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1.
Mech Adv Mat Struct ; 30(22): 4582-4596, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38014414

RESUMEN

This paper presents the numerical damage analysis of concrete structures using higher-order beam theories based on Carrera Unified Formulation (CUF). The concrete constitutive relation is modeled using continuum damage mechanics based on a modified Mazars concrete damage model, in which both the tensile and compressive softening behaviors are regularized with classical fracture energy methodology. An expression is proposed to estimate the characteristic length in higher-order beam theories, to prevent mesh dependency. Both softening constitutive laws and fracture energy calculations are obtained according to Model Code 2010. To assess the efficiency of the proposed model, three classical benchmark quasi-static experiments are taken for validation. From the comparison between numerical and experimental results, the proposed CUF model using continuum damage mechanics can present 3D accuracy with low computational costs and reduce the mesh dependency.

2.
J Endocrinol Invest ; 42(7): 797-807, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30465247

RESUMEN

PURPOSE: Metabolic syndrome (MS) and sarcopenia are associated with increased cardiovascular risk. No studies using dual-energy x-ray absorptiometry (DXA) have evaluated association between body composition (BC) changes and MS in adrenal incidentaloma (AI). Our aim was to analyse BC in non-functioning AI (NFAI) and intermediate phenotype (IP) relative to controls and to correlate with cortisol levels. METHODS: Cross-sectional study with 44 NFAI (serum cortisol ≤ 50 nmol/L after the overnight 1 mg dexamethasone suppression test), 27 IP (cortisol 51-138 nmol/L), and 41 controls (normal adrenal on imaging examination) using DXA. Autonomic cortisol secretion (cortisol > 138 nmol/L) was excluded from the study. BC data were compared using criteria for MS (World Health Organization, National Cholesterol Education Program-Adult Treatment Panel-III, American Association of Clinical Endocrinologists (AACE), and International Diabetes Federation). RESULTS: There was no significant difference in clinical data and body mass index (BMI) among the three groups. Waist circumference (WC) was larger in AI vs. controls (p < 0.01). Waist-to-hip ratio was higher in NFAI vs. controls and waist-to-height ratio was higher in IP vs. controls (p = 0.03 and p = 0.02, respectively). The frequency of MS was higher in AI vs. controls. BC was not different among the groups. Patients with AI there was a significant association of MS with both an increase in total fat and body fat index (all criteria), and a significant difference between MS and smaller BMI-adjusted lean mass (AACE, p = 0.036). No correlation of cortisol after 1 mg dexamethasone test with BC or MS. AI and WC were independently associated with MS. CONCLUSIONS: AI presented high frequency of MS and was independently associated with MS. Possible deleterious effects of cortisol secretion seem to initially affect the muscular system.


Asunto(s)
Absorciometría de Fotón/métodos , Neoplasias de las Glándulas Suprarrenales/complicaciones , Composición Corporal , Síndrome Metabólico/diagnóstico , Fenotipo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Masculino , Síndrome Metabólico/etiología , Persona de Mediana Edad , Pronóstico , Adulto Joven
3.
J Phys Chem A ; 122(51): 9755-9760, 2018 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-30520626

RESUMEN

The photofragmentation dynamics of 1,1,1,2-tetrafluoroethane (R134a) with photon energies from 12 eV up to 320 eV, surrounding the C 1s edge is discussed. The ionic moieties were measured in coincidence with the ejected electrons (PEPICO mode), and detected as a function of the photon energy. Around the C K core edge, the fragmentation profiles are examined regarding the site specific excitation of the CH2FCF3 molecule. In the present case, site-selectivity is favored by the distinct chemical environments surrounding both C atoms. NEXAFS spectrum at the C 1s edge simulation has been obtained at the TDDFT level and excited state geometry optimization calculations have been performed at the inner-shell multiconfigurational self-consistent field level. Our observations indicate that the C(H2F) 1s excitation to a highly repulsive potential expels a fluorine atom leaving the heavier radical fragment C2F3H2* which relaxes to the fundamental state of the ion C2F3H2+. On the other hand, the excitation from the C(F3) 1s carbon to a repulsive state in the C-C bond, leads to a C-C bond cleavage, explaining the observed site specific fragmentation.

4.
Curr Pain Headache Rep ; 21(7): 31, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28551735

RESUMEN

PURPOSE OF REVIEW: Headache is a common complaint among children and adolescents. School functioning is one of the most important life domains impacted by chronic pain in children. This review discusses the epidemiological and pathophysiological connections between headaches and school functioning including a suggested clinical approach. RECENT FINDINGS: The connection between recurrent and chronic headache and learning disabilities might be psychosocial (fear of failure) or anatomical (malfunctioning of the frontal and prefrontal areas). Only few population-based and clinical studies were done and good studies are still needed in order to understand the complex relationship better. However, relating to our patients' learning and school performance, history is crucial when a child with primary headaches is evaluated. Learning disabilities seem to have a high prevalence among children with primary headache syndromes especially migraine. The connection between the two is complex and might be either part of a common brain pathophysiology and/or a consequence of poor quality of life.


Asunto(s)
Escolaridad , Cefaleas Primarias/fisiopatología , Adolescente , Niño , Lóbulo Frontal/fisiopatología , Cefaleas Primarias/epidemiología , Cefaleas Primarias/psicología , Humanos , Aprendizaje , Discapacidades para el Aprendizaje/etiología , Trastornos Migrañosos/fisiopatología , Corteza Prefrontal/fisiopatología , Prevalencia , Calidad de Vida
5.
Opt Lett ; 41(13): 3126-9, 2016 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-27367118

RESUMEN

The concept of non-Markovianity (NM) in quantum dynamics is still an open debate. Understanding how to generate and measure NM in specific models may aid in this quest. In quantum optics, an engineered electromagnetic environment coupled to a single atom can induce NM. The most common scenario of structured electromagnetic environment is an optical cavity, composed by a pair of mirrors. Here, we show how to generate and measure NM on a two-level system coupled to a one-dimensional waveguide with no mirrors required. The origin of the non-Markovian behavior lies in the initial state of the field, prepared as a single-photon packet. NM is shown to depend on two experimentally controllable parameters, namely, the linewidth of the packet and its central frequency. We relate the presence of NM to quantum interference. We also show how the two output channels of the waveguide provide distinct signatures of NM, both experimentally accessible.

6.
J Endocrinol Invest ; 38(11): 1159-66, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25957829

RESUMEN

PURPOSE: Ipilimumab is a human monoclonal antibody against cytotoxic T-lymphocyte antigen 4 available as an immunotherapy mainly for advanced melanoma. It induces an activation of T cells, resulting in an immune-mediated anti-tumor response and also immune-related adverse events, including hypophysitis. The aim of this review is to identify and discuss features concerning ipilimumab-induced hypophysitis (IIH). DESIGN: A MEDLINE research of all years of publication of IIH was conducted. We gathered information regarding clinical, radiologic and laboratory features of 71 cases recorded in the literature. RESULTS: In our review, IIH was more frequent among older and male patients. Fatigue and headache were the most frequent initial clinical manifestations of IIH and enlargement of the pituitary gland at MRI was present in the majority of patients. Those who received more than 3 cycles of ipilimumab had more fatigue (p = 0.04) and arthritis (p = 0.04). Adrenal insufficiency was more prevalent in men (p = 0.007). Glucocorticoid therapy and hormone replacement were required in most patients and pituitary function recovery was uncommon. Low prolactin at diagnosis tended to predict permanent pituitary dysfunction (p = 0.07). CONCLUSION: Hypopituitarism as a consequence of IIH, if not promptly recognized, can lead to potentially fatal events, such as adrenal insufficiency. IIH can be easily managed with glucocorticoids and hormonal replacement; therefore, physicians should be familiar with the key aspects of this condition. More studies to develop screening protocols and therapeutic intervention algorithms should be performed to decrease morbidity related to IIH.


Asunto(s)
Anticuerpos Monoclonales/efectos adversos , Hipopituitarismo/inducido químicamente , Factores Inmunológicos/efectos adversos , Melanoma/tratamiento farmacológico , Enfermedades de la Hipófisis/inducido químicamente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Ipilimumab , Masculino , Persona de Mediana Edad
7.
Int Endod J ; 46(8): 700-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23442003

RESUMEN

Diabetes mellitus (DM) is one of the most common metabolic disorders. DM is characterized by hyperglycaemia, resulting in wound healing difficulties and systemic and oral manifestations, which have a direct effect on dental pulp integrity. Experimental and clinical studies have demonstrated a higher prevalence of periapical lesions in patients with uncontrolled diabetes. The influence of DM on periapical bone resorption and its impact on dental intervention of such patients are reviewed, and its aetiology and pathogenesis are analysed at molecular level. Pulps from patients with diabetes have the tendency to present limited dental collateral circulation, impaired immune response, increased risk of acquiring pulp infection (especially anaerobic ones) or necrosis, besides toothache and occasional tendency towards pulp necrosis caused by ischaemia. In regard to molecular pathology, hyperglycaemia is a stimulus for bone resorption, inhibiting osteoblastic differentiation and reducing bone recovery. The relationship between poorly controlled diabetes and bone metabolism is not clearly understood. Molecular knowledge about pulp alterations in patients with diabetes could offer new therapeutic directions. Knowledge about how diabetes affects systemic and oral health has an enduring importance, because it may imply not only systemic complications but also a higher risk of oral diseases with a significant effect on pulp and periapical tissue.


Asunto(s)
Complicaciones de la Diabetes , Periodontitis Periapical/complicaciones , Pulpitis/complicaciones , Pérdida de Hueso Alveolar/complicaciones , Complicaciones de la Diabetes/sangre , Complicaciones de la Diabetes/fisiopatología , Humanos , Hiperglucemia/complicaciones , Factores de Riesgo , Tratamiento del Conducto Radicular
8.
Genet Mol Res ; 12(4): 5057-71, 2013 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-24301767

RESUMEN

Chromobacterium violaceum is a Gram-negative proteobacteria found in water and soil; it is widely distributed in tropical and subtropical regions, such as the Amazon rainforest. We examined protein expression changes that occur in C. violaceum at different growth temperatures using electrophoresis and mass spectrometry. The total number of spots detected was 1985; the number ranged from 99 to 380 in each assay. The proteins that were identified spectrometrically were categorized as chaperones, proteins expressed exclusively under heat stress, enzymes involved in the respiratory and fermentation cycles, ribosomal proteins, and proteins related to transport and secretion. Controlling inverted repeat of chaperone expression and inverted repeat DNA binding sequences, as well as regions recognized by sigma factor 32, elements involved in the genetic regulation of the bacterial stress response, were identified in the promoter regions of several of the genes coding proteins, involved in the C. violaceum stress response. We found that 30 °C is the optimal growth temperature for C. violaceum, whereas 25, 35, and 40 °C are stressful temperatures that trigger the expression of chaperones, superoxide dismutase, a probable small heat shock protein, a probable phasing, ferrichrome-iron receptor protein, elongation factor P, and an ornithine carbamoyltransferase catabolite. This information improves our comprehension of the mechanisms involved in stress adaptation by C. violaceum.


Asunto(s)
Adaptación Biológica , Proteínas Bacterianas/metabolismo , Chromobacterium/metabolismo , Proteómica , Estrés Fisiológico , Temperatura , Adaptación Biológica/genética , Proteínas Bacterianas/genética , Respiración de la Célula , Chromobacterium/genética , Chromobacterium/crecimiento & desarrollo , Fermentación , Regulación Bacteriana de la Expresión Génica , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Sistemas de Lectura Abierta , Regiones Promotoras Genéticas , Proteómica/métodos , Estrés Fisiológico/genética
9.
Bull Entomol Res ; 101(6): 643-58, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21729392

RESUMEN

Deforestation has been linked to a rise in malaria prevalence. In this paper, we studied longitudinally 20 spots, including forested and deforested portions of a temporary river in a malarigenous frontier zone. Larval habitat parameters influencing distribution of Anopheles darlingi (Diptera: Culicidae) larvae were studied. We observed that larvae were clustered in forested-deforested transitions. For the first time in the literature, it was verified that parameters determining larval distribution varied from deforested to forested areas. The proximity to human dwellings was also a significant factor determining distribution, but larvae was most importantly associated with a previously undescribed parameter, the presence of small obstructions to river flow, such as tree trunks within the river channel, which caused pooling of water during the dry season ('microdams'). In deforested areas, the most important factor determining distribution of larvae was shade (reduced luminance). Larvae were absent in the entire studied area during the wet season and present in most sites during the dry season. During the wet-dry transition, larvae were found sooner in areas with microdams, than in other areas, suggesting that flow obstruction prolongs the breeding season of An. darlingi. Adult mosquito densities and malaria incidence were higher during the dry season. Our data correlate well with the published literature, including the distribution of malaria cases near the forest fringes, and has permitted the creation of a model of An. darlingi breeding, where preference for sites with reduced luminance, human presence and microdams would interact to determine larval distribution.


