Improved Tensor Current Limit from ^{8}B β Decay Including New Recoil-Order Calculations

A precision measurement of the β^{+} decay of ^{8}B was performed using the Beta-decay Paul Trap to determine the β-ν angular correlation coefficient a_{βν}. The experimental results were combined with new ab initio symmetry-adapted no-core shell-model calculations to yield the second-most precise measurement from Gamow-Teller decays, a_{βν}=-0.3345±0.0019_{stat}±0.0021_{syst}. This value agrees with the standard model value of -1/3 and improves uncertainties in ^{8}B by nearly a factor of 2. By combining results from ^{8}B and ^{8}Li, a tight limit on tensor current coupling to right-handed neutrinos was obtained. A recent global evaluation of all other precision β decay studies suggested a nonzero value for right-handed neutrino coupling in contradiction with the standard model at just above 3σ. The present results are of comparable sensitivity and do not support this finding.

Angular Correlations in the β Decay of ^{8}B: First Tensor-Current Limits from a Mirror-Nucleus Pair

We present the first measurement of the α-β-ν angular correlation in the Gamow-Teller β^{+} decay of ^{8}B. This was accomplished using the Beta-decay Paul Trap, expanding on our previous work on the β^{-} decay of ^{8}Li. The ^{8}B result is consistent with the V-A electroweak interaction of the standard model and, on its own, provides a limit on the exotic right-handed tensor current relative to the axial-vector current of |C_{T}/C_{A}|^{2}<0.013 at the 95.5% confidence level. This represents the first high-precision angular correlation measurements in mirror decays and was made possible through the use of an ion trap. By combining this ^{8}B result with our previous ^{8}Li results, we demonstrate a new pathway for increased precision in searches for exotic currents.

Female patients with coronary artery disease and aortic stenosis undergoing a surgical or interventional treatment in terms of revascularization and valve replacement

Background

Coronary artery disease (CAD) in female patients undergoing a Transcatheter Aortic Valve Implantation (TAVI) is accompanied with a worse outcome compared to those without CAD. Nevertheless, it is still unclear whether a complete revascularization and outcome are achieved similarly in women treated with an interventional (PCI plus TAVI) or surgical (CABG plus SAVR) treatment strategy.

Purpose

This study aims to compare the completeness of revascularization in terms of residual SyntaxScore and to evaluate the differences in 30-days (short-term), one-year and three-years (intermediate term) mortality in women with CAD and AS undergoing a surgical or catheter-based treatment.

Methods

Patients were recruited at one tertiary center in Germany between 2016 and 2019. Initially the surgical group contained 932 patients and the interventional cohort 360 patients as a result of setting a maximum time interval of 3 months between PCI and TAVI.

The surgical group (CABG+SAVR) and the interventional group (PCI+TAVI) were compared by using a propensity score analysis. Age, left ventricular function, EuroSCORE II and degree of CAD served as matching parameters so that the matched female cohort finally consisted of 114 patients (57 patients treated interventionally, 57 treated surgically). Syntax Score was measured before and after revascularization. As a primary endpoint all-cause mortality was analyzed at 30 days, one and three years after the procedure.

Results

Median age was 80 years both in the interventional and surgical cohort (p=0.298). Both groups represented a moderate to high-risk population (EuroScore II in PCI+TAVI: 4.39 [2.83–8.82] vs 6.18 [3.43–8.6] in CABG+SAVR (p=0.279) and showed no significant difference in median pre-interventional/preoperative SyntaxScore I (PCI+TAVI: 16.00 [9–26.5] vs CABG+SAVR: 18 [9.5–25.5]; p=0.719). In the interventional group coronary physiology was measured more frequently (6.8% vs 1.8%, p=0.024). There was no significant difference in the presence of an aortoostial lesion, heavy calcification and a length of the lesion &gt;20mm between PCI+TAVI and CABG+SAVR before therapy (PCI+TAVI vs CABG+SAVR: 11.1% vs 13.0%, p=0.581; 60.5% vs 55.1%, p=0.289; 20.4% vs 25.1%, p=0.316). The main stem as target lesion was present in both groups with no significant difference (PCI+TAVI vs CABG+SAVR: 8.8% vs 19.3%, p=0.106).

