bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of nitrogen source on olives growing in soils with high boron content
Authors: Chatzissavvidis Christos A. , Therios Ioannis N. , Antonopoulou Chrysovalantou
Published: November 2007

A greenhouse experiment was conducted to study the effects of nitrogen (N) forms (NO3–, 2.6 mmol/L; NH4+, 2.6 mmol/L; NO3–, 1.0 mmol/L plus NH4+, 1.6 mmol/L) and boron (B) (0.025, 0.5 and 1.0 mmol/L) on the growth and mineral composition of olive plants (Olea europaea L.). One-year-old own-rooted plants of the olive cultivars Megaritiki, Chondrolia Chalkidikis, Koroneiki and Kalamon were grown in plastic bags containing inert sand–perlite medium (1 : 1) and were irrigated with a 50% modified Hoagland nutrient solution. The plants treated with NO3– and 1.0 mmol B/L presented higher leaf B than those treated with NH4+ and 1.0 mmol B/L, for all cultivars. The addition of ammonium form fertilisation caused a significant accumulation of B to root tissues when the latter consisted of 0.5 mmol/L. As B was increased in the NO3–-N treatments, the number of leaves and the root dry weight of cv. Megaritiki as well as the plant height of cvv. Koroneiki and Kalamon were reduced. The above results suggest that in olive, addition of NH4+ to high B soils may be more beneficial for growth of olives than addition of NO3–. In most cases N form did not affect total leaf and root N levels. Also, the NH4+-N treatments showed a decline in root phosphorus (P) and an increase in leaf potassium with increased B. The general trend was a decrease of P in leaves with increasing B.
Impact of interspecific competition on seed development and quality of five soybean cultivars
Authors: Millar Katherine , Gibson David J. , Young Bryan G. , Wood Andrew J.
Published: November 2007

Enhancing total yield and improving seed quality is a dynamic area of research. Both breeding and biotechnology have been successful in creating soybean cultivars with increased oil or protein content with much research directed at total yield. We conducted a 2-year field experiment to investigate the potential impact of interspecific competition on seed quality and seed development of five soybean cultivars (Forrest, Essex, Asgrow 4603, Asgrow 4403 and Asgrow 3903). Three levels of weed competition were established using different application rates of pre-emergence herbicides s-metolachlor and cloransulam. Several seed related parameters were measured and many showed similar trends of significance for cultivar and weed competition treatments across both years. Higher levels of weed competition resulted in soybean seeds containing higher protein content (increase between 0.7 and 1%). For protein in 2005, there was a significant interaction term for competition level and cultivar (F8,44 = 2.38, P < 0.05). Seed oil tended to decrease with higher levels of competition, but by less than 1% each year. Seed yield showed a significant decrease in response to competition in 2005 (F2,44 = 56.82, P < 0.0001), but not in 2004. Seed per plant decreased in response to competition both years (2004: F2,44 = 8.23, P < 0.05; 2005: F2,44 = 8.71, P < 0.05). Seed per plant was impacted both years by competition. The number of aborted pods per plant was greater for plants under low and medium competition; however, significance was seen only in 2004 (F2,44 = 3.33, P < 0.05) but the trend was evident in 2005. Seed quality changes are responsive to the presence of neighbouring plants even if their interference does not reduce total yield. Future studies should be designed to investigate how competition and interference alter soybean metabolism such that seed quality is maximised.
Genotypic variation in salinity tolerance of Distichlis spicata turf ecotypes
Authors: Marcum Kenneth B. , Yensen Nicholas P. , Leake John E.
Published: November 2007

Water quantity and quality issues are accelerating the search for alternative xeriphytic and halophytic turf species. Growth and physiological responses to salinity of eight Distichlis spicata (L.) Greene genotypes were observed to elucidate salinity tolerance mechanisms operating in the species. Accession 1043 was superior in salinity tolerance to other genotypes, as indicated by percentage canopy green leaf area, relative (to control) shoot growth, relative root growth, and rooting depth, when exposed to increasing salinity up to 1.0 mol/L NaCl. Salinity tolerance was associated with complete, though minimal, shoot osmotic adjustment, maintenance of low shoot saline ion levels, and high shoot K+/Na+ ratios, all of which were facilitated by high leaf salt gland ion excretion rates.
Sympatric speciation by allochrony in a seabird
Authors: Friesen V. L. , Smith A. L. , Gómez-Díaz E. , Bolton M. , Furness R. W. , González-Solís J. , Monteiro L. R.
Published: November 2007

The importance of sympatric speciation (the evolution of reproductive isolation between codistributed populations) in generating biodiversity is highly controversial. Whereas potential examples of sympatric speciation exist for plants, insects, and fishes, most theoretical models suggest that it requires conditions that are probably not common in nature, and only two possible cases have been described for tetrapods. One mechanism by which it could occur is through allochronic isolation—separation of populations by breeding time.Oceanodroma castro(the Madeiran or band-rumped storm-petrel) is a small seabird that nests on tropical and subtropical islands throughout the Atlantic and Pacific Oceans. In at least five archipelagos, different individuals breed on the same islands in different seasons. We compared variation in five microsatellite loci and the mitochondrial control region among 562O. castrofrom throughout the species' range. We found that sympatric seasonal populations differ genetically within all five archipelagos and have ceased to exchange genes in two. Population and gene trees all indicate that seasonal populations within four of the archipelagos are more closely related to each other than to populations from the same season from other archipelagos; divergence of the fifth sympatric pair is too ancient for reliable inference. Thus, seasonal populations appear to have arisen sympatrically at least four times. This is the first evidence for sympatric speciation by allochrony in a tetrapod, and adds to growing indications that population differentiation and speciation can occur without geographic barriers to gene flow.
Protein phosphatase 2A regulates life and death decisions via Akt in a context-dependent manner
Authors: Andrabi Shaida , Gjoerup Ole V. , Kean Jennifer A. , Roberts Thomas M. , Schaffhausen Brian
Published: November 2007

Here, we show how targeting protein phosphatase 2A (PP2A), a key regulator of cellular protein phosphorylation, can either induce or prevent apoptosis depending on what other signals the cell is receiving. The oncoprotein polyoma small T interacts with PP2A to regulate survival. In the presence of growth factors, small T induces apoptosis. Akt activity, which usually promotes survival, is required for this death response, because inhibitors of Akt or PI3 kinase protect cells from death. The activation of Akt under these conditions is partial, characterized by T308 phosphorylation but not S473 phosphorylation. In the absence of growth factors, small T protects from cell death. Here, small T uses PP2A to promote phosphorylation of Akt on both T308 and S473. This effect results in a different pattern of phosphorylation of Akt substrates and shifts Akt from a proapoptotic (presence of growth factors) to an antiapoptotic mode (absence of growth factors). An intriguing possibility is that Akt phosphorylation could be therapeutically disregulated to decrease the survival of cancer cells.
The protective effect of A20 on atherosclerosis in apolipoprotein E-deficient mice is associated with reduced expression of NF-κB target genes
Authors: Wolfrum Susanne , Teupser Daniel , Tan Marietta , Chen Kwan Y. , Breslow Jan L.
Published: November 2007

Up-regulation of inflammatory responses is considered a driving force of atherosclerotic lesion development. One key regulator of inflammation is the A20 (also called TNF-α-induced protein 3 or Tnfaip3) gene, which is responsible for NF-κB termination and maps to an atherosclerosis susceptibility locus revealed by quantitative trait locus-mapping studies at mouse proximal chromosome 10. In the current study, we examined the role of A20 in atherosclerotic lesion development. At the aortic root lesion size was found to be increased in C57BL/6 (BG) apolipoprotein E-deficient (ApoE
−/−
) mice haploinsufficient for A20, compared with B6 ApoE
−/−
controls that expressed A20 normally (60% in males and 23% in females;
P
< 0.001 and
P
< 0.05, respectively). In contrast, lesion size was found to be decreased in F
1
(B6×FVB/N) mice overexpressing A20 by virtue of containing an A20 BAC transgene compared with nontransgenic controls (30% in males,
P
< 0.001, and 17% in females,
P
= 0.02). The increase in lesions in the A20 haploinsufficient mice correlated with increased expression of proatherosclerotic NF-κB target genes, such as vascular cell adhesion molecule 1, intercellular adhesion molecule 1, and macrophage-colony-stimulating factor, and elevated plasma levels of NF-κB-driven cytokines. These findings suggest that A20 diminishes atherosclerosis by decreasing NF-κB activity, thereby modulating the proinflammatory state associated with lesion development.
Role of uncoupling protein UCP2 in cell-mediated immunity: How macrophage-mediated insulitis is accelerated in a model of autoimmune diabetes
Authors: Emre Yalin , Hurtaud Corinne , Karaca Melis , Nubel Tobias , Zavala Flora , Ricquier Daniel
Published: November 2007

Infiltration of inflammatory cells into pancreatic islets of Langerhans and selective destruction of insulin-secreting β-cells are characteristics of type 1 diabetes. Uncoupling protein 2 (UCP2) is a mitochondrial protein expressed in immune cells. UCP2 controls macrophage activation by modulating the production of mitochondrial reactive oxygen species (ROS) and MAPK signaling. We investigated the role of UCP2 on immune cell activity in type 1 diabetes in Ucp2-deficient mice. Using the model of multiple low-dose streptozotocin (STZ)-induced diabetes, we found that autoimmune diabetes was strongly accelerated in Ucp2-KO mice, compared with Ucp2-WT mice with increased intraislet lymphocytic infiltration. Macrophages from STZ-treated Ucp2-KO mice had increased IL-1β and nitric oxide (NO) production, compared with WT macrophages. Moreover, more macrophages were recruited in islets of STZ-treated Ucp2-KO mice, compared with Ucp2-WT mice. This finding also was accompanied by increased NO/ROS-induced damage. Altogether, our data show that inflammation is stronger in Ucp2-KO mice and islets, leading to the exacerbated disease in these mice. Our results highlight the mitochondrial protein UCP2 as a new player in autoimmune diabetes.
The Army of Nader Shah
Authors: Axworthy Michael
Published: November 2007

This article looks at the origins of the army of Nader Shah (reigned 1736–1747) and the nature of the Persian armies in the Safavid period before considering in more detail the composition and structure of the army at its peak in the early 1740s. It suggests, building on work by Rudi Matthee, that it was only under Nader's tutelage that Persia fully embraced gunpowder weapons and that this initiated a Military Revolution (not just a revolution in technology, but in drill, discipline, and army size as well as ethos) that, but for Nader's untimely death, could have brought about the wider social and economic changes that Geoffrey Parker and others have associated with the Military Revolution in Europe.
The Religious Dimension of Post-Communist “Ethnic” Conflict
Authors: Marsh Christopher
Published: November 2007