Asunto(s)
Anopheles , Conservación de los Recursos Naturales , Insectos Vectores , Larva , Malaria/transmisión , Análisis de Varianza , Animales , Brasil , Ecosistema , Dinámica Poblacional , Análisis de Componente Principal , Análisis de Regresión , Reproducción , Ríos
10.
Scand J Immunol ; 70(1): 10-7, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19522762

RESUMEN

To better understand the interactions between opportunistic fungi and their hosts, we investigated hydrogen peroxide (H2O2), nitric oxide and TNF-alpha production by peritoneal macrophages from Ehrlich tumour-bearing mice (TBM) during microbial infections. For this purpose, TBM at days 7, 14 and 21 of tumour progression were inoculated intraperitoneally with C. albicans and evaluated after 24 and 72 h. We observed that TBM showed significant increases in H2O2, TNF-alpha levels and fungal clearance at day 7 after C. albicans infection. However, as the tumour advanced, there was a progressive decline in the release of H2O2 and TNF-alpha that was paired with the dissemination of C. albicans. These results demonstrate that protective macrophage activities against Candida albicans are limited to the initial stages of tumour growth; continued solid tumour growth weakened the macrophage response and as a consequence, weakened the host's susceptibility to opportunistic infections.


Asunto(s)
Candidiasis/complicaciones , Candidiasis/inmunología , Carcinoma de Ehrlich/complicaciones , Carcinoma de Ehrlich/inmunología , Macrófagos Peritoneales/inmunología , Infecciones Oportunistas/complicaciones , Animales , Candida albicans , Peróxido de Hidrógeno/metabolismo , Macrófagos Peritoneales/metabolismo , Masculino , Ratones , Óxido Nítrico/biosíntesis , Infecciones Oportunistas/inmunología , Factor de Necrosis Tumoral alfa/biosíntesis
11.
J Cell Biol ; 111(3): 1069-79, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2391360

RESUMEN

Fimbrin is an actin-bundling protein found in intestinal microvilli, hair cell stereocilia, and fibroblast filopodia. The complete protein sequence (630 residues) of chicken intestine fimbrin has been determined from two full-length cDNA clones. The sequence encodes a small amino-terminal domain (115 residues) that is homologous with two calcium-binding sites of calmodulin and a large carboxy-terminal domain (500 residues) consisting of a fourfold-repeated 125-residue sequence. This repeat is homologous with the actin-binding domain of alpha-actinin and the amino-terminal domains of dystrophin, actin-gelation protein, and beta-spectrin. The presence of this duplicated domain in fimbrin links actin bundling proteins and gelation proteins into a common family of actin cross-linking proteins. Fimbrin is also homologous in sequence with human L-plastin and T-plastin. L-plastin is found in only normal or transformed leukocytes where it becomes phosphorylated in response to IL 1 or phorbol myristate acetate. T-plastin is found in cells of solid tissues where it does not become phosphorylated. Neoplastic cells derived from solid tissues express both isoforms. The differences in expression, sequence, and phosphorylation suggest possible functional differences between fimbrin isoforms.


Asunto(s)
Calmodulina/genética , Glicoproteínas de Membrana/genética , Proteínas de Microfilamentos/genética , Fosfoproteínas/genética , Actinas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Calcio/metabolismo , Calcio/fisiología , Proteínas de Unión al Calcio/genética , Proteínas Portadoras/genética , Pollos , Reacciones Cruzadas , Regulación de la Expresión Génica , Datos de Secuencia Molecular , Fosforilación , Secuencias Repetitivas de Ácidos Nucleicos , Homología de Secuencia de Ácido Nucleico , Relación Estructura-Actividad
12.
Horm Res ; 72(5): 275-80, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19844113

