The topographic distribution pattern and morphological features of Lafora-like bodies in the spin... more The topographic distribution pattern and morphological features of Lafora-like bodies in the spinal cord of the dog, cat, fox, and baboon were examined by light and electron microscopy. The caudal lumbar and the coccygeal parts of the spinal cords were the predilection sites for the bodies in all animals and were very prominent in the ventral columns and intermediate substance. The bodies mainly composed of branching filaments were preferentially located in neuronal processes and rarely in astrocytes. The histochemical characteristics of the bodies were identical in all animals and consisted mainly of polyglucosan.
The gracile nucleus and conus medullaris, the sites of predilection for spheroids and Lafora-like... more The gracile nucleus and conus medullaris, the sites of predilection for spheroids and Lafora-like bodies, were examined light and electron microscopically in 91 dogs ranging from 1 month to 19 years of age. The number of both structures showed a tendency to increase with age. Spheroids have already been found in younger dogs before the appearance of Lafora-like bodies. In the aged dog, intra-spheroidal Lafora-like bodies were occasionally observed. Correlative studies may yield clues on the pathogenesis of aging phenomena in the CNS.
Lafora-like bodies in an 8-year-old cat were studied light and electron microscopically and histo... more Lafora-like bodies in an 8-year-old cat were studied light and electron microscopically and histochemically. In addition to Lafora-like bodies composed of branching filaments, glycogen granules and electron-dense materials, abnormal accumulations of glycogen granules attracted attention. The most remarkable features were the developmental processes of the branching filaments originating directly from glycogen granules. Lafora-like bodies in the present study showed ultrastructural, histochemical, and enzymatic similarities to those described in the previous reports in Lafora's disease, glycogenosis and other cases. From these results, a certain disturbance of the glycogen metabolism is considered to be probably related to the productive mechanism of Lafora-like bodies.
Forty randomly selected dogs, arranged into three groups according to age, were examined light an... more Forty randomly selected dogs, arranged into three groups according to age, were examined light and electron microscopically. Lafora-like inclusion bodies were found in all cases of aged dogs without neurological signs. They appeared as PAS positive, round bodies measuring up to 15μm in diameter. Typically they had central cores and radiating peripheral lines. Electronmicroscopically, the inclusions consisted of irregularly clustered, short branching filaments measuring about 80–120 Å in diameter or of electrondense homogeneous or granular central cores with filamentous peripheral areas and located both in the perikarya and neuronal processes. The inclusions were disseminated all over the brain and spinal cord. The thalamic nuclei, a circumscribed area dorsal to the aqueduct, and the molecular layer of the superior colliculus were the most severely affected. The frequency of the inclusions showed age-dependency; the inclusions were not found in dogs younger than 2 years, but were extensive in all dogs of more than 8 years of age. The occurrence of the inclusions may therefore represent an age-dependent phenomenon. The relationship between the present findings and Lafora's disease is discussed.
Twenty-seven randomly selected dogs ranging from 1 month to 16 years of age were examined light- ... more Twenty-seven randomly selected dogs ranging from 1 month to 16 years of age were examined light- and electron microscopically. An intraneuronal inclusion body was found in 13 of 27 cases. In particular, 12 of 13 positive cases were elderly dogs of over 8 years of age. The inclusions showed amphophilic violet color with H.-E. stain and measured 3–42 μm in diameter. Histochemically, they were thought to be a glycoprotein complex. The inclusions were characterized by the electron microscopy and composed of aggregated cistern of RER closely packed with tubular structures. The individual tubules measured about 24 nm in diameter and had 11–13 subunits forming their walls. These constituents were very similar to those of microtubules. The occurrence of the inclusion bodies showed an apparent age-dependency.
The topographic distribution pattern and morphological features of Lafora-like bodies in the spin... more The topographic distribution pattern and morphological features of Lafora-like bodies in the spinal cord of the dog, cat, fox, and baboon were examined by light and electron microscopy. The caudal lumbar and the coccygeal parts of the spinal cords were the predilection sites for the bodies in all animals and were very prominent in the ventral columns and intermediate substance. The bodies mainly composed of branching filaments were preferentially located in neuronal processes and rarely in astrocytes. The histochemical characteristics of the bodies were identical in all animals and consisted mainly of polyglucosan.
The gracile nucleus and conus medullaris, the sites of predilection for spheroids and Lafora-like... more The gracile nucleus and conus medullaris, the sites of predilection for spheroids and Lafora-like bodies, were examined light and electron microscopically in 91 dogs ranging from 1 month to 19 years of age. The number of both structures showed a tendency to increase with age. Spheroids have already been found in younger dogs before the appearance of Lafora-like bodies. In the aged dog, intra-spheroidal Lafora-like bodies were occasionally observed. Correlative studies may yield clues on the pathogenesis of aging phenomena in the CNS.
Lafora-like bodies in an 8-year-old cat were studied light and electron microscopically and histo... more Lafora-like bodies in an 8-year-old cat were studied light and electron microscopically and histochemically. In addition to Lafora-like bodies composed of branching filaments, glycogen granules and electron-dense materials, abnormal accumulations of glycogen granules attracted attention. The most remarkable features were the developmental processes of the branching filaments originating directly from glycogen granules. Lafora-like bodies in the present study showed ultrastructural, histochemical, and enzymatic similarities to those described in the previous reports in Lafora's disease, glycogenosis and other cases. From these results, a certain disturbance of the glycogen metabolism is considered to be probably related to the productive mechanism of Lafora-like bodies.
Forty randomly selected dogs, arranged into three groups according to age, were examined light an... more Forty randomly selected dogs, arranged into three groups according to age, were examined light and electron microscopically. Lafora-like inclusion bodies were found in all cases of aged dogs without neurological signs. They appeared as PAS positive, round bodies measuring up to 15μm in diameter. Typically they had central cores and radiating peripheral lines. Electronmicroscopically, the inclusions consisted of irregularly clustered, short branching filaments measuring about 80–120 Å in diameter or of electrondense homogeneous or granular central cores with filamentous peripheral areas and located both in the perikarya and neuronal processes. The inclusions were disseminated all over the brain and spinal cord. The thalamic nuclei, a circumscribed area dorsal to the aqueduct, and the molecular layer of the superior colliculus were the most severely affected. The frequency of the inclusions showed age-dependency; the inclusions were not found in dogs younger than 2 years, but were extensive in all dogs of more than 8 years of age. The occurrence of the inclusions may therefore represent an age-dependent phenomenon. The relationship between the present findings and Lafora's disease is discussed.
Twenty-seven randomly selected dogs ranging from 1 month to 16 years of age were examined light- ... more Twenty-seven randomly selected dogs ranging from 1 month to 16 years of age were examined light- and electron microscopically. An intraneuronal inclusion body was found in 13 of 27 cases. In particular, 12 of 13 positive cases were elderly dogs of over 8 years of age. The inclusions showed amphophilic violet color with H.-E. stain and measured 3–42 μm in diameter. Histochemically, they were thought to be a glycoprotein complex. The inclusions were characterized by the electron microscopy and composed of aggregated cistern of RER closely packed with tubular structures. The individual tubules measured about 24 nm in diameter and had 11–13 subunits forming their walls. These constituents were very similar to those of microtubules. The occurrence of the inclusion bodies showed an apparent age-dependency.
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