Dynamic and reversible DNA methylation changes induced by genome separation and merger of polyploid wheat

Background

Wheat is a powerful genetic model for studying polyploid evolution and crop domestication. Hexaploid bread wheat was formed by two rounds of interspecific hybridization and polyploidization, processes which are often accompanied by genetic and epigenetic changes, including DNA methylation. However, the extent and effect of such changes during wheat evolution, particularly from tetraploid-to-hexaploid wheat, are currently elusive.

Results

Here we report genome-wide DNA methylation landscapes in extracted tetraploid wheat (ETW, AABB), natural hexaploid wheat (NHW, AABBDD), resynthesized hexaploid wheat (RHW, AABBDD), natural tetraploid wheat (NTW, AABB), and diploid (DD). In the endosperm, levels of DNA methylation, especially in CHG (H=A, T, or C) context, were dramatically decreased in the ETW relative to natural hexaploid wheat; hypo-differentially methylated regions (DMRs) (850,832) were 24-fold more than hyper-DMRs (35,111). Interestingly, those demethylated regions in ETW were remethylated in the resynthesized hexaploid wheat after the addition of the D genome. In ETW, hypo-DMRs correlated with gene expression, and TEs were demethylated and activated, which could be silenced in the hexaploid wheat. In NHW, groups of TEs were dispersed in genic regions of three subgenomes, which may regulate the expression of TE-associated genes. Further, hypo-DMRs in ETW were associated with reduced H3K9me2 levels and increased expression of histone variant genes, suggesting concerted epigenetic changes after separation from the hexaploid.

Conclusion

Genome merger and separation provoke dynamic and reversible changes in chromatin and DNA methylation. These changes correlate with altered gene expression and TE activity, which may provide insights into polyploid genome and wheat evolution.

[Epidemiological characteristics of imported COVID-19 cases in Guangzhou]

Objective: To understand the epidemiological characteristics of imported COVID-19 cases in Guangzhou and provide scientific basis for the prevention and control of the disease. Methods: The data of imported COVID-19 in Guangzhou reported as of April 1, 2020 were collected from National Notifiable Disease Report System of China. The software Excel 2010 and SPSS 19.0 were applied for data cleaning and statistical analysis. Results: As of April 1, 2020, a total of 103 imported COVID-19 cases had been reported in Guangzhou, in which 92 were confirmed cases and 11 were asymptomatic infection cases. The number of the confirmed imported cases accounted for 11.4% (92/806) in of the total in China at the same time. The male to female ratio of the cases was 1.58∶1 (63∶40). The median age of the cases was 31 years (P(25)-P(75):22-40 years), range of age was 11-63 years. The main occupational distributions of the cases were business services (41/103, 39.8%) and students (36/103, 35.0%). The imported cases whose destinations were 19 provinces and municipalities rather than Guangdong after entering the country accounted for 43.7%. The main source countries of infections were the United Kingdom (27/103, 26.2%), the Philippines (13/103, 12.6%), the United States (13/103, 12.6%) and Nigeria (7/103, 6.8%). There were 34 inbound flights from which the imported COVID-19 cases were detected, in which 10 flights (10/34, 29.4%) were found to carry more than 3 cases, with an average voyage time of (11.14±0.53) hours. A total of 29 imported cases(28.2%) showed symptoms before entering the country, and 65 cases (63.1%) had been isolated before the onset of the disease. The mean free activity time of the isolated cases after the onset was (6.76±0.79) days. The average number of the imported cases' close contacts was 53. There were 13 clusters of COVID-19 caused by the imported cases, involving 36 cases (including 1 imported associated case). Conclusions: The sources of the imported COVID-19 cases in Guangzhou were widely distributed, and no cases had been found to be infected on the flights. In the early stage of the imported epidemic, there was high risk for the spread of the epidemic. Strengthened prevention and control of imported COVID-19 effectively reduced the of transmission risk of COVID-19 in communities.

[Risk prevention of plague and suggestions for coping in China]

Plague is listed by the WHO as one of 20 infectious diseases that have re-emerged. Plague was prevalent in the world, bringing great disaster to the people around the world. Nowadays, great achievements have been made in the prevention and control of plague in our country. Human plague in China is currently sporadic, but there are still risks of resurgence spread and importation. This paper reviews the incidence of human plague globally and in China in the past ten years, summarizes the characteristics of current plague epidemic globally and in China, analyzes the current risks of plague prevention in China, and puts forward relevant countermeasures.

