Epidemiological,Clinical and Serological Characteristics of Children with Coronavirus Disease 2019 in Wuhan: A Single-centered,Retrospective Study

In December 2019, SARS-CoV-2 was first detected in the samples obtained from three adult patients who suffered from an unknown viral pneumonia in Wuhan (Li et al. 2020). This unknown viral pneumonia is further named as coronavirus disease 2019 (COVID-19) by the World Health Organization. To date, the number of new COVID-19 cases has continued to skyrocket and the impact of SARS-CoV-2 on humans is far greater than any pathogen of this century in both breadth and depth. Previous studies have shown that adults with COVID-19 have symptoms of fever, dry cough, dyspnea, fatigue and lymphocytopenia. Moreover, COVID-19 is more likely to cause death in the elderly, especially those with chronic comorbidities (Huang et al. 2020). In Wuhan, more than 50, 000 COVID-19 cases have been confirmed, including over 780 pediatric patients, and only one child death case (Lu et al. 2020). Although the number of children cases was far fewer than that of adults, COVID-19 might endanger children's health and the information on children remains limited, especially in serological study. In the retrospective study, the investigators analyzed the epidemiological, clinical and serological characteristics of children with COVID-19 in Wuhan in the early stages of the outbreak, which might provide theoretical and practical help in controlling COVID-19 and similar emerging infectious diseases in the future.     

Prognostic significance of X-linked inhibitor of apoptosis protein in solid tumors: A systematic review and meta-analysis

X-linked inhibitor of apoptosis protein (XIAP) is aberrantly expressed in solid tumors. Considering conflicting data, we conducted this meta-analysis to investigate its prognostic role. Electronic databases were searched to collect studies about associations between XIAP expressions and survival outcomes. Hazard ratio (HR), odds ratio (OR), and 95% confidence interval (CI) were utilized as effect size estimates. A total of 3,794 patients from 21 published studies were included. The results revealed that high XIAP expressions correlated with age (OR = 2.02; 95% CI, 1.07–3.84), lymph node metastasis (OR = 1.69; 95% CI, 1.02–2.77), histological grade (OR = 2.04; 95% CI, 1.01–4.11), and tumor stage (OR = 2.18; 95% CI, 1.20–3.96). The combined HR revealed that high XIAP expressions associated with poor overall survival (OS) (HR = 1.60; 95% CI, 1.22–2.10). Our study suggested high XIAP expressions may be indicative of poor prognosis in solid tumors.     

Activation of gibberellin 2-oxidase 6 decreases active gibberellin levels and creates a dominant semi-dwarf phenotype in rice （Oryza sativa L.）

Gibberellin (GA) 2-oxidase plays a key role in the GA catabolic pathway through 2β-hydroxylation.In the present study,we isolated a CaMV 35S-enhancer activation tagged mutant,H032.This mutant exhibited a dominant dwarf and GA-deficient phenotype,with a final stature that was less than half of its wild-type counterpart.The endogenous bioactive GAs are markedly decreased in the H032 mutant,and application of bioactive GAs (GA3 or GA4) can reverse the dwarf phenotype.The integrated T-DNA was detected 12.8 kb upstream of the OsGA2ox6 in the H032 genome by TAIL-PCR.An increased level of OsGA2ox6 mRNA was detected at a high level in the H032 mutant,which might be due to the enhancer role of the CaMV 35S promoter.RNAi and ectopic expression analysis of OsGA2ox6 indicated that the dwarf trait and the decreased levels of bioactive GAs in the H032 mutant were a result of the up-regulation of the OsGA2ox6 gene.BLASTP analysis revealed that OsGA2ox6 belongs to the class III of GA 2-oxidases,which is a novel type of GA2ox that uses C20-GAs (GA12 and/or GA53) as the substrates.Interestingly,we found that a GA biosynthesis inhibitor,paclobutrazol,positively regulated the OsGA2ox6 gene.Unlike the over-expression of OsGA2ox1,which led to a high rate of seed abortion,the H032 mutant retained normal flowering and seed production.These results indicate that OsGA2ox6 mainly affects plant stature,and the dominant dwarf trait of the H032 mutant can be used as an efficient dwarf resource in rice breeding.     

A novel butyrolactone derivative inhibited apoptosis and depressed integrin beta4 expression in vascular endothelial cells

To understand the effects of a novel butyrolactone derivative, 3-benzyl-5-((2-nitrophenoxy) methyl)-dihydrofuran-2(3H)-one (3BDO), on the apoptosis of vascular endothelial cells (VECs), we exposed 3BDO (20-60 microg/ml) to VECs deprived of serum and FGF-2 for 24 and 48 h, respectively. The results showed that 3BDO (20-60 microg/ml) increased VEC viability and inhibited VEC apoptosis induced by deprivation of serum and FGF-2 in a very weak dose-dependent manner. During this process, integrin beta4 expression was depressed, but the level of reactive oxygen species (ROS) was not changed. The data suggested that 3BDO (20-60 microg/ml) could inhibit VEC apoptosis and suppress integrin beta4 expression, but it could not depress the ROS level induced by deprivation of serum and FGF-2.     

