Six men were studied to determine the interrelationships among blood supply, motor unit (MU) activity and lactate concentrations during intermittent isometric contractions of the hand grip muscles. The subjects performed repeated contractions at 20% of maximal voluntary contraction (MVC) for 2 s followed by 2-s rest for 4 min with either unhindered blood circulation or arterial occlusion given between the 1st and 2nd min. The simultaneously recorded intramuscular MU spikes and surface electromyogram (EMG) data indicated that mean MU spike amplitude, firing frequency and the parameters of surface EMG power spectra (mean power frequency and root mean square amplitude) remained constant during the experiment with unhindered circulation, providing no electrophysiological signs of muscle fatigue. Significant increases in mean MU spike amplitude and frequency were, however, evident during the contractions with arterial occlusion. Similar patterns of significant changes in the surface EMG spectra parameters and venous lactate concentration were also observed, while the integrated force-time curves remained constant. These data would suggest that the metabolic state of the active muscles may have played an important role in the regulation of MU recruitment and rate coding patterns during exercise.

Enantioselective propargylic etherification of propargylic esters with not only aliphatic alcohols but also phenols in the presence of a catalytic amount of copper-Pybox complex gives the corresponding propargylic ethers in good to high yields with a high to excellent enantioselectivity (up to 99% ee). The result described here provides the first successful example of enantioselective propargylic etherification.

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The study was undertaken to measure plasma interleukin-1 (IL-1) receptor antagonist and IL-10 concentrations in patients with acute myocardial infarction and to analyze their relationship to the hemodynamics, severity, and prognosis of myocardial infarction in its acute stages. We attempted to define the kinetics of IL-1 receptor antagonist and IL-10 in patients with acute myocardial infarction (n = 34, age 42-91 years, mean 68 years). Plasma IL-1 receptor antagonist and IL-10 levels were measured by enzyme-linked immunosorbent assay. Patients in group A (n = 17) had uncomplicated acute myocardial infarction (Killip class I). Patients in group B (n = 17) had severe acute myocardial infarction (Killip class II, III, or IV). Peak Il-1 receptor antagonist and IL-10 levels in group B were significantly higher (p < 0.05) than those of group A. In group B, the peak IL-1 receptor antagonist levels were significantly correlated with white blood cell counts (r = 0.63, p = 0.006), pulmonary capillary wedge pressure (r = 0.78, p = 0.0002), and cardiac index (r = -0.51, p = 0.04). Peak IL-10 levels were significantly correlated with white blood cell counts (r = 0.60, p = 0.01), the pulmonary wedge pressure (r = 0.73, p = 0.0008), and cardiac index (r = -0.50, p = 0.04). Moreover, a significant correlation was found between the peak IL-1 receptor antagonist and IL-10 levels (r = 0.91, p < 0.0001). The peak IL-1 receptor antagonist levels in nonsurvivors (n = 13) were significantly higher (p < 0.01) than those in survivors (n = 21). The plasma IL-1 receptor antagonist and IL-10 levels were closely correlated with the severity of hemodynamics in acute myocardial infarction and with the clinical status of patients with severe acute myocardial infarction. Results suggest that plasma IL-1 receptor antagonist and IL-10 can serve as prognostic indicators in cases of sever acute myocardial infarction.