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    Electronic Resource
    Selektive Partnerwahl der Aaskrähe (Corvus corone) in der Hybridisierungszone von Rabenkrähe (C. c. corone) und Nebelkrähe (C. c. cornix) (1998)
    Springer
    Journal of ornithology 139 (1998), S. 173-177 
    Details
    ISSN: 1439-0361
    Keywords: mate choice ; taxonomy ; phenotypic hybrids ; fitness ; decision rule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die als Unterarten klassifizierten europäischen Formen der Aaskrähe, Rabenkrähe und Nebelkrähe, besiedeln verschiedene, aneinandergrenzende Verbreitungsgebiete und hybridisieren in der Kontaktzone. Die Nachkommen von Mischpaaren sind fruchtbar und können sowohl mit anderen Hybriden als auch mit Raben- und Nebelkrähen erfolgreich brüten. Trotzdem kommt es zu keiner völligen Vermischung der Formen und/oder Verlagerung der Verbreitungsgebiete. Vor diesem Hintergrund untersuchten wir die Partnerwahl von Aaskrähen in der Hybridisierungszone auf der nordfriesischen Insel Amrum und stellten fest, daß Partner gleichen Phänotyps häufiger miteinander verpaart waren, als stochastisch zu erwarten gewesen wäre. Unsere Daten bestätigen vergleichbare Studien aus Hybridisierungszonen in Italien und Sibirien. Wir schließen daraus, daß phänotypisch selektive Partnerwahl bei der Aaskrähe ein allgemeines Phänomen sein könnte und diskutieren, warum dieses Verhalten anfitness-relevante Parameter gekoppelt sein sollte. Um welche es sich dabei handeln könnte, wurde bisher nicht hinreichend untersucht und muß deshalb offen bleiben.
    Notes: Summary Carrion Crow and Hooded Crow are regarded as subspecies of the Crow. They show frequent hybridisation along the adjacent borders of their distribution. Mixed pairs produce fertile offspring which are able to breed successfully with both hybrids and mates of either phenotype. However, hybridisation does not lead to phenotypic changes of Carrion and Hooded Crows in general nor in their distinct distribution. We studied the mating behaviour of Crows in the hybrid zone on the Island of Amrum (Schleswig-Holstein, Germany) and found evidence that Crows may prefer mates of the same phenotype. Our data confirm previous studies which reported assortative mating with respect to plumage coloration from hybrid zones in Italy and Siberia. We discuss why this behaviour should be related tofitness traits which in our opinion have not yet been studied adequately nor identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01651226
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  • 2
    Electronic Resource
    Electronic Resource
    Influence of cereal leaf epicuticular wax on Diuraphis noxia probing behavior and nymphoposition (1998)
    Springer
    Entomologia experimentalis et applicata 89 (1998), S. 111-118 
    Details
    ISSN: 1570-7458
    Keywords: leaf surface wax ; probing behavior ; nymphoposition ; Russian wheat aphid ; wheat ; barley ; oat ; Homoptera ; Aphididae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of cereal leaf surface wax on Diuraphis noxia (Mordvilko), the Russian wheat aphid, probing behavior and nymphoposition was evaluated. Ultrastructure of leaf epicuticular wax from wheat (Triticum aestivum L.) c.v. ‘Arapahoe’ and ‘Halt’ was different from barley (Hordeum vulgare L.) c.v. ‘Morex’, and oat (Avena sativa L.) c.v. ‘Border’. Both wheat cultivars had similar rod-shaped epicuticular wax, while barley and oat plants had flakes. The chemical composition comparison of gas chromatograms also indicated that the extract of the two wheat cultivars had similar pattern of peaks, while the barley and oat leaves had similar peaks. Cereal variety significantly affected aphid probing behavior (P 〈 0.05), but wax removal using ethyl ether swab did not (P 〈 0.05). Aphids initiated significantly more probes on Border oat leaves than on Morex barley irrespective of wax removal, although total probing duration per aphid was not significantly different among the four cereals examined. Accumulative salivation duration per aphid on oat leaves with wax was significantly longer than other cereal leaves with wax, while accumulative ingestion duration per aphid on Arapahoe wheat and Morex barley was significantly longer than on oat. Nymphoposition of D. noxia on cereal leaves maintained on the benzimidazole-agar medium showed that aphids produced a greater number of nymphs on Morex barley and less on Border oat leaves, although wax removal did not affect aphid nymphoposition. Removal of leaf epicuticular waxes from the 4 cereal genotypes using ethyl ether swab indicated that the influence of wax on plant resistance to D. noxia probing and reproduction was limited. Morex barley was the most favorable, while Border oat was the least favorable cereal host of D. noxia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003458406502
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  • 3
    Electronic Resource
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    Electrochemical characterization of Fe-Ni-P alloy electrodeposition (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 1198-1206 
    Details
    ISSN: 1572-8838
    Keywords: alloy ; amorphous ; anomalous ; hydrogen ; iron ; nickel ; phosphorus ; plating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this study we have investigated the electrodeposition of amorphous iron–nickel–phosphorus alloys from a sulfate electrolyte. Fe-Ni alloys are known to exhibit an ’anomalous‘ type of plating behaviour in which deposition of the less noble metal is favoured. We have found that the codeposition of phosphorus from hypophosphite in the electrolyte led to a reversal to a ’normal‘ behaviour. This reversal was due both to the suppression of iron and enhancement of nickel partial currents. The overall deposition process is dominated by the hydrogen evolution reaction. This is exacerbated by the low pH needed to codeposit sufficient phosphorus to achieve an amorphous structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018475718629
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  • 4
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    Surface acid property and its relation to SCR activity of phosphorus added to commercial V2O5(WO3)/TiO2 catalyst (1998)
    Springer
    Catalysis letters 53 (1998), S. 65-71 
    Details
    ISSN: 1572-879X
    Keywords: selective catalytic reduction ; nitric oxide reduction ; phosphorus ; acid property
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract To examine the influence of phosphorus on the commercial V2O5(WO3)/TiO2 SCR catalyst, measurements were carried out by means of infrared and Raman spectroscopy, XPS, and NO reduction measurement as a function of phosphorus loading. Phosphorus added to the catalyst was found to disperse well over the catalyst without a significant agglomeration up to 5 wt% P2O5 addition. The number of the hydroxyl groups bonded to the vanadium and titanium species decreased readily with increasing amount of phosphorus. Correspondingly, the hydroxyl groups bonded to the phosphorus species were formed. NH3 adsorbed on both hydroxyl groups bonded to vanadium and phosphorus as ammonium ions, implying that the P–OH groups formed are also responsible for the Brønsted acidity. The NO reduction activity was found to be decreased with increasing amount of phosphorus; however, the influence of phosphorus was relatively small irrespective of the large amount of phosphorus addition. The deactivation might be caused by the change in the nature of the surface hydroxyl groups as Brønsted acid sites. Phosphorus species might partially wrap the surface V=O and W=O groups, which might also contribute to the deactivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019020931117
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  • 5
    Electronic Resource
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    Variability of diatom-inferred phosphorus profiles in a small lake basin and its implications for histories of lake eutrophication (1998)
    Springer
    Journal of paleolimnology 20 (1998), S. 47-55 
    Details
    ISSN: 1573-0417
    Keywords: diatoms ; spatial variability ; canonical correspondence analysis ; lake eutrophication ; transfer functions ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Diatom analyses were undertaken of sediment cores covering a range of water depths in a small eutrophic lake (Lough Augher, Co. Tyrone, N. Ireland). The significance of between-core variability in diatom relative frequency stratigraphy was assessed by Canonical Correspondence Analysis (CCA) where the ordination axes were constrained to external environmental variables (sediment depth, core location coordinates, water depth, effective fetch, distance-from-shore and distance-from-inflow). After the removal of the effect of sediment age by partialling it out, the resultant first two axes from the partial-CCA were significantly correlated with water depth and distance-from-shore, indicating non-uniform diatom stratigraphies across the lake. Despite this variability, all cores show the same succession of species and, therefore, record the eutrophication of the lake. Diatom-inferred total phosphorus (DI-TP) was inferred for six cores using weighted averaging regression and calibration. Apart from considerable differences of DI-TP in surficial sediment samples, there was good between-core repeatability of DI-TP profiles. These data support the use of DI-TP for establishing background nutrient concentrations for lakes, and associated implications for lake restoration schemes using single cores. Comparisons of DI-TP profiles and total diatom accumulation rate data for the individual cores indicate that diatom production peaked prior to the maximum TP concentrations in the lake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007923813511
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  • 6
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    Modern and historic accumulation rates of phosphorus in Lake Okeechobee, Florida (1998)
    Springer
    Journal of paleolimnology 20 (1998), S. 31-46 
    Details
    ISSN: 1573-0417
    Keywords: phosphorus ; Lake Okeechobee ; lead-210 dating ; eutrophication ; phosphorus loading
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Phosphorus accumulation rates in depositional zone sediments of Lake Okeechobee were determined in 11 mud-zone cores and two peat-zone cores dated by 210Pb. Although difficulties were encountered in interpreting 210Pb data from some sites, reliable dating of sediments from the mud zone of this shallow lake is possible. Sediment accumulation rates in this zone have increased during the present century by an average of about twofold, and accumulation of organic sediments in the lake during pre-settlement times apparently was much slower than during the past century. Concentrations of all forms of sedimentary P but especially nonapatite inorganic-P and organic-P also have increased since pre-settlement times and especially since about 1940. Annual P accumulation rates in the lake's sediments have increased about fourfold during the 1900s, with most of the increase occurring in the past 40–50 years. The recent accumulation rate of sedimentary P (past ~ 10 years) agrees within a factor of 1.5 with the net retention of P in the lake calculated from published input-output mass balances.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007939714301
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  • 7
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    Identity of Fusarium nygamai isolates with long and short microconidial chains from millet, sorghum and soil in Africa (1997)
    Springer
    Mycopathologia 140 (1997), S. 171-176 
    Details
    ISSN: 1573-0832
    Keywords: Africa ; Fusarium ; F. moniliforme ; grain ; Lesotho ; mating population ; Nigeria ; taxonomy ; Zimbabwe
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Several Fusarium species have been found associated with millet and sorghum in Nigeria, Lesotho and Zimbabwe. Amongst these, some isolates were originally identified as short- and long-chained types of F. nygamai. However, there was some question as to the correct identification of the long chained types. This study reclassified some of the isolates with long microconidial chains as F. moniliforme. Morphologically, these strains do not produce chlamydospores like F. nygamai, but produce swollen hyphal cells or resistant hyphae. The isolates in this study were crossed with the mating-type tester strains of Gibberella fujikuroi (F. moniliforme and G. nygamai (F. nygamai). Of the isolates with long chains of microconidia and other characteristics of F. moniliforme, 36% crossed with mating population ''A'' of G. fujikuroi. Of the isolates with characteristics of F. nygamai, 65% crossed with the testers used to produce the teleomorph of F. nygamai. Mating tests support the separation of the sample population into F. moniliforme and F. nygamai. The results of this study show that genetics can be an aid in resolving some problems in fungal taxonomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006863825469
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  • 8
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    A survey on the occurrence of mycotoxins in wheat and maize from western Romania (1998)
    Springer
    Mycopathologia 143 (1998), S. 97-103 
    Details
    ISSN: 1573-0832
    Keywords: deoxynivalenol ; enzyme immunoassay ; feed ; maize ; mycotoxins ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Samples of wheat (n = 25) and maize (n = 30) for animal consumption, collected in 1997 after harvest from western Romania, were analyzed by enzyme immunoassays for mycotoxin contamination. Toxins analyses included deoxynivalenol (DON), 3-acetylDON, 15- acetylDON, fusarenone X (FX), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), zearalenone (ZEA), fumonisin B1 (FB1), aflatoxin B1 (AFB1), ochratoxin A (OA), and citrinin (CT). DON and acetylDONs were the major contaminants in wheat (100%) and maize (46%). Median values for DON, 3-acetylDON, and 15-acetylDON were 880 μg kg-1, 66 μg kg- 1, and 150 μg kg-1 in wheat, and 890 μg kg-1, 180 μg kg-1, and 620 μg kg- 1 in maize, respectively. Additionally, 3,15-diacetylDON was detected in some samples by HPLC-EIA analysis. All samples were negative for FX (〈150 μg kg-1). T-2 was found in wheat (n = 6) and maize (n = 1) at levels between 13 and 63 μg kg- 1. DAS (2.6 μg kg-1) was found in one maize sample. ZEA occurred in all wheat and in four maize samples, median values were 10 μg kg-1 and 250 μg kg-1, respectively. One maize sample contained FB1 (140 μg kg-1). All samples were AFB1-negative (〈4 μg kg-1). OA was found in one wheat sample (37 μg kg- 1), CT was found in one maize sample (580 μg kg- 1). This first reported natural occurrence of a range of mycotoxins in Romanian feeding stuff shows that DON and acetyl DONs may be present at levels which may affect animal production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006987205986
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  • 9
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    Leaching of nitrogen and phosphorus from rural areas to surface waters in the Netherlands (1998)
    Springer
    Nutrient cycling in agroecosystems 50 (1998), S. 321-324 
    Details
    ISSN: 1573-0867
    Keywords: nutrient modelling ; leaching ; nitrogen ; phosphorus ; schematization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In context of preparing the Fourth National Policy Document on Water Management in the Netherlands effects of different scenarios of fertilizer management on nitrogen (N) and phosphorus (P) leaching from rural areas into Dutch surface waters were analyzed. The manuscript offers insight into the model instrument that is used to simulate the different scenarios. Main parts of the modelinstrument are: a procedure to schematize the Netherlands in horizontal areal units, field scale mechanistic models for water and nutrient behaviour in the soil and an empirical model for fertilizer additions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009773202654
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  • 10
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    Changes in fertilizer and manurial practices during 1960–1990: implications for N and P inputs to the Ythan catchment, N.E. Scotland (1998)
    Springer
    Nutrient cycling in agroecosystems 52 (1998), S. 19-29 
    Details
    ISSN: 1573-0867
    Keywords: agriculture ; catchment ; fertilizer ; historical ; manure ; nitrate ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A suggested increase in the growth of macrophytic algae within the Ythan estuary (N.E. Scotland) over recent years has been linked to the increased amounts of nitrogen in the form of NO3–N entering the estuary from the river. The increased NO3 concentration in the river has been associated with recent changes in farming practices in this predominantly agricultural catchment. Terrestrially derived phosphorus is also considered to contribute increasingly to eutrophication of fresh waters. Historical agricultural census data together with appropriate surveys of fertilizer practice were used to calculate the total quantities of fertilizer and manure derived N and P applied annually over the wholeYthan catchment during the period 1960 – 1990. While the total agricultural land area has remained similar, significant changes in cropping practice have occurred. In particular, a greater proportion of land is given to autumn sown crops while the area of grassland has declined. These changes in farming practice are associated with differences in both the total amounts and timing of fertilizer applied. The use of inorganic N in the catchment has trebled since 1960 and is currently approximately 6400 tonnes (104 kg N/ha). The use of P has decreased by more than a quarter to 1274 tonnes (21 kg P/ha) over a similar time period. There has been no obvious change in total quantity of N and P derived from animal manures, estimated to be 44 and 11 kg per ha, respectively, when averaged over the area of agricultural land. Cattle and sheep numbers have remained relatively constant and together account for approximately 80% of the manure N and 70% of the manure P produced annually. However, poultry have declined by 70% since 1960 while pig numbers have increased six-fold. The average annual application rate of manure derived N over the whole catchment (44 kg/ha) is considerably below that proposed at the farm scale in the EC Nitrate Directive (210–170 kg/ha). However, on a local scale difficulties may arise for large manure producing concerns such as dairy or pig units.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009787618943
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  • 11
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    Candida novakii, sp. nov. a new anamorphic yeast species of ascomycetous affinity (1997)
    Springer
    Antonie van Leeuwenhoek 71 (1997), S. 375-378 
    Details
    ISSN: 1572-9699
    Keywords: Candida novakii ; taxonomy ; yeasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two strains of an undescribed species of the genus Candida were isolated from decaying wood of Quercus sp. A description of the new species Candida novakii is given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000238205640
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  • 12
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    Verrucomicrobia div. nov., a new division of the Bacteria containing three new species of Prosthecobacter (1997)
    Springer
    Antonie van Leeuwenhoek 72 (1997), S. 29-38 
    Details
    ISSN: 1572-9699
    Keywords: phylogeny ; prosthecobacter ; taxonomy ; Verrucomicrobia ; Verrucomicrobiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Four strains of nonmotile, prosthecate bacteria were isolated in the 1970s and assigned to the genus Prosthecobacter. These strains were compared genotypically by DNA/DNA reassociation and 16S rDNA based phylogenetic analyses. Genotypic comparisons were complemented with phenotypic characterizations. Together, these studies clearly indicate each Prosthecobacter strain represents a novel species of bacteria. We propose three new species of Prosthecobacter, P. dejongeii strain FC1, P. vanneervenii strain FC2, and P. debontii strain FC3; P. fusiformis is reserved for the type strain of the genus, strain FC4. Additionally, we propose the genera Prosthecobacter and Verrucomicrobium, currently members of the order Verrucomicrobiales, to comprise a novel higher order taxonomic group, the division Verrucomicrobia div. nov. and the class Verrumicrobiae class nov. Many novel members of the Verrucomicrobia, as revealed by molecular ecology studies, await isolation and description.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000348616863
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  • 13
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    Studies on keratinophilic fungi. Ix: Neoarachnotheca gen. nov. and a new species of Nannizziopsis (1997)
    Springer
    Antonie van Leeuwenhoek 72 (1997), S. 149-158 
    Details
    ISSN: 1572-9699
    Keywords: keratinophilic fungi ; Neoarachnotheca ; Neoarachnotheca keratinophila ; Nannizziopsis tropicalis ; Onygenales ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Neoarachnotheca is proposed as a new genus of Onygenales. The outstanding generic characteristics are white, spherical ascomata with a wall formed by a network of hyphae and spherical, subhyaline ascospores with an irregular sheath. Nt. keratinophila, the type species, characterized by wavy peridial hyphae has been isolated from marine and river sediments and Myriodontium keratinophilum is its anamorph. Nannizziopsis tropicalis is proposed as a new species based on a strain isolated from soil in Burundi. RFLPs analysis of ITS and 5.8S rDNA support these proposals. The differences with related genera are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1000394118040
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  • 14
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    Use of a lux-based procedure to rapidly visualize root colonisation by Pseudomonas fluorescens in the wheat rhizosphere (1997)
    Springer
    Antonie van Leeuwenhoek 72 (1997), S. 365-372 
    Details
    ISSN: 1572-9699
    Keywords: bioluminescence ; Pseudomonas ; root colonization ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The bioluminescently marked Pseudomonas fluorescens strain 5RL, has been used previously to follow colonisation of soy bean roots (De Weger et al. [1991] Appl. Environ. Microbiol. 57:36-41). In the present paper the method has been further developed and optimized for wheat roots and it is used to get a quick overview of the colonisation patterns of many different root systems at the same time. Colonisation was followed on wheat plants grown in our gnotobiotic sand system (Simons et al., 1996. Mol Plant Microbe Interact 9: 600–607) and the following results were obtained. (i) A spatio-temporal analysis of the colonisation of wheat roots showed that 4 days after planting the highest bacterial activity was observed at the upper part of the root. After 6 days the high bacterial activity at the upper part was further increased, whereas spot-like activities were observed on the lower root parts, possibly due to micro-colonies. (ii) Bacterial mutations causing lack of motility or auxotrophy for amino acids resulted in impaired colonisation of the lower root parts, indicating that motility and prototrophy for the involved amino acid(s) are important factors for wheat root colonisation by strain 5RL. (iii) Coinoculation of strain 5RL with other wild type Pseudomonas strains on the root influenced the colonisation pattern observed for strain 5RL. Colonisation was not visually affected when the competing strain was a poor root coloniser, but was severely reduced when the competing strain was a good root coloniser. The results show that the spatio-temporal colonisation of wheat root by P. fluorescens strain 5RL and derivatives is similar to that of strain WCS365 on tomato. The advantage of the use of lux-marked strains is that the results are obtained much quicker than when conventional methods are used and that the result is supplied as an image of the colonisation pattern of many different roots.
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    URL: http://dx.doi.org/10.1023/A:1000565413024
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  • 15
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    Dipodascus capitatus, Dipodascus spicifer and Geotrichum clavatum: Genomic characterization (1998)
    Springer
    Antonie van Leeuwenhoek 74 (1998), S. 229-235 
    Details
    ISSN: 1572-9699
    Keywords: Dipodascus capitatus ; D.spicifer ; Geotrichum clavatum ; yeast ; taxonomy ; DNA heterogeneity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The G+C contents of 25 strains of Dipodascus capitatus, Dipodascus spicifer and Geotrichum clavatum were found to be heterogeneous on basis of derivative graphs of the melting profiles. Strains showing similar derivative graphs of the melting curve exhibited high levels of DNA homology (80-100%); strains showing dissimilar derivative graphs exhibited low levels of DNA homology (5 to 45%). Being considered separate taxa on basis of these parameters, D. capitatus, D. spicifer and G. clavatum could be identified by a combination of the key characteristics growth on xylose, cellobiose, salicin and arbutin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1001762024710
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  • 16
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    Identification of Taxa in the Genus shape Beta using ITS1 Sequence Information (1998)
    Springer
    Plant molecular biology reporter 16 (1998), S. 147-155 
    Details
    ISSN: 1572-9818
    Keywords: allele-specific PCR ; Beta ; ITS1 ; plant identification ; rDNA ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sequence variation in the ITS1 locus of the nuclear ribosomal DNA in beets has previously been used to reconstruct phylogeny of the species in the genus Beta. We have developed protocols that allow the identification of Beta taxa by use of taxon-specific primers. Beta sections, species and subspecies can be identified. Differences within the ITS1 region of a single base can be exploited for species identification. The results from this study not only provide effective methods for wild beet identification, but also indicate the potential use of the techniques in other crops.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007416817736
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  • 17
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    The taxonomic impediment in orthopteran research and conservation (1998)
    Springer
    Journal of insect conservation 2 (1998), S. 151-159 
    Details
    ISSN: 1572-9753
    Keywords: Orthoptera ; biodiversity ; taxonomy ; conservation.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract It is estimated that only 10–15% of the world's insect fauna has been described and named. Efforts to inventory insect biodiversity are hampered by this taxonomic impediment, which is compounded by the logistical problems of an insufficient taxonomic workforce and their remote location in museums thousands of miles from the areas of highest biodiversity. Compared to most other invertebrate groups however, the taxonomic impediment is relatively benign in the order Orthoptera. This is a small to medium-sized order (approximately 20 000 described species) which is well known taxonomically, owing to the group's agricultural importance worldwide. Furthermore, orthopteran taxonomists are now fortunate to have a published up-to-date catalogue of all known species, which has just become accessible as a regularly updated database on the World Wide Web. Whilst new information technology, in the form of e-mail networks, World Wide Web sites and CD-ROM information archives, is already enhancing communication between specialists and helping to reduce the logistical problems of documenting orthopteran biodiversity, a major reinvestment in basic taxonomic research is needed if we are to reduce the existing taxonomic impediment significantly. There is general agreement that an internationally coordinated approach will be necessary and priorities must be set to tackle the biodiversity/systematics crisis. In the future, the Orthoptera can make an important contribution to invertebrate faunal surveys and have potential as an indicator taxon. Furthermore, the Orthoptera Species File establishes a taxonomic framework which could be readily enlarged to include geographic data and phenology of species from existing museum specimens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009633811789
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    Distribution and fluxes as macrodetritus of phosphorus in red mangroves, Sepetiba Bay, Brazil (1998)
    Springer
    Mangroves and salt marshes 2 (1998), S. 37-42 
    Details
    ISSN: 1572-977X
    Keywords: mangrove ; phosphorus ; distribution ; dynamics ; exportation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The distribution and dynamics of phosphorus have been studied in the mangroves of Sepetiba Bay, Brazil. Leaf fall contributes 3.0 kg P ha=1yr=1to the sediment. The total above ground biomass of the R. mangle stand was about 65.3 t ha=1, the P accumulation was 3.9 kg P ha=1where 63% of the total P-biomass was accumulated in the leaves. The biomass of below ground roots was about 8.2 tha=1 and accumulated 16% of total P-biomass. Sediment contained 452 kg P ha=1 where P combined with calcium (P-Ca) was the main fraction (260 kg ha=1). The annual flux of P as litter fall was small (〈 1%) compared to total P in the sediment reservoir. The annual export of P by macrodetritus corresponds to 0.05% of the total sediment reservoir.
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    URL: http://dx.doi.org/10.1023/A:1009950708155
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    Biological control of pigweeds (Amaranthus retroflexus, L. A. Powellii, S. Watson and A. bouchonii Thell.) with phytophagous insects, fungal pathogens and crop management (1997)
    Springer
    Integrated pest management reviews 2 (1997), S. 51-59 
    Details
    ISSN: 1572-9745
    Keywords: Biological control ; insects ; pathogens ; germination ; taxonomy ; genetic variability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Pigweeds (Amaranthus spp.) are of economic importance worldwide. In Europe, Amaranthus retroflexus is one of the ten weed species of greatest economic importance. It is a serious problem weed in several field crops (e.g. maize), as well as in vegetables, orchards and grape vines. It is an annual spreading by seeds which have a long viabilityand are dispersed principally by wind and water, but also by machinery. There is great variability in seed germination which renders control with post-emergence herbicides difficult. In addition, triazine herbicide-resistant populations occur in ten European countries. The aim of this subproject of COST action 816 is to investigate the possibilities of classical and inundative biological control of Amaranthus spp., to characterize potentialbiological control agents and to develop methods for their integration with current phytosanitary measures in the target crops. The project was initiated with an extended literaturesurvey followed by field surveys for insects and pathogens associated with Amaranthus spp. in several European countries. Promising isolates of fungal pathogens have been tested ondetached leaves and whole plants, and initial studies on the application of pathogens causing damping off in seedlings have been made. Further, the variability of different provenances ofAmaranthus spp. in response to fungal attack has been investigated
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    URL: http://dx.doi.org/10.1023/A:1018480429706
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    Distribution and sources of phosphorus in tidal river sediments in the Washington, DC, Area (1997)
    Springer
    Environmental geology 30 (1997), S. 224-230 
    Details
    ISSN: 1432-0495
    Keywords: Key words Sediment ; Washington ; DC ; Pollution ; phosphorus ; nutrients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Sediments in the rivers and basins around Washington, DC, have high concentrations of phosphorus, which, based on geographic distributions, is largely derived from urban runoff and municipal sewage. Dissolved-particulate phosphate exchange reactions and biological uptake of dissolved phosphorus from the water column may be an added source of phosphorus to the sediments. Concentrations of total sedimentary phosphorus ranged from 24 to 56 μm P/g-dw, and were highest in areas near combined sewer outfalls. As a part of this study, sedimentary phosphorus was fractionated into Fe-P, Ca-P, Al-P, and organic phases using a selective-sequential leaching procedure. The distribution of the phases in all sediments analyzed follow the order , Fe-P〉Ca-P〉Al-P. Spatial variations in the amounts of phosphorus in the different phases is related to the sources of phosphorus to the area. The proportions of occluded Al-P and organic P are 10–20% of the total P, respectively. This suggests that phosphorus from natural sources is small compared to anthropogenic inputs in this area. The high leachable Fe-P and Ca-P in these sediments might contribute a substantial amount of P to the water column under conditions of remobilization.
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    URL: http://dx.doi.org/10.1007/s002540050150
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    Influence of an acidic beverage (Coca-Cola) on the absorption of itraconazole (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 235-237 
    Details
    ISSN: 1432-1041
    Keywords: Key words Itraconazole ; Coca Cola; acidic beverage ; absorption ; pharmacokinetics ; drug concentration ; food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: To evaluate the effectiveness of Coca-Cola in enhancing the absorption of itraconazole. Methods: Eight healthy volunteers were randomized to receive two treatment sequences in a two-way crossover design with a 1-week wash-out period separating each study treatment. Treatment I, the control, consisted of 100 mg itraconazole with 325 ml water. Treatment II was identical to treatment I, except that itraconazole was administered with 325 ml of Coca-Cola (pH 2.5). Results: Serum itraconazole concentrations, after administration with Coca-Cola (treatment II), were higher than after administration with water (treatment I). The mean AUC was 1.12 vs 2.02 μg · h · ml−1, the mean Cmax was 0.14 vs 0.31 μg · ml −1and the mean tmax was 2.56 vs 3.38 h in treatments I and II, respectively. Conclusion: The absorption of itraconazole can be enhanced by Coca-Cola.
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    URL: http://dx.doi.org/10.1007/s002280050280
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    Pharmacokinetics of nicardipine enantiomers in healthy young volunteers (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 289-292 
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    ISSN: 1432-1041
    Keywords: Key words Nicardipine; enantiomers ; healthy volunteers ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objectives: The present study was conducted to compare pharmacokinetic behaviors of nicardipine enantiomers given in different doses with different formulations of racemic nicardipine in healthy volunteers. Methods: One or two 20-mg racemic nicardipine tablets, and a 40-mg sustained-release capsule of nicardipine were administered to eight healthy volunteers in a cross-over fashion and pharmacokinetic parameters were evaluated. Enantiomer concentrations were determined by GC-MS combined with chiral stationary phase HPLC. Results and conclusions: Serum concentration of (+)-nicardipine was approximately 2–3 times higher than that of (−)-nicardipine in 20- and 40-mg doses of conventional formulations and a non-linear increase in bioavailability with dose was demonstrated. The value for AUC of (+)-nicardipine was approximately 2.3–2.8 times greater than that of the (−)-nicardipine (P 〈 0.05) when 20 and 40 mg racemic nicardipine were administered in a conventional preparation. Relative bioavailability of the sustained-release preparation vs the conventional preparation was 28% and 44% for (+)- and (−)-nicardipine, respectively, for the 40-mg dose.
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    URL: http://dx.doi.org/10.1007/s002280050292
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  • 23
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    Transdermal nitroglycerin: clinical and pharmacokinetic consequences of renewing the patch and the application site (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 379-381 
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    ISSN: 1432-1041
    Keywords: Key words Nitroglycerin; transdermal nitrate ; pharmacokinetics ; patch renewal ; exercise test
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: We examined whether nitroglycerin (glyceryl trinitrate, GTN) patch treatment for 24 h could induce local cutaneous changes that impaired drug delivery and clinical efficacy. Methods: Twenty angina patients were exercise-tested after 2 and 24 h of treatment and then 2 h after patch renewal. The patch was either renewed on a new skin location or on the previous application site in a randomised, double-blind, cross-over protocol. GTN plasma concentrations and finger plethysmography were obtained before and after each exercise test. Results and conclusions: The clinical efficacy, the effect seen on plethysmography and the GTN plasma concentrations tended to increase after patch renewal, regardless of the application site of the renewed patch. Hence, cutaneous changes of clinical importance could not be demonstrated.
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    URL: http://dx.doi.org/10.1007/s002280050304
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    Pharmacokinetics and pharmacodynamic effects of the angiotensin II antagonist valsartan at steady state in healthy, normotensive subjects (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 441-449 
    Details
    ISSN: 1432-1041
    Keywords: Key words Angiotensin II ; Valsartan; AT1 receptor antagonist ; healthy volunteers ; pharmacokinetics ; renin-angiotensin system ; blood pressure ; passive tilting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Pharmacokinetics, pharmacodynamic effects and tolerability of 200 mg valsartan, once-daily for 8 days, were investigated in 16 healthy, normotensive volunteers on a normal sodium diet. Methods: This was a double-blind, placebo-controlled, randomized crossover study. Drug concentrations in plasma and urine, angiotensin II (Ang II) concentrations in plasma, systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR) in the supine position and 3 min after passive head-up tilting, as well as safety parameters (ECG, clinical chemistry and hematology, renal water and electrolyte excretion) were measured over 24 h after the first dose (day 1) and at steady state on day 8. Results: Absorption and distribution of valsartan were rapid (Cmax, 2 h; t½λ1 〈 1 h), followed by a slower terminal elimination phase (t½λ2, 6 h) on days 1 and 8, with little accumulation in plasma (increase of 20% on day 8). Less than 10% of the dose was excreted unchanged in urine. The increase in plasma Ang II (Cmax, 6 h) was significantly enhanced at steady state. Supine SBP and DBP significantly decreased on day 8 only, by an average of −3.6 and −2.4 mmHg, respectively, versus placebo, without a concomitant increase in HR. Upon passive tilting, the increase in DBP, normally reinforced by sympathetic renin release, was slightly but significantly blunted on day 1 (−2.0 mmHg) and day 8 (−4.0 mmHg) of treatment with valsartan versus placebo. The orthostatic reflex increase in HR was slightly enhanced compared with placebo by an average of 2.8 beats · min−1 on day 1 and by 2.9 beats · min−1 on day 8. Valsartan was well tolerated and had no influence on ECG, clinical laboratory parameters, and water, electrolyte and uric acid excretion. Conclusions: Pharmacokinetics of valsartan are unchanged after multiple once-daily dosing, with little (expected) accumulation in plasma. Effects of 200 mg valsartan on blood pressure in healthy subjects on a normal sodium intake are small and become more prominent after repeated dosing. Indirect evidence of AT1 blockade by valsartan is demonstrated by an increase of plasma Ang II and by a blunted DBP response to passive tilting. The decrease in blood pressure at steady state enhances the increase in plasma Ang II. Valsartan is well tolerated and is devoid of effects on water, electrolyte and uric acid excretion at 200 mg per day in healthy normotensive volunteers.
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    URL: http://dx.doi.org/10.1007/s002280050317
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    Cardiovascular effects of different infusion rates of sufentanil in patients undergoing coronary surgery (1997)
    Springer
    European journal of clinical pharmacology 51 (1997), S. 359-366 
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    ISSN: 1432-1041
    Keywords: Key words Sufentanil ; pharmacokinetics ; haemo dynamics ; different infusion rates ; coronary surgery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract    Objective: Pharmacokinetics and haemodynamic effects of a total dose of 15 μg · kg−1 sufentanil, an opioid anaesthetic agent, were studied in patients undergoing aortocoronary bypass surgery at three infusion rates of 30 (group I), 5 (group II), and 2 (group III) μg · kg−1 · min−1, respectively. Results: Plasma concentrations of sufentanil could be optimally characterized by a linear biexponential pharmacokinetic model. Non-compartmental analyses indicated that there was no significant difference in the values of clearance (11.6, 13.3, 14.3 ml · min−1 · kg−1), steady-state volume of distribution (0.220, 0.255 and 0.331 l · kg−1) and mean residence time (18.8, 13.3 and 14.3 min) among the groups. The observed mean Cmax values of 421 (group I), 125 (group II), and 53 (group III) ng · ml−1 and observed mean AUC values from 0 to 3 min were all consistent with the dosing regimens. There were large inter-individual variations in haemodynamic response. Compared to plasma data, a delay in haemodynamic effects was found. Times to reach peak haemodynamic effect ranged from 4.3 to 4.9 min for group I, from 4.6 to 6.1 min for group II, and from 9.9 to 11.3 for group III. Except heart rate, peak haemodynamic effects in these study patients generally ranged from 20.9% to 35.2%. Significant reductions in the area under the effect-time profiles of mean arterial blood pressure and systemic vascular resistance were observed in group II and group III, but not in group I. Significant reductions in the area under the effect-time profiles of left ventricular stroke work index were observed in group III only. No effect on heart rate was found in any group. Conclusion: Our findings suggested that a slower infusion rate of sufentanil at a dose of 15 μg · kg−1 tends to give a greater reduction in mean arterial blood pressure, systemic vascular resistance, and left ventricular stroke work index than does a faster infusion rate.
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    Effect of route of administration of fluconazole on the interaction between fluconazole and midazolam (1997)
    Springer
    European journal of clinical pharmacology 51 (1997), S. 415-419 
    Details
    ISSN: 1432-1041
    Keywords: Key words Midazolam ; Fluconazole ; CYP3A4 ; interaction ; pharmacokinetics ; pharmacodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Midazolam is a short-acting benzodiazepine hypnotic extensively metabolized by CYP3A4 enzyme. Orally ingested azole antimycotics, including fluconazole, interfere with the metabolism of oral midazolam during its absorption and elimination phases. We compared the effect of oral and intravenous fluconazole on the pharmacokinetics and pharmacodynamics of orally ingested midazolam. Methods: A double-dummy, randomized, cross-over study in three phases was performed in 9 healthy volunteers. The subjects were given orally fluconazole 400 mg and intravenously saline within 60 min; orally placebo and intravenously fluconazole 400 mg; and orally placebo and intravenously saline. An oral dose of 7.5 mg midazolam was ingested 60 min after oral intake of fluconazole/placebo, i.e. at the end of the corresponding infusion. Plasma concentrations of midazolam, α-hydroxymidazolam and fluconazole were determined and pharmacodynamic effects were measured up to 17 h. Results: Both oral and intravenous fluconazole significantly increased the area under the midazolam plasma concentration-time curve (AUC0–3, AUC0–17) 2- to 3-fold, the elimination half-life of midazolam 2.5-fold and its peak concentration (Cmax) 2- to 2.5-fold compared with placebo. The AUC0–3 and the Cmax of midazolam were significantly higher after oral than after intravenous administration of fluconazole. Both oral and intravenous fluconazole increased the pharmacodynamic effects of midazolam but no differences were detected between the fluconazole phases. Conclusion: We conclude that the metabolism of orally␣administered midazolam was more strongly inhibited by oral than by intravenous administration of fluconazole.
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    URL: http://dx.doi.org/10.1007/s002280050223
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    Lack of interaction between meloxicam and warfarin in healthy volunteers (1997)
    Springer
    European journal of clinical pharmacology 51 (1997), S. 421-425 
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    ISSN: 1432-1041
    Keywords: Key words Warfarin ; Meloxicam ; interaction ; pharmacokinetics ; protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The effect of multiple oral doses of meloxicam 15 mg on the pharmacodynamics and pharmacokinetics of warfarin was investigated in healthy male volunteers. Warfarin was administered in an individualized dose to achieve a stable reduction in prothrombin times calculated as International Normalized Ratio (INR) values. Then INR- and a drug concentration-time profile was determined. For the interaction phase, meloxicam was added for 7 days and then INR measurements and the warfarin drug profiles were repeated for comparison. Overall, warfarin treatment lasted for 30 days. Results: Warfarin and meloxicam were well tolerated by healthy volunteers in this study. Thirteen healthy volunteers with stable INR values entered the interaction phase. Prothrombin times, expressed as mean INR values, were not significantly altered by concomitant meloxicam treatment, being 1.20 for warfarin alone and 1.27 for warfarin with meloxicam cotreatment. R- and S-warfarin pharmacokinetics were similar for both treatments. Geometric mean (% gCV) AUCSS values for the more potent S-enantiomer were 5.07 mg · h · l−1 (27.5%) for warfarin alone and 5.64 mg · h · l−1 (28.1%) during the interaction phase. Respective AUCSS values for R-warfarin were 7.31 mg · h · l−1 (43.8%) and 7.58 mg · h · l−1 (39.1%). Conclusion: The concomitant administration of the new non-steroidal anti-inflammatory drug (NSAID) meloxicam affected neither the pharmacodynamics nor the pharmacokinetics of a titrated warfarin dose. A combination of both drugs should nevertheless be avoided and, if necessary, INR monitoring is considered mandatory.
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    URL: http://dx.doi.org/10.1007/s002280050224
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    Genetic polymorphism of CYP2C19 and lansoprazole pharmacokinetics in Japanese subjects (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 391-396 
    Details
    ISSN: 1432-1041
    Keywords: Key words Lansoprazole ; CYP2C19; genotype ; hydroxy lation ; polymorphism ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: We investigated whether interindividual differences in the pharmacokinetic disposition of lansoprazole are attributed to the genetic polymorphism of CYP2C19 which occurred by two mutations, CYP2C19m1 and CYP2C19m2, in 20 Japanese subjects. Methods: Polymerase chain reaction (PCR) restriction fragment length polymorphism procedures were used to detect the CYP2C19m1 mutation in exon 5 and the CYP2C19m2 mutation in exon 4 using SmaI and BamHI, respectively. Results: Ten subjects were homozygous (wt/wt subjects) for the wt allele in both exon 5 and exon 4, four subjects were heterozygous (wt/m1) for the CYP2C19m1 mutation, and two subjects were heterozygous (wt/m2) for the CYP2C19m2. The remaining four subjects had both mutated alleles in CYP2C19 genes, i.e., two were homozygous (m1/m1) for the defect in exon 5 and two were heterozygous (m1/m2) for the two defects in exons 5 and 4. The subjects in group 1 (wt/wt, wt/m1 and wt/m2) were the extensive metabolizers (EMs) for 5-hydroxylation of lansoprazole and were in the range of hydroxylation indexes from 3.83 to 19.8, whereas the subjects in group 2 (m1/m1 and m1/m2) were the poor metabolizers (PMs) and the indexes were in the range of 38.5 to 47.6. In group 2, AUC, t1/2 and CL/f of lansoprazole were significantly greater, longer, and lower, respectively, than those in group 1. Conclusion: The hydroxylation of lansoprazole to 5-hydroxylansoprazole was apparently impaired in the subjects with the genetic defects of CYP2C19 (m1/m1 or m1/m2).
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    Effects of grapefruit juice ingestion – pharmacokinetics and haemodynamics of intravenously and orally administered felodipine in healthy men (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 139-145 
    Details
    ISSN: 1432-1041
    Keywords: Key words Felodipine ; Dietary interaction ; Flavonoids; pharmacodynamics ; pharmacokinetics ; grapefruit juice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: To examine the effect of grapefruit juice on the metabolism of felodipine following intravenous and oral administration. Methods: The study had a randomised, four-way, crossover design in 12 healthy males. Single doses of felodipine were given as an intravenous infusion for 1 h (1.5 mg) or as an oral extended release (ER) tablet (10 mg). Grapefruit juice (150 ml) or water was ingested 15 min prior to drug intake. Results: Intake of grapefruit juice did not significantly alter the intravenous pharmacokinetics of felodipine compared to control treatment, whereas after oral drug administration it did lead to an increase in the mean AUC and Cmax by 72% and 173%, respectively, and the mean absolute bioavailability was increased by 112%. The fraction of the oral felodipine dose reaching the portal system was increased from 45% to 80% when intake of drug was preceded by grapefruit juice ingestion. The pharmacokinetics of the primary metabolite, dehydrofelodipine, was affected by the intake of juice, resulting in a 46% increase in Cmax. Juice intake immediately before oral felodipine resulted in more pronounced haemodynamic effects of the drug as measured by diastolic blood pressure and heart rate. However, the haemodynamic effects of the intravenous administration were not altered by juice intake. Vascular-related adverse events were reported more frequently when oral drug administration was preceded by juice intake compared with control treatment. Taking grapefruit juice immediately prior to intravenous felodipine administration did not cause any alteration in the adverse event pattern. Conclusion: The main acute effect of the grapefruit juice on the plasma concentrations of felodipine is mediated by inhibition of gut wall metabolism.
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    Pharmacokinetics and bioavailability of oral and intramuscular artemether (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 307-310 
    Details
    ISSN: 1432-1041
    Keywords: Key words Artemether ; Thai males; malaria ; dihydroartemisinin ; pharmacokinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The pharmacokinetics and bioavailability of artemether and dihydroartemisinin were investigated in eight Thai males following the administration of single oral and intramuscular doses of artemether (300 mg) in a randomized two-way cross-over study. Results: Both oral and intramuscular artemether were well-tolerated. In most cases, artemether and dihydroartemisinin were detected in plasma after 30 min and declined to levels below the limit of detection within 18–24 h. Compared with intramuscular administration, oral administration of artemether resulted in a relatively rapid but incomplete absorption [Cmax: 474 vs 540 ng · ml−1; t max: 2.0 vs 3.9 h; AUC: 2.17 vs 5.20 μg · h · ml−1]. Geographic means of lag-time and absorption half-life (t 1/2a) of oral vs intramuscular artemether were 0.28 and 1.1 h vs 0.30 and 2 h, respectively. t 1/2z was significantly shortened after the oral dose [2.8 vs 6.9 h]. Mean oral bioavailability relative to intramuscular administration was 43.2%. The ratio of the AUCs of artemether to dihydroartemisinin was significantly lower after the oral than after the intramuscular dose (geometric mean: 0.29 vs 0.60).
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    Itraconazole moderately increases serum concentrations of oxybutynin but does not affect those of the active metabolite (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 403-406 
    Details
    ISSN: 1432-1041
    Keywords: Key words Oxybutynin ; Itraconazole; N-desethyloxy‐butynin; drug interaction ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Oxybutynin has low oral bioavailability due to an extensive presystemic metabolism. It has been suggested that the biotransformation of oxybutynin is dependent on CYP3A. Because itraconazole, a widely used mycotic, is a potent inhibitor of CYP3A4, we wanted to study a possible interaction between oxybutynin and itraconazole. Methods: In this double-blind, randomized, two-phase cross-over study, ten healthy volunteers received either 200 mg itraconazole or placebo for 4 days. On day 4, each volunteer ingested a single dose of 5 mg oxybutynin. Serum concentrations of oxybutynin, its active metabolite N-desethyloxybutynin, and itraconazole were monitored over 24 h. Results: Itraconazole significantly increased both the area under the serum drug concentration-time curve (AUC0–t) and the peak concentration of oxybutynin twofold. The AUC0–t and the peak concentration of N-desethyloxybutynin were not significantly affected by itraconazole. Itraconazole did not change the peak time or the elimination half-life of either oxybutynin or N-desethyloxybutynin. The occurrence of adverse events after oxybutynin administration was not increased by itraconazole. Conclusions: Itraconazole moderately increases serum concentrations of oxybutynin, probably by inhibiting the CYP3A-mediated metabolism. However, the concentrations of N-desethyloxybutynin were practically unchanged. Since about 90% of the antimuscarinic activity of oxybutynin is attributable to N-desethyloxybutynin, any interaction of oxybutynin with CYP3A4 inhibiting drugs has only minor clinical significance.
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    URL: http://dx.doi.org/10.1007/s002280050309
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    Population analysis of the non-linear red blood cell partitioning of draflazine following various infusion durations (1997)
    Springer
    European journal of clinical pharmacology 53 (1997), S. 57-63 
    Details
    ISSN: 1432-1041
    Keywords: Key wordsDraflazine ; Population analysis; nucleoside transport inhibitor ; non-linear red blood cell partition ing ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The pharmacokinetics and non-linear red blood cell partitioning of the nucleoside transport inhibitor draflazine were investigated in 19 healthy male and female subjects (age range 22–55 years) after a 15-min i.v. infusion of 1 mg, immediately followed by infusions of variable rates (0.25, 0.5 and 1 mg · h−1) and variable duration (2–24 h). Methods: The parameters describing the capacity-limited specific binding of draflazine to the nucleoside transporters located on erythrocytes were determined by NONMEM analysis. The red blood cell nucleoside transporter occupancy of draflazine (RBC occupancy) was evaluated as a pharmacodynamic endpoint. Results: The population typical value for the dissociation constant K d (%CV) was 0.648 (12) ng · ml−1 plasma, expressing the very high affinity of draflazine for the erythrocytes. The typical value of the specific maximal binding capacity Bmax (%CV) was 155 (2) ng · ml−1 RBC. The interindividual variability (%CV) was moderate for K d (38.9%) and low for Bmax (7.8%). As a consequence, the variability in RBC occupancy of draflazine was relatively low, allowing the justification of only one infusion scheme for all subjects. The specific binding of draflazine to the red blood cells was a source of non-linearity in draflazine pharmacokinetics. Steady-state plasma concentrations of draflazine virtually increased dose-proportionally and steady state was reached at about 18 h after the start of the continuous infusion. The t1/2βaveraged 11.0–30.5 h and the mean CL from the plasma was 327 to 465 ml · min−1. The disposition of draflazine in whole blood was different from that in plasma. The mean t1/2β was 30.2 to 42.2 h and the blood CL averaged 17.4–35.6 ml · min−1. Conclusion: Although the pharmacokinetics of draflazine were non-linear, the data of the present study demonstrate that draflazine might be administered as a continuous infusion over a longer time period (e.g., 24 h). During a 15-min i.v. infusion of 1 mg, followed by an infusion of 1 mg · h−1, the RBC occupancy of draflazine was 96% or more. As the favored RBC occupancy should be almost complete, this dose regimen could be justified in patients.
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    URL: http://dx.doi.org/10.1007/s002280050337
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    Single-dose pharmacokinetics of paracetamol and its conjugates in Chinese non-insulin-dependent diabetic patients with renal impairment (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 285-288 
    Details
    ISSN: 1432-1041
    Keywords: Key words Paracetamol ; Renal failure; polar conjugates ; non-insulin-dependent diabetes mellitus (NIDDM) ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: A single oral dose of paracetamol (20 mg · kg−1) was given to 38 Chinese patients with non-insulin-dependent diabetes mellitus (NIDDM) who had either normal renal function or varying degrees of renal impairment, with creatinine clearances ranging from 4 to 123 ml · min−1 · 1.73 m−2. The plasma and urinary concentrations of paracetamol and its major metabolites were measured by high-performance liquid chromatography (HPLC). Results: The absorption and elimination of paracetamol were unaffected by renal impairment. However, the area under the plasma concentration time curve and the elimination half-life of paracetamol metabolites increased significantly with worsening renal insufficiency. Mean renal clearances of paracetamol and its conjugates were significantly reduced in these subjects. There was no evidence of altered metabolic activation with renal impairment. Conclusion: The results demonstrate that paracetamol disposition is minimally affected by diabetic nephropathy; however, extensive accumulation of conjugates may occur.
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    URL: http://dx.doi.org/10.1007/s002280050291
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    Pharmacokinetics and pharmacodynamics of ranitidine in renal impairment (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 229-234 
    Details
    ISSN: 1432-1041
    Keywords: Key words Ranitidine ; Renal impairment; dose adjustment ; pharmacodynamics ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The pharmacodynamics and pharmacokinetics of ranitidine were examined in subjects with varying degrees of renal function to determine the effect of this condition on acid-antisecretory activity. Methods: Subjects with creatinine clearances (CCr) ranging from 0 to 213 ml · min−1 received single 50-mg and 25-mg i.v. doses of ranitidine. This was followed by determination of serum and urine ranitidine concentrations, and continuous gastric pH monitoring for 24 h. Results: Serum ranitidine concentrations were described by a two-compartment model linked to a sigmoidal Emax model describing gastric pH. Ranitidine renal clearance, ranging from 0 to 1003 ml · min−1, correlated with CPAH (r 2 = 0.707), while non-renal clearance was unaltered. Steady-state volume of distribution decreased by half in severe renal impairment. No changes in the effective concentration at half-maximal response (EC50), maximal response (Emax), or basal response (E0) were observed. Thus, renal elimination of ranitidine declined in parallel with renal function, while sensitivity to the pharmacologic effect (gastric pH elevation) was unaltered. Ranitidine was well tolerated in these renally impaired subjects. Conclusion: These data indicate that the current recommendation for renal impairment dose reduction (by two-thirds when CCr〈50 ml · min−1) might result in under-treating moderately impaired patients, and suggests a less conservative dose reduction (by half when CCr〈10 ml · min−1) to avoid therapeutic failure while remaining within the wide margin of safety for this drug.
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    URL: http://dx.doi.org/10.1007/s002280050279
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    Pharmacokinetic interaction study of citalopram and cimetidine in healthy subjects (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 241-242 
    Details
    ISSN: 1432-1041
    Keywords: Key words Citalopram ; Cimetidine; drug ; drug interac‐tion ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002280050282
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    Pharmacokinetic-pharmacodynamic modelling as a tool to evaluate the clinical relevance of a drug-food interaction for a nisoldipine controlled-release dosage form (1997)
    Springer
    European journal of clinical pharmacology 51 (1997), S. 473-480 
    Details
    ISSN: 1432-1041
    Keywords: Key words Nisoldipine ; Hypertension; Ca antagonist ; pharmacokinetics ; pharmacodynamics ; PK/PD modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Nisoldipine, a calcium antagonist of the dihydropyridine class, has been used in the treatment of hypertension and angina pectoris. A new controlled-release dosage form (nisoldipine coat-core, NCC) has been developed to allow once daily dosing. In addition to a formal food interaction study as requested by regulatory authorities for controlled-release dosage forms, a subsequent study was conducted to determine the clinical relevance of the changes in nisoldipine plasma concentration vs time profiles seen in the food effect study. Methods: After a placebo run-in phase of 6 days, 12 hypertensive patients started treatment with 20 mg NCC once daily (days 0–3, 5–6, 8–9). On days 4, 7 and 10 the NCC was substituted for 5, 10 and 20 mg nisoldipine solution, respectively, in order to obtain nisoldipine plasma concentration vs time profiles comparable to the ones resulting from the concomitant intake of food and NCC. Simultaneous measurements of blood pressure (BP) and nisoldipine concentration were performed on days 3, 4, 7 and 10. Results: The relationship between nisoldipine plasma concentrations and percentage reduction in BP [diastolic (DBP) and systolic (SBP), supine and standing] could be described by an Emax model. The mean maximum reduction (Emax) relative to baseline was about 36.4% and 37.7% (DBP, supine and standing) and 27.9% and 29.2% (SBP, supine and standing), respectively. The interindividual variability (% CV) in Emax was low, ranging from 17.6% to 28.8%. The mean nisoldipine plasma concentration corresponding to 50% of the maximum effect (EC50) ranged between 0.99 and 2.62 μg · l–1 with a pronounced interindividual variability (% CV) of 89.5–108.8%. Mean Cmax values after administration of the 30 and 40 mg NCC together with food were 4.5 and 7.5 μg · l–1, respectively. Based on the concentration-effect relationship established in the present study, the effect achieved with a concentration of 7.5 μg · l–1 will be about 77% of Emax for DBP and about 88% of Emax for SBP, respectively. Conclusion: At the time of maximum plasma concentration the additional decrease in BP relative to baseline due to the food effect will be about 7–15% for DBP and 3–9% for SBP. After administration of the 10␣mg solution with a mean Cmax of 8.7 μg · l–1, only headache and flush with mild severity have been reported as adverse events. These maximum concentrations are comparable to Cmax values seen after intake of 40 mg NCC with food. With regard to heart rate (HR) there were distinct differences between the two formulations: Following administration of 5, 10 and 20 mg nisoldipine solution, there were dose-dependent increases in HR by a maximum of 4, 12 and 16 beats · min−1, respectively, whereas the HR profile for the NCC was similar to that seen under placebo treatment.
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    URL: http://dx.doi.org/10.1007/s002280050233
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    Cost-Effective Nutrient Reductions to the Baltic Sea (1997)
    Springer
    Environmental and resource economics 10 (1997), S. 341-362 
    Details
    ISSN: 1573-1502
    Keywords: Baltic Sea ; eutrophication ; nitrogen ; phosphorus ; cost effective
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Economics
    Notes: Abstract Due to eutrophication caused by heavy loads of nitrogen and phosphorus, the biological conditions of the Baltic Sea have been disturbed: large sea bottom areas without any biological life, low stocks of cods, and toxic blue green algaes. It is recognized that the nitrogen and phosphorus loads to the Baltic Sea must be reduced by 50% in order to restore the sea. The main purpose of this paper is to calculate cost effective nitrogen and phosphorus reductions to the Baltic Sea from the nine countries surrounding the Baltic Sea. The results show a significant difference in minimum costs of decreasing nitrogen and phosphorus loads to the Sea: approximately 12 000 millions of SEK per year and 3 000 millions of SEK respectively for reductions by 50%. It is also shown that a change from a policy of cost-effective nutrient reductions to a policy where each country reduces the nutrient loads by 50% increase total costs for both nitrogen and phosphorus reductions by about 300%. The results are, however, sensitive to several of the underlying assumptions and should therefore be interpreted with much caution.
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    URL: http://dx.doi.org/10.1023/A:1026497515871
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    Characteristics of Hydroxamic Acid Induction in Wheat Triggered by Aphid Infestation (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 2695-2705 
    Details
    ISSN: 1573-1561
    Keywords: Defense ; herbivory ; aphids ; wheat ; Gramineae ; hydroxamic acids ; Defense theory ; Carbon/Nutrient theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Hydroxamic acids (Hx) are natural products of Gramineae that are associated with cereal resistance to pests. We aimed at characterizing the induction of Hx accumulation in seedlings of wheat,Triticum aestivum, by short-term infestation of the cereal aphid,Rhopalosiphum padi. A load of 25 aphids increased significantly the Hx levels in the infested primary leaf in comparison with control levels. Lower loads did not increase Hx concentration. Aphid infestation lasting 16 hr did not elicit induction of Hx, even after a time-lag of 32 hr to allow the expression of any induced response. Forty-eight hours was the minimum duration of aphid infestation required to trigger Hx induction. The age of the infested tissue (the primary leaf) did not affect induction. Similar increases of Hx were found in unfolding, expanding, and totally expanded primary leaves. It was determined that the regime of nutrient supply (N-intensive nutritive solutions at low and high concentration) to wheat seedlings had no effect on the magnitude of the aphid-induced Hx (N-based secondary metabolites). Results obtained are discussed in the framework of general theories of plant defense allocation.
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    Factors Regulating the Flux of Phosphate at the Sediment - Water Interface of a Subtropical Calcareous Lake: a Simulation Study with Intact Sediment Cores (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 401-409 
    Details
    ISSN: 1573-2932
    Keywords: phosphorus ; P flux ; microbial activity ; redox ; simulation ; Lake Kinneret ; sediment ; accumulative P release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Different factors which interactively control the flux of soluble reactive phosphorus (SRP) at the sediment-water interface (SWI) of Lake Kinneret were studied seasonally. The influence of pH, Eh and microbial activity on SRP flux at the SWI was investigated by manipulating the conditions in the overlying water of intact sediment cores. The calculated diffusive SRP flux out of the sediment was lower in cores sampled during winter and spring than during the period of amixis. Potential SRP release, as measured in the absence of microbial activity, was strongly enhanced upon the transition from oxic to anoxic conditions indicating P release from iron(III)-bound phosphorus. In spring and summer cores, an enhanced SRP flux from sediments at pH 7 in comparison to pH 8 indicated P release from carbonate-bound P which sedimented previously as result of high pH values during the algal spring bloom. Microbial uptake at the SWI was the most important sink for SRP and no net-flux occured under oxic conditions. The higher net-flux of P under anoxic conditions was linked to carbon limitation of the bacteria at the SWI.
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    URL: http://dx.doi.org/10.1023/A:1018335305539
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    Bottom sediments in a humic lake with artificially increased calcium content: sink or source for phosphorus? (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 457-464 
    Details
    ISSN: 1573-2932
    Keywords: sediment ; phosphorus ; fractionation ; release ; humic lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Lake Flosek (north-eastern part of Poland) is a small shallow and without outflow lake which has been limed in 1970. The concentration of Ca was increased from 3-4 mg L-1 to 17 mg L-1 in the water and from 0.2-0.3% dry weight to 0.9-1.7% dry weight in sediments (5 cm upper layer) due to CaCO3 addition to the lake. In the spring-summer seasons of 1992 and 1993, an experimental study was conducted in Lake Flosek to assess the capacity of bottom sediments to uptake and release mineral phosphorus. The rate of phosphorus exchange between sediments and near-bottom water was experimentally measured under conditions of high (100%), and of reduced (10%) oxygen saturation in near-bottom water. To determine the component of sediments responsible for the uptake of most phosphorus, the proportions of phosphorus forms in sediments were analysed. Sediments of Lake Flosek showed a slight tendency to release phosphates. The rate of this process was similar under high (100%) and low (10%) oxygen saturations ranging from - 0.161 to + 0.200 mg P m-2 d-1. This is much lower (by 1-2 orders of magnitude) than reported from other harmonic, non-humic lakes. In the total phosphorus pool, the highest content of phosphorus was found in the organic and residual phosphorus fractions (over 70% of the total phosphorus in sediments). The largest part of the readily extractable phosphorus was found in the fraction bound to Al and humic substances (41%). Both these fractions determine a weak exchange of phosphorus between sediments and water. No difference in P-release related to P-fraction compound was found in the cores taken from three sites in the lake.
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    Sediment Accumulation of Nutrients (N, P) in the Eastern Gulf of Finland (Baltic Sea) (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 477-486 
    Details
    ISSN: 1573-2932
    Keywords: sediment ; nitrogen ; phosphorus ; organic matter ; cluster analysis ; Gulf of Finland ; estuaries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Dry weight (DW), ignition loss (IL) and concentrations of total nitrogen (TN) and total phosphorus (TP) of the sediment surface layer (0 to 10 cm, 1 cm slices) were analyzed from 20 sites in the eastern Gulf of Finland. The distance of the sampling sites from the mouth of the River Neva explained the nutrient concentrations of the sediments well, while the effect of water depth was negligible. The increase of TN and the decrease of TP along the transect from the river mouth towards the open Gulf were caused by the diminishing share of allochthonous material supplied from the River Neva. The mean TN concentration of the different accumulation areas was about 40 % higher in the sediment surface than in the deeper layer (9 to 10 cm). The corresponding difference for TP varied from 53 to 56 %. The results suggest considerable netflux of nutrients from sediment to water. The net sediment accumulation of nutrients were estimated as 6.0 g m-2 a-1 of N and 1.7 g m-2 a-1 of P corresponding 22 000 t a-1 of N and 6 100 t a-1 of P for the whole eastern Gulf.
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    URL: http://dx.doi.org/10.1023/A:1018399625103
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    Benthic fluxes of dissolved inorganic carbon, nutrients and oxygen in the Gulf of Trieste (Northern Adriatic) (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 305-314 
    Details
    ISSN: 1573-2932
    Keywords: Adriatic Sea ; nutrients ; benthic fluxes ; carbon ; nitrogen ; silicon ; phosphorus ; budgets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Benthic fluxes of dissolved inorganic N, Si and P nutrients, alkalinity, dissolved inorganic C (DIC), and O2 from sediments in the Gulf of Trieste (northern Adriatic, Italy) were measured monthly in the period September 1995 – August 1996 using in situ incubated light benthic chambers. The highest efluxes of DIC, NH4 +, PO4 3−, Si(OH)4, and NO3 − influxes encountered in late summer — early autumn were the consequence of degradation of benthic microalgae, and in autumn mostly of sedimented phytoplankton. High NO3 − efflux was observed in spring. Only NH4 + and Si(OH)4 fluxes were significantly correlated with temperature. This correlation suggests that the rate of downward input and the quality and quantity of sedimentary organic matter (autochthonous and allochthonous) were superimposed on the temperature fluctuations. High DIC, NH4 + and Si(OH)4 effluxes observed in July 1996 were due to the late spring — early summer degradation of sedimentary organic matter produced by benthic microalgae, while the autumn phytoplankton bloom was quickly reflected in enhanced benthic fluxes due to higher temperature. Significant correlations between NH4 +, PO4 3− and Si(OH)4 fluxes suggested their parallel regeneration and utilization at the sediment-water interface. The nutrient fluxes were linked to O2 consumption, suggesting that aerobic oxidation processes were important at the sediment-water interface in the Gulf. The N, P and Si nutrients released from sediment pore waters are probably utilized in benthic microalgal and bottom-water primary production. This indicates that pelagic and benthic communities in the central part of the Gulf of Trieste function relatively independently of each other.
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    URL: http://dx.doi.org/10.1007/BF02406870
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    Trophic modifications in Lake Como (N. Italy) caused by the zebra mussel (Dreissena polymorpha) (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 633-640 
    Details
    ISSN: 1573-2932
    Keywords: zebra mussel ; Dreissena polyrnorpha ; phosphorus ; trophic state ; recovery ; take Como
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A large scale study on the western basin of Lake Como (N. Italy) was started in 1995 to examine the effects of the zebra mussel colonization which began in early '90. Our results have been related to '91–92 data (pre-Dreissena period), before the maximum colonization of zebra mussel. In spring and summer of the post-Dreissena period total phosphorus, P-PO4, nitrate and chlorophyll values decreased, while ammonium and tranparency increased at every sampling station. Zebra mussel does not modify the trophic state of this sub-basin but it plays an important role in nutrient cycling. The entire population can filter epilimnetic craters 2.1 times per year and can produce 2.9 × 104 t y of pseudofaeces which are transferred to sediments.
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    Influence of Taxonomy, Ecology, and Seasonality in River Stage on Fish Contamination Risks in Floodplain Swamps of the Lower Mississippi River (1998)
    Springer
    Ecotoxicology 7 (1998), S. 325-334 
    Details
    ISSN: 1573-3017
    Keywords: contamination risks ; fish ; Mississippi River ; ecological factors ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract We compared contamination levels in fish from contaminated and uncontaminated floodplain swamps of the lower Mississippi River to assess differences in contamination risks between swamps, across different taxonomic and ecological groupings of fishes within and between swamps, and with seasonality in river stage. Fish tissue levels of inorganic contaminants were substantially lower than environmental levels in both swamps, suggesting either that fish were not uptaking these contaminants, or they were effectively eliminating the contaminants from their bodies. Tissue levels of organic contaminants were high relative to environmental levels, suggesting that these contaminants were bioaccumulating. Organic contaminants were significantly higher in fish from the contaminated swamp (Devil's Swamp) than in fish from a reference swamp up river (Tunica Swamp). Because the organic contaminants were largely confined to sediments, we expected bottom-oriented fishes to have higher concentrations than pelagic fishes. Assuming that uptake was primarily through the food chain, we expected top predators to exhibit higher concentrations than low-level consumers. We also expected year- round swamp residents to exhibit higher accumulations than more transitory users of backswamp habitat. However, organic contaminant levels did not differ in the directions expected for any of these groupings. We did observe differences in organic contaminant levels within and between swamps for different taxonomic groupings of fishes (species and genera). Some taxa occupying low to middle positions in the food web (e.g., gizzard shad, Lepomis spp.) exhibited higher concentrations than taxa near the top of the food web. Within Devil's Swamp, organic contaminant levels were significantly higher at low river stage, when fish were confined to the swamp, than at high river stage, when fish were free to move between the river and the swamp. We caught more species and more fish per unit effort in Devil's Swamp than in Tunica Swamp, contrary to expectations if contaminants in the former were negatively impacting population and community structure. Species richness differences between swamps were a consequence of catch differences, with higher catch corresponding to inclusion of more rare species. The lower catch in Tunica Swamp may have resulted from physical modifications of its waterways to support agriculture and hunting. The results of this study underscore the importance in factoring information on the taxonomy and ecology of organisms, and seasonal changes in environmental conditions, into assessments of contamination risks.
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    Expression of a wheat ADP-glucose pyrophosphorylase gene during development of normal and water-stress-affected anthers (1997)
    Springer
    Plant molecular biology 34 (1997), S. 445-453 
    Details
    ISSN: 1573-5028
    Keywords: ADP-glucose pyrophosphorylase ; anther ; pollen ; male sterility ; water stress ; wheat ; starch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In wheat (Triticum aestivum L.), water deficit during meiosis in the microspore mother cells (MMCs) induces pollen abortion, resulting in the failure of fertilization and a reduction in grain set. In stressed plants, meiosis in MMCs proceeds normally but subsequent pollen development is arrested. Unlike normal pollen grains, which accumulate starch during the late maturation phase, stress-affected anthers contain pollen grains with little or no starch. Stress also alters the normal distribution of starch in the anther wall and connective tissue. To determine how starch biosynthesis is regulated within the developing anthers of stressed plants, we studied the expression of ADP-glucose pyrophosphorylase (AGP), which catalyzes the rate limiting step of starch biosynthesis. Two partial-length cDNAs corresponding to the large subunit of AGP were amplified by RT-PCR from anther RNA, and used as probes to monitor AGP expression in developing anthers of normal and water-stressed plants. These clones, WAL1 and WAL2, had identical deduced amino acid sequences and shared 96% sequence identity at the nucleic acid level. In normal anthers, AGP expression was biphasic, indicating that AGP expression is required for starch biosynthesis both during meiosis and later during pollen maturation. AGP expression in stressed anthers was not affected during the first phase of starch accumulation, but was strongly inhibited during the second phase. We conclude from these results that the reduced starch deposition later in the development of stressed pollen could be the result of a lower expression of AGP. However, this inhibition of AGP expression is unlikely to be the primary cause of male sterility because anatomical symptoms of pollen abortion are observed prior to the time when AGP expression is inhibited.
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    URL: http://dx.doi.org/10.1023/A:1005882118506
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    Characterization of dynamics of the psbD light-induced transcription in mature wheat chloroplasts (1997)
    Springer
    Plant molecular biology 33 (1997), S. 267-278 
    Details
    ISSN: 1573-5028
    Keywords: chloroplast ; in vitro transcription ; light ; psbA ; psbD/C operon ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Dynamical aspects of three chloroplast promoters responding to change in light condition were examined in mature chloroplasts of wheat (Triticum aestivum) by in vitro transcription. The wheat psbD/C operon has four distinct promoters, two of which named as D/C-3 and D/C-4 promoters dominantly function in mature chloroplasts to produce the mRNAs encoding D2/CP43 and CP43 alone, respectively. Activity of the D/C-3 promoter in mature chloroplasts was reduced to less than 30% by 24 h dark adaptation and recovered by re-illumination to the original level within 30 to 60 min. The activation of the D/C-3 promoter which requires de novo cytoplasmic protein synthesis was induced by low fluence of light (e.g. 16 µE m-2 s-1), but the extent of activation increased with increasing light fluence. The accumulation of mRNAs from the D/C-3 promoter saturated at 2- to 3-fold higher level within 2 h when the dark-adapted seedlings were transferred to the lig at 72 µE m-2 s-1, concomitant with the increase in rate of D2 synthesis, suggesting that synthesis of D2 in mature chloroplasts is controlled via the D/C-3 promoter activity in a light-dependent way. Activity of the D/C-4 promoter slightly increased in the dark and decreased in the light. Effect of light on the psbA promoter activity was not observed at all in mature chloroplasts. In vitro transcriptional analysis of the D/C-3 promoter with 5′ deletion mutations revealed that at least two cis elements which are located within the sequences of -78 to -47 and -46 to -29 of the transcription initiation site, respectively, act as enhancing elements in the D/C-3 promoter. The light-switching element of the transcription, however, was suggested to be located in the core promoter sequence downstream of the -35 element.
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    URL: http://dx.doi.org/10.1023/A:1005799001271
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    The wheat protein kinase gene, TaPK3/, of the PKABA1 subfamily is differentially regulated in greening wheat seedlings (1997)
    Springer
    Plant molecular biology 33 (1997), S. 935-941 
    Details
    ISSN: 1573-5028
    Keywords: cold temperature ; dehydration ; greening ; protein kinase ; Triticum aestivum/ ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have identified a new wheat PKABA1/-like protein kinase gene, TaPK3/, that is expressed in greening wheat seedlings. TaPK3 has high sequence homology (97% similarity with some sequence diversity at the 3' end) to the wheat PKABA1 protein kinase mRNA, which is upregulated by cold-temperature treatment, dehydration and abscisic acid (ABA). Use of a TaPK3 gene-specific probe has revealed that TaPK3 is differentially expressed with respect to PKABA1. TaPK3 mRNA accumulates in greening shoot tissue of wheat, but is not affected by dehydration, cold-temperature treatment or ABA. Based on sequence and expression differences, we conclude that expression of the PKABA1/-like protein kinases is not limited to stress responses.
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    cDNA structure and expression patterns of a low-temperature-specific wheat gene tacr7 (1997)
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    Plant molecular biology 34 (1997), S. 643-650 
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    ISSN: 1573-5028
    Keywords: callus ; crown tissue ; gene expression ; low temperature ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The low-temperature (2 °C)-specific wheat cDNA, pTACR7, represents a gene designated tacr7 from hard red winter wheat (HRWW; Triticum aestivum L. cv. Winoka). The term low-temperature-specific (LTS) is used because tacr7 is not induced by ABA or stresses such as salt, dehydration, and heat. pTACR7 was isolated by RT-PCR with mRNA from wheat crown tissue, the oligonucleotide primers derived from the barley cognate pHVCR8 (GenBank accession number L28091). Based on the deduced amino acid sequence, TACR7 is highly hydrophobic, with a single transmembrane domain and an amino acid bias for leucine (19%). Thus, the encoded protein TACR7 is unique among low-temperature-regulated wheat proteins described in the literature. Analysis of steady-state levels of tacr7 transcripts (630 nt) showed accumulation in wheat seedlings, crown tissue, and callus cultures after transfer from control (25 °C) to low temperature (2 °C). No detectable transcripts were observed by northern blot hybridization with pTACR7 probe from seedling or callus treated with ABA, salt, dehydration, or heat stress. tacr7 transcripts accumulated during 2 °C exposure to a greater amount in a freeze-resistant HRWW (FR; SDmut 16029) than in a freeze-susceptible HRWW (FS; SDmut 16169) crown tissue, with the largest difference between genotypes being 30% ± 3% at 3 weeks.
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    Lanceispora amphibia gen. et sp. nov., a new amphisphaeriaceous ascomycete inhabiting senescent and fallen leaves of mangrove (1997)
    Springer
    Mycoscience 38 (1997), S. 207-213 
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    ISSN: 1618-2545
    Keywords: Bruguiera gymnorrhiza ; ecology ; Lanceispora amphibia ; mangrove ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lanceispora amphibia gen. et sp. nov. in the Amphisphaeriaceae is described from senescent and fallen leaves ofBruguiera gymnorrhiza in mangrove forests in the Southwest Islands, Japan. The fungus produces immersed ascomata in leaf tissue, cylindrical asci with an apical ring staining blue with iodine, and oblanceolate ascospores with a septum above the middle. Studies on the fungal succession on the mangrove leaves revealed thatL. amphibia infects senescent leaves on the tree and inhabits intertidal fallen leaves, showing the highest frequency of occurrence at the late stage of decomposition. In culture the optimal conditions for hyphal growth were 20 ppt salinity and 30°C, and those for sexual reproduction were 10 ppt salinity and 25°C. Growth at 0 ppt (fresh water) was depressed. The fungus has amphibious habits, growing on the tree and in intertidal water; and it is adapted to the high osmotic conditions in leaf tissues of the mangrove tree and to the subtropical, brackish water environment of mangrove forests.
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    Taxonomical studies on ovariicolous ustomycetes on caryophyllaceae I.Ustilago jehudana andUstilago moenchiae-manticae (1997)
    Springer
    Mycoscience 38 (1997), S. 323-328 
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    ISSN: 1618-2545
    Keywords: Bauhinus ; Microbotryum ; taxonomy ; Ustilago ; ustomycetes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A study of the type specimen ofUstilago jehudana resulted in the correction of the diagnosis. The sori are localized in the host gynoecium but not in the anthers. Morphological characters of the sori and ustospores of the later describedU. moenchiae-manticae are identical with these ofU. jehudana. Ustilago moenchiae-manticae is reduced here to a synonym ofU. jehudana. The smut is reported as new to Bulgaria on a new host, viz.,Moenchia erecta. A new combination,Bauhinus jehudanus, is proposed.
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    Morphology and molecular phylogeny ofTretopileus sphaerophorus, a synnematous hyphomycete with basidiomycetous affinities (1998)
    Springer
    Mycoscience 39 (1998), S. 21-30 
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    ISSN: 1618-2545
    Keywords: Aphyllophorales ; ribosomalDNA ; synnematous hyphomycete ; taxonomy ; Tretopileus sphaerophorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tretopileus sphaerophorus, a synnematous hyphomycete with basidiomycetous affinities was newly isolated from the decaying petiole and peduncle ofCocos nucifera collected in Depok, Indonesia. The species produced first a bulbil as a propagule on the top of a synnema. After the bulbil had fallen, the synnema proliferated about seven times to produce new bulbils, each time making conspicuous nodes at the upper part. By careful morphological observation, clamp connections were confirmed on the hyphae in the specimens and culture. In culture, each hyphal cell with or without a clamp was found to be dikaryotic by DAPI nuclear staining. Germination of the bulbils occurred first from projecting hyphal tips on their upper surface, which have been treated as germ pores. The inner structure of the bulbils, the hyaline mucus of the bulbils, and conidium-like hyphal fragments were also examined. Phylogenetically,T. sphaerophorus was inferred to be related to the Aphyllophorales based on the nuclear encoded small subunit (18S) rDNA using the homology search system (FASTA) and the neighbour-joining method.
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    The order phyllachorales: Taxonomic review (1998)
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    Mycoscience 39 (1998), S. 97-104 
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    ISSN: 1618-2545
    Keywords: Loculoascomycetes ; phyllachoraceae ; phyllachorales ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The order Phyllachorales contains ascomycetous fungi of considerable economic importance. The group is represented mostly by foliar parasites which produce perithecia under a clypeus, inside a stroma, or do not produce any stromatic tissue. A major taxonomic problem with this order is the lack of reliable morphological characters that clearly delimit the entire group. The main purpose of this review is to provide a clear picture of the taxonomic relationships of the order Phyllachorales, along with a key to the most important genera in the family Phyllachoraceae.
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    A synopsis of the genusScleromitrula (=Verpatinia) (Ascomycotina: Helotiales: Sclerotiniaceae) (1997)
    Springer
    Mycoscience 38 (1997), S. 55-69 
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    ISSN: 1618-2545
    Keywords: discomycetes ; ITS rDNA phylogeny ; morphology ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The systematics ofScleromitrula andVerpatinia of the family Sclerotiniaceae is reevaluated on the basis of morphological, cultural and molecular criteria.Scleromitrula shiraiana, Verpatinia species andCiborinia candolleana share gross morphological, microanatomical and cultural features which clearly distinguish them from the closely relatedCiborinia andRutstroemia species. Phylogenetic analyses of sequences from the internal transcribed spacer region (ITS1, ITS2, and the 5.8S gene) of nuclear ribosomal DNA demonstrate that the stipitate-capitate specimens ofScleromitrula andVerpatinia species plus the stipitate-cupulateCiborinia candolleana constitute a monophyletic clade separate from a clade including the type species ofCiborinia. Scleromitrula is emended to includeS. shiraiana, the new speciesS. rubicola, C. candolleana, and specimens formerly assigned toVerpatinia. A key to the accepted species ofScleromitrula is provided.
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    Ypsilonidium bananisporum sp. nov. (Ceratobasidiales) from Iriomote Island, Japan (1997)
    Springer
    Mycoscience 38 (1997), S. 71-73 
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    ISSN: 1618-2545
    Keywords: Ceratobasidiaceae ; Japan ; taxonomy ; Ypsilonidium bananisporum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ypsilonidium bananisporum sp. nov. belonging to Ceratobasidiales is described and illustrated. This fungus has all the characteristics of the genusYpsilonidium including reticulate-hypochnoid basidiomes, broad hyphae branching at right angles, broadly clavate basidia with two sterigmata, and basidiospores germinating by repetition. It differs from all hitherto known species in the genus by producing suballantoid to banana-shaped basidiospores, measuring 19.5–22×5.5–6 μm.
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    Myxomycetes from Israel IV (1997)
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    Mycoscience 38 (1997), S. 87-89 
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    ISSN: 1618-2545
    Keywords: Israel ; Mycomycetes ; Physarales ; Stemonitales ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ten taxa of myxomycetes growing mainly withEucalyptus, oak and pine are described. They were found in Upper Galilee, Mt. Carmel and Central parts of the country and all are new to Israel.
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    Mycoleptodiscus terrestris from black pepper roots in the Dominican Republic (1997)
    Springer
    Mycoscience 38 (1997), S. 91-94 
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    ISSN: 1618-2545
    Keywords: hyphomycetes ; identification ; taxonomy ; Tuberculariaceae ; Tuberculariales
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mycoleptodiscus terrestris from black pepper roots in the Dominican Republic is described together with some notes and photomicrographs.
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    Microsphaeropsis rugospora, a new species from Japanese soil (1997)
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    Mycoscience 38 (1997), S. 429-431 
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    ISSN: 1618-2545
    Keywords: coelomycete ; Japan ; Microsphaeropsis rugospora ; soil fungus ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Abstract In an exploratory survey of soil-borne mitosporic fungi as producers of secondary metabolites useful to the pharmaceutical industry, a pale yellow pycnidial coelomycete was encountered and isolated on potato-dextrose agar. The fungus was characterized as follows: rapid growth on common media, conidiomata which are non-pulvinate, semi-immersed to immersed, nearly globose, glabrous, with a slightly papillate ostiole; pale yellowish brown, translucent, membranaceous peridium; discrete, ampulliform, monophialidic conidiogenous cells; and onecelled, dark brown, globose, thick-walled, rugose conidia which germinate very easily. In accordance with this profile, our isolate is included in the genusMicrosphaeropsis Höhnel. (Morgan-Jones, 1974a, b; Sutton, 1977, 1980; Morgan-Jones and White, 1987; Heiny et al., 1992; Katumoto, 1992). However, it proved to be sufficiently different from all described species ofMicrosphaeropsis to warrant its description as a new species.
    Notes: Abstract A new species ofMicrosphaeropsis (Sphaeropsidales, Coelomycetes),M. rugospora, is described and illustrated. This fungus is characterized by its rapid growth on common media such as oatmeal and potato-carrot agars; semi-immersed to immersed, nearly globose, papillate pycnidias; pale yellowish brown, translucent, membranaceous peridium; monophialidic, ampulliform conidiogenous cells; and one-celled, dark brown, globose conidia ornamented with distinct tubercles. The holotype was isolated from the cultivated soil in Tanegashima Island, southern Japan.
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    On some species ofMycogloea (1998)
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    Mycoscience 39 (1998), S. 31-36 
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    ISSN: 1618-2545
    Keywords: Mycogloea ; Platygloea ; Platygloeaceae ; Platygloeales ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three new species ofMycogloea are described and illustrated; they are:M. amethystina from Canada,M. nipponica, from Japan, andM. bullata from Thailand.Mycogloea tahitiensis is reported from Japan and additional undescribed taxa in the genus are briefly noted. Some characteristics of the genus are discussed, and a key is provided for six species recognized at this time.
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    Different levels of morphometric variation in three heterogamous dogrose species (Rosa sect.Caninae, Rosaceae) (1997)
    Springer
    Plant systematics and evolution 204 (1997), S. 207-224 
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    ISSN: 1615-6110
    Keywords: Rosaceae ; Rosa sect.Caninae ; Systematics ; taxonomy ; genetic variation ; hemisexual ; apomixis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Difficulties in delimiting well-defined entities in the dogroses (Rosa sect.Caninae) has resulted in very variable taxonomic treatments. The present study was undertaken to provide a background for taxonomy as well as plant breeding. Morphometric diversity was analysed on seedlings obtained from field collections in South Sweden of three species,Rosa dumalis, R. rubiginosa andR. villosa. A canonical variates analysis showed that the three species are relatively distinct whereas two subspecies ofR. dumalis were less well discriminated. Analyses of variance demonstrated that intraspecific variation is pronounced inR. dumalis and, to a lesser extent, inR. villosa.
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    Anchusella, a new genus ofBoraginaceae from the Central-Eastern Mediterranean (1997)
    Springer
    Plant systematics and evolution 205 (1997), S. 241-264 
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    ISSN: 1615-6110
    Keywords: Boraginaceae ; Boragineae ; Anchusella ; A. variegata ; A. cretica ; Lycopsis ; Anchusa ; Mediterranean flora ; macromorphology ; micromorphology ; karyology ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The two closely related speciesLycopsis variegata andAnchusa cretica, formerly placed inAnchusa subg.Rivinia, were compared with the type species ofLycopsis andAnchusa, on the basis of a set of macro and microcharacters. The presence of only two fertile stamens as well as other peculiar characters in flower structure, androecium, gynoecium, pollen and fruit, supports the institution of the new genusAnchusella, consisting ofA. variegata andA. cretica. Karyological and eco-chorological aspects are consistent with morphological data in pointing to the autonomy of this genus, which appears characterized by autapomorphic, advanced traits.
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    Comparative HPLC analysis of seed albumins fromVicia faba andV. kalakhensis (Fabaceae) (1997)
    Springer
    Plant systematics and evolution 208 (1997), S. 1-9 
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    ISSN: 1615-6110
    Keywords: Fabaceae ; Vicia faba ; V. kalakhensis ; Seed albumins ; HPLC ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previously reported electrophoretic seed albumin data have shown an unexpected association ofVicia faba withV. kalakhensis. In the present work, seed albumins ofV. faba (subsp.paucijuga and subsp.faba) were compared with those ofV. kalakhensis using ionexchange (IE) and reversed-phase (RP) high-performance liquid chromatography (HPLC). Two subspecies ofV. faba displayed similar seed albumin profiles. On the other hand, seed albumin profiles ofV. faba andV. kalakhensis showed no major protein peak in common either in IE-HPLC or RP-HPLC chromatograms. The reported differences in seed albumin composition ofV. faba andV. kalakhensis are consistent with other taxonomical data showingV. faba to be genetically distant from the wild relatives.
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    Electrophoretic seed albumin patterns inVicia species of sectt.Hypechusa andPeregrinae (Fabaceae) (1997)
    Springer
    Plant systematics and evolution 208 (1997), S. 239-248 
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    ISSN: 1615-6110
    Keywords: Fabaceae ; Vicia ; sect.Hypechusa ; sect.Peregrinae ; Electrophoresis ; seed albumins ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This work is a continuation of electrophoretic investigations aimed at revealing a wild relative ofVicia faba. Electrophoretic analysis (PAGE) of seed albumins covered 52 accessions representing eightVicia species of sect.Hypechusa and two species of sect.Peregrinae. Most of the examined species showed an intraspecific variation due to differences between accessions and/or individual variation within accessions. In spite of the intraspecific variation, marked interspecific differences were recorded. However, none of the investigated species displayed electrophoretic seed albumin patterns similar to those reported earlier forV. faba. Contribution of the obtained results to characterization of the examined taxa is discussed.
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    Phylogenetic relationships betweenVicia faba (Fabaceae) and related species inferred from chloroplasttrnL sequences (1998)
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    Plant systematics and evolution 212 (1998), S. 247-259 
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    ISSN: 1615-6110
    Keywords: Fabaceae ; Vicia faba ; trnL intron ; PCR-sequencing ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The chloroplasttrnL intron from 46 differentVicia accessions, representing five of the nine sections of the genusVicia subg.Vicia sensuMaxted (1991a) were amplified by the Polymerase Chain Reaction (PCR) using oligonucleotide primers homologous to conserved regions intrnL. The products fell into two distinct groups; those of approximately 250 nt and those of around 450 nt in length. Of these, products from 17 differentVicia species were cloned and their nucleotide sequences determined. Multiple alignments were assembled and phylogenetic trees constructed by the weighted least-squares distance method. ALathyrus latifolius trnL intron sequence was used as an outgroup. The resulting trees clearly group and separate the sectt.Narbonensis, Bithynica andFaba species but were less able to distinguish species from sectt.Hypechusa andPeregrinae. Based on these sequence data,V. faba appears to be more distant from sect.Narbonensis than sectt.Hypechusa andPeregrinae. The results are in general agreement with a recent treatment ofVicia subg.Vicia (Maxted 1993) and lend further support to placingV. faba in the monospecific sect.Faba.
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    Isoenzyme variation in the wild relatives ofVicia faba (Fabaceae) (1998)
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    Plant systematics and evolution 213 (1998), S. 173-186 
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    ISSN: 1615-6110
    Keywords: Fabaceae ; Vicia ; sect.Bithynicae ; sect.Narbonensis ; Allozymes ; genetic diversity ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Electrophoretic analysis of five enzyme systems, LAP, PGI, SKDH, SOD and 6-PGDH, among 102Vicia accessions representingV. bithynica and seven species of theV. narbonensis complex, namelyV. eristalioides, V. kalakhensis, V. johannis, V. galilaea, V. serratifolia, V. narbonensis andV. hyaeniscyamus, has been performed. The recorded variation was tentatively assigned to 41 allelic genes at eight loci; intraspecific variation was observed in all species except forV. eristalioides. The results obtained were compared with the corresponding data reported earlier forV. faba. Hierarchical grouping of the investigated taxa, includingV. faba, was based onNei's genetic identities calculated from the allozyme frequency data.Vicia faba andV. bithynica were shown to be most distantly related to one another and to the remaining species investigated.Vicia serratifolia appeared to be a peripheral member of theV. narbonensis complex. The results are discussed with reference to genetic diversity and taxonomic relationships of the species under study.
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    Comparison of PCR-RFLP analysis of the ITS region with morphological criteria of various strains of Dunaliella (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 573-580 
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    ISSN: 1573-5176
    Keywords: Dunaliella ; ITS ; PCR ; RFLP ; strains ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genus Dunaliella comprises 28 species defined primarily by morphological and physiological criteria, which vary considerably depending on growth conditions. Concomitantly, the taxonomic status of various species is uncertain. To confirm the taxonomic identity and to better understand the relationship within Dunaliella, seven taxa ( D. salina, D. bardawil, D. tertiolecta, D. parva, D. viridis, D. lateralis, D. peircei) were compared using RFLP analysis of the nuclear rDNA repeats, specifically the internal transcribed spacer regions, including the 5.8S rRNA gene. Volvox aureus was used as an outgroup. A single ITS PCR amplification product was obtained for each taxon. An ITS fragment of ca. 640 bp was present in all the taxa within the subgenus Dunaliella, except for D. salina CCMP 1303 (ca. 540 bp) and D. lateralis (subgenus Pascheria) (ca. 600 bp). A cluster analysis based on the presence or absence of bands generated by digestion of the PCR product with 8 restriction endonucleases (DpnI, HhaI, EcoRI, PvuII, TaqI, HaeIII, MspI, StyI) revealed no correlation between the genetic relationship inferred from the ITS-RFLP data and the morpho-physiological attributes used for taxonomy. In addition, differences in morphology, physiology and in the length and restriction fragment patterns of the ITS region of D. salina CCMP 1303 suggest that this strain does not belong to Dunaliella.
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    A new species ofCortinarius sect.Sericeocybe from Japan (1998)
    Springer
    Mycoscience 39 (1998), S. 333-335 
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    ISSN: 1618-2545
    Keywords: Cortinarius prunicola ; Cortinarius Sect.Sericeocybe ; new species ; Rosaceae ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cortinarius prunicola sp. nov., found in orchards and plantations ofPrunus mume, is described and illustrated. It is characterized by its dry and violet-white carpophores, unpleasant odor, and its close association withP. mume in spring and early summer. The differences betweenC. prunicola and similar species are briefly discussed.
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    Unusual central nervous system toxicity in a phase I study of N1N11diethylnorspermine in patients with advanced malignancy (1997)
    Springer
    Investigational new drugs 15 (1997), S. 227-234 
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    ISSN: 1573-0646
    Keywords: diethylnorspermine ; phase I ; pharmacokinetics ; CNS toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract The objectives of this study were to determine the dose limiting toxicity (DLT) and other major toxicities, the maximum tolerated dose (MTD) and the human pharmacokinetics of N1N11diethylnorspermine (DENSPM), a new polyamine analog which in experimental systems inhibits the biosynthesis of intracellular polyamines and promotes their degradation by inducing the enzyme spermine/spermidine N-acetyl transferase. These objectives were incompletely achieved because of the occurrence of an unusual syndrome of acute central nervous system toxicity which forms the basis of the present report. Fifteen patients with advanced solid tumors were entered into a phase I study of DENSPM given by a 1h i.v. infusion every 12h for 5 days (10 doses). The starting dose was 25 mg/m2/day (12.5 mg/m2/dose) with escalation by a modified Fibonacci search. Doses of 25 and 50 mg/m2/day were tolerated with only minor side effects of facial flushing, nausea, headache and dizziness (all grade I). At doses of 83 and 125 mg/m2/day, a symptom complex of headache, nausea and vomiting, unilateral weakness, dysphagia, dysarthria, numbness, paresthesias, and ataxia, was seen in 3 patients, one after 2 courses of 83 and 2 after 1 course of 125 mg/m2/day. This syndrome occurred after drug administration was complete and the patients had returned home. Lesser CNS toxicity was seen in 2 other patients at lower daily doses. Preliminary pharmacokinetics of DESPM measured in plasma by HPLC in 8 patients showed linearity with dose and a rapid plasma decay with a t2 of 0.12h. We conclude that great caution is warranted in administering DENSPM on this schedule at doses of ≥ 83 mg/m2/day.
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    Depsipeptide (FR901228, NSC-630176) pharmacokinetics in the rat by LC/MS/MS (1997)
    Springer
    Investigational new drugs 15 (1997), S. 195-206 
    Details
    ISSN: 1573-0646
    Keywords: depsipeptide ; electrospray LC/MS/MS ; pharmacokinetics ; oral absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Depsipeptide, a cyclic peptide (FR), isolated from Chrombacterium violaceum strain WB968 by Fujisawa Company during a screening program for anti-oncogene agents, possesses potent antitumor activity against human tumor cell lines and xenografts. This compound has been selected for preclinical and early clinical development by the National Cancer Institute. The pharmacokinetics and oral bioavailability of this depsipeptide in the rat were investigated in the present study. A sensitive and specific electrospray LC-tandem mass spectrometry method was first developed and validated for the analysis of this depsipeptide in plasma using t-boc-α-d-glutamic acid benzyl ester as the internal standard. The routine sensitivity limit was 1 or 10 ng/ml using 1.0 or 0.1 ml of plasma sample. The within-run CV values were 11.8, 17.9, 11.0, and 5.0% at 1, 10, 100, and 500 ng/ml levels, respectively, with corresponding accuracy of 94.4, 109, 95, and 97% (all n=6). A formulation based on ethanol, normal saline and PEG400 was then developed and Fischer rats were given this formulated drug separately by intravenous and oral route. Plasma drug concentrations were measured by this method and pharmacokinetics were analyzed by the standard techniques. Plasma concentration-time profiles were found to follow a biexponential decline with a mean terminal t1/2 of 97 min and mean total clearance (CLt) of 425.3 ml/min/kg following iv dosing at 10 mg/kg. Following oral dosing at 50 mg/kg, the peptide was absorbed but produced erratic drug levels also with a bioavailability of 15.6%. Thus, active plasma concentrations can be produced up to 3 hrs in the rat following a single dose at 10 mg/kg and the peptide represents one of the very few orally absorbed peptides reported.
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    Pharmacokinetic and phase I studies of brequinar (DUP 785; NSC 368390) in combination with cisplatin in patients with advanced malignancies (1998)
    Springer
    Investigational new drugs 16 (1998), S. 19-27 
    Details
    ISSN: 1573-0646
    Keywords: phase I ; brequinar ; DUP 785 ; cisplatin ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Brequinar (DUP 785; NSC 368390) is a quinoline carboxylic acid derivative that inhibits pyrimidine synthesis at the level of dihydro-orotate dehydrogenase and revealed synergy with cisplatin in preclinical models. In this study investigating the pharmacokinetic and toxicity of brequinar in combination with cisplatin, patients were initially treated with weekly brequinar, in combination with an every-three-week administration of cisplatin. Due to toxicity, the schedule was modified to a 28-day cycle with brequinar given on days 1, 8, 15, and cisplatin on day 1. A total of 24 patients (16 male, 8 female; median age 57; median performance status 1) received 69 courses of therapy. Six dose levels were explored, with cisplatin/ brequinar doses, respectively, of 50/500, 50/650, 50/860, 60/860, 75/650, and 75/860 mg/m2. The serum concentration versus time curves for brequinar were biphasic. A comparison of the pharmacokinetic results after the first and third doses of brequinar indicate that the presence of 50, 60, and 75 mg/m2cisplatin did not change the protein binding and the pharmacokinetics of brequinar in any of the three brequinar-dose groups. Total cisplatin plasma pharmacokinetic followed a triphasic-shape curve and unbound cisplatin decayed at a very rapid rate. Since pharmacokinetic parameters for total cisplatin in this study were similar to those reported in the literature, the presence of brequinar is unlikely to alter the pharmacokinetics of cisplatin. Main dose-limiting toxicities included myelosuppression (including neutropenia and thrombocytopenia) and mucositis. Cisplatin/brequinar doses of 50/500, 50/650, 50/860, 60/860, 75/650, and 75/860 mg/m2, were associated with dose limiting toxicity in 0/3, 1/3, 1/3, 1/3, 2/4, 2/5, and 4/6 patients, respectively. This study shows that co-administration of brequinar and cisplatin does not affect the pharmacokinetic properties of either drug and that the MTDs of cisplatin/brequinar combinations are 60/860 mg/m2 or 75/650 mg/m2. From this study, we conclude that full dose of 75 mg/m2 cisplatin (day 1) can be administered with 650 mg/m2 brequinar (days 1, 8 and 15) without significant modifications of individual drug pharmacokinetic parameters.
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    Phase I clinical and pharmacokinetic trial of the podophyllotoxin derivative NK611 administered as intravenous short infusion (1998)
    Springer
    Investigational new drugs 16 (1998), S. 319-324 
    Details
    ISSN: 1573-0646
    Keywords: NK611 ; dimethylaminoetoposide ; Phase I ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Background: NK611 is a novel podophyllotoxin derivative. Compared with etoposide, NK611 carries a dimethyl-amino group at the D-glucose moiety. The antitumor activity of NK611 showed to be equal or superior to etoposide in a variety of in vitro and in vivo tumor models. The aim of our present study was to determine the maximum tolerated dose and the dose-limiting toxicities of NK611 administered as intravenous infusion over 30 min every 28 days. Patients and methods: 45 patients (7 female, 38 male; median age 54 [range 37–73]) were enrolled. In a first stage, NK611 was administered without hematopoietic growth factor support; in a second stage, G-CSF was used for further dose escalation. Toxicities were assessed using WHO-criteria. Results: Initially, the dose was escalated from 60 mg/m2 to 120 mg/m2. In a second patient cohort, doses were further escalated with G-CSF support with doses ranging from 140 mg/m2 to 250 mg/m2. Dose-limiting toxicities were granulocytopenia and thrombocytopenia. Non-hematologic toxicities consisted of alopecia, mild nausea, and infection. Four partial responses were observed: two at 200 mg/m2 (pleural mesothelioma, response duration 7 months, and non-small cell lung cancer, response duration 13 months), and two at 250 mg/m2 (hepatocellular carcinoma, response duration 7 months, and non-small cell lung cancer, response duration 2 months). Pharmacokinetic analyses were performed in all patients. Using an open 3-compartment model, the terminal half-life (t1/2γ) was 14.7 ± 3.7 h. The AUC at 250 mg/m2 was determined to be 330 ± 147 μg/mlh, the plasma clearance of NK611 was 16.2 ± 8.2 ml/min · m2 and the Vss was 16.8 ± 3.3 l/m2. Protein binding of NK611 was 98.7%. Conclusion: the recommended dose for clinical Phase II studies is 120 mg/m2 without G-CSF support and 200 mg/m2 with G-CSF support.
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    Decomposition of litter of three mudflat annual species in a northern prairie marsh during drawdown* (1997)
    Springer
    Plant ecology 129 (1997), S. 141-148 
    Details
    ISSN: 1573-5052
    Keywords: Aster ; Atriplex ; Chenopodium ; nitrogen ; phosphorus ; roots ; shoots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The loss of dry mass, nitrogen and phosphorus from shoot and root litter of mudflat annuals was examined in a series of experimental marshes in the Delta Marsh, Manitoba, Canada. Litter bags containing shoot material of three mudflat annuals (Aster laurentianus Fern., Atriplex patula L., and Chenopodium rubrum L.) were placed on the sediment surface of the marshes under drawdown conditions. In addition, litter bags containing root material of these three species were shallowly buried. Approximately 70% and 50% of both shoot and root litter, respectively, was still present after one year in the field. During the second year when the marshes were flooded, shoot and root litter lost an additional 20% and 0% of their mass, respectively. Except for Chenopodium roots, which accumulated nitrogen and phosphorus during both years, shoot and root litter lost from 0 to 50% of their nitrogen and phosphorus early in the first year, with levels generally remaining constant through the remainder of the study period. Our results indicate that mudflat annual litter decomposed slowly and would provide abundant habitat for aquatic invertebrates when these marshes were reflooded. However, most nutrient loss took place in the first year when the litter was unflooded, with little loss occurring in the second year when flooded.
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    URL: http://dx.doi.org/10.1023/A:1009708113161
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    Molecular markers for the detection of the wheat leaf rust resistance gene Lr10 in diverse genetic backgrounds (1997)
    Springer
    Molecular breeding 3 (1997), S. 65-74 
    Details
    ISSN: 1572-9788
    Keywords: leaf rust ; molecular marker ; receptor-like kinase ; resistance breeding ; resistance gene ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We recently showed that the Lr10 wheat leaf rust resistance gene cosegregated with the candidate resistance gene Lrk10 which encodes a putative receptor-like kinase. The aim of this study was to develop Lrk10-derived molecular markers for the detection of the Lr10 gene in breeding material. Different subfragments of Lrk10 were tested as RFLP markers for the Lr10 resistance gene. The most specific fragment (Lrk10-6) was converted into the PCR-based STS marker STSLrk10-6. Both the RFLP and the STS marker did not give a signal with near isogenic lines containing a different Lr gene. The applicability of these markers for the detection of Lr10 in genetically diverse material was tested with 62 wheat and spelt breeding lines, mostly from European breeding programmes. Twelve varieties known to have Lr10 showed the same alleles as the originally characterized line ThatcherLr10. Most of the lines with unknown composition at the Lr10 locus had a null allele with both the RFLP marker Lrk10-6 and the marker STSLrk10-6 whereas 20% of the lines had a different allele. For six lines, including a traditional spelt variety derived from a landrace, both markers showed the same allele as Thatcher Lr10. Artificial infections of these lines with an isolate avirulent on Lr10 resulted in a hypersensitive reaction of all these lines, indicating also the presence of the Lr10 resistance gene. These data demonstrate that the markers derived from sequences of Lrk10 are highly specific for the Lr10 gene in breeding material of very diverse genetic origin. The markers will allow the defined deployment of Lr10 in wheat breeding programmes and will contribute to the elucidation of the role of Lr10 in polygenic resistances against leaf rust.
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    URL: http://dx.doi.org/10.1023/A:1009619905909
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    A molecular marker associated with the H21 Hessian fly resistance gene in wheat (1997)
    Springer
    Molecular breeding 3 (1997), S. 177-181 
    Details
    ISSN: 1572-9788
    Keywords: bulked segregant analysis ; H21 ; near-isogenic lines (NILs) ; RAPD ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Near-isogenic lines in conjunction with bulked segregant analysis were used to identify a DNA marker in wheat (Triticum aestivum L.) associated with the H21 gene conferring resistance to biotype L of Hessian fly [Mayetiola destructor (Say)] larvae. Near-isogenic lines were developed by backcross introgression BC3F3:4 (‘Coker 797’ * 4 / ‘Hamlet’) and differed by the presence or absence of H21 (on 2RL) derived from ‘Chaupon’ rye (Secale cereale L.). Bulked DNA samples were prepared from near-isogenic lines and BC3F2 population individuals segregating for reaction to Hessian fly biotype L and screened for random amplified polymorphic DNA markers using 46 10mer primers. Random-amplified polymorphic DNA markers from resistant and susceptible individuals and parental lines were scored and these data were used to identify a 3 kb DNA fragment that was related to the occurrence of H21. This fragment was amplified from DNA isolated from Hamlet, a near-isogenic line carrying 2RL, and bulked DNA from resistant BC3F2 individuals, but not from the recurrent parent Coker 797 or DNA bulks from susceptible BC3F2 plants. Analysis of 111 BC3F2 segregating individuals and BC3F2:3 segregants confirmed the co-segregation of the 3 kb DNA marker with the H21 resistance gene to Hessian fly. Use of this marker could facilitate more rapid screening of plant populations for Hessian fly resistance and monitoring the introgression of H21.
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    Zooplankton nutrition: recent progress and a reality check (1998)
    Springer
    Aquatic ecology 32 (1998), S. 261-279 
    Details
    ISSN: 1573-5125
    Keywords: phosphorus ; fatty acid ; growth ; life history ; food limitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evidence suggests that marine and freshwater zooplankton generally experience food levels above subsistence values in terms of carbon. However, the quality of this food may be poor due to an insufficiency of other essential nutrients. In this review, we examine recent progress in three main areas of food quality research: (1) elemental (especially P) limitation, (2) digestion resistance, and (3) biochemical (especially fatty acids) limitation. We evaluate laboratory and field evidence in each of these areas, look at new evidence about the life history implications of the elemental limitation hypothesis, and suggest future avenues for research. From a rather large number of seemingly heterogeneous studies, a single consistent picture of food quality emerges: both P and essential fatty acids are predicted to be important dietary factors, but at different places and times. Nevertheless, despite an abundance of valuable laboratory studies, our knowledge of food quality limitation in the field is still poor.
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    Taxonomic review of the species of Pterocladia (Gelidiales, Rhodophyta) (1998)
    Springer
    Journal of applied phycology 10 (1998), S. 237-251 
    Details
    ISSN: 1573-5176
    Keywords: Gelidiales ; Gelidiella ; Gelidium ; Pterocladia ; Pterocladiella ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Segregating Pterocladiella from Pterocladia stimulated new taxonomic studies of the species originally assigned to Pterocladia. A total of 28 species are ascribed to the genus, one of them with doubts. Thirteen of the 27 names are synonyms. Three of the remaining 14 species belong with Gelidium, including G. americanum, G. mcnabbianum (Dawson) comb. nov. and G. musciformis. Seven other species belong with Pterocladiella, including P. bartlettii (Taylor) comb. nov., P. bulbosa, P. caerulescens, P. caespitosa (Kylin) comb. nov., P. caloglossoides (Howe) comb. nov., P. capillacea and P. melanoidea. Two species are retained in Pterocladia, the type P. lucida and P. rectangularis. Two others, P. heteroplatos and P. media are placed in incertae sedis as additional studies of fertile materials are needed to determine their generic status. The genus Pterocladia now appears to include two large-sized species restricted to Australia-New Zealand. Pterocladiella has 8 small-sized species (including P. minima), mainly inhabiting tropical and subtropical waters. Future research documenting sexual reproduction in Gelidiella and solving the presently recognized heterogeneity in Gelidium will help to trace the relationships between Pterocladiella and these two genera.
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    Pharmacokinetic–Pharmacodynamic Modeling of Doxacurium: Effect of Input Rate (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 23-37 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; pharmacodynamics ; neuromuscular blocking agents ; doxacurium ; input rate ; intravenous ; bolus ; infusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract One of the basic assumptions in pharmacokinetic–pharmacodynamic modeling (PK–PD) is that drug equilibration rate constant between plasma concentration and effect (Ke0 ) is not changed by input rate. To test this assumption in a clinical setting, a 25 μg/kg iv dose of doxacurium was administered either by bolus injection or 10-min infusion to 15 anesthetized patients. Neuromuscular function was monitored using train-of-four stimulation of the ulnar nerve. For the short infusion dose, arterial concentrations were measured at 1-min intervals during infusion and at frequent intervals thereafter. Following the iv bolus dose, the early PK profile of doxacurium was investigated by measuring doxacurium arterial concentrations every 10 sec during the first 2 min and at frequent intervals thereafter. PK–PD modeling was performed using nonparametric approach with and without including a finite receptor concentration (Rtot ) in the effect compartment. Kinetic parameters were unchanged. For the bolus and the infusion, Ke0 values were 0.053±0.006 and 0.056±0.009 min −1 , respectively. Using the Rtot model, corresponding Ke0 values were 0.148±0.016 and 0.150±0.024, respectively. The relatively faster Ke0 obtained with the Rtot model is compatible with the high potency of doxacurium. Our results show that PK–PD parameters derived with either a bolus or an infusion mode of administration are equally reliable.
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    Mathematical Formalism for the Properties of Four Basic Models of Indirect Pharmacodynamic Responses (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 107-123 
    Details
    ISSN: 1573-8744
    Keywords: pharmacodynamic responses ; pharmacokinetics ; differential equations ; drug ; indirect response models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Four basic models for characterizing indirect pharmacodynamic responses were proposed previously and applied using differential equations. These models consider inhibition or stimulation by drug of the production or loss of mediators or response variables. This report develops partially integrated solutions for these models which allow more detailed examination of the roles of model parameters and pharmacokinetic functions in affecting the time course of drug effects. Because of the nonlinear Hill function, the solutions are represented by means of definite integrals containing kinetic and dynamic functions. These solutions allow a qualitative examination, using calculus, of how response is controlled by Dose. IC50 or SC50, Imax or Smax, and kout for drugs exhibiting monotonic or biphasic disposition. Characteristics of the response curves that were identified include shape, maximum or minimum, and changes with the above parameters and time. These relationships, together with simulation studies, provide a fundamental basis for understanding the temporal aspects of the basic indirect response models.
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    Pharmacokinetics and Relative Bioavailability of Carboxyamido-Triazole with Respect to Food and Time of Administration: Use of a Single Model for Simultaneous Determination of Changing Parameters (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 673-687 
    Details
    ISSN: 1573-8744
    Keywords: carboxyamido-triazole ; bioavailability ; chronopharmacology ; pharmacokinetics ; food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Carboxyamido-triazole (CAI) is an anti-invasive, antimetastatic, antiangiogenic agent in clinical development for cancer treatment. It has been postulated that food might enhance the oral absorption of micronized CAI based on an apparent discrepancy in steady state maximum concentrations when taken without regard to meals vs. fasting. The purpose of this study was to determine if a standardized meal affects the absorption and pharmacokinetics of this agent. Twelve patients with refractory cancers and good end organ function were randomized to receive two doses of CAI (250 mg/m 2 ) with and without a standardized high fat meal. One cohort of 6 patients received these doses at 9 AM, and the remaining 6 patients received CAI at 9 PM. Blood was obtained prior to each dose, and serially thereafter. A series of pharmacokinetic (PK) models were fit to the concentration–time data. PK parameters were ultimately calculated using a model which allows simultaneous estimation of parameters from both test doses using nonlinear least squares analysis with ADAPT II. This model estimates independent absorption rate constants and relative fraction absorbed for each condition. AUC 0–t was determined using the trapezoidal method, extrapolated to infinity, and used to calculate the relative bioavailability. No significant differences in PK parameters were noted between the morning and evening cohorts. However, the relative bioavailability, as measured by AUC 0–∞, of CAI was significantly increased when administered with a high fat meal compared to fasting (138.9 vs. 52.2 μg * hr/ml; p=0.0005). The magnitude of the increase in relative bioavailability of CAI taken with food could have profound implications for patients who may inadvertently take this medication shortly after eating.
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    Pharmacokinetic-Based Minibolus Delivery as an Alternative to Continuous Infusion for Drugs That Exhibit a Biophase Lag (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 191-208 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; pharmacodynamics ; frequency response ; biophase models ; infusion pumps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The presence of a biophase compartment in a pharmacokinetic model indicates that the response to an administered dose of drug is damped such that the time to peak effect occurs after the peak concentration in the bloodstream. This phenomenon, which is common to most intravenous anesthetic agents, can be exploited by a drug delivery method that administers minibolus doses of drug rather than a continuous infusion. Through analysis of the frequency response behavior of the biophase compartment, a bolus magnitude and dose frequency or interval (1/frequency) can be chosen such that the oscillation in drug effect is minimized even though the plasma concentration may be changing significantly with each supplemental dose. A pharmacokinetic and pharmacodynamic based method for calculating the bolus dose size and dosing interval is presented. The trade-off between dose interval and change in drug effect is exemplified through computer simulation of this strategy applied to delivery of the neuromuscular blocking agent pancuronium. The method provides a repetitive perturbation to the pharmacokinetic and pharmacodynamic system that can aid in model parameter identification during closed loop applications.
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    A Tracer Interaction Method for Nonlinear Pharmacokinetics Analysis: Application to Evaluation of Nonlinear Elimination (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 569-593 
    Details
    ISSN: 1573-8744
    Keywords: tracer method ; nonlinear kinetics ; Michaelis-Menten ; pharmacokinetics ; erythropoietin ; binding ; drug receptors ; receptor binding ; drug elimination ; modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A drug tracer is most commonly applied to get information about the pharmacokinetics (PK) of a drug that is not confounded by an endogenously produced drug or an unknown drug input. An equally important use of tracers that has not been fully recognized is their use in the study of nonlinear PK behavior. In the present study a system analysis is applied to examine the interaction between drug molecules characteristic and intrinsic to any nonlinear process which enables the nonlinearity to be identified and modeled using a drug tracer. The proposed Tracer Interaction Methodology (TIM) forms a general developmental framework for novel methods for examining nonlinear phenomena. Such methods are potentially much more sensitive and accurate than previous methods not exploiting the tracer principle. The methodology proposed is demonstrated in a simulation study and with real data in a specific implementation aimed at determining the Michaelis-Menten (MM) parameters of nonlinear drug elimination while accounting for drug distribution effects. The simulation study establishes that the TIM-based, MM parameter evaluation produces substantially more accurate parameter estimates than a nontracer (NT) conventional method. In test simulations the accuracy of the TIM was in many cases an order of magnitude better than the NT method without evidence of bias. The TIM-based, MM parameter estimation methodology proposed is ideally suitable for dynamic, non-steady-state conditions. Thus, it offers greater applicability and avoids the many problems specific to steady state evaluations previously proposed. TIM is demonstrated in an evaluation of the nonlinear elimination behavior of erythropoietin, a process that likely takes place via receptor-based endocytosis. Due to its high sensitivity, accuracy, and intrinsic nonlinearity the TIM may be suitable for in-vivo studies of receptor binding of the many biotechnology produced peptide drugs and endogenous compounds displaying receptor-mediated elimination.
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    Structure of populations of wheat powdery mildew (Erysiphe graminis DC f.sp. tritici Marchal) in Central Europe in 1993–1996: I. Dynamics of virulence (1998)
    Springer
    European journal of plant pathology 104 (1998), S. 537-544 
    Details
    ISSN: 1573-8469
    Keywords: Central Europe ; powdery mildew ; wheat ; complexity of pathotypes ; Erysiphe graminis f.sp. tritici ; stabilizing selection ; survey ; virulence analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In 1993–1996, the virulence of regional populations of the wheat powdery mildew pathogen (Erysiphe graminis DC f. sp. tritici Marchal) from the Czech Republic, Austria, Hungary and Slovakia against 13 resistance genes was investigated. The populations differed mainly at the regional level. Populations from the Czech Republic, mainly from the western regions, showed higher values of virulence against the Pm4b gene. Lower frequency of virulence against Pm4b was found in Austria, and the lowest value was observed in Hungary. The differences in frequencies of virulence against Pm4a and Pm4b showed a similar geographic pattern across the four countries: a continuous decline from west to east and from north to south. Virulence against Pm2 decreased in all countries considered; virulence to pm5, Pm6, Pm8 and Mli was high throughout. Genes and gene combinations that can ensure a relatively effective biological protection against this pathogen across Central Europe at present are Pm3b, Pm2+Mld and Pm1+2+9. Czech and Slovak populations were the most complex: virulence complexity reached a maximum in Slovakia in 1994. A similar evolution, though less significant, was observed in the Czech Republic. Data on complexity of isolates suggest that Central European populations of wheat powdery mildew tend to reach an intermediate level representing the optimal number of virulence genes. This process is probably a consequence of stabilizing selection.
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    Characterization of phenotypically distinct strains of Xanthomonas axonopodis pv. citri from Southwest Asia (1998)
    Springer
    European journal of plant pathology 104 (1998), S. 477-487 
    Details
    ISSN: 1573-8469
    Keywords: citrus bacterial canker ; detection ; epidemiology ; monoclonal antibodies ; variability ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Strains of Xanthomonas axonopodis pv. citri were isolated from Mexican lime (Citrus aurantifolia) trees in several countries in southwest Asia. These strains produced typical erumpent bacterial canker lesions on Mexican lime but not on grapefruit (C. paradisi). Lesions on grapefruit were watersoaked and blister-like in contrast to the typical erumpent lesions seen after artificial inoculation with all described pathotypes of X. axonopodis pv. citri. This group of strains hydrolysed gelatin and casein and grew in the presence of 3% NaCl as is typical of X. axonopodis pv. citri pathotype A. RFLP analyses and DNA probe hybridization assays also gave results consistent with X. axonopodis pv. citri pathotype A. Metabolic fingerprints prepared with the Biolog® system showed similarities as well as differences to X. axonopodis pv. citri pathotype A. In spite of the physiological and genetic similarities to pathotype A of X. axonopodis pv. citri, these strains had no or very little affinity for polyclonal antiserum prepared against any of the reference strains of X. axonopodis pv. citri and also did not react with monoclonal antibody A1, an antibody that detects all strains of pathotype A of X. axonopodis pv. citri. These strains were also insensitive to bacteriophage Cp3 like X. axonopodis pv. citri pathotype A and unlike X. axonopodis pv. citri pathotype B. We conclude that these strains, designated Xcc-A*, represent a variant of X. axonopodis pv. citri pathotype-A with pathogenicity limited to C. aurantifolia. The existence of extensive genotypic and phenotypic variation within pathotype A of X. axonopodis pv. citri was unexpected and further complicates the systematics of this species.
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    Mixed Effect Modeling of Sumatriptan Pharmacokinetics During Drug Development. I: Interspecies Allometric Scaling (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 149-167 
    Details
    ISSN: 1573-8744
    Keywords: sumatriptan ; interspecies allometric scaling ; brain weight ; metabolized drug ; pharmacokinetics ; mixed effect modeling ; NONMEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Allometric scaling is an empirical examination of the relationships between the pharmacokinetic parameters and size (usually body weight), but it can also involve brain weight for metabolized drug. Through all species, the protein binding of sumatriptan is similar (14-16%). and its metabolic pathway undergoes extensive oxidative deamination involving the monoamine oxidase A isoenzyme. These similarities across species suggested the possible relevance of an allometric analysis. Toxicokinetic data were collected from rats, pregnant rabbits, and dogs in animal pharmacokinetic studies where sumatriptan was administered intravenously to the animals at doses of 5 mg/kg. 0.25 mg/kg, and 1 mg, kg, respectively. Animal data were pooled and analyzed in one step using a mixed effect modeling (population) approach. The kinetic parameters predicted in any species were close to the observed values by species: 77 L/hr vs. 80 L/hr in man for total clearance, 137 L vs. 119 L for distribution volume at steady state. The value of the mixed effect modeling approach compared to the two-step method was demonstrated especially with the possibility of including covariates to describe the status of animal (e.g., pregnancy) in the model. Knowledge of the animal kinetics, dynamics, and metabolism of a drug contributes to optimal and expeditious development. Valuable information for the design of the first-dose-in-man study may emerge from more creative data analysis based on all the information collected during the preclinical and ongoing nonclinical evaluation of a new drug.
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    URL: http://dx.doi.org/10.1023/A:1025728028890
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    Quantitative Structure-Pharmacokinetics Relationships: I. Development of a Whole-Body Physiologically Based Model to Characterize Changes in Pharmacokinetics Across a Homologous Series of Barbiturates in the Rat (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 277-312 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; physiologically based model ; homologous series ; barbiturates ; parameter optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract As pan of an overall program to develop a framework for evaluating the contribution of structural and physicochemical properties to pharmacokinetics, the distribution kinetics of nine 5-n-alkyl-5-ethyl barbituric acids in arterial blood and 14 tissues (lung, liver, kidney, stomach, pancreas, spleen, gut, muscle, adipose, skin, bone, heart, brain, testes) was examined after iv bolus administration in rats. The barbituric acids studied form a true homologous series; therefore any differences in pharmacokinetics, noted between congeners, can be directly linked to the increase in lipophilicity, resulting from the addition of a methylene group. A whole-body physiologically based pharmacokinetic model has been developed, assuming most of the tissues to be well-stirred compartments. Brain and testes, in which distribution for the lower homologues was permeability rate-limited, were represented by two compartments. For each homologue, the model parameters have been optimized, using the tissue concentration–time data. The initial distribution processes in the system were very rapid, making it quite stiff, and essentially over before the first samples were taken. A progressively increasing redistribution from lean tissues into adipose on ascending the homologous series was observed, characterized by a tendency for a progressive decrease in the magnitude of the concentration–time profiles for some of the lean and well-perfused tissues, an increase in the adipose concentration–time profile, and an increase in the time to reach the maximum adipose concentration. A shift from permeability rate limitation to perfusion rate limitation of the distribution processes for brain and testes, as well as an increase in the intrinsic hepatic clearance and decrease in the renal clearance with the increase of lipophilicity of the homologues, were quantified. An increase in the total unbound volume of distribution on ascending the homologous series was also observed. Muscle was found to be the major drug depot at steady state, accounting for approximately 50% of the total unbound volume of distribution, regardless of the lipophilicity of the homologue; the unbound volume of distribution of adipose increases more than 10-fold with the increase of lipophilicity.
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    URL: http://dx.doi.org/10.1023/A:1025771608474
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    New Mathematical Implementation of Generalized Pharmacodynamic Models: Method and Clinical Evaluation (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 313-348 
    Details
    ISSN: 1573-8744
    Keywords: pharmacodynamics ; pharmacokinetics ; generalized models ; intraindividual variability ; verapamil ; norverapamil ; S-verapamil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new method and experimental design are presented to unambiguously estimate the transduction function (Φ) and the conduction function (ψ) of the generalized pharmacodynamic model: E = Φ(ψ*r), when measured pharmacokinetic response r is (i) drug plasma concentration and (ii) drug input rate into the systemic circulation. Φ relates the observed pharmacologic effect E to the concentration at the effect site: ce = (ψ*r), ψ defines transfer of drug from plasma site to effect site or from input site to effect site, and * represents the convolution integral. The model functions ψ and Φ were expressed as cubic splines giving a very flexible description of those processes which is not biased by the structured assumptions of more conventional models, e.g., effect compartment models. The experimental design proposed addresses the problem of ambiguous identification of the model functions typical of these models; that is, there is more than one pair of very different functions describing the effect data collected after a single drug administration. We tested the hypothesis that the simultaneous fitting of at least two administrations allows the unambiguous identification of the model functions without the need for unlikely or cumbersome constraints. The performance of the mathematical implementation and the robustness of the methods with respect to measurement noise and possible failure of some assumptions, such as intraindividual variability, were tested by computer simulations. The method was then applied to the results of a clinical study of verapamil pharmacodynamics in 6 healthy subjects. Results of these studies demonstrated that the mathematical implementation does not introduce bias or artifact into the estimated functions and that the models and the proposed methods are suitable for application to clinical research. Two drug administrations were sufficient to unambiguously describe verapamil pharmacodynamics in the 6 human subjects studied.
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    URL: http://dx.doi.org/10.1023/A:1025723725312
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    Similarity or Discrepancy in Pharmacokinetic Parameter Estimation Between Bolus and Infusion Studies (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 471-476 
    Details
    ISSN: 1573-8744
    Keywords: steady-state volume of distribution ; statistical moment analysis ; pharmacokinetics ; infusion study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A recent study by Heatherington and Rowland showing discrepancies in steady-state volume of distribution (Vss) estimation of two barbiturates between bolus and infusion studies in rat hindlimb preparations was reviewed. Their rationale is that increasing the duration of administration may increase the accessibility for tissue distribution and thus increase Vss for compounds showing slow tissue uptake. Such a dosing-duration-dependent distribution concept is, however, inconsistent with the principle in linear kinetics that the fate or disposition function of any drug molecules is independent of time of administration and presence of other molecules. When their well-designed bolus studies were reanalyzed by including extrapolated outflow data from the last sampling time to infinity, the Vss values for the two barbiturates were found to be very similar to those obtained by the infusion method. Our analysis seems to validate a theoretical concept that parameter estimation is independent of the duration of administration in linear kinetics. A potential complication of using the bolus method to study Vss is presented.
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    URL: http://dx.doi.org/10.1023/A:1025745009925
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    Lumping of Whole-Body Physiologically Based Pharmacokinetic Models (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 21-46 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; whole body physiologically based model ; lumping ; system theory ; barbiturates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Lumping is a common pragmatic approach aimed at the reduction of whole-body physiologically based pharmacokinetic (PBPK) model dimensionality and complexity. Incorrect lumping is equivalent to model misspecification with all the negative consequences to the subsequent model implementation. Proper lumping should guarantee that no useful information about the kinetics of the underlying processes is lost. To enforce this guarantee, formal standard lumping procedures and techniques need to be defined and implemented. This study examines the lumping process from a system theory point of view, which provides a formal basis for the derivation of principles and standard procedures of lumping. The lumping principle in PBPK modeling is defined as follows: Only tissues with identical model specification, and occupying identical positions in the system structure should be lumped together at each lumping iteration. In order to lump together parallel tissues, they should have similar or close time constants. In order to lump together serial tissues, they should equilibrate very rapidly with one another. The lumping procedure should include the following stages: (i) tissue specification conversion (when tissues with different model specifications are to be lumped together); (ii) classification of the tissues into classes with significantly different kinetics, according to the basic principle of lumping above; (iii) calculation of the parameters of the lumped compartments; (iv) simulation of the lumped system; (v) lumping of the experimental data; and (vi) verification of the lumped model. The use of the lumping principles and procedures to be adopted is illustrated with an example of a commonly implemented whole-body physiologically based pharmacokinetic model structure to characterize the pharmacokinetics of a homologous series of barbiturates in the rat.
