Characterization of a pangolin SARS-CoV-2-related virus isolate that uses the human ACE2 receptor.

Various SARS-CoV-2-related coronaviruses have been increasingly identified in pangolins, showing a potential threat to humans. Here we report the infectivity and pathogenicity of the SARS-CoV-2-related virus, PCoV-GX/P2V, which was isolated from a Malayan pangolin (Manis javanica). PCoV-GX/P2V could grow in human hepatoma, colorectal adenocarcinoma cells, and human primary nasal epithelial cells. It replicated more efficiently in cells expressing human angiotensin-converting enzyme 2 (hACE2) as SARS-CoV-2 did. After intranasal inoculation to the hACE2-transgenic mice, PCoV-GX/P2V not only replicated in nasal turbinate and lungs, but also caused interstitial pneumonia, characterized by infiltration of mixed inflammatory cells and multifocal alveolar hemorrhage. Existing population immunity established by SARS-CoV-2 infection and vaccination may not protect people from PCoV-GX/P2V infection. These findings further verify the hACE2 utility of PCoV-GX/P2V by in vivo experiments using authentic viruses and highlight the importance for intensive surveillance to prevent possible cross-species transmission.

Isolation and characterization of a pangolin-borne HKU4-related coronavirus that potentially infects human-DPP4-transgenic mice.

We recently detected a HKU4-related coronavirus in subgenus Merbecovirus (named pangolin-CoV-HKU4-P251T) from a Malayan pangolin1. Here we report isolation and characterization of pangolin-CoV-HKU4-P251T, the genome sequence of which is closest to that of a coronavirus from the greater bamboo bat (Tylonycteris robustula) in Yunnan Province, China, with a 94.3% nucleotide identity. Pangolin-CoV-HKU4-P251T is able to infect human cell lines, and replicates more efficiently in cells that express human-dipeptidyl-peptidase-4 (hDPP4)-expressing and pangolin-DPP4-expressing cells than in bat-DPP4-expressing cells. After intranasal inoculation with pangolin-CoV-HKU4-P251, hDPP4-transgenic female mice are likely infected, showing persistent viral RNA copy numbers in the lungs. Progressive interstitial pneumonia developed in the infected mice, characterized by the accumulation of macrophages, and increase of antiviral cytokines, proinflammatory cytokines, and chemokines in lung tissues. These findings suggest that the pangolin-borne HKU4-related coronavirus has a potential for emerging as a human pathogen by using hDPP4.

Snack consumption of children and adolescents in China and its correlation with overweight and obesity / 中国学校卫生

Objective@#To understand the current situation of snack consumption among children and adolescents in China and its relationship with overweight and obesity, so as to provide a basis for formulating strategies of preventing and controlling overweight and obesity in children and adolescents in China.@*Methods@#A total of 1 882 children and adolescents aged 6-17 years old, choosed from 15 provinces, autonomous regions and municipalities according to China Health and Nutrition Survey in 2018, were selected. Snack consumption was investigated by the 24 hour dietary retrospective method for three consecutive days. The pattern of snack consumption was explored by cluster analysis, and the relationship between snack consumption and overweight and obesity was analyzed by Logistic regression.@*Results@#The snack consumption rate was 60.6%, and the percentage of daily energy intake from snacks was 2.4%. Snack consumption characteristics could be divided into four modes. Mode 1 was characterized by daily intake of medium amount of fruit, Mode 2 was characterized by daily intake of small amount of fruit and baked goods, Mode 3 was characterized by daily intake of small amount of fruit, and Mode 4 was characterized by daily intake of medium amount of milk and small amount of fruit. After adjusting the relevant covariates such as energy intake, compared with those who did not eat snacks, the OR (95% CI ) values of the risk of overweight and obesity in different snack consumption patterns were 1.56(0.93- 2.58 ), 0.81( 0.51- 1.24), 1.24(0.94-1.63) and 1.00(0.60-1.63), respectively; the OR (95% CI ) values of percentage of daily energy intake from snacks from low to high quartiles were 1.17(0.81-1.68), 1.32(0.92-1.89), 1.12(0.77-1.61) and 1.00(0.69-1.45), respectively. There was no statistically significant difference( P >0.05).@*Conclusion@#The proportion of Chinese children and adolescents consuming snacks is relatively high, mainly including fruit and its products, milk and its products and baked goods. No association between snack consumption and overweight and obesity has been found.

Long-term stability and protection efficacy of the RBD-targeting COVID-19 mRNA vaccine in nonhuman primates.

