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  • wheat  (338)
  • gene expression  (315)
  • Springer  (651)
  • Cambridge University Press
  • 1995-1999  (550)
  • 1980-1984  (64)
  • 1975-1979  (37)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 74 (1995), S. 115-119 
    ISSN: 1570-7458
    Keywords: wheat ; aphids ; hydroxamic acids ; DIMBOA ; DIMBOA-glucoside ; EPG ; electrical penetration graph ; feeding deterrents ; antixenosis ; plant resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Feeding behaviour of five species of cereal aphids in wheat seedlings differing in hydroxamic acid (Hx) levels, was monitored via electrical penetration graphs (EPG). Aphid species could be grouped as sensitive to the feeding deterrent effect of Hx in the seedlings (Rhopalosiphum padi, Schizaphis graminum, Sitobion avenae, andMetopolophium dirhodum) or insensitive to them (Rhopalosiphum maidis). However, when feeding behaviour was studied in artificial diets containing Hx, all species were equally sensitive to Hx. The behavour ofR. maidis was further compared with that ofR. padi through detailed EPG analysis. It was found that the insensitivity ofR. maidis to Hx in seedlings may be due to a feeding strategy avoiding contact with the compounds by decreasing the number of cellular punctures in live tissues other than sieve elements during its way to the phloem.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 74 (1995), S. 283-294 
    ISSN: 1570-7458
    Keywords: hypersensitivity ; Hessian fly ; plant resistance ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hessian flyMayetiola destructor (Say) larvae are able to obtain food from their host plant without inflicting mechanical damage to the plant surface, apparently by secreting substances which elicit release of nutrients from plant cells surrounding the feeding site. Cells of fully susceptible plants retain their normal appearances, while in resistant plants extensive areas of cellular collapse occur. These responses indicate that hypersensitivity is the basis of wheat's resistance to the Hessian fly. The fly's feeding mechanism more closely resembles that of a pathogen than of a phytophagous insect; correspondingly, both the genetic relationship and resistance mechanism of the host plant to the parasite are of the sorts commonly associated with bacterial and fungal pathogens.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 93 (1999), S. 227-230 
    ISSN: 1570-7458
    Keywords: Rhopalosiphum padi ; cereal aphids ; wheat ; induced responses ; feeding site
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 92 (1999), S. 157-164 
    ISSN: 1570-7458
    Keywords: plant resistance ; antibiosis ; tolerance ; antixenosis ; Russian wheat aphid ; wheat ; Homoptera ; Aphididae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Russian wheat aphid, Diuraphis noxia (Mordvilko), is one of the most important aphid pests of wheat, Triticum aestivum L., worldwide. Among the various pest management options, plant resistance is an economical management tactic to control D. noxia in cereal crops such as wheat. Researchers have identified D. noxia resistant germplasm and it has been incorporated into wheat. This study compared D. noxia resistance between the ‘Betta’ wheat isolines Betta-Dn1, Betta-Dn2, and Betta-Dn5 and their corresponding donor gene plant introduction (PI) lines PI 137739 (Dn1), PI 262660 (Dn2), and PI 294994 (Dn5). Although the Betta isolines and PI lines showed D. noxia resistance when compared with Betta wheat, the degree of resistance in the isolines to D. noxia was different from their corresponding PI donors. Aphid number, aphid fecundity, and biomass per aphid were not different between Betta-Dn1 and PI 137739 or Betta-Dn2 and PI 262660; however, the same parameters were significantly lower on PI 294994 compared with Betta-Dn5. This indicated that aphid resistance in PI 137739 and PI 262660 was probably governed by a single dominant gene, while the resistance in PI 294994 was controlled by more than one gene. Additionally, plant biomass reduction was aphid density dependent, which suggested that use of appropriate aphid infestation level is important when using plant biomass reduction as an indicator of resistance. Plant resistance categorization showed that there was no detectable difference in antixenosis among the seven lines evaluated. However, the higher aphid fecundity observed on PI 262660 compared with PI 137739 and PI 294994, in addition to no significant differences among the three PIs in plant biomass reduction, suggested PI 262660 was a tolerant line, while PI 137739 and PI 294994 were antibiotic lines. Plant tolerance could not be elucidated among the three Betta isolines using aphid fecundity and plant biomass reduction as indicators.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 89 (1998), S. 111-118 
    ISSN: 1570-7458
    Keywords: leaf surface wax ; probing behavior ; nymphoposition ; Russian wheat aphid ; wheat ; barley ; oat ; Homoptera ; Aphididae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of cereal leaf surface wax on Diuraphis noxia (Mordvilko), the Russian wheat aphid, probing behavior and nymphoposition was evaluated. Ultrastructure of leaf epicuticular wax from wheat (Triticum aestivum L.) c.v. ‘Arapahoe’ and ‘Halt’ was different from barley (Hordeum vulgare L.) c.v. ‘Morex’, and oat (Avena sativa L.) c.v. ‘Border’. Both wheat cultivars had similar rod-shaped epicuticular wax, while barley and oat plants had flakes. The chemical composition comparison of gas chromatograms also indicated that the extract of the two wheat cultivars had similar pattern of peaks, while the barley and oat leaves had similar peaks. Cereal variety significantly affected aphid probing behavior (P 〈 0.05), but wax removal using ethyl ether swab did not (P 〈 0.05). Aphids initiated significantly more probes on Border oat leaves than on Morex barley irrespective of wax removal, although total probing duration per aphid was not significantly different among the four cereals examined. Accumulative salivation duration per aphid on oat leaves with wax was significantly longer than other cereal leaves with wax, while accumulative ingestion duration per aphid on Arapahoe wheat and Morex barley was significantly longer than on oat. Nymphoposition of D. noxia on cereal leaves maintained on the benzimidazole-agar medium showed that aphids produced a greater number of nymphs on Morex barley and less on Border oat leaves, although wax removal did not affect aphid nymphoposition. Removal of leaf epicuticular waxes from the 4 cereal genotypes using ethyl ether swab indicated that the influence of wax on plant resistance to D. noxia probing and reproduction was limited. Morex barley was the most favorable, while Border oat was the least favorable cereal host of D. noxia.
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  • 6
    ISSN: 1570-7458
    Keywords: sieve element ; salivation ; aphid ; plant resistance ; wheat ; Sitobion fragariae ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Extended sieve element salivation (E1 waveform in the electrical penetration graph) is a characteristic activity during early sieve element punctures, particularly in resistant plants. In order to explore a chemically-mediated mechanism of resistance associated with sieve element salivation, we compared the pattern of feeding behaviour of the aphid, Sitobion fragariae (Walker), on two cultivars of the wheat Triticum aestivum L., with different concentrations of hydroxamic acids (Hx). During 24 h of electronic monitoring, aphids dedicated over 50% of the total time to phloem ingestion from the sieve elements. Total time allocated to E1 in the experiment, time to first E1 within the experiment, time allocated to E1 before a sustained phloem ingestion (E2) and the contribution of sieve element salivation to the phloem phase (E1/[E1+E2]) were significantly higher in the high-Hx cultivar. The increased salivation in plants with higher contents of Hx suggests the existence, at least in this system, of a chemically-mediated sieve element constraint.
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  • 7
    Electronic Resource
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    Springer
    Cellular and molecular life sciences 52 (1996), S. 942-949 
    ISSN: 1420-9071
    Keywords: Apoptosis ; transglutaminase ; signalling ; gene expression ; promoter elements ; retinoic acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Clarification of the molecular details of forms of natural cell death, including apoptosis, has become one of the most challenging issues of contemporary biomedical sciences. One of the effector elements of various cell death pathways is the covalent cross-linking of cellular proteins by transglutaminases. This review will discuss the accumulating data related to the induction and regulation of these enzymes, particularly of tissue type transglutaminase, in the molecular program of cell death. A wide range of signalling pathways can lead to the parallel induction of apoptosis and transglutaminase, providing a handle for better understanding the exact molecular interactions responsible for the mechanism of regulated cell death.
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  • 8
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    Springer
    Cellular and molecular life sciences 51 (1995), S. 1116-1123 
    ISSN: 1420-9071
    Keywords: Antisense RNA ; gene expression ; insertional mutagenesis ; physical mapping ; reporter genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Over the past ten years, powerful molecular genetic techniques have been developed to analyze gene function inDictyostelium. DNA-mediated transformation using a variety of selections and vectors has allowed the introduction of wild-type or modified genes that are under various forms of transcriptional control. Homologous recombination is efficient and can be used to modify the genome in precise ways. In addition, it is now possible to clone genes based on their mutant phenotype alone, either by insertional mutagenesis, or by screening antisense expression cDNA libraries. Finally, a nearly complete physical map of the genome is available and so genes are easily mapped by physical techniques. We discuss many of these advances within the context of major research problems presently under study.
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  • 9
    Electronic Resource
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    Springer
    Cellular and molecular life sciences 51 (1995), S. 606-611 
    ISSN: 1420-9071
    Keywords: Metallothionein ; isometallothioneins ; gene expression ; rabbit kidney cell-line ; cadmium adaptation ; zinc adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We explored the molecular genetics underlying the massive induction of isoMTs by Zn2+ or Cd2+ in metal tolerant rabbit kidney (RK-13) sub-line cells, using band shift assays and Southern blotting analysis. In sub-line cells accommodated to intermediate metal concentrations (100 μM Zn2+; 1–20 μM Cd2+) evidence suggested that the increase in the capacity for isoMT synthesis is brought about by an increased binding activity of the nuclear transcription factors MTF-1 and Sp1. Using quantitative band shift analysis with a mouse MRE-d oligonucleotide probe, the binding of both transcription factors was found to be enhanced two to three times over the binding activity measured in the unexposed parental RK-13 cells. Their increase in binding activity is probably the cause of the overexpression of MT genes and the development of metal tolerance in these cells. In cells tolerant to the highest concentrations of metal the analysis of Southern blot signals revealed MT gene amplification to be the most probable cause of the increased MT production. Thus, in cells of sub-lines growing in the presence of 350 μM Zn2+, two of the isoMT genes were coordinately triplicated and in cells tolerant to 150 μM Cd2+ one isoMT gene was amplified two-fold.
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  • 10
    Electronic Resource
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    Springer
    BioMetals 11 (1998), S. 345-358 
    ISSN: 1572-8773
    Keywords: calcium ; CREB ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Through the evolution of multicellular organisms, calcium has emerged as the preferred ion for intracel-lular signalling. It now occupies a pivotal role in many cell types and nowhere is it more important than in neurons, where it mediates both the relaying and long-term storage of information. The latter is a process that enables learning and memory to be formed and requires the activation of gene expression by calcium signals. Evidence from a number of diverse organisms shows that transcription mediated by the transcrip-tion factor CREB is critical for learning and memory. Here we review the features of CREB activation by calcium signals in mammalian cells. In contrast to other transcription factors, its regulation is dependent on an elevation of nuclear calcium concentration, potentially placing this spatially distinct pool of calcium as an important mediator of information storage.© Kluwer Academic Publishers
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  • 11
    Electronic Resource
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    Springer
    European journal of nutrition 22 (1983), S. 27-33 
    ISSN: 1436-6215
    Keywords: wheat ; lysine ; carnitine ; lipids ; mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung 32 abgesetzte männliche Albinoratten wurden in 4 Gruppen eingeteilt, um die Wirkung einer lysinarmen Weizendiät (AW), einer Weizendiät mit 0,4 % Lysin (LW) oder 0,2 % Carnitin (CW) sowie einer Caseindiät auf den Stoffwechsel von Lipiden in verschiedenen Geweben zu untersuchen. Nach 8 Wochen Fütterung der verschiedenen Diäten unter Anwendung der „paired feeding technique“ wurden Veränderungen in den Gesamtlipiden, den Lipidbestandteilen, den einzelnen Fettsäuren und dem Lipidgehalt der Mitochondrien des Herzens, der Skelettmuskeln, der Lungen und des Fettgewebes der Tiere bestimmt. Die lysinarme Weizendiät (AW) bewirkte eine Lipidanreicherung (vor allem an Acylglyzerinen) im Herzen, in der Leber, den Skelettmuskeln sowie eine Lipidabnahme im Fettgewebe. Die Diäten mit 0,4 % Lysin (LW) oder 0,2 % Carnitin (CW) zeitigten die entgegengesetzte Wirkung, wobei CW wirkungsvoller erschien als LW. LW und CW erhöhten die relativen Anteile von C14∶0-, C16∶0- und C16∶1-Fettsäuren und verkleinerten diejenigen von C18∶1-, C18∶2- und C18∶3-Fettsäuren, während die Anteile unter der AW- und Caseindiät ab- bzw. zunahmen. Die Fettsäurezusammensetzung des Fettgewebes war bei allen Gruppen gleich. Die AW-Diät vergrößerte die relativen Anteile von C14∶0- und C20∶4- und verringerte die von C16∶0-, C16∶1- und C18∶3-Fettsäuren in den Lungen. Die AW-Ergänzungsdiäten verringerten die relativen Anteile von C16∶0-, C16∶1-, C18∶3-sowie auch der C18∶1-Fettsäuren. Der Lipidgehalt der Mitochondrien von Leber, Herz, Skelettmuskeln und Lunge verringerte sich unter der AW-Diät und erhöhte sich unter den LW- und CW-Diäten.
    Notes: Summary 32 weanling male albino rats were divided into 4 groups to study the effects of lysine-deficient wheat diet (AW) and AW supplemented with either 0.4 % lysine (LW) or 0.2 % carnitine (CW) as compared to casein diet on metabolism of lipids in various tissues. LW, CW and casein diet groups were pair-fed with AW group. Changes in total lipids, lipid components, individual fatty acids, mitochondrial content in liver, heart, skeletal muscles, lungs and adipose tissue were determined after 8 weeks of feeding. AW diet resulted in accumulation of lipids (mainly acylglycerols) in heart, liver, skeletal muscles and depletion in adipose tissue. The LW and CW diets reversed the effects of AW diet, the CW being more effective than LW diet. The LW and CW diets increased the relative proportion of C 14∶0, C 16∶0, C 16∶1 and decreased that of C18∶1, C18∶2, C18∶3 fatty acids which were decreased and increased, respectively, on the AW and casein diets. The fatty acids composition of adipose tissue was the same in all the groups. The AW diet increased the relative proportions of C 14∶0, C 20∶4 and decreased that of C 16∶0, C 16∶1, C 18∶3 fatty acids in the lungs. Supplemented AW diet decreased the relative proportions of the former group and increased that of the later group including C 18∶1 fatty acid also. The mitochondrial content of liver, heart, skeletal muscles and lungs was decreased on AW and reversed on LW and CW diets.
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  • 12
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    Plant molecular biology reporter 16 (1998), S. 323-339 
    ISSN: 1572-9818
    Keywords: Aux/IAA genes ; gene expression ; gene families ; RT-PCR ; tomato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have developed an improved method for determination of gene expression levels with RT-PCR. The procedure is rapid and does not require extensive optimization or densitometric analysis. Since the detection of individual transcripts is PCR-based, small amounts of tissue samples are sufficient for the analysis of expression patterns in large gene families. Using this method, we were able to rapidly screen nine members of the Aux/IAA family of auxin- responsive genes and identify those genes which vary in message abundance in a tissue- and light-specific manner. While not offering the accuracy of conventional semi-quantitative or competitive RT-PCR, our method allows quick screening of large numbers of genes in a wide range of RNA samples with just a thermal cycler and standard gel analysis equipment.
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  • 13
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    Plant molecular biology reporter 17 (1999), S. 371-383 
    ISSN: 1572-9818
    Keywords: epidermal peel ; extraction ; gene expression ; stomata ; tree tobacco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Stomatal guard cells are critical for maintenance of plant homeostasis and represent an interesting cell type for studies of leaf cell differentiation and patterning. Here we describe techniques for the isolation of guard cell RNA and protein from blended epidermal peels of Nicotiana glauca. The RNA isolation procedure is a modification of the hot borate method, which is particularly well-suited for recalcitrant tissues. Protein was extracted by disrupting guard cell-enriched epidermis with a French® press. This system offers the following advantages: relatively high yield, low or no contamination by other cell types, fresh tissue as a source of RNA and protein rather than protoplasts, and a plant species that is readily transformable. These techniques will allow for cloning and analysis of genes expressed in guard cells, application of traditional biochemical techniques to guard cell proteins, as well as characterization of genetic manipulation of guard cell function in transgenic plants.
