Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Más filtros











Intervalo de año de publicación
1.
J Pediatr Urol ; 15(1): 12-17, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30606637

RESUMEN

INTRODUCTION: Voiding cystourethrogram (VCUG) with fluoroscopy remains the gold standard for detection and evaluation of vesicoureteral reflux (VUR) among children. However, the ionizing radiation exposure remains a concern for this diagnostic modality. Recent studies have proposed using contrast-enhanced ultrasound as an alternative option for VUR screening and follow-up in children. The aim of the study was to review the literature of comparative studies that assessed the diagnostic accuracy of contrast-enhanced ultrasound compared with VCUG. METHODOLOGY: A systematic literature search was performed on electronic medical literature databases in July 2017. Literature identification, screening, and assessment of eligibility were performed by five reviewers with a pediatric radiologist. Literature was summarized for the study population, contrast used, and ultrasound mode as well as the timing of comparative reference study being performed. The studies were clustered according to the kind of contrast used. Reported diagnostic accuracy was extracted from individual studies and summarized across the included studies using descriptive statistics of median and interquartile range (IQR). RESULT: A total of 45 comparative studies were identified as eligible for the summary of the literature. Two generations of ultrasound contrast were identified in the available studies (first generation, Levovist and second generation, SonoVue). For the ultrasound studies using the first-generation contrast, the median sensitivity, regardless of the ultrasound mode, was 90.25 (IQR 83.25-97), and the median specificity was 93 (IQR 91.3-95.25). Among studies using the second-generation contrast, the median sensitivity was 86.26 (IQR 81.13-97), and the median specificity was 90.99 (IQR 84-98). No serious adverse events were reported in any of the studies. CONCLUSION: Overall, this review highlights the application of contrast-enhanced ultrasound for its advantage of no exposure to ionizing radiation and diagnostic accuracy relatively comparable to VCUG in the evaluation of VUR. In addition to the functional evaluation of the VUR, it also provides an anatomic evaluation of the kidneys and bladder with ultrasound imaging. However, one should also note that this alternate procedure is highly operator dependent where diagnostic accuracy is excellent when the expertise is available.


Asunto(s)
Medios de Contraste , Reflujo Vesicoureteral/diagnóstico por imagen , Niño , Humanos , Ultrasonografía/métodos
2.
Comput Human Behav ; 35: 364-375, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25717216

RESUMEN

The American Academy of Pediatrics recommends no screen time for children under the age of 2 and limited screen time for all children. However, no such guidelines have been proposed for preteens and teenagers. Further, research shows that children, preteens, and teenagers are using massive amounts of media and those with more screen time have been shown to have increased obesity, reduced physical activity, and decreased health. This study examined the impact of technology on four areas of ill-being-psychological issues, behavior problems, attention problems and physical health-among children (aged 4-8), preteens (9-12), and teenagers (13-18) by having 1030 parents complete an online, anonymous survey about their own and their child's behaviors. Measures included daily technology use, daily food consumption, daily exercise, and health. Hypothesis 1, which posited that unhealthy eating would predict impaired ill-being, was partially supported, particularly for children and preteens. Hypothesis 2, which posited that reduced physical activity would predict diminished health levels, was partially supported for preteens and supported for teenagers. Hypothesis 3, that increased daily technology use would predict ill-being after factoring out eating habits and physical activity, was supported. For children and preteens, total media consumption predicted illbeing while for preteens specific technology uses, including video gaming and electronic communication, predicted ill-being. For teenagers, nearly every type of technological activity predicted poor health. Practical implications were discussed in terms of setting limits and boundaries on technology use and encouraging healthy eating and physical activity at home and at school.

3.
Bioorg Med Chem ; 5(9): 1873-82, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9354244

RESUMEN

A series of racemic balanol analogues with modification of the benzamido moiety of balanol have been synthesized and evaluated for their inhibitory activities against human protein kinase C isozymes (PKC-alpha, -beta I, -beta II, -gamma, -delta, -epsilon, and -eta). The structural modification includes replacement of the 4-hydroxyphenyl group with variously substituted phenyl rings, substitution of the amide linkage with a sulfonamide or an ester, and replacement of the 4-hydroxyphenyl substructure with a hydroxyl substituted indole or a hydroxybenzyl group. in general, these analogues were found to be less potent than balanol, but a number of analogues were identified with improved isozyme selectivity. The structure-activity relationship studies of these analogues also indicated that (1) the optimal general PKC inhibition requires a free 4-hydroxyl group in the benzamido portion of the molecule, (2) the amide linkage of the benzamido moiety is important for PKC inhibition, and (3) the conformation associated with the benzamido moiety seems to have a profound effect on PKC inhibition. The requirement of a free 4-hydroxyl group in conjunction with an appropriate conformation of the benzamido moiety for optimal PKC inhibition suggests that the 4-hydroxyphenyl group may be involved in a specific inhibitor-enzyme interaction important for PKC inhibition.


Asunto(s)
Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Isoenzimas/antagonistas & inhibidores , Proteína Quinasa C/antagonistas & inhibidores , Animales , Baculoviridae/genética , Inhibidores Enzimáticos/química , Humanos , Isoenzimas/metabolismo , Espectroscopía de Resonancia Magnética , Estructura Molecular , Proteína Quinasa C/metabolismo , Proteínas Recombinantes/antagonistas & inhibidores , Espectrofotometría Infrarroja , Spodoptera , Relación Estructura-Actividad
4.
J Med Chem ; 40(2): 226-35, 1997 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-9003521

RESUMEN

Balanol is a potent protein kinase C (PKC) inhibitor that is structurally composed of a benzophenone diacid, a 4-hydroxybenzamide, and a perhydroazepine ring. A number of balanol analogs in which the perhydroazepine moiety is replaced have been synthesized and their biological activities evaluated against both PKC and cAMP-dependent kinase (PKA). The results suggested that the activity and the isozyme/kinase selectivity of these compounds are largely related to the conformation about this nonaromatic structural element of the molecules.


Asunto(s)
Azepinas/síntesis química , Azepinas/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Hidroxibenzoatos/síntesis química , Hidroxibenzoatos/farmacología , Isoenzimas/antagonistas & inhibidores , Proteína Quinasa C/antagonistas & inhibidores , Conformación Molecular , Relación Estructura-Actividad
5.
J Med Chem ; 39(26): 5215-27, 1996 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-8978850

RESUMEN

A series of balanol analogs in which the perhydroazepine ring and the p-hydroxybenzamide moiety were combined into an acyclic linked unit have been prepared and evaluated for their inhibitory properties against the serine/threonine kinase PKC. Several low-micromolar to low-nanomolar inhibitors of the alpha, beta I, beta II, gamma, delta, epsilon and eta PKC isozymes were prepared. In general, these acyclic balanol analogs were found to be highly selective for PKC over the serine/threonine kinase PKA. The type and number of atoms linking the benzophenone ester to the p-hydroxyphenyl group necessary for optimal PKC inhibition were investigated. The most potent compounds contained a three-carbon linker in which the carboxamide moiety of balanol had been replaced by a methylene group. The effect of placing substituents on the three-carbon chain was also investigated. The preferred compounds contained either a 2-benzenesulfonamido (6b) or a 1-methyl (21b) substituent. The preferred compounds 6b and 21b were tested against a panel of serine/threonine kinases and found to be highly selective for PKC. The more active enantiomer of 6b, (S)-12b, was 3-10-fold more active than the R-enantiomer against the PKC isozymes. The effect of making the analogs more rigid by making the three-carbon chain part of a five-membered ring, but with retention of the methylene replacement for the carboxamide moiety, led to potent PKC inhibitors including anti-substituted pyrrolidine analog 35b and the most potent PKC inhibitor in the series, anti-substituted cyclopentane analog 29b. The anti cyclopentane analog 29b, was a low-micromolar inhibitor of the PMA-induced superoxide burst in neutrophils, and its carboxylic ester was a high-nanomolar inhibitor of neutrophils. Finally esterification of 21b, (S)-12b, and 35b turned these potent PKC inhibitors into low-micromolar inhibitors of neutrophils.


Asunto(s)
Azepinas/química , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Inhibidores Enzimáticos/farmacología , Hidroxibenzoatos/química , Proteína Quinasa C/antagonistas & inhibidores , Animales , Azepinas/farmacología , Inhibidores Enzimáticos/química , Humanos , Hidroxibenzoatos/farmacología , Espectroscopía de Resonancia Magnética , Ratas , Proteínas Recombinantes/antagonistas & inhibidores , Especificidad por Sustrato
6.
In. Simposio Internacional sobre Prevención de Desastres Sísmicos = International Symposium on Earthquake Disaster Prevention. Memoria. México, D. F, México. Centro Nacional de Prevención de Desastres (CENAPRED);Japón. Agencia de Cooperación Internacional (JICA);N.U. Centro para el Desarrollo Regional (UNCRD), 1992. p.325-9, ilus.
Monografía en En | Desastres | ID: des-3257

RESUMEN

It is shown a digital instrument system employed in the study of structure and soil behavior by the strong ground motion if the expecting frecuency range for the response of structures and soil is lower than 50 Hz. The system output data is a digital recording of acceleration, velocity and displacement that allows to use any available dynamic structural program for analyzing the signals. Also, it permits to check the quality of the data in the collection sites, a few minutes after it has been obtained, making easily the correction of any system malfunction. It has easy and low cost maintenance (AU)


Asunto(s)
Terremotos , Geología , Ingeniería , Procesamiento de Señales Asistido por Computador , Suelo
7.
Temas Poblac ; 1(4): 33-7, 1991 Dec.
Artículo en Español | MEDLINE | ID: mdl-12317225

RESUMEN

PIP: Some reflections are presented on the impact of Mexico's macroeconomic policy on population dynamics and urban development in the immediate future as the opening and liberalization of the economic increasingly influence market forces. Although the actions envisaged in the macroeconomic policy are not yet consolidated, it is possible to foresee some of their consequences for the city and for population movement. It can be predicted that the macroeconomic policy will lead to greater economic growth and consolidation of the urban population because of positive expectations for stability and growth, and the resultant environment of confidence in the immediate future. A resurgence of private investment in goods and services directed primarily to private consumption will inevitable create demand for public investment in infrastructure and improved services. Demand for consumer durables in likely to rise, as is demand for housing. New residential zones are likely to appear and grow, changing the territorial configuration of urban areas. The urban administration should make some effort to control the growth.^ieng


Asunto(s)
Economía , Política Pública , Población Urbana , Urbanización , Américas , Demografía , Países en Desarrollo , Geografía , América Latina , México , América del Norte , Población
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA