bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prospects for development of a transmission blocking vaccine against Schistosoma japonicum
Authors: McMANUS D. P. 
Published: August 2005

SUMMARY Despite intensive long‐term control programmes, schistosomiasis japonica remains a serious public health problem in China and the Philippines. The termination of mass praziquantel‐treatment has seen a dramatic recent rebound in both its prevalence and associated morbidity. Schistosomiasis japonica is a zoonosis but, despite complicating control efforts, this feature provides a practical method for attacking Schistosoma japonicum through development and deployment of a transmission blocking veterinary vaccine. A recently completed bovine drug intervention trial and mathematical modelling of the transmission of S. japonicum underpin the concept that such a vaccine, targeting water buffalo, would have major implications for future integrated schistosomiasis control in China. A major block to success is the low ceiling efficacy achieved with current vaccine molecules. To solve this challenge, an antigen discovery pipeline needs to be established for identification of new vaccine targets that induce greater potency than the current anti‐S. japonicum candidate vaccines. Excretory–secretory products and molecules exposed on epithelial surfaces (including receptors) which interact directly with the host immune system warrant especial attention. Extensive schistosome genomics programmes currently underway coupled with new advances in proteomics and microarray technology provide an unparalleled opportunity to identify new molecules exploitable as vaccine targets. These will then need to be produced in quantity and rigorously tested first in the laboratory and then the field. If a transmission blocking veterinary vaccine developed for bovines can be put into practice in combination with other control strategies such as human chemotherapy, elimination of S. japonicum from China may be achievable.
Leaf internal diffusion conductance limits photosynthesis more strongly in older leaves of Mediterranean evergreen broad‐leaved species
Authors: NIINEMETS ÜLO , CESCATTI ALESSANDRO , RODEGHIERO MIRCO , TOSENS TIINA 
Published: August 2005

ABSTRACTLeaf age‐dependent changes in structure, nitrogen content, internal mesophyll diffusion conductance (gm), the capacity for photosynthetic electron transport (Jmax) and the maximum carboxylase activity of Rubisco (Vcmax) were investigated in mature non‐senescent leaves of Laurus nobilis L., Olea europea L. and Quercus ilex L. to test the hypothesis that the relative significance of biochemical and diffusion limitations of photosynthesis changes with leaf age. The leaf life‐span was up to 3 years in L. nobilis and O. europea and 6 years in Q. ilex. Increases in leaf age resulted in enhanced leaf dry mass per unit area (MA), larger leaf dry to fresh mass ratio, and lower nitrogen contents per dry mass (NM) in all species, and lower nitrogen contents per area (NA) in L. nobilis and Q. ilex. Older leaves had lower gm, Jmax and Vcmax. Due to the age‐dependent increase in MA, mass‐based gm, Jmax and Vcmax declined more strongly (7‐ to 10‐fold) with age than area‐based (5‐ to 7‐fold) characteristics. Diffusion conductance was positively associated with foliage photosynthetic potentials. However, this correlation was curvilinear, leading to lower ratio of chloroplastic to internal CO2 concentration (Cc/Ci) and larger drawdown of CO2 from leaf internal air space to chloroplasts (ΔC) in older leaves with lower gm. Overall the age‐dependent decreases in photosynthetic potentials were associated with decreases in NM and in the fraction of N in photosynthetic proteins, whereas decreases in gm were associated with increases in MA and the fraction of cell walls. These age‐dependent modifications altered the functional scaling of foliage photosynthetic potentials with MA, NM, and NA. The species primarily differed in the rate of age‐dependent modifications in foliage structural and functional characteristics, but also in the degree of age‐dependent changes in various variables. Stomatal openness was weakly associated with leaf age, but due to species differences in stomatal openness, the distribution of total diffusion limitation between stomata and mesophyll varied among species. These data collectively demonstrate that in Mediterranean evergreens, structural limitations of photosynthesis strongly interact with biochemical limitations. Age‐dependent changes in gm and photosynthetic capacities do not occur in a co‐ordinated manner in these species such that mesophyll diffusion constraints curb photosynthesis more in older than in younger leaves.
Needle cell elongation and maturation timing derived from pine needle cellulose δ18O
Authors: WRIGHT WILLIAM E. , LEAVITT STEVEN W. 
Published: August 2005

ABSTRACTEstimates of the timing of Pinus arizonica Engelm. needle development in 1998 and 1999 were derived from the leaf‐cellulose δ18O of weekly growth increments. Significant correlations were noted between time series of local humidity and leaf‐cellulose δ18O for needles growing near Tucson, Arizona. Correlations with temperature were also significant, but much lower, suggesting these variations in cellulose δ18O were determined mostly by changes in humidity. The timing of all significant correlations lags the timing of the appearance of the new needle growth, and is interpreted as indicating 16–23 d were required for cell enlargement in 1998 and 13–17 d in 1999. Similarly, properties of the environmental time series, when significantly correlated, are interpreted as indicating the duration of cellulose deposition (7–27 d in 1998, 13–21 d in 1999). Variations in stable‐isotope back diffusion (the Péclet effect) and the synthesis of cellulose using stored photosynthate are discussed as explanations for departures from a Craig and Gordon‐type model of leaf water δ18O. The Péclet effect, use of stored photosynthate, and variations in the growing‐season source‐water δ18O, probably confound the development of a high‐resolution paleohumidity proxy from subfossil needle cellulose δ18O in this region.
JrSUT1, a putative xylem sucrose transporter, could mediate sucrose influx into xylem parenchyma cells and be up‐regulated by freeze–thaw cycles over the autumn–winter period in walnut tree (Juglans regia L.)
Authors: DECOURTEIX MÉLANIE , ALVES GEORGES , BRUNEL NICOLE , AMÉGLIO THIERRY , GUILLIOT AGNÈS , LEMOINE RÉMI , PÉTEL GILLES , SAKR SOULAIMAN 
Published: September 2005

ABSTRACTSucrose has been reported to play multiple roles in the winter biology of temperate woody species. However, no report on the molecular basis of sucrose transport in xylem tissue has yet been made. In the walnut tree, it is demonstrated that during the autumn–winter period, active absorption of sucrose from xylem vessels to parenchyma cells (sucrose influx) is much higher when samplings were taken shortly after a period of freezing temperatures. Here, the question of whether this increased sucrose influx mirrors a regulation of sucrose transporters in xylem tissue was tested. A putative sucrose transporter cDNA (JrSUT1: Juglans regia sucrose transporter 1) was isolated. Over the autumn–winter period, JrSUT1 transcripts and respective proteins were present in xylem parenchyma cells and highly detected when samplings were performed shortly after a freeze–thaw cycle. This up‐regulation of JrSUT1 level was confirmed in controlled conditions and was not obtained in bark. Immunolocalization studies showed that JrSUT1 and plasma membrane H+‐ATPase (JrAHA) were colocalized to vessel‐associated cells (VACs), which control solute exchanges between parenchyma cells and xylem vessels. We propose that JrSUT1 could be involved in the retrieval of sucrose from xylem vessel. All these data are discussed with respect to the winter biology of the walnut tree.
Decreased SBPase activity alters growth and development in transgenic tobacco plants
Authors: LAWSON T. , BRYANT B. , LEFEBVRE S. , LLOYD J. C. , RAINES C. A. 
Published: September 2005

ABSTRACTThe effects of reduced SBPase activity on growth and development were examined in a set of transgenic tobacco plants produced using an antisense construct driven by the ribulose bisphosphate carboxylase, small subunit promoter. Photosynthetic carbon assimilation rates and carbohydrate levels in source leaves were decreased in the antisense plants. Growth rate and total shoot biomass were reduced in the SBPase antisense plants, even in plants where SBPase activity was reduced by only 25%. Floral biomass also decreased in response to reductions in SBPase activity and the onset of flowering was delayed by 5–10 d. This is the first demonstration of a link between reproductive biomass and reductions in Calvin cycle enzyme activity using antisense plants. Furthermore, unexpected changes in the growth and development of the antisense plants were evident. Small reductions in SBPase activity (above 50% wild type) resulted in shorter plants with only a small decrease in stem biomass and specific leaf area. In contrast, plants with larger reductions in SBPase activity had an increase in specific leaf area and attained heights similar to that of the wild‐type plants but with a much reduced stem biomass, largely due to a decrease in xylem tissue. This bi‐modal response of growth to reductions in SBPase activity has similarities to changes in leaf and stem anatomy and morphology that accompany light acclimation.
Hydraulic redistribution in a Douglas‐fir forest: lessons from system manipulations
Authors: BROOKS J. RENÉE , MEINZER FREDERICK C. , WARREN JEFFERY M. , DOMEC JEAN‐CHRISTOPHE , COULOMBE ROB 
Published: August 2005

ABSTRACTHydraulic redistribution (HR) occurs in many ecosystems; however, key questions remain about its consequences at the ecosystem level. The objectives of the present study were to quantify seasonal variation in HR and its driving force, and to manipulate the soil–root system to elucidate physiological components controlling HR and utilization of redistributed water. In the upper soil layer of a young Douglas‐fir forest, HR was negligible in early summer, but increased to 0.17 mm day−1 (20–60 cm layer) by late August when soil water potential was approximately −1 MPa. When maximum HR rates were observed, redistributed water replenished approximately 40% of the water depleted from the upper soil on a daily basis. Manipulations to the soil or to the soil/plant water potential driving force altered the rate of observed HR indicating that the rate of HR is controlled by a complex interplay between competing soil and plant water potential gradients and pathway resistances. Separating roots from the transpiring tree resulted in increased HR, and sap flow measurements on connected and disconnected roots showed reversal of water flow, a prerequisite for HR. Irrigating a small plot with deuterated water demonstrated that redistributed water was taken up by small understorey plants as far as 5 m from the watering source, and potentially further, but the utilization pattern was patchy. HR in the upper soil layers near the watering plot was twice that of the control HR. This increase in HR also increased the amount of water utilized by plants from the upper soil. These results indicate that the seasonal timing and magnitude of HR was strongly governed by the development of water potential differences within the soil, and the competing demand for water by the above ground portion of the tree.
Precipitation of dolomite using sulphate‐reducing bacteria from the Coorong Region, South Australia: significance and implications
Authors: WRIGHT DAVID T. , WACEY DAVID 
Published: September 2005

AbstractDolomite was successfully precipitated in culture experiments that simulated microbiogeochemical conditions prevailing during late stages of evaporation in ephemeral, hypersaline dolomitic lakes of the Coorong region, South Australia. Analyses of lake‐ and pore‐water samples document rapid geochemical changes with time and depth in both dolomitic and non‐dolomitic lakes. Extremely high sulphate and magnesium ion concentrations in lake waters decline rapidly with depth in pore waters throughout the sulphate‐reduction zone, whereas carbonate concentrations in pore waters reach levels up to 100 times those of normal sea water. Ultimately, sulphate is totally consumed and no solid sulphate is recorded in the dolomitic lake sediments. ‘Most probable number’ calculations of lake sediment samples record the presence of large populations of sulphate‐reducing bacteria, whereas sulphur‐isotope analyses of lake‐water samples indicate microbial fractionation in all the lakes studied. Viable populations of microbes from the lake sediments were cultured in anoxic conditions in the laboratory. Samples were then injected into vials containing sterilized clastic or carbonate grains, or glass beads, immersed in a solution that simulated the lake water. Falls in the levels of sulphate and rising pH in positive vials were interpreted as indicating active bacterial sulphate reduction accompanied by increased concentrations of carbonate. Within 2 months, sub‐spherical, sub‐micron‐size crystals of dolomite identical to those of lake sediments were precipitated. It is concluded that bacterial sulphate reduction overcomes kinetic constraints on dolomite formation by removing sulphate and releasing magnesium and calcium ions from neutral ion pairs, and by generating elevated carbonate concentrations, in a hypersaline, strongly electrolytic solution. The results demonstrate that bacterial sulphate reduction controls dolomite precipitation in both the laboratory experiments and lake sediments. It is proposed that dolomite formation, through bacterial sulphate reduction, provides a process analogue applicable to thick platformal dolostones of the past, where benthic microbial communities were the sole or dominant colonizers of shallow marine environments.
Integration of outcrop and borehole image logs for high‐resolution facies interpretation: example from a fluvial fan in the Ebro Basin, Spain
Authors: DONSELAAR MARINUS E. , SCHMIDT JASPER M. 
Published: September 2005

AbstractElectrical borehole image logs yield high‐resolution information about variations in micro‐resistivity along the borehole wall. To interpret these variations in terms of sedimentary structures and lithofacies types, calibration with real rock is needed. Normally, the only real rock available is core, and this only provides one‐dimensional information. In this paper, the interpretation of fluvial facies types from borehole image logs was established by direct comparison with outcrops. Four fluvial facies associations were established in an outcrop study of a low net‐to‐gross fluvial succession: (i) meandering rivers, (ii) braided rivers, (iii) crevasse deltas, and (iv) crevasse splays. The lithofacies characteristics and palaeocurrent distributions of each fluvial facies association were established. Two 200 m deep wells were drilled behind the cliff face outcrops. One well was cored to a depth of 150 m and borehole image logs were recorded in both wells. The wells were correlated with the outcrop. The borehole image logs were analysed by their vertical colour succession and the dipmeter pattern. Image log facies were established, and these were interpreted in terms of the fluvial facies associations encountered in the corresponding outcrops. The study of borehole image logs yields a set of diagnostic criteria for a detailed fluvial facies interpretation and the establishment of depositional trends, and thus provides a powerful tool for the direct interpretation of fluvial facies in a reservoir setting.
Evaluation of Taenia solium and Taenia crassiceps cysticercal antigens for the serodiagnosis of neurocysticercosis
Authors: Arruda G. C. , Da Silva A. D. T. , Quagliato E. M. A. B. , Maretti M. A. , Rossi C. L. 
Published: August 2005

SummaryWe evaluated the usefulness of seven cysticercal antigen extracts, four from Taenia solium cysticerci (whole parasite‐TsoW, membrane‐TsoMe, vesicular fluid‐TsoVF and scolex‐TsoSc) and three from T. crassiceps cysticerci (whole parasite‐TcraW, membrane‐TcraMe and vesicular fluid‐TcraVF), for serodiagnosis of neurocysticercosis with an enzyme‐linked immunosorbent assay (ELISA). Cysticercus‐specific IgG were screened in serum samples from 23 patients with neurocysticercosis, 32 patients with other infections and 48 healthy persons. The best results were obtained with the TsoVF‐ELISA (91.3% sensitivity; 96.2% specificity) and TcraVF‐ELISA (91.3% sensitivity; 95% specificity). The ELISA done with whole parasite and membrane extracts from cysts of T. solium and T. crassiceps and the scolex extract from T. solium cysts showed a low performance in terms of sensitivity, ranging from 47.8% to 73.9%. None of the antigen preparations from T. solium and T. crassiceps cysticerci used in this study showed outstanding performance for the serodiagnosis of neurocysticercosis. However, considering the results obtained with the seven antigen preparations, vesicular fluid from T. solium and T. crassiceps cysticerci may be useful for detecting specific antibodies in sera from patients with neurocysticercosis.
The extracellular deposition of mast cell products is increased in hypertrophic airways smooth muscles in allergic asthma but not in nonallergic asthma
Authors: Amin K. , Janson C. , Boman G. , Venge P. 
Published: August 2005

Background:  Bronchial asthma is characterized by airways smooth muscle hypertrophy and infiltration of mast cells in the bronchial mucosa. The aim of this investigation was to study the distribution of mast cells in different compartments in the bronchial mucosa of allergic and nonallergic asthma in relation to airways remodeling.Methods:  Bronchial biopsies were obtained from 29 subjects with allergic and nonallergic asthma and healthy controls. The biopsies were stained for mast cells by means of the tryptase specific antibody AA1. Extracellular deposition of mast cell products were judged on a semi‐quantitative scale. Mast cells per mm2 were counted in epithelium, lamina propria and the smooth muscle compartment. Smooth muscle was visualized by actin antibodies and the proportion of staining of the biopsy estimated. Laminin and tenascin layers were visualized by their respective antibodies.Results:  Airways smooth muscle thickness was greater in allergic vs nonallergic asthma (P < 0.001). Mast cells were increased in all three compartments in both allergic and nonallergic asthma, with significantly higher numbers in smooth muscles in allergic asthma (P < 0.03). The extracellular deposition of mast cell products was more common in allergic than nonallergic asthma in lamina propria and smooth muscles (P = 0.025; P = 0.002, respectively). In patients with allergic asthma the numbers of mast cells with extracellular deposition of mast cell products were significantly correlated to the thickness of the laminin and tenascin layers.Conclusion:  Our results suggest that there are large differences between allergic and nonallergic asthmatics as to mast cell activation and airways smooth muscle thickness. Our data implies that mast cells are causally involved in structural alterations in allergic asthma.
Nasal nitric oxide, the guardian of paranasal sinuses, is paradoxically increased by high doses of intravenous glucocorticoids
Authors: Degano B. , Têtu L. , Serrano E. , Didier A. , Arnal J. ‐F. 
Published: August 2005

Background:  High concentrations of nitric oxide (NO) originating from a type‐2 nitric oxide synthase (NOS2) located within the paranasal sinuses are measured in nasal air in man. NO is believed to play a central role in nonspecific defense of paranasal sinuses. Glucocorticoids (GCs), a therapeutic often used for a wide range of diseases, is known to strongly downregulate NOS2.Aims of the study:  To investigate the effect of very high intravenous doses of GCs on nasal NO in man.Methods:  Nasal NO was measured in 15 patients without any history of allergy or chronic airway disorder who were treated for 3 days with a daily dose of 1000 mg methylprednisolone for an exacerbation of multiple sclerosis. Nasal NO was also measured in 30 matched control subjects.Results:  In control subjects, the maximal value of nasal NO [mean (SE)] was 233 (8) part per billion (ppb), and did not differ from patients with multiple sclerosis [maximum value: 219 (13) ppb; left nostril: 214 (12) ppb; right nostril: 215 (12) ppb]. After GCs treatment, nasal NO increased in patients [maximum value: 250 (13) ppb (P < 0.0001); left nostril: 249 (12) ppb (P < 0.0001); right nostril: 244 (13) ppb (P < 0.0001)].Conclusions:  We conclude that GCs do not decrease but even increase nasal NO.
Specific oral tolerance induction with food in children: transient or persistent effect on food allergy?
Authors: Rolinck‐Werninghaus C. , Staden U. , Mehl A. , Hamelmann E. , Beyer K. , Niggemann B. 
Published: August 2005

Background:  The standard treatment of food allergy is elimination of the incriminated food from the diet. Specific oral tolerance induction (SOTI) seems to be a promising approach for a causal treatment; however, it is unclear whether the tolerance achieved is transient or persistent. We report on a subset of three patients of a larger ongoing study who were treated successfully with SOTI treatment, but experienced a secondary loss of tolerance after a period of allergen avoidance.Methods:  The patients suffered from IgE‐mediated allergy either to cow's milk (CM) (patient A) or hen's egg (HE) (patients B and C), confirmed by double‐blind, placebo‐controlled food challenge (DBPCFC). SOTI treatment was performed at home on a daily basis until tolerance to a maximum of 250 ml CM or 4.5 g lyophilized HE protein was achieved. The daily maintenance dose was 100 ml CM or 2.5 g HE protein.Results:  Patients A, B and C reached tolerance to the maximum dose after 37, 41 and 52 weeks, respectively. According to the protocol, patients A and B performed a strict secondary elimination diet for 2 months prior to a follow‐up DBPCFC after a maintenance phase of 27 and 39 weeks, respectively. Patient C discontinued treatment for 2 days after 4 weeks on the maintenance dose. Despite previous tolerance, on re‐exposure to the allergen all patients experienced moderate systemic allergic reactions.Conclusions:  We conclude that SOTI can induce transient tolerance in food allergy, but does not necessarily lead to its permanent abrogation. Regular allergen intake seems necessary to maintain the established tolerance.