Probing the SAM Binding Site of SARS-CoV-2 nsp14 in vitro Using SAM Competitive Inhibitors Guides Developing Selective bi-substrate Inhibitors

The COVID-19 pandemic has clearly brought the healthcare systems world-wide to a breaking point along with devastating socioeconomic consequences. The SARS-CoV-2 virus which causes the disease uses RNA capping to evade the human immune system. Non-structural protein (nsp) 14 is one of the 16 nsps in SARS-CoV-2 and catalyzes the methylation of the viral RNA at N7-guanosine in the cap formation process. To discover small molecule inhibitors of nsp14 methyltransferase (MT) activity, we developed and employed a radiometric MT assay to screen a library of 161 in house synthesized S-adenosylmethionine (SAM) competitive methyltransferase inhibitors and SAM analogs. Among seven identified screening hits, SS148 inhibited nsp14 MT activity with an IC50 value of 70 ± 6 nM and was selective against 20 human protein lysine methyltransferases indicating significant differences in SAM binding sites. Interestingly, DS0464 with IC50 value of 1.1 ± 0.2 μM showed a bi-substrate competitive inhibitor mechanism of action. Modeling the binding of this compound to nsp14 suggests that the terminal phenyl group extends into the RNA binding site. DS0464 was also selective against 28 out of 33 RNA, DNA, and protein methyltransferases. The structure-activity relationship provided by these compounds should guide the optimization of selective bi-substrate nsp14 inhibitors and may provide a path towards a novel class of antivirals against COVID-19, and possibly other coronaviruses

Tissue eosinophilia: a morphologic marker for assessing stromal invasion in laryngeal squamous neoplasms

BACKGROUND: The assessment of tumor invasion of underlying benign stroma in neoplastic squamous proliferation of the larynx may pose a diagnostic challenge, particularly in small biopsy specimens that are frequently tangentially sectioned. We studied whether thresholds of an eosinophilic response to laryngeal squamous neoplasms provides an adjunctive histologic criterion for determining the presence of invasion. METHODS: Eighty-seven(n = 87) cases of invasive squamous cell carcinoma and preinvasive squamous neoplasia were evaluated. In each case, the number of eosinophils per high power field(eosinophils/hpf), and per 10 hpf in the tissue adjacent to the neoplastic epithelium, were counted and tabulated. For statistical purposes, the elevated eosinophils were defined and categorized as: focally and moderately elevated (5–9 eos/hpf), focally and markedly increased(>10/hpf), diffusely and moderately elevated(5–19 eos/10hpf), and diffusely and markedly increased (>20/10hpf). RESULTS: In the invasive carcinoma, eosinophil counts were elevated focally and /or diffusely, more frequently seen than in non-invasive neoplastic lesions. The increased eosinophil counts, specifically >10hpf, and >20/10hpf, were all statistically significantly associated with stromal invasion. Greater than 10 eosinophils/hpf and/or >20 eosinophils/10hpf had highest predictive power, with a sensitivity, specificity and positive predictive value of 82%, 93%, 96% and 80%, 100% and 100%, respectively. Virtually, greater than 20 eosinophils/10 hpf was diagnostic for tumor invasion in our series. CONCLUSION: Our study suggests for the first time that the elevated eosinophil count in squamous neoplasia of the larynx is a morphologic feature associated with tumor invasion. When the number of infiltrating eosinophils exceeds 10/hpf and or >20/10 hpf in a laryngeal biopsy with squamous neoplasia, it represents an indicator for the possibility of tumor invasion. Similarly, the presence of eosinophils meeting these thresholds in an excisional specimen should prompt a thorough evaluation for invasiveness, when evidence of invasion is absent, or when invasion is suspected by conventional criteria in the initial sections

Critical policy frontiers: the drugs-development-peacebuilding trilemma

Recent years have seen the emergence of a policy consensus around the need for fundamental reforms of global drug policies. This is reflected in the call for ‘development-oriented drug policies’ that align and integrate drug policies with development and peacebuilding objectives, as captured in the Sustainable Development Goals (SDGs). These calls have been important in acknowledging the damage caused by the war on drugs and in drawing attention to how drugs are inextricably linked to wider development and peacebuilding challenges. Yet there is surprisingly limited academic research that looks critically at the drugs-development-peace nexus and which asks whether the goals of a ‘drug-free world’, ‘sustainable development’ and ‘the promotion of peace’ are commensurate with one another, can be pursued simultaneously, or are indeed achievable. This article studies these policy fields and policy-making processes from the geographical margins of the state – frontiers and borderland regions – because they offer a privileged vantage point for studying the contested nature of policymaking in relation to the drugs-development-peace nexus. We set out a historical political economy framework to critically assess the assumptions underlying the integrationist agenda, as well as the evidence base to support it. By developing the notion of a policy trilemma we are critical of the dominant policy narrative that ‘all good things come together’, showing instead the fundamental tensions and trade-offs between these policy fields. In exploring the interactions between these policy fields, we aim to advance discussion and debate on how to engage with the tensions and trade-offs that this integrationist agenda reveals, but which have to date been largely ignored

Perinatal outcome in singleton pregnancies complicated with preeclampsia and eclampsia in Ecuador

Preeclampsia in Ecuador is an understudied subject since available epidemiological data are scarce. The aim of this study was to describe perinatal outcomes among singleton pregnancies complicated with preeclampsia and eclampsia in a sample of low-income Ecuadorian women. Pregnant women complicated with preeclampsia (mild and severe) and eclampsia (defined according to criteria of the ACOG) delivering at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital, Guayaquil, Ecuador were surveyed with a structured questionnaire containing maternal (socio-demographic) and neonatal data. Perinatal outcomes were compared according to severity of clinical presentation. A total of 163 women with preeclampsia [mild (23.9%), severe (68.7%) and eclampsia (7.4%)] were surveyed. Perinatal mortality and stillbirth rate was similar among studied groups (mild vs. severe preeclampsia/eclampsia cases). However, severe cases displayed higher rates of adverse perinatal outcomes: lower birth Apgar scores, more preterm births, and more low birth weight and small for gestational age infants. Caesarean-section rate and the number of admissions to intensive or intermediate neonatal care were higher in severe cases. A similar trend was found when analysis excluded preterm gestations. In conclusion, in this specific low-income Ecuadorian population perinatal outcome was adverse in pregnancies complicated with severe preeclampsia/eclampsi