The rapid accumulation of mutations in the SARS-CoV-2 Omicron variant that enabled its outbreak raises questions as to whether its proximal origin occurred in humans or another mammalian host. Here, we identified 45 point mutations that Omicron acquired since divergence from the B.1.1 lineage. We found that the Omicron spike protein sequence was subjected to stronger positive selection than that of any reported SARS-CoV-2 variants known to evolve persistently in human hosts, suggesting a possibility of host-jumping. The molecular spectrum of mutations ( i.e. , the relative frequency of the 12 types of base substitutions) acquired by the progenitor of Omicron was significantly different from the spectrum for viruses that evolved in human patients, but resembled the spectra associated with virus evolution in a mouse cellular environment. Furthermore, mutations in the Omicron spike protein significantly overlapped with SARS-CoV-2 mutations known to promote adaptation to mouse hosts, particularly through enhanced spike protein binding affinity for the mouse cell entry receptor. Collectively, our results suggest that the progenitor of Omicron jumped from humans to mice, rapidly accumulated mutations conducive to infecting that host, then jumped back into humans, indicating an inter-species evolutionary trajectory for the Omicron outbreak.

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The rapid accumulation of mutations in the SARS-CoV-2 Omicron variant that enabled its outbreak raises questions as to whether its proximal origin occurred in humans or another mammalian host. Here, we identified 45 point mutations that Omicron acquired since divergence from the B.1.1 lineage. We found that the Omicron spike protein sequence was subjected to stronger positive selection than that of any reported SARS-CoV-2 variants known to evolve persistently in human hosts, suggesting the possibility of host-jumping. The molecular spectrum (i.e., the relative frequency of the twelve types of base substitutions) of mutations acquired by the progenitor of Omicron was significantly different from the spectrum for viruses that evolved in human patients, but was highly consistent with spectra associated with evolution in a mouse cellular environment. Furthermore, mutations in the Omicron spike protein significantly overlapped with SARS-CoV-2 mutations known to promote adaptation to mouse hosts, particularly through enhanced spike protein binding affinity for the mouse cell entry receptor. Collectively, our results suggest that the progenitor of Omicron jumped from humans to mice, rapidly accumulated mutations conducive to infecting that host, then jumped back into humans, indicating an inter-species evolutionary trajectory for the Omicron outbreak.

One thousand three hundred seventy-nine nasopharyngeal carcinoma (NPC) patients were treated from March 1958 to December 1978. Twenty-two percent had stage I or II and 78% Stage III or IV had lesions. Two hundred twenty-Kv radiographs were used before 1960; and telecobalt was used from 1961 to 1978. Factors influencing the 5-year survival rate favorably are youth of patient, being female, pathologic condition (poorly differentiated carcinoma, 45.1% versus adenocarcinoma, 13%), stage (Stage I, 86%, Stage II, 59.5%; Stage III, 45.8%; Stage IV, 29.2%), decade admitted for treatment in the past (31% in the 1950s, 48.6% in the 1970s), total dose delivered to the nasopharynx (40 to 49 Gy, 46%; 70 to 79 Gy, 54.1%; 90 Gy or more, 64%) and prophylactic radiation to the neck regions (with prophylactic irradiation, 53.8%, without prophylactic irradiation, 23%). This implies that prophylactic radiation of the neck is crucial even without positive clinical metastasis. For those who have a residual tumor in the primary site when 70 Gy has been delivered, the total dose may be boosted to more than 90 Gy with the cone-down technique or on basis of adding 20 Gy to the dose at which the primary lesion disappeared grossly. The common postirradiation complications are: radiation myelitis, trismus, and otitis media. Because disease recurred in some patients after the fifth year, NPC patients should be followed for at least 10 years.

Resveratrol, the most important ingredient extracted from Polygonum cuspidatum, exerts cytoprotective effects via anti-inflammatory actions in vitro. In this study, we investigated this effect of resveratrol on the lipopolysaccharide (LPS)-induced inflammatory response and its underlying molecular mechanism of action in RAW264.7 murine macrophages. Results showed that resveratrol down-regulated the expression of inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6), therefore, suppressed the production of nitric oxide and the secretion of IL-6 in LPS-stimulated RAW264.7 cells in a dose-dependent manner. Resveratrol also inhibited the translocation of highmobility group box 1 (HMGB1) from the nucleus to the cytoplasm and of nuclear transcription factor kappa-B (NF-κB) p65 from the cytoplasm to the nucleus; it suppressed the phosphorylation of IκBα. Furthermore, these actions were mediated by suppressing the phosphorylation of signal transducer and activator of transcription (STAT)-1 and -3. In conclusion, these data indicate that resveratrol exerts anti-inflammatory effects, at least in part by reducing the release of HMGB1 and modulating the NF-κB and Janus kinase/STAT signaling pathways. Resveratrol could potentially be developed as a useful agent for the chemoprevention of inflammatory diseases.

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Long-term high-dose NAC treatment may lead to a lower rate of exacerbations. But the effect of low-dose NAC treatment remains uncertain. Further researches are needed to confirm this outcome and to clarify its mechanisms.