Biomedical subjects

L M Burke

Publications and source records attributed to L M Burke.

At least 19 recordsLinked to original sources

PubMed1998

Nutritional practices of elite female surfers during training and competition.

The aim of this study was to assess the dietary practices of 10 elite female surfers. Four- and five-day food diaries completed over competition and training periods demonstrated energy intakes (mean +/- SD) of 9,468 kJ (+/- 2,007) and 8,397 kJ (+/- 1,831), respectively. This level of energy intake was less than that estimated for the requirements of surfing. Female surfers' carbohydrate intakes failed to meet the recommendations, and suboptimal zinc intake was observed with 90% of subjects not meeting the Australian RDI. Comparisons between competition and training demonstrated that carbohydrate (g and g/kg body weight) and confectionary (g) intakes were significantly higher (p < .05) and protein intake was significantly lower (p < .05) during competition. These results show that although body fat stores were not compromised (mean 22%), self-reported energy, carbohydrate, and nutrient intakes were marginal in elite female surfers. Questionnaires revealed that 90% of surfers did not have good nutritional habits while traveling, which was compounded by a lack of knowledge of nutritional practices.

Adult↗

PubMed1997

FHIT mutations in human primary gastric cancer.

Allelic deletion of multiple regions on the short arm of chromosome 3 (3p) implies the presence of multiple important tumor suppressor genes in human carcinogenesis. The FHIT gene, identified recently in chromosome 3p14.2, shows frequent allelic deletion and aberrant transcripts in gastrointestinal tumors. After determining the intron sequences flanking each of the coding exons of the FHIT gene and designing intron primers to facilitate mutation analysis of genomic DNA samples, we analyzed the complete coding sequences in matched cancer and normal tissues from 40 cases with primary gastric cancer using intron primers, PCR-single-strand conformation polymorphism analysis, and direct sequencing. A somatic missense mutation in exon 6, codon 61, ACG (threonine) --> ATG (methionine) was found in a signet ring cell adenocarcinoma. We also evaluated allelic deletion in these tumors by PCR-based microsatellite analysis; allelic deletion occurred in 42.1% (16 of 38) of evaluable cases. This is the first report of a somatic missense mutation of the FHIT gene in a primary tumor. Presence of a point mutation and frequent allelic deletions are consistent with the hypothesis that FHIT gene alterations are involved in the development of primary gastric cancers.

Acid Anhydride Hydrolases↗

PubMed1997

Teachers of nursing--presenting a new model of practice.

In this paper a new model of practice for nurse teachers is presented. In this model the teacher is identified as an advanced practitioner of nursing but, as an advanced practitioner who specializes in education-in all contexts and across all environments where education and training are taking place. It is also a model of practice-based education which is negotiated, balanced and neither dominated by service or by education, it can be seen as responding to the demands of service and higher education, but not dictated by them. It emphasizes the importance of clinical practice as an essential part of the role of the teacher because, as nurses we are all involved in the practice of nursing. The paper begins by exploring the main issues that impinge upon and continue to affect the development of the teachers role. It then examines the teacher's new role in the practice area and an academic specialist and, finally, looks at the structures and conditions that will be necessary to support this role.

Humans↗

PubMed1997

Mental models, metaphors and their use in the education of nurses.

A great deal of nurses' confidence in the use of information technology (IT) depends both on the way computers are introduced to students in the college and how such education is continued and applied when they are practitioners. It is therefore vital that teachers of IT assist nurses to discover ways of learning to utilize and apply computers within their workplace with whatever methods are available. One method which has been introduced with success in other fields is the use of mental models and metaphors. Mental models and metaphors enable individuals to learn by building on past learning. Concepts and ideas which have already been internalized from past experience can be transferred and adapted for usage in a new learning situation with computers and technology. This article explores the use of mental models and metaphors for the technological education of nurses. The concepts themselves will be examined, followed by suggestions for possible applications specifically in the field of nursing and health care. Finally the role of the teacher in enabling improved learning as a result of these techniques will be addressed.

Computer-Assisted Instruction↗

PubMed1997

Effect of meal frequency and timing on physical performance.

Two areas of sports nutrition in which the periodicity of eating has been studied relate to: (1) the habitually high energy intakes of many athletes, and (2) the optimization of carbohydrate (CHO) availability to enhance performance. The present paper examines how the timing and frequency of food and fluid intake can assist the athlete and physically-active person to improve their exercise performance in these areas. Frequent eating occasions provide a practical strategy allowing athletes to increase energy intake while concomitantly reducing the gastric discomfort of infrequent large meals. The optimization of CHO stores is a special challenge for athletes undertaking prolonged training or competition sessions. This is a cyclical process with post-exercise CHO ingestion promoting muscle and liver glycogen re-synthesis; pre-exercise feedings being practised to optimize substrate availability and feedings during exercise providing a readily-available source of exogenous fuel as endogenous stores become depleted. The timing and frequency of CHO intake at these various stages are crucial determinants for optimizing fuel availability to enhance exercise capacity.

Dietary Carbohydrates↗

PubMed1997

Fluid balance during team sports.

Sweat losses during team sports are influenced by the intermittent nature of the work rates (high-intensity exercise interspersed with low-level activity and both formal and informal rest periods), and a high level of inter- and intra-individual variability in workloads. Since many team sports have evolved in countries with cool climates, traditions and rules governing the time of play, duration of play without a break, and the type of uniforms may lead to inappropriately high thermal stresses when these sports are played in hot environments (i.e. > 25 degrees C, 60% relative humidity). Fluid intake during team sports is largely determined by opportunities to drink during formal rest periods and during informal stoppages in play. Present regulations concerning fluid breaks in some sports may be inappropriate if fluid requirements of players competing in hot environments are to be met to prevent hypohydration and fatigue. Nevertheless, it appears that in most team sports, there are adequate opportunities for players to keep fluid deficits below 2% of body mass. Studies across a number of sports show that mean fluid intakes of up to 1000 ml h-1 can be achieved. Strategies are required to help team sport players realize the importance of optimal hydration, and to use or create opportunities within their sport to maximize fluid intake. Guidelines for hydration during training and competition are suggested with the proviso that these should be adapted for each individual and his or her own sport.

Climate↗

PubMed1997

Fluid balance in team sports. Guidelines for optimal practices.

Team sports require players to perform multiple work bouts at near maximal effort, punctuated with intervals of low intensity exercise or rest for the duration of a game. Such activity patterns are associated with a significant loss of body water which has a negative impact on physical and mental performance, as well as temperature regulation. There are a number of ways in which sweat losses incurred during team sports differ from those measured during prolonged, continuous exercise. Firstly, the work rate in team sports is intermittent, largely unpredictable and random in nature. Second, analyses of various team sports reveal that such games are characterised by a high degree of inter and intra-individual variability in work rates between players from the same sport. Finally, team players are less able to anticipate sweat losses than athletes competing in events which involve prolonged, continuous, moderate intensity exercise. Yet, compared with most endurance events, many team sports offer frequent opportunities to ingest adequate volumes of fluid and thus prevent exercise-induced hypohydration. The present review details the findings of modern studies which have determined body water losses and fluid intake practices of athletes from a variety of team sports. Special considerations which influence sweat loss and fluid intake that are unique to team sports are discussed, and guidelines for sound hydration strategies during training and competition are provided.

Basketball↗

PubMed1997

Nutrition for post-exercise recovery.

Recovery after exercise poses an important challenge to the modern athlete. Important issues include restoration of liver and muscle glycogen stores, and the replacement of fluid and electrolytes lost in sweat. Rapid resynthesis of muscle glycogen stores is aided by the immediate intake of carbohydrate (I g.kg-1 BM each 2 hours), particularly of high glycemic index carbohydrate foods, leading to a total intake over 24 hours of 7-10 g.kg-1 BM. Provided adequate carbohydrate is consumed it appears that the frequency of intake, the form (liquid versus solid) and the presence of other macronutrients does not affect the rate of glycogen storage. Practical considerations, such as the availability and appetite appeal of foods or drinks, and gastrointestinal comfort may determine ideal carbohydrate choices and intake patterns. Rehydration requires a special fluid intake plan since thirst and voluntary intake will not provide for full restoration of sweat losses in the acute phase (0-6 hr) of recovery. Steps should be taken to ensure that a supply of palatable drinks is available after exercise. Sweetened drinks are generally preferred and can contribute towards achieving carbohydrate intake goals. Replacement of sodium lost in sweat is important in maximising the retention of ingested fluids. A sodium content of 50-90 mmol.L-1 may be necessary for optimal rehydration; however commercial sports drinks are formulated with a more moderate sodium content (10-25 mmol.L-1). It may be necessary to consume 150% of fluid losses to allow for complete fluid restoration. Caffeine and alcohol containing beverages are not ideal rehydration fluids since they promote an increased rate of diuresis.

Dehydration↗

PubMed1996

Muscle glycogen storage after prolonged exercise: effect of the frequency of carbohydrate feedings.

We reported previously that intake of carbohydrate foods with a high glycemic index (GI) produced greater glycogen storage and greater postprandial glucose and insulin responses during 24 h of postexercise recovery than did intake of low-GI carbohydrate foods. In the present study we examined the importance of the greater incremental glucose and insulin concentrations on glycogen repletion by comparing intake of large carbohydrate meals ("gorging") with a pattern of frequent, small, carbohydrate snacks ("nibbling"), which simulates the flattened glucose and insulin responses after low-GI carbohydrate meals. Eight well-trained triathletes [x +/- SEM: 25.6 +/- 1.5 y of age, weighing 70.2 +/- 1.9 kg, and with a maximal oxygen uptake (VO2max) of 4.2 +/- 0.2 L/min] undertook an exercise trial (2 h at 75% VO2max followed by four 30-s sprints) to deplete muscle glycogen on two occasions, 1 wk apart For 24 h after each trial, subjects rested and consumed the same diet composed exclusively of high-GI carbohydrate foods, providing 10 g carbohydrate/kg body mass. The "gorging" trial provided the food as four large meals of equal carbohydrate content eaten at 0, 4, 8, and 20 h of recovery, whereas in the "nibbling" trial each of the meals was divided into four snacks and fed at hourly intervals (0-11, 20-23 h). However, there was no significant difference in muscle glycogen storage between the two groups over the 24 h (gorging: 74.1 +/- 8.0 mmol/kg wet wt; nibbling: 94.5 +/- 14.6 mmol/kg wet wt). The results of this study suggest that there is no difference in postexercise glycogen storage over 24 h when a high-carbohydrate diet is fed as small frequent snacks or as large meals, and that a mechanism other than lowered blood glucose and insulin concentrations needs to be sought to explain the reduced rate of glycogen storage after consumption of low-GI carbohydrate foods.

Adult↗

PubMed1996

Effect of oral creatine supplementation on single-effort sprint performance in elite swimmers.

Oral supplementation with creatine monohydrate (Cr.H2O) has been reported to increase muscle creatine phosphate levels. The aim of the present study was to determine the effect of such supplementation on performance of a single-effort sprint by elite swimmers. Thirty-two elite swimmers (M = 18, F = 14; age = 17-25 years) from the Australian Institute of Sport were tested on two occasions, 1 week apart. Tests performed were 25-m, 50-m, and 100-m maximal effort sprints (electronically timed with dive start, swimmers performing their best stroke), each with approximately 10 min active recovery. A 10-s maximal leg ergometry test was also undertaken. Swimmers were divided into two groups matched for sex, stroke/event, and sprint time over 50 m, and groups were randomly assigned to 5 days of Cr.H2O supplementation (4 . day-1 x 5 g Cr.H2O + 2 g sucrose, n = 16) or placebo (4 . day-1 x 5 g Polycose + 2 g sucrose, n = 16) prior to the second trial. Results revealed no significant differences between the group means for sprint times or between 10-s maximal leg ergometry power and work. This study does not support the hypothesis that creatine supplementation enhances single-effort sprint ability of elite swimmers.

Adolescent↗

PubMed1996

Body weight changes and voluntary fluid intakes during training and competition sessions in team sports.

Fluid losses (measured by body weight changes) and voluntary fluid intakes were measured in elite basketball, netball, and soccer teams during typical summer and winter exercise sessions to determine fluid requirements and the degree of fluid replacement. Each subject was weighed in minimal clothing before and immediately after training, weights, and competition sessions; fluid intake, duration of exercise, temperature and humidity, and opportunity to drink were recorded. Sweat rates were greatest during competition sessions and significantly lower during weights sessions for all sports. Seasonal variation in dehydration (%DH) was not as great as may have been expected, particularly in sports played indoors. Factors influencing fluid replacement during exercise included provision of an individual water bottle, proximity to water bottles during sessions, encouragement to drink, rules of the game, duration and number of breaks or substitutions, and awareness of personal sweat rates. Guidelines for optimizing fluid intakes in these three sports are provided.

Adolescent↗

PubMed1995

Political principles in action: a critical analysis of Education and Training: Working Paper 10 and its implications for nurse education.

Education and Training: Working Paper Ten (WP10) (Department of Health 1989a) was published in October 1989. It was an integral part of Working for Patients (Department of Health 1989b) and as such was alleged to embrace the same fundamental principles. WP10 may result in the most significant change to nurse education in the UK since the 1949 Nurses Act, with variations in its funding, structure and organisation. Surprisingly, there has been relatively little discussion about this important development within the nursing press. The aim, therefore, of this paper is to evaluate WP10 within the context of the ideology which has underpinned social policy in the last 14 years. Firstly, Conservative Party policy will be explored, the WP10 itself will then be examined in order to assess how far such principles have been applied to nurse education through its implementation. It is intended that by this process of analysis further understanding will be gained about this policy and its potential consequences for the future of nursing.

Education, Nursing↗

PubMed1995

Effect of coingestion of fat and protein with carbohydrate feedings on muscle glycogen storage.

Dietary guidelines for achieving optimal muscle glycogen storage after prolonged exercise have been given in terms of absolute carbohydrate (CHO) intake (8-10 g.kg-1.day-1). However, it is of further interest to determine whether the addition of fat and protein to carbohydrate feedings affects muscle glycogen storage. Eight well-trained triathletes [23.1 +/- 2.0 (SE) yr; 74.0 +/- 3.4 kg; peak O2 consumption = 4.7 +/- 0.4 l/min] undertook an exercise trial (2 h at 75% peak O2 consumption, followed by four 30-s sprints) on three occasions, each 1 wk apart. For 24 h after each trial, the subjects rested and were assigned to the following diets in randomized order: control (C) diet (high glycemic index CHO foods; CHO = 7 g.kg-1.day-1), added fat and protein (FP) diet (C diet + 1.6 g.kg-1.day-1 fat + 1.2 g.kg-1.day-1 protein), and matched-energy diet [C diet + 4.8 g.kg-1.day-1 additional CHO (Polycose) to match the additional energy in the FP diet]. Meals were eaten at t = 0, 4, 8, and 21 h of recovery. The total postprandial incremental plasma glucose area was significantly reduced after the FP diet (P < 0.05). Serum free fatty acid and plasma triglyceride responses were significantly elevated during the FP trial (P < 0.05). There were no differences between trials in muscle glycogen storage over 24 h (C, 85.8 +/- 2.7 mmol/kg wet wt; FP, 80.5 +/- 8.2 mmol/kg wet wt; matched-energy, 87.9 +/- 7.0 mmol/kg wet wt).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Preceptorship and post-registration nurse education.

The Report of the Post-Registration Education and Practice Project (UKCC 1990) and the Framework for Continuing Professional Education for Nurses, Midwives and Health Visitors (ENB 1991) have led to an unprecedented period of formalised supervision and support for registered practitioners in the UK. The preceptor has been identified as having a pivotal part to play in providing this support. There is however, a need for further clarification regarding the exact nature of the preceptor's role in post-registration education and practice, and the full extent of the responsibilities involved. This paper explores the issues involved in preceptorship for qualified nurses and some of the related literature. The following key questions are addressed: Who will be designated as preceptors? How will they be selected? What preparation and support will such preceptors be offered? What is the role of the preceptor and what is the conceptual and empirical difference between the preceptor and the mentor? It is proposed that strategies must be identified for clarification of the preceptor's role and responsibilities, identification of selection criteria, and the establishment of preceptor preparation programmes and support networks.

Education, Nursing, Continuing↗

PubMed1994

Teacher self-evaluation: an assessment using Delamont's 'beyond Flanders' fields' technique.

Teacher appraisal is an issue which is becoming increasingly important in nurse education today. One potential system of evaluation which is currently under-valued and under-utilised within nurse education is self-assessment. This paper explores the issues involved through the application of Delamont's 'beyond Flanders' fields' assessment tool to an excerpt of teaching recorded on video tape. It concludes that self-assessment has significant value in developing the reflection skills of the teacher and thereby improving the quality of education delivered. It should therefore form a significant part of any appraisal event.

Faculty, Nursing↗

PubMed1993

The future of the specialist nurse teacher: two different models explored.

The demand for more specialised nurse educators is increasing, yet the nature and direction of this specialisation remains unclear. In this paper the strengths and limitations of two different models are evaluated focusing on the organisation and management of education, integration of theory with practice, the skill of teaching itself and the implications for clinical practice.

Faculty, Nursing↗

PubMed1993

Muscle glycogen storage after prolonged exercise: effect of the glycemic index of carbohydrate feedings.

The effect of the glycemic index (GI) of postexercise carbohydrate intake on muscle glycogen storage was investigated. Five well-trained cyclists undertook an exercise trial to deplete muscle glycogen (2 h at 75% of maximal O2 uptake followed by four 30-s sprints) on two occasions, 1 wk apart. For 24 h after each trial, subjects rested and consumed a diet composed exclusively of high-carbohydrate foods, with one trial providing foods with a high GI (HI GI) and the other providing foods with a low GI (LO GI). Total carbohydrate intake over the 24 h was 10 g/kg of body mass, evenly distributed between meals eaten 0, 4, 8, and 21 h postexercise. Blood samples were drawn before exercise, immediately after exercise, immediately before each meal, and 30, 60, and 90 min post-prandially. Muscle biopsies were taken from the vastus lateralis immediately after exercise and after 24 h. When the effects of the immediate postexercise meal were excluded, the totals of the incremental glucose and insulin areas after each meal were greater (P < or = 0.05) for the HI GI meals than for the LO GI meals. The increase in muscle glycogen content after 24 h of recovery was greater (P = 0.02) with the HI GI diet (106 +/- 11.7 mmol/kg wet wt) than with the LO GI diet (71.5 +/- 6.5 mmol/kg). The results suggest that the most rapid increase in muscle glycogen content during the first 24 h of recovery is achieved by consuming foods with a high GI.

Adolescent↗

PubMed1993

Dietary supplements in sport.

Studies of the dietary practices of athletes report that nutritional supplements are commonly used. Supplementation practices vary between sports and individual athletes; however, there is evidence that at least some athletes use a large number of supplements concurrently, often in doses that are very high in comparison with normal dietary intakes. In exploring supplementation practices we propose a classification system separating the supplements into dietary supplements and nutritional erogogenic aids. The dietary supplement is characterised as a product which can be used to address physiological or nutritional issues arising in sport. It may provide a convenient or practical means of consuming special nutrient requirements for exercise, or it may be used to prevent/reverse nutritional deficiencies that commonly occur among athletes. The basis of the dietary supplement is an understanding of nutritional requirements and physiological effects of exercise. When the supplement is used to successfully meet a physiological/nutritional goal arising in sport it may be demonstrated to improve sports performance. While there is some interest in refining the composition or formulation of some dietary supplements, the real interest belongs to the use or application of the supplement; i.e. educating athletes to understand and achieve their nutritional needs in a specific sports situation. The sports drink (carbohydrate-electrolyte replacement drink) is a well known example of a dietary supplement. Scientific attitudes towards the sports drink have changed over the past 20 years. Initial caution that carbohydrate-electrolyte fluids compromise gastric emptying during exercise has now been shown to be unjustified. Numerous studies have shown that 5 to 10% solutions of glucose, glucose polymers (maltodextrins) and other simple sugars all have suitable gastric emptying characteristics for the delivery of fluid and moderate amounts of carbohydrate substrate. The optimal concentration of electrolytes, particularly sodium, remains unknown. Most currently available sports drinks provide a low level of sodium (10 to 25 mmol/L) in recognition that sodium intake may promote intestinal absorption of fluid as well as assist in rehydration. The sodium level of commercial oral rehydration fluids (used in the clinical treatment of diarrhoea and dehydration) is higher than that of the present range of sports drinks. However, even if research indicates that intestinal glucose transport is optimally stimulated at higher sodium concentrations, concern for the palatability of sports drinks may impose a lower ceiling for sodium levels. Commercial viability of a sports drink requires that it provide a refreshing and palatable fluid replacement across a wide variety of sports and exercise situations.(ABSTRACT TRUNCATED AT 400 WORDS)

Calcium, Dietary↗