Two kinds of gel materials were prepared from silk fibroin with polyepoxy compound at subfreezing temperature and higher temperature. In order to evaluate the feasibility of their application in biomaterials, we tested the cytotoxicity of silk fibroin gels by detecting the effect of the extracted liquid on the cell relative proliferation rate of L-929 mouse fibroblasts. The results indicated that both of the gel materials displayed high relative proliferation rate and grade 1 cytotoxicity, being in the allowed range of medical application. The cytotoxicity tests on polyepoxy compound and glutaraldehyde were conducted too, and the cytotoxicity of polyepoxy compound was obviously lower than that of glutaraldehyde. Polyepoxy compound can be used as a more safe cross-link reagent for silk fibroin modification.
Animals ; Biocompatible Materials ; chemistry ; Bombyx ; chemistry ; Cross-Linking Reagents ; chemistry ; Fibroblasts ; drug effects ; Fibroins ; chemistry ; Gels ; chemical synthesis ; toxicity ; Mice ; Polyethylene Glycols ; chemistry ; Temperature

Background Retinal pigment epithelium (RPE) cell transplantation is the primary means of human trial for the treatment of retinal degeneration.Induced pluripotent stem cells (iPSCs) will become an important source for cell transplantation.In addition,iPS-RPE cells may provide a personalized treatment platform for the patient's own cells treatment.Objective This study was to evaluate the feasibility of human fibroblasts differentiate toward iPSCs from retinitis pigmentosa (RP) patients and toward iPSC-RPE cells from non-RP individual by retroviral transfection of Oct4,Sox2,c-Myc and KLF4 genes.Methods Human thigh skin tissues were obtained from a RP patient with hotspot mutation of SNRNP200 p.S1087L and individual without SNRNP200 p.S1087L mutation,respectively,with the size 2 c m×3 cm.Human dermal fibroblasts were isolated and cultured by trypsin digestion and explant method.The fibroblasts were transfected by a series of retrovirus and cultured by human embyonic cellconditioned medium to generate and induce iPSCs,and then the iPSCs were identified by morphology,alkaline phosphatase (AP) staining and immunofluorescence assay of specific markers of pluripotent stem cells.iPSCs suspension were injected into SCID mouse to observe the tumorigenesis.The iPSCs from non-RP subject were induced to differentiate toward iPS-RPE cells by embryonic body (EB) inducing method,and iPS-RPE cells were identified by detecting the expression of RPE65,zonula occludens protein 1 (ZO-1) and lecithin retinol acyltransferase (LRAT).Results Cultured human dermal fibroblasts showed fusiform or polygon shape and intercellular close arrangement,and Vimentin was positively expressed in the cells.Small cell colonies were harvested 5-7 days after infected by retroviruses,and the morphology changed from spindle into round mass.The hESC-like iPSCs clonies appeared 20 days after cultivation,and the positive expressions of hESC-specific surface antigens including SSEA3,SSEA4,TRA-1-60,TRA-1-81 and Nanog were found in the cells 25-30 days after cultivation,and the positive staining of AP was obtained 12 weeks after cultivation.A teratoma was formed at the injection site of iPSCs suspension in SCID mouse.Immunofluorescence technique showed that RPE cell-specific proteins including RPE65,ZO-1 and LRAT proteins were positively expressed in iPS-RPE cells at 30 days after differentiation.Conclusions Mutation SNRNP200 p.S1087L of RP patient-specific iPSCs can be induced from human dermal fibroblast by retrovirus infection method.The function and morphology of the iPSCs were similar to hESCs.Human iPSCs cell line generated from the dermal fibroblasts of non-RP individuals can differentiate into iPS-RPE cells.

