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Biomedical subjects

M Kingsley

Publications and source records attributed to M Kingsley.

8 recordsLinked to original sources
PubMed2006

An exercise protocol that simulates the activity patterns of elite junior squash.

Squash is a popular racket sport that requires intermittent activity with frequent bursts of near maximal-intensity exercise. Consequently, effective physiological and thermoregulatory responses are important contributors to performance during squash match-play. Controlled field-based simulation protocols have been introduced in a growing number of sports, which allow sports scientists to investigate changes in physiology and the efficacy of various interventions in sport-specific contexts. This study aimed to develop an exercise protocol that simulates the physiological requirements of elite squash match-play. Eight elite junior squash players (age 16.2+/-0.8 years, height 1.76+/-0.06 m, body mass 61.3+/-5.9 kg; mean+/-s) completed the following in a randomized order: (1) a squash match against a player of similar standard and (2) a squash-specific incremental exercise protocol (multistage squash test [MST]) followed by the squash simulation protocol (SSP). The multistage squash test was continued for 18.0+/-1.0 min and elicited near maximal post-MST heart rates, blood lactate concentrations and ratings of perceived exertion (198+/-9 beats.min-1, 5.7+/-1.7 mmol.l-1 and 18+/-1, respectively). The SSP was 12.2 min in length compared with mean game length during competitive matches of 10.0+/-1.6 min (P=0.27). Peak heart rates were similar during the SSP and match-play (192+/-11 and 189+/-6 beats.min-1, respectively; P=0.44). Mean exercising heart rates were similar during the SSP (180+/-8 beats.min-1) and match-play (179+/-13 beats.min-1; P=0.73). Peak blood lactate concentrations during the SSP and match-play were 3.5+/-1.5 and 2.4+/-1.2 mmol.l-1 (P=0.07), respectively. Peak ratings of perceived exertion during the SSP and match-play were similar (17+/-2 and 17+/-2, respectively; P=0.64). It was concluded that the SSP closely replicated the demands of squash match-play in elite junior squash players. Furthermore, the SSP provides coaches and scientific support staff with a controlled squash-specific exercise protocol that has potential application in the objective investigation of a range of interventions such as training programmes, nutritional supplements and strategies to maintain core body temperature.

Adolescent↗
PubMed2001

Muscle soreness and damage parameters after prolonged intermittent shuttle-running following acute vitamin C supplementation.

Exercise-induced free-radical production may be partly responsible for muscle soreness and damage following demanding exercise. A number of studies have investigated the effect of antioxidant supplementation although there is a paucity of information regarding vitamin C. Therefore the aim of the present study was to investigate the effect of vitamin C supplementation on exercise-induced muscle soreness and damage. Nine habitually active males consumed a 1 g dose of vitamin C 2 h before exercise, and on another occasion consumed an identical placebo. The exercise comprised a 90 min intermittent shuttle-running test, which was designed to simulate the multiple-sprint sports. Vitamin C supplementation increased plasma concentrations of vitamin C before exercise, and plasma concentrations continued to increase during the shuttle-run to reach a peak of approximately 200 micromol x l(-1) immediately after exercise. However, muscle soreness, and markers of both muscle damage (creatine kinase and aspartate aminotransferase) and lipid peroxidation (malondialdehyde) were elevated to an equal extent after exercise in placebo and supplemented trials. Therefore acute supplementation with vitamin C had no beneficial effects although it is possible that such short-term vitamin C supplementation was ineffective because it occurred at an inappropriate time.

Administration, Oral↗
PubMed1996

Appearance of nuclear protease activity after embryonal carcinoma cells undergo differentiation.

Proteolytic systems are involved via multiple mechanisms in the regulation of gene expression, including tightly controlled metabolism of transcription factors. In this study, we demonstrate that differentiation of mouse embryonal carcinoma cells to parietal endoderm-like cells is accompanied by the appearance of nuclear protease activity. Interestingly, this nuclear-associated protease activity is not observed in the visceral endoderm-like cell line, PSA-5E, or in the differentiated cells derived from both mouse embryonic stem cells and the human embryonal carcinoma cell line NT2/D1. We also determined that this differentiation-associated nuclear protease activity causes proteolysis of a wide range of different transcription factors, including ATF-1, Sp1, NF-YA and B, and octamer-binding proteins Oct-1 and Oct-3. Based on the effects of specific inhibitors, the nuclear protease(s) can be classified as a cysteine protease; however, lack of inhibition by calpastatin and EGTA distinguishes this protease activity from the calpain family of proteases. Given the properties of the differentiation-associated nuclear protease(s), we discuss the possibility that this protease(s) plays a role in the metabolism of transcription factors during the differentiation of specific embryonic cells.

Animals↗
PubMed1994

Genetic variation of the St. Lawrence beluga whale population assessed by DNA fingerprinting.

Recent surveys suggest that the endangered St. Lawrence beluga (Delphinapterus leucas) population is not recovering significantly despite 20 years of protection. Dead individuals that have been autopsied show high levels of tumours and infections. This situation could be a result of pollution, loss of genetic variation, inbreeding depression or a combination of these factors. Analyses of DNA fingerprints from St. Lawrence belugas with three minisatellite probes (Jeffreys 33.6, 33.15 and M13) indicate a reduced level of genetic variation compared to Beaufort Sea animals. The average band-sharing between individuals of the St. Lawrence beluga population for the three probes (0.534, 0.573 and 0.478, respectively) was significantly higher than that of the Beaufort Sea beluga population (0.343, 0.424, 0.314, respectively). Higher levels of mean allele frequency in the St. Lawrence belugas (0.33 vs. 0.21) suggest that this population is composed of individuals which are related. Inbreeding depression could therefore be a factor in the lack of recovery of the St. Lawrence beluga population.

Alleles↗
PubMedDate not supplied

Comparison of Polar 810s and an ambulatory ECG system for RR interval measurement during progressive exercise.

Ambulatory heart rate monitors and clinical electrocardiographic (ECG) devices are capable of measuring the length of consecutive cardiac periods (RR intervals). The aim of the study was to assess the agreement between the Polar 810s heart rate monitor (Polar) and the Reynolds digital ambulatory ECG using Pathfinder software version 8.4 (Reynolds v8.4) during cycle ergometry. For this purpose, eight subjects completed incremental cycling exercise that began at 60 W and increased by 30 W each 2-minute period until volitional fatigue. Simultaneous recording of the ECG (Reynolds Pathfinder), RR interval (Polar), and respiratory parameters (Metamax 3B) were undertaken at rest and throughout the exercise period. No significant differences were found in RR intervals measured by Polar and Reynolds v8.4 at any relative intensity. Polar and Reynolds v8.4 displayed strong linear relationships at all relative intensities (r2=0.927 to 0.998). Bland and Altman analyses between Polar and Reynolds v8.4 consistently demonstrated minimal bias in absolute RR interval (<0.10 ms) and the limits of agreement for group differences in RR interval and heart rate were less than +/- 10 ms and +/- 2 beats.min (-1) for all relative intensities, respectively. Power spectral analysis provided similar results for both systems in all bandwidths studied during rest and low intensity exercise. However, significant differences and large relative limits of agreement (>100 % of mean of paired means) were identified in UF at intensities > 40 % VO2max, HF at intensities > 60 % VO2max and LF during exercise at 80-100 % VO2max. These findings demonstrate that RR intervals and heart rate measurements obtained using Polar and Reynolds v8.4 are in good agreement. However, caution should be exercised when interpreting spectral analysis of RR interval data derived from different acquisition systems during physical activity.

Adult↗
PubMedDate not supplied

[A study of the effectiveness of the bereavement program of Severance Hospice].

Grief that is not acknowledged and worked through may manifest itself in some emotional, mental or physical problem. In recent years much as been learned about coping with grief which the hospice program can utilize to help family members cope with their grief. This study was carried out to determine the helpfulness of the bereavement care of Severance Hospice and to learn more about the grief response of the bereaved. The tools used to collect data were an assessment form used in the bereavement program and the Grief Experience Inventory developed by Sanders and revised and translated by the researcher. Data was obtained from bereaved family members (54 for the final grief assessment and 39 for the grief response assessment) receiving bereavement follow-up, from July 1989 to March 1991. Results of the study were as follows: 1. Final Grief Assessment Regarding the resolution of their grief the majority of the bereaved accepted the reality of the death of their family member, while slightly more than three-quarters were able to express their feelings toward their loss. A large majority had returned to activities of daily living well or fairly well and had reinvested their energy in a person other than the deceased. In addition, the physical condition of the majority was good or fairly good. A majority of the bereaved considered the bereavement care to be helpful and almost three-quarters were not considered to be in need of more follow-up. 2. Grief Response Assessment Age was found to have a moderately positive correlation to appetite disturbance (r = .41, P less than .01) and loss of vigor (r = .37, P less than .01) A moderately positive correlation was found between the number of contacts and sleep disturbance (r = 2.38, P less than .01) Significant differences were found between men and women in regard to guilt (t = 2.38, P less than .05), social isolation (t = 2.44, P less than .05) and depersonalization (t = 2.07, P less than .05) with men having the more intense grief. Significant differences were found in the grief responses of somatization (F = 5.82, P less than .001), physical symptoms (F = 5.87, P less than .001), appetite disturbance (F = 4.40, P less than .01), despair (3.79, P less than .01), anger (Fp2.83, P less than .05), social isolation (F = 3.61, P less than .05), guilt (F = 3.62, P less than .05) and depersonalization (F = 2.58, P less than .05).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