Investigation of the enhancement for Echinocandin B fermentation with methyl oleate from transcription level.

Echinocandin B (ECB) is the key precursor compound of the antifungal drug Anidulafungin. The effects of the five precursor amino acids on ECB biosynthesis were firstly investigated. It showed that although L-threonine was a main compound of the hexapeptide scaffold of ECB, exogenous addition of L-threonine had no significant effect on the increase of ECB fermentation titer. Meanwhile, the ECB fermentation titer with methyl oleate showed two times higher than that of the other carbon sources. Transcription level analysis of the key genes for ECB biosynthesis indicated that the gene an655543 related to L-threonine biosynthesis showed higher value during the fermentation process, therefore, the exogenous addition of L-threonine had no obvious affection. Furthermore, it indicated that the transcription level of gene ecdA might be the main restriction factor for the ECB biosynthesis. The study provided the research foundation for the modification of the ECB producing strains in the following work.

Sweet Sorghum Originated through Selection of Dry, a Plant-Specific NAC Transcription Factor Gene.

Sorghum (Sorghum bicolor) is the fifth most popular crop worldwide and a C4 model plant. Domesticated sorghum comes in many forms, including sweet cultivars with juicy stems and grain sorghum with dry, pithy stems at maturity. The Dry locus, which controls the pithy/juicy stem trait, was discovered over a century ago. Here, we found that Dry gene encodes a plant-specific NAC transcription factor. Dry was either deleted or acquired loss-of-function mutations in sweet sorghum, resulting in cell collapse and altered secondary cell wall composition in the stem. Twenty-three Dry ancestral haplotypes, all with dry, pithy stems, were found among wild sorghum and wild sorghum relatives. Two of the haplotypes were detected in domesticated landraces, with four additional dry haplotypes with juicy stems detected in improved lines. These results imply that selection for Dry gene mutations was a major step leading to the origin of sweet sorghum. The Dry gene is conserved in major cereals; fine-tuning its regulatory network could provide a molecular tool to control crop stem texture.

CDK5-mediated phosphorylation of Sirt2 contributes to depressive-like behavior induced by social defeat stress.

Major depressive disorder (MDD) is a common, severe and recurrent psychiatric disorder worldwide; however, the underlying neuropathological mechanisms remain elusive. Histone deacetylases (HDACs) appear to play an essential role in depression. As the class III HDACs, Sirt1 and Sirt2 have attracted the most interest in the nervous system. Indeed, chronic stress decreased Sirt1 activity and down-regulated Sirt1 gene expression in MDD. Nevertheless, there is a paucity of literature on the role of Sirt2. To study the role of Sirt2 we established a MDD mouse model in wild type and Sirt2 knockout C57BL/6 mice using social defeat stress (SDS). We found that a lack of Sirt2 blocked the development of SDS-induced depressive-like behavior. Moreover, SDS led to Sirt2 phosphorylation in the amygdala without changing total Sirt2 levels, and blocking the phosphorylation of Sirt2 by CDK5 at serine residues 368 and 372 prevented SDS-induced depressive-like behavior and Sirt2 nuclear import. We also discovered that SDS-induced Sirt2 phosphorylation was involved in VTA-amygdala modulation using TetTag-pharmacogenetic method. These results suggest that CDK5 mediates phosphorylation of Sirt2 in the amygdala and contributes to the depressive-like behavior induced by SDS. This study highlights that inhibiting CDK5-dependent phosphorylation of Sirt2 at serine residues 368 and 372 by myristoylated membrane-permeabilising peptide (Sirt2-p), rather than using non-specific sirtuin inhibitors, may be a novel strategy for treating depression.

Cdk5 suppression blocks SIRT1 degradation via the ubiquitin-proteasome pathway in Parkinson's disease models.

