BACKGROUND:With the development of tissue engineering, autologous chondrocyte implantation is often used to repair cartilage defects. And poor integration is one of the common reasons that lead to failure repairing. Many models in vitro are used for related studies.
OBJECTIVE:To develop an interface integrated model of tissue engineered cartilage repair in vitro and to evaluate the effect.
METHODS:Cartilage integration model in vitro was established in pigs. Total y 21 cartilaginous rings were obtained and divided into agarose gel group (n=18) and control group (n=3). In agarose gel group, cartilage rings were covered with agarose gel. Chondrocytes were separated and implanted into the ring. The leakage of cells around the cartilage rings was observed. The sections were stained for histological observation at 1, 2, 4 weeks. The average area of neochondrocytes was measured and compared.
RESULTS AND CONCLUSION:The results from the control group were not processed, because there was no chondrocyte aggregate formation in the center of the explant ring due to earlier chondrocyte leakage outside the explant. While no chondrocytes were found outside the explant ring in the agarose gel group. Tissue sections of the agarose gel group were stained by hematoxylin and eosin, alcian blue, Safranin-O and col agen type II immunohistochemistry at 1, 2, 4 weeks. Neochondrocytes proliferated within cartilage ring, and produced extracellular matrix. After 2 weeks of incubation, these inserted chondrocytes were significantly increased. There was no statistical y significant increment between 2 weeks and 4 weeks (P>0.05), although the area was further increased by 4 weeks. This model provides a convenient simulation of the cartilage integration process in vitro and has a potential application in studies of cartilage integration and cartilage tissue engineering.

Objective:To analyze the epidemiological characteristics and co-infections of pathogens in children with pneumonia in autumn and winter of 2019 in Qingdao.Methods:From August to November in 2019, 77 children with pneumonia in three hospitals in Qingdao were selected as the research subjects. Throat swabs were collected, nucleic acid was extracted, and 20 common respiratory pathogens were detected by single tube multiplex PCR.Results:Among the 77 cases, the incidence of pneumonia in boys (53.2%) was slightly higher than that in girls (46.7%). Children aged 1-2 years accounted for 10.3% of the total cases, children aged 3-6 years accounted for 61%, and children aged 7-13 years accounted for 20.7%. Twenty-nine cases (38.10%) had high white blood cells; 16 cases (20.77%) had high neutrophil count; 30 cases (38.96%) had high lymphocyte count; the pathogen detection rate was 77.92% of cases, among whom Mycoplasma pneumoniae (MP) was 59.74%, Bocavirus was 10.39%(8/77), adenovirus was 7.79% (6/77), rhinovirus was 3.89% (3/77), parainfluenza virus type 4 was 3.89% (3/77), Bordetella pertussis was 3.89% (3/77), parainfluenza virus type 2 was 2 2.59% (2/77), coronavirus nl63/hku1 was 2.59% (2/77), coronavirus OC43 was 2.59% (2/77), human metapneumovirus was 1.29% (1/77), Parainfluenza virus type 3 was 1.29%(1/77). The 24 cases of virus infection accounted for 31.16% (24/77). The co-infection with two pathogens accounted for 18.18%.Conclusions:Many kinds of pathogens were detected in children with pneumonia in autumn and winter of 2019, in Qingdao. The prevalence of Mycoplasma pneumoniae infection was the highest. Many common viral infections were found in the cases. A high proportion of co-infection was detected in these pneumonia cases.

Objective:To explore the effect of situational simulation interactive training on rehabilitation compliance and motor function of stroke patients with hemiplegia.Methods:A total of 140 hemiplegic patients with stroke from July 2017 to October 2019 in Beijing Rehabilitation Hospital Affiliated to Capital Medical University were selected and divided into control group and observation group, 70 cases in each group. Routine treatment and rehabilitation nursing were used in the control group, and situational simulation interactive training were used in the observation group on the basis of the control group. Both groups were followed up for 6 months. Fugl-Meyer Assessment (FMA), World Health Organization Quality of Life Scale Brief (WHOQOL-BREF), Fugl-Meyer Assessment (FMA), self-made rehabilitation training compliance questionnaire and self-made nursing satisfaction questionnaire were used to evaluate the quality of life, motor ability, cognitive ability before intervention and after follow-up, rehabilitation compliance and nursing satisfaction after follow-up of the two groups.Results:There was no significant difference in FMA, WHOQOL-BREF and MMSE scores between the two groups before intervention ( P>0.05). After follow-up, the scores of FMA, WHOQOL-BREF and MMSE in the observation group were 62.57±6.52, 80.65±9.25, 25.30±3.24, significantly higher than 52.68±7.23, 66.68±8.34, 20.36±3.12 in the control group, the difference was statistically significant ( t value was 8.499, 9.385,9.189, P<0.05). After follow-up, the total compliance rate and satisfaction rate of the observation group were 92.86% (65/70) and 94.29% (66/70), respectively, while those of the control group were 78.57% (55/70) and 80.00% (56/70), respectively, the difference between the two groups was statistically significant (Fisher's exact test, P<0.05). Conclusions:The situation simulation rehabilitation training can effectively improve the motor function, rehabilitation compliance and nursing satisfaction of stroke patients with hemiplegia.

