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1.
Proc Biol Sci ; 291(2017): 20232857, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38378156

RESUMEN

The exceptional polymorphism observed within genes of the major histocompatibility complex (MHC), a core component of the vertebrate immune system, has long fascinated biologists. The highly polymorphic classical MHC class-I (MHC-I) genes are maintained by pathogen-mediated balancing selection (PMBS), as shown by many sites subject to positive selection, while the more monomorphic non-classical MHC-I genes show signatures of purifying selection. In line with PMBS, at any point in time, rare classical MHC alleles are more likely than common classical MHC alleles to confer a selective advantage in host-pathogen interactions. Combining genomic and expression data from the blood of wild house sparrows Passer domesticus, we found that only rare classical MHC-I alleles were highly expressed, while common classical MHC-I alleles were lowly expressed or not expressed. Moreover, highly expressed rare classical MHC-I alleles had more positively selected sites, indicating exposure to stronger PMBS, compared with lowly expressed classical alleles. As predicted, the level of expression was unrelated to allele frequency in the monomorphic non-classical MHC-I alleles. Going beyond previous studies, we offer a fine-scale view of selection on classical MHC-I genes in a wild population by revealing differences in the strength of PMBS according to allele frequency and expression level.


Asunto(s)
Complejo Mayor de Histocompatibilidad , Gorriones , Animales , Alelos , Complejo Mayor de Histocompatibilidad/genética , Gorriones/genética , Frecuencia de los Genes , Selección Genética , Variación Genética
2.
Cytokine ; 176: 156503, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38301358

RESUMEN

Orosomucoid, or alpha-1 acid glycoprotein (AGP), is a major acute-phase protein expressed in response to systemic injury and inflammation. AGP has been described as an inhibitor of neutrophil migration on sepsis, particularly its immunomodulation effects. AGP's biological functions in coronavirus disease 2019 (COVID-19) are not understood. We sought to investigate the role of AGP in severe COVID-19 infection patients and neutrophils infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Epidemiological data, AGP levels, and other laboratory parameters were measured in blood samples from 56 subjects hospitalized in the ICU with SARS-CoV-2 infection. To evaluate the role of AGP in NETosis in neutrophils, blood samples from health patients were collected, and neutrophils were separated and infected with SARS-CoV-2. Those neutrophils were treated with AGP or vehicle, and NETosis was analyzed by flow cytometry. AGP was upregulated in severe COVID-19 patients (p<0.05). AGP level was positively correlated with IL-6 and C-reactive protein (respectively, p=0.005, p=0.002) and negatively correlated with lactate (p=0.004). AGP treatment downregulated early and late NETosis (respectively, 35.7% and 43.5%) in neutrophils infected with SARS-CoV-2 and up-regulated IL-6 supernatant culture expression (p<0.0001). Our data showed increased AGP in COVID-19 infection and contributed to NETosis regulation and increased IL-6 production, possibly related to the Cytokine storm in COVID-19.


Asunto(s)
COVID-19 , Humanos , COVID-19/metabolismo , Neutrófilos/metabolismo , Orosomucoide/metabolismo , Orosomucoide/farmacología , SARS-CoV-2 , Interleucina-6/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Inmunoproteínas/metabolismo
3.
Clin Sci (Lond) ; 138(17): 1071-1087, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39136472

RESUMEN

Perivascular adipose tissue (PVAT) negatively regulates vascular muscle contraction. However, in the context of obesity, the PVAT releases vasoconstrictor substances that detrimentally affect vascular function. A pivotal player in this scenario is the peptide endothelin-1 (ET-1), which induces oxidative stress and disrupts vascular function. The present study postulates that obesity augments ET-1 production in the PVAT, decreases the function of the nuclear factor erythroid 2-related factor-2 (Nrf2) transcription factor, further increasing reactive oxygen species (ROS) generation, culminating in PVAT dysfunction. Male C57BL/6 mice were fed either a standard or a high-fat diet for 16 weeks. Mice were also treated with saline or a daily dose of 100 mg·kg-1 of the ETA and ETB receptor antagonist Bosentan, for 7 days. Vascular function was evaluated in thoracic aortic rings, with and without PVAT. Mechanistic studies utilized PVAT from all groups and cultured WT-1 mouse brown adipocytes. PVAT from obese mice exhibited increased ET-1 production, increased ECE1 and ETA gene expression, loss of the anticontractile effect, as well as increased ROS production, decreased Nrf2 activity, and downregulated expression of Nrf2-targeted antioxidant genes. PVAT of obese mice also exhibited increased expression of Tyr216-phosphorylated-GSK3ß and KEAP1, but not BACH1 - negative Nrf2 regulators. Bosentan treatment reversed all these effects. Similarly, ET-1 increased ROS generation and decreased Nrf2 activity in brown adipocytes, events mitigated by BQ123 (ETA receptor antagonist). These findings place ET-1 as a major contributor to PVAT dysfunction in obesity and highlight that pharmacological control of ET-1 effects restores PVAT's cardiovascular protective role.


Asunto(s)
Tejido Adiposo , Regulación hacia Abajo , Endotelina-1 , Ratones Endogámicos C57BL , Factor 2 Relacionado con NF-E2 , Obesidad , Especies Reactivas de Oxígeno , Animales , Endotelina-1/metabolismo , Obesidad/metabolismo , Obesidad/fisiopatología , Masculino , Tejido Adiposo/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Bosentán/farmacología , Dieta Alta en Grasa , Ratones , Estrés Oxidativo , Receptor de Endotelina A/metabolismo , Receptor de Endotelina A/genética , Enzimas Convertidoras de Endotelina/metabolismo , Aorta Torácica/metabolismo , Aorta Torácica/efectos de los fármacos , Aorta Torácica/fisiopatología
4.
Dent Traumatol ; 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38576382

RESUMEN

BACKGROUND/AIM: This study assessed the epidemiology of luxation injuries with or without dental fractures in patients attending the outpatient clinic of a Brazilian dental school over the past decade. MATERIAL AND METHODS: We reviewed clinical records from a specialized center for dental trauma care in Brazil, focusing on patients who experienced at least one traumatic dental injury (TDI) in a permanent tooth between 2012 and 2022. The extracted data included sex, age, etiology, time between trauma occurrence and the search for initial care, TDI classification, and the need for endodontic treatment. The statistical analysis involved Pearson's chi-squared and Fisher's exact tests at a 5% significance level. RESULTS: The 366 analyzed clinical records included 166 patients (350 teeth) with luxation injuries. Men (n = 102) showed a higher prevalence of luxation injuries than women (n = 64). Extrusive luxation prevailed (n = 99 patients and 208 teeth). Patients with luxation injuries sought care promptly after dental trauma incidents (p = .02) and demonstrated a higher incidence of endodontic treatment (p < .0001) than those without luxation injuries. Lateral luxation was notably associated with traffic accidents (p < .0001). The combination of luxation injuries and tooth fractures did not correlate with a higher need for endodontic treatment (p > .05). CONCLUSIONS: Age and trauma etiology seemed to have influenced the epidemiological profile of luxation injuries. Additionally, these injuries affected the time to seek initial care and the need for endodontic treatment.

