ABSTRACT
This placebo-controlled, double blind, cross-over study tested the efficacy of two different doses of Peptide T in the treatment of nine intravenous drug users with early AIDS dementia who were also receiving methadone and AZT. Subjects received Peptide T doses of either 15 or 1.5 mg daily for four weeks. Neuropsychological performance improved in four of five patients treated with the high dose, but at the lower dose, three of four patients showed no improvement on Peptide T when compared with placebo. When subjects who received the high dose were compared with those who received the low dose, a significant dose effect was found only during the active phase of the trial even after correction for differences in level of functioning at baseline.
Subject(s)
AIDS Dementia Complex/complications , AIDS Dementia Complex/drug therapy , Peptide T/administration & dosage , Peptide T/therapeutic use , Substance Abuse, Intravenous/complications , AIDS Dementia Complex/diagnosis , Adult , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Humans , Male , Middle Aged , Neuropsychological TestsABSTRACT
A novel cloning strategy, replicon rescue, was developed for cloning genes disrupted by plasmid insertions. After ligation to a tetracycline resistance cassette, fragments containing a bacterial origin of replication from the insertion are recovered in Escherichia coli because they replicate autonomously. Restriction enzymes for cloning are so chosen that the only legitimate two fragment ligation yielding TetR clones involves a fragment spanning the boundary of the insertion. Replicon rescue was used successfully firstly in a test system to clone the chromosomal orl from a Klebsiella aerogenes strain, and secondly to recover a disrupted gene from a phototaxis-deficient mutant of Dictyostelium.
Subject(s)
Cloning, Molecular/methods , Dictyostelium/genetics , Klebsiella pneumoniae/genetics , Replicon/genetics , Animals , DNA Restriction Enzymes/genetics , DNA Restriction Enzymes/metabolism , Escherichia coli/genetics , Genes, Bacterial/genetics , Genes, Fungal/genetics , Genetic Vectors/genetics , Mutagenesis, Insertional/genetics , Mutation , Plasmids/genetics , Replication Origin/geneticsABSTRACT
A method for the quantitative determination of fluoroacetate (FAC) residues in animal tissues is described. The procedure involves tungstic acid extraction, partitioning into ethyl acetate, evaporation of ethyl acetate, derivatization with pentafluorobenzyl bromide (PFB), and analysis of the resulting derivative (PFB-FAC) by capillary gas chromatography-mass spectrometry (CGC-MS) with specific ion monitoring (SIM). The tungstic acid system extracted 96.8 +/- 4.2% of the endogenous 14C-1080 residues in rat tissues. Recovery of FAC during the extraction, purification, and derivatization procedures is established by use of a 14C-FAC spike. 1,2-Dibromobenzene is used as an internal standard for the CGC-MS analysis. PFB-FAC is identified on the basis of comparative retention times and the relative intensities of m/z 257.9 and 181.0. PFB-FAC is quantitated by comparing the response at m/z 257.9 to a PFB-FAC standard curve. Routine sensitivity of the method allows determination of 10 ppb fluoroacetate in tissue.
Subject(s)
Fluoroacetates/analysis , Pesticide Residues/analysis , Animals , Fluoroacetates/metabolism , Gas Chromatography-Mass Spectrometry , Rats , Tissue DistributionABSTRACT
Four forage samples were analyzed by 16 laboratories for KNO3 content. Individual reported KNO3 values varied widely for each sample; coefficients of variation for the 4 samples were 36.0, 51.0, 12.8, and 55.0%. Recovery of KNO3 from the spiked sample averaged 105%. The analytical results, as a group, were unacceptable both statistically and for use in feeding recommendations. Three values reported could have resulted in feeding potentially toxic forage to livestock.
