bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarization control of gain of stacked InAs∕InP (100) quantum dots at 1.55μm: Interplay between ground and excited state transitions
Authors: Anantathanasarn S. , van Veldhoven P. J. , Eijkemans T. J. , de Vries T. , Smalbrugge E. , Geluk E. J. , Bente E. A. J. M. , Oei Y. S. , Smit M. K. , Nötzel R.
Published: March 2008

The linear polarization of the optical gain of closely stacked InAs∕InP (100) quantum dots (QDs) grown by metal-organic vapor-phase epitaxy with emission wavelength tuned into the 1.55μm region is controlled by the number of stacked QD layers and the injection current. Increasing the number of stacked QD layers to five rotates the linear polarization of the cleaved-side photoluminescence and QD ground state (GS) gain, determined from the amplified spontaneous emission (ASE) of a Fabry–Pérot ridge-waveguide laser, from transverse electric (TE) to transverse magnetic due to vertical electronic coupling. When the QD GS ASE and gain saturate with an increase of the injection current and the excited state ASE and gain become dominant, the linear polarization of ASE and gain changes back to TE. This limits the polarization insensitive operation of QD-based semiconductor optical amplifiers, however, opening routes to novel functionalities.
Stabilization of a β-hairpin in monomeric Alzheimer's amyloid-β peptide inhibits amyloid formation
Authors: Hoyer Wolfgang , Grönwall Caroline , Jonsson Andreas , Ståhl Stefan , Härd Torleif
Published: March 2008

According to the amyloid hypothesis, the pathogenesis of Alzheimer's disease is triggered by the oligomerization and aggregation of the amyloid-β (Aβ) peptide into protein plaques. Formation of the potentially toxic oligomeric and fibrillar Aβ assemblies is accompanied by a conformational change toward a high content of β-structure. Here, we report the solution structure of Aβ(1–40) in complex with the phage-display selected affibody protein Z
Aβ3
, a binding protein of nanomolar affinity. Bound Aβ(1–40) features a β-hairpin comprising residues 17–36, providing the first high-resolution structure of Aβ in β conformation. The positions of the secondary structure elements strongly resemble those observed for fibrillar Aβ. Z
Aβ3
stabilizes the β-sheet by extending it intermolecularly and by burying both of the mostly nonpolar faces of the Aβ hairpin within a large hydrophobic tunnel-like cavity. Consequently, Z
Aβ3
acts as a stoichiometric inhibitor of Aβ fibrillation. The selected Aβ conformation allows us to suggest a structural mechanism for amyloid formation based on soluble oligomeric hairpin intermediates.
CD11b expression distinguishes sequential stages of peritoneal B-1 development
Authors: Ghosn Eliver Eid Bou , Yang Yang , Tung James , Herzenberg Leonard A. , Herzenberg Leonore A.
Published: March 2008

Peritoneal cavity (PerC) B-1 cells have long been known to express CD11b, which is coexpressed with CD18 to form the Mac-1/CR3 complement receptor and adhesion molecule. However, although all PerC B-1 cells are commonly believed to express CD11b, we show here that nearly half of the cells in each of the PerC B-1 subsets (B-1a and B-1b) do not express this surface receptor. The CD11b+cells in each B-1 subset are larger and more granular and express higher levels of surface IgM than the CD11b−B-1 cells. In addition, the CD11b+B-1 cells initiate the formation of tightly associated doublets that are present at high frequency in adult PerC. Finally, and most importantly from a developmental standpoint, the CD11b+B-1 cells have a limited reconstitution capability: when sorted and transferred into congenic recipients, they reconstitute their own (CD11b+) B-1 subset but do not reconstitute the CD11b−B-1 subset. In contrast, CD11b−B-1 cells transferred under the same conditions efficiently replenish all components of the PerC B-1 population in appropriate proportions. During ontogeny, CD11b−B-1 cells appear before CD11b+B-1 cells. However, the clear phenotypic differences between the neonatal and adult CD11b B-1 subsets argue that although CD11b−B-1 give rise to CD11b+B-1 in both cases different forces may regulate this transition.
Human CMV infection of endothelial cells induces an angiogenic response through viral binding to EGF receptor and β
1
and β
3
integrins
Authors: Bentz Gretchen L. , Yurochko Andrew D.
Published: March 2008

Human cytomegalovirus (HCMV) infection is associated with atherosclerosis, transplant vascular sclerosis, and coronary restenosis. A common theme in these vascular diseases is an increased rate of angiogenesis. Angiogenesis is a complex biological process mediated by endothelial cell (EC) proliferation, migration, and morphogenesis. Although angiogenesis is a normal process in the host, its dysregulation, after viral infection or injury to the vessel wall, is associated with plaque development in atherosclerotic patients. We now document that HCMV infection results in increased EC proliferation, motility, and capillary tube formation. The observed HCMV-induced angiogenic response depended on viral binding to and signaling through the β
1
and β
3
integrins and the epidermal growth factor receptor, via their ability to activate the phosphatidylinositol 3-kinase and the mitogen-activated protein kinase signaling pathways. Because a proangiogenic response drives the neovascularization observed in atherosclerotic disease, our findings identify a possible mechanism for how HCMV infection contributes to vascular disease.
Pervasive impact of large-scale edge effects on a beetle community
Authors: Ewers Robert M. , Didham Raphael K.
Published: March 2008

Habitat edges are a ubiquitous feature of modern fragmented landscapes, but a tendency for researchers to restrict sampling designs to relatively small spatial scales means that edge effects are known to influence faunal communities over small spatial scales of only 20–250 m. However, we found striking changes in the abundance and community composition of 769 New Zealand beetle species (≈26,000 individuals) across very long edge gradients. We show that almost 90% of species respond significantly to habitat edges and that the abundances of 20% of common species were affected by edges at scales >250 m. Moreover, as many as one in eight common species had edge effects that appeared to penetrate as far as 1 km into habitat patches. Even 1 km inside forest, beetle communities differed in species richness, β-diversity (spatial turnover), and composition from the deep forest interior. Spatially explicit models of fragmented landscapes have shown that such large-scale edge effects can lead to an 80% reduction in the population size of interior forest species in even very large fragments. Moreover, such large-scale edge effects can drive species that inhabit central habitat core—which are among the most threatened species in fragmented landscapes—to local extinction from habitat fragments and protected areas. In a global analysis of protected areas, we show that kilometer-scale edge effects may compromise the ability of more than three-quarters of the world's forested reserves to conserve the community biostructures that are unique to forest interiors.
Regulation of innate immune responses by DAI (DLM-1/ZBP1) and other DNA-sensing molecules
Authors: Wang ZhiChao , Choi Myoung Kwon , Ban Tatsuma , Yanai Hideyuki , Negishi Hideo , Lu Yan , Tamura Tomohiko , Takaoka Akinori , Nishikura Kazuko , Taniguchi Tadatsugu
Published: March 2008

DNA, whether it is microbe-derived or host-derived, evokes immune responses when exposed to the cytosol of a cell. We previously reported that DNA-dependent activator of IFN regulatory factors (DAI), also referred to as DLM-1/ZBP1, functions as a DNA sensor that activates the innate immune system. In the present study, we examined the regulation of the complex DNA-sensing system by DAI and other molecules. We first show that DAI directly interacts with DNA
in vitro
and that it requires three DNA-binding domains for full activation
in vivo
. We also show that the artificially induced dimerization of DAI results in the DNA-independent activation of type I IFN genes, thereby providing a better understanding for the molecular basis of DAI activation. Furthermore, we provide evidence for the presence of additional DNA sensors, either positively or negatively regulating cytosolic DNA-mediated innate immune responses. These results
in toto
provide insights into the mechanism of DAI activation and reveal the complex regulatory mechanisms underlying DNA-mediated protective and pathologic immune responses.
From ‘Understanding the Brain by Creating the Brain’ towards manipulative neuroscience
Authors: Kawato Mitsuo
Published: March 2008

Ten years have passed since the Japanese ‘Century of the Brain’ was promoted, and its most notable objective, the unique ‘creating the brain’ approach, has led us to apply a humanoid robot as a neuroscience tool. Here, we aim to understand the brain to the extent that we can make humanoid robots solve tasks typically solved by the human brain by essentially the same principles. I postulate that this ‘Understanding the Brain by Creating the Brain’ approach is the only way to fully understand neural mechanisms in a rigorous sense. Several humanoid robots and their demonstrations are introduced. A theory of cerebellar internal models and a systems biology model of cerebellar synaptic plasticity is discussed. Both models are experimentally supported, but the latter is more easily verifiable while the former is still controversial. I argue that the major reason for this difference is that essential information can be experimentally manipulated in molecular and cellular neuroscience while it cannot be manipulated at the system level. I propose a new experimental paradigm, manipulative neuroscience, to overcome this difficulty and allow us to prove cause-and-effect relationships even at the system level.
Nitric Oxide Triggers Phosphatidic Acid Accumulation via Phospholipase D during Auxin-Induced Adventitious Root Formation in Cucumber
Authors: Lanteri María Luciana , Laxalt Ana María , Lamattina Lorenzo
Published: March 2008

Auxin and nitric oxide (NO) play fundamental roles throughout plant life. NO is a second messenger in auxin signal transduction leading to root developmental processes. The mechanisms triggered by auxin and NO that direct adventitious root (AR) formation are beginning to be unraveled. The goal of this work was to study phospholipid (PL) signaling during the auxin- and NO-induced AR formation in cucumber (Cucumis sativus) explants. Explants were labeled with 32P-inorganic phosphate and treated with the auxins indole-3-acetic acid or 1-naphthylacetic acid, or the NO donor S-nitroso N-acetyl penicillamine, in the presence or absence of the specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. PLs were separated by thin-layer chromatography and quantified. We report that the signaling PLs phosphatidic acid (PA), phosphatidylinositol phosphate, and phosphatidylinositol bisphosphate accumulated within 1 min after auxin or NO treatment. Both auxin and NO evoked similar and transient time course responses, since signaling PLs returned to control levels after 20 or 30 min of treatment. The results indicate that auxin relies on NO in inducing PA, phosphatidylinositol phosphate, and phosphatidylinositol bisphosphate accumulation. Furthermore, we demonstrate that auxin and NO trigger PA formation via phospholipase D (PLD) activity. Explants treated for 10 min with auxin or NO displayed a 200% increase in AR number compared with control explants. In addition, PLD activity was required for the auxin- and NO-induced AR formation. Finally, exogenously applied PA increased up to 300% the number of ARs. Altogether, our data support the idea that PLD-derived PA is an early signaling event during AR formation induced by auxin and NO in cucumber explants.
The Pea DELLA Proteins LA and CRY Are Important Regulators of Gibberellin Synthesis and Root Growth
Authors: Weston Diana E. , Elliott Robert C. , Lester Diane R. , Rameau Catherine , Reid James B. , Murfet Ian C. , Ross John J.
Published: March 2008

