Although heterologous biosynthesis of polyketide erythromycin has been successfully achieved in Escherichia coli, the titer remains at a very low level (-10 mg/L). In this study, based on genome-scale metabolic model of E. coli, in silico method flux distribution comparison analysis was used to discover novel potential targets for heterologous 6-dEB biosynthesis. Synthetic small regulatory RNAs (sRNAs) was used to experimentally test 12 down-regulated targets. The results showed that repression of each of these target genes e.g. lsrC and ackA led to significantly improve heterologous 6-dEB biosynthesis. Using co-repression of lsrC and ackA, 6-dEB titer was improved by 59.9% in shake-flask with a maximum yield of 22.8 mg/L. This study indicates that combined flux distribution comparison analysis and synthetic small regulatory RNAs is an effective strategy to improve 6-dEB production in E. coli.
Down-Regulation ; Erythromycin ; biosynthesis ; Escherichia coli ; genetics ; metabolism ; Industrial Microbiology ; methods ; RNA

AIM: To observe the effects of Salvia miltiorrhiza Bunge.f.alba. (Sal) on the mitochondrial ultra-structure, oxidative stress and apoptosis induced by ischemia injury in a rat model of focal cerebral ischemia and reperfusion.METHODS: The middle cerebral artery occlusion/reperfusion (MCAO/R) rat model was established by a modified Longa occlusion method. Adult male SD rats were randomly divided into control group, simple ischemia reperfusion group, Sal with ischemia reperfusion group and butylphthalide with ischemia reperfusion group. To study the protective effects of Sal and its mechanism, the intervention of Sal was given and the ultra-structure of mitochondria, functions of mitochondria under oxidative stress and the incidence of apoptosis of brain cells were determined.RESULTS: Many electron dense toxic granulation and vacuolus in mitochondria were observed in the rat brain of focal cerebral ischemia and reperfusion. Under the condition of ischemia and reperfusion, the mitochondria membrane was disaggregative, and the tubular cristae of mitochondrion disappeared. MDA content was obviously increased and the activity of glutathione peroxidase decreased significantly. The apoptosis of brain cells were observed in a great quantity. The changes of ultra-structure of mitochondria and the activity of GSH-Pxase were significantly improved by the treatment of Sal. Furthermore, treatment with Sal delayed the decrease of GSH-Pxase activity, and inhibited the increase in MDA content in brain tissue after ischemia and reperfusion. The incidence of apoptosis of brain cells was also decreased.CONCLUSION: Sal protects the brain tissue from ischemia injury.

BACKGROUND: Many scholars have reported the study of genetic polymorphism of short tandem repeat loci in different countries, areas, and population. But what is the genetic polymorphism of short tandem repeats loci of Chinese Korean is still unknown.OBJECTIVE:To investigate the distribution of the genetic polymorphism of D16S539 D7S820, D13S317, CSF1PO, TPOX and TH01 in Chinese Korean, obtain the crowded genetic data of corresponding polymorphism loci.DESIGN: Single sample observation.SETTING: Staff Room of Biology, Department of Detecting and Analyzing DNA, Mudanjiang Medical College.MATERIALS: Periphoral blood samples from 100 unrelated individuals in Korean of Mudanjiang were chosen from January 2001 to February 2001.METHODS: Genotype detection was performed in one hundred unrelated individuals with polymerase chain reaction amplification fragment length polymorphism analysis.MAIN OUTCOME MEASURES: Sample genotype of D16S539,D7S820, D13S317, CSF1PO, TPOX, THO1 6 short tandem repeat loci.TH01 locus.CONCLUSION: The genotypes distributions of the 6 short tandem repeat (STR) in Chinese Korean met Hardy-Weinberg equilibrium, and have higher heterozygosities. The gene frequency and other data obtained can provide the basis for studying the crowded genetics of Chinese Korean.

Objective The study was to find the application effect of high quality nursing service in perioperative treatment of patients with coronary heart disease.Methods Eighty patients were randomly divided into the comfort nursing group and the routine nursing group with 40 patients in each group.The comfort nursing group was given high quality nursing service,and the routine nursing group received the conventional care.The effect in two groups was compared after rehabilitation.The statistical software of SPSS 17.0 was used to analyze the data.Results The degree of anxiety was lower,the number of patients with complication was less,the degree of satisfaction was higher and the time in hospital was less in the comfort nursing group.Conclusions The comfortable nursing care should be used in peri-operative treatment of coronary heart disease,which can make patients keep the best mental state to accept and cooperate with the surgical treatment.It also can improve the care quality and patients' satisfaction degree and shorten the hospital stay.

