The 4-hydroxyphenylacetate 3-hydroxylase (4HPA3H), originated from Escherichia coli, converts p-coumaric acid to caffeic acid. In order to improve the efficiency of caffeic acid biosynthesis, we engineered E. coli for overexpression of 4HPA3H. The high-density fermentation of the engineered E. coli was conducted in a 5 L bioreactor. Subsequently, the conditions for whole-cell biocatalysis were optimized. The dry cell weight of the 4HPA3H-expressed strain reached 34.80 g/L. After incubated in the bioreactor for 6 h, 18.74 g/L (0.85 g/(L·OD₆₀₀)) of caffeic acid was obtained, with a conversion rate of 78.81% achieved. To the best of our knowledge, the titer of caffeic acid is the highest reported to date. The high-density fermentation of E. coli for overexpression of 4HPA3H and the efficient biosynthesis of caffeic acid may facilitate future large-scale production of caffeic acid.
Caffeic Acids ; Escherichia coli/metabolism* ; Fermentation ; Metabolic Engineering ; Mixed Function Oxygenases/metabolism* ; Phenylacetates

Traumatic rib fractures are the most common injury in thoracic trauma. Previously，the patients with traumatic rib fractures were mostly treated non-surgically，of which 50%，especially those combined with flail chest presented chronic pain or chest wall deformities and over 30% had long-term disabilities，being unable to retain a full-time job. In the past two decades，thanks to the development of internal fixation material technology，the surgical treatment of rib fractures has achieved good outcomes. However，there are still some problems in clinical treatment，including inconsistency in surgical treatment and quality control in medical services. The current consensuses on the management of regional traumatic rib fractures published at home and abroad mainly focus on the guidance of the overall treatment decisions and plans，and relevant clinical guidelines abroad lacks progress in surgical treatment of rib fractures in recent years. Therefore，the Chinese Society of Traumatology affiliated to Chinese Medical Association and Chinese College of Trauma Surgeons affiliated to Chinese Medical Doctor Association，in conjunction with national multidisciplinary experts，formulate the Chinese Consensus for Surgical Treatment of Traumatic Rib Fractures（2021）following the principle of evidence-based medicine，scientific nature and practicality. This expert consensus puts forward some clear，applicable，and graded recommendations from aspects of preoperative imaging evaluation，surgical indications，timing of surgery，surgical methods，rib fracture sites for surgical fixation，internal fixation methods and material selections，treatment of combined injuries in rib fractures，in order to provide references for surgical treatment of traumatic rib fractures.

BACKGROUND: Myocardial ischemia/reperfusion injury is one of the most common complications in ischemic cardiomyopathy and open heart surgery. The development of bone marrow mesenchymal stem cells provides a new method for clinical prevention and treatment of myocardial ischemia/reperfusion injury. OBJECTIVE: To review the therapeutic effect and potential mechanisms of bone marrow mesenchymal stem cells in the treatment of myocardial ischemia/reperfusion injury, in order to provide a theoretical basis for the clinical application of bone marrow mesenchymal stem cells. METHODS: Chinese Journal Full-text Database (CNKI) , WanFang, and PubMed were retrieved for articles related to the use of bone marrow mesenchymal stem cells for myocardial ischemia-reperfusion injury published from January 2000 to October 2018. The search terms were "bone marrow mesenchymal stem cells; myocardial ischaemia/reperfusion; research process" in Chinese and "bone marrow mesenchymal stem cells; myocardial ischaemia/reperfusion; cell therapy; clinical trial studies" in English. Old and repetitive viewpoints were excluded, the searched literatures were sorted out, and finally 56 articles were included for further analysis and discussion. RESULTS AND CONCLUSION: (1) In this paper, we summarize paracrine factors, exosomes miRNA and their effects in the treatment of myocardial ischemia/reperfusion injury with bone marrow mesenchymal stem cells, such as anti-inflammation, anti-apoptosis, anti-fibrosis, repair of myocardium and neovascularization. (2) We also summarize the possible molecular mechanisms of bone marrow mesenchymal stem cells involved in the treatment of myocardial ischemia/reperfusion injury, such as the role of mitochondrial fusion protein 2, regulation of myocardial autophagy, and regulation of AMPK/mTOR signaling pathway. Overall, we attempt to provide a theoretical basis for the clinical application of bone marrow mesenchymal stem cells in the treatment of myocardial ischemia/reperfusion injury.

OBJECTIVE： To investigate the effects of adiponectin （APN） on the expression of myocardial AMPK in myocardial insulin resistance （IR） model dogs during cardiopulmonary bypass （CPB）. METHODS： Totally 24 dogs were randomly divided into control group， model group， APN group （36 μg/kg）， AMPK inhibition group （APN 36 μg/kg+AMPK inhibitor compound C 0.5 mg/kg）， with 6 dogs in each group. All dogs underwent CPB； except for control group without medicine， CPB myocardial IR model were established in other groups， and perfused with St.Thomas cardiac cardioplegia lipid no medicine or containing relevant drugs after main artery block. Coronary sinus blood and carotid artery blood samples were collected before bypass and after 15， 90 min reperfusion following 60 min myocardial ischemia. Left ventricular apical tissue was taken， and the uptake rate of myocardial glucose and insulin resistance index （IRI） were determined and calculated； the changes of myocardial injury indexes （cTnT concentration） and cardiac function indexes （LVSP， +dp/dtmax） were monitored. The level of p-AMPK was detected. RESULTS： There was no statistical significance in above indexes of dogs before bypass （P＞0.05）. Compared with control group， the rate of myocardial glucose uptake， the levels of LVSP， +dp/dtmax and p-AMPK in model group were decreased significantly after 15， 90 min reperfusion （P＜0.05）， and the concentrations of IRI and cTnT were increased significantly （P＜0.05）. Compared with model group， the rate of myocardial glucose uptake， LVSP， +dp/dtmax and p-AMPK were increased significantly in APN group and AMPK inhibitor group （P＜0.05）， while the concentrations of IRI and cTnT were decreased significantly （P＜0.05）； moreover， the effect of APN group was better than that of AMPK inhibitor group （P＜0.05）. CONCLUSIONS： APN can promote myocardial glucose uptake and metabolism， and contribute the recovery of cardiac function， the mechanism of which may be associated with increasing the activity of AMPK.

Objective To investigate the safety and longterm outcomes of prophylactic autologous pericardium tricuspid valve annuloplasty(TVA)in patients with rheumatic heart disease(RHD). Methods A total of 832 patients with RHD were enrolled in this study ,including 146 patients with mild FTR but without TVA(observation group);434 patients with mild FTR underwent TVA(control group A)and 434 patients with moderate or severe FTR underwent TVA(control group B). Propensity score and survival analysis were used to evaluate perioperative safety ,FTR progression ,CHF and MACCE incidence after prophylactic TVA. Results A total of 192 patients were successfully matched. There was no significant difference in the perioperative complications between the observation group and the control groups(P>0.05). The progression rate of FTR in the observation group was significantly lower than that in the control groups (P = 0.005 & 0.032 ). There was no significant difference in the incidence of CHF and MACCE events between the observation group and the control groups (P > 0.05). Conclusions The treatment strategy of prophylactic autologous pericardium TVA at the time of left heart valve surgery for patients with RHD doesn′t increase operation costs ,perioperative complications and mortality ,but effectively prevent postoperative FTR recurrence or progression.

Objective To evaluate the efficacy of flupentixol and melitracen in optimizing conven-tional treatment for postherpetic neuralgia. Methods Seventy patients of both sexes with thoracolumbar postherpetic neuralgia, were divided into 2 groups ( n＝35 each) according to the registration order: pa-tients with odd number were included in control group ( group C) and patients with even number were in-cluded in flupentixol-melitracen group (group D). Patients in group C received conventional treatment: an-ti-epileptic drugs, analgesia with opioids, neurotrophy, paravertebral nerve block and physical therapy. Flupentixol-melitracen 10. 5 mg was taken orally based on the conventional treatment in group D. The time for treatment was recorded. The severity of pain was assessed by using the numeric rating scale, and anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale before treatment and on 3rd and 7th days after treatment. The development of flupenthixol and melitracen-related adverse reactions was recorded during treatment in group D. Results Compared with group C, the numeric rating scale and Hos-pital Anxiety and Depression Scale scores were significantly decreased on 3rd and 7th days after treatment, and the time for treatment was shortened in group D (P＜0. 05). No flupenthixol-and melitracen-related ad-verse reactions were found in group D. Conclusion Flupentixol-melitracen can optimize the conventional therapeutic effect for postherpetic neuralgia.

OBJECTIVE:To explore the effects of acadesine on myocardial energy metabolism of model dogs with myocardial ischemia-reperfusion injury (MIRI) after cardiopulmonary bypass (CPB). METHODS:Dogs were randomly divided into control group,model group,acadesine low-dose,high-dose groups(0.8,3.2 mg/kg),6 in each group. All dogs received CPB. Except for control group,dogs in other groups were reduced for MIRI model,and perfused St.Thomas cardiac cardioplegia lipid containing rel-evant drugs 60 min after main artery block. The uptake rates of myocardial glucose and free fatty acid(FFA),creatine kinase isoen-zyme(CK-MB)concent in venous sinus plasma and adenosine triphosphate(ATP)content in mitochondria were detected and calcu-lated before bypass and after 15,60,90 min of reperfusion. Left ventricular systolic pressure(LVSP)and left ventricular end dia-stolic pressure(LVEDP)were analyzed,and mRNA expression of adenylate-activated protein kinase(AMPK)and protein expres-sion of phosphorylated AMPK(p-AMPK)in myocardial tissue were detected. RESULTS:Before bypass,all indexes in each group had no statistic significances(P>0.05). After bypass,compared with control group,uptake rates of myocardial glucose and FAA, ATP content,mRNA expression of AMPK and protein expression of p-AMPK and LVSP in 3 time points in model group and each administration group were obviously decreased(P<0.05);LVEDP and CK-MB concent in plasma were obviously increased(P<0.05). Compared with model group,uptake rates of myocardial glucose and FAA,ATP content,mRNA expression of AMPK and protein expression of p-AMPK and LVSP in 3 time points in each administration group were obviously increased (P<0.05);LVEDP and CK-MB concent in plasma were obviously decreased (P<0.05);and high-dose group showed more obvious change than that of low-dose group (P<0.05). CONCLUSIONS:Acadesine can promote the AMPK phosphorylation,contribute to the myocardial glucose and FFA uptake to promote the increase of ATP in myocardial mitochondria and relieve MIRI after CPB.

Objective To develop a kind of rapid decompression equipment replacing the toughened glass simulating the state of aircraft cabin glass bursting on the fly.Methods The metallic membrane was used to isolate both chambers with different air pressures.The areas of decompression membrane and path were determined by calculating on the basis of aircraft decompression altitude,cabin pressure differential and decompression time.The structural strength was determined according to enduring force of the metallic membrane.The membrane was ejected by high pressure air using the ejection launch technology of aircraft missile.The result of simulating aircraft cabin glass bursting on the fly was achieved.Results The rapid decompression equipment ejected by air pressure in low-pressure chamber could achieve the state of simulating aircraft cabin glass bursting on the fly,and the best decompression time was 0.16 s.Conclusion The rapid decompression equipment ejected by air pressure accomplishes the decompression preparative in short time with easy operation,and can satisfy the desired requirements for the performance and precision.

Objective To evaluate the role of autophagy in the development of inflammatory pain in the rats.Methods Twenty-four healthy adult male Sprague-Dawley rats,weighing 180-240 g,were randomly divided into 4 groups (n=6 each) by using a random number table:control group (group C),inflammatory pain group (group IP),dimethyl sulfoxide (DMSO) group (group D),and rapamycin (autophagy inducer) group (group R).Inflammatory pain was produced by injecting 50 μl bee venom into the plantar surface of the left hindpaw.In group C,0.9％ normal saline was injected into the plantar surface of the left hindpaw.In group D,2％ DMSO was injected through a gastric tube into the stomach 1 ml per day for 3 consecutive days,and the model was established at 1 h after injection on 3rd day.In group R,rapamycin l0 mg/kg (in 2％ DMSO) was injected through a gastric tube into stomach 1 ml per day for 3 consecutive days,and the model was established at 1 h after injection on 3rd day.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 2 h after the model was established.After measurement of the pain threshold,the dorsal horn of the spinal cord was removed for determination of the expression of microtubule-associated protein 1 light chain 3 Ⅱ (LC3 Ⅱ),Beclin-1 and p62 by Western blot.Results Compared with group C,the MWT was significantly decreased,the TWL was significantly shortened in IP and D groups,and the expression of LC3 Ⅱ,Beclin-1 and p62 in the dorsal horn of the spinal cord was significantly up-regulated in IP,D and R groups (P＜0.05 or 0.01).Compared with group IP,the MWT was significantly increased,the TWL was significantly prolonged,the expression of LC3 Ⅱ and Beclin-1 in the dorsal horn of the spinal cord was significantly up-regulated,and the expression of p62 was significantly down-regulated in group R (P＜0.05),and no significant change was found in the parameters mentioned above in group D (P＞0.05).Conclusion Autophagy disorders are involved in the development of inflammatory pain in the rats.

BACKGROUND:Some studies have shown that the double-bundle posterior cruciate ligament reconstruction is not superior to the single-bundle posterior cruciate ligament reconstruction, and stil has some deficiencies difficult to overcome. Which is better, double-bundle reconstruction or single-bundle reconstruction? There is no uniform conclusion. OBJECTIVE:To perform a prospective cohort study on the clinical efficacy and safety of autologous single- and double-bundle posterior cruciate ligament reconstruction. METHODS:Totaly 81 patients with posterior cruciate ligament injury were randomly divided into single-bundle reconstruction group (n=41) and double-bundle reconstruction group (n=40). The knee stability, Lysholm score, Tegner score, hospital stay, operation time, fever days and number of puncture cases were compared between the two groups before and 24 months after reconstruction. RESULTS AND CONCLUSION:Compared with the single-bundle reconstruction group, the knee stability was significantly worse in the double-bundle reconstruction group (F=4.362,P=0.000); the operation time, hospital stay and number of puncture cases were also higher in the double-bundle reconstruction group (P < 0.05). At 24 months after reconstruction, the Lysholm and Tegner scores were both increased significantly in the two groups (P < 0.05), but there was no difference between the two groups (P > 0.05). These findings indicate that both single- and double-bundle reconstruction under arthroscopy is safe and effective treatment for posterior cruciate ligament injury, but the double-bundle reconstruction is not recommended as the preferred surgical procedure because of longer time and larger trauma.