Human lactoferrin triggers a mitochondrial- and caspase-dependent regulated cell death in Saccharomyces cerevisiae.

We have previously shown that the antifungal activity of human lactoferrin (hLf) against Candida albicans relies on its ability to induce cell death associated with apoptotic markers. To gain a deeper understanding of the mechanisms underlying hLf-induced apoptosis, we characterized this cell death process in the well-established Saccharomyces cerevisiae model. Our results indicate that hLf induces cell death in S. cerevisiae in a manner that requires energy and de novo protein synthesis. Cell death is associated with nuclear chromatin condensation, preservation of plasma membrane integrity, and is Yca1p metacaspase-dependent. Lactoferrin also caused mitochondrial dysfunction associated with ROS accumulation and release of cytochrome c. Pre-incubation with oligomycin, an oxidative phosphorylation inhibitor, increased resistance to hLf and, accordingly, mutants deficient in the F1F0-ATP synthase complex were more resistant to death induced by hLf. This indicates that mitochondrial energetic metabolism plays a key role in the killing effect of hLf, though a direct role of F1F0-ATP synthase cannot be precluded. Overexpression of the anti-apoptotic protein Bcl-xL or pre-incubation with N-acetyl cysteine reduced the intracellular level of ROS and increased resistance to hLf, confirming a ROS-mediated mitochondrial cell death process. Mitochondrial involvement was further reinforced by the higher resistance of cells lacking mitochondrial DNA, or other known yeast mitochondrial apoptosis regulators, such as, Aif1p, Cyc3p and Aac1/2/3p. This study provides new insights into a detailed understanding at the molecular level of hLf-induced apoptosis, which may allow the design of new strategies to overcome the emergence of resistance of clinically relevant fungi to conventional antifungals.

Synthesis of alpha-GaO(OH) nanorods and their optical properties.

Here, we report the synthesis of uniform alpha-GaO(OH) nanorods on Si substrates at low temperature (200 degrees C) using solvothermal technique. alpha-GaO(OH) uniform nanorods is converted to beta-Ga2O3 after annealing at 900 degrees C under ambient atmosphere. A series of electron microscopy characterizations including scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) are used to understand the growth mechanism of alpha-GaO(OH) nanorods formation. This nanostructure emits defect-related strong PL emissions at blue (492 nm) and green (522 nm) regions and the relative intensities of these emissions peaks can be modified by varying the reaction conditions. Similarly, we also observed room temperature cathodoluminescence (CL) and the uniform CL contrast of the nanorods in their CL image indicates a homogeneous defect distribution along the nanorods.

Microscopic mild focal cortical dysplasia in temporal lobe dual pathology: an electrocorticography study.

BACKGROUND: Associations between electrophysiological and histological findings might provide an insight into the epileptogenicity of mild focal cortical dysplasia (FCD) in patients with temporal lobe epilepsy (TLE) and a dual pathology. SUBJECTS AND METHODS: A total of 22 patients with pharmacoresistant TLE were included in the study, 16 of them with histologically confirmed hippocampal sclerosis (HS) associated with neocortical temporal mild Palmini Type-I FCD subtypes and 6 with HS. Intraoperative electrocorticography (ECoG) recordings were analysed for epileptiform discharge frequency and morphology. Associations between histological, and electrocorticography pattern findings in these patients were analysed. Electroclinical outcomes in these patients were also evaluated. RESULTS: Neocortical areas with mild Palmini Type-I FCD showed a significantly higher spike frequency (SF) recorded in the inferior temporal gyrus than those neocortical areas in patients with HS. There was a tendency to higher spike frequency and lower amplitude in neocortical areas with histopathologic subtype IB FCD in relation with IA during intraoperative ECoG. Post-SF excision and amplitude were significantly lower during neocortical post-excision intraoperative ECoG than during neocortical pre-excision recording. There was no difference found in the clinical outcome between patients with and without FCD. CONCLUSIONS: Intraoperative electrocorticographic interictal spike frequency recorded in the neocortical inferior temporal gyrus may help to characterize the histopathologic subtypes of mild Palmini Type-I FCD in patients with temporal lobe epilepsy (TLE) and a dual pathology. Our data support the epileptogenicity of neocortical mild FCD in TLE and assessments of ECoG patterns are relevant to determine the extent of the resection in these patients which can influence the electroclinical outcome.

Nanocrystalline CdSe thin films of different morphologies in thermal evaporation process.

Cadmium selenide nanocrystalline thin films of quasi-spherical morphology are prepared by evaporating CdSe nanopowders on glass substrates. Slightly oval shaped CdSe particles of about 165 nm average size (in 2-D) could be assembled over glass substrates by controlling the film thickness. Morphologies like assembly of particles, interconnected particles with mosaic-like structures and thin films of smooth surfaces could be prepared simply by controlling film thickness. A mechanism for such morphological variations is proposed. Observed variation of band gap energy in the films is explained in terms of quantum confinement effect and substrate-film interface strain.

Incorporation of Sb in ZnO nanostructures through hydrothermal process.

Incorporation of dopants in optoelectronic semiconductor nanostructures has been a matter of great interest in recent times. While such doping has been performed almost routinely using physical methods, use of low-cost chemical techniques for that purpose is still rare. We incorporated antimony in zinc oxide (ZnO) nanostructures through a low temperature hydrothermal method. In as-grown nanostructures, antimony remains partially in Sb2O3 phase. On thermal annealing at 500 degrees C, it dissociates and antimony incorporates into ZnO mainly by substituting zinc from the crystal lattice. Incorporation of Sb drastically modifies the morphology of the ZnO nanostructures. While incorporation of Sb in low concentration promotes the formation of uniform prismatic ZnO nanorods probably due to catalytic effect, high concentration of Sb causes the formation of rounded shaped nanoparticles due to high interfacial compressive stress. Incorporated Sb in the ZnO nanostructures remains inhomogeneously distributed. The optical band gap of the ZnO nanostructures increases a bit for lightly doped samples but it decreases for heavy doping.

Studies of point defect formation and self-compensation in indium doped ZnO nanorods by STM and STS.

The effect of indium doping on the point defect formation in ZnO nanostructures is studied by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) techniques. While the incorporation of a donor dopant like indium should increase the n-type conductivity of ZnO nanostructures, it has been found that formation of V(Zn) native acceptors in heavily doped ZnO nanostructures produces self-compensation effect, creating acceptor states in their band gap. Presence of both donor and acceptor states in heavily indium doped ZnO nanostructures are probed and identified. The mechanism of formation of such donor and acceptor states is discussed.

Actividades biológicas de Xenophyllum poposum Phil. (Asteraceae), planta del altiplano chileno / No disponible

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Longitudinal analysis of metalloproteinases, tissue inhibitors of metalloproteinases and clinical parameters in gingival crevicular fluid from periodontitis-affected patients.

BACKGROUND: The aim of this work was to improve the assessment of the periodontal disease status through measurements of extracellular matrix metalloproteinases (MMPs) and their tissular inhibitors (TIMPs) in the gingival crevicular fluid from patients diagnosed with chronic periodontitis. METHODS: Gingival crevicular fluid samples from patients (n = 13) were taken from 60 sites initially, and from 51 and 41 sites, respectively, 3 and 6 months after scaling and root planing. Gingival crevicular fluid samples were also taken from healthy subjects (n = 11, 24 sites). The presence of MMP-9 and MMP-8 was assessed by zymography and immunowestern blotting, respectively. The actual MMP activity (gelatinase and collagenase) was measured using the fluorogenic substrate assay. TIMP-1 and -2 levels were measured by immunodot blot. RESULTS: The fluorogenic substrate assay determinations showed higher MMP activity in sites with probing depth > or = 4 mm, with significant reduction post-treatment. Gelatinase activity followed by zymography consisted mainly of MMP-9. A different pattern of MMP-8 in control and patient sites was found. Controls only showed species of a partially active form (69 kDa), whereas patient sites showed a high frequency of the active form (56 kDa), and in some cases the latent form (85 kDa) was also observed. The active form reduced its frequency in sites with probing depth > or = 4 mm. TIMP-1 and -2 levels in patients were significantly lower than in controls, and after treatment the recovery of TIMP-1 level similar to control was observed. CONCLUSION: Significant correlations between the severity of the periodontal disease and the actual MMP activity, the active form of MMP-8 and the low level of both TIMP-1 and TIMP-2 were found.