5.
Am J Physiol Heart Circ Physiol ; 324(4): H417-H429, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36705993

RESUMEN

α-Adrenergic receptors are crucial regulators of vascular hemodynamics and essential pharmacological targets for cardiovascular diseases. With aging, there is an increase in sympathetic activation, which could contribute to the progression of aging-associated cardiovascular dysfunction, including stroke. Nevertheless, there is little information directly associating adrenergic receptor dysfunction in the blood vessels of aged females. This study determined the role of a-adrenergic receptors in carotid dysfunction of senescent female mice (accelerated-senescence prone, SAMP8), compared with a nonsenescent (accelerated-senescence prone, SAMR1). Vasoconstriction to phenylephrine (Phe) was markedly increased in common carotid artery of SAMP8 [area under the curve (AUC), 527 ± 53] compared with SAMR1 (AUC, 334 ± 30, P = 0.006). There were no changes in vascular responses to the vasoconstrictor agent U46619 or the vasodilators acetylcholine (ACh) and sodium nitroprusside (NPS). Hyperactivity to Phe in female SAMP8 was reduced by cyclooxygenase-1 and cyclooxygenase-2 inhibition and associated with augmented ratio of TXA2/PGI2 release (SAMR1, 1.1 ± 0.1 vs. SAMP8, 2.1 ± 0.3, P = 0.007). However, no changes in cyclooxygenase expression were seen in SAMP8 carotids. Selective α1A-receptor antagonism markedly reduced maximal contraction, whereas α1D antagonism induced a minor shift in Phe contraction in SAMP8 carotids. Ligand binding analysis revealed a threefold increase of α-adrenergic receptor density in smooth muscle cells (VSMCs) of SAMP8 vs. SAMR1. Phe rapidly increased intracellular calcium (Cai2+) in VSMCs via the α1A-receptor, with a higher peak in VSMCs from SAMP8. In conclusion, senescence intensifies vasoconstriction mediated by α1A-adrenergic signaling in the carotid of female mice by mechanisms involving increased Cai2+ and release of cyclooxygenase-derived prostanoids.NEW & NOTEWORTHY The present study provides evidence that senescence induces hyperreactivity of α1-adrenoceptor-mediated contraction of the common carotid. Impairment of α1-adrenoceptor responses is linked to increased Ca2+ influx and release of COX-derived vasoconstrictor prostanoids, contributing to carotid dysfunction in the murine model of female senescence (SAMP8). Increased reactivity of the common carotid artery during senescence may lead to morphological and functional changes in arteries of the cerebral microcirculation and contribute to cognitive decline in females. Because the elderly population is growing, elucidating the mechanisms of aging- and sex-associated vascular dysfunction is critical to better direct pharmacological and lifestyle interventions to prevent cardiovascular risk in both sexes.


Asunto(s)
Prostaglandinas , Vasoconstrictores , Anciano , Humanos , Masculino , Ratones , Femenino , Animales , Vasoconstrictores/farmacología , Ciclooxigenasa 1 , Prostaglandinas/metabolismo , Envejecimiento/metabolismo , Fenilefrina/farmacología , Ciclooxigenasa 2
6.
Mol Ecol ; 31(23): 5946-5965, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-34865259

RESUMEN

Research on telomeres in the fields of ecology and evolution has been rapidly expanding over the last two decades. This has resulted in the formulation of a multitude of, often name-given, hypotheses related to the associations between telomeres and life-history traits or fitness-facilitating processes (and the mechanisms underlying them). However, the differences (or similarities) between the various hypotheses, which can originate from different research fields, are often not obvious. Our aim here is therefore to give an overview of the hypotheses that are of interest in ecology and evolution and to provide two frameworks that help discriminate among them. We group the hypotheses (i) based on their association with different research questions, and (ii) using a hierarchical approach that builds on the assumptions they make, such as about causality of telomere length/shortening and/or the proposed functional consequences of telomere shortening on organism performance. Both our frameworks show that there exist parallel lines of thoughts in different research fields. Moreover, they also clearly illustrate that there are in many cases competing hypotheses within clusters, and that some of these even have contradictory assumptions and/or predictions. We also touch upon two topics in telomere research that would benefit from further conceptualization. This review should help researchers, both those familiar with and those new to the subject, to identify future avenues of research.


