Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Life and Medical Sciences  (28)
  • Basidiomycete  (5)
  • Dopamine  (5)
  • Lignin model compounds  (5)
  • ALCOHOL  (3)
  • 11
    Electronic Resource
    Electronic Resource
    Metabolism of the lignin model compounds veratrylglycerol-β-guaiacyl ether and 4-ethoxy-3-methoxyphenylglycerol-β-guaiacyl ether by Phanerochaete chrysosporium (1980)
    Springer
    Archives of microbiology 125 (1980), S. 227-231 
    Details
    ISSN: 1432-072X
    Keywords: Phanerochaete chrysosporium ; Lignin model compounds ; β-aryl ether dimers ; Metabolism αβ cleavage ; Veratryl alcohol ; 4-ethoxy-3-methoxybenzyl alcohol ; Alkyl-phenyl cleavage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The white rot fungus Phanerochaete chrysosporium metabolized the lignin model compounds veratylglycerol-β-guaiacyl ether I and 4-ethoxy-3-methoxy-phenylglycerol-β-guaiacyl ether V in stationary culture under an atmosphere of 100% oxygen and under nitrogen limiting conditions. 2-(o-methoxyphenoxy)-ethanol VII was identified as a product of the metabolism of both substrates. Veratryl alcohol and 4-ethoxy-3-methoxybenzyl alcohol IV were identified as metabolites of I and V respectively. Metabolites were identified after comparison with chemically synthesized standards by mass spectrometry. These results indicate the existence of an enzyme system capable of directly cleaving the etherated dimers I and V at the α, β bond. The additional identification of 2-(o-methoxyphenoxy)-1,3 propanediol IX as a metabolic product indicates that cleavage of the alkyl-phenyl bond of these dimers or their metabolites also occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446881
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Degradation of the diarylpropane lignin model compound 1-(3′,4′-diethoxyphenyl)-1,3-dihydroxy-2-(4′'-methoxyphenyl)-propane and derivatives by the basidiomycete Phanerochaete chrysosporium (1982)
    Springer
    Archives of microbiology 132 (1982), S. 123-130 
    Details
    ISSN: 1432-072X
    Keywords: Phanerochaete chrysosporium ; Lignin model compounds ; Lignin degradation ; Diarylpropane ; α,β cleavage ; Anisyl alcohol ; Lignin ; Basidiomycete
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The white rot basidiomycete Phanerochaete chrysosporium metabolized 1-(3′,4′-diethoxyphenyl)-1,3(dihydroxy)-2-(4′'-methoxyphenyl)-propane (XII) in low nitrogen stationary cultures, conditions under which the ligninolytic enzyme system is expressed. 3,4-Diethoxybenzyl alcohol (IV), 1,2(dihydroxy)-1-(4′-methoxyphenyl)ethane (XX) and anisyl alcohol were isolated as metabolic products indicating an initial α, β bond cleavage of this dimer. Exogenously added XX was rapidly converted to anisyl alcohol, indicating that XX is an intermediate in the metabolism of XII. Fungal cleavage of the α, β bond of 1-(3′-4′-diethoxyphenyl)-1-(hydroxy)-2-(4′'-methoxyphenyl)ethane (XI) also occurred, indicating that a γ hydroxymethyl group is not a prerequisite for this reaction. P. chrysosporium also metabolized 1-(4′-ethoxy-3′-methoxyphenyl)-2,2(dihydroxy)-2-(4′'-methoxyphenyl)propane-1-ol (XIII). The major products of the degradation of this triol included 4-ethoxy-3-methoxybenzyl alcohol (III) and 2-hydroxy-1-(4′-methoxyphenyl)-1-oxoethane (XXI). The nature of the products formed indicates that this triol is also cleaved directly at the α,β bond. The significant difference in the nature of the products formed from the diaryl propane (XII) and the triol (XIII), however, suggests that XIII is not an intermediate in the major pathway for the degradation of XII. Metabolites were identified after comparison with chemically synthesized standards by GLC-mass spectrometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508716
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Effects of dopamine and serotonin-releasing agents on methamphetamine discrimination and self-administration in rats (1999)
    Springer
    Psychopharmacology 141 (1999), S. 287-296 
    Details
    ISSN: 1432-2072
    Keywords: Key words Methamphetamine ; Dopamine ; Serotonin ; Phentermine ; Fenfluramine ; Drug-discrimination ; Self-administration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  To analyze the involvement of dopamine (DA) and serotonin (5-HT) release in the stimulus properties of methamphetamine, two amphetamine analogs that selectively release either brain DA (phentermine) or 5-HT (fenfluramine) were tested for their ability to substitute for methamphetamine in rats discriminating methamphetamine (1.0 mg/kg) from saline. They were subsequently tested for their ability to alter IV methamphetamine (0.06 mg/kg per injection) self-administration in the same species when given as a pretreatment. The DA releaser phentermine, like methamphetamine itself, decreased methamphetamine self-administration (to 70% of baseline responding), but only at a dose of 3.0 mg/kg that fully generalized to the methamphetamine stimulus in the discrimination study. The 5-HT releaser fenfluramine attenuated methamphetamine self-administration to a much larger extent than phentermine (to 37% of baseline responding) at a dose of 1.8 mg/kg that did not generalize to methamphetamine and did not decrease rate of responding in the discrimination study. Tolerance developed to the inhibitory effect of 1.8 mg/kg fenfluramine on methamphetamine self-administration when it was given repeatedly over four consecutive daily sessions. The fenfluramine-induced decrease in methamphetamine self-administration was also attenuated when it was given together with the small 1.0 mg/kg dose of phentermine. These results suggest that DA release plays a dominant role in the discriminative stimulus effects of methamphetamine. However, stimulation of 5-HT release can strongly modify methamphetamine self-administration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002130050836
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Behavioural and neurochemical characteristics of phentermine and fenfluramine administered separately and as a mixture in rats (1997)
    Springer
    Psychopharmacology 131 (1997), S. 296-306 
    Details
    ISSN: 1432-2072
    Keywords: Key words Drug discrimination ; Microdialysis ; Dopamine ; Serotonin ; Phentermine ; Fenfluramine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Clinical case studies suggest that combined administration of the serotonergic agent fenfluramine (FEN) and the weak amphetamine-like anorexic agent phentermine (PHEN) may be useful in the treatment of alcohol and cocaine addictions. The present experiment examined the nature of the interaction between the two agonists using the drug discrimination paradigm. In vivo microdialysis served to examine the neurochemical profile of dopamine and serotonin release in the nucleus accumbens. In conscious rats, acute injections of FEN (1.0–2.0 mg/kg IP) or PHEN (1.0–2.0 mg/kg IP) selectively elevated levels of serotonin and dopamine in the nucleus accumbens, respectively. A mixture (1 mg/kg of each) increased levels of both amines by similar magnitudes to those observed with each individually. Three groups of Sprague-Dawley rats were trained to discriminate (1) FEN (1.0 mg/kg IP) alone, (2) PHEN (1.0 mg/kg IP) alone or a mixture (3) PHEN+FEN (1 mg/kg of each, IP) from saline under a fixed ratio (FR-10) schedule of food reinforcement. Rats acquired the mixture discrimination rapidly, while for the other groups the training dose had to be increased to 2.0 mg/kg to attain stimulus control. The individual components of the mixture at the training dose generalized partially to the mixture, and complete generalisation was observed following 3.0 mg/kg FEN or PHEN. Rats trained to discriminate the individual components showed respective cross-generalisation profiles. Generalisation to cocaine (0.3–10.0 mg/kg IP), amphetamine (0.1–3.0 mg/kg IP) and nicotine (0.1–0.8 mg/kg SC) was greatest in the MIX-trained rats, while partial or no generalisation was observed in rats trained to discriminate the individual compounds. From the present results, it may be concluded that the two drugs given as a mixture do not produce a novel cue. Rather, these aminergics appear to interact additively. Furthermore, the dual stimulation of the amines by the mixture may be the basis for the cueing effects of the FEN+PHEN drug mixture, and its effectiveness in treating drug addictions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002130050296
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Coagulation Protein Function V (Diminution of Antithrombin III Function by Acetaldehyde) (1998)
    Springer
    Digestive diseases and sciences 43 (1998), S. 1746-1751 
    Details
    ISSN: 1573-2568
    Keywords: ANTITHROMBIN III ; THROMBIN ; ACETALDEHYDE ; ALCOHOL ; ALCOHOLISM ; BLOOD COAGULATION
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The anticoagulant activity of antithrombin III(ATIII), as observed in a plasma-free system consistingof thrombin and fibrinogen, is readily reduced byacetaldehyde (AcH) at concentrations of 447, 89.4, and 17.9 mM. Whereas controlthrombin-fibrinogen mixtures clotted in 17.7 ±0.75 sec, ATIII prolonged clotting time to 55.0 ±1.75 sec on preincubation with thrombin for 30 min atroom temperature. On subsequent preincubation of ATIII with theAcH for 30 min at room temperature and passage of themixture through Sephadex G-25 minicolumns to removeexcess AcH, the eluates were tested for anticoagulant activity. Clotting times of 20.9 ± 1.0,32.3 ± 1.0, and 45.3 ± 1.6 sec wereobtained with 447, 89.4, and 17.9 mM AcH-ATIII mixtures,respectively. These data suggest that functional groupson ATIII, such as guanidiniums, aminos, and others aresusceptible to adduct formation with AcH, therebyaltering the shape and charge of the anticoagulant. Asa consequence of this type of reaction, an alteredmolecule of reduced biological activity may be produced.These experimental results may explain, in part, thereduction in ATIII levels reported by others in patientswith alcoholic liver disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018831619359
