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1.
Philos Trans A Math Phys Eng Sci ; 382(2273): 20230197, 2024 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-38736334

RESUMEN

The origin of micrometeorites (MMs) from asteroids and comets is well-established, but the relative contribution from these two classes remains poorly resolved. Likewise, determining the precise origin of individual MMs is an open challenge. Here, cosmic-ray exposure ages are used to resolve the spatial origins of 12 MMs collected from urban areas and Antarctica. Their 26Al and 10Be concentration, produced during cosmic-ray irradiation in space, were measured by accelerator mass spectrometry. These data are compared to results from a model simulating the transport and irradiation of the MM precursors in space. This model, for the first time, considers a variety of orbits, precursor particle sizes, compositions and densities and incorporates non-isotropic solar and galactic cosmic-ray flux profiles, depth-dependent production rates, as well as spherical evaporation during atmospheric entry. While the origin for six MMs remains ambiguous, two MMs show a preferential tendency towards an origin in the Inner Solar System (Near Earth Objects to the Asteroid Belt) and four towards an origin in the Outer Solar System (Jupiter Family Comets to the Kuiper Belt). These findings challenge the notion that dust originating from the Outer Solar System is unlikely to survive long-term transport and delivery to the terrestrial planets. This article is part of the theme issue 'Dust in the Solar System and beyond'.

2.
Radiography (Lond) ; 27(3): 877-882, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33676836

RESUMEN

INTRODUCTION: This study aimed to evaluate the effects of a newly developed Advanced Edge Enhancement software (AEE) (Canon Europe, Amsterdam, NL) on image quality (IQ) of Digital Radiography (DR) hand images focusing on rheumatoid arthritis (RA). METHODS AND MATERIALS: Fifty posterior-anterior hand images with or suspected for RA were collected. For each of the 50 images, six copies were made with each their AEE algorithm settings. A total of 330 images (30 images iterated) were evaluated using relative Visual Grading Analysis (VGA) by three observers and combined into a VGA Score (VGAS). Second, 50 images of a technical Contrast Detail Radiography Phantom (CDRAD) was produced with three different AEE software settings, each at level 1,5 and without the AEE software yielding 350 CDRAD images. All images was analysed by the CDRAD Analyser and included for an objective analysis of the AEE software. RESULTS: The VGA study showed a significant difference in image quality between a standard image and images with AEE software applied. The average VGA score of the AEE software was better than the standard images (interval between 0.2 and 0.9). The AEE algorithms at level 5 scored significantly lower for noise but significantly higher for spatial resolution, sharpness and contrast in the VGA. The CDRAD images showed that all AEE algorithms had a statistically significant improvement for level 1 and deterioration for level 5 compared to the standard image. CONCLUSION: Overall the AEE algorithm: small structure level 1 showed an improvement of all IQ criteria in the VGA and a better technical IQ. IMPLICATIONS FOR PRACTICE: The AEE software ought to be considered as a useful addition to the current software, possibly enabling visualisation of structures currently visible.


Asunto(s)
Artritis Reumatoide , Intensificación de Imagen Radiográfica , Artritis Reumatoide/diagnóstico por imagen , Humanos , Fantasmas de Imagen , Radiografía , Programas Informáticos
3.
Artículo en Inglés | MEDLINE | ID: mdl-33610169

