Establishment and validation of a model for predicting recurrent wheezing in children with bronchiolitis / 中国医师进修杂志

Objective:To analyze the risk factors of recurrent wheezing in children with bronchiolitis and to construct a predictive model.Methods:Prospective research methods was used. One hundred and eighty children with bronchiolitis who were treated in Hefei Eighth People's Hospital from February 2017 to February 2019 were selected as the study subjects, and the included children were separated into a modeling group (126 cases) and a validation group (54 cases) according to 7∶3. The children were followed up for 3 years, and then the modeling group was divided into wheezing group (48 cases) and no wheezing group (78 cases) according to whether the children had recurrent wheezing. The Hosmer-Lemeshow fitting curve and receiver operating characteristic (ROC) curve were drawn to evaluate the validity and accuracy of the constructed prediction model.Results:Multivariate Logistic regression analysis showed that artificial feeding ( OR = 8.838, 95% CI 2.601 to 30.027), family history of allergies ( OR = 6.709, 95% CI 1.825 to 24.665), underlying diseases ( OR = 8.114, 95% CI 1.638 to 40.184), and higher IgE level ( OR = 1.020, 95% CI 1.012 to 1.029) were the independent risk factors for recurrent wheezing in children with bronchiolitis ( P<0.05). The area under the curve of the modeling group was 0.917 (95% CI 0.855 to 0.959), and the sensitivity and specificity were 83.33% and 85.90%, respectively; the area under the curve of the validation group was 0.911 (95% CI 0.847 to 0.954), and the sensitivity and specificity were 89.58% and 79.49%, respectively. Conclusions:Artificial feeding, family history of allergies, underlying diseases, and higher IgE level are the independent risk factors for recurrent wheezing in children with bronchiolitis. The constructed prediction model has good accuracy and validity, and can be used as an effective tool for clinical prediction of recurrent wheezing in children with bronchiolitis.

Effects of directional adaptation on selenium tolerance and accumulation of heterotrophic Chlorella pyrenoidosa / 生物工程学报

Selenium (Se) is an essential trace element for organisms. Se deficiency will cause diseases such as Keshan disease and Kashin-Beck in human being, and huge loss to animal husbandry. Currently available Se supplements have such problems as low Se content, poor bioavailability, and poor safety. Chlorella pyrenoidosa can produce bioavailable and safe organic Se under suitable conditions, which is thus a promising Se supplement. Therefore, in this study, we tried to improve the Se tolerance and accumulation of C. pyrenoidosa by directional adaptation. To be specific, we gradually increased the concentration of Na2SeO3 in medium to domesticate C. pyrenoidosa and optimized the adapting time and concentration gradient of Na2SeO3 during the adaptation. The results showed that the adapted C. pyrenoidosa was more tolerant to Se and had stronger Se enrichment ability. In 5 L fermenter, the adapted strains could tolerate 40 mg/L Na2SeO3 and the synthesis rate of organic Se was 175.6% higher. Then, Se addition method in the 5 L fermenter was optimized. The result demonstrated that addition of Na2SeO3 at 40 mg/L during heterotrophic culture achieved the final dry weight of C. pyrenoidosa cells at 106.4 g/L, content of organic Se at 1 227 mg/kg, and synthesis rate of organic Se at 1.36 mg/(L·h). Compared with the reported highest cell density of 75 g/L and the highest organic Se content of 560 mg/kg, the corresponding figures in this study were 41.9% and 119.1% higher, respectively. In conclusion, directional adaptation can remarkably improve the Se tolerance and enrichment of C. pyrenoidosa.

Research progress of metformin in non-Hodgkin lymphoma / 国际肿瘤学杂志

Preclinical studies have shown that metformin, an activator of AMP-activated protein kinase (AMPK) , can inhibit the growth of lymphoma cells without affecting the function of normal lymphocytes, promote the apoptosis of lymphoma cells and improve the tumor immune environment. Clinical studies have shown that metformin can improve the efficacy of chemotherapy and prognosis of non-Hodgkin lymphoma (NHL) . Through the influence on glucose metabolism, it can improve blood glucose level and reduce the incidence of steroid diabetes. The main molecular mechanisms of metformin against NHL include activating AMPK in tumor cells, inhibiting mammalian target of rapamycin signal, inhibiting key cholesterol synthesis, improving glucose metabolism, enhancing highly cytotoxic T lymphocyte (CTL) activity and so on. Current research shows that metformin may become a new strategy for the treatment of NHL.

Development of a cell-based diagnostic system for vitamin K-dependent coagulation factor deficiency 1 / 中华医学遗传学杂志

OBJECTIVE@#To develop a cell-based system for the diagnosis of vitamin K-dependent coagulation factor deficiency 1 (VKCFD1).@*METHODS@#In HEK293 cells stably expressing the reporter gene FIX-Gla-PC, the gamma-glutamyl carboxylase (GGCX) gene was knocked out by using CRISPR/Cas9 technology. Enzyme-linked immunosorbent assay (ELISA), DNA sequencing and Western blotting were used to identify the GGCX gene knockout cells. A quickchange point variant method was used to construct the GGCX variant. ELISA was used to assess the influence of GGCX variant on the activity of reporter gene.@*RESULTS@#Two monoclonal cell lines with no reporter activity by ELISA was identified. Edition and knockout of the GGCX gene was confirmed by DNA sequencing and Western blotting. The activity of the reporter gene was recovered by transfection of the wild-type GGCX gene. Thereby two monoclonal cells with GGCX knockout were obtained. By comparing the wild-type and pathogenic GGCX variants, the reporter activity was decreased in the pathogenic variants significantly.@*CONCLUSION@#A cell-based system for the detection of GGCX activity was successfully developed, which can be used for the diagnosis of VKCFD1 caused by GGCX variants.

