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2.
Chemosphere ; 335: 139010, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37236281

ABSTRACT

Heavy metals (HMs) and metalloids (Ms) such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) represent serious environmental threats due to their wide abundance and high toxicity. Contamination of water and soils by HMs and Ms from natural or anthropogenic sources is of great concern in agricultural production due to their toxic effects on plants, adversely affecting food safety and plant growth. The uptake of HMs and Ms by Phaseolus vulgaris L. plants depends on several factors including soil properties such as pH, phosphate, and organic matter. High concentrations of HMs and Ms could be toxic to plants due to the increased generation of reactive oxygen species (ROS) such as (O2•-), (•OH), (H2O2), and (1O2), and oxidative stress due to an imbalance between ROS generation and antioxidant enzyme activity. To minimize the effects of ROS, plants have developed a complex defense mechanism based on the activity of antioxidant enzymes such as SOD, CAT, GPX, and phytohormones, especially salicylic acid (SA) that can reduce the toxicity of HMs and Ms. This review focuses on evaluating the accumulation and translocation of As, Cd, Hg, and Pb in Phaseolus vulgaris L. plants and on their possible effects on the growth of Phaseolus vulgaris L. in soil contaminated with these elements. The factors that affect the uptake of HMs and Ms by bean plants, and the defense mechanisms under oxidative stress caused by the presence of As, Cd, Hg, and Pb are also discussed. Furthermore, future research on mitigating HMs and Ms toxicity in Phaseolus vulgaris L. plants is highlighted.


Subject(s)
Arsenic , Mercury , Metalloids , Metals, Heavy , Phaseolus , Soil Pollutants , Cadmium/toxicity , Reactive Oxygen Species/pharmacology , Antioxidants/pharmacology , Hydrogen Peroxide/pharmacology , Lead/pharmacology , Soil Pollutants/analysis , Metals, Heavy/analysis , Arsenic/analysis , Mercury/toxicity , Plants , Soil/chemistry
3.
J Appl Microbiol ; 131(1): 36-49, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33222338

ABSTRACT

AIMS: This study describes the physicochemical and genomic characterization of phage vB_Vc_SrVc9 and its potential for phage therapy application against a pathogenic Vibrio campbellii strain. METHODS AND RESULTS: A lytic phage vB_Vc_SrVc9 against V. campbellii was isolated from shrimp farm sediment, and characterized physicochemical and genomically. The use of vB_Vc_SrVc9 phage increased the survival in brine shrimp Artemia franciscana and reduced presumptive V. campbellii to nondetectable numbers. Genomic analysis showed a genome with a single contig of 43·15 kb, with 49 predicted genes and no tRNAs, capable of recognizing and generating complete inhibition zones of three Vibrio sp. CONCLUSIONS: To our knowledge vB_Vc_SrVc9 is a lytic phage that could be used against Vibrio infections, reducing vibrio presence without any apparent impact over the natural microbiota at the family level in 28 libraries tested. SIGNIFICANCE AND IMPACT OF THE STUDY: vB_Vc_SrVC9 is a novel phage and ecofriendly alternative for therapeutic applications and biotechnological purposes because is stable at different environmental conditions, has the potential to eliminate several strains, and has a short latent period with a good burst size. Therefore, the use of phages, which are natural killers of bacteria, represents a promising strategy to reduce the mortality of farmed organisms caused by pathogenic bacteria.


Subject(s)
Artemia/microbiology , Bacteriophages/physiology , Vibrio Infections/veterinary , Vibrio/virology , Animals , Bacteriophages/genetics , Bacteriophages/isolation & purification , Genes, Viral , Genome, Viral , Microbiota , Phage Therapy/veterinary , Vibrio Infections/microbiology , Vibrio Infections/prevention & control
4.
QJM ; 114(2): 111-116, 2021 Apr 27.
Article in English | MEDLINE | ID: mdl-33151302

