Protein synthesis in phenotypically different, single neurons of Aplysia

Different molecular weight classes of proteins from single phenotypically different neuron somas and their subcellular fractions were analyzed in terms of the relative concentration and relative labeling using sodium dodecyl sulfate (SDS) polyacrylamide microgel electrophoresis. A 12,000 (12K) molecular weight class of protein found in low relative concentration but highly labeled was shown to be present in some endogenously firing neurons, L3, L6, and L11, but not in others such as L4. A specific 12K class of protein has been found to be common to all neurosecretory neurons, R15, R14 and R3–13, studied. A high relative concentration of 6–9K class of protein in R15 and bag cells and a highly labeled 6–9K protein shown to be in R14 and R3–13 have been correlated with neurosecretion. In subcellular fractionation studies a specific 12K class of proteins was found in the membrane fraction of neuron L11. Several proteins, which have molecular weights similar to filarin (77K), tubulin (58–55K) and actin (43K) have been shown to be common to all neurons studied. Hence this study has demonstrated protein specificity in single phenotypically different neurons. Suggestive correlations of specifically translated small molecular weight proteins with neurosecretion in neurons R3–15 were made.     

Initiation of repetitive ventricular depolarizations by relatively late premature complexes in patients with acute myocardial infarction.

To determine whether repetitive ventricular depolarizations are more commonly precipitated by early compared with late premature ventricular complexes, we analyzed continuous electrocardiographic recordings obtained during the first 10 hours in 38 patients with myocardial Infarction without shock with the Argus/H computer system with editor verification of all premature ventricular complexes. Episodes of repetitive ventricular depolarization were defined as two or more consecutive complexes at a rate of 120 beats/min or greater. Premature ventricular complexes occurring with coupling intervals from the preceding normal complex equal to or less than the Q-T interval of the normal complex were defined as early, and those with longer coupling intervals as late. Among all premature ventricular complexes, early premature ventricular complexes accounted for 38 percent. The average coupling interval of premature ventricular complexes from a preceding normal complex did not correlate with heart rate, blood pressure, infarct size estimated enzymatically, the electrocardiographic locus of Infarction or history of previous Infarction. Twenty-nine patients had a total of 337 episodes of repetitive ventricular depolarizations. Somewhat surprisingly, 78 percent of these episodes, and all episodes in 22 patients, were initiated by late premature ventricular complexes. Thus, repetitive ventricular depolarizations in patients with acute myocardial infarction are often precipitated by late rather than early premature ventricular complexes.     

Abdominal wall movement in normals and patients with hemidiaphragmatic and bilateral diaphragmatic palsy

Higenbottam, T., Allen, D., Loh, L., and Clark, T. J. H. (1977).Thorax,32, 589-595. Abdominal wall movement in normals and patients with hemidiaphragmatic and bilateral diaphragmatic palsy. The abdomen and ribcage volume contribution to the tidal volume have been determined using magnetometers in three groups of subjects—normal males, patients with hemidiaphragmatic palsy, and patients with bilateral diaphragmatic palsy. In all three groups the main moving parts appear to be the anterior surfaces of the abdomen and ribcage even in the presence of bilateral diaphragmatic palsy.     

beta-Endorphin: behavioral and analgesic activity in cats.

beta-Endorphin has been shown to possess potent behavioral and antinociceptive activities when administered intraventricularly in cats. On a molar basis, beta-endorphin is 72-96 times more potent than morphine and its actions are blocked by the specific opiate antagonist, naloxone.