Anatomy of corpus callosum in prenatally malnourished rats

The effect of prenatal malnutrition on the anatomy of the corpus callosum was assessed in adult rats (45-52 days old). In the prenatally malnourished animals we observed a significant reduction of the corpus callosum total area, partial areas, and perimeter, as compared with normal animals. In addition, the splenium of corpus callosum (posterior fifth) showed a significant decrease of fiber diameters in the myelinated fibers without changing density. There was also a significant decrease in diameter and a significant increase in density of unmyelinated fibers. Measurements of perimeter's fractal dimensions from sagittal sections of the brain and corpus callosum did not show significant differences between malnourished and control animals. These findings indicate that cortico-cortical connections are vulnerable to the prenatal malnutrition, and suggest this may affect interhemispheric conduction velocity, particulary in visual connections (splenium).

Retinal nerve fibre layer thickness measurements in normal Indian population by optical coherence tomography.

PURPOSE: To obtain retinal nerve fibre layer thickness measurements by optical coherence tomography (OCT) in normal Indian population. MATERIALS AND METHODS: Total of 118 randomly selected eyes of 118 normal Indian subjects of both sex and various age groups underwent retinal nerve fiber layer thickness analysis by Stratus OCT 3000 V 4.0.1. The results were evaluated and compared to determine the normal retinal nerve fiber layer thickness measurements and its variations with sex and age. RESULTS: Mean +/- standard deviation retinal nerve fiber layer thickness for various quadrants of superior, inferior, nasal, temporal and along the entire circumference around the optic nerve head were 138.2 +/- 21.74, 129.1 +/- 25.67, 85.71 +/- 21, 66.38 +/- 17.37 and 104.8 +/- 38.81 microm, respectively. There was no significant difference in the measurements between males and females and no significant correlation with respect to age. CONCLUSION: Our results provide the normal retinal nerve fiber layer thickness measurements and its variations with age and sex in Indian population.

Quantitative Analysis of Retinal Nerve Fiber Layer Thickness of Normal Children and Adolescents

PURPOSE: To determine the normal range of retinal nerve fiber layer (RNFL) thickness of normal children and adolescents by optical coherence tomography (OCT). METHODS: This study analyzed 144 eyes of 72 normal children and adolescents by OCTIII (Zeiss-Humphrey, San Leandro, CA., USA) and the results were compared with the RNFL thickness of Korean adults. RESULTS: The mean RNFL thickness of the 72 normal children and adolescents was 105.53+/-10.33 micrometer. The mean values for left and right eyes were 104.28+/-7.68 micrometer and 106.79+/-12.98 micrometer, respectively. There was no significant difference in mean RNFL thickness between the 4 quadrants of the left and right eyes (p=0.926). Additionally, the mean RNFL thickness showed a similar size pattern regardless of age (p=0.99). RNFL thickness was found to be greater in adults than in children or adolescents, although the difference was not statistically significant (p=0.295. Likewise, no significant difference was found with gender (p=0.822) or in the pattern of RNFL thickness of 12 sectors between children and adults (p=0.08). CONCLUSIONS: This study reports RNFL thickness, as determined by OCT, for normal children and adolescents. We found this measurement method to be suitable for the early diagnosis of glaucoma and to the examination of its progression in these subjects. The findings could be used as clinical parameters for adolescent glaucoma.

Asymmetry Analysis of the Retinal Nerve Fiber Layer Thickness in Normal Eyes using Optical Coherence Tomography

PURPOSE: To investigate the asymmetry of the retinal nerve fiber layer thickness (RNFLT) with respect to the horizontal and vertical meridian and between the right and left eye in normal subjects. METHODS: The RNFLT was measured in 121 normal volunteers by optical coherence tomography (OCT). The RNFLT was analyzed by dividing the circle scanning area (diameter 3.4 mm) around the optic disc into 4 quadrants and 12 sectors. RESULTS: There was a significant difference between the RNFLT of the nasal and temporal quadrant in individual eyes. There was a significant difference between the RNFLT of corresponding sectors with respect to the vertical or horizontal meridian in individual eyes. The nasal and temporal RNFLTs were asymmetrical between the right and left eye in the quadrant and sector analysis. The RNFLT of the nasal and temporal quadrant was thicker in the right eye. The nasal and inferior RNFLT measured by OCT had a significant correlation with degree of refractive error. CONCLUSIONS: In normal subjects without significant anisometropia, there was significant asymmetry of the RNFLT for each eye as well as between the right and left eye.

