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  • Analytical Chemistry and Spectroscopy  (3)
  • Glutamine synthetase  (3)
  • Life and Medical Sciences  (3)
  • GENES  (2)
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  • 1
    Keywords: CANCER ; PROTECTION ; MODEL ; DISEASE ; EPIDEMIOLOGY ; HISTORY ; RISK ; GENE ; GENES ; SAMPLE ; FAMILY ; RISK-FACTORS ; SUSCEPTIBILITY ; BREAST ; breast cancer ; BREAST-CANCER ; AGE ; BRCA1 ; case-only design ; family history ; gene carrier probability ; LINKAGE ANALYSIS ; mixture logistic model ; ovarian cancer ; OVARIAN-CANCER ; population and sibling controls ; WOMEN
    Abstract: Background The effect of environmental/lifestyle factors on breast cancer risk may be modified by genetic predisposition. Methods In a population-based case-control-family study performed in Germany including 706 cases by age 50 years, 1381 population, and 252 sister controls, we investigated main effects for environmental/lifestyle factors and genetic susceptibility and gene-environment interaction (G x E). Different surrogate measures for genetic predisposition using pedigree information were used: first-degree family history of breast or ovarian cancer; and gene carrier probability using a genetic model based on rare dominant genes. Possible G x E interaction was studied by (1) logistic regression using cases and population controls including an interaction term; (2) comparing results using sister controls and population controls; (3) case-only analysis with logistic regression and (4) a mixture logistic model. Results Familial predisposition showed the strongest main effect and the estimated gene carrier probability gave the best fit. High parity and longer duration of breastfeeding reduced breast cancer risk significantly, a history of abortions increased risk and age at menarche showed no significant effect. We found significant G x E interaction between parity and genetic susceptibility using different surrogate measures. In women most likely to have a high genetic susceptibility, high parity was less protective. Later age at menarche was protective in women with a positive family history. No evidence for G x E interaction was found for breastfeeding and abortion. Conclusions These findings corroborate results from other studies and provide further evidence that the magnitude of protection from parity is reduced in women most likely to have a genetic risk in spite of the limitations of using surrogate genetic measures
    Type of Publication: Journal article published
    PubMed ID: 12690006
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  • 2
    Keywords: CELLS ; EXPRESSION ; proliferation ; SURVIVAL ; tumor ; BLOOD ; CELL ; Germany ; IN-VIVO ; KINASE ; THERAPY ; VIVO ; FOLLOW-UP ; SITE ; SITES ; GENE ; GENE-EXPRESSION ; GENES ; PROTEIN ; PROTEINS ; transcription ; METABOLISM ; TRANSDUCTION ; gene transfer ; GENE-TRANSFER ; PATIENT ; DONOR ; TRANSPLANTATION ; CONTRAST ; SUFFICIENT ; treatment ; FREQUENCY ; FREQUENCIES ; TARGET ; CELL-SURVIVAL ; PATTERNS ; gene expression ; VECTOR ; LYMPHOCYTES ; HUMAN GENOME ; REGION ; REGIONS ; PROGENITOR CELLS ; IMMUNITY ; T-LYMPHOCYTES ; T lymphocyte ; CHILDREN ; PERIPHERAL-BLOOD ; T lymphocytes ; INTEGRATION ; PATTERN ; SEVERE COMBINED IMMUNODEFICIENCY ; LEVEL ; LONG ; progenitor ; EVENTS ; USA ; in vivo ; progenitor cell ; TRANSDUCED CELLS ; RECONSTITUTION ; RETROVIRAL GENE MARKING ; RETROVIRAL INTEGRATION ; MEDICINE ; VECTOR INTEGRATION ; PROGENITOR-CELL ; SCID-X1 ; ADA
    Abstract: We treated 10 children with X-linked SCID (SCID-X1) using gammaretrovirus-mediated gene transfer. Those with sufficient follow-up were found to have recovered substantial immunity in the absence of any serious adverse events up to 5 years after treatment. To determine the influence of vector integration on lymphoid reconstitution, we compared retroviral integration sites (RISs) from peripheral blood CD3(+) T lymphocytes of 5 patients taken between 9 and 30 months after transplantation with transduced CD34(+) progenitor cells derived from 1 further patient and I healthy donor. Integration occurred preferentially in gene regions on either side of transcription start sites, was clustered, and correlated with the expression level in CD34(+) progenitors during transduction. In contrast to those in CD34(+) cells, RISs recovered from engrafted CD3(+)T cells were significantly overrepresented within or near genes encoding proteins with kinase or transferase activity or involved in phosphorus metabolism. Although gross patterns of gene expression were unchanged in transduced cells, the divergence of RIS target frequency between transduced progenitor cells and post-thymic T lymphocytes indicates that vector integration influences cell survival, engraftment, or proliferation
    Type of Publication: Journal article published
    PubMed ID: 17671654
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  • 3
    ISSN: 1432-2048
    Keywords: Ammonium assimilation ; Glutamine synthetase ; Nitrate ; Phytochrome ; Sinapis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During transformation of mustard seedlings cotyledons from storage organs to photosynthetically competent leaves, a process which occurs during the first 4 d after sowing, total glutamine-synthetase (GS, EC 6.3.1.2) activity increases from zero to the high level usually observed in green leaves. In the present study we have used ion-exchange chromatography to separate possible isoforms of GS during the development of the cotyledons. The approach failed since we could only detect a single form of GS, presumably plastidic GS, under all circumstances tested. The technique of selective photooxidative destruction of plastids in situ was applied to solve the problem of GS localization. It was inferred from the data that the GS as detected by ion-exchange chromatography is plastidic GS. The regulatory role, if any, of light, nitrate and ammonium in the process of the appearance of GS in the developing cotyledons was investigated. The results show that nitrate and ammonium play only minor roles. Light, operating via phytochrome, is the major regulatory factor.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-2048
    Keywords: Glutamine synthetase ; Nitrate (as inductor) ; Nitrite reductase ; Phytochrome (as inductor) ; Sinapis (nitrate assimilation)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The extent to which the appearances of nitrite reductase (NIR; EC 1.7.7.1) and glutamine synthetase (GS; EC 6.3.1.2) are coordinated was studied in mustard (Sinapis alba L.) seedlings. It was established by immunotitration that the increased activities of NIR and GS in the presence of light and nitrate can be attributed to the de-novo synthesis of enzyme protein. The bulk of the NIR and GS was found in the developing cotyledons. In the absence of nitrate in the growth medium there was no coordinate appearance of NIR and GS. While light strongly stimulated the appearance of GS, the level of NIR was hardly affected and remained low. On the other hand, in the presence of nitrate in the medium the appearances of NIR and GS were strictly coordinated, the GS level being considerably above that of NIR. It is argued that phytochrome-controlled synthesis of GS in the absence of nitrate is part of the mechanism to reassimilate ammonium liberated during proteolysis of storage protein and metabolism of the resulting amino acids, whereas the strictly coordinated synthesis in the presence of light and nitrate indicates the dominance of nitrate assimilation under these circumstances. The fact that the level of GS was always considerably above that of NIR appears to be a safety measure to prevent ammonium accumulation.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-2048
    Keywords: Glutamine synthetase ; Nitrate (as inductor) ; Nitrite reductase ; Phytochrome (as inductor) ; Sinapis (nitrate assimilation)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The extent to which the appearances of nitrite reductase (NIR; EC 1.7.7.1) and glutamine synthetase (GS; EC 6.3.1.2) are coordinated was studied in mustard (Sinapis alba L.) seedlings. It was established by immunotitration that the increased activities of NIR and GS in the presence of light and nitrate can be attributed to the de-novo synthesis of enzyme protein. The bulk of the NIR and GS was found in the developing cotyledons. In the absence of nitrate in the growth medium there was no coordinate appearance of NIR and GS. While light strongly stimulated the appearance of GS, the level of NIR was hardly affected and remained low. On the other hand, in the presence of nitrate in the medium the appearances of NIR and GS were strictly coordinated, the GS level being considerably above that of NIR. It is argued that phytochrome-controlled synthesis of GS in the absence of nitrate is part of the mechanism to reassimilate ammonium liberated during proteolysis of storage protein and metabolism of the resulting amino acids, whereas the strictly coordinated synthesis in the presence of light and nitrate indicates the dominance of nitrate assimilation under these circumstances. The fact that the level of GS was always considerably above that of NIR appears to be a safety measure to prevent ammonium accumulation.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0935-6304
    Keywords: Gas chromatography, GC ; Glass and fused silica capillary columns ; Coating time and efficiency ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0935-6304
    Keywords: Gas chromatography-mass spectrometry ; Capillary columns ; Stationary phases ; Silicones ; Thermal degradation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The applicability of capillary columns for gas chromatography is often limited by stationary phase degradation at elevated temperatures. In order to achieve a better understanding of column thermostability, column bleed products have been analyzed qualitatively by gas chromatography-mass spectrometry (GC-MS). Three silicone stationary phases were studied: SE-52, SE-54, and OV-1701. Each of these was immobilized in the columns. The proportion of cyclics containing diphenyl in column bleed from SE-52 reflected to a large extent the composition of the polymer, while for SE-54 the proportion of such cyclics was unexpectedly high. The polar moiety of OV-1701, the cyanopropyl(phenyl)siloxy unit, was found to exert a highly destabilizing effect on the polymer, and the thermal degradation products consisted mainly of cyclosiloxanes containing this unit.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0935-6304
    Keywords: Open tubular gas chromatography ; Dynamic headspace analysis ; Purge and trap ; Thermal desorption ; Reinjection ; Fourier transform infrared spectroscopy ; Volatile constituents in polymers ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An analytical system for the analysis of volatiles entrained in polymers is described. This system is based on a thermal desorption oven connected to a cold trap. After enrichment of headspace vapor, trapped material is reinjected and analyzed by open tubular gas chromatography/Fourier transform infrared spectroscopy, OTGC/FTIR. The thermal desorption oven is designed to provide different modes of sample introduction: use of a pyroprobe; insertion of a piece of quartz tubing with applied sample; or syringe injection. Headspace enrichment is carried out in a piece of fused silica capillary tubing filled with glass beads. The trap may be cooled either electrically using Peltier elements or with liquid nitrogen. A six-port rotary valve is used for flow switching between enrichment and reinjection modes. All system parameters, temperatures, and timed events, are controlled from the gas chromatograph. Dynamic headspace analysis is demonstrated as a method for polymer characterization.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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