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Background: End-of-life cancer care involves multidisciplinary teams working in various settings. Evaluating the quality of care and the feedback from such processes is an important aspect of health care quality improvement. Our retrospective cohort study reviewed health care use by lung cancer patients at end of life, their reasons for visiting the emergency department (ed), and feedback from regional health care professionals. Methods: We assessed 162 Ontario patients with small-cell and relapsed or advanced non-small-cell lung cancer. Demographics, disease characteristics, and resource use were collected, and the consenting caregivers for patients with ed visits were interviewed. Study results were disseminated, and feedback about barriers to care was sought. Results: Median patient age was 69 years; 73% of the group had non-small-cell lung cancer; and 39% and 69% had received chemotherapy and radiation therapy respectively. Median overall survival was 5.6 months. In the last 3 months of life, 93% of the study patients had visited an oncologist, 67% had telephoned their oncology team, 86% had received homecare, and 73% had visited the ed. Death occurred for 55% of the patients in hospital; 23%, at home; and 22%, in hospice. Goals of care had been documented for 68% of the patients. Homecare for longer than 3 months was associated with fewer ed visits (80.3% vs. 62.1%, p = 0.022). Key themes from stakeholders included the need for more resources and for effective communication between care teams. Conclusions: Use of acute-care services and rates of death in an acute-care facility are both high for lung cancer patients approaching end of life. In our study, interprofessional and patient-provider communication, earlier connection to homecare services, and improved access to community care were highlighted as having the potential to lower the need for acute-care resources.
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Carcinoma de Pulmón de Células no Pequeñas/terapia , Neoplasias Pulmonares/terapia , Carcinoma Pulmonar de Células Pequeñas/terapia , Cuidado Terminal/normas , Anciano , Anciano de 80 o más Años , Servicio de Urgencia en Hospital , Femenino , Accesibilidad a los Servicios de Salud , Servicios de Atención de Salud a Domicilio , Humanos , Masculino , Ontario , Cuidados Paliativos , Calidad de la Atención de Salud , Estudios RetrospectivosRESUMEN
OBJECTIVE: To assess the effectiveness of controlled-release devices (CRDs) for providing zinc and for estimating faecal output in alpacas and sheep at pasture. METHODS: The study groups of 10 alpacas and 10 sheep at pasture were paired within species and allocated at random to receive by mouth either one CRD containing chromium sesquioxide designed to function for at least 21 days or two CRDs, one containing chromium sesquioxide and the other zinc oxide designed to release over a nominal 60-day period. Faecal concentrations of chromium, zinc and ash, blood and plasma concentrations of zinc and plasma activity of alkaline phosphatase (ALP) were measured over a period of 117 days after treatment. RESULTS: The mean faecal chromium excretion profiles suggested that the CRDs performed in a similar manner in both species, releasing chromium for nearly 30 days in alpacas and for slightly more than 30 days in sheep. Using a common predetermined release rate of chromium from the CRDs, the daily faecal outputs of alpacas and sheep were estimated to be 0.54 kg dry matter and 0.33 kg dry matter, respectively. The CRD containing zinc oxide provided after 1 week an estimated daily release rate of 40 mg zinc with a lifetime of between 60 and 70 days in both species. The additional zinc did not elicit a response in blood zinc concentrations or in plasma ALP activity. CONCLUSION: The CRDs were retained in the gastrointestinal tracts of the alpacas and sheep and both types functioned as expected. The CRD delivering chromium sesquioxide at a known release rate provided an estimate of faecal dry matter output over a period of almost 3 weeks and the CRD formulated to deliver supplementary zinc did so at the nominal release rate over a period of approximately 60 days in both species. These data indicated that the standard sheep CRD is applicable for use in alpacas.
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Camélidos del Nuevo Mundo/sangre , Compuestos de Cromo/administración & dosificación , Sistemas de Liberación de Medicamentos/veterinaria , Ovinos/sangre , Zinc/administración & dosificación , Animales , Compuestos de Cromo/análisis , Compuestos de Cromo/sangre , Preparaciones de Acción Retardada , Sistemas de Liberación de Medicamentos/métodos , Heces/química , Modelos Lineales , Distribución Aleatoria , Australia del Sur , Zinc/análisis , Zinc/sangreAsunto(s)
Composición Corporal , Potasio/análisis , Tamaño Corporal , Células , Estado de Salud , Humanos , Estado Nutricional , Recuento Corporal TotalRESUMEN
During construction of the whole body counter (WBC) at the Children's Nutrition Research Center (CNRC), efficiency calibration was needed to translate acquired counts of (40)K to actual grams of potassium for measurement of total body potassium (TBK) in a diverse subject population. The MCNP Monte Carlo n-particle simulation program was used to describe the WBC (54 detectors plus shielding), test individual detector counting response, and create a series of virtual anthropomorphic phantoms based on national reference anthropometric data. Each phantom included an outer layer of adipose tissue and an inner core of lean tissue. Phantoms were designed for both genders representing ages 3.5 to 18.5 years with body sizes from the 5th to the 95th percentile based on body weight. In addition, a spherical surface source surrounding the WBC was modeled in order to measure the effects of subject mass on room background interference. Individual detector measurements showed good agreement with the MCNP model. The background source model came close to agreement with empirical measurements, but showed a trend deviating from unity with increasing subject size. Results from the MCNP simulation of the CNRC WBC agreed well with empirical measurements using BOMAB phantoms. Individual detector efficiency corrections were used to improve the accuracy of the model. Nonlinear multiple regression efficiency calibration equations were derived for each gender. Room background correction is critical in improving the accuracy of the WBC calibration.
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Método de Montecarlo , Fantasmas de Imagen , Recuento Corporal Total/instrumentación , Recuento Corporal Total/normas , Adolescente , Factores de Edad , Estatura , Peso Corporal , Calibración , Niño , Preescolar , Femenino , Crecimiento y Desarrollo , Humanos , Masculino , Valores de Referencia , Adulto JovenRESUMEN
The newest version of whole body dual-energy X-ray absorptiometry (DXA) analysis software from Hologic (Discovery 12.1) is designed to enhance bone detection in smaller subjects. We re-analyzed 1127 pediatric scans (ages 1.8-18.5 yr) previously analyzed using software version 11.2. Regression analysis compared new and original results for bone area (BA), bone mineral content (BMC), bone mineral density (BMD), and DXA-derived body weight. Changes in total and regional bone results were compared with age, weight, and height. New results were highly correlated with original analyses (R2 > or = 0.9), but there were large differences at the individual subject level. The BA and BMC values increased in subjects less than 40 kg weight, resulting in a lower BMD. Original and new results were equivalent by about age 14 yr in both genders. Regional bone data showed the greatest changes in the legs. The newest software produces significant changes in bone values in subjects weighing less than 40 kg, compared with earlier versions. This effect increases with decreasing body weight. This will impact interpretation of longitudinal pediatric DXA studies, as well as existing pediatric whole body bone reference databases. Investigators must recognize which DXAsoftware version they are using, and which version produced any reference database they may use for comparison.
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Densidad Ósea/fisiología , Huesos/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador , Absorciometría de Fotón/métodos , Adolescente , Estatura/fisiología , Peso Corporal/fisiología , Huesos/fisiología , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: Our purpose was to determine glucose tolerance in pregnant women with cystic fibrosis (CF) and to relate glucose tolerance to insulin sensitivity, hepatic glucose production, and protein turnover. METHODS: We studied 8 CF women during pregnancy (CFPreg). Results were compared with those from 9 pregnant controls (PregCont) and 8 nonpregnant CF women (CFCont). The following metabolic studies were conducted: oral glucose tolerance test (OGTT), hyperinsulinemic euglycemic clamp, stable isotope infusion of [1-13C]leucine and [6,6-2H2]glucose for measurement of whole body protein turnover and hepatic glucose production (HGP), respectively. Indirect calorimetry was used to measure resting energy expenditure (REE), and food intake was measured by 3-day food journals. Fat-free mass was measured by total body potassium 40K scan. RESULTS: All but one CFPreg developed diabetes by the end of the second trimester and had significantly lower insulin secretion and more insulin resistance than PregCont. Hepatic glucose production was significantly higher and suppression by insulin was less in CF subjects, and protein breakdown was significantly higher. Insulin resistance and HGP increased during pregnancy similarly in CFPreg and PregCont groups. CONCLUSION: Pregnancy in CF is associated with decreased insulin sensitivity and high HGP, in addition to inherent decreased insulin secretion. Pregnancy in CF is also associated with increased protein turnover and less response to insulin's anticatabolic effect. These changes appear to predispose the pregnant CF women to early development of diabetes and poor weight gain.
