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Biomedical subjects

N R Ghatak

Publications and source records attributed to N R Ghatak.

85 records · Page 5Linked to original sources
PubMed1971

Ependymal cyst of the spinal cord: case report.

A subarachnoid ependymal cyst of the spinal cord is rarely reported. A 44 year old man with a cyst compressing the lower spinal cord and conus medullaris is described. Excellent functional recovery followed excision of the lesion. The cells lining the cyst were histologically indistinguishable from normal ependymal cells, but, unlike the normal ependymal cells which are related to subependymal glial tissue, the cells lining the cyst abutted directly on the connective tissue forming the cyst wall. This is in contrast with ependymal lined cysts occurring within the conus medullaris, and intradural teratomatous cysts which consistently contain intracytoplasmic mucinous material. It is postulated that an ependymal cyst could result from isolation of ependymal cells from either the roof or floor plates during embryogenesis of the neural tube.

Adult↗
PubMedDate not supplied

Glial bundles in spinal nerve roots: a form of isomorphic gliosis at the junction of the central and peripheral nervous system.

A morphologic study of the spinal nerve roots was undertaken in three cases of Werdnig-Hoffmann disease to investigate the phenomenon of glial bundle formation. The glial elements extended along the ventral roots as discrete cylindrical bundles comprising a large number of parallel astrocytic processes and sparsely scattered cell bodies all enclosed by a basal lamina. The bundles tapered off at a variable distance from the root exit zones. The early stage of glial bundle formation was characterized by the protrusion of astrocytes into the neurilemmal tubes containing degenerated myelinated axons. It was concluded that axonal degeneration, evoking a glial reaction, was the initial event in this process. Subsequently, the reactive astrocytes from the vicinity of the root exit zones enter the neurilemmal tubes previously occupied by myelinated axons and migrated into the domain of the peripheral nervous system in an orderly fashion. Thus glial bundle formation might be considered a special form of isomorphic gliosis occurring in Werdnig-Hoffmann disease and also in several other conditions all sharing a common feature, namely, degeneration of axons within the spinal nerve roots.

Astrocytes↗
PubMedDate not supplied

Cerