bluuebunny/crossref_metadata_2025 huggingface dataset:
What is the relationship between changes in canopy leaf area and changes in photosynthetic CO2 flux in arctic ecosystems?
Authors: STREET L. E. , SHAVER G. R. , WILLIAMS M. , VAN WIJK M. T.
Published: November 2006

The arctic environment is highly heterogeneous in terms of plant distribution and productivity. If we are to make regional scale predictions of carbon exchange it is necessary to find robust relationships that can simplify this variability. One such potential relationship is that of leaf area to photosynthetic CO2 flux at the canopy scale.

In this paper we assess the effectiveness of canopy leaf area in explaining variation in gross primary productivity (GPP): (i) across different vegetation types; (ii) at various stages of leaf development; and (iii) under enhanced nutrient availability. To do this we measure net CO2 flux light response curves with a 1 × 1 m chamber, and calculate GPP at a photosynthetic photon flux density (PPFD) of 600 µmol m−2 s−1.

At a subarctic site in Sweden, we report 10‐fold variation in GPP among natural vegetation types with leaf area index (LAI) values of 0.05–2.31 m2 m−2. At a site of similar latitude in Alaska we document substantially elevated rates of GPP in fertilized vegetation.

We can explain 80% of the observed variation in GPP in natural vegetation (including vegetation measured before deciduous leaf bud burst) by leaf area alone, when leaf area is predicted from measurements of normalized difference vegetation index (NDVI).

In fertilized vegetation the relative increase in leaf area between control and fertilized treatments exceeds the relative increase in GPP. This suggests that higher leaf area causes increased self‐shading, or that lower leaf nitrogen per unit leaf area causes a reduction in the rate of photosynthesis.

The results of this study indicate that canopy leaf area is an excellent predictor of GPP in diverse low arctic tundra, across a wide range of plant functional types.
Adjustment of children who have a sibling with Down syndrome: perspectives of mothers, fathers and children
Authors: Cuskelly M. , Gunn P.
Published: November 2006

Background  A number of methodological weaknesses have contributed to our relatively poor understanding of the impact on children of having a brother or sister with a disability. These include a focus on poor adjustment, using multidiagnostic groups, inadequate matching, and a failure to consider the perspectives of children and parents together.

Method  This study compared the adjustment of 53 siblings of a child with Down syndrome with a comparison group of siblings of children who were developing typically. Children were matched on a case‐by‐case basis for gender, age and position in family. Families were matched for family size and father’s occupation. The age range of the target siblings was 7–14 years. Data were gathered from mothers, fathers and siblings.

Results  There were no significant differences between the groups on adjustment measures. These included parent perceptions of externalizing and internalizing behaviours, parent perceptions of sibling competence, and sibling perceptions of their own competence and self‐worth. Associations between measures of adjustment and child reports of their contribution to household functioning depended on sex rather than group membership. There was an association between parental reports of externalizing behaviour and sibling relationships with the brother/sister closest in age.

Conclusions  Having a brother or sister with Down syndrome does not inevitably lead to poor adjustment. Examination of within‐family processes would appear to be more useful in identifying children at risk than merely group membership.
Transmission electron microscopy studies of microstructure of Ti–Nb and Ti–Ta alloys after ball milling and hot consolidation
Authors: MAZIARZ W. , LEJKOWSKA M. , MICHALSKI A. , DUTKIEWICZ J.
Published: November 2006

Two Ti alloys with compositions Ti−10Ta and Ti−10Nb (at.%) were milled in a high‐energy mill for a maximum of 80 h in an argon atmosphere. A nanocrystalline structure of α‐Ti(X) (X = Ta or Nb) solid solution was formed in both investigated alloys after milling, as shown by X‐ray diffraction. Transmission electron microscopy observations of powders milled for 80 h revealed chemical inhomogeneity of particles in nanometre‐scale regions and an average crystallite size of about 10 nm. The pulse plasma sintering method was applied for hot consolidation of milled powders. The mean density of pulse plasma sintering compacts of Ti–Nb alloy was about 99.5% of the theoretical value, whereas the density of the Ti−10Ta sample was lower, close to 92% of the theoretical value. Transmission electron microscopy observation of compacted samples showed that the sintering process caused the formation of a two‐phase α + β structure in both investigated alloys, with a mean grain size of 220 nm. The chemical inhomogeneity and high degree of deformation in nanometre‐scale regions of milled powders led to a martensitic transformation, resulting in formation of a 9R martensite structure.
Structural analyses of Nd‐doped CeO2 thin films deposited by pulsed laser deposition
Authors: KOPIA A. , CHMIELOWSKA M. , LEROUX CH. , DALLAS J. P. , GAVARRI J. R. , KUSIŃSKI J.
Published: November 2006

CeO2 thin films doped with neodymium oxides for application to gas sensors have been elaborated by the pulsed laser deposition technique. The films were deposited on orientated Si (100) substrates with variable deposition times (t = 90, 180 and 360 s) and molar fractions of Nd2O3 (0, 6.5, 15, 21.5 and 27 at.%). The resulting Nd–CeO2 thin films were characterized by means of X‐ray diffraction analysis, scanning electron microscopy and transmission electron microscopy equipped with EDS (Energy Dispersive Spectrometer) microanalysis. From X‐ray diffraction analyses, it is clearly established that the texture is modified by Nd additions. The preferred (111) orientations of the CeO2 crystals change into the (200) orientation. The morphology of the CeO2 grains changes from triangles, for pure CeO2 thin films, to spherical grains for Nd‐doped films. In addition, cell parameter analyses from X‐ray diffraction data show that a partial chemical substitution of Ce by Nd should occur in the face‐centred cubic lattice of ceria: this should give rise to Ce1‐xNdxO2−z phases with oxygen non‐stoichiometry.
Compensation of the shadowing error in three‐dimensional imaging with a multiple detector scanning electron microscope
Authors: PALUSZYŃSKI J. , SLÓWKO W.
Published: November 2006

A method for three‐dimensional quantitative surface characterization for scanning electron microscopy is presented. The method used a quadruple scintillator detector developed by us. A surface reconstruction algorithm was performed by special software, with new algorithms for error compensation. Among these errors, detector shadowing was of particular importance. This was due to the disturbance in integration continuity when one or more detectors was screened from the flow of electrons. Several methods for the reduction of this error have been proposed and tested by us. The methods were based on software processing of complementary information, such as unshadowed detector signals, shadow depth and modified integration schemes.
An experimental investigation of sand–mud suspension settling behaviour: implications for bimodal mud contents of submarine flow deposits
Authors: AMY LAWRENCE A. , TALLING PETER J. , EDMONDS VICTORIA O. , SUMNER ESTHER J. , LESUEUR ANNE
Published: November 2006

The settling behaviour of particulate suspensions and their deposits has been documented using a series of settling tube experiments. Suspensions comprised saline solution and noncohesive glass‐ballotini sand of particle size 35·5 μm < d < 250 μm and volume fractions, φs, up to 0·6 and cohesive kaolinite clay of particle size d < 35·5 μm and volume fractions, φm, up to 0·15. Five texturally distinct deposits were found, associated with different settling regimes: (I) clean, graded sand beds produced by incremental deposition under unhindered or hindered settling conditions; (II) partially graded, clean sand beds with an ungraded base and a graded top, produced by incremental deposition under hindered settling conditions; (III) graded muddy sands produced by compaction with significant particle sorting by elutriation; (IV) ungraded clean sand produced by compaction and (V) ungraded muddy sand produced by compaction. A transition from particle size segregation (regime I) to suppressed size segregation (regime II or III) to virtually no size segregation (IV or V) occurred as sediment concentration was increased. In noncohesive particulate suspensions, segregation was initially suppressed at φs ∼ 0·2 and entirely inhibited at φs ≥ 0·6. In noncohesive and cohesive mixtures with low sand concentrations (φs < 0·2), particle segregation was initially suppressed at φm ∼ 0·07 and entirely suppressed at φm ≥ 0·13. The experimental results have a number of implications for the depositional dynamics of submarine sediment gravity flows and other particulate flows that carry sand and mud; because the influence of moving flow is ignored in these experiments, the results will only be applicable to flows in which settling processes, in the depositional boundary, dominate over shear‐flow processes, as might be the case for rapidly decelerating currents with high suspended load fallout rates. The ‘abrupt’ change in settling regimes between regime I and V, over a relatively small change in mud concentration (<5% by volume), favours the development of either mud‐poor, graded sandy deposits or mud‐rich, ungraded sandy deposits. This may explain the bimodality in sediment texture (clean ‘turbidite’ or muddy ‘debrite’ sand or sandstone) found in some turbidite systems. Furthermore, it supports the notion that distal ‘linked’ debrites could form because of a relatively small increase in the mud concentration of turbidity currents, perhaps associated with erosion of a muddy sea floor. Ungraded, clean sand deposits were formed by noncohesive suspensions with concentrations 0·2 ≤ φs ≤ 0·4. Hydrodynamic sorting is interpreted as being suppressed in this case by relatively high bed aggradation rates which could also occur in association with sustained, stratified turbidity currents or noncohesive debris flows with relatively high near‐bed sediment concentrations.
The Arabidopsis cinnamoyl CoA reductase irx4 mutant has a delayed but coherent (normal) program of lignification
Authors: Laskar Dhrubojyoti D. , Jourdes Michaël , Patten Ann M. , Helms Gregory L. , Davin Laurence B. , Lewis Norman G.
Published: November 2006

Previous studies have indicated that the Arabidopsis thalianairregular xylem 4 (irx4) mutant is severely lignin‐deficient, forming abnormal lignin from aberrant monomers. Studies of lignin structure in dwarfed cinnamoyl CoA reductase (CCR)‐downregulated tobacco were also previously reported to incorporate feruloyl tyramine derivatives. The lignin in the Arabidopsis irx4 mutant was re‐investigated at 6 weeks and at maturation (9 weeks). Application of 1H, 13C, 2D Heteronuclear Multiple Quantum Coherence and 2D Heteronuclear Multiple Bond Coherence spectroscopic analyses to the lignin‐enriched isolates from both Arabidopsis wild‐type (Ler) and the CCR‐irx4 mutant at both developmental stages revealed that only typical guaiacyl/syringyl lignins were formed. For the irx4 mutant, the syringyl content at 6 weeks growth was lower, in accordance with a delayed but coherent program of lignification. At maturation, however, the syringyl/guaiacyl ratio of the irx4 mutant approached that of wild‐type. There was no evidence for feruloyl tyramines, or homologues thereof, accumulating as a chemical signature in lignins resulting from CCR mutation. Nor were there any noticeable increases in other phenolic components, such as hydroxycinnamic acids. These findings were further confirmed by application of thioacidolysis, alkaline nitrobenzene oxidation and acetyl bromide analyses. Moreover, in the case of CCR downregulation in tobacco, there were no NMR spectroscopic correlations that demonstrated feruloyl tyramines being incorporated into the lignin biopolymers. This study thus found no evidence that abnormal lignin formation occurs when CCR activity is modulated.
FTY720 (fingolimod) in renal transplantation
Authors: Budde Klemens , Schütz Manuela , Glander Petra , Peters Harm , Waiser Johannes , Liefeldt Lutz , Neumayer Hans‐H , Böhler Torsten
Published: November 2006