RESUMEN

BACKGROUND: Growth hormone (GH) is a therapeutic option for small for gestational age (SGA) children without spontaneous catch-up. There are few reports on preterm SGA children. Prematurity is an additional risk factor for adult short stature. AIM: To describe GH efficacy in preterm SGA patients. METHODS: Twenty-five preterm SGA patients, 2-4 years old, treated with GH 0.066 mg/kg/day, were compared with 14 age-matched preterm SGA historical controls. Height, weight, IGF-I, IGFBP-3, fasting glucose and insulin were measured every 6 months. RESULTS: At start of GH treatment, mean height and weight were -2.4 and -2.4 SDS, respectively. There was a significant increment in height SDS of 1.3 and 2.1 during the 1st and the 2nd year of GH therapy, respectively. There was no significant difference between the progression of chronological and bone ages. A significant increase in IGF-I, IGFBP-3 and molar ratio was observed during GH therapy. There was no difference in glucose, insulin or HOMA-IR index. CONCLUSION: We showed for the first time that the height increment of preterm SGA with GH treatment is similar to that described in other studies with term SGA patients. Therefore, short-term GH treatment in a subset of preterm SGA patients between 2-4 years of age was able to promote adequate growth recovery with no excessive bone age acceleration or adverse effects on carbohydrate metabolism.


Asunto(s)
Trastornos del Crecimiento/tratamiento farmacológico , Hormona de Crecimiento Humana/uso terapéutico , Recien Nacido Prematuro/crecimiento & desarrollo , Recién Nacido Pequeño para la Edad Gestacional/crecimiento & desarrollo , Determinación de la Edad por el Esqueleto , Estatura/efectos de los fármacos , Índice de Masa Corporal , Preescolar , Estudios de Seguimiento , Trastornos del Crecimiento/sangre , Trastornos del Crecimiento/fisiopatología , Hormona de Crecimiento Humana/sangre , Humanos , Lactante , Recién Nacido , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Proteínas Recombinantes/uso terapéutico
13.
Med Vet Entomol ; 23(4): 335-49, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19941599

RESUMEN

Three communities separated by 1.5-7.0 km, along the Matapí River, Amapá State, Brazil, were sampled monthly from April 2003 to November 2005 to determine relationships between seasonal abundance of host-seeking anophelines, rainfall and malaria cases. Out of the 759 821 adult female anophelines collected, Anopheles darlingi Root (Diptera: Culicidae) was the most abundant (56.2%) followed by An. marajoara Galvão & Damasceno (24.6%), An. nuneztovari Gabaldón (12.4%), An. intermedius (Chagas) (4.4%) and An. triannulatus (Neiva and Pinto) (2.3%). Vector abundance, as measured by human landing catches, fluctuated during the course of the study and varied in species-specific ways with seasonal patterns of rainfall. Anopheles darlingi and An. triannulatus were more abundant during the wet-dry transition period in June to August, whereas An. marajoara began to increase in abundance in February in two villages, and during the wet-dry transition in the other village. Anopheles nuneztovari and An. intermedius increased in abundance shortly after the rains began in January to February. A generalized linear mixed model (GLMM) analysis of 32 consecutive months of collections showed significant differences in abundance for each species by village and date (P < 0.0001). Correlations between lagged rainfall and abundances also differed among species. A strong positive correlation of An. darlingi abundance with rainfall lagged by 4 and 5 months (Pearson's r = 0.472-0.676) was consistent among villages and suggests that rainfall may predict vector abundance. Significant correlations were detected between numbers of malaria cases and abundances of suspected vector species. The present study shows how long-term field research may connect entomological and climatological correlates with malaria incidence.


Asunto(s)
Anopheles/parasitología , Ecosistema , Insectos Vectores/parasitología , Malaria/transmisión , Plasmodium/crecimiento & desarrollo , Animales , Brasil/epidemiología , Femenino , Humanos , Incidencia , Malaria/epidemiología , Malaria/parasitología , Lluvia , Ríos , Población Rural , Estaciones del Año , Estadísticas no Paramétricas
14.
Vet Parasitol ; 266: 96-102, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30736955

