p-aminohippuric acid transport at renal apical membrane mediated by human inorganic phosphate transporter NPT1

Organic anions are secreted into urine via organic anion transporters across the renal basolateral and apical membranes. However, no apical membrane transporter for organic anions such as p-aminohippuric acid (PAH) has yet been identified. In the present study, we showed that human NPT1, which is present in renal apical membrane, mediates the transport of PAH. The K(m) value for PAH uptake was 2.66 mM and the uptake was chloride ion sensitive. These results are compatible with those reported for the classical organic anion transport system at the renal apical membrane. PAH transport was inhibited by various anionic compounds. Human NPT1 also accepted uric acid, benzylpenicillin, faropenem, and estradiol-17beta-glucuronide as substrates. Considering its chloride ion sensitivity, Npt1 is expected to function for secretion of PAH from renal proximal tubular cells. This is the first molecular demonstration of an organic anion transport function for PAH at the renal apical membrane.     

Determinants of cyanobacterial species composition in the splash zone of two Croatian islands

Cyanobacterial communities of the splash zone of two Croatian islands, Veruda and Ugljan, were surveyed. At each island, we studied eight localities with different aspects. From all 336 samples, a total of 42 cyanobacterial species, one green alga, and one red alga were found. In both islands Hyella spp. and Gloeocapsopsis crepidinum dominated and Entophysalis deusta, Solentia spp., Kyrtuthrix dalmatica and Mastigocoleus testarum were found frequently. Multivariate statistical analysis of species composition shows that the vertical gradient is the strongest determinant of species composition and that there are statistically significant but not very pronounced differences in species composition between the two islands. Species composition among individual sites within islands differed slightly, and between localities decreased rather slowly with the distance of individual samples (i.e. the similarity distance decay was very slow), showing that even close samples can have quite different species composition. The species accumulation curves do not reach their asymptote, indicating that many samples are needed to reasonably cover the species richness of a site. This study highlights the importance of in-depth species counts and high density sampling along vertical gradients for satisfactory cyanobacterial community assessments in marine coastal splash zones.     

Key Elements in a Framework for Land Use Impact Assessment Within LCA (11 pp)

Background, Aim and Scope Land use by agriculture, forestry, mining, house-building or industry leads to substantial impacts, particularly on biodiversity and on soil quality as a supplier of life support functions. Unfortunately there is no widely accepted assessment method so far for land use impacts. This paper presents an attempt, within the UNEP-SETAC Life Cycle Initiative, to provide a framework for the Life Cycle Impact Assessment (LCIA) of land use. Materials and Methods: This framework builds from previous documents, particularly the SETAC book on LCIA (Lindeijer et al. 2002), developing essential issues such as the reference for occupation impacts; the impact pathways to be included in the analysis; the units of measure in the impact mechanism (land use interventions to impacts); the ways to deal with impacts in the future; and bio-geographical differentiation. Results: The paper describes the selected impact pathways, linking the land use elementary flows (occupation; transformation) and parameters (intensity) registered in the inventory (LCI) to the midpoint impact indicators and to the relevant damage categories (natural environment and natural resources). An impact occurs when the land properties are modified (transformation) and also when the current man-made properties are maintained (occupation). Discussion: The size of impact is the difference between the effect on land quality from the studied case of land use and a suitable reference land use on the same area (dynamic reference situation). The impact depends not only on the type of land use (including coverage and intensity) but is also heavily influenced by the bio-geographical conditions of the area. The time lag between the land use intervention and the impact may be large; thus land use impacts should be calculated over a reasonable time period after the actual land use finishes, at least until a new steady state in land quality is reached. Conclusions: Guidance is provided on the definition of the dynamic reference situation and on methods and time frame to assess the impacts occurring after the actual land use. Including the occupation impacts acknowledges that humans are not the sole users of land. Recommendations and Perspectives: The main damages affected by land use that should be considered by any method to assess land use impacts in LCIA are: biodiversity (existence value); biotic production potential (including soil fertility and use value of biodiversity); ecological soil quality (including life support functions of soil other than biotic production potential). Bio-geographical differentiation is required for land use impacts, because the same intervention may have different consequences depending on the sensitivity and inherent land quality of the environment where it occurs. For the moment, an indication of how such task could be done and likely bio-geographical parameters to be considered are suggested. The recommendation of indicators for the suggested impact categories is a matter of future research.     

Sucrose effects on in vitro fruiting and seed production of Centaurium pulchellum

The effect of sucrose on fruiting, seed production, and seed germination of lesser centaury [Centaurium pulchellum (Sw.) Druce] was examined using explants of flowers and flower buds. Sucrose concentrations in the culture medium ranged from 0.003 to 0.3 M. It has been shown that the number of auxiliary buds, capsules dimension, number of viable seeds per capsule and seed dimensions increased with the increase of sucrose concentrations. The highest values were recorded at sucrose concentrations higher than 0.03 M, except for seeds size, which were larger at sucrose concentration ranging from 0.003 to 0.1 M. The germination of in vitro produced seeds was affected by previous culture history: a higher germination percentage was obtained in seeds that were raised from explants originally grown on medium with sucrose concentrations higher than 0.003 M.     

Location of cell cycle regulators cyclin B1, cyclin A, PCNA, Ki67 and cell cycle inhibitors p21, p27 and p57 in human first trimester placenta and deciduas

Although placental development and implantation depend on the coordination of trophoblast proliferation, differentiation and invasion, little is known about the cell cycle regulators that govern the control of these events. The hypothesis that the coordinated expression of cell cycle progression and inhibition factors will determine whether cytotrophoblasts proliferate or undergo cell cycle arrest or cell cycle exit allowing subsequent differentiation was tested. The cell cycle promotors cyclin A, cyclin B1, PCNA, Ki67 and the cell cycle inhibitors p21, p27 and p57 were immunolocalized in tissue sections of first trimester pregnancies (weeks 6 and 9–12). Double staining with cytokeratin 7 allowed unambiguous identification of extravillous cytotrophoblast (EVT) in the decidua. Villous cytotrophoblasts were immunolabelled for Ki67 and cyclin A but only few were stained with anti-cyclin B1. The syncytiotrophoblast was devoid of immunoreactivity for any of the cell cycle progression factors. It expressed especially p21, whereas p27 and p57 were predominantly found in villous cytotrophoblasts. PCNA, Ki67, cyclin A and cyclin B1 were immunolocalized in proximal and distal EVTs of anchoring villi and in EVT which had invaded the upper decidual segments. All EVTs strongly expressed p27 and p57, but not p21. These data clearly suggest different functions for p21, p27 and p57 in placental development with distinct roles for p21 and p57 in syncytiotrophoblast and EVT differentiation, respectively. p27 appears to be involved in both the processes. The results may also challenge the concept of differential mitotic activity in the proximal and distal parts of the first trimester cytotrophoblast cell column, but more functional studies are clearly needed. The presence of p27 and p57 in EVT cells, which invade the deciduas deeply, may account for the loss of mitogenic potential of these cells.     

Impact of abscisic acid in overcoming the problem of albinism in horse chestnut androgenic embryos

Horse chestnut (Aesculus hyppocastanum L., Hyppocastanacea) is a relict species with a slow and complex reproductive cycle considered to have horticultural and medical importance. The cycle maybe circumvented via in vitro androgenesis. Androgenesis of horse chestnut was induced in microspores and anther culture on MS media. Some of the horse chestnut androgenic embryos were albinos. Addition of abscisic acid in media (in concentrations of 0.01, 0.1, 0.5, 1, 2, 5, 10, and 20 mg l^?1) with horse chestnut androgenic embryos has circumvented the reproduction cycle barriers. The best results were achieved on medium with the lowest abscisic acid concentration (0.01 mg l^?1) in microspore culture. The microspore culture proved to be a better model system for embryo production and albino embryo reduction than anther culture. Flow cytometry analysis after maturation treatments induced by ABA showed that 88 % of green embryos originating from microspore culture were haploid. However, 50 % of green embryos from anther culture were haploid. The remaining analyzed androgenic embryos, from both types of cultures were diploid.     

Chromosome counts and chromosome morphology of some selected species

In the years 1976–1981 we studied chromosome counts and karyotypic formulae of the following 29 species of plants from 41 localities (of these 6 from Bohemia, 32 from Moravia, 3 from Slovakia):Batrachium baudotii (Godron) F. W. Schultz,Chenopodium rubrum L.,C. polyspermum L.,C. murale L.,C. ficifolium Sm.,C. opulifolium Schrader ex DC. inLam. et DC.,C. strictum Roth [subsp.strictum, subsp.glaucophyllum (Aellen)Aellen inJust etAellen, subsp.striatiforme Uotila],Arenaria grandiflora L.,Illecebrum verticillatum L.,Spergula morisonii Boreau inDuchartre,Spergularia marginata (DC. inLam. et DC.)Kittel S. marina (L.)Griseb.,S. rubra (L.) J. etC. Presl,Silene conica L.,Sisymbrium loeselii L.,S. volgense Bieb. exE. Fourn.,S. orientale L. [subsp. orientale, subsp.macroloma (A. Pomel)Dvo?ák],S. officinale (L.)Scop.,Descurainia sophia (L.)Webb exPrantl inEngler etPrantl,Nasturtium officinale R. Br. inAiton,Barbarea arcuata (Opiz inPresl J. et C.)Reichenb.,Lunaria annua L.,Soldanella montana Willd.,S. carpatica Vierh. inUrban etGraebner,Lotus tenuis Waldst. etKit. exWilld.,L. uliginosus Schkuhr,Trigonella monspeliaca L.,Geranium sibiricum L.,Lactuca tatarica (L.)C. A. Meyer.     

Vitalfärbungsversuche mit reduziertem Neutralrot an „vollen“ Zellsäften einiger höherer Pflanzen

Ohne ZusammenfassungDie vorliegenden Versuehe wurden während meines kurzen Aufenthalts im Pflanzenphysiologisehen Institut der Universität Wien ausgeführt. Herrn Prof. Dr. Karl Höfler und Herrn Dr. H. Kinzel danke ich sehönstens auch an dieser Stelle für die Untersfützung während der Arbeit.     

The Perils of Adapting to Dose Errors in Radiation Therapy

We consider adaptive robust methods for lung cancer that are also dose-reactive, wherein the treatment is modified after each treatment session to account for the dose delivered in prior treatment sessions. Such methods are of interest because they potentially allow for errors in the delivered dose to be corrected as the treatment progresses, thereby ensuring that the tumor receives a sufficient dose at the end of the treatment. We show through a computational study with real lung cancer patient data that while dose reaction is beneficial with respect to the final dose distribution, it may lead to exaggerated daily underdose and overdose relative to non-reactive methods that grows as the treatment progresses. However, by combining dose reaction with a mechanism for updating an estimate of the uncertainty, the magnitude of this growth can be mitigated substantially. The key finding of this paper is that reacting to dose errors – an adaptation strategy that is both simple and intuitively appealing – may backfire and lead to treatments that are clinically unacceptable.