Improvement of Phycocyanobilin Synthesis for Genetically Encoded Phytochrome-Based Optogenetics

Optogenetics is a powerful technique using photoresponsive proteins, and the light-inducible dimerization (LID) system, an optogenetic tool, allows to manipulate intracellular signaling pathways. One of the red/far-red responsive LID systems, phytochrome B (PhyB)-phytochrome interacting factor (PIF), has a unique property of controlling both association and dissociation by light on the second time scale, but PhyB requires a linear tetrapyrrole chromophore such as phycocyanobilin (PCB), and such chromophores are present only in higher plants and cyanobacteria. Here, we report that we further improved our previously developed PCB synthesis system (SynPCB) and successfully established a stable cell line containing a genetically encoded PhyB-PIF LID system. First, four genes responsible for PCB synthesis, namely, PcyA, HO1, Fd, and Fnr, were replaced with their counterparts derived from thermophilic cyanobacteria. Second, Fnr was truncated, followed by fusion with Fd to generate a chimeric protein, tFnr-Fd. Third, these genes were concatenated with P2A peptide cDNAs for polycistronic expression, resulting in an approximately 4-fold increase in PCB synthesis compared with the previous version. Finally, we incorporated the PhyB, PIF, and SynPCB system into drug inducible lentiviral and transposon vectors, which enabled us to induce PCB synthesis and the PhyB-PIF LID system by doxycycline treatment. These tools provide a new opportunity to advance our understanding of the causal relationship between intracellular signaling and cellular functions.

Effect of chest-compression-only bystander cardiopulmonary resuscitation on the likelihood of initial shockable rhythm after out-of-hospital cardiac arrest: a propensity matching analysis

Background/Introduction

Shockable rhythm after cardiac arrest is highly expected after early initiation of bystander cardiopulmonary resuscitation (CPR) owing to increased coronary perfusion. However, the relationship between bystander CPR and initial shockable rhythm in patients with out-of-hospital cardiac arrest (OHCA) remains unclear. We hypothesized that chest-compression-only CPR (CC-CPR) before emergency medical service (EMS) arrival has an equivalent effect on the likelihood of initial shockable rhythm to the standard CPR (chest compression plus rescue breathing [S-CPR]).

Purpose

We aimed to examine the rate of initial shockable rhythm and 1-month outcomes in patients who received bystander CPR after OHCA.

Methods

The study included 59,688 patients (age, ≥18 years) who received bystander CPR after an OHCA with a presumed cardiac origin witnessed by a layperson in a prospectively recorded Japanese nationwide Utstein-style database from 2013 to 2017. Patients who received public-access defibrillation before arrival of the EMS personnel were excluded. The patients were divided into CC-CPR (n=51,520) and S-CPR (n=8168) groups according to the type of bystander CPR received. The primary end point was initial shockable rhythm recorded by the EMS personnel just after arrival at the site. The secondary end point was the 1-month outcomes (survival and neurologically intact survival) after OHCA. In the statistical analyses, a Cox proportional hazards model was applied to reflect the different bystander CPR durations before/after propensity score (PS) matching.

Results

The crude rate of the initial shockable rhythm in the CC-CPR group (21.3%, 10,946/51,520) was significantly higher than that in the S-CPR group (17.6%, 1441/8168, p<0.0001) before PS matching. However, no significant difference in the rate of initial shockable rhythm was found between the 2 groups after PS matching (18.3% [1493/8168] vs 17.6% [1441/8168], p=0.30). In the Cox proportional hazards model, CC-CPR was more negatively associated with the initial shockable rhythm before PS matching (unadjusted hazards ratio [HR], 0.97; 95% confidence interval [CI], 0.94–0.99; p=0.012; adjusted HR, 0.92; 95% CI, 0.89–0.94; p<0.0001) than S-CPR. After PS matching, however, no significant difference was found between the 2 groups (adjusted HR of CC-CPR compared with S-CPR, 0.97; 95% CI, 0.94–1.00; p=0.09). No significant differences were found between C-CPR and S-CPR in the 1-month outcomes after PS matching as follows, respectively: survival, 8.5% and 10.1%; adjusted odds ratio, 0.89; 95% CI, 0.79–1.00; p=0.07; cerebral performance category 1 or 2, 5.5% and 6.9%; adjusted odds, 0.86; 95% CI, 0.74–1.00; p=0.052.

