[Epidemiological characteristics and serum antibody detection of a COVID-19 aggregated outbreak in vaccinated population].

An epidemiological investigation was conducted on a cluster epidemic of COVID-19 in the vaccinated population in Beijing in 2022, and serum samples were collected from 21 infected cases and 61 close contacts (including 20 cases with positive nucleic acid in the isolation observation period). The results of antibody detection showed that the IgM antibody of two infected persons was positive, and the IgG antibody positive rates of patients who were converted, not converted to positive and infected persons were 36.84% (7/19), 63.41% (26/41) and 71.43% (15/21), respectively. About 98.78% of patients had been vaccinated with the SARS-CoV-2 inactivated vaccine. The positive rate of IgG antibody in patients immunized with three doses of vaccine was 86.00% (43/50), which was higher than that in patients with one or two doses [16.12% (5/31)]. The antibody level of M (Q1, Q3) in patients immunized with three doses was 4.255 (2.303, 7.0375), which was higher than that in patients with one or two doses [0.500 (0.500, 0.500)] (all P values<0.001). The antibody level of patients who were vaccinated less than three months [7.335 (1.909, 7.858)] was higher than that of patients vaccinated more than three months after the last vaccination [2.125 (0.500, 4.418)] (P=0.007). The positive rate and level of IgG antibody in patients who were converted to positive after three doses were 77.78% (7/9) and 4.207 (2.216, 7.099), respectively, which were higher than those in patients who were converted after one or two doses [0 and 0.500 (0.500, 0.500)] (all P values<0.05).

[Inhibition of GAS5 promoted invasion, migration and epithelial-mesenchymal transition of colorectal cancer cells via miR-21/PTEN/Akt axis].

Objective: To explore the effect of growth arrest-specific5 (GAS5) inhibition on the proliferation, colony formation, invasion, migration andepithelial-mesenchymal transition(EMT), cancer cell stem of HCT-116 and its mechanism. Methods: The colorectal carcinoma (CRC) cell HCT116 was divided into blank control, negative control (NC), si-GAS5 and si-GAS5+ miR-21 inhibitor groups. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to test the expressions of miR-21 and GAS5 at 48 h after transfection. The binding site of GAS5 and miR-21 was determined by luciferase reporter array. Cell proliferation ability was detected by CCK-8 assay. Cell colony ability was detected by colony formation assay. Cell invasion and migration abilities were detected by Transwell assay. Cell cycle and apoptosis were examined by flow cytometer (FCM). The protein levels of EMT associated factors including Snail, N-cadherin, vimentin, E-cadherin, stem cell related factors including CD44, SOX2, Oct2, and PTEN/Akt signal pathway associated factors were examined by western blotting. Results: The expression levels of miR-21 in blank, NC, si-GAS5 group were 1.00±0.10, 1.00±0.10, 1.80±0.20, the absorbance values were 0.51±0.02, 0.50±0.01 and 0.65±0.01, the cell clones were 90±4, 91±5, 200±8, the invaded cells were 118±3, 119±3, 150±4, the migrated cells were 110±2, 108±2, 127±2, the cell ratios in G(1) phase were (49.3±2.1)%, (50.1±2.0)% and (42.2±1.1)%, the cell ratios in S phase were (19.2±1.2)%, (20.2±1.1)% and (28.3±2.2)%, the cell apoptotic ratios were (14.4±2.2)%, (14.5±2.1)% and (7.2±1.3)%. These results indicated that inhibition of GAS5 up regulated the expression level of miR-21, promoted cell proliferation, invasion and migration, decreased G(1)-phase cells and increased S-phase cells, and suppressed cell apoptosis (P<0.05). Moreover, inhibition of GAS5 up regulated the expressions of Snail, N-cadherin, vimentin, Sox2, CD44, Oct2 and p-Akt in HCT-116 cells (P<0.05), while down regulated the expressions of E-cadherin and PTEN (P<0.05). Inhibition of miR-21 reversed the impact of GAS5 knockdown on PTEN/Akt signaling pathway (P<0.05). Conclusion: GAS5 can act as a competing endogenous RNA for miR-21, and down regulation of GAS5 can promote the development of CRC by activating the miR-21/PTEN/Akt signaling pathway and promoting the acquisition of EMT and tumor cell stemness.

