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  • Menschliches Gewebe  (2)
  • Nicotiana  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 75 (1987), S. 26-29 
    ISSN: 1432-2242
    Keywords: Density gradient centrifugation ; Electric fusion ; Epidermis protoplasts ; Heterokaryocyte enrichment ; Mesophyll protoplasts ; Nicotiana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mesophyll protoplasts from Nicotiana glauca were fused with epidermal protoplasts from N. langsdorffii by an electric pulse. After the fusion products were centrifuged on stepwise density gradient centrifugation using Percoll and sea water, somatic hybrids were observed at 70%–80% in the fraction recovered from the intermediate specific gravity fraction between epidermis and mesophyll protoplasts. From offsprings of these somatic hybrids, teratomatous plants were regenerated. Since the difference of specific gravity between mesophyll and epidermis protoplasts is inherent, this procedure can be essentially applied to obtain somatic hybrids between any combination of plants. The significance of this study is discussed in relation to obtaining somatic hybrids between plant materials without any appropriate genetic markers.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1437-1596
    Keywords: Nicotine ; Cotinine ; Gas chromatography/mass spectrometry ; Human Tissue ; Distribution ; Smokers' level ; Nikotin ; Cotinin ; Gaschromatographie/Massenspektrometrie ; Menschliches Gewebe ; Verteilung ; Tabakraucher
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Zur gleichzeitigen Bestimmung von Nikotin und Cotinin in verschiedenen Körpergeweben wurde eine zuverlässige und sensitive Methode mittels der Kapillar-Gas-Chromatographie/Massenspektrometrie entwickelt. Nikotin und Cotinin wurden durch einen 3-stufigen Extraktionsvorgang mit Chinolin als internem Standard isoliert und die Quantifizierung mittels der single ion monitoring-Technik durchgeführt, wobei für Nikotin das Ion m/z 133, für Cotinin m/z 176 und für Chinolin m/z 129 verwendet wurde. Die Detektionsgrenze lag in allen Geweben für Nikotin bei 5 ng/g und für Cotinin bei 10 ng/g, die Kalibrierung erbrachte lineare Verhältnisse im Bereich von 5–1.200 ng/g für Nikotin und im Bereich von 10–1.500 ng/g für Cotinin. Die Genauigkeit und Präzision der Methode wurde an verschiedenen Körpergeweben ausreichend bewiesen. Die Verteilung der beiden Verbindungen in verschiedenen Geweben wurde in 10 Fällen bestimmt. Die festgestellten Nikotinspiegel lagen hierbei bei Konzentrationen, die bei üblichen Tabakrauchern gemessen werden. Hohe Nikotinspiegel wurden in Leber, Niere, Milz und Lunge, niedrige Konzentrationen im Fettgewebe festgestellt. Die Cotinin-Konzentration lag in der Leber am höchsten. Das Gewebe-Blut-Verteilungsverhältnis für Nikotin und Cotinin war im Skelettmuskelgewebe am konstantesten, wobei die Konzentrationen hier jeweils nahe an den Konzentrationen im Blut lagen. Der Skelettmuskel ist somit das geeignetste Gewebe für toxikologische Untersuchungen, wenn die Asservierung von Blut nicht möglich ist.
