metabolic Reprogramming in a Porcine Model of Myocardial Ischemia/Reperfusion Injury.

BACKGROUND: The regenerative capacity of the adult mammalian hearts is limited. Numerous studies have explored mechanisms of adult cardiomyocyte cell-cycle withdrawal. This translational study evaluated the effects and underlying mechanism of rhCHK1 (recombinant human checkpoint kinase 1) on the survival and proliferation of cardiomyocyte and myocardial repair after ischemia/reperfusion injury in swine. METHODS AND RESULTS: Intramyocardial injection of rhCHK1 protein (1 mg/kg) encapsulated in hydrogel stimulated cardiomyocyte proliferation and reduced cardiac inflammation response at 3 days after ischemia/reperfusion injury, improved cardiac function and attenuated ventricular remodeling, and reduced the infarct area at 28 days after ischemia/reperfusion injury. Mechanistically, multiomics sequencing analysis demonstrated enrichment of glycolysis and mTOR (mammalian target of rapamycin) pathways after rhCHK1 treatment. Co-Immunoprecipitation (Co-IP) experiments and protein docking prediction showed that CHK1 (checkpoint kinase 1) directly bound to and activated the Serine 37 (S37) and Tyrosine 105 (Y105) sites of PKM2 (pyruvate kinase isoform M2) to promote metabolic reprogramming. We further constructed plasmids that knocked out different CHK1 and PKM2 amino acid domains and transfected them into Human Embryonic Kidney 293T (HEK293T) cells for CO-IP experiments. Results showed that the 1-265 domain of CHK1 directly binds to the 157-400 amino acids of PKM2. Furthermore, hiPSC-CM (human iPS cell-derived cardiomyocyte) in vitro and in vivo experiments both demonstrated that CHK1 stimulated cardiomyocytes renewal and cardiac repair by activating PKM2 C-domain-mediated cardiac metabolic reprogramming. CONCLUSIONS: This study demonstrates that the 1-265 amino acid domain of CHK1 binds to the 157-400 domain of PKM2 and activates PKM2-mediated metabolic reprogramming to promote cardiomyocyte proliferation and myocardial repair after ischemia/reperfusion injury in adult pigs.

Improved methodology for efficient establishment of the myocardial ischemia-reperfusion model in pigs through the median thoracic incision.

To investigate the feasibility and effectiveness of establishing porcine ischemia-reperfusion models by ligating the left anterior descending (LAD) coronary artery, we first randomly divided 16 male Bama pigs into a sham group and a model group. After anesthesia, we separated the arteries and veins. Subsequently, we rapidly located the LAD coronary artery at the beginning of its first diagonal branch through a mid-chest incision. Then, we loosened and released the ligation line after five minutes of pre-occlusion. Finally, we ligated the LAD coronary artery in situ two minutes later and loosened the ligature 60 min after ischemia. Compared with the sham group, electrocardiogram showed multiple continuous lead ST-segment elevations, and ultrasound cardiogram showed significantly lower ejection fraction and left ventricular fractional shortening at one hour and seven days post-operation in the model group. Twenty-four hours after the operation, cardiac troponin T and creatine kinase-MB isoenzyme levels significantly increased in the model group, compared with the sham group. Hematoxylin and eosin staining showed the presence of many inflammatory cells infiltrating the interstitium of the myocardium in the model group but not in the sham group. Masson staining revealed a significant increase in infarct size in the ischemia/reperfusion group. All eight pigs in the model group recovered with normal sinus heart rates, and the survival rate was 100%. In conclusion, the method can provide an accurate and stable large animal model for preclinical research on ischemia/reperfusion with a high success rate and homogeneity of the myocardial infarction area.

High-Sensitivity Cardiac Troponin T in Prediction and Diagnosis of Early Postoperative Hypoxemia after Off-Pump Coronary Artery Bypass Grafting.