Intrinsic Mechanism for Anisotropic Magnetoresistance and Experimental Confirmation in Co_{x}Fe_{1-x} Single-Crystal Films.

Using first-principles transport calculations, we predict that the anisotropic magnetoresistance (AMR) of single-crystal Co_{x}Fe_{1-x} alloys is strongly dependent on the current orientation and alloy concentration. An intrinsic mechanism for AMR is found to arise from the band crossing due to magnetization-dependent symmetry protection. These special k points can be shifted towards or away from the Fermi energy by varying the alloy composition and hence the exchange splitting, thus allowing AMR tunability. The prediction is confirmed by delicate transport measurements, which further reveal a reciprocal relationship of the longitudinal and transverse resistivities along different crystal axes.

[Endoscopic neurosurgery combined with intraventricular lavage for pyogenic ventriculitis].

Objective: To investigate the efficacy of endoscopic neurosurgery combined with intraventricular lavage for pyogenic ventriculitis. Methods: A retrospective analysis of 45 patients with pyogenic ventriculitis in six hospitals which included Beijing Shijitan Hospital and Peking Union Medical College Hospital from 2001 to 2017. Twenty-four patients (non-endoscopic group) were treated with external ventricular drainage combined with intraventricular antibiotics administration from 2001 to 2009. Twenty-one patients (endoscopic group) was treated by endoscopic neurosurgery combined with intraventricular antibiotics lavage from 2010 to 2017. The drainage time, mortality, and modified Rankin score (mRS) after 6 months of follow-up were compared between the two groups. Results: Drainage time: (20±6) days in the endoscopic group, and (42±10) days in the non-endoscopic group. There was a significant difference between the two groups (P<0.001). Days in hospital: (29±7) days in the endoscopic group, and (51±11) days in the non-endoscopic group. There were significant differences between the two groups (P<0.001). Mortality: 8 patients (33.3%) died in the non-endoscopy group, and 1 patient (4.76%) died in the endoscopy group. There was a significant difference between the two groups (P=0.017). After 6 months of follow-up, patients of mRS≤3 were 14 cases (66.67%) in the endoscopy group, and 7 cases (29.17%) in the non-endoscopic group. There was a significant difference between the two groups (P=0.001). Conclusion: Endoscopic neurosurgery combined with intraventricular antibiotics saline lavage for pyogenic ventriculitis is an effective assessment and treatment method, and it is worth further promotion and application.

[Analysis on infection sources and transmission chains of three outbreaks caused by 2019-nCoV Omicron variant in Beijing, China].

Objective: To investigate the infection sources and the transmission chains of three outbreaks caused by 2019-nCoV Omicron variant possibly spread through cross-border logistics in Beijing. Methods: Epidemiological investigation and big data were used to identify the exposure points of the cases. Close contacts were traced from the exposure points, and the cases' and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: The Omicron variant causing 3 outbreaks in Beijing from January to April, 2022 belonged to BA.1, BA.1.1 and BA.2. The outbreaks lasted for 8, 12 and 8 days respectively, and 6, 42 and 32 cases infected with 2019-nCoV were reported respectively. International mail might be the infection source for 1 outbreak, and imported clothes might be the infection sources for another 2 outbreaks. The interval between the shipment start time of the imported goods and the infection time of the index case was 3-4 days. The mean incubation period (Q1, Q3) was 3 (2,4) days and the mean serial interval (Q1, Q3) was 3 (2,4)days. Conclusions: The 3 outbreaks highlighted the risk of infection by Omicron variant from international logistics-related imported goods at normal temperature. Omicron variant has stronger transmissibility, indicating that rapid epidemiological investigation and strict management are needed.

[Survey of possible aerosol transmission of a COVID-19 epidemic caused by 2019-nCoV Delta variant].

