Individual lifetime benefit from low-dose colchicine in chronic coronary artery disease patients

Background

Low-dose colchicine reduces the risk of cardiovascular events in patients with chronic coronary artery disease (CAD), but the absolute benefit may vary between patients. Individual benefit from preventive therapies can be estimated using the guideline-recommended SMART-REACH model.

Purpose

This study aimed to assess the range of individual absolute 10-year and lifetime benefit from low-dose colchicine according to patient risk profile.

Methods

The SMART-REACH model was combined with the relative treatment effect of low-dose colchicine, and applied to all participants from the LoDoCo2 trial (n=5,522), and patients with chronic CAD from the UCC-SMART cohort (n=5,308). Individual treatment benefit was expressed as (i) 10-year absolute risk reductions (ARRs) for myocardial infarction, ischemic stroke, or cardiovascular death (MACE), and (ii) life-years gained free of MACE. Predictions were also performed for MACE plus ischemia-driven coronary revascularization (MACE+), through development of a new competing risk-adjusted lifetime prediction model in data from the REACH registry (n=14,522). Low-dose colchicine was compared to alternative intensive prevention goals, i.e. low density lipoprotein-cholesterol (LDL-c) reduction to <1.4 mmol/L, and systolic blood pressure (SBP) reduction to <130 mmHg.

Results

Median individual 10-year ARR for MACE from low-dose colchicine therapy was 4.6% (interquartile range [IQR] 3.6–6.0%), and median gain in life expectancy free of MACE was 2.0 (IQR 1.6–2.5) years. Median 10-year ARR for MACE+ was 8.6% (IQR 7.6–9.8%), and median gain in MACE+-free life expectancy was 3.4 (IQR 2.6–4.2) years. For intensified LDL-c and SBP reduction respectively, median 10-year ARRs were 3.0% (IQR 1.5–5.1%) and 1.7% (IQR 0.0–5.7%) for MACE, and 5.2% (IQR 2.5–8.7%) and 2.9% (IQR 0.0–9.5%) for MACE+. Median life-years gained from LDL-c and SBP reduction were 1.2 (IQR 0.6–2.1) and 0.7 (IQR 0.0–2.3) years free of MACE, and 1.8 (IQR 0.8–3.3) and 0.9 (IQR 0.0–3.4) years free of MACE+.

Conclusion

The individual absolute benefit from low-dose colchicine varies between patients. In an era where lipid- and blood pressure-lowering therapies are already routinely used, the benefits of low-dose colchicine are expected to be of at least similar magnitude to those of intensified LDL-c and SBP reduction in patients with chronic CAD.

Funding Acknowledgement

Type of funding sources: None.

Development of CMR-derived aortic stiffness parameters in patients with metabolic comorbidities after ST-segment elevation myocardial infarction

Background

Aortic stiffness has demonstrated an independent prediction of adverse cardiovascular events after ST-segment elevation myocardial infarction (STEMI) [1]. The general impact of the comorbidities diabetes mellitus (DM), chronic kidney disease (CKD), anemia on aortic stiffness is well known [2,3]. Therefore, the present study aimed to investigate the influence of metabolic comorbidities on cardiovascular magnetic resonance (CMR)-derived aortic parameters early and 6 months after STEMI.

Methods

From the prospective STEMI pathway, 161 patients (mean age: 63.7 years; 75% male) with initial CMR 5 days after STEMI were included. 105 patients pursued in a 6-month follow-up CMR. Aortic stiffness was assessed using different parameters: 1) pulse wave velocity (PWV) from velocity-encoded phase-contrast images, 2) aortic distensibility, and 3) radial strain from the ascending aorta obtained from cine images. DM was diagnosed when either pre-existing, HbA1c ≥6.5% at index hospitalization or 2-hour OGCT ≥200 mg/dl. CKD was present when glomeruli filtration rate (GFR) was less than 60 ml/min/m2, Anemia was defined according to WHO classifications.

Results

Of the 161 patients, 46 presented with anemia at admission, 79 with anemia at day 5, 26 with CKD and 57 with DM. Initial anemia resulted in a significantly lower distensibility (p=0.003) and aortic strain (p=0.02). A correlation between initial haemoglobin levels and distensibility (r=0.253; p=0.002) was found. CKD Patients showed a lower distensibility (p=0.012). There were correlations between GFR and PWV (r=−0.298; p<0.001), distensibility (r=0.370; p<0.001), and radial strain (r=−0.388; p<0.001). After 6 month this significant correlation remained. The DM group showed higher PWV values (p=0.02) and a lower radial strain (p=0.003). PWV showed a correlation with the 2-hour OGCT value (r=0.249; p=0.011) while the radial strain correlated with HbA1c (r=0.216; p=0.007). After multivariable analyses, diabetes remained the only significant predictor to show higher PWV (p=0.004) and poorer radial strain values (p=0.0045) while initial anemia remained the only significant predictor of lower distensibility (p=0.0033). Aortic stiffness parameters did not show any changes after 6 months in all groups. Only NTproBNP 5 days after STEMI correlated significantly with 6-months PWV (r=0.247; p=0.02), radial strain (r=0.36; p=0.001), distensibility (r=−0.226; p=0.018).

Conclusion

Anemia, DM and CKD show a detrimental impact on values of aortic stiffness early after STEMI. Diabetes remains the only significant predictor of higher PWV and poorer radial strain values after multivariable analysis while initial anemia remains significant predictor of lower distensibility. After 6 months none of the groups showed improvement in aortic stiffness parameters.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Sonderforschungsbereich 1116

Cross-modality analysis of left ventricular function and volume in patients with st-segment elevation myocardial infarction: impact of infarct patterns

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Sonderforschungsbereich 1116, University Düsseldorf

Background

Left ventricular (LV) function is considered of major importance to estimate prognosis of patients with ST-segment elevation myocardial infarction (STEMI) [1]. Although transthoracic echocardiography (TTE) after STEMI is recommended to assess for LV function and identify patients at high risk for rehospitalisation due to heart failure, Cardiovascular Magnetic Resonance (CMR) is still considered the gold standard for an adequate quantification of volumes, function and infarct size (IS) [2]. In addition, unenhanced TTE has been shown to underestimate LV function [3]. It is complicating that parameters such as IS and area-at risk (AAR) are thought to further deteriorate prognosis [4,5]. 

Purpose

To test the hypothesis that cross-modality 2D/3D analyses using TTE, CMR and cineventriculography are comparable for the determination of LV-function in STEMI and that infarct patterns influence the determination of LV-function and volumes across modalities.

Methods

In a group of 70 patients after STEMI, estimation of LV function and volumes was performed by biplane cineventriculography during acute catheterization, biplane (2D) CMR 28 ± 16 hours (1 day) as well as 2D/3D-CMR and TTE 114 ± 31 hours (5 days) post STEMI. 3D-TTE after STEMI was only performed in a subset of 36 patients respectively. IS and AAR were assessed by T2-weighted and contrast enhanced CMR (1.5T) as percentage of the LV mass. 

Results

Both, 2D- and 3D-, LV ejection fraction (LVEF) were comparable between the single modalities. Stroke volume (SV) and LV end-diastolic volume (LVEDV) were underestimated when comparing 2D- to 3D-CMR and when comparing TTE/cineventriculography to CMR.

Correlating IS to the difference of 2D- and 3D-CMR, higher IS/AAR did not alter previous results, except from a fairly increased difference in SV (R = 0.3). For 2D-TTE versus 2D-CMR, higher IS/AAR increased differences in LVEDV (IS & AAR: p <0.001 both, R = -0.58, R=-0.54). For 3D-TTE and 3D-CMR, IS and AAR increased the difference in LVEF (p = 0.009, R = 0.50; p < 0.001, R = 0.60) and LVEDV (p = 0.021, R=-0.5; p = 0.027, R=-0.46). A general linear model (GLM) for repeated measures including IS as covariate supported this finding by showing a significant interaction effect between the imaging modalities (TTE/CMR) for LVEF estimation and IS. AAR increased the difference in LVEF comparing cineventriculography and 2D-CMR as well (p = 0.001, R = 0.47). This was again supported by a significant interaction effect as detected by the GLM.

Conclusions

There is good agreement between LVEF analysis across dimensions (2D and 3D) and different modalities (TTE, cineventriculography and CMR) whereas the comparison of SV and LVEDV is hampered. However, with increasing IS or AAR, LVEF differences between modalities increase and 3D-CMR, if available, or alternatively 3D-TTE should be used for the most accurate estimation of LVEF.

Stochastic Analysis of ‘Simultaneous Merge–Sort'

The asymptotic behaviour of the recursion is investigated; Yk describes the number of comparisons which have to be carried out to merge two sorted subsequences of length 2k–1 and Mk can be interpreted as the number of comparisons of ‘Simultaneous Merge–Sort'. The challenging problem in the analysis of the above recursion lies in the fact that it contains a maximum as well as a sum. This demands different ideal properties for the metric in the contraction method. By use of the weighted Kolmogorov metric it is shown that an exponential normalization provides the recursion's convergence. Furthermore, one can show that any sequence of linear normalizations of Mk must converge towards a constant if it converges in distribution at all.

