Isolated CMV infection causing perianal and sacral ulceration in a patient with aids.

Cytomegalovirus (CMV) is a DNA virus estimated to infect 70-90% of the world’s population, producing minimal symptoms in immunocompetent hosts. In the immunocompromised host, CMV infection can be potentially fatal, producing systemic or localized forms. We report the case of a 52-year-old female with acquired immunodeficiency virus (AIDS) who presented multiple sacral and perineal ulcers clinically and histopathologically consistent with CMV ulcerations. We discuss the patient’s clinical presentation and histologic findings to remind physicians to consider CMV as a cause for cutaneous and systemic infection in the immunocompromised host.

All-Optical Reconstruction of Crystal Band Structure.

The band structure of matter determines its properties. In solids, it is typically mapped with angle-resolved photoemission spectroscopy, in which the momentum and the energy of incoherent electrons are independently measured. Sometimes, however, photoelectrons are difficult or impossible to detect. Here we demonstrate an all-optical technique to reconstruct momentum-dependent band gaps by exploiting the coherent motion of electron-hole pairs driven by intense midinfrared femtosecond laser pulses. Applying the method to experimental data for a semiconductor ZnO crystal, we identify the split-off valence band as making the greatest contribution to tunneling to the conduction band. Our new band structure measurement technique is intrinsically bulk sensitive, does not require a vacuum, and has high temporal resolution, making it suitable to study reactions at ambient conditions, matter under extreme pressures, and ultrafast transient modifications to band structures.

Theoretical analysis of high-harmonic generation in solids.

We investigate theoretically high-harmonic generation (HHG) in bulk crystals exposed to intense midinfrared lasers with photon energies smaller than the band gap. The two main mechanisms, interband and intraband HHG, are explored. Our analysis indicates that the interband current neglected so far is the dominant mechanism for HHG. Saddle point analysis in the Keldysh limit yields an intuitive picture of interband HHG in solids similar to atomic HHG. Interband and intraband HHG exhibit a fundamentally different wavelength dependence. This signature can be used to experimentally distinguish between the two mechanisms in order to verify their importance.

The structure of CO2 hydrate between 0.7 and 1.0 GPa.

A deuterated sample of CO2 structure I (sI) clathrate hydrate (CO2·8.3 D2O) has been formed and neutron diffraction experiments up to 1.0 GPa at 240 K were performed. The sI CO2 hydrate transformed at 0.7 GPa into the high pressure phase that had been observed previously by Hirai et al. [J. Phys. Chem. 133, 124511 (2010)] and Bollengier et al. [Geochim. Cosmochim. Acta 119, 322 (2013)], but which had not been structurally identified. The current neutron diffraction data were successfully fitted to a filled ice structure with CO2 molecules filling the water channels. This CO2+water system has also been investigated using classical molecular dynamics and density functional ab initio methods to provide additional characterization of the high pressure structure. Both models indicate the water network adapts a MH-III "like" filled ice structure with considerable disorder of the orientations of the CO2 molecule. Furthermore, the disorder appears to be a direct result of the level of proton disorder in the water network. In contrast to the conclusions of Bollengier et al., our neutron diffraction data show that the filled ice phase can be recovered to ambient pressure (0.1 MPa) at 96 K, and recrystallization to sI hydrate occurs upon subsequent heating to 150 K, possibly by first forming low density amorphous ice. Unlike other clathrate hydrate systems, which transform from the sI or sII structure to the hexagonal structure (sH) then to the filled ice structure, CO2 hydrate transforms directly from the sI form to the filled ice structure.

Cage occupancies in the high pressure structure H methane hydrate: a neutron diffraction study.

