Psychological and weight-related characteristics of patients with anorexia nervosa-restricting type who later develop bulimia nervosa

Background  

Over the last five to ten years there has been an increase in psychosomatic complaints (PSC) in Swedish children. The objective of the study was to examine the relation between PSC and sense of coherence (SOC).     

NK314, a topoisomerase II inhibitor that specifically targets the alpha isoform

Topoisomerase II (Top2) is a ubiquitous nuclear enzyme that relieves torsional stress in chromosomal DNA during various cellular processes. Agents that target Top2, involving etoposide, doxorubicin, and mitoxantrone, are among the most effective anticancer drugs used in the clinic. Mammalian cells possess two genetically distinct Top2 isoforms, both of which are the target of these agents. Top2alpha is essential for cell proliferation and is highly expressed in vigorously growing cells, whereas Top2beta is nonessential for growth and has recently been implicated in treatment-associated secondary malignancies, highlighting the validity of a Top2alpha-specific drug for future cancer treatment; however, no such agent has been hitherto reported. Here we show that NK314, a novel synthetic benzo[c]phenanthridine alkaloid, targets Top2alpha and not Top2beta in vivo. Unlike other Top2 inhibitors, NK314 induces Top2-DNA complexes and double-strand breaks (DSBs) in an alpha isoform-specific manner. Heterozygous disruption of the human TOP2alpha gene confers increased NK314 resistance, whereas TOP2beta homozygous knock-out cells display increased NK314 sensitivity, indicating that the alpha isoform is the cellular target. We further show that the absence of Top2beta does not alleviate NK314 hypersensitivity of cells deficient in non-homologous end-joining, a critical pathway for repairing Top2-mediated DSBs. Our results indicate that NK314 acts as a Top2alpha-specific poison in mammalian cells, with excellent potential as an efficacious and safe chemotherapeutic agent. We also suggest that a series of human knock-out cell lines are useful in assessing DNA damage and repair induced by potential topoisomerase-targeting agents.     

YIPF5 and YIF1A recycle between the ER and the Golgi apparatus and are involved in the maintenance of the Golgi structure

Yip1p/Yif1p family proteins are five-span transmembrane proteins localized in the Golgi apparatus and the ER. There are nine family members in humans, and YIPF5 and YIF1A are the human orthologs of budding yeast Yip1p and Yif1p, respectively. We raised antisera against YIPF5 and YIF1A and examined the localization of endogenous proteins in HeLa cells. Immunofluorescence, immunoelectron microscopy and subcellular fractionation analysis suggested that YIPF5 and YIF1A are not restricted to ER exit sites but also localized in the ER-Golgi intermediate compartment (ERGIC) and some in the cis-Golgi at steady state. Along with ERGIC53, YIPF5 and YIF1A remained in the cytoplasmic punctate structures after brefeldin A treatment, accumulated in the ERGIC and the cis-Golgi after treatment with AlF₄^- and accumulated in the ER when ER to Golgi transport was inhibited by Sar1(H79G). These results supported the localization of YIPF5 and YIF1A in the ERGIC and the cis-Golgi, and strongly suggested that they are recycling between the ER and the Golgi apparatus. Analysis by blue native PAGE and co-immunoprecipitation showed that YIPF5 and YIF1A form stable complexes of three different sizes. Interestingly, the knockdown of YIPF5 or YIF1A caused partial disassembly of the Golgi apparatus suggesting that YIPF5 and YIF1A are involved in the maintenance of the Golgi structure.     

Distribution of dissolved organic carbon and dissolved fulvic acid in mesotrophic Lake Biwa, Japan

The dissolved organic carbon (DOC) concentrations in mesotrophic Lake Biwa were determined by a total organic carbon (TOC) analyzer, and DOC molecular size distributions were determined by size exclusion chromatography (SEC) using a fluorescence detector at excitation/emission (Ex/Em) levels of 300/425 nm with the eluent at pH 9.7. The fluorescence wavelengths for detection were chosen from the result of excitation–emission matrix spectrometry (EEM) analysis for dissolved fulvic acid (DFA) extracted from Ado River (peak A, Ex/Em = 260–270/430–440 nm; peak B, Ex/Em = 300–310/420–430 nm). Ado River DFA was eluted with a retention time (RT) of 7.4–8.9 min and the apparent molecular weight was estimated at 22–87 kDa based on the elution curve for the spherical protein molecular weight standard. A DFA peak eluted at the same retention time as Ado River DFA also appeared in all the samples of Lake Biwa water. From the linear relationship between the peak areas with an RT of 7.4–8.9 min by SEC analysis and DOC values of DFA by TOC analysis of a series of DFA samples (r² = 0.9995), the concentrations of DFA in the lake water were roughly calculated. DFA was distributed within the range 0.25–0.43 mg C l⁻¹ and accounted for 15%–41% of DOC, with the highest ratios observed at a depth of 70 m in August and the lowest at 2.5 m in May.     

