Library

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1985-1989  (13,486)
  • 1960-1964  (4,739)
  • 1955-1959  (2,394)
  • General Chemistry  (12,211)
  • Analytical Chemistry and Spectroscopy  (5,836)
  • Engineering General  (2,473)
  • gene expression
  • gene transfer
Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 45 (1989), S. 526-535 
    ISSN: 1420-9071
    Keywords: Interferon ; cytokines ; interleukins ; gene expression ; transcription ; autoimmune ; disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Specific interferon genes are transcribed at low levels in the spleen, liver, and peripheral blood leukocytes of normal individuals in the apparent absence of virus infection while other interferon genes remain unexpressed in the same tissues. In contrast, the genes of cytokines such as IL-1, IL-6 and TNF are expressed at relatively high levels in the organs of normal individuals. The level of expression of the IL-1, IL-6 and TNF genes is markedly reduced in the livers of patients with autoimmune liver disease compared to the level of expression in the liver of normal individuals, whereas the expression of interferon genes is similar in both normal and diseased liver, suggesting that a defect in the expression of specific cytokines is associated with severe liver disease.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-4927
    Keywords: mouse ; salivary protein ; lacrimal protein ; gene expression ; Spt locus ; multigene family
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The murine submandibular gland (SMG) produces a novel class of highly acidic salivary proteins encoded by one or more highly abundant mRNA transcripts. In inbred mice, these transcripts are encoded by members of a multigene family comprising approximately 8–12 homologues. Most, and probably all, of these homologues are clustered at a new locus near belted (bt) on chromosome 15, which we designateSpt (salivary protein). Although physically closely linked,Spt genes differ in their patterns of expression both in strains of mice and in their tissues. One gene,Spt-1, is expressed at high levels in the SMG of all inbred strains examined. This gene is also expressed at significant levels in the lacrimal gland. A second gene,Spt-2, appears to be present as a single copy in some strains and as two copies in others. This gene is expressed at high levels only in the SMG of those strains carrying two copies, andSpt-2 mRNA is not detectable in the SMG of strains carrying only one copy. In contrast toSpt-1, theSpt-2 gene is not expressed at detectable levels in the lacrimal gland.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-4927
    Keywords: mouse ; salivary protein ; lacrimal protein ; gene expression ; Spt locus ; multigene family
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The murine submandibular gland (SMG) produces a novel class of highly acidic salivary proteins encoded by one or more highly abundant mRNA transcripts. In inbred mice, these transcripts are encoded by members of a multigene family comprising approximately 8–12 homologues. Most, and probably all, of these homologues are clustered at a new locus near belted (bt) on chromosome 15, which we designateSpt (salivary protein). Although physically closely linked,Spt genes differ in their patterns of expression both in strains of mice and in their tissues. One gene,Spt-1, is expressed at high levels in the SMG of all inbred strains examined. This gene is also expressed at significant levels in the lacrimal gland. A second gene,Spt-2, appears to be present as a single copy in some strains and as two copies in others. This gene is expressed at high levels only in the SMG of those strains carrying two copies, andSpt-2 mRNA is not detectable in the SMG of strains carrying only one copy. In contrast toSpt-1, theSpt-2 gene is not expressed at detectable levels in the lacrimal gland.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-4919
    Keywords: complement ; factor B ; gene expression ; interferon-ψ ; interleukin-1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The serine protease complement factor B (Bf), an acute phase plasma protein, is a component of the alternative pathway of complement activation. Previous studies revealed that several cytokines including IFN-γ and IL-1 are involved in mediating acute phase Bf expression. To determine the molecular details of Bf expression we isolated, sequenced and characterized the 5′ flanking regions of the human and murine Bf genes. In both species the Bf transcriptional start site in liver was located 〈400 by 3′ to the polyadenylation site of the upstream C2 gene. This upstream intergenic region contained 〉65% nucleotide homology between species. Within this region, an IRS and three heat shock consensus elements were found in the murine sequence in an identical position to that of the human. To examine the functional details of Bf expression, a series of mouse and human Bf promoter - chloramphenicol acetyltransferase (CAT) chimeric gene constructs were transfected into mouse L or human HepG2 cells. Analysis of expression of these fusion gene constructs revealed that 1) cis-acting DNA sequences identified, at least in part, in the 3′ untranslated region of the C2 gene (within the 400 by upstream of the Bf cap site) mediate responsiveness to IL-1 and IFN-γ, 2) the responsiveness to each mediator appears to be conferred by separate upstream regions similar in position and homologous in man and mouse, and 3) the IL-1 responsive region in both species appears to have the characteristics of an enhancer element. The results of this analysis suggest a selective pressure to conserve the intergenic sequence between C2 and Bf genes and that further studies of these sequences will be useful in elucidating mechanisms controlling the acute phase response.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-5028
    Keywords: differential cDNA screening ; gene expression ; hybrid-select in vitro translation ; nuclear run-off transcription ; RNA blot hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA library from cultured parsley (Petroselinum crispum) cells was differentially screened using labeled run-off transcripts derived from nucleic of elicitor-treated and untreated cells. This resulted in the isolation of 18 independent cDNA families representing putative defense-related genes. All genes are rapidly and transiently activated after elicitor application, but the time courses of transcriptional activity exhibit considerable variations, indicating differences in the mechanisms of gene regulation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Bioscience reports 9 (1989), S. 157-188 
    ISSN: 1573-4935
    Keywords: matrix hypothesis ; morphogenesis ; protodynamics ; growth control ; DNA ; genome organisation ; gene expression ; gene regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A theoretical concept is proposed, in order to explain some enigmatic aspects of cellular and molecular biology of eukaryotic organisms. Among these are the C-value paradox of DNA redundancy, the correlation of DNA content and cell size, the disruption of genes at DNA level, the “Chromosome field” data of Lima de Faria (Hereditas 93∶1, 1980), the “quantal mitosis” proposition of Holtzeret al. (Curr. Top. Dev. Biol. 7∶229 1972), the inheritance of morphological patterns, the relations of DNA and chromosome organisation to cellular structure and function, the molecular basis of speciation, etc. The basic proposition of the “Unified Matrix Hypothesis” is that the nuclear DNA has a direct morphogenic function, in addition to its coding function in protein synthesis. This additional genetic information is thought to be largely contained in the non-protein coding transcribed DNA, and in the untranscribed part of the genome.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-5028
    Keywords: acyl carrier protein ; fatty acid synthesis ; gene expression ; gene fusion ; protein A ; spinach
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A synthetic gene encoding spinach acyl carrier protein I (ACP-I) was fused to a gene encoding the Fc-binding portion of staphylococcal protein A. This gene fusion, under the control of the λPR promoter, was expressed at high levels in Escherichia coli producing a 42 kDa fusion protein. This fusion protein was phosphopantethenylated in E. coli. In vitro the ACP portion of the fusion protein was able to participate in acyl ACP synthetase reactions, plant malonyl-CoA:ACP transacylase (MCT) reactions, and plant fatty acid synthetase (FAS) reactions. Inhibitory effects of high ACP concentrations on in vitro plant FAS were observed with the unfused ACP-1 but not with the fusion protein. As with unfused ACP-I, the fusion protein was a poor substrate for E. coli FAS reactions. When injected into rabbits, the fusion protein was also able to generate antiserum to spinach ACP-I.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-5028
    Keywords: cDNA sequence ; gene expression ; glutamine synthetase ; legume-Rhizobium symbiosis ; nitrogen metabolism ; Phaseolus vulgaris L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report the sequence of an essentially full-length glutamine synthetase (GS) cDNA clone (pcGS-γ1) isolated from a root nodule library ofPhaseolus vulgaris L. The polypeptide encoded by this cDNA has been producedin vitro by transcription/translation and shown to co-migrate on two-dimensional gels with the previously identified major cytosolic GS polypeptide (γ) of nodules. Two previously identified GS cDNA clones, pR-2 and pR-1 (see Gebhardtet al., EMBO J 5: 1429–1435, 1986) have similarly been shown to encode the α and β cytosolic GS polypeptides respectively. An RNase protection technique has been used to analyse specifically and quantitatively the abundance of mRNA related to these three GS cDNAs and to the cDNA (pcGS-δ1) encoding the chloroplast-located GS, during nodulation. Differences in the abundances of these mRNAs at different times suggest that they are not coordinately regulated. Moreover, using this technique mRNA specifically related to pcGS-γ1 was found at high levels in nodules but not in roots or leaves. Surprisingly the expression of this gene is not nodule-specific as previously suggested, as its mRNA was also detected, but at lower levels, in stems, petioles and in green cotyledons. By comparison, mRNA related to a leghaemoglobin gene was detected only in nodules. Comparisons of the relative abundances of the pcGS-γ1 mRNA and the γ polypeptide in different organs and at different stages during nodulation, suggest that the appearance of the γ polypeptide is largely under transcriptional control.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-5028
    Keywords: antisense RNA ; β-glucuronidase ; tobacco ; transgenic plants ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Antisense RNA was used to specifically inhibit the expression of a GUS gene introduced in a transgenic plant. A tobacco transformant containing a single intact copy of the GUS gene and showing relatively high constitutive levels of GUS activity (GUS+) was re-transformed with an Agrobacterium Ti-derived binary vector containing an antisense version of this reporter gene. The sense and antisense GUS genes were each under the regulation of the CaMV 35S promoter. Re-transformed plants contained 1–5 copies of the antisense construct and all showed a greater than 90% reduction in GUS activity relative to the original GUS+ plant. This reduction in GUS activity correlated closely with the levels of GUS enzyme and steady state GUS mRNA observed in these plants. The relatively low levels of sense and antisense GUS transcripts found in the re-transformed plants may indicate a rapid degradation of the RNA:RNA duplex in the cell.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-5028
    Keywords: deformation factor ; gene expression ; pea ; Rhizobium leguminosarum ; root hairs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mRNA population in pea root hairs was characterized by means of in vitro translation of total root hair RNA followed by 2-dimensional gel electrophoresis of the translation products. Root hairs contain several mRNAs not detectable in total RNA preparations from roots. Most of these root hair-specific mRNAs occur in elongating root hairs at higher levels than in mature root hairs. The expression of some genes in pea root hairs is typically affected by inoculation with Rhizobium leguminosarum. One gene, encoding RH-42, is specifically induced while the expression of another gene, encoding RH-44, is markedly enhanced. Using R. leguminosarum mutants it was shown that the nodC gene is required for the induction and enhancement of expression of the RH-42 and RH-44 genes, respectively, while the Rhizobium chromosomal gene pss1, involved in exopolysaccharide synthesis, is not essential. After induction of the nod genes with apigenin the bacteria excrete into the culture medium a factor that causes root hair deformation. This deformation factor stimulates the expression of the RH-44 gene but does not induce the expression of the gene encoding RH-42.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 12 (1989), S. 295-299 
    ISSN: 1573-5028
    Keywords: gene expression ; multiple transcripts ; phytochrome ; Pisum sativum ; red/far-red reversible effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The reversible effect of red and far-red light on the level of two RNA transcripts of the single-copy phytochrome gene in pea was investigated using the primer extension assay. In dark-grown seedlings, a brief irradiation with red light markedly reduced the level of one of the phytochrome transcripts, RNA1. This red light effect was reversed by subsequent irradiation with far-red light. The other phytochrome transcript, RNA2, was only slightly influenced by light. In light-grown seedlings, a brief irradiation with far-red light increased the content of both RNA1 and RNA2 when the seedlings were transferred from light to darkness. This far-red light effect was reversible by subsequent red light irradiation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1573-5028
    Keywords: C4 photosynthesis ; gene structure ; gene expression ; genetic variation ; silent substitution ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have determined the structure of the maize (Zea mays L. subsp.mays line B73) nuclear gene encoding the phosphoenolpyruvate (PEP) carboxylase isozyme involved in C4 photosynthesis. The gene is 5.3 kb long and has ten exons that range in size from 85 to 999 bp. The nine introns vary from 97 to 872 bp. The sequence of 663 bp of 5′-flanking and 205 bp of 3′-flanking DNA is reported along with the entire gene sequence. Several short repetitive sequences were found in the 5′-flanking DNA that have characteristics similar to elements important in the light regulation of pea genes encoding the small subunit of ribulose 1,5-bisphosphate carboxylase. In addition, some 5′-flanking sequence similarities were found in a comparison with other light-regulated genes from maize and wheat. The level of DNA sequence variation among different PEP carboxylase alleles is similar to the allelic variation observed for several other maize nuclear genes. The data suggest modern maize variaties have retained much of the genetic variation present in their ancestral forms. Finally, accumulation of transcripts encoding the PEP carboxylase isozyme involved in C4 photosynthesis is quite high in several structures besides leaves, including inner leaf sheaths, tassels and husks. This indicates that expression of this gene is not leaf-specific and may not necessarily be coupled to the development of Kranz anatomy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 12 (1989), S. 673-682 
    ISSN: 1573-5028
    Keywords: amylase inhibitor ; barley ; cDNA sequence ; gene expression ; hormonal regulation ; protease inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have cloned and sequenced a full-length cDNA from barley (Hordeum vulgare L.) seeds encoding the bifunctional α-amylase/subtilisin inhibitor (BASI). The nucleotide sequence predicts an open reading frame coding for a protein of 203 amino acids. The first 22 amino acids exhibit the sequence characteristic of a signal peptide, as found in several other plant protease inhibitors. Northern blot hybridization experiments indicate that BASI mRNA accumulation is strictly tissue-specific and is developmentally programmed. BASI mRNA transcripts were only identified in 1) developing starchy endosperm tissue from 14 days after flowering and 2) aleurone tissue of germinating seeds. In this latter tissue, BASI mRNA accumulation is enhanced by abscisic acid and abolished by gibberellic acid. Expression of BASI mRNA was also studied in the lys 3a high-lysine barley mutants Risø No. 1508 and Piggy. These high-lysine barleys show 2–4-fold higher levels as well as prolonged accumulation of BASI mRNA compared to the normal motherline Bomi. This correlates with the increased deposition of BASI protein in lys 3a barley mutants. Genomic blot analysis of barley DNA suggests that there are one or two BASI structural genes per haploid genome. Possible roles of BASI as part of a defence mechanism against precocious germination and pathogens are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1573-5028
    Keywords: cadmium ; Datura innoxia ; gene expression ; heat shock ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of Cd on gene expression in suspension cultures of twoDatura innoxia cell lines with differing Cd tolerance was studied.In vivo labeling experiments using [3H] leucine showed that Cd induced the synthesis of a similar range of proteins in both cell lines at a concentration which will kill the sensitive but not the tolerant cells. Corresponding changes in levels of translatable mRNA were also observed. The induction of the synthesis of proteins by Cd was transient since Cd-tolerant cells growing continuously in 250 μM CdCl2 contained a similar set ofin vitro translation products to cells growing in the absence of Cd. Although Cd had a similar effect on gene expression in both cell lines, Cd-tolerant cells possess two abundant mRNAs which are constitutively produced. These mRNAs encode proteins of low molecular weight (about 11 kDa) and are either absent or present at a low level in Cd-sensitive cells. The functions of these proteins are not known but they may be involved in the tolerance mechanism. Two-dimensional gel electrophoresis ofin vitro translation products showed that many of the Cd-induced proteins are also induced by heat shock. A 42°C heat shock resulted in agreater range and more intense induction of translatable mRNAs than 4 h exposure to 250 μM CdCl2. However a subset of mRNAs were induced specifically by Cd while other mRNAs were heat shock-specific. There was no difference in the ability of the two cell lines to tolerate heat shock. This was also reflected by the same pattern of major proteins induced by heat shock in the two cell lines.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 12 (1989), S. 667-672 
    ISSN: 1573-5028
    Keywords: ferredoxin ; gene expression ; heterocyst ; Anabaena 7120 ; Escherichia coli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genes for ferredoxin from heterocysts (fdx H) and vegetative cells (pet F) of Anabaena sp. strain 7120 were subcloned into plasmid pUC 18/19. Both genes were expressed in Escherichia coli at high levels (≈10% of total protein). Pet F could be expressed from its own promoter. The ferredoxins were correctly assembled to the holoprotein. Heterocyst ferredoxin was purified from E. coli extracts on a large scale. Its biochemical and biophysical properties were identical to those of the authentic ferredoxin, isolated from Anabaena heterocysts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1573-5028
    Keywords: cDNA ; gene expression ; hydroxypyruvate reductase ; light regulation ; peroxisomal enzyme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A full-length cDNA encoding NADH-dependent hydroxypyruvate reductase (HPR), a photorespiratory enzyme localized in leaf peroxisomes, was isolated from a λgt11 cDNA library made by reverse transcription of poly(A)+ RNA from cucumber cotyledons. In vitro transcription and translation of this clone yielded a major polypeptide which was identical in size, 43 kDA, to the product of in vitro translation of cotyledonary poly(A)+ RNA and subsequent immunoprecipitation with HPR antiserum. Escherichia coli cultures transformed with a plasmid construct containing the cDNA insert were induced to express HPR enzyme activity. RNA blot analysis showed that HPR transcript levels rise significantly in the first eight days of light-grown seedling development. This closely resembles the pattern seen for HPR-specific translatable mRNA. DNA blot analysis indicated that a single HPR gene is likely present per haploid genome. Nucleotide sequence analysis revealed an open reading frame of 1146 bases which encodes a polypeptide with a calculated molecular weight of 41.7 kDa. The derived amino acid sequence from this open reading frame is 26% identical and 50% similar to the amino acid sequence of the E. coli enzyme phosphoglycerate dehydrogenase, which catalyzes a similar reaction and functions in a related pathway. Statistical analyses show that this similarity is significant (z〉10). The derived amino acid sequence for HPR also contains the characteristics of an NAD-binding domain.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Bulletin of experimental biology and medicine 108 (1989), S. 999-1001 
    ISSN: 1573-8221
    Keywords: brain ; gene expression ; mRNA ; transplantable hepatomas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular neurobiology 9 (1989), S. 281-294 
    ISSN: 1573-6830
    Keywords: cholecystokinin ; mammillary region ; development ; gene expression ; hybridization histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The ontogeny and adult distribution of neurons containing cholecystokinin (CCK) mRNA in the premammillary and mammillary nuclei and supramammillary region of the rat brain were studied using hybridization histochemistry. 2. The earliest detection of CCK mRNA in the mammillary region was on E14, followed by a marked increase in transcript levels during the next 4 days, a time during which neurons in this region still divide. During the first 2 weeks of life, few changes in the levels of CCK transcripts were seen, and an adult-like pattern of expression was seen on the twenty-first day of life. 3. Low levels of transcripts were present in numerous neurons located in all divisions of the medial nucleus and in the posterior nucleus known to project ipsilaterally to the anteroventral and anteromedial thalamic nuclei. In contrast, none of the neurons in the lateral nucleus (projecting bilaterally to the anterodorsal thalamic nucleus) had detectable transcripts. 4. Many neurons in the supramammillary nucleus had low, moderate, or high levels of transcripts. Some nearby nuclei (such as the dorsal premammillary nucleus) had smaller numbers of neurons with low levels of CCK mRNA, whereas others (such as the ventral premammillary nucleus) had none.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Fish physiology and biochemistry 7 (1989), S. 409-413 
    ISSN: 1573-5168
    Keywords: gene transfer ; transgenic fish ; growth hormone ; antifreeze polypeptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Successful production of transgenic fish by gene transfer technology is a very important breakthrough in the techniques of genetic manipulation in animals. This will have an impact of an unprecedented scale in fish biology, aquaculture and mariculture. This is a summary of the workshop on the Transgenic Fish presented at this Symposium. The Workshop discussed the current knowledge, experimental difficulties and related topics of the transgenic fish. It recommended further research on better gene constructs, methods development, safety containment and the closer collaboration of researchers of different disciplines.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1573-0603
    Keywords: Agrobacterium ; gene transfer ; somatic embryos ; walnut ; β-glucuronidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Somatic embryos have been successfully used as a target tissue for transformation and regeneration of transgenic walnut plants. Walnut somatic embryos, initiated originally from developing zygotic embryos, proliferate numerous secondary embryos from single cells in the epidermal layer. These single cells in intact somatic embryos are susceptible to transformation by genetically engineeredAgrobacterium tumefaciens and provide a means to regenerate nonchimeric transgenic plants. This gene transfer system has been made more efficient using, a) vector plasmids containing two marker genes encoding β-glucuronidase (GUS) and aminoglycoside phosphotransferase (APH(3′)II) and B) a more virulent strain ofAgrobacterium. This system should be applicable to any crop that undergoes repetitive embryogenesis from singleAgrobacterium-susceptible cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 21
    ISSN: 1572-994X
    Keywords: BAL31 nuclease ; CAT assay ; gene expression ; HTLV-I ; R region ; 5′ untranslated sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We previously demonstrated the activity of the R fragment in the long terminal repeat of human T-cell leukemia virus type I for elevation of the level of gene expression. In this study, the fragment was deleted with BAL31 nuclease to determine its functional domain. Series of the shortened R fragments were linked to the simian virus 40 promoter unit, which regulated expression of a reporter gene. Examination with the R fragments deleted from the 5′ and 3′ ends showed that borders of the functional domain were mapped within nucleotide positions 458 to 473 for the 5′ end and nucleotide positions 559 to 594 for the 3′ end, respectively. Thus we conclude that a 136-base-pair fragment corresponding to the second half of the R region was sufficient to allow elevation of the level of gene expression.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 46-47 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Different metal salts have been tried as impregnating reagents for developing TLC separation schemes for some antihistamines on silica gel ‘G’ plates, using a new solvent system benzene + dimethyl formamide + acetic acid (30:10:7). Spots were visualized by spraying with a solution of Dragendroff's reagent.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. i 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 10-13 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simplified method for the preparation of wheat germ agglutinin(WGA)-Sepharose 4B by coupling highly purified WGA, prepared by improved affinity chromatography, with BrCN activated Sepharose 4B in a solution of high carbonate buffer is described. The amount of WGA linked to Sepharose 4B was 82.40% (3.07 mg WGA per ml Sepharose 4B). MN blood group antigens of human erythrocyte membranes purified with WGA-Sepharose 4B affinity chromatography showed a single band on sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS/PAGE). The yield of the antigens from 400 mL fresh blood was 32-40 mg. The WGA-Sepharose 4B column could be used several times without loss of activity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 32-34 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A method for the unambiguous characterization of DNA photoproducts has been developed. It does not require radio-labelled DNA, or specialized techniques. In the preliminary step, UV-irradiated DNA is hydrolysed to its constituent bases and photoproducts. The photoproducts are then separated from nucleic acid bases using low pressure ion-exchange chromatography on a Dowex 1 × 8 200-400, and an Amberlite CG-50-H+ column. Further separation and purification of photoproducts is carried out on the HPLC Whatman Partisil ODS2 column, using 15% MeOH. The procedure is simple, reproducible and versatile.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 43-45 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Two new solvent systems, n-hexane + propionic acid (26:5, v/v) and chloroform + acetone (29:3, v/v), for the rapid resolution and identification of an 18-component mixture of phenylthiohydantoin amino acids are reported. Using these systems certain difficult combinations of phenylthiohydantoin amino acids are resolved. Two more solvent systems, viz chloroform+acetic acid (27:3, v/v) and chloroform + methanol (30:4, v/v), are developed to resolve phenylthiodantoin derivatives of aspartic and glutamic acids.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. i 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 49-52 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple rapid method for simultaneous ethosuximide and phenobarbital assay in brain tissue, serum and urine has been developed. Extraction of samples from brain tissue and serum were performed with dichloromethane at low pH in the presence of an excess of ammonium sulfate. Glucuronide conjugates in urine samples were hydrolyzed by enzymatic cleavage with β-glucuronidase and then extracted with dichloromethane. The extracts were analyzed using a Spherisorb 5 ODS column and a mixture of acetonitrile, methanol and phosphate buffer (21: 24: 55, v/v) as eluent. No interference was encountered and the method is both precise and reproducible.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 136-138 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A high performance liquid chromatographic (HPLC) method for the determination of the anticoccidial and antitheilerial drug halofuginone in bovine plasma was developed. Samples were diluted with acetic acid (10%, v/v) and cleaned up on a Bond Elut C8 column. The analyte was eluted from the extraction column and chromatographed by reversed-phase HPLC using decylamine as a competing-ion reagent. Detection was by UV at 243 nm. Recovery from plasma was 75%, and within-day and between-day coefficients of variation were 5.23 and 6.35% respectively. The specificity and sensitivity of this method (limit of detection in plasma, 1 ng/mL) were sufficiently high to enable us to characterize the time course of the drug in plasma after oral administration of therapeutic doses to cattle.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989) 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 31
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A new method based on displacement electrophoresis has been developed for the determination of the total and free concentration of propranolol, a β-adrenergic blocker drug, in plasma. To determine the total concentration the drug is extracted from human plasma into a chloroform + heptane mixture in the presence of ammonia. After evaporation of the solvent mixture the residue is submitted to displacement electrophoresis in a glass tube containing a two-layer polyacrylamide gel. When the propranolol electrophoretically leaves the gel column it is transferred by a buffer flow to the cuvette of a fluorimeter for continuous detection and quantification. The concentration of the free non-protein bound drug can be determined by the same displacement electrophoresis technique following extraction of the plasma sample into the above organic solvent mixture in the absence of ammonia. Alternatively the extraction procedure can be exchanged for dialysis for 1 h. To decrease the risk that large size material might comigrate with propranolol two layers of polyacrylamide are used, one having small pores to retard such material. In addition, we use fluorimetric detection which means that many possible contaminants are not recorded and therefore do not affect a quantitative determination of propranolol.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 255-261 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Analyses of estrogen and progesterone receptors in biopsies of breast carcinoma play a vital role in the selection of patients likely to respond to hormone manipulation. Sucrose density gradient centrifugation has been the reference method in the determination of estrogen receptors in human breast carcinoma cytosols. To reduce assay time and circumvent prolonged manipulation of labile receptor preparations, high performance liquid chromatography techniques in the size-exclusion and ion-exchange modes were compared as potential alternate methods for the rapid separation of receptor isoforms. Multidimensional analyses were performed by reapplying estrogen receptor isoforms obtained from high performance size-exclusion and ion-exchange chromatography to sucrose density gradients and vice versa. This confirmed that the estrogen-binding components identified by high performance liquid chromatography appear to correspond to estrogen receptor species from sucrose density gradients.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 269-271 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A sensitive (2 ng/mL) and specific method for the determination of the benzodiazepine antagonist Ro 15-1788 or flumazenil is described. Following a simple extraction, the compound is analyzed by reversed phase high performance liquid chromatography (HPLC) and detection at 245 nm. The method was applied to plasma specimens collected from patients receiving a single dose of this drug.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 34
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple and precise method for the quantitation of epomediol in human plasma and urine is described. Each biological sample is added with the internal standard and applied directly to an Extrelut-1 solid-phase column. After absorption the column is eluted with chloroform and the eluate is evaporated to dryness. The residue, reconstituted in ethanol, is analysed by capillary gas chromatography. No interferences from possible metabolites or endogenous constituents can be noted. The method has been applied to human pharmacokinetic studies: the results of a subacute administration to volunteers are presented.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Malonyl-CoA is a biochemically important compound, formed by an acetyl-coenzyme A carboxylase catalysed reaction. The stability of this short-chain coenzyme A derivative under various experimental conditions is discussed in this article. High-performance liquid chromatography was used for the analysis of the reaction mixture because of its excellent selectivity and sufficient sensitivity. Several variables were investigated as possible stability-influencing factors: pH, magnesium and buffer concentration, reaction temperature and time. The Plackett-Burman screening design was first used for selecting the most important variables, with which a central composite design was constructed. In this way, a response surface was obtained with the percentage remaining malonyl-CoA as a function of magnesium concentration, reaction temperature and time. The usefulness of this approach is demonstrated by obtaining kinetic data from the mathematical function and by the evaluation of the stopping of reaction procedure in the activity assay of acetyl-coenzyme A carboxylase.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 221-225 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Rabbit kidney (RK-13) and human jejunum and ileum (I-407) cells infected with herpes simplex virus type 1, strain F, were radiolabelled with [14C]glucosamine or [35S]methionine for 24 h. The cells were extracted with 1% Triton X-100 and the extracts were separated by gel filtration high performance liquid chromatography. Monoclonal antibody immunoprecipitation of the fractions collected from the column revealed a monomeric glycoprotein D (gD) of 52 - 56 000 molecular weight from RK-13 cells and two monomeric forms of gD, 54 000 and 58 000 molecular weight, from I-407 cells. Densitometry scanning of the autoradiograms from SDS-PAGE showed gD from the RK-13 host cells to be 98.7% pure with the [35S]methionine label and 97.0% pure with the [14C]glucosamine. On the other hand, gD from the I-407 host cells was only 78.6% with the [35S]methionine label and 96% pure with the [14C]glucosamine. This method could provide a means for the isolation of native gD for structural and immunological studies.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 233-240 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The dinitrophenyl (DNP) derivatives of amino acids have found continual application in protein sequencing since Sanger used them for the first time for the sequencing of insulin. Dansyl derivatives of amino acids have been widely used in protein sequencing because of their fluorescent nature. The success of protein sequencing largely depends upon correct identification of such derivatives. The choice for the method of identification is related to cost, the availability of instrumentation and to the sensitivity needed for the analysis. Thin layer chromatography (TLC) is simple and has several advantages over other chromatographic methods. Therefore the literature after 1972 is reviewed for TLC analysis of dansyl- and DNP-amino acids, the two important amino acid derivatives required for identifying protein sequences. Additionally, the literature on the TLC resolution of enantiomeric mixtures of dansyl amino acids is reviewed. Application of various adsorbents, composition of solvent systems and other experimental conditions together with successful resolution data have been discussed. TLC provides a direct and inexpensive method for the resolution of enantiomers, and is fast becoming a sensitive instrumentalized quantitative analytical technique.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 272-273 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An HPLC method for the simultaneous detection of six organophosphorus pesticides (Dimethoate, Ethion, Malathion, Phorate, Phosalone and Parathion) on a Zorbex ODS column using methanol + water (80: 20) as solvent is described.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 39
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A novel analytical method for biological polyamines (putrescine, spermidine and spermine) was developed. Polyamines were separated by ion-pair reversed phase chromatography using a polymer-based octadecyl bonded column. A polyamine oxidase immobilized column worked effectively as a post-column reactor to convert polyamines to hydrogen peroxide which was eventually detected by electrochemical oxidation on platinum electrode. This method required neither tedious derivatization nor gradient elution, permitting us to perform simple and rapid analysis of polyamines. The detection limits were 0.3, 0.6, and 4 pmol injected for putrescine, spermidine, and spermine, respectively with a linear range of two to three orders of magnitude. Chromatograms obtained with samples from human urine and rat brain homogenates demonstrated the high sensitivity and selectivity of the method.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 276-278 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Highly purified monomeric human plasma lecithin:cholesterol acyltransferase (LCAT), completely free of apolipoprotein D, has been chromatographed on a MonoQ HR 5/5 anion exchanger. LCAT eluted as symmetrical peaks after 12.8 min and 14.8 min at pH 5.0 and pH 6.0, respectively, using a linear NaCl gradient. The corresponding concentrations of NaCI effecting desorption of LCAT from the anion exchanger were 125 mM and 175 mM. At both pH values human serum albumin eluted earlier and was well separated from the enzyme. Rechromatography of LCAT in the eluates from these experiments at acid pH, on high performance gel filtration, demonstrated absence of aggregation. The nonspecific adsorption during anion exchange chromatography at pH 5.0 and pH 6.0 was negligible, as demonstrated by a linear relationship between injected amounts of LCAT and recorded peak areas for a 2-20 μg protein range. Zone immunoelectrophoresis assay indicated unaltered immunoreactivity of the eluted LCAT.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 41
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The chromatographic behaviour of the membrane-attached variant surface glycoprotein (mfVSG) of bloodstream forms of Trypanosoma brucei brucei AnTat 1.1 A preparations were studied by reversed phase high performance liquid chromatography (RP-HPLC). Among the different preparation procedures used, only the trifluoroacetic acid extraction gave a mfVSG preparation which was eluted from the RP-HPLC column. As well as for the soluble variant surface glycoprotein (sVSG) it was found that different mfVSG forms were eluted at different organic solvent concentrations from the RP-HPLC column. In addition, in preliminary studies, we have attempted to characterize the factors responsible for the trypanosome surface coat assembly. Using chromatographic techniques (RP-HPLC and thin layer chromatography), the results suggest a close relationship between the content of lipid-containing species and the heterogeneity of mfVSG preparation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989) 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. ii 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. iii 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 153-156 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An automated column-switching HPLC system is described for the simultaneous determination of midodrine, an alpha-adrenergic stimulating drug, and its active metabolite, ST-1059. Serum or plasma (850 μ L) is directly injected onto a RP 18 (30 μm particle size) pre-column (9 × 4 mm ID) which acts as an on-line liquid-solid extractor and analyte enrichment system. The injection is followed by washing steps. The fraction containing the analytes is transferred onto an analytical RP18 column via step gradient elution where the final analysis is performed. Fluorescence detection is used (λex 290 nm and λem 322 nm), and method detection limits of 0.8 ng/mL plasma were reached. These were sufficiently low to determine the plasma concentration-time profiles for both compounds following oral administration of 2.5 mg and 5 mg midodrine hydrochloride. The assay in serum or plasma was linear in the range of 1 to 15 ng analyte/mL, the recovery was 〉95%, and the reproducibility was sufficient. The assay was rugged and was maintained by routinely changing the home-made, dry packed pre-column every 20th serum injection.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 177-179 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A method has been developed for the separation and measurement of fluvoxamine in human plasma by high performance liquid chromatography. The method uses metapramine as an internal standard and provides a limit of detection of about 1.5 ng/mL for fluvoxamine. At a concentration of 25 ng/mL, fluvoxamine could be measured within a coefficient of variation of ±5.82 of the mean and at 100 ng/mL within a CV of ±2.78 of the mean. The method has been applied to the analysis of plasma from patients undergoing fluvoxamine therapy.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Conditions for unblocking reversible chemical modifications such as maleylation or citraconylation ‘in situ’ at the N-terminus of proteins after transfer of proteins to immobilon membranes from SDS-PAGE are described. Demaleylation or decitraconylation occurred at 55°C in 70% formic acid (pH 1.50) during 60 min. During the unblocking reaction, Coomassie blue dye was completely removed, resulting in superior high performance liquid chromatographic separation of phenylthiohydantoin-amino acid (PTH-AA) after Edman degradation (automatic gas phase sequencer). The protein fixed on the matrix after demaleylation and removal of Coomassie blue was not degraded. The possible cleavage at the aspartyl-prolyl peptide bonds was considered, but no side reaction was observed. Furthermore, the incubation time in 70% formic acid at 55°C could be reduced to 10 min in the absence of maleylation of the starting material, and this was suitable for the removal of Coomassie blue and the quantification of phenylthiolhydantoin-amino acids (PTH-AAs) by HPLC. The yield from the starting protein through SDS-PAGE, blotting, and Edman degradation to quantitative analysis of PTH-aminoacid(s) by HLPC was established.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 48
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989) 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 192-195 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An HPLC method with direct sample injections and column switching was investigated for the analysis of drugs in tissue homogenates. The appropriate precolumn packings and analytical column packings were surveyed in order to obtain quantitative recovery. The use of a large bore end-fitting filter for the precolumn avoided the interference due to minute tissue particles. A minicolumn was used to trap the analyte or clean up the sample. The method was applicable to hydrophilic as well as hydrophobic drugs in liver, kidney or heart tissues, and has been extensively used in the determination of drugs in centrifugal cell fractions such as the nucleus, mitochondria and microsome.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 196-198 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A quantitative method for the determination of estriol (E3) and creatinine (C) in random urine by high performance liquid chromatography is described. The mobile phase was a mixed solution of methanol and phosphate buffer (0.025 M, pH 6.5) and the detection wavelength was at 205 nm. The method was simple, rapid and accurate. The OCV for E3 and C using this method were 1.7 - 3.4% and 2.2 - 2.5%, respectively. The RCV for E3 and C were 6.2 - 7.0% and 4.5 - 6.9%, respectively. The recoveries were 87 - 104% for E3 and 98 - 103% for C, respectively. The method has been used for clinical determinations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Different strategies for HPLC separation, including molecular sieving, ion-exchange, and hydrophobic interaction as well as reversed phase chromatography, were used to study molecular components in human cerebrospinal fluid (CSF). The separations were followed by photodiode-array UV detection, which is a recently developed technique allowing a direct and rapid discrimination between peptides and proteins differing in their content of aromatic amino acids. By the various HPLC techniques in conjunction with diode-array detection it was possible to identify and characterize several protein and peptide components present in CSF. The procedure also allowed quantitative analysis of CSF proteins using minute amounts of the fluid.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 53
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A newly developed method for the simultaneous extraction and quantitation of the unconjugated levels of the catecholamine metabolites vanilmandelic acid (VMA), 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and homovanillic acid (HVA) in plasma by high performance liquid chromatography with electrochemical detection was modified and applied to studies of human saliva. The assay had a mean coefficient of variation under 3% for each of the metabolites. Levels of plasma VMA, MHPG and HVA were measured in 28 normal subjects and compared to their saliva levels, obtained before and after stimulation by mastication. Significant correlations were found between plasma and saliva MHPG and HVA, but there was no correlation between plasma and saliva VMA. Salivary MHPG and HVA can be reproducibly assayed and may be useful tools for indications of changes in central and peripheral catecholamine metabolism.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 5-9 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A sensitive liquid chromatography method has been developed using electrochemistry for the determination of leukotrienes in biological fluids. Biological specimens are treated with 3,5-dinitrobenzoyl chloride in acetonitrile which undergoes rapid reaction with hydroxyl groups of non-peptidic leukotrienes in the presence of pyridine and with amino groups of peptidic leukotrienes in the presence of potassium tetraborate buffer. The resulting dinitroben-zoate derivatives of leukotrienes are highly electroactive, suitable for reduction or oxidation at moderate potentials by an electrochemical detector. In reductive mode at -0.7 V or oxidative mode at + 1.15 V potentials, the lower limits of detection for leukotriene derivatives were approximately 8±3 pg and 70 ± 16 pg respectively, with a signal-to-noise ratio of 5 to 1. This method was applied to the detection of leukotrienes in plasma, nasal and bronchial fluids of patients with asthma.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A new capillary GC method is described for the compositional analysis of the three main gangliosides isolated from adult human myometrium. The sample was subjected to methanolysis, acetylation and trimethylsilylation which allows all the constituents to be analyzed simultaneously. The predominant ganglioside was found to be GD3, with GM3 and GT1b the next most abundant.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 56
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A gas chromatographic-mass spectrometric (GC/MS) method for analysis of Δ1-tetrahydrocannabinol (Δ1-THC) in human fat samples is described. The fat sample, obtained from heavy marihuana users 1 week before and 4 weeks after smoking, is homogenized in hexane + 2-propanol, centrifuged, and the supernatant mixed with Lipidex 5000. The solvent is evaporated and the dried gel is packed in a glass column. Δ1 -THC is eluted from the column with methanol + water + acetic acid, diluted with water and the eluent is passed through a bed of Octadecylsilanebonded silica. After washing and drying, the retained Δ1-THC is eluted with hexane, derivatized with N-methyl-N-(t-butyl-dimethysilyl)trifluoroacetamide (MTBSTFA) and finally purified by HPLC on an Octadecyl SI 100 column in methanol. The amount of Δ1-THC is determined by GC/MS, using selected ion monitoring, and a deuterated internal standard. The recovery of Δ1-THC is about 80%, and the concentration of Δ1-THC in the fat samples analysed ranged between 0.4 and 193 ng/g wet tissue.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 57
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The peroxyoxalate chemiluminescence detection of biological thiols combined with high-performance liquid chromatography (HPLC) is described. SH groups of the thiol compounds including glutathione (GSH), cysteine, N-acetylcysteine, cysteamine, and D-penicillamine were labelled with N-[4-(6-dimethylamino-2-benzofuranyl)phenyl]maleimide (DBPM), a specific fluorogenic reagent for SH group. The labelling reaction was carried out at 60°C for 30 min and at pH 8.5 and a sample of the resulting reaction mixture was subjected to HPLC. Five kinds of labelled thiols were separated within 12 min on ODS-80 column (150 × 4.6mm ID; 5 μm) and detected in the ranges from 500 fmol to 2 pmol/100 μL (cysteamine and N-acetylcysteine), to 3 pmol/100 μL (cysteine) and to 5 pmol/100 μL (GSH and D-penicillamine). The lower detection limits were from 7 fmol (cysteamine) to 113 fmol (GSH) per 100 μL (S/N = 2). The method was applied to the determination of thiols in a rat liver. The amounts of glutathione and cysteine were 1.23±0.15 μmol/g (n = 5) and 0.15±0.04 μmol/g (n = 5), respectively.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989) 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A rapid assay employing HPLC with electrochemical detection for catechol-O-methyltransferase (COMT) activity in red blood cells is described. Enzyme activity is determined from erythrocyte lysates using S-adenosyl-L-methionine as methyl donor and 3,4-dihydroxybenzoic acid as substrate. The 3-O- and 4-O-methylated reaction products are measured by high-performance liquid chromatography with electrochemical detection. Human erythrocyte soluble form of COMT had Km values of 6.1 μM and 26.0 μM for S-adenosyl-L-methionine and dihydroxybenzoic acid, respectively. The mean O-methylation ratio for the soluble form of COMT was 5.3. An O-methylation ratio of 15.5 was estimated in the membrane fraction of an erythrocyte pool from three samples. The activities of soluble COMT in erythrocytes of some animal species are also reported. The procedure is easily automated, and a large number of samples can be processed during one working day.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 72-74 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A reversed-phase HPLC system with 88% methanol in 1 M ammonium acetate buffer pH 5.35 as the mobile phase on an ODS column was used to analyse pheophorbides a, a', b, b' and pyropheophorbides a and b. Pyropheophorbides a and b were found in samples obtained from silkworm excrement but not from spinach leaves though the preparation methods used were the same. This difference suggests that chlorophylls undergo metabolism in the body of silkworm to give pyrochlorophyll derivatives.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 82-87 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Hormone-sensitive lipase (HSL), the enzyme controlling the rate of adipose tissue lipolysis and also possibly involved in the regulation of steroidogenesis, has been purified from bovine omental adipose tissue. Partially detergent-solubilized, delipidated and purified HSL was obtained through step-elution at conventional DEAE ion-exchange chromatography, followed by concentration on hydroxylapatite. High performance hydrophobic interaction chromatography (HPHIC) on phenylsilica then resulted in an increase of HSL protein purity from 2% to more than 70%. Final purification of the enzyme to apparent homogeneity (〉95% protein purity), concentration and removal of most of the detergent was obtained by high performance cation exchange chromatography on Mono S. At least 0.5 mg of highly stable HSL was obtained from 5 kg of bovine omental fat within four working days. The purified lipase had a lower specific activity than previously reported for the corresponding rat enzyme but the preparations have proved very useful for enzyme structure studies and as an antigen.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. i 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 95-104 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 64
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Fluorescein isothiocyanate (FITC)-labelled asialotransferrin and pyridyl aminated oligosaccharides were prepared from asialotransferrin and human milk using affinity chromatography and high performance liquid chromatography (HPLC), respectively. These substances were incubated with galactosidase or sialyltransferase and then examined by lectin affinity HPLC. The elution patterns changed according to the period of incubation and amount of enzyme. This analytical method using lectin affinity HPLC with fluorescence labelled glycoprotein or oligosaccharides as the substrates has great value for detecting these enzyme under the same chromatographic conditions. In addition, differences were noted in the activity of β-galactosidase toward oligosaccharides having the Gal β(1 → 3)GlcNAc or Gal β(1 → 4)GlcNAc structure at reducing termini.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 65
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The isolation and properties of lactoferrin from human breast milk and from neutrophilic granulocytes were investigated. Human breast milk lactoferrin was purified by means of heparin-sepharose or Cibacron Blue affinity chromatography. Quantitative recovery using these two methods was comparable but Cibacron Blue affinity chromatography allowed for isolation of a more homogenous protein. Lactoferrin could only be isolated from human neutrophilic granulocytes by sequential use of antibody affinity followed by non-specific affinity chromatography. Both breast milk lactoferrin and granulocyte lactoferrin were separated into apo and iron-rich species by SDS polyacrylamide gel chromatography. Iron binding is accompanied by a conformational change in tertiary structure associated with more rapid electrophoretic migration. The isoelectric point of both human breast milk lactoferrin and human granulocyte lactoferrin is 5.5 - 6.2. Both types of lactoferrin have similar iron binding properties with release of iron from the one binding site occurring at pH 5.2 - 6.0 while the other binding site holds on to iron down to pH 3.6 - 3.2. Despite the high affinity for iron the percentage saturation of native lactoferrin is low, that for breast milk lactoferrin averaging 12 - 25% and that for granulocyte lactoferrin 〈 10%.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 66
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Human trypsin inhibitor (home prepared), lactalbumin, trypsinogen, carbonic anhydrase, and bovine serum albumin were submitted to succinylation and their molecular masses were determined by SDS-PAGE according to the method of Weber and Osborn (1969 J. Biol. Chem. 244, 4406) before and after chemical modification. High estimates of their molecular masses were obtained. The monomer and dimer of arrowhead inhibitor proteinase-B (Chinese vegetable legume) obtained after chemical crosslink(s) were also submitted to SDS-PAGE and their apparent molecular masses were also determined and compared to the native arrowhead inhibitor proteinase-B. Abnormally high estimates of their molecular masses were obtained. Our results agree with those in the literature.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989) 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 114-117 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A HPLC method for the quantitative determination of 5-hydroxy-3-indoleacetic acid (5-HIAA) in urine is described. The method is based on ion-pair chromatography, reversed phase (RP) column material and specific fluorimetric detection at 300 nm and 355 nm. Sample preparation and gradient elution were avoided by using a column-switching technique. The sensitivity of the assay was excellent for clinical routine analysis, with a detection limit of 0.2 mg/L 5-HIAA. No endogenous or exogenous interference problems arose. Intra- and interassay precision was good, with observed coefficients of variation of 1.5 to 2.6% and 2.1%, respectively. Recoveries were 93 to 98%. The system described can be used for clinical diagnosis and therapy follow-up of carcinoid tumors. It has been running for over a year without disturbances and with a minimum of technical attendance.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 127-130 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The soluble form of catechol-O-methyltransferase (EC 2.1.1.6.) from rat liver was purified to homogeneity by high-performance anion-exchange chromatography and high-performance gel-filtration chromatography. The specific activity of the final pool was 270 U/mg protein. The purification was 1180-fold and recovery of the enzyme activity was 15%. During this rapid and gentle purification there were no problems with loss of activity, and the estimated half life of the final purified enzyme pool was 5.5 days at +4°C. The only additive used was phenylmethylsulfonylfluoride in the homogenizing buffer.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 70
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Analytical conditions of prepurification extraction and HPLC separation were optimized for determination of urinary serotonin and tryptamine. Under optimal conditions, serotonin, tryptamine and an internal standard were extracted with 15% v/v n-propanol in diethyl ether from urine samples alkalized with a phosphate buffer (0.75 mol/L, pH 10.0), and then they were re-extracted into an HCI solution (0.1 mol/L). Purified indoleamines were simultaneously separated by reversed-phase ion-pair HPLC with native fluorescence detection. Urinary serotonin and tryptamine were selectively determined within about 45 min per sample for the whole procedure. Analytical recovery, reproducibility and detection sensitivity were satisfactory for pursuing time-dependent changes in indoleamine levels. Urinary excretion profiles of serotonin and tryptamine in subjects dosed with L-tryptophan were successfully analyzed by our method.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989) 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 241-245 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A practical procedure for isolating and purifying glycopeptides is described, viz. enzymatic hydrolysis - gel permeation chromatography - ion exchange chromatography - reversed phase HPLC. Using this procedure 28 glycopeptides from hen ovalbumin have been isolated some of which hitherto have not been identified. Water was a suitable mobile phase for preparing pure glycopeptides, and control of column temperature was important for good separations and reproducible retention times. Structural confirmation was by fast atom bombardment mass spectrometry.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A method is described to isolate rapidly human hemoglobin-benzo[a]pyrene diol epoxide adducts. A combination of 300 Å pore size C4 reversed phase HPLC to effect separation of adducted protein from native protein, and μ-bore C18 reversed phase HPLC to isolate and partially characterize proteolytic peptide adducts (by UV), was used.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 74
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple, accurate and precise procedure for the quantitation of itazigrel (a potent lipophilic inhibitor of collagen and arachidonic acid-induced aggregation being studied for its effects on peripheral vascular disease) from granulated rodent diet is presented. The drug was extracted from rodent diet using methanol + water (80:20) following dissolution of the diet in water. Samples of the supernatant were injected into the HPLC and the eluent was monitored with a fluorescent detector (λex = 320 and λem = 430) to achieve analytical specificity. Interday coefficients of variation of the calibration curve slope were ±6% on standards between 0 and 1000 μg/g. Potency and homogeneity of the drug spiked diet prepared over a 1 year interval at 70,200 and 600 μg/g was 99.3 ± 2.5%, 100 ± 1.8%, and 101 ± 1.9% of label, respectively. Samples prepared for chromatography were stable for 24 h at 20°C, and drug in diet was stable for 102 days when protected from light and stored at 20°C.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. i 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 183-185 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The release and content of the excitatory amino acid neurotransmitters glutamate and aspartate in rat striatum were determined by liquid chromatography/electrochemistry. This determination was based on precolumn off-line derivatization of the amino acids with o-phthaldialdehyde and 2-mercaptoethanol (OPT/2-MCE), and the adducts formed were separated under isocratic conditions and oxidized on a glassy carbon electrode at moderate potential (+0.6 V). The standard and the extracted glutamate when derivatized with OPT/2-MCE produced similar electrochemical and chromatographic characteristics. The detection limit of glutamate was 0.5 pmol. Depolarization induced by the high potassium medium (40 mmol/L) enhanced the release of glutamate and aspartate from superfused rat striatum, whereas the efflux of glutamine remained unchanged. Perfusion (for 60 - 70 min) removed 50 - 80% of the free amino acid content of striatal tissue. The method described here is useful in neurochemical investigations of the brain amino acid neurotransmitters.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 209-212 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A method for the determination of cyanide in human urine has been developed. The method is based on the reaction of cyanide with 2,3-naphthalenedialdehyde and taurine to give a fluorescent product for reversed-phase HPLC separation and fluorometric detection. After centrifugation followed by dilution of urine samples, the specimens could be analysed directly by this method. The recovery of cyanide added to urine at concentration levels of 50 - 1000 pmol/mL was 85 - 96%. The detection limit of cyanide was 30 pmol/mL in urine. The method was successfully applied to the analysis of urine from smokers and nonsmokers. The mean concentrations of cyanide were found to be 215 pmol/mL for the former and 84 pmol/mL for the latter.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. i 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 226-232 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple, selective and very sensitive assay is described for the quantification of physostigmine in blood, plasma and urine. The most appropriate solid phase column was selected after a systematic investigation of nine types of phase. The conditions for solid phase extraction were optimized using [3H]physostigmine so that the overall recoveries were 〉90%. Physostigmine was retained on alkaline treated cyanopropyl columns and eluted into the minimum volume of methanol, obviating the need for an evaporation step. Extracted samples were quantified by HPLC with a three electrode coulometric detection system. The limit of detection was 50 pg/mL for a 0.5 mL plasma sample. The precision (CV) for 0.5 mL plasma samples containing 50 pg was 8.1%. Application of the method to plasma, blood and urine samples is presented.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 251-254 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Meibomian secretions from the hamster were hydrolysed with base and examined as TMS, [2H9]TMS, methyl ester/TMS, picolinyl ester/TMS and nicotinate/TMS derivatives by capillary GC/MS. Over 90 compounds, representing over 89% of the hydrolysed fraction, were identified. Fatty acids with chain lengths from 10 to 32 carbon atoms were found, the most common of these were in the C15 to C18 and in the C25 to C30 regions. Chain types were predominantly iso or anteiso branched, mono-unsaturated (C16 and C18) and straight. Fatty alcohols were mainly from the iso or anteiso series and tended to have longer chain lengths; the major alcohols had anteiso-25 and 27 and iso-26-chains. In these respects the secretions were similar to those reported earlier from other species, although fewer mono-unsaturated compounds with longer chains (C20 to C30 region) were found than in the rat and human. The steroid fraction was characterized by a larger number of compounds than normally present in secretions of this type. The major compound was cholesterol, in common with that in all other examined species except the rabbit.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple and precise method was developed for the separation of nucleosides including modified nucleosides and oligonucleotides. Nineteen kinds of nucleosides were completely separated by HPLC using an ODS column (TSK-gel ODS 80TM) and aqueous mobile phases. The RNA molecule was digested by base restrictive RNase (RNase A, RNase T1) and the digests were separated chromatographically into each oligonucleotide. The nucleoside composition of an oligonucleotide was then determined by this analytical system. It is thus possible to fit the oligonucleotide in the original RNA molecule by using modified bases as markers. The reaction site of quinacrine mustard for tRNAPhe (from yeast) could be determined by this analytical system.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 262-265 
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A high performance liquid chromatographic method is described for the simultaneous determination of furosemide and bumetanide in horse plasma. The C8 (3 μm) reversed phase column (4.8 × 150 mm) provided clear separation of furosemide and bumetanide with other components present in the horse plasma. The detection limit for both the drugs was 10 ng/mL. Both drugs were stable in plasma (at natural or acidic pH) for up to 24 h. The method is sufficiently sensitive to detect furosemide levels in plasma obtained from horses receiving a therapeutic dose of furosemide.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 3 (1989), S. 601-608 
    ISSN: 0886-9383
    Keywords: Gas phase flow injection analysis ; Membrane-differentiated analysis ; Multicomponent determinations ; Successive linear regression ; Successive regression in fiduciary region ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A membrane-discriminated gas phase analyzer is proposed for multicomponent determinations. Nitrogen gas flows countercurrent through outer and inner channels in a tube-in-tube arrangement. The only communication between the two channels occurs through a 500 μm aperture covered by a porous PTFE membrane. A mixture of organic compounds (up to four components) is injected into the inner channel by a heated backflushed injector and the sample components diffusing into the outer channel are monitored by a flame ionization detector (FID). A calibration set, consisting of pure components, binary, ternary and quaternary mixtures (a total of 64 samples), provides the known data base: temporal profiles of the FID output as a function of sample composition. Although the overall response behavior is not a linearly additive function of individual analyte concentrations, the use of successive inverse multiple linear regression (while continually altering the choice of the calibration samples considered for the forward regression, on the basis of the most recent values of the predicted unknown sample composition) is shown to yield analytical results for unknown samples that are in good agreement with their true values.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 3 (1989), S. 609-609 
    ISSN: 0886-9383
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 174-176 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma levels and urinary excretion of mevalonate were reported to be correlated with cholesterol biosynthesis. Evaluation of mevalonate concentration in plasma and urine represents therefore a non-invasive method for studying the modifications of cholesterol synthesis. A method is described here by wich mevalonate in plasma and urine is determined by the selected ion monitoring technique after extraction as mevalonolactone and conversion into the trimethylsilyl ether. Linear responses were obtained in the evaluation of mevalonate added to plasma in the 10-100 ng/ml (r 〉 0.995) and to urine in the 50-1000 ng/ml concentration ranges, respectively. Identity of mevalonate in plasma and urine was confirmed by high-resolution mass spectrometry.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 86
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment (FAB) mass spectrometry was used to characterize the pyochelin complexes of iron and zinc. Ferripyochelin readily forms the [M + H]+ and [2M + H]+ ions in a glycerol matrix. The molecular ion was 2.5 fold more abundant when acetic acid was present. Iron was shown to be present in the iron-pyochelin complex as the ferric ion by wet chemical methods. Differentiation between ferric and ferrous ions by FAB was not successful owing to the FAB reducing environment. Ferric ions were reduced by FAB to ferrous ions in the following model salts - ferric chloride, ferric nitrate and ferric sulfate - when dissolved in either glycerol, thioglycerol or the magic bullet matrix. Ferric and ferrous chloride salts gave virtually identical spectra with a glycerol/acetic acid matrix. Zinc-pyochelin readily forms the [M + H]+ and [2M + H]+ ions, but only when acetic acid was present in the glycerol matrix. The FAB mass spectrum of zinc-pyochelin exhibited various fragmentations which can be used in structural analysis. Linked-scan at constant B/E and accurate mass data were used to characterize the fragmentations of the zinc-pyochelin complex. Metastable analysis allowed the fragmentation pathway of zinc-pyochelin to be determined.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 207-217 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electron impact (EI) mass spectra of 2,6-di-tert-butyl-4-methylphenol (BHT) and certain of its alteration products are described in detail. Accurate mass measurements confirm the elemental compositions of important fragment ions in the EI spectra. Collisionally activated mass spectra are also used to study fragmentation and suggest common ion structures. The reference spectra provide the basis for identifying various alteration products of BHT by capillary gas chromatography/mass spectrometry (GC/MS) without the necessity of isolating individual components. Application of GC/MS is made to three studies: (i) pyrolysis of hydroperoxy-BHT as a potential pathway to alteration products in food; (ii) GC/MS pyrolysis of hydroperoxy-BHT as a model study; and (iii) alteration of BHT in ethanol/water as a food-simulating solvent.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 363-372 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The MI and CA spectra of selected positive and negative ions generated by fast atom bombardment (FAB) of the stereoisomeric aldohexoses can be used to differentiate among these isomers, without prior derivatization or addition of other substances. The main fragmentation routes were traced and compared to those of some 2- and 6-deoxyaldohexoses, which appeared to be suitable model compounds. In both positive and negative ion FAB mass spectrometry, the OH group at the C-2 position plays an important role in the fragmentation reactions of the pseudomolecular [M + glycerol + H]+ and [M - H]- ions.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 387-393 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chicken intestinal calbindin-D28k is an intracellular protein which is believed to have a fundamental role in vitamin D-mediated transport of calcium. A mapping approach based on 252Cf plasma desorption mass spectrometry (PD mapping) was used to screen the DNA-deduced sequence of calbindin-D28k for sequence changes and posttranslational modifications. In the PD mapping experiment, purified calbindin-D28k was cleaved with cyanogen bromide and the resulting peptides were subjected to PD mass spectrometric analysis either as a mixture or as high-performance liquid chromatography isolated fractions. The DNA-derived primary structure of calbindin-D28k was confirmed by rapid PD mass spectral identification of the CNBr peptide fragments, and the nature of the N-terminal blocking group was readily determined to be an acetyl group. The relatively non-destructive nature of the PD mass spectrometric analysis allowed the mapping of the N-terminal peptide through an additional in situ V8 protease enzymatic reaction.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 90
