Antigen clearance at the peak of the primary immune response induces experimental autoimmune encephalomyelitis.

Autoimmune demyelinating diseases can be induced by an immune response against myelin peptides; however, the exact mechanism underlying the development of such diseases remains unclear. In experimental autoimmune encephalomyelitis, we found that the clearance of exogenous myelin antigen at the peak of the primary immune response is key to the pathogenesis of the disease. The generation of effector T cells requires continuous antigen stimulation, whereas redundant antigen traps and exhausts effector T cells in the periphery, which induces resistance to the disease. Moreover, insufficient antigenic stimulation fails to induce disease efficiently owing to insufficient numbers of effector T cells. When myelin antigen is entirely cleared, the number of effector T cells reaches a peak, which facilitates infiltration of more effector T cells into the central nervous system. The peripheral antigen clearance initiates the first wave of effector T cell entry into the central nervous system and induces chronic inflammation. The inflamed central nervous system recruits the second wave of effector T cells that worsen inflammation, resulting in loss of self-tolerance. These findings provide new insights into the mechanism underlying the development of autoimmune demyelinating diseases, which may potentially impact future treatments.

Preclinical evaluation of the fluid dynamics and hemocompatibility of the Corheart 6 left ventricular assist device.

BACKGROUND: Corheart 6 (Corheart) is a newly developed magnetically levitated continuous-flow left ventricular assist device currently undergoing multicenter clinical trials in China. Featuring a small size, minimal weight, and low power consumption, the Corheart aims to improve pump hemocompatibility, reduce adverse events, and enhance the quality of life of heart failure patients. METHODS: Computational simulations assessed flow field, shear stress, and washout, while in vitro and in vivo experiments were performed to further demonstrate hemocompatibility. RESULTS: Numerical results show that the flow path in the Corheart blood pump is well designed. There is no significantly high shear stress in the majority of the flow domain. Short secondary flow paths and small pump size (small priming volume) provide good washing (0.049 and 0.165 s to remove 55% and 95% old blood, respectively), allowing low hemolysis levels both in computational and in vitro hemolysis tests (in vitro hemolysis index ranges from 0.00092 ± 0.00006 g/100 L to 0.00134 ± 0.00019 g/100 L). Good hemocompatibility was further evidenced by ten 60-day sheep implants tested with relatively low flow rates of 2.0 ± 0.2 L/min; the results showed no hemolysis or thrombosis. CONCLUSIONS: Numerical and experimental results shed light on the fluid dynamics characteristics and hemocompatibility of the Corheart. It is believed that the Corheart will provide more promising possibilities for minimally invasive implantation techniques and for those patients with a small body surface area.

Fast Automatic Registration of UAV Images via Bidirectional Matching.

Image registration plays a vital role in the mosaic process of multiple UAV (Unmanned Aerial Vehicle) images acquired from different spatial positions of the same scene. Aimed at the problem that many fast registration methods cannot provide both high speed and accuracy simultaneously for UAV visible light images, this work proposes a novel registration framework based on a popular baseline registration algorithm, ORB-the Oriented FAST (Features from Accelerated Segment Test) and Rotated BRIEF (Binary Robust Independent Elemental Features) algorithm. First, the ORB algorithm is utilized to extract image feature points fast. On this basis, two bidirectional matching strategies are presented to match obtained feature points. Then, the PROSRC (Progressive Sample Consensus) algorithm is applied to remove false matches. Finally, the experiments are carried out on UAV image pairs about different scenes including urban, road, building, farmland, and forest. Compared with the original version and other state-of-the-art registration methods, the bi-matching ORB algorithm exhibits higher accuracy and faster speed without any training or prior knowledge. Meanwhile, its complexity is quite low for on-board realization.

30-day in vivo study of a fully maglev extracorporeal ventricular assist device.