The NAD+-dependent protein deacetylase sirtuin 1 (SIRT1), a member of the sirtuin family, may have a neuroprotective effect in multiple neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD) and Amyotrophic lateral sclerosis (ALS). Many studies have suggested that overexpression-induced or resveratrol-treated activation of SIRT1 could significantly ameliorate several neurodegenerative diseases in mouse models. However, the type of SIRT1, protein expression levels and underlying mechanisms remain unclear, especially in PD. In this study, the results demonstrated that SIRT1 knockout markedly worsened the movement function in MPTP-lesioned animal model of PD. SIRT1 expression was found to be markedly decreased not only in environmental factor PD models, neurotoxin MPP+-treated primary culture neurons and MPTP-induced mice but also in genetic factor PD models, overexpressed α-synuclein-A30PA53T SH-SY5Y stable cell line and hm2α-SYN-39 transgenic mouse strain. Importantly, the degradation of SIRT1 during MPP+ treatment was mediated by the ubiquitin-proteasome pathway. Furthermore, the results indicated that cyclin-dependent kinase 5 (Cdk5) was also involved in the decrease of SIRT1 expression, which could be efficiently blocked by the inhibition of Cdk5. In conclusion, our findings revealed that the Cdk5-dependent ubiquitin-proteasome pathway mediated degradation of SIRT1 plays a vital role in the progression of PD.

[The significance, development and prospects of healthcare data integration in new drug clinical trials].

With the deployment of electronic medical records systems, more and more routine clinical data are recorded electronically, which become a potential data source for new drug clinical trials. In this paper, we summarized the opportunities, challenges, obstacles and the latest development in this field.

Investigation on Mechanism of Microstructure Evolution during Multi-Process Hot Forming of GH4169 Superalloy Forging.

Typically, in the manufacturing of GH4169 superalloy forgings, the multi-process hot forming that consists of pre-deformation, heat treatment and final deformation is required. This study focuses on the microstructural evolution throughout hot working processes. Considering that δ phase can promote nucleation and limit the growth of grains, a process route was designed, including pre-deformation, aging treatment (AT) to precipitate sufficient δ phases, high temperature holding (HTH) to uniformly heat the forging, and final deformation. The results show that the uneven strain distribution after pre-deformation has a significant impact on the subsequent refinement of the grain microstructure due to the complex coupling relationship between the evolution of the δ phase and recrystallization behavior. After the final deformation, the fine-grain microstructure with short rod-like δ phases as boundaries is easy to form in the region with a large strain of the pre-forging. However, necklace-like mixed grain microstructure is formed in the region with a small strain of the pre-forging. In addition, when the microstructure before final deformation consists of mixed grains, dynamic recrystallization (DRX) nucleation behavior preferentially depends on kernel average misorientation (KAM) values. A large KAM can promote the formation of DRX nuclei. When the KAM values are close, a smaller average grain size of mixed-grain microstructure is more conductive to promote the DRX nucleation. Finally, the interaction mechanisms between δ phase and DRX nucleation are revealed.

[Efficacy of modified Roux-en-Y gastric bypass in the treatment of non-obese type 2 diabetes mellitus:one year follow-up].

OBJECTIVE: To evaluate the one year effect of modified Roux-en-Y gastric bypass (RYGP) in the treatment of non-obese type 2 diabetes and to investigate the reasonable indications for surgery. METHODS: Totally 72 patients diagnosed as type 2 diabetes underwent RYGP from May 2009 to June 2010. There were 45 male and 27 female patients, with an average age of (47 ± 10) years. Preoperative body mass index (BMI) of the patients was 18.69 to 31.22 kg/m(2), average (26 ± 4) kg/m(2). The follow-up data included fasting plasma glucose (FPG), 2 h plasma glucose after oral glucose challenge (2hPG), weight, BMI and medication usage in 1, 3, 6 and 12 months postoperative; hemoglobin A1c (HbA1c), fasting C-peptide (C-P), fasting serum insulin (Fins) and homeostasis model assessment of insulin resistance index (HOMA-IR) in 6 and 12 months postoperative, respectively. RESULTS: Compared with the preoperative, FPG, 2hPG, weight and BMI in 1, 3, 6 and 12 months after surgery were improved (t = 7.014 to 10.254, P = 0.000), while HbA1c, C-P and HOMA-IR in 6 and 12 months after surgery were improved (t = 1.782 to 7.789, P = 0.000 to 0.103) and there was no significant difference in Fins (P > 0.05). The rates of complete remission in 1, 3, 6 and 12 months after surgery were gradually improved to 22.2%, 27.8%, 36.1% and 60.6%, respectively, and the rate of remission in 1 year was 94.3%. The complete remission of 1 year after surgery was associated with normal C-P, insulin antibody and oral antidiabetic drugs (χ(2) = 11.730, P = 0.003; χ(2) = 7.131, P = 0.028;χ(2) = 6.149, P = 0.046). CONCLUSIONS: Modified RYGP is safely and effectively in the treatment of no-obese type 2 diabetes patients. The function of islet cells is significantly improved after operation. Especially for the patients of whom C-P is normal, insulin antibody is negative before surgery, the rate of complete remission after 1 year is better.

Replacing permuted block design with big stick design in stratified randomization.

The PBD (Permuted Block Design) is the most widely used randomization method in clinical trials due to its comparatively simplicity. However, greater selection bias may appear, especially in open-labeled trials, because the PBD requires absolute balance at the end of each block . The BSD(Big Stick Design) method is one of the MTI(Maximum Tolerated Imbalance) procedures, which can make the allocation process more unpredictable while maintaining the advantages the PBD. So it is theoretically superior to the PBD method. However, some practical problems in stratified randomization hinder the application of the BSD method: such as the risk of serious imbalance for entire trials with the increasing of strata, the uncertainty of the reproducibility of randomization schedule, and the danger of greater selection bias in extreme cases. We propose solutions to the above three implementation problems, and explores the feasibility and effects of the solutions through simulations.

The role of the maximal first derivative of the radial pulse wave (Rad dP/dtmax) in monitoring cardiac function.

BACKGROUND: This study aimed to assess the clinical significance of the maximal first derivative of the radial pulse wave (Rad dP/dtmax) in monitoring cardiac function with different perioperative patients by researching the relationship between Rad dP/dtmax and cardiac output (CO). METHODS: Patients with non-pump coronary artery bypass grafting (CABG) and open liver tumor resection (OLTR) were enrolled in this study (n=10). CO was measured using the thermodilution Swan-Ganz catheter method and Rad dP/dtmax was acquired by the analysis of patients' left radial artery pressure waveform through the PowerLab data acquisition device. CO, Rad dP/dtmax, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure, central venous pressure, mean pulmonary arterial pressure, pulmonary artery wedge pressure (PAW), and body surface area was recorded. Data were analyzed using a mixed linear model of time-dependent covariates to duplicate the data. RESULTS: The bivariate correlation coefficients of Rad dP/dtmax and CO were 0.526 and 0.413. The result of the multivariate mixed linear model analysis showed that compared with other indicators, Rad dP/dtmax had the greatest standardized coefficient with CO in CABG patients. While in OLTR patients, HR, SBP, PAW, and DBP had larger standardized coefficients. CONCLUSIONS: Rad dP/dtmax could be a useful indicator to reflect and predict the acute changes in cardiac function in perioperative patients, especially for patients with cardiac dysfunction or contractility abnormality.

Locus coeruleus-CA1 projections are involved in chronic depressive stress-induced hippocampal vulnerability to transient global ischaemia.

Depression and transient ischaemic attack represent the common psychological and neurological diseases, respectively, and are tightly associated. However, studies of depression-affected ischaemic attack have been limited to epidemiological evidences, and the neural circuits underlying depression-modulated ischaemic injury remain unknown. Here, we find that chronic social defeat stress (CSDS) and chronic footshock stress (CFS) exacerbate CA1 neuron loss and spatial learning/memory impairment after a short transient global ischaemia (TGI) attack in mice. Whole-brain mapping of direct outputs of locus coeruleus (LC)-tyrosine hydroxylase (TH, Th:) positive neurons reveals that LC-CA1 projections are decreased in CSDS or CFS mice. Furthermore, using designer receptors exclusively activated by designer drugs (DREADDs)-based chemogenetic tools, we determine that Th:LC-CA1 circuit is necessary and sufficient for depression-induced aggravated outcomes of TGI. Collectively, we suggest that Th:LC-CA1 pathway plays a crucial role in depression-induced TGI vulnerability and offers a potential intervention for preventing depression-related transient ischaemic attack.

[Effect of mechanical ventilation with different tidal volumes on the respiratory function during general anesthesia].