MicroRNA-579-3p promotes the progression of osteoporosis by inhibiting osteogenic differentiation of mesenchymal stem cells through regulating Sirt1

OBJECTIVE

To explore whether microRNA-579-3P was involved in the development of osteoporosis, and to investigate the possible molecular mechanisms.

PATIENTS AND METHODS

The messenger RNA (mRNA) expression levels of microRNA-579-3P, alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2) and bone sialoprotein (BSP) in serum samples of osteoporosis patients and normal controls were detected by quantitative Real-time polymerase chain reaction (qRT-PCR), respectively. Meanwhile, the expressions of the above genes during osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs) were examined as well. To investigate the effect of microRNA-579-3P on osteogenesis, microRNA-579-3P was overexpressed and knocked down in hMSCs. Subsequently, the mRNA and protein expression levels of osteogenesis-related genes, such as ALP, RUNX2 and BSP, were detected by qRT-PCR and Western blot, respectively. In addition, ALP activity and mineralization forming ability were evaluated by ALP staining and alizarin red staining. Bioinformatics predicted that Sirt1 was the target gene of microRNA-579-3P. Subsequent luciferase reporter gene assay was performed to verify the binding relationship of microRNA-579-3P to Sirt1. Meanwhile, qRT-PCR and Western blot were used to detect the changes in the mRNA and protein expression levels of Sirt1, respectively. After overexpression of microRNA-579-3P and Sirt1, qRT-PCR, Western blot, ALP staining and alizarin red staining assays were performed to detect the osteogenic differentiation of hMSCs.

RESULTS

The expression of microRNA-579-3P in serum of patients with osteoporosis was significantly higher than that of normal controls. Meanwhile, the expression of microRNA-579-3P decreased gradually during osteogenic differentiation of hMSCs. Overexpression of microRNA-579-3P significantly reduced the expressions of osteogenic related genes, including ALP, RUNX2 and BSP. Besides, ALP activity and mineralized nodule formation ability decreased obviously as well. Luciferase reporter gene assay showed that microRNA-579-3P could bind to Sirt1. After overexpression of microRNA-579-3P, the mRNA and protein expression levels of Sirt1 were significantly reduced, which were reversed after silence of microRNA-579-3P. Simultaneous overexpression of microRNA-579-3P and Sirt1 could reverse the inhibition of osteogenic differentiation of hMSCs caused by overexpression of microRNA-579-3P alone.

CONCLUSIONS

MicroRNA-579-3P could inhibit osteogenic differentiation of hMSCs by regulating Sirt1, thereby promoting the development of osteoporosis.

[Comparison of epidemic characteristics between severe acute respiratory syndrome and coronavirus disease 2019]

Objective: To compare epidemic characteristics between severe acute respiratory syndrome (SARS) and coronavirus disease 2019 (COVID-19). Methods: The general information, including epidemiological and clinical data of the confirmed cases during the epidemic period of the two infectious diseases was collected. The data of SARS in Guangzhou was derived from the technical files of Guangzhou Center for Disease Control and Prevention (GZCDC), including the statistical report and brief report of the epidemic situation (from January 2 to May 11, 2003);The data of COVID-19 in Wuhan was derived from the epidemic data published by Wuhan health and Health Committee's official website and other publicly reported documents (from December 9, 2019 to March 11, 2020). Descriptive analysis was used for a comparativeanalysis of the time and age characteristics, the number of cases, basic reproduction number (R0), proportion of medical staff in confirmed cases (%), crude mortality, etc. Results: A total of 1 072 cases of SARS in Guangzhou were included in the study. The incidence ratio of male to female was 1∶1.26. 43 cases of death were reported with a mortality rate of 4.01%. The median age was 36 years old. The proportion of medical staff in the early stage of the epidemic was 29.04% (88 cases). As to COVID-19 in Wuhan, a total of 49 978 cases were included, The incidence ratio of male to female was 1.04∶1. The 2 423 cases of death were reported with a mortality rate of 4.85%. The median age was 56 years old. The proportion of medical staff in the early stage of the epidemic was 30.43% (42 cases). Conclusion: The COVID-19 in Wuhan has the characteristics of high incidence and wide population. However, the epidemic situation is falling rapidly, and the prevention and control strategy needs to be adjusted timely. The prevention and control of nosocomial infection should be addressed in future.