Objective: To investigate the epidemiological characteristics and the transmission chain of a family clustering of COVID-19 cases caused by severe acute respiratory 2019-nCoV Delta variant in Changping district of Beijing. Methods: Epidemiological investigation was conducted and big data were used to reveal the exposure history of the cases. Close contacts were screened according to the investigation results, and human and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: On November 1, 2021, a total of 5 COVID-19 cases caused by 2019-nCoV Delta variant were reported in a family detected through active screening. The infection source was a person in the same designated isolation hotel where the first case of the family cluster was isolated from 22 to 27, October. The first case was possibly infected through aerosol particles in the ventilation duct system of the isolation hotel. After the isolation discharge on October 27, and the first case caused secondary infections of four family members while living together from October 27 to November 1, 2021. Conclusion: 2019-nCoV Delta variant is prone to cause family cluster, and close attention needs to be paid to virus transmission through ventilation duct system in isolation hotels.

[Survey on infection source of a cold-chain product associated COVID-19 epidemic caused by 2019-nCoV Delta variant in Beijing].

Objective: To investigate the source and the transmission chain of a cold-chain product associated COVID-19 epidemic caused by 2019-nCoV Delta variant in Beijing. Methods: Epidemiological investigation were used to verify the exposure points of the cases. Close contacts were traced from the exposure points, and human and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: A total of 112 cases of COVID-19 were reported in the epidemic from January 18 to February 6, 2022 in Beijing. Except for 1 case was uncertain, there were epidemiological links among 111 cases. The source of infection was the packages of imported cold-chain products from Southeast Asia, which were harvested and stored in a local cold-storage in January 2021, and packaged and sent to the cold-storage A in A district in June 2021, and then sold in batches in cold-storage B in B district from January 2022. The first case was infected in the handling of positive frozen products, and then 77 cases occurred due to working, eating and living together with the index case in the cold-storage B, cold-storage C and restaurant D. Besides the cold-storage B, C and the restaurant D, there were 16 sub-transmission chains, resulting in additional 35 cases. Conclusion: The epidemic indicated that the risk of 2019-nCoV infection from imported cold-chain products contaminated by package and highlighted the importance to strengthen the management of cold-chain industry in future.

EZH2-mediated H3K27me3 enrichment on the lncRNA MEG3 promoter regulates the growth and metastasis of glioma cells by regulating miR-21-3p.

OBJECTIVE: Glioma is one of the most common and invasive brain tumors worldwide. Long non-coding RNAs (LncRNAs) play an important role in the development of glioma. However, the regulatory mechanism of LncRNAs in glioma has not been fully elucidated. This study aimed to explore the interaction of lncRNA maternally expressed gene 3 (MEG3) and aberrant histone modification in glioma. MATERIALS AND METHODS: The expression levels of MEG3 and miR-21-3p in glioma cells were measured by quantitative polymerase chain reaction (qPCR). EZH2 (enhancer of zeste homolog 2) and H3K27me3 expression in glioma cells were detected by Western Blot (WB). The binding site of the promoter of MEG3 by H3K27me3 was confirmed by ChIP-Real-time PCR. The direct target of MEG3 and miR-21-3p in glioma cells was measured by a luciferase reporter assay. Cell proliferation was detected by Cell Counting Kit-8 (CCK8), and cell invasion and migration were measured by Transwell assays. RESULTS: EZH2 and miR-21-3p were upregulated and MEG3 was downregulated in glioma cells. Silencing of EZH2 inhibited cell proliferation, migration, and invasion in U87 and U251 cells. Meanwhile, the expression of H3K27me3 could be significantly inhibited by EZH2 interference. H3K27me3 protein can bind to MEG3 promoter directly. EZH2 inhibition and MEG3 down-expression in U87 cells reversed the effects of silencing of EZH2 on glioma cell growth and metastasis. However, EZH2 inhibition and MEG3 overexpression in U251 cells restricted cell proliferation, migration, and invasion. Furthermore, miR-21-3p was verified to interact with MEG3 by direct binding. Inhibition of MEG3 promoted U87 cell growth and metastasis, which was further strengthened following the co-transfection of si-MEG3 and miR-21-3p. Overexpressed MEG3 inhibited U251 cell growth and metastasis and a complete reversal of the results observed in the co-transfection of LV-MEG3 and miR-21-3p. CONCLUSIONS: EZH2 was highly expressed in glioma cells and EZH2-mediated H3K27me3 enrichment on the MEG3 promoter regulated the growth and metastasis of glioma cells by targeting miR-21-3p. It potentially provided a new therapeutic marker targeting glioma.

