Association between gait speed deterioration and EEG abnormalities.

Physical and cognitive decline at an older age is preceded by changes that accumulate over time until they become clinically evident difficulties. These changes, frequently overlooked by patients and health professionals, may respond better than fully established conditions to strategies designed to prevent disabilities and dependence in later life. The objective of this study was twofold; to provide further support for the need to screen for early functional changes in older adults and to look for an early association between decline in mobility and cognition. A cross-sectional cohort study was conducted on 95 active functionally independent community-dwelling older adults in Havana, Cuba. We measured their gait speed at the usual pace and the cognitive status using the MMSE. A value of 0.8 m/s was used as the cut-off point to decide whether they presented a decline in gait speed. A quantitative analysis of their EEG at rest was also performed to look for an associated subclinical decline in brain function. Results show that 70% of the sample had a gait speed deterioration (i.e., lower than 0.8 m/s), of which 80% also had an abnormal EEG frequency composition for their age. While there was no statistically significant difference in the MMSE score between participants with a gait speed above and below the selected cut-off, individuals with MMSE scores below 25 also had a gait speed<0.8 m/s and an abnormal EEG frequency composition. Our results provide further evidence of early decline in older adults-even if still independent and active-and point to the need for clinical pathways that incorporate screening and early intervention targeted at early deterioration to prolong the years of functional life in older age.

Conocimientos y prácticas de los médicos cubanos respecto a Enterobacterales resistentes a carbapenémicos / Knowledge and practice on carbapenem-resistant Enterobacterales in medical doctors from a tertiary hospital in Cuba

Introducción: En el contexto de la pandemia de COVID-19, la infección por Enterobacterales resistentes a carbapenémicos productores de carbapenemasas (ERC-PC) se convierte en un problema de salud pública desafiante a nivel mundial. Los médicos desempeñan un papel fundamental en el manejo clínico de las infecciones por patógenos resistentes a carbapenémicos a nivel hospitalario y por ende en el control de estas. Sin embargo, no existen estudios sobre el conocimiento y prácticas de estos sobre ERC-PC en Cuba. Objetivo: Abordar conocimientos y prácticas sobre las infecciones por ERC-PC, su manejo terapéutico, prevención y control en médicos cubanos en un hospital terciario. Métodos: Se realizó un estudio observacional (descriptivo, de corte transversal) y se aplicó un cuestionario específico elaborado a 70 médicos asistenciales. Resultados: Hubo variabilidad en las opiniones sobre las ERC-PC y un conocimiento medio sobre estas en la mayoría de los encuestados. El 58,6 % de los médicos tenía experiencia en el manejo clínico de la infección por ERC-PC. Las brechas de conocimiento encontradas estuvieron asociadas a la escasa experiencia práctica en el manejo de casos. Hubo diferencia estadísticamente significativa en el nivel de conocimientos sobre los ERC-PC en los médicos con experiencia en el manejo de los ERC-PC en comparación con los médicos sin experiencia (p = 0,039). Conclusiones: Es necesario establecer un plan de formación continua en la temática para mejorar el desempeño de los profesionales de la salud en el control de las infecciones por ERC-PC y en el uso optimizado de los antibióticos.

Introduction: In the context of COVID-19 pandemic, carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE) infection becomes a global public health threat. Medical doctors play a fundamental role in the clinical management and control of infections caused by carbapenem-resistant pathogens. However, in Cuba there are not previous studies on the knowledge and practice of medical doctors about CR-CRE. Objective: To study the knowledge and practice of Cuban medical doctors in a tertiary hospital about CR-CRE infections, their clinical management, prevention and control. Methods: It was conducted an observational study (descriptive, cross-sectional) and an specific questionnaire to 70 medical doctors was applied. Results: There was variability on the opinions about CP-CRE and average knowledge in the majority of the respondents. 58.6% of the medical doctors had some experience in the clinical management of CP-CRE infections. Knowledge gaps were associated with the limited practical experience in the management of cases. There was statistically significant difference in the level of knowledge about CP-CRE of medical doctors with experience in the management of CP-CRE compared to inexperienced medical doctors (p = 0.039). Conclusions: It is necessary to establish a continuous training plan on this topic to improve the performance of health professionals in the control of CP-CRE infections and in the appropriate use of antibiotics.