OBJECTIVE: Cardiogenic shock (CS) often occurs in patients suffering from rapidly progressing end-stage heart failure or acute myocardial infarction. Mechanical circulatory support may be used for patients who do not respond to medication or revascularization to stabilize hemodynamics. Extracorporeal ventricular assist device (Extra-VAD) has been reported to be successful for patients with cardiogenic shock. This study aimed to evaluate the 30-day in-vivo performance and safety of a newly developed Extra-VAD with maglev centrifugal pump technology, MoyoAssist®. METHOD: The study was conducted with 6 healthy ovine models, weighing 43.2 ~ 59.6 kg. Cannulation was performed with a 34 Fr venous cannula surgically connected to the left arterial appendage and a 24 Fr arterial cannula inserted into descending aorta. The pump flow rate was maintained at 2 ~ 3 L/min to provide sufficient cardiac support without suction. Activated clotting time was maintained within the range of 150 ~ 250 s. RESULTS: No device-related adverse events occurred throughout the study. Plasma-free hemoglobin results were within the acceptable range of ventricular assist device therapy (<40 mg/dl). MGS01 had an anticoagulation management related bleeding event and was terminated on day 29. All other sheep's biochemical test results were stable. The autopsy showed no embolism or thrombus formation and no end-organ damage. CONCLUSION: This study demonstrated that the MoyoAssist® Extra-VAD is able to provide cardiac support effectively and safely and may provide a new alternative choice for patients with CS in China.

GDF11 prevents the formation of thoracic aortic dissection in mice: Promotion of contractile transition of aortic SMCs.

Thoracic aortic dissection (TAD) is an aortic disease associated with dysregulated extracellular matrix composition and de-differentiation of vascular smooth muscle cells (SMCs). Growth Differentiation Factor 11 (GDF11) is a member of transforming growth factor ß (TGF-ß) superfamily associated with cardiovascular diseases. The present study attempted to investigate the expression of GDF11 in TAD and its effects on aortic SMC phenotype transition. GDF11 level was found lower in the ascending thoracic aortas of TAD patients than healthy aortas. The mouse model of TAD was established by ß-aminopropionitrile monofumarate (BAPN) combined with angiotensin II (Ang II). The expression of GDF11 was also decreased in thoracic aortic tissues accompanied with increased inflammation, arteriectasis and elastin degradation in TAD mice. Administration of GDF11 mitigated these aortic lesions and improved the survival rate of mice. Exogenous GDF11 and adeno-associated virus type 2 (AAV-2)-mediated GDF11 overexpression increased the expression of contractile proteins including ACTA2, SM22α and myosin heavy chain 11 (MYH11) and decreased synthetic markers including osteopontin and fibronectin 1 (FN1), indicating that GDF11 might inhibit SMC phenotype transition and maintain its contractile state. Moreover, GDF11 inhibited the production of matrix metalloproteinase (MMP)-2, 3, 9 in aortic SMCs. The canonical TGF-ß (Smad2/3) signalling was enhanced by GDF11, while its inhibition suppressed the inhibitory effects of GDF11 on SMC de-differentiation and MMP production in vitro. Therefore, we demonstrate that GDF11 may contribute to TAD alleviation via inhibiting inflammation and MMP activity, and promoting the transition of aortic SMCs towards a contractile phenotype, which provides a therapeutic target for TAD.

Extracorporeal Respiratory Support With a Miniature Integrated Pediatric Pump-Lung Device in an Acute Ovine Respiratory Failure Model.

Respiratory failure is one of the major causes of mortality and morbidity all over the world. Therapeutic options to treat respiratory failure remain limited. The objective of this study was to evaluate the gas transfer performance of a newly developed miniature portable integrated pediatric pump-lung device (PediPL) with small membrane surface for respiratory support in an acute ovine respiratory failure model. The respiratory failure was created in six adult sheep using intravenous anesthesia and reduced mechanical ventilation at 2 breaths/min. The PediPL device was surgically implanted and evaluated for respiratory support in a venovenous configuration between the right atrium and pulmonary artery. The hemodynamics and respiratory status of the animals during support with the device gas transfer performance of the PediPL were studied for 4 h. The animals exhibited respiratory failure 30 min after mechanical ventilation was reduced to 2 breaths/min, indicated by low oxygen partial pressure, low oxygen saturation, and elevated carbon dioxide in arterial blood. The failure was reversed by establishing respiratory support with the PediPL after 30 min. The rates of O2 transfer and CO2 removal of the PediPL were 86.8 and 139.1 mL/min, respectively. The results demonstrated that the PediPL (miniature integrated pump-oxygenator) has the potential to provide respiratory support as a novel treatment for both hypoxia and hypercarbia. The compact size of the PediPL could allow portability and potentially be used in many emergency settings to rescue patients suffering acute lung injury.