Median residual SyntaxScore I was significantly higher in PCI+TAVI than in CABG+SAVR (5.0 [0.0–13.0] vs 0.0 [0.0–8.5], p=0.03).

No significant difference in 30-days, 1-year and 3-years mortality was observed between the interventional and surgical group (PCI+TAVI vs CABG+SAVR: 3.5% vs 8.8%, p=0.242; 10.5% vs 14%, p=0.568; 22.8% vs 15.8%, p=0.342).

Conclusion

Female patients with AS and CAD with low SyntaxScore undergoing CABG+SAVR reach a more complete revascularization than those treated interventionally. Nevertheless, this fact seems to have no influence on short and intermediate term mortality.

Funding Acknowledgement

Type of funding sources: None.

Improved Limit on Tensor Currents in the Weak Interaction from ^{8}Li β Decay

The electroweak interaction in the standard model is described by a pure vector-axial-vector structure, though any Lorentz-invariant component could contribute. In this Letter, we present the most precise measurement of tensor currents in the low-energy regime by examining the β-ν[over ¯] correlation of trapped ^{8}Li ions with the Beta-decay Paul Trap. We find a_{βν}=-0.3325±0.0013_{stat}±0.0019_{syst} at 1σ for the case of coupling to right-handed neutrinos (C_{T}=-C_{T}^{'}), which is consistent with the standard model prediction.

Short- and intermediate-term mortality in women and men after surgical versus interventional revascularization and aortic valve replacement

Background

Patients with isolated aortic valve stenosis (AS) at intermediate and even low-risk benefit from an interventional treatment with TAVI as compared to surgical aortic valve replacement. Whether patients with concomitant coronary artery disease have a better outcome with an interventional (PCI plus TAVI) or surgical (CABG plus SAVR) treatment strategy is still unclear.

Purpose

To evaluate the differences in 30-days (short-term) and one-year (intermediate term) mortality in women and men with CAD and AS undergoing a surgical or catheter-based treatment.

Methods

All patients were treated in Heart and Diabetes Center Bad Oeynhausen during 2016–2019. The surgical group contained 932 patients, the interventional cohort 360 patients as a result of setting a maximum time interval of 3 months between PCI and TAVR.

CABG+SAVR and PCI+TAVR cohorts were compared by using a propensity score analysis including age, left ventricular function, EuroSCORE II and degree of CAD as matching parameters. After matching the total cohort, 406 patients could be obtained. The matched female cohort consisted of 114 patients, the matched male cohort of 284 patients. As a primary endpoint all-cause mortality was analyzed at 30 days and one year after the procedure. Furthermore, procedural and post-procedural outcome were analyzed.

Results

The studied TAVI cohort was a low to intermediate risk population (EuroScore II of the total cohort: 3.82 [2.49–6.64] in CABG+SAVR vs 4.36 [2.59–7.12] in PCI+TAVR, p=0.38; women: 6.18 [3.43–8.6], p=0.279; men: 4.39 [2.83–8.82], p=0.279). There was no significant difference in 30-days mortality between the surgical and interventional group, regarding the total cohort (3.9% vs 2.5%; p=0.398). Whereas in the male cohort 30-days mortality was comparable between interventional and surgical treatment (2.1% vs 2.1%; p=1), in the female group the surgical treatment showed a trend towards higher mortality without reaching statistical significance (8.8% vs 3.5%; p=0.242). Additionally, one-year mortality did not differ in the three cohorts between CABG+SAVR and PCI+TAVR (total cohort: 11.3% vs 12.8%; p=0.648 women: 14% vs 10.5%; p=0.568; men: 11.3% vs 14.8%; p=0.378). The number of postprocedural permanent pacemaker implantations was statistically higher after TAVR plus PCI (total cohort: 7.4% vs 15.3%; p=0.012; women: 7% vs 19.3%; p=0.052; men: 8.5% vs 19%; p=0.01). Furthermore, a significantly longer length of hospital stay was reported for the surgical cohort (total cohort: 13 [11–17] vs 11 [9–15]; p=0; women: 14 [12–18] vs 12 [10.5–15.5]; p=0.019; men: 13 [11–15] vs 11 [9–15]; p=0).

Conclusion

In patients with AS and CAD there is no significant difference in short and intermediate term mortality when comparing surgical or interventional treatment.

Subsequently, an interventional approach might be a legitimate alternative to CABG+SAVR in these patients.

Funding Acknowledgement

Type of funding sources: None.

Tuberculosis and COVID-19 interaction: A review of biological, clinical and public health effects

Evidence is accumulating on the interaction between tuberculosis (TB) and COVID-19.

The aim of the present review is to report the available evidence on the interaction between these two infections. Differences and similarities of TB and COVID-19, their immunological features, diagnostics, epidemiological and clinical characteristics and public health implications are discussed. The key published documents and guidelines on the topic have been reviewed.

Based on the immunological mechanism involved, a shared dysregulation of immune responses in COVID-19 and TB has been found, suggesting a dual risk posed by co-infection worsening COVID-19 severity and favouring TB disease progression.

The available evidence on clinical aspects suggests that COVID-19 happens regardless of TB occurrence either before, during or after an active TB diagnosis. More evidence is required to determine if COVID-19 may reactivate or worsen active TB disease. The role of sequeale and the need for further rehabilitation must be further studied

Similarly, the potential role of drugs prescribed during the initial phase to treat COVID-19 and their interaction with anti-TB drugs require caution. Regarding risk of morbidity and mortality, several risk scores for COVID-19 and independent risk factors for TB have been identified: including, among others, age, poverty, malnutrition and co-morbidities (HIV co-infection, diabetes, etc.). Additional evidence is expected to be provided by the ongoing global TB/COVID-19 study.

Uninterrupted direct oral anticoagulants and vitamin K antagonists during ablation for atrial fibrillation: an updated meta-analysis

Background

Uninterrupted anticoagulation during catheter ablation of atrial fibrillation (CAAF) became standard of care after positive results of trials investigating vitamin K antagonists (VKA). Previous studies and meta-analyses of uninterrupted direct oral anticoagulants (DOAC) vs. VKA have given controversial results. We thus aimed to elucidate the risks and benefits of uninterrupted DOAC vs. VKA during CAAF in an updated meta-analysis of randomized controlled trials (RCTs).

Methods

Online databases were searched for RCTs comparing uninterrupted DOAC to VKA in patients undergoing CAAF until September 2019. Data from retrieved studies were analysed in a comprehensive meta-analysis. Primary safety outcome was major bleeding; primary efficacy outcome was stroke or transient ischemic attack (TIA). Secondary outcomes included a composite of major bleeding and stroke or TIA, minor bleeding, acute cerebral lesions on magnetic resonance imaging (ACL) and mortality.

Results

Six eligible RCTs comprising 2,369 patients were included. Pooled meta-analysis showed no significant differences in DOAC vs. VKA concerning the rates of major bleeding (2.2% vs. 3.8%; odds ratio (OR) 0.69, 95% confidence interval (CI) 0.30–1.56; p=0.37) and stroke or TIA (0.2% vs. 0.2%; OR 0.97, CI 0.20–4.72; p=0.97). There were no significant differences found in secondary outcomes (OR 0.73, p=0.49 for composite of major bleeding and stroke or TIA; OR 1.08, p=0.52 for minor bleeding; OR 1.12, p=0.59 for ACL; and OR=0.60, p=0.64 for all-cause mortality).

Conclusion

Our meta-analysis suggests that uninterrupted periprocedural anticoagulation with DOAC or VKA is characterized by a similar risk/benefit ratio in patients undergoing CAAF with comparable rates of major bleeding and stroke.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Medical faculty of the Heinrich-Heine-University Düsseldorf, Germany

Grazing mediates soil microbial activity and litter decomposition in salt marshes