ABSTRACT

BACKGROUND: B-lines have been associated with adverse clinical outcomes in patients with heart failure (HF) when found at hospital discharge or during outpatient visits. Whether lung ultrasound (LUS) assessed B-lines may predict in-hospital mortality in patients with acute HF is still undetermined. AIM: To evaluate the association between B-lines on admission and in-hospital mortality among patients admitted with acute HF. METHODS: Hand-held LUS was used to examine patients with acute HF. LUS was performed in eight chest zones with a pocket ultrasound device and analyzed offline. The association between B-lines and in-hospital mortality was assessed using Cox regression models. RESULTS: We included 62 patients with median age 56 years, 69.4% men, and median left ventricle ejection fraction 25%. The sum of B-lines ranged from 0 to 53 (median 6.5). An optimal receiver operating characteristic-determined cut-off of ≥19 B-lines demonstrated a sensitivity of 57% and a specificity of 86% (area under the curve 0.788) for in-hospital mortality. The incremental prognostic value of LUS when compared with lung crackles or peripheral edema by integrated discrimination improvement was 12.96% (95% CI: 7.0-18.8, P = 0.02). Patients with ≥19 B-lines had a 4-fold higher risk of in-hospital mortality (HR 4.38; 95% CI: 1.37-13.95, P < 0.01). CONCLUSION: In patients admitted with acute HF, point-of-care LUS measurements of pulmonary congestion (B-lines) are associated with in-hospital mortality.


Subject(s)
Heart Failure , Point-of-Care Systems , Female , Hospital Mortality , Humans , Lung/diagnostic imaging , Male , Middle Aged , Prognosis , Ultrasonography
5.
Neumol. pediátr. (En línea) ; 16(4): 167-171, 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1362145

ABSTRACT

La exposición a las emanaciones de incendios forestales es un importante problema de salud pública nacional e internacional. El cambio climático que conlleva sequía y aumento de la temperatura estival aumenta el riesgo y magnitud de los episodios de incendios forestales, generándose grandes incendios cuyas emanaciones pueden afectar a poblaciones distanciadas del epicentro. La asociación entre la exposición a las emanaciones de los incendios forestales, el aumento de las concentraciones de material particulado aéreo y la morbilidad respiratoria (exacerbación de asma y enfermedades respiratorias crónicas) ha sido evidenciada en diversos estudios. Sin embargo, es difícil realizar un metaanálisis de ellos, ya que la metodología empleada es muy disímil. Entre los principales mecanismos de morbilidad se encontrarían: la producción de citoquinas proinflamatorias, la activación endotelial y la disfunción del sistema nervioso autónomo. Ante la exposición al humo de incendios forestales, se produce daño tisular, aumento de los mecanismos protrombóticos, aumento de la presión arterial y cambios en el ritmo cardiaco, que explicaría los efectos cardiovasculares. Los sujetos con patología cardiovascular preexistente podrían tener mayor riesgo cardiovascular; sin embargo, existen factores confundentes en esta asociación. Por otra parte, el posible riesgo cancerígeno con la exposición a estas emanaciones requiere mayores estudios poblacionales.


Exposure to forest fire fumes is a major national and international public health issue. Climate change that leads to drought and increased summer temperature increases the risk and magnitude of wildfires episodes, generating mega-fires whose fumes not only affect the boundary population, but they may become transcontinental. Association between exposure to forest fire fumes, mainly increased concentrations of air born particulate matter and respiratory morbidity (exacerbation of asthma and chronic respiratory diseases) has been evidenced by diverse studies. However, it is difficult to carry out meta-analysis with them since the methodology used is dissimilar. Among the main causes of morbidity have been postulated the production of pro-inflammatory cytokines, endothelial activation and dysfunction of the autonomic nervous system. Occurrence of tissue damage, increased prothrombotic mechanisms, increased blood pressure and changes in heart rate, would explain the cardiovascular effects associated with exposure to smoke from these fires. However, epidemiological outcomes have not been entirely consistent, as the association between cardiovascular morbidity and exposure to wildfire fumes may be mixed with confounding factors. Despite this, patients with pre-existing cardiovascular pathology may be at increased risk. Finally, the potential risk of carcinogen with exposure to these fumes requires further population studies.


