Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 320
Filtrar
1.
Cell Death Discov ; 10(1): 372, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39174500

RESUMEN

Despite progress in breast cancer treatment, a significant portion of patients still relapse because of drug resistance. The involvement of microRNAs in cancer progression and chemotherapy response is well established. Therefore, this study aimed to elucidate the dysregulation of the microRNA-449 family (specifically, microRNA-449a, microRNA-449b-5p, and microRNA-449c-5p) and its impact on resistance to doxorubicin, a commonly used chemotherapeutic drug for the treatment of triple-negative breast cancer. We found that the microRNA-449 family is downregulated in triple-negative breast cancer and demonstrated its potential as a diagnostic biomarker. Besides, our findings indicate that the downregulation of the microRNA-449 family is mediated by the microRNAs-449/SIRT1-HDAC1 negative feedback loop. Moreover, it was found that the microRNA-449 family dysregulates the fatty acid metabolism by targeting ACSL4, which is a potential prognostic biomarker that mediates doxorubicin response through regulation of the drug extrusion pump ABCG2. Altogether, our results suggest that the microRNA-449 family might be a potential therapeutic target for the treatment of triple-negative breast cancer since it is implicated in doxorubicin response through ACSL4/ABCG2 axis regulation. Ultimately, our results also highlight the value of microRNAs-449 and ACSL4 as diagnostic and prognostic biomarkers in triple-negative breast cancer. Proposed model of miRNAs-449 downregulation in TNBC and doxorubicin response. MiRNAs-449 are downregulated in TNBC through a negative feedback loop with SIRT1 and HDAC1. Moreover, ACSL4 increases ABCG2 expression, thus diminishing the intracellular doxorubicin concentration and promoting doxorubicin resistance. MiRNAs-449 overexpression downregulates the ACSL4/ABCG2 axis and sensitizes doxorubicin-resistant cells to doxorubicin. Created with BioRender. TNBC: triple-negative breast cancer; DOX: doxorubicin; SIRT1: Sirtuin 1; HDAC1: Histone deacetylase 1; ACSL4: Acyl-CoA Synthetase Long-Chain Family Member 4; ABCG2: ATP-binding cassette superfamily G member 2.

2.
Sci Data ; 11(1): 892, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39152166

RESUMEN

Next-generation sequencing (NGS) has revolutionized genomic research by enabling high-throughput, cost-effective genome and transcriptome sequencing accelerating personalized medicine for complex diseases, including cancer. Whole genome/transcriptome sequencing (WGS/WTS) provides comprehensive insights, while targeted sequencing is more cost-effective and sensitive. In comparison to short-read sequencing, which still dominates the field due to high speed and cost-effectiveness, long-read sequencing can overcome alignment limitations and better discriminate similar sequences from alternative transcripts or repetitive regions. Hybrid sequencing combines the best strengths of different technologies for a more comprehensive view of genomic/transcriptomic variations. Understanding each technology's strengths and limitations is critical for translating cutting-edge technologies into clinical applications. In this study, we sequenced DNA and RNA libraries of reference samples using various targeted DNA and RNA panels and the whole transcriptome on both short-read and long-read platforms. This study design enables a comprehensive analysis of sequencing technologies, targeting protocols, and library preparation methods. Our expanded profiling landscape establishes a reference point for assessing current sequencing technologies, facilitating informed decision-making in genomic research and precision medicine.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , RNA-Seq , Análisis de Secuencia de ADN/métodos , Transcriptoma , Análisis de Secuencia de ARN , Medicina de Precisión
3.
Obes Surg ; 34(8): 2897-2906, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39001982

