[Fecal rotavirus and adenovirus antigen detection and clinical analysis of children with acute gastroenteritis in a hospital of Beijing City from 2019 to 2022]

As a single-center retrospective study, we analyzed the results of rotavirus and human adenovirus antigens in stool samples with colloidal gold immunochromatography method in children with acute gastroenteritis under the age of five who were treated in our hospital from 2019 to 2022. After excluding nonconforming cases and duplicate cases, 2 896 cases were included, of which 559 cases were detected with at least one viral antigen. According to the test results, they were divided into RV positive group, HAdV positive group and RV & HAdV double positive group. The gender, age, seasonal distribution, clinical symptoms and related laboratory tests were compared and analyzed with χ² test, analysis of variance and nonparametric test. Among the single samples from 2 896 children, the positive rate of RV antigen was 6.21% (180/2 896), the positive rate of HAdV antigen was 10.91% (316/2 896), and the double positive rate of RV & HAdV was 2.18% (63/2 896). The positive rate of HAdV antigen in 2021 was 16.11%, a significant increase compared with 6.20% in 2020. RV infection has obvious seasonality, and spring and winter are the seasons with high incidence of infection (χ²=74.018, P<0.001), while HAdV infection has no obvious seasonality (χ²=2.110, P=0.550), showing sporadic infection throughout the year. The proportions of fever and vomiting symptoms in children with RV infection were significantly higher than those in the HAdV infection group (χ²=40.401, P<0.001; χ²=32.593, P<0.001), but the positive rate of white blood cells in the stool was significantly lower than that in the HAdV infection group (χ²=13.741,P<0.01). In summary, paying attention to the epidemiological changes of RV and HAdV is of great significance for clinical diagnosis and treatment and disease prevention and control.

Circular ribonucleic acid circ-FADS2 promotes colorectal cancer cell proliferation and invasion by regulating miR-498/S100A16

The aim of this study is to examine the role and functional mechanism of circ-FADS2 in colorectal cancer (CRC). The levels of expression of circ-FADS2 were detected in 48 patients with CRC and their paired normal tissue samples and cell lines (SW480, SW620, HCT116, HT29, and NCM460) using quantitative real-time polymerase chain reaction (qRT-PCR). Circ-FADS2 was then silenced in SW480 and HT29 cells using two small interfering ribonucleic acids. Themolecular mechanism of circ-FADS2 in CRC progression and migration was then examined by sponging miR-498 and promoting S100A16 expression. After this, the expression of miR-498 and S100A16 in CRC tissues was analyzed using a qRT-PCR. In results: circ-FADS2 was found to be significantly upregulated in CRC tissues, when compared with paired normal tissues. Higher circ-FADS2 expression was associated with advanced stages, lymphatic metastasis, and reduced overall survival (OS). In addition, silencing circ-FADS2 markedly inhibited the proliferation and invasion of CRC and increased the percentage of cancer cells in the G1 phase in vitro. Reducing circ-FADS2 decreased SW480 cell proliferation in vivo. By inhibiting miR-498 expression, circ-FADS2 promoted S100A16 expression leading to the activation of the AKT pathway, resulting in CRC progression. We conclude that Circ-FADS2 expression was upregulated in CRC tissues and cells and was found to be correlated with advanced cancer, metastasis, and poor OS. A study of the molecular mechanism suggests that a circ-FADS2/miR-498/S100A16/AKT signaling cascade may be a potential therapeutic target for the treatment of CRC.

Cloning and expression of an APETALA1-like gene from Nelumbo nucifera

The objective of this study was to clone the full-length cDNA of the APETALA1 (AP1) gene from lotus and analyze its sequence and expression pattern. The full-length cDNA sequence of the NnAP1 gene was amplified from the petals of Nelumbo nucifera 'Hongxia' using RT-PCR and rapid amplification of cDNA ends. Bioinformatic methods were used to analyze the sequence characteristics of the gene. Quantitative real-time PCR methods were used to investigate the expression pattern of NnAP1 in various organs and during different developmental stages. The cloned full-length NnAP1 cDNA (GenBank accession No. KF361315) was 902 bp, containing a 795-bp open reading frame encoding 264 amino acids with a relative molecular mass of 30,288.4 and an isoelectric point of 9.13. NnAP1 had a MADS-box domain and a K-box domain, which is typical of the SQUA/AP1 gene family. A protein sequence identity search showed that NnAP1 was 75-96% similar to other plant AP1s. Phylogenetic tree analysis indicated that NnAP1 was very closely related to AP1 of Glycine max, suggesting that they shared the same protein ancestor. Quantitative real-time PCR analysis showed that NnAP1 was expressed in various organs during different developmental stages; it had the highest expression in blooming flowers and had trace expression in the young vegetative and flower senescence stages. Our analysis suggests that NnAP1 plays an important role in controlling floral meristem identity and floral organ formation.

