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1.
J Invertebr Pathol ; 156: 54-72, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-30017950

RESUMEN

Beauveria bassiana (Bb) strain GHA is a major component of an areawide pest management program for coffee berry borer (CBB) in Hawai'i. Recent studies have aimed to provide comprehensive assessments of the efficacy of the Bb-spray component of these programs for economic analyses; however, evaluations have been complicated by activity of naturally-occurring strains of this pathogen infecting CBB. Investigations were therefore undertaken to characterize these strains, assess their natural epizootic potential, and account for their contribution to CBB population suppression. A number of field sites were encountered with no history of significant use of commercial Bb-based biopesticides and where strain GHA was not detectable. Sampling of these sites was conducted early in the coffee season. Greatest activity of wild-type Bb strains was observed on high-elevation farms (>500 m), where 24-42% of foundress beetles in green coffee berries were infected. In contrast, infection rates did not exceed 4% on farms at low elevations (<300 m). Rates of 23-29% infection, comparable to those on high-elevation farms, were recorded in a stand of feral coffee at 293 m elevation, but the coffee was completely shaded and ventilation restricted by a dense overstory of vegetation. Despite high activity of naturally-occurring Bb at some sites (primarily sites at high elevations with humid, moderate-temperature environments and dense pest populations), these fungi did not prevent CBB from exceeding the economic threshold for commercial spray applications. Nevertheless, the high natural epizootic potential of these fungal strains suggests strong potential for development as microbial biocontrol agents.


Asunto(s)
Beauveria , Micosis/veterinaria , Gorgojos/microbiología , Animales , Hawaii , Control Biológico de Vectores/métodos , Prevalencia
3.
Ann Hum Genet ; 73(2): 171-5, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19207109

RESUMEN

Otosclerosis is one of the most common forms of hearing loss in the European population. We have identified a SNP in the TGFB1 (transforming growth factor beta 1) gene that is associated with susceptibility to otosclerosis. The protective allele of this variant, with isoleucine at position 263 of the protein, is more biologically active than the risk allele, which has a threonine in this position. Because recent studies have shown that not only common, but also rare variants can be involved in complex diseases, we performed DNA sequence analysis of the exons and intron-exon boundaries of TGFB1 in 755 otosclerosis patients and 877 control samples. We found 3 different nonsynonymous variants (E29, A29 and I241) in four otosclerosis patients, but no such changes were found in controls. In silico analysis shows that these variations could influence TGF-beta1 function and activity. Taking into account that most rare missense alleles are thought to have a biological effect, the data suggest that multiple rare amino acid changing variants in TGF-beta1 may contribute to susceptibility to otosclerosis.


Asunto(s)
Predisposición Genética a la Enfermedad , Mutación Missense , Otosclerosis/genética , Factor de Crecimiento Transformador beta1/genética , Estudios de Casos y Controles , Análisis Mutacional de ADN , Europa (Continente) , Femenino , Humanos , Masculino
4.
Gene Ther ; 15(11): 817-22, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18401436

RESUMEN

Although a large percentage of the world population is seropositive for exposure to various strains of adeno-associated virus (AAV), a human parvovirus, AAV has never been identified as an etiologic agent of human disease. Most likely contributing to the pronounced lack of pathogenicity is the fact that AAV is a naturally defective virus that requires a helper virus for productive replication of its genome. Another unusual aspect of wild-type AAV biology is the ability of the virus to establish latent infection by preferential integration of its genome into a specific locus of human chromosome 19. Site-specific integration was a major impetus for the development of recombinant AAV vectors, which typically lack all AAV coding sequences. It was soon realized, however, that expression of at least one species of the virally encoded initiator proteins, Rep78 or Rep68, is necessary for targeted integration of AAV-derived DNA constructs to occur. This article will present a chronological outline of studies characterizing site-specific integration of wild-type AAV sequences and the quasi-random target site selection observed with recombinant AAV vectors.