    Notes: Summary A reliable and sensitive method for the simultaneous determination of nicotine and cotinine concentrations in various human tissues was developed using capillary gas chromatography/mass spectrometry. Nicotine and cotinine were extracted using a 3-step solvent extraction procedure and quinoline as an internal standard. Quantification was carried out by single ion monitoring using ions of m/z 133 for nicotine, m/z 176 for cotinine and m/z 129 for quinoline. The lower limit of detection was 5 ng/g for nicotine and 10 ng/g for cotinine, in each tissue sample. The calibration curves of various tissues were linear in the concentration range from 5–1,200 ng/g for nicotine and 10–1,500 ng/g for cotinine. The accuracy and precision of this method were examined using human tissues and the results were satisfactory. The distribution of nicotine and cotinine was measured in tissues from 10 human autopsies. Nicotine was detected in every tissue examined at a level seen in habitual smokers. The nicotine concentration was high in the liver, kidney, spleen and lung, and low in adipose tissue. The cotinine level was highest in the liver. The tissue/blood concentration ratios of nicotine and cotinine were most stable in skeletal muscle, where the level of these drugs was close to that in whole blood. Skeletal muscle is, therefore, considered to be the most suitable tissue sample for toxicological examination, when acquisition of blood samples is not feasible.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1615-6102
    Keywords: Cell culture ; DNA content ; Mitochondrial DNA ; Mitochondrial genome ; Nicotiana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The molecular size of mitochondrial DNA (mtDNA) molecules and the number of copies of mtDNA per mitochondrion were evaluated from cultured cells of the tobacco BY-2 line derived fromNicotiana tabacum L. cv. Bright Yellow-2. To determine the DNA content per mitochondrion, protoplasts of cultured cells were stained with 4′,6-diamidino-2-phenylindole (DAPI), and the intensity of the fluorescence emitted from the mitochondrial nuclei (mt-nuclei) was measured with a video-intensified photon counting microscope system (VIM system). Each mitochondrion except for those undergoing a division contained one mt-nucleus. The most frequently measured size of the DNA in the mitochondria was between 120 and 200 kilobase pairs (kbp) throughout the course of culture of the tobacco cells. Mitochondria containing more than 200 kbp of DNA increased significantly in number 24 h after transfer of the cells into fresh medium but their number fell as the culture continued. Because division of mitochondria began soon after transfer of the cells into fresh medium and continued for 3 days, the change of the DNA content per mitochondrion during the culture must correspond to DNA synthesis of mitochondria in the course of mitochondrial division. By contrast, the analyses of products of digestion by restriction endonucleases indicated that the genome size of the mtDNA was at least 270 kbp. Electron microscopy revealed that mtDNAs were circular molecules and their length ranged from 1 to 35 μm, and 60% of them ranged from 7 to 11 μrn. These results indicate that the mitochondrial genome in tobacco cells consists of multiple species of mtDNA molecules, and mitochondria do not contain all the mtDNA species. Therefore, mitochondria are heterogeneous in mtDNA composition.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    International journal of legal medicine 104 (1991), S. 67-69 
    ISSN: 1437-1596
    Keywords: Triazolam ; Estazolam ; Capillary GC/NPD ; Human tissue ; Forensic toxicology ; Triazolam ; Estazolam ; Kapillar-Gaschromatographie/NPD ; Menschliches Gewebe ; Forensische Toxikologie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Eine zuverlässige und empfindliche Methode wurde entwickelt, um die Konzentrationen des hypnotischen Medikaments Triazolam in menschlichen Geweben, einschließlich fauler Gewebe bestimmen zu können. Die Methode besteht aus einer dreistufigen Flüssig-Flüssig-Extraktion, einem Clean up an Kieselgel und Gaschromatographie mit einem Stickstoff-PhosphorDetektor und einer Kapillarsäule. Als interner Standard wurde Estazolam benutzt. Die Eichkurve war im Konzentrationsbereich zwischen 1 ng/g und 1 gg/g linear, und die untere Nachweisgrenze betrug 0.5 ng/g. Es wurde eine forensische Untersuchung über die toxikologischen Effekte von Triazolam an faulem Gewebe durchgeführt.
    Notes: Summary A reliable and sensitive method has been developed to assess the concentrations of the hypnotic drug triazolam in human tissues, including putrefied tissues. The method involves a 3-step solvent extraction, cleanup on a silica gel column and gas chromatography using a nitrogen phosphorus detector and a capillary column. Estazolam was used as an internal standard. The calibration curve was linear over the concentration range 1 ng/g1 gm/g and the lower limit of detection was 0.5 ng/g. A forensic study was performed on the toxicological effects of triazolam using putrefied tissues.
    Type of Medium: Electronic Resource
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