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Biomedical subjects

G F Cooper

Publications and source records attributed to G F Cooper.

At least 55 records · Page 3Linked to original sources
PubMed1987

Synthesis and antiinflammatory and analgesic activity of 5-aroyl-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acids. The 6-substituted compounds.

5-Aroyl-6-substituted-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carbo xylic acids were synthesized and assayed for analgesic and antiinflammatory activity. Several of these compounds, notably the 5-(4-fluoro- and 4-chlorobenzoyl)-6-methyl derivatives 25 and 26 and the 5-(4-methyl-, 4-fluoro-, 4-chloro-, and 4-methoxybenzoyl)-6-chloro congeners 31-34 were of equal or greater potency than indomethacin as antiinflammatory and analgesic agents both in acute and chronic animal models.

Analgesia↗
PubMed1986

A diagnostic method that uses causal knowledge and linear programming in the application of Bayes' formula.

Bayes' formula has been applied extensively in computer-based medical diagnostic systems. One assumption that is often made in the application of the formula is that the findings in a case are conditionally independent. This assumption is often invalid and leads to inaccurate posterior probability assignments to the diagnostic hypotheses. This paper discusses a method for using causal knowledge to structure findings according to their probabilistic dependencies. An inference procedure is discussed which propagates probabilities within a network of causally related findings in order to calculate posterior probabilities of diagnostic hypotheses. A linear programming technique is described that bounds the values of the propagated probabilities subject to known probabilistic constraints.

Bayes Theorem↗
PubMed1986

The effect of regionalization upon the quality of trauma care as assessed by concurrent audit before and after institution of a trauma system: a preliminary report.

To assess the need for a trauma system in San Diego County, a concurrent audit of trauma care was performed by an independent consultant in 1982. During the study period from 15 March through 15 June 1982, 591 consecutive major trauma victims (MTV) were collected by the 30 participating hospitals. All medical records, including autopsy reports, were audited for the timeliness and appropriateness of diagnosis and definitive care. Deaths were classified as being not preventable, potentially salvageable, or preventable. A trauma system subsequently became functional on 1 August 1984, with five adult centers and one pediatric center. A Medical Audit Committee composed of physicians and nurses from designated and nondesignated hospitals was organized to perform a monthly concurrent audit of trauma care. Between 1 August and 31 December 1984, 1,366 MTV were triaged to trauma centers. The care of MTV was considered suboptimal in 32% of patients before regionalization, compared to 4.2% after regionalization (p less than 0.01). Preventable deaths occurred in 13.6% of fatalities occurring before implementation of a trauma system, compared to 2.7% after implementation (p less than 0.01). Regionalization of trauma care significantly reduced delays, inadequate care, and preventable deaths due to trauma.

Adolescent↗
PubMed1985

Synthesis and antiinflammatory and analgesic activity of 5-aroyl-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acids and related compounds.

5-Acyl-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acids and the homologous pyridine and azepine derivatives were synthesized and assayed for antiinflammatory and analgesic activity. 5-Benzoyl-1,2-dihydro-3H-pyrrolo-[1,2-a]pyrrole-1-carboxylic acid and the corresponding p-methoxy compound 74 were selected for evaluation as analgesic agents in humans on the basis of their high potency in the mouse phenylquinone writhing assay as well as on their minimal liability to elicit gastrointestinal erosion in rats on chronic administration. Extensive quantitative structure-activity relationship (QSAR) studies of the benzoylpyrrolopyrrolecarboxylic acids have demonstrated that the analgesic (mouse writhing) and antiinflammatory (rat carrageenan paw) potencies of these compounds are satisfactorily correlated with the steric and hydrogen-bonding properties of the benzoyl substituent(s). The 4-vinylbenzoyl compound 95, which was correctly predicted to be highly active in both assays on this basis, is undergoing advanced pharmacological evaluation in animals as a potential antiinflammatory agent.

Analgesics↗
PubMed1973

Carbon-13 nuclear magnetic resonance spectra of prostaglandins and some prostaglandin analogs.

High-resolution pulsed Fourier-transform nuclear magnetic resonance spectroscopy at 22.63 MHz was used to observe the proton-decoupled natural-abundance (13)C nuclear magnetic resonance spectra of CDCl(3) solutions of the methyl esters of prostaglandins F(1alpha), 15-epi-F(1alpha), F(2alpha), F(2beta), E(2), A(2), 13-dehydro-F(2alpha), 13-dehydro-F(3alpha), two intermediates on the synthetic pathway to 13-dehydro-PGF(3alpha), and of 7-oxa-PGF(1alpha). All resonances were assigned by chemical shift comparisons and single-frequency offresonance proton decoupling. With two exceptions, all the lines of the spectra are well-resolved single-carbon resonances. Those due to the cyclopentane and vinyl carbons are most sensitive to structural changes. Some of these effects can be rationalized in terms of the preferred conformations of the molecules.

Carbon Isotopes↗
PubMed1969

The spatial selectivity of the visual cells of the cat.

1. Micro-electrode recordings have been made from single units in the visual cortex of the cat, during stimulation by moving grating patterns generated on a cathode ray tube.2. The responses of the units have been measured in terms of either the frequency of impulses, or the contrast sensitivity, and expressed as a function of the spatial frequency of the grating pattern.3. The amplitude of the responses recorded from cortical cell bodies was dependent upon the orientation of the moving grating, and for these units the stimulus was always presented at the preferred orientation. The response amplitude of other units did not depend upon the orientation of the grating stimulus, and these are believed to be the terminations of geniculate fibres.4. The high spatial frequency end of the response function measured in terms of the contrast sensitivity could be well fitted by an exponential function. Subtraction of the blank count from the impulse frequency data gave a curve fitted by the same exponential function. The low frequency end was less consistent.5. The spatial frequency at which this exponential function had fallen by one log. unit was taken to specify the position of the unit's response in the spatial frequency spectrum. For all units these values cover a range of four octaves of spatial frequency (from 0.18 to 3.8 cycles per degree).6. It is suggested that these neurophysiological results support psychophysical evidence for the existence in the visual system of channels, each selectively sensitive to a narrow band of spatial frequencies.

Animals↗
PubMed1969

The yellow colour of the lens of the grey squirrel (sciurus carolinensis leucotis).

1. The absorption spectrum of the lens of the grey squirrel (Sciurus carolinensis leucotis) has been measured, revealing an absorption maximum at 370 nm. Peak densities in the intact lens ranged from 12 to 20.2. This peak is not present in the lenses of horse, cow, pig, dog, cat, ferret (Mustelo furo), or guinea-pig (Cavia porcellus).3. The pigment responsible for this absorption is water-soluble and aqueous extracts have been examined. Protein-free aqueous extracts show an additional maximum at 265 nm, which can only partially be accounted for by the presence of ascorbic acid.4. The absorption spectrum of extracts of lens material from the ground squirrel (Citellus mexicanus) also had maxima at 265 and 370 nm.5. Chromatography of the protein-free solution separated two yellow components, both of which had a yellow fluorescence. The faster component had a very similar absorption spectrum to the original protein-free solution.6. Possible functions of the yellow pigment are discussed.

Animals↗
PubMed1969

The yellow colour of the lens of man and other primates.

1. Measurements have been made of the absorption spectra of the lenses of human, baboon (Papio), rhesus monkey (Macaca), squirrel monkey (Saimiri sciureus) and bush baby (Galago crassicaudatus).2. In all these species an absorption maximum was found between 365 and 368 nm.3. The pigment responsible for this absorption was water-soluble and aqueous extracts were examined. Protein-free aqueous extracts showed an additional maximum at 260 nm which could be only partially accounted for by the presence of ascorbic acid.4. Chromatography of the protein-free solution from human lenses yielded a fast-moving yellow component with a blue fluorescence. Its absorption spectrum was very similar to that of the original protein-free solution. A fast-moving yellow component from the baboon lens had a yellow fluorescence.5. The human lenses appeared to contain more of the yellow, water-soluble pigment at birth than in adult life. The concentration remains constant during adult life.6. There is evidence for the appearance of another pigment in the human lens in later adult life. It is not water-soluble and has an absorption maximum at about 330 nm.

Adolescent↗
PubMed1968

The angular selectivity of visual cortical cells to moving gratings.

1. Grating patterns were used to obtain a quantitative description of cells in the visual cortex of the cat whose response amplitude depended critically upon the orientation of the moving grating.2. In all such cells the impulse frequency was found to decrease linearly with angle on either side of an optimum angle (the preferred angle) until the response fell to zero or to a base frequency. The angular rate of change of response varied between cells and was expressed as the half-width at half amplitude (the angular selectivity).3. The angular selectivity of thirty-five cells was determined and more than half (nineteen) of these fell within the range 14-26 degrees .4. Fourteen cells responded optimally only when the grating was moved in one direction. Twenty-one cells responded optimally to two directions of movement 180 degrees apart, but the response in the two directions was not always equal.5. No significant correlation was found between the response amplitude at the optimum angle and the angular selectivity.6. The distribution of preferred angles did not show any difference between the oblique orientations and the vertical and horizontal orientations.7. These results are compared with a previous psychophysical estimate of angular selectivity.

Journal Article↗