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  • Angiosperms  (62)
  • Saccharomyces cerevisiae  (34)
  • healthy volunteers  (31)
  • Springer  (127)
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  • 1985-1989  (127)
  • 1980-1984
  • 1986  (127)
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  • 1985-1989  (127)
  • 1980-1984
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  • 1
    Electronic Resource
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    Springer
    Current genetics 10 (1986), S. 943-945 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; α-factor ; Protoplasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When Mat a cells are treated with α-factor prior to being protoplasted and fused, the frequency of karyogamy is higher than in unarrested controls.
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  • 2
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    Current genetics 10 (1986), S. 665-670 
    ISSN: 1432-0983
    Keywords: Multiple drug resistance ; Genetic mapping ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the yeast Saccharomyces cerevisiae, two nuclear pleiotropic drug resistance mutations pdr3-1 (former designation muc PR) and pdr3-2 (former designation DRI9/T7) have been selected as resistant to mucidin and as resistant to chloramphenicol plus cycloheximide, respectively. The pdr3 mutations were found not to affect the plasma membrane ATPase activity measured in a crude membrane fraction. Meiotic mapping using strains with standard genetic markers revealed that mutation pdr3-1 is centromere linked on the left arm of chromosome II at a distance of 5.9 ± 3.3 cM from its centromere and 11.6 ± 3.1 cM from the marker pet9. The centromere linked pdr3-2 mutation exhibited also genetic linkage to pet9 with a map distance of 9.8 ± 3.2 cM. These results indicate that pdr3-1 and pdr3-2 are alleles of the same pleiotropic drug resistance locus PDR3 which is involved in the control of the plasma membrane permeability in yeast.
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  • 3
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    Current genetics 10 (1986), S. 657-664 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Amino acid biosynthesis ; General control ; GCD-genes ; GCN-genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutant strains, resistant against the amino acid analogues 5-methyltryptophan, 5-fluorotryptophan and canavanine were isolated, starting with a trp2 leaky auxotrophic strain. Of 10 such strains, only four turned out to be of the “general control derepressed” (gcd) mutant type. Three other isolates were shown to be defective in the general amino acid permease system, while the remaining three strains displayed low spore viability and were not further investigated. Complementation tests amongst the four new gcd-mutant strains, including strain RH558 gcd2-1 isolated earlier, yielded five complementation groups: GCD2, GCD3, GCD4, GCD5, and GCD6. All mutant strains showed a dual phenotype, which was not separable by wild type backcrosses: “constitutive derepression” and “slow growth”. Epistatis of all gcd mutations over gcn1-1, gcn2-1 and gcn3-1 was found with respect to both phenotypes, except for gcd5-1, which was lethal in these combinations. On the other hand gcn4-101 was found to be epistatic over all gcd mutations, but only with respect to the “constitutive derepression” phenotype, and not to “slow growth”; again the combination with gcd5-1 was lethal. Mutation gcd2-1 was mapped on chromosome VII, 50 cM from leu1 and 22 cM from ade6. A new model is discussed, in which GCD-genes are involved in the amino acid uptake into the vacuoles.
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  • 4
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    Current genetics 10 (1986), S. 491-494 
    ISSN: 1432-0983
    Keywords: Protoplast fusion ; Saccharomyces cerevisiae ; Schwanniomyces castellii ; Starch fermentability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Prototrophic hybrids have been obtained by the fusion of various auxotrophic haploid strains of Saccharomyces cerepisiae and Schwanniomyces castellii. The fusion hybrids showed starch fermentability which derived from one of the fusion parents, S. castellii. Surprisingly, these fusion hybrids were found to exhibit excellent sporulation and spore germination. The progenies of these fusion hybrids showed a few aberrant segregations, but mostly normal segregation for auxotrophic genetic markers. They also showed many tetrads with an apparently digenic segregation (2:2, 3:1 and 4:0) for starch fermentation. On the other hand, mating types of segregants of the fusion hybrids were determined by the prototrophic recovery method. Consequently, tetrad types for mating type were mostly 2a:1α:1 non-mater and several asci showed tetrad types of 2a:2 non-mater and 2a:2α. The 60 prototrophic fusion hybrids and its segregants did not secrete α-amylase on the starch agar plate. However, all of the data suggested that fusion hybrid could carry two dominant genes (STAB and STAC) to ferment starch, and that the two genes STAB and STA2 may be identical or allelic as may be the genes STAC and STA3.
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  • 5
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    Current genetics 11 (1986), S. 93-96 
    ISSN: 1432-0983
    Keywords: Uracil permease gene ; Saccharomyces cerevisiae ; Chromosomal mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The gene FUR4, coding for the uracil permease in Saccharomyces cerevisiae, was mapped on chromosome II, at a distance of 7.8 cM from the centromere on the right arm of the chromosome. In a first step, we used the chromosome loss mapping method developed by Falco and Botstein (1983) to determine on which chromosome the gene mapped. After the observation that FUR4 was closely linked to GAL10, one of the three genes forming the gal cluster (Bassel and Mortimer 1971), we could determine precisely the position of the gene on chromosome II.
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  • 6
    ISSN: 1432-0983
    Keywords: Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; DNA ligase ; DNA damage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary UV-irradiation of stationary phase cells of Saccharomyces cerevisiae and Schizosaccharomyces pombe leads to a 9-fold and 90-fold increase in transcript levels from the respective DNA ligase genes CDC9 and CDC17, whereas exponential cells show only 3-fold and 2-fold increases. Induction of CDC9 after MMS treatment and γ-irradiation was also observed by using a CDC9-lacZ translational fusion and assaying for β-galactosidase. Surprisingly, irradiation of S. cerevisiae induces only a 50% increase in DNA ligase itself, probably reflecting the extremely high in vivo stability of the enzyme. The UV-induction of ligase may be part of a “fail-safe” mechanism which, together with the enzyme stability, ensures adequate supplies of this essential enzyme.
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  • 7
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    Current genetics 11 (1986), S. 193-200 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Ty elements ; Transposable elements ; Retroviruses ; tRNA genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have isolated and characterized a Ty element from a yeast cosmid library which exhibits several unsual features: it is flanked by non-homologous delta elements and directly associated with a singular delta element. A tRNA(Glu3) gene and tRNA(Cys) gene are found in conjunction with this element, located in opposite orientation on either end of it. The sequence information now available for several Ty elements has been used in a detailed comparative analysis to determine conserved features among the Ty elements, preferably between class I elements and a class II element. Highly conserved sequence motifs appear to be located at the borders of particular segments that correspond to the putative protein domains of the Tys. Furthermore, we include a comparison of the best-conserved amino acid homologies for these putative proteins of Ty elements, transposable elements from other organisms and several retroviral proviruses to confirm their close structural resemblance.
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  • 8
    ISSN: 1432-0983
    Keywords: Rho°-petites ; Lycorine ; Mitochondrial DNA replication ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper describes the isolation and characterization of mutants affected in the maintenance of the mitochondrial (mt) genome. The rationale of the screening procedure is based on the observation that the alkaloid lycorine inhibits growth of rho −-mutants, whereas rho°-mutants, devoid of mt DNA, are resistant to this drug (Del Giudice et al. 1984). Fourteen temperature sensitive mutants have been isolated that display the following phenotype: -Growth on fermentable medium at 23°C and 35°C (exclusion of general temperature-sensitive mutants). -no growth at 23°C and growth at 35°C on fermentable medium containing lycorine (selection for mutants producing rho°-petites). -growth at 23°C and no growth an 35°C on non-fermentable medium (selection for temperature-dependent loss of respiratory competence). These mutants were termed tmm (for temperature sensitive maintenance of mt genome). Mutant tmm1-1 was analyzed genetically and biochemically. It carries a recessive nuclear mutation which gives rise to 90–95% cytoplasmic petites at the non-permissive temperature. The population of petites consists of more than 95% rho°-petites as shown by their resistance to lycorine, by staining with 4′,6-diamidino-2-phenylindole (DAPI), and by Southern hybridization with mt DNA probes. Wild-type control cultures produced approximately 1% petites with less than 10% rho°-mutants.
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  • 9
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    Current genetics 11 (1986), S. 211-215 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Hyperresistance ; DNA damaging agents ; Genotoxic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In order to study resistance to DNA damaging agents, yeast DNA segments conferring hyperresistance in this organism to such genotoxic agents were selected for among yeast cells transformed by a yeast genome library based on the multi-copy vector plasmid YEp13. Genetic variants hyperresistant to 4-nitroquinohne-N-oxide, formaldehyde, and alkylating agents were isolated and the respective hyperresistance determinants shown to co-segregate with the vector plasmid. Phenotypical characterization indicated different degrees of resistance, few cases of cross-resistance and differing structural stability of the cloned DNA. By transfer to E. coli and subsequent retransformation of yeast a number of plasmids was shown to stably carry the genetic information for hyperresistance.
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  • 10
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    Current genetics 11 (1986), S. 217-225 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Gene cloning ; Invertase genes ; Multicopy vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Six unlinked loci for invertase structural genes are known in the yeast Saccharomyces cerevisiae: SUC1-SUC5 and SUC7. These genes are similar in structure and expression but not identical. Different yeast strains possess none, one or several of these genes. We have isolated the genes SUC1-SUC5, subcloned them into the multicopy vector YEp24 and compared the expression of the five SUC genes in one recipient strain. SUC2 was isolated by transformation of a suc0 strain with a gene pool and complementation to sucrose fermentation. SUC4 was cloned from a minipool of chromosomal fragments which were shown to contain SUC4 by Southern hybridization. SUC1, SUC3 and SUC5 were isolated using the method of plasmid eviction. A plasmid containing regions flanking SUC4 was integrated next to these SUC genes. The plasmid together with the SUC genes were then cut out of the chromosome using an appropriate restriction endonuclease. The length of chromosomal DNA fragments containing the different SUC genes were 4.8 kb for SUC1, 5.2 kb for SUC2, 4.8 kb for SUC3, 12.8 kb for SUC4 and 17.2 kb for SUC5. Fragments containing the complete SUC genes and the sequences controlling their expression were subcloned into YEp24 and transformed into a strain without any active invertase gene. Invertase activity of transformants was measured after growth repressing (8% glucose) and derepressing (2% raffinose) conditions. As expected from results with strains carrying the individual SUC genes in a chromosomal location, the SUC genes were expressed to a different extent.
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  • 11
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Nucleo-mitochondrial interactions ; Mitochondrial status ; Dominant lycorine resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mutants resistant to 200 µg/ml of the alkaloid lycorine (LYC R) in non-fermentable substrate were isolated after nitrosoguanidine mutagenesis. Tetrad analysis and growth of heterozygous (LYC R/lyc s) diploids from two different mutants revealed that a single nuclear and dominant mutation is responsible for the resistant phenotype. In the wild type total protein synthesis is only slightly inhibited, whereas DNA and RNA synthesis is lowered to about 30% of the control. In the lycorine resistant mutants all macromolecular syntheses are unaffected by the drug.
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  • 12
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Cytochrome c ; Regulatory gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The CYP1 gene has previously been identified as coding for a positive trans active factor that activates the expression of CYC1 and CYP3, which are the structural genes for isol- and iso2-cytochrome c. Two phenotypically distinct classes of CYP1 mutations can be obtained indicating that CYC1 and CYP3 are differentially regulated by the product of CYP1. The HAP1 gene codes for a product which has previously been proved to be necessary for the expression of the heme dependent CYC1-UAS1 cis regulatory sequence. In this article, we show by complementation and recombination that CYP1 and HAP1 are the same gene, moreover we identify hap1-1 as an iso2-cytochrome c underproducer mutation of the CYP1 gene.
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  • 13
    ISSN: 1432-0983
    Keywords: agα1 Mutant ; Agglutination ; Gene dose effect ; Mapping ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A recessive agα1 mutation leads to specific defect in sexual agglutinability specifically in α cells of the yeast Saccharomyces cerevisiae. The cryptopleurine resistance gene cryR 1, closely linked to the mating type locus, was used to select α/α strains which emerged from α/α strains by mitotic nonreciprocal recombination, to genetically analyse agα1, since agα1 is expressed only in α mating type. The agα1 gene was found to be linked to the centromere tightly, to met3 at 4.4 cM, and to ilv3 at 12 cM on chromosome X. Sexual agglutinability of α cells was shown to be dependent on the dose of the AGα1 gene, using α/α isogenic strains carrying AGα1/AGα1, AGα1/agα1 or agα1/agα1. The sst2-1 mutation did not suppress the agα1 mutation. Based on these results, function of the AGα1 gene is discussed.
