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Biomedical subjects

N Caine

Publications and source records attributed to N Caine.

At least 37 records · Page 2Linked to original sources
PubMed1999

Thermal and metabolic responses of women with high fat versus low fat body composition during exposure to 5 and 27 degrees C for 120 min.

BACKGROUND: Men with high fat body composition maintain higher core temperatures, and lower aerobic metabolic rates than their low fat counterparts thus, verifying the insulatory benefit of body fat. Females, on average have more body fat and less muscle mass than males, and may maintain rectal temperature (Tre) at a lower energy cost. METHODS: The present investigation dichotomized female subjects by percent fat (low fat; n = 3, LF = 19.2+/-3% vs. high fat; n = 4 HF: 29.9+/-3%) to elucidate the thermal and metabolic responses during acute exposure to 5 and 27 degrees C air for 120 min. An ANOVA was used to examine the following: Tre (degrees C), mean skin temperature (Tsk; degrees C), oxygen consumption (VO2; ml x kg(-1) x min(-1)) and tissue insulation (I; degrees C x m2 x W(-1)). For Tre, a significant fat x time interaction (p < 0.05) was demonstrated at both 5 and 27 degrees C, whereby Tre tended to be lower in the LF group than the HF group. VO2 at 5 degrees C demonstrated a main effect for time only. For I, a main effect for time was noted at 5 degrees C. Also for I, a trend (p = 0.06) toward a main effect of fat during exposure to 5 degrees C was noted while at 27 degrees C a main effect (p < 0.05) was demonstrated. RESULTS: From this data it appears that under these conditions, the HF group demonstrated higher Tre and I values than their LF counterparts that was not accompanied with a differential response with respect to aerobic metabolic rate. Thus, the impact of body composition on energy expenditure to maintain Tre differs between LF and HF males and females.

Adipose Tissue↗
PubMed1999

Thermal and metabolic responses of high and low fat women to cold water immersion.

BACKGROUND: At rest during cold exposure, the amount of body fat plays an important role in the maintenance of core temperature. High fat (HF) individuals would therefore have an advantage as compared with their low fat (LF) counterparts. Since females usually have a higher amount of body fat than males they are expected to maintain core temperature at a lower energy cost. METHODS: The purpose of the present investigation was to dichotomize female subjects by percent fat (LF = 20.5 +/- 2%, n = 6 vs. HF = 30 +/- 3%, n = 6) to elucidate the thermal and metabolic responses during acute exposure to 17 degrees C water for 120 min. The following variables were measured: rectal temperature (Tre; degrees C), mean skin temperature (Tsk; degrees C), oxygen consumption (VO2; ml x kg(-1) x min(-1)), and tissue insulation (I; degrees C x m2 x W(-1)). The experiment-wise error rate was set a priori at p = 0.05. RESULTS: Unexpectedly, only one of the variables demonstrated a main effect for fat (p < 0.05). Tre demonstrated a significant (p < 0.05) group by time interaction. However, Tsk and I demonstrated a main effect for time (p < 0.05). While VO2 demonstrated an increase across time, these changes were non-significant (p > 0.05). It appears that the HF group demonstrated a similar thermal (I and Tsk) and metabolic (VO2) response as compared with the LF counterparts. However, the LF groups maintained a lower Tre as compared with the HF subjects. Perhaps leaner subjects or colder water temperatures would elucidate the value of body fat in females, and demonstrate a differential response with respect to females varying in percent body fat.

Adipose Tissue↗
PubMed1998

The perceptual and physiological responses of high and low fat women exposed to 5 degrees C air for 120 minutes.

The present investigation dichotomized female subjects by percentage of fat (low fat [LF] = 19.2+/-3% [n = 4] vs high fat [HF] = 29.9+/-3% [n = 4]) to elucidate the perceptual and physiological responses during acute exposure to 5 degrees C air for 120 min. Correlational analyses were used to assess the relationship between thermal sensection (TS) and differences between LF and HF groups. Significant (p < 0.01) differences existed between the groups for TS when values were pooled over time, where HF had a lower TS (5.9+/-0.6) than LF (7.9+/-0.5). Additionally, a significant (p < 0.01) main effect for time existed, where TS, when pooled over groups T5 (3.8+/-0.7) and T30 (5.4+/-0.9), was less than T60 (7.4+/-0.6), T90 (8.6+/-0.5), and T120 (9.1+/-0.4). No significant fat x time interaction was noted despite apparent perceptual differences between the groups at most of the time points. Further, the relationships between TS and percentage of fat and fat mass were either significant or exhibited strong trends toward significance at time points T5, T30, and T60. When rectal temperature (Tre) was pooled over the four time points, the fat groups differed significantly (p < 0.05); LF (-0.21+/-0.04 degrees C) exhibited a greater ATre than HF (-0.03+/-0.04 degrees C). When Tre was pooled across the fat groups, significant (p < 0.01) differences over time were detected. From these data, it appears that the modified TS scale tested may be a good marker of thermal discomfort in females exposed to the cold because perceptual differences were noted between the groups, accompanied by apparent differences in Tre between the LF and HF groups.

Adipose Tissue↗
PubMed1996

A model for analyzing the cost of main clinical events after cardiac transplantation.

Using information from the Papworth Hospital heart transplant service, a model was developed to link the main clinical events after cardiac transplantation to survival and costs. On the basis of the clinical and survival experience of 387 patients treated with triple-drug immunosuppression between 1986 and 1993, together with protocols for patient management, resource use, and costs, a 5-year Markov model with three time periods was used to simulate survival and estimate costs. The model accurately mirrors observed actuarial survival; 1- and 5-year survival rates were 81% and 65%, respectively. An average cost per patient of 26,000 pounds over 5 years (discounted at a rate of 6%) was estimated. The expense of routine care for patients accounts for the majority of the costs; a patient who remains well throughout the 5-year period would incur costs of 23,000 pounds. The sensitivity of the estimates to alternative assumptions is presented, and the way in which the model can be used to compare alternative future scenarios is explored.

Adolescent↗
PubMed1996

Measurement of health-related quality of life before and after heart-lung transplantation.

BACKGROUND: The measurement of the quality of the outcome of treatment as viewed by patients is becoming increasingly recognized as an important aspect of decision making in all health services. This major study, which set out to measure the health-related quality of life outcomes of heart and lung transplantation, developed from the experience gained in the United Kingdom and United States studies of the cost and benefits of heart transplantation in the 1980s. METHODS: The design was prospective with a cohort of patients completing a variety of generic and specific health-related quality of life questionnaires at intervals before and after heart and lung transplantation. The sample size was not prescribed; one of the aims of the project was to test the feasibility of introducing routine monitoring of health-related quality of life outcomes as an integral part of a developing transplant service. RESULTS: Before the operation, there was evidence of deterioration over time in all dimensions of the Nottingham Health Profile. In comparing Profile scores at less than 3 months before with those at 3 to 6 months after transplantation, statistically significant improvements were evident (p < 0.001). Mean scores at intervals up to 2 years after transplantation showed little change over time and compared well with those from a general population sample. Hospital Anxiety and Depression Scale scores were reduced significantly (p < 0.01) by 1 year after heart and lung transplantation. In the pretransplantation period, at least 90% of 101 patients had some level of restriction in home and leisure activities, reducing to between 2% and 24% at 1 year after transplantation. Similarly, 79 patients (78%) had chest pain, and 101 (100%) were breathless before transplantation, reducing to 54% and 39%, respectively, at 1 year after surgery; by which time, for 8 of 10 patients, the problem was occasional. CONCLUSIONS: Highly significant improvements were observed in the physical, social, and emotional dimensions of health-related quality of life of patients after heart-lung transplantation. The advantages and feasibility of combining generic and condition-specific questionnaires are shown together with the need to develop new measures with greater sensitivity to the smaller peaks and troughs of recovery.

Activities of Daily Living↗
PubMed1993

Heart to heart.

Explore the source record for details and available documents.

Continuity of Patient Care↗
PubMed1993

Prostacyclin (epoprostenol) and heart-lung transplantation as treatments for severe pulmonary hypertension.

OBJECTIVE: To determine whether epoprostenol (prostacyclin, PGI2) or heart-lung transplantation (HLT), or both improves survival of patients with severe pulmonary hypertension. DESIGN: This was a prospective study where the effects of epoprostenol were compared with conventional treatment. Also, the benefits of epoprostenol and HLT were assessed by comparing survival in this group with that of 120 patients at the Mayo Clinic before HLT and epoprostenol treatment became available. PATIENTS AND INTERVENTIONS: Forty four patients were studied; 25 received continuous epoprostenol over a four year period (mean (SD) cardiac index 1.8 (0.4) 1 min-1 m-2 and mean (SD) pulmonary artery pressure (PAP) 70 (16) mm Hg) and 19 did not (cardiac index 2.1 (0.6) 1 min-1 m-2 and PAP 64 (13) mm Hg). Ten patients underwent HLT: seven had received epoprostenol, and three had not. RESULTS: The therapeutic intervention with epoprostenol, or HLT, or both improved survival compared with the Mayo clinic patients (p = 0.05). Most of the benefit was conferred by epoprostenol, which prolonged survival twofold from a median time of eight to 17 months and doubled the changes of successful HLT. The improved survival with epoprostenol was not related to its immediate capacity to cause pulmonary vasodilation. Those patients who had limited acute pulmonary vasodilation when treated with epoprostenol showed the greatest improvement in survival. CONCLUSIONS: These preliminary results indicate that those pulmonary hypertensive patients with the poorest chance of survival can be helped by epoprostenol and by HLT.

Adult↗
PubMed1991

Prospective study of quality of life before and after coronary artery bypass grafting.

OBJECTIVES: Measurement of changes in patients' perceptions of how differing states of health affect their lives and determination of the ability of preoperative variables to predict outcome after coronary artery bypass grafting. DESIGN: Prospective study with completion of questionnaires before coronary artery bypass grafting and at three months, one year, and five years afterwards. SETTING: Regional cardiothoracic centre. PATIENTS: 100 Male patients all aged below 60 at the time of operation, who were patients of two cardiothoracic surgeons. MAIN OUTCOME MEASURES: Patients' assessment of their health state in terms of functional capacity and aspects of distress, according to the Nottingham health profile and outcome of operation in terms of changes in symptoms, working life, and daily activities determined by self completed study questionnaires before operation and at three and six months afterwards. RESULTS: Intermediate one year results are reported. The differences between the Nottingham health profile scores before operation and at three months afterwards were significantly different (p less than 0.01), indicating an appreciable improvement in general health state, and at one year compared favourably with those from a normal male population. Analysis of responses to the study questionnaire showed that 65 of 89 patients (73%) were working at one year after operation with a further seven (8%) maintaining that they were fit to work but unable to find employment. The proportion of patients complaining of chest pain fell from 90% (88/98) before grafting to 19% (17/89) at one year after coronary artery bypass grafting, when 91% (81/89) patients maintained that their condition was either completely better or definitely improved. The significant positive factors affecting return to work and home activities were working before operation, short wait for operation, absence of breathlessness, and low physical mobility score in the Nottingham health profile (all p less than 0.001). CONCLUSIONS: Improvements were evident in general health state, symptoms, and activity at three months and one year after coronary artery bypass graft surgery. Interventions likely to influence outcomes included reduction in waiting times for operation; rehabilitation initiatives; and more attention to the quality of information given to patients, their relatives, and the community.

Activities of Daily Living↗
PubMed1991

Risk factor analysis for the major hazards following heart transplantation--rejection, infection, and coronary occlusive disease.

This study demonstrates the importance of analyzing survival by cause of death in order to achieve a better understanding of the prognostic indicators involved. It further emphasizes the need for analysis of risk factors in both univariate and multivariate models, and the danger of making judgements based on premature analysis of data on follow-up after heart transplantation. Survival following transplantation is characterized by the major hazards of early death due to infection and rejection and late graft loss due to coronary occlusive disease (COD). This study summarizes the first-graft survival experience for 323 transplant patients at Papworth Hospital, and assesses a number of potential risk factors for (1) early mortality, (2) late mortality from COD, and (3) development of COD. The potential risk factors considered for all hazards are donor and recipient age, sex, blood group, and matching of these factors; donor cause of death and recipient immunosuppression; inotropic support; waiting time; preoperative diagnosis and previous cardiac surgery; ischemic time; and extubation time. In addition, for development of, and graft loss from, COD, perioperative rejection and cytomegalovirus infection; hypertension at discharge; and cholesterol, triglycerides, and lipids at two years were assessed as risk factors. Advances in immunosuppression were observed to have increased overall survival rates and decreased mortality from infection, rejection, and COD, as well as decreasing morbidity from COD. Fatal rejection was found to be more likely in female recipients, recipients over 40 years, recipients of grafts from donors over 30 years old, patients who were transplanted for valvular heart disease, and patients who waited less than three months for their transplant. Male recipients of female donor organs were more likely to lose their grafts as a result of COD. Patients older than 50 and hearts from donors older than 40 conferred a high risk of development of and loss from COD. Patients transplanted for ischemic heart disease were more likely to develop COD. High cholesterol, low HDL, high LDL, and high triglycerides at two years after transplant showed some evidence of high risk for the subsequent development of COD, although these relationships are not statistically significant at this stage. Contrary to other recent studies, cytomegalovirus infection was not found to be a risk factor for the development of COD.

Adolescent↗