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Biomedical subjects

E Scott

Publications and source records attributed to E Scott.

At least 127 records · Page 7Linked to original sources
PubMed1968

"I had a dream".

Explore the source record for details and available documents.

Health Education↗
PubMed1966

Urease activity in blue-green algae.

The apparent enzymatic hydrolysis of urea has been detected in whole blue-green algae and in cell extracts. Urease is present as an intracellullar component in cultures in which no bacterial contaminants are found. The activity in the cells was recovered from the extracts.

Ammonia↗
PubMedDate not supplied

Development and operation of a program to obtain volunteer bone marrow donors unrelated to the patient.

Because of recent increases in bone marrow transplantation, the lack of available matched sibling donors has become a problem. This study investigated the feasibility of obtaining volunteer bone marrow donors unrelated to the patient. A program was developed to inform potential donors and obtain their consent for listing in a bone marrow donor registry. Sixty-six percent of whole blood or apheresis donors agreed to participate in the program. There were no demographic differences between those who accepted or declined to participate. Religion, experiences with medical practices, and the attitude of the potential donor's spouse were important factors in the decision to participate. A search for donors was initiated for 127 patients. Thirty searches were not completed, primarily because of patient-related problems. A total of 713 HLA-A and -B antigen-identical donors was located for 63 of the 97 (65%) patients. A total of 40 HLA-A, -B, and -DR antigen-identical donors was located for 18 of these 63 patients. Six of these 18 patients then had one or more donors (total, 9) whose lymphocytes did not react in mixed lymphocyte culture. Thus, using the file of 2147 donors, an HLA-identical donor was located for 6 percent of the 97 patients. None of these patients has yet received a transplant; in four cases this was due to patient-related and in two cases donor-related reasons. The cost to establish the donor program averaged $33.46 (1984) per donor for donors already typed for HLA-A and -B antigens. This experience indicated that, given thorough information about bone marrow donation and transplantation, a majority of blood and apheresis donors will volunteer to donate bone marrow, without feeling pressure to do so. A relatively small donor file provided donors for 6 percent of patients. The long-term value of bone marrow transplantation using unrelated donors and the optimum size of the donor file remain to be established.

Adult↗
PubMedDate not supplied

A dynamic two-dimensional phantom for ultrasound hyperthermia controller testing.

A new thin layer phantom for testing hyperthermia controllers has been constructed and evaluated using an ultrasound hyperthermia system. The phantom's thermal behaviour agrees with the characteristics of the Pennes' bio-heat transfer equation (BHTE). In particular, the experimental and theoretical results agree in the following ways. First, with respect to the power deposition: for a given power magnitude and scan radius, the shape of the temperature distribution across the phantom corresponds to the shape predicted by the BHTE and the experimental and theoretical temperature values agree closely; when the power magnitude is varied at a fixed scan radius, the average temperature of the phantom varies linearly with the applied power, and as the scan radius is varied at a fixed power magnitude, the average temperature increases with decreasing scan radius size. Secondly, with respect to perfusion: increasing or decreasing the flow rate over the phantom simulates an increase or decrease in the BHTE perfusion term, and the estimated perfusion values are dependent on flow rate only, and are not functions of power or geometry. The combination of these experimental and theoretical results validate the phantom's potential for testing feedback control systems, particularly for future use in the development and verification of model-based controllers. The use of this phantom should improve and accelerate the testing and evaluation of feedback control systems, and reduce the need for animal and human testing.

Animals↗
PubMedDate not supplied

Effects of insulin on coronary blood flow in anesthetized pigs.

Insulin can influence the vasculature by a sympathetically mediated vasoconstriction and a vasodilatation; the latter effect predominates in the renal circulation of anesthetized pigs. We determined the effect of intravenous infusion of insulin on coronary blood flow in pentobarbitone-anesthetized pigs at constant heart rate, arterial pressure and blood levels of glucose and potassium. In 6 pigs, infusion of 0.004 IU kg(-1) min(-1) of insulin decreased coronary flow despite increasing left ventricular dP dT(max)(-1); when the latter was abolished by propranolol, the coronary flow response was augmented. The mechanisms of this response were examined in 22 pigs given propranolol. Phentolamine changed coronary flow response to an increase (6 pigs) and this was abolished by intracoronary injection of N(omega)-nitro-L-arginine methyl ester (L-NAME; 5 pigs). L-NAME augmented coronary flow response (6 pigs) and this was abolished by phentolamine (5 pigs). In 18 pigs given propranolol, three incremental doses of insulin caused graded coronary flow decreases whether L-NAME was given (6 pigs) or not (6 pigs) beforehand, and caused graded coronary flow increases after phentolamine (6 pigs). Thus insulin caused a coronary vasoconstriction mediated by sympathetic alpha-adrenergic effects and a vasodilatation related to the release of nitric oxide. The net effect was a coronary vasoconstriction.

Adrenergic alpha-Antagonists↗