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The authors have shown an heterogeneity of the ovine prolactine molecule after labelling with iodine 125. As well with chloramine T as with lactoperoxydase, it appears three molecular species which react with the immune serum antiprolactine (I.S.). The first species is of high molecular weight and is probably constituted of aggregates. Their combination with the I.S. is non specific and give blanks of high value. The second species is a dimere and the third one is the monomere. The two last species react with the I.S. and can give competition curves when they are choosen as tracer. However, if one uses as tracer a product obtained by labelling with chloramine T, the competition appears for high concentrations of native hormone. As if the I.S. recognizes much more the labelled protein than the native one. But if one uses the same species but labelled with lactoperoxydase, the competition appears for concentrations lower than five nanogrammes. In the same time one can see that the specificity toward different I.S. is modified. The authors think that the labelling with lactoperoxydase better preserves the tertiary structure of the native protein than do the labelling with chloramine T.  相似文献   
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Effects of Δ8- and Δ9-tetrahydrocannabinol (Δ8- and Δ9-THC) on three experimentally induced seizure models, i.e., audiogenic seizure (AS) test, maximal electroshock seizure (MES) test and pentylenetetrazol (PTZ)-induced seizure test were determined in the audiogenic rat. Both tetrahydrocannabinols possess a dose-related anticonvulsant effect against AS, MES and PTZ-induced maximal seizure. Although anticonvulsant potencies do not significantly differ, Δ8THC is three times more neurotoxic than Δ9THC. In addition, both THC's are without effect on minimal seizure and lethality induced by PTZ. Furthermore, the low protective indexes (TD50/ED50) determined in this study suggest that Δ8 and Δ9 THC may have poor therapeutic potentials as antiepileptic drugs.  相似文献   
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Effect of Selected Herbicides on Bacterial Growth Rates   总被引:1,自引:1,他引:0       下载免费PDF全文
Specific growth rate constants were used to evaluate the effects of selected herbicides on Erwinia carotovora, Pseudomonas fluorescens, and Bacillus sp. Comparison of growth rate constants permitted the identification of either stimulatory or inhibitory effects of these substances. E. carotovora was inhibited by 6,7-dihydrodipyrido(1,2-a:2'-c)pyrazinediium (diquat) and 4-hydroxy-3,5-diiodobenzonitrile (ioxynil) at 25 mug/ml; 1,1'-dimethyl-4,4'-bipyridinium (paraquat) at 50 mug/ml; and pentachlorophenol (PCP) at 10 mug/ml. P. fluorescens was inhibited by paraquat and PCP at 25 mug/ml and by 4-amino-3,5,6-trichloropicolinic acid (picloram) at 50 mug/ml. Stimulation of P. fluorescens was observed with 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline (nitralin) at 25 mug/ml. The Bacillus species was inhibited by diquat (25 mug/ml), ioxynil (10 mug/ml), and paraquat and PCP (5 mug/ml). No significant effect of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine), 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), alpha,alpha,alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), or 1,1-dimethyl-3-(alpha,alpha,alpha-trifluoro-m-tolyl)urea (fluometuron) on growth rates of the bacteria was observed at 25 and 50 mug/ml.  相似文献   
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