Retinal nerve fiber layer measurements in indian eyes using the scanning laser polarimeter, GDx.

PURPOSE: To obtain retinal nerve fiber layer (RNFL) measurements in normal Indian subjects of different age groups; and to determine the differences between the right and the left eye of a subject and variations between male and female gender using the scanning laser polarimeter GDx. MATERIALS AND METHODS: Prospective cross-sectional study of 180 eyes of 94 subjects. The RNFL values were obtained with the nerve fiber analyser GDx using default quadrant positions supplied by the manufacturer. Fourteen parameters were studied. Of these 6 were average-based parameters (average thickness, superior maximum, inferior maximum, ellipse average, superior average, inferior average), 4 ratio-based parameters (symmetry, superior ratio, inferior ratio, superior/nasal), 4 "other" parameters (maximum modulation, number, ellipse modulation, superior integral). The main outcome measures were effect of age on RNFL values, comparison of males and females and the right and the left eye of a subject. RESULTS: There was a negative linear correlation with age. Three ratio-based parameters showed a statistically significant negative correlation with age. "Number" increased with age. Superior maximum, superior average, superior integral, symmetry and superior ratio were higher for the left eye. 'Number' was higher for the right eye. Superior ratio and maximum modulation were more in females than males, no difference was noted with other parameters. CONCLUSION: There was a gradual decrease of RNFL values with increasing age - the superior quadrant values were higher for the left eye than the right eye, suggesting asymmetry. No significant differences were detected between males and females.

Padronização normal das fibras nervosas intraepidérmicas em 30 voluntários saudáveis com PGP 9, 5 / Normal pattern of intraepidermal nerve fibers in 30 healthy volunteers with PGP 9.5

O recente método de avaliação das fibras nervosas intraepidérmicas com o PGP 9,5 vem se mostrando de grande utilidade no diagnóstico das neuropatias sensitivas de fibras finas, autonômicas e neuropatias periféricas subclínicas. Devido à variação da técnica relatada na literatura é de fundamental importância uma padronização normal. Estudamos 15 homens e 15 mulheres com média de idade de 34,5 anos. Em todos os voluntários foi realizada biopsia de pele na porção distal da perna. A média da densidade linear das fibras nervosas intraepidérmicas foi 5,3/mm com mediana de 6,0 e desvio padrão de 1,94. Essa técnica possui um grande número de vantagens em relação à biopsia de nervo convencional, é simples, pouco invasiva, reproduzível e pode ser repetida no mesmo paciente para avaliar progressão da neuropatia e possíveis respostas terapêuticas.

Watery and dark axons in Wallerian degeneration of the opossum's optic nerve: different patterns of cytoskeletal breakdown?

In this paper we report a qualitative morphological analysis of Wallerian degeneration in a marsupial. Right optic nerves of opossums Didelphis marsupialis were crushed with a fine forceps and after 24, 48, 72, 96 and 168 hours the animals were anaesthetized and perfused with fixative. The optic nerves were immersed in fixative and processed for routine transmission electron microscopy. Among the early alterations typical of axonal degeneration, we observed nerve fibers with focal degeneration of the axoplasmic cytoskeleton, watery degeneration and dark degeneration, the latter being prevalent at 168 hours after crush. Our results point to a gradual disintegration of the axoplasmic cytoskeleton, opposed to the previous view of an "all-or-nothing'' process (Griffin et al 1995). We also report that, due to an unknown mechanism, fibers show either a dark or watery pattern of axonal degeneration, as observed in axon profiles. We also observed fibers undergoing early myelin breakdown in the absence of axonal alterations

Ultrastructure changes of electrical injury in rats / 法医学杂志

OBJECTIVE@#To observe ultrastructure changes of electrical injury in rats.@*METHODS@#An experimental model of rats suffered from the low voltage were designed. Ultrastructure changes of electrical injured tissues were observed under transmission electron microscope.@*RESULTS@#(1) Plasma of epithelium was concreted in the affected areas and inner membrane system was broken. (2) Hypercontraction bands were observed in skeleton muscles. (3) There was dissolved necrosis and hypercontraction bands in the myocardium. (4) Vacuoles were found in plasma of endothelium of blood vessels on electrical current path, and myelin sheath of nerve fiber were loosed.@*CONCLUSION@#The above mentioned ultrastructure changes could be used as assistant diagnostic index of electrocution. The mechanism of the changes were discussed.

