Evoked potential in the lateral geniculate body as modified by enucleation of one eye in the albino rat

Evoked potential was recorded from the lateral geniculate body (LGB) in response to stimulation of the uncrossed optic nerve in rats with one eye removed at varying days of age after birth. A postsynaptic component of the evoked potential was found to be potentiated if the enucleation was made during the first 30 postnatal days. It was speculated that when enucleation was made during 10 days after birth potentiation would be brought about by an increase in the number of the uncrossed optic nerve fibers, but enucleation after that period would produce potentiation by terminal sprouting of the regular uncrossed optic nerve fibers. In addition, the possibility was discussed that enucleation in the first 30 days might also produce potentiation by a more efficient or more numerous transmitter release at the regular uncrossed optic nerve terminals.

Reconstitution into liposomes of membrane proteins involved in ribosome binding on rough endoplasmic reticulum. Ribosome-binding capacity

A membrane protein fraction having a high affinity for polyribosomes was isolated from microsomal membranes of rat liver and was incorporated into liposomes made from microsomal lipids to evaluate the polyribosome-binding capacity of the reconstituted liposomes, with the following results. (1) The polyribosome binding to the reconstituted liposomes depended on the amounts of polyribosomes added to the binding mixture. (2) Liposomes made from lipids alone did not bind any polyribosomes. (3) The polyribosome-binding capacity of the reconstituted liposomes was very sensitive to proteolytic enzyme and strongly inhibited by addition of 0.1 mM-aurintricarboxylic acid or by increasing KCl concentration. These results suggest that the binding mechanism of polyribosomes to the reconstituted liposomes is much like that for rough microsomal membrane stripped of endogenous polyribosomes.

Intracellular activity and morphology of the prefrontal neurons related to visual attention task in behaving monkeys

Neurons of the prefrontal-premotor cortex, which had been studied electorophysiologically during a modified reaction time task, were identified by intracellular pressure micro-injection of horseradish peroxidase (HRP). The cells were classified into those showing a sustained vs. transient change in activity during performance of the task. Cells showing a sustained response were found to have their somata in layers III and VI and cells showing transient responses were found to have their somata in layers II and III. All cells were pyramidal cells with spiny dendrites.

Topographical projections from the prefrontal cortex to the post-arcuate area in the rhesus monkey, studied by retrograde axonal transport of horseradish peroxidase

The cells of origin of ipsilateral, prefrontal cortical projections to the post-arcuate area were studied in rhesus monkeys with the horseradish peroxidase (HRP) method. Following injections of HRP into the dorsal portion of the post-arcuate area, retrogradely labeled cells appeared in the arcuate area dorsal to the principal sulcus, while, following injections into its ventral portion, labeled cells appeared in the arcuate area ventral to the principal sulcus. They were pyramidal cells and lay mainly in the III layer, but small numbers of them were also found in the IV and V layers. In addition, HRP labeled cells were seen ipsilaterally in the banks of the cingulate sulcus.

Importance of the carboxyl-terminal four amino acid residues in the inhibitory activity of Streptomyces subtilisin inhibitor (with a revision of its carboxyl-terminal sequence)

The carboxyl-terminal amino acid sequence of Streptomyces subtilisin inhibitor (SSI) was reinvestigated by analysis of the amino acid sequences of the thermolysin peptides from the C-terminal decapeptide, and the sequence -Val110-Ala-Phe-Phe113, which was reported in J. Biochem. 76, 1191-1209 (1974), was revised to -Val110-Phe-Ala-Phe113. Carboxypeptidase A digestion of SSI resulted in loss of the inhibitory activity in parallel with the release of the carboxyl-terminal four amino acid residues. The resulting modified inhibitor, des(Val110-Phe113)-SSI, possessed almost full inhibitory activity against subtilisin BPN' when the inhibitor was incubated with the enzyme in amounts less than one mol of enzyme per mol of the inhibitor. However, no inhibitor activity was observed when the molar ratio of the inhibitor to the enzyme was less than one. This phenomenon suggests that the carboxyl-terminal four amino acid residues might play an important role in the maintenance of the three-dimensional structure of SSI, which resists the action of the proteinase. The addition of more than 30-fold molar excess of SSI-(104-113)-decapeptide (C-terminal decapeptide of SSI) to the modified inhibitor resulted in refolding of the polypeptide chain, rendering it immune from proteolytic digestion.

Endoscopic evaluation of the effect of sucralfate therapy and other clinical parameters on the recurrence rate of gastric ulcers

A randomized controlled clinical study was conducted to determine (a) whether basic aluminum sucrose sulfate (sucralfate) is effective in preventing or reducing gastric ulcer recurrence, and (b) the clinical parameters contributing to ulcer recurrence after endoscopically proved healing has been effected. A total of 167 patients were assigned on a random basis to either of two treatment groups, control (aluminum hydroxide and magnesium oxide) or sucralfate, and given these medications for 6 months. At the end of this period all medication was withdrawn from both groups and the patients were followed for an additional 12 months. Each patient was examined endoscopically at bimonthly intervals throughout the 18-month observation period. Treatment (sucralfate), ulcer history, size of previous ulcer(s), prestudy healing time, and prestudy healing stage attained (red or white scarring) were associated with a significant reduction in recurrence rate. Ulcer recurrence was markedly reduced in sucralfate patients as compared to control when the pretreatment ulcers had healed slowly (P less than 0.001).