Effects of Cardiopulmonary Support With a Novel Pediatric Pump-Lung in a 30-Day Ovine Animal Model.

The scarcity of donor organs has led to the development of devices that provide optimal long-term respiratory or cardiopulmonary support to bridge recipients as they wait for lung and/or heart transplantation. This study was designed to evaluate the 30-day in vivo performance of the newly developed pediatric pump-lung (PediPL) for cardiopulmonary support using a juvenile sheep model. The PediPL device was placed surgically between the right atrium and descending aorta in eight sheep (25.4-31.2 kg) and evaluated for 30 days. Anticoagulation was maintained with continuous heparin infusion (activated clotting time 150-200 s). The flow rate was measured continually, and gas transfer was measured daily. Plasma free hemoglobin, platelet activation, hematologic data, and blood biochemistry were assessed twice a week. Sheep were euthanized after 30 days. The explanted devices were examined for gross thrombosis. Six sheep survived for 30-32 days. During the study, the oxygen transfer rate of the devices was 54.9 ± 13.2 mL/min at a mean flow rate of 1.14 ± 0.46 L/min with blood oxygen saturation of 95.4% ± 1.7%. Plasma free hemoglobin was 8.2 ± 3.7 mg/dL. Platelet activation was 5.35 ± 2.65%. The animals had normal organ chemistries except for surgery-related transient alterations in kidney and liver function. Although we found some scattered thrombi on the membrane surfaces of some explanted devices during the necropsy, the device function and performance did not degrade. The PediPL device was capable of providing cardiopulmonary support with long-term reliability and good biocompatibility over the 30-day duration and offers the potential option for bridging pediatric patients with end-stage heart or lung disease to heart and/or lung transplantation.

Increased expression of pigment epithelium-derived factor in aged mesenchymal stem cells impairs their therapeutic efficacy for attenuating myocardial infarction injury.

AIMS: Mesenchymal stem cells (MSCs) can ameliorate myocardial infarction (MI) injury. However, older-donor MSCs seem less efficacious than those from younger donors, and the contributing underlying mechanisms remain unknown. Here, we determine how age-related expression of pigment epithelium-derived factor (PEDF) affects MSC therapeutic efficacy for MI. METHODS AND RESULTS: Reverse transcriptase-polymerized chain reaction  and enzyme-linked immunosorbent assay analyses revealed dramatically increased PEDF expression in MSCs from old mice compared to young mice. Morphological and functional experiments demonstrated significantly impaired old MSC therapeutic efficacy compared with young MSCs in treatment of mice subjected to MI. Immunofluorescent staining demonstrated that administration of old MSCs compared with young MSCs resulted in an infarct region containing fewer endothelial cells, vascular smooth muscle cells, and macrophages, but more fibroblasts. Pigment epithelium-derived factor overexpression in young MSCs impaired the beneficial effects against MI injury, and induced cellular profile changes in the infarct region similar to administration of old MSCs. Knocking down PEDF expression in old MSCs improved MSC therapeutic efficacy, and induced a cellular profile similar to young MSCs administration. Studies in vitro showed that PEDF secreted by MSCs regulated the proliferation and migration of cardiac fibroblasts. CONCLUSIONS: This is the first evidence that paracrine factor PEDF plays critical role in the regulatory effects of MSCs against MI injury. Furthermore, the impaired therapeutic ability of aged MSCs is predominantly caused by increased PEDF secretion. These findings indicate PEDF as a promising novel genetic modification target for improving aged MSC therapeutic efficacy.

Experimental observation on a new chimney-shaped mechanical valve completely implanted above the mitral annulus in animals.

