Enhanced Pairing in the "Checkerboard" Hubbard Ladder

We study signatures of superconductivity in a 2--leg "checkerboard" Hubbard ladder model, defined as a one--dimensional (period 2) array of square plaquettes with an intra-plaquette hopping $t$ and inter-plaquette hopping $t'$, using the density matrix renormalization group method. The highest pairing scale (characterized by the spin gap or the pair binding energy, extrapolated to the thermodynamic limit) is found for doping levels close to half filling, $U\approx 6t$ and $t'/t \approx 0.6$. Other forms of modulated hopping parameters, with periods of either 1 or 3 lattice constants, are also found to enhance pairing relative to the uniform two--leg ladder, although to a lesser degree. A calculation of the phase stiffness of the ladder reveals that in the regime with the strongest pairing, the energy scale associated with phase ordering is comparable to the pairing scale.Comment: 9 pages, 9 figures; Journal reference adde

Lipids, lipoproteins, apolipoproteins, selected trace elements and minerals in the serum of children on valproic acid monotherapy

We evaluated the serum levels of lipids, lipoproteins, apolipoproteins, along with a number of minerals and trace elements such as Ca, Mg, Cu and Zn in a group of children after 6 months of valproic acid monotherapy. Thirty patients with seizures, mean age, 9.8 +/- 2.6 years and 79 healthy children (controls), mean age, 10.9 +/- 3.2 years. formed the two styd groups. The patient group was treated with valproic acid (27.9 +/- 14.8 mg/kg/24 hr). Patients underwent clinical and laboratory evaluations including liver function tests. NH3, lipid, mineral and selected trace element levels before and after six months on valproic acid treatment, whereas controls only one evaluation. Liver function data and NH3 levels were found to be elevated in the group of patients. whereas albumin level was reduced. Triglycerides, total cholesterol, HDL-C, apolipoprotein (ApoA)-1, Apo B and Ca concentrations were found relative to control values. LDL-C, VLDL-C, Mg, Cu, Zn, were measured significantly altered (P < 0.0001) compared to controls. The ratios ApoA-1/ApoB, HDL-C/ApoA-1, LDL-C/Apo B, which were closely related to the size of LDL particles, where correlated with Zn/Cu (P < 0.001). Serum lipid profile, especially LDL size, indirectly evaluated for the first time and metal levels were found to be significantly changed, after six months on valproic acid monotherapy, suggesting a possible risk of developing coronary heart disease. Since valproic acid is a long-term treatment. it could be recommended that the incorporation of measurements of lipids, lipoproteins, apolipoproteins and trace elements in the “follow up” laboratory testing could be a preventive measure

Thermodynamic transitions on metabolism and proliferation of glucocorticoid-treated acute leukemia cells

<p>Glucocorticoids play an essential part in anti-leukemic therapies. Resistance is considered crucial for disease prognosis. Glucocorticoids influence the metabolic properties of the cell and consequently the leukemic cells. We have previously outlined the differences that emerge from glucocorticoid treatment used in various concentrations, and lower concentrations manifested a mitogenic effect. A critical established glucocorticoid action is the apoptotic effect they exert on leukemic cells. However, little is known about the molecular response of malignant cells following glucocorticoid exposure. Even less is known about the cell proliferation dynamics governing leukemic cells under glucocorticoid influence. Growth and metabolic features are assumed to be of nonlinear nature. A model based prediction of glucocorticoid effects is derived by applying a non-linear fitting approximation to the measured parameters. Additionally, borrowing principles from the metabolic engineering and thermodynamics disciplines, we calculated the required energetics for cell proliferation under prednisolone treatment. Finally, we utilized a previously reported microarray dataset, to examine whether the predicted and measured parameters of the metabolism and proliferation under glucocorticoids are reflected in gene expression. Hence, making such an approach more pragmatic since those genes could shed light into the mechanisms of glucocorticoid-induced apoptotic resistance action, and subsequently identify novel targets for more efficient glucocorticoid treatments. We have eventually attempted to answer the basic question of what the thermodynamic mechanisms in the transition of the cell population from one state to the next are.</p

Oxidant/Antioxidant Status Is Impaired in Sepsis and Is Related to Anti-Apoptotic, Inflammatory, and Innate Immunity Alterations

Oxidative stress is considered pivotal in the pathophysiology of sepsis. Oxidants modulate heat shock proteins (Hsp), interleukins (IL), and cell death pathways, including apoptosis. This multicenter prospective observational study was designed to ascertain whether an oxidant/antioxidant imbalance is an independent sepsis discriminator and mortality predictor in intensive care unit (ICU) patients with sepsis (n = 145), compared to non-infectious critically ill patients (n = 112) and healthy individuals (n = 89). Serum total oxidative status (TOS) and total antioxidant capacity (TAC) were measured by photometric testing. IL-6, -8, -10, -27, Hsp72/90 (ELISA), and selected antioxidant biomolecules (Ζn, glutathione) were correlated with apoptotic mediators (caspase-3, capsase-9) and the central anti-apoptotic survivin protein (ELISA, real-time PCR). A wide scattering of TOS, TAC, and TOS/TAC in all three groups was demonstrated. Septic patients had an elevated TOS/TAC, compared to non-infectious critically ill patients and healthy individuals (p = 0.001). TOS/TAC was associated with severity scores, procalcitonin, IL-6, -10, -27, IFN-γ, Hsp72, Hsp90, survivin protein, and survivin isoforms -2B, -ΔΕx3, -WT (p p TOS/TAC (0.96 (95% CI = 0.93–0.99)) was higher than AUCTAC (z = 20, p TOS (z = 3.1, p = 0.002) in distinguishing sepsis. TOS/TAC, TOS, survivin isoforms -WT and -2B, Hsp90, IL-6, survivin protein, and repressed TAC were strong predictors of mortality (p < 0.01). Oxidant/antioxidant status is impaired in septic compared to critically ill patients with trauma or surgery and is related to anti-apoptotic, inflammatory, and innate immunity alterations. The unpredicted TOS/TAC imbalance might be related to undefined phenotypes in patients and healthy individuals

Oxidant/Antioxidant Status Is Impaired in Sepsis and Is Related to Anti-Apoptotic, Inflammatory, and Innate Immunity Alterations

Oxidative stress is considered pivotal in the pathophysiology of sepsis. Oxidants modulate heat shock proteins (Hsp), interleukins (IL), and cell death pathways, including apoptosis. This multicenter prospective observational study was designed to ascertain whether an oxidant/antioxidant imbalance is an independent sepsis discriminator and mortality predictor in intensive care unit (ICU) patients with sepsis (n = 145), compared to non-infectious critically ill patients (n = 112) and healthy individuals (n = 89). Serum total oxidative status (TOS) and total antioxidant capacity (TAC) were measured by photometric testing. IL-6, -8, -10, -27, Hsp72/90 (ELISA), and selected antioxidant biomolecules (Zeta n, glutathione) were correlated with apoptotic mediators (caspase-3, capsase-9) and the central anti-apoptotic survivin protein (ELISA, real-time PCR). A wide scattering of TOS, TAC, and TOS/TAC in all three groups was demonstrated. Septic patients had an elevated TOS/TAC, compared to non-infectious critically ill patients and healthy individuals (p = 0.001). TOS/TAC was associated with severity scores, procalcitonin, IL-6, -10, -27, IFN-gamma, Hsp72, Hsp90, survivin protein, and survivin isoforms -2B, -Delta Epsilon x3, -WT (p &lt; 0.001). In a propensity probability (age-sex-adjusted) logistic regression model, only sepsis was independently associated with TOS/TAC (Exp(B) 25.4, p &lt; 0.001). The AUC(TOS/TAC) (0.96 (95% CI = 0.93-0.99)) was higher than AUC(TAC) (z = 20, p &lt; 0.001) or AUC(TOS) (z = 3.1, p = 0.002) in distinguishing sepsis. TOS/TAC, TOS, survivin isoforms -WT and -2B, Hsp90, IL-6, survivin protein, and repressed TAC were strong predictors of mortality (p &lt; 0.01). Oxidant/antioxidant status is impaired in septic compared to critically ill patients with trauma or surgery and is related to anti-apoptotic, inflammatory, and innate immunity alterations. The unpredicted TOS/TAC imbalance might be related to undefined phenotypes in patients and healthy individuals