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1.
A new device based on the plethysmographic measurement of body volume has been developed for the purpose of estimating human body composition. The device, the BOD POD Body Composition System, uses the relationship between pressure and volume to derive the body volume of a subject seated inside a fiberglass chamber. Derivation of body volume, together with measurement of body mass, permits calculation of body density and subsequent estimation of percent fat and fat-free mass. Critical issues which have hampered prior plethysmographic approaches are discussed. The present system's ability to measure the volume of inanimate objects was evaluated for accuracy, reliability, and linearity. Twenty successive tests of a known volume (50,039 ml) on two separate days produced values of 50,037 +/- 12.7 ml and 50,030 +/- 13.5 ml (mean +/- SD) for each day, respectively. The CV for these series were 0.025% and 0.027%. Further testing across a wide range of volumes approximating human size (25-150 1) produced the following regression equation where y = measured volume (1) and x = actual volume (1): y = 0.9998x - 0.0274, r2 = 1.0, SEE = 0.004 1. The resultant device is likely to enhance opportunities for the quick, simple and noninvasive measurement of body composition for both research and clinical applications.  相似文献   

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The human adrenal cortex is a complex endocrine organ that secretes mineralocorticoids, glucocorticoids and adrenal androgens. These steroids arise from morphologically and biochemically distinct zones of the adrenal gland. Studying secretion of these distinct steroid hormones has, in the past, required the isolation of cells from each of the adrenocortical zones. Indeed, the lack of a human adrenocortical cell line retaining the ability to produce any of the major adrenal steroid products has slowed studies on normal and abnormal adrenal function. This obstacle has now been largely overcome with the availability of H295 cells, which represents the first adrenocortical cell line to maintain the ability, under specified conditions, to produce all the adrenocortical steroids (i.e., mineralocorticoids, glucocorticoids, and adrenal androgens). Thus, H295 cells appear to act as pluripotent adrenocortical cells capable of being directed to produce each of the zone-specific steroids. The H295 cell line should prove to be of value in studying the molecular and biochemical mechanisms controlling adrenal steroidogenesis.  相似文献   

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Our investigation was designed to retest the hypothesis of the efficacy of human chorionic gonadotropin (HCG) on weight reduction in obese women in a clinic setting. We sought to duplicate the Asher-Harper study (1973) which had found that the combination of 500 cal diet and HCG had a statistically significant benefit over the diet and placebo combination as evidenced by greater weight loss and decrease in hunger. Fifty-one women between the ages of 18 and 60 participated in our 32-day prospective, randomized, double-blind comparison of HCG versus placebo. Each patient was given the same diet (the one prescribed in the Asher-Harper study), was weighed daily Monday through Saturday and was counselled by one of the investigators who administered the injections. Laboratory studies were performed at the time of initial physical examinations and at the end of the study. Twenty of 25 in the HCG and 21 of 26 patients in the placebo groups completed 28 injections. There was no statistically significant difference in the means of the two groups in number of injections received, weight loss, percent of weight loss, hip and waist circumference, weight loss per injections, or in hunger ratings. HCG does not appear to enhance the effectiveness of a rigidly imposed regimen for weight reduction.  相似文献   

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Body composition was determined by dual energy X-ray absorptiometry (DXA) scanning and classical reference methods (40K, 3H2O, and a combination of these in a four-compartment model) in 19 overweight patients with rheumatoid arthritis who underwent a 12-week weight-reducing regimen. The aim of the study was to investigate whether DXA provides a valid estimate of body composition. The results showed that weight as determined by DXA was highly significantly correlated to weight determined by scales. Furthermore, significant correlations were found in the body components (fat-free mass, fat mass) determined by DXA, 40K, 3H2O and the four-compartment model. Mean values differed slightly but significantly. With respect to changes in body composition, no significant correlations were found between any of the methods, except for the weight loss recorded by DXA and scales, and loss of fat mass (and fat free mass) estimated by 3H2O and the four-compartment model. The sparseness of correlations reflected the small changes in fat-free mass and fat mass (2.6 and 1.7 kg respectively), and the fact that changes were comparable to measurement errors of the various methods. We suggest that DXA scanning is a valid supplement for determination of body composition. Validation of DXA scanning requires new experimental in vitro investigations, which, incidentally, also applies to the classical reference methods.  相似文献   

5.
Examination of grains of chromite, subjected to varying degrees of reduction by heating chromite-graphite mixtures, using a scanning electron microscope and electronprobe microanalyser. Initially reduction of iron from chromite to form metallic iron, with a small chromium content, at the surface. Iron diffusion from within the grains to the surface with continued reduction and contraction of the core of unaltered chromite. Reduction of chromium as the main reaction when the core has disappeared and observation of a second skrinking core, this time of chromium. Increase of the chromium content of the metal phase and forming of the carbide (Cr, Fe)7C3 during this period. Reduction within the grains when the chromium core has disappeared. MgAl2O4 containing up to 6 percent chromium as final residue of the original chromite for the experimental conditions.  相似文献   

6.
OBJECTIVES: To determine the nutritional changes that occur in HIV-infected patients receiving protease inhibitor (PI) therapy and to determine the effects of PI treatment on physical functioning and health perceptions in patients with HIV infection. DESIGN: Longitudinal data analysis of 38 patients from a large Nutrition and HIV cohort. METHODS: Patients were included if they had started PI therapy after enrollment in the cohort, if they had taken the drug for at least 4 months without interruption and if data on weight, body composition and viral loads were available. RESULTS: Mean person-months of follow-up was 8.1 months before and 12.2 months after PI treatment. Weight (1.54 kg, P < 0.0001), body mass index (0.50 kg/m2, P < 0.0001), physical functioning (8.52 points, P = 0.0006) and current health perception (6.7 points, P = 0.01) increased significantly, and the daily caloric intake increase was close to significance (915.5 kJ/day, P = 0.06), after treatment with PI. Lean body mass did not change. Patients who responded to PI therapy with decreased viral load (n = 28) had significantly greater weight gain per month than non-responders. CONCLUSIONS: PI therapy of HIV infection is associated with weight gain and improvement in quality of life indices. The weight gain is mainly in fat mass, with no change in lean body mass (skeletal muscle). Optimal therapy of HIV-infected patients with weight loss may require highly active antiretroviral therapy combined with an anabolic stimulus such as exercise, anabolic steroids or human growth hormone.  相似文献   

7.
Growing expenditures in health care made it necessary to find control mechanisms to evaluate expenditure. Medical technology assessment is becoming a valuable tool to assist policymakers in controlling new medical technologies. This review deals with the increasing importance of economic evaluation as part of medical technology assessment and describes various techniques by which an economic evaluation can be performed.  相似文献   

8.
The paper deals with the hydrodynamics of artificial heart valves (AHVs) used in clinical practice. It reviews and analyzes the studies of AHV hydrodynamics, as well as the hydrodynamic beds which stimulate physiological flow through the valve. Photochronic imaging (PCI) is proposed for examination of AHV hydrodynamic characteristics under model physiological flow. The hydrodynamics of different AHVs was tested on the beds simulating blood flow through AHVs by employing PCI. PCI involved preparation of model photochronic solution that simulates blood, colour labels by using laser radiation. In the model photochronic solution, 10(-6)-10(-9)-sec laser radiation gave rise to linear colour labels whose movement was recorded by a speed camera in the flow behind the valve. The profiles of speed behind the valves, the dimensions of congestive areas, the positions of flow detachment and regurgitation flow were calculated by a speed shooting in different periods of valvular performance. PCI defined congestive areas behind the valves, the areas of closed circulations, the sizes of reversing flow areas and examined the time course of flow behind the valves as a whole. The paper is of interest for AHV designers and cardiac surgeons who apply various AHVs.  相似文献   

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Contends that the traditional conceptions of clinical psychology (CP) as centering around the treatment of individuals suffering from mental health problems are no longer adequate. The concept of human services psychology, defined as a sector of professional psychology concerned with the promotion of human well-being through the acquisition and application of psychological knowledge about the treatment and prevention of psychological and physical disorders is proposed as an alternative capable of representing both training and practice in contemporary CP and related professional specialities. A biopsychosocial model of human behavior would be the basis for a generic professional program that would be functionally rather than categorically based at the doctoral level. Such a program, based on a systems orientation, has been established at the author's university. It is suggested that human services psychology graduates will be able to confront racism, sexism, delinquency, the effects of poverty, and other social ills in an effective and cost-efficient way. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
A valid and reliable rating instrument was developed that has predictive value with regard to the ability to lose weight. The major constructs that the test was intended to measure were knowledge of the pragmatics of weight reduction and obesity and the role of fantasy in weight loss. Test items were drawn from research findings in the obesity literature and from subject matter experts in the fields of nutrition, internal medicine and clinical psychology. Test-retest reliability coefficients for the new instrument range from .64 to .95. Construct validity was ascertained through administration of the scale to groups of high school students (N=20), college nutrition students (N=30) and successful and unsuccessful dieters (Ns=28 and 20, respectively). It appears that the scale, The Dash-Brown Survey of Fact and Fiction in Weight Reduction (DBS), may be employed usefully to assess the remediability of obesity for potential dieters. The data further suggest that cognitive awareness of diet-related issues is significant in weight reduction.  相似文献   

14.
We retrospectively evaluated the frequency of renal scintigraphic abnormalities in children over 5 years admitted with a first symptomatic urinary tract infection (UTI). Among 261 children investigated, we found only 23 over 5 years having had technetium-99m-dimercaptosuccinic acid scintigraphy during the acute phase of a first UTI. Obvious scintigraphic abnormalities were detected in 14 children (15 kidneys): 12 kidneys showed focal cortical defects and 3 were small and deformed. Ultrasound was normal in 7 of the 15 kidneys with abnormal scintigraphy and in all the kidneys with normal scintigraphy. Among the 12 kidneys with focal cortical lesions, 8 kidneys returned to normal or improved considerably 2-12 months after initial work-up. In conclusion, in children over 5 years admitted with a first symptomatic UTI, the frequency of scintigraphic abnormalities is high and a strategy based only on ultrasound data would miss about 50% of the abnormal kidneys.  相似文献   

15.
Recombinant human erythropoietin (rhEPO) has now been approved for the treatment of renal anemia, anemia of prematurity, cancer-associated anemia, AIDS-associated anemia and as concomitant treatment for patients with or without autologous blood donation awaiting elective surgery. The purpose of this review is to provide an overview, based on the results of controlled studies, of the anticipated safety profile of rhEPO in various indications and to assess whether treatment with rhEPO influences the incidences of certain adverse events in these indications. The anticipated adverse events differ from indication to indication and generally reflect the corresponding underlying illness. With most indications, no relevant differences in the incidences of adverse events are observed between rhEPO and placebo-control/patients. Only in the rhEPO therapy of renal anemia is an increased incidence of hypertensive events observed in the rhEPO groups, a finding that is not reproduced with the other indications. The controlled studies forming the basis of this review provide no evidence of a relevant increase in the risk of thromboembolic events during rhEPO therapy. Overall, it may be stated that rhEPO treatment, where strictly indicated, is a safe form of therapy. As with any other treatment, the risk of side effects in certain predisposed patients must also be weighed against the desired clinical benefits.  相似文献   

16.
A new model of immediate serial recall is presented: the primacy model. The primacy model stores order information by means of the assumption that the strength of activation of successive list items decreases across list position to form a primacy gradient. Ordered recall is supported by a repeated cycle of operations involving a noisy choice of the most active item followed by suppression of the chosen item. Word-length and list-length effects are attributed to a decay process that occurs both during input, when effective rehearsal is prevented, and during output. The phonological similarity effect is attributed to a second stage of processing at which phonological confusions occur. The primacy model produces accurate simulations of the effects of word length, list length, and phonological similarity.  相似文献   

17.
The amino acid composition of the body components (carcass, hair, whole blood, and a composite of the other body tissues) were determined from a total of 81 crossbred pigs at 10 weight intervals from birth to 145 kg body weight. Body component amino acid compositions (g/100 g protein) were multiplied by their respective protein contents, resulting in calculated whole-body amino acid compositions. From 8.5 to 145 kg body weight, the amino acid compositions were similar within each body component but differed between body components. There was a higher concentration of carcass lysine, arginine, and histidine (P < .01) in the carcass, and isoleucine (P < .12), threonine (P < .15), and methionine (P < .08) tended to be higher than in the composite of the other body tissue. Whole blood was, however, higher in leucine, valine, and lysine, and hair was higher in cystine than the carcass. The relative concentration of lysine in the whole body increased to about 37 kg body weight and reached a plateau, whereas the other essential amino acids increased to 8.5 kg and then reached a plateau. Tryptophan, however, decreased from birth to 8.5 kg and then remained at a similar concentration to 145 kg body weight. Whole-body amino acid composition of pigs in our study was generally similar to that noted in other scientific reports, but there was a wide variation in amino acid values between studies.  相似文献   

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Stress mediators, CRF-41 and vasopressin known to be synthesized in, and released from the parvocellular neurosecretory neurons of the hypothalamic paraventricular nucleus (PVN) are essential to release adrenocorticotropin (ACTH) in response to stress. In addition, suckling-induced prolactin (PRL) release also depends on the integrity of the PVN. In the present study, ether stress-induced adrenocorticotrop hormone (ACTH) and prolactin (PRL) release was studied 2, 5 and 42 days after placing lesions in the hypothalamic paraventricular nucleus (PVN) of male rats. Ether-induced ACTH secretion was strongly inhibited 2 and 5 days after lesions whereas 6 weeks later the lesion induced inhibition was fading. In contrast, PVN lesion failed to inhibit ether-induced PRL release at any time studied. The results suggest that contrary to previous suggestions the peptidergic neurons essential for stress-induced PRL release are outside the PVN.  相似文献   

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