BACKGROUND:Due to the sudden release and the rapid removal by proteases,platelet-rich plasma hydrogel leads to shorter residence times of growth factors at the wound site.In recent years,researchers have focused on the use of hydrogels to encapsulate platelet-rich plasma in order to improve the deficiency of platelet-rich plasma hydrogels. OBJECTIVE:To prepare self-assembled polypeptide-platelet-rich plasma hydrogel and to explore its effects on the release of bioactive factors of platelet-rich plasma. METHODS:The self-assembled polypeptide was synthesized by the solid-phase synthesis method,and the solution was prepared by D-PBS.Hydrogels were prepared by mixing different volumes of polypeptide solutions with platelet-rich plasma and calcium chloride/thrombin solutions,so that the final mass fraction of polypeptides in the system was 0.1%,0.3%,and 0.5%,respectively.The hydrogel state was observed,and the release of growth factors in platelet-rich plasma was detected in vitro.The polypeptide self-assembly was stimulated by mixing 1%polypeptide solution with 1%human serum albumin solution,so that the final mass fraction of the polypeptide was 0.1%,0.3%,and 0.5%,respectively.The flow state of the liquid was observed,and the rheological mechanical properties of the self-assembled polypeptide were tested.The microstructure of polypeptide(mass fraction of 0.1%and 0.001%)-human serum albumin solution was observed by scanning electron microscope and transmission electron microscope. RESULTS AND CONCLUSION:(1)Hydrogels could be formed between different volumes of polypeptide solution and platelet-rich plasma.Compared with platelet-rich plasma hydrogels,0.1%and 0.3%polypeptide-platelet-rich plasma hydrogels could alleviate the sudden release of epidermal growth factor and vascular endothelial growth factor,and extend the release time to 48 hours.(2)After the addition of human serum albumin,the 0.1%polypeptide group still exhibited a flowing liquid,the 0.3%polypeptide group was semi-liquid,and the 0.5%polypeptide group stimulated self-assembly to form hydrogel.It was determined that human serum albumin in platelet-rich plasma could stimulate the self-assembly of polypeptides.With the increase of the mass fraction of the polypeptide,the higher the storage modulus of the self-assembled polypeptide,the easier it was to form glue.(3)Transmission electron microscopy exhibited that the polypeptide nanofibers were short and disordered before the addition of human serum albumin.After the addition of human serum albumin,the polypeptide nanofibers became significantly longer and cross-linked into bundles,forming a dense fiber network structure.Under a scanning electron microscope,the polypeptides displayed a disordered lamellar structure before adding human serum albumin.After the addition of human serum albumin,the polypeptides self-assembled into cross-linked and densely arranged porous structures.(4)In conclusion,the novel polypeptide can self-assemble triggered by platelet-rich plasma and the self-assembly effect can be accurately adjusted according to the ratio of human serum albumin to polypeptide.This polypeptide has a sustained release effect on the growth factors of platelet-rich plasma,which can be used as a new biomaterial for tissue repair.

Objective To evaluate the applicability of the comprehensive index method for assessing occupational health risks on chemical hazards in key work sites of a metal product enterprise. Methods A metal product enterprise in Beijing City was chosen as the research subject using the convenience sampling method. Occupational health investigations and chemical hazard monitoring were conducted at four work sites: grinding machine operation, welding, cutting, and painting. The comprehensive index method was used to determine the risk levels of chemical hazards. Results The grinding dust in the grinding machine operation work site was assessed as moderate risk. The nitrogen oxides and ozone in the welding (southeast) work sites were assessed as moderate risk. The nitrogen oxides ozone and welding fumes in the welding (northwest) and cutting work site were assessed as moderate risk. Benzene in the painting work site was assessed as moderate risk. All chemical hazards in other work sites were determined to pose low risks. Co-exposures to nitrogen oxides and ozone in the two welding work sites and cutting work site were classified as moderate risk. Co-exposure to ethylbenzene, xylene, methanol, ethyl acetate, and butyl acetate in the painting work site also posed moderate risk, while the co-exposure to toluene and methanol in the painting work site was assessed as low risk. Conclusion The comprehensive index method could be used for the occupational health risk assessment in the metal product enterprise. The enterprise should strengthen hazard control measures for exposure to grinding dust, welding fumes, nitrogen oxides, ozone, and benzene, and closely monitor the health risks associated with co-exposures of chemical hazards.

