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Biomedical subjects

K Berbaum

Publications and source records attributed to K Berbaum.

12 recordsLinked to original sources
PubMed1992

Effect of antineoplastic agents on smooth muscle cell proliferation in vitro: implications for prevention of restenosis after transluminal angioplasty.

The effect of several antineoplastic agents on vascular smooth muscle cell proliferation was studied in vitro. Both fluorouracil and cytarabine produced significant concentration-dependent inhibition of smooth muscle cell proliferation in cultured porcine pulmonary artery in vitro, while cyclophosphamide stimulated growth. For fluorouracil, inhibition was near maximal at a concentration of 13.0 microgram/mL and was seen with both coincubation and 2-hour preincubation of fluorouracil with quiescent cells. Fluorouracil is a promising agent for inhibition of intimal proliferation. Further work is warranted to determine its effect in vivo.

Angioplasty, Balloon↗
PubMed1990

Effect of conflicting cues on information processing: the 'Stroop effect' vs. the 'Simon effect'.

This study examined the relationship between two sources of interference in human information processing: the Stroop effect and the Simon effect. Forty subjects pressed a left- or right-hand key in response to a Stroop color word located on the left or right side of a screen. For one group, ink color was the relevant cue and, for another group, word meaning was the relevant cue. Independent variables were: congruence, i.e., agreement or lack thereof between the ink color and meaning of the Stroop word; spatial correspondence, i.e., agreement or lack thereof between the location of the Stroop word and the location of the key used to make the response; and stimulus duration, i.e., 400 or 100 ms. Each of these variables had a significant effect on RT, and there were no significant interactions. According to Sternberg's additive-factor logic, these findings suggest that the Stroop effect (congruence) and the Simon effect (spatial correspondence) involve separate stages of processing. If one assumes that manipulation of stimulus duration effects the encoding stage, then results also suggest that neither the Stroop effect nor the Simon effect involves the stimulus encoding stage.

Attention↗
PubMed1990

The incidence of serious hemodynamic changes in physically-limited patients following oral dipyridamole challenge before thallium-201 scintigraphy.

Dipyridamole has liberalized referrals for stress TI-201 chloride (thallium) studies at the Iowa City Veterans Administration Medical Center. Seventy-five percent of referrals now receive dipyridamole and, unlike patients who tolerate conventional exercise testing, these patients are often quite debilitated. Therefore, the hemodynamic consequences of dipyridamole were reviewed in 120 consecutive, physically-limited patients referred for thallium scintigraphy following an average oral dose of 5.4 mg/kg. Each patient's blood pressure was measured every 5 minutes for 1 hour after dipyridamole and compared with several clinical factors to determine if blood pressure change was predictable. In all patients, blood pressure changed from 136 +/- 21/83 +/- 15 (mean +/- 1 SD) to 117 +/- 25/72 +/- 15 following dipyridamole administration. One hundred nine of the 120 patients had a blood pressure decline from 137 +/- 21/82 +/- 12 to 113 +/- 21/70 +/- 13. Of the 109, 43% (N = 47) had a systolic blood pressure decline greater than 20 mmHg, 16% (n = 18) greater than 40 mmHg, and 13% (n = 14) greater than 50 mmHg. Thirteen percent (n = 14) required emergent reversal of the dipyridamole with aminophylline. Significant hypotension is relatively common but generally unpredictable after oral dipyridamole. Therefore, patient eligibility criteria should be carefully considered; strict hemodynamic monitoring must be routine in the usual patient undergoing thallium scintigraphy after oral dipyridamole challenge.

Administration, Oral↗
PubMed1988

Small bowel enteroclysis survey.

A survey questionnaire was sent to 125 radiology programs to determine the frequency and indications for the use of small bowel enteroclysis. Sixty-seven of the 84 respondents perform small bowel enteroclysis while 17 do not. The 3 most common indications for enteroclysis are detection of unexplained gastrointestinal bleeding, partial small bowel obstruction, and Crohn's disease. We conclude that although small bowel enteroclysis is a well-established examination, there are wide differences in the frequency with which it is performed, the techniques of examination, and indications for its use.

Barium Sulfate↗
PubMed1985

Reaction time to word meaning and ink color of laterally-presented stroop stimuli: effects of handedness and sex.

In two experiments, subjects pressed a key labeled Red or Green in response to a 100 msec duration stimulus presented to the left or right visual field. In Experiment I, subjects responded to the meaning of Stroop words; the stimulus was the word Red or Green printed in red, green, or white ink. In Experiment II, subjects responded to ink color; the stimulus was either the word Red or Green printed in red or green ink or a red or green color patch. In each experiment, there were 20 strongly right-handed subjects and 20 strongly left-handed subjects. Half the subjects in each handedness group were male and half were female. In both experiments, RT was faster when words were presented to the right visual field than to the left visual field, suggesting that both meaning and ink color of Stroop words were processed more quickly in the left hemisphere. Results of both experiments revealed faster reactions when meaning and ink color of the Stroop words were congruent than when they were not. A comparison with baseline trials indicated that the RT difference between responses to congruent and incongruent Stroop words was due to the incongruent cue interfering with information processing rather than to the congruent cue facilitating processing. Hypothesized interactions between stimulus position, congruence, handedness and sex were not significant.

Adolescent↗
PubMed1977

A phantom-motion aftereffect.

Motion aftereffects, typically found to result only from localized retinal stimulation, were obtained within regions of the visual field that had not been stimulated by moving contours. "Phantom" stripes are seen moving through a physically homogeneous (empty) region of the visual field when vertical stripes move above and below that region. Immediately afterward, stationary stripes in the previously empty region appear to move in the opposite direction. This phantom-motion aftereffect provides a novel instance of the way global structure affects processes that have been assumed to be influenced only by simpler local spatial and temporal variables.

Afterimage↗
PubMedDate not supplied

The effect of comparison films upon resident interpretation of pediatric chest radiographs.

Radiology residents beginning training or at the end of the first, second, or third year of training served as observers in a study of the effect of previous or comparison radiographs upon the interpretation of current pediatric chest films. For physicians early in residency, a substantial improvement in detection accuracy occurred when a prior normal film was presented with each examination. Facilitation of a lesser magnitude was obtained for specific diagnosis (classification) of lesions. Thus, while normal comparison films may help reveal to the newer resident that an abnormality exists, it does less to reveal the nature of that abnormality. For physicians late in residency, the same difference in detection accuracy between groups was obtained, but the magnitude of the difference was quite small. However, substantially higher accuracy of specific diagnosis resulted when comparison films were available. While neither normal nor abnormal comparison films markedly changes the accuracy of detection by advanced residents, both improve diagnosis.

Educational Measurement↗