The star approach, a surgical approach for skin sparing mastectomy and central lumpectomies

When preservation of the nipple-areolar complex (NAC) is not possible in oncologic breast surgery, the traditional approaches are either a horizontal incision centered on the NAC resulting in visible scars and breast distortion, or a round block with risk of healing difficulties. To address these concerns, the authors propose a star approach technique for skin sparing mastectomies and lumpectomies of central breast tumors. During the oncologic surgery, the NAC is removed with four cutaneous extensions, which can be closed as a cross-shaped scar. The scarring is similar in size to the original NAC diameter and can easily be covered by the NAC reconstruction. This technique offers good exposure during surgery, a good aesthetic result with limited scarring, no breast deformity, correction of breast sagging, and high-quality healing.

A methodology to empower citizens towards a low-carbon economy. The potential of schools and sustainability indicators

Environmental empowering to control resource consumption and environmental impacts is critical to engage citizens to adopt more sustainable habits. This study demonstrates the potential benefits of innovative approaches based on sustainability indicators towards a low-carbon economy. A methodology to measure and promote sustainability in schools has been proposed and evaluated, aiming at showing the environmental performance and informing of potential environmental savings. The methodology, titled ClimACT, has two main purposes: measuring the environmental performance of schools through a school sustainability index based on measurable indicators in the areas of transport, procurement, green spaces, indoor air quality, energy, water and waste; and encouraging students, teachers and families towards an energy-efficient and low-carbon pathway through a structural procedure based on roles, activities and progress evaluation. The approach, applied to 39 pilot schools from Portugal, Spain, France and Gibraltar, achieved promising and encouraging results. All schools deployed the methodology successfully, achieving measurable environmental benefits in 95% of cases, with an average improvement of 10% in the global performance of schools after one year. Moreover, the 5112 surveys applied to school communities, before and after the methodology implementation, highlighted how the sustainable indicators had a significant influence on the daily lives of families, leading to improvements of their behaviour, with an average increase of 20% in indicators regarding good practices in transport, energy, water, waste and citizenship. The environmental empowering through measurable indicators is a step forward a low-carbon economy. This methodology is open and adaptable to all sectors and requirements.

Contribution of plasma cells and B cells to hidradenitis suppurativa pathogenesis

Hidradenitis suppurativa (HS) is a debilitating chronic inflammatory skin disease characterized by chronic abscess formation and development of multiple draining sinus tracts in the groin, axillae, and perineum. Using proteomic and transcriptomic approaches, we characterized the inflammatory responses in HS in depth, revealing immune responses centered on IFN-γ, IL-36, and TNF, with lesser contribution from IL-17A. We further identified B cells and plasma cells, with associated increases in immunoglobulin production and complement activation, as pivotal players in HS pathogenesis, with Bruton’s tyrosine kinase (BTK) and spleen tyrosine kinase (SYK) pathway activation as a central signal transduction network in HS. These data provide preclinical evidence to accelerate the path toward clinical trials targeting BTK and SYK signaling in moderate-to-severe HS.

B-cells and plasma cells are critical pathogenic cell populations in chronic Hidradenitis Suppurativa and are potential therapeutic targets.

Magnetic-Order Crossover in Coupled Spin Ladders

We report a novel crossover behavior in the long-range-ordered phase of a prototypical spin-1/2 Heisenberg antiferromagnetic ladder compound (C_{7}H_{10}N)_{2}CuBr_{4}. The staggered order was previously evidenced from a continuous and symmetric splitting of ^{14}N NMR spectral lines on lowering the temperature below T_{c}≃330  mK, with a saturation towards ≃150  mK. Unexpectedly, the split lines begin to further separate away below T^{*}∼100  mK, while the linewidth and the line shape remain completely invariable. This crossover behavior is further corroborated by the NMR relaxation rate T_{1}^{-1} measurements. A very strong suppression reflecting the ordering, T_{1}^{-1}∼T^{5.5}, observed above T^{*}, is replaced by T_{1}^{-1}∼T below T^{*}. These original NMR features are indicative of the unconventional nature of the crossover, which may arise from a unique arrangement of the ladders into a spatially anisotropic and frustrated coupling network.

