BACKGROUND: The strength and elasticity of general starch can be enhanced dramatically after plastic blends. The major characters of this material are magnitude molecular weight, many enwinded points, extreme containment of small molecules,and great gelation ability. It can be used as a biodegradable replacement of alginate. Furthermore, by adding osteoinductive factors, thermoplastics starch (TP) can be used as an organic engineering material, which can provide dual functions:anti-bleeding and bone formation. TP can also be used as intraoral tissue formation membrane and burn dressings.OBJECTIVE: To evaluate the bio-safety of TP through a cytotoxicity test.DESIGN: A controlled observation.SETTING: Beijing Research Institute of Traumatology and Orthopaedics; Beijing Jishuitan Hospital; Beijing University of Chemical Technology; Peking Univesity School of Stomatology.MATERIALS: The experiment was conducted at the laboratory of Beijing Research Institute of Traumatology and Orthopaedics from April to October in 2006. TP sample was obtained by plasticization of corn starch (12 wt % water content) with glycerol in a Haake Rhenmix at 110℃ and with 80 rounds per minute for 25 minutes, elongation at break from 115.3% to 245.3%. It was prepared by Beijing Key Laboratory for Preparation and Processing of Novel Polymeric Materials, Beijing University of Chemical Technology. Mouse fibroblast L-929 cell strain was provided by the cell bank of Peking University Health Science Center.METHODS: 1 × 107 L-1 cell aqueous suspension was cultured into leaching liquor ( 50% ), serving for TP group, and routine culture medium served for negative control group. Effect of TP on relative growth rate of L-929 cell strain was quantitatively measured by MTI" assay. The cytotoxicity of TP was evaluated according to GB/T16175-1996. Morphological changes and proliferation of cells were observed after2, 4, and 7 days of culture in the medium through an inverted phase contrast microscope.MAIN OUTCOME MEASURES: Cytotoxicity, morphological changes and proliferation of cells, and cell relative growth rate.RESULTS: Cytotoxicity: After 2 and 4 days of incubation, the absorbance (A) value was lower in the TP group than in the negative control group. After 7 days of incubation, the A value was significantly higher compared to negative control group (P＜0.01). It indicated that after 2 and 4 days of incubation, the cytotoxicity in the TP group was larger than in the negative control group, while after 7 days of incubation, it was on the opposite. All the test time, TP's cytotoxicity grade ranged from 0 to 1. Morphological change and proliferation of cells: After 2 days of incubation, both groups of cells were not extended to the outside of the scope, with a majority shape of being round, triangle, and quadrangle in the TP group or fusiform cells in the negative control respectively. Four days later, there were gaps among cells in the TP group, while in the negative control group, there were hardly any distance between cells and some cells piled up. Seven days later, cells in starch medium suddenly grew up to such a degree that all the cells lapped over and presented with more bloom than the negative control. Cell relative growth rate: After 2, 4, and 7 days of incubation, relative growth rate increased with time, being 85.63%,82.22%, and 113.05%, respectively.CONCLUSION: TP has no evidence of cytotoxicity and has good bio-safety.

Objective: To evaluate the effects and partly mechanism of Qileng decoction(QLD,芪棱汤) resisting focal cerebral ischemia/reperfusion(I/R) injury in rats by apoptosis and signal transduction pathway.Methods: The rats were randomly divided into three groups including sham operation group,normal saline(NS) control group and QLD group.The model of focal cerebral I/R injury was induced by using modified thread embolizing in rats.Rats were evaluated by neurologic function score at 2 hours after ischemia and 2,4,6,12,24 and 48 hours after cerebral reperfusion,and the pathological changes of nerve cells and mitochondria ultrastructure at pallium and hippocampus CA1 region were observed at 24 hours after reperfusion.Immunohistochemical method was performed to examine the expression of cytochrome C(cyt C) and caspase-9 at different time points after reperfusion.Apoptosis of nerve cells in ischemic penumbra(IP) was also characterized by terminal deoxynucleotidyl-transferase mediated dUTP-biotin nick end labeling(TUNEL) method.Results: Compared with NS control group,neurologic function scores at different reperfusion time points were improved and the pathological changes were ameliorated at 24 hours after cerebral I/R in QLD group.Mitochondria hydropsia was alleviated,mitochondrial cristae fragmentation and granulum basale shedding were diminished,and mitochondrial basical morphology was retained.Meanwhile,apoptosis index(AI) was decreased and the expressions of cyt C and caspase-9 were reduced in IP in QLD group.Conclusion: QLD intervenes in mitochondria mediated and caspase-9 dependent apoptopic pathway.QLD lowers AI and plays a role of protecting nerve by maintaining mitochondrial basical form,stabilizing mitochondrial membrane and inhibiting the release of cyt C and activation of caspase-9.The above actions are possibly some parts of mechanisms of QLD resisting focal cerebral I/R injury.

