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Biomedical subjects

J Devine

Publications and source records attributed to J Devine.

At least 37 records · Page 2Linked to original sources
PubMed1993

Effects of simulated high altitude exposure on long-latency event-related brain potentials and performance.

The N100, P200, N200 and P300 components of the auditory event-related potential were recorded from 10 male subjects at 0900, 1600, and 1830 hours at sea level and again following a rapid ascent to simulated 4300 m altitude. Amplitude and latency of components, ear oximetry, and concurrent performance measures (reaction time and counting errors) were assessed. Amplitude of P300 decreased, while P300 latency and reaction time increased, following ascent to altitude. However, the time course of altitude effects differed for amplitude versus latency. Components N100, P200, N200, and counting errors were unaffected by altitude. The results indicate that central measures of cognitive capacities are differentially sensitive to high altitude. The time course of altitude effects on P300 amplitude versus P300 latency suggests that the two measures reflect different aspects of a response to hypobaric hypoxia exposure.

Adult↗
PubMed1992

Evaluation of cochlear function in a patient with "far-advanced" otosclerosis.

A patient with "far-advanced" otosclerosis with a profound bilateral hearing loss was evaluated for cochlear reserve using transtympanic electrocochleography (ECoG) and promontory stimulation. Results indicated that both ECoG and promontory responses were present, indicating that cochlear function was present bilaterally. A stapedectomy resulted in closure of the air-bone gap. Postoperative hearing yielded excellent aided responses compared to no measurable preoperative hearing aid benefit. This case serves to demonstrate the value of evaluating cochlear function using these electrophysiologic techniques.

Aged↗
PubMed1992

Effect of high terrestrial altitude and supplemental oxygen on human performance and mood.

Sustained exposure to high terrestrial altitudes is associated with cognitive decrement, mood changes, and acute mountain sickness (AMS). Such impairment in aviators could be a safety hazard. Thirteen male soldiers, ages 19-24, ascended in 10 min from sea level to 4,300 m (simulated), and remained there 2.5 d. Four times per day, subjects completed a test battery consisting of nine cognitive tests, a mood scale, and an AMS questionnaire. During one test session per day, subjects breathed 35% oxygen instead of ambient air. Analysis revealed transient deficits on altitude day 1 for three cognitive tasks. Most tasks displayed a persistent training effect. Sick subjects' moods were more negative and their performance improvement less. On altitude day 1, oxygen administration improved performance on two cognitive tests and one mood subscale. Following rapid ascent to 4,300 m, performance is most affected during the first 8 h. Individuals affected by AMS tend to improve more slowly in performance and have more negative moods than those who feel well.

Adult↗
PubMed1990

Cloned GABA receptors are maintained in a stable cell line: allosteric and channel properties.

The cloned cDNAs encoding the alpha 1 and beta 1 subunits of the bovine brain GABA(A) receptor have been co-transfected, using a dexamethasone-inducible promoter, into cultured hamster ovary cells, with selection to form a stable cell line. The use, alternatively, of a much stronger constitutive promoter led to cell death consequent upon high receptor density. After induction, the cells contained the alpha 1 and beta 1 mRNAs. The expressed receptors showed the high-affinity binding of [3H]muscimol and of the GABA(A) receptor channel blocker, t-butylphosphorothionate (TBPS), and the characteristic enhancement of the former by a pregnanolone. Their GABA-activated current was potentiated by the barbiturate, pentobarbitone, was reversibly blocked by bicuculline and picrotoxin, but was not enhanced by benzodiazepines. In mouse spinal cord neurons GABA activates channel openings to at least four conductance states (45, 30, 19 and 12 pS) with the 30 pS state being the most frequently observed (main) state. However, the main state of the alpha 1/beta 1 GABA(A) receptor was the 19 pS state. The enhancement of GABA(A) receptor current by barbiturates wa due to prolongation of mean channel lifetime, whereas the reduction of GABA(A) receptor current by picrotoxin was due to reduction of channel opening frequency and mean channel lifetime. Stable cell lines containing subunit combinations of this receptor should provide a powerful tool for the elucidation of its channel features and control mechanisms.

