Photo-methanification of aquatic dissolved organic matters with different origins under aerobic conditions: Non-negligible role of hydroxyl radicals.

Lingering inconsistencies in the global methane (CH4) budget and ambiguity in CH4 sources and sinks triggered efforts to identify new CH4 formation pathways in natural ecosystems. Herein, we reported a novel mechanism of light-induced generation of hydroxyl radicals (•OH) that drove the production of CH4 from aquatic dissolved organic matters (DOMs) under ambient conditions. A total of five DOM samples with different origins were applied to examine their potential in photo-methanification production under aerobic conditions, presenting a wide range of CH4 production rates from 3.57 × 10-3 to 5.90 × 10-2 nmol CH4 mg-C-1 h-1. Experiments of •OH generator and scavenger indicated that the contribution of •OH to photo-methanificaiton among different DOM samples reached about 4∼42 %. In addition, Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry showed that the carbohydrate- and lipid-like substances containing nitrogen-bonded methyl groups, methyl ester, acetyl groups, and ketones, were the potential precursors for light-induced CH4 production. Based on the experimental results and simulated calculations, the contribution of photo-methanification of aquatic DOMs to the diffusive CH4 flux across the water-air interface in a typical eutrophic shallow lake (e.g., Lake Chaohu) ranged from 0.1 % to 18.3 %. This study provides a new perspective on the pathways of CH4 formation in aquatic ecosystems and a deeper understanding on the sources and sinks of global CH4.

Storages and leaching losses of soil water dissolved CO2 and N2O on typical land use hillslopes in southeastern hilly area of China.

The dynamics of soil water dissolved CO2 and N2O are important in determining the fates of soil CO2 and N2O. However, related mechanisms and processes have been rarely revealed. In this study, storages and leaching losses of soil water dissolved CO2 and N2O were investigated on the tea garden (TG) and bamboo forest (BF) hillslopes. Soil water storage and leaching flux were simulated by the HYDRUS-3D model and the soil water dissolved CO2 and N2O concentrations were acquired by field monitoring. Results showed that the storages of soil water dissolved CO2 and N2O ranged from 1.30 to 14.86 kg C ha-1 and 0.24 to 388.99 g N ha-1 on the TG hillslope, respectively, while they ranged from 0.49 to 52.29 kg C ha-1 and 0.50 to 14.22 g N ha-1 on the BF hillslope, respectively. The annual leaching loss of soil water dissolved CO2 and N2O were 26.17 kg C ha-1 and 29.46 g N ha-1, respectively, on the TG hillslope, while they were 49.51 kg C ha-1 and 4.35 g N ha-1 on the BF hillslope, respectively. The dissolved CO2 leaching loss mainly occurred in summer, especially in July on both hillslopes. Peaks of dissolved N2O leaching loss on the TG hillslope were observed after the application of basal fertilizer, accompanying with precipitation events. Instead, peaks of dissolved N2O leaching loss on the BF hillslope were observed in summer. The main influencing factors of dissolved CO2 and N2O storages were temperature, precipitation, and fertilization, with total effects generally >0.30. However, that of the dissolved CO2 and N2O leaching losses was the precipitation, with total effects >0.57. Dissolved CO2/N2O concentration was more important than soil water storage in determining the dissolved CO2/N2O storage, while the leaching flow rate was more crucial than dissolved CO2/N2O concentration in determining the dissolved CO2/N2O leaching loss. These findings expanded our knowledge of sources and sinks of greenhouse gases on the terrestrial ecosystem.

HSP90AA1 promotes the inflammation in human gingival fibroblasts induced by Porphyromonas gingivalis lipopolysaccharide via regulating of autophagy.

BACKGROUND: Peri-implantitis of tooth seriously affects the life quality of patients. This study aimed to investigate the role of HSP90AA1 in the inflammatory of human gingival fibroblasts (HGFs) induced by porphyromonas gingivalis lipopolysaccharide (Pg-LPS), and to provide a potential therapeutic target for clinical treatment of peri-implantitis. METHODS: Pg-LPS (0.1, 1, 10 µg/mL) was used to construct the inflammatory model of HGFs to evaluate the effect of Pg-LPS on HGFs. Then HSP90AA1-siRNA was transfected to construct HSP90AA1 low expression HGFs cell line, and 3-MA was also added. After that, cell viability, apoptosis, the contents of inflammatory cytokines were detected by CCK-8, flow cytometry and ELISA assay, respectively. Intracellular ROS, the expressions of HSP90α, HSP90ß were detected by immunofluorescence. The levels of HSP90AA1, p-NF-κB p65/NF-κB p65, LC3 II/I, ATG5, Beclin-1 and TLR protein were detected by western blot. RESULTS: Pg-LPS treatment didn't affect the viability of HGFs cells, but induced the cell apoptosis and ROS generation, increased the contents of IL-1ß, IL-6, TNF-α, and the protein expressions of HSP90AA1, p-NF-κBp65/NF-κBp65, LC3II/I, ATG5, and Beclin-1 in HGFs. While HSP90AA1-siRNA transfected into Pg-LPS induced HGFs significantly reduced the HSP90AA1, HSP90α, HSP90ß expression, decreased the inflammatory factors, ROS generation, cell apoptosis rate, and autophagy-related proteins and TLR2/4 protein levels. What's more, the addition of autophagy inhibitor 3-MA further promote the effect of HSP90AA1-siRNA on Pg-LPS treated HGFs. CONCLUSIONS: This study showed that HSP90AA1 promoted the inflammatory response of Pg-LPS induced HGFs by regulating autophagy. The addition of 3-MA further confirmed that autophagy may mediate siHSP90AA1 to enhance the inflammatory response.

Prognosis and predictive value of heat-shock proteins expression in oral cancer: A PRISMA-compliant meta-analysis.

BACKGROUND: Heat-shock proteins (HSP) is a key chaperone protein which maintains intracellular proteostasis and is expressed on the surface of solid and hematological malignancies. Several studies have reported paradoxical evidence of the association between HSP expression and prognosis of oral cancer. To address the discrepancy, we carried out the meta-analysis to assess the role of HSP such as: HSP70, HSP90, HSP27, HSP60, and HSP105 in susceptibility, progression, and prognosis of oral cancer. MATERIALS AND METHODS: We retrieved the PubMed, Embase, Web of science, China National Knowledge Infrastructure (CNKI), and Wanfang databases to acquire the eligible studies which were associated with HSP70, HSP90, HSP27, HSP60, and HSP105 protein expression and oral cancer. We applied hazard ratio (HR) and its 95% confidence interval (95% CI) to assess the value of HSP protein expression in overall survival of oral cancer; odds ratio (OR) and its 95% CI were used to evaluate the association of risk and clinical features of oral cancer. Funnel plot, Begg test, and Egger line regression test were utilized to observe publication bias among studies. All statistical analysis was performed with Stata 14.0 software (Stata Corporation, College Station, TX). RESULTS: A total of 26 studies were included in the present meta-analysis. On based of the results, HSP70 and HSP27 had no significant association with progression of oral cancer. However, the pooled HR and 95% CI revealed a significant well effects of HSP70 and HSP27 expression on survival of oral cancer. Moreover, the susceptibility of oral cancer was significantly associated with HSP70 and HSP60 overexpression. CONCLUSION: HSP70 and HSP27 protein overexpression might be valuable biomarkers for the prognosis of oral cancer. And HSP70 and HSP60 might have potential predictive effects on the risk of oral cancer.

A new type of aortic valved stent with good stability and no influence on coronary artery.

BACKGROUND: To evaluated the feasibility and safety of new aortic valved stents in transcatheter aortic valve implantation (TAVI) using retrograde approach by in vitro testing and animal implantation. MATERIALS AND METHODS: The fluid passing test, expanding and releasing tests, static and releasing tests in tube were performed for new valved stents. Transvalvular pressure gradient, effective orifice area, pre-implantation and post-implantation regurgitant volume for the new stents were detected. Then, the new stents were implanted in six pigs using retrograde approach. These pigs were euthanized 12 h after the implantation for anatomic evaluation. RESULTS: In vitro tests showed that the closure of the new stents leaflets were effective, and stents could be released through catheter, then expanded completely and fixed fast in the tube. The coronary artery flow rates did not changed significantly after implantation (P > 0.05), while aortic regurgitant volumes were obviously reduced (P < 0.05). No significant difference in the transvalvular pressure gradient and effective orifice area of the new stents implanted within or above the valve leaflets was found (P > 0.05). In vivo experiments indicated that TAVI was successfully performed in six pigs using retrograde approach. However, one pig was died 10 h after the implantation since the stent was not expanded completely. The leaflets in stents were opening well and no valvular regurgitation was observed in the other five pigs. And thrombosis was not found. DISCUSSION AND CONCLUSION: The new type of aortic valved stent designed in this study was characterized with good stability and could avoid the impact caused by valve leaflets on the coronary artery.

[Clinical analysis of two-phase treatment of 35 cases with Angle Class II division 1 malocclusion].

PURPOSE: To evaluate the clinical value of the two-phase treatment of Angle Class II division 1 malocclusion. METHODS: Thirty five cases with Class II division 1 malocclusion were treated with two-phase treatment(Twin-block functional appliance and fixed appliance).Lateral cephalograms were taken before and after treatment for each patient. The results were analyzed with paired t test using SPSS11.0 software package. RESULTS: After treatment ,the bite relation of molars ,the overbite and overjet and soft tissue profile were improved. ANB angle,U1-SN,OB,OJ,UL-E,ULP were decreased respectively(P<0.01). SNB, C(o)-G(o),G(o)-G(n),C(o)-G(n) were increased respectively(P<0.01). L1-Mp and FH-MP were increased, too(P<0.05). CONCLUSIONS: Twin-block functional appliance possesses the orthopedic effects on Angle Class II division 1 malocclusion.It limits the maxillary growth forward and promotes the mandibular growth by repositioning the mandible forward.These may contribute to a harmonious relationship of upper and lower jaws and a better profile.

[Effect of the valved stent on closure of patent ductus arteriosus in a miniswine model].

OBJECTIVE: To evaluate the feasibility of a valved stent on closure patent ductus arteriosus in a Chinese miniswine model. METHODS: Self-expandable nitinol stents were made of Ni-Ti shape memory alloy (9 mm in diameter). Bovine pericardium was shaped and sutured onto the stents. Fluid passing test, pre-releasing test and static test of pressure in tube were performed in all devices before use. In eight Chinese miniswine, vascular grafts (PTFE vascular prosthesis) were surgically inserted between the descending thoracic aorta and pulmonary artery for establishment of patent ductus arteriosus model. Valved stents were deployed to occlude the patent ductus arteriosus. Echocardiography was performed two hours post operation. Aortic angiography was made 30 days post operation in survived animals. Animals were then sacrificed for autopsy and electron microscopy examinations. RESULTS: In vitro testing showed that the closure of the valved stent leaflets was satisfactory and fluid flows were not restricted in the opposite direction. The valved stents could be released through catheter, expanded completely, rapidly fixed in the tube. Closure of patent ductus arteriosus was succeeded in 6 out of 8 animals. One animal died of respiratory failure 2 hours post operation, another one died of pulmonary embolism due to valved stent displacement. Resident shunt was not evidenced by echocardiography, aortic angiography and dissection examinations in the remaining 6 animals. The new endothelial tissue fully covered the pulmonary and aortic sides of patent ductus arteriosus in 4 and 3 animals respectively. The electron microscopic observation revealed endothelial coverage of dives. CONCLUSION: The valved stent could effectively close artificial patent ductus arteriosus in vivo with satisfactory new intima covering on both sides of patent ductus arteriosus.

[Coronary flow obstruction in percutaneous aortic valve replacement using self-expandable valved stent: an in vitro study].