Salt marshes contribute to climate change mitigation because of their great capacity to store organic matter (OM) in soils. Most of the research regarding OM turnover in salt marshes in times of global change focuses on effects of rising temperature and accelerated sea-level rise, while effects of land-use change have gained little attention. The present work investigates the mechanisms by which livestock grazing can affect OM decomposition in salt marsh soils. In a grazing exclusion experiment at the mouth of the Yangtze estuary, China, we assessed soil microbial exo-enzyme activity (EEA) to gain insight into the microbial carbon (C) and nitrogen (N) demand. Additionally, we studied the decomposition of plant litter in soil using the Tea Bag Index (TBI), a widely used standardized litter bag assay to fingerprint soil decomposition dynamics. Based on EEAs, grazing markedly reduced microbial C acquisition, whereas microbial N acquisition was strongly increased. These opposing grazing effects were also evident in the decomposition of standardized plant litter: The decomposition rate constant (k) and the stabilization (S) of litter were not inversely related, as would be expected, but instead both were reduced by livestock grazing. Our data suggest that gazing effects on EEAs and litter decomposition can just partly be explained by grazing-driven soil compaction and resulting lower oxygen availability, which has previously been hypothesized as a main pathway by which grazing can reduce microbial activity in wetland soils. Instead, grazing effects on microbial nutrient demand occurs to be an at least equally important control on soil decomposition processes.

The Nab experiment: A precision measurement of unpolarized neutron beta decay

Neutron beta decay is one of the most fundamental processes in nuclear physics and provides sensitive means to uncover the details of the weak interaction. Neutron beta decay can evaluate the ratio of axial-vector to vector coupling constants in the standard model, λ = gA/gV, through multiple decay correlations. The Nab experiment will carry out measurements of the electron-neutrino correlation parameter a with a precision of δa/a = 10−3 and the Fierz interference term b to δb = 3 × 10−3 in unpolarized free neutron beta decay. These results, along with a more precise measurement of the neutron lifetime, aim to deliver an independent determination of the ratio λ with a precision of δλ/λ = 0.03% that will allow an evaluation of Vud and sensitively test CKM unitarity, independent of nuclear models. Nab utilizes a novel, long asymmetric spectrometer that guides the decay electron and proton to two large area silicon detectors in order to precisely determine the electron energy and an estimation of the proton momentum from the proton time of flight. The Nab spectrometer is being commissioned at the Fundamental Neutron Physics Beamline at the Spallation Neutron Source at Oak Ridge National Lab. We present an overview of the Nab experiment and recent updates on the spectrometer, analysis, and systematic effects.

The neutron electric dipole moment experiment at the Spallation Neutron Source

Novel experimental techniques are required to make the next big leap in neutron electric dipole moment experimental sensitivity, both in terms of statistics and systematic error control. The nEDM experiment at the Spallation Neutron Source (nEDM@SNS) will implement the scheme of Golub & Lamoreaux [Phys. Rep., 237, 1 (1994)]. The unique properties of combining polarized ultracold neutrons, polarized 3He, and superfluid 4He will be exploited to provide a sensitivity to ∼ 10−28 e · cm. Our cryogenic apparatus will deploy two small (3 L) measurement cells with a high density of ultracold neutrons produced and spin analyzed in situ. The electric field strength, precession time, magnetic shielding, and detected UCN number will all be enhanced compared to previous room temperature Ramsey measurements. Our 3He co-magnetometer offers unique control of systematic effects, in particular the Bloch-Siegert induced false EDM. Furthermore, there will be two distinct measurement modes: free precession and dressed spin. This will provide an important self-check of our results. Following five years of “critical component demonstration,” our collaboration transitioned to a “large scale integration” phase in 2018. An overview of our measurement techniques, experimental design, and brief updates are described in these proceedings.

P4139Prediction of atrial fibrillation in embolic stroke of unknown source

Background

Atrial fibrillation (AF) is one of the leading cardiogenic causes for embolic stroke of unknown source (ESUS). Its incidence is growing with patients' age. Detection and rule out of AF is complex and cumbersome. The best method is an implantable loop recorder (ILR). In patients elder than 60 years, incidence of AF is reported incongruently and reliable patient characteristics that can predict a low or high risk for AF are scarce.

Purpose

This study reports real life incidences of AF in a group of patients undergoing ILR after ESUS. It aims to depict age dependency of AF and to identify potential confounding factors.

Methods

In a single center study, we analysed 111 patients (age=62±13 years, nmale=65) who received an ILR in our centre following ESUS. Patient characteristics, brain imaging, hemodynamic monitoring, blood pressure, electrocardiography, holter ecg and echocardiography data from the initial hospital stay and ILR follow-up over a mean of 460 days were analysed. Primary endpoint was the recording of AF during follow-up.

Results

AF was detected in 23% of all patients. Patients with AF were significantly elder than those without AF (p=0.01). Incidence of AF was in Patients <60y: 14%, 60–69y: 13%, 70–79y: 45%, >80y: 67%. We observed a significant difference in AF incidence comparing patients younger and elder than 70 years (p=0.034).

