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1.
Open Microbiol J ; 10: 140-9, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27651847

RESUMEN

Qualitative expression of dissimilative sulfite reductase (dsrA), a key gene in sulfate reduction, and sulfide:quinone oxidoreductase (sqr), a key gene in sulfide oxidation was investigated. Neither of the two could be amplified from mRNA retrieved with Niskin bottles but were amplified from mRNA retrieved by the Deep SID. The sqr and sqr-like genes retrieved from the Cariaco Basin were related to the sqr genes from a Bradyrhizobium sp., Methylomicrobium alcaliphilum, Sulfurovum sp. NBC37-1, Sulfurimonas autotrophica, Thiorhodospira sibirica and Chlorobium tepidum. The dsrA gene sequences obtained from the redoxcline of the Cariaco Basin belonged to chemoorganotrophic and chemoautotrophic sulfate and sulfur reducers belonging to the class Deltaproteobacteria (phylum Proteobacteria) and the order Clostridiales (phylum Firmicutes).

2.
Cranio ; 34(1): 29-37, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26856384

RESUMEN

OBJECTIVES/HYPOTHESIS: This study assessed the kinesiographic recordings of jaw movements during reading a text in Galician and Spanish language. STUDY DESIGN: Cross-sectional blind study. METHODS: A homogeneous healthy group of 25 normal stomatognathic system and native Galician participants was studied. Frontal and parasagittal plane recordings of the intraborder lateral jaw movements and during reading Galician and Spanish texts were recorded using a calibrated jaw-tracking device, kinesiograph. RESULTS: Although movements were similar in both languages, a greater retrusion of the jaw in the Spanish language was shown; moreover, a tendency exists for a left-side motion envelope in this right-handedness preference sample. CONCLUSIONS: This study supports the hypothesis that speech is controlled by the central nervous system rather than by peripheral factors and that the hemispheric dominance influences the asymmetry of the speech envelope.


Asunto(s)
Registro de la Relación Maxilomandibular/instrumentación , Registro de la Relación Maxilomandibular/métodos , Mandíbula/fisiología , Movimiento , Pruebas de Articulación del Habla , Patología del Habla y Lenguaje/métodos , Habla/fisiología , Adolescente , Estudios Transversales , Femenino , Lateralidad Funcional/fisiología , Hispánicos o Latinos , Humanos , Terapia del Lenguaje/instrumentación , Terapia del Lenguaje/métodos , Masculino , Mandíbula/inervación , Movimiento (Física) , Sistema Nervioso , Rango del Movimiento Articular , Lectura , Patología del Habla y Lenguaje/instrumentación , Estadísticas no Paramétricas , Sistema Estomatognático/inervación , Sistema Estomatognático/patología , Articulación Temporomandibular/fisiología , Adulto Joven
3.
FEMS Microbiol Ecol ; 91(9): fiv088, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26209697

RESUMEN

Massively parallel tag sequencing was applied to describe the bacterial diversity in the redox transition and anoxic zones of the Cariaco Basin. In total, 14 samples from the Cariaco Basin were collected over a period of eight years from two stations. A total of 244 357 unique bacterial V6 amplicons were sequenced. The total number of operational taxonomic units (OTUs) found in this study was 4692, with a range of 511-1491 OTUs per sample. Approximately 95% of the OTUs found in the redox transition zone and anoxic layers of Cariaco are represented by less than 50 amplicons suggesting that only about 5% of the bacterial OTUs are responsible for the bulk of the microbial processes in the basin redox transition and anoxic zones. The same dominant OTUs were observed across all eight years of sampling although periodic fluctuations in their proportion were apparent. No distinctive differences were observed between the bacterial communities from the redox transition and anoxic layers of the Cariaco Basin water column. The largest proportion of amplicons belongs to Gammaproteobacteria represented mostly by sulfide oxidizers, followed by Marine Group A (originally described as SAR406; Gordon and Giovannoni 1996), a group of uncultured bacteria hypothesized to be involved in metal reduction, and sulfate-reducing Deltaproteobacteria. Gammaproteobacteria, Deltaproteobacteria and Marine Group A make up 67-90% of all V6 amplicons sequenced in this study. This strongly suggests that the basin's microbial communities are actively involved in the sulfur-related metabolism and coupling of the sulfur and carbon cycles. According to detrended canonical correspondence analysis, ecological factors such as chemoautotrophy, nitrate and oxidized and reduced sulfur compounds influence the structuring and distribution of the Cariaco microbial communities.