To investigate the relationship of preoperative high-sensitivity cardiac troponin T (hs-cTnT) with early postoperative hypoxemia (EPH) following off-pump coronary artery bypass grafting (OPCAB). Records of patients undergoing OPCAB between 2018 and 2022 were reviewed. Baseline characteristics and postoperative arterial blood gas analysis were derived from the cardiovascular surgery electronic medical records. Preoperative hs-cTnT levels were measured routinely in all patients. Logistic regression analyses were performed to test the association of preoperative hs-cTnT with EPH. A total of 318 OPCAB patients were included, who had a preoperative hs-cTnT test available for review. Before surgery, 198 patients (62%) had a rise in hs-cTnT level (≥14 ng/L) and 127 patients (40%) had a more severe hs-cTnT level (≥25 ng/L). The preoperative hs-cTnT level was associated with EPH (odds ratio per ng/L, 1.86; 95% confidence interval 1.30−2.68; p < 0.001), prolonged intensive care unit stay (odds ratio, 1.58; 95% confidence interval 1.08−2.32; p = 0.019), and delayed extubating time (odds ratio, 1.63; 95% confidence interval 1.15−2.34; p = 0.007). On multivariable analysis, adjusted for BMI, hypertension, smoking status, serum creatinine, and cardiac function, preoperative hs-cTnT remained an independent factor associated with EPH. Elevation of hs-cTnT concentrations are significantly associated with EPH after OPCAB. Review of presurgical hs-cTnT concentration may help identify patients who would benefit from OPCAB to improve surgical risk assessment.

IDH1 Promotes Foam Cell Formation by Aggravating Macrophage Ferroptosis.

A distinctive feature of ferroptosis is intracellular iron accumulation and the impairment of antioxidant capacity, resulting in a lethal accumulation of lipid peroxides leading to cell death. This study was conducted to determine whether inhibiting isocitrate dehydrogenase 1 (IDH1) may help to prevent foam cell formation by reducing oxidized low-density lipoprotein (ox-LDL)-induced ferroptosis in macrophages and activating nuclear factor erythroid 2-related factor 2 (NRF2). Gene expression profiling (GSE70126 and GSE70619) revealed 21 significantly different genes, and subsequent bioinformatics research revealed that ferroptosis and IDH1 play essential roles in foam cell production. We also confirmed that ox-LDL elevates macrophage ferroptosis and IDH1 protein levels considerably as compared with controls. Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, reduced ox-LDL-induced elevated Fe2+ levels, lipid peroxidation (LPO) buildup, lactate dehydrogenase (LDH) buildup, glutathione (GSH) depletion, glutathione peroxidase 4 (GPX4), ferritin heavy polypeptide 1 (FTH1), and solute carrier family 7 member 11 (SLC7A11) protein downregulation. More crucially, inhibiting IDH1 reduced Fe2+ overload, lipid peroxidation, LDH, and glutathione depletion, and elevated GPX4, FTH1, and SLC7A11 protein expression, resulting in a reduction in ox-LDL-induced macrophage ferroptosis. IDH1 inhibition suppressed ox-LDL-induced macrophage damage and apoptosis while raising NRF2 protein levels. We have demonstrated that inhibiting IDH1 reduces ox-LDL-induced ferroptosis and foam cell formation in macrophages, implying that IDH1 may be an important molecule regulating foam cell formation and may be a promising molecular target for the treatment of atherosclerosis.

Unsupervised machine learning reveals epicardial adipose tissue subtypes with distinct atrial fibrosis profiles in patients with persistent atrial fibrillation: A prospective 2-center cohort study.