OBJECTIVE: To determine the effect of mechanical ventilation with different tidal volumes on the respiratory function during general anesthesia and to seek optimum way and parameters of mechanical ventilation during general anesthesia. METHODS: Forty ASA I-II patients scheduled for elective craniotomies in the supine position were included in this study. According to latin square design, the patients were randomly divided into 4 groups. Every group has its own tidal volume sequence. Each patient used 4 tidal volumes in turn. Every tidal volume maintained 30 minutes. The rate of mechanical ventilation was 15. But ECG, blood pressure, heart rate, SPO2, ETCO2, airway pressure, lung compliance, and blood gas analysis were continuously monitored. RESULTS: A-aDO2, P(a-ET)CO2, P(PEAK), P(MEAN), P(PLAT), C(DYN), and C(STAT) significantly increased as the tidal volume increased (P<0.05). But ETCO2 and PaCO2 decreased as the tidal volume increased (P<0.05). PaO2, SPO2, MAP and HR had no significant difference between the 4 tidal volume groups(P>0.05). CONCLUSION: The optimum tidal volume of mechanical ventilation is not 4 mL/kg at the rate of 15 respiratory rate during general anesthesia in the supine position because of a high arterial carbon dioxide tension. Yet 6-8 mL/kg is better for neurosurgical anesthesia. Increasing the tidal volume alone may not improve the respiratory function impairment during general anesthesia.

[Epidural anesthesia with ropivacaine by computerized infusion pump].

OBJECTIVE: To explore the feasibility of epidural anesthesia with ropivacaine by computerized infusion pump. METHODS: Sixty patients scheduled for obstetric operation were divided into a continuous pump infusion group (Group A, n=30) and a conventional injection group (Group B, n=30). The initial doses of 0.75% ropivacaine 12 mL and 15 mL were respectively injected into the patient's epidural space in Group A and Group B. The dose of 6 mL of 0.75% ropivacaine per hour was continuously pumped to maintain the anesthesia till the end of the operation in Group A, and 6 mL of 0.75% ropivacaine was injected 80 min later in Group B. RESULTS: Blood pressure in some patients markedly decreased at 90 min after the first injection in Group B while it is relatively stable in Group A (P<0.05). The number of patients who had to inject ephedrine to raise the blood pressure in Group A was smaller than that in Group B during the operation (P<0.05). There was no significant difference in the anesthetic level between Group A and Group B (P>0.05). CONCLUSION: Epidural anesthesia with ropivacaine by computerized infusion pump is safe, which can not only provide an excellent anesthetic effect but also keep the hemodynamics stable.

[Effect of different tidal volume ventilations on atelectasis in patients during general anesthesia by CT scan].

OBJECTIVE: To investigate the effect of different tidal volume ventilations on the amount of atelectasis during general anesthesia. METHODS: Twenty adults, ASA physical status I and status II patients, who were scheduled for elective excision of intracranial lesion were randomly divided into 2 groups: Group TV (traditional tidal volume ventilation, 10 mL/kg) and Group LV (low tidal volume ventilation, 6 mL/kg). Atelectasis, as determined by CT and artery blood gas (ABG) analysis, was measured before the anesthesia, after the tracheal intubation, and at the end of the operation, respectively. Respiratory mechanical parameters were measured at 30, 120, and 240 min after the intubation. RESULTS: After the tracheal intubation, CT scan showed obvious atelectasis in both groups. The atelectasis area was(4.35+/-2.15)cm2 (3.12%+/-1.94%) in the TV group and (4.80+/-2.45)cm2 (3.89%+/-2.11%) in the LV group, with a nonsignificant difference between the 2 groups. At the end of the operation, there was no significant increase in the amount of atelectasis between and within the 2 groups. Artery blood gas analysis showed no difference after the tracheal intubation and at the end of the operation in either group. Ppeak, Pplat, Pmean and lung compliance(Cst)were significantly higher in the TV group than those in the LV group. CONCLUSION: Low tidal volume(6 mL/kg) ventilation is more feasible during general anesthesia in patients with healthy lungs, and it does not increase the atelectasis and impairment of gas exchange.

