A cold-atom Ramsey clock with a low volume physics package

We demonstrate a Ramsey-type microwave clock interrogating the 6.835 GHz ground-state transition in cold [Formula: see text]Rb atoms loaded from a grating magneto-optical trap (GMOT) enclosed in an additively manufactured loop-gap resonator microwave cavity. A short-term stability of [Formula: see text] is demonstrated, in reasonable agreement with predictions from the signal-to-noise ratio of the measured Ramsey fringes. The cavity-grating package has a volume of [Formula: see text]67 cm[Formula: see text], ensuring an inherently compact system while the use of a GMOT drastically simplifies the optical requirements for laser cooled atoms. This work is another step towards the realisation of highly compact portable cold-atom frequency standards.

A goal-oriented hemodynamic approach to acute myocardial infarction complicated by cardiogenic shock-A single center experience

BACKGROUND

Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is the most common cause of mortality following AMI, and treatment algorithms vary widely. We report the results of an analysis using time-sensitive, hemodynamic goals in the treatment of AMI-CS in a single center study.

METHODS

Consecutive patients with AMI-CS from November 2016 through December 2021 were included in our retrospective analysis. Clinical characteristics and outcomes were analyzed using the electronic medical records. We identified 63 total patients who were admitted to our center with AMI-CS, and we excluded patients who did not have clear timing of AMI onset or CS onset. We evaluated the rate of survival to hospital discharge based on the quantity of certain time-sensitive hemodynamic goals were met.

RESULTS

We identified 63 patients who met criteria for AMI-CS, 39 (62%) of whom survived to hospital discharge. Odds of survival were closely related to the achievement of four time-dependent goals: cardiac power output (CPO) >0.6 Watts (W), pulmonary artery pulsatility index (PAPi) >1, lactate <4 mmol/L, and <2 vasopressors required. Of the 63 total patients, 36 (57%) received intra-aortic balloon pump (IABP) and 18 (29%) received an Impella CP (Abiomed) as an initial mechanical circulatory support strategy. Six patients were escalated from IABP to Impella CP for additional hemodynamic support. Nine patients were treated with vasopressors/inotropes alone. Regarding the 39 patients who survived to hospital discharge, 75% of patients met 3 or 4 goals at 24 h, whereas only 16% of deceased patients met 3 or 4 goals at 24 h. Of the 24 patients who did not survive to hospital discharge, 18 (75%) met either 0-1 goal at 24 h. There was no effect of the initial treatment strategy on achieving 3-4 goals at 24 h.

CONCLUSION

Our study evaluated the association of meeting 4 time-sensitive goals (CPO >0.6 W, PAPi >1, <2 vasopressors, and lactate <4 mmol/L) at 24 h after treatment for AMI-CS with in-hospital mortality. Our data show, in line with previous data, that the higher number of goals met at 24 h was associated with improved in-hospital mortality regardless of treatment strategy.

Differential Neutralization of Apixaban, Betrixaban, Edoxaban, and Rivaroxaban by Andexanet Alfa as Measured by Whole Blood Thromboelastographic Analysis

INTRODUCTION

The available oral anti-Xa agents are routinely used for the management of thrombotic disorders. A molecularly modified recombinant coagulation FXa, also known as Andexanet Alfa (AA), that has been developed as an antidote to neutralize the bleeding effects of oral FXa inhibitors, such as Apixaban and Rivaroxaban.

MATERIALS AND METHODS

This study utilized thromboelastography (TEG 5000 Hemostasis System), to investigate the neutralizing effects of AA at different concentrations of oral FXa inhibitors measuring such parameters as R-Time, K-Time, Angle, and Max Amplitude (MA). Apixaban, Betrixaban, Edoxaban, and Rivaroxaban were obtained commercially in powdered form. Each of these drugs was supplemented with freshly drawn whole citrated blood at a concentration of 1 μg/mL. And subsequently mixed with AA at 50 or 100 μg/mL.

RESULTS

At a concentration of 1 μg/mL, all FXa inhibitors produced variable anticoagulant effects in the order of Edoxaban > Betrixaban > Rivaroxaban > Apixaban. AA at 100 μg/mL produced a complete neutralization of these inhibitors whereas at 50 μg/mL relatively weaker neutralization as measured by various parameters.

CONCLUSION

These results suggest that regardless of the variable anticoagulant effects exhibited by the FXa Inhibitors, AA at FC = 100 μg/mL fully neutralized these agents as measured by the TEG parameters. AA was shown to be more effective in neutralizing Betrixaban and least effective in Apixaban. The neutralization of various FXa inhibitors was dose and donor-dependent warranting dosage adjustment for optimal outcomes.

External validation of a low fidelity dry-lab platform to enhance loupes surgical skills techniques for hypospadias repair

INTRODUCTION

Hypospadias repair is an index pediatric urology procedure that requires trainee familiarity with surgical loupes. A previous low-fidelity, 6-step curriculum was proposed that deconstructed the most important steps of loupe surgery. We expanded on this curriculum with an intermediate-fidelity silicone hypospadias model and designed an abbreviated version of the 6-step curriculum to precede the hypospadias repair simulation.

OBJECTIVE

To assess the validity of our prior, low-fidelity conceptual model using the metric of improved performance on the intermediate-fidelity silicone hypospadias model.

STUDY DESIGN

A silicone model was first prototyped with the design software Solidworks™, and then fabricated using a cast made of a mixture of silicone rubbers designed to function like skin and soft tissue (Mold Star 20T, Dragon skin FX-pro and Slacker). Casts were used to create the penile shaft model and the dorsal hooded foreskin model. The urethral plate was cast separately on a flat surface. The model was then assembled by hand. The model used for simulation included the penile shaft and urethral plate, while the dorsal-hooded foreskin was prepared to simulate the penile anatomy separately. Trainees were then divided into two groups. Group 1 practiced the low-fidelity curriculum (3 tasks) and then performed dissection of the urethral plate and suturing using the intermediate-fidelity hypospadias model. Group 2 practiced hypospadias repair prior to the low-fidelity curriculum. Both groups' models were scored by 3 blinded urologists. Trainees were then asked to complete a post simulation satisfaction survey. Data analysis was performed in IBM SPSS Statistics for Macintosh (Version 28.0 Armonk, NY: IBM Corp).

RESULTS

Twenty-two candidates across Wisconsin, USA, and Dublin, Ireland participated in the study. This included 7 s-year residents, 9 third-year residents, 2 fourth-year residents, and 3 fifth-year residents. Both Groups 1 and 2 had a similar distribution of trainees (p = 0.60). Group 1 outperformed group 2 in all tasks (p < 0.05, Table 1). Trainees reported that the platform was very useful (91%).

DISCUSSION

Our curriculum showed improvement in trainee ability and comfort to perform hypospadias repair. Advantages of such a simulated curriculum include improving current resident training in microsurgery, improving surgical ergonomics for trainees prior to real-time experience, and decreasing the learning curve for trainees pursuing pediatric urology.

CONCLUSION

An intermediate-fidelity hypospadias platform externally validates the conceptual model implemented in the low-fidelity loupes curriculum. This appears to lead to improvement in loupe surgical skills regardless of trainee level.

Tricuspid regurgitation worsening after transcatheter or surgical aortic valve replacement

Background

Tricuspid regurgitation (TR) often occurs concomitantly with severe aortic stenosis. Post-operative worsening of tricuspid regurgitation has been observed after surgical and transcatheter aortic valve replacement (SAVR, TAVR) [1,2].

Purpose

Pre-procedural severe tricuspid regurgitation has been shown to be a predictor of all-cause mortality in patients undergoing transcatheter aortic valve replacement (TAVR) [3,4]. However, little is known about the incidence of worsening tricuspid regurgitation after SAVR and TAVR and the impact on post-procedural outcomes. This study aims to evaluate, characterize and compare the incidence of worsening TR after TAVR and SAVR.

Methods

Retrospective single-center study of patients undergoing Transcatheter and Surgical Aortic Valve Replacement for severe aortic stenosis between 2014 and 2020. Incidence of tricuspid regurgitation was noted on echocardiogram at baseline and 1 year after TAVR or SAVR. This study enrolled 430 patients in the TAVR group and 237 patients in the SAVR group. The SAVR group only included patients who underwent isolated SAVR without any other valve intervention. Patients with severe TR at baseline were excluded from the study. Progression of TR severity was defined as deterioration by at least 1 grade of severity compared to baseline on echocardiography. Multivariable logistic regression analysis was performed to identify associations with worsening TR.

Results

Mean age of TAVR patients was higher than the SAVR patients (79±9 vs 68±12 years, p&lt;0.0001). TAVR patients also had a significantly higher EuroSCORE than the SAVR patients (8.0±7 vs 3.5±4, p&lt;0.0001). TAVR group was more likely to have atrial fibrillation than the SAVR group (34% vs 24%, p=0.006). Baseline right ventricular dysfunction and right ventricular enlargement were significantly higher in the TAVR group compared to the SAVR group [9% vs 4%, (p=0.009) and 10% vs 6%, (p=0.04), respectively]. Progression of TR severity occurred in 21.8% (94/430) of TAVR patients and 31.2% (74/237) of SAVR patients. Majority of these patients progressed from absent TR to mild TR [13.2% (57) in TAVR group vs 19.8% (47) in SAVR group (p=0.02)]. 6.3% (27) of patients in the TAVR group and 8.8% (21) of patients in the SAVR group had mild to moderate worsening of TR (p=0.22). 1.63% (7) in the TAVR group and 2.1% (5) in the SAVR group had progression from moderate to severe TR (p=0.65). On multivariable analysis, SAVR (Odds ratio, 2.46 [CI, 1.6–3.7]) and age (Odds ratio, 1.03 [CI, 1.03–1.05]) were associated with worsening TR severity.

Conclusions

In this retrospective observational study, SAVR and age were found to be associated with worsening tricuspid regurgitation. Majority of these patients progressed from absent TR to mild TR after SAVR. Further studies are necessary to determine long term outcomes of worsening tricuspid regurgitation after TAVR and SAVR.

Funding Acknowledgement

Type of funding sources: None.

4 year outcomes in a prospective evaluation of transcatheter mitral valve-in-valve, valve-in-ring and valve-in-mitral annular calcification: results from the MITRAL trial

Background

The MITRAL Trial (Mitral Implantation of TRAnscatheter vaLves) evaluates the safety and feasibility of balloon-expandable aortic transcatheter heart valves in patients with severe mitral valve disease with mitral annular calcification (MAC), failed surgical rings or failed bioprostheses.

Purpose

We sought to evaluate 4-year outcomes of patients enrolled in the MITRAL trial.

Methods

This is a prospective study that enrolled 91 high surgical risk patients at 13 sites in the U.S. 30 patients underwent Mitral Valve-in-Valve (MViV), 30 Valve-in-Ring (MViR) and 31 Valve-in-MAC (ViMAC). 4-year outcomes of these patients were evaluated in this analysis. Primary endpoints and key serious adverse events including deaths were adjudicated by an independent Clinical Events Committee. Cardiac computed tomography (CT) and echocardiographic images were evaluated by independent CT and Echocardiographic Core Laboratories.

Results

Mean age was 74.3±8.9 years. Most patients undergoing MViV and ViMAC were female (MVIV=63.3%, MViR=36.7% and ViMAC=71%). Mean STS score was 9.2±6.6% (MViV 10.2±6.5%, MViR 8.7±4.7%, ViMAC=8.6±8.2%). All-cause mortality at 4 years was higher for ViMAC and MViR: MViV=6.9% (cardiovascular 3.4%), MViR=48.1% (cardiovascular 18.5%), ViMAC=51.9% (cardiovascular 29.6%), p=0.002 (Figure 1). At 4 years, all survivors had ≤1+ mitral regurgitation and most had none or trace mitral regurgitation (MViV=87.5, MViR=33.3% and ViMAC=100%). Mean mitral valve gradients remained stable (MViV=5.9±2.2 mmHg, MViR= 6.6±5.1 mmHg, ViMAC=5.1±1.0 mmHg), Figure 2. Most survivors experienced significant improvement of symptoms and were in NYHA class I-II at 4-year follow-up (MViV=78.9%, MViR=66.7% and ViMAC=66.7%).

Conclusions

MViV is associated with excellent outcomes at 4 years. MViR and ViMAC were associated with higher mortality at 4 years. However, most survivors in all groups experienced sustained improvement of symptoms and stable THV performance at 4 years. Whether survival bias had an impact on THV performance and improved symptoms at follow-up is not known and deserves further evaluation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Unrestricted Research Grant from Edwards Lifesciences.

Outcomes of ST-Elevation Myocardial Infarction due to spontaneous coronary artery dissection: a nationwide cohort sample

Background

Spontaneous coronary artery dissection (SCAD) is a common, non-atherosclerotic cause of myocardial infarction (MI). While conservative therapy is preferred in most cases, its role among those presenting as ST-elevation myocardial infarction (STEMI) remains undefined.

Purpose

We aimed to explore outcomes of SCAD causing STEMI, stratifying cases by involved coronary artery and revascularization status.

Methods

We used the Nationwide Readmission Database (2015–2018) to identify patients hospitalized with STEMI by using ICD-10-Clinical modification codes, and then stratified them into SCAD or no-SCAD groups. Each group was further subdivided by involved coronary artery (i.e., left main, left anterior descending, left circumflex, or right coronary artery), and if revascularization (i.e., percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)) was performed. We excluded patients &gt;55 years old or with iatrogenic dissection. The age restriction allows us to compare a similarly aged group of patients. The primary outcome was in-hospital mortality. Cardiogenic shock, acute kidney injury, mechanical complications, length of stay, and 30-day readmission for all-cause, heart failure or MI were secondary outcomes.

Results

Of the 17,556 patients with STEMI identified, 338 (1.9%) had SCAD. Patients with SCAD were younger (median age (IQR) 46.0 (33–90) vs 49.0 (41–57); p&lt;0.001) and more likely to be female (67% vs 21.6%, p&lt;0.001). They were less likely to have PCI (55.3% vs. 80.7%; p&lt;0.001), more likely to undergo CABG (4.7% vs 1.3%; p&lt;0.001), with left main and left anterior descending coronary arteries more often affected (2.4% vs 1.1%, and 53.3% vs 48.6%; p for both =0.05, respectively). In-hospital mortality did not differ between groups (3.6% vs 3.3, p=0.81). Revascularization was associated with lower in-hospital mortality among no-SCAD patients (2.6% vs 7.0%, p&lt;0.001), but not among SCAD patients (4.0% vs 3.1%, p=0.76) even when stratified by involved coronary artery. Revascularization among SCAD patients was associated with lower 30-day readmission rates for MI (0.0% vs 2.8%, p=0.05). SCAD patients were less likely to have acute kidney injury (6.5% vs 11.2%, p=0.01), but had a longer length of stay (median (IQR) 3.0 (1.0–6.0) vs 2.0 (1.0–4.0), p&lt;0.001). Both groups had similar rates of cardiogenic shock (11.8% vs 10.6%, p=0.56), mechanical complications (0.6% vs 0.3%, p=0.22), and 30-day readmission rates for all-cause, and heart failure.

Conclusion

In-hospital mortality did not differ between patients with STEMI due to SCAD or no-SCAD. Although revascularization was not associated with lower in-hospital mortality among SCAD patients (regardless of involved coronary artery), their 30-day readmission rate for MI was lower suggesting further studies are warranted to explore patient subsets of SCAD that may benefit from revascularization.

Funding Acknowledgement

Type of funding sources: None.