Objective:To explore the prognostic value of BRCA1-associated protein 1 (BAP1) expression loss in patients with malignant mesothelioma (MM) .Methods:A total of 82 MM patients from January 1998 to December 2017 in Zhejiang Province were selected to detect the expression of BAP1 protein by immunohistochemical analysis. Kaplan-Meier method was used to draw the survival curve, and multivariate Cox proportional risk model was used to analyze the factors affecting the survival rate.Results:Among 82 MM patients, 61 (74.4%) were female, aged (57±11) years. BAP1 protein expression was deficient in 39 patients (47.6%). The survival rate was correlated with the loss of BAP1 protein expression and age (χ 2=5.27, 5.66, P=0.022, 0.017). Subgroup analysis showed that loss of BAP1 protein expression was associated with better prognosis in MM patients <57 years of age, female, pleural MM, epithelial MM, and treated with drugs or surgery ( P<0.05). Multivariate model results showed that positive expression of BAP1 protein ( HR=3.75, 95% CI: 2.23-6.30, P<0.001) and age ≥57 years ( HR=1.66, 95% CI: 1.01-2.72, P=0.049) were risk factors for survival in patients with MM. Conclusion:Loss of BAP1 protein expression may be an independent prognostic factor in patients with MM, which is associated with longer survival.

Background::Cancer immunotherapy has emerged as a promising strategy against triple-negative breast cancer (TNBC). One of the immunosuppressive pathways involves programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1), but many patients derived little benefit from PD-1/PD-L1 checkpoint blockades treatment. Prior research has shown that MYC, a master transcription amplifier highly expressed in TNBC cells, can regulate the tumor immune microenvironment and constrain the efficacy of immunotherapy. This study aims to investigate the regulatory relationship between MYC and PD-L1, and whether a cyclin-dependent kinase (CDK) inhibitor that inhibits MYC expression in combination with anti-PD-L1 antibodies can enhance the response to immunotherapy. Methods::Public databases and TNBC tissue microarrays were used to study the correlation between MYC and PD-L1. The expression of MYC and PD-L1 in TNBCs was examined by quantitative real-time polymerase chain reaction and Western blotting. A patient-derived tumor xenograft (PDTX) model was used to evaluate the influence of a CDK7 inhibitor THZ1 on PD-L1 expression. Cell proliferation and migration were detected by 5-ethynyl-2′-deoxyuridine (EdU) cell proliferation and cell migration assays. Tumor xenograft models were established for in vivo verification. Results::A high MYC expression level was associated with a poor prognosis and could alter the proportion of tumor-infiltrating immune cells (TIICs). The positive correlation between MYC and PD-L1 was confirmed by immunostaining samples from 165 TNBC patients. Suppression of MYC in TNBC caused a reduction in the levels of both PD-L1 messenger RNA and protein. In addition, antitumor immune response was enhanced in the TNBC cancer xenograft mouse model with suppression of MYC by CDK7 inhibitor THZ1. Conclusions::The combined therapy of CDK7 inhibitor THZ1 and anti-PD-L1 antibody appeared to have a synergistic effect, which might offer new insight for enhancing immunotherapy in TNBC.

Objective:To explore the prognostic value of BRCA1-associated protein 1 (BAP1) expression loss in patients with malignant mesothelioma (MM) .Methods:A total of 82 MM patients from January 1998 to December 2017 in Zhejiang Province were selected to detect the expression of BAP1 protein by immunohistochemical analysis. Kaplan-Meier method was used to draw the survival curve, and multivariate Cox proportional risk model was used to analyze the factors affecting the survival rate.Results:Among 82 MM patients, 61 (74.4%) were female, aged (57±11) years. BAP1 protein expression was deficient in 39 patients (47.6%). The survival rate was correlated with the loss of BAP1 protein expression and age (χ 2=5.27, 5.66, P=0.022, 0.017). Subgroup analysis showed that loss of BAP1 protein expression was associated with better prognosis in MM patients <57 years of age, female, pleural MM, epithelial MM, and treated with drugs or surgery ( P<0.05). Multivariate model results showed that positive expression of BAP1 protein ( HR=3.75, 95% CI: 2.23-6.30, P<0.001) and age ≥57 years ( HR=1.66, 95% CI: 1.01-2.72, P=0.049) were risk factors for survival in patients with MM. Conclusion:Loss of BAP1 protein expression may be an independent prognostic factor in patients with MM, which is associated with longer survival.