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A current limitation in the use of fast atom bombardment (FAB) mass spectrometric mapping of peptide mixtures, derived from enzymic digestion of proteins, is that most of the hydrophilic peptides are not observed. However, it has been demonstrated from previous work that esterification of the peptide mixture results in the detection of almost all peptides in FAB mass spectrometry. This strategy of FAB mapping was applied to the protein actinidin, isolated from an Italian variety of Actinidia chinensis. Two of the 12 tryptic peptides in FAB mass spectrometry did not exhibit molecular ions predicted from the known sequence of actinidin isolated from the New Zealand variety of A. chinensis. The two peptides were isolated by high-performance liquid chromatography, subjected to Staphylococcus aureus V8 protease digestion and sequenced by gas-phase microsequencing. Nine changes in amino acid composition were detected using the rapid and powerful combination of FAB mass spectrometric mapping and gas-phase microsequencing.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 91
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The metabolism of 17α-methyl-17β-hydroxy-2-oxa-5α-androstan-3-one (oxandrolone) in man has been investigated by gas chromatography/mass spectrometry. After oral administration of a 10 mg dose to man, five metabolites were detected in the free fraction of the urinary samples. Oxandrolone, the major compound excreted in urine, was detected within 72 h after administration. During this period 35.8 and 8.4% of the administered dose was excreted as unchanged oxandrolone and 17-epioxandrolone, respectively. In addition, minute amounts of 16α- and 16β- hydroxyoxandrolone and a δ-hydroxy acid resulting from the hydrolysis of the lactone group of oxandrolone were detected in the urine samples 8-60 h after administration. Furthermore, the susceptibility of oxandrolone to hydrolysis was investigated under several pH conditions. Extraction and fractionation of steroidal metabolites was achieved by using C18 and silica Sep Pak™ chromatography. The mass spectra of the metabolites are presented and major fragmentation pathways discussed.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An increasing amount of evidence is accumulating to support the proposal that steroidogenesis can occur by a sesterterpene pathway as well as the cholesterol pathway. Key intermediates on the sesterterpene pathway are 23,24-dinor-5-cholen-3β-ol (guneribol) and some of its metabolites, e.g. 23,24-dinor-4-cholen-3-one (guneribone). It has been reported that these intermediates are biosynthesized and converted to steroid hormones by a range of endocrine tissues in vitro. Monitoring the pentafluorobenzyloxime derivatives by negative ion chemical ionization mass spectrometry in the electron capture mode provided evidence for the presence of guneribone in extracts of bovine testicular and human adrenal tumour tissue. Complementary evidence was obtained from gas chromatographic/tandem mass spectrometric data generated on a triple-quadrupole instrument by monitoring daughter ions (in the multiple ion detection, MID mode) of the molecular anion of derivatized guneribone in both standards and tissue extracts. The present findings that sesterterpene pathway intermediates are present as endogenous compounds in tissue extracts, together with the previously reported radiochemical data, give further support to the sesterterpene pathway hypothesis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A gas chromatographic/mass spectrometric analytical procedure is described to determine glycols in plasma as cyclic butyl boronate esters. The method, involving a pre-deproteinization step, required only 0.25 ml of plasma and a short time (20 min) to react with the derivatizing agent (butyl boronic acid). The gas chromatographic separation on a CP Sil 8 CB silica capillary column coupled to a mass detector assured a complete identification of the compounds. The analytical recoveries (〉95%) with low coefficient of variation (4-11%) assured the feasibility of the method over a concentration range from 5 to 1000 μg ml-1 for each glycol. The lower detection limits, namely 1-5 μg ml-1, confirmed the sensitivity of the method.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 603-612 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of tetradeuterated 10-methylundecanoic acid, dideuterated tetracos-2-enoic acid, (1-14C)pristanic acid and (1-14C)tetracos-2-enoic acid using the Favorsky rearrangement are described. They will be used for studies of long-chain fatty acid metabolism in patients. The positions of isotope labelling were determined by mass spectrometry.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 617-619 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Negative ion fast atom bombardment mass spectrometry is used to verify the sequence of oligodeoxyribonucleotides containing a single modified nucleotide. Both the position in the sequence and the molecular weight of the modified nucleotide can be determined from the 3′ and 5′-phosphate sequence ions which are prominent in the mass spectrum.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 620-623 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A number of sulphonyl hydrazones and derivatives have been synthesized and tested for biological activity as pesticides during the crop protection research programme at the Hatfield Polytechnic. A recent comparative ionization study of some of these compounds using electron impact (EI), fast atom bombardment (FAB) and various chemical ionization methods showed FAB mass spectrometry to be the optimum technique to use in terms of molecular weight information obtained. This study compares the FAB mass spectral data in positive and negative ion mode using an alternating positive and negative ion detection system.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 97
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermospray liquid chromatography/mass spectrometry (LC/MS) interface has had a major impact on the direct analysis of the metabolic fate of xenobiotics in complex biological media. This paper outlines the rapidity and power of the LC/MS approach, and shows how detailed structural information can be obtained without recourse to individual compound isolation. This provides a great saving in time and effort. The additional specificity of liquid chromatography/tandem mass spectrometry is highlighted in identifying the sites of metabolic transformation. The ability to handle biological samples with little or no clean-up using wide high-performance liquid chromatographic gradients is a key feature of the success of this methodology.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 629-636 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several populations of Achillea species were collected from Hungarian localities. The characteristic composition cf the essential oils of almost 220 populations were determined by gas chromatography/mass spectrometry. The main component of Achillea asplenifolia, A. setacea and A. collina oils is chamazulene, with a molecular mass of 184. The composition of some A. setacea is different: instead of chamazulene it contains a significant amount of farnesene. Oils of A. distans, A. crithmifolia, A. nobilis, A. pannonica and A. ochroleuca contain some different and specific compounds instead of chamazulene. During the analysis of many essential oils, we found some very interesting differences within species originating from another geographical area.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 99
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Deficiency of biotin at the tissue level can be assessed indirectly by measuring the urinary excretion of 3-hydroxyisovaleric acid. This paper describes the application of an improved method of quantifying urinary 3-hydroxyisovaleric acid using unlabeled and uniformly deuterated 3-hydroxyisovaleric acid. These compounds were synthesized by a modification of the lithioacetic acid method for generation of beta-hydroxy acids. Elemental analysis, nuclear magnetic resonance, gas chromatographic and gas chromatographic/mass spectrometric data demonstrated that the compounds are greater than 95% pure. Mass spectrometry confirmed the identity of the unlabeled compound, demonstrated that the deuterated compound is uniformly labeled, and offered insight into the pattern of mass fragmentation. The method for determination of the concentration of 3-hydroxyisovaleric acid in rat urine uses gas chromatographic/mass spectrometric quantification of the di-trimethylsilyl derivative with the deuterated compound as the internal standard. Results provide evidence that this method is more accurate than a previously published method that did not utilize the unlabeled and deuterated standards.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The metabolism of deutrated cortisol (9,12,12,-2H)cortisol, (2H3-F) was compared to that of radioactive cortisol (3H2-F) and natural cortisol, when these three compounds were administered simultaneously to an adrenalectomized piglet. The relative isotope dilution of tritium was determined from the specific activities of the main urinary neutral cortisol metabolites, tetrahydrocortisone (THE) and tetrahydrocortisol (THF), normalized to that of the cortisol mixture administered. To obtain a comparison of the isotope dilution of deuterium in the metabolites THE and THF to that in the cortisol mixture, the three steroids were converted to the common oxidation product 11-oxo-aetiocholanolone, and deivatized to the methoxime-tert-butyl-dimethylsilyl ether. The relative 2H-isotope dilution then was measured by gas chromatography/mass spectrometry. It was found that the specific activity of THE in the cumulative urine collections was similar to that of the cortisol mixture administered; the two-day value was, however, less. The specific activity of THF was slightly but significantly smaller than 1 (∼0.9) at all times. The relative 2H-isotope dilution in THE was slightly but significantly larger than one (∼1.1) at all times, whereas that in the THF was larger than 1.0 at 9 and 32 h or equal to 1.0 at 20 and 47 h of urine collection. When comparing the metabolism of the two tracer cortisol species the quotient of the 3H- and the 2H-isotope dilutions in THE and THF was smaller than 1.0. It can be concluded that (2H3)cortisol may be used for the determination of the cortisol production rate.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...