[Analysis of clinicopathological features of clear cell tumor of the lung]

Objective: To analyze the clinicopathological features of clear cell tumor of the lung (CCTL). Methods: A total of 9 cases were collected from August 2008 to August 2019 in the Department of Pathology of the First Medical Center of PLA General Hospital and Hainan Hospital of PLA General Hospital. Their clinical data, pathological characteristics, immunohistochemical staining and special staining results were summarized and analyzed. Results: There were 3 males and 6 females, aged from 28 to 70 years (average 52.2 years). All tumors were located in the peripheral part of the lung, and were solitary in 8 cases, and multiple (24 nodules) in 1 case. The lesion was round or oval, with clear boundary. The diameter of the nodule was 0.5-5.5 cm. Histologically, the tumor cells were oval, short fusiform or polygonal, with obvious nucleoli. The tumor cells were mostly distributed in sheet around thin-walled vessels, and there was hyaline degeneration around the blood vessels. Neither necrosis nor mitosis could be seen. Immunohistochemical staining showed tumor cells were diffusely positive for Vimentin, and CD34, Melan-A, specific monoclonal antibody against melanoma (HMB45) and S-100 were positive with different degrees. Broad spectrum cytokeratin (CK), epithelial membrane antigen (EMA), smooth muscle actin (SMA), desmin, CD10, paired box gene 8 (PAX-8) or myomodulatory protein (Myo-D1) were all negative. The positive index of the proliferating cell nuclear antigen (Ki-67) was low. Schiff dyeing with periodate (PAS) staining was positive, PAS staining of glycogen digested by amylase (d-PAS) staining was negative. All the tumors in the nine cases were resected and patients were followed up for 5-137 months. Except 1 case was lost for follow-up, the other 8 cases survived without recurrence or metastasis of the disease. Conclusions: CCTL is a rare benign tumor, most of which are single, few of which can be multiple; histopathological characteristics and immunohistochemical staining are helpful for diagnosis and differentiated diagnosis. After complete resection, the prognosis was good. However, when histological features indicating malignancy, intense follow-up should be considered.

Predicting pungency and understanding the pungency mechanism of capsaicinoids using TOPS-MODE approach

Quantitative structure-property relationship (QSPR) models were developed for predicting the pungency of a set of capsaicinoids. Multiple linear regression (MLR) coupled with topological substructural molecular descriptor (TOPS-MODE) approach was used. The best MLR model based on only five orthogonalized TOPS-MODE variables allowed us to obtain a coefficient of determination of 0.954 on the training set. The predictive power of the model was validated through a test set and several external validation parameters. This showed that the TOPS-MODE descriptors weighted by bond dipole moments, van der Waals atomic radii, and the total solute hydrogen bond basicity affected pungency. The contributions of certain bonds and fragments to pungency were used to understand the pungency mechanism of capsaicinoids. The selected model can more accurately predict pungency of capsaicinoids compared than those found in the literature, and especially bring insights into the structural features and chemical factors related to pungency.

[Comparison of islet autoantigen-specific T cell response detected by direct enzyme-linked immunospot (ELISPOT) assay and accelerated co-cultured dendritic cells (acDCs) assay]

Objective: To investigate the effect of enzyme-linked immunospot (ELISPOT) on accelerated co-cultured dendritic cells (acDCs) and direct detection of islet full-length antigen-specific T cell response in peripheral blood of patients with type 1 diabetes mellitus (T1DM). Methods: Sixteen patients with T1DM[9 males, 7 females, mean age(28.5±9.4)years] and 12 age-and sex-matched healthy controls were selected in the Department of Metabolism and Endocrinology, the Second Xiangya Hospital between March 2012 and August 2014. The numbers of IFN-γ secreting CD4(+)T cells responding to glutamic acid decarboxylase 65 (GAD(65)), C-peptide (CP) and insulin (INS) were detected by ELISPOT-acDCs and ELISPOT-direct assays, respectively. The positive rate of islet autoantigen and associated antigen reactive T cells under different detection assays were compared. Results: The positive rate for GAD(65), INS, and CP antigen reactive T cells detected by ELISPOT-acDCs was 1/16, 6/16 and 4/16, respectively, and T cells positive for INS in T1DM patients were higher than that in the controls (0/12) (P=0.024). Combining GAD(65), CP and INS-ELISPOT-acDCs detection, the positive rate for CD4(+) T cells in T1DM patients was higher than that in the controls (9/16 vs 1/12, P=0.016). The positive rate for GAD(65), INS, and CP antigen reactive T cells detected by ELISPOT-direct detection was 2/16, 1/16 and 7/16, respectively, and T cells positive for CP was higher than that in the controls (1/12), but the difference was not statistically significant (P=0.088). Likewise, the positive rate for CD4(+) T cells was higher in T1DM patients than that in the controls by combined GAD(65), CP and INS-ELISPOT-direct detection (8/16 vs 1/12, P=0.039). Compared with the ELISPOT-direct assay, the positive rate of INS antigen specific T cell response detected by ELISPOT-acDCs was higher (P=0.041). No statistical differences of other antigens were found between the two groups (all P>0.05). Conclusions: Both multiple islet antigens-combined CD4(+)-ELISPOT-acDCs and direct assays could provide diagnostic value of cellular immunology for T1DM patients. The ELISPOT-acDCs assay is superior to the ELISPOT-direct assay in the detection of INS antigen-specific T cell response.

