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Biomedical subjects

J M Kinney

Publications and source records attributed to J M Kinney.

At least 37 records · Page 2Linked to original sources
PubMed1989

Measurement of fatty acid oxidation: validation of isotopic equilibrium extrapolation.

Measurement of whole body substrate oxidation requires prolonged isotope infusion to attain plateau specific activity (SA) of expired CO2. We have investigated in 13 hospitalized patients a technique whereby plateau 14CO2 SA is extrapolated using computer curve fitting based upon the early exponential rise. A primed-constant infusion of albumin-bound 1-14C-palmitate was continued for 260 minutes with isotope priming of the secondary bicarbonate pool at 70 minutes. Plasma free fatty acid (FFA) SA reached steady state by 40 minutes and was 91% +/- 4% (SE) of values obtained at 190 to 260 minutes. At 70 minutes 14CO2 SA reached only 44% +/- 1% of the 190 to 260 minute values, which were consistently at plateau. The predicted steady state 14CO2 SA from the 40 to 70 minute curves and the FFA oxidation rates calculated from those values were 94% +/- 2% and 102% +/- 4%, respectively, of values measured at steady state (190 to 260 minutes). The relationship between predicted and measured values approximated the line of identity for 14CO2 SA (y = 0.90x + 0.14, r = .98, P less than .001) and FFA oxidation (y = 1.02x, r = .98, P less than .001). The results suggest that FFA oxidation can be accurately calculated using a short infusion of labeled FFA without bicarbonate pool priming, thus avoiding overpriming or underpriming and possibly allowing multiple studies and diminished radioisotope exposure.

Adult↗
PubMed1989

Hassles and uplifts of giving care to a family member with dementia.

The role of daily caregiving stressors (hassles) and small caregiving satisfactions (uplifts) in the well-being of 60 family caregivers was investigated. Hassles and uplifts in 4 domains of caregiving were examined, and direct effects of hassles, uplifts on caregivers' social and psychological well-being, as well as the interactive and net effects of hassles and uplifts, were assessed. Hassles associated with care recipients' behavior demonstrated strongest associations with well-being. Women and caregivers to socially responsive yet behaviorally inappropriate care recipients reported more behavior and cognitive hassles. Uplifts associated with assistance in activities of daily living and with care recipients' behavior were related to well-being, with more uplifts related to greater, rather than less, depression. More intensely involved caregivers reported more of these uplifts. Net effects in the hypothesized direction were found, but no interactive effects emerged.

Activities of Daily Living↗
PubMed1989

Caregiving Hassles Scale: assessing the daily hassles of caring for a family member with dementia.

Examined was a scale designed to assess the daily hassles of caring for a family member with Alzheimer's Disease (AD). Primary caregivers to AD patients (N = 60) completed the Caregiving Hassles Scale on two occasions and reported on their well-being. The 42-item scale provides a reliable and psychometrically sound instrument for assessing hassles associated with assistance in basic ADL, assistance in instrumental ADL, care-recipients' cognitive status, care-recipients' behavior, and caregivers' social network.

Activities of Daily Living↗
PubMed1989

Submaximal exercise in emphysema and malnutrition at two levels of carbohydrate and fat intake.

Eight malnourished patients with emphysema (EMPH) and eight malnourished patients without evidence of lung disease (MLAN) received an infusion of 5% dextrose plus electrolytes (D5W) for 48 h and were then randomly assigned to a hypercaloric diet with either 53% of the calories as carbohydrate (CB) or with 55% as fat (FB) for the 1st wk, maintaining a constant protein intake. The alternate diet was given the following week. Ventilation and gas exchange were measured during supine cycle ergometry at 0, 12, and 25 W during the D5W, CB, and FB diet periods. At each exercise intensity, the EMPH group demonstrated a 12-15% greater O2 consumption, a lower respiratory quotient, and an O2 debt larger than that of the MALN group. Resting ventilation was higher during the CB than FB regimen in both groups of patients, but during the CB diet the EMPH group had a more exaggerated ventilatory response than the MALN group. The results demonstrate that EMPH patients have an unusual metabolic pattern during hypercaloric feeding and exercise. Furthermore in EMPH patients a FB regimen does not appear to create the additional stress on the respiratory system during exercise that is generated with a CB regimen.

