Subject(s)
Child Abuse , Smoking/adverse effects , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , PregnancySubject(s)
Lung Neoplasms/pathology , Pathology, Surgical/standards , Peer Review/methods , Humans , United StatesABSTRACT
An assay is described which detects saxitoxin (STX) and tetrodotoxin (TTX) by their competitive displacement of [3H]saxitoxin from its receptor in rat brain membranes. The assay has a sensitivity of 0.15 ng STX/ml and 0.8 ng TTX/ml for buffer samples. The assay was also applied to detection of these toxins in unextracted human plasma and found to have a sensitivity of 0.5 ng STX/ml and 0.6 ng TTX/ml. The competitive displacement assay appears to be the most sensitive procedure yet for detection of STX and TTX.
Subject(s)
Saxitoxin/analysis , Sodium Channels , Tetrodotoxin/analysis , Amphibian Proteins , Animals , Binding, Competitive , Brain/metabolism , Carrier Proteins/metabolism , Humans , Male , Microchemistry , Rats , Rats, Inbred Strains , Saxitoxin/blood , Tetrodotoxin/bloodABSTRACT
T-2 toxin in serum, urine, and saline was analyzed by a modified radioimmunoassay procedure. The specimens were added directly to the assay tubes without extraction steps. The reaction between antibody and ligands was optimal at 1 h. Albumin-coated charcoal was used to separate bound from free radioactivity. Quenching, which occurred with hemolyzed specimens, was corrected by a wet oxidation process with 60% perchloric acid and 30% hydrogen peroxide. The shorter incubation times resulted in an assay that takes less than 6 h to complete. The average affinity constant of the antibody (Km) was 1.75 X 10(10) liters/mol. The sensitivity was 1 ng per assay or 10 ng/ml. Among the other trichothecenes tested, only H-T-2 cross-reacted significantly (10.3%).
Subject(s)
Radioimmunoassay/methods , Sesquiterpenes/analysis , T-2 Toxin/analysis , Antibody Affinity , Cross Reactions , Humans , T-2 Toxin/immunologyABSTRACT
A ligand assay specific for cobalamin that uses mouse stomach as the source of intrinsic factor has been developed. When mouse stomach extract incubated with radiocobalamin is fractionated by gel chromatography, the radioactive complex elutes as a single peak with apparent molecular weight of 54,900. Formation of the complex is greater than 98% inhibited by human anti-intrinsic factor antibody. When the equivalent of 10,000 pg/ml of cobinamide is added to serum, the apparent cobalamin concentration detected averages 8.5 pg/ml. Correlation with the Lactobacillus leichmannii microbiologic assay results in the regression equation y = 0.97x + 20. In six patients who had megaloblastic anemia the serum cobalamin by the mouse intrinsic factor ligand assay ranged from 0 to 9 pg/ml. Because the primary source of intrinsic factor is free of R proteins, there is no need for extensive purification of the extract. The assay is sensitive, precise, and accurate, and no more difficult to perform than other conventional ligand assay procedures.
