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1.
JAMA Surg ; 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38748431

RESUMEN

Importance: Obesity and insulin are risk factors for breast cancer, and retrospective studies suggest bariatric surgery reduces breast cancer risk in women. However, long-term prospective data on breast cancer risk after bariatric surgery and the role of baseline insulin levels are lacking. Objective: To examine if bariatric surgery is associated with breast cancer incidence in women and if treatment benefit is modified by baseline insulin levels. Design, Setting, and Participants: The Swedish Obese Subjects (SOS) study was a nonrandomized intervention trial designed to investigate the long-term effects of bariatric surgery on obesity-related mortality and morbidity. Study recruitment took place between 1987 and 2001, and median (IQR) follow-up time was 23.9 years (20.1-27.1) years. The study was conducted at 25 public surgical departments and 480 primary health care centers in Sweden and included 2867 women aged 37 to 60 years and with body mass index 38 or greater (calculated as weight in kilograms divided by height in meters squared). Intervention: In the surgery group (n = 1420), 260 women underwent gastric banding, 970 vertical banded gastroplasty, and 190 gastric bypass. The remaining contemporaneously matched control individuals (n = 1447) received usual obesity care. Main Outcome and Measures: Breast cancer, the main outcome of this secondary report, was not a predefined outcome in the SOS study. Breast cancer events were identified in the Swedish National Cancer Registry. Results: The study population comprised 2867 women with a mean (SD) age of 48.0 (6.2) years. During follow-up, there were 154 breast cancer events, 66 in the surgery group and 88 in the usual care group, and a decreased risk of breast cancer was observed in the bariatric surgery group (hazard ratio [HR], 0.68; 95% CI, 0.49-0.94; P = .019; adjusted HR, 0.72; 95% CI, 0.52-1.01; P = .06). The surgical treatment benefit on breast cancer risk was greater in women with baseline insulin levels above the median 15.8 µIU/L (HR, 0.48; 95% CI, 0.31-0.74; P = .001; adjusted HR, 0.55; 95% CI, 0.35-0.86; P = .008) compared to those below (HR, 0.95; 95% CI, 0.59-1.53; P = .84; adjusted HR, 1.01; 95% CI, 0.61-1.66; P = .97; interaction P = .02). Conclusions and Relevance: This prospective clinical trial indicated a reduced risk of breast cancer after bariatric surgery in women with obesity. The surgical treatment benefit was predominantly seen in women with hyperinsulinemia. Trial Registration: ClinicalTrials.gov Identifier: NCT01479452.

2.
Lancet Healthy Longev ; 4(10): e544-e551, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37716360

RESUMEN

BACKGROUND: Bariatric surgery in people with obesity is associated with a reduced overall cancer risk. Retrospective studies indicate that bariatric surgery specifically might reduce the risk of haematological cancers, but there is an absence of data from long-term, prospective studies. We therefore studied the association between bariatric surgery and haematological cancer in the Swedish Obese Subjects study. METHODS: The prospective controlled Swedish Obese Subjects study was designed to compare overall mortality in people who underwent bariatric surgery (n=2007) and usual care (n=2040). Participants were recruited through campaigns in mass media and at 480 primary health-care centres all over Sweden. The inclusion criteria were an age of 37-60 years and a BMI of 34 kg/m2 or more in men and 38 kg/m2 or more in women before or at the time of the examination. Haematological cancer events, including malignant lymphoma, myeloma, myeloproliferative neoplasms, as well as acute and chronic leukaemias, were captured from the Swedish Cancer Registry. The main outcome of this study was haematological cancer incidence and mortality. This study is registered with ClinicalTrials.gov (NCT01479452) and is ongoing. FINDINGS: A total of 4047 individuals with obesity were enrolled between Sept 1, 1987, and Jan 31, 2001. Overall, 34 participants in the surgery group and 51 participants in the usual care control group were diagnosed with haematological cancer during follow-up (hazard ratio [HR] 0·60; 95% CI 0·39-0·92; p=0·020). Moreover, there were three deaths by haematological cancer in the surgery group and 13 deaths in the control group (0·22; 0·06-0·76; p=0·017). Surgery was also associated with a reduced incidence of lymphoma (0·45; 0·23-0·88; p=0·020). A significant difference in treatment effect between men and women was found; bariatric surgery was associated with reduced incidence of haematological cancer in women (0·44; 0·26-0·74; p=0·002), but not in men (1·35; 0·58-3·17; p=0·489; interaction p=0·031). INTERPRETATION: Bariatric surgery is associated with a reduced incidence of haematological cancer, specifically in women. Health-care providers and policy makers working in the field of cancer prevention should consider bariatric surgery a primary prevention resource for people with obesity. FUNDING: The Swedish Research Council, the Swedish State under the agreement between the Swedish Government and the county councils, the Avtal om Läkarutbildning och Forskning agreement, the Health & Medical Care Committee of the Region Västra Götaland, the Swedish Heart Lung Foundation, Gothenburg Medical Society, and the Adlerbert Research Foundation. TRANSLATION: For the Swedish translation of the abstract see Supplementary Material section.