Adult↗
PubMed1988

Muscle high energy phosphates in chronic peripheral vascular disease.

There is little information available concerning the alterations in skeletal muscle energy metabolism which occur in response to chronic arterial occlusive disease. In addition, the effect of arterial reconstruction on skeletal muscle energy metabolism in patients with peripheral vascular disease has not been defined. Needle biopsies were obtained from the quadriceps femoris muscle of 7 patients with aortoiliac disease and 15 patients with femoropopliteal disease and from the gastrocnemius muscle of 9 patients with femoropopliteal disease. Muscle samples were analyzed for ATP, ADP, AMP, phosphocreatine, creatine, and lactate. Eleven patients were rebiopsied after vascular reconstruction. Patients with rest pain had decreased total adenine nucleotides, energy charge potential, and ATP/ADP ratios as compared to those of controls. ATP levels were significantly decreased in muscle samples obtained distal to the arterial occlusion (i.e., quadriceps/aortoiliac, gastrocnemius/femoropopliteal) in patients with rest pain (compared with controls). ATP levels did not differ significantly from those of controls in muscle samples obtained from patients with claudication. However, energy charge potential was significantly decreased in all patients with claudication regardless of biopsy site and location of arterial occlusive disease. Normalization of muscle energy metabolism was not demonstrated following arterial reconstruction. We conclude that resting skeletal muscle energy metabolism is abnormal in patients with chronic arterial insufficiency and that progression of disease toward more severe ischemia is associated with more marked derangement. Whether the possible beneficial effects of revascularization on muscle energy metabolism are masked by the concurrent effect of injury in the early postoperative period remains to be clarified.

Adult↗
PubMed1988

Stressful situations in caregiving: relations between caregiver coping and well-being.

We examined ways in which caregivers cope with stressful caregiving situations and the relations between coping strategies and caregivers' psychosocial well-being. Respondents were 58 family caregivers to patients discharged from a rehabilitation hospital. Caregivers identified a recent stressful event in caregiving and indicated strategies used to cope with this event. After controlling for patients' impairment level, analyses indicated that caregivers engaging in more escape-avoidance coping reported greater depression and more conflict in their personal relationships. Those using more positive reappraisal demonstrated greater positive affect. Younger caregivers, many of whom were women, used more avoidance strategies. Results have implications for therapeutic interventions with family caregivers.

Activities of Daily Living↗
PubMed1988

Changes in respiratory control induced by amino acid infusions.

We compared the metabolic and respiratory responses to a 4-h infusion of an amino acid solution consisting primarily of branched-chain amino acids (BCAA) to those after a standard amino acid solution in healthy subjects. Both the BCAA solution and the standard amino acid solution increased minute ventilation (mean increase 22%, p less than .001, and 18%, p less than .01, respectively), mean inspiratory flow (19%, p less than .01, and 19%, p less than .05) and oxygen consumption (9%, p less than .02, and 5%, NS). PaCO2 decreased (mean decrease 6%, p less than .01); there was a major increase in the ventilatory response to CO2 inhalation during administration of the BCAA solution but not the standard amino acid solution. Increased plasma norepinephrine concentration (mean increase 75%, p less than .001) during the infusion of the standard amino acid solution but not the BCAA solution suggested increased sympathetic activity. The results demonstrate augmented respiratory effects of amino acid infusions by BCAA enrichment, and a dissociation between the respiratory stimulation, metabolic rate, and sympathetic activity.

Adult↗
PubMed1988

Intravenous infusion of a medium-chain triglyceride-enriched lipid emulsion.

