Dysferlinopathy: Spectrum of pathological changes in skeletal muscle tissue.

Background: Dysferlinopathy is an autosomal recessive-limb girdle muscular dystrophy (AR-LGMD) caused due to the defect in gene encoding dysferlin, a sarcolemmal protein. Awareness of the variants and their relative frequency is essential for accurate diagnosis. Aim: To study the spectrum of morphologic changes in immunohistochemically proven cases of dysferlinopathies, to correlate the findings with clinical phenotype and durations of illness and determine the frequency. Materials and Methods: Dysferlinopathies seen over a period of 2 years at a tertiary neurological center were analyzed. Results: Clinically, majority had Miyoshi phenotype (46.6%) with distal involvement and LGMD phenotype (40%) with proximal muscle involvement. In addition, a proximo-distal and tibial muscle phenotype was encountered. Morphologically, rimmed vacuoles were noted in the Miyoshi phenotype. The presence of ragged red fibers, lobulated fibers and inflammation had no preference to a particular phenotype. Significant atrophy and lobulated fibers were noted in patients with longer duration of illness. Conclusions: Dysferlinopathy was the second most common identifiable cause (21%) of LGMD next to sarcoglycanopathies (27%).

Acidification of the parasitophorous vacuole containing Toxoplasma gondii in the presence of hydroxyurea

Toxoplasma gondii se multiplica dentro do vacúolo parasitóforo que não é reconhecido pela defesa primária não oxidativa de células hospedeiras: a fusão com organelas ácidas. Estudos anteriores mostraram que hidroxiuréia interrompeu a multiplicação dos parasitos intracelulares causando sua eliminação. No presente trabalho nós investigamos o mecanismo celular envolvido na destruição do Toxoplasma gondii intracelular. Marcadores vitais fluorescentes foram usados para observar a possível acidificação do vacúolo parasitóforo contendo Toxoplasma gondii na presença de hidroxiuréia. Células Vero infectadas com taquizoítos foram tratadas com hidroxiuréia por 12, 24 ou 48 horas. Fluorescência indicativa de acidificação foi observada no vacúolo parasitóforo quando as culturas foram incubadas na presença de laranja de acridina. Lyso Tracker red foi usado para determinar se os lisossomos estavam envolvidos no processo de acidificação. Uma fluorescência intensa foi observada depoisde 12 e 24 horas de incubação com hidroxiuréia, alcançando uma intensidade maior após 48 horas de tratamento. Citoquímica ultraestrutural para localização da enzima fosfatase ácida lisossomal foi realizada. As culturas infectadas e tratadas apresentaram produto de reação em vesículas se fundindo com o vacúolo ou associado com parasitas intravacuolares. Estes resultados sugerem que a fusão com lisossomos e acidificação do vacúoloparasitóforo causa a destruição dos parasitos na presença de hidroxiuréia.

Morphological alterations of the parotid gland of rats maintained on a liquid diet

Esse trabalho teve por objetivo analisar as alterações morfológicas das glândulas parótidas de ratos submetidos a uma dieta líquida. Trinta e seis animais foram divididos aleatoriamente em dois grupos. O grupo controle recebeu dieta sólida, e o grupo experimental recebeu dieta líquida. Os animais foram sacrificados 8, 15 e 30 dias após o início da experimentação. As glândulas foram incluídas em parafina e analisadas no microscópio de luz. Os resultados mostraram uma redução estatisticamente significante no peso das glândulas parótidas dos animais do grupo experimental quando comparado aos dos animais do grupo controle nos períodos de 15 e 30 dias. A alteração morfológica mais importante foi a evidenciação de vacúolos no citoplasma das glândulas parótidas dos animais alimentados com dieta líquida. Os vacúolos citoplasmáticos reagiram negativamente às técnicas de coloração específicas para glicoproteínas e mucopolissacarídeos (PAS e Alcian blue). Concluiu-se que a dieta líquida causou atrofia das glândulas parótidas nos períodos experimentais de 15 e 30 dias.

Light and electron microscopic examination of human subungual tissue Glomus and lamellated bodies

There is only limited data related to the subungual glomus body. We therefore studied the structure of this organ, aiming to obtain further evidence. Additionally, we encountered undefined receptor like structures in close association with these glomus cells, named them as lamellated bodies and examined both of the structures at light and electron microscopic levels. This study was carried out at the Faculty of Medicine, Hacettepe University, Ankara, Turkey, during the time period May 2001 to March 2002. In this study, the subungual tissues of 4 patients were examined. Within subungual tissue, 2 groups of morphologically significant structures were determined by light microscopy. The first structure was described as glomus body. It was characterized as an encapsulated structure, rich in rounded clear cells filling its central compartment. The latter structure having a lamellated appearance was described as lamellated body. In the electron microscopic examination, lamellated bodies were characterized by central filament rich large cells and surrounding cytoplasmic processes of ensheathing cells, some of which were vacuolated. Glomus bodies were surrounded by a capsule and centrally located numerous rounded cells which reflected the structural features of an active cell. The lamellated bodies are very unusual structures and they are not found in any other part of the body. The structural organization of the ensheathing cells in the lamellated bodies greatly resembles many skin associate receptors. Therefore, we planned future studies by using immunohistochemistry, to reveal nervous elements for structural contribution

Behaviour of microtubules in cells infected with Toxoplasma gondii

Toxoplasma gondii proliferates within the parasitophorous vacuole of the host cell. Simultaneously with parasite division and vacuolar development, lipids traffic and change in the spatial distribution of organelles of the host cell cytoplasm occur. Using fluorescence microscopy, and antibodies recognizing tubulin, we showed that microtubules change their distribution during host cell infection by tachyzoites of T. gondii. In addition, transmission electron microscopy of thin sections and replicas of partially extracted cells showed that host cell microtubules concentrate around the parasitophorous vacuole. Such microtubules distribution was evident in early infection times and was more prominent after 24 h of infection, when parasitophorous vacuole was completely surrounded by microtubules. However, the meshwork microtubule filaments became slack or absent after 72 h of infection of host cell. Colchicine and taxol treatment altered the shape of the parasitophorous vacuole containing tachyzoites. These observations suggest a close association between microtubules and intravacuolar development of parasites.

Corpos de inclusäo citoplasmática: estudo em diversas doenças e revisäo da literatura / Cytoplasmic inclusion bodies: a study in several diseases and a review of the literature

Estudamos 16 casos entre 1400 biópsias musculares que apresentavam vacúolos marginados, cujo aspecto histológico sugeria corpos de inclusao citoplasmáticos. Procuramos correlacionar os dados clínicos, laboratoriais e histopatológicos, a fim de determinar a especificidade dos corpos de inclusao citoplasmáticos para determinadas doenças. A creatinaquinase mostrou-se elevada em 1O casos. A eletromiografia foi anormal em todos os casos. A histoquímica muscular em 5 casos revelou uma miopatia, em 7 padrao misto, em dois desinervaçao e em 2 casos miopatia inflamatória. A microscopia eletrônica demonstrou a presença de filamentos em 8 casos (nucleares, dispersos no citoplasma ou na regiao subsarcolemal). Os pacientes foram classificados conforme a história clínica, hereditariedade, dados laboratoriais, eletrofisiológicos, histoquímicos e microscopia eletrônica. Encontramos miosite com corpos de inclusao citoplasmática (4 casos), atrofia muscular espinhal juvenil (6 casos), miopatias distais (3 casos), distrofia de cinturas pélvica e escapular (2 casos) e polineuropatia periférica (1 caso). Apresentamos revisao sobre a patogenia, formaçao e possível etiologia dos vacúolos marginados e sua relaçao com as diversas entidades em que foram detectados, sugerindo que nao sao específicos para uma única doença.

Sodium chloride stress induced morphological and ultrastructural changes in Aspergillus repens.

Halotolerant fungus, A. repens, showed a considerable difference in its growth rate, morphology, ultrastructural and molecular composition under NaCl stress as compared to control i.e. non-stressed condition. Light microscopic observations revealed significant differences in their mycelial thickness, their branching and septa. Transmission electron microscopic observations of both the conditions depicted significant differences in the qualitative and quantitative changes in mitochondria. Frequent pinocytotic vesiculation (vacuoles) of plasma membrane was observed in fungus under stress but no such vesiculation in control. The multivesiculate structures observed under stress with their origin from the cell membranes and subsequent release into vacuoles have not been reported in fungi under normal physiological conditions. The observations on pinocytosis are discussed in relation to ion compartmentation and salt tolerance in A. repens.

Electron microscopic study on overacting inferior oblique muscles

Overaction of the inferior oblique(IO) muscle is manifested by elevation of the adducted eye and from the clinical point of view there are two types of overaction. The primary type is of unknown cause, whereas the secondary type is usually related to the palsy of the ipsilateral superior oblique or contralateral superior rectus. An ultrastructural study on the overacting IO muscles was performed compared to normal IO muscles by electron microscopy. Of 16 biopsies of overacting IO muscles, four had primary overacting inferior obliques and twelve had secondary overacting inferior obliques due to paralysis of superior oblique muscle. Additional four IO muscle, obtained from patients with intraocular diseases served as control specimens. The most striking abnormalities were aggregations of mitochondria and degenerating mitochondrial profiles and increased vacuolization in primary and secondary overacting muscles. Many muscle fibers were in different stages of atrophy, and hypertrophy and regeneration of muscle fibers were sometimes visible. The results suggest that the primary overacting IO muscle might be the result of a paresis of the superior oblique muscle.

Localización intracelular de vacuolas con actividad de fosfatasa ácida en trofozoitos de entamoeba hystolitica adheridos a epitelio cecal de cobayo / Intercellular distribution of acid phosphatas evacuadas in entamoeba histolytica trophosortes adhered to guinea pig cecal ephithelium

Con el objetivo de dilucidar la distribución y el posible papel que desempeñan las vacuolas positivas a la fosfatasa ácida (VFAs) de los trofozoítos de Entamoeba histolytica, durante la fase inicial de interacción de la amibas con el epitelio intestinal; se utilizó como modelo experimental el epitelio cecal del cobayo, que se incubó in vitro con trofozítos de E. histolytica de la cepa HM1;IMSS. Despues de 30 minutos de interación entre las amibas y el epitelio, los trofozítos se observaron en las siguientes situaciones: a) adheridos a epitelio morfológicamente intacto; b) adheridos a cúmulos de células epiteliais descamadas; c) en proceso de fagocitosis de células epiteliales en descamación y restos celulares; d) en proceso de invasión a través de las zonas de descamación. Los trofozoítos en fase a y b mostraron en el citoplasma numerosas VFAs, distribuídas en forma irregular. Las amibas en fase c tuvieron las VFAs localizadas en la zona citoplámica opuesta al estoma de fagocitosis. La VFAs, así como fagosomas que tuvieron producto de reaccicón de fosfatasa ácida, se observaron distribuidos irregularmente en los trofozoítos en fase d. La integridad del revestimiento epitelial con amibas adehridas, el hecho de que la invasión y destrucción del epitelio se observó exclusivamente a través de las zonas de descamación y la ausencia de VFAs en el citoplasma amibiano en fase de expulsión de posibles productos tóxicos para las células epiteliales, son evidenciais de que las VFAs no participan en el daño inicial del epitelio, sino que sólo parecen estar involucradas en la digestión del material fagocitado