Optical measurement of gating pore currents in hypokalemic periodic paralysis model cells

Hypokalemic periodic paralysis (HypoPP) is a rare genetic disease associated with mutations in CACNA1S or SCN4A, encoding Cav1.1 or Nav1.4, respectively. Most HypoPP-associated missense changes occur at the arginine residues within the voltage-sensing domain (VSD) of these channels. It is established that such mutations destroy the hydrophobic seal separating the external water and the internal cytosolic crevices, resulting in the generation of aberrant leak currents called gating pore currents. Presently, the gating pore currents are thought to underlie HypoPP. Here, we generated HEK293T-based HypoPP-model cell lines with the Sleeping Beauty transposon system that co-express mouse inward-rectifier potassium channel (mKir2.1) and HypoPP2-associated Nav1.4 variants. Whole cell patch-clamp measurements confirmed that mKir2.1 successfully hyperpolarized the membrane potential to comparable levels to myofibers, and that some Nav1.4 variants induced notable proton-based gating pore currents. Importantly, we succeeded in fluorometrically measuring the gating pore currents in these variants using a ratiometric pH indicator, SNARF-4F. Our optical method provides a potential in vitro platform for high-throughput drug screen, not only for HypoPP but also for other channelopathies caused by VSD mutations.Kubota T., Takahashi S., Yamamoto R., et al. Optical measurement of gating pore currents in hypokalemic periodic paralysis model cells. DMM Disease Models and Mechanisms 16, A18 (2023); https://doi.org/10.1242/dmm.049704

Development of Antimicrobial Peptide–Antibiotic Conjugates to Improve the Outer Membrane Permeability of Antibiotics Against Gram-Negative Bacteria

Antibiotics have been widely used in the medical field as a treatment for infectious diseases, but they are not effective against all Gram-negative bacteria because of their low permeability to the outer membrane. One of the strategies to improve the antibacterial activity of antibiotics is the coadministration of antibiotics and membrane-perturbing antimicrobial peptides for their synergistic effects. However, because of their different pharmacokinetics, their coadministration may not exert expected effects in the clinical stage. Here, we designed various antimicrobial peptide–antibiotic conjugates as a novel approach to improve the antimicrobial activity of antibiotics. Ampicillin was chosen as a model antibiotic with poor outer membrane permeability, and the effects of the chemistry and position of conjugation and the choice of antimicrobial peptides were examined. One of the ampicillin conjugates exhibited significantly improved antimicrobial activity against ampicillin-resistant Gram-negative bacteria without exerting cytotoxicity against human cultured cells, demonstrating that our novel approach is an effective strategy to improve the antimicrobial activity of antibiotics with low outer membrane permeability

Impact of the clinical frailty scale on mid-term mortality in patients with ST-elevated myocardial infarction

Background: “Frailty” is associated with poor prognosis in ST-elevated myocardial infarction (STEMI). However, there is little data regarding the impact of the Canadian Study of Health and Aging Clinical Frailty Scale (CFS), a simple and semiquantitative tool for assessing frailty, on mid-term mortality in STEMI patients. Methods: A total of 354 consecutive STEMI patients (mean age 69.8 ± 12.4 years; male 76.6%) who underwent percutaneous intervention between July 2014 and March 2017 were retrospectively reviewed. The study endpoint was mid-term mortality according to the CFS classification. Furthermore, in order to clarify the impact of CFS upon admission on mid-term mortality, the independent predictors of all-cause death were evaluated. Results: Patients were categorized into three groups (CFS 1–3, n = 281; CFS 4–5, n = 62; and CFS 6–7, n = 11). During the study period (median 474 days), all-cause death was observed in 39 patients. After multivariate Cox regression analysis, higher CFS (adjusted hazard ratio [HR] 2.34, 95% confidence interval [CI] 1.43–3.85, p < 0.001), higher Killip score (adjusted HR 2.46, 95%CI 1.30–5.78, p = 0.002), and lower serum albumin level (adjusted HR 4.29, 95%CI 2.16–8.51, p < 0.001) were significantly associated with an increased risk of all-cause death. Conclusion: In conclusion, severe frailty was associated with mid-term mortality in STEMI patients who underwent PCI. Keywords: Coronary heart disease, ST-elevated myocardial infarction, Frail, Prognosi

In-hospital mortality among consecutive patients with ST-Elevation myocardial infarction in modern primary percutaneous intervention era ~ Insights from 15-year data of single-center hospital-based registry ~.

