Objective To establish a sensitive,valid and rapid high performance liquid chromatography-trap mass spectrometry (HPLC-MS) method for determining carbocisteine concentration in human plasma. Methods Plasma samples were pretreated by 100 mL/L perchloric acid to remove the interference protein. The supernatant was separated by reverse phase HPLC,electrospray MS was used to detect carbocisteine in plasma samples,and selective ion method of multiple reaction modes was used to determine the concentration of carbocisteine. Results The limit of detection was 0.01 ?g/mL and the linear range was 0.2-200.0 ?g/mL. The recovery rate was within the range of 89.2%-105.6%. Conclusion The proposed method could be used to determine carbocisteine in biological samples.

Objective　To evaluate the effectiveness of intratracheal tube suctioning by respiratory mechanics measurement.Methods　The indexes of respiratory mechanics,including respiratory rate,expiratory tidal volume,% leak around the tube,dynamic respiratory compliance and mean airway resistance were measured just before and 20 minutes after intraendotracheal tube suction in mechanical ventilated children with respiratory failure.Results　Fifty-two measurements was carried out in 11 patie nts.The mean values of respiratory risistance was (116.73±27.12)cmH2O/L.s before suctioning and (93.38±26.64)cmH2O/L.s after suctioning,with significant differrence(P＜0.01)；The mean values of % leak around the tacheal tube dereased from(18.12±4.12)% before suctioning to (8.71±3.76)% after suctioning (P＜0.05),The mean values of expiratory tidal valume was markedly increased from(7.31±2.12)ml/kg before suctioning to(5.72±1.2)ml/kg after suctioning(P＜0.01),The total respiraory rate markedly decreased after suctioning.Conclusion　The respiratory mechanics measurement is very useful to evaluate the airway patient.The removal of secretions is crucial in respiratory managemet.

BACKGROUND:Oligodendrocytes are mostly differentiated from oligodendrocyte precursor cel s. A suitable medium and cel seeding density have a significant impact on the process of the isolation of oligodendrocyte precursor cel s to obtain oligodendrocytes. OBJECTIVE:To explore the optimization of oligodendrocyte culture conditions. METHODS:Oligodendrocyte precursor cel s isolated from the newborn rats 48 hours after birth were cultured in DMEM/high glucose medium or DMEM/F12 medium using seeding densities of 2×104 cel s/cm2, 4×104 cel s/cm2, 8×104 cel s/cm2, 16×104 cel s/cm2, 32×104 cel s/cm2, and 64×104 cel s/cm2, respectively. Oligodendrocyte precursor cel s were induced to differentiate into oligodendrocytes at 72 hours after cel adhesion. Morphology of differentiated oligodendrocyte precursor cel s were observed under a light microscope, and the differentiation results were identified by immunofluorescence staining after 7-day induced differentiation. RESULTS AND CONCLUSION:Morphology of oligodendrocyte precursor cel s were recognized when cultured in DMEM/high glucose medium or DMEM/F12 medium using seeding densities of 2×104 cel s/cm2, 4×104 cel s/cm2, and 8×104 cel s/cm2, respectively. Immunofluorescence staining showed that myelin basic protein-positive cel s were found after 7-day induced differentiation, and the positive cel number were 16.40±3.30, 49.95±2.33, and 76.95±4.86 in DMEM/F12 medium, and 12.65±2.53, 32.10±1.17, and 54.05±1.56 in DMEM/high glucose medium (P<0.05). These findings indicate that DMEM/F12 medium is more suitable for culturing oligodendrocyte precursor cel s compared with DMEM/high glucose medium to some extent. The number of differentiated oligodendrocytes was gradual y increased with the enhanced seeding density of oligodendrocyte precursor cel s, and the seeding densities from 4×104 to 8×104 cel s/cm2 were appropriate for the observation of cel morphology.

Objective To approach the effect of health education pathway in rehabilitation of children with cerebral palsy (CP).Methods 240 CP children were divided into the trial group (120 cases) daily practiced by duty nurse according to health education pathway table and evaluated in time, and control group (120 cases) guided by routine Methods . Then, the two groups were compared in the rate of achieving standard and the variation in the course of health education.Results The attendants in the trial group knew more about CP, and their acceptance of prognosis, quality of living, rehabilitation effect and health education effect were better than the other group, the variation decreased significantly in the trial group.Conclusion The procedure and standard of health education can decrease the occurrence of hospital infection, increase the confidence of the attendants, and put the staff and patients in harmony.

