Food Sources May Affect the Symptom Rates of COVID-19, an Epidemiological Analysis Based on the Public Data in Gansu Province, China, During the Summer Epidemic Cycle in 2022.

According to the public data collected from the Health Commission of Gansu Province, China, regarding the COVID-19 pandemic during the summer epidemic cycle in 2022, the epidemiological analysis showed that the pandemic spread stability and the symptom rate (the number of confirmed cases divided by the sum of the number of asymptomatic cases and the number of confirmed cases) of COVID-19 were different among 3 main epidemic regions, Lanzhou, Linxia, and Gannan; both the symptom rate and the daily instantaneous symptom rate (daily number of confirmed cases divided by the sum of daily number of asymptomatic cases and daily number of confirmed cases) in Lanzhou were substantially higher than those in Linxia and Gannan. The difference in the food sources due to the high difference of the population ethnic composition in the 3 regions was probably the main driver for the difference of the symptom rates among the 3 regions. This work provides potential values for prevention and control of COVID-19 in different regions.

Influences of fresh and frozen embryo transfer on neonatal birthweight and the expression of imprinted genes PEG10 /L3MBTL1 in placenta.

To investigate the influences of fresh embryo transfer (ET) and frozen embryo transfer (FET) on neonatal birthweight and the expression of imprinted genes PEG10 and L3MBTL1 in the placenta after in vitro fertilization-embryo transfer (IVF-ET), we analyzed the neonatal birthweight between fresh ET and FET transfer cycles. Then, we collected placentas delivered by fresh ET and FET, and real-time quantitative PCR, Western blotting and immunohistochemistry were used to detect the expression of PEG10 and L3MBTL1. The mean neonatal birthweight of fresh ET was lower than that of FET(3348.48 ± 521.05 vs. 3450.34 ± 524.13, P < 0.001). The risks of low birthweight (LBW) and small-for-gestational age (SGA) were lower after FET (3.9 % vs. 5.4 %; 7.2 % vs. 10.3 %), with adjusted rate ratios of 0.74 (95 % CI, 0.59-0.93; P = 0.003) and 0.70 (95 % CI, 0.59-0.84; P < 0.001), respectively. FET resulted in higher frequencies of macrosomia and large-for-gestational age (LGA) (14.2 % vs. 10.3; 11.0 % vs. 7.1 %) than fresh ET, with adjusted rate ratios of 1.45 (95 % CI, 1.26-1.68; P < 0.001) and 1.62 (95 % CI, 1.37-1.91; P < 0.001), respectively. We also observed PEG10 mRNA and protein expression levels in placentas delivered by fresh ET and FET were significantly different, but there were no significant differences in L3MBTL1 between the two groups. Fresh ET may affect the expression of the imprinted gene PEG10 in the placenta and adverse to placental implantation and development, resulting to increasing incidences of LBW and SGA.

Expression and DNA Methylation Status of the Imprinted Genes PEG10 and L3MBTL1 in the Umbilical Cord Blood and Placenta of the Offspring of Assisted Reproductive Technology.

The aim of this study is to investigate the expression and DNA methylation status of the imprinted genes PEG10 and L3MBTL1 in the offspring of assisted reproductive technology (ART). The ART group consists of 30 cases of placenta and umbilical cord blood from ART full-term, uncomplicated singleton pregnancy progeny, and the normal control group consists of 30 cases of placenta and umbilical cord blood from natural full-term, uncomplicated singleton pregnancy progeny. The imprinted genes PEG10 and L3MBTL1 are analyzed, and the expression and methylation status of the two genes are detected using real-time quantitative polymerase chain reaction (QRT-PCR), immunohistochemistry (IHC), Western blotting (WB), and methylation-specific polymerase chain reaction (MSP). Compared with the normal control group, the PEG10 mRNA relative quantity (RQ) value in the placenta is 0.994 ± 0.458, with its RQ value up-regulated (P = 0.015). The PEG10 mRNA RQ value in the umbilical cord blood is 0.875 ± 0.452, with its RQ value up-regulated (P = 0.002). However, the L3MBTL1 mRNA RQ value in the placenta is 0.404 ± 0.234, with its RQ value down-regulated (P = 0.024). The L3MBTL1 mRNA RQ value in the umbilical cord blood is 0.337 ± 0.213, and there is no difference in the umbilical cord blood (P = 0.081). Compared with the normal control group, the expression of PEGl0 protein in the placenta of the ART progeny is up-regulated (P = 0.000), while the expression of L3MBTLl protein is down-regulated (P = 0.000). The methylation status of the PEGl0 promoter region in the placenta in the ART group is lower than that in the normal control group (P = 0.037), and that of the promoter region of the umbilical cord blood is lower than that of the natural pregnancy group (P = 0.032). The methylation status of the L3MBTLl promoter region is higher in the placenta than in the normal control group (P = 0.038), and there is no difference between the two groups in the umbilical cord blood (P = 0.301). In the ART group, the values of PEGl0 and L3MBTLl RQ in the placenta and the umbilical cord blood of the hypermethylated group are lower than in those of the hypomethylated group. ART may increase the risk of the abnormal expression of PEG10 and L3MBTL1 in offspring imprinted genes. The methylation of the promoter region may be the mechanism that regulates the expression of PEGl0 and L3MBTL1.