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Biomedical subjects

E J Schantz

Publications and source records attributed to E J Schantz.

At least 19 recordsLinked to original sources
PubMed1992

Properties and use of botulinum toxin and other microbial neurotoxins in medicine.

Crystalline botulinum toxin type A was licensed in December 1989 by the Food and Drug Administration for treatment of certain spasmodic muscle disorders following 10 or more years of experimental treatment on human volunteers. Botulinum toxin exerts its action on a muscle indirectly by blocking the release of the neurotransmitter acetylcholine at the nerve ending, resulting in reduced muscle activity or paralysis. The injection of only nanogram quantities (1 ng = 30 mouse 50% lethal doses [U]) of the toxin into a spastic muscle is required to bring about the desired muscle control. The type A toxin produced in anaerobic culture and purified in crystalline form has a specific toxicity in mice of 3 x 10(7) U/mg. The crystalline toxin is a high-molecular-weight protein of 900,000 Mr and is composed of two molecules of neurotoxin (ca. 150,000 Mr) noncovalently bound to nontoxic proteins that play an important role in the stability of the toxic unit and its effective toxicity. Because the toxin is administered by injection directly into neuromuscular tissue, the methods of culturing and purification are vital. Its chemical, physical, and biological properties as applied to its use in medicine are described. Dilution and drying of the toxin for dispensing causes some detoxification, and the mouse assay is the only means of evaluation for human treatment. Other microbial neurotoxins may have uses in medicine; these include serotypes of botulinum toxins and tetanus toxin. Certain neurotoxins produced by dinoflagellates, including saxitoxin and tetrodotoxin, cause muscle paralysis through their effect on the action potential at the voltage-gated sodium channel. Saxitoxin used with anaesthetics lengthens the effect of the anaesthetic and may enhance the effectiveness of other medical drugs. Combining toxins with drugs could increase their effectiveness in treatment of human disease.

Bacterial Toxins↗
PubMed1987

Complete amino acid sequence of staphylococcal enterotoxin A.

The amino acid sequence of staphylococcal enterotoxin A is presented. Staphylococcal enterotoxin A is a single-chain polypeptide which consists of 233 amino acid residues with a molecular weight of 27,078 and has the amino acid composition Cys2, Asp17, Asn19, Thr16, Ser13, Glu15, Gln12, Pro4, Gly15, Ala7, Val13, Met2, Ile10, Leu23, Tyr18, Phe8, His6, Lys24, Arg7, Trp2, with serine as both amino- and carboxyl-terminal amino acids. Automated sequence analysis of intact enterotoxin A, as well as characterization of the peptides obtained from cyanogen bromide treatment and trypsin and chymotrypsin digestion, led to the elucidation of the complete primary structure of this protein. Less structural homology is observed among staphylococcal enterotoxins A, B (Huang, I-Y., and Bergdoll, M. S. (1970) J. Biol. Chem. 245, 3518-3525), and C1 (Schmidt, J. J., and Spero, L. (1983) J. Biol. Chem. 258, 6300-6306) than that seen between enterotoxins B and C1.

Amino Acid Sequence↗
PubMed1985

Distribution of paralytic toxins in California shellfish.

Samples of Saxidomus nuttali and Mytilus californianus collected during the 1981 dinoflagellate bloom at Bodega Bay, California, were analyzed for the presence of paralytic toxins. Neck tissue of S. nuttali contained saxitoxin (STX) and neoSTX (95% of the total toxicity), whereas the bodies contained neoSTX and a mixture of the gonyautoxins. In a sample of M. californianus the presence of neoSTX and the gonyautoxins was demonstrated, whereas a second sample, collected at a different site, contained almost exclusively neoSTX.

Animals↗
PubMed1984

Isolation and some properties of an enterotoxin produced by Bacillus cereus.

Extracellular proteins produced by Bacillus cereus B-4ac were separated by chromatography on Amberlite CG-400, QAE-Sephadex, Sephadex G-75, and hydroxylapatite. A fraction, containing three detectable antigens, obtained from chromatography on hydroxylapatite caused fluid accumulation in ligated rabbit ileal loops, was dermonecrotic to rabbit skin, was cytotoxic to cultured cells, and was lethal to mice after intravenous injection. Two other fractions obtained from chromatography on hydroxylapatite showed essentially no toxic activity when tested individually. Each nontoxic fraction contained two of the three proteins present in the toxic material. When the two nontoxic fractions were combined, activity in all of the biological assays was observed. Antiserum against either of the nontoxic fractions neutralized the dermonecrotic response of the combined material. These results suggest that all of these biological activities probably are due to a single entity and that more than one component probably comprise the toxic entity.

Animals↗
PubMed1975

Mechanism of action of a new toxin from gonyaulax tamarensis on nerve membranes.

The toxin from the dinoflagellate Gonyaulax tamarensis blocks nervous conduction through a selective inhibition of the mechanism whereby the membrane undergoes an increase in permeability to sodium ions. The effect is exerted only from outside of the nerve membrane. These effects are exactly the same as those exerted by tetrodotoxin or saxitoxin.

Animals↗
PubMed1974

Scanning density gradient isoelectric focusing of Staphylococcus aureus enterotoxins B and C.

Purified Staphylococcus aureus enterotoxins B and C(1), the causative agents of staphylococcal food poisoning, were resolved into several components by scanning isoelectric focusing in sucrose density gradients in the absence and presence of 6 M urea and 5 mM dithiothreitol. The observed heterogeneity persisted in the denaturing medium, which suggests that the primary structure of protein enterotoxins B and C(1) may be partly responsible for the isoelectric point differences of the various forms. To our knowledge, the scanning isoelectric focusing patterns of staphylococcal enterotoxins B and C(1) are reported for the first time.

Centrifugation, Density Gradient↗
PubMed1969

Effect of formaldehyde on the immunochemical and biological activity of staphylococcal enterotoxin B.

Staphylococcal enterotoxin B was treated with 0.15 or 0.3% formaldehyde at 37 C and pH 7.3. As early as 8 hr after addition of HCHO, the toxin was unable to precipitate as much antibody from antiserum as untreated toxin; greater amounts of treated toxin were required to reach equivalence and to inhibit precipitation. With increasing time, its reactivity decreased so that at 32 weeks it could precipitate only 20% as much antibody as untreated toxin. When other factors were kept constant, the degree of inactivation increased as the HCHO concentration increased from 0.6 to 1.4%. Treated toxin gave a "reaction of partial identity" by the Ouchterlony double-immunodiffusion technique. The emetic effect of the toxin for the monkey remained essentially unchanged for about 48 hr of treatment, but the amount required to cause death by the intravenous route increased from 25 to over 1,000 mug/kg of body weight. HCHO destroyed the pyrogenic effect for rabbits. The treated toxin remained immunogenic for rabbits even after 4 to 5 weeks of exposure to 0.3% HCHO at 37 C.

Animals↗