[Effects of Src on cervical cancer cells proliferation and apoptosis through ERK signal transduction pathway].

Objective: To explore the effect of Src on cervical cancer cells through ERK signal transduction pathway. Methods: Experimental study was carried out in vitro. Cervical cancer cell lines Hela (HPV-positive) and C33A (HPV-negative) were treated with Src kinase inhibitor PP2. Then, the cell cycle and apoptosis of each group were evaluated by using flow cytometry (FCM). Western blotting and Real-time PCR were used to detect the levels of the expression of ERK 1/2, c-Fos and c-Jun mRNA and protein respectively. The database was established and analyzed with SPSS statistical software (version 20.0). Results: After down-regulating Src, the cell proliferation was inhibited and cell apoptosis was induced. The proportions of G0/G1 stage of Hela and C33A cell in cell cycle increased while G2/M and S stages decreased. Meanwhile, the mRNA levels of ERK 1, ERK 2, c-Fos and c-Jun increased. And the expression levels of ERK 1/2, phosphorylated ERK 1/2 (p-ERK 1/2) and phosphorylated c-Fos (p-c-Fos) protein decreased, while c-Jun and phosphorylated c-Jun (p-c-Jun) protein expression increased. In addtion, the change level of Hela cell, p-ERK 1/2 and c-Fos protein were lower than that of C33A cell before and after the Src inhibition. Conclusions: Src, involved in regulating the expression of key factors of the ERK signal transduction pathway including p-ERK 1/2 and p-c-Fos, might be capable of promoting the proliferation of cervical cancer cells and inhibiting their apoptosis. The infection with HPV might have adjustable effect on this process.

[Interaction between polycyclic aromatic hydrocarbons and p16, FHIT gene CpG island methylation in patients with cervical intraepithelial neoplasias].

Objective: To explore the effect of polycyclic aromatic hydrocarbons (PAHs) and p16, FHIT gene CpG island methylation, as well as their interaction in cervical intraepithelial neoplasias. Methods: Objects of this study were from a cohort of cervical lesions study in Yangqu county of Shanxi province. All the patients were diagnosed pathologically, that including 83 patients with high-grade cervical intraepithelial neoplasia (CINⅡ/Ⅲ), 86 patients with low-grade cervical intraepithelial neoplasia (CINⅠ) and another 91 women under normal cervical (NC) condition. 1-hydroxy pyrene in the urine was detected by high performance liquid chromatography (HPLC) while CpG island methylation status of tumor suppressor gene p16 and FHIT were measured by methylation-specifc polymerase chain reaction (MSP). Data were analyzed with Kruskal-Wallis H test, chi-square test and trend of chi-square test. Logistic regression models were used to estimate the odds ratio (OR) and corresponding 95% confidence intervals (95%CI) between influencing factors and the cervical disease by using the SPSS statistical software (version 20.0). The interaction under study was evaluated by using the generalized multifactor dimensionality reduction (GMDR) model. Results: Level of 1-hydroxy pyrene (H=50.743, P<0.001) and the high exposure rate of 1-hydroxy pyrene (trend χ(2)=20.146, P<0.001) were gradually increasing along with the severity of cervical intraepithelial neoplasia. The CpG island methylation rates of p16, FHIT in CINⅠand CINⅡ/Ⅲ group were higher than that in NC group, and gradually increasing along with the severity of cervical intraepithelial neoplasia (trend χ(2)=9.75, P=0.002; trend χ(2)=10.39, P=0.001). Results from the GMDR model showed that interaction existed among the high exposure of 1-hydroxy pyrene and the CpG island methylation of p16, FHIT in CINⅠ and CINⅡ/Ⅲ group. Conclusion: Under the high exposure of 1-hydroxy pyrene and the CpG island methylation of p16, FHIT appeared to have increased the risk of cervical intraepithelial neoplasia and causing synergistic effect in cervical intraepithelial neoplasia.

