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.     

Bone disease in primary biliary cirrhosis: Lack of association with distal renal tubular acidosis

Background and Aims: Primary biliary cirrhosis (PBC) might be complicated by osteoporosis, whose etiology remains unknown but seems to be multifactorial. Prevalence rates of 30% to 60% for distal renal tubular acidosis (DRTA) have been reported in PBC patients, generally as incomplete DRTA. Although it is undisputed that a reduced bone mineral density (BMD) is the expected outcome among patients who have been suffering from longstanding chronic metabolic acidosis, it is unclear if incomplete DRTA is also associated with metabolic bone disease in PBC patients. The present study was undertaken to compare the BMD of PBC patients with and without DRTA.
Methods: The BMD of 23 PBC patients (11 with DRTA and 12 without), all with normal clearance of creatinine, was assessed by dual energy radiograph absorptiometry. The diagnosis of DRTA was made if the urine pH was above 5.4 in all samples after the oral acid overload, showing tubular inability to acidify urine in the presence of test-induced systemic metabolic acidosis.
Results: Densitometric signs of osteoporosis were found in 82% of DRTA cases and in 83% of patients without DRTA (difference not significant). There were no significant differences in BMD measurement, T and Z scores of patients with and without DRTA.
Conclusions: The present study could not support a correlation between the presence of DRTA and the bone loss observed in PBC patients.     

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.