Objective:To understand the prevalence of coxsackievirus A6 (CV-A6) in hospitalized patients with hand, foot and mouth disease in autumn and winter of 2019, and the genetic characteristics of VP1 region and the relation-ship between germline evolution.Methods:A total of 104 throat swabs from hospitalized patients with hand, foot and mouth disease in Qingdao in autumn and winter of 2019, and screen positive specimens were collected using enterovirus universal real-time PCR technology. Then the universal typing primers in the VP1 region were used to amplify the positive samples, the amplified segments were sequenced and BLAST comparison was performed. CV-A6 VP1 full-length primers were used to amplify the BLAST comparison of CV-A6 positive samples, sequence the ampli-fied products, analyze the homology of nucleotides and amino acids through DNAstar and MEGA software, and construct a phylogenetic tree.Results:Among 104 throat swab samples, 60 were positive for enterovirus, and the overall positive rate was 57.7%, of which the positive rate of CV-A6 was 26.9% (28/104), and the rate of coxsackievirus A16 (CV-A6) was 30.8% (32/104). Twenty-eight CV-A6 positive samples were subjected to full-length amplification, sequencing, comparison and homology analysis of the VP1 region, and 22 positive sequences were obtained. The nucleotide homology was 93.6% to 99.9%, and the amino acid homology was 98.0%-100%. Phylogenetic analysis showed that 22 CV-A6 strains belonged to the D3 subtype in the D genotype.Conclusions:The pathogens causing hospitalized hand, foot and mouth disease in Qingdao in autumn and winter of 2019 were CV-A6 and CV-A16. The prevalent strains of CV-A6 were mainly D3 subtypes.

【Objective】 To investigate the effect of Polymerized human cord hemoglobin (PolyCHb) on the sensitivity of hepatocellular carcinoma grafts to lumvalatinib in nude mice. 【Methods】 Hep3B hepatoma cells were subcutaneously transplanted in 18 nude mice to establish tumor graft model. Mice were randomly divided into 3 groups: control group (the saline 90 mg·kg^-1·d^-1), monotherapy group (Lenvatinib10 mg·kg^-1·d^-1), and sensitized group (Lenvatinib mg·kg^-1·d^-1, polyCHB 600 mg/kg twice a week) for 28 days. The tumor volume was measured regularly and the growth curve was drawn. On day 29, the nude mice were sacrificed, the tumor was stripped and weighed, and the pathomorphological differences of each group were evaluated by HE section staining. The expression levels of hypoxia-inducing factor (HIF-1α), CD34, VEGF, CD44, MMP-9, and Glut-1 in tumor tissues of each group were determined by immunohistochemistry. The content of reactive oxygen species (ROS) in tumor tissues of each group was determined by dihydroethyl ingot method. 【Results】 The tumor growth rate and tumor volume in the sensitized group decreased significantly compared with the control group and the solo drug group. On day 29, the tumor volumes of the control group, the monotherapy group and the sensitization group were (2 076.46±350.25)mm^3, (1 035.96±84.16)mm³ and (892.66±104.46)mm^3, respectively. Tumor weight was (1.61±0.52)g, (0.45±0.10)g, and (0.34±0.13)g, respectively. Immunohistochemical score of HIF-1α was 75±23 vs 45±18 vs 18±11, VEGF was 52±8 vs 67±16 vs 35±4, CD34 was 40±7 vs 50±13 vs 28±7, CD44 was 37±15 vs 30±7 vs 15±3, Glut-1 was 74±41 vs 51±30 vs 14±18, MMP-9 was 51±7 vs 62±20 vs 33±3, respectively(P<0.05). The malignant degree of the sensitized group was decreased by HE section staining, which was significantly lower than that of the solo drug group and the control. The ROS content in the sensitized group was higher than that in the solo drug group and the control. 【Conclusion】 PolyCHb can reduce the expression of HIF-1α and its downstream pathway related molecules by increasing oxygenation of hepatocellular carcinoma tissues in nude mice, delay tumor growth and reduce tumor volume in a certain period, thus increase the therapeutic effect of lenvalatinib on hepatocellular carcinoma grafts in tumor bearing nude mice models.