Tomografía eléctrica cerebral para distinguir las descargas generalizadas primarias de la sincronía bilateral secundaria / Brain electromagnetic tomography distinguishes primary generalised discharges from secondary bilateral synchrony

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The rfaH gene, which affects lipopolysaccharide synthesis in Salmonella enterica serovar Typhi, is differentially expressed during the bacterial growth phase.

We have cloned and sequenced the rfaH gene from Salmonella enterica serovar Typhi strain Ty2. The gene showed a high degree of similarity to the rfaH genes from Escherichia coli K-12 and S. enterica serovar Typhimurium. A rfaH mutant was constructed by site-directed mutagenesis. This mutant produced a rough lipopolysaccharide (LPS), with an incomplete core region. The defect in LPS expression that results from the rfaH mutation was corrected by a plasmid carrying the intact gene. The plasmid-borne rfaH gene also restored normal LPS synthesis in a rfaH mutant of E. coli. Reverse transcription-polymerase chain reaction analyses were performed to determine the effects of various environmental conditions on the expression of rfaH. The transcription of rfaH showed a growth-phase-dependent regulation, with maximal expression at the late exponential phase. Other environmental conditions, such as temperature or medium osmolarity, did not affect transcription of rfaH.

Tomografía eléctrica cerebral en el síndrome perisilviano congénito bilateral / Cerebral electrical tomography in bilateral congenital peri-sylvan syndrome

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Detection of dengue virus neutralizing antibodies in bats from Costa Rica and Ecuador.

Neutralizing antibodies for dengue virus serotypes 1 and 2 and serotypes 2 and 3 were detected in 1998 in 12 of 53 (22.6%) and 3 of 10 (30.0%) bats sampled in Costa Rica and Ecuador, respectively. Dengue is a consistent health problem in the two Costa Rican communities in which bats were sampled. The high percentage of bats with neutralizing antibodies to dengue virus in these two Costa Rican communities suggests that bats may become infected with dengue virus. This appears to be the case in Costa Rica and Ecuador.

[Evoked potentials in the sacred baboon: long-term follow-up of intracerebroventricular infusion of nerve growth factor]. / Potenciales evocados en el babuino sagrado: seguimiento a largo plazo de la infusión intracerebroventricular de factor de crecimiento nervioso.

INTRODUCTION AND OBJECTIVE: It is well known that in aged animals cognitive deficit occurs, homologous with that occurring in Alzheimer's disease in humans, and as has been shown in others species, this may be attenuated by administration of nerve growth factor (NGF). Therefore the basic aim of this study was to make an electrophysiological evaluation of the repercussion that there might be after long-term administration of this neurotropin in the sacred baboon (Papio hamadryas) comparing aged with young animals. MATERIAL AND METHODS: We studied a six year old male and a 39 year old female, after sedation. Long-term intraventricular administration of NGF was carried out using a continuous infusion pump, at a dose of 2.1 micrograms/kg/day. Recordings were made before installing the pump and 1, 3 and 6 months after insertion. A Neuropack Four-mini set for evoked potentials (Nihon Kohden) was used to record auditory evoked potentials from the brain stem and visual evoked potentials due to flash. RESULTS AND CONCLUSION: In both animals there were modifications of their electrophysiological responses. These reached a maximum after one month, more markedly in the older animal and this could possibly be related to the neuromodulator effect of NGF.

[A multidisciplinary approach to the management of cerebral vascular malformations]. / Enfoque multidisciplinario en el manejo de las malformaciones vasculares cerebrales.

INTRODUCTION: Cerebral vascular malformations (CVM) are a heterogeneous group of lesions. One way of classifying them is according to histological criteria, clinical features, imaging findings, electroencephalography and distinctive pathology. OBJECTIVES: To report the results obtained in 16 patients clinically diagnosed as having CVM and operated on in the Centro Internacional de Restauración Neurológica (La Habana, Cuba) between March 1995 and October 1998. We also consider the usefulness of diagnostic tools for neurosurgical management and anatomo-pathological diagnosis. PATIENTS AND METHODS: We review the clinical findings, images, electroencephalograms and diagnostic histology of 16 patients. The gender distribution was 10 men and 6 women who were aged between 9 and 48 years. Stereotaxic resection guided by CAT and angiography was done in all cases. RESULTS: The predominant symptoms were headache and generalized tonic-clonic convulsions. CAT and angiography were helpful in determining the clinical diagnosis and location. The most frequent electroencephalographic finding was focal slowing associated with inactive epileptiform disorders. Histological study showed that there were 3 cases of arteriovenous malformations (AVM), one angioma cavernosa and one mixed vascular malformation (AVM plus angioma cavernosa). The malformation was not resected (it was treated with a clip) in the remaining case. CONCLUSION: Our results show the importance of structural imaging studies and their relationship to functional studies in the presumptive diagnosis of CVM corroborated by post-operative histological diagnosis.

[The use of zygomatic electrodes in the assessment of epileptic patients. Presentation of methodology for recording and assessing a digital EEG]. / Utilización de electrodos cigomáticos en la evaluación de pacientes epilépticos. Presentación de una metodología para el registro y evaluación del EEG digital.

INTRODUCTION AND OBJECTIVES: Electrographic anomalies of the temporal lobe may be seen in 70% of epileptic patients. Focalization if inter-ictal epileptiform discharges makes a major contribution to clinical diagnosis. Also, it is accepted that the detection and interpretation of such anomalies is influenced by the method of recording. Thus the use of additional extracranial electrodes has been shown to significantly increase the sensitivity of inter-ictal or ictal electroencephalograms (EEG) PATIENTS AND METHODS: We present the results of two years work in the Electroencephalogram Laboratory of the International Centre for Neurological Recovery, La Habana, Cuba (CIREN), using zygomatic electrodes for the standard assessment of epileptic patients. Recordings were made using the FCz position as reference electrode instead of the reference electrode (short-circuited ears) used as pre-programmed in the recording module of the software Track Walker 2 for Medicid 3E (used in the Clinical Neurophysiology Laboratories of the National Network). Epileptiform activity was seen on 196 recordings; in 100 (51%) of these, this activity involved the temporal lobe, with strictly temporal localization shown in 25 patients (25%) and in 7 (28%) we recorded focalization on the medial aspect. We present segments of EEGs with epileptiform discharges focalized in the temporal lobe (medial and lateral aspects) in bipolar systems (zygotemporal-parasagittal) and in reference electrodes. CONCLUSIONS: Our results support the usefulness of this methodology for the detection and localization of epileptiform activity in the temporal lobe and suggest an alternative which would increase the diagnostic sensitivity of EEG in epilepsies.

Enfoque multidisciplinario en el manejo de las malformaciones vasculares cerebrales / Interdisciplinary approach in the cerebral vascular malformations

Introducción. Las malformaciones vasculares cerebrales (MVC) comprenden un grupo heterogéneo de lesiones. Una de sus clasificaciones está basada en criterios histológicos, con un cuadro clínico, imagenológico, electroencefalográfico y patológico distintivo. Objetivos. Comunicar los resultados obtenidos en 16 pacientes con diagnóstico clínico de MVC operados en el Centro Internacional de Restauración Neurológica (La Habana, Cuba) desde marzo de 1995 a octubre de 1998. Discutimos asimismo la utilidad de las herramientas diagnósticas para el manejo neuroquirúrgico y el diagnóstico anatomo-patológico. Pacientes y métodos. Se revisa la clínica, las imágenes, el electroencefalograma y el diagnóstico histológico de 16 pacientes. La distribución por sexo fue de 10 varones y 6 mujeres, con un rango de edad entre 9 y 48 años. A todos los casos se les realizó resección estereotáxica guiada por TAC y angiografía. Resultados. Los síntomas predominantes fueron la cefalea y las convulcionestonicoclónicas generalizadas. La TAC y la angiografía ayudaron a precisar el diagnóstico clínico y la localización. El hallazgo más frecuentemente encontrado en el electroencefalograma fueron las alteraciones lentas focales asociadas a rastorno epileptiforme inactivo. La histología mostró 13 casos con malformaciones arteriovenosas (MAV), un angioma cavernoso yuna malformación vascular mixta (MAV más angioma cavernoso) al caso restante no se le resecó la malformación (tratada con clip). Conclusión. Nuestros resultados demuestran la importancia de los estudios imagenológicos estructurales así como su relación con estudios funcionales en el diagnóstico presuntivo de las MVC corroboradas con el diagnóstico histológico postquirúrgico(AU)