Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Medical supply is a key resource for responding to public health emergencies and maintaining people's lives and health. As the medical equipment management department, the medical devices department is mainly responsible for the procurement, supply, technical support, management and coordination of medical equipment and medical consumables, playing an important role in epidemic prevention and control. Through the analysis of the expansion cases of designated hospitals, the experience of emergency management of medical equipment has been accumulated, which has strong practicability and replicability.
Humans ; Public Health ; Emergencies ; Hospitals ; Epidemics

Objective:To explore the effects of ultraviolet B (UVB) on the premature senescence of human immortalized keratinocytes HaCaT cells and the possible underlying molecular mechanism.Methods:HaCaT cells were exposed with UVB of different doses (20, 50, 80 and 100 mJ/cm 2). At 72 h after exposure, cellular morphology was observed by Giemsa staining, cell proliferation was detected by clone formation assay, and the proportion of premature senescence cells was detected by β-galactosidase staining. The number change of lysosomes was detected by Lyso-Tracker Red fluorescence probe at 24, 48 and 72 h after exposure. Cell migration was measured by scratch test at 24 h and 48 h after exposure. The protein expressions of p53 and p16 related to premature senescence were detected by Western blot assay at 72 h after exposure. Results:After UVB exposure, HaCaT cells showed a premature senescence phenotype. At 72 h after exposure, the cell volume increased ( F=115.18, P<0.05), the cell proliferation ability decreased ( F=410.32, P<0.05), the activity of β-galactosidase increased ( F=16.31, P<0.05), and the expressions of P53 and P16 increased. In addition, the number of lysosomes increased at 24, 48, and 72 h after exposure ( F=17.65, 38.36, 13.66, P<0.05), and cell migration capacity was inhibited at 24 and 48 h after exposure ( F=8.21, 11.48, P<0.05). Conclusions:UVB exposure can induce premature senescence of HaCaT cells by increasing the expression of p53 and p16 proteins.

Objective To explore the influences of the final concentration and adding time of Cytochalasin-B (Cyt-B) on radiation-induced nucleoplasmic bridges (NPB) in cytokinesis-block assay.Methods Hunan peripheral blood samples were divided into 5 final concentration groups (group 2,4,6,8,10 μg/ml) according to different final concentrations of Cyt-B.Moreover,blood samples were divided into 4 adding time groups (group 0,28,40,44 h) according to different adding times of Cyt-B.Blood samples were irradiated with 0 (sham irradiation) and 2 Gy 60Co-rays in vitro,at a dose rate of 1 Gy/min.A cytokinesis-block assay was carried out to prepare NPB samples.The percentages of mononucleated,binucleated and multinucleated cells,as well as the frequencies of NPB and micronucleus (MN) in binucleated cells were analyzed using an optical microscope.Results Nuclear division index (NDI) and the percentages of binucleated cells increased with increased concentration of Cyt-B,and decreased with delayed adding time of Cyt-B (except group 0 h) in both final concentration groups and adding time groups.After exposed to 2 Gy,NPB frequencies were no significant difference (except group 0 h).MN frequencies had the trend of decreased with the increased concentration of Cyt-B,but no significant difference with adding time of Cyt-B.Conclusions In cytokinesis-block assay,different final concentration and adding time of Cyt-B may induce to the variation of NPB frequencies,but there was no significant difference.Appropriate increased final concentration or ahead adding time of Cyt-B can increase the percentage of binucleated cells that help to improve the efficiency of analysis.

OBJECTIVETo evaluate the value of three preoperative imaging methods in the anterolateral thigh flap (ALT) transplantation.

METHODSAccording to preoperative imaging, patients who underwent the ALT flap transplantation were divided into three groups: computed tomography angiography (CTA) group, digital subtract angiography ( DSA) group and magnetic resonance angiography (MRA) group. There were fifteen cases in each group. We compared the imaging quality of the ALT artery among these groups and recorded the parameters of lateral femoral circumflex artery, descending branches and perforators including type, course and size. The results from images were compared with intraoperative findings. The success rate and complications were also recorded.

RESULTSThe preoperative imaging accuracy of the types of the lateral femoral circumflex artery and descending branch was more than 92.3%, with no significant different between any two of three groups (P > 0.05). The difference in diameters of descending branches and perforators from preoperative measurement and from intraoperative measurement was also not significant between any two of the three groups; the success rate and complications were not also obviously different (P > 0.05 , P > 0.05, respectively).

CONCLUSIONSPreoperative mapping using CTA, DSA and MRA is a feasible and reliable method for the flap design in ALT transplantation. As a preoperative evaluation means, CTA and MRA may replace DSA in the ALT transplantation.