ObjectiveTo clarify the association of detailed angiographic findings with in-hospital outcome after primary percutaneous coronary intervention (p-PCI) for ST-elevation myocardial infarction (STEMI) in Japan.BackgroundData regarding the association of detailed angiographic findings with in-hospital outcome after STEMI are limited in the p-PCI era.MethodsBetween January-2004 and December-2018, 1735 patients with STEMI (mean age, 68.5 years; female, 24.6%) who presented to the hospital in the 24-hours after symptom onset and underwent p-PCI were evaluated using the disease registries. The registry is an ongoing, retrospective, single-center hospital-based registry.ResultsThe 30-day mortality rate and in-hospital mortality rate were 7.7% and 9.2%, respectively. Independent predictors of in-hospital mortality were ejection fraction (EF) II (aOR, 7.438; p ConclusionsAmong the consecutive patients with STEMI, the in-hospital mortality rate after p-PCI significantly improved in the second half. Not only CKD, Killip class > II, and EF < 40%, but also the angiographic findings such as culprit lesions in the LCA, absence of very robust collaterals, and final TIMI grades <3 were associated with an increased risk of in-hospital mortality

Empagliflozin in Patients with Chronic Kidney Disease

Background The effects of empagliflozin in patients with chronic kidney disease who are at risk for disease progression are not well understood. The EMPA-KIDNEY trial was designed to assess the effects of treatment with empagliflozin in a broad range of such patients. Methods We enrolled patients with chronic kidney disease who had an estimated glomerular filtration rate (eGFR) of at least 20 but less than 45 ml per minute per 1.73 m(2) of body-surface area, or who had an eGFR of at least 45 but less than 90 ml per minute per 1.73 m(2) with a urinary albumin-to-creatinine ratio (with albumin measured in milligrams and creatinine measured in grams) of at least 200. Patients were randomly assigned to receive empagliflozin (10 mg once daily) or matching placebo. The primary outcome was a composite of progression of kidney disease (defined as end-stage kidney disease, a sustained decrease in eGFR to &lt; 10 ml per minute per 1.73 m(2), a sustained decrease in eGFR of &amp; GE;40% from baseline, or death from renal causes) or death from cardiovascular causes. Results A total of 6609 patients underwent randomization. During a median of 2.0 years of follow-up, progression of kidney disease or death from cardiovascular causes occurred in 432 of 3304 patients (13.1%) in the empagliflozin group and in 558 of 3305 patients (16.9%) in the placebo group (hazard ratio, 0.72; 95% confidence interval [CI], 0.64 to 0.82; P &lt; 0.001). Results were consistent among patients with or without diabetes and across subgroups defined according to eGFR ranges. The rate of hospitalization from any cause was lower in the empagliflozin group than in the placebo group (hazard ratio, 0.86; 95% CI, 0.78 to 0.95; P=0.003), but there were no significant between-group differences with respect to the composite outcome of hospitalization for heart failure or death from cardiovascular causes (which occurred in 4.0% in the empagliflozin group and 4.6% in the placebo group) or death from any cause (in 4.5% and 5.1%, respectively). The rates of serious adverse events were similar in the two groups. Conclusions Among a wide range of patients with chronic kidney disease who were at risk for disease progression, empagliflozin therapy led to a lower risk of progression of kidney disease or death from cardiovascular causes than placebo