The theory that bioactive gibberellins (GAs) act as inhibitors of inhibitors of plant growth was based originally on the slender pea (Pisum sativum) mutant (genotype la cry-s), but the molecular nature of this mutant has remained obscure. Here we show that the genes LA and CRY encode DELLA proteins, previously characterized in other species (Arabidopsis [Arabidopsis thaliana] and several grasses) as repressors of growth, which are destabilized by GAs. Mutations la and cry-s encode nonfunctional proteins, accounting for the fact that la cry-s plants are extremely elongated, or slender. We use the la and cry-s mutations to show that in roots, DELLA proteins effectively promote the expression of GA synthesis genes, as well as inhibit elongation. We show also that one of the DELLA-regulated genes is a second member of the pea GA 3-oxidase family, and that this gene appears to play a major role in pea roots.
Disruption of the Arabidopsis Circadian Clock Is Responsible for Extensive Variation in the Cold-Responsive Transcriptome
Authors: Bieniawska Zuzanna , Espinoza Carmen , Schlereth Armin , Sulpice Ronan , Hincha Dirk K. , Hannah Matthew A.
Published: March 2008

In plants, low temperature causes massive transcriptional changes, many of which are presumed to be involved in the process of cold acclimation. Given the diversity of developmental and environmental factors between experiments, it is surprising that their influence on the identification of cold-responsive genes is largely unknown. A systematic investigation of genes responding to 1 d of cold treatment revealed that diurnal- and circadian-regulated genes are responsible for the majority of the substantial variation between experiments. This is contrary to the widespread assumption that these effects are eliminated using paired diurnal controls. To identify the molecular basis for this variation, we performed targeted expression analyses of diurnal and circadian time courses in Arabidopsis (Arabidopsis thaliana). We show that, after a short initial cold response, in diurnal conditions cold reduces the amplitude of cycles for clock components and dampens or disrupts the cycles of output genes, while in continuous light all cycles become arrhythmic. This means that genes identified as cold-responsive are dependent on the time of day the experiment was performed and that a control at normal temperature will not correct for this effect, as was postulated up to now. Time of day also affects the number and strength of expression changes for a large number of transcription factors, and this likely further contributes to experimental differences. This reveals that interactions between cold and diurnal regulation are major factors in shaping the cold-responsive transcriptome and thus will be an important consideration in future experiments to dissect transcriptional regulatory networks controlling cold acclimation. In addition, our data revealed differential effects of cold on circadian output genes and a unique regulation of an oscillator component, suggesting that cold treatment could also be an important tool to probe circadian and diurnal regulatory mechanisms.
ARABIDOPSIS TRITHORAX1 Dynamically RegulatesFLOWERING LOCUS CActivation via Histone 3 Lysine 4 Trimethylation
Authors: Pien Stéphane , Fleury Delphine , Mylne Joshua S. , Crevillen Pedro , Inzé Dirk , Avramova Zoya , Dean Caroline , Grossniklaus Ueli
Published: March 2008

Trithorax function is essential for epigenetic maintenance of gene expression in animals, but little is known about trithorax homologs in plants. ARABIDOPSIS TRITHORAX1 (ATX1) was shown to be required for the expression of homeotic genes involved in flower organogenesis. Here, we report a novel function of ATX1, namely, the epigenetic regulation of the floral repressor FLOWERING LOCUS C (FLC). Downregulation of FLC accelerates the transition from vegetative to reproductive development in Arabidopsis thaliana. In the atx1 mutant, FLC levels are reduced and the FLC chromatin is depleted of trimethylated, but not dimethylated, histone 3 lysine 4, suggesting a specific trimethylation function of ATX1. In addition, we found that ATX1 directly binds the active FLC locus before flowering and that this interaction is released upon the transition to flowering. This dynamic process stands in contrast with the stable maintenance of homeotic gene expression mediated by trithorax group proteins in animals but resembles the dynamics of plant Polycomb group function.
Demographics in an alpine reindeer herd: effects of density and winter weather
Authors: Helle Timo , Kojola Ilpo
Published: March 2008

We examined how population density, winter weather, snow conditions, and 2 large‐scale climatic indices (North Atlantic Oscillation, NAO, and Arctic Oscillation, AO) influenced demography (reproduction and mortality) in an alpine herd of semi‐domesticated reindeer Rangifer tarandus between 1959 and 2000 in Finnish Lapland. The herd lived on heavily grazed lichen pastures, with winter densities between 0.8 and 3.9 individuals km−2. Icing conditions occurred every 7th yr, on an average, and decreased reproductive rate (calves/females) by 49%. In general linear models icing remarkably increased the fit of snow models to reproductive rate. Incorporation of an interaction term between icing and the snow depth index provided better fit than a model without interaction. Delayed snowmelt decreased reproductive rate. For the day of snowmelt, however, the model without interaction was better than the interaction model. These 3 models provided the best fit to the data and accounted for 51–54% of the variation in reproductive rate. Winter mortality was related to density and large‐scale climatic indices, but not to local winter weather except a slight increase in mortality during an icing winter. The best model for winter mortality, including reindeer density and NAO, accounted for 26% of variation in mortality. Three factors may be involved explaining weak density dependence or the lack of such dependence; climate change scenarios that predict higher winter temperature, more frequent thawing‐freezing periods, and deeper snow would be expected to decrease reproductive rate and increase winter mortality of reindeer and thus to reduce profitability of reindeer husbandry. In contrast, early springs would be advantageous for reindeer in the short term.
A comparative analysis of the habitat of the extinct aurochs and other prehistoric mammals in Britain
Authors: Hall Stephen J. G.
Published: March 2008

