45 results on '"J. Korner"'
Search Results
2. Demand and experiences with financial products and services in climate smart villages
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P. Phuong Thanh, L. Sebastiaan, Maren A.O. Radeny, Robert B. Zougmoré, N. Dinh Tien, adaptive land, Annemarie Groot, D. Kitondo, John W.M. Recha, Mangi L. Jat, A. Pant, V. Santacruz, W.W.P. Jans, B. Nyour, Wimek, D. Martinez Baron, P. Aggrarwal, M.A.P.M. van Asseldonk, Philip Kimeli, M. Diop, O. Muhimbo, T. Long, H. Ibrahim, J. Korner, J.S. Bolt, P. Maalong-Gae, Wass, E. Osmond, Arun Khatri-Chhetri, Mathieu Ouédraogo, O. van Steenis, Nitya Chanana, C.J. Wattel, and T. Bawa
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International research ,WIMEK ,Latin Americans ,business.industry ,Business Management & Organisation ,Climate change ,WASS ,Business model ,Innovation- and Risk Management and Information Governance ,Climate Resilience ,Incentive ,Klimaatbestendigheid ,Agriculture ,Life Science ,Business ,Marketing ,Value chain ,Financial services - Abstract
This study ‘Demand for and experiences with financial products and services’ describes and discusses the results of a survey to provide a first insight into the financial services that the smallholder farmers from climate smart villages use and to explore how these are related to climate smart agricultural technologies & practices. The study is one of three preliminary studies of a multi-year international research project (2016-2022) on ‘Business models, incentives and innovative finance for scaling climate smart agriculture (CSA)’. The knowledge and insights developed are used to further support ongoing and emerging climate smart projects in which CCAFS is involved. A survey was conducted to identify smallholder farmers and the small to medium enterprises (in different stages of the value chain) and their demand for and experiences with financial products and services. There were 148 respondents from 24 villages from Latin America, West Africa, East Africa, Southeast Asia and South Asia. The targeted number of female respondents (50%) was nog met in all regions, for example in India where the role of female farmers in irrigated agriculture would be limited. A limitation to the results is that in different regions a different number of villages was involved, making it more difficult to generalise results. Sometimes it would prove challenging to make conclusions about the reasoning behind the answers. The study is about adoption climate smart agriculture, but does not define the extent of adoption. ..
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- 2018
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3. Metabolic vs. hedonic obesity: a conceptual distinction and its clinical implications
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Ralph Peterli, Y‐H. Yu, J. I. Mechanick, J. Korner, J. R. Vasselli, and YW Zhang
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medicine.medical_specialty ,Food intake ,Endocrinology, Diabetes and Metabolism ,Hypothalamus ,Energy balance ,030209 endocrinology & metabolism ,Overweight ,Biology ,Eating ,03 medical and health sciences ,Reward system ,0302 clinical medicine ,Reward ,Internal medicine ,energy expenditure ,Neural Pathways ,medicine ,Homeostasis ,Humans ,Effective treatment ,Obesity ,030304 developmental biology ,2. Zero hunger ,0303 health sciences ,Appetite Regulation ,Body Weight ,Public Health, Environmental and Occupational Health ,medicine.disease ,food reward ,Obesity Etiology ,Endocrinology ,Energy expenditure ,Metabolic regulation ,Body weight regulation ,medicine.symptom ,Energy Metabolism - Abstract
Summary Body weight is determined via both metabolic and hedonic mechanisms. Metabolic regulation of body weight centres around the ‘body weight set point’, which is programmed by energy balance circuitry in the hypothalamus and other specific brain regions. The metabolic body weight set point has a genetic basis, but exposure to an obesogenic environment may elicit allostatic responses and upward drift of the set point, leading to a higher maintained body weight. However, an elevated steady‐state body weight may also be achieved without an alteration of the metabolic set point, via sustained hedonic over‐eating, which is governed by the reward system of the brain and can override homeostatic metabolic signals. While hedonic signals are potent influences in determining food intake, metabolic regulation involves the active control of both food intake and energy expenditure. When overweight is due to elevation of the metabolic set point (‘metabolic obesity’), energy expenditure theoretically falls onto the standard energy–mass regression line. In contrast, when a steady‐state weight is above the metabolic set point due to hedonic over‐eating (‘hedonic obesity’), a persistent compensatory increase in energy expenditure per unit metabolic mass may be demonstrable. Recognition of the two types of obesity may lead to more effective treatment and prevention of obesity.
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- 2015
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4. Translating Patient Safety Research Into Clinical Practice
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Marsha A. Raebel, Eli J. Korner, Russell E. Glasgow, Richard Platt, David W. Bates, Ted E. Palen, Paul A. Estabrooks, David J. Magid, John F. Steiner, and David W. Brand
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education.field_of_study ,medicine.medical_specialty ,business.industry ,010102 general mathematics ,Population ,Pharmacist ,Pharmacy ,01 natural sciences ,Clinical trial ,03 medical and health sciences ,Patient safety ,0302 clinical medicine ,Patient satisfaction ,Family medicine ,Medicine ,Generalizability theory ,030212 general & internal medicine ,Internal validity ,0101 mathematics ,education ,business - Abstract
There is a pressing need to make patient safety research more relevant to clinicians and decisionmakers. The RE-AIM framework of Reach, Effectiveness, Adoption, Implementation and Maintenance is one approach investigators can use to assess a study’s potential for translation from research to clinical practice. In this paper, we show how the RE-AIM approach is being used to evaluate a pharmacy alert intervention designed to detect and correct medication prescribing errors for all patients prescribed medications in a large health maintenance organization (HMO). In the REAIM framework, Reach is assessed by calculating the participation rate and evaluating the degree to which the patients enrolled in the study are representative of the larger patient population (i.e., the “representativeness” of the sample). Effectiveness is assessed across multiple dimensions. Medication errors are the primary outcome. Other outcomes include prescriber, pharmacist and patient satisfaction; measures of unintended consequences (e.g., false-positive alerts), and potential negative impacts (e.g., repeat patient visits to the pharmacy). Adoption is measured by calculating the participation rates of the pharmacies and pharmacists approached to participate in the project. Representativeness is assessed by comparing the characteristics of pharmacies and pharmacists that participate to those that do not. Implementation is assessed as the degree to which intervention components are delivered as intended. Measures of technical performance include the validity of alerts and system reliability. Measures of pharmacist performance include completeness of progress documentation and adherence to alert recommendations. Maintenance is assessed as the sustainability of the intervention’s impact during the study (at three, six, nine and 12 months), and at one year after its completion. Investigators interested in promoting the translation of their research and conducting “practical clinical trials” should consider external and internal validity issues. This paper describes one approach to the collection and reporting on measures of generalizability that are of interest to clinicians and decisionmakers.
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- 2007
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5. Disparities and Survival Among Breast Cancer Patients
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Liyan Liu, Hassan Fouayzi, Terry S. Field, Jennifer L. Ellis, Chyke A. Doubeni, Gene Hart, Richard Krajenta, Lisa J. Herrinton, Shelley M. Enger, Eli J. Korner, Donald J. Bachman, Diana Sm Buist, Mark C. Hornbrook, Lois Lamerato, and Janice Yao
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Adult ,Cancer Research ,medicine.medical_specialty ,Population ,Black People ,Breast Neoplasms ,Health Services Accessibility ,White People ,Cohort Studies ,Breast cancer ,medicine ,Humans ,Neoplasm Invasiveness ,Registries ,education ,Survival rate ,Survival analysis ,Aged ,Retrospective Studies ,Aged, 80 and over ,Gynecology ,education.field_of_study ,business.industry ,Mortality rate ,Hazard ratio ,Retrospective cohort study ,General Medicine ,Middle Aged ,Prognosis ,medicine.disease ,United States ,Survival Rate ,Receptors, Estrogen ,Oncology ,Female ,Receptors, Progesterone ,business ,SEER Program ,Demography ,Cohort study - Abstract
BACKGROUND: Although rates of survival for women with breast cancer have improved, the survival disparity between African American and white women in the United States has increased. PURPOSE: To determine whether this survival disparity persists in an insured population with access to medical care. METHODS: In this retrospective cohort study, we extracted data from the tumor registries of six nonprofit, integrated health care delivery systems affiliated with the Cancer Research Network and assessed the survival of African American (n = 2276) and white (n = 18 879) female enrollees who were diagnosed with invasive breast cancer from January 1, 1993, through December 31, 1998. Cox proportional hazards regression was used to estimate the death rate among African American women relative to that of white women after adjustment for potential explanatory factors including stage at diagnosis, tumor characteristics, and treatment. RESULTS: Five-year survival was lower for African American women (73.8%) than for white women (81.6%). African American women were less likely to have tumor characteristics with good prognosis. Controlling for age at diagnosis, stage, grade, tumor size, and estrogen and progesterone receptor status, the adjusted hazard rate ratio for African American women was 1.34 (95% confidence interval = 1.22 to 1.46). Similar risks were found among women ages 20-49 and 50 and older. Controlling for treatment slightly lowered the hazard rate ratio to 1.31 (95% confidence interval = 1.20 to 1.43). CONCLUSIONS: Among women with invasive breast cancer, being insured and having access to medical care does not eliminate the survival disparity for African American women.
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- 2005
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6. The influence of bone allograft processing on osteoblast attachment and function
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P. M. Rommens, Raphael Küchle, L. Konrad, J. Korner, Alexander Hofmann, M. H. Hessmann, and Jan D. Rompe
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Stromal cell ,Cell Survival ,medicine.medical_treatment ,Osteocalcin ,Population ,Gene Expression ,Bone Marrow Cells ,In Vitro Techniques ,Bone grafting ,Andrology ,Cell Adhesion ,medicine ,Humans ,Transplantation, Homologous ,Orthopedics and Sports Medicine ,Viability assay ,Cell adhesion ,education ,Cells, Cultured ,Bone Marrow Transplantation ,education.field_of_study ,Osteoblasts ,biology ,Chemistry ,Sterilization ,Cell Differentiation ,Osteoblast ,Alkaline Phosphatase ,Transplantation ,medicine.anatomical_structure ,Immunology ,biology.protein ,Stromal Cells ,Cell Division - Abstract
In order to assess the influence of eight different sterilisation and disinfection methods for bone allografts on adhesion, proliferation, and differentiation of human bone marrow stromal cells (BMSC), cells were grown in culture and then plated onto pieces of human bone allografts. Following processing methods were tested: autoclavation (AUT), low-temperature-plasma sterilisation of demineralised allografts (D-LTP), ethylene oxide sterilisation (EtO), fresh frozen bone (FFB), 80 degrees C-thermodisinfection (80 degrees C), gamma-irradiation (Gamma), chemical solvent disinfection (CSD), and Barrycidal-disinfection (BAR). The seeding efficiency was determined after one hour to detect the number of attached cells before mitosis started. The cell viability was determined after 3, 7, and 21 days. Tests to confirm the osteoblastic differentiation included histochemical alkaline phosphatase staining and RT-PCR for osteocalcin. Human BMSC showed greatest attachment affinities for D-LTP-, 80 degrees C-, and CSD-allografts, whereas less cells were found attached to AUT-, EtO-, FFB-, Gamma-, and BAR-probes. Cell viability assays at day 3 revealed highest proliferation rates within the FFB- and 80 degrees C-groups, whereas after 21 days most viable cells were found in D-LTP-, 80 degrees C-, CSD-, and Gamma-groups. BAR-treatment showed a considerably toxic effect and therefore was excluded from all further experiments. Highest AP-activity and gene expression of osteocalcin were detected in the D-LTP-group in comparison with all other groups. In summary, our results demonstrate that cell adhesion, final population, and function of BMSC are influenced by different disinfection and sterilisation methods. Therefore, processing-related alterations of BMSC-function may be important for the success of bone grafting. The experimental setup used in the present work may be useful for further optimisation of bone allograft processing.
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- 2005
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7. 'AND I SAW . . .' AN APOCALYPTIC LITERARY CONVENTION FOR STRUCTURAL IDENTIFICATION IN THE APOCALYPSE
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Ralph J. Korner
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History ,Biblical studies ,Literature and Literary Theory ,media_common.quotation_subject ,Religious studies ,Art history ,Art ,Language and Linguistics ,Convention ,New Testament ,Identification (psychology) ,Classics ,Humanities ,Jewish literature ,media_common - Abstract
L'A. etudie les implications structurelles de trois conventions litteraires : le referent espace/temps, la formule meta tauta eidon et ses variantes, la formule kai eidon. Il utilise l'expression episode visionnaire comme classification litteraire d'un texte visionnaire identifie a travers un referent espace/temps. La formule meta tauta eidon est utilisee pour identifier des visions majeures, la formule kai eidon pour des visions mineures. Les apocalypses de IV Esdras et II Baruch temoigne d'un usage de ces trois conventions plus raffine que I Henoch et Daniel. Les trois conventions litteraires dans l'Apocalypse de Jean donne une structure pour les textes de visions.
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- 2000
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8. Sex differences in visceral adipose tissue post-bariatric surgery compared to matched non-surgical controls
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J, Korner, M, Punyanitya, C, Taveras, D J, McMahon, H J, Kim, W, Inabnet, M, Bessler, and D, Gallagher
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Article - Abstract
OBJECTIVE AND METHODS: Given the profound weight loss after gastric banding and bypass we compared fat compartmentalization by whole body magnetic resonance imaging in women and men after these procedures to two groups of non-surgical controls who were either matched for age, weight and height or were of lower body mass index (BMI). RESULT: In women post-surgery (n=17; BMI 31.7 kg/m(2)) there was lower visceral adipose tissue (VAT) (1.4 vs 2.5 kg; P0.01) compared with matched controls (n=59; BMI 32.1 kg/m(2)). In contrast, VAT (5.3 vs 5.4 kg) was nearly identical in men post-surgery (n=10; BMI 34.1 kg/m(2)) compared with matched controls (n=10; BMI 32.1 kg/m(2)) even though the degree of weight reduction was not significantly different from women (27.4 vs 32.6%). Furthermore, VAT when adjusted for total adipose tissue (TAT) was 43% less in women post-surgery (1.2 vs 2.1 kg; P=0.03) than in controls with lower BMI (25.1 kg/m(2)). After adjustment for TAT, subcutaneous adipose tissue in women post-surgery was significantly greater than matched controls (35.1 vs 34.2 kg; P=0.03). There was a significant negative correlation of VAT and the degree of weight loss in women (r=-0.57; P=0.018) but this relationship was not significant in men (r=-0.39; P=0.27). Skeletal muscle was lower in both sexes compared with matched controls (women, 21.8 vs 23.1 kg; men, 32.5 vs 35.5 kg). CONCLUSION: Prospective studies are necessary to confirm if there is a sexual dimorphism in the effects of bariatric surgery on body composition.
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- 2010
9. Racial differences in tumor stage and survival for colorectal cancer in an insured population
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Carol Bigelow, Virginia P. Quinn, Terry S. Field, Eli J. Korner, Diana S. M. Buist, Edward H. Wagner, Chyke A. Doubeni, Jerry H. Gurwitz, Mark C. Hornbrook, Gene Hart, Lois Lamerato, and Lisa J. Herrinton
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Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Colorectal cancer ,Population ,Black People ,Lower risk ,White People ,Asian People ,medicine ,Ethnicity ,Humans ,education ,Survival rate ,Aged ,Neoplasm Staging ,Aged, 80 and over ,education.field_of_study ,Insurance, Health ,Proportional hazards model ,business.industry ,Mortality rate ,Hazard ratio ,Hispanic or Latino ,Middle Aged ,medicine.disease ,Prognosis ,Surgery ,Survival Rate ,Oncology ,Pacific islanders ,Female ,business ,Colorectal Neoplasms ,Demography - Abstract
BACKGROUND. Despite declining death rates from colorectal cancer (CRC), racial disparities have continued to increase. In this study, the authors examined disparities in a racially diverse group of insured patients. METHODS. This study was conducted among patients who were diagnosed with CRC from 1993 to 1998, when they were enrolled in integrated healthcare systems. Patients were identified from tumor registries and were linked to information in administrative databases. The sample was restricted to non-Hispanic whites (n = 10,585), non-Hispanic blacks (n = 1479), Hispanics (n = 985), and Asians/Pacific Islanders (n = 909). Differences in tumor stage and survival were analyzed by using polytomous and Cox regression models, respectively. RESULTS. In multivariable regression analyses, blacks were more likely than whites to have distant or unstaged tumors. In Cox models that were adjusted for nonmutable factors, blacks had a higher risk of death from CRC (hazard ratio [HR], 1.17; 95% confidence interval [95% CI], 1.06–1.30). Hispanics had a risk of death similar to whites (HR, 1.04; 95% CI, 0.92–1.18), whereas Asians/Pacific Islanders had a lower risk of death from CRC (HR, 0.89; 95% CI, 0.78–1.02). Adjustment for tumor stage decreased the HR to 1.11 for blacks, and the addition of receipt of surgical therapy to the model decreased the HR further to 1.06. The HR among Hispanics and Asians/Pacific Islanders was stable to adjustment for tumor stage and surgical therapy. CONCLUSIONS. The relation between race and survival from CRC was complex and appeared to be related to differences in tumor stage and therapy received, even in insured populations. Targeted interventions to improve the use of effective screening and treatment among vulnerable populations may be needed to eliminate disparities in CRC. Cancer 2007;109:612–620. © 2006 American Cancer Society.
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- 2006
10. Mennen clamp-on plate fixation of periprosthetic fractures of the humerus after shoulder arthroplasty--a report on 3 patients
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Pierre Hepp, Christoph Josten, J. Korner, Tim Rose, and H. Lill
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musculoskeletal diseases ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Joint Prosthesis ,Periprosthetic ,Prosthesis ,Fixation (surgical) ,Fracture Fixation, Internal ,medicine ,Humans ,Humerus ,Orthopedics and Sports Medicine ,Arthroplasty, Replacement ,Plate fixation ,Aged ,Aged, 80 and over ,Fracture Healing ,business.industry ,Shoulder Joint ,General Medicine ,Arthroplasty ,Surgery ,Radiography ,medicine.anatomical_structure ,Clamp ,Orthopedic surgery ,Shoulder Fractures ,Accidental Falls ,Female ,business ,Bone Plates - Abstract
(2004). Mennen clamp-on plate fixation of periprosthetic fractures of the humerus after shoulder arthroplasty—a report on 3 patients. Acta Orthopaedica Scandinavica: Vol. 75, No. 6, pp. 772-774.
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- 2005
11. Effects of leptin receptor mutation on Agrp gene expression in fed and fasted lean and obese (LA/N-faf) rats
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J, Korner, S L, Wardlaw, S M, Liu, I M, Conwell, R L, Leibel, and S C, Chua
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Male ,DNA, Complementary ,Pro-Opiomelanocortin ,Molecular Sequence Data ,Gene Expression ,Hypothalamus, Middle ,Proteins ,Receptors, Cell Surface ,Fasting ,Rats ,Rats, Sprague-Dawley ,Eating ,Reference Values ,Mutation ,Animals ,Intercellular Signaling Peptides and Proteins ,Receptors, Leptin ,Agouti-Related Protein ,Amino Acid Sequence ,Obesity ,RNA, Messenger ,Cloning, Molecular ,Carrier Proteins - Abstract
Agouti-related protein provides an orexigenic signal, probably through interaction with central melanocortin receptors. Expression of Agrp is markedly increased in the hypothalamus of mice deficient in leptin (Lep(ob)/Lep(ob)) or its receptor (Lepr(db)/Lepr(db)), suggesting that leptin mediates signals suppressing Agouti-related protein production. The regulation of Agrp expression in the rat hypothalamus has not been reported. We, therefore, analyzed the expression of Agrp in the medial basal hypothalamus of lean (+/+, +/fa(f)) and obese leptin receptor-deficient (fa(f)/fa(f)) LA/N rats. Using a sensitive solution hybridization/S1 nuclease protection assay, we found no significant difference in Agrp messenger RNA (mRNA) levels (pg/microg total RNA +/- SEM) in obese rats (n = 5), compared with lean controls (n = 5): 0.46 +/- 0.06 vs. 0.47 +/- 0.06 (P = 0.9). Similarly, no difference in Agrp expression was found using in situ hybridization or semiquantitative RT-PCR. In contrast to Agrp, Pomc mRNA levels were significantly suppressed in the obese, compared with the lean, rats (P = 0.001). Thus, the ratio of Pomc to Agrp mRNA is decreased in the obese rats and may be an important modulator of food intake. To assess the physiological regulation of Agrp in rats, we examined the effect of food deprivation in lean Sprague Dawley (SD) rats. There was a 273% increase in medial basal hypothalamus Agrp mRNA in SD rats fasted for 48 h (n = 8), compared with rats fed ad libitum (n = 8): 0.82 +/- 0.23 vs. 0.30 +/- 0.08 (P = 0.0001). Lean LA/N rats (n = 7) fasted for 48 h also showed a 231% increase in Agrp expression, compared with fed lean controls (n = 8): 0.74 +/- 0.11 vs. 0.32 +/- 0.03 (P = 0.002), whereas Pomc expression was decreased by 32% in fasted animals from the same experiment (0.34 +/- 0.05 vs. 0.50 +/- 0.07; P = 0.03). There were no significant differences in Agrp or Pomc mRNA levels between fasted and fed obese LA/N-fa(f) rats. These results suggest that, in the rat, the Agrp response to fasting may involve leptin-mediated phenomena, but factors in addition to leptin must also be involved in the regulation of Agrp gene expression.