[Effect of extracellular signal-regulated kinas 1/2 expression and HPV16 infection and their interaction in progression of cervical cancerization].

Objective: To investigate the effect of ERK1/2 protein expression and HPV16 infection, as well as their interaction in the cervical carcinogenesis. Methods: A total of 176 patients, including 34 cases with normal cervix (NC), 26 cases with cervical intraepithelial neoplasm Ⅰ (CIN Ⅰ), 57 cases with cervical intraepithelial neoplasm Ⅱ/Ⅲ (CIN Ⅱ/Ⅲ) and 59 cases with cervical squamous cell carcinoma (SCC), were enrolled from Shanxi Tumor Hospital, Shanxi Maternal and Child Health Center, Jincheng Coal General Hospital from September 2013 to March 2014. The information about their demographic characteristics and risk factors associated with cervical cancer was collected with structural questionnaire, and cervical tissue samples were collected from each subject. HPV16 infection was detected by PCR, and phosphorylation of ERK1/2 (p-ERK1/2) protein expression levels were detected by immunohistochemistry. Meanwhile, cervical cancer cell lines Siha (HPV16 positive) and C33A (HPV negative) were treated with ERK inhibitor U0126 in vitro. Cell proliferation was determined by living cell count, cell cycle and apoptosis was detected by flow cytometry. Results: The HPV16 infection rate (trend χ(2)=17.99, P<0.001) and p-ERK1/2 protein high expression (trend χ(2)=10.58, P=0.001) increased gradually along with the severity of cervix lesions. There was an additive interaction between HPV16 infection and p-ERK protein expression in the CIN Ⅰ, CIN Ⅱ/Ⅲ and SCC groups. Cell experiments showed that after ERK inhibition, the proliferation of the two cells were reduced (Siha: t=6.863, P<0.001; C33A: t=7.092, P<0.001) and the apoptosis were increased (Siha: t=-5.201, P=0.006; C33A: t=-4.335, P=0.005). After ERK inhibition, the cell proliferation index of Siha (HPV16 positive) was higher than that of C33A (HPV16 negative) (t =7.066, P<0.001), but the apoptosis rate of Siha was lower than that of C33A (t=-2.431, P=0.057). Conclusions: HPV16 infection and the high expression of p-ERK1/2 could increase the risk of cervical cancer. And there might be synergistic actions between the two factors in the progression of cervical cancer. The effect of ERK1/2 activation to HPV16 infection cells might be more significant in the process of cervical cancer cell proliferation and apoptosis.

[Effects of both folic acid, p16 protein expression and their interaction on progression of cervical cancerization].

