Posttraumatic stress disorder and traumatic hand injuries: a neuro-occupational view.

Using the clinical phenomenon of posttraumatic stress disorder related to traumatic hand injuries, this article conceptually explores the theoretical construct of neuro-occupation on the basis of these conditions. Neuro-occupation is an evolving concept that combines knowledge and understanding of occupation with knowledge and understanding of how the human brain functions in environmental context; thus, the concept is important to the core of occupational therapy practice. The first section of the article introduces the concept of neuro-occupation; the second provides an overview of posttraumatic stress disorder and traumatic hand injury. To help therapists better understand behavior seen in clinical settings, the third section presents key neuro-occupational processes pertaining to posttraumatic stress disorder, using clinical application examples. Finally, a query about the value of neuro-occupation as a developing theoretical construct is put forth.     

Kongreßankündigungen

Ohne Zusammenfassung

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Editorial

     

Extracellular glutamate and dopamine measured by microdialysis in the rat striatum during blockade of synaptic transmission in anesthetized and awake rats

We investigated the effect of high dose tetrodotoxin (TTX) on microdialysis measurements of extracellular striatal glutamate and dopamine in normal female rats. Both halothane-anesthetized rats with acutely implanted microdialysis probes and awake rats with microdialysis probes implanted for 24 h were tested. Glutamate levels in awake rats were 45% higher than those of anesthetized rats. Extracellular glutamate remained TTX-insensitive irregardless of TTX concentration, anesthesia, or time lapsed after probe implantation. In contrast, TTX reduced dialysate dopamine in all TTX concentrations tested. We speculate that the lower glutamate levels in anesthetized rats reflect the effect of anesthesia. Because glutamate is involved, either as a reactant or a product in a variety of reactions critical to intermediary metabolism in the brain, basal dialysate glutamate levels might indirectly reflect brain metabolism. Further, we conclude that extracellular glutamate collected during non-stimulated conditions is TTX-insensitive. The fact that glutamate levels are TTX-independent does not rule out that glutamate is synaptic in origin but rather demonstrates that it is not nerve impulse-dependent. However, the brain interstitial glutamate pool accessible to the microdialysis probe during control conditions is most likely isolated from the synapse, and therefore does not impose a neurotoxic potential.     

Isolation and amino acid sequence of caudoxin,a presynaptic acting toxic phospholipase A2 from the venom of the horned puff adder (Bitis caudalis)

A presynaptic acting toxic phospholipase A₂, designated caudoxin, was purified from the venom of Bitis caudalis by a combination of gel filtration and ion-exchange chromatography. The specificity of the enzyme was shown to be of the A₂ type. The enzyme contains 121 amino acid residues in a single chain and is cross-linked by seven disulfide bridges. Application of cyanogen bromide cleavage and digestion with trypsin and chymotrypsin yielded peptides providing the necessary overlaps to complete derivation of the sequence. Structural features of caudoxin in relation to other toxic and non-toxic phospholipases A₂ are discussed.     

Cytogenetic findings in phyllodes tumors of the breast: Karyotypic complexity differentiates between malignant and benign tumors

Clonal karyotypic abnormalities were detected in short-term cell cultures from six phyllodes tumors of the breast. Whereas all five benign tumors had simple chromosomal changes, the highly malignant one had a near-triploid stemline, indicating that karyotypic complexity is a marker of malignancy in phyllodes tumors. Interstitial deletions of the short arm of chromosome 3, del(3)(p12p14) and del(3) (p21p23), were the only aberrations in two benign tumors. Cytogenetic polyclonality was detected in three benign tumors: two had cytogenetically unrelated clones, whereas the third had three different, karyotypically related cell populations as evidence of clonal evolution. The finding of clonal chromosome abnormalities in both the epithelial and connective tissue components of the phyllodes tumors indicates that they are genuinely biphasic, that is, that both components are part of the neoplastic parenchyma.