Distribution and drug resistance profiles of pathogens causing bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia / 中国当代儿科杂志

OBJECTIVES@#To study the changes in the distribution and drug resistance profiles of pathogens causing bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia.@*METHODS@#The medical data were collected from the children with acute lymphoblastic leukemia who were admitted to the First Affiliated Hospital of Zhengzhou University between January 2015 and December 2020 and developed bloodstream infection after chemotherapy. The samples were divided into the first three years group and the next three years group according to the time of testing to investigate the differences in the distribution and drug resistance profiles of pathogens as time.@*RESULTS@#A total of 235 strains of pathogens were isolated, among which there were 159 Gram-negative strains (67.7%; mainly Escherichia coli and Klebsiella pneumoniae), 61 Gram-positive strains (26.0%; mainly Staphylococcus epidermidis), and 15 strains of fungi (6.4%; mainly Candida albicans). There were no significant differences between the first three years group and the next three years group in the detection rate of Gram-negative bacteria (68.8% vs 66.9%, P>0.05) or Gram-positive bacteria (29.2% vs 23.7%, P>0.05). Compared with the first three years group, the next three years group had significant increases in the detection rate of Streptococcus mitis (5.8% vs 0.0%, P<0.05) and fungi (9.4% vs 2.1%, P<0.05). There was no significant difference in the drug resistance rate of Gram-negative or Gram-positive bacteria between the two groups (P>0.05).@*CONCLUSIONS@#Enterobacteriaceae bacteria are the main pathogens of bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia, while the detection rates of Streptococcus mitis and fungi tend to increase as time, which needs to be taken seriously in clinical practice.

Serum antibody levels in COVID-19 patients six months after hospital discharge / 上海预防医学

ObjectiveTo investigate the level of serum antibodies in COVID-19 patients six months after discharge， and to provide data to evaluate the duration of IgM， IgG and neutralizing antibody titers in the patients. MethodsEnzyme-linked immunosorbent assay （ELISA） was used to determine the antibody levels of IgM and IgG， and the new coronavirus live virus neutralization test was used to detect the neutralizing antibodies in the plasma of 181 recovered patients. ResultsThe IgG positive rate was 92.27% （167/181） in COVID-19 patients six months after discharge， while the lgM positive rate was 28.18% （51/181）. Six months after hospital discharge， 117 recovered patients （64.64%） were positive for IgG antibodies and negative for IgM antibodies， indicating that they had produced stable antibodies. This result suggested that they had been infected with the new coronavirus （SARS-CoV-2） and were in the recovery stage. The positive detection rate of neutralizing antibodies was as high as 91.71%. ConclusionSix months after infection with SARS-CoV-2， IgG antibodies produced in the patients continue to exist， and the neutralizing antibodies maintain a high and stable level. Results of this study have important guiding significance for future research on the durability of new coronavirus antibodies.

Serum antibody levels in COVID-19 patients six months after hospital discharge / 上海预防医学

ObjectiveTo investigate the level of serum antibodies in COVID-19 patients six months after discharge， and to provide data to evaluate the duration of IgM， IgG and neutralizing antibody titers in the patients. MethodsEnzyme-linked immunosorbent assay （ELISA） was used to determine the antibody levels of IgM and IgG， and the new coronavirus live virus neutralization test was used to detect the neutralizing antibodies in the plasma of 181 recovered patients. ResultsThe IgG positive rate was 92.27% （167/181） in COVID-19 patients six months after discharge， while the lgM positive rate was 28.18% （51/181）. Six months after hospital discharge， 117 recovered patients （64.64%） were positive for IgG antibodies and negative for IgM antibodies， indicating that they had produced stable antibodies. This result suggested that they had been infected with the new coronavirus （SARS-CoV-2） and were in the recovery stage. The positive detection rate of neutralizing antibodies was as high as 91.71%. ConclusionSix months after infection with SARS-CoV-2， IgG antibodies produced in the patients continue to exist， and the neutralizing antibodies maintain a high and stable level. Results of this study have important guiding significance for future research on the durability of new coronavirus antibodies.

