Peak velocities of visually and nonvisually guided saccades in smooth-pursuit and saccadic tasks

 Smooth pursuit typically includes corrective catch-up saccades, but may also include such intrusive saccades away from the target as anticipatory or large overshooting saccades. We sought to differentiate catch-up from anticipatory and overshooting saccades by their peak velocities, to see whether the higher velocities of visually rather than nonvisually guided saccades in saccadic tasks may be found also in saccades in pursuit. In experiment 1, 12 subjects showed catch-up, anticipatory, and overshooting saccades to comprise 70.4% of all saccades in pursuit of periodic, 30°/s constant-velocity targets. Catch-up saccades were faster than the others. Saccadic tasks were run as well, on 19 subjects, including the 12 whose pursuit data were analyzed, with target-onset, target-remaining (saccade to the remaining target when the other three extinguish), and antisaccade tasks. For 17 of the 19 subjects, antisaccade velocities were lower than for either target-onset or target-remaining tasks. Velocities for the target-remaining task were near those for target onset, indicating that target presence, not its onset, defines visually guided saccades. Error and reaction-time data suggest greater cognitive difficulty for target remaining than for target onset, so that the cognitive difficulty of typical nonvisually guided saccade tasks is not sufficient to produce their lowered velocity. To produce reliably, in each subject, catch-up and anticipatory saccades with comparable amplitude distributions, nine new subjects were asked in experiment 2 to make intentional catch-up and anticipatory saccades in pursuit, and were presented with embedded target jumps to elicit catch-up saccades, all with periodic target trajectories of 15°/s and 30°/s. Velocities of intentional anticipatory saccades were lower than velocities of intentional catch-up saccades, while velocities of intentional and embedded catch-up saccades were similar. Target-onset and remembered-target saccadic tasks were run, showing the expected higher velocity for the target-onset task in each subject. Both experiments demonstrate higher peak velocities for catch-up saccades than for anticipatory saccades, suggesting that cortical structures preferentially involved in nonvisually guided saccades may initiate the anticipatory and overshooting saccades in pursuit. Received: 1 December 1995 / Accepted: 25 February 1997     

Pharmacological activity of the furfuryl amine salt of 4-chloro-N-(2-furylmethyl)-5-sulfamoyl anthranilic acid

Furfuryl amine salt of 4-chloro-N-(2-furylmethyl)-5-sulfamoyl anthranilic acid was shown to exert more pronounced diuretic and saluretic action in rats, mice and dogs than that of furosemide. The previous administration of furfuryl amine salt of furosemide promoted normalization of the excretory processes of the kidney and increased survival rate of rats in ischemia of the single kidney. The antiedema activity of the drug was found to be much more pronounced than that of furosemide.     

Naphthalimido derivatives as antifolate thymidylate synthase inhibitors

A new series of N-(substituted)benzyl-1,8-naphthalimides 4, structurally related to the previously reported thymidylate synthase (TS) inhibitor naphthaleins 3, were synthesized and compounds tested for their inhibition of several species of TS. Moreover, their in vitro cytotoxicity together with antimycotic and antibacterial properties were assayed. While no activity was detected in the antibacterial tests, the m-nitro (4ae) and the p-nitro (4af) derivatives were found able to partially inhibit TS at low micromolar concentrations. Introduction of nitro or (substituted)-amino groups in position 4 of the naphthalic ring always led to less active compounds.     

Principles of formalization of the syndrome diagnosis used in an automated system of management of patients

Conclusion The method of diagnosis of diseases based on the syndrome analysis is generally acknowledged. It should be noted that the methods described in this work formalize such important concepts as symptom, symptom-complex, simple and complicated syndromes, degrees of their manifestation and certainty, and their diagnostic value. The diagnostic algorithms developed on the basis of these concepts save the physician a great deal of routine work (studying results of numerous analyses and examinations) and provide consultative aid. Syndrome diagnosis of renal diseases has been considered as an example. Diagnostic systems using the method of early diagnosis of diseases described in this work will provide improved quality and reliability of diagnosis because monitoring of pathological deviations is performed automatically. The physician is immediately informed about revealed pathological deviations, symptoms, and syndromes; exacerbation of chronic diseases and appearance of new diseases. The automated system makes card catalogs unnecessary, being more expedient. Also, the automated system provides necessary reference information. Sechenov Moscow Medical Academy. Institute for Problems of Management, Russian Academy of Sciences, Moscow. Translated from Meditsinskaya Tekhnika, No. 3, pp. 20–26, May–June, 1998.