Both, CHADS-Vasc (p=0.036) and HATCH-scores (p=0.018) were higher in the AF group while the simple CHADS2 Score missed significance (p=0.068). PQ duration was longer in AF patients (p=0.022) and baseline heart rate at admission was lower (p=0.027). NIHSS scores were lower in the AF group at admission (2.97 vs. 4.10; p=0.049) but due to less neurological improvement in the AF group, this difference faded until dismission (1.09 vs 1.79 p=ns).

Conclusions

In our real life ILR group following ESUS, strongest predictor of AF was age. Pivot point rather was at 70 than at 60 years of age.

A simple dual-inducible CRISPR interference system for multiple gene targeting in Corynebacterium glutamicum

The development of CRISPR interference (CRISPRi) technology has dramatically increased the pace and the precision of target identification during platform strain development. In order to develop a simple, reliable, and dual-inducible CRISPRi system for the industrially relevant Corynebacterium glutamicum, we combined two different inducible repressor systems in a single plasmid to separately regulate the expression of dCas9 (anhydro-tetracycline-inducible) and a given single guide RNA (IPTG-inducible). The functionality of the resulting vector was demonstrated by targeting the l-arginine biosynthesis pathway in C. glutamicum. By co-expressing dCas9 and a specific single guide RNA targeting the 5'-region of the argininosuccinate lyase gene argH, the specific activity of the target enzyme was down-regulated and in a l-arginine production strain, l-arginine formation was shifted towards citrulline formation. The system was also employed for down-regulation of multiple genes by concatenating sgRNA sequences encoded on one plasmid. Simultaneous down-regulated expression of both argH and the phosphoglucose isomerase gene pgi proved the potential of the system for multiplex targeting. The system can be a promising tool for further pathway engineering in C. glutamicum. Cumulative effects on targeted genes can be rapidly evaluated avoiding tedious and time-consuming traditional gene knockout approaches.

High level in vivo mucin-type glycosylation in Escherichia coli

BACKGROUND

Increasing efforts have been made to assess the potential of Escherichia coli strains for the production of complex recombinant proteins. Since a considerable part of therapeutic proteins are glycoproteins, the lack of the post-translational attachment of sugar moieties in standard E. coli expression strains represents a major caveat, thus limiting the use of E. coli based cell factories. The establishment of an E. coli expression system capable of protein glycosylation could potentially facilitate the production of therapeutics with a putative concomitant reduction of production costs.

RESULTS

The previously established E. coli strain expressing the soluble form of the functional human-derived glycosyltransferase polypeptide N-acetylgalactosaminyltransferase 2 (GalNAc-T2) was further modified by co-expressing the UDP-GlcNAc 4-epimerase WbgU derived from Plesiomonas shigelloides. This enables the conversion of uridine 5'-diphospho-N-acetylglucosamine (UDP-GlcNAc) to the sugar donor uridine 5'-diphospho-N-acetylgalactosamine (UDP-GalNAc) in the bacterial cytoplasm. Initially, the codon-optimised gene wbgU was inserted into a pET-derived vector and a Tobacco Etch Virus (TEV) protease cleavable polyhistidine-tag was translationally fused to the C- terminus of the amino acid sequence. The 4-epimerase was subsequently expressed and purified. Following the removal of the polyhistidine-tag, WbgU was analysed by circular dichroism spectroscopy to determine folding state and thermal transitions of the protein. The in vitro activity of WbgU was validated by employing a modified glycosyltransferase assay. The conversion of UDP-GlcNAc to UDP-GalNAc was shown by capillary electrophoresis analysis. Using a previously established chaperone pre-/co- expression platform, the in vivo activity of both glycosyltransferase GalNAc-T2 and 4-epimerase WbgU was assessed in E. coli, in combination with a mucin 10-derived target protein. Monitoring glycosylation by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS), the results clearly indicated the in vivo glycosylation of the mucin-derived acceptor peptide.

CONCLUSION

In the present work, the previously established E. coli- based expression system was further optimized and the potential for in vivo O-glycosylation was shown by demonstrating the transfer of sugar moieties to a mucin-derived acceptor protein. The results offer the possibility to assess the practical use of the described expression platform for in vivo glycosylations of important biopharmaceutical compounds in E. coli.

