Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
J Toxicol Environ Health A ; 65(14): 995-1012, 2002 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-12133233

RESUMEN

The pulmonary effects of two environmentally relevant aldehydes were investigated in nonsensitized or ovalbumin (OA)-sensitized guineapigs (GPs). Four-week-old male Hartley GPs, weighing about 400 g, were intraperitoneally injected with 1 ml of an NaCl solution containing 100 microg OA and 100 mg Al(OH)(3). They were then exposed to either acetaldehyde (200 ppb) or benzaldehyde (500 ppb) for 4 wk (6 h/d, 5 d/wk). At the end of exposure, GPs were challenged with an OA aerosol (0.1% in NaCl) and pulmonary functions were measured. The day after, guinea pigs were anesthetized and several endpoints related to inflammatory and allergic responses were assessed in blood, whole-lung histology, and bronchoalveolar lavage (BAL). Sensitized nonexposed GPs showed bronchial hyperresponsiveness to OA and an increased number of eosinophils in blood and BAL, together with a rise in total protein and leukotrienes (LTB(4) and LTC(4)/D(4)/E(4)) in BAL. In nonsensitized GPs, exposure to acetaldehyde or benzaldehyde did not induce any change in the tested parameters, with the exception of irritation of the respiratory tract as detected by histology and an increased number of alveolar macrophages in animals exposed to acetaldehyde. In sensitized GPs, exposure to acetaldehyde induced a moderate irritation of the respiratory tract but no change in biological parameters linked to the inflammatory and allergic responses. In contrast, exposure to benzaldehyde induced a decrease both in OA-induced bronchoconstriction and in eosinophil and neutrophil numbers in BAL, an increase in the bronchodilatator mediator prostaglandin E(2) (PGE(2)), and a decrease in the bronchoconstrictor mediators LTC(4)/D(4)/E(4). Further investigations are needed to determine if the attenuated response observed in sensitized GPs exposed to benzaldehyde is due to an alteration of the mechanism of sensitization or to a more direct effect on various mechanisms of the allergic response.


Asunto(s)
Acetaldehído/toxicidad , Contaminantes Atmosféricos/toxicidad , Benzaldehídos/toxicidad , Pulmón/efectos de los fármacos , Ovalbúmina/administración & dosificación , Hipersensibilidad Respiratoria/fisiopatología , Acetaldehído/administración & dosificación , Administración por Inhalación , Animales , Benzaldehídos/administración & dosificación , Hiperreactividad Bronquial/inducido químicamente , Líquido del Lavado Bronquioalveolar/citología , Cobayas , Inyecciones Intraperitoneales , Pulmón/citología , Pulmón/inmunología , Masculino , Pruebas de Función Respiratoria , Hipersensibilidad Respiratoria/etiología , Hipersensibilidad Respiratoria/inmunología
2.
Chemistry ; 7(21): 4590-8, 2001 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-11757650

RESUMEN

The syntheses and properties of two calixarene-based fluorescent molecular sensors are reported. These comprise tert-butylcalix[4]arene either with one appended fluorophore and three ester groups (Calix-AMN1). or with four appended fluorophores (Calix-AMN4). The fluorophore is 6-acyl-2-methoxynaphthalene (AMN), which contains an electron-donating substituent (methoxy group) conjugated to an electron-withdrawing substituent (carbonyl group); this allows photoinduced charge transfer (PCT) to occur upon excitation. The investigated fluoroionophores thus belong to the family of PCT fluorescent molecular sensors. In addition to the expected red shifts of the absorption and emission spectra upon cation binding, a drastic enhancement of the fluorescence quantum yield-in an "off- on" fashion comparable to that seen in photoinduced electron transfer (PET) molecular sensors-was observed. For Calix-AMN1. it increases from 10(-3) for the free ligand to 0.68 for the complex with Ca2+. This exceptional behaviour can be interpreted in terms of the relative locations of the npi* and pipi* levels, which depend on the charge density of the bound cation. For Calix-AMN4. in addition to the photophysical effects observed for Calix-AMN1, interactions between the chromophores by complexation with some cations have been found in the ground state (hypochromic effect) and in the excited state (excimer formation). Steady-state fluorescence anisotropy measurements for the system Na+ is included in Calix-AMN4, show a depolarization effect due to energy transfer (homotransfer) between the fluorophores. Regarding the complexing properties, a high selectivity for Na+ over K+, Li+, Ca2+ and Mg2+ was observed in ethanol and ethanol-water mixtures. The selectivity (Na+/other cations) expressed as the ratio of the stability constants was found to be more than 400.