BACKGROUND: Epicardial adipose tissue (EAT) accumulation is associated with the progression of atrial fibrillation. However, the histological features of EATs are poorly defined and their correlation with atrial fibrosis is unclear. OBJECTIVE: The purpose of this study was to identify and characterize EAT subgroups in the persistent atrial fibrillation (PeAF) cohorts. METHODS: EATs and the corresponding left atrial appendage samples were obtained from patients with PeAF via surgical intervention. Adipocyte markers, that is, Uncoupling Protein 1, Transcription Factor 21, and CD137, were examined. On the basis of expression of adipocyte markers, patients with PeAF were categorized into subgroups by using unsupervised clustering analysis. Clinical characteristics, histological analyses, and outcomes were subsequently compared across the clusters. External validation was performed in a validation cohort. RESULTS: The ranking of feature importance revealed that the 3 adipocyte markers were the most relevant factors for atrial fibrosis compared with other clinical indicators. On the k-medoids analysis, patients with PeAF could be categorized into 3 clusters in the discovery cohort. The histological studies revealed that patients in cluster 1 exhibited statistically larger size of adipocytes in EATs and severe atrial fibrosis in left atrial appendages. Findings were replicated in the validation cohort, where severe atrial fibrosis was noted in cluster 1. Moreover, in the validation cohort, there was a high degree of overlap between the supervised classification results and the unsupervised cluster results from the k-medoids method. CONCLUSION: Machine learning-based cluster analysis could identify subtypes of patients with PeAF having distinct atrial fibrosis profiles. Additionally, EAT whitening (increased proportion of white adipocytes) may be involved in the process of atrial fibrosis.

Rutin Inhibits Ox-LDL-Mediated Macrophage Inflammation and Foam Cell Formation by Inducing Autophagy and Modulating PI3K/ATK Signaling.

Atherosclerosis (AS) is one of the leading causes of death among the elderly, and is primarily caused by foam cell generation and macrophage inflammation. Rutin is an anti-inflammatory, anti-oxidant, anti-allergic, and antiviral flavonoid molecule, known to have anti-atherosclerotic and autophagy-inducing properties, but its biological mechanism remains poorly understood. In this study, we uncovered that rutin could suppress the generation of inflammatory factors and reactive oxygen species (ROS) in ox-LDL-induced M2 macrophages and enhance their polarization. Moreover, rutin could decrease foam cell production, as shown by oil red O staining. In addition, rutin could increase the number of autophagosomes and the LC3II/I ratio, while lowering p62 expression. Furthermore, rutin could significantly inhibit the PI3K/ATK signaling pathway. In summary, rutin inhibits ox-LDL-mediated macrophage inflammation and foam cell formation by inducing autophagy and modulating PI3K/ATK signaling, showing potential in treating atherosclerosis.

Exceptional points enhance sum sideband generation in a mechanical PT-symmetric system.

Systems exhibiting parity-time (PT) symmetry are, in general, non-Hermitian systems, in which exceptional points (EPs) emerge when the system transits from the PT-symmetric phase to the broken-PT-symmetric phase. Based on the abnormal exponential amplification effect in EPs, it is often used to generate, control and transmit light in non-Hermitian systems. In this paper, we theoretically analyze the generation of the frequency components at the sum sideband by considering the nonlinear terms of the optomechanical dynamics in a double-probe-field-driven mechanical PT-symmetric system. Using experimentally achievable parameters, we demonstrate that the efficiency of sum sideband generation (SSG) can be significantly enhanced in EPs, even that the efficiency of SSG can be raised by three orders of magnitude compared to the general optomechanical system by adjusting the appropriate system parameters. These results are beneficial to explore the transmission and conversion of light in chip-scale optical communications.

Performance Assessment of Asphalt Mixture Produced with a Bio-Based Binder.