LncRNA MALAT1 expression inhibition suppresses tongue squamous cell carcinoma proliferation, migration and invasion by inactivating PI3K/Akt pathway and downregulating MMP-9 expression

OBJECTIVE

LncRNA MALAT1 has been proved to be involved in the development of various types of human cancers while the involvement of MALAT1 in tongue squamous cell carcinoma has not been reported. In view of this, our study aimed to investigate the functionality of MALAT1 in tongue squamous cell carcinoma.

PATIENTS AND METHODS

The expression of MALAT1 in tumor tissues and adjacent healthy tissues of tongue cancer patients, and the serum from tongue cancer patients as well as healthy controls, were detected by quantitative Real Time-PCR (qRT-PCR). ROC curve analysis was performed to analyze the diagnostic value of plasma MALAT1 for tongue cancer. Survival curves were plotted using the Kaplan-Meier method to evaluate the prognostic value of plasma MALAT1 for tongue cancer. CCK-8 assay, transwell migration and invasion assay were performed to investigate the effects of MALAT1 knockdown on the proliferation, migration and invasion of tongue cancer cells, respectively. The effects of MALAT1 overexpression on the PI3K/Akt pathway and MMP-9 expression were detected by Western blot.

RESULTS

The expression level of MALAT1 was remarkably higher in tumor tissues than that in adjacent healthy tissues. Serum MALAT1 was significantly higher in tongue cancer patients than in healthy controls. MALAT1 knockdown markedly inhibits the proliferation, migration and invasion of tongue cancer cells. MALAT1 knockdown also reduced the phosphorylation level of Akt as well as the expression level of MMP-9. It showed no significant effects on Akt expression, while PI3K activator treatment reduced the inhibitory effects of MALAT1 knockdown on the proliferation, migration and invasion of tongue cancer cells.

CONCLUSIONS

LncRNA MALAT1 expression inhibition can inhibit the proliferation, migration and invasion of tongue cancer cells by inactivating the PI3K/Akt pathway and downregulating MMP-9. MALAT1 may serve as a target for the treatment of tongue squamous cell carcinoma.

ZNF295-AS1 inhibits autophagy via the ZNF295-AS1/miR-508-5p/ATG7 axis in AS

OBJECTIVE

As a result of gene-environment interactions, the incidence of atherosclerosis (AS) is rapidly increasing worldwide. Autophagy in endothelial cells is a key process of AS and is difficult to control when it becomes excessive in the end stage of AS.

MATERIALS AND METHODS

In this study, we found increased expression levels of ZNF295-AS1 in the serum of AS patients, as well as in ox-LDL-treated HUVECs. The autophagy level was also upregulated in both samples. We demonstrated that ZNF295-AS1 may interact directly with miR-508-5p to act as a miR-508-5p sponge. The negative relationship between ZNF295-AS1 and miR-508-5p indicated that ZNF295-AS1 may be an upstream suppressor of miR-508-5p.

RESULTS

ATG7 plays a critical role in autophagy and was predicted to be a target of miR-508-5p. Therefore, we overexpressed miR-508-5p, which reduced the expression level of ATG7, enhanced cell proliferation and prevented autophagy. These data indicated that the ZNF295-AS1/miR-508-5p/ATG7 axis may participate in autophagy regulation in ox-LDL-treated HUVECs. The subsequent rescue experiments revealed the specificity of the ZNF295-AS1/miR-508-5p/ATG7 axis in the contribution of ZNF295-AS1 to autophagy.

CONCLUSIONS

Overall, our findings demonstrate a novel mechanism by which ZNF295-AS1 silencing regulates ATG7 reduction and inhibits autophagy, which may delay the progression of AS. The ZNF295-AS1/miR-508-5p/ATG7 axis may be of therapeutic significance in AS.

