Liver Abscess Due to Migrated Foreign Body

Liver abscess secondary to a migrated foreign body (fish bone) is a rare entity where early diagnosis helps in management and thereby improves the prognosis. We present a unique case of a 47-year-old hypertensive man who presented with high-grade fever, chills, rigors, and abdominal pain. On evaluation, he was found to have a liver abscess secondary to a foreign body (fish bone), although no history of foreign body ingestion was recalled by the patient. Drainage of liver abscess and removal of the foreign body comprise the treatment of choice. We report the successful management of a patient with liver abscess from a migrated fish bone. This case underscores the importance of considering foreign body ingestion as a potential cause of liver abscess, even when patients cannot recall such an event. Timely diagnosis and intervention, along with advances in imaging techniques, contribute to successful outcomes in these rare but challenging cases.

Post-COVID-19 cholangiopathy: Current understanding and management options

Post-coronavirus disease 2019 (COVID-19) cholangiopathy (PCC) is a rare but life-threatening complication of COVID-19 infection. PCC typically presents when patients recovering from the contagion and manifests as cholestasis in patients with no history of pre-existing liver disease. The pathogenesis of PCC is little understood. Hepatic injury in PCC could be mediated by the predilection of severe acute respiratory syndrome coronavirus 2 for cholangiocytes. Though PCC shows some resemblance to secondary sclerosing cholangitis in critically ill patients, it is considered as a separate and unique entity in the literature. Various treatment options like ursodeoxycholic acid, steroids, plasmapheresis, and endoscopic retrograde cholangiopancreatography guided interventions have been tried but with limited success. We have noticed significant improvement in liver function with antiplatelet therapy in a couple of patients. PCC can progress to end-stage liver disease necessitating liver transplantation. In this article, we discuss the current knowledge of PCC focusing on its pathophysiology, clinical manifestations, and management strategies.

Prethermal Fragmentation in a Periodically Driven Fermionic Chain

We study a fermionic chain with nearest-neighbor hopping and density-density interactions, where the nearest-neighbor interaction term is driven periodically. We show that such a driven chain exhibits prethermal strong Hilbert space fragmentation (HSF) in the high drive amplitude regime at specific drive frequencies ω_{m}^{*}. This constitutes the first realization of HSF for out-of-equilibrium systems. We obtain analytic expressions of ω_{m}^{*} using a Floquet perturbation theory and provide exact numerical computation of entanglement entropy, equal-time correlation functions, and the density autocorrelation of fermions for finite chains. All of these quantities indicate clear signatures of strong HSF. We study the fate of the HSF as one tunes away from ω_{m}^{*} and discuss the extent of the prethermal regime as a function of the drive amplitude.

Analytic approaches to periodically driven closed quantum systems: methods and applications

We present a brief overview of some of the analytic perturbative techniques for the computation of the Floquet Hamiltonian for a periodically driven, or Floquet, quantum many-body system. The key technical points about each of the methods discussed are presented in a pedagogical manner. They are followed by a brief account of some chosen phenomena where these methods have provided useful insights. We provide an extensive discussion of the Floquet-Magnus (FM) expansion, the adiabatic-impulse approximation, and the Floquet perturbation theory. This is followed by a relatively short discourse on the rotating wave approximation, a FM resummation technique and the Hamiltonian flow method. We also provide a discussion of some open problems which may possibly be addressed using these methods.

Active microrheology using pulsed optical tweezers to probe viscoelasticity of lamin A