Quasiparticle Scattering off Defects and Possible Bound States in Charge-Ordered YBa_{2}Cu_{3}O_{y}

We report the NMR observation of a skewed distribution of ^{17}O Knight shifts when a magnetic field quenches superconductivity and induces long-range charge-density-wave (CDW) order in YBa_{2}Cu_{3}O_{y}. This distribution is explained by an inhomogeneous pattern of the local density of states N(E_{F}) arising from quasiparticle scattering off, yet unidentified, defects in the CDW state. We argue that the effect is most likely related to the formation of quasiparticle bound states, as is known to occur, under specific circumstances, in some metals and superconductors (but not in the CDW state, in general, except for very few cases in 1D materials). These observations should provide insight into the microscopic nature of the CDW, especially regarding the reconstructed band structure and the sensitivity to disorder.

Dichotomy between Attractive and Repulsive Tomonaga-Luttinger Liquids in Spin Ladders

We present a direct NMR method to determine whether the interactions in a Tomonaga-Luttinger liquid (TLL) state of a spin-1/2 Heisenberg antiferromagnetic ladder are attractive or repulsive. For the strong-leg spin ladder compound (C_{7}H_{10}N)_{2}CuBr_{4} we find that the isothermal magnetic field dependence of the NMR relaxation rate T_{1}^{-1}(H) displays a concave curve between the two critical fields bounding the TLL regime. This is in sharp contrast to the convex curve previously reported for a strong-rung ladder, (C_{5}H_{12}N)_{2}CuBr_{4}. We show that the concavity and the convexity of T_{1}^{-1}(H), which is a fingerprint of spin fluctuations, directly reflect the attractive and repulsive fermionic interactions in the TLL, respectively. The interaction sign is alternatively determined from an indirect method combining bulk magnetization and specific heat data.

Meta-Analysis from Gene Expression Profiles of Lupus Affected Tissues Reveals Novel Immune Cell Contributions

Immunologic mechanisms causing tissue damage in autoimmune diseases such as SLE are not fully understood. To gain additional insight, gene expression profiles obtained from lupus affected skin, synovium and kidney were obtained and compared to meta-analyzed data obtained from active lupus B, T and myeloid cells. More than 300 arrays from lupus patients and appropriate controls were analyzed to determine differentially expressed (DE) genes (8279 discoid lupus skin, 5465 synovium, 6381 glomerulus, 5587 tubulointerstitum). Notably, the majority of lupus affected tissue DE genes were detected in more than one tissue and 439 were differentially expressed in all tissues. A variety of approaches assessed the molecular pathways and cellular phenotypes accounting for these common lupus affected tissue DE genes. Curated STRING-based interaction analysis identified a number of pathways including co-stimulation of T cells, activation of B and myeloid cells, antigen presentation, TLR signaling and p38 activation; from a total of 193 IPA-documented pathways, 59 were common to all tissues including p38 signaling, TLR signaling, maturation of dendritic cells, B cell activation and ICOS-ICOSL in T cells. Novel bioinformatics approaches documented that more than 50% of the DE genes in the tissues were associated with immune cell function and 11–18% were unique to the immune system. Further analysis using LINCS and additional novel software highlighted specific molecular pathways of immune cell activation including the JAK/STAT and the IL12 pathways. These results demonstrate the value of comprehensive application of orthogonal curated bioinformatics tools in identifying the role of immune cells in lupus pathogenesis and tissue damage.

Reentrant superconductivity driven by quantum tricritical fluctuations in URhGe: evidence from ^{59}Co NMR in URh_{0.9}Co_{0.1}Ge

Our measurements of the ^{59}Co NMR spin-spin relaxation in URh_{0.9}Co_{0.1}Ge reveal a divergence of electronic spin fluctuations in the vicinity of the field-induced quantum critical point at H_{R}≈13  T, around which reentrant superconductivity (RSC) occurs in the ferromagnetic heavy fermion compound URhGe. We map out the strength of spin fluctuations in the (H_{b},H_{c}) plane of magnetic field components and show that critical fluctuations develop in the same limited region near the field H_{R} as that where RSC is observed. This strongly suggests these quantum fluctuations as the pairing glue responsible for the RSC. The fluctuations observed are characteristic of a tricritical point, followed by a phase bifurcation toward quantum critical end points.

