Commentary on the Bates et al. report on eye-movement desensitization and reprocessing (EMDR)

In their 1996 paper, Bates, McGlynn, Montgomery, and Mattke were critical of eye-movement desensitization and reprocessing (EMDR) as an effective method of behavior therapy. The present commentary challenges the Bates et al. review of the literature, and the implementation of EMDR used in reaching their conclusions. Evidence is offered to support the clinical use of EMDR.

Sarcophagid larval proteins: partial sequence homologies among three cuticle proteins and related structures of drosophilids.

Three structural proteins from the larval cuticle of Sarcophaga bullata have been sequenced at the amino terminus for 30-40 residues. We observed a high degree of homology with related proteins of Drosophila melanogaster, based on the previous findings of M. Snyder, J. Hirsh, and N. Davidson [(1981) Cell 25:165-177]. S. bullata protein SC1 had 65% homology with Drosophila isolate CP1, and SC6 showed 49% homology with CPX and 54% with CP2a. The three sarcophagid polypeptides also resembled each other with respect to mapped products of tryptic cleavage. The sites of posttranslational arylation required for puparium formation, namely histidyl and lysyl residues, were asymmetrically distributed in the sarcophagid samples. In SC1 the bulk of the loci of putative crosslinks lay beyond the 43-residue fragment. In SC6 half the histidines fell within the first 25% of the primary chain.

Increased deposition of cholesterol in brain after electroconvulsive seizure.

Rats injected intracranially with cholesterol precursors and subjected to electroconvulsive seizures showed significantly higher levels of deposition of [4-14C]cholesterol into brain cholesterol than controls. The degree of incorporation was cholesterol greater than mevalonic acid greater than sodium acetate; in each case convulsed animals exceeded unshocked animals. Enhanced turnover of brain cholesterol with incorporation of circulating sterol may be associated with the etiology of convulsive seizures.

Chitin-bound protein of sarcophagid larvae: metabolism of covalently linked aromatic constituents.

The borate-insoluble chitin-protein complex, CB-I, from prepupal sarcophagid larvae was cleaved with chymotrypsin and trifluoromethanesulfonic acid releasing a polypeptide fragment of Mr 68 000. The intact glycoprotein was blocked at the C terminus; the N-terminal sequence of Asp-Val-Ala-His-Tyr was not homologous with seven of the borate-soluble nonglycosylated structural proteins. Bityrosine was identified as a component of the primary chain, both half-residues occupied in peptide linkages. Sclerotization initiated a decline in bityrosine coincident with the addition of soluble proteins to the tanned matrix. The chitin-protein complex also included bound peroxidase, propolyphenol oxidase, and an o-diphenol subject to oxidation on activation of the zymogen. In the course of the oxidation N termini declined in accordance with the formation of 1,4 quinonoid cross-links.

Crosslink precursors for the dipteran puparium.

During sclerotization of puparial proteins, tyrosine, lysine, and histidine were converted to highly basic aromatic metabolites. Peptides generated from the sclerotized cuticle with N-bromosuccinimide included the basic derivatives among the hydrolysis products. The absorbance maxima of the aromatic metabolites were 25 nm lower than those of the conventional tyrosyl peptides, with phenolic character poorly expressed or absent. Post-translational modification of the structural proteins preceded visual expression of tanning because aromatic conjugates also were present prior to pupariation. These results are consistent with a crosslinking mechanism favoring covalent bonding between protein chains.

Structural proteins of sarcophagid larval exoskeleton. Composition and distribution of radioactivity derived from [7-14C]dopamine.

In the cyclorrhaphid flies, exoskeletal proteins from the last larval instar cross-link by arylation and glycosylation to form the sclerotized puparial case. Cuticular proteins from maggots killed just prior to tanning were resolved into 21 soluble components by isoelectric focusing and sodium dodecyl sulfate-polyacrylamide electrophoresis. Isoelectric points ranged from pH 4.5 to 6.0, molecular weights were distributed between Mr = 16,000 and 24,000. Aspartic and glutamic acids, glycine, serine, valine, and lysine were abundant in all the proteins while sulfur-containing residues were uniformly absent. Heterogeneity was manifest among NH2 termini of the soluble fractions, while the insoluble chitin-linked protein showed only aspartic acid in this position. The sclerotized matrix was assembled by a concerted bridging of protomers without accumulation of di-, tri-, or higher n-mers in the urea-soluble fraction. This mechanism was also favored by uniform distribution of the bridge precursor, [7-14C]dopamine, among the individual larval protomers including the polypeptide bound to chitin. Following administration of isotopic catecholamine 2 to 10 h prior to sclerotization, unbridged larval cuticle retained 3% of the radioactivity, puparial and adult in integument 7% and 18%, respectively. Proteolytic digestion afforded labeled peptides with molecular weights in register with the degree of cross-linking. Nonradioactive larval proteins did not incorporate labeled dopamine and exchange incubation of labeled proteins with nonisotopic precursor failed to diminish recoveries of 14C. Since protein synthesis was low as assessed by minimal incorporation of [3H]leucine, metabolites derived from dopamine may have been added after translation in the course of presclerotal activation of the polypeptides destined for cross-linking.

Degradation of melanin by Aspergillus fumigatus.

A strain of Aspergillus fumigatus from composted coffee and garden wastes utilized natural deproteinized insect, banana, hair, octopus, and synthetic tyrosine and dopa melanins as sole sources of carbon. With a sucrose supplement, degradation was essentially complete after 50 days in Czapek medium pH 6.5 at 30 degrees C. The catabolic rate differed for each substrate pigment, as did the molecular weight distribution of products accumulating in the medium. After incubation with L-[U-14C]melanin, over 50% was recovered in a dark fungal pigment, the remainder appearing as cell protein, chitin, lipid, CO2, and polar metabolites. When grown on melanin, the normally pale mycelia darkened with the production of a fungal allomelanin, with infrared spectrum and alkali fusion products differing from those of the substrate pigment. Isotope distribution in amino acids for A. fumigatus grown on labeled melanin supplemented with sucrose suggested separate pools for synthesis of cell proteins and melanoproteins. Deposition of allomelanin increased resistance of conidia, sterigma, and conidiophores to lytic carbohydrases as judged by scanning electron microscopy.

The composition of peptidochitodextrins from sarcophagid puparial cases.

1. N-Bromosuccinimide cleaved proteins and pigments from fly puparia, increasing the chitin:protein ratio from 0.5 to 1.5. The product afforded subfractions (ratio 5:1) of molecular weights of 1200 and 1600 devoid of aromatic residues and N-terminal beta-alanine, direct aryl links between polysaccharide chains being discounted. 2. The chitin-protein complex decreased in molecular weight when treated with Pronase, which suggested polypeptide bridges within the native chitin micelle. The limit dextrins generated by chitinase were mixtures of unsubstituted dextrins and peptidylated oligosaccharides, with the former predominating. 3. Peptidochitodextrins of similar molecular weight but markedly different solubility were prepared, which were indistinguishable with respect to amino acid, glucosamine, acetyl, X-ray or infrared characteristics. It is suggested that physical interactions contribute to the stability of the integument in addition to the covalent bonds that form during sclerotization.