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Biomedical subjects

J Greenberg

Publications and source records attributed to J Greenberg.

At least 127 records · Page 7Linked to original sources
PubMed1990

Blood flow and metabolism in vasogenic oedema.

The relationship between white matter cerebral blood flow (CBF) and glucose metabolism (LCMRgl) was studied in a plasma infusion model of vasogenic oedema in cats. LCBF as determined by iodoantipyrine was found to be significantly decreased in oedematous white matter (17.3 +/- 1.5 ml/100 gm/min) when compared with contralateral control white matter (24.8 +/- 1.8 ml/100 gm/min). If the values for oedematous brain were corrected for dilution, however, the LCBF averaged 25.3 +/- 1.7 ml/100 gm/min, which was the same as control. LCMRgl was found to be significantly increased in plasma-infused white matter (16.3 +/- 2.2 mumol/100 gm/min), compared with control white matter (10.7 +/- 1.3). This difference remained despite correction for dilution and recalculation of LCMRgl values based on altered kinetic constants found in oedematous brain. A similar increase in LCMRgl was noted with saline infusion oedema. It is concluded that increased tissue water does not alter CBF, but does induce an increase in anaerobic metabolism.

Animals↗
PubMed1990

The role of the American Association for Cancer Education in pediatric oncology: results of a survey.

We designed a questionnaire to elucidate the reasons for decreased participation in activities of the American Association for Cancer Education (AACE) by 34 members who listed pediatric oncology as their primary or secondary medical interest. Nineteen members from 16 institutions, 14 of them university hospitals, returned the form. These institutions treated an average of 89 new childhood cancer patients per year and educated an average of 89 trainees per year in aspects of pediatric oncology. All respondents believed that the AACE should meet in tandem with another national convocation, and most thought that the AACE meeting was reasonably priced but expensive of time. Many indicated that they would participate more actively in the AACE if they, or their institution, had an active R25 Cancer Education Grant from the National Cancer Institute. The majority believed that the AACE should be more active in educational efforts about childhood cancer (71%), should conduct a manpower survey to ascertain the need for training fellows in pediatric oncology (77%), and should prepare educational materials on childhood cancer (65%). However, less than one-half (41%) believed that the AACE has a readily identified role in pediatric oncology education. Greater communication between the AACE and the pediatric oncology community is needed, especially in coordinating and evaluating pediatric oncology education in the United States.

Education, Medical↗
PubMed1989

Amphetamine-induced excitations predominate in single neostriatal neurons showing motor-related activity.

Neostriatal single-unit activity was recorded in freely moving rats. A majority (62%) of the 24 recorded neurons were activated during motor behavior such as locomotion (n = 11) or head movements (n = 4). The behavioral response to amphetamine (1.0 mg/kg) was associated with increases (n = 17) or decreases (n = 7) in firing rate. A significantly greater proportion of motor-related neurons were excited by the drug compared to nonmotor-related cells. These results, which confirm the heterogeneity of amphetamine-induced effects in the neostriatum, indicate that the baseline motor-response characteristics of neostriatal neurons may determine their response to amphetamine.

Action Potentials↗
PubMed1989

Development of a multidisciplinary feeding profile for children who are dependent feeders.

The multidisciplinary feeding profile (MFP) is the first statistically based protocol for the quantitative assessment of feeding disorders in severely disabled children. This assessment can be completed in 30-45 min with foods and facilities that are available in homes, hospitals, and chronic care units. This paper describes the state of current testing methods, the parameters of successful feeding activity, the development of the test protocol, and the results of statistical analyses.

Adolescent↗
PubMed1989

Sulconazole nitrate 1% cream in the treatment of chronic moccasin-type tinea pedis caused by Trichophyton rubrum.

Sulconazole nitrate 1% cream applied twice daily was compared with its vehicle in the treatment of 229 patients with chronic moccasin-type tinea pedis confirmed by positive results of a potassium hydroxide preparation. At admission in this randomized, double-blind, parallel multicenter trial, 131 patients had positive dermatophyte cultures; Trichophyton rubrum was identified in 121 (92%). After 4 weeks of treatment, patients were examined and, if necessary, were treated for an additional 2 weeks. Sulconazole cream was significantly more effective than the vehicle in the treatment of chronic T. rubrum tinea pedis; 57% of patients were cured by sulconazole, compared with 13% cured with the vehicle. Relapse rates, assessed 2 weeks after the end of treatment, were significantly lower in patients treated with sulconazole than in those receiving vehicle (27% vs 71%). The 103 patients with moccasin-type tinea pedis whose cultures were not positive for T. rubrum achieved similar results.