A neutron diffraction study was performed on the CD(4) : D(2)O structure H clathrate hydrate to refine its CD(4) fractional cage occupancies. Samples of ice VII and hexagonal (sH) methane hydrate were produced in a Paris-Edinburgh press and in situ neutron diffraction data collected. The data were analyzed with the Rietveld method and yielded average cage occupancies of 3.1 CD(4) molecules in the large 20-hedron (5(12)6(8)) cages of the hydrate unit cell. Each of the pentagonal dodecahedron (5(12)) and 12-hedron (4(3)5(6)6(3)) cages in the sH unit cell are occupied with on average 0.89 and 0.90 CD(4) molecules, respectively. This experiment avoided the co-formation of Ice VI and sH hydrate, this mixture is more difficult to analyze due to the proclivity of ice VI to form highly textured crystals, and overlapping Bragg peaks of the two phases. These results provide essential information for the refinement of intermolecular potential parameters for the water-methane hydrophobic interaction in clathrate hydrates and related dense structures.

Synthesis and characterization of a new structure of gas hydrate.

Atoms and molecules <0.9 nm in diameter can be incorporated in the cages formed by hydrogen-bonded water molecules making up the crystalline solid clathrate hydrates. For these materials crystallographic structures generally fall into 3 categories, which are 2 cubic forms and a hexagonal form. A unique clathrate hydrate structure, previously known only hypothetically, has been synthesized at high pressure and recovered at 77 K and ambient pressure in these experiments. These samples contain Xe as a guest atom and the details of this previously unobserved structure are described here, most notably the host-guest ratio is similar to the cubic Xe clathrate starting material. After pressure quench recovery to 1 atmosphere the structure shows considerable metastability with increasing temperature (T <160 K) before reverting back to the cubic form. This evidence of structural complexity in compositionally similar clathrate compounds indicates that the reaction path may be an important determinant of the structure, and impacts upon the structures that might be encountered in nature.

Joint Position Paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology (SFC) and the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) on magnetic resonance imaging in patients with cardiac electronic implantable devices.

Magnetic resonance imaging (MRI) has become the reference imaging for the management of a large number of diseases. The number of MR examinations increases every year, simultaneously with the number of patients receiving a cardiac electronic implantable device (CEID). A CEID was considered an absolute contraindication for MRI for years. The progressive replacement of conventional pacemakers and defibrillators by MR-conditional CEIDs and recent data on the safety of MRI in patients with "MR-nonconditional" CEIDs have progressively increased the demand for MRI in patients with a CEID. However, some risks are associated with MRI in CEID carriers, even with "MR-conditional" devices because these devices are not "MR-safe". A specific programing of the device in "MR-mode" and monitoring patients during MRI remain mandatory for all patients with a CEID. A standardized patient workflow based on an institutional protocol should be established in each institution performing such examinations. This joint position paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) describes the effect and risks associated with MRI in CEID carriers. We propose recommendations for patient workflow and monitoring and CEID programming in MR-conditional, "MR-conditional nonguaranteed" and MR-nonconditional devices.

Structural Memory in Pressure-Amorphized AlPO4.

Molecular dynamics simulations reveal the mechanism of the structural memory effect in alpha-berlinite (AlPO(4)), where a single crystal transforms to an amorphous solid by compression and then reverts to the original crystalline structure upon release of pressure. The enhanced oxygen coordination around the aluminum atoms in AlPO(4) at high pressure leads to a mechanical instability that causes the phase transformation. The difference in the structural memory behavior between AlPO(4) and isostructural alpha-quartz, for which the pressure-induced amorphized phase is recoverable, can be attributed to the presence of the PO(4) units, which remain essentially four-coordinated even when severely distorted.

Cardiometabolic assessment of lamin A/C gene mutation carriers: a phenotype-genotype correlation.