Recent researches about the application of silk fibroin in cell culture suggested that silk fibroin displayed high rate of cell attachment and growth in vitro culture of most kinds of cells, equivalent to collagen. So silk fibroin can be used for cell scaffold material of tissue engineering, and can be applied to several fields such as tissue engineering of skin, cartilage and blood vessel. The related researches and the prospect of the application of silk fibroin in cell scaffold of tissue engineering are reviewed in this paper.
Animals ; Biocompatible Materials ; Cell Adhesion ; Cell Culture Techniques ; Fibroins ; chemistry ; Humans ; Silk ; chemistry ; Tissue Engineering ; Tissue Scaffolds

Objective:To discuss effect of nicorandil on unstable angina patients With persistent Weakly positive for troponin I (TnI).Methods:A total of 111 unstable angina patients With persistent Weakly positive for TnI Were randomly divided into control group (received routine treatment,55 cases) and intervention group (received nic-orandil 5mg,3 times/d based on routine treatment,56 cases).The relief of chest pain in one Week,the recurrent hospitalization for chest pain aggravation in 3 months and the cardiac mortality rate in one year betWeen tWo groups Were observed in tWo groups. Results:Compared With control group,the relief of angina pectoris in one Week (63.6% vs. 91.1%,χ2=11.97,P=0.0005)significantly increased,re-hospitalization for chest pain aggravation in three months (56.4% vs.19.6%,χ2=15.91,P=0.0001)significantly decreased in intervention group;but cardiac mortality rate during one year betWeen tWo groups Was no significant difference (5.5% vs. 8.9%,χ2=0.50,P=0.4792).Conclusion:Nicorandil can significantly reduce the unstable angina and re-hospitalization for chest pain aggravation in patients With persistent Weakly positive for TnI,but there Was no significant difference in reducing mortality Within one year betWeen tWo groups.

Aim To explore the effects of chrysin on endothelial dysfunction induced by acute high glucose.Methods ① The effects of chrysin on normal isolated aortic at contraction induced by PE and on endothelial dysfunction induced by high glucose were tested in the following medium: normal group,chrysin group;normal-glucose group: glucose 11mmol·L-1 in Krebs' solution;high-glucose group: glucose 44 mmol·L-1 in Krebs' solution;mannitol group: mannitol 33 mmol·L-1 in Krebs' solution and chrysin group: 44 mmol·L-1 Glu+chrysin 1.0 μmol·L-1 in Krebs' solution.② The effects of chrysin on HUVEC cell viability after incubated in high glucose were observed in the following groups: normal-glucose group: glucose 5.5 mmol·L-1 in culture solution;high-glucose group: glucose 33.3 mmol·L-1 in culture solution;mannitol group: mannitol 27.8 mmol·L-1 in culture solution and chrysin group: chrysin(25,50 μmol·L-1)in culture solution.And the NO release was also testd in these groups.Results ① Chrysin could induce vaso-dilation in a dose-dependent manner at normal glucose.The Emax was(58.94±9.61)％,and the EC50 value was 51.9 μmol·L-1.After incubating the aortic rings with high glucose(44 mmol·L-1)for 4 h,there were significant differences in ACh-induced vascular relaxation between the normal glucose group and the high glucose group.The Emax was(32.12±3.92)％and the EC50 value was 78.0 μmol·L-1 of high glucose group(P<0.01).The endothelium-independent relaxation induced by SNP was not significantly different between the two groups.And chrysin(1.0 μmol·L-1)could reverse the decline of ACh-induced vasorelaxation response induced by high glucose(44 mmol·L-1).The Emax was(70.7±3.87)％and the EC50 value was 0.852 μmol·L-1.② The cell viability of HUVEC was depressed after incubated in high glucose,and chrysin could reverse the decline in a concentration-dependent way.And chrysin in defferent concentrations could increase the cell NO release.Conclusion Chrysin could prevent the acute high glucose-induced vascular endothelial dysfunction and could increase the NO release.

Objective To investigate the value of Ki-67 expression in the prognosis of triple negative breast cancer (TNBC) patients. Methods The expression of Ki-67 in 100 cases of TNBC was detected by EnVision method. According to the median of Ki-67, the patients were divided into low expression group and high expression group. The value of Ki-67 expression in the prognosis of TNBC was analyzed. Results The median Ki-67 was 30% . There were 52 cases in the Ki-67 low expression (≤ 30% ) group, and 48 cases in Ki-67 high expression (> 30% ) group. The expression of Ki-67 was correlated with histological grade, tumor size and lymph node status (P<0.01). Histological gradeⅠtoⅡ and primary tumor T1 were independent influencing factors of high expression of Ki-67 (P < 0.01). Kaplan-Meier analysis showed that Ki-67 was statistically related to disease-free survival (DFS) and overall survival (OS) (P<0.05). Univariate COX analysis showed that tumor size, lymph node status, Ki-67 were statistically correlated with DFS and OS (P<0.05). Multivariate analysis showed that tumor size, lymph node status, and Ki-67 were independent prognostic factors of DFS and OS (P<0.05 or<0.01). Primary tumors with T1, non-metastatic lymph nodes, and higher expression of Ki-67 in TNBC patients had longer DFS and OS (P < 0.01 or < 0.05). Conclusions Low expression of Ki-67 (≤ 30% ) is associated with poor disease stage and prognosis in TNBC. 30% may be the best cut-off value of Ki-67.