Abstract:  FTY720 (Fingolimod) is a novel immunomodulator with a mode of action that is completely different from classical immunosuppressants. FTY is a structural and functional analogue of the natural serum lipid, sphingosine, and is the first in a new class of drugs called sphingosine 1‐phosphate receptor (S1P‐R) modulators. This review discusses the recent findings on the mechanism of action, preclinical models and outlines the results of the ongoing clinical development program. FTY is highly effective in prolonging allograft survival in preclinical models of transplantation and in experimental models of autoimmune diseases. In clinical trials, this novel compound was investigated in de novo renal transplantation and in multiple sclerosis. Pharmacokinetics are characterized by a prolonged absorption phase, a large volume of distribution, and a long elimination half‐life. FTY induces a rapid and transient decrease in lymphocyte counts, which supports the modulatory effects of the drug on lymphocyte sequestration. The most common adverse event was asymptomatic transient bradycardia, a pharmacodynamic effect modulated by atrial S1 P‐R. FTY failed to show an improvement in efficacy for the prevention of renal allograft rejection in two large phase III studies. FTY treatment regimens were associated with impaired renal function and the development of macula edema. Consequently, the further development in renal transplantation was stopped. Because initial clinical studies strongly suggest that FTY is highly effective in multiple sclerosis FTY is now being explored in phase III studies for the treatment of demyelinating diseases, Ongoing studies in multiple sclerosis are eagerly awaited because they may provide novel therapeutic options for patients with autominnue diseases.
How to increase inflow in liver transplantation
Authors: Muller S.A. , Schmied B.M. , Welsch T. , Martin D.J. , Schemmer P. , Mehrabi A. , Weitz J. , Buchler M.W. , Schmidt J.
Published: November 2006

Abstract:  Liver transplantation (LTx) has become the treatment of choice for selected cases of benign and malignant liver disease. Despite becoming increasingly safer in recent years this procedure still incurs several serious postoperative complications. The most significant surgical complications are related to surgical technique, particularly the reconstruction and/or anastomosis of the hepatic artery. Arterial hypoperfusion may lead to graft failure, sepsis, or ischemic biliary lesions. In this review we focus on the Achilles’ heel of LTx: the hepatic artery. We provide transplant surgeons with an overview of the technical options that are available to increase arterial inflow and subsequently improve patient outcome. We exemplify some of the discussed techniques using a liver transplant case with an eventful postoperative course because of arterial complications.
Dog leucocyte antigen class II diversity and relationships among indigenous dogs of the island nations of Indonesia (Bali), Australia and New Guinea
Authors: Runstadler J. A. , Angles J. M. , Pedersen N. C.
Published: November 2006

The genetic polymorphism at the dog leucocyte antigen (DLA) class II loci DQA1, DQB1 and DRB1 was studied in a large genetically diverse population of feral and wild‐type dogs from the large island nations of Indonesia (Bali), Australia and New Guinea (Bali street dog, dingo and New Guinea singing dog, respectively). Sequence‐based typing (SBT) of the hypervariable region of DLA‐DRB1, ‐DQA1 and ‐DQB1 alleles was used to determine genetic diversity. No new DQA1 alleles were recognized among the three dog populations, but five novel DLA‐DRB1 and 2 novel DLA‐DQB1 allele sequences were detected. Additional unknown alleles were postulated to exist in Bali street dogs, as indicated by the large percentage of individuals (15%–33%) that had indeterminate DRB1, DQA1 and DQB1 alleles by SBT. All three groups of dogs possessed alleles that were relatively uncommon in conventional purebreds. The New Guinea singing dog and dingo shared alleles that were not present in the Bali street dogs. These findings suggested that the dingo was more closely related to indigenous dogs from New Guinea. Feral dog populations, in particular large ones such as that of Bali, show genetic diversity that existed prior to phenotypic selection for breeds originating from their respective regions. This diversity needs to be identified and maintained in the face of progressive Westernization. These populations deserve further study as potential model populations for the evolution of major histocompatibility complex alleles, for the study of canine genetic diversity, for the development of dog breeds and for studies on the comigration of ancestral human and dog populations.
Plasma cell‐rich acute cellular rejection of a transplanted kidney associated with antibody to the red cell Kidd antigen
Authors: Hamilton Marilyn S. , Singh Vivekanand , Warady Bradley A.
Published: November 2006

Abstract:  Plasma cell‐rich acute cellular rejection of a transplanted kidney is described in association with the identification of serum antibody to the red cell Kidd antigen, Jk‐b, which is also found in the kidney. This antibody was formed without a history of a recent blood transfusion or exposure to intravenous immunoglobulin. The role this antibody could have in the rejection of the transplant is discussed.
Relationship between RNA splicing and exon editing near intron junctions in wheat mitochondria
Authors: Li‐Pook‐Than Jennifer , Carrillo Catherine , Niknejad Nima , Calixte Sophie , Crosthwait Jennifer , Bonen Linda
Published: November 2006