3.
Thromb Haemost ; 80(6): 961-7, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9869168

RESUMEN

Endothelial cells (ECs) in culture synthesize and secrete urokinase-type plasminogen activator (u-PA), but the normal vascular endothelium is believed to synthesize only tissue plasminogen activator (t-PA), which is thought to be responsible for intravascular fibrinolysis. More recently, animal studies have shown that the biological role of u-PA in fibrinolysis has been underestimated, prompting a re-examination of its synthesis by the endothelium. In this study, we investigated whether u-PA was synthesized by non-atherosclerotic endothelial cells in vivo by testing ECs dislodged by venipuncture from 12 normal volunteers and 17 patients admitted for plasmapheresis. The ECs were isolated with an anti-endothelial monoclonal antibody coupled to immunomagnetic beads and characterized by morphology and by labelling for vWF, CD31, and UEA-1 binding. U-PA antigen was found in 50% of the ECs from the normal subjects and in 60% of those from patients. U-PA enzymatic activity on zymograms was detected in 50% of the normal samples and 60% of the patient samples, with the latter being more frequently and more strongly positive. U-PA mRNA was found in all the normal and patient samples tested. The results indicate that u-PA is synthesized by the venous endothelium in vivo but that its expression is highly variable.


Asunto(s)
Endotelio Vascular/enzimología , Activador de Plasminógeno de Tipo Uroquinasa/biosíntesis , Adulto , Biomarcadores , Células Cultivadas , Endotelio Vascular/citología , Inducción Enzimática , Femenino , Fibrinólisis , Humanos , Separación Inmunomagnética , Hibridación in Situ , Masculino , Microscopía Fluorescente , Persona de Mediana Edad , ARN Mensajero/análisis , Activador de Plasminógeno de Tipo Uroquinasa/genética , Venas
4.
Rev Mal Respir ; 13(2): 155-62, 1996.
Artículo en Francés | MEDLINE | ID: mdl-8711234

RESUMEN

This study had, as its aim, to test twelve nebulizers (6 jet, 6 ultrasonic) which are used in the treatment of cystic fibrosis. Devices were connected to a respirator in order to mimic the ventilation of a child and of an adult suffering from cystis fibrosis. Three medications: tobramycine, colistine and amiloride were nebulised. The volume of the recommended solution varied between 1.5 and 13 ml according to the manufacturer. During a session of ten minutes the ultrasonic nebulizer delivered an inhaled volume which was significantly greater than the jet (2.72 +/- 0.98 ml vs 1.22 +/- 0.59 ml, p < 0.0001) for the three drugs. Regarding granulometry, the fraction of particles between 0.5 and 5 microns, was higher with ultrasonic than with pneumatic nebulizer for tobramycine (67.1 +/- 10.7 vs 55.5 +/- 11.5%, p < 0.001) and amiloride (66.4 +/- 9.2% vs 58.1 +/- 15%, p < 0.05%). The variation of concentration due to nebulisation were independent of the type of apparatus but influenced by the drug since concentration was increased for tobramycine (+10.5 +/- 18.6%) and amiloride (+13.4 +/- 8/9%). In summary the effective fraction resulting from the inhalable fraction, from granulometry and from changes in concentration was significantly greater for ultrasonic than for jet nebrulizer (17.3 +/- 6.7% vs 9.7 +/- 9.6%, p < 0.001). This study underlines the great variability of the performance of aerosols generators and therefore the need for an accurate evaluation of nebulizer performances in order to prescribe the best nebulizer/drug association in clinical practice.


Asunto(s)
Fibrosis Quística/tratamiento farmacológico , Nebulizadores y Vaporizadores/normas , Administración por Inhalación , Adulto , Aerosoles/administración & dosificación , Amilorida/administración & dosificación , Antibacterianos/administración & dosificación , Niño , Colistina/administración & dosificación , Diuréticos/administración & dosificación , Diseño de Equipo , Ergonomía , Humanos , Ensayo de Materiales , Tamaño de la Partícula , Tobramicina/administración & dosificación
5.
Environ Health Perspect ; 97: 103-7, 1992 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1396442