Impact of different analgesic depths and abdominal trauma of different severities on stress and recovery of rats undergoing total intravenous anesthesia.

A number of animal models have been developed to examine the pathophysiological consequences of surgical procedures, but anesthetic methods, monitoring, and management measures in these models are very different from those used in humans. This study was designed to create a rat model of abdominal surgery using anesthetic methods and perioperative treatment similar to those used in the clinic and to investigate the effects of different injury severities and depths of anesthesia and analgesia on surgical stress and postoperative recovery. Abdominal skin/muscle incision was compared with exploratory laparotomy in rats under propofol intravenous anesthesia, accompanied by perioperative measures such as oxygen inhalation, fluid infusion, warmth, blood gas analysis, and infection prevention. Stress indices (mean arterial pressure, heart rate, blood glucose, and plasma corticosterone) were monitored during anesthesia and surgery, and recovery indicators (body weight, food consumption, and pain) were measured after surgery. In addition, animals undergoing laparotomy were subjected to low and high dosages of propofol and sufentanil, in order to examine the relationship between anesthetic and analgesic depth and stress on recovery. Exploratory laparotomy induced a greater stress response and caused slower postoperative recovery as measured than somatic injury. High-dose sufentanil downregulated plasma corticosterone and improved postoperative recovery more effectively than high-dose propofol (P<0.05). Taken together, a rat model of abdominal surgery using anesthetic methods and perioperative treatment similar to those used in the clinic was successfully developed. It showed a positive correlation between severity of surgical trauma and stress response and postoperative recovery and a significant role of adequate analgesia in reducing surgical stress and improving postoperative recovery.

CDK5-mediated phosphorylation of XBP1s contributes to its nuclear translocation and activation in MPP+-induced Parkinson's disease model.

Parkinson's disease (PD) is an irreversible and progressive neurodegenerative disorder characterized by the selective loss of dopaminergic neurons of the substantia nigra pars compacta. Growing evidence indicates that endoplasmic reticulum stress is a hallmark of PD; however, its exact contribution to the disease process remains poorly understood. Here, we used molecular biology methods and RNA-Seq analysis to explored an unexpected role of spliced X-Box binding protein 1 (XBP1s) in the nervous system. In this study, we determined that the IRE1α/XBP1 pathway is activated in MPP+-treated neurons. Furthermore, XBP1s was identified as a substrate of CDK5 and that the phosphorylation of XBP1s at the Ser61 residue enhances its nuclear migration, whereas mutation of the residue to alanine substantially reduces its nuclear translocation and activity. Importantly, phosphorylated XBP1s acts as a nuclear transcription factor for multiple target genes, including metabolic-related genes, FosB, and non-coding RNAs. Our findings confirm that the IRE1α/XBP1 pathway is activated in PD, and reveal a novel role of XBP1s in the pathogenesis of PD. This pathway may be a new therapeutic strategy for PD.

[Influences of perioperative metoprolol on hemodynamics and myocardial ischaemia in elderly patients undergoing noncardiac surgery].

OBJECTIVE: To observe the influences of metoprolol on hemodynamics and myocardial ischaemia in elderly patients undergoing noncardiac surgery. METHODS: Thrity patients (60 approximately 75 years) undergoing elective noncardiac surgery were randomly divided into a metoprolol group (n = 15) and a control group (n = 15). In the metoprolol group, metoprolol (0. 5 mg and 1.5 mg) was slowly injected into the vein of patients before the induction of intravenous anesthesia and after the tracheal intubation. The hemodynamic indice (invasive BP, HR and rate pressure product-RPP), the myocardial ischaemia indice (reversible ST segment depression of ECG II, V5 leads more than 0.1 mv or reversible ST segment elevation more than 0.2 mv from the baseline, ST segment depression or elevation over 1 min), the myocardial damage indice (serum cardiac troponin I, cTn I), and the indice of metoprolol cardiac and the respiratory adverse effects (incidence of HR below 50 beats/min, average doses of atropine, airway peak pressure) were observed intraoperatively. RESULTS: The HR and RPP were lower before the tracheal induction than the baseline (before anesthesia) in all patients, but there is no significant difference between the two groups (P > 0.05). During the tracheal intubation, the HR and RPP of the control group significantly increased, compared with the baseline (P < 0.05) and those of metoprolol group (P < 0.05). The incidence of perioperative hypertension was higher in the control group than that in the metoprolol group. The incidence of myocardical ischaemia episode was 30% in the control group, and 13% in the metoprolol group (P < 0.01). The release of cTn I was detected in 5 patients in the control group, and 2 patients in the metoprolol group (P < 0.05). The incidence of HR < 50 beats/min, and the average doses of atropine had no statistic difference between the two groups, but a tendency of high incidence of bradycardia in the metoprolol group occurred when abdominal viscera was tracted by surgical manupilation. There was no significant difference in airway peak pressure, SpO2 and PET CO2 between the two groups (P > 0.05). CONCLUSION: Intravenous administration of 0.5 mg and 1. 5 mg metoprolol before the induction of anesthesia and after the tracheal intubation has several advantages, including the decrease of myocardial oxygen consumption, the improvement of hemodynamic stability, and the lowering perioperative incidence of myocardial ischeamia and damage, but the tendency of high bradycardia incidence caused by peritoneal traction should be noticed.