RESUMEN

Central nervous system (CNS) is the main site for encystment of Neospora caninum in different animal species. In this tissue, glial cells (astrocytes and microglia) modulate responses to aggression in order to preserve homeostasis and neuronal function. Previous data showed that when primary cultures of glial cells are infected with N. caninum, they develop gliosis and the immune response is characterized by the release of TNF and IL-10, followed by the control of parasite proliferation. In order to elucidate this control, three enzymatic systems involved in parasite-versus-host interactions were observed on a model of neuron/glia co/cultures obtained from rat brains. Indoleamine 2,3-dioxygenase (IDO), induced nitric oxide synthase (iNOS) responsible for the catabolism of tryptophan and arginine, respectively, and cycloxigenase (COX) were studied comparing their modulation by respective inhibitors with the number of tachyzoites or the immune response measured by the release of IL-10 and TNF. Cells were treated with the inhibitors of iNOS (1.5 mM L-NAME), IDO (1 mM 1-methyl tryptophan), COX-1 (1 µM indomethacin) and COX-2 (1 µM nimesulide) before infection with tachyzoites of N. caninum (1:1 cell: parasite). After 72 h of infection, immunocytochemistry showed astrogliosis and a significant increase in the number and length of neurites, compared with uninfected co-cultures, while an increase of IL-10 and TNF was verified. N. caninum did not change iNOS activity, but the inhibition of the basal levels of this enzyme stimulated parasite proliferation. Additionally, a significant increase of about 40% was verified in the IDO activity, whose inhibition caused 1.2-fold increase in parasitic growth. For COX-2 activity, infection of cultures stimulated a significant increase in release of PGE2 and its inhibition by nimesulide allowed the parasitic growth. These data indicate that iNOS, IDO and COX-2 control the proliferation of N. caninum in this in vitro model. On the other hand, the release of IL-10 by glia besides modulating the inflammation also allow the continuity of parasitism.


Asunto(s)
Ciclooxigenasa 2/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Neospora/crecimiento & desarrollo , Neuroglía/parasitología , Neuronas/parasitología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Animales , Células Cultivadas , Técnicas de Cocultivo , Inhibidores de la Ciclooxigenasa/farmacología , Dinoprostona/análisis , Interacciones Huésped-Parásitos , Indometacina/farmacología , Interleucina-10/metabolismo , NG-Nitroarginina Metil Éster/farmacología , Neospora/efectos de los fármacos , Neuroglía/efectos de los fármacos , Neuronas/efectos de los fármacos , Ratas , Sulfonamidas/farmacología , Triptófano/análogos & derivados , Triptófano/farmacología , Factor de Necrosis Tumoral alfa/metabolismo
15.
Biomed Pharmacother ; 113: 108728, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30856536

RESUMEN

Glioblastoma, which is highly invasive and has a poor patient prognosis, is the most common type of brain tumor. Flavonoids have known antiproliferative and antineoplastic effects, such as apoptosis induction and tumor growth inhibition. We investigated the effects of treatment with three flavonoids (BAS-1, BAS-4, and BAS-6) isolated from the Amazon plant Brosimum acutifolium on the proliferation and migration of the C6 glioma cell line. Cytotoxicity was evaluated by MTT assay, and morphological changes were evaluated by phase-contrast microscopy and by transmission electron microscopy. Apoptosis was determined using Annexin V-FITC-propidium iodide (PI) staining. A hemolysis assay was used to evaluate plasma membrane injury. Antiproliferative effects were assessed by wound migration and colony formation assays. Mitochondrial transmembrane potential (ΔΨm) was determined using JC-1 dye and flow cytometry. To identify the flavonoid targets, western blotting was performed. BAS-1 and BAS-4 reduced C6 cell proliferation in a dose-dependent manner. BAS-6 showed no effect. Due to its high toxicity toward primary glial cells and its high hemolytic index, BAS-1 was not used in the remaining experiments. BAS-4 treatment did not induce cytotoxicity in primary glial cells; however, in glioma cells, it suppressed migration and invasion and led to apoptosis through mitochondrial damage, ΔΨm loss, cell cycle arrest, and reduced AKT phosphorylation, which is a component of the main cell survival pathway. We conclude that BAS-4 showed potential activity against glioma by inducing apoptosis mediated by ΔΨm loss and AKT pathway disruption, and future studies should further evaluate BAS-4 as a promising antineoplastic agent against glioblastoma.


Asunto(s)
Neoplasias Encefálicas/tratamiento farmacológico , Flavonoides/farmacología , Glioma/tratamiento farmacológico , Moraceae/química , Animales , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Neoplasias Encefálicas/patología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Flavonoides/administración & dosificación , Flavonoides/aislamiento & purificación , Citometría de Flujo , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Glioma/patología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar
16.
Antimicrob Agents Chemother ; 52(12): 4497-502, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18838582

RESUMEN

The major human immunodeficiency virus type 1 subtype circulating in Brazil is B, followed by F and C. We have genotyped 882 samples from Brazilian patients for whom highly active antiretroviral therapy failed, and we found subtype B and the unique recombinant B/F1 forms circulating. Due to codon usage variation, there is a significantly lower incidence of the substitutions L210W, Q151M, and F116Y in subtype F1 isolates than in the subtype B counterparts.


Asunto(s)
Terapia Antirretroviral Altamente Activa , Codón/genética , Farmacorresistencia Viral/genética , Infecciones por VIH/tratamiento farmacológico , VIH-1/efectos de los fármacos , Mutación , Brasil , Recuento de Linfocito CD4 , Femenino , Genotipo , Infecciones por VIH/virología , Proteasa del VIH/genética , Transcriptasa Inversa del VIH/genética , Seropositividad para VIH/tratamiento farmacológico , Seropositividad para VIH/virología , VIH-1/clasificación , VIH-1/genética , Humanos , Masculino , ARN Viral/sangre , Insuficiencia del Tratamiento
17.
J Cardiovasc Electrophysiol ; 19(7): 673-8, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18284494

RESUMEN

INTRODUCTION: Pulmonary vein stenosis (PVS) is a rare but significant complication of pulmonary vein isolation (PVI). Dilation and stent angioplasty have been described but not compared. METHODS AND RESULTS: All percutaneous interventions for PVS complicating PVI between December 2000 and March 2007 were reviewed. Acute success, defined as post-intervention stenosis or=10 mm in diameter had lower restenosis than smaller stents. Risk factors for restenosis included small reference vessel diameter and longer time from PVI to intervention for PVS. All but two patients experienced improvement (n = 10) or resolution of symptoms (n = 22). The mean percent stenosis decreased from 82% to 21% for the entire cohort and mean flow to the lung quadrant increased from 10% to 17%. CONCLUSION: Stent angioplasty results in less restenosis than dilation, particularly for stents >or=10 mm. Early referral may improve long-term patency by minimizing reference vessel atrophy. Most patients with PVS post-PVI can be improved symptomatically with catheter intervention.


Asunto(s)
Angioplastia de Balón , Prótesis Vascular , Ablación por Catéter/efectos adversos , Venas Pulmonares/cirugía , Enfermedad Veno-Oclusiva Pulmonar/etiología , Enfermedad Veno-Oclusiva Pulmonar/cirugía , Stents , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
18.
J Endocrinol Invest ; 31(11): 1008-13, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19169058

RESUMEN

OBJECTIVE: To evaluate the role of non-invasive dynamic tests in the diagnosis and differential diagnosis of Cushing's syndrome (CS). METHODS: We studied laboratory features of 74 patients with endogenous CS, subdivided as follows: 46 (62.1%) with Cushing's disease (CD), 21 (28.3%) with an adrenal tumor, and 7 (9.5%) with ectopic ACTH syndrome (EAS). RESULTS: In 100% of cases of CS we found serum cortisol levels greater than 1.8 microg/dl after low-dose dexamethasone suppression tests (LDDST), as well as elevation of midnight serum or salivary cortisol. However, urinary free cortisol was normal in 11.5% of patients. ACTH levels were suppressed in patients with adrenal tumors, normal or high in CD and invariably increased in EAS. After the 8-mg overnight dexamethasone suppression test (HDDST), serum cortisol suppression >50% was observed in 79.5% of cases of CD and in 28.6% of subjects with EAS, whereas cortisol suppression >80% was only found in CD. After stimulation with CRH or desmopressin an ACTH rise > or =35% occurred in 86.5% of individuals with CD and 14.3% of those with EAS, whereas an ACTH rise > or =50 achieved 100% specificity. Moreover, the combination of serum cortisol suppression >50% after HDDST and an ACTH increase > or =35% after the administration of CRH or desmopressin only occurred in CD. CONCLUSION: Our findings demonstrate that LDDST had 100% sensitivity for the diagnosis of CS and that HDDST and stimulation tests with CRH or desmopressin may be very useful for confirmation of CS etiology when analyzed together or when more stringent cut-offs are used.