Congenital insensitivity to pain with anhidrosis: a case report

Congenital insensitivity to pain with anhidrosis (CIPA) is a very rare genetic disorder of the peripheral nervous system characterized by recurrent episodes of unexplained fever, generalized anhidrosis, insensitivity to pain and temperature, and accompanied by self-mutilating behavior and mental retardation. We report on a 16 month-old boy with CIPA who exhibited these characteristic clinical features. A sural nerve biopsy revealed markedly reduced numbers of unmyelinated and small myelinated fibers, consistent with the characteristic features of CIPA.

Estudo das alteraçöes das fibras musculares estriadas esqueléticas desnervadas por longo período / A study of the long-term denervation on the striated muscle

A porcentagem de células satélites rapidamente diminui no músculo sóleo de rato em regeneraçäo desprovido de inervaçäo. Assim também a desnervaçäo de músculos intactos causa a degeneraçäo e a perda de fibras sendo o comportamento das células satélites nestas condiçöes desconhecido. Mionúcleos com características de apoptósis têm sido observados em músculos desnervados, porém sem comprovaçäo deste fenômeno. Os músculos sóleo e extensor longo dos dedos (EDL) foram desnervados experimentalmente em ratos com 5 semanas de idade e investigados em diferentes períodos pós-desnervaçäo. A técnica do Ensaio Cometa foi utilizada em músculos desnervados por mais de 30 semanas para se detectar possíveis quebras de DNA associadas com apoptósis. Miotubos indicando regeneraçäo foram observados no músculo sóleo e parte profunda do músculo EDL após 7 semanas de desnervaçäo e na parte superficial do músculo EDL somente 16 semanas após desnervaçäo. Quase todas as células satélites desapareceram após 30 semanas de cirurgia em ambos os músculos. A desnervaçäo de músculos esqueléticos de ratos causa em adiçäo a atrofia de suas fibras, perda de fibras com subsequente regeneraçäo. A proliferaçäo das células satélites em músculos desnervados leva a exaustäo de "pool" de células satélites. Mionúcleos em músculos desnervados exibem quebras do DNA as quais podem ser demonstradas através da técnica do Ensaio Cometa.

Limits of variation of fiber distribution in the sural nerve of man

Although the sural nerve is the most extensively studied nerve in man, there is a dearth of data regarding the normal variations in the size-frequency distribution of axons in normal subjects; criteria for assessing the normality of a given individual are not available. Therefore, in everyday practice, the surgical pathologist may meet with difficulty in interpretit the biopsy of one particular individual, in whom the distribution is slightly different from the curves published. The object of this work is to detect the normal limits of variation in the distribution of diameters of muelinated and unmyelinated fibers in normal subjects and to establish the criteria that permit the calculated curves to be used in veryday clinical practice. Normal sural nerves of 19 patients were analyzed. Ages ranged between 18 months and 55 years. Morphometric analysis was performed with the Histoscan X automatic image processing analyzer, and , for statistical analysis, mixtures of lognormal distributions were fitted and tested with Pearson's statistics. Nerves of three diabetic patients were used for testing the method. They were clearly classified as abnormal. The curves, therefore, have been proven useful for everyday surgical pathology practice

Ultrastructure of the Merkel corpuscles of the lower lip mucosa inferior del mono cebus apella

Se estudió la ultraestructura de los corpúsculos de Merkel en la mucosa del labio inferior del labio de los monos Cebus apella. Las células de Merkel se localizan en la base de la red epitelial adyacente e intimamente asociada con una o dos terminaciones nerviosas intra-epiteliales. Las células de Merkel poseen un núcleo dentado, caracterizado por la concentración de numerosos gránulos denso-teñidos con un rango que varía de 30 a 80 nm de diámetro. Las protrusiones citoplasmáticas de las células de Merkel se extienden en los espacios intercelulares, conteniendo microfilamentos paralelos orientados longitudinalmente. Se observan uniones tipo desmosomas entre el axón terminal y las células de Merkel y queratinocitos adyacentes. El axón terminal muestra la presencia de numerosas mitocondrias y vesículas claras que miden de 30 a 50 nm de diámetro. Nuestros hallazgos sugieren que la protrusión citoplasmática puede servir para detectar el movimiento de queratinocitos adyacentes y también relaciona la capa epitelial con el tejido conectivo de la lámina basal

Interstitial cells of the ovaries of the chick embryo: ultraestructural aspects of their innervation