An in-gel digestion method of chymotrypsin to improve sequence coverage of membrane protein by mass spectrometry / 生物工程学报

In recent years, mass spectrometry has been widely used to study membrane protein structure and function. However, the application of mass spectrometry to study integral membrane protein is limited because there are many hydrophobic amino acids in the trans-membrane domain of integral membrane protein to cause low sequence coverage detected by LC-MS/MS. Therefore, we used vitamin K epoxide reductase (VKORC1), a human integral membrane protein, as a model to optimize the digestion conditions of chymotrypsin, and developed an in-gel digestion method of chymotrypsin to improve sequence coverage of membrane protein by mass spectrometry. By exploring the effects of calcium concentration, pH value and buffer system on the percentage of sequence coverage, number of total detected and types of unique peptide, and the size of unique peptide, sequence coverage and peptide diversity could be considered under condition of Tris-HCl buffer with 5-10 mmol/L calcium ion concentration and pH value 8.0-8.5. This method could make the sequence coverage of membrane protein to reach more than 80%. It could be widely used in the study of membrane protein structure and function, identification of interaction site between membrane proteins, and identification of binding site between membrane protein and small molecular drug.

Pilot-scale purification of lipopeptide from marine-derived Bacillus marinus / 生物工程学报

This research was aimed at establishing the pilot-scale purification technology of lipopeptide from marine-derived Bacillus marinus. We studied lipopeptide surfactivity interferences on scale-up unit technologies including acid precipitation, methanol extraction, solvent precipitation, salting out, extraction, silica gel column chromatography and HZ806 macroporous absorption resin column chromatography. Then, the unit technologies were combined in a certain order, to remove the impurities gradually, and to gain purified lipopeptide finally, with high recovery rate throughout the whole process. The novel pilot-scale purification technology could effectively isolate and purify lipopeptide with 87.51% to 100% purity in hectograms from 1 ton of Bacillus marinus B-9987 fermentation broth with more than 81.73% recovery rate. The first practical hectogram production of highly purified lipopeptide derived from Bacillus marinus was achieved. With this new purification method, using complex media became possible in fermentation process to reduce the fermentation cost and scale-up the purification for lipopeptide production. For practicability and economy, foaming problem resulting from massive water evaporation was avoided in this technology.

Optimization of photoautotrophic lipid production of Chlorella ellipsoidea seeded with heterotrophic cells / 生物工程学报

Photoautotrophic cultivation with heterotrophic cells as seeds (heterotrophic cells/photoautotrophic cultivation) is an effective way for the development of microalgal biofuel, but its development potential from the point of process optimization has not been investigated in literatures. To evaluate this, the optimizations of medium and culture conditions for Chlorella ellipsoidea were studied. In the heterotrophic stage, the biomass concentration reached 11.04 g/L with the optimized medium in flask, which were 28.0% higher than that with the original medium, and the biomass concentration reached 73.89 g/L in 5-L fermenter. In the photoautotrophic stage, the culture medium and conditions were studied in a 2-L column photobioreactor. The maximum biomass concentration, lipid content and lipid productivity reached 1.62 g/L, 36.34% and 6.1 mg/(L·h) under the optimal photoautotrophic conditions. The lipids were mainly composed of C16-C18 fatty acids, which were raw material suitable for biodiesel. After optimization, heterotrophic cells/photoautotrophic cultivation can significantly improve the capacity of biofuel production by Chlorella ellipsoidea, this method is also expected to be an efficient way for the cultivation of other microalgae that can grow heterotrophically.

ANALYSIS OF PROTEASE KINDS AND ACTIVITIES IN SEVEN KINDS OF TISSUES AND ORGANS OF ANDRIAS DAVIDIANUS / 解剖学报

Objective Finding out the kinds and activities in protease of brain,heart,lung,kidney,eyes,skin and muscle of Andrias davidianus. Methods Using protease returned electrophoresis technique(G-PAGE). Results 1.Activity of proteases in brain was weak at pH 4.5,and showed no activity at pH 7.0 and pH 9.5;2.Proteases of heart and lung had activities at pH 4.5 and pH 7.0;3.Activity of kidney proteases was strong at pH 4.5 and stronger at pH 7.0,and kinds of proteases were more at pH 7.0 than at pH 4.5;4.Proteases in eyes had no activity at pH 4.5 and pH 9.5;5.Activity of proteases in muscle was very strong at pH 7.0 and pH 9.5,and kinds of proteases were more at pH 7.0 than at pH 9.5;6.Activity of skin proteases was similar to that of muscle,but the former was weaker than the later. Conclusions Among the seven kinds of tissues and organs of Andrias davidianus,kinds and activities of kidney and muscle proteases were stronger and more than others;and the eyes showed almost no protease activity.The proteases-activity optimal pH of brain was acidic;The proteases-activity optimal pH of heart,lung and kidney was acid of neutral;and the proteases-activity optimal pH of skin and muscle was neutral.