RESUMEN

INTRODUCTION: Metabolic and bariatric surgery (MBS) has experienced considerable growth, addressing the challenges of obesity and its complications. The lack of a comprehensive bibliometric analysis in Latin America motivates this study, highlighting the need to understand the evolution of research in this area and its impact on clinical decision-making and health policies. METHODOLOGY: A cross-sectional bibliometric study was carried out using the Scopus database. A structured search strategy was designed to identify articles related to bariatric surgery with authors affiliated with Latin American countries. Inclusion and exclusion criteria were applied, followed by a descriptive and bibliometric analysis of the scientific production found. RESULTS: A total of 3553 documents published between 1991 and 2024 were included. There was an annual growth of 11%, with an average age of documents of 7.5 years. A concentration was observed in some countries, notably Brazil, Mexico, and Chile. Although scientific output increased, the average number of citations per article showed a downward trend since 2003. DISCUSSION: Despite the growth in scientific production, the quality and relevance of research is questioned, especially given the decrease in the impact received. It highlights the lack of meaningful regional collaboration, which could limit the sharing of knowledge and resources. Questions are raised about gaps in research capacity and the economic and development implications are discussed. CONCLUSIONS: This study provides valuable information to strengthen future research in bariatric surgery in Latin America. It highlights the importance of promoting regional and international collaboration and improving research training in countries with less participation. Clinical intervention strategies can benefit from better understanding research trends and adopting evidence-based practices in a more informed manner.


Asunto(s)
Cirugía Bariátrica , Bibliometría , Cirugía Bariátrica/estadística & datos numéricos , Humanos , Estudios Transversales , América Latina , Investigación Biomédica , Obesidad Mórbida/cirugía
4.
Genome Biol Evol ; 16(5)2024 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-38788745

RESUMEN

Adaptation to extreme environments often involves the evolution of dramatic physiological changes. To better understand how organisms evolve these complex phenotypic changes, the repeatability and predictability of evolution, and possible constraints on adapting to an extreme environment, it is important to understand how adaptive variation has evolved. Poeciliid fishes represent a particularly fruitful study system for investigations of adaptation to extreme environments due to their repeated colonization of toxic hydrogen sulfide-rich springs across multiple species within the clade. Previous investigations have highlighted changes in the physiology and gene expression in specific species that are thought to facilitate adaptation to hydrogen sulfide-rich springs. However, the presence of adaptive nucleotide variation in coding and regulatory regions and the degree to which convergent evolution has shaped the genomic regions underpinning sulfide tolerance across taxa are unknown. By sampling across seven independent lineages in which nonsulfidic lineages have colonized and adapted to sulfide springs, we reveal signatures of shared evolutionary rate shifts across the genome. We found evidence of genes, promoters, and putative enhancer regions associated with both increased and decreased convergent evolutionary rate shifts in hydrogen sulfide-adapted lineages. Our analysis highlights convergent evolutionary rate shifts in sulfidic lineages associated with the modulation of endogenous hydrogen sulfide production and hydrogen sulfide detoxification. We also found that regions with shifted evolutionary rates in sulfide spring fishes more often exhibited convergent shifts in either the coding region or the regulatory sequence of a given gene, rather than both.


Asunto(s)
Adaptación Fisiológica , Evolución Molecular , Sulfuro de Hidrógeno , Animales , Sulfuro de Hidrógeno/metabolismo , Adaptación Fisiológica/genética , Secuencias Reguladoras de Ácidos Nucleicos , Filogenia , Poecilia/genética
5.
J Agric Food Chem ; 72(2): 1136-1145, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38183298

RESUMEN

Lignin is a very attractive and abundant biopolymer with the potential to be a biorenewable source of a large number of value-added organic chemicals. The current state-of-the-art methods fail to provide efficient valorization of lignin in this regard without the involvement of harsh conditions and auxiliary substances that compromise the overall sustainability of the proposed processes. Making an original approach from the set of mildest temperature and pressure conditions, this work identifies and explores the capacity of an aqueous solution of the nonvolatile ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) to partially depolymerize technical lignin (Indulin AT) by means of a treatment consisting in the simple contact at ambient temperature and pressure. Among a considerable number of valuable phenolic molecules that were identified in the resulting fluid, vanillin (yield of about 3 g/kg) and guaiacol (yield of about 1 g/kg) were the monophenolic compounds obtained in a higher concentration. The properties of the post-treatment solids recovered remain similar to those of the original lignin, although with a relatively lower abundance of guaiacyl units (in agreement with the generation of guaiacyl-derived phenolic molecules, such as vanillin and guaiacol). The assistance of the treatment with UV irradiation in the presence of nanoparticle catalysts does not lead to an improvement in the yields of phenolic compounds.


