Effect of the compound bacterial agent on microbial community of the aerobic compost of food waste.

In our study, we used 16SrRNA and ITS to investigate the microbial community composition and the effect of compound bacterial agent on the microbial community composition in the aerobic composting process of food waste (FW). At the bacterial level, the main phyla of Group A (compost naturally) were Proteobacteria and Firmicutes, and the main species were Pseudomonas_sp._GR7, Bacillus licheniformis and Pediococcus acidilactici. The main phyla of Group B (compost with compound bacterial agent) were Proteobacteria, Firmicutes and Streptophyta, and the main species were Klebsiella pneumoniae, Cronobacter sakazakii, Macrococcus caseolyticus, Enterococcus faecalis, Citrobacter freundii and Bacillus velezensis. It is worth noting that M. caseolyticus may be able to improve the effect of odour which is an important sensory index during aerobic composting. At the fungal level, the main phylum of both Groups A and B was Ascomycota, and the main species of Group A were Paecilomyces variotii, Byssochlamys spectabilis and Aspergillus fumigatus. The main species of Group B were Ogataea polymorpha and Millerozyma farinosa. Finally, the degradation rate of Group B was 81% that was about 15% higher than that of Group A, indicating that the compound bacterial agent could effectively improve the degradation rate and the composting process, while the low abundance of the compound bacterial agent in the composting process might be due to the small initial addition or the inhibition of other bacteria or fungi in the composting process.

[Efficacy of fenestrated atrial septal defect occulders on pulmonary hypertension dogs].

Objective: To explore the short-term efficacy of fenestrated atrial septal defect (ASD) occulders in the treatment of pulmonary arterial hypertension (PAH). Methods: Thirty-six healthy dogs were divided into the balloon atrial septostomy (BAS)+fenestrated ASD occulders group (n=12), BAS group (n=12) and non-septostomy group (n=12). PAH was induced by intra-atrial injection of dehydrogenized monocrotaline (1.5 mg/kg) in all dogs. Animals in the BAS+fenestrated ASD occulders group underwent atrial septal puncture and fenestrated ASD occulders implantation. Animals in the BAS group underwent balloon atrial septostomy. The non-septostomy group received no surgical intervention. The hemodynamic indexes and blood N-terminal pro-B-type natriuretic peptide (NT-proBNP) of dogs were measured before modeling, 2 months after modeling, 1, 3, and 6 months after surgery, respectively. Echocardiography was performed to observe the patency of the shunt and atrial septostomy of the dogs in the BAS+fenestrated ASD occulders group and BAS group at 1, 3, and 6 months after surgery. Three dogs were sacrificed in each group at 1, 3, and 6 months after surgery, respectively. Atrial septal tissue and fenestrated ASD occulders were removed to observe the patency and endothelialization of the device. Lung tissues were obtained for hematoxylin-eosin (HE) staining to observe the inflammatory cells infiltration and the thickening and narrowing of the pulmonary arterials. Results: Among 36 dogs, 2 dogs died within 24 hours after modeling, and 34 dogs were assigned to BAS+fenestrated ASD occulders group (n=12), BAS group (n=11), and non-septostomy group (n=11). Compared with BAS group, the average right atrial pressure (mRAP) and NT-proBNP of dogs in the BAS+fenestrated ASD occulders group were significantly reduced at 3 months after surgery (P<0.05), and the cardiac output (CO) was significantly increased at 6 months after surgery, arterial oxygen saturation (SaO2) was also significantly reduced (P<0.05). Compared with non-septostomy group, dogs in the BAS+fenestrated ASD occulders group had significantly lower mRAP and NT-proBNP at 1, 3, and 6 months after surgery (P<0.05), and higher CO and lower SaO2 at 6 months after surgery (P<0.05). Compared with the non-septostomy group, the dogs in the BAS group had significantly lower mRAP and NT-proBNP at 1 month after surgery (P<0.05), and there was no significant difference on mRAP and NT-proBNP at 3 and 6 months after surgery (P>0.05). Echocardiography showed that there was a minimal right-to-left shunt in the atrial septum in the BAS group at 1 month after the surgery, and the ostomy was closed in all the dogs in the BAS group at 3 months after the surgery. There was still a clear right-to-left shunt in the dogs of BAS+fenestrated ASD occulders group. The shunt was well formed and satisfactory endothelialization was observed at 1, 3 and 6 months after surgery. The results of HE staining showed that the pulmonary arterials were significantly thickened, stenosis and collapse occurred in the non-septostomy group. Pulmonary microvascular stenosis and inflammatory cell infiltration in the pulmonary arterials were observed in the non-septostomy group. Pulmonary arterial histological results were comparable between BAS+fenestrated ASD occulders group and non-septostomy group at 6 months after surgery. Conclusions: The fenestrated ASD occulder has the advantage of maintaining the open fistula hole for a longer time compared with simple balloon dilation. The fenestrated ASD occulder can improve cardiac function, and it is safe and feasible to treat PAH in this animal model.

[Effects of transcatheter aortic valve replacement in patients with severe aortic valve stenosis].

Objective: To investigate the effects of transcatheter aortic valve replacement (TAVR) in patients with severe aortic valve stenosis. Methods: The clinical data of 130 patients with severe aortic valve stenosis, who underwent TAVR in our hospital with self-expanding valve between January 1,2010 and October 30, 2016, were analyzed retrospectively. The patients were divided into calcific aortic valve stenosis (CAS) group (112 cases) and non-calcific aortic valve stenosis (NCAS) group (18 cases) according to 3D volume-rendering reconstruction under multiple detector computed tomography before TAVR. The baseline clinical features, imageology results, procedural details, and clinical prognosis were compared between the 2 groups. Results: (1) Compared with CAS group, the patients in NCAS group were younger, had higher proportion of rheumatic heart disease, and less proportion of bicuspid aortic valve morphology (P<0.01 or 0.05). Except for minimum value of sinotubular junction (P=0.017), there were no significant differences in multiple detector computed tomography measurements of aortic valve annulus and aortic root structure between the 2 groups (all P>0.05). (2) Compared with CAS group, the proportions of valve release under rapid pacing and oversized valve release were larger than pre-procedural evaluation, and the proportion of post-dilation was lower in NCAS group (P<0.01 or 0.05). (3) Post-procedural transthoracic echocardiography revealed that left ventricular ejection fraction was higher than baseline level in CAS group (P<0.001), while which was similar in NCAS group (P=0.552). Compared with before TAVR, mean pressure gradient and maximum transvalvular velocity were significantly reduced, aortic valve orifice area was significantly increased, and proportion of moderate to severe aortic regurgitation was significantly reduced after the procedure in both groups (all P<0.01). There were no significant differences in left ventricular ejection fraction, mean pressure gradient, maximum transvalvular velocity, aortic valve orifice area, and proportion of moderate to severe aortic regurgitation after TAVR between the 2 groups (all P>0.05). (4) There were no significant differences in successful rate of device placement and cardiovascular related death within 30 days after TAVR between the 2 groups (105/112 vs. 17/18, P=0.909; 3/112 vs. 1/18, P=0.453, respectively). Conclusion: TAVR is safe and effective for patients with severe aortic valve stenosis.

[Analysis of pulmonary valve function in patients with tetralogy of Fallot after radical surgery].

