RESUMEN
Cannabidiol (CBD) suffers from poor oral bioavailability due to poor aqueous solubility and high metabolism, and is generally administered in liquid lipid vehicles. Solid-state formulations of CBD have been developed, but their ability to increase the oral bioavailability has not yet been proven in vivo. Various approaches are investigated to increase this bioavailability. This study aimed to demonstrate the enhancement of the oral bioavailability of oral solid dosage forms of amorphous CBD and lipid-based CBD formulation compared to crystalline CBD. Six piglets received the three formulations, in a cross-over design. CBD and 7 - COOH - CBD, a secondary metabolite used as an indicator of hepatic degradation, were analyzed in plasma. A 10.9-fold and 6.8-fold increase in oral bioavailability was observed for the amorphous and lipid formulations, respectively. However, the lipid-based formulation allowed reducing the inter-variability when administered to fasted animals. An entero-hepatic cycle was confirmed for amorphous formulations. Finally, this study showed that the expected protective effect of lipids against hepatic degradation of the lipid-based formulation did not occur, since the ratio CBD/metabolite was higher than that of the amorphous one.
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Disponibilidad Biológica , Cannabidiol , Lípidos , Animales , Cannabidiol/farmacocinética , Cannabidiol/administración & dosificación , Cannabidiol/sangre , Cannabidiol/química , Porcinos , Administración Oral , Lípidos/química , Estudios Cruzados , Hígado/metabolismo , Composición de Medicamentos , Solubilidad , Química Farmacéutica/métodos , MasculinoRESUMEN
We herein report two cases of cathinone intoxication. The first case is about a drug addict who was admitted to the emergency room after the injection of an unknown compound. He presented with tachycardia, palpitations, mydriasis, dyspnea, dizziness, headache and nausea. After leaving the hospital against medical advice, he returned the next day with police escort, presenting aggressiveness and agitation signs. One month later, he returned one more time for sleeping disorders, hallucinations and anxiety. He was finally transferred for his 21st detoxification treatment. The second case concerns a man who was wandering the streets and tried to escape when police officers called him. He confessed to snorting of N-ethylpentedrone and was admitted with severe agitation including delusion of persecution, tachycardia, mydriasis and fever. Because of renal failure, rhabdomyolysis and metabolic acidosis, he was transferred to the intensive care unit where he manifested worsening of the symptoms, turning into coma. He was intubated for 3 days before a complete resolution of the symptoms. A screening was performed by high-resolution mass spectrometry followed by quantifications made by high-performance liquid chromatography coupled with a diode array detector. In the first case, alpha-pyrrolidinohexiophenone was identified only during the first two admissions. However, as plenty of other psychotropic substances were also found, the cathinone alone could not be held directly responsible for the symptoms. In the second case, more than 2,000 ng/mL of N-ethylpentedrone was found without any decrease in the next 17 h, underlining the long half-life of this compound. Unlike the first case, symptoms could be clearly attributed to the cathinone. In conclusion, cathinones can be found on the Belgian illicit drug market, with various routes of administration and clinical consequences. In these two case reports, some common points were observed initially. However, one patient was finally able to leave the hospital without any treatment, whereas the other would most likely have died without intensive care.
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Drogas Ilícitas , Midriasis , Humanos , Masculino , Cathinona Sintética , Bélgica , Servicio de Urgencia en HospitalRESUMEN
The goal of the article was to provide some clinical recommendations for a secure use of lithium. We described the mechanism of action of lithium, that acts as a mood stabilizer but also has anti-suicidal and neuroprotective effects. We also described the toxics effects of lithium and the toxicological tools that help to prevent and to treat those effects. We concluded that lithium remains a first choice for the treatment of bipolar disorders.
L'article fournit des recommandations cliniques pour utiliser le lithium de façon efficace et sûre. Nous décrivons les mécanismes d'action du lithium, stabilisateur de l'humeur aux propriétés antisuicidaires et neuroprotectrices. Nous détaillons les effets toxiques du lithium et les outils de toxicologie clinique qui permettent de les prévenir et de les diagnostiquer. Le lithium reste le traitement de référence des troubles bipolaires.
Asunto(s)
Trastorno Bipolar , Litio/efectos adversos , Psicotrópicos , Trastorno Bipolar/tratamiento farmacológico , Humanos , Psicotrópicos/efectos adversos , Medición de RiesgoRESUMEN
To recognize an alcoholic subject is a frequent request, in a medical or forensic setting. The reasons to determine the alcoholic status of an individual are many and various. Amongst the most frequent are : to decide on the origin of liver or neurological disease, put and maintain a liver transplantation candidate on a waiting list, identify the alcoholic worker to prevent work-related accidents, or evaluate the possible risk an alcoholic individual represents, for road safety or for parental custody. The specific alcohol consumption biological markers combined with clinical and psychological examinations are the best tools to identify the individuals with a problematic consumption. The use of markers belongs to the recommended actions to support patients undergoing treatment for alcoholism. It is mandatory in various situations to distinguish between the teetotaler, the moderate or problematic drinkers. Different biomarkers are described here to allow practitioners to adapt their prescriptions.
Reconnaître un sujet alcoolique est une requête fréquente, que ce soit dans un cadre médical ou médico-légal. Les besoins de connaître le statut alcoolique d'un individu sont multiples et variés. Parmi les plus fréquents, on peut citer : se prononcer sur l'origine d'une pathologie hépatique ou neurologique, inscrire et maintenir un candidat à une greffe hépatique sur une liste d'attente, identifier le travailleur alcoolique afin de prévenir les accidents de travail, ou encore apprécier le risque éventuel qu'un individu alcoolique représente, que ce soit derrière son volant ou dans le contexte d'une garde parentale. Les marqueurs biologiques spécifiques de la consommation d'alcool, combinés aux examens cliniques et psychologiques, constituent à ce jour les meilleurs outils pour identifier les individus à consommation problématique. L'utilisation de ces indicateurs fait également partie des mesures prônées pour l'accompagnement des sujets en cure de désintoxication. Distinguer le sujet abstinent, consommateur social (dit modéré) ou problématique peut, dès lors, s'avérer essentiel dans diverses situations. Les différents biomarqueurs disponibles à ce jour sont discutés dans cet article afin de permettre aux cliniciens une prescription adaptée aux investigations à mener.
Asunto(s)
Consumo de Bebidas Alcohólicas , Alcoholismo , Biomarcadores , Hepatopatías Alcohólicas , Trasplante de Hígado , Biomarcadores/sangre , HumanosRESUMEN
Electronic cigarettes (e-cigarettes) are presented as a healthier alternative to tobacco smoking. They are designed to contain a solution which is heated to produce an aerosol inhaled by the user. The liquid is mainly composed of propylene glycol, glycerol, flavours and, in some cases, nicotine. Except for nicotine, which can be fatal when ingested at high dose, these components are generally considered as safe. However, the potential effect of long term exposure to inhaled propylene glycol is unknown at this time. As an advantage, toxic compounds responsible for the noxiousness of tobacco smoking (nitrosamines, metals, formaldehyde, carbon monoxide ) are either absent, or present in the smoke of e-cigarette at levels far less compared to conventional cigarette smoke. Finally, efficacy of e-cigarette as a tool for smoking cessation stays to be proven.
La cigarette électronique, aussi appelée e-cigarette, est présentée comme une alternative au tabagisme qui serait moins nocive pour la santé. Son fonctionnement repose sur la conversion d'un liquide en vapeur, sous l'action de la chaleur générée par un filament présent dans un atomiseur. Le liquide est majoritairement composé de propylène glycol et/ou de glycérine, utilisé(s) pour produire l'effet de fumée, auxquels s'ajoutent des arômes et, éventuellement, de la nicotine. A l'exception de cette dernière, potentiellement létale lorsqu'elle est ingérée à haute dose, ces constituants sont généralement reconnus comme sans danger. Cependant, les conséquences d'une inhalation chronique de propylène glycol sont méconnues. Avantageusement, les composés qui rendent la cigarette traditionnelle particulièrement nuisible nitrosamines, formaldéhyde, métaux, monoxyde de carbone, - sont soit absents, soit présents en faible quantité dans la vapeur d'une e-cigarette, sans comparaison avec les taux mesurés dans la fumée d'une cigarette conventionnelle. Il en résulte un profil de toxicité rassurant pour la e-cigarette, bien que son efficacité dans le sevrage tabagique reste à démontrer.
Asunto(s)
Sistemas Electrónicos de Liberación de Nicotina , Propilenglicol/toxicidad , HumanosRESUMEN
OBJECTIVES: The objective of the study was to describe 'the results of the blood alcohol determinations made on drivers from the Liege area between 2007 and 2012. METHODS: The results were interpreted according to the sex, to the age, to the circumstances and temporal variation of the test. Statistical analysis was performed using R® software. RESULTS: 2725 determinations were done, mainly after crashes. The mean blood alcohol concentration (BAC) was 1.69 g/L, and 2132 drivers were above the legal threshold. A majority of offenders were men, but the mean BAC did not differ significantly between men and women. A correlation between age and mean BAC can be observed on the positive cases. Lowest and highest mean BACs are observed during the daytime and during the night, respectively, but no significant difference can be observed between the week and the weekend. Finally, no significant difference in BAC was observed over years.
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Nivel de Alcohol en Sangre , Conducir bajo la Influencia/estadística & datos numéricos , Adolescente , Adulto , Distribución por Edad , Anciano , Bélgica/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distribución por Sexo , Adulto JovenRESUMEN
AIMS: To describe a new molecular technique for the assessment of fungal diversity in the air. METHODS AND RESULTS: Air samples were collected every week in a henhouse in France during a 15-week period. After air sampling, the collecting membrane was diluted, and the liquid was used for subsequent cultivation and molecular analysis: PCR-temperature temporal gradient electrophoresis (TTGE), which has already been used for the identification of fungal species in air samples and PCR-denaturing high-performance liquid chromatography (D-HPLC), a new technique for the analysis of complex microbial populations. D-HPLC profiles were reproducible from run-to-run, and several fungal organisms could be identified at the species level by sequencing. CONCLUSIONS: PCR-D-HPLC enabled the identification of fungal species (both Ascomycota and Basidiomycota) that may be encountered in air. The new technique allowed the detection of more fungal species than did the PCR-TTGE technique. However, some fungal species were detected only by PCR-TTGE, suggesting that PCR-D-HPLC and PCR-TTGE are complementary. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR-D-HPLC represents a considerable saving in time over currently available procedures for detection and identification of fungal organisms in air. However, the fungal diversity detected by PCR-D-HPLC or by PCR-TTGE was lower than that revealed by culture.
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Microbiología del Aire , Cromatografía Líquida de Alta Presión/métodos , Monitoreo del Ambiente/métodos , Hongos/aislamiento & purificación , ADN de Hongos/química , Hongos/genética , Desnaturalización de Ácido Nucleico , Reacción en Cadena de la PolimerasaRESUMEN
Parasites are increasingly used to complement the evolutionary and ecological adaptation history of their hosts. Pneumocystis pathogenic fungi, which are transmitted from host-to-host via an airborne route, have been shown to constitute genuine host markers of evolution. These parasites can also provide valuable information about their host ecology. Here, we suggest that parasites can be used as phylogeographic markers to understand the geographical distribution of intra-specific host genetic variants. To test our hypothesis, we characterised Pneumocystis isolates from wild bats living in different areas. Bats comprise a wide variety of species; some of them are able to migrate. Thus, bat chorology and migration behaviour can be approached using Pneumocystis as phylogeographic markers. In the present work, we find that the genetic polymorphisms of bat-derived Pneumocystis are structured by host chorology. Therefore, Pneumocystis intra-specific genetic diversity may constitute a useful and relevant phylogeographic tool.
Asunto(s)
Quirópteros/microbiología , Variación Genética , Geografía , Pneumocystis/genética , Animales , Argentina , Quirópteros/clasificación , Francia , Guyana Francesa , México , Filogenia , Pneumocystis/clasificación , Pneumocystis/aislamiento & purificación , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
Parasites are increasingly used to complement the evolutionary and ecological adaptation history of their hosts. Pneumocystis pathogenic fungi, which are transmitted from host-to-host via an airborne route, have been shown to constitute genuine host markers of evolution. These parasites can also provide valuable information about their host ecology. Here, we suggest that parasites can be used as phylogeographic markers to understand the geographical distribution of intra-specific host genetic variants. To test our hypothesis, we characterised Pneumocystis isolates from wild bats living in different areas. Bats comprise a wide variety of species; some of them are able to migrate. Thus, bat chorology and migration behaviour can be approached using Pneumocystis as phylogeographic markers. In the present work, we find that the genetic polymorphisms of bat-derived Pneumocystis are structured by host chorology. Therefore, Pneumocystis intra-specific genetic diversity may constitute a useful and relevant phylogeographic tool.
Asunto(s)
Animales , Quirópteros/microbiología , Variación Genética , Geografía , Pneumocystis/genética , Argentina , Quirópteros/clasificación , Francia , Guyana Francesa , México , Filogenia , Pneumocystis/clasificación , Pneumocystis/aislamiento & purificación , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
Over the past 50 years, many advances in our understanding of the general principles controlling gene expression during hematopoiesis have come from studying the synthesis of hemoglobin. Discovering how the alpha- and beta-globin genes are normally regulated and documenting the effects of inherited mutations that cause thalassemia have played a major role in establishing our current understanding of how genes are switched on or off in hematopoietic cells. Previously, nearly all mutations causing thalassemia have been found in or around the globin loci, but rare inherited and acquired trans-acting mutations are being found more often. Such mutations have demonstrated new mechanisms underlying human genetic disease. Furthermore, they are revealing new pathways in the regulation of globin gene expression that, in turn, may open up new avenues for improving the management of patients with common types of thalassemia.
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Regulación de la Expresión Génica , Globinas/genética , Talasemia/terapia , Cromosomas Humanos Par 11/genética , Cromosomas Humanos Par 16/genética , ADN Helicasas/genética , ADN Helicasas/fisiología , Epigénesis Genética/genética , Regulación del Desarrollo de la Expresión Génica , Globinas/biosíntesis , Neoplasias Hematológicas/genética , Hematopoyesis/genética , Humanos , Mutación , Síndromes Mielodisplásicos/genética , Proteínas Nucleares/genética , Proteínas Nucleares/fisiología , Secuencias Reguladoras de Ácidos Nucleicos , Telómero/genética , Talasemia/genética , Proteína Nuclear Ligada al Cromosoma X , Talasemia alfa/genéticaRESUMEN
Between June 1995 and November 1998, 228 patients with relapsing-remitting Multiple Sclerosis started treatment with glatiramer acetate (Copaxone) 20 mg once daily in the frame of a "compassionate use" protocol in 15 Belgian centers. Following an average treatment period of 5.8 years, treating neurologists were requested to fill in follow-up forms indicating neurological disability status and side effects during the previous 6 months. These data were available for 134 patients. In this group, the Expanded Disability Status Scale (EDSS) improved in 26.3% of patients. An additional 36.8% of patients remained neurologically stable. The Ambulation Index (AI) showed similar results: 12.5% of patients improved, 50% of patients remained stable, and 37.5% worsened. Only 10% of patients dropped out due to several reasons. The adverse events occurring in the period preceding the follow-up survey were non-serious and consistent with the current product information of glatiramer acetate. Among the 94 patients no longer followed-up in the compassionate program, reasons for lost to follow-up were obtained for 63; most of them (41) had stopped GA treatment or switched to another disease-modifying treatment. Overall these results are very similar to the ones reported in the extension study of the pivotal trial (Johnson et al., 2000), and indicate that patients treated with glatiramer acetate have a better outcome than expected on the basis of the natural course of the disease. Despite limitations of the study design, this report confirms the sustained efficacy of glatiramer acetate in reducing the disease progression in patients with relapsing-remitting multiple sclerosis treated in day-to-day clinical practice.
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Inmunosupresores/administración & dosificación , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Péptidos/administración & dosificación , Adolescente , Adulto , Bélgica , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Acetato de Glatiramer , Encuestas Epidemiológicas , Humanos , Inmunosupresores/efectos adversos , Luxemburgo , Masculino , Persona de Mediana Edad , Esclerosis Múltiple Recurrente-Remitente/fisiopatología , Países Bajos , Cooperación del Paciente , Péptidos/efectos adversos , Prevención Secundaria , Factores de Tiempo , Resultado del TratamientoRESUMEN
We report a case of eumycetoma due to Cladophialophora bantiana in a 3-year-old male Siberian Husky living in France. The dog presented a tumefaction on the thorax and deformity of the second and third subjacent ribs, which were surgically removed. Macroscopic black granules were visible on the ribs, and direct microscopic examination revealed their fungal origin. Cultures yielded pure colonies of C. bantiana. The identification of the causative agent was confirmed after amplification and sequence analysis of fungal internal transcribed spacers 1 and 2 and 5.8S ribosomal DNA regions. Surgery and antifungal treatment with oral itraconazole associated with flucytosine allowed apparent cure after a 10-month follow-up. Envenomation with pine processionary caterpillars (Thaumetopoea pityocampa) and subsequently intensive corticotherapy were considered as possible predisposing factors. This is, to the best of our knowledge, the first case in which C. bantiana is identified as the causative agent of eumycetoma.
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Ascomicetos/aislamiento & purificación , Enfermedades de los Perros/microbiología , Micetoma/veterinaria , Animales , Ascomicetos/clasificación , Ascomicetos/genética , ADN Ribosómico/análisis , ADN Espaciador Ribosómico/análisis , Perros , Masculino , Micetoma/microbiología , ARN Ribosómico 5.8S/genéticaRESUMEN
Cytological examination using the tape-strip technique and fungal culture using contact plates with modified Dixon's medium were compared to evaluate the carriage of Malassezia yeasts on four cutaneous sites (left pinna, umbilical region, axilla and perianal area) in adult Basset Hounds. Twenty animals were included in the study. High numbers of Malassezia were isolated from at least one area in 100% of the animals. The frequencies of isolation and population sizes differed significantly according to anatomical location. They were greater on the pinna, followed by the umbilical area, axilla and perianal area. Fungal culture was more sensitive than cytology for the isolation of Malassezia yeasts. Frequencies of isolation were greater using this method, but population sizes were constantly smaller than with cytology.
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Dermatomicosis/veterinaria , Enfermedades de los Perros/microbiología , Perros/microbiología , Malassezia/aislamiento & purificación , Canal Anal/microbiología , Animales , Axila/microbiología , Cruzamiento , Técnicas de Cultivo de Célula/métodos , Dermatomicosis/microbiología , Oído Externo/microbiología , Femenino , Masculino , Ombligo/microbiologíaRESUMEN
The performance of the dermatophyte test medium (DTM) RapidVet-D was assessed using hair samples collected from experimentally infected guinea pigs. Three dermatophyte species were included in the study: Microsporum canis, Trichophyton mentagrophytes and Trichophyton equinum. DTM substrates were inoculated with infected hairs and scales, incubated at 18, 21, 24, 27 or 37 degrees C and examined daily for 15 days. The rapidity of colour change was clearly related to the incubation temperature and to the number of infected hairs deposited on the reactive substrates. With the optimum incubation temperature 27 degrees C, a systematic colour change could be observed only a few days post-inoculation: 3 days with M. canis infected hairs, 4 days with T. equinum and 5 days with T. mentagrophytes.
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Dermatomicosis/veterinaria , Enfermedades de los Perros/diagnóstico , Microsporum/crecimiento & desarrollo , Trichophyton/crecimiento & desarrollo , Animales , Medios de Cultivo , Técnicas de Cultivo/veterinaria , Dermatomicosis/diagnóstico , Dermatomicosis/microbiología , Enfermedades de los Perros/microbiología , Perros , Cobayas , Masculino , Microsporum/aislamiento & purificación , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Organismos Libres de Patógenos Específicos , Temperatura , Trichophyton/aislamiento & purificaciónRESUMEN
AIMS: The present study describes a system based on PCR and restriction endonuclease analysis (REA) to distinguish the seven currently recognized Malassezia species. METHODS AND RESULTS: Fifty-five representative yeast isolates were examined. A single primer pair was designed to amplify the large subunit ribosomal RNA (LSU rRNA) gene of the seven Malassezia species, and identification was achieved by digestion of the PCR products with three restriction endonucleases: BanI, HaeII and MspI. A specific restriction endonuclease analysis pattern was determined for each species investigated. Moreover, PCR-REA allowed the detection and characterization of mixtures of several Malassezia species. CONCLUSION: PCR-REA of only the LSU rRNA gene is a reliable and rapid method to distinguish all Malassezia species. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR-REA represents a considerable saving in time over currently available identification procedures. This method should be evaluated on clinical material directly.