Subject(s)
Humans , Respiratory Tract Diseases/epidemiology , Wildfires , Air Pollution/adverse effects , Particulate Matter/adverse effects , Respiratory Tract Diseases/etiology , Asthma/etiology , Asthma/epidemiology , Cardiovascular Diseases/etiology , Cardiovascular Diseases/epidemiology , Public Health
6.
Mol Metab ; 30: 72-130, 2019 12.
Article in English | MEDLINE | ID: mdl-31767182

ABSTRACT

BACKGROUND: The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent ß-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity. SCOPE OF REVIEW: In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases. MAJOR CONCLUSIONS: Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders.


Subject(s)
Glucagon-Like Peptide 1/metabolism , Glucagon-Like Peptide 1/pharmacology , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/metabolism , Gastric Inhibitory Polypeptide/metabolism , Glucagon-Like Peptide-1 Receptor/metabolism , Glucose/metabolism , Humans , Hypoglycemic Agents/therapeutic use , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/metabolism , Obesity/metabolism , Receptors, Glucagon/metabolism
7.
Rev. chil. enferm. respir ; 35(1): 49-57, mar. 2019. graf
Article in Spanish | LILACS | ID: biblio-1003646

ABSTRACT

Los incendios forestales representan un problema creciente de la salud pública a nivel mundial, especialmente para la población más vulnerable (niños, ancianos, embarazadas y portadores de enfermedades cardiovasculares o respiratorias crónicas) expuesta al humo y a otros contaminantes aéreos. A diferencia de la contaminación atmosférica habitual de grandes urbes, aquella derivada de los incendios forestales tiene una composición diferente y su ocurrencia es esporádica y difícil de prever. La exposición a contaminantes atmosféricos derivados de incendios forestales se asocia a aumento de la morbilidad respiratoria y cardiovascular, mediada por una respuesta inflamatoria pulmonar y sistémica, estrés oxidativo y disfunción endotelial. En sujetos expuestos a humo de incendios forestales se ha observado un aumento en la producción de citoquinas pro-inflamatorias, activación endotelial y disfunción del sistema nervioso autónomo, que produce daño tisular, aumento de los mecanismos protrombóticos, aumento de la presión arterial y cambios en el ritmo cardiaco. Esta revisión analiza los mecanismos que han sido involucrados en generar efectos nocivos para la salud de seres humanos expuestos a material particulado y gases emanados de incendios forestales.


Wildfires represent a growing global public health issue, especially to the most vulnerable segment of the population (children, old people, pregnant women, patients with cardiovascular or respiratory diseases) exposed to smoke and other air borne contaminants generated from these events. In contrast to great cities ' usual atmospheric pollution, that derives from forest fires differ in composition and its occurrence is sporadic and usually unpredictable. Exposure to atmospheric pollutants derived from forest fires has been associated to increased respiratory and cardiovascular morbidity, mediated by an inflammatory systemic response, oxidative stress and endothelial dysfunction. In people exposed to forest fire smoke an increased production of pro-inflammatory cytokines, endothelial activation and autonomic nervous system dysfunction has been observed, that leads to tissue injury, increased prothrombotic response, increased blood pressure and changes in heart rhythm. This review analyzes the mechanisms that have been involved in generating harmful health effects in humans exposed to inhaled particulate matter and gases steaming from wildfires.


Subject(s)
Humans , Cardiovascular Diseases/chemically induced , Wildfires , Air Pollution/adverse effects , Lung Diseases/chemically induced , Cardiovascular Diseases/physiopathology , Cerebrovascular Disorders/chemically induced , Cytokines/metabolism , Reactive Oxygen Species/metabolism , Oxidative Stress , Inhalation Exposure , Air Pollutants/adverse effects , Particulate Matter/adverse effects , Lung Diseases/physiopathology
8.
Acta Trop ; 191: 252-260, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30633896