Directed evolution of transcription factors can be employed to effectively improve the phenotypes which are controlled by multiple genetic loci. In this study, we used error-prone PCR for the directed evolution of SPT3, which is the component of yeast Spt-Ada-Gcn5-acetyltransferase (SAGA) complex responsible for the transcription of stress-related genes, and studied its effect on the improvement of ethanol tolerance. Mutant library was constructed by ligating the error-prone PCR products with a modified pYES2.0 plasmid, and the expression plasmids were subsequently transformed to yeast industrial strain Saccharomyces cerevisiae 4126. One mutant strain M25 showing superior growth in presence of 10% ethanol was selected. M25 produced 11.7% more ethanol than the control strain harboring the empty vector when 125 g/L glucose was used as substrate. This study revealed that SPT3 is an important transcription factor for the metabolic engineering of yeast ethanol tolerance.
Directed Molecular Evolution ; methods ; Drug Resistance, Fungal ; Drug Tolerance ; Ethanol ; metabolism ; pharmacology ; Industrial Microbiology ; methods ; Saccharomyces cerevisiae ; drug effects ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; genetics ; Trans-Activators ; genetics ; Transcription Factors ; genetics

Objective:To investigate the efficacy of endoscopic histoacryl injection in cirrhotic patients with newly-developed esophagogastric varices (EGV) who have previously undergone splenectomy combined with pericardial devascularization.Methods:From January 2015 to January 2020, 125 cirrhotic patients with EGV treated with endoscopic histoacryl injection at the Department of Gastroenterology, Jinling Hospital, Medical School of Nanjing University, were included in the retrospective analysis. There were 45 patients in the group of splenectomy combined with pericardial devascularization (splenectomy group for short) and 80 patients in the non-splenectomy group. The efficacy of endoscopic treatment, postoperative variceal improvement, rebleeding rate, and complications were analyzed between the two groups.Results:Endoscopic histoacryl injection was successfully completed in all 125 patients, and the median volume of histoacryl was 4.5 mL. The overall effective rate in splenectomy and non-splenectomy group was 80.0% (36/45) and 57.5% (46/80), respectively. The difference in the number of significantly effective, effective, and ineffective cases between the two groups was statistically significant (16, 20, 9 cases, and 20, 26, 34 cases, respectively, χ 2=6.469, P=0.039). Two and 14 patients developed rebleeding in the splenectomy group and non-splenectomy group, respectively; and the difference in the rebleeding rate between the two groups was statistically significant (4.4% VS 17.5%, Log-rank P=0.039). No patient died within 1 year in either group, and no serious complications such as ectopic embolism occurred. Conclusion:After splenectomy combined with pericardial devascularization in cirrhotic patients with EGV and hypersplenism, the application of histoacryl has better short-term efficacy and can significantly reduce the rebleeding rate compared with the non-splenectomy group.

Objective:To investigate the improved performance of hepatic elastography combined with the serum biomarkers for the diagnosis of biliary atresia.Methods:A total of 193 patients with suspected biliary atresia in Beijing Children′s Hospital from March 2019 to November 2020 were consecutively collected. All patients were randomly divided into the training cohort and validation cohort at a ratio of 7∶3. LASSO regression analysis was used for the selection of the model index based on the data set from the training cohort including the serum biomarkers, demographic features (age and sex) and hepatic elastic measurement, and a diagnostic model for biliary atresia was subsequently developed by weighting on the basis of the dominance ration. The performance of the model was respectively evaluated with respect to the discrimination and calibration in each cohort.Results:Alanine aminotransferase (ALT), glutamyl transferase (GGT) and hepatic elastic measurement were selected to build the model. The area under the ROC curve of the final diagnostic model was 0.943 with a sensitivity of 90.9% and a specificity of 85.7% in the training cohort, and 0.955 in the validation cohort. Hosmer-Lemeshow test ( P=0.292, P=0.951) and calibration curves further validated its satisfactory calibration in both cohorts. As demonstrated by Delong et al.test, employing the model in the training cohort achieved the best diagnostic performance compared with using single model index ( P<0.001, P=0.016, P<0.001). In the validation cohort, the decision curve analysis showed the model had a higher overall net benefit over using hepatic elastography alone in every predicted probability. Conclusions:The diagnostic model for biliary atresia, which incorporates ALT, GGT and hepatic elastic measurement, can improve the performance of hepatic elastography with a higher clinical value.

The development and implement of microbial chassis cells can provide excellent cell factories for diverse industrial applications, which help achieve the goal of environmental protection and sustainable bioeconomy. The synthetic biology strategy of Design-Build-Test-Learn (DBTL) plays a crucial role on rational and/or semi-rational construction or modification of chassis cells to achieve the goals of "Building to Understand" and "Building for Applications". In this review, we briefly comment on the technical development of the DBTL cycle and the research progress of a few model microorganisms. We mainly focuse on non-model bacterial cell factories with potential industrial applications, which possess unique physiological and biochemical characteristics, capabilities of utilizing one-carbon compounds or of producing platform compounds efficiently. We also propose strategies for the efficient and effective construction and application of synthetic microbial cell factories securely in the synthetic biology era, which are to discover and integrate the advantages of model and non-model industrial microorganisms, to develop and deploy intelligent automated equipment for cost-effective high-throughput screening and characterization of chassis cells as well as big-data platforms for storing, retrieving, analyzing, simulating, integrating, and visualizing omics datasets at both molecular and phenotypic levels, so that we can build both high-quality digital cell models and optimized chassis cells to guide the rational design and construction of microbial cell factories for diverse industrial applications.
Bacteria/genetics* ; Metabolic Engineering ; Synthetic Biology