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1.
Front Nutr ; 11: 1385510, 2024.
Article in English | MEDLINE | ID: mdl-38807643

ABSTRACT

Background: Among commonly performed bariatric surgeries, biliopancreatic diversion with duodenal switch (BPD-DS) provides greater weight loss than Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG), with sustained metabolic improvements. However, the risk of long-term nutritional deficiencies due to the hypoabsorptive component of BPD-DS hinders its widespread use. Objective: The aim of the study was to examine nutritional status over 2 years after BPD-DS, RYGB or SG. Methods: Patients were recruited in the REMISSION trial (NCT02390973), a single-center, prospective study. Out of 215 patients, 73, 48 and 94, respectively, underwent BPD-DS, RYGB or SG. Weight loss, micronutrient serum levels (including iron, calcium, parathormone, vitamins A, B12 and D), and nutritional supplementation were assessed over 2 years. Patients were supplemented according to the type of surgery and individual micronutrient level evolution. Results: At baseline, BPD-DS patients were younger than SG patients (p = 0.0051) and RYGB patients had lower body mass index (p < 0.001). Groups had similar micronutrient levels before surgery, with vitamin D insufficiency as the most prevalent nutritional problem (SG: 38.3%, RYGB: 39.9%, BPD-DS: 54.8%, p = 0.08). BPD-DS patients showed lower levels of iron, calcium and vitamin A than SG patients at 24 months. Groups had similar levels of vitamin D at 24 months. Prevalence of vitamin D, calcium, iron, vitamin A and vitamin B12 deficiency was similar among groups at 24 months. Rates of vitamin D insufficiency and iron deficiency were lower at 24 months than at baseline. Micronutrient intake was consistent with recommendations in groups post-surgery, but most BPD-DS patients took vitamin A and vitamin D supplement doses above initial recommendations. Conclusion: With appropriate medical and nutritional management, all surgeries led to similar rates of vitamin D, calcium, iron, vitamin A and vitamin B12 deficiencies at 24 months. However, initial vitamin A and vitamin D supplementation recommendations for BPD-DS patients should be revised upwards.

2.
Rev Med Suisse ; 19(824): 817-819, 2023 Apr 26.
Article in French | MEDLINE | ID: mdl-37133943

ABSTRACT

The tauopathies are one of the families of proteinopathies causing neurodegenerative diseases. They are characterized by a combination of cognitive and motor disorders. In this article, we summarize the clinical features of progressive supranuclear palsy and cortico-basal degeneration, focusing on their cognitive-behavioral impairment profiles, which in some cases allow them to be differentiated from other neurodegenerative entities. Finally, we propose tools for therapeutic management.


Les tauopathies sont une des familles de protéinopathies engendrant des maladies neurodégénératives. Elles se caractérisent par l'association de troubles cognitifs et moteurs. Dans cet article, nous résumons les caractéristiques cliniques de la paralysie supranucléaire progressive et de la dégénérescence cortico-basale, en nous attardant sur leurs profils d'atteinte cognitivo-comportementale, qui permettent, dans certains cas, de les différencier d'autres entités neurodégénératives. Enfin, nous proposons des outils de prise en charge thérapeutique.


Subject(s)
Cognitive Dysfunction , Neurodegenerative Diseases , Supranuclear Palsy, Progressive , Tauopathies , Humans , Tauopathies/therapy , Supranuclear Palsy, Progressive/diagnosis , Supranuclear Palsy, Progressive/therapy , Neurodegenerative Diseases/therapy , Cognition , tau Proteins
3.
Sustain Sci ; 17(4): 1149-1158, 2022.
Article in English | MEDLINE | ID: mdl-35872971

ABSTRACT

The debates on the sustainability of development have a long history. Although the Brundtland Report popularized "sustainable development", this slippery concept sidelined previous critiques of development and has been compatible with a wide range of conflicting agendas. A notable example of this contradiction is the uncritical promotion of capitalist growth in the pursuit of social justice and ecosystem health by the sustainable development goals. In contrast to this reliance on the "one world" of Euroamerican market economies, this special feature presents 12 case studies of "alternatives to sustainable development". These case studies question the anthropocentric universalism of the development project and enact radically different relational ontologies, often gathered under the conceptual umbrella of the "pluriverse". They focus on territorial, community, and network initiatives that intend to move methodologically beyond discourse analysis with a situated and empirical analysis of how pluriversal practices might flourish as well as generate tensions. We identify three frictions with capitalist modernity emerging from these contributions: (1) how alternatives to sustainable development relate to state institutions, (2) how they engage with the distribution of surplus, and (3) how they unsettle scientific epistemologies, at times regenerating past resources-and at other times radical futures. With this special feature, we hope to re-politicize the debates on the science and practice of sustainability, and weave the contributions of anticolonial and indigenous science studies into neo-Marxist and post-development critiques.

4.
Metabolites ; 12(5)2022 May 13.
Article in English | MEDLINE | ID: mdl-35629944

ABSTRACT

Non-alcoholic fatty liver disease (NAFLD) is a complex disease associated with premature mortality. Its diagnosis is challenging, and the identification of biomarkers causally influenced by NAFLD may be clinically useful. We aimed at identifying blood metabolites causally impacted by NAFLD using two-sample Mendelian randomization (MR) with validation in a population-based biobank. Our instrument for genetically predicted NAFLD included all independent genetic variants from a recent genome-wide association study. The outcomes included 123 blood metabolites from 24,925 individuals. After correction for multiple testing, a positive effect of NAFLD on plasma tyrosine levels but not on other metabolites was identified. This association was consistent across MR methods and was robust to outliers and pleiotropy. In observational analyses performed in the Estonian Biobank (10,809 individuals including 359 patients with NAFLD), after multivariable adjustment, tyrosine levels were positively associated with the presence of NAFLD (odds ratio per 1 SD increment = 1.23 [95% confidence interval = 1.12-1.36], p = 2.19 × 10-5). In a small proof-of-concept study on bariatric surgery patients, blood tyrosine levels were higher in patients with NAFLD than without. This study revealed a potentially causal effect of NAFLD on blood tyrosine levels, suggesting it may represent a new biomarker of NAFLD.

5.
Nanoscale ; 14(13): 4965-4976, 2022 Mar 31.
Article in English | MEDLINE | ID: mdl-35297939

ABSTRACT

The piezoelectric nanowires (NWs) are considered as promising nanomaterials to develop high-efficient piezoelectric generators. Establishing the relationship between their characteristics and their piezoelectric conversion properties is now essential to further improve the devices. However, due to their nanoscale dimensions, the NWs are characterized by new properties that are challenging to investigate. Here, we use an advanced nano-characterization tool derived from AFM to quantify the piezo-conversion properties of NWs axially compressed with a well-controlled applied force. This unique technique allows to establish the direct relation between the output signal generation and the NW stiffness and to quantify the electromechanical coupling coefficient of GaN NWs, which can reach up to 43.4%. We highlight that this coefficient is affected by the formation of the Schottky nano-contact harvesting the piezo-generated energy, and is extremely sensitive to the surface charge effects, strongly pronounced in sub-100 nm wide GaN NWs. These results constitute a new building block in the improvement of NW-based nanogenerator devices.