ABSTRACT

Leishmaniasis is a zoonotic disease caused by intracellular protozoa of the Leishmania genus that are spread and transmitted by sandflies. Natural infection and clinical disease in domestic cats and dogs appear to be rare or perhaps largely under-reported in endemic areas. However, previous reports on infected domestic animals usually implicate the same Leishmania species that affect humans in tropical and subtropical areas of the world suggesting a potential role for zoonotic transmission. In the present study we assessed a representative sample of cats and dogs from endemic urban / suburban areas of Lara state in central western Venezuela. In both dogs and cats, cutaneous disease exhibits a spectrum of manifestations that range from single papules or nodules, which may evolve into ulcerative, plaque-like or scaly lesions. Cytochrome b (cyt b) PCR gene sequence analysis revealed L. mexicana as the causative agent in all cases, including two human cases proceeding from the same study area at the same time the study was carried out. In order to improve our understanding on feline/canine infection with Leishmania mexicana, and address potential zoonotic concerns it is necessary to characterize its enzootic reservoirs and vectors as well as the possible anthropophilic players linking to the peridomestic and domestic cycles.


Subject(s)
Cat Diseases/epidemiology , Cat Diseases/parasitology , Dog Diseases/epidemiology , Dog Diseases/parasitology , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/parasitology , Animals , Animals, Domestic , Cats , Dogs , Humans , Polymerase Chain Reaction/veterinary , Psychodidae/parasitology , Venezuela/epidemiology , Zoonoses/epidemiology , Zoonoses/parasitology
9.
Transbound Emerg Dis ; 64(6): 1655-1660, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28921885

ABSTRACT

A novel equine arteritis virus (EAV) was isolated and sequenced from feral donkeys in Chile. Phylogenetic analysis indicates that the new virus and South African asinine strains diverged at least 100 years from equine EAV strains. The results indicate that asinine strains belonged to a different EAV genotype.


Subject(s)
Arterivirus Infections/veterinary , Equartevirus/isolation & purification , Equidae , Animals , Arterivirus Infections/virology , Chile , Equartevirus/classification , Equartevirus/genetics , Male , Phylogeny , Polymerase Chain Reaction/veterinary , Viral Proteins/analysis
10.
Domest Anim Endocrinol ; 61: 100-107, 2017 10.
Article in English | MEDLINE | ID: mdl-28783504

ABSTRACT

The male gonadal tissue can be a sensitive target to the reprogramming effects of testosterone (T) during prenatal development. We have demonstrated that male lambs born to dams receiving T during pregnancy-a model system to the polycystic ovary syndrome (PCOS)-show a decreased number of germ cells early in life, and when adult, a reduced amount of sperm and ejaculate volume. These findings are a key to put attention to the male offspring of women bearing PCOS, as they are exposed to increased levels of androgen during pregnancy which can reprogram their reproductive outcome. A possible origin of these defects can be a disruption in the expression of the anti-Müllerian hormone (AMH), due to its critical role in gonadal function at many postnatal stages. Therefore, we addressed the impact of prenatal T excess on the expression of AMH and factors related to its expression like AP2, SOX9, FSHR, and AR in the testicular tissue through real-time PCR during the peripubertal age. We also analyzed the testicular morphology and quantified the number of Sertoli cells and germ cells to evaluate any further defect in the testicle. Experiments were performed in rams at 24 wk of age, hence, prior puberty. The experimental animals (T-males) consisted of rams born to mothers receiving 30 mg testosterone twice a wk from Day 30 to 90 of pregnancy and then increased to 40 mg until Day 120 of pregnancy. The control males (C-males) were born to mothers receiving the vehicle of the hormone. We found a significant increase in the expression of the mRNA of AMH and SOX9, but not of the AP2, FHSR nor AR, in the T-males. Moreover, T-males showed a dramatic decrease in the number of germ cells, together with a decrease in the weight of their testicles. The findings of the present study show that before puberty, T-males are manifesting clear signs of disruption in the gonadal functions probably due to an alteration in the expression pattern of the AMH gene. The precise way by which T reprograms the expression of AMH gene remains to be established.