Conclusions

Compared with S-CPR, the CC-CPR before EMS arrival had an equivalent multivariable-adjusted association with the likelihood of initial shockable rhythm in the patients with OHCA due to presumed cardiac causes that was witnessed by a layperson.

Funding Acknowledgement

Type of funding source: None

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Transverse Single-Spin Asymmetry for Very Forward Neutral Pion Production in Polarized p+p Collisions at sqrt[s]=510 GeV

Transverse single-spin asymmetries of very forward neutral pions generated in polarized p+p collisions allow us to understand the production mechanism in terms of perturbative and nonperturbative strong interactions. During 2017, the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized p+p collisions at sqrt[s]=510  GeV. The large nonzero asymmetries increasing both in longitudinal momentum fraction x_{F} and transverse momentum p_{T} have been observed at low transverse momentum p_{T}<1  GeV/c for the first time, at this collision energy. The asymmetries show an approximate x_{F} scaling in the p_{T} region where nonperturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.

P492Estimation of no-flow duration and survival in patients with an initial shockable rhythm after out-of-hospital cardiac arrest

Funding Acknowledgements

Japan Society for the Promotion of Science (KAKENHI Grant No. 18K09999)

Background

In patients with unwitnessed out-of-hospital cardiac arrest (OHCA), the actual no-flow duration (the time with no organ perfusion) is unclear. However, when these patients have a shockable rhythm as an initial recorded rhythm, the no-flow duration may be relatively short as compared with other initial rhythms, and some patients can obtain a good functional outcome after OHCA.

Purpose

The purpose of the present study was to estimate the no-flow duration and to determine the relationship between no-flow duration and neurologically intact survival in patients with an initial shockable rhythm after OHCA.

Methods

We reviewed 82,464 patients with OHCA (aged ≥18 years, non-traumatic, witnessed, and without any bystander interventions) who were included in the All-Japan Utstein-style registry from 2013 to 2017. The study end point was 1-month neurologically intact survival (Cerebral Performance Category scale 1 or 2). No-flow duration was defined as the time from emergency call to emergency medical services (EMS) arrival at the patient site.

Results

The rate of 1-month neurologically intact survival in the patients with an initial shockable rhythm (n = 10,384, 12.6% of overall patients) was 16.5% (1718/10,384). No-flow duration was significantly and inversely associated with 1-month neurologically intact survival (adjusted odds ratios for 1-minute increments: 0.85, 95% confidence interval: 0.84–0.86). The proportion of patients with a shockable rhythm to the overall patients (y, %) had a high correlational relationship with no-flow duration (x, min), depicted by y = 21.0 - 0.95 × x, R² = 0.935. In this analytical model, the number of patients with shockable rhythm reached null at 22 minutes of no-flow duration. The no-flow durations, beyond which the chance for initial shockable rhythm diminished to &lt;10%, &lt;5%, and &lt;1%, were 12, 13, and 17 minutes, respectively. The rate of neurologically intact survival in the patients with shockable rhythm (y, %) and no-flow duration (x, min) were also found to have a strong correlation, depicted by y = 0.16 × x² - 5.12 × x + 45.0, R² = 0.907. The no-flow durations, beyond which the chance for 1-month neurologically intact survival diminished to &lt;10%, &lt;5%, and &lt;1%, were 10, 11, and 15 minutes, respectively.

Conclusions

In OHCA patients without any bystander interventions before EMS personnel arrival, when a shockable rhythm is recorded by EMS personnel as an initial rhythm, the no-flow duration after cardiac arrest is highly likely to be &lt;17 minutes regardless of the layperson witness status. The limitation of no-flow duration to obtain a 1-month neurologically intact survival after OHCA may be 15 minutes when the patients have an initial shockable rhythm.

P498External validation of a field termination-of-resuscitation rule for refractory out-of-hospital cardiac arrests in Japan

Background

A universal basic life support termination-of-resuscitation (BLS-TOR) rule was developed to identify patients with out-of-hospital cardiac arrest (OHCA) eligible for field termination of cardiopulmonary resuscitation (CPR). In Japan, however, emergency medical service (EMS) providers are not allowed field termination of CPR and must transport all patients with OHCA to hospitals, regardless of return of spontaneous circulation (ROSC). Therefore, we previously developed a Japanese TOR (JP-TOR) rule in the field for refractory OHCAs using data from the All-Japan Utstein registry between 2011 and 2015, when CPR was performed according to the 2010 guidelines. The JP-TOR rule recommends CPR termination when patients meet all the following criteria: initial asystole, unwitnessed arrest, age ≥81 years, no bystander interventions before EMS arrival, and no ROSC after EMS-initiated CPR for 14 min.

Purpose

To validate the JP-TOR rule using more recent data where CPR was performed according to the 2015 guidelines, comparing the relevance of JP-TOR rule with the BLS-TOR rule, which consists of the following criteria: no prehospital ROSC after 6-min EMS-initiated CPR, arrest unwitnessed by EMS providers, and no shock received.

Methods

We analysed the records of 242,184 patients (age ≥18 years) who experienced OHCA treated by EMS providers. Data were obtained from a prospectively recorded Japanese nationwide Utstein-style database from 2016 to 2017. The primary endpoints were specificity and positive predictive value (PPV) for predicting the 1-month mortality after OHCA with the JP-TOR and BLS-TOR rules.

Results

The overall 1-month survival rate was 5.3% (12,847/242,184). The proportions of patients with OHCA fulfilled the JP-TOR and BLS-TOR criteria were 10.4% and 89.3%, respectively. The specificity and PPV of the JP-TOR and BLS-TOR rules for predicting 1-month mortality were 99.5% (95% confidence interval [CI], 99.4%–99.5%) and 99.8% (95% CI, 99.7%–99.8%) and 44.7% (95% CI, 43.8%–45.5%) and 96.7% (95% CI, 96.6%–96.8%), respectively.

Conclusions

The JP-TOR rule for EMS providers treating patients with OHCA in the field was successfully validated using more recent data from a Japanese registry where CPR was performed according to the 2015 guidelines. The JP-TOR rule was superior to the BLS-TOR rule in Japanese EMS systems, having both high specificity and PPV of &gt;99% for predicting 1-month mortality. The JP-TOR rule may help EMS providers decide whether to terminate resuscitation efforts for unresuscitable patients with OHCA in the field. Prospective validation studies and establishment of prehospital EMS protocol are required before implementing this rule in Japan.

P489Survival in children with out-of-hospital cardiac arrest after standard or chest compression-only bystander cardiopulmonary resuscitation before emergency medical services arrival

Funding Acknowledgements

Japan Society for the Promotion of Science (KAKENHI Grant No. 18K09999)

Background

For out-of-hospital cardiac arrest (OHCA), current cardiopulmonary resuscitation (CPR) guidelines recommend chest compression-only bystander CPR (C- BCPR) for both untrained and trained bystanders unwilling to perform rescue breaths before emergency medical services personnel arrival. However, during 3 consecutive guideline periods, changes in type of BCPR and neurologically intact survival rate are unclear in paediatric OHCA cases.

Purpose

We aimed to determine the change in the rate and type of BCPR in correlation to the 1-month neurologically intact survival and causes of OHCA.

Methods

We reviewed 5461 children with bystander witnessed OHCA included in the All-Japan Utstein-style registry from 2005 to 2017. Patients were divided into 3 groups according to the type of BCPR: no BCPR (NO-BCPR), standard BCPR with rescue breaths (S-BCPR), and C-BCPR. Guideline periods 2005 to 2010 (pre-G2010), 2011 to 2015 (G2010), and 2016 to 2017 (G2015) were used for comparison over time. The study endpoint was 1-month neurologically intact survival (Cerebral Performance Category [CPC] scale 1 or 2; CPC 1–2).

Results

The rates of patients receiving any BCPR and 1-month CPC 1–2 by year significantly increased from 46.2% and 9.4% in 2005 to 61.3% and 15.7% in 2017 (all P for trend &lt;0.0001), respectively. The rates of patients receiving C-BCPR in the pre-G2010 period significantly increased from 21.6% to 35.5% in the G2010 period, and to 40.4% in the G2015 period (P for trend &lt;0.0001); the overall proportion of cases with 1-month CPC 1–2 increased from 9.1% to 10.8% and 14.7%, respectively (P for trend &lt;0.0001). Particularly, in patients receiving C-BCPR, CPC 1–2 rate significantly increased from 9.5% in the pre-G2010 period to 19.0% in the G2015 period (P for trend &lt;0.0001). For all time periods, 1-month CPC 1–2 rate in the S-BCPR (17.2%) cohort was significantly higher than those in the C-BCPR (12.5%) and NO-BCPR (6.4%) cohorts (adjusted odds ratio [aOR] of S-BCPR compared with C-BCPR, 1.59; 95% confidence interval [CI], 1.25–2.01; P &lt; 0.0001; compared with NO-BCPR, aOR 2.31; 95% CI, 1.82–2.94; P &lt; 0.0001). No significant difference between S-BCPR and C-BCPR was found in 1-month CPC 1–2 rate for patients with non-traumatic origin (17.7% vs. 16.3%; aOR, 1.23, 95% CI, 0.95–1.59, all P &gt;0.05). However, in patients with traumatic origin, S-BCPR was superior to C-BCPR (15.1% vs. 3.4%; aOR, 4.53, 95% CI, 2.39–8.61, all P &lt;0.0001). During the 3 guidelines periods, the CPC 1–2 rate in patients with non-traumatic origin significantly increased from 11.8% to 19.7% (P for trend &lt; 0.0001), but not in patients with traumatic origin (from 4.9% to 4.1%, P for trend = 0.29).

Conclusions

During the 3 guidelines periods, the rate of C-BCPR and 1-month CPC 1–2 increased by approximately 2-fold each over time. C-BCPR was associated with increased odds of 1-month CPC 1–2 similar to S-BCPR for children with non-traumatic origin but not in those with traumatic origin.

P490Time boundaries of three-phase time-sensitive model for ventricular fibrillation cardiac arrest

Funding Acknowledgements

Japan Society for the Promotion of Science (KAKENHI Grant No. 18K09999)

Background

Recent clinical evidence has suggested that the pathophysiology of ventricular fibrillation (VF) cardiac arrest may consist of three time-sensitive phases, namely electrical, circulatory, and metabolic. According to this model of cardiopulmonary resuscitation (CPR), the optimal treatment of cardiac arrest is phase-specific. The potential survival benefit of bystander cardiopulmonary resuscitation (BCPR) depends in part on ischemic time (i.e., the collapse-to-shock interval), with the greatest benefit occurring during the circulatory (second) phase. However, the time boundaries between phases are not precisely defined in the current literature.

Purpose

The purpose of the present study was to determine the time boundaries of the three-phase time-sensitive model for VF cardiac arrest.

Methods

We reviewed 20,741 adult patients with initial VF after witnessed out-of-hospital cardiac arrest from a presumed cardiac origin who were included in the All-Japan Utstein-style registry from 2013 to 2017. We excluded patients who underwent bystander defibrillation prior to arrival of emergency medical services personnel. The study end point was 1-month neurologically intact survival (Cerebral Performance Category scale 1 or 2). Collapse-to-shock interval was defined as the time from collapse to first shock delivery by emergency medical services personnel. Patients were divided into two groups, BCPR (n = 11,606, 56.0%) and non-BCPR (n = 9135, 44.0%), according to whether they had received BCPR or not.

Results

The rate of 1-month neurologically intact survival in the BCPR group was significantly higher than that in the non-BCPR group (27.9% [3237/11,606] vs 17.9% [1632/9135], P &lt; 0.0001; adjusted odds ratio [OR], 1.90; 95% confidence interval [CI], 1.75–2.07; P &lt; 0.0001). Overall, increased collapse-to-shock interval was associated with significantly decreased adjusted odds of 1-month neurologically intact survival (adjusted OR for each 1-minute increase, 0.94; 95% CI, 0.93–0.95; P &lt; 0.0001). In the BCPR group, the ranges of collapse-to-shock interval that were associated with increased adjusted 1-month neurologically intact survival were from 7 minutes (adjusted OR, 1.95; 95% CI, 1.44–2.63; P &lt; 0.0001) to 17 minutes (adjusted OR, 2.82; 95% CI, 1.62–4.91; P = 0.0002) as compared with those in the non-BCPR group. However, the increase in neurologically intact survival of the BCPR group became statistically insignificant as compared with that of the non-BCPR group when the collapse-to-shock interval was outside these ranges.

Conclusions

The above-mentioned findings suggest that the time boundaries of the three-phase time-sensitive model for VF cardiac arrest may be as follows: electrical phase, from collapse to &lt;7 minutes; circulatory phase, from 7 to 17 minutes; and metabolic phase, &gt;17 minutes onward from collapse.

Design of a multiplex quantitative reverse transcription-PCR system to simultaneously detect 16 pathogens associated with bovine respiratory and enteric diseases

AIM

Bovine respiratory disease (BRD) and bovine enteric disease (BED) are two major diseases in cattle, resulting in severe economic losses in the dairy and beef industries. The two major diseases are associated with several factors such as viruses, bacteria, the health condition of the host and environmental factors. We aimed to design a new efficient diagnostic method, which rapidly detect causative pathogens, minimizing economic loss due to BRD and BED.

METHODS AND RESULTS

We designed a multiplex quantitative reverse transcription-PCR (qRT-PCR) system for the simultaneous diagnosis of 16 pathogens, including 12 viruses and 4 bacteria related to BRD and BED, based on single qRT-PCR assays in previous studies. The designed multiplex qRT-PCR was highly sensitive and has minimal detection levels which will be no different from those of single qRT-PCR. Moreover, the multiplex qRT-PCR could more efficiently detect the causative pathogens than conventional RT-PCR in test using a part of BRD and BED clinical samples. Furthermore, our data revealed that the multiplex qRT-PCR had high performance in its specificity and reproducibility tests.

CONCLUSIONS

Our system can effectively detect multiple BRD or BED related pathogens from each animal while testing several clinical samples via the multiplex qRT-PCR. It is more time-, cost- and labour-efficient than other diagnostic methods.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rapid detection of infected animals from the herd using our system will greatly contribute to infection control and prompt treatment in field.

Temperature dependent local atomic displacements in NaSn2As2 system

NaSn₂As₂ is mechanically exfoliable layered van der Waals (vdW) Zintl phase that is getting interesting due to its low thermal conductivity and recently observed superconductivity. Here, we have investigated the temperature dependent local structure of NaSn₂As₂ by a combined analysis of As K-edge and Sn K-edge extended x-ray absorption fine structure measurements. The system is intrinsically disordered with the interatomic distances largely consistent to those estimated by average structure measurements. The stretching force constants of different bond distances have been determined using temperature dependent mean square relative displacements. The Sn-As distance is the strongest bond in this system, having covalent nature, unlike the weaker interlayer distances which are characterized by vdW type bonding. Among them, As-Na distance is slightly weaker than Sn-Sn(i) below  ∼200 K and tends to get stronger above this temperature. The anomalous behavior of As-Na bond suggests that the mechanical exfoliation in this system is likely to be temperature dependent. The anomaly in the interlayer atomic correlations may be due to a charge density wave-like instability around this temperature, indicated by earlier experiments. The local structure and disorder are discussed in relation to the physical properties of NaSn₂As₂.

Three-dimensional mean CT attenuation value of pure and part-solid ground-glass lung nodules may predict invasiveness in early adenocarcinoma

AIM

This study evaluated the relationship between three-dimensional (3D) mean computed tomography (CT) attenuation values of ground-glass nodules (GGN) and pathological invasiveness in early lung adenocarcinoma. The diagnostic accuracy of 3D CT attenuation values was compared with that of two-dimensional (2D) CT attenuation values and standardised uptake value on positron-emission tomography (PET).

MATERIALS AND METHODS

Surgical and radiological data from 96 pure or part-solid GGNs of <20 mm were analysed retrospectively. Mean 2D and 3D CT attenuation values of the tumours were obtained with semi-automated volumetric software. Pathological invasiveness was diagnosed according to the International Association for the Study of Lung Cancer (IASLC))/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification. Pre-invasive lesions and minimally invasive adenocarcinomas were classified as non-invasive adenocarcinoma. Univariate and multivariate analyses determined relationships between pathological invasiveness and clinical/radiological findings. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cut-off value for detecting invasive adenocarcinoma.

RESULTS

A total of 66 non-invasive and 30 invasive adenocarcinoma cases between 2010 and 2016 were analysed. Univariate analysis revealed four tumour invasiveness-associated predictors: maximum diameter, SUVmax, mean 2D CT attenuation value, and mean 3D CT attenuation value (p<0.05). Multivariate analysis revealed that the maximum diameter, SUVmax, and mean 3D CT attenuation value were significant predictors of pathological invasiveness (p=0.023, 0.022, 0.004). The area under the ROC curve to predict invasive adenocarcinoma for mean 3D CT attenuation value was 0.838 and the cut-off value was -489 HU.

CONCLUSION

The mean 3D CT attenuation value could distinguish pre-invasive lesions and minimally invasive adenocarcinoma from invasive adenocarcinoma.