Objective:To study the combined use of endoscopic balloon dilation with endoscopic biliary brushings in diagnosis of bile duct strictures.Methods:A prospective single center study was conducted at the Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology. All patients with suspected malignant bile duct strictures shown on CT or MRI imaging from January 2018 to January 2020 were reviewed. All patients gave informed consent to the endascopic retrograde cholangiopancreatography procedures. Their clinical and follow-up data were analyzed. All patients underwent endoscopic balloon dilation of bile duct strictures. Before and after balloon dilation, biliary brush cytology was performed, and the results were used to classify the patients into the control group and the experimental group. Pathological examination of the brush cytology samples was carried out by a single chief pathologist. Presence of cancer cells or significant heterogeneous cells indicated a positive brush cytology test. Negative patients who still highly consider cholangiocarcinoma and agree to surgery and whose gross specimen is confirmed to be malignant after surgery should be considered as false negative by brush examination; it is difficult to judge that patients with cholangiocarcinoma have progress after 2 months of follow-up should be considered as false negative by brush examination. Any progression of disease indicated that the brush test was wrong and the test was again classified as false negative. Only when there was no progression of strictures was the possibility of a benign biliary stricture being considered. The advantage test (McNemar test) was used to analyze the difference between the two diagnostic methods.Results:Of 39 patients who were included in this study, there were 26 males and 13 females, with an age of (68.0 ± 5.2) years. Cholangiocarcinoma was diagnosed by histopathology, surgery or at 2 months follow-up in 35 patients. In the control group, 17 patients had a positive brush test (sensitivity rate was 48.6%, 17/35). In the experimental group, 26 patients had a positive brush test (sensitivity rate was 74.2%, 26/35). In addition, 2 patients in the control group had a positive brush test, while in the experimental group, a negative brush test. A total of 28 patients were positive in the two groups. The sensitivity rate of the brush test was 80.0% (28/35). There were significant differences between the two groups ( P<0.05). Conclusion:Endoscopic balloon dilation combined with endoscopic biliary brushings improved the sensitivity of pathological diagnosis of cholangiocarcinoma, and endoscopic biliary brushings before and after balloon dilation improved the sensitivity of diagnosis.

AIM:To explore the changes of plasma levels of soluble vascular endothelial growth factor receptor 2 ( sVEGFR2) and superoxide dismutase ( SOD) in hypertensive patients and hypertensive diabetic patients.METHODS:In this cross-sectional study, 88 cases were enrolled, which were divided into hypertensive group (n=31), hypertensive diabetic group ( n=31 ) and control group ( n=26 ) .Blood pressure was obtained from each participant with mercury sphygmomanometer.The levels of sVEGFR2 and SOD were measured by ELISA.Meanwhile, the levels of plasma glucose, glycosylated hemoglobin A1c ( GHbA1c) and lipid profile were detected.RESULTS:The levels of total cholesterol ( TC) and body mass index (BMI) were significantly higher in hypertensive group than those in control group (P<0.05).The levels of TC, low-density lipoprotein cholesterol ( LDL-C) , triglyceride ( TG) , BMI, waist circumference were significantly higher in hypertensive diabetic group than those in control group (P<0.05).The plasma levels of sVEGFR2 and SOD in both hypertensive diabetic group and hypertensive group were significantly decreased compared with control group ( P<0.05), while the mean plasma levels of sVEGFR2 and SOD in hypertensive diabetic group were significantly decreased compared to the hypertensive group ( P<0.05 ) .A significantly positive correlation between sVEGFR2 and SOD in the whole study population (P<0.05) was observed.CONCLUSION: The plasma level of sVEGFR2 is decreased in both hypertensive and hypertensive diabetic patients, and more significantly decreased in hypertensive diabetic patients.De-creased SOD level may be associated with to the reduction of sVEGFR2.

OBJECTIVETo analyze genetic polymorphism of D16S539 D7S820 D13S317 CSF1PO TPOX and TH01 in Chinese Korean.

METHODSOne hundred unrelated individuals were analyzed by PCR amplification fragment length polymorphism analysis.

RESULTSSix alleles and 18 genotypes of D16S539 locus, 7 alleles and 22 genotypes of D7S820 locus, 7 alleles and 23 genotypes of D13S317 locus, 6 alleles and 16 genotypes of CSF1PO locus, 6 alleles and 11 genotypes of TPOX locus, 5 alleles and 12 genotypes of TH01 locus.

CONCLUSIONThe genotype distribution of all the 6 short tandem repeat(STR) in Chinese Korean met Hardy-Weinberg equilibrium, and have higher heterozygosities. The data obtained can be used in human identity and paternity testing, and in other genetic researches and population investigation.