Utilidad del monitoreo continuo del electroencefalograma en el paciente crítico / Utility of continuous electroencephalogram monitoring in the critical patients

Introducción: El monitoreo continuo del Electroencefalograma, es la recogida simultánea de la actividad cerebral y la conducta clínica por un período de horas a días. Por el alto costo de la técnica aún no está muy difundida. Objetivos: Evaluar la utilidad del monitoreo electroencefalográfico continuo en el paciente crítico. Métodos: Se realizó un estudio descriptivo, retrospectivo y longitudinal en 118 sujetos mayores de 19 años ingresados en las unidades de terapia del Hospital Clínico Quirúrgico Hermanos Ameijeiras; entre noviembre 2016 a octubre 2018 con indicación de un Electroencefalograma continuo. Se consideraron variables clínicas y electroencefalográficas: escala de Glasgow, ocurrencia de crisis, diagnóstico, estado al egreso, anormalidad del Electroencefalograma, descargas epileptiformes, sospecha de estatus epiléptico no convulsivo por electroencefalograma entre otras. Los datos se procesaron con test de Chi cuadrado, test de Mc Nemar y test t de student, se empleó un nivel de significación de p≤0.05. Resultados: 60 de los pacientes pertenecían al sexo femenino, la mediana de las edades fue 67,5 años. La escala de Glasgow mostró asociación significativa con el grado de anormalidad del electroencefalograma (p=0,001), es la arreactividad y la discontinuidad de la actividad de base predictores de pobre pronóstico. Se observaron descargas epileptiformes periódicas en 100 pacientes. Se definió estatus epiléptico no convulsivo en 56 sujetos (37,28 por ciento) y en 81 sujetos (68,64 por ciento) el resultado del electroencefalograma motivó una conducta médica. Conclusiones: El monitoreo continuo del electroencefalograma es útil en el diagnóstico y manejo del paciente con episodios no convulsivos, permite formular un pronóstico neurológico y orientó la conducta médica(AU)

Introduction: The continuous monitoring of the electroencephalogram is the simultaneous collection of brain activity and clinical behavior for a period of hours to days. Due to the high cost of the technique, it is not yet widely used. Objectives: To evaluate the usefulness of continuous electroencephalographic monitoring in critically ill patients. Methods: A descriptive, retrospective and longitudinal study was carried out in 118 subjects over 19 years of age admitted to the therapy units at Hermanos Ameijeiras Surgical Clinical Hospital; from November 2016 to October 2018. They were indicated a continuous electroencephalogram. Clinical and electroencephalographic variables were considered, such as Glasgow scale, seizure occurrence, diagnosis, discharge status, electroencephalogram abnormality, epileptiform discharges, suspicion of nonconvulsive status epilepticus by electroencephalogram, among others. The data was processed with the Chi square test, the Mc Nemar test and the student's t test, using significance level of p≤0.05. Results: Sixty patients were female, the median age was 67.5 years. The Glasgow scale showed significant association with the degree of electroencephalogram abnormality (p=0.001). A reactivity and discontinuity of baseline activity are predictors of poor prognosis. Periodic epileptiform discharges were observed in 100 patients. Non-convulsive status epilepticus was defined in 56 subjects (37.28 percent) and in 81 subjects (68.64 percent) the result of the electroencephalogram motivated a medical procedure. Conclusions: The continuous monitoring of the electroencephalogram is useful in the diagnosis and management of patients with non-convulsive episodes, it allows formulating a neurological prognosis and guided medical conduct(AU)

Nonconvulsive epileptic seizure monitoring with incremental learning.

Nonconvulsive epileptic seizures (NCSz) and nonconvulsive status epilepticus (NCSE) are two neurological entities associated with increment in morbidity and mortality in critically ill patients. In a previous work, we introduced a method which accurately detected NCSz in EEG data (referred here as 'Batch method'). However, this approach was less effective when the EEG features identified at the beginning of the recording changed over time. Such pattern drift is an issue that causes failures of automated seizure detection methods. This paper presents a support vector machine (SVM)-based incremental learning method for NCSz detection that for the first time addresses the seizure evolution in EEG records from patients with epileptic disorders and from ICU having NCSz. To implement the incremental learning SVM, three methodologies are tested. These approaches differ in the way they reduce the set of potentially available support vectors that are used to build the decision function of the classifier. To evaluate the suitability of the three incremental learning approaches proposed here for NCSz detection, first, a comparative study between the three methods is performed. Secondly, the incremental learning approach with the best performance is compared with the Batch method and three other batch methods from the literature. From this comparison, the incremental learning method based on maximum relevance minimum redundancy (MRMR_IL) obtained the best results. MRMR_IL method proved to be an effective tool for NCSz detection in a real-time setting, achieving sensitivity and accuracy values above 99%.

Características de los cuidadores principales de niños y adolescentes con fibrosis quística / Characteristics of main caregivers of children and adolescents with cystic fibrosis

Introducción: Las investigaciones sobre los cuidadores han tomado importancia por los efectos negativos que provoca en las esferas físicas, psicológicas y sociales de estas personas, debido a su dedicación prolongada a la atención de enfermos cuyas dolencias les impiden totalmente su autocuidado. Objetivos: Referir las características de los cuidadores principales de pacientes pediátricos con fibrosis quística. Métodos: Estudio descriptivo de corte transversal realizado en el segundo semestre del 2016, con 54 cuidadoras principales de pacientes menores de 19 años, atendidos en los hospitales Pediátrico de Centro Habana, Juan Manuel Márquez, de Marianao, y el William Soler, de Boyeros. Resultados: Las cuidadoras son mujeres, madres en su mayoría, sin vínculo laboral, con nivel educativo medio superior, dedicadas al cuidado de los enfermos a tiempo completo, lo que interfiere su vida personal y social. Ante estas situaciones responden con mediana capacidad de afrontamiento y adaptación ante las situaciones que les generan estrés. Conclusiones: Las estrategias de afrontamiento utilizadas por las cuidadoras están afectadas pues no generan respuestas efectivas que les permita adaptarse y responder a las situaciones de forma óptima, por lo que se requiere reforzar los recursos que están utilizando. La meta de enfermería como ciencia y como disciplina es un factor muy importante para obtener esos recursos necesarios para mejorar la calidad de vida de los niños, adolescentes y sus cuidadores(AU)

Introduction: Research on caregivers has become important because of the negative effects this activity causes in the physical, psychological and social aspects of these people due to their prolonged dedication to the care of patients, whose illnesses prevent them from fully looking for themselves. Objective: To describe the characteristics of the main caregivers of pediatric patients with cystic fibrosis. Methods: A cross-sectional descriptive study conducted in the second semester of 2016, with 54 main caregivers of patients under 19 years old that were attended in Centro Habana Pediatric Hospital, Juan Manuel Márquez (Marianao´s municipality Pediatric Hospital), and William Soler (Boyeros municipality´s Pediatric Hospital). Results: Caregivers are women, mostly mothers, with no employment, with a medium superior level of education, who are devoted to caring for the sick patients full-time, and this interferes with their personal and social life. Given these situations, they respond with a medium capacity for coping and adapting to situations that generate stress. Conclusions: Coping strategies used by caregivers are affected because they do not generate effective responses that allow them to adapt and respond to situations in an optimal way, so it is necessary to reinforce the resources they are using. The goal of nursing as a science and as a discipline is a very important factor in obtaining those necessary resources to improve the quality of life of children, adolescents and their caregivers(AU)

Características de los cuidadores principales de niños y adolescentes con fibrosis quística / Characteristics of main caregivers of children and adolescents with cystic fibrosis

Introducción: Las investigaciones sobre los cuidadores han tomado importancia por los efectos negativos que provoca en las esferas físicas, psicológicas y sociales de estas personas, debido a su dedicación prolongada a la atención de enfermos cuyas dolencias les impiden totalmente su autocuidado. Objetivos: Referir las características de los cuidadores principales de pacientes pediátricos con fibrosis quística. Métodos: Estudio descriptivo de corte transversal realizado en el segundo semestre del 2016, con 54 cuidadoras principales de pacientes menores de 19 años, atendidos en los hospitales Pediátrico de Centro Habana, Juan Manuel Márquez, de Marianao, y el William Soler, de Boyeros. Resultados: Las cuidadoras son mujeres, madres en su mayoría, sin vínculo laboral, con nivel educativo medio superior, dedicadas al cuidado de los enfermos a tiempo completo, lo que interfiere su vida personal y social. Ante estas situaciones responden con mediana capacidad de afrontamiento y adaptación ante las situaciones que les generan estrés. Conclusiones: Las estrategias de afrontamiento utilizadas por las cuidadoras están afectadas pues no generan respuestas efectivas que les permita adaptarse y responder a las situaciones de forma óptima, por lo que se requiere reforzar los recursos que están utilizando. La meta de enfermería como ciencia y como disciplina es un factor muy importante para obtener esos recursos necesarios para mejorar la calidad de vida de los niños, adolescentes y sus cuidadores(AU)

Introduction: Research on caregivers has become important because of the negative effects this activity causes in the physical, psychological and social aspects of these people due to their prolonged dedication to the care of patients, whose illnesses prevent them from fully looking for themselves. Objective: To describe the characteristics of the main caregivers of pediatric patients with cystic fibrosis. Methods: A cross-sectional descriptive study conducted in the second semester of 2016, with 54 main caregivers of patients under 19 years old that were attended in Centro Habana Pediatric Hospital, Juan Manuel Márquez (Marianao´s municipality Pediatric Hospital), and William Soler (Boyeros municipality´s Pediatric Hospital). Results: Caregivers are women, mostly mothers, with no employment, with a medium superior level of education, who are devoted to caring for the sick patients full-time, and this interferes with their personal and social life. Given these situations, they respond with a medium capacity for coping and adapting to situations that generate stress. Conclusions: Coping strategies used by caregivers are affected because they do not generate effective responses that allow them to adapt and respond to situations in an optimal way, so it is necessary to reinforce the resources they are using. The goal of nursing as a science and as a discipline is a very important factor in obtaining those necessary resources to improve the quality of life of children, adolescents and their caregivers(AU)

Autonomic impairment of patients in coma with different Glasgow coma score assessed with heart rate variability.

PRIMARY OBJECTIVE: The objective of this study is to assess the functional state of the autonomic nervous system in healthy individuals and in individuals in coma using measures of heart rate variability (HRV) and to evaluate its efficiency in predicting mortality. DESIGN AND METHODS: Retrospective group comparison study of patients in coma classified into two subgroups, according to their Glasgow coma score, with a healthy control group. HRV indices were calculated from 7 min of artefact-free electrocardiograms using the Hilbert-Huang method in the spectral range 0.02-0.6 Hz. A special procedure was applied to avoid confounding factors. Stepwise multiple regression logistic analysis (SMLRA) and ROC analysis evaluated predictions. RESULTS: Progressive reduction of HRV was confirmed and was associated with deepening of coma and a mortality score model that included three spectral HRV indices of absolute power values of very low, low and very high frequency bands (0.4-0.6 Hz). The SMLRA model showed sensitivity of 95.65%, specificity of 95.83%, positive predictive value of 95.65%, and overall efficiency of 95.74%. CONCLUSIONS: HRV is a reliable method to assess the integrity of the neural control of the caudal brainstem centres on the hearts of patients in coma and to predict patient mortality.

Nonconvulsive Epileptic Seizure Detection in Scalp EEG Using Multiway Data Analysis.

Nonconvulsive status epilepticus is a condition where the patient is exposed to abnormally prolonged epileptic seizures without evident physical symptoms. Since these continuous seizures may cause permanent brain damage, it constitutes a medical emergency. This paper proposes a method to detect nonconvulsive seizures for a further nonconvulsive status epilepticus diagnosis. To differentiate between the normal and seizure electroencephalogram (EEG), a K-Nearest Neighbor, a Radial Basis Support Vector Machine, and a Linear Discriminant Analysis classifier are used. The classifier features are obtained from the Canonical Polyadic Decomposition (CPD) and Block Term Decomposition of the EEG data represented as third order tensor. To expand the EEG into a tensor, Wavelet or Hilbert-Huang transform are used. The algorithm is tested on a scalp EEG database of 139 seizures of different duration. The experimental results suggest that a Hilbert-Huang tensor representation and the CPD analysis provide the most suitable framework for nonconvulsive seizure detection. The Radial Basis Support Vector Machine classifier shows the best performance with sensitivity, specificity, and accuracy values over 98%. A rough comparison with other methods proposed in the literature shows the superior performance of the proposed method for nonconvulsive epileptic seizure detection.

Diagnóstico precoz y proceso de atención en enfermería en pacientes pediátricos con fibrosis quística / Early diagnosis and nursing process of care in pediatric patients with cystic fibrosis

Introducción. La fibrosis quística (FQ) o mucoviscidosis, considerada una enfermedad extraña, hoy día se diagnostica a un número creciente de niños en todo el mundo y la cantidad de niños aquejados de esta enfermedad que llegan a la adolescencia y a la adultez es cada vez mayor. Objetivos. Facilitar aspectos importantes que tener en cuenta por parte del personal de enfermería en la detección precoz de la fibrosis quística y desarrollar un Plan de Cuidados de Enfermería estandarizado con los diagnósticos más frecuentes en estos pacientes. Método. Revisión bibliográfica. Se utilizaron bases de datos como EBSCO, SciELO y Medline bajo descriptores como «enfermería », «cuidadores» y «fibrosis quística». Conclusiones. El diagnostico precoz es fundamental para lograr una mejor calidad de vida y disminuir la mortalidad y el Proceso de Atención de Enfermería (PAE) se encarga de identificar los problemas reales y potenciales, siendo el documento guía que utiliza el personal de enfermería para trabajar las expectativas que cada paciente ha de lograr. En el nuevo PAE confeccionado se formularon 11 diagnósticos de enfermería, 11 expectativas y 63 acciones, que solucionan total o parcialmente los problemas y necesidades de estos pacientes (AU)

Introduction. An increasing amount of children worldwide are currently diagnosed with cystic fibrosis (CF), or mucoviscidosis, still considered a rare disease. The number of children suffering from this disease reaching adolescence and adulthood is likewise increasing. Objectives. To present important aspects to be considered by nursing staff in the early detection of cystic fibrosis and develop a standarized Nursing Care Plan for these patients’ most common diagnoses. Method. Literature review using databases such as EBSCO, SciELO and Medline using searching keawords including nursing, caregivers and cystic fibrosis. Conclusions. Early diagnosis is crucial to achieve a better life quality and reduce mortality. Nursing Care Plan (NCP) is responsible for identifying actual and potential problems and is the guiding document used by the nursing staff to work out the achievement of each patient’s expected evolution. The resulting new NCP developed included 11 nursing diagnoses, 11 expected evolutions and 63 actions that fully and / or partially address patients’ problems and needs (AU)

Ictal-interictal continuum: A proposed treatment algorithm.

The ictal-interictal continuum (IIC) is characterized by periodic and/or rhythmic EEG patterns that occur with relative high frequency in critically ill patients. Several studies have reported that some patterns seen within the continuum are independently associated with poor outcome. However there is no consensus regarding when to treat them or how aggressive treatment should be. In this review we examine peer-reviewed original scientific articles, guidelines and reviews indexed in PubMed and summarize current knowledge related to the ictal-interictal continuum. A treatment algorithm to guide management of critically ill patients with EEG patterns that fall along the IIC is proposed. The algorithm-based on best current practice in adults-takes into account associated clinical events, risk factors for developing seizures, response to medication trials and biomarkers of neuronal injury.

Nivel de conocimientos sobre salud bucal en los trabajadores del Semi-Internado Carlos Manuel de Céspedes de Bayamo, 2014-2015 / Level of knowledge in regards to oral health in workers from the Semi Internal School Carlos Manuel de Cespedes in Bayamo. 2014-2015

Introducción: la salud es un punto de encuentro, ahí confluyen lo biológico y lo social, el individuo y la comunidad, la política social y la economía. Objetivo: elevar el nivel de conocimiento sobre salud bucal en los trabajadores del Semi-Internado Carlos Manuel de Céspedes, curso 2014-2015, en el municipio Bayamo, provincia Granma. Método: se realizó un estudio experimental de intervención con pre-prueba y pos-prueba, el universo estuvo constituido por el total de personas de la escuela, a la que pertenecen los 106 trabajadores y todos formaron parte del estudio. Resultados: la aplicación de la intervención educativa demostró ser un instrumento práctico para modificar el nivel de conocimiento y se elevó el nivel de conocimiento de los trabajadores sobre salud bucal. Conclusiones: el nivel de conocimiento, antes de emplear la intervención fue evaluado de mal, el grupo de edad más afectado fue el de 60 años, en cuanto al sexo no se encontraron diferencias, las necesidades de aprendizaje se identificaron mediante las respuestas incorrectas de la encuesta de conocimientos(AU)

Introduction: health is a meeting point, were some factors converge: the biological and the social, the individual and the community, the social policy and the economics. Objective: to increase the level of knowledge on oral health in workers of the Semi-Internal school Carlos Manuel de Cespedes, during the course 2014-2015, in the municipality of Bayamo, Granma province. Method: it was performed an experimental intervention study with pre-test and post-test, the universe consisted of the amount of people in the school, including the 106 workers and they were all part of the study. Results: the application of the educational intervention proved to be a practical tool to change the level of knowledge and this level increased in regards to the oral health. Conclusions: the level of knowledge, before using the intervention was evaluated as bad, the most affected age group was the one of 60, there were no differences in regards to sex, and the learning needs were identified through the incorrect responses of the knowledge survey(EU)

Absence of face-specific cortical activity in the complete absence of awareness: converging evidence from functional magnetic resonance imaging and event-related potentials.

In this study, we explored the neural correlates of perceptual awareness during a masked face detection task. To assess awareness more precisely than in previous studies, participants employed a 4-point scale to rate subjective visibility. An event-related fMRI and a high-density ERP study were carried out. Imaging data showed that conscious face detection was linked to activation of fusiform and occipital face areas. Frontal and parietal regions, including the pre-SMA, inferior frontal sulcus, anterior insula/frontal operculum, and intraparietal sulcus, also responded strongly when faces were consciously perceived. In contrast, no brain area showed face-selective activity when participants reported no impression of a face. ERP results showed that conscious face detection was associated with enhanced N170 and also with the presence of a second negativity around 300 msec and a slow positivity around 415 msec. Again, face-related activity was absent when faces were not consciously perceived. We suggest that, under conditions of backward masking, ventral stream and fronto-parietal regions show similar, strong links of face-related activity to conscious perception and stress the importance of a detailed assessment of awareness to examine activity related to unseen stimulus events.

Therapeutic effect of the combined use of growth hormone releasing peptide-6 and epidermal growth factor in an axonopathy model.

Amyotrophic lateral sclerosis (ALS) is a disease of the central nervous system characterized by loss of spinal motor neurons, for which no effective treatment exists. Epidermal growth factor (EGF) and growth hormone releasing peptide-6 (GHRP-6) have been considered as good candidates for the treatment of this disease, due to their well documented effects in eliciting pleiotrophic and cell survival mechanisms. The aim of the present work was to evaluate the separate and combined effects of both peptides in an experimental animal model of ALS, the proximal axonopathy induced by 1,2 diacetylbenzene (1,2 DAB) in mice. The evaluations were conducted by means of behavioral tests (trapeze, tail suspension, gait pattern, and open field) and by recording the complex muscle action potential (CMAP) in three different hind limb segments: proximal S1, medial S2, and distal S3. Intraperitoneal daily administration of 1,2 DAB produced significant reduction in body weight, muscle strength, extensor reflex, spontaneous activity, and changes in gait pattern parameters. In parallel 1,2 DAB produced significant prolongation of onset latency and decrease in amplitude of CMAP and in the integrated complex action potential index. Daily administration of the separate compounds did not accelerate the recovery of the affected parameters, except for the gait pattern. The combined treatment produced significant improvement in behavioral parameters, as well as in electrophysiological recovery, particularly in the proximal segment of CMAP. The latter results confirm the proximal character of 1,2 DAB neuropathy, and suggest that combined therapy with EGF and GHRP-6 might be a good therapeutic strategy for the treatment of ALS.

Hematological, biochemical, respiratory, cardiovascular and electroneurophysiological parameters in African green monkeys (Cercopithecus aethiops sabaeus). Its use in non-clinical toxicological studies.

BACKGROUND: The purpose of this study is to better characterize the hematological, biochemical, respiratory, cardiovascular and electroneurophysiological parameters in young adult Cercopithecus aethiops sabaeus of both sexes. The rhesus and cynomolgus monkeys are widely used as experimental primate models. However, only few articles have been published testing toxicological effects of pharmaceuticals on African green monkey. METHODS: The present study was carried out with the recompilation of all parameters recorded before the first drug administration in five sub-chronic or chronic toxicological studies performed on 66 Cercopithecus aethiops sabaeus, born in Cuba. RESULTS: This study provides hematological, biochemical, respiratory, cardiovascular and electroneurophysiological data for both choosing animals to be included into experiments and monitoring these parameters during the study. CONCLUSIONS: We conclude that this study provides valuable integrated data for determining the health status, including electroneurophysiological parameters, data not previously reported for this species, of the African green monkey.

Systemic and skin toxicity in Cercopithecus aethiops sabaeus monkeys treated during 26 weeks with a high intravenous dose of the anti- epidermal growth factor receptor monoclonal antibody Nimotuzumab.

Nimotuzumab (h-R3) is a humanized anti-epidermal growth factor receptor monoclonal antibody (mAb) registered for treating head and neck tumours. The present study was designed to evaluate the systemic and skin toxicity of chronic intravenous administration of the h-R3 in a relevant species demonstrated by comparing the h-R3 binding affinity constants (Kd) in microsomal placental fractions from Homo sapiens and Cercopithecus aethiops monkeys using an EGF-Receptor radioligand competition assay. The Kd obtained for Nimotuzumab were 9.1 x 10(-8) M for monkeys and 4.5 x 10(-8) M for humans. Monkeys (n = 18) were distributed into 3 groups with 3 animals of each sex in each group. Group I received saline; group II received 2.85 mg/kg of h-R3; and group III received 28.57 mg/kg of the h-R3, which represent 1 and 10 times the human dose, and they were weekly intravenously treated during 26 weeks. During the study there were no deaths. Electroneurophysiological, sanguine chemistry and haematological results did not evidence alterations. Areas of haematomas, probably related with the administration procedure, were observed at the administration zones of all animals. The electrocardiography study showed at the end of the study a slight increase in the cardiac frequency of four treated animals without other signs. Unexpectedly, skin biopsies and a detailed clinical inspection of the animals did not detect the presence of cutaneous rash or any other skin toxicity sign reported for the majority of the anti-EGF-R monoclonal antibodies. It is concluded that doses up to 28.5 mg/kg of h-R3, intravenously administered during 26 weeks to Cercopithecus aethiops monkeys, do not produce considerable toxic effects.

Attention to surfaces modulates motion processing in extrastriate area MT.

In the visual system, early atomized representations are grouped into higher-level entities through processes of perceptual organization. Here we present neurophysiological evidence that a representation of a simple object, a surface defined by color and motion, can be the unit of attentional selection at an early stage of visual processing. Monkeys were cued by the color of a fixation spot to attend to one of two transparent random-dot surfaces, one red and one green, which occupied the same region of space. Motion of the attended surface drove neurons in the middle temporal (MT) visual area more strongly than physically identical motion of the non-attended surface, even though both occurred within the spotlight of attention. Surface-based effects of attention persisted even without differential surface coloring, but attentional modulation was stronger with color. These results show that attention can select surface representations to modulate visual processing as early as cortical area MT.

Sensory suppression during shifts of attention between surfaces in transparent motion.

During transparent motion, attention to changes in the direction of one illusory surface will impede recognition of a similar event affecting the other surface if both are close together in time. This is a form of object-based attentional blink (AB). Here, we show that this AB is related to a smaller N200 response to the change in direction and that the response is even smaller for trials on which the subject makes mistakes compared to those with correct responses consistent with signal detection theory models. The variation of N200 associated with the AB can be modeled by an attenuation of current sources estimated in visual extrastriate cortex. These results suggest that the AB in the transparent motion paradigm is due to the suppression of sensory signals in early visual areas.

Two-object attentional interference depends on attentional set.

In this study, we explored the influence of an irrelevant translational event on the automatic capture of attention to one of two superimposed surfaces defined by transparent motion. The results showed that an irrelevant translation on one surface did not automatically capture the subjects' attention if the attentional resources have been endogenously allocated on the other surface. Moreover, the reduction in the motion-onset component of the event-related potential observed in trials where the irrelevant event affected the uncued surface supports the existence of a top-down control of early sensorial processing in this paradigm. This study provides further evidence of the interaction of stimulus-driven and goal-directed mechanisms in the control of visual attention.

Dividing attention between form and motion during transparent surface perception.

Attending to objects implies the concurrent process of features that are analyzed in different visual subsystems or domains. Previous works have shown that attention cannot be simultaneously directed to the components of motion present in two transparent surfaces [M. Valdés et al., Cognition 66 (1998) B13-B23], even though they occupy overlapping regions of space. In this paper, possible across-domain effects in object-based attention were examined using a conjunction of form and motion in transparent superimposed surfaces. After directing attention to one surface, different combinations of motion and form judgements were performed. If both attributes belonged to the same surface, no interference was found. If the two judgements concerned features from different surfaces, a large performance cost was present for the attribute belonging to the uncued surface. The fact that these effects cut across feature domains supports the integrated competition hypothesis [J. Duncan, Attention and Performance XVI, The MIT Press, 1996, pp. 549-578].