We recently demonstrated the utility of quantifying spontaneous pain in mice via the blinded coding of facial expressions. As the majority of preclinical pain research is in fact performed in the laboratory rat, we attempted to modify the scale for use in this species. We present herein the Rat Grimace Scale, and show its reliability, accuracy, and ability to quantify the time course of spontaneous pain in the intraplantar complete Freund's adjuvant, intraarticular kaolin-carrageenan, and laparotomy (post-operative pain) assays. The scale's ability to demonstrate the dose-dependent analgesic efficacy of morphine is also shown. In addition, we have developed software, Rodent Face Finder®, which successfully automates the most labor-intensive step in the process. Given the known mechanistic dissociations between spontaneous and evoked pain, and the primacy of the former as a clinical problem, we believe that widespread adoption of spontaneous pain measures such as the Rat Grimace Scale might lead to more successful translation of basic science findings into clinical application.

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Aims Identification and intervention of left ventricular hypertrophy (LVH) in essential hypertension (EH) are important for the prevention of adverse cardiovascular events. However, effective methods for diagnosing LVH are still lacking. This study aimed to explore the relationship between soluble ST2 (sST2) and LVH in EH patients to identify a potential specific biomarker for hypertensive LVH. Methods and results This study included 97 EH patients. Based on the criteria for LVH, participants were divided into the LVH group ( n = 52) and the non‐LVH group ( n = 45). The level of serum sST2 was detected by enzyme‐linked immunosorbent assay. Pearson correlation analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis were used to investigate the potential of sST2 as a biomarker of LVH in EH patients. Compared with the non‐LVH group, the sST2 level was elevated in EH patients with LVH ( P < 0.001). Pearson correlation analysis indicated that the sST2 level was positively correlated with the left ventricular mass index in EH patients ( r = 0.454, P < 0.001). Logistic regression analysis showed that the odds ratio (OR) value of LVH was 2.990, suggesting that sST2 is an independent risk factor for LVH in EH patients [OR = 2.990, 95% confidence interval (CI), 1.650–5.419; P < 0.001]. The area under the ROC curve was 0.767 (95% CI, 0.669–0.866; P < 0.001), with a sensitivity of 0.808 and specificity of 0.689, indicating the possibility of considering sST2 as a biomarker for diagnosing LVH. Conclusions Up‐regulation of sST2 is strongly related to LVH in EH patients, is an independent risk factor for hypertensive LVH, and can be used as a biomarker for the diagnosis of LVH.

The binding of the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein onto human angiotensin-converting enzyme 2 (ACE2) is considered as the first step for the virus to adhere onto the host cells during the infection. Here, we investigated the adhesion of spike proteins from different variants and ACE2 using single-molecule and single-cell force spectroscopy. We found that the unbinding force and binding probability of the spike protein from Delta variant to the ACE2 were the highest among the variants tested in our study at both single-molecule and single-cell levels. As the most popular variants, the Omicron variants have slightly higher unbinding force to the ACE2 than wild type. Molecular dynamics simulation showed that ACE2-RBD (Omicron BA.1) complex is destabilized by the E484A and Y505H mutations and stabilized by S477N and N501Y mutations, when compared with Delta variant. In addition, a neutralizing antibody, produced by immunization with wild type spike protein, could effectively inhibit the binding of spike proteins from wild type, Delta and Omicron variants (BA.1 and BA.5) onto ACE2. Our results provide new insight for the molecular mechanism of the adhesive interactions between spike protein and ACE2 and suggest that effective monoclonal antibody can be prepared using wild type spike protein against different variants.