EVALUATION OF A METRIC CAMERA SYSTEM TAILORED FOR HIGH PRECISION UAV APPLICATIONS

In this paper we present the further evaluation of DLR’s modular airborne camera system MACS-Micro for small unmanned aerial vehicle (UAV). The main focus is on standardized calibration procedures and on photogrammetric workflows. The current prototype consists of an industrial grade frame imaging camera with 12 megapixel resolutions and a compact GNSS/IMU solution which are operated by an embedded computing unit (CPU). The camera was calibrated once pre-flight and several times post-flight over a period of 5 month using a three dimensional test field. The verification of the radiometric quality of the acquired images has been done under controlled static conditions and kinematic conditions testing different demosaicing methods. The validation of MACS-Micro is done by comparing a traditional photogrammetric evaluation with the workflows of Agisoft Photoscan and Pix4D Mapper. The analyses are based on an aerial survey of an urban environment using precise ground control points and acquired GNSS observations. Aerial triangulations with different configuratrions of ground control points (GCP’s) had been calculated, comparing the results of using a camera self-calibration and introducing fixed interior orientation parameters for Agisoft and Pix4D. The results are promising concerning the metric characteristics of the used camera and achieved accuracies in this test case. Further aspects have to be evaluated by further expanded test scenarios.

Practical Entanglement Estimation for Spin-System Quantum Simulators

We present practical methods to measure entanglement for quantum simulators that can be realized with trapped ions, cold atoms, and superconducting qubits. Focusing on long- and short-range Ising-type Hamiltonians, we introduce schemes that are applicable under realistic experimental conditions including mixedness due to, e.g., noise or temperature. In particular, we identify a single observable whose expectation value serves as a lower bound to entanglement and that may be obtained by a simple quantum circuit. As such circuits are not (yet) available for every platform, we investigate the performance of routinely measured observables as quantitative entanglement witnesses. Possible applications include experimental studies of entanglement scaling in critical systems and the reliable benchmarking of quantum simulators.

Simulating Bosonic Baths with Error Bars

We derive rigorous truncation-error bounds for the spin-boson model and its generalizations to arbitrary quantum systems interacting with bosonic baths. For the numerical simulation of such baths, the truncation of both the number of modes and the local Hilbert-space dimensions is necessary. We derive superexponential Lieb-Robinson-type bounds on the error when restricting the bath to finitely many modes and show how the error introduced by truncating the local Hilbert spaces may be efficiently monitored numerically. In this way we give error bounds for approximating the infinite system by a finite-dimensional one. As a consequence, numerical simulations such as the time-evolving density with orthogonal polynomials algorithm (TEDOPA) now allow for the fully certified treatment of the system-environment interaction.

Quantifying coherence

We introduce a rigorous framework for the quantification of coherence and identify intuitive and easily computable measures of coherence. We achieve this by adopting the viewpoint of coherence as a physical resource. By determining defining conditions for measures of coherence we identify classes of functionals that satisfy these conditions and other, at first glance natural quantities, that do not qualify as coherence measures. We conclude with an outline of the questions that remain to be answered to complete the theory of coherence as a resource.

Extracting entanglement from identical particles

Identical particles and entanglement are both fundamental components of quantum mechanics. However, when identical particles are condensed in a single spatial mode, the standard notions of entanglement, based on clearly identifiable subsystems, break down. This has led many to conclude that such systems have limited value for quantum information tasks, compared to distinguishable particle systems. To the contrary, we show that any entanglement formally appearing amongst the identical particles, including entanglement due purely to symmetrization, can be extracted into an entangled state of independent modes, which can then be applied to any task. In fact, the entanglement of the mode system is in one-to-one correspondence with the entanglement between the inaccessible identical particles. This settles the long-standing debate about the resource capabilities of such states, in particular spin-squeezed states of Bose-Einstein condensates, while also revealing a new perspective on how and when entanglement is generated in passive optical networks. Our results thus reveal new fundamental connections between entanglement, squeezing, and indistinguishability.

Scalable reconstruction of density matrices

Recent contributions in the field of quantum state tomography have shown that, despite the exponential growth of Hilbert space with the number of subsystems, tomography of one-dimensional quantum systems may still be performed efficiently by tailored reconstruction schemes. Here, we discuss a scalable method to reconstruct mixed states that are well approximated by matrix product operators. The reconstruction scheme only requires local information about the state, giving rise to a reconstruction technique that is scalable in the system size. It is based on a constructive proof that generic matrix product operators are fully determined by their local reductions. We discuss applications of this scheme for simulated data and experimental data obtained in an ion trap experiment.

[Quality of life, stress management and health promotion in medical and dental students. A comparative study]

OBJECTIVE

Which are the differences in health-related quality of life and stress management in medical and dental students?

METHODS

101 dental and 237 medical students from different years of Justus-Liebig University Giessen were examined during winter term 2008/09 and summer term 2009 using the specific Questionnaire on Health Promotion, Life Satisfaction, and Stress Management in Dental or Medical Students (addressing work satisfaction and choice of subject, private life, relaxation behavior and stress management, and health behavior), Beck Depression Inventory (BDI) and SF-36 Health Survey. For statistical analysis, Mann-Whitney-U-Test, analysis of variance (ANOVA), Pearson correlation and Chi2-Tests were primarily used.

RESULTS

Dental and medical students showed considerable mental impairment in SF-36. Every fifth dental student suffered from slight to moderate depression. Though averaging more hours per week, medical students were more satisfied with their studies. More than half of the dental and medical students did not have appropriate strategies of coping with stress.

CONCLUSIONS

Concerning the mental impairment in both groups and regarding a higher health-related quality of life, specific prevention courses or mentoring programs should already be offered at the beginning of medical training in order to cope with strains of medical school and future job strains in the medical or dental profession.

Interaction-dependent temperature effects in Bose-Fermi mixtures in optical lattices

We present a quantitative finite temperature analysis of a recent experiment with Bose-Fermi mixtures in optical lattices, in which the dependence of the coherence of bosons on the interspecies interaction was analyzed. Our theory reproduces the characteristics of this dependence and suggests that intrinsic temperature effects play an important role in these systems. Namely, under the assumption that the ramping up of the optical lattice is an isentropic process, adiabatic temperature changes of the mixture occur that depend on the interaction between bosons and fermions. Matching the entropy of two regimes-no lattice on the one hand and deep lattices on the other-allows us to compute the temperature in the lattice and the visibility of the quasimomentum distribution of the bosonic atoms, which we compare to the experiment.

Measuring entanglement in condensed matter systems

We show how entanglement may be quantified in spin and cold atom many-body systems using standard experimental techniques only. The scheme requires no assumptions on the state in the laboratory, and a lower bound to the entanglement can be read off directly from the scattering cross section of neutrons deflected from solid state samples or the time-of-flight distribution of cold atoms in optical lattices, respectively. This removes a major obstacle which so far has prevented the direct and quantitative experimental study of genuine quantum correlations in many-body systems: The need for a full characterization of the state to quantify the entanglement contained in it. Instead, the scheme presented here relies solely on global measurements that are routinely performed and is versatile enough to accommodate systems and measurements different from the ones we exemplify in this work.

Stability over 36 months of a new liquid 10% polyclonal immunoglobulin product (IgPro10, Privigen) stabilized with L-proline

BACKGROUND AND OBJECTIVES

IgPro10 (Privigen) is a new liquid intravenous immunoglobulin (IVIG) product that is formulated with 250 mM L-proline at pH 4.8. A 3-year study was performed to assess its stability.

MATERIALS AND METHODS

Physicochemical, biological and immunological parameters of Privigen were assessed during storage under controlled conditions over up to 36 months at 25 degrees C.

RESULTS

Privigen was shown to be stable after storage for 3 years at room temperature (25 degrees C). Of all parameters tested, only a few showed changes during storage. The appearance of the solution complied with the specifications given by the European Pharmacopeia over the full study period, with a single exception. The IgG fraction in Privigen displayed high purity (> or = 98%), which did not change during storage over 36 months. No relevant amounts of aggregated IgG molecules were formed in Privigen samples and the ratio between monomers and dimers shifted slightly towards the equilibrium over time. Testing of reference antibody contents and the Fc function demonstrated that the biological activity and effector functions of Privigen were preserved over the full study period of 36 months.

CONCLUSION

Thirty-six months room temperature stability of Privigen was achieved at pH 4.8 with an innovative formulation containing the physiological stabilizer L-proline.

