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Biomedical subjects

C Davis

Publications and source records attributed to C Davis.

At least 433 records · Page 24Linked to original sources
PubMedDate not supplied

Excessive exercise and weight preoccupation in women.

A group of adult women (n = 351) were assessed on a number of psychological, behavioral, and body composition measures including weight preoccupation and leisure-time physical activity participation. The purpose of the study was twofold. It was intended (a) to investigate whether excessive exercises have specific characteristics in common other than that they exercise a great deal and (b) to identify the degree of relationship between exercising and weight preoccupation, and the extent to which those classified as excessive on either dimension have psychological characteristics in common. Results indicated that excessive exercisers reported greater body satisfaction and body focus, were less emotionally reactive (neurotic), and more extraverted than nonexercisers. Although some researchers have reported psychological similarities between excessive exercisers and women with eating disturbances, our data do not entirely support that point of view. While excessive exercise was associated with a decrease in body dissatisfaction and was negatively related to neuroticism, weight preoccupation was associated with an increase in body dissatisfaction and was positively related to neuroticism. However, one characteristic that both excessive groups shared, and that significantly differentiated them from their nonexcessive counterparts, was their high level of body focus. These findings led us to test the body focus x neuroticism interaction on both exercise participation and weight preoccupation. Results indicated a highly significant interaction on weight preoccupation. However, only the two main effects were significantly related to exercise.

Adult↗
PubMedDate not supplied

Growth hormone response to diazepam, clonidine and glucagon in patients with epilepsy.

The differing actions of phenytoin, carbamazepine and sodium valproate on growth hormone release were studied in 20 patients with recently diagnosed epilepsy using diazepam, clonidine and glucagon as stimulatory tests of growth hormone response. The results are compared with the growth hormone response obtained pre treatment, and those from 20 control patients and 11 patients with chronic treated epilepsy. There was a reduction in growth hormone response to diazepam in both treated and untreated patients with epilepsy compared to controls. Treatment with phenytoin resulted in a significant increase in growth hormone release after diazepam and glucagon, whilst sodium valproate reduced the growth hormone response to diazepam.

Adult↗
PubMedDate not supplied

The prevalence of high-level exercise in the eating disorders: etiological implications.

There is increasing evidence both from animal experimentation and from clinical field studies that physical activity can play a central role in the pathogenesis of some eating disorders. However, few studies have addressed the issue of prevalence or whether there are different rates of occurrence across diagnostic categories, and the estimates that do exist are not entirely satisfactory. The present study was designed to conduct a detailed examination of the physical activity history in patients with anorexia nervosa (AN) and bulimia nervosa (BN) both during and prior to the onset of their disorder. A sample of adult patients and a second sample of adolescent AN patients took part in the study. A series of chi-square analyses compared diagnostic groups on a number of variables related to sport/exercise behaviors both premorbidly and comorbidly. Data were obtained by means of a detailed structured interview with each patient. We found that a large proportion of eating disorder patients were exercising excessively during an acute phase of the disorder, overexercising is significantly more frequent among those with AN versus BN, and premorbid activity levels significantly predict excessive exercise comorbidity. These findings underscore the centrality of physical activity in the development and maintenance of some eating disorders. They also have important clinical implications in light of the large proportion of individuals who combine dieting and exercise in an attempt to lose weight, and the increasing recognition of the adverse effects of strenuous physical activity in malnourished individuals.

Adolescent↗
PubMedDate not supplied

Personality factors and weight preoccupation: a continuum approach to the association between eating disorders and personality disorders.

OBJECTIVE: Evidence shows a high comorbidity of eating disorders and some forms of personality disorder. Adopting a dimensional approach to both, our study explored their connection among a non-clinical sample. METHOD: 191 young women completed personality scales of general neuroticism, and of borderline, schizotypal, obsessive-compulsive, and narcissistic (both adjustive and maladaptive) traits. Weight preoccupation (WP), as a normal analogue of eating disorders, was assessed with scales from the Eating Disorder Inventory, and height and weight measured. The data were analysed with multiple regression techniques, with WP as the dependent variable. RESULTS: In low to normal weight subjects, after controlling for the significant influence of body mass, the specific predictors of WP in the regression model were borderline personality and maladaptive narcissism, in the positive direction, and adjustive narcissism and obsessive-compulsiveness in the negative direction. In heavier women, narcissism made no contribution--nor, more significantly, did body mass. CONCLUSIONS: Patterns of association between eating pathology and personality disorder, especially borderline and narcissism, can be clearly mapped across to personality traits in the currently non-clinical population. This finding has important implications for understanding dynamics of, and identifying individuals at risk for, eating disorders.

Adolescent↗
PubMedDate not supplied

Vascular complications of coronary interventions.

Vascular complications such as hematoma, pseudoaneurysm, and arteriovenous fistula that occur after intracoronary or intracardiac procedures are responsible for considerable morbidity and some mortality. In addition, many of these complications result in considerable increases in hospital stays and in the costs associated with the procedures. A number of risk factors for vascular complications after coronary interventions have been identified. They include excessive anticoagulation, use of femoral sheaths for extended lengths of time, multiple interventions during the same hospitalization, catheter insertion in the superficial or deep femoral artery larger catheter size, and complex interventions such as stent deployment or atherectomy. Specific interventions have been identified that help to decrease procedural risk, improve early detection and prompt treatment of the vascular injury, and prevent long-term disability.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

The eating disorders as addiction: a psychobiological perspective.

A number of theories have been proposed to explain the substantial comorbidity between the eating disorders and the substance-related disorders. Among them is the claim that self-starvation--exacerbated by excessive exercising--is itself an addiction to the body's endogenous opioids. While efforts have also been made to identify an "addictive personality," attempts to establish whether eating-disordered patients share these characteristics have met with mixed success. The present study was designed to determine the degree to which anorexic and bulimic patients display addictive personality characteristics, and whether these traits are useful in predicting the severity of the patient's weight preoccupation and their degree of excessive exercising. Results confirmed that both anorexic and bulimic patients had high scores on the Addiction Scale of the Eysenck Personality Questionnaire, and that addictiveness and obsessive-compulsiveness were related simultaneously to weight preoccupation and excessive exercising in both patient groups. Findings are discussed within the framework of the auto-addiction opioid theory, and they highlight the similarities and differences in the personality structure of the eating-disorder subtypes.

Adaptation, Psychological↗
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Upright bicycle and treadmill stress echocardiography techniques and technical hints for the sonographer.

Stress echocardiography is an extremely valuable diagnostic tool that has gained widespread acceptance and popularity. The methods described here are by no means the only way to carry out stress echocardiography. The intent of this paper is to describe the way we accomplish stress echocardiography at Indiana University. Our methods have worked quite well and to date, and we do not plan to significantly change our protocols. One should not be discouraged when first learning how to perform stress echocardiography. Do not expect that stress echo will be easy to master. As with other echocardiographic modalities, a learning curve exists for the sonographer as well as for the interpreting physician; however, with practice, stress echocardiography will become another invaluable examination in your echocardiographic repertoire.

Analog-Digital Conversion↗
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Gaulin homogenization: a mechanistic study.

Free radical-based oxidation has been detected in the normal operating regime of the Gaulin homogenizer, demonstrating that cavitation occurs in this important industrial bioprocessing equipment. Free radical generation is suppressed by imposition of back pressure, proving that such cavitation occurs in the impingement section. The calculated value of the cavitation number is consistent with submerged jet cavitation, wherein a high-speed jet exiting from the valve gap accelerates fluid in the impingement region, creating the vacuum conditions for cavitation. Using polysaccharides as a model shear-sensitive compound, their breakage pattern in the homogenizer was characterized by molecular size and polydispersity and compared to those of fluid shear flows in capillary tubes and cavitating flow from a sonic horn. The results indicate that breakage occurs primarily by fluid shear, although a contribution by cavitation is also apparent when back pressure is applied. Because biological molecules can readily react with free radicals and the alterations caused thereby are subtle in nature, a thorough evaluation of the impact of free radicals in upstream homogenization is warranted.

Biopharmaceutics↗
PubMedDate not supplied

The fetid foot: lower-extremity infections in patients with diabetes mellitus.

Infections of the lower extremities in patients with diabetes mellitus have been attributed to Staphylococcus aureus and other facultatively anaerobic bacteria. However, a review of 30 consecutive diabetics who required surgery for lower-extremity infections revealed that 17 had mixed infections due to both obligate and facultative anaerobes; only six had infections due to S. aureus. Mixed infections often had characteristics of anaerobic suppuration and responded poorly to therapy. Patients with mixed infections required more operations than did those with staphylococcal infections, and their surgical wounds healed more slowly. Seven patients had infections with mixed enteric bacteria (neither anaerobes nor S. aureus), and their response to therapy was intermediate between that of the patients with mixed anaerobic infections and those with staphylococcal infections. Nine additional patients with mixed anaerobic infections were treated with cefoxitin; three required amputations at a level above the ankle, but six patients improved and required only limited surgery that preserved foot function. Bacteroides fragilis was the anaerobe isolated most often. Cefoxitin (less than or equal to 20 micrograms/ml) inhibited all of the anaerobes isolated from the nine patients and 97% of an additional 135 consecutive clinical isolates of B. fragilis; 98% of 54 strains of Bacteroides oralis and all of 34 strains of Bacteroides melaninogenicus were also inhibited. These in vitro results and the results of our clinical study show that cefoxitin is a promising antibiotic for therapy of foot infections due to a mixed flora of anaerobes in diabetics.

Aged↗
PubMedDate not supplied

Obsessionality in anorexia nervosa: the moderating influence of exercise.

OBJECTIVE: Research has confirmed substantial links between OCD and AN. Not only are there psychopathological similarities between the two syndromes, but a marked neurochemical correspondence. Extensive exercising is a common feature of AN and also has relevance in its links with OCD. There is evidence from the exercise-induced weight-loss syndrome in animals that exercise and caloric restriction, in combination, tend to increase serotonergic activity in a synergistic manner. This syndrome has been proposed as a valid model of OCD as well as for AN. To date, little research has directly tested this theory in the human condition. METHOD: Fifty-three AN patients were categorized as high-level exercisers (N = 22) or moderate/nonexercisers (N = 31) based on the frequency of their physical activity over the year before assessment. RESULTS: Exercisers scored significantly higher on a measure of OC personality characteristics, OC symptomatology, and perfectionism--a personality factor associated with the development of Obsessive-Compulsive Personality Disorder. On the other hand, there were no group differences on other salient eating disorder characteristics such as body esteem, self-esteem, or weight preoccupation. There were also no differences in degree of emaciation as indicated by Body Mass Index. CONCLUSIONS: Findings suggest that among AN patients obsessional personality characteristics are linked to high-level exercising, and that exercising is associated with a greater degree of OC symptomatology. Results are discussed in the context of current theories of AN, OCD, and some biological mechanisms.

Adult↗
PubMedDate not supplied

Longitudinal evaluation of bone mineral density in children receiving chemotherapy.

PURPOSE: Some children who survive a childhood malignancy have diminished bone mineral density (BMD). The purpose of this study is to assess when, and perhaps why, this problem develops. PATIENTS AND METHODS: BMD was longitudinally monitored in 37 children for a minimum of 1 year (mean, 23.4 months; range, 12 to 41 months) during and, in some cases, after chemotherapy. Evaluations included serum analyses (vitamin D, calcium, and alkaline phosphatase), assessment of calcium intake, and measures of growth and nutrition (height, weight, and skinfolds). RESULTS: BMD was already diminished at the start of treatment in some patients; 6 of 13 patients (46%) had a BMD z score in the hip or spine of < -1.0. However, only 1 patient (8%) was < -2.0. Most patients did not have a significant drop in BMD z scores during chemotherapy, but one in four did decrease at least 0.5 standard deviations. Age greater than 10 years, a drop in height z score, and treatment with cranial irradiation correlated with a drop in BMD z scores during treatment. In the year immediately after completion of chemotherapy, no consistent "catch-up" was observed in BMD z scores. CONCLUSIONS: In some patients, BMD z scores are diminished at the time of diagnosis and a drop may occur during treatment in others. Multiple factors related to the disease process and treatment likely contribute to these observations. Cranial irradiation, perhaps by impacting on growth hormone homeostasis, is one such factor. Fortunately, most survivors of a childhood malignancy will not have large deficits in BMD later in life.

Adolescent↗
PubMedDate not supplied

Intestinal placement of pH-sensing nasointestinal feeding tubes.

Intestinal access for enteral nutrition can be achieved by spontaneous intestinal nasogastric tube passage or by endoscopic, fluoroscopic, or surgical placement methods. Each of these methods has limitations that may compromise clinical utility. pH-sensing nasointestinal feeding tubes allow active placement with minimal equipment and expertise; however, this method requires an acidic gastric pH. We sought to determine whether antiulcer regimens used at our institution would preclude intestinal pH-sensing tube placement. Twenty-five patients had 25 (81%) successful intestinal placements in 31 attempts. Observed pH values and calculated pH changes were compared within and between successful and unsuccessful groups by using a Student's t test. Initial, lowest, and final pH values did not differ significantly between groups. The pH change initial-to-lowest (4.7 +/- 0.18 vs 3.6 +/- 0.59, p < .03) and lowest-to-final (5.0 +/- 0.18 vs 3.0 +/- 0.47, p < .0001) differed significantly between groups, whereas the pH change initial-to-final did not. Cost analysis of endoscopic ($782), fluoroscopic ($341 to $382), spontaneous ($167 to $212), and pH-sensing ($162) methods revealed 3% to 79% savings when the pH-sensing placement method was used. We conclude that the antiulcer therapies used in our patient population did not preclude intestinal pH-sensing tube placement. If the pH changes from initial-to-lowest and lowest-to-final were greater than 4, successful intestinal placement occurred in 91% of attempts. Finally, the method was cost-effective at our institution.

Anti-Ulcer Agents↗
PubMedDate not supplied

Improving chronic illness care: translating evidence into action.

The growing number of persons suffering from major chronic illnesses face many obstacles in coping with their condition, not least of which is medical care that often does not meet their needs for effective clinical management, psychological support, and information. The primary reason for this may be the mismatch between their needs and care delivery systems largely designed for acute illness. Evidence of effective system changes that improve chronic care is mounting. We have tried to summarize this evidence in the Chronic Care Model (CCM) to guide quality improvement. In this paper we describe the CCM, its use in intensive quality improvement activities with more than 100 health care organizations, and insights gained in the process.

Chronic Disease↗