Asunto(s)
Cirugía Bariátrica , Neoplasias Hematológicas , Masculino , Humanos , Femenino , Estudios Prospectivos , Suecia/epidemiología , Incidencia , Estudios Retrospectivos , Obesidad/epidemiología , Obesidad/cirugía , Obesidad/complicaciones , Cirugía Bariátrica/efectos adversos , Neoplasias Hematológicas/epidemiología , Neoplasias Hematológicas/complicaciones
3.
Obesity (Silver Spring) ; 31(8): 2171-2177, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37475690

RESUMEN

OBJECTIVE: The goal of this study was to investigate whether bariatric surgery is associated with substance use disorder (SUD) with substances other than alcohol. METHODS: The prospective, controlled Swedish Obese Subjects study enrolled 2010 patients with obesity who underwent bariatric surgery (gastric bypass n = 265; vertical banded gastroplasty n = 1369; gastric banding n = 376) and 2037 matched control individuals receiving usual obesity care. Participants with SUD other than alcohol use disorder were identified using International Statistical Classification of Diseases (ICD) codes from the Swedish National Patient Register (covering treatment in hospital but not primary care). Those with a history of non-alcohol SUD were excluded. Median follow-up was 23.8 years. RESULTS: During follow-up, non-alcohol SUD incidence rates per 1000 person-years with 95% CI were 1.6 (0.8-3.1), 0.8 (0.5-1.2), 1.1 (0.5-2.2), and 0.6 (0.4-0.8) for gastric bypass, vertical banded gastroplasty, gastric banding, and control individuals, respectively. Only gastric bypass was associated with increased incidence of non-alcohol SUD (adjusted hazard ratio 2.54 [95% CI: 1.14-5.65], p = 0.022) compared with control participants. CONCLUSIONS: Gastric bypass surgery was associated with increased risk of non-alcohol SUD, and this should be considered in long-term postoperative care.


Asunto(s)
Alcoholismo , Cirugía Bariátrica , Derivación Gástrica , Gastroplastia , Obesidad Mórbida , Trastornos Relacionados con Sustancias , Humanos , Alcoholismo/complicaciones , Alcoholismo/epidemiología , Estudios Prospectivos , Suecia/epidemiología , Obesidad/epidemiología , Obesidad/cirugía , Obesidad/etiología , Cirugía Bariátrica/efectos adversos , Derivación Gástrica/efectos adversos , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/etiología , Trastornos Relacionados con Sustancias/cirugía , Obesidad Mórbida/cirugía
4.
Int J Obes (Lond) ; 47(10): 931-938, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37438611

