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Biomedical subjects

J K Cooper

Publications and source records attributed to J K Cooper.

At least 109 records · Page 6Linked to original sources
PubMed1977

GLC determination of plasma acenocoumarol levels.

A method for the quantitative estimation of acenocoumarol in plasma is described. Plasma containing acenocoumarol, to which a known amount of gamma-oxo derivative of phenylbutazone is added as an internal standard, is acidified and extracted with ethylene dichloride. The drug and the internal standard are then back-extracted into alkali, which, in turn, is acidified and reextracted with ethylene dichloride. The organic extract is evaporated and treated with an ethereal solution of diazomethane (100 microliter). The reacted mixture is evaporated, and the residue is dissolved in 25 microliter of carbon disulfide. Aliquots (2-3 microliter) are injected into a gas chromatograph equipped with a flame-ionization detector. The methyl derivatives of acenocoumarol and the internal standard give sharp, well-separated, symmetrical peaks. The method is of sufficient sensitivity to determine 0.25 microgram/ml of the drug in plasma with a relative standard deviation of 4%.

Acenocoumarol↗
PubMed1977

Identification of urinary catechol and methylated catechol metabolites of phenytoin in humans, monkeys, and dogs by GLC and GLC-mass spectrometry.

A catechol metabolite, 5-(3,4-dihydroxyphenyl)-5-phenylhydantoin, and a methylated catechol metabolite, 5-(3-methoxy-4-hydroxyphenyl)-5-phenylhydantoin, were identified as urinary metabolites in humans, monkeys, and dogs following the administration of phenytoin. These metabolites were separated from each other and from other known metabolites of phenytoin as n-butyl derivatives by GLC and positively identified by combined GLC-mass spectrometry.

Animals↗
PubMed1977

Affecting the supply of rural physicians.

A model describing physician supply and distribution is described. Two surveys obtained information to examine elements of the model. The first survey identified a group of primary care physicians that had considered rural locations but ultimately selected an urban location. This sub-group, 29 per cent of the primary care supply pool, received a follow-up survey to provide more information about how they made their choice. About one-half of them finally chose on the basis of factors other than metropolitan/non-metropolitan considerations. For this half, some of the factors that entered into the decision were the availability of physician specialists, nearby hospital facilities, and access to medical school programs. Such factors could be affected by future policy decisions, but the cost is unknown. Even if such policy decisions were made, and appropriate programs instituted, the results would probably not solve the problem of disproportionate physician distribution. The most likely-to-succeed approach to increasing the number of rural physicians remains that of increasing the number of entrants to medical school with a rural background.

Career Choice↗
PubMed1977

Where is the malpractice crisis taking us?

There have been several approaches taken to solve the malpractice insurance problem in this country. However, since the cost of malpractice insurance continues to climb, the changes so far have not solved the problem, and more changes seem inevitable. A major change could be the development of a patient insurance plan that would provide compensation for certain injuries related to medical care. The insurance coverage would be centered on hospital care. If certain requirements are met, the plan may not be more expensive than the current tort liability system, and would offer several advantages. In addition to the patient injury insurance, there could be federal assumption of liability for national immunization programs.

Costs and Cost Analysis↗
PubMed1976

Sweden's no-fault patient-injury insurance.

Sweden has introduced a nationwide nofault patient-injury compensation plan. The plan was not introduced because malpractice insurance costs were high, but because so few injured patients received compensation through the tort liability system. With certain exceptions, compensation is provided for loss that occurs as a result of injury related to hospitalization or medical care. The insurance plan has completed 12 months of operation. It total cost is less than 50 cents per citizen, and it is financed from general tax revenue. Sweden's experience can be projected to a population the size of the United States, and the results compared to United States malpractice liability figures. Such a comparison indicates a total number of awards greater than that of the United States, but a lower average amount per award.

Costs and Cost Analysis↗
PubMed1976

GLC identification and determination of 3,4-methylenedioxyamphetamine (MDA) from plasma and urine.

A GLC method for qualitative and quantitative determination of 3,4-methylenedioxyamphetamine in biological fluids is described. After extraction of the drug and the internal standard, 4-methoxyamphetamine, from plasma and urine, the solvent is evaporated and the residue is mixed with 20 mul of freshly distilled ether. Aliquots (1-2 mul) then are injected into the gas chromatograph. Both the drug and the internal standard give well-separated symmetrical peaks. Flame-ionization detection allows concentrations of 0.125 mug of 3,4-methylenedioxyamphetamine from plasma to be determined with a precision of 3.16%. The method is applicable to the estimation of 4-methoxyamphetamine, employing 3,4-methylenedioxyamphetamine as the internal standard. For identification purposes, various derivatives such as Schiff bases, isothiocyanates, trifluoroacetates, and heptafluorobutyrates of both compounds were formed following extraction from urine and their GLC behavior was investigated. Derivative formation was confirmed by GLC-mass spectrometry. Mass spectral data for these derivatives are presented.

Amphetamines↗
PubMed1976

GLC determination of plasma concentrations of phenprocoumon.

A GLC method for the quantitative estimation of phenprocoumon from plasma is described. Plasma containing phenprocoumon, to which a known amount of phenytoin is added as the internal standard, is acidified and extracted with ethylene dichloride. The drug and the internal standard are then back-extracted into alkali, which is acidified and reextracted with ethylene dichloride. The organic extract is evaporated, and the evaporated residue is mixed with 50 mul of trimethylanilinium hydroxide in methanol. Aliquots (1-2 mul) are injected into a gas chromatography equipped with a flame-ionization detector in which the injection port is held at 325 degrees. The methyl derivatives of phenprocoumon and the internal standard give sharp, well-separated, symmetrical peaks. The method is of sufficient sensitivity to determine 0.125 mug/ml of the drug in plasma with a coefficient of variation of 7%.

Alkylating Agents↗