Common religious, cultural, and ethnic bonds can hold communities together, while differences along these same lines often lead to calls for national independence, complicate nation building, and confound inter-communal peacemaking efforts. In particular, when religious differences exist between groups in conflict there is a marked tendency for such differences to become emphasized. This is not to say that religion is the root cause of all internecine and inter-communal conflict, which certainly is not the case. But conflicts become fundamentally altered as they rage on, and factors that were at the root cause of a conflict at its outset may no longer be the primary causes in later stages. That is, once conflicts have significantly evolved, thepriorcauses may no longer be theprimarycauses.
The Synergistic Action of a VEGF‐Receptor Tyrosine‐Kinase Inhibitor and a Sensitizing PDGF‐Receptor Blocker Depends upon the Stage of Vascular Maturation
Authors: Hlushchuk Ruslan , Baum Oliver , Gruber Guenther , Wood Jeanette , Djonov Valentin
Published: November 2007

Objective: To investigate the effects of tyrosine‐kinase inhibitors of vascular endothelial growth factor (VEGF) and platelet‐derived growth factor (PDGF)‐receptors on non‐malignant tissue and whether they depend upon the stage of vascular maturation.

Materials and methods: PTK787/ZK222584 and CGP53716 (VEGF‐ and PDGF‐receptor inhibitor respectively), both alone and combined, were applied on chicken chorioallantoic membrane (CAM).

Results: On embryonic day of CAM development (E)8, only immature microvessels, which lack coverage of pericytes, are present; whereas the microvessels on E12 have pericytic coverage. This development was reflected in the expression levels of pericytic markers (α ‐smooth muscle actin, PDGF‐receptor ß and desmin), which were found by immunoblotting to progressively increase between E8 and E12. Monotherapy with 2 μ g of PTK787/ZK222584 induced significant vasodegeneration on E8, but not on E12. Monotherapy with CGP53716 affected only pericytes. When CGP53716 was applied prior to treatment with 2 μ g of PTK787/ZK222584, vasodegeneration occurred also on E12. The combined treatment increased the apoptotic rate, as evidenced by the cDNA levels of caspase‐9 and the TUNEL‐assay.

Conclusion: Anti‐angiogenic treatment strategies for non‐neoplastic disorders should aim to interfere with the maturation stage of the target vessels: monotherapy with VEGF‐receptor inhibitor for immature vessels, and combined anti‐angiogenic treatment for well developed mature vasculature.
Novel Technique for Estimating Cerebrovascular Permeability Demonstrates Capsazepine Protection Following Ischemia‐Reperfusion
Authors: Gauden Victoria , Hu D.‐E. , Kurokawa T. , Sarker M. H. , Fraser P. A.
Published: November 2007

Objective: There has been some discussion as to whether the pial vasculature behaves in the same way as the blood‐brain barrier as a whole. Recent studies have shown that capsazepine protects these vessels from the effects of ischemia‐reperfusion. We have now used a new method to examine this protection in the whole brain.

Methods: Horseradish peroxidase concentrations were measured in brain sections and plasma, following starch microsphere induced ischemia, which lasted from 20 to 60 minutes, with 30 minutes reperfusion. The PS product was calculated from the Crone‐Renkin equation.

Results: Permeability increase, which depended on duration of ischemia, was considerably greater in the pia than the parenchyma. The increase was also greater in tissue surrounding large radial venules of the cortex. Single vessel studies showed that these differences mirror those between small and large pial venules. Capsazepine treatment protected the parenchymal blood‐brain barrier by limiting the post‐ischemic permeability increase to about one third, but had no effect on the pia or radial vessel permeability.

Conclusions: Permeability has been estimated in tissue sections with good spatial resolution using this new technique, which has demonstrated that the TRPV1 receptor plays an important role in the whole brain, not confined to small pial venules.
Age‐Related Alterations of Active Pumping Mechanisms in Rat Thoracic Duct
Authors: Gasheva Olga Y. , Knippa Kevin , Nepiushchikh Zhanna V. , Muthuchamy Mariappan , Gashev Anatoliy A.
Published: November 2007

Objective: To evaluate the age‐related changes in active pumping in thoracic duct (TD) from 24‐month‐old Fisher‐344 rats comparing with TD pumping in 9‐month rats.

Methods: Lymphatic diameters, contraction amplitude and frequency, ejection fraction, and fractional pump flow were determined in isolated TD preparations. Western blot analyses were performed to evaluate relative levels of eNOS and iNOS in 9‐ and 24‐month‐old TD.

Results: Stretch‐dependent regulation was altered in aged TD especially at higher levels of pressure: the negative inotropy, negative chronotropy and diminished minute pumping (2‐ to 3‐fold decrease) were observed. Physiological NO/imposed‐flow‐dependent inhibition was completely abolished in aged TD, yet NO‐synthase blockade by l‐NAME (10−4 M) increased pumping in a flow‐independent manner. Western blot analyses indicated that the relative levels of eNOS were decreased ∼ 7‐fold in the 24‐month‐old TD when compared with 9‐month‐old TD; whereas iNOS levels were increased ∼ 10‐fold in 24‐month‐old TD.