The present study tests the hypothesis that the habitat of the globally extinct aurochs Bos primigenius was primarily riverine flat‐lands. Landscape features in Britain were analyzed for sites with Late Pleistocene and postglacial finds of aurochs (n=188), and, for comparison, wolf (101), brown bear (96), red deer (73), beaver (68), roe deer (46) and moose (23). Find sites were defined as Ordnance Survey 1 km map squares containing 1 or more finds. For each, spot height above sea level, heights of contour lines, flatness of terrain, total length of watercourses, and presence of woods, rock and water features were noted. Comparisons of find sites among species (Kruskal‐Wallis test) show significant differences that accord with knowledge of present‐day habitat preferences at the landscape level. Considering the species separately each find site was then compared with a randomly selected control map square within 10 km. Compared with their respective control squares, find sites of beaver have, today, a stronger association with presence of lakes; those of brown bear and wolf with presence of cliffs and rock outcrops; and those of aurochs with absence of woodland and with lower elevation and greater flatness. The concordance of these findings with the present‐day habitats of the extant species suggests valid inferences can be made about the habitat preference of the extinct aurochs. On this basis the aurochs appears, as hypothesized, to have selected low‐lying, flat ground, which (indicated by its present‐day use for purposes other than woodland) was relatively fertile.
Wogonin induces the granulocytic differentiation of human NB4 promyelocytic leukemia cells and up‐regulates phospholipid scramblase 1 gene expression
Authors: Zhang Kun , Guo Qing‐Long , You Qi‐Dong , Yang Yong , Zhang Hai‐Wei , Yang Li , Gu Hong‐Yan , Qi Qi , Tan Zi , Wang Xiaotang
Published: March 2008

Previous studies have firmly demonstrated that wogonin, a naturally occurring monoflavonoid extracted from the root of the Chinese herb medicine Scutellaria baicalensis, could effectively inhibit the proliferation of several cancer cell lines. However, little is known about the effect of wogonin on differentiation induction of leukemic cells. Here we investigate the potential role of wogonin in the proliferation and differentiation of NB4, a human promyelocytic leukemia cell line derived from a patient with acute promyelocytic leukemia. Our results indicated that wogonin significantly suppressed the proliferation and efficiently induced the differentiation of NB4 cells. NB4 cell growth was inhibited by 55–60% after treatment with 50 µM wogonin for a period of 5 days. The results of the nitroblue tetrazolium (NBT) reduction test (with 67.13% positive cells by 50 µM wogonin for 5 days), Giemsa staining (with 67.24% positive cells by 50 µM wogonin for 5 days), and the expression of mature‐related cell‐surface differentiation antigens CD11b and CD14 (with 70.94% CD11b+ and 5.82% CD14+ cells by 50 µM wogonin for 5 days) demonstrated an increase in the differentiation‐inducing action of wogonin on the NB4 cells, which was accompanied by an increase in mRNA and protein expression of phospholipids scramblase 1 (PLSCR1). Meanwhile, the level of phosphorylated PKCδ (Ser643) was dramatically increased in wogonin treated NB4 cells. Interestingly, wogonin treatment displayed little effect on the apoptosis of NB4 cells. Taken together, the results reported here demonstrated that wogonin could promote the granulocytic differentiation of NB4 cells by up‐regulating the expression of PLSCR1 gene. (Cancer Sci 2008; 99: 689–695)
A new transgenic mouse line to image chemically induced p53 activation in vivo
Authors: Briat Arnaud , Vassaux Georges
Published: March 2008

Monitoring p53 transcriptional activity to identify genotoxic damages induced by drugs has been proposed and validated in vitro. However, this methodology is by design limited to the cell line tested. In this study, we have fully validated a luciferase‐based p53‐reporter system in vitro and in vivo. We generated a mouse transgenic line to monitor non‐invasively p53 activation in response to chemically induced DNA damage. Doxorubicin was used as a drug of known toxicity to validate our model. Reporter gene expression was measured using bioluminescence imaging. In females, a weak p53 luciferase activity driven by a p53‐responsive promoter was detectable in the oral cavity region after doxorubicin treatment. In males, the signal increased in the lower abdominal region. Imaging of various organs revealed that the luciferase activity was mainly generated from the testes. Immunohistology demonstrated that the cells in the seminiferous tubules were damaged by the drug and confirmed that they were luciferase and p53 positive. Therefore, these transgenic mice could provide a powerful tool to predict, map and characterize at the organ and cellular levels the toxicity of compounds and help to develop new therapeutic agents in humans. (Cancer Sci 2008; 99: 683–688)
Influence of ABCB1 and ABCG2 polymorphisms on doxorubicin disposition in Asian breast cancer patients
Authors: Lal Suman , Wong Zee Wan , Sandanaraj Edwin , Xiang Xiaoqiang , Ang Peter Cher Siang , Lee Edmund J. D. , Chowbay Balram
Published: March 2008

The influence of three high frequency ABCB1 polymorphisms (c.1236C>T, c.2677G>A/T, and c.3435C>T) and the ABCG2 c.421C>A polymorphism on the disposition of doxorubicin in Asian breast cancer patients receiving adjuvant chemotherapy was investigated in the present study. The allelic frequency of the ABCB1 c.1236T, c.2677T, c.2677A, and c.3435T variants were 60%, 38%, 7%, and 22%, respectively, and the frequency of the ABCG2 c.421A allele was 23%. Pairwise analysis showed increased exposure levels to doxorubicin in patients harboring at least one ABCB1 c.1236T allele (P = 0.03). Patients homozygous for the CC‐GG‐CC genotype had significantly lower doxorubicin exposure levels compared to the patients who had CT‐GT‐CT (P = 0.02) and TT‐TT‐TT genotypes (P = 0.03). Significantly increased clearance of doxorubicin was also observed in patients harboring CC‐GG‐CC genotypes when compared to patients harboring the CT‐GT‐CT genotype (P = 0.01). Patients harboring the CC‐GG‐CC genotypes had significantly lower peak plasma concentrations of doxorubicinol compared to patients who had TT‐TT‐TT genotypes (P = 0.03). No significant influences on doxorubicin pharmacokinetic parameters were observed in relation to the ABCG2 c.421C>A polymorphism. In conclusion, the present exploratory study suggests that the three high frequency linked polymorphisms in the ABCB1 gene might be functionally important with regards to the altered pharmacokinetics of doxorubicin in Asian breast cancer patients, resulting in significantly increased exposure levels and reduced clearance. (Cancer Sci 2008; 99: 816–823)
Validation of the alcohol, smoking and substance involvement screening test (ASSIST)
Authors: Humeniuk Rachel , Ali Robert , Babor Thomas F. , Farrell Michael , Formigoni Maria L. , Jittiwutikarn Jaroon , De Lacerda Roseli B. , Ling Walter , Marsden John , Monteiro Maristela , Nhiwatiwa Sekai , Pal Hemraj , Poznyak Vladimir , Simon Sara
Published: March 2008

Aim  The concurrent, construct and discriminative validity of the World Health Organization's Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) were examined in a multi‐site international study.

Participants  One thousand and 47 participants, recruited from drug treatment (n = 350) and primary health care (PHC) settings (n = 697), were administered a battery of instruments.

Measurements  Measures included the ASSIST; the Addiction Severity Index‐Lite (ASI‐Lite); the Severity of Dependence Scale (SDS); the MINI International Neuropsychiatric Interview (MINI‐Plus); the Rating of Injection Site Condition (RISC); the Drug Abuse Screening Test (DAST); the Alcohol Use Disorders Identification Test (AUDIT); the Revised Fagerstrom Tolerance Questionnaire (RTQ); and the Maudsley Addiction Profile (MAP).

Findings  Concurrent validity was demonstrated by significant correlations between ASSIST scores and scores from the ASI‐Lite (r = 0.76–0.88), SDS (r = 0.59), AUDIT (r = 0.82) and RTQ (r = 0.78); and significantly greater ASSIST scores for those with MINI‐Plus diagnoses of abuse or dependence (P < 0.001). Construct validity was established by significant correlations between ASSIST scores and measures of risk factors for the development of drug and alcohol problems (r = 0.48–0.76). Discriminative validity was established by the capacity of the ASSIST to discriminate between substance use, abuse and dependence. Receiver operating characteristic (ROC) analysis was used to establish cut‐off scores with suitable specificities (50–96%) and sensitivities (54–97%) for most substances.

Conclusions  The findings demonstrated that the ASSIST is a valid screening test for identifying psychoactive substance use in individuals who use a number of substances and have varying degrees of substance use.
The immunomodulatory glycan LNFPIII initiates alternative activation of murine macrophages in vivo
Authors: Atochina Olga , Da’dara Akram A. , Walker Mirjam , Harn Donald A.
Published: March 2008

The early pathogen–macrophage interactions that help drive macrophage maturation towards classically or alternatively activated are largely unknown. To examine this question we utilized the immunomodulatory glycan Lacto‐N‐fucopentaose III (LNFPIII), which contains the Lewis X (LeX) trisaccharide, to activate murine peritoneal macrophages in vivo. Because LNFPIII is known to induce anti‐inflammatory responses, we asked if LNFPIII stimulation of macrophages in vivo initiates alternative activation events such as upregulation of Arginase 1, Ym1, FIZZ‐1, MGL‐1 or macrophage mannose receptor (MMR). Examination of peritoneal exudate cells from mice 20 hr post‐LNFPIII injection demonstrated increased Arginase 1 activity, at the mRNA and protein levels, coincident with undetectable inducible nitric oxide synthase expression or nitric oxide production. In addition to Arginase 1, Ym1 expression was also significantly upregulated at 20 and 48 hr after LNFPIII exposure in vivo. However, the expression of FIZZ‐1, MGL‐1, and MMR was not changed in these macrophages. In an attempt to determine activation requirements for functional activity, we adoptively transferred antigen‐pulsed, in vivo LNFPIII activated macrophages into naïve recipients and found that they were capable of triggering recipient T cells to secrete elevated levels of interleukin (IL)‐10 and IL‐13 compared to mice receiving control macrophages. Together, these data demonstrate that upregulation of expression of Arginase 1 and Ym1 occur very early in activation of macrophages, and can be independent of other alternatively activated (AA) macrophage markers. Importantly, these early events appear to be IL‐4/IL‐13‐independent in our model. In the future we hope to determine if upregulation of these initial AA maturational events is sufficient for these macrophages to exert immunoregulatory activity in vivo.
Shelf‐life extension of peaches through sodium alginate and methyl cellulose edible coatings
Authors: Maftoonazad Neda , Ramaswamy Hosahalli S. , Marcotte Michelle
Published: March 2008