We have compared the RNA editing status of wheat mitochondrial unspliced precursor transcripts with spliced RNAs, focusing in particular on exon editing sites located very close to intron/exon junctions. Using direct sequencing of reverse transcriptase–PCR products to assess C‐to‐U editing in various RNA populations for the respiratory chain genes nad2, nad4, nad5, nad7, and cox2, we observed that candidate exon sites immediately upstream or downstream of introns remained unedited in the presence of the adjacent intron, whereas sites further away were typically partially (or completely) edited in precursor molecules. The ‘late’ editing of exon sites adjacent to splice junctions is consistent with access of the editing machinery being sterically hindered by the intron or alternatively by an editing recognition element being created by the exon/exon structure. When we examined RNA isolated from the embryo‐to‐seedling stages of wheat development, we found that fully spliced messenger RNAs showed editing at the expected sites in all stages, including dormant seeds. In contrast, we observed that cox2 precursors were less completely edited in RNA populations from 0 to 24 h postimbibition embryos than in 6‐day‐old seedlings not only at splice junctions but also at other exon sites, consistent with more efficient coupling between editing and transcription during later stages of development.
The promoters of Arabidopsis thaliana genes AtCOX17‐1 and ‐2, encoding a copper chaperone involved in cytochrome c oxidase biogenesis, are preferentially active in roots and anthers and induced by biotic and abiotic stress
Authors: Attallah Carolina V. , Welchen Elina , Gonzalez Daniel H.
Published: November 2006

AtCOX17 genes encode Arabidopsis thaliana homologs of the yeast metallochaperone Cox17p, involved in the delivery of copper for cytochrome c oxidase (COX) assembly. Two different AtCOX17 genes, located in chromosomes 1 and 3, are present in the Arabidopsis genome. Sequences available in data banks indicate that the presence of two genes is a common feature in monocots, but not in dicots, suggesting that Arabidopsis genes may be the result of a recent duplication. Sequences upstream from the translation start sites of AtCOX17 genes, which include an intron located in the 5′ leader region, were introduced into plants in front of the gus gene. For both genes, expression was localized preferentially in young roots and anthers, but almost 10‐fold higher β‐glucuronidase activity levels were observed in plants transformed with AtCOX17‐1 upstream regions. Both promoters were induced to different extents by wounding, treatment of leaves with the bacterial pathogen Pseudomonas syringae and incubation with agents that produce oxidative stress and metals. AtCOX17‐2 showed similar responses to these factors, while AtCOX17‐1 was more strongly induced by relatively low (10–100 μM) copper. The results indicate that both AtCOX17 genes have similar, though not identical, expression characteristics and suggest the existence in their promoters of elements involved in tissue‐specific expression and in responses to factors that may produce mitochondrial or cell damage. It can be speculated that Arabidopsis COX17 accumulates under stress conditions to actively replace damaged or inactive cytochrome c oxidase to sustain cyanide‐sensitive respiration in plant cells.
Operation and function of the tricarboxylic acid cycle in the illuminated leaf
Authors: Nunes‐Nesi Adriano , Sweetlove Lee J. , Fernie Alisdair R.
Published: November 2006

Respiratory activity of plants in the light, measured as carbon dioxide release from the tricarboxylic acid (TCA) cycle or oxygen consumption by the respiratory chain, is generally reported to lie between 25 and 100% of that in the dark. While this has been interpreted as evidence for an inhibition of respiration during photosynthesis, an increasing body of evidence indicates that mitochondrial respiration plays an important role in photosynthetic tissues. Historically, the view from experiments using specific respiratory inhibitors has been that oxidative phosphorylation in the mitochondria provides the cytosol with adenosine triphosphate even in the light. However, functioning of TCA cycle reactions is also required for the export of carbon skeletons necessary for nitrate reduction in the cytosol. In addition, export of TCA cycle‐derived reducing equivalents may also be necessary for photorespiration (for hydroxypyruvate reduction in the peroxisomes). The work with respiratory inhibitors has recently been complemented by a range of transgenic experiments that provide direct evidence for the importance of the TCA cycle in the illuminated leaves. These transgenesis experiments hint at an important role for ascorbate in coordinating the major pathways of energy metabolism within the leaf and are in keeping with current thinking that redox signals emanating from the mitochondria are important in setting the cellular machinery to maintain overall redox balance. In this review we intend to synthesize recent experimental data to postulate a model of the function of the TCA cycle in the illuminated leaf.
The mitochondrial type II peroxiredoxin from poplar
Authors: Gama Filipe , Keech Olivier , Eymery Françoise , Finkemeier Iris , Gelhaye Eric , Gardeström Per , Dietz Karl Josef , Rey Pascal , Jacquot Jean‐Pierre , Rouhier Nicolas
Published: November 2006

