Integrable open boundary conditions for the Bariev model of three coupled X Y spin chains

The integrable open-boundary conditions for the Bariev model of three coupled one-dimensional XY spin chains are studied in the framework of the boundary quantum inverse scattering method. Three kinds of diagonal boundary K-matrices leading to nine classes of possible choices of boundary fields are found and the corresponding integrable boundary terms are presented explicitly. The boundary Hamiltonian is solved by using the coordinate Bethe ansatz technique and the Bethe ansatz equations are derived. (C) 2001 Elsevier Science B.V. All rights reserved.

Bcl-X-L translocation in renal tubular epithelial cells in vitro protects distal cells from oxidative stress

Background. The molecular pathogenesis of different sensitivities of the renal proximal and distal tubular cell populations to ischemic injury, including ischemia-reperfusion (IR)-induced oxidative stress, is not well-defined. An in vitro model of oxidative stress was used to compare the survival of distal [Madin-Darby canine kidney (MDCK)] and proximal [human kidney-2 (HK-2)] renal tubular epithelial cells, and to analyze for links between induced cell death and expression and localization of selected members of the Bcl-2 gene family (anti-apoptotic Bcl-2 and Bcl-X-L, pro-apoptotic Bax and Bad), Methods. Cells were treated with 1 mmol/L hydrogen peroxide (H2O2) Or were grown in control medium for 24 hours. Cell death (apoptosis) was quantitated using defined morphological criteria. DNA gel electrophoresis was used for biochemical identification. Protein expression levels and cellular localization of the selected Bcl-2 family proteins were analyzed (West ern immunoblots, densitometry, immunoelectron microscopy). Results. Apoptosis was minimal in control cultures and was greatest in treated proximal cell cultures (16.93 +/- 4.18% apoptosis) compared with treated distal cell cultures (2.28 +/- 0.85% apoptosis, P < 0.001). Endogenous expression of Bcl-X-L and Bax, but not Bcl-2 or Bad, was identified in control distal cells, Bcl-X-L and Bax had nonsignificant increases (P > 0.05) in these cells. Bcl-2, Bax, and Bcl-X-L, but not Bad, were endogenously expressed in control proximal cells. Bcl-X-L was significantly decreased in treated proximal cultures (P < 0.05), with Bas and Bcl-2 having nonsignificant increases (P > 0.05). Immunoelectron microscopy localization indicated that control and treated hut surviving proximal cells had similar cytosolic and membrane localization of the Bcl-2 proteins. In comparison, surviving cells in the treated distal cultures showed translocation of Bcl-X-L from cytosol to the mitochondria after treatment with H2O2, a result that was confirmed using cell fractionation and analysis of Bcl-XL expression levels of the membrane and cytosol proteins. Bax remained distributed evenly throughout the surviving distal cells, without particular attachment to any cellular organelle. Conclusion. The results indicate that in this in vitro model, the increased survival of distal compared with proximal tubular cells after oxidative stress is best explained by the decreased expression of anti-apoptotic Bcl-X-L in proximal cells, as well as translocation of Bcl-X-L protein to mitochondria within the surviving distal cells.

X-ray fluorescence with synchrotron radiation to elemental analysis of lead and calcium content of primary teeth

Primary teeth were analyzed by micro-SRXRF. The aim of this study was to determine the elemental distribution of lead and calcium in different regions of primary incisor of children living in a notoriously contaminated area (Santo Amaro da Purificacao, Bahia State, Brazil). The measurements were performed in standard geometry of 45 incidence, exciting with a white beam and using a conventional system collimation (orthogonal slits) in the XRF beamline at the Synchrotron Light National Laboratory (Campinas, Brazil). (C) 2009 Elsevier Ltd. All rights reserved.

Increased circulating levels of matrix metalloproteinase (MMP)-8, MMP-9, and pro-inflammatory markers in patients with metabolic syndrome

Background: Metabolic syndrome (MetS) predisposes to cardiovascular complications. Increased concentrations of pro-inflammatory mediators and imbalanced concentrations of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) may reflect the pathophysiology of MetS. We compared the circulating levels of MMPs, TIMPs, and inflammatory mediators in MetS patients with those found in healthy controls. Methods: We studied 25 healthy subjects and 25 MetS patients. The plasma levels of pro-MMP-2 and pro-MMP-9 were determined by gelatin zymography. The plasma concentrations of MMP-8, MMP-3, TIMP-1, TIMP-2, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), intercellular adhesion molecule (sICAM-1), and sP-selectin were measured by ELISA kits. Results: We found higher sP-selectin, sICAM-1, MCP-1, and IL-6 (all P<0.05) concentrations in MetS patients compared with healthy controls. No differences in pro-MMP-2, MMP-3, and TIMP-2 levels were found (all P>0.05). However, we found higher pro-MMP-9, MMP-8. and TIMP-1 levels in MetS patients compared with healthy controls (all P<0.05). Conclusions: Patients with MetS have increased circulating concentrations of pro-MMP-9, MMP-8, and TIMP-1 that are associated with increased concentrations of pro-inflammatory mediators and adhesion molecules. These findings suggest that MMPs may have a role in the increased cardiovascular risk of MetS patients. Pharmacological interventions targeting MMPs, especially MMP-9 and MMP-8 deserve further investigation in MetS patients. (C) 2009 Elsevier B.V. All rights reserved.

Growth hormone therapy in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) was originally described less than 50 y ago,1 although reference to children with characteristics of the syndrome are to be found in other literature previous to this.2 Until relatively recently the diagnosis was made upon the clinical features as outlined by Holm,3 which include severe muscular hypotonia in the neonatal period leading to feeding difficulties and undernutrition, hypogonadism and later hyperphagia and obesity. Latterly the syndrome has been identified as being associated with an interstitial deletion of the q11-13 region on chromosome 15.4 In the majority of cases the deletion is in the paternally derived chromosome. In the remainder of cases there seems to be a failure to inherit the entire paternal chromosome and as a consequence both the chromosomes inherited are maternal, thus leading to maternal disomy.

Height discordance in monozygotic females is not attributable to discordant inactivation of X-linked stature determining genes

We tested the hypothesis that X-linked genes determining stature which are subject to skewed or non-random X-inactivation can account for discordance in height in monozygotic female twins. Height discordant female monozygotic adult twins (20 pairs) were identified from the Australian Twin Registry, employing the selection criteria of proven monozygosity and a measured height discordance of at least 5 cm. Differential X-inactivation was examined in genomic DNA extracted from peripheral lymphocytes by estimating differential methylation of alleles at the polymorphic CAG triplet repeat of the Androgen receptor gene (XAR). There were 17/20 MZ pairs heterozygous at this locus and informative for analysis. Of these, 10/17 both had random X-inactivation, 5/17 showed identical X-inactivation patterns of non random inactivation and 2/17 (12%) showed discordant X-inactivation. There was no relationship between inactivation patterns and self-report chorionicity. We conclude that non-random X-inactivation does not appear to be a major contributor to intra-pair height discordance in female MZ twins.

Crystallization and preliminary X-ray diffraction studies of FHA domains of Dun1 and Rad53 protein kinases

Forkhead-associated (FHA) domains are modular protein–protein interaction domains of ~130 amino acids present in numerous signalling proteins. FHA-domain-dependent protein interactions are regulated by phosphorylation of target proteins and FHA domains may be multifunctional phosphopeptide-recognition modules. FHA domains of the budding yeast cell-cycle checkpoint protein kinases Dun1p and Rad53p have been crystallized. Crystals of the Dun1-FHA domain exhibit the symmetry of the space group P6122 or P6522, with unit-cell parameters a = b = 127.3, c = 386.3 Å; diffraction data have been collected to 3.1 Å resolution on a synchrotron source. Crystals of the N-terminal FHA domain (FHA1) of Rad53p diffract to 4.0 Å resolution on a laboratory X-ray source and have Laue-group symmetry 4/mmm, with unit-cell parameters a = b = 61.7, c = 104.3 Å.

Metformin and intervention in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is classically characterised by ovarian dysfunction (oligomenorrhoea, anovulation and infertility), androgen excess (hirsutism and acne), obesity, and morphological abnormalities of the ovaries (cystic enlargement and stromal expansion). More, recently, insulin resistance has been found to be common in PCOS, along with an increased prevalence of other features of the metabolic syndrome, namely glucose intolerance, type 2 diabetes mellitus, and hyperlipidaemia. Hyperinsulinaemia is likely to contribute to the disordered ovarian function and androgen excess of PCOS. Reducing insulin resistance by lifestyle modifications such as diet and exercise improves endocrine and menstrual function in PCOS. These lifestyle modifications are the best initial means of improving insulin resistance. Metformin, an oral hypoglycaemic agent that increases insulin sensitivity has been shown to reduce serum concentrations of insulin and androgens, to reduce hirsutism, and to improve ovulation rates. The effect of metformin alone on fertility rates is-unknown. Some studies suggest that metformin will reduce total body weight to a small extent, but with a predominant effect on visceral adipose reduction. The effects of metformin on lipid abnormalities, hypertension or premature vascular disease are unknown, but the relative safety, moderate cost, and efficacy in reducing insulin resistance suggest that metformin may prove to be of benefit in combating these components of the metabolic syndrome in PCOS. Further properly planned randomised controlled trials are required.

X-ray scattering studies of mixed langmuir monolayers and Langmuir-Blodgett films of a noncentrosymmetric porphyrin with cadmium arachidate

The structures of mixed Langmuir (floating) monolayers and Langmuir-Blodgett (LB) films of a phenanthroline-porphyrin with cadmium arachidate (PhenPor + CdAr) have been investigated by synchrotron X-ray grazing incidence diffraction (GIXD) and specular X-ray reflectivity (SXR). GIXD measurements of the floating monolayers showed only one peak, arising from the CdAr domains in the films, at a scattering angle of 21.5 degrees. This is consistent with a hexagonal structure (alpha = 4.77 Angstrom). The correlation length in these domains is 250 Angstrom. GMD measurements of the LB films, however, show two sets of diffraction features: one arises from CdAr domains with a rectangular in-plane structure (alpha = 7.44 Angstrom and b = 4.90 Angstrom) and a correlation length of 85 Angstrom; the other is from porphyrin domains with an oblique in-plane structure (alpha (p) 15.2 Angstrom, b(p) = 8.86 Angstrom, and gamma (p) = 80 degrees) and a correlation length of 105 Angstrom. These dimensions are consistent with the surface pressure-area isotherm measurements and indicate that the two components are immiscible. The thickness of the bilayer is 57 Angstrom, and there is no correlation between the bilayers. Introduction of a trigger compound does not alter the structure of the films but slightly increases the bilayer thickness. The SXR measurements of the floating monolayers also support the suggested immiscibility of the two components in the films.

Large-N solutions of the Heisenberg and Hubbard-Heisenberg models on the anisotropic triangular lattice: application to Cs2CuCl4 and to the layered organic superconductors kappa-(BEDT-TTF)(2)X (BEDT-TTF bis(ethylene-dithio)tetrathiafulvalene); X anion)

We solve the Sp(N) Heisenberg and SU(N) Hubbard-Heisenberg models on the anisotropic triangular lattice in the large-N limit. These two models may describe respectively the magnetic and electronic properties of the family of layered organic materials K-(BEDT-TTF)(2)X, The Heisenberg model is also relevant to the frustrated antiferromagnet, Cs2CuCl4. We find rich phase diagrams for each model. The Sp(N) :antiferromagnet is shown to have five different phases as a function of the size of the spin and the degree of anisotropy of the triangular lattice. The effects of fluctuations at finite N are also discussed. For parameters relevant to Cs2CuCl4 the ground state either exhibits incommensurate spin order, or is in a quantum disordered phase with deconfined spin-1/2 excitations and topological order. The SU(N) Hubbard-Heisenberg model exhibits an insulating dimer phase, an insulating box phase, a semi-metallic staggered flux phase (SFP), and a metallic uniform phase. The uniform and SFP phases exhibit a pseudogap, A metal-insulator transition occurs at intermediate values of the interaction strength.

Premenstrual syndrome: The condition, the therapy and the pharmacist.

The following aspects of premenstrual syndrome are discussed: classification, common symptoms, aetiology, pharmacological treatment, other therapies, role of the pharmacist. (non-author abstract)