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Biomedical subjects

H Carter

Publications and source records attributed to H Carter.

At least 37 records · Page 2Linked to original sources
PubMed2000

Androstenetriol and androstenediol. Protection against lethal radiation and restoration of immunity after radiation injury.

Androstenetriol (AET) and Androstenediol (AED) upregulate host immunity, leading to increased resistance against infections. AET augments IL-2, IL-3, IFN gamma levels, and counteracts hydrocortisone immune suppression. AET and AED at a dose of 0.75 mg/- and 8.0 mg/25-g mouse, protected 60 and 70%, respectively, of C57/BL/6J mice irradiated with a lethal dose. These hormones also protected mice irradiated with 6 Gy and infected with a coxsackievirus B4 LD50. AET significantly increased spleen lymphocyte numbers at 7, 14, and 21 days after a 6-Gy exposure. Fluorescent activated cell-sorter analysis of irradiated mice, spleen, and bone marrow showed that AET significantly augmented the myeloid precursor markers, CD11b/Mac-1, and B220 (pan B), as well as the absolute numbers of CD4+/CD8+ cells over the 21 days of testing. Overall, the data are consistent with AET/AED inducing a more rapid recovery of all hematopoietic precursors from the small number of surviving stem cells.

Anabolic Agents↗
PubMed2000

Oxygen uptake kinetics in treadmill running and cycle ergometry: a comparison.

The purpose of the present study was to comprehensively examine oxygen consumption (VO(2)) kinetics during running and cycling through mathematical modeling of the breath-by-breath gas exchange responses to moderate and heavy exercise. After determination of the lactate threshold (LT) and maximal oxygen consumption (VO(2 max)) in both cycling and running exercise, seven subjects (age 26.6 +/- 5.1 yr) completed a series of "square-wave" rest-to-exercise transitions at running speeds and cycling power outputs that corresponded to 80% LT and 25, 50, and 75%Delta (Delta being the difference between LT and VO(2 max)). VO(2) responses were fit with either a two- ( LT) exponential model. The parameters of the VO(2) kinetic response were similar between exercise modes, except for the VO(2) slow component, which was significantly (P < 0.05) greater for cycling than for running at 50 and 75%Delta (334 +/- 183 and 430 +/- 159 ml/min vs. 205 +/- 84 and 302 +/- 154 ml/min, respectively). We speculate that the differences between the modes are related to the higher intramuscular tension development in heavy cycle exercise and the higher eccentric exercise component in running. This may cause a relatively greater recruitment of the less efficient type II muscle fibers in cycling.

Adult↗
PubMed2000

Effects of prior heavy exercise on phase II pulmonary oxygen uptake kinetics during heavy exercise.

We tested the hypothesis that heavy-exercise phase II oxygen uptake (VO(2)) kinetics could be speeded by prior heavy exercise. Ten subjects performed four protocols involving 6-min exercise bouts on a cycle ergometer separated by 6 min of recovery: 1) moderate followed by moderate exercise; 2) moderate followed by heavy exercise; 3) heavy followed by moderate exercise; and 4) heavy followed by heavy exercise. The VO(2) responses were modeled using two (moderate exercise) or three (heavy exercise) independent exponential terms. Neither moderate- nor heavy-intensity exercise had an effect on the VO(2) kinetic response to subsequent moderate exercise. Although heavy-intensity exercise significantly reduced the mean response time in the second heavy exercise bout (from 65.2 +/- 4.1 to 47.0 +/- 3.1 s; P < 0.05), it had no significant effect on either the amplitude or the time constant (from 23.9 +/- 1.9 to 25.3 +/- 2.9 s) of the VO(2) response in phase II. Instead, this "speeding" was due to a significant reduction in the amplitude of the VO(2) slow component. These results suggest phase II VO(2) kinetics are not speeded by prior heavy exercise.

Adult↗
PubMed2000

Effect of endurance training on oxygen uptake kinetics during treadmill running.

The purpose of this study was to examine the effect of endurance training on oxygen uptake (VO(2)) kinetics during moderate [below the lactate threshold (LT)] and heavy (above LT) treadmill running. Twenty-three healthy physical education students undertook 6 wk of endurance training that involved continuous and interval running training 3-5 days per week for 20-30 min per session. Before and after the training program, the subjects performed an incremental treadmill test to exhaustion for determination of the LT and the VO(2 max) and a series of 6-min square-wave transitions from rest to running speeds calculated to require 80% of the LT and 50% of the difference between LT and maximal VO(2). The training program caused small (3-4%) but significant increases in LT and maximal VO(2) (P<0.05). The VO(2) kinetics for moderate exercise were not significantly affected by training. For heavy exercise, the time constant and amplitude of the fast component were not significantly affected by training, but the amplitude of the VO(2) slow component was significantly reduced from 321+/-32 to 217+/-23 ml/min (P<0.05). The reduction in the slow component was not significantly correlated to the reduction in blood lactate concentration (r = 0. 39). Although the reduction in the slow component was significantly related to the reduction in minute ventilation (r = 0.46; P<0.05), it was calculated that only 9-14% of the slow component could be attributed to the change in minute ventilation. We conclude that the VO(2) slow component during treadmill running can be attenuated with a short-term program of endurance running training.

Adult↗
PubMed2000

The effect of endurance training on parameters of aerobic fitness.

Endurance exercise training results in profound adaptations of the cardiorespiratory and neuromuscular systems that enhance the delivery of oxygen from the atmosphere to the mitochondria and enable a tighter regulation of muscle metabolism. These adaptations effect an improvement in endurance performance that is manifest as a rightward shift in the 'velocity-time curve'. This shift enables athletes to exercise for longer at a given absolute exercise intensity, or to exercise at a higher exercise intensity for a given duration. There are 4 key parameters of aerobic fitness that affect the nature of the velocity-time curve that can be measured in the human athlete. These are the maximal oxygen uptake (VO2max), exercise economy, the lactate/ventilatory threshold and oxygen uptake kinetics. Other parameters that may help determine endurance performance, and that are related to the other 4 parameters, are the velocity at VO2max (V-VO2max) and the maximal lactate steady state or critical power. This review considers the effect of endurance training on the key parameters of aerobic (endurance) fitness and attempts to relate these changes to the adaptations seen in the body's physiological systems with training. The importance of improvements in the aerobic fitness parameters to the enhancement of endurance performance is highlighted, as are the training methods that may be considered optimal for facilitating such improvements.

Adaptation, Physiological↗
PubMed2000

Quality of information on hospice referral.

Good quality referral information provides hospice staff with essential information at a time when patients are particularly vulnerable. An Ideal Referral Criteria tool for measuring the quality of general practitioners' information was piloted at one hospice site. Overall inter-rater reliability was 90%, with individual categories ranging from 19% to 34%. Cronbach's alpha was 0.35. Further psychometric testing is recommended.

Family Practice↗
PubMed2000

Hospital referrals to a hospice: timing of referrals, referrers' expectations, and the nature of referral information.

Hospital referrals to Mary Potter Hospice were reviewed prior to the implementation of a new hospital palliative care support service. The hospital palliative care service aims to improve the communication between health professionals in the acute hospital and hospice, and to advise the hospital staff on its management of terminally ill patients. The purpose of this review was to provide baseline information that would assist the hospice with the planning and future evaluation of the new service. Information included the timing of the referrals, the type of referral information provided by hospital doctors, and their expectations of hospice care. One fifth of patients were referred near to death. While medical information was nearly always provided on referral, information on the psychological, spiritual and social dimensions of care was often absent. A third of hospital doctors expressed their expectation of the hospice as "to take over" the patient's care. This suggests the hospital palliative care support service should encourage health professionals to take a more active role in caring for dying patients. The findings are discussed in relation to the goals of the new hospital palliative care support service.

Aged↗
PubMed1999

The development of funding policies for hospices: is casemix-based funding an option?

The 1993 health reforms, with their emphasis on the purchasing of defined amounts or units of service, have led to the implementation of casemix-based funding for the acute medical and surgical services of the public hospitals. Despite growing interest in New Zealand in casemix-based funding for non-acute services such as palliative care, the nature of this service and the characteristics of its patient population pose particular difficulties for the development and implementation of casemix. This paper examines the feasibility of implementing casemix-based funding for hospice/palliative care services and discusses the development of casemix classification systems for palliative care. Problems associated with implementing casemix-based funding are considered including: the dual funding of hospices, the multi-agency nature of palliative care service provision and the need for the Health Funding Authority to identify and specify the hospice services it is willing to fund. While it is concluded that these problems will impede the introduction of casemix-based funding of hospice care, they highlight important issues that the hospice movement must address if it is to ensure its future within the new health environment.

Diagnosis-Related Groups↗
PubMed1999

Effect of 6 weeks of endurance training on the lactate minimum speed.

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s: age 23+/-4 years; body mass 69.7+/-9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23+/-4 years; body mass 72.7+/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO2max, running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol x l(-1); and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO2max, running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol x l(-1) or the lactate minimum speed. In the training group, there was a significant increase in VO2max (from 47.9+/-8.4 to 52.2+/-2.7 ml x kg(-1) x min(-1)), running speed at the maximal lactate steady state (from 13.3+/-1.7 to 13.9+/-1.6 km x h(-1)), running speed at the lactate threshold (from 11.2+/-1.8 to 11.9+/-1.8 km x h(-1)) and running speed at a blood lactate concentration of 3 mmol x l(-1) (from 12.5+/-2.2 to 13.2+/-2.1 km x h(-1)) (all P < 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0+/-0.7 to 10.9+/-1.7 km x h(-1)). The results demonstrate that the lactate minimum speed, when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.

Adult↗
PubMed1999

Effect of incremental test protocol on the lactate minimum speed.

PURPOSE: The purpose of this study was to investigate the effect of altering the initial running speed (RS) in the incremental portion of the lactate minimum test on the lactate minimum speed (LMS). METHODS: Eight well-trained endurance runners (mean +/- SD age 29.0 +/- 5.4 yr, body mass 72.0 +/- 5.6 kg, VO2max 63.1 +/- 3.8 mL x kg(-1) min(-1)) completed a standard incremental treadmill test for the assessment of the lactate threshold (LT) and VO2max, and eight lactate minimum tests. Following a period of supramaximal exercise, subjects were allowed 8 min of recovery to allow blood [lactate] to peak. Subjects then undertook eight randomly-assigned incremental treadmill tests from different initial running speeds (3.0, 2.5, 2.0, 1.5, 1.0, and 0.5 km x h(-1) below the predetermined RS-LT, at the RS-LT, and at 1.0 km x h(-1) above the RS-LT) with RS increased by 1.0 km x h(-1) every 5 min until volitional fatigue. Blood samples for the determination of blood [lactate] were taken at the end of each stage and the LMS was determined by fitting a spline function to the data. RESULTS: No LMS could be determined for the two highest initial RS conditions. For the other conditions, the LMS was significantly affected by the initial RS used in the incremental test and varied from 13.8 +/- 0.7 km x h(-1) with an initial RS of 3.0 km x h(-1) below the RS-LT, to 15.8 +/- 0.8 km x h(-1) with an initial RS of 0.5 km x h(-1) below the RS-LT. The LMS was significantly different from the RS-LT (15.4 +/- 0.8 km x h(-1)) (P < 0.05), except when the incremental test started at 1.0 or 1.5 km x h(-1) below the RS-LT. CONCLUSIONS: These results suggest that the LMS test is not a valid method for estimation of the LT since it is profoundly influenced by the starting speed selected for the incremental portion of the test.

Adult↗
PubMed1999

A disproportionate increase in VO2 coincident with lactate threshold during treadmill exercise.

PURPOSE: The purpose of this study was to assess the relationship between pulmonary VO2 and running speed over a range of exercise intensities. During constant-load cycle exercise above the lactate threshold (Tlac), it has been shown that VO2 does not attain a steady state within 3 min but continues to rise until either a delayed but elevated steady-state VO2 is attained or exhaustion occurs. Since this greater oxygen cost of exercise (V02 slow component) has only been demonstrated at discrete exercise intensities above Tlac, it was hypothesised that the onset of the VO2 slow component would coincide with Tlac during an incremental test if the stage durations were of sufficient length. METHODS: Five male subjects (mean +/- SD age 31 +/- 2 yr: VO2peak 60.1 +/- 5.8 mL x kg(-1) x min(-1)) performed four identical treadmill tests within an 8-d period. The tests involved the completion of six stages of 7-min duration. Running speed was increased by 0.5 km x h(-1) between stages. In the first test, fingertip capillary blood was sampled at the end of each stage for determination of Tlac. For all tests expired air was collected into Douglas bags from 3.0 to 3.75 min and from 6.0 to 6.75 min of each stage to determine any increase in V02 (deltaVO2) over the duration of the stage. RESULTS: The mean deltaVO2 for each stage over the four tests was determined for each subject. Repeated measures ANOVA with post-hoc Tukey tests revealed a significant increase in deltaVO2 at running speeds above, but not below, Tlac. CONCLUSIONS: The results of this study confirm the close association between the VO2 slow component and the onset of lactic acidosis and demonstrate alinearity in the VO2-exercise intensity relationship above Tlac for incremental treadmill exercise.

Adult↗
PubMed1998

Characteristics of responders and non-responders in an infant feeding study.

BACKGROUND: Few studies have fully investigated and described the characteristics of non-responders in infant breast feeding studies. Examination of the characteristics of non-responders enhances this understanding and provides information on the representativeness of the sample actually investigated. METHODS: As part of a larger local longitudinal study, couples whose babies were due to be born during the three months of the study in the autumn of 1995, at two local maternity hospitals, were approached by midwives to participate in the study of infant feeding patterns and determinants, including interviews, questionnaires and postal survey. From the 648 eligible mothers, 91 (14 per cent) were not approached, 233 (35.9 per cent) consented but were not interviewed, 256 (39.5 per cent) consented and were interviewed and 68 (10.5 per cent) refused to participate (non-responders) in the longitudinal study. To make a comparison between the 'responders' (i.e. the 233 who consented but were not interviewed and the 256 who consented and were interviewed) and non-responders (the 68 who refused to consent), appropriate data were collected on their socio-demographic characteristics, their feeding intentions and their feeding behaviour. RESULTS: Univariate analysis revealed a number of significant differences between responders and non-responders. However, log-linear analysis of these differences indicated that the main factors that differentiated between responders and non-responders were social class, smoking habit and actual feeding behaviour. When comparing the feeding intention at the time of 'booking', the non-responders compared with the responders were less likely to intend to breastfeed and more likely to be uncertain about their feeding intentions. Following delivery non-responders compared with responders were more likely to bottle feed their babies. By the time of discharge, of the non-responders, 83.6 per cent were bottle feeding in comparison with 47.3 per cent of responders who were also bottle feeding. CONCLUSIONS: In this study non-responders were found to be more similar to bottle-feeding responders than to breastfeeding responders. Furthermore, non-responders were more likely to be smokers, from lower social class and to bottle feed. This study also showed that the non-responders were more undecided about their feeding intention at the time of the booking visit. Invariably a higher percentage of mothers who were undecided at the booking visit chose to bottle feed their babies at discharge. These results highlight the impact of failing to include information from non-responders when conducting research which examines patterns of infant breastfeeding and attitudes towards it.

Adult↗
PubMed1998

Health professionals' responses to multiple sclerosis and motor neurone disease.

This study compares the responses of health professionals to multiple sclerosis (MS) and motor neurone disease (MND) in order to determine similarities and variations in responses to the two disorders and the issues critical to caring for patients with these conditions. Health professionals were more negative about MND compared with MS in terms of the amount they felt able to offer patients, their confidence in managing patients and their ability to convey hope. For a number of issues concerning the management of patients, the level of difficulty experienced by health professionals was similar for both MS and MND. These were resource issues, the health professionals' ability to remain positive in the face of progressive disability, interdisciplinary team problems and difficulties regarding patient care. The main concern of health professionals, for both conditions, was the effect of progressive disability on the patient. For MND, management issues which health professionals found comparatively more difficult than for MS were patients' short prognosis and impending death, communication problems and progressive disability. Issues which were comparatively more difficult for MS than MND were changes in patients' affect, cognition and personality, problems with planning care because of the disorder's unpredictable course, problems with diagnosis such as making and disclosing the diagnosis, and the tendency for patients to be difficult or demanding. Some notable differences in responses between health professionals in different health care settings were found. The findings have implications for changing health professionals' conceptualization of 'hope', developing ways of improving communication between health professionals in different health care settings so as to enable them to learn from each other's expertise and experiences and redressing gaps in service provision, especially for young people with MS.

Attitude of Health Personnel↗
PubMed1997

Profiling the care needs of the population with dementia: a survey in central Scotland.

OBJECTIVE: To demonstrate a low-cost method of producing local information for dementia service planning. DESIGN: (1) Multiservice census. (2) Stratified random sample survey (stratified by setting) to assess needs. SETTING: All community and institutional settings in Forth Valley Health Board area. PARTICIPANTS: (1) People age 65 + defined by health and social care professionals as having 'problems of memory/confusion (as is caused by dementia)' (N = 2060). (2) As (1) excluding those with score < 2 on Levin's checklist and no relevant known diagnosis (N = 286). MAIN OUTCOME MEASURES: Coverage of population with dementia against EURODEM prevalence. Place of residence of sufferers. Level of care needs. MAIN RESULTS: Identified population, pro-rating for identifiable non-response, accounted for 78% of EURODEM prevalence. Assuming unidentified 22% to live at home, 45% of total population with dementia were in some form of institutional care. Survey demonstrated high levels of need in local population with dementia known to services. Assistance was required more than once a day with mobility by 48%, personal care by 60%, domestic tasks by 75% and because of behavioural problems by 57%. Assistance was required at night by 59% because of personal care needs and by 54% because of behaviour problems. CONCLUSIONS: The value of a broad-based survey 'snapshot' across the range of settings was confirmed. It can be accomplished relatively quickly and cheaply and complements information collected in other ways.

Aged↗
PubMed1997

Case-control study of GP attendance rates by suicide cases with or without a psychiatric history.

BACKGROUND: Targets for reduction in suicide deaths have been set against a background of an increasing number of people committing suicide. It is often assumed that a reduction can be effected by increasing the detection in primary care of patients at risk. This presupposes that there are indicators that enable suicide risk to be detected reliably. AIM: To compare the characteristics of those who commit suicide with an age- and sex-matched control group in terms of level of general practitioner attendance, diagnosis and pharmacological treatment of mental illness, and to compare those suicides with and without a psychiatric history in terms of general practitioner attendance and history of pharmacological treatment. METHOD: From a total of 48 deaths attributed to suicide and undetermined causes in the Forth Valley in 1993, general practice case notes were located for 41. Live controls were matched to index cases by age, sex and practice. Information on consultations, referrals to secondary care, medication and diagnoses in the previous 10 years was extracted from general practice and, for suicides, psychiatric case notes. RESULTS: Over the 10-year period, suicide patients attended their general practitioner at a higher level than control subjects. However, the number of suicide patients who attended their general practitioner in the month before their death did not differ in comparison with control subjects over a similar period. Suicide cases, in comparison with control subjects, were more likely to have received a psychiatric diagnosis from their general practitioner, been prescribed psychotropic medication and received referral to specialist mental health services. Those suicide patients with a psychiatric history had a significantly higher number of general practitioner consultations than those without a psychiatric history in four out of the five years preceding death. Those suicide patients without a psychiatric history did not differ significantly from control subjects on any of the variables assessed. CONCLUSION: For those people committing suicide who do not have a psychiatric history and whose consultation patterns do not differ from the norm, it is difficult to suggest how general practitioners might improve their detection of relevant suicidal risk factors. For those patients with a psychiatric history who commit suicide, until we have more detailed information regarding the specific content of general practitioner's consultations before death and how these differed from other consultations of the deceased, then it is premature to assume that general practitioners are failing to identify indicators of impending suicide.

Adult↗
PubMed1996

Nursing attitudes to the care of elderly patients at risk of continuing hospital care.

This study assesses changes in nurses' attitudes to the process of decision-making regarding the care of elderly patients identified as being at risk of continuing (long-term) hospital care. It was undertaken during the course of an evaluation of an intervention programme which involved a new approach to decision-making concerning the long-term care of dependent elderly patients. Complementary components of the intervention programme were: (a) an early discharge planning service; and (b) an extended home care programme. The programme involved close liaison of specially trained community health nurses with staff members of the general medical wards of a large general hospital. At the onset of the evaluation, it was perceived by management that the staff of the general medical wards favoured continuing hospital care for very dependent elderly patients rather than community care. It was hypothesized that the intervention programme would result in a change in ward staffs' attitudes concerning the feasibility of home-based care and how decisions about care should be made. To test this, attitude changes of community health nurses and ward nurses were assessed over the period of implementation of the programme. Following the introduction of the programme, the study found that some of the ward nurses' attitudes became closer to those of community health nurses. There was a shift in ward nurses' attitudes away from a professional approach to decisions about the care and placement of very dependent elderly patients to a 'patient choice' approach. Nurses felt more strongly that they had an important role in patient care. Implications of the research are considered in relation to the process of discharge planning.

Aged↗