Current commercially available prosthetic valves suffer from limited size, high requirements for implantation technique, subvalvular structural destruction, and valve dysfunction due to proliferation of fibrous endothelial tissue. This study aims to perform the preclinical large animal experiments for surgically implanting a chimney-shaped artificial mechanical heart valve with zero left ventricular occupancy, which fully accommodates the movement of the valve leaflets in the valve frame and realizes completely supra-annular surgical implantation. A total of 7 sheep underwent the replacement of artificial valve, and 5 sheep survived normally until anatomical examination. The mechanical properties of these artificial mitral valves remain functionally normal. There was no obvious thromboembolism around the artificial valve and in the important organs. The tissue layer of suture ring was completely organized and endothelialized, and the thickness of tissue layer was about 0.6-1.0 mm. The follow-up of echocardiography showed that the left ventricular ejection fraction was normal (60-70%) before and 6 months after operation. The results of transvalvular pressure gradient and blood flow velocity of artificial valve were normal. Left ventricular retrograde angiography showed that the artificial valve was completely located in the left atrium with good position and normal opening and closing. There was no obvious perivalvular leakage and other abnormalities. At 3 and 6 months, there were no obvious abnormalities in blood routine test, liver and kidney function, and other indexes. The new chimney-shaped artificial mechanical valve implanted completely above the mitral annulus had good wear resistance, histocompatibility, and antithrombotic and hemodynamic performance.

Ex vivo lung evaluation of prearrest heparinization in donation after cardiac death.

OBJECTIVE: To evaluate the effects of prearrest heparin administration on lung quality in a model of donation after cardiac death (DCD), and to assess the potential application of ex vivo lung perfusion (EVLP) in the identification of better grafts from the DCD donor pool. METHODS: Cardiac death was induced by electric shock in 10 pigs. One group received a prearrest heparin dose of 300 units/kg (H group, n = 5) and the other did not (NH group, n = 5). Animals remained at room temperature for 1 hour without ventilation, defining the warm ischemic time. After harvest, the lungs underwent 6 hours of cold ischemia before being evaluated with EVLP for 4 hours. RESULTS: Static compliance 28 ± 3 versus 29 ± 2 (Cstat-cm H2O), pulmonary vascular resistance (PVR) 593 ± 127 versus 495 ± 70 (PVR-dyn·s/cm), and oxygenation 327 ± 32 versus 330 ± 28 (ΔPO2-mm Hg) remained stable from the beginning until the end of EVLP in the H group. In the NH group, Cstat started to decline after the first hour (25 ± 2 vs 21 ± 2), ΔPO2 after hour 2 (265 ± 44 vs 207 ± 44), and PVR started to increase after hour 3 (765 ± 132 vs 916 ± 168). Significant differences between the groups were observed at the end of EVLP (P < 0.001). Parameters of lung quality after EVLP also showed significant differences between the groups: wet weight-to-dry weight ratio (P < 0.001), protein in the bronchial lavage (P < 0.01), Na + K-ATPase activity (P < 0.001), and E-selectin (P < 0.001) in the perfusate. CONCLUSIONS: Prearrest heparin administration improved organ function by preserving endothelial homeostasis. EVLP proved to be a useful platform for assessing DCD lungs, providing reliable means of discriminating injured grafts.

Prophylactic amiodarone and lidocaine improve survival in an ovine model of large size myocardial infarction.

BACKGROUND: Large animal models serve as a critical link in the translation of basic science to clinical practice. However, large animal models of myocardial infarction (MI), especially large size MI, have been associated with high mortality because of arrhythmia. The prophylactic effect of amiodarone and lidocaine were retrospectively reviewed in our ovine MI model. MATERIALS AND METHODS: A total of 114 Dorset hybrid sheep with 25%-30% MI were included in the present study. The sheep were prophylactically treated with amiodarone plus lidocaine before ligation of the four to six coronary artery branches supplying the apex of the heart (arrhythmia prevention [AP] group, n = 45) and with epinephrine (shock prevention [SP] group, n = 49), respectively. The sheep without prophylactic treatment (no prevention [NP] group, n = 20) were used as the control group. The incidence of arrhythmia requiring treatment, mortality due to arrhythmia, hemodynamics, and arterial blood gas values during surgery were analyzed in these three groups. RESULTS: No significant difference was found in infarct size among the three groups. The incidence of arrhythmia requiring treatment was significantly decreased in the AP group compared with that in the NP or SP groups (4.4% for AP versus 35% for NP and 45% for SP groups; P < 0.05). The mortality due to lethal arrhythmia was 2.2% in the AP group, significantly lower than that in the NP group (15%) or SP group (18.4%). Other than the heart rate, no significant differences were found in the hemodynamic data between the AP and NP groups. Metabolic acidosis was not observed in any group, as indicated by the pH and lactate values. CONCLUSIONS: Prophylactic amiodarone plus lidocaine decreased the mortality due to lethal arrhythmia after acute MI in our sheep model without significant negative effects on the hemodynamics. However, epinephrine improved the hemodynamics but also increased the mortality due to lethal arrhythmia. Thus, prophylactic amiodarone plus lidocaine is recommended to improve the stability in a large MI animal model.

Biocompatibility assessment of a long-term wearable artificial pump-lung in sheep.

The purpose of this study was to assess the biocompatibility of a newly developed long-term wearable artificial pump-lung (APL) in a clinically relevant ovine animal model. The wearable APL device was implanted in five sheep through left thoracotomy. The device was connected between the right atrium and pulmonary artery and evaluated for 30 days. Three sheep were used as the sham control. Platelet activation was assessed by measuring platelet surface P-selectin (CD62P) expression with flow cytometry and plasma soluble P-selectin with an enzyme-linked immunosorbent assay. Thrombotic deposition on the device components and hollow fiber membranes were analyzed with digital imaging and scanning electron microscopy. Surface P-selectin of the APL and sham groups changed significantly over the study period, but without significant differences between the two groups. Soluble P-selectin for the two groups peaked in the first 24 h after the surgery. Soluble P-selectin of the APL group remained slightly elevated over the study period compared to the presurgical baseline value and was slightly higher compared to that of the sham group. Plasma free hemoglobin remained in the normal ranges in all the animals. In spite of the surgery-related alteration in laboratory tests and elevation of platelet activation status, the APL devices in all the animals functioned normally (oxygen transfer and blood pumping) during the 30-day study period. The device flow path and membrane surface were free of gross thrombus. Electron microscopy images showed only scattered thrombi on the fibers (membrane surface and weft). In summary, the APL exhibited excellent biocompatibility. Two forms of platelet activation, surgery-related and device-induced, in the animals implanted with the wearable APL were observed. The limited device-induced platelet activation did not cause gross thrombosis and impair the long-term device performance.

Runx3 suppresses gastric cancer metastasis through inactivation of MMP9 by upregulation of TIMP-1.

Recent studies have suggested that loss of RUNX3 expression is involved with gastric tumor metastasis. However, the precise mechanism of RUNX3-mediated suppression of tumor metastasis remains elusive. We aimed to clarify the effect of RUNX3 on tumor metastasis in gastric cancer cell lines and tumors. Immunohistochemistry revealed that RUNX3 was significantly decreased in metastatic gastric cancer. Gelatin zymography and Western blot showed that instead of regulating matrix metalloproteinase 9 (MMP9) expression, RUNX3 expression inhibited MMP9 enzyme activity, and this was consistent with the upregulation of tissue inhibitor of metalloproteinases 1 (TIMP1) by RUNX3. TIMP1 siRNA treatment impaired RUNX3-mediated suppression of gastric cancer cell invasion. Reporter assays demonstrated regulation of TIMP-1 by RUNX3. Two RUNX3 binding sites were identified in the TIMP-1 promoter and direct interaction of RUNX3 with the TIMP-1 promoter was confirmed in vitro and in vivo. These findings provide evidence for RUNX3-mediated suppression of gastric cancer invasion and metastasis and define a novel molecular mechanism that for the metastasis-inhibiting activity of RUNX3. These data may be applied in the development of RUNX3 for gastric cancer metastasis diagnostics and therapeutics.

Downregulation of adiponectin induced by tumor necrosis factor α is involved in the aggravation of posttraumatic myocardial ischemia/reperfusion injury.

OBJECTIVE: Recent clinical observations have indicated that nonlethal mechanical trauma significantly increases myocardial infarction risk even in the presence of completely normal coronary arteries. We investigated the molecular mechanisms responsible for exacerbation of ischemic myocardial injury after nonlethal mechanical trauma with a special focus on the role of tumor necrosis factor α and its potential downstream effector adiponectin, a novel adipokine with anti-inflammatory and cardioprotective properties. DESIGN: Laboratory study. SETTING: University research unit. SUBJECTS: Male adult adiponectin knockout mice and wild-type mice. INTERVENTIONS: The animals were subjected to nonlethal mechanical trauma using the Noble-Collip drum (40 rpm ± 5 mins) followed by myocardial ischemia/reperfusion injury 7 days posttrauma. We also investigated the effects of neutralizing tumor necrosis factor α with etanercept and exogenous adiponectin supplementation on ischemic myocardial injury after trauma. MEASUREMENTS AND MAIN RESULTS: Trauma significantly sensitized myocardium to ischemia/reperfusion injury as evidenced by increased apoptosis, enlarged infarct size, and decreased cardiac function. Plasma adiponectin concentrations were reduced after traumatic injury (the nadir occurring 3 days posttrauma), an effect abrogated by etanercept-mediated tumor necrosis factor α blockade. The downregulation of adiponectin was accompanied by increased myocardial superoxide and nitric oxide generation and peroxynitrite formation. Both etanercept and exogenous adiponectin supplementation (on day 3 posttrauma or 10 mins before reperfusion on day 7 posttrauma) markedly inhibited oxidative/nitrative stress and ischemia/reperfusion injury in posttraumatic ischemic/reperfused hearts of wild-type mice, whereas only adiponectin supplementation (but not tumor necrosis factor α inhibition) substantially attenuated posttraumatic ischemia/reperfusion injury in adiponectin knockout mice. CONCLUSIONS: Tumor necrosis factor α-induced downregulation of adiponectin and the resultant enhanced oxidative/nitrative stress are involved in exacerbated posttraumatic ischemic myocardial injury. Therapeutic approaches blocking tumor necrosis factor α production or restoring adiponectin might have prophylactic value against secondary myocardial ischemic injury after a primary nonlethal mechanical trauma.

Effect of High Suspension and Low Incision Surgery Based on Traditional Ligation of Chinese Medicine in Treatment of Mixed Haemorrhoids: A Multi-centre, Randomized, Single-Blind, Non-inferiority Clinical Trial.

OBJECTIVE: To observe the clinical effect of high suspension and low incision (HSLI) surgery on mixed haemorrhoids, compared with Milligan-Morgan haemorrhoidectomy. METHODS: A multi-centre, randomized, single-blind, non-inferiority clinical trial was performed. Participants with mixed haemorrhoids from Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing Rectum Hospital, Air Force Medical Center of People's Liberation Army of China, and Puyang Hospital of Traditional Chinese Medicine were enrolled from September 2016 to March 2018. By using a blocked randomization scheme, participants were assigned to two groups. The experimental group was treated with HSLI, while the control group was treated with Milligan-Morgan haemorrhoidectomy. The primary outcome was the clinical effect evaluated at 12 weeks after operation. The secondary outcomes included the number of haemorrhoids treated during the operation, pain scores, use of analgesics, postoperative oedema, wound healing, incidence of anal stenosis, anorectal manometry after operation, as well as surgical duration, length of stay and total hospitalization expenses. A safety evaluation was also conducted. RESULTS: In total, 246 eligible participants were enrolled, with 123 cases in each group. There was no significant difference in the clinical effect between the two groups (100.00% vs. 99.19%, P>0.05). Compared with the control group, the number of external haemorrhoids treated during the operation and the pain scores after operation were significantly reduced in the experimental group (P<0.05 or P<0.01); the patient number with wound healing at 2 weeks after operation and the functional length of anal canal at 12 weeks after operation were significantly increased in the experimental group (P<0.05). There was no significant difference in the incidence of anal stenosis, the numbers of patients using analgesics and patients with postoperative oedema between the two groups after operation (P>0.05). The surgical duration and length of stay in the experimental group were significantly longer than those in the control group, and the total hospitalization expense was significantly higher than that in the control group (all P<0.05). No adverse events were reported in either group during the whole trial or follow-up period. CONCLUSION: HSLI had the advantages of preserving the skin of anal canal completely, alleviating postsurgical pain and promoting rapid recovery after operation. (Registration No. ChiCTR1900022883).

Proteomic profiling of human bone marrow mesenchymal stem cells under shear stress.

Mesenchymal stem cells (MSCs) are promising seed cells for tissue engineering of blood vessels. As seed cells, MSCs must endure blood fluid shear stress after transplantation. It has been shown that fluid shear stress can regulate the proliferation and differentiation of MSCs. However, the effects of fluid shear stress on MSCs including the types of proteins modulated are still not well understood. In this study, we exposed human mesenchymal stem cells (HMSCs) to 3 dyn/cm(2) shear stress for 6 h and compared them to a control group using proteomic analysis. Thirteen specific proteins were affected by shear stress, 10 of which were up-regulated. Shear stress especially induced sustained increases in the expression of Annexin A2 and GAPDH, which have been specifically shown to affect HMSCs function. We present here the first comparative proteome analysis of effect of shear stress on HMSCs.

[Enhancement of proliferation and differentiation of bone mesenchymal stem cells by basic fibrous growth factor controlled release nanoparticles].

This research was carried out to investigate the effect of basic fibrous growth factor (bFGF) controlled release hydrogel nanoparticles on the proliferation and differentiation of mesenchymal stem cells. The dex-GMA-bFGF-NPs were prepared by an improved emulsion polymerization method; their morphology, size and encapsulated ratio were assessed by routine procedure. Dynamic dialysis method was used to determine the release characteristics of dex-GMA-bFGF-NPs in vitro. The secondary culture MSCs were divided into four groups according the different ingredients being added into the DMEM culture medium: free bFGF group (A), blank dex-GMA nanoparticles group (B), dex-GMA-bFGF nanoparticles group (C), nothing group (D). The proliferation of cultured MSCs was measured by using cell counting method, MTT method and flow cytometry. ALP kit was used to evaluate the ALP activity of the MSCs to show the differentiation of the cells by adding the dex-GMA-bFGF-NPs to the DMEM culture medium (C group) or bFGF only (A group). B group and D group were taken as the controls. The results were analyzed by statistical analysis software (SPSS11.0). All results showed that the shape of dex-GMA-bFGF-NPs was spherical. The encapsulated ratio was 88% and more than 85% of the encapsulated bFGF could be released during 14 days. The in vitro cellular study showed the control release of bFGF from nanoparticles could promote the proliferation of MSCs. After 12 days, the cell number in groups A, B and C was (21.97 +/- 0.25) x 10(4) cells/ml, (12.43 +/- 0.13) x 10(4) cells/ml, (27.45 +/- 0.78) x 10(4) cells/ml and (12.03 +/- 0.43) x 10(4) cells/ml, with the difference being statistically significant among them (P < 0.05). The flow cytometry revealed that the G2/M+S percentage in group C was the highest at 4-8 days after plate culture(P < 0.05). During the first 3 days, the proliferation and differentiation of BMSCs between group A and group B were of no significance (P > 0.05), but were much faster than those of group C and D. After 7 days, dex-GMA-bFGF-NPs could enhance BMSCs proliferation and differentiation continually, but bFGF had no enhancement any more, the difference between group A and group B became more significant (P < 0.05). So we made the conclusions the bFGF loading dex-GMA hydrogel nanoparticles can release bFGF more than 21 days and can promote the proliferation and differentiation of the BMSCs through a long period of controlled release of bFGF. Dex-GMA-bFGF-NPs may be an ideal controlled release carrier for bioactive growth factors.

[Oridonin ameliorates experimental autoimmune encephalomyelitis by inhibiting NF-κB signaling in T lymphocytes].

Objective To investigate the therapeutic effect and mechanism of oridonin on experimental autoimmune encephalomyelitis (EAE). Methods Female C57BL/6 mice were immunized with MOG/CFA to establish EAE model. The mice were randomly divided into EAE control and oridonin treatment groups. The mice were intraperitoneally injected with oridonin [15 mg/(kg.d)] on day 3, 5 and 7 post immunization, and the control group was injected with the same amount of PBS. EAE scores were recorded and the cell infiltration in the spinal cord was observed by HE staining at the peak of the disease. Flow cytometry analysis was used to detect the proliferation and apoptosis of MOG reactive CD4+ T cells, and the differentiation of pathogenic T helper type 1 (Th1) cells and Th17 cells. The expression of cytokine IFN-γ and IL-17 were detected by ELISA assay. The expression of nuclear factor κBp65 (NF-κBp65), phosphorylated NF-κBp65 (p-NF-κBp65), and phosphorylated IκB (p-IκB) were detected by Western blot analysis. Results Compared with the control group, the incidence and severity of EAE mice in the oridonin-treated groups was reduced, the onset time was delayed, and the immune cell infiltration in the spinal cord was reduced. In vitro and in vivo experiments showed that oridonin inhibited the proliferation of myelin antigen reactive CD4+ T cells and induced their apoptosis. Oridonin inhibited the differentiation of pathogenic Th1 cells and Th17 cells, and the expression of inflammatory cytokines IFN-γ and IL-17. Oridonin inhibited the phosphorylation of IκB and NF-κBp65. Conclusion Oridonin can ameliorate EAE by inhibiting the activation of NF-κB signaling pathway, thereby the proliferation and differentiation of T cells and the secretion of inflammatory factors are inhibited.

Effectiveness of a novel, completely biomaterial valved pulmonary arterial conduit: An in vivo study.

As a pre-clinical assessment, the present study aimed to investigate the safety and effectiveness of a novel valved pulmonary arterial conduit constructed entirely from biomaterials by transplanting it in the outflow tract of the right ventricle in sheep. Under extracorporeal circulation, the valved pulmonary arterial conduit was used to replace the pulmonary artery of sheep with a beating heart. The performance was assessed at 30, 90 and 180 days post-surgery. Hemodynamic and structural changes were evaluated, and safety was assessed after 180 postoperative days. The hemodynamic effect and biosafety of the implant were further evaluated by observing the changes in various pressure indicators of the heart, echocardiographic results, anatomical and pathological examination results, liver and kidney functions, routine blood tests, a blood coagulation test, and other test results following implantation of the purely biotic valved conduit. The conduit was successfully implanted in 12 sheep and no mortality occurred postoperatively. During the 180-day follow-up, there was no obvious stenosis or regurgitation of the right ventricular outflow tract and pulmonary valve after valved conduit implantation. The findings of autopsy, pathology and laboratory examinations were unremarkable. The implantation of this biosynthetic vascular graft into animals meets the safety and effectiveness requirements for clinical application. This pulmonary arterial conduit has potential clinical application for children with complex congenital heart disease who require pulmonary artery reconstruction to achieve a radical cure.

Glutaraldehyde and 2,3-butanediol treatment of bovine pericardium for aortic valve bioprosthesis in sheep: a preliminary study.

BACKGROUND: Bovine pericardium can be used for cardiovascular repair surgeries, but challenges involving biocompatibility and durability remain. This study aimed to carry out pre-clinical testing of aortic valve replacement using an aortic valve prosthesis made of bovine pericardium modified with glutaraldehyde (GA) and 2,3-butanediol (BD). METHODS: The mechanical, plasma protein adsorption, platelet adhesion, collagenase digestion, and ninhydrin properties of the material (control vs. GA vs. GA + BD) were tested. All 3 tissues were implanted in rats and observed after 8 weeks under microscopy with alizarin red staining for calcification. Aortic valves made from the fully-treated material were implanted in sheep. A commercial bioprosthesis was used as control. Effectiveness and safety indicators were observed at 180 days after implantation. RESULTS: Compared with the control group, the GA + BD material showed higher elongation at breaking and tensile load (both P<0.05), lower plasma protein adsorption, lower platelet adhesion, lower collagenase digestion, lower ninhydrin value, and higher cross-linking (all P<0.05). After implantation in rat models, the GA + BD material showed little or no dissolution; there was no obvious calcification; and it was surrounded by a small amount of fibrosis, with peripheral capillary proliferation. After implantation in sheep models, the aortic valve leaflets of the experimental animals freely opened and closed, their surface was smooth, and no abnormal echo was observed. The echocardiographic results and hemodynamic were comparable between the two groups. All safety parameters were normal. CONCLUSIONS: Modification of bovine pericardium with GA and BD results in a biomaterial with favorable properties for use as an aortic valve prosthesis.