OBJECTIVE: To study the effects of self-expandable and orthotopically implanted percutaneous aortic valved stent on coronary artery flow in vitro. METHODS: Self-expandable valved stent was developed with nitinol stent and bovine pericardium. The ascending aorta of Chinese mini swine hearts was cut proximal to the brachiocephalic trunk. The right and left main coronary arteries were dissected. In vitro coronary flow tests were performed. Firstly, baseline coronary flow with the native aortic valve was measured (n = 12). Secondly, the valved stent was deployed orthotopically. The commissures of prosthesis were positioned randomly. Through an endoscope, the effects of valved stent and native valve on coronary ostium were obtained and coronary flow measurements repeated (valve preservation group, n = 12). Then the distance from coronary ostium to native leaflet free edge was measured. Native leaflets were removed before similar valved stent deployment. Coronary flow measurements and endoscopic inspections were repeated post-implantation (valve removal group, n = 12). RESULTS: In valve preservation group, valved stent implantation resulted in a significant decrease in left coronary flow (29.46%, P < 0.05). The obstruction was due to native leaflets sandwiched between the stent and aortic wall. The left ostia were obstructed totally in 3 and partially in 4. The flow of right coronary decreased 7.34% (P > 0.05). The right ostia were obstructed partially in 3. In valve removal group, 6.82% and 5.37% decrement in left and right coronary flow were observed after valved stent placement (P > 0.05). The distances from right coronary ostia to annulus were farther than from left coronary ostia. In two groups, the commissures of prosthesis obstructed partially left coronary ostia in 4 and right coronary ostia in 1. CONCLUSION: Orthotopic implantation of a percutaneous self-expandable aortic valved stent would obstruct the left coronary ostium with the native valve. Coronary ostium may be obstructed partly by the commissures of prosthesis.

PI3K/AKT mediated p53 down-regulation participates in CpG DNA inhibition of spontaneous B cell apoptosis.

The unmethylated CpG DNA can prevent spontaneous apoptosis of B cells. However, the precise mechanisms by which CpG DNA blocks apoptosis remain unclear. In this study, we showed B cell apoptosis was significantly inhibited by addition of CpG DNA. Treatment of CpG DNA could reduce the expression of caspase 3, increase IAP and Bcl-xL expressions, and inhibit p53 protein expression which level was increased in B cell spontaneous apoptosis at 24 h. AKT kinase activity was increased with the incubation of CpG DNA. The wortmannin and Ly294002 could abrogate the protection of B cell from apoptosis by CpG DNA. The up-regulations of Bcl-xL and IAP by CpG DNA were not inhibited when blocking PI3K by specific inhibitor Ly294002, while the inhibition of p53 by CpG DNA could be blocked by Ly294002. These results demonstrated that the inhibition of spontaneous B cell apoptosis by CpG DNA was correlated to up-regulation of Bcl-xL, IAP and down-regulation of p53 and caspase 3. CpG DNA inhibition of p53 is mediated through PI3K/AKT signaling.

Results of radiofrequency ablation for permanent atrial fibrillation in patients undergoing mitral valve surgery.

OBJECTIVES: The study aim was to evaluate the safety and feasibility of radiofrequency ablation for the surgical treatment of permanent atrial fibrillation in patients with degenerative mitral valve disease. DESIGN: From August 2000 to August 2003, 40 consecutive patients (mean age 69.0 +/- 9.3 years) with permanent atrial fibrillation and degenerative mitral valve disease underwent surgical radiofrequency ablation in conjunction with 22 mitral valve repairs and 18 mitral valve replacements. The mean duration of chronic AF was 5.1 +/- 3.4 years. The completeness of follow-up was 100%. The mean follow-up time was 4.6 +/- 2.0 years (range 0 to 7.8 years). RESULTS: Thirty-day mortality was 2.5% (1 patient), the cause of death was cardiac failure. Cardiac failure and temporary A-V block were the most common postoperative complications. Both occurred in 10% (4 patients). No complication was related to the ablation procedure. At discharge, 65% (26/40) of the patients were in sinus rhythm. Overall incidence of sinus rhythm at the end of the follow-up was 56.4% (22/39).The 1-, 3- and 5-year survival was 97.5%, 91.8% and 85.9%, respectively. CONCLUSION: Mitral valve surgery combined with radiofrequency ablation is a safe and effective procedure in patients with permanent atrial fibrillation and degenerative mitral valve disease. The result is encouraging in restoring sinus rhythm, and an excellent postoperative survival rate can be achieved.