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Coagulation Protein Function VI (Augmentation of Anticoagulant Function by Acetaldehyde-Treated Heparin) (1999)
    Springer
    Digestive diseases and sciences 44 (1999), S. 1349-1355 
    Details
    ISSN: 1573-2568
    Keywords: ANTITHROMBIN III ; THROMBIN ; HEPARIN ; BLOOD COAGULATION ; ACETALDEHYDE ; ALCOHOL ; ALCOHOLISM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Acetaldehyde (AcH) at preincubationconcentrations of 447, 89.4, and 17.9 mM potentiates theeffects of heparin on the clotting time of plasma. Whilecontrol plasma clotted in the range of 12.6 ± 0.1 to 13.8 ± 0.1 sec, and heparin-treatedplasma clotted in a range from 131.5 ± 2.5 to168.2 ± 1.2 sec, heparin that was preincubated atroom temperature for 30 min with 89.4 or 447 mM AcH didnot clot plasma in 300 sec. Heparin exposed to 17.9 mMAcH clotted plasma in 193 ± 1.1 sec. Ethanol ata 404 mM concentration also prolonged the clotting timeof heparin-treated plasma 〉300 sec, while 202 mM ethanol prolonged the clotting time ofheparin-treated plasma from 149.0 ± 2.0 sec to219.5 ± 1.7 sec. It is suggested that AcH altersthe tertiary structure of heparin by adduct formation,possibly by formation of cyclic acetals with iduronicand glucuronic acids, thereby more readily affectingbinding of the glycosaminoglycan to antithrombin IIIand/or thrombin, prolonging clotting time. Ethanol, which does not react covalently with heparin,might affect its conformation as a consequence of anorganic solvent effect. Protamine sulfate prolonged theclotting time of plasma from 13.6 ± 0.1 sec to 17.9 ± 0.2 sec. Protaminesulfate-treated heparin clotted plasma in 21.0 ±0.4 sec relative to heparin-treated plasma (160.4± 1.7 sec). In subsequent experiments,AcH-treated protamine sulfate extended the clotting time of protamine sulfate from17.9 ± 0 sec to 33.7 ± 0.6 sec. Prioraddition of protamine sulfate to AcH- heparin mixturesor heparin to protamine sulfate-AcH mixtures beforeaddition to plasma resulted in clotting times of 22.0± 0.4 sec and 24.1 ± 0.5 sec,respectively, relative to control clotting times of162.3 ± 2.6 sec for plasma-heparin mixtures.These results confirm both the reduction in coagulation time ofheparin-treated plasma by protamine sulfate and theprolongation of clotting time of plasma by protaminesulfate. Furthermore, and importantly, they indicatethat acetaldehyde-treated protamine sulfate is a more effectiveanticoagulant than protamine sulfate. It is suggestedthat reversible adduct formation between acetaldehyde,heparin, and protamine sulfate may occur as a meansexplaining the essentially identical coagulation time ofthese mixtures when added to plasma regardless of theorder of premixing. Ethanol (404 mM) did not influenceprotamine sulfate effects. Lastly, the potentiation of the anticoagulant function of heparin byacetaldehyde suggests that a structural modification ofthe glycosaminoglycan may occur in alcoholics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026635331519
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Coagulation Protein Function VII (Diametric Effects of Acetaldehyde on Factor VII and Factor IX Function) (1999)
    Springer
    Digestive diseases and sciences 44 (1999), S. 2564-2567 
    Details
    ISSN: 1573-2568
    Keywords: ALCOHOL ; COAGULATION ; FACTOR VII ; FACTOR IX ; ACETALDEHYDE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The first metabolite of ethanol, acetaldehyde,has the ability to form adducts with proteins and altertheir function. It has been shown that acetaldehydereacts with various proteins of the blood coagulation pathway and, subsequently, produces aprolongation of the clotting time. This study evaluatedthe function of clotting proteins from the extrinsiccoagulation pathway (factor VII) and the intrinsiccoagulation pathway (factor IX) when preincubated withacetaldehyde as compared to a control and compared topreincubation with ethanol. Prior to use in a clottingassay, incubation times with acetaldehyde, ethanol, and the control were the same for both factorsVII and IX. An automatic fibrometer measured theclotting times. Factor VII preincubated withacetaldehyde prolonged the clotting time. However,factor IX preincubated with acetaldehyde actuallydecreased the clotting time. Of interest, both factorsVII and IX preincubated with acetaldehyde producedstatistically significant results when compared to thecontrol and ethanol. This experiment indicates thatacetaldehyde, in forming an adduct with proteins of theblood coagulation pathway, may induce a conformationalchange of factors VII and IX so as to either increase or decrease the clotting time. Therefore, it ispossible that some of the deranged coagulation inalcohol abusers may be a final net result of theinteraction of acetaldehyde and proteins of thecoagulation pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026615928562