Exogenous Melatonin Improves the Growth of Rice Seedlings by Regulating Redox Balance and Ion Homeostasis Under Salt Stress

This study evaluated the effects of foliar spraying melatonin (MT) on the growth of salt-stressed rice. Seedlings were treated with 50 and 100 mM of NaCl and different concentrations of MT (25, 50, 100, 200, 300, and 400 μM) for 14 days. Different concentrations of MT could promote plant growth significantly under salt stress, particularly at concentrations of 200, 300, and 400 μM. A concentration of 200 μM MT was considered as optimal and used in a subsequent experiment on biomass, water content, antioxidation, mineral nutrition, salt absorption, and distribution of salt-stressed rice seedlings. Results showed that MT’s promoting effect on plant growth under salt stress was evident with time, particularly under high salt stress. MT improved the activities of antioxidant enzymes, reduced membrane lipid peroxidation, alleviated cell injury in plant leaves, and increased N content and Si accumulation in the leaves and roots under salt stress, particularly under high salinity. This compound also inhibited Na uptake and upward transport, but it promoted or maintained the uptake and upward transport of K and Ca in salt-stressed rice. Thus, MT improved the ion homeostasis of K/Na and Ca/Na in plants, particularly in the leaves. Foliar spraying of MT alleviated salt stress on rice by promoting nutrient accumulation or translocation, improving ion homeostasis, which is evident in the leaves, and consequently enhancing its salt resistance. The antioxidative improvement caused by MT might also be related to the improved ion homeostasis.

     

稻田杂草稻发生情况调查

2007年杂草稻在江苏省海安县各类稻田中的发生率达44．35％,平均每公顷穴数和穗数分别为1023穴和10796穗,最高田块分别达12万穴和180万穗,已成为水稻生产上的潜在威胁。杂草稻在不同稻田的发生程度表现以下趋势：轻-中壤〉砂-轻壤〉重壤土稻田、直播〉抛栽〉机插〉手栽稻田、非统一供种〉统一供种稻田。     

Chloroquine inhibits cell growth and induces cell death in A549 lung cancer cells

To investigate the effects of chloroquine diphosphate (CQ) on lung cancer cell growth, we treated A549 cells, a lung cancer cell line, with the drug at various concentrations (0.25-128 microM) for 24-72 h. The results showed that, at lower concentrations (from 0.25 to 32 microM), CQ inhibited the growth of A549 cells and, at the same time, it induced vacuolation with increased volume of acidic compartments (VAC). On the other hand, at higher concentrations (64-128 microM), CQ induced apoptosis at 24 h, while its effect of inducing vacuolation declined. The lactate dehydrogenase (LDH) assay showed that with the treatment of CQ 32-64 microM for 72 h or 128 microM for 48 h, CQ induced necrosis of A549 cells. To understand the possible mechanism by which CQ acts in A549 cells, we further incubated the cells with this drug at the concentrations of 32 or 128 microM in the presence of D609, a specific inhibitor of phosphatidylcholine-specific phospholipase C (PC-PLC). The results showed that D609 (50 microM) could inhibit the effects of CQ 32 microM on the viability and VAC, but it could not change the effects of CQ 128 microM on the same. Our data suggested that CQ inhibited A549 lung cancer cell growth at lower concentrations by increasing the volume of lysosomes and that PC-PLC might be involved in this process. The data also indicated that, at higher concentrations, CQ induced apoptosis and necrosis, but at this time its ability to increase the volume of lysosome gradually declined, and PC-PLC might not be implicated in the process.     

OsREC8 is essential for chromatid cohesion and metaphase I monopolar orientation in rice meiosis

The successful transmission of chromosomes during mitosis and meiosis relies on the establishment and subsequent release of cohesion between replicated chromatids. Cohesion is mediated by a four-subunit structural maintenance of chromosome complex, called cohesins. REC8 is a key component of this meiotic cohesion complex in most model organisms studied to date. Here, we isolated and dissected the functions of OsREC8, a rice (Oryza sativa) REC8 homolog, using two null Osrec8 mutants. We showed that OsREC8 encodes a protein that localized to meiotic chromosomes from approximately meiotic interphase to metaphase I. Homologous pairing and telomere bouquet formation were abnormal in Osrec8 meiocytes. Furthermore, fluorescent in situ hybridization experiments on Osrec8 meiocytes demonstrated that the mutation eliminated meiotic centromeric cohesion completely during prophase I and also led to the bipolar orientation of the kinetochores during the first meiotic division and accordingly resulted in premature separation of sister chromatid during meiosis I. Immunolocalization analyses revealed that the loading of PAIR2, PAIR3, OsMER3, and ZEP1 all depended on OsREC8. By contrast, the presence of the OsREC8 signal in pair2, pair3, Osmer3, and zep1 mutants indicated that the loading of OsREC8 did not rely on these four proteins. These results suggest that OsREC8 has several essential roles in the meiotic processes.