Animals↗
PubMed1987

Expression in COS cells of a mouse-human chimaeric B72.3 antibody.

B72.3 is a mouse hybridoma cell-line secreting an IgG1 antibody which recognises an epitope on a tumour-associated antigen, TAG-72. This high molecular weight mucin-like molecule is found on a variety of human neoplasms, including colon, breast and ovarian carcinomas. Chimaeric immunoglobulin genes with the B72.3 specificity have been constructed by joining the mouse variable regions from cDNA clones to human genomic constant regions using recombinant DNA techniques. The chimaeric heavy and light chain immunoglobulin genes were placed under the control of a strong viral promoter, and co-transfected into COS-1 cells. SDS-PAGE analysis of the 35S-labelled products demonstrated that the transiently expressed antibodies were correctly synthesised and assembled. The specific binding characteristics of the parent B72.3 antibody were retained by the chimaeric antibody in an antigen-based ELISA. This system gave sufficiently high transient expression of the chimaeric antibody molecules to allow rapid physical and immunological characterisation of the engineered gene products.

Amino Acid Sequence↗
PubMed1987

Psychiatry and family medicine: the McMaster approach.

Family physicians may spend up to 50% of their time dealing with emotional problems but will refer less than 10% of these cases for psychiatric treatment. This paper describes an approach developed at McMaster University which emphasizes the importance of understanding the needs of family physicians and helping them make optimum use of available psychiatric services. Such an approach aims at increasing the comfort and expertise of family physicians in handling the problems they see on a regular basis, involving them actively in their patient's care after a referral, and offering relevant services that supplement those of the family physician, while monitoring and correcting problems that can arise when the two specialties work together. The implications that this has on the training of family medicine and psychiatry residents are discussed as well as ways in which continuing education can be provided for family physicians in community practice.

Education, Medical, Continuing↗
PubMed1987

Operation Everest II: Altitude decompression sickness during repeated altitude exposure.

The incidence of altitude decompression sickness (ADS) was studied in 23 altitude scientists during repeated altitude exposure to 15,000-29,000 ft (4572-8839 m) in a decompression chamber. Prior to each altitude exposure, a 30-60-mm pre-breathing period with 100% oxygen took place. Ascent was made to an altitude at a rate of 2000 ft X min-1. The altitudes studied ranged from 15,000-29,000 ft (4572-8839 m). Symptoms reported appear consistent with previous reports. Incidence of ADS at 26,000-29,000 ft (7925-8839 m) was 29.7%, during 274 chamber flights and 1264.6 h of altitude time. Incidence appeared related to frequency of exposure, severity of altitude, and physical activity. Incidence was not related to age, duration of exposure, or body index (weight/height 2). This high incidence of ADS reported in this study is similar to that reported by NASA.

Adult↗
PubMed1978

A rapid method for the presurgical cleansing of hands.

A new rapid method of presurgical cleansing of the hands has been evaluated in a clinical setting. The effectiveness of a 90 second jet wash has been compared with a standard 10-minute presurgical scrub. Bacteriologic cultures were obtained from the fingertips of interns, residents, and staff of the Department of Obstetrics and Gynecology of the Walter Reed Army Medical Center before and after 90-second jet washings and 10-minute conventional scrubs. The results showed that the 90-second jet wash was more effective in degerming the hands than the 10-minute standard brush scrub. Other advantages of the new method, such as the amount of time saved, the standardization of cleansing, and reduced skin irritation are discussed.

Antisepsis↗
PubMed1975

Pharmacology of some oral penicillins in the newborn infant.

Serum and urine concentrations of ampicillin, amoxycillin, and flucloxacillin achieved after oral administration have been measured in 27 newborn infants. Compared with adults and children, newborn infants show a delay in achieving adequate blood concentrations, presumably due to delayed absorption. However most infants achieve therapeutic concentrations in the serum. Infected newborn infants should be given these antibiotics by intramuscular injection for the first dose, but thereafter oral therapy (25 mg/lg every 6 hours begun concomitantly) should be satisfactory. The better absorption of amoxycillin compared with ampicillin reported in adults has not been confirmed in the newborn infant.

Administration, Oral↗