Predicting response to peginterferon alpha-2a, lamivudine and the two combined for HBeAg-negative chronic hepatitis B

OBJECTIVE

In a trial of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B, 24 week post-treatment biochemical and virological response rates with peginterferon alpha-2a with or without lamivudine were significantly higher than with lamivudine alone. The effect of pre-treatment factors on post-treatment responses was investigated.

METHODS

Multivariate analyses were performed using available data from 518 patients treated with peginterferon alpha-2a with or without lamivudine, or with lamivudine alone. A post-treatment response was defined as alanine aminotransferase (ALT) normalisation and hepatitis B virus (HBV) DNA level of <20,000 copies/ml.

RESULTS

In logistic regression analyses across all treatment arms, peginterferon alpha-2a (with or without lamivudine) therapy, younger age, female gender, high baseline ALT, low baseline HBV DNA and HBV genotype were identified as significant predictors of combined response at 24 weeks post-treatment. In the peginterferon alpha-2a and lamivudine monotherapy arms, patients with genotypes B or C had a higher chance of response than genotype D infected patients (p<0.001), the latter responding better to the combination than to peginterferon alpha-2a monotherapy (p = 0.015). At 1 year post-treatment, response rates by intention-to-treat analysis were 19.2% for the peginterferon alpha-2a, 19.0% for the combination, and 10.0% for the lamivudine groups, with genotypes B or C associated with a sustained combined response to peginterferon alpha-2a with or without lamivudine therapy.

CONCLUSIONS

Baseline ALT and HBV DNA levels, patient age, gender, and infecting HBV genotype significantly influenced combined response at 24 weeks post-treatment, in patients treated with peginterferon alpha-2a and/or lamivudine. At 1 year post-treatment HBV genotype was significantly predictive of efficacy for patients treated with peginterferon alpha-2a with or without lamivudine.

Cross-national prevalence and correlates of adult attention-deficit hyperactivity disorder

BACKGROUND

Little is known about the epidemiology of adult attention-deficit hyperactivity disorder (ADHD).

AIMS

To estimate the prevalence and correlates of DSM-IV adult ADHD in the World Health Organization World Mental Health Survey Initiative.

METHOD

An ADHD screen was administered to respondents aged 18-44 years in ten countries in the Americas, Europe and the Middle East (n=11422). Masked clinical reappraisal interviews were administered to 154 US respondents to calibrate the screen. Multiple imputation was used to estimate prevalence and correlates based on the assumption of cross-national calibration comparability.

RESULTS

Estimates of ADHD prevalence averaged 3.4% (range 1.2-7.3%), with lower prevalence in lower-income countries (1.9%) compared with higher-income countries (4.2%). Adult ADHD often co-occurs with other DSM-IV disorders and is associated with considerable role disability. Few cases are treated for ADHD, but in many cases treatment is given for comorbid disorders.

CONCLUSIONS

Adult ADHD should be considered more seriously in future epidemiological and clinical studies than is currently the case.

The cystic fibrosis transmembrane conductance regulator (Cftr) modulates the timing of puberty in mice

BACKGROUND

Delayed puberty is common among individuals with cystic fibrosis (CF) and is usually attributed to chronic disease and/or poor nutrition. However, it has recently been recognised that pubertal delay can occur even in the setting of good nutritional and clinical status. This finding, along with evidence that Cftr is expressed in rat brain, human hypothalamus, and a gonadotropin releasing hormone secreting cell line, raises the possibility that some of the pubertal delay in CF could stem directly from alterations in Cftr function that affect the hypothalamic-pituitary-gonadal axis.

METHODS

To examine this hypothesis, we investigated pubertal timing (as assessed by vaginal opening (VO)) in a mouse model of CF (Cftr(tm1Unc)) engineered to produce a truncated Cftr mRNA and referred to as S489X. Homozygous knockout, heterozygote, and wild type (WT) female mice were examined.

RESULTS

As expected, the S489X-/S489X- knockout mice, which have chronic inflammation and gastrointestinal disease, grew more slowly and had later onset of puberty than WT animals. We anticipated that the S489X-/S489X+ heterozygotes, which have no clinical CF phenotype, might display an intermediate timing of puberty. Surprisingly, however, these mice had earlier VO than WT. These findings were confirmed in a second, independent model of CF engineered to generate the deltaF508 mutation in mice. Again, the homozygotes displayed later pubertal timing, while the heterozygotes displayed earlier VO than the WT animals.

CONCLUSIONS

These data provide further evidence that Cftr can directly modulate the reproductive endocrine axis and raise the possibility that heterozygote mutation carriers may have a reproductive advantage.

