Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0738
    Keywords: Neuropathy ; Organophosphorus ; Trichlorphon ; Neurotoxic Esterase ; Screening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Progressive neuropathy developed in a man during 2–8 weeks after acute poisoning by a pesticide said to contain trichlorphon. The neuropathy was typical of that caused by organophosphorus esters in the delay and in the maintenance of normal conduction velocity in surviving nerve fibres. A sample alleged to be typical of the ingested material was not more active against hen brain neurotoxic esterase (NTE) than was pure trichlorphon. Delayed neuropathy has never been produced in hens by a single dose of trichlorphon. This incident and studies of human brain in vitro suggest that the ratio neurotoxicity/lethality for trichlorphon is higher in man than in the hen. Suggestion is made of laboratory tests to improve neurotoxicity screening.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0738
    Keywords: Methamidophos ; Pesticide ; Phosphoramidates ; Organophosphorus ; Neuropathy target esterase (NTE) ; Delayed neuropathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The interaction with neural neuropathy target esterase (NTE) and acetylcholinesterase (AChE) in vivo of methamidophos (O,S-dimethyl phosphorothioamidate), its resolved stereoisomers and five higher O-alkyl homologues has been examined along with the ability of these compounds to cause organophosphorus-induced delayed polyneuropathy (OPIDP) in adult hens. For the lower homologues AChE was more sensitive than NTE and it was impossible to achieve high inhibition of NTE in vivo without both prophylaxis and therapy against acute anticholinesterase effects; for then-hexyl homologue high inhibition of NTE could be achieved without obvious anticholinesterase effects and spontaneous reactivation of inhibited AChE was seen as in vitro. The maximum tolerated dose ofl(−) methamidophos or of the ethyl oriso-propyl homologues did not inhibit NTE more than 60%, and surviving birds did not develop OPIDP. Then-propyl,n-butyl andn-hexyl compounds caused typical OPIDP at doses causing a peak of 70–95% inhibition of NTE in brain, spinal cord and sciatic nerve soon after dosing. Racemic methamidophos caused unusually mild OPIDP associated with very high inhibition of NTE at doses estimated to be 〉8 times the unprotected LD50 and thed-(+) isomer caused OPIDP at about 5−7× LD50. Clinical effects correlated with histopathology in 19 out of 20 examined birds. In contrast to results of many previous studies with organophosphates and phosphonates, all these cases of OPIDP were associated with formation of inhibited NTE which could be reactivated ex vivo by treatment of autopsy tissue with KF solution. It is not clear whether “aging” of inhibited NTE had occurred but with less associated stabilisation of the enzyme-phosphorus bond or whether, even without aging, the unusual N-unsubstituted phosphoramidate caused sufficient disturbance in or near the NTE target to initiate the same degenerative process as that caused typically by generation of “aged” organophosphorylated NTE.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 41 (1978), S. 107-110 
    ISSN: 1432-0738
    Keywords: Delayed neurotoxicity ; Dimethyl phosphates ; Neurotoxicity testing anomaly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Several dimethyl phosphate behave anomalously in tests for delayed neurotoxicity. Doses given to hens caused high inhibition of brain neurotoxic esterase (NTE) but no ataxia. Less inhibition of NTE was seen in spinal cord than in brain. Di-isopropyl phosphorofluoridate caused equal inhibition of NTE in brain and cord. When dosing with dimethyl phosphates was repeated NTE inhibition in cord increased and pair-dosed birds became ataxic. In vitro brain and cord NTE were indistinguishable but the in vivo discrepancy between inhibition of brain and cord NTE was matched by a similar discrepancy in inhibition of AChE. It appears that ataxia arises from inhibition of spinal cord NTE and that only in the present cases (among about 200) was the effect in brain not a perfect biochemical monitor.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 196 (1962), S. 1210-1211 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] 100 per cent recovery of activity is necessary in meaningful distribution studies and is usually, though not necessarily, achieved most easily when each fraction sample is made to show the maximum activity of which it is capable with the chosen assay system. For fractions obtained from brain ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Psychology 38 (1987), S. 631-668 
    ISSN: 0066-4308
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Psychology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 23 (1974), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: —In contrast with neurotoxic organophosphates of the type (RO)2P.O.X several phosphinates (R2P.O.X) cause prolonged inhibition of ‘neurotoxic esterase’in vivo but do not cause delayed neurotoxicity even after repeated administration. Prior administration of these phosphinates protected hens against the neurotoxic effects of several organophosphates: this protection lasted until about 70 per cent of the enzyme site again became available for phosphorylation. In this respect phosphinates behave like carbamate and sulphonyl fluoride inhibitors of ‘neurotoxic esterase'. It is proposed that the development of delayed neurotoxicity requires phosphorylation of the esterase followed by hydrolysis of one remaining phosphoryl ester bond to produce a charged monosubstituted phosphoric acid group attached to the protein. Generation of such a group could not occur after inhibition by the protective phosphinates, carbamates or sulphonates. It is proposed that the charged group is responsible for the metabolic disturbance leading to degeneration of long axons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 32 (1979), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Neurotoxic esterase (NTE) is now regarded as the site of the primary biochemical lesion in the delayed neuronal degeneration produced by certain organophosphorus esters. Since hens are the species of choice in studies of this neuropathy the subcellular distribution of NTE and marker enzymes in adult hen brain was carried out. Up to 70%, of NTE was recovered in a microsomal fraction (P3) which was also enriched in 5′-nucleotidase (5′-ribonucleotide phosphohydrolase EC 3.1.3.5), a plasma membrane marker. The protein content of this fraction (31% of the parent homogenate) is double that of equivalent mammalian brain fractions. The LDH distribution suggests that the P3 fraction contained many small synaptosomes. Subfractionation of microsomes by rate and equilibrium centrifugation on sucrose density gradients segregated the RNA but failed to separate the NTE. 5′-nucleotidase and glucose-6-phosphatase (D-glucose-6-phosphate phosphohydrolase EC 3.1.3.9) from each other. NTE was considerably concentrated (2–5 times) in subfractions of the P2 fraction, which are believed to be enriched in synaptosomal membranes. A similar localization of NTE and AChE was found in subfractions of P2 from neonatal chick brain. Axon fragments contained a significant amount of NTE which was not associated with the myelin. Nuclear and mitochondrial fractions were low in NTE. Microsomes could be partitioned in biphasic aqueous polymer systems, but with little enrichment of NTE. The possible association of NTE with synaptosomal membranes suggests that early events in organophosphorus neuropathy may occur at the axonal (? synaptic) surface.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 160 (1969), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...