RESUMEN

BACKGROUND: Chronic tic disorders are neurodevelopmental disorders that can be treated with Habit Reversal Training (HRT) and Exposure Response Prevention (ERP). Intermediate and long-term effects have been examined after individual treatment with HRT, whereas evaluation of long-term outcome after an initial treatment with ERP, or a combination of HRT and ERP is lacking. The present study examines the long-term effect after a combined treatment with HRT and ERP delivered in an individual or a group setting METHODS: Fifty-nine children and adolescents diagnosed with a chronic tic disorder were randomised to manualised treatment combining HRT and ERP as individual or group training. Forty-seven were re-examined 1 year after acute outcome. Outcome measures included Total Tic Severity score (TTS) measured by the Yale Global Tic Severity Scale (YGTSS) and Beliefs About Tics Scale (BATS) RESULTS: In a mixed model, it was shown that the initial improvement with both individual and group treatment was maintained throughout the follow-up period. There were no significant differences between the two methods of treatment delivery. Of all participants completing the 12 months evaluation, 74.4% were considered responders. There was a significant positive association between the reduction of TTS and the reduction in BATS. In a latent class post-treatment trajectory analysis, two classes were identified, where high baseline severity increased the likelihood of being in the lesser responder class. Similar, but only as a trend, having ADHD, planning difficulties or hypersensitivity increased the risk of a lesser response. CONCLUSIONS: The present study compares the efficacy in individualised and group treatment of providing manualised therapy for child and adolescent tic disorders using two behavioural methods (combined HRT and ERP) both of which have been shown to have acute benefits but only one of which has been validated for longer term effectiveness. In the present study, both individualised and group treatments showed benefit throughout a 1-year follow-up period with several potential confounds affecting outcomes, while the relative benefits of either HRT and ERP were not addressed. Trial registration NCT04594044, 1-10-72-216-15, registered 19th October 2020, retrospectively registered, https://register.clinicaltrials.gov/prs/app/template/Home.vm?uid=U0005BW2&ts=9&sid=S000ABEY&cx=-wlx7vb The study is approved by the National Ethical Committee (1-10-72-216-15) and the Danish Data Protection Agency (1-16-02-490-15), registered 12 October 2015.

4.
BMC Psychiatry ; 20(1): 511, 2020 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-33081741

RESUMEN

BACKGROUND: Obsessive compulsive disorder (OCD) is a distressing psychiatric disorder. Traumas may trigger or aggravate OCD symptoms. COVID-19 pandemic has coursed a global crisis and has been associated with onset of psychiatric disorders in adults. Little is known about children/adolescents with OCD. The present study aimed to examine how children/adolescents with OCD react towards COVID-19 crisis. METHODS: A questionnaire was distributed to two separate groups of children/adolescents. One group was a clinical group newly diagnosed at a specialized OCD clinic. All the children/adolescents had a current close contact to a therapist or doctor. The other group was a survey group identified through the Danish OCD Association. Most of these children/adolescents were diagnosed years ago, and their primary treatment was completed. For the clinical group, data from patient files was available. RESULTS: In both groups, but most pronounced in the survey group, participants experienced a worsening of their OCD, anxiety, and depressive symptoms. The aggravation of OCD correlated with the worsening of anxiety, depressive symptoms, and the extent of avoidance behavior. For both groups, OCD aggressive symptoms predicted a significant worsening. Poor baseline insight showed a trend to predict a symptom worsening. The worsening was most pronounced in children with early age of onset and a family history of attention deficit hyperactivity disorder. CONCLUSIONS: To our knowledge, this is one of the first studies examining the effect of COVID-19 in children/adolescents with OCD. The effect was examined in two separate populations strengthening the findings. The study points towards an influence of the OCD phenotype, baseline insight suggesting a continued vulnerability, and a family history of psychiatric disorders. TRIAL REGISTRATION: The study is approved by the Danish Data Protection Agency (1-16-02-147-20) registered 1st of April 2020. Oral and written information was given to parents and patients and written consent from patients over 15 years and parents were received.


Asunto(s)
Infecciones por Coronavirus , Encuestas Epidemiológicas , Trastorno Obsesivo Compulsivo/psicología , Pandemias , Neumonía Viral , Adolescente , COVID-19 , Niño , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/psicología , Dinamarca , Humanos , Neumonía Viral/epidemiología , Neumonía Viral/psicología
5.
BJPsych Open ; 5(5): e74, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31409430

