Sensitive bacterial Vm sensors revealed the excitability of bacterial Vm and its role in antibiotic tolerance.

As an important free energy source, the membrane voltage (Vm) regulates many essential physiological processes in bacteria. However, in comparison with eukaryotic cells, knowledge of bacterial electrophysiology is very limited. Here, we developed a set of novel genetically encoded bacterial Vm sensors which allow single-cell recording of bacterial Vm dynamics in live cells with high temporal resolution. Using these new sensors, we reveal the electrically "excitable" and "resting" states of bacterial cells dependent on their metabolic status. In the electrically excitable state, frequent hyperpolarization spikes in bacterial Vm are observed, which are regulated by Na+/K+ ratio of the medium and facilitate increased antibiotic tolerance. In the electrically resting state, bacterial Vm displays significant cell-to-cell heterogeneity and is linked to the cell fate after antibiotic treatment. Our findings demonstrate the potential of our newly developed voltage sensors to reveal the underpinning connections between bacterial Vm and antibiotic tolerance.

Permanent vs Transient Congenital Hypothyroidism in Chinese Children: Physical Growth and Predictive Nomogram.

CONTEXT: Few reliable markers are available to distinguish transient congenital hypothyroidism (TCH) and permanent congenital hypothyroidism (PCH). Additionally, the differences in growth between TCH and PCH remain unclear. OBJECTIVE: To investigate the growth of children with TCH and PCH and develop a nomogram for early differentiation of these forms. METHODS: This retrospective study included children with TCH or PCH. The predictive efficacy of the prognostic predictors was analyzed using receiver operating characteristic analysis. Multivariate prediction models were developed. Measurements of growth were compared between groups. RESULTS: Patients with TCH had lower initial thyroid-stimulating hormone (TSH) than those with PCH at newborn screening (NBS). The supplementary dose of levothyroxine (L-T4) gradually decreased with age in TCH but not in PCH. The area under the curve (AUC) values of the initial TSH, L-T4 dose at 1 year of age, and L-T4 dose at 2 years of age for distinguishing TCH from PCH were 0.698, 0.71, and 0.879, respectively. The predictive efficacy of the multivariate models at 1 and 2 years of age improved, with AUC values of 0.752 and 0.922, respectively. A nomogram was built based on the multivariate model at 1 year of age. The growth did not differ between children with TCH and those with PCH. However, at 1 year of age, girls with CH exhibited higher z-scores in terms of height and weight than boys with CH. CONCLUSION: TSH at NBS and L-T4 doses during treatment can be used to distinguish between PCH and TCH early in life, and the predictive efficacy can be improved using multivariable models with a visualized nomogram. At 3 years of age, patients with TCH and PCH showed similar growth.

A benzothiazole-based fluorescent probe for hypochlorous acid detection and imaging in living cells.

A benzothiazole-based turn-on fluorescent probe with a large Stokes shift (190nm) has been developed for hypochlorous acid detection. The probe displays prompt fluorescence response for HClO with excellent selectivity over other reactive oxygen species as well as a low detection limit of 0.08µM. The sensing mechanism involves the HClO-induced specific oxidation of oxime moiety of the probe to nitrile oxide, which was confirmed by HPLC-MS technique. Furthermore, imaging studies demonstrated that the probe is cell permeable and can be applied to detect HClO in living cells.