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M Brett

Publications and source records attributed to M Brett.

At least 37 records · Page 2Linked to original sources
PubMed1995

Classical conditioning in patients with Alzheimer's disease: a multiday study.

Previous studies demonstrated that patients with Alzheimer's disease (AD) do not acquire the classically conditioned eyeblink response. These studies, however, were only tested over a single conditioning session and, hence, raise the question of whether AD patients are capable of acquiring the response if sufficient training is given. This question may be of some importance whether AD patients can ultimately acquire the response has implications for the underlying neurobiological deficit in disrupted conditioning in AD. This study tested AD patients and age-matched controls over 4 days. As in previous studies, AD patients performed significantly worse than controls on Day 1, but by Day 4, they were not significantly different from controls. Subsequent testing indicated that these effects were not due to nonassociative variables such as changes in sensitivity to stimuli or disruption of the motor response. Also, it was reported that neither AD patients nor controls showed any evidence of acquisition in an explicitly unpaired paradigm, suggesting that neither pseudoconditioning nor sensitization is contributory. Data are discussed in terms of the possible role of the hippocampus in mediating conditioning deficits in AD patients.

Aged↗
PubMed1995

Designing a common core curriculum for operating department nursing.

This paper has been written to outline the experiences of the European Operating Room Nurses Association in designing a Common Core Curriculum for European Operating Room Nursing. The process of curriculum planning is never one to be undertaken without an understanding of the complexity of producing what often appears as nothing more than a simple document once the task is completed. In most situations the planning of a curriculum is undertaken by a small team of people who prepare a structure and content which they themselves are actually going to implement, therefore the curriculum responds to the needs of the particular location for which it is intended. When a National Curriculum is developed it is usually done so by a group of people who work within the framework and guidelines of a national body, but they include local representatives from different areas to ensure that the finished product is one which can usefully be applied to all areas of the country. The designing of a curriculum for Europe brings a whole new dimension to curriculum planning.

Curriculum↗
PubMed1993

Methicillin resistant Staphylococcus aureus (MRSA) in New Zealand 1988-90.

AIMS: To survey methicillin-resistant Staphylococcus aureus (MRSA) in New Zealand during the three years 1988-90. METHODS: Isolates and accompanying epidemiological data referred and reported to the New Zealand Communicable Disease Centre were analysed. RESULTS: MRSA was isolated from 255 persons, 235 patients and 20 healthcare staff, over the three years. The majority (84%) of persons were, or were recent, hospital patients or staff. Among hospital patients, males and patients aged 0 to 14 years were more likely to have MRSA. While most (88%) of the 145 strains identified occurred sporadically, three caused large outbreaks each involving more than 20 people. A third of the strains originated overseas, most commonly Australia or one of the Pacific Islands. The rate of MRSA isolation was higher in the North Island than the South Island. Two-thirds of the MRSA had only a low level of methicillin resistance and were not multiresistant. CONCLUSIONS: MRSA continues to be isolated only infrequently in New Zealand and has not become endemic in our hospitals.

Adolescent↗
PubMed1993

Exercise-related potassium and free fatty acid level changes in coronary artery disease. Responses after moderate intensity training.

Exercise produces changes in circulating levels of potassium and free fatty acids which may provoke arrhythmias in patients with coronary artery disease. Twenty patients participating in 6 weeks of training were studied; 9 of these patients took part in 4 more weeks of training and a third exercise test. After 6 weeks, potassium levels were higher at submaximal levels of exercise, free fatty acid levels were reduced at rest, and at 5, 15, and at 30 min post-exercise. Norepinephrine levels were reduced at submaximal work loads after 6 weeks and increased at maximal work loads. The extra 4 weeks had no additive effect on these metabolic changes. Participation by coronary artery disease patients in a short-term, moderate intensity, exercise training program increases potassium levels at submaximal work loads and reduces levels of free fatty acids at rest and after exercise. The arrhythmogenic relevance of these findings deserves further consideration.

Aged↗
PubMed1991

Treatment of recurrent urethral strictures using clean intermittent self-catheterisation.

The treatment of urethral strictures has been greatly improved by the use of the optical urethrotome. However, there remains a group of patients with recurrent strictures for whom the alternatives remain long-term dilatation/urethrotomy or urethroplasty. Over the last 3 years we have treated 65 such patients using clean intermittent self-catheterisation as a method of self-dilatation. This has resulted in a dramatic decrease in the number of operations performed on these patients, with no significant reduction in urinary flow rate over an average follow-up period of 20 months. The method offers the possibility of long-term cure and should be offered to all all such patients, reducing still further the number of patients who require urethroplasty.

Adolescent↗
PubMed1984

The structure of mammalian rod opsins.

Ovine rhodopsin is organised in disc membranes as a monomer. The determination of its amino acid sequence has permitted the utilisation of structure prediction programmes which indicate the probable disposition of the polypeptide chain in the bilayer. This putative model is consistent with labelling data using the chemical probes, [14C]succinic anhydride, [125I]diazodiido sulphanilic acid and [125I]iodophenyl azide, and with the cleavage points for several proteases. More surprisingly the predicted structure points to the occurrence of breaks/distortions in the transmembrane helical segments. These distorted regions may be of primary functional importance to the protein and at least one is associated with the attachment point of the chromophore. This particular part of the structure is also identified as a "mutational hot spot", for bovine, equine, ovine and porcine opsins exhibit different sequences (but conserved molecular volumes) in the four residues following the retinyllysine. In an otherwise highly conserved protein with no obvious functional differences between the four species, the high substitution rate in this region is unexplained.

Amino Acid Sequence↗
PubMed1983

Isolation and characterization of the CNBr peptides from the proteolytically derived N-terminal fragment of ovine opsin.

Ovine rhodopsin may be cleaved in situ by Staphylococcus aureus V8 proteinase into two membrane-bound fragments designated V8-L (27 000 mol.wt.) and V8-S (12 000 mol.wt.). After purification of the proteolysed complex by affinity chromatography in detergent using concanavalin A immobilized on Sepharose 4B, the two polypeptide fragments may be separated by gel-permeation chromatography on Sephadex LH-60. Digestion of the N-terminal-derived V8-L fragment with CNBr in 70% (v/v) trifluoroacetic acid resulted in a peptide mixture that could be fractionated by procedures involving gel-permeation chromatography in organic and aqueous solvents and the use of differential solubility. The complete or partial sequences of all ten peptides are reported.

Amino Acid Sequence↗
PubMed1979

Investigation of the organization of rhodopsin in the sheep photoreceptor membrane by using cross-linking reagents.

The organization of rhodopsin in the photoreceptor membrane of sheep rod outer segments was investigated by using a variety of bifunctional reagents. Of the nine reagents used, seven gave oligomeric opsin species, whereas two, copper phenanthroline and dithiobisphenyl azide, failed to cross-link the protein. In general, the cross-linked species obtained showed diminishing yields from dimer to tetramer, together with some higher-molecular-weight aggregates. It is proposed that the patterns of cross-linking arise as a result of collision complexes and best describe a monomeric organization for native rhodopsin. No significant differences between the patterns obtained with dark-adapted bleached or regenerated protein states were observed. This interpretation is discussed in relation to the postulated mechanism of action of rhodopsin.

Animals↗
PubMed1977

Amino acid replacements resulting from suppression and missense reversion of a chain-terminator mutation in Neurospora.

The Neurospora crassa super-suppressor mutation, ssu-1, suppresses the auxotrophic phenotype of the mutant am(17) by inserting tyrosine at residue 313 of NADP-specific glutamate dehydrogenase, a position occupied in the wild type by glutamate. Two classes of am(17) revertants due to further mutation within the am gene have, respectively, tyrosine and leucine at residue 313. These replacements are consistent with a chain-terminating codon in am(17) of either the amber (UAG) or the ochre type (UAA), but are inconsistent with UGA. The Leu313 and Tyr313 variants of the enzyme have effective activity but are grossly different from the wild type in Michaelis constants (especially for ammonium) and heat stabilities at two different pH values. They show smaller but significant differences in these respects from each other.

Amino Acid Sequence↗
PubMed1976

The world distribution of gallstones.

This paper presents two maps summarising all available published data on the world distribution of gallstones as recorded from autopsy studies. It is suggested that further autopsy studies are required, especially in Asia, Russia, the Middle Eastern and Mediterranean countries and South America. Such studies could be readily carried out and would contribute to our understanding of the aetiology of gallstones.

Adolescent↗