Asunto(s)
Benzaldehídos , Imidazoles , Líquidos Iónicos , Líquidos Iónicos/química , Lignina/química , Temperatura , Biomasa , Agua , Acetatos , Fenoles , Guayacol
6.
Sci Rep ; 13(1): 19511, 2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-37945656

RESUMEN

Large subduction earthquakes induce complex postseismic deformation, primarily driven by afterslip and viscoelastic relaxation, in addition to interplate relocking processes. However, these signals are intricately intertwined, posing challenges in determining the timing and nature of relocking. Here, we use six years of continuous GNSS measurements (2015-2021) to study the spatiotemporal evolution of afterslip, seismicity and locking after the 2015 Illapel earthquake ([Formula: see text] 8.3). Afterslip is inverted from postseismic displacements corrected for nonlinear viscoelastic relaxation modeled using a power-law rheology, and the distribution of locking is obtained from the linear trend of GNSS stations. Our results show that afterslip is mainly concentrated in two zones surrounding the region of largest coseismic slip. The accumulated afterslip (corresponding to [Formula: see text] 7.8) exceeds 1.5 m, with aftershocks mainly occurring at the boundaries of the afterslip patches. Our results reveal that the region experiencing the largest coseismic slip undergoes rapid relocking, exhibiting the behavior of a persistent velocity weakening asperity, with no observed aftershocks or afterslip within this region during the observed period. The rapid relocking of this asperity may explain the almost regular recurrence time of earthquakes in this region, as similar events occurred in 1880 and 1943.

7.
Sci Signal ; 16(811): eadh9399, 2023 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-37963195

RESUMEN

Systemic blood pressure is acutely controlled by total peripheral resistance as determined by the diameter of small arteries and arterioles, the contractility of which is regulated by endothelial cells lining the lumen of blood vessels. We investigated the physiological functions of the chloride (Cl-) channel TMEM16A in endothelial cells. TMEM16A channels generated calcium (Ca2+)-activated Cl- currents in endothelial cells from control (TMEM16Afl/fl) mice that were absent in those from mice with tamoxifen-inducible, endothelial cell-specific knockout of TMEM16A (TMEM16A ecKO). TMEM16A currents in endothelial cells were activated by the muscarinic receptor agonist acetylcholine and an agonist of the Ca2+ channel TRPV4, which localized in nanoscale proximity with TMEM16A as assessed by single-molecule localization imaging of endothelial cells. Acetylcholine stimulated TMEM16A currents by activating Ca2+ influx through surface TRPV4 channels without altering the nanoscale properties of TMEM16A and TRPV4 surface clusters or their colocalization. In pressurized arteries, activation of TMEM16A channels in endothelial cells induced by acetylcholine; TRPV4 channel stimulation; or intraluminal ATP, another vasodilator, produced hyperpolarization and dilation. Furthermore, deficiency of TMEM16A channels in endothelial cells resulted in increased systemic blood pressure in conscious mice. These data indicate that vasodilators stimulate TRPV4 channels, leading to Ca2+-dependent activation of nearby TMEM16A channels in endothelial cells to produce arterial hyperpolarization, vasodilation, and reduced blood pressure. Thus, TMEM16A is an anion channel in endothelial cells that regulates arterial contractility and blood pressure.


Asunto(s)
Canales Catiónicos TRPV , Vasodilatadores , Ratones , Animales , Vasodilatadores/farmacología , Presión Sanguínea/fisiología , Acetilcolina/farmacología , Células Endoteliales/metabolismo , Vasodilatación/fisiología , Cloruros/metabolismo , Calcio/metabolismo
8.
Cureus ; 15(10): e47628, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38021941