Nowadays, the growing energy costs and pressing worldwide demand for petroleum-based products create a strong need to develop alternative binders deriving from green and renewable sources. Bio-binders (or bitumen added to bio-based materials) can potentially be a viable alternative for the production of bituminous mixture, promoting the circular economy as well as environmental sustainability principles without reducing the overall performance of the mixture. In this context, the current study focuses on evaluation of the effects of a bio-binder on the mechanical response of asphalt concrete (AC) produced with it. In particular, a 10% bio-oil deriving from a by-product of the paper industry has been blended with a conventional 50/70 penetration grade bitumen to obtain the bio-binder. Moreover, plain bitumen having the same consistency was chosen to produce a reference AC. Two dense-graded AC wearing courses were prepared in the laboratory according to Italian technical specifications. A mechanical characterization in terms of indirect tensile strength, indirect tensile stiffness modulus, fatigue response and permanent deformation resistance was performed on gyratory compacted specimens using both conventional and performance tests. In addition, aging and water sensitivity of the AC specimens were evaluated. Overall results highlight that the AC produced with the bio-binder did not show reduced mechanical properties and it was comparable to the reference AC regardless of aging and water conditioning. This highly encourages the use of bio-binder as a viable alternative in asphalt technology.

[Influencing Factors of Ozone Concentration in Xi'an Based on Generalized Additive Models].

Based on the ozone monitoring data from 2014 to 2018, we presented the variation of ozone concentration in Xi'an and revealed the effects of ozone concentration by meteorological factors based on the generalized additive model (GAM). The results showed that ① with increasing ozone concentration year by year, the assessment standard of ozone pollution was overtaken by three consecutive years since 2016. However, the rising trend was slowed down since 2017 as a result of the strengthened pollution control during summer. ② The monthly curve of ozone concentration was presented as a reversed "V" model with a rising trend accompanying the rising temperature from January to July and a decreasing one during the rest of the year, peaking in July in terms of average monthly ozone concentration. However, this model would turn into an "M" in years with high precipitation when the valley witnessed the highest precipitation in a month. ③ The ozone pollution increased from the year 2014 to 2018 with a stretch-forward ozone polluted time. Furthermore, the rates of ozone non-attainment increased from 1.9% in 2014 to 14% in 2018. In addition, the time ozone pollution emerged advanced from July to May. ④ Based on the GAM model, ozone concentration was non-colinearly related to temperature, air pressure, sunshine duration, and relative humidity. However, the curves of these factors varied considerably, with a positive influence of temperature and sunshine duration and a negative influence of air pressure and relative humidity. The influence of precipitation was mainly witnessed in summers, while no influence of wind was observed. Furthermore, ozone pollution can be easily triggered under the following conditions:temperature>24℃, air pressure <962 hPa, sunshine duration>9 h, and a relative humidity 36%-65% with no rain.

Evaluation of Graphite Nanoplatelets Influence on the Lubrication Properties of Asphalt Binders.

With the major advance in nanotechnology, there has been an emerging interest in applying nanoscale materials to asphalt pavement materials. Among them, considerable interest has been directed to carbon-based nanomaterials, such as carbon nanotubes (CNTs) and graphite nanoplatelets (GNPs). Recent studies have proven that the addition of small percentages of GNPs could significantly reduce the compaction effort required to densify HMA. Viscosity measurements showed, however, that the addition of GNPs increased the viscosity of the binder. This observation pointed towards the presence of a different mechanism responsible for the reduction of compaction effort. A new test method used for lubricants and based on tribology has been recently proposed in order to characterize the lubricating behaviour of asphalt binders. In this study, the tribological characterization of an asphalt binder modified with GNPs was performed. A novel approach in which aggregate surface microtexture was simulated using rough surfaces of the testing fixtures, shows that indeed, the addition of GNPs lowers the friction coefficient and therefore, enhances the lubrication properties of the binder when mixed with mineral aggregates.

Analysis of Fatigue and Healing Properties of Conventional Bitumen and Bio-Binder for Road Pavements.

