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Biomedical subjects

A Milne

Publications and source records attributed to A Milne.

At least 19 recordsLinked to original sources

ESPEN Guidelines on Enteral Nutrition: Geriatrics.

Nutritional intake is often compromised in elderly, multimorbid patients. Enteral nutrition (EN) by means of oral nutritional supplements (ONS) and tube feeding (TF) offers the possibility to increase or to insure nutrient intake in case of insufficient oral food intake. The present guideline is intended to give evidence-based recommendations for the use of ONS and TF in geriatric patients. It was developed by an interdisciplinary expert group in accordance with officially accepted standards and is based on all relevant publications since 1985. The guideline was discussed and accepted in a consensus conference. EN by means of ONS is recommended for geriatric patients at nutritional risk, in case of multimorbidity and frailty, and following orthopaedic-surgical procedures. In elderly people at risk of undernutrition ONS improve nutritional status and reduce mortality. After orthopaedic-surgery ONS reduce unfavourable outcome. TF is clearly indicated in patients with neurologic dysphagia. In contrast, TF is not indicated in final disease states, including final dementia, and in order to facilitate patient care. Altogether, it is strongly recommended not to wait until severe undernutrition has developed, but to start EN therapy early, as soon as a nutritional risk becomes apparent.

Aged↗

Cost-benefit analysis of the use of TBT: the case for a treatment approach.

The current climate of hostility towards the use of tributyltin (TBT) as an active ingredient in ship anti-fouling paint appears to be based on a very biased assessment of its environmental impact. While many national and international regulatory agencies are moving towards further restriction, and a complete ban is under active discussion, a number of factors appear to have been ignored. The economic impact of a ban on TBT when no adequate substitute exists could be substantial. Environmentally, consequences would include a substantial increase in the consumption of fossil fuel, with corresponding increases in carbon dioxide and sulphur dioxide emissions; the construction of more vessels; the transfer of ship-building, ship-repairing and ship-breaking activities from well-regulated to unregulated or under-regulated areas in the developing world; and a shift from sea transport to less environmentally acceptable forms of transport. Experience in Europe and other parts of the developed world shows that existing restrictions, where they are properly enforced, are probably adequate to alleviate the environmental damage associated with TBT. Some existing legislation acts to inhibit the search for effective substitutes. The environmental benefits of TBT have been ignored. Little thought has been given to a technical, rather than a legislative solution to controlling TBT inputs to the environment. A method is described for treating TBT-contaminated wastewaters, which has been successfully tested in prototype at full scale. Legislative measures against TBT will do nothing to address the problem of the existing backlog of contaminated material, nor even to permit the IMO proposal for the removal of TBT from all ships by 2008 to be successfully concluded in an environmentally safe manner, since no provision has been made for the disposal of the existing TBT; most probably it will be dumped in environmentally sensitive, unregulated areas in the developing world.

Cost-Benefit Analysis↗

Effect of mixing technique on the properties of acrylic bone-cement: a comparison of syringe and bowl mixing systems.

Syringe mixing systems have been introduced, but few data exist regarding the mechanical performance of cement they produce. We compared the properties of polymethyl methacrylate cement produced by these systems with that produced by a multiaxial bowl. Mixtures of cement were prepared using the Optivac, Cemvac, and Summit syringes and the Summit bowl. The mixtures were cured in molds to create casts that were radiographed and analyzed for void content, then cut into strips, weighed, measured, and tested to failure in 4-point bending. Syringe-mixed cement was of greater density, bending modulus, and bending strength than bowl-mixed cement (Mann-Whitney, P < .01) and contained fewer microvoids and macrovoids (Mann-Whitney, P < .01). No significant differences between the syringes were found for these variables (Kruskall-Wallis, P > .05).

Bone Cements↗

Clinical features, diagnosis and outcome of acute portal vein thrombosis.

The clinical features of acute portal vein thrombosis (APVT) are poorly defined in the literature. The proportion that progress to chronic PVT and the influences of various treatments are unknown. Between 1996 and 1998, nine patients presented to our hospital with varying upper gastrointestinal symptoms. They were found to have APVT by colour flow Doppler ultrasound, which was confirmed by CT scanning. All were tested for procoagulant tendencies and then treated with intravenous heparin for 7 days and warfarin for 3 months. Colour flow Doppler ultrasound or CT was done regularly to assess response to treatment. There was complete resolution of thrombus in five patients. Four patients had procoagulant tendencies identified; of these the thrombus resolved in two cases and in two cavernous transformation occurred. In most cases, the thrombus disperses on heparin and warfarin, although the effect of this therapy is unknown. A randomized trial of thrombolytic therapy may be appropriate, in an attempt to reduce the rate of progression to chronic PVT.

Acute Disease↗

Synthesis and serotonergic activity of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives: novel antagonists for the vascular 5-HT(1B)-like receptor.

The synthesis and vascular 5-HT(1B)-like receptor activity of a novel series of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives are described. Modifications to the 5-ethylene-linked heterocycle and to substituents on the 2-benzylamide side chain have been explored. Several compounds were identified which exhibited affinity at the vascular 5-HT(1B)-like receptor of pK(B) > 7.0, up to 100-fold selectivity over alpha(1)-adrenoceptor affinity and 5-HT(2A) receptor affinity, and which exhibited a favorable pharmacokinetic profile. N-Benzyl-3-[2-(dimethylamino)ethyl]-5-[2-(4,4-dimethyl-2, 5-dioxo-1-imidazolidinyl)ethyl]-1H-indole-2-carboxamide (23) was identified as a highly potent, silent (as judged by the inability of angiotensin II to unmask 5-HT(1B)-like receptor-mediated agonist activity in the rabbit femoral artery), and competitive vascular 5-HT(1B)-like receptor antagonist with a plasma elimination half-life of approximately 4 h in dog plasma and with good oral bioavailability. The selectivity of compounds from this series for the vascular 5-HT(1B)-like receptors over other receptor subtypes is discussed as well as a proposed mode of binding to the receptor pharmacophore. It has been proposed that the aromatic ring of the 2, N-benzylcarboxamide group can occupy an aromatic binding site rather than the indole ring. The resulting conformation allows an amine-binding site to be occupied by the ethylamine nitrogen and a hydrogen-bonding site to be occupied by one of the hydantoin carbonyls. The electronic nature of the 2,N-benzylcarboxamide aromatic group as well as the size of substituents on this aromatic group is crucial for producing potent and selective antagonists. The structural requirement on the 3-ethylamine side chain incorporating the protonatable nitrogen is achieved by the bulky 2, N-benzylcarboxamide group and its close proximity to the 3-side chain.

Animals↗

Inhalational and local anesthetics reduce tactile and thermal responses in mimosa pudica.

PURPOSE: In reaction to a variety of stimuli, the sensitive plant mimosa pudica closes its leaflets and drops its stems. The objective was to investigate the effects of anaesthetics on the reaction of mimosa pudica to a variety of stimuli. METHODS: The ability of the plants leaflets to close (n=4, Q5min.) was tested after exposure to halothane 4% and 6L x min(-1) O2, or 6L x min(-1) O2. Lidocaine 2% or vehicle were administered through the roots, cut stems, or sprayed on the leaves (n=4). The test consisted of stimulating the leaves, by burning their tips (lidocaine experiments) or touching them with a metal rod (halothane); the closing of the leaflets, or the lack thereof was then observed. RESULTS: After 15 min exposure to halothane, the mimosas had slow and incomplete reactions to tactile stimulation. Following 20 min exposure, the plants had no visible reaction to touch, a stimulus which would normally cause the collapse of the entire leaf. After one minute, mimosa leaves sprayed with lidocaine had no reaction to a lit match being touched to the tips of the leaves, contrary to the control in which the leaves collapsed completely. After exposure to lidocaine 2% through the roots and cut stems, the mimosa's reactivity gradually decreased; after four hours the leaves were insensitive or had slow reaction to tactile stimuli. CONCLUSIONS: Inhalational and local anesthetics inhibited motor mechanisms of the mimosa plant. This may be a model to elucidate the mechanisms of action of anesthetics.

Anesthetics, Inhalation↗

Experimental tests of prospective remembering: the influence of cue-event frequency on performance.

During recent years there has been an upsurge of interest in the processes underlying success or failure of intentions to perform an action in the future e.g. carry out an errand for a friend. Much of this research focuses on simulating these delayed-intention or prospective-memory tasks in the laboratory. A currently popular variant of these tasks is a repeated-instance event-based one in which the same action should be performed whenever a particular (repeated) event-cue occurs during an ongoing activity (e.g. a word in a running memory test of word recall). We report two experiments that investigated important dimensions of this task design, along which recent experimental tasks differ considerably, and explored their influence on prospective remembering. The results revealed that the variations in the event-cue frequencies explored here did not influence overall performance: relatively high event-cue frequency did not improve prospective remembering. However, performance was lower when event-cues were embedded in a general knowledge test than when a prose-reading task was used. Moreover, when remembering was compared for the first and final set of event-cues there was evidence for improvement over presentations during the general knowledge task and a contrasting decline using the prose task, under high event-cue frequency conditions only. The results have important repercussions for current experimental design and the development of tests of prospective remembering skills in particular population subgroups.

Adult↗

Phenomenal causality: impressions of pulling in the visual perception of objects in motion.

Subjects observed computer-generated images of the five opaque rectangles arranged in a vertical column and separated by small gaps. In order from top to bottom, the rectangles began to move horizontally at intervals of a fraction of a second, at constant and identical speeds. Subjects reported a strong impression that the top object was pulling the others, despite the fact that the objects never came into contact or approached each other, moved in different planes, and had no visible connection. The impression was not much affected by speed, direction of motion, or length of delay between successive objects beginning to move. The effect was attenuated if there was prior motion in the opposite direction, if each object in turn rapidly decelerated to standstill, and if all objects began to move simultaneously. It is unlikely that this impression could be mediated by an innate visual mechanism, and it may reflect perceptual learning.

Adolescent↗

Hepatitis B infection in households of HBsAg positive New Zealand children.

AIMS: To determine, from data obtained in a school-based hepatitis B vaccination programme, the prevalence of hepatitis B virus (HBV) infection in household contacts of children found to be hepatitis B surface antigen (HBsAg) positive. METHODS: Children who were HBsAg positive were visited in their homes 6 months or more after their initial blood test. Blood was drawn to confirm HBsAg status, and to ascertain HBeAg status. Their household contacts were tested for HBV seromarkers. RESULTS: Visits were made to homes of 931 children initially found to be HBsAg positive. Nine hundred and seven of these children (97.4%) were still HBsAg positive and thus confirmed to be chronic HBsAg carriers. The testing of 2957 household contacts of HBsAg positive schoolchildren revealed that 719 (24.3%) were HBsAg positive, a rate many times higher than that in the schoolchildren initially tested. Total HBV seromarker rates were highest in Asian households, and lowest in Europeans where 57% had been infected and 12% were HBsAg positive. Ethnic differences were largely accounted for by variation in maternal HBsAg status, reflecting different rates of perinatal infection. CONCLUSIONS: All family and household contacts of individuals identified as presumptive HBsAg carriers should be tested for HBV seromarkers as a routine. It is particularly important to ensure full prophylaxis against perinatal infection.

Adolescent↗

Establishing a postgraduate qualification in remote health care.

The British Antarctic Survey (BAS) provides medical care for the scientists and support staff working on British scientific bases and research vessels in the Antarctic. The BAS directs significant resources towards medical research, so a doctor who does not complete the research component of the programme of training and medical duties represents a partially wasted investment. Additionally, the professional experience gained by the doctor is appropriate for a postgraduate qualification. For these reasons, the training, clinical placement and research undertaken by doctors were formalized as a masters degree in 1992. The objectives of the MSc degree were to optimize the benefits of the training and research for Antarctic doctors and their patients, and to improve the quality of the research output. In the three years before the degree was introduced, only 25% of doctors produced a useful research output. Following the introduction of the MSc, this figure rose to 88%.

Antarctic Regions↗

Fletcher Challenge-University of Auckland Heart & Health Study: design and baseline findings.

AIMS: The aims of this prospective observational study are to determine the relationship of sociodemographic factors, psychological factors and several factors measured in blood, with the risk of coronary heart disease (CHD) in a New Zealand population. METHODS: Participants were recruited from two sources: employees of the Fletcher Challenge Group and individuals listed on the general electoral roll for the Auckland region. Baseline and follow up risk factor data were obtained from a questionnaire, blood samples and a simple physical examination. Outcome data on deaths and hospitalisations due to coronary heart disease will be obtained primarily through linkage of participant identifiers to data collected nationally by the New Zealand Health Information Service. RESULTS: A total of 10,529 individuals agreed to participate (8011 from Fletcher Challenge and 2518 from the electoral roll), representing a response rate of 74%. Within the study population, there was a broad distribution of sociodemographic characteristics including ethnicity-10% of participants were Maori and 5% were of Pacific Islands origin. There was also wide heterogeneity of coronary heart disease risk as judged from the distributions of established risk factors at baseline-5% of participants had evidence of existing coronary heart disease, a quarter were current smokers, a sixth were nondrinkers, almost a half were overweight, a fifth had blood pressure > or = 150/95 mmHg or were receiving antihypertensive treatment and a sixth had cholesterol levels > or = 6.5 mmol/L. CONCLUSIONS: This is the first, large scale prospective observational study of the determinants of coronary heart disease in a New Zealand population. The study participants represent a broad cross section of society, with wide variation in sociodemographic characteristics and coronary heart disease risk. Initial results concerning the relationships of primary interest should be available within 5 years when sufficient coronary heart disease events have been documented to allow reliable analyses.