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  • 14
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    European journal of clinical pharmacology 31 (1986), S. 285-290 
    ISSN: 1432-1041
    Keywords: imipramine ; ranitidine ; cimetidine ; pharmacokinetics ; metabolism ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetic characteristics of imipramine were studied after a single, oral, 100 mg dose was taken by 12 healthy male subjects following 3 days of pretreatment with placebo, cimetidine (300 mg every 6 h), and ranitidine (150 mg every 12 h) in a randomized, double blind, crossover trial. After each imipramine dose plasma samples were collected for 72 h and assayed for imipramine, desipramine, 2-hydroxyimipramine and 2-hydroxydesipramine by HPLC. Cimetidine preadministration statistically prolonged imipramine t1/2 compared to ranitidine (22.7 vs. 13.0 h) or placebo (10.8 h). Mean imipramine area under the curve (AUC) following cimetidine pretreatment was more than double that following placebo (2.633 vs. 0.966 µg·h·ml−1) or ranitidine (1.14 µg·h·ml−1) pretreatment. Imipramine apparent oral clearance was reduced in all 12 subjects after cimetidine. Compared to ranitidine or placebo, cimetidine pretreatment was associated with an increased imipramine/desipramine AUC ratio, suggesting cimetidine-induced impairment of demethylation of imipramine. Ranitidine was not observed to alter imipramine pharmacokinetics.
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  • 15
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    European journal of clinical pharmacology 31 (1986), S. 299-302 
    ISSN: 1432-1041
    Keywords: femoxetine ; cimetidine ; pharmacokinetics ; drug interaction ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The possibility of a pharmacokinetic interaction between femoxetine and cimetidine has been evaluated in 8 healthy volunteers. Two volunteers received single doses of femoxetine, and 6 were given multiple doses of femoxetine for 7 days with and without concurrent cimetidine. No influence of cimetidine was observed on the kinetics of single doses of femoxetine, but after multiple doses the plasma concentration of femoxetine was significantly increased. Similarly, the AUC at steady state tended to be increased, but not to a significant extent. Concurrent cimetidine did not cause a reduction in the AUC of the active desmethyl metabolite. It is recommended that femoxetine is given in reduced doses (e.g. 400 mg) when administered with cimetidine.
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  • 16
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    European journal of clinical pharmacology 30 (1986), S. 171-175 
    ISSN: 1432-1041
    Keywords: caffeine ; verapamil ; coffee ; blood pressure ; slow calcium-channel blockade ; drug interaction ; healthy volunteers ; plasma catecholamines ; plasma renin activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary An increase in blood pressure after coffee and caffeine has recently been reported. A possible pharmacological mechanism for this pressor response is a rise in the intracellular calcium concentration, caused by an increase in calcium influx due to a direct effect of caffeine. Accordingly, the cardiovascular effects of drinking coffee after placebo and verapamil 3 × 80 mg in 1 day in 10 normotensive volunteers have been examined in a single-blind study. After placebo, coffee led to an increase in blood pressure (7/14 mm Hg), and a fall in heart rate (−7 beats/min); forearm blood flow did not change. Plasma epinephrine rose (257%), plasma norepinephrine did not change and the plasma renin activity fell significantly. The haemodynamic and humoral changes after coffee were not altered by pretreatment with verapamil. It is concluded that increased transmembrane calcium influx after caffeine does not appear to be an important pharmacological mechanism for the circulatory effects of coffee.
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  • 17
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    European journal of clinical pharmacology 31 (1986), S. 177-182 
    ISSN: 1432-1041
    Keywords: glibenclamide ; bioavailability ; pharmacokinetics ; dissolution ; hypoglycaemia ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A study has been carried out investigating four different marketed oral preparations of glibenclamide, correlating the effectiveness of the drug in these preparations in lowering plasma glucose concentrations with (i) the in vitro dissolution of the drug, measured by the British Pharmacopoeal and Desaga methods, and (ii) the in vivo bioavailability, assessed in 12 healthy human volunteers. The two dissolution methods yielded different rank orders of ease of dissolution of the drug from the various preparations; the findings of neither dissolution method correlated adequately with the results of the in vivo bioavailability studies, which correctly predicted the abilities of the preparations to reduce plasma glucose concentrations. Relative to an oral glibenclamide solution the bioavailabilities of the drug from three tablet preparations were 0.69, 0.49 and 0.24. The mean elimination half-life of the drug was 1.5 h and assuming complete bioavailability of the drug from oral solution the mean systemic clearance was 0.095 l kg−1h−1, and the mean apparent volume of distribution was 0.20 l kg−1. It is concluded that it may be unsafe to use in vitro dissolution data as a basis for assessing the bioequivalences of different glibenclamide preparations intended for oral use.
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  • 18
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    European journal of clinical pharmacology 30 (1986), S. 177-182 
    ISSN: 1432-1041
    Keywords: perindopril ; blood pressure ; heart rate ; parasympathetic ; sympathetic ; converting enzyme inhibitor ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of the angiotensin converting enzyme inhibitor, perindopril, on autonomic function was assessed in a double blind, placebo controlled, crossover study in 10 normotensive males. Eight milligram of perindopril given orally lowered blood pressure without a change in heart rate. Perindopril enhanced the vagally mediated heart rate variation with deep breathing. There was no impairment of the responses to either bicycle exercise at 175 W for 5 min or isometric handgrip. The pressor response to cold was not changed and the response to the Valsalva manoeuvre was unaltered. These results suggest that the absence of tachycardia after perindopril may be in part related, as has been reported with other converting enzyme inhibitors, to enhanced cardiac parasympathetic tone. Vagomimetic action may be a property of converting enzyme inhibitors in general.
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  • 19
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    European journal of clinical pharmacology 30 (1986), S. 269-271 
    ISSN: 1432-1041
    Keywords: gastric antisecretory agent ; 40 749 RP ; long acting drug ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary 40 749 RP, a pyridyl-2-tetrahydrothiophene derivative is known to be a potent gastric antisecretory agent in animals and man. In 27 healthy volunteers in four double-blind cross-over studies, this activity has been examined against basal and pentagastrin stimulated gastric acid secretion. The effect of a single oral dose of 2 mg/kg was still present after 12, 24 and 48 h. The effect of 1 mg/kg was definitely increased after treatment for 7 days as compared to a single dose of 1 mg/kg.
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  • 20
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    European journal of clinical pharmacology 30 (1986), S. 323-329 
    ISSN: 1432-1041
    Keywords: methylprednisolone ; prednisolone ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The disposition and plasma binding of methylprednisolone were examined in seven normal volunteers following the administration of 5, 20 and 40 mg of intravenous methylprednisolone sodium succinate. Methylprednisolone exhibits linear plasma protein binding averaging 77%. The mean plasma methylprednisolone clearance of 337 ml·h−1. kg−1 was independent of dose. The steroid appears to moderately distribute into tissue spaces with a mean volume of distribution of 1.41·kg−1. Methylprednisolone disposition parameters were compared with the non-transcortin bound parameters for prednisolone. The prednisolone plasma clearance based on the transcortin free-drug is similar to methylprednisolone total plasma clearance. However, the corrected volume of distribution of prednisolone is only one-half that of methylprednisolone. The disposition rate of these two steroids is thus similar, in spite of their metabolic control by different enzymatic pathways and major influence of saturable transcortin binding on prednisolone elimination.
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  • 21
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    European journal of clinical pharmacology 30 (1986), S. 355-357 
    ISSN: 1432-1041
    Keywords: substance P ; mucociliary activity ; inflamatory reactions ; nose ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Substance P (SP), a potent inflammatory agent, has been found in sensory nerve fibres in the nasal mucosa in several experimental animals as well as in man. It may participate in the inflammatory response as part of the mucosal defence against foreign materials. In experimental animals SP has been found to increase mucociliary in airway mucosa. The present study was performed in order to find out the relationship between topically applied SP and nasal mucociliary function in humans. Thirteen healthy volunteers were challenged with 65 µg SP or placebo in a randomized cross over fashion and mucociliary transport time was determined each time using the saccharine dye test. The dose of SP was chosen after an open dose-response study. No statistically significant change in the mucociliary transport time was found after challenge with SP as compared to placebo. The possible reasons for this are discussed.
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  • 22
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    European journal of clinical pharmacology 30 (1986), S. 581-584 
    ISSN: 1432-1041
    Keywords: dihydroergotamine ; venoconstriction ; nasal spray ; healthy volunteers ; i.m. administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A parenteral formulation of dihydroergotamine (DHE) is the only galenical form now available for the treatment of acute attacks of migraine in which a rapid onset of action is required. A recently developed nasal spray of DHE has been compared with intramuscular DHE for its venoconstrictor activity. In a randomised double-blind, cross-over trial, 9 healthy male volunteers received a single dose of DHE 1 mg intranasally, DHE 0.5 mg i.m. or placebo (intranasally and i.m.) on three different occasions, with an interval of at least 1 week between doses. Both active treatments, but not placebo, produced marked venoconstriction as shown by reduced compliance of superficial hand veins. The effect persisted for more than 8 h. The maximum venoconstrictor effect of 1 mg DHE intransally was 40±12% (mean ± SEM) and after 0.5 mg i.m. it was 52±15%. The time course of the venoconstrictor effect was similar after both routes of administration. Blood pressure and heart rate changes in these normotensive subjects were almost identical after dihydroergotamine and placebo. The results suggest that the nasal spray could be used as an alternative to parenteral DHE, permitting self-administration of the drug for the treatment of acute attacks of migraine.
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  • 23
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    European journal of clinical pharmacology 30 (1986), S. 741-744 
    ISSN: 1432-1041
    Keywords: cimetidine ; subchronic administration ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of cimetidine on its own pharmacokinetics after subchronic administration was assessed in 8 healthy volunteers, aged 26–29 years. On control Day 1, each subject received cimetidine 300 mg i.v., and serum and urine samples were obtained. Each subject was initiated on cimetidine 600 mg b.i.d. orally for 2 weeks. There were 3 further study days repeated after 1 and 2 weeks of cimetidine dosing and 1 week after stopping cimetidine. There was no significant difference in the mean total body clearance of cimetidine among the 4 study days. Mean elimination t1/2β and Vβ were similarly unchanged. However mean renal clearance (CLR) and fe were significantly increased following 2 weeks of drug dosing (CLR 5.41 ml·min−1 kg−1; fe 0.61) compared to control (CLR 4.00 ml·min−1·kg−1; fe 0.48). Although the non renal clearance was reduced from control values of 4.29 to 3.51 ml·min−1·kg−1 following 2 weeks of dosing the difference was not significant. Dosage adjustment of cimetidine appears unnecessary after short-term dosing in the presence of normal renal function.
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  • 24
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    European journal of clinical pharmacology 31 (1986), S. 419-422 
    ISSN: 1432-1041
    Keywords: bupranolol ; transdermal delivery system ; beta1- and beta2-adrenoceptor binding ; steady-state concentration ; healthy volunteers ; plasma concentrations ; beta-adrenoceptor antagonism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Bupranolol is a non-selective beta-adrenoceptor antagonist with a Ki-value of 6–15 nmol/l (equivalent to 1.5–4 ng/ml in plasma) at beta1- (rat salivary gland) and beta2-adrenoceptors (rat reticulocytes) in receptor binding studies with3H-CGP 12177 in the presence of human plasma. After oral administration of 200 mg bupranolol to healthy volunteers, the maximal plasma concentration was observed within 1.2 h but it only reached a level close to the Ki-value. Elimination from plasma was rapid (t1/2=2.0 h). Administration of 30 mg bupranolol in a transdermal delivery system (TTS) every 24 h to 6 healthy volunteers for 72 h yielded steady state plasma concentrations 4- to 5-times above the Ki-value as shown by in vitro inhibition of beta-adrenoceptor binding by plasma samples. The pharmacodynamic effect, measured as the reduction in exercise tachycardia, showed a stable inhibitory effect; antagonism of a bolus injection of isoprenaline indicated a 10- to 15-fold right shift of the dose-response curve during the observation period of 72 h. It is concluded that steady-state plasma concentrations and effect of the elsewise rapidly eliminated beta-blocker bupranolol can be achieved by a transdermal delivery system applied each day.
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  • 25
    ISSN: 1432-1041
    Keywords: metronidazole ; metabolism ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of dose and route of administration on the kinetics of metronidazole and its major metabolites has been investigated in 8 healthy volunteers given 0.5 and 2.0 g i.v. and p.o. Metronidazole elimination kinetics from plasma could be described by an open two-compartment model. The systemic oral bioavailability of both doses was approximately 1. The total systemic clearance of the intravenous 2.0 g dose was 9% lower than that of the 0.5 g dose (p〈0.05). There were no significant dose-related differences in volume or rate of distribution. The elimination half-life was similar after the four treatments with metronidazole. The major elimination pathways, renal excretion and hepatic oxidation and glucuronidation, accounted for more than 2/3 of the total systemic clearance. Clearance both by hepatic oxidative metabolism and renal excretion was significantly lower after 2.0 than after 0.5 g i.v., whereas there was no significant difference after the oral doses. The results indicate that a high therapeutic dose of metronidazole may be eliminated at a reduced rate, but this is probably not of clinical importance. No single saturable elimination pathway was identified.
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  • 26
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    European journal of clinical pharmacology 31 (1986), S. 239-242 
    ISSN: 1432-1041
    Keywords: piroximone ; cardiotonic drug ; pharmacokinetics ; bioavailability ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Six healthy, male subjects received single intravenous and oral doses of piroximone. Plasma piroximone concentrations were assayed up to 8 h after each dose by HPLC. Urinary excretion of the parent compound was also determined. Following the oral dose, piroximone reached peak plasma concentrations within 30 to 90 min. The t1/2 of the terminal decay phase was 2.8 h, the mean apparent volume of distribution was 2.5 l/kg, and the mean total body clearance was 755 ml/min. Mean urinary recovery of parent drug within 24 h was 50% after the intravenous dose and 41% after the oral dose. Renal clearance accounted for approximately 50% of total body clearance. Oral bioavailability, estimated from AUC or urinary recovery, was 80%.
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  • 27
    ISSN: 1432-1041
    Keywords: renin ; aldosterone ; dopamine ; natriuretic hormone ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The acute natriuretic effect of human atrial natriuretic peptide (ANP) has been well described in man. We have now studied possible hormonal mediators of this effect. We studied six healthy volunteers on two occasions when they received either an infusion of ANP of 1.5 pmol·kg−1·min−1 for 30 min followed by 15 pmol·kg−1·min−1 for a further 30 min, or matching vehicle infusions in a randomized single-blind fashion. On the placebo day, plasma renin activity (PRA) rose from 1.26±0.08 to 1.57±0.14 ng A1·ml−1·h−1, while on the ANP study day PRA fell from 1.45±0.15 to 1.28±0.05 ng A1·ml−1·h−1 (p〈0.01). No significant changes were found in plasma aldosterone concentrations or in urinary dopamine excretion. These results provide evidence that ANP suppresses renin release in man.
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  • 28
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    European journal of clinical pharmacology 31 (1986), S. 371-374 
    ISSN: 1432-1041
    Keywords: oxaprozin ; drug interaction ; acetaminophen ; cimetidine ; ranitidine ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Twelve healthy male volunteers participated in a single-dose four-way crossover study to evaluate potential drug interactions with oxaprozin, a nonsteroidal antiinflammatory agent of the propionic class. The four modes of administration were:a. oxaprozin, 1200 mg alone;b. oxaprozin during concurrent acetaminophen, 500 mg 4 times daily;c. oxaprozin with cimetidine, 300 mg 4 times daily;d. oxaprozin with ranitidine, 150 mg every 12 hours. Acetaminophen, cimetidine, or ranitidine were begun 24 hours prior to oxaprozin dosage and continued for the 10-day duration of each trial. No significant differences existed among the four treatment conditions in peak plasma oxaprozin concentration (86 µg/ml), volume of distribution (0.23 l/kg), time of peak concentration (3.7 h after dosage), or elimination half-life (54 h). Oxaprozin oral clearance was significantly lower (by 20%) during both the cimetidine and ranitidine trials versus control (0.047 vs 0.047 vs 0.059 ml/min/kg), but clearance during acetaminophen was not significantly different from control. Thus acetaminophen, cimetidine or ranitidine has only a small influence on the pharmacokinetics of a single oral dose of oxaprozin. The reduction in oxaprozin clearance due to cimetidine or ranitidine is statistically significant but small in magnitude.
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  • 29
    ISSN: 1432-1041
    Keywords: thromboxane A2-receptor blocker ; BM 13.177 ; single dose pharmacokinetics ; platelet aggregation ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and pharmacodynamic effect on platelet activation of a single 800 mg oral dose of BM 13.177 have been investigated in 8 male volunteers. BM 13.177 disappeared from plasma with a terminal elimination half-life of 0.85 h. 52% of the dose was excreted unchanged in urine. Assuming complete absorption, total clearance was calculated to be 741.3 ml/min and renal celearance to range from 310.4 to 396.9 ml/min. The pharmacodynamic studies were performed ex vivo/in vitro in platelets stimulated either with methyl mercury chloride or with U 46619. Methyl mercury chloride is a platelet activator that requires TXA2 formation from endogenous arachidonic acid, whereas U 46619 is a stable PGH2 analogue and thromboxane mimetic at the platelet TXA2/PGH2 receptor. A close correlation between the plasma concentration-time profile of BM 13.177 and inhibition of platelet shape change or aggregation was demonstrated.
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  • 30
    ISSN: 1432-1041
    Keywords: bufuralol ; hepatic oxidation ; debrisoquine/sparteine phenotype ; stereo- and regioselectivity ; metabolites ; healthy volunteers ; drug metabolism ; polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of the debrisoquine/sparteine-type of oxidation polymorphism on plasma bufuralol concentration and the pattern of urine metabolites was studied in extensive and poor metabolizer subjects. (+)- and (−)-bufuralol, and (+)- and (−)-OH-bufuralol in plasma were determined by enantioselective HPLC, and urinary bufuralol and its metabolites were assayed by gas chromatography-mass spectrometry. Three hours after administration of racemic bufuralol the plasma (−)/(+) isomeric ratio for unchanged bufuralol was 1.84 in extensive metabolizers, indicating preferential clearance of the (+)-isomer through aliphatic 1′-hydroxylation and glucuroconjugation, while the (−)-isomer was mainly eliminated by aromatic 4-hydroxylation. Poor metabolizers were characterized by impaired 1′- and 4-hydroxylation, with almost total abolition of the stereoselectivity of these reactions. The data strongly suggest that both 1′- and 4-hydroxylation are catalyzed by the same enzyme. These in vivo observations are in agreement with recent in vitro data obtained in human liver microsomes from phenotyped patients and support the concept of deficiency of a highly stereoselective cytochrome P-450 isozyme as the cause of this polymorphism.
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  • 31
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    European journal of clinical pharmacology 31 (1986), S. 339-342 
    ISSN: 1432-1041
    Keywords: ketanserin ; ketanserin-ol ; pharmacokinetics ; reduction-oxidation equilibrium ; healthy volunteers ; adverse effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The metabolic reduction-oxidation equilibrium between ketanserin and ketanserin-ol was studied after oral dosing of both substances to two healthy volunteers. Comparison of plasma Cmax and AUCs indicated that the equilibrium was shifted towards ketanserin-ol. There is evidence that ketanserin-ol elimination is the slowest step dictating the terminal half-life of ketanserin.
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  • 32
    ISSN: 1432-1041
    Keywords: citalopram ; antidepressant drug ; pharmacodynamics ; adverse effects ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Citalopram, a selective 5-HT uptake inhibitor with antidepressant properties, was assessed in three studies in 12 healthy subjects using a battery of EEG, psychological, subjective and symptomatic measures. Study A involved the administration of citalopram, 20 mg and 40 mg, amitriptyline 50 mg and placebo in single dose using a balanced cross-over design. The test battery was applied before, and 1 and 3 h after each drug. Citalopram decreased slow-wave EEG activity whereas amitriptyline increased power in most EEG wavebands. Citalopram increased tapping rate and symbol copying whereas amitriptyline impaired these and other psychomotor tasks. Subjectively, amitriptyline was much more sedative than citalopram and produced more complaints of dry mouth. Study B comprised the administration of citalopram in the usual clinical dose of 40 mg, amitriptyline in the low clinical dose of 75 mg and placebo, each given for 9 nights using a balanced cross-over design. The test battery was applied on the first morning (pre-drug) and on the morning after the last nightly dose. None of the physiological tests showed any drug effects. Subjectively, citalopram was associated with feelings of shaking, nausea, loss of appetite and physical tiredness; amitriptyline produced feelings of shaking, nausea, loss of appetite, dryness of mouth, irritability, dizziness and indigestion; in general, amitriptyline effects were more marked than those of citalopram. Plasma samples were taken on the last day and plasma concentrations of both drugs and their metabolites were found to be in the expected range for the regimens used. In the third study (C), 12 healthy subjects took similar courses of citalopram, amitriptyline and placebo. On the morning of the 8th day, a test dose of ethanol was given. The battery of tests was given predrug, on Days 4/5 and on Day 8, before and 1 and 3 h after the ethanol. Amitriptyline increased the 7.5–13.5 Hz waveband. Amitriptyline impaired critical flicker fusion frequency, tapping, DSST and reaction time; citalopram affected DSST and immediate memory recall. The subjective and symptomatic effects of the drugs were similar to those in Study B. Plasma concentrations of citalopram, amitriptyline and their desmethylated metabolites were in the expected range for the regimens used. Ethanol had the expected effects, impairing performance and producing sedation. No evidence for potentiation of ethanol and drug effects were found, most interactions being additive, or even with some symptoms subtractive. It is concluded that in clinical use citalopram should have little or no effect on cognitive and psychomotor performance, produce minimal sedation but some nausea, loss of appetite and insomnia. Interactions with ethanol should be unremarkable.
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  • 33
    ISSN: 1432-1041
    Keywords: diclofenac sodium ; triamcinolone acetate ; pharmacokinetics ; drug interactions ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Seventy-five mg diclofenac sodium were given intramuscularly to 15 subjects alone and in combination with 40 mg triamicinolone acetate. Plasma levels of diclofenac were measured and pharmacokinetic parameters were calculated. The results indicate no statistically significant differences for most of the parameters. The maximum plasma concentrations (Cpmax) was increased by about 20% in combination with the glucocorticoid, whereas terminal elimination rate did not change significantly.
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  • 34
    ISSN: 1432-1041
    Keywords: tiapamil ; desmethyltiapamil ; pharmacokinetics ; cardiovascular effects ; cirrhotic patients ; plasma protein binding ; impaired hepatic elimination ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Tiapamil 70 mg was administered i.v. to 8 healthy male volunteers and 8 patients (7 males, 1 female) with biopsy proven hepatic cirrhosis. Two of the patients also received 600 mg p.o. Serial plasma and urine samples were collected and the parent drug in plasma and urine and desmethyl-tiapamil in urine were assayed by a specific HPLC method. The plasma and urine data for the parent drug after i.v. and p.o. dosing were simultaneously fitted to linear p.o. and i.v. two compartment models with exit from and input into the central compartment. Absorption was assumed to be a first order process. In the volunteers the mean pharmacokinetic parameters were: 101 l for the steady-state volume of distribution, 750 ml·min−1 for nonrenal clearance, 195 ml·min−1 for renal clearance and 1.7 h for the half-life of the terminal disposition phase. The urinary recoveries of the parent drug and desmethyltiapamil averaged 21.4 and 0.8% of the dose, respectively. In the patients the steady-state volume of distribution, the amount of unchanged drug in urine and the half-life of the terminal disposition phase were significantly increased (171 l, 29.0% of the dose, 3.5 h, respectively). Decreased plasma protein binding in the patients accounted for the larger steady-state volume of distribution. The nonrenal clearance of 519 ml·min−1, tended to be smaller in the patients than in the volunteers. Together with the increased urinary recovery of tiapamil in the patients this indicates a moderately impaired elimination capacity in the cirrhotics. The renal clearance was similar in the patients (213 ml·min−1) and the volunteers. The absolute oral bioavailability of tiapamil was 55 and 49% in 2 patients. No effects of tiapamil on heart rate or supine blood pressure were detected, either in volunteers or in patients. Negative dromotropic effects were found in 2 volunteers and 2 patients after i.v. dosing.
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  • 35
    ISSN: 1432-1041
    Keywords: enprofylline ; theophylline ; bronchial reactivity ; histamine inhalation test ; healthy volunteers ; pharmacokinetics ; bronchodilatation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In a double blind, placebo controlled, crossover study the pharmacokinetics and acute effects of enprofylline and theophylline on airway reactivity during histamine challenge were investigated in 10 healthy volunteers. The pharmacokinetic parameters of enprofylline were (mean): elimination half-life 1.9 h, total body clearance 191.1 ml · kg−1 · h−1, volume of distribution 0.48 l · kg−1, and protein binding 49%. Bronchial reactivity in the histamine inhalation test was expressed as the concentration causing a 20% fall in FEV1.0 (PC20). Mean PC20 values were lowest after placebo and highest after theophylline with the enprofylline values in between. Only the difference in PC20 Safter placebo and theophylline was statistically significant (p〈0.05). At the time of determination of the PC20, the serum concentration of enprofylline was between 16.5 and 11.8 µmol/l, and that of theophylline was between 78.3 and 61.1 µmol/l. Adverse actions of enprofylline were nausea (3/10) and cardiovascular reactions (2/10), whereas theophylline mainly caused restlessness (3/10) and tremor (2/10). Thus enprofylline, in one-fifth of the serum concentration of theophylline cannot be regarded as equipotent in terms of bronchoprotection.
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  • 36
    ISSN: 1432-1041
    Keywords: nitrendipine ; digoxin ; plasma levels ; interaction ; systolic time intervals ; adverse effects ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of two different doses of nitrendipine on plasma digoxin levels, urinary recovery and systolic time intervals was investigated in 8 healthy volunteers. Following a loading dose, digoxin 0.25 mg b.d. p.o. was given alone for 2 weeks. Then 0.25 mg digoxin b.d. was administered for two 1-week periods combined with nitrendipine 10 mg or 20 mg once daily. The study was completed with another digoxin monotherapy phase lasting 7 days. Nitrendipine 20 mg daily led to a significant increase in plasma digoxin levels and in its area under the plasma concentration-time curve AUC (0–12) compared to digoxin monotherapy. The AUC (0–12) was 9.7 ng ml−1h when digoxin alone was given and 11.2 ng ml−1h on co-administration of the calcium antagonist. Urinary recovery and renal clearance of digoxin were slightly but not significantly increased by nitrendipine. Nitrendipine 10 mg once daily caused a small, insignificant tendency to elevate the plasma digoxin level. Nitrendipine co-administration (10 and 20 mg once daily) did not significantly alter systolic time intervals, as non-invasively measured haemodynamic parameters, compared to digoxin treatment alone. Thus, nitrendipine 20 mg daily caused a significant increase in plasma digoxin concentrations and in its AUC, which would rarely be of clinical relevance.
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  • 37
    ISSN: 1432-1041
    Keywords: Diltiazem ; slow-release tablet ; pharmacokinetics ; atrioventricular conduction ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics and effect of a slow-release and a conventional diltiazem tablet on atrioventricular conduction were compared in a randomized cross-over study after a single dose and at steady state in 12 healthy volunteers. The time to peak concentration was significantly delayed after the slow-release as compared to the conventional tablet, both after a single dose (2.7 vs. 0.9 h) and at steady-state (1.9 vs. 0.9 h). The peak concentration was also significantly reduced. There was no marked loss in bioavailability with the slow-release formulation. The maximal fluctuations in serum diltiazem at steady-state for the slow-release tablet were markedly less than after the conventional tablet (62 vs 87%). The PQ-interval was longer after the conventional tablet as compared to the slow-release tablet (both in doses of 120 mg) after a single dose (187 vs 163 ms) and at steady-state (197 vs 174 ms). The maximal prolongation was seen 1 h after intake of the drug. Heart rate was decreased only by 6–9 beats/min, irrespective of the dose. Slow-release diltiazem appears to have many advantages over a conventional tablet.
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  • 38
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    European journal of clinical pharmacology 29 (1986), S. 679-683 
    ISSN: 1432-1041
    Keywords: cardioselectivity ; beta-adrenoceptor blockers ; diacetolol ; acebutolol ; metoprolol ; propranolol ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary 1. The beta-adrenergic selectivity of diacetolol, the major metabolite of acebutolol, has been compared with that of acebutolol, metoprolol and propranolol in 11 normal subjects. 2. Bronchial and cardiac beta-adrenoceptor blockade were assessed on separate occasions after diacetolol 600 mg, acebutolol 400 mg, metoprolol 200 mg, propranolol 80 mg and placebo. 3. Bronchial beta-adrenoceptor blockade was assessed as the displacement of the bronchodilator dose response curve to inhaled isoprenaline after each beta blocking drug compared to placebo and expressed as the dose ratio. Bronchodilatation was measured as change in specific airway conductance (sGaw) in the body plethysmograph. Cardiac beta-adrenoceptor blockade was assessed as the percentage reduction in exercise heart rate during the 5th minute of exercise at 70% of the subject's maximum work rate. 4. There was a significant reduction in exercise heart rate with all 4 beta-blocking drugs when compared with placebo, 22% for diacetolol, 24% for acebutolol, 25% for propranolol and 28% for metoprolol. The reduction with metoprolol was significantly greater than the reduction with the other three beta-adrenoceptor antagonists. 5. Mean dose ratios for the airway isoprenaline dose response curves after each of the 4 beta-blocking drugs were 2.4 for diacetolol, 2.7 for metoprolol, 8 for acebutolol and 72 for propranolol. The difference between diacetolol and metoprolol was not significant. 6. Thus diacetolol appears to be more cardioselective than acebutolol and both are more cardioselective than propranolol in man. Metoprolol is probably more cardioselective than diacetolol though interpretation of the differences in exercise heart rate is complicated by the fact that diacetolol has some intrinsic sympathomimetic activity.
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  • 39
    ISSN: 1432-1041
    Keywords: phenobarbital ; propylhexedrine salt ; barbexaclone ; bioavailability ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The kinetics of phenobarbital (PB) was compared after oral administration of equivalent doses of the drug as the acid or the propylhexedrine salt (barbexaclone) to 7 normal volunteers. The absorption and elimination parameters were very similar. It was concluded that propylhexedrine did not affect the serum kinetics of PB given as barbexaclone.
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  • 40
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    European journal of clinical pharmacology 30 (1986), S. 57-60 
    ISSN: 1432-1041
    Keywords: nifedipine ; pharmacokinetics ; oral contraceptives ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma concentrations of Nifedipine were measured following single oral doses of Nifedipine Slow Release (Adalat Retard) on three separate occasions to young, healthy volunteers of both sexes. Intra- and inter-subject variability were assessed by comparing the pharmacokinetic parameters, AUC, Cmax and T50%AUC. Interindividual variability was less than that observed in other studies with the betablockers, metoprolol and propranolol and there was no evidence of differences between the sexes.
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  • 41
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    European journal of clinical pharmacology 30 (1986), S. 121-123 
    ISSN: 1432-1041
    Keywords: dezocine ; opioid analgesics ; pharmacokinetics ; healthy volunteers ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of intravenous (IV) dezocine, and bioavailability of intramuscular (IM) and subcutaneous (SQ) dezocine, were evaluated in healthy male volunteers. Elimination half-life following 5, 10, and 20 mg IV doses averaged 2.6–2.8 h, and was independent of dose. Clearance decreased slightly, although significantly, with dose. After Deltoid IM injection, dezocine was rapidly absorbed (peak level: 0.6 h after dose), with bioavailability 97%. Thus dezocine has extensive distribution, high clearance and short half-life over a range of IV doses. It is rapidly and completely absorbed following IM or SQ administration.
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  • 42
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    European journal of clinical pharmacology 31 (1986), S. 165-168 
    ISSN: 1432-1041
    Keywords: bromerguride ; dopamine antagonist ; pharmacokinetics ; pharmacodynamics ; prolactin level ; side-effects ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma levels and urinary excretion of the dopamine antagonist, bromerguride, were measured by radioimmunoassay in healthy male volunteers given 50 µg i.v. and oral doses of 1 and 2 mg. Plasma prolactin was also measured by radioimmunoassay. Following i.v. injection, the concentration of bromerguride declined biphasically, with half-lives of 7 min and 1.2h. The total clearance was 32 ml·min−1·kg−1 and the apparent volume of distribution was 3.6 l/kg. The bioavailability of oral bromerguride was 29% after 1 mg and 25% after 2 mg. The drug was almost totally metabolized and less than 0.05% of the dose was excreted in urine in 24 h after oral administration. Plasma prolactin levels were increased in a dose-dependent manner for about 8 h. Side-effects were minimal, mainly being tiredness and headache in some of the volunteers.
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  • 43
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    European journal of clinical pharmacology 29 (1986), S. 685-689 
    ISSN: 1432-1041
    Keywords: digoxin ; food ingestion ; ECG ; healthy volunteers ; haemodynamic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effects of the ingestion of food and digoxin on the cardiovascular system alone and in combination have been observed in eight healthy subjects. A positive inotropic response was seen following food (2.5 MJ) and intravenous digoxin (0.01 mg/kg) with significant decreases in QS2Index (QS2I) pre-ejection period (PEP) and PEP/LVET (LVET — left ventricular ejection time). These responses were potentiated when food and digoxin were combined. Opposing effects of food and digoxin on % diastole (%D) and diastolic time were observed, food decreasing %D and DT while digoxin increased these variables. Both food and digoxin decreased T-wave amplitude, and digoxin alone or in combination with food decreased QTc. The positive inotropic effect of a 2.5 MJ mixed meal and a loading dose of digoxin in healthy subjects are of similar degree, different mechanism, and are potentiated in combination.
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  • 44
    ISSN: 1432-1041
    Keywords: idazoxan ; pharmacokinetics ; alpha 2-adrenoceptor antagonist ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A high performance liquid chromatographic method was developed for the quantitative determination of idazoxan in plasma. The assay was used to study the disposition of the drug after intravenous infusion and oral administration to five normal subjects. After i.v. administration the kinetics could be described by a two compartment model with a mean elimination half life of 4.20 h. The mean calculated volume of distribution during the elimination phase was 3.20 l/kg−1 and the mean plasma clearance was 824 ml min−1. After oral administration a lag period before onset of absorption was observed in all five volunteers, the plasma levels declining monoexponentially from the peak concentration with a mean elimination half life of 5.58 h. The absolute availability varied between 26% and 41% with a mean value of 34%. Invitro measurements produced a blood/plasma ratio of 1.3 for idazoxan.
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  • 45
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    Archives of microbiology 145 (1986), S. 27-31 
    ISSN: 1432-072X
    Keywords: Nitrite ; Sulfite ; Saccharomyces cerevisiae ; ATP ; Energy metabolism ; Inorganic phosphate ; Glyceraldehyde-3-phosphate dehydrogenase ; Glucose-6-phosphate dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract After addition of 5 mM sulfite or nitrite to glucose-metabolizing cells of Saccharomyces cerevisiae a rapid decrease of the ATP content and an inversely proportional increase in the level of inorganic phosphate was observed. The concentration of ADP shows only small and transient changes. Cells of the yeast mutant pet 936, lacking mitochondrial F1ATPase, after addition of 5 mM sulfite or nitrite exhibit changes in ATP, ADP and inorganic phosphate very similar to those observed in wild type cells. They key enzyme of glucose degradation, glyceraldehyde-3-phosphate dehydrogenase was previously shown to be the most sulfiteor nitrite-sensitive enzyme of the glycolytic pathway. This enzyme shows the same sensitivity to sulfite or nitrite in cells of the mutant pet 936 as in wild type cells. It is concluded that the effects of sulfite or nitrite on ATP, ADP and inorganic phosphate are the result of inhibition of glyceraldehyde-3-phosphate dehydrogenase and not of inhibition of phosphorylation processes in the mitochondria. Levels of GTP, UTP and CTP show parallel changes to ATP. This is explained by the presence of very active nucleoside monophosphate kinases which cause a rapid exchange between the nucleoside phosphates. The effects of the sudden inhibition of glucose degradation by sulfite or nitrite on levels of ATP, ADP and inorganic phosphate are discussed in terms of the theory of Lynen (1942) on compensating phosphorylation and dephosphorylation in steady state glucose metabolizing yeast.
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  • 46
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    Archives of microbiology 145 (1986), S. 104-106 
    ISSN: 1432-072X
    Keywords: Saccharomyces cerevisiae ; α Factor ; Trifluoperazine ; Chlorpromazine ; Calmodulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Saccharomyces cerevisiae α factor pheromone arrest growth of cells of the a mating type (MAT a) at the G1 phase of the cell cycle. When treatment of MAT a cells with α factor was carried out in the presence of anticalmodulin drugs, trifluoperazine or chlorpromazine, the extent of cell growth arrest induced by α factor was reduced or even became undetectable. These results lend support to the hypothesis that calmodulin plays a role as mediator in the action of α factor on MAT a cells.
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  • 47
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    Archives of microbiology 146 (1986), S. 214-220 
    ISSN: 1432-072X
    Keywords: Yeasts ; Cell wall ; Mannoproteins ; Aculeacin A ; Glucan ; Protoplasts ; Saccharomyces cerevisiae
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    Topics: Biology
    Notes: Abstract Inhibition of the synthesis of alkali-insoluble glucan by aculeacin A in Saccharomyces cerevisiae cells caused a decrease in the incorporation of a high molecular weight heterogeneous mannoprotein material and of a 33000 mannoprotein into the wall network. This was concomitant with the excretion of the latter molecule into the growth medium. Regenerating yeast protoplasts liberated considerable amounts of the heterogeneous material to the medium independently of the presence of aculeacin. The protoplast walls did lack this component and contained only minor amounts of the 33000 molecule, which was also completely absent from walls of aculeacin-treated protoplasts. Considerable levels of the 33000 species were immunodetected in the supernatants from treated and untreated protoplasts. These results point to the existence of specific interactions between the glucan network of the yeast cell surface and some of the wall mannoproteins. On the other hand, the presence of a population of SDS-solubilizable mannoproteins in the wall was independent of glucan levels.
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    Archives of microbiology 146 (1986), S. 221-226 
    ISSN: 1432-072X
    Keywords: Exoglucanase ; Saccharomyces cerevisiae ; Secretory mutants
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    Topics: Biology
    Notes: Abstract Representative conditional yeast secretory mutants, blocked in transport of secretory and plasma membrane proteins from the endoplasmic reticulum (sec 18), from the Golgi body (sec 7) and in transport of secretory vesicles (sec 1), accumulated exoglucanase, a constitutive yeast activity, when incubated at the restrictive temperature (37°C). Different proportions of the accumulated activity were released by mutant cells under permissive conditions. The presence or absence of cycloheximide during the secretion period made no differences in the results. More than 90% of the internal activity was bound to membrane in wild type cells. However, only the soluble pool underwent changes during the accumulation or secretion periods. The bulk of secretory invertase accumulated by sec 1 was also soluble. By contrast sec 7 and sec 18 accumulated membrane-bound as well as soluble invertase forms and both were secreted in similar proportions in each mutant. More than 90% of the accumulated invertase was secreted at the permissive temperature in sec 18 cells. That percentage was significantly lower for exoglucanase (〈65%). Concomitantly, invertase accumulated by this mutant exited from the cells with a lower half time (t 1/2=150 min). These results may be interpreted assuming that exoglucanase is exported by a passive flow of the soluble pool.
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  • 49
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    Archives of microbiology 145 (1986), S. 32-38 
    ISSN: 1432-072X
    Keywords: Sulphate assimilation ; Adenylylsulphate 3′-phosphotransferase EC 2.7.1.25 ; Escherichia coli ; Saccharomyces cerevisiae ; Enzyme purification ; Enzyme regulation ; Thiredoxin
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    Notes: Abstract Adenylylsulphate kinase (EC 2.7.1.25, ATP:adenylylsulphate 3′-phosphotransferase) has been isolated from Escherichia coli and from Saccharomyces cerevisiae. As major steps of purification, affinity chromatography on Sepharose CL 6B (“blue” or “red”) and chromatofocusing on polybuffer PBE 94tm were employed. The proteins were obtained in nearly homogeneous state after five chromatographic steps. The isolated enzymes from both sources appeared predominantly to exist as dimers. Upon reduction of the protein with dithiothreitol, it desintegrated into assumingly identical smaller subunits (E. coli rom Mr 90-85000 to 45-40000 and s. cerevisiae from 52-49500 to 28-29500). Both forms, dimer and monomer were found catalytically active. Preincubation of the isolated enzyme from either source in the presence of thioredoxin plus DTT, reduced glutathione or DTT increased the activity significantly. Treatment of the enzyme with SH-blocking reagents inactivated the enzyme irreversibly as compared to the inactivation caused by oxidants (2,6-dichlorophenol-indophenol, ferricyanide or oxydized glutathione). This oxidant induced inactivation was less pronounced for the fungal enzyme than for the bacterial protein. The enzyme from E. coli required thioredoxin in order to alleviate the GSSG-induced inactivation.
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  • 50
    ISSN: 1432-072X
    Keywords: Bacillus megaterium ; Saccharomyces cerevisiae ; Ethionine ; Protein degradation ; Abnormal protein
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    Notes: Abstract Degradation of abnormal proteins in Bacillus megaterium and Saccharomyces cerevisiae in vivo was compared with that in cell-free extracts. Protein degradation in vivo, when the cells were labelled with 14C-leucine during growth in the presence of ethionine, was affected by the concentration of the analogue used. Proteins synthesized in the presence of 0.2–1 mM ethionine were degraded most rapidly in both organisms. The proteolytic enzyme system of yeast degraded the analogue-containing proteins in vitro faster than the normal proteins. This holds also for proteins synthesized in the presence of 5 mM ethionine, whose degradation in vivo was impaired. The proteolytic system of B. megaterium, on the other hand, was unable in vitro to differentiate between normal and abnormal proteins. Denatured proteins underwent preferential degradation over normal and ethionine-containing proteins.
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  • 51
    ISSN: 1573-4935
    Keywords: Candida utilis ; cellulase ; DNAse ; β-glucuronidase ; Hansenula jadinii ; protoplast ; Saccharomyces cerevisiae ; Schizosaccharomyces pombe ; spheroplast ; yeast
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Efficient preparation of spheroplasts fromCandida utilis, Saccharomyces cerevisiae, andSchizosaccharomyces pombe, using a purified mixture of enzymes fromTrichoderma harzianum, is described. Limitations of other methods, and differences between yeasts are demonstrated.
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    Molecular genetics and genomics 203 (1986), S. 73-78 
    ISSN: 1617-4623
    Keywords: Catalase T ; CTT1 ; Saccharomyces cerevisiae ; Yeast ; Heme control
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    Topics: Biology
    Notes: Summary The 5′-flanking region of the Saccharomyces cerevisiae catalase T gene (CTT1) and the part of the gene coding for the N-terminus of catalase T were sequenced. 5′-Ends of transcripts of the region were located by S1 nuclease mapping and primer extension. To analyse control elements in the upstream region, a CTT1-lacZ gene fusion was constructed. Deletion analysis was carried out within a part of the 5′-flanking region showing homology to the upstream region of the yeast CYC1 gene. Like the CTT1 gene, this gene is controlled by heme, oxygen and glucose. The results obtained show that the CTT1 gene is positively controlled by heme. Tentative evidence has been obtained for the involvement of upstream sequences homologous to USA1 and USA2 of the CYC1 gene in heme control. Further, a negative site has been located between the upstream activator sites and the transcription start. Within this negative region a ten base-pair sequence was detected that shows high homology to a sequence located within a negative control region of the CYC1 gene and some homology to the negative control elements of the S. cerevisiae CAR1 and CAR2 genes.
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  • 53
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; Gene expression ; Cell cycle
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    Notes: Summary We have examined the pattern of transcription exhibited by four genes in the dTTP biosynthetic pathway of Saccharomyces cerevisiae. Consistent with the results reported previously by Storms et al. (1984), the TMP1 (or CDC21) gene encoding thymidylate synthase was found to be transcribed in a periodic manner during the cell cycle with maximal mRNA levels occurring just prior to the onset of DNA replication. Three other genes in this pathway DCD1, DUT1 and DFR1 encoding dCMP deaminase, dUTP pyrophosphatase and dihydrofolate reductase, respecitively, exhibited relatively constant levels of transcription throughout the cell cycle. These results, particularly for DFR1, are in marked contrast with those obtained in other eukaryotic systems which have suggested that, in general, genes encoding enzymes involved in DNA precursor synthesis are subject to cell cycle regulation. Thus, periodic transcription is not a property common to all genes involved in DNA replication in this eukaryote.
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    Molecular genetics and genomics 205 (1986), S. 422-427 
    ISSN: 1617-4623
    Keywords: SUC2 gene ; Active chromatin ; DNase I hypersensitive sites ; Saccharomyces cerevisiae
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    Topics: Biology
    Notes: Summary The DNase I sensitivity of chromatin of the yeast SUC2 gene, which encodes two forms of invertase, has been studied both in the genome and in a multicopy plasmid carrying the gene and its flanking sequences. Whereas little if any difference in the DNase I sensitivity of the flanking regions was found between the repressed and the derepressed states, derepression of the gene was accompanied by a large increase in the sensitivity of the transcribed region. A well-defined DNase I hypersensitive site was found centered at ∼ 120 bp downstream from the end of the coding region. This site seems to be flanked in the 3′ non-coding region by strictly positioned nucleosomes, and the structure of this region changes upon derepression. In the 5′ non-conding region two DNase I hypersensitive sites have been found flanking the TATA box and a set of three closely spaced hypersensitive sites occurs in an upstream regulatory sequence. The structure of these latter sites depends on the on-off state of transcription.
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  • 55
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; ARO3 gene ; DAHP synthase ; Regulation ; Gene cloning
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    Notes: Summary Regulation of the two isozymes of 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHP synthase; EC 4.1.2.15) encoded by the genes ARO3 and ARO4 of Saccharomyces cerevisiae was studied. Both genes were shown to respond equally well to the general control of amino acid biosynthesis. Strains with mutations in these two genes were obtained by selecting first for a single aro3 mutation and afterwards for a double aro3 aro4 mutation. Gene ARO3, coding for the phenylanine-dependent isozyme of DAHP synthase was cloned on the 2 μm multicopy vector pJDB207 by complementation of mutation aro3-1 in yeast. The ARO3 gene, carried originally on a 9.6 kb BamHI fragment (plasmid pME541A), was subcloned on a 1.9 kb HindIII-XbaI fragment (plasmid pME543). A transcript of about 1.5 kb was shown to proceed from the HindIII towards the XbaI site. Expression from the 9.6 kb as well as from the 1.9 kb fragment was normal on a multicopy vector, since in both cases DAHP synthase levels of about 50-fold the wild-type level were observed.
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  • 56
    ISSN: 1617-4623
    Keywords: Saccharomyces cerevisiae ; Arginase ; Regulation of gene expression
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    Notes: Summary We localized the chromosomal targets of several of the regulatory controls of expression of theCAR1 gene. Fusion tolacZ of several fragments of the 5′ non-coding region showed that induction ofCAR1 by arginine is positively regulated by the products of theARGR genes. The target lies upstream of another site where repression by the CARGRI molecule occurs. The latter control is not specific to arginine catabolism since it also affectsCYC-1 and indeed does not appear to involve arginine. The primary target of the two other regulatory allelesCARGRII andCARGRIII is not situated in the 5′ non-coding region. Deletion analysis supports the fusion data and confirms the order of the regulatory regions: 5′—nitrogen catabolite repression—activation by arginine—CARGRI-mediated repression—CAR1.
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    Molecular genetics and genomics 202 (1986), S. 42-47 
    ISSN: 1617-4623
    Keywords: Minicells ; Histidinol phosphatase ; Recombinant plasmids ; Salmonella typhimurium ; Saccharomyces cerevisiae
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    Topics: Biology
    Notes: Summary The bifunctional enzyme imidazoleglycerolphosphate dehydratase and histidinolphosphate phosphatase is encoded by the hisB gene. The fourth gene of the histidine operon, hisB, was cloned and mapped on a 2,300 base pair DNA fragment. In the present study we report the complete nucleotide sequence of the hisB gene of Escherichia coli. The gene is 1,068 nucleotides long and codes for a protein of 355 amino acids with an apparent molecular weight of 39,998 daltons. The protein product(s) of the hisB region of both Salmonella typhimurium and E. coli were identified by subcloning and expression in an in vitro translation system. In both organisms the hisB gene directed the synthesis of a single protein with an apparent molecular weight of 40,500 daltons, consistent with the data derived from the nucleotide sequence analysis.
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    Plant systematics and evolution 151 (1986), S. 163-174 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Briza ; Cluster analysis ; seed proteins ; electrophoresis ; grass systematics
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    Notes: Abstract The species ofBriza L. s. l. are disjunctly distributed between Eurasia and South America. A taxometric analysis has been carried out, using data from electrophoresis of seed polypeptides and published morphological characters. Evidence from a cluster analysis of seed polypeptide data strongly supports the recognition of two different natural groups, a S. American group and a Eurasian group, and is consistent with karyotype data, but does not support the generic groupings of South American taxa derived from the morphological data.
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    Plant systematics and evolution 151 (1986), S. 145-161 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Araceae.— Pollen nuclear number ; embryology ; evolution of trinucleate pollen ; irreversible evolutionary trend
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    Notes: Abstract Data on pollen nuclear number are presented for 74 of the 111 currently accepted genera of theAraceae — one of only three monocot families in which both bi- and trinucleate pollen are known to occur. Binucleate pollen, which characterizes 65% of aroid genera, is regarded as the primitive type inAraceae and monocots as a whole. The trend toward the trinucleate condition appears to be irreversible, and to have occurred many times within the family.Syngonium becomes the sixth angiosperm genus in which both character-states are known to occur; otherwise, the character is highly conservative at the generic level. Pollen nuclear number shows no evident correlation with pollen size, starch content or pollinator type.
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    Plant systematics and evolution 151 (1986), S. 215-222 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Gunneraceae ; Haloragaceae ; Hippuridaceae. — Sieve-element plastids ; ultrastructure and systematics
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    Notes: Abstract P-type sieve-element plastids were found in theGunneraceae, while S-type plastids are present in theHaloragaceae andHippuridaceae. The specific characters of the sieve-element plastids (e.g., their size and the morphology of their contents) are discussed in relation to other taxa of theRosidae containing P-type plastids and to the systematic position of theGunneraceae.
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    Plant systematics and evolution 151 (1986), S. 187-202 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Orchidaceae ; Thelymitra nuda ; Liliaceae ; Dichopogon ; Thysanotus ; Halictidae ; Lasioglossum ; Syrphidae. — Mimesis ; pollinaria ; staminodal hood ; thoracic vibration ; trichome cluster. — Flora of Australia
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    Notes: Abstract Insect pollination occurred inThelymitra nuda R. Br. on sunny days when the ambient temperature exceeded 20 °C. The flower buds on a raceme opened subsynchronously displaying the brightly-colored, actinomorphic perianth and exposed the contrastingly-colored, scented and ornamented column. InT. nuda the staminodes and the filament of the fertile stamen are fused to one another producing an inflated hood over the anther. This staminodal hood is terminated in two non-ornamental, but brightly-colored, central lobes and two terete lateral lobes bearing approximately 400 white trichomes. Each trichome bears a double chain of 30–40 spherical, rugulose cells. Female bees, in the genusLasioglossum (Halictidae), were observed to land directly on the hood and curled their bodies around the four lobed tip of the staminodal complex. The bees attempted to forage on the lobes as if they were collecting pollen from fertile, poricidal stamens. These bees applied thoracic vibration to the yellowish central lobes and actively scraped the trichome clusters (Pseudopollen) with their forelegs. Bees carried the pollinaria ofT. nuda dorsally on their abdomens. Abdominal contact with the rostellum appeared to occur when the female bee disengaged herself from the staminodal hood. Observations made of bees on co-blooming flowers, and analyses of pollen loads collected by bees suggested that the orchid flower mimics the guild of blue-purple flowers that lack floral nectar but offer pollen in poricidal anthers. The models ofT. nuda are co-bloomingLiliaceae in the generaDichopogon andThysanotus. However, nectarless, buzz-pollinated flowers are also extensively distributed over the orchid’s range. More than 30% of the flowers in theT. nuda population had their pollinaria removed, suggesting a high capacity for cross-pollination in an orchid genus usually considered to be self-pollinated via mechanical autogamy. This study confirmed previous predictions that column modifications represented a trend towards pseudanthery.
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    Plant systematics and evolution 151 (1986), S. 203-213 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Psathyrostachys juncea ; P. huashanica. — Chromosomes ; Giemsa ; C-banding patterns ; chromosome polymorphism ; nucleoli
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    Notes: Abstract The karyotypes ofP. juncea (Elymus junceus) andP. huashanica (both outbreeders) were investigated by Feulgen-staining and by C-, N-, and Agbanding, based on a single plant in cach case. Both species have 2n=2x=14 and large chromosomes, possibly a generic character. The karyotype ofP. juncea has 8 metacentrics and 6 SAT-chromosomes with minute, heterochromatic satellites while that ofP. huashanica has 9 metacentrics and 5 SAT-chromosomes only, 2 of which with small, heterochromatic satellites. The C-banding patterns ofP. juncea chromosomes comprise from one to five, mostly small, bands at distal, and terminal positions, while those ofP. huashanica chromosomes are characterized by large telomeric bands in most arms. Banding patterns and chromosome morphology allow identification of the homologues of the seven chromosome pairs inP. juncea, but of two pairs inP. huashanica only. The patterns of both taxa are polymorphic, supporting that both taxa are outbreeders. The karyotypic characters suggest thatP. juncea is more closely related toP. fragilis than either is toP. huashanica. N-banding stains weakly. Silver nitrate staining demonstrates that nucleolus organizers of both species have different nucleolus forming capacities. The presence of micronucleoli suggests that both species have an extra unidentified chromosome with nucleolus forming capacity.
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    Plant systematics and evolution 151 (1986), S. 223-228 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Hydrophyllaceae ; Nama. — Chemotaxonomy ; flavones ; 6-methoxy flavones ; C-glycosyl flavones
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    Notes: Abstract Eight flavonoids, four 6-oxygenated flavones, two methyl ethers of luteolin, apigenin 6,8-C-diglucoside and quercetin 3-O-glucoside, were isolated fromNama lobbii andN. rothrockii, sole members of sects.Arachnoidea andCinerascentia, respectively. Both taxa diverge markedly from other namas in morphology and chromosome number and their placement inNama has been questioned. The occurrence of 6-oxygenated flavones in these taxa adds to their already distinctive nature. Flavonoid evidence argues that both are more closely allied toEriodictyon than either is toNama.
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    Plant systematics and evolution 151 (1986), S. 229-239 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Astereae ; Osbertia ; O. chihuahua sp. n. ; Heterotheca ; Chrysopsis ; Pityopsis ; Noticastrum ; Erigeron ; Haplopappus. — Taxonomy. — Flora of Mexico
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    Notes: Abstract Osbertia, a stoloniferous group confined to the montane regions of Mexico and adjacent Guatemala, was first proposed as a genus byGreene (1895), but most workers have retained the taxon as part ofHaplopappus. It is clearly closer toNoticastrum, Erigeron orHeterotheca than it is toHaplopappus sensu stricto. The present treatment recognizes two species, a widespread highly variableOsbertia stolonifera and a newly describedO. chihuahuana from northwestern Mexico. Distribution maps, distinguishing features, full synonymy and illustrations are presented.
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    Plant systematics and evolution 151 (1986), S. 241-269 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Scrophulariacae ; Rhinanthoideae ; Euphrasia ; E. minima ; E. tatrae ; E. mendonçae ; E. willkommii. — Polyploid complex ; evolution of tetraploid species ; chorology and history of the Alpic flora ; new chromosome counts. — Flora of Europe ; of Turkey
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    Notes: Abstract A systematic analysis of the variable and probably allotetraploidE. minima is presented, its infraspecific taxonomy is discussed.E. tatrae is provisionally included intoE. minima although some differences may exist;E. mendonçae may be a relic of a formerly wider distribution ofE. minima; E. willkommii seems to be closer toE. stricta s. lat. than toE. minima. 4x-E. minima is supposed to be derived from phylogenetic lines close to extant dwarf alpine forms of 2x-E. alpina (including its yellow flowering subsp.christii;Vitek 1985b) and 2x-E. hirtella (vgl.Vitek 1985a). Some characteristics (e.g., its small flowers) could have been introduced through hybrid introgression from other 2x-species, particularlyE. inopinata and/orE. sinuata (vgl.Ehrendorfer & Vitek 1984).
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    Plant systematics and evolution 152 (1986), S. 47-48 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Lauraceae ; Ocotea ; Sex distribution ; dioecy ; Flora of South America
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    Notes: Abstract The evolution of dioecy inLauraceae cannot be attributed to selection for outbreeding but must have other reasons. Therefore it is interesting to note that inOcotea there seems to be a correlation between mode of reproduction and geographical distribution.
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    Plant systematics and evolution 152 (1986), S. 29-45 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Annonaceae ; Araceae ; Arecaceae ; Bignoniaceae ; Cyclanthaceae ; Magnoliaceae ; Malpighiaceae ; Malvaceae ; Nymphaeaceae ; Flowering phenology ; pollination strategies ; flower ecological radiation: neotropical savannas and forests ; melittophily ; nectar robbery ; “oil-flowers” and “oil-bees” ; ornithophily ; chiropterophily ; cantharophily:Dynastinae beetles ; flower evolution
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    Notes: Abstract Previously published data on flowering phenology and pollination of neotropical families are reviewed and compared with new observations, in order to evaluate some trends of pollination strategies in neotropical savannas and forests. Central American forestBignoniaceae apparently diminish competition between sympatric species with identical pollination strategies by alternating flowering. On the other hand, in theBignoniaceae of Brazilian cerrado savannas coincident flowering is more common, suggesting different pollination strategies. Bees specialized in nectar robbery are associated withBignoniaceae, particularly mass-flowering species. These nectar robbers stimulate pollinator movements between flowers and thus increase pollen-flow. The flowering phenology of theMalpighiaceae from forests and savannas apparently follows the phenology of theAnthophorinae (mainlyCentridini)-bees, on which this plant group almost exclusively depends for pollination in the Neotropics. As the flowers of different genera and species are very uniform, the bees quite indiscriminately pollinate coexistingMalpighiaceae taxa. In theMalvaceae, the more primitive tree or shrub habit and an allogamous reproduction system is quite significantly associated with an ornithophilous pollination mode. Hummingbirds in the Neotropics have probably influenced the origin of the primitive bird-pollinatedMalvaceae flower. In conjunction with the diversification of theMalvaceae and their migration into more open regions, pollination by bees has apparently become more prominent. ChiropterophilousMalvaceae seem to have developed more recently from ornithophilous ancestors within the neotropical forest regions. As a result of this ecological radiation, parallel modifications of the basic ornithophilous flower principle can be traced in different groups of theMalvaceae. Dynastinae-beetles are pollinators of South and Central American species ofAnnona, Cymbopetalum, Caladium, Talauma, Philodendron, Victoria, Nymphaea, Cyclanthus, Bactris and others. In many cases the relationship between flowers and theirDynastinae visitors is not very specific, principally reflecting differences in the faunistic spectrum of diverse regions and vegetation types. The attraction of these beetles as flower visitors in several unrelated groups of Angiosperms must have occurred repeatedly. It is suggested that the flower visiting species of this beetle group may have acquired their preference for certain pungent or aromatic flower odours by their feeding habits during the larval stage.
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  • 68
    ISSN: 1615-6110
    Keywords: Angiosperms ; Gymnosperms ; Cycadales ; Austrobaileyaceae ; Austrobaileya ; Sieve cells ; sieve tubes ; ultrastructure of sieve pores ; p-protein ; sieve-element terminology
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    Notes: Abstract The ultrastructure of the sieve elements ofAustrobaileya is compared with that of angiosperm sieve tubes and gymnosperm sieve cells (mostly fromCycadales). Except for the size of the sieve poresAustrobaileya shares all ultrastructural characters (e.g., chromatolytic nuclear degeneration, presence of p-protein, formation of sieve pores from unbranched plasmodesmata) and other features (e.g., companion cells) with angiosperm sieve tubes. Gymnosperm sieve cells on the contrary are characterized by pycnotic nuclear degeneration, absence of p-protein, formation of sieve areas from branched plasmodesmata with median cavities. — The exact ordinal assignment ofAustrobaileya within the subclassMagnoliidae is still disputed, a placement close to eitherMyristicaceae andWinteraceae orMonimiaceae being possible as judged from both S-type sieve-element plastids and p-protein bodies. — On the basis of the ultrastructural results fromAustrobaileya it is proposed to reconsider concepts and terminology of sieve elements. i.e., to include features from sieve pore development, nuclei degeneration and presence of specific proteins into the definitions and to restrict the term sieve cell to gymnospermous sieve elements which differ much from those of other vascular plants.
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    Plant systematics and evolution 152 (1986), S. 49-100 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Magnoliales ; Laurales ; Violales ; Malvales ; Chromosome numbers ; karyomorphology ; banding patterns ; polyploidy ; triploidy ; evolution and systematics in tropical woody plants
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    Notes: Abstract New karyological data are reported ofMagnoliidae, Violales, Malvales and some other orders. These data include for 102 species from 51 genera and 18 families chromosome counts, karyotypes, interphase nuclear structures and banding patterns. Karyomorphology suggests a new systematic arrangement for theLaurales (Fig. 11), a new circumscription of theCymbopetalum tribe (Annonaceae), and a placement of theCochlospermaceae/Bixaceae in theViolales. ForAnnonaceae andMagnoliidae x = 8 is proposed as the original base number. A model based on extant chromosome numbers inAnnonaceae and combining short dysploid series and polyploidization can explain most of the existing numbers in this family and in the otherMagnoliidae (Fig. 16). Special attention is drawn to the role of triploids and other anorthoploids in chromosome number diversification (e.g., inAnnonaceae, Apocynaceae, Proteaceae). Identical polyploid numbers are shown to have originated from different base numbers. The highest chromosome number forMagnoliidae is found inMyristicaceae (Osteophloeum: 2n = 280). Polyploid relic genera frequently exhibit highly differentiated and “diploidized” karyotypes with many structural rearrangements. The step diploid polyploid is correlated in several genera with the invasion from humid to more extreme, often xeric habitats. Polyploidy serves as a crossing barrier in related syntopic species. InAnnonaceae, Cochlospermaceae andMyristicaceae neotropical taxa have a higher polyploidization rate than palaeotropical ones. — Subsequential fluorochrome-and Giemsa C-banding demonstrates the following pattern for tropical woody plants: Chromosomes mostly have neutral (neither AT- nor GC-rich) proximal heterochromatin (= hc), intercalarly and/or terminal bands are rare. In some cases great variation occurs in regard to location and composition of bands between the investigated taxa. Differences concern genera, species groups or species. Diploid karyotypes tend to contain less different hc-types than polyploid ones. NO-chromosomes also exhibit a remarkable banding pattern differentiation. In general, hc-variation is greater in respect to composition than to distribution.
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    Plant systematics and evolution 152 (1986), S. 123-131 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae ; Dendrosenecio ; Age determination ; ecophysiology ; phylogeny ; population dynamics
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    Topics: Biology
    Notes: Abstract The genusDendrosenecio (“giant groundsels”), encompassing three species and 12 subspecies, is endemic to the high mountains of East and Central Africa where it constitutes the most conspicuous components of the afroalpine vegetation. Two lifeforms, the arborescent and the prostrate rhizomatous, are regarded as the results of evolution from forest-living woody or herbaceous ancestors. Due to the uninterrupted growth period in the tropics, there are no anatomical or morphological features which allow conventional age determination. However, stem elongation rates have been determined (3–5.5 cm per year) and indicate an age of about 250 years for the tallest arborescent Dendrosenecios which may reach a height of 10 m. 30 to 120 large leaves are clustered in an enormous terminal rosette, justifying the term “giant rosette” plants. A leaf bud, consisting of about as many developing leaves as the rosette contains, is found in the center. During the nocturnal frost period the adult rosette leaves form a so-called night-bud by nyctinastic upwards bending and thus protect the leaf bud from freezing by insulation. The stem is surrounded by a mantle of persistent dead leaves; this ameliorates the microclimate of the pith-cells which greatly contribute to water transport into the leaves. Below the leaf rosette a zone of putrefaction is found, from where the decay of the dead leaves apparently provides nutrients directly to the growing stem. The population dynamics of the arborescentD. keniodendron is characterized by a simultaneous inflorescence development at irregular intervals of up to more than twenty years. Due to sporadic flowering and a seedling survival rate of less than 1%, oscillations of the population size are to be expected.
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    Plant systematics and evolution 152 (1986), S. 153-166 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Festuca ; Evolution ; seed proteins ; electrophoresis
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    Notes: Abstract Seed protein electrophoresis of four chromosomes races ofFestuca arundinacea, F. mairei and their progenitors showed variation in banding patterns. High protein similarities betweenF. arundinacea, F. mairei, F. scariosa, andF. pratensis indicate close phylogenetic relationships of these species. The ancestry ofF. arundinacea cytotypes could be narrowed to three diploid species:F. scariosa, F. pratensis, andF. rubra or to their close relatives.
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    Plant systematics and evolution 152 (1986), S. 133-151 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Cucurbitaceae ; Luffa cylindrica ; L. acutangula ; Benincasa hispida ; Coccinia indica
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    Notes: Abstract DNA sequence organization patterns have been studied in fourCucurbitaceae plant species, namely,Luffa cylindrica (sponge gourd),L. acutangula (ridge gourd),Benincasa hispida (ash gourd) andCoccinia indica (ivy gourd). Extensive interspersion of repeat and single copy sequences has been observed in sponge gourd and ridge gourd. In ash gourd and ivy gourd, however, there is a limited interspersion of these sequences and a large portion of the single copy DNA remains uninterspersed. The interspersed repetitive sequences are composed of a major class (75–80%) of short repeats (300 base pairs long) and a minor class (15–20%) of long repeats (2 000–4 000 base pairs) in all the four species. The average length of single copy sequences dispersed among repeats is 1 800–2 900 base pairs. In spite of these gross similarities in the genome organization in the four species, the fraction of repeats and single copy sequences involved in short and long period interspersion patterns, and fraction of single copy sequences remaining uninterrupted by repeats are vastly different. The probable implications of these differences with respect to speciation events and rates of genome evolution are discussed.
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    Plant systematics and evolution 152 (1986), S. 167-183 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Lamiaceae ; Sideritis ; Meiotic behaviour ; karyotypes ; size and fertility of pollen grains ; DNA values ; seed protein electrophoresis ; phylogenetic relationships
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    Notes: Abstract Six closely related taxa of the sect.Eusideritis of the genusSideritis (S. leucantha, S. pusilla, S. flavovirens, S. granatensis, S. biflora andS. osteoxylla) are analysed to elucidate their phylogenetic relationships and position within the sect.Eusideritis. Meiotic behaviour, karyotype features, size and fertility of pollen grains, DNA amounts and seed protein profiles are reviewed. A polyploid origin of the group (from x = 7) and the further diversification through dysploidy and chromosome repatterning is postulated.S. osteoxylla is apparently of hybrid origin.
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    Plant systematics and evolution 152 (1986), S. 185-194 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asclepiadaceae ; Calotropis procera ; Xylocopa ; Pollen germination ; nectar concentration ; robbery by ants ; Flora of Israel
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    Notes: Abstract Calotropis procera (Asclepiadaceae) grows in Israel under extremely hot climatic conditions. Flower morphology is adapted towards the concealment of nectar, in order to protect it against robbery by ants and from evaporation. Pollinia while being inserted within the stigmatic chamber, are soaked in the liquid nectar which, by its concentration controls pollen germination. Two Carpenter bees (Xylocopa) are the only pollinators and their behavior on flowers is discussed.
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    Plant systematics and evolution 152 (1986), S. 211-218 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Rosaceae ; Malachobatus ; Rubus ; Taxonomy ; crossing experiments ; apomixis ; chromosome numbers
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    Topics: Biology
    Notes: Abstract A review of current knowledge of chromosome numbers and modes of reproduction in the genusRubus L. is presented. Chromosome numbers from some species of subg.Malachobatus Focke together with results of crossing experiments are reported for the first time.
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    Plant systematics and evolution 152 (1986), S. 219-230 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Cyperaceae ; Scleria foliosa ; Embryology: endosperm haustoria ; cotyledon ; systematics
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    Notes: Abstract The embryology ofScleria foliosa A. Rich. is described and several features have been recorded for the first time in the family. The endosperm having both micropylar and chalazal haustoria and embryo with characteristic cotyledon bearing papillate outgrowths are unique features noted in this taxon. The epicotylary and cotyledonary sectors are adjacently placed and occupy a terminal position on the embryonic axis. Taxonomic implications of the embryological findings with particular reference to the problem of circumscription ofScleria are discussed.
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    Plant systematics and evolution 152 (1986), S. 195-210 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Asteraceae (Compositae) ; Anthemideae ; Artemisia ; Chromosome banding ; heterochromatin ; karyosystematics
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    Notes: Abstract Detailed C-banded karyotypes of eight diploidArtemisia species from three different sections are reported together with preliminary observations on three additional related diploid species. In the majority, the overall amount of banding is relatively low. Bands are mostly confined to distal chromosome regions; intercalary banding is virtually absent and centromeric heterochromatin is also scarce. With the exception ofA. judaica there is in general great uniformity in karyotype structure but considerable interspecific variation in total karyotype length (and hence DNA content) ranging from 44 µm inA. capillaris (2n = 18) to 99 µm inA. atrata (2n = 18).A. judaica (2n = 16; total karyotype length 97 µm) was distinguished by its karyomorphology, with one large non-banded metacentric chromosome pair and 7 pairs of smaller terminally banded meta- or submetacentric chromosomes.
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    Plant systematics and evolution 152 (1986), S. 231-241 
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    Keywords: Angiosperms ; Dilleniaceae ; Hibbertia fasciculata ; Lasioglossum (Halictidae) ; Leioproctus (Colletidae) ; Myrtaceae ; Bees ; beetles ; floral symmetry ; stamens ; stigmas
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    Notes: Abstract In direct contrast to mostHibbertia spp., the flowers ofH. fasciculata R. Br. ex D. C. bear only a single whorl of stamens and these stamens are arranged separately (not in typical “bundles”). The short filaments are appressed to the three carpels so that the inflated, porose and introrsive anthers form a centralized cluster obscuring the three ovaries. The three slender styles emerge at right angles from between the filaments. These styles curve upward and the stigmas form the three points of a triangle; each stigma is approximately one millimeter outside the centralized cluster of anthers. The flowers are nectarless and bear a bright yellow corolla. A pungent and unpleasant fragrance appears to be concentrated within the pollenkitt. When native bees attempt to forage for the pollen, within the cluster of anthers, the ventrally deposited loads of pollen, on the bees' abdomens, contact the outer triangle of stigmas. The major pollinators ofH. fasciculata are female bees in the polylectic genera,Lasioglossum (subgenusChilalictus, Halictidae) andLeioproctus (Colletidae). These bees carry an average of more than two pollen taxa when they are caught foraging onH. fasciculata. 78% of the 47 bees, captured onH. fasciculata carried the pollen from at least one sympatric taxon bearing nectariferous flowers (e.g., genera in theMyrtaceae, Compositae, andEpacridaceae). The pollination biology ofH. fasciculata is assessed in relation to the known radiation of bee-pollinated flowers in the genusHibbertia, and within theDilleniaceae s. l.
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    Plant systematics and evolution 152 (1986), S. 267-276 
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    Keywords: Angiosperms ; Plumbaginaceae Dyerophytum africanum ; D. indicum ; Ceratostigma abyssinicum ; Linum ; Distyly ; dimorphic pollen ; exine sculpturing
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    Notes: Abstract Light and SEM observations on the pollen ofDyerophytum africanum andD. indicum have revealed marked differences in exine features. These distylous species also have dimorphic pollen. In the short-styled individuals of both species, the sexine and nexine are of equal thickness, and the clava-like sexinous processes are short without marked projections. In the long-styled individuals, the sexine is thicker than the nexine, the clavae are higher than broad with an apical spinule. Pollen size and apertures are identical in both morphs. — Palynological evidence is presented for relationships betweenDyerophytum andCeratostigma, Plumbago andAegialitis. Moreover, the genusDyerophytum exhibits pollen morphological similarities with some species ofLinum (Linaceae).
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    Plant systematics and evolution 152 (1986), S. 277-296 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Cruciferae ; Capsella bursa-pastoris ; Adaptation ; inception of flowering in natural populations ; phenotypic and genotypic variability
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    Notes: Abstract Seed samples were collected from wild populations ofCapsella bursa-pastoris along a transsect from Northern to Southern Europe. Progeny was grown in (a) open-field random block experiments (47 populations) and (b) in growth chambers under five to seven controlled temperature regimes (18 populations). Beginning of flowering was recorded, and great differences between and also within populations are documented. Some populations are extremely heterogenous whereas others are homogenous in this respect. Some biotypes react positively when exposed to lower temperatures, others are inhibited. In many cases specific effects of day- and/or night-temperatures can be inferred. In some progenies begin of flowering is independent of temperature as long as this exceeds the 5:10°C regimen. Altogether,Capsella bursa-pastoris displays definite intraspecific variation in time required until flowering. Adaptations to local ecological conditions are obvious. In addition to a genotypic component pronounced environmental interactions provide the plants with a component of phenotypic plasticity. The degree of modificability apparently varies itself and seems to be controlled by selection; the phenotypic plasticity, therefore, displays adaptive variation patterns, too.
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    Plant systematics and evolution 153 (1986), S. 1-5 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Fabaceae ; Trigonella ; fenugreek ; Karyotype ; C-banding ; evolution
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    Notes: Abstract The six species of the sectionFoenum-graecum ofTrigonella have the same chromosome number, 2n = 16.T. gladiata andT. cariensis have fairly symmetrical karyotypes, while those ofT. foenum-graecum, T. berythea, T. macrorrhyncha andT. cassia are asymmetrical. C-bands are present in all six species but the number of bands and their positive vary considerably among the species. The karyotype evidence suggests that none of the available species of theFoenum-graecum section can be considered as the wild progenitor of fenugreek.
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    Plant systematics and evolution 153 (1986), S. 7-12 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Vulpia sectt.Loretia ; Vulpia Monachne ; Morphology ; seed protein electrophoresis ; numerical systematics
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    Notes: Abstract Seven species ofVulpia were subjected to morphological and protein studies using principal component and cluster analysis and theJaccard's Similarity Coefficient. Studies showed all species were uniform and distinct from each other. Species of sect.Loretia were very dissimilar from those of sect.Monachne and sect.Vulpia. The latter section comprises taxa of high mutual affinity.
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    Plant systematics and evolution 153 (1986), S. 31-36 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Hydrocharitaceae ; Limnobium spongia ; Somatic chromosome number ; karyotype analysis ; Limnobium versusHydromystria
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    Notes: Abstract The somatic chromosomes ofLimnobium spongia have been studied for the first time. Its number is 2n = 24; the karyotype is composed of 5 m pairs + 3 sm pairs + 4 st pairs. Pairs 3 and 11 bear microsatellites. Results are compared with previous chromosome reports for the family, mainly as regards the taxonomic status ofLimnobium versusHydromystria; our findings seem to support the point of view of those who favour the independence of both generic entities.
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  • 84
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    Keywords: Angiosperms ; Poaceae ; Triticum dicoccoides ; Uredinales ; Puccinia striiformis ; Wild emmer ; pathogene resistances ; ecology ; allozyme genotypes ; statistic analyses ; Flora of Israel
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    Notes: Abstract From 114 accessions of wild emmer wheat from 11 sites in Israel, known for their allozymic variation (Nevo & al. 1982), individual genotypes were tested for resistance to one isolate of stripe rust both in the seedling stage in a growth chamber and in the adult plant stage in the field. The results indicate that resistance to stripe rust in seedlings and adults are significantly correlated (rs = 0.40, p 〈 0.001). Genetic polymorphisms of resistance to stripe rust vary geographically and are predictable by climatic, as well as allozymic markers. Three variable combinations of rainfall, evaporation, and temperature explain significantly 0.40–0.53 of the spatial variance in disease resistance to stripe rust, suggesting the operation of natural selection. Several allozyme genotypes are significantly associated with disease resistance. We conclude that natural populations of wild emmer wheat in Israel contain large amounts of disease resistance genes. These populations could be effectively screened and then utilized by the phytopathologist for identifying resistant genotypes and producing new resistant cultivars.