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Malassezia/clasificación , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Desoxirribonucleasa HpaII/metabolismo , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , ARN Ribosómico 28S/genéticaRESUMEN
The aim of this study was to improve our knowledge about the taxonomy and phylogeny of the family Saprolegniaceae, a group of water molds including several pathogens of plants, fish and crustacea. ITS and LSU rDNA were sequenced for representatives of forty species corresponding to ten genera (Achlya, Aphanomyces, Brevilegnia, Dictyuchus, Leptolegenia, Plectospira, Pythiopsis, Saprolegnia, Thraustotheca). Phenetic and cladistic analyses were then carried out. The species Brevilegnia bispora does not appear to belong to the family Saprolegniaceae. Plectospira myrianda clusters with Aphanomyces spp. and they constitute an ancestral group. (Thraustotheca clavata is closely related to the eccentric species of the genus Achlya. The genus Achlya appears polyphyletic, corroborating more or less the three known subgroups, defined by their sexual spore type (eccentric, centric and subcentric). The achlyoid type of spore dehiscence, shared by Aphanomyces and Achlya genera, is shown to be an ancestral character. The saprolegnioid, dictyoid and thraustothecoid types of spore dehiscence are derived characters but their relative evolutionary positions are not resolved.
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Oomicetos/clasificación , Clasificación , ADN Intergénico , ADN Ribosómico , Variación Genética , Técnicas de Tipificación Micológica , Oomicetos/genética , Filogenia , Alineación de SecuenciaRESUMEN
The human alpha-globin gene complex includes three functional globin genes (5'-zeta2-alpha2-alpha1-3') regulated by a common positive regulatory element named HS-40 displaying strong erythroid-specific enhancer activity. How this enhancer activity can be shared between different promoters present at different positions in the same complex is poorly understood. To address this question, we used homologous recombination to target the insertion of marker genes driven by cytomegalovirus or long terminal repeat promoters in both possible orientations either upstream or downstream from the HS-40 region into the single human alpha-globin gene locus present in hybrid mouse erythroleukemia cells. We also used CRE recombinase-mediated cassette exchange to target the insertion of a tagged alpha-globin gene at the same position downstream from HS-40. All these insertions led to a similar decrease in the HS-40-dependent transcription of downstream human alpha-globin genes in differentiated cells. Interestingly, this decrease is associated with the strong activation of the proximal newly inserted alpha-globin gene, whereas in marked contrast, the transcription of the non-erythroid marker genes remains insensitive to HS-40. Taken together, these results indicate that the enhancer activity of HS-40 can be trapped by non-erythroid promoters in both upstream and downstream directions without necessarily leading to their own activation.
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Elementos de Facilitación Genéticos , Globinas/genética , Globinas/metabolismo , Animales , Núcleo Celular/metabolismo , Cromosomas Humanos Par 16 , Citomegalovirus/genética , ADN Nucleotidiltransferasas/metabolismo , Humanos , Ratones , Modelos Genéticos , Mutagénesis Insercional , Plásmidos/metabolismo , Regiones Promotoras Genéticas , Recombinación Genética , Ribonucleasas/metabolismo , Secuencias Repetidas Terminales , Transcripción Genética , Células Tumorales CultivadasRESUMEN
The problem of blood flow through stenoses is solved using the incompressible generalized Newtonian model. The Herschel-Bulkley, Bingham and power-law fluids are incorporated. The geometry corresponds to a rigid circular tube with a partial occlusion. Calculations are performed by a Galerkin finite-element method. For the pulsatile case, a predictor-corrector time marching scheme is used with an adaptive time step. Results are obtained for steady and pulsatile physiological flows. Computations show that the memory effects taken into account in the model affect deeply the flow compared with Newtonian reference case. The disturbances are stronger by their vorticity intensity and persist after the geometrical obstacle. This is especially true for severe stenoses.
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Arterias/fisiopatología , Fenómenos Fisiológicos Sanguíneos , Modelos Cardiovasculares , Constricción Patológica , Humanos , Flujo Pulsátil , Enfermedades Vasculares/fisiopatologíaRESUMEN
The problem of blood flow through a stenosis is solved using the incompressible Navier-Stokes equations in a rigid circular tube presenting a partial occlusion. Calculations are based on a Galerkin finite element method. The time marching scheme employs a predictor-corrector technique using a variable time step. Results are obtained for steady and physiological pulsatile flows. Computational experiments analyse the effect of varying the degree of stenosis, the stricture length, the Reynolds number and Womersley number. The method gives results which agree well with previous computations for steady flows and experimental findings for steady and pulsatile flows.