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    URL: http://dx.doi.org/10.1023/A:1023272707390
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    Bioavailability Assessment from Pharmacologic Data: Method and Clinical Evaluation (1997)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 25 (1997), S. 349-362 
    Details
    ISSN: 1573-8744
    Keywords: bioavailability ; pharmacologic data ; pharmacodynamics ; pharmacokinetics ; computer simulation ; verapamil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A novel method is described for assessing drug bioavailability from pharmacologic data. The method is based upon a generalized model for the relationship between the observed effect (E) and the input rate (f): E = Φ(ceδ * f), where * denotes convolution, ceδ is effect site unit impulse response (“amount” of drug at the effect site resulting from the instantaneous input of a unit amount of drug) and Φ is transduction function (relates “amount” of drug at the effect site to E). The functions Φ and ceδ are expressed as cubic splines for maximum versatility. Pharmacologic data collected after the administration of two different doses by iv infusion are analyzed simultaneously to estimate the function parameters. This experimental design addresses the fact that Φ and ceδ cannot be uniquely estimated from the results of a single dose experiment. The unknown f from a test treatment is then estimated by applying an implicit deconvolution method to the pharmacologic data collected during that treatment. The method was tested with simulated data. The method and the model were further evaluated by application to a clinical study of verapamil (V) pharmacodynamics in 6 healthy volunteers. Simulations showed that the method is accurate and precise in the presence of a high degree of measurement error, but large intrasubject variability in the model functions can result in biased estimates of the amount absorbed. The method produced reasonably accurate estimates of the V input rate and systemic availability (F) in the 6 human volunteers though there was a trend towards underestimation (estimated total F%=93.6±14 vs. the true F% of 100).
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    URL: http://dx.doi.org/10.1023/A:1025775809382
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    Population Pharmacokinetic Analysis of Mizolastine and Validation from Sparse Data on Patients Using the Nonparametric Maximum Likelihood Method (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 133-161 
    Details
    ISSN: 1573-8744
    Keywords: mizolastine ; pharmacokinetics ; population analysis ; zero-order absorption ; heteroscedastic variance ; NPML ; validation ; predictive distributions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A population analysis of the kinetics of mizolastine was performed from concentrations on 449 allergic patients, using the nonparametric maximum likelihood method (NPML). A two-compartment open model with zero-order absorption was used to describe the kinetics of mizolastine after oral administration. A heteroscedastic variance model was assumed for the error. To explain the kinetic variability, eight covariates were introduced in the analysis: gender, pharmaceutical dosage form, age, body weight, serum creatinine concentration, creatinine renal clearance, plasma levels of hepatic transaminases ASAT and ALAT. Their relationships to the kinetic parameters were studied by means of the estimated distribution of each kinetic parameter conditional on different levels of each covariate. An important interindividual kinetic variability was found for all parameters. Moreover, several kinetic parameters among which the duration of absorption were found to be influenced by pharmaceutical dosage form and gender. Body weight and creatinine renal clearance were found to have a little influence on the oral clearance and the smallest disposition rate constant. This population analysis was validated on a separate group of 247 other patients. For each observed concentration of this sample, a predictive distribution was computed using the individual covariates. Predicted concentrations and standardized prediction errors were deduced. The mean and variance of the standardized prediction errors were, respectively, 0.21 and 2.79. Moreover, in the validation sample, the predicted cumulative distribution function of each observed concentration was computed. Empirical distribution of these values was not significantly different from a uniform distribution, as expected under the assumption that the population model estimated by NPML is adequate.
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    URL: http://dx.doi.org/10.1023/A:1020505722924
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    Rapid Attainment of Steady State Plasma Drug Concentrations Within Precise Limits (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 319-328 
    Details
    ISSN: 1573-8744
    Keywords: anesthetic techniques ; continuous infusion ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We describe a method of rapidly obtaining a specified steady state plasma concentration of an intravenous drug within precise limits. The technique requires an initial bolus to raise the plasma concentration to the upper limit followed by a series of constant-rate infusions each of which is associated with a minimum plasma concentration equal to the tower limit. The infusion rate is stepped down when the plasma concentration returns to the upper limit. Computer simulation, based on the method, is used to generate plasma concentration–time curves with fluctuations of up to 10% about selected steady state concentrations of amrinone, esmolol, lidocaine, midazolam, propofol, and theophylline. The utility of this general approach to intravenous dosing and potential limitations of the method are discussed.
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    URL: http://dx.doi.org/10.1023/A:1023285426388
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    Fourth-Generation Model for Corticosteroid Pharmacodynamics: A Model for Methylprednisolone Effects on Receptor/Gene-Mediated Glucocorticoid Receptor Down-Regulation and Tyrosine Aminotransferase Induction in Rat Liver (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 289-317 
    Details
    ISSN: 1573-8744
    Keywords: methylprednisolone ; pharmacokinetics ; pharmacodynamics ; indirect response models ; glucocorticoid receptor ; tyrosine aminotransferase ; Northern hybridization ; mRNA ; down-regulation ; receptor recycling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A fourth-generation pharmacokinetic/pharmacodynamic (PK/PD) model for receptor/genemediated effects of corticosteroids was developed. Male adrenalectomized Wistar rats received a 50 mg/kg iv bolus dose of methylprednisolone (MPL). Plasma concentrations of MPL, hepatic glucocorticoid receptor (GR) messenger RNA (mRNA) and GR density, tyrosine aminotransferase (TAT) mRNA, and TAT activity in liver were determined at various time points up to 72 hr after MPL dosing. Down-regulation of GR mRNA and GR density were observed: GR mRNA level declined to 45–50% of the baseline in 8–10 hr, and slowly returned to predose level in about 3 days; GR density fell to 0 soon after dosing and returned to the baseline in two phases. The first phase, occurring in the first 10 hr, entailed recovery from 0 to 30%. The second phase was parallel to the GR mRNA recovery phase. Two indirect response models were applied for GR mRNA dynamics regulated by activated steroid-receptor complex. A full PK/PD model for GR mRNA/GR down-regulation was proposed, including GR recycling theory. TAT mRNA began to increase at about 1.5 hr, reached the maximum at about 5.5 hr, and declined to the baseline at about 14 hr after MPL dosing. TAT induction followed a similar pattern with a delay of about 1–2 hr. A transcription compartment was applied as one of the cascade events leading to TAT mRNA and TAT induction. Pharmacodynamic parameters were obtained by fitting seven differential equations piecewise using the maximum likelihood method in the ADAPT II program. This model can describe GR down-regulation and the precursor/product relationship between TAT mRNA and TAT in receptor/gene-mediated corticosteroid effects.
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    URL: http://dx.doi.org/10.1023/A:1023233409550
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    On a new species of Fabaeformiscandona KRSTIC, 1972 (Crustacea, Ostracoda) from China, with a preliminary checklist of Recent Chinese non-marine ostracods (1997)
    Springer
    Hydrobiologia 357 (1997), S. 117-128 
    Details
    ISSN: 1573-5117
    Keywords: taxonomy ; Ostracoda ; China ; ancient lakes ; saline lakes ; biogeography ; checklist ; Fabaeformiscandona danielopoli n.sp.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fabaeformiscandona danielopoli n.sp. isdescribed from the Chinese Lake Erhai, a freshwaterlagoon of the ancient saline lake Qinghai. The speciesbelongs to the acuminata-group of the genus andis characterized by the shape of both male and femalevalves and by the morphology of the female genitallobe and of lobe ‘a’ in the hemipenis. The new speciesis quite rare in its type locality and might beendemic to the ancient Qinghai basin. A checklist ofRecent non-marine Chinese ostracods is offered inappendix.
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    URL: http://dx.doi.org/10.1023/A:1003182720121
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    The nutrient content and the release of nutrients from fish food and faeces (1997)
    Springer
    Hydrobiologia 357 (1997), S. 165-171 
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    ISSN: 1573-5117
    Keywords: fish food ; faeces ; nutrient ; nitrogen ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fish food and faeces were fractioned into the differentcomponents of phosphorus and nitrogen. There was a rapid release ofphosphorus from the fish food and faeces and a decrease thereafterwhereas ammonium release was slow at first with the rate increasingwith time. Both temperature and pH affected the release of nutrientsfrom fish food and faeces. The release of phosphorus and nitrogen washigher at higher temperatures. The maximum release of phosphorus wasat pH 4.0 whereas nitrogen release was maximum at neutral (7.0) toalkaline (10.0) media.
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    URL: http://dx.doi.org/10.1023/A:1003147122847
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    Relations between planktivorous fish abundance, zooplankton and phytoplankton in three lakes of differing productivity (1997)
    Springer
    Hydrobiologia 363 (1997), S. 81-95 
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    ISSN: 1573-5117
    Keywords: phytoplankton ; zooplankton ; planktivorous fish ; phosphorus ; biomanipulation ; trophic interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Water chemistry, phytoplankton, zooplankton and fish populations werestudied over several years in three shallow, non-stratified lakes withdiffering nutrient loadings and fish communities in southwest Finland. LakePyhäjärvi was weakly mesotrophic in 1980–1996, LakeKöyliönjärvi was highly eutrophic in 1991–1996, andLake Littoistenjärvi was mesotrophic in 1993–1996 and eutrophicin 1992. In Lake Pyhäjärvi, natural year-class fluctuations ofvendace and smelt (range of combined biomass 5–28 kgha™1) caused significant variation in planktivory. The verydense fish stocks of Lake Köyliönjärvi (mainly roach, breamand smelt) were decimated from 〉175 kg ha™1 in 1991 toabout 50 kg ha−1 in 1996 by removal fishing. The roach stockof Lake Littoistenjärvi declined from about 71 kg ha−1 toabout 28 kg ha−1 during 1993–1996. In LakePyhäjärvi, strong stocks of planktivorous fish were accompaniedwith depressed crustacean zooplankton biomass, reduced role of calanoids andcladocerans, a low proportion of larger cladocerans (length 〉 0.5 mm),and a high chlorophyll level. In the lakes Littoistenjärvi andKöyliönjärvi, zooplankton was dependent on both fish andphytoplankton: in spite of dense fish stocks, a high crustacean biomassdeveloped in a phytoplankton peak year, but it was dominated by very smallcladocerans. In Lake Pyhäjärvi, late summer chlorophyllconcentration was predictable from total phosphorus in water and cladoceranbiomass (r2 = 0.68), both factors explaining roughlysimilar fraction of total variation. In combined data from all three lakes,chlorophyll was almost solely dependent on total phosphorus, while thecladocerans were regulated both from below by productivity and from above byfish. Our data from Pyhäjärvi lend support to consumer regulationof late summer phytoplankton; low chlorophyll values prevailed whenplanktivorous fish biomass was below 15 kg ha−1. In largeeutrophic lakes it may be difficult to reduce fish stocks to such a lowlevel: in Lake Köyliönjärvi, after six years of removalfishing, fish biomass still remained higher, and changes in plankton wereaccordingly small. Unexpectedly, in 1993–1996, phytoplankton biomassin Littoistenjärvi remained low in spite of low crustacean zooplanktonbiomass; submerged macrophytes probably regulated the water quality.
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    Tree-thinking and nemertean systematics, with a systematization of the Eureptantia (1997)
    Springer
    Hydrobiologia 365 (1997), S. 33-46 
    Details
    ISSN: 1573-5117
    Keywords: Phylogeny ; cladistics ; taxonomy ; systematics ; classification ; evolution ; history ; chronicle ; Nemertea ; Hoplonemertea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract I review how some influential nemertean systematistshave perceived and illustrated phylogenetic trees andargue that the nineteenth century nemerteantaxonomists still influence many contemporarynemertean taxonomists to a high degree. By showing hownineteenth century systematics differs from moremodern views on trees, I hope to convey the advantagesof a cladistic approach to tree-thinking and nemerteansystematics. Furthermore I propose a systematizationof the Eureptantia that illustrates the cladisticapproach to tree-thinking but, more importantly, isalso a better representation of eureptantic phylogenythan previous classifications.
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    URL: http://dx.doi.org/10.1023/A:1003174326275
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    Dissolved nutrient concentrations and loads in some upland streams of the English Lake District (1998)
    Springer
    Hydrobiologia 377 (1998), S. 85-93 
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    ISSN: 1573-5117
    Keywords: phosphorus ; nitrate ; silicon ; streams ; English Lake District
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Concentrations of soluble reactive phosphorus (SRP), nitrate, and soluble reactive silicon (SRSi) were monitored in 12 streams draining small catchments (〈10 km2) in the English Lake District. The catchments varied with respect to underlying geology, soil type and land cover. Average concentrations of SRP were in the range 0.5–11.2 μg P l-1, and estimated loads ranged from 0.01 to 0.14 kg P ha-1 a-1. The higher concentrations and loads were associated with catchments containing improved pasture. Mean streamwater concentrations of nitrate varied from 55 to 660 μg N l-1, while loads were in the range 0.8–9.6 kg N ha-1 a-1; no general dependence on catchment properties was discerned. Concentrations of SRSi were similar in all the streams (0.8–2 mg Si l-1), and annual loads were in the range 10–26 kg Si ha-1 a-1. Loads of all three nutrients were greatest during the winter, because of higher discharges, but in some catchments containing improved pasture, considerable transport of P also took place during the summer. Concentrations of nitrate in streams draining unimproved moorland catchments are approximately twice those reported for samples taken from similar streams in 1973 and 1974, possibly because of increased atmospheric deposition of inorganic nitrogen (ammonium and nitrate). Concentrations of SRP in such streams were similar to those reported for the earlier samples. Comparisons of stream loads of SRP and nitrate with estimated inputs suggest that catchment soils retain substantial amounts of these nutrients. Implications for surface water eutrophication of changes in P retention by soils are discussed.
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    Mechanisms for internal loading of phosphorus in lakes (1998)
    Springer
    Hydrobiologia 373-374 (1998), S. 21-25 
    Details
    ISSN: 1573-5117
    Keywords: internal loading ; phosphorus ; fractionation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lake sediments play an important role in the phosphorus metabolism in lakes. The impact depends on the tendencies to retain and to release phosphorus.The internal loading will often determine the eutrophication status of the lake and the time lag for recovery after reduction of the external loading. Internal loading is most important during the summer. The potential source of phosphorus in the surficial sediments is very large in comparison to the pools in the water column. This means that even if only a very small amount is released, it will have significant impact on the phosphorus concentration in the lake water. The distribution of phosphorus forms in sediments have been investigated since the 1950s. Generally, vertical profiles of sediment phosphorus content, expressed on dry weight basis, show an increasing total content towards the sediment surface. The vertical profile continues up into the water when looking at the particulate matter. A number of environmental factors are important in the mobilisation processes. Most studies indicate that sediment bacteria have a significant role in uptake, storage and release of phosphorus including anaerobic release of iron-bound phosphorus. Several phytoplankton species have resting stages overwintering on the sediment. When growth is induced, they leave their habitat in order to shift their life-form to a pelagic one. In Lake Erken the cyanobacteria Gloeotrichia echinulata has been shown to contribute significantly to the internal loading of phosphorus during the summer.
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    URL: http://dx.doi.org/10.1023/A:1017011420035
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    Seasonal and spatial trends of nitrogen and phosphorus loads to the upper catchment of the river Vilaine (Brittany): relationships with land use (1998)
    Springer
    Hydrobiologia 373-374 (1998), S. 247-258 
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    ISSN: 1573-5117
    Keywords: Nitrogen ; phosphorus ; catchment ; water quality ; river ; discharges
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Influences of urban and agricultural activities on river water quality were analysed on the upper catchment of the River Vilaine (902 km2), France. Agricultural land covered 78% of the study area. Corn, grass and cereals were the main crops. Total Nitrogen (TN) and Total Phosphorus (TP) loads were determined for individual subcatchments (from 10 to 194 km2) during the hydrological year 1994/95. Relationships between water quality and catchment management were studied. Non-point source produced 95% of TN and 90% of TP of the whole river basin. Significant variation in TN and TP occurred, in time and space. The greatest part was discharged in January and February. Annual river exportation rates ranged from 20 to 65 kg TN ha-1 and from 1.15 to 3.05 kg TP ha-1. Reservoirs will held almost 15% of TN and TP loads. Cyanobacteria blooms occurred in summer and autumn, with significant production of organic matter here, and downstream, in the rivers. Greatest TP river retention rate were determined downstream a town of 15000 people, and highest TN loss occurred in the subcatchment with the highest density of cattle and the most important percent of permanent grassland.
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    Eutrophication processes in a shallow, macrophyte-dominated lake – nutrient loading to and flow through Lake Łuknajno (Poland) (1997)
    Springer
    Hydrobiologia 342-343 (1997), S. 387-394 
    Details
    ISSN: 1573-5117
    Keywords: nitrogen ; phosphorus ; drainage waters ; sediments ; sorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lake Łuknajno, a shallow (max. depth 3 m) and relativelylarge(630 ha) water body situated in the Great Masurian Lakessystem(Poland) is strongly affected by its agricultural watershed.Thetotal volume of drainage waters pumped into the lake in 1993amounted 2.84 × 106m3 which is equivalentto65% of the lake volume. In spring and autumn drainage waterswereextremely rich in nitrogen (especially nitrates) and the N:Pratioreached 57 in spring. In summer, drainage waters containedrelatively more phosphorus so the N:P ratio decreased tonearly 10.Nutrient concentrations in lake water followed the changes ininflowing waters. High concentrations of nitrates and ammoniawerenoted in lake water in spring but summer concentrations oftheseions were close to zero. Soluble reactive phosphorus variedbetween10 and 20 µg P l−1 throughout the season. A constantoutflow of nitrogen to the lower Lake Śniardwy was assumedbased ona permanent concentration gradient between waters of these twolakes.Lake Łuknajno is a hard water lake. Co-precipitation ofphosphorus with calcium carbonate is likely to occur though nosignificant P accumulation in bottom sediments was found.Sorptionof phosphorus on sediments as measured under experimentalconditions has minor effects on P cycling. Bottom sedimentscomposed mainly of calcareous gyttja do not accumulate eitherorganic matter or mineral forms of nutrients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017099609373
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    Electronic Resource
    Electronic Resource
    Lecanid rotifers (Rotifera: Monogononta: Lecanidae) from North-Eastern India (1997)
    Springer
    Hydrobiologia 356 (1997), S. 157-163 
    Details
    ISSN: 1573-5117
    Keywords: Lecanidae ; N.E. India ; Tripura ; taxonomy ; distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thirty-five species of the family Lecanidae are examined from Tripura state in North-Eastern India. Of these, Lecane levistyla and L. scutata are interesting cold-water forms; L. batillifer is an Australasian element; L. acanthinula and L. sinuata are Oriental endemics and L. braumi, L. lateralis and L. simonneae are palaeotropical species. The lecanid fauna also includes the pantropical L. thienemanni and L. sola while the remainder are cosmopolitan and tropicopolitan elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003132516951
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