【Objective】 To investigate the effect of polymerized human cord hemoglobin (PolyCHb) on the chemosensitivity of human breast cancer MCF-7 cell subcutaneous xenografts in nude mice and its mechanism. 【Methods】 The MCF-7 cells in exponential growth phase were collected and made into suspension cells at a density of 5×10⁷ cells/mL.Subsequently, the cells were inoculated subcutaneously in the right limb of 18 BALB/c-nu nude mice with 0.2 mL cells per mouse to establish subcutaneous xenograft.When the tumor volume reached about 100 mm³, they were randomly divided into chemotherapy group: doxorubicin 5 mg·kg^-1, once/week; chemotherapy + PolyCHb group: in addition to doxorubicin (chemotherapy group), PolyCHb 600 mg·kg^-1, 3 times/week; the control group: normal saline 90 mg·kg^-1, once/week; all were injected through tail vein continuously for 4 weeks.From the day of injection (d 0), the tumor volume of each group of nude mice was measured every 3 days, and the tumor growth curves were drawn accordingly.After 38 days, the tumor growth observation was completed.The tumor was removed and weighed to calculate the tumor inhibition rate.HE staining, immunohistochemistry and TUNEL method were used to observe the pathological changes of tumor tissue, detect the expression of HIF-1α, and detect tumor cell apoptosis respectively.The content of reactive oxygen species (ROS) of each group was determined by fluorescence staining. 【Results】 The tumor volume (mm³) of chemotherapy + PolyCHb group, chemotherapy group and the control group at day 38 were 196.35±103.45 vs 316.29±62.88 vs 519.42±177.33 (P<0.05), and the tumor inhibition rate (%) of chemotherapy + PolyCHb treatment group and chemotherapy group was 62.20 vs 39.11, respectively.HE staining and TUNEL detection showed that cell necrosis and apoptosis in the growth area of tumor tissue increased in chemotherapy + PolyCHb group.Immunohistochemistry and fluorescence staining showed that HIF-1α expression in chemotherapy + PolyCHb group decreased and reactive oxygen species (ROS) content increased. 【Conclusion】 PolyCHb increases the chemosensitivity of subcutaneous xenograft in nude mice with breast cancer, and its mechanism may be related to the increase of ROS in tumor tissue and the promotion of tumor cell apoptosis.

【Objective】 To investigate the application prospect of platelet-rich plasma lysate (PL) microneedles in the treatment of wound healing by optimizing the preparation process and evaluating the activity of platelet growth factor. 【Methods】 Firstly, hyaluronic acid (HA) was used as needle matrix material, and the concentration of HA was preliminarily determined by investigating the fluidity of HA solution, shape of needle, pressure change performance and puncture performance.Combined with the results of HA dissolution in PL, mechanical properties of PL microneedles and skin puncture, the preparation process of platelet-rich plasma lysis microneedles (PLMN) was optimized to investigate the growth factor activity of PLMN and evaluate the effect of PLMN on wound healing in rats. 【Results】 When the concentration of HA was 30 mg/mL, the solution had good fluidity.The HA microneedles could pierce three layers of sealing film, with the puncture rate at 70%, and the solution had good mechanical properties.When HA was dissolved in PL at a concentration of 30 mg/mL at 4℃, the solution had no crystallization and was with good fluidity.The prepared PLMN showed good needle shape and no bending under HD microscope and scanning electron microscope.In vitro transdermal simulation results showed that PLMN could penetrate 4 layers of sealing membrane, and the puncture rate of the first three layers was more than 85%.In vivo lysis experiment showed that PLMNs could be completely dissolved within 10 min after being inserted into the body.Forty minutes later, the micropores left after the insertion of the microneedle were almost closed, without redness, swelling, erythema and other adverse reactions.In vitro and in vivo transdermal experiments showed that clear blue holes were visible after PLMNs penetrated the skin stain, indicating that the microneedles could pierce the skin barrier.Growth factor detection results showed that the content of platelet-derived growth factor (PDGF-BB) and transforming growth factor (TGFβ1) in platelet lysate were (17.67±1.23) ng/mL and (105.95±2.16) ng/mL, respectively.After PLMNs were prepared and stored at room temperature for 1 week, the content of PDGF-BB(ng/mL) and TGFβ1(ng/mL) were 15.48±2.12 and 56.26±1.53, respectively.Compared with PL(vs 17.67±1.23 and 105.95±2.16), the content of PDGF-BB and TGFβ1 decreased, but still maintained the activity of growth factors.The results of wound healing experiment in rats showed that the wound healing rate (%) of PLMN group on the third day was significantly different from that of the control group(52.51±6.15 vs 33.31±3.60, P<0.05). 【Conclusion】 The PLMN prepared in this experiment has good mechanical properties and can successfully pierce the skin cuticle.It can also maintain the activity of growth factors, and has a good effect on wound healing in rats, which provides a new idea for minimally invasive treatment in the field of tissue repair.