Subject(s)
Gene Expression Regulation, Developmental/drug effects , Sexual Maturation/drug effects , Sheep/physiology , Testis/physiology , Testosterone/administration & dosage , Animals , Anti-Mullerian Hormone , Body Weight/drug effects , Female , Male , Organ Size/drug effects , Pregnancy , Prenatal Exposure Delayed Effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sexual Maturation/physiology , Testosterone/pharmacology
11.
Med. interna Méx ; 33(4): 526-532, jul.-ago. 2017. graf
Article in Spanish | LILACS | ID: biblio-894293

ABSTRACT

Resumen: El infarto de miocardio es causa importante de muerte y discapacidad en todo el mundo. Es secundario al desequilibrio entre la relación aporte/consumo de oxígeno miocárdico y tiene características clínicas propias. En este artículo se comunica el caso clínico de un paciente con múltiples factores que generaron un desequilibrio en la relación aporte/consumo de oxígeno del miocardio, además de elevación significativa del segmento ST en el electrocardiograma y marcada elevación de la troponina I. Todos estos cambios revirtieron con el inicio del manejo médico de los factores que contribuyeron a este desequilibrio.


Abstract: Myocardial infarction (MI) is a major cause of death and disability worldwide. Type 2 MI is secondary to an imbalance in myocardial oxygen delivery/consumption relationship and has its own clinical characteristics. We report the case of a patient with multiple factors that created an imbalance in the myocardial oxygen delivery/consumption relationship and also had significantly ST segment elevation on the electrocardiogram and marked elevation of troponin I. All these changes reversed with the onset of medical management of the factors that contributed to this imbalance.

12.
Rev Sci Instrum ; 88(1): 013504, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28147637

ABSTRACT

We describe the design and function of a new time and space resolved x-ray spectrometer for use in Z-pinch inertial confinement fusion and radiation source development experiments. The spectrometer is designed to measure x-rays in the range of 0.5-1.5 Å (8-25 keV) with a spectral resolution λ/Δλ ∼ 400. The purpose of this spectrometer is to measure the time- and one-dimensional space-dependent electron temperature and density during stagnation. These relatively high photon energies are required to escape the dense plasma created at stagnation and to obtain sensitivity to electron temperatures ≳3 keV. The spectrometer is of the Cauchois type, employing a large 30 × 36 mm2, transmissive quartz optic for which a novel solid beryllium holder was designed. The performance of the crystal was verified using offline tests, and the integrated system was tested using experiments on the Z pulsed power accelerator.

13.
Obes Rev ; 17(9): 795-809, 2016 09.
Article in English | MEDLINE | ID: mdl-27272117

ABSTRACT

Bariatric surgery is currently the most effective treatment for obesity. Not only do these types of surgeries produce significant weight loss but also they improve insulin sensitivity and whole body metabolic function. The aim of this review is to explore how altered physiology of adipose tissue may contribute to the potent metabolic effects of some of these procedures. This includes specific effects on various fat depots, the function of individual adipocytes and the interaction between adipose tissue and other key metabolic tissues. Besides a dramatic loss of fat mass, bariatric surgery shifts the distribution of fat from visceral to the subcutaneous compartment favoring metabolic improvement. The sensitivity towards lipolysis controlled by insulin and catecholamines is improved, adipokine secretion is altered and local adipose inflammation as well as systemic inflammatory markers decreases. Some of these changes have been shown to be weight loss independent, and novel hypothesis for these effects includes include changes in bile acid metabolism, gut microbiota and central regulation of metabolism. In conclusion bariatric surgery is capable of improving aspects of adipose tissue function and do so in some cases in ways that are not entirely explained by the potent effect of surgery. © 2016 World Obesity.


