Toxic effects of inhaled manganese on the olfactory bulb: an ultrastructural approach in mice.

Olfactory dysfunction is a common symptom reported by patients with neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Despite the knowledge gathered about the pathology of these diseases, little information has been generated regarding the ultrastructure modifications of the granule cells that regulate the information for odor identification. Swollen organelles and nuclear invaginations identified the exposed mice. Necrosis was evidenced at 4th week of exposure, whereas apoptosis arose at 8th week of exposure. A ruffled electron-dense membrane changes were also found. The changes observed could be explained by the reactive oxygen species generated by manganese and its effects on the membrane's structure and on the cytoskeleton's function. This study contributes to correlate metal air pollution and neurodegenerative changes with olfactory affection.

[Development of an automatic discrimination system for glaucomatous visual fields based on neuro-fuzzy nets]. / Desarrollo de un sistema automático de discriminación del campo visual glaucomatoso basado en un clasificador neuro-fuzzy.

PURPOSE: To provide a useful tool in the diagnosis of glaucoma by developing an automatic system for visual field classification based on neuro-fuzzy rules. METHOD: A total of 212 visual fields (OCTOPUS 123 program G1X), from 198 patients, were analysed: 61 normal (controls) and 151 with glaucomatous damage (49% with incipient damage, 29.1% with moderate damage, and 21.9% advanced). Inclusion criteria for glaucomatous patients were: Visual acuity >0.5, IOP < 20 mm Hg (with treatment), refraction <5 Dp and previous perimetric experience. EXCLUSION CRITERIA: miotics, other ocular pathologies which could interfere with visual field examination, and for control subjects: visual acuity >0.5, no ocular pathologies and refraction < 5 Dp. A neuro-fuzzy classifier (NEFCLASS) is a system consisting in a series of fuzzy rules, obtained after a learning process, which attempts to assign to each piece of data input its corresponding output. Initially, the characteristics of each data input are established (input units). Then, based on previous knowledge, a set of rules are defined, and finally, the learning process allows the optimisation of the classifier parameters to generate an output. RESULTS: Input units were defined by using the mean defects calculated at specific areas of the visual field; five rules were then created which generated sensitivity and specificity values of 96.0% and 93.4% respectively. CONCLUSIONS: The use of neuro-fuzzy rules for visual field classification in normal vs glaucomatous can provide results which can match the quality of those obtained with other techniques such as discriminatory analysis or neural networks.

Desarrollo de un sistema automático de discriminación del campo visual glaucomatoso basado en un clasificador neuro-fuzzy / Development of an automatic discrimination system for glaucomatous visual fields based on neuro-fuzzy nets

Objetivo: Construir un sistema automático de clasificación del campo visual (CV), basado en reglas fuzzy, como herramienta de ayuda al diagnóstico de glaucoma. Método: Se analizaron 212 perimetrías blanco-blanco (OCTUPUS 123 programa G1X) correspondientes a 61 controles y 151 glaucomatosos (incipientes 49,0 por ciento, moderados 29,1 por ciento y avanzados 21,9 por ciento) de 198 pacientes. Criterios de inclusión (glaucomatosos): Agudeza visual >0,5, PIO 0,5 sin patología ocular salvo defectos de refracción (refracción (5D). Un clasificador neuro-fuzzy (NEFCLASS) es un sistema formado por un conjunto de reglas fuzzy, obtenidas a partir de un proceso de aprendizaje, que pretende asignar a una entrada dada la clase de salida correspondiente. Inicialmente, se seleccionan las características de entrada, seguidamente, se construye una base de reglas a partir del conocimiento a priori existente y, finalmente, la etapa de aprendizaje, permite optimizar los parámetros del clasificador. Resultados: Utilizando como características de entrada los defectos medios, calculados en áreas específicas del CV, se obtuvieron cinco reglas que arrojaron unos valores de sensibilidad y especificidad del 96,0 por ciento y 93,4 por ciento, respectivamente. Conclusiones: La aplicación de técnicas neuro-fuzzy en la discriminación de campos visuales normales y glaucomatosos ofrece resultados muy competitivos frente a técnicas ya utilizadas en esta tarea (análisis discriminante y redes neuronales) (AU)

Purpose: To provide a useful tool in the diagnosis of glaucoma by developing an automatic system for visual field classification based on neuro-fuzzy rules. Method: A total of 212 visual fields (OCTOPUS 123 program G1X), from 198 patients, were analysed: 61 normal (controls) and 151 with glaucomatous damage (49% with incipient damage, 29.1% with moderate damage, and 21.9% advanced). Inclusion criteria for glaucomatous patients were: Visual acuity >0.5, IOP < 20 mm Hg (with treatment), refraction <5 Dp and previous perimetric experience. Exclusion criteria: miotics, other ocular pathologies which could interfere with visual field examination, and for control subjects: visual acuity >0.5, no ocular pathologies and refraction < 5 Dp. A neuro-fuzzy classifier (NEFCLASS) is a system consisting in a series of fuzzy rules, obtained after a learning process, which attempts to assign to each piece of data input its corresponding output. Initially, the characteristics of each data input are established (input units). Then, based on previous knowledge, a set of rules are defined, and finally, the learning process allows the optimisation of the classifier parameters to generate an output. Results: Input units were defined by using the mean defects calculated at specific areas of the visual field; five rules were then created which generated sensitivity and specificity values of 96.0% and 93.4% respectively. Conclusions: The use of neuro-fuzzy rules for visual field classification in normal vs glaucomatous can provide results which can match the quality of those obtained with other techniques such as discriminatory analysis or neural networks (Arch Soc Esp Oftalmol 2002; 77: 669-676) (AU)

Effects of reinforcement rate and delay on the acquisition of lever pressing by rats.

The acquisition of lever pressing by naive rats, in the absence of shaping, was studied as a function of different rates and unsignaled delays of reinforcement. Groups of 3 rats were each exposed to tandem schedules that differed in either the first or the second component. First-component schedules were either continuous reinforcement or random-interval 15, 30, 60 or 120 s; second-component schedules were fixed-time 0, 1, 3, 6, 12, or 24 s. Rate of responding was low under continuous immediate reinforcement and higher under random-interval 15 s. Random interval 30-s and 60-s schedules produced lower rates that were similar to each other. Random-interval 120 s controlled the lowest rate in the immediate-reinforcement condition. Adding a constant 12-s delay to each of the first-component schedule parameters controlled lower response rates that did not vary systematically with reinforcement rate. The continuous and random-interval 60-s schedules of immediate reinforcement controlled higher global and first-component response rates than did the same schedules combined with longer delays, and first-component rates showed some graded effects of delay duration. In addition, the same schedules controlled higher second-component response rates in combination with a 1-s delay than in combination with longer delays. These results were related to those from previous studies on acquisition with delayed reinforcement as well as to those from similar reinforcement procedures used during steady-state responding.

[Treatment of esophageal stenosis with Savary-Gilliard balloons in children]. / Tratamiento con las bujias de Savary-Gilliard en las estenosis esofagicas del niño.

30 patients (less than 15 years old) were admitted for esophageal strictures, 16 of them secondary to corrosive injury. All the patients were treated with endoscopic dilation with Savary Gilliard bougie. The dilatation were done with general anesthesia using an Olympus GIF-XP10 endoscope and with fluoroscopic control. In the esophageal stenosis secondary to caustic ingestion endoscopic injection with Betamethasone was also used. The most frequent site of the stenosis was the upper third of the esophagus, and the main type of stenosis was tubular in the secondary to caustic burns and annular in the other group. In the posteaustic group 385 dilatations were performed in 115 sessions. Two perforations and one sepsis were reported in patients with corrosive stenosis. There was no mortality. 43.7% of the patients with corrosive stenosis and 85.7% with stenosis secondary to other causes obtained complete healing. Oesophageal dilatation with Savary-Gilliary bougies represents a safe and reliable method for the treatment of esophageal strictures.