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Analysis of the morphology and function of primary cilia in connective tissues:A cellular cybernetic probe? (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 175-193 
    Details
    ISSN: 0886-1544
    Keywords: primary cilia ; connective tissues ; secretory organelles ; extracellular matrix ; cybernetic probe ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: More than 300 primary cilia have been identified electronmicroscopically in a variety of embryonic and mature connective tissue cells. To further define the enigmatic function of these cilia, we examined the interrelationships between the basal apparatus and cytoplasmic organelles and the ciliary shaft and the extracellular matrix. The basal diplosome was consistently associated with the secretory organelles including the maturing face of the Golgi complex, Golgi vacuoles and vesicles, the microtubular network, the plasma membrane, and coated pits and vesicles. Small vesicles and amorphous granules were also observed within the ciliary lumen and adjacent to the ciliary membrane. Microtubule-membrane bridges linked axonemal tubules to the ciliary membrane. The position, projection, and orientation of the axoneme were influenced by the structural organisation and mechanical properties of the matrix and frequently caused angulation of the ciliary shaft relative to the basal body. Located midway between the secretory apparatus and the extracellular matrix, primary cilia would appear ideally situated to mediate the necessry interaction between the cell and its surrounding environment prerequisite to the formation and maintenance of a functionally effective matrix. We propose that primary cilia in connective tissue cells could act as multifunctional, cellular cybernetic probes, receiving, transducing, and conducting a variety of extrinsic stimuli to the intracellular organelles responsible for effecting the appropriate homeostatic feedback response to changes in the extracellular microenvironment.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970050302
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Second messenger function of phosphatidic acid in platelet activation (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 139 (1989), S. 558-564 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Phosphatidic acid (PA) is synthesized as the result of the receptor-mediated response of platelets to physiologic agonists. The role of PA in platelet signal transduction, however, is largely unknown. We have examined the responses of platelets to 1-stearoyl-2-arachidonoyl phosphatidic acid (SAPA), the predominant molecular species of human platelet PA. SAPA alone causes platelet aggregation, and pretreatment of platelets with SAPA markedly enhances thrombin-induced aggregation and secretion. Addition of SAPA to intact human platelets causes rapid breakdown of phosphatidylinositol-4,5-bisphosphate (PIP2) and the generation of diacylglycerol and endogenous PA. These reactions are associated with mobilization of intracellular calcium and activation of protein kinase C. SAPA also stimulates the release of endogenous arachidonic acid and its conversion to thromboxane A2. Furthermore, platelet activation by SAPA is blocked by indomethacin, indicating that the actions of SAPA are mediated by cyclooxygenase products. These findings suggest that SAPA may play an important role as an endogenous positive feedback signal to amplify receptor-mediated activation of PIP2-specific phospholipase C in human platelets.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041390315
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Increasing and decreasing protein stability: Effects of revertant substitutions on the thermal denaturation of phage λ repressor (1985)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 29 (1985), S. 217-224 
    Details
    ISSN: 0730-2312
    Keywords: mutant repressors ; differential scanning calorimetry ; protein stability ; thermal denaturation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The thermal denaturations of five revertant λ repressors containing single amino acid substitutions in their N-terminal domains have been studied by differential scanning calorimetry. Two substitutions slightly decrease stability, and the remaining three render the protein more stable than wild type. The Gly48 → Asn and Gly48 → Ser proteins are 4°C more stable than wild type. These two substitutions replace an α helical residue, and in each case a poor helix forming residue, glycine, is replaced by a residue with a higher helical propensity. We also present data showing that one revertant, Tyr22 → Phe, has reduced operator DNA binding affinity despite its enhanced stability.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240290306
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...