Asunto(s)
Rasgos de la Historia de Vida , Acortamiento del Telómero , Acortamiento del Telómero/genética , Ecología , Telómero/genética
7.
Dent Traumatol ; 38(1): 4-19, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34275184

RESUMEN

BACKGROUND/AIM: Dental trauma (DT) occurs frequently in children and adolescents. Therefore, understanding the factors associated with its occurrence in these age groups is important to establish specific preventive measures. The aim of this study was to investigate the relationships of lip coverage, overjet, and open bite to dental trauma in Brazilian children and adolescents. MATERIAL AND METHODS: The review protocol was registered in the PROSPERO database (CRD42020156290) and the bibliographic search was performed in nine electronic databases until July 2020. The studies included were observational, performed in Brazil, with healthy children and adolescents (0-19 years old), and without the restriction of date or language. Two reviewers assessed the individual risk of bias of the eligible studies with a standardized checklist. The meta-analyses were stratified by dentition stage and age range using fixed or random effects, odds ratio (OR) as the effect measure, and 95% confidence interval. The heterogeneity across studies was assessed with the I² test and the GRADE approach assessed the certainty of evidence. RESULTS: The search presented 2493 initial results, from which 55 met the eligibility criteria and were included. Most studies (67%) presented a low risk of bias and were published between 2000 and 2019. Children and adolescents with inadequate lip coverage are 1.86-2.36 times more likely to suffer from DT, while those with increased overjet are 1.94-3.11 times more likely. Children with primary dentitions and anterior open bites are 1.76 (95% CI: 1.20-2.59) times more likely to suffer from DT. The certainty of evidence varied from very low to moderate. CONCLUSIONS: Inadequate lip coverage, increased overjet, and anterior open bite are associated with the occurrence of dental trauma in Brazilian children and adolescents.


Asunto(s)
Maloclusión Clase II de Angle , Maloclusión , Sobremordida , Adolescente , Adulto , Brasil , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Labio , Adulto Joven
8.
Clin Sci (Lond) ; 135(15): 1845-1858, 2021 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-34269800

RESUMEN

OBJECTIVE: The mechanisms involved in NOX5 activation in atherosclerotic processes are not completely understood. The present study tested the hypothesis that lysophosphatidylcholine (LPC), a proatherogenic component of oxLDL, induces endothelial calcium influx, which drives NOX5-dependent reactive oxygen species (ROS) production, oxidative stress, and endothelial cell dysfunction. APPROACH: Human aortic endothelial cells (HAEC) were stimulated with LPC (10-5 M, for different time points). Pharmacological inhibition of NOX5 (Melittin, 10-7 M) and NOX5 gene silencing (siRNA) was used to determine the role of NOX5-dependent ROS production in endothelial oxidative stress induced by LPC. ROS production was determined by lucigenin assay and electron paramagnetic spectroscopy (EPR), calcium transients by Fluo4 fluorimetry, and NOX5 activity and protein expression by pharmacological assays and immunoblotting, respectively. RESULTS: LPC increased ROS generation in endothelial cells at short (15 min) and long (4 h) stimulation times. LPC-induced ROS was abolished by a selective NOX5 inhibitor and by NOX5 siRNA. NOX1/4 dual inhibition and selective NOX1 inhibition only decreased ROS generation at 4 h. LPC increased HAEC intracellular calcium, important for NOX5 activation, and this was blocked by nifedipine and thapsigargin. Bapta-AM, selective Ca2+ chelator, prevented LPC-induced ROS production. NOX5 knockdown decreased LPC-induced ICAM-1 mRNA expression and monocyte adhesion to endothelial cells. CONCLUSION: These results suggest that NOX5, by mechanisms linked to increased intracellular calcium, is key to early LPC-induced endothelial oxidative stress and pro-inflammatory processes. Since these are essential events in the formation and progression of atherosclerotic lesions, the present study highlights an important role for NOX5 in atherosclerosis.


Asunto(s)
Aterosclerosis/enzimología , Células Endoteliales/efectos de los fármacos , Lisofosfatidilcolinas/toxicidad , NADPH Oxidasa 5/metabolismo , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Aterosclerosis/patología , Calcio/metabolismo , Señalización del Calcio , Adhesión Celular , Células Cultivadas , Técnicas de Cocultivo , Células Endoteliales/enzimología , Células Endoteliales/patología , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Humanos , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/metabolismo , Monocitos/metabolismo , NADPH Oxidasa 5/antagonistas & inhibidores , NADPH Oxidasa 5/genética , Interferencia de ARN
10.
Mol Ecol ; 29(3): 485-501, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31846173

RESUMEN

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies "Candidatus Borrelia aligera" was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.


Asunto(s)
Borrelia/genética , Ixodes/microbiología , Enfermedad de Lyme/microbiología , Animales , Enfermedades de las Aves/microbiología , Europa (Continente) , Humanos , Tipificación de Secuencias Multilocus/métodos , Pájaros Cantores/microbiología
11.
Medicina (Kaunas) ; 56(9)2020 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-32825215

RESUMEN

Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.


Asunto(s)
Incisivo/patología , Incisivo/cirugía , Ligamento Periodontal/patología , Resorción Radicular/patología , Técnicas de Movimiento Dental/efectos adversos , Reimplante Dental , Animales , Incisivo/fisiopatología , Modelos Animales , Fotomicrografía , Complicaciones Posoperatorias/patología , Distribución Aleatoria , Ratas , Ratas Wistar , Resorción Radicular/etiología , Avulsión de Diente/cirugía , Raíz del Diente/patología
12.
J Mol Cell Cardiol ; 125: 61-72, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30339842

RESUMEN

BACKGROUND: Currently viewed as a complementary non-pharmacological intervention for preventing cardiac disorders, long-term aerobic training produces cardioprotection through remote ischemic preconditioning (RIPC) mechanisms. However, RIPC triggered by acute exercise remains poorly understood. Although resistance exercise (RE) has been highly recommended by several public health guidelines, there is no evidence showing that RE mediates RIPC. Hence, we investigated whether RE induces cardiac RIPC through nitric oxide synthase (NOS)-dependent mechanism. METHODS AND RESULTS: Acute RE at 40% of the maximal load augmented systemic nitrite levels, associated with increased cardiac eNOS phosphorylation, without affecting nNOS activity. Using an experimental model of myocardial infarction (MI) through ischemia-reperfusion (IR), RE fully prevented the loss of cardiac contractility and the extent of MI size compared to non-exercised (NE) rats. Moreover, RE mitigated aberrant ST-segment and reduced life-threatening arrhythmias induced by IR. Importantly, inhibition of NOS abolished the RE-mediated cardioprotection. After IR, NE rats showed increased cardiac eNOS activity, associated with reduced dimer/monomer ratio. Supporting the pivotal role of eNOS coupling during MI, non-exercised rats displayed a marked generation of reactive oxygen species (ROS) and oxidative-induced carbonylation of proteins, whereas RE prevented these responses. We validated our data demonstrating a restoration of physiological ROS levels in NE + IR cardiac sections treated with BH4, a cofactor oxidatively depleted during eNOS uncoupling, while cardiac ROS generation from exercised rats remained unchanged, suggesting no physiological needs of supplemental eNOS cofactors. CONCLUSION: Together, our findings strongly indicate that RE mediates RIPC by limiting eNOS uncoupling and mitigates myocardial IR injury.


Asunto(s)
Precondicionamiento Isquémico/métodos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Condicionamiento Físico Animal/fisiología , Animales , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/patología , Western Blotting , Electrocardiografía , Masculino , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo
13.
Scand J Psychol ; 59(6): 610-620, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30091786

RESUMEN

This study aimed to further the understanding of the processes involved in activism, as a form of collective action, based on differences in the quality of moral judgment and political ideology. It began with the assumption that differences in the quality of moral judgment can lead individuals to engage in different forms of collective action: activism or radicalism. Therefore, the associations among the variables political ideology, social identity, perception of social justice, activist identity and commitment, personal political salience, perception of efficacy and life purpose were analyzed. Path modelling was used to construct two models of political action: one based on conventional moral judgment and conservative political ideology, and the other based on post-conventional moral judgment and egalitarian political ideology. These two models were tested on samples of Brazilian and Spanish youths. The results confirmed the validity of using developmental social psychology to understand activism as a form of political action. The results confirmed the central hypothesis that differences in the quality of moral judgment and in political ideology are related to willingness to engage in qualitatively different types of actions: young people with conventional moral judgment and conservative political ideology declared their intention to engage in activism, while young people with post-conventional moral judgment egalitarian political ideology reported the intention to engage in both activist and radical actions.


Asunto(s)
Juicio , Principios Morales , Política , Justicia Social , Adolescente , Adulto , Femenino , Humanos , Masculino , Modelos Teóricos , Identificación Social , Adulto Joven
14.
Naturwissenschaften ; 104(11-12): 101, 2017 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-29138941

RESUMEN

Differential migration has been extensively reported in spring, but less so in autumn, particularly in relation to sex in monomorphic bird species. Here, we analysed the autumn passage of a monomorphic, globally threatened passerine, the Aquatic Warbler Acrocephalus paludicola throughout Western Europe, with regard to age and sex. We showed that, overall, adults migrated earlier than first-year birds, and males migrated earlier than females during the autumn migration. This may be caused by an overall social dominance of adults over immatures, and differentiated migration strategy of males and females. In addition, we found male-skewed sex proportions, with a tendency to an equalised ratio in more southern stopover sites. This may indicate a male bias in the global population or different migration strategies of the sexes. Differential migration may cause the age and sex classes to be exposed differently to various threats affecting demographic structure of the species.


Asunto(s)
Migración Animal , Passeriformes/fisiología , Estaciones del Año , Razón de Masculinidad , Animales , Femenino , Geografía , Masculino , Factores de Tiempo
15.
Antonie Van Leeuwenhoek ; 110(6): 727-736, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28190154

RESUMEN

The phylogenetic classification of the species Burkholderia andropogonis within the Burkholderia genus was reassessed using 16S rRNA gene phylogenetic analysis and multilocus sequence analysis (MLSA). Both phylogenetic trees revealed two main groups, named A and B, strongly supported by high bootstrap values (100%). Group A encompassed all of the Burkholderia species complex, whi.le Group B only comprised B. andropogonis species, with low percentage similarities with other species of the genus, from 92 to 95% for 16S rRNA gene sequences and 83% for conserved gene sequences. Average nucleotide identity (ANI), tetranucleotide signature frequency, and percentage of conserved proteins POCP analyses were also carried out, and in the three analyses B. andropogonis showed lower values when compared to the other Burkholderia species complex, near 71% for ANI, from 0.484 to 0.724 for tetranucleotide signature frequency, and around 50% for POCP, reinforcing the distance observed in the phylogenetic analyses. Our findings provide an important insight into the taxonomy of B. andropogonis. It is clear from the results that this bacterial species exhibits genotypic differences and represents a new genus described herein as Robbsia andropogonis gen. nov., comb. nov.


Asunto(s)
Burkholderia , ADN Bacteriano , Técnicas de Tipificación Bacteriana , Burkholderia/clasificación , Burkholderia/genética , Clasificación , ADN Ribosómico , Genotipo , Tipificación de Secuencias Multilocus , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN
16.
Asian-Australas J Anim Sci ; 30(9): 1340-1349, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28183165

RESUMEN

OBJECTIVE: This study aimed to evaluate the microbiological and cellular milk profile for the diagnosis of subclinical mastitis in female buffaloes and to assess risk factors for predisposition of the disease. METHODS: Analyses were carried out by standard plate count (SPC), identification of species and antibiotic resistance, somatic cell count (SCC), electrical electrical conductivity of milk (ECM), and lactoferrin content in milk. Teat cups were swabbed to evaluate risk factors, observing hyperkeratosis, milking vacuum pressure and cleanliness of the site. Hence, 30 female buffaloes were randomly selected (15 from a group in early lactation and 15 in late lactation). RESULTS: The most common bacteria in the microbiological examination were Staphylococcus spp., Streptococcus spp. and Corynebacterium sp. In the antibiotic sensitivity test, 10 (58.82%) of the 17 antibiotics tested were sensitive to all isolates, and resistant bacteria were Streptococcus uberis, Streptococcus dysgalactiae, Streptococcus haemolyticus, and Escherichia coli. It was observed that positive samples in the microbiological examination showed total bacterial count between 9.10×103 to 6.94×106 colony forming units/mL, SCC between 42,000 to 4,320,000 cells/mL and ECM ranging from 1.85 to 7.40 mS/cm. It was also found that the teat cups had high microbial counts indicating poor hygiene, and even faults in the cleanliness of the animals' waiting room were observed. It is concluded that values of SCC above 537,000 cells/mL and ECM above 3.0 mS/mL are indications of mammary gland infection for this herd; however, the association of these values with a microbiological analysis is necessary to more accurately evaluate the health status of mammary glands with subclinical mastitis. CONCLUSION: Through phenotypic characterization of bacteria involved in the samples, the genera Staphylococcus spp., Streptococcus spp., and Corynebacterimum bovis were the most prevalent in this study. Faults in environment and equipment hygienization are factors that are directly associated with mastitis.

17.
Oecologia ; 182(4): 985-994, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27638183

RESUMEN

Amongst migratory species, it is common to find individuals from different populations or geographical origins sharing staging or wintering areas. Given their differing life histories, ecological theory would predict that the different groups of individuals should exhibit some level of niche segregation. This has rarely been investigated because of the difficulty in assigning migrating individuals to breeding areas. Here, we start by documenting a broad geographical gradient of hydrogen isotopes (δ 2H) in robin Erithacus rubecula feathers across Europe. We then use δ 2H, as well as wing-tip shape, as surrogates for broad migratory origin of birds wintering in Iberia, to investigate the ecological segregation of populations. Wintering robins of different sexes, ages and body sizes are known to segregate between habitats in Iberia. This has been attributed to the despotic exclusion of inferior competitors from the best patches by dominant individuals. We find no segregation between habitats in relation to δ 2H in feathers, or to wing-tip shape, which suggests that no major asymmetries in competitive ability exist between migrant robins of different origins. Trophic level (inferred from nitrogen isotopes in blood) correlated both with δ 2H in feathers and with wing-tip shape, showing that individuals from different geographic origins display a degree of ecological segregation in shared winter quarters. Isotopic mixing models indicate that wintering birds originating from more northerly populations consume more invertebrates. Our multi-scale study suggests that trophic-niche segregation may result from specializations (arising in the population-specific breeding areas) that are transported by the migrants into the shared wintering grounds.


Asunto(s)
Migración Animal , Pájaros Cantores , Animales , Plumas/química , Isótopos de Nitrógeno , Estaciones del Año
18.
Parasitology ; 142(9): 1183-9, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25924680

RESUMEN

The diversity and prevalence of malaria parasites of the genera Plasmodium and Haemoproteus were determined in the globally-threatened Aquatic Warbler Acrocephalus paludicola. Birds were sampled during migration in Portugal and at the wintering quarters in Senegal and parasites were detected using molecular methods. Only three generalist parasite lineages (Plasmodium) were found. There were no significant differences in the prevalence of parasites between sexes in Europe, but adults had higher prevalence than first-year birds, and birds in Europe had higher prevalence than those captured in Africa. When comparing with other Acrocephalus species and taking sample size into account, Aquatic Warblers had the lowest prevalence and, together with another threatened species, the Seychelles Warbler Acrocephalus sechellensis, the lowest diversity of malaria parasites. We hypothesize that the low diversity of parasites and absence of specialist lineages of Aquatic Warblers are caused by its small population size and fragmented distribution. Furthermore, Aquatic Warblers' extreme habitat specialization may decrease their exposure to malaria parasites, but other explanations such as high mortality (which would constraint the sampling of infected birds) or, in contrast, very efficient immunological system in clearing the infections cannot be ruled out. This study contributes to explain variation in prevalence and diversity of malaria parasites among hosts.