Modulation of macrophage responses by aberrant lipoproteins in chronic inflammatory diseases. (HUM3P.241)

Lupus (SLE) patients are fifty times more likely to experience a cardiovascular event compared to age- and sex-matched controls. High levels of oxidized HDL (oxHDL) in SLE patients may contribute to this association. Under normal conditions, unoxidized HDL induces an anti-inflammatory response within macrophages (MØ). We addressed whether lupus oxHDL modifies this response and putative mechanisms associated with enhanced inflammation. Methods: Affymetrix gene expression analysis was performed on control MØs exposed to control or lupus HDL before an LPS challenge. Confirmation at the mRNA and protein level was performed. Signaling pathways involved in gene induction abnormalities were explored using molecular approaches. Results: MØs exposed to SLE HDL up-regulate IL-6, IL-12B and TNF-α at the mRNA and protein levels, compared to MØs exposed to healthy HDL. SLE HDL showed impaired induction of ATF3 mRNA and nuclear translocation. ATF3 activity was restored when the oxHDL binding protein LOX-1 receptor was inhibited with blocking antibodies. SLE HDL also showed a decrease activation of kinases upstream of ATF3 activation. Conclusion: Lupus HDL induces inflammatory responses in macrophages which may promote phenotypic proatherogenic changes and increase cardiovascular risk in this disease. Modifying the HDL proteome in SLE may decrease this risk.

Longitudinal and transverse Zeeman ladders in the Ising-like chain antiferromagnet BaCo(2)V(2)O(8)

We explore the spin dynamics emerging from the Néel phase of the chain compound antiferromagnet BaCo(2)V(2)O(8). Our inelastic neutron scattering study reveals unconventional discrete spin excitations, so-called Zeeman ladders, understood in terms of spinon confinement, due to the interchain attractive linear potential. These excitations consist of two interlaced series of modes, respectively, with transverse and longitudinal polarization. The latter, which correspond to a longitudinal fluctuation of the ordered moment, have no classical counterpart and are related to the zero-point fluctuations that weaken the ordered moment in weakly coupled quantum chains. Our analysis reveals that BaCo(2)V(2)O(8), with moderate Ising anisotropy and sizable interchain interactions, remarkably fulfills the conditions necessary for the observation of discrete long-lived longitudinal excitations.

Attractive Tomonaga-Luttinger liquid in a quantum spin ladder

We present NMR measurements of a strong-leg spin-1/2 Heisenberg antiferromagnetic ladder compound (C7H10N)2CuBr4 under magnetic fields up to 15 T in the temperature range from 1.2 K down to 50 mK. From the splitting of NMR lines, we determine the phase boundary and the order parameter of the low-temperature (three-dimensional) long-range-ordered phase. In the Tomonaga-Luttinger regime above the ordered phase, NMR relaxation reflects characteristic power-law decay of spin correlation functions as 1/T1∝T(1/2K-1), which allows us to determine the interaction parameter K as a function of field. We find that field-dependent K varies within the 1<K<2 range, which signifies attractive interaction between the spinless fermions in the Tomonaga-Luttinger liquid.

Microscopic properties of the pinwheel kagome compound Rb(2)Cu(3)SnF(12)

Using (63,65)Cu nuclear magnetic resonance in magnetic fields up to 30 T, we study the microscopic properties of the 12-site valence-bond-solid ground state in the "pinwheel" kagome compound Rb(2)Cu(3)SnF(12). We find that the ground state is characterized by a strong transverse staggered spin polarization whose temperature and field dependence points to a mixing of the singlet and triplet states. This is further corroborated by the field dependence of the gap Δ(H), which has a level anticrossing with a large minimum gap value of ≈ Δ(0)/2, with no evidence of a phase transition down to 1.5 K. By the exact diagonalization of small clusters, we show that the observed anticrossing is mainly due to staggered tilts of the g tensors defined by the crystal structure and reveal symmetry properties of the low-energy excitation spectrum compatible with the absence of level crossing.