Alleles ; China ; DNA ; genetics ; Gene Frequency ; Genotype ; Humans ; Korea ; ethnology ; Polymorphism, Genetic ; genetics ; Tandem Repeat Sequences ; genetics

Objective To investigate the clinical and pathological characteristics of the extrapleural solitary fibrous tumor and the relevant differential diagnosis.Methods HE and immunohistochemical staining were performed on 26 samples of isolated fibrous tumors outside the pleura,and a comprehensive analysis was conducted based on the clinical and imaging data.Results The histological morphology of isolated fibrous tumors was diverse,with typical cases showing the irregular arrangement of oval or spindle shaped cells.In the stroma,thick collagen bands,antler like blood vessels,and peritubular transparent degeneration could be seen.The immunohistochemical staining demonstrated that the positive rates of STAT-6、CD34、Bcl-2、CD99、SMA were 96.2% 、92.3% 、92.3% 、76.9% and 26.9%,respectively.Conclusion SFT commonly occurs in the pleura and can also occur in other areas.Its histological characteristics and immunohistochemical phenotype help to clarify the diagnosis.However,when it occurs in uncommon anatomical sites,it is necessary to carefully and meticulously distinguish and comprehensively judge the clinical prognosis of key diseases that need to be distinguished or excluded..

AIM: To explore the effect of hydrogen sulfide on the senescence of human umbilical vein endothe -lial cells (HUVECs) induced by high glucose.METHODS: Senescence model was established by treating HUVECs with33 mmol/L glucose for 48 h.The parameters were detected to demonstrate the effect of hydrogen sulfide on senescence andthe mechanism involved was also investigated .RESULTS: In the cells treated with high glucose, the proliferation was attenuatedwith a higher number of senescence -associated β-galactosidase (SA-β-Gal) positive cells, and plasminogen activatorinhibitor 1 (PAI-1) protein expression, malondialdehyde (MDA) production and NF-κB p65 activity were increasedsignificantly, but the expression of superoxide dismutase 1 (SOD1) was decreased.However, the cell number and SOD1expression were increased, and the number of SA-β-Gal positive cells, PAI-1 protein expression, MDA production and theactivity of NF-κB p65 were decreased after sodium hydrosulfide (100 and 200 μmol/L) treatment.CONCLUSION: Exogenoushydrogen sulfide prevents HUVECs against high glucose -induced senescence by suppressing oxidative stress and NF -κB p65 activity.

Objective:To investigate and evaluate the efficacy of HeartCon left ventricular assist device (LVAD) in the treatment of adult patients with end-stage heart failure (ESHF).Methods:A prospective and observational study was conducted. Patients with ESHF who underwent LVAD implantation in the department of cardiac surgery of Teda International Cardiovascular Hospital from September 2020 to August 2021 were selected. The left ventricular end-diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) classification, N-terminal pro-B type natriuretic peptide (NT-proBNP), and six minute walk distance (6MWD) before operation and 90 days after operation were compared. The incidence of equipment failures and major adverse events within 90 days after operation were recorded.Results:A total of 20 patients with ESHF were included, with 15 males and 5 females. Patients' age ranged from 20 to 67 years old, with an average of (50.2±13.6) years old. The range of body weight was 49.8-106.1 kg, with an average of (67.9±15.5) kg, and the body surface area (BSA) was from 1.49 to 2.32 m 2, with an average of (17.6±0.22) m 2. The operation process of all the patients were successful. The length of hospital stay ranged from 33 to 90 days, and the average was 56.0 (42.8, 75.0) days. Complications within 90 days after operation as follows, 2 cases with pericardial tamponade (10%), 1 case with cerebral hemorrhage (5%), 1 case with mediastinum infection (5%), 3 cases with acute renal injury (AKI, 15%), 5 cases with gastrointestinal bleeding (25%). There were no mechanical failure of LVAD and hemolysis events, right ventricular failure (RVF), cerebral infarction and death occurred. Compared with preoperative, the LVEDD significantly decreased (mm: 67.50±13.98 vs. 77.40±9.73), LVEF significantly increased (%: 34.80±9.76 vs. 22.70±5.62), NT-proBNP significantly decreased (ng/L: 2 028.65±1 752.05 vs. 4 796.45±4 355.40), 6MWD significantly increased (m: 385.20±144.12 vs. 85.81±63.50) at 90 days after operation, and the differences were statistically significant (all P < 0.05). 18 cases (90%) of the 20 patients reached NYHA classification Ⅰ and 2 cases (10%) reached NYHA classification Ⅱ, which were significantly improved compared with those before surgery (all patients' NYHA classification were Ⅳ before surgery). Conclusion:HeartCon LVAD can effectively improve the life quality of patients with ESHF, which has been proved safe and effective in clinical trials, but its long-term effects and complications need further observation and study.