RESUMEN

Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of autoimmune pathologies often associated with occult malignancies. Glucocorticoids (GCs) represent the initial therapy to control symptoms and avoid complications. Immune checkpoint inhibitors (ICIs) have shifted the paradigm of cancer treatment. Nivolumab has become the first-line therapy in combination with chemotherapy for untreated, unresectable, non-HER-2-positive advanced gastroesophageal adenocarcinoma. The use of ICIs increases the risk of immune-related adverse events (irAEs), especially in patients with autoimmune diseases, and patients receiving steroids or immunosuppressants might be associated with poorer immunotherapy efficacy. We describe the case of a 49-year-old male who was diagnosed with paraneoplastic dermatomyositis (PDM) and gastroesophageal adenocarcinoma. He was started on prednisone taper, and concomitantly, he was started on chemotherapy with fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT), with administration of pegfilgrastim and dexamethasone during each cycle. Additionally, he was started on nivolumab. His course was complicated by worsening episodes of myopathies due to the immunotherapy, requiring adjustments to the prednisone taper. A positron emission tomography (PET) scan and repeat endoscopic ultrasonography with biopsy eight months after therapy initiation showed no major evidence of disease compared to prior. In our case, we exemplified the importance of multidisciplinary management for dosing and tapering of GCs and timing of ICI initiation, and we described the successful response to nivolumab in a patient with autoimmune disease concurrently receiving GCs.

9.
Toxics ; 11(10)2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37888671

RESUMEN

The contexts where there are mining and agriculture activities are potential sources of risk to human health due to contamination by chemical mixtures. These contexts are frequent in several Colombian regions. This study explored the potential association between the frequency of micronuclei and pesticides and elements in regions with ferronickel (Montelibano, Córdoba) and gold (Nechí, Antioquia) mining, and a closed native mercury mine (Aranzazu, Caldas), with an emphasis in the potential effect of selenium as a potential chelator. A cross-sectional study was carried out with 247 individuals. Sociodemographic, occupational, and toxicological variables were ascertained. Blood and urine samples were taken for pesticide analysis (5 organophosphates, 4 organochlorines, and 3 carbamates), 68 elements were quantified in hair, and micronuclei were quantified in lymphocytes. The mixtures of elements were grouped through principal component analysis. Prevalence ratios were estimated with robust variance Poisson regressions to explore associations. Interactions of selenium with toxic elements were explored. The highest concentrations of elements were in the active mines. The potentially most toxic chemical mixture was observed in the ferronickel mine. Pesticides were detected in a low proportion of participants (<2.5%), except paraoxon-methyl in blood (27.55%) in Montelibano and paraoxon-ethyl in blood (18.81%) in Aranzazu. The frequency of micronuclei was similar in the three mining contexts, with means between 4 to 7 (p = 0.1298). There was great heterogeneity in the exposure to pesticides and elements. The "hormetic effect" of selenium was described, in which, at low doses, it acts as a chelator in Montelibano and Aranzazu, and at high doses, it can enhance the toxic effects of other elements, maybe as in Nechí. Selenium can serve as a protective agent, but it requires adaptation to the available concentrations in each region to avoid its toxic effects.

10.
J Assist Reprod Genet ; 40(12): 2827-2834, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37755614

RESUMEN

PURPOSE: Ovarian decortication may affect ovarian function. We investigated the status of ovarian reserve after ovarian decortication plus chemotherapy at a stage of presumed stabilized recovery in women surviving cancer. METHODS: We searched our database for cancer survivors subjected to ovarian decortication and chemotherapy at least 3 years previously. Ovarian function was explored for levels of anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), and estradiol (E2), and menstrual pattern. RESULTS: Forty women (mean age 29.6 (SD, 6.1) years) were assessed at a mean of 4.7 (1.5) years after surgery. The predecortication levels of AMH and FSH changed at post-treatment from 2.2 (1.4) to 0.5 (1.3) ng/mL for AMH (p < 0.001) and from 4.7 (2.1) to 16.7 (21. 6) IU/L for FSH (p < 0.001). Amenorrhea consistent with primary ovarian insufficiency (POI) was diagnosed in 11 women, and normal ovarian reserve (AMH ≥ 1.0 ng/mL) was found in 4 of the 21 women who recovered regular cycles. Logistic regression confirmed AMH as an independent predictor of diminished ovarian reserve (OR = 0.24, 95% CI: 0.04-0.63, p = 0.025) and POI (OR = 0.11, 95% CI: 0.01-0.52, p = 0.027), and age was predictive of POI (OR = 1.36, 95% CI: 1.08-1.96, p = 0.035) and of irregular menstrual cycle (OR = 1.20, 95% CI: 1.03-1.46, p = 0.034). CONCLUSION: Ovarian decortication plus chemotherapy had a deleterious effect when assessed at a stage of stabilized ovarian recovery, but whether ovarian decortication had a specific impact cannot be revealed from our data.