- Published
- 2000
12. Employing electro-mechanical analogies for co-resonantly coupled cantilever sensors
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J. Körner, C. F. Reiche, B. Büchner, T. Mühl, and G. Gerlach
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Technology - Abstract
Understanding the behaviour of mechanical systems can be facilitated and improved by employing electro-mechanical analogies. These analogies enable the use of network analysis tools as well as purely analytical treatment of the mechanical system translated into an electric circuit. Recently, we developed a novel kind of sensor set-up based on two coupled cantilever beams with matched resonance frequencies (co-resonant coupling) and possible applications in magnetic force microscopy and cantilever magnetometry. In order to analyse the sensor's behaviour in detail, we describe it as an electric circuit model. Starting from a simplified coupled harmonic oscillator model with neglected damping, we gradually increase the complexity of the system by adding damping and interaction elements. For each stage, various features of the coupled system are discussed and compared to measured data obtained with a co-resonant sensor. Furthermore, we show that the circuit model can be used to derive sensor parameters which are essential for the evaluation of measured data. Finally, the much more complex circuit representation of a bending beam is discussed, revealing that the simplified circuit model of a coupled harmonic oscillator is a very good representation of the sensor system.
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- 2016
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13. The Superconducting Separated Orbit Cyclotron Tritron
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U. Trinks, G. Hinderer, R. Savoy, C. Riess, W. Assmann, B. Rehm, A. Platzer, M. Wandinger, K. Rieger, H. J. Korner, L. Dietl, and W. Wiedemann
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Superconductivity ,Physics ,Nuclear and High Energy Physics ,Cyclotron ,Particle accelerator ,Superconducting magnet ,Acceleration voltage ,Charged particle ,law.invention ,Nuclear physics ,Nuclear Energy and Engineering ,law ,Magnet ,Harmonic ,Electrical and Electronic Engineering - Abstract
At the Munich 13 MV-Tandem Laboratory the TRITRON is under development, which will be the prototype of a superconducting separated orbit cyclotron for acceleration of heavy ions with 0.04 < i 0.14 and 0.1 0.3. It consists of 12 flat, superconducting sector magnets with 20 neighbouring channels for the spiral-orbit (rin = 70 cm, re, = 150 cm). Due to the individual magnetic channels the transversal and longitudinal focusing properties are as in synchrotrons. The constant turn separation of Ar = 4 cm requires a maximum accelerating voltage of 3 MV per turn, which will be provided by 6 superconducting cavities positioned in each second field free sector gap (see contribution of L. Dietl). Due to the longitudinal focusing the RFfrequency (-170 MHz) may be a high harmonic (h 2 20) of the revolution frequency. Thus the frequency range for acceleration of ions with different revolution frequency can be kept small (+3 %). The magnets as well as the cavities are contained in the same cavity.
- Published
- 1985
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14. Feedback does not affect the reliability function of a DMC at rates above capacity (Corresp.)
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J. Korner and I. Csiszar
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Block code ,Reliability (computer networking) ,Function (mathematics) ,Library and Information Sciences ,Upper and lower bounds ,Computer Science Applications ,Control theory ,Coincident ,Exponent ,Applied mathematics ,Decoding methods ,Computer Science::Information Theory ,Information Systems ,Mathematics - Abstract
Asymptotically coincident upper and lower bounds on the exponent of the largest possible probability of correct decoding for block codes of any given rate above capacity have been given by Dueck and Korner. Their method is extended to show that the same bounds also hold in the presence of noiseless feedback.
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- 1982
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15. Comparing clinical practice habits among obesity medicine physicians by patient, physician and clinic factors.
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Rajagopal S, Wickham EP 3rd, Reid TJ, Brittan DR, Korner J, and Gudzune KA
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Background: While clinical practice habits vary by patient, physician and clinic factors in primary care, limited research has examined whether differences exist in obesity medicine. Our objective was to compare practice habits by such factors among obesity medicine physicians certified by the American Board of Obesity Medicine (ABOM)., Methods: We conducted secondary analyses of cross-sectional data from the 2023 ABOM Practice Analysis Validation Survey. We included three obesity medicine practice habits - prescribing anti-obesity medications (AOMs), off-label prescribing of medications for weight reduction, and obesity medicine clinical practice hours (4-20 h/week versus >20 h/week). We included patient (patient population), physician (primary medical specialty, years of obesity medicine experience) and clinic factors (practice setting, geographic catchment, accepts insurance for obesity care). We conducted bivariate analyses using Χ
2 tests., Results: Among 565 ABOM-certified physicians, 71.5 % had primary medical specialties within primary care and 9.2 % predominantly treated children/adolescents with obesity. Overall, 97.5 % prescribed AOMs and 85.1 % prescribed off-label medications for weight reduction. Fewer physicians who predominantly treated children/adolescents prescribed AOMs compared to physicians with no or limited treatment of children (88.5 % versus 98.4 % and 98.5 %, respectively; p < 0.001). Overall, 41.4 % reported practicing obesity medicine >20 h/week, which was more likely to occur as years of obesity medicine experience increased (i.e., 21.9 % among physicians with 1-2 years of experience versus 58.5 % with 10+ years; p < 0.001). No significant differences in practice habits occurred by primary medical specialty, practice setting, geographic catchment, or accepting insurance., Conclusion: Our findings may suggest that ABOM-certified physicians have consistent obesity medication prescribing practices regardless of physician or clinic factors, which may be particularly important to patients seeking pharmacologic treatment. Most ABOM-certified physicians who predominantly treat children/adolescents prescribe obesity medications. These current rates are relatively higher than prior findings among pediatric ABOM-certified physicians, which might help support pharmacologic access for pediatric patients., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kimberly Gudzune reports a relationship with 10.13039/501100004191Novo Nordisk that includes: consulting or advisory, funding grants, and travel reimbursement. Kimberly Gudzune reports a relationship with Eli Lilly and Company that includes: consulting or advisory and travel reimbursement. Edmond Wickham III reports a relationship with Novo Nordisk Inc that includes: funding grants. Judith Korner reports a relationship with Morphic Medical that includes: consulting or advisory. Judith Korner reports a relationship with Gila Therapeutics that includes: consulting or advisory. Judith Korner reports a relationship with Found that includes: consulting or advisory. Judith Korner reports a relationship with Apotex Inc that includes: consulting or advisory. Tirissa Reid received royalties from UpToDate. Judith Korner received royalties from UpToDate. Kimberly Gudzune received royalties from the Johns Hopkins ACG System. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025 The Authors.)- Published
- 2025
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16. Duties, tasks, knowledge and skills of an obesity medicine physician: A practice analysis.
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Gudzune KA, Brittan DR, Cadle AW, Reid TJ, Wickham EP 3rd, and Korner J
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Background: Given the evolving nature of obesity medicine, periodic evaluation of its clinical practice is needed to ensure that certification requirements address real-world experience. Practice analysis is a systematic approach to define a field's body of knowledge, and its results can inform the content outline and examination blueprint for a certification examination. This study describes the 2023 practice analysis conducted by the American Board of Obesity Medicine (ABOM)., Methods: Initially, 14 obesity medicine physicians participated in a practice analysis panel, resulting in 3 duties and 30 tasks required for competent practice of obesity medicine physicians. Each task included steps, knowledge, skills, and abilities needed to perform the task. ABOM then recruited 645 certified obesity medicine physicians from its database to participate in a validation survey to rate the frequency [scale: never (0) to very frequently (5)] and importance [scale: not important (0) to very important (3)] of each task. Survey participants could also provide open-ended comments., Results: Among validation survey participants (n = 645), the most common primary medical specialties reported were internal medicine (46.0 %), family medicine (33.8 %), and pediatrics (11.2 %). Years practicing obesity medicine varied with 45.3 % reporting 1-4 years, 26.0 % 5-9 years, and 28.7 % ≥ 10 years in practice. Most tasks were performed frequently (mean score ≥4.0) and rated as important (mean score ≥2.0). All tasks were retained based on the frequency and importance ratings. Survey results informed the weighting in the examination blueprint., Conclusion: There was consensus among practicing ABOM-certified physicians who participated in the validation survey in the tasks required for competent obesity medicine practice. Our practice analysis approach was a structured process that engaged obesity medicine physicians and captured the breadth and depth of knowledge required for obesity medicine. The new content outline and examination blueprint developed will be implemented with the 2025 ABOM certification exam administration., (© 2024 The Authors.)
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- 2024
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17. Letter to the Editor of Obesity Pillars from the American Board of Obesity Medicine.
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Brittan D, Gudzune KA, Wickham EP, and Korner J
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Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: DB and KAG are the ABOM Executive Director and Medical Director, respectively. JK is Chair and EPW is Vice-Chair of the ABOM Board of Directors. KAG, EPW and JK are ABOM Diplomates. DB reports no other relationships. KAG also reports the following relationships: Novo Nordisk Inc (consulting/advisory; grant funding) and Eli Lilly and Company (consulting/advisory). EPW also reports the following relationships: 10.13039/100015519WW International Inc (grant funding); 10.13039/100011302Children's Hospital Foundation (grant funding); and Foundation for Advanced Education in the Sciences (speaking/lecture fees). JK also reports the following relationships: Gila Therapeutics (consulting/advisory); GI Dynamics (consulting/advisory); Found Health (consulting/advisory; equity/stocks); Digma Medical (equity/stocks); and Servier Laboratories (paid expert testimony).
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- 2023
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18. Risk factor management of atrial fibrillation using mHealth: The Atrial Fibrillation - Helping Address Care with Remote Technology (AF-HEART) Pilot Study.
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Mitrani LR, Goldenthal I, Leskowitz J, Wan EY, Dizon J, Saluja D, Creber RM, Turchioe MR, Sciacca RR, Garan H, Hickey KT, Korner J, and Biviano AB
- Abstract
Background: Personalized treatment of atrial fibrillation (AF) risk factors using mHealth and telehealth may improve patient outcomes., Objective: The purpose of this study was to assess the feasibility of the Atrial Fibrillation Helping Address Care with Remote Technology (AF-HEART) intervention on the following patient outcomes: (1) heart rhythm tracking; (2) weight, alcohol, blood pressure (BP), and sleep apnea reduction; (3) AF symptom reduction; and (4) quality-of-life (QOL) improvement., Methods: A total of 20 patients with AF undergoing antiarrhythmic therapy, cardioversion, and/or catheter ablation were enrolled and followed for 6 months. The AF-HEART intervention included remote heart rhythm, weight, and BP tracking; televisits with a dietician focusing on AF risk factors; and referrals for sleep apnea and hypertension treatment., Results: Patients transmitted a median of 181 rhythm recordings during the 6-month follow-up period. Patients lost an average of 3.5 kilograms at 6 months ( P = .005). Patients had improved SF-12 scores ( P = .01), AFSS score ( P = .01), EQ-5D score ( P = .006), and AFEQT Global Score ( P = .03). There was significant correlation between weight loss and decrease in symptom severity (r = -0.45, P = .05), and between % weight loss and decrease in symptom severity (r = -0.49, P = .03)., Conclusion: This study described the feasibility of the AF-HEART intervention for (1) consistent remote tracking of heart rhythm, weight, and BP; (2) achievement of weight loss; (3) reduction of symptoms; and (4) improvement in QOL. Expansion to a larger randomized study is planned., (© 2021 Heart Rhythm Society.)
- Published
- 2021
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19. Obesity is independently associated with septic shock, renal complications, and mortality in a multiracial patient cohort hospitalized with COVID-19.
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Page-Wilson G, Arakawa R, Nemeth S, Bell F, Girvin Z, Tuohy MC, Lauring M, Laferrère B, Reyes-Soffer G, Natarajan K, Chen R, Kurlansky P, and Korner J
- Subjects
- Adult, Aged, Aged, 80 and over, COVID-19 mortality, Female, Hospital Mortality, Hospitalization, Humans, Kidney Diseases mortality, Male, Middle Aged, New York City, Obesity mortality, Retrospective Studies, Risk Factors, Shock, Septic mortality, Survival Rate, COVID-19 complications, Kidney Diseases etiology, Obesity complications, Shock, Septic etiology
- Abstract
Background: Obesity has emerged as a risk factor for severe coronavirus disease 2019 (COVID-19) infection. To inform treatment considerations the relationship between obesity and COVID-19 complications and the influence of race, ethnicity, and socioeconomic factors deserves continued attention., Objective: To determine if obesity is an independent risk factor for severe COVID-19 complications and mortality and examine the relationship between BMI, race, ethnicity, distressed community index and COVID-19 complications and mortality., Methods: A retrospective cohort study of 1,019 SARS-CoV-2 positive adult admitted to an academic medical center (n = 928) and its affiliated community hospital (n-91) in New York City from March 1 to April 18, 2020., Results: Median age was 64 years (IQR 52-75), 58.7% were men, 23.0% were Black, and 52.8% were Hispanic. The prevalence of overweight and obesity was 75.2%; median BMI was 28.5 kg/m2 (25.1-33.0). Over the study period 23.7% patients died, 27.3% required invasive mechanical ventilation, 22.7% developed septic shock, and 9.1% required renal replacement therapy (RRT). In the multivariable logistic regression model, BMI was associated with complications including intubation (Odds Ratio [OR]1.03, 95% Confidence Interval [CI]1.01-1.05), septic shock (OR 1.04, CI 1.01-1.06), and RRT (OR1.07, CI 1.04-1.10), and mortality (OR 1.04, CI 1.01-1.06). The odds of death were highest among those with BMI ≥ 40 kg/m2 (OR 2.05, CI 1.04-4.04). Mortality did not differ by race, ethnicity, or socioeconomic distress score, though Black and Asian patients were more likely to require RRT., Conclusions and Relevance: Severe complications of COVID-19 and death are more likely in patients with obesity, independent of age and comorbidities. While race, ethnicity, and socioeconomic status did not impact COVID-19 related mortality, Black and Asian patients were more likely to require RRT. The presence of obesity, and in some instances race, should inform resource allocation and risk stratification in patients hospitalized with COVID-19., Competing Interests: Gabrielle Page-Wilson has served as a consultant for Strongbridge Biopharma and Adare Pharmaceuticals and has served on scientific advisory boards for Strongbridge Biopharma and Recordati Rare Diseases, Inc. Judith Korner MD, PhD is a consultant for Digma Medical, Found Health Inc. and a scientific advisory board member for GI Dynamics. We would like to confirm that these competing interests do not alter our adherence to all PLOS ONE policies on sharing data and materials.
- Published
- 2021
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20. Prospective study of gut hormone and metabolic changes after laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass.
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Arakawa R, Febres G, Cheng B, Krikhely A, Bessler M, and Korner J
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- Adult, Aged, Blood Glucose metabolism, Female, Homeostasis, Humans, Male, Middle Aged, Prospective Studies, Gastrectomy, Gastric Bypass, Gastrointestinal Tract metabolism, Hormones blood, Laparoscopy
- Abstract
Background: Laparoscopic sleeve gastrectomy (SG) has surpassed Roux-en-Y gastric bypass (RYGB) as the most prevalent bariatric procedure worldwide. While RYGB and SG demonstrate equivalent short-term weight loss, long-term weight loss tends to be greater after RYGB. Differences in the effect of these procedures on gastrointestinal hormones that regulate energy homeostasis are felt to partially underlie differences in outcomes. The objective of this study was to prospectively quantify blood levels of gut hormones of energy and glucose homeostasis at one year follow up to delineate possible reasons for greater efficacy of RYGB over SG in achieving weight loss., Methods: Patients undergoing SG (n = 19) and RYGB (n = 40) were studied before surgery and at 2,12, 26, and 52 weeks postoperatively. Blood samples drawn in the fasted state and after a liquid mixed meal were assayed at baseline, 26, and 52 weeks for peptide YY (PYY), glucagon-like peptide-1 (GLP-1), ghrelin, insulin, glucose, and leptin. Fasting and postprandial appetitive sensations were assessed by visual analog scale., Results: At 1 year there was greater weight loss in RYGB compared with SG patients (30% vs 27%; P = 0.03). Area under the curve (AUC) after the mixed meal for PYY was greater in RYGB patients (P<0.001). RYGB patients had significant increases in GLP-1 AUC compared to baseline (P = 0.002). Ghrelin levels decreased only after SG compared to baseline (P<0.001) but were not significantly different from RYGB. There was a trend toward decreased sweet cravings in RYGB patients (P = 0.056)., Conclusions: Differences in gastrointestinal hormones that regulate energy and glucose homeostasis are a possible mechanism for greater efficacy of RYGB compared to SG., Competing Interests: The authors have read the journal’s policy and have the following competing interests: JK participates on advisory boards for Digma Medical, GI Dynamics, and Esquagama. She receives financial compensation and stock options from GI Dynamics and Esqagama. She receives stock options from Digma Medical. She does not receive financial support via salary for her participation on these advisory boards. MB is a founder of Endobetes and has a patent application titled “Lumen Reinforcement and Anchoring System” application no. 16/046592. The patent is focused on a method to anchor devices in the GI tract and is assigned to Endobetes, a medical device startup with a goal of developing endoscopic devices for treatment of obesity and diabetes. MB owns stock in Endobetes and has an equity position, but does not receive financial support via salary as the founder of Endobetes. AK is a consultant for Intuitive Surgical, CLG, and CSATs. He was paid by Intuitive surgical to give several talks and serve as an OR surgery instructor/proctor. CLG is a third party consulting firm that connects firms with experts and AK was paid to offer an opinion on topics related to robotic surgery. He was paid by CSATs to review videos of surgeries and provide critique to the surgeons. He does not receive any financial support via salary or research funding from these firms. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
- Published
- 2020
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21. Joint international consensus statement for ending stigma of obesity.
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Rubino F, Puhl RM, Cummings DE, Eckel RH, Ryan DH, Mechanick JI, Nadglowski J, Ramos Salas X, Schauer PR, Twenefour D, Apovian CM, Aronne LJ, Batterham RL, Berthoud HR, Boza C, Busetto L, Dicker D, De Groot M, Eisenberg D, Flint SW, Huang TT, Kaplan LM, Kirwan JP, Korner J, Kyle TK, Laferrère B, le Roux CW, McIver L, Mingrone G, Nece P, Reid TJ, Rogers AM, Rosenbaum M, Seeley RJ, Torres AJ, and Dixon JB
- Subjects
- Body Weight physiology, Humans, International Cooperation, Universities organization & administration, Universities standards, Consensus, Obesity psychology, Obesity therapy, Practice Guidelines as Topic, Social Stigma, Weight Prejudice prevention & control
- Abstract
People with obesity commonly face a pervasive, resilient form of social stigma. They are often subject to discrimination in the workplace as well as in educational and healthcare settings. Research indicates that weight stigma can cause physical and psychological harm, and that affected individuals are less likely to receive adequate care. For these reasons, weight stigma damages health, undermines human and social rights, and is unacceptable in modern societies. To inform healthcare professionals, policymakers, and the public about this issue, a multidisciplinary group of international experts, including representatives of scientific organizations, reviewed available evidence on the causes and harms of weight stigma and, using a modified Delphi process, developed a joint consensus statement with recommendations to eliminate weight bias. Academic institutions, professional organizations, media, public-health authorities, and governments should encourage education about weight stigma to facilitate a new public narrative about obesity, coherent with modern scientific knowledge.
- Published
- 2020
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22. A role for foregut tyrosine metabolism in glucose tolerance.
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Korner J, Cline GW, Slifstein M, Barba P, Rayat GR, Febres G, Leibel RL, Maffei A, and Harris PE
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- Animals, Cell Line, Cross-Sectional Studies, Female, Glucose Tolerance Test, Homeostasis, Humans, Insulin metabolism, Insulin-Secreting Cells metabolism, Male, Nutrients, Obesity blood, Obesity surgery, Postprandial Period, Rats, Rats, Inbred Lew, Swine, Tyrosine pharmacology, Aromatic-L-Amino-Acid Decarboxylases metabolism, Blood Glucose analysis, Dopamine metabolism, Gastrointestinal Tract metabolism, Levodopa metabolism, Tyrosine metabolism, Tyrosine 3-Monooxygenase metabolism
- Abstract
Objective: We hypothesized that DA and L-DOPA derived from nutritional tyrosine and the resultant observed postprandial plasma excursions of L-DOPA and DA might affect glucose tolerance via their ability to be taken-up by beta cells and inhibit glucose-stimulated β-cell insulin secretion., Methods: To investigate a possible circuit between meal-stimulated 3,4-dihydroxy-L-phenylalanine (L-DOPA) and dopamine (DA) production in the GI tract and pancreatic β-cells, we: 1) mapped GI mucosal expression of tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase (AADC); 2) measured L-DOPA and DA content of GI mucosal tissues following meal challenges with different L-tyrosine (TYR) content, 3) determined whether meal TYR content impacts plasma insulin and glucose excursions; and 4) characterized postprandial plasma excursions of L-DOPA and DA in response to meal tyrosine content in rodents and a population of bariatric surgery patients. Next, we characterized: 1) the metabolic transformation of TYR and L-DOPA into DA in vitro using purified islet tissue; 2) the metabolic transformation of orally administrated stable isotope labeled TYR into pancreatic DA, and 3) using a nuclear medicine technique, we studied endocrine beta cells in situ release and binding of DA in response to a glucose challenge., Results: We demonstrate in rodents that intestinal content and circulatory concentrations L-DOPA and DA, plasma glucose and insulin are responsive to the tyrosine (TYR) content of a test meal. Intestinal expression of two enzymes, Tyrosine hydroxylase (TH) and Aromatic Amino acid Decarboxylase (AADC), essential to the transformation of TYR to DA was mapped and the metabolism of metabolism of TYR to DA was traced in human islets and a rodent beta cell line in vitro and from gut to the pancreas in vivo. Lastly, we show that β cells secrete and bind DA in situ in response to glucose stimulation., Conclusions: We provide proof-of-principle evidence for the existence of a novel postprandial circuit of glucose homeostasis dependent on nutritional tyrosine. DA and L-DOPA derived from nutritional tyrosine may serve to defend against hypoglycemia via inhibition of glucose-stimulated β-cell insulin secretion as proposed by the anti-incretin hypothesis., (Copyright © 2019 The Authors. Published by Elsevier GmbH.. All rights reserved.)
- Published
- 2019
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23. Sleeve Gastrectomy and Roux-en-Y Gastric Bypass Achieve Similar Early Improvements in Beta-cell Function in Obese Patients with Type 2 Diabetes.
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Mullally JA, Febres GJ, Bessler M, and Korner J
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- Adolescent, Adult, Aged, Blood Glucose analysis, Body Mass Index, Diabetes Mellitus, Type 2 complications, Female, Glucose Tolerance Test, Humans, Male, Middle Aged, Obesity complications, Treatment Outcome, Weight Loss, Young Adult, Diabetes Mellitus, Type 2 surgery, Gastrectomy, Gastric Bypass, Insulin-Secreting Cells physiology, Obesity surgery
- Abstract
Bariatric surgery is a treatment option for obese patients with type 2 diabetes mellitus (T2DM). Although sleeve gastrectomy (SG) is growing in favor, some randomized trials show less weight loss and HbA1c improvement compared with Roux-en-Y gastric bypass (RYGB). The study objective was to compare changes in beta-cell function with similar weight loss after SG and RYGB in obese patients with T2DM. Subjects undergoing SG or RYGB were studied with an intravenous glucose tolerance test before surgery and at 5-12% weight loss post-surgery. The primary endpoint was change in the disposition index (DI). Baseline BMI, HbA1c, and diabetes-duration were similar between groups. Mean total weight loss percent was similar (8.4% ± 0.4, p = 0.22) after a period of 21.0 ± 1.7 days. Changes in fasting glucose, acute insulin secretion (AIR), and insulin sensitivity (Si) were similar between groups. Both groups showed increases from baseline to post-surgery in DI (20.2 to 163.3, p = 0.03 for SG; 31.2 to 232.9, p = 0.02 for RYGB) with no significant difference in the change in DI between groups (p = 0.53). Short-term improvements in beta-cell function using an IVGTT were similar between SG and RYGB. It remains unclear if longer-term outcomes are better after RYGB due to greater weight loss and/or other factors.
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- 2019
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24. Roux-en-Y Gastric Bypass Is Associated With Hyperinsulinemia But Not Increased Maximal β -Cell Function.
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Georgia A, Asnis MCC, Febres G, Tsang A, Bessler M, and Korner J
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Context: Roux-en-Y gastric bypass (RYGB) is associated with postprandial hyperinsulinemia., Objective: This study assessed whether increased blood insulin levels may be due to an increase in maximal β -cell function., Design Setting and Participants: We performed a cross-sectional study at Columbia University Medical Center, New York, New York. Subjects without a history of diabetes were studied after surgery (n = 12) and were compared with nonsurgical controls (n = 10) who were mean matched for body mass index, insulin sensitivity, and hemoglobin A1c and with nonobese controls (n = 8)., Methods: Subjects underwent a mixed-meal tolerance test and on a separate day an intravenous glucose tolerance test followed by a hyperglycemic clamp (450 mg/dL; 25 mM blood glucose) and arginine stimulation. The main outcome measure was maximal insulin secretion quantified after arginine stimulation (AinsRmax)., Results: The RYGB group exhibited greater peak postprandial glucose levels and fourfold greater peak insulin levels than control groups; however, there were no significant differences in insulinogenic index or AinsRmax. Another finding was significantly greater postprandial glucagon levels in the RYGB group compared with controls., Conclusions: Our results suggest that after RYGB, the increase in postprandial levels of insulin are not due to changes in maximal β -cell function but appear to be an appropriate response to altered nutrient flow and absorption.
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- 2019
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25. Phase II Feasibility Study of a Weight Loss Intervention in Female Breast and Colorectal Cancer Survivors (SWOG S1008).
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Greenlee H, Lew DL, Hershman DL, Newman VA, Hansen L, Hartman SJ, Korner J, Shi Z, Sardo Molmenti CL, Sayegh A, Fehrenbacher L, Lo S, Klemp J, Rinn K, Robertson JM, Unger J, Gralow J, Albain K, Krouse R, and Fabian C
- Subjects
- Colorectal Neoplasms psychology, Feasibility Studies, Female, Humans, Middle Aged, Obesity psychology, Breast Neoplasms therapy, Cancer Survivors psychology, Colorectal Neoplasms therapy, Diet methods, Obesity therapy, Weight Loss physiology
- Abstract
Objective: This study aimed to test the feasibility of a 12-month weight loss intervention using telephone-based counseling plus community-situated physical activity (PA) in female breast cancer (BC) and colorectal cancer (CRC) survivors., Methods: This multisite cooperative group study enrolled sedentary, female, postmenopausal BC and CRC survivors with BMI ≥ 25 kg/m
2 to receive 12-month fitness center memberships and telephone counseling encouraging 150 min/wk of PA and a 500-kcal/ddecrease in energy intake. Feasibility criteria included accrual, adherence, and retention. Target weight loss was ≥ 5%., Results: Among 25 BC survivors, median baseline BMI was 37.2 (range: 27.7-54.6), accrual occurred in 10 months, 60% and 28% met diet and exercise goals, 80% provided 12-month measures, and average weight loss was 7.6% (95% CI: -3.9%, 19.2%). Among 23 CRC survivors, median BMI was 31.8 (range: 26.4-48.7), accrual occurred in 24 months, 61% and 17% met diet and exercise goals, 87% provided measures, and average weight loss was 2.5% (95% CI: -8.2%, 13.3%)., Conclusions: It is feasible to recruit and retain BC survivors in a cooperative group diet and PA weight loss trial. BC survivors achieved clinically meaningful weight loss but did not meet a priori adherence goals. In CRC survivors, recruitment was more difficult, and the intervention was less effective., (© 2018 The Obesity Society.)- Published
- 2018
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26. A direct tissue-grafting approach to increasing endogenous brown fat.
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Blumenfeld NR, Kang HJ, Fenzl A, Song Z, Chung JJ, Singh R, Johnson R, Karakecili A, Feranil JB, Rossen NS, Zhang V, Jaggi S, McCarty B, Bessler S, Schwartz GJ, Grant R, Korner J, Kiefer FW, Gillette BM, and Sia SK
- Subjects
- Adiposity, Animals, Body Weight, Energy Metabolism, Humans, Mice, Mice, Inbred C57BL, Mitochondria, Phenotype, Transplantation, Autologous, Adipose Tissue, Brown transplantation, Adipose Tissue, White, Obesity therapy
- Abstract
There is widespread evidence that increasing functional mass of brown adipose tissue (BAT) via browning of white adipose tissue (WAT) could potentially counter obesity and diabetes. However, most current approaches focus on administration of pharmacological compounds which expose patients to highly undesirable side effects. Here, we describe a simple and direct tissue-grafting approach to increase BAT mass through ex vivo browning of subcutaneous WAT, followed by re-implantation into the host; this cell-therapy approach could potentially act synergistically with existing pharmacological approaches. With this process, entitled "exBAT", we identified conditions, in both mouse and human tissue, that convert whole fragments of WAT to BAT via a single step and without unwanted off-target pharmacological effects. We show that ex vivo, exBAT exhibited UCP1 immunostaining, lipid droplet formation, and mitochondrial metabolic activity consistent with native BAT. In mice, exBAT exhibited a highly durable phenotype for at least 8 weeks. Overall, these results enable a simple and scalable tissue-grafting strategy, rather than pharmacological approaches, for increasing endogenous BAT and studying its effect on host weight and metabolism.
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- 2018
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27. Evaluation of CSF and plasma biomarkers of brain melanocortin activity in response to caloric restriction in humans.
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Page-Wilson G, Nguyen KT, Atalayer D, Meece K, Bainbridge HA, Korner J, Gordon RJ, Panigrahi SK, White A, Smiley R, and Wardlaw SL
- Subjects
- Adult, Agouti-Related Protein blood, Case-Control Studies, Enzyme-Linked Immunosorbent Assay, Fasting blood, Fasting cerebrospinal fluid, Female, Humans, Insulin Resistance, Leptin blood, Male, Melanocortins metabolism, Middle Aged, Obesity blood, Pro-Opiomelanocortin blood, Radioimmunoassay, Young Adult, beta-Endorphin blood, Agouti-Related Protein cerebrospinal fluid, Brain metabolism, Caloric Restriction, Insulin blood, Leptin cerebrospinal fluid, Obesity cerebrospinal fluid, Pro-Opiomelanocortin cerebrospinal fluid, beta-Endorphin cerebrospinal fluid
- Abstract
The melanocortin neuronal system, which consists of hypothalamic proopiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, is a leptin target that regulates energy balance and metabolism, but studies in humans are limited by a lack of reliable biomarkers to assess brain melanocortin activity. The objective of this study was to measure the POMC prohormone and its processed peptide, β-endorphin (β-EP), in cerebrospinal fluid (CSF) and AgRP in CSF and plasma after calorie restriction to validate their utility as biomarkers of brain melanocortin activity. CSF and plasma were obtained from 10 lean and obese subjects after fasting (40 h) and refeeding (24 h), and from 8 obese subjects before and after 6 wk of dieting (800 kcal/day) to assess changes in neuropeptide and hormone levels. After fasting, plasma leptin decreased to 35%, and AgRP increased to 153% of baseline. During refeeding, AgRP declined as leptin increased; CSF β-EP increased, but POMC did not change. Relative changes in plasma and CSF leptin were blunted in obese subjects. After dieting, plasma and CSF leptin decreased to 46% and 70% of baseline, CSF POMC and β-EP decreased, and plasma AgRP increased. At baseline, AgRP correlated negatively with insulin and homeostasis model assessment (HOMA-IR), and positively with the Matsuda index. Thus, following chronic calorie restriction, POMC and β-EP declined in CSF, whereas acutely, only β-EP changed. Plasma AgRP, however, increased after both acute and chronic calorie restriction. These results support the use of CSF POMC and plasma AgRP as biomarkers of hypothalamic melanocortin activity and provide evidence linking AgRP to insulin sensitivity., (Copyright © 2017 the American Physiological Society.)
- Published
- 2017
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28. Durability of Addition of Roux-en-Y Gastric Bypass to Lifestyle Intervention and Medical Management in Achieving Primary Treatment Goals for Uncontrolled Type 2 Diabetes in Mild to Moderate Obesity: A Randomized Control Trial.
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Ikramuddin S, Korner J, Lee WJ, Bantle JP, Thomas AJ, Connett JE, Leslie DB, Inabnet WB 3rd, Wang Q, Jeffery RW, Chong K, Chuang LM, Jensen MD, Vella A, Ahmed L, Belani K, Olofson AE, Bainbridge HA, and Billington CJ
- Subjects
- Adult, Blood Glucose analysis, Blood Pressure, Cholesterol, LDL blood, Combined Modality Therapy, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 etiology, Female, Glycated Hemoglobin analysis, Humans, Hypoglycemic Agents administration & dosage, Life Style, Male, Middle Aged, Obesity blood, Obesity complications, Remission Induction methods, Taiwan, Time Factors, Treatment Outcome, United States, Weight Loss physiology, Diabetes Mellitus, Type 2 therapy, Gastric Bypass methods, Goals, Obesity therapy, Risk Reduction Behavior
- Abstract
Objective: We compared 3-year achievement of an American Diabetes Association composite treatment goal (HbA1c <7.0%, LDL cholesterol <100 mg/dL, and systolic blood pressure <130 mmHg) after 2 years of intensive lifestyle-medical management intervention, with and without Roux-en-Y gastric bypass, with one additional year of usual care., Research Design and Methods: A total of 120 adult participants, with BMI 30.0-39.9 kg/m(2) and HbA1c ≥8.0%, were randomized 1:1 to two treatment arms at three clinical sites in the U.S. and one in Taiwan. All patients received the lifestyle-medical management intervention for 24 months; half were randomized to also receive gastric bypass., Results: At 36 months, the triple end point goal was met in 9% of lifestyle-medical management patients and 28% of gastric bypass patients (P = 0.01): 10% and 19% lower than at 12 months. Mean (SD) HbA1c values at 3 years were 8.6% (3.5) and 6.7% (2.0) (P < 0.001). No lifestyle-medical management patient had remission of diabetes at 36 months, whereas 17% of gastric bypass patients had full remission and 19% had partial remission. Lifestyle-medical management patients used more medications than gastric bypass patients: mean (SD) 3.8 (3.3) vs. 1.8 (2.4). Percent weight loss was mean (SD) 6.3% (16.1) in lifestyle-medical management vs. 21.0% (14.5) in gastric bypass (P < 0.001). Over 3 years, 24 serious or clinically significant adverse events were observed in lifestyle-medical management vs. 51 with gastric bypass., Conclusions: Gastric bypass is more effective than lifestyle-medical management intervention in achieving diabetes treatment goals, mainly by improved glycemic control. However, the effect of surgery diminishes with time and is associated with more adverse events., (© 2016 by the American Diabetes Association.)
- Published
- 2016
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29. Preserved Insulin Secretory Capacity and Weight Loss Are the Predominant Predictors of Glycemic Control in Patients With Type 2 Diabetes Randomized to Roux-en-Y Gastric Bypass.
- Author
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Nguyen KT, Billington CJ, Vella A, Wang Q, Ahmed L, Bantle JP, Bessler M, Connett JE, Inabnet WB, Thomas A, Ikramuddin S, and Korner J
- Subjects
- Adiponectin metabolism, C-Peptide metabolism, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 metabolism, Female, Gastric Inhibitory Polypeptide metabolism, Glucagon metabolism, Glucagon-Like Peptide 1 metabolism, Glucagon-Like Peptide 2 metabolism, Glycated Hemoglobin metabolism, Humans, Insulin Resistance, Insulin Secretion, Male, Middle Aged, Obesity complications, Obesity metabolism, Treatment Outcome, Blood Glucose metabolism, Diabetes Mellitus, Type 2 drug therapy, Gastric Bypass, Hypoglycemic Agents therapeutic use, Insulin metabolism, Insulin-Secreting Cells metabolism, Obesity surgery, Weight Loss
- Abstract
Improvement in type 2 diabetes after Roux-en-Y gastric bypass (RYGB) has been attributed partly to weight loss, but mechanisms beyond weight loss remain unclear. We performed an ancillary study to the Diabetes Surgery Study to assess changes in incretins, insulin sensitivity, and secretion 1 year after randomization to lifestyle modification and intensive medical management (LS/IMM) alone (n = 34) or in conjunction with RYGB (n = 34). The RYGB group lost more weight and had greater improvement in HbA1c. Fasting glucose was lower after RYGB than after LS/IMM, although the glucose area under the curve decreased comparably for both groups. Insulin sensitivity increased in both groups. Insulin secretion was unchanged after LS/IMM but decreased after RYGB, except for a rapid increase during the first 30 min after meal ingestion. Glucagon-like peptide 1 (GLP-1) was substantially increased after RYGB, while gastric inhibitory polypeptide and glucagon decreased. Lower HbA1c was most strongly correlated with the percentage of weight loss for both groups. At baseline, a greater C-peptide index and 90-min postprandial C-peptide level were predictive of lower HbA1c at 1 year after RYGB. β-Cell glucose sensitivity, which improved only after RYGB, and improved disposition index were associated with lower HbA1c in both groups, independent of weight loss. Weight loss and preserved β-cell function both predominantly determine the greatest glycemic benefit after RYGB., (© 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)
- Published
- 2015
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30. Adipose tissue macrophages promote myelopoiesis and monocytosis in obesity.
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Nagareddy PR, Kraakman M, Masters SL, Stirzaker RA, Gorman DJ, Grant RW, Dragoljevic D, Hong ES, Abdel-Latif A, Smyth SS, Choi SH, Korner J, Bornfeldt KE, Fisher EA, Dixit VD, Tall AR, Goldberg IJ, and Murphy AJ
- Subjects
- Animals, Bone Marrow metabolism, Carrier Proteins metabolism, Cell Proliferation physiology, Humans, Inflammasomes metabolism, Interleukin-1beta metabolism, Male, Mice, Mice, Inbred C57BL, Myeloid Differentiation Factor 88 metabolism, NLR Family, Pyrin Domain-Containing 3 Protein, Neutrophils metabolism, Receptors, Interleukin-1 metabolism, Toll-Like Receptor 4 metabolism, Adipose Tissue metabolism, Macrophages metabolism, Monocytes metabolism, Myelopoiesis physiology, Obesity metabolism
- Abstract
Obesity is associated with infiltration of macrophages into adipose tissue (AT), contributing to insulin resistance and diabetes. However, relatively little is known regarding the origin of AT macrophages (ATMs). We discovered that murine models of obesity have prominent monocytosis and neutrophilia, associated with proliferation and expansion of bone marrow (BM) myeloid progenitors. AT transplantation conferred myeloid progenitor proliferation in lean recipients, while weight loss in both mice and humans (via gastric bypass) was associated with a reversal of monocytosis and neutrophilia. Adipose S100A8/A9 induced ATM TLR4/MyD88 and NLRP3 inflammasome-dependent IL-1β production. IL-1β interacted with the IL-1 receptor on BM myeloid progenitors to stimulate the production of monocytes and neutrophils. These studies uncover a positive feedback loop between ATMs and BM myeloid progenitors and suggest that inhibition of TLR4 ligands or the NLRP3-IL-1β signaling axis could reduce AT inflammation and insulin resistance in obesity., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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31. Recombinant human leptin does not alter gut hormone levels after gastric bypass but may attenuate sweet cravings.
- Author
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Conroy R, Febres G, McMahon DJ, Thorner MO, Gaylinn BD, Conwell I, Aronne L, and Korner J
- Abstract
Bariatric surgery improves glucose homeostasis and alters gut hormones partly independent of weight loss. Leptin plays a role in these processes; levels are decreased following bariatric surgery, creating a relative leptin insufficiency. We previously showed that leptin administration in a weight-reduced state after Roux-en-Y gastric bypass (RYGB) caused no further weight loss. Here, we discuss the impact of leptin administration on gut hormones, glucostasis, and appetite. Weight stable women after RYGB were randomized to receive placebo or recombinant human metreleptin (0.05 mg/kg twice daily). At weeks 0 and 16, a liquid meal challenge was performed. Glucose, insulin, C-peptide, GLP-1, PYY, glucagon, and ghrelin (total, acyl, and desacyl) were measured fasting and postprandially. Appetite was assessed using a visual analog scale. Mean post-op period was 53 ± 2.3 months; mean BMI was 34.6 ± 0.2 kg/m(2). At 16 weeks, there was no significant change in weight within or between groups. Fasting PYY was significantly different between groups and the leptin group had lower sweets craving at week 16 than the placebo group (P < 0.05). No other differences were observed. Leptin replacement does not alter gut hormones or glucostasis but may diminish sweet cravings compared to placebo in this population of post-RYGB women.
- Published
- 2014
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32. Hormonal responses and test meal intake among obese teenagers before and after laparoscopic adjustable gastric banding.
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Sysko R, Devlin MJ, Schebendach J, Tanofsky-Kraff M, Zimmerli E, Korner J, Yanovski JA, Zitsman JL, and Walsh BT
- Subjects
- Adolescent, Area Under Curve, Bariatric Surgery, Case-Control Studies, Fasting, Female, Ghrelin blood, Humans, Leptin blood, Male, Meals, Peptide YY blood, Postprandial Period, Prospective Studies, Surveys and Questionnaires, Feeding Behavior, Laparoscopy, Obesity blood, Obesity surgery
- Abstract
Background: Relatively little is known about changes in eating behavior or hormonal responses to food after bariatric surgery in adolescents., Objective: This study compared eating behavior and hormones among adolescents in a bariatric surgery program with those in nonoverweight control adolescents and evaluated changes before and after laparoscopic adjustable gastric banding (LAGB)., Design: Fasting leptin, peptide YY (PYY), and ghrelin concentrations were obtained, and postprandial ghrelin and PYY area under the curve (AUC) were assessed after a single-item breakfast. Intake from an ad libitum lunchtime multi-item meal was measured., Results: Compared with controls (n = 9), all presurgical candidates (n = 20) had significantly greater fasting leptin, lower fasting ghrelin, and lower AUC ghrelin but similar PYY and AUC PYY. Preoperative candidates did not differ from controls in total energy consumed during the test meal. Postoperatively, among the 11 participants with data both before and after surgery, BMI (in kg/m(2)) decreased by 3.5 (P < 0.001), significantly less energy was consumed in the test meal, and a smaller number of foods were selected. AUC ghrelin and PYY did not significantly change before or after LAGB., Conclusions: Few significant short-term changes were observed in appetitive hormones after LAGB. It is unclear whether objective measures of eating behavior will prove useful in evaluating the impact of bariatric surgery on outcomes. This trial was registered at clinicaltrials.gov as CT00764127.
- Published
- 2013
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33. Very low-calorie diet mimics the early beneficial effect of Roux-en-Y gastric bypass on insulin sensitivity and β-cell Function in type 2 diabetic patients.
- Author
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Jackness C, Karmally W, Febres G, Conwell IM, Ahmed L, Bessler M, McMahon DJ, and Korner J
- Subjects
- Adolescent, Adult, Aged, Female, Humans, Male, Middle Aged, Young Adult, Caloric Restriction, Diabetes Mellitus, Type 2 diet therapy, Diabetes Mellitus, Type 2 surgery, Gastric Bypass, Insulin Resistance physiology, Insulin-Secreting Cells physiology
- Abstract
Marked improvement in glycemic control occurs in patients with type 2 diabetes mellitus shortly after Roux-en-Y gastric bypass surgery (RYGB) and before there is major weight loss. The objective of this study was to determine whether the magnitude of this change is primarily due to caloric restriction or is unique to the surgical procedure. We studied eleven subjects who underwent RYGB and fourteen subjects mean-matched for BMI, HbA1c, and diabetes duration who were admitted to our inpatient research unit and given a very low-calorie diet (VLCD) of 500 kcal/day with a macronutrient content similar to that consumed by patients after RYGB. Frequently sampled intravenous glucose tolerance tests were performed before and after interventions. Both groups lost an equivalent amount of weight over a mean study period of 21 days. Insulin sensitivity, acute insulin secretion after intravenous glucose administration, and β-cell function as determined by disposition index improved to a similar extent in both groups. Likewise, changes in fasting glucose and fructosamine levels were similar. Based on these data, VLCD improves insulin sensitivity and β-cell function just as well as RYGB in the short term.
- Published
- 2013
- Full Text
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34. Randomized double-blind placebo-controlled study of leptin administration after gastric bypass.
- Author
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Korner J, Conroy R, Febres G, McMahon DJ, Conwell I, Karmally W, and Aronne LJ
- Subjects
- Adult, Cross-Over Studies, Double-Blind Method, Female, Humans, Injections, Subcutaneous, Leptin blood, Leptin therapeutic use, Middle Aged, Gastric Bypass, Leptin pharmacology, Obesity, Morbid blood, Obesity, Morbid drug therapy, Obesity, Morbid surgery, Weight Loss drug effects
- Abstract
Objective: Obese individuals have high levels of circulating leptin and are resistant to the weight-reducing effect of leptin administration at physiological doses. Although Roux-en-Y gastric bypass (RYGB) is an effective weight loss procedure, there is a plateau in weight loss and most individuals remain obese. This plateau may be partly due to the decline in leptin resulting in a state of relative leptin insufficiency. The main objective of this study was to determine whether leptin administration to post-RYGB patients would promote further weight reduction., Design and Methods: This was a randomized, double-blind, placebo-controlled cross-over study of 27 women who were at least 18 months post-RYGB and lost on average 30.8% of their presurgical body weight. Subjects received either leptin or placebo via subcutaneous injection twice daily for 16 weeks, then crossed over to receive the alternate treatment for 16 weeks., Results: Weight change after 16 weeks of placebo was not significantly different from that after 16 weeks of leptin. No changes were observed in percent fat mass, resting energy expenditure, thyroid hormones, or cortisol levels., Conclusion: Contrary to our hypothesis, we did not observe a significant effect of leptin treatment on body weight in women with relative hypoleptinemia after RYGB., (Copyright © 2013 The Obesity Society.)
- Published
- 2013
- Full Text
- View/download PDF
35. Patients with nontuberculous mycobacterial lung disease exhibit unique body and immune phenotypes.
- Author
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Kartalija M, Ovrutsky AR, Bryan CL, Pott GB, Fantuzzi G, Thomas J, Strand MJ, Bai X, Ramamoorthy P, Rothman MS, Nagabhushanam V, McDermott M, Levin AR, Frazer-Abel A, Giclas PC, Korner J, Iseman MD, Shapiro L, and Chan ED
- Subjects
- Adipokines blood, Adipose Tissue physiology, Body Mass Index, Case-Control Studies, Cytokines blood, Disease Susceptibility blood, Disease Susceptibility immunology, Female, Funnel Chest complications, Humans, Male, Middle Aged, Mycobacterium Infections, Nontuberculous immunology, Phenotype, Scoliosis complications, Mycobacterium Infections, Nontuberculous etiology
- Abstract
Rationale: Among patients with nontuberculous mycobacterial lung disease is a subset of previously healthy women with a slender body morphotype, often with scoliosis and/or pectus excavatum. We hypothesize that unidentified factors predispose these individuals to pulmonary nontuberculous mycobacterial disease., Objectives: To compare body morphotype, serum adipokine levels, and whole-blood cytokine responses of patients with pulmonary nontuberculous mycobacteria (pNTM) with contemporary control subjects who are well matched demographically., Methods: We enrolled 103 patients with pNTM and 101 uninfected control subjects of similar demographics. Body mass index and body fat were quantified. All patients with pNTM and a subset of control subjects were evaluated for scoliosis and pectus excavatum. Serum leptin and adiponectin were measured. Specific cytokines important to host-defense against mycobacteria were measured in whole blood before and after stimulation., Measurements and Main Results: Patients with pNTM and control subjects were well matched for age, gender, and race. Patients with pNTM had significantly lower body mass index and body fat and were significantly taller than control subjects. Scoliosis and pectus excavatum were significantly more prevalent in patients with pNTM. The normal relationships between the adipokines and body fat were lost in the patients with pNTM, a novel finding. IFN-γ and IL-10 levels were significantly suppressed in stimulated whole blood of patients with pNTM., Conclusions: This is the first study to comprehensively compare body morphotype, adipokines, and cytokine responses between patients with NTM lung disease and demographically matched controls. Our findings suggest a novel, predisposing immunophenotype that should be mechanistically defined.
- Published
- 2013
- Full Text
- View/download PDF
36. Comparison of glucostatic parameters after hypocaloric diet or bariatric surgery and equivalent weight loss.
- Author
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Plum L, Ahmed L, Febres G, Bessler M, Inabnet W, Kunreuther E, McMahon DJ, and Korner J
- Subjects
- Adiponectin blood, Adult, Blood Glucose analysis, C-Peptide metabolism, Diabetes Mellitus, Type 2 surgery, Diet, Reducing, Female, Ghrelin blood, Glucagon-Like Peptide 1 metabolism, Glucose Tolerance Test, Humans, Insulin blood, Insulin metabolism, Insulin Secretion, Laparoscopy methods, Male, Middle Aged, Obesity surgery, Peptide YY metabolism, Caloric Restriction, Gastric Bypass methods, Insulin Resistance, Obesity diet therapy, Weight Loss
- Abstract
Weight-loss independent mechanisms may play an important role in the improvement of glucose homeostasis after Roux-en-Y gastric bypass (RYGB). The objective of this analysis was to determine whether RYGB causes greater improvement in glucostatic parameters as compared with laparoscopic adjustable gastric banding (LAGB) or low calorie diet (LCD) after equivalent weight loss and independent of enteral nutrient passage. Study 1 recruited participants without type 2 diabetes mellitus (T2DM) who underwent LAGB (n = 8) or RYGB (n = 9). Study 2 recruited subjects with T2DM who underwent LCD (n = 7) or RYGB (n = 7). Insulin-supplemented frequently-sampled intravenous glucose tolerance test (fsIVGTT) was performed before and after equivalent weight reduction. MINMOD analysis of insulin sensitivity (Si), acute insulin response to glucose (AIRg) and C-peptide (ACPRg) response to glucose, and insulin secretion normalized to the degree of insulin resistance (disposition index (DI)) were analyzed. Weight loss was comparable in all groups (7.8 ± 0.4%). In Study 1, significant improvement of Si, ACPRg, and DI were observed only after LAGB. In Study 2, Si, ACPRg, and plasma adiponectin increased significantly in the RYGB-DM group but not in LCD. DI improved in both T2DM groups, but the absolute increase was greater after RYGB (258.2 ± 86.6 vs. 55.9 ± 19.9; P < 0.05). Antidiabetic medications were discontinued after RYGB contrasting with 55% reduction in the number of medications after LCD. No intervention affected fasting glucagon-like peptide (GLP)-1, peptide YY (PYY) or ghrelin levels. In conclusion, RYGB produced greater improvement in Si and DI compared with diet at equivalent weight loss in T2DM subjects. Such a beneficial effect was not observed in nondiabetic subjects at this early time-point.
- Published
- 2011
- Full Text
- View/download PDF
37. Implantable gastric stimulator does not prevent the increase in plasma ghrelin levels that occurs with weight loss.
- Author
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Korner J, Nandi A, Wright SM, Waitman J, McMahon DJ, Bessler M, and Aronne LJ
- Subjects
- Adolescent, Adult, Aged, Double-Blind Method, Electrodes, Implanted, Fasting, Female, Glucose Tolerance Test, Humans, Male, Middle Aged, Obesity, Morbid blood, Peptide YY blood, Postprandial Period, Weight Gain, Young Adult, Electric Stimulation, Ghrelin blood, Obesity, Morbid therapy, Weight Loss physiology
- Abstract
Unlabelled: The SHAPE (Screened Health Assessment and Pacer Evaluation) trial was a 24 month randomized multicenter placebo-controlled study to determine the efficacy of an implantable gastric stimulator (IGS) for weight loss. This report is an investigator-initiated sub-study at one site designed to assess whether IGS affects plasma levels of ghrelin and peptide YY (PYY). The device was implanted in all subjects but was activated in the TREATMENT group (n = 7, BMI = 41.5 ± 2.0 kg/m2) and remained inactive in the CONTROL (n = 6, BMI = 39.5 ± 1.7 kg/m2) during the first 12 months. IGS was activated in both groups during months 12-24. Fasting venous blood was drawn at months 0, 12, and 24 and an oral glucose tolerance test (OGTT) was performed at month 12. Although there was no difference in weight loss at 6 months (, Control: -6.6 ± 1.5% vs., Treatment: -6.2 ± 1.4%), at 24 months the CONTROL group exhibited weight gain from baseline (+2.2 ± 1.5%) that was significantly different from the weight loss in the TREATMENT group (-1.9 ± 1.4%; P < 0.05). At 12 months, fasting ghrelin was significantly increased (P < 0.05) in the TREATMENT group (285 ± 35 to 336 ± 35 pg/ml; weight change, -4.9 ± 1.4%), but not in the CONTROL (211 ± 36 to 208 ± 35 pg/ml; weight change, -3.4 ± 1.5%). No significant change was observed in postprandial suppression of plasma ghrelin or in fasting and postprandial PYY levels. In conclusion, IGS does not prevent the increase in fasting plasma ghrelin levels associated with weight loss. Further studies are needed to determine whether changes in technology can improve weight loss and maintenance, perhaps using gut hormones as biomarkers of possible efficacy.
- Published
- 2011
- Full Text
- View/download PDF
38. Prospective study of gut hormone and metabolic changes after adjustable gastric banding and Roux-en-Y gastric bypass.
- Author
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Korner J, Inabnet W, Febres G, Conwell IM, McMahon DJ, Salas R, Taveras C, Schrope B, and Bessler M
- Subjects
- Female, Gastric Bypass, Gastroplasty methods, Humans, Male, Middle Aged, Obesity, Morbid surgery, Postprandial Period, Prospective Studies, Blood Glucose metabolism, Glucagon-Like Peptide 1 metabolism, Insulin Resistance physiology, Obesity, Morbid metabolism, Weight Loss physiology
- Abstract
Objective: The objective of this study was to quantify hormones that regulate energy and glucose homeostasis to establish possible mechanisms for the greater efficacy of Roux-en-Y gastric bypass (RYGB) compared with laparoscopic adjustable gastric banding (LAGB) in achieving weight loss and improved insulin sensitivity., Design: Longitudinal study of patients undergoing LAGB (n=15) and RYGB (n=28) who were studied before surgery and at 2, 12, 26 and 52 weeks afterwards., Measurements: Fasting blood samples were drawn at each visit. Postprandial blood samples were also obtained before surgery and at 26 and 52 weeks. Samples were assayed for peptide YY (PYY), ghrelin, glucagon-like peptide-1 (GLP-1), glucose, insulin, leptin, thyrotropic hormone, free T(4) and free T(3)., Results: At 1 year there was greater weight loss in RYGB compared with LAGB patients (30 vs 15%), but final body mass index was similar (34 vs 33 kg m(-2)). At week 52, area under the curve (AUC) for PYY in RYGB subjects was greater than LAGB (P<0.01). GLP-1 levels at 30 min after meal were threefold greater after RYGB compared with LAGB (P<0.001). Conversely, ghrelin AUC increased after LAGB at week 52 (P<0.05) but tended to decrease after RYGB. Fasting glucose, insulin, and leptin and homeostasis model of assessment (HOMA-IR) decreased in both groups over time but were significantly lower at week 52 after RYGB compared with LAGB. The change in leptin correlated significantly with weight loss in LAGB (r=0.86) and RYGB (r=0.77), however, HOMA-IR correlated significantly with weight loss only in LAGB (r=0.78), and not RYGB (r=0.15). There was a significant decrease in free T(3) (P<0.01) after RYGB., Conclusions: Differences in levels of gut hormones may play a role in promoting greater weight loss and insulin sensitivity after RYGB compared with LAGB, however, weight loss may be limited by decreases in free T(3) and leptin.
- Published
- 2009
- Full Text
- View/download PDF
39. Differential effects of gastric bypass and banding on circulating gut hormone and leptin levels.
- Author
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Korner J, Inabnet W, Conwell IM, Taveras C, Daud A, Olivero-Rivera L, Restuccia NL, and Bessler M
- Subjects
- Adult, Analysis of Variance, Area Under Curve, Female, Ghrelin, Glucose Tolerance Test, Humans, Insulin blood, Middle Aged, Peptide Hormones blood, Postprandial Period, Weight Loss physiology, Gastric Bypass, Gastroplasty, Leptin blood, Obesity, Morbid blood, Obesity, Morbid surgery, Peptide YY blood, Satiety Response physiology
- Abstract
Objective: To quantify plasma concentrations of hormones that regulate energy homeostasis in order to establish possible mechanisms for greater weight loss after Roux-en-Y gastric bypass (RYGBP) compared with gastric banding (BND)., Research Methods and Procedures: Four groups of women were studied: lean (n = 8; mean BMI, 21.6 kg/m2); BND (n = 9; BMI, 35.8; 25% weight loss), RYGBP (n = 9; BMI, 34.2; 36% weight loss), and controls matched for BMI to the surgical groups (n = 11; BMI, 34.4)., Results: Fasting total peptide YY (PYY) and PYY(3-36) immunoreactivity were similar among all groups, but the postprandial response in the RYGBP group was exaggerated, such that 30 minutes after the meal, total and PYY(3-36) levels were 2- to 4-fold greater compared with all other groups. Maximal postprandial suppression of total ghrelin was blunted in the BND group (13%) compared with RYGBP (27%). Postprandial suppression of octanoylated ghrelin was also less in BND (29%) compared with RYGBP (56%). Fasting insulin was lower in RYGBP (6.6 microU/mL) compared with BND (10.0 microU/mL). Compared with lean controls, leptin concentrations were significantly higher in BND but not in RYGBP. There was a greater increase in post-meal satiety in the RYGBP group compared with BND and overweight controls., Discussion: The differences between RYGBP and BND subjects in postprandial concentrations of PYY and ghrelin would be expected to promote increased satiety and earlier meal termination in RYGBP and may aid in greater weight loss. The differences in insulin and leptin concentrations associated with these procedures may also reflect differences in insulin sensitivity and energy partitioning.
- Published
- 2006
- Full Text
- View/download PDF
40. Mennen clamp-on plate fixation of periprosthetic fractures of the humerus after shoulder arthroplasty--a report on 3 patients.
- Author
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Lill H, Hepp P, Rose T, Korner J, and Josten C
- Subjects
- Accidental Falls, Aged, Aged, 80 and over, Arthroplasty, Replacement, Female, Fracture Fixation, Internal methods, Fracture Healing, Humans, Joint Prosthesis, Male, Radiography, Shoulder Fractures diagnostic imaging, Shoulder Fractures etiology, Shoulder Joint surgery, Bone Plates, Fracture Fixation, Internal instrumentation, Shoulder Fractures surgery
- Published
- 2004
- Full Text
- View/download PDF
41. The emerging science of body weight regulation and its impact on obesity treatment.
- Author
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Korner J and Aronne LJ
- Subjects
- Energy Metabolism, Humans, Body Weight, Obesity therapy
- Published
- 2003
- Full Text
- View/download PDF
42. Treatment with cabergoline is associated with weight loss in patients with hyperprolactinemia.
- Author
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Korner J, Lo J, Freda PU, and Wardlaw SL
- Subjects
- Anti-Obesity Agents, Cabergoline, Female, Humans, Male, Ergolines adverse effects, Hyperprolactinemia drug therapy, Weight Loss
- Published
- 2003
- Full Text
- View/download PDF
43. Effects of leptin receptor mutation on Agrp gene expression in fed and fasted lean and obese (LA/N-faf) rats.
- Author
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Korner J, Wardlaw SL, Liu SM, Conwell IM, Leibel RL, and Chua SC Jr
- Subjects
- Agouti-Related Protein, Amino Acid Sequence genetics, Animals, Cloning, Molecular, DNA, Complementary genetics, Eating physiology, Fasting physiology, Hypothalamus, Middle metabolism, Intercellular Signaling Peptides and Proteins, Male, Molecular Sequence Data, Obesity metabolism, Pro-Opiomelanocortin genetics, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Receptors, Leptin, Reference Values, Carrier Proteins genetics, Gene Expression physiology, Mutation physiology, Obesity genetics, Proteins genetics, Receptors, Cell Surface
- Abstract
Agouti-related protein provides an orexigenic signal, probably through interaction with central melanocortin receptors. Expression of Agrp is markedly increased in the hypothalamus of mice deficient in leptin (Lep(ob)/Lep(ob)) or its receptor (Lepr(db)/Lepr(db)), suggesting that leptin mediates signals suppressing Agouti-related protein production. The regulation of Agrp expression in the rat hypothalamus has not been reported. We, therefore, analyzed the expression of Agrp in the medial basal hypothalamus of lean (+/+, +/fa(f)) and obese leptin receptor-deficient (fa(f)/fa(f)) LA/N rats. Using a sensitive solution hybridization/S1 nuclease protection assay, we found no significant difference in Agrp messenger RNA (mRNA) levels (pg/microg total RNA +/- SEM) in obese rats (n = 5), compared with lean controls (n = 5): 0.46 +/- 0.06 vs. 0.47 +/- 0.06 (P = 0.9). Similarly, no difference in Agrp expression was found using in situ hybridization or semiquantitative RT-PCR. In contrast to Agrp, Pomc mRNA levels were significantly suppressed in the obese, compared with the lean, rats (P = 0.001). Thus, the ratio of Pomc to Agrp mRNA is decreased in the obese rats and may be an important modulator of food intake. To assess the physiological regulation of Agrp in rats, we examined the effect of food deprivation in lean Sprague Dawley (SD) rats. There was a 273% increase in medial basal hypothalamus Agrp mRNA in SD rats fasted for 48 h (n = 8), compared with rats fed ad libitum (n = 8): 0.82 +/- 0.23 vs. 0.30 +/- 0.08 (P = 0.0001). Lean LA/N rats (n = 7) fasted for 48 h also showed a 231% increase in Agrp expression, compared with fed lean controls (n = 8): 0.74 +/- 0.11 vs. 0.32 +/- 0.03 (P = 0.002), whereas Pomc expression was decreased by 32% in fasted animals from the same experiment (0.34 +/- 0.05 vs. 0.50 +/- 0.07; P = 0.03). There were no significant differences in Agrp or Pomc mRNA levels between fasted and fed obese LA/N-fa(f) rats. These results suggest that, in the rat, the Agrp response to fasting may involve leptin-mediated phenomena, but factors in addition to leptin must also be involved in the regulation of Agrp gene expression.
- Published
- 2000
- Full Text
- View/download PDF
44. Prohormone processing in Xenopus oocytes: characterization of cleavage signals and cleavage enzymes.
- Author
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Korner J, Chun J, O'Bryan L, and Axel R
- Subjects
- Amino Acid Sequence, Animals, Aplysia, Base Sequence, Cloning, Molecular, Furin, Humans, Mating Factor, Microinjections, Molecular Sequence Data, Mutagenesis, Site-Directed, Oligodeoxyribonucleotides, Pheromones genetics, Protein-Tyrosine Kinases genetics, RNA genetics, Sequence Homology, Nucleic Acid, Xenopus laevis, Endopeptidases metabolism, Invertebrate Hormones genetics, Oocytes physiology, Peptides genetics, Protein Precursors genetics, Protein Processing, Post-Translational, Protein Sorting Signals metabolism, Subtilisins genetics
- Abstract
In this study, we characterize the sequences required for the cleavage of prohormones in Xenopus oocytes. We demonstrate that the yeast alpha-factor and the Aplysia egg-laying hormone (ELH) precursors are not cleaved in oocytes following simple pairs of basic residues, such as Lys-Arg, but that the ELH precursor is cleaved following the consensus sequence Arg-Xaa-(Lys/Arg)-Arg. This motif is conserved among precursors that are cleaved in virtually all mammalian cell types. Mutations that generate this sequence in the alpha-factor prohormone also result in efficient processing within oocytes. Cleavage at this consensus sequence may be due to the action of the Xenopus homologues of mammalian furin.
- Published
- 1991
- Full Text
- View/download PDF
45. Isolation and functional expression of a mammalian prohormone processing enzyme, murine prohormone convertase 1.
- Author
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Korner J, Chun J, Harter D, and Axel R
- Subjects
- Amino Acid Sequence, Animals, Cell Line, Cloning, Molecular, Gene Expression, Glycosylation, Mice, Molecular Sequence Data, Oocytes enzymology, Oocytes physiology, Peptide Mapping, Pro-Opiomelanocortin genetics, Pro-Opiomelanocortin metabolism, Proprotein Convertases, Proto-Oncogene Proteins genetics, Proto-Oncogene Proteins isolation & purification, Proto-Oncogene Proteins metabolism, Proto-Oncogene Proteins c-fes, Sequence Homology, Nucleic Acid, Serine Endopeptidases isolation & purification, Serine Endopeptidases metabolism, Xenopus laevis, Proprotein Convertase 1, Protein Processing, Post-Translational, Protein-Tyrosine Kinases, Serine Endopeptidases genetics
- Abstract
We have combined gene cloning with an assay for prohormone biosynthesis and processing in Xenopus oocytes to identify the genes that encode mammalian prohormone processing enzymes. The coinjection of RNA encoding murine prohormone convertase 1 (mPC1), a mammalian endoprotease, along with proopiomelanocortin RNA into an oocyte results in the appropriate cleavage after paired basic residues in the proopiomelanocortin polyprotein necessary to generate corticotropin. The ability of mPC1 to generate corticotropin, along with the observation that mPC1 is specifically expressed in endocrine and neuronal cells, suggests that the mPC1 gene encodes the endopeptidase responsible for the pathway of proopiomelanocortin cleavage observed in the anterior pituitary.
- Published
- 1991
- Full Text
- View/download PDF
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