Biomedical subjects

B L Bolland

Publications and source records attributed to B L Bolland.

3 recordsLinked to original sources

PubMed1998

Neonatal piglet model of intraaortic balloon pumping: improved efficacy using echocardiographic timing.

BACKGROUND: Pediatric intraaortic balloon pumping (IABP) has met with little success because of technical difficulty in tracking rapid heart rates. This study was designed to evaluate the efficacy of M-mode echocardiography for IABP timing in a neonatal piglet model. METHODS: Two groups of piglets underwent mitral valve avulsion to create a model of shock. Group 1 (n = 8; mean weight, 7.7+/-1.8 kg) underwent IABP timed with both the ascending aortic pressure and M-mode echocardiogram. Group 2 (n = 6; mean weight, 7.5+/-1.4 kg) underwent two separate periods of IABP: one with echocardiographic timing and the second using standard timing points from the femoral arterial pressure tracing and electrocardiogram. Measurements included ascending aortic flow, left anterior descending arterial flow, ascending aortic pressure, left atrial pressure, and heart rate. RESULTS: Mitral valve avulsion produced a shock model with a significant decrease in mean aortic pressure and aortic flow and a significant increase in left atrial pressure and heart rate. Compared with the shock state, IABP in group 1 animals resulted in a significant increase in aortic flow (353+/-152 versus 454+/-109 mL/min; p < 0.05) and a significant decrease in left atrial pressure (23+/-6 versus 17+/-7 mm Hg; p < 0.05). Group 2 animals with echocardiogram-timed IABP had significantly increased aortic flow (365+/-106 versus 458+/-107 mL/min; p < 0.05) and mean aortic pressure (43+/-11 versus 52+/-8 mm Hg; p < 0.05). However, standard-timed IABP failed to show any improvement. CONCLUSIONS: In piglets with rapid heart rates, echocardiogram-timed IABP results in increased aortic flow and pressure and decreased left atrial pressure compared with standard-timed IABP.

Animals↗

PubMed1993

Memory for spatial locations, motor responses, and objects: triple dissociation among the hippocampus, caudate nucleus, and extrastriate visual cortex.

Based on behavioral procedures aimed at measuring working or data-based memory for spatial location, response, and visual object information, it is shown that there is a triple dissociation among the hippocampus, caudate nucleus, and extrastriate visual cortex in mediating spatial location, response, and visual object information, respectively. The hippocampus appears to subserve only spatial location, the caudate nucleus only response, and the extrastriate visual cortex only visual object information. The results support the neurobiological foundation of the attribute memory model.

Animals↗

PubMed1993

Phencyclidine disrupts long- but not short-term memory within a spatial learning task.

In the first experiment rats with 1, 2, 3 or 4 mg/kg phencyclidine (PCP), or saline injections were tested for acquisition or retention of a cheese board spatial task (dry land version of a water maze). Results indicate that relative to controls or rats with injections of 1 and 2 mg/kg PCP, rats with 3 or 4 mg/kg PCP injections were impaired in acquisition and retention of the task as measured by increased distances traveled to find the correct food location. This impairment was primarily observed in between days but not within days performance. In the second experiment rats with 4 mg/kg PCP or saline injections were tested for memory performance of a delayed spatial matching-to-sample task. Results indicate that relative to controls rats with 4 mg/kg PCP injections were not impaired at either 1-5 or 30 s delays. It is suggested that PCP through its blocking action of the NMDA receptor mediates long- but not short-term memory for spatial location information as well as the ability to retrieve previously learned spatial location information.

Analysis of Variance↗