Lamins are nucleoskeletal proteins of mammalian cells that stabilize the structure and maintain the rigidity of the nucleus. These type V intermediate filament proteins which are predominantly of A and B types provide necessary tensile strength to the nucleus. Single amino acid missense mutations occurring all over the lamin A protein form a cluster of human diseases termed as laminopathies, most of which principally affect the muscle and cardiac tissues responsible for load bearing functionalities of the body. One such mutation is A350P which causes dilated cardiomyopathy in patients. It is postulated that a change from alanine to proline in the α-helical coiled-coil forming 2B rod domain of the protein might severely disrupt the propensity of the filaments to polymerise into functional higher order structures required to form a fully functional lamina with its characteristic elasticity. In this study, we have elucidated for the very first time, the application of active microrheology employing oscillating optical tweezers to investigate any alterations in the viscoelastic parameters of the mutant protein meshwork in vitro, which might translate into possible changes in nuclear plasticity. We confirmed our findings from this robust yet fast method by imaging both the wild type and mutant lamin A networks using a super resolution microscope, and observed changes in the mesh size which corroborate our measured changes in the viscoelastic parameters of the lamins. This method could thus be extended to conduct microrheological measurements on any intermediate filament protein thus bearing significant implications in laminopathies and other diseases associated with intermediate filaments.

One-dimensional spin-orbit coupled Dirac system with extendeds-wave superconductivity: Majorana modes and Josephson effects

Motivated by the spin-momentum locking of electrons at the boundaries of certain topological insulators, we study a one-dimensional system of spin-orbit coupled massless Dirac electrons withs-wave superconducting pairing. As a result of the spin-orbit coupling, our model has only two kinds of linearly dispersing modes, and we take these to be right-moving spin-up and left-moving spin-down. Both lattice and continuum models are studied. In the lattice model, we find that a single Majorana zero energy mode appears at each end of a finite system provided that thes-wave pairing has an extended form, with the nearest-neighbor pairing being larger than the on-site pairing. We confirm this both numerically and analytically by calculating the winding number. We find that the continuum model also has zero energy end modes. Next we study a lattice version of a model with both Schrödinger and Dirac-like terms and find that the model hosts a topological transition between topologically trivial and non-trivial phases depending on the relative strength of the Schrödinger and Dirac terms. We then study a continuum system consisting of twos-wave superconductors with different phases of the pairing, with aδ-function potential barrier lying at the junction of the two superconductors. Remarkably, we find that the system has asingleAndreev bound state (ABS) which is localized at the junction. When the pairing phase difference crosses a multiple of 2π, an ABS touches the top of the superconducting gap and disappears, and a different state appears from the bottom of the gap. We also study the AC Josephson effect in such a junction with a voltage bias that has both a constantV₀and a term which oscillates with a frequencyω. We find that, in contrast to standard Josephson junctions, Shapiro plateaus appear when the Josephson frequencyω_J= 2eV₀/ℏis a rational fraction ofω. We discuss experiments which can realize such junctions.

Inequality, Familial Aggregation, and Risk Prediction of Caries in Siblings

INTRODUCTION

Social and family conditions are likely of great importance to dental health; however, limited evidence of familial aggregation of caries among adolescent siblings exists. Moreover, social and family-level factors have never been evaluated as isolated caries predictors at the individual level.

OBJECTIVES

The objectives were to evaluate socioeconomic patterning of caries among siblings, assess sibling-specific aggregation of caries within families, and examine if such aggregation differed by parental socioeconomic position (SEP). We also evaluated the discriminant ability of sibling caries, SEP, and other social and familial factors in predicting caries in cosiblings.

METHODS

This nationwide register-based study included all 15-y-olds in Denmark in 2003 (index siblings) and their biological siblings born within ±3 y (cosiblings). Clinical and sociodemographic data for each subject were compiled from Danish national dental, social, and population registers. Caries was measured by the decayed, missing, and filled tooth surfaces (DMFS) index. Predictors included SEP (parental education, income, and occupational social class), gender, birth order, immigration status, and household type. Adjusted SEP-caries associations were estimated using negative binomial regression. Familial aggregation was evaluated using adjusted pairwise odds ratios from alternating logistic regressions. Caries prediction was based on classification and regression tree (CART) analyses.

RESULTS

The study included 23,847 sibling pairs (n = 47,694). Socioeconomic patterning of caries was similar among the index and cosiblings with significant graded SEP-caries associations. Significant sibling-specific aggregation of caries was observed; cosiblings of caries-affected index siblings had odds of having caries 3.9 times (95% confidence interval: 3.65-4.18) as high as that of cosiblings with caries-free index siblings. This sibling similarity was stronger in socioeconomically disadvantaged families (adjusted pairwise odds ratios: 3.08-5.47). CART revealed index sibling caries as the single most important caries predictor, with caries predicted in ≥84% of cosiblings of adolescents with ≥3 carious tooth surfaces.

CONCLUSIONS

Caries in a sibling should prompt preventive family-based approaches targeting cosiblings.

KNOWLEDGE TRANSFER STATEMENT

This study revealed significant socioeconomic patterning of caries in adolescent siblings. Prediction modeling indicated that the single most important caries predictor among cosiblings was index sibling caries. Information on sibling caries level should be routinely combined with clinical evaluation to identify children at risk. Moreover, information on social and family conditions should be used to target prevention and health promotion at the school or municipal level. These approaches could possibly contribute to reducing the existing caries inequalities.

Size-dependent influence of NOx on the growth rates of organic aerosol particles

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Anisotropic transport of normal metal-barrier-normal metal junctions in monolayer phosphorene

We study transport properties of a phosphorene monolayer in the presence of single and multiple potential barriers of height U ₀ and width d, using both continuum and microscopic lattice models, and show that the nature of electron transport along its armchair edge (x direction) is qualitatively different from its counterpart in both conventional two-dimensional electron gas with Schrödinger-like quasiparticles and graphene or surfaces of topological insulators hosting massless Dirac quasiparticles. We show that the transport, mediated by massive Dirac electrons, allows one to achieve collimated quasiparticle motion along x and thus makes monolayer phosphorene an ideal experimental platform for studying Klein paradox in the context of gapped Dirac materials. We study the dependence of the tunneling conductance [Formula: see text] as a function of d and U ₀, and demonstrate that for a given applied voltage V its behavior changes from oscillatory to decaying function of d for a range of U ₀ with finite non-zero upper and lower bounds, and provide analytical expression for these bounds within which G decays with d. We contrast such behavior of G with that of massless Dirac electrons in graphene and also with that along the zigzag edge (y direction) in phosphorene where the quasiparticles obey an effective Schrödinger equation at low energy. We also study transport through multiple barriers along x and demonstrate that these properties hold for transport through multiple barriers as well. Finally, we suggest concrete experiments which may verify our theoretical predictions.

Role of trap-induced scales in non-equilibrium dynamics of strongly interacting trapped bosons

We use a time-dependent hopping expansion technique to study the non-equilibrium dynamics of strongly interacting bosons in an optical lattice in the presence of a harmonic trap characterized by a force constant K. We show that after a sudden quench of the hopping amplitude J across the superfluid (SF)-Mott insulator (MI) transition, the SF order parameter [Formula: see text] and the local density fluctuation [Formula: see text] exhibit sudden decoherence beyond a trap-induced time scale [Formula: see text]. We also show that after a slow linear ramp down of J, [Formula: see text] and the boson defect density [Formula: see text] display a novel non-monotonic spatial profile. Both these phenomena can be explained as consequences of trap-induced time and length scales affecting the dynamics and can be tested by concrete experiments.

Dynamical Detection of Topological Phase Transitions in Short-Lived Atomic Systems

We demonstrate that dynamical probes provide direct means of detecting the topological phase transition (TPT) between conventional and topological phases, which would otherwise be difficult to access because of loss or heating processes. We propose to avoid such heating by rapidly quenching in and out of the short-lived topological phase across the transition that supports gapless excitations. Following the quench, the distribution of excitations in the final conventional phase carries signatures of the TPT. We apply this strategy to study the TPT into a Majorana-carrying topological phase predicted in one-dimensional spin-orbit-coupled Fermi gases with attractive interactions. The resulting spin-resolved momentum distribution, computed by self-consistently solving the time-dependent Bogoliubov-de Gennes equations, exhibits Kibble-Zurek scaling and Stückelberg oscillations characteristic of the TPT. We discuss parameter regimes where the TPT is experimentally accessible.

Statistics of work distribution in periodically driven closed quantum systems

We study the statistics of the work distribution P(w) in a d-dimensional closed quantum system with linear dimension L subjected to a periodic drive with frequency ω(0). We show that the corresponding rate function I(w)=-ln[P(w)/Λ(0)]/L^{d} after a drive period satisfies a universal lower bound I(0)≥n(d) and has a zero at w=QL(d)/N, where n(d) and Q are the excitation and the residual energy densities generated during the drive, Λ(0) is a constant fixed by the normalization of P(w), and N is the total number of constituent particles or spins in the system. We supplement our results by calculating I(w) for a class of d-dimensional integrable models and show that I(w) has an oscillatory dependence on ω(0) originating from Stuckelberg interference generated due to double passage through the critical point or region during the drive. We suggest experiments to test our theory.

A perturbative renormalization group approach to driven quantum systems

We use a perturbative momentum shell renormalization group (RG) approach to study the properties of a driven quantum system at zero temperature. To illustrate the technique, we consider a bosonic ϕ(4) theory with an arbitrary time dependent interaction parameter λ(t) = λ f(ω0t), where ω0 is the drive frequency and we derive the RG equations for the system using a Keldysh diagrammatic technique. We show that the scaling of ω0 is analogous to that of temperature for a system in thermal equilibrium and its presence provides a cutoff scale for the RG flow. We analyze the resultant RG equations, derive an analytical condition for such a drive to take the system out of the gaussian regime, and show that the onset of the non-gaussian regime occurs concomitantly with the appearance of non-perturbative mode coupling terms in the effective action of the system. We supplement the above-mentioned results by obtaining them from equations of motion of the bosons and discuss their significance for systems near critical points described by time-dependent Landau-Ginzburg theories.

Ramp dynamics of phonons in an ion trap: entanglement generation and cooling

We show that the ramp dynamics of phonons in a one-dimensional ion trap can be used for both generating multiparticle entangled states and motional state cooling of a string of trapped ions. We study such ramp dynamics using an effective Bose-Hubbard model which describes these phonons at low energies and show that specific protocols, involving site-specific dynamical tuning of the on-site potential of the model, can be used to generate entangled states and to achieve motional state cooling without involving electronic states of the ions. We compare and contrast our schemes for these to the earlier suggested ones and discuss specific experiments to realize the suggested protocols.

Tunable superlattice in graphene to control the number of Dirac points

Superlattice in graphene generates extra Dirac points in the band structure and their number depends on the superlattice potential strength. Here, we have created a lateral superlattice in a graphene device with a tunable barrier height using a combination of two gates. In this Letter, we demonstrate the use of lateral superlattice to modify the band structure of graphene leading to the emergence of new Dirac cones. This controlled modification of the band structure persists up to 100 K.

Periodic dynamics of fermionic superfluids in the BCS regime

We study the zero temperature non-equilibrium dynamics of a fermionic superfluid in the BCS limit and in the presence of a drive leading to a time-dependent chemical potential μ(t). We choose a periodic driving protocol characterized by a frequency ω and compute the fermion density, the wavefunction overlap, and the residual energy of the system at the end of N periods of the drive. We demonstrate that the BCS self-consistency condition is crucial in shaping the long time behaviour of the fermions subjected to the drive and provide an analytical understanding of the behaviour of the fermion density nkF (where kF is the Fermi momentum vector) after a drive period and for large ω. We also show that the momentum distribution of the excitations generated due to such a drive bears the signature of the pairing symmetry and can be used, for example, to distinguish between s- and d-wave superfluids. We propose experiments to test our theory.

Depth matters: cells grown on nano-porous anodic alumina respond to pore depth

Recent experiments have shown unambiguously that living cells respond to the nano-topography of surfaces they grow on-specifically, the fate of stem cells grown on nano-porous titania or alumina have been shown to be decided by the pore size. However, most experiments have focused on pore size or pitch. Here we show that in addition to pore size and pitch, the depth of the pores has a profound effect on cell morphology and the arrangement of the actin cytoskeleton.

Large variations in the magnetic ordering behavior of EuCu(2)As(2) with the application of external pressure and magnetic field

The influence of external pressure on the electrical transport and magnetic properties of EuCu(2)As(2), crystallizing in a ThCr(2)Si(2)-type structure, is reported. The system is known to be an antiferromagnet below T(N) ≈ 15 K in the absence of external magnetic fields. We find that there is a gradual reduction of T(N) with the application of a magnetic field with an extrapolated value of the critical field of around 18 kOe which can drive T(N) to zero. Electrical resistivity under pressure (<11 GPa) reveals that the magnetic ordering temperature is pushed up dramatically to higher temperatures which is quite interesting if compared with the behavior in isostructural FeAs-based systems containing Eu. Above 7 GPa, the pressure-induced state appears to be ferromagnetic. The results thus reveal interesting changes in the magnetic ordering behavior of this compound with increasing pressure and magnetic fields.

Nonequilibrium dynamics of the Bose-Hubbard model: a projection-operator approach

We study the phase diagram and nonequilibrium dynamics involving ramp of the hopping amplitude J(t)=Jt/τ with ramp time τ of the Bose-Hubbard model at zero temperature using a projection-operator formalism which allows us to incorporate the effects of quantum fluctuations beyond mean-field approximations in the strong-coupling regime. Our formalism yields a phase diagram which provides a near exact match with quantum Monte Carlo results in three dimensions. We also compute the residual energy Q, the superfluid order parameter Δ(t), the equal-time order parameter correlation function C(t), and the wave function overlap F which yields the defect formation probability P during nonequilibrium dynamics of the model. We find that Q, F, and P do not exhibit the expected universal scaling. We explain this absence of universality and show that our results compare well with recent experiments.

Superconductivity in SnO: a nonmagnetic analog to Fe-based superconductors?

We discovered that under pressure SnO with α-PbO structure, the same structure as in many Fe-based superconductors, e.g., β-FeSe, undergoes a transition to a superconducting state for p≳6 GPa with a maximum Tc of 1.4 K at p=9.3 GPa. The pressure dependence of Tc reveals a domelike shape and superconductivity disappears for p≳16 GPa. It is further shown from band structure calculations that SnO under pressure exhibits a Fermi surface topology similar to that reported for some Fe-based superconductors and that the nesting between the hole and electron pockets correlates with the change of Tc as a function of pressure.

Multiprobe experiments under high pressure: resistivity, magnetic susceptibility, heat capacity, and thermopower measurements around 5 GPa

We have performed multiprobe experiments using a Bridgman-anvil pressure cell, adapted to trap Daphne oil as pressure medium. Resistivity, ac-magnetic susceptibility, thermopower, and ac-heat capacity of a type-I superconductor, lead, have been studied at low temperature up to 5+/-0.1 GPa. This is the first report where ac-magnetic susceptibility has been measured in this type of pressure cell and at such a high pressure range. The signature of the superconducting transition temperature, obtained from all these different measurements, agrees well within the experimental errors.

Tuning the conductance of dirac fermions on the surface of a topological insulator

We study the transport properties of the Dirac fermions with a Fermi velocity v{F} on the surface of a topological insulator across a ferromagnetic strip providing an exchange field J over a region of width d. We show that the conductance of such a junction, in the clean limit and at low temperature, changes from oscillatory to a monotonically decreasing function of d beyond a critical J. This leads to the possible realization of a magnetic switch using these junctions. We also study the conductance of these Dirac fermions across a potential barrier of width d and potential V0 in the presence of such a ferromagnetic strip and show that beyond a critical J, the criteria of conductance maxima changes from chi=eV{0}d/variant Planck's over v{F}=npi to chi=(n+1/2)pi for integer n. We point out that these novel phenomena have no analogs in graphene and suggest experiments which can probe them.

Spontaneous spin accumulation in singlet-triplet josephson junctions

We study the Andreev bound states in a Josephson junction between a singlet and a triplet superconductors. Because of the mismatch in the spin symmetries of pairing, the energies of the spin-up and -down quasiparticles are generally different. This results in imbalance of spin populations and net spin accumulation at the junction in equilibrium. This effect can be detected using probes of local magnetic field, such as the scanning SQUID, Hall, and Kerr probes. It may help to identify potential triplet pairing in (TMTSF)2X, Sr2RuO4, and oxypnictides.

Defect production in nonlinear quench across a quantum critical point

We show that the defect density n, for a slow nonlinear power-law quench with a rate tau(-1) and an exponent alpha>0, which takes the system through a critical point characterized by correlation length and dynamical critical exponents nu and z, scales as n approximately tau(-alphanud/(alphaznu+1)) [n approximately (alphag((alpha-1)/alpha)/tau)(nud/(znu+1))] if the quench takes the system across the critical point at time t=0 [t=t(0) not = 0], where g is a nonuniversal constant and d is the system dimension. These scaling laws constitute the first theoretical results for defect production in nonlinear quenches across quantum critical points and reproduce their well-known counterpart for a linear quench (alpha=1) as a special case. We supplement our results with numerical studies of well-known models and suggest experiments to test our theory.

Exact results for quench dynamics and defect production in a two-dimensional model

We show that for a d-dimensional model in which a quench with a rate tau(-1) takes the system across a (d-m)-dimensional critical surface, the defect density scales as n approximately 1/tau(mnu/(znu+1)), where nu and z are the correlation length and dynamical critical exponents characterizing the critical surface. We explicitly demonstrate that the Kitaev model provides an example of such a scaling with d = 2 and m = nu = z = 1. We also provide the first example of an exact calculation of some multispin correlation functions for a two-dimensional model that can be used to determine the correlation between the defects. We suggest possible experiments to test our theory.

Tunneling conductance of graphene NIS junctions

We show that, in contrast with conventional normal metal-insulator-superconductor (NIS) junctions, the tunneling conductance of a NIS junction in graphene is an oscillatory function of the effective barrier strength of the insulating region, in the limit of a thin barrier. The amplitude of these oscillations is maximum for aligned Fermi surfaces of the normal and superconducting regions and vanishes for a large Fermi surface mismatch. The zero-bias tunneling conductance, in sharp contrast to its counterpart in conventional NIS junctions, becomes maximum for a finite barrier strength. We also suggest experiments to test these predictions.

Hard-core bosons on the kagome lattice: valence-bond solids and their quantum melting

Using large scale quantum Monte Carlo simulations and dual vortex theory, we analyze the ground state phase diagram of hard-core bosons on the kagome lattice with nearest-neighbor repulsion. In contrast with the case of a triangular lattice, no supersolid emerges for strong interactions. While a uniform superfluid prevails at half filling, two novel solid phases emerge at densities rho=1/3 and rho=2/3. These solids exhibit an only partial ordering of the bosonic density, allowing for local resonances on a subset of hexagons of the kagome lattice. We provide evidence for a weakly first-order phase transition at the quantum melting point between these solid phases and the superfluid.

Characterization of entamoeba histolytica antigens in circulating immune complexes in sera of patients with amoebiasis

Isolated circulating immune complexes (CICs) from sera of patients with amoebiasis were characterized to determine Entamoeba histolytica antigens that participate in the disease process. In total, 116 serum samples were collected before starting anti-amoebic therapy, and their CICs were isolated by differential polyethylene glycol precipitation. The presence of amoeba-specific antigens in CICs was detected by antigen capture enzyme-linked immunosorbent assay (ELISA) and by immunoblot assay. Antigen capture ELISA showed significantly higher optical density (p < 0.001) in all patients with amoebiasis than in the normal healthy controls and patients of non-amoebic hepatic disorder. Immunoblot assay detected amoeba-specific CICs in all 18 patients (100%) with confirmed amoebic liver abscess, 28 (80%) of 35 patients with clinically-suspected amoebic liver abscess, and 18 (78.26%) of 23 patients with amoebic colitis. No patients with non-amoebic hepatic disorders and healthy control subjects had any detectable level of amoebic antigens in CICs. Immunoblot assay revealed E. histolytica antigens of relative molecular masses of 35, 56, 70, and 90 kDa present in CICs of 64 of 76 patients with amoebiasis. The 35-kDa polypeptide was observed in 52 patients (81.25%). The results of the study suggest that the 35-kDa polypeptide antigen can be a diagnostic marker in active amoebiasis.

Differential expression of WISP-1 and WISP-2 genes in normal and transformed human breast cell lines

The transcriptional alterations of specific gene(s) are actively associated with the development of different cancers including breast. The preceding studies of different laboratories documented at least 40 genes that may contribute directly to the genesis of cancer. Using differential display, RT-PCR and DNA sequencing analyses in normal human mammary epithelial cells (HMEC) and various breast tumor cell lines including MCF-7, ZR-75, T-47D and SKBR2, we demonstrated that WISP-1 and WISP-2 genes are differentially transcribed in these cells. WISP-2 mRNA transcription was identified in all 4 tumor derived cell lines, but the mRNA expression was undetected or minimally detected in normal breast epithelial cells. WISP-1 mRNA expression was identified in normal and transformed cell lines. However, the level of expression was higher in different breast tumor cell lines as compared to HMEC. The mRNA expression profiles of WISP genes in normal breast epithelial cells and breast tumor derived cell lines indicated a strong possibility of the involvement of WISP-signaling in the development of human breast tumors, and can be utilized as genetic markers of this disease.

Role of tilt order in the asymmetric ripple phase of phospholipid bilayers

We present the electron density map of the asymmetric ripple phase of dilauroylphosphatidylcholine. We find that the primary feature characterizing the "asymmetry" of the rippled bilayers is the difference in the bilayer thickness in the two arms, and not the asymmetry of the bilayer height profile as is generally assumed. This difference in the bilayer thickness can be attributed to a mean tilt of the hydrocarbon chains of the lipid molecules along the direction of the ripple wave vector. We propose a Landau theory for this phase which takes into account the anisotropic elastic properties of a bilayer with tilt order.

Entamoeba histolytica: monoclonal antibody against the beta1 integrin-like molecule (140 kDa) inhibits cell adhesion to extracellular matrix components

We describe a monoclonal antibody (3C10) against the beta1 integrin-like molecule which immunoprecipitates two polypeptides of 140 and 155 kDa from detergent-soluble extract of Entamoeba histolytica. The 140-kDa polypeptide has been described as a beta subunit of the amoebic fibronectin receptor as it is recognized by an anti-integrin beta1 (human) monoclonal antibody in immunoblot assay. The receptor molecules were localized with the 3C10 monoclonal antibody in intracellular and surface membranes of E. histolytica trophozoites by immunofluorescence and immunogold labeling methods. Significant inhibitions of cell adhesion on extracellular matrix proteins such as fibronectin (56%) (P < 0.001) and collagen (50%) (P < 0.001) and partial inhibition on laminin (23%) (P > 0.1) were achieved by the monoclonal antibody.

Edge electron states for quasi-one-dimensional organic conductors in the magnetic-field-induced spin-density-wave phases

We develop a microscopic picture of the electron states localized at the edges perpendicular to the chains in the Bechgaard salts in the quantum Hall regime. In a magnetic-field-induced spin-density-wave state characterized by an integer N, there exist N branches of chiral gapless edge excitations. Localization length is much longer and velocity much lower for these states than for the edge states parallel to the chains. We calculate the contribution of these states to the specific heat and propose a time-of-flight experiment to probe the propagating edge modes directly.

Therapeutic and prophylactic uses of protein A in the control of Leishmania donovani infection in experimental animals

The role of the immunomodulator Protein A (PA) (from Staphylococcus aureus, Cowan I strain) in the control of leishmanial infection was studied in experimental animals. Treatment of Leishmania donovani infected hamsters with PA led to a moderate level of reduction of parasite load in their spleen (68%) and liver (46%). However, combination therapy of PA with the antileishmanial drug stibanate induced a more marked reduction of the spleen (88%) and liver (85%) parasitemia compared to that induced by PA or drug treatment alone. Similar results were also obtained with L. donovani infected BALB/c mice as the combination therapy of PA and stibanate led to a significant reduction (84%) of liver parasite load in comparison to that induced by PA (38%) or drug (61%) treatment alone. Apart from its therapeutic use, PA could also be used as a prophylactic agent in the control of leishmanial infection. Thus, treatment of hamsters with PA before leishmanial challenge significantly reduced their organ parasite load (by 59-78%) compared to that observed in infected controls without prior PA treatment. The antileishmanial effect of PA was likely to be mediated through the activation of macrophages leading to an enhancement of their phagocytic as well as leishmaniacidal activities. Subsequent studies demonstrated that PA treatment led to an increased production of nitric oxide by macrophages which could primarily be responsible for their enhanced parasite killing ability.

Antigens of diagnostic and prophylactic importance inEntamoeba histolytica

Amoebiasis, caused by an enteric protozoanEntamoeba histolytica, is one of the major parasitic diseases of mankind. Current estimate suggests that the parasite infects about 10% of the world population at any given time. There is an urgent need to characterize the antigenic molecules ofE. histolytica, and find out antigens which have both immunodiagnostic and prophylactic potential against amoebiasis. The results of somatic antigen analysis, using sera from immune or infected individuals, indicated that the wholeE. histolytica trophozoites, are highly complex and heterogeneous in nature and both immunodiagnostic and immuno prophylaxis activity remain mainly in a surface associated 29 kDa glycoprotein ofE. histolytica. Future studies at molecular level particularly, genes responsible for expression of this protein, their homology with other proteins and structure analysis will give better understanding about this polypeptide. Studies on excretory secretory antigens, clearly demonstrated thatE. histolytica like many organisms, also liberates certain antigenic moieties into the culture medium during in vitro cultivation and this antigen has similar diagnostic values like the conventional somatic antigens. It is important that the ESA should be prepared from the supernatant after collecting the cell and use for immunodiagnosis of amoebiasis. This is an additional source of antigen which will help in carrying out more tests using the same reagents. Further studies are needed to clarify the location of these molecules on the parasite, along with detailed biochemical and immunological characterization and their relation with the pathogenesis.

Transient immunosuppression with FK506 permits long-term expression of therapeutic genes introduced into the liver using recombinant adenoviruses in the rat

The host immune response limits the duration of expression of adenovirally transduced genes and precludes long-term gene expression upon re-administration of the virus. In this study we wished to evaluate whether short-term immunosuppression of the host, at the time of recombinant virus administration, would allow expression of the therapeutic gene product upon virus reinjection. Gunn rats were used as recipients of recombinant adenoviruses expressing human BUGT (Ad-hBUGT) or E. coli beta-galactosidase (Ad-LacZ). Rats were treated with FK506 (1-1.5 mg/kg, per OS daily) for three days beginning 24 hours before each virus injection. Control groups did not receive any immunosuppressant. The serum bilirubin level was reduced from 7.1 +/- 0.75 mg/dL to 2.0 +/- 0.7 mg/dL within two days of viral injection in both FK506 treated and control groups, and then gradually increased in 6 weeks. FK506-treated rats had low or undetectable antibody titers against the recombinant adenovirus and minimal or no cytotoxic T lymphocyte (CTL) response against adenovirus-infected cells. The tolerized rats received two subsequent injections 42 and 98 days after the first injection, which reduced the bilirubin levels again to 2.0 +/- 0.56 and 2.2 +/- 0.61 mg/dL, respectively. In contrast, control rats developed high titer neutralizing antibodies and a CTL response, and their serum bilirubin levels were not reduced following subsequent injections. We conclude that short-term FK506 treatment around the time of virus administration prevents the host immune response, permitting long-term gene therapy by repeated administration of the recombinant virus.