Objective To investigate the impact of iron overload on apoptosis in primary mouse liver cells via a synchronous separation technology.Methods Hepatocyte(HC),liver sinusoidal endothelial cell(LSEC),and Kupffer cell(KC)were isolated and purified with collagenase,percoll density gradient centrifugation,and CD146 magnetic beads.Cell types were identified using flow cytometry and immunofluorescence staining.Cells of different types were cultured in vitro,and an iron overload model was established by treating the mice with 0,25,50 and 100 μmol/L ferric ammonium citrate(FAC)for 24 h.The iron content was quantified using Prussian blue staining,while cell viability and mitochondrial membrane potential were assessed by flow cytometry.Results The synchronous separation technology of primary liver cells exhibited stable efficiency.The yield of HC was(4.0±0.5)×107 cells per mouse,exhibiting an effective survival rate of(76.33±0.67)％.The yield of LSEC was(5.0±1.0)×106 cells per mouse,with a survival rate of(93.63±0.25)％and a purity level of(93.40±0.46)％.The yield of KC was(1.5±0.5)×106 cells per mouse while a high survival rate of(98.33±0.12)％and a purity level of(88.30±2.02)％were maintained.The obtained cells were large in number,with good vitality and high purity,which could meet the requirements of subsequent experiments.Treatment with FAC significantly elevated iron contents in different types of cells when compared with the control group.Upon stimulation of FAC,the survival rate of HC decreased from(73.97±5.54)％to(54.10±1.68)％,the mean fluorescence intensity of JC-1 aggregates decreased from 326.33±30.37 to 155.00±6.56,JC-1 monomer increased from 1700.00±1 44.04 to 3713.33±81.82.The survival rate of LSEC decreased from(90.60±1.74)％to(78.03±2.15)％,the mean fluorescence intensity of JC-1 aggregates decreased from 502.33±5.51 to 372.33±4.04,and JC-1 monomer increased from 750.00±67.51 to 1340.00±36.39.The survival rate of KC decreased from(94.23±1.44)％to(88.37±1.56)％,the mean fluorescence intensity of JC-1 aggregates decreased from 652.67±25.66 to 478.00±12.49,and JC-1 monomer increased from 1984.33±80.65 to 3062.33±245.20.Conclusion A robust and reliable simultaneous isolation technique of primary mouse HC,LSEC,and KC has been established.Moreover,our finding demonstrates that iron overload significantly enhances apoptosis levels in HC,LSEC and KC.

Objective:To explore the medication rules of Professor Wang Pei in the treatment of colon cancer.Methods:The medical records of Professor Wang Pei's outpatient treatment for colon cancer were collected, entered into the Traditional Chinese Medicine Inheritance Computing Platform V3.0, and the laws of the prescription's nature, flavor, meridian, drug frequency, drug combination, association rules, and cluster analysis were explored.Results:A total of 65 prescriptions were collected, including 150 Chinese materia medica. The medicinal properties of these Chinese materia medica are mainly warm, cold and flat, the tastes were mainly sweet, bitter and pungent, and the meridians were mainly liver, spleen and kidney meridians. Dampness category and blood circulation promoting and blood stasis category were mainly used, and the most frequently used drugs include Poria, Polyporus, Scutellariae Barbatae Herba, Astragali Radix, Curcumae Rhizoma, and the pairs of Polyporus- Poria, Astragali Radix- Astragali Radix Praeparata cum Melle, Scutellariae Barbatae Herba- Curcumae Rhizoma. Twenty nine high-related drug pairs were obtained from association rules, including Polyporus- Astragali Radix Praeparata cum Melle- Astragali Radix, Poria- Scutellariae Barbatae Herba- Polyporus, Scutellariae Barbatae Herba- Curcumae Rhizoma- Polyporus. The cluster analysis showed the combination of 6 types of medicines mainly focuses on strengthening the spleen and removing dampness, nourishing qi and promoting blood, clearing heat and detoxifying, and astringing the intestines to stop bleeding. Conclusion:Professor Wang Pei mostly discusses the treatment of colon cancer from "spleen dampness, rectification deficiency, heat toxin, blood stasis, bleeding", and the treatment is "invigorating the spleen and removing dampness, invigorating Qi and strengthening the body, clearing away heat and detoxifying, promoting blood circulation and removing blood stasis, and astringent intestines to stop bleeding", which is in line with the thought of Traditional Chinese Medicine treatment of tumors, strengthening the righteousness and eliminating pathogenic factors, and and can be used for clinical reference.

Objective:To investigate the implication of micro RNA-21(miR-21) in Endostar combined with X-ray irradiation of cardiac fibroblasts (CF).Methods:Rat CFs were used in this experiment and been divided into the blank control group, 10 Gy X-ray irradiation group, Endostar group, 10 Gy X-ray+ Endostar group, 10 Gy X-ray+ Endostar+ NC mimic group (negative control 1), 10 Gy X-ray+ Endostar+ miR-21 mimic group, 10 Gy X-ray+ Endostar+ NC inhibitor group (negative control 2) and 10 Gy X-ray+ Endostar+ miR-21 inhibitor group. The proliferation of CF was determined by Methyl thiazolyl tetrazolium (MTT) assay. The expression level of Collagen Ⅰ protein was analyzed by Western blot. The expression levels of Collagen Ⅰ and miR-21 mRNA were assayed by real-time quantitative polymerase chain reaction (q-PCR).Results:In the 10 Gy X-ray+ Endostar+ miR-21 mimic group, the CF proliferation, Collagen Ⅰ and miR-21 mRNA were increased significantly compared with those in the blank control group, 10 Gy X-ray+ Endostar group, and negative control group 1 (all P<0.05). In the 10 Gy X-ray+ Endostar+ miR-21 inhibitor group, the CF proliferation and expression levels of Collagen Ⅰ mRNA were decreased significantly compared with those in the blank control group, 10 Gy X-ray+ Endostar group and negative control group 2(all P<0.05). Conclusions:The CF proliferation and Collagen Ⅰ expression are increased when the expression level of miR-21 gene is simulated. When inhibiting the expression of miR-21 gene, the CF proliferation and Collagen Ⅰ expression are reduced.

