No abstract

Protective effect of Qishen Yiqi dropping pills on the myocardium of rats with chronic heart failure (CHF) was investigated. Sixty rats were divided into the sham operation (n=20), the model (n=20) and the Qishen Yiqi dropping pill treatment group (n=20) using the random table method. The treatment group received administration of Qishen Yiqi dropping pills. The model and the sham operation group were given the same amount of normal saline. Within 24 h after the last administration, the rats were sacrificed. The myocardia were used for reverse transcription-polymerase chain reaction, western blot analysis and histological examination. In the sham operation group, cardiomyocytes were stained evenly and arranged neatly and densely with clear structures. In the model group, the cell morphology was fuzzy, the myocytes were hypertrophied, the nuclear pyknosis was fragmented, the arrangement was disordered, the intercellular space was narrowed, and the cytoplasm was missing. The apoptosis rates of cardiomyocytes in the model and Qishen Yiqi dropping pill treatment group were significantly higher than that in the sham operation group (P<0.05). The myocardial infarction areas in the model group and the Qishen Yiqi dropping pill treatment group were larger than that in the sham operation group (P<0.05). The expression levels of transforming growth factor-β1, mothers against decapentaplegic homolog 2 (Smad2), Smad3, and caspase-3 messenger ribonucleic acids and proteins in the model group and the Qishen Yiqi dropping pill treatment group were higher than those in the sham operation group (P<0.05). Qishen Yiqi dropping pills have an obvious myocardial protective effect on CHF rats, which may enhance the degree of myocardial fibrosis by inhibiting the TGF-β1/Smads pathway and improve cardiomyocyte apoptosis by suppressing the caspase-3 signaling pathway, thus protecting the myocardium.

No abstract

BACKGROUND D‐psicose is a rare sugar and exists in extremely small quantities in nature. It has important physiological functions and is allowed to be used as an ingredient in foods and dietary supplements. The aim of this study is to develop the biotransformation, separation and purification methods for highly efficient mass production of d‐psicose. RESULTS First, the gene of d‐psicose 3‐epimerase (DPE) from Ruminococcus sp. was cloned and overexpressed in the food‐grade microorganism Bacillus pumilus, and the recombinant protein was soluble, bioactive, and secretory overexpressed at a high level. The substrate specificity and metal ion effects of DPE were investigated. The recombinant DPE was immobilized onto anion exchange resin matrix, and the enzymatic properties and rounds of reuses of the immobilized DPE were investigated. Then, d‐psicose was produced using the immobilized enzyme, separated by simulated moving bed chromatography (SMB), and finally purified by crystallization. The purity of the d‐psicose crystal reached 99.1%. CONCLUSION Food grade high purity d‐psicose can be efficiently produced and purified using the methods developed in this research, which can be easily scaled up for industrial‐scale mass production. © 2017 Society of Chemical Industry

BackgroundAcidithiobacillus caldus, a Gram-negative, chemolithotrophic sulfur-oxidizing bacterium, is widely applied in bioleaching. The absence of an ideal selection marker has become a major obstacle to achieve high efficiency of the gene transfer system for A. caldus. Plasmid pJRD215, widely used in Acidithiobacillus spp., has severe drawbacks in molecular manipulations and potential biosafety issues due to its mobility. Therefore, finding a new selection marker and constructing new plasmids have become an urgent and fundamental work for A. caldus.ResultsEffective inhibitory effect of chloramphenicol on the growth of A. caldus was elucidated for the first time. The P2-cat gene cassette, including a chloramphenicol acetyltransferase gene (cat) from plasmid pACBSR and a promoter (P2) upstream of the tetracycline resistance gene on pBR322, was designed, chloramphenicol acetyltransferase was expressed in A. caldus, and the enzyme activity was assessed. A new vector pSDU1 carrying the replication and mobilization regions derived from pJRD215, the P2-cat gene cassette and a multiple cloning site from pUC19 was successfully constructed. Compared with pJRD215, pSDU1 had a 27-fold increase in electrotransformation efficiency (30.43±0.88×104 CFU/μg DNA for pSDU1 and 1.09±0.11×104 CFU/μg DNA for pJRD215), better carrying capacity and could offer more convenience for the restriction enzyme digestion. In addition, the generated plasmid pSDU1Δmob, a novel non-mobilizable derivative of pSDU1 lacking some DNA sequences involved in the mobilization process, had increased copy number in A. caldus and lost its mobility for biosafety considerations. Both pSDU1 and pSDU1Δmob exhibited stable maintenance in A. caldus within 50 passages. However, further deletion of orfEF region involved in regulating repAC operon resulted in a negative effect on transformation efficiency, copy number and stability of plasmid pSDU1ΔmobΔorfEF in A. caldus.ConclusionChloramphenicol was proved to be an ideal selection marker for A. caldus. Novel plasmids carrying cat gene were constructed. The utilization of these vectors will undoubtedly facilitate efficient genetic manipulations and accelerate the research progress in A. caldus.