Exploring local quantum many-body relaxation by atoms in optical superlattices

We establish a setting-atoms in optical superlattices with period 2-in which one can experimentally probe signatures of the process of local relaxation and apparent thermalization in nonequilibrium dynamics without the need of addressing single sites. This opens up a way to explore the convergence of subsystems to maximum entropy states in quenched quantum many-body systems with present technology. Remarkably, the emergence of thermal states does not follow from a coupling to an environment but is a result of the complex nonequilibrium dynamics in closed systems. We explore ways of measuring the relevant signatures of thermalization in this analogue quantum simulation of a relaxation process, exploiting the possibilities offered by optical superlattices.

Do mixtures of bosonic and fermionic atoms adiabatically heat up in optical lattices?

Mixtures of bosonic and fermionic atoms in optical lattices provide a promising arena to study strongly correlated systems. In experiments realizing such mixtures in the quantum-degenerate regime the temperature is a key parameter. We investigate the intrinsic heating and cooling effects due to an entropy-preserving raising of the optical lattice, identify the generic behavior valid for a wide range of parameters, and discuss it quantitatively for the recent experiments with 87Rb and 40K atoms. In the absence of a lattice, we treat the bosons in the Hartree-Fock-Bogoliubov-Popov approximation, including the fermions in a self-consistent mean-field interaction. In the presence of the full three-dimensional lattice, we use a strong coupling expansion. We find the temperature of the mixture in the lattice to be always higher than for the pure bosonic case, shedding light onto a key point in the analysis of recent experiments.

Exact relaxation in a class of nonequilibrium quantum lattice systems

A reasonable physical intuition in the study of interacting quantum systems says that, independent of the initial state, the system will tend to equilibrate. In this work we introduce an experimentally accessible setting where relaxation to a steady state is exact, namely, for the Bose-Hubbard model quenched from a Mott quantum phase to the free strong superfluid regime. We rigorously prove that the evolving state locally relaxes to a steady state with maximum entropy constrained by second moments--thus maximizing the entanglement. Remarkably, for this to be true, no time average is necessary. Our argument includes a central limit theorem and exploits the finite speed of information transfer. We also show that for all periodic initial configurations (charge density waves) the system relaxes locally, and identify experimentally accessible signatures in optical lattices as well as implications for the foundations of statistical mechanics.

Statistics dependence of the entanglement entropy

The entanglement entropy of a distinguished region of a quantum many-body system reflects the entanglement in its pure ground state. Here we establish scaling laws for this entanglement in critical quasifree fermionic and bosonic lattice systems, without resorting to numerical means. We consider the setting of D-dimensional half-spaces which allows us to exploit a connection to the one-dimensional case. Intriguingly, we find a difference in the scaling properties depending on whether the system is bosonic-where an area law is proven to hold-or fermionic where we determine a logarithmic correction to the area law, which depends on the topology of the Fermi surface. We find Lifshitz quantum phase transitions accompanied with a nonanalyticity in the prefactor of the leading order term.

[Health-related quality of life in dermatologists compared to other physicians]

BACKGROUND

According to recent studies, there may be differences in quality of life for physicians depending on gender and field of medicine. Presently, there are hardly any data with respect to health-related quality of life in dermatologists.

METHODS

Using the SF-36 Health Survey, 112 dermatologists and 113 physicians in other fields of medicine were studied in a cross-sectional study.

RESULTS

Dermatologists' mental health level averaged lower than their physical health level (chi2=28.49; p<.001). The mental and physical health level were higher in female dermatologists than in their male colleagues (e.g., GH: chi2=6.15; p<.05 and MH: chi2=6.83; p<.05). These findings are the opposite of results in other medical specialists. The differences between mental and physical health dimensions on the one hand, and between women and men on the other hand, were found in all age groups.

CONCLUSIONS

In comparison to other medical specialists, dermatologists differ only slightly in their health-related quality of life. Therefore, it may be advisable to implement preventive measures concerning their comparatively low mental health status.

Biphenyl-indanones: allosteric potentiators of the metabotropic glutamate subtype 2 receptor

We have identified and synthesized a series of biphenyl-carboxylic acid indanones as allosteric potentiators of the metabotropic glutamate receptor 2. Structure-activity relationship studies directed toward improving the potency and the brain to plasma ratio of the initial lead led to the discovery of 5 and 23 (EC50=111 and 5 nM, respectively).

3-[Substituted]-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitriles: Identification of highly potent and selective metabotropic glutamate subtype 5 receptor antagonists

Structure-activity relationship studies on the phenyl ring of 3-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile 2 led to the discovery that small, non-hydrogen bond donor substituents at the 3-position led to a substantial increase in in vitro potency. In particular, 3-fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile (7) is a highly potent and selective mGlu5 receptor antagonist with good rat pharmacokinetics, brain penetration, and in vivo receptor occupancy.