Selective oxidative dehydrogenation of propane to propene using boron nitride catalysts

The exothermic oxidative dehydrogenation of propane reaction to generate propene has the potential to be a game-changing technology in the chemical industry. However, even after decades of research, selectivity to propene remains too low to be commercially attractive because of overoxidation of propene to thermodynamically favored CO₂ Here, we report that hexagonal boron nitride and boron nitride nanotubes exhibit unique and hitherto unanticipated catalytic properties, resulting in great selectivity to olefins. As an example, at 14% propane conversion, we obtain selectivity of 79% propene and 12% ethene, another desired alkene. Based on catalytic experiments, spectroscopic insights, and ab initio modeling, we put forward a mechanistic hypothesis in which oxygen-terminated armchair boron nitride edges are proposed to be the catalytic active sites.

Measurement of the hyperfine quenching rate of the clock transition in 171YB

We report the first experimental determination of the hyperfine quenching rate of the 6s(2) (1)S(0)(F = 1/2) - 6s6p (3)P(0)(F = 1/2) transition in (171)Yb with nuclear spin I = 1/2. This rate determines the natural linewidth and the Rabi frequency of the clock transition of a Yb optical frequency standard. Our technique involves spectrally resolved fluorescence decay measurements of the lowest lying (3)P(0,1) levels of neutral Yb atoms embedded in a solid Ne matrix. The solid Ne provides a simple way to trap a large number of atoms as well as an efficient mechanism for populating (3)P(0). The decay rates in solid Ne are modified by medium effects including the index-of-refraction dependence. We find the (3)P(0) hyperfine quenching rate to be (4.42 ± 0.35) × 10(-2) s(-1) for free (171)Yb, which agrees with recent ab initio calculations.

Chest CT findings in EBUS-TBNA-proven anthracosis in enlarged mediastinal lymph nodes

PURPOSE

We demonstrate the multislice computed tomography (MSCT) findings of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)-proven hilar and mediastinal lymph node enlargement with signs of anthracosis.

MATERIALS AND METHODS

53 enlarged lymph nodes in 39 patients (28 male, 11 female) with EBUS-TBNA-confirmed anthracosis were analyzed retrospectively.

RESULTS

The mean short axis diameter of the enlarged lymph nodes with signs of anthracosis was 13.7  mm. Lymph nodes most often showed an oval shape (84  %) and were well defined in 66  % of cases. Lymph node confluence was observed in 32  % of cases. Calcifications were documented in 24.5  % of cases. Contrast enhancement and fatty involution were seen seldom (3.8  %). Lymph node necrosis was not seen.

CONCLUSION

Lymph node anthracosis may be found most often in enlarged, well defined lymph nodes with an oval shape, frequently associated with confluence and calcifications.

Ion current as a precise measure of the loading rate of a magneto-optical trap

We have demonstrated that the ion current resulting from collisions between metastable krypton atoms in a magneto-optical trap can be used to precisely measure the trap loading rate. We measured both the ion current of the abundant isotope 83Kr (isotopic abundance=11%) and the single-atom counting rate of the rare isotope 85Kr (isotopic abundance∼1×10(-11)), and found the two quantities to be proportional at a precision level of 0.9%. This work results in a significant improvement in using the magneto-optical trap as an analytical tool for noble-gas isotope ratio measurements, and will benefit both atomic physics studies and applications in the earth sciences.

Cardiac disease in children and young adults with various lysosomal storage diseases: Comparison of echocardiographic and ECG changes among clinical groups

BACKGROUND

Lysosomal storage disease (LSD) is a rare inherited disease group. Consecutively there are few data on cardiac changes in mucopolysaccharidosis (MPS), Anderson Fabry disease (AFD), and other LSD (oLSD) including Pompe disease (PD) and Danon disease (DD), I-cell disease ICD and mucolipidosis III (ML III).

METHODS

Between 1994 and 2011, we identified 39 patients with LSD: 25 with MPS, 8 with AFD, and 6 with oLSD including PD (1), ML III (2), DD (1), and ICD (2) at our institution fulfilling the inclusion criteria of at least one echocardiogram and ECG.