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  • 14
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    Plant molecular biology reporter 17 (1999), S. 323-331 
    ISSN: 1572-9818
    Keywords: Agrobacterium ; modular vector ; transformation ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Wheat (cv Chinese Spring) tissues were transformed using Agrobacterium tumefasciens and a new plasmid modular vector, pMVTBP. We constructed pMVTBP with unique restriction sites connecting (1) the CaMV 35S promoter, (2) a Kozak sequence, (3) the FLAG epitope, (4) the (His)6 epitope, (5) a coding region (for wheat TATA Binding Protein, wTBP) and (6) the CaMV 35S 3′UTR. This vector thus allows easy exchange of different regulatory or coding sequences. Explants of either germinating mature seeds, or immature embryos, were induced to callus for up to two weeks, treated with virulence-induced bacteria for one hour, then regenerated into plantlets. Transient expression of a GUS reporter gene, assayed at about one week, occurred in 10–12% of calluses. Expression of the FLAG-tagged wTBP was also detected, by immunostaining. Stable expression, by selective growth on geneticin, and by GUS expression at about six weeks, occurred in 1–2% of calluses, quite comparable to that achieved by other methods.
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  • 15
    ISSN: 1573-0832
    Keywords: deoxynivalenol ; enzyme immunoassay ; feed ; maize ; mycotoxins ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Samples of wheat (n = 25) and maize (n = 30) for animal consumption, collected in 1997 after harvest from western Romania, were analyzed by enzyme immunoassays for mycotoxin contamination. Toxins analyses included deoxynivalenol (DON), 3-acetylDON, 15- acetylDON, fusarenone X (FX), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), zearalenone (ZEA), fumonisin B1 (FB1), aflatoxin B1 (AFB1), ochratoxin A (OA), and citrinin (CT). DON and acetylDONs were the major contaminants in wheat (100%) and maize (46%). Median values for DON, 3-acetylDON, and 15-acetylDON were 880 μg kg-1, 66 μg kg- 1, and 150 μg kg-1 in wheat, and 890 μg kg-1, 180 μg kg-1, and 620 μg kg- 1 in maize, respectively. Additionally, 3,15-diacetylDON was detected in some samples by HPLC-EIA analysis. All samples were negative for FX (〈150 μg kg-1). T-2 was found in wheat (n = 6) and maize (n = 1) at levels between 13 and 63 μg kg- 1. DAS (2.6 μg kg-1) was found in one maize sample. ZEA occurred in all wheat and in four maize samples, median values were 10 μg kg-1 and 250 μg kg-1, respectively. One maize sample contained FB1 (140 μg kg-1). All samples were AFB1-negative (〈4 μg kg-1). OA was found in one wheat sample (37 μg kg- 1), CT was found in one maize sample (580 μg kg- 1). This first reported natural occurrence of a range of mycotoxins in Romanian feeding stuff shows that DON and acetyl DONs may be present at levels which may affect animal production.
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  • 16
    ISSN: 1573-0832
    Keywords: Fusarium ; mycotoxins ; occurrence ; trichothecenes ; wheat ; zearalenone ; deoxynivalenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Wheat for human consumption (140 samples) was collected after harvest from all regions of Bulgaria. The 1995 crop year was characterized by heavy rainfall in the spring and summer months. The internal mycoflora of wheat samples was dominated by Fusarium spp. and Alternaria spp., and storage fungi were rarely present. The samples were analysed for contamination with Fusarium mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), and zearalenone (ZEA), using enzyme immunoassay methods. DON and ZEA were the predominant toxins, with a contamination frequency of 67% and 69%, respectively. The average levels of these toxins in positive samples were 180 μg/kg (DON) and 17 μg/kg (ZEA), maximum concentrations were 1800 μg kg−1 and 120 μg kg−1, respectively. Acetyl derivatives of DON, namely 3-AcDON and 15-AcDON, were found in 2.1 % and 0.7% of the samples, at at maximum level of about 100 μg kg−1. Only one sample was positive for T-2 (55 μg/kg), DAS was not detected. This is the first report about the natural occurrence of a range of Fusarium mycotoxins in wheat for human consumption in Bulgaria.
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  • 17
    ISSN: 1573-0867
    Keywords: 15N ; non-nod beans ; quantification of N2 fixation ; reference crops ; simulation technique ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A technique for the application of the15N isotope dilution technique for the quantification of plant associated biological nitrogen fixation (BNF) was tested and applied to quantify the BNF contribution to two genotypes ofPhaseolus vulgaris. The technique makes use of sequential measurements of the15N enrichment of soil mineral N, and the uptake of labelled N by the “N2-fixing” plant, to simulate its uptake of soil N (the “soil to plant simulation” technique). The test was made with two non-N2-fixing crops (non-nodulating beans and wheat) and two bean genotypes (PR 923450 and Puebla 152), at two levels of N fertilizer addition (10 and 40 kg N ha−1), to compare the actual N uptake with that simulated from the soil and crop15N data. The simulation of the soil N uptake by the non-nod bean crop using this “soil to plant simulation” technique underestimated by 20 to 30% the true N uptake, suggesting that the mineral N extracted from soil samples taken from the 0–15cm layer had a higher15N enrichment than that N sampled by the roots of this crop. In the case of the wheat crop the simulation resulted in a much greater underestimation of actual N uptake. In general the results using this technique suggested that BNF inputs to the bean cultivars was higher than would be expected from the nodulation and acetylene reduction data, except for the early PR beans in the 40 kg N ha−1 treatment. In this case the total N and simulated soil N accumulation were well matched suggesting no BNF inputs. An allied technique (the “plant to plant simulation technique”) was proposed where the15N enrichrnent of soil mineral N was simulated from the data for total N and labelled N accumulation taken from sequential harvests of either of the non-N2 -fixing control crops. This was then utilized in combination with the labelled N uptake data of the other crop to simulate its soil N uptake. However, the results using either technique indicated that the wheat and non-nod or nodulating beans exploited pools of N in the soil with completely different15N enrichments probably due to differences in exploitation of the soil N with depth.
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  • 18
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    Nutrient cycling in agroecosystems 45 (1995), S. 209-215 
    ISSN: 1573-0867
    Keywords: climate ; fertilizer recovery ; 15N fertilizer ; precipitation-evaporation quotient ; soil ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Data was assembled from experiments on the fate of15N-labelled fertilizer applied to wheat (Triticum spp.) grown in different parts of the world. These data were then ranked according to the annual precipitation-evaporation quotient for each experimental location calculated from the average long-term values of precipitation and potential evaporation. Percentage recovery of15N fertilizer in crop and soil varied with location in accordance with the precipitation-evaporation quotient. In humid environments more15N fertilizer was recovered in the crop than in the soil, while in dry environments more15N fertilizer was recovered in the soil than in the crop. Irrespective of climatic differences between locations 20% (on average) of the15N fertilizer applied to wheat crops was unaccounted for at harvest. Most of the15N fertilizer remaining in the soil was found in the 0–30 cm layer. The most likely explanation of these differences is that wheat grown in dry environments has a greater root:shoot ratio than wheat grown in humid environments and, further, that the residue of dryland crops have higher C/N ratios. Both factors could contribute to the greater recovery of15N fertilizer in the soil in dry environments than in humid ones.
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  • 19
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    Nutrient cycling in agroecosystems 46 (1996), S. 225-234 
    ISSN: 1573-0867
    Keywords: long-term experiment ; maize ; wheat ; fertilizers ; farm yard manure ; weedicide application ; yield sustainability ; zinc deficiency ; nutrient uptake ; cropping sequence ; organic carbon build-up
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Long-term field experiments play an important role in understanding the complex interactions of plants, soils, climate and management and their effects on sustainable crop production. A long-term fertilizer experiment with maize-wheat-cowpea (fodder) is in progress since 1971 at Punjab Agricultural University farm Ludhiana, India. The experimental result for the first 21 years showed that application of N alone or in combination with P did not produce as much maize and wheat grains as the application of N, P and K together. Eight years after the start of the experiment, the optimal levels of N, P and K application (100% NPK) were unable to sustain the similar (maize) yield level as before because of Zn deficiency. Whereas in FYM amended plots the Zn deficiency did not appear and the higher crop yields could be sustained. The chemical control of weeds could not sustain the maize productivity at the same level as the manual removal of weeds. It was concluded that the high level of crop production can be sustained with the application of N, P and K under intensive cropping system provided deficiency of any of the micronutrient does not crop up. The deficiency of Zn is most likely to occur in semi-arid light textured alluvial soils under intensive cropping without the addition of farm yard manure/organic manures. In maize based cropping systems, manual control of weeds may be preferred to the chemical one. Addition of FYM in conjunction with 100% NPK is most beneficial both from bio-physical and economic point of view.
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  • 20
    ISSN: 1573-0867
    Keywords: millet ; sorghum ; rice ; maize ; wheat ; nutrient harvest index ; post-anthesis nutrient uptake ; recovery fraction ; simulation modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In land use plans, fertilizer recommendations are indispensable to avoid soil nutrient depletion or soil water pollution. Nutrient relations of five cereals have been evaluated on the basis of a literature review with the aim of arriving at such fertilizer recommendations at regional level. Nutrients considered were nitrogen, phosphorus and potassium for millet, sorghum, maize, rice and wheat. The relevant nutrient relations are fertilizer nutrient application to nutrient uptake, and nutrient uptake to crop yield. In addition, post-anthesis nutrient uptake is considered. Subsequently, obtained results are used in simulation modelling exercises to calculate the time required to attain an equilibrium nutrient balance and to investigate the effect of erosion control and straw recycling. Although fertilizer requirements could be assessed for each of the five cereals, monitoring of nutrient supply from natural sources remains necessary. Moreover, research on fertilizer use should focus on improvement of fertilizer recoveries and multiperiod models for both N and P uptakes by crops to allow quantitative land use planning where the time scale is included.
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    Nutrient cycling in agroecosystems 44 (1995), S. 217-223 
    ISSN: 1573-0867
    Keywords: foliar fertilizer ; nitrate ; potassium ; urea ; wheat ; yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Winter wheat crops were grown with ostensibly adequate supplies of all soil nutrients in 1990 and 1991 with the aim of testing if late foliar supplements of K and N, applied at key development stages, could improve grain yield and grain N content. Foliar sprays of KNO3 solution, supplying up to 40 kg K ha−1 in total, at flag leaf unfolded, inflorescence completed and the watery-ripe stage of grain filling, had no effect on yield, yield components or grain N. Urea, supplying 40 kg N ha−1 at flag leaf unfolded, had no effects on grain yield and grain N in 1990, but in 1991 grain N was increased by 0.14% whilst yield was reduced by up to 0.6 t ha−1. Urea scorched flag leaf tips in both years. In 1990, the spring was very dry and foliar supplements might have been expected to have had an effect, but on this highly fertile soil all crop K and N requirements were met from the soil.
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    Nutrient cycling in agroecosystems 53 (1999), S. 139-146 
    ISSN: 1573-0867
    Keywords: critical levels of Mn ; soil extractants ; Mn-deficiency ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seven chemical extractants were tested for their relative performance to predict the response of wheat to Mn application in coarse textured alkaline soils of semi-arid region. Five out of the seven extractants were found to be promising for the estimation of critical level of available Mn in these soils, as the amount of Mn extracted by these extractants was positively and significantly correlated with relative grain yield as well as Mn uptake. The critical deficiency level of soil available Mn with 0.005 M DTPA, 0.02% hydroquinone, 0.02 N sodium pyrophosphate, 0.1N H3PO4 and 0.05N HCl+0.025N H2SO4 was 3.1, 13.8, 23.5, 5.3 and 17.8 mg kg-1 soil, respectively. The 1N ammonium acetate and 0.01M CaCl2 were found to be unsuitable extractants for these soils. Further field trials at eight locations with varying levels of Mn deficiency showed successive increase in the grain yield of wheat with foliar Mn application, emphasizing the need for Mn fertilization when wheat is grown on Mn deficient soils.
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    Nutrient cycling in agroecosystems 3 (1982), S. 63-71 
    ISSN: 1573-0867
    Keywords: nitrogen efficiency ; nitrogen fate ; rational use ; rice ; supergranules of urea ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Using15 N tracer technique, the fate and efficiency of nitrogen in supergranules of urea as compared with that in powdered urea were studied in rice fields. The results obtained show that supergranules of urea were characterized by the slight N loss and high N recovery as well as by delayed but long lasting fertilization effects. It follows that the supergranules should be applied earlier and at a lower rate as compared with powdered urea.
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    Nutrient cycling in agroecosystems 5 (1984), S. 95-108 
    ISSN: 1573-0867
    Keywords: Nitrogen fertilizer ; sorghum ; wheat ; soil test
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A static model that predicts the nitrogen (N) fertilizer requirement of grain sorghum or wheat crops is described. Inputs required by the model are soil nitrate-N (kg ha−1) in the profile at sowing, total N (%) in the plough layer, available water in the profile at sowing (mm) plus rainfall during the growing season (mm). Output includes fertilizer N required for both maximum yield and optimum economic yield. The model was tested by using published field data from Nebraska and Kansas (U.S.A.), South Australia and Northern Territory (Australia), and Saskatchewan (Canada). The model was accurate when no fertilizer N was required, and when large amounts were required, but quantitative prediction of moderate requirements was only fair. Predictions for grain sorghum were better than for winter wheat, probably because total water use was a better predictor of yield potential for grain sorghum than for winter wheat. Further refinement for specific environments should make the model practical for dryland cereal crops.
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    Mycopathologia 68 (1979), S. 131-137 
    ISSN: 1573-0832
    Keywords: Erysiphe graminis f. sp.tritici ; powdery mildew fungus ; resistance ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract During primary infection by conidia ofErysiphe graminis f. sp.tritici, three mechanisms of resistance operate in first leaves of 8-day-old seedlings of both resistant and susceptible wheats. The first mechanism, operating at the penetration site, is responsible for the failure of penetrations attempted by primary germ tubes (PGT). The second mechanism is concerned with the abortion of haustoria in normal-appearing host cells. The third mechanism relates to the abortion of haustoria and the hypersensitivity of the penetrated host cells. With the inoculum-level of 19–24 conidia/mm2, the three mechanisms together prevented 89.3 % of the attempted penetrations by PGT from producing normal haustoria in resistant wheat Purdue 5752C1-7-5-1 and 37.4 % in the susceptible wheat Vermillion. The first mechanism accounted for the prevention of 73.3 % of the attempted PGT penetrations on Purdue 5752C1-7-5-1 and 36 % on Vermillion. The second mechanism was responsible for stopping 19 % of all the successful penetrations in Purdue 5752C1-7-5-1 and 0.8 % in Vermillion. The third mechanism accounted for the failure of 41 % of all the successful penetrations in Purdue 5752C1-7-5-1 and 1.4% in Vermillion. Thirty-six hours after inoculation, 10.7% of all the attempted PGT penetrations appeared to be developing normally in first leaves of 8-day-old seedlings of resistant wheat Purdue 5752C1-7-5-1 as compared to 62.6 % in the susceptible wheat Vermillion. This appears to be the first report showing the relative effectiveness of various mechanisms of resistance concerning any powdery mildew fungus.
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    Nutrient cycling in agroecosystems 5 (1984), S. 235-243 
    ISSN: 1573-0867
    Keywords: iron pyrites ; wheat ; chickpea ; mustard ; Egyptian clover ; biomass production ; S uptake ; P mobilization ; P uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A field experiment was conducted for three consecutive winter crop seasons commencing in 1979–80 on the Typic Ustochrept of Pura to evaluate iron pyrites as S fertilizer. Four crops viz, wheat, chickpea, mustard and Egyptian clover were tested for their responsiveness to added pyrites. All the crops responded significantly to added pyrites. Mustard proved most sensitive to S deficiency in soil and wheat the least. Between the two legumes, Egyptian clover was more sensitive to S stress than chickpea. Average biomass production by Egyptian clover was highest followed by wheat, mustard and chickpea. Mustard and Egyptian clover required more S to achieve maximum biomass production compared with wheat and chickpea but they also recovered from the soil a large proportion of added S than wheat and chickpea. Addition of pyrites increased availability of S in soil. Pyrites enhanced mobilization of soil P and its utilization by the crops.
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  • 27
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    Nutrient cycling in agroecosystems 45 (1995), S. 163-167 
    ISSN: 1573-0867
    Keywords: Basal dressing ; Se-enriched fertilizers ; Se-uptake ; soil texture ; top-dressing ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A multisite field experiment was conducted to study the effect of topdressed Se-enriched Ca(NO3)2 (CN) and basal applied NPK on the selenium (Se) concentration in spring wheat (Triticum aestivum L.). Selenium was applied either through CN (at the rates of 0, 6.45, and 12.91 g Se ha−1) or NPK (5.83 g Se ha−1). Selenium concentration in wheat grains increased consistently with increasing rate of Se-enriched CN or NPK. However, the superiority of Se-enriched CN over NPK in raising the Se concentration in wheat grain depended on location and growth conditions. At the same rate both methods of Se-application were found to be equally effective in raising the Se concentration of wheat grains. The Se concentration of grain was generally higher in the light textured soils than in the medium to heavy textured soils. Without Se application, the Se-concentration in wheat grain was about 16µg kg−1 which is regarded insufficient to meet the Se requirement for Se in animal and human. Calcium nitrate enriched with 25 mg Se kg−1 (6.45 g Se ha−1) increased the Se concentration in wheat grain to a desired level.
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  • 28
    ISSN: 1572-9699
    Keywords: bioluminescence ; Pseudomonas ; root colonization ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The bioluminescently marked Pseudomonas fluorescens strain 5RL, has been used previously to follow colonisation of soy bean roots (De Weger et al. [1991] Appl. Environ. Microbiol. 57:36-41). In the present paper the method has been further developed and optimized for wheat roots and it is used to get a quick overview of the colonisation patterns of many different root systems at the same time. Colonisation was followed on wheat plants grown in our gnotobiotic sand system (Simons et al., 1996. Mol Plant Microbe Interact 9: 600–607) and the following results were obtained. (i) A spatio-temporal analysis of the colonisation of wheat roots showed that 4 days after planting the highest bacterial activity was observed at the upper part of the root. After 6 days the high bacterial activity at the upper part was further increased, whereas spot-like activities were observed on the lower root parts, possibly due to micro-colonies. (ii) Bacterial mutations causing lack of motility or auxotrophy for amino acids resulted in impaired colonisation of the lower root parts, indicating that motility and prototrophy for the involved amino acid(s) are important factors for wheat root colonisation by strain 5RL. (iii) Coinoculation of strain 5RL with other wild type Pseudomonas strains on the root influenced the colonisation pattern observed for strain 5RL. Colonisation was not visually affected when the competing strain was a poor root coloniser, but was severely reduced when the competing strain was a good root coloniser. The results show that the spatio-temporal colonisation of wheat root by P. fluorescens strain 5RL and derivatives is similar to that of strain WCS365 on tomato. The advantage of the use of lux-marked strains is that the results are obtained much quicker than when conventional methods are used and that the result is supplied as an image of the colonisation pattern of many different roots.
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  • 29
    ISSN: 1572-9761
    Keywords: Coccinellidae ; Aphididae ; wheat ; spatial scale ; species diversity ; numerical response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The influence of prey density, within-field vegetation, and the composition and patchiness of the surrounding landscape on the abundance of insect predators of cereal aphids was studied in wheat fields in eastern South Dakota, USA. Cereal aphids, aphid predators, and within-field vegetation were sampled in 104 fields over a three year period (1988–1990). The composition and patchiness of the landscape surrounding each field were determined from high altitude aerial photographs. Five landscape variables, aggregated at three spatial scales ranging from 2.6 km2 to 581 km2, were measured from aerial photographs. Regression models incorporating within-field and landscape variables accounted for 27–49% of the variance in aphid predator abundance in wheat fields. Aphid predator species richness and species diversity were also related to within-field and landscape variables. Some predators were strongly influenced by variability in the composition and patchiness of the landscape surrounding a field at a particular spatial scale while others responded to variability at all scales. Overall, predator abundance, species richness, and species diversity increased with increasing vegetational diversity in wheat fields and with increasing amounts of non-cultivated lands and increasing patchiness in the surrounding landscape.
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    Integrated pest management reviews 4 (1999), S. 127-143 
    ISSN: 1572-9745
    Keywords: wheat ; stored-grain ; integrated pest management ; aeration ; biological control ; grain sampling ; insect monitoring ; modeling ; area-wide IPM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Management of stored-grain insect pests by farmers or elevator managers should be based upon a knowledge of the grain storage environment and the ecology of insect pests. Grain storage facilities and practices, geographical location, government policies, and marketing demands for grain quality are discussed as factors influencing stored-grain insect pest management decisions in the United States. Typical practices include a small number of grain samples designed to provide grain quality information for segregation, blending and marketing. This low sampling rate results in subjective evaluation and inconsistent penalties for insect-related quality factors. Information on the efficacy of insect pest management practices in the United States, mainly for farm-stored wheat, is discussed, and stored-grain integrated pest management (IPM) is compared to field-crop IPM. The transition from traditional stored-grain insect pest control to IPM will require greater emphasis on sampling to estimate insect densities, the development of sound economic thresholds and decision-making strategies, more selective use of pesticides, and greater use of nonchemical methods such as aeration. New developments in insect monitoring, predictive computer models, grain cooling by aeration, biological control, and fumigation are reviewed, their potential for improving insect pest management is discussed, and future research needs are examined.
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    Cellular and molecular life sciences 52 (1996), S. 888-891 
    ISSN: 1420-9071
    Keywords: Ageing ; rat ; brain ; gene expression ; differential display
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have used the polymerase chain reaction (PCR)-based technique of differential display to analyse changes in gene expression during ageing of the rat brain. In this approach we have compared three young adult (6 months) with three old adult (20 months) animals. RNA preparations from the homogenised brains were subjected to reverse transcriptase (RT)-PCR using 36 different combinations of primer pairs. Any PCR product which was consistently found to be more prominent in the three young brains compared to the three old brains, and vice versa, was scored as potentially representing a gene which was differentially expressed during the ageing of this tissue. Out of a possible 2000+PCR products we identified 44 that might represent genes that exhibit differential expression during ageing of the rat brain. An initial screen of these fragments, by Southern-blotting the PCR products and hybridising them with cDNA probes derived from either young or old brain RNA preparations, indicated that 40% of them represented genes that were differentially expressed. This approach is likely to prove invaluable for identifying cohorts of genes that show differential expression during the ageing process.
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  • 32
    ISSN: 1432-203X
    Keywords: glyphosate ; gene expression ; gene amplification ; cell culture ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The stability and expression of amplified 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) genes was examined in glyphosate resistant tobacco cells grown in glyphosate-free medium, and in plantlets regenerated from resistant cells. Amplified DNA was maintained in resistant cells grown in the absence of glyphosate for three years. Amplified EPSPS genes were retained in regenerated plantlets at levels comparable to those observed in the resistant cells, and EPSPS mRNA was overexpressed (compared to unselected plantlets). However, glyphosate resistance in cell lines grown in glyphosate-free medium declined 7-fold, and in regenerated plantlets approximately 20-fold, compared to resistant cells maintained under glyphosate selection. In plantlets, reduced resistance correlated with lower levels of EPSPS mRNA. Plantlets regenerated from resistant cells exhibited morphological variation, and had an approximate doubling of their nuclear genome size.
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  • 33
    ISSN: 1573-4919
    Keywords: vasoactive intestinal peptide ; ulcerative colitis ; gene expression
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The availability of colon provides a ready source of human neurons. Among the products of nerve cell bodies, vasoactive intestinal peptide is a neuropeptide that serves as a marker of non-adrenergic, non-cholinergic inhibitory nerves in colon. These nerves have been proposed to be involved in regulation of immune function, secretion, and smooth muscle function. In previous work, we identified decreased tissue levels of vasoactive intestinal peptide in a disorder of chronic colonic mucosal inflammation, ulcerative colitis. We hypothesized that diminished gene expression of vasoactive intestinal peptide could result in decreased tissue levels of this neuropeptide. Sigmoid colon was obtained at surgery from controls (n=6) and patients with ulcerative colitis (n=6). Vasoactive intestinal peptide mRNA was quantified by Northern blot hybridization and tissue levels of vasoactive intestinal peptide were determined by radioimmunoassay. Tissue vasoactive intestinal peptide was decreased only in the mucosalsubmucosal layer of ulcerative colitis (p=.02). There was a single 1.7 kbase vasoactive intestinal peptide transcript identified in both control colon and ulcerative colitis. Normalized vasoactive intestinal peptide mRNA levels were increased by 260% in ulcerative colitis compared to controls (p〈.01). These observations suggest that decreased vasoactive intestinal peptide gene expression or abnormal post-transcriptional processing are not primary defects in this disorder of chronic inflammation. The findings support the alternative hypothesis that axonal degeneration in ulcerative colitis could result in increased expression of neuronal vasoactive intestinal peptide mRNA.
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  • 34
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; insulin ; calcium ; gene expression ; rat liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of refeeding on the expression of Ca2+-binding protein regucalcin mRNA in the liver of fasted rats was investigated. When rats were fasted overnight, the hepatic regucalcin mRNA level was reduced about 70% of that in feeding rats. Refeeding produced a remarkable elevation of hepatic regucalcin mRNA level (about 150–170% of fasted rats). Liver regucalcin concentration was appreciably increased by refeeding, although it was not altered by fasting. The oral administration of glucose (2 g/kg body weight) to fasted rats caused a significant increase in hepatic regucalcin mRNA level. Moreover, hepatic regucalcin mRNA level was clearly elevated by a single subcutaneous administration of insulin (10 and 100 U/kg) to fasted rats. The hormonal effect was not further enhanced by the simultaneous administration of calcium chloride (250 mg Ca/kg) to fasted rats, although calcium administration stimulated regucalcin mRNA expression in the liver. The present study suggests that the expression of hepatic regucalcin mRNA stimulated by refeeding is significantly involved in the action of insulin and/or calcium as stimulating factors.
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    Molecular and cellular biochemistry 143 (1995), S. 67-71 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; gene distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The existence and expression of gene encoding the Ca2+-binding protein regucalcin in various species and tissues were investigated with Southern and Northern hybridization analyses using regucalcin cDNA (0.9 kb of open reading frame). Genomic Southern hybridization analysis demonstrated that regucalcin gene was widely conserved among higher animals including human, monkey, rat, mouse, dog, bovine, rabbit and chicken. The gene was not found in yeast. The Northern blot analysis of poly (A)+RNAs extracted from the liver of various species showed that regucalcin mRNA was predominantly expressed in rat and mouse, although the expression was also seen in human, bovine and chicken. Furthermore, the enzyme-linked immunoadsorbent assay (ELISA) with rabbit-anti-regucalcin IgG indicated that hepatic regucalcin concentration was most pronounced in rat as compared with that of guinea pig, mouse and chicken. These observations show that the gene expression of regucalcin and its protein synthesis is unique in the liver of rats, suggesting the existence of a specific mechanism in demonstrating regucalcin synthesis from gene.
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    Molecular and cellular biochemistry 143 (1995), S. 137-141 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; estrogen ; gene expression ; rat liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of nuclear receptor-related hormones on the expression of hepatic calcium-binding protein regucalcin mRNA in rats was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin cDNA (0.9 kb of open-reading frame). A single subcutaneons administration of 17β-estradiol (0.5, 1.0 and 2.0 mg/kg body weight) in rats induced a remarkable increase of regucalcin mRNA in liver; the level was about 200% of control at 24 h after the administration of 2.0 mg/kg. The increase showed about 350% even at 6 h after the administration. Meanwhile, hepatic regucalcin mRNA level was not appreciably altered by a single subcutaneous administration of thyroxine (T4) (20, 40 and 80 mg/kg) or hydrocortisone (10 and 30 mg/kg) in rats. The present study demonstrates that the expression of hepatic regucalcin mRNA is stimulated by estrogen action in the liver nuclei of rats.
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    Molecular and cellular biochemistry 144 (1995), S. 105-108 
    ISSN: 1573-4919
    Keywords: fatty acid synthase ; gene expression ; and thyroid hormone
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of triiodothyronine (T3) on regulation of fatty acid synthase in chicken liver was investigated. In hypothyroid animals, enzyme activity was about one half of that in euthyroid animals. T3 treatment increased the enzyme activity in hypothyroid animals. There is little difference in both the mRNA concentration and the transcription rate between euthyroid and hypothyroid animals. T3 treatment markedly decreased both the mRNA concentration and the transcription rate in euthyroid and hypothyroid animals. These results suggested that T3 maintained the normal level of enzyme expression primarily by stimulating the post-transcriptional step, while the transcription of the gene was inhibited by hyperthyroidism.
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    Molecular and cellular biochemistry 155 (1996), S. 85-90 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; rat hepatoma ; Morris hepatoma cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Whether the gene expression of hepatic Ca2+-binding protein regucalcin is altered in hepatomas was investigated. The change in regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin complementary DNA (0.9 kb). Rat hepatoma was induced by continuous feeding of basal diet containing 0.06% 3′-methyl-4-dimethylaminoazobenzene (3′-Me-DAB). After 35 weeks feeding, rats were sacrificed, and the non-tumorous and tumorous tissues of the livers were removed. In individual rats, the regucalcin mRNA levels in the tumorous tissues were generally decreased in comparison with that of the non-tumorous tissues of the chemical-fed rats, although the chemical administration might decrease the mRNA expression in normal rat liver, suggesting that the chemical administration causes a suppresive effect on the mRNA expression. When the genomic DNA extracted from the liver tumorous tissues was digested with restriction enzymes (EcoRI, BamHI and HindIII) and analyzed by Southern blotting, no rear-ranged band was found in the regucalcin gene from the hepatoma. Interestingly, in the transplantable Morris hepatoma cells, the regucalcin mRNA was markedly expressed, while the albumin mRNA was expressed only slightly. The present study demonstrates that regucalcin mRNA is clearly expressed in the transformed cells (Morris hepatoma cells).
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    Molecular and cellular biochemistry 155 (1996), S. 105-111 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; aldosterone ; estrogen ; dexamethasone ; gene expression ; rat kidney cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of various steroid hormones on the expression of calcium-binding protein regucalcin mRNA in the kidney cortex of rats was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using rat liver regucalcin complementary DNA (0.9 kb of open-reading frame). Regucalcin mRNA was expressed in the kidney cortex but not the medulla. Rats received a single subcutaneous administration of steroid; the animals were sacrificed 60 min after the treatment of aldosterone (2.5, 5.0 and 10 μg/100 g body weight) or 6 h after the treatment of estrogen (17β-estradiol; 0.05, 0.1 and 0.2 mg/100 g), hydrocortisone (0.5, 1.0 and 3.0 mg/100 g) and dexamethasone (50, 100 and 150 μg/100 g). Regucalcin mRNA levels in the kidney cortex were clearly diminished by the administration of aldosterone or estrogen, while hydrocortisone administration had no effect. The administration of dexamethasone (100 μg/100 g) caused a remarkable increase of regucalcin mRNA levels in the kidney cortex. The dexamethasone-induced increase in regucalcin mRNA levels was completely blocked by the simultaneous administration of cycloheximide (150 μg/100 g), although the drug administration had no effect on the mRNA levels in control rats. Meanwhile, the dexamethasone administration did not cause an appreciable alteration of calcium content in the kidney cortex. The present study demonstrates that, of the various steroid hormones used, dexamethasone uniquely has a stimulatory effect on regucalcin mRNA expression in the kidney cortex of rats. The steroid effect may be mediated through a newly synthesized protein.
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    Molecular and cellular biochemistry 160-161 (1996), S. 307-313 
    ISSN: 1573-4919
    Keywords: myocardium ; hypertension ; gene expression ; estrogens ; cardiac hypertrophy ; signal transduction ; genetic program
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Gender specific differences in cardiovascular disease are largely mediated by sex hormones. The use of estrogens significantly reduces the overall incidence of heart disease in postmenopausal women. Beneficial effects of estrogens on plasma lipoprotein levels are clearly established. However, these do not explain the magnitude of risk reduction seen in clinical studies. Thus, additional and currently unknown functions of estrogens must be operative. Elucidation of the exact estrogen action in the heart will have important implications in the treatment of cardiovascular disease. It will probably enhance the therapeutic repertoire in treating heart disease, the most common cause of death in industrialized countries. We will review the current understanding of the function of estrogens in the heart and discuss potential strategies on how to apply these data to clinical practice.
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    Molecular and cellular biochemistry 162 (1996), S. 139-144 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; saline ingestion ; hypertensive rats ; kidney cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The effect of adrenalectomy (ADX) or saline ingestion, which is a hypertensive factor, on the expression of calcium-binding protein regucalcin mRNA in the kidney cortex of rats was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using rat liver regucalcin complementary DNA (0.9 kb of open-reading frame). Regucalcin mRNA was expressed in the kidney cortex but not the medulla. Rats were adrenalectomized, and 48 h later they were sacrificed. ADX caused a reduction of regucalcin mRNA levels in the kidney cortex, suggesting that adrenal glands participate in the regulation of the mRNA expression. This reduction was not restored by the subcutaneous administration of dexamethasone with an effective dose (1 mg/kg body weight), which can stimulate kidney regucalcin mRNA expression. Regucalcin mRNA levels in the kidney cortex of rats were markedly suppressed by the ingestion of saline for 7 days. The ADX-induced decrease of renal cortex regucalcin mRNA levels was not appreciably restored by saline ingestion. Moreover, regucalcin mRNA levels in the kidney cortex of spontaneous hypertensive rats (SHR) were clearly decreased as compared with that of control (Wistar-Kyoto) rats. Meanwhile, calcium content in the kidney cortex was not significantly decreased by ADX or saline ingestion. The present study suggests that the expression of regucalcin mRNA in the kidney cortex of rats is suppressed by saline administration.