RESUMEN

BACKGROUND: Chronic tic disorders may have a major impact on a child's function. A significant effect has been shown for combined habit reversal training (HRT) and exposure response prevention (ERP) treatment delivered in an individual and group setting. AIMS: The present study examines predictors and moderators of treatment outcome after an acute therapeutic intervention. METHOD: Fifty-nine children and adolescents were randomised to manualised treatment combining HRT and ERP as individual or group training. Age, gender, baseline tic severity, Premonitory Urge for Tics Scale (PUTS) scores, Beliefs about Tic Scale (BATS) scores, hypersensitivity and comorbid psychiatric symptoms were analysed as predictors of outcome. The same characteristics were examined as moderators for individual versus group treatment. Outcome measures included the change in total tic severity (TTS) score and functional impairment score (as measured by the Yale Global Tic Severity Scale (YGTSS)). RESULTS: Internalising symptoms predicted a lesser decrease in functional impairment. The occurrence of obsessive-compulsive symptoms predicted a larger decrease in TTS. Baseline hypersensitivity and high scores on depressive symptoms favoured individual treatment. High baseline PUTS scores favoured group therapy. CONCLUSIONS: This is the first study examining factors predicting and moderating perceived functional impairment following a therapeutic intervention. The study adds to the knowledge on predictors and moderators of TTS. Furthermore, this is the first study examining the effect of the BATS score. The study points towards factors that may influence treatment outcome and that require consideration when choosing supplemental treatment. This applies to comorbid anxiety and depressive symptoms, and to the child's belief about their tics and premonitory urge. DECLARATION OF INTEREST: None.

6.
Eur Child Adolesc Psychiatry ; 26(3): 281-291, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27388606

RESUMEN

The underlying structure of obsessive-compulsive disorder (OCD) remains to be confirmed in child and adolescent populations. In this paper we report the first factor analytic study of individual OCD items from Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). OCD symptoms were assessed using the CY-BOCS symptom checklist in a sample of 854 patients with OCD (7-18 years of age) recruited from clinics in five countries. Pooled data were subjected to exploratory and confirmatory factor analysis (CFA) to identify the optimal factor structure. Various models were tested for age and gender subgroups. Also, the invariance of the solution across age and gender was tested and associations with demographic and clinical factors were explored. A three-factor model provided the best-fit solution. It consisted of the following factors: (1) harm/sexual, (2) symmetry/hoarding, (3) contamination/cleaning. The factor structure was invariant for age and gender across subgroups. Factor one was significantly correlated with anxiety, and factor two with depression and anxiety. Factor three was negatively correlated with tic disorder and attention-deficit/hyperactivity disorder (ADHD). Females had higher scores on factor two than males. The OCD symptom structure in children and adolescents is consistent across age and gender and similar to results from recent child and adolescents although hoarding may not be a separate factor. Our three-factor structure is almost identical to that seen in early studies on adults. Common mental disorders had specific patterns of associations with the different factors.


Asunto(s)
Trastornos de Ansiedad/psicología , Ansiedad/psicología , Trastorno Obsesivo Compulsivo/diagnóstico , Determinación de la Personalidad/estadística & datos numéricos , Conducta Sexual/psicología , Adolescente , Ansiedad/epidemiología , Trastornos de Ansiedad/epidemiología , Niño , Comorbilidad , Comparación Transcultural , Análisis Factorial , Femenino , Acaparamiento/epidemiología , Acaparamiento/psicología , Humanos , Masculino , Trastorno Obsesivo Compulsivo/epidemiología , Trastorno Obsesivo Compulsivo/psicología , Escalas de Valoración Psiquiátrica , Conducta Sexual/etnología , Adulto Joven
8.
Neuroscience ; 297: 11-21, 2015 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-25813705

RESUMEN

Nicotine has been shown to attenuate experimental autoimmune encephalomyelitis (EAE) through inhibiting inflammation in microglial populations during the disease course. In this study, we investigated whether nicotine modified the regenerative process in EAE by examining nestin-expressing neural stem cells (NSCs) in the spinal cord, which is the primary area of demyelination and inflammation in EAE. Our results show that the endogenous neurogenic responses in the spinal cord after EAE are limited and delayed: while nestin expression is increased, the proliferation of ependymal cells is inhibited compared to healthy animals. Nicotine application significantly reduced nestin expression and partially allowed for the proliferation of ependymal cells. We found that reduction of ependymal cell proliferation correlated with inflammation in the same area, which was relieved by the administration of nicotine. Further, increased numbers of oligodendrocytes (OLs) were observed after nicotine treatment. These findings give a new insight into the mechanism of how nicotine functions to attenuate EAE.


Asunto(s)
Encefalomielitis Autoinmune Experimental/complicaciones , Degeneración Nerviosa/tratamiento farmacológico , Degeneración Nerviosa/etiología , Neurogénesis/efectos de los fármacos , Nicotina/uso terapéutico , Agonistas Nicotínicos/uso terapéutico , Animales , Antígenos/metabolismo , Proteínas Relacionadas con la Autofagia , Proteínas de Dominio Doblecortina , Encefalomielitis Autoinmune Experimental/inducido químicamente , Proteína Ácida Fibrilar de la Glía/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/etiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Antígeno Ki-67/metabolismo , Antígenos Comunes de Leucocito/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteínas Asociadas a Microtúbulos/metabolismo , Glicoproteína Mielina-Oligodendrócito/toxicidad , Degeneración Nerviosa/patología , Nestina/metabolismo , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/metabolismo , Neuropéptidos/metabolismo , Fragmentos de Péptidos/toxicidad , Proteoglicanos/metabolismo , Médula Espinal/patología , Factores de Tiempo
9.
Phys Rev Lett ; 90(6): 060403, 2003 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-12633280

RESUMEN

We describe the results of an experiment to test for spacetime anisotropy terms that might exist from Lorentz violations. The apparatus consists of a pair of cylindrical superconducting cavity-stabilized oscillators operating in the TM010 mode with one axis east-west and the other vertical. Spatial anisotropy is detected by monitoring the beat frequency at the sidereal rate and its first harmonic. We see no anisotropy to a part in 10(13). This puts a comparable bound on four linear combinations of parameters in the general standard model extension, and a weaker bound of < 4 x 10(-9) on three others.

10.
Nahrung ; 46(3): 167-73, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12108215

RESUMEN

Three highly reproducible food models have been developed to evaluate rheological and functional properties of starches. The food models are dutch vla, dressing, and white sauce, and they vary in pH, serving temperature, oil content, and content of other functional ingredients than starch (milk proteins, whole egg, carrageenan). The viscous properties were calculated in a controlled stress rheometer, and the power law index, n, and the consistency index, K, was calculated. The viscoelastic properties at small deformations were measured by oscillating viscometry. Also a spreadability analysis was performed. The rheological data for the three food models were analysed by use of a principal component analysis (PCA), which enabled an evaluation of the functionality of the models and visualisation of the correlation to the concentration of starch. The rheological parameters all varied significantly with starch concentration in dutch vla. In dressing and white sauce most of the rheological parameters depended on the starch concentration. In addition, it was found that results from the empirical rheological method (USDA consistometer) correlate well with fundamental rheological parameters. Syneresis was measured for a period of time up to 15 days. The degree of syneresis of dressing was highly dependent on starch concentration, while the syneresis of the white sauce was dependent on time but not on starch concentration. The dutch vla showed no syneresis at all.


Asunto(s)
Productos Lácteos/análisis , Almidón/química , Concentración de Iones de Hidrógeno , Modelos Químicos , Reología , Solanum tuberosum/química , Temperatura , Viscosidad
11.
J Agric Food Chem ; 49(12): 5771-7, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11743762