The objective of this study was to determine the effect of sodium alginate and methyl cellulose coatings on the respiration rate, firmness, acidity, pH, total soluble solids and desiccation rate of peaches. Coated and uncoated control fruits were stored at 15 °C and 40% RH. Respiration rate, moisture loss, and changes in firmness, total titrable acidity, pH and total soluble solids of coated and control samples were determined at 3‐day intervals. The respiration rate, moisture loss and changes in quality parameters were much lower in coated peaches as compared with the control. While the maximum acceptable shelf‐life at 15 °C for control samples was 15 days, the coated samples maintained their acceptability up to 21 and 24 days, respectively, with sodium alginate and methyl cellulose coating. The reduced respiration and transpiration rates as a result of coatings were considered responsible for maintaining the quality and increasing the shelf‐life of peaches.
Effect of heating on physical properties and microstructure of black tiger shrimp (Penaeus monodon) and white shrimp (Penaeus vannamei) meats
Authors: Benjakul Soottawat , Visessanguan Wonnop , Kijroongrojana Kongkarn , Sriket Pisal
Published: March 2008

Effects of heating on cooking loss, texture, colour and microstructure of black tiger shrimp (Penaeus monodon) and white shrimp (Penaeus vannamei) meats from different parts were evaluated. Cooking loss increased sharply when the samples were heated for longer time, particularly more than 1 min (P < 0.05). Among all parts, tail part of both shrimps had the highest cooking loss. The shear force of all samples increased markedly when the samples were heated for longer time, especially more than 0.5 min (P < 0.05). Black tiger shrimp and white shrimp meats had the slight differences in shear force either before or after heating. L*, a* and b*‐values increased when heating time increased up to 1 min (P < 0.05). Similar microstructures between raw meats of black tiger shrimp and white shrimp were found. Cooked meats of both species had more compact fibre arrangement with the shrinkage of sarcomere, compared with raw samples. Generally, tail portion showed the denser structure than other parts.
Optimization of process parameters and mathematical modelling for dehulling of pigeonpea
Authors: Goyal Raj K. , Vishwakarma Rajesh K. , Wanjari Onkar D.
Published: March 2008

In this study, hulling efficiency and hulling losses were optimised for pigeonpea. Effects of hulling time, moisture content and cottonseed oil as pre‐milling agent were studied and optimised using response surface methodology. A quadratic model satisfactorily described the hulling efficiency with an R2 value of 0.93. It predicted maximum dehulling efficiency of 89.98% at 9.82% moisture content (wet basis), 12.05‐s time of hulling and 0.28% cottonseed oil treatment. Linear model developed for hulling loss showed significant effect of time of hulling whereas effect of oil treatment and moisture content were non‐significant. The model predicted hulling loss of 2.92% on optimum conditions. The results of the model were validated experimentally and were within the range.
Zero trans shortening using rice bran oil, palm oil and palm stearin through interesterification at pilot scale
Authors: Mayamol Ponmalakunnel Nichlavose , Balachandran Chandrasekharanpillai , Samuel Tomas , Sundaresan Andikannu , Arumughan Chami
Published: March 2008

Fat blends, formulated by mixing refined, bleached and deodorised (RBD) palm oil (PO) or RBD palm stearin (PS) with RBD rice bran oil (RBO) in various ratios were subjected to chemical interesterification (CIE) at pilot scale using sodium methoxide (NaOMe) as catalyst. The resultant interesterified fat was processed through a margarine crystalliser under optimised conditions. The blends before and after CIE were investigated for triacylglycerol (TAG) composition, solid fat content (SFC) and melting characteristics, polymorphic form, fatty acid composition (FAC), bioactive (tocols, sterols, oryzanol) constituents and trans fatty acids (TFA). CIE was found to be very effective in terms of rearrangement of fatty acids (FAs) among TAGs and consequent changes in the physical characteristics. The SFC of the interesterified PS/RBO blends decreased significantly (P ≤ 0.05) when compared with those of PO/RBO blends. The interesterified binary blends with 50–60% PS and 40–50% RBO, and 70–80% PO and 20–30% RBO had SFC curves in the range of all‐purpose type shortenings. CIE facilitated the formation of β′ polymorphic forms. FAC of shortenings prepared using the optimised blends contained 15–20% C18:2 polyunsaturated fatty acid (PUFA) and no TFA. Total tocol, sterol and oryzanol content of zero trans shortenings were 650–1145, 408–17 583 and 1309–14 430 ppm. CIE using NaOMe did not affect the bioactive constituents significantly (P ≤ 0.05).
Effects of gamma irradiation on quality of Pakistani blood red oranges (Citrus sinensis L. Osbeck)
Authors: Khalil Shahid Akbar , Hussain Shahid , Khan Maazullah , Khattak Amal Badshah
Published: March 2008

Effect of gamma irradiation and washing on physicochemical and sensory quality of blood red oranges was investigated. The citrus fruits were packed in cellophane bags and stored at room temperature for 42 days. Two gamma irradiation doses 0.25 and 0.5 kGy alone and in combination with washing were applied to the fruits. Weight loss decreased with gamma irradiation and increased with washing during storage. Acidity and ascorbic acid values were higher for the oranges irradiated at 0.5 kGy and minimum for the washed oranges. Generally, total soluble solids (TSS) increased during the storage period. However, washed samples had the highest concentration and 0.5 kGy‐irradiated samples had the lowest TSS at the end of the storage period. Sensory quality qualify by appearance, odour and taste are decreased during storage in both treatments. However, the fruits were still acceptable by the trained observers. It can be inferred from this study that irradiation at 0.5 kGy or in combination with washing is an effective post‐harvest technique in keeping the changes in physicochemical and sensory quality to a minimum level during storage.
Genetic diversity across the range of a temperate lizard
Authors: Howes Briar J. , Lougheed Stephen C.
Published: March 2008