Adolescent↗
PubMed1989

Evidence for terror management theory: I. The effects of mortality salience on reactions to those who violate or uphold cultural values.

On the basis of terror management theory, it was hypothesized that when mortality is made salient, Ss would respond especially positively toward those who uphold cultural values and especially negatively toward those who violate cultural values. In Experiment 1, judges recommended especially harsh bonds for a prostitute when mortality was made salient. Experiment 2 replicated this finding with student Ss and demonstrated that it occurs only among Ss with relatively negative attitudes toward prostitution. Experiment 3 demonstrated that mortality salience also leads to larger reward recommendations for a hero who upheld cultural values. Experiments 4 and 5 showed that the mortality salience effect does not result from heightened self-awareness or physiological arousal. Experiment 6 replicated the punishment effect with a different mortality salience manipulation. Implications for the role of fear of death in social behavior are discussed.

Arousal↗
PubMed1989

Use of 19F NMR spectroscopy for measurement of cerebral blood flow: a comparative study using microspheres.

19F NMR was used to determine washout curves of an inert, diffusible gas (CHF3) from the cat brain. The cerebral blood flow was estimated from a bi- or tri-phasic fit to the deconvoluted wash-out curve, using the Kety-Schmidt approach. Cerebral blood flow values determined by 19F NMR show the expected responsiveness to alterations in Paco2, but are approximately 28% lower than cerebral blood flow values determined simultaneously by radioactive microsphere techniques. High concentrations of CHF3 have little effect on intracranial pressure, mean arterial blood pressure or Paco2, but cause small changes in the blood flow to certain regions of the brain. We conclude that 19F NMR techniques utilizing low concentrations of CHF3 have potential for the noninvasive measurement of cerebral blood flow.

Animals↗
PubMed1989

Elevated concentrations of acetone and unidentified compounds in the breath of alcohol abusers.

A highly sensitive gas chromatographic assay was used to measure volatile organic compounds in the breath. Samples of breath from three groups of subjects were studied: normal volunteers (n = 15), acutely intoxicated alcohol abusers (n = 11), and abstinent alcohol abusers (n = 13). Acetone levels were significantly higher in the acutely intoxicated subjects than in the normals (p less than 0.05) or the abstinent alcohol abusers (p less than 0.05). Chromatographic peaks arising from 13 unidentified compounds in the breath were observed; two of these unidentified compounds were observed only in the intoxicated and abstinent alcohol abusers. Statistically significance was achieved in only one unidentified peak; elevated levels of this compound were seen in both acutely intoxicated alcohol abusers (p less than 0.01) and in the abstinent alcohol abusers (p less than 0.01) when they were compared to normal subjects.

Acetone↗
PubMed1989

Cerebral blood flow and glucose metabolism in experimental brain edema.

The relationship between cerebral blood flow (CBF) and cerebral metabolic rate of glucose (CMRgl) in the white matter was studied in a plasma infusion model of vasogenic edema in cats. Local CBF, as determined by iodoantipyrine testing, was found to be significantly decreased in edematous white matter (mean +/- standard error of the mean: 17.3 +/- 1.5 ml/100 gm/min) when compared with CBF in the contralateral control white matter (24.8 +/- 1.8 ml/100 gm/min). When the values for edematous brain were corrected for dilution, however, the local CBF averaged 25.3 +/- 1.7 ml/100 gm/min, which was similar to the control value. Local CMRgl was found to be significantly increased in plasma-infused white matter (16.3 +/- 2.2 mumol/100 gm/min) compared with that in control white matter (10.7 +/- 1.3 mumol/100 gm/min). This difference remained, despite correction for dilution and recalculation of local CMRgl values based on altered kinetic constants found in edematous brain. A similar increase in local CMRgl was noted with saline-infusion edema. It is concluded that the increased tissue water level does not alter CBF, but does induce an increase in anaerobic metabolism.

Animals↗
PubMed1988

Depression and interpersonal attraction: the role of perceived similarity.

We hypothesized that depressed individuals are generally viewed as dissimilar and that this perceived dissimilarity contributes to negative reactions to the depressed. In addition, we hypothesized that if perceived similarity affects liking of depressed individuals, then nondepressed subjects should prefer nondepressed targets, but depressed subjects should not share this preference. To test these hypotheses, depressed and nondepressed subjects received information about two targets, both either depressed or nondepressed, one attitudinally dissimilar and one attitudinally similar. They were then asked to fill out an attraction measure and an interest in meeting measure for each target. The results clearly supported the primary hypotheses, demonstrating that nondepressed subjects preferred nondepressed targets and perceived them as more similar than depressed targets, and that this preference for nondepressed targets is not shared by depressed subjects. Tests of supplementary hypotheses also confirmed that depressed subjects perceive their best friends as being more depressed and more dissimilar than do nondepressed subjects. The implications of these findings for the social world of the depressed were discussed.

Adult↗
PubMed1988

Single vibrissal cortical column in SI cortex of rat and its alterations in neonatal and adult vibrissa-deafferented animals: a quantitative 2DG study.

1. A quantitative 2-[14C]deoxy-D-glucose (2DG) autoradiographic study was undertaken to determine the functional (metabolic) organization of an individual column in the first somatosensory cortex (SI) of the awake restrained rat. Manual or mechanically controlled brush stroking of a single vibrissa (typically C3) was used in order to evoke neural activity and increase glucose utilization in a single cortical barrel in lamina IV and in adjacent supra- and infragranular layers in register with the single cortical barrel labeling in lamina IV. 2. The single activated vibrissal column was found to extend from layer I to the superficial half of layer VI of the contralateral SI cortex and was fusiform in shape, being of largest diameter (650-micron) in layer IV and smallest diameter (200 micron) in layer VI. 3. This single metabolic column was not uniform in its density of labeling. The greatest local cerebral metabolic rate of glucose (LCMRG) was found in layer IV (170 mumol.100 g-1.min-1), layers II-III, and V had, on the average, similar LCMRG values (115 mumol.100 g-1.min-1), which decreased with distance from layer IV. 4. The functional (metabolic) columnar activity center situated in layer IV corresponded in size to the appropriate anatomical barrel as determined from thionin-stained sections. Increased metabolic activity was not strictly confined to the candle-pin-shaped column but extended tangentially as radiating fingerlike projections toward the neighboring barrels. 5. In cortical layers other than IV, the metabolic column was less prominently labeled, and the metabolic activity also branched in the tangential plane. The labeling pattern profile in upper layers was characterized by numerous lateral spreading fingerlike projections of increased glucose metabolism. 6. Neonatal follicle lesions sparing only C3 vibrissa caused a great increase (125%) in cortical territory driven by the spared whisker with a concomitant loss of columnar shape and decrease in intensity of metabolic activity in response to its stimulation. 7. Similar lesions in adult rats produced a significant increase (40%) in dimensions of the spared C3 cortical column, which was, however, smaller than that produced after neonatal lesions. The metabolic activation of layer Vb in the spared C3 column was increased (17%) compared with that of the control column.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1988

Cerebral metabolism and patterned visual stimulation: a positron emission tomographic study of the human visual cortex.

We studied the impact of visual stimulation upon cerebral metabolism in normal young men using FDG-PET. Results obtained from subjects receiving patterned visual stimulation while performing an ocular fixation task were compared with results from ocular fixation alone. Visual stimulation in the macular region of either hemifield produced significant increases in metabolism of the contralateral posterior striate cortex. Visual stimulation induced highly significant asymmetries in metabolism of the prefrontal and inferior parietal cortices. Metabolic activation in extrastriate areas tended to be right-sided. These findings support the classic notion of retinotopic organization within the primary visual sensory cortex. They also indicate that the patterns of cerebral metabolism are not equivalent between the two cerebral hemispheres. This latter finding suggests that in humans the right cerebral hemisphere may be specialized for visual processing.

Adolescent↗