Bacillus subtilis is a generally recognized as safe (GRAS) strain that has been widely used in industries including fodder, food, and biological control. In addition, B. subtilis expression system also plays a significant role in the production of industrial enzymes. However, its application is limited by its low sporulation frequency and transformation efficiency. Immense studies have been done on interpreting the molecular mechanisms of sporulation and competence development, whereas only few of them were focused on improving sporulation frequency and transformation efficiency of B. subtilis by genetic modification. The main challenge is that sporulation and competence development, as the two major developmental events in the stationary phase of B. subtilis, are regulated by the complicated intracellular genetic regulatory systems. In addition, mutual regulatory mechanisms also exist in these two developmental events. With the development of genetic and metabolic engineering, constructing genetic regulatory networks is currently one of the most attractive research fields, together with the genetic information of cell growth, metabolism, and development, to guide the industrial application. In this review, the mechanisms of sporulation and competence development of B. subtilis, their interactions, and the genetic regulation of cell growth were interpreted. In addition, the roles of these regulatory networks in guiding basic and applied research of B. subtilis and its related species were discussed.
Bacillus subtilis ; genetics ; physiology ; Gene Regulatory Networks ; Metabolic Engineering ; Spores, Bacterial ; physiology

Objective　To study the role of TNFα in the plasm a and skin and IL-1 in the serum in the formation of secondary thrombosis after skin avulsion. Methods　After avulsive flap at size of 12 cm×4 cm was inflicted on the hind legs of pigs, skin specimens and venous blood sam ples were taken at various time points. The contents of TNFα in plasma and skin were determined with radio-immunoassay, and the activity of serum IL-1 wi th 3［H］-TdR. Results　The TNFα contents in the plasma and skin were increased significantly after avulsion（P<0.01），which were (41 5±24) ng/L and (298±18.5) ng/L respectively on the 3rd day after the injury. T he activity of IL-1 in the serum was increased (P<0.05) and was (2.59± 0.85 ) ng/L on day 3. Conclusion　The changes of TNFα contents and I L-1 activity in blood and skin play important roles in the inducetion and aggra vation of secondary tissue necrosis and early thrombosis after skin avulsion.

Objective To discuss the blockage reasons and countermeasures of temporary catheter in central venous including femoral vein and internal jugular vein for hemodialysis patients.Methods The reasons of blockage of temporary catheter in central venous among 60 hemodialysis patients from January 2014 to September 2015 in Hemodialysis Room of the First People's Hospital of Longquanyi district of Chengdu were reviewed.There were 32 cases in femoral vein and 28 cases in the right internal jugular vein.The incidence of blockage of the two temporary catheter in the first two weeks,the incidence of blockage caused by mechanical factors and blood clots or fibrous sheath and the incidence of blockage which needed to change the catheter in the two groups patients within the first two months were analyzed.Results The first rate of defective function in the first two weeks of femoral vein group was 53.13％(17/32),and 7.14％(2/28) of the right internal jugular vein group,there were significant difference between the two groups (x2=13.061,P＜0.001).The incidence of catheter blockage due to mechanical factors of femoral vein group was 96.88％ (31/32),and 53.57％ (15/28) of the right internal jugular vein,there were significant difference between the two groups (x2 =15.654,P＜0.001).The incidence of blockage caused by blood clots or fibrous sheath and the incidence of blockage which needed to change the catheter in the first two months were no significant differences between the two groups(P=0.061,0.096).Conclusion The cases of temporary catheter in femoral vein have blockage earlier,and they have a higher risk of catheter jam than the cases of temporary catheter in right internal jugular vein.

Objective To analyze the clinical features of the hyperamylasemia in critically ill children and investigate the related risk factors in order to provide the basis for prevention and treatment. Methods A total of 1036 critically ill children admitted in pediatric intensive care unit (PICU)from April,2011 to Oct,2012 were studied.They were divided into the high amylase group (n=82)and the normal group (n=954).According to the outcomes,the high amylase group was divided into survival group (n=61 ) and death group (n =21 ).The related risk factors of the occurrence and outcome of hyperamylasemia were analyzed by univariate and multivariate Logistic regression.Results There were statistically significant differences in rates of coagulation disorders, convulsions, disturbance of consciousness,pediatric critical illness score (PCIS)≤80,multiple organ dysfunction (MODS)≥3, sepsis,shock,and lactic acid (LA),procalcitonin (PCT),blood glucose (BG)between the high amylase group and the normal group (P<0.05 ).The differences in the rates of coagulation disorders,convulsions, mechanical ventilation,PCIS≤80,MODS≥3,and LA,PCT,oxygenation index,albumin,C-peptide,BG were statistically significant between the survival group and the death group (P <0.05 ).Multivariate Logistic regression analysis showed that the risk factors of the hyperamylasemia's occurrence were LA,PCT, BG,PCIS<80,MODS>3.Adjusted ORs confidence intervals of them were 1.662 (1.236-2.234),1.042 (1.025-1.060),1.612 (1.411-1.843),3.219 (1.311-7.905),3.411 (1.370-8.494),respectively. The hyperamylasemia's prognostic risk factors were PCT,C-peptide,PCIS ≤80,MODS >3,shock. Adjusted ORs confidence intervals of them were 1.066(1.021-1.113),1.437(1.017 ~2.030),16.137 (1.876-138.836),10.437(1.528-71.925),20.928(1.938-226.009),respectively.Conclusions The severity of the disease,the levels of LA,PCT,BG in critically ill children were positively correlated to the occurrence of hyperamylasemia.The severity of the disease,the incidence of organ failures,the levels of PCT,C-peptide combined shock in children with hyperamylasemia were positively correlated to the prognosis of hyperamylasemia.