Pharmacokinetics and metabolism of 1,5-dicaffeoylquinic acid in rats following a single intravenous administration

1,5-Dicaffeoylquinic acid (1,5-DCQA) is a potentially important HIV-1 integrase inhibitor widely distributed in many plants. To characterize the pharmacokinetic and metabolic properties of 1,5-DCQA in rats following single intravenous administration (160 mg/kg), the plasma concentrations of 1,5-DCQA were measured by high-performance liquid chromatography (HPLC) and the metabolites formed in urine were identified by liquid chromatography-mass spectrometry (LC-MS) in parallel to diode-array detection (DAD). The results showed that the concentrations of 1,5-DCQA in plasma declined rapidly in a biphasic manner with a mean terminal half-life (t(1/2)) of 1.40 h. The mean clearance (CL) and the apparent volume of distribution (Vd(B)) of 1,5-DCQA were 0.44l/h/kg and 0.89l/kg, respectively. A total of 15 metabolites in rat urine were identified, including four isomeric O-mono-methylated (M1-M4), six isomeric O-di-methylated (M5-M10), one isomeric O-mono-methyl-glucuronidated (M11) and four isomeric O-di-methyl-glucuronidated (M12-M15) metabolites. The O-methylation positions of three important metabolites (M1, M2 and M5) were determined (3''-, 3'-, and 3',3''-) by comparing with synthesized standards. These results suggested that the disappearance of 1,5-DCQA from plasma was rapid, and that its quick urinary excretion and extensive metabolism, including methylation and glucuronidation, were two factors causing its rapid elimination from the circulation.

The rice Rim2 transcript accumulates in response to Magnaporthe grisea and its predicted protein product shares similarity with TNP2-like proteins encoded by CACTA transposons

A rice transcript, Rim2, was identified that accumulated in both incompatible and compatible interactions between rice and Magnaporthe grisea. The Rim2 transcript also accumulated in response to treatment with a cell wall elicitor derived from M. grisea. A 3.3-kb RIM2 cDNA clone was isolated and is predicted to encode a protein of 653 amino acids, which shares 32 55% identity with TNP2-like proteins encoded by CACTA transposons of other plants. A 1.05-kb segment of the Rim2 sequence shows 82% nucleotide sequence identity with sequences flanking the A1 and C members of the rice Xa21 disease resistance gene family. The 5'-upstream region of Rim2 was cloned and the transcriptional start sites were identified. The 5' and 3' noncoding termini of Rim2 are AT-rich. A cis-element showing similarity to a sequence that mediates defense-associated transcriptional activation of the tobacco retrotransposon Tnt1, and four motifs that fit the consensus sequence of the elicitor-responsive elements in the promoters of the parsley PR-1 genes were found in the 5'-upstream region. Four imperfect tandem repeats were identified in the 3' noncoding terminus. Southern analysis with genomic DNA from different rice species indicated that Rim2 is present in 3-4 copies per genome. These results suggest that Rim2 may be one component of a large CACTA-like element, whose transcript accumulates in response to attack by pathogens.

Replacing Solvent Drying Technique for Nanometer Particle Preparation

A prepration technique for nanometer particles, namely the replacing solvent drying technique, was developed. The main process of the technique including replacement of water in gel with special organic solvent and the removal of the solvent by distillation. No collapse of gel structure took place because of low interface tension between water and the solvent as well as low surface tension of the solvent. Where special apparatus and strictly limited preparation conditions were not necessary. The technique is noted for its low preparation cost and high universality. Titanium oxide and copper borate were prepared using the technique and were characterized using XRD, nitrogen physical adsorption, TEM, and small angle X-ray scattering. Results indicated that the titanium oxide and copper borate possessed particle sizes of 7-10 and 7-20 nm as well as a specific surface area of 235 m2/g and 360 m2/g, respectively. The specific surface area were even much higher than that of the samples prepared using supercritical drying technique. Copyright 1998 Academic Press.