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  • Polymer and Materials Science  (112,478)
  • Inorganic Chemistry  (83,665)
  • Life and Medical Sciences  (48,545)
  • Analytical Chemistry and Spectroscopy  (25,705)
  • Engineering General  (9,884)
  • Agrobacterium
  • gene expression
  • somatic hybridization
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  • 1
    Electronic Resource
    Electronic Resource
    The interferon-α regulation of interferon regulatory factor 1 (IRF-1) and IRF-2 has therapeutic implications in carcinoid tumors (2000)
    Springer
    Annals of oncology 11 (2000), S. 707-714 
    Details
    ISSN: 1569-8041
    Keywords: gene expression ; IRF-1 and IRF-2 ; p68 ; PKR ; signal transduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background:Interferon regulatory factor 1 (IRF-1) has beendemonstrated to possess antiproliferative and tumor suppressor functions, onthe contrary, IRF-2 has been suggested to induce oncogenetic effect in somecell lines, but not evaluated in tumor patients. Patients and methods:In 35 carcinoid tumor patients, expressionsof IRF-1 and IRF-2 were investigated by immunohistochemistry and their valueswere analyzed with clinical treatment response. In carcinoid tumor cell line,Bon1, effects of IFN-α on the expression of both IRF-1 and IRF-2 mRNAs andproteins were determined by Northern blot, RNase protection assays and Westernblot analysis. Results:IFN-α up-regulated the expression of IRF-1 and IRF-2both in vivoand in vitro. In carcinoid tumors, IFN-αtreatment led to a significant increase in the expression of IRF-1 (P〈 0.001) and IRF-2 (P 〈 0.001). Moreover, the IRFs inductionwas correlated with the clinical response of IFN-α treatment, althoughtheir baseline values were not predictive. In addition, expressions of IRF-1and IRF-2 were significantly correlated with the p68kinaseexpression (P = 0.032 and P = 0.0176, respectively) and theexpression of IRF-1 protein was positively correlated with that of IRF-2(r = 0.671,P = 0.0001) tested in the same specimens. Conclusions:IRF-1 as well as IRF-2 have therapeutic implicationsin carcinoid tumors during treatment with interferon-α and IRFs inductionmight be used as indicators of response to treatment with interferon-α.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008314804492
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  • 2
    Electronic Resource
    Electronic Resource
    Agrobacterium mediated transformation of chickpea (Cicer arietinum L.) embryo axes (2000)
    Springer
    Plant cell reports 19 (2000), S. 235-240 
    Details
    ISSN: 1432-203X
    Keywords: Key words Chickpea ; Transformation ; Agrobacterium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Embryo axes of four accessions of chickpea (Cicer arietinum L.) were treated with Agrobacterium tumefaciens strains C58C1/GV2260 carrying the plasmid p35SGUSINT and EHA101 harbouring the plasmid pIBGUS. In both vectors the GUS gene is interrupted by an intron. After inoculation shoot formation was promoted on MS medium containing 0.5 mg/l BAP under a selection pressure of 100 mg/l kanamycin or 10 mg/l phosphinothricin, depending on the construct used for transformation. Expression of the chimeric GUS gene was confirmed by histochemical localization of GUS activity in regenerated shoots. Resistant shoots were grafted onto 5-day-old dark-grown seedlings, and mature plants could be recovered. T-DNA integration was confirmed by Southern analysis by random selection of putative transformants. The analysis of 4 plantlets of the T1 progeny revealed that none of them was GUS-positive, whereas the presence of the nptII gene could be detected by polymerase chain reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002990050005
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  • 3
    Electronic Resource
    Electronic Resource
    An Agrobacterium tumefaciens transformation protocol effective on a variety of cottonwood hybrids (genus Populus) (2000)
    Springer
    Plant cell reports 19 (2000), S. 315-320 
    Details
    ISSN: 1432-203X
    Keywords: Key words Poplar ; Populus ; Aspen ; Cottonwood ; Transformation ; Agrobacterium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We describe a protocol for Agrobacterium tumefaciens-mediated transformation of hybrid cottonwoods (Populus sections Tacamahaca Spach. and Aigeiros Duby). The protocol has allowed routine transformation of several economically important cottonwood hybrids (Populus trichocarpa Torr. & Gray×P. deltoides Bartr. ex. Marsh. and P. deltoides×P. nigra L.) that were previously difficult to transform. The procedure was applied to 11 different hybrid cottonwood genotypes and one P. deltoides genotype using kanamycin as the selection agent. Additional experiments showed a very strong interaction between auxin preculture and the effectiveness of various cytokinins for induction of shoot organogenesis. The data also demonstrated the superiority of Agrobacterium strain EHA105 over C58 and LBA4404 for T-DNA transfer based on transient assays with a reporter gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002990050019
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  • 4
    Electronic Resource
    Electronic Resource
    Agrobacterium tumefaciens-mediated transformation and transgenic-plant regeneration of onion (Allium cepa L.) (2000)
    Springer
    Plant cell reports 19 (2000), S. 376-381 
    Details
    ISSN: 1432-203X
    Keywords: Key words Allium cepa ; Transformation ; Regeneration ; gfp gene ; Agrobacterium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  An Agrobacterium tumefaciens-mediated transformation method has been developed for onions (Allium cepa L.) using immature embryos as the explant source. Transgenic plants were recovered from the open-pollinated onion cultivar Canterbury Longkeeper at a maximum transformation frequency from immature embryos of 2.7%. The method takes between 3–5 months from explant to primary regenerant entering the glasshouse. Multiple-shoot formation from primary transgenic material made possible the clonal multiplication of transformants. The binary vector used carried the nptII antibiotic resistance gene and the m-gfp5-ER reporter gene. Transgenic cultures were initially screened for their ability to fluoresce and to grow in the presence of geneticin (5–25 mg/l). The transgenic nature of individual plants was confirmed by Southern blot analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002990050743
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  • 5
    Electronic Resource
    Electronic Resource
    Preservation of Gene Expression Ratios Among Multiple Complex cDNAs After PCR Amplification: Application to Differential Gene Expression Studies (2000)
    Springer
    Journal of structural and functional genomics 1 (2000), S. 1-7 
    Details
    ISSN: 1570-0267
    Keywords: cDNA ; PCR cDNA ; TaqMan Analysis ; gene expression ; Pearson's correlation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Comparative gene expression studies are often limited by low availability of tissue and poor quality of extractable mRNA. Collective PCR amplification of minute quantities of mRNA has great potential for overcoming these limitations. However, there remains significant concern about the effects of amplification on the absolute and relative abundance of individual mRNAs that could complicate subsequent gene expression studies. To address this problem, we systematically compared the relative abundance of many specific mRNAs from complex cDNA preparations (from tissue and cultured cells) both before and after amplification by PCR. Our results demonstrated that, as expected, the absolute abundance of different mRNAs in a cDNA library is altered in an unpredictable manner by PCR amplification. However, we found that the concentration ratios of specific mRNAs among different cDNA preparations were routinely well conserved after PCR amplification. Thus, for the purpose of comparative expression studies for specific mRNAs in two (or more) complex cDNAs, PCR-amplified cDNA is equally useful as unamplified cDNA. These results provide a rigorous experimental validation and offer a theoretical treatment to support the utility of PCR amplified cDNA for differential gene expression studies. We conclude that the inherent difficulties in performing differential screening studies such as gene chip and array analyses on limited amounts of biological materials can be overcome by a PCR amplification step without compromising data quality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011337409258
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  • 6
    Electronic Resource
    Electronic Resource
    Dexamethasone induced cardiac hypertrophy in newborn rats is accompanied by changes in myosin heavy chain phenotype and gene transcription (2000)
    Springer
    Molecular and cellular biochemistry 209 (2000), S. 165-174 
    Details
    ISSN: 1573-4919
    Keywords: myosin heavy chain ; gene expression ; hypertrophy ; dexamethasone ; promoter function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Cardiac hypertrophy has been observed in newborn infants treated with dexamethasone (DEX). This study was undertaken to examine whether DEX-induced hypertrophy in newborn rats is associated with redistribution of cardiac myosin heavy chain (MHC) isoforms and if so, the effects involve transcriptional regulation. Newborn rats were injected with either DEX (1 mg/kg/day; s.c.) or equivalent volume normal saline for 1, 3, 5, 7 or 9 days. Hypertrophy was quantified by heart dry/wet wt ratios, heart/body wt ratios, and total protein content of the myocardium. Changes in the expression of cardiac MHC mRNA were characterized by northern blot and slot blot analyses, using isoform specific probes for a- and β-MHC genes. DEX effect on α-MHC gene transcription was analyzed by transiently transfecting various α-MHC promoter/CAT reporter constructs into primary cultures of cardiac myocytes derived from one day old rat pups. DEX administration into newborn rats produced significant cardiac hypertrophy ranging from 23% at day 1 to 59% at 9 days. The hypertrophy was accompanied by immediate increase (83%) in steady state level of the α-MHC mRNA within one day and a maximum increase (148%) at 7 days of treatment. The steady state level of β-MHC mRNA declined by 25% at day 1 and a maximum decrease of 54% at day 7 of DEX treatment. The changes in MHC mRNA were also reflected in their protein levels as determined by V1 and V3 isozyme analysis. DEX treatment of primary cultures of cardiomyocytes following transfection with a-MHC promoter/CAT reporter constructs resulted in increased CAT expression in a dose dependent manner. The minimum α-MHC gene sequences responding to DEX treatment were located between the -200 to -74-bp region of the gene, resulting in 2-fold and 6-fold activation of CAT reporter after 0.05 and 0.1 mM doses of DEX, respectively. Our data indicate that DEX induced cardiac hypertrophy in newborn rats is accompanied by increased expression of α-MHC and decreased expression of β-MHC. The α-MHC effects are mediated in part through transcriptional mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007128300430
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  • 7
    Electronic Resource
    Electronic Resource
    Mechanisms of transcriptional activation of cAMP-responsive element-binding protein CREB (2000)
    Springer
    Molecular and cellular biochemistry 212 (2000), S. 5-9 
    Details
    ISSN: 1573-4919
    Keywords: transcriptional regulation ; gene expression ; coactivator ; repressor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The CREB-CREM transcription factors are the main gene regulatory effectors of the cAMP signaling pathway. The investigations of this family of transcription factors had a profound impact on the understanding of signaling-induced gene transcription. Here we discuss some key aspects of the underlying biology, review transcriptional activation by CREB proteins through transcription cofactors and present novel insights into the context- and position-specific function of CREB on complex genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007111818628
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  • 8
    Electronic Resource
    Electronic Resource
    Upstream regulatory elements in chick heme oxygenase-1 promoter: A study in primary cultures of chick embryo liver cells (2000)
    Springer
    Molecular and cellular biochemistry 209 (2000), S. 17-27 
    Details
    ISSN: 1573-4919
    Keywords: AP-1 ; cobalt chloride ; gene expression ; heme oxygenase ; oxidative stress ; sodium arsenite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Previously, chick heme oxygenase-1 (cHO-1) gene was cloned by us and two regions important for induction by sodium arsenite were identified. These two regions were found to contain consensus sequences of an AP-1 (-1580 to -1573) and a MRE/cMyc complex (-52 to -41). In the current study, the roles of these two elements in mediating the sodium arsenite or cobalt chloride dependent induction of cHO-1 were investigated further. DNA binding studies and site-directed mutagenesis studies indicated that both the AP-1 and MRE/cMyc elements are important for the sodium arsenite induction, while cobalt chloride induction involves only the AP-1 element. Electrophoretic mobility shift assays showed that nuclear proteins binding to the AP-1 element was increased by both sodium arsenite or cobalt chloride treatment, whereas the binding of proteins to the MRE/cMyc element showed a high basal expression in untreated cells and the binding activity was only slightly increased by sodium arsenite treatment. Site-directed mutagenesis studies showed that, to completely abolish sodium arsenite induction, both the AP-1 and MRE/cMyc elements must be mutated; mutation of either element alone resulted in only a partial effect. In contrast, a single mutation at AP-1 element was sufficient to reduce the cobalt chloride induction almost completely. The MRE/cMyc complex plays a major role in the basal level expression, and shares some similarities to the upstream stimulatory factor element (USF) identified in the promoter regions of mammalian HO-1 genes and other stress regulated genes. Because sodium arsenite is known to cause oxidative stress and because activation of AP-1 proteins has been shown to be a key step in the oxidative stress response pathway, we also explored the possibility that the induction of the cHO-1 gene by sodium arsenite is mediated through oxidative stress pathway(s) by activation of AP-1 proteins. We found that pretreatment with antioxidants (N-acetyl cysteine or quercetin) reduced the induction of the endogenous cHO-1 message or cHO-1 reporter construct activities induced by sodium arsenite or cobalt chloride. These antioxidants also reduced the protein binding activities to the AP-1 element in the electrophoretic mobility shift assays. In summary, induction of the cHO-1 gene by sodium arsenite or cobalt chloride is mediated by activation of the AP-1 element located at -1,573 to -1,580 of the 5′ UTR.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007025505842
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  • 9
    Electronic Resource
    Electronic Resource
    Kidney ischemia-reperfusion: Modulation of antioxidant defenses (2000)
    Springer
    Molecular and cellular biochemistry 205 (2000), S. 1-11 
    Details
    ISSN: 1573-4919
    Keywords: kidney ; ischemia-reperfusion injury ; free radicals ; reactive oxygen species ; gene expression ; antioxidant enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Reactive oxygen species (ROS; O2-, H2O2, and OH·), normal by-products of cellular metabolic processes, are kept in control by antioxidant enzymes, such as catalase, glutathione peroxidase (GPX) and superoxide dismutases (SODs). To understand the role of antioxidant enzymatic defenses against ROS injury following ischemia-reperfusion, we examined the effect on kidney exposed to varying periods (30, 60 or 90 min) of ischemia followed by different periods of reperfusion. The enzymatic activities and protein levels of catalase, GPX, CuZnSOD and MnSOD were relatively unaffected at 30 min of ischemia followed by 0, 2 or 24 h reperfusion. However, 60 or 90 min of ischemia followed by 0, 2 or 24 h of reperfusion resulted in a decrease in activities and protein levels which paralleled the duration of ischemic injury. MnSOD activity tended to recover towards normal during reperfusion. Examination of the mRNA levels of these antioxidant enzymes demonstrated a severe decrease in mRNA levels of catalase and GPX at a time point of minimal ischemic injury (30 min of ischemia followed by reperfusion) suggesting that loss of mRNA of catalase and GPX may be the first markers of alterations in cellular redox in ischemia-reperfusion injury. Greater loss of mRNA for catalase, GPX and CuZnSOD were observed following longer periods (60 or 90 min) of ischemia. The mRNA for MnSOD was upregulated at all time points of ischemia-reperfusion injury. Actually, the greater decrease in mRNAs for catalase, GPX and CuZnSOD in the acute phase (within 24 h) subsequently showed a further decrease in these enzyme activities in the subacute phase (72 or 120 h after ischemia). These enzyme activities in the 30 min ischemia group, but not in the 90 min group, already showed tendencies for normalization at 120 h after ischemia. To understand the molecular basis of the loss of mRNA of these antioxidant enzymes during ischemia-reperfusion injury, we examined the rate of transcription by nuclear run-on assays. The similar rates of transcription in control and kidney exposed to ischemia-reperfusion indicates that the loss of mRNA for catalase, GPX and CuZnSOD are possibly due to the increased rate of turnover of their mRNAs. These studies suggest that expression of antioxidant genes during ischemia-reperfusion are not coordinately expressed and the differential loss of antioxidant enzymes may be the contributing factor(s) towards the heterogeneous renal tissue damage as a result of ischemia-reperfusion induced oxidative stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007047505107
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  • 10
    Electronic Resource
    Electronic Resource
    Transcriptional regulation of cyclooxygenase-2 in the Human Microvascular Endothelial Cell Line, HMEC-1: Control by the combinatorial actions of AP2, NF-IL-6 and CRE elements (2000)
    Springer
    Molecular and cellular biochemistry 203 (2000), S. 41-51 
    Details
    ISSN: 1573-4919
    Keywords: prostaglandin ; cyclooxygenase ; transcriptional regulation ; gene expression ; promotor activation ; transcription ; endothelial cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Interleukin-1β (IL-1) is a potent inducer of cyclooxygenase-2 (COX-2) and prostaglandin biosynthesis in many types of cells, yet little is known about the molecular mechanisms regulating IL-1 mediated prostanoid biosynthesis in the endothelium of the microvasculature. Therefore, we examined the cis- and trans-acting factors regulating IL-1-induced COX-2 expression in the human microvascular endothelial cell line, HMEC-1. IL-1 enhanced steady state levels of COX-2 protein and mRNA synthesis by ≈ 2-fold which preceded a 2-fold increase in PGFα biosynthesis. Expression of a series of COX-2 promoter-luciferase constructs in IL-1 treated HMEC-1 cells revealed that the 'full length' (-1432/+59 bp) promoter was 10 times more active than the SV-40 promoter/enhancer and that it could be further activated by IL-1. Surprisingly however, all except for the shortest COX-2 promoter construct retained the ability to respond to IL-1 and luciferase activity driven by -191/+59 bp COX-2 promoter was as responsive to IL-1 as the full-length promoter. Moreover, site-directed promoter mutagenesis and electophoretic mobility shift assays (EMSA) indicate that the combinatorial actions of AP2, NF-IL6, and CRE elements are critical for both constitutive and IL-1-inducible COX-2 promoter activity. Understanding the mechanism(s) regulating COX-2 gene expression and prostaglandin biosynthesis in the microvasculature has important implications with regard to inflammation and angiogenesis in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007045600664
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  • 11
    Electronic Resource
    Electronic Resource