Objective: To analyze the pulmonary valve function in patients with tetralogy of Fallot after radical surgery. Methods: Clinical data of 263 patients (119 male, mean age (33.2±11.5) years old) with tetralogy of Fallot underwent radical surgery in our hospital from January 2010 to June 2016 were retrospectively analyzed. According to age, patients were divided into 14-17 years old group (14 cases), 18-29 years old group (100 cases), 30-39 years old group (61 cases) and above 40 years old group (87 cases). The patients were divided into pulmonary regurgitation group (87 cases) and control group (176 cases) according to weather they have moderate or severe pulmonary regurgitation. Echocardiographic data were compared among groups. Results: A total of 83 patients received re-operation. The median age of the primary radical operation was 9 (5, 13) years, and the median time from the primary radical operation to echocardiographic follow-up was 5 (1, 13) years. Among the 263 enrolled patients, prevalence of pulmonary regurgitation was 36.1% (95/263), and pulmonary stenosis was evidenced in 28 patients (10.6%). The ratio of moderate to severe tricuspid regurgitation was 14.3% (2/14), 27.0% (27/100), 32.8% (20/61) and 37.9% (33/87) in 14-17 years old group, 18-29 years old group, 30-39 years old group and above 40 years old group, respectively (P=0.029), while prevalence of moderate and severe pulmonary regurgitation, moderate and severe pulmonary valve stenosis, pulmonary valve transvalvular pressure >40 mmHg (1 mmHg=0.133 kPa), right atrial and right ventricular enlargement ratio were similar among groups (all P>0.05). The ratio of moderate and severe tricuspid regurgitation and right ventricular enlargement in the pulmonary regurgitation group was significantly higher than in the control group (40.2% (35/87) vs. 27.3% (48/176) and 96.6% (84/87) vs. 87.5% (154/176), all P<0.05), while left ventricular ejection fraction, right atrial enlargement, and right ventricular wall thickness were similar between the two groups (all P>0.05). Conclusion: Pulmonary regurgitation is a common clinical feature among survivors of tetralogy of Fallot patients after radical surgery, and moderate to severe pulmonary regurgitation increases the risk of tricuspid regurgitation and enlargement of the right ventricle.

[DNA shuffling of ptr resistance gene leads to improved pristinamycin production in Streptomyces pristinaespiralis].

In order to enhance pristinamycin production, six homologous ptr genes from high pristinamycin-producing strains of Streptomyces pristinaespiralis were selected for DNA shuffling, and the reason for the altered activities of the shuffled ptr gene was speculated by sequence alignment. The highest pristinamycin yield of 0.12 g/L was achieved with a sixfold increase in strain sps16 obtained by DNA shuffling when compared to ancestral strain ATCC 25486. Sequence analysis of theptr gene variant from the sps16 strain indicated that five mutations (H16P, N63D, T75P, Q107R, and P435A) were introduced into the gene, two of them (N63D and T75P) located in the second of the 14 transmembrane segments (TMS). Prediction of the secondary structure of the gene product indicated that mutations at the N-terminus resulted in the shortening of the corresponding α-helix, while the mutation at the C-terminus lengthened the helix. In conclusion, combination of DNA shuffling with genome shuffling is an effective breeding strategy for increasing the antibiotic yield by directed evolution of target genes.

Enhanced production of spinosad in Saccharopolyspora spinosa by genome shuffling.

Spinosad (spinosyns A and D) is a mixture of secondary metabolites produced by Saccharopolyspora spinosa. It is used in agriculture as a potent insect control agent with exceptional safety to non-target organisms. In this study, we applied genome shuffling of S. spinosa to achieve a rapid improvement of spinosad production. Ten strains with subtle improvements in spinosad production were obtained from the populations generated by the mutation with nitrosoguanidine and ultraviolet irradiation, and then they were subjected for recursive protoplast fusion. After four rounds of genome shuffling, a high yielding strain, designated as S. spinosa 4-7, was successfully isolated. Its production reached 547 mg/L, which was increased by 200.55% and 436.27% in comparison with that of the highest parent strain and the original strain, respectively. The subculture experiments indicated that the high producer of S. spinosa 4-7 was stable. Spinosad fermentation experiments by S. spinosa 4-7 were carried out in a 5-L fermentor, and its production of spinosad reached 428 mg/L after 168 h of fermentation.

Hemoglobin Chongqing [alpha 2(NA2)Leu----Arg] and hemoglobin Harbin [alpha 16(A14)Lys----Met] found in China.

Hemoglobin Chongqing is a new slowly-moving and unstable hemoglobin variant with a high oxygen affinity, that was discovered in five members of a Chinese family in the suburb of Chongqing. Hemoglobin Harbin is another new rapidly-moving hemoglobin variant with slightly reduced stability and slightly increased oxygen affinity, found in a Chinese woman living in Harbin. The relative amounts of these two variants in the propositi were about 9% and 18%, respectively. Sequence analyses identified a Leu----Arg substitution at position alpha 2(NA2) of Hb Chongqing, and a Lys----Met substitution at position alpha 16(A14) of Hb Harbin.