Effects of white light on beta-catenin signaling pathway in retinal pigment epithelium

This study investigated the effect of visible light exposure on retinal pigment epithelium (RPE). The activation of Wnt/β-catenin pathway was investigated by immunofluorescence and Western blot analysis using human retinal pigment epithelial (ARPE-19) cells, which demonstrated that the exposure of white light induced the activation of the Wnt/β-catenin pathway. Real time RT-PCR demonstrated that the mRNA of α-smooth muscle actin (α-SMA), and vimentin increased 2.5-4-fold and that of zona occludens 1 (ZO-1) decreased approximately 0.8-fold after white light exposure. The up-regulation of vimentin expression and the down-regulation of ZO-1 were evident by Western blot analysis and immunohistochemistry. Moreover, the ability of phagocytosis of ARPE-19 cells decreased 0.6-fold after light exposure. Together, white light exposure was supposed to induce the activation of Wnt/β-catenin pathway, the changes in the expression markers of epithelial and mesenchymal cells in RPE cells, and the concomitant impairment of the ability of phagocytosis.     

Analysis of Petal Anthocyanins to Investigate Flower Coloration of Zhongyuan (Chinese) and Daikon Island (Japanese) Tree Peony Cultivars

Pn, Pg; Pn, Pg > Cy ; Pn, Cy and Pn, Cy > Pg groups. Each group consequently specified significant features among CIELAB color notation and petal pigmentation, being adequate to characterize tree peony flowers as similar between Zhongyuan and Daikon Island cultivars, thus the cultivars of the two areas are suggested to be related to one another. Received 25 April 2000/ Accepted in revised form 21 December 2000     

Correlation between the leaf turnover rate and anti-herbivore defence strategy (balance between ant and non-ant defences) amongst ten species of <Emphasis Type="Italic">Macaranga</Emphasis> (Euphorbiaceae)

We measured variation in the intensities of ant and non-ant anti-herbivore defences amongst ten Macaranga species in Sarawak, Malaysia. Intensities of non-ant defences were estimated by measuring effects of fresh leaves (provided as food) of these Macaranga species on survival of common cutworm larvae [Spodoptera litura (Fabricius), Lepidoptera: Noctuidae]. Intensities of ant defences were estimated by measuring ant aggressiveness in the presence of artificial damage inflicted on plants. As part of our examination of non-ant defences, we measured leaf toughness (punch strength, by penetrometry), and the contents of total phenols and condensed tannin. We demonstrated interspecific variation in intensities of both ant and non-ant defences amongst ten Macaranga species and showed that the rank order of ant defence intensity was negatively correlated with the intensity of non-ant defence. We also found that the balance between ant and non-ant defence intensity was correlated with the rates of leaf turnover and shoot growth. Species investing more in ant defence tended to have higher leaf turnover rates. Macaranga species that occur preferentially in shadier microhabitats had lower leaf turnover rates, suggesting that non-ant defences are more cost-effective in more shade-tolerant species. Our results also suggest that the total intensity of non-ant defences is positively correlated with both leaf toughness and total phenol content.     

Decorin Core Protein (Decoron) Shape Complements Collagen Fibril Surface Structure and Mediates Its Binding

Decorin is the archetypal small leucine rich repeat proteoglycan of the vertebrate extracellular matrix (ECM). With its glycosaminoglycuronan chain, it is responsible for stabilizing inter-fibrillar organization. Type I collagen is the predominant member of the fibrillar collagen family, fulfilling both organizational and structural roles in animal ECMs. In this study, interactions between decoron (the decorin core protein) and binding sites in the d and e₁ bands of the type I collagen fibril were investigated through molecular modeling of their respective X-ray diffraction structures. Previously, it was proposed that a model-based, highly curved concave decoron interacts with a single collagen molecule, which would form extensive van der Waals contacts and give rise to strong non-specific binding. However, the large well-ordered aggregate that is the collagen fibril places significant restraints on modes of ligand binding and necessitates multi-collagen molecular contacts. We present here a relatively high-resolution model of the decoron-fibril collagen complex. We find that the respective crystal structures complement each other well, although it is the monomeric form of decoron that shows the most appropriate shape complementarity with the fibril surface and favorable calculated energies of interaction. One molecule of decoron interacts with four to six collagen molecules, and the binding specificity relies on a large number of hydrogen bonds and electrostatic interactions, primarily with the collagen motifs KXGDRGE and AKGDRGE (d and e₁ bands). This work helps us to understand collagen-decorin interactions and the molecular architecture of the fibrillar ECM in health and disease.