Aim To examine range‐wide patterns of genetic diversity in association with range limits in a broadly distributed temperate lizard, and to identify the contributions of a series of environmental, geographical and historical variables to the observed patterns. Reduced genetic diversity may limit local adaptation in peripheral populations, thereby limiting their ability to adapt to marginal environmental conditions, possibly explaining the existence of temporally stable range limits.

Location Various sampling locales throughout eastern and central USA and southern Ontario, Canada.

Methods Genetic diversity of nuclear DNA microsatellites was estimated for each of 38 populations from across the range of eastern North America’s most broadly distributed lizard, the five‐lined skink,Plestiodon fasciatus(Linnaeus, 1758).

Results Local climatic conditions and an interaction between distance from range border and glaciation history best predicted a population’s present‐day genetic diversity. Overall, peripheral populations had reduced genetic diversity relative to that of central populations, but this difference was attributable to the reduced genetic diversity in peripheral populations to the north and west that are not bordered by any obvious physical boundaries.

Main conclusions Some, but not all, peripheral populations had reduced genetic diversity relative to that of more central populations, which probably arose through an interaction of ecological and historical factors. Peripheral populations that were bordered by an obvious boundary (e.g. an ocean) had higher diversity than peripheral populations that were not bordered by an obvious physical barrier to range expansion, suggesting that reduced intrapopulation genetic diversity is associated with range limits in the five‐lined skink.
Environmental parameters that determine species geographical range limits as a matter of time and space
Authors: Arntzen J. W. , Espregueira Themudo G.
Published: March 2008

Aim  To identify the ecological factors associated with the range borders of two amphibian species, to investigate geographical variation in environmental parameters that determine species range limits, and to develop a testable hypothesis on the species’ biogeographical history.

Location  Portugal and Spain.

Methods  We documented the distribution of two species of marbled newt (Triturus marmoratus and Triturus pygmaeus) from atlas data, survey data and six latitudinal transects. Countrywide ecogeographical models were constructed from presence‐only data and a suite of 19 environmental parameters. Local ecogeographical models were constructed along the contact zone.

Results  Triturus marmoratus and T. pygmaeus share a parapatric range border from coastal Portugal to central Spain. Ecogeographical models performed better in descriptive mode (for the country where they were developed) than in predictive mode (when extrapolated for the neighbouring country). This suggests the existence of spatial variation for parameters that determine the species range borders. Local models showed good performance in Spain and western Portugal. Parameters dominating the models were climatic (precipitation, temperature and solar radiation), geographical (altitude) and geophysical (soil permeability). Enclaves in the distribution of T. marmoratus/T. pygmaeus also corresponded with environmental parameters. Poor‐fitting local models were found in central Portugal, where the mutual range border of the two species coincides with the River Tejo.

Main conclusions  The fit and predictive performance of the ecogeographical models suggest that equilibrium conditions have been reached over most of the contact zone. Parameter selection, field observations and natural history knowledge led us to identify, in terms of reproductive strategy, a stable species with regular, but low annual recruitment (T. marmoratus) vs. an opportunistic species with fluctuating ‘all‐or‐nothing’ annual recruitment (T. pygmaeus). Ecological parapatry derives from the use of permanent ponds for breeding in T. marmoratus vs. ephemeral ponds used by T. pygmaeus. Enclaves in the distribution show that, historically, T. pygmaeus has been displacing T. marmoratus. In central Portugal, where the model fit is poor, the advance of T. pygmaeus is currently impeded by the River Tejo. We predict that once this barrier has been crossed, the contact zone will move c. 40 km to the north. As T. marmoratus and T. pygmaeus are hybridizing species, we predict the occasional presence of T. marmoratus genes in areas that have changed occupancy.
Dissimilatory iron reduction in Escherichia coli: identification of CymA of Shewanella oneidensis and NapC of E. coli as ferric reductases
Authors: Gescher Johannes S. , Cordova Carmen D. , Spormann Alfred M.
Published: March 2008

Over geological time scales, microbial reduction of chelated Fe(III) or Fe(III) minerals has profoundly affected today's composition of our bio‐ and geosphere. However, the electron transfer reactions that are specific and defining for dissimilatory iron(III)‐reducing (DIR) bacteria are not well understood. Using a synthetic biology approach involving the reconstruction of the putative electron transport chain of the DIR bacterium Shewanella oneidensis MR‐1 in Escherichia coli, we showed that expression of cymA was necessary and sufficient to convert E. coli into a DIR bacterium. In intact cells, the Fe(III)‐reducing activity was limited to Fe(III) NTA as electron acceptor. In vitro biochemical analysis indicated that CymA, which is a cytoplasmic membrane‐associated tetrahaem c‐type cytochrome, carries reductase activity towards Fe(III) NTA, Fe(III) citrate, as well as to AQDS, a humic acid analogue. The in vitro specific activities of Fe(III) citrate reductase and AQDS reductase of E. coli spheroplasts were 10× and 30× higher, respectively, relative to the specific rates observed in intact cells, suggesting that access of chelated and insoluble forms of Fe(III) and AQDS is restricted in whole cells. Interestingly, the E. coli CymA orthologue NapC also carried ferric reductase activity. Our data support the argument that the biochemical mechanism of Fe(III) reduction per se was not the key innovation leading to environmental relevant DIR bacteria. Rather, the evolution of an extension of the electron transfer pathway from the Fe(III) reductase CymA to the cell surface via a system of periplasmic and outer membrane cytochrome proteins enabled access to diffusion‐impaired electron acceptors.
Effect of cannabidiol on sepsis‐induced motility disturbances in mice: involvement of CB1receptors and fatty acid amide hydrolase
Authors: De Filippis D. , Iuvone T. , D'amico A. , Esposito G. , Steardo L. , Herman A. G. , Pelckmans P. A. , De Winter B. Y. , De Man J. G.
Published: March 2008