There has been much interest in the parenteral use of medium-chain triglycerides (MCT) as a noncarbohydrate energy source. This study examines the effects of infusion iv into postabsorptive normal subjects with three doses (0.5, 1.0, 1.5 g/kg.15 h) of an emulsion containing 56% MCT and 44% long-chain triglyceride (LCT) and comparing its metabolic effect with infusions of normal saline (NS) and an emulsion containing LCT alone. There were significant increases in serum beta-hydroxybutyrate and acetoacetate 5 and 15 h after the start of the MCT-LCT infusions. Increases were seen only after 15 h of NS, while none was observed during LCT alone. Triglycerides were increased in a dose-related fashion with MCT-LCT and were increased even further with LCT alone. Glycerol increased in a dose-related fashion both during the MCT-LCT and LCT infusion beginning immediately (0.5 h) after the start of the infusion. With NS infusion, glycerol increased significantly only after 15 h of infusion. The MCT-LCT mixture and the highest LCT dose resulted in a significant (12%) increase in oxygen consumption after 5 h of infusion. There was no difference in oral glucose tolerance between the various infusions. Infusion of MCT results in significant ketogenesis and more study is needed to determine its clinical utility.

Acetoacetates↗
PubMed1988

Effects of total hip replacement and bed rest on blood rheology and red cell metabolism.

In order to better understand the pathophysiologic changes in the immediate postoperative period after total hip replacement surgery and to distinguish alterations due to the surgical operation from those due to bed rest, we examined rheologic parameters and red cell metabolism of patients before, 1 day after, and 5 to 6 days after total hip replacement and compared the results to those obtained from normal volunteers placed at bed rest for 5 days. Bed rest in the control group led to increases in hematocrit, mean corpuscular hemoglobin concentration, red cell DPG and ATP levels, and plasma concentrations of total proteins, globulins, and fibrinogen, with attendant increases in whole blood viscosity, plasma viscosity, blood viscosity, relative blood viscosity with hematocrit adjusted to 45%, and viscometric aggregation index, and the viscosity of red cell suspensions in Ringer's solution at 45% hematocrit decreased at low shear rate. The patient group, despite the postoperative lowering of their hematocrit, mean corpuscular hemoglobin concentration, and total plasma proteins and a consequent decrease of whole blood viscosity, revealed disproportionate increases in blood viscosity, relative blood viscosity, and viscometric aggregation index. These rheologic changes, which reflect an enhanced red cell aggregability, may contribute to complications of thrombophlebitis. Enforced inactivity, when superimposed on the effects of trauma, blood loss, transfusion with bank blood, and the low-flow state, would exaggerate these rheologic problems. The results suggest that management of total hip replacement patients should include hemorrheologic considerations (e.g., preoperative intentional hemodilution) and early postoperative activity.

2,3-Diphosphoglycerate↗
PubMed1988

Energy metabolism--an overview.

The most basic requirement for sustaining life is energy. Over the centuries it has been recognized that the living body is warm and begins to cool at the time of death. Referring to great scientists--Harvey, Boerhaave, Black, Priestley, Scheele, Lavoisier, Liebig, Pettenkofer, Rubner, Voit, Lusk, DuBois--the change in paradigm connected with the concepts of 'life', 'substrate intake' and 'body heat' and their underlying natural phenomena is outlined. The late 19th and early 20th century were extremely eventful in the evolution of the understanding of energy and its application to medicine. Definitions and concepts of metabolic body size, diet-induced thermogenesis, and physical activity are described. Further, metabolism adapted to starvation, postaggression metabolism and energy balance corresponding to their historical development and to the recent knowledge are elucidated.

Energy Intake↗
PubMed1988

Nitrogen and energy relationships in malnourished patients with emphysema.

The purpose of this study was to examine the impact of nutritional support on nitrogen-energy relationships and functional parameters in malnourished patients with emphysema. Malnourished patients without lung disease served as the control group. Ten ambulatory, stable patients with emphysema and six patients without lung disease received an infusion of 5% dextrose (baseline) plus electrolytes (D5W) for two days, which was followed by an enteral or a parenteral infusion of either a carbohydrate-based (CB, 53% carbohydrate) or a fat-based diet (FB, 55% fat) for 1 wk each, in a randomized cross-over design. All patients had greater than 10% weight loss. Caloric intake was set at 1.7 times the resting energy expenditure (REE) as measured during the baseline period. The REE of patients with emphysema was 23 and 27% above that of the control group during baseline and refeeding periods, respectively. The increased REE was met primarily by an increased carbohydrate oxidation. During the infusion of D5W, N balance was lower in patients with emphysema, but during repletion N balance was similar in both groups of patients. Two weeks of nutritional support with either a CB or a FB diet increased body weight, N balance, and arm muscle area and improved maximal inspiratory pressure, skeletal muscle strength, and endurance-strength (using quadriceps, hamstring, and handgrip) to a similar degree in malnourished patients with and without lung disease. In other stress states, such as infection, it has been shown that hypermetabolism, hypercatabolism, and preferential fat oxidation occur concomitantly. Patients with emphysema are unusual because, although they are hypermetabolic, they are not hypercatabolic and do not demonstrate preferential fat oxidation.

Aged↗
PubMed1987

Social networks as assets and liabilities in recovery from stroke by geriatric patients.

Interactions in the social networks of 48 elderly stroke patients were examined as factors influencing outcomes after hospital discharge. Structured interviews assessed the frequency of perceived positive and negative interactions, as well as patients' behavioral independence, time use, personal adjustment, and cognitive functioning. Negative interactions occurred less frequently than positive ones. After controlling for status at hospital discharge, negative and positive interactions differentially explained variance in morale, psychiatric symptoms, and cognitive functioning. Although negative interactions were associated with poorer morale and greater psychiatric symptoms, positive interactions were associated with less mental confusion. Patients' reporting and not reporting negative interactions did not differ significantly on a variety of social and demographic variables previously shown to predict social interactions and well-being. Findings indicate that social interactions may both impede and facilitate rehabilitation for older adults and have implications for both theories of social support and the design of therapeutic interventions.

Activities of Daily Living↗
PubMed1987

Metabolic and ventilatory responses during very low level exercise.

1. Nine male and six female healthy subjects were studied during supine bicycle exercise at workloads of 12 and 37 W; pedalling rates varied between 30 and 50 cycles/min at each workload. Measurements were made of oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE), tidal volume (VT), respiratory frequency (fR), inspiratory and expiratory time (TI, TE) and mean inspiratory flow (VT/TI) using a non-invasive canopy-computer-spirometer system. 2. At rest, males had greater values of VE, VT, TI, inspiratory duty cycle (TI/TTOT), VCO2 and VO2, and a lower fR, than females. 3. At the lower workload, VO2, VCO2, VE, VT and VT/TI increased linearly with increasing pedalling rate, whereas at the higher workload there was a decrease in VO2 and little or no change in ventilatory parameters from 30 to 50 cycles/min except for an increase in fR in females. 4. While performing supine exercise, there was an effect of pedalling rate on ventilatory and metabolic parameters at the low workload (12 W) which diminished at the higher workload (37 W). An increase in pedalling rate appears to enhance efficiency at these low workloads. 5. Differences between the sexes during exercise generally include: (a) a higher breathing frequency, (b) a greater mechanical efficiency, and (c) lower ventilatory equivalents of O2 and CO2 (VE/VO2 and VE/VCO2) during the higher workload in females than males.

Adult↗
PubMed1987

Parenteral nutrition in septic patients: effect of increasing nitrogen intake.

Metabolic effects of increasing nitrogen intake during total parenteral nutrition (TPN) were studied in nine septic patients. The patients were given 5% dextrose (D5W) for 1 d. For the next 6 d they received total parenteral nutrition (TPN), at 1.35 times resting energy expenditure (REE), containing either 191 or 366 mg N/(kg.d) Non-protein calories were divided equally between glucose and lipid emulsion. Three patients were studied on both diets (n = 6 for each diet). On the high- but not the low-N diet were significant increases in protein oxidation, blood urea N, O2 consumption, and CO2 production. TPN normalized most plasma amino acid levels but intramuscular amino acids remained unchanged. Transient positive N balance occurred during days 1-3 on the high- but not the low-N intake; on days 5-6 N balance did not differ significantly from zero on either diet and the improvement (165 mg N/[kg.d]) was the same for both diets.

Adult↗
PubMed1987

Adrenergic control of adipocyte lipolysis in trauma and sepsis.

Adipocyte lipolysis and its adrenergic control were studied in vitro from normal patients and those with trauma and sepsis. The adrenergic receptors were studied in terms of their responsiveness, a measure of the postreceptor mechanism, and their sensitivity, a measure of the receptor number or affinity. With early trauma, beta-adrenergic responsiveness and receptor number were significantly decreased. This is desensitization of the beta-receptors with down regulation and indicates increased in vivo lipolysis in early injury. After 4 days these changes had returned to normal. Early sepsis resulted in a significant increase in beta- and alpha-receptor responsiveness with beta-upregulation. This indicated hypersensitivity of the adipocyte adrenergic receptors and suggests the presence of an in vivo block of the adrenergic receptors in early sepsis. This would decrease adipocyte lipolysis. After 4 days there was a decrease in beta-receptor responsiveness in the patients with sepsis, indicating that the adrenergic receptor block was no longer present and adipocyte adrenergic stimulated lipolysis was increased.

Adipose Tissue↗
PubMed1987

Short-term effects of varying glucose intake on body composition of malnourished adult patients.

Changes in weight and body content of protein, carbohydrate, fat, total body water, intra- and extracellular water, Na, and K were estimated from balance measurements in malnourished adult patients receiving total parenteral nutrition for consecutive 8-day periods, containing either a low or high carbohydrate content. Total caloric intake was 65% of energy expenditure on the low intake and 119% on the high intake, with a difference of 54% due entirely to carbohydrate. Although there are many assumptions and approximations necessarily involved in multiple balance studies, the accuracy is sufficient to produce useful information in short-term studies of this type. It is particularly useful in looking at differences between diets, since most of the methodologic errors cancel out. The effect of the increased glucose intake was to significantly increase storage, or decrease loss, of fat, carbohydrate, protein, intracellular water, and K. Changes in Na and extracellular water varied widely among patients, but were not affected by the increase in glucose. Most of the increase in K content (83%) was associated with glycogen deposition; a much smaller amount (17%) was associated with protein deposition. Thus, the ratio of K/N deposited (15 mEq of K:1 g of N) was very different from the 3:1 ratio seen in most tissues. Changes in any one constituent of body cell mass may not, therefore, be good indicators of changes in another. Since protein is the most important active component of body cell mass, changes in body cell mass components other than N should be interpreted with caution when used as indices of nutritional therapy.

Adult↗
PubMed1987

Energy expenditure after infusion of glucose-based total parenteral nutrition.

Resting energy expenditure (REE), carbohydrate balance, and lipogenesis were calculated after administration of glucose-based total parenteral nutrition (TPN) to determine whether the thermic effect of glucose is equal to the energy cost of storing the glucose. Estimated cost of storage as glycogen (5.3%) and fat (19%) was compared with measured increases in REE. Patients with malnutrition received 5% dextrose in water and 6 days of TPN with a low (1.2 times REE, group 1) or high (2.0 times REE, group 2) level of glucose intake. Increases in REE by day 6 were 10% (group 1) and 28% (group 2). The theoretical cost of glucose storage as glycogen and fat accounted for approximately 40% of the measured increase in REE in patients in group 2. The thermic effect of TPN (derived from patients in group 1) accounted for most of the balance. The majority of the thermic effect of high levels of glucose infused with TPN can be explained on the basis of the thermic effect of TPN and glucose storage.

Body Temperature↗