Remediation of soils contaminated with methomyl using electrochemically produced gaseous oxidants.

This prospective work focuses on the use of two different gaseous oxidants (chlorine dioxide and ozone) to remediate soil polluted with methomyl in two different applications: ex-situ and in-situ. In the first, the soil washing is integrated with the bubbling of the oxidant, while in the second, the gas was introduced by a perforated pipe located sub-superficially. Regarding the soil washing treatment, results demonstrate that direct use of ozone is not very efficient, although an important improvement is obtained following activation with hydrogen peroxide or UV light. In contrast, chlorine dioxide exhibited complete methomyl depletion from the soil, although with higher energy consumption and technical complexity compared to ozone. The direct dosing of the gaseous oxidants in perforated pipes is effective, achieving methomyl removals of 7.8 % and 9.2 % using ozone and chlorine dioxide, respectively. In these cases, soil conditions are not significantly modified, which becomes an important advantage of the technology as compared with other electrochemically assisted soil remediation process, in which large regions of the treated soil are affected by important changes in the pH or by depletion of ions. This lower impact makes these novel technologies more promising for further evaluations.

Treatment of Organics in Wastewater Using Electrogenerated Gaseous Oxidants.

This work focuses on the comparison of the performance of direct electrochemical oxidation with indirect electrolysis mediated by gaseous oxidants in the treatment of diluted wastewater. To do this, energy consumptions of the electrolysis using mixed metal oxide (MMO) electrodes are compared with those required for the production and use of chlorine dioxide in the degradation of methomyl contained in aqueous solutions. Results demonstrate the feasibility of the mediated oxidation process and that this process is competitive with direct oxidation. The oxidants are produced under optimized conditions using the same anodic material applied for the direct degradation of organics, thus avoiding efficiency losses associated with mass transfer limitations in the degradation of dilute organic solutions. Thus, using the ClO2 gaseous oxidant, a concentration of 0.1 mM of methomyl from a solution containing 500 mL is completely removed with an energy consumption as low as 50 Wh. The application of the same energy to a direct electrolytic process for treating the same wastewater can only reach less than half of this removal. These findings may have a very important application in the use of electrochemical technology to achieve the remediation of persistent pollutants in wastewater, where their low concentrations typically make direct processes very inefficient.

Adsorptive interaction of peroxymonosulfate with graphene and catalytic assessment via non-radical pathway for the removal of aqueous pharmaceuticals.

Graphene has been applied as a catalyst in peroxymonosulfate (PMS) activation for the removal of pharmaceuticals in water. Firstly, a kinetic adsorption study of PMS was developed, fitting the results to the Elovich's equation. Moreover, the influence of the main variables in the adsorptive process such as pH, initial PMS concentration, and graphene dose were assessed. Secondly, the degradation of diclofenac as a target compound was studied comparing PMS-catalytic versus adsorption processes. PMS-catalytic process enhanced the removal of the micropollutant if compared to adsorption when using a low dose of graphene (less than 50 mg L-1) or after surface saturation. Studies using radical scavengers suggested the lack of radicals in the process, suggesting the non-radical activation of PMS. Thirdly, the adsorption versus PMS-catalytic processes were also compared for the oxidation of a mixture of three antibiotics (norfloxacin, tetracycline and sulfamethoxazole) with different chemical structure. PMS-catalytic activation was more effective for the removal of those compounds that presented less affinity towards adsorption onto the graphene surface. Finally, characterization of the fresh and PMS-treated material was performed. Graphene demonstrated to be stable after its use as catalysts in PMS activation, suffering only slight transformation of the surface oxidation groups.

Omental therapy for primary progressive aphasia with tau negative histopathology: 3 year study.

OBJECTIVE: Omentum transposition surgery (OT) applied to various neurodegenerative disorders has produced clinically significant improvement, which may be due to omentally-derived factors. To evaluate the clinical effect of left hemisphere OT in a primary progressive aphasia (PPA) patient, 3 year follow-up data were analysed. METHODS: Left hemisphere OT was performed on a 68-year-old male with PPA, characterized by moderate dementia and severe expressive aphasia with relatively preserved comprehension, object recognition and visual-spatial abilities. He was longitudinally assessed with cognitive, functional, behavioral and brain HMPAO SPECT measures pre-OT, at baseline and every 3-6 months for 34 months. RESULTS: All measures improved above baseline for >20 months and persisted at or above baseline for 34 months. Cortical activity increased by a maximum of 21% underneath transposed omentum and in synaptically connected areas, and persisted in >50% of the cortex for at least 12 months. Subjectively, family members observed improved verbal and non-verbal communication. CONCLUSION: OT produced a sustained, beneficial treatment effect in PPA and warrants further clinical and basic research to identify explanatory factors.

Sono- and photoelectrocatalytic processes for the removal of ionic liquids based on the 1-butyl-3-methylimidazolium cation.

In this work, sono- and photoelectrolysis of synthetic wastewaters polluted with the ionic liquids 1-Butyl-3-methylimidazolium acetate (BmimAc) and chloride (BmimCl) were investigated with diamond anodes. The results were compared to those attained by enhancing bare electrolysis with irradiation by UV light or with the application of high-frequency ultrasound (US). Despite its complex heterocyclic structure, the Bmim+ cation was successfully depleted with the three technologies that were tested and was mainly transformed into four different organic intermediates, an inorganic nitrogen species and carbon dioxide. Regardless of the technology that was evaluated, removal of the heterocyclic ring is much less efficient (and much slower) than oxidation of the counter ion. In turn, the counter ion influences the rate of removal of the ionic liquid cation. Thus, the electrolysis and photoelectrolysis of BmimAc are much less efficient than sonoelectrolysis, but their differences become much less important in the case of BmimCl. In this later case, the most efficient technology is photoelectrolysis. This result is directly related to the generation of free radicals in the solution by irradiation of the electrochemical system with UV light, which contributes significantly to the removal of Bmim+.

Electrolysis with diamond anodes: Eventually, there are refractory species!

In this work, synthetic wastewater polluted with ionic liquid 1-butyl-3-methylimidazolium (Bmim) bis(trifluoromethanesulfonyl)imide (NTf2) undergoes four electrolytic treatments with diamond anodes (bare electrolysis, electrolysis enhanced with peroxosulfate promoters, irradiated with UV light and with US) and results obtained were compared with those obtained with the application of Catalytic Wet Peroxide Oxidation (CWPO). Despite its complex heterocyclic structure, Bmim+ cation is successfully depleted with the five technologies tested, being transformed into intermediates that eventually can be mineralized. Photoelectrolysis attained the lowest concentration of intermediates, while CWPO is the technology less efficient in their degradation. However, the most surprising result is that concentration of NTf2- anion does not change during the five advanced oxidation processes tested, pointing out its strong refractory character, being the first species that exhibits this character in wastewater undergoing electrolysis with diamond. This means that the hydroxyl and sulfate radicals mediated oxidation and the direct electrolysis are inefficient for breaking the C-S, C-F and S-N bounds of the NTf2- anion, which is a very interesting mechanistic information to understand the complex processes undergone in electrolysis with diamond.

Musical brains: a study of spontaneous and evoked musical sensations without external auditory stimuli.

CONCLUSIONS: Our observations confirm that musical sensations with no external stimuli, either spontaneous or evoked, occur in normal individuals and that a biological substrate can be demonstrated by brain single photon emission computed tomography (SPECT). OBJECTIVES: There are individuals, usually musicians, who are seemingly able to evoke and/or have spontaneous musical sensations without external auditory stimuli. However, to date there is no available evidence to determine if it is feasible to have musical sensations without using external sensory receptors, or if there is a biological substrate for these sensations. SUBJECTS AND METHODS: A group of 100 musicians and another of 150 otolaryngologists were asked if they had spontaneous musical auditory sensations and/or were capable of evoking them. SPECT evaluations with Tc(99m)-HMPAO were conducted in six female musicians while they were evoking these sensations or, in one case, while she was having them spontaneously. In three of them an additional SPECT was conducted in basal conditions (having been asked to avoid evoking music). RESULTS: In all, 97 of 100 musicians had spontaneous musical sensations; all 100 could evoke and modify them. Of the 150 otolaryngologists, 18 (12%) were musicians. Of the 132 nonmusicians, spontaneous musical sensations occurred in 52 (39.4%), 72 (54.5%) could evoke and 23 (17.4%) were able to modify them, 58 (43.9%) did not have spontaneous musical sensations nor could they evoke them. The musical sensations of the 72 otolaryngologists that could evoke were less elaborated than those of musicians. NeuroSPECT during voluntary musical autoevocation demonstrated significant (>2 SD) increased activation of executive frontal cortex in Brodmann areas 9 and 10, secondary visual cortex (area 17), and paracingulate (areas 31 and 32). There was also activation in the para-executive frontal cortex (areas 45 and 46). In the basal ganglia there was activation in thalamus and lentiform nucleus. Deactivation below 2 SD was demonstrated by mean values in the cingulate gyrus, Brodmann areas 23 and 24, and subgenual area 25. Deactivation was also demonstrated when minimal values were analyzed in the same areas plus area 4 and areas 36 and 38, the latter in the pole of the temporal lobes. In three patients comparison of basal state with autoevocation demonstrated activation in executive frontal cortex (areas 8 and 9), para-executive cortex (area 45), primary auditory cortex (area 40), the right thalamus, and lentiform nucleus.

Spontaneous musical auditory perceptions in patients who develop abrupt bilateral sensorineural hearing loss. An uninhibition syndrome?

CONCLUSIONS: Spontaneous musical auditory perceptions commonly occur in patients who develop abrupt bilateral sensorineural hearing loss. The findings in both subjects who were image tested while having these perceptions are suggestive of a biological substrate for this process and of a central locus for auditory memory seemingly located in and around area 39 of Brodmann. When an individual has abrupt bilateral sensorineural hearing loss, stored musical memory can be released and this person can have musical perceptions without an external source. It is likely that an abrupt bilateral loss of inner ear function might uninhibit neuronal groups storing auditory memory. OBJECTIVES: The objectives of this study were as follows. (1) To determine if spontaneous musical auditory perceptions occur in patients who develop abrupt bilateral severe sensorineural hearing loss (not necessarily simultaneously). (2) To determine if there is a biological substrate to the process of recalling previous auditory perceptions. (3) To compare these findings with our normal databases of unstimulated and pure tone-stimulated volunteers. (4) To establish a hypothesis for the mechanisms of these occurrences. PATIENTS AND METHODS: Thirty two patients who had had abrupt bilateral severe sensorineural hearing loss (the interval between the losses of both ears could have been years) were contacted. They were asked if they had ever had the sensation of having musical auditory perceptions without external auditory stimuli. Two of these patients were image tested with single photon computerized emission tomography (neuroSPECT) while they were having these perceptions. RESULTS: All of the 32 subjects had musical auditory perceptions following their hearing loss in the second ear or when hearing loss in both ears occurred simultaneously. The two patients who were image tested with neuroSPECT had similar findings. There was a statistically significant increase in perfusion in area 39 of Brodmann, more intense on the right side, with increased perfusion also in both frontal lobes at the middle gyrus, with bilateral hypoperfusion in area 38 of Brodmann. These findings are similar to those observed in normal volunteers stimulated with pure tones.

Functional studies of the human auditory pathway after monaural stimulation with pure tones. Establishing a normal database.

CONCLUSIONS: Bilateral activation of Brodmann area 39 provides functional support for the concept of bilateral cortical activation with auditory stimulation. The observation that when Brodmann area 39 is activated, area 38 of the temporal lobe is simultaneously inhibited (a functional observation that has seemingly not been previously reported) supports the concept that inhibitory as well as excitatory relays play a role in the auditory pathways. In addition, this report helps to establish a functional database for future studies. OBJECTIVES: (i) To determine which areas of the cerebral cortex and basal ganglia are activated when the left and right ears are monaurally stimulated with pure tones, and what type of response (e.g. excitatory or inhibitory) occurs in these different areas. (ii) To determine the degree of ipsi- and/or contralateral cortical activation and/ or inhibition depending on the ear that is stimulated. (iii) To use this information as an initial step to develop a normal functional database for future studies. MATERIAL AND METHODS: A brain perfusion single-photon emission CT (SPECT) evaluation was conducted using auditory monaural stimulation with pure tones in 10 normal volunteers. Both ears were tested independently (20 examinations in total). 99mTc hexamethyl-propylenamine-oxime was injected while pure tones were delivered, and the SPECT imaging was done 1 h later. RESULTS: After delivering pure tones there was bilateral cortical activation in Brodmann areas 39 and 40, regardless of which ear was stimulated. Despite marked hyperperfusion in both areas 39, a more intense response was seen on the left compared to the right side, although this was not statistically significant. There was also activation in the executive frontal cortex areas 9 and 10 as well as in the temporal Brodmann areas 21 and 22. Simultaneously, area 38 of the temporal lobe was deactivated. In the subcortical structures there was also marked activation in both thalami and deactivation of the caudate nuclei without lateralization.

Functional studies (NeuroSPECT) of the human auditory pathway after stimulating binaurally with pure tones.

CONCLUSIONS: Our observations support the concept of bilateral cortical activation with monaural and binaural auditory stimulation. The observation that most of the significantly activated areas were the same with monaural or binaural stimulation suggests that the differences in auditory perception with binaural stimulation are not due to the involvement of significantly different processing centers but, more likely, to the type of information that reaches these centers for processing. The observation that the degree of stimulation was less intense in binaural than in monaural stimulation supports the concept that a richer binaural auditory stimulation compared with monaural stimulation does not mean summation of stimuli but integration and better processing of the information. For normal bilateral hearing subjects, a monaural stimulus is an uncommon event and may thus explain the more intense response. The repeatability of the results for monaural and binaural stimulation with pure tones in the same subjects confirms the consistency of the testing method. OBJECTIVES: (1) To determine which areas of the cerebral cortex and basal ganglia are activated by binaural stimulation with pure tones (left and right ear simultaneously) and what type of response occurs (e.g. excitatory or inhibitory) in these different areas. (2) To determine the degree of ipsilateral and/or contralateral cortical activation and/or inhibition. (3) To compare the data with our previous reports of monaural stimulation using the same technique and the same subjects. (4) To evaluate the consistency of our testing method. METHODS: Brain perfusion single photon emission computed tomography (SPECT) evaluation was conducted using auditory binaural stimulation with pure tones in six normal volunteers. Both ears were stimulated simultaneously. Tc99m HMPAO was injected while pure tones were delivered and the SPECT imaging was done 1 h later. RESULTS: After delivering pure tones there was bilateral activation in Brodmann areas 7 (somatosensory association cortex), 9 and 10 (executive frontal areas), 17, 18, and 19 (associative visual cortex). There was also activation in temporal areas 21, 22 (auditory association areas), and parietal areas 39 and 40 (Wernicke). There was also marked activation in both thalami. These activated areas were the same as those in our previous reports with monaural stimulation in the same subjects. However, except for areas 17, 18, 23, 31, and 32 (which remained over 4 SD above the normal maximum), the degree of activation was less intense in binaural compared with monaural stimulation. Inhibition was also less intense in binaural stimulation.

Is there a difference in activation or in inhibition of cortical auditory centers depending on the ear that is stimulated?

CONCLUSIONS: 1.With auditory stimuli cortical activation of Brodmann's areas 39 and 40 and inhibition of area 38 is bilateral. Inhibitory and excitatory relays play a role in the auditory pathways. 2. A statistically significant increased activation on the left side in areas 39 and 40, regardless of the stimulated ear, is suggestive that pure tones are preferably processed in the left hemisphere. 3. The significant difference in central inhibition depending on which ear is stimulated is supportive of the idea of a leading ear. OBJECTIVES: The objectives were to determine cortical activation/inhibition, ipsi/contralateral in response to monaural stimulation with pure tones, and if the response differs for right/left ear stimulation. SUBJECTS AND METHODS: Tc99m-HMPAO brain perfusion SPECT was done during monaural stimulation with pure tones in 10 volunteers. Ears were tested independently. RESULTS: During auditory stimulation perfusion increased in both hemispheres in Brodmann's areas 39-40 and decreased in area 38,>2 SD above and below the normal mean respectively, in both hemispheres, regardless of which side was stimulated. A significantly more intense response was seen in left versus right in areas 39 and 40. In area 38 there was bilateral inhibition, significantly more intense in response to left than right ear stimulation.

Efectos del consumo de marihuana en escolares sobre funciones cerebrales demostrados mediante pruebas neuropsicológicas e imágenes de neuro-SPECT / Effects of marihuana consumption in school children on brain functions demonstrated by means of neuropsychological tests and neuro-SPECT imaging

Comparative study based on 565 adolescent school children coming from four schools in the metropolitan area of Santiago, Chile. All were interviewed in order to select a sample that was stratified for sex, class and condition of consumer or non-consumer. The variables of intellectual coefficient and socioeconomical level were maintained constant. With this selection we conformed two groups: 40 consumers exclusively of marihuana and 40 non-consumers. We compared the results obtained in both groups in the neuropsychological tests while the neuroSPECT studies of consumers were compared against a normal database for the same age group. The adolescent consumers of marihuana demonstrate less cognitive capacity related to the process of learning such as attention, concentration, ranking, viso-spatial integration, immediate retention and visual memory. The differences between both groups are statistically significant. The findings of neuroSPECT demonstrate subgenual hypoperfusion bilaterally, more marked on the left side, in area 25 of Brodmann. This area controls mood. There is also frontal bilateral hypoperfusion (area 10 and area 32 of Brodmann). Area 32 is pre-anterior cingulate gyrus. Also hypoperfusion of the anterior cingulate gyrus (area 24 of Brodmann) and hypoperfusion of area 36 of Brodmann that projects over the hippocampus. Students that were consumers exclusively of marihuana demonstrate coincident abnormal findings of neuroimages and neuropsychological tests in areas of the brain related with learning and also significant differences between consumers with non-consumers in the neuropsychological tests.

Estudio comparativo basado en 565 escolares adolescentes pertenecientes a cuatro colegios de Santiago, Chile. Fueron encuestados todos para seleccionar una muestra estratificada por sexo, curso y condición de consumidores o no consumidores, manteniendo constante las variables coeficiente intelectual y nivel socioeconómico. Se conforman dos grupos: 40 consumidores exclusivos de marihuana y 40 no consumidores. Se comparan los resultados obtenidos en ambos grupos en los Test Neuropsicológios y del NeuroSPECT de consumidores con una base de datos considerados normales para el mismo grupo etario. Los adolescentes consumidores de marihuana evidencian menores habilidades cognitivas asociadas al proceso de aprendizaje, tales como atención, concentración, jerarquización, integración visoespacial, retención inmediata y memoria visual. Las diferencias entre ambos grupos son estadísticamente significativas. Los hallazgos del NeuroSPECT muestran hipoperfusión subgenual bilateral, más marcada en el hemisferio izquierdo (área 25 de Brodmann), hipoperfusión frontal bilateral (areas 10 y 32 de Brodmann), hipoperfusión del gyrus cingulado anterior (área 24 de Brodmann) e hipoperfusión del área 36 de Brodmann que proyecta sobre el hipocampo. Los estudiantes consumidores exclusivamente de marihuana muestran compromiso coincidente en neuroimágenes y test neuropsicológicos en áreas del cerebro relacionadas con el aprendizaje y se diferencian significativamente de los no-consumidores en las pruebas neuropsicológicas.

CADASIL presenting with a movement disorder: a clinical study of a Chilean kindred.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary vascular disease that usually begins with migraine, followed by repeated strokes and progressive dementia. We describe an unusual clinical presentation of this condition in members of a Chilean family with an established NOTCH3 mutation. We report early clinical, neuropsychological, transcranial ultrasound, magnetic resonance imaging (MRI), cerebral blood flow, and skin biopsy findings on these patients. Of the patients, 2 presented with facial dystonia, 1 of whom had abnormal single photon emission computed tomography and transcranial ultrasound studies after normal brain MRI scans. Our report emphasizes that CADASIL must be considered in the study of patients with secondary dystonia.

Síndrome de déficit atencional del adulto: correlación de hallazgos clínico-imagenológicos a partir de la técnica de SPECT cerebral / NeuroSPECT evaluation in adult attention deficit hyperactivity disorder

Contexto del problema. El Síndrome de Déficit Atencional (SDA) del adulto es un trastorno de difícil diagnóstico y cuyo oportuno reconocimiento y tratamiento puede impactar significativamente la calidad de vida de quienes lo padecen. La ausencia de pruebas diagnósticas concluyentes justifica la utilización de técnicas de neuro-imagen cerebral funcional en la investigación dirigida a reconocer patrones neuro-funcionales de valor diagnóstico. Objetivo. Realizar una descripción de los hallazgos neuro-funcionales encontrados en una cohorte de 23 pacientes adultos con SDA en estado de reposo a partir de la técnica de neuro-SPECT. A partir de estos hallazgos se proponen patrones neuro-funcionales con significado diagnóstico. Método. Se estudió una muestra aleatoria de 23 adultos (hombres: 17; mujeres: 6) con diagnóstico clínico de SDA tratados en la práctica privada. La muestra fue estudiada a través de la técnica de SPECT cerebral, analizándose 58 áreas de Brodmann, regiones de interés (ROI), incluyendo corteza cerebral y estructuras sub-corticales. Resultados. En el análisis de perfusión máxima cortical destaca la hiper-perfusión bilateral de las áreas 9, 10, 17, 18, 22, 23, 24 y 31 de Brodmann. En el análisis de mínimos se aprecia hipo-perfusión en áreas 4,11, 12, 18, 19 y 36 bilateral y 20 a izquierda. Al evaluar los valores promedios se observa hipo-perfusión en el área 24 izquierda y 25 bilateral. A nivel de estructuras sub-corticales destaca una hiper-perfusión talámica bilateral. Conclusiones. Los resultados reportados por nuestro grupo apoyan el rol de estructuras que se encuentran fuera del córtex frontal en la patogenia del SDA; especialmente el área que comprende la intersección de los lóbulos temporo-occipital, así como regiones parietales. Se discute el valor clínico de la hiper-perfusión frontal media como parte de un “default mode” y las implicancias que esto tendría como modelo...

Clinical Problem Context. The Attention Deficit Syndrome (ADS) in the adult is a clinical entity of difficult diagnosis and with a rewarding improvement of quality of life when this entity is diagnosed and treated successfully. There is an absence of diagnostic tests and therefore there is full justification for research applications for Functional NeuroIMaging techniques in ADS. Objectives. We report functional imaging findings by means of HMPAO NeuroSPECT in a group of 23 adult SDA patients. These findings submit diagnostic Neuroimaging functional patterns that are characteristic of adult SDA. Method. We report results in a group of 23 adult patients (17 males and 6 females) with clinical diagnosis of SDA. Patients were subjected to NeuroSPECT imaging and 58 Brodmann areas ROIS were analyzed including cortex and subcortical structures. Results. Analisis of MAXIMAL perfusion within the Brodmann Area (2.5 percent higher pixel counts, expressed as percent of higher pixel in cortex or cerebellum, whichever was smaller) demonstrates bilateral focal hyperperfusión in areas 9,10, 17,18,22,23,24 and 31 of Brodmann. In the analysis of MINIMAL values (2.5 percent minimal values within the Brodmann area) there is bilateral focal hypoperfusion in areas 4,11,12,18,19, and 36 and area 20 left. MEAN uptake in these Broadmann areas was diminished in area 24 left and bilateral areas 25. In the subcortical structures there is bilateral thalamic hyperperfusión. Conclusions. Our results support the concept of the role of structures outside of the cerebral frontal cortex in the pathogenie of SDA. We refer to areas in the intersection of temporo-occipital lobes and also the parietal lobes. We analyzed the clinical weight of medial frontal hyperperfusión as part of the default mode, and the explanation that this model might have in the variance of neuropsychological performances observed in these patients...

Efectos del consumo de marihuana en funciones cognitivas en jóvenes adolescentes / Effects of consumption of marihuana on cognitive functions in young students

El presente estudio explora el efecto de la marihuana en una población de jóvenes adolescentes escolares, que sólo consumen esta droga ilícita y no otra, y que jamás han consultado a un especialista por problemas de adicción. Los resultados muestran el efecto del consumo habitual de marihuana en funciones cognitivas involucradas en el aprendizaje. Una vez identificados los sujetos, se realizan evaluaciones individuales de estudiantes consumidores y no consumidores de educación media de establecimientos de dependencia municipal, particular subvencionada y particular pagada del Area Metropolitana (Santiago de Chile). Se evidencian efectos nocivos sobre la memoria inmediata, atención-concentración y estrategias de ejecución en los consumidores, con diferencias estadísticamente significativas respecto al grupo control. Se constata mayor consumo relativo en colegios pertenecientes a sectores marginales y escasa o inexistente percepción de daño asociado al consumo de la droga, especialmente entre los consumidores habituales. Las niñas tienden a igualar los niveles de consumo de los varones.

This study evaluates the effects of marihuana in a population of 14 to 17 year old secondary school students, who consume exclusively this illegal drug, and who have never consulted a specialist for addiction problems. The results show the effects of habitual consumption of marihuana on cognitive functions involved in the learning process. Once the subjects have been identified, individual evaluations are performed on students who consume and who do not consume marihuana in public, subsidized public, and private schools of Santiago, Chile. Harmful effects are detected on immediate memory, attention-concentration and execution strategies in consumers, with statistically significant differences in comparison to the control group. Higher consumption is found in schools in poorer districts. There is impaired perception of harm associated with the consumption of the drug especially among habitual consumers. Girls tend to consume the same amount as boys.

Neuro – functional and endocrine findings in patients with post-traumatic stress disorder

The authors studied the neuro-functional findings demonstrated by SPECT in a group of 7 patients diagnosed with post traumatic stress disorder (PTSD) and their correlation with endocrinologic and clinical variables. Brain perfusion was assessed using SPECT Tc99m – ECD. The Davidson Trauma Scale (DTS) for post traumatic stress disorder and the abbreviated version of the Beck Depression Inventory (BDI) were used to corroborate clinical impressions. Endocrine measures included: T3, total T4, TSH and cortisol levels. Neuro-functional findings included abnormal radiopharmaceutical uptake in regions involved in the recovery of verbal memories and executive functions (frontal and pre-frontal cortex), and limbic system. No endocrine alterations affecting thyroid or cortisol levels were found. The broad distribution of neuro-functional abnormalities causes us to hypothesize a diffuse etiologic mechanism, possibly involving a dysfunction in the permeability of the blood-brain barrier due to an underlying inflammatory process.

[Williams syndrome: clinical, cytogenetical, neurophysiological and neuroanatomic study]. / Síndrome de Williams: estudio clínico, citogenético, neurofisiológico y neuroanatómico.

BACKGROUND: Williams syndrome (WS) is a genetically based disorder caused by deletion of elastin and contiguous genes on chromosome 7q11.23. This syndrome is characterized by multiorganic involvement with dysmorphic facial features and a distinctive cognitive profile. It is an interesting model for elucidation of relationships between brain, cognition and genes. Patients have a visual-spatial cognition impaired with relative strengths in social and language abilities. AIM: To report clinical, cytogenetic, neurophysiological and neuroanatomic features in 44 patients referred as WS. PATIENTS AND METHODS: Forty four patients, aged 2 to 17 years, with the clinical diagnosis of Williams syndrome were studied with fluorescence in situ hybridization (FISH). In three cases, electrophysiological and neuroimaging studies were performed. RESULT: The deletion was confirmed in 23 patients. In three patients with neurophysiological studies, event related potentials suggested a cognitive difficulty in detecting and processing visual stimuli. Magnetic resonance imaging showed normal brain morphology. SPECT showed hypoperfusion of the right frontal lobe and bilateral anterior cingulum hyperperfusion. CONCLUSIONS: There are functional alterations in the brains of patients with Williams, which may be related to the cognitive deficits.

Alteraciones neuro-funcionales y neuro-endocrinas en una cohorte de pacientes que cursan con trastorno por estrés post traumático / Neuroendocrine and neurofunctional alterations in patient with post traumatic stress disorder

El trastorno por estrés post traumático (TEPT) se perfila en la actualidad como una patología emergente debido a las condiciones de vida modernas cada vez más exigentes y al énfasis epidemiológico y en salud mental por pesquisar las consecuencias de traumas cotidianos, como de aquellos derivados de conflictos bélicos o de la acción de fuerzas de seguridad y orden ciudadanos. Se describe que aproximadamente un 8 por ciento de quienes sufren un trauma experimentarán un cuadro clínico compatible con TEPT. Sin embargo, la larga duración y frecuente cronicidad de estos casos demanda un enorme esfuerzo al equipo de salud y costos elevados a los organismos que acogen a estos pacientes. El presente trabajo tiene por objetivo realizar un estudio neuro-funcional, clínico y de laboratorio en una muestra de 7 pacientes que cursan con un cuadro compatible con TEPT. Método: Se evaluó clínicamente a 7 pacientes que cursaban con TEPT, aplicándoseles una escala de evaluación para esta patología (Escala de Davidson) y el inventario de depresión de Beck. Se obtuvieron muestras de sangre con el objeto de evaluar los niveles de cortisol plasmático y hormonas tiroideas T3, T4 y TSH. Finalmente, los sujetos fueron evaluados a partir de la técnica de neuro SPECT delineándose una serie de Regiones e Interés (ROI) involucradas en la neurobiología del TEPT. Resultados: Se reportan para todos los pacientes de la cohorte estudiada valores elevados en escala Davidson para TEPT y en la escala de Beck para depresión (91.85 y 25.28 respectivamente). Se describen valores promedios normales de cortisol plasmático y de hormonas tiroideas T3, T4 y TSH (17.35 ug/dl, 1.34 ng/ml, 6,98 ug/dl y 2,95 uUI/ml respectivamente). Destaca la presencia de hiper-cortisolemia en tres de los pacientes estudiados. Los hallazgos neuro-funcionales se caracterizan por una hiper-perfusión a nivel de córtex fronto-parietal e hipo-perfusión...

Post Traumatic Stress Disorder (PTSD) is one of the most important emergent pathologies in mental health and is usually associated with current post modern´s life styles and with specific traumatic event such as belic conflicts or incident involving criminal behaviors affecting civilians. It is well known that 8% of victims of a traumatic event will develop PTSD. Furthermore, the chronicity and social impairment associated to this clinical entity requires an enormous effort from mental health’s professionals and huge costs to the systems involved in the rehabilitation of these patients. The aim of this study is to evaluate a sample of 7 patients affected from PTSD in order to understand their clinical characteristics, neuro-functional features and possible neuro-endocrine abnormatilies. Method: 7 patient affected with PTSD were clinically evaluated and submitted to a specific-validated post traumatic scale (Davidson scale) and also to a depression inventory (Beck depression inventory). Then, blood samples were taken in order to assess Neuro- endocrine levels of cortisol in plasma and T3, T4 and TSH levels. Finally, the subjects were studied by means of SPECT, delineating specific Region of Interest (ROI) involved in the neurobiological basis of PTSD. Results: we report on, for the entire sample, high scores on both scales used (Davidson scale: 91.85; Beck inventory: 25.28). These results confirm the previously reported high comorbidity between this two clinical entities. We describe average normal values for plasmatic cortisol levels and thyroid hormones levels T3, T4, TSH (17.35 ug/dl, 1.34 ng/ml, 6.98 ug/dl and 2.95 uUI/ml respectively). It is important to remark the presence of hypercortisolemia in 3 of the patients studied. Neuro-functional features were characterized by a cortical fronto-parietal hyper-perfusion and hypo-perfusion on limbic areas. This results were consistently replicated in the entire sample...

NeuroSPECT de la penumbra isquémica en infarto cerebral agudo y pronóstico de recuperabilidad / NeuroSPECT of the ischemic penumbra in acute brain infarct and viability prognosis

El infarto cerebral agudo representa una emergencia clínica, potencialmente reversible si se trata con trombolisis durante las primeras 3 a 6 horas de evolución. La reversibilidad del cuadro clínico es función, entre otros factores, del grado de profundidad de la hipoperfusión en la región cerebral comprometida. Otros factores que inciden en la reversibilidad del cuadro clínico es el tiempo transcurrido desde el inicio de la sintomatología antes del tratamiento y la recanalización del vaso obstruido. Presentamos dos casos de infarto cerebral embólicos que fueron estudiados con SPECT Cerebral y tratados con trombolisis cerebral durante las primeras 3 horas de evolución. El primer caso se trataba de una cardioembolía en “T” con oclusión de la carótida interna distal y de las arterias cerebral anterior y media proximales izquierdas y el segundo caso es de una cardioembolía con oclusión de la arteria cerebral media derecha desde su origen. La evolución de ambos casos fue diametralmente diferente y analizamos en este trabajo los resultados de la cuantificación de la hipoperfusión en la zona infartada con objeto de definir factores pronósticos de estos pacientes y la indicación de trombolisis arterial.

Bipolar disorder complicated by selfmutilation: neurofunctional changes demonstrated by Tc99mHMPAO Neuro SPECT

We report neurofunctional changes in patients with selfmutilation and bipolar disorder. We compared a sample of 29 patients with selfmutilation and bipolar disorder with a group of 20 patients with bipolar disorder without selfmutilation. Furthermore we had an additional control of 22 patients with Major Depression without selfmutilation. Among the findings in selfmutilation, increased anterior dorsal-ventral thalamic perfusion stands out, this is associated with decreased perfusion in the perilimbic area (areas 24, 32 and 23 of Brodmann). There are multiple reports relating in animals and humans selfmutilation with hypoalgesia, anesthesia and disestesias; an hypothesis can be formulated relating self mutilation phenomena with a dysfunction of thalamus and perilimbic circuits associated with nosoceptive circuits and somato-psychic conscience.