Objective To analyze the clinical features of critically ill children with abnormal pancreatic ultrasound findings in order to explore the related risk factors for offering evidence-based diagnosis of pancreatic damage secondary to critical illness.Methods A prospective study was performed in 531 critically ill children admitted to pediatric intensive care unit(PICU) of 17 children' hospitals from January 2012 to March 2014.All patients were divided into control group(513 cases) and abnormal group(18 cases) according to the pancreatic ultrasound findings.Comparison of clinical features and biochemical indicators were made between two groups.The related risk factors associated with abnormal pancreatic ultrasound findings were analyzed by using Logistic regression analysis.ROC curves were used to evaluate the role of amylase and lipase in the diagnose of abnormal pancreatic ultrasound findings.Results The incidence of abnormal pancreatic ultrasound findings in critically ill children was 3.39%, the average age of abnormal group was significantly older than that in control group (P<0.01).There were not statistically significant differences in gender and primary disease between two groups.The incidence of hypotension was 22.2% and the incidence of abdominal muscle tension was 16.7% in abnormal group,which were statistically higher than those in control group (P<0.05).The levels of calcium, albumin of abnormal group were significantly lower than those in control group (P<0.01), and levels of serum amylase, lipase, lactate dehydrogenase in abnormal group were significantly higher than those in control group (P<0.01).The risk factors associated with abnormal pancreatic ultrasound findings were age, blood pressure, calcium,amylase.Area under the ROC curve of abnormal pancreatic ultrasound findings determined by amylase and lipase were 0.803 and 0.745,respectively (P<0.05).The sensitivity was 0.667, specificity was 0.881 when the serum amylase was 101.5 U/L, the sensitivity was 0.722, specificity was 0.928 when the serum lipase was 96.9 U/L.Conclusions The incidence of abnormal pancreatic ultrasound findings was rather low in critically ill children.The risk factors associated with abnormal pancreatic ultrasound findings were hypotension, hypocalcemia, and hyperamylasemia.The elevated serum amylase and lipase might be the most likely factors associtaed with abnormal pancreatic ultrasound findings.

Objective To examine the effect of modified electroconvulsive therapy (MECT) on the plasma oxida-tive stress level in bipolar depression. Methods Forty-two patients with bipolar depression were randomly divided into two groups. The intervention group (n=18) received antidepressants and 12 times MECT for 6 weeks and the control group (n=24) received antidepressants and Li2CO3 for 6 weeks. The Chinese versions of the 17 items Hamilton Depression Rating Scale (HAMD-17), Young Mania Rating Scale (YMRS), Clinical Global Impression Scale (CGI-S) and Treatment Emergent Symptom Scale (TESS) were used to assess participants at baseline and after 6 weeks of treatment. The plasma levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA)were detected at baseline and after 6 weeks to assess the level of oxidative stress. Results Repeated measures analysis of variance showed that the plasma level of SOD was higher in MECT group than in Li2CO3 group (F=15.26, P<0.01), and the level of MDA was higher in Li2CO3 group (F=18.18, P<0.01). The interactive effect of group and time was significant in GSH-Px level (F=6.39, P=0.02). The level of GSH-Px was lower in MECT group than in Li2CO3 group after 6 weeks (P<0.05). The CAT level was higher in the response patients than in non-response patients after 6 weeks (P<0.05). Con-clusions Both MECT treatment and Li2CO3 treatment can alter oxidative stress levels in patients with bipolar depression. The mechanisms underlying its therapeutic regimen may correct the imbalance of the plasma CAT level.

Objective To comment the severity of severe hand,foot and mouth disease(HFMD)by pediatric risk of mortality score(PRISM),and assess the performance of PRISM in predicting mortality or complication probability in HFMD.Methods Four hundred and twenty-four severe HFMD pediatric patients were recruited in the study from 1th Jan 2010 to 31th June 2013.Information on the outcome and the varia-bles required to calculate PRISM score were collected.The logistic regression model developed in the learning sample was evaluated in the test sample by calculating the area under the receiver operating characteristic (ROC)curve to assess discrimination pneumorrhagia and death.Calibration across deciles of risk was evalua-ted using the Hosmer-Lemeshow goodness-of-fit χ2 test.Results The area under the ROC curve were 0.87 (95%CI 0.80~0.94 )for PRISM in predicting pneumorrhagia probability.The area under the ROC curve were 0.87(95%CI 0.80~0.95)for PRISM in predicting mortality probability.The PRISM in observed and expected pneumorrhagia did not demonstrate good calibration at ten mortality risk intervals (χ2 =36.66, P<0.001 ).The PRISM in observed and expected mortality did not demonstrate good calibration at ten mortali-ty risk intervals(χ2 =41.11,P<0.001).Conclusion The PRISM score is demonstrated good discrimination of pneumorrhagia and death in HFMD pediatric patients,but the performance of calibration is not good.