RESUMEN

Production in a batch reactor with a solvent-free system of structured triacylglycerols containing short-chain fatty acids by Lipozyme RM IM-catalyzed acidolysis between rapeseed oil and caproic acid was optimized using response surface methodology (RSM). Reaction time (t(r)), substrate ratio (S(r)), enzyme load (E(l), based on substrate), water content (W(c), based on enzyme), and reaction temperature (T(e)), the five most important parameters for the reaction, were chosen for the optimization. The range of each parameter was selected as follows: t(r) = 5-17 h; E(l) = 6-14 wt %; T(e) = 45-65 degrees C; S(r) = 2-6 mol/mol; and W(c) = 2-12 wt %. The biocatalyst was Lipozyme RM IM, in which Rhizomucor miehei lipase is immobilized on a resin. The incorporation of caproic acid into rapeseed oil was the main monitoring response. In addition, the contents of mono-incorporated structured triacylglycerols and di-incorporated structured triacylglycerols were also evaluated. The optimal reaction conditions for the incorporation of caproic acid and the content of di-incorporated structured triacylglycerols were as follows: t(r) = 17 h; S(r) = 5; E(l) = 14 wt %; W(c) = 10 wt %; T(e) = 65 degrees C. At these conditions, products with 55 mol % incorporation of caproic acid and 55 mol % di-incorporated structured triacylglycerols were obtained.


Asunto(s)
Caproatos/metabolismo , Lipasa/metabolismo , Triglicéridos/biosíntesis , Brassica , Catálisis , Ácidos Grasos Monoinsaturados , Cinética , Modelos Teóricos , Aceites de Plantas/metabolismo , Aceite de Brassica napus , Rhizomucor/enzimología , Especificidad por Sustrato
12.
J Neurol Neurosurg Psychiatry ; 71(3): 329-33, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11511705

RESUMEN

OBJECTIVES: Adhesion molecules are involved in the pathogenesis of cerebral ischaemia and may play a part in the pathophysiology of delayed ischaemic neurological deficit (DIND) after aneurysmal subarachnoid haemorrhage. It was hypothesised that after aneurysmal subarachnoid haemorrhage, adhesion molecules may play a part in the pathophysiology of DIND as reflected by significantly altered serum concentrations in patients with and without DIND. METHODS: In a prospective study, mean serum concentrations of ICAM-1, VCAM-1, PECAM, and E, P, and L-selectin were compared between patients without (n=23) and with (n=13) DIND in patients with World Federation of Neurological Surgeons (WFNS) grades 1 or 2 subarachnoid haemorrhage. Serum was sampled from patients within 2 days of haemorrhage and on alternate days until discharge. Concentrations of adhesion molecules were measured by standard procedures using commercially available enzyme linked immunoabsorbent assays. RESULTS: There were non-significant differences in serum concentrations of ICAM-1 (290.8 ng/ml v 238.4 ng/ml, p=0.0525), VCAM-1 (553.2 ng/ml v 425.8 ng/ml, p=0.053), and PECAM (22.0 ng/ml v 21.0 ng/ml, p=0.56) between patients without and with DIND respectively. The E-selectin concentration between the two patient groups (44.0 ng/ml v 37.4 ng/ml, p=0.33) was similar. The P-selectin concentration, however, was significantly higher in patients with DIND compared with those patients without DIND (149.5 ng/ml v 112.9 ng/ml, p=0.039). By contrast, serum L-selectin concentrations were significantly lower in patients with DIND (633.8 ng/ml v 897.9 ng/ml, p=0.013). CONCLUSIONS: Of all the adhesion molecules examined in this study, P and L-selectin are involved in the pathophysiology of DIND after aneurysmal subarachnoid haemorrhage.


Asunto(s)
Isquemia Encefálica/sangre , Isquemia Encefálica/etiología , Selectina E/sangre , Molécula 1 de Adhesión Intercelular/sangre , Aneurisma Intracraneal/complicaciones , Selectina L/sangre , Selectina-P/sangre , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/sangre , Hemorragia Subaracnoidea/complicaciones , Molécula 1 de Adhesión Celular Vascular/sangre , Adulto , Anciano , Isquemia Encefálica/inmunología , Isquemia Encefálica/fisiopatología , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Aneurisma Intracraneal/clasificación , Aneurisma Intracraneal/diagnóstico , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Punción Espinal , Hemorragia Subaracnoidea/clasificación , Hemorragia Subaracnoidea/diagnóstico , Tomografía Computarizada por Rayos X
13.
J Agric Food Chem ; 49(8): 3644-50, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11513641

RESUMEN

Several alternative strategies were examined for improving conventional juice fining procedures for cherry juice clarification and fining in laboratory-scale experiments: Centrifugation of freshly pressed juice from 1000g to 35,000g induced decreased turbidity according to a steep, negative power function. Individual and interactive effects on turbidity and haze formation in precentrifuged and uncentrifuged cherry juice of treatments with pectinase, acid protease, bromelain, gallic acid, and gelatin-silica sol were investigated in a factorial experimental design with 32 different parameter combinations. Gelatin-silica sol consistently had the best effect on juice clarity. Centrifugation of cherry juice (10,000g for 15 min) prior to clarification treatment significantly improved juice clarity and diminished the rate of haze formation during cold storage of juice. Both treatment of precentrifuged cherry juice with Novozym 89L protease and co-addition of pectinase and gallic acid improved cherry juice clarity and diminished haze levels. None of the alternative treatments produced the unwieldy colloids notorious to gelatin-silica sol treatment. The data suggest that several alternative clarification strategies deserve further consideration in large-scale cherry juice processing. Precentrifugation of juice before clarification and fining is immediately recommended.


Asunto(s)
Enzimas/farmacología , Manipulación de Alimentos/métodos , Frutas , Bebidas , Centrifugación
14.
Pediatr. (Asunción) ; 28(1): 19-24, jul. 2001. graf
Artículo en Inglés, Español | LILACS, BDNPAR | ID: lil-294507

RESUMEN

La fiebre es un motivo de consulta frecuente en pediatría. La escala de observacional de YALE (YOS) sirve para evaluar la gravedad de un paciente enfermo por medio de la valoración clínica. La escala observacional de YALE (YOS) evalúa seis puntos claves que son: calidad del llanto, reacción ante estímulos, estado de alerta, color de la piel, estado de hidratación, respuesta social del niño. Las seis variables de la escala observacional de YALE (YOS) son cuantificadas con cifras como 1,3 y 5 y una puntuación mayor denota un grado más alto de deterioro clínico. Si la puntuaciación es: igual o menor a 10 hay solo un 3 porcientos de infección bacteriana grave, si es entre 10 y 15 hay un 26 porcientos de posibilidades de infección grave y si es igual o mayor a 16 hay un riesgos de 92 porcientos de infección bacteriana grave. Objetivos: Utilización de la escala observacional de YALE en pacientes pediátricos de 3 a 24 meses que consultan al servicios de Pediatría del Hospital de clínicas. Población y métodos: pacientes lactantes febriles entre 3 a 24 meses que consultan en la urgencia de pediatría. Diseño prospectivo y observacional de corte trasversal. Resultados: Se reclutaron para el estudio un total de 75 pacientes. Edad: entre 3 a 6 meses 26 pacientes (35 porcientos), >6 meses a 12 meses 29 pac. (39 porcientos), >12 a 24 meses 20 pac. (27 porcientos). Sexo: masculino 46 pac. (31 porcientos), femeninos 29 pac. (39 porcientos). Estado nutricional: bien nutridos 27 pac. (36 porcientos), desnutridos 3 pac. (44 porcientos), riesgo de desnutrición 16 pac. (20 porcientos). Tratamiento previo: Sí 58 pacientes (77 porcientos), no 17 pacientes (23 porcientos). De los que recibieron tratamiento previo: antipiréticos 57 pacientes (76 porcientos), antibióticos 1 pacientes (11 porcientos). Diagnósticos asociados: infecciones aereas superioes 48 pac. (60 porcientos), gastroenteritis aguda 20 pac. (26.67 porcientos). Aplicación del puntaje de la escala de YOS. aparentemente sanos 41 pac. (55 porcientos) de los cuales se internaron 2 pac. (5 porcientos); personas enfermas 16 (21 porcientos), seriamente enfermos 18 (24 porcientos). Conclusión: la escala observacional de YALE (YOS) nos permite distinguir entre paciente sanos, aquellos que están enfermos y los muy enfermos, así como tener una buena guía para el tratamiento en urgencias


Asunto(s)
Fiebre , Lactante , Signos y Síntomas
15.
Eur Biophys J ; 30(1): 69-74, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11372535

