Research progress in changes of Na + concentration and Na +/K + value in breast milk of lactating women at different conditions / 中华围产医学杂志

Breastfeeding is a key factor influencing infants' short- and long-term health, thus making it important to monitor breast function. This article reviews the changes in Na + concentration and Na +/K + value in breast milk during secretory activation and at physiological and pathological conditions, aiming to provide a reference for early clinical assessment and intervention of physiological or pathological changes in the breast during lactation and to improve the outcome of breastfeeding.

Evaluation of the consistency and detection capability of seven domestic 2019-nCoV nucleic acid detection kits / 中华检验医学杂志

Objective:To compare the consistency and detection capability of seven 2019-nCoV nucleic acid detection kits, and provide reference for detection method selection of clinical laboratory and diagnosis of new coronavirus pneumonia.Methods:Two batches of pharyngeal swab samples were collected from tenpatients with confirmed infection of 2019-nCoV and 10 suspected patients with negative 2019-nCoV test results during January 29 to February 5, 2020 in Shenzhen Luohu People′s Hospital. Seven kinds of kits were labeled as ato g and used for nucleic acid detection respectively to evaluate the consistency of the test results of the clinical samples. A 2019-nCoV positive specimen was selected and diluted to 5-concentration gradient plates (Level-1 to 5) with RNase-free water. The positive detection rate and intra-batch repeatability of different brands of kits were compared.Results:The negative and positive coincidence rates of twenty clinical samples tested by six kinds of kits were 100%, and the positive and negative coincidence rate was 8/10 and 10/10 for the other kit, respectively. The results of intra-batch repeatability showed the CVs of viral loads tested by these seven kits were all less than 5%. In the concentration range of Level-1 to 3, the detection capability for open reading frame (ORF)1ab gene of Kit b,d and f was lower than Kit a,c,e and g, and the detection capability of kit e and g was the highest (14/15). The detection capability for N gene of Kit a (15/15) was higher than the other 5 kits. The comprehensive analysis of the detection capability for ORF1ab and N gene showedthat Kit d had the lowest detection capability (ORF1ab:40%,N:53%), and there was no significant difference in the detection capability of Kit a, b, c, e, and f.Conclusions:There was no significant difference in the accuracy and repeatability of the seven kits for positive samples with high viral loads, and the detection performance was good; but some kits had poor detection capability for weak positive samples. It is suggested that the weak positive samples should be rechecked by at least two manufacturers′ kits to ensure the accuracy of the results.

Study on the inhibitory effect of the black garlic extract on the growth of hela cells / 中国医师杂志

Objective To explore the effect of black garlic extract on HeLa cells and its possible molecular mechanisms.Methods Inhibitory rate of HeLa cells was detected with methyl thiazolyl tetrazolium(MTT).Flow cytometry annexin V-fluorescein isothiocyanate/propidium iodide (V-FITC/PI) was used to detect tumor cell apoptosis.Flow cytometry was used to measure cell-cycle changes.Immunohistochemistry method was used to detect expressions of tumor proteins bax and Bcl-2.Results Black garlic extract significantly inhibited the growth of HeLa cells.Black garlic extract significantly induced apoptosis of HeLa cells.The apoptosis rate was (53.26 ± 1.78)％ in the black garlic high-dose group,and (3.68 ±0.11)％ in the control group.Black garlic extract affected cell cycle,upregulated bax expression,and downregulated bcl-2 expression.Conclusions Black garlic extract significantly induced the apoptosis of HeLa cells.This effect might be caused through increasing G2/M cells or changing expressions of bax and bcl-2.

Analysis of the complete genome sequence of a Shenzhen coxsackievirus A2 strain SHZH13-01 / 中华微生物学和免疫学杂志

Objective To analyze the complete genome sequence of a Shenzhen coxsackievirus A2 strain CVA2-SHZH13-01 and its evolution.Methods RT-PCR was used to amplify the complete genome of CVA2-SHZH13-01 strain.The PCR products were purified and sequenced to analyze their genetic character-istics.Results The complete genome of CVA2-SHZH13-01 strain was 7400 bp in length, encoding 2191 amino acids.CVA2-SHZH13-01 strain was highly similar with the novel recombinant CVA2-HK (431306) strain isolated from Hong Kong sharing the nucleotide homology of 98.3%, 98.8%, 99.0%, 99.2%, 98.8%and 98.9%in 5′UTR, P1 ( VP1 to VP4) , P2, P3, 3′UTR regions and complete genome, respec-tively.CVA2-SHZH13-01 strain was highly identical to the international standard strain CVA2-Fleetwood showing the homology of 81.6% in nucleotide sequences in P1 region, but closely associated with EV71-SHZH03 and EV71-GD2009 strains (82.8%-88.7%) in P2 and P3 regions.The phylogenetic analysis in-dicated that CVA2-SHZH13-01 strain belonged to the CVA2-HK (431306) variant.Data from analysis of amino acid in P1 region showed that there were three amino acid mutations in CVA2-SHZH13-01 strain including aa5L→F, aa666S→G and aa671T→I as compared with CVA2-HK (431306) strain.Conclusion CVA2-SHZH13-01 strain belonged to CVA2-HK (431306) variant.

Engineering and metabolic characteristics of a Clostridium tyrobutyricum strain / 生物工程学报

Clostridium tyrobutyricum is suitable for simultaneous saccharification and fermentation of lignocellulosic. It can produce butyric acid, acetic acid as its main fermentation products from a wide variety of carbohydrates such as glucose, xylose, cellobiose and arabinose. In order to decrease acetic acid content and increase butyric acid content in C. tyrobutyricum, we replaced genes on the acetic acid fermentation pathway with genes on the butyric acid fermentation pathway. Three genes were selected. They were acetyl-CoA acetylrtansfers gene (thl) which is the key enzyme gene associated with acetic acid fermentation pathway from Clostridium acetobutylicum, erythromycin gene (em) from plasmid pIMP1 and phosphotransacetylase gene (pta) which is the key enzyme gene associated with butyric acid fermentation pathway from C. tyrobutyricum. We fused these genes with pUC19 to construct nonreplicative integrated plasmids pUC19-EPT. Then we transformed pUC19-EPT into C. tyrobutyricum through electroporation. The recombinant transformants grown on plates containing erythromycin were validated by PCR. A mutant whose pta gene was displaced by thl gene on the chromosome was selected. In the fermentation from glucose, the mutant's yield of butyric acid is 0.47, increased by 34% compared with wild type; and the yield of acetic acid is 0.05, decreased by 29% compared with wild type.

Hospital Infection in Clinical Laboratory:Problem and Countermeasure / 中华医院感染学杂志

OBJECTIVE To prevent the hospital infection event in the clinical laboratory.METHODS The problems of clinical laboratory in hospital infection were found out then and the conception of self-protection,amplify necessary rules and regulations,fine technique training,disinfection of the instrument and environment of laboratory even the test reports,and the management of hospital infection were enhanced.RESULTS By taking appropriate measures and countermeasures,we could control most hospital infection in clinical laboratory,and ensure the safety and health of the laboratory staff.CONCLUSIONS The hospital infection event of clinical laboratory can be prevented by amplification of necessary rules and regulations as well as enhancement of the training and management.