Asunto(s)
Dependovirus/genética , Terapia Genética/métodos , Vectores Genéticos/administración & dosificación , Genoma Viral , Humanos , Mutagénesis Sitio-Dirigida , Transducción Genética/métodos , Integración Viral , Latencia del Virus
5.
Postgrad Med J ; 83(977): 206-8, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17344578

RESUMEN

PURPOSE: To evaluate the predictive value of N-terminal pro B-type natiuretic peptide (NT-proBNP) reference cut-off values as diagnostic markers for left ventricular systolic dysfunction (LVSD). STUDY DESIGN: A retrospective study assessing the use of NT-proBNP in the diagnostic algorithm for the investigation of patients with suspected signs and symptoms of LVSD presenting to primary care. RESULTS: A generic NT-proBNP cut-off (150 ng/l) value has similar negative and positive predictive valves, specificity and sensitivity compared to age and sex specific cut-off values. CONCLUSION: When using NT-proBNP as a triage tool for screening patients with signs and symptoms suggestive of LVSD, a simple generic cut-off level is as effective as more complex age sex specific cut-off values.


Asunto(s)
Péptido Natriurético Encefálico/metabolismo , Fragmentos de Péptidos/metabolismo , Disfunción Ventricular Izquierda/diagnóstico , Adulto , Anciano , Biomarcadores/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Valores de Referencia , Estudios Retrospectivos , Sensibilidad y Especificidad
6.
Heart ; 91(10): 1330-7, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16162629

RESUMEN

OBJECTIVE: To report one year results of the MERLIN (Middlesbrough early revascularisation to limit infarction) trial, a prospective randomised trial comparing the strategy of coronary angiography and urgent revascularisation with conservative treatment in patients with failed fibrinolysis complicating ST segment elevation myocardial infarction (STEMI). The 30 day results have recently been published. At the planning stage of the trial, it was determined that follow up of trial patients would continue annually to three years to determine whether late benefit occurred. SUBJECTS: 307 patients who received a fibrinolytic for STEMI but failed to reperfuse early according to previously described ECG criteria and did not develop cardiogenic shock. METHODS: Patients were randomly assigned to receive either emergency coronary angiography with a view to proceeding to urgent revascularisation (rescue percutaneous coronary intervention (rPCI) arm) or continued medical treatment (conservative arm). The primary end point was all cause mortality at 30 days. The secondary end points included the composite end point of death, reinfarction, stroke, unplanned revascularisation, or heart failure at 30 days. The same end points were evaluated at one year and these results are presented. RESULTS: All cause mortality at one year was similar in the conservative arm and the rPCI arm (13.0% v 14.4%, p = 0.7, risk difference (RD) -1.4%, 95% confidence interval (CI) -9.3 to 6.4). The incidence of the composite secondary end point of death, reinfarction, stroke, unplanned revascularisation, or heart failure was significantly higher in the conservative arm (57.8% v 43.1%, p = 0.01, RD 14.7%, 95% CI 3.5% to 25.5%). This was driven almost exclusively by a significantly higher incidence of subsequent unplanned revascularisation in the conservative arm (29.9% v 12.4%, p < 0.001, RD 17.5%, 95% CI 8.5% to 26.4%). Reinfarction and clinical heart failure were numerically, but not statistically, more common in the conservative arm (14.3% v 10.5%, p = 0.3, RD 3.8%, 95% CI -3.7 to 11.4, and 31.2% v 26.1%, p = 0.3, RD 5.0%, 95% CI -5.1 to 15.1). There was a strong trend towards fewer strokes in the conservative arm (1.3% v 5.2%, p = 0.06, RD -3.9%, 95% CI -8.9 to 0.06). CONCLUSION: At one year of follow up, there was no survival advantage in the rPCI arm compared with the conservative arm. The incidence of the composite secondary end point was significantly lower in the rPCI arm, but this was driven almost entirely by a highly significant reduction in the incidence of further revascularisation.


Asunto(s)
Infarto del Miocardio/terapia , Revascularización Miocárdica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Angioplastia Coronaria con Balón/métodos , Electrocardiografía , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/etiología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Revascularización Miocárdica/mortalidad , Recurrencia , Resultado del Tratamiento
8.
Laryngoscope ; 111(4 Pt 1): 715-8, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11359145

RESUMEN

Today, genetic testing is an option for individuals who have deafness and hard-of-hearing conditions (D/HOH) and their families for diagnosis and carrier detection. As more and more D/HOH genes are identified, genetic testing will become commonplace. However, genetic testing is different from other tests that physicians commonly order and therefore should be conducted differently. The objective of this study was to determine the best manner in which to conduct genetic testing for individuals who have D/HOH. Numerous studies have shown that pretest and post-test genetic counseling is beneficial for patients and families undergoing genetic testing for a variety of conditions. The need for counseling was emphasized by our recently completed study in which we found that the majority of individuals whose children had genetic testing for D/HOH had a poor understanding of many genetic issues concerning recurrence risks for D/HOH and the meaning of the test results. We think that genetic counseling should be an integral part of genetic testing for individuals who have D/HOH.


Asunto(s)
Sordera/genética , Asesoramiento Genético , Trastornos de la Audición/genética , Adulto , Actitud Frente a la Salud , Niño , Sordera/diagnóstico , Tamización de Portadores Genéticos , Trastornos de la Audición/diagnóstico , Humanos
9.
Semin Neurol ; 20(2): 233-45, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10946744

RESUMEN

Neurologic injures are the leading cause of death and disability in skiing and snowboarding accidents, despite accounting for only a small fraction of injuries overall. Head injuries make up 3 to 15% of all skiing and snowboarding related injuries, spinal injuries account for 1 to 13%, and peripheral nerve injuries constitute less than 1% of reported injuries. Improvements in equipment and technology, especially advances in binding technology, have resulted in decreased injury rates on the slopes overall, but neurologic injury rates have not decreased, and in fact appear to be increasing as a percentage of overall injuries and in absolute numbers. With advances in technology and slope maintenance, skiers and boarders progress to higher skill levels and faster speeds more rapidly than ever before. Great efforts have been focused on reducing extremity injuries in skiers and snowboarders, but until recently very little attention has been given to neurologic injury prevention on the slopes. Hopefully with increased awareness and the growing popularity of ski/snowboard helmets, we will begin to see head injury rates (and maybe even spine injury rates) decrease among skiers and snowboarders.


Asunto(s)
Traumatismos en Atletas/clasificación , Traumatismos en Atletas/etiología , Traumatismos Craneocerebrales/clasificación , Traumatismos Craneocerebrales/etiología , Esquí/lesiones , Traumatismos Vertebrales/clasificación , Traumatismos Vertebrales/etiología , Prevención de Accidentes , Accidentes por Caídas/prevención & control , Accidentes por Caídas/estadística & datos numéricos , Adolescente , Adulto , Factores de Edad , Anciano , Traumatismos en Atletas/epidemiología , Traumatismos en Atletas/patología , Lesiones Encefálicas/epidemiología , Lesiones Encefálicas/etiología , Lesiones Encefálicas/patología , Niño , Preescolar , Traumatismos Craneocerebrales/epidemiología , Traumatismos Craneocerebrales/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso Periférico/epidemiología , Enfermedades del Sistema Nervioso Periférico/etiología , Enfermedades del Sistema Nervioso Periférico/patología , Factores de Riesgo , Factores Sexuales , Esquí/fisiología , Traumatismos Vertebrales/epidemiología , Traumatismos Vertebrales/patología
10.
J Exp Bot ; 51(347): 1107-15, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10948238

RESUMEN

The protective functions that have been ascribed to anthocyanins in leaves can be performed as effectively by a number of other compounds. The possibility that anthocyanins accumulate most abundantly in leaves deficient in other phytoprotective pigments has been tested. Pigment concentrations and their histological distribution were surveyed for a sample of 1000 leaves from a forest population of Quintinia serrata, which displays natural polymorphism in leaf colour. Eight leaf phenotypes were recognized according to their patterns of red coloration. Anthocyanins were observed in almost all combinations of every leaf tissue, but were most commonly located in the vacuoles of photosynthetic cells. Red leaves contained two anthocyanins (Cy-3-glc and Cy-3-gal), epicuticular flavones, epidermal flavonols, hydroxycinnamic acids, chlorophylls, and carotenoids. Green leaves lacked anthocyanins, but had otherwise similar pigment profiles. Foliar anthocyanin levels varied significantly between branches and among trees, but were not correlated to concentrations of other pigments. Anthocyanins were most abundant in older leaves on trees under canopies with south-facing gaps. These data indicate that anthocyanins are associated with photosynthesis, but do not serve an auxiliary phytoprotective role. They may serve to protect shade-adapted chloroplasts from brief exposure to high intensity sunflecks.


Asunto(s)
Antocianinas/química , Fotosíntesis , Árboles/química , Cloroplastos/fisiología , Cromatografía Líquida de Alta Presión , Flavonoides/análisis , Flavonoides/aislamiento & purificación , Hojas de la Planta/anatomía & histología , Hojas de la Planta/química , Hojas de la Planta/fisiología , Árboles/anatomía & histología , Árboles/fisiología
11.
Protein Eng ; 13(6): 413-21, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10877852

RESUMEN

A computational model of the non-nucleoside inhibitor 8-Cl TIBO complexed with HIV-1 reverse transcriptase (RT) was constructed in order to determine the binding free energies. Using Monte Carlo simulations, both free energy perturbation and linear response calculations were carried out for the transformation of wild-type RT to two key mutants, Y181C and L100I. The newer linear response method estimates binding free energies based on changes in electrostatic and van der Waals energies and solvent-accessible surface areas. In addition, the change in stability of the protein between the folded and unfolded states was estimated for each of these mutations, which are known to emerge upon treatment with the inhibitor. Results from the calculations revealed that there is a large hydrophobic contribution to protein stability in the native, folded state. The calculated absolute free energies of binding from both the linear response, and also the more rigorous free energy perturbation method, gave excellent agreement with the experimental differences in activity. The success of the relatively rapid linear response method in predicting experimental activities holds promise for estimating the activity of the inhibitors not only against the wild-type RT, but also against key protein variants whose emergence undermines the efficacy of the drugs.


Asunto(s)
Sustitución de Aminoácidos , Benzodiazepinas/química , Simulación por Computador , Transcriptasa Inversa del VIH/química , Transcriptasa Inversa del VIH/genética , Imidazoles/química , Método de Montecarlo , Mutación , Diseño de Fármacos , Farmacorresistencia Microbiana/fisiología , Estabilidad de Enzimas/genética , VIH/enzimología , Modelos Moleculares , Unión Proteica/fisiología , Pliegue de Proteína , Inhibidores de la Transcriptasa Inversa/química , Relación Estructura-Actividad , Termodinámica
12.
J Virol ; 74(7): 3122-9, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10708427

RESUMEN

The Rep78 protein of adeno-associated virus (AAV) contains amino acid sequence motifs common to rolling-circle replication (RCR) initiator proteins. In this report, we describe RCR initiator-like activities of Rep78. We demonstrate that a maltose-binding protein (MBP)-Rep78 fusion protein can catalyze the cleavage and ligation of single-stranded DNA substrates derived from the AAV origin of replication. Rep-mediated single-stranded DNA cleavage was strictly dependent on the presence of certain divalent cations (e.g., Mn(2+) or Mg(2+)) but did not require the presence of a nucleoside triphosphate cofactor. Electrophoretic mobility shift assays demonstrated that binding of single-stranded DNA by MBP-Rep78 was influenced by the length of the substrate as well as the presence of potential single-stranded cis-acting sequence elements. Site-directed mutagenesis was used to examine the role of specific tyrosine residues within a conserved RCR motif (motif 3) of Rep78. Replacement of Tyr-156 with phenylalanine abolished the ability of MBP-Rep78 to mediate the cleavage and ligation of single-stranded DNA substrates but not the ability to stably bind single-stranded DNA. The cleaving-joining activity of Rep78 is consistent with the mechanism of replicative intermediate dimer resolution proposed for the autonomous parvoviruses and may have implications for targeted integration of recombinant AAV vectors.


Asunto(s)
ADN de Cadena Simple/metabolismo , ADN Viral/metabolismo , Proteínas de Unión al ADN/metabolismo , Dependovirus/genética , Origen de Réplica/genética , Proteínas Virales/metabolismo , Secuencia de Bases , Catálisis , Proteínas de Unión al ADN/genética , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Proteínas Virales/genética
13.
Plant Cell Rep ; 19(12): 1165-1170, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30754851

RESUMEN

In this research, a medium was developed that would stimulate multiple shoot initiation from shoot apex explants of Hibiscus cannabinus L. (kenaf). Adventitious shoot formation on a shoot induction media supplemented with combinations of 2,4-dichlorophenoxyacetic acid (2,4-D) (0, 0.5, 2.3 µmol·l-1) and thidiazuron (N-phenyl-N'-1,2,3-thiadiazol-5-ylurea; TDZ) (0, 1, 5, 20 µmol·l-1) was evaluated. Multiple shoot induction medium with 1 µmol·TDZ l-1 resulted in the highest number of regenerated shoots per explant for all three kenaf cultivars tested (Tainung 1, Tainung 2, and Everglades 71). The 2,4-D did not enhance multiple shoot formation. Additionally, kenaf cultivars 7N and SF459 also produced multiple shoots on the induction medium with 1 µmol·TDZ l-1. Multiple shoot clumps formed after 2 weeks in culture without callus formation. Shoots elongated and rooted within 2 weeks after subculture on a plant growth regulator-free medium. A histological study demonstrated the de novo regeneration of shoots from the shoot apex.

14.
Twin Res ; 3(4): 234-41, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11463144

RESUMEN

Assisted reproductive techniques and fertility enhancing therapies have increased multiple births and, therefore, the risk of prematurity and its developmental consequences. Parent intervention is an effective source of compensation for the cognitive effects of prematurity. We hypothesized that relative to parents of preterm singletons, parents of preterm twins are less able to provide such enhancing care, resulting in a developmental disadvantage for preterm twins. Maternal-infant interactions of premature singletons (n = 22; birth weight = 1668 +/- 350 g, gestational age = 32.3 +/- 2.1 weeks) and premature twins (n = 8; birth weight = 1618 +/- 249 g; gestational age = 32.0 +/- 2.6 weeks) with comparable demographic and medical status were observed at home at 1 and 8 months corrected age using a 30 min checklist of developmentally facilitative behavior. Mental (MDI) and psychomotor (PDI) indices of the Bayley Scales of Infant Development and Caldwell Home Observations for Measurement of the Environment (HOME) inventories were administered (18 months corrected age). Compared with mothers of premature singletons, mothers of premature twins exhibited fewer initiatives (P < 0.001) and responses (P < 0.01) and were less responsive to positive signals (P < 0.01) and crying (P < 0.01). Unprompted by the infant, twin mothers lifted or held (P < 0.05), touched (P < 0.01), patted (P < 0.05) or talked (P < 0.01) less. Singleton MDIs surpassed twins (119.4 +/- 7.7 vs 103.6 +/- 7.7; P < 0.01). Maternal verbal behavior and the acceptance of child factor (HOME), both favoring singletons, correlated with MDI (R-square = 0.46, P < 0.0002). Mothers of premature twins exhibited fewer initiatives and responses toward offspring than did mothers of premature singletons. Maternal behavior was predictive of cognitive development.


Asunto(s)
Desarrollo Infantil , Recien Nacido Prematuro/psicología , Conducta Materna , Relaciones Madre-Hijo , Madres/psicología , Gemelos/psicología , Adulto , Cognición , Comunicación , Señales (Psicología) , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido , Estudios Longitudinales , Masculino , Valor Predictivo de las Pruebas , Análisis de Regresión , Factores de Riesgo , Estrés Psicológico/psicología , Tacto , Conducta Verbal
15.
J Trauma ; 46(6): 1089-95, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10372632

RESUMEN

BACKGROUND: Polymorphonuclear leukocytes have been reported to play an important role in various acute lung injuries. Neutrophil recruitment into tissues is a multistep process involving sequential engagement of adhesion molecules. The objective of this study was to determine the effect of selectin inactivation with Sulfo Lewis C (SO3-3betaGal1-3betaGlcNAc-O(CH2)8-COOMe) on the pulmonary response to lipopolysaccharide (LPS) infusion. METHODS: All animals (n = 11) were pretreated with an intramuscular injection of a priming dose of Escherichia coli LPS (10 microg/kg). Eighteen hours later, animals received an intravenous infusion of LPS (20 microg/kg) over 20 minutes. All animals were resuscitated with a lactated Ringer's solution. Group I (G1; n = 5) received no additional treatment. Group II (G2; n = 6) received a bolus injection of Sulfo Lewis C (10 mg/kg) 10 minutes before LPS insult followed by a continuous infusion (1 mg/kg per hour) for the rest of the study. Animals were observed for 5 hours from initiation of the LPS infusion and killed. Cardiopulmonary variables and blood gases were measured serially. The multiple inert gas elimination technique (MIGET) was used to evaluate the matching of air flow and blood flow in the lung 5 hours after LPS infusion. Histologic evaluation of the parenchymal injury was performed by using light microscopy. The number of polymorphonuclear leukocytes and red blood cells in the alveolar spaces per field at 400x magnification were counted in 10 randomly selected fields. RESULTS: Hypoxemia, indexed as Pao2/FIO2, was exacerbated by the administration of Sulfo Lewis C (G1:437+/-33 vs. G2: 241+/-63 mm Hg at 5 hours, p<0.03). This finding is supported by the multiple inert gas elimination technique analysis, which demonstrated significantly greater blood flow to true shunt in G2 (G1:4.42+/-1.75 vs. G2:23.2+/-5.69, p<0.02). There was no difference between the two groups in red blood cell counts in the alveolar spaces. However, polymorphonuclear leukocyte counts were significantly greater in G2 (G1:1.8+/-0.58 vs. G2:9.9+/-2.34, p<0.01). CONCLUSION: Selectin blockade significantly worsened lung injury induced by LPS infusion, and greater numbers of neutrophils were observed in alveolar spaces in the group treated with Sulfo Lewis C. These findings are supported by the multiple inert gas elimination technique analysis, which demonstrated significantly greater blood flow to the true shunt compartment in treated animals. Further studies are required to determine the role of selectins in sepsis-induced lung injury.


