Continuous positive airway pressure treatment from the prehospital field in a Japanese regional Doctor Car system.

Background: Continuous positive airway pressure (CPAP) therapy is an effective treatment for patients with severe heart failure, and certain guidelines recommend its early initiation. However, the current Japanese law strictly prohibits paramedics from administering this treatment. To demonstrate the efficacy and safety of prehospital administration of CPAP therapy, this study was conducted by the Yokohama Medical Control Council (Yokohama MC). Methods: The Yokohama MC established a protocol for CPAP treatment and dispatched Doctor Cars to attend to patients with severe respiratory failure. The Boussignac CPAP system was installed in all Yokohama Doctor Cars, including Workstation-type Doctor Cars and Hospital-type Doctor Cars. Data from this study were collected and recorded in the Yokohama City Doctor Car Registry system from October 2020 to January 2022. Results: The Doctor Car was dispatched 661 times, and CPAP therapy was administered to 13 patients in the prehospital field. It is important to note that the number of CPAP cases was lower than anticipated due to the coronavirus disease 2019 (COVID-19) pandemic, given concerns about aerosol production. When assessing changes over time in oxygen saturation (SpO2), the median (interquartile range), excluding missing values, was 89% (83%-93%) without oxygen, 95% (94%-99.3%) with oxygen, and 100% (97%-100%) with CPAP. The differences between these groups were statistically significant with a p-value of <0.0001. Respiratory distress was primarily attributed to heart failure in 10 patients (91%) and pneumothorax in 1 patient (9%). Notably, none of the patients' conditions worsened after the use of CPAP. Conclusion: We have detailed the administration of CPAP therapy in the prehospital field within a local city in Japan. To the best of our knowledge, this represents the inaugural report of a prospective observational study on the prehospital administration of CPAP therapy originating from Japan.

Assembly Domain-Based Optogenetic System for the Efficient Control of Cellular Signaling.

We previously developed the Magnet system, which consists of two distinct Vivid protein variants, one positively and one negatively charged, designated the positive Magnet (pMag) and negative Magnet (nMag), respectively. These two proteins bind to each other through electrostatic interactions, preventing unwanted homodimerization and providing selective light-induced heterodimerization. The Magnet system enables the manipulation of cellular functions such as protein-protein interactions and genome editing, although the system could be improved further. To enhance the ability of pMagFast2 (a pMag variant with fast kinetics) to bind nMag, we introduced several pMagFast2 modules in tandem into a single construct, pMagFast2(3×). However, the expression level of this construct decreased drastically with increasing number of pMagFast2 molecules integrated into a single construct. In the present study, we applied a new approach to improve the Magnet system based on an assembly domain (AD). Among several ADs, the Ca2+/calmodulin-dependent protein kinase IIα association domain (CAD) most enhanced the Magnet system. The present CAD-Magnet system overcame a trade-off issue between the expression level and binding affinity. The CAD-converged 12 pMag photoswitches exhibited a stronger interaction with nMag after blue light irradiation compared with monomeric pMag. Additionally, the CAD played a key role in converging effector proteins as well in a single complex. Owing to these substantial improvements, the CAD-Magnet system combined with Tiam1 allowed us to robustly induce localized formation of vertical ruffles on the apical plasma membrane. The CAD-Magnet system combined with 4D imaging was instrumental in revealing the dynamics of ruffle formation.

Optical manipulation of the alpha subunits of heterotrimeric G proteins using photoswitchable dimerization systems.

Alpha subunits of heterotrimeric G proteins (Gα) are involved in a variety of cellular functions. Here we report an optogenetic strategy to spatially and temporally manipulate Gα in living cells. More specifically, we applied the blue light-induced dimerization system, known as the Magnet system, and an alternative red light-induced dimerization system consisting of Arabidopsis thaliana phytochrome B (PhyB) and phytochrome-interacting factor 6 (PIF6) to optically control the activation of two different classes of Gα (Gαq and Gαs). By utilizing this strategy, we demonstrate successful regulation of Ca2+ and cAMP using light in mammalian cells. The present strategy is generally applicable to different kinds of Gα and could contribute to expanding possibilities of spatiotemporal regulation of Gα in mammalian cells.

Engineered pairs of distinct photoswitches for optogenetic control of cellular proteins.

Optogenetic methods take advantage of photoswitches to control the activity of cellular proteins. Here, we completed a multi-directional engineering of the fungal photoreceptor Vivid to develop pairs of distinct photoswitches named Magnets. These new photoswitches were engineered to recognize each other based on the electrostatic interactions, thus preventing homodimerization and enhancing light-induced heterodimerization. Furthermore, we tuned the switch-off kinetics by four orders of magnitude and developed several variants, including those with substantially faster kinetics than any of the other conventional dimerization-based blue spectrum photoswitches. We demonstrate the utility of Magnets as powerful tools that can optogenetically manipulate molecular processes in biological systems.