Asunto(s)
Neoplasias , Reserva Ovárica , Femenino , Humanos , Adulto , Estudios Prospectivos , Ovario/cirugía , Estradiol/farmacología , Hormona Folículo Estimulante/farmacología , Amenorrea , Hormona Folículo Estimulante Humana/farmacología , Hormona Antimülleriana/farmacología
11.
Cureus ; 15(7): e41256, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37396146

RESUMEN

Large vessel vasculitides, such as Takayasu arteritis (TAK), are rare inflammatory conditions primarily affecting the aorta and its major branches. Its nonspecific symptoms and potential resemblance to atherosclerotic disease often pose diagnostic challenges. We present a case of a 57-year-old male with a history of extensive cardiovascular disease, initially attributed to atherosclerosis, resulting in several interventions, such as catheterization and major cardiac surgery, which didn't help improve his symptoms. Further evaluation revealed diffuse wall thickening of the aorta and its roots, as well as labs that suggested elevated inflammatory markers, comprehensive review of his chart and previous admissions, revealed that he had a well-documented aortitis for which he underwent a biopsy, which at the time was unrevealing. Furthermore, as he had significant aortic aneurysmal dilation, a thoracic cardiovascular surgeon remitted him to the rheumatology clinic, where he was placed on a prednisone taper and methotrexate regimen. Unfortunately, he redeveloped symptoms, and plans were made to transition to a tumor necrosis alpha (TNF-alpha) inhibitor. Our case highlights the importance of an accurate diagnosis and the prompt initiation of appropriate treatment in challenging cases of large vessel vasculitides. This case also underscores the need for heightened clinical awareness and interdisciplinary collaboration to ensure optimal patient care.

12.
Cureus ; 15(6): e40588, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37337554

RESUMEN

Antisynthetase syndrome is a complex autoimmune disorder, and one of the key criteria for diagnosis is the presence of myositis. Additionally, evidence of interstitial lung disease (ILD) is another important indicator for diagnosis; other clinical features associated with antisynthetase syndrome include arthritis, unexplained and persistent fever, Raynaud's phenomenon, and the presence of mechanic's hands. We report a case of a 36-year-old male who presented to the emergency department with shortness of breath and proximal muscle weakness in the setting of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection, as his inflammatory markers were elevated and he exhibited features suspicious for antisynthetase syndrome, he was started on methylprednisolone 40 mg intravenously every eight hours, and a myositis panel was checked. In addition, a chest computed tomography (CT) exhibited ground-glass opacities which were compatible with coronavirus disease 2019 (COVID-19). A magnetic resonance image (MRI) of both thighs was done, revealing significant swelling and confirming the suspicion of myositis as his muscle strength in his lower extremities took significant time to improve. As days passed, his muscle strength improved significantly and his creatine phosphatase kinase (CPK) values trended down, indicating that his myositis was improving as well. He was transitioned to oral prednisone 60 mg daily and was discharged home with a rheumatology follow-up to define long-term treatment. A myositis panel revealed anti-glycyl-transferRNA synthetase (EJ) autoantibody positivity and a diagnosis was established. Our case revealed how sometimes laboratory values do not necessarily correlate with disease severity and how we have to do a thorough history of present illness and physical exam to think about unusual diagnoses before putting laboratory data into context.