Conclusions: These data provide the first evidence that stretch‐ and imposed‐flow‐dependent regulatory mechanisms are greatly altered in aged TD. These alterations of active pumping mechanisms in TD appear to be related with age‐related disturbances in NO‐dependent regulatory pathways, and may reflect diminished lymphatic muscle contractility as well as altered lymphatic endothelium function.
Supporting staff working with prisoners who self‐harm: A survey of support services for staff dealing with self‐harm in prisons in England and Wales
Authors: Marzano Lisa , Adler Joanna R.
Published: November 2007

Research has consistently shown that staff working with people who self‐harm tend to experience a range of anxieties and negative emotions. Very little has been written on the particular issues and needs of staff in prisons, where rates of self‐harm are high. The current study gathered information about existing sources of support for staff dealing with prisoners who self‐harm, and identified positive practice examples. A postal survey was sent out to the Suicide Prevention Team Leaders from every HM Prison Service Establishment in England and Wales (139 in total). Fifty‐four surveys (38.8%) were completed and returned. Findings indicate that staff support services were reportedly in place in virtually all 54 establishments. However, the data suggest that even when present, provisions may not have adequately met the needs of staff working with prisoners who self‐harm, particularly when dealing with ‘repetitive’ self‐harming behaviours. These findings are discussed in relation to organizational health literature. Their practical and theoretical implications are considered, together with directions for further studies in this under‐researched area.
Low folding propensity and high translation efficiency distinguishin vivosubstrates of GroEL from otherEscherichia coliproteins
Authors: Noivirt-Brik Orly , Unger Ron , Horovitz Amnon
Published: November 2007

Motivation: Theoretical considerations have indicated that the amount of chaperonin GroEL in Escherichia coli cells is sufficient to fold only ∼2–5% of newly synthesized proteins under normal physiological conditions, thereby suggesting that only a subset of E.coli proteins fold in vivo in a GroEL-dependent manner. Recently, members of this subset were identified in two independent studies that resulted in two partially overlapping lists of GroEL-interacting proteins. The objective of the work described here was to identify sequence-based features of GroEL-interacting proteins that distinguish them from other E.coli proteins and that may account for their dependence on the chaperonin system.

Results: Our analysis shows that GroEL-interacting proteins have, on average, low folding propensities and high translation efficiencies. These two properties in combination can increase the risk of aggregation of these proteins and, thus, cause their folding to be chaperonin-dependent. Strikingly, we find that these properties are absent in proteins homologous to the E.coli GroEL-interacting proteins in Ureaplasma urealyticum, an organism that lacks a chaperonin system, thereby confirming our conclusions.

Contact:  amnon.horovitz@weizmann.ac.il

Supplementary information: Supplementary data are available at Bioinformatics online.
Detecting high-order interactions of single nucleotide polymorphisms using genetic programming
Authors: Nunkesser Robin , Bernholt Thorsten , Schwender Holger , Ickstadt Katja , Wegener Ingo
Published: November 2007

Motivation: Not individual single nucleotide polymorphisms (SNPs), but high-order interactions of SNPs are assumed to be responsible for complex diseases such as cancer. Therefore, one of the major goals of genetic association studies concerned with such genotype data is the identification of these high-order interactions. This search is additionally impeded by the fact that these interactions often are only explanatory for a relatively small subgroup of patients. Most of the feature selection methods proposed in the literature, unfortunately, fail at this task, since they can either only identify individual variables or interactions of a low order, or try to find rules that are explanatory for a high percentage of the observations. In this article, we present a procedure based on genetic programming and multi-valued logic that enables the identification of high-order interactions of categorical variables such as SNPs. This method called GPAS cannot only be used for feature selection, but can also be employed for discrimination.

Results: In an application to the genotype data from the GENICA study, an association study concerned with sporadic breast cancer, GPAS is able to identify high-order interactions of SNPs leading to a considerably increased breast cancer risk for different subsets of patients that are not found by other feature selection methods. As an application to a subset of the HapMap data shows, GPAS is not restricted to association studies comprising several 10 SNPs, but can also be employed to analyze whole-genome data.

Availability: Software can be downloaded from http://ls2-www.cs.uni-dortmund.de/~nunkesser/#Software

Contact:  robin.nunkesser@uni-dortmund.de
TMBpro: secondary structure, β-contact and tertiary structure prediction of transmembrane β-barrel proteins
Authors: Randall Arlo , Cheng Jianlin , Sweredoski Michael , Baldi Pierre
Published: November 2007

Motivation: Transmembrane β-barrel (TMB) proteins are embedded in the outer membranes of mitochondria, Gram-negative bacteria and chloroplasts. These proteins perform critical functions, including active ion-transport and passive nutrient intake. Therefore, there is a need for accurate prediction of secondary and tertiary structure of TMB proteins. Traditional homology modeling methods, however, fail on most TMB proteins since very few non-homologous TMB structures have been determined. Yet, because TMB structures conform to specific construction rules that restrict the conformational space drastically, it should be possible for methods that do not depend on target-template homology to be applied successfully.

Results: We develop a suite (TMBpro) of specialized predictors for predicting secondary structure (TMBpro-SS), β-contacts (TMBpro-CON) and tertiary structure (TMBpro-3D) of transmembrane β-barrel proteins. We compare our results to the recent state-of-the-art predictors transFold and PRED-TMBB using their respective benchmark datasets, and leave-one-out cross-validation. Using the transFold dataset TMBpro predicts secondary structure with per-residue accuracy (Q2) of 77.8%, a correlation coefficient of 0.54, and TMBpro predicts β-contacts with precision of 0.65 and recall of 0.67. Using the PRED-TMBB dataset, TMBpro predicts secondary structure with Q2 of 88.3% and a correlation coefficient of 0.75. All of these performance results exceed previously published results by 4% or more. Working with the PRED-TMBB dataset, TMBpro predicts the tertiary structure of transmembrane segments with RMSD <6.0 Å for 9 of 14 proteins. For 6 of 14 predictions, the RMSD is <5.0 Å, with a GDT_TS score greater than 60.0.

Availability:  http://www.igb.uci.edu/servers/psss.html

Contact:  pfbaldi@ics.uci.edu

Supplementary information: Supplementary data are available at Bioinformatics online.
GWAsimulator: a rapid whole-genome simulation program
Authors: Li Chun , Li Mingyao
Published: November 2007

Summary: GWAsimulator implements a rapid moving-window algorithm to simulate genotype data for case-control or population samples from genomic SNP chips. For case-control data, the program generates cases and controls according to a user-specified multi-locus disease model, and can simulate specific regions if desired. The program uses phased genotype data as input and has the flexibility of simulating genotypes for different populations and different genomic SNP chips. When the HapMap phased data are used, the simulated data have similar local LD patterns as the HapMap data. As genome-wide association (GWA) studies become increasingly popular and new GWA data analysis methods are being developed, we anticipate that GWAsimulator will be an important tool for evaluating performance of new GWA analysis methods.

Availability: The C++ source code, executables for Linux, Windows and MacOS, manual, example data sets and analysis program are available at http://biostat.mc.vanderbilt.edu/GWAsimulator

Contact:  chun.li@vanderbilt.edu

Supplementary information: Supplementary data are available at Bioinformatics online.
Chemical synoviorthesis with oxytetracycline clorhydrate (Emicine®) in recurrent haemarthrosis
Authors: FERNÁNDEZ‐PALAZZI F. , CEDEÑO M. , MALDONADO J. C. , BOADAS A. , DE SAEZ A. R. , CHACAL B. F. , DE BOSCH N. B.
Published: November 2007

Summary.  This is a non‐controlled experimental prospective clinical study that evaluates the satisfactory results in the chemical synovectomy (synoviorthesis) with oxytetracycline clorhydrate (Emicine®, Lab. Pfizer Ltda, Guarulhos, Sao Paulo, Brazil) in recurrence haemarthrosis in different joints, demonstrating that it is an effective method in the treatment of these recurrent haemarthrosis in haemophilia. 84 patients of whom 77 concluded the full course of treatment. 82 joints were injected. The dosage injected was 5 cm3 of the drug (25 mg) in 5 cm3 of anaesthesia for the knee, 2 cm3 with 1 cm3 of anaesthesia for the elbow and 1 cm3 plus 1 cm3 of anaesthesia for the ankle. These injections were administered once weekly with a reinforcement in 1 month. In case of failure the same can be administered repeatedly. Subjective parameters included pain, range of movement and use of the joint involved. Pain decreased from a mean of 6.5 to 0.9 (Likert scale). Range of movement increased from 5.9 to 9 and joint use increased from 5.9 to 9.2. Objective parameters included joint diameter and range of movement. Range of movement for flexion and extension improved from 72.2 and 149.2 to 73.7 and 167, respectively, for the knees. From 57.3 and 160 to 66.6 and 170, respectively, for the shoulder. And, from 22.7 and 10.8 to 34 and 18.6, respectively, for the ankle. This procedure has multiple advantages such as immediate therapeutic effect, short period of treatment, easy technique, much less AHF coverage (30% above coagulation level), less costly than radiocolloid treatment, which make it a perfect alternative treatment for developing countries.
Sensitivity to Escherichia coli Nissle 1917 in mice is dependent on environment and genetic background
Authors: Bleich Andre , Sundberg John P. , Smoczek Anna , Von Wasielewski Reinhard , De Buhr Maike F. , Janus Lydia M. , Julga Gwen , Ukena Sya N. , Hedrich Hans‐J. , Gunzer Florian
Published: November 2007

Escherichia coli Nissle 1917 (EcN) is a well‐characterized probiotic bacterium. Although genomic comparisons of EcN with the uropathogenic E. coli strain CFT073 revealed high degrees of similarity, EcN is generally considered a non‐pathogenic organism. However, as recent evidence suggests that EcN is capable of inducing inflammatory responses in host intestinal epithelial cells, we aimed to investigate potential pathogenic properties of EcN in an in vivo model using various germ‐free (GF) mouse strains. With the exception of C3H/HeJZtm mice, which carry a defective toll‐like receptor (TLR)4‐allele, no lesions were obvious in mice of different strains orally inoculated with EcN for 1 week, although organ cultures (blood, lung, mesenteric lymph node, pancreas, spleen, liver and kidney) tested positive to various degrees. C3H/HeJZtm mice inoculated with EcN became clinically ill and the majority died or had to be euthanized. Organs of all gnotobiotic C3H/HeJZtm mice were positive for EcN by culture; major histological findings were moderate to severe pyogranulomatous serositis, typhlitis and pancreatitis. Histological findings were corroborated by highly elevated tumour necrosis factor (TNF) serum levels. Lesions were not detected in specified pathogen free maintained C3H/HeJZtm mice, GF C3H/HeJ mice lacking the interleukin‐10 gene, or GF C3H/HeJZtm mice that were inoculated with E. coli K12 strain MG1655 as a control. In addition, mild histological lesions were detected in Ztm:NMRI mice 3 months after oral inoculation with EcN. This study shows that EcN is capable of displaying a virulent phenotype in GF C3H/HeJZtm mice. Whether this phenotype is linked to the bacterium’s probiotic nature should be the focus of further studies.
Role of p38 mitogen‐activated protein kinase pathway on heart failure in the infant rat after burn injury
Authors: Kita Toshiro , Ogawa Midori , Sato Hiroaki , Kasai Kentaro , Tanaka Toshiko , Tanaka Noriyuki
Published: November 2007

We examined the hypothesis that post‐burn activation of the p38 mitogen‐activated protein kinase (MAPK) pathway is one aspect of the signalling cascade culminating in post‐burn secretion of tumour necrosis factor (TNF)‐α which contributes to post‐burn myocardial apoptosis. Studies were designed to determine the time course of the induction of p38MAPK, TNF‐α and myocardial apoptosis after burn injury. Our quantitative bacterial culture data demonstrated that viable bacteria reached the heart, and Western blotting data identified the increase in the phosphorylation of p38MAPK at an early time after burn. The peak incidence of myocardial apoptosis was also seen at an early time after burn. The expression of TNF‐α mRNA, infiltrated neutrophils and serum creatine phosphokinase myocardial band data peaked at a late time after burn. FR167653, a specific inhibitor of p38MAPK, prevented the induction of myocardial apoptosis, TNF‐α expression and myocardial injury after burn. Presumably, the bacterial LPS‐induced activation of p38MAPK pathway occurring at an early time after burn induced the subsequent myocardial apoptosis. The p38MAPK‐induced activation of pro‐inflammatory cytokine appeared to promote the degenerative myocardial injury at a late time after burn. Our present data provided evidence for the hypothesis that the p38MAPK pathway controls both myocardial apoptosis and the pro‐inflammatory mediator.
Effects of pasture management on the natural regeneration of neotropical trees
Authors: Esquivel M. Jimena , Harvey Celia A. , Finegan Bryan , Casanoves Fernando , Skarpe Christina
Published: November 2007

Natural regeneration of forest trees in grazed pastures could potentially contribute to the conservation of tree diversity within the fragmented and agricultural landscapes that dominate much of the tropics. To understand this potential, we evaluated the effects of several widely used pasture management practices on tree regeneration in pastures in a tropical dry forest (subhumid) region of central Nicaragua.

Species richness, density, diversity and composition of seedlings, saplings and adult trees were compared in 46 pastures under different management conditions. The management conditions included three different types of grasses (Brachiaria spp., Cynodon spp. and naturalized pastures) and two categories of fire history (recently burnt and not recently burnt).

Thirty‐seven of the 85 tree species present in the pastures were regenerated under the current management conditions. The remaining 48 species may have had reduced natural regeneration because of limitations in either germination, dispersal, establishment or growth, as well as because of negative effects of pasture management practices.

The richness, density and species composition of tree seedlings within pastures were explained by grass species composition, the density and richness of adult trees, cattle management and the distance of the pasture to forest. In contrast, no clear effect of fire history was found.

Synthesis and applications. Current management practices allow the regeneration of almost half of the tree species in grazed pastures. However, to enhance the regeneration of species that show limited regeneration, management strategies, such as the retention of adult trees, protection of saplings and seedlings from weeding and grazing and use of enrichment plantings, may be necessary. These changes in pasture management would help contribute to the long‐term conservation of tree diversity within agricultural landscapes across the tropics.
Monte Carlo analysis of parameter uncertainty in matrix models for the weed Cirsium vulgare
Authors: Tenhumberg Brigitte , Louda Svata M. , Eckberg James O. , Takahashi Masaru
Published: November 2007

Parameter uncertainty challenges the use of matrix models because it violates key assumptions underlying elasticity analyses. We have developed a matrix model to compare Monte Carlo methods with elasticity analyses for estimation of the relative importance of factors in the asymptotic population growth rate, λ, of Cirsium vulgare (spear thistle) in Nebraska, USA.

We calculated λ for a base model using 11 parameter estimates available for Nebraska populations plus eight extracted from the literature, causing parameter uncertainty. We then calculated λ for 10 000 alternative models using Monte Carlo parameter estimation; parameters were drawn from the full range of each parameter in the literature and partial rank correlation analysis (PRCC) was used to order the parameters by the magnitude of their effect on λ.

Monte Carlo analysis found that insect floral herbivory, affecting the regeneration transition, was the most important parameter affecting λ, whereas elasticity analyses suggested that the transition from small to medium size was the most significant. Statistical comparison, using PRCC vs. lower level elasticity (LLE), showed that the Monte Carlo analysis provided a more accurate assessment.

As λ > 1 in 99% of the model runs even with significant floral herbivory, we added two parameters influenced by weed management (probability of large thistles dying without producing seed and proportion of seeds that failed to germinate). Simulations that included reductions in these parameters, along with floral herbivory, led to λ < 1 in 17% of the runs, suggesting these three factors interact to produce the low densities observed for this invasive thistle in our study area.

Synthesis and applications. This study demonstrates the utility of the Monte Carlo approach for modelling weed dynamics with parameter uncertainty and multiple, potentially interacting, parameters. Invasive population growth by C. vulgare could be limited by a combination of weed management practices and the biotic resistance imposed by native floral herbivores.
Influence of bioclimatic variables on tree‐line conifer distribution in the Greater Yellowstone Ecosystem: implications for species of conservation concern
Authors: Schrag Anne M. , Bunn Andrew G. , Graumlich Lisa J.
Published: November 2007

Aim  Tree‐line conifers are believed to be limited by temperature worldwide, and thus may serve as important indicators of climate change. The purpose of this study was to examine the potential shifts in spatial distribution of three tree‐line conifer species in the Greater Yellowstone Ecosystem under three future climate‐change scenarios and to assess their potential sensitivity to changes in both temperature and precipitation.

Location  This study was performed using data from 275 sites within the boundaries of Yellowstone and Grand Teton national parks, primarily located in Wyoming, USA.

Methods  We used data on tree‐line conifer presence from the US Forest Service Forest Inventory and Analysis Program. Climatic and edaphic variables were derived from spatially interpolated maps and approximated for each of the sites. We used the random‐forest prediction method to build a model of predicted current and future distributions of each of the species under various climate‐change scenarios.

Results  We had good success in predicting the distribution of tree‐line conifer species currently and under future climate scenarios. Temperature and temperature‐related variables appeared to be most influential in the distribution of whitebark pine (Pinus albicaulis), whereas precipitation and soil variables dominated the models for subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii). The model for whitebark pine substantially overpredicted absences (as compared with the other models), which is probably a result of the importance of biological factors in the distribution of this species.

Main conclusions  These models demonstrate the complex response of conifer distributions to changing climate scenarios. Whitebark pine is considered a ‘keystone’ species in the subalpine forests of western North America; however, it is believed to be nearly extinct throughout a substantial portion of its range owing to the combined effects of an introduced pathogen, outbreaks of the native mountain pine beetle (Dendroctonus ponderosae), and changing fire regimes. Given predicted changes in climate, it is reasonable to predict an overall decrease in pine‐dominated subalpine forests in the Greater Yellowstone Ecosystem. In order to manage these forests effectively with respect to future climate, it may be important to focus attention on monitoring dry mid‐ and high‐elevation forests as harbingers of long‐term change.
Sense of coherence and experiences of social support and mastery in the early discharge period after an acute cardiac event
Authors: Hildingh Cathrine , Fridlund Bengt , Baigi Amir
Published: November 2007

Aims and objectives.  The aim of this study was to examine sense of coherence and experiences of change in social support and mastery from a short‐term perspective in patients who had been admitted to hospital with a suspected myocardial infarction.

Background.  The early discharge period after an acute cardiac event can be a stressful and vulnerable time when psychosocial resources are of the utmost importance. A positive outcome in an encounter with a stressor is thought to be linked to a strong sense of coherence, social support and mastery.

Design.  A multi‐centre survey was conducted in three hospitals in southern Sweden.

Methods.  The sample was 300, 241 of whom completed the questionnaires; while in hospital and two weeks postdischarge.

Results.  In the early discharge period a low sense of coherence was found in over 60% of the sample. There was an association between social support and mastery and between sense of coherence and mastery. Differences in social support ratings, with lower ratings two weeks postdischarge, were found among women and persons over 65 years of age.

Conclusions.  This study adds knowledge about experiences in the early discharge period. Changes in ratings of social support but not in ratings of mastery were found between baseline and two weeks postdischarge.

Relevance to clinical practice.  Healthcare professionals need to be sensitive to patients’ sense of coherence, mastery and need for social support during the early discharge period. They can help patients to identify adequate support strategies and prevent future potential complications. However, to routinely assess sense of coherence, social support and mastery, there is a need for a simple and useful instrument in clinical practice.
Alpha‐smooth muscle actin (α‐SMA) and nestin expression in reactive astrocytes in multiple sclerosis lesions: potential regulatory role of transforming growth factor‐beta 1 (TGF‐β1)
Authors: Moreels M. , Vandenabeele F. , Dumont D. , Robben J. , Lambrichts I.
Published: November 2007

Aims: Rapid and extensive activation of astrocytes occurs subsequent to many forms of central nervous system (CNS) injury. Recent studies have revealed that the expression profile of reactive astrocytes comprises antigens present during astrocyte development. Elevated levels of the injury‐related cytokine transforming growth factor‐beta 1 (TGF‐β1) secreted by microglial cells and invading macrophages have been correlated with the reactive astrocyte phenotype and glial scar formation. Methods: In the present study, the expression profile of alpha‐smooth muscle actin (α‐SMA) and nestin, two cytoskeletal proteins expressed during astrocyte development, was studied in multiple sclerosis (MS) lesions. In addition, α‐SMA and nestin organization and expression were analysed in rat primary astrocyte cultures in response to TGF‐β1. Results: In active lesions and in the hypercellular margin of chronic active MS lesions, immunostaining for α‐SMA revealed a subpopulation of reactive astrocytes, whereas the majority of reactive astrocytes expressed nestin. α‐SMA and nestin expressing reactive astrocytes were in close relationship with TGF‐β1 expressing macrophages or microglia. In addition, TGF‐β1 expression within α‐SMA or nestin expressing astrocytes was also detected. Our in vitro experiments showed that TGF‐β1 regulated the organization and expression of α‐SMA and nestin in astrocytes. Conclusions: Reactive astrocytes in active MS lesions re‐express α‐SMA and nestin. We suggest that the in vivo re‐expression might be under regulation of TGF‐β1. These results further clarify the regulation of astrocyte activity after CNS injury, which is important for the astroglial adaptation to pathological situations.
Major histocompatibility complex typing of dogs from Russia shows further dog leukocyte antigen diversity
Authors: Kennedy L. J. , Brown J. J. , Barnes A. , Ollier W. E. R. , Knyazev S.
Published: November 2007

Blood samples from 85 Russian dogs and wolves were collected as dried blood spots on paper and transported to the UK by mail. We obtained partial or complete three‐locus canine major histocompatibility complex [dog leukocyte antigen (DLA)] class II haplotypes on 81 of these samples. Six new alleles were identified: three DLA‐DRB1 and three DLA‐DQB1. These alleles occurred in haplotypic combinations not previously seen in other European dogs. One haplotype appeared to lack a DQB1 allele. Two of the new haplotypes segregated through a family of dogs that was investigated.
Application of the particle gel agglutination assay in the typing of single human leucocyte antigens
Authors: Meyer O. , Agaylan A. , Schönemann C. , Kiesewetter H. , Salama A.
Published: November 2007

We describe a simple and rapid particle gel agglutination assay (PaGIA) for typing of the human leucocyte antigens (HLA) HLA‐A2, HLA‐B7 and HLA‐B27. Superparamagnetic streptavidin particles were coated with biotinylated monoclonal antibodies (MoAbs) to HLA‐A2, HLA‐B7 and HLA‐B27. Anticoagulated whole blood samples from healthy blood donors (n = 118) with known HLA patterns were incubated with MoAb‐coated particles, transferred into a standard ID‐gel card, and subsequently centrifuged. Samples were evaluated macroscopically, with antigen‐positive samples resulting in a visible agglutination reaction. A clear distinction could be made between all positive and negative samples tested. Fifty‐seven samples were found to be positive for HLA‐A2 (48%), 26 samples for HLA‐B7 (22%) and 5 samples for HLA‐B27 (4%).
Successful treatment of refractory Langerhans cell histiocytosis by allogeneic peripheral blood stem cell transplantation
Authors: Lai Chi‐Chieh , Huang Wen‐Chin , Cheng Shin‐Nan
Published: November 2007

Abstract:  We describe a six‐yr‐old boy who exhibited typical signs and symptoms of LCH with EBV‐associated hemophagocytic syndrome from the age of 15 months. Multiple courses of conventional chemotherapy achieved only marginal improvement over the ensuring five yr. During this period, this boy experienced recurrent episodes of hemophagocytic syndrome associated with CMV infection. Five yr after the first diagnosis of LCH, the patient was treated with allogeneic PBSCT from his HLA‐identical eight‐yr‐old brother. PBSCT was performed using a TBI‐incorporating conditioning regimen comprising TBI, busulfan, and cyclophosphamide. Diabetes insipidus, typically a permanent consequence of LCH, was well controlled by DDAVP therapy. At the time of writing, this boy is alive and well, and had been disease‐free for more than two yr after the PBSCT.
Differential changes in photosynthetic capacity, 77 K chlorophyll fluorescence and chloroplast ultrastructure between Zn‐efficient and Zn‐inefficient rice genotypes (Oryza sativa) under low zinc stress
Authors: Chen Wenrong , Yang Xiaoe , He Zhenli , Feng Ying , Hu Fenghong
Published: November 2007

The relationship of zinc (Zn) efficiency in rice to differential tolerance of photosynthetic capacity and chloroplast function to low Zn stress was studied using Zn‐efficient (IR8192) and Zn‐inefficient (Erjiufeng) rice genotypes (Oryza sativa L.). Zinc deficiency caused extensive declines in leaf chlorophyll (Chl) content, ratios of chl a:b, Pn, Fv/Fm and Fv/Fo, indicating that the intrinsic quantum efficiency of the photosystem II (PSII) units was damaged. A greater decline was observed in the inefficient genotype (Erjiufeng) than the efficient genotype (IR8192). The 77 K chl fluorescence emission spectrum revealed that Zn deficiency blocked energy spillover from PSII to PSI and more excitation energy was distributed to PSII in IR8192 than Erjiufeng. The spectrum of Zn‐deficient Erjiufeng was completely disordered, implying that the photosynthetic centers were seriously damaged. Electron microscopy showed that Zn deficiency caused a severe damage to the fine structure of chloroplasts, but IR8192 had a better preserved chloroplast ultrastructure as compared with Erjiufeng. These differences may result from the higher levels of the antioxidant enzyme activities and lower oxidant stress level in IR8192. These results indicate that Zn deficiency decreases leaf photosynthetic capacity primarily by reducing the number of PSII units per unit leaf area, and also reducing the photochemical capacity of the remaining PSII units. Therefore, the maintenance of more efficient photochemical capacity under low Zn stress is a key factor for the high Zn efficiency in rice, which may result from less antioxidant damage caused by low Zn to the chloroplast ultrastructure.