The analysis of fatigue behavior of bituminous binders is a complex issue due to several time-temperature dependent phenomena which interact simultaneously, such as damage accumulation, viscoelasticity, thixotropy, and healing. The present research involves rheological measurements aimed at evaluating the fatigue behavior and compares the self-healing capability of two plain bitumen and a bio-binder obtained by partially replacing one of the plain bitumen with a renewable bio-oil. Healing potential was assessed by means of an experimental approach previously implemented for modified bitumen and bituminous mastic and based on the use of a dynamic shear rheometer (DSR). The effects of some variables such as bitumen type, bio-oil addition, and aging on the healing potential of binders were taken into account. Results showed that the above-mentioned method for healing analysis is also suitable for conventional and bio-add binders. Outcomes of the experimental investigation highlight that fatigue and self-healing are mainly dependent on binder consistency and also affected by aging. Finally, the addition of bio-oil may induce even better performances in terms of healing potential compared to conventional bitumen, especially in aged condition.

Generation and enhancement of sum sideband in a quadratically coupled optomechanical system with parametric interactions.

We investigate theoretically the generation and enhancement of sum sideband in a quadratically coupled optomechanical system with parametric interactions. It is shown that the generation of frequency components at the sum sideband stems from the nonlinear optomechanical interactions via two-phonon processes in the quadratically coupled optomechanical system, while an optical parametric amplifier (OPA) inside the system can considerably improve the sum sideband generation (SSG). The dependence of SSG on the system parameters, including the power of the control field, the frequency detuning of the probe fields and the nonlinear gain of OPA are analyzed in detail. Our analytic calculation indicates that the SSG can be obtained even under weak driven fields and greatly enhanced via meeting the matching conditions. The effect of SSG may have potential applications for achieving measurement of electric charge (or other weak forces) with higher precision and on-chip manipulation of light propagation.

Inhibition of microRNA­939 suppresses the development of human non­small cell lung cancer via the upregulation of tissue inhibitor of metalloproteinases 2.

Numerous microRNAs (miRNA/miRs) have been reported to be associated with the initiation and progression of non­small cell lung cancer (NSCLC). The aim of the present study was to examine the expression and biological role of miR­939 in human NSCLC, in vitro. Reverse transcription­quantitative polymerase chain reaction analysis was used to evaluate the expression of miR­939 in NSCLC tissues. Cell Counting Kit­8, 5­ethynyl­29­deoxyuridine and Transwell assays were also used to determine the effects of miR­939 on tumor cell proliferation and invasion in two human NSCLC cell lines (H1299 and SPCA1). Furthermore, tissue inhibitor of metalloproteinases 2 (TIMP2) was confirmed to be a target of miR­939 by luciferase reporter assay, western blotting and bioinformatics analysis. Following downregulation of miR­939 expression, cell proliferative and invasive abilities were significantly suppressed. Collectively, these findings indicated that the knockdown of miR­939 may inhibit cell proliferation and invasion by regulating the expression of TIMP2 in NSCLC cells. Thus, miR­939 may be a potential target in the treatment of NSCLC, although this requires further investigation.

Biomechanical characterization of a novel ring connector for sutureless aortic anastomosis.

The surgical treatment for aortic diseases remains a challenge for any cardiac surgeon. The use of sutureless ring connector in aortic anastomosis can simplify the procedure and shorten anastomosis time. Therefore, we developed a novel device for sutureless aortic anastomosis. A series of experiments were carried out for tensile and leakproof-capacity assessments to verify the feasibility of the ring connector by using fresh swine aorta samples. In in vivo test, the ring connector was implanted in 6 swine with follow-up of 6 months. Radiographic and pathological studies of the aorta were performed. In the tensile tests, the strength was 32.7±5.9 Newton (N) in the sutureless anastomosis group, compared with 73.3±12.5 N in the control group by traditional manual suture. In the leakproof-capacity assessment, no sign of either leakage or bursting was evident at 280 mmHg of internal pressure in the aorta samples. In in vivo tests, it took 9.47±0.3 minutes for the sutureless anastomosis, compared with 15.58±1.39 minutes for hand-sewn suturing. Insertion was easy and rapid. Radiographic and pathological studies were performed at first month, third month and sixth month after surgery, each time obtained from the two swine, showed patency of the anastomosis and no signs of stenosis, blood leakage, migration or pseudoaneurysm formation, except one paralyzed swine developed of thrombo-occlusion at the site of the sutureless anastomosis. The result indicates that this novel ring connector offers considerable promise for sutureless aortic anastomosis.