FRI0261 DIFFERENTIAL EXPRESSION OF PERIPHERAL CD4+ T CELLS IN PATIENTS WITH SYSTEMIC SCLEROSIS AND MIXED CONNECTIVE TISSUE DISEASE

Background:

The CD4+T cell subsets plays an important role in its pathogenesis, and its new research are constantly being published, but its specific changes between SSc and MCTD are still unclear.

Objectives:

The aim of the present study was to explore the absolute numbers of CD4+T subsets in peripheral blood(PB) of patients with SSc and MCTD using our modified flow cryometric method and investigate the role in the pathogenesis of both.

Methods:

The PB samples from 54 patients with SSc, 51 patients with MCTD as well as 30 healthy control subjects were analyzed for lymphocyte subsets using flow cytometry. Of these patients, 19 had pulmonary involvement, including 9 patients with SSc and 10 patients with MCTD. Using directly the percentages from flow cytometry combined with internal standard beads calculated absolute number of peripheral lymphocyte subsets from the subjects in each group.

Results:

Although there were some changes among CD4+T cell subsets in PB from these SSc patients and MCTD patients, the major alteration was the reductions of Treg cells. Compared with the normal controls, the absolute number of CD4+CD25+FOXP3+Treg cells were significantly decreased in SSc patients and MCTD patients, and the absolute number of Th1 cells in MCTD patients is also significantly reduced. Notably, the absolute numbers of Th17 and Th2 cells were not different from those of normal controls, but the ratios of Th17/Treg in SSc patients and MCTD patients were significantly higher, causing by insufficient number of Treg cells (Fig 1). In addition, in patients with pulmonary involvement, we found that the absolute number of Treg cells was significantly reduced in patients with MCTD, while the absolute number of Th2 cells and Th17 cells was significantly reduced in patients with SSc(Fig 2).

Fig 1.

Comparison of the levels of CD4+T lymphocyte subsets in SSc patients, MCTD patients and healthy controls: (A) The absolute number of peripheral Th1 cells in patients with MCTD was significantly reduced; (B and C) There was no significant difference in the absolute number of Th2 cells in peripheral blood of different subjects; (D and E) The ratio of Th17/Treg cells in PB of patients with SSc and MCTD were significantly higher.*P< 0.05; **P< 0.01; ***P< 0.001.

Conclusion:

The number of peripheral Treg cells in patients with SSc and MCTD was significantly reduced, suggesting that that SSc and MCTD progression is associated with the imbalances between pro-inflammation cells to anti-inflammation Treg cells. In addition, we also found that the decrease in peripheral numbers of Treg cells may contribute to the development of MCTD-associated lung disease, whereas in SSc patients who had lung involvement, the reduce in peripheral number of Th17 cells may result in a severe imbalance of Th17/Treg cells, thereby promoting disease progression.

Fig 2.

Comparison of the levels of CD4+T lymphocyte subsets in patients who had pulmonary involvement and healthy controls: (A) There was no significant difference in the absolute number of Th1 cells in peripheral blood of different subjects; (B and C) The absolute number of peripheral Th2 cells and Th17 cells in patients with SSc were significantly reduced; (D and E) The ratio of Th17/Treg cells in PB of patients with MCTD were higher.*P< 0.05; **P< 0.01; ***P< 0.001.

References:

[1]Liu M, Wu W, Sun X, et al. New insights into CD4(+) T cell abnormalities in systemic sclerosis. Cytokine Growth Factor Rev. 2016 Apr; 28:31-6. doi: 10.1016/j.cytogfr.2015.12.002.

Acknowledgments:

None

Disclosure of Interests:

None declared

[Comparison of epidemic characteristics between SARS in 2003 and COVID-19 in 2020 in Guangzhou]

Objective: By analyzing the epidemic characteristics and related indicators of SARS and COVID-19, to explore the reasons for the similarities and differences of the two epidemics, so as to provide reference for epidemic prevention and control. Methods: The general situation, clinical classification, activity history, contact history, family members' contact and incidence of the two infectious diseases in Guangzhou were collected and used to analyze the time characteristics, occupational characteristics, age characteristics and other key indicators of the two diseases, including the number of cases, composition ratio (%), mean, median, crude mortality, etc. Results: A total of 1 072 cases of SARS were included in the study. Three hundred and fifty three were severe cases with the incidence of 30.13%. Forty three cases of death were reported with a mortality rate of 4.01%. The average age was 46 years old, and 26.31% of the cases were medical staff. The interval time between first report to continuous zero reports was 129 days. As to COVID-19, a total of 346 cases were included. 58 of which were severe cases with the incidence of 16.67%. One case of death was reported with a mortality rate of 0.29%. The average age was 38 years old, and no hospital infection among medical staff was reported. The interval time between first report to continuous zero reports was 35 days. Conclusions: The prevention and control strategies for COVID-19 were more effective compared to that of SARS, and the emergency response procedures were worth to be evaluated and summarized.