Mitochondria are a major site of reactive oxygen species production and controlling the peroxide levels in this compartment is essential. Peroxiredoxins (Prx) are heme‐free peroxidases, which use reactive cysteines for their catalysis and reducing systems for their regeneration. One of the two Prxs present in poplar mitochondria, Prx IIF, expressed as a recombinant protein, was found to reduce a broad range of peroxides with electrons provided preferentially by glutaredoxin and to a lesser extent by glutathione, all the thioredoxins tested being inefficient. This protein is constitutively expressed because it is found in all tissues analyzed. Its expression is modified during a biotic interaction between poplar and the rust fungus Melampsora laricii populina. On the other hand, Prx IIF expression does not substantially vary under abiotic stress conditions. Nevertheless, water deficit or chilling and probably induced senescence, but not photooxidative conditions or heavy metal treatment, also led to a small increase in PrxIIF abundance in Arabidopsis thaliana plants.
Nutrient digestibility of rabbit does in different stages of reproductive cycle under tropical conditions
Authors: Iyeghe‐Erakpotobor G. T. , Oyedipe E. O. , Eduvie L. O. , Ogwu D.
Published: November 2006

Effect of stages of reproductive cycle on body weight, feed intake and apparent nutrient digestibility of rabbits was investigated. Pregnant/lactating (PL) does increased their feed intake above pregnant lactating does. Dry matter (DM) digestibility was higher in pregnant does than in lactating, PL or open does. Digestibility of crude fibre, crude protein (CP) and nitrogen‐free extractives (NFE) were significantly higher for open and pregnant does than lactating and PL does. Ether extract (EE) digestibility was similar for pregnant, lactating and PL does. Digestible CP requirement of does increased with physiological state from open to PL states. Open and pregnant does were meeting their protein requirement while lactating and PL does were not meeting their requirement. Feed intake was higher for first week pregnant, fourth week pregnant, first week lactating, first week pregnant/fourth week lactating and second week pregnant/fourth week lactating does than open does. DM digestibility was higher for first and fourth week pregnant does than the other physiological stages. EE digestibility was similar for all physiological stages. CP digestibility was higher in fourth week pregnant does than the other physiological stages. Fourth week pregnant does had higher NFE digestibility than first and fourth week lactating and the various stages of concurrent pregnant and lactating does. Open does, first and fourth week pregnant does were meeting their protein requirement while does in the first and fourth week of lactating and stages of concurrent PL were not meeting their requirement.
In vivo metabolic effects of naringenin in the ethanol consuming rat and the effect of naringenin on adipocytes in vitro
Authors: Szkudelska K. , Nogowski L. , Nowicka E. , Szkudelski T.
Published: November 2006

Naringenin is a bioactive flavanone involved in the inhibition of drug metabolism which exhibits antioxidant, anti‐inflammatory and anticancerogenic properties and which recently appeared to be a factor mitigating the hyperlipidaemic effects in rats and rabbits. In the performed experiment, the effect of naringenin, administered intragastrically (50 mg/kg) for 2 weeks to normal and ethanol drinking rats, on insulin and leptin levels and on some metabolic parameters was investigated. Naringenin did not change the hormone levels in any group of rats. Blood glucose, triglyceride, total, esterified and free cholesterol and high‐density lipoprotein‐cholesterol concentrations were also unaffected by this compound. Only free fatty acids were elevated after the naringenin treatment in the water‐drinking rats. In spite of unchanged glucose and insulin concentrations in blood, the tested flavanone reduced the glucose/insulin ratio in ethanol‐receiving rats. Liver triglycerides, elevated due to ethanol ingestion, were partially normalized by naringenin. Other tested parameters like liver glycogen and cholesterol, muscle triglycerides and glycogen were not altered in any group of rats. The influence of naringenin (62.5, 125, 250 and 500 μm) on basal and insulin‐stimulated glucose conversion to lipids (lipogenesis) as well as on basal and epinephrine‐stimulated glycerol release (lipolysis) in the isolated rat adipocytes was also tested. The basal and the stimulated lipogenesis tended to be decreased in the presence of the flavanone (250 μm). This inhibitory effect intensified and was statistically significant at the highest concentration of naringenin. The tested compound did not evoke any effect on basal lipolysis while the epinephrine‐stimulated process was limited at the highest concentration of the flavanone. Naringenin (62.5, 125, 250 and 500 μm) had no effect on leptin secretion from the isolated rat adipocytes. Results obtained in our studies demonstrate that naringenin exerts a very weak influence on carbohydrate and lipid metabolism of normal and ethanol‐consuming rats and on metabolism of isolated rat adipocytes.
Concentration of copper, iron, manganese and zinc in muscle, fat and bone tissue of lambs of the breed German Merino Landsheep in the course of the growing period and different feeding intensities
Authors: Bellof G. , Most E. , Pallauf J.
Published: November 2006

A growth experiment with 108 lambs (breed German Merino Landsheep) was carried out in order to examine how gender, body weight and feeding intensity affect trace element concentrations in tissues and carcass. The lambs (50% male and 50% female) were fattened at three levels of feeding intensity (‘low’, ‘medium’ and ‘high’ by varying daily amounts of concentrate and hay) and slaughtered at different final body weights (30, 45 or 55 kg). Six male and six female animals were sacrificed at 18 kg live weight at the beginning of the comparative slaughter experiment. The left half carcass of each animal was divided into muscle tissue, fat tissue as well as bones and sinews and analysed for the trace elements copper (Cu), iron (Fe), manganese (Mn) as well as zinc (Zn). The body weight level influenced the Zn concentrations significantly in all tissues. In addition, the Fe concentration in the fat tissue was influenced by the body weight as well as the Cu content in the bone tissue. An influence due to gender could be seen for the Zn concentration in the muscle and fat tissue and for the Fe content in the fat and bone tissue as well as for the Cu concentration in the bones. The feeding intensity affected the Cu content in the muscle and bone tissue and also the Zn content in the muscle tissue. In the present study with lambs at body weight range from 18 to 55 kg on an average, 127 mg Fe, 87 mg Zn, 1.5 mg Cu as well as 1.1 mg Mn per kilogram dry matter were found in the bone tissue. In lamb muscle tissue combined from all parts (body weight range from 18 to 45 kg, both genders) the highest concentrations were for Zn and Fe [3.42 and 1.31 mg/100 g meat (wet weight basis)], while Cu remained far below these levels (0.08 mg/100 g meat and Mn was even below the detection limit of 0.025 mg/kg). Lamb muscle is a valuable source for highly available haem‐Fe as well as for Zn and Cu in human nutrition.
Effect of lactoferrin on selected immune system parameters and the gastrointestinal morphology in growing calves
Authors: Prgomet C. , Prenner M. L. , Schwarz F. J. , Pfaffl M. W.
Published: November 2006