Objective:To explore the establishment of radiation-induced heart damage (RIDH) SD rat models caused by irradiation of 15Gy/3f and the changes in early detection indicators, and evaluate the effect of irradiation combined with recombinant human endostatin (Endostar).Methods:75 adult male SD rats were randomly divided into the blank control group (C group), Endostar group (E group), 25Gy irradiation group (MHD 25 group), 15Gy irradiation group (MHD 15 group) and 15Gy irradiation combined with Endostar group (MHD 15+ E group), respectively. Blood sample was taken to measure the CK, CK-MB, LDH and CRP at 24h, 48h and 15d after corresponding interventions. After cardiac echocardiography at 1, 3 and 6 months, 5 rats in each group were randomly sacrificed and myocardial tissues were collected for HE and Masson staining. Two-way ANOVA was employed for statistical analysis. Results:Compared with group C, myocardial fibrosis were observed in the MHD 15 group at 6 months ( P<0.05), which occurred later than that in the MHD 25 group. Ejection fraction (EF) and fractional shortening (FS) were significantly decreased after 3 months in each irradiation group (all P<0.05), whereas the degree of decrease was similar among all groups (all P>0.05). The expression levels of myocardial enzymes and inflammatory cytokines did not significantly differ among different groups (all P>0.05). Conclusions:In the early stage, exposure to 15Gy/3f irradiation can cause cardiac function damage in SD rat hearts, such as the reduction of EF and FS, and even lead to myocardial fibrosis in the late stage, which is delayed and less severe than high-dose irradiation. Irradiation combined with Endostar has no significant effect on radiation myocardial injury in rats.

Objective:To investigate the clinical effect of liver transplantation from organ donors in elderly patients.Methods:The clinical data of 346 patients who underwent liver transplantation in the general surgery center of Beijing You′an Hospital Affiliated to Capital Medical University from January 2018 to November 2020 were retrospectively analyzed. After screening, they were divided into the elderly donor group (30 cases) aged 60-70 years and the non elderly donor group (60 cases) aged < 60 years. The observation indexes were operation time, anhepatic phase time and operation bleeding. The prognosis indexes were: postoperative ICU stay, length of hospital stay, primary graft nonfunction (PNF), delayed graft function recovery (DGF) and in-hospital mortality. The measurement data in accordance with normal distribution are expressed as ( Mean± SD). The comparison between the two groups was analyzed by t-test. The measurement data that did not conform to the normal distribution were expressed as median (range). Mann Whitney U test was used for comparison between the two groups. The counting data were collected by the computer χ2 test or Fisher′s exact test analysis. Results:The operation time, anhepatic period and blood loss in the elderly group were (444.33±72.44) min, 56.0 (30-170) min, 1 992.1(400-9 000) mL, respectively and the non elderly group were (460.88±91.32) min, 58.45 (35-140) min, 1 885.8(400-12 000) mL, respectively, there were no significant difference between the two groups ( P>0.05); Among the prognostic indicators, the length of stay in ICU, the length of stay in hospital and the in-hospital mortality of the elderly group were 4.9 (2-21) d, 20.4 (3-40) d and 10% respectively, while the length of stay in ICU, the length of stay in hospital and the in-hospital mortality of the non elderly group were 5.3(1-32) d, 22.1(3-61) d and 10% respectively, with no significant difference between the two groups ( P>0.05); No PNF occurred in the two groups, but the incidence rate of DGF in the elderly group was 13.33%(4/30), and the non elderly group was 1.67%(1/60). There was a significant difference between the two groups ( P<0.05). Conclusion:Under strict preoperative donor evaluation and accurate recipient selection, 60-70 years old donors can achieve similar short-term effect as non elderly donors, but the long-term effect needs further observation.

Objective:To explore the anti-epidemic preventions and perioperative management strategies of organ donation and liver transplantation during the pandemic period of novel coronavirus pneumonia (NCP) and summarize the experiences.Methods:On the basis of guidance of National Health Commission and Organ Transplantation Committee of Chinese Medical Association, anti-epidemic preventions and perioperative management strategies of organ donation and liver transplantation were adjusted under the background of NCP pandemic and the anti-epidemic preventions and treatment outcomes were evaluated. Eight organ donations and 7 liver transplantations were performed from February 4 to March 7, 2020. NCP infection screening results were negative in all pre-donation and pre-transplantation cases.Results:All donation operations and liver transplantations were successfully performed without postoperative complications. No NCP occurred during hospitalization period. Postoperative pulmonary infection occurred in 1 case (1/7) and the following novel coronavirus screening result was negative. Pulmonary inflammation became partially absorbed after antibacterial therapy.Conclusions:Through strict and effective anti-epidemic preventions and perioperative managements, organ donation and transplantation could be successfully performed during the pandemic period of NCP.