Rapid and visual detection of 2019 novel coronavirus (SARS-CoV-2) by a reverse transcription loop-mediated isothermal amplification assay

OBJECTIVE

To evaluate a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and compare it with RT-PCR.

METHODS

We designed primers specific to the orf1ab and S genes of SARS-CoV-2. Total viral RNA was extracted using the QIAamp Viral RNA Mini Kit. We optimized the RT-LAMP assay, and evaluated it for its sensitivity and specificity of detection using real-time turbidity monitoring and visual observation.

RESULTS

The primer sets orf1ab-4 and S-123 amplified the genes in the shortest times, the mean (±SD) times were 18 ± 1.32 min and 20 ± 1.80 min, respectively, and 63°C was the optimum reaction temperature. The sensitivities were 2 × 10¹ copies and 2 × 10² copies per reaction with primer sets orf1ab-4 and S-123, respectively. This assay showed no cross-reactivity with 60 other respiratory pathogens. To describe the availability of this method in clinical diagnosis, we collected 130 specimens from patients with clinically suspected SARS-CoV-2 infection. Among them, 58 were confirmed to be positive and 72 were negative by RT-LAMP. The sensitivity was 100% (95% CI 92.3%-100%), specificity 100% (95% CI 93.7%-100%). This assay detected SARS-CoV-2 in a mean (±SD) time of 26.28 ± 4.48 min and the results can be identified with visual observation.

CONCLUSION

These results demonstrate that we developed a rapid, simple, specific and sensitive RT-LAMP assay for SARS-CoV-2 detection among clinical samples. It will be a powerful tool for SARS-CoV-2 identification, and for monitoring suspected patients, close contacts and high-risk groups.

Current research and prevention of aflatoxins in China

Since their discovery in the 1960s, aflatoxins were found to have a considerable impact on the health of humans and animals as well as the country’s economy and international trade. Aflatoxins are often found in nuts, cereals and animal feeds, which has a significant danger to the food industry. Over the years, several steps have been undertaken worldwide to minimise their contamination in crops and their exposure to humans and animals. China is one of the largest exporters and importers of food and animal feed. As a result, many studies have been carried out in China related to aflatoxins, including their distribution, pollution, detection methods, monitoring, testing and managing. Chinese scientists studied aflatoxins in microbiological, toxicological, ecological effects as well as policies relating to their controlling. China has thus put into practice a number of strategies aiming at the prevention and control of aflatoxins in order to protect consumers and ensure a safe trade of food and feed, and the status and enlargement of these strategies are very important and useful for many consumers and stakeholders in China. Therefore, this article aims at the detriment assessments, regulations, distribution, detection methods, prevention and control of aflatoxins in China. It equally provides useful information about the recent safety management systems in place to fight the contamination of aflatoxins in food and feed in China.

Influence of the Klotho/FGF23/Egr1 signaling pathway on calcium-phosphorus metabolism in diabetic nephropathy and the intervention of Shenyuan granules

This study aimed to explore the effects of Shenyuan granules on the Klotho/FGFR23/Egr1 signaling pathway and calcium-phosphorus metabolism in diabetic mice models with impairment of renal function. Streptozotocin-induced diabetic nephropathy (DN) mice models were randomly divided into three groups: Shenyuan granules group (n=10), model control group (n=10), and blank control group (n=10). Corresponding drugs were given by gavage for 8 weeks. Blood glucose and serum creatinine (SCr), urea nitrogen (BUN), calcium (Ca), phosphorus (P) and mLAB were detected before and after administration. Moreover, RT-qPCR was performed to detect the expression of CYP24 and CYP27 mRNA in kidney tissue. Blood FGF23 was detected by ELISA. Western-blot and immunohistochemistry were performed to detect the expressions of Klotho, FGFR1, Egr1, CYP24, CYP27, ERK1/2 and p-ERK1/2. Compared with the blank control group, in the model control group serum FGF23,P, SCr and 24-hour proteinuria levels increased (P<0.05), serum Ca significantly decreased (P<0.05), expressionss of Egr1, CYP24, CYP27 and p-ERK1/2 were up-regulated (P<0.05), and the expressions of Klotho and FGFR1 were down-regulated (P<0.05). After treatment, compared with the model control group, in the Shenyuan granule group serum FGF23, P, SCr levels decreased (P<0.05), serum Ca increased (P<0.05), expressions of Egr-1, CYP24, CYP27 and p-ERK1/2 were down-regulated (P<0.05), and the expressions of Klotho and FGFR1 were up-regulated (P<0.05). Shenyuan granules may partly intervene in the expressions of CYP24 and CYP27 through the Klotho/FGF23/Egr1 signaling pathway, thereby improving calcium and phosphorus metabolism and alleviating renal injury in diabetic nephropathy.