Objective: To explore the effects of both folic acid, p16 protein expression and their interaction on progression of cervical cancerization. Methods: Participants were pathologically diagnosed new cases, including 80 women with normal cervical (NC), 55 patients with low-grade cervical intraepithelial neoplasia (CINⅠ), 55 patients with high-grade cervical intraepithelial neoplasia (CINⅡ/Ⅲ) and 64 patients with cervical squamous cell carcinoma (SCC). Serum folate levels were detected by microbiological assay method while p16 protein expression levels were measured by Western-blot. In vitro, cervical cancer cell lines C33A (HPV negative) and Caski (HPV16 positive) were treated with different concentrations of folate. Proliferation and apoptosis of cells and the levels of p16 protein expression were measured in groups with different folic acid concentrations. Results: Results showed that the levels of serum folate were (5.96±3.93) ng/ml, (5.08±3.43) ng/ml, (3.92±2.59) ng/ml and (3.18±2.71) ng/ml, and the levels of p16 protein were 0.80±0.32, 1.33±0.52, 1.91±0.77, and 2.09±0.72 in the group of NC, CINⅠ, CINⅡ/Ⅲ and SCC, respectively. However, the levels of serum folate decreased (trend χ2=32.71, P<0.001) and p16 protein expression increased (trend χ2=56.06, P<0.001) gradually along with the severity of cervix lesions. An additive interaction was seen between serum folate deficiency and high expression of p16 protein in the CINⅠ, CINⅡ/Ⅲ and SCC group. Results in vitro showed that, with the increase of folate concentration, the inhibition rate of cell proliferation (C33A: r=0.928, P=0.003; Caski: r=0.962, P=0.001) and the rate on cell apoptosis (C33A: r=0.984, P<0.001; Caski: r=0.986, P<0.001) all increased but the levels of p16 protein expression (C33A: r=-0.817, P=0.025; Caski: r=-0.871, P=0.011) reduced. The proliferation inhibition rate (C33A: r=-0.935, P=0.002; Caski: r=-0.963, P=0.001) and apoptosis rate of cells (C33A: r=-0.844, P=0.017; Caski: r=-0.898, P=0.006) were negatively correlated with the levels of p16 protein expression. Conclusions: Our findings indicated that both serum folate deficiency and high expression of p16 protein could increase the risk of cervical cancer and cervix precancerous lesion, and there was an additive interaction between them. Our findings suggested that folic acid supplementation could reverse the abnormal expression of p16 protein, and effectively promote apoptosis and inhibit proliferation in cervical carcinoma cells.

Magnetic transcranial motor and somatosensory evoked potentials in cervical spondylitic myelopathy.

Fourteen cervical spondylitic myelopathy (CSM) patients were clinically diagnosed and proved by MRI and surgery. The results of 11 patients showed that 8 (72.7%) had motor evoked potential (MEP) abnormality with prolongation of central motor conduction time (CMCT) in 7, and absence of motor action potentials after C7 stimulation in one. Five of the 11 patients showed normal somatosensory evoked potentials (SEPs) along the same arm. The short term (2-4 weeks) follow-up study in 10 patients showed normalization of the prolonged CMCT in one and reappearance of MEPs with C7 stimulation in another. Non-invasive and painless magnetic transcranial stimulation of the motor pathways is useful in the assessment and management of CSM patients, and is better than electrical stimulation.

Activities of serum enzymes in patients with viral hepatitis B, posthepatitic cirrhosis and hepatocellular carcinoma.

Using spectrophotometric method, we studied the activities of serum alpha-L-fucosidase, N-acetyl-beta-D-glucosaminidase and alpha-D-mannosidase in 94 patients, of whom 32 had acute hepatitis, 4 subacute fulminant hepatitis, 27 chronic active hepatitis, 22 posthepatitic cirrhosis and 9 hepatocellular carcinoma. In comparison with normal controls, the activities of the three glycosidases in the patients were significantly increased. The degree of the elevation of alpha-L-fucosidase activity correlated to the clinical phases and the course of acute infection of hepatitis B virus (HBV). The levels of glycosidase activities could reflect to a certain degree the pathological variations of the liver. Monitoring the levels of glycosidase activities, especially alpha-L-fucosidase, would be helpful in the diagnosis and medical care of viral hepatitis and hepatocellular carcinoma.

[Magnetic resonance imaging of pituitary hyperplasia in a child with growth arrest and primary hypothyroidism].

We report a case of pituitary hyperplasia in a child presented with significant growth arrest and laboratory evidence of hypothyroidism. Magnetic resonance imaging (MRI) revealed symmetrical pituitary enlargement seemed to be macroadenoma. After thyroid hormone replacement therapy, the child's height increased and pituitary enlargement regressed. Awareness of MRI appearance of pituitary hyperplasia in children with laboratory evidence of hypothyoidism might avoid misdiagnosis for pituitary tumor, which may also manifest as growth disorder, obviating unnecessary surgery.