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1.
eNeuro ; 7(4)2020.
Artículo en Inglés | MEDLINE | ID: mdl-32586843

RESUMEN

Rhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACCs) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelations of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms' structure as opposed to mere auditory phenomena. The autocorrelation approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.


Asunto(s)
Música , Estimulación Acústica , Percepción Auditiva , Electrocorticografía , Humanos , Imaginación , Periodicidad
3.
Med Vet Entomol ; 28(1): 85-93, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23647177

RESUMEN

Mosquito and West Nile virus (WNV) surveillance was conducted on a national wildlife refuge in northeast Montana in 2005 and 2006, during which outbreaks of WNV in a colony of American white pelicans (Pelecanus erythrorhynchos Gmelin) (Pelecaniformes: Pelecanidae) resulted in juvenile mortality rates of ∼ 31%. Both years, floodwater species Ochlerotatus dorsalis (Meigen) (Diptera: Culicidae), Aedes vexans (Meigen) (Diptera: Culicidae) and Ochlerotatus flavescens (Muller) (Diptera: Culicidae) comprised 78% of the total collection and heightened host-seeking activity was observed from mid-June to mid-July. Culex tarsalis Coquillett (Diptera: Culicidae) was most active from mid-July to mid-August and comprised 18% of the collection in 2005 and 20% in 2006. However, fewer than 10% of the Cx. tarsalis females collected in 2006 were obtained adjacent to the pelicans' nesting grounds. Minimum infection rates per 1000 Cx. tarsalis tested for WNV were 1.36 in 2005 and 1.41 in 2006. All pools in which WNV was detected in 2006 were composed of females collected 10 km from the nesting grounds. Substantial juvenile pelican mortality in 2006 despite reductions in the population of the primary vector and in mosquito infection rates near the colony suggests that the methods used to detect the introduction of WNV were too coarse and that amplification of the virus within the colony may reflect causes other than mosquito infection.


Asunto(s)
Enfermedades de las Aves/epidemiología , Culicidae/fisiología , Culicidae/virología , Insectos Vectores/fisiología , Insectos Vectores/virología , Fiebre del Nilo Occidental/epidemiología , Virus del Nilo Occidental/fisiología , Animales , Enfermedades de las Aves/mortalidad , Enfermedades de las Aves/virología , Conducta Alimentaria , Montana/epidemiología , Dinámica Poblacional , Estaciones del Año , Fiebre del Nilo Occidental/mortalidad , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/aislamiento & purificación
4.
J Am Mosq Control Assoc ; 29(2): 146-53, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23923329

RESUMEN

A rise in the incidence of mosquito-transmitted Cache Valley virus (CVV) in lambs in 2011 prompted a study to evaluate on-animal pyrethroid insecticides to reduce mosquito attacks on sheep. Using enclosure traps for 1 night per wk for 6 wk, we compared engorgement rates of mosquitoes given the opportunity to feed on untreated sheep and sheep treated with 1 Python insecticide ear tag (containing 10% zeta-cypermethrin and 20% piperonyl butoxide) per animal or 2 synergized permethrin body spray treatments (containing 2.5% permethrin and 2.5% piperonyl butoxide). During the 6-wk study, 18,920 mosquitoes were collected in the animal-baited enclosure traps. Thirteen species were identified from these collections with the floodwater species Aedes increpitus and Ae. idahoensis making up 68% of the total. Potential CVV vector species, making up 25% of the samples, included Ae. vexans, Ae. dorsalis, Culex tarsalis, and Culiseta inornata. Traps baited with untreated sheep collected 9,701 mosquitoes with 65% of these engorged. Traps baited with sheep treated with Python ear tags or permethrin spray collected 4,034 and 4,555, respectively, with engorgement rates of 23% and 35%. Blood feeding on ear-tagged sheep was significantly reduced by as much as 90% compared to the untreated sheep, and protection lasted 4 wk or longer. Permethrin spray treatments were most effective within 24 h after application and provided better protection against Ae. dorsalis than the Python tag. Effectiveness of the permethrin spray diminished 1 wk after the 2nd application was made. The effect of these treatments appeared to be repellency because negligible mosquito mortality was observed at the time of collection. Further evaluation of these insecticides under conditions of natural exposure to a mosquito-borne pathogen is warranted.


Asunto(s)
Culicidae , Repelentes de Insectos , Control de Mosquitos , Piretrinas , Administración Cutánea , Animales , Culicidae/fisiología , Conducta Alimentaria , Montana , Ovinos
5.
Vet Pathol ; 49(2): 362-71, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22291071

RESUMEN

Migrating bats have increased mortality near moving turbine blades at wind farms. The authors evaluated competing hypotheses of barotrauma and traumatic injury to determine the cause. They first examined the utility of lungs from salvaged bat carcasses for histopathologic diagnosis of barotrauma and studied laboratory mice as a model system. Postmortem time, environmental temperature, and freezing of carcasses all affected the development of vascular congestion, hemorrhage, and edema. These common tissue artifacts mimicked the diagnostic criteria of pulmonary barotrauma; therefore, lung tissues from salvaged bats should not be used for barotrauma diagnosis. The authors next compared wind farm (WF) bats to building collision (BC) bats collected near downtown Chicago buildings. WF bats had an increased incidence in fracture cases and specific bone fractures and had more external lacerations than BC bats. WF bats had additional features of traumatic injury, including diaphragmatic hernia, subcutaneous hemorrhage, and bone marrow emboli. In summary, 73% (190 of 262) of WF bats had lesions consistent with traumatic injury. The authors then examined for ruptured tympana, a sensitive marker of barotrauma in humans. BC bats had only 1 case (2%, 1 of 42), but this was attributed to concurrent cranial fractures, whereas WF bats had a 20% (16 of 81) incidence. When cases with concurrent traumatic injury were excluded, this yielded a small fraction (6%, 5 of 81) of WF bats with lesions possibly consistent with barotrauma etiology. Forensic pathology examination of the data strongly suggests that traumatic injury is the major cause of bat mortality at wind farms and, at best, barotrauma is a minor etiology.


Asunto(s)
Quirópteros/lesiones , Centrales Eléctricas , Viento , Heridas y Lesiones/veterinaria , Animales , Barotrauma/mortalidad , Barotrauma/patología , Barotrauma/veterinaria , Chicago , Oído Medio/lesiones , Femenino , Medicina Legal/métodos , Fracturas Óseas/mortalidad , Fracturas Óseas/patología , Fracturas Óseas/veterinaria , Congelación , Hernia Diafragmática/patología , Hernia Diafragmática/veterinaria , Incidencia , Pulmón/patología , Lesión Pulmonar/mortalidad , Lesión Pulmonar/patología , Lesión Pulmonar/veterinaria , Ratones , Edema Pulmonar/patología , Edema Pulmonar/veterinaria , Temperatura , Factores de Tiempo , Heridas y Lesiones/mortalidad , Heridas y Lesiones/patología
6.
Ann R Coll Surg Engl ; 93(7): 542-7, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22004638

RESUMEN

Earlier diagnosis is a key aim in achieving improved outcomes for patients with cancer. Bone and soft tissue sarcomas represent approximately 1% of all malignant tumours. Delays in diagnosis are frequent both because of their rarity and because the clinical features are easily confused with other conditions. In 2000 advice on earlier diagnosis was widely publicised. This study investigates how two factors that may act as a proxy for delay in diagnosis have varied over a 25-year period and whether there is evidence of improvement. Data on symptom duration and tumour size were collected prospectively on all new sarcoma patients referred to an orthopaedic oncology unit over 25 years. Data were available for 2,568 patients with primary bone sarcomas and 2,366 with soft tissue sarcomas. The mean sarcoma size at diagnosis was 10.7 cm and 9.9 cm respectively. The size of bone sarcomas had not changed over time but there had been a slight decrease in the size of soft tissue sarcomas (10.3 cm before 2000 vs 9.6 cm after 2000, p=0.03). The duration of symptoms reported by patients varied widely with a median of 16 weeks for bone sarcomas and 26 weeks for soft tissue sarcomas. The median duration of symptoms for bone sarcomas had actually increased since 2000 (16 weeks before vs 20 weeks after 2000, p<0.01). It remained unchanged for soft tissue sarcomas. These data show there is huge room for improvement in diagnosing bone and soft tissue sarcomas. New strategies are needed urgently.


Asunto(s)
Neoplasias Óseas/patología , Sarcoma/patología , Neoplasias de los Tejidos Blandos/patología , Adulto , Factores de Edad , Diagnóstico Tardío , Detección Precoz del Cáncer , Femenino , Humanos , Masculino , Factores Sexuales , Carga Tumoral
7.
Mol Hum Reprod ; 17(12): 721-6, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21831882

RESUMEN

Intact ribosomal RNAs (rRNAs) comprise the majority of somatic transcripts, yet appear conspicuously absent in spermatozoa, perhaps reflecting cytoplasmic expulsion during spermatogenesis. To discern their fate, total RNA retained in mature spermatozoa from three fertile donors was characterized by Next Generation Sequencing. In all samples, >75% of total sequence reads aligned to rRNAs. The distribution of reads along the length of these transcripts exhibited a high degree of non-uniformity that was reiterated between donors. The coverage of sequencing reads was inversely correlated with guanine-cytosine (GC)-richness such that sequences greater than ∼70% GC were virtually absent in all sperm RNA samples. To confirm the loss of sequence, the relative abundance of specific regions of the 28S transcripts in sperm was established by 7-Deaza-2'-deoxy-guanosine-5'-triphosphate RT-PCR. The inability to amplify specific regions of the 28S sequence from sperm despite the abundant representation of this transcript in the sequencing libraries demonstrates that approximately three-quarters of RNA retained in the mature male gamete are products of rRNA fragmentation. Hence, cleavage (not expulsion of the RNA component of the translational machinery) is responsible for preventing spurious translation following spermiogenesis. These results highlight the potential importance of those transcripts, including many mRNAs, which evade fragmentation and remain intact when sperm are delivered at fertilization. Sequencing data are deposited in GEO as: GSE29160.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Biosíntesis de Proteínas/fisiología , División del ARN/fisiología , ARN Ribosómico 28S/metabolismo , ARN Ribosómico/metabolismo , Espermatogénesis/genética , Espermatozoides/metabolismo , Composición de Base , Fertilidad/genética , Fertilización/genética , Humanos , Masculino , ARN Ribosómico/genética , ARN Ribosómico 28S/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Testículo/metabolismo
8.
Sarcoma ; 2008: 378574, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18317511

RESUMEN

Introduction and aims. It is well established that soft tissue sarcomas (STSs) are more effectively treated in a specialist centre. However, delays in time taken for a patient to be referred to a specialist centre may lead to a poorer prognosis. This study aims to identify the length of these delays and where they occur. Patients and methods. Patients with a proven STS were included. They were recruited from both outpatient clinics and from the surgical ward of the Royal Orthopaedic Hospital (Birmingham, UK). A structured interview was used to take a detailed history of the patients' treatment pathway, before arriving at the specialist centre. Dates given were validated using the case notes. Results. The median time for the patient to present to a specialist centre from the onset of symptoms was 40.4 weeks. The median delay until presentation to a medical professional (patient delay) was 1.3 weeks. Median delay in referral to a specialist centre (service delay) was 25.0 weeks. Discussion. Medical professionals rather than patients contribute the greatest source of delay in patients reaching a specialist centre for treatment of STS. Adherence to previously published guidelines could decrease this delay for diagnosis of possible sarcoma. Steps should be taken to refer patients directly to a diagnostic centre if they have symptoms or signs suggestive of STS.

9.
J Agric Food Chem ; 49(5): 2497-502, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11368626

RESUMEN

Sodium orthophenylphenate (SOPP) has been used extensively for >40 years to control postharvest diseases of citrus fruits. Studies of the metabolism of [(14)C]SOPP have identified orthophenylphenol (OPP) as the major metabolite with phenylhydroquinone (PHQ) as a minor metabolite. The whole-fruit tolerance in the United States for OPP is 10 ppm. This study was conducted to quantify terminal OPP and PHQ residues in whole Navel oranges, grapefruit, and lemons following SOPP applications at maximum application rates and following commercial application and fruit storage practices. OPP and PHQ residues also were determined in products processed from treated Navel oranges. OPP residues in lemons, Navel oranges, and grapefruit treated with SOPP using foamer wash and shipping wax applications remained below the 10 ppm tolerance, and PHQ residues were all < or =0.439 ppm. PHQ residues in whole fruit increased with time in commercial storage. OPP residues in all Navel orange matrices except oil remained relatively stable with time in commercial storage; residues in oil declined substantially while in storage.


Asunto(s)
Compuestos de Bifenilo/análisis , Citrus/química , Fungicidas Industriales/análisis , Hidroquinonas/análisis , Manipulación de Alimentos , Residuos de Plaguicidas/análisis , Factores de Tiempo
10.
J Cardiovasc Pharmacol ; 36(5 Suppl 1): S22-5, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11078325

RESUMEN

Phosphoramidon has been shown to inhibit endothelin-converting enzyme-1 (ECE-1) in a remarkably pH-dependent manner (Ahn et al. Arch Biochem Biophys 1998;359:258-68). In order to determine whether this dramatic pH-dependence is a general phenomenon of ECE-1, two structurally unrelated ECE-1 inhibitors, PD 069185 and CGS 31447, were tested for ECE-1 inhibition at various pH values. Our data indicate that the potencies of these ECE-1 inhibitors are also highly affected by pH. ECE-1 is known to have a very sharp activity optimum at neutral pH which is in marked contrast to the acidic pH optimum for ECE-2. However, our results show that the pH optimum for ECE-1 activity is highly substrate-dependent. ECE-1 hydrolyzes the small peptide hormones bradykinin and substance P with acidic pH optima of 5.6-5.8, which sharply contrasts the neutral pH optimum with big ET-1 as substrate. These data suggest that the substrate preference for ECE-1 is highly affected by pH and that this pH-dependence for substrate preference might be one way of controlling the specificity of the enzyme in vivo.


Asunto(s)
Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Organofosfonatos/farmacología , Inhibidores de Proteasas/farmacología , Quinazolinas/farmacología , Tetrazoles/farmacología , Bradiquinina/metabolismo , Enzimas Convertidoras de Endotelina , Humanos , Concentración de Iones de Hidrógeno , Metaloendopeptidasas , Sustancia P/metabolismo , Especificidad por Sustrato
11.
Anal Biochem ; 286(1): 112-8, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11038281

RESUMEN

Endothelin-converting enzyme-1 (ECE-1) is a membrane-bound zinc-metallopeptidase that is related to neprilysin in amino acid sequence. A major in vivo function of ECE-1 is the proteolytic conversion of big endothelin-1 to endothelin-1, one of the most potent vasconstricting peptides known. Although ECE-1 was once thought to be specific for the processing of endothelin precursors, it is now known that the enzyme hydrolyzes a number of peptide hormones. We have incorporated knowledge gained from recent studies of ECE-1 substrate specificity to aid the design of internally-quenched fluorescent substrates derived from bradykinin. The best of these substrates, (7-methoxycoumarin-4-yl)acetyl-Arg-Pro-Pro-Gly-Phe-Ser-Ala-Phe-Lys(2, 4-dinitrophenyl), is hydrolyzed by ECE-1 with a k(cat)/K(m) value of 1.9 x 10(7) M(-1) s(-1), making it the most sensitive substrate yet described for ECE-1. The substrate is suitable for the rapid, continuous assay of the enzyme using a microplate format in a fluorescence plate reader, thereby simplifying both the purification of ECE-1 and the characterization of its inhibitors. It is demonstrated that (7-methoxycoumarin-4-yl)acetyl-Arg-Pro-Pro-Gly-Phe-Ser-Ala-Phe-Lys(2, 4-dinitrophenyl) is also a substrate for neprilysin, but is hydrolyzed 10-fold more efficiently by ECE-1, making this substrate selective for ECE-1. Furthermore, this synthetic peptide is a poor substrate for the matrix metalloproteinases.


Asunto(s)
Ácido Aspártico Endopeptidasas/metabolismo , Química Clínica/métodos , Colorantes Fluorescentes/síntesis química , Animales , Bradiquinina/análogos & derivados , Células CHO , Cromatografía Líquida de Alta Presión , Cricetinae , Enzimas Convertidoras de Endotelina , Humanos , Concentración de Iones de Hidrógeno , Hidrólisis , Concentración 50 Inhibidora , Cinética , Metaloendopeptidasas , Neprilisina/química , Neprilisina/metabolismo , Péptidos/síntesis química , Péptidos/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Especificidad por Sustrato , Transfección
12.
J Econ Entomol ; 93(2): 293-9, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10826175

RESUMEN

The toxicity of imidaloprid to the migratory grasshopper, Melanoplus sanguinipes (F.), was measured in bioassays, greenhouse trials, and field trials. An LD50 of 53 and 86 ppm for the oral/topical applications of imidacloprid confirmed a low toxicity for this chemical when compared with carbofuran as a standard. However, 100% debilitation was observed at concentrations of > or = 1 ppm. Grasshoppers exhibited leg flexing, abdominal quivering, and tremors before becoming motionless and appearing dead. Knockdown was temporary with a high percentage of recovery within 1 h. Efficacy and feeding damage were determined from artificial infestations of M. sanguinipes at the 2nd, 4th, and early tillering growth stages of winter and spring wheat treated with foliar and seed treatments of imidacloprid. All rates of imidacloprid tested resulted in < 45% mortality to 4th instar and adult M. sanguinipes in the greenhouse and field. Although efficacy was low, high rates of debilitation in bioassays suggest that improved control may be gained by combining imidacloprid with insect pathogens or additional chemicals.


Asunto(s)
Saltamontes , Imidazoles , Control de Insectos , Insecticidas , Animales , Bioensayo , Control de Insectos/métodos , Neonicotinoides , Nitrocompuestos
13.
J Trauma Stress ; 13(1): 23-39, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10761172

RESUMEN

One hundred twenty-five commercial fishers in Cordova, Alaska, completed a mailed survey regarding current mental health functioning 6 years after the Exxon Valdez oil spill. Economic and social impacts of the oil spill and coping and psychological functioning (modified Coping Strategies Scales, Symptom Checklist 90-R) were measured. Multiple regression was used to test the utility of the Conservation of Resources stress model for explaining observed psychological symptoms. Current symptoms of depression, anxiety, and Posttraumatic Stress Disorder were associated with conditions resource loss and avoidant coping strategies. The Conservation of Resources model provided a framework for explaining psychological impacts of the oil spill. Future research is needed to identify factors related to recovery.


Asunto(s)
Adaptación Psicológica , Desastres , Explotaciones Pesqueras , Aceites Combustibles , Motivación , Trastornos por Estrés Postraumático/diagnóstico , Contaminación Química del Agua , Adulto , Alaska , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Inventario de Personalidad , Trastornos por Estrés Postraumático/psicología
14.
Arch Biochem Biophys ; 373(2): 385-93, 2000 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-10620363

RESUMEN

Endothelin converting enzyme-1 (ECE-1) is a type II integral membrane protein and a zinc metalloendopeptidase. ECE-1 generates endothelin-1 (ET-1), the most potent vasoconstrictor yet discovered, by specific proteolytic processing of a precursor peptide, big ET-1. An insect cell expression system, which generates up to 4.3 mg of a secreted, soluble form of ECE-1 (solECE-1) per liter culture medium, has been established and solECE-1 was purified to homogeneity using five chromatographic steps. SolECE-1 expressed in insect cells could be suitable for X-ray structure determination as it is much less glycosylated than solECE-1 from mammalian cells. SolECE-1 from both sources, nonetheless, has comparable enzymatic properties. Despite apparent structural similarities, ECE-1 cleaves big ET-1 exclusively between Trp(21) and Val(22), in contrast to neprilysin, which cleaves big ET-1 at various sites. However, when linear big ET-1, in which the formation of disulfide bonds has been prevented by alkylation of the four cysteines, was used as substrate, it was cleaved by solECE-1 at multiple sites. This result indicates that secondary/tertiary structure of big ET-1 induced by disulfide bonds is essential for the specific cleavage of the Trp(21)-Val(22) bond by ECE-1. A continuous, fluorescent ECE-1 assay has been developed using a novel substrate, 2-aminobenzoyl-Arg-Pro-Pro-Gly-Phe-Ser-Pro-(p-nitro-Phe(8))-Arg. This simple and rapid assay can greatly facilitate discovery of novel ECE inhibitors useful as pharmaceutical agents.


Asunto(s)
Ácido Aspártico Endopeptidasas/química , Disulfuros/química , Endotelinas/química , Precursores de Proteínas/química , Secuencia de Aminoácidos , Animales , Ácido Aspártico Endopeptidasas/genética , Baculoviridae/genética , Bradiquinina/química , Cromatografía Líquida de Alta Presión , Endotelina-1 , Enzimas Convertidoras de Endotelina , Inhibidores Enzimáticos/farmacología , Glicopéptidos/farmacología , Glicosilación , Humanos , Cinética , Metaloendopeptidasas , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Quinazolinas/farmacología , Proteínas Recombinantes/química , Espectrometría de Fluorescencia , Spodoptera/genética
15.
J Econ Entomol ; 93(1): 38-42, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14658509

RESUMEN

The toxicity of imidacloprid to the cereal leaf beetle, Oulema melanopus (L.), was measured under laboratory and field conditions. Insect mortality and plant damage were determined from artificial and natural infestations of O. melanopus applied to various growth stages of barley. All rates of imidacloprid formulated and applied as a seed treatment caused >90% mortality to cereal leaf beetle larvae when barley was infested with eggs at the 4-leaf stage, but were ineffective when barley was infested with eggs at the early tillering or flag-leaf stages of barley. This window of susceptibility influenced results obtained in field trials where peak larval emergence did not occur until the early tillering stage of barley. The resulting mortality in plants from treated seeds never exceeded 40% in the field. Foliar imidacloprid, however, caused >90% mortality in the field, and may be another option in the management of the cereal leaf beetle.


Asunto(s)
Escarabajos , Hordeum , Imidazoles , Insecticidas , Animales , Hordeum/crecimiento & desarrollo , Larva , Neonicotinoides , Nitrocompuestos
16.
Mol Phylogenet Evol ; 11(3): 415-25, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10196082

RESUMEN

Fragments of 12S and 16S mitochondrial DNA genes were sequenced for 14 acanthuroid taxa (representing all six families) and seven outgroup taxa. The combined data set contained 1399 bp after removal of all ambiguously aligned positions. Examination of site saturation indicated that loop regions of both genes are saturated for transitions, which led to a weighted parsimony analysis of the data set. The resulting tree topology generally agreed with previous morphological hypotheses, most notably placing the Luvaridae within the Acanthuroidei, but it also differed in several areas. The putative sister group of Acanthuroidei, Drepane, was recovered within the suborder, and the sister group of the family Acanthuridae, Zanclus, was likewise recovered within the family. Morphological characters were included to produce a combined data set of 1585 characters for 14 acanthuroid taxa and a single outgroup taxon. An analysis of the same 15 taxa was performed with only the DNA data for comparison. The total-evidence analysis supports the monophyly of the Acanthuridae. A parametric bootstrap suggests the possibility that the paraphyly of Acanthuridae indicated by the molecular analyses is the result of long-branch attraction. The disagreement between molecular and morphological data on the relationships of the basal acanthuroids and its putative sister taxon is unresolved.


Asunto(s)
Perciformes/genética , Filogenia , Animales , ADN Mitocondrial/química , ADN Mitocondrial/genética , Evolución Molecular , Datos de Secuencia Molecular , Perciformes/anatomía & histología , Perciformes/clasificación , ARN Ribosómico/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
17.
J Biol Chem ; 274(7): 4053-8, 1999 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-9933597

RESUMEN

Endothelins are peptide hormones with a potent vasoconstrictor activity that are also known to function as intercellular signaling molecules. The final step in the biosynthesis of endothelins is the proteolytic processing of precursor peptides by endothelin-converting enzymes (ECEs). ECE-1 is a zinc metalloendopeptidase related in amino acid sequence to neprilysin, a mammalian cell-surface peptidase involved in the metabolism of numerous biologically active peptides. Despite apparent structural similarities, ECE-1 and neprilysin have been considered to differ significantly in substrate specificity. In this study we have examined the activity of recombinant ECE-1 against a collection of biologically active peptides. ECE-1, unlike neprilysin, was found to have minimal activity against substrates smaller than hexapeptides, such as Leu-enkephalin. Larger peptides such as neurotensin, substance P, bradykinin, and the oxidized insulin B chain were hydrolyzed by ECE-1 as efficiently as big endothelin-1, a known in vivo substrate. Identification of the products of hydrolysis of six peptides indicates that ECE-1 has a substrate specificity similar to that of neprilysin, preferring to cleave substrates at the amino side of hydrophobic residues. The data indicate that ECE-1 possesses a surprisingly broad substrate specificity and is potentially involved in the metabolism of biologically active peptides distinct from the endothelins.