The association between gestational diabetes mellitus and cancer in women: A systematic review and meta-analysis of observational studies

AIM

Both type 1 and type 2 diabetes are associated with greater risk of a variety of cancers. However, the association between gestational diabetes mellitus (GDM) and risk of cancer has so far not been well addressed. This study aimed to summarize the epidemiological evidence of the association between GDM and subsequent risk of cancer.

METHODS

PubMed and Embase databases were searched for relevant studies, and a random-effects model was used to calculate the summary relative risks (RRs) along with the corresponding 95% confidence intervals (CIs).

RESULTS

A total of 17 observational studies were selected, comprising 7 case-control and 10 cohort studies. Pooled effect estimates retrieved from these 17 studies showed that GDM was associated with an increased risk of breast cancer in Asia (pooled RR: 1.31, 95% CI: 1.01-1.70), but not in other regions, and also with thyroid cancer (RR: 1.28, 95% CI: 1.16-1.42), stomach cancer (RR: 1.43, 95% CI: 1.02-2.00) and liver cancer (RR: 1.27, 95% CI: 1.03-1.55). However, GDM was not associated with any increased risk of colon (RR: 1.41, 95% CI: 0.90-2.21), colorectal (RR: 1.16, 95% CI: 0.95-1.41), ovarian (RR: 1.14, 95% CI: 0.90-1.44), cervical (RR: 1.02, 95% CI: 0.81-1.29), pancreatic (RR: 3.49, 95% CI: 0.80-15.23), brain and nervous system (RR: 1.26, 95% CI: 0.80-1.97), blood (leukaemia, RR: 0.77, 95% CI: 0.45-1.30), endometrial (RR: 0.77, 95% CI: 0.20-2.98), skin (RR: 1.13, 95% CI: 0.81-1.59) or urological (RR: 0.98, 95% CI: 0.73-1.31) cancers.

CONCLUSION

GDM is associated with a greater risk of cancer in women, including breast, thyroid, stomach and liver cancers. However, further investigation is nonetheless warranted.

[Retracted: Clinical and epidemiological characteristics of 34 children with 2019 novel coronavirus infection in Shenzhen]

Objective: To describe the characteristics of clinical manifestations and epidemiology of children with 2019 novel coronavirus (2019-nCoV) infection. Methods: All 34 children with laboratory-confirmed 2019-nCoV infection by quantitative real-time reverse transcription-PCR through nasopharyngeal swab specimens were admitted to the Third People's Hospital of Shenzhen from January 19 to Febuary 7, 2020. Clinical data and epidemiological history of these patients were retrospectively collected and analyzed. Results: Among the 34 cases, 14 were males, and 20 were females. The median age was 8 years and 11 months. No patients had underlying diseases. There were 28 children (82%) related with a family cluster outbreak. There were 26 children (76%) with a travel or residence history in Hubei Province. These patients could be categorized into different clinical types, including 22 (65%) common cases, 9 (26%) mild cases and 3 (8.8%) asymptomatic cases. No severe or critical cases were identified. The most common symptoms were fever (17 cases, 50%) and cough (13 cases, 38% ). In the 34 cases, the white blood cell counts of 28 cases (82%) were normal. Five cases had white blood cell counts more than 10×10(9)/L. One case had white blood cell counts less than 4×10(9)/L. Neutropenia and lymphopenia was found in one case, respectively. C-reactive protein levels and erythrocyte sedimentation rates were elevated in 1 and 5 case, respectively. Elevated procalcitonin was found in 1 case and D-Dimer in 3 cases. The levels of lactic dehydrogenase (LDH) were more than 400 U/L in 10 cases. The CT images of these patients showed bilateral multiple patchy or nodular ground-glass opacities and/or infiltrating shadows in middle and outer zone of the lung or under the pleura. Twenty patients were treated with lopinavir and ritonavir. Glucocorticoids and immunoglobulin were not used in any cases. All the cases improved and were discharged from hospital. Further following up was need. Conclusions: The clinical manifestations in children with 2019-nCoV infection are non-specific and are milder than that in adults. Chest CT scanning is heplful for early diagnosis. Children's infection is mainly caused by family cluster outbreak and imported cases. Family daily prevention is the main way to prevent 2019-nCoV infection.

[Retracted: Clinical and epidemiological characteristics of 34 children with 2019 novel coronavirus infection in Shenzhen]

Objective: To describe the characteristics of clinical manifestations and epidemiology of children with 2019 novel coronavirus (2019-nCoV) infection. Methods: All 34 children with laboratory-confirmed 2019-nCoV infection by quantitative real-time reverse transcription-PCR through nasopharyngeal swab specimens were admitted to the Third People's Hospital of Shenzhen from January 19 to Febuary 7, 2020. Clinical data and epidemiological history of these patients were retrospectively collected and analyzed. Results: Among the 34 cases, 14 were males, and 20 were females. The median age was 8 years and 11 months. No patients had underlying diseases. There were 28 children (82%) related with a family cluster outbreak. There were 26 children (76%) with a travel or residence history in Hubei Province. These patients could be categorized into different clinical types, including 22 (65%) common cases, 9 (26%) mild cases and 3 (8.8%) asymptomatic cases. No severe or critical cases were identified. The most common symptoms were fever (17 cases, 50%) and cough (13 cases, 38% ). In the 34 cases, the white blood cell counts of 28 cases (82%) were normal. Five cases had white blood cell counts more than 10×10(9)/L. One case had white blood cell counts less than 4×10(9)/L. Neutropenia and lymphopenia was found in one case, respectively. C-reactive protein levels and erythrocyte sedimentation rates were elevated in 1 and 5 case, respectively. Elevated procalcitonin was found in 1 case and D-Dimer in 3 cases. The levels of lactic dehydrogenase (LDH) were more than 400 U/L in 10 cases. The CT images of these patients showed bilateral multiple patchy or nodular ground-glass opacities and/or infiltrating shadows in middle and outer zone of the lung or under the pleura. Twenty patients were treated with lopinavir and ritonavir. Glucocorticoids and immunoglobulin were not used in any cases. All the cases improved and were discharged from hospital. Further following up was need. Conclusions: The clinical manifestations in children with 2019-nCoV infection are non-specific and are milder than that in adults. Chest CT scanning is heplful for early diagnosis. Children's infection is mainly caused by family cluster outbreak and imported cases. Family daily prevention is the main way to prevent 2019-nCoV infection.

[Feasibility of echocardiography-guided repeated intraventricular blood sampling in mice]

Objective: To investigate the feasibility of echocardiography-guided closed-chest repeated intraventricular blood sampling in mice, and to clarify the maximum blood volume that can be collected by this method, and whether the method can be used for long-term repeated blood collection in mice. Methods: Twenty-four male C57BL/6J mice (10-14 weeks old) were divided into the terminal experiment group (n=4, for investigating the maximum blood amount that could be sampled at one time), the repeated 0.5 ml blood collection group (n=10, sampling 0.5 ml whole blood each time, once every two days for consecutive 4 weeks), and the repeated 0.75 ml blood collection group (n=10, sampling 0.75 ml whole blood each time, once every two days for consecutive 4 weeks). High-frequency echocardiography was used to display the largest section of the left ventricle, guiding the insulin syringe needle through the thorax into the left ventricle for blood collection. In the repeated 0.5 ml blood collection group, echocardiography was used to detect the cardiac structure and function before blood collection, three minutes after blood collection, and one week after the last (the 14th) blood collection. Results: We successfully performed echocardiography-guided closed-chest intraventricular blood sampling, with an average operating time (88±19)s per mouse, and a maximum blood volume (1.43±0.11)ml per mouse. In the repeated 0.5 ml blood collection group, heart rate, left ventricular ejection fraction, left ventricular fractional shortening, left ventricular end-diastolic dimension and left ventricular posterior wall end-diastolic thickness remained uncganged before the first blood collection and after 4 weeks of repeated blood collection (all P>0.05). No death in the repeated 0.5 ml blood collection group. However, in the 0.75 ml blood collection group, two mice died before the end point. Conclusions: The echocardiography-guided closed-chest intraventricular blood sampling is a safe, minimally invasive, convenient and efficient method, and can be used repeatedly for long-term blood collection in mice.