Objective To investigate the prognostic value of amino-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with sepsis.Methods A total of 162 patients was enrolled with consecutive pediatric intensive care unit (PICU) admissions during the study period of Jan 1st,2013 to June 30th,2013 at Hunan Children's Hospital.The 162 septic patients were divided into sepsis group and severe sepsis group,sepsis group and septic shock group,and survival group and death group.NT-proBNP was tested in the first and third day after 162 septic patients in hospital.Pediatric critical illness score (PCIS) score was assessed in all patients.NT-proBNP was compared between groups.The change of NT-proBNP was summarized between groups.The relationship between NT-proBNP and PCIS was analyzed.Results (1) The plasma NT-proBNP level of the first day after admission in the severe sepsis group and septic shock group was higher than sepsis group,the PCIS in the sepsis group was higher than severe sepsis group and septic shock group,with significant difference (P ＜ 0.05).(2) The plasma NT-proBNP level of the first day after admission in the death group was higher than the survival group,the PCIS in the death was lower than the survivor group,with significant difference (P ＜ 0.05).In the death group,the plasma NT-proBNP level of the third day after admission was higher than the NT-proBNP of the first day after admission (P =0.037) ; contrarily,the plasma NT-proBNP level of the third day after admission was lower than the NT-proBNP of the first day after admission in the survival group (P =0.023).Conclusions NT-proBNP could be used to assess the condition of septic patients,and dynamic test NT-proBNP can help to predict septic patient’s prognosis.

Objective To evaluate the early diagnosis value of serum cystatin C in the pediatric intensive care unit (PICU) children with septic acute kidney injury.Methods A total of 196 children in PICU confirmed with sepsis in Hunan Province Children's Hospital was enrolled in this study.Patients were divided into acute kidney injury (AKI) and non-AKI group according to whether accompanied with acute kidney injury.The serum cystatin C and serum creatinine were collected in 2 h,48 h,and 96 h after admission,and the clinical data were collected.The serum Cys C was drawn in receiver operating characteristic (ROC) curve.The sensitivity and specificity of Cys C were evaluated in diagnosis of septic AKI.Results The incidence of septic AKI was 35.20％,higher Cys C levels were risk factors for the onset of AKI,and OR was 26.218 (95％ CI:6.235 ～ 110.232).In AKI group,the serum Cys C level in 2 hours after admission was (2.05 ± 0.90)mg/L,which was higher than 48 hours (1.72 ± 0.72)mg/L and 96 hours (1.62 ±0.95) mg/L(Z =2.169,P =0.030; Z =2.789,P =0.005).In the septic AKI group,cystatin C and creatinine were positive correlation (r =0.582,P =0.000).The area under the ROC curve at 2hours after admission for serum cystatin C in diagnosis of AKI was 0.831.A cutoff point of 1.325 mg/L for 2 hours after admission was identified for cystatin C in the diagnosis of septic AKI,with a sensitivity of 87.1％and specificity of 78.9％.Conclusions Higher level of Cys C was risk factor for the onset of AKI.Compare to creatinine,cystatin C was earlier increased in children with septic AKI and positively correlated with it.It might be a biomarker for early diagnosis of septic AKI in PICU critical ill children.

Objective To evaluate the clinical value of N-terminal pro brain natriuretic peptide (NT-proBNP) in septic children with myocardial damage.Methods From Jan 1 to Jun 30,2013,162 children confirmed with sepsis in PICU of Hu'nan Children's Hospital were enrolled in the study.Patients were divided into myocardical injury and non-myocardical injury group according to whether accompanied with myocardial injury.NT-proBNP,lactate dehydrogenase,creatine kinase isoenzyme (CK-MB),troponin Ⅰ (cTnⅠ),myoglobin(MB) of patients were measured within 24 h after admission.The NT-proBNP level between two groups was compared.The correlations between NT-proBNP and cTnⅠ,CK-MB were studied respectively.Results The NT-proBNP level[M(Q)] in myocardial injury group[3 632 (668.5,15 453.5) pg/ml] was higher than that in non-myocardial injury group[349 (169,1 500) pg/ml],which was significantly different(Z =91.881,P =0.000).The levels of NT-proBNP,CK-MB,cTnⅠ,MB were abnormal distributions.There were positive correlations between logNT-proBNP and logCK-MB (r =0.367,P =0.000),logcTnⅠ(r =0.304,P =0.001) and logMB (r=0.302,P =0.000).NT-proBNP value of 1 163 ng/ml had a sensitivity of 76％ and a specificity of 74％ to diagnose myocardial injury.Conclusion NT-proBNP could help to diagnose sepsis with myocardial damage.