Infection by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) causes a wide spectrum of syndromes involving multiple organ systems and is primarily mediated by viral spike (S) ...glycoprotein through the receptor‐binding domain (RBD) and numerous cellular proteins including ACE2, transmembrane serine protease 2 (TMPRSS2), kidney injury molecule‐1 (Kim‐1), and neuropilin‐1 (NRP‐1). In this study, we examined the entry tropism of SARS‐CoV‐2 and SARS‐CoV using S protein‐based pseudoviruses to infect 22 cell lines and 3 types of primary cells isolated from respiratory, urinary, digestive, reproductive, and immune systems. At least one cell line or type of primary cell from each organ system was infected by both pseudoviruses. Infection by pseudoviruses is effectively blocked by S1, RBD, and ACE2 recombinant proteins, and more weakly by Kim‐1 and NRP‐1 recombinant proteins. Furthermore, cells with robust SARS‐CoV‐2 pseudovirus infection had strong expression of either ACE2 or Kim‐1 and NRP‐1 proteins. ACE2 glycosylation appeared to be critical for the infections of both viruses as there was a positive correlation between infectivity of either SARS‐CoV‐2 or SARS‐CoV pseudovirus with the level of glycosylated ACE2 (gly‐ACE2). These results reveal that SARS‐CoV‐2 cell entry could be mediated by either an ACE2‐dependent or ‐independent mechanism, thus providing a likely molecular basis for its broad tropism for a wide variety of cell types.
"Compassion and mercy" are important values for humanizing medicine. There are limits, however, in their ability to help resolve disputes between physicians and families regarding appropriate ...end-of-life care. The recent cases of Charlie Gard and Alfie Evans in England highlight the issue. The English courts resolve such conflicts by an independent assessment of a court. The American judicial system does not share the centralized system of the English courts. In the United States Federal structure some 50 state legislatures and 50 state court systems go their separate ways. The result is differing, frequently conflicting, standards. We explore possible ways to avoid court involvement in the American context for resolving such disputes within the patient-physician relationship.
Purpose
To investigate the attitudes and understanding of optometrists in the UK and Ireland towards Digital Eye Strain (DES), and to examine related practice patterns.
Methods
An anonymous online ...questionnaire was developed, covering attitude and understanding of DES, examination of patients who may be experiencing DES and approaches to management options. The questionnaire was promoted to UK and Ireland optometrists via professional bodies and local and area optometric committees.
Results
406 responses were included in the analysis. Most respondents agreed that DES was an important concern for optometrists (88.9%). 91.4% reported they felt confident in discussing possible symptoms of DES and management options; this was weakly and negatively associated with number of years qualified (rs = −0.198, p ≤ 0.001). Estimations of the proportion of patients affected by DES were lower than reports in the literature (median 25%, IQR 10%–50%). Most respondents always (60.6%) or frequently (21.9%) inquired about device usage in routine case history taking, and also asked follow‐up questions, although 29.3% only asked about the presence of symptoms half the time or less. Advising on regular breaks (84.0%), lubricants (55.7%) and environment/set up (69.2%) were felt to be extremely or very important by most respondents. Advising on specialist spectacle lenses, specifically blue filtering designs, was considered extremely or very important by 34.2% and 15.2%, respectively.
Conclusion
Given the agreement that DES is a significant issue causing frequent and persistent symptoms, and practitioners reported high levels of confidence in discussing DES, patients can expect to receive advice on symptoms and management from their optometrist. Simple management strategies were felt to be most important to advise on, with more uncertainty linked to specialist spectacle lenses.
Fanconi anemia is a rare genome instability disorder with extreme susceptibility to squamous cell carcinoma of the head and neck and anogenital tract. In patients with this inherited disorder, the ...risk of head and neck cancer is 800-fold higher than in the general population, a finding which might suggest a viral etiology. Here, we analyzed the possible contribution of human polyomaviruses to FA-associated head and neck squamous cell carcinoma (HNSCC) by a pan-polyomavirus immunohistochemistry test which detects the T antigens of all known human polyomaviruses. We observed weak reactivity in 17% of the HNSCC samples suggesting that based on classical criteria, human polyomaviruses are not causally related to squamous cell carcinomas analyzed in this study.
Merkel cell polyomavirus (MCV) causes ~80% of primary and metastatic Merkel cell carcinomas (MCCs). By comparing digital transcriptome subtraction deep-sequencing profiles, we found that transcripts ...of the cellular survivin oncoprotein BIRC5a (baculoviral inhibitor of apoptosis repeat-containing 5) were up-regulated sevenfold in virus-positive compared to virus-negative MCC tumors. Knockdown of MCV large T antigen in MCV-positive MCC cell lines decreased survivin mRNA and protein expression. Exogenously expressed MCV large T antigen increased survivin protein expression in non-MCC primary cells. This required an intact retinoblastoma protein-targeting domain that activated survivin gene transcription as well as expression of other G(1)-S-phase proteins including E2F1 and cyclin E. Survivin expression is critical to the survival of MCV-positive MCC cells. A small-molecule survivin inhibitor, YM155, potently and selectively initiates irreversible, nonapoptotic, programmed MCV-positive MCC cell death. Of 1360 other chemotherapeutic and pharmacologically active compounds screened in vitro, only bortezomib (Velcade) was found to be similarly potent, but was not selective in killing MCV-positive MCC cells. YM155 halted the growth of MCV-positive MCC xenograft tumors and was nontoxic in mice, whereas bortezomib was not active in vivo and mice displayed serious morbidity. Xenograft tumors resumed growth once YM155 treatment was stopped, suggesting that YM155 may be cytostatic rather than cytotoxic in vivo. Identifying the cellular pathways, such as those involving survivin, that are targeted by tumor viruses can lead to rapid and rational identification of drug candidates for treating virus-induced cancers.
Merkel cell polyomavirus (MCV) causes one of the most aggressive human skin cancers, but laboratory studies on MCV replication have proven technically difficult. We report the first ...recombinase-mediated MCV minicircle (MCVmc) system that generates high levels of circularized virus, allowing facile MCV genetic manipulation and characterization of viral gene expression kinetics during replication. Mutations to Fbw7, Skp2, β-TrCP and hVam6p interaction sites, or to the stem loop sequence for the MCV-encoded miRNA precursor, markedly increase viral replication, whereas point mutation to an origin-binding site eliminates active virus replication. To further increase the utility of this system, an mScarlet fusion protein was inserted into the VP1 c-terminus to generate a non-infectious reporter virus for studies on virus kinetics. When this reporter virus genome is heterologously expressed together with MCV VP1 and VP2, virus-like particles are generated. The reporter virus genome is encapsidated and can be used at lower biosafety levels for one-round infection studies. Our findings reveal that MCV has multiple, self-encoded viral restriction mechanisms to promote viral latency over lytic replication, and these mechanisms are now amenable to examination using a recombinase technology.
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