Water soluble prodrug of a COX-2 selective inhibitor suitable for intravenous administration in models of cerebral ischemia

A water soluble choline prodrug (17) of a COX-2 selective inhibitor (16) suitable for intravenous dosing in models of cerebral ischemia has been developed. Constant infusion studies using 17 demonstrate that extrapolated brain levels of 16 may be maintained for over 24h in rats.

Cyclohexenyl- and dehydropiperidinyl-alkynyl pyridines as potent metabotropic glutamate subtype 5 (mGlu5) receptor antagonists

Structure-activity relationship studies leading to the discovery of novel mGlu5 receptor antagonists are described. These compounds show high in vitro potency, have good in vivo receptor occupancy, and a reasonable intravenous pharmacokinetic profile.

In vitro metabolic studies on the selective metabotropic glutamate receptor sub-type 5 (mGluR5) antagonist 3-[(2-methyl-1,3-thiazol-4-yl) ethynyl]-pyridine (MTEP)

Metabotropic glutamate receptors (mGluR) are G-protein-coupled receptors that play a major role in modulatory pathways in the CNS and have been suggested to have pharmacological implications in pain, psychiatric disorders and other neurological states. 3-[(2-Methyl-1,3-thiazol-4-yl) ethynyl]-pyridine (MTEP) is a specific and selective antagonist for the mGluR sub-type 5. Previous studies using rat liver microsomes showed that the major oxidative metabolites of MTEP are a hydroxymethyl metabolite (M1), two oxides (M2 and M4), a thiazole-ring opened metabolite (M3) and CO(2) (M5). In the present study, we examined the metabolism of MTEP in liver microsomes and expressed rat and human CYP isoforms. In rat liver microsomes, metabolic stability studies accurately predicted the in vivo clearance for MTEP. Incubation of MTEP with expressed rat and human CYP isoforms showed that CYP1A and CYP2C isoforms are primarily responsible for the metabolism of this compound. The results suggest that species differences in MTEP metabolism is possible and could contribute to specie-differences in biological effects of the compound.

Influence of acid surrogates toward potency of VLA-4 antagonist

A series of VLA-4 antagonist were synthesized wherein carboxylic acid was replaced by various acid surrogates. The effect of these acid surrogates toward potency was evaluated in a binding assay. A number of acid surrogates were potent antagonist of VLA-4, albeit significantly less potent than the corresponding carboxylic acid. Heterocyclic acid surrogate, oxadiazolidinone 3, demonstrated an improved pharmacokinetic property when dosed intravenously.

METABOLISM AND DISPOSITION OF A POTENT GROUP II METABOTROPIC GLUTAMATE RECEPTOR AGONIST, IN RATS, DOGS, AND MONKEYS

Metabolism and disposition of MGS0028 [(1R,2S,5S,6S)-2-amino-6-fluoro-4-oxobicyclo[3.1.0]hexane-2,6-dicarboxylic acid monohydrate], a potent group II metabotropic glutamate receptor agonist, were examined in three preclinical species (Sprague-Dawley rats, beagle dogs, and rhesus monkeys). In rats, MGS0028 was widely distributed and primarily excreted in urine as parent and as a single reductive metabolite, identified as the 4R-isomer MGS0034 [(1R,2S,4R,5S,6S)-2-amino-6-fluoro-4-hydroxybicyclo[3.1.0]-hexane-2,6-dicarboxylic acid]. MGS0028 had a low brain to plasma ratio at efficacious doses in rats and was eliminated more slowly in rat brain than in plasma. Exposure increased proportionally (1--10 mg/kg p.o.) in rats, with bioavailability>60% at all doses. However, bioavailability was only approximately 20% in monkeys, and MGS0034 was found in relatively high abundance in plasma. In dogs, oral bioavailability was >60%, and the metabolite was not detected. In vitro metabolism was examined in liver subcellular fractions (microsomes and cytosol) from rat, dog, monkey, and human. Reductive metabolism was observed in rat, monkey, and human liver cytosol incubations, but not in dog liver cytosol incubations. No metabolism of MGS0028 was detected in incubations with liver microsomes from any species. Similar to in vivo results, MGS0028 was reduced in cytosol stereospecifically to MGS0034. The rank order of in vitro metabolite formation (monkey >> rat approximately human >> dog) was in agreement with in vivo observations in rats, dogs, and monkeys. Based on the observation of species difference in reductive metabolism, rat and monkey were recommended to be the preclinical species for further characterization prior to testing in humans. Finally, allometric scaling predicts that human pharmacokinetic parameters would be acceptable for further development.