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  • 42
    ISSN: 1573-4919
    Keywords: calreticulin ; gene expression ; steroid receptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Calreticulin is a ubiquitously expressed Ca2+ binding protein of the endoplasmic reticulum which inhibits DNA binding and transcriptional activation by steroid hormone receptors. In this study the effects of calreticulin on tyrosine aminotransferase (TAT) gene expression in cultured McA–RH7777 hepatocytes was investigated. McA–RH7777 cells were stably transfected with calreticulin expression vector to generate cells overexpressing the protein. The transcriptional activity of the TAT gene, which is glucocorticoid–sensitive and cAMP–dependent, was investigated in the mock transfected McA–RH7777 and in cells overexpressing calreticulin (designated McA–11 and McA–17). In the presence of dexamethasone or the cAMP analog (CTP–cAMP) expression of the TAT gene was induced in mock transfected McA–RH7777 cells by approximately 4.5 and 5 fold, respectively. In McA–11 and McA–17 cells, overexpressing calreticulin, glucocorticoi ever, the CTP–cAMP–dependent expression of the TAT gene was not affected. The ability of calreticulin to inhibit glucocorticoid–sensitive TAT gene expression but not the cAMP–dependent expression of the gene suggests that the protein affects specifically the action of transcription pathways involving steroid receptors or transcription factors containing KxFF(K/R)R–like motifs. Calreticulin may play an important role in the regulation of glucocorticoid–sensitive pathway of expression of the hepatocytes specific genes during development.
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  • 43
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    Molecular and cellular biochemistry 148 (1995), S. 45-57 
    ISSN: 1573-4919
    Keywords: manganese ; superoxide dismutase ; gene expression ; hyperoxide lung injury ; nuclear factor kappa B
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract TNFα and IL-1 each can activate NF-κB and induce gene expression of manganese superoxide dismutase (MnSOD), a mitochondrial matrix enzyme which can provide critical protection against hyperoxic lung injury. The regulation of MnSOD gene expression is not well understood. Since redox status can modulate NF-κB and potential κB site(s) exist in the MnSOD promoter, the effect of thiols (including NAC, DTT and 2-ME) on TNFα and IL-1 induced activation of NF-κB and MnSOD gene expression was investigated. Activation of NF-kB and increased MnSOD expression were potentiated by thiol reducing agents. In contrast, thiol oxidizing or alkylating agents inhibited both NF-κB activation and elevated MnSOD expression in response to TNFα or IL-1. Since protease inhibitors TPCK and TLCK can inhibit NF-κB activation, we also investigated the effect of these compounds on MnSOD expression and NF-κB activation. TPCK and TLCK each inhibited MnSOD gene expression and NF-κB activation. Since the MnSOD promoter also contains anAP-1 binding site, the effect of thiols and thiol modifying agents on AP-1 activation was investigated. Thiols had no consistent effect onAP-1 activation. Likewise, some of the thiol modifying compounds inhibited AP-1 activation by TNFα or IL-1, whereas others did not. Since diverse agents had similar effects on activation of NF-κB and MnSOD gene expression, we have demonstrated that activation of NF-κB and MnSOD gene expression are closely associated and that reduced sulfhydryl groups are required for cytokine mediation of both processes.
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  • 44
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    Keywords: regucalcin ; calcium-binding protein ; gene expression ; calmodulin ; spontaneous hypertensive rats ; rat kidney cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The expression of calcium-binding protein regucalcin mRNA in the kidney cortex of rats ingested with saline was investigated. The alteration in regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin complementary DNA (0.9 kb of open reading frame). Rats were freely given saline as drinking water for 7 days. Regucalcin mRNA levels in the kidney cortex were suppressed by saline ingestion. When calcium chloride (10 mg Ca/100 g body weight) was intraperitoneally administered to rats ingested with saline for 7 days, the effect of calcium administration to increase regucalcin mRNA levels was weakened by saline ingestion. Such effect was also seen by the administration of 2.5 and 5 mg Ca/100 g. Regucalcin mRNA levels in the kidney cortex of spontaneous hypertensive rats (SHR) were not appreciably increased by the administration of calcium (10 mg/100 g). Meanwhile, calcium content in the kidney cortex was significantly elevated by the administration of calcium (10 mg/100 g) to normal rats. This increase was weakened in saline-ingested rats. Moreover, Ca2+/calmodulin-dependent protein kinase activity in the cytosol of kidney cortex was significantly decreased by saline ingestion. These results suggest the possibility that saline ingestion-induced suppression of regucalcin mRNA expression in the kidney cortex is partly involved in the attenuation of Ca2+ signalling.
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  • 45
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    Keywords: microbodies ; diabetes mellitus ; steroid hormone receptor ; β-oxidation ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract To determine whether the increased fatty acid β-oxidation in the peroxisomes of diabetic rat liver is mediated by a common peroxisome proliferation mechanism, we measured the activation of long-chain (LC) and very long chain (VLC) fatty acids catalyzed by palmitoyl CoA ligase (PAL) and lignoceryl CoA ligase and oxidation of LC (palmitic acid) and VLC (lignoceric acid) fatty acids by isotopic methods. Immunoblot analysis of acyl-CoA oxidase (ACO), and Northern blot analysis of peroxisome proliferator-activated receptor (PPAR-α), ACO, and PAL were also performed. The PAL activity increased in peroxisomes and mitochondria from the liver of diabetic rats by 2.6-fold and 2.1-fold, respectively. The lignoceroyl-CoA ligase activity increased by 2.6-fold in diabetic peroxisomes. Palmitic acid oxidation increased in the diabetic peroxisomes and mitochondria by 2.5-fold and 2.7-fold, respectively, while lignoceric acid oxidation increased by 2.0-fold in the peroxisomes. Immunoreactive ACO protein increased by 2-fold in the diabetic group. The mRNA levels for PPAR-α, ACO and PAL increased 2.9-, 2.8- and 1.6-fold, respectively, in the diabetic group. These results suggest that the increased supply of fatty acids to liver in diabetic state stimulates the expression of PPAR-α and its target genes responsible for the metabolism of fatty acids.
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  • 46
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    Biochemical genetics 13 (1975), S. 663-671 
    ISSN: 1573-4927
    Keywords: lactate dehydrogenase ; isoenzymes ; differentiation ; blastocyst ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Unfertilized eggs and early embryos up to the 2-day (16-cell) cleavage stage of development in the rabbit contain predominantly the most cathodal lactate dehydrogenase isoenzyme made up of A-type subunits. Following early cleavage there is a progressive increase in total LDH activity in the embryo as development proceeds through 4- and 6-day blastocyst stages. This is accompanied by an increase in the amounts of B-type subunits and a concomitant shift in the lactate dehydrogenase isoenzyme electrophoretic pattern toward the anodal isoenzyme types.
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  • 47
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    Biochemical genetics 15 (1977), S. 47-57 
    ISSN: 1573-4927
    Keywords: wheat ; chromosomes ; gibberellin ; enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The three enzymes, α-amylase, peroxidase, and acid phosphatase, are among those released by the aleurone of bread wheat, Triticum aestivum, as a direct response to gibberellins (GA) from the embryo during germination. Aneuploid genotypes are used to investigate the chromosomal location, nature, and extent of genetic control of the release of these enzymes in endosperms after induction by exogenous GA. Ditelosomics demonstrate the effect of removal of known chromosome arms, and tetrasomics show the effect of duplication of chromosome pairs. Quantitative analysis demonstrates complex control systems over and above those previously found using zymogram techniques. For α-amylase, chromosome arms with net promoter effects and chromosomes with net inhibitor effects were found. These effects were not chromosome-dosage responsive, unlike the promoter-inhibitor system found for acid phosphatase control. Peroxidase levels in the endosperms were generally high in both types of aneuploids. With one exception, all chromosomes showing involvement as ditelosomics showed a similar effect as tetrasomics, indicating that in the euploid a balanced state restricting, rather than promoting, peroxidase levels existed.
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  • 48
    ISSN: 1573-4927
    Keywords: esterase ; duplication ; gene expression ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract An esterase duplication is described in the sibling species pair Drosophila mojavensis and Drosophila arizonensis. We present evidence for two separate structural loci mapping at a distance of less than 0.16 recombination units from each other. Alleles at the two loci have the same substrate specificities and form small amounts of interlocus heterodimers. One locus (Est-5) is functioning throughout the insect's life cycle and appears at high concentrations in the hemolymph and the fat body. Its duplicate (Est-4) functions only during the late larval stage and is concentrated mainly in the carcass. No null alleles at either locus were observed in population surveys. An examination of 12 other species from the repleta group, to which D. mojavensis and D. arizonesis belong, suggests that Est-5 is universally present, but the activity levels of Est-4 vary among species and may be totally absent in some species. Variation in the level of Est-4 activity does not closely follow the phylogenetic relationship.
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  • 49
    ISSN: 1573-4927
    Keywords: evolution ; polyploidy ; ribosomal RNA ; protein synthesis ; gene expression
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Hidden breaks occur in the ribosomal RNA of tetraploid Cyprinid fish such that the large ribosomal RNA (28 S) yields upon denaturation two RNA fragments of 8.7×105 and 5.0×105 daltons, whereas the small rRNA (18 S) yields fragments of 3.2×105 to 5.0×104 daltons. In tetraploid Cyprinids hidden breaks occur only in the rRNA of somatic tissue and not in oocytes and sperm cells. Hidden breaks can be detected only slightly in diploid Cyprinid species. Ribosomes purified from somatic tissue of tetraploid Cyprinids show a reduced efficiency in protein synthesis in vitro. The ribosomal proteins from diploid and tetraploid Cyprinid fish show considerable electrophoretic differences. This is discussed in light of a possible functional role of hidden breaks in rRNA in the process of diploidization of gene expression in tetraploid Cyprinid species.
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  • 50
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    Molecular and cellular biochemistry 155 (1996), S. 153-162 
    ISSN: 1573-4919
    Keywords: apolipoprotein B and E ; lipid ; gene expression ; rat ; mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The aim of the present investigation was to study the regulation of apolipoprotein E by two dietary nutrients, saturated fat and cholesterol, known to raise plasma cholesterol levels. ApoE is a protein component of several classes of lipoproteins including VLDL and HDL, and dietary lipids may regulate VLDL and apoE-containing HDL particles through their effects on apoE gene. Male rats and mice were fed the following 4 diets: control diet (C); high cholesterol diet with 0.5% cholesterol (HC); high fat diet with 20% hydrogenated coconut oil (HF); and high fat plus high cholesterol diet with 0.5% cholesterol and 20% fat (HF/C). Plasma cholesterol levels remained unchanged on HC diet, but in mice VLDL-cholesterol increased by 31%. HF diet increased VLDL and LDL by 15–17% in rats, and 21% in mice. A combination of fat and cholesterol diet showed pronounced effects on plasma lipoprotein concentrations, raising apoB-containing particles by 21% and 44% in mice and rats, respectively. Plasma apoE levels increased significantly on all diets. The mechanism of regulation of increased plasma apoB and apoE levels was examined. Quantification of hepatic apoB mRNA showed a lack of correlation between plasma apoB and hepatic apoB mRNA levels, suggesting that posttranscriptional regulation increased plasma apoB-containing lipoproteins in animals fed saturated fat diets. Hepatic apoE mRNA levels increased significantly in animals fed cholesterol-rich diets. However, despite increased plasma apoE levels on diet containing only saturated fat, hepatic apoE mRNA did not change. Synthesis of apoE on the liver polysomes increased selectively on cholesterol-rich diets. These results suggest that cholesterol-rich diets altered apoE, in part, by transcriptional mechanism, and saturated fat-rich diets increased plasma apoE levels by posttranscriptional mechanism, possibly decreased receptor-mediated uptake of apoE-containing particles. The regulation of LDL receptor was also studied since plasma apoB and E levels may be altered by LDL receptor-mediated uptake by the hepatocytes. As expected, high cholesterol diet decreased LDL receptor mRNA by 30–40%. However, the LDL receptor protein on liver membranes did not change on any of the test diets in both animal species. Hepatic cholesterol content increased several fold selectively on high cholesterol diets. These findings suggest that: 1) both transcriptional and posttranscriptional mechanisms are important in regulating plasma apoB and E containing lipoproteins; 2) dietary cholesterol regulates apoE gene by a transcriptional mechanism anddietary saturated fat by posttranscriptional mechanism; and 3) changes in the hepatic apoE and LDL receptor mRNA are associated with the changes in intracellular cholesterol concentrations.
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  • 51
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    Molecular and cellular biochemistry 146 (1995), S. 71-77 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; rat kidney cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The expression of calcium-binding protein regucalcin mRNA in the kidney cortex of rats was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin complementary DNA (0.9 kb of open-reading frame). Regucalcin mRNA was expressed in the kidney cortex, and this expression was clearly increased by a single intraperitoneal administration of calcium chloride solution (5–15 mg Ca/100 g body weight) in rats; this increase was remarkable at 60–120 min after the administration. Thyroparathyroidectomy (TPTX) caused a slight decrease of regucalcin mRNA levels in the kidney cortex. However, the administration of calcium (10 mg/100 g) in TPTX rats produced a clear increase of regucalcin mRNA levels in the kidney cortex. The subcutaneous administration of calcitonin (10–100 MRC mU/100 g) or parathyroid hormone [1–34] (1–10 U/100 g) in TPTX rats which received calcium (10 mg/100 g) administration did not cause an appreciable alteration of regucalcin mRNA levels in the kidney cortex, suggesting that the mRNA expression is not stimulated by calcium-regulating hormones. The administration of trifluoperazine (TFP; 5 mg/100 g), an inhibitor of Ca2+/calmodulin action, completely blocked the expression of regucalcin mRNA stimulated by calcium administration. Now, calcium content in the kidney cortex was significantly elevated by a single intraperitpneal administration of calcium (10 mg/100 g) in rats. The present study clearly demonstrates that the expression of regucalcin mRNA in the kidney cortex is stimulated by calcium administration in rats. This expression may be mediated through Ca2+/calmodulin action in the kidney cortex.
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  • 52
    ISSN: 1573-4919
    Keywords: fatty acid transport protein ; gene expression ; subtractive hybridization ; oxidative stress ; ischemia/reperfusion ; ischemic preconditioning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract In this study, ischemia and oxidative stress-inducible gene expression in heart was examined by subtractive hybridization technique. Total RNA was isolated from ventricular muscle fragments of normal and oxidative stress-induced hearts. Poly (A)+ RNA was purified followed by the construction of a plasmid cDNA library. This was followed by the subtractive screening of oxidative stress-induced cDNA library. The positive colonies were amplified and the plasmid isolated. An aliquot was subjected to restriction cutting with Bam H1 and EcoRl; the fragments corresponding to cDNA insert were separated by electrophoresis, radiolabeled by random-primed DNA synthesis, and used as probes in standard Northern blotting experiments. An aliquot containing the plasmid from the confirmed positives was then subjected to bidirectional partial DNA sequencing (using M13 and T7/T3α primers) by the chain-extension/chain termination method. These sequences were subjected to a computerized search for homologies against all sequences in the updated worldwide Gen Bank and EMBL sequence databases followed by restriction mapping and reading frame identification. Out of 24 putative positive colonies screened, one clone was matched with 〉 97% homology with FAT gene that has been implicated in binding or transport of long chain fatty acids. cDNA probe synthesized from this clone identified two major transcripts of 4.8 and 2.9 kb. Additional experiments were then performed where isolated perfused rat hearts were subjected to the following treatments: (1) 5 min ischemia; (2) 10 min ischemia; (3) 20 min ischemia; (4) 5 min ischemia followed by 10 min reperfusion (ischemic preconditioning); and (5) 5 min ischemia followed by 10 min reperfusion, repeated four times (4 × preconditioning). RNAs were extracted from these hearts and hybridized with the FAT cDNA probe. The results indicated that FAT gene was induced by oxidative stress, ischemic preconditioning, but not by ischemia. (Mol Cell Biochem 160/161: 241–247, 1996)
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  • 53
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    Keywords: regucalcin ; calcium-binding protein ; gene expression ; diabetic state ; ethanol ; liver injury
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The alteration in calcium-binding protein regucalcin in the liver and serum of rats with streptozotocin (STZ)-diabetic state or ethanol ingestion was investigated. STZ (6.0 mg/100 g body weight) was subcutaneously administered in rats, and 1 or 3 weeks later they were sacrificed by bleeding. Liver regucalcin mRNA levels were not clearly altered by the diabetic state, as evidenced by Northern blotting using regucalcin cDNA (0.9 kb of open reading frame). Based on enzyme-linked immunoadsorbent assay (ELISA) with rabbit-anti-regucalcin IgG, hepatic regucalcin concentration was decreased about 50% of control levels by STZ treatment. However, serum regucalcin concentration was not significantly altered by STZ treatment. Meanwhile, when rats ingested ethanol (10 and 30%) in the drinking water for 2 weeks, liver regucalcin mRNA levels were clearly increased, although hepatic regucalcin concentration was significantly decreased. Serum regucalcin concentration was not appreciably altered. Serum transaminases (GOT and GPT) activities were significantly increased at 1 or 3 weeks after STZ administration in rats, while their activities were not altered by ethanol ingestion. The present study demonstrates that hepatic regucalcin concentration is decreased independent of mRNA expression in the STZ-diabetes and during ethanol ingestion in rats.
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  • 54
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    Molecular and cellular biochemistry 163-164 (1996), S. 231-237 
    ISSN: 1573-4919
    Keywords: extracellular matrix ; angiotensin II ; fibrillar collagen ; cardiac fibrosis ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Recent studies suggest that angiotensin II (angiotensin) may be involved in the regulation of metabolism of the cardiac extracellular matrix (ECM). Two major components of ECM are collagen types I and III which play an important role in maintaining the structure and function of the heart. Although the cellular metabolism of collagen is very complex (especially at the posttranslational level), we chose to address events that occur relatively early in the synthesis of cardiac collagen molecules. To gain an understanding of the role of angiotensin in the regulation of cardiac collagen gene expression, we studied the effect of three different doses of angiotensin (12, 24, and 48 μg/kg/h) on adult heart and cultured neonatal cardiac fibroblasts. The steady-state mRNA abundance of collagen types I and III was monitored using Northern blot analysis in both left and right ventricular samples at day 3 of angiotensin infusion and in cultured cardiac fibroblasts stimulated with angiotensin. In all mRNA abundance studies, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) signal was used to normalize the data for possible differences in loading and/or transfer of total RNA. Both collagen types I/GAPDH and III/GAPDH mRNA signal ratios were increased significantly in left ventricle in all dose regimens used for angiotensin infusion. Only the collagen type I/GAPDH mRNA signal ratio was increased in right ventricle with angiotensin infusion. Angiotensin (10−7-10−5 M) had no effect on the steady-state mRNA abundance of collagen genes in cultured neonatal cardiac fibroblasts after 24 h treatment in serum-free conditions. Our results confirm that infusion of angiotensin may upregulate steady-state collagen gene mRNA abundance in the heart. Angiotensin had no observable effect on collagen mRNA abundance in neonatal fibroblast culture. An explanation for the current results may be that angiotensin causes the release of undefined factors from cardiac myocytes, and that these secondary factors may be involved in either the activation of collagen gene transcription or in alteration of stability of collagen mRNA transcripts via a paracrine mechanism. Although our results indicate hemodynamic loading may potentiate the action of angiotensin, this scenario is unlikely as collagen type I gene expression was increased in the normotensive right ventricle.
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  • 55
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    Molecular and cellular biochemistry 167 (1997), S. 169-177 
    ISSN: 1573-4919
    Keywords: tamoxifen ; interferon ; gene expression ; breast cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The molecular basis for the enhanced growth inhibition of MCF-7 human breast cancer xenografts by a combination of human interferon-β (IFN-β) and tamoxifen was investigated. Treatment of MCF-7, MDA-MB-231, and BT-20 cells with the combination of IFN-β and tamoxifen resulted in enhanced antiproliferative effects in vitro. Treatment with the combination of IFN-β and tamoxifen enhanced the expression of several IFN-β-inducible genes in human breast carcinoma cell lines relative to levels induced by IFN-β alone. Tamoxifen alone did not induce transcription of IFN-stimulated genes (ISGs). Augmentation of ISG expression by the combination of IFN-β and tamoxifen was noted in breast tumor cell lines irrespective of their functional estrogen receptor (ER) status or their dependence on estradiol for growth, suggesting that upregulation of ISGs was independent of ER status. Enhancement of IFN-stimulated gene expression by tamoxifen occurred at the transcripti onal level. Expression of transfected reporter genes under the control of IFN-α/β regulated promoters was also enhanced in IFN-β and tamoxifen-treated cells. Similarly, transcriptional induction of chimeric reporter plasmids driven by an IFN-γ inducible promoter (GAS; IFN-γ activated site) was also enhanced by the combination of IFN-γ and tamoxifen. In tamoxifen treated cells, IFN-β and IFN-γ readily activated transcription factors ISGF-3 and GAF, respectively. Therefore, augmentation of ISG expression by tamoxifen is an early event in the antitumoral activity of this drug combination. (Mol Cell Biochem 167: 169-177, 1997)
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  • 56
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    Molecular and cellular biochemistry 172 (1997), S. 47-57 
    ISSN: 1573-4919
    Keywords: smooth muscle ; gene transfer ; DNA ; RNA ; ribozyme ; liposome ; lipoxygenase ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Chemically synthesized hammerhead-type ribozymes targeted against the porcine leukocyte-type 12-lipoxygenase (LO) have been developed and studied. One chimeric ribozyme consists of DNA in the non-enzymatic portions, and RNA in the enzymatic core as well as two phosphorothioate internucleotide linkages at 3′ terminus. The second ribozyme consists of ribonucleotide sequences generated by in vitro transcription. In this chapter we describe methodologies to first analyze the ribozyme catalytic activity in vitro by studying cleavage of target RNA in vitro. The subsequent sections will describe how to target the catalytic ribozyme and deliver it to porcine vascular smooth muscle cells (PVSMC) by a liposome-mediated method. Finally ways to evaluate its activity to inhibit expression of the 12-LO mRNA will be presented. These results demonstrate the feasibility of using ribozymes as novel candidates for therapeutic agents to block specific gene expression in vascular cells.
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  • 57
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    Keywords: heart ; DNA ; library ; gene expression
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The availability of high quality cDNA libraries is often crucial to the successful identification and characterization of genes. The concepts and potential pitfalls of constructing cDNA libraries are presented. Various applications requiring high quality cDNA libraries are outlined, including large-scale single pass sequencing of cDNA clones to generate expressed sequence tags (ESTs) and differential screening of cDNA libraries. The usefulness of combining such approaches for the discovery of novel disease-related and cardiovascular-based ESTs (CVBest) is discussed.
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  • 58
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    Molecular and cellular biochemistry 173 (1997), S. 59-69 
    ISSN: 1573-4919
    Keywords: hydrogen peroxide ; oxidative stress ; gene expression ; lens epithelial cells ; N-acetylcysteine ; pyrrolidine dithiocarbamate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The involvement of H2O2 in cataract development has been established inboth human patients and animal models. At the molecular level H2O2 has beenobserved to cause damage to DNA, protein and lipid. To explore the oxidativestress response of the lens system at the gene expression level, we haveexamined the effects of H2O2 on the mRNA change of the proto-oncogenes,c-jun, c-fos and c-myc in a rabbit lens cell line, N/N1003A. H2O2 treatmentof the rabbit lens epithelial cells for 60 min induces quick up-regulationof both c-jun and c-fos mRNAs. The maximal induction is 38 fold for c-jun at150 µM and 72 fold for c-fos at 250 µM H2O2. Treatment ofN/N1003A cells with 50-250 µM H2O2 for 60 min leads to a 2-5 foldincrease of the c-myc mRNA level. H2O2 also induces an up-regulation intransactivity of the activating protein-1 (AP-1) as shown with a reportergene driven by a prolactin gene promoter with 4 copies of AP-1 binding sitesinserted in the upstream of the promoter. Maximal induction occurs with 150µM H2O2. In the same system, the antioxidants, N-acetyl-cysteine (NAC)and pyrrolidine dithiocarbamate (PDTC) at concentrations shown toup-regulate the mRNAs of both c-jun and c-fos, also enhance thetransactivity of AP-1. NAC and PDTC have different effects in modulating theinduction of AP-1 activity by H2O2 and TPA. These results reveal thatoxidative stress regulates expression of various regulatory genes in lenssystems, which likely affects cell proliferation, differentiation andviability and thus affect normal lens functions.
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  • 59
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; cDNA cloning ; gene expression ; mouse liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The molecular cloning of the cDNA coding for a Ca2+-binding proteinregucalcin and its mRNA expression in mouse liver were investigated. ThecDNA clone encoding a regucalcin was isolated from a mouse liver cDNAlibrary and sequenced. Analysis of the sequence of the cloned cDNA showedthat the cDNA encoded the complete amino acid sequence of the mouseregucalcin molecule; the cDNA had an open reading frame of 897 bp. Mouseregucalcin was composed of 299 amino acid residues, and its molecular weightwas estimated to be 33,406 Da. The amino acid sequence of mouse regucalcinhad 94% homology, as compared with that of rat regucalcin. Northernblot analysis with the mouse liver cDNA probe revealed that mouse regucalcinmRNA was mainly present in the liver but only slightly in the kidney with asize of 1.8 kb. Hepatic regucalcin mRNA level of male mouse was higher thanthat of female mouse. A single intraperitoneal administration of calciumchloride (5, 15, and 30 mg Ca2+/100 g body weight) to mice induced aremarkable increase in regucalcin mRNA in the liver; the increase inregucalcin mRNA levels at 30 min after calcium administration wasdose-dependent. The present results demonstrate that regucalcin mRNA in miceis uniquely expressed in the liver, and that its expression is stimulated bycalcium administration.
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  • 60
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    Molecular and cellular biochemistry 176 (1997), S. 273-279 
    ISSN: 1573-4919
    Keywords: cardiac hypertrophy ; myosin heavy chain ; gene expression ; adrenergic system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Growth of the heart in hypertrophy is accompanied by changes in the phenotypic expression of cardiac genes. To explore the molecular basis of cardiac hypertrophy, we have analyzed the regulation of myosin heavy chain gene (MHC) expression. In one set of experiments, pressure overload on the rat heart was produced by constriction of the abdominal aorta. Changes in the α and β-MHC mRNA were then studied in overloaded hearts and following load removal. Pressure overload resulted in down-regulation of the α-MHC with corresponding up-regulation of the steady state level of β-MHC mRNA. Load removal (debanding) resulted in regression of cardiac hypertrophy and a rapid return of α-MHC mRNA to normal values. In contrast, the recovery in β-MHC mRNA was much slower to the extent that it remained substantially elevated compared to respective sham controls even after 7 weeks of post-debanding. These results suggest that putative load-related signals independently regulate two genes. Several lines of evidence indicate that adrenergic nervous system plays an important role in the induction and maintenance of cardiac hypertrophy and in the redistribution of myosin isoforms. We have analyzed the effect of cAMP inducing agents on the regulation of a-MHC gene in primary cultures of the fetal (18 day) rat cardiac myocyte. Inclusion of 8 Br-cAMP in the culture media increased the expression of α-MHC promoter/reporter construct comprising of 2.9 kb upstream sequence of the α-MHC gene. Several deletion mutations in the α- MHC gene promoter defined the cAMP responsive boundaries to be a 32 bp region comprising of -71 to -40 bp sequences. Deletion of this region resulted in loss of cAMP response as well as in basal expression of α-MHC promoter/reporter construct. These data suggest a role of β-adrenergic pathway in the modulation of α-MHC gene expression.
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  • 61
    ISSN: 1573-4919
    Keywords: regucalcin ; Ca2+-binding protein ; protein kinase C ; Ca2+signaling ; gene expression ; H4-II-E hepatoma cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The expression of hepatic Ca2+-binding protein regucalcin in the cloned rat hepatoma cells (H4-II-E) was investigated. The change in regucalcin mRNA levels was analyzed by Northern blotting using rat liver regucalcin complementary DNA (0.9 kb of open reading frame). Regucalcin mRNA was expressed in H4-II-E hepatoma cells. This expression was clearly stimulated in the presence of serum (10% fetal bovine serum). Bay K 8644 (2. 5 × 10-6 M), a Ca2+ channel agonist, significantly stimulated regucalcin mRNA expression in the absence or presence of 10% serum. Dibutyryl cyclic AMP (10-3 M) did not have a stimulatory effect on the regucalcin mRNA expression. The presence of phorbol 12-myristate 13-acetate (PMA; 10-6 M) or estrogen (10-8 M) caused a significant increase in regucalcin mRNA levels in the hepatoma cells cultured in serum-free medium, while insulin (5 × 10-9 M) or dexamethasone (10-6 M) had no effect. Bay K 8644-stimulated regucalcin mRNA expression in the hepatoma cells was completely blocked in the presence of trifluoperazine (10-5 M), an antagonist of calmodulin, or staurosporine (10-7 M), an inhibitor of protein kinase C. The stimulatory effect of PMA was clearly inhibited in the presence of stauroporine. The present study demonstrates that regucalcin mRNA is expressed in the transformed H4-II-E hepatoma cells, and that the expression is stimulated through Ca2+-dependent signaling factors.
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  • 62
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    Molecular and cellular biochemistry 199 (1999), S. 189-200 
    ISSN: 1573-4919
    Keywords: lung ; cancer ; urokinase ; receptor ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The urokinase-type plasminogen activator (uPA) interacts with its receptor (uPAR) to promote proteolysis as well as cell proliferation and migration. These functions contribute to the pathogenesis of neoplastic growth and invasiveness. Expression of uPAR in tumor extracts also inversely correlates with prognosis in many forms of cancer. In this study, we sought to determine if differences in uPAR expression were distinguishable between cultured human lung carcinoma and malignant mesothelioma subtypes. We also sought to determine if, as in malignant mesothelioma cells, uPAR expression is regulated at the posttranscriptional level in cultured malignant lung carcinoma cells. Using 125I-uPA binding and ligand blotting techniques, uPAR was expressed by phenotypically diverse lung carcinoma cell lines, including the H460, H157 and H1395 non-small cell lines and the H146 small cell lung carcinoma line. Increased uPAR expression was also detected in spindle-shaped (M33K) and epithelioid (M9K and MS-1) malignant mesothelioma cells. Selected mediators, including TGF-β, TNF-α, LPS and PMA, uniformly enhanced uPAR expression in each of the tumor cell lines. Steady state uPAR mRNA expression was determined by RNase protection assay and correlated directly with the changes in cell surface uPAR expression. By gel mobility shift and UV-cross linking assays, a uPAR mRNA binding protein (uPAR mRNABp) implicated in the posttranscriptional control of message stability, was identified in each of the cell lines. Expression of uPAR and its message in cultured lung carcinoma and malignant mesothelioma cells is similarly influenced by effectors present in the tumor microenvironment. Regulation of the uPAR message occurs at the posttranscriptional level in cultured small and non-small cell lung carcinoma cells as well as spindle-shaped and fibrous malignant mesothelioma cell lines. Posttranscriptional regulation of uPAR in all these cells involves the interaction of the uPAR mRNABp with uPAR mRNA, which promotes uPAR mRNA destabilization.
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  • 63
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    Biochemical genetics 18 (1980), S. 353-364 
    ISSN: 1573-4927
    Keywords: carboxylesterase ; electrophoretic variants ; fish development ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two esterases splitting α-naphthylacetate have been found in the tissues of adult loaches and in embryos. These were identified as arylesterase (E-1) (arylester hydrolase, E.C. 3.1.1.2) and carboxylesterase (E-2) (carboxylic ester hydrolase, E.C. 3.1.1.1.). In unfertilized loach eggs E-1 and E-2 synthesized during oogenesis were found. Active E-2 synthesized under the control of E-2 genes of the embryo appeared in embryos from the stage of 40–50 h of development. Maternal E-2 molecules synthesized in oogenesis or on the stored templates in embryogenesis persisted in larvae up to days 5–6 of development. Two genes controlling the synthesis of two forms of E-2 differing in electric mobility were found in the loach population from the delta of the Danube. The genes for fast and slow E-2 were shown to segregate in meiosis and to be allelic.
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  • 64
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    Biochemical genetics 19 (1981), S. 237-254 
    ISSN: 1573-4927
    Keywords: wheat ; barley ; addition lines ; isozymes ; genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Zymogram analysis was used to identify the barley chromosomes that carry the structural genes for particular isozymes. Wheat, barley, and wheatbarley hybrid derivative lines (which contained identified barley chromosomes) were tested by gel electrophoresis for isozymes of particular enzymes. It was found that barley chromosome 4 carries structural genes for acid phosphatase and β amylase isozymes, barley chromosome 5 carries genes for phosphoglucose isomerase and malate dehydrogenase isozymes, and that barley chromosome 2 carries a gene for at least one glucose-6-phosphate dehydrogenase protomer. These results reinforce previous conclusions that barley chromosome 4 shows homoeology with wheat chromosome group 4 and that barley chromosome 5 shows homoeology with wheat chromosome group 1.
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  • 65
    ISSN: 1573-4927
    Keywords: glycophorins ; gorilla ; evolution ; gene family ; gene expression
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Homologues of MN blood group antigens, encoded by members of the glycophorin A (GPA) gene family, are expressed in man, anthropoid apes, and some species of Old World monkeys. Previous studies had shown that a three-gene framework, most closely related to that in man, is present in the chimpanzee. Here we report the genomic structure, transcript map, and protein expression of the GYPA locus in gorillas. Compared to the corresponding human and chimpanzee homologues, gorilla GPA, GPB, and GPB/E genes each showed a high degree of sequence identity, with the same exon-intron organization. However, the expression of exons III, IV, or V encoding the extracellular or membrane domains of homologous glycophorins varied among the three species. Gorilla GPA and GPB/E genes were unique in that the former occurred in two allelic forms with or without the expression of exon III, whereas the latter contained one (ψ exon III) instead of two silenced exons (ψ exons III and IV). Differences from human but not chimpanzee GPA also included the presence of a hybrid M/N epitope and the absence of the sequon for N-glycosylation. Owing to the retention of a functional exon III, gorilla GPB was more similar to chimpanzee GPB than human GPB. A transspecies allele was identified in the gorilla that gave rise to the Henshaw (He)-like antigen similar to that found in man. These results provide further insight into the model for evolution of the GPA gene family, indicating that the mechanisms underlying inter- and intraspecific polymorphism of glycophorins could predate the divergence of gorillas as the consequence of gene duplication and diversification.
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  • 66
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    Molecular and cellular biochemistry 172 (1997), S. 37-46 
    ISSN: 1573-4919
    Keywords: gene transfer ; gene expression ; adenovirus ; blood vessel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Adenovirus-mediated gene transfer is a promising method for studies of vascular biology and potentially for gene therapy. Intravascular approaches for gene transfer to blood vessels in vivo generally require interruption of blood flow and have several limitations. We have used two alternative approaches for gene transfer to blood vessels in vivo using perivascular application of vectors. First, replication-deficient adenovirus expressing nuclear-targeted bacterial b-galactosidase was injected into cerebrospinal fluid via the cisterna magna of rats. Leptomeningeal cells over the major arteries were efficiently transfected, and adventitial cells of large vessels and smooth muscle cells of small vessels were occasionally stained. When viral suspension was injected with the rat in a lateral position, the reporter gene was expressed extensively on the ipsilateral surface of the brain. Thus, adenovirus injected into cerebrospinal fluid provides gene transfer in vivo to cerebral blood vessels and, with greater efficiency, to perivascular tissue. Furthermore, positioning of the head may ‘target’ specific regions of the brain. Second, vascular gene delivery was accomplished by perivascular injection of virus in peripheral vessels. Injection of the adenoviral vector within the periarterial sheath of monkeys resulted in gene transfer to the vessel wall that was substantial in magnitude although limited to cells in the adventitia. Approximately20% of adventitial cells expressed the transgene, with no gene transfer to cells in the intima or media. These approaches may provide alternative approaches for gene transfer to blood vessels, and may be useful for studies of vascular biology and perhaps vascular gene therapy.
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  • 67
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    Molecular and cellular biochemistry 172 (1997), S. 111-120 
    ISSN: 1573-4919
    Keywords: differential display ; cardiac development ; gene expression
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract An estimated 15,000 different mRNA species are expressed in a typical mammalian cell. The differential expression of mRNAs in both a temporal and cell-specific manner determines the fate of the cell and creates the organism. Analysis of this differential gene expression has become a central aim of many laboratories attempting to understand the mechanisms underlying various biological processes. Currently, we are using a technique called differential display to analyze the differential expression of genes in cardiomyocytes. Differential display is a rapid and powerful technique that was introduced by Liang and Pardee in 1992. Since that time, it has been successfully applied by several groups, and it is quickly becoming a standard method for studying differential gene expression. Here, we present a detailed article discussing the differential display methodology and how we have utilized it to identify potential genes involved in cardiomyocyte proliferation. Furthermore, we have provided a list of materials and supplied examples of data obtained, in an effort to allow the reader to perform the technique with success in their own laboratory.
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  • 68
    ISSN: 1573-4919
    Keywords: plasminogen activators ; plasminogen activator inhibitors ; gene expression ; left ventricular hypertrophy ; pressure overload
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract In the early stages of left ventricular hypertrophy (LVH) acute adaptive changes occur in the coronary vasculature as it remodels. Plasminogen activators (PAs) and inhibitors (PAIs) have the potential effects of proteolytic degradation that is relevant to tissue remodeling and angiogenesis. Our study focused on the possible roles of PAI-1, PAI-2, uPA and tPA in myocyte hypertrophy and angiogenesis in the early and late stages of pressure overload induced left ventricular hypertrophy (LVH). We divided seventeen adult swine, weighing 24.2 ± 6.5 kg, into four groups: control, sham-operated, early LVH and late heart failure LVH group. At surgery we placed a fixed constrictor on the ascending aorta immediately above the aortic valve. This increased LV systolic pressure from 133 ± 15 to 193 ± 24 mm Hg after the surgery. We subdivided the early group into groups of 3 animals each that we euthanized at 8, 24 and 72 h after operation and obtained heart samples for analysis. In the late heart failure group individual animals were euthanized at 55, 59, 62 and 72 days after the detection of congestive heart failure. We also obtained tissue samples from the control and sham-operated swine. Sections for histologic analysis were fixed in 10% buffered formalin. We isolated RNA, size fractionated it using 1% formaldehyde-agarose gel electrophoresis and then did Northern blots. The mRNAs from both PAI-1 and PAI-2 showed a remarkable increase at 8 and 24 h after acute aortic constriction and returned to control by 72 h. Regional differences showed that most of the increases were in the endocardium. Three animals in the late heart failure LVH group were determined to be in congestive heart failure at about 2 months after the onset of aortic constriction. In these animals PAI-1 and PAI-2 were increased in both the left and right ventricles but remained low in an animal of the same elevation in aortic pressure seen by the LV who did not have congestive failure. These data suggest that PA and PAI gene expressions change before morphologic changes occur in the early stages of developing LVH. Also at the time of onset of congestive heart failure this increased expression reappears. PAs and PA inhibitors mRNA levels vary in the different regions of the heart reflecting changing wall stresses. Thus, the PAs and PA inhibitors may play an important role in angiogenesis that occurs during the early stages of LVH. The increased expression in the late stage of LVH may reflect further changes in wall stresses since these animals also showed overt clinical signs of heart failure.
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  • 69
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    Molecular and cellular biochemistry 178 (1998), S. 157-162 
    ISSN: 1573-4919
    Keywords: protein tyrosine phosphatases ; gene expression ; degenerate deoxyoligonucleotides ; RT-PCR ; Swiss 3T3 fibroblasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The aim of this study was to identify protein tyrosine phosphatases (PTPs) expressed in Swiss 3T3 fibroblasts and to examine their expression levels as well as to characterize quantitative aspects of RT-PCR based on degenerate deoxyoligonucleotides. By using an RT-PCR assay based on degenerate deoxyoligonucleotide primers, expression of mRNAs for two cytoplasmic- and six transmembrane-type PTPs in Swiss 3T3 cells was detected. The sequences of two of them are new. Among nine analyzed PTPs expressed to widely varied extends, only three have mRNA levels high enough to be seen on Northern blots with 10 µg of total RNA per lane. The frequencies with which the examined PTPs are represented among the PCR amplification products, correlate stronger with the primer fidelity, defined as the number of mismatches between the primer- and the cDNA target-sequences, rather than with the PTP expression levels. In conclusion, an RT-PCR assay based on degenerate primers can be successfully used to sample the expressed PTPs and to identify new members of this gene family. However, reliable quantification of their mRNA levels can only be achieved using the classical approaches, like Northern, RNase protection assay or non-degenerate quantitative RT-PCR.
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    Molecular and cellular biochemistry 162 (1996), S. 51-58 
    ISSN: 1573-4919
    Keywords: metabolism ; glucose transporter ; adipocytes ; gene expression
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract We tested the hypothesis that the constitutive glucose transporter (GLUT 1) in 3T3-L 1 adipocytes belongs to the family of glucose-regulated proteins which are transcriptionally regulated by glucose deprivation. Using cDNA probes for both GRP78 (BiP) and GLUT1, we show that the level of GRP78 mRNA increased by 15-fold within 24 h of glucose deprivation with little change in GLUT1 mRNA. The elevated GRP78 mRNA in turn led to a time-dependent increase in GRP78 protein. While glucose deprivation did not alter the expression of the normal glycoform of GLUT 1, a lower molecular weight glycoform accumulated with extended deprivation. Mannose and fructose, but not galactose, prevented the induction of GRP78 and accumulation of the abnormal GLUT1. Because GRP78 acts as a chaperone in other cell systems, we also sought evidence to support this activity in 3T3-L1 adipocytes. Using the technique of co-immunoprecipitation, we demonstrate that GRP78 bound several proteins unique to the glucose-deprived state. No deprivation-specific proteins could be detected in association with GLUT 1. These data lead us to conclude that GLUTl does not display characteristics of the glucose-regulated proteins, at least in 3T3-L1 adipocytes, a widely used model for differentiation, hormone action, and nutrient control. However, the mechanisms for activating traditional members of this family appear intact.
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  • 71
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    Molecular and cellular biochemistry 186 (1998), S. 43-51 
    ISSN: 1573-4919
    Keywords: myocardial ischemia ; gene expression ; growth factors ; phospholamban ; calsequestrin heat shock proteins ; preconditioning ; stunning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Brief periods of coronary occlusion render the affected myocardium more tolarant to the otherwise devastating effects of long coronary occlusion. Besides this phenomena, called ischemic preconditioning, short periods of ischemia cause a regional dysfunction, namely myocardial stunning. The molecular mechanisms of both syndromes are not very well understood. We therefore investigated the expression of genes which may be involved in cardioprotection or repair processes.Using our porcine model of ischemia and reperfusion we were able to show an induction of genes coding for transcription factors (proto-oncogenes), for proteins involved in repair processes (heat shock genes), for proteins implicated in the calcium homeostasis (calcium-handling genes) and for growth factors. We could show that the increased mRNA levels are due to an enhanced transcriptional activity and not to a prolonged half-life of the transcripts. The angiogenic growth factor vascular endothelial growth factor (VEGF) represents an exception. It exhibits - in addition to a HIF-motif (Hypoxia Inducible Factor) in its promoter/enhancer - a protein binding region in its 3′ UTR which when occupied renders the mRNA more stable. However to what extent the expression of the distinct genes contributes to the cardioprotective effect of ischemic preconditioning or myocardial stunning can only be presumed. Increased mRNA stability can be confered via adenosine which is produced during ischemia by ATP-breakdown. The demasking of unknown genes - via differential display reverse transcription polymerase chain reaction (DDRT-PCR) - should provide a more comprehensive view of the mechanisms underlying both processes.
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    Molecular and cellular biochemistry 201 (1999), S. 111-123 
    ISSN: 1573-4919
    Keywords: complement factor I ; TPA ; protein kinase C ; gene expression ; Hep G2 cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract This study examined the role of the protein kinase C (PKC) signalling pathway in the regulation of expression of human complement factor I (CFI) gene. The production of CFI by Hep G2 cells was enhanced in a dose- and time-dependent fashion by 12-O-tetradecanoyl-1,2-phorbol 13-acetate (TPA), a potent PKC activator. 4α-phorbol didecanoate, an inactive phorbol ester, had no effect on CFI synthesis. The TPA-dependent increase in CFI secretion was correlated with an increase in CFI mRNA levels. Forskolin, a cAMP-inducing agent, augmented the TPA response. W7, an inhibitor of protein kinase A and genistein, an inhibitor of protein tyrosine kinase(s) both did not prevent the increase in CFI expression mediated by TPA. However, calphostin C, a specific inhibitor of PKC, abolished the TPA-induced increase in CFI mRNA levels. Down regulation of intracellular PKC levels by prior exposure of Hep G2 cells to a high concentration of TPA also blocked the increase in CFI mRNA levels induced by TPA suggesting that the TPA effects were mediated via activation of PKC. mRNA decay studies indicated that the half-life of CFI mRNA in TPA-induced cells was not significantly different from control. Nuclear run-on transcriptional assays on the other hand demonstrated that whereas the CFI gene is transcribed under basal conditions in Hep G2 cells, TPA induced a 3-4 fold increase in the transcription rate of CFI gene in 24 h. The transcription rate of GAPDH gene did not change, indicating that the effects were not general on gene transcription. Transient transfections of Hep G2 cells with chloramphenicol acetyltransferase reporter gene (CAT) constructs containing a series of sequential 5′ deletions of the CFI promoter and CAT assays showed that the sequence between -136 and -130, containing an AP-1 consensus sequence (TGAGTCA) was required for the TPA response. This observation was substantiated by the finding that mutation of this AP-1 site to TttaTCA or TtAtcCA abolished the TPA responsiveness. The enhancement of the activity of transfected chimeric CAT constructs by TPA was abrogated by calphostin C and by pyrrolidine dithiocarbamate (an inhibitor of NF-κB and AP-1 transactivation). These results indicate that TPA regulation of CFI gene requires PKC signalling and is mediated by via a TPA response element (TRE) in the CFI promoter region located at -136/-130 and involves the transactivation of AP-1 and NF-κB transcription factors. We suggest that PKC may be one of the intracellular pathways that control CFI gene expression and that cellular processes (involving growth factors, hormones, cytokines etc.) that activate PKC may upregulate the expression of the CFI gene.
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  • 73
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; Ca2+-ATPase ; brain microsomes ; aging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The expression of calcium-binding protein regucalcin and its effect on the microsomal Ca2+-ATPase activity in rat brain tissues was investigated. The expression of regucalcin mRNA was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) analysis in brain tissues using rat regucalcin-specific primers. Regucalcin concentration in the brain tissues was about 5 × 10-9 M as measured using enzyme-linked immunoadsorbent assay (ELISA), and this level was lowered with increasing age (50 weeks old). The presence of regucalcin (10-9 to 10-7 M) in the enzyme reaction mixture caused a significant decrease in Ca2+-ATPase activity in the brain microsomes of young rats (5 weeks old). Meanwhile, the enzyme activity was not significantly altered by the addition of calmodulin (1 or 50 μg/ml), calbindin (1 or 10 μg/ml), and S-100 A protein (5 or 25 μg/ml), which are other Ca2+-binding proteins in rat brain. The effect of regucalcin to inhibit microsomal Ca2+-ATPase activity was weakened in the brain of rats with increasing age (50 weeks old). The present study demonstrates that regucalcin is expressed in the brain, and that it can uniquely inhibit Ca2+-ATPase activity in the brain microsomes of rats. The findings suggest that regucalcin plays a role in the regulation of microsomal Ca2+-ATPase activity in rat brain tissues.
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  • 74
    ISSN: 1573-4927
    Keywords: amphibian development ; allelic isozyme variants ; gene expression ; maternal effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The polymorphism of three enzymes [lactate dehydrogenase B (LDH-B), glucose-6-phosphate dehydrogenase, (G6PDH), and peptidase-1 (PEP-1)] in Pleurodeles waltl has allowed the expression of the corresponding loci to be followed during the development of spawnings arising from various crosses. A maternal effect lasting up to the late tail-bud stage (approx. stage 28) was shown for PEP-1. A similar situation was observed for LDH-B and G6PDH. The embryonic alleles present retarded expression: from about stage 28 for PEP-1 and G6PDH and from about stages 22 to 24 (the young tail-bud stage) for LDH-B.
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    Biochemical genetics 22 (1984), S. 901-911 
    ISSN: 1573-4927
    Keywords: cat hemoglobins ; cell-free translation ; polymorphism ; gene expression
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The molecular basis for the genetic control of variable proportions of the two hemoglobins in domestic cat blood was investigated. Both major hemoglobins of cat blood, HbA (α2β 2 A ) and HbB (α2β 2 B ), were synthesized in an mRNA-dependent rabbit reticulocyte system using poly(A)-RNA from cat reticulocyte polysomes as the source of the message. The relative amounts of HbA and HbB synthesized in the system were a function of the HbA/HbB phenotype of the cat from which the reticulocytes and poly(A)-RNA were obtained. Higher ratios of HbA/HbB synthesis were found when the source of poly(A)-RNA was the polysomes from a 90/10 (HbA/HbB) phenotype than when it was from a 50/50 (HbA/HbB) phenotype. These results indicate that the variable proportions of HbA and HbB found in the blood of different members of the cat population result from the genetic control of the relative amounts of functional βA and βB mRNA.
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  • 76
    ISSN: 1573-1561
    Keywords: Kairomone ; biological control ; cabbage ; wheat ; Diuraphis noxia ; Brevicoryne brassicae ; olfactometer ; infochemical ; preference ; host plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Diaeretiella rapae (M'Intosh) (Hymenoptera: Aphidiidae) is a parasitoid of several aphid species, including the Russian wheat aphid (RWA),Diuraphis noxia (Mordvilko), and the cabbage aphid (CA).Brevicoryne brassicae (L.). The response of matedD. rapae females to odors from wheat, cabbage, and plant-host complexes was investigated using a four-choice olfactometer. Experienced parasitoids, but not inexperienced females, responded positively to odors of the wheat-RWA complex in a no-choice test. In choice tests, experienced parasitoids did not respond to odors of uninfested cabbage and wheat leaves, but did respond positively to aphid-infested plants and to aphids alone. The response ofD. rapae to the cabbage-CA complex and to CA alone was significantly greater than to the wheat-RWA complex and RWA alone, suggesting an innate odor preference for crucifer-feeding aphids.
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    Journal of chemical ecology 23 (1997), S. 2695-2705 
    ISSN: 1573-1561
    Keywords: Defense ; herbivory ; aphids ; wheat ; Gramineae ; hydroxamic acids ; Defense theory ; Carbon/Nutrient theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Hydroxamic acids (Hx) are natural products of Gramineae that are associated with cereal resistance to pests. We aimed at characterizing the induction of Hx accumulation in seedlings of wheat,Triticum aestivum, by short-term infestation of the cereal aphid,Rhopalosiphum padi. A load of 25 aphids increased significantly the Hx levels in the infested primary leaf in comparison with control levels. Lower loads did not increase Hx concentration. Aphid infestation lasting 16 hr did not elicit induction of Hx, even after a time-lag of 32 hr to allow the expression of any induced response. Forty-eight hours was the minimum duration of aphid infestation required to trigger Hx induction. The age of the infested tissue (the primary leaf) did not affect induction. Similar increases of Hx were found in unfolding, expanding, and totally expanded primary leaves. It was determined that the regime of nutrient supply (N-intensive nutritive solutions at low and high concentration) to wheat seedlings had no effect on the magnitude of the aphid-induced Hx (N-based secondary metabolites). Results obtained are discussed in the framework of general theories of plant defense allocation.
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    Water, air & soil pollution 85 (1995), S. 1311-1316 
    ISSN: 1573-2932
    Keywords: Pakistan ; air pollution ; ozone ; nitrogen dioxide ; rice ; wheat ; filtration ; yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Open-top chambers ventilated with ambient or chiarcoal-filtered air were used to assess the impact of air pollution on the yield of local cultivars of wheat and rice, at a site on the outskirts of Lahore. At this location, 6-h mean O3 concentrations reach 60 ppb in certain months, and annual mean NO2 concentrations are 20–25 ppb. The experiments showed significant yield reduction in two successive seasons which ranged from 33% to 46% in wheat and from 37% to 51% in rice. The major yield parameter affected was the number of ears or panicles per plant, although there was also evidence of small effects on 1000 grain weight and on the number of grains per ear/panicle. These results have significance in terms of the maintenance of agricultural yields as pollution emissions rise in south and south-east Asia.
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    Water, air & soil pollution 85 (1995), S. 1461-1466 
    ISSN: 1573-2932
    Keywords: ozone ; wheat ; Triticum aestivum ; growth ; senescence ; biomass partitioning ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In closed-chamber fumigation experiments dry matter partitioning and chlorophyll fluorescence of wheat were studied, analysing the effects of ozone during different stages of plant development. Ozone causes enhanced leaf senescence, leading to a loss of green leaf area and, consequently to a decreased supply of assimilates, affecting (in increasing order of severeness) stem, ear and grain productivity because of reduced storage pools for translocation. Leaves of plants before shooting stage were most sensitive but the lack of green leaf area after ear emergence had the most pronounced effects on grain yield. Measurements of photochemical capacity showed that evidence for negative ozone effects could be found in changes of chlorophyll fluorescence parameters in leaf sections not yet showing visible ozone injury. Negative effects on photosynthesis were more distinct with increasing accumulated ozone dose, with increasing age of leaf tissue and with increasing ozone sensitivity of the cultivar. The changes in chlorophyll fluorescence are most likely to be explained by a decreased pool size of plastoquinones caused by ozone.
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  • 80
    ISSN: 1573-2932
    Keywords: Ozone ; wheat ; areal interpolation ; economics ; yield losses ; critical levels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In Britain wheat is an important crop accounting for 41% of the total cereal production. In this study ozone concentrations for 1989 estimated as described in Part 1 of the paper are integrated with the estimated wheat distribution to derive a detailed estimate of the impact of ozone on wheat yields at a fine spatial scale (1km × 1km). These data provide estimates for calculating regional and national yield losses. The methodology can be applied to other crop species. Recent research on a range of crops has established relationships between the economic yield loss for certain crops, including wheat, and ozone exposure. Exposure is described as the accumulated exposure above a threshold experienced during the daylight hours (AOT). Critical AOT values are derived from yield exposure relationships which show linear reductions of yield loss with increasing ozone concentrations. This study has made use of land cover data from remotely sensed imagery at 25m resolution and nationally collected agricultural statistics for counties. These data were combined using an areal interpolation technique to provide more spatially articulate estimates of the location and intensity of wheat production. The results demonstrate the economic importance of ozone as a pollutant. Wheat yield losses attributed to ozone vary between different parts of the country but, for years when ozone levels are high, yield losses are likely to be significant in some areas.
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  • 81
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    Molecular and cellular biochemistry 151 (1995), S. 55-60 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium ; gene expression ; kidney damage ; rat kidney cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The alteration of Ca2+-binding protein regucalcin mRNA expression in the kidney cortex of rats administered cisplatin and cephaloridine, which can induce kidney damage, was investigated. Cisplatin (0.25, 0.5 and 1.0 mg/100 g body weight) or cephaloridine (25, 50 and 100 mg/100 g) was intraperitoneally administered in rats, and 1, 2 and 3 days later they were sacrificed. The alteration in serum findings after the administration of cisplatin (1.0 mg/100 g) or cephaloridine (50 and 100 mg/100 g) demonstrated chemically induced kidney damage; blood urea nitrogen (BUN) concentration increased markedly and serum inorganic phosphorus or calcium concentration decreased significantly. Moreover, the administration of cisplatin (1.0 mg/100 g) or cephaloridine (100 mg/100 g) caused a remarkable increase of calcium content in the kidney cortex of rats, indicating kidney damage. The expression of regucalcin mRNA in the kidney cortex was markedly reduced by the administration of cisplatin or cephaloridine in rats, when the mRNA levels were analyzed by Northern blotting using rat liver regucalcin cDNA (0.9 kb). The mRNA decreases were seen with the used lowest dose of cisplatin or cephaloridine. The present study clearly demonstrates that the mRNA expression of Ca2+-binding protein regucalcin in the kidney cortex of rats is decreased by chemically induced kidney damage.
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  • 82
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    Molecular and cellular biochemistry 152 (1995), S. 131-141 
    ISSN: 1573-4919
    Keywords: gene expression ; mRNA ; proto-oncogenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Polyomavirus large T-antigen transgenic mice develop cardiac hypertrophy characterized by an increase in atrial natriuretic factor and β-myosin heavy chain isoform expression. The aim of this study was to examine changes in proto-oncogene expression in hypertrophied hearts from the transgenic mice. Expression of early growth response-1 (Egr-1) mRNA was detected in hearts from all 15 transgenic mice, but was not detectable in 13 control mice. Reverse transcriptase-polymerase chain reaction experiments usingEgr-1-specific primers confirmed the increase inEgr-1 mRNA in enlarged hearts from the transgenic mice. Expression of c-jun,junD and Ha-ras mRNAs was increased in the transgenic hearts 3, 17 and 2.8-fold, respectively. Western blots showed an increase in c-myc, c-jun and ras protein in hypertrophied transgenic hearts. Immunofluorescence analyses confirmed an increase in Egr-1 and c-jun protein in transgenic cardiomyocytes. Proliferating cell nuclear antigen, Ki-ras and HSP 90 mRNAs were decreased 22, 2.7 and 3-fold, respectively in the transgenic hearts. Not altered in most hypertrophied hearts was expression of c-fos, junB, p53, c-neu, c-myc, HSP70, HSP27, TGF-β or IGF-1 mRNAs. Proto-oncogene and growth factor gene expression in hypertrophy induced by PVLT expression is modulated, with some proto-oncogenes increased and others decreased in expression.
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  • 83
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    Molecular and cellular biochemistry 154 (1996), S. 65-70 
    ISSN: 1573-4919
    Keywords: gene expression ; regulatory elements ; plasmid ; oligonucleotides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract A potentially powerful pharmacological approach to modulating the expression of specific, disease-related genes involves the inhibition of transcription factor binding to promoter or enhancer elements through oligonucleotide-mediated triple-helix formation. In vivo, the typical target for intermolecular triplex formation would most likely be torsionally-strained rather than relaxed duplex DNA. To determine the effects of strained DNA on triplex formation, we investigated the interactions between a G/T rich oligonucleotide and both supercoiled and relaxed plasmid DNA using a restriction endonuclease protection assay. Both the kinetics of formation and dissociation of purine-motif triplexes were unaffected by the conformational state of the duplex DNA. Similarly, the topological state of the plasmid targets was not affected by triplex formation. Taken together, these observations suggest that stable intermolecular triplexes can form in vivo under conditions of moderate torsional strain.
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  • 84
    ISSN: 1573-4919
    Keywords: estrogen ; apolipoprotein ; gene expression ; mice ; atherosclerosis
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Estrogen protects against developing premature coronary artery disease.However, the mechanism of protective effects of estrogen still remainspoorly understood. One mechanism by which estrogen can have protectiveeffects apppears to be through modulation of plasma lipoproteins. We showedthat the mouse can be used as animal model to study estrogen-mediatedsynthesis and secretion of lipoproteins since, unlike the rat, the mousedoes not up-regulate LDL receptors (Srivastava et al. [4]). Since inbredstrains of mice differ in their genetic background and show differingresponsiveness to dietary lipids, we examined how various inbred strains ofmice respond to estradiol administration, and whether some mouse strainsshow responses similar to rats. 17b-estradiol was administered to male micefrom 15 different inbred strains, and the changes in plasma levels oflipids, apoB, apoAI, and apoE were examined. Total cholesterol decreased inall but one strain, apoAI levels decreased in all but 3 strains while apoBlevels and apoB/apoAI ratios increased in all but 2 strains, suggesting thatin contrast to rats, the apoB-containing lipoproteins increased relative toHDL in all strains of mice examined. Basal and estradiol-induced changes intotal cholesterol were significantly correlated with changes in apoAI, butnot apoB, reflecting the predominance of HDL over other lipoproteins inmouse plasma. The effects of estrogen on plasma apoE levels varied amongvarious inbred strains of mice tested. Plasma apoE levels increased in sevenstrains treated with estrogen, and remained unchanged in the rest. Toexamine whether changes of plasma apoproteins are associated with thechanges in the respective hepatic mRNA levels, apoAI, B and E mRNA werequantified by RNase protection assay. Hepatic apoE mRNA did not showcorrelation with either basal or post treatment plasma apoE levels in any ofthe strains. Similarly, most of the mouse strains did not show correlationof plasma apoAI and apoB levels with the corresponding hepatic mRNA levels.These results suggest that estrogen regulates plasma lipoproteinconcentrations primarily by posttranscriptional mechansims, and there werestrain-related differences in the estrogen-mediated regulation oflipoprotein metabolism.
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  • 85
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    Keywords: regucalcin ; Ca2+-binding protein ; insulin ; gene expression ; HepG2 cells ; transformed cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The expression of hepatic Ca2+-binding protein regucalcin in the cloned human hepatoma cells (HepG2) was investigated. The change in regucalcin mRNA levels was analyzed by Northern blotting using rat liver regucalcin complementary DNA (0.9 kb of open reading frame). Regucalcin mRNA was expressed in HepG2 cells, although the mRNA was markedly expressed in normal rat liver. Moreover, regucalcin protein in HepG2 cells was detected by Western blot analysis using a polyclonal rabbit anti-regucalcin antibody. Regucalcin mRNA expression in HepG2 cells was clearly stimulated by the culture with insulin (10-8 M) of the effective concentration. Regucalcin protein in HepG2 cells was also increased by the treatment of insulin (10-8 M). The present results demonstrate that regucalcin is expressed in the transformed HepG2 cells, and that the expression is stimulated by insulin.
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  • 86
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    Molecular and cellular biochemistry 177 (1997), S. 1-6 
    ISSN: 1573-4919
    Keywords: gene expression ; mRNA secondary structure ; single tube RT-PCR ; TNF receptor I
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The secondary structure of human tumor necrosis factor receptor I (TNFR-I) mRNA based on its lowest folding energy was predicted. Three combinations of primers selected from open-regions and four combinations of primers from closed-regions of TNFR-I mRNA structure were employed for single-tube reverse transcription-polymerase chain reaction (RT-PCR) for the determination of TNFR-I gene expression in U937 cell. All the primers were designed with the same criteria. However, the different primers generated distinct quantities of RT-PCR products from the same concentration of TNFR-I mRNA, implying that the determination of gene expression by RT-PCR was affected by the mRNA secondary structure. In addition, the sensitivity of the open-region RT-PCR was approximately one hundred-fold higher than that in the closed-regions of TNFR-I mRNA. The low efficiency of the closed-region RT-PCR was not correlated with the G/C content of the TNFR-I mRNA structure. These results suggest that consideration of the influence of intrinsic mRNA structure of a gene is essential prior to the determination of gene expression by quantitative RT-PCR, and this open-region strategy of primer design may yield an efficient primer for in vitro amplification of cDNA by RT-PCR.
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  • 87
    ISSN: 1573-4919
    Keywords: cholesteryl ester ; CETP ; Caco-2 ; polymerase chain reaction ; gene expression ; mRNA ; alternative splicing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Cholesteryl ester transfer protein (CETP) is a plasma protein involved in the reverse cholesterol transport and expressed in several human tissues and cell lines. We studied CETP expression in Caco-2 cell line, a model of the human enterocyte epithelium. By reverse-transcriptase polymerase chain reaction, we could demonstrate that in basal condition Caco-2 cells have a low rate of expression of active CETP mRNA. Furthermore, we found that even in this cell line CETP mRNA alternative splicing occurs with deletion of exon 9 sequence. Densitometric analysis of the in vitro amplified fragments showed that under basal conditions about 60% of reverse transcribed CETP cDNA corresponds to exon 9-deleted transcripts. After challenge with 50 µM sodium oleate, there is a ∼2 fold increase in the transcription rate of the full-length CETP cDNA, as measured by competitive PCR, which is accompanied to an increased activity measured in the cell-conditioned medium. On the contrary, no significant change is seen in the amount of exon 9-deleted cDNA. Consequently, an inversion in the ratio of full-length and exon 9-deleted CETP cDNA is evident, suggesting that sodium oleate selectively enhances the expression of full-length CETP mRNA.
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  • 88
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    Molecular and cellular biochemistry 178 (1998), S. 283-287 
    ISSN: 1573-4919
    Keywords: regucalcin ; calcium-binding protein ; gene expression ; fetal development ; rat liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The expression of hepatic calcium-binding protein regucalcin mRNA in fetal rats was investigated. The alteration in regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin cDNA (0.9 kb with complete open reading frame). Hepatic regucalcin mRNA levels were progressively increased with fetal development; the mRNA was clearly expressed at 15 and 21 days of pregnancy but only slightly at the 8 days. Meanwhile, β-actin mRNA levels in the fetal liver were remarkable at 8 and 15 days of pregnancy. The fetal liver regucalcin mRNA levels at 15 days of pregnancy were significantly decreased by overnight-fasting of maternal rats. The oral administration of calcium chloride (50 mg Ca/100 g body weight) to maternal rats at 15 days of pregnancy caused a remarkable elevation (about 2 fold) of regucalcin mRNA levels in the fetal liver; this increase was seen 60 and 180 min after the calcium administration. After birth, regucalcin mRNA was increasingly expressed in the livers of newborn and weanling rats, while hepatic β-actin mRNA expression was not appreciably altered with increasing ages. These findings demonstrate that the expression of hepatic regucalcin mRNA is increased with fetal development, and that the gene expression may be stimulated by the ingestion of dietary calcium.
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  • 89
    ISSN: 1573-4919
    Keywords: extremely low frequency magnetic fields ; gene expression ; neuron derived orphan receptor-1 ; signal transduction ; Chinese hamster ovary K1 cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Enhanced expression of neuron derived orphan receptor (NOR-1) gene was observed by exposure of Chinese hamster ovary K1 (CHO-K1) cells to an extremely low frequency magnetic field (ELFMF) of 50 Hz at 400 mT, but not at 5 mT. The enhanced expression, reaching the maximum at 6 h, was transient and reduced to the control level after exposure to 400 mT ELFMF for 24 h. The NOR-1 expression induced by treatment with forskolin and TPA was further enhanced by the simultaneous treatment with 400 mT ELFMF, in which the maximum response was at 3 h. The NOR-1 expression by these treatments was induced more earlier than that by 400 mT ELFMF alone. When cells were treated with an inhibitor of the protein kinase C (calphostin C or crocetin) and Ca2+ entry blockers (nifedipin and dantrolen) during the 400 mT ELFMF exposure, the enhanced NOR-1 expression was not observed. Exposure of CHO-K1 cells to the high-density 400 mT ELFMF may affect the signal transduction in the cells, resulting in the enhanced NOR-1 gene expression.
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  • 90
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    Molecular and cellular biochemistry 188 (1998), S. 41-48 
    ISSN: 1573-4919
    Keywords: zinc ; transcription factors ; gene expression ; organogenesis ; Xenopus laevis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Zinc regulates the gene expression machinery. It affects the structure of chromatin, the template function of its DNA, the activity of numerous transcription factors and of RNA polymerases. Hence, it determines both the types of mRNA transcripts synthesized and the rate of transcription itself. Alterations in one or more of these zinc dependent processes have been proposed to account for the proliferative arrest and teratology induced by zinc deficiency. To examine this proposal, studies of zinc during X. laevis development have been initiated. The kinetics of X. laevis oocyte zinc uptake and storage and of zinc utilization during embryogenesis have been examined first. Vitellogenin carries zinc into the oocyte. Ten % of the total zinc (10 ng/egg) remains within the cytosol while 90% (90 ng/egg) is stored in the yolk platelets associated with lipovitellin. The cytosolic pool is the source of the zinc for all newly formed metalloproteins involved in embryo development. The yolk platelet zinc pool is stored for later use during early metamorphosis. It is now possible to examine zinc transfer to molecules, such as e.g. transcription factors, and the role of the metal in their function in development and organogenesis.
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  • 91
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    Molecular and cellular biochemistry 189 (1998), S. 107-111 
    ISSN: 1573-4919
    Keywords: gene expression ; electromagnetic fields ; superinduction ; anisomycin ; immediate early gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Rat pheochromocytoma PC12 cells have been treated with nerve growth factor (NGF) at final concentrations of 2, 4, 8, and 16 ng/ml, and then were exposed to 60-Hz, sinusoidal magnetic fields (MF) of 12.5, 25, 50, and 100 μT (rms) for 30 min. Transcript levels for both c-fos and glyceraldehyde-3 -phosphate dehydrogenase were determined by Northern blot analysis using 32P-labeled cDNA probes. No change in c-fos expression was measured at any condition employed. Treatment of PC12 cells with a combination of agents (NGF, forskolin, and tetradecanoylphorbol acetate [TPA]) increased c-fos expression over that detected with NGF alone. MF exposure of cells treated with the three-agent regimen produced two outcomes, either no change or a doubling of c-fos expression. In subsequent experiments, cells were treated with NGF, NGF + forskolin + TPA, or pre-treated with anisomycin and then treated with NGF + forskolin + TPA. It was determined that MF exposure, like superinduction with anisomycin, increased c-fos expression only in cultures which were not yet exhibiting maximal c-fos expression. It is hypothesized that MF exposure, like anisomycin, may alter the activity of key intracellular protein kinases.
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  • 92
    ISSN: 1573-4919
    Keywords: mechanical stretch ; smooth muscle cells ; differential display ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Physical forces induce profound changes in cell phenotype, shape and behavior. These changes can occur in vascular structures as a result of pressure overload and their effects can be seen in atherosclerotic vessels in which smooth muscle cells have undergone hyperplastic and hypertrophic changes. At the molecular level, mechanical stimuli are converted into chemical ones and lead to modulation of gene expression and/or the activation of a new repertoire of genes whose encoded proteins help the cells to adapt to their microenvironment. In this study, we have used a two primer-based mRNA differential display technique to identify candidate mechano-responsive genes in pulmonary artery smooth muscle cells. As compared to the original method described by Liang and Pardee, this technique uses two arbitrary primers instead of an anchored oligo(dt) plus an arbitrary primer in the polymerase chain reaction. The chief advantages of these modifications are an increase in the efficiency of the amplification and in the identification of differentially expressed clones. Using this approach, we compared the pattern of expressed genes in cells cultured under static conditions with those in cells that were mechanically stretched (1 Hz) for 24 h in a well-defined in vitro mechanical system. Three candidate genes that showed reproducible differences were chosen for further characterization and cloning. One clone was under expressed in stretched cells and had a DNA sequence with 90% homology to the human fibronectin gene. Two other clones were highly expressed in stretched cells and had a 92% and a 83% sequence homology with human platelet-activating factor (PAF) receptor and rat insulin-like growth factor-I (IGF-I) genes respectively. Northern blot analysis confirmed low levels of fibronectin mRNA transcripts in stretched cells. In contrast, accumulation of PAF receptor mRNA occurred 30 min after mechanical stretch was initiated whereas IGF-I mRNA levels peaked at 8 h. Both mRNA levels were sustained for up to 24 h of mechanical stretching. These results demonstrate the usefulness of the two primer-based mRNA differential display that enabled us to identify and characterize alterations at the level of gene expression among matrix proteins, G-protein coupled receptors and growth factors, each of whose response to mechanical strain is different. A more complete understanding of these responses will provide further insight into the pathologic processes associated with hypertension and atherosclerosis.
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  • 93
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    Biochemical genetics 16 (1978), S. 831-853 
    ISSN: 1573-4927
    Keywords: Triticum aestivum L. ; wheat ; storage proteins ; gliadins ; gel electrophoresis ; endosperm ; dominant genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Inheritance of gliadin components unique to three different varieties of common wheat (Triticum aestivum L.) was studied in F1 and F2 seeds of intervarietal crosses using protein patterns obtained by polyacrylamide gel electrophoresis in aluminum lactate buffer (pH 3.2). The patterns of F1 seeds of the crosses Cheyenne × Justin and INIA 66R × Justin evidenced all the bands present in the patterns of the parents; band intensities reflected gene dosage levels dependent on whether the contributing parent was maternal or paternal in accordance with the triploid nature of endosperm tissue. Most of the gliadin components examined segregated in accordance with control by a single dominant gene, but in two instances single bands in the one-dimensional electrophoretic patterns segregated in the F2 as expected if controlled by two genes. A method of two-dimensional electrophoresis was developed that resolved these apparently single bands into two components each, which could segregate independently. Linkage analysis provided evidence of codominant alleles and closely linked genes coding for gliadin protein components in both coupling and repulsion situations. The gliadin protein components seem to be coded for by clusters of genes located on chromosomes of homoeologous groups 1 and 6 in hexaploid wheats.
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  • 94
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    Molecular biology reports 24 (1997), S. 221-230 
    ISSN: 1573-4978
    Keywords: gene expression ; ribonucleoprotein ; RNase MRP ; RNase P ; transcription
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report on the expression of mouse RNase MRP RNA in human embryonic kidney 293 cells upon DNA transfection. Stable cell lines were selected by cotransfection with a neo r gene. Transcription of wild-type and deletion mutants of MRP RNA and ribonucleoprotein formation were assessed by RNase protection and immunoprecipitation experiments. Mouse MRP RNA as expressed in 293 cells readily associates with human proteins to form a chimeric Th ribonucleoprotein. 5' truncated MRP RNAs, however, failed to associate with Th antigen(s) and deletion of the 3' sequences of MRP RNA greatly reduced the expression in stable as well as in transient transfectants. Abbreviations: nt(s) – nucleotide(s); RNP – ribonucleoprotein.
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  • 95
    ISSN: 1573-4978
    Keywords: gene expression ; nuclear matrix proteins ; ocular lens epithelial cells ; transcription factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Association of transcription factors with the nuclear matrix represents a mechanism by which nuclear architecture may influence transcriptional control of gene expression. This investigation examines nuclear matrix associated proteins (NMP's) isolated from ocular lens epithelial cells by monitoring DNA binding activities using consensus oligonucleotides recognized by the transcription factors YY1, AML-1, AP-1, SP-1 and ATF. The nuclear matrix fractions tested included an immortilized human lens epithelial cell line containing the SV40 large T-antigen, and two mouse lens epithelial cell lines derived from either a normal mouse or a cataract mouse. A rabbit epidermal epithelial cell line and HeLa cells were also included in this study for comparison. The data from these experiments reveal that ubiquitously represented and tissue restricted regulatory proteins are associated with nuclear matrix of lens epithelial cells. The functional significance of the nuclear matrix association of these transcription factors remains to be determined. However, our findings raise the possibility that the transcription factors associated with the nuclear matrix could have specific roles in gene regulation and eye tissue development.
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  • 96
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    Molecular biology reports 23 (1996), S. 205-210 
    ISSN: 1573-4978
    Keywords: autoantigen ; cDNA cloning ; gene expression ; ribonucleoprotein Ro ; 5′RACE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Autoantibodies to SS-A/Ro are among the most common found in sera of patients with systemic rheumatic diseases. These autoimmune diseases can affect various organ systems of the body and are variable in their manifestations and presentation. One of the autoimmune targets is the 60 kDa SS-A/Ro protein known to be associated with small cytoplasmic Y RNAs. To study systematically the expression of the protein, we have cloned the mouse full length 60 kDa SS-A/Ro cDNA using 5′ RACE based on a cDNA sequence reported in the mouse genome project. The recombinant protein derived from the putative full-length construct was shown to react with human prototype anti-SS-A/Ro serum Ge in western blot and immunoprecipitation and comigrated with cellular 60 kDa SS-A/Ro protein in 3T3 cells. Cellular expression, measured by RT-PCR, was highest in mouse brain, followed by lung, muscle, kindney and heart. Lower levels were found in testis, liver and spleen. Like the human 60 kDa SS-A/Ro protein, the deduced mouse homolog has 538 amino acids. Sequence analysis showed 89.9% identity and 95.0% similarity between the mouse and human proteins.
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  • 97
    ISSN: 1573-5028
    Keywords: β-fructofuranosidase ; invertase ; gene expression ; gene structure ; flower buds ; Daucus carota
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three genomic clones (Inv *Dc1, Inv *Dc2 and Inv *Dc3) were isolated by using the cDNA for carrot cell wall β-fructofuranosidase as a probe. The expression patterns of the three genes differed markedly. High levels of Inv *Dc1 transcripts were found in leaves and roots of young carrot, whereas in plants with developing tap roots no transcripts were detected. A high level of mRNA of Inv *Dc1 was also present in suspension-cultured cells. In developing reproductive organs, only low levels of transcripts of Inv *Dc1 were found in flower buds and flowers and none at later stages of development. In contrast, Inv *Dc2 and Inv *Dc3 were not expressed in vegetative plant organs. Invb1 *Dc1 was exclusively and strongly expressed in flower buds, and Inv *Dc3 at a very low level in suspension-cultured cells.
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  • 98
    ISSN: 1573-5028
    Keywords: fruit ; gene expression ; promoter ; ripening ; tomato ; transgenic plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The 1.4 kb 5′ polygalacturonase (PG) gene-flanking region has previously been demonstrated to direct ripening-specific chloramphenicol acetyl transferase (CAT) expression in transgenic tomato plants. The steady state level of CAT mRNA in these plants was estimated to be less than 1% of the endogenous PG mRNA. Further constructs containing larger PG gene-flanking regions were generated and tested for their ability to direct higher levels of reporter gene expression. A 4.8 kb 5′-flanking region greatly increased levels of ripening-specific reporter gene activity, while a 1.8 kb 3′ region was only shown to have a positive regulatory role in the presence of the extended 5′ region. Transgenic plants containing the CAT gene flanked by both of these regions showed the same temporal pattern of accumulation of CAT and PG mRNA, and steady-state levels of the transgene mRNA were equivalent to 60% of the endogenous PG mRNA on a per gene basis. The proximal 150 bp of the PG promoter gave no detectable CAT activity. However, the distal 3.4 kb of the 4.8 kb 5′ PG promoter was shown to confer high levels of ripening-specific gene expression when placed in either orientation upstream of the 150 bp minimal promoter. The DNA sequence of the 3.4 kb region revealed a 400 bp imperfect reverse repeat, and sequences which showed similarity to functionally significant sequences from the ripening-related, ethylene-regulated tomato E8 and E4 gene promoters. The possible roles of the flanking regions in regulating PG gene expression are discussed.
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  • 99
    ISSN: 1573-5028
    Keywords: acetohydroxyacid synthase ; gene organization ; gene expression ; herbicide resistance ; cotton ; Gossypium hirsutum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The acetohydroxyacid synthase (AHAS) gene family of the cotton AD allotetraploid Gossypium hirsutum has been cloned and characterized. We have identified six different AHAS genes from an analysis of genomic clones and Southern blots of genomic DNA. Four of the six genes are organized as tandem pairs, in which the genes are separated by only 2–3 kb. Conservation of restriction fragment length polymorphisms between G. hirsutum and A-genome and D-genome-containing diploid cottons was sufficient to assign the single genes in clones A5 and A19 to the A and D subgenomes, respectively. Each diploid genome has one tandem pair, but in these cases we could not make specific subgenomic assignments. DNA and deduced amino acid sequences were determined for the A5 and A19 genes, and an AHAS cDNA clone isolated from a leaflibrary. The sequence of the A19 gene matches that of the cDNA clone, while the A5 gene is 97.8% similar. The four genes comprising the tandem pairs are much less similar to the cDNA clone. The deduced amino acid sequences of the mature polypeptides encoded by the A5 and A19 genes are collinear with the housekeeping forms of AHAS from Arabidopsis thaliana, Nicotiana tabacum and Brassica napus. The constitutive expression of A5 and A19 was confirmed with RNase protection assays and northern blots. We conclude that these genes encode the main house-keeping froms of AHAS in G. hirsutum. Among the four AHAS genes comprising the two tandem pairs, at least two are functional. These genes exhibit either low-level constitutive expression (one or both of the ‘downstream’ genes of each pair), or highly specific expression in reproductive tissue (one or both of the ‘upstream’ genes of each pair). The AHAS gene family of G. hirsutum is more complex than that of other plants so far examined.
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  • 100
    ISSN: 1573-5028
    Keywords: Brassica ; phosphate starvation ; gene expression ; β-glucosidase ; mineral nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Differential gene expression at the transcriptional level was examined as an initial step in the investigation of the Pi starvation response of Brassica nigra suspension cells. Total RNA was extracted from 7-day old cells grown in media containing either no Pi, 1.25 mM or 10 mM Pi., In vitro translation was carried out using their respective poly(A)+ RNA isolates and the resultant polypeptides were separated on a high-resolution SDS-PAGE gel. Scanning densitometry identified four polypeptides (ca. 31.7, 32.3, 52.5 and 64.8 kDa) present only in the Pi-starved samples. Screening by differential hybridization was performed on a cDNA library constructed from mRNA isolated from Pi-starved cells. Probes prepared from mRNA from Pi-deficient and Pi-sufficient cells identified a number of clones representing mRNA species that were preferentially transcribed under Pi deficiency. These phosphate starvation-responsive (psr) clones were placed into eleven groups as determined by cross-hybridization. Northern blots showed that the corresponding genes are inducible in both mild and severe Pi starvation conditions. Preliminary sequencing identified one of the clones as being homologous to β-glucosidases from several plant species. The possible role of β-glucosidase during Pi starvation and the identities of the other psr genes are discussed.
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