Simultaneous resection of left atrial myxoma and esophageal carcinoma via right thoraco-abdominal approach.

Concomitant occurrence of atrial myxoma and esophageal carcinoma is an extremely rare entity. Here we present two cases of synchronously suffered left atrial myxoma and esophageal carcinoma. Both patients underwent simultaneous resection of two tumors via the right thoraco-abdominal approach and recovered well.

Long-term clinical outcome of intensity-modulated radiation therapy for locally advanced esophageal squamous cell carcinoma.

PURPOSE: This study evaluated the effectiveness and safety of intensity-modulated radiation therapy (IMRT) for locally advanced esophageal squamous cell carcinoma (ESCC). METHODS: Between August 2009 and December 2011, 112 patients with pathologically confirmed ESCC treated with IMRT at Jiangsu Province People's Hospital and Nantong Tumor Hospital were included in a retrospective analysis. Patients received either IMRT alone (group A) or concurrent chemoradiotherapy (CRT) (group B). A radiation dose of 60-66 Gy administered in 30-33 fractions was delivered to the tumor. The patients in group B simultaneously received 2 cycles of cisplatin-based doublets with either 5-fluorouracil or taxotere. The Kaplan-Meier method was used to compute the survival time. Early and late toxicities were scored according to CTCAE v.3.0. RESULTS: The response rate of group B (91.07%) was not significantly greater than that of group A (89.29%) (χ2 = 0.10, p = 0.75). The 1- and 3-year survival rates of group B (87.5% and 57.14%, respectively) were greater than those of group A (69.64% and 37.50%, respectively). The difference in overall survival was statistically significant between groups A and B (χ2 = 5.30, p = 0.02; χ2 = 4.33, p = 0.04). Hematological toxicity, gastrointestinal toxicity, and treatment-related esophagitis were significantly higher in group B than group A (16.07% vs. 33.93%, p = 0.04; 10.71% vs. 26.79%, p = 0.03; 19.64% vs. 44.64%, p = 0.01). However, intergroup differences in terms of late toxicity were not significant. CONCLUSIONS: IMRT was a practical and feasible technique to treat ESCC. Concurrent CRT could increase local tumor control and long-term survival. The CRT regimen was associated with a higher incidence of acute gastrointestinal and hematological toxicity.

[Clinical value of B ultrasonography in the diagnosis of transient synovitis of hip in dogs].

OBJECTIVE: To investigate the value of B ultrasonography in the early diagnosis of transient synovitis of hip (TSH) in dogs, and provide the valid base and data for the clinic early diagnosis of TSH. METHODS: Eighty 2-3 month old dogs were injected 0.2% noradrenalin (NA) into the hip joint induced TSH. We observed 5 assessments that included the 99mTC-MDP triphasic imaging, X ray, B ultrasonography, the synovial fluid and the pathological tissue check in different time. RESULTS: Early course of TSH presented the synovium of joint hemangiectasis, hyperaemia, synovium villus hyperplasia, edema, and joint inflammatory exudation. The ischemia of local blood supply of the femoral head was observed by 99mTC-MDP triphasic imaging. Ultrasonography showed the broadening of the anterior space of the hip, but the X ray showed no valid changes. CONCLUSION: B ultrasonography can report the early changes of TSH and may be used in the early diagnosis of TSH in children.

Surgical outcome of esophageal tuberculosis secondary to mediastinal lymphadenitis in adults: experience from single center in China.

