Background: Strict countermeasures for coronavirus disease (COVID-19) were undertaken in China without knowing their influence on asthma.Objective: To investigate the associations between the frequencies of asthma exacerbations and respiratory infections and air pollutants before and during the COVID-19 pandemic, which were direct consequences of countermeasures undertaken for the pandemic.Methods: Asthma exacerbations and respiratory infections among hospitalized children in the permanent population of Guangzhou City, China, from February to June 2016-2019 (before the pandemic) to February to June 2020 (during the pandemic) were collected in this cross-sectional study in Guangzhou.Results: The number of asthma exacerbation cases per month documented in the Guangzhou Women and Children's Hospital before (median: 13.5; range: 0-48) and during (median: 20; range: 0-34) the mitigative response to the COVID-19 pandemic was similar. The frequency of severe asthma exacerbation cases per month decreased, whereas that of mild asthma exacerbation cases per year increased (p = .004). The number of patients hospitalized with infectious respiratory diseases decreased from 146 (range: 90-172) per month before the pandemic to 42 (range: 33-57) per month during the pandemic (p = .004). Most pathogens and air pollutants decreased during the COVID-19 pandemic. The frequency of severe asthma exacerbations positively correlated to that of respiratory infections in children, but did not correlate to air pollutants. Conclusion:Strict countermeasures undertaken for the pandemic were associated with a decreased the frequency of infectious respiratory diseases and severe asthma exacerbations among urban children.

Abstract. Recepteur d'origine nantais (RON) is a receptor tyrosine kinase (RTK) normally expressed at low levels in epithelial cells. RON is a 180-kDa heterodimeric protein composed of a 40-kDa α-chain and a 150-kDa transmembrane β-chain with intrinsic tyrosine kinase activity. The extracellular sequences of RON contain several domains including an N-terminal semaphorin (sema) domain, followed by the plexin, semaphorin, integrin (PSI) domain, and four immunoglobulin, plexin, transcription factor (IPT) domains. Here, we identified RON genes from 14 vertebrate genomes and found that RON exists in all types of vertebrates including fish, amphibians, birds and mammals. We found that the human RON gene showed predominant expression in the liver, lymph node, thymus, intestine, lung, mammary gland, bone marrow, brain, heart, placenta, bladder, cortex, cervix, skin, kidney and prostate. When searched in the PrognoScan database, human RON was also found to be expressed in bladder, blood, breast, glioma, esophageal, colorectal, head and neck, ovarian, lung and skin cancer. The relationship between the expression of RON and prognosis was found to vary in different cancer types, even in the same cancer from different databases. This suggests that the function of RON in these tumors may be multidimensional, not just as a tumor suppressor or oncogene. Six available single-nucleotide polymorphisms (SNPs) disrupting existing exonic splicing enhancers were identified in RON. This may contribute to the generation of active RON variants by alternative splicing, which is frequently observed in primary tumors.

ABSTRACT.Objective: To investigate the ocular hypertensive response to topical dexamethasone (DEX), rimexolone (RIM), loteprednol etabonate (LOT) and fluorometholone (FML) in rabbits of different ages. Methods: Seventy-five rabbits of three age groups (7 weeks, 6 months and 1-year old) received topical administration of 0.1% DEX, 1% RIM, 0.5% LOT, 0.1% FML or balanced salt solution four times daily for 1 month. Intraocular pressure (IOP) was monitored at regular time intervals. After a month, eyes were harvested for histological study with haematoxylin and eosin (H&E), periodic acid Schiff and Masson trichrome staining. Trabecular meshwork changes were graded by masked ocular pathologists. Results: Topical DEX caused the greatest increase in IOP, followed by RIM and FML. LOT caused the least IOP increase. Similar pattern of IOP response to the four corticosteroids was observed in the three studied age groups. Young rabbits (7 week) were the most responsive to corticosteroids among the age groups. Extracellular matrix thickening in the trabecular meshwork region and loss of trabecular meshwork cells were observed after DEX, FML or RIM treatments. Conclusion: Young rabbits are more susceptible to steroid induced increase in IOP, even for milder steroids such as fluorometholone and rimexolone.

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Helicobacter pylori has infected more than half of the world's population, causing gastritis, gastric ulcers, gastric mucosa-associated lymphoid tissue lymphoma and gastric cancer. The oral recombinant Helicobacter pylori vaccine currently used has made great progress in addressing this problem, however, its efficacy and longevity still need to be improved. Th1 and Th17 cells play essential roles in local protection against Helicobacter pylori in the stomach mucosa. Additionally, protective immunodominant antigens are the preferred for a vaccine. In this work, Helicobacter pylori whole cell lysate was separated into 30 groups based on molecular weight by molecular sieve chromatography. The group best promoting CD4 T cells proliferation was selected and evaluated by immunization. The detail proteins were then analyzed by LC-MS/MS and expressed in Escherichia coli. Eleven proteins were selected and the dominant ones were demonstrated. As a result, three protective immunodominant antigens, inosine 5'-monophosphate dehydrogenase, type II citrate synthase, and urease subunit beta, were selected from Helicobacter pylori whole cell. Two of them (inosine 5'-monophosphate dehydrogenase and type II citrate synthase) were newly identified, and one (urease subunit beta) was confirmed as previously reported. The mixture of the three antigens showed satisfactory protective efficiency, with significant lower H. pylori colonization level (P < 0.001) and stronger Th1 (P < 0.001) and Th17 (P < 0.001) responses than PBS control group. Thus, inosine 5'-monophosphate dehydrogenase, type II citrate synthase, and urease subunit beta are three protective antigens inducing dominant Th1 and Th17 responses to defend against Helicobacter pylori infection.

In apoptotic progress of tumor cells stimulated by special agents, the calreticulin (CRT) was relocated from endoplasmic reticulum onto the cell surface. When used as cellular antigen to immunize experimental animals, these CRT-coated apoptotic tumor cells could initiate effective anti-tumor immunoresponse against homologous tumor cells, indicating the value of CRT in anti-tumor immunotherapy. In order to develop an universal technique that could make CRT-coating more efficiently in the tumor cells, in this study, a mouse CRT recombinant gene with virus G-protein coupled receptor (vGPCR) was constructed and cloned into vector pcDNA3.1(+). When resulted plasmid pcDNA3.1(+)-mCRT/ vGPCR was stably transfected into the mouse melanoma B16-F1 cells, the mCRT-vGPCR recombinant protein was synthesized. With the membrane-locating ability of vGPCR in the recombinant protein, mCRT-vGPCR was carried onto the surface of B16-F1 cells efficiently. Overexpression of mCRT-vGPCR on the cell surface could enhance the phagocytosis of B16-F1 by macrophages in vitro. When mCRT-vGPCR coated B16-F1 cells were used as a cell-antigen to immunize mice, the specific anti-tumor immune response against the homologous tumor cells was initiated efficiently. Our data in this study may provide a new possibility for CRT-mediated tumor immune prevention and treatment.

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