Asunto(s)
Enfermedades de las Aves/parasitología , Variación Genética , Haemosporida/genética , Passeriformes , Infecciones Protozoarias en Animales/parasitología , Animales , Especies en Peligro de Extinción , Haemosporida/aislamiento & purificación , Estaciones del Año
19.
Proc Natl Acad Sci U S A ; 109(28): E1972-9, 2012 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-22699502

RESUMEN

Cassava bacterial blight (CBB), incited by Xanthomonas axonopodis pv. manihotis (Xam), is the most important bacterial disease of cassava, a staple food source for millions of people in developing countries. Here we present a widely applicable strategy for elucidating the virulence components of a pathogen population. We report Illumina-based draft genomes for 65 Xam strains and deduce the phylogenetic relatedness of Xam across the areas where cassava is grown. Using an extensive database of effector proteins from animal and plant pathogens, we identify the effector repertoire for each sequenced strain and use a comparative sequence analysis to deduce the least polymorphic of the conserved effectors. These highly conserved effectors have been maintained over 11 countries, three continents, and 70 y of evolution and as such represent ideal targets for developing resistance strategies.


Asunto(s)
Manihot/metabolismo , Manihot/microbiología , Enfermedades de las Plantas/microbiología , Análisis de Secuencia de ADN/métodos , Xanthomonas axonopodis/metabolismo , Área Bajo la Curva , Progresión de la Enfermedad , Genoma Bacteriano , Genómica , Geografía , Inmunidad Innata , Modelos Genéticos , Datos de Secuencia Molecular , Filogenia , Enfermedades de las Plantas/genética , Polimorfismo Genético , Polimorfismo de Nucleótido Simple , Factores de Tiempo
20.
Life Sci ; 338: 122361, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38158040

RESUMEN

AIMS: Overproduction of reactive oxygen species (ROS) is a pathologic hallmark of cyclophosphamide toxicity. For this reason, antioxidant compounds emerge as promising tools for preventing tissue damage induced by cyclophosphamide. We hypothesized that melatonin would display cytoprotective action in the vasculature by preventing cyclophosphamide-induced oxidative stress. MATERIALS AND METHODS: Male C57BL/6 mice (22-25 g) were injected with a single dose of cyclophosphamide (300 mg/kg; i.p.). Mice were pretreated or not with melatonin (10 mg/kg/day, i.p.), given during 4 days before cyclophosphamide injection. Functional (vascular reactivity) and oxidative/inflammatory patterns were evaluated at 24 h in resistance arteries. The antioxidant action of melatonin was assessed in vitro in cultured vascular smooth muscle cells (VSMCs) of mesenteric arteries. KEY FINDINGS: Cyclophosphamide induced ROS generation in both mesenteric arterial bed (MAB) and cultured VSMCs, and this was normalized by melatonin. Cyclophosphamide-induced ROS generation and lipoperoxidation in the bladder and kidney was also prevented by melatonin. Increased levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 were detected in the MAB of cyclophosphamide-treated mice, all of which were prevented by melatonin. Functional assays using second-order mesenteric arteries of cyclophosphamide-treated mice revealed a decrease in vascular contractility. Melatonin prevented vascular hypocontractility in the cyclophosphamide group. Melatonin partially prevented the decrease in myeloperoxidase (MPO) and N-acetyl-beta-D-glucosaminidase (NAG) activities in the MAB of the cyclophosphamide group. SIGNIFICANCE: Melatonin may constitute a novel and promising therapeutic approach for management of the toxic effects induced by cyclophosphamide in the vasculature.


Asunto(s)
Melatonina , Ratones , Masculino , Animales , Especies Reactivas de Oxígeno/farmacología , Melatonina/uso terapéutico , Antioxidantes/metabolismo , Ratones Endogámicos C57BL , Ciclofosfamida/toxicidad , Estrés Oxidativo , Arterias Mesentéricas/metabolismo
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