RESULTS

Median age was 11.4 years (range: 2-27), 22 were females (56%). Normal echocardiograms were present in 12 patients (31%): 4 with MPS (16%), 7 AFD (88%), and 1 oLSD (17%). Valvular heart disease was present in 23 patients (59%) occurring more often in MPS (76%) and oLSD (67%) than in AFD (0%) (p < 0.001). The most common ECG abnormality was a short PR interval in 10 of 35 patients (29%) occurring in all LSD groups. Median follow-up was 5.8 (0.2-22.2) years showing diminished 5-year survival compared to an age-matched group. However, no patient died due to a cardiac cause and no cardiovascular intervention was necessary.

CONCLUSION

Echocardiographically detectable cardiovascular involvement in children with LSD is mostly confined to MPS and oLSD. Valve thickening in echo and a short PR interval in the ECG are the most frequent abnormalities. Routine repeat assessment is recommended in LSD. However, significant cardiac disease necessitating cardiac intervention is rare during a short follow-up.

Lipid phosphate phosphatase (LPP3) and vascular development

Lipid phosphate phosphatases (LPP) are integral membrane proteins with broad substrate specificity that dephosphorylate lipid substrates including phosphatidic acid, lysophosphatidic acid, ceramide 1-phosphate, sphingosine 1-phosphate, and diacylglycerol pyrophosphate. Although the three mammalian enzymes (LPP1-3) demonstrate overlapping catalytic activities and substrate preferences in vitro, the phenotypes of mice with targeted inactivation of the Ppap2 genes encoding the LPP enzymes reveal nonredundant functions. A specific role for LPP3 in vascular development has emerged from studies of mice lacking Ppap2b. A meta-analysis of multiple, large genome-wide association studies identified a single nucleotide polymorphism in PPAP2B as a novel predictor of coronary artery disease. In this review, we will discuss the evidence that links LPP3 to vascular development and disease and evaluate potential molecular mechanisms. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.

Optical excitation and decay dynamics of ytterbium atoms embedded in a solid neon matrix

Neutral ytterbium atoms embedded in solid neon qualitatively retain the structure of free atoms. Despite the atom-solid interaction, the 6s6p ³P(0) level is found to remain metastable with its lifetimes determined to be in the range of ten to hundreds of seconds. The atomic population can be almost completely transferred between the ground level and the metastable level via optical excitation and spontaneous decay. The dynamics of this process is examined and is used to explicitly demonstrate that the transition broadening mechanism is homogeneous.

Manipulation of culture conditions for BHK cell growth inhibition by IRF-1 activation

The activation of interferon-regulatory-factor-1 (IRF-1) hasbeen applied to regulate the cell growth of BHK cells. Theconstitutively expressed IRF-1-estrogen receptor fusion protein(IRF-1-hER) activated by the addition to the culture medium ofan estrogen analogue (estradiol), enabled IRF-1 to gain itstranscriptional activator function. By using a dicistronicstabilised self-selecting construct it was possible to controlcell proliferation. With the addition of 100 nM of estradiol at the beginning of the exponential phase, the IRF-1 activationled to a rapid cell growth inhibition. Two days after estradioladdition cell concentration was still maintained but a decreasein cell viability was observed. This cell response isindependent on clone (producer and non-producer) and culturesystem (static and stirred cultures). Specificrecombinant-protein productivity of the producer clone was notsignificantly altered. Control experiments confirmed that IRF-1activation effect was not due to the addition of estradiol per se, estradiol solvent or serum concentration. The extent ofcell growth inhibition is dependent on estradiol concentrationand estradiol addition time, although a decrease in cellviability was always observed. Reducing the time span ofestradiol exposure allowed the decrease in the cell viability tobe controlled and the stationary inhibited phase to be extended:when the time of contact between the cells and estradiol isreduced cell viability increases, archieving values similar tothose obtained if no estradiol is added. During this recoveryphase the cells passed two different phases: first a stationaryphase extension where cell growth was still inhibited, followedby an increase of cell concentration. The IRF-1 system isreversible. This pattern can be repeated for an extended period when estradiol addition and removal are repeated, showing acyclic response. Thus, it is possible to modulate the IRF-1effect by manipulating cycles of addition/removal of estradioland in this way the stationary phase can be maintained.