Anticoagulation for the Acute Management of Ischemic Stroke

Few prospective studies support the use of anticoagulation during the acute phase of ischemic stroke, though observational data suggest a role in certain populations. Depending on the mechanism of stroke, systemic anticoagulation may prevent recurrent cerebral infarction, but concomitantly carries a risk of hemorrhagic transformation. In this article, we describe a case where anticoagulation shows promise for ischemic stroke and review the evidence that has discredited its use in some circumstances while showing its potential in others.     

Expression of motility in strains of the non-motile species Aeromonas media

Abstract Four isolates of the non-motile species Aeromonas media , icluding the type strain, were demonstrated by transmission electronk microcopy to possess polar flagella. Motility appeared to be restricted to old, regularly subcultured strains, and coincided with an increase in colony size and a concomitant reduction in the amount of brown diffusible pigment produced by colonies on tryptone soya agar.     

THE BLOCKAGE OF AXOPLASMIC FLOW OF PROTEINS BY COLCHICINE AND CYTOCHALASINS A AND B

Abstract— Colchichine blocks axoplasmic flow of proteins in chicken sciatic nerve. The slow component is more effectively blocked than the fast. The colchicine effect on slow flow is independent of the time delay between colchicine injection and that of the [¹⁴C]-leucine used to measure flow, over a period extending from 2 h after to 9 days before the leucine. It is still effective, but to a lesser degree, after a period of 27 days. There is little effect on the fast component when the colchicine is administered after leucine. When given before leucine the effect is not pronounced up to a time interval of 1 day. Maximum blockage was obtained with longer intervals of up to 27 days. These results are discussed in relation to the involvement of the microtubules in both slow flow and rapid flow.
The effect of both cytochalasins A and B on slow and rapid protein flow has also been studied. Neither drug had any significant effect on slow flow. Cytochalasin A reduced the amount of protein flowing at the rapid rate to a small extent when administered 2 h before [¹⁴C]leucine. Cytochalasin B also caused a similar reduction and this effect was independent of dose over the ranges of doses used. The cytochalasin B diminished the incorporation of amino acid into protein in the spinal cord and it has been concluded that these results are due to a membrane effect which reduces uptake of amino acid rather than a direct effect on neurofilaments in the axons.     

Intermediates in the refolding of ribonuclease at subzero temperatures. 2. Monitoring by inhibitor binding and catalytic activity

The kinetics of refolding of ribonuclease A were monitored by the return of catalytic activity and inhibitor binding at -15 degrees C in 35% methanol cryosolvent at pH* 3.0 and 6.0. Catalytic activity was measured with cytidine 2',3'-cyclic monophosphate as substrate; inhibitor binding was determined with the competitive inhibitor cytidine 2'-monophosphate. Biphasic kinetics were observed at pH* 3.0 for both return of catalytic activity and inhibitor binding. At pH* 6.0 the rate of return of catalytic activity was monophasic, whereas that of inhibitor binding was biphasic. For both inhibitor binding and catalytic activity one of the observed rates was pH-dependent. Full return of catalytic activity was obtained at the completion of the refolding process. The observations are interpreted in terms of two parallel pathways of refolding for slow-refolding ribonuclease, with several native-like, partially folded intermediate states on the minor slow-refolding pathway. Of particular note is the presence of at least one such species that has inhibitor-binding capacity but not catalytic activity. This may be rationalized in terms of the known native structure. In addition, an intermediate is postulated which has the incorrect Pro-93 conformation and only partial catalytic activity (42% of the native). The slowest observed transient is attributed to the isomerization of this proline residue and return of full catalytic activity.