Messenger RNA (mRNA) vaccine technology has shown its power in preventing the ongoing COVID-19 pandemic. Two mRNA vaccines targeting the full-length S protein of SARS-CoV-2 have been authorized for emergency use. Recently, we have developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor-binding domain (RBD) of SARS-CoV-2 (termed ARCoV), which confers complete protection in mouse model. Herein, we further characterized the protection efficacy of ARCoV in nonhuman primates and the long-term stability under normal refrigerator temperature. Intramuscular immunization of two doses of ARCoV elicited robust neutralizing antibodies as well as cellular response against SARS-CoV-2 in cynomolgus macaques. More importantly, ARCoV vaccination in macaques significantly protected animals from acute lung lesions caused by SARS-CoV-2, and viral replication in lungs and secretion in nasal swabs were completely cleared in all animals immunized with low or high doses of ARCoV. No evidence of antibody-dependent enhancement of infection was observed throughout the study. Finally, extensive stability assays showed that ARCoV can be stored at 2-8 °C for at least 6 months without decrease of immunogenicity. All these promising results strongly support the ongoing clinical trial.

Migratory wild birds carrying multidrug-resistant Escherichia coli as potential transmitters of antimicrobial resistance in China.

Migratory birds play an important role in the spread of multidrug-resistant (MDR) bacteria. To investigate the prevalence of MDR Escherichia coli in migratory birds in China and potential relationships with the environment, a total of 1387 samples (fecal samples, cloacal swabs, or throat swabs) were collected from migratory birds from three different river basins in China. The collected samples were processed and subjected to bacteriological examinations. Antimicrobial susceptibility testing of the recovered isolates was performed using the E-test for the detection of minimum inhibitory concentrations (MICs). Some antibiotic resistance genes were detected and the PCR products were confirmed by sequencing. In total, 478 (34.7%) E. coli isolates were recovered. The results showed that the drug-resistant E. coli isolates were highly resistant to ß-lactams (43.7%) and tetracycline (22.6%), and 73 (15.3%) were MDR, including eight that were extended spectrum ß-lactamase-positive. The retrieved strains harbored the blaCTX-M, blaTEM-1, tet(A), tet(B), tet(M), sul1, sul2, sul3, cmlA, floR, and intI1 genes with a prevalence of 5.9%, 36.4%, 80.5%, 11.9%, 6.8%, 6.8%, 47.5%, 12.7%, 50.8%, 37.3%, and 61.0%, respectively. The drug resistance rate of the isolates from southern China was higher than those from northern China. The E. coli samples collected for migratory birds in the Pearl River Basin had the highest proportion (46.7%) MDR isolates. Furthermore, MDR bacteria carried by migratory birds were closely related to the antibiotic content in the basin, which confirms that MDR bacteria carried by migratory birds are likely acquired from the environment. This study also confirmed that migratory birds are potential transmitters of MDR bacteria, demonstrating the need to reduce the use and emission of antibiotics and further in-depth studies on the mechanisms underlying drug resistance of bacteria.

The Presence of Blastocystis in Tibetan Antelope (Pantholops hodgsonii).

Blastocystis is a protozoan that parasitizes the intestines. A number of hosts of Blastocystis have been found, including human and animals. However, there has been no research on the prevalence of Blastocystis in Tibetan antelope. Here, a molecular test was performed using 627 Tibetan antelope fecal samples collected on Tibet in China from 2019 to 2020. The result showed that 30 (4.8%) samples were Blastocystis positive. The highest prevalence of Blastocystis was in Shuanghu County (25/209, 12.0%), followed by Shenza County (2/103, 1.9%), Nyima County (3/182, 1.6%), and Baigoin County (0/133, 0.0%). In addition, logistic regression analysis showed that the gender, sampling year, and area of Tibetan antelope were risk factors for Blastocystis prevalence. Three subtypes (ST10, ST13, and ST14) of Blastocystis were found in Tibetan antelope through a subtype sequence analysis, and ST13 was identified to be the dominant subtype. This is the first investigation for the infection of Blastocystis in Tibetan antelope. Collectively, the data in this study have expanded the host range of Blastocystis and provided basic information for the distribution of Blastocystis subtypes, which could support the prevention of Blastocystis infection in wild animals.

Cloning and expression analysis of protein kinase C gene from Whitmania pigra / 中国中药杂志

Protein kinase C(PKC) is a type of protein kinase widely involved in cell proliferation and development, but the developmental mechanism in the gonads of androgynous animals is still unclear. In order to explore the role of protein kinase C in the development of Whitmania pigra germ cells, the Wh. pigra PKC(Wp-PKC) gene was cloned, bioinformatics analysis was conducted, and fluorescent quantitative PCR was used to analyze the expression of female and male gonads. The results showed that:(1)The cloned Wp-PKC had a full length of 2 580 bp, a relative molecular weight of 76 555.19, and contains an open reading frame encoding 670 amino acids, Wp-PKC was closely related to Danio rerio PKC-α and rat PKC-γ. The similarity of amino acid sequence was 55% and 58%.(2)The protein encoded by Wp-PKC had no signal peptide and was a hydrophilic protein. The secondary structure is mainly composed of random coils, α-helices, extended chains, folds and folds, with the largest proportion of random coils and α-helices. Wp-PKC protein does not contain a transmembrane domain. Multiple sequence alignment and domain prediction analysis show that Wp-PKC contains 4 conserved domains of classical protein kinase C.(3)Fluorescence quantitative results showed that the expression of Wp-PKC in Wh. pigra gonads was positively correlated with the development of germ cells, and the expression in male gonads was significantly higher than that in female gonads. In summary, Wp-PKC is a classic PKC, and Wp-PKC may promote the development of Wh. pigra, especially the development of male gonads, and provide references for further research on the developmental mechanisms of Wh. pigra.

Hamilton-Thorne Integrated Visual Optical System Ⅰ (IVOSⅠ) versus IVOS Ⅱ for human sperm analysis / 中华男科学杂志

Objective@#To compare the computer-assisted sperm analysis (CASA) systems Hamilton-Thorne Integrated Visual Optical System Ⅰ (IVOSⅠ) and IVOS Ⅱ after verifying the performance of the latter so as to ensure the accuracy of the results of analysis.@*METHODS@#Based on the criteria established in the 5th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen (WHO 5th Ed), we compared the main semen parameters obtained from IVOSⅠ with those generated by IVOS Ⅱ, and examined the consistency between the results of the two sperm analyzers.@*RESULTS@#The linear relationship of the outlier test, bias estimation and scatter plot and the results of the outlier test of the two systems all met the requirements of comparison analysis and showed an obvious correlativity. The application scope of the results obtained from the apparatus indicated a reasonable value range, with r = 0.988 for sperm concentration, r = 0.975 for sperm progressive motility (PR), and r = 0.981 for total sperm motility. Evaluation of the acceptability of the predicted bias showed that the allowable total error (TEa) to be 6.67% with sperm concentration at 12 × 106 /ml and 2.34% with PR < 31%, their upper limit of the allowable error < 1/2. The results of IVOS Ⅱ conformed to the requirements of the WHO 5th Ed.@*CONCLUSIONS@#The main parameters derived from IVOSⅠ and IVOS Ⅱ are comparable and consistent, indicating that both can be used for the examination of semen samples.

Serological survey of avian influenza virus infection in non-avian wildlife in Xinjiang, China.

We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China.

Mechanisms of resveratrol bovine serum albumin nanoparticle-induced cell death in human ovarian cancer SKOV3 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of resveratrol bovine serum albumin nanoparticles on SKOV3 cell line and its mechanisms.</p><p><b>METHODS</b>The morphological changes of the cells exposed to the nanoparticles were observed by apoptotic body/cell nucleus DNA staining under inverted microscope and fluorescence microscope, and the pathway of cell death was determined by phosphatidylserine translocation. Western blotting was performed to detect the activation of cyto.c, caspase-3 and caspase-9.</p><p><b>RESULTS</b>DNA ladder was detected with gel electrophoresis and the cell death was partially inhibited by the pan-caspase inhibitor Z-VAD-FMK. Gel electrophoresis displayed both DNA ladder and smear in RES-BSANP exposed groups, while DNA ladder disappeared in Z-VAD-FMK group and only the smear was left. Cyto.c in the cytoplasm was released at 2 h, while the expression of caspase-9 protein reached the peak level at 4 h and caspase-3 expression was obvious enhanced at 8 h. At 4 h, caspase-9 expression in the cells exposed to 100 µmol/L RES-BSANP was decreased significantly as compared to the cells treated with 50 µmol/L RES-BSANP (P>0.05).</p><p><b>CONCLUSION</b>RES-BSANP can induce the necrosis and apoptosis of SKOV3 cells via either caspase-dependent or caspase-independent pathways.</p>