Biomedical subjects

A G Baker

Publications and source records attributed to A G Baker.

35 records · Page 2Linked to original sources

PubMed1996

Infected iliac pseudoaneurysm after uncomplicated percutaneous balloon angioplasty and (Palmaz) stent insertion: a case report and literature review.

Percutaneous balloon angioplasty and endovascular stent placement are becoming common techniques intended to reduce the need for surgical bypass procedures that may be more expensive or have higher morbidity rates. Prophylactic antibiotics are not currently used before stent placement in most centers even when implanted via the femoral route. Infectious complications have been rare. In the case presented here an infected common iliac pseudoaneurysm occurred after percutaneous balloon angioplasty and stent placement. The literature is reviewed.

Aneurysm, False↗

PubMed1995

Effects of reward and response costs on inhibition in ADHD children.

This study examined effects of reward and response costs on the ability of 19 attention-deficit hyperactivity disorder (ADHD) and 17 control children to inhibit responding. Children were tested under 4 reinforcement conditions on a go/no-go learning task developed by J. P. Newman, C. S. Widom, and S. Nathan (1985). Two conditions involved both reward and response costs. 1 response costs only, and 1 reward only. ADHD children made more commission errors than controls across the 4 conditions. Analyses of learning curves indicated that group differences became larger on later trials. Thus, impaired inhibition was more generalized in ADHD children than in the psychopaths and extraverts studied by Newman and colleagues, and it became most evident when the children were required to improve learning across trials.

Attention Deficit Disorder with Hyperactivity↗

PubMed1987

In vivo anticalculus effect of a dentifrice containing 0.5% zinc citrate trihydrate.

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Child↗

PubMed1986

Some effects of early monocular deprivation in the Mongolian gerbil.

The effects of short- and long-term early monocular deprivation were investigated in 4 Mongolian gerbils using interocular differences in grating acuity as a measure of deprivation-induced impairment. All gerbils showed acuity deficits in the initially deprived eye, ranging in magnitude from 0.24-1.40 octaves. One month of monocular deprivation from eye opening proved sufficient to induce a permanent acuity impairment.

Animals↗

PubMed1985

Latent inhibition, habituation, and sensory preconditioning: a test of priming in short-term memory.

Four experiments tested priming in short-term memory as a model for latent inhibition and habituation. The model postulates that the two phenomena results from reduced processing when a representation of the target stimulus is already active (primed) in short-term memory at the time of its presentation. Priming is assumed to depend on the integrity of an association formed between the contextual stimuli and the conditional stimulus (CS) during exposure. Using a procedure that should have overshadowed the context, Experiment 1 found that latent inhibition and habituation were nevertheless maintained when a second CS of either equal or shorter duration overlapped with the target during exposure. Experiments 2, 3, and 4 showed that sensory preconditioning as well as habituation and latent inhibition were obtained with compound exposure, providing reasonable evidence that the added CS was indeed processed along with the target during exposure. These results are interpreted as being inconsistent with the priming model.

Animals↗

PubMed1983

Grating acuity of the Mongolian gerbil (Meriones unguiculatus).

The grating acuity of the Mongolian gerbil was measured using a two-alternative forced-choice task in a jumping stand. Frequency-of-seeing curves generated by a modified method of limits indicated that the acuity of the gerbil for a horizontal square-wave grating is about 1.5-2.0 cycles/degree (c/deg) at 70 cd/m2, using the 70%- and 80%-correct levels of performance as criteria for defining acuity. The acuity for horizontal gratings is reliably better than that for vertical gratings, and this difference does not appear to be luminance-dependent. A corresponding orientation anisotropy is not seen in acquisition scores, nor is an 'oblique effect' evident. The acuity of the gerbil continues to increase with luminance into the (human) photopic range, suggesting the existence of a functional cone system. The gerbil visual system appears to be well adapted for detail vision in a diurnal lifestyle.

Animals↗

PubMed1982

Pain, control over treatment, and compliance in dialysis and transplant patients.

Pain was surveyed via structured interview and the McGill Pain Questionnaire in 53 dialysis and 27 transplant patients. Increased patient control over the dialysis procedure was not associated with a reduction in pain though perceived control may have been. Compliance with the dialysis regimen did not predict pain and the validity of the category "dialysis headache" was questioned. Overall, transplant recipients did not report significantly less pain than dialysis patients. Self-reported depression was correlated positively with pain. The clinical implications of these findings are discussed.

Adult↗

PubMed1981

Contextual conditioning and the US preexposure effect in conditioned fear.

A series of five experiments was carried out in which fear of context caused by exposure to shocks was manipulated by signaling the shocks with a discrete stimulus, signaling the days during which shocks occurred with a session-long stimulus, or switching the context between exposure and the subsequent test. All these manipulations influenced fear of the context in the manner predicted by the Rescorla-Wagner associative model. Following this, all the rats were given conditioning trials with shock and a different discrete stimulus. All preexposure treatments produced consistent and reliable interference with conditioning with the exception of signaling the shocks with a discrete stimulus, which greatly reduced interference. These results are interpreted as being consistent both with a cognitive explanation of the US exposure effect, which claims that animals learn that shocks are unpredictable during conditioning and this knowledge retards future conditioning when they are predictable, and with an adaptation explanation, which claims that unpredictable shocks produce chronic fear and this fear through either a change in adaptation level or through emotional exhaustion renders the shocks less reinforcing during the conditioning test.

Adaptation, Psychological↗

PubMed1973