Asunto(s)
Síndrome de ACTH Ectópico/diagnóstico , Síndrome de Cushing/diagnóstico , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Hormona Liberadora de Corticotropina , Desamino Arginina Vasopresina , Dexametasona , Diagnóstico Diferencial , Humanos , Hidrocortisona/sangre , Imagen por Resonancia Magnética , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/diagnóstico , Hipófisis/patología , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Saliva/química , Sensibilidad y Especificidad
19.
Lett Appl Microbiol ; 47(1): 12-8, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18498318

RESUMEN

AIMS: The aim of this study was to determine the genetic variability in Aspergillus flavus populations from Brazil nut and cashew and develop a polymerase chain reaction (PCR) detection method. METHODS AND RESULTS: Chomatography analysis of 48 isolates identified 36 as aflatoxigenic (75%). One hundred and forty-one DNA bands were generated with 11 random amplified polymorphic DNA (RAPD) primers and analysed via unweighted pair group analysis, using arithmetic means (UPGMA). Isolates grouped according to host, with differentiation of those from A. occidentale also according to geographical origin. Aspergillus flavus-specific PCR primers ASPITSF2 and ASPITSR3 were designed from ribosomal DNA internal transcribed spacers (ITS 1 and 2), and an internal amplification control was developed, to prevent false negative results. Specificity to only A. flavus was confirmed against DNA from additional aspergilli and other fungi. CONCLUSIONS: RAPD-based characterization differentiated isolates according to plant host. The PCR primer pair developed showed specificity to A. flavus, with a detection limit of 10 fg. SIGNIFICANCE AND IMPACT OF THE STUDY: Genetic variability observed in A. flavus isolates from two Brazilian agroecosystems suggested reproductive isolation. The PCR detection method developed for A. flavus represents progress towards multiplex PCR detection of aflatoxigenic and nonaflatoxigenic strains in Hazard Analysis Critical Control Point systems.


Asunto(s)
Aspergillus flavus/aislamiento & purificación , ADN Ribosómico/análisis , Técnicas de Tipificación Micológica , Técnica del ADN Polimorfo Amplificado Aleatorio/métodos , Aflatoxinas/análisis , Aflatoxinas/biosíntesis , Aflatoxinas/genética , Anacardium/microbiología , Aspergillus flavus/genética , Bertholletia/microbiología , Brasil , ADN de Hongos/análisis , ADN Ribosómico/genética
20.
Genet Mol Res ; 7(1): 161-76, 2008 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-18393220

RESUMEN

Cytogenetic and random amplified polymorphic DNA analyses carried out in the species Leptodactylus podicipinus, L. ocellatus, L. labyrinthicus, and L. fuscus from rural and urban habitats of the northwest region of São Paulo State, Brazil, showed that the karyotypes (2n = 22), constitutive heterochromatin distribution and nucleolus organizer region (NOR) location did not differ between the populations from the two environments. The in situ hybridization with an rDNA probe confirmed the location of the NORs on chromosome 8 revealing an in tandem duplication of that region in one of the chromosomes of L. fuscus. DAPI showed that part of the C-band-positive heterochromatin is rich in AT, including that in the proximity the NORs in L. podicipinus and L. ocellatus. The molecular analyses showed that the two populations (urban and rural) of L. podicipinus and L. fuscus are similar from a genetic point of view. The urban and rural populations of species L. ocellatus and L. labyrinthicus showed differences in genetic structures, probably due to urbanization which interferes with the dispersion of those frogs. The marked differences observed between the two populations of L. ocellatus can be representing the cryptic condition of the species. Unweighted pair-group method of analysis and genetic distance analysis detected the genetic proximity between L. ocellatus and L. fuscus. The results indicate that there was no reduction in the genetic diversity in the populations from the urban environment; however, the survival of these frogs would not be guaranteed in the case of an increase in human impact especially for populations of L. labyrinthicus and L. ocellatus.


Asunto(s)
Anuros/genética , Ambiente , Genética de Población , Polimorfismo Genético , Animales , Brasil , Citogenética , Heterocromatina , Humanos , Cariotipificación , Región Organizadora del Nucléolo , Población Rural , Población Urbana
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