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Fibrosis Quística/metabolismo , Complicaciones del Embarazo/metabolismo , Adulto , Diabetes Mellitus/etiología , Femenino , Gluconeogénesis/fisiología , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/metabolismo , Resistencia a la Insulina , Secreción de Insulina , Hígado/metabolismo , Embarazo , Proteínas/metabolismoRESUMEN
Ruminants have a specialised digestive system that contains anaerobic bacteria and protozoa capable of digesting the cellulosic materials that are so common in plant materials. In addition, their distinct digestive system can change the metabolism and mode of action of some nutrients, medicines or other bioactive materials when delivered orally or may provide opportunities for alternative oral dosing strategies. In particular, there is interest in administering a relatively large depot of some drugs into the rumen, which then provides for a prolonged and sustained release of small quantities of these drugs over time. Any strategy to develop a new ruminal drug delivery system must take into account the characteristics of the digestive system of ruminants and its specific bioactive application. For example, in the case of products to control parasitic infections, the development of the host's immunity against the nematodes, which can be acquired during the pasture season, must be considered; likewise, where pharmacologically active materials are used to manipulate a particular metabolic or biochemical process, one must always be aware of interactions with other processes, which might eventuate. This article reviews the necessary concepts, the issues and the challenges to construct ruminal drug delivery systems.
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Sistemas de Liberación de Medicamentos/veterinaria , Rumiantes/fisiología , Drogas Veterinarias/administración & dosificación , Drogas Veterinarias/farmacocinética , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Antihelmínticos/administración & dosificación , Antihelmínticos/farmacocinética , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades de los Bovinos/parasitología , Sistema Digestivo/anatomía & histología , Sistema Digestivo/metabolismo , Fenómenos Fisiológicos del Sistema Digestivo , Sistemas de Liberación de Medicamentos/instrumentación , Helmintiasis Animal/tratamiento farmacológico , Absorción Intestinal/efectos de los fármacos , Absorción Intestinal/fisiología , Ovinos , Enfermedades de las Ovejas/tratamiento farmacológico , Enfermedades de las Ovejas/parasitologíaRESUMEN
Childhood obesity has become a worldwide health problem. Recent studies have suggested that obese and overweight children have lower bone mass. We used dual-energy X-ray absorptiometry to examine the relation between bone mineral content (BMC) and body fatness (%Fat) in healthy children. Obese children (%Fat>30%) had higher BMC compared with age-, gender-, and ethnic-matched children with normal adiposity (%Fat<25%). When adjusted for height, these differences were less significant. We conclude obese children do not have lower whole-body BMC when compared with leaner children, even when adjusted for height, age, gender, and ethnicity.
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Peso Corporal/fisiología , Densidad Ósea/fisiología , Obesidad/fisiopatología , Tejido Adiposo/química , Composición Corporal , Niño , Etnicidad , Femenino , Humanos , Masculino , Valores de Referencia , Estados UnidosRESUMEN
OBJECTIVES: We conducted a 1-year randomized controlled trial to test the hypothesis that growth hormone (GH) improves the clinical status of children with cystic fibrosis. STUDY DESIGN: Nineteen prepubertal children were randomized to control (NonTX, n = 9) or to daily injections of GH (0.3 mg/kg/wk) (GHTX, n = 10) for 1 year. Every 3 months height, weight, and lean tissue mass were measured. Caloric intake, resting energy expenditure, pulmonary function, and respiratory muscle strength were measured every 6 months, as were total number of hospitalizations and courses of outpatient intravenous antibiotics. RESULTS: The GHTX group had significantly greater height, height velocity (NonTX = 3.8 +/- 1.4 cm/y, GHTX = 8.1 +/- 2.4 cm/y; P =.002), weight, weight velocity (NonTX = 2.1 +/- 0.9 kg/y, GHTX = 4.5 +/- 1.1 kg/y; P =.004), and change in lean tissue mass (NonTX = 2.1 +/- 1.6 kg, GHTX = 4.7 +/- 1.7 kg; P =.01) analyzed by the Student t test. The GHTX group had significant improvement in delta forced vital capacity compared with the year before study, and respiratory muscle strength improved. The number of hospitalizations and outpatient intravenous antibiotic courses significantly decreased in the GHTX group but did not change in the NonTX group. No subject had development of cystic fibrosis-related diabetes. CONCLUSIONS: Results of the first randomized controlled trial of GH treatment in cystic fibrosis indicate that GH improves growth and clinical status.