5-[(2-Methyl-1,3-thiazol-4-yl)ethynyl]-2,3'-bipyridine: a highly potent, orally active metabotropic glutamate subtype 5 (mGlu5) receptor antagonist with anxiolytic activity

Structure-activity relationship studies leading to the discovery of a new, orally active mGlu5 receptor antagonist are described. The title compound, 5-[(2-methyl-1,3-thiazol-4-yl)ethynyl]-2,3'-bipyridine, is highly potent in vitro, has good in vivo receptor occupancy, and is efficacious in the rat fear-potentiated startle model of anxiety following oral dosing.

Entropy, entanglement, and area: analytical results for harmonic lattice systems

We revisit the question of the relation between entanglement, entropy, and area for harmonic lattice Hamiltonians corresponding to discrete versions of real free Klein-Gordon fields. For the ground state of the d-dimensional cubic harmonic lattice we establish a strict relationship between the surface area of a distinguished hypercube and the degree of entanglement between the hypercube and the rest of the lattice analytically, without resorting to numerical means. We outline extensions of these results to longer ranged interactions, finite temperatures, and for classical correlations in classical harmonic lattice systems. These findings further suggest that the tools of quantum information science may help in establishing results in quantum field theory that were previously less accessible.

Inhomogeneous atomic Bose-Fermi mixtures in cubic lattices

We determine the ground state properties of inhomogeneous mixtures of bosons and fermions in cubic lattices and parabolic confining potentials. For finite hopping we determine the domain boundaries between Mott-insulator plateaux and hopping-dominated regions for lattices of arbitrary dimension within mean-field and perturbation theory. The results are compared with a new numerical method that is based on a Gutzwiller variational approach for the bosons and an exact treatment for the fermions. The findings can be applied as a guideline for future experiments with trapped atomic Bose-Fermi mixtures in optical lattices.

3-[3-Fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)phenyl]-4-methylpyridine: a highly potent and orally bioavailable metabotropic glutamate subtype 5 (mGlu5) receptor antagonist

Structure-activity relationship studies performed around 3-fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile for the purpose of developing novel mGlu5 receptor antagonists are described. Synthesis of a series of four-ring tetrazoles led to the discovery of 3-[3-fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)phenyl]-4-methylpyridine, a highly potent, brain penetrant, azole-based mGlu5 receptor antagonist.

2-{2-[3-(Pyridin-3-yloxy)phenyl]-2H-tetrazol-5-yl}pyridine: a highly potent, orally active, metabotropic glutamate subtype 5 (mGlu5) receptor antagonist

Structure-activity relationship studies on 3-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile 2 led to the discovery of 2-(2-[3-(pyridin-3-yloxy)phenyl]-2H-tetrazol-5-yl)pyridine (10)-a highly potent and selective mGlu5 receptor antagonist with good brain penetration and in vivo receptor occupancy in rat and cross-species oral bioavailability.

Discovery of highly potent, selective, orally bioavailable, metabotropic glutamate subtype 5 (mGlu5) receptor antagonists devoid of cytochrome P450 1A2 inhibitory activity

Structure-activity relationship studies focused on bio-isosteric replacements of 2-pyridyl resulted in mGlu5 receptor antagonists with reduced inhibition of cytochrome P450 1A2. This led to highly potent, selective and orally bioavailable 2-imidazolyl tetrazoles such as (10) that are devoid of cytochrome P450 inhibitory activity.

Synthesis and biological evaluation of 6-aryl-6 H -pyrrolo[3,4- d ]pyridazine derivatives: high-affinity ligands to the α 2 δ subunit of voltage gated calcium channels

A novel class of 6-aryl-6H-pyrrolo[3,4-d]pyridazine ligands for the alpha2delta subunit of voltage-gated calcium channels has been described. Substitutions in the aryl ring of the molecule were generally not tolerated, and resulted in diminished binding to the alpha2delta subunit. Modifications to the pyridazine ring revealed numerous permissive substitutions, and detailed SAR studies were carried out in this portion of the molecule. Replacement of the pyridazine ring methyl group with an aminomethyl functionality provided greatly improved potency over the initial lead. The initial lead compound displayed good rat pharmacokinetic properties, and was shown to be efficacious in the Chung model for neuropathic pain in rats.

[Multislice CT of the pelvis: dose reduction with regard to image quality]

PURPOSE

To optimize the examination protocols of multislice CT (MSCT) of the pelvis for dose reduction with regard to image quality.