An Update on the Pathogenesis of COVID-19 and the Reportedly Rare Thrombotic Events Following Vaccination

Today the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become a global health problem. After more than a year with the pandemic, although our knowledge has progressed on COVID-19, there are still many unknowns in virological, pathophysiological and immunological aspects. It is obvious that the most efficient solution to end this pandemic are safe and efficient vaccines. This manuscript summarizes the pathophysiological and thrombotic features of COVID-19 and the safety and efficacy of currently approved COVID-19 vaccines with an aim to clarify the recent concerns of thromboembolic events after COVID-19 vaccination. The influx of newer information is rapid, requiring periodic updates and objective assessment of the data on the pathogenesis of COVID-19 variants and the safety and efficacy of currently available vaccines.

Recent declines in salmon body size impact ecosystems and fisheries

Declines in animal body sizes are widely reported and likely impact ecological interactions and ecosystem services. For harvested species subject to multiple stressors, limited understanding of the causes and consequences of size declines impedes prediction, prevention, and mitigation. We highlight widespread declines in Pacific salmon size based on 60 years of measurements from 12.5 million fish across Alaska, the last largely pristine North American salmon-producing region. Declines in salmon size, primarily resulting from shifting age structure, are associated with climate and competition at sea. Compared to salmon maturing before 1990, the reduced size of adult salmon after 2010 has potentially resulted in substantial losses to ecosystems and people; for Chinook salmon we estimated average per-fish reductions in egg production (-16%), nutrient transport (-28%), fisheries value (-21%), and meals for rural people (-26%). Downsizing of organisms is a global concern, and current trends may pose substantial risks for nature and people.

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.

Commentary on Ferguson, et al., "Impact of Non-pharmaceutical Interventions (NPIs) to Reduce COVID-19 Mortality and Healthcare Demand"

A recent manuscript (Ferguson et al. in Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand, Imperial College COVID-19 Response Team, London, 2020. https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf) from Imperial College modelers examining ways to mitigate and control the spread of COVID-19 has attracted much attention. In this paper, we will discuss a coarse taxonomy of models and explore the context and significance of the Imperial College and other models in contributing to the analysis of COVID-19.

Cold-atom clock based on a diffractive optic

Clocks based on cold atoms offer unbeatable accuracy and long-term stability, but their use in portable quantum technologies is hampered by a large physical footprint. Here, we use the compact optical layout of a grating magneto-optical trap (gMOT) for a precise frequency reference. The gMOT collects 10^{7 87}Rb atoms, which are subsequently cooled to 20 µK in optical molasses. We optically probe the microwave atomic ground-state splitting using lin⊥lin polarised coherent population trapping and a Raman-Ramsey sequence. With ballistic drop distances of only 0.5 mm, the measured short-term fractional frequency stability is 2×10^-11/τ.

6098The role of diastolic function in risk stratification of patients with moderate aortic stenosis

Background

Currently data on the risk stratification of patients with moderate aortic stenosis (AS) are very limited.

Method

Patients diagnosed with moderate AS in 2012 (aortic valve area [AVA]: >1 and ≤1.5cm2) were identified. Patients were stratifying by LV diastolic function (normal vs high filling pressure), left ventricular ejection fraction (LVEF ≥50 vs <50%) and stroke volume index (SVI ≥35 vs <35 ml/m2). High filling pressure was defined as average E/e' ≥14 or septal E/e' ≥11 when atrial fibrillation was present. The prognosis was compared to age- and sex-matched general population.

Results

898 patients were included (age 74 years, 58% male, AVA 1.25 cm2). During a median follow-up of 2.9 years, there were 346 deaths. In patients with moderate AS, mortality was higher than expected (P<0.001, Fig 1A). LV high filling pressure, LVEF<50% and SVI<35ml/m2 were present in 416 (55%), 140 (17%) and 81 (9%) patients, respectively. Those with normal filling pressure had similar prognosis when compared to controls (Fig 1C, P=0.35); whereas mortality rates remained higher than reference even when LVEF≥50% or SVI≥35ml/m2 (Fig 1E, 1G, P<0.001). Amongst all groups, mortality rates were the highest in patients with LVEF <50% or SVI <35 ml/m2 (Fig 1D, 1F, P<0.001); mortality ratios were 3.78 (95% CI 3.01–4.67) and 6.91 (95% CI 5.13–9.11), respectively. Noteworthy, high filling pressure allowed further risk stratification when LVEF or SVI was preserved (Fig 2, P<0.001).