Angiography, Digital Subtraction ; methods ; Feasibility Studies ; Femoral Artery ; anatomy & histology ; diagnostic imaging ; Humans ; Magnetic Resonance Angiography ; Preoperative Care ; Surgical Flaps ; transplantation ; Thigh ; Tomography, X-Ray Computed

Noroviruses (NoVs) are one of the most important foodborne viral pathogens worldwide. Shellfish are the most common carriers of NoVs as they can concentrate and accumulate large amounts of the virus through filter feeding from seawater. Shellfish may selectively accumulate NoVs with different genotypes, and this bioaccumulation may depend on the season and location. Our previous studies found various histo-blood group antigens (HBGAs) in shellfish tissues. While HBGAs might be the main reason that NoVs are accumulated in shellfish, the detailed mechanism behind NoV concentration and bioaccumulation in shellfish is not clear. Here we review current research into NoV bioaccumulation, tissue distribution, seasonal variation, and binding mechanism in shellfish. This paper may provide insight into controlling NoV transmission and decreasing the risks associated with shellfish consumption.
Animals ; Caliciviridae Infections ; transmission ; virology ; Food Contamination ; analysis ; Foodborne Diseases ; virology ; Humans ; Norovirus ; classification ; genetics ; isolation & purification ; physiology ; Shellfish ; virology

Objective To establish the analysis criteria of nucleoplasmic bridges (NPB) and a dose-response curve of NPB frequencies in human peripheral blood lymphocytes irradiated by 60Co γ-rays.Methods Human peripheral blood samples were collected from three healthy males,and were irradiated with 0,1,2,3,4,5 and 6 Gy of 60Co γ-rays.A cytokinesis-block micronucleus assay was carried out to analyze NPBs and micronuclei (MN) in binucleated cells.Results NPBs in binucleated cells at each dose level of γ-ray was conformed to the Poisson distribution.The dose-response curve of the γ-ray-induced NPB frequencies in human peripheral lymphocytes followed the linear-quadratic model y =(1.39 × 10-3)x2 + (4.94 × 10-3)x (R2 =0.981,P ＜ 0.05).Conclusions The dose-response curve of NPB frequencies in human peripheral blood lymphocytes induced by 0-6 Gy 60Co γ-rays was established.

Objective For developing safe and effective anti-radiation new drugs,the effects of different lipoic acid amino acid salts on radiosensitivity were investigated.Methods The free radical scavenging ability of the above salts was evaluated in Fenton system.CCK-8 assay and flow cytometry assay were performed to evaluate the survival rate of L02 and apoptosis of AHH-1 after γ-ray irradiation,respectively.Results The lipoic acid arginine salt had the best ability of scavenging free radicals in Fenton system with an IC50 of 8.40 μ moL/ml.The survival assay showed that lipoic acid amino acid salts had better stability and equal ability in radioprotection (P ＞ 0.05) compared with lipoic acid.The apoptosis assay indicated that all lipoic acid amino acid salts could inhibit radiation-induced apoptosis,where lipoic acid arginine salt was more effective (t =-6.67,P ＜ 0.01).Conclusions Lipoic acid arginine salt has good radioprotection effect on L02 and AHH-1 cells by scavenging free radicals.

Objective To study the Mediating effect of insecurity between childhood abuse and emotional distress of medical students,and to provide basis to intervene their mental disorder.Methods Through stratified sampling,262 medical students in Jiangsu were investigated by the Personal Report of Childhood Abuse( PRCA),Self-Rating Feeling of Insecurity Scale( SRFIS),Beck Depression Inventory( BDI ),Self-rating Anxiety Scale(SAS)and Suicide Ideation Scale(SIS).A path analysis was applied by Analysis of Moment Structures(AMOS) version 7.0.Results The path analysis showed that childhood abuse was directly related to insecurity of medical students ( β =0.538,P ＜0.01 ),and was directly related to emotional distress ( β =0.435,P ＜ 0.01 ).Insecurity were directly related to emotional distress of medical students ( β =0.342,P ＜ 0.05 ).Insecurity mediated partly the relationship between childhood abuse and emotional distress of medical students.The model fit indexes were X2/df =1.365 ＜ 3.000,P =O.082 ＞ 0.05,RMSEA =0.037 ＜ 0.050,GFI =0.971,AGFI =0.940,NFI =0.943,RFI =0.902,IFI =0.984,TLI =0.972,CFI =0.984.Conclusion Insecurity as mediated variable mediates the relationship between childhood abuse and emotional distress of medical students.