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    Plant systematics and evolution 153 (1986), S. 49-64 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Hordeum spp. ; Interspecific hybridization ; relationships
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    Notes: Abstract A crossing programme including 30 species and 40 cytotypes within the genusHordeum was undertaken. Viable hybrids were obtained in 302 combinations, 15 of which were intraspecific. Differences in seed set and in germination were observed in crosses between different groups of species. Obtaining crosses between different taxonomic groups was generally more difficult when diploid material was used. Some species, e.g.,H. lechleri, H. jubatum, andH. brachyantherum showed a higher crossability than others. The chromosome numbers of the hybrids were usually those expected from the parental numbers but aneuploid series around the expected numbers were rather frequent. Three cases of unreduced gametes were found. Selective chromosome elimination was restricted to combinations including eitherH. vulgare orH. bulbosum.—Despite a very diverse morphology, all South American diploid species together with the two North American diploidsH. intercedens andH. pusillum appear to be closely related. The hexaploid American speciesH. procerum, H. lechleri, andH. arizonicum are also related. The two North American tetraploid speciesH. jubatum andH. brachyantherum sometimes form semifertile hybrids. The Asiatic speciesH. roshevitzii appears to be related to both North and South American taxa.
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    Plant systematics and evolution 153 (1986), S. 65-76 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Orchidaceae ; Prasophyllum odoratum ; Pollination ecology
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    Notes: Abstract Prasophyllum odoratum is a vernal, nectariferous, terrestrial orchid that flowers profusely six to eight months following cyclical fires that disrupt sclerophyll woodlands. The morphology of the column and pollinarium is indicative of taxa placed within the subfam.Spiranthoideae. The orientation of the pollinaria to the stigma appears to prevent mechanical self-pollination. Both cross- and self-pollination appear to be effected by insects that forage within the brightly-colored, scented, non-resupinate flowers. Ants and drosophilid flies remove nectar, but do not appear to transport pollinaria between flowers. The primary pollinators are polytrophic flies in the fam.Syrphidae and opportunistic male bees in the genusLeioproctus (Colletidae). Approximately 52% of the flowers on a raceme set seed. The comparatively short floral tube ofP. odoratum reflects the dependence of this species on short-tongued insects to effect successful dispersal of pollinaria.
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    Plant systematics and evolution 153 (1986), S. 133-139 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Lactoridaceae ; Lactoris ; Flavonoids ; evolution
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    Notes: Abstract Leaves of the monotypic angiosperm familyLactoridaceae exhibit flavonoid constituents consisting of six 3-0-diglycosides of the flavonols kaempferol and isorhamnetin. The presence of flavonols is concordant with the placement ofLactoridaceae among the “archaic” or “primitive” flowering plants. Flavonoid chemistry is less informative on the relationships of the family within the primitive dicots. The presence of isorhamnetin suggests closer affinities with families in theLaurales, particularly theGomortegaceae andMonimiaceae. Phenetic and cladistic analyses of morphological features place theLactoridaceae near several families in theMagnoliales.
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    Plant systematics and evolution 153 (1986), S. 165-170 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Araceae ; Amorphophallus nicolsonianus ; species nova ; Flora of India
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    Notes: Abstract Amorphophallus nicolsonianus species nova, with cylindrical or napiform corms, is the only representative of the sect.Rapyogkos in India. All the other hitherto known species of this region have globose or depressed globose corms. The new species is related to some Indochinese species and toA. hildebrandtii ( Engl.)Engl. & Gehrm. from Madagascar.
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    Plant systematics and evolution 153 (1986), S. 141-164 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Hordeum spontaneum ; Genetic resources ; allozyme polymorphism ; correlation with environmental parameters ; Flora of Iran
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    Notes: Abstract Genetic diversity and structure of populations of the wild progenitor of barleyHordeum spontaneum in Iran was studied by electrophoretically discernible allozymic variation in proteins encoded by 30 gene loci in 509 individuals representing 13 populations of wild barley. The results indicate that: a)Hordeum spontaneum in Iran is extremely rich genetically but, because of predominant self-pollination, the variation is carried primarily by different homozygotes in the population. Thus, genetic indices of polymorphismP-1% = 0.375, range = 0.267−0.500, and of genetic diversity,He = 0.134, range = 0.069−0.198, are very high. b) Genetic differentiation of populations includes clinal, regional and local patterns, sometimes displaying sharp geographic differentiation over short distances. The average relative differentiation among populations isGst = 0.28, range = 0.02−0.61. c) A substantial portion of the patterns of allozyme variation in the wild gene pool is significanctly correlated with the environment and is predictable ecologically, chiefly by combinations of temperature and humidity variables. d) The natural populations studied, on the average, are more variable than two composite crosses, and more variable than indigenous land races of cultivated barely,Hordeum vulgare, in Iran. — The spatial patterns and environmental correlates and predictors of genetic variation ofH. spontaneum in Iran indicate that genetic variation in wild barley populations is not only rich but also at least partly adaptive. Therefore, a much fuller exploitation of these genetic resources by breeding for disease resistance and economically important agronomic traits is warranted.
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    Plant systematics and evolution 153 (1986), S. 181-197 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Poaceae ; Hordeum murinum complex ; wild barley ; Classification ; numerical methods ; conditional clustering
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    Notes: Abstract The purpose of this paper is to produce a classification of theHordeum murinum complex. Using an experimental design to account for the environmental component of the phenotypic variation, material from sources throughout the old-world range ofH. murinum was grown in a common environment. Eight morphological characters were measured on the resulting triplets (i.e., the central and lateral florets, glumes and rachis internode). Clustering, variance and discriminants analyses of these data suggest that there are three distinct groups. This classification is then examined for consistency with hypotheses obtained from the work of other researchers and discussed in light of the known biology of the plants. An identification key to members of the complex using the triplet characters is provided.
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    Plant systematics and evolution 153 (1986), S. 199-204 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Iridaceae ; Crocus sativus L. ; Chromosome number ; karyotype analysis ; meiosis ; univalents ; bivalents ; trivalents ; laggard chromosomes ; inversions ; sterility
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    Notes: Abstract Meiosis and mitosis are described in cultivatedCrocus sativus of Iran. This indicates that this species is an autotriploid and sterile. Karyotype analysis, rare inversions, laggard chromosomes and distribution of chromosomes in the first anaphase are described, and the reasons for its sterility are given.
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    Plant systematics and evolution 153 (1986), S. 223-227 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Leguminosae ; Caesalpinioideae ; Cassia ; Habit ; DNA content ; evolution
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    Notes: Abstract Ten species of the genusCassia show a range of 2C DNA amounts from 1.30 to 2.54 pg at the same ploidy level. Remarkably, a distinct 2-fold increase is depicted by an arboreal speciesC. excelsa while the rest comprising of herbs, trees and shrubs have a range from 1.30 to 1.47 pg. These form a natural grouping with respect to mean DNA amounts which differ by 0.05 pg in the herbs, trees and shrubs respectively.
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    Plant systematics and evolution 153 (1986), S. 205-222 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Geraniaceae ; Pelargonium ; Chromosome numbers ; karyotypes ; hybrids ; karyotype evolution ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The chromosome numbers of seven species ofPelargonium sect.Eumorpha have been determined from material of known wild origin, and karyotypic comparisons have been made. Within the section there is variation in basic chromosome number (x = 4, 8, 9, 11), variation in chromosome size, and two species have polyploid races. The three species with chromosome numbers based on x = 11 have the smallest chromosomes (1.0–1.5 µm); chromosomes are larger (1.0–3.0 µm) in the other species.P. elongatum has the lowest chromosome number in the genus (2n = 8).P. alchemilloides is exceptional in that it has four cytotypes, 2n = 16, 18, 34 and 36, and the form with 2n = 36 has large chromosomes (2.0–5.0 µm). Evidence from a synthesized hybrid suggests thatP. alchemilloides with 2n = 16 may be of polyploid origin. The three species based on x = 11 appear to be more closely related to species from other sections ofPelargonium that have the same basic chromosome number and small chromosome size, rather than to other species of sect.Eumorpha.
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  • 94
    ISSN: 1615-6110
    Keywords: Angiosperms ; Orchidaceae ; Orchis ; Interspecific hybrids ; species identification ; enzyme electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The European orchidsOrchis mascula, O. pallens and their hybrids have been analysed by enzyme electrophoresis on starch gels. The two species differ in the electrophoretic mobilities of four out of eight enzymes tested. Three enzymes, phosphoglucomutase, phosphoglucoisomerase and “malic enzyme” exhibit typical heterozygote patterns in the hybrid plants demonstrating the presence of both differing parental alleles. Thus, species identification is easy by the electrophoretic analysis of a low number of enzyme loci, and hybrids are detectable even if morphological characters fail.
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  • 95
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    Plant systematics and evolution 153 (1986), S. 243-258 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Linaceae ; Linum tenuifolium L. ; L. suffruticosum L. ; L. salsoloides Lam. ; L. appressum Caballero ; Variation ; phenetics ; systematics ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The phenetic variation inL. tenuifolium s.l. was assessed using multivariate analyses of 27 characters found to be variable within the species. These results are discussed and interpreted in the context of the reproductive biology, chromosome number and ecological responses of the taxa. Evidence suggests that both the self-compatible and tetraploid races were derived independently from a self-incompatible, diploid type. Although no taxonomic scheme is compatible with all of the evidence presented, the study supports a recent decision to recognize four taxa at subspecific level.
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  • 96
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    Plant systematics and evolution 153 (1986), S. 259-264 
    ISSN: 1615-6110
    Keywords: Gymnosperms ; Angiosperms ; Pteridosperms ; Caytoniales ; Caytonanthus ; Ultrastructure ; pollen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The pollen grain wall structure ofCaytonanthus arberi was studied with SEM and TEM. The monosulcate, bisaccate pollen grain of this taxon has an alveolar wall structure that is more like that found in saccate Conifers than primitive Angiosperms. Pollen grain morphology does not support a Caytonialean ancestry for the Angiosperms.
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  • 97
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    Plant systematics and evolution 153 (1986), S. 281-285 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Brassicaceae ; Brassica ; Electrophoresis of complete Rubisco ; systematics ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A simple electrophoretic technique for separating Rubiscoholoenzyme (ribulose bisphosphate carboxylase-oxygenase) from crude extracts is introduced. No preliminary purification steps are required. To prove the validity of the technique we rely on well studiedBrassica spp., tobacco and spinach. We recommend this method for studies concerned with intrageneric relationships and for proving the intraspecific constancy of Rubisco.
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  • 98
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    Plant systematics and evolution 153 (1986), S. 265-279 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Cruciferae (= Brassicaceae) ; Capsella bursapastoris ; C. rubella ; C. grandiflora ; Adaptation ; growth form parameters ; phenotypic and genotypic variability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth form parameters ofCapsella bursa-pastoris populations, including a wide range of different environments, have been analyzed from random block field and growth chamber experiments. Changes in one character are often correlated with changes in another. Of special interest are correlations detected with the onset of first flowering. Variation in each of the characters is clearly influenced by both phenotypic and genotypic components. However, genotype — environment interactions are also subject to variation. Therefore, the adaptive significance of a given parameter is not found to be constant over the entire geographical range of the genus. Alpine populations tend to shift from annual to biannual life cycles.
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  • 99
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    Plant systematics and evolution 153 (1986), S. 287-292 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Liliaceae ; Gagea ; New Species ; Flora of Iran ; Afghanistan ; Pakistan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Six new species are described:Gagea anonyma, G. Staintonii, G. siphonantha, G. Grey-Wilsonii, G. chloroneura. All belong to subgen.Platyspermum (Boiss.)Miscz.
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  • 100
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    Plant systematics and evolution 154 (1986), S. 1-10 
    ISSN: 1615-6110
    Keywords: Angiosperms ; Liliaceae ; Urginea maritima ; Pollination mechanisms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three co-existing pollination mechanisms are found inUrginea maritima: insect-, wind-, and self-pollination. The flowers exhibit a typical insect-pollination syndrome; they offer abundant exposed nectar as well as pollen. Out of the many different visitors only a few could be regarded as pollinators:Apis mellifera, Polistes gallicus, andVespa orientalis. Wind pollination also occurs and generally is responsible for self-pollination. It is argued that the development of extra wind-pollination accompanied by partial self-incompatibility is an adaptation to increase pollination in an unfavourable season (August–September), when insects are scarce.
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