Local area community cumulative incidence (per 1,000 population) Health care personnel with positive test results for SARS-CoV-2 antibodies (%) Abbreviation: COVID-19 = coronavirus disease 2019. * Calculated as the total number of reported community COVID-19 cases within a hospital-area county or counties between the beginning of the pandemic and 7 days after the first day of health care personnel enrollment at the hospital divided by population of the county or counties x 1,000.

Hepatitis B virus gene expression is to a large extent under the control of enhancer I (EnhI). The activity of EnhI is strictly dependent on the enhancer factor C (EF-C) site, an inverted repeat that is bound by a ubiquitous nuclear protein known as EF-C. Here we report the unexpected finding that EF-C is in fact identical to RFX1, a novel transcription factor previousiy cloned by virtue of its affinity for the HLA class II X-box promoter element. This finding has allowed us to provide direct evidence that RFX1 (EF-C) is crucial for EnhI function in HepG2 hepatoma cells; RFXl-specific antisense oligonucleotides appear to inhibit EnhI-driven expression of the hepatitis B virus major surface antigen gene, and in transfection assays, RFX1 behaves as a potent transactivator of EnhI. Interestingly, transactivation of EnhI by RFX1 (EF-C) is not observed in cell lines that are not of liver origin, suggesting that the ubiquitous RFX1 protein cooperates with liver-specific factors.

Background SARS-CoV-2, the virus that causes COVID-19 disease, was first identified in Wuhan, China in December 2019, with subsequent worldwide spread. The first U.S. cases were identified in January 2020. Methods To determine if SARS-CoV-2 reactive antibodies were present in sera prior to the first identified case in the U.S. on January 19, 2020, residual archived samples from 7,389 routine blood donations collected by the American Red Cross from December 13, 2019 to January 17, 2020, from donors resident in nine states (California, Connecticut, Iowa, Massachusetts, Michigan, Oregon, Rhode Island, Washington, and Wisconsin) were tested at CDC for anti-SARS-CoV-2 antibodies. Specimens reactive by pan-immunoglobulin (pan Ig) enzyme linked immunosorbent assay (ELISA) against the full spike protein were tested by IgG and IgM ELISAs, microneutralization test, Ortho total Ig S1 ELISA, and receptor binding domain / Ace2 blocking activity assay. Results Of the 7,389 samples, 106 were reactive by pan Ig. Of these 106 specimens, 90 were available for further testing. Eighty four of 90 had neutralizing activity, 1 had S1 binding activity, and 1 had receptor binding domain / Ace2 blocking activity >50%, suggesting the presence of anti-SARS-CoV-2-reactive antibodies. Donations with reactivity occurred in all nine states. Conclusions These findings suggest that SARS-CoV-2 may have been introduced into the United States prior to January 19, 2020.

IMPORTANCEAs self-collected home antigen tests become widely available, a better understanding of their performance during the course of SARS-CoV-2 infection is needed. OBJECTIVE To evaluate the diagnostic performance of home antigen tests compared with reverse transcription-polymerase chain reaction (RT-PCR) and viral culture by days from illness onset, as well as user acceptability. DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study was conducted from January to May 2021 in San Diego County, California, and metropolitan Denver, Colorado. The convenience sample included adults and children with RT-PCR-confirmed infection who used self-collected home antigen tests for 15 days and underwent at least 1 nasopharyngeal swab for RT-PCR, viral culture, and sequencing. EXPOSURES SARS-CoV-2 infection. MAIN OUTCOMES AND MEASURES The primary outcome was the daily sensitivity of home antigen tests to detect RT-PCR-confirmed cases. Secondary outcomes included the daily percentage of antigen test, RT-PCR, and viral culture results that were positive, and antigen test sensitivity compared with same-day RT-PCR and cultures. Antigen test use errors and acceptability were assessed for a subset of participants. RESULTS This study enrolled 225 persons with RT-PCR-confirmed infection (median [range] age, 29 [1-83] years; 117 female participants [52%]; 10 [4%] Asian, 6 [3%] Black or African American, 50 [22%] Hispanic or Latino, 3 [1%] Native Hawaiian or Other Pacific Islander, 145[64%] White, and 11 [5%] multiracial individuals) who completed 3044 antigen tests and 642 nasopharyngeal swabs. Antigen test sensitivity was 50% (95% CI, 45%-55%) during the infectious period, 64% (95% CI, 56%-70%) compared with same-day RT-PCR, and 84% (95% CI, 75%-90%) compared with same-day cultures. Antigen test sensitivity peaked 4 days after illness onset at 77% (95% CI, 69%-83%). Antigen test sensitivity improved with a second antigen test 1 to 2 days later, particularly early in the infection. Six days after illness onset, antigen test result positivity was 61% (95% CI, 53%-68%). Almost all (216 [96%]) surveyed individuals reported that they would be more likely to get tested for SARS-CoV-2 infection if home antigen tests were available over the counter. CONCLUSIONS AND RELEVANCEThe results of this cohort study of home antigen tests suggest that sensitivity for SARS-CoV-2 was moderate compared with RT-PCR and high compared with viral culture. The results also suggest that symptomatic individuals with an initial negative home antigen test result for SARS-CoV-2 infection should test again 1 to 2 days later because test sensitivity peaked several days after illness onset and improved with repeated testing.

We report here the isolation and identification of the RNA specifically immunoprecipitated and covalently linked to the tumor suppressor gene product p53. After treatment with proteinase K, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) band of p53 yields a single, discrete 157-nucleotide RNA, which was cloned, sequenced, and identified as 5.8S rRNA. 5.8S rRNA was obtained only after proteolysis of the p53 SDS-PAGE band. Free 5.8S rRNA did not comigrate with p53 in SDS-PAGE. This RNA was only immunoprecipitated from cells containing p53. Protein-free RNA obtained by proteolysis of the p53 band hybridized to the single-stranded DNA vector containing the antisense sequence of 5.8S rRNA. The covalence of the p53-5.8S rRNA linkage was demonstrated by the following findings: (i) p53 and the linked 5.8S rRNA comigrated in SDS-PAGE; (ii) only after treatment of the p53-RNA complex with proteinase K did the 5.8S rRNA migrate differently from p53-linked 5.8S rRNA; and (iii) this isolated RNA was found linked to phosphoserine, presumably at the 5' end. Covalent linkage to the single, specific RNA suggests that p53 may be involved in regulating the expression or function of 5.8S rRNA.Inactivation of the tumor suppressor p53 is implicated mechanistically in both human tumorigenesis and the replication of the small DNA viruses. Both of these processes involve the abrogation of normal cellular growth control. Although the molecular mechanism of cell cycle inhibition by p53 has not been worked out, several of its biochemical properties have been demonstrated and can be correlated with specific domains of p53. The amino-terminal third of the molecule is rich in hydrophobic and acidic residues. p53-GAL4 fusion proteins containing the amino terminus of p53 have been shown previously to have transcriptional transactivating activity in vitro (7,25). p53 has also been shown previously to down-regulate various promoters (11). Fur polypeptide. Murine p53 is phosphorylated both at multiple sites at the amino terminus (17, 28) and at Ser-312 and Ser-389 (17,18,28) at the carboxyl terminus.We have previously postulated that p53 is covalently linked to RNA on the basis of our initial observations that Ser-389 is not dephosphorylated by alkaline phosphatase and that the carboxyl-terminal tryptic peptide containing Ser-389 coeluted from reverse-phase high-pressure liquid chromatography with ribonucleotides (28). By using a proteinchemical approach to characterization of the complex, we subsequently showed covalent linkage of p53 to some undefined RNA at the levels of both the tryptic carboxyl-terminal peptide and the intact protein (29). Stable and transient protein-nucleic acid covalent bonds have been described.The genome-linked proteins 4X protein A (27) and adenovirus terminal protein (3) are found covalently linked to DNA, and the poliovirus genome-linked protein, VpG, is covalently linked to RNA (9,15