Asunto(s)
Antígenos del Grupo Sanguíneo de Lewis , Lipopolisacáridos/efectos adversos , Pulmón/fisiopatología , Oligosacáridos/farmacología , Selectinas/fisiología , Animales , Recuento de Células Sanguíneas , Femenino , Hemodinámica , Porcinos
16.
Ann Neurol ; 45(6): 805-9, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10360776

RESUMEN

Anti-Yo (type I) autoantibodies reactive with Purkinje cell cytoplasmic antigens of 34 and 62 kd are found in the serum and cerebrospinal fluid of patients with paraneoplastic cerebellar degeneration associated with cancer of the ovary, uterus, adnexa, or breast. Anti-Yo antibody response is rarely associated with other tumors. Here, we present a patient who developed paraneoplastic cerebellar degeneration and anti-Yo antibody response in association with transitional cell carcinoma of the bladder. The presence of anti-Yo antibodies was confirmed by immunofluorescence assay and by Western blot analysis against both Purkinje cell lysates and the CDR62 fusion protein. Yo antigen was demonstrated in sections of the patient's tumor. Antibody titers fell after tumor removal. Transitional cell carcinoma should be considered in patients presenting with subacute cerebellar degeneration and anti-Yo antibody response in whom ovarian, adnexal, uterine, or breast cancer cannot be detected.


Asunto(s)
Carcinoma de Células Transicionales/patología , Enfermedades Cerebelosas/patología , Proteínas de Unión al ADN/análisis , Proteínas de Neoplasias/análisis , Proteínas del Tejido Nervioso , Síndromes Paraneoplásicos/patología , Neoplasias de la Vejiga Urinaria/patología , Autoantígenos , Femenino , Humanos , Técnicas para Inmunoenzimas , Persona de Mediana Edad
18.
J Med Chem ; 41(26): 5272-86, 1998 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-9857095

RESUMEN

Monte Carlo (MC) simulations in combination with a linear response approach were used to estimate the free energies of binding for a series of 12 TIBO nonnucleoside inhibitors of HIV-1 reverse transcriptase. Separate correlations were made for the R6 and S6 absolute conformations of the inhibitors, as well as for the analogous N6-monoprotonated species. Models based upon the neutral unbound inhibitors produced overall better fits to experimental values than did those using the protonated unbound inhibitors, with only slight differences between the neutral R6 and S6 cases. The best results were obtained with a three-parameter linear response equation containing van der Waals (alpha), electrostatic (beta), and solvent accessible surface area (SASA, gamma) terms. The averaged (R6 and S6) rms error was approximately 0.88 kcal/mol for the observed range of 4.06 kcal/mol in inhibitor activities. The averaged values of alpha, beta, and gamma were -0.150, 0.114, and 0. 0286, respectively. Omission of the alpha term gave beta 0.152 and gamma 0.022 with a rms of 0.92. The unweighted van der Waals components were found to be highly attractive but failed to correlate well across the series of inhibitors. Contrastingly, while the electrostatic components are all repulsive, they show a direct correlation with inhibitor activity as measured by DeltaGbinding. The role of gamma is primarily to produce an overall negative binding energy, and it can effectively be replaced with a negative constant. During the MC simulations of the unbound solvated inhibitors, the R6 and S6 absolute conformations do not interconvert due to the formation of a favorable hydrogen bond to solvent. In the complex, however, interconversion of these conformations of the inhibitor is observed during the course of the simulations, a phenomenon which is apparently not observed in the crystalline state of the complex. Hydrogen bonding of the inhibitor to the backbone NH of K101 and the lack of such an interaction with the C=O of K101 or with solvent correlate with enhanced activity, as does the ability to assume a number of different orientations of the inhibitor dimethylallyl moiety with respect to residues Y181 and Y188 while retaining contact with W229. Overall, the use of a combination of MC simulation with a linear response method shows promise as a relatively rapid means of estimating inhibitor activities. This approach should be useful in the preliminary evaluation of potential modifications to known inhibitors to enhance activity.


Asunto(s)
Fármacos Anti-VIH/química , Benzodiazepinas/química , Transcriptasa Inversa del VIH/antagonistas & inhibidores , Imidazoles/química , Inhibidores de la Transcriptasa Inversa/química , Fármacos Anti-VIH/metabolismo , Benzodiazepinas/metabolismo , Sitios de Unión , Transcriptasa Inversa del VIH/metabolismo , Enlace de Hidrógeno , Imidazoles/metabolismo , Modelos Moleculares , Conformación Molecular , Método de Montecarlo , Inhibidores de la Transcriptasa Inversa/metabolismo
19.
J Comput Assist Tomogr ; 22(5): 732-7, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9754108

RESUMEN

PURPOSE: The purpose of this study was to analyze interobserver agreement in the interpretation of unenhanced helical CT (UHCT) for the evaluation of ureteral stone disease and obstruction. METHOD: One hundred three UHCT examinations were independently and retrospectively reviewed by five readers including attending radiologists, a radiology resident, and an attending urologist. Examinations were interpreted as positive, negative, or indeterminate for ureteral stone disease and obstruction. The Cohen kappa test was used to measure interobserver agreement. The accuracy of the readers was also assessed. RESULTS: The kappa value ranged from 0.67 to 0.71 among the three attending radiologists and from 0.65 to 0.67 among the radiology attending physicians and radiology resident. Although the urologist tended to agree less well with the other readers (kappa range: 0.33-0.46), there was no statistically significant difference (p < 0.05) in the accuracy among all five readers. The percentage of cases interpreted as indeterminate ranged from 8 to 25% and almost invariably involved difficulty distinguishing phleboliths from minimally obstructing distal ureteral calculi. The percentage of UHCT scans correctly interpreted as positive and correctly interpreted as negative ranged from 73% (n = 27) to 86% (n = 32) and 63% (n = 22) to 86% (n = 30), respectively. CONCLUSION: Interobserver agreement was very good among the radiology attending physicians and resident and moderate with the urologist. The examination is an accurate technique in the evaluation of ureteral stone disease, although limitations exist, particularly in the diagnosis of minimally obstructing distal ureteral calculi.


Asunto(s)
Tomografía Computarizada por Rayos X/métodos , Cálculos Ureterales/diagnóstico por imagen , Dolor Abdominal/diagnóstico por imagen , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Uréter/diagnóstico por imagen
20.
Mol Cell Biol ; 18(10): 5921-9, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9742109

RESUMEN

Adeno-associated virus encodes four nonstructural proteins, which are known as Rep78, Rep68, Rep52, and Rep40. Expression of these nonstructural proteins affects cell growth and gene expression through processes that have not yet been characterized. Using a yeast two-hybrid screen, we have demonstrated that a stable interaction occurs between the viral proteins Rep78 and Rep52 and the putative protein kinase PrKX, which is encoded on the X chromosome. The stability and specificity of the Rep-PrKX interaction were confirmed by coimmunoprecipitation of complexes assembled in vitro and in vivo. Overexpressed PrKX, which was purified from cos cells, was shown to phosphorylate a synthetic protein kinase A (PKA) substrate. However, this activity was dramatically inhibited by stoichiometric amounts of Rep52 and weakly inhibited with Rep68, which lacks the carboxy-terminal sequence contained in Rep52. Similarly, a stable interaction was observed with Rep78, which also contains the carboxy-terminal sequence of Rep52. A stable interaction and inhibition were also observed between Rep52 and the catalytic subunit of PKA. By using surface plasmon resonance and kinetic studies, Kis of approximately 300 and 167 nM were calculated for Rep52 with PKA and with PrKX, respectively. Thus, Rep52 but not Rep68 can significantly inhibit the trans- and autophosphorylation activities of these kinases. The biological effects of Rep78-specific inhibition of PKA-responsive genes are illustrated by the reduction of steady-state levels of cyclic AMP-responsive-element-binding protein and cyclin A protein.


Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas de Unión al ADN/metabolismo , Dependovirus/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Virales/metabolismo , Secuencia de Aminoácidos , Animales , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas de Unión al ADN/genética , Células HeLa , Humanos , Datos de Secuencia Molecular , Fosforilación , Proteínas Quinasas/genética , Conejos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Análisis Espectral , Proteínas Virales/genética
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