Figures 1 & 2

Conclusions

Patients with moderate AS showed poor survival. A clinical trial examining role of aortic valve replacement would be beneficial not only in patients with reduced LVEF or SVI but also in those with high LV filling pressures.

P3634Cancer patients have a higher long-term risk of death and myocardial infarction after percutaneous coronary intervention - A matched cohort analysis of 3,560 patients

Background

Cancer patients have a higher risk of thromboembolic events but it is not well known if these patients also have a higher risk of death, myocardial infarction (MI) or repeat revascularization after percutaneous coronary intervention (PCI) is unknown.

Methods

Cancer patients who underwent first-time single vessel PCI from January 1, 2003, through December 31, 2013 were identified by cross-matching of institutional cancer and PCI registries. These cancer patients were matched 4:1 to non-cancer patients, likewise undergoing first-time single vessel PCI in the time period. The combined primary endpoint was death, MI and revascularization at 5 year follow-up. Secondary endpoints were death and MI combined and the individual components of the primary endpoint. Both time dependent and non-time-dependent analyses were conducted.

Results

A total of 712 cancer patients were identified and matched to 2,848 non-cancer patients (one third women in either group). Bare-metal stents were used in one third of patients in both groups. The combined primary study endpoint was significantly more frequently encountered in the cancer than in the non-cancer group in both time-dependent (Figure 1) and non-time dependent analyses (5-year event rate 48.6% vs. 31.2%, p<0.001). This was driven by a higher 5-year event rate of death (39.0% vs. 20.1%) and MI (14.8% vs 4.86%) in the cancer group. The 5-year rate of revascularization did not differ significantly between the two groups (10.5% vs 10.3%).

Figure 1. MI + revascularization-survival

Conclusion

Cancer patients have a two times higher rate of death and a three times higher rate of MI over the first 5 years after PCI. Future studies will need to define the etiology and factors accounting for this higher event rate in cancer patients, especially of these patients are predisposed to stent thrombosis and need longer term dual antiplatelet therapy.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Impact of Emergency Medical Services Activation of the Cardiac Catheterization Laboratory and a 24-Hour/Day In-Hospital Interventional Cardiology Team on Treatment Times (Door to Balloon and Medical Contact to Balloon) for ST-Elevation Myocardial Infarction

The incremental benefit of emergency medical services (EMS) activation of the cardiac catheterization laboratory (CCL) for ST-elevation myocardial infarction (STEMI) in the setting of an established in-house interventional team (IHIT) is uncertain. We evaluated the impact of EMS activation on door-to-balloon (D2B) time and first medical contact-to-balloon (FMC2B) time for STEMI when coupled with a 24-hour/day IHIT. All patients presenting with STEMI to Loyola University Medical Center had demographic, procedural, and outcome data consecutively entered in a STEMI Data Registry. From 223 consecutive patients presenting between April 2009 and December 2015, a retrospective analysis was performed on 190 patients. Patients were divided into 2 groups depending on CCL activation mode (EMS activation or emergency department activation) and STEMI treatment process times were compared. The primary end point was D2B process times. The secondary end point was FMC2B process times in a subgroup analysis of EMS-transported patients. D2B times were shorter (37 ± 14 minutes vs 57 ± 27 minutes, p < 0.001) with EMS activation. Subgroup analysis of EMS-transported patients demonstrated shorter FMC2B times with EMS activation (52 ± 17 minutes vs 67 ± 32 minutes, p = 0.002). EMS activation was the only predictor of D2B ≤60 minutes in multivariable analysis of EMS-transported patients (odds ratio 9.4; 95% confidence interval 2.1 to 43.0; p = 0.04). In conclusion, EMS activation of the CCL in STEMI was associated with significant improvements in already excellent D2B and FMC2B times even in the setting of a 24-hour/day IHIT.