13.
bioRxiv ; 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37333248

RESUMEN

Endothelial cells (ECs) regulate vascular contractility to control regional organ blood flow and systemic blood pressure. Several cation channels are expressed in ECs which regulate arterial contractility. In contrast, the molecular identity and physiological functions of anion channels in ECs is unclear. Here, we generated tamoxifen-inducible, EC-specific TMEM16A knockout ( TMEM16A ecKO) mice to investigate the functional significance of this chloride (Cl - ) channel in the resistance vasculature. Our data demonstrate that TMEM16A channels generate calcium-activated Cl - currents in ECs of control ( TMEM16A fl/fl ) mice that are absent in ECs of TMEM16A ecKO mice. Acetylcholine (ACh), a muscarinic receptor agonist, and GSK101, a TRPV4 agonist, activate TMEM16A currents in ECs. Single molecule localization microscopy data indicate that surface TMEM16A and TRPV4 clusters locate in very close nanoscale proximity, with ∼18% exhibiting overlap in ECs. ACh stimulates TMEM16A currents by activating Ca 2+ influx through surface TRPV4 channels without altering the size or density of TMEM16A or TRPV4 surface clusters, their spatial proximity or colocalization. ACh-induced activation of TMEM16A channels in ECs produces hyperpolarization in pressurized arteries. ACh, GSK101 and intraluminal ATP, another vasodilator, all dilate pressurized arteries through TMEM16A channel activation in ECs. Furthermore, EC-specific knockout of TMEM16A channels elevates systemic blood pressure in conscious mice. In summary, these data indicate that vasodilators stimulate TRPV4 channels, leading to Ca 2+ -dependent activation of nearby TMEM16A channels in ECs to produce arterial hyperpolarization, vasodilation and a reduction in blood pressure. We identify TMEM16A as an anion channel present in ECs that regulates arterial contractility and blood pressure. One sentence summary: Vasodilators stimulate TRPV4 channels, leading to calcium-dependent activation of nearby TMEM16A channels in ECs to produce arterial hyperpolarization, vasodilation and a reduction in blood pressure.

14.
Microb Cell Fact ; 22(1): 99, 2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-37170263

RESUMEN

BACKGROUND: In research and production, reproducibility is a key factor, to meet high quality and safety standards and maintain productivity. For microbial fermentations, complex substrates and media components are often used. The complex media components can vary in composition, depending on the lot and manufacturing process. These variations can have an immense impact on the results of biological cultivations. The aim of this work was to investigate and characterize the influence of the complex media component yeast extract on cultivations of Azotobacter vinelandii under microaerobic conditions. Under these conditions, the organism produces the biopolymer alginate. The focus of the investigation was on the respiration activity, cell growth and alginate production. RESULTS: Yeast extracts from 6 different manufacturers and 2 different lots from one manufacturer were evaluated. Significant differences on respiratory activity, growth and production were observed. Concentration variations of three different yeast extracts showed that the performance of poorly performing yeast extracts can be improved by simply increasing their concentration. On the other hand, the results with well-performing yeast extracts seem to reach a saturation, when their concentration is increased. Cultivations with poorly performing yeast extract were supplemented with grouped amino acids, single amino acids and micro elements. Beneficial results were obtained with the supplementation of copper sulphate, cysteine or a combination of both. Furthermore, a correlation between the accumulated oxygen transfer and the final viscosity (as a key performance indicator), was established. CONCLUSION: The choice of yeast extract is crucial for A. vinelandii cultivations, to maintain reproducibility and comparability between cultivations. The proper use of specific yeast extracts allows the cultivation results to be specifically optimised. In addition, supplements can be applied to modify and improve the properties of the alginate. The results only scratch the surface of the underlying mechanisms, as they are not providing explanations on a molecular level. However, the findings show the potential of optimising media containing yeast extract for alginate production with A. vinelandii, as well as the potential of targeted supplementation of the media.


Asunto(s)
Alginatos , Aminoácidos , Alginatos/química , Reproducibilidad de los Resultados , Ácido Glucurónico/química , Ácido Glucurónico/metabolismo , Ácidos Hexurónicos/metabolismo
15.
Int J Biol Macromol ; 242(Pt 1): 124626, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37119884

RESUMEN

Fruit residues are attractive substrates for the production of bacterial polyhydroxyalkanoates due to the high contents of fermentable sugars and the fast, simple, and efficient pretreatment methods required. In this study, apple residues, mainly apple peel, were used as the sole carbon source in cultures of the bacterium Azotobacter vinelandii OP to produce poly-3-hydroxybutyrate (P3HB). Conversion from the residue to total sugars was highly effective, achieving conversions of up to 65.4 % w w-1 when using 1 % v v-1 sulfuric acid and 58.3 % w w-1 in the absence of acid (only water). The cultures were evaluated at the shake-flask scale and in 3-L bioreactors using a defined medium under nitrogen starvation conditions. The results showed the production of up to 3.94 g L-1 P3HB in a bioreactor, reaching an accumulation of 67.3 % w w-1 when using apple residues. For the PHB obtained from the cultures with apple residues, a melting point of 179.99 °C and a maximum degradation temperature of 274.64 °C were calculated. A P3HB production strategy is shown using easily hydrolysable fruit residues to achieve production yields comparable to those obtained with pure sugars under similar cultivation conditions.


