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Biomedical subjects

J A Reid

Publications and source records attributed to J A Reid.

At least 55 records · Page 3Linked to original sources
PubMed1988

Extradural bupivacaine or lignocaine anaesthesia for elective caesarean section: the role of maternal posture.

Extradural anaesthesia was induced in 64 patients in either the sitting or the lateral position, for elective Caesarean section with either 0.5% plain bupivacaine or 2% lignocaine with adrenaline 1 in 200,000. Onset was significantly shorter and a significantly greater number of patients were ready for surgery within 35 min following injection of lignocaine in the lateral position. Hypotension (defined as a 25% or greater reduction in arterial pressure) occurred in 36% of patients. Significantly more patients who had received the first injection of local anaesthetic agent in the sitting position required ephedrine to correct maternal hypotension. Most frequently, hypotension coincided with transfer of patients to theatre and thus was associated with movement of the patient in the presence of extensive sympathetic block.

Adult↗
PubMed1987

Evaluation of closed-loop control of arterial pressure after cardiopulmonary bypass.

A closed loop computer system has been developed to deliver sodium nitroprusside (by infusion) to control systolic arterial pressure (SAP) after cardiopulmonary bypass. The performance of the closed-loop control system was evaluated by comparing nurse and computer control of SAP in 60 patients during the early postoperative period. The computer system provided better control of SAP than manual control by a member of the nursing staff.

Blood Pressure Determination↗
PubMed1986

Water safety.

Explore the source record for details and available documents.

Humans↗
PubMed1984

A clinical trial of a rare earth screen/film system in a periapical cassette.

In a clinical trial, a slow rare earth screen/film system (Siemens Titan 2D/Kodak XG) was used to obtain intraoral radiographs at conventional monitoring stages in endodontic treatment. The screen film image proved to be an effective substitute for the direct-exposure Ultraspeed periapical film. The intraoral cassettes, designed and fabricated for the study, were an adaptation of the flexible, vacuum-sealed cassettes used in mammography. It is believed that when a practicable periapical cassette is manufactured, many additional indications for the system are probable. Major reductions in patient exposure of at least 85% to 90% per periapical film would be effected.

Equipment Design↗
PubMed1984

Use and workload factors in dental radiation-protection design.

A dosimetric and photographic record of the pattern of radiation on the walls of a dental x-ray operatory was obtained. This indicates that there is an overlap of the radiation fields with "hot spots" on the side wall opposite the patient's head, with the rest of the room receiving minimal exposures. In the course of this investigation, it was found that use of the long-cone x-ray machine resulted in less radiation reaching the walls of the room. The presently accepted concept of mAs per week proves to be less relevant than the number of films being taken.

Equipment Design↗
PubMed1983

Drywall construction as a dental radiation barrier.

Six typical forms of drywall construction have been tested as barriers against primary and secondary dental x-radiation. It is concluded that this widely used type of wall construction is generally effective for this purpose, but with a heavy workload two thicknesses of wallboard on each side of the wall are required to provide a sufficient barrier. In general, no lead need be incorporated in the walls.

Construction Materials↗
PubMed1983

Technetium and uranium: sorption by and plant uptake from peat and sand.

The objectives of this study were to compare the effects of technetium and uranium on the yield and uptake, and to identify the organ of accumulation, of an edible leafy vegetable growing in sandy and peaty soils. In sand, where the soil's sorption capacity is negligible, technetium uptake is four orders of magnitude higher than from peat, suggesting no plant mediation of uptake and thus a constant concentration factor (greater than 50) in an oxidizing environment where technetium is continuously supplied. The technetium is predominantly translocated to the shoots. When soil fixation occurs, as in peat, this becomes the controlling factor in the plant uptake of technetium. In the case of uranium, plant mediation is more significant. Uranium uptake by Swiss chard is up to 80 times higher from sand than from peat. The uranium is restricted to the root system and may only be precipitated on the outer root membrane and may not accumulate in the roots.

Plants, Edible↗
PubMed1982

An investigation of potential applications of intensifying screens in intraoral radiography.

In medicine, the somewhat degraded image from the screen/film system is accepted for most diagnostic purposes in the interest of radiation thrift. In dentistry, however, the superb image resolution and sharpness of the radiation-intensive, direct-exposure film is the standard for intraoral radiography. There may be occasions in dental practice where such quality is not necessary, thus making the high level of exposure difficult to justify. In a laboratory study, screen-type radiographs were effectively substituted for ultraspeed film in the monitoring stages of endodontic therapy and as posttreatment films in operative dentistry. Even with a slow system, the radiation exposure was one sixteenth of the usual periapical dose. If clinical trials support these conclusions, only the lack of a practical periapical cassette limits the application of this significant method of radiation reduction to dental practice.

Dental Restoration, Permanent↗
PubMed1982

Angiotensin-converting enzyme inhibitors: importance of the amide carbonyl of mercaptoacyl amino acids for hydrogen bonding to the enzyme.

A series of mercaptoacyl amino acids and related compounds was synthesized and evaluated for inhibition of angiotensin-converting enzyme (ACE) in order to determine the nature and importance of the putative interaction between ACE and the amide moiety of inhibitors such as captopril (3-mercapto-2-methylpropanoyl-L-proline). It was concluded that the interaction involves a hydrogen bond from a donor site on ACE to the oxygen of the amide carbonyl. Compounds in which the amide moiety is replaced by other groups (ester, ketone, sulfonamide) capable of accepting a hydrogen bond are effective inhibitors, but compounds in which only the geometrical features of the amide are retained are ineffective inhibitors. The presence of an NH group is not necessary for effective inhibition. The activity of a series of mercaptoacyl cycloalkyl carboxylic acids parallels the activity of the isosteric series of mercaptoacyl imino acids.

Amino Acids, Sulfur↗