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Levitt DG, Heymsfield SB, Pierson RN, Shapses SA, Kral JG. Physiological models of body composition and human obesity. Nutr Metab (Lond) 2009; 6:7. [PMID: 19220892 PMCID: PMC2649131 DOI: 10.1186/1743-7075-6-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Accepted: 02/16/2009] [Indexed: 11/10/2022] Open
Abstract
Correction to Levitt DG, Heymsfield SB, Pierson Jr RN, Shapses SA, Kral JG: Physiological models of body composition and human obesity. Nutrition & Metabolism 2007, 4:19
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Hull H, He Q, Thornton J, Javed F, Wang J, Pierson RN, Gallagher D. iDXA, Prodigy, and DPXL dual-energy X-ray absorptiometry whole-body scans: a cross-calibration study. J Clin Densitom 2009; 12:95-102. [PMID: 19028125 PMCID: PMC2661815 DOI: 10.1016/j.jocd.2008.09.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 09/23/2008] [Accepted: 09/25/2008] [Indexed: 11/26/2022]
Abstract
PURPOSE Total body fat, lean, and bone mineral content (BMC) in addition to regional fat and lean mass values for arms, legs, and trunk were compared across a pencil-beam (Lunar DPXL) and 2 fan-beam (GE Lunar Prodigy and GE Lunar iDXA) dual-energy X-ray absorptiometry (DXA) systems. METHODS Subjects were a multiethnic sample of 99 healthy adult males (47%) and females (mean+/-SD: age, 46.3+/-16.9 yr; weight, 73.4+/-16.6 kg; height, 167.6+/-9.7 cm; body mass index, 26.0+/-5.2 kg/m2) who had whole-body scans performed within a 3-h period on the 3 systems. Repeated measures ANOVA was used to test the null hypothesis that the mean values for the 3 systems were equal. Translation equations between the methods were derived using regression techniques. RESULTS Bone mineral content (BMC): For both genders, total BMC by iDXA was lower (p<or=0.004) than the other systems. Lean: for males, iDXA was lower (p<or=0.03) than the other systems for total, trunk, and arms. For females, DPXL estimated higher (p<0.001) lean mass compared with the other systems for total, trunk, and arms, but iDXA estimated greater legs lean mass. For both genders, all DPXL mean values were greater than Prodigy mean values (p<0.001). Fat: in females, all the 3 systems were different from each other for total, trunk, and legs (p<or=0.04). For arms, DPXL and iDXA were higher than Prodigy (p<0.0004). For males, DPXL was less (p<0.001) for total body, trunk, and legs compared with the other 2 systems and greater than Prodigy only for arms (p<0.0007). These data were used to derive translation equations between systems. For several measurements, the differences between systems were related to gender. CONCLUSION For estimation of BMC and body composition, there was high agreement between all DXA systems (R2=0.85-0.99). Even so, cross-calibration equations should be used to examine data across systems to avoid erroneous conclusions.
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Silva AM, Heymsfield SB, Gallagher D, Albu J, Pi-Sunyer XF, Pierson RN, Wang J, Heshka S, Sardinha LB, Wang Z. Evaluation of between-methods agreement of extracellular water measurements in adults and children. Am J Clin Nutr 2008; 88:315-23. [PMID: 18689366 PMCID: PMC2752354 DOI: 10.1093/ajcn/88.2.315] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Extracellular water (ECW), a relevant molecular level component for clinical assessment, is commonly obtained by 2 methods that rely on assumptions that may not be possible to test at the time the measurements are made. OBJECTIVE The aim of the current study was to evaluate the degree of agreement between ECW assessment by the sodium bromide dilution (ECW(NaBr)) and total body potassium (TBK; whole-body (40)K counting) to total body water (TBW; isotope dilution) methods (ECW(TBK-TBW)) in an ethnically mixed group of children and adults. DESIGN ECW was measured with the ECW(NaBr) and ECW(TBK-TBW) methods in 526 white and African American males and females (86 nonobese children, 193 nonobese adults, and 247 obese adults). Fat mass was assessed with dual-energy X-ray absorptiometry. Multiple regression analysis was used to examine the variables related to between-ECW method differences. RESULTS Significant but generally small group mean (+/-SD) differences in ECW were found in the obese adults (1.28 +/- 2.54 kg) and children (-0.71 +/- 1.78 kg). The magnitude of the differences was related to mean ECW in obese adults, children, and nonobese adults, and the relations between these variables were modified by sex for nonobese adults. ECW differences were also dependent on age, weight, sex, and race or on interactions between these variables. CONCLUSIONS Overall, although good between-method agreement was found across the 3 groups, the degree of agreement varied according to subject characteristics, particularly at the extremes of ECW and body weight. We advance a possible mechanism that may link subject characteristics with the degree of agreement between ECW measurement methods and their underlying assumptions.
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Poston RS, Gu J, White C, Jeudy J, Nie L, Brown J, Gammie J, Pierson RN, Romar L, Griffith BP. Perioperative management of aspirin resistance after off-pump coronary artery bypass grafting: possible role for aprotinin. Transfusion 2008; 48:39S-46S. [PMID: 18302581 DOI: 10.1111/j.1537-2995.2007.01575.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Aspirin is the only drug proven to reduce saphenous vein graft (SVG) failure, but aspirin resistance (ASA-R) frequently occurs after off-pump coronary artery bypass grafting (OPCAB). The factors, mechanism, and best means for preventing and/or treating ASA-R have not been established. This study hypothesizes that thrombin production during OPCAB stimulates this acquired ASA-R. STUDY DESIGN AND METHODS A nonrandomized prospective cohort of 255 patients (n=465 SVG) who underwent OPCAB with varied use of aprotinin (21%) and different SVG preparation techniques (standard, 56% vs. low-pressure, 44%) was analyzed. A surplus SVG segment was obtained to assess endothelial integrity. ASA-R was determined at baseline, after surgery, and on Days 1 and 3 by three assays. The effects of aprotinin on thrombin responsiveness were analyzed by means of whole-blood aggregometry, SVG tissue factor (TF) activity, and transcardiac thrombin production (i.e., F1.2 levels in aorta versus coronary sinus). SVG patency was assessed on Day 5 with multichannel CT angiography. RESULTS ASA-R developed in 42 percent of patients after OPCAB. Multivariate analysis showed that ASA-R, endothelial integrity, and target size independently predicted early SVG failure. Aprotinin use was associated with: 1) reduced postoperative ASA-R (15%); 2) decreased platelet (PLT) response to thrombin; 3) reduced TF activity within SVG segments; 4) decreased transcardiac thrombin gradient; and 5) improved SVG patency. CONCLUSION ASA-R is a common post-OPCAB event whose frequency may be reduced by intraoperative use of aprotinin, possibly via TF and thrombin suppression. Improved perioperative PLT function after OPCAB may also inadvertently enhance the clinical relevance of these potential antithrombotic effects.
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Freedman DS, Wang J, Thornton JC, Mei Z, Pierson RN, Dietz WH, Horlick M. Racial/ethnic differences in body fatness among children and adolescents. Obesity (Silver Spring) 2008; 16:1105-11. [PMID: 18309298 DOI: 10.1038/oby.2008.30] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Although the BMI is widely used as a measure of adiposity, it is a measure of excess weight, and its association with body fatness may differ across racial or ethnic groups. OBJECTIVE To determine whether differences in body fatness between white, black, Hispanic, and Asian children vary by BMI-for-age, and whether the accuracy of overweight (BMI-for-age>or=Centers for Disease Control and Prevention (CDC) 95th percentile) as an indicator of excess adiposity varies by race/ethnicity. METHODS AND PROCEDURES Total body dual-energy X-ray absorptiometry (DXA) provided estimates of %body fat among 1,104 healthy 5- to 18-year-olds. RESULTS At equivalent levels of BMI-for-age, black children had less (mean, 3%) body fatness than white children, and Asian girls had slightly higher (1%) levels of %body fat than white girls. These differences, however, varied by BMI-for-age, with the excess body fatness of Asians evident only among relatively thin children. The ability of overweight to identify girls with excess body fatness also varied by race/ethnicity. Of the girls with excess body fatness, 89% (24/27) of black girls, but only 50% (8/16) of Asian girls, were overweight (P=0.03). Furthermore, the proportion of overweight girls who had excess body fatness varied from 62% (8/13) among Asians to 100% (13/13) among whites. DISCUSSION There are racial or ethnic differences in body fatness among children, but these differences vary by BMI-for-age. If race/ethnicity differences in body fatness among adults also vary by BMI, it may be difficult to develop race-specific BMI cut points to identify equivalent levels of %body fat.
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Wang Z, Heymsfield SB, Pi-Sunyer FX, Gallagher D, Pierson RN. Body composition analysis: Cellular level modeling of body component ratios. INTERNATIONAL JOURNAL OF BODY COMPOSITION RESEARCH 2008; 6:173-184. [PMID: 21643542 PMCID: PMC3106445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
During the past two decades, a major outgrowth of efforts by our research group at St. Luke's-Roosevelt Hospital is the development of body composition models that include cellular level models, models based on body component ratios, total body potassium models, multi-component models, and resting energy expenditure-body composition models. This review summarizes these models with emphasis on component ratios that we believe are fundamental to understanding human body composition during growth and development and in response to disease and treatments. In-vivo measurements reveal that in healthy adults some component ratios show minimal variability and are relatively 'stable', for example total body water/fat-free mass and fat-free mass density. These ratios can be effectively applied for developing body composition methods. In contrast, other ratios, such as total body potassium/fat-free mass, are highly variable in vivo and therefore are less useful for developing body composition models. In order to understand the mechanisms governing the variability of these component ratios, we have developed eight cellular level ratio models and from them we derived simplified models that share as a major determining factor the ratio of extracellular to intracellular water ratio (E/I). The E/I value varies widely among adults. Model analysis reveals that the magnitude and variability of each body component ratio can be predicted by correlating the cellular level model with the E/I value. Our approach thus provides new insights into and improved understanding of body composition ratios in adults.
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Schuurman HJ, Pierson RN. Progress towards clinical xenotransplantation. FRONT BIOSCI-LANDMRK 2008; 13:204-20. [PMID: 17981539 DOI: 10.2741/2671] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Xenotransplantation has progressed from early heroic experiments on the path to meet the ever increasing demands of tissue and organ transplantation in patients with end-stage organ failure. The pig species is regarded as the most promising donor species. However, due to the evolutionary distance, innovative approaches are to be developed to permit life-supporting function in humans. Transplantation of organs from non-human primates has increased our knowledge on rejection mechanisms and provided opportunities for testing modified immunosuppression of the host and genetic modification of the donor. The development of transgenic animals expressing human complement-regulatory factors, and of animals lacking the target for naturally occurring anti-pig antibodies, has essentially eradicated hyperacute rejection of solid organs. However, there is still a need for tolerable immunosuppression or immune-tolerance regimens to provide broadly available procedures in the clinical setting. Safety concerns especially cross-species transmission of infectious pathogens, in particular of porcine endogenous retrovirus. Many studies have indicated that this is highly unlikely. At present, cell and tissue transplantation of islets of Langerhans to diabetic patients is close to being tested in well-designed clinical trials. Further research is required before other porcine xenografts can offer a broadly available therapeutic option in clinical medicine.
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Levitt DG, Heymsfield SB, Pierson RN, Shapses SA, Kral JG. Physiological models of body composition and human obesity. Nutr Metab (Lond) 2007; 4:19. [PMID: 17883858 PMCID: PMC2082278 DOI: 10.1186/1743-7075-4-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 09/20/2007] [Indexed: 02/06/2023] Open
Abstract
Background The body mass index (BMI) is the standard parameter for predicting body fat fraction and for classifying degrees of obesity. Currently available regression equations between BMI and fat are based on 2 or 3 parameter empirical fits and have not been validated for highly obese subjects. We attempt to develop regression relations that are based on realistic models of body composition changes in obesity. These models, if valid, can then be extrapolated to the high fat fraction of the morbidly obese. Methods The analysis was applied to 3 compartment (density and total body water) measurements of body fat. The data was collected at the New York Obesity Research Center, Body Composition Unit, as part of ongoing studies. A total of 1356 subjects were included, with a BMI range of 17 to 50 for males and 17 to 65 for females. The body composition model assumes that obese subjects can be represented by the sum of a standard lean reference subject plus an extra weight that has a constant adipose, bone and muscle fraction. Results There is marked age and sex dependence in the relationship between BMI and fat fraction. There was no significant difference among Caucasians, Blacks and Hispanics while Asians had significantly greater fat fraction for the same BMI. A linear relationship between BMI and fat fraction provides a good description for men but overestimates the fat fraction in morbidly obese women for whom a non-linear regression should be used. New regression relations for predicting body fat just from experimental measurements of body density are described that are more accurate then those currently used. From the fits to the experimental BMI and density data, a quantitative description of the bone, adipose and muscle body composition of lean and obese subjects is derived. Conclusion Physiologically realistic models of body composition provide both accurate regression relations and new insights about changes in body composition in obesity.
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Bauman WA, Spungen AM, Wang J, Pierson RN. The relationship between energy expenditure and lean tissue in monozygotic twins discordant for spinal cord injury. ACTA ACUST UNITED AC 2007; 41:1-8. [PMID: 15273892 DOI: 10.1682/jrrd.2004.01.0001] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Energy expenditure and fat-free mass (FFM), as well as the relationships between these parameters, were investigated in thirteen pairs of monozygotic twins discordant for SCI. Basal energy expenditure (BEE) and resting energy expenditure (REE) were determined by indirect calorimetry. Measurements for FFM and fat mass were obtained by dual-energy x-ray absorptiometry. Total body potassium was determined by a 4-Pi whole-body counting chamber. Values are expressed as mean standard deviation. BEE and REE of the twins with SCI were significantly less than those of the able-bodied co-twins (1387 268 vs. 1660 324 kcal/d, p < 0.005, and 1682 388 vs. 1854 376 kcal/d, p < 0.05, respectively). Regardless of the group, direct and highly significant relationships were evident between BEE or REE and FFM or TBK. In summary, twins with SCI had lower energy expenditure than their able-bodied co-twins. Regardless of paralysis, direct linear relationships existed between energy expenditure and measures of lean mass.
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Cooper DKC, Dorling A, Pierson RN, Rees M, Seebach J, Yazer M, Ohdan H, Awwad M, Ayares D. Alpha1,3-galactosyltransferase gene-knockout pigs for xenotransplantation: where do we go from here? Transplantation 2007; 84:1-7. [PMID: 17627227 DOI: 10.1097/01.tp.0000260427.75804.f2] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The ability to genetically engineer pigs that no longer express the Galalpha1,3Gal (Gal) oligosaccharide has been a significant step toward the clinical applicability of xenotransplantation. Using a chronic immunosuppressive regimen based on costimulatory blockade, hearts from these pigs have survived from 2 to 6 months in baboons. Graft failure was predominantly from the development of a thrombotic microangiopathy. Potential contributing factors include the presence of preformed anti-nonGal antibodies or the development of low levels of elicited antibodies to nonGal antigens, natural killer (NK) cell or macrophage activity, and inherent coagulation dysregulation between pigs and primates. The breeding of pigs transgenic for an "anticoagulant" gene, such as human tissue factor pathway inhibitor, hirudin, or CD39, or lacking the gene for the prothrombinase, fibrinogen-like protein-2, is anticipated to inhibit the change in the endothelium to a procoagulant state that takes place in the pig organ after transplantation. The identification of the targets for anti-nonGal antibodies and/or human macrophages might allow further genetic modification of the pig, and xenogeneic NK cell recognition and activation may be inhibited by the transgenic expression of human leukocyte antigen molecules and/or by blocking the function of activating NK receptors. The ultimate goal of induction of T-cell tolerance may be possible only if these hurdles in the coagulation system and innate immunity can be overcome.
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Freedman DS, Wang J, Ogden CL, Thornton JC, Mei Z, Pierson RN, Dietz WH, Horlick M. The prediction of body fatness by BMI and skinfold thicknesses among children and adolescents. Ann Hum Biol 2007; 34:183-94. [PMID: 17558589 DOI: 10.1080/03014460601116860] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Although the body mass index (BMI, kg m(-2)) is widely used as a measure of adiposity, it is a measure of excess weight, rather than excess body fat. It has been suggested that skinfold thicknesses be measured among overweight children to confirm the presence of excess adiposity. OBJECTIVE The present study examined the additional information provided by skinfold thicknesses on body fatness, beyond that conveyed by BMI-for-age, among healthy 5- to 18-years old (n = 1196). METHODS AND PROCEDURES Total body dual-energy X-ray absorptiometry (DXA) provided estimates of % body fat, and the sum of two skinfolds (triceps and subscapular) was used as an indicator of the overall skinfold thickness. RESULTS As assessed by the multiple R(2)s and the residuals of various regression models, information on the skinfold sum significantly ( p < 0.001) improved the prediction of body fatness beyond that obtained with BMI-for-age. For example, the use of the skinfold sum, in addition to BMI-for-age, increased the multiple R(2)s for predicting % body fat from 0.81 to 0.90 (boys), and from 0.82 to 0.89 (girls). The use of the skinfold sum also reduced the overall prediction errors (absolute value of the residuals) for % body fat by 20-30%, but these reductions varied substantially by BMI-for-age. Among overweight children, defined by a BMI-for-age >/=95th percentile, the skinfold sum reduced the predication errors for % body fat by only 7-9%. CONCLUSIONS Although skinfold thicknesses, when used in addition to BMI-for-age, can substantially improve the estimation of body fatness, the improvement among overweight children is small.
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Schröder C, Pierson RN, Nguyen BNH, Kawka DW, Peterson LB, Wu G, Zhang T, Springer MS, Siciliano SJ, Iliff S, Ayala JM, Lu M, Mudgett JS, Lyons K, Mills SG, Miller GG, Singer II, Azimzadeh AM, DeMartino JA. CCR5 Blockade Modulates Inflammation and Alloimmunity in Primates. THE JOURNAL OF IMMUNOLOGY 2007; 179:2289-99. [PMID: 17675490 DOI: 10.4049/jimmunol.179.4.2289] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pharmacologic antagonism of CCR5, a chemokine receptor expressed on macrophages and activated T cells, is an effective antiviral therapy in patients with macrophage-tropic HIV infection, but its efficacy in modulating inflammation and immunity is only just beginning to be investigated. In this regard, the recruitment of CCR5-bearing cells into clinical allografts is a hallmark of acute rejection and may anticipate chronic rejection, whereas conventionally immunosuppressed renal transplant patients homozygous for a nonfunctional Delta32 CCR5 receptor rarely exhibit late graft loss. Therefore, we explored the effects of a potent, highly selective CCR5 antagonist, Merck's compound 167 (CMPD 167), in an established cynomolgus monkey cardiac allograft model. Although perioperative stress responses (fever, diminished activity) and the recruitment of CCR5-bearing leukocytes into the graft were markedly attenuated, anti-CCR5 monotherapy only marginally prolonged allograft survival. In contrast, relative to cyclosporine A monotherapy, CMPD 167 with cyclosporine A delayed alloantibody production, suppressed cardiac allograft vasculopathy, and tended to further prolong graft survival. CCR5 therefore represents an attractive therapeutic target for attenuating postsurgical stress responses and favorably modulating pathogenic alloimmunity in primates, including man.
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Rogers JG, Butler J, Lansman SL, Gass A, Portner PM, Pasque MK, Pierson RN. Chronic Mechanical Circulatory Support for Inotrope-Dependent Heart Failure Patients Who Are Not Transplant Candidates. J Am Coll Cardiol 2007; 50:741-7. [PMID: 17707178 DOI: 10.1016/j.jacc.2007.03.063] [Citation(s) in RCA: 275] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 03/22/2007] [Accepted: 03/28/2007] [Indexed: 11/17/2022]
Abstract
OBJECTIVES This study evaluated the impact of left ventricular assist device (LVAD) support on survival and quality of life in inotrope-dependent heart failure patients ineligible for cardiac transplantation. BACKGROUND The role for LVADs as a bridge to cardiac transplantation has been established, but data supporting their role as permanent therapy in nontransplant candidates are limited. METHODS The INTrEPID (Investigation of Nontransplant-Eligible Patients Who Are Inotrope Dependent) trial was a prospective, nonrandomized clinical trial comparing LVAD with optimal medical therapy (OMT). Fifty-five patients with New York Heart Association functional class IV symptoms who failed weaning from inotropic support were offered a Novacor LVAD. Eighteen of these patients did not receive an LVAD owing to patient preference (n = 14) or unavailability of the device (n = 4) but consented to follow-up and constitute a contemporaneous control group. RESULTS The LVAD and OMT patients were well matched for demographic and disease severity measures, except OMT patients had a lower mean serum sodium (128 mg/dl vs. 134 mg/dl; p = 0.001) and a higher mean blood urea nitrogen concentration (59 vs. 40; p = 0.02). The LVAD-treated patients had superior survival rates at 6 months (46% vs. 22%; p = 0.03) and 12 months (27% vs. 11%; p = 0.02). Adverse event rates were higher in the OMT group. Eighty-five percent of the LVAD-treated patients had minimal or no heart failure symptoms. Five LVAD patients and 1 OMT patient improved sufficiently while on therapy to qualify for cardiac transplantation. CONCLUSIONS Inotrope-dependent heart failure patients who are ineligible for transplantation have a high short-term mortality rate and derive a significant survival advantage from "destination" mechanical circulatory support.
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Sykes M, Pierson RN, O'Connell P, D'Apice A, Cowan P, Cozzi E, Dorling A, Hering B, Leventhal J, Soulillou JP. Reply to 'Critics slam Russian trial to test pig pancreas for diabetes'. Nat Med 2007; 13:662-3. [PMID: 17554327 DOI: 10.1038/nm0607-662] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Mayer LES, Roberto CA, Glasofer DR, Etu SF, Gallagher D, Wang J, Heymsfield SB, Pierson RN, Attia E, Devlin MJ, Walsh BT. Does percent body fat predict outcome in anorexia nervosa? Am J Psychiatry 2007; 164:970-2. [PMID: 17541059 PMCID: PMC2741391 DOI: 10.1176/ajp.2007.164.6.970] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The goal of this study was to investigate the relationship of body composition and neuroendocrine levels with clinical outcome in women with anorexia nervosa in a relapse-prevention trial. METHOD Body composition and fasting cortisol and leptin levels were assessed before random assignment in 32 weight-recovered subjects with anorexia nervosa from the New York site of the Fluoxetine to Prevent Relapse in Women With Anorexia Nervosa trial. Clinical outcome at the end of study participation was defined using modified Morgan-Russell criteria (full, good, fair, poor), then dichotomized into treatment "success" or "failure." RESULTS In a binary logistic regression model examining the effect of percent body fat, body mass index, anorexia nervosa subtype, waist-to-hip ratio, and serum cortisol and leptin levels on treatment outcome, only percent body fat was significantly associated with outcome. CONCLUSIONS In recently weight-restored women with anorexia nervosa, lower percent body fat was associated with poor long-term outcome.
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Mei Z, Grummer-Strawn LM, Wang J, Thornton JC, Freedman DS, Pierson RN, Dietz WH, Horlick M. Do skinfold measurements provide additional information to body mass index in the assessment of body fatness among children and adolescents? Pediatrics 2007; 119:e1306-13. [PMID: 17545361 DOI: 10.1542/peds.2006-2546] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES The purpose of this work was to validate the performance of age- and gender-specific BMI, triceps, and subscapular skinfold for the classification of excess of body fat in children and adolescents and to examine how much additional information these 2 skinfold measurements provide to BMI-for-age. METHODS The receiver operating characteristic curve was used to characterize the sensitivity and specificity of these 3 indices in classifying excess body fat. Percentage of body fat was determined by dual-energy radiograph absorptiometry. Both > or = 85th and > or = 95th percentile of percentage of body fat were used to define excess body fat. Data from the New York Pediatric Rosetta Body Composition Project were examined (n = 1196; aged 5-18 years). RESULTS For children aged 5 to 18 years, BMI-for-age, triceps skinfold-for-age, and subscapular skinfold-for-age each performed equally well alone in the receiver operating characteristic curves in the identification of excess body fat defined by either the 85th or 95th percentile of percentage of body fat by dual-energy radiograph absorptiometry. However, if BMI-for-age was already known and was > 95th percentile, the additional measurement of skinfolds did not significantly increase the sensitivity or specificity in the identification of excess body fat. CONCLUSIONS In contrast to the recommendations of expert panels, skinfold measurements do not seem to provide additional information about excess body fat beyond BMI-for-age alone if the BMI-for-age is >95th percentile.
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Wu CH, Heshka S, Wang J, Pierson RN, Heymsfield SB, Laferrère B, Wang Z, Albu JB, Pi-Sunyer X, Gallagher D. Truncal fat in relation to total body fat: influences of age, sex, ethnicity and fatness. Int J Obes (Lond) 2007; 31:1384-91. [PMID: 17452992 PMCID: PMC2752389 DOI: 10.1038/sj.ijo.0803624] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To investigate the influence of age, sex, ethnicity and total fatness on central obesity in four ethnic populations. DESIGN Cross-sectional analysis of study subjects enrolled from 1993 to 2005. SUBJECTS A multi-ethnic (Caucasian (CA), African-American (AA), Hispanic-American (HA) and Asian (As)) convenience sample of 604 men and 1192 women (aged 18-96 years, body mass index 15.93-45.80 kg/m(2)). MEASUREMENTS Total body fat (TBF) and truncal fat were measured by dual-energy X-ray absorptiometry. General linear regression models were used to test for independent associations with log(10)-transformed truncal fat. RESULTS For all ethnicities, men had a lower percent body fat and more truncal fat than women. Log(10-)transformed truncal fat increased with TBF approximately as a square root function. At older ages, there was a greater amount of truncal fat in CA, HA and As men (approximately 0.20-0.25 kg/decade) with the effect more pronounced in AA men ( approximately 0.33 kg/decade). For women, the increment of truncal fat per decade was reduced in CA and AA women (approximately 0.07 kg) compared with As and HA women (approximately 0.33 kg). Adjusted for mean values of covariates in our sample, AA had less truncal fat than As. CONCLUSION The accumulation of truncal fat is strongly related to age, ethnicity and total fatness in both men and women.
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Silva AM, Wang J, Pierson RN, Wang Z, Spivack J, Allison DB, Heymsfield SB, Sardinha LB, Heshka S. Extracellular water across the adult lifespan: reference values for adults. Physiol Meas 2007; 28:489-502. [PMID: 17470983 DOI: 10.1088/0967-3334/28/5/004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Extracellular water (ECW) is a large and clinically important body compartment that varies widely in volume both in health and disease. Interpretation of ECW measurements in the clinical setting requires consideration of potential influencing factors such as age, race, sex and other variables that influence fluid status. An important gap in physiological research is a lack of normative ECW values against which to reference perturbations in fluid homeostasis. The current study's aim was to develop conditional quantile equations for ECW based on weight, height, age, sex and race using a large (n = 1538, 854 females and 684 males) healthy adult multi-ethnic (African American, Asian, European American, Hispanic) sample. ECW was derived from total body water and potassium measured by isotope dilution and whole-body 40K counting, respectively. Quantile regression methods were used to identify five percentile levels (10th, 25th, 50th, 75th, 90th). Weight and height were significant variables at each quantile in both males and females; age made a significant contribution in the male but not the female sample. These regression equations provide ECW quantile reference values based on a large multi-ethnic adult population that should not only prove useful in clinical settings and physiological research, but serve as a model approach for developing body composition normative ranges.
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Nguyen BNH, Azimzadeh AM, Zhang T, Wu G, Schuurman HJ, Shuurman HJ, Sachs DH, Ayares D, Allan JS, Pierson RN. Life-supporting function of genetically modified swine lungs in baboons. J Thorac Cardiovasc Surg 2007; 133:1354-63. [PMID: 17467457 DOI: 10.1016/j.jtcvs.2006.11.043] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 11/10/2006] [Accepted: 11/20/2006] [Indexed: 11/22/2022]
Abstract
OBJECTIVE During ex vivo perfusion with human blood, homozygous galactosyl transferase knockout swine lungs exhibit prolonged survival (approximately 2 hours) relative to wild-type (<15 minutes) and swine lungs expressing human decay accelerating factor (<1 hour). In this study, the in vivo behavior of galactosyl transferase knockout lungs was evaluated. METHODS Three galactosyl transferase knockout swine left lungs were transplanted into baboons in a life-supporting model. One baboon lung allograft and two swine lung xenografts transgenic for human membrane cofactor protein (CD46) served as controls. RESULTS Whereas two membrane cofactor protein lungs exhibited high pulmonary vascular resistance (>500 mm Hg x min/L) and failed to support life within 21 minutes, two of three galactosyl transferase knockout lungs supported life, for 90 and 215 minutes, and displayed low peripheral vascular resistance (48 +/- 12 mm Hg x min/L at 60 minutes), similar to the allogeneic control. Complement activation (delta C3a < 250 ng/mL through 60 minutes) and C5b-9 deposition were minimal in both galactosyl transferase knockout and membrane cofactor protein lungs. Neutrophils, monocytes, and platelets were rapidly sequestered in galactosyl transferase knockout and human membrane cofactor protein lung recipients, unlike the allogeneic control (<20%); and thrombin formation (delta plasma fraction 1+2 > 0.5 nmol/L) was seen in the galactosyl transferase knockout recipients. Platelet activation (beta-thromboglobulin rise > 200) and appearance of capillary congestion and vessel thrombosis confirmed coagulation activation associated with galactosyl transferase knockout lung failure. CONCLUSIONS Galactosyl transferase knockout swine lungs are significantly protected in vivo from the physiologic consequences (increased pulmonary vascular resistance, capillary leak) associated with hyperacute lung rejection. As during ex vivo perfusion, dysregulated coagulation-thrombin elaboration, platelet activation, and intravascular thrombosis-mediates galactosyl transferase knockout lung xenograft injury.
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Chambers EC, Heshka S, Gallagher D, Wang J, Pi-Sunyer FX, Pierson RN. Serum magnesium and type-2 diabetes in African Americans and Hispanics: a New York cohort. J Am Coll Nutr 2007; 25:509-13. [PMID: 17229898 DOI: 10.1080/07315724.2006.10719566] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES The aim of this study was to examine the relationship of serum Mg with stage of diabetes measured by fasting serum glucose in a cohort of 485 African American and Hispanic adults. METHODS The cross sectional Rosetta study was designed to assess body composition in a multi-racial cohort of healthy adults living in New York City. The data utilized for the current analyses were collected during the years 1990 to 2000. Serum Mg and glucose were measured after a 10-12 hour fast. Dual-energy x-ray absorptiometry was used to measure fat mass (FM) and fat free mass (FFM). RESULTS The mean age of the cohort was 53 +/- 16 years. Hispanics had significantly lower (p < 0.05) mean serum Mg levels (0.82 +/- 0.07 mmol/L vs. 0.85 +/- 0.07 mmol/L) and FFM (48.8 +/- 10.9 kg vs. 50.9 +/- 10.3 kg) compared to African Americans. In both race/ethnic groups, individuals classified as having diabetes had significantly (p < 0.001) lower serum concentrations of Mg (0.80 +/- 0.07 mmol/L) compared to the normal group (0.84 +/- 0.07 mmol/L). CONCLUSIONS These results show that in African American and Hispanic adults, those with diabetes have lower serum Mg levels compared to those classified as pre-diabetic or those with normal fasting glucose levels.
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Collins MJ, Ozeki T, Zhuo J, Gu J, Gullapalli R, Pierson RN, Griffith BP, Fedak PWM, Poston RS. Use of diffusion tensor imaging to predict myocardial viability after warm global ischemia: possible avenue for use of non-beating donor hearts. J Heart Lung Transplant 2007; 26:376-83. [PMID: 17403480 DOI: 10.1016/j.healun.2006.12.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 11/10/2006] [Accepted: 12/12/2006] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND The assessment of myocardial viability after global warm ischemia (WI) but before reperfusion is challenging. We hypothesized that fractional anisotropy (FA), a magnetic resonance imaging (MRI) parameter of water diffusion that characterizes cellular integrity within tissues, provides a rapid and useful method for evaluating the viability of hearts after WI. METHODS Dog hearts were exposed to 60 minutes of WI after exanguination, explanted and preserved in a cold, non-beating state for 6 hours, using continuous perfusion (CP) or static cold storage (CS). Toward the end of preservation, a global FA assessment, acquired using MRI, was compared with analyses obtained from myocardial biopsies that included adenosine triphosphate (ATP), endothelin-1 (ET-1) and caspase-3 levels, light microscopy and tetrazolium staining. Functional recovery was analyzed after restoration of blood flow on a non-working Langendorff preparation. RESULTS FA measured at the end of CP showed strong correlations with all parameters of functional recovery (developed pressure, R = 0.60; dP/dt, R = 0.96; -dP/dt, R = 0.96). Although FA also correlated with tissue levels of ATP, ET-1 and caspase-3 (R = 0.77, -0.84, -0.64), recovery of myocardial function did not correlate with these markers or any other conventional analyses of myocardial injury (troponin I, changes on light microscopy or tetrazolium staining). CONCLUSIONS FA, an MRI-based parameter that indicates cellular integrity, was found to reflect better myocardial ATP stores, less induction of ET-1 and caspase-3 and improved functional recovery of hearts after global WI. As a clinically applicable tool capable of rapidly differentiating reversible from lethal injury, diffusion tensor imaging may prove useful in the eventual adoption of non-beating donor hearts for transplantation.
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Feller ED, Sorensen EN, Haddad M, Pierson RN, Johnson FL, Brown JM, Griffith BP. Clinical Outcomes Are Similar in Pulsatile and Nonpulsatile Left Ventricular Assist Device Recipients. Ann Thorac Surg 2007; 83:1082-8. [PMID: 17307463 DOI: 10.1016/j.athoracsur.2006.10.034] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 10/11/2006] [Accepted: 10/16/2006] [Indexed: 11/22/2022]
Abstract
BACKGROUND Despite concerns about the adequacy of support provided by continuous-flow left ventricular assist devices (LVADs), direct comparisons of patient characteristics and outcomes between first-generation pulsatile and second-generation nonpulsatile LVADs are absent. We hypothesized that a nonpulsatile Jarvik 2000 LVAD (Jarvik Heart, Inc, New York, NY) would result in comparable outcomes to those of similarly ill patients implanted with a pulsatile LVAD (Novacor, WorldHeart Inc, Oakland, CA; and HeartMate XVE, Thoratec, Pleasanton, CA). METHODS We retrospectively compared common pre-LVAD clinical characteristics and indicators of heart failure severity between 13 pulsatile and 14 nonpulsatile LVAD recipients. The outcomes analyzed were either heart transplantation, if the LVAD was intended as a bridge to transplantation, or hospital discharge if the intention was destination therapy. RESULTS There was no significant difference between groups in pre-LVAD disease severity indicators. Nonpulsatile LVAD recipients had a significantly smaller body surface area (1.9 +/- 0.2 m2 versus 2.1 +/- 0.2 m2, p = 0.04) and cardiopulmonary bypass time was also significantly shorter (61 +/- 34 minutes versus 110 +/- 49 minutes, p = 0.01). Aside from duration of initial intensive care unit stay (nonpulsatile, 10 +/- 16 days; pulsatile, 14 +/- 11 days; p = 0.02), there was no difference in post-LVAD outcomes: 10 of 14 nonpulsatile and 8 of 13 pulsatile LVAD patients achieved the combined end point (p = 0.69). CONCLUSIONS Similarly ill congestive heart failure patients benefited equally well from either a nonpulsatile or a pulsatile LVAD. This may support an expanded role for nonpulsatile LVADs in the treatment of severe heart failure.
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Sykes M, Cozzi E, D'Apice AJF, Pierson RN, O'Connell P, Cowan P, Dorling A, Hering B, Soulillou JP, Sandrin M. Response to Valdes-Gonzalez ''Clinical trial of islet xenotransplantation in Mexico''. Xenotransplantation 2007; 14:90-1. [PMID: 17214710 DOI: 10.1111/j.1399-3089.2006.00373.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
The father of cardiac transplantation, Norman Shumway, famously predicted that tolerance was the future of the field, and always would be. Although his prediction remains true to date, significant progress has been made toward this goal, the "Holy Grail" for transplant clinicians. Current efforts are fueled by disappointing long-term outcomes associated with chronic immunosuppression, and the promise that partial or complete tolerance will impact long-term results favorably. This article provides a clinical definition of tolerance primarily based on lessons learned from animal heart allograft models. It reviews several promising strategies for inducing tolerance and detecting its presence through the use of biomarkers in peripheral blood or the graft, and outlines a possible path toward making this vision a clinical reality.
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Wu G, Pfeiffer S, Schröder C, Zhang T, Nguyen BN, Kelishadi S, Atkinson JB, Schuurman HJ, White DJG, Azimzadeh AM, Pierson RN. Coagulation cascade activation triggers early failure of pig hearts expressing human complement regulatory genes. Xenotransplantation 2007; 14:34-47. [PMID: 17214703 DOI: 10.1111/j.1399-3089.2006.00362.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Hyperacute rejection (HAR) and early graft failure (EGF) have been described in a minority of pig-to-baboon heart transplants using organs transgenic for human complement regulatory proteins (hCRP). Here we investigate the role of coagulation cascade activation in the pathogenesis of HAR and EGF in a consecutive series where a high incidence of these outcomes was observed. METHODS Twenty-eight naïve wild-caught Papio anubis baboons received heterotopic heart transplants from pigs transgenic for hDAF (n = 23) or hMCP (n = 5). Immunosuppression consisted of cyclosporine A, cyclophosphamide and MMF (n = 18) or anti-CD154 mAb (IDEC-131) and ATG (n = 10). Eleven received anti-Gal carbohydrates (GAS914, n = 8, or NEX1285, n = 3), of which four also underwent extracorporeal immunoadsorption (EIA), and 12 also received pharmacologic complement inhibitors (C1 INH, n = 9, or APT070, n = 3). RESULTS Excluding one technical failure, 14 of 27 transplants (11 hDAF, 3 hMCP) exhibited either HAR (n = 10) or EGF (n = 4). Surprisingly, neither complement inhibition (with C1 INH or APT070) nor anti-Gal antibody depletion with GAS914, NEX1285, or additional EIA consistently prevented HAR or EGF despite low or undetectable complement deposition. Strikingly, most grafts with HAR/EGF exhibited prominent fibrinogen and platelet deposition associated with systemic coagulation cascade activation, consistent with non-physiologic intravascular coagulation, in many instances despite little evidence for antibody-mediated complement activation. CONCLUSION We conclude that dysregulated coagulation correlates closely with and probably causes primary failure of pig hearts transgenic for hCRP. These data support efforts to define effective strategies to prevent dysregulated coagulation in pig organ xenografts.
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