Asunto(s)
Azotobacter vinelandii , Malus , Polihidroxialcanoatos , Azotobacter vinelandii/metabolismo , Malus/metabolismo , Reactores Biológicos/microbiología , Poliésteres/química , Hidroxibutiratos/química , Azúcares/metabolismo
16.
Front Endocrinol (Lausanne) ; 14: 1093376, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36967809

RESUMEN

Thermal homeostasis is a fundamental process in mammals, which allows the maintenance of a constant internal body temperature to ensure an efficient function of cells despite changes in ambient temperature. Increasing evidence has revealed the great impact of thermoregulation on energy homeostasis. Homeothermy requires a fine regulation of food intake, heat production, conservation and dissipation and energy expenditure. A great interest on this field of research has re-emerged following the discovery of thermogenic brown adipose tissue and browning of white fat in adult humans, with a potential clinical relevance on obesity and metabolic comorbidities. However, most of our knowledge comes from male animal models or men, which introduces unwanted biases on the findings. In this review, we discuss how differences in sex-dependent characteristics (anthropometry, body composition, hormonal regulation, and other sexual factors) influence numerous aspects of thermal regulation, which impact on energy homeostasis. Individuals of both sexes should be used in the experimental paradigms, considering the ovarian cycles and sexual hormonal regulation as influential factors in these studies. Only by collecting data in both sexes on molecular, functional, and clinical aspects, we will be able to establish in a rigorous way the real impact of thermoregulation on energy homeostasis, opening new avenues in the understanding and treatment of obesity and metabolic associated diseases.


Asunto(s)
Regulación de la Temperatura Corporal , Caracteres Sexuales , Animales , Masculino , Femenino , Humanos , Homeostasis , Obesidad/terapia , Mamíferos
17.
Acta Physiol (Oxf) ; 237(3): e13896, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36251565

RESUMEN

AIM: Physiological functions in mammals show circadian oscillations, synchronized by daily cycles of light and temperature. Central and peripheral clocks participate in this regulation. Since the ion channel TRPM8 is a critical cold sensor, we investigated its role in circadian function. METHODS: We used TRPM8 reporter mouse lines and TRPM8-deficient mice. mRNA levels were determined by in situ hybridization or RT-qPCR and protein levels by immunofluorescence. A telemetry system was used to measure core body temperature (Tc). RESULTS: TRPM8 is expressed in the retina, specifically in cholinergic amacrine interneurons and in a subset of melanopsin-positive ganglion cells which project to the central pacemaker, the suprachiasmatic nucleus (SCN) of the hypothalamus. TRPM8-positive fibres were also found innervating choroid and ciliary body vasculature, with a putative function in intraocular temperature, as shown in TRPM8-deficient mice. Interestingly, Trpm8-/- animals displayed increased expression of the clock gene Per2 and vasopressin (AVP) in the SCN, suggesting a regulatory role of TRPM8 on the central oscillator. Since SCN AVP neurons control body temperature, we studied Tc in driven and free-running conditions. TRPM8-deficiency increased the amplitude of Tc oscillations and, under dim constant light, induced a greater phase delay and instability of Tc rhythmicity. Finally, TRPM8-positive fibres innervate peripheral organs, like liver and white adipose tissue. Notably, Trpm8-/- mice displayed a dysregulated expression of Per2 mRNA in these metabolic tissues. CONCLUSION: Our findings support a function of TRPM8 as a temperature sensor involved in the regulation of central and peripheral clocks and the circadian control of Tc.