En trabajos previos demostramos que en el ovario derecho atrófico y en la médula del ovario izquierdo funcionante del pollo experimental regresión las células germinales y epiteliales y se preservan las células intersticiales (Avila y col. 1987). El objetivo del presente trabajo fue analizar la relación de las fibras y terminaciones nerviosas con las células intersticiales en ambos ovarios durante la embriogénesis en el pollo. Para ello se utilizaron ovarios izquierdos y derechos de embriones de 7 a 19 días de desarrollo, los que fueron procesados para su estudio ultraestructrual y determinación ultracitoquímica de fosfatasa ácida. A los 7 días se encontraron células intersticiales aisladas en la región central de ambos ovarios, las cuales contenían REL, Golgi, mitocondrias con crestas tubulares y abundantes vacuolas lipídicas. Las fibras y teminaciones nerviosas eran escasas. A partir de los 11 días las células intersticiales se encontraron agrupadas en el ovario derecho y en la médula del ovario izquierdo y se relacionaban con fascículos nerviosos rodeados de células de Schwann. Los terminaciones nerviosas, en íntimo contacto con la membrana de las células intersticiales, contenían mitocondrias, microtúbulos y vesículas grandes y pequeñas, algunas con contenido electrodenso. Esta relación entre las células intersticiales y las fibras y terminaciones nerviosas fue más frecuente desde los 15 días. La actividad de fosfatasa ácida localizada en las células germinales y epiteliales, presentó una reacción más intensa a los 15 días en el ovario derecho y en la médula del ovario izquierdo. No se detectó actividad enzimática en las células intersticiales ni en las fibras y terminaciones nerviosas en las distintas edades estudiadas. Estos hallazgos sugieren que las fibras y terminaciones nerviosas serían necesarias para la diferenciación de las células intersticiales en ambos ovarios del embrión de pollo

Estudo micro-mesoscópico das granulaçöes aracnóides humanas / A micromesoscopic study of human arachnoid granulations

A anatomia funcional das granulaçöes aracnóides do seio sagital superior foi estudada por técnicas micro-mesoscópicas a fim de contribuir para esclarecimentos de vias de drenagem do líquido cerebrospinal através de seus componentes fibrosos. A disposiçäo dos elementos fibrosos foi analisada na base do pedículo, pedículo, centro e ápice da granulaçäo. A análise dos cortes seriados mostra na base do pedículo, centro e ápice da granulaçäo. A análise dos cortes seriados mostra na base do pedículo, malhas de colágeno com morfologia predominantemente circular orientando-se longitudinalmente no sentido do maior eixo do pedículo. Estes feixes emergem no centro da granulaçäo, ramificando-se a seguir em direçäo ao ápice e à periferia da granulaçäo. Os feixes elásticos possuem disposiçäo semelhante à descrita para feixes colágenos e delimitam, com estes, canais intercomunicantes desde a base do pedículo ao ápice da granulaçäo. Encontramos, na base do pedículo, feixes de fibras reticulares dispostos entre as malhas de colágeno. A cápsula fibrosa da granulaçäo encontra-se constituída de feixes colágenos e de pequena quantidade de fibras elásticas

Chronic progressive external ophthalmoplegia: II. A qualitative and quantitative electronnicroscopy study of skeletal muscles

Trata-se de estudo quantitativo das principais alteraçöes encontradas em microscopia eletrônica de biópsia de músculos somáticos 31 entre 34 pacientes com síndrome de oftalmoplegia externa crônica e progressiva (OECP). Os pacientes foram divididos em três grupos clínicos - A) 10 casos esporádicos, com OECP e fraqueza muscular; B) 9 casos com historia familiar positiva, OECP e fraqueza muscular; C) 15 casos com OECP, fraqueza muscular e alguns dos seguintes sintomas: retinopatia pigmentar, ataxia cerebrar, sinais piramidais e neuropatia periférica. Foram encontradas alteraçöes em todos os grupos (8 do grupo A. três do grupo B e 14 do grupo C). As avaliaçöes quantitativas de certos constituintes das fibras musculares, usando a técnica de contagem de pontos revelou: diminuiçäo da fraçäo-volumétrica de miofibrilas, aumento das fraçöes-volumétricas de mitocôndria, glicogênio e lípídeos. As fraçöes-volumétricas de mitocndria correlacionam positivamanete com o conteúdo lipídico, com a proporçäo de fibras do tipo 1 e com a percentagem de fibras com aumento da atividade enzimática oxidativa (definidas em estudo anterior). Os três grupos definidos clinicamente näo mostraram diferenças significativas em termos de proporçöes relativas dos constituintes analisados