Meta-Analysis of Studies Comparing Dual- Versus Mono-Antiplatelet Therapy Following Transcatheter Aortic Valve Implantation

Current guidelines recommend dual-antiplatelet therapy (DAPT) after transcatheter aortic valve implantation (TAVI), although some studies suggest mono-antiplatelet therapy is equally efficacious with an improved safety profile. We performed a meta-analysis of studies comparing DAPT with mono-antiplatelet therapy after TAVI. Study quality and heterogeneity were assessed using Jadad score, Newcastle-Ottawa Scale, and Cochran's Q statistics. Mantel-Haenszel odds ratios (ORs) were calculated using fixed effect models as the primary analysis. Eight studies including 2,439 patients met the inclusion criteria. At 30 days, DAPT was associated with an increased risk of all-cause mortality (OR 2.06, 95% confidence interval [CI] 1.34 to 3.18, p = 0.001), major or life-threatening bleeding (OR 2.04, 95% CI 1.60 to 2.59, p <0.001), and major vascular complications (OR 2.15, 95% CI 1.51 to 3.06, p <0.001). There was no difference in the rate of the combined end point of stroke or transient ischemic attack, or myocardial infarction. Outcome data up to 6 months were available in 5 studies; all-cause mortality and stroke were similar between groups, although major or life-threatening bleeding was more frequent with DAPT. In conclusion, in patients undergoing TAVI, DAPT is associated with increased risk at 30 days of all-cause mortality, major or life-threatening bleeding, and major vascular complications without a decrease in ischemic complications; at 6 months, the excess bleeding risk persisted. These data suggest a safety concern with DAPT and justify further investigation of the optimal antiplatelet therapy regimen after TAVI.

Circulation of cosmogenic 22Na using the global monitoring network of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO)

Using a recently published global data set of ²²Na and ⁷Be from the global monitoring network of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), atmospheric circulation and stratosphere-troposphere interactions are examined. Cosmogenic ²²Na has a half-life well-suited to environmental processes with durations from several months to a decade. Combined with corresponding ⁷Be observations, these two cosmogenic isotopes form a useful environmental tracer and new radiochronometer to study physical interactions of air masses in the stratosphere and troposphere.

A pilot study of recombinant insulin-like growth factor-I in seven multiple sclerosis patients

The purpose of this open-label, crossover study was to determine the safety and efficacy of recombinant insulin-like growth factor-I (rhIGF-I) using magnetic resonance imaging (MRI) and clinical measures of disease activity in seven multiple sclerosis (MS) patients. Monthly clinical and MRI examinations were performed during a 24-week baseline and a 24-week treatment period with rhIGF-I. The primary outcome measure was contrast enhancing lesion (CEL) frequency on treatment compared to baseline. Secondary outcome measures included clinical and MRI measures of disease activity including. white matter lesion load (WMLL), magnetization transfer ratio (MTR), TI-Hypointensity volume, cervical spine cross-sectional area and proton magnetic resonance spectroscopic (MRS) imaging for determining regional metabolite ratios. rhIGF-I (Cephalon) was administered at a dose of 50 mg subcutaneously twice a day for 6 months. rhIGF-I was safe and well tolerated with no severe adverse reactions. There was no significant difference between baseline and treatment periods for any MRI or clinical measures of disease activity. Although rhIGF-I did not alter the course of disease in this small cohort of MS patients, the drug was well tolerated. Further studies using rhIGF-I alone or in combination with other therapies may be of value because of the proposed mechanism of action of this growth factor on the oligodendrocyte and remyelination. Multiple Sclerosis (2002)8,24-29

Analysis of 22Na using a spectral summation technique on high-volume aerosol samples

Measurement of cosmogenic ²²Na in daily aerosol samples is often difficult due to low atmospheric production rates. A new technique based upon spectral summation of sequential high-volume aerosol samples to measure ²²Na is described and validated. This summation technique has broad applications to any detection system that produces sequential representative sample measurements in which radioisotopes are just below the detection limit, provided the energy calibration is stable. It is anticipated that a global dataset of this radionuclide will have many important environmental science applications.

A NEW SEMI-EMPIRICAL AMBIENT TO EFFECTIVE DOSE CONVERSION MODEL FOR THE PREDICTIVE CODE FOR AIRCREW RADIATION EXPOSURE (PCAIRE)

The Predictive Code for Aircrew Radiation Exposure (PCAIRE) is a semi-empirical code that estimates both ambient dose equivalent, based on years of on-board measurements, and effective dose to aircrew. Currently, PCAIRE estimates effective dose by converting the ambient dose equivalent to effective dose (E/H) using a model that is based on radiation transport calculations and on the radiation weighting factors recommended in International Commission on Radiological Protection (ICRP) 60. In this study, a new semi-empirical E/H model is proposed to replace the existing transport calculation models. The new model is based on flight data measured using a tissue-equivalent proportional counter (TEPC). The measured flight TEPC data are separated into a low- and a high-lineal-energy spectrum using an amplitude-weighted ¹³⁷Cs TEPC spectrum. The high-lineal-energy spectrum is determined by subtracting the low-lineal-energy spectrum from the measured flight TEPC spectrum. With knowledge of E/H for the low- and high-lineal-energy spectra, the total E/H is estimated for a given flight altitude and geographic location. The semi-empirical E/H model also uses new radiation weighting factors to align the model with the most recent ICRP 103 recommendations. The ICRP 103-based semi-empirical effective dose model predicts that there is a ∼30 % reduction in dose in comparison with the ICRP 60-based model. Furthermore, the ambient dose equivalent is now a more conservative dose estimate for jet aircraft altitudes in the range of 7-13 km (FL230-430). This new semi-empirical E/H model is validated against E/H predicted from a Monte Carlo N-Particle transport code simulation of cosmic ray propagation through the Earth's atmosphere. Its implementation allows PCAIRE to provide an accurate semi-empirical estimate of the effective dose.

Leigh-Like Syndrome Due to Homoplasmic m.8993T>G Variant with Hypocitrullinemia and Unusual Biochemical Features Suggestive of Multiple Carboxylase Deficiency (MCD)

Leigh syndrome (LS), or subacute necrotizing encephalomyelopathy, is a genetically heterogeneous, relentlessly progressive, devastating neurodegenerative disorder that usually presents in infancy or early childhood. A diagnosis of Leigh-like syndrome may be considered in individuals who do not fulfil the stringent diagnostic criteria but have features resembling Leigh syndrome.We describe a unique presentation of Leigh-like syndrome in a 3-year-old boy with elevated 3-hydroxyisovalerylcarnitine (C5-OH) on newborn screening (NBS). Subsequent persistent plasma elevations of C5-OH and propionylcarnitine (C3) as well as fluctuating urinary markers were suggestive of multiple carboxylase deficiency (MCD). Normal enzymology and mutational analysis of genes encoding holocarboxylase synthetase (HLCS) and biotinidase (BTD) excluded MCD. Biotin uptake studies were normal excluding biotin transporter deficiency. His clinical features at 13 months of age comprised psychomotor delay, central hypotonia, myopathy, failure to thrive, hypocitrullinemia, recurrent episodes of decompensation with metabolic keto-lactic acidosis and an episode of hyperammonemia. Biotin treatment from 13 months of age was associated with increased patient activity, alertness, and attainment of new developmental milestones, despite lack of biochemical improvements. Whole exome sequencing (WES) analysis failed to identify any other variants which could likely contribute to the observed phenotype, apart from the homoplasmic (100%) m.8993T>G variant initially detected by mitochondrial DNA (mtDNA) sequencing.Hypocitrullinemia has been reported in patients with the m.8993T>G variant and other mitochondrial disorders. However, persistent plasma elevations of C3 and C5-OH have previously only been reported in one other patient with this homoplasmic mutation. We suggest considering the m.8993T>G variant early in the diagnostic evaluation of MCD-like biochemical disturbances, particularly when associated with hypocitrullinemia on NBS and subsequent confirmatory tests. An oral biotin trial is also warranted.