Asunto(s)
Ritmo Circadiano , Canales Catiónicos TRPM , Ratones , Animales , Ritmo Circadiano/fisiología , Temperatura Corporal/fisiología , Núcleo Supraquiasmático/metabolismo , Canales Iónicos/metabolismo , Mamíferos , ARN Mensajero/metabolismo , Canales Catiónicos TRPM/metabolismo
19.
ESC Heart Fail ; 9(4): 2189-2198, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-36255281

RESUMEN

AIMS: To describe the natural history of SARS-CoV-2 infection in patients with hypertrophic cardiomyopathy (HCM) compared with a control group and to identify predictors of adverse events. METHODS AND RESULTS: Three hundred and five patients [age 56.6 ± 16.9 years old, 191 (62.6%) male patients] with HCM and SARS-Cov-2 infection were enrolled. The control group consisted of 91 131 infected individuals. Endpoints were (i) SARS-CoV-2 related mortality and (ii) severe clinical course [death or intensive care unit (ICU) admission]. New onset of atrial fibrillation, ventricular arrhythmias, shock, stroke, and cardiac arrest were also recorded. Sixty-nine (22.9%) HCM patients were hospitalized for non-ICU level care, and 21 (7.0%) required ICU care. Seventeen (5.6%) died: eight (2.6%) of respiratory failure, four (1.3%) of heart failure, two (0.7%) suddenly, and three (1.0%) due to other SARS-CoV-2-related complications. Covariates associated with mortality in the multivariable were age {odds ratio (OR) per 10 year increase 2.25 [95% confidence interval (CI): 1.12-4.51], P = 0.0229}, baseline New York Heart Association class [OR per one-unit increase 4.01 (95%CI: 1.75-9.20), P = 0.0011], presence of left ventricular outflow tract obstruction [OR 5.59 (95%CI: 1.16-26.92), P = 0.0317], and left ventricular systolic impairment [OR 7.72 (95%CI: 1.20-49.79), P = 0.0316]. Controlling for age and sex and comparing HCM patients with a community-based SARS-CoV-2 cohort, the presence of HCM was associated with a borderline significant increased risk of mortality OR 1.70 (95%CI: 0.98-2.91, P = 0.0600). CONCLUSIONS: Over one-fourth of HCM patients infected with SARS-Cov-2 required hospitalization, including 6% in an ICU setting. Age and cardiac features related to HCM, including baseline functional class, left ventricular outflow tract obstruction, and systolic impairment, conveyed increased risk of mortality.


Asunto(s)
Fibrilación Atrial , COVID-19 , Cardiomiopatía Hipertrófica , Disfunción Ventricular Izquierda , Humanos , Masculino , Adulto , Persona de Mediana Edad , Anciano , Femenino , COVID-19/complicaciones , COVID-19/epidemiología , SARS-CoV-2 , Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/epidemiología , Sistema de Registros , Disfunción Ventricular Izquierda/complicaciones , Fibrilación Atrial/complicaciones
20.
3 Biotech ; 12(11): 304, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36276477

RESUMEN

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a polymer produced by Azotobacter vinelandii OP. In the bioreactor, PHBV production and its molar composition are affected by aeration rate. PHBV production by A. vinelandii OP was evaluated using extended batch cultures at different aeration rates, which determined different oxygen transfer rates (OTR) in the cultures. Under the conditions evaluated, PHBV with different 3-hydroxyvalerate (3HV) fractions were obtained. In the cultures with a low OTR (6.7 mmol L-1 h-1, at 0.3 vvm), a PHBV content of 38% w w-1 with 9.1 mol % 3HV was achieved. The maximum PHBV production (72% w w-1) was obtained at a high OTR (18.2 mmol L-1 h-1, at 1.0 vvm), both at 48 h. Thus, PHBV production increased in the bioreactor with an increased aeration rate, but not the 3HV fraction in the polymer chain. An OTR of 24.9 mmol L-1 h-1 (at 2.1 vvm) was the most suitable for improving the PHBV content (61% w w-1) and a high 3HV fraction of 20.8 mol % (at 48 h); and volumetric productivity (0.15 g L-1 h-1). The findings indicate that the extended batch culture at 2.1 vvm is the most adequate mode of cultivation to produce higher biomass and PHBV with a high 3HV fraction. Overall, the results have shown that the PHBV production and 3HV fraction could be affected by the aeration rate and the proposed approach could be applied to implement cultivation strategies to optimize PHBV production for different biotechnological applications.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA