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1.
J Hepatol ; 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39002641

RESUMEN

BACKGROUND & AIMS: This was a randomized, double-blind, placebo-controlled study to assess the effects of pemvidutide, a glucagon-like peptide-1 (GLP-1)/glucagon dual receptor agonist, on liver fat content (LFC) in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD). METHODS: Patients with a BMI ≥28.0 kg/m2 and LFC ≥10% by magnetic resonance imaging-proton density fat fraction were randomized 1:1:1:1 to pemvidutide at 1.2 mg, 1.8 mg, or 2.4 mg, or placebo administered subcutaneously once weekly for 12 weeks. Participants were stratified according to a diagnosis of type 2 diabetes mellitus. The primary efficacy endpoint was relative reduction (%) from baseline in LFC after 12 weeks of treatment. RESULTS: Ninety-four patients were randomized and dosed. Median baseline BMI and LFC across the study population were 36.2 kg/m2 and 20.6%; 29% of patients had type 2 diabetes mellitus. At week 12, relative reductions in LFC from baseline were 46.6% (95% CI -63.7 to -29.6), 68.5% (95% CI -84.4 to -52.5), and 57.1% (95% CI -76.1 to -38.1) for the pemvidutide 1.2 mg, 1.8 mg, and 2.4 mg groups, respectively, vs. 4.4% (95% CI -20.2 to 11.3) for the placebo group (p <0.001 vs. placebo, all treatment groups), with 94.4% and 72.2% of patients achieving 30% and 50% reductions in LFC and 55.6% achieving normalization (≤5% LFC) at the 1.8 mg dose. Maximal responses for weight loss (-4.3%; p <0.001), alanine aminotransferase (-13.8 IU/L; p = 0.029), and corrected cT1 (-75.9 ms; p = 0.002) were all observed at the 1.8 mg dose. Pemvidutide was well-tolerated at all doses with no severe or serious adverse events. CONCLUSIONS: In patients with MASLD, weekly pemvidutide treatment yielded significant reductions in LFC, markers of hepatic inflammation, and body weight compared to placebo. IMPACT AND IMPLICATIONS: Metabolic dysfunction-associated steatotic liver disease, and its progressive form steatohepatitis, are strongly associated with overweight/obesity and it is believed that the excess liver fat associated with obesity is an important driver of these diseases. Glucagon-like peptide-1 receptor (GLP-1R) agonists elicit weight loss through centrally and peripherally mediated effects on appetite. Unlike GLP-1R agonists, glucagon receptor agonists act directly on the liver to stimulate fatty acid oxidation and inhibit lipogenesis, potentially providing a more potent mechanism for liver fat content reduction than weight loss alone. This study demonstrated the ability of once-weekly treatment with pemvidutide, a dual GLP-1R/glucagon receptor agonist, to significantly reduce liver fat content, hepatic inflammatory activity, and body weight, suggesting that pemvidutide may be an effective treatment for both metabolic dysfunction-associated steatohepatitis and obesity. CLINICAL TRIAL NUMBER: NCT05006885.

2.
Int J Mol Sci ; 24(8)2023 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-37108435

RESUMEN

This study describes, to some extent, the VCC contribution as an early stimulation of the macrophage lineage. Regarding the onset of the innate immune response caused by infection, the ß form of IL-1 is the most important interleukin involved in the onset of the inflammatory innate response. Activated macrophages treated in vitro with VCC induced the activation of the MAPK signaling pathway in a one-hour period, with the activation of transcriptional regulators for a surviving and pro-inflammatory response, suggesting an explanation inspired and supported by the inflammasome physiology. The mechanism of IL-1ß production induced by VCC has been gracefully outlined in murine models, using bacterial knockdown mutants and purified molecules; nevertheless, the knowledge of this mechanism in the human immune system is still under study. This work shows the soluble form of 65 kDa of the Vibrio cholerae cytotoxin (also known as hemolysin), as it is secreted by the bacteria, inducing the production of IL-1ß in the human macrophage cell line THP-1. The mechanism involves triggering the early activation of the signaling pathway MAPKs pERK and p38, with the subsequent activation of (p50) NF-κB and AP-1 (cJun and cFos), determined by real-time quantitation. The evidence shown here supports that the monomeric soluble form of the VCC in the macrophage acts as a modulator of the innate immune response, which is consistent with the assembly of the NLRP3 inflammasome actively releasing IL-1ß.


Asunto(s)
FN-kappa B , Vibrio cholerae , Humanos , Animales , Ratones , FN-kappa B/metabolismo , Factor de Transcripción AP-1/metabolismo , Inflamasomas/metabolismo , Vibrio cholerae/metabolismo , Activación Transcripcional , Citotoxinas/farmacología , Transducción de Señal , Macrófagos/metabolismo , Células THP-1 , Interleucina-1beta/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo
3.
Environ Manage ; 71(3): 565-586, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35939089

RESUMEN

Analyzing the effect of individual participants on collaborative governance processes in environmental management has been elusive due to lack of theoretical frameworks and data limitations. This study uses pattern matching to contrast identity theory with original data from 7 individuals participating in waste management and urban agriculture collaboration in Florianópolis, Brazil. What started as a self-organized initiative to manage an environmental problem, due to precarious waste management services, was scaled up to a citywide policy. Findings demonstrate that as the collaboration evolved over time, individual participants in municipal government transitioned between roles, organizations, and departments which affected their influence on the collaboration according to two transition styles: integrators (overlapping different roles) and segmenters (aligning roles with contexts without ambiguity). While the integrator-style participants were key to increasing sectoral diversity during the activation stage of the collaboration to produce innovative actions, segmenters contributed to formalizing the collaboration with appropriate institutional designs. However, the success of the collaboration after the institutionalization stage depended on the individual transition style and the power of municipal agents to have agency for influencing the collaboration. These findings have implications for adapting collaborative settings to respond to contextual changes that involve urban environmental issues.


Asunto(s)
Conservación de los Recursos Naturales , Administración de Residuos , Humanos , Organizaciones , Gobierno Local , Brasil
4.
Gastroenterology ; 161(5): 1475-1486, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34310978

RESUMEN

BACKGROUND & AIMS: Increased de novo lipogenesis creates excess intrahepatic fat and lipotoxins, propagating liver damage in nonalcoholic steatohepatitis. TVB-2640, a fatty acid synthase inhibitor, was designed to reduce excess liver fat and directly inhibit inflammatory and fibrogenic pathways. We assessed the safety and efficacy of TVB-2640 in patients with nonalcoholic steatohepatitis in the United States. METHODS: 3V2640-CLIN-005 (FASCINATE-1) was a randomized, placebo-controlled, single-blind study at 10 US sites. Adults with ≥8% liver fat, assessed by magnetic resonance imaging proton density fat fraction, and evidence of liver fibrosis by magnetic resonance elastography ≥2.5 kPa or liver biopsy were eligible. Ninety-nine patients were randomized to receive placebo or 25 mg or 50 mg of TVB-2640 (orally, once-daily for 12 weeks). The primary end points of this study were safety and relative change in liver fat after treatment. RESULTS: Liver fat increased in the placebo cohort by 4.5% relative to baseline; in contrast TVB-2640 reduced liver fat by 9.6% in the 25-mg cohort (n = 30; least squares mean: -15.5%; 95% confidence interval, -31.3 to -0.23; P = .053), and 28.1% in the 50-mg cohort (n = 28; least squares mean: -28.0%; 95% confidence interval, -44.5 to -11.6; P = .001). Eleven percent of patients in the placebo group achieved a ≥30% relative reduction of liver fat compared to 23% in the 25-mg group, and 61% in the 50-mg group (P < .001). Secondary analyses showed improvements of metabolic, pro-inflammatory and fibrotic markers. TVB-2640 was well tolerated; adverse events were mostly mild and balanced among the groups. CONCLUSIONS: TVB-2640 significantly reduced liver fat and improved biochemical, inflammatory, and fibrotic biomarkers after 12 weeks, in a dose-dependent manner in patients with nonalcoholic steatohepatitis. ClinicalTrials.gov, Number NCT03938246.


Asunto(s)
Inhibidores Enzimáticos/uso terapéutico , Acido Graso Sintasa Tipo I/antagonistas & inhibidores , Lipogénesis/efectos de los fármacos , Cirrosis Hepática/tratamiento farmacológico , Hígado/efectos de los fármacos , Nitrilos/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Piperidinas/uso terapéutico , Triazoles/uso terapéutico , Adulto , Biomarcadores/sangre , Inhibidores Enzimáticos/efectos adversos , Acido Graso Sintasa Tipo I/metabolismo , Femenino , Humanos , Lípidos/sangre , Hígado/diagnóstico por imagen , Hígado/enzimología , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/enzimología , Masculino , Persona de Mediana Edad , Nitrilos/efectos adversos , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Enfermedad del Hígado Graso no Alcohólico/enzimología , Piperidinas/efectos adversos , Método Simple Ciego , Factores de Tiempo , Resultado del Tratamiento , Triazoles/efectos adversos , Estados Unidos
5.
J Viral Hepat ; 28(11): 1635-1642, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34448313

RESUMEN

Sustained virologic response at posttreatment Week 12 (SVR12) is the widely accepted efficacy endpoint for direct-acting antiviral agents. Those with hepatitis C virus (HCV) are presenting younger with milder liver disease, potentially reducing need for long-term liver posttreatment monitoring. This analysis aimed to determine the positive predictive value (PPV) of SVR at posttreatment Week 4 (SVR4) for achieving SVR12 in patients with HCV, without cirrhosis or with compensated cirrhosis, receiving glecaprevir/pibrentasvir (G/P) in clinical trials. An integrated dataset from 20 Phase 2 and 3 clinical trials of G/P was evaluated in patients with 8-, 12- or 16-week treatment duration consistent with the current label (label-consistent group), and in all patients regardless of treatment duration consistency with the current label (overall group). Sensitivity analyses handled missing data either by backward imputation or were excluded. SVR4 PPV, negative predictive value (NPV), sensitivity and specificity were calculated for achieving SVR12 in both groups, and by treatment duration in the label-consistent group. SVR was defined as HCV ribonucleic acid 99% in both groups regardless of treatment duration. Not achieving SVR4 had 100% NPV and sensitivity for all groups. SVR4 measure had 79.5% specificity for identifying patients who did not achieve SVR12. Across 20 Phase 2/3 clinical trials of G/P, SVR4 was highly predictive of SVR12. Long-term follow-up to confirm SVR may not be necessary for certain populations of patients with HCV.


Asunto(s)
Antivirales , Hepatitis C Crónica , Ácidos Aminoisobutíricos , Antivirales/uso terapéutico , Bencimidazoles , Ciclopropanos , Genotipo , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Humanos , Lactamas Macrocíclicas , Leucina/análogos & derivados , Valor Predictivo de las Pruebas , Prolina/análogos & derivados , Pirrolidinas , Quinoxalinas/uso terapéutico , Sulfonamidas , Respuesta Virológica Sostenida , Resultado del Tratamiento
6.
Clin Gastroenterol Hepatol ; 18(11): 2544-2553.e6, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32621971

RESUMEN

BACKGROUND & AIMS: The direct-acting antiviral combination glecaprevir/pibrentasvir has been approved by the Food and Drug Administration for 8 weeks of treatment in treatment-naïve patients with hepatitis C virus (HCV) infection without cirrhosis or with compensated cirrhosis. We performed an integrated analysis of data from trials to evaluate the overall efficacy and safety of 8 weeks of glecaprevir/pibrentasvir in treatment-naïve patients without cirrhosis or with compensated cirrhosis. METHODS: We pooled data from 8 phase 2 or phase 3 trials of treatment-naïve patients with HCV genotype 1 to 6 infections, without cirrhosis or with compensated cirrhosis, who received 8 weeks of glecaprevir/pibrentasvir. RESULTS: Of 1248 patients, 343 (27%) had cirrhosis. Most patients were white (80%) and had HCV genotype 1 infection (47%) or genotype 3 infection (22%); the median age was 54 years. Overall rates of sustained virologic response at post-treatment week 12 were 97.6% (1218 of 1248) in the intention to treat (ITT) and 99.3% (1218 of 1226) in the modified ITT populations. When we excluded patients with genotype 3 infections with compensated cirrhosis (consistent with the European label), rates of sustained virologic response at post-treatment week 12 were 97.6% in the ITT and 99.4% in the modified ITT populations. Eight virologic failures (7 in patients without cirrhosis and 1 in a patient with cirrhosis) occurred in the ITT population. Virologic failure was not associated with markers of advanced liver disease or populations of interest (current alcohol use, opioid substitution therapy, history of injection-drug use, and severe renal impairment). Treatment-emergent adverse events (AEs) occurred in 58% of patients. The most frequent AEs (>10%) were headache (12%) and fatigue (12%). Serious AEs and AEs that led to glecaprevir/pibrentasvir discontinuation were reported in 2% and less than 1% of patients, respectively. CONCLUSIONS: In a pooled analysis of data from 8 trials, we found that 8 weeks of treatment with glecaprevir/pibrentasvir is efficacious and well tolerated in treatment-naïve patients with HCV genotype 1 to 6 infections, with or without cirrhosis.


Asunto(s)
Hepatitis C Crónica , Hepatitis C , Ácidos Aminoisobutíricos , Antivirales/efectos adversos , Bencimidazoles , Ciclopropanos , Genotipo , Hepacivirus/genética , Hepatitis C/tratamiento farmacológico , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/tratamiento farmacológico , Humanos , Lactamas Macrocíclicas , Leucina/análogos & derivados , Persona de Mediana Edad , Prolina/análogos & derivados , Pirrolidinas , Quinoxalinas , Sulfonamidas
7.
J Mol Cell Cardiol ; 132: 154-163, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31121182

RESUMEN

The CC chemokine 1 (CCL1, also called I-309 or TCA3) is a potent chemoattractant for leukocytes that plays an important role in inflammatory processes and diseases through binding to its receptor CCR8. Here, we investigated the role of the CCL1-CCR8 axis in atherosclerosis. We found increased expression of CCL1 in the aortas of atherosclerosis-prone fat-fed apolipoprotein E (Apoe)-null mice; moreover, in vitro flow chamber assays and in vivo intravital microscopy demonstrated an essential role for CCL1 in leukocyte recruitment. Mice doubly deficient for CCL1 and Apoe exhibited enhanced atherosclerosis in aorta, which was associated with reduced plasma levels of the anti-inflammatory interleukin 10, an increased splenocyte Th1/Th2 ratio, and a reduced regulatory T cell (Treg) content in aorta and spleen. Reduced Treg recruitment and aggravated atherosclerosis were also detected in the aortas of fat-fed low-density lipoprotein receptor-null mice treated with CCR8 blocking antibodies. These findings demonstrate that disruption of the CCL1-CCR8 axis promotes atherosclerosis by inhibiting interleukin 10 production and Treg recruitment and function.


Asunto(s)
Aterosclerosis/inmunología , Quimiocina CCL1/inmunología , Receptores CCR8/inmunología , Linfocitos T Reguladores/inmunología , Animales , Apolipoproteínas E/inmunología , Citocinas/inmunología , Inflamación/inmunología , Interleucina-10/inmunología , Leucocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células TH1/inmunología , Células Th2/inmunología
8.
Nature ; 502(7473): 672-6, 2013 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-24172979

RESUMEN

The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability. The increase in aridity predicted for the twenty-first century in many drylands worldwide may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. We find a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.


Asunto(s)
Clima Desértico , Desecación , Ecosistema , Geografía , Suelo/química , Silicatos de Aluminio/análisis , Biomasa , Carbono/análisis , Carbono/metabolismo , Ciclo del Carbono , Arcilla , Cambio Climático , Modelos Teóricos , Nitrógeno/análisis , Nitrógeno/metabolismo , Ciclo del Nitrógeno , Monoéster Fosfórico Hidrolasas/análisis , Monoéster Fosfórico Hidrolasas/metabolismo , Fósforo/análisis , Fósforo/metabolismo , Plantas/metabolismo
9.
Hepatology ; 65(6): 1803-1809, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28220512

RESUMEN

The optimal retreatment strategy for hepatitis C virus (HCV) genotype 1-infected patients who fail direct-acting antiviral (DAA)-based regimens remains unknown. In this phase 2, open-label study conducted at a single center in the United States, patients with HCV genotype 1 infection who previously failed to achieve sustained virological response (SVR) on a DAA-based regimen were randomized to receive treatment with a fixed-dose combination tablet of sofosbuvir-velpatasvir-voxilaprevir with or without ribavirin (RBV) for 12 weeks. Patients were stratified by their cirrhosis and past nonstructural protein (NS) 5A inhibitor exposure. The primary efficacy endpoint was the proportion of patients with SVR at 12 weeks after treatment (SVR12). SVR12 was achieved by 24 of 24 patients (100%; 95% confidence interval [CI], 86-100) receiving sofosbuvir-velpatasvir-voxilaprevir alone and 24 of 25 (96%; 95% CI, 80-100) receiving the same treatment with RBV. None of the patients discontinued sofosbuvir-velpatasvir-voxilaprevir therapy because of an adverse event (AE). The most commonly reported AEs with sofosbuvir-velpatasvir-voxilaprevir alone were diarrhea and bronchitis; and with sofosbuvir-velpatasvir-voxilaprevir plus RBV were fatigue, anemia, gastroenteritis, and nausea. CONCLUSION: A fixed-dose combination of sofosbuvir-velpatasvir-voxilaprevir was well tolerated and effective at achieving virological response in patients with HCV genotype 1 infection and past DAA treatment experience. (Hepatology 2017;65:1803-1809).


Asunto(s)
Carbamatos/administración & dosificación , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/genética , Compuestos Heterocíclicos de 4 o más Anillos/administración & dosificación , Compuestos Macrocíclicos/administración & dosificación , Ribavirina/administración & dosificación , Sofosbuvir/administración & dosificación , Sulfonamidas/administración & dosificación , Adulto , Anciano , Ácidos Aminoisobutíricos , Antivirales/administración & dosificación , Intervalos de Confianza , Ciclopropanos , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Genotipo , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepatitis C Crónica/fisiopatología , Humanos , Lactamas Macrocíclicas , Leucina/análogos & derivados , Masculino , Persona de Mediana Edad , Prolina/análogos & derivados , Estudios Prospectivos , Quinoxalinas , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Adulto Joven
10.
Hepatology ; 65(2): 439-450, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27770561

RESUMEN

Direct-acting antiviral agents (DAAs) represent the standard of care for patients with hepatitis C virus (HCV) infection. Combining DAAs with different mechanisms may allow for shorter treatment durations that are effective across multiple genotypes. The aim of the C-SWIFT study was to identify the minimum effective treatment duration across multiple genotypes. C-SWIFT was an open-label, single-center trial in treatment-naïve patients with chronic HCV genotype (GT)1 or 3 infection. All patients received elbasvir (EBR) 50 mg/grazoprevir (GZR) 100 mg with sofosbuvir (SOF) 400 mg for 4-12 weeks. Patients with GT1 infection who failed therapy were eligible for retreatment with EBR/GZR+SOF and ribavirin for 12 weeks. The primary efficacy endpoint was sustained virological response [SVR]12 (SVR of HCV RNA <15 IU/mL 12 weeks after the end of therapy). Rates of SVR12 were 32% (10 of 31) and 87% (26 of 30) in patients without cirrhosis with GT1 infection treated for 4 and 6 weeks and 80% (16 of 20) and 81% (17 of 21) in GT1-infected patients with cirrhosis treated for 6 and 8 weeks. Among GT3-infected patients without cirrhosis, SVR12 was 93% (14 of 15) and 100% (14 of 14) after 8 and 12 weeks. SVR12 in GT3-infected patients with cirrhosis was 83% (10 of 12) after 12 weeks of treatment. Twenty-three GT1-infected patients who relapsed following initial treatment completed retreatment; all achieved SVR12. In the initial treatment phase, there was one serious adverse event of pneumonia, which led to treatment discontinuation, and during retreatment, 1 patient discontinued ribavirin because of pruritus. CONCLUSION: Data from this study support the use of 8-week treatment regimens that maintain high efficacy, even for patients with HCV GT3 infection. Retreatment of patients who failed short-duration therapy was achieved through extended treatment duration and addition of ribavirin. (Hepatology 2017;65:439-450).


Asunto(s)
Benzofuranos/administración & dosificación , Hepatitis C/tratamiento farmacológico , Imidazoles/administración & dosificación , Quinoxalinas/administración & dosificación , Carga Viral/efectos de los fármacos , Adulto , Anciano , Amidas , Carbamatos , Intervalos de Confianza , Ciclopropanos , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepatitis C/diagnóstico , Hepatitis C Crónica/diagnóstico , Hepatitis C Crónica/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , ARN Viral/análisis , Sulfonamidas , Factores de Tiempo , Resultado del Tratamiento
11.
Environ Sci Technol ; 52(19): 10914-10922, 2018 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-30193457

RESUMEN

The plug-in electric vehicle (PEV) is regarded by many as a viable alternative to the internal combustion engine, so long as the radical technology is able to overcome technical and financial shortcomings that dictate consumer acceptance. States have instituted a variety of policies aimed at mitigating these shortcomings and simultaneously increasing consumer demand for PEV vehicles. Motivated by a limited body of literature on the effects of these policies, and a significant need for information about policy efficacy, in this study we evaluate the relationship between a suite of state-level policies and PEV registrations. Results reveal that tax credits for individuals, grants programs for charging infrastructure and PEV purchases, and incentives for state-owned PEVs fleets increase PEV registrations. The observed impact of grant incentives is mediated by charging capacity or, alternatively phrased, much of the influence of grants on registrations is through the channel of first improving the charging infrastructure within a state.


Asunto(s)
Electricidad , Política Pública , Comportamiento del Consumidor , Difusión , Humanos
12.
Proc Natl Acad Sci U S A ; 112(15): 4803-8, 2015 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-25825751

RESUMEN

Nearly all vertebrate cells have a single cilium protruding from their surface. This threadlike organelle, once considered vestigial, is now seen as a pivotal element for detection of extracellular signals that trigger crucial morphogenetic pathways. We recently proposed a role for Dido3, the main product of the death inducer-obliterator (dido) gene, in histone deacetylase 6 delivery to the primary cilium [Sánchez de Diego A, et al. (2014) Nat Commun 5:3500]. Here we used mice that express truncated forms of Dido proteins to determine the link with cilium-associated disorders. We describe dido mutant mice with high incidence of perinatal lethality and distinct neurodevelopmental, morphogenetic, and metabolic alterations. The anatomical abnormalities were related to brain and orofacial development, consistent with the known roles of primary cilia in brain patterning, hydrocephalus incidence, and cleft palate. Mutant mice that reached adulthood showed reduced life expectancy, brain malformations including hippocampus hypoplasia and agenesis of corpus callosum, as well as neuromuscular and behavioral alterations. These mice can be considered a model for the study of ciliopathies and provide information for assessing diagnosis and therapy of genetic disorders linked to the deregulation of primary cilia.


Asunto(s)
Encefalopatías/genética , Encéfalo/anomalías , Proteínas de Unión al ADN/genética , Mutación , Factores de Transcripción/genética , Acetilación , Animales , Animales Recién Nacidos , Western Blotting , Encefalopatías/mortalidad , Encefalopatías/fisiopatología , Fisura del Paladar/embriología , Fisura del Paladar/genética , Anomalías Craneofaciales/genética , Proteínas de Unión al ADN/metabolismo , Ratones , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Análisis de Supervivencia , Tasa de Supervivencia , Factores de Tiempo , Factores de Transcripción/metabolismo , Tubulina (Proteína)/metabolismo
13.
Proc Natl Acad Sci U S A ; 112(51): 15684-9, 2015 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-26647180

RESUMEN

Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and α-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands.


Asunto(s)
Cambio Climático , Ecosistema , Microbiología del Suelo , Concentración de Iones de Hidrógeno
14.
Hepatology ; 64(1): 301-2, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26991688

RESUMEN

Management of obesity and decompensated cirrhosis in those requiring liver transplantation (LT) is a challenging dilemma. Because of concerns for perioperative complications, many centers avoid transplant in those with a body mass index (BMI) greater than 40 kg/m(2) . Bariatric surgery is associated with increased risk attributable to complications of portal hypertension, including variceal rupture. Therefore, weight loss and LT options are limited. Several new classes of weight loss drugs are commercially available, including the anoretic, lorcaserin. This case illustrates the successful use of lorcaserin in a morbidly obese individual with decompensated cirrhosis evaluated for LT listing. (Hepatology 2016;64:301-302).


Asunto(s)
Benzazepinas/uso terapéutico , Obesidad Mórbida/tratamiento farmacológico , Humanos , Trasplante de Hígado , Masculino , Persona de Mediana Edad
15.
Ecology ; 97(6): 1593-604, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27459788

RESUMEN

Plant facilitation is now recognized as an important process in severe environments. However, there is still no agreement on how facilitation changes as conditions become increasingly severe. The classic stress gradient hypothesis (SGH) predicts a monotonic increase in facilitation, which rises in frequency as conditions approach the extreme end of the environmental gradient. However, few studies have evaluated the validity of the SGH at the community level, the level at which it was formulated. Moreover, few studies have tested the SGH at either extreme of the gradient, and very few have excluded the effect of livestock on community response to stress. In line with the SGH, we hypothesized that several spatial pattern summary statistics would change monotonically from the least to the most arid sites, indicating increasingly aggregated patterns. In this study, we performed an evaluation of the SGH both within communities of shrub species and across a large portion of the Atacama Desert, and we isolated the abiotic component of the SGH. Our environmental gradient covered an extreme aridity gradient (< 20-130 mm annual precipitation). To perform point pattern analysis, we established 13 sites with environmental conditions representing four distinct levels of this gradient. Further, we conducted species co-occurrence analyses at 19 sites along the gradient. Both sets of analyses showed stronger positive spatial associations among plants at the most extreme end of the gradient. This was true regardless of whether we included all individuals, only small individuals located around large ones, or individuals in species pairs. Moreover, species tended to show greater co-occurrence as environmental severity increased. This increase in aggregation in the plant community seems to correlate with an increase in the strength of positive interspecific interactions, rather than greater clustering within each species. These monotonic increases in species co-occurrence and spatial association in more severe environments are consistent with some of the predictions of SGH, and collectively these results suggest that as the climate becomes more arid, positive species pairs interactions tend to be prevalent in the community.


Asunto(s)
Clima Desértico , Ecosistema , Plantas/clasificación , Agua , Chile , Lluvia , Suelo/química
16.
Liver Transpl ; 21(6): 823-30, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25825070

RESUMEN

Recurrent hepatitis C virus (HCV) infection occurs universally in the allograft in the absence of effective antiviral therapy before liver transplantation (LT). Antiviral therapy with sofosbuvir and simeprevir has proven to be highly effective and well tolerated in the nontransplant setting for treatment of HCV genotype 1 infection; therefore, we sought to evaluate the efficacy and safety of this regimen in LT recipients with recurrent HCV infection. This was a retrospective analysis of a single-center treatment protocol of patients with HCV genotype 1 infection who received a 12-week combination regimen of sofosbuvir and simeprevir. Sixty-one patients (35 with genotype 1a and 26 with genotype 1b) completed treatment with simeprevir and sofosbuvir. Three patients received additional ribavirin. Laboratory data and clinical assessments performed at the baseline, on treatment, at the end of treatment, and 12 weeks after the completion of antiviral therapy [sustained virological response at 12 weeks (SVR12)] were analyzed. The median time after LT was 5.4 years [interquartile range (IQR), 1.9-8.4 years], and tacrolimus was the most commonly used immunosuppressive agent (80.3%). Overall, SVR12 was achieved in 93.4% [95% confidence interval (CI), 84%-97%] of LT recipients treated with 12 weeks of sofosbuvir and simeprevir. When they were analyzed according to the HCV subtype, LT recipients with genotype 1b had a 100% SVR12 rate (95% CI, 87%-100%), whereas SVR12 was 89% (95% CI, 74%-95%) for those with genotype 1a. Advanced fibrosis (METAVIR F3-F4) was associated with diminished antiviral efficacy in LT recipients with genotype 1a [SVR12, 67% (95% CI, 39%-86%); P = 0.01]. Overall, the incidence of adverse events (AEs) was low, and no severe AEs occurred during treatment. In conclusion, treatment with a 12-week regimen of sofosbuvir and simeprevir was well tolerated and resulted in a high SVR12 rate for LT recipients with recurrent HCV genotype 1 infection. Genotype 1a patients with advanced fibrosis of the allograft were more likely to relapse.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Complicaciones Posoperatorias/tratamiento farmacológico , Simeprevir/uso terapéutico , Sofosbuvir/uso terapéutico , Anciano , Aloinjertos/patología , Quimioterapia Combinada , Femenino , Fibrosis , Genotipo , Hepacivirus/genética , Hepatitis C/virología , Humanos , Hígado/patología , Trasplante de Hígado , Masculino , Persona de Mediana Edad , Recurrencia , Estudios Retrospectivos
17.
Neurocirugia (Astur) ; 26(5): 209-16, 2015.
Artículo en Español | MEDLINE | ID: mdl-25724620

RESUMEN

OBJECTIVE: To review childhood patients with choroid plexus tumors (CPT) who underwent surgery at Hospital Infantil Niño Jesús of Madrid since January 1981 to September 2014. MATERIAL AND METHODS: Registered charts were analyzed based on the epidemiology, tumor grade, clinical profile, location, dissemination characteristics, therapy, prognosis and complications. RESULTS: Seventeen childhood patients were recorded with CPT. Cases were distributed so that 9 cases were choroid plexus-papilloma (CPP) (52.9%), 2 cases atypical CPP (11.7%) and 6 cases choroid plexus-carcinoma (CPC) (35.2%). Age at diagnosis was less than 2 years in 14 of the 17 patients (82.3%) and the incidence was higher in males (82.3% of the cases). Gross total resection was performed in 16 patients (94.1%). Adjuvant treatment was used in 6 patients (all this cases with CPC) (35.2%). Two of the 17 patients died (11.7%), showing an incidence density of 0.01 deaths/year. CONCLUSIONS: Our case series is consistent with previous published in scientific literature regarding epidemiology, tumor grade, clinical presentation, radiological features and therapeutic approach. Gross total resection is considered the therapeutic gold standard for choroid plexus tumors. Chemotherapy and radiotherapy should be used as adjuvant treatment in CPC and recurrent or remaining atypical CPP.


Asunto(s)
Neoplasias del Plexo Coroideo/terapia , Papiloma del Plexo Coroideo/terapia , Neoplasias del Plexo Coroideo/diagnóstico , Terapia Combinada , Femenino , Humanos , Lactante , Masculino , Papiloma del Plexo Coroideo/diagnóstico , Pronóstico , España
18.
Perspect Plant Ecol Evol Syst ; 16(4): 164-173, 2014 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-25914604

RESUMEN

Plant-plant interactions are driven by environmental conditions, evolutionary relationships (ER) and the functional traits of the plants involved. However, studies addressing the relative importance of these drivers are rare, but crucial to improve our predictions of the effects of plant-plant interactions on plant communities and of how they respond to differing environmental conditions. To analyze the relative importance of -and interrelationships among- these factors as drivers of plant-plant interactions, we analyzed perennial plant co-occurrence at 106 dryland plant communities established across rainfall gradients in nine countries. We used structural equation modeling to disentangle the relationships between environmental conditions (aridity and soil fertility), functional traits extracted from the literature, and ER, and to assess their relative importance as drivers of the 929 pairwise plant-plant co-occurrence levels measured. Functional traits, specifically facilitated plants' height and nurse growth form, were of primary importance, and modulated the effect of the environment and ER on plant-plant interactions. Environmental conditions and ER were important mainly for those interactions involving woody and graminoid nurses, respectively. The relative importance of different plant-plant interaction drivers (ER, functional traits, and the environment) varied depending on the region considered, illustrating the difficulty of predicting the outcome of plant-plant interactions at broader spatial scales. In our global-scale study on drylands, plant-plant interactions were more strongly related to functional traits of the species involved than to the environmental variables considered. Thus, moving to a trait-based facilitation/competition approach help to predict that: 1) positive plant-plant interactions are more likely to occur for taller facilitated species in drylands, and 2) plant-plant interactions within woody-dominated ecosystems might be more sensitive to changing environmental conditions than those within grasslands. By providing insights on which species are likely to better perform beneath a given neighbour, our results will also help to succeed in restoration practices involving the use of nurse plants.

19.
Cells ; 13(2)2024 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-38247850

RESUMEN

The regulated formation and resolution of R-loops is a natural process in physiological gene expression. Defects in R-loop metabolism can lead to DNA replication stress, which is associated with a variety of diseases and, ultimately, with cancer. The proteins PARP1, DIDO3, and DHX9 are important players in R-loop regulation. We previously described the interaction between DIDO3 and DHX9. Here, we show that, in mouse embryonic fibroblasts, the three proteins are physically linked and dependent on PARP1 activity. The C-terminal truncation of DIDO3 leads to the impairment of this interaction; concomitantly, the cells show increased replication stress and senescence. DIDO3 truncation also renders the cells partially resistant to in vitro oncogenic transformation, an effect that can be reversed by immortalization. We propose that PARP1, DIDO3, and DHX9 proteins form a ternary complex that regulates R-loop metabolism, preventing DNA replication stress and subsequent senescence.


Asunto(s)
Replicación del ADN , Fibroblastos , Poli(ADP-Ribosa) Polimerasa-1 , Animales , Ratones , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/fisiología , ARN Helicasas DEAD-box/metabolismo , ARN Helicasas DEAD-box/fisiología , Senescencia Celular/genética , Carcinogénesis/genética
20.
Work ; 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39150840

RESUMEN

BACKGROUND: Musculoskeletal System Disorders (MSDs) are a group of injuries that represent common occupational diseases and should be evaluated for prevention purposes because an increase has been observed due to the repetitive movements performed in the industry. This research was carried out in a manufacturing industry where metal parts are manufactured, and workers experience back and wrist pain. OBJECTIVE: To prediagnose Musculoskeletal System Disorders (MSDs) and examine the relationship between temperature, demographic, and physiological factors in workers through predictive models, contributing to MSD prevention. METHODS: Information from 36 operators was used to obtain vital signs and somatometry data, and thermograms of their hands in the dorsal, palmar, and back areas were collected and analyzed to determine the relationship between temperature and demographic and physiological factors. RESULTS: The ergonomic evaluations proved that the operators were at high risk owing to repetitive movements and postures adopted during work. Eighty-six percent of cases with injuries were identified using infrared thermograms, proving their high level of effectiveness. When studying the relationship between temperature behavior during recovery from repetitive activities and demographic and physiological factors, it was determined that age, dominant hand, respiratory frequency, and BMI were the most significant. CONCLUSIONS: Nine regression models were obtained, with coefficients of determination between 0.17 and 0.71. The significant factors for worker injuries were age, dominant hand, respiratory rate, and BMI. However, the sample size and variability in work activities should be extended to generalize the findings.

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