Lactoferrin (LF) is a cationic iron‐binding glycoprotein that is abundantly expressed and secreted from glandular epithelial cells and a prominent component of the secondary granules of polymorphonuclear neutrophils. Variousin vitroandin vivoexperiments demonstrate anti‐microbial, ‐viral, ‐mycotic and ‐inflammatory effects of LF, associated with modulations of the immune system. Effects of oral administered LF on selected immune system parameters were studied in calves. Five calves were fed LF beginning on day 3 of life with colostral milk and starting on day 6 of life milk replacer enriched with 0.16 % LF was fed. The average daily intake of LF per calf was 1.5–1.6 g/day. Additional five calves served as control group with identical treatment except for the LF supplementation. At the end of the study (day 61 of life), all calves were slaughtered and various tissues were sampled for histological and gene‐expression studies. LF given orally was shown to act as an immunomodulatory agent by enhancing the size of Peyer's patches in the ileum and increasing blood serum immunoglobulin G levels. In addition, the number of peripheral blood leucocytes increased and mRNA levels of various interleukins (IL) such as IL‐1β, IL‐8, IL‐10 and interferon gamma (IFNγ) in those cells in response to LF treatment were enhanced. In blood, the mRNA expression of the pro‐inflammatory marker genes IL‐1βand IFNγdecreased over 10‐week treatment. Additionally, LF feeding decreased villus sizes in the jejunum. Together these findings emphasize the ability of LF to stimulate prominent immune system parameters and that it has the capacity to modulate the immune responses in a positive way.
CO‐alkene polymers are biocompatible scaffolds for primary urothelial cells in vitro and in vivo
Authors: Bartsch Georg C. , Malinova Violeta , Volkmer Bjoern E. , Hautmann Richard E. , Rieger Bernhard
Published: November 2006

OBJECTIVE

To investigate CO‐alkene polymers, novel synthetic nonbiodegradable polymers, as a potential biomaterial for urological applications.

MATERIALS AND METHODS

Porcine urothelial cells were seeded on cover glasses (96 wells; 10 000 cells/well) coated with CO‐alkene polymers [propylene/N‐Acetyl‐O′‐(hex‐5‐enyl)‐l‐tyrosine ethyl ester/CO (PTCO) and hexene‐CO (HxCO)]. The following conditions were investigated: cells seeded; (i) on PTCO, (ii) on HxCO, (iii) in PTCO‐conditioned medium, (iv) in HxCO‐conditioned medium, (v) on glass without polymers, (vi) on polystyrene, and (vii) on polystyrene treated with 1.25% NaCl (toxic control). Cell counts, cell death detection assay, and a cell activity assay (XTT, a tetrazolium‐based colorimetric assay) were performed after 3, 6 and 9 days. Urothelial‐cell seeded‐PTCO films (0.5 × 106 cells/cm2) were implanted into the subcutaneous space of athymic mice for up to 12 weeks and unseeded PTCO polymers were implanted as a negative control.

RESULTS

The urothelial cell adherence rates on the polymers were similar to those for glass and polystyrene. The cell activity (XTT assay) was higher in cells seeded on the polymers than in cells seeded on polystyrene and glass after 3 and 6 days. There were no significant differences between the apoptosis rates of all groups at the given sample times, except for the high levels in the toxic control. In vivo the urothelial cells survived on the polymers for 12 weeks with no adverse reactions in any of the mice.

CONCLUSIONS

CO‐alkene polymers are biocompatible materials for urothelial cells in vitro and in vivo, and thus are potential biomaterials for the urogenital tract.
The significance of the expression of dihydropyrimidine dehydrogenase in prostate cancer
Authors: Li Yongnan , Mizutani Yoichi , Shiraishi Takumi , Nakamura Terukazu , Mikami Kazuya , Takaha Natsuki , Okihara Koji , Kawauchi Akihiro , Sakai Toshiyuki , Miki Tsuneharu
Published: November 2006

OBJECTIVE

To measure dihydropyrimidine dehydrogenase (DPD), an enzyme involved in the metabolism of 5‐fluorouracil (5‐FU), expression in prostate cancer and determine whether 5‐chloro‐2,4‐dihydroxypyridine (CDHP), a potent inhibitor of DPD, enhances the antitumoral activity of 5‐FU against prostate cancer.

PATIENTS, MATERIALS AND METHODS

In all, 44 prostate tissue specimens were obtained from men who had a radical prostatectomy alone for prostate cancer, and 38 specimens from men who had had neoadjuvant hormonal therapy. We analysed the cancerous tissue and normal prostate tissue for DPD expression using immunohistochemistry, and determined its prognostic significance. In cultured human prostate cancer lines (DU145 and LNCaP), we compared the cytotoxicity of 5‐FU/CDHP with that of 5‐FU alone. Finally, in experiments on immunodeficient mice, we studied the effect of oral administration of tegafur, a pro‐drug for 5‐FU, with or without CDHP on the growth of tumours introduced by injection of DU145 cells.

RESULTS

The expression of DPD was significantly higher in cancerous than normal prostate tissue; 36 of 44 (82%) specimens of prostate cancer expressed DPD, whereas only 25 of 44 (57%) specimens of normal prostate tissue expressed DPD. For men with prostate cancer who had radical prostatectomy alone, men with negative DPD expression tended to have a longer recurrence‐free survival than those with positive expression; there were no recurrences in men with prostate cancer and negative DPD expression in the 5‐year follow‐up. DPD expression was significantly lower in men with prostate cancer who received neoadjuvant hormonal therapy. In vitro treatment of human prostate cancer cell lines with 5‐FU/CDHP showed more cytotoxicity than with 5‐FU treatment alone. Finally, DU145 tumours in mice treated with tegafur and CDHP were significantly smaller than in mice given tegafur alone.

CONCLUSION

The present study showed that DPD expression is elevated in prostate cancer, and indicate that DPD inhibitors might enhance the antitumour activity of 5‐FU against prostate cancer.
Urinary markers for prostate cancer
Authors: Downes Michelle R. , Byrne Jennifer C. , Pennington Stephen R. , Dunn Michael J. , Fitzpatrick John M. , Watson R. William G.
Published: November 2006

Prostate cancer is the commonest solid‐organ malignancy to affect men in Europe and the USA; it is estimated that one in six men will develop this cancer in their lifetime. Current screening relies on a digital rectal examination with a serum prostate‐specific antigen test. Novel urinary diagnostic tests are potentially interesting screening tools for this disease. We examined published reports assessing the use of urinary markers for the diagnosis of prostate cancer. Using a PubMed‐based search we identified studies of urinary markers for prostate cancer published from 1985 to February 2006 using the search terms ‘urine’, ‘marker’ and ‘prostate cancer’. Studies to date have used small cohorts and relied on prostatic biopsies to provide histology. The sensitivity and specificity of markers are wide ranging but with only a few studies published on each putative marker it is difficult to assess their potential impact. Using urinary biomarkers for prostate cancer is a relatively novel diagnostic approach; they are appealing as a screening test because they are not invasive. Further work is needed to identify and validate ‘signature markers’ indicative of prostatic malignancy. The newer proteomic platforms are promising biomarker discovery tools that might uncover the next generation of urinary biomarkers.
Ecological factors explaining the location of the boundary between the mixedwood and coniferous bioclimatic zones in the boreal biome of eastern North America
Authors: Messaoud Yassine , Bergeron Yves , Leduc Alain
Published: November 2006

Aim Climate is often regarded as the primary control determining the location of an ecotone between two vegetation zones. However, other ecological factors may also be important, especially when the northern limit of the dominant species of a vegetation zone extends further than the limit of the zone itself. This study aimed to identify the ecological variables explaining the transition between two zones within the boreal biome in Quebec (eastern Canada): the southern mixedwood forests dominated by balsam fir (Abies balsamea) and white birch (Betula papyrifera), and the northern coniferous forests dominated by black spruce (Picea mariana).

Location Quebec (eastern Canada).

Methods Data from 5023 sampling plots from the ecological inventory of the Québec Ministry of Natural Resources distributed throughout the two bioclimatic zones were used in logistic regressions to determine the relationships between the presence or absence of balsam fir stands and different abiotic and biotic variables, at both stand and landscape scales.

Results The presence of balsam fir stands was negatively related to the thick organic horizons, coarse xeric deposits and low positions on the slope, whereas stands were favoured by high elevations, steep slopes and moderate drainage. These results defined the suitable conditions for the development of balsam fir stands. In the coniferous zone these suitable conditions were less abundant. Furthermore, the saturation level of suitable sites was lower, as well as the incidence of balsam fir stands in unsuitable sites (overflow). Balsam fir stands were mostly located near lakes and rivers. All significant variables at both the stand and landscape scales explained between 34 and 42% of the location of the potential northern distribution limit of the mixedwood zone.

Main conclusions Our results suggest the important role of historical factors related to post‐glacial vegetation and past disturbances in determining the relative abundance of balsam fir in both zones of the boreal biome.
A Test of Objectification Theory with Lesbian Women
Authors: Kozee Holly B. , Tylka Tracy L.
Published: November 2006

This study extends research on objectification theory as it applies to eating disorder symptomatology by examining whether its tenets generalize to women identifying as lesbian. Lesbian women ( N = 181) and a comparison sample of heterosexual women ( N = 196) completed measures of objectification theory constructs (interpersonal sexual objectification, body surveillance, body shame, interoceptive awareness, disordered eating). The model of objectification theory was tested separately for lesbian and heterosexual participants. Path analyses revealed that this model provided a poor fit to the data for the lesbian sample, whereas it provided an excellent fit to the data for the heterosexual sample. Based on the data from the lesbian participants, an exploratory model was evaluated. Overall, findings suggested that the interrelationships among the objectification theory constructs were different and more complex for the lesbian participants than for the heterosexual participants.
The endothelin‐1 receptor‐mediated pathway is not involved in the endothelin‐1‐induced defenestration of liver sinusoidal endothelial cells
Authors: Yokomori Hiroaki , Yoshimura Kazunori , Ohshima Susumu , Nagai Toshihiro , Fujimaki Kayo , Nomura Masahiko , Oda Masaya , Hibi Toshifumi
Published: November 2006

Abstract: Background/Aims: We previously reported that endothelin (ET)‐1 may be involved in the contraction of hepatic sinusoidal endothelial fenestrae (SEF). Rho has emerged as an important regulator of the actin cytoskeleton and consequently cell morphology. To clarify the role of ET receptors [endothelin A receptor (ETAR) and endothelin B receptor (ETBR)] in ET‐1‐induced defenestration, we studied the size of hepatic SEF under various experimental conditions.

Methods: Liver sinusoidal endothelial cells (LSECs) isolated from rat livers by collagenase perfusion were cultured and divided into four groups: control, ET‐1 (10−6–10−10 M)‐treated, ET‐1+selective ETAR antagonist (BQ610)‐treated and ET‐1+ETBR antagonist (BQ788)‐treated groups. SEF morphology was observed by scanning electron microscopy. Protein expressions of ETAR and ETBR, Rho A and phosphorylated myosin light‐chain kinase were analyzed by Western blotting. F‐actin stress fiber formation was observed by confocal microscopy. Active Rho was measured by Ren's modification. Intracellular free Ca2+ concentration ([Ca2+]i) was measured by fluorescence digital imaging using fura‐2 AM by Aqua cosmos.

Results: ET‐1 induced a reduction in the number and size of SEF. ETAR antagonist pretreatment inhibited defenestration induced by low ET‐1 concentrations (10−8–10−10 M), whereas ETBR antagonist pretreatment did not block defenestration at low to high ET‐1 concentrations (10−6–10−10 M). F‐actin stress fibers, Rho A levels and phosphorylated myosin light‐chain kinase levels remained the same in various treatments. Active Rho was not detected in control and various treatments. ET‐1 did not increase [Ca2+]i. Western blot showed prominent ETBR but scarce ETAR protein expression in LSECs.

Conclusions: The present findings demonstrated that ETBR‐ and ETAR‐induced contractile mechanisms are not involved in ET‐1‐induced defenestration, and that Rho is also not activated. Therefore, ET‐1 induces hepatic defenestration by mechanisms other than receptor‐mediated contraction.
Partnerships for Learning Population‐Based Public Health Nursing: Web‐Delivered Continuing Education for Public Health Nurse Preceptors
Authors: Zahner Susan J.
Published: November 2006

ABSTRACT
Public health and other community health nurses frequently serve as preceptors to undergraduate student nurses learning population‐based nursing in community/public health practicum courses. The extent of preparation and support for the preceptor role provided by schools of nursing is often limited. One strategy to address this problem is to provide targeted, Web‐delivered continuing education (CE) to preceptors. A Web‐delivered CE course entitled, “Partnerships for Learning Community Health Nursing,” was created and pilot tested. Course content includes preceptor roles; assisting students in learning population‐based public health nursing, critical thinking, and cultural competence; learning styles and teaching strategies; what to do in challenging situations; evaluation and feedback; and specific information about school policies, procedures, and course assignments. Precourse knowledge was assessed using a mailed survey. Postcourse knowledge and satisfaction were assessed using questions embedded in the course. Postsemester knowledge and satisfaction were evaluated through a postsemester survey. Knowledge gain was tested using repeated measures ANOVA and paired t tests. Thirteen preceptors participated in the pilot test. Repeated measures ANOVA indicated that knowledge gain occurred (multivariate F=55.603, df=2, error df=11, p<.0001). Participants increased knowledge from pretest to posttest (t=−10.25, p<.00001) and from pretest to end of the semester (t=−4.95, p<.0003). Knowledge decline from end of course to end of semester was not significant (t=1.94, p=.08). Participants reported satisfaction with the course. Web‐delivered CE for community/public health nurse preceptors can support preceptor learning and is an acceptable method for receiving this type of education. Further research is needed on the impact of preceptor education on student learning.
Deterioration
Authors: Brown Stephen
Published: November 2006

Summary:  Intellectual deterioration in epilepsy may be real or apparent. The latter refers to delay in cognitive development such that performance against age‐related norms appears to drop. The former, real deterioration can occur due to concomitant degenerative neurological disease of which epilepsy is also a symptom, or it may happen as a consequence of one or more of a number of other factors. These include (1) direct effects of seizures and abnormal electroencephalogram activity on brain function, (2) traumatic brain injury secondary to seizures, including status epilepticus, (3) the influence of antiepileptic therapy, both drugs and surgery, on cognitive function, (4) psychosocial sequelae of diagnosis. Some epilepsy syndromes include intellectual deterioration as a frequent feature, with various causes. Developmental factors may also play a part. Cognitive functioning may be impaired by the presence of an epileptogenic lesion, and also in different ways and at different times by other brain areas involved with partial seizures, including irritative and functional deficit zones. Abnormal activity in these areas at critical periods in development may interact and disrupt pathways necessary for maturation of frontal lobe and limbic system functioning, leading to long‐term neurological deficits. Increased understanding of the mechanisms by which this may happen raises intriguing possibilities for prevention and remediation.