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  • Genetics  (3)
  • Organic Chemistry  (3)
  • Wiley-Blackwell  (6)
  • Cambridge University Press
  • Geological Society of America (GSA)
  • Wiley
  • 1990-1994  (6)
  • 1965-1969
  • 1
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 6 (1994), S. 86-90 
    ISSN: 0899-0042
    Schlagwort(e): chirality ; fluoxetine ; norfluoxetine ; desipramine ; iprindole ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The antidepressant fluoxetine (FLU) and its N-demethylated metabolite, norfluoxetine (NFLU), each contains a chiral center. The combination of FLU and desipramine (DMI), another antidepressant, has been reported to be useful in treatment of depression, to dramatically increase plasma levels of DMI and also to produce more rapid β-adrenergic receptor down-regulation in brain than caused by DMI alone. We have now begun studies on the effects of this drug combination on the levels of FLU and NFLU enantiomers in the rat. In addition, the combination of FLU and iprindole (IPR) was also investigated. Male Sprague-Dawley rats were treated intraperitoneally with either normal saline vehicle, DMI (5 mg/kg/day), (R,S)-FLU (10 mg/kg/day) or DMI (5 mg/kg/day) + (R,S)-FLU (10 mg/kg/day) for 4 days. Following the last treatment, 24 h urine samples were collected. Rats were sacrificed and brains were removed. For the IPR study, rats were pretreated with either saline or IPR-HCl (11.2 mg/kg) and then treated 1 h later with (R,S)-FLU. After 5 h, the rats were sacrificed and brains were removed. Brain and urine samples were analyzed by gas chromatography with electron-capture detection for free (R)- and (S)-FLU and (R)- and (S)-NFLU after extraction and reaction with (-)-(S)-N-(trifluoroacetyl)prolyl chloride. The results from the brains of the rats treated with DMI/FLU indicate that levels of the enantiomers of both FLU and NFLU were significantly increased over those seen in the animals receiving (R,S)-FLU alone. In the IPR/FLU treated rats, an increase in the brain levels of both (R)- and (S)-FLU was noted when compared with rats receiving (R,S)-FLU alone; however, there appeared to be no increase in the brain levels of NFLU enantiomers. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 4 (1990), S. 543-549 
    ISSN: 0268-2605
    Schlagwort(e): Borohydride ; iron phosphine ; organoiron ; NMR spectroscopy ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: FeH(DMPE)2(BH4) [DMPE = 1,2-bis(dimethylphosphino)ethane] is a stable, diamagnetic complex which can be synthesized readily by borohydride reduction of FeH(DMPE)2Cl or by treatment of Fe(DMPE)2H2 with borane. The complex contains an unsupported B—H—Fe hydrogen bridge. Analogous complexes with bulkier ligands, FeH(DEPE)2(BH4), [DEPE = 1,2-bis(diethylphosphino)ethane] and FeH(DPrPE)2(BH4) [DPrPE = 1,2-bis(di-n-propylphosphino)ethane], are less stable. In all complexes, in solution the borohydride ligand undergoes rapid internal motion, with all four boron-bound hydrogens interchanging environments. The barriers for BH4 reorientation (measured by NMR spectroscopy) are in the sequence FeH(DMPE)2(BH)4 〉 FeH(DEPE)2(BH)4 〉 FeH(DPrPE)2(BH4).
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 4 (1990), S. 551-556 
    ISSN: 0268-2605
    Schlagwort(e): Metal hydride ; iron phosphine ; organoiron ; NMR spectroscopy ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Syntheses and properties of the iron bisphosphinoethane complexes FeH2(PP)2 and FeHCl(PP)2[PP=R2PCH2CH2CH2PR2, where R=Me (PP=DMPE), Et(PP=DEPE), and n-Pr (PP=DprPE)] are reported. The complexes can be formed by reduction of the corresponding dichlorides FeCl2(PP)2 with lithium aluminium hydride in THF solution provided that ethanol or more acidic reagents are not employed during the reaction work-up. The dihydrides are notably basic compounds and can be protonated reversibly by alcohols.The dihydrides exist as equilibrating mixtures of cis and trans isomers in solution. The cis isomers of each of the dihydrides are fluxional on the NMR timescale and NMR studies indicate that the interconversion of cis isomers does not necessarily proceed via the trans isomer.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 12 (1991), S. 362-370 
    ISSN: 0192-253X
    Schlagwort(e): Aging ; genetics of aging ; biomarkers ; free radicals ; catalase ; Drosophila ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: A long-lived (L) strain of Drosophila melanogaster, derived from a normal-lived (R) strain by artificial selection, has a significantly different adult longevity. Previous work has shown that (1) the two strains age in the same manner, (2) the major genes responsible for much of the L strain's extended longevity are located on the 3rd chromosome, and (3) the extended longevity phenotype is significantly modulated by the larval environment. In this report, we investigate the resistance of the L and R strains to the lethal effects of dietary paraquat. We show that, within the limitations of our described chromosomal and environmental manipulations, the extended longevity phenotype always accompanies the phenotype of elevated paraquat resistance. In addition, reversed selection applied to the L strain results in the simultaneous decrease of both life span and paraquat resistance. Thus, the presence or absence of the latter phenotype may be used as a bioassay for the presence or absence of the extended longevity phenotype, without any necessary implication of causality. Use of this bioassay should greatly speed up the genetic analysis of this system by allowing us to identify long-lived animals at a young age. Finally, we show that the age-related loss of elevated paraquat resistance in both strains precedes all the other age-related functional decrements which we have previously noted in this system.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 15 (1994), S. 275-296 
    ISSN: 0192-253X
    Schlagwort(e): Reproductive behavior ; courtship song ; Sex-specific internal anatomy ; doublesex mutants ; transformer mutants ; intersex mutant ; fruitless mutants ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The function of the central nervous system as it controls sex-specific behaviors in Drosophila has been studied with renewed intensity, in the context of genetic factors that influence the development of sexually differentiated aspects of this insect. Three categories of genetic variations that cause anomalies in courtship and mating behaviors are discussed: (1) mutants isolated with regard to courtship defects, of which putatively courtship-specific variants such as the fruitless mutant are a subset; (2) general behavioral and neurological variants (including sensory and learning mutants), whose defects include subnormal reproductive performance; and (3) mutations of genes within the sex-determination regulatory hierarchy of Drosophila, the analysis of which has included studies of reproductive behavior. Recent studies of mutations in two of these categories have provided new insights into the control of neuronally based aspects of sex-specific behavior. The doublesex gene, the final factor acting in the sex-determination hierarchy, had been previously thought to regulate all aspects of sexual differentiation. Yet, it has been recently shown that doublesex does not control at least one neuronally-determined feature of sex-specific anatomy - a muscle in the male's abdomen, whose normal development is, however, dependent on the action of fruitless. These considerations prompted us to examine further (and in some cases re-examine) the influences exerted by sex-determination hierarchy genes on behavior. Our results - notably those obtained from assessments of doublesex mutations' effects on general reproductive actions and on a particular component of the courtship sequence (male “singing” behavior) - lead to the suggestion that there is a previously unrecognized branch within the sexdetermination hierarchy, which controls the differentiation of the male- and female- specific phenotypes of Drosophila. This new branch separates from the doublesex-related one immediately before the action of that gene (just after fransformer and transformer-2) and appears to control as least some aspects of neuronally determined sexual differentiation of males. © 1994 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 14 (1993), S. 460-470 
    ISSN: 0192-253X
    Schlagwort(e): mRNA stability ; tubulin mRNA ; flagella ; Chlamydomonas ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: In Chlamydomonas rein-hardtii, flagellar amputation stimulates an induction in the synthesis of flagellar proteins which allows the cells to rapidly regenerate their flagella. The induction involves the coordinate accumulation and rapid degradation of a large number mRNAs, including those encoding the tubulins. The post-induction degradation of induced tubulin mRNAs has been shown to differ from the consti-tutive turnover pathway in two ways: (1) the rate of degradation is accelerated, and (2) degradation is prevented by inhibition of protein synthesis. In this report, it is shown that the post-induction degradation of all deflagellation-induced mRNAs examined is prevented by cycloheximide (CX), suggesting they all may be degraded via the same pathway. A cell-free decay system has been developed to investigate the degradation pathway. At least two characteristics of tubulir mRNA degradation are reproducible in these extracts: (1) endogenous α-tubulin mRNA is less stable than constitutive mRNAs in the same extract and (2) α-tubulin mRNA in extracts prepared from CX-treated cells (CX ex-tracts) is significantly more stable than it is in extracts from untreated cells (control extracts). This indicates that the mechanism by which CX blocks rapid degradation of tubulin mRNA in vivo is not simply by preventing its translation and suggests the involvement of an altered trans-factor. The difference in tubulin mRNA stability in the two extracts is maintained when the extracts are prepared under conditions that dissociate ribosomes from mRNPs, indicating intact polysome structure is not necessary. Tubulin mRNA-containing polysomes isolated from control and CX extracts are equally stable when assayed alone. However, the poly-somes from control extracts are more sensitive to exogenous RNAse treatment than are those from CX extracts, indicating a structural difference. There are no detectable differences in soluble factors that influence tubulin mRNA degradation rate between control and CX extracts; addition of excess soluble factors to either control or CX extracts does not alter the tubulin mRNA degradation in the extract, nor does a simple one-to-one combination of the two extracts result in stabilization or destabilization of the whole population of tubulin mRNAs in the mixture. The deflagellation-induced mRNAs, as a group, are shown to be particularly susceptible to a nuclease activity in extracts, inhibitable by vanadyl ribonucleoside complexes, which does not appear to attack constitutive mRNAs. It is proposed that a structural difference in the tubulin mRNPs produced in the presence and absence of CX underlies their differences in stabilities, and that a common nuclease targets the induced flagellar protein mRNAs. © 1993 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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