Construction of a drug screening model for miscarriage from induced pluripotent stem cells in vitro / 药学学报

Drug use during pregnancy is unavoidable. Therefore, it is vitally important for medical workers to help pregnant women take drugs correctly to reduce the incidence of spontaneous abortion, premature birth, and low birth weight. In our study, drug screening model with induced pluripotent stem cells (iPSCs) was used to find some improper drugs which will result in woman's abortion. With 3D culture in vitro, iPSCs can form embryoid bodies (EBs) and cerebral organoids, which simulated in vitro development of early embryos, from inner cell mass to germ-layer differentiation. In the experiment, EBs were exposed to mifepristone (RU486), and three experimental groups were divided randomly. They were control group (without RU486), low-dose group (L-RU486, 10 μg·mL-1), and high-dose group (H-RU486, 20 μg·mL-1). After mifepristone exposure, EBs were observed at days 5, 8, and 11, including size of EB, cell apoptosis, and differentiation of germ layers, by using inverted optical microscope, TUNEL assay, and immunofluorescent staining. The results showed that through 3D culture, iPSCs could develop into embryoid bodies, neural rosettes, and finally cerebral organoids. After mifepristone exposure, EBs' sizes were decreased (P < 0.01); the levels of cell apoptosis in EBs were increased after mifepristone exposure (P < 0.01); the development of EBs' germ layer was affected. Mifepristone exposure could inhibit the proliferation of embryonic stem cells, reduce the differentiation of ectoderm (P < 0.01) and promote the development of mesoderm (P < 0.05). In conclusion, iPSCs can be used as a screening model for abortion drug, and EBs’ diameter, cell apoptosis, and differentiation changes of the germ layers can serve as criteria of abortion drug screening.

Professor 's clinical experience in treatment of infertility of ovulation disturbance with acupuncture-moxibustion therapy / 中国针灸

The characteristics of syndrome differentiation and the experience of professor were briefly introduced for the treatment of infertility of ovulation disturbance, including three aspects, named the thought of diagnosis and treatment, the therapeutic method and the acupoint prescription, as well as the clinical case report. Academically, professor is deeply influenced by professor , the acupuncture master of Xin'an school and Lingnan school. Regarding the treatment of gynecological diseases, the academic thought of professor - and - is contributed. Professor attaches the importance to the syndrome differentiation based on meridian and collateral, supplemented by the syndrome differentiation of , , and blood, cold and heat, as well as the deficiency and excess. In clinical treatment, the acupoints are selected specially from the conception vessel, the governor vessel, the thoroughfare vessel and the belt vessel. The extra meridians are equally important as the regular ones in the treatment, especially the belt vessel. Additionally, the treatment focuses on communicating the congenital with the acquired one, regulating the liver and benefiting the kidney, as well as adjusting the heart, the spleen and the stomach to ease the uterus. Simultaneously, the great consideration is paid to the menstruation regulation so as to promote pregnancy.

Microenvironments induce iPSCs and BMSCs into neuron-like cells--Reelin's regulative role in cell differentiation and polarization / 生理学报

The present study was aimed to investigate how the induced pluripotent stem cells (iPSCs) and bone marrow mesenchymal stem cells (BMSCs) differentiate into neuron-like cells under the induction of hippocampal microenvironments and Reelin's regulation. iPSCs or BMSCs were co-cultured with WT (wild type) or genotypic hippocampal slice and cerebral homogenate supernatant, then the stem cells' differentiation under the induction of hippocampal environment was observed by using immunofluorescence technique. In the meantime, stem cells were co-cultured with hippocampal slice and cerebral conditioned medium of reeler (Reelin deletion) mouse respectively. The results showed that both adhesive iPSCs and BMSCs on WT hippocampal slice exhibited lamination of double "C" shape with high density on granular and pyramidal layers. The stem cells could differentiate into neuron-like cells with obvious polarization on WT hippocampal slice. In pyramidal cell layer, the differentiated neuron-like cells were oriented vertically with similar shapes of pyramidal cell in vivo, and the cells within molecule layer were arranged horizontally. In addition, adhesive iPSCs and BMSCs could differentiate into Nestin positive neural stem cells and NeuN positive neurons, respectively, under WT hippocampal microenvironment. On the other hand, under induction of hippocampal microenvironment of reeler mouse, iPSCs and BMSCs differentiation could also be seen, but their lamination was in disorder, and cell polarization was irregular. Moreover, differentiation and polarization of the iPSCs and BMSCs were delayed. These results suggest both iPSCs and BMSCs can differentiate into neuron-like cells under the induction of hippocampal microenvironments. Reelin is involved in the regulation of neuronal differentiation and cell polarization. Without Reelin, the cellular lamination and polarization appear irregular, and the stem cells' differentiation is delayed.

Inhibitory effect of exogenous insulin-like growth factor binding protein 7 on proliferation of human breast cancer cell line MDA-MB-453 and its mechanism / 生理学报

The present study was to investigate the effects of exogenous insulin-like growth factor binding protein 7 (IGFBP7) on the proliferation of human breast cancer cell line MDA-MB-453 and its possible mechanism. By means of MTT method in vitro, the results showed exogenous IGFBP7 inhibited the growth of MDA-MB-453 cells (IC50 of IGFBP7 = 8.49 μg/mL) in time- and concentration-dependent manner. SB203580, p38(MAPK) inhibitor, blocked the anti-proliferative effect of exogenous IGFBP7. The flow cytometry assay showed that exogenous IGFBP7 remarkably induced G0/G1 arrest in MDA-MB-453 cells. The Western blot showed that exogenous IGFBP7 promoted phosphorylation of p38(MAPK), up-regulated expression of p21(CIP1/WAF1), and inhibited phosphorylation of Rb. SB203580 restrained exogenous IGFBP7-induced regulation of p21(CIP1/WAF1) and p-Rb in MDA-MB-453 cells. In conclusion, the present study suggests that exogenous IGFBP7 could activate the p38(MAPK) signaling pathway, upregulate p21(CIP1/WAF1) expression, inhibit phosphorylation of Rb, and finally induce G0/G1 arrest in MDA-MB-453 cells.

Effects of Choukroun's platelet-rich fibrin on human gingival fibroblasts proliferation, migration and type I collagen secretion / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of platelet-rich fibrin (PRF) on human gingival fibroblasts (HGF) biological behavior such as proliferation, migration and collagen-I expression.</p><p><b>METHODS</b>Human healthy gingival tissues were cultured according to the explant technique to obtain primary cultures. PRF was prepared by means of Choukroun's. HGF were co-cultured with PRF membrane originating from the same donor as the explants, divided into three groups, PRF1 group, PRF2 group and blank control group. Methyl thiazolyl tetrazolium (MTT) assay was used for cytotoxicity and cell proliferation study, and enzyme-linked immunosorbent assay (ELISA) for collagen-I (COL-I) secretion study at the 1st, 3rd, 5th day respectively. Eluates from PRF membrane was prepared, and divided into three groups, PRF1 group, PRF2 group and blank control group. Transwell chamber was utilized to determine the effect of PRF membrane eluate on cell migration.</p><p><b>RESULTS</b>The A values of HGF in culture of the PRF1 (0.615 ± 0.036, 0.686 ± 0.006, 0.693 ± 0.004) and PRF2 groups (0.653 ± 0.023, 0.766 ± 0.034, 0.775 ± 0.053) were significantly higher than those of the control cultures (0.514 ± 0.020, 0.544 ± 0.006, 0.545 ± 0.009) (P < 0.01), but the difference between PRF1 and PRF2 group was not significant (P > 0.05). In each group at different time points, the HGF proliferation effect was significantly enhanced with time (P < 0.01). Cell migration test showed that the migration numbers of HGF in PRF1 and PRF2 groups (85.67 ± 2.94, 85.83 ± 1.47) were significantly higher than those of the control group (54.17 ± 2.48) (P < 0.01), but the difference between the two experimental groups was not significant (P > 0.05). COL-I secretion test exhibited that the A values of COL-I in PRF1 (0.184 ± 0.004, 0.200 ± 0.004, 0.204 ± 0.009) and PRF2 group (0.213 ± 0.008, 0.226 ± 0.005, 0.229 ± 0.006) were significantly higher than the A values of the control group (0.174 ± 0.002, 0.184 ± 0.002, 0.186 ± 0.003) (P < 0.01), but the difference between the two experimental groups was not significant (P > 0.05). In each group, the secretion level of COL-I increased significantly with time (P < 0.01).</p><p><b>CONCLUSIONS</b>PRF could exert a positive effect on HGF biological behaviour and had clinical application potential in the treatment of gingival recession and in the periodontal tissue engineering when combined with seed cell HGF.</p>