Objective To discuss the expression and clinical significance of microRNA(miR)- 766 in chil-dren with polyarticular juvenile idiopathic arthritis (poly - JIA). Methods A total of 23 children with poly - JIA who received treatment at the Department of Rheumatology,the Affiliated Children′s Hospital of Capital Institute of Pediat-rics,from November 2014 to September 2016,were enrolled as research group,and 24 healthy children at the same age were selected as healthy control group,while 24 children with oligoarticular juvenile idiopathic arthritis (oligo - JIA) and 19 children with juvenile ankylosing spondylitis (JAS)were selected as case - control groups. The expression lev-els of miR - 766 in plasmas were detected by real - time quantitative polymerase chain reaction (qPCR). The clinical diagnostic values were analyzed by operating characteristic curve (ROC). Correlations between the expression levels of miR - 766 and clinical,laboratory results were analyzed by conducting Pearson correlation coefficient analysis. Results Compared with the healthy control group and case - control group,the expression levels of miR - 766 in poly - JIA group decreased,and the differences were statistically significant (t = 6. 897,6. 446,6. 218,all P < 0. 001). There was no statistical difference of miR - 766 levels in plasma between case - control groups and healthy control group (P >0. 05). Compared with the healthy control group,the area under ROC curve of miR - 766 was 0. 938 (95％ CI:0. 872 -1. 000),and when the cutoff value of miR - 766 was 6. 083 pmol/ L,the sensitivity was 87. 0％ and the specificity was 91. 7％ . Compared with oligo - JIA and JAS,the area under ROC curves of miR - 766 was 0. 908 (95％ CI:0. 819 -0. 996)and 0. 927 (95％ CI:0. 865 - 1. 000),respectively. Correlation analysis indicated that the level of miR - 766 in plasma of poly - JIA children was positively associated with hemoglobin (r = 0. 651,P < 0. 001),but negatively asso-ciated with the 28 - joint Disease Activity Score (DAS28)and the percentage of type 1 helper T cells(Th1％)(r =- 0. 434,P = 0. 038;r = - 0. 417,P = 0. 008). Conclusions The expression levels of plasma miR - 766 in poly - JIA are significantly decreasing. miR -766 may serve as an evaluation indicator for the diagnosis and prognosis of poly - JIA.

Objective:To investigate the proportion of helper T lymphocytes 22(Th22) and levels of interleukin(IL)-22 in peripheral blood of children with juvenile idiopathic arthritis (JIA), and analyze their relevance with JIA-related inflammatory cytokines.Methods:A total of 30 children with JIA who received treatment at the Department of Rheumatology, the Affiliated Children′s of Capital Institute of Pediatrics from November 2018 to December 2019 were enrolled as JIA group, and 12 healthy children at the same age were selected as healthy control group.The percen-tage of Th22 cells in peripheral blood was detected using flow cytometry.Concentrations of IL-22, IL-6, tumor necrosis factor(TNF-α), IL-17 and IL-10 were measured by enzyme-linked immunosorbent assay.Statistical analysis of the relevance of Th22 cells, IL-22 levels and inflammatory cytokines levels of IL-6, TNF-α, IL-17 and IL-10 in JIA were performed by Pearson test. Results:The proportion of Th22 cells in peripheral blood of patients in JIA group[(0.94±0.26)%] was higher than that of the healthy control group [(0.46±0.29)%], and the difference was statistically significant ( t=2.227, P<0.05). Plasma level of IL-22 of patients in JIA group[(185.2±11.93) ng/L] was significantly higher than that of healthy control group[(114.7±6.29) ng/L], and the difference was statistically significant ( t=3.632, P<0.001). The proportion of Th22 cells and the levels of plasma IL-22 in JIA patients were positively correlated with plasma levels of IL-6 (Th22: r=0.501, IL-22: r=0.573, all P<0.01), IL-17 (Th22: r=0.686, P<0.001; IL-22: r=0.445, P<0.01) and IL-10 (Th22: r=0.609, IL-22: r=0.284, all P<0.001). There was no relationship for Th22 cells and plasma levels of IL-22 with TNF-α. Conclusions:The proportion of Th22 cells and plasma levels of IL-22 significantly increase in peripheral blood of JIA patients and correlated with JIA-related inflammatory cytokines, which may play a potential role in the pathogenesis of JIA disease.

Objective:To study the role of serum E-selectin and P-selectin in pathogenesis of severe Mycoplasma pneumonia pneumonia(MPP), and to evaluate their value in early clinical recognition of severe MPP.Methods:The clinical data of 87 MPP patients in the Respiratory Ward of Capital Institute of Pediatrics Children′s Hospital between December 2017 and October 2018 were collected.Children were divided into the mild group(37 cases)and the severe group (50 cases) according to the severity of the disease.There were 20 males and 17 females in the mild group, with the age of (7.62±2.02) years.There were 17 males and 33 females in the severe group, with the of (6.97±2.41) years.Serum E-selectin, P-selectin and related inflammatory indicators were measured and compared between the two groups, and their correlation with severe MPP was analyzed.The receiver operating characteristic curve (ROC) analysis was also conducted.Results:The length of stay [(8.46±2.53) d vs.(5.19±1.20) d, P<0.001], C-reactive protein(CRP)[(23.05±37.05) mg/L vs.(15.06±13.79) mg/L, P=0.001], lactate dehydrogenase(LDH)[(342.50±186.00) U/L vs.(284.44±64.82) U/L, P<0.001], procalcitonin(PCT)[(0.19±0.26) μg/L vs.(0.15±0.14) μg/L, P=0.012], serum ferritin(SF)[(197.33±429.43) μg/L vs.(124.60±66.30) μg/L, P<0.001], D-Dimer [(539.00±576.00) μg/L vs.(226.00±170.50) μg/L, P<0.001], E-selectin [(2.36±4.22) μg/L vs.(0.86±0.20) μg/L, P<0.001] and P-selectin [(4.15±4.40)μg/L vs.(1.72±1.22) μg/L, P<0.001] in the severe group were significantly higher than those in the mild group.There was no statistical difference in the white blood cell (WBC) and erythrocyte sedimentation rate(ESR). CRP, LDH, SF, D-Dimer, E-selectin and P-selectin were statistically correlated with severe MPP(all P<0.05), while WBC, PCT and ESR were not statistically correlated with severe MPP.The areas under ROC of CRP, LDH, SF, D-Dimer, E-selectin and P-selectin were all greater than 0.5, and the area under ROC of E-selectin was the largest, followed by that of P-selectin(both>0.8). Conclusions:Severe MPP may lead to excessive inflammatory reactions in the body.E-selectin and P-selectin possibly play an important role in this process, and can act as good indicators for early recognition of severe MPP.

ObjectiveTo investigate the effects of acupuncture combined with Du-Moxibustion (ADM) on peripheral blood cell count and levels of immune factors in patients with occupational chronic benzene poisoning. Methods A total of 70 patients with occupational chronic benzene poisoning (leukopenia and neutropenia) were selected as the research subjects by judgement sampling method. They were randomly divided into a control group and an ADM group using a random number table method, with 35 cases in each group. Patients in the control group were treated with conventional Western medicine such as leukocyte boosting and symptomatic treatment. While patients in the ADM group were treated with ADM treatment in addition to treatments of the control group, once per week for five consecutive weeks. Peripheral blood samples of patients were collected before and after treatment from both groups, to detect cell counts and serum levels of immune factors. Results The white blood cell count, red blood cell count, absolute lymphocyte count, absolute neutrophil count, platelet count, and levels of hemoglobin, immunoglobulins (Ig) A, IgM, IgG, complement C3 and complement C4 of patients in both groups improved after treatment compared with those before treatment (all P<0.05). The white blood cell count, levels of IgA, IgM, IgG, complement C3 and complement C4 of patients in the ADM group were higher than those in the control group after treatment (all P<0.05). Conclusion ADM treatment can increase peripheral blood white blood cells and serum levels of immune factor in patients with occupational chronic benzene poisoning (leukopenia, neutropenia), which helps improve patient recovery and can be promoted clinically.

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 construct T cell receptor β (TCRβ) repertoires in children with SARS-CoV-2 infection, and analyze the differences in TCRβ repertoires between children with SARS-CoV-2 infection and healthy children.Methods:Whole blood samples from 5 children infected with SARS-CoV-2 Delta variant and from 5 healthy children were collected. After RNA quality inspection and repertoires construction, high-throughput sequencing was conducted to analyze the differences in clonal expansion and diversity indices of the TCR repertoires between children infected with SARS-CoV-2 and healthy children. The frequency of use of TCRβ VJ genes was statistically analyzed using unpaired T-tests.Results:We successfully constructed the TCRβ repertoires of children infected with SARS-CoV-2 using high-throughput sequencing technology. The diversity index of the TCR repertoire in children infected with SARS-CoV-2 (9.78±1.23) was significantly lower compared to that in healthy children (13.40±2.12) ( P<0.05), and the TCR clonal expansion index in children infected with SARS-CoV-2 (0.18±0.07) was significantly higher compared to that in healthy children (0.06±0.06) ( P<0.05). A preliminary comparison of the frequency of use of TCRβ repertoire VJ genes found that, in children infected with the SARS-CoV-2, the most common V and J genes were TRBV28 and TRBJ2-1, respectively. Conclusions:The construction of the TCRβ repertoires in children infected with SARS-CoV-2 using high-throughput sequencing technology has revealed characteristic features of the TCRβ repertoires in these children. This is of significant reference value for unveiling the characteristics of the T-cell repertoires in children infected with SARS-CoV-2 and for the rapid construction of TCRβ immunological repertoires in other viral infections.

Objective:To investigate the effects of Clostridium butyricum on colitis and intestinal microbiota in mice with or without antibiotic pretreatment. Methods:Thirty specific pathogen free BALB/c mice were randomly divided into the blank control group, dextran sulfate sodium (DSS) group, antibiotic + DSS group, Clostridium butyricum + DSS group and antibiotic+ Clostridium butyricum + DSS group, with 6 mice in each group. After the mice were pretreated with quadruple antibiotics (ampicillin 1 g/L, neomycin 1 g/L, metronidazole 1 g/L, and vancomycin 0.5 g/L) in normal drinking water for 30 d, the mice colitis model was induced with DSS. At the same time, the mice in Clostridium butyricum + DSS group and antibiotics+ Clostridium butyricum + DSS group were given 1×10 6colony-forming unit (CFU) Clostridium butyricum by gavage. The effect of Clostridium butyricum on mice with colitis was evaluated by disease activity index (DAI), colon length and histopathological score. The level of serum inflammatory factors was detected by enxyme linked immunosorbent assay, and the effect of Clostridium butyricum on gut microbita in mice was determined by fecal 16S rRNA sequencing. Results:The general condition of mice of the blank control group were good, and their DAI scores fluctuated around 0. Since the fourth day after DSS drinking water was given, the mice of the DSS group showed signs of colitis such as weight loss, unformed stools and bloody stools. On the fourth day after intervention, the DAI score of Clostridium butyricum + DSS group was lower than that of DSS group (0.000±0.000 vs. 0.444±0.111), and the difference was statistically significant ( t=4.000, P=0.016 1). On the tenth and twelfth day after the intervention, the DAI scores of antibiotic+ Clostridium butyricum + DSS group were both lower than those of antibiotic+ DSS