Systemic and local responses to repeated HL stress-induced retrograde signaling in Arabidopsis

Chloroplasts of leaves under high light stress initiate signals to the nuclei of both exposed and distal leaves in order to acclimate against the potential threat of oxidative damage: a process known as high light systemic acquired acclimation (HL SAA). This study explores the nature of HL SAA, synergistic interactions with other environmental stresses, and the impact of repeated HL stress on the acclimation response of exposed and distal leaves. This necessitated the development of novel experimental systems to investigate the initiation, perception, and response to HL SAA. These systems were used to investigate the HL SAA response by monitoring the induction of mRNA in distal leaves not exposed to the HL stress. Acclimation to HL is induced within minutes and the response is proportionally dependent on the quality and quantity of light. HL SAA treatments in conjunction with variations in temperature and humidity reveal HL SAA is influenced by fluctuations in humidity. These treatments also result in changes in auxin accumulation and auxin-responsive genes. A key question in retrograde signaling is the extent to which transient changes in light intensity result in a "memory" of the event leading to acclimation responses. Repeated exposure to short term HL resulted in acclimation of the exposed tissue and that of emerging and young leaves (but not older leaves) to HL and oxidative stress

Topolgical Charged Black Holes in Generalized Horava-Lifshitz Gravity

As a candidate of quantum gravity in ultrahigh energy, the $(3+1)$-dimensional Ho\v{r}ava-Lifshitz (HL) gravity with critical exponent $z\ne 1$, indicates anisotropy between time and space at short distance. In the paper, we investigate the most general $z=d$ Ho\v{r}ava-Lifshitz gravity in arbitrary spatial dimension $d$, with a generic dynamical Ricci flow parameter $\lambda$ and a detailed balance violation parameter $\epsilon$. In arbitrary dimensional generalized HL$_{d+1}$ gravity with $z\ge d$ at long distance, we study the topological neutral black hole solutions with general $\lambda$ in $z=d$ HL$_{d+1}$, as well as the topological charged black holes with $\lambda=1$ in $z=d$ HL$_{d+1}$. The HL gravity in the Lagrangian formulation is adopted, while in the Hamiltonian formulation, it reduces to Dirac$-$De Witt's canonical gravity with $\lambda=1$. In particular, the topological charged black holes in $z=5$ HL$_6$, $z=4$ HL$_5$, $z=3,4$ HL$_4$ and $z=2$ HL$_3$ with $\lambda=1$ are solved. Their asymptotical behaviors near the infinite boundary and near the horizon are explored respectively. We also study the behavior of the topological black holes in the $(d+1)$-dimensional HL gravity with $U(1)$ gauge field in the zero temperature limit and finite temperature limit, respectively. Thermodynamics of the topological charged black holes with $\lambda=1$, including temperature, entropy, heat capacity, and free energy are evaluated.Comment: 51 pages, published version. The theoretical framework of z=d HL gravity is set up, and higher curvature terms in spatial dimension become relevant at UV fixed point. Lovelock term, conformal term, new massive term, and Chern-Simons term with different critical exponent z are studie

GLUT1 expression patterns in different Hodgkin lymphoma subtypes and progressively transformed germinal centers

Background: Increased glycolytic activity is a hallmark of cancer, allowing staging and restaging with 18F-fluorodeoxyglucose-positron-emission-tomography (PET). Since interim-PET is an important prognostic tool in Hodgkin lymphoma (HL), the aim of this study was to investigate the expression of proteins involved in the regulation of glucose metabolism in the different HL subtypes and their impact on clinical outcome. Methods: Lymph node biopsies from 54 HL cases and reactive lymphoid tissue were stained for glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA) and lactate exporter proteins MCT1 and MCT4. In a second series, samples from additional 153 HL cases with available clinical data were stained for GLUT1 and LDHA. Results: Membrane bound GLUT1 expression was frequently observed in the tumor cells of HL (49% of all cases) but showed a broad variety between the different Hodgkin lymphoma subtypes: Nodular sclerosing HL subtype displayed a membrane bound GLUT1 expression in the Hodgkin-and Reed-Sternberg cells in 56% of the cases. However, membrane bound GLUT1 expression was more rarely observed in tumor cells of lymphocyte rich classical HL subtype (30%) or nodular lymphocyte predominant HL subtype (15%). Interestingly, in both of these lymphocyte rich HL subtypes as well as in progressively transformed germinal centers, reactive B cells displayed strong expression of GLUT1. LDHA, acting downstream of glycolysis, was also expressed in 44% of all cases. We evaluated the prognostic value of different GLUT1 and LDHA expression patterns; however, no significant differences in progression free or overall survival were found between patients exhibiting different GLUT1 or LDHA expression patterns. There was no correlation between GLUT1 expression in HRS cells and PET standard uptake values. Conclusions: In a large number of cases, HRS cells in classical HL express high levels of GLUT1 and LDHA indicating glycolytic activity in the tumor cells. Although interim-PET is an important prognostic tool, a predictive value of GLUT1 or LDHA staining of the primary diagnostic biopsy could not be demonstrated. However, we observed GLUT1 expression in progressively transformed germinal centers and hyperplastic follicles, explaining false positive results in PET. Therefore, PET findings suggestive of HL relapse should always be confirmed by histology

Ku70 Is Required for Late B Cell Development and Immunoglobulin Heavy Chain Class Switching

Immunoglobulin (Ig) heavy chain (HC) class switch recombination (CSR) is a late B cell process that involves intrachromosomal DNA rearrangement. Ku70 and Ku80 form a DNA end-binding complex required for DNA double strand break repair and V(D)J recombination. Ku70^(−/−) (K70T) mice, like recombination activating gene (RAG)-1– or RAG-2–deficient (R1T or R2T) mice, have impaired B and T cell development at an early progenitor stage, which is thought to result at least in part from defective V(D)J recombination (Gu, Y., K.J. Seidl, G.A. Rathbun, C. Zhu, J.P. Manis, N. van der Stoep, L. Davidson, H.L. Cheng, J.M. Sekiguchi, K. Frank, et al. 1997. Immunity. 7:653–665; Ouyang, H., A. Nussenzweig, A. Kurimasa, V.C. Soares, X. Li, C. Cordon-Cardo, W. Li, N. Cheong, M. Nussenzweig, G. Iliakis, et al. 1997. J. Exp. Med. 186:921–929). Therefore, to examine the potential role of Ku70 in CSR, we generated K70T mice that carry a germline Ig HC locus in which the JH region was replaced with a functionally rearranged VH(D)JH and Ig λ light chain transgene (referred to as K70T/HL mice). Previously, we have shown that B cells from R1T or R2T mice carrying these rearranged Ig genes (R1T/HL or R2T/HL mice) can undergo CSR to IgG isotypes (Lansford, R., J. Manis, E. Sonoda, K. Rajewsky, and F. Alt. 1998. Int. Immunol. 10:325–332). K70T/HL mice had significant numbers of peripheral surface IgM^+ B cells, which generated serum IgM levels similar to those of R2T/HL mice. However, in contrast to R2T/HL mice, K70T/HL mice had no detectable serum IgG isotypes. In vitro culture of K70T/HL B cells with agents that induce CSR in normal or R2T/HL B cells did lead to the induction of germline CH transcripts, indicating that initial signaling pathways for CSR were intact in K70T/HL cells. However, treatment with such agents did not lead to detectable CSR by K70T/HL B cells, and instead, led to cell death within 72 h. We conclude that Ku70 is required for the generation of B cells that have undergone Ig HC class switching. Potential roles for Ku70 in the CSR process are discusse

Another treatment option for relapsed or refractory chronic lymphocytic leukaemia.

We hereby report the clinical and biologic features of 33 of 4680 (0.7%) patients with chronic lymphocytic leukemia (CLL), managed at 10 Italian centers, who developed Hodgkin lymphoma (HL), a rare variant of Richter syndrome. The median age at CLL and at HL diagnosis were 61 years (range 41-80) and 70 years (range 46-82), respectively, with a median interval from CLL to the diagnosis of HL of 90 months (range 0-258). In 3 cases, CLL and HL were diagnosed simultaneously. Hl was characterized by advanced stage in 79% of cases, International Prognostic Score (IPS) ≥4 in 50%, extranodal involvement in 39%, B symptoms in 70%. Prior treatment for CLL had been received by 82% of patients and included fludarabine in 67%. Coexistence of CLL and HL was detected in the same bioptic tissue in 87% of cases. The most common administered treatment was the ABVD regimen given to 22 patients (66.6%). The complete response (CR) rate after ABVD was 68%, and was influenced by the IPS (P = .03) and interval from the last CLL treatment (P = .057). Survival from HL was also influenced by the IPS (P = .006) and time from the last CLL treatment (P = .047). The achievement of CR with ABVD was the only significant and independent factor predicting survival (P = .037). Taken together, our results show that the IPS and the interval from the prior CLL treatment influence the likelihood of achieving CR after ABVD, which is the most important factor predicting survival of patients with CLL developing HL

Structural studies on silver(I) complexes containing phenylcyanamido ligands and uranyl(VI) complexes with beta-ketophenolates : a dissertation presented in partial fulfilment for the degree of Master of Science in Chemistry at Massey University

This thesis is divided into two parts. In Section One studies on the interaction of phenylcyanamides with silver(I) are reported. Section Two describes the results of studies on the complexes formed from β-ketophenol ligands and the uranyl ion. Section One Chapter 1 is a brief overview of the use of phenylcyanamides in forming coordination complexes with transition metals. In Chapter 2 the preparation of a series of silver complexes of the general formula [Ag(Ph₃P)₃(pcyd)], where pcyd is a phenylcyanamido anion, is described. The crystal structures of [Ag(Ph₃P)₃(4-Brpcyd)] and [Ag(Ph₃P)₃(4-MeOpcyd)] have been determined, in which the silver atom occupies a distorted tetrahedral environment, and the latter complex has a very short terminal C-N bond within the 4-methoxyphenylcyanamido ligand. Chapter 3 provides a comparison of all those transition metal complexes of phenylcyanamides that have been structurally characterised. Section Two Chapter 4 is a brief overview of the use of β-diketonate ligands in forming dinuclear complexes, especially those in which the uranyl ion (UO₂²+) is present. In Chapter 5 the preparation of the mononuclear complexes [UO₂(HL¹)₂(MeOH)], (UO₂(HL²)₂(EtOH)], the heterobinuclear complexes [U0₂Mn(L¹)₂(EtOH)]·1.5H₂O, and [UO₂Mn(L²)₂(EtOH)]·2H₂₂O and the oxo-ligand adducts [UO₂(HL¹)₂(Ph₃AsO)]·2H₂O, [U0₂(HL²)₂(Ph₃PO)] and [UO₂(HL²)₂(Ph₃AsO)] (H₂L¹ = 1-(2-hydroxyphenyl)-3- butanedione and H₂L² = 1-(2-hydroxyphenyl)-3-phenyl-l,3-propanedione) is described. The complexes have been characterized by a variety of physicochemical techniques and the crystal structures of [UO₂(HL¹)₂(EtOH)] and [UO₂(HL²)₂(EtOH)]·EtOH determined. Both complexes contain seven coordinate uranium(VI) in a pentagonal bipyramidal geometry in which the two bidentate β-diketonato ligands and the ethanol ligand make up the equatorial pentagonal plane. For the complex [UO₂(HL¹)₂(EtOH)] the HL¹ ligands are in a trans arrangement with respect to one another, whereas for the [UO₂(HL²)₂(EtOH)]·EtOH complex the HL² ligands adopt a cis arrangement. However, in solution variable temperature ¹H NMR spectra indicate that the cis and trans isomers are in equilibrium for both complexes

Steady-state, effective-temperature dynamics in a glassy material

We present an STZ-based analysis of numerical simulations by Haxton and Liu (HL). The extensive HL data sharply test the basic assumptions of the STZ theory, especially the central role played by the effective disorder temperature as a dynamical state variable. We find that the theory survives these tests, and that the HL data provide important and interesting constraints on some of its specific ingredients. Our most surprising conclusion is that, when driven at various constant shear rates in the low-temperature glassy state, the HL system exhibits a classic glass transition, including super-Arrhenius behavior, as a function of the effective temperature.Comment: 9 pages, 6 figure