404. That’s an error.
The requested URL /bookmarks/mark?op=add&bkmk=http%3A//jpet.aspetjournals.org/content/75/3/219&title=EFFECTS%20OF%20COCAINE%20AND%20SYMPATHOMIMETIC%20AMINES%20ON%20HUMORAL%20TRANSMISSION%20OF%20SYMPATHETIC%20NERVE%20ACTIONS
was not found on this server. That’s all we know.