7.
Can J Cardiol ; 37(2): 251-259, 2021 02.
Article in English | MEDLINE | ID: mdl-32738206

ABSTRACT

BACKGROUND: Severely obese patients have decreased cardiorespiratory fitness (CRF) and poor functional capacity. Bariatric surgery-induced weight loss improves CRF, but the determinants of this improvement are not well known. We aimed to assess the determinants of CRF before and after bariatric surgery and the impact of an exercise training program on CRF after bariatric surgery. METHODS: Fifty-eight severely obese patients (46.1 ± 6.1 kg/m2, 78% women) were randomly assigned to either an exercise group (n = 39) or usual care (n = 19). Exercise training was conducted from the 3rd to the 6th months after surgery. Anthropometric measurements, abdominal and mid-thigh computed tomographic scans, resting echocardiography, and maximal cardiopulmonary exercise testing was performed before bariatric surgery and 3 and 6 months after surgery. RESULTS: Weight, fat mass, and fat-free mass were reduced significantly at 3 and 6 months, without any additive impact of exercise training in the exercise group. From 3 to 6 months, peak aerobic power (V̇O2peak) increased significantly (P < 0.0001) in both groups but more importantly in the exercise group (exercise group: from 18.6 ± 4.2 to 23.2 ± 5.7 mL/kg/min; control group: from 17.4 ± 2.3 to 19.7 ± 2.4 mL/kg/min; P value, group × time = 0.01). In the exercise group, determinants of absolute V̇O2peak (L/min) were peak exercise ventilation, oxygen pulse, and heart rate reserve (r2 = 0.92; P < 0.0001), whereas determinants of V̇O2peak indexed to body mass (mL/kg/min) were peak exercise ventilation and early-to-late filling velocity ratio (r2 = 0.70; P < 0.0001). CONCLUSIONS: A 12-week supervised training program has an additive benefit on cardiorespiratory fitness for patients who undergo bariatric surgery.


Subject(s)
Bariatric Surgery/rehabilitation , Exercise Therapy/methods , Obesity , Preoperative Exercise/physiology , Adult , Anthropometry/methods , Bariatric Surgery/methods , Cardiorespiratory Fitness/physiology , Echocardiography/methods , Exercise Test/methods , Female , Humans , Male , Metabolic Equivalent/physiology , Obesity/diagnosis , Obesity/physiopathology , Obesity/surgery , Outcome Assessment, Health Care/methods
8.
Nanotechnology ; 32(8): 085705, 2021 Feb 19.
Article in English | MEDLINE | ID: mdl-33171444

ABSTRACT

We analyse the electrical and optical properties of single GaN nanowire p-n junctions grown by plasma-assisted molecular-beam epitaxy using magnesium and silicon as doping sources. Different junction architectures having either a n-base or a p-base structure are compared using optical and electrical analyses. Electron-beam induced current (EBIC) microscopy of the nanowires shows that in the case of a n-base p-n junction the parasitic radial growth enhanced by the magnesium (Mg) doping leads to a mixed axial-radial behaviour with strong wire-to-wire fluctuations of the junction position and shape. By reverting the doping order p-base p-n junctions with a purely axial well-defined structure and a low wire-to-wire dispersion are achieved. The good optical quality of the top n nanowire segment grown on a p-doped stem is preserved. A hole concentration in the p-doped segment exceeding 1018 cm-3 was extracted from EBIC mapping and photoluminescence analyses. This high concentration is reached without degrading the nanowire morphology.

9.
Nanomaterials (Basel) ; 10(11)2020 Nov 16.
Article in English | MEDLINE | ID: mdl-33207755

ABSTRACT

We analyze the thermal behavior of a flexible nanowire (NW) light-emitting diode (LED) operated under different injection conditions. The LED is based on metal-organic vapor-phase deposition (MOCVD)-grown self-assembled InGaN/GaN NWs in a polydimethylsiloxane (PDMS) matrix. Despite the poor thermal conductivity of the polymer, active nitride NWs effectively dissipate heat to the substrate. Therefore, the flexible LED mounted on a copper heat sink can operate under high injection without significant overheating, while the device mounted on a plastic holder showed a 25% higher temperature for the same injected current. The efficiency of the heat dissipation by nitride NWs was further confirmed with finite-element modeling of the temperature distribution in a NW/polymer composite membrane.

10.
Obes Surg ; 30(12): 5047-5058, 2020 12.
Article in English | MEDLINE | ID: mdl-32940866

ABSTRACT

PURPOSE: The effectiveness of the standard biliopancreatic diversion with duodenal switch (BPD/DS) in terms of weight loss has been demonstrated. Increasing the strict alimentary limb length while maintaining the length of the common channel could lead to similar weight loss while reducing side effects. MATERIALS AND METHODS: The objective was to evaluate the effect of increasing the strict alimentary limb length on weight loss, comorbidities, nutritional deficiencies, and quality of life 2 years after surgery, compared with standard BPD/DS. An exploratory randomized, double-blind study evaluated the results of LADS at 2 years in comparison with the standard BPD/DS. Common channel was kept at 100 cm in both groups while alimentary limb was created at 100 cm from Treitz angle in the LADS group and at 150 cm total in the BPD/DS group. RESULTS: Twenty patients were recruited from May 2013 to June 2015. Mean percentage of excess weight loss was statistically significantly lower in the LADS group at 24 months (81.6 ± 6.6% in the LADS group and 97.1 ± 11.1% in the BPD/DS group (p = 0.001). No significant difference regarding the rate of remission of comorbidities was noted. Mean calcium, vitamin D, hemoglobin, zinc, and copper levels were statistically lower in the BPD/DS group. Quality of life was significantly improved in both groups, with no statistically significant difference between the two groups. CONCLUSIONS: At 24 months, weight loss was lower in the LADS group. However, no difference was observed in the improvement in quality of life. LADS technique was discontinued following this study. TRIAL REGISTRATION: ClinicalTrial.gov Ref. NCT03097926.


Subject(s)
Biliopancreatic Diversion , Obesity, Morbid , Anastomosis, Surgical , Duodenum/surgery , Humans , Obesity, Morbid/surgery , Quality of Life
11.
Surg Obes Relat Dis ; 16(11): 1701-1712, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32800734

ABSTRACT

BACKGROUND: Biliopancreatic diversion with duodenal switch (BPD-DS) confers the highest rate of type 2 diabetes (T2D) remission compared with other bariatric procedures. Previous studies suggest that type of antidiabetic therapy used before surgery and duration of disease influence postsurgical glycemic outcomes. Short-term, progressive improvement in insulin sensitivity and beta-cell function after metabolic surgery in patients with noninsulin-treated T2D has been demonstrated. Whether patients with more advanced disease can achieve sustained remission remains unclear. OBJECTIVE: The aim of this study was to assess long-term glycemic outcomes in insulin-treated patients with T2D after BPD-DS and identify predictors of sustained diabetes remission or relapse. SETTING: University-affiliated tertiary care center. METHODS: Data from 141 patients with insulin-treated T2D who underwent BPD-DS between 1994 and 2006 with 10 years of follow-up data were collected from a prospective electronic database. RESULTS: Follow-up was available in 132 patients (91%). At 10 years after metabolic surgery, 90 patients (68.1%) had a complete remission of diabetes, 3 (2.3%) had a partial remission, 21 (15.9%) had an improvement, and 3 (2.3%) were unchanged in their diabetes status. Fourteen patients died during the 10-year follow-up period. Relapse after an initial period of remission occurred in 15 (11.4%) patients. Insulin discontinuation was achieved in 97%. Duration of diabetes was an independent predictor of nonremission at 10 years. CONCLUSIONS: The BPD-DS maintains remission at 10 years postoperatively in patients with more advanced diabetes. Long-term benefits of the BPD-DS on weight loss and glycemic control should be considered when offering metabolic surgery to patients with insulin-treated T2D.


Subject(s)
Biliopancreatic Diversion , Diabetes Mellitus, Type 2 , Obesity, Morbid , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/surgery , Humans , Insulin/therapeutic use , Obesity, Morbid/surgery , Prospective Studies , Weight Loss
12.
Nanotechnology ; 31(43): 435408, 2020 Oct 23.
Article in English | MEDLINE | ID: mdl-32650318

ABSTRACT

Optoelectronic devices based on high aspect ratio nanowires bring new challenges for transparent electrodes, which can be well addressed by using hybrid structures. Here we demonstrate that a composite contact to radial junction nanowire solar cells made of a thin indium-tin oxide (ITO) layer and silver nanowires greatly improves the collection of charge carriers as compared to a single thick ITO layer by reducing the series resistance losses while improving the transparency. The optimization is performed on p-i-n solar cells comprising of dense non-vertical nanowires with a p-doped c-Si core and an ultra-thin a-Si:H absorption layer grown by plasma-enhanced chemical vapor deposition on glass substrates. The optimal hybrid contact developed in this work is demonstrated to increase the solar cell conversion efficiency from 4.3% to 6.6%.

13.
Obes Surg ; 30(10): 3714-3720, 2020 10.
Article in English | MEDLINE | ID: mdl-32666413

ABSTRACT

BACKGROUND: Elevated lipoprotein(a) (Lp(a)) level is an independent risk factor for cardiovascular diseases. Lifestyle intervention studies targeting weight loss revealed little to no significant changes in Lp(a) levels. The impact of interventions that induce substantial weight loss, such as bariatric surgery, on Lp(a) levels is currently unclear. OBJECTIVE: To determine the acute and long-term impact of bariatric surgery on Lp(a) levels in patients with severe obesity. METHODS: Sixty-nine patients with severe obesity underwent biliopancreatic diversion with duodenal switch (BPD-DS) surgery. The lipid profile was evaluated and Lp(a) levels were measured before surgery and at 6 and 12 months after BPD-DS surgery. RESULTS: Median Lp(a) levels at baseline were 11.1 (4.1-41.6) nmol/L. Six months and 12 months after the BDP-DS surgery, we observed an improvement of lipid profile. At 6 months, we observed a 13% decrease in Lp(a) levels (9.7 (2.9-25.6) nmol/L, p < 0.0001) but this decrease was not sustained at 12 months (11.1 (3.9-32.8) nmol/L, p = 0.8). When the patients were separated into tertiles according to Lp(a) levels at baseline, we observed that the Lp(a) reduction at 12 months after BPD-DS surgery remained significant but modest in patients of the top Lp(a) tertile. CONCLUSION: Our results suggest that BPD-DS surgery modestly reduces Lp(a) levels in the short term (6 months) in patients with severe obesity but this improvement is sustained over time only in patients with higher Lp(a) levels.


Subject(s)
Bariatric Surgery , Biliopancreatic Diversion , Obesity, Morbid , Duodenum , Humans , Lipoprotein(a) , Obesity, Morbid/surgery , Plasma
14.
Obes Surg ; 30(6): 2085-2092, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32080798

ABSTRACT

OBJECTIVES: The clinical benefit of bariatric surgery in patients with severe obesity and established coronary artery disease (CAD) is unclear. We aimed to compare the cardiovascular outcomes of severely obese CAD patients with and without bariatric surgery. METHODS: Patients with a history of myocardial revascularization documented prior to bariatric surgery were identified from a dedicated database with prospectively collected outcomes. These patients were matched 1 to 1 with CAD patients who had prior revascularization but who did not undergo bariatric surgery. The primary outcomes were death (cardiac and non-cardiac) and major adverse cardio-cerebral events (MACCE), including death, myocardial infarction (MI), stroke, and repeat myocardial revascularization throughout follow-up. RESULTS: After propensity score matching, 116 bariatric patients were matched with 116 control patients. Ninety-eight had a history of coronary artery bypass surgery and 134 had a previous percutaneous coronary intervention. After a median follow-up of 8.9 (6.3-14.2) years, MACCE was significantly lower in the bariatric group (HR 0.65; 95% CI 0.42-1.00; P = 0.049) driven by a significant reduction in non-cardiac mortality (HR 0.49; 95% CI 0.23-1.00; P = 0.049). There was no significant difference in the rates of all-cause death (HR 0.58; 95% CI 0.33-1.01; P = 0.056), cardiovascular death (HR 0.77; 95% CI 0.31-1.85; P = 0.55), MI (HR 1.09; 95% CI 0.47-2.58; P = 0.85), stroke (HR 1.47; 95% CI 0.24-11.2; P = 0.67), and repeat myocardial revascularization (HR 0.56; 95% CI 0.27-1.13; P = 0.11). CONCLUSION: Although bariatric surgery in obese CAD patients may reduce the composite MACCE endpoint during long-term follow-up, this effect seems unrelated to cardiovascular outcomes.


Subject(s)
Bariatric Surgery , Coronary Artery Disease , Obesity, Morbid , Coronary Artery Bypass , Coronary Artery Disease/surgery , Humans , Obesity/complications , Obesity/surgery , Obesity, Morbid/surgery , Treatment Outcome
15.
Nanotechnology ; 31(14): 145708, 2020 Apr 03.
Article in English | MEDLINE | ID: mdl-31846937

ABSTRACT

Axial p-n and p-i-n junctions in GaAs0.7P0.3 nanowires are demonstrated and analyzed using electron beam induced current microscopy. Organized self-catalyzed nanowire arrays are grown by molecular beam epitaxy on nanopatterned Si substrates. The nanowires are doped using Be and Si impurities to obtain p- and n-type conductivity, respectively. A method to determine the doping type by analyzing the induced current in the vicinity of a Schottky contact is proposed. It is demonstrated that for the applied growth conditions using Ga as a catalyst, Si doping induces an n-type conductivity contrary to the GaAs self-catalyzed nanowire case, where Si was reported to yield a p-type doping. Active axial nanowire p-n junctions having a homogeneous composition along the axis are synthesized and the carrier concentration and minority carrier diffusion lengths are measured. To the best of our knowledge, this is the first report of axial p-n junctions in self-catalyzed GaAsP nanowires.

16.
Am J Cardiol ; 125(1): 40-47, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31694775

ABSTRACT

There is little data regarding the risks and benefits of bariatric surgery in patients with coronary artery disease (CAD). We aimed to assess the short- and long-term cardiovascular outcomes of patients with CAD undergoing bariatric surgery. Patients with a history of CAD were identified from a dedicated database with prospectively collected outcomes, comprising all 6795 patients who underwent bariatric surgery between January 1992 and October 2017. Patients were matched with patients who did not have CAD before the bariatric surgery procedure. The primary endpoints were mortality (cardiac and noncardiac) and major adverse cardiocerebral events (MACCE), including all-cause death, myocardial infarction, stroke, and myocardial revascularization at 30 days after bariatric surgery and throughout follow-up. After propensity score matching, 249 patients with chronic CAD were matched with 249 patients without CAD. Throughout follow-up (7.4 years; interquartile range 4.1 to 11.5, maximum 22 years), mortality (mainly cardiac mortality) remained significantly higher in the CAD compared with the non-CAD group (18% vs 10%, hazard ratio [HR] 1.70, 95% confidence interval [CI]: 1.03 to 2.79, p = 0.037). At 30 days, MACCE rate was significantly higher in the CAD compared with the non-CAD group (3.6% vs 0.4%, p = 0.011), essentially driven by non-ST elevation myocardial infarctions. After 30 days, MACCE rates remained significantly higher in the CAD group (30% vs 14%, HR 2.18, 95% CI: 1.45-3.28, p = 0.0002). In conclusion, patients with severe obesity and CAD referred to bariatric surgery were at a higher risk of early and late MACCE compared with non-CAD severely obese patients. Further study is required to define how this cardiovascular risk compares with nonoperated patients.


Subject(s)
Bariatric Surgery , Coronary Artery Disease/complications , Obesity/surgery , Postoperative Complications/epidemiology , Propensity Score , Risk Assessment/methods , Adult , Cause of Death/trends , Chronic Disease , Female , Follow-Up Studies , Humans , Incidence , Male , Middle Aged , Obesity/complications , Prognosis , Quebec/epidemiology , Retrospective Studies , Risk Factors , Survival Rate/trends , Time Factors
17.
Clin Epigenetics ; 11(1): 172, 2019 12 02.
Article in English | MEDLINE | ID: mdl-31791395

ABSTRACT

BACKGROUND: There is solid evidence that obesity induces the acceleration of liver epigenetic aging. However, unlike easily accessible blood or subcutaneous adipose tissue, little is known about the impact of obesity on epigenetic aging of metabolically active visceral adipose tissue (VAT). Herein, we aimed to test whether obesity accelerates VAT epigenetic aging in subjects with severe obesity. RESULTS: A significant and positive correlation between chronological age and epigenetic age, estimated with a reduced version of the Horvath's epigenetic clock, was found in both blood (r = 0.78, p = 9.4 × 10-12) and VAT (r = 0.80, p = 1.1 × 10-12). Epigenetic age acceleration, defined as the residual resulting from regressing epigenetic age on chronological age, was significantly correlated with body mass index (BMI) in VAT (r = 0.29, p = 0.037). Multivariate linear regression analysis showed that, after adjusting for chronological age, sex and metabolic syndrome status, BMI remained significantly associated with epigenetic age acceleration in VAT (beta = 0.15, p = 0.035), equivalent to 2.3 years for each 10 BMI units. Binomial logistic regression showed that BMI-adjusted epigenetic age acceleration in VAT was significantly associated with a higher loss of excess body weight following biliopancreatic diversion with duodenal switch surgery (odds ratio = 1.21; 95% CI = 1.04-1.48; p = 0.03). CONCLUSIONS: Epigenetic age acceleration increases with BMI in VAT, but not in blood, as previously reported in liver. These results suggest that obesity is associated with epigenetic age acceleration of metabolically active tissues. Further studies that deepen the physiological relevance of VAT epigenetic aging will help to better understand the onset of metabolic syndrome and weight loss dynamics following bariatric surgery.


Subject(s)
DNA Methylation , Intra-Abdominal Fat/chemistry , Obesity/genetics , Adult , Aged , Aged, 80 and over , Biliopancreatic Diversion , Body Mass Index , Epigenesis, Genetic , Female , Humans , Logistic Models , Male , Middle Aged , Obesity/surgery , Young Adult
18.
Physiol Rep ; 7(5): e14004, 2019 03.
Article in English | MEDLINE | ID: mdl-30821134

ABSTRACT

Autotaxin (ATX), an adipose tissue-derived lysophospholipase, has been involved in the pathophysiology of cardiometabolic diseases. The impact of bariatric surgery on circulating ATX levels is unknown. We examined the short- (24 h, 5 days) and longer-term (6 and 12 months) impact of bariatric surgery; as well as the short-term effect of caloric restriction (CR) on plasma ATX levels in patients with severe obesity. We measured ATX levels in 69 men and women (mean age: 41 ± 11 years, body mass index: 49.8 ± 7.1 kg/m2 ), before and after biliopancreatic diversion with duodenal switch surgery (BPD-DS) as well as in a control group (patients with severe obesity without surgery; n = 34). We also measured ATX levels in seven patients with severe obesity and type 2 diabetes who underwent a 3-day CR protocol before their BPD-DS. At baseline, ATX levels were positively associated with body mass index, fat mass, insulin resistance (HOMA-IR) as well as insulin and leptin levels and negatively with fat-free mass. ATX concentrations decreased 26.2% at 24 h after BPD-DS (342.9 ± 152.3 pg/mL to 253.2 ± 68.9 pg/mL, P < 0.0001) and by 16.4% at 12 months after BPD-DS (342.9 ± 152.3 pg/mL to 286.8 ± 182.6 pg/mL, P = 0.04). ATX concentrations were unchanged during follow-up in the control group (P = 0.4), and not influenced by short-term CR. In patients with severe obesity, bariatric surgery induced a rapid and sustained decrease in plasma ATX levels. Acute changes in ATX may not be explained by bariatric surgery-induced CR.


Subject(s)
Bariatric Surgery , Obesity/surgery , Phosphoric Diester Hydrolases/blood , Adiposity , Adult , Bariatric Surgery/adverse effects , Biomarkers/blood , Body Mass Index , Caloric Restriction , Case-Control Studies , Down-Regulation , Female , Humans , Male , Middle Aged , Obesity/blood , Obesity/diagnosis , Obesity/physiopathology , Severity of Illness Index , Time Factors , Treatment Outcome , Weight Loss
19.
Nanotechnology ; 30(21): 214006, 2019 May 24.
Article in English | MEDLINE | ID: mdl-30736025

ABSTRACT

In this work, nanoscale electrical and optical properties of n-GaN nanowires (NWs) containing GaN/AlN multiple quantum discs (MQDs) grown by molecular beam epitaxy are investigated by means of single wire I(V) measurements, electron beam induced current microscopy (EBIC) and cathodoluminescence (CL) analysis. A strong impact of non-intentional AlN and GaN shells on the electrical resistance of individual NWs is put in evidence. The EBIC mappings reveal the presence of two regions with internal electric fields oriented in opposite directions: one in the MQDs region and the other in the adjacent bottom GaN segment. These fields are found to co-exist under zero bias, while under an external bias either one or the other dominates the current collection. In this way EBIC maps allow us to locate the current generation within the wire under different bias conditions and to give the first direct evidence of carrier collection from AlN/GaN MQDs. The NWs have been further investigated by photoluminescence and CL analyses at low temperature. CL mappings show that the near band edge emission of GaN from the bottom part of the NW is blue-shifted due to the presence of the radial shell. In addition, it is observed that CL intensity drops in the central part of the NWs. Comparing the CL and EBIC maps, this decrease of the luminescence intensity is attributed to an efficient charge splitting effect due to the electric fields in the MQDs region and in the GaN base.

20.
Article in English | MEDLINE | ID: mdl-30661603

ABSTRACT

IL-1ß stimulates expression of prostaglandin (PG)-synthesizing enzymes cyclooxygenase (COX)-2 and aldo-keto reductase (AKR)1B1 in human preadipocytes. We aimed to examine the impact of IL-1ß, COX-2 and AKR1B1 on markers of human visceral and subcutaneous adipose tissue function, and to assess whether PG synthesis by these enzymes mediates IL-1ß effects. Omental and subcutaneous fat samples were obtained from bariatric surgery patients. PG release and expression of inflammatory and adipogenic markers were assessed in explants treated with COX-2 inhibitor NS-398 or AKR1B1 inhibitor Statil, with or without IL-1ß. Preadipocyte differentiation experiments were also performed. IL-1ß decreased expression of PPARγ in both fat depots compared to control and increased expression of NF-κB1, IL-6, CCL-5, ICAM-1 and VEGFA, especially in visceral fat for IL-6, CCL-5 and VEGFA. Adding Statil or NS-398 to IL-1ß blunted PGF2α and PGE2 release, but did not alter IL-1ß effects on adipose tissue function markers. IL-1ß down-regulated adipocyte differentiation whereas NS-398 alone increased this process. However, NS-398 did not prevent IL-1ß inhibition of adipogenesis. We conclude that IL-1ß induces a pro-inflammatory response in human adipose tissues, particularly in visceral fat, and acts independently of concomitant PG release. IL-1ß and COX-2 appear to be critical determinants of adipose tissue pathophysiologic remodeling in obesity.


Subject(s)
Aldehyde Reductase/metabolism , Cyclooxygenase 2/metabolism , Dinoprost/biosynthesis , Dinoprostone/biosynthesis , Interleukin-1beta/metabolism , Intra-Abdominal Fat/metabolism , Omentum/metabolism , Subcutaneous Fat, Abdominal/metabolism , Adipocytes/metabolism , Adipogenesis/drug effects , Aldehyde Reductase/antagonists & inhibitors , Cell Differentiation/drug effects , Cyclooxygenase 2 Inhibitors/pharmacology , Cytokines/genetics , Cytokines/metabolism , Female , Humans , Inflammation/metabolism , Male , Middle Aged , Nitrobenzenes/pharmacology , Obesity/metabolism , Obesity/surgery , PPAR gamma/genetics , PPAR gamma/metabolism , Phthalazines/pharmacology , Sulfonamides/pharmacology
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