Field-induced quantum soliton lattice in a frustrated two-leg spin-1/2 ladder

Based on high-field (31)P nuclear magnetic resonance experiments and accompanying numerical calculations, it is argued that in the frustrated S=1/2 ladder compound BiCu(2)PO(6) a field-induced soliton lattice develops above a critical field of μ(0)H(c1)=20.96(7) T. Solitons result from the fractionalization of the S=1, bosonlike triplet excitations, which in other quantum antiferromagnets are commonly known to experience Bose-Einstein condensation or to crystallize in a superstructure. Unlike in spin-Peierls systems, these field-induced quantum domain walls do not arise from a state with broken translational symmetry and are triggered exclusively by magnetic frustration. Our model predicts yet another second-order phase transition at H(c2)>H(c1), driven by soliton-soliton interactions, most likely corresponding to the one observed in recent magnetocaloric and other bulk measurements.

Incomplete devil's staircase in the magnetization curve of SrCu2(BO3)2

We report on NMR and torque measurements on the frustrated quasi-two-dimensional spin-dimer system SrCu(2)(BO(3))(2) in magnetic fields up to 34 T that reveal a sequence of magnetization plateaus at 1/8, 2/15, 1/6, and 1/4 of the saturation and two incommensurate phases below and above the 1/6 plateau. The magnetic structures determined by NMR involve a stripe order of triplets in all plateaus, suggesting that the incommensurate phases originate from proliferation of domain walls. We propose that the magnetization process of SrCu(2)(BO(3))(2) is best described as an incomplete devil's staircase.

Quantum-critical spin dynamics in quasi-one-dimensional antiferromagnets

By means of nuclear spin-lattice relaxation rate T(1)(-1), we follow the spin dynamics as a function of the applied magnetic field in two gapped quasi-one-dimensional quantum antiferromagnets: the anisotropic spin-chain system NiCl(2)-4SC(NH(2))(2) and the spin-ladder system (C(5)H(12)N)(2)CuBr(4). In both systems, spin excitations are confirmed to evolve from magnons in the gapped state to spinons in the gapless Tomonaga-Luttinger-liquid state. In between, T(1)(-1) exhibits a pronounced, continuous variation, which is shown to scale in accordance with quantum criticality. We extract the critical exponent for T(1)(-1), compare it to the theory, and show that this behavior is identical in both studied systems, thus demonstrating the universality of quantum-critical behavior.

Field evolution of coexisting superconducting and magnetic orders in CeCoIn5

We present nuclear magnetic resonance (NMR) measurements on the three distinct In sites of CeCoIn5 with a magnetic field applied in the [100] direction. We identify the microscopic nature of the long range magnetic order (LRO) stabilized at low temperatures in fields above 10.2 T while still in the superconducting (SC) state. We infer that the ordered moment is oriented along the c axis and map its field evolution. The study of the field dependence of the NMR shift for the different In sites indicates that the LRO likely coexists with a modulated SC phase, possibly that predicted by Fulde, Ferrell, Larkin, and Ovchinnikov. Furthermore, we discern a field region dominated by strong spin fluctuations where static LRO is absent and propose a revised phase diagram.

Advanced glycation end products regulate extracellular matrix protein and protease expression by human glomerular mesangial cells

Advanced glycation end products (AGEs) may play a role in the pathogenesis of diabetic nephropathy, by modulating extracellular matrix turnover. AGEs are known to activate specific membrane receptors, including the receptor for AGE (RAGE). In the present study, we analyzed the various receptors for AGEs expressed by human mesangial cells and we studied the effects of glycated albumin and of carboxymethyl lysine on matrix protein and remodelling enzyme synthesis. Membrane RAGE expression was confirmed by FACS analysis. Microarray methods, RT-PCR, and Northern blot analysis were used to detect and confirm specific gene induction. Zymographic analysis and ELISA were used to measure the induction of tPA and PAI-1. We show herein that cultured human mesangial cells express AGE receptor type 1, type 2 and type 3 and RAGE. AGEs (200 microg/ml) induced at least a 2-fold increase in mRNA for 10 genes involved in ECM remodelling, including tPA, PAI-1 and TIMP-3. The increase in tPA synthesis was confirmed by fibrin zymography. The stimulation of PAI-1 synthesis was confirmed by ELISA. AGEs increased PAI-1 mRNA through a signalling pathway involving reactive oxygen species, the MAP kinases ERK-1/ERK-2 and the nuclear transcription factor NF-kappaB, but not AP-1. Carboxymethyl lysine (CML, 5 microM), which is a RAGE ligand, also stimulated PAI-1 synthesis by mesangial cells. In addition, a blocking anti-RAGE antibody partially inhibited the AGE-stimulated gene expression and decreased the PAI-1 accumulation induced by AGEs and by CML. Inhibition of AGE receptors or neutralization of the protease inhibitors TIMP-3 and PAI-1 could represent an important new therapeutic strategy for diabetic nephropathy.

Spin configuration in the 1/3 magnetization plateau of azurite determined by NMR

High magnetic field (63,65)Cu NMR spectra were used to determine the local spin polarization in the 1/3 magnetization plateau of azurite, Cu3(CO3)(2)(OH)(2), which is a model system for the distorted diamond antiferromagnetic spin-1/2 chain. The spin part of the hyperfine field of the Cu2 (dimer) sites is found to be field independent, negative and strongly anisotropic, corresponding to approximately 10% of fully polarized spin in a d orbital. This is close to the expected configuration of the quantum plateau, where a singlet state is stabilized on the dimer. However, the observed nonzero spin polarization points to some triplet admixture, induced by strong asymmetry of the diamond bonds J1 and J3.

Controlling Luttinger liquid physics in spin ladders under a magnetic field

We present a 14N nuclear magnetic resonance study of a single crystal of CuBr4(C5H12N)2 (BPCB) consisting of weakly coupled spin-1/2 Heisenberg antiferromagnetic ladders. Treating ladders in the gapless phase as Luttinger liquids, we are able to fully account for (i) the magnetic field dependence of the nuclear spin-lattice relaxation rate T1(-1) at 250 mK and for (ii) the phase transition to a 3D ordered phase occurring below 110 mK due to weak interladder exchange coupling. BPCB is thus an excellent model system where the possibility to control Luttinger liquid parameters in a continuous manner is demonstrated and the Luttinger liquid model tested in detail over the whole fermion band.

Field dependence of the ground state in the exotic superconductor CeCoIn5: a nuclear magnetic resonance investigation

We report 115In nuclear magnetic resonance (NMR) measurements in CeCoIn5 at low temperature (T approximately 70 mK) as a function of the magnetic field (H0) from 2 to 13.5 T applied perpendicular to the c axis. A NMR line shift reveals that below 10 T the spin susceptibility increases as sqrt[H0]. We associate this with an increase of the density of states due to the Zeeman and Doppler-shifted quasiparticles extended outside the vortex cores in a d-wave superconductor. Above 10 T a new superconducting state is stabilized, possibly the modulated phase predicted by Fulde, Ferrell, Larkin, and Ovchinnikov. This phase is clearly identified by a strong and linear increase of the NMR shift with the field, before a jump at the first order transition to the normal state.

NMR evidence for the persistence of a spin superlattice beyond the 1/8 magnetization plateau in SrCu2(BO3)_{2}

We present 11B NMR studies of the 2D frustrated dimer spin system SrCu2(BO3)_{2} in the field range 27-31 T covering the upper phase boundary of the 1/8 magnetization plateau, identified at 28.4 T. Our data provide a clear evidence that above 28.4 T the spin superlattice of the 1/8 plateau is modified but does not melt even though the magnetization increases. Although this is precisely what is expected for a supersolid phase, the microscopic nature of this new phase is much more complex. We discuss the field-temperature phase diagram on the basis of our NMR data.

Electronic texture of the thermoelectric oxide Na0.75CoO2

From 59Co and 23Na NMR, we demonstrate the impact of the Na+ vacancy ordering on the cobalt electronic states in Na0.75CoO2: at long time scales, there is neither a disproportionation into 75% Co3+ and 25% Co4+ states, nor a mixed-valence metal with a uniform Co3.25+ state. Instead, the system adopts an intermediate configuration in which 30% of the lattice sites form an ordered pattern of localized Co3+ states. Above 180 K, an anomalous mobility of specific Na+ sites is found to coexist with this electronic texture, suggesting that the formation of the latter may contribute to stabilizing the Na+ ordering. Control of the ion doping in these materials thus appears to be crucial for fine-tuning of their thermoelectric properties.

Huge transverse magnetic polarization in the field-induced phase of the antiferromagnetic molecular wheel CsFe(8)

The 1H NMR spectrum and nuclear relaxation rate T(1)(-1) in the antiferromagnetic wheel CsFe8 were measured to characterize the previously observed magnetic field-induced low-temperature phase around the level crossing at 8 T. The data show that the phase is characterized by a huge staggered transverse polarization of the electronic Fe spins, and the opening of a gap, providing microscopic evidence for the interpretation of the phase as a field-induced magnetoelastic instability.

