ABSTRACT
Objective To compare the regulation effects of different activated and inhibitory riboswitches , and to facilitate the precise regulation of gene circuits .Methods A green fluorescent protein amcyan expression vector regulated by different riboswitches (addA, M6, TPP and btuB) was constructed, and the expression level of amcyan under different ligand concentrations was analyzed by RT-qPCR and relative fluorescence intensity , and then compared with the expression level of a vector without any riboswitch .The dynamic control performance was analyzed .Results Under the control of addA and M6 activated riboswitches , the expression of green fluorescent protein increased with ligand concentrations , and addA riboswitch had more dynamic regulatory effect than M 6 riboswitch.However, under the control of TPP and btuB inhibitory riboswitches , the expression of green fluorescence decreased with the increase in ligand concentrations , and the dynamic regulation of btuB riboswitch was slightly greater than that of TPP riboswitch .Conclusion The regulation efficacy of different riboswitches which have the same mechanism varies .Activated riboswitch addA and inhibitory riboswitch btuB with dynamic regulation and control advantages are more suitable for precise metabolism regulation and target gene expression in Escherichia coli.
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Objective To develop chitosan composite keratinocyte growth factor-2 mutant(KGF-2M)temperature-sen-sitive dressing and evaluate its physicochemical properties and dynamic release rule were used.Methods Chitosan, chi-tosan quaternary ammonium salt,β-glycerophosphate and other adjuvant materials to configure different formulations which were compounded with KGF-2M in order to develop temperature-sensitive dressing.Gelling time, temperature,the release rate of KGF-2M and other indicators were measured to analyze the physical and chemical properties of the temperature -sen-sitive dressing.Results Chitosan-KGF-2M composite dressing with temperature-sensitive properties was obtained by opti-mizing the formulation components of chitosan and related adjuvant materials.When the liquid dressing was above 35℃,it could be converted from liquid to solid gelatin within 10 minutes.The compound KGF-2M released from the gel was more than 98%at 4 h,and its bioactivity remained stable.Conclusion The thermo-sensitive gel has the characteristics of good conformability,moisturizing(moisture),isolation,wound healing,and a controlled release effect,which has great potential in wartime for wound repair.
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Aim To explore the effects of interleukin-1 receptor antagonist (IL-1Ra) on intestinal ischemia-reperfusion (I/R) induced injury in rats. Methods Thirty-five male SD rats were randomly divided into sham operation group (S), model group (I/R), dif-ferent dosage drug groups(C1,C2,C3). Rat intesti-nal I/R model was established via clamping the superi-or mesenteric artery (SMA). After 1 h of ischemia, the arterial clamps were released for 1 h of reperfusion. 10,20,50 mg·kg-1of IL-Ra was injected via caudal vein 15min before reperfusion. Results After 2 h of I/R,compared with S group,I/R group rats exhibited severe damage on the intestinal mucosa, increase in MDA content, decrease in SOD activity, and signifi-cant release of TNF-α, IL-1β, IL-6. The results showed that, following the injection of IL-1Ra after clipping superior mesenteric artery, damage of the in-testinal mucosa was obviously relieved in different dos-age drug groups. Furthermore, there was different de-gree of relief on oxidative stress and inflammatory re-sponses. Conclusion IL-1Ra showed obvious protec-tive effect on intestinal I/R induced injury by relieving oxidative stress and inflammatory response,and it may potentially be used in the clinical treatment of intestinal I/R injury.
ABSTRACT
This study was aimed to set up and evaluate a quantitative method for detecting lumbrokinase level in plasma. The lumbrokinase was used to immunize rabbit and BALB/c mouse for preparation of rabbit or mouse-derived polyclonal antibodies, and then the standard curves were drawn up by detecting the lumbrokinase diluted in PBS using the double antibody sandwich ELISA. This method further was analyzed for its specificity, precision and recovery rate. This established double antibody sandwich ELISA was used to assay the lumbrokinase in human plasma, and the assayed results were assessed. The results showed that a double antibody sandwich ELISA for the detection of lumbrokinase has been established. And the standard curve fitting R value > 0.99, the precision assessment showed that the measured values of coefficient of variation (CV) in 3 batches were all < 15%; recovery assessment in 3 batches showed that all the measured recovery rates were > 80%; the quantitative low limit was assessed as 5 ng/ml (precision CV < 15%, recovery rate > 85%). It is concluded that this method is consistent with the criteria stipulated by the Pharmacopeia, which provides a reliable measurement method for quantitative detection of plasma lumbrokinase in clinical trials.