Asunto(s)
Anaerobiosis/fisiología , Biodiversidad , Deltaproteobacteria/genética , Gammaproteobacteria/genética , Oxidación-Reducción , Agua de Mar/microbiología , Secuencia de Bases , Carbono/metabolismo , ADN Bacteriano , Deltaproteobacteria/aislamiento & purificación , Deltaproteobacteria/metabolismo , Gammaproteobacteria/aislamiento & purificación , Gammaproteobacteria/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Nitratos/análisis , Análisis de Secuencia de ADN , Azufre/metabolismo , Venezuela
4.
Int J Pharm ; 478(1): 258-267, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25448587

RESUMEN

Large oral doses of ACZ lower the intraocular pressure (IOP), but usually lead to a multitude of systemic side effects, including gastrointestinal upset. The present study was undertaken to evaluate the effect of ACZ on the histological structure of rat duodenal mucosa and to assess a possible protective role of the complex formation of ACZ with HP-ß-CD, either separately or in combination with a third compound, on the gut epithelial layer by histological and ultrastructural examinations of sections of rat duodenum exposed to ACZ or its formulations. In addition, the transport process of ACZ and its binary or ternary complexes across the duodenal mucosa by means of the single-pass intestinal perfusion (SPIP) method in rats was evaluated. Evidence was found that ACZ alters intestinal permeability and induces damage to the rat small intestine. In contrast, ACZ-induced intestinal injury may be abrogated by ACZ complexation. In addition, the complexation of ACZ with HP-ß-CD, alone or in combination with a third compound, facilitated significant levels of ACZ uptake across the rat duodenal segment. Ternary complexes of ACZ with HP-ß-CD in combination with TEA (triethanolamine) or calcium ions were found to provide an excellent approach that enabled an increased apparent permeability of ACZ across the duodenal epithelium, with a concomitant ability to preserve the integrity of the gut epithelium from ACZ-induced injury. These results could be useful for the design and development of novel ACZ formulations that can reduce GI toxicity, while still maintaining their essential therapeutic efficacies.


Asunto(s)
Acetazolamida , beta-Ciclodextrinas , 2-Hidroxipropil-beta-Ciclodextrina , Acetazolamida/administración & dosificación , Acetazolamida/química , Acetazolamida/farmacocinética , Acetazolamida/toxicidad , Animales , Calcio/administración & dosificación , Calcio/química , Calcio/farmacocinética , Calcio/toxicidad , Duodeno/efectos de los fármacos , Duodeno/patología , Duodeno/ultraestructura , Etanolaminas/administración & dosificación , Etanolaminas/química , Etanolaminas/farmacocinética , Etanolaminas/toxicidad , Absorción Intestinal , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Mucosa Intestinal/ultraestructura , Masculino , Microscopía Electrónica de Transmisión , Ratas Wistar , beta-Ciclodextrinas/administración & dosificación , beta-Ciclodextrinas/química , beta-Ciclodextrinas/farmacocinética , beta-Ciclodextrinas/toxicidad
5.
Eur J Orthod ; 37(4): 403-11, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25381444

RESUMEN

INTRODUCTION: It is widely accepted that there is a relationship between the cranial base and the development of the nasomaxillary complex (NMC). The objective of the present study was to investigate the morphological relationship between these two anatomical units in skulls that have intentionally been subjected to one of two types of artificial deformity of the cranial vault [artificially deformed skulls (ADS)]. MATERIAL AND METHODS: A geometric morphometry study was performed on lateral cephalometric X-rays of three groups of crania: 32 with anteroposterior (AP) deformity, 17 with circumferential (C) deformity, and 39 with no apparent deformity. RESULTS: The cranial base of the ADS showed marked deformity that produced a restriction of AP growth of the NMC, alterations of the roof of the orbit as a consequence of the rotation of anterior cranial fossa, and nasal protrusion. Pronounced morphological differences were found between the three groups: increased vertical development of the maxilla occurred in both ADS groups due to growth of the alveolar process, and rotation of the maxilla and displacement of the orbital rim was observed in the C group. This confirms that the posterior facial plane is regarded as an axial structure that serves as an interface between the middle cranial base and the NMC (Enlow, D.H. and Hans, M.G. (1996) Essential of Facial Growth. WB Saunders Co., Philadelphia, PA). LIMITATIONS: It is important to take into account that these results have been obtained from an archaeological sample, with all the limitations that this implies such as being a small sample and with no absolute certainty regarding the use of the same type of deforming device within each group. Furthermore, this is a lateral two-dimensional study in which transverse development has not been analysed. CONCLUSIONS: Artificial modification of the shape of the vault has repercussions on the NMC that support the theory of an all-inclusive integration of the different cranial units in normal as well as in restricted development.


Asunto(s)
Anomalías Craneofaciales/patología , Maxilar/anomalías , Nariz/anomalías , Base del Cráneo/anomalías , Proceso Alveolar/crecimiento & desarrollo , Puntos Anatómicos de Referencia/patología , Cefalometría/métodos , Fosa Craneal Media/patología , Humanos , Maxilar/patología , Desarrollo Maxilofacial , Nariz/patología , Hueso Occipital/anomalías , Hueso Occipital/patología , Órbita/patología , Paleopatología , Fosa Pterigopalatina/patología , Rotación , Base del Cráneo/patología , Dimensión Vertical
6.
Cardiol J ; 22(1): 44-51, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-24671899

RESUMEN

BACKGROUND: Clinical practice guidelines recommend ad hoc screening of diabetes in patients admitted for macrovascular disease; however, these recommendations are rarely followed in real practice. This study was undertaken to assess whether impaired glucose metabolism, newly diagnosed after percutaneous coronary intervention (PCI) or known diabetes, provides prognostic information. METHODS: We studied 374 patients who underwent PCI. An oral glucose tolerance test was carried out in the known non-diabetic patients with fasting glucose < 7 mmol/L. RESULTS: Eighty-one percent of the patients presented impaired glucose metabolism, from which 35.3% were previously diagnosed with diabetics, 21.4% were newly detected diabetics, and 24.3% were pre-diabetics. After a mean follow-up of 35.8 ± 13.4 months, only a known history of diabetes was an independent predictor of revascularization (OR = 2.03, p = 0.025), non-fatal acute myocardial infarction (OR = 2.70, p = 0.029) and readmission due to heart failure during the follow-up (OR = 3.82, p = 0.022). CONCLUSIONS: Screening for impaired glucose metabolism after PCI permits the detection of a high proportion of patients with abnormal glucose regulations. However, previously known diabetes remains the only independent predictor of cardiovascular events in the follow-up.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus/etiología , Isquemia Miocárdica/terapia , Intervención Coronaria Percutánea/efectos adversos , Estado Prediabético/etiología , Anciano , Biomarcadores/sangre , Distribución de Chi-Cuadrado , Diabetes Mellitus/sangre , Diabetes Mellitus/diagnóstico , Ayuno/sangre , Femenino , Prueba de Tolerancia a la Glucosa , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/terapia , Humanos , Modelos Logísticos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/etiología , Infarto del Miocardio/terapia , Isquemia Miocárdica/diagnóstico , Oportunidad Relativa , Readmisión del Paciente , Estado Prediabético/sangre , Estado Prediabético/diagnóstico , Valor Predictivo de las Pruebas , Estudios Prospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
7.
J Biomech ; 47(16): 3891-7, 2014 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-25442299

RESUMEN

This study attempted to estimate TMJ loading during incisal loading using a custom load-cell device and surface electromyographic (sEMG) recordings of the main jaw closers to assess the outcome correlation. Study participants were 23 healthy volunteers. The incisal loads having submaximal and mean intensity were recorded using a calibrated electronic load cell; simultaneously, surface electromyography (sEMG) of the right and left masseter and temporalis muscles was recorded. Readings of the resting, clenching in maximal and submaximal intercuspal positions and mean (50%) incisal loads were recorded. Clenching sEMG activity was used as a reference for normalization. The mean (SD) submaximal incisal load recorded was 498 (305.78)N, and the mean at 50% of the submaximal load was 268.93 (147.37)N. Mean (SD) sEMG activity during submaximal clenching was 141.23 (87.76)µV, with no significant differences between the four muscles. During submaximal voluntary incisal loading, the normalized mean sEMG activity was 49.99 (34.54)µV %, and 27.17(15.29)µV % during mean (50%) effort. The incisal load was generated mainly by the masseter muscles, as these showed a positive correlation during mean but not during submaximal effort. In the edge-to-edge jaw position, the mean incisal load effort seems to be physiological, but excessive TMJ loads can be expected from chronic or excessive incisal loading. In conclusion, incisal loads require the activity of the masseter muscles, which show a positive correlation between sEMG activity and effective incisal loads during mean, but not during submaximal, effort, and the masseter muscles are dominant over the temporalis muscles during submaximal incisal biting.


Asunto(s)
Fuerza de la Mordida , Maxilares/fisiología , Músculo Masetero/fisiología , Músculo Temporal/fisiología , Adulto , Electromiografía , Femenino , Voluntarios Sanos , Humanos , Contracción Isométrica , Masculino , Contracción Muscular/fisiología , Fenómenos Fisiológicos Musculoesqueléticos , Soporte de Peso , Adulto Joven
8.
J Electromyogr Kinesiol ; 24(3): 332-40, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24698167

RESUMEN

The use of surface electromyography (sEMG) to identify subjects with chronic temporomandibular disorders (TMD) is controversial. The main objective of this study is to determine the diagnostic accuracy of EMG to differentiate between healthy subjects and those with TMD. This study evaluated 53 individuals with TMD who were referred to the university service and who fulfilled the eligibility criteria during the period of the study. Thirty-eight dental students were also recruited satisfying same eligibility criteria but without TMD. The inclusion criteria were to be fully dentate, have normal occlusion, and be righthanded. The exclusion criteria were periodontal pathology, caries or damaged dental tissues, orthodontic therapy, maxillofacial disease, botulinum A toxin therapy, and psychological disorders. The means of the masseter muscles, right (RM) and left (LM), and temporalis muscles, right (RT) and left (LT), and intraindividual indexes during resting and during clenching were calculated. Raw sEMG activity was used to determine the cutoff points and calculate the diagnostic accuracy of sEMG. The diagnostic accuracy of these variables for a diagnosis of TMD was evaluated by using the Receiver Operating Characteristic (ROC) curve and the area under it (AUC). A new transformed diagnostic variable was obtained by using the Generalized Additive Models (GAM). Optimal cutoff points were obtained where the sensitivity and specificity were similar and by the Youden index. The highest estimated AUC was 0.660 (95% CI 0.605-0.871) corresponding to the rLT variable during rest. When rLT and rACTIVITY (differences divided by sums of temporalis versus masseter muscles) were considered as a linear combination, the AUC increased to 0.742 (95% CI; 0.783-0.934). In conclusion, the raw sEMG evaluation of rest provided moderate sensitivity and specificity to discriminate between healthy individuals and those with TMD. The use of the indexes (mainly assessing the dominance of temporalis over masseter muscles during rest) is strongly recommended to increase the discriminatory capacity of raw sEMG evaluation.


Asunto(s)
Electromiografía/métodos , Músculo Masetero/fisiología , Músculo Masetero/fisiopatología , Músculo Temporal/fisiología , Músculo Temporal/fisiopatología , Trastornos de la Articulación Temporomandibular/diagnóstico , Trastornos de la Articulación Temporomandibular/fisiopatología , Adolescente , Adulto , Área Bajo la Curva , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Valores de Referencia , Sensibilidad y Especificidad , Adulto Joven
9.
Carbohydr Polym ; 98(1): 380-90, 2013 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-23987358

RESUMEN

The effects of binary and ternary systems of acetazolamide (ACZ) with hydroxypropyl-ß-cyclodextrin (HP-ß-CD) alone or with triethanolamine (TEA) on the crystalline properties, dissolution and intraocular pressure (IOP)-lowering effect were investigated. It was found that the crystal structure of ACZ powder could be modified by the processing conditions. Freeze-drying ACZ powder affected not only the particle morphology but also its polymorphic form and the starting ACZ was converted to pure form A upon freeze-drying treatment. Results provided by DSC/TGA, XRPD, SEM and FT-IR suggested the formation of inclusion complexes between ACZ with HP-ß-CD alone or with TEA, obtained by the freeze-drying method and the conversion of the drug into the amorphous state. Binary and ternary systems of ACZ obtained by freeze-drying exhibited significantly enhanced ACZ dissolution rates. The IOP-lowering effects of ACZ and its complexes with HP-ß-CD alone or with TEA were studied in normotensive rabbits. Whereas the maximum IOP-lowering effect (~4 mmHg, ~33%), obtained with these binary and ternary lyophilized ACZ systems occurred at around 90 min, the ternary system exhibited a longer maximum IOP-lowering effect peak compared with that of the binary system. These results are in line with those obtained from the dissolution studies, where the ternary system exhibited longer dissolution times compared to the lyophilized binary one. Results obtained from the dissolution studies, also showed that freeze-drying the native crystalline form of ACZ significantly increased the dissolution rate of ACZ, thus improving the IOP-lowering effect of this drug.


Asunto(s)
Acetazolamida/química , Acetazolamida/farmacología , 2-Hidroxipropil-beta-Ciclodextrina , Animales , Etanolaminas/química , Presión Intraocular/efectos de los fármacos , Conejos , Temperatura , beta-Ciclodextrinas/química
10.
PLoS One ; 8(4): e59980, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23593156

RESUMEN

BACKGROUND: Temporomandibular disorders are the most common cause of chronic orofacial pain, but, except where they occur subsequent to trauma, their cause remains unknown. This cross-sectional study assessed chewing function (habitual chewing side) and the differences of the chewing side and condylar path and lateral anterior guidance angles in participants with chronic unilateral temporomandibular disorder. This is the preliminary report of a randomized trial that aimed to test the effect of a new occlusal adjustment therapy. METHODS: The masticatory function of 21 randomly selected completely dentate participants with chronic temporomandibular disorders (all but one with unilateral symptoms) was assessed by observing them eat almonds, inspecting the lateral horizontal movement of the jaw, with kinesiography, and by means of interview. The condylar path in the sagittal plane and the lateral anterior guidance angles with respect to the Frankfort horizontal plane in the frontal plane were measured on both sides in each individual. RESULTS: Sixteen of 20 participants with unilateral symptoms chewed on the affected side; the concordance (Fisher's exact test, P = .003) and the concordance-symmetry level (Kappa coefficient κ = 0.689; 95% confidence interval [CI], 0.38 to 0.99; P = .002) were significant. The mean condylar path angle was steeper (53.47(10.88) degrees versus 46.16(7.25) degrees; P = .001), and the mean lateral anterior guidance angle was flatter (41.63(13.35) degrees versus 48.32(9.53) degrees P = .036) on the symptomatic side. DISCUSSION: The results of this study support the use of a new term based on etiology, "habitual chewing side syndrome", instead of the nonspecific symptom-based "temporomandibular joint disorders"; this denomination is characterized in adults by a steeper condylar path, flatter lateral anterior guidance, and habitual chewing on the symptomatic side.