Abstract Sepsis is an inflammatory condition that is associated with reduced propulsive gastrointestinal motility (ileus). A therapeutic option to treat sepsis is to promote intestinal propulsion preventing bacterial stasis, overgrowth and translocation. Recent evidence suggests that anti‐oxidants improve sepsis‐induced ileus. Cannabidiol, a non‐psychotropic component ofCannabis sativa, exerts strong anti‐oxidant and anti‐inflammatory effects without binding to cannabinoid CB1or CB2receptors. Cannabidiol also regulates the activity of fatty acid amide hydrolase (FAAH) which is the main enzyme involved in endocannabinoid breakdown and which modulates gastrointestinal motility. Because of the therapeutic potential of cannabidiol in several pathologies, we investigated its effect on sepsis‐induced ileus and on cannabinoid receptor and FAAH expression in the mouse intestine. Sepsis was induced by treating mice with lipopolysaccharides for 18 h. Sepsis led to a decrease in gastric emptying and intestinal transit. Cannabidiol further reduced gastrointestinal motility in septic mice but did not affect gastrointestinal motility in control mice. A low concentration of the CB1antagonist AM251 did not affect gastrointestinal motility in control mice but reversed the effect of cannabidiol in septic mice. Sepsis was associated with a selective upregulation of intestinal CB1receptors without affecting CB2receptor expression and with increased FAAH expression. The increase in FAAH expression was completely reversed by cannabidiol but not affected by AM251. Our results show that sepsis leads to an imbalance of the endocannabinoid system in the mouse intestine. Despite its proven anti‐oxidant and anti‐inflammatory properties, cannabidiol may be of limited use for the treatment of sepsis‐induced ileus.
Effect of baclofen on oesophageal motility and transient lower oesophageal sphincter relaxations in GORD patients: a 48‐h manometric study
Authors: Grossi L. , Spezzaferro M. , Sacco L. F. , Marzio L.
Published: March 2008

Abstract  Little is known about prolonged effect of baclofen on oesophageal and lower oesophageal sphincter (LOS) motility. We aimed at investigating the oesophageal motility in gastro‐oesophageal reflux disease (GORD) patients 24 h before and after the administration of multiple doses of baclofen. Twenty‐one GORD patients underwent a 48‐h manometry recording the swallows, the oesophageal and the LOS motility. During the second 24‐h period, patients received baclofen 10 mg or placebo four times per day in a double‐blind randomized fashion. Baclofen increased the LOS basal tone in comparison with baseline (P = 0.02), with a concomitant reduction in the number of transient LOS relaxations (TLOSRs) (P = 0.01). Moreover, baclofen induced a decrease of the swallows (P = 0.02) and of primary oesophageal body waves (P = 0.04) with no changes in the amplitude. Multiple doses of baclofen determine a reduction in the number of TLOSRs and an increase in the LOS tone throughout the 24 h. The concomitant decreased number of swallows and of primary peristalsis could depend on the well‐known lower amount of reflux episodes induced by the drug. The potential therapeutic effect of baclofen could be expressed not only postprandially, but also in the fasting state when reflux episodes are present as well.
Dihydroxyacetone: a safe camouflaging option in vitiligo
Authors: Rajatanavin Natta , Suwanachote Suthida , Kulkollakarn Suthinee
Published: March 2008

Background  Most treatment protocols for vitiligo usually do not result in complete repigmentation. Therefore, cosmetically acceptable camouflage, low cost and easy to handle alternatives are warranted.

Objective  To evaluate the efficacy of low‐cost self‐tanner available in the Thai market in normal subjects with skin types III, IV, and V, and the efficacy for camouflage of 6% dihydroxyacetone (DHA) cream in the treatment of vitiligo on exposed areas of Asian skin.

Methods  The study was divided into two parts. Part 1 is a prospective study of 15 healthy volunteers using three different DHA creams which were available in the Thai market with concentrations of 3.5%, 4.2%, and 5%. Part 2 was a retrospective study of 20 patients suffering from vitiligo affecting the face and/or hands and feet who were treated with 6% DHA. The data were collected through direct examination, telephone interview, face‐to‐face interview, and photographs.

Results  In healthy volunteers, we found that color matching was achieved by using a higher concentration of DHA in darker‐skin subjects. Most of the vitiligo patients (88.9%) reported moderate to marked satisfaction with the cosmetic results of 6% DHA cream.

Conclusion  Dihydroxyacetone offers a safe and effective therapeutic option for recalcitrant vitiligo. Dark‐skin subjects need a higher concentration of DHA cream than lighter‐skin subjects.