Electronic correlations in CoO2, the parent compound of triangular cobaltates

A 59Co NMR study of CoO2, the x=0 end member of AxCoO2 (A=Na,Li,...) cobaltates, reveals a metallic ground state, though with clear signs of strong electron correlations: low-energy spin fluctuations develop at wave vectors q not equal to 0 and a crossover to a Fermi-liquid regime occurs below a characteristic temperature T* approximately 7 K. Despite some uncertainty over the exact cobalt oxidation state in this material, the results show that electronic correlations are revealed as x is reduced below 0.3. The data are consistent with NaxCoO2 being close to the Mott transition in the x-->0 limit.

Field-induced staggered magnetization and magnetic ordering in Cu2(C5H12N2)2Cl4

We present a 2D NMR investigation of the gapped spin-1/2 compound Cu2(C5H10N2D2)2Cl4. Our measurements reveal the presence of a magnetic field-induced transverse staggered magnetization (TSM) which persists well below and above the field-induced 3D long-range magnetically ordered (FIMO) phase. The symmetry of this TSM is different from that of the TSM induced by the order parameter of the FIMO phase. Its origin, field dependence, and symmetry can be explained by an intradimer Dzyaloshinskii-Moriya interaction, as shown by DMRG calculations on a spin-1/2 ladder. This leads us to predict that the transition into the FIMO phase is not in the BEC universality class.

Observation of spin susceptibility enhancement in the possible Fulde-Ferrell-Larkin-Ovchinnikov state of CeCoIn(5)

We report (115)In nuclear magnetic resonance measurements of the heavy-fermion superconductor CeCoIn(5) in the vicinity of the superconducting critical field H(c2) for a magnetic field applied perpendicular to the ĉ axis. A possible inhomogeneous superconducting state, the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, is stabilized in this part of the phase diagram. In an 11 T applied magnetic field, we observe clear signatures of the two phase transitions: the higher temperature one to the homogeneous superconducting state and the lower temperature phase transition to a FFLO state. We find that the spin susceptibility in the putative FFLO state is significantly enhanced as compared to the value in a homogeneous superconducting state. The implications of this finding for the nature of the low temperature phase are discussed.

Impurity-induced local magnetism and density of states in the superconducting state of YBa2Cu3O7

17O NMR is used to probe the local influence of nonmagnetic Zn and magnetic Ni impurities in the superconducting state of optimally doped high TC YBa2Cu3O7. Zn and Ni induce a staggered paramagnetic polarization, similar to that evidenced above TC, with a typical extension xi=3 cell units for Zn and xi>or=3 for Ni. In addition, Zn is observed to induce a local density of states near the Fermi energy in its neighborhood, which also decays over about 3 cell units. Its magnitude decreases sharply with increasing temperature. This allows direct comparison with the STM observations done in BiSCCO.

Nonmagnetic insulator state in Na1CoO2 and phase separation of na vacancies

Crystallographic, magnetic, and NMR properties of a Na1CoO2 single crystal with x approximately = 1 are presented. We identify the stoichiometric Na1CoO2 phase, which is shown to be a nonmagnetic insulator, as expected for homogeneous planes of Co3+ ions with S = 0. In addition, we present evidence that, because of slight average Na deficiency, chemical and electronic phase separation leads to a segregation of Na vacancies into the well-defined, magnetic, Na0.8CoO2 phase. The importance of phase separation is discussed in the context of magnetic order for x approximately = 0.8 and the occurrence of a metal-insulator transition for x --> 1.

Angiotensin-Converting Enzyme Inhibition but not Angiotensin II Receptor Blockade Regulates Matrix Metalloproteinase Activity in Patients with Glomerulonephritis

ABSTRACT. Equivalent long-term effects on the kidney are attributed to angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II type 1 receptor blockers (ARB). Nevertheless, it is unknown to which degree effects of these compounds on individual inflammatory mediators, including matrix metalloproteinases (MMP), are comparable. On the basis of structural and functional differences, it was hypothesized that ACEI and ARB differentially regulate MMP activity. In a randomized, prospective crossover trial, the effect of an ACEI (fosinopril; 20 mg/d) and of an ARB (irbesartan; 150 mg/d) on MMP activity was evaluated. Ten hypertensive patients with glomerulonephritis and normal or mildly reduced creatinine clearance were studied. MMP activity and tissue inhibitors of metalloproteinase (TIMP) levels were analyzed in serum and urine: without therapy, with ACEI, with ARB, and with both agents combined. Treatment periods continued for 6 wk separated by periods of 4 wk each without therapy. Untreated patients with glomerulonephritis displayed distinctively higher serum levels of MMP-2 but much lower MMP-1/-8/-9 concentrations compared with healthy control subjects. Immunohistology of MMP-2 and MMP-9 in kidney biopsy specimen was accordingly. However, these patients excreted higher amounts of MMP-2 and MMP-9 in urine than healthy control subjects, possibly reflecting ongoing glomerular inflammation. In patients with glomerulonephritis, ACEI significantly reduced overall MMP serum activity to 25%, whereas ARB did not show any effect. Activities of MMP-1/-2/-8/-9 were also significantly inhibited by fosinopril but not by irbesartan. Levels of TIMP-1/-2 remained unaffected. In conclusion, ACEI and ARB differentially regulate MMP activity, which may ultimately have consequences in certain types of MMP-dependent glomerulonephritis. E-mail: hpmarti@bluewin.ch

NMR investigation of how free composite fermions are at nu=1 / 2

NMR measurements of the electron spin polarization (P) have been performed on a 2D electron system at and around half-filled lowest Landau level. Comparing the magnetic field and the temperature dependence of P to models of free and interacting composite fermions (CF), the imbalance of spin-up and spin-down CF Fermi seas is mapped as a function of Zeeman energy. Independent measurements of the CF effective mass, g factor, and Fermi energy are obtained from the thermal activation of P in tilted fields. The filling factor dependence of the P for 2 / 5<nu<2 / 3 reveals a broken particle-hole symmetry for the partially polarized CF Fermi sea.

Magnetic superstructure in the two-dimensional quantum antiferromagnet SrCu2(BO3)2

We report the observation of magnetic superstructure in a magnetization plateau state of SrCu2(BO3)2, a frustrated quasi-two-dimensional quantum spin system. The Cu and B nuclear magnetic resonance (NMR) spectra at 35 millikelvin indicate an apparently discontinuous phase transition from uniform magnetization to a modulated superstructure near 27 tesla, above which a magnetization plateau at 1/8 of the full saturation has been observed. Comparison of the Cu NMR spectrum and the theoretical analysis of a Heisenberg spin model demonstrates the crystallization of itinerant triplets in the plateau phase within a large rhomboid unit cell (16 spins per layer) showing oscillations of the spin polarization. Thus, we are now in possession of an interesting model system to study a localization transition of strongly interacting quantum particles.

New phase transition between partially and fully polarized quantum Hall states with charge and spin gaps at nu = 2/3

The average electron spin polarization Rho of a two-dimensional electron gas confined in GaAs/GaAlAs multiple quantum wells was measured by NMR near the fractional quantum Hall state with filling factor nu = 2/3. Above this filling factor (2/3< or = nu < 0.85), a strong depolarization is observed corresponding to two spin flips per additional flux quantum. The most remarkable behavior of the polarization is observed at nu = 2/3, where a quantum phase transition from a partially polarized (Rho approximately 3/4) to a fully polarized (Rho = 1) state can be driven by increasing the ratio between the Zeeman and the Coulomb energy above a critical value eta(c) = Delta(Z)/Delta(C) = 0.0185.