Asunto(s)
Ácido Aspártico Endopeptidasas/metabolismo , Metaloendopeptidasas/metabolismo , Neprilisina/metabolismo , Péptidos/metabolismo , Secuencia de Aminoácidos , Animales , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Sitios de Unión , Células CHO , Línea Celular , Cricetinae , Enzimas Convertidoras de Endotelina , Humanos , Hidrólisis , Insulina/metabolismo , Cinética , Espectrometría de Masas , Datos de Secuencia Molecular , Inhibidores de Proteasas/farmacología , Quinazolinas/farmacología , Especificidad por Sustrato
18.
J Speech Lang Hear Res ; 41(6): 1335-40, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9859888

RESUMEN

HINT list equivalency was examined using 24 listeners between 60 and 70 years old who had sensorineural hearing impairment. A Greco-Latin square design was used to ensure that each list was presented an equal number of times per condition. Four conditions were tested: (1) speech in quiet, (2) speech in 65 dBA noise with noise at 0 degrees azimuth, (3) speech in 65 dBA noise with noise at 90 degrees azimuth, and (4) speech in 65 dBA noise with noise at 270 degrees azimuth. Speech materials were always presented at 0 degrees azimuth. Overall mean scores ranged from 29.9 dBA for the quiet condition to 63.4 dBA for the noise at 0 degrees azimuth condition. A significant difference was found between Lists 13 and 16 only. This was attributed to audibility differences among the listeners. Therefore, the 25 HINT lists should be considered equivalent for older populations with similar hearing impairment. The HINT lists can be used for relative measures, such as comparison of aided versus unaided sentence SRTs or comparison of 2 different hearing aids.


Asunto(s)
Pérdida Auditiva Sensorineural/diagnóstico , Percepción del Habla , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad
19.
Clin Exp Immunol ; 113(3): 360-6, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9737663

RESUMEN

By analysis with a panel of CD21 MoAbs it is shown that a large part of the soluble CD21 in human blood plasma is of the long isoform (CD21L), as judged by comparison with antigen produced by mouse L cells transfected with CD21L-cDNA and reactivity with the restricted CD21 MoAb R4/23. This is compatible with the hypothesis that soluble CD21 in the blood is mainly derived from follicular dendritic cells (FDC). Cells from a human keratinocyte cell line transfected with cDNA from the Burkitt lymphoma cell line Raji also produced soluble CD21L (sCD21L), whereas the short form of sCD21 (sCD21S) was the major component of sCD21 produced by the B lymphoblastoid cell line LICR-LON-HMy and the T cell line Jurkat. Confocal studies of FDC isolated from human tonsil revealed that CD21 was present in the cytoplasm. On gel filtration sCD21 from untreated serum has an apparent size considerably greater than the 130kD found by SDS-PAGE analysis. This may be partly accounted for by the non-globular shape of the molecule, but may also indicate, as reported by others, that in its native state sCD21 is complexed with other proteins. However, no evidence of complexing with sCD23 or C3d could be found.


Asunto(s)
Receptores de Complemento 3d/sangre , Animales , Células Dendríticas/química , Humanos , Ratones , Receptores de Complemento 3d/análisis , Células Tumorales Cultivadas
20.
FEBS Lett ; 425(3): 391-5, 1998 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-9563500

RESUMEN

Apoptosis specific proteins (ASP) are expressed in the cytoplasm of cultured mammalian cells of various lineages following induction of apoptosis. The cDNA encoding ASP has been cloned from a human expression library and has significant homology to the Saccharomyces cerevisiae APG5 gene which is essential for yeast autophagy. The ASP gene, known as hAPG5, can be transcribed to give mRNAs of 3.3 kbp, 2.5 kbp and 1.8 kbp which are present at comparable levels in viable and apoptotic cells, demonstrating that protein expression must be regulated at the translational level. These data indicate a possible relationship between apoptosis and autophagy and suggest evolutionary conservation in mammalian apoptosis of a degradative process present in yeast.


Asunto(s)
Apoptosis/fisiología , Autofagia/fisiología , Proteínas del Citoesqueleto/química , Proteínas Fúngicas/química , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/química , Animales , Proteína 5 Relacionada con la Autofagia , Secuencia de Bases , Células COS , Clonación Molecular , Inhibidores de Cisteína Proteinasa/farmacología , Proteínas Fúngicas/fisiología , Regulación de la Expresión Génica/genética , Humanos , Datos de Secuencia Molecular , ARN Mensajero/metabolismo , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Transfección/genética , Ubiquitina-Proteína Ligasas
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