Objective: To estimate the latent period and incubation period of Omicron variant infections and analyze associated factors. Methods: From January 1 to June 30, 2022, 467 infections and 335 symptomatic infections in five local Omicron variant outbreaks in China were selected as the study subjects. The latent period and incubation period were estimated by using log-normal distribution and gamma distribution models, and the associated factors were analyzed by using the accelerated failure time model (AFT). Results: The median (Q₁, Q₃) age of 467 Omicron infections including 253 males (54.18%) was 26 (20, 39) years old. There were 132 asymptomatic infections (28.27%) and 335 (71.73%) symptomatic infections. The mean latent period of 467 Omicron infections was 2.65 (95%CI: 2.53-2.78) days, and 98% of infections were positive for nucleic acid test within 6.37 (95%CI: 5.86-6.82) days after infection. The mean incubation period of 335 symptomatic infections was 3.40 (95%CI: 3.25-3.57) days, and 97% of them developed clinical symptoms within 6.80 (95%CI: 6.34-7.22) days after infection. The results of the AFT model analysis showed that compared with the group aged 18-49 years old, the latent period [exp(β)=1.36 (95%CI: 1.16-1.60), P<0.001] and incubation period [exp(β)=1.24 (95%CI: 1.07-1.45), P=0.006] of infections aged 0-17 years old were prolonged. The latent period [exp(β)=1.38 (95%CI: 1.17-1.63), P<0.001] and the incubation period [exp(β)=1.26 (95%CI: 1.06-1.48), P=0.007] of infections aged 50 years old and above were also prolonged. Conclusion: The latent period and incubation period of most Omicron infections are within 7 days, and age may be a influencing factor of the latent period and incubation period.
Male ; Humans ; Adult ; Adolescent ; Young Adult ; Middle Aged ; Infant, Newborn ; Infant ; Child, Preschool ; Child ; COVID-19 ; SARS-CoV-2 ; Infectious Disease Incubation Period ; Asymptomatic Infections

Vascular endothelial cells and oxidation reduction system play an important role in the pathogenesis of atherosclerosis (AS). If these conditions are disordered, it will inevitably lead to plaque formation and even rupture. Astragaloside IV (AsIV) and salvianolic acid B (Sal B) are the main active ingredients of Astragalus membranaceus and Salvia miltiorrhiza, respectively, and found to ameliorate vascular endothelial dysfunction and protect against oxidative stress in recent studies. However, it is still unknown if the combination of AsIV and Sal B (AsIV + Sal B) can inhibit the development of plaque through amplifying the protective effect of vascular endothelial cells and anti-oxidative stress effect. To clarify the role of AsIV + Sal B in AS, we observed the efficacy of each group (Control, Model, AsIV, Sal B, and AsIV + Sal B) by biomolecular assays, such as observing the pathological morphology of the aorta by oil red O staining, evaluating the level of oxidative stress and endothelial cells in the serum by the Elisa test, and analyzing the changes of all small molecule metabolites in liver tissue by UPLC-QTOF-MS. Results showed that AsIV, Sal B and AsIV + Sal B decreased the deposition of lipid in the arterial wall, so as to exert the effect of anti-oxidant stress and vascular endothelial protection, where the inhibitory effect of AsIV + Sal B was the most obvious. Metabonomics analysis showed that Sal B regulated the metabolic pathways of arginine and proline. AsIV regulated glycerol metabolism and saturated fatty acid biosynthesis metabolism. AsIV + Sal B is mainly related to the regulation of the citrate cycle (TCA cycle), alanine, aspartic acid, and glutamate metabolism, cysteine, and methionine metabolism. Succinic acid and methionine are synergistic metabolites that exert an enhancing effect when AsIV and Sal B were used in combination. In conclusion, we demonstrated that AsIV acompanied with Sal B can be successfully used for anti-oxidative stress and vascular endothelial protection of AS, and succinic acid and methionine are the synergistic metabolites.
Antioxidants ; Atherosclerosis ; Benzofurans ; Endothelial Cells ; Humans ; Methionine ; Saponins ; Succinic Acid ; Triterpenes

Objective:To explore the effects of Shenwei Ningyu pills （SNP）， a new Chinese medicine for depression， on the immunoinflammatory response mediated by Toll-like receptor 4 （TLR4）/myeloid differentiation factor 88 （MyD88） signaling pathway in the hippocampus of rats exposed to chronic restraint stress （CRS）. Method:Forty-four male Sprague Dawley rats were randomly enrolled into a normal group， a model group， an escitalopram group， and an SNP group. Except for the rats in the normal group， all rats were exposed to CRS and isolated rearing for 21 days continuously. Rats in the escitalopram group and the SNP group were administered with escitalopram （30 mg·kg^-1） and SNP （18 mg·kg^-1） one hour prior to CRS， respectively. The changes in body weight， sucrose preference index， horizontal movement scores， and vertical movement scores were observed by body weight assessment， sucrose preference test， and open field test. The expression of hippocampal TLR4 and MyD88 was detected by Western blot. The content of serum interleukin-1β （IL-1β）， IL-10， and tumor necrosis factor-α （TNF-α） was detected by enzyme-linked immunosorbent assay （ELISA）. Result:The results of the behavioral assessment showed that there was no significant difference in the changes of behavioral baselines among the groups before intervention. However， significant differences were found among the groups following different interventions. The body weight， sugar preference index， horizontal movement score， and vertical movement score of rats in the model group decreased after CRS for 21 days as compared with those in the normal group （P<0.01）. The above indicators in the SNP group and the escitalopram group were higher than those in the model group （P<0.01）， which indicated that SNP exerted an obvious antidepressant effect. The results of Western blot and ELISA showed that compared with the normal group， the model group showed elevated levels of hippocampal TLR4 and MyD88 and serum IL-1β and TNF-α （P˂0.01） and dwindled serum IL-10 （P˂0.01）， while SNP and escitalopram reversed the conditions in the model group （P˂0.01） except for TNF-α. Conclusion:The present study indicated that the antidepressant effect of SNP was presumedly achieved by inhibiting the immunoinflammatory response mediated by the TLR4/Myd88 signaling pathway in CRS rats.

Objective:Metabolomics was used to analyze the brain tissue samples of model mice with chronic unpredictable mild stress (CUMS) depression, in order to find out the differential metabolites related to depression and to explore the possible antidepressant mechanism of iridoid part of Valerianae Jatamansi Rhizoma et Radix (IEFV). Method:Forty-two Kunming mice were randomly divided into 6 groups, including the normal group, the model group, the fluoxetine group (2.5 mg·kg^-1) and the IEFV low, medium, and high dose groups (doses were 5.73, 11.47, 22.94 mg·kg^-1, respectively). The behavioral and biochemical indicators of CUMS model mice were used for pharmacodynamic evaluation with IEFV and a positive drug (fluoxetine) as the intervention drugs. Then, the effect of IEFV on endogenous substances of the brain tissue in CUMS model mice were analyzed by nuclear magnetic resonance hydrogen spectrum (¹H-NMR) metabolomics, and multivariate statistical analysis was used to identify the differential metabolites and to enrich the metabolic pathways involved in the differential metabolites. Result:After modeling, the immobility time of the model mice increased significantly, their sucrose preference rate and the excitatory neurotransmitters [5-hydroxytryptamine (5-HT) and norepinephrine (NE)] decreased significantly, indicating the success of modeling. The depression was relieved after IEFV administration, mainly manifested by the recovery of the immobility time, sucrose preference rate and the excitatory neurotransmitters (5-HT and NE). Principal component analysis (PCA) of endogenous metabolites in brain tissue showed that the model group could be significantly separated from the normal group, while the IEFV groups and fluoxetine group all showed a trend of deviating from the model group to the normal group, which was consistent with the behavioral results. The results of orthogonal partial least squares discriminant analysis (OPLS-DA) showed that there were 16 different metabolites between the model group and the normal group, including 12 water-soluble metabolites and 4 liposoluble metabolites. Seven potential metabolism pathways were obtained through MetPA analysis, including metabolism of phenylalanine, metabolism of phenylalanine, tyrosine and tryptophan, metabolism of taurine and hypotaurine acid, metabolism of alanine, aspartic acid and glutamic acid, biosynthesis of valine, leucine and isoleucine, metabolism of D-glutamine and D-glutamate and tricarboxylic acid cycle (TCA). IEFV-high dose group could significantly recall 11 differential metabolites. Conclusion:IEFV may play an antidepressant role mainly by affecting energy metabolism, amino acid metabolism and neurotransmitter levels, which provides a reference for further study on the antidepressant mechanism of IEFV.