Subject(s)
Adipose Tissue/physiology , Bariatric Surgery , Obesity/surgery , Adipocytes/metabolism , Adipokines/blood , Adipokines/metabolism , Animals , Catecholamines/blood , Disease Models, Animal , Humans , Inflammation , Insulin/blood , Insulin Resistance
14.
Int J Obes (Lond) ; 39(8): 1310-8, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25869599

ABSTRACT

BACKGROUND/OBJECTIVES: Mounting evidence supports a link between circadian disruption and metabolic disease. Humans with circadian disruption (for example, night-shift workers) have an increased risk of obesity and cardiometabolic diseases compared with the non-disrupted population. However, it is unclear whether the obesity and obesity-related disorders associated with circadian disruption respond to therapeutic treatments as well as individuals with other types of obesity. SUBJECTS/METHODS: Here, we test the effectiveness of the commonly used bariatric surgical procedure, Vertical Sleeve Gastrectomy (VSG), in mouse models of genetic and environmental circadian disruption. RESULTS: VSG led to a reduction in body weight and fat mass in both Clock(Δ19) mutant and constant-light mouse models (P<0.05), resulting in an overall metabolic improvement independent of circadian disruption. Interestingly, the decrease in body weight occurred without altering diurnal feeding or activity patterns (P>0.05). Within circadian-disrupted models, VSG also led to improved glucose tolerance and lipid handling (P<0.05). CONCLUSIONS: Together these data demonstrate that VSG is an effective treatment for the obesity associated with circadian disruption, and that the potent effects of bariatric surgery are orthogonal to circadian biology. However, as the effects of bariatric surgery are independent of circadian disruption, VSG cannot be considered a cure for circadian disruption. These data have important implications for circadian-disrupted obese patients. Moreover, these results reveal new information about the metabolic pathways governing the effects of bariatric surgery as well as of circadian disruption.


Subject(s)
Gastrectomy , Obesity/metabolism , Sleep Deprivation/metabolism , Animals , Circadian Rhythm , Disease Models, Animal , Energy Metabolism , Mice , Sleep Deprivation/physiopathology , Weight Loss
15.
Int J Obes (Lond) ; 38(2): 192-7, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23736358

ABSTRACT

BACKGROUND: Obesity has a complicated metabolic pathology, and defining the underlying mechanisms of obesity requires integrative studies with molecular end points. Real-time quantitative PCR (RT-qPCR) is a powerful tool that has been widely utilized. However, the importance of using carefully validated reference genes in RT-qPCR seems to have been overlooked in obesity-related research. The objective of this study was to select a set of reference genes with stable expressions to be used for RT-qPCR normalization in rats under fasted vs re-fed and chow vs high-fat diet (HFD) conditions. DESIGN: Male long-Evans rats were treated under four conditions: chow/fasted, chow/re-fed, HFD/fasted and HFD/re-fed. Expression stabilities of 13 candidate reference genes were evaluated in the rat hypothalamus, duodenum, jejunum and ileum using the ReFinder software program. The optimal number of reference genes needed for RT-qPCR analyses was determined using geNorm. RESULTS: Using geNorm analysis, we found that it was sufficient to use the two most stably expressed genes as references in RT-qPCR analyses for each tissue under specific experimental conditions. B2M and RPLP0 in the hypothalamus, RPS18 and HMBS in the duodenum, RPLP2 and RPLP0 in the jejunum and RPS18 and YWHAZ in the ileum were the most suitable pairs for a normalization study when the four aforementioned experimental conditions were considered. CONCLUSIONS: Our study demonstrates that gene expression levels of reference genes commonly used in obesity-related studies, such as ACTB or RPS18, are altered by changes in acute or chronic energy status. These findings underline the importance of using reference genes that are stable in expression across experimental conditions when studying the rat hypothalamus and intestine, because these tissues have an integral role in the regulation of energy homeostasis. It is our hope that this study will raise awareness among obesity researchers on the essential need for reference gene validation in gene expression studies.


Subject(s)
Hypothalamus/metabolism , Intestinal Mucosa/metabolism , Obesity/genetics , Ribosomal Proteins/metabolism , Animals , Diet, High-Fat , Fasting , Gene Expression Profiling , Genetic Markers , Male , Obesity/metabolism , Rats , Rats, Long-Evans , Real-Time Polymerase Chain Reaction , Ribosomal Proteins/genetics
16.
Neurogastroenterol Motil ; 25(8): 700-5, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23663526

ABSTRACT

BACKGROUND: Increases in L-cell release of GLP-1 are proposed to serve as a negative feedback signal for postprandial changes in gastric emptying and/or motility. Previous ex vivo data suggests that direct electrical stimulation (E-stim) of ileal segments stimulates secretion of GLP-1. This suggests potential feed-forward increases in GLP-1 driven by intestinal neuronal and/or motor activity. METHODS: To determine if E-stim could increase GLP-1 levels in an in vivo setting, we administered E-stim and nutrients to male Long- Evans rats (300-350 g) under general anesthesia. KEY RESULTS: Nutrient infusion into the duodenum or ileum significantly increased plasma GLP-1 levels, but E-stim applied to these locations did not (P < 0.05). However, the combination of E-stim and nutrient infusion, in either the ileum or duodenum, significantly increased plasma GLP-1 when compared to nutrient infusion alone (P < 0.05), and this effect was not blocked by either norepinephrine or atropine. To test the impact of intestinal motor activity, the effect of extra-luminal mechanical stimulation (M-stim) on GLP-1 levels was assessed. In the duodenum, but not the ileum, M-stim plus nutrient infusion significantly increased GLP-1 over nutrient infusion or M-stim alone (P < 0.05). CONCLUSIONS & INFERENCES: Thus, both E- and M-stim of the duodenum, but only E-stim of the ileum augmented nutrient-stimulated GLP-1 release. These data demonstrate that factors beyond enteral nutrients could contribute to the regulation of GLP-1 secretion.


Subject(s)
Duodenum/metabolism , Food , Glucagon-Like Peptide 1/metabolism , Ileum/metabolism , Animals , Electric Stimulation/methods , Glucagon-Like Peptide 1/blood , Male , Rats , Rats, Long-Evans
17.
Int J Obes (Lond) ; 37(2): 288-95, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22334194

ABSTRACT

OBJECTIVE: Diets high in fat are implicated in the development and maintenance of obesity, and obese individuals display greater preferences for high-fat foods than do their lean counterparts. Weight-reduction bariatric surgery is associated with changes in food choice. In particular, after Roux-en-Y gastric bypass (RYGB), humans and rodents select or prefer foods that are lower in fat content. We asked whether a bariatric surgical procedure limited to the stomach, vertical sleeve gastrectomy (VSG), causes a similar reduction of fat intake/preference. RESEARCH DESIGN AND METHODS: Rats received VSG or Sham surgery or remained surgically naïve, and were assessed for food preference using three diet-choice paradigms. Using progressive-ratio (PR) and conditioned taste aversion paradigms, we further asked whether surgically induced changes in food choice are secondary to changes in the reward value of food and/or to the formation of a food aversion. Finally, food choice was compared between VSG- and RYGB-operated rats. RESULTS: VSG rats decreased their intake of dietary fat, and shifted their preference toward lower caloric-density foods. This change in food choice was not associated with changes in motivated responding on a PR schedule for either a fat or a carbohydrate food reinforcer. When VSG and RYGB were compared directly, both procedures caused comparable changes in food choice. The conditioned taste aversion paradigm revealed that VSG rats form an aversion to an intra-gastric oil administration whereas RYGB rats do not. CONCLUSIONS: VSG and RYGB, two anatomically distinct bariatric procedures, produce similar changes in food choice.


Subject(s)
Dietary Fats/metabolism , Food Preferences , Gastric Bypass , Gastroplasty , Obesity/surgery , Animals , Body Weight , Choice Behavior , Energy Metabolism , Male , Physical Conditioning, Animal , Rats , Rats, Long-Evans , Reward , Taste
18.
Nutr Diabetes ; 2: e27, 2012 Feb 13.
Article in English | MEDLINE | ID: mdl-23169552

ABSTRACT

OBJECTIVES: Because females have blunted counterregulatory responses to hypoglycemia relative to males, we hypothesized that females would have greater sensitivity to changes in lipid availability. DESIGN AND SUBJECTS: To assess this, we examined the feeding response to glucoprivation (2-deoxyglucose; 2DG) and lipoprivation (mercaptoacetate; MA) in age-matched male and female Long-Evans rats. RESULTS: Males versus females had significantly greater food intake after 250 mg kg(-1) of 2DG, but there were no sex differences with the 750 mg kg(-1) dose of 2DG. Glucose responses to 250 mg kg(-1) of 2DG were also significantly greater in males versus females. In contrast, females had a significant increase in food intake with all doses of MA versus saline, and had significantly greater food intake compared with males at the lowest and highest doses of MA with a trend towards significance with the intermediate dose. To determine whether estradiol (E2) is the mechanism underlying this sexual dimorphism, ovariectomized females were injected with vehicle or 2 µg of E2 every fourth day to mimic the variations in across the estrous cycle. Ovariectomized females significantly increased feeding and glucose after 250 mg kg(-1) of 2DG over intact females and E2 had no effect on these responses. Although the feeding response to 2DG was not different, the glucose response to 2DG was still significantly greater in males versus ovariectomies females. However, ovariectomized females also did not increase food intake after MA, regardless of E2 treatment. CONCLUSIONS: These data collectively suggest that males are relatively more sensitive to glucose deprivation and females are relatively more sensitive to lipid deprivation. Further, these data rule out a role for cyclic changes in E2 in these sex differences.

19.
Int J Obes (Lond) ; 35 Suppl 3: S45-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21912388

ABSTRACT

Behavioral and pharmaceutical intervention to treat obesity and its comorbidities typically results in only a 5-10% weight loss. Thus, bariatric surgery is the most effective obesity treatment with some surgeries resulting in 30% sustained weight loss. Although this degree of weight loss has profound metabolic impact, these surgeries seem to have metabolic effects that are independent of weight loss. In support of this is the clinical literature showing rapid resolution of Type 2 diabetes mellitus (T2DM) that occurs before significant weight loss. To gain a complete understanding of the weight loss-independent effects of bariatric surgery, animal models have been developed. These are becoming more widely implemented and allow the use of pair-fed or weight-matched sham-operated controls in order to gain mechanistic insights into the mode of action of bariatric surgery. Increases in anorectic gut hormones, such as glucagon-like peptide-1 and peptide YY, or decreases in the orexigenic hormone ghrelin have been seen and are implicated as mediators of weight loss-independent actions of bariatric surgery. Changes in nutrient processing and sensing may also have a mechanistic role that is independent of, or that regulates, gut hormone responses to these surgeries. Ultimately, the hope is that understanding the mechanisms of bariatric surgeries will aid in the development of less invasive surgeries or pharmacological therapies that are more specifically, and perhaps individually, targeted at weight loss and/or resolution of T2DM.


Subject(s)
Diabetes Mellitus, Type 2/surgery , Gastric Bypass , Gastrointestinal Hormones/metabolism , Malabsorption Syndromes/prevention & control , Weight Loss , Animals , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/metabolism , Glucagon-Like Peptide 1/metabolism , Humans , Malabsorption Syndromes/etiology , Peptide YY/metabolism
20.
Neotrop. entomol ; 37(6): 739-740, Nov.-Dec. 2008. mapas
Article in English | LILACS | ID: lil-507035

ABSTRACT

The presence of the red palm mite, Raoiella indica Hirst is recorded for the first time in South America. High populations and severe damages caused by this new invasive mite were found on coconut and banana leaves in Sucre (10° 27' 47" N and 64°10' 38" W) and Monagas (9º46'60" N and 63º12'0" W) states in northeastern Venezuela.


Se registra la presencia de Raoiella indica Hirst por primera vez en Sur América. Altas poblaciones y daños severos causados por esta nueva especie invasiva fueron encontrados en hojas de coco y banana en los estados nororientales de Venezuela, Sucre (10° 27' 47" N y 64°10' 38" W) y Monagas (9º46'60" N y 63º12'0" W).


Subject(s)
Animals , Mites , Cocos/parasitology , Musa/parasitology , Venezuela
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