bluuebunny/crossref_metadata_2025 huggingface dataset:
Elevated CO2 does not ameliorate effects of ozone on carbon allocation in Pinus halepensis and Betula pendula in symbiosis with Paxillus involutus
Authors: Kytöviita M.‐M. , Pelloux J. , Fontaine V. , Botton B. , Dizengremel P.
Published: March 2003

The effect of 700 μmol CO2 mol−1, 200 nmol ozone mol−1 and a combination of the two on carbon allocation was examined in Pinus halepensis co‐cultured with Betula pendula in symbiosis with the ectomycorrhizal fungus Paxillus involutus. The results show that under low nutrient and ozone levels, elevated CO2 has no effect on the growth of B. pendula or P. halepensis seedlings nor on net carbon partitioning between plant parts. Elevated CO2 did not enhance the growth of the fungus in symbiosis with the birch. On the other hand, ozone had a strong negative effect on the growth of the birch, which corresponded with the significantly reduced growth rates of the fungus. Exposure to elevated CO2 did not ameliorate the negative effects of ozone on birch; in contrast, it acted as an additional stress factor. Neither ozone nor CO2 had significant effects on biomass accumulation in the pine seedlings. Ozone stimulated the spread of mycorrhizal infection from the birch seedlings to neighbouring pines and had no statistically significant effects on phosphoenolpyruvate carboxylase (PEPC) or ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) activity in the pine needles or on PEPC activity in pine roots.
Differential response of antioxidant compounds to salinity stress in salt‐tolerant and salt‐sensitive seedlings of foxtail millet (Setaria italica)
Authors: Sreenivasulu N. , Grimm B. , Wobus U. , Weschke W.
Published: March 2003

The modulation of antioxidant components was comparatively analysed in a salt‐tolerant (cv. Prasad) and salt‐sensitive (cv. Lepakshi) cultivar of foxtail millet (Setaria italica L.) under different NaCl concentrations. Under conditions of salt stress, the salt‐tolerant cultivar exhibited increased total superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity, whereas both enzyme activities decreased in acutely salt‐stressed seedlings of the sensitive cultivar. At 200 mM NaCl, the tolerant foxtail millet cultivar responded with induction of cytosolic Cu/Zn‐SOD and the Mn‐SOD isoform at the protein level. The induced accumulation of the cytosolic Cu/Zn‐SOD protein/activity is positively correlated with an elevated level of the cytosolic APX gene activity. The elevated cytosolic Cu/Zn‐SOD and cytosolic APX activity correlates with an induced accumulation of their transcripts. Tolerant 5‐day‐old seedlings grown during high salinity treatment (200 mM NaCl) contained a lower amount of Na+ ions and showed a lower electrolyte leakage than sensitive seedlings. In conclusion, our comparative studies indicate that salt‐induced oxidative tolerance is conferred by an enhanced compartment‐specific activity of the antioxidant enzymes in response to compartment‐specific signals.
Carotenogenesis in the green alga Haematococcus pluvialis: Cellular physiology and stress response
Authors: Boussiba S.
Published: March 2003

The unicellular green alga Haematococcus pluvialis Flotow has recently aroused considerable interest due to its capacity to amass large amounts of the ketocarotenoid astaxanthin (3,3′‐dihydroxy‐β,β‐carotene‐4,4′‐dione), widely used commercially to color flesh of salmon. Astaxanthin accumulation in Haematococcus is induced by a variety of environmental stresses which limit cell growth in the presence of light. This is accompanied by a remarkable morphological and biochemical ‘transformation’ from green motile cells into inert red cysts. In recent years we have studied this transformation process from several aspects: defining conditions governing pigment accumulation, working out the biosynthetic pathway of astaxanthin accumulation and questioning the possible function of this secondary ketocarotenoid in protecting Haematococcus cells against oxidative damage. Our results suggest that astaxanthin synthesis proceeds via cantaxanthin and that this exceptional stress response is mediated by reactive oxygen species (ROS) through a mechanism which is not yet understood. The results do not support in vivo chemical quenching of ROS by the pigment, although in vitro it was shown to quench radicals very efficiently. The finding that most of the pigment produced is esterified and deposited in lipid globules outside the chloroplast further supports this assumption. We have suggested that astaxanthin is the by‐product of a defense mechanism rather than the defending substance itself, although at this stage one cannot rule out other protective mechanisms. Further work is required for complete understanding of this transformation process. It is suggested that Haematococcus may serve as a simple model system to study response to oxidative stress and mechanisms evolved to cope with this harmful situation.
Identification of a putative Solanum tuberosum transcriptional coactivator up‐regulated in potato tubers by Fusarium solani f. sp. eumartii infection and wounding
Authors: Godoy Andrea V. , Zanetti María Eugenia , San Segundo Blanca , Casalongué Claudia A.
Published: March 2003

Coadaptors or coactivators are a new class of transcription factors capable of interconnecting a regulator DNA‐binding protein with a component of the basal transcription machinery allowing transcriptional activation to proceed. We report the identification of a novel Solanum tuberosum ssp. tuberosum putative transcription coactivator, named StMBF1 (Solanumtuberosummultiprotein bridging factor 1). The StMBF1 cDNA was isolated from a Fusarium solani f. sp. eumartii‐infected potato tuber cDNA library, using a differential screening approach. StMBF1 is up‐regulated during fungal attack as well as on wounding. A Fusarium elicitor source and ethylene precursor and salicylic acid also regulate StMBF1 expression. The precise role of StMBF1 during the plant response against environmental stresses remains to be elucidated.
Silicification in sorghum (Sorghum bicolor) cultivars with different drought tolerance
Authors: Lux Alexander , Luxová Miroslava , Hattori Taiichiro , Inanaga Shinobu , Sugimoto Yukihiro
Published: March 2003

Sorghum belongs to a group of economically important, silicon accumulating plants. X‐ray microanalysis coupled with environmental scanning electron microscopy (ESEM) of fresh root endodermal and leaf epidermal samples confirms histological and cultivar specificity of silicification. In sorghum roots, silicon is accumulated mostly in endodermal cells. Specialized silica aggregates are formed predominantly in a single row in the form of wall outgrowths on the inner tangential endodermal walls. The density of silica aggregates per square mm of inner tangential endodermal cell wall is around 2700 and there is no significant difference in the cultivars with different content of silicon in roots. In the leaf epidermis, silicon deposits were present in the outer walls of all cells, with the highest concentration in specialized idioblasts termed ‘silica cells’. These cells are dumb‐bell shaped in sorghum. In both the root endodermis and leaf epidermis, silicification was higher in a drought tolerant cultivar Gadambalia compared with drought sensitive cultivar Tabat. Silicon content per dry mass was higher in leaves than in roots in both cultivars. The values for cv. Gadambalia in roots and leaves are 3.5 and 4.1% Si, respectively, and for cv. Tabat 2.2 and 3.3%. However, based on X‐ray microanalysis the amount of Si deposited in endodermal cell walls in drought tolerant cultivar (unlike the drought susceptible cultivar) is higher than that deposited in the leaf epidermis. The high root endodermal silicification might be related to a higher drought resistance.
Nitrogen‐assimilating enzymes in land plants and algae: phylogenic and physiological perspectives
Authors: Inokuchi Ritsuko , Kuma Kei‐ichi , Miyata Takashi , Okada Mitsumasa
Published: March 2003

An important biochemical feature of autotrophs, land plants and algae, is their incorporation of inorganic nitrogen, nitrate and ammonium, into the carbon skeleton. Nitrate and ammonium are converted into glutamine and glutamate to produce organic nitrogen compounds, for example proteins and nucleic acids. Ammonium is not only a preferred nitrogen source but also a key metabolite, situated at the junction between carbon metabolism and nitrogen assimilation, because nitrogen compounds can choose an alternative pathway according to the stages of their growth and environmental conditions. The enzymes involved in the reactions are nitrate reductase (EC 1.6.6.1‐2), nitrite reductase (EC 1.7.7.1), glutamine synthetase (EC 6.3.1.2), glutamate synthase (EC 1.4.1.13‐14, 1.4.7.1), glutamate dehydrogenase (EC 1.4.1.2‐4), aspartate aminotransferase (EC 2.6.1.1), asparagine synthase (EC 6.3.5.4), and phosphoenolpyruvate carboxylase (EC 4.1.1.31). Many of these enzymes exist in multiple forms in different subcellular compartments within different organs and tissues, and play sometimes overlapping and sometimes distinctive roles. Here, we summarize the biochemical characteristics and the physiological roles of these enzymes. We also analyse the molecular evolution of glutamine synthetase, glutamate synthase and glutamate dehydrogenase, and discuss the evolutionary relationships of these three enzymes.
Molecular biology of plant laccases in relation to lignin formation
Authors: Gavnholt Britta , Larsen Knud
Published: March 2003

The lack of monocot laccase sequence data has been held as an argument against laccases playing a role in lignin polymerization. This overview focuses on plant laccase molecular biology in relation to lignin formation with emphasis on recently cloned monocot laccases from ryegrass (Lolium perenne). Laccase is found within the major seed plant groupings. Furthermore, as laccases have probably been duplicated before and after division into monocots, dicots and gymnosperms, it is hypothesized that all higher plants encode a multitude of laccases. Work published during the past decade indicates the existence of a strong relationship between laccase expression and lignification in several plant species. Likewise, analysis of the first plant laccase promoter shows that this laccase is putatively regulated by a group of transcription factors that have been shown to regulate several enzymes of the phenylpropanoid pathway. It is suggested that laccases may also serve other roles than participation in lignin formation in plant biology.
Changes in ethylene responsiveness of senescence‐related genes during carnation flower development
Authors: Verlinden Sven , Boatright Jennifer , Woodson William R.
Published: March 2003

Changes in ethylene responsiveness of senescence‐related (SR) genes in carnation (Dianthus caryophyllus cv. White Sim) petals were investigated during flower development. Dose‐response and time‐response analysis of SR gene expression indicate that SR genes can be divided into two groups according to their response to ethylene. The ethylene biosynthetic genes, ACC synthase and ACC oxidase represent one group. They show a marked delay of 6 and 9 h in mRNA accumulation in response to ethylene and their apparent dissociation constants of the response (Kr) at open flower stage of development are 17.20 and 1.76 µl l−1, respectively. The second group of ethylene responsive genes contains SR5, SR8, SR12, and DCCP. These genes show an almost immediate accumulation of their respective mRNAs in response to ethylene and have Krs at open flower stage of development of 0.08, 0.46, 0.25, and 0.05 µl l−1, respectively. All SR genes, including the ethylene biosynthetic genes, show increases in responsiveness to ethylene as measured by the accumulation of their respective transcripts during flower development. A model of ethylene signal transduction in carnation petals and flower senescence is presented taking into account these observations.
Polyamine pattern during flower development in the parthenocarpic fruit (pat) mutant of tomato
Authors: Antognoni Fabiana , Ghetti Francesca , Mazzucato Andrea , Franceschetti Marina , Bagni Nello
Published: March 2003

Polyamine (PA) pattern was investigated in floral organs of Lycopersicon esculentum Mill. plants at four developmental stages from floral bud until 2 days after anthesis. Differences in putrescine (put), spermidine (spd) and spermine (spm) content, both free and conjugated, were evaluated in a control line (WT) and in the parthenocarpic fruit (pat) mutant. PA content turned out to be quite similar in WT and pat mutant ovaries, but the two lines showed a different PA pattern throughout flower development. A net accumulation of PAs, in particular spd and spm, was observed in concomitance with pre‐anthesis floral stages in pat mutant ovaries, while in control plants the PA pattern did not change significantly during the developmental stages considered. These differences seem to be strictly related to the physiological events that initiate ovary development, which have been shown to be precocious in the mutant ovaries and occurring at pre‐anthesis stages. The number of pericarp cell layers indeed increase in parthenocarpic ovaries at the stage of flower opening, and mitotic activity was followed by cell extension, as demonstrated by the increase in pericarp cell diameter. A decrease in free PA levels and an increase in the conjugated pool were associated with the initiation of cell expansion. The pattern of ornithine decarboxylase (ODC; EC 4.1.1.17), arginine decarboxylase (ADC; EC 4.1.1.19) and S‐adenosylmethionine decarboxylase (SAMDC; EC 4.1.1.1) gene expression, as well as the respective enzyme activities, were also analysed during development. The lack of correlation between transcript levels and enzyme activity suggests that post‐transcriptional control mechanisms must be acting in the regulation of biosynthetic genes.
Response of selected antioxidants and pigments in tissues of Rosa hybrida and Fuchsia hybrida to supplemental UV‐A exposure
Authors: Helsper Johannes P. F. G. , Ric de Vos C. H. , Maas Frank M. , Jonker Harry H. , Van Den Broeck Hetty C. , Jordi Wilco , Pot C. Sander , Keizer L. C. Paul , Schapendonk Ad H. C. M.
Published: March 2003

The effect of supplemental UV‐A (320–400 nm) radiation on tissue absorption at 355 nm, levels of various antioxidants (ascorbate, glutathione, carotenoids and flavonoids) and of antioxidant scavenging capacity were investigated with leaves and petals of Rosa hybrida, cv. Honesty and with leaves, petals and sepals of Fuchsia hybrida, cv. Dollarprinzessin. Supplemental UV‐A did not result in visible changes in plant morphology of either species. In leaves it induced small increases in levels of chlorophylls a and b, the carotenoids antheraxanthin, lutein and β‐carotene, and high increases in the flavonols quercetin and kaempferol. Petals hardly responded, while the coloured sepals of fuchsia showed an increase in quercetin derivatives. HPLC of unhydrolysed flavonoids showed that individual quercetin derivatives in leaves of both species and kaempferol derivatives in rose leaves increased 2‐fold. Some kaempferol derivatives in fuchsia leaves were more than 2‐fold enhanced or were newly induced by supplemental UV‐A. Increases in l‐ascorbic acid levels in fuchsia leaves, and decreases in rose leaves as result of supplemental UV‐A were observed, but differences appeared statistically not significant, while l‐ascorbate levels remained unchanged in the other tissues investigated. Anthocyanins and reduced glutathione levels were unaffected in all tissues. The combined UV‐A induced increases in concentrations of these antioxidant species, did not lead to significant increases in antioxidant capacity of tissues, measured as Trolox equivalents in 50%‐ethanol extracts. Light absorption at 355 nm of leaf extracts was significantly increased upon UV‐A exposure. Our results indicate that the major protection towards UV‐A exposure, in particular in the leaves, will originate from absorption of irradiation, and not from scavenging reactive oxygen species.
Approaches to fungal diagnosis in transplantation
Authors: Patterson T.F.
Published: March 2003

The diagnosis of invasive fungal infection in patients undergoing solid organ or bone marrow transplantation remains a significant clinical challenge. Consideration of the epidemiology of these infections and host risk factors may be an important clue to a specific fungal diagnosis. Despite extensive investigation on methods such as serologic techniques to improve the rapid diagnosis of these infections, the diagnosis of invasive mycoses remains largely dependent on clinical presentation. For example, the signs and symptoms that result from angioinvasion of fungal organisms include pleuritic chest pain or hemoptysis. In a high‐risk patient these findings can be important clues to invasive fungal infection. Cultures of opportunistic fungi in certain settings, such as Aspergillus in respiratory samples from immunosuppressed patients, may be associated with infection. Radiographic findings can also be useful to establish a diagnosis of infection. In patients with invasive aspergillosis as well as other angioinvasive moulds, chest CT scans may demonstrate lesions that are not visible on plain radiographs. Serodiagnosis of these infections remains largely investigational. Microbiological antifungal resistance has increasingly been reported, but in patients at high risk for serious fungal infection, including patients undergoing bone marrow and organ transplantation, antifungal resistance remains uncommon, particularly in Candida albicans. Higher doses of azoles should be used to treat patients with infections due to less susceptible yeasts and those with more serious infection. Prompt recognition of fungal infection combined with intensive antifungal therapy is needed for successful therapy.
Immunosuppression without immunosuppression? How to be a tolerant individual in a dangerous world
Authors: Kirk A.D.
Published: March 2003

The field of transplantation has developed based on two principles: allografts are rejected because they express foreign antigens, and the immune system must be suppressed to prevent rejection. Recently, in vitro and in vivo experimental evidence has accumulated that calls both of these beliefs into question. This article reviews an alternative approach to transplantation that focuses on tissue injury as the instigator of graft rejection and employs physiological mechanisms of tolerance to avoid graft loss. Methods that allow for defense against infectious microbes while at the same time allowing for graft survival are proposed. In particular, the rationale behind the use of anti‐CD154 antibody treatment is highlighted. A model is introduced that takes into consideration the experimental successes seen with anti‐CD154 therapies
1.
Lack of variation in αgal expression on lymphocytes in miniature swine of different genotypes
Authors: Chae Sanders J. , Kramer Aaron D. , Zhao Yong , Arn Scott , Cooper David K. C. , Sachs David H.
Published: March 2003

Chae S.J., Kramer A.D., Zhao Y., Arn S., Cooper D.K.C., Sachs D.H. Lack of variation in αGal expression on lymphocytes in miniature swine of different genotypes. Xenotransplantation 1999; 6: 00‐00. ©Munksgaard, Copenhagen

Abstract: Background: Galα1–3Gal epitopes (αGal) have been demonstrated to be present on tissues of all pig breeds tested to‐date and are the major target for human antiαgalactosyl (αGal) antibodies. We investigated members of an MHC‐inbred miniature swine herd to assess whether there was an association between genotype and expression of αGal. Identification of a low expressor genotype would potentially enable selective breeding of pigs that might prove beneficial as donors in clinical xenotransplantation. Methods: we measured αGal expression on various pig cells by use of fluorescent ‐activated cell sorter (FACS) using (i) purified human antiαGal antibody and (ii) the isolectin GS‐I‐B4. Initial studies were on porcine peripheral blood mononuclear cells (PBMCs) and subsequent studies on, lymphocytes, platelets, and T cell subsets (CD4 + and CD8 + cells). Results: there was considerable day‐to‐day variation in αGal expression on PBMCs from the same pig. When only lymphocytes were examined, there was a high degree of reproductibility, and no significant difference in αGal expression was detected between representative pairs of animlas of three different genotypes. Purified anti‐αGal antibody bound to different sites on the αGal epitope than did the Griffonia (Bandeiraea) simplicifolia I‐B4 (GS‐I‐B4). Lectin binding was significantly reduced in the absence of divalent cations. When CD4 + and CD8 + T cells were examined for αGal expression, two distinct populations of each type of cell were observed, with larger cells expressing a higher level of αGal. Conclusions: although the number of pigs of different genotypes studied was small, on the basis of this limited study pigs, of a low αGal expressor genotype that could be selectively bred for use in clinical xenotransplantation were not identified.
Impact of immunoadsorption on xenogeneic extracorporeal pig liver perfusion: assessment of organ function during autologous reperfusion
Authors: Kornberg A. , Dietz O. , Mau H. , Pascher A. , Stangl M. , Scheele J. , Hammer C.
Published: March 2003

The shortage of liver grafts has resulted in an intensive search for alternative strategies of liver support in acute liver failure. Extracorporeal perfusion of pig livers (ECLP) is not a new concept, but recent improvements in cardiopulmonary bypass technology and new knowledge about xenogeneic immunologic mechanisms have made it a potential therapeutic modality. In previous suboptimal experimental and clinical models, no statements about the beneficial effect of long‐lasting periods of ECLP were made. The aim of this study was to evaluate the capacity of pig liver for metabolic regeneration after xenogeneic ECLP under largely physiologic conditions. To delay hyperacute rejection (HAR), we utilized immunoadsorption (IA) of naturally preformed xenogeneic antibodies (XNAbs). This led to a stable xenogeneic ECLP for 45 min. However, IA was not able to prevent completely organ damage or loss of function resulting from insufficient autologous reperfusion. The inability to regenerate during autologous reperfusion provides a new measure of the function of a xenogeneic perfused pig liver. In addition, our results implicate that patients with fulminant liver failure will benefit from short perfusions with several fresh organs rather than from long perfusion with a single pig liver.
The problem of anti‐pig antibodies in pig‐to‐primate xenografting: current and novel methods of depletion and/or suppression of production of anti‐pig antibodies
Authors: Alwayn Ian P. J. , Basker Murali , Buhler Leo , Cooper David K. C.
Published: March 2003

The role of antibodies directed against Galα1–3Gal (α‐Gal) epitopes in porcine‐to‐primate xenotransplantation has been widely studied during the past few years. These antibodies (anti‐α‐Gal) have been associated with both hyperacute rejection and acute vascular rejection of vascularized organs. Depletion and (temporary or permanent) suppression of production of anti‐α‐Gal seem to be essential to the long‐term survival of these organs, even when the ultimate aim is accommodation or tolerance. Although more than 95% depletion of anti‐α‐Gal can be achieved by the use of immunoaffinity column technology, to date no regimen has been successful in preventing the return of anti‐α‐Gal from continuing production. In this review, we discuss current and novel methods for achieving depletion or inhibition (i.e. extracorporeal immunoadsorption, anti‐idiotypic antibodies, the intravenous infusion of immunoglobulin or oligosaccharides) and suppression of production (i.e. irradiation, pharmacologic agents, specific monoclonal antibodies, immunotoxins) of anti‐α‐Gal antibodies.
Trade‐offs, condition dependence and stopover site selection by migrating sandpipers
Authors: Ydenberg Ronald C. , Butler Robert W. , Lank David B. , Guglielmo Christopher G. , Lemon Moira , Wolf Nicholas
Published: March 2003

Western sandpipersCalidris maurion southward migration fly over the Gulf of Alaska to the Strait of Georgia, British Columbia, where they stop for a few days to replenish reserves before continuing. In the Strait, individuals captured on the extensive tidal mudflats of the Fraser estuary (∼25000 ha) are significantly heavier (2.71 g, or >10% of lean body mass) than those captured on the small (<100 ha) mudflat of nearby Sidney Island. Previous work has shown that the difference cannot be attributed to seasonal timing, size, age or gender effects, and here we compare predictions made by six hypotheses about a diverse set of data to explain why, partway through a migratory journey of ∼10000 km, birds have such different body masses at two stopover sites within 40 km of each other. The ‘trade‐off’ hypothesis – that the large Fraser estuary offers safety from predators, but a lower fattening rate, while the small Sidney Island site is more dangerous, but offers a higher fattening rate – made six successful predictions, all of which were upheld by the data. All other hypotheses failed at least one prediction. We infer that calidrid sandpipers arriving in the Strait of Georgia with little fat remaining (and therefore low body mass) choose to take advantage of the high feeding rate at small sites like Sidney Island because they are less vulnerable to avian predators than are individuals with higher fat reserves, who instead elect to feed at large open sites like the Fraser estuary mudflats.
Type 1 T regulatory cells
Authors: Roncarolo Maria Grazia , Bacchetta Rosa , Bordignon Claudio , Narula Satwant , Levings Megan K.
Published: March 2003

Summary: Suppression by T regulatory (Tr) cells is essential for induction of tolerance. Many types of Tr cells have been described in a number of systems, and their biology has been the subject of intensive investigation. Although many aspects of the mechanisms by which these cells exert their effects remain to be elucidated, it is well established that Tr cells suppress immune responses via cell‐to‐cell interactions and/or the production of interleukin (IL)‐10 and transforming growth factor (TGF)‐β. Type‐1 T regulatory (Tr1) cells are defined by their ability to produce high levels of IL‐10 and TGF‐β. Tr1 cells specific for a variety of antigens arise in vivo, but may also differentiate from naive CD4+ T cells in the presence of IL‐10 in vitro. Tr1 cells have a low proliferative capacity, which can be overcome by IL‐15. Tr1 cells suppress naive and memory T helper type 1 or 2 responses via production of IL‐10 and TGF‐β. Further characterisation of Tr1 cells at the molecular level will define their mechanisms of action and clarify their relationship with other subsets of Tr cells. The use of Tr1 cells to identify novel targets for the development of new therapeutic agents, and as a cellular therapy to modulate peripheral tolerance, can be foreseen.
A novel human homolog of eosinophil major basic protein
Authors: Plager Douglas A. , Adolphson Cheryl R. , Gleich Gerald J.
Published: March 2003

Summary: Eosinophil major basic protein (MBP) contributes to host defense and disease pathophysiology. Chromosome 11 contains the genes for human MBP1 (hMBP1) and a second novel MBP, hMBP2, in the centromere to 11q12 region. Interestingly, greater similarity exists between human and murine MBP1 and MBP2 orthologs, respectively, than between hMBP1 and hMBP2, suggesting a gene duplication event prior to the divergence of humans and mice. There is abundant mRNA for hMBP1 in both bone marrow (eosinophils and basophils) and placenta, but hMBP2 mRNA is present only in bone marrow (eosinophils). Comparison of proximal promoters for hMBP2, hMBP1, and murine MBP1 (mMBP1) shows a conserved GATA transcription factor binding site (functionally active in hMBP1). However, whether a C/EBP binding site common to hMBP1 and mMBP1 is functionally conserved in hMBP2 remains unresolved. Similarly, the role of conserved putative IK2 and STAT binding sites in MBP transcriptional control remains unknown. Like hMBP1, hMBP2 is in the eosinophil secondary granule. However, hMBP2 is twofold less positively charged than hMBP1 (+8 versus +16 at neutral pH), and this difference may explain hMBP2's similar, but often less potent, in vitro biological activities. Overall, while conservation of hMBP2's amino acid sequence (63% identity with hMBP1) suggests a common function(s) with hMBP1, hMBP2's substantially reduced charge and the existence of the similar mMBP2 argue for additional, unique functions for hMBP2.

This work was supported in part by grants from the National Institutes of Health, AI 34577 and AI 09728 (GJG), and by the Mayo Foundation.
Incomplete septal cirrhosis associated with Wegener's granulomatosis
Authors: Zen Yoh , Sunagozaka Hajime , Tsuneyama Koichi , Masutomi Kekichi , Terasaki Shuichi , Kaneko Shuichi , Kobayashi Kenichi , Nakanuma Yasuni
Published: March 2003

Abstract: Incomplete septal cirrhosis, which is included in the spectrum of hepatoportal sclerosis, is characterized by parenchymal nodularity, incomplete fibrous septa, clustered or dispersed portal tract remnants, and abnormal spacing of portal tracts and hepatic veins. Hepatoportal sclerosis is known to be associated with collagen vascular diseases. Here, we describe a 73 year‐old‐female with incomplete septal cirrhosis. At 57 years, she presented with respiratory symptoms, and lung biopsy disclosed active arteritis with granuloma. Perinuclear antineutrophilic cytoplasmic antibody was also positive. Immunosuppressive therapy was done under the diagnosis of Wegener's granulomatosis. At 63 years, liver dysfunction was noted, and laparoscopy revealed uneven surface of the liver and dilatation of the umbilical vein. Liver dysfunction progressed, and she developed encephalopathy and massive ascites. She died of sepsis at 73 years. At autopsy the liver (700 g) was macronodular with several deep depressions. The parenchyma showed fine and diffuse nodularity. Grossly visible portal and hepatic veins were patent. The above‐mentioned histologic features characterizing incomplete septal cirrhosis were @found. This is the first report of incomplete septal cirrhosis associated with Wegener's granulomatosis implying that vascular and extravascular lesions of Wegener's granulomatosis might have been related to the pathogenesis of incomplete septal cirrhosis.
Cell proliferation and renewal of normal hepatocytes and bile duct cells in adult mouse liver
Authors: Magami Yasushi , Azuma Takeshi , Inokuchi Hideto , Kokuno Shinichiro , Moriyasu Fuminori , Kawai Keiichi , Hattori Takanori
Published: March 2003

Abstract: Background/Aims: The source of new cells in the normal adult liver has been controversial. Some investigators have hypothesized the streaming liver model. On the other hand, others reject this hypothesis. We examined hepatic cell kinetics by a special labeling method with [3H]thymidine.

Methods: ICR mice received 112 repeated injections of [3H]thymidine at 6 h intervals for 28 days after birth and were killed immediately thereafter, or 100, 200 or 300 days after the last injection. Immediately after killing the animals, samples of the liver were taken and autoradiography was performed.

Results: After continuous labeling, more than 90% of the cells in the liver were labeled. Mean grain counts of hepatocytes decreased to half over approximately 100 days. Those of bile duct cells decreased at a slower rate (50%) than hepatocytes. Mean grain counts of hepatocytes decreased over the regions, although those in perivenular region decreased more rapidly in comparison to those in periportal region.

Conclusions: The present study indicated that most cells in the liver arise postnatally. The changes in labeling of cells show that there is no special zone for proliferation of hepatocytes and they renew in all regions of the hepatic lobule, suggesting (i) that hepatocytes are supplied by postnatal replication and (ii) streaming of hepatocytes from periportal to pericentral regions does not occur in the adult mouse liver. The bile duct cells renewed more rapidly than hepatocytes.
Effects of intestinal survival surgery on systemic and mucosal immune responses in SIV‐infected rhesus macaques
Authors: Edghill‐Smith Yvette Y. , Aldrich Kristine , Zhao Jun , Pinczewski Joel , Kalyanaraman V.S. , Johnson Monae , Heyliger Aliya , Preston Perrin R. , Woodward Ruth , Robert‐Guroff Marjorie
Published: March 2003

Abstract: Evaluation of cellular immunity in the intestinal lamina propria of rhesus macaques has been used previously to assess protective immunity against mucosal simian immunodeficiency virus (SIV) challenges. As this technique requires survival surgery to obtain jejunal tissue, effects of surgical stress on the immune system were investigated. SIV‐specific immune responses, including IgG and IgA binding antibodies in sera and mucosal secretions, IgG and IgA secreting cells in peripheral blood, IgG neutralizing antibodies, T‐cell proliferative responses, and interferon‐γ secretion by peripheral blood mononuclear cells, were evaluated pre‐ and post‐surgery in macaques immunized with adenovirus‐SIV recombinant vaccines and SIV envelope protein and in SIV‐infected macaques. No differences in these immune parameters were observed in SIV‐naïve, immunized macaques or healthy SIV‐infected macaques with regard to surgery. A dramatic increase in total IgA antibody level following surgery in the rectal secretions of one SIV‐infected macaque that was rapidly progressing to AIDS and failed to recover from surgery was attributed to an abscess that developed at the intestinal site. To date, nearly 30 other macaques have undergone the intestinal survival surgery, some on more than one occasion, without experiencing any clinical difficulty. Overall, our results suggest that in healthy macaques, intestinal resection survival surgery can be conducted safely. Further, the method can be used to reliably sample the intestinal mucosa without major or persistent impact on humoral or cellular immune responses.
Serological evidence of alpha herpesvirus infection in sooty mangabeys
Authors: Henkel R.D. , McClure H.M. , Krug P. , Katz D. , Hilliard J.K.
Published: March 2003

Contact between sooty mangabeys (SMs) and a pigtailed macaque prompted the serological screening of SMs for evidence of infection with B virus. Serological tests detected SM antibodies that reacted with B virus polypeptides. Additional testing was performed with sera from SMs with no previous contact with macaques. Results from these tests indicated that 56% (33/59) of the SMs had antibodies that reacted with B virus and SA8. SM antibodies also reacted with herpesvirus papio 2 and to a lesser extent with human alpha herpesviruses (HSV‐1 and HSV‐2). There was an age‐related increase in the presence of these antibodies in SMs that was consistent with the serological pattern of reactivity observed in other nonhuman primate species infected with alpha herpesviruses. These data suggest that SMs may be a host for a herpesvirus that is antigenically similar to those viruses present in other Old World nonhuman primates.
The FIC1 gene: structure and polymorphisms in baboon
Authors: Cox Laura A.
Published: March 2003

A genome scan performed on 648 pedigreed baboons to detect and localize quantitative trait loci (QTL) for lipoprotein phenotypes that are known risk factors for atherosclerosis indicated the presence of a QTL on chromosome 18q that exerts a major influence on HDL‐cholesterol (HDL‐C) related phenotypes. Inspection of the human gene map revealed that the familial intrahepatic cholestatis gene 1 (FIC1) maps to the homologous region of baboon chromosome 18 containing the major QTL influencing HDL‐C phenotypes. FIC1 is a strong biological candidate for this QTL because HDL‐C is the preferred precursor for bile acid synthesis. In this study, we cloned and sequenced FIC1 cDNA and found that it is highly conserved between human and baboon. We also sequenced FIC1 cDNAs from a panel of unrelated baboons revealing single nucleotide polymorphisms (SNPs) and a polymorphic dinucleotide repeat. None of the baboon SNPs corresponded to human FIC1 mutations associated with familial intrahepatic cholestasis or benign recurrent intrahepatic cholestasis disorders.
Polymorphism in the Rhesus macaque (Macaca mulatta) NRAMP1 gene: lack of an allelic association to tuberculosis susceptibility
Authors: Deinard Amos S. , Lerche Nicholas W. , Smith David Glenn
Published: March 2003

Although previous tuberculosis (TB) research has suggested that underlying genetic factors influence a host's response and ability to survive Mycobacterium infection, only recently has a gene been identified, the `natural resistance‐associated macrophage protein 1' (NRAMP1) gene, which provides a degree of natural resistance to infection by some Mycobacterium species. To date, however, the role that NRAMP1 may play in resistance to Mycobacterium infection has only been examined in mouse and man. Here, we present data generated at NRAMP1 among a group of rhesus macaques (Macaca mulatta) that were euthanized because of an outbreak of Mycobacterium tuberculosis during quarantine. Data were also generated on unrelated (and healthy) rhesus macaques in order to better determine the frequency and degree of genetic polymorphism within Macaca at the NRAMP1 locus. These data represent the first study designed to examine the role that NRAMP1 may play in TB susceptibility among rhesus macaques.
Reproduced wootz Damascus steel
Authors: Perttula Juha
Published: March 2003

The best Damascus blades were forged in Persia from Indian wootz steel having a carbon content of about 1.5%. They became famous for their high quality and distinct surface patterns which resulted from small cementite particles arranged in parallel layers. The last highest‐quality blades were made perhaps in the 18th century, after which the art was temporarily lost. Recently, it has been rediscovered. In this paper, it is shown that this ancient steel material can be reproduced by a modern foundry. The addition of about 0.5% Cr is essential. The interdendritic segregation of Cr and thermal cycling lead to the formation of the characteristic layered microstructure in forged specimens. Cr also prevents graphitization.
Interaction between inclusion particles on the stainless‐steel melt surface
Authors: Luo Haiwen
Published: March 2003

Behaviors of inclusion particles on the stainless‐steel melt surface were observed in real time by confocal laser microscopy, and theory of capillary interaction was introduced to explain the attractive behavior between some inclusion particles. Solid and semiliquid particles could attract and agglomerate by capillary force, and attraction is much stronger for solid particles. The melt surface was depressed around non‐wetting inclusions, which could be well‐described by the mathematic model for capillary interaction. However, liquid inclusion particles, showing no attraction, seldom merged and dispersed with some separation on the melt surface, because Marongoni flow, resulting from gradient of sulfur concentration, separated them.
Thoughts about the initial solidification process during continuous casting of steel
Authors: Fredriksson Hasse , Elfsberg Jessica
Published: March 2003

The initial solidification during continuous casting is very important for the surface quality of the strand. Oscillation marks are formed by the movement of the mould. One mainly distinguishes between two different types of marks, namely folding marks and overflow marks. The formation of these can be described by the heat flow and the surface tension balance. A theoretical analysis outlining the most important parameters controlling the formation of these marks is presented. A metallographic analysis of the formation was also performed. The theory and observations have been used to analyse the effect of casting speed and oscillation frequency on the formation of different types of marks. It is shown that a meniscus is formed at the top of the growing shell. The maximum height of the meniscus determines the ideal distance between the marks. The mould frequency is related to this height. A frequency that is far from ideal causes overflow marks and folding marks with macrosegregation and cracks. The distance between the marks is, in such cases, not constant. The depth of the marks is calculated from the heat flow and the surface tension balance.
Evolution of microstructure in an ultra‐low carbon Cu bearing HSLA forging
Authors: Das Samar , Ghosh A. , Chatterjee S. , Rao P. Ramachandra
Published: March 2003

Over the last decade low carbon age hardenable steels have become a subject of interest for naval applications. In the present study an ultra‐low carbon Ni‐bearing steel alloyed with Cu was cast and processed by controlled forging and subsequently cooled in air, sand and water. A variety of multiphase structures have been observed because of different cooling rates. The slowest cooling rate has produced bainitic ferrite by ledge mechanism whereas lath‐ or plate‐type bainitic ferrite was predominant at the faster cooling rates. The volume fraction of retained austenite and/or martensite austenite constituents increased with decreasing cooling rate. Precipitation of finer micro‐alloying carbides and carbonitrides was suppressed by faster cooling. Slow cooling rates also resulted in the formation of ɛ‐Cu precipitates of varying sizes and shapes.
Predator‐mediated apparent competition between an introduced grass, Agrostis capillaris, and a native fern, Botrychium australe (Ophioglossaceae), in New Zealand
Authors: Sessions Laura , Kelly Dave
Published: March 2003

This study provides an example of how invasive plant species may indirectly affect native species through apparent competition by altering the local invertebrate community. The native New Zealand fern Botrychium australe (Ophioglossaceae) is thought to benefit from disturbances such as fire, because this species is generally found in disturbed habitats with low shade and increasing competition. However, in this study we show that a mapped population of B. australe experienced a marked decrease in survival and reproduction after an accidental fire in May 1995. Mortality was not due to the direct effects of fire; in the year following the fire, survival was normal and reproduction was higher than in previous years. However, after 1996 an introduced grass (Agrostis capillaris) spread across the area and B. australe survival in the second to fourth years after the fire (1996–1999, 59.63%) was significantly lower than survival before the fire, and plants did not produce spores at all during this 3‐yr period. B. australe survival was not lower in plots with dense A. capillaris growth. From 1997 onwards, B. australe plants suffered very extensive defoliation by a herbivore, and insecticide and molluscicide experiments in 1999 and 2000 showed that the introduced slug Deroceras reticulatum was responsible for the damage. The slug increased after the fire in association with the spread of Agrostis capillaris, probably because this plant created a suitable habitat for slugs.
Foliage color contrasts and adaptive fruit color variation in a bird‐dispersed plant community
Authors: Burns K. C. , Dalen J. L.
Published: March 2003

The color of vertebrate‐dispersed fruits has been a source of inquiry for over 150 years, yet the ecological and evolutionary processes responsible for fruit color diversity remain elusive. We tested the hypothesis that fruit color varies temporally, to maximize conspicuousness against seasonal changes in foliage coloration, in a bird‐dispersed plant community in western North America. Field observations showed that while red fruits predominate during summer periods of green foliage coloration, black fruits are produced during flushes of red‐orange foliage coloration in autumn. Although two species did not conform to this pattern, one produced its own contrasting background color, via colored bracts. We conducted experimental manipulations of both fruit color and the color of artificial backgrounds to test whether both factors had a synergistic effect on fruit removal rates. Interactions between fruit and background color explained most of the variation in experimental fruit removal rates. Although red fruits were removed rapidly on green backgrounds, preference for black fruits on red‐orange backgrounds was less pronounced. Consequently, the temporal pattern in fruit color appears to result from elevated fruit conspicuousness against seasonal changes in foliage coloration. Support for this hypothesis suggests a temporal connection between fruit color diversity, foliage color contrasts and avian color preferences.
Low humidity reduces ectoparasite pressure: implications for host life history evolution
Authors: Moyer Brett R. , Drown Devin M. , Clayton Dale H.
Published: March 2003

A parasite's potential effect, or “pressure”, can influence the life history strategy of its host. In environments with high parasite pressure, hosts invest more in anti‐parasite defense, which may limit their investment in other life history components, such as survival. This tradeoff is difficult to study in natural populations because pressure is hard to quantify. Pressure is not necessarily correlated with the abundance of the parasite. A host population can be under high pressure, yet have few parasites, because members of the population have invested heavily in defense. Therefore, the extent to which parasite pressure varies among host populations, and the cause of such variation, remain largely undocumented. In this paper we show that birds in arid regions have fewer ectoparasitic lice than birds in humid regions. We show experimentally that low humidity reduces the number of lice on birds, even when host defense is held constant. Comparisons of ambient humidity to humidity beneath the plumage demonstrate that plumage does not provide a buffer for lice against low humidity. Our results confirm that an abiotic factor can cause substantial variation in parasite pressure among host populations. We suggest that humidity may influence host life history evolution through its impact on ectoparasites.
Coherence, species turnover, and boundary clumping: elements of meta‐community structure
Authors: Leibold Mathew A. , Mikkelson Gregory M.
Published: March 2003

Ecologists have identified several kinds of pattern in the distribution of species among sites, including a) nested subsets, b) checkerboards, c) Clementsian gradients, d) Gleasonian gradients, and e) evenly spaced gradients. Most past efforts to diagnose such patterns have focused on only one at a time, often contrasted with a sixth type of pattern, f) “randomness”. While there are statistical tests to distinguish each of the first five patterns from randomness, there are currently no established methods for discriminating among these first five patterns in a given data set. Here we propose a method that will identify which of these possibilities is most prevalent in a site‐by‐species incidence matrix based on three basic aspects of meta‐community structure. Our method is based on first ordinating the incidence matrix to identify the dominant axis of variation and identifying three aspects variation along this dominant axis. The first aspect, “coherence”, is the degree to which pattern can be collapsed into a single dimension. The second, “species turnover”, describes the number of species replacements along this dimension. The third aspect, “boundary clumping”, has to do with how the edges of species boundaries are distributed along this dimension. We present methods for analyzing these three aspects of meta‐community structure, use them to identify the six different patterns, and illustrate them with a representative set of cases drawn from previously published data.