bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell Wall-Bound Invertase Limits Sucrose Export and Is Involved in Symptom Development and Inhibition of Photosynthesis during Compatible Interaction between Tomato andXanthomonas campestrispvvesicatoria
Authors: Kocal Nurcan , Sonnewald Uwe , Sonnewald Sophia 
Published: September 2008

AbstractCell wall-bound invertase (cw-Inv) plays an important role in carbohydrate partitioning and regulation of sink-source interaction. There is increasing evidence that pathogens interfere with sink-source interaction, and induction of cw-Inv activity has frequently been shown in response to pathogen infection. To investigate the role of cw-Inv, transgenic tomato (Solanum lycopersicum) plants silenced for the major leaf cw-Inv isoforms were generated and analyzed during normal growth and during the compatible interaction with Xanthomonas campestris pv vesicatoria. Under normal growth conditions, activities of sucrolytic enzymes as well as photosynthesis and respiration were unaltered in the transgenic plants compared with wild-type plants. However, starch levels of source leaves were strongly reduced, which was most likely caused by an enhanced sucrose exudation rate. Following X. campestris pv vesicatoria infection, cw-Inv-silenced plants showed an increased sucrose to hexose ratio in the apoplast of leaves. Symptom development, inhibition of photosynthesis, and expression of photosynthetic genes were clearly delayed in transgenic plants compared with wild-type plants. In addition, induction of senescence-associated and pathogenesis-related genes observed in infected wild-type plants was abolished in cw-Inv-silenced tomato lines. These changes were not associated with decreased bacterial growth. In conclusion, cw-Inv restricts carbon export from source leaves and regulates the sucrose to hexose ratio in the apoplast. Furthermore, an increased apoplastic hexose to sucrose ratio can be linked to inhibition of photosynthesis and induction of pathogenesis-related gene expression but does not significantly influence bacterial growth. Indirectly, bacteria may benefit from low invertase activity, since the longevity of host cells is raised and basal defense might be dampened.
Evidence for two transferrin loci in the Salmo trutta genome
Authors: Rozman T. , Dovc P. , Marić S. , Kokalj‐Vokač N. , Erjavec‐Škerget A. , Rab P. , Snoj A. 
Published: September 2008

SummaryTo determine the organization of transferrin (TF) locus in the Salmo trutta genome, partial DNA and cDNA sequencing, fluorescent in situ hybridization (FISH) and Salmo salar BAC analysis were performed. TF expression levels and copy number prediction were assessed using real‐time PCR. In addition to two previously reported DNA TF variant sequences of S. trutta and Salmo marmoratus (TF1), two novel variant sequences (TF2) were revealed in both species. Variant‐specific sequence tags, characterizing two variants for each TF type (TF1 and TF2), were identified in genomic clones from each of the F1 hybrids between S. trutta and S. marmoratus. These clearly documented double heterozygote status at the TF loci. The real‐time PCR data showed that each of the two TF types (TF1 and TF2) existed in one copy only and that the transcription of TF2 was considerably lower compared with TF1. Using FISH, hybridization signals were observed on two medium‐sized acrocentric chromosomes of S. trutta karyotype. A TF type‐specific PCR followed by a restriction analysis revealed the presence of two TF loci in the majority of analysed BAC clones. It was concluded that the TF gene is duplicated in the genome of S. trutta, and that the two TF loci are located adjacent to one another on the same chromosome. The differing transcription levels of TF1 and TF2 appear to depend on the corresponding promoter activity, which at least for TF2 seems to vary between different Salmo congeners.
A potential role of connexin 43 in epidermal growth factor‐induced proliferation of mouse embryonic stem cells: Involvement of Ca2+/PKC, p44/42 and p38 MAPKs pathways
Authors: Park J. H. , Lee M. Y. , Heo J. S. , Han H. J. 
Published: September 2008

Abstract.  Objectives: The gap junction protein, connexin (Cx), plays an important role in maintaining cellular homeostasis and cell proliferation by allowing communication between adjacent cells. Therefore, this study has examined the effect of epidermal growth factor (EGF) on Cx43 and its relationship to proliferation of mouse embryonic stem cells. Materials and methods: Expressions of Cx43, mitogen‐activated protein kinases (MAPKs) and cell cycle regulatory proteins were assessed by Western blot analysis. Cell proliferation was assayed with [3H]thymidine incorporation. Intercellular communication level was measured by a scrape loading/dye transfer method. Results: The results showed that EGF increased the level of Cx43 phosphorylation in a time‐ (≥5 min) and dose‐ (≥10 ng/mL) dependent manner. Indeed, EGF‐induced increase in phospho‐Cx43 level was significantly blocked by either AG 1478 or herbimycin A (tyrosine kinase inhibitors). EGF increased Ca2+ influx and protein kinase C (PKC) translocation from the cytosolic compartment to the membrane compartment. Moreover, pre‐treatment with BAPTA‐AM (an intracellular Ca2+ chelator), EGTA (an extracellular Ca2+ chelator), bisindolylmaleimide I or staurosporine (PKC inhibitors) inhibited the EGF‐induced phosphorylation of Cx43. EGF induced phosphorylation of p38 and p44/42 MAPKs, and this was blocked by SB 203580 (a p38 MAPK inhibitor) and PD 98059 (a p44/42 MAPK inhibitor), respectively. EGF or 18α‐glycyrrhetinic acid (GA; a gap junction inhibitor) increased expression levels of the protooncogenes (c‐fos, c‐jun and c‐myc), cell cycle regulatory proteins [cyclin D1, cyclin E, cyclin‐dependent kinase 2 (CDK2), CDK4 and p‐Rb], [3H]thymidine incorporation and cell number, but decreased expression levels of the p21WAF1/Cip1 and p27Kip1, CDK inhibitory proteins. Transfection of Cx43 siRNA also increased the level of [3H]thymidine incorporation and cell number. EGF, 18α‐GA or transfection of Cx43 siRNA increased 2‐DG uptake and GLUT‐1 protein expression. Conclusions: EGF‐induced phosphorylation of Cx43, which was mediated by the Ca2+/PKC, p44/42 and p38 MAPKs pathways, partially contributed to regulation of mouse embryonic stem cell proliferation.
Sleep disruption and domestic violence: exploring the interconnections between mothers and children
Authors: Humphreys Cathy , Lowe Pam , Williams Simon 
Published: September 2008

ABSTRACTThis paper argues that sleep disruption is both a strategy and an effect of violence and abuse which profoundly affects the lives of women and children. This paper traces the interconnections between the patterns of sleeping (not sleeping) for women and children living with and recovering from the effects of violence and abuse. It highlights the threat to the emotional and physical well‐being of children and women and provides a non‐pathologizing route into an exploration of one of the symptoms of trauma. It is based on a pilot study which interviewed 17 women, 14 of whom were mothers to 28 children. Mothers reported that many of their children experienced nightmares, bed‐wetting, night panics and disrupted sleep patterns. Recovery of the ability to sleep was often slow and uneven with interactive effects between women and children slowing progress.
Trends in water quality and discharge confound long‐term warming effects on river macroinvertebrates
Authors: DURANCE ISABELLE , ORMEROD S. J. 
Published: September 2008

Summary1. Climate‐change effects on rivers and streams might interact with other pressures, such as pollution, but long‐term investigations are scarce. We assessed trends among macroinvertebrates in 50 southern English streams in relation to temperature, discharge and water quality over 18 years (1989–2007).2. Long‐term records, coupled with estimates from inter‐site calibrations of 3–4 years, showed that mean stream temperatures in the study area had increased by 2.1–2.9 °C in winter and 1.1–1.5 °C in summer over the 26 year period from 1980 to 2006, with trends in winter strongest.3. While invertebrate assemblages in surface‐fed streams were constant, those in chalk‐streams changed significantly during 1989–2007. Invertebrate trends correlated significantly with temperature, but effects were spurious because (i) assemblages gained taxa typical of faster flow or well‐oxygenated conditions, contrary to expectations from warming; (ii) more invertebrate families increased in abundance than declined and (iii) concomitant changes in water quality (e.g. declining orthophosphate, ammonia and biochemical oxygen demand), or at some sites changes in discharge, explained more variation in invertebrate abundance and composition than did temperature.4. These patterns were reconfirmed in both group‐ and site‐specific analyses.5. We conclude that recent winter‐biased warming in southern English chalk‐streams has been insufficient to affect invertebrates negatively over a period of improving water quality. This implies that positive management can minimize some climate‐change impacts on stream ecosystems. Chalk‐stream invertebrates are sensitive, nevertheless, to variations in discharge, and detectable changes could occur if climate change alters flow pattern.6. Because climatic trends now characterize many inter‐annual time‐series, we caution other investigators to examine whether putative effects on ecological systems are real or linked spuriously to other causes of change.
Regulation of macrophage nitric oxide production by the protein tyrosine phosphatase Src homology 2 domain phosphotyrosine phosphatase 1 (SHP‐1)
Authors: Blanchette Julie , Abu‐Dayyeh Issa , Hassani Kasra , Whitcombe Lorie , Olivier Martin 
Published: September 2008

SummaryNitric oxide (NO) is a potent molecule involved in the cytotoxic effects mediated by macrophages (MØ) against microorganisms. We previously reported that Src homology 2 domain phosphotyrosine phosphatase 1 (SHP‐1)‐deficient cells generate a greater amount of NO than wild‐type cells in response to interferon‐γ (IFN‐γ). We also reported that theLeishmania‐induced MØ SHP‐1 activity is needed for the survival of the parasite within phagocytes through the attenuation of NO‐dependent and NO‐independent mechanisms. In the present study, we investigated the role of SHP‐1 in regulating key signalling molecules important in MØ NO generation. Janus tyrosine kinase 2 (JAK2), mitogen‐activated extracellular signal‐regulated protein kinase kinase (MEK), extracellular signal‐regulated kinases 1 and 2 (Erk1/Erk2) mitogen‐activated protein kinases, p38 and stress‐activated mitogen‐activated protein kinases/c‐Jun NH2‐terminal kinase (SAPK/JNK) were examined in immortalized bone marrow‐derived MØ (BMDM) from both SHP‐1‐deficient motheaten mice (me‐3) and their respective littermates (LM‐1). The results indicated that Erk1/Erk2 and SAPK/JNK are the main kinases regulated by SHP‐1 because the absence of SHP‐1 caused an increase in their phosphorylation. Moreover, only Apigenin, the specific inhibitor of Erk1/Erk2, was able to block IFN‐γ‐induced inducible nitric oxide synthase (iNOS) transcription and translation in me‐3 cells. Transcription factor analyses revealed that in the absence of SHP‐1, activator protein‐1 (AP‐1) was activated. The activation of AP‐1, and not nuclear factor‐κB (NF‐κB) or signal transducer and activator of transcription‐1α (STAT‐1α), may explain the enhanced NO generation in SHP‐1‐deficent cells. These observations emphasize the involvement of the MAPKs Erk1/Erk2 and SAPK/JNK in NO generation via AP‐1 activation. Collectively, our findings suggest that SHP‐1 plays a pivotal role in the negative regulation of signalling events leading to iNOS expression and NO generation. Furthermore, our observations underline the importance of SHP‐1‐mediated negative regulation in maintaining NO homeostasis and thus preventing the abnormal generation of NO that can be detrimental to the host.
Effect of canal preparation and residual root filling material on root impedance
Authors: Al‐bulushi A. , Levinkind M. , Flanagan M. , Ng Y.‐L. , Gulabivala K 
Published: September 2008

AbstractAim  To investigate the effect of root canal preparation and residual root filling material on the impedance characteristics of extracted human roots.Methodology  Thirty extracted, human single‐rooted teeth were mounted in a custom‐made apparatus that allowed strict temperature control. Impedance measurements of the roots were made with a file acting as the internal electrode, using a frequency response analyser. The measurements were made under three canal conditions: (i) before chemo‐mechanical preparation; (ii) after chemo‐mechanical preparation; (iii) after root filling removal to re‐establish patency (following placement of root filling). The measurements were taken at 0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 mm coronal to the apical terminus and also at 0.5 and 1 mm past the apical terminus. Impedance values were viewed using Nyquist plots and comparisons made within each tooth, between measurement points along the length of the canal, as well as under the different canal conditions. Equivalent circuits were modelled for different test conditions.Results  The impedance decreased from the coronal to the apical levels in all canal conditions in a characteristic way, with an exaggerated drop at the apical terminus. Impedance decreased after chemo‐mechanical preparation, but gave higher values compared with before or after instrumentation, once canal filling had been removed. Equivalent circuits remained consistent at the tested positions within the canal, regardless of canal condition, but the circuit component values changed with the impedance.Conclusions  Impedance was influenced by corono‐apical position, chemo‐mechanical preparation and residual root canal filling material.
Ultrafiltration‐modified chicken egg white lysozyme and its antibacterial action
Authors: Lesnierowski Grzegorz , Kijowski Jacek , Cegielska‐Radziejewska Renata 
Published: September 2008

SummaryThe aim of the study was to produce a lysozyme preparation with an increased content of enzyme polymeric forms using the ultrafiltration (UF) technique. The effect of selected parameters of the membrane process on the extent of enzyme modification was examined. The study showed that the membrane technique, developed for the production of lysozyme monomer, could also be used in the direct production of a preparation containing enzyme polymers. Under optimal conditions of the modification procedure, the obtained preparation contained 53.3% of lysozyme polymeric forms. The effectiveness of the antibacterial action of UF‐modified lysozyme against selected strains of bacteria was determined. Its bacteriostatic activity depended on the applied modification conditions. Among lysozyme preparations modified by UF, the highest bacteriostatic activity against selected strains of bacteria was recorded in the preparation containing 53.3% polymeric forms. The modification procedure facilitates the extension of the antibacterial spectrum of lysozyme against Gram‐negative bacteria (Pseudomonas fluorescens).
Effects of pulsed electric fields on bioactive components, colour and flavour of green tea infusions
Authors: Zhao Wei , Yang Ruijin , Wang Mo , Lu Rongrong 
Published: September 2008

SummaryGreen tea is an unfermented tea containing a higher quantity of bioactive components. In this paper, the effects of pulsed electric field (PEF) treatments on the bioactive components (polyphenols, catechins and free amino acids), colour and flavour of green tea infusions were studied. PEF as a promising non‐thermal sterilisation technology could efficiently retain polyphenols, catechins and original colour of green tea infusions with electric field strength from 20 to 40 kV cm−1 for 200 μs. PEF treatments caused a significant increase in the total free amino acids of green tea infusions. The total free amino acids increased by 7.5% after PEF treatment at 40 kV cm−1. The increase in total amino acids induced by PEF treatment, especially to theanine, is beneficial for the quality of commercial ready‐to‐drink green tea infusion products. There was no significant effect of PEF treatment at 20 or 30 kV cm−1 on flavour compounds of green tea infusions. However, PEF treatment caused losses of volatiles in green tea infusions to different extents when PEF dosage was higher than a critical level. The total concentration of volatiles lost was approximately 10% after PEF treatment at 40 kV cm−1 for 200 μs.
Antimicrobial activity of nisin incorporated in pectin and polylactic acid composite films against Listeria monocytogenes
Authors: Jin Tony , Liu LinShu , Zhang Howard , Hicks Kevin 
Published: September 2008

SummaryAn extruded composite food packaging film containing pectin, polylactic acids (PLAs) and nisin was developed to inhibit Listeria monocytogenes. The mechanical properties and surface structure of the film were also examined. Cells of L. monocytogenes were reduced by 2.1, 4.5 and 3.7 log units mL−1 by the pectin plus PLA (pectin/PLA) film containing nisin (1000 IU mL−1 of tested liquid) in Brain Heart Infusion (BHI) broth, liquid egg white and orange juice, respectively, after 48 h at 24 °C. Pectin played an important roll in embedding nisin into the film. The pectin/PLA film had a similar stiffness but lower tensile strength, elongation and fracture energy than the pure PLA film. These data suggested that nisin incorporated into the pectin/PLA film was an effective approach to reducing L. monocytogenes in a typical growth medium (e.g. BHI broth) as well as in foods (e.g. orange juice and liquid egg).
Reducing salt intake from meat products by combined use of lactate and diacetate salts without affecting microbial stability
Authors: Devlieghere Frank , Vermeiren Lieve , Bontenbal Erwin , Lamers Pieter‐Paul , Debevere Johan 
Published: September 2008

SummaryIn the framework of the trend towards lowering the salt content in meat products, an experiment was set up to determine combined effect of reducing the salt content with 20% or 40% and adding 2% or 3% Purasal® Opti.Form PD 4 (a mixture of potassium lactate and sodium diacetate) on the shelf‐life of a pre‐packaged cooked meat product. By means of a challenge test with a mixture of two Lactobacillus sakei strains and a Leuconostoc mesenteroides strain, it was observed that use of lactate/diacetate mixture enabled a 40% reduction of the salt content in this cooked meat product, whereas the microbial shelf‐life was significantly increased.
The performance of several oxygen scavengers in varying oxygen environments at refrigerated temperatures: implications for low‐oxygen modified atmosphere packaging of meat
Authors: Brandon Karen , Beggan Michelle , Allen Paul , Butler Francis 
Published: September 2008

SummaryThe oxygen scavenging capacity of four commercially available iron‐based oxygen scavengers was studied. Individual oxygen scavenger sachets were placed in pouches and filled with 1%, 2%, 6%, 12% or 22% oxygen, 40% carbon dioxide and balance nitrogen, and stored at 3 °C or 10 °C, with or without a drip pad infused with water and monitored over 24 h. The four scavengers all reduced oxygen from the packs at the oxygen concentrations and temperatures tested. However, for all of the conditions measured, the scavengers did not absorb their nominal capacity in the 24‐h period. In anoxic modified atmosphere packaging of beef steaks, it is essential to reduce residual oxygen levels to below 0.05% as quickly as possible to minimise the formation of metmyoglobin. While the scavengers tested were effective in removing oxygen, the rate of removal would appear not to be fast enough to create the anoxic conditions required to prevent metmyoglobin formation in beef steaks, particularly in those cuts, which are highly susceptible to metmyoglobin formation. Reproducibility was also a critical issue for the scavengers, particularly at low oxygen concentrations. None of the scavengers had a coefficient of variation of less than 20% at the low oxygen concentrations. Therefore, to obtain consistent results, it is recommended that multiple scavengers be used.
Biological activity and composition of extract from aerial root of Ficus microcarpa L. fil.
Authors: Ao Changwei , Deba Farah , Tako Masakuni , Tawata Shinkichi 
Published: September 2008

SummaryTotal phenolic content, antioxidant and antibacterial activities of Ficus microcarpa aerial roots were determined on methanol extract and its sub‐fractions (hexane, ethyl acetate, n‐butanol and water). The ethyl acetate fraction possessed the highest amount of phenolic compounds evaluated by Folin‐Ciocalteu reagent method. It also showed the highest antioxidant activity when tested the following methods: DPPH, ABTS+ radical‐scavenging, superoxide radical scavenging, reducing power and β‐carotene linoleic acid bleaching. On the other hand, high phenolics content extracts (ethyl acetate, methanol and n‐butanol) showed significantly higher inhibitory activity than low phenolics content extracts (water and hexane) against five tested Gram positive and Gram negative bacteria. Protocatechuic acid, catechol, p‐vinylguaiacol, syringol, p‐propylphenol, vanillin, p‐propylguaiacol, isovanillic acid, 4‐n‐Propylresorcinol, syringaldehyde and oleanolic acid contained in ethyl acetate fraction were identified by GC‐MS and HPLC based on their cochromatography with standard compounds. Protocatechuic acid, catechol and syringol exhibited nearly same antioxidant activity as did by positive control Trolox using the mentioned assays. Results here showed that the ethyl acetate fraction has strong antioxidant and antibacterial activities, which are correlated with its high level of phenolic compounds.
Optimising conditions for enzymatic extraction of edible gelatin from the cattle bones using response surface methodology
Authors: Hosseini‐Parvar Seyed H. , Keramat Javad , Kadivar Mahdi , Khanipour Elham , Motamedzadegan Ali 
Published: September 2008

SummaryThis work was initiated to optimise the factors affecting the enzymatic extraction of edible gelatin from the cattle bones using response surface methodology. A central composite rotatable design was used to evaluate the effects of the enzyme concentration, time of enzymatic treatment and extraction temperature on the yield of extraction, gel strength, apparent viscosity and absorption at 420 nm. The R2 values of regression models for all the response variables were higher than 0.9. Data analysis showed that all the process variables significantly (P < 0.01) affected the gel strength and apparent viscosity of extracted gelatin, whereas the effect of extraction temperature on both yield of extraction and absorption at 420 nm was not significant (P > 0.05). Graphical optimum conditions for the extraction yield, gel strength, apparent viscosity and absorption at 420 nm were determined as 6.1 ppm, 15.6 h, 70 °C; 9.1 ppm, 11.9 h, 70.3 °C; 7.86 ppm, 14.9 h, 77.5 °C and 2.8 ppm, 10 h, 60 °C, respectively. For all the response variables, the experimental values were very close to the predicted values and were not statistically different (P < 0.05).