RESUMEN

OBJECTIVES: To determine life expectancy and causes of death after bariatric surgery in relation to baseline type 2 diabetes (T2D) in the prospective, Swedish Obese Subjects study. METHODS: The study included 2010 patients with obesity who underwent bariatric surgery and 2037 matched controls, eligible for surgery. The surgery group underwent gastric bypass (n = 265), banding (n = 376), or vertical banded gastroplasty (n = 1369). The control group (n = 2037) received usual obesity care. Causes of death were obtained from the Swedish Cause of Death Register, case sheets and autopsy reports, in patients with baseline T2D (n = 392 surgery patients/n = 305 controls) or non-T2D (n = 1609 surgery patients/n = 1726 controls) during a median follow-up 26 years. RESULTS: In T2D and non-T2D subgroups, bariatric surgery was associated with increased life expectancy (2.1, 95% confidence interval (95% CI) 0.2-4.0; and 1.6, 0.5-2.7 years, respectively) and reduced overall mortality (adjusted hazard ratio (adjHR) = 0.77, 95% CI: 0.61-0.97; and 0.82, 0.72-0.94, respectively), and the treatment benefit was similar (interaction p = 0.615). Bariatric surgery was associated with reduced cardiovascular mortality in both subgroups (adjHR = 0.65, 95% CI: 0.46-0.91; and 0.70, 0.55-0.88, respectively (interaction p = 0.516)). CONCLUSIONS: Bariatric surgery is associated with similar reduction of overall and cardiovascular mortality and increased life expectancy regardless of baseline diabetes status.


Asunto(s)
Cirugía Bariátrica , Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/cirugía , Diabetes Mellitus Tipo 2/complicaciones , Estudios Prospectivos , Suecia/epidemiología , Obesidad/cirugía , Obesidad/complicaciones , Enfermedades Cardiovasculares/complicaciones
5.
J Phys Chem Lett ; 14(20): 4892-4900, 2023 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-37199508

RESUMEN

Superconducting circuits are among the most advanced quantum computing technologies; however, their performance is limited by losses found in surface oxides and disordered materials. In this work, we demonstrate the identification and spatial localization of a near-field signature of loss centers on tantalum films using terahertz scattering-type scanning near-field optical microscopy. By utilizing terahertz nanospectroscopy, we observe a localized excess vibrational mode around 0.5 THz and identify this resonance as the boson peak, a signature of amorphous materials. Grazing-incidence wide-angle X-ray scattering reveals that oxides on freshly solvent-cleaned samples are amorphous, whereas crystalline phases emerge after aging in air. Through nanoscale localization of defect centers, our findings provide valuable insights for the optimization of fabrication procedures for new low-loss superconducting circuits.

6.
EBioMedicine ; 92: 104621, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37209535

RESUMEN

BACKGROUND: Haematopoietic clones caused by somatic mutations with ≥2% variant allele frequency (VAF) increase with age and are linked to risk of haematological malignancies and cardiovascular disease. Recent observations suggest that smaller clones (VAF<2%) are also associated with adverse outcomes. Our aims were to determine the prevalence of clonal haematopoiesis driven by clones of variable sizes in individuals with obesity treated by usual care or bariatric surgery (a treatment that improves metabolic status), and to examine the expansion of clones in relation to age and metabolic dysregulation over up to 20 years. METHODS: Clonal haematopoiesis-driver mutations (CHDMs) were identified in blood samples from participants of the Swedish Obese Subjects intervention study. Using an ultrasensitive assay, we analysed single-timepoint samples from 1050 individuals treated by usual care and 841 individuals who had undergone bariatric surgery, and multiple-timepoint samples taken over 20 years from a subset (n = 40) of the individuals treated by usual care. FINDINGS: In this explorative study, prevalence of CHDMs was similar in the single-timepoint usual care and bariatric surgery groups (20.6% and 22.5%, respectively, P = 0.330), with VAF ranging from 0.01% to 31.15%. Clone sizes increased with age in individuals with obesity, but not in those who underwent bariatric surgery. In the multiple-timepoint analysis, VAF increased by on average 7% (range -4% to 24%) per year and rate of clone growth was negatively associated with HDL-cholesterol (R = -0.68, 1.74 E-04). INTERPRETATION: Low HDL-C was associated with growth of haematopoietic clones in individuals with obesity treated by usual care. FUNDING: The Swedish Research Council, The Swedish state under an agreement between the Swedish government and the county councils, the ALF (Avtal om Läkarutbildning och Forskning) agreement, The Swedish Heart-Lung Foundation, The Novo Nordisk Foundation, The European Research Council, The Netherlands Organisation for Scientific Research.