group (0.000±0.000 vs. 1.111±0.222, 0.667±0.000 vs. 1.889±0.222), and the differences were statistically significant ( t=5.000 and 5.500, both P<0.05). The histopathological score of mice colon tissue of Clostridium butyricum + DSS group was lower than that of DSS group (2.50±1.73 vs. 5.50±1.00), and the histopathological score of mice colon tissue of antibiotic+ Clostridium butyricum+ DSS group was lower than that of antibiotic+ DSS group (1.25±0.96 vs. 5.00±0.82), and the differences were statistically significant ( t=3.000 and 5.960, both P<0.05). The serum level of interleukin (IL)-1β Clostridium butyricum+ DSS group was higher than that of blank control group ((4.464±0.075) ng/L vs. (3.907±0.080) ng/L), the serum levels of tumor necrosis factor-α, IL-6 and IL-1β of Clostridium butyricum+ DSS group and antibiotic+ Clostridium butyricum + DSS group were all lower than those of DSS group ((2.402±0.383) ng/L , (1.845±0.345) ng/L vs. (6.958±1.084) ng/L, (1.752±0.146) ng/L, (1.307±0.048) ng/L vs. (3.537±0.608) ng/L, (4.464±0.075) ng/L, (4.066±0.190) ng/L vs. (7.477±0.339) ng/L), and the differences were statistically significant ( t=5.005, 3.964, 4.495, 4.693, 6.294, 8.674 and 8.774 , all P<0.05). The results of 16S rRNA sequencing showed that there were a significantly large number of anti-inflammatory or short-chain fatty acid producing bacteria in the gut microbiota of mice intervened by Clostridium butyricum, among which the dominant bacteria genus in Clostridium butyricum + DSS group and antibiotic+ Colstridium butyicum+ DSS group were Mucispirillum (linear discriminant analysis (LDA)=3.667 log10, P=0.004) and Stenotrophomonas (LDA=2.778 log10, P=0.044). In the antibiotic+ Clostridium butyricum+ DSS group, the dominant bacteria genus were Peptococcus (LDA=2.685 log10, P=0.018), Butyricimonas (LDA=2.712 log10, P=0.011), Bilophila (LDA=3.204 log10, P=0.014), Intestinimonas (LDA=3.346 log10, P=0.010), Candidatus- Saccharimonas (LDA=3.363 log10, P=0.029), Desulfovibrio (LDA=3.402 log10, P=0.025), Oscillibacter (LDA=2.870 log10, P=0.019) and Akkermansia (LDA=4.031 log10, P=0.005). Conclusions:Clostridium butyricum can effectively improve colitis in mice and regulate the intestinal microbial structure of mice, whlie antibiotic pretreatment can strengthen its regulation of intestinal microbiota to and enhance the efficacy of Clostridium butyricum.

Objective:To determine the viral load of human herpesvirus 6 A (HHV-6A), HHV-6B and chromosomal integrated HHV-6 (ciHHV-6) simultaneously through a triple chip digital PCR (tcdPCR) method for detection of HHV-6A/6B and ribonuclease P-30 (RPP30).Methods:According to optimal reaction conditions of real-time fluorescence quantitative PCR (RT-qPCR) method, the tcdPCR mehod of HHV-6A, HHV-6B and RPP30 was established. The sensitivity of tcdPCR was determined by virus cultures and the specificity of tcdPCR was detected with other herpesviruses. Subsequently, the tcdPCR of HHV-6A, HHV-6B and RPP30 was verified through 127 whole blood samples.Results:The consistency between RT-qPCR and tcdPCR for HHV-6 detection was good (R 2>0.97). And there was no cross-reaction with other herpesviruses. The 14 positive samples could be detected effectively by the tcdPCR of HHV-6A, HHV-6B and RPP30. The lowest detectable viral load of HHV-6A and HHV-6B was 50 copies/ml and 105 copies/ml, respectively. And the ratio of HHV-6/(RPP30/2) in 14 positive samples was less than 1. Conclusions:The tcdPCR has good sensitivity and specificity. And HHV-6 tcdPCR method can quantitatively detect the viral load of HHV-6 infection and the copy number of RPP30, and ciHHV-6 can be judged by ratio of HHV-6/(RPP30/2) in clinical samples.