OBJECTIVE: Esophageal tuberculosis (ET) is a rare disorder often easily misdiagnosed. The aim of this study is to evaluate the clinical features and to highlight the surgical role in treatment and complication management for undiagnosed ET. METHODS: Between June 2006 and June 2011, six esophageal tuberculosis cases were retrospectively reviewed for their clinical presentations, radiological findings, endoscopic views, surgical treatment and outcome. RESULTS: The prevalent rate of ET was 0.30%. All patients, aged from 28 to 71 years, presented with dysphagia in six, weight loss in four, and each of retrosternal pain, epigastric pain, fever with cough in one. The duration ranged from two weeks to two months. Involvement of esophagus observed at middle segment in five patients, and at lower segment in one. Endoscopy demonstrated diverticulum with polyps in one patient, ulcer formation in one, and extraneous compression with intact mucosa in four. Five patients underwent video-assisted thoracoscopic surgery (VATS) and one was performed thoracotomy perforation repair for esophagopleural fistula. Diagnoses of all cases were confirmed by histopathological examination and acid-fast bacilli culture. Drug sensitivity test revealed multidrugs resistant mycobacterium tuberculous in one case. All patients discharged and recovered by antituberculous treatment with follow-up time ranged from 12 to 45 months. CONCLUSIONS: ET should be considered as a causative factor for dysphagia. Surgery should be applied in undiagnosed ET. VATS is useful in improving rate of confirmative diagnosis, and relieving symptom of dysphagia. Thoracotomy repair is reserved for complications of ET.

The influence of deep hypothermic global brain ischemia on EEG in a new rat model.

OBJECTIVES: Neurological complications following deep hypothermic circulatory arrest (DHCA) occur between t 4% ≈ 25%. However, the cerebral injury mechanisms are still not well understood due to a lack of a practical and simple animal model. We aimed to establish a rodent deep hypothermic global brain ischemia (DHGBI) model, which can be used to elucidate these mechanisms in future studies. DESIGN: 30 Sprague-Dawley rats were divided randomly into three groups: the carotid occlusion DHGBI group, the internal carotid shunt DHGBI group, and the sham operation group. We validated the model in terms of electroencephalogram (EEG) and regional cerebral blood flow (rCBF). All rats were sacrificed for analysis of brain moisture capacity after 24 hours. RESULTS: In the internal carotid shunt DHGBI group the EEG activity was suppressed to "flat-line" and the relative power of the α and θ frequency bands was decreased (p < 0.05). However, in the carotid occlusion DHGBI group we only observed the relative power of the α frequency band depressed (p < 0.05). The rCBF was significantly decreased in all groups. In the internal carotid shunt DHGBI group the rCBF was significantly reduced to 4.27 ± 2.75%, and was lower than the other two groups (p < 0.05). The result of brain moisture capacity was consistent with the EEG and rCBF observations. CONCLUSIONS: The current study presents a novel cerebral recovery model of DHCA in the rat. This experimental model may be suitable to further elucidate the mechanisms associated with adverse cerebral outcomes after DHCA and to investigate potential neuroprotective strategies.

[Biocompatibility of polylactic-co-glycolic acid for culturing bFGF gene-transfected bone marrow stromal cells and application of the cell complex for repairing rabbit cartilage defect].

OBJECTIVE: To evaluate the biocompatibility of polylactic-co-glycolic acid (PLGA) for culturing bFGF gene-transfected bone marrow stromal cells (BMSCs) and assess the feasibility of this cell complex for repairing cartilage defect in rabbits using tissue engineering method. METHODS: BMSCs transfected by bFGF gene were cultured on PLGA matrix to assess the biocompatibility of PLGA. The cell complex was then implanted into the cartilage defect in rabbits, and its effect in cartilage defect repair was evaluated by histological observation and immunohistochemical staining. RESULTS: BMSCs transfected by bFGF gene grew normally on PLGA matrix. After implantation, the complex showed good effect for cartilage defect repair in rabbits. CONCLUSION: PLGA has good biocompatibility with the transfected BMSCs, and the cell complex can be used for repairing rabbit cartilage defect and may potentially serve as a substitute of cartilage autograft.