NERVOUS SYSTEM MANIFESTATIONS AFTER GASTRIC SURGERY

106 patients who had gastric surgery for peptic ulcer were examined for evidence of nervous system involvement. Sixteen patients (15.1 %) had neurological signs and eighteen (17.0%) had nervous system symptoms without signs. There were 43 nervous system manifestations which comprised myopathy, peripheral neuropathy, neuromyopathy, myeloneuropathy, myelopathy, motor neurone disease, dementia, optic atrophy, cerebellar ataxia, affective disorders, the restless legs syndrome and epilepsy. The age and sex of the patients, the site of the ulcer and the type of gastric operations did not predispose to the appearance of neurological symptoms and signs. A longer interval from the gastrectomy to the present examination was associated with a higher incidence of neurological complications. In seven of the sixteen patients with neurological signs a causative factor was thought to be identified and specific treatment was effective. These were Vitamin D deficiency and myopathy in three patients, hypokalaemia and transient paralysis in one and Vitamin B-12 and peripheral neuropathy in three. In another two patients Vitamin B-12 was deficient but there was only slight improvement with treatment. In the other patients with neurological signs, treatment was of no avail. In the eighteen patients without signs the disability was usually only slight. The relationship of Vitamin B-12, steatorrhoea and blind loop formation to the neurological signs are briefly discussed.     

Efficacy of Blake drains for mediastinal and pleural drainage following cardiac operations

BACKGROUND: Mediastinal and pleural drainage following cardiac operations has traditionally been achieved with large bore, semirigid chest tubes. The purpose of this study was to evaluate the safety and efficacy of drainage by means of small, soft, and flexible 19 F Blake drains. METHODS: This is a review of all patients who underwent heart surgery over a 3-year period at a single institution. Chest tubes and Blake drains were removed on postoperative day 1 to 5 depending on patient's condition, amount of drainage, and surgeon's preference. The criteria for drain removal did not vary with type of drain. RESULTS: There was no significant difference in the amount of drainage between both groups. Postoperative mediastinal exploration occurred in 3.47% of patients (12/346) in the chest tube group and in 2.08% of patients (8/385) in the Blake group (p = 0.27). Significant pleural effusions requiring a subsequent drainage procedure occurred in 9.54% of patients (33/346) in the chest tube group and in 9.87% of patients (38/385) in the Blake group. CONCLUSIONS: No significant differences were noted in the number of mediastinal explorations in patients drained with conventional chest tubes as compared to Blake drains during cardiac operations. Though not statistically significant, there may actually be an advantage of Blake drains over conventional chest tubes in this regard. There was also no significant difference in the incidence of postoperative pleural effusions. Blake drains appear to be at least as effective and safe as conventional chest tubes in draining the mediastinum and pleural spaces following cardiac surgery.     

Experiential input alters the phosphorylation of specific proteins in brain membranes

The effects of a training experience that involves foot shock on the endogenous phosphorylation of membrane-bound proteins from brain were studied. Crude membrane fractions were prepared from the cerebral cortex and neostriatum of animals that had been sacrificed by quick freezing. In vitro incubation of the membranes with gamma-^{3 2}P-ATP, followed by SDS-gel electrophoresis of the phosphorylated substrates, revealed that the phosphorylation of two protein components (designated F and H-I) increased in preparations from animals that were subjected to a training experience 24 hr prior to sacrifice. These effects were greater in preparations from the neostriatum than from the cerebral cortex, and were observed in experiments using both rats and mice. Although all trained animals showed a high phosphorylation of bands F and H-I, control animals showed a greater variability in the phosphorylation of these bands. The results indicate that the phosphorylation of specific proteins may play a mediatory role in the processing of experiential information.     

Post-translational protein modification as the substrate for long-lasting memory

Prevailing models of memory identify mRNA translation as necessary for long-lasting information storage. However, there are enough instances of memory storage in the virtual absence of protein synthesis to prompt consideration of alternative models. A comprehensive review of the protein synthesis literature leads us to conclude that the translational mechanism is exclusively a permissive, replenishment step. Therefore, we propose that post-translational modification (PTM) of proteins already at the synapse is the crucial instructive mechanism underlying long-lasting memory. A novel feature of this model is that non-random spontaneous (or endogenous) brain activity operates as a regulated positive-feedback rehearsal mechanism, updating network configurations by fine-tuning the PTM state of previously modified proteins. Synapses participating in memory storage are therefore supple, a feature required for networks to alter complexity and update continuously. In analogy with codons for amino acids, a long-lasting memory is represented by a 'degenerate code' - a set of pseudo-redundant networks that can ensure its longevity.