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Fibrosis Quística/tratamiento farmacológico , Hormona de Crecimiento Humana/uso terapéutico , Composición Corporal , Estatura , Peso Corporal , Niño , Fibrosis Quística/fisiopatología , Femenino , Humanos , Masculino , Estudios Prospectivos , Pruebas de Función RespiratoriaRESUMEN
The objective of this study was to develop an anthropometry-based prediction model for the assessment of bone mineral content (BMC) in children. Dual-energy X-ray absorptiometry (DXA) was used to measure whole-body BMC in a heterogeneous cohort of 982 healthy children, aged 5-18 years, from three ethnic groups (407 European- American [EA], 285 black, and 290 Mexican-American [MA]). The best model was based on log transformations of BMC and height, adjusted for age, gender, and ethnicity. The mean +/- SD for the measured/predicted in ratio was 1.000 +/- 0.017 for the calibration population. The model was verified in a second independent group of 588 healthy children (measured/predicted In ratio = 1.000 +/- 0.018). For clinical use, the ratio values were converted to a standardized Z score scale. The whole-body BMC status of 106 children with various diseases (42 cystic fibrosis [CF], 29 juvenile dermatomyositis [JDM], 15 liver disease [LD], 6 Rett syndrome [RS], and 14 human immunodeficiency virus [HIV]) was evaluated. Thirty-nine patients had Z scores less than -1.5, which suggest low bone mineral mass. Furthermore, 22 of these patients had severe abnormalities as indicated by Z scores less than -2.5. These preliminary findings indicate that the prediction model should prove useful in determining potential bone mineral deficits in individual pediatric patients.
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Huesos/fisiopatología , Modelos Lineales , Modelos Biológicos , Vigilancia de la Población , Absorciometría de Fotón/métodos , Adolescente , Factores de Edad , Estatura , Densidad Ósea , Niño , Preescolar , Estudios de Cohortes , Fibrosis Quística/fisiopatología , Dermatomiositis/fisiopatología , Femenino , Infecciones por VIH/fisiopatología , Humanos , Hepatopatías/fisiopatología , Masculino , Pediatría , Vigilancia de la Población/métodos , Valor Predictivo de las Pruebas , Síndrome de Rett/fisiopatología , Factores SexualesRESUMEN
Despite aggressive nutritional therapy, low body weight and protein catabolism are common problems in children with cystic fibrosis. Previous studies by our group and others have demonstrated improvement in both height and weight in children with cystic fibrosis who were treated with human recombinant GH, and our group has recently documented improved clinical status and lean tissue mass as well. The purpose of this report is to summarize our findings of the effect of GH on whole body protein kinetics in cystic fibrosis and to relate these findings to changes in TNF-alpha levels. We conducted a 1-yr study of 19 prepubertal children with cystic fibrosis (age 7-12 yr, all <94% of ideal body weight). Ten children were randomly assigned to take daily injections of GH (0.3 mg/kg.wk), and nine were randomly assigned to be controls. Baseline results from the subjects with cystic fibrosis were compared with results obtained from nine age- and gender-matched healthy children. Whole body protein turnover was measured at baseline and every 6 months using the stable isotope [1-(13)C]leucine and mass spectrometric analysis. Leucine rate of appearance, a measure of protein catabolism, was similar in both cystic fibrosis subgroups at baseline and was significantly higher than in the control children without cystic fibrosis. Treatment with GH resulted in a significantly lower leucine rate of appearance, as well as significantly lower leucine oxidation. The rate of protein synthesis, as calculated from these numbers, actually decreased in the cystic fibrosis subgroup. TNF-alpha levels were higher in both cystic fibrosis subgroups than in controls and correlated with leucine rate of appearance. The results of this study suggest that one reason GH improves body weight and lean tissue mass is due to improved whole body protein catabolism and improved efficiency of whole body protein kinetics.
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Fibrosis Quística/tratamiento farmacológico , Fibrosis Quística/metabolismo , Proteínas en la Dieta/metabolismo , Hormona del Crecimiento/uso terapéutico , Algoritmos , Estatura/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Niño , Femenino , Humanos , Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Cinética , Masculino , Oxidación-Reducción , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
BACKGROUND: Heritability estimates for body mass index (BMI; in kg/m(2)) in children generally have been derived from twin and adoption studies. However, BMI does not reflect total or regional body composition. OBJECTIVE: We evaluated the familial resemblance of body composition between prepubertal girls of normal weight and body fatness and their parents by using state-of-the-art technology. DESIGN: The subjects were 101 girls [mean age: 8.5 +/- 0.4 y; percentage body fat (%BF): 12-30%] and their biological parents. Weight, height, and body composition [fat mass (FM), fat-free mass (FFM), and %BF] were measured with dual-energy X-ray absorptiometry (DXA) and total body potassium (TBK). RESULTS: Weight, height, and BMI showed low-to-moderate similarity between the girls and both their parents (r = 0.29-0.44, P < 0.01). The girls' FM, FFM, and %BF were significantly related to both parents' body composition. Cross-generational equations were developed for DXA, eg, child's %BF = 12.4 + (0.158 paternal %BF) + (0.145 maternal %BF) (adjusted r(2) = 0.16, P < 0.001). Regional analysis with DXA showed that the adjusted r(2) values for the arm, trunk, and leg regions, respectively, were 0.17, 0.33, and 0.31 for lean tissue mass and 0.11, 0.14, and 0.09 for FM. TBK showed a similar relation between parents and girls (r = 0.28-0.47, P < 0.01). Significant heritability (h(2) +/- SE) was detected for BMI (0.35 +/- 0.17, P = 0.03) and %BF measured with DXA (0.50 +/- 0.12, P = 0.0001). CONCLUSION: The body composition of prepubertal girls of normal weight and body fatness is significantly related to the body composition of both biological parents.
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Composición Corporal/genética , Padre , Madres , Absorciometría de Fotón , Tejido Adiposo , Adulto , Índice de Masa Corporal , Niño , Femenino , Humanos , Masculino , Potasio/metabolismoRESUMEN
OBJECTIVE: To compare estimates of fat mass (FM), fat-free mass (FFM) and percentage body fat (%fat) by six different methods in prepubertal girls. DESIGN: Cross-sectional study. SUBJECTS: Normal-weight, multi-ethnic, prepubertal girls (age=8.5+/-0.4 y, n=101). MEASUREMENTS: Body composition was measured in each child by anthropometry (skinfold thickness using Slaughter equation), dual-energy X-ray absorptiometry (DXA), total body potassium (TBK), isotope dilution for total body water measurement (TBW), multifrequency bioelectrical impedance spectroscopy (BIS), and total body electrical conductivity (TOBEC). RESULTS: TOBEC and skinfold thickness yielded the lowest values of FM followed by DXA, TBK, TBW and BIS, with BIS giving the highest value of FM. All methods were significantly different for FFM, FM and %fat (P<0.001), except FFM by DXA and TBK. The Bland-Altman limits of agreement among the methods reveal that they are not directly interchangeable for FM, FFM, or %fat. The largest mean difference for FM was between TOBEC and BIS (-2.90 kg), whereas the smallest mean difference was between TOBEC and skinfold thickness (-0.14 kg). For FFM, the largest mean difference was also between TOBEC and BIS (2.83 kg), but the smallest mean difference for FFM was between DXA and TBK (-0.03 kg). For %fat, the mean differences were larger, -10.5% for TOBEC and BIS and+9.7% for skinfold thickness and BIS. The closest two techniques for %fat were TOBEC and skinfold thickness (mean difference of -0.62%) and DXA and TBK (-1.81%). CONCLUSIONS: We found that estimates of body composition in prepubertal 8-y-old girls are highly method-dependent and that the six methods studied (DXA, TBK, TBW, TOBEC, BIS and anthropometry) are not directly interchangeable.
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Tejido Adiposo/anatomía & histología , Composición Corporal/fisiología , Obesidad/diagnóstico , Absorciometría de Fotón , Agua Corporal/metabolismo , Niño , Estudios Transversales , Conductividad Eléctrica , Impedancia Eléctrica , Femenino , Humanos , Marcaje Isotópico , Potasio/análisis , Grosor de los Pliegues CutáneosRESUMEN
This article provides an overview of the present status of in vivo body composition methodologies that have potential for use in field studies. The methods are divided into four general categories: anthropometric indices and skinfold, body volume measurements, body water measurements including bioelectrical methods, and imaging techniques. Among the newest technologies are air-displacement plethysmography, three-dimensional photonic scanning, multifrequency bioelectrical impedance spectroscopy and whole-body tomography using electrical impedance and magnetic induction. These newer approaches are compared with the established reference methods. The advantages and limitations of each technique as a field method are presented relative to the corresponding concepts of an ideal method.
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Antropometría , Composición Corporal , Absorciometría de Fotón , Adulto , Niño , Impedancia Eléctrica , Femenino , Humanos , Imagen por Resonancia Magnética , MasculinoRESUMEN
BACKGROUND: Osteoporosis has been reported as a complication of cystic fibrosis (CF). AIMS: To measure bone mineral density (BMD) in non-acutely ill adults and bone mineral content (BMC) in children with CF. METHODS: We analysed data from 28 adults and 13 children with CF. Corticosteroid use was minimal for the year prior to study in both groups. Dual x ray absorptiometry was used to measure total body and regional bone mineral density in adults. In children, whole body BMC was measured. Lean tissue mass (LTM) was also measured in all subjects. There were two control groups: A (matched for LTM and height, in addition to age and gender); and B (matched for age and gender only). RESULTS: There was no difference in whole body or regional BMD density between adult CF patients and control A subjects. Both whole body and regional BMD were significantly lower in adult CF patients than in control B subjects. Total body BMD was correlated with body mass index, LTM, and percent fat in both CF and control subjects. There was no significant correlation between total body BMD or regional BMD and either NIH clinical status scores, or pulmonary function tests in adults. There was no difference in total body BMC between CF children and control A subjects. Total body BMC was significantly lower in CF children than in control B subjects. There was no correlation between pulmonary function results and BMC in children. CONCLUSION: Osteopenia and osteoporosis in CF may be caused more by malnutrition and chronic use of intravenous or oral corticosteroids than by a CF related inherent defect in BMD. Appropriate "normal" data should be selected when determining whether or not osteoporosis is present in a CF patient.
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Densidad Ósea , Fibrosis Quística/fisiopatología , Absorciometría de Fotón , Adulto , Índice de Masa Corporal , Estudios de Casos y Controles , Niño , Fibrosis Quística/sangre , Fibrosis Quística/tratamiento farmacológico , Estradiol/sangre , Estrógenos/sangre , Femenino , Fémur/fisiología , Glucocorticoides/uso terapéutico , Humanos , Masculino , Columna Vertebral/fisiología , Testosterona/sangreRESUMEN
BACKGROUND: Early diagnostic efforts and advances in multidrug therapy have considerably prolonged the survival time of children infected perinatally with HIV. Despite these advances, few studies have addressed calcium status and bone growth in HIV-infected children. OBJECTIVE: Our objective was to examine the effect of HIV infection on calcium status and bone growth in children. DESIGN: We measured calcitropic hormones, urinary calcium excretion, bone mineral content, and body composition in 19 young girls aged 9.2 +/- 2.6 y (range: 5.9-15.2 y) who were infected perinatally with HIV. RESULTS: Serum concentrations of 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and parathyroid hormone concentrations were elevated above normal ranges in 25% and 12% of these girls, respectively. Urinary calcium excretion normalized for creatinine excretion was also elevated (Ca/Cr >0.18) in 17% of these children despite suboptimal calcium intakes (679 +/- 437 mg/d). Total-body bone mineral content, measured with the use of dual-energy X-ray absorptiometry, averaged 845.1 +/- 279.0 g and was on average 2.7 z scores below age- and race-matched values reported in non-HIV-infected healthy girls. Significant positive correlations were found between an indirect marker of bone resorption in urine (N:-telopeptide) and 1,25(OH)2D (P < 0.02, r2 = 0.586, n = 9), and between serum N-telopeptide and total alkaline phosphatase (P < 0.001, r2 = 0.541, n = 17), suggesting that calcium insufficiency may be increasing bone resorption in this group. CONCLUSIONS: Young girls with HIV infection had low bone mass and evidence of calcium insufficiency. Nutritional counseling of children with HIV infection should emphasize adequate calcium intakes because of the importance of this age period in bone mineral acquisition.
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Densidad Ósea/fisiología , Calcitriol/sangre , Calcio/análisis , Infecciones por VIH/complicaciones , Hormona Paratiroidea/sangre , Absorciometría de Fotón , Adolescente , Fenómenos Fisiológicos Nutricionales de los Adolescentes , Población Negra , Composición Corporal , Desarrollo Óseo , Resorción Ósea , Calcio/deficiencia , Niño , Fenómenos Fisiológicos Nutricionales Infantiles , Preescolar , Creatinina/orina , Femenino , Humanos , Recuerdo Mental , Atención Perinatal , Población BlancaRESUMEN
BACKGROUND: Obesity has been increasing dramatically in recent years among children, particularly African-American girls. Total-body electrical conductivity (TOBEC) is a simple way to measure body fat with minimal risk. OBJECTIVE: This study compared the agreement between the percentage of fat mass (%FM) predicted using two TOBEC equations with %FM measured by a four-component model in 73 Caucasian and 41 African-American girls. DESIGN AND MEASUREMENTS: %FM predicted using the TOBEC equations was compared with %FM from the four-component model based on measurements of body density, body water and bone mineral content. RESULTS: Analyses by linear regression analysis and by the Bland and Altman methods comparison procedure showed that the equation using the square root of the TOBEC zero-order Fourier coefficient and the subject's height yielded more accurate and more reproducible %FM, regardless of race, than the TOBEC linear equation, which was based on the zero-, first- and second-order Fourier coefficients. The Bland and Altman comparison further revealed that the accuracy and limits of agreement of the TOBEC linear equation were related to body fatness among the Caucasian girls. The relationship, however, disappeared when prepubescent girls and a girl with low %FM were excluded from the analysis. CONCLUSIONS: The TOBEC square root equation with adjustment for body geometry and length is recommended for use in adolescent girls, as it yielded better agreement with the criterion method. However, further validation of the TOBEC instrumentation for estimating body fat in prepubescent children and children with low body fat is warranted.
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Tejido Adiposo , Negro o Afroamericano/estadística & datos numéricos , Composición Corporal , Impedancia Eléctrica , Modelos Estadísticos , Obesidad/etnología , Población Blanca/estadística & datos numéricos , Absorciometría de Fotón , Adolescente , Niño , Femenino , Humanos , Reproducibilidad de los Resultados , Estados Unidos/epidemiologíaRESUMEN
We compared the effects of supplementing either animal plasma or extruded soy protein in the diet based on the efficiency of dietary protein utilization for lean tissue growth in early-weaned pigs. Twenty-four 14-d-old pigs (4 kg body weight) were pair-fed (per kg body weight) either a control diet containing extruded soy protein (C; n = 12) or a diet with 10% animal plasma (P; n = 12) for 24 d. During the 24 days, protein intake was not different, yet mean daily body weight gains (+23%) and food conversion efficiencies (expressed as the ratio of body weight gain to protein intake) (+19%) were greater (P < 0.05) in the P group than in the C group. Lean body mass measured after 24 d, using both dual-energy X-ray absorptiometry and total body potassium analysis, was significantly (P < 0.05) greater (approximately 16%) in P than in C pigs. The circulating urea concentrations were 40% lower (P < 0.05) in P than in C pigs. Our results demonstrate that supplementing early-weaned pig diets with animal plasma rather than extruded soy protein increased the efficiency of dietary protein use for lean tissue growth and that this response is mediated in part by decreased amino acid catabolism.
Asunto(s)
Proteínas en la Dieta/sangre , Proteínas de Soja/metabolismo , Porcinos/crecimiento & desarrollo , Alimentación Animal , Animales , Composición Corporal , Femenino , Masculino , Aumento de PesoRESUMEN
BACKGROUND: Although skinfold-thickness equations are widely used to estimate body fat, their accuracy in a biracial population of female adolescents has not been established. OBJECTIVE: We undertook this study to determine the agreement between 8 widely used skinfold-thickness equations and a 4-compartment criterion model in predicting the percentage body fat of 72 white and 40 African American girls aged 13.0 +/- 1.9 y. DESIGN: The biceps, triceps, suprailiac, subscapular, thigh, calf, and abdominal skinfold thicknesses of the subjects were measured with skinfold calipers and the buttocks circumference with a metal tape. The percentage fat mass (%FM) predicted by using each skinfold-thickness equation was compared with the criterion value calculated by the 4-compartment model on the basis of measurements of body density, body water, and bone mineral content. RESULTS: When the racial groups were analyzed separately, the Bland-Altman analysis indicated that the quadratic equations agreed most closely with the 4-compartment model's measurement of %FM. Agreement of the other equations varied with body fatness. CONCLUSIONS: The quadratic equation of Slaughter et al is recommended for population studies in female adolescents because of its accuracy and simplicity. However, an individual %FM can be over- or underestimated by approximately 10% when this skinfold-thickness equation is used.