Asunto(s)
Cirugía Bariátrica , Enfermedades Cardiovasculares , Humanos , Adulto Joven , Adulto , Hematopoyesis Clonal/genética , Obesidad/genética , Obesidad/complicaciones , Cirugía Bariátrica/efectos adversos , Mutación , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/genética
7.
Sci Total Environ ; 883: 163607, 2023 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-37098395

RESUMEN

While carbon is a critically important natural element cycling through the soil profile of agricultural systems, few studies have examined the flux of dissolved organic carbon (OC) and inorganic carbon (IC) through artificially-drained cropped fields. In this study, we monitored eight tile outlets, nine groundwater wells and the receiving stream during a March to November period in 2018 to quantify subsurface IC and OC flux from tiles and groundwater to a perennial stream from a single cropped field in north-central Iowa. Results showed that carbon export from the field was dominated by IC losses through subsurface drainage tiles that were 20× higher than dissolved OC concentration in tiles, groundwater and in Hardin Creek. IC loads from tiles comprised approximately 96 % of the total carbon export. Detailed soil sampling within the field quantified TC stocks to a 1.2 m depth (246,514 kg/ha), and based on the maximum annual rate of IC loss from the field (553 kg/ha per year), we estimated that approximately 0.23 % of the TC content (0.32 % of the TOC content and 0.70 % of the TIC content) of the shallow soils was lost in a single year. Loss of dissolved carbon from the field is likely offset by reduced tillage and additions of lime. Study results suggest that attention should be given to improved monitoring of aqueous total carbon export from fields for accurate accounting of carbon sequestration performance.

8.
Chem Commun (Camb) ; 59(20): 2954-2957, 2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36804728

RESUMEN

Two different metal-organic frameworks with either a honeycomb or Kagome structure were grown on Cu(111) using para-aminophenol molecules and native surface adatoms. Although both frameworks are made up from the same chemical species, they are structurally different emphasizing the critical role being played by the reaction conditions during their growth. This work highlights the importance of the balance between thermodynamics and kinetics in the final structure of surface-supported metal-organic networks.

9.
ACS Nano ; 17(4): 3958-3965, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36757212

RESUMEN

Molecular motors have chemical properties that enable unidirectional motion, thus breaking microscopic reversibility. They are well studied in solution, but much less is known regarding their behavior on solid surfaces. Here, single motor molecules adsorbed on a Cu(111) surface are excited by voltages pulses from an STM tip, which leads to their rotation around a fixed pivot point. Comparison with calculations shows that this axis results from a chemical bond of a sulfur atom in the chemical structure and a metal atom of the surface. While statistics show approximately equal rotations in both directions, clockwise and anticlockwise, a detailed study reveals that these motions are enantiomer-specific. Hence, the rotation direction of each individual molecule depends on its chirality, which can be determined from STM images. At first glance, these dynamics could be assigned to the activation of the motor molecule, but our results show that this is unlikely as the molecule remains in the same conformation after rotation. Additionally, a control molecule, although it lacks unidirectional rotation in solution, also shows unidirectional rotation for each enantiomer. Hence, it seems that the unidirectional rotation is not specifically related to the motor property of the molecule. The calculated energy barriers for motion show that the propeller-like motor activity requires higher energy than the simple rotation of the molecule as a rigid object, which is therefore preferred.