    Characterization of a 5′-flanking region supporting the transcription of mouse thymosin β-4 in mouse NIH3T3 cells (2000)
    Springer
    Molecular and cellular biochemistry 203 (2000), S. 163-167 
    Details
    ISSN: 1573-4919
    Keywords: thymosin β-4 ; gene expression ; chloramphenicol acetyltransferase ; NIH3T3 cells ; interferon response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Expression of the gene coding for thymosin β-4 (Tβ-4), the major G-actin sequestering peptide in the cell, is regulated mainly at the level of transcription. In this study, we examined the nucleotide sequence of the 5′-flanking region (from - 2202 to - 881) of the mouse Tβ-4 gene, and demonstrated that the DNA fragment from -278 to +410 of this gene was capable of directing the expression of a chloramphenicol acetyltransferase reporter gene in NIH3T3 cells. However, expression of the reporter gene in cells cannot be induced by interferon-a treatment even though a rapid activation of endogenous Tβ-4 gene by this cytokine was observed. These results suggest that the projected interferon-stimulated response element (ISRE) might reside in other parts of the mouse Tβ-4 gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007020619788
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  • 12
    Electronic Resource
    Electronic Resource
    The effect of thioacetamide on the activity and expression of cytosolic rat liver glutathione-S-transferase (2000)
    Springer
    Molecular and cellular biochemistry 211 (2000), S. 103-110 
    Details
    ISSN: 1573-4919
    Keywords: thioacetamide ; glutathione-S-transferase ; rat liver ; transcription ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of thioacetamide (TA), an hepatotoxic and hepatocarcinogenic compound, on the expression and activity of the cytosolic enzyme glutathione-S-transferase (GST) was studied in rat liver. Four h following the administration of 14C-labeled thioacetamide (10 mg/Kg), several subunits of GST were found to be radioactively labeled. A single sublethal dose of TA (250 mg/Kg) decreased by three-fold the expression of classα GST at 24-48 h of treatment, but did not significantly affect the transcription of class μ GST. The activity of the enzyme toward 1-chloro-2,4-dinitrobenzene was mildly inhibited (66% of the control) by a 24 h TA treatment and gradually increased thereafter. It is proposed that the covalent binding of TA or its derivative to the GST subunits does not affect the activity of the enzyme. Nevertheless, GST activity inhibition is due to the deleterious effect of TA on GST transcription.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007114801362
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  • 13
    Electronic Resource
    Electronic Resource
    Apolipoprotein E gene expression is reduced in apolipoprotein A-I transgenic mice (2000)
    Springer
    Molecular and cellular biochemistry 209 (2000), S. 125-129 
    Details
    ISSN: 1573-4919
    Keywords: apolipoprotein E ; apolipoprotein A-I ; gene expression ; transgenic mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The levels of plasma apolipoprotein (apo) E, an anti-atherogenic protein involved in mammalian cholesterol transport, were found to be 2-3 fold lower in mice over-expressing human apoA-I gene. ApoE is mainly associated with VLDL and HDL-size particles, but in mice the majority of the apoE is associated with the HDL particles. Over-expression of the human apoA-I in mice increases the levels of human apoA-I-rich HDL particles by displacing mouse apoA-I from HDL. This results in lowering of plasma levels of mouse apoA-I. Since plasma levels of apoE also decreased in the apoA-I transgenic mice, the mechanism of apoE lowering was investigated. Although plasma levels of apoE decreased by 2-3 fold, apoB levels remained unchanged. As expected, the plasma levels of human apoA-I were almost 5-fold higher in the apoAI-Tg mice compared to mouse apoA-I in WT mice. If the over-expression of human apoA-I caused displacement of apoE from the HDL, the levels of hepatic apoE mRNA should remain the same in WT and the apoAI-Tg mice. However, the measurements of apoE mRNA in the liver showed 3-fold decreases of apoE mRNA in apoAI-Tg mice as compared to WT mice, suggesting that the decreased apoE mRNA expression, but not the displacement of the apoE from HDL, resulted in the lowering of plasma apoE in apoAI-Tg mice. As expected, the levels of hepatic apoA-I mRNA (transgene) were 5-fold higher in the apoAI-Tg mice. ApoE synthesis measured in hepatocytes also showed lower synthesis of apoE in the apoAI-Tg mice. These studies suggest that the integration of human apoA-I transgene in mouse genome occurred at a site that affected apoE gene expression. Identification of this locus may provide further understanding of the apoE gene expression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007107712725
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  • 14
    Electronic Resource
    Electronic Resource
    CRE-decoy oligonucleotide-inhibition of gene expression and tumor growth (2000)
    Springer
    Molecular and cellular biochemistry 212 (2000), S. 29-34 
    Details
    ISSN: 1573-4919
    Keywords: cAMP ; transcription factor-decoy oligonucleotides ; CRE ; Ap-1 ; p53 ; tumor growth ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Nucleic acid molecules with high affinities for a target transcription factor can be introduced into cells as decoy cis-elements to bind these factors and alter gene expression. This review discusses a synthetic single-stranded palindromic oligonucleotide, which self-hybridizes to form a duplex/hairpin and competes with cAMP response element (CRE) enhancers for binding transcription factors. This oligonucleotide inhibits CRE- and Ap-1-directed gene transcription and promotes growth inhibition in vitro and in vivo in a broad spectrum of cancer cells, without adversely affecting normal cell growth. Evidence presented here suggests that the CRE-decoy oligonucleotide can provide a powerful new means of combating cancers, viral diseases, and other pathological conditions by regulating the expression of cAMP-responsive genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007144618589
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  • 15
    Electronic Resource
    Electronic Resource
    Catecholamines and angiotensinogen gene expression in kidney proximal tubular cells (2000)
    Springer
    Molecular and cellular biochemistry 212 (2000), S. 73-79 
    Details
    ISSN: 1573-4919
    Keywords: adrenergic receptors ; renin-angiotensin system (RAS) ; gene expression ; kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract To investigate the molecular mechanism(s) of action of catecholamines on the expression of the angiotensinogen (ANG) gene in kidney proximal tubular cells, we used opossum kidney (OK) cells with a fusion gene containing the 5′-flanking regulatory sequence of the rat ANG gene fused with a human growth hormone (hGH) gene as a reporter, pOGH (rANG N-1498/+18), permanently integrated into their genomes. The level of expression of the ANG-GH fusion gene was quantified by the amount of immunoreactive-hGH (IR-hGH) secreted into the medium. The addition of norepinephrine (NE), isoproterenol (a β1/β2-adrenergic receptor (AR) agonist) and iodoclonidine (an α2-AR agonist) stimulated the expression of the ANG-GH fusion gene in a dose-dependent manner, whereas the addition of epinephrine and phenylephrine (α1-AR agonist) had no effect. The stimulatory effect of NE was blocked by the presence of propranolol (β-AR blocker), atenolol (β1-AR blocker), yohimbine (α2-AR blocker), Rp-cAMP (an inhibitor of cAMP-dependent protein kinase AI & AII) and staurosporine (an inhibitor of protein kinase C), but was not blocked by ICI 118, 551 (β2-AR blocker) and prazosin (α1-AR blocker). The addition of a combination of isoproterenol and iodoclonidine or a combination of 8-Bromo-cAMP (8-Br-cAMP) and phorbol 12-myristate (PMA) synergistically stimulated the expression of the ANG-GH fusion gene as compared to the addition of isoproterenol, iodoclonidine, 8-Br-cAMP or PMA alone. Furthermore, the addition of NE, 8-Br-cAMP or PMA stimulated the expression of pOGH (rANG N-806/-779/-53/+18), a fusion gene containing the putative cAMP responsive element (CRE, ANG N-806/-779) upstream of the ANG promoter (ANG N-53/+18) in OK cells, but had no effect on the expression of fusion genes containing the mutant of the CRE. Gel mobility shift assays revealed that the ANG-CRE binds with the DNA-binding domain (bZIP 254-327) of the cAMP-responsive binding protein (CREB). The binding of the labeled ANG-CRE to CREB (bZIP254-327) was displaced by unlabeled ANG-CRE and the CRE of the somatostatin gene but not by the mutants of the ANG-CRE. Finally, NE stimulated the phosphorylation of CREB in OK cells. These studies demonstrate that the molecular mechanism(s) of NE action on the expression of the ANG gene in OK cells may be mediated via both the PKA and PKC signalling pathways and via the phosphorylation of CREB. The phosphorylated CREB then interacts with the CRE in the 5′-flanking region of the ANG gene and subsequently stimulates the gene expression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007152821315
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  • 16
    Electronic Resource
    Electronic Resource
    Control of cardiomyocyte gene expression as drug target (2000)
    Springer
    Molecular and cellular biochemistry 212 (2000), S. 135-142 
    Details
    ISSN: 1573-4919
    Keywords: gene expression ; catecholamines ; angiotensin II ; heart failure ; myosin ; hypertension ; eprosartan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Pressure overload of the heart is associated with a perturbed gene expression of the cardiomyocyte leading to an impaired pump function. The ensuing neuro-endocrine activation results in disordered influences of angiotensin II and catecholamines on gene expression. To assess whether angiotensin II type 1 receptor inhibition can also counteract a raised sympathetic nervous system activity, spontaneously hypertensive rats fed a hypercaloric diet were treated with eprosartan (daily 90 mg/kg body wt) and cardiovascular parameters were monitored with implanted radiotelemetry pressure transducers. Both, blood pressure and heart rate were increased (p 〈 0.05) by the hypercaloric diet. Although eprosartan reduced (p 〈 0.05) the raised systolic and diastolic blood pressure, the diet-induced rise in heart rate was blunted only partially. In addition to drugs interfering with the enhanced catecholamine influence, compounds should be considered that selectively affect cardiomyocyte gene expression via 'metabolic' signals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007181626766
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  • 17
    Electronic Resource
    Electronic Resource
    Expression of renin-angiotensin system and extracellular matrix genes in cardiovascular cells and its regulation through AT1 receptor (2000)
    Springer
    Molecular and cellular biochemistry 212 (2000), S. 203-209 
    Details
    ISSN: 1573-4919
    Keywords: angiotensinogen ; fibronectin ; gene expression ; transcriptional regulation ; cardiomyocytes ; vascular smooth muscle cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Angiotensinogen (AGT) is a unique substrate of the renin-angiotensin system and fibronectin (FN) is an important component of the extracellular matrix. These play critical roles in the pathophysiological changes including cardiovascular remodeling and hypertrophy in response to hypertension. This study was performed to examine the regulation of AGT and FN gene in cardiac myocytes (CMs) and vascular smooth muscle cells (VSMCs) in response to mechanical stretch. Mechanical stretch significantly increased the AGT mRNA expression in CMs, while these stimuli did not affect FN mRNA levels. On the other hand, Mechanical stretch upregulated FN mRNA levels in VSMCs, whereas no increase in AGT mRNA levels was observed in response to stretch stimuli. An angiotensin II type 1 (AT1) receptor antagonist (CV11974) significantly decreased these stretch-mediated increases in mRNA level and promoter activity of the AGT and FN gene, whereas angiotensin II type 2 (AT2) receptor antagonist (PD123319) did not affect the induction. These results indicate that mechanical stretch activates transcription of the AGT and FN gene mainly via AT1 receptor-pathway in CMs and VSMCs. Furthermore, mechanisms regulating AGT and FN gene seem to be different between CMs and VSMCs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007141912654
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  • 18
    Electronic Resource
    Electronic Resource
    Regulation of angiotensin II receptors in the medullary thick ascending limb (2000)
    Springer
    Molecular and cellular biochemistry 212 (2000), S. 211-217 
    Details
    ISSN: 1573-4919
    Keywords: angiotensin receptor ; medullary thick ascending limb ; sodium intake ; primary cell culture ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Angiotensin II (Ang II) is an important regulator of the function of medullary thick ascending limb of loop of Henle (MTAL). Recent studies showed that changes in Ang II receptor expression occur and underlie changes in the function of proximal tubules during altered sodium intake. The present experiment was designed to determine (1) whether expression of the type 1 Ang II (AT1) receptor in the MTAL is regulated by altered sodium intake, and (2) the specific pathway(s) mediating sodium-induced AT1 expression in the MTAL. Wistar rats were fed a normal sodium (0.5%, NS), low sodium (0.07%, LS), or high sodium (4%, HS) diet for 2 weeks. Northern blot analysis and radioligand binding showed that in rats fed a normal sodium diet the rank of order for both AT1 mRNA expression and receptor density was outer medulla 〉 cortex 〉 inner medulla. Sodium restriction significantly increased both AT1 mRNA expression and receptor density in the outer medulla. In contrast, neither AT1 mRNA expression nor receptor density in the outer medulla was altered by sodium loading. Losartan treatment (3 mg/kg/per day by oral gavage for 2 weeks) prevented low sodium-induced upregulation of the AT1 receptor in the outer medulla, but it had no effect on AT1 expression in the outer medulla of rats fed a normal sodium diet. Highly purified suspensions of MTAL were isolated from rats fed a normal or low sodium diet. Low sodium intake significantly increased AT1 mRNA level by 184% and AT1 receptor density by 58% in MTALs. Primary cultures of MTAL cells were treated with PBS, Ang II (10-8 M), and Ang II + 17 octadecynoic (17 ODYA, 10 μM). Ang II caused about 2-fold increase in AT1 mRNA levels, and this increase was diminished by about 30% by the addition of 17 ODYA. We conclude that (1) sodium restriction but not sodium loading increases AT1 receptor expression in the MTAL, (2) low sodium-induced upregulation of the AT1 receptor in the MTAL is Ang II-dependent, and (3) Ang II-induced upregulation of the AT1 receptor in the MTAL is mediated, at least in part, by cytochrome P450 pathways.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007193931309
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  • 19
    Electronic Resource
    Electronic Resource
    Role of cardiac renin-angiotensin system in sarcoplasmic reticulum function and gene expression in the ischemic-reperfused heart (2000)
    Springer
    Molecular and cellular biochemistry 212 (2000), S. 227-235 
    Details
    ISSN: 1573-4919
    Keywords: renin angiotensin system ; sarcoplasmic reticulum ; Ca2+-handling ; gene expression ; ischemia-reperfusion ; cardioprotection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The aim of this study was to explore the possible participation of cardiac renin-angiotensin system (RAS) in the ischemia-reperfusion induced changes in heart function as well as Ca2+-handling activities and gene expression of cardiac sarcoplasmic reticulum (SR) proteins. The isolated rat hearts, treated for 10 min without and with 30 μM captopril or 100 μM losartan, were subjected to 30 min ischemia followed by reperfusion for 60 min and processed for the measurement of SR function and gene expression. Attenuated recovery of the left ventricular developed pressure (LVDP) upon reperfusion of the ischemic heart was accompanied by a marked reduction in SR Ca2+-pump ATPase, Ca2+-uptake and Ca2+-release activities. Northern blot analysis revealed that mRNA levels for SR Ca2+-handling proteins such as Ca2+-pump ATPase (SERCA2a), ryanodine receptor, calsequestrin and phospholamban were decreased in the ischemia-reperfused heart as compared with the non-ischemic control. Treatment with captopril improved the recovery of LVDP as well as SR Ca2+-pump ATPase and Ca2+-uptake activities in the postischemic hearts but had no effect on changes in Ca2+-release activity due to ischemic-reperfusion. Losartan neither affected the changes in contractile function nor modified alterations in SR Ca2+-handling activities. The ischemia-reperfusion induced decrease in mRNA levels for SR Ca2+-handling proteins were not affected by treatment with captopril or losartan. The results suggest that the improvement of cardiac function in the ischemic-reperfused heart by captopril is associated with the preservation of SR Ca2+-pump activities; however, it is unlikely that this action of captopril is mediated through the modification of cardiac RAS. Furthermore, cardiac RAS does not appear to contribute towards the ischemia-reperfusion induced changes in gene expression for SR Ca2+-handling proteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007174803993
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  • 20
    Electronic Resource
    Electronic Resource
    Attenuation of changes in sarcoplasmic reticular gene expression in cardiac hypertrophy by propranolol and verapamil (2000)
    Springer
    Molecular and cellular biochemistry 213 (2000), S. 111-118 
    Details
    ISSN: 1573-4919
    Keywords: pressure overload ; gene expression ; subcellular remodeling ; sarcoplasmic reticulum Ca2+-handling ; anti-hypertensive therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effects of propranolol and verapamil on contractile dysfunction, subcellular remodeling and changes in gene expression in cardiac hypertrophy due to pressure overload were examined. Rats were subjected to banding of the abdominal aorta and then treated with either propranolol (10 mg/kg daily), verapamil (5 mg/kg daily) or vehicle for 8 weeks after the surgery. Depression of the left ventricular function in the hypertrophied heart was associated with decreases in myofibrillar and myosin CA2+ ATPase activities as well as Ca2+-pump and Ca2+-release activities of the sarcoplasmic reticulum (SR). The level of a-myosin heavy chain (α-MHC) mRNA was decreased while that of β-MHC mRNA was increased in the pressure-overloaded heart. The level of SR Ca2+-pump ATPase (SERCA2) mRNA and protein content for SERCA2 were decreased in the pressure overloaded heart. Treatment of the hypertrophied animals with propranolol or verapamil resulted in preservation of the left ventricular function and prevention of the subcellular alterations. Shift in the α- and β-MHC mRNA levels and changes in the expression in SERCA2 mRNA level and protein content were also attenuated by these treatments. The results suggest that blockade of β-adrenoceptors or voltage-dependent calcium channels normalizes the cardiac gene expression, prevents subcellular remodeling and thus attenuates heart dysfunction in rats with cardiac hypertrophy. Furthermore, both cardiac β-adrenoceptors and L-type Ca2+-channels may be involved in the genesis of cardiac hypertrophy due to pressure overload.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007120332587
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  • 21
    Electronic Resource
    Electronic Resource
    Cloning and characterization of the rat TIS11 gene (2000)
    Springer
    Molecular and cellular biochemistry 213 (2000), S. 119-126 
    Details
    ISSN: 1573-4919
    Keywords: TIS11 ; an immediate early gene ; gene cloning ; gene expression ; gene organization ; promoter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The TIS11 gene is an immediate early gene that is induced rapidly and transiently by phorbol 12-myristate 13-acetate and various growth factors. To study transcriptional regulation of the gene, a genomic clone of rat TIS11 was isolated, and the organization of exon-intron structure and transcriptional initiation site were determined. The rat TIS11 gene consisted of 2 exons spanning approximately 2.5 kb. Several canonical sequences for binding of transcriptional factors were found in the 5′-flanking region. The 5.3 kb of the 5′-flanking region fused to a luciferase reporter gene showed promoter activity when introduced into rat pheochromocytoma PC12 cells. Analyses with serial 5′-deletion mutants suggested that the major positive regulatory region is located at the region of -241 to -76, and that the minimum promoter region is within the 76-bp upstream of the transcriptional initiation site. Gel mobility shift assays revealed that PC12 cell nuclear proteins specifically bind to the major positive regulatory region of the TIS11 gene. The identified nuclear protein components may act as the positive trans-acting factors in the basal expression of the TIS11 gene in PC12 cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007172316657
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  • 22
    Electronic Resource
    Electronic Resource
    Expression and activity of antioxidant enzymes during potato tuber dormancy (2000)
    Springer
    Potato research 43 (2000), S. 383-393 
    Details
    ISSN: 1871-4528
    Keywords: Solanum tuberosum L. ; plant development ; antioxidant genes ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The expression of antioxidant genes has been analyzed in a potato plant and during tuber dormancy. Manganese superoxide dismutase (MnSOD), cytosolic copper and zinc superoide dismutase (Cu/ZnSOD), catalase class II, cytosolic ascorbate peroxidase (APX) and glutathione peroxidase (GPX) are expressed at the RNA level in all the contexts analyzed. By contrast, the expression of the iron superoxide dismutase (FeSOD) and plastidic Cu/ZnSOD seems to be limited to green tissues, as shown by northern blots and native gels. A complex DAB-peroxidase isozyme pattern (using diaminobenzidine as substrate) has been observed in different developmental contexts analyzed, but hardly observed in tubers. During tuber dormancy, MnSOD and cytosolic Cu/ZnSOD activity was relatively constant in both Désirée and Bintje varieties while catalase activity decreases. Moreover, tuber dormancy breakage did not involve significant changes in the activity of these enzymes. On the basis of these results, the possible link between active oxygen species (AOS) metabolism and dormancy is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02360542
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  • 23
    Electronic Resource
    Electronic Resource
    Erwinia resistance in backcross progenies ofSolanum tuberosum x S. tarijense andS. tuberosum (+) S. commersonii hybrids (2000)
    Springer
    Potato research 43 (2000), S. 135-142 
    Details
    ISSN: 1871-4528
    Keywords: tuber soft rot ; 2n gametes ; sexual hybridization ; somatic hybridization ; germplasm exploitation ; potato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The resistance to tuber soft rot caused byErwinia carotovora ofSolanum tuberosum x S. tarijense andS. tuberosum (+) S. commersonii hybrids and their backcrosses is reported. A number of resistant diploid sexual hybrids and tetraploid/hexaploid somatic hybrids were selected. Backcross progenies were obtained through 2x×4x crosses involving a resistant diploid hybrid and tetraploidS. tuberosum, and through 4x×4x crosses between a resistant somatic hybrid andS. tuberosum. The hybrids showed high variability interms of resistance to tuber soft rot. The resistance of progeny from 2x×4x backcrosses was similar to that of the parental sexual hybrid. By contrast, the resistance of genotypes deriving from 4x×4x backcrosses was reduced compared with the resistant somatic hybrid. In general, tuber characteristics of the backcross hybrids improved considerably as compared with their parents, and tuber yield per plant was good.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02357954
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  • 24
    Electronic Resource
    Electronic Resource
    Functional genomic analysis of potato tuber life-cycle (2000)
    Springer
    Potato research 43 (2000), S. 297-312 
    Details
    ISSN: 1871-4528
    Keywords: gene expression ; cDNA-AFLP ; RNA-fingerprinting ; organogenesis ; tuberisation ; dormancy ; sprouting ; cluster analysis ; metabolic pathways
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Potato tuber life-cycle is composed of many individual developmental stages including tuber formation, tuber development, dormancy and sprouting. We have used cDNA-AFLP fingerprinting to analyse gene expression in 24 individual stages of development, over the period from stolon formation through sprouting. In addition to these developmental stages, different tissues were analysed to assess tissue specificity and various controls were incorporated to determine process specificity. In total around 18000 transcript derived cDNA fragments (TDFs) were visualised from which circa 2600 were included in a statistical analysis allowing general conclusions about gene expression during development. More than 200 process specific TDFs were isolated and sequenced throughout the potato tuber life-cycle. The sequence similarities of these TDFs to known genes give an insight into the kinds of processes occurring during tuberisation, dormancy and sprouting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02360536
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  • 25
    Electronic Resource
    Electronic Resource
    Agrobacterium tumefaciens-mediated transformation of the aromatic shrub Lavandula latifolia (2000)
    Springer
    Molecular breeding 6 (2000), S. 539-552 
    Details
    ISSN: 1572-9788
    Keywords: Agrobacterium ; inheritance analysis ; Lavandula latifolia ; lavender ; organogenesis ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Transgenic plants of the aromatic shrub Lavandula latifolia (Lamiaceae) were produced using Agrobacterium tumefaciens-mediated gene transfer. Leaf and hypocotyl explants from 35–40-day old lavender seedlings were inoculated with the EHA105 strain carrying the nptII gene, as selectable marker, and the reporter gusA gene with an intron. Some of the factors influencing T-DNA transfer to L. latifolia explants were assessed. Optimal transformation rates (6.0 ± 1.6% in three different experiments) were obtained when leaf explants precultured for 1 day on regeneration medium were subcultured on selection medium after a 24 h co-cultivation with Agrobacterium. Evidence for stable integration was obtained by GUS assay, PCR and Southern hybridisation. More than 250 transgenic plants were obtained from 37 independent transformation events. Twenty-four transgenic plants from 7 of those events were successfully established in soil. β-glucuronidase activity and kanamycin resistance assays in greenhouse-grown plants from two independent transgenic lines confirmed the stable expression of both gusA and nptII genes two years after the initial transformation. Evidence from PCR data, GUS assays and regeneration in the presence of kanamycin demonstrated a 1:15 Mendelian segregation of both transgenes among seedlings of the T1 progeny of two plants from one transgenic L. latifolia line.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011332904024
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  • 26
    Electronic Resource
    Electronic Resource
    Study of the factors influencing Agrobacterium-mediated transformation of pea (Pisum sativum L.) (2000)
    Springer
    Molecular breeding 6 (2000), S. 185-194 
    Details
    ISSN: 1572-9788
    Keywords: Agrobacterium ; transformation ; pea ; Pisum sativum L. ; PCR analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Factors influencing the efficiency of Agrobacterium-mediated transformation of pea were tested using highly efficient, direct regeneration system. The virulence of three Agrobacterium strains (octopine LBA 4404, nopaline C58C1 and succinamopine, hypervirulent EHA 105) clearly varied giving 1 transgenic plant per 100 explants for LBA 4404, 2.2 for C58C1 and 8.2 for EHA 105. To test the efficacy of selection agents we used the hypervirulent EHA 105 strain carrying pGPTV binary vector with one of four different selection genes: nptII, hpt, dhfr or bar. The mean number of transgenic, kanamycin-resistant plants for two cultivars tested was 4.2 per 100 explants and was slightly higher than the number of phosphinothricin-resistant plants (3.6 plants per 100 explants). The proportion of transgenics among kanamycin-selected plants was also higher than among phosphinothricin-resistant plants (35% and 28% respectively). There was no regeneration on hygromycin or methotrexate media (transformation with hpt and dhfr genes). Acetosyringone had no apparent influence on efficiency of transformation with hypervirulent EHA 105 strain, however it did affect the rate of transformation when moderately virulent C58C1 was used. Recovery of transgenic plants was enhanced after application of 5-azacytidine. The presence of integrated T-DNA was checked by PCR and confirmed by Southern hybridization. T-DNA was stably transmitted to the next generation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009679908948
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  • 27
    Electronic Resource
    Electronic Resource
    Cu, Zn superoxide dismutase deficiencyaccelerates the time course of an age-related markerin Drosophila melanogaster (2000)
    Springer
    Biogerontology 1 (2000), S. 163-169 
    Details
    ISSN: 1573-6768
    Keywords: aging ; Cu, Zn superoxide dismutase ; Drosophila melanogaster ; gene expression ; wingless
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the oxidative stress hypothesis of aging therandom accumulation of oxidative damage over time ispostulated to cause aging. The pace at whichoxidative damage accrues determines the rate of aging,but it is less clear how the accumulation of randomdamage could cause the stereotypic pattern of aging. It has been proposed that oxidative damage induceschanges in gene expression, translating a random inputof damage into a patterned output. In support of thiswe show that in adult Drosophila melanogaster,with a deficiency in the anti-oxidant enzyme Cu, Znsuperoxide dismutase (Sod), an increase in oxidativestress, and a shortened life span, there isacceleration in the normal age-related temporalpattern of wingless gene expression. Theacceleration in the temporal pattern of winglessgene expression is proportional to the shortened lifespan suggesting that the shortened life span of Soddeficient animals is due, not to an abnormalpathological process, but to an increase in the rateof aging.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010039813107
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  • 28
    Electronic Resource
    Electronic Resource
    Regulation of NADPH-cytochrome P450 reductase expressed during Douglas-fir germination and seedling development (2000)
    Springer
    Plant molecular biology 44 (2000), S. 141-153 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; germination ; NADPH-cytochrome P450 reductase ; Pseudotsuga menziesii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract NADH-cytochrome P450 is a key enzyme that transfers electrons from NADPH to the cytochrome P450 family of enzymes. To begin to determine the regulation of CPR gene expression and enzyme activity in Douglas-fir a full-length cDNA was isolated from a seedling λZAP cDNA library and the ORF was used to develop a synthetic CPR-peptide-based antiserum. Northern blot analysis indicated CPR expression was regulated both developmentally prior to seed maturation and during germination, and differentially in the cotyledons, radicle and megagametophyte of seed and seedling tissues. The CPR-peptide antiserum detected a single CPR in seed and seedling microsomes analyzed by western blot of two-dimensional SDS-polyacrylamide gels. In microsomal extracts from whole seeds and seedlings, the amount of CPR protein remained constant while NADPH:cytochrome c reductase activity increased during stratification, germination and early seedling development. In contrast to cotyledons and megagametophyte, the level of CPR protein detected in radicles was higher than expected when compared to the amount of CPR transcript.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006425025702
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  • 29
    Electronic Resource
    Electronic Resource
    The nitrate reductase promoter of birch directs differential reporter gene expression in tissues of transgenic tobacco (2000)
    Springer
    Plant and soil 221 (2000), S. 33-38 
    Details
    ISSN: 1573-5036
    Keywords: ammonium ; birch ; gene expression ; nia promoter ; nitrate ; nitrate reductase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A 1535 bp promoter of the nitrate reductase gene (nia) from birch (Betula pendula) and a series of 5′ deletions were fused to the β-glucuronidase (GUS) gene and introduced into Nicotiana plumbaginifolia. In transgenic plants the NR promoter sequences directed strong GUS expression in the root epidermal hair cells, and in phloem cells of leaf and stem vascular tissue. The NR promoter confers also a significant stimulation of the GUS gene expression by nitrate. These findings might indicate that nitrate flow is one of the signals involved into tissue and cell specific expression of the NR promoter GUS fusions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004739621352
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  • 30
    Electronic Resource
    Electronic Resource
    Molecular approaches to study plasma membrane H+-ATPases in arbuscular mycorrhizas (2000)
    Springer
    Plant and soil 226 (2000), S. 219-225 
    Details
    ISSN: 1573-5036
    Keywords: arbuscular mycorrhizas ; gene expression ; Glomus mosseae ; nutrient transport processes ; plasma membrane H+-ATPases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The activity of H+-ATPases of plant and fungi generates an electrochemical gradient of H+ across the cell plasma membrane that drives a number of secondary transport systems, including those responsible for the translocation of cations, anions, amino acids and sugars. During the last years, several studies have been aimed at elucidating the role of plasma membrane H+-ATPases in the nutrient exchange processes taking place between the plant and the fungus in arbuscular mycorrhizal (AM) symbiosis. This paper reviews present knowledge about plasma membrane H+-ATPases and experimental evidence supporting the involvement of H+-ATPases of both organisms in the bidirectional transport of nutrients between partners. Molecular strategies that will provide further information on the function and regulation of plasma membrane H+-ATPases in AM symbiosis are presented and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026469109773
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  • 31
    Electronic Resource
    Electronic Resource
    Plant responses to ultraviolet-B (UV-B: 280–320 nm) stress: What are the key regulators? (2000)
    Springer
    Plant growth regulation 32 (2000), S. 27-39 
    Details
    ISSN: 1573-5087
    Keywords: ethylene ; gene expression ; jasmonic acid ; reactive oxygen species ; salicylic acid ; ultraviolet-B radiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Depletion of the stratospheric ozone layer is leadingto an increase in ultraviolet-B (UV-B: 280–320 nm)radiation reaching the earth's surface. This hasraised interest in the possible consequence ofincreased UV-B levels on plant growth and developmentand the mechanisms underlying these responses. Although the effects of UV-B are now wellcharacterised at the physiological level, little isknown about the cellular and molecular mechanismsinvolved. Recent studies have shown that UV-B affectsa number of important physiological processes, such asphotosynthesis, through effects on gene expression. In addition, induction of a number of defensemechanisms, such as production of UV-B screeningpigments, increase in antioxidant enzymes andinduction of pathogenesis-related proteins, are alsomediated at the level of gene expression. The signaltransduction pathways by which UV-B regulates geneexpression are at present poorly understood. Thestudies carried out to date have, however, indicateda pivotal role for reactive oxygen species as keysecond messengers acting up-stream of a number ofpathways involving the plant hormones salicylic acid,jasmonic acid and ethylene. The transduction pathwaysidentified to date and the role of intermediates inregulating tolerance to UV-B damage are discussed inthis review.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006314001430
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  • 32
    Electronic Resource
    Electronic Resource
    Biochemical and molecular aspects of fruitlet abscission (2000)
    Springer
    Plant growth regulation 31 (2000), S. 35-42 
    Details
    ISSN: 1573-5087
    Keywords: β-1,4-endoglucanase ; ethylene ; fruit ; gene expression ; polygalacturonase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Fruitlet abscission during fruit development is due to the activation ofpre-differentiated abscission zones (AZs) located between twig andpedicel, and/or pedicel and pericarp. Major advances on biochemicaland molecular aspects are related to β-1,4-endoglucanase (EG) andpolygalacturonase (PG), two cell hydrolases involved in the cell walldisassemblement responsible for fruit shedding. AZ activation isaccompanied by an increase in activity and transcript accumulation ofone or both enzymes. Expression of PG genes specifically related toabscission has been found in tomato flower AZ. In peach, an EG genehighly expressed in leaf and fruitlet AZs has been isolated. AZactivation is preceded by an induction of ethylene biosynthesis,paralleled by a stimulation of ACO activity and transcript accumulation.Ethylene, besides a dramatic stimulation of PG and EG, up or downregulates several other abscission related genes. The specificexpression of genes encoding for ethylene receptors in the AZ wouldsupport the hypothesis that fruitlet AZ specificity may depend on theability of this region to sense ethylene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006338210977
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  • 33
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    Electronic Resource
    Molecular cloning and expression analysis of the mevalonate kinase gene from Arabidopsis thaliana (2000)
    Springer
    Plant molecular biology 42 (2000), S. 365-376 
    Details
    ISSN: 1573-5028
    Keywords: Arabidopsis thaliana ; β-glucuronidase (GUS) reporter gene ; gene expression ; isoprenoids ; mevalonate kinase ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mevalonate kinase (MVK), the enzyme that catalyzes the phosphorylation of mevalonate to produce mevalonate 5-phosphate, is considered as a potential regulatory enzyme of the isoprenoid biosynthetic pathway. The Arabidopsis thaliana MVK gene corresponding to the MVK cDNA previously isolated has been cloned and characterized. RNAse protection analysis indicated that the expression of the MVK gene generates three mRNA populations with 5′ ends mapping 203, 254 and 355 nt upstream of the MVK ATG start codon. Northern blot analysis showed that the MVK mRNA accumulates preferentially in roots and inflorescences. Histochemical analysis, with transgenic A. thaliana plants containing a translational fusion of a 1.8 kb fragment of the 5′ region of the MVK gene to the β-glucuronidase (GUS) reporter gene, indicated that the MVK 5′-flanking region directs widespread expression of the GUS gene throughout development, although the highest levels of GUS activity are detected in roots (meristematic region) and flowers (sepals, petals, anthers, style and stigmatic papillae). The expression pattern of the MVK gene suggests that the role of the encoded MVK is the production of a general pool of mevalonate-5-phosphate for the synthesis of different classes of isoprenoids involved in both basic and specialized plant cell functions. Functional promoter deletion analysis in transfected A. thaliana protoplasts indicated that regulatory elements between positions −295 and −194 of the MVK 5′-flanking region are crucial for high-level MVK gene expression.
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    URL: http://dx.doi.org/10.1023/A:1006325630792
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  • 34
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    Isolation and characterization of two pathogen- and salicylic acid-induced genes encoding WRKY DNA-binding proteins from tobacco (2000)
    Springer
    Plant molecular biology 42 (2000), S. 387-396 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; hypersensitive responses ; plant defense responses ; salicylic acid ; tobacco mosaic virus ; WRKY DNA-binding proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A pathogen- and salicylic acid (SA)-induced DNA-binding activity has been recently identified in tobacco that is related to a previously identified class of WRKY DNA-binding proteins. To identify members of the WRKY gene family associated with this DNA-binding activity, we have attempted to isolate those WRKY genes that are induced by pathogen infection. Using a domain-specific differential display procedure, we have isolated two tobacco WRKY genes, tWRKY3 and tWRKY4, that are rapidly induced in resistant tobacco plants after infection by tobacco mosaic virus (TMV). Both tWRK3 and tWRKY4 encode proteins with a single WRKY domain that contain the conserved WRKYGQK sequence. Unlike other isolated WRKY proteins that contain the Cys2His2 zinc motif, tWRKY3 and tWRKY4 appear to contain the Cys2HisCys zinc motif. Nonetheless, both tWRKY3 and tWRKY4 are capable of binding DNA molecules with the W-box (TTGAC) element recognized by other WRKY proteins. Expression of the tWRKY3 and tWRKY4 genes could be rapidly induced not only by TMV infection but also by SA or its biologically active analogues that are capable of inducing pathogenesis-related genes and enhanced resistance. Interestingly, induction of both genes by TMV infection was still observed in resistant tobacco plants expressing the bacterial salicylate hydroxylase gene (nahG), although the levels of induction appeared to be reduced. Identification of pathogen- and SA-induced genes encoding WRKY DNA-binding proteins should facilitate future studies on the regulation and functions of this novel group of DNA-binding proteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006399311615
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  • 35
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    Cellular expression and regulation of the Medicago truncatula cytosolic glutamine synthetase genes in root nodules (2000)
    Springer
    Plant molecular biology 42 (2000), S. 741-756 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; glutamine synthetase ; legume-Rhizobium symbiosis ; nitrogen assimilation ; root nodules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this paper we have studied the localisation of expression of the two functional cytosolic glutamine synthetase (GS) genes, MtGSa and MtGSb, in root nodules of the model legume Medicago truncatula. We have used a combination of different techniques, including immunocytochemistry, in situ hybridisation and promoter β-glucuronidase (GUS) fusions in transgenic plants, to provide the means of correlating gene expression with protein localisation. These studies revealed that transcriptional regulation (mRNA synthesis) plays an important part in controlling GS protein levels in nodules of M. truncatula. The major locations of cytosolic GS mRNA and protein are the central tissue, the parenchyma and the pericycle of the vascular bundles. These findings indicate that in nodules, GS might be involved in other physiological processes in addition to the primary assimilation of ammonia released by the bacterial nitrogenase. The two genes show different but overlapping patterns of expression with MtGSa being the major gene expressed in the infected cells of the nodule. Promoter fragments of 2.6 kb and 3.1 kb of MtGSa and MtGSb, respectively, have been sequenced and primer extension revealed that the MtGSb promoter is expressed in nodules from an additional start site that is not used in roots. Generally these fragments in the homologous transgenic system were sufficient to drive GUS expression in almost all the tissues and cell types where GS proteins and transcripts are located except that the MtGSa promoter fragment did not express GUS highly in the nodule infected cells. These results indicate that the cis-acting regulatory elements responsible for infected-cell expression are missing from the MtGSa promoter fragment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006304003770
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  • 36
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    Electronic Resource
    pGreen: a versatile and flexible binary Ti vector for Agrobacterium-mediated plant transformation (2000)
    Springer
    Plant molecular biology 42 (2000), S. 819-832 
    Details
    ISSN: 1573-5028
    Keywords: Agrobacterium ; binary vectors ; plant transformation ; reporter genes ; selectable marker genes ; Ti vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Binary Ti vectors are the plasmid vectors of choice in Agrobacterium-mediated plant transformation protocols. The pGreen series of binary Ti vectors are configured for ease-of-use and to meet the demands of a wide range of transformation procedures for many plant species. This plasmid system allows any arrangement of selectable marker and reporter gene at the right and left T-DNA borders without compromising the choice of restriction sites for cloning, since the pGreen cloning sites are based on the well-known pBluescript general vector plasmids. Its size and copy number in Escherichia coli offers increased efficiencies in routine in vitro recombination procedures. pGreen can replicate in Agrobacterium only if another plasmid, pSoup, is co-resident in the same strain. pSoup provides replication functions in trans for pGreen. The removal of RepA and Mob functions has enabled the size of pGreen to be kept to a minimum. Versions of pGreen have been used to transform several plant species with the same efficiencies as other binary Ti vectors. Information on the pGreen plasmid system is supplemented by an Internet site (http://www.pgreen.ac.uk) through which comprehensive information, protocols, order forms and lists of different pGreen marker gene permutations can be found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006496308160
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  • 37
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    Electronic Resource
    Isolation of genes predominantly expressed in guard cells and epidermal cells of Nicotiana glauca (2000)
    Springer
    Plant molecular biology 42 (2000), S. 857-869 
    Details
    ISSN: 1573-5028
    Keywords: epidermis ; gene expression ; glycine-rich protein ; lipid transfer protein ; proline-rich protein ; stomata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Guard cells are specialized and metabolically active cells which arise during the differentiation of the epidermis. Using Nicotiana glauca epidermal peels as a source of purified guard cells, we have constructed a cDNA library from guard cell RNA. In order to isolate genes that are predominantly expressed in guard cells, we performed a differential screen of this library, comparing the hybridization of a radiolabeled cDNA probe synthesized from guard cell RNA to that from a mesophyll cell cDNA probe. Sixteen clones were isolated based on their greater level of hybridization with the guard cell probe. Of these, eight had high homology to lipid transfer protein (LTP), two were similar to glycine-rich protein (GRP), and one displayed high homology to proline-rich proteins from Arabidopsis thaliana (AtPRP2, AtPRP4) and from potato guard cells (GPP). Northern analysis confirmed that one or more NgLTP genes, NgGRP1, and NgGPP1 are all differentially expressed, with highest levels in guard cells, and low or undetectable levels in mesophyll cells and in roots. In addition, all are induced to some degree in drought-stressed guard cells. NgLTP and NgGRP1 expression was localized by in situ hybridization to the guard cells and pavement cells in the epidermis. NgGRP1 expression was also detected in cells of the vasculature. Genomic Southern analysis indicated that LTP is encoded by a family of highly similar genes in N. glauca. This work has identified members of a subset of epidermis- and guard cell-predominant genes, whose protein products are likely to contribute to the unique properties acquired by guard cells and pavement cells during differentiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006480107407
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  • 38
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    Electronic Resource
    Flower-predominant expression of a gene encoding a novel class I chitinase in rice (Oryza sativa L.) (2000)
    Springer
    Plant molecular biology 42 (2000), S. 883-897 
    Details
    ISSN: 1573-5028
    Keywords: chitinase function ; flower-predominant ; gene expression ; molecular cloning ; monocotyledon ; promoter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A flower-predominant cDNA for a gene, termed OsChia1;175, was isolated from a cDNA library of rice pistils. Northern blot and RT-PCR analyses revealed that the OsChia1;175 gene is highly expressed in floral organs (pistils, stamens and lodicules at the heading stage) but not or at an extremely low level in vegetative organs. OsChia1;175 encodes a protein that consists of 340 amino acid residues, and the putative mature protein shows 52% to 63% amino acid identity to class I chitinases of rice or other plants. The phylogenetic tree shows that the OsChia1;175 protein is a new type of plant class I chitinase in rice. The expression of OsChia1;175 in vegetative organs is not induced by several chemicals, UV, and wounding. The soluble putative mature OsChia1;175 protein expressed in Escherichia coli exhibited chitinase activity in the assay with colloidal chitin as a substrate. Genomic Southern analysis revealed that the OsChia1;175 gene was organized as a low-copy gene family. The rice genomic library was screened and a genome clone corresponding to OsChia1;175 was isolated. The transcription start sites of the OsChia1;175 gene were mapped by primer extension analysis. The 1.2 kb putative promoter region of the OsChia1;175 gene was fused to the GUS (β-glucuronidase) gene, and this chimeric gene was introduced to rice by Agrobacterium-mediated transformation. The flower-predominant gene expression was identified also in the transgenic rice plants. The high promoter activity was detected in the stigmas, styles, stamens and lodicules in transgenic plants. The possible functions of OsChia1;175 are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006401816145
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  • 39
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    Electronic Resource
    Anaerobiosis-specific interaction of tobacco nuclear factors with cis-regulatory sequences in the maize GapC4 promoter (2000)
    Springer
    Plant molecular biology 43 (2000), S. 11-21 
    Details
    ISSN: 1573-5028
    Keywords: anaerobiosis ; electrophoretic mobility shift assays ; gene expression ; glyceraldehyde-3-phosphate dehydrogenase ; Nicotiana tabacum ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The promoter of the maize glyceraldehyde-3-phosphate dehydrogenase 4 gene (GapC4) confers strong, specific and ubiquitous anaerobic reporter gene expression in tobacco. To identify factors required for heterologous anaerobic gene expression, 19 progressive 5′ and 3′ promoter deletions were linked to a chimeric GapC4 TATA box-β-glucuronidase (GUS) reporter gene construct and transformed into tobacco. In all transgenic lines aerobic expression values were in the range obtained for negative controls while histochemical GUS assays reveal some weak expression in roots only. Anaerobic induction of about 100-fold to more than 1000-fold above unspecific background is mediated by a region of about 190 bp of the GapC4 promoter. Anaerobic reporter gene induction strongly decreases upon deletion of a 20 bp fragment from −286 to −266 relative to the transcription start point. This fragment harbours putative cis-acting sequences. Electrophoretic mobility shift assays with a 50 bp fragment harbouring these cis sequences reveal a high-mobility complex that is formed with nuclear extracts from aerobic and anaerobic leaf tissue while an additional low-mobility complex is anaerobiosis-specific. The formation of the high-mobility complex requires the sequence GTGGGCCCG. The 50 bp fragment alone confers weak and orientation-dependent anaerobic induction to a GapC4 TATA box-β-glucuronidase (GUS) reporter gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006419232075
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  • 40
    Electronic Resource
    Electronic Resource
    Plant A-type cyclins† (2000)
    Springer
    Plant molecular biology 43 (2000), S. 659-675 
    Details
    ISSN: 1573-5028
    Keywords: A-type cyclins ; cell cycle ; gene expression ; regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Although the basic mechanisms which control the progression through the cell cycle appear to be conserved in all higher eukaryotes, the unique features of the plant developmental programme must be somehow reflected in a plant-specific regulation of the factors which control cell division. In the past few years, considerable progress has been achieved in identifying the major components of the cell cycle machinery in plants, especially the cyclin-dependent kinases (CDKs) and their regulatory subunits, the cyclins. The question of how these components direct expression of specific genes at specific stages of the cell cycle, and how they are themselves regulated, constitutes a challenge for the present and for the years to come. This review summarizes our current knowledge of a particular class of plant cyclins, the A-type cyclins, which can be further subdivided into three structural groups. The putative functions of these A-type cyclins are discussed in relation to the presence of remarkable motifs in their amino acid sequences, and to their specific transcriptional regulation, protein amount and subcellular localization.
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    URL: http://dx.doi.org/10.1023/A:1006303100592
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  • 41
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    The diageotropica mutation alters auxin induction of a subset of the Aux/IAA gene family in tomato (2000)
    Springer
    Plant molecular biology 44 (2000), S. 73-84 
    Details
    ISSN: 1573-5028
    Keywords: auxin ; Aux/IAA ; dgt ; gene expression ; Lycopersicon esculentum ; signal transduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The diageotropica (dgt) mutation has been proposed to affect either auxin perception or responsiveness in tomato plants. It has previously been demonstrated that the expression of one member of the Aux/IAA family of auxin-regulated genes is reduced in dgt plants. Here, we report the cloning of ten new members of the tomato Aux/IAA family by PCR amplification based on conserved protein domains. All of the gene family members except one (LeIAA7) are expressed in etiolated tomato seedlings, although they demonstrate tissue specificity (e.g. increased expression in hypocotyls vs. roots) within the seedling. The wild-type auxin-response characteristics of the expression of these tomato LeIAA genes are similar to those previously described for Aux/IAA family members in Arabidopsis. In dgt seedlings, auxin stimulation of gene expression was reduced in only a subset of LeIAA genes (LeIAA5, 8, 10, and 11), with the greatest reduction associated with those genes with the strongest wild-type response to auxin. The remaining LeIAA genes tested exhibited essentially the same induction levels in response to the hormone in both dgt and wild-type hypocotyls. These results confirm that dgt plants can perceive auxin and suggest that a specific step in early auxin signal transduction is disrupted by the dgt mutation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006437205596
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  • 42
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    Caleosins: Ca2+-binding proteins associated with lipid bodies (2000)
    Springer
    Plant molecular biology 44 (2000), S. 463-476 
    Details
    ISSN: 1573-5028
    Keywords: Arabidopsis thaliana ; calcium-binding protein ; caleosin ; EF-hand ; gene expression ; lipid bodies ; vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have previously identified a rice gene encoding a 27 kDa protein with a single Ca2+-binding EF-hand and a putative membrane anchor. We report here similar genes termed caleosins, CLO, in other plants and fungi; they comprise a multigene family of at least five members in Arabidopsis (AtClo1–5). Northern hybridization demonstrated that AtClo2–4 mRNAs levels were low in various tissues, while AtClo1 mRNA levels were high in developing embryos and mature seeds. Analysis of transgenic Arabidopsis plants expressing the GUS reporter under control of the AtClo1 promoter showed strong levels of expression in developing embryos and also in root tip cells. Antibodies raised against AtCLO1 were used to detect caleosin in cellular fractions of Arabidopsis and rapeseed. This indicated that caleosins are a novel class of lipid body proteins, which may also be associated with an ER subdomain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026564411918
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  • 43
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    Electronic Resource
    Proliferation of Mitochondria in Chronically Stimulated Rabbit Skeletal Muscle—Transcription of Mitochondrial Genes and Copy Number of Mitochondrial DNA (2000)
    Springer
    Journal of bioenergetics and biomembranes 32 (2000), S. 627-634 
    Details
    ISSN: 1573-6881
    Keywords: Mitochondrial biogenesis ; copy number ; gene expression ; mitochondrial transcription factor ; nuclear—mitochondrial communication ; stimulation ; endurance training
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Mitochondrial proliferation was studied in chronically stimulated rabbit skeletal muscle over a period of 50 days. After this time, subunits of COX had increased about fourfold. Corresponding mRNAs, encoded on mitochondrial DNA as well as on nuclear genes, were unchanged when related to total tissue RNA, however, they were elevated two- to fivefold when the massive increase of ribosomes per unit mass of muscle was taken into account. The same was true for the mRNA encoding mitochondrial transcription factor A. Surprisingly, tissue levels of mtTFA protein were reduced about twofold, together with mitochondrial DNA. In conclusion, mito chondria are able to maintain high rates of mitochondrial transcription even in the presence of reduced mtTFA protein and mtDNA levels. Therefore, stimulated mtTFA gene expression accompanies stimulated mitochondrial transcription, as in other models, but it is not sufficient for an increase of mtDNA copy number and other, yet unknown, factors have to be postulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005630813227
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  • 44
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    Electronic Resource
    Expression of the antibacterial peptide, cecropin, in cultured mammalian cells (2000)
    Springer
    Biotechnology letters 22 (2000), S. 151-155 
    Details
    ISSN: 1573-6776
    Keywords: antibacterial peptide ; cecropin ; gene expression ; mammalian cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract We have stably transfected a Chinese hamster lung cell line V79 with a recombinant gene construct where the Drosophila cecropin A2 cDNA is under the control of Rous sarcoma virus, long terminal repeat (RSV LTR). We have not only been able to demonstrate expression at the RNA level by Northern analysis but also have detected an unprocessed peptide using an antiserum raised against Hyalophora cecropin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005609728707
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  • 45
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    Electronic Resource
    Cyclic Core Dendrimer as a New Kind of Vector for Gene Transfer into Mammalian Cells (2000)
    Springer
    Genetica 108 (2000), S. 53-56 
    Details
    ISSN: 1573-6857
    Keywords: dendritic polymer ; reporter gene ; gene expression ; transfection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyclic core dendritic polymer is a new type of synthetic polymers. The ability of generation 4 of the dendrimer with a core of 1,4,7,10-tetraazacyclododecane to function as an effective gene delivery vector was investigated. Results from fluorescence in situhybridization (FISH) show that the pCH 110 plasmid DNA was transferred into human small intestine cancer metastatic ascites (HICMA) cells induced by this kind of dendrimer as a vector. The transferred LacZ, GFP and luciferase genes were highly expressed in the transfected HICMA, COS-7 and 293 cells. These studies demonstrate that the dendrimer can transfect mammalian cells in vitrowhich offers an alternatively efficient method for mammalian gene transfer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004047902652
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  • 46
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    Electronic Resource
    Regulation of Keratinocyte Growth Factor (KGF) and KGF Receptor mRNAs by Nutrient Intake and KGF Administration in Rat Intestine (2000)
    Springer
    Digestive diseases and sciences 45 (2000), S. 736-743 
    Details
    ISSN: 1573-2568
    Keywords: keratinocyte growth factor ; KGF receptor ; gene expression ; intestine ; nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to investigate the regulation of keratinocyte growth factor (KGF) and KGF receptor mRNAs by diet and KGF treatment in rat intestine. Fasting for three days up-regulated KGF and KGF receptor mRNA levels in ileum and increased KGF receptor mRNA expression in colon. KGF and KGF receptor mRNA levels returned toward control values with ad libitum refeeding but remained elevated when refeeding was limited to 25% of ad libitum intake. KGF treatment during nutrient repletion did not alter intestinal KGF mRNA levels but increased KGF receptor mRNA abundance in ileum and colon. We conclude that the increase in KGF and KGF receptor mRNAs induced by malnutrition may be an adaptive response to attenuate gut mucosal atrophy in this setting. The gut-trophic effects of KGF treatment may be mediated, in part, by up-regulation of the KGF receptor mRNA in small bowel and colon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005447827579
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  • 47
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    Electronic Resource
    Effects of increased and deregulated expression of cell division genes on the morphology and on antibiotic production of streptomycetes (2000)
    Springer
    Antonie van Leeuwenhoek 78 (2000), S. 269-276 
    Details
    ISSN: 1572-9699
    Keywords: differentiation ; FtsZ ; gene expression ; septum ; SsgA ; transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper describes the effects of increased expression of the cell division genes ftsZ, ftsQ, and ssgA on the development of both solid- and liquid-grown mycelium of Streptomyces coelicolor and Streptomyces lividans. Over-expression of ftsZ in S. coelicolor M145 inhibited aerial mycelium formation and blocked sporulation. Such deficient sporulation was also observed for the ftsZ mutant. Over-expression of ftsZ also inhibited morphological differentiation in S. lividans 1326, although aerial mycelium formation was less reduced. Furthermore, antibiotic production was increased in both strains, and in particular the otherwise dormant actinorhodin biosynthesis cluster of S. lividans was activated in liquid- and solid-grown cultures. No significant alterations were observed when the gene dosage of ftsQ was increased. Analysis by transmission electron microscopy of an S. coelicolor strain over-expressing ssgA showed that septum formation had strongly increased in comparison to wild-type S. coelicolor, showing that SsgA clearly influences Streptomyces cell division. The morphology of the hyphae was affected such that irregular septa were produced with a significantly wider diameter, thereby forming spore-like compartments. This suggests that ssgA can induce a process similar to submerged sporulation in Streptomyces strains that otherwise fail to do so. A working model is proposed for the regulation of septum formation and of submerged sporulation.
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    URL: http://dx.doi.org/10.1023/A:1010267708249
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  • 48
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    Expression of Four Genes of Bacteriophage MB78 from Contiguous Open Reading Frames: The Genomic Organization as Deduced by Sequence Analysis (2000)
    Springer
    Virus genes 20 (2000), S. 87-97 
    Details
    ISSN: 1572-994X
    Keywords: bacteriophage MB78 ; contiguous ORF ; unusual start codons ; genome analysis ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Four proteins of bacteriophage MB78 having apparent molecular weights as 35, 14, 21 and 16 kDa are expressed from 3.9 kb SalI-HindIII fragment located almost in the middle of the phage genome. Analysis of the sequence supported by some experimental evidences suggest that these four proteins are expressed from polycistronic message without any intercistronic gap. Stop and start codons of consecutive ORFs overlap and rare initiation codons are used. Computer analysis of the sequence suggests the presence of two more open reading frames within the ORFs of 35 and 16 kDa proteins but in the opposite orientation, i.e. in the complementary strand.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008168425571
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  • 49
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    Electronic Resource
    Ethylene regulation of fruit ripening: Molecular aspects (2000)
    Springer
    Plant growth regulation 30 (2000), S. 193-200 
    Details
    ISSN: 1573-5087
    Keywords: ACC synthase ; ACC oxidase ; ethylene ; fruit ; gene expression ; regulation ; ripening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Progress in ethylene regulating fruit ripening concerning itsperception and signal transduction and expression of ACC synthaseand ACC oxidase genes is reviewed. ACC synthase and ACC oxidasehave been characterized and their genes cloned from various fruittissues. Both ACC synthase and ACC oxidase are encoded bymultigene families, and their activities are associated withfruit ripening. In climacteric fruit, the transition toautocatalytic ethylene production appears to be due to a seriesof events in which ACC sythase and ACC oxidase genes have beenexpressed developmentally. Differential expression of ACCsynthase and ACC oxidase gene family members is probably involvedin such a transition that ultimately controls the onset of fruitripening.In comparison to ACC synthase and ACC oxidase, less is knownabout ethylene perception and signal transduction because of thedifficulties in isolating and purifying ethylene receptors orethylene-binding proteins using biochemical methods. However, theidentification of the Nr tomato ripening mutant as anethylene receptor, the applications of new potent anti-ethylenecompounds and the generation of transgenic fruits with reducedethylene production have provided evidence that ethylenereceptors regulate a defined set of genes which are expressedduring fruit ripening. The properties and functions of ethylenereceptors, such as ETR1, are being elucidated.Application of molecular genetics, in combination withbiochemical approaches, will enable us to better understand theindividual steps leading from ethylene perception and signaltransduction and expression of ACC synthase and ACC oxidase genefamily member to the physiological responses.
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    URL: http://dx.doi.org/10.1023/A:1006348627110
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  • 50
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    Electronic Resource
    Resistance to wheat leaf rust in Aegilops tauschii Coss. and inheritance of resistance in hexaploid wheat (2000)
    Springer
    Genetic resources and crop evolution 47 (2000), S. 135-140 
    Details
    ISSN: 1573-5109
    Keywords: Aegilops tauschii ; gene expression ; genetic inheritance ; Puccinia recondita f. sp. tritici ; rust resistance ; synthetic hexaploid wheats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A collection of 164 Aegilops tauschii accessions, obtained from Gatersleben, Germany, was screened for reaction to leaf rust under controlled greenhouse conditions. We have also evaluated a selection of synthetic hexaploid wheats, produced by hybridizing Ae. tauschii with tetraploid durum wheats, as well as the first and second generation of hybrids between some of these resistant synthetic hexaploid wheats and susceptible Triticum aestivum cultivars. Eighteen (11%) accessions of Ae. tauschii were resistant to leaf rust among which 1 was immune, 13 were highly resistant and 4 were moderately resistant. Six of the synthetic hexaploid wheats expressed a high level of leaf rust resistance while four exhibited either a reduced or complete susceptibility compared to their corresponding diploid parent. This suppression of resistance at the hexaploid level suggests the presence of suppressor genes in the A and/or B genomes of the T. turgidum parent. Inheritance of leaf rust resistance from the intercrosses with susceptible bread wheats revealed that resistance was dominant over susceptibility. Leaf rust resistance from the three synthetics (syn 101, syn 701 and syn 901) was effectively transmitted as a single dominant gene and one synthetic (syn 301) possessed two different dominant genes for resistance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008770226330
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  • 51
    Electronic Resource
    Electronic Resource
    Mechanisms regulating differential freezing tolerance of suspension cell cultures derived from contrasting alfalfa genotypes (2000)
    Springer
    Plant cell, tissue and organ culture 61 (2000), S. 143-151 
    Details
    ISSN: 1573-5044
    Keywords: fall dormancy ; gene expression ; Medicago sativa L. ; protein ; starch ; sugar ; winter hardiness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A major factor limiting persistence of alfalfa (Medicago sativa L.) in the northern US is poor winter hardiness. Our hypothesis is that suspension cell cultures derived from dormant, winter-hardy alfalfa cultivars would cold acclimate and survive sub-zero temperatures better than cell cultures derived from non-dormant, non-hardy cultivars. Our objectives were (1) to determine if genetic differences in winter hardiness between dormant and non-dormant alfalfa were retained by suspension cells derived from these contrasting cultivars; and (2) to determine the physiological and biochemical bases for differences in freezing tolerance of suspension cells. Cell suspensions derived from `5262' (fall dormant) and `5929' (fall non-dormant) were cold hardened at 2 °C for 14 days. Cells were frozen in a cooling bath and cell survival determined by measuring 2, 3, 5-triphenyltetrazolium chloride (TTC) reduction. Cold acclimation improved cell survival of both cultivars to −5 °C when compared to unacclimated cells. Only acclimated cells of 5262 survived temperatures of −10 °C to −25 °C. The freezing tolerance of cold-acclimated 5262 cells was associated with high sugar and starch concentrations, lower α-amylase activities and slightly lower cell protein levels when compared to 5929. No differences in polypeptide composition were evident when comparing acclimated and unacclimated cells of 5929, but polypeptide composition did change with acclimation of 5262 cells. As expected, expression of RootCAR1 in 5262 cells increased with cold acclimation, but high levels of RootCAR1 transcript were unexpectantly found in both cold acclimated and unacclimated 5929 cells. With the exception of the RootCAR1 expression, many of the physiological responses of these alfalfa cell lines to cold acclimation were similar to those that have been reported for field-grown plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006408829105
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  • 52
    Electronic Resource
    Electronic Resource
    Expression of maize γ-zein and β-zein genes in transgenic Nicotiana tabacum and Lotus corniculatus (2000)
    Springer
    Plant cell, tissue and organ culture 62 (2000), S. 141-151 
    Details
    ISSN: 1573-5044
    Keywords: Agrobacterium ; forage quality ; KDEL ; recombinant proteins ; sulphur-rich amino acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Accumulation of zeins, the endosperm storage proteins of maize, in a heterologous plant expression system was attempted. Plants of Nicotiana tabacum and Lotus corniculatus were transformed by Agrobacterium with binary vectors harbouring genes that code for γ-zein and β-zein, two zeins rich in sulphur amino acids. Adding the ER retention signal KDEL to the C-terminal domain modified the zein polypeptides. Significant levels of γ-zein:KDEL and β-zein:KDEL were detected in primary transformants of tobacco. Moreover, the two zeins colocalized in leaf protein bodies of γ-/β-zein:KDEL plants derived from a cross between two primary transformants. Coexpression of γ-zein:KDEL and β-zein:KDEL could be a useful strategy to obtain genotypes of forage legumes which are able to accumulate sulphur amino acids to high levels. As a first step, L. corniculatus plants expressing γ-zein:KDEL in the leaves were obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026735106843
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  • 53
    Electronic Resource
    Electronic Resource
    Binding of cell type-specific nuclear proteins to the 5′-flanking region of maize C4 phosphoenolpyruvate carboxylase gene confers its differential transcription in mesophyll cells (2000)
    Springer
    Plant molecular biology 44 (2000), S. 543-557 
    Details
    ISSN: 1573-5028
    Keywords: C4 photosynthesis ; maize ; phosphoenolpyruvate carboxylase ; transgenic plant ; transcription ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract C4-type phosphenolpyruvate carboxylase (C4PEPC) acts as a primary carbon assimilatory enzyme in the C4 photosynthetic pathway. The maize C4PEPC gene (C4Ppc1) is specifically expressed in mesophyll cells (MC) of light-grown leaves, but the molecular mechanism responsible for its cell type-specific expression has not been characterized. In this study, we introduced a chimeric maize C4Ppc1 5′-flanking region/β-glucuronidase (GUS) gene into maize plants by Agrobacterium-mediated transformation. Activity assay and histochemical staining showed that GUS is almost exclusively localized in leaf MC of transgenic maize plants. This observation suggests that the introduced 5′ region of maize C4Ppc1 contains the necessary cis element(s) for its specific expression in MC. Next, we investigated whether the 5′ region of the maize gene interacts with nuclear proteins in a cell type-specific manner. By gel shift assays with nuclear extracts prepared from MC or bundle sheath cells (BSC), cell type-specific DNA-protein interactions were detected: nuclear factors PEPIb and PEPIc are specific to MC whereas PEPIa and PEPIIa are specific to BSC. Light alters the binding activity of these factors. These interactions were not detected in the assay with nuclear extract prepared from root, or competed out by oligonucleotides corresponding to the binding sites for the maize nuclear protein, PEP-I, which is known to bind specifically to the promoter region of C4Ppc1. The results suggest that novel cell type-specific positive and negative nuclear factors bind to the maize C4Ppc1 5′-flanking region and regulate its differential transcription in MC in a light-dependent manner.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026565027772
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  • 54
    Electronic Resource
    Electronic Resource
    Molecular characterization of quinolinate phosphoribosyltransferase (QPRTase) in Nicotiana (2000)
    Springer
    Plant molecular biology 44 (2000), S. 603-617 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; nicotinic acid ; pyridine alkaloids ; secondary metabolism ; polyploidy ; wound-induced
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Quinolate acid phosphoribosyltransferase (QPRTase), a key enzyme in nicotinamide adenine dinucleotide (NAD) biosynthesis, also plays an important role in ensuring nicotinic acid is available for the synthesis of defensive pyridine alkaloids in Nicotiana species. In this study, cDNAs for QPRTase were characterized from N. rustica and N. tabacum. Deduced proteins from both cDNAs are almost identical and contain a 24 amino acid N-terminal extension, not reported in other QPRTases, that has characteristics of a mitochondrial targeting sequence. In N. tabacum and N. sylvestris, both of which contain nicotine as the major pyridine alkaloid, QPRTase transcript was detected in roots, the site of nicotine synthesis, but not in leaves. QPRTase transcript levels increased markedly in roots of both species 12–24 h after damage to aerial tissues, with a concomitant rise in transcript levels of putrescine N-methyltransferase (PMT), another key enzyme in nicotine biosynthesis. In N. glauca, however, in which anabasine represents the major pyridine alkaloid, QPRTase transcript was detected in both leaf and root tissues. Moreover, wound induction of QPRTase but not PMT was observed in leaf tissues, and not in roots, 12–24 h after wounding. Southern analysis of genomic DNA from the Nicotiana species noted above, and also several others from within the genus, suggested that QPRTase is encoded by a small gene family in all the species investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026590521318
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  • 55
    Electronic Resource
    Electronic Resource
    Hexose transporters of tomato: molecular cloning, expression analysis and functional characterization (2000)
    Springer
    Plant molecular biology 44 (2000), S. 687-697 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; heterologous expression ; H+/hexose symporter ; Lycopersicon esculentum ; quantitative PCR ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A full-length (LeHT2) and two partial (LeHT1 and LeHT3) cDNA clones, encoding hexose transporters, were isolated from tomato (Lycopersicon esculentum) fruit and flower cDNA libraries. Southern blot analysis confirmed the presence of a gene family of hexose transporters in tomato consisting of at least three members. The full-length cDNA (LeHT2) encodes a protein of 523 amino acids, with a calculated molecular mass of 57.6 kDa. The predicted protein has 12 putative membrane-spanning domains and belongs to the Major Facilitator Superfamily of membrane carriers. The three clones encode polypeptides that are homologous to other plant monosaccharide transporters and contain conserved amino acid motifs characteristic of this superfamily. Expression of the three genes in different organs of tomato was investigated by quantitative PCR. LeHT1 and LeHT3 are expressed predominantly in sink tissues, with both genes showing highest expression in young fruit and root tips. LeHT2 is expressed at relatively high levels in source leaves and certain sink tissues such as flowers. LeHT2 was functionally expressed in a hexose transport-deficient mutant (RE700A) of Saccharomyces cerevisiae. LeHT2-dependent transport of glucose in RE700A exhibited properties consistent with the operation of an energy-coupled transporter and probably a H+/hexose symporter. The K m of the symporter for glucose is 45 μM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026578506625
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  • 56
    Electronic Resource
    Electronic Resource
    Spatial and temporal patterns of GUS expression directed by 5′ regions of the Arabidopsis thaliana farnesyl diphosphate synthase genes FPS1 and FPS2 (2000)
    Springer
    Plant molecular biology 44 (2000), S. 747-758 
    Details
    ISSN: 1573-5028
    Keywords: Arabidopsis thaliana ; β-glucuronidase (GUS) reporter gene ; farnesyl diphosphate synthase ; gene expression ; isoprenoids ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Farnesyl diphosphate synthase (FPS), the enzyme that catalyses the synthesis of farnesyl diphosphate (FPP) from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), is considered a regulatory enzyme of plant isoprenoid biosynthesis. The promoter regions of the FPS1 and FPS2 genes controlling the expression of isoforms FPS1S and FPS2, respectively, were fused to the β-glucuronidase (GUS) reporter gene and introduced into Arabidopsis thaliana plants. The FPS1S:GUS gene is widely expressed in all plant tissues throughout development, thus supporting a role for FPS1S in the synthesis of isoprenoids serving basic plant cell functions. In contrast, the FPS2:GUS gene shows a pattern of expression restricted to specific organs at particular stages of development. The highest levels of GUS activity are detected in flowers, especially in pollen grains, from the early stages of flower development. After pollination, much lower levels of GUS activity are detected in the rest of floral organs, with the exception of the ovary valves, which remain unstained throughout flower development. GUS activity is also detected in developing and mature seeds. In roots, GUS expression is primarily detected at sites of lateral root initiation and in junctions between primary and secondary roots. No GUS activity is detected in root apical meristems. GUS expression is also observed in junctions between primary and secondary stems. Overall, the pattern of expression of FPS2:GUS suggests a role for FPS2 in the synthesis of particular isoprenoids with specialized functions. Functional FPS2 gene promoter deletion analysis in transfected protoplasts and transgenic A. thaliana plants indicate that all the cis-acting elements required to establish the full pattern of expression of the FPS2 gene are contained in a short region extending from positions −111 to +65. The potential regulatory role of specific sequences within this region is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026588708849
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  • 57
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    Electronic Resource
    Biosynthesis and secretion of recombinant human growth hormone in Pichia pastoris (2000)
    Springer
    Biotechnology letters 22 (2000), S. 109-114 
    Details
    ISSN: 1573-6776
    Keywords: alcohol oxidase ; gene expression ; human growth hormone ; Pichia pastoris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Mature human growth hormone (hGH) cDNA was cloned by homologous recombination into the yeast Pichia pastoris genome. The hGH gene expression was placed under the control of the methanol-inducible alcohol oxidase 1 (AOX1) gene promoter and the Saccharomyces cerevisiae α-factor signal sequence to direct the secretion of recombinant human growth hormone (rhGH) into the growth medium. O2-limited induction of recombinant yeast strains in shake tubes with 3 ml of culture medium produced up to 11 mg rhGH l−1, while high cell density cultures using a 2-l bioreactor produced about 49 mg rhGH l−1 achieving 40% of total protein of the culture medium supernatant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005675920451
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  • 58
    Electronic Resource
    Electronic Resource
    PCR cloning of Pseudomonas resinovorans polyhydroxyalkanoate biosynthesis genes and expression in Escherichia coli (2000)
    Springer
    Biotechnology letters 22 (2000), S. 789-794 
    Details
    ISSN: 1573-6776
    Keywords: gene expression ; PCR cloning ; pha genes ; polyhydroxyalkanoates ; Pseudomonas resinovorans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A ca. 5.5-kb region of Pseudomonas resinovorans genome containing the polyhydroxyalkanoate (PHA) biosynthesis locus was sequenced. Three complete open-reading-frames (ORFs), i.e., phaC1 Pr, phaZ Pr, and phaC2 Pr, were identified. Using this sequence information, phaC1 Pr was PCR-cloned from P. resinovorans genomic DNA and expressed in E. coli as shown by a Nile Red plate assay and gas chromatography/mass spectrometric analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005614209342
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  • 59
    Electronic Resource
    Electronic Resource
    Gene expression in allergenic pollen (2000)
    Springer
    Aerobiologia 16 (2000), S. 331-334 
    Details
    ISSN: 1573-3025
    Keywords: allergenic pollen ; gene expression ; molecular biology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The molecular mechanism of gene expression for pollen specificity is not yet fully known. However, it is an exciting area with great potential and has a wide scope of application in the field of molecular biology, breeding systems, biotechnology etc. The main aim of this write-up is to review some of the interesting achievements made through studies like gene expression in allergic pollen and the research which will make a way towards practical application of pollen molecular biology in identifying and isolating the genes responsible for all allergic disorders reported among various individuals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026515820294
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  • 60
    Electronic Resource
    Electronic Resource
    Comparison of RAP-PCR analysis of gene expression in fresh and immortalised rat hepatocyte cell lines (2000)
    Springer
    Cytotechnology 34 (2000), S. 159-163 
    Details
    ISSN: 1573-0778
    Keywords: gene expression ; immortalised hepatocytes ; RAP-PCR ; RT-PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Primary rat hepatocytes dedifferentiate rapidly losing theactivities of the drug metabolising enzymes involved in thedetoxification of xenobiotics in the liver. An alternativeapproach to using primary hepatocytes for toxicity testing isthe development of immortalised hepatocyte cell lines via thetransfection of primary hepatocytes with SV40 DNA. In order toassess the suitability of immortalised lines as an alternativeto primary cell cultures we have used RNA arbitrarily primedpolymerase chain reaction to compare gene expression inimmortalised rat hepatocyte cell lines with that in primary rathepatocytes. We have found that differences exist in the RNAtranscripts between fresh and immortalised hepatocyteshighlighting RNA arbitrarily primed polymerase chain reaction asa useful screening method for identifying immortalised lineswhich retain the most `normal' phenotype in relation to theprimary cells from which they originated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008159912634
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  • 61
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    Electronic Resource
    Detection and cDNA cloning of H-strand mitochondrial regulatory region RNAs in cultured human cells and human tissues (2000)
    Springer
    Cytotechnology 33 (2000), S. 175-188 
    Details
    ISSN: 1573-0778
    Keywords: cDNA ; differentiation ; gene expression ; growth ; humancells ; human tissues ; mitochondrial DNA ; mitochondrial RNA ; polyadenylated RNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In the mitochondrion, essential genetic elements for replication and transcription are mostly housed within a shortsegment of its DNA located between tRNAPhe and tRNAPro genes, which is called mitochondrial regulatoryregion (mrr). RNAs are known to be transcribed from mrr, thestructures and the functions of which are yet to be fullycharacterized.We detected ca. 1.3 kb H-strand transcripts of mrr (mrrH-RNAs),and 0.2 kb L-strand transcripts of mrr (mrrL-RNAs) in varioushuman cultured cells and tissues using double stranded mrrDNAprobes. The steady state levels of mrrL-RNAs were generally highin cultured cells, while they varied among tissues. On the otherhand, the levels of mrrH-RNAs varied among tissues and amongcultured cells. A tendency was observed in these cells andtissues that a high level of mrrL-RNA is associated with cellproliferation, and a high level of mrrH-RNA withdifferentiation. Several cDNA clones to 1.3 kb mrrH-RNA were obtained from humanskeletal muscle polyadenylated RNAs. The 5′ terminus of the 1.3 kb RNA was determined to be at nucleotide position 15953 whichis immediately downstream of tRNAThr sequence.Polyadenylation site for most of the clones was demonstrated tobe at nucleotide position 576 which is immediately upstream oftRNAPhe sequence. The longest cDNA insert obtained was 1177 bps long spanning from nucleotide positions 15969 to 576 which could code for a peptide of 76 amino acids. The cDNAs isolatedhere are the first cDNA clones reported to human mrrH-RNAs.These results, together with previous results, furthersubstantiate that polyadenylated mrrH- and mrrL-RNAs are commonly present at varying levels among human tissues andcells. The 3′ end sequences of the cloned mrrH-cDNA provideswith insights into the mechanisms of transcription termination.The cDNA clones will provide tools to further the study of thefunction of mrr RNAs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008154027997
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  • 62
    Electronic Resource
    Electronic Resource
    Determination of Pollutant Phenols by Capillary High-Performance Liquid Chromatography with UV Detection (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 367-372 
    Details
    ISSN: 0935-6304
    Keywords: Capillary HPLC ; gradient elution ; temperature programming ; phenolic compounds ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---This paper describes a liquid chromatographic method using a reversed phase capillary column coupled to an UV detector for the quantitation of thirteen pollutant phenols. Chromatographic separation was carried out with gradient elution at 25.0 ± 0.1°C. The two major anisocratic elution modes (gradient elution and temperature programming) were evaluated. The detection limit range was 10-81 pg (100 nL injected). The chromatographic method combined with liquid-liquid extraction was applied to analysis of these compounds in river water. Recoveries of 75-103% were achieved for most of them.
    Additional Material: 5 Ill.
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  • 63
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    Electronic Resource
    Use of Capillary Supercritical Fluid Chromatography in the Analysis of Zinc Dialkyldithiophosphates (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 389-392 
    Details
    ISSN: 0935-6304
    Keywords: Capillary SFC ; zinc dialkyldithiophosphates ; lubricating oils ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract
    Additional Material: 5 Ill.
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  • 64
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    Electronic Resource
    Application of Supercritical Fluid Chromatography to the Analysis of Waxes in Objects of Art (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 393-396 
    Details
    ISSN: 0935-6304
    Keywords: Supercritical fluid chromatography (SFC) ; micropacked capillary columns ; waxes ; restoring ; objects of art ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract
    Additional Material: 2 Ill.
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  • 65
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    Electronic Resource
    Identification of Free and Glycosidically Bound Volatiles and Glycosides by Capillary GC and Capillary GC-MS in “Lulo del Chocó” (Solanum topiro) (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 379-385 
    Details
    ISSN: 0935-6304
    Keywords: Aroma ; “lulo del Chocó” ; Solanum topiro ; volatiles ; glycosidically bound volatiles ; glycoside TFA derivatives ; enantioselective gas chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The volatile constituents of lulo del Chocó (Solanum topiro) fruit pulp obtained by liquid-liquid extraction were analyzed by capillary GC and capillary GC-MS. In total, 30 components were identified with methyl salicylate, hexadecanoic acid, hexanal, guaiacol, ethyl butanoate, and ethyl acetate being the major components. Chirospecific MDGC analysis revealed the predominance of (R)-ethyl-3-hydroxybutanoate (ee 40%) and the presence of racemic mixtures both of δ-octalactone and of δ-decalactone. For γ-hexalactone, γ-octalactone, and γ-decalactone enantiomeric distributions of 22.4 : 77.6, 22.9 : 77.1, and 20.0 : 80.0, (R) : (S), respectively, were determined. Glycosidically bound aroma compounds were identified by capillary GC and capillary GC-MS after isolation of the glycosidic fraction obtained by Amberlite XAD-2 adsorption and methanol elution followed by hydrolysis with a commercial pectinase enzyme. In total 13 bound aroma compounds (aglycones) were identified. These aglycones mainly consisted of compounds exhibiting aromatic structures. Additionally, with the aid of capillary GC and capillary GC-MS (EI and NCI) of trifluoroacetylated derivatives we identified eight glucosides: the novel 3,6-epoxy-7-megastigmen-5,9-diol β-D-glucopyranoside and the hexyl, benzyl, linalyl oxide (furanic), 2-phenylethyl, vomifolyl (isomer 1), (6S,9R)-vomifolyl, and scopoletin β-D-glucopyranosides.
    Additional Material: 1 Ill.
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  • 66
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    Electronic Resource
    System Peaks of Cyclodextrins in Capillary Electrophoresis (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 409-412 
    Details
    ISSN: 0935-6304
    Keywords: Cyclodextrin ; capillary electrophoresis ; system peak ; CHES 1 ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Using a running buffer containing cyclodextrins (CDs) and 2-[N-cyclohexylamino]-ethanesulfonic acid (CHES), positive system peaks were observed in the analysis of a ganglioside mixture by CE-UV. These system peaks were related to CDs in the running buffer because these peaks were also detected when a plug of solution devoid of CDs but having the same CHES concentration and pH as the running buffer was injected. Neutral CDs were separated owing to the formation of inclusion complexes with the anionic CHES ion. One possible explanation for the positive system peaks is that the anionic CD-CHES inclusion complex is displaced by co-ions with higher UV absorptivity.
    Additional Material: 3 Ill.
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  • 67
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    Liquid Chromatography of Unstable Zinc Dithiocarbamates. Application to Rubber Gloves Analysis (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 565-566 
    Details
    ISSN: 0935-6304
    Keywords: Liquid chromatography ; zinc dithiocarbamate ; vulcanization accelerator ; rubber gloves ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 68
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    Electronic Resource
    Characteristic Stationary Phase Constants for Two Popular Open-Tubular Column Stationary Phases for Gas Chromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 603-608 
    Details
    ISSN: 0935-6304
    Keywords: Solvation parameter model ; ystem constants for poly(dimethyldiphenylsiloxane) HP-5 and poly(ethylene glycol) HP-INNOWax stationary phases ; temperature ; molecular interaction ; retention models ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 69
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    Electronic Resource
    Determination of Cinnamomi Constituents by High-performance Liquid Chromatography and Capillary Electrophoresis (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 561-564 
    Details
    ISSN: 0935-6304
    Keywords: Retention factors ; Cinnamomi ramulus ; high-performance liquid chromatography ; capillary electrophoresis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 3 Ill.
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  • 70
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    Ion Chromatography of Inorganic Anions on Graphitic Carbon as the Stationary Phase (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 590-594 
    Details
    ISSN: 0935-6304
    Keywords: Ion chromatography ; graphitic carbon stationary phases ; anions ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Inorganic anions could be separated on porous graphitic carbon stationary phases in ion chromatography. Ion exchange between eluent anions and sample anions on the stationary phase was confirmed by the retention behavior and the possibility of indirect photometric detection. The elution order of anions was different from that observed for commercially available anion exchangers. Chloride, nitrate, and sulfate contained in tap water could be determined in 7 min.
    Additional Material: 6 Ill.
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  • 71
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    Solid-Phase Microextraction of Pyrethroid Pesticides from Water at Low and Sub-ppt Levels at Different Temperatures (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 485-488 
    Details
    ISSN: 0935-6304
    Keywords: Pyrethroids ; solid-phase microextraction ; water analysis ; temperature ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Synthetic pyrethroids are increasingly being used for insect control on field crops because of their advantageous environmental properties such as short field life, broad spectrum of insecticide activity, and relatively low mammalian toxicity. In the present work, experimental conditions were optimized for trace analysis of pyrethroids in water by using solid-phase microextraction followed by capillary gas chromatography. Effects of temperature, SPME-fiber diameter, and matrix were studied. SPME used off-line with a gas chromatograph electron-capture detection (GC-ECD) showed a linear response over a wide concentration range. Our results showed a strong temperature effect on pyrethroid extraction yield. The detection limit after 5 min of SPME-fiber exposure to the samples changed from 1 ppb (at 30°C) to 0.1 ppt (at 90°C), which is a 10000 increase in pyrethroid detection. The standard deviations of the analyte peak area ratios were typically in the range of 1-7% at 30°C and of 3 to 15% at 90°C. Best conditions for pyrethroids analysis were achieved using high temperature solution and a 100 μm polydimethylsiloxane fiber. No matrix (river water) influence was observed on detection of the investigated pyrethroids.
    Additional Material: 6 Ill.
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  • 72
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    Microfabricated Monolith Columns for Liquid Chromatography. Sculpting Supports for Liquid Chromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 19-26 
    Details
    ISSN: 0935-6304
    Keywords: Microfabrication ; monolith ; electrochromatography ; peptides ; reactive ion etching ; reversed phase ; nanocolumns ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monolith columns are generally fabricated by polymerization of monomers within a column. This paper reviews an alternative strategy in which the bed is microfabricated in an inorganic material by ablation. Channels of 1.5 μm width and 10 μm depth were sculpted in quartz by deep reaction ion etching. Using this approach chromatographic beds were constructed in which cubic support structures were created and arranged in rows to mimic particles in a conventional column. Beds ranging from hundreds of thousands to millions of “particles” with volumes of 15 nL to 15 μL were produced. Columns that had been derivatized with an octadecyl silane stationary phase were used to separate both low molecular weight analytes and peptides in the CEC mode. Plate height in the CEC mode was 1.2 μm at maximum efficiency.
    Additional Material: 9 Ill.
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  • 73
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    Dynamic Capacity Studies of CIM (Convective Interaction Media)® Monolithic Columns (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 39-43 
    Details
    ISSN: 0935-6304
    Keywords: Monoliths ; CIM® monolithic column ; dynamic binding capacity ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The characterization of CIM® DEAE monolithic columns in terms of dynamic binding capacity is presented in this paper. Breakthrough experiments were performed for capacity determination. Bovine serum albumin (BSA) was used as a model protein. It is shown that CIM® monolithic columns have good batch-to-batch reproducibility as well as long-term stability. The experiments performed under different linear velocities demonstrated that the dynamic capacity is unaffected at least up to a linear velocity of 2450 cm/h. Furthermore, the breakthrough curve slope is constant, indicating that the capacity would remain constant at even higher linear velocities. The adsorption isotherm of BSA dissolved in 20 mM Tris-HCl buffer shows a constant capacity of around 30 mg/mL of support down to a concentration of 20 μg/mL. The capacity is substantially influenced by the ionic strength; however, 20% of the maximal capacity is still preserved at 0.3 M NaCl.
    Additional Material: 5 Ill.
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  • 74
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    Affinity Chromatography of Human Blood Coagulation Factor VIII on Monoliths with Peptides from a Combinatorial Library (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 47-58 
    Details
    ISSN: 0935-6304
    Keywords: Monolith ; factor VIII ; affinity chromatography ; combinatorial peptide library ; peptide synthesis ; recombinant proteins ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: FVIII is a very complex molecule of great therapeutic significance. It is purified by a sequence of chromatographic steps including immunoaffinity chromatography. A peptide affinity chromatography method has been developed using peptides derived from a combinatorial library. Spot technology using cellulose sheets has been applied for this purpose. The dual positional scanning strategy was used for identification of the amino acids in random positions. Approximately 5000 possible candidates found in the first screening round were reduced to a panel of 36. Six candidates have been selected empirically. Five peptides seem to be directed against the light chain of FVIII, one peptide seems to be directed against the heavy chain. The peptides have been immobilized on conventional beaded material and CIM polymethacrylate monoliths. Much better performance with respect to capacity and selectivity has been observed with the monolithic material. Exposure of the ligand and its ensuing accessibility are responsible for these properties.
    Additional Material: 8 Ill.
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  • 75
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    Capillary Electrochromatography with Monolithic Poly(styrene-co-divinylbenzene-co-methacrylic acid) as the Stationary Phase (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 67-72 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; monolithic column ; electroosmotic flow ; retention mechanism ; aromatic compound ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new kind of monolithic capillary electrochromatography column with poly(styrene-co-divinylbenzene-co-methacrylic acid) as the stationary phase has been developed. The stationary phase was found to be porous by scanning electron microscopy and the composition of the continuous bed was proved by IR spectroscopy to be the ternary polymer of styrene, divinylbenzene, and methacrylic acid. The effects of operating parameters, such as voltage, electrolyte, and organic modifier concentration in the mobile phase on electroosmotic flow were studied systematically. The retention mechanism of neutral solutes on such a column proved to be similar to that of reversed-phase high performance liquid chromatography. In addition, fast analyses of phenols, chlorobenzenes, anilines, isomeric compounds of phenylenediamine and alkylbenzenes within 4.5 min were achieved.
    Additional Material: 9 Ill.
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  • 76
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    Continuous-Bed Columns Containing Sol-Gel Bonded Packing Materials for Capillary Electrochromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 73-80 
    Details
    ISSN: 0935-6304
    Keywords: Continuous-bed ; sol-gel ; octadecylsilica ; mixed-mode stationary phase ; large-pore ; column technology ; capillary electrochromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Sol-gel bonded packing materials in continuous-bed columns have been prepared for capillary electrochromatography (CEC). Three packing materials were investigated: small-pore Spherisorb ODS1 (3 μm, 80 Å) with octadecyl as stationary phase, small-pore mixed-mode Spherisorb ODS/SCX (3 μm, 80 Å) with octadecyl and propyl sulfonic acid as stationary phases, and large-pore Nucleosil ODS (7 μm, 1 400 Å) with octadecyl as stationary phase. The characteristics of these columns were compared in terms of electroosmotic flow, efficiency, inertness, and retention factors. In contrast to columns containing sol-gel bonded ODS, columns containing sol-gel bonded mixed-mode ODS/SCX generated nearly pH independent electroosmotic flow (EOF) over pH 2-9. Columns containing sol-gel bonded large-pore ODS produced nearly three times lower reduced plate height than those containing small-pore ODS. Efficiencies of 220,000 plates per meter and 175,000 plates per meter were obtained from columns containing sol-gel bonded 7 μm, 1 400 Å ODS and columns containing sol-gel bonded 3 μm, 80 Å ODS, respectively, which are among the highest reported efficiencies for continuous-bed columns. In CEC, over one million plates per meter and pH independent EOF are expected from continuous-bed columns containing sol-gel bonded 1.5 μm particles with large pores and mixed-mode stationary phases.
    Additional Material: 11 Ill.
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  • 77
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    Particle Loaded Monolithic Sol-Gel Columns for Capillary Electrochromatography: A New Dimension for High Performance Liquid Chromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 81-88 
    Details
    ISSN: 0935-6304
    Keywords: Monolithic chromatography columns ; capillary electrochromatography (CEC) ; micro high performance liquid chromatography ; sol-gel based columns for chromatography ; fritless capillary chromatography columns ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Particle-loaded (3 μm, octadecylsilica) monolithic sol-gel columns have been prepared and selected characteristics measured. Several electrical properties may be calculated from simple current measurements in the column as a whole. Resistivity in the packed segment is approximately three times that in open segments, resulting in a 60% increase in field strength in the packed regions compared to the capillary with no packing. The surprisingly high specific permeability of these sol-gel columns is characteristic of 8-μm particles, which allows their operation in the microLC mode at pressures as low as 69 kPa where their efficiency is about 50,000 plates per meter and in the CEC mode where efficiency is about 106,000 plates per meter at 5 kV. There is a relatively rapid loss of efficiency with increasing linear velocity beyond 0.2 mm/s in microLC mode, which may be due to additional diffusion processes in the inter-particulate voids. A rapid loss of efficiency above 0.5 mm/s is also observed in the CEC mode, for the same reasons. Chromatographic retention behavior in either separation mode is characteristic of conventional octadecylsilica particles, indicating that analytes have significant access to the surface within the pores of the immobilized bonded phase.
    Additional Material: 6 Ill.
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  • 78
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    Preparation of Fritless Packed Silica Columns for Capillary Electrochromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 89-92 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; packed columns ; fritless columns ; stationary phases ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Fritless packed silica gel columns were prepared using sol-gel technology. A part of a 75 μm i.d. fused silica capillary was filled with a mixture of tetramethoxysilane and poly(ethylene glycol). After gelling at 40°C and heating at 300°C, the resultant silica gel was derivatized with dimethyloctadecylchlorosilane. A scanning electron micrograph of a cross-section of the capillary column showed that the gel took the form of a spherical particle aggregate and adhered to the column inner wall. The column performance was evaluated for electrochromatography using acetonitrile-50 mM HEPES buffer (pH 6.6) (60/40 or 40/60, v/v) as the mobile phase. An electroosmotic flow of 1.0 mm/s was generated with (60/40, v/v) acetonitrile/HEPES buffer at a field strength of 546 V/cm. Using a sol-gel-derived packed column at an electroosmotic flow of 0.5 mm/s, efficiencies of up to 1.1×105 plates/m were obtained for retained solutes.
    Additional Material: 4 Ill.
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  • 79
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    A New Monolithic-Type HPLC Column For Fast Separations (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 93-99 
    Details
    ISSN: 0935-6304
    Keywords: HPLC ; monolithic column ; silica rod column ; fast separations ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The application of a new silica-based, monolithic-type HPLC-column for fast separations is presented. The column is prepared according to a new sol-gel process, which is based on the hydrolysis and polycondensation of alkoxysilanes in the presence of water soluble polymers. The method leads to “rods” made of a single piece of porous silica with a defined pore structure, i. e. macro- and mesopores. The main feature of silica rod columns is a higher total porosity, about 15% higher than of conventional particulate HPLC columns. The resulting column pressure drop is therefore much lower, allowing operation at higher flow rates including flow gradients. Consequently, HPLC analysis can be performed much faster, as it is demonstrated by various applications.
    Additional Material: 9 Ill.
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  • 80
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    Monolithic Stationary Phases for Capillary Electrochromatography Based on Synthetic Polymers: Designs and Applications (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 3-18 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; monolithic columns ; synthetic polymers ; stationary phase ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monolithic materials have quickly become a well-established stationary phase format in the field of capillary electrochromatography (CEC). Both the simplicity of their in situ preparation method and the large variety of readily available chemistries make the monolithic separation media an attractive alternative to capillary columns packed with particulate materials. This review summarizes the contributions of numerous groups working in this rapidly growing area, with a focus on monolithic capillary columns prepared from synthetic polymers. Various approaches employed for the preparation of the monoliths are detailed, and where available, the material properties of the resulting monolithic capillary columns are shown. Their chromatographic performance is demonstrated by numerous separations of different analyte mixtures in variety of modes. Although detailed studies of the effect of polymer properties on the analytical performance of monolithic capillaries remain scarce at this early stage of their development, this review also discusses some important relationships such as the effect of pore size on the separation performance in more detail.
    Additional Material: 16 Ill.
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  • 81
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    Preparative Monolithic Silica Sorbents (PrepRODs™) and Their Use in Preparative Liquid Chromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 100-105 
    Details
    ISSN: 0935-6304
    Keywords: Preparative chromatography ; silica monoliths ; PrepROD™ ; productivity ; SMB-chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The use of monolithic silica sorbents for the isolation of substances by preparative liquid chromatography is demonstrated. Preparative liquid chromatography is recognized as a valuable technique for the isolation and purification of substances in the pharmaceutical and fine chemicals industry. The system technology has meanwhile reached a high standard, and the greatest future improvements are expected to arise from new and improved adsorbents. Monolithic silica sorbents offer some unique features for preparative liquid chromatography. They exhibit high efficiencies even at high flow rates due to their fast convective mass transfer and can therefore be used at very high mobile phase velocities, leading to high productivity and hence to maximum process economy. The benefits of this new type of adsorbent are illustrated for an example in batch-chromatographic mode and an example using the continuous simulated moving bed (SMB) technology.
    Additional Material: 6 Ill.
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  • 82
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    Tailoring Mesopores in Monolithic Macroporous Silica for HPLC (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 106-110 
    Details
    ISSN: 0935-6304
    Keywords: Silica ; monolithic column ; aging ; mesopores ; pore size distribution ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Mesopore formation in silica gels having continuous macropores has been investigated. The macroporous wet silica gel prepared by the sol-gel process including phase separation was aged in a basic solvent making use of hydrolysis of urea in a closed condition. The mesopore structure was finally obtained by subsequent evaporation drying of solvent and heat-treatment at 600°C for 2 h. The dissolution-reprecipitation kinetics at the interfaces between wet gel skeletons and an external solvent affected the size and volume of pores formed within the skeletons. Below 120°C, mesopores suitable for various chromatographic applications have been formed typically within 24 h. On the other hand, at 200°C, the pore size attained the macropore dimensions (〉50 nm), and the whole macroporous morphology was significantly modified.
    Additional Material: 7 Ill.
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  • 83
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    Monolithic Silica Columns for HPLC, Micro-HPLC, and CEC (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 111-116 
    Details
    ISSN: 0935-6304
    Keywords: Monolithic column ; silica monolith ; HPLC ; capillary liquid chromatography ; capillary electrochromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Two types of monolithic silica columns derivatized to form an ODS phase, one prepared in a fused silica capillary (SR-FS) and the other prepared in a mold and clad with an engineering plastic (poly-ether-ether-ketone) (SR-PEEK), were evaluated. The column efficiency and pressure drop were compared with those of a column packed with 5-μm ODS-silica particles and of an ODS-silica monolith prepared in a mold and wrapped with PTFE tubing (SR-PTFE). SR-FS gave a lower pressure drop than a column packed with 5-μm particles by a factor of 20, and a plate height of 20 μm at a linear velocity below 1 mm/s. SR-PEEK showed higher flow-resistance than the other monolithic silica columns, but they still showed a minimum plate height of 8-10 μm and a lower pressure drop than popular commercial columns packed with 5-μm particles. The evaluation of SR-FS columns in a CEC mode showed much higher efficiency than in a pressure-driven mode.
    Additional Material: 6 Ill.
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  • 84
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    Note on the Net Retention Volume in Chromatography with a Real Gas as a Carrier (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 119-126 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; retention volume ; real gas carrier ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The problem of the calculation and interpretation of the net retention volume with a real gas as carrier is revisited. The properties of the carrier are described by a first order virial equation of state. The net retention volume of a solute is related to the mean flow rate of the carrier, therefore determination of the mean flow rate of a real gas carrier is reviewed. It is shown that the mean flow rate cannot be calculated from the mean column pressure. With a real gas carrier the local capacity factor depends on the local pressure of the real gas. The basic relationship between the net retention volume and the function describing this pressure dependence is also reviewed. Precise formulae as well as practical approximations are presented for the calculation of the mean flow rate, of the mean column pressure, and of a representative pressure related to the mean capacity factor.
    Additional Material: 3 Tab.
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  • 85
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    Detection of Polyols by HPLC Coupled with an On-Line Photochemical Oxidation Reactor and Chemiluminescence Detection (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 127-130 
    Details
    ISSN: 0935-6304
    Keywords: Chemiluminescence ; diol compound ; oxalate ; post-column reaction ; ruthenium complex ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---In this paper we propose a new post-column detection method for polyols containing 1,2-diol, 1,3-diol, and saccharides. The polyols are oxidized in a photochemical reactor to yield oxalate with subsequent chemiluminescence detection using [Ru(III)(bpy)3]3+. A mixing solution of eluate and oxidizing reagent is delivered to a reaction coil, which is then irradiated with ultraviolet light to promote the oxidation reaction. The detection limits for 1,2-ethanediol (ethylene glycol) and 1,3-propanediol were 38 pmol and 23 pmol, respectively.
    Additional Material: 5 Ill.
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  • 86
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    Coupled LC-GC-NPD for Determination of Carbazole-Type PANH and Its Application to Personal Exposure Measurement (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 131-137 
    Details
    ISSN: 0935-6304
    Keywords: On-line coupled LC-GC ; nitrogen selective detection ; NPD ; carbazoles ; PANH ; personal exposure measurement ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A coupled LC-GC method for the analysis of carbazole-type PANH has been developed and evaluated. Group separation and isolation of carbazoles from interfering acridines in a complex sample matrix was accomplished by using a back-flush technique and an in situ end-capped dimethylaminopropyl silica column in the HPLC part of the system. On-line injection of the carbazole fraction into the GC column was performed with a loop-type interface utilizing concurrent solvent evaporation technique. An LOD of 1-3 pg of individual carbazole compounds was achieved by nitrogen selective detection using an NPD. The method is shown to be robust and is demonstrated by application to personal exposure measurement in an aluminum reduction plant.
    Additional Material: 4 Ill.
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  • 87
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    Fast Separation of Nucleosides by Capillary Electrochromatography on Non-Endcapped Phenyl-Bonded Silica Phase Using Short-End Injection Method (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 138-142 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; nucleosides ; short-end injection ; phenyl-bonded silica ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The influence of several experimental parameters (pH, ionic strength, organic modifier content of hydro-organic buffer) upon EOF, migration time, and retention factor has been studied in CEC with a phenyl-bonded silica column on a model mixture of five nucleosides. This paper illustrates the current interest in CEC as a method of resolving complex mixtures of neutral and ionic solutes and demonstrates the potential of the short-end injection method as a means of reducing analysis time.
    Additional Material: 4 Ill.
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  • 88
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    Separation of Anthraquinones by Capillary Electrophoresis and High-Performance Liquid Chromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 143-148 
    Details
    ISSN: 0935-6304
    Keywords: Analysis of anthraquinones ; capillary electrophoresis ; high-performance liquid chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The separation and determination of twelve anthraquinones, viz. anthraquinone 1, chrysphanol 2, aloe-emodin 3, alizarin 4, anthraquinone-2-carboxylic acid 5, purpurin 6, sennoside B 7, sennoside A 8, emodin 9, quinalizarin 10, rhein 11, and anthraflavic acid 12, were achieved by capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC). Detection at 260 nm with a buffer solution containing 30 mM sodium borate (adjusted to pH = 10.56 with 0.05N NaOH) and acetonitrile (9 : 1) in CE or with a linear gradient elution containing 20 mM KH2PO4 with 0.05% phosphoric acid (pH = 2.91) and methanol in HPLC was found to be the most suitable approach for this separation. Contents of six components (2, 3, 7, 8, 9, 11) in crude Rhei Rhizoma extract could easily be determined within 39 min by CE or 63 min by HPLC. The effects of buffers on this separation and the validation of the two methods were studied.
    Additional Material: 5 Ill.
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  • 89
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    Capillary Gas Chromatography of Trichlorophenols Using Ammonia as Carrier Gas (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 156-157 
    Details
    ISSN: 0935-6304
    Keywords: Capillary gas chromatography ; trichlorophenols ; ammonia ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 1 Tab.
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  • 90
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    Large Volume Injection in Fast Gas Chromatography with On-Column Injector (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 149-155 
    Details
    ISSN: 0935-6304
    Keywords: Capillary GC ; fast GC ; on-column injection ; narrow-bore column ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---In this work a fast gas chromatography set-up with on-column injection was optimized and evaluated with a model mixture of C8-C28 n-alkanes. Usual injection volumes when using narrow-bore (e. g., 0.1 mm i.d.) analytical columns are ca. 0.1 μL. The presented configuration allows introduction of 10-30-fold larger sample volumes without any distortion of peak shapes. In the set-up a normal-bore retention gap (1 m×0.32 mm i. d.) was coupled to a narrow-bore (4.8 m×0.1 mm i. d.×0.4 μm film thickness) analytical column using a low dead volume column connector. The effects of the experimental conditions such as inlet pressure, sample volume, initial injection temperature, and oven temperature on a peak focusing are discussed. H-u curves for helium and hydrogen are used to compare their suitability for high speed gas chromatography and to show the dependence of separation efficiency on the carrier gas velocity at high inlet pressures. In the fast gas chromatography system a baseline separation of C10-C28 n-alkanes was achieved in less than 3 minutes.
    Additional Material: 4 Ill.
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  • 91
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    Proper Tuning of Comprehensive Two-Dimensional Gas Chromatography (GC×GC) to Optimize the Separation of Complex Oil Fractions (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 182-188 
    Details
    ISSN: 0935-6304
    Keywords: Comprehensive two-dimensional gas chromatography ; GC×GC ; thermal modulation ; oil analysis ; petroleum analysis ; analysis of middle-distillate oil fractions ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Comprehensive two-dimensional gas chromatography (GC×GC) is an utterly suitable separation technique for the analysis of complex samples, such as oil fractions. Once the two columns and the operating conditions are properly tuned, the technique is able to provide a detailed characterization of such materials. Some considerations applying to the tuning of a GC×GC system for a specific separation are presented and discussed. The authors present a number of different column sets and conditions which allow the separation of a non-aromatic hydrocarbon solvent, a kerosene, the light end of a crude oil, and an olefinic fraction, respectively. The highly structured GC×GC chromatograms, together with chemical knowledge about the samples, provide a much more comprehensive characterization of the samples than hitherto possible.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 92
    Electronic Resource
    Electronic Resource
    Comprehensive Two-Dimensional Gas Chromatography with a Rotating Thermal Desorption Modulator and Independently Temperature-Programmable Columns (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 189-196 
    Details
    ISSN: 0935-6304
    Keywords: Comprehensive two-dimensional gas chromatography ; thermal desorption modulator ; temperature programming ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---In comprehensive two-dimensional gas chromatography, two individual separations are coupled by means of a rotating thermal desorption modulator interface. The injection pulse introduced via the interface onto the second column should be as short as possible. Parameters affecting the modulator operation are studied. In the set-up used in this study, the temperature of the second column can be programmed independently from that of the first column. Optimization of the second-dimension separation to minimize peak broadening and maximize resolution is discussed and an elegant approach to determine second-dimension retention times using a non-constant modulation frequency is demonstrated. The high separation power of the comprehensive system is demonstrated by the analysis of technical and biota samples containing chlorinated biphenyls and toxaphene.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 93
    Electronic Resource
    Electronic Resource
    Determination of Oxygenates in Gasoline by GC×GC (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 197-201 
    Details
    ISSN: 0935-6304
    Keywords: Multidimensional gas chromatography ; comprehensive two-dimensional gas chromatography ; GC×GC ; oxygenates ; MTBE ; reformulated gasoline ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Comprehensive two-dimensional gas chromatography (GC×GC) has been applied to the quantitation of oxygenates in reformulated gasoline. Target oxygenates were C1-C4 alcohols, tert-pentanol, methyl tert-butyl ether (MTBE), diisopropyl ether (DIPE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These were separated from the gasoline matrix using a volatility-based selectivity in the first chromatographic dimension, followed by a mixed-phase polarity/shape selectivity in the second dimension. The high resolving power of this stationary phase combination completely separated all oxygenates except DIPE, ETBE, and TAME, which exhibited coelution with other nonpolar gasoline components. Oxygenates quantitation was achieved with the use of an internal standard, an FID detector, and calibration curves. Quantitation results are in good agreement with ASTM and EPA standard methods. When coupled with our previous method for BTEX and aromatics, a single GC×GC method can now quantitate MTBE, alcohols, BTEX, and aromatics in a one-hour analysis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 94
    Electronic Resource
    Electronic Resource
    Biodegradation of Pharmaceutical Residues Investigated by SPE-GC/ITD-MS and On-Line Derivatization (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 474-478 
    Details
    ISSN: 0935-6304
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Solid-phase extraction, on-line derivatization, and measurement by ion trap mass spectrometry (ITD-MS) were used to investigate the biological degradation of pharmaceutical residues (clofibric acid, ibuprofen, diclofenac). The results of the single steps of sample pretreatment and analytical determination are reported. MS/MS measurements were performed on an ITD-MS by selecting collision induced dissociation of the molecular ions (M+) as parent ions to defined daughter ions. A pilot sewage plant and biofilm reactors operating under oxic and anoxic conditions were run as model systems with synthetic sewage water containing 10 to 50 mg/L dissolved organic carbon (DOC) and pharmaceuticals in concentrations of 10 μg/L. Clofibric acid displayed its persistent character in all cases. The pilot sewage plant and the oxic biofilm reactor showed comparable results for diclofenac and ibuprofen, which both were partly degraded. These results can explain the occurrence of these substances in sewage effluents and in the aquatic environment. A high degree of degradation was found especially for ibuprofen in the oxic biofilm reactor, which was attributed to adaptation of the biofilm to the residue. Two metabolites of ibuprofen could be identified on the basis of their mass spectra and comparison with literature data, viz. hydroxyibuprofen and carboxyibuprofen.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 95
    Electronic Resource
    Electronic Resource
    Characterization of Polydimethylsiloxanes Using an Off-Line Combination of Supercritical Fluid Chromatography with Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 502-506 
    Details
    ISSN: 0935-6304
    Keywords: Silicone oil ; supercritical fluid chromatography (SFC) ; micropacked columns ; MALDI-TOF ; GC/MS ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 96
    Electronic Resource
    Electronic Resource
    Separation and Detection of Metal Ions in Ecological Samples by Capillary Zone Electrophoresis with Indirect UV Detection (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 511-514 
    Details
    ISSN: 0935-6304
    Keywords: CZE ; indirect UV detection ; metal ions ; ecological samples ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 97
    Electronic Resource
    Electronic Resource
    Solventless Sample Preparation Techniques in Environmental Analysis (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 297-303 
    Details
    ISSN: 0935-6304
    Keywords: Sample preparation ; gas extraction techniques ; membrane-type techniques ; water analysis ; soil analysis ; gas chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---This review focuses on the role of so-called solventless methods of sample preparation in contemporary environmental analysis. The basic classification of this group of methods as well as the principal features and advantages of the techniques in current use are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 98
    Electronic Resource
    Electronic Resource
    Comparison of Thermal Sweeper and Cryogenic Modulator Technology for Comprehensive Gas Chromatography (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 253-258 
    Details
    ISSN: 0935-6304
    Keywords: Comprehensive gas chromatography ; cryogenic modulation ; semi-volatile aromatics ; thermal sweeper ; peak widths ; peak asymmetries ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The two current technologies for achieving comprehensive gas chromatography (GC×GC) - the thermal sweeper and the cryogenic modulator - are compared in an interlaboratory study using a multicomponent semi-volatile aromatic compound sample. The same column set (phases, film thickness, dimensions of columns) and conditions of oven temperature program were used. Carrier gas flow settings however were different for the data reported here. The thermal sweeper has a longer overall length due to the extra ca. 30 cm length of narrow bore tubing used for the modulator/accumulator section. Data reveal that the two methods behave in an analogous manner in respect of delivering GC×GC results, with key peak parameters of peak widths and symmetry measures showing good correlation. Retention time dissimilarity on the first dimension columns in the two systems arises from different flow rates used, however the second column retention is similar, and this is due to the resulting different elution temperatures that peaks elute on the first dimension in each system. Overall, the two approaches to GC×GC appear to produce equivalent results within the scope of the application studied. Each system does have its experimental limitations; the thermal sweeper has what may be called a ‘thick film effect’, where at high temperature it can be difficult to sufficiently trap the migrating bands in the accumulator column, and the pulsing of solutes in the cryogenic system may suffer from a ‘thick wall effect’ if a column with too thick a wall dimension is used at low oven temperature.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 99
    Electronic Resource
    Electronic Resource
    Is Multidimensional High Performance Liquid Chromatography (HPLC) an Alternative in Protein Analysis to 2D Gel Electrophoresis? (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 259-265 
    Details
    ISSN: 0935-6304
    Keywords: Proteomics ; protein analysis ; multidimensional HPLC ; ion-exchange chromatography ; reversed phase chromatography ; comprehensive HPLC ; two-dimensional HPLC ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The interactive modes of High Performance Liquid Chromatography (HPLC) of proteins provide a platform for the construction of a multidimensional HPLC system coupled to mass spectrometry. We present a system composed of both anion and cation exchanger columns, in the first dimension, and n-octadecyl bonded 1.5 μm nonporous silica columns in the second dimension. Both columns are operated under gradient conditions. A system suitability test with standard proteins showed that the total analysis can be performed within about 20 minutes. The fractions taken from the ion exchanger column are directly analyzed within one minute on the reversed phase column at a high flow rate. Two reversed phase columns are applied and operated alternatively: while the first column performs the separation within one minute, the analytes leaving the first dimension are enriched in an on-column focusing mode on top of the second column. The sample clean-up and enrichment is performed on a novel type of restricted access cation exchanger column with internal sulfonic acid groups and external diol groups. The columns exhibit a molecular weight exclusion limit for globular proteins of about 15 kDa. Our next studies will be directed towards the analysis of proteins and peptides from extracts of fibroblasts.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    Fiber Conditioners for Solid Phase Microextraction: Design, Testing, and Application (2000)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 23 (2000), S. 343-347 
    Details
    ISSN: 0935-6304
    Keywords: SPME ; desorption ; fiber conditioning ; field sampling ; sample preparation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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