AIMS: Mutations of the LMNA gene encoding lamin A/C induce heterogeneous phenotypes ranging from cardiopathies and myopathies to lipodystrophies. The aim of this study was to compare cardiometabolic complications in patients with heterozygous LMNA mutations at the 482nd codon, the 'hotspot' for partial lipodystrophy, with carriers of other, non-R482 LMNA mutations. METHODS AND RESULTS: This study included 29 patients with R482 LMNA mutations, 29 carriers of non-R482 LMNA mutation and 19 control subjects. Cardiac and metabolic phenotypes were compared between groups. A family history of either cardiac implantable electronic devices (CIEDs; P < 0.001) or sudden death (P < 0.01) was more frequent in non-R482 than R482 carriers. The non-R482 carriers also had more abnormalities on electrocardiography and received CIEDs more often than R482 carriers (P < 0.001). On cardiac ultrasound, non-R482 patients had greater frequencies of left atrial enlargement (P < 0.05) and lower left ventricular ejection fractions (P < 0.01) than R482 carriers. In contrast, R482 carriers had lower BMI (P < 0.05), leptin (P < 0.01) and fat mass (P < 0.001), but higher intra-/total abdominal fat-mass ratios (P < 0.001) and prevalences of diabetes (P < 0.01) and hypertriglyceridaemia (P < 0.05) than non-R482 carriers, with a trend towards more coronary artery disease. However, non-R482 carriers had higher intra-/total abdominal fat-mass ratios (P < 0.02) and prevalences of diabetes (P < 0.001) and hypertriglyceridaemia (P < 0.05) than the controls. CONCLUSION: Non-R482 carriers present more frequently with arrhythmias than R482 carriers, who twice as often have diabetes, suggesting that follow-up for laminopathies could be adjusted for genotype. Non-R482 mutations require ultra-specialized cardiac follow-up, and coronary artery disease should not be overlooked. Although overlapping phenotypes are found, LMNA mutations essentially lead to tissue-specific diseases, favouring genotype-specific pathophysiological mechanisms.

Spatially selective sampling of single cells using optically trapped fusogenic emulsion droplets: a new single-cell proteomic tool.

We present a platform for the spatially selective sampling of the plasma membrane of single cells. Optically trapped lipid-coated oil droplets (smart droplet microtools, SDMs), typically 0.5-5 microm in size, composed of a hexadecane hydrocarbon core and fusogenic lipid outer coating (mixture of 1,2-dioleoyl-phosphatidylethanolamine and 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine) were brought into controlled contact with target colon cancer cells leading to the formation of connecting membrane tethers. Material transfer from the cell to the SDM across the membrane tether was monitored by tracking membrane-localized enhanced green fluorescent protein.

Equation of state, phonons, and lattice stability of ultrafast warm dense matter.

Using the two-temperature model for ultrafast matter (UFM), we compare the equation of state, pair-distribution functions g(r), and phonons using the neutral pseudoatom (NPA) model with results from density functional theory (DFT) codes and molecular dynamics (MD) simulations for Al, Li, and Na. The NPA approach uses state-dependent first-principles pseudopotentials from an "all-electron" DFT calculation with finite-T exchange-correlation functional (XCF). It provides pair potentials, structure factors, the "bound" and "free" states, as well as a mean ionization Z[over ¯] unambiguously. These are not easily accessible via DFT+MD calculations which become prohibitive for T/T_{F} exceeding ∼0.6, where T_{F} is the Fermi temperature. Hence, both DFT+MD and NPA methods can be compared up to ∼8eV, while higher T can be addressed via the NPA. The high-T_{e} phonon calculations raise the question of UFM lattice stability and surface ablation in thin UFM samples. The ablation forces in a UFM slab are used to define an "ablation time" competing with phonon formation times in thin UFM samples. Excellent agreement for all properties is found between NPA and standard DFT codes, even for Li where a strongly nonlocal pseudopotential is used in DFT codes. The need to use pseudopotentials appropriate to the ionization state Z[over ¯] is emphasized. The effect of finite-T XCF is illustrated via its effect on the pressure and the electron-density distribution at a nucleus.

Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime.

We study the conductivities σ of (i) the equilibrium isochoric state σ_{is}, (ii) the equilibrium isobaric state σ_{ib}, and also the (iii) nonequilibrium ultrafast matter state σ_{uf} with the ion temperature T_{i} less than the electron temperature T_{e}. Aluminum, lithium, and carbon are considered, being increasingly complex warm dense matter systems, with carbon having transient covalent bonds. First-principles calculations, i.e., neutral-pseudoatom (NPA) calculations and density-functional theory (DFT) with molecular-dynamics (MD) simulations, are compared where possible with experimental data to characterize σ_{ic}, σ_{ib}, and σ_{uf}. The NPA σ_{ib} is closest to the available experimental data when compared to results from DFT with MD simulations, where simulations of about 64-125 atoms are typically used. The published conductivities for Li are reviewed and the value at a temperature of 4.5 eV is examined using supporting x-ray Thomson-scattering calculations. A physical picture of the variations of σ with temperature and density applicable to these materials is given. The insensitivity of σ to T_{e} below 10 eV for carbon, compared to Al and Li, is clarified.

Pair potentials for warm dense matter and their application to x-ray Thomson scattering in aluminum and beryllium.

Ultrafast laser experiments yield increasingly reliable data on warm dense matter, but their interpretation requires theoretical models. We employ an efficient density functional neutral-pseudoatom hypernetted-chain (NPA-HNC) model with accuracy comparable to ab initio simulations and which provides first-principles pseudopotentials and pair potentials for warm-dense matter. It avoids the use of (i) ad hoc core-repulsion models and (ii) "Yukawa screening" and (iii) need not assume ion-electron thermal equilibrium. Computations of the x-ray Thomson scattering (XRTS) spectra of aluminum and beryllium are compared with recent experiments and with density-functional-theory molecular-dynamics (DFT-MD) simulations. The NPA-HNC structure factors, compressibilities, phonons, and conductivities agree closely with DFT-MD results, while Yukawa screening gives misleading results. The analysis of the XRTS data for two of the experiments, using two-temperature quasi-equilibrium models, is supported by calculations of their temperature relaxation times.

Notched T waves on Holter recordings enhance detection of patients with LQt2 (HERG) mutations.

BACKGROUND: The 2 genes KCNQ1 (LQT1) and HERG (LQT2), encoding cardiac potassium channels, are the most common cause of the dominant long-QT syndrome (LQTS). In addition to QT-interval prolongation, notched T waves have been proposed as a phenotypic marker of LQTS patients. METHODS AND RESULTS: The T-wave morphology of carriers of mutations in KCNQ1 (n=133) or HERG (n=57) and of 100 control subjects was analyzed from Holter ECG recordings. Averaged T-wave templates were obtained at different cycle lengths, and potential notched T waves were classified as grade 1 (G1) in case of a bulge at or below the horizontal, whatever the amplitude, and as grade 2 (G2) in case of a protuberance above the horizontal. The highest grade obtained from a template defined the notch category of the subject. T-wave morphology was normal in the majority of LQT1 and control subjects compared with LQT2 (92%, 96%, and 19%, respectively, P:<0.001). G1 notches were relatively more frequent in LQT2 (18% versus 8% [LQT1] and 4% [control], P:<0.01), and G2 notches were seen exclusively in LQT2 (63%). Predictors for G2 were young age, missense mutations, and core domain mutations in HERG. CONCLUSIONS: This study provides novel evidence that Holter recording analysis is superior to the 12-lead ECG in detecting G1 and G2 T-wave notches. These repolarization abnormalities are more indicative of LQT2 versus LQT1, with G2 notches being most specific and often reflecting HERG core domain missense mutations.

Factors affecting epicardial dispersion of repolarization: a mapping study in the isolated porcine heart.

OBJECTIVE: Non-uniform drug-induced prolongation of repolarization predominating in the midmyocardial (M) cell layers has been shown to be responsible for perpetuation of reentry, giving rise to torsade de pointes. However, the absence of M cells in immature animals, especially the pig, suggests other possible underlying mechanisms. We sought to examine, in this species, the effects of predisposing factors to torsade de pointes on the dispersion of epicardial repolarization and their contribution to arrhythmogenesis. METHODS: Computerized mapping of repolarization and activation was conducted on the epicardial surface in 29 Langendorff-perfused hearts of eight-week-old pigs. Activation-recovery intervals were measured simultaneously from 128 unipolar electrograms. RESULTS: Baseline iso-interval maps were dipolar (41%) or multipolar (59%). Dispersion of repolarization was reverse frequency-dependent but was unaffected by lowering [K+]o. DL-Sotalol (0.1 mmol/l) reinforced local gradients and thus increased epicardial dispersion, whereas intramural recordings did not demonstrate any predominant effect in midmyocardial layers. Phenylephrine (1 mumol/l) notably augmented DL-sotalol effects. After [Mg++]o lowering, although dispersion was not significantly increased, DL-sotalol was associated with the spontaneous occurrence of polymorphic ventricular tachycardia in seven out of nine experiments. When maps of repolarization of escape beats were compared with activation maps of first arrhythmic beats, an arc of functional dissociation was observed in the vicinity of a steep gradient of repolarization in two out of nine tachycardias. CONCLUSION: Epicardial dispersion of repolarization is increased by slow rates, DL-sotalol and phenylephrine but is not the only requirement for initiation of polymorphic ventricular tachycardia. In combination with other factors, it helps continuation of the arrhythmia in this model.

Polymorphic ventricular tachycardias induced by D-sotalol and phenylephrine in canine preparations of atrioventricular block: initiation in the conduction system followed by spatially unstable re-entry.

OBJECTIVE: Polymorphic ventricular tachycardias (PVT) occur spontaneously in canine hearts under the combination of D-sotalol (S), bradycardia and phenylephrine (PE). We investigated the hypotheses that: (1) the activation patterns of the initial PVT beats would be consistent with an origin in the ventricular conduction system; and (2) the inhomogeneous prolongation of repolarisation intervals can provide refractory barriers for re-entrant activity. METHODS: Unipolar electrograms were recorded from 127 epicardial (EPI) sites with a sock electrode array as well as from intramural and endocardial sites during PVTs. Electrograms were analysed to generate isochronal maps and measure the spatial distribution of activation-recovery intervals (ARI). RESULTS: Under S (9.9-14.5 mg.l-1), spontaneously terminating PVTs (cycle length of 270 +/- 43 ms, n = 45) (mean +/- s.d.) occurred when a PE bolus (10-50 micrograms.kg-1) was injected. The first beat of the PVTs occurred with a coupling interval of several hundred ms to the preceding idioventricular beat (IDV) without any bridging activity and its earliest EPI breakthrough occurred in areas overlying the terminations of the right or left bundle branch. ARI values measured in IDV (295 +/- 47 ms) were significantly prolonged prior to PVT (462 +/- 92 ms). Prolongation was greater in apical than in basal epicardial areas, and at endocardial than epicardial sites (to > 500 ms). Maximum delays > 200 ms developed in the regions of marked ARI prolongation and, in later beats, circus movement re-entry occurred around refractory barriers, shifting between various regions of the ventricles. CONCLUSION: Thus, PVTs occurring spontaneously under conditions of delayed repolarisation originate from shifting sites in the ventricular conduction system and re-entrant activity shifting between various regions of the ventricle may occur in later beats of the more sustained arrhythmias.

Brain abnormalities in high-risk violent offenders and their association with psychopathic traits and criminal recidivism.

Measures of psychopathy have been proved to be valuable for risk assessment in violent criminals. However, the neuronal basis of psychopathy and its contribution to the prediction of criminal recidivism is still poorly understood. We compared structural imaging data from 40 male high-risk violent offenders and 37 non-delinquent healthy controls via voxel-based morphometry. Psychopathic traits and risk of violence recidivism were correlated with gray matter volume (GMV) of regions of interest previously shown relevant for criminal behavior. Relative to controls, criminals showed less GMV in the prefrontal cortex (PFC) and more GMV in cerebellar regions and basal ganglia structures. Within criminals, we found a negative correlation between prefrontal GMV and psychopathy. Additionally, there was a positive correlation between cerebellar GMV and psychopathy as well as risk of recidivism for violence. Moreover, GMVs of the basal ganglia and supplementary motor area (SMA) were positively correlated with anti-sociality. GMV of the amygdala was negatively correlated with dynamic risk for violence recidivism. In contrast, GMV of (para)limbic areas (orbitofrontal cortex, insula) was positively correlated with anti-sociality and risk of violence recidivism. The current investigation revealed that in violent offenders deviations in GMV of the PFC as well as areas involved in the motor component of impulse control (cerebellum, basal ganglia, SMA) are differentially related to psychopathic traits and the risk of violence recidivism. The results might be valuable for improving existing risk assessment tools.

Comparison of the D1/D2/cytochrome b559 reaction centre complex of photosystem two isolated by two different methods.

Photosystem 2 reaction centre complexes prepared either by solubilisation with Triton X-100 and subsequent exchange into dodecyl maltoside or by a procedure involving a combination of dodecyl maltoside and LiClO4, were characterised in terms of chlorophyll a, pheophytin a, beta-carotene and cytochrome b559 content. Time-resolved chlorophyll fluorescence decay kinetics were measured using both types of complexes. Our data show that the isolated photosystem two reaction centre complex contain, for two pheophytin a molecules, close to six chlorophyll a, two beta-carotene and one cytochrome b559. No major differences were observed in the composition or the kinetic characteristics measured in the samples prepared by the different procedures. Time-resolved fluorescence measurements indicate that more than 94% of the chlorophyll a in both preparations is coupled to the reaction centre complex.

Role of mechanical and hormonal factors in cardiac remodeling and the biologic limits of myocardial adaptation.

Patients with chronic congestive heart failure manifest > or = 1 of the following abnormalities: diastolic dysfunction, systolic dysfunction, and arrhythmias. Diastolic dysfunction, one of the first symptoms to occur during hypertensive cardiopathy, depends on both active relaxation of the cardiac muscle and passive ventricular compliance. The ability of the ventricles to relax depends on normal calcium metabolism and adenosine triphosphate concentration. Ability to extrude intracellular calcium is depressed in the hypertrophied, overloaded heart as compared with the normal myocardium. Myocardial fibrosis is the major cause of increased diastolic ventricular stiffness. Left ventricular (LV) hypertrophy and myocardial fibrosis also greatly increase the likelihood of ventricular arrhythmias, in particular by prolonging the QRS interval and facilitating the occurrence of reentry arrhythmias. Findings in animal studies have indicated that such fibrosis, which involves excessive collagen deposition, is independent of LV hypertrophy and that LV hypertrophy does not necessarily result in myocardial fibrosis. Instead, the development of myocardial fibrosis is sensitive to circulating levels of both angiotensin II and aldosterone, and the fibrotic response to each of these substances is independent. The aldosterone antagonist spironolactone prevents myocardial fibrosis in several animal models, thus confirming the importance of aldosterone in the genesis of excessive collagen deposition.

Randomized comparison of two targets in typical atrial flutter ablation.

Typical atrial flutter ablation has become anatomically guided to 2 separate sites within the isthmus at the inferior right atrium: (1) between the inferior vena cava and the tricuspid annulus (anterior side of the isthmus [A]), (2) between the eustachian crest, the coronary sinus ostium and tricuspid annulus (posterior side of the isthmus [P]). We prospectively compared ablation results at these sites in 72 consecutive patients. Patients were randomized in group P or A according to the initial target site. If ablation failed at 1 site after 15 radiofrequency (RF) pulses, the other side of the isthmus was targeted. Before 15 RF pulses, complete bidirectional isthmus block was achieved in 30 of 36 group A patients and in 25 of 36 group P patients, with similar mean RF pulses number, procedure time, and fluoroscopy time. After shifting to the other target, success was finally obtained at P in 2 of 6 group A patients, and at A in 8 of 11 group P patients before a maximum of 30 RF pulses. Among successful patients, number of RF pulses, procedure time, and fluoroscopy time were significantly lower in group A (7.2 +/- 5.4 vs 11.0 +/- 8.1 pulses, p = 0.03; 131 +/- 44 vs 163 +/- 66 minutes, p = 0.03; 31 +/- 19 vs 46 +/- 24 minutes, p = 0.01, respectively). Impairment of atrioventricular (AV) nodal conduction occurred in 5 patients only during ablation at P. AV block was transient in 4 patients and permanent in 1. Although atrial flutter ablation is equally effective at P and A, success seems easier to obtain when A is first targeted. Ablation at P is associated with a significant risk of AV block.