Asunto(s)
Hábitos , Masticación , Trastornos de la Articulación Temporomandibular/fisiopatología , Adolescente , Adulto , Anciano , Femenino , Humanos , Registro de la Relación Maxilomandibular , Masculino , Cóndilo Mandibular/patología , Cóndilo Mandibular/fisiopatología , Persona de Mediana Edad , Dolor/complicaciones , Trastornos de la Articulación Temporomandibular/complicaciones , Trastornos de la Articulación Temporomandibular/etiología , Trastornos de la Articulación Temporomandibular/patología , Adulto Joven
11.
FEMS Microbiol Ecol ; 84(3): 625-39, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23398056

RESUMEN

Redox transition zones play a crucial role in biogeochemical cycles of several major elements. Because microorganisms mediate many reactions of these cycles, they actively participate in establishing geochemical gradients. In turn, the geochemical gradients structure microbial communities. We studied the interrelationship between the bacterial community structure and the geochemical gradient in the Cariaco Basin, the largest truly marine anoxic basin. This study's dataset includes bacterial community composition in 113 water column samples as well as the data for environmental variables (gradients of oxygen, hydrogen sulfide, sulfite, thiosulfate, ammonia, nitrate, nitrite, dissolved manganese and iron, dark CO2 fixation, and bacterial abundance) collected between 1997 and 2006. Several prominent bacterial groups are present throughout the entire water column. These include members of Gamma-, Delta-, and Epsilonproteobacteria, as well as members of the Marine Group A, the candidate divisions OP11 and Car731c. Canonical correspondence analysis indicated that microbial communities segregate along vectors representing oxygenated conditions, nitrite, nitrate and anoxic environments represented by chemoautotrophy, ammonia, sulfite, and hydrogen sulfide.


Asunto(s)
Bacterias/aislamiento & purificación , Agua de Mar/microbiología , Anaerobiosis , Bacterias/clasificación , Bacterias/genética , Bacterias Anaerobias/genética , Bacterias Anaerobias/aislamiento & purificación , Bacterias Anaerobias/fisiología , Dióxido de Carbono/análisis , Ecosistema , Epsilonproteobacteria/genética , Epsilonproteobacteria/aislamiento & purificación , Epsilonproteobacteria/fisiología , Sulfuro de Hidrógeno/análisis , Metagenoma , Nitratos/análisis , Nitritos/análisis , Oxígeno/análisis , Filogenia , Agua de Mar/química , Microbiología del Agua
15.
Am Heart J ; 163(2): 288-94, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22305849

RESUMEN

BACKGROUND: Few data exist on the clinical impact of transcatheter aortic valve implantation (TAVI) in patients with symptomatic aortic stenosis and a high surgical risk. The aim of this study was to determine the survival and the factors predicting mortality after 30 days post-TAVI with the CoreValve prosthesis (Medtronic, Minneapolis, MN). METHODS: From April 2008 to October 2010, the CoreValve prosthesis (Medtronic) was implanted in 133 consecutive high-risk surgical patients with symptomatic severe aortic stenosis. RESULTS: The mean age was 79.5 ± 6.7 years. The logistic European System for Cardiac Operative Risk Evaluation was 21.5% ± 14%. The implantation success rate was 97.7%. In-hospital mortality was 4.5%, and the combined end point of death, vascular complications, myocardial infarction, or stroke had a rate of 9%. Survival at 12 and 24 months was 84.5% and 79%, respectively, after a mean follow-up of 11.3 ± 8 months. The New York Heart Association functional class improved from 3.3 ± 0.5 to 1.18 ± 0.4 and remained stable at 1 year. A high Charlson index (hazard ratio [HR] 1.44, 95% CI 1.09-1.89, P < .01) and a worse Karnofsky score before the procedure (HR 0.95, 95% CI 0.92-0.99, P = .021) were predictors of mortality after 30 days. CONCLUSIONS: Transcatheter aortic valve implantation with the CoreValve prosthesis for patients with aortic stenosis and a high surgical risk is a safe, efficient option resulting in a medium-term clinical improvement. Survival during follow-up depends on the associated comorbidities. Early mortality beyond 30 days is predicted by preoperative comorbidity scores and the functional status of the patient.


Asunto(s)
Estenosis de la Válvula Aórtica/mortalidad , Cateterismo Cardíaco/métodos , Prótesis Valvulares Cardíacas , Anciano , Estenosis de la Válvula Aórtica/cirugía , Femenino , Mortalidad Hospitalaria/tendencias , Humanos , Masculino , Pronóstico , Diseño de Prótesis , Factores de Riesgo , Índice de Severidad de la Enfermedad , España/epidemiología , Tasa de Supervivencia/tendencias , Factores de Tiempo , Resultado del Tratamiento
19.
BMC Biol ; 7: 72, 2009 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-19886985

RESUMEN

BACKGROUND: Recent advances in sequencing strategies make possible unprecedented depth and scale of sampling for molecular detection of microbial diversity. Two major paradigm-shifting discoveries include the detection of bacterial diversity that is one to two orders of magnitude greater than previous estimates, and the discovery of an exciting 'rare biosphere' of molecular signatures ('species') of poorly understood ecological significance. We applied a high-throughput parallel tag sequencing (454 sequencing) protocol adopted for eukaryotes to investigate protistan community complexity in two contrasting anoxic marine ecosystems (Framvaren Fjord, Norway; Cariaco deep-sea basin, Venezuela). Both sampling sites have previously been scrutinized for protistan diversity by traditional clone library construction and Sanger sequencing. By comparing these clone library data with 454 amplicon library data, we assess the efficiency of high-throughput tag sequencing strategies. We here present a novel, highly conservative bioinformatic analysis pipeline for the processing of large tag sequence data sets. RESULTS: The analyses of ca. 250,000 sequence reads revealed that the number of detected Operational Taxonomic Units (OTUs) far exceeded previous richness estimates from the same sites based on clone libraries and Sanger sequencing. More than 90% of this diversity was represented by OTUs with less than 10 sequence tags. We detected a substantial number of taxonomic groups like Apusozoa, Chrysomerophytes, Centroheliozoa, Eustigmatophytes, hyphochytriomycetes, Ichthyosporea, Oikomonads, Phaeothamniophytes, and rhodophytes which remained undetected by previous clone library-based diversity surveys of the sampling sites. The most important innovations in our newly developed bioinformatics pipeline employ (i) BLASTN with query parameters adjusted for highly variable domains and a complete database of public ribosomal RNA (rRNA) gene sequences for taxonomic assignments of tags; (ii) a clustering of tags at k differences (Levenshtein distance) with a newly developed algorithm enabling very fast OTU clustering for large tag sequence data sets; and (iii) a novel parsing procedure to combine the data from individual analyses. CONCLUSION: Our data highlight the magnitude of the under-sampled 'protistan gap' in the eukaryotic tree of life. This study illustrates that our current understanding of the ecological complexity of protist communities, and of the global species richness and genome diversity of protists, is severely limited. Even though 454 pyrosequencing is not a panacea, it allows for more comprehensive insights into the diversity of protistan communities, and combined with appropriate statistical tools, enables improved ecological interpretations of the data and projections of global diversity.


Asunto(s)
Bacterias Anaerobias/fisiología , Biodiversidad , Eucariontes/fisiología , Análisis de Secuencia de ADN/métodos , Animales , Cilióforos/fisiología , Clasificación , ADN Bacteriano/análisis , Agua de Mar , Lugares Marcados de Secuencia
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