10.
Cryst Growth Des ; 22(7): 4228-4235, 2022 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-35818388

RESUMEN

Compared to Si, GaAs offers unique material advantages such as high carrier mobility and energy conversion efficiency, making GaAs a leading competitor to replace Si on several technological fronts related to optoelectronics and solar energy conversion. Alloying the GaAs lattice with elemental In allows the direct bandgap of the resulting ternary alloy to be tuned across the near-infrared (NIR) region of the electromagnetic spectrum from ∼0.9 to 3.5 µm. However, methods of fabricating high-quality crystalline GaAs are currently limited by their high cost and low throughput relative to Si growth methods, suggesting the need for alternative low-cost routes to GaAs growth and alloying. This research documents the first instance in the literature of the electrodeposition and controlled alloying of polycrystalline In x Ga1-x As films at ambient pressure and near-room temperature using the electrochemical liquid-liquid-solid (ec-LLS) process. X-ray diffraction and Raman spectroscopy support the polycrystalline growth of (111)-oriented In x Ga1-x As films. Consistent redshifts of the GaAs-like TO peaks were observed in the Raman data as the In composition of the liquid metal electrode was increased. Optical bandgaps, determined via diffuse reflectance measurements, displayed a consistent decrease with the increase in the In composition of In x Ga1-x As films. While Raman, diffuse reflectance, and energy-dispersive X-ray spectroscopy data support controlled alloying efforts, all techniques suggest an overall decrease of the In/Ga ratios present in deposited films relative to those of the liquid metal electrodes. These results lend support for the continued development of ec-LLS as a viable method of achieving crystalline growth and alloying of binary and ternary semiconductor material systems using a benchtop setup under ambient pressure and near-room temperature.

11.
12.
J Phys Chem C Nanomater Interfaces ; 126(21): 9034-9040, 2022 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-35686222

RESUMEN

Molecular motors have been intensely studied in solution, but less commonly on solid surfaces that offer fixed points of reference for their motion and allow high-resolution single-molecule imaging by scanning probe microscopy. Surface adsorption of molecules can also alter the potential energy surface and consequently preferred intramolecular conformations, but it is unknown how this affects motor molecules. Here, we show how the different conformations of motor molecules are modified by surface adsorption using a combination of scanning tunneling microscopy and density functional theory. These results demonstrate how the contact of a motor molecule with a solid can affect the energetics of the molecular conformations.

13.
Obes Sci Pract ; 8(1): 21-31, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35127120

RESUMEN

OBJECTIVE: Adipose tissue is a specialized endocrine organ that is involved in modulating whole-body energy homeostasis and expresses a specific subset of genes, which may play a role in adipose tissue metabolism. The aim of this study was to search for novel adipose tissue-specific genes using a tissue panel of RNAseq expression profiles. METHODS: RNAseq expression profiles from 53 human tissues were downloaded from the GTex database. SLC19A3 expression was analyzed by microarray or real-time PCR in two sets of paired subcutaneous and omental adipose tissue samples, in two studies with adipose tissue from persons with high or low body mass index (BMI), in adipose tissue from patients who underwent weight loss with a very-low caloric diet and during preadipocyte-adipocyte differentiation. RESULTS: The RNAseq-based tissue distribution expression screen identified SLC19A3 (encoding the thiamine transporter 2) as adipose tissue-specific. SLC19A3 expression was higher in subcutaneous compared with omental adipose tissue in both sample sets (p = 0.043 and p < 0.001). Preadipocyte differentiation towards adipocytes resulted in increased SLC19A3 gene expression (p = 0.018 or less at all-time points). Subcutaneous adipose tissue expression of SLC19A3 was lower in persons with high BMI in both cohorts (p = 0.008, and p < 0.001) and increased during a weight-loss intervention (p = 0.006). CONCLUSION: The specific adipose tissue expression pattern of SLC19A3, together with its regulation in obesity and during weight loss, indicate that it plays a key role in adipocyte metabolism.

14.
Diabetes Care ; 45(2): 444-450, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34799430

RESUMEN

OBJECTIVE: Obesity and type 2 diabetes are associated with serious adverse health effects, including cancer. Although bariatric surgery has been shown to reduce cancer risk in patients with obesity, the effect of bariatric surgery on cancer risk in patients with obesity and diabetes is less studied. We therefore examined the long-term incidence of cancer after bariatric surgery and usual care in patients with obesity and diabetes in the matched prospective Swedish Obese Subjects (SOS) study. RESEARCH DESIGN AND METHODS: The SOS study examines long-term outcomes following bariatric surgery or usual care. The current analysis includes 701 patients with obesity and type 2 diabetes at baseline, 393 of whom underwent bariatric surgery and 308 who received conventional obesity treatment. Information on cancer events was obtained from the Swedish National Cancer Register. Median follow-up time was 21.3 years (interquartile range 17.6-24.8 years, maximum 30.7 years). RESULTS: During follow-up, the incidence rate for first-time cancer was 9.1 per 1,000 person-years (95% CI 7.2-11.5) in patients with obesity and diabetes treated with bariatric surgery and 14.1 per 1,000 person-years (95% CI 11.2-17.7) in patients treated with usual obesity care (adjusted hazard ratio 0.63 [95% CI 0.44-0.89], P = 0.008). Moreover, surgery was associated with reduced cancer incidence in women (0.58 [0.38-0.90], P = 0.016), although the sex-treatment interaction was nonsignificant (P = 0.630). In addition, diabetes remission at the 10-year follow-up was associated with reduced cancer incidence (0.40 [0.22-0.74], P = 0.003). CONCLUSIONS: These results suggest that bariatric surgery prevents cancer in patients with obesity and diabetes and that durable diabetes remission is associated with reduced cancer risk.


Asunto(s)
Cirugía Bariátrica , Diabetes Mellitus Tipo 2 , Neoplasias , Cirugía Bariátrica/efectos adversos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Humanos , Incidencia , Neoplasias/complicaciones , Neoplasias/epidemiología , Neoplasias/cirugía , Obesidad/complicaciones , Obesidad/epidemiología , Obesidad/cirugía , Estudios Prospectivos , Suecia/epidemiología
15.
J Environ Manage ; 299: 113647, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34523537

RESUMEN

Shallow constructed ponds are abundant landscape features in the midwestern United States, suggested as an edge of field best management practice (BMP) in voluntary nutrient reduction strategies. The efficacy of such features is highly uncertain, however, and previous studies have lacked sufficient temporal resolution to determine N and P removals during critical periods of transport. We utilized high-frequency in-situ measurements and flow-weighted grab sampling to determine water and nutrient budgets for a typical constructed "farm pond" in central Iowa situated within the Iowa Southern Drift Plain. Our monitoring approach yielded insight into in-stream nitrogen processing and the relative importance of transport-vs. supply-limited N delivery. Diel patterns in NO3-N observed during early Spring, prior to canopy closure, revealed that in-stream primary production and NO3-N assimilation can influence downstream N delivery in a stream with nitrate pollution (mean annual NO3-N of nearly 5 mg/L). Analysis of discharge-concentration hysteresis for NO3-N showed a shift from transport to supply limitation for NO3-N delivery over the growing season, influenced by antecedent moisture, with wet antecedent conditions leading to supply limitation. Significant NO3-N removal (64% of 19.8 kg/ha inputs) occurred within the 4.2 ha pond (230 ha watershed), but total N removal was much lower (36% removal of 22.3 kg/ha inputs). The lower total N removal highlights the importance of both particulate N and dissolved organic N and ammonia export to the N budgets of hypereutrophic small ponds. Total P removal in the pond was only 8% of 2.3 kg/ha inputs, likely due to internal loading of recent and legacy sedimentary P within the pond. High-flow events dominated N and P inputs, during which removal efficacy of the pond was significantly diminished. Poor process performance during critical moments may partially explain lower than expected water quality improvements post-BMP implementation. Accordingly, shifting hydroclimatic regimes (e.g., frequency of intense rainfall events) will impact the efficacy of small ponds and other edge of field BMPs for nutrient reduction.


Asunto(s)
Estanques , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Granjas , Iowa , Nitrógeno/análisis , Nutrientes , Fósforo/análisis , Contaminantes Químicos del Agua/análisis
16.
Front Microbiol ; 12: 691584, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34168636

RESUMEN

All perennial plants harbor diverse endophytic fungal communities, but why they tolerate these complex asymptomatic symbioses is unknown. Using a multi-pronged approach, we conclusively found that a dryland grass supports endophyte communities comprised predominantly of latent saprophytes that can enhance localized nutrient recycling after senescence. A perennial bunchgrass, Stipagrostis sabulicola, which persists along a gradient of extreme abiotic stress in the hyper-arid Namib Sand Sea, was the focal point of our study. Living tillers yielded 20 fungal endophyte taxa, 80% of which decomposed host litter during a 28-day laboratory decomposition assay. During a 6-month field experiment, tillers with endophytes decomposed twice as fast as sterilized tillers, consistent with the laboratory assay. Furthermore, profiling the community active during decomposition using next-generation sequencing revealed that 59-70% of the S. sabulicola endophyte community is comprised of latent saprophytes, and these dual-niche fungi still constitute a large proportion (58-62%) of the litter community more than a year after senescence. This study provides multiple lines of evidence that the fungal communities that initiate decomposition of standing litter develop in living plants, thus providing a plausible explanation for why plants harbor complex endophyte communities. Using frequent overnight non-rainfall moisture events (fog, dew, high humidity), these latent saprophytes can initiate decomposition of standing litter immediately after tiller senescence, thus maximizing the likelihood that plant-bound nutrients are recycled in situ and contribute to the nutrient island effect that is prevalent in drylands.

17.
Diabetes Obes Metab ; 23(8): 1917-1925, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33961331

RESUMEN

AIMS: To examine the incidence of hypoglycaemia-related events over a period of up to 31 years in patients treated with bariatric surgery in the prospective, controlled Swedish Obese Subjects (SOS) study. MATERIALS AND METHODS: The SOS study (n = 4047) is a prospective controlled intervention study. The present analysis included 1989 patients treated with bariatric surgery and 2027 control patients with obesity who received usual care. Diagnosed hypoglycaemia and events commonly attributed to hypoglycaemia (confusion, syncope, epilepsy and seizures), requiring hospital or specialist outpatient treatment, were identified by searching the National Patient Register. Analyses were stratified by baseline glycaemic status. Hazard ratios were adjusted for inclusion year, age, sex, smoking, glycated haemoglobin (HbA1c) level and body mass index at baseline. At the time of analysis (December 31, 2018), the median follow-up was 22 years. RESULTS: Compared with usual care, bariatric surgery was associated with increased incidence of hypoglycaemia-related events in patients without baseline diabetes (168 and 219 events, respectively; log-rank P = .011), with a more pronounced risk during the first years of follow-up (test of time-treatment interaction P = .010). Multivariate analyses in patients without baseline diabetes indicated that male sex (P < .001), older age (P = .001) and higher HbA1c levels (P = .006) were associated with hypoglycaemia-related events. No association was found between risk of hypoglycaemia-related events and bariatric surgery in patients with baseline diabetes. CONCLUSIONS: Bariatric surgery is associated with an increased incidence of hypoglycaemia-related events in patients without baseline diabetes, especially during the first years after treatment.


Asunto(s)
Cirugía Bariátrica , Hipoglucemia , Anciano , Cirugía Bariátrica/efectos adversos , Humanos , Hipoglucemia/epidemiología , Incidencia , Masculino , Obesidad/complicaciones , Obesidad/epidemiología , Estudios Prospectivos , Suecia/epidemiología
18.
PLoS One ; 16(3): e0248550, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33764991

RESUMEN

Bariatric surgery in patients with obesity is generally considered to reduce cancer risk in patients with obesity. However, for colorectal cancer some studies report an increased risk with bariatric surgery, whereas others report a decreased risk. These conflicting results demonstrate the need of more long-term studies analyzing the effect of bariatric surgery on colorectal cancer risk. Therefore, data from the Swedish Obese Subjects (SOS) study, ClinicalTrials.gov identifier: NCT01479452, was used to examine the impact of bariatric surgery on long-term incidence of colorectal cancer. The SOS study includes 2007 patients who underwent bariatric surgery and 2040 contemporaneously matched controls who received conventional obesity treatment. Patients in the surgery group underwent gastric bypass (n = 266), banding (n = 376) or vertical banded gastroplasty (n = 1365). Information on colorectal cancer events was obtained from the Swedish National Cancer Registry. Median follow-up was 22.2 years (inter-quartile range 18.3-25.2). During follow up there were 58 colorectal cancer events in the surgery group and 67 colorectal cancer events in the matched control group with a hazard ratio (HR) of 0.79 (95% CI:0.55-1.12; p = 0.183). After adjusting for age, body mass index, alcohol intake, smoking status, and diabetes, the adjusted HR was 0.89 (95% CI:0.62-1.29; p = 0.551). When analyzing rectal cancer events separately- 19 events in the surgery group and 31 events in the control group-a decreased risk of rectal cancer with surgery was observed (HR = 0.56; 95% CI:0.32-0.99; p = 0.045, adjusted HR = 0.61 (95% CI:0.34-1.10; p = 0.099), while the risk of colon cancer was unchanged. To conclude- in this long-term, prospective study, bariatric surgery was not associated with altered colorectal cancer risk.


Asunto(s)
Cirugía Bariátrica/efectos adversos , Neoplasias Colorrectales/epidemiología , Obesidad/terapia , Adulto , Estudios Controlados Antes y Después , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Suecia/epidemiología
19.
Front Microbiol ; 12: 596517, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33716999

RESUMEN

Non-rainfall moisture (fog, dew, and water vapor; NRM) is an important driver of plant litter decomposition in grasslands, where it can contribute significantly to terrestrial carbon cycling. However, we still do not know whether microbial decomposers respond differently to NRM and rain, nor whether this response affects litter decomposition rates. To determine how local moisture regimes influence decomposer communities and their function, we examined fungal communities on standing grass litter at an NRM-dominated site and a rain-dominated site 75 km apart in the hyper-arid Namib Desert using a reciprocal transplant design. Dominant taxa at both sites consisted of both extremophilic and cosmopolitan species. Fungal communities differed between the two moisture regimes with environment having a considerably stronger effect on community composition than did stage of decomposition. Community composition was influenced by the availability of air-derived spores at each site and by specialization of fungi to their home environment; specifically, fungi from the cooler, moister NRM Site performed worse (measured as fungal biomass and litter mass loss) when moved to the warmer, drier rain-dominated site while Rain Site fungi performed equally well in both environments. Our results contribute to growing literature demonstrating that as climate change alters the frequency, magnitude and type of moisture events in arid ecosystems, litter decomposition rates may be altered and constrained by the composition of existing decomposer communities.

20.
Diabetes ; 70(3): 680-695, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33408126

RESUMEN

Elucidation of mechanisms that govern lipid storage, oxidative stress, and insulin resistance may lead to improved therapeutic options for type 2 diabetes and other obesity-related diseases. Here, we find that adipose expression of the small neutral amino acid transporter SLC7A10, also known as alanine-serine-cysteine transporter-1 (ASC-1), shows strong inverse correlates with visceral adiposity, insulin resistance, and adipocyte hypertrophy across multiple cohorts. Concordantly, loss of Slc7a10 function in zebrafish in vivo accelerates diet-induced body weight gain and adipocyte enlargement. Mechanistically, SLC7A10 inhibition in human and murine adipocytes decreases adipocyte serine uptake and total glutathione levels and promotes reactive oxygen species (ROS) generation. Conversely, SLC7A10 overexpression decreases ROS generation and increases mitochondrial respiratory capacity. RNA sequencing revealed consistent changes in gene expression between human adipocytes and zebrafish visceral adipose tissue following loss of SLC7A10, e.g., upregulation of SCD (lipid storage) and downregulation of CPT1A (lipid oxidation). Interestingly, ROS scavenger reduced lipid accumulation and attenuated the lipid-storing effect of SLC7A10 inhibition. These data uncover adipocyte SLC7A10 as a novel important regulator of adipocyte resilience to nutrient and oxidative stress, in part by enhancing glutathione levels and mitochondrial respiration, conducive to decreased ROS generation, lipid accumulation, adipocyte hypertrophy, insulin resistance, and type 2 diabetes.


Asunto(s)
Adipocitos/metabolismo , Sistema de Transporte de Aminoácidos y+/metabolismo , Obesidad/metabolismo , Obesidad/fisiopatología , Células 3T3-L1 , Sistema de Transporte de Aminoácidos y+/genética , Animales , Western Blotting , Diabetes Mellitus Tipo 2/metabolismo , Genotipo , Glutatión/metabolismo , Humanos , Resistencia a la Insulina/fisiología , Ratones , Especies Reactivas de Oxígeno/metabolismo , Análisis de Secuencia de ARN , Pez Cebra
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