[Effects of different mechanical ventilation methods on oxygenation and shunt fraction in patients undergoing valve replacement].

OBJECTIVE: To determine the effects of different mechanical ventilation on oxygenation and shunt fraction in patient undergoing valve replacement. METHODS: Thirty ASA II-III patients (12 males, 18 females), aged 25-56 years, undergoing valve replacement were randomly divided into 3 groups according to the mechanical ventilation method. Anesthesia was induced with midazolam 0.1 mg/kg, fentanl 10 microg/kg,vecuronium 0.1 mg/kg,and etomidate 0.3 mg/kg. Valve replacement was performed with moderate hypothermic cardiopulmonary bypass( CPB). The patients were mechanically ventilated with pure oxygen and I:E ratio 1:2. Group A (TV = 7 ml/kg, f=12 bpm) ,Group B (TV=5 ml/kg, f=15 bpm), and Group C (TV=7 ml/kg, f=15 bpm). ECG, BP, SPO2, and CVP were routinely monitored. Blood samples were taken from the radial artery and pulmonary artery at 30 min after the induction of anesthesia, 10 min before CPB, and the end of operation for blood gas analysis. Respiratory index (P(A-a) DO2/PaO2), and Qs/Qt were calculated. RESULTS: There was no significant difference in age, weight, duration of operation of CPB time and aortic cross-clamping time among the 3 groups. At the end of operation, PaO2 decreased significantly, P (A-a)DO2, RI, and Qs/Qt increased significantly in group A, while there was no significant change in group B and group C. At the end of the operation, PaCO2 was lower than the baseline value (< 35 mmHg) in Group A, but it was normal in Group B and group C. CONCLUSION: The mechanical ventilation method of lower tidal volume and higher respiratory rate might increase the oxygenation and decrease shunt fraction and might be more suitable in patients undergoing valve replacement.

[Effect of ulinastatin on lung injury after dilute hydrochloric acid aspiration].

OBJECTIVE: To determine the effect of ulinastatin (UTI) on blocking the development of acute lung injury (ALI) induced by acid aspiration in the early period. METHODS: The SD rats were randomly divided into 3 groups: control group (n = 10), injury group (n = 10), and UTI-treated group (n = 10). The rats in the control group were injected intrabronchialy saline while the other 2 groups were injected HCl. The UTI-treated group was injected UTI at 4 x 10(4) U/kg after acid instillation. Blood gas as well as wet/dry weight ratio (W/D) of the left lung was measured. The changes of IL-8 and TNF-alpha levels in the pulmonary tissues were determined by enzyme-linked immunosorbent assay. RESULTS: The result of blood gas analysis in the UTI-treated group was much better than that in the injury group (P < 0.01). W/ D and IL-8, TNF-alpha levels were lower in the UTI-treated group than those in the injury group significantly (P < 0. 01), and there was no difference between the UTI-treated group and the control group in IL-8 and TNF-alpha levels (P > 0. 05). CONCLUSION: UTI administration can lessen the development of ALI induced by acid aspiration in the early period.