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In this investigation, we make use of the indeterminate Likert scale to analyze the results of a survey applied to legal professionals in the province of Tulcán, Ecuador, on the incidence of the Administrative Organic Code in the current legal system. With the use of this scale, we sought the possibility that the surveyed professionals would express their degree of acceptance, indetermination, and non-acceptance of this code. The results we obtained showed positive levels of acceptance, especially among public employees of the Decentralized Autonomous Governments, but also significant values of indetermination or neutrality.

Com o objetivo de discutir as interferências sobre as questões etnico-raciais no contexto da América Latina e os desdobramentos para os processos de (in)exclusão da população afrodescendente, a partir dos relatórios e documentos dos organismos internacionais, realizou-se estudo bibliográfico e documental. As discussões foram articuladas com Munanga (2015), Goes e Silva (2013), Sousa, (2009), Gentili (2001) e Barreto (2009), além de outros. A partir do estudo é possível perceber que, apesar de conquistar a liberdade, no contexto da América Latina, a população afrodescendente ainda sofre com as mazelas históricas que negam e invisibilizam a cultura e os aspectos históricos que provocaram tal exclusão. Nos documentos dos Organismos Internacionais encontram-se informações que ora denunciam as situações de (in)exclusão presentes na América Latina e ora fazem indicações/recomendações para desencadear pretensas ações visando os processos inclusivos dos afrodescendentes, porém alinhadas aos interesses do capitalismo.

Introduction: The brain is an extraordinarily dynamic structure specially its physiology in response to pathological events. This response include several mechanisms such as changes in cell metabolism, genes expression and possible modifications in cell phenotype and in connectivity that reflect activation of processes like neurogenesis, neuritogenesis and synaptogenesis. Several aspects related with neuroplasticity has been proposed as part of the pathophysiological bases to understand brain ischemia and its exofocal phenomena. Progress in understanding of the pathophysiology of brain lesion has required the use of experimental models to evaluate cellular events that occur immediately after the lesion or later, to associate this changes with clinical observations and to propose pharmacological neuroprotection therapies.Objective: The purpose of the present work is to compile the advances in understanding of plasticity after brain lesion, mainly related with exofocal areas to a core lesion.Discussion and conclusions: The present work shows recent advances in neuroplasticity based on experimental approaches, and preclinical findings related with the exofocal ischemic phenomena: changes in areas not completely ischemic, changes in no ischemic areas affected by chemical or electrical signals, changes in the pattern of connectivity and adaptative changes in remote areas to the ischemic core. Finally, we discuss clinical aspects associated with this changes, experimental strategies and clinical pharmacological interventions. [ABSTRACT FROM AUTHOR]

This paper presents the zero-inflated generalised Poisson distribution, which is useful when there is a large presence of zeros in the sample. After presenting the model, we develop a specific program based on Mathematica, overcoming some limitations of alternative approaches such as STATA or EViews, which do not include the zero-inflated Poisson distribution among its routines. The advantages of the model used and the proposed program are illustrated with a real example that is very appropriate to its features, namely an analysis of the factors influencing university students’ attendance at tutoring sessions. This example is particularly suitable to show the usefulness of the methodology presented because it includes a large number of zeros, reflecting the many occasions on which the students do not attend these sessions. The students’ place of residence, their attendance at lectures and the application of continual assessment are variables that seem to account for attendance at tutoring sessions.

En este trabajo se describe un procedimiento de evaluación continua realizado en la asignatura de Matemáticas I en el presente curso académico 2002-2003, para las titulaciones Licenciatura en Economía (LE), Licenciatura en Administración y Dirección de Empresas (LADE) y Diplomatura en Ciencias Empresariales (DCE) de la Facultad de Ciencia Económicas y Empresariales de la Universidad de Las Palmas de Gran Canaria (ULPGC). Analizamos la evolución de los alumnos al incorporar este sistema así como su incidencia en los resultados obtenidos en el examen final.

En este trabajo se describe la experiencia de cambio de examen en la asignatura de Matemáticas I (del primer cuatrimestre del primer curso) de las titulaciones Licenciatura en Economía, Licenciatura en Administración. y Dirección. de Empresas y Diplomatura en Ciencias Empresariales, llevada a cabo durante el presente curso académico. Esencialmente, el cambio consistió en sustituir un 60% de la puntuación del examen por un cuestionario tipo test, el resto quedaba formado por un problema y un ejercicio para ser resuelto con la ayuda del ordenador (que ya se realizaban en cursos anteriores). Este trabajo examina, en primer lugar, la homogeneidad entre las distintas versiones del test que por razones logísticas fue necesario realizar. A continuación realiza un estudio desglosado de los resultados obtenidos en las diferentes titulaciones y los resultados del cuestionario por bloques temáticos.

La evaluación es el último principio instruccional que cierra el proceso enseñanza/aprendizaje. Si teóricamente la evaluación contrasta las intenciones con los resultados, orientando la toma de decisiones; en la práctica, compara los objetivos propuestos con los resultados del aprendizaje obtenidos en el proceso enseñanza/aprendizaje a partir del contraste con unos criterios preestablecidos, y procede a la toma de decisiones sobre la superación o no de la materia. La evaluación ha de ser programada eligiendo los métodos adecuados y definiendo su temporalización. Cualquier método de evaluación debe ser válido, en el sentido que mida aquello que queremos; debe ser fiable, esto es, que permita un cierto grado de confianza en los resultados obtenidos, y justo, es decir que exista concordancia entre las enseñanzas y lo que se exige. No existe un método de evaluación universalmente válido, la elección depende de los objetivos planteados y de los contenidos. Pueden combinarse varios procedimientos, por ejemplo, pruebas orales o escritas con cuestiones teóricas o teórico-prácticas cortas, con preguntas abiertas de respuesta larga, teóricas o prácticas, y trabajos extensos de carácter práctico individuales o de grupo.

Background: Biotechnological processes for efficient resource recovery from residual materials rely on complex conversions carried out by reactor microbiomes. Chain elongation microbiomes produce valuable medium-chain carboxylates (MCC) that can be used as biobased starting materials in the chemical, agriculture and food industry. In this study, sunflower oil is used as an application-compatible solvent to accumulate microbially produced MCC during extractive lactate-based chain elongation. The MCC-enriched solvent is harvested as a potential novel product for direct application without further MCC purification, e.g., direct use for animal nutrition. Sunflower oil biocompatibility, in situ extraction performance and effects on chain elongation were evaluated in batch and continuous experiments. Microbial community composition and dynamics of continuous experiments were analyzed based on 16S rRNA gene sequencing data. Potential applications of MCC-enriched solvents along with future research directions are discussed., Results: Sunflower oil showed high MCC extraction specificity and similar biocompatibility to oleyl alcohol in batch extractive fermentation of lactate and food waste. Continuous chain elongation microbiomes produced the MCC n-caproate (nC6) and n-caprylate (nC8) from L-lactate and acetate at pH 5.0 standing high undissociated n-caproic acid concentrations (3 g L -1 ). Extractive chain elongation with sunflower oil relieved apparent toxicity of MCC and production rates and selectivities reached maximum values of 5.16 ± 0.41 g nC6 L -1 d -1 (MCC: 11.5 g COD L -1 d -1 ) and 84 ± 5% (e - eq MCC per e - eq products), respectively. MCC were selectively enriched in sunflower oil to concentrations up to 72 g nC6 L -1 and 3 g nC8 L -1 , equivalent to 8.3 wt% in MCC-enriched sunflower oil. Fermentation at pH 7.0 produced propionate and n-butyrate instead of MCC. Sunflower oil showed stable linoleic and oleic acids composition during extractive chain elongation regardless of pH conditions. Reactor microbiomes showed reduced diversity at pH 5.0 with MCC production linked to Caproiciproducens co-occurring with Clostridium tyrobutyricum, Clostridium luticellarii and Lactobacillus species. Abundant taxa at pH 7.0 were Anaerotignum, Lachnospiraceae and Sporoanaerobacter., Conclusions: Sunflower oil is a suitable biobased solvent to selectively concentrate MCC. Extractive reactor microbiomes produced MCC with improved selectivity and production rate, while downstream processing complexity was reduced. Potential applications of MCC-enriched solvents may include feed, food and biofuels purposes., (© 2021. The Author(s).)

Medium-chain carboxylates (MCC) derived from biomass biorefining are attractive biochemicals to uncouple the production of a wide array of products from the use of non-renewable sources. Biological conversion of biomass-derived lactate during secondary fermentation can be steered to produce a variety of MCC through chain elongation. We explored the effects of zero-valent iron nanoparticles (nZVI) and lactate enantiomers on substrate consumption, product formation and microbiome composition in batch lactate-based chain elongation. In abiotic tests, nZVI supported chemical hydrolysis of lactate oligomers present in concentrated lactic acid. In fermentation experiments, nZVI created favorable conditions for either chain-elongating or propionate-producing microbiomes in a dose-dependent manner. Improved lactate conversion rates and n-caproate production were promoted at 0.5-2 g nZVI⋅L -1 while propionate formation became relevant at ≥ 3.5 g nZVI⋅L -1 . Even-chain carboxylates (n-butyrate) were produced when using enantiopure and racemic lactate with lactate conversion rates increased in nZVI presence (1 g⋅L -1 ). Consumption of hydrogen and carbon dioxide was observed late in the incubations and correlated with acetate formation or substrate conversion to elongated products in the presence of nZVI. Lactate racemization was observed during chain elongation while isomerization to D-lactate was detected during propionate formation. Clostridium luticellarii , Caproiciproducens , and Ruminococcaceae related species were associated with n-valerate and n-caproate production while propionate was likely produced through the acrylate pathway by Clostridium novyi . The enrichment of different potential n-butyrate producers ( Clostridium tyrobutyricum , Lachnospiraceae , Oscillibacter , Sedimentibacter ) was affected by nZVI presence and concentrations. Possible theories and mechanisms underlying the effects of nZVI on substrate conversion and microbiome composition are discussed. An outlook is provided to integrate (bio)electrochemical systems to recycle (n)ZVI and provide an alternative reducing power agent as durable control method., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Contreras-Dávila, Esveld, Buisman and Strik.)

The production of biochemicals from renewables through biorefinery processes is important to reduce the anthropogenic impact on the environment. Chain elongation processes based on microbiomes have been successfully developed to produce medium-chain fatty acids (MCFA) from organic waste streams. Yet, the sustainability of chain elongation can still be improved by reducing the use of electron donors and additional chemicals. This work aimed to couple lactate production and subsequent chain elongation to decrease chemicals input such as electron donors and hydroxide for pH control in repeated-batch food waste fermentation. Food waste with adjusted pH was used as substrate and fermentation proceeded without pH control. During fermentation, lactate was first formed through the homolactic pathway and then converted to fatty acids (FA), mainly n-butyrate and n-caproate. The highest n-caproate carbon selectivities (mmol C/mmol C FA ) and production rates were 38% and 4.2 g COD/L-d, respectively. Hydroxide input was reduced over time to a minimum of 0.47 mol OH - /mol MCFA or 0.79 mol OH - /kg COD FA . Lactate was a key electron donor for chain elongation and its conversion was observed at pH as low as 4.3. The microbiome enriched in this work was dominated by Lactobacillus spp. and Caproiciproducens spp. The high abundance of Caproiciproducens spp. and their co-occurrence with Lactobacillus spp. suggest Caproiciproducens spp. used lactate as electron donor for chain elongation. This work shows the production of n-caproate from food waste with decreased use of hydroxide and no use of exogenous electron donors., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The scope of this paper was to analyze the trends, impact on life expectancy and effect of the main associated socioeconomic factors with the death rate by homicide in Colombia between 2000 and 2014 at the state level, by gender and age groups. Standardized mortality rates and years of life lost among those under 85 years of age were calculated and multivariate regression analysis was performed using negative binomial fixed effects regression models with panel data to analyze the associated socioeconomic factors with the incidence of homicide. The reduction of the death rate by homicide in Colombia was corroborated, which was generalized at state level, though it did not occur homogenously. A higher mortality risk was found among males, particularly between 15 and 49 years of age. Economic growth and inequality were negatively associated with death rates by homicide; unemployment was positively associated; and poverty had no effect on the mortality rate. Investigating the main associated factors with homicidal violence is complex, but is indispensable due to its impact on economic and social development, given that it mainly affects the population of productive age, with broad public health consequences and at a high cost to healthcare services.

Introduction: A high proportion of depressive disorders are accompanied by anxious manifestations, just as depression and anxiety often present with many painful manifestations, or conversely, painful manifestations cause or worsen depressive and anxious expressions. There is increasingly more evidence of the pathophysiological, and neurophysiological and technical imaging similarity of pain and depression., Methods: Narrative review of the pathophysiological and clinical aspects of depression and chronic pain comorbidity. Research articles are included that emphasise the most relevant elements related to understanding the pathophysiology of both manifestations., Results: The pathological origin, physiology and clinical approach to these disorders have been more clearly established with the latest advances in biochemical and cellular techniques, as well as the advent of imaging technologies. This information is systematised with comprehensive images and clinical pictures., Conclusions: The recognition that the polymorphism of inflammation-related genes generates susceptibility to depressive manifestations and may modify the response to antidepressant treatments establishes that the inflammatory response is not only an aetiopathogenic component of pain, but also of stress and depression. Likewise, the similarity in approach with images corroborates not only the structural, but the functional and pathophysiological analogy between depression and chronic pain. Knowledge of depression-anxiety-chronic pain comorbidity is essential in the search for effective therapeutic interventions., (Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.)

Derangements of microvascular blood flow distribution might contribute to disturbing O 2 extraction by peripheral tissues. We evaluated the dynamic relationships between the mesenteric O 2 extraction ratio ([Formula: see text]) and the heterogeneity of microvascular blood flow at the gut and sublingual mucosa during the development and resuscitation of septic shock in a swine model of fecal peritonitis. Jejunal-villi and sublingual microcirculation were evaluated using a portable intravital-microscopy technique. Simultaneously, we obtained arterial, mixed-venous, and mesenteric blood gases, and jejunal-tonometric measurements. During resuscitation, pigs were randomly allocated to a fixed dose of dobutamine (5 µg·kg -1 ·min -1 ) or placebo while three sham models with identical monitoring served as controls. At the time of shock, we observed a significant decreased proportion of perfused intestinal-villi (villi-PPV) and sublingual percentage of perfused small vessels (SL-PPV), paralleling an increase in [Formula: see text] in both dobutamine and placebo groups. After starting resuscitation, villi-PPV and SL-PPV significantly increased in the dobutamine group with subsequent improvement of functional capillary density, whereas [Formula: see text] exhibited a corresponding significant decrease (repeated-measures ANOVA, P = 0.02 and P = 0.04 for time × group interactions and intergroup differences for villi-PPV and [Formula: see text], respectively). Variations in villi-PPV were paralleled by variations in [Formula: see text] ( R 2  = 0.88, P < 0.001) and these, in turn, by mesenteric lactate changes ( R 2  = 0.86, P < 0.001). There were no significant differences in cardiac output and systemic O 2 delivery throughout the experiment. In conclusion, dynamic changes in microvascular blood flow heterogeneity at jejunal mucosa are closely related to the mesenteric O 2 extraction ratio, suggesting a crucial role for microvascular blood flow distribution on O 2 uptake during development and resuscitation from septic shock. NEW & NOTEWORTHY Our observations suggest that dynamic changes in the heterogeneity of microvascular blood flow at the gut mucosa are closely related to mesenteric O 2 extraction, thus supporting the role of decreasing functional capillary density and increased intercapillary distances on alterations of O 2 uptake during development and resuscitation from septic shock. Addition of a low-fixed dose of dobutamine might reverse such flow heterogeneity, improving microcirculatory flow distribution and tissue O 2 consumption., (Copyright © 2017 the American Physiological Society.)

Introduction: Suicides are one of the main public health issues globally. Objective: To analyze the trends and impact of suicide mortality in Colombia and México between 2000 and 2013, nationally, by sex and age groups. Materials and methods: Mortality vital statistics from the Colombian Departamento Administrativo Nacional de Estadística and the Mexican Instituto Nacional de Estadística y Geografía were used. We conducted a descriptive and cross sectional study for which we calculated standardized mortality rates and years of life lost in people between 0 and 100 years of age. Results: In Colombia, the suicide mortality rate decreased between 2000 and 2013 for both sexes (28% for men and 38% for women); an opposite trend was observed in México (with an increase of 34% for males and 67% for females). In 2013, the years of life lost in Colombia were 0,32 among men and 0,15 among women, with a decreasing trend since 2000, whereas in México a level of 0,42 was observed in men and 0,2 in women, with an increasing trend since 2000. The age groups where suicides had a bigger impact were those of men 15 to 49 years of age in both countries, while suicides were more uniformly distributed among women between 15 and 84 years of age., Conclusion:  Suicide mortality increased gradually in México, whereas in Colombia an opposite trend was observed. Suicides can be prevented, so it is fundamental to implement public health policies focused on timely identification, comprehensive prevention strategies and the study of associated risk factors.

Objective: To evaluate transcallosal changes after a local ischemic injury in rats by using the monoclonal marker anti-NeuN (Mouse anti-neuronal nuclei)., Methods: Twenty-eight adult, male, Wistar rats were subjected to focal injury in the right hemisphere. The technique used was the experimental model of focal ischemic injury through intraluminal suture of the middle cerebral artery. Analyses were made for the five groups: after the lesion (control), at 24 h, 96 h, 10 days and 20 days. Exofocal neuronal damage was inferred from neuronal immunoreactivity changes to NeuN., Results: In the cortex contralateral to the lesion, immunoreactivity was diminished. This finding was most notable in the supra-granular sheets 24 h post ischemia. After 96 h, there was a generalized diminishment of the inmmunoreactivity in the supra and infra-granular sheets. At 10 and 20 days, the tissue recovered some immunoreactivity to NeuN, but there were some changes in the VI layer., Conclusion: The immunoreactive changes to NeuN support the process of inter-hemispheric diaschisis. Changes in immunoreactivity could indicate metabolic stress secondary to the disruption in connectivity to the site of lesion.

Tumor Necrosis Factor-alpha (TNF-α) is an immunomodulatory and proinflammatory cytokine implicated in neuro-inflammation and neuronal damage in response to cerebral ischemia. The present study tested the hypothesis that anti-TNF-α agents may be protective against cerebral infarction. Transient focal ischemia was artificially induced in anesthetized adult male Wistar rats (300-350 g) by middle cerebral artery occlusion (MCAO) with an intraluminal suture. TNF-α function was interfered with either a chimeric monoclonal antibody against TNF-α (infliximab-7 mg/kg) aiming to TNF-α soluble and membrane-attached form; or a chimeric fusion protein of TNF-α receptor-2 with a fragment crystallizable (Fc) region of IgG1 (etanercept-5 mg/kg) aiming for the TNF-α soluble form. Both agents were administered intraperitoneally 0 or 6 h after inducing ischemia. Infarct volume was measured by 2,3,5-triphenyltetrazolium chloride staining. Cerebral infarct volume was significantly reduced in either etanercept or infliximab-treated group compared with non-treated MCAO rats 24 h after reperfusion. These results suggest that anti-TNF-α agents may reduce focal ischemic injury in rats.

The objective of this study was to calculate average years of life lost due to breast and cervical cancer in Mexico in 2000 and 2010. Data on mortality in women aged between 20 and 84 years was obtained from the National Institute for Statistics and Geography. Age-specific mortality rates and average years of life lost, which is an estimate of the number of years that a person would have lived if he or she had not died prematurely, were estimated for both diseases. Data was disaggregated into five-year age groups and socioeconomic status based on the 2010 marginalization index obtained from the National Population Council. A decrease in average years of life lost due to cervical cancer (37.4%) and an increase in average years of life lost due breast cancer (8.9%) was observed during the period studied. Average years of life lost due to cervical cancer was greater among women living in areas with a high marginalization index, while average years of life lost due to breast cancer was greater in women from areas with a low marginalization index.

Background: Extended-release (ER) paliperidone is an innovative atypical antipsychotic that allows minimal peak-to-through fluctuations with once-daily dosing., Objective: To evaluate effectiveness, safety and tolerability of flexible, once-daily doses of paliperidone ER (3-12 mg/day) in patients with schizophrenia from Argentina and Colombia who had previously failed treatment with other antipsychotic agents., Methods: The authors conducted a 6-month, open-label, prospective and multicentric study. Effectiveness was assessed with Positive and Negative Syndrome Scale (PANSS) and Personal and Social Performance scale (PSP). Other measures of effectiveness, safety and tolerability, were also conducted., Results: Paliperidone ER 3-12 mg/day improved Positive and Negative Syndrome Scale (PANSS) total scores (primary endpoint) from baseline to study end (p < 0,001). In the PANSS total score, the mean change from baseline (83, 9 units) to end point (53,7 units) was significant (p < 0,001). Flexible doses of paliperidone ER demonstrated a ≥20% reduction in the PANSS total score (p<0.001) in almost two-thirds of patients. PSP mean change from baseline (52 units) to end point (85 units) was significant (p < 0,001). Secondary effectiveness assessments, as well as safety and tolerability measures, demonstrated favourable results throughout the study., Conclusions: Flexible doses of paliperidone ER over 6 months were effective, safe and well tolerated in patients with schizophrenia from Argentina and Colombia., (Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.)

Introduction: The teaching of Psychiatry in Colombia is the result of the accumulation of different conceptual streams dating back to early twentieth century and the beginning of Psychiatric study. By a way of different teaching methods, this knowledge was transferred from generation to generation to materialize into its current formation., Methods: Different key moments are recognied in the history of Psychiatry throughout the world and the introduction of these trends in Colombia, and specifically its impact on teaching., Results: The current structure derives from French elemens of organ-dynamic Psychiatry, both conceptual and clinical, likewise, it is formed from conception kraepeliana and biologic therapies introduced from the second quarter of the last century and the psychoanalytic trend introduced since 1950., Conclusion: The Psychiatric Departments of Colombia form prominently in Pychiatry and are skillful in managing mental illness, with basic knowledge of pathophysiology and psychopathology, as well as good training in psychopharmacology and psychotherapy. A limitation is evident in the formation of community mental health., (Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.)

Background: Children with scorpion envenomation have massive sympathetic activation and variable degrees of left ventricular systolic dysfunction., Objective: To evaluate a rescue protocol for children with severe left ventricular dysfunction secondary to scorpion envenomation., Methods: Four children, after scorpion envenomation, were subjected to a rescue protocol for acute left ventricular dysfunction: Endotracheal intubation and respiratory assistance, electrocardiograms, chest x-Ray, echocardiograms and blood samples for norepinephrine and troponin I serum levels. Samples and echocardiograms were repeated at 12, 24 and 48 hours. Intravenous medications: Dobutamine: 4-6 microg/kg/min. Amiodarone: 3 mg/kg during a 2 hour period. Maintenance: 5 mg/kg/day. Furosemide: 0.5 mg/kg/dose. Diuretics were given when the systemic blood pressure was above percentile fifty. Amiodarone, Dobutamine and Furosemide were administered during the first 48 hours. Beta-adrenergic blockers and angiotensin converting enzyme were given, at 48 hours after admission, once the left ventricular Ejection fraction > 0.35 and the clinical status had improved., Results: On admission, norepinephrine was 1,727.50 +/-794.96 pg/ml, troponin I 24.53 +/- 14.09 ng/ml and left ventricular ejection fraction 0.20 +/- 0.056. At twelve hours, norepinephrine and troponin I serum levels were down to half of the initial values and the ejection fraction increased to 0.32 +/- 0.059. During the next 24 and 48 hours, the ejection fraction rose to 0.46 +/- 0.045, (p<0.01) and norepinephrine and troponin diminished to 526.75 +/- 273.73 (p < 0.02) and 2.20 +/- 2.36 (p<0.02) respectively., Conclusion: Amiodarone, by acting as a neuromodulator, is very likely responsible for the early and progressive decrease of serum norepinephrine.

Patients with chronic congestive heart failure have a sequential and incessant activation of those neurohormonal systems, which control body fluids, cardiac output and systemic blood pressure. Neurohormonal activation is initially selective and regional. Generalized activation is a late event in the natural history of congestive heart failure. Although the ultimate stimulus responsible for the activation of these neurohormonal systems is unknown, a decreased cardiac output and diminished effective blood volume have been proposed as the responsible mechanisms. However, extensive clinical and experimental research suggest that cardiac remodeling and loading of low-pressure cardiac receptors with sympathetic afferents could be the triggering events followed by unloading of high-pressure carotid receptors by decreased cardiac output and diminished effective blood volume.

After occlusion of the middle cerebral artery in rats, a robust neuronal loss occurs in the ipsilateral substantia nigra reticulata. In this study we have assessed whether degeneration of the substantia nigra is accompanied by changes in the expression of the anti-apoptotic protein Bcl-2. Neuronal loss was assessed by neuronal nuclei (NeuN) immunoreactivity. A significant decrease of Bcl-2 expression was observed in the substantia nigra 12, 24 and 72 h after middle cerebral artery occlusion. These results suggest that the secondary neuronal loss in the substantia nigra could be related with the modification of proteins regulating programmed cell death. Exo-focal cell death may explain the appearance of neuropsychiatric symptoms that are not correlated with the primary site of lesion.

Scorpion human envenoming is a public health hazard in the southwest of Venezuela. Tityus zulianus is one of the scorpion species whose venom causes lung edema and cardiac failure in children. These occasionally deadly manifestations have been attributed to a massive sympathetic discharge. The intraperitoneal administration of T. zulianus venom (20 micrograms/g mouse) to anesthetized mice during subcutaneous microdialysis caused increased secretions, dyspnea, seizures and death between 30 min to 2 h. Seven amino acids were analyzed by capillary electrophoresis with laser induced fluorescence detection (CE-LIFD) in the collected samples before and after the venom administration. We found an increase of arginine (39%), phenylalanine (40%) and glutamate (94%), with no changes in valine, serine and aspartate, changes were significant when the injection of venom and vehicle were compared and before vs after venom injection. Further investigation is needed to know if the observed changes could be related to the molecular mechanisms of the venom or some of its components and therefore with the envenoming symptoms. To our knowledge, this is the first report with subcutaneous microdialysis and CE-LIFD coupling in scorpion envenomation studies in vivo, in mice.

Microdialysis is a simple technique that allows monitoring endogenous or exogenous substances in any extracellular compartment. It has many useful experimental and clinical applications. The sampling of the extracellular fluid of the subcutaneous compartment is especially useful for metabolic evaluation in critically ill patients, pharmacokinetic studies and blood glucose monitoring. We built a subcutaneous microdialysis probe, with a cellulose hollow fiber (13,000 molecular weight cut off, 200 microns outside diameter) glued to stainless steel tubing (26 ga. outside diameter). It was implanted in the subcutaneous tissue of a critically ill child or anesthetized mice to obtain amino acids patterns by means of capillary electrophoresis with laser induced fluorescence detection (CE-LIFD). The probe was also implanted in ambulatory volunteers to monitor glucose. The results confirmed that subcutaneous microdialysis is a very simple, inexpensive and not aggressive method with advantages over repeated venipuncture sampling and endovenous microdialysis sampling. The present report shows that subcutaneous microdialysis with the proper analytical technique can be used to monitor the chemical composition of the interstitial compartment in very different preclinical or clinical conditions.

Superresolution is the process of extending the spectrum of a diffraction-limited image beyond the optical passband. We consider the neural-network approach to accomplish superresolution and present results on simulated gray-scale images degraded by diffraction blur and additive noise. Images are assumed to be sampled at the Nyquist rate, which requires spatial interpolation for avoiding aliasing, in addition to frequency-domain extrapolation. A novel, to our knowledge, use of vector quantization for the generation of training data sets is also presented. This is accomplished by training of a nonlinear vector quantizer, whose codebooks are subsequently used in the supervised training of the neural network with backpropagation.

Superresolution is the process by which the bandwidth of a diffraction-limited spectrum is extended beyond the optical passband. Many algorithms exist that are capable of superresolution; however, most are iterative methods, which are ill suited for real-time operation. One approach that has been virtually ignored is the neural-network approach. We consider the feedforward architecture known as a multilayer perceptron and present results on simulated binary images blurred by a diffraction-limited, circular-aperture optical transfer function and sampled at the Nyquist rate. To avoid aliasing, the network performs as a nonlinear spatial interpolator while simultaneously extrapolating in the frequency domain.

The autonomic nervous system is abnormal in patients with advanced Chagas'heart disease. Most researchers consider these autonomic abnormalities as primary, specific and irreversible. However, when and why do these abnormalities appear in the natural history of Chagas'disease, is still the subject of intense controversy. Recent morphological and functional studies strongly suggest that, the sympathetic and the parasympathetic abnormalities, are preceded by myocardial damage and left ventricular dysfunction. Consequently, the cardiac parasympathetic abnormalities and the activation of the sympathetic and of the renin-angiotensin-aldosterone systems of chagasic patients are very likely secondary and partially reversible. Therefore, neurohormonal activation, as postulated by the neurogenic theory could contribute to the progression of myocardial damage and left ventricular dysfunction. Additional clinical investigations are necessary to clarify this important issue.

Objectives: To know the clinical characteristics in the presentation of Buerger's disease in San Juan de Dios Hospital, Bogota, Colombia, between 1986 and 1996, and compare them with a previous series from the same Hospital and another reported in international literature; To determine the changes in the form of appearance of the disease., Methods: We reviewed the clinical information of 22 patients with diagnosis of Buerger's disease, observed between 1986 and 1993, and we added the information of the clinical histories of eight other patients with equal diagnosis, observed between 1994 and 1996 in our Unit., Results: We observed 30 patients: 28 men (93%) and two women (7%), with a ratio M:F of 14:1, with an average age of 39+10 years (range from 18 to 52 years). Sixty percent were younger than 40 years and only the 10% were older than 50 years. The most frequent reasons for consultation were: pain in rest in the affected extremity, gangrene and ulceration in more than 50%. Raynaud's phenomenon in 30%, and the related surgical history in 40%. The pedal pulse was the most compromised followed by popliteal, poster or tibial and femoral. We did not observe the presence of thrombophlebitis. Eighty percent showed compromise of more than one extremity. All of them were active smokers. Three patients showed IgG anticardiolipine antibodies at high level., Conclusions: The clinical characteristics are similar to those reported, we find also a reduction of the disease diagnosis. It calls to our attention that no thrombophlebitis was found in the present series and the less compromise of the upper extremities with a frequent femoral compromise. All this points toward a change in the natural history of the disease.

The autonomic nervous system is abnormal in patients with advanced Chagas' heart disease. Most researchers consider these autonomic abnormalities as primary, specific and irreversible. However, when and why these abnormalities appear in the natural history of Chagas' disease, is still the subject of intense controversy. Recent morphological and functional studies strongly suggest that the sympathetic and the parasympathetic abnormalities are preceded by myocardial damage and left ventricular dysfunction. Moreover, chagasic patients with cardiac failure benefit from drugs which antagonize neurohumoral activation. Consequently, the abnormalities of the autonomic nervous system of chagasic patients are very likely secondary and partially reversible.