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Biomedical subjects

M Burke

Publications and source records attributed to M Burke.

At least 379 records · Page 21Linked to original sources
PubMed1977

GLC determination for ftorafur in biological fluids.

A GLC analysis for free ftorafur was developed to follow in drug disposition in body fluids of patients. The free drug was extracted from aqueous biological samples with chloroform, derivatized by methylation, and chromatographed on 1% HI-EFF 8BP using flame-ionization detection. The analysis is sensitive (0.25 microgram/ml of plasma) and specific for the intact molecule, and it does not interfere with subsequent fluorouracil analysis of the same sample.

Chromatography, Gas↗
PubMed1977

A controlled trial of the impact of the family practice nurse on volume, quality, and cost of rural health services.

Rural Newfoundland communities with and without expanded role nurses were compared on a before and after basis. The rural communities are located in a geographically isolated area served by a 40-bed hospital staffed by salaried physicians. Primary care visits within the community increased by 186 per cent after establishment of the family practice nurse community clinic and attendance at the hospital decreased by 35 per cent. Acute care days in hospital decreased 5 per cent in the experimental group and increased by 39 per cent in the control group. A major portion of the community based visits provided to the experimental group were classed as preventive. The total annual health service cost per 1,000 persons in the experimental group increased slightly more than in the control group (26 versus 21 per cent). Adequate management of certain indicator conditions and drugs was maintained by the family practice nurse when compared to the adequacy rating for the physician during the same time period.

Community Health Nursing↗
PubMed1977

Intussusception in adults.

A brief résumé of the important principles of diagnosis and treatment of intussusception in adults is presented, with 3 illustrative case histories.

Aged↗
PubMed1976

Effect of bridging the two essential thiols of myosin on its spectral and actin-binding properties.

The circular dichroic and fluorescent spectral properties of the myosin head (subfragment I (SFI)) modified by covalently bridging the two essential thiol groups have been examined. CD spectra of SFI with the two thiols linked through reaction with a bifunctional reagent, N, N'- p-phenylenedimaleimide, show enhancement of the 282-nm minimum similar to that observed for the long-lived kinetic intermediate (Mg**MgADP-Pi) formed during the ATP cleavage reaction. No significant perturbation of the CD band at 282 nm is seen on blocking both thiol groups with the monofunctional reagent N-ethylmaleimide. The fluorescence emission maximum also shifts to lower wavelengths following covalent bridging (from 343 to 340 nm), but no change in fluorescent intensity has been detected. Formation of the covalent bridge completely inhibits interaction of the modified protein with F-actin. These results suggest that the local conformational state of the polypeptide chain formed on bridging the two thiol groups exhibits certain similarities with the state produced following binding of MgATP to native myosin.

Actins↗
PubMed1976

The effect of phenobarbital on patients with Dubin-Johnson syndrome.

11 patients with jaundice of Dubin-Johnson type were treated for 2 weeks with phenobarbital. Serum bilirubin diminished and hepatic clearance of sulfobromophthalein was variably enhanced; other measures of hepatic function were not significantly changed during therapy.

Adolescent↗
PubMed1975

An activation mechanism for ATP cleavage in muscle.

Evidence for a proposed activation mechanism is summarized. The low rate of ATP cleavage in the resting state of muscle is considered to result from the formation of a stable ring structure involving the two essential sulfhydryl groups on each myosin head and MgATP. Activation is thought to occur by interaction of actin in the vicinity of one of the essential sulfhydryl groups. Thus opening the stable ring leading to rapid dissociation of split products. This idea is consistent with the kinetic scheme of ATP cleavage developed recently by other workers and allows a prediction of the shift in population of intermediate states with changes in solvent conditions. It is also supported by our recent studies on the spatial geometry of the ring. The possibility that other nucleophilic groups may replace the sulfhydryl groups in other contractile systems is considered. The relevance of the ring structure to the tension generating event is discussed on the basis of recent measurements of the rate of contraction of modified (SH1-blocked) actomyosin threads. Results indicate the ability to form the ring structure is an essential requirement of the contractile process in these systems, and, moreover, that single, modified heads of myosin can act independently to produce the same rate of contraction as native myosin. This latter finding suggests that the myosin duplex exhibits some type of negative cooperativity in the contractile process.

Actins↗