Transcatheter closure of adult patent ductus arteriosus with severe pulmonary hypertension.

The purpose of this study was to investigate the application of trial balloon occlusion for permanent closure of patent ductus arteriosus (PDA) with severe pulmonary hypertension (PH) in adults, and to assess its immediate and short-term results. From September 1999 to September 2005, a total of ten adults (two males, ages ranging from 20 to 54 years) with PDA who met the criterion for severe PH (basal pulmonary vascular resistance >8 Wood units) received trial balloon occlusion via an embolectomy balloon catheter. Post-occlusion hemodynamics, along with an overall clinical and hemodynamic assessment, was used to consider the indication of closure of PDA. Nine of the patients underwent successful transcatheter closure of PDA and subsequently used Amplatzer occluder devices. Chest X-ray, cardiography and echocardiography were used for follow-up evaluation of the treatment within 6 months after successful closure of PDA. No patient had a detectable residual shunt by color flow mapping or any other complications (device migration, hemolysis, endocarditis, etc.) at follow-up. In conclusion, trial balloon occlusion helps to determine anticipated hemodynamics after closure of PDA, so it is conducive to indicating permanent closure of adult PDA with reversible but severe PH. Furthermore, satisfactory immediate and short-term outcomes have proven this method to be safe and valid. (Hypertens Res 2008; 31: 1997-2002).

[Combined use of transmyocardial stents with gene therapy in the treatment of acute myocardial infarction].

OBJECTIVES: To determine the efficacy of combined use of transmyocardial stent with gene therapy to treat acute myocardial infarction in porcine model. METHODS: 24 Chinese mini swines have been divided into 4 groups randomly: group myocardial infarction (group MI n(1) = 6), group transmyocardial stent (group ST n(2) = 6), group vascular endothelial growth factor (group VEGF n(3) = 6), group transmyocardial stent and VEGF (group ST + VEGF n(4) = 6). In group MI, acute myocardial infarction animal model has been established by the ligation of the left descending coronary artery. In group ST, after the establishment of the model, 3 transmyocardial stents were implanted. In group VEGF, an expression plasmid containing the gene-encoding VEGF(165) (300 microg) was administered directly in the myocardium at 6 sites. In group ST + VEGF, both transmyocardial stents and expression plasmid containing the gene-encoding VEGF(165) are applied. 4 weeks later, the animals are sacrificed and echocardiography and pathological analysis have been done. RESULTS: The density of blood vessel in group ST, VEGF and ST + VEGF are significantly higher than group MI. And capillary density in group ST + VEGF is the highest in these groups statistically. Expression of VEGF was detected in group ST, VEGF and ST + VEGF, but in group VEGF and ST + VEGF the level of expression are higher. CONCLUSION: Combined use of transmyocardial stent with gene therapy has synthetic effect for the treatment of acute myocardial ischemia in porcine model and can significantly increase the vascular density.

[Survival after pulmonary metastasectomy: experience in 26 patients].

BACKGROUND: Surgical resection becomes standard treatment for pulmonary metastatic tumor with operative indication. The aim of this study is to analyze the indication and surgical efficacy of pulmonary metastasectomy. METHODS: From November 1991 to May 2003, a total of 26 patients with pulmonary metastatic tumors were treated surgically in our hospital, 12 cases were males and 14 females, with an average age of 50 years old. The metastatic tumors came from different organs and tissues, 5 cases accompanied by metastatic tumors of liver or brain. RESULTS: Four cases underwent pneumonectomy, 8 lobectomy, and 14 wedge resection (in which 8 cases underwent mildly invasive operation using video-assisted thoracic surgery). No operative death occurred. 5-year survival rate was 27.3% (3/11), 2-year survival rate 42.9% (9/21) and 1-year survival rate 69.2% (18/26). CONCLUSIONS: Pulmonary metastasectomy is recommended in pulmonary metastases with operative indication, and is still effective in cases accompanied by resectable metastatic tumors of liver or brain. Mildly invasive operation using video-assisted thoracic surgery might be chosen for some cases with single metastatic locus.