RESUMEN

The origin of immune dysfunctions that are observed in pneumoconiotic miners still remains unknown. There is evidence that the carbohydrate moiety of membrane glycoconjugates is of primary importance in many functions of immunocompetent cells. The glycosylation, and especially the sialylation level of membrane components of various lymphocyte and macrophage subsets, vary depending on the state of cellular differentiation and activation. Sialidases, which may regulate the amount of sialic acids exposed on the cell membrane, can thus be considered as immunoregulatory enzymes. In this report, the sialidase activity has been measured in alveolar macrophages (AM) and in cell-free bronchoalveolar lavage fluid (BALF) from guinea pigs exposed for 4 months to coal mine dust at a concentration of 300 mg/m3. The samples were collected by bronchoalveolar lavage 2 months after cessation of exposure. The sialidase activity in the cell-free fluid and in the purified alveolar macrophages showed a 10-fold decrease (p less than 0.001). Kinetic parameters of the enzyme such as Km and optimum pH did not change. This changed activity was specific for sialidase, as two other lysosomal glycosidases, beta-galactosidase and N-acetylglucosaminidase, showed unchanged activities. These results suggest the possibility that, by inducing a decreased sialidase activity, exposure to coal mine dust may lead to a modified expression of AM membrane-associated sialic acids giving rise to altered immune functions (i. e., phagocytosis, antigen processing, response to cytokines, etc.).


Asunto(s)
Carbón Mineral/efectos adversos , Macrófagos Alveolares/enzimología , Neuraminidasa/metabolismo , Neumoconiosis/enzimología , Animales , Líquido del Lavado Bronquioalveolar/enzimología , Cobayas , Macrófagos Alveolares/efectos de los fármacos , Macrófagos Alveolares/patología , Masculino , Neumoconiosis/etiología , Neumoconiosis/patología
6.
Rev Med Interne ; 11(1): 76-8, 1990.
Artículo en Francés | MEDLINE | ID: mdl-2183326

RESUMEN

A case of isolated trigeminal sensitive neuropathy revealed by a nasal ulceration is reported. Such case is quite unusual and requires a very thorough search for any local lesion or general pathology. The treatment is often disappointing.


Asunto(s)
Enfermedades Nasales/etiología , Nervio Trigémino , Adulto , Enfermedades de los Nervios Craneales/complicaciones , Humanos , Masculino , Úlcera/etiología
7.
Rev Neurol (Paris) ; 145(3): 201-7, 1989.
Artículo en Francés | MEDLINE | ID: mdl-2749097

RESUMEN

Long latency auditory evoked potentials were recorded in 50 patients with Parkinson's disease, some case were also investigated by the Rapid Evaluation of Cognitive Functions test (RECF) and Trail Making A test (TMA). Latencies of P2, N2 and P300 waves were longer in the parkinsonian group than in a control group matched for age. Latencies of N2 and P300 waves were correlated significantly with scores for RECF and TMA presumed to be sensitive to organic brain lesions. On the other hand no significant correlation was found between RECF and P1 and P2 latencies. In addition, correlation was lacking between Verbal Automatism test scores, presumed to be resistant to organic brain lesions, and P300 wave latencies. Cognitive evoked potential (CEP) latency increases with age in normal subjects. In the parkinsonian group the coefficient of correlation between these two factors was lower but still significant. The parkinsonian patients with dementia as defined by DSM III criteria, or an RECF score of less than 46, showed longer N2 and P300 latencies but no significant difference in N1 and P2 latencies. In contrast, comparison of P300 and N2 wave latencies in depressed and non-depressed parkinsonian patients failed to show any significant difference. The bilateral akinetic forms had marked lengthening of P300 wave latencies and a lower TMA score. Neither the duration of the disease, type of treatment, duration of L-Dopa therapy significantly influenced the latency of cognitive event-related potentials.


Asunto(s)
Trastornos del Conocimiento/fisiopatología , Potenciales Evocados Auditivos , Enfermedad de Parkinson/fisiopatología , Factores de Edad , Femenino , Humanos , Levodopa/uso terapéutico , Masculino , Pruebas Neuropsicológicas , Enfermedad de Parkinson/tratamiento farmacológico , Tiempo de Reacción
8.
Rev Neurol (Paris) ; 145(12): 859-61, 1989.
Artículo en Francés | MEDLINE | ID: mdl-2616970

RESUMEN

A case of occlusion of the middle cerebral artery during a treatment with gonadotropin is reported. Such cases are unusual when one considers that these treatments are widely used. They occur after a markek ovarian hyperstimulation syndrome. Treatment is purely preventive with clinical, laboratory and ultrasonic examinations before injection of beta-HCG.