Voltage-gated sodium channel (SkM1) content in dystrophin-deficient muscle

The membrane cytoskeleton is increasingly considered as both an anchor and a functional modulator for ion channels. The cytoskeletal disruptions that occur in the absence of dystrophin led us to investigate the voltage-gated sodium channel (SkM1) content in the extensor digitorum longus (EDL) muscle of the dystrophin-deficient mdx mouse. Levels of SkM1 mRNA were determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). A C-terminal portion of the mouse-specific SkM1 alpha-subunit cDNA (mScn4a) was identified first. SkM1 mRNA levels were as abundant in mdx as in normal muscle, thus suggesting that the transcriptional rate of SkM1 remains unchanged in mdx muscle. However, SkMI density in the extrajunctional sarcolemma was shown to be significantly reduced in mdx muscle, using confocal immunofluorescence image analysis. This decrease was found to be associated with a reduction in the number of SkM1-rich fast-twitch IIb fibres in mdx muscle. In addition, lowered SkM1 sarcolemmal labelling was found in all mdx fibres regardless of their metabolic type. These results suggest the existence of a perturbation of SkM1 anchorage to the plasma membrane. Such an alteration is likely to be related to the 50% decrease in mdx muscle of the dystrophin-associated syntrophins, which are presumed to be involved in SkM1 anchorage. However, the moderate reduction in SkM1 density (-12.7%) observed in mdx muscle argues in favour of a non-exclusive role of syntrophins in SkM1 anchorage and suggests that other membrane-associated proteins are probably also involved.

NMR evidence for a "Generalized spin-peierls Transition" in the high-magnetic-field phase of the spin ladder Cu2(C5H12N2)2Cl4

The magnetic-field-induced 3D ordered phase of the two-leg spin ladder Cu2(C5H12N2)2Cl4 has been probed through measurements of 1H NMR spectra and 1/T1 in the temperature range 70 mK-1.2 K. The second order transition line T(c)(H) has been determined between H(c1) = 7.52 T and H(c2) = 13.5 T and varies as (H-H(c1))(2/3) close to H(c1). From the observation of anomalous shifts and a crossover in 1/T1 above T(c), the mechanism of the 3D transition is argued to be magnetoelastic as in spin-Peierls chains, here involving a displacement of the protons along the longitudinal exchange ( J( parallel)) path.

63Cu NMR evidence for enhanced antiferromagnetic correlations around Zn impurities in YBa2Cu3O6.7

Doping the high- T(c) superconductor YBa2Cu3O6.7 with 1.5% of nonmagnetic Zn impurities in CuO2 planes is shown to produce a considerable broadening of 63Cu NMR spectra, as well as an increase of low-energy magnetic fluctuations detected in 63Cu spin-lattice relaxation measurements. A model-independent analysis demonstrates that these effects are due to the development of staggered magnetic moments on many Cu sites around each Zn and that the Zn-induced moment in the bulk susceptibility might be explained by this staggered magnetization. Several implications of these enhanced antiferromagnetic correlations are discussed.

NMR determination of 2D electron spin polarization at nu = 1/2

Using a "standard" NMR spin-echo technique we determined the spin polarization P of two-dimensional electrons, confined to GaAs quantum wells, from the hyperfine shift of Ga nuclei located in the wells. Concentrating on the temperature ( 0.05 less, similarT less, similar10 K) and magnetic field ( 7 less, similarB less, similar17 T) dependencies of P at Landau level filling factor nu = 1/2, we find that the results are described well by a simple model of noninteracting composite fermions, although some inconsistencies remain when the two-dimensional electron system is tilted in the magnetic field.

Caldesmon inhibits nonmuscle cell contractility and interferes with the formation of focal adhesions

Caldesmon is known to inhibit the ATPase activity of actomyosin in a Ca(2+)-calmodulin-regulated manner. Although a nonmuscle isoform of caldesmon is widely expressed, its functional role has not yet been elucidated. We studied the effects of nonmuscle caldesmon on cellular contractility, actin cytoskeletal organization, and the formation of focal adhesions in fibroblasts. Transient transfection of nonmuscle caldesmon prevents myosin II-dependent cell contractility and induces a decrease in the number and size of tyrosine-phosphorylated focal adhesions. Expression of caldesmon interferes with Rho A-V14-mediated formation of focal adhesions and stress fibers as well as with formation of focal adhesions induced by microtubule disruption. This inhibitory effect depends on the actin- and myosin-binding regions of caldesmon, because a truncated variant lacking both of these regions is inactive. The effects of caldesmon are blocked by the ionophore A23187, thapsigargin, and membrane depolarization, presumably because of the ability of Ca(2+)-calmodulin or Ca(2+)-S100 proteins to antagonize the inhibitory function of caldesmon on actomyosin contraction. These results indicate a role for nonmuscle caldesmon in the physiological regulation of actomyosin contractility and adhesion-dependent signaling and further demonstrate the involvement of contractility in focal adhesion formation.