Adult ; Ataxin-1 ; genetics ; DNA Mutational Analysis ; Family Health ; Female ; Humans ; Male ; Middle Aged ; Pedigree ; Spinocerebellar Ataxias ; diagnosis ; genetics ; Trinucleotide Repeat Expansion ; genetics

Polybrominated diphenyl ethers (PBDEs), a kind of important Brominated Flame Retardant (BFR), are widely used in electronic products, construction materials and textiles. PBDEs have been detected in many environmental media (including air, water, dust, sediment and food), many animal and human tissues. For their environmental persistence, high bioaccumulative and multiple biotoxicitiies, PBDEs have been viewed as one of the most concerned environmental Endocrine Disrupting Chemicals (EDCs) at present. Although detailed mechanisms are not clear, studies have found that PBDEs can induce toxicity to liver, endocrine system, nervous system, reproduction and immune system. What's more, lots of experiments indicate that PBDEs exposure can alter the levels of thyroid hormones. Recently, studies on the impact of PBDEs exposure on thyroid hormones have been quite a few and have not reached an agreement, especially on the alternation of thyroid hormones caused by PBDEs exposure, which has also been a hot issue. This paper reviews from the basic properties, usage, exposure and biotoxicity of PBDEs. We mainly introduce the impact PBDEs have on the thyroid and thyroid hormones in terms of biotoxicity, and attach importance to the endocrine disruption and neurodeveloptoxicity. We also give a preliminary introduction to hydroxylated and methoxylated polybrominated diphenyl ethers, structural analogs of PBDEs, which researchers start late to study. This paper can be a reference for the further research on PBDEs exposure and biotoxicity.

Objective:To explore the epidemiological factors of patients with OHCA who did not attempt CPR, and analyze the reasons and clinical features of non resuscitation.Methods:Data from OHCA patients who did not undergo CPR were collected from January 2020 to December 2020 at Beijing Emergency Medical Center. The registration form was designed according to the Utstein model, and the data were analyzed retrospectively by the chi-square test.Results:A total of 5 977 patients were enrolled and divided into two groups according to age: 2 349 patients aged ≤ 80 years old and 3 628 patients aged ≥ 81 years old. Compared with the younger group, the proportion of patients in the older group who did not undergo CPR due to disease (97.0%) and family desertion (99.4%) were higher, and the difference was statistically significant (both P<0.01). Conclusions:Elderly people over 80 years old with underlying diseases have a high probability of developing OHCA at home. Most of the witnesses at the scene were family members and could not implement CPR in time. After the emergency personnel arrived at the scene, they found that the patient had been in cardiac arrest for too long and had apparently died. Family members would choose to give up treatment.

Objective:To analyze the clinical characteristics of patients with cardiac arrest caused by poisoning, explore the differences in the corresponding emergency measures and emergency effects under different causes of poisoning, and improve the success rate of out-of-hospital cardiac arrest rescue.Methods:All out-of-hospital toxic cardiac arrest patients admitted to Beijing Emergency Medical Center from January 2021 to December 2021 were retrospectively included.Results:A total of 38 patients with a median age of 43 years, including 26(68.4%) were male. There were 20 cases of acute alcoholism (52.6%), and 9 (23.7%) cases of carbon monoxide and drug poisoning respectively. In 38 cases, only 2 cases achieved return of spontaneous circulation, and no cases survived more than 24 hours.Conclusions:Poisoning induced cardiac arrest is one of the non-cardiac causes of out-of-hospital cardiac arrest, responsible for 1.7%. Alcoholism is the main poisoning cause of noncardiac out-of-hospital cardiac arrest in Beijing, prevent the poisoning and quickly identify the cause of the poisoning and give the correct rescue measures is very important for cardiac arrest.