MATERIALS AND METHODS

MSCT of the pelvis was performed on 5 cadaver specimens with stepwise reduction of the tube current at 140 kV (250, 200, 150, 100, 75, 50, 35, 25 mAs) and 120 kV (50, 27 mAs). The remaining scan parameters like collimation (4 x 1 mm) and table speed of 4 mm per rotation remained unchanged. Axial sections and coronal reconstructions were used to evaluate cortex, trabecular structures, subjective image quality, image noise and detail detectability (pelvis and SI joint), with evaluation performed independently by four blinded experienced radiologists on a 5-point scale. Kappa coefficient, accuracy of the observers to sort the films with regard to dose reduction and mean scores of image evaluation were determined for statistical analysis.

RESULTS

The deterioration of the image quality was most pronounced for all criteria between 75 mAs and 50 mAs at 140 kV. Good results with adequate image quality were obtained for detail detectability at 50 mAs and 140 kV (effective dose [E]: 3.3 mSv) and for the remaining four criteria at 75 mAs (E: 4.9 mSv). There was a moderate agreement between the four observers (kappa coefficient: 0.27). All observers were excellent in arranging the images according to the increasing dose reduction.

CONCLUSIONS

Image quality of MSCT of the pelvis appears to be acceptable at 75 mAs and 140 kV with the dose reduced to 46% of the average value of the nation-wide survey of the German Roentgen Society in 1999 for this type of examination.

Prospective assessment of falls in Parkinson's disease

We studied prospectively the epidemiology, clinical impact and prediction of falls in 59 moderately affected patients with Parkinson's disease (PD) (mean UPDRS motor score 31.5; mean age 61 years) and 55 controls (mean age 60 years). At baseline, balance and gait were evaluated extensively. The retropulsion test (response to sudden shoulder pull) was executed first unexpectedly and five more times following prior warning. All persons used standardised scoring forms to document their falls during six months. Thirty patients (50.8 %) and eight controls (14.5%) fell at least once (relative risk [RR] 6.1; 95% confidence interval [CI] 2.5-15.1, p < 0.001). Recurrent (> or = 2) falls occurred in 15 patients (25.4%), but in only two controls (RR 9.0; 95 % CI 2.0-41.7; p=0.001). Recurrent falls were more common among persons taking benzodiazepines (RR 5.0; 95% CI 1.6-15.5; p < 0.01). Sixty-two percent of the falls in patients caused soft tissue injuries, but no fractures occurred. A fear of future falls was common (45.8 % of patients) and was accompanied by restriction of daily activities (44.1 % of patients). Seventy percent of falls reported by patients were'intrinsic' (due to patient-related factors), but falls in controls were mainly (50%) 'extrinsic' (due to environmental factors). None of the baseline posture and gait variables predicted falls adequately. The first 'unexpected' retropulsion test was more often abnormal than all subsequent (predictable) tests. Irrespective of its method of execution, the retropulsion test did not predict falls. A combination of asking for prior falls, disease severity and the Romberg test yielded the best overall diagnostic utility (sensitivity 65 % and specificity 98 %). Recurrent fallers were best predicted by disease severity (RR for Hoehn and Yahr stage 3 was > 100; 95% CI 3.1-585) and asking for prior falls (RR 5.0; 95% CI 1.2-20.9). We conclude that falls are common and disabling, even in relatively early stage PD. Recurrent fallers were best predicted by disease severity and presence of prior falls. Strategies to prevent falls in PD should particularly focus at intrinsic (patient-related) factors, such as minimising the use of benzodiazepines.

Perceived health needs of urban African American church congregants

Theory-based assessment of congregant expectations and needs should be conducted prior to beginning a parish nurse program. However, no such assessments are found in the literature. Using Andersen's Health Access Model as a framework, investigators conducted interviews with 117 randomly selected congregants in five urban African American churches to describe their perceived needs and expectations. Causing most concern were the following: (a) symptoms of illness--high blood pressure (50.4%), dental problems (43.6%), and back pain (41%); and (b) health habits/risks--weight (75%), exercise (63%), and diet (63%). Younger adults were significantly more concerned about all aspects of their health than their older counterparts. Women were significantly more likely to express concern about health habits and health risks than males. No significant relationship was found between perceived need and access to care. Although terming health care services "adequate", congregants expressed many unmet health needs. This seemingly contradictory finding may illuminate a concrete role for the parish nurse, i.e., addressing personal health care concerns not alleviated by the current "adequate" health care delivery system. This study's significance lies not only in providing programming guidance, but also in theoretical insights into the role of the parish nurse.