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Background Percutaneous Endoscopic Gastrostomy (PEG) can involve some complications, despite the good safety of its track record. The Buried Bumper Syndrome (BBS) is a rare, late and dangerous complication that consists in the erosion of the internal bumper through the gastric wall. Case presentation We report the development of BBS in a man with chronic obstructive pulmonary disease (COPD) who had a persistent chronic cough which was prevalently but not solely in the morning and required placement of a PEG tube for continuous infusion of Levodopa/carbidopa intestinal gel for advanced Parkinson's disease. Conclusion We believe that COPD with chronic cough while not representing an absolute contraindication to PEG placement, may potentially cause BBS and therefore an appropriate regimen of tube care by expert personnel is mandatory in this setting.

In a signaled-shock situation, the signal's presence serves a warning function (prediction of shock) whereas the signal's absence serves a safety function (prediction of nonshock periods). The relative contribution to preference for signaled shock made by these two potential sources of reinforcement was assessed using a symmetrical changeover procedure in which rats were permitted to control the amount of time spent in one of two mutually exclusive conditions, the signaled and unsignaled states. The stimulus conditions that prevailed in the signaled state differed for several groups of animals. For some groups, the safety function of signals was degraded while the warning function was left intact. For other groups, the warning function was degraded and the safety function was not. The availability of the unaltered feature was then manipulated in both sets of groups to determine its effect on preference for the signaled state. Changeover behavior was strongly related to the availability of the signal's safety function and weakly related to its warning function, indicating that the two variables contribute differentially to preference for signaled shock. Other sources of behavioral control, having little to do with the safety or the warning function of signals, were also demonstrated, suggesting the need for careful control procedures when using changeover behavior as a measure of preference.

In three experiments rats were given alternating 1-minute access periods to two tubes containing sucrose solutions. When the tubes contained disparate concentrations (32% versus 4%), lick-rate was higher for the 32% solution than it was when both tubes contained 32% (a positive contrast effect) and less for 4% than when both tubes contained 4% (a negative contrast effect). Similar, but generally less pronounced, contrast effects were obtained in latency to initiate drinking. These contrast effects showed no sign of diminution with repeated exposure (32 days of repeated shifts in Experiments 1 and 3); they were not greatly influenced by injections of imipramine (Experiment 2) or chlordiazepoxide (Experiment 3), nor by deprivation conditions (Experiment 3), nor by deprivation conditions (Experiment 3). The results supported an explanation of simultaneous contrast in terms of sensory-perceptual processes rather than in terms of generalization decrement or emotional responses.

Two capuchin monkeys were trained in a delayed matching-to-sample task in which the duration that the sample was available for viewing was very brief, 0.075 to 0.45 sec. The matching performance of one animal was above chance with delay (retention) intervals as long as 4 min; the other S showed significant matching with a 2-min retention interval. The performance of both Ss was independent of sample exposure duration, indicating that their capacity to match successfully at long retention intervals is not dependent on repeated viewing of the sample stimulus. The marked practice effect shown by one S with prolonged training at 2-min delay suggests the capacity of “learning how to remember.” A constant high performance level on 2-sec delay control trials indicates that the observed practice effect was not the result of enhanced attending to the sample stimulus.

Publisher Summary Delayed matching can be dramatically facilitated by the simple operation of extinguishing all illumination during the delay (retention) interval. This chapter describes the experimental situation and procedures that are common to all of the studies of delayed matching and short-term memory in monkeys. All experimental subjects are capuchin monkeys (Cebus apella) who, before their paradigm delayed matching-to-sample (DMTS) experience, are in laboratory residence from one to four years, during which they were exposed to various kinds of experimental training. Motivation is induced by food deprivation, the animals being reduced to a body weight at which they work with reasonable diligence. After completing 15 responses on the microswitch, one of the stimuli (the sample) appears on the center projector and remains there until the subject pressed the center key for a minimum duration of 0.3 seconds. The sample then disappears and the delay (retention) interval begins.