bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell wall‐associated isoflavonoids andβ‐glucosidase activity inLupinus albusplants responding to environmental stimuli
Authors: Piślewska M. , Bednarek P. , Stobiecki M. , Zieliśska M. , Wojtaszek P. 
Published: March 2003

AbstractPlants respond to various biotic or abiotic stimuli with different mechanisms and the mobilization of phenolic compounds is one of them. In white lupin (Lupinus albusL.) plants, isoflavones and their glucosides were localized in cell walls where the high constitutive activity ofβ‐glucosidase (EC 3·2·1·21) was also identified. The enzyme was partially purified from root cell walls. Its polymeric active form has 180 or 200 kDa as determined by non‐denaturing electrophoresis and gel filtration, respectively, and the isoelectric point is at pH 6·9. The enzyme is an exoglucosidase, preferentially hydrolysing conjugates of phenolic compounds withβanomers of glucose. It is not active against purified lupin cell walls. The specificβ‐glucosidase activity varies in different tissues with the highest one in roots, and always higher in cell walls than in protoplast. The cell wall location of the enzyme was confirmed biochemically by its activity in intercellular washing fluids. Both aglycones and glycosides were also present in these fluids. The specificβ‐glucosidase activity correlated well with the isoflavonoid aglycone/glycoside ratios in various tissues: the higherβ‐glucosidase activity, the higher relative aglycone content.β‐glucosidase activity was found to be inducible under conditions of yeast elicitor treatment. Induction of the enzyme was accompanied by changes in the isoflavone secretion and accumulation, suggesting the regulatory role ofβ‐glucosidase activity in root exudation of isoflavonoids. No correlation however, was found between changes inβ‐glucosidase activity and the presence of isoflavonoids in root exudates of plants grown under various nitrogen nutrition regimes.
Similarity and diversity in adventitious root anatomy as related to root aeration among a range of wetland and dryland grass species
Authors: McDonald M. P. , Galwey N. W. , Colmer T. D. 
Published: March 2003

AbstractAssessments of the anatomy, porosity and profiles of radial O2 loss from adventitious roots of 10 species in the Poaceae (from four subfamilies) and two species in the Cyperaceae identified a combination of features characteristic of species that inhabit wetland environments. These include a strong barrier to radial O2 loss in the basal regions of the adventitious roots and extensive aerenchyma formation when grown not only in stagnant but also in aerated nutrient solution. Adventitious root porosity was greater for plants grown in stagnant compared with aerated solution, for all 10 species in the Poaceae. The ‘wetland root’ archetype was best developed in Oryza sativa and the two species of the Cyperaceae, in which the stele contributed less than 5% of the root cross‐sectional area, the cells of the inner cortex were packed in a cuboidal arrangement, and aerenchyma was up to 35–52%. Variations of this root structure, in which the proportional and absolute area of stele was greater, with hexagonal arrangements of cells in the inner cortex and varying in the extent of aerenchyma formation, were present in the other wetland species from the subfamilies Pooideae, Panicoideae and Arundinoideae. Of particular interest were Vetiveria zizanoides and V. filipes, wetland grass species from the tribe Andropogoneae (the same tribe as sorghum, maize and sugarcane), that had a variant of the root anatomy found in rice. The results are promising with regard to enhancing these traits in waterlogging intolerant crops.
Body protein does not vary despite seasonal changes in fat in the White StorkCiconia ciconia
Authors: Michard‐Picamelot Delphine , Zorn Thierry , Gendner Jean‐Paul , Mata Astolfo J. , Maho Yvon Le 
Published: March 2003

To understand how a large soaring bird, the White StorkCiconia ciconia, copes with energy constraints, we compared changes in body mass in 14 captive adult storks with the body composition of 12 free‐ranging adult storks found dead from accidents. The captive storks, already in an enclosure for several years, were fedad libitum. They were weighed daily for 1.5–3.5 years using an automatic device. The bodies of the accidentally killed storks were analysed to determine total water, lipid, protein and ash contents, and to assess the biochemical composition of certain organs. Females were on average 20% lighter and 24% smaller than males, but the body mass of the sexes varied in parallel throughout the year. Body mass peaked in December and January (25–30% above minimal body mass), due essentially to large fat stores in subcutaneous and abdominal adipose tissues. Body mass and body lipid rapidly decreased from February to June, whether the storks reared chicks successfully or not, and remained minimal for a few days into July. In contrast to birds using flapping flight, no variation in body protein or pectoral muscle protein was observed while breeding, even though the moult occurred then, nor in August, before the time when wild storks migrate. An endogenous regulation of body fuels is discussed.
Medroxyprogesterone acetate enhances in vivo and in vitro antibody production
Authors: Vermeulen Mónica , Pazos Patricia , Lanari Claudia , Molinolo Alfredo , Gamberale Romina , Geffner Jorge R. , Giordano Mirta 
Published: March 2003

SummaryIn the present study we examine the effects of medroxyprogesterone acetate (MPA) on the specific antibody secretion to T‐dependent antigens. Our results show that the in vivo administration of MPA to mice, 7 or 90 days before immunization with sheep red blood cells (SRBC), significantly enhanced both, primary and secondary antibody responses, without affecting delayed‐type hypersensitivity (DTH). These effects could be counteracted by the anti‐progestin onapristone or ZK 98299 (ZK) suggesting that MPA interacted with progesterone (PRG) receptors to increase B‐cell response. To better understand the mechanisms involved in MPA activity we carried out cultures of splenocytes, bone marrow cells or lymph node cells from immunized mice in the presence of MPA, and evaluated the amount of antibody release to supernatants. We found that low doses of MPA (10−9 m and 10−10 m) significantly enhanced the in vitro production of specific immunoglobulin G (IgG) antibodies, an effect that appears to involve the interaction of the progestin with PRG receptors, as judged by the inhibition of MPA effects with ZK (10−8 m) or RU486 (10−9 m). These receptors were detected by flow cytometry analysis in a proportion of T lymphocytes. Because MPA did not increase the number of immunoglobulin‐secreting cells, our findings suggest that MPA enhanced the capacity of individual cells to produce specific immunoglobulin.
Inhibition of B16 melanoma experimental metastasis by interferon‐γ through direct inhibition of cell proliferation and activation of antitumour host mechanisms
Authors: Kakuta Shigeru , Tagawa Yoh‐ichi , Shibata Shinwa , Nanno Masanobu , Iwakura Yoichiro 
Published: March 2003

SummaryInterferon‐γ (IFN‐γ) has pleiotropic activities other than its antivirus action, including cell growth inhibition, natural killer (NK) cell and cytotoxic T lymphocyte (CTL) activation, and angiogenesis inhibitory activity, and these activities are supposed to be involved in its antitumour activity. However, it has not been completely elucidated which activity is mainly involved in the tumour suppression in vivo. In this study, we analysed inhibitory mechanisms of endogenous IFN‐γ against B16 melanoma experimental metastasis. After intravenous injection of tumour cells, tumour deposits in the lungs and liver were increased and life span was shorter in IFN‐γ−/− mice, indicating important roles for IFN‐γ in antitumour mechanisms. Interestingly, tumour deposits were not increased in IFN‐γ receptor (R)−/− mice. Furthermore, only low levels of cell‐mediated immunity against the tumour and activation of NK cells were observed, indicating that antimetastatic effects of IFN‐γ is not mediated by host cells. The survival period of B16 melanoma‐bearing IFN‐γR−/− mice was, however, shorter than wild‐type mice. These observations suggest that IFN‐γ prevents B16 melanoma experimental metastasis by directly inhibiting the cell growth, although antitumour host functions may also be involved in a later phase.
Immunological characterization of a γδ T‐cell stimulatory ligand on autologous monocytes
Authors: Sathiyaseelan Thillainayagam , Naiman Brian , Welte Stefan , Machugh Niall , Black Samuel J. , Baldwin Cynthia L. 
Published: March 2003

SummaryBovine γδ T cells are stimulated to proliferate by autologous monocytes. This is referred to as the autologous mixed leucocyte reaction (AMLR). It has been shown previously that the stimulatory component is constitutively expressed on the monocyte plasma membrane and is a protein or has a protein moiety. Here we showed that γδ T‐cell responses to the monocytes requires interaction with the T‐cell receptor because Fab1 fragments of a monoclonal antibody (mAb) that reacts with the δ chain of the T‐cell receptor blocked proliferation in the AMLR. Monocyte molecules involved in stimulation were also characterized further by biochemical and immunological methods. A mAb, named M5, was generated by immunizing mice with bovine monocytes and shown to block the ability of monocytes to stimulate in the AMLR. Treatment of monocytes or monocyte membranes with high salt, chelating agents or phospholipase C did not affect their ability to stimulate γδ T‐cell proliferation or reactivity with mAb M5 indicating the ability of monocytes to stimulate does not involve peripheral membrane components or a glycosyl‐phosphatidylinsositol (GPI)‐anchored components. Hence it was concluded that the stimulation occurred as a result of intergral membrane proteins including that recognized by mAb M5. The ligand for mAb M5 was on all bovine monocytes and to a lower level on granulocytes but not on lymphocytes. MAb M5 also reacted with sheep monocytes but not with human monocytes or murine macrophages, in agreement with a previous reports that sheep monocytes but not human or mouse mononuclear phagocytes have the capacity to stimulate bovine γδ T cells in in vitro cultures. The level of expression of the M5 ligand was not altered by γ‐irradiation or culture of monocytes with lipopolysaccharide but it was decreased following culture with interferon‐γ‐containing cell culture supernatants.
Immunization onto bare skin with synthetic peptides: immunomodulation with a CpG‐containing oligodeoxynucleotide and effective priming of influenza virus‐specific CD4+ T cells
Authors: Beignon Anne‐Sophie , Briand Jean‐Paul , Muller Sylviane , Partidos Charalambos D. 
Published: March 2003

SummaryExploiting the immune system of the skin for vaccine administration offers an attractive alternative to the currently used invasive immunization procedures. In this study we report that a synthetic peptide representing a T‐helper (Th) epitope from influenza virus haemagglutinin (aa 307–319) can be an effective immunogen when coapplied with cholera toxin (CT) onto bare skin. Proliferation of both peptide‐ and influenza virus‐specific CD4+ T cells was measured in lymphocyte cultures from spleens and regional lymph nodes. The presence of the CpG oligodeoxynucleotide 1826 in the peptide/CT formulation, enhanced the proliferation of peptide‐ and virus‐specific T cells as measured by the conventional [3H]thymidine uptake and interleukin (IL)‐2 assays. Furthermore, the bias towards Th2‐type of responses stimulated by CT was shifted towards Th1 as demonstrated (i) by the increase of interferon‐γ and decrease of IL‐4 cytokine levels measured in culture supernatants, (ii) by the predominance of IG2a anti‐CT antibodies in the serum, and (iii) by the down‐regulation of total serum IgE antibody levels. These findings demonstrate the potential of the bare skin as a non‐invasive route for administration of small molecular size peptide antigens. Furthermore, with the selection and combination of the appropriate type of adjuvants, immune responses can be modulated towards the desired type of Th phenotype.
Association of the absence of palmaris longus tendon with an anomalous superficial palmar arch in the human hand
Authors: O'Sullivan Elizabeth , Mitchell Barry S 
Published: March 2003

AbstractThe normal arterial supply to the human hand is via the ulnar and radial arteries which unite mid‐palm to form a complete arch called the superficial palmar arch (SPA). From the SPA blood vessels pass anteriorly to supply the thumb and digits, and deeply to complete the deep palmar arch. Previous reports have documented anomalies of the SPA formation, and this may change the normal blood distribution to the thumb and the digits. There have also been reports of the absence of the palmaris longus tendon. A total of 47 embalmed cadaveric hands (some paired, some single) were dissected and the presence of an anomalous SPA was more frequently observed when the palmaris longus tendon was absent. This may be significant when considering the suitability of patients for hand surgery which involves interruption to the vascular supply to the hand, e.g. harvesting upper limb vessels for coronary artery grafting. The current techniques for assessing the vascular supply to the hand (Allens test and/or Doppler ultrasounding) are unreliable. Demonstration of a palmaris longus tendon in the living arm is easy and the use of this in combination with the other techniques may improve overall reliability.
Demographic dynamics of a neotropical small rodent (Phyllotis darwini): feedback structure, predation and climatic factors
Authors: Lima Mauricio , Julliard Romain , Stenseth Nils CHR. , Jaksic Fabian M. 
Published: March 2003

Summary

The leaf‐eared mouse (Phyllotis darwini) exhibits large numerical fluctuations associated with high‐ and low‐rainfall years in semi‐arid Chile. Using capture–mark–recapture (CMR) statistical modelling, we provide a detailed description of the demographic variation in this species. We studied between‐year and seasonal variation of demography, and tested for the relative importance of endogenous and exogenous factors as covariates of survival, recruitment, maturation and reproduction over a 12‐year period.
The demographic variables studied show larger between‐year than within‐year (seasonal) variation, emphasizing the importance of this source of external variability. We found that both feedback structure and exogenous factors operate together on different demographic processes of this species.
We found positive direct feedback effects on survival rate and negative feedback on recruitment, fraction of reproductive individuals and female maturation rates. The ratio between barn and magellanic horned owls showed an important effect on most of the demographic variables of leaf‐eared mice, in particular by influencing negatively survival rates and the fraction of reproductive individuals, thus suggesting the importance of non‐lethal predation.
Hence, feedback intrinsic mechanisms (density‐dependence), owls and climate (rainfall and Southern Oscillation Index (SOI)) operate simultaneously in determining the demography of leaf‐eared mice. We hypothesize that trophic interactions with owls (and perhaps other predators) may cause second‐order feedback responses in demography and population dynamics of this small rodent species.
Delayed cost of reproduction and senescence in the willow tit Parus montanus
Authors: Orell Markku , Belda Eduardo J. 
Published: March 2003

Summary

We studied age‐specific survival rates in the willow tit Parus montanus in northern Finland using 15 years of capture–recapture data obtained from birds during the breeding seasons 1986–2000. In addition, short‐ and long‐term costs of reproduction were investigated by comparing survival probabilities of breeding and non‐breeding individuals.
We did not find evidence supporting age‐specific survival probabilities in males. However, in females there was a significant decline in survival after the age of 5 years.
Reproduction did not impair individuals’ chances of being alive in the subsequent year (short‐term cost) because breeding males and females had similar survival rates as non‐breeders.
Demographic costs of breeding appeared later in life. Females skipping breeding earlier in life showed a higher probability of survival after the age of 5 years than females that bred every year until that age. This effect was non‐significant in males.
The observed decline in survival probability late in life is likely to result from an increased cost of reproduction due to higher allocation of resources to breeding earlier in life, i.e. increased effort early in life is traded with survival late in life. The results also suggest that income breeders, such as small passerines, may pay long‐term costs of reproduction. This is in agreement with the disposable soma theory of ageing.
Diagnosing the cause of population changes: localized habitat change and the decline of the endangered St Helena wirebird
Authors: McCulloch Neil , Norris Ken 
Published: March 2003

SummaryStatistical models of population density and/or change in relation to habitat could aid the management of endangered species and help diagnose causes of population decline. Such models seek ‘global’ explanations for any decline, but endangered species are often vulnerable to highly localized habitat change that can have a significant impact on overall population. In such cases, statistical models can aid in interpreting the impact of localized habitat change on population density and so have a role in diagnosis. We illustrate this approach using data from the endangered St Helena wirebird, a small sand plover endemic to the island of St Helena in the South Atlantic Ocean. The wirebird inhabits pasture habitats and semi‐desert areas. Census data suggest that wirebird abundance declined during the early 1990s, from 425 adult birds in 1989 to 335 adult birds by 1998–99. Abundance declined by 34·4% in pasture habitats, whereas abundance in semi‐desert increased by 18% over this period.We tested the hypothesis that the decline in abundance in pasture habitats was driven by vegetation change. Multiple regression modelling revealed that wirebird density in pasture was positively correlated with the cover of broad‐leaved herbs, but negatively correlated with vegetation height and gorse cover prior to the decline in 1989. A performance test of this model showed that predictions were reliable.The cover of broad‐leaved herbs declined significantly between 1989 and 1998–99. However, there was no correlation between the change in wirebird density and the change in broad‐leaved herb cover, indicating that this vegetation change was unlikely to have caused the decline in wirebird abundance.The decline in the abundance of wirebirds in pasture habitats was primarily due to changes in three sites. Each experienced site‐specific habitat changes, which were likely to cause a decrease in wirebird abundance on the basis of the multiple regression modelling of wirebird density in relation to habitat. We concluded that highly localized vegetation change, rather than general herb cover, played an important role in the overall population decline.Our analysis provides clear habitat management recommendations: pasture management for livestock needs to be compatible with the production of herb‐rich grassland, consisting of short vegetation and few woody plants, in order to benefit wirebird conservation. Management decisions for endangered species are often required urgently, and as a result are invariably based on incomplete information, particularly concerning the demographic mechanisms involved in decline. Our approach illustrates a role for simple statistical models under these circumstances. Such models help diagnose the cause of a decline and promote initial, remedial, management actions. This work also shows how habitat effects on endangered species can be highly localized.
Differential facilitation by a nitrogen‐fixing shrub during primary succession influences relative performance of canopy tree species
Authors: Bellingham P. J. , Walker L. R. , Wardle D. A. 
Published: March 2003

Summary

The facilitative and inhibitory effects of a nitrogen‐fixing shrub, Carmichaelia odorata, during primary succession were studied using both field measurements in a New Zealand temperate montane valley, and manipulative glasshouse experiments on seedlings of the three dominant tree species, Griselinia littoralis, Metrosideros umbellata and Weinmannia racemosa.
During a stand development chronosequence of < 100 years in which Carmichaelia colonized, dominated and senesced, there was significant development of soil organic horizons and a large build‐up of soil nitrogen, especially in the organic horizon. Soil organic matter and nitrogen levels across the sequence were strongly correlated with the main DCA axis of vascular plant species composition, along which there was change in dominance from herbaceous to woody species. Vegetation increased in height and light levels declined with stand development.
Similar responses to shade that mimicked that in mature Carmichaelia stands suggested that inhibitory effects were likely to be uniform across the three tree species.
Nitrogen, either added via Carmichaelia litter or in solution, enhanced shoot biomass and foliar nitrogen concentrations of all three tree species. Growth in soils of increasing development increased foliar nitrogen concentrations for Griselinia and Weinmannia, but not Metrosideros.
Overall, Metrosideros was the least responsive to potential facilitative effects of Carmichaelia, and Griselinia exhibited the highest degree of plasticity of response. Future forest composition and spatial patterning of species in mixed stands here, as elsewhere, is likely to result from differential facilitative responses during early primary succession.
Bone morphogenetic protein‐7 stimulates initial dendritic  growth in sympathetic neurons through an intracellular  fibroblast growth factor signaling pathway
Authors: Horbinski C. , Stachowiak E. K. , Chandrasekaran V. , Miuzukoshi E. , Higgins D. , Stachowiak M. K. 
Published: March 2003

AbstractBone morphogenetic protein‐7 (BMP‐7), a member of the transforming growth factor (TGF)‐β superfamily of signaling cytokines, induces dendritic growth in rat sympathetic neurons. In this study, we present evidence that the recently discovered integrative nuclear FGFR1 signaling (INFS) pathway is involved in dendrite outgrowth mediated by BMP‐7. Immunocytochemical analysis of expressed fibroblast growth factors (FGFs) showed that little FGF‐2 was detected in control neurons, but the expression of this molecule in the cytoplasm and nucleus increased within 6 h after BMP‐7 treatment. In contrast, FGF‐1 was constitutively present in the peripheral cytoplasm and in neurites under control conditions, and its distribution did not change with BMP‐7 exposure. The high‐affinity receptor FGFR1 was present in low amounts in control neurons and was associated with the cytoplasm, the plasma membrane, and the nucleus. Twenty‐four hours of␣BMP‐7 treatment elicited an increase in FGFR1 nuclear localization. Overexpressed constructs of FGFR1 that lack the␣tyrosine kinase domain, and have been shown to act in a␣dominant‐negative manner on FGFR1 signaling, inhibited BMP‐7 mediated initial dendrite outgrowth in transfected neurons by ≈ 50%. However, targeted inhibition of extracellular FGF‐2 by overexpression of a secreted receptor mutant FGFR1(TM–) lacking the transmembrane domain failed to affect BMP‐7 induced dendritic growth, as did treatment with the extracellular FGFR antagonist inositol hexakisphosphate. These results suggest that the INFS, which has already been␣implicated in a broad range of activities in other cell types, may also be required for BMP‐7 to stimulate dendritic development.