New Luttinger-liquid physics from photoemission on Li0.9M06O17

Temperature dependent high resolution photoemission spectra of quasi-one-dimensional Li(0.9)Mo(6)O(17)evince a strong renormalization of its Luttinger-liquid density-of-states anomalous exponent. We trace this new effect to interacting charge neutral critical modes that emerge naturally from the two-band nature of the material. Li(0.9)Mo(6)O(17) is shown thereby to be a paradigm material that is capable of revealing new Luttinger physics.

Dopant-induced nanoscale electronic inhomogeneities in Ca(2-x)Sr(x)RuO4

Ca(2-x)Sr(x)RuO4 single crystals with 0.1 < or = x < or = 2.0 have been studied systematically using scanning tunneling microscopy (STM) and spectroscopy, low-energy electron diffraction, and angle resolved photoelectron spectroscopy (ARPES). In contrast with the well-ordered lattice structure, the local density of states at the surface clearly shows a strong doping dependent nanoscale electronic inhomogeneity, regardless of the fact of isovalent substitution. Remarkably, the surface electronic roughness measured by STM and the inverse spectral weight of quasiparticle states determined by ARPES are found to vary with x in the same manner as the bulk in-plane residual resistivity, following the Nordheim rule. For the first time, the surface measurements--especially those with STM--are shown to be in good agreement with the bulk transport results, all clearly indicating a doping-induced electronic disorder in the system.

Non-fermi-liquid behavior in quasi-one-dimensional Li0.9Mo6O17

We present temperature dependent scanning tunneling spectroscopy data of the quasi-one-dimensional conductor Li0.9Mo6O17. The differential tunneling current in our low-temperature spectra shows a power-law behavior around the Fermi energy, which is expected for a clean Luttinger liquid. The power-law exponent is found to be 0.6. Spectra for a temperature range of 5 to 55 K can be fitted fairly well with a model for tunneling into a Luttinger liquid at the appropriate temperature. A fit with a model based on a zero bias anomaly is significantly worse compared to the Luttinger liquid model. No signature of a phase transition at T = 24 K is observed in our temperature dependent data.

Fermi surface evolution and Luttinger theorem in Na(x)CoO2: a systematic photoemission study

We report a systematic angle-resolved photoemission study on Na(x)CoO2 for a wide range of Na concentrations (0.3 < or = x < or = 0.72). In all the metallic samples at different x, we observed (i) only a single holelike Fermi surface centered around gamma and (ii) its area changes with x according to the Luttinger theorem. We also observed a surface state that exhibits a larger Fermi surface area. The e'(g) band and the associated small Fermi surface pockets near the K points predicted by band calculations are found to sink below the Fermi energy in a manner almost independent of the doping and temperature.

Goldstone-mode phonon dynamics in the pyrochlore Cd2Re2O7

We have measured the polarized Raman scattering spectra of Cd2Re2O7, the first superconducting pyrochlore, as a function of temperature. For temperatures below the cubic-to-tetragonal structural phase transition (SPT) at 200 K, a peak with B1 symmetry develops at zero frequency with divergent intensity. We identify this peak as the first observation of the Goldstone phonon in a crystalline solid. The Goldstone phonon is a collective excitation that exists due to the breaking of the continuous symmetry with the SPT. Its emergence coincides with that of a Raman-active soft mode. The order parameter for both features derives from an unstable doubly degenerate vibration (with Eu symmetry) of the O1 atoms which drives the SPT.

Fermi surface topology of Ca1.5Sr0.5RuO4 determined by angle-resolved photoelectron spectroscopy

We report angle-resolved photoelectron spectroscopy results of the Fermi surface of Ca1.5Sr0.5RuO4, which is at the boundary of magnetic/orbital instability in the phase diagram of the Ca-substituted Sr ruthenates. Three t(2g) energy bands and the corresponding Fermi surface sheets are observed, which are also present in the Ca-free Sr2RuO4. We find that while the Fermi surface topology of the alpha,beta (d(yz,zx)) sheets remains almost the same in these two materials, the gamma (d(xy)) sheet exhibits a holelike Fermi surface in Ca1.5Sr0.5RuO4 in contrast to being electronlike in Sr2RuO4. Our observation of all three volume conserving Fermi surface sheets clearly demonstrates the absence of orbital-selective Mott transition, which was proposed theoretically to explain the unusual transport and magnetic properties in Ca1.5Sr0.5RuO4.

ARPES on Na0.6CoO2: Fermi surface and unusual band dispersion

The electronic structure of single crystals Na0.6CoO2, which are closely related to the superconducting Na0.3CoO2.yH(2)O (T(c) approximately 5 K), is studied by angle-resolved photoelectron spectroscopy. While the measured Fermi surface (FS) is consistent with the large FS enclosing the Gamma point from the band theory, the predicted small FS pockets near the K points are absent. In addition, the band dispersion is found to be highly renormalized, and anisotropic along the two principal axes (Gamma-K, Gamma-M). Our measurements also indicate that an extended flatband is formed slightly above E(F) along Gamma-K.

Metallic "ferroelectricity" in the pyrochlore Cd2Re2O7

A class of materials known as "ferroelectric metals" was discussed theoretically by Anderson and Blount in 1965 [Phys. Rev. Lett. 14, 217 (1965)]], but to date no examples of this class of materials have been reported. Here we present measurements of the elastic moduli of Cd2Re2O7 through the 200 K cubic-to-tetragonal phase transition. A Landau analysis of the moduli reveals that the transition is consistent with Cd2Re2O7 being classified as a ferroelectric metal in the weaker sense described by Anderson and Blount (loss of a center of symmetry). First-principles calculations of the lattice instabilities indicate that the dominant lattice instability corresponds to a twofold degenerate mode with E(u) symmetry and that motions of the O ions forming the O octahedra dominate the energetics of the transition.

Observation of bulk superconductivity in NaxCoO2.yH(2)O and NaxCoO2.yD(2)O powder and single crystals

Poly- and single-crystalline NaxCoO2 has been successfully intercalated with H2O and D2O as confirmed by x-ray diffraction and thermogravimetric analysis. Resistivity, magnetic susceptibility, and specific heat measurements show bulk superconductivity with T(c) close to 5 K in both cases. The substitution of deuterium for hydrogen has an effect on T(c) of less than 0.2 K. Investigation of the resistivity anisotropy of NaxCoO2.yH(2)O single crystals shows (a). almost zero resistivity below T(c), and (b). an abrupt upturn at T(*) approximately 52 K in both the ab plane and the c direction. The implications of our results on the possible superconducting mechanism will be discussed.

In-plane thermal conductivity of Nd2CuO4: evidence for magnon heat transport

We report the temperature and magnetic field dependence of the in-plane thermal conductivity (kappa(ab)) of high-quality monocrystalline Nd2CuO4. Isothermal measurements of the field dependence of kappa(ab) at low temperatures (2 K<or=T<or=5 K) show no change in kappa(ab) below a critical magnetic field H(c) (H(c) approximately 4.5 T for H parallel [100]) and H(c) approximately 2.5 T for H approximately parallel [110]). Above H(c), kappa(ab) more than doubles as H is increased to 9 T. At H(c), there is a transition from a noncollinear to a collinear arrangement of the Nd and Cu spins and a collapse of the gap, Delta, in an acoustic magnon branch at k=0. Closure of this gap appears to allow the conduction of substantial amounts of heat by acoustic magnons.

Temperature dependence of the magnetic penetration depth in the vortex state of the pyrochlore superconductor, Cd2Re2O7

We report transverse-field and zero-field muon spin rotation and relaxation studies of the superconducting rhenium oxide pyrochlore, Cd2Re2O7. Transverse-field measurements (H=0.007 T) show line broadening below T(c), which is characteristic of a vortex state, demonstrating conclusively the type-II nature of this superconductor. The penetration depth is seen to level off below about 400 mK (T/T(c) approximately 0.4), with a rather large value of lambda(T=0) approximately 7500 A. The temperature independent behavior below approximately 400 mK is consistent with a nodeless superconducting energy gap. Zero-field measurements indicate no static magnetic fields developing below the transition temperature.

Orbital ordering transition in La4Ru2O10

We report experimental evidence for a full orbital ordering transition in the two-dimensional lanthanum ruthenate La4Ru2O10. The observable consequences of this orbital ordering include the loss of the Ru local moment, a structural distortion which partitions Ru-O bonds into axially oriented short and long sets, a sharp jump in electrical resistivity, and the opening of a spin gap that is visible in neutron scattering experiments. This is a rare example of a discrete orbital ordering transition in a 4d transition metal oxide and demonstrates that orbital effects can have an influence on the properties of layered ruthenates, a family of compounds that notably includes the p-wave superconductor Sr2RuO4 and the field-tuned quantum critical metamagnet Sr3Ru2O7.

Structural basis for AMPA receptor activation and ligand selectivity: crystal structures of five agonist complexes with the GluR2 ligand-binding core

Glutamate is the principal excitatory neurotransmitter within the mammalian CNS, playing an important role in many different functions in the brain such as learning and memory. In this study, a combination of molecular biology, X-ray structure determinations, as well as electrophysiology and binding experiments, has been used to increase our knowledge concerning the ionotropic glutamate receptor GluR2 at the molecular level. Five high-resolution X-ray structures of the ligand-binding domain of GluR2 (S1S2J) complexed with the three agonists (S)-2-amino-3-[3-hydroxy-5-(2-methyl-2H-tetrazol-5-yl)isoxazol-4-yl]propionic acid (2-Me-Tet-AMPA), (S)-2-amino-3-(3-carboxy-5-methylisoxazol-4-yl)propionic acid (ACPA), and (S)-2-amino-3-(4-bromo-3-hydroxy-isoxazol-5-yl)propionic acid (Br-HIBO), as well as of a mutant thereof (S1S2J-Y702F) in complex with ACPA and Br-HIBO, have been determined. The structures reveal that AMPA agonists with an isoxazole moiety adopt different binding modes in the receptor, dependent on the substituents of the isoxazole. Br-HIBO displays selectivity among different AMPA receptor subunits, and the design and structure determination of the S1S2J-Y702F mutant in complex with Br-HIBO and ACPA have allowed us to explain the molecular mechanism behind this selectivity and to identify key residues for ligand recognition. The agonists induce the same degree of domain closure as AMPA, except for Br-HIBO, which shows a slightly lower degree of domain closure. An excellent correlation between domain closure and efficacy has been obtained from electrophysiology experiments undertaken on non-desensitising GluR2i(Q)-L483Y receptors expressed in oocytes, providing strong evidence that receptor activation occurs as a result of domain closure. The structural results, combined with the functional studies on the full-length receptor, form a powerful platform for the design of new selective agonists.

Magnetic field enhancement of heat transport in the 2D Heisenberg antiferromagnet K2V3O8

The thermal conductivity and heat capacity of single crystals of the spin 1/2 quasi-2D Heisenberg antiferromagnet K(2)V(3)O(8) have been measured from 1.9 to 300 K in magnetic fields from 0 to 8 T. The zero field thermal conductivity data are consistent with resonant scattering of phonons by magnons near the zone boundary. Application of a magnetic field greater than 1 T, however, produces a new magnetic ground state with substantial heat transport by long wavelength magnons.

[Experimental and clinical studies of recombinant human growth hormone treatement of hypoproteinemia of liver cirrhosis patients]

BACKGROUND

To assess the effect of recombinant human growth hormone (rhGH) therapy to liver cirrhosis patients with hypoproteinemia.

METHODS

31 liver cirrhosis patients were treated with rh GH (0.25 IU/kg/day-) and 20 such patients with human albumin (10 g/day) as control all for 10 days. Serum levels of growth hormone (GH), insulin-like growth factor (IGF)-1 and albumin (ALB) were measured by radio-immunoassay before 24h and after 24h and 10 days of rhGH therapy. Serum levels of GH and IGF-1 of 10 age matched healthy subjects were also measured.

RESULTS

As compared with healthy subjects, the pretreatment serum GH level of liver cirrhosis patients was high (4.96 +/- 3.97 vs 1.62 +/- 2.26, P <0.05), and the IGF-1 level was markedly lower (36.53 +/- 12.77 vs 56.95 +/- 16.46, P <0.01). After 10 days of rhGH administration, the serum IGF-1 and ALB levels of the treated group increased significantly as compared with the control group (P <0.01).

CONCLUSIONS

Exogenous rhGH therapy can overcome the GH resistance of liver cirrhosis patient s and can increase significantly the serum albumin level as compared with the control group who were treated with human albumin only.

[Study on the effects of increased iodized salt intake on the incidence of thyroid diseases]

OBJECTIVE

To study the annual incidence of thyroid diseases before and after the increase of iodized salt intake.

METHOD

A total of 26,010 persons were examined from mid August to the end of December in 1999.

RESULTS

1. Three hundred and ten patients of thyroid diseases were identified from 1990 to July 1999. One hundred and eighty-three patients were diagnosed after iodine supplementation. 2. The constitution of thyroid diseases had changed significantly regarding the increase of hyperthyroidism, simple goiter and thyroid nodule. 3. Fifty-five patients with hyperthyroidism including 39 patients (70.91%) receiving iodine supplementation were diagnosed. The average annual incidence of hyperthyroidism after iodine supplementation was 36.87 per 100,000, a three-time increase as compared with that before iodine supplementation. The incidence of hyperthyroidism began to show a significant rise in 1996. The year with highest annual incidence was 1997, remaining at high level after supplying iodized salt. Since then the annual relative risk for hyperthyroidism had been increasing.

CONCLUSION

The number of patients with thyroid diseases showed a significant increase after mass iodine supplement. At the same time, the spectrum of thyroid diseases had also changed. Iodized salt intake and the incidence of hyperthyroidism showed a significant correlation. However, the typical model of the change of disease patterns incidence needs further study.