Entamoeba histolytica: expression and localization of Gal/GalNAc lectin in virulent and non-virulent variants from HM1:IMSS strain.

We have purified Gal/GalNAc lectin from Entamoeba histolytica by electroelution. The purified protein was used to immunize rabbits and obtain polyclonal IgG's anti-lectin. These antibodies were used as tools to analyze the expression and localization of the amoebic lectin in both virulent (vEh) and non-virulent (nvEh) variants of axenically cultured HM1:IMSS strain. vEh is able to induce liver abscesses in hamsters, whereas nvEh has lost this ability. In vitro, amoebic trophozoites from both variants equally express this protein as shown by densitometric analysis of the corresponding band in Western blots from lysates. In both types of trophozoites, the pattern of distribution of the lectin was mainly on the surface. We have also compared by immunohistochemistry the presence and distribution of lectin in the in vivo liver lesions produced in hamsters. In order to prolong the survival of nvEh to analyze both variants in an in vivo model, hamsters inoculated with nvEh were treated with methyl prednisolone. Our results suggest that the Gal/GalNAc lectin is equally expressed in both nvEh and vEh.

Cysteine proteinase activity is required for survival of the parasite in experimental acute amoebic liver abscesses in hamsters.

Axenic trophozoites of Entamoeba histolytica strain HM1-IMSS grown in vitro in the presence of E-64, a potent irreversible inhibitor of cysteine proteinases, preserved their viability, their rate of replication, their resistance to complement, their haemolytic capacity and their ability to destroy target cells, despite complete inhibition of total cysteine proteinase activity. On the other hand, their erythrophagocytic capacity and their ability to decrease TER of MDCK cells was partially decreased. The same trophozoites injected into the portal vein of hamsters receiving a maintaining dose of E-64 failed to cause tissue damage and were rapidly eliminated. Our results suggest that amoebic cysteine proteinase activity is not required for amoebic functions in in vitro conditions, but that it becomes necessary for survival of trophozoites in in vivo conditions, whatever other role (if any) it may play in the parasite's virulence.

Inflammation, complement, ischemia and amoebic survival in acute experimental amoebic liver abscesses in hamsters.

We have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (AEALAH). In hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. Focal liver ischemia, always present in control AEALAH with inflammation and tissue destruction, was reproduced in radiated hamsters by injection of amoebae mixed with Superdex microspheres, but again in the absence of inflammation, amoebae caused no liver damage and disappeared in 24 h. In hamsters made hypocomplementemic by injection of purified cobra venom factor (CVF), amoebae caused AEALA indistinguishable from controls, but in leukopenic + hypocomplementemic hamsters, amoebae were unable to produce lesions and disappeared from the liver in 48 h. We conclude that inflammation and tissue damage are required for the survival of amoebae in AEALAH and for the progression of the experimental disease.

Efectos secundarios de los antidepresivos / Adverse events of antidepressants

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Hallux valgus y cirugía mayor ambulatoria / Hallux valgus and outpatient major surgery

Objetivo. Demostrar la eficacia de la unidad de cirugía mayor ambulatoria (CMA) en el coste-proceso de la patología hallux valgus en la gestión de los recursos sanitarios. Material y método. Se analizó el proceso hallux valgus en pacientes intervenidos durante el año 1995 mediante ingreso rutinario y en el año 1999 a través de ingreso por la unidad de CMA bajo los parámetros de coste por proceso de acuerdo con la unidad ponderada asistencial (UPA) y la calidad asistencial evaluando el dolor, nauseas o vómitos, fiebre, sangrado y grado de satisfacción en las primeras 24 horas. Resultados. Se objetivó que el coste por proceso en los pacientes ingresados de forma rutinaria fue de 2,5 UPA médicas frente a 0,25 UPA médicas en los ingresados por CMA, no encontrándose diferencias en cuanto a los parámetros evaluados en el control de calidad. Conclusiones. El proceso hallux valgus debe incluirse dentro de la cartera de servicios de Traumatología en la unidad de CMA, ya que reduce de una forma considerable el coste sanitario. No se apreció ninguna diferencia en relación con la calidad asistencial y el grado de satisfacción en los pacientes intervenidos mediante CMA o mediante ingreso convencional. Es esencial la correcta selección del paciente, la información que se le ofrece y la motivación de los profesionales (AU)