Adult↗

Interleukin-1 activates p54 mitogen-activated protein (MAP) kinase/stress-activated protein kinase by a pathway that is independent of p21ras, Raf-1, and MAP kinase kinase.

In KB epidermoid cells, we previously showed that interleukin-1 alpha (IL-1) and various mitogens activate the mitogen-activated protein (MAP) kinases ERK1 and ERK2, which phosphorylate both myelin basic protein (MBP) and a peptide containing Thr669 of the epidermal growth factor receptor. In cell-free extracts made from gingival fibroblasts treated with platelet-derived growth factor or HepG2 hepatoma cells stimulated with phorbol myristate acetate, MBP and Thr669 kinase were both elevated 4-fold, and ERK1 and ERK2 were tyrosine-phosphorylated. In these cells IL-1 activated a kinase(s) that phosphorylated Thr669 peptide but not MBP and failed to cause tyrosine phosphorylation of ERK1/ERK2. Ceramide has been proposed as an intracellular mediator of IL-1 action, but C2-ceramide or sphingosine stimulated predominantly MBP-specific kinase activity in fibroblasts and had no effect in HepG2 cells. p54 MAP kinase (also called stress-activated protein kinase) is a c-Jun kinase first isolated from livers of cycloheximide-treated rats. After IL-1 stimulation, immunoprecipitates of lysates made from all three cell types with specific anti-p54 MAP kinase serum contained Thr669 and c-Jun phosphorylating activity, whereas precipitates from unstimulated cells contained no detectable p54 kinase activity. The major peak of IL-1-stimulated HepG2 Thr669 kinase activity co-chromatographed on Mono Q and phenyl-Superose with immunodetectable p54 MAP kinase. IL-1 did not cause p21ras activation in any cell type. Induction of Thr 669 kinase activity was not abrogated by elevation of cAMP levels, which has been shown to interfere with the activation of Raf-1. We could not detect MAP kinase kinase phosphorylating activity in unfractionated lysates made from IL-1-stimulated fibroblasts or HepG2 cells. KB cells contained a small amount of this activity, but it was not precipitated with an anti-Raf-1 antibody. We conclude that most of the IL-1-activated Thr669 kinase activity in fibroblasts and HepG2 cells, and a portion in KB cells, is due to p54 MAP kinase and that its activation is Ras-, Raf-, and MAP kinase kinase-independent.

Calcium-Calmodulin-Dependent Protein Kinases↗

Kawerau revisited: hepatitis A and B seroprevalence in 1984 and 1993.

AIMS: To determine if protection against hepatitis B is maintained in a cohort of children nine years after primary vaccination; To compare the prevalence of hepatitis B infection in 1984, before the introduction of hepatitis B vaccine, with that in 1993; To compare the prevalence of hepatitis A antibody (anti-HAV) in children in 1984 and 1993. METHODS: Serum samples collected from children attending Kawerau Intermediate School in 1993 were tested for hepatitis B markers and anti-HAV, and the results were compared with those in children attending the same school in 1984. RESULTS: Antibody to hepatitis B surface antigen (anti-HBs) was detected in 91.8% of children documented to have received hepatitis B vaccine in 1984. Seroconversion for antibody to hepatitis B core antigen (anti-HBc) had occurred in 5%. None had suffered a clinical illness. No vaccinee had a positive test for hepatitis B surface antigen (HBsAg). The prevalence of hepatitis B infection had fallen from 71.7% in 1984 to 24.2% in 1993. The prevalence of hepatitis A was 29.6% in 1984 and 0.4% in 1993. CONCLUSIONS: Protection against clinical disease and chronic hepatitis B infection is maintained nine years after primary vaccination. Hepatitis A has virtually disappeared among children in Kawerau.

Adolescent↗