RESUMEN

When lipophilic compounds like diethyl phthalate (DEP) were added to water, two sets of resonances appeared in the 1H NMR spectrum, whereas when added in concentrations above approximately 3.5 mM to erythrocytes in a high haematocrit suspension, only one set of resonances was observed at the low-frequency position. The appearance of one set of resonances at lower frequency was found to be common to a series of lipophilic compounds in erythrocytes. The appearance of the NMR spectra is ascribed to the existence of an emulsion, meaning two different phases of a compound: a "droplet" (resonances to lower frequency) and aqueous dissolved phase (resonances to higher frequency). The absence of the resonances from the dissolved phase in erythrocyte solution is ascribed to exchange broadening. The absolute chemical shift of the compound in its "droplet" phase was also measured using a cylindrical/spherical microcell. This arrangement mimicked the geometry of the dissolved versus the phase-separated species and thus obviated the effect of a difference in magnetic susceptibility between the "droplet" solute and its aqueous solution. Factors influencing the formation of emulsion phases such as erythrocytes, haemoglobin and smaller proteins were investigated; they are found to be effective in the order given.


Asunto(s)
Eritrocitos/fisiología , Agua , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Hidroxitolueno Butilado , Emulsiones , Hemoglobinas/química , Hemoglobinas/metabolismo , Humanos , Hidrógeno , Resonancia Magnética Nuclear Biomolecular , Ácidos Ftálicos , Solubilidad
16.
Phys Rev Lett ; 86(9): 1904-7, 2001 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-11290278

RESUMEN

As a model system for two-dimensional interface dynamics, we study the wetting front of a lipid membrane moving over a solid substrate that is structured with regularly spaced pinning centers. By analyzing the contour of the front, we derive the normal growth rate and the relaxation coefficient. Both exhibit a 1/t(1/2) time dependence. Moreover, the friction coefficient and the line tension can be determined. Randomly distributed pinning centers cause a fractal contour line, whereas on surfaces that are artificially roughened, self-affine contour lines are observed. The latter exhibit an anomalous roughness exponent of zeta = 0.81+/-0.05.


Asunto(s)
Membranas Artificiales , Fosfolípidos/química , Algoritmos , Colorantes Fluorescentes , Procesamiento de Imagen Asistido por Computador , Modelos Teóricos , Politetrafluoroetileno
17.
J Agric Food Chem ; 49(2): 1009-19, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11262064

RESUMEN

The antioxidative effects of gallic acid, EDTA, and extra emulsifier Panodan DATEM TR in mayonnaise enriched with 16% fish oil were investigated. EDTA reduced the formation of free radicals, lipid hydroperoxides, volatiles, and fishy and rancid off-flavors. The antioxidative effect of EDTA was attributed to its ability to chelate free metal ions and iron from egg yolk located at the oil-water interface. Gallic acid reduced the levels of both free radicals and lipid hydroperoxides but promoted slightly the oxidative flavor deterioration in mayonnaise and influenced the profile of volatiles. Gallic acid may therefore promote the decomposition of lipid hydroperoxides to volatile oxidation products. Addition of extra emulsifier reduced the lipid hydroperoxide levels but did not influence the level of free radicals or the oxidative flavor deterioration in mayonnaisse; however, it appeared to alter the profile of volatiles. The effect of the emulsifier on the physical structure and rheological properties depended on the presence of antioxidants.


Asunto(s)
Antioxidantes/farmacología , Ácido Edético/farmacología , Aceites de Pescado/química , Aditivos Alimentarios , Manipulación de Alimentos , Ácido Gálico/farmacología , Huevos , Excipientes/farmacología , Ácidos Grasos Monoinsaturados , Alimentos , Peróxidos Lipídicos/análisis , Odorantes/análisis , Aceites de Plantas , Aceite de Brassica napus
18.
J Biol Chem ; 276(7): 5189-96, 2001 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-11050086

RESUMEN

The ternary complex factor Elk-1, a major nuclear target of extracellular signal-regulated kinases, is a strong transactivator of serum-responsive element (SRE) driven gene expression. We report here that mature brain neurons and nerve growth factor (NGF)-differentiated PC12 cells also express a second, smaller isoform of Elk-1, short Elk-1 (sElk-1). sElk-1 arises from an internal translation start site in the Elk-1 sequence, which generates a protein lacking the first 54 amino acids of the DNA-binding domain. This deletion severely compromises the ability of sElk-1 to form complexes with serum response factor on the SRE in vitro and to activate SRE reporter genes in the presence of activated Ras. Instead, sElk, but not a mutant that cannot be phosphorylated, inhibits transactivation driven by Elk-1. More pertinent to the neuronal-specific expression of sElk-1, we show it plays an opposite role to Elk-1 in potentiating NGF-driven PC12 neuronal differentiation. Overexpression of sElk-1 but not Elk-1 increases neurite extension, an effect critically linked to its phosphorylation. Interestingly, in the presence of sElk-1, Elk-1 loses its strictly nuclear localization to resemble the nuclear/cytoplasm pattern observed in the mature brain. This is blocked by mutating a normally cryptic nuclear export signal in Elk-1. These data provide new insights into molecular events underlying neuronal differentiation of PC12 cells mediated by the NGF-ERK signaling cascade.


Asunto(s)
Encéfalo/metabolismo , Factor de Crecimiento Nervioso/farmacología , Neuronas/citología , Proteínas Proto-Oncogénicas/fisiología , Transporte Activo de Núcleo Celular , Animales , Anticuerpos/inmunología , Diferenciación Celular , Núcleo Celular/metabolismo , Codón Iniciador , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/inmunología , Proteínas de Unión al ADN/fisiología , Masculino , Neuronas/metabolismo , Células PC12 , Fenotipo , Isoformas de Proteínas/genética , Isoformas de Proteínas/inmunología , Isoformas de Proteínas/fisiología , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/inmunología , Ratas , Ratas Sprague-Dawley , Factores de Transcripción/genética , Factores de Transcripción/inmunología , Factores de Transcripción/fisiología , Activación Transcripcional , Proteína Elk-1 con Dominio ets
20.
Acta Neurochir Suppl ; 76: 55-60, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11450088

RESUMEN

Cerebral ischaemia and reperfusion injury may be exacerbated by leukocyte recruitment and activation. Adhesion molecules play a pivotal role in leukocyte recruitment. We report a prospective study of the potential role of the selectin family of adhesion molecules (E-, P- and L-selectin) in delayed cerebral ischaemia (DID) following aneurysmal subarachnoid haemorrhage. In patients with good grade SAH, we have compared serum concentrations of E-, P- and L-selectin, between patients who do, and do not develop delayed cerebral ischaemia. There was no difference in E-selectin concentration between the two groups (44.0 ng/ml vs. 37.4 ng/ml). Serum P-selectin concentration was significantly higher in patients with DID compared to those patients without DID (149.5 ng/ml vs. 112.9 ng/ml, p = 0.039). Serum L-selectin concentrations were significantly lower in patients with DID (633.8 ng/ml vs 897.9 ng/ml, p = 0.013). We conclude that P- and L-selectin are involved in the pathogenesis of DID following aneurysmal subarachnoid haemorrhage. The results of this study do not elucidate the exact role of each selectin in DID.


Asunto(s)
Edema Encefálico/fisiopatología , Isquemia Encefálica/fisiopatología , Aneurisma Intracraneal/fisiopatología , Selectinas/fisiología , Hemorragia Subaracnoidea/fisiopatología , Encéfalo/irrigación sanguínea , Edema Encefálico/diagnóstico , Edema Encefálico/cirugía , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/cirugía , Humanos , Aneurisma Intracraneal/diagnóstico , Aneurisma Intracraneal/cirugía , Pronóstico , Estudios Prospectivos , Daño por Reperfusión/diagnóstico , Daño por Reperfusión/fisiopatología , Daño por Reperfusión/cirugía , Hemorragia Subaracnoidea/diagnóstico , Hemorragia Subaracnoidea/cirugía
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