Asunto(s)
Arteriopatías Oclusivas/inducido químicamente , Arterias Cerebrales/fisiopatología , Gonadotropinas Hipofisarias/efectos adversos , Inducción de la Ovulación , Adulto , Arterias Cerebrales/efectos de los fármacos , Femenino , Humanos
12.
Acta Neurol Belg ; 87(1): 12-9, 1987.
Artículo en Francés | MEDLINE | ID: mdl-3577657

RESUMEN

The blink reflex combined with stimulo-detection of the facial nerve was studied in 50 patients presenting Guillain-Barré polyradiculoneuritis. The reflex was normal in more than half the cases. The most frequent electrological picture consisted in bilateral lengthening of the early and late reflex responses of the blink reflex with unilateral or bilateral increase of motor facial latency. The blink reflex showed various abnormalities in slightly more than one third of the cases of polyradiculoneuritis presenting no clinical signs of facial involvement, thus constituting subclinical lesional evidence of the reflex arc.


Asunto(s)
Parpadeo , Nervio Facial/fisiopatología , Polirradiculopatía/fisiopatología , Reflejo Anormal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Electrofisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polirradiculopatía/diagnóstico , Tiempo de Reacción
13.
Rev Neurol (Paris) ; 143(4): 303-5, 1987.
Artículo en Francés | MEDLINE | ID: mdl-3629081

RESUMEN

A case of carpal tunnel syndrome with skin ulcerations and osteolysis is reported. Such cases are unusual. There was a sensory and motor deficit with chronic ulcerations on the palmar surface of the third phalanx of the medius. The distal phalanx of the forefinger had been lost due to osteolysis. Surgical treatment is said to be followed by a healing of the ulcerations.


Asunto(s)
Síndrome del Túnel Carpiano/complicaciones , Osteólisis/etiología , Úlcera Cutánea/etiología , Anciano , Femenino , Dedos , Humanos
14.
Neurochirurgie ; 33(3): 216-9, 1987.
Artículo en Francés | MEDLINE | ID: mdl-3614497

RESUMEN

Three cases of spinal cord tumor, revealed by hydrocephalus, are reported. Two patients showed symptoms of increased intracranial pressure and the third one presented himself with ataxic gait without intellectual impairment nor incontinence. In two cases ventriculo atrial shunt was initially inserted and the correct diagnosis was made only later on myelogram because lombosciatalgia or syndrome of the cauda equina. Clinical outcome was satisfying after surgical removal of the tumor. The nature of which was a neurinoma of the cauda equina; a lumbar intradural granuloma and an ependymoma of the cauda equina. The mechanism by which spinal cord tumors raised intracranial hypertension is discussed.


Asunto(s)
Hidrocefalia/etiología , Seudotumor Cerebral/etiología , Neoplasias de la Médula Espinal/complicaciones , Adolescente , Adulto , Cauda Equina , Ependimoma/complicaciones , Femenino , Granuloma/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Neurilemoma/complicaciones , Enfermedades de la Médula Espinal/complicaciones
15.
Rev Med Interne ; 8(1): 75-8, 1987.
Artículo en Francés | MEDLINE | ID: mdl-3563167

RESUMEN

Rendu-Osler-Weber disease is a generalized vascular dysplasia which also involves the central nervous system. The neurological manifestations of the disease are due either to primary intracranial or spinal vascular lesions or to neurological complications of other visceral lesions, notably those of the lung (arteriovenous fistulae). The prevention of ischaemic or infectious cerebral accidents rests on the anatomical (excision) or functional (selective embolization) exclusion of pulmonary arteriovenous fistulae, when present.


Asunto(s)
Enfermedades del Sistema Nervioso/etiología , Telangiectasia Hemorrágica Hereditaria/complicaciones , Adulto , Absceso Encefálico/etiología , Hemiplejía/etiología , Humanos , Masculino , Meningitis/etiología , Persona de Mediana Edad
16.
Artículo en Francés | MEDLINE | ID: mdl-3764040

RESUMEN

Twenty-one diabetic subjects were studied; all manifested fasting hyperglycemia and elevated Hb A1C. Motor conduction velocity of the median, ulnar and peroneal nerves; F wave of the peroneal nerve; sensory conduction velocity and sensory potential amplitude of the median and ulnar nerves and H reflex were determinated immediately before and after two days of strict glucose control with an artificial endocrine pancreas. A significant and acute improvement of some electrophysiological parameters led us to presume that repair of structural lesions would be unlikely. Only a metabolic disturbance, due to hyperglycemia, can be rapidly corrected.


Asunto(s)
Neuropatías Diabéticas/tratamiento farmacológico , Sistemas de Infusión de Insulina , Adolescente , Adulto , Neuropatías Diabéticas/fisiopatología , Humanos , Persona de Mediana Edad , Neuronas Motoras/fisiología , Conducción Nerviosa , Neuronas Aferentes/fisiología , Nervios Periféricos/fisiopatología , Reflejo Monosináptico
17.
Presse Med ; 15(13): 603-6, 1986 Mar 29.
Artículo en Francés | MEDLINE | ID: mdl-2939417

RESUMEN

Eighty-seven patients (mean age 73 years) with histologically proven Horton's disease were followed up in 5 different specialized hospital units from 1970 to 1984. Except for one patient treated exclusively with antimalarials, all were under corticosteroids. The mean initial dose of prednisone or equivalent was 0.7 mg/kg/day and the mean maintenance dose, 10 mg/day. Steroids could be discontinued in 21 cases after 36 months on average; the other patients could not be weaned, even though 4 of them had been on steroids for more than 10 years. Side-effects were noted in 43 cases. Twenty-four patients died, mostly of cardiovascular diseases. Survival rates were 89 +/- 6.35% at 1 year, 60.2 +/- 8.7% at 5 years and 48 +/- 11.3% at 10 years. In the long run, mortality in our series proved to be exactly the same as in the general population. Nineteen patients had ocular manifestations of giant cell arteritis always from the onset, except for a fall in visual acuity; 26 relapses were observed in 18 patients, either during reduction of steroid dosage (21 cases) or after withdrawal (5 cases). In 2 cases histology showed typical lesions of giant cell arteritis after 41 and 50 months respectively under corticosteroid therapy.


Asunto(s)
Arteritis de Células Gigantes/tratamiento farmacológico , Prednisona/uso terapéutico , Anciano , Cloroquina/uso terapéutico , Ciclofosfamida/uso terapéutico , Dapsona/uso terapéutico , Quimioterapia Combinada , Femenino , Arteritis de Células Gigantes/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Prednisona/administración & dosificación , Prednisona/efectos adversos , Pronóstico , Recurrencia , Estudios Retrospectivos , Factores de Tiempo
19.
Acta Neurol Belg ; 85(5): 310-7, 1985.
Artículo en Francés | MEDLINE | ID: mdl-4072617

RESUMEN

Study of the blink reflex and stimulodetection of the facial nerve in 21 diabetics with chronic hyperglycemia (HbA1C: 12.17 +/- 2.34%) shows normal or slightly prolonged R1, R2 and M latent periods in most cases. Forty-eight hour metabolic correction by artificial pancreas produces an overall improvement in the latent periods of the blink reflex, while the motor latent period of the facial nerve remained unchanged. The improvement, also observed in studies of limb responses, points towards a metabolic process directly related to the hyperglycemia.


Asunto(s)
Diabetes Mellitus Tipo 1/terapia , Neuropatías Diabéticas/terapia , Enfermedades del Nervio Facial/terapia , Sistemas de Infusión de Insulina , Parpadeo , Neuropatías Diabéticas/diagnóstico , Estimulación Eléctrica , Enfermedades del Nervio Facial/diagnóstico , Humanos , Tiempo de Reacción
20.
Pathol Biol (Paris) ; 33(8): 804-9, 1985 Oct.
Artículo en Francés | MEDLINE | ID: mdl-3903618

RESUMEN

The study of 430 cerebrospinal fluids resulting from a neurological department showed 67 pathological medical cases according to following tests: intrathecal IgG synthesis and/or restricted heterogeneity with immuno-electrophoresis. We established a biological classification to approach the different etiologies. This classification was used for multiple sclerosis for which various strictly clinical classifications are not always able to diagnose the illness, as we show it for one of them.


Asunto(s)
Proteínas del Líquido Cefalorraquídeo/análisis , Enfermedades del Sistema Nervioso/líquido cefalorraquídeo , Proteínas Sanguíneas/análisis , Humanos , Inmunoelectroforesis , Inmunoglobulina G/biosíntesis , Esclerosis Múltiple/líquido cefalorraquídeo , Esclerosis Múltiple/inmunología , Enfermedades del Sistema Nervioso/diagnóstico , Enfermedades del Sistema Nervioso/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...