Fibrosarcoma epitelioide esclerosante. Un diagnóstico complicado / Sclerosing epithelioid fibrosarcoma. A complicated diagnosis

El peculiar patrón histológico de esta infrecuente lesión, recientemente descrita, denominada fibrosarcoma epitelioide esclerosante contribuye a confundirla con otras lesiones benignas o con sarcomas agresivos. El caso que se presenta muestra ambos extremos. Se trata de un varón de 40 años intervenido en dos ocasiones de una tumoración en la planta del pie y diagnosticado en la última de ellas como sarcoma sinovial monofásico hace 9 años. Se aplicaron técnicas histológicas e inmunohistoquímicas estándar. La lesión se caracterizaba por una proliferación de células epitelioides con citoplasma claro dispuestas en cordones y una prominente esclerosis hialina. Las imágenes de mitosis eran escasas. Las células tumorales mostraron una positividad a la tinción con vimentina y se detectaron citoqueratinas focalmente con CAM 5.2. Posteriormente, y debido a la evolución clínica favorable, se revisó de nuevo el caso y se clasificó el tumor como fibrosarcoma epitelioide esclerosante basándose en otros casos publicados recientemente en la literatura. En la actualidad el paciente se encuentra completamente asintomático. Se remarca en este artículo la importancia del patrón de crecimiento histológico del fibrosarcoma epitelioide esclerosante y la precaución en la valoración inmunohistoquímica para evitar un diagnóstico erróneo, fundamental para establecer un tratamiento y un pronóstico adecuados (AU)

[Acute liver failure as presentation form of small cell carcinoma of the lung]. / Insuficiencia hepática aguda como forma de presentación de un carcinoma microcítico de pulmón.

Metastatic infiltration of the liver is an uncommon cause of acute hepatic failure. We describe the case of a 55-yr-old man who presented with signs and symptoms of liver disease. Diagnostic testing revealed a small cell carcinoma of the lung with massive hepatic metastases.

Electrical source analysis by brain mapping techniques.

Brain EEG mapping techniques are employed in our department as a preliminary device for the selection of patient tributaries for more complex neurophysiological techniques: EEG combined with video-filming, foramen ovale electrodes, depth and subdural electrodes etc. Different methods of brain EEG mapping may be employed for the localization of the origin of epileptic discharges: power maps based on a FFT method; power maps based on instantaneous EEG amplitude; and in the last few years, new dipole programs working with the dipole localization method, the so-called 'inverse solution', that indicates the existence of one or more dipoles as sources of discharges, and their localization in a coordinate axis oriented in the three space directions. Brain EEG mapping has the advantage of low cost, but its main inconvenience is the relatively low level of accuracy in the localization of the sources. Neuromagnetic techniques give the best level of accuracy in source localization, but their cost is very high. The final considerations would be how much neuromagnetic techniques improve the results obtained by brain mapping techniques, and the specific areas where these techniques should be assigned.

Role of cysteine proteinases of Entamoeba histolytica on the cytopathogenicity of axenic trophozoites on rat and hamster hepatocytes in vitro.

The role of amebic cysteine proteinase(s) on the in vitro cytotoxic and cytolytic effects of axenic trophozoites of a virulent strain (HM-1) of Entamoeba histolytica has been studied using freshly isolated rat and hamster hepatocytes as target cells. The cytotoxic effect was defined as cell killing without loss of cell structure and the cytolytic effect as cell disintegration. Incubation experiments of axenic trophozoites with rat or hamster liver cells in the presence and absence of bovine serum, of several proteinase inhibitors, and of galactose, galactosamine, and cysteine, at various ameba:liver cell ratios, different temperatures, and for several time periods, suggest that amebic cysteine proteinase is not involved in the cytotoxic effect but is essential for the cytolytic effect. This suggestion is supported by additional observations made with Transwell chambers, which effectively prevent contact between amebas and target cells, and by experiments with a fraction of an extract of lysed amebas that contained most of their cysteine proteinase activity.

[Hemispheric differences in visual evoked potentials during the discrimination of consonants and signs]. / Diferencias hemisféricas en potenciales evocados visuales durante la discriminación de consonantes y de signos.

Visual evoked responses were recorded in response to a series of consonants and non-linguistic signs randomly presented. We compared, with a sample of 16 young volunteers, P300 and N400 latency and amplitude in order to detect possible asymmetries. Results in amplitude showed a significant asymmetry within right hemisphere, both in P300 and N400 components. Latency results failed to present any significant difference during the discrimination of consonants, while non-linguistic signs discrimination reflect an asymmetrical tendency in P300 component.

[Brain mapping studies in dyslexia]. / Estudios de cartografía cerebral en la dislexia.

Brain EEG mapping has been recorded during three different conditions, rest closed eyes, rest open eyes, and reading task, in a group of 22 dyslexic children, age mean 9.3 years, range 8-11, and control group of normal readers of the same age. All the subjects were right-handed, and laterality was assessed through the Edinburgh test. The individual maps in dyslexic and controls were averaged, and mean maps of both groups were obtained for a very different experimental condition. Rest closed eyes maps of dyslexics and controls disclose a powerful and symmetric alpha over occipital areas, with higher energy peak at 8.5-9.5 Hz., without significant differences in both groups. Brain maps centered in the fast beta band, 18-25 Hz., disclose significant differences in control group versus dyslexics, with more power in control group over all areas. Our findings suggest less adequate brain activation in dyslexics during reading tasks.

[Evaluation of the therapeutic effect of flumazenil in hepatic encephalopathy using cerebral cartography]. / Evaluación del efecto terapéutico del flumazenil en la encefalopatía hepática mediante cartografía cerebral.

We investigated the therapeutic effect of flumanezil on acute and chronic hepatic encephalopathy in a group of cirrhotics; its efficacy was evaluated using clinical data and neurophysiologic examination, e.g. brain mapping. Flumazenil was not found to induce significant changes in the clinical status or in maps of the cerebral activity of patients with chronic encephalopathy. In acute encephalopathy, flumazenil improved clinical status, as was confirmed neurophysiologically by improved cerebral activity on brain mapping.

[Study of cognitive functions in autistic children by means of electrical brain mapping]. / Estudio de funciones cognitivas en niños autistas mediante cartografía eléctrica cerebral ("mapping").

Brain electrical activity of 20 autistic children and 19 controls, age range 7-13 years, was recorded employing brain mapping technics, during different test conditions: closed eyes, open eyes, listening music, puzzle task, receptive language, expressive language, writing and reading. The maps let us to analyze the differentiation and topographic organization of brain electrical activity, and the changes induced by psychological tasks over the different brain areas. The autistics children show, versus controls, slowed brain electrical activity, less organization and topographic differentiation, and also poor reactivity to the different test conditions in relationship with the ethiological diversity of this syndrome.

[Roberts-SC phocomelia syndrome: cytogenetic findings and clinical variability in three brothers]. / Síndrome de Roberts-SC focomelia: hallazgos citogenéticos y variabilidad clínica en tres hermanos afectos.

Three sibs with Roberts syndrome SC-phocomelia are presented. The first one, a nine years old girl, with a malformative syndrome consistent with SC-phocomelia: symmetrical reductive malformations of the upper limbs; flexion contractures of both knee joints; multiple minor anomalies, including hemangioma of the face, hypoplastic nose, dysplastic ears and scanty, silvery blond hair; intrauterine and extrauterine growth retardation; psychomotor and mild mental retardation. Cytogenetic study reveals a centromeric abnormality consistent with an unusual sister chromatid disjunction in all metaphases, that can also be a useful tool in prenatal diagnosis. Next two sibs were males and offspring of a twin pregnancy and were found to have a malformative syndrome consistent with Roberts syndrome: low birth weight; dysplastic ears; hypertelorism, exophthalmos and cloudy corneas; bilateral cleft lip and cleft palate; severe reductive defects in both upper limbs and only syndactylia in the lower ones. Both sibs died soon after delivery. Autosomic recessive pattern of inheritance of this disorder, presentation in the same sibship of Roberts and SC-phocomelia syndromes, as different degrees of expression of the same disorder, and relationship of cytogenetic findings with cell division are discussed.