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Background Folate, including the folic acid form, is a key component of the one-carbon metabolic pathway used for DNA methylation. Changes in DNA methylation patterns during critical development periods are associated with disease outcomes and are associated with changes in nutritional status in pregnancy. The long-term impact of periconceptional folic acid supplementation on DNA methylation patterns is unknown. Objectives To determine the long-term impact of periconceptional folic acid supplementation on DNA methylation patterns, we examined the association of the recommended dosage (400 μg/d) and time period (periconceptional before pregnancy through first trimester) of folic acid supplementation with the DNA methylation patterns in the offspring at age 14–17 y compared with offspring with no supplementation. Methods Two geographic sites in China from the 1993–1995 Community Intervention Program of folic acid supplementation were selected for the follow-up study. DNA methylation at 402,730 CpG sites was assessed using saliva samples from 89 mothers and 179 adolescents (89 male). The mean age at saliva collection was 40 y among mothers (range: 35–54 y) and 15 y among adolescents (range: 14–17 y). Epigenome-wide analyses were conducted to assess the interactions of periconceptional folic acid exposure, the 5,10-methylenetetrahydrofolate reductase (MTHFR) -C677T genotype, and epigenome-wide DNA methylation controlling for offspring sex, geographic region, and background cell composition in the saliva. Results In the primary outcome, no significant differences were observed in epigenome-wide methylation patterns between adolescents exposed and those non-exposed to maternal periconceptional folic acid supplementation after adjustment for potential confounders [false discovery rate (FDR) P values < 0.05]. The MTHFR-C677T genotype did not modify this lack of association (FDR P values < 0.05). Conclusions Overall, there were no differences in DNA methylation between adolescents who were exposed during the critical developmental window and those not exposed to the recommended periconceptional/first-trimester dosage of folic acid. [ABSTRACT FROM AUTHOR]

Although a number of cases of importation with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, there are still no data available concerning the characteristics in the coronavirus disease 2019 (COVID-19) cluster of charter flight importation. Here, we provide an analysis of COVID-19 cases and their close contacts who worked for the same company on a project in Karbala, Iraq, and returned back to Chengdu, China, by a charter flight. The data of imported COVID-19 cases and their close contacts were obtained from National Notifiable Disease Report System of Chinese Center for Disease Control and Prevention and field epidemiological investigation reports by Centers for Disease Control and Prevention (CDCs) in Chengdu. The information of general characteristics and laboratory findings of this cluster were collected and summarized. One hundred and six (66.67%) of 159 charter flight passengers tested positive for COVID-19 before entry. Through treatment, all 159 people tested negative and meet the requirements of taking flights bound for China before boarding. However, there has been still 36 (22.64%) of them tested positive after entry. The median time from entry to confirmation was 1.0 day (Interquartile Range (IQR): 0–4.3). The Cycle threshold value (Ct value) of 36 patients' positive samples are all above 30 and most values are above 35. In conclusion, there is still a risk that a number of COVID-19 cases can be imported through charter flight. However, the infectivity of confirmed patients of the charter flight was considered to be low. [ABSTRACT FROM AUTHOR]

A virulent strain NE/09 of porcine parvovirus (PPV) was isolated from mummified swine fetus samples in China and its capsid protein VP2 gene was analyzed. The data showed that the VP2 gene encompassed an open reading frame of 1713 nucleotides with a composition of 684 adenine (39.9%), 387 cytosine (22.6%), 268 guanine (15.7%), and 374 thymine (21.8%). The VP2 gene encoded a 570aa-long protein which could be recognized by anti-PPV-VP2 monoclonal antibody 3C9. Sequence analysis revealed that the VP2 gene of PPV-NE/09 had close sequence similarity with the VP2 gene of other PPV strains. However, a 27 nucleotide region that encodes a glycine-rich domain at the N-terminal region of VP2 was deleted in the PPVNE/ 09 strain. The PPV-NE/09 virions were purified by 1.39 g/ml CsCl density centrifugation and subjected to SDS-PAGE analysis. The results showed that only two major polypeptides VP1 and VP2 with molecular weights of 83 and 64 kDa, respectively were observed, whereas VP3 with a molecular weight of 60 kDa was not present, in contrast to the PPV-NADL-2 strain. According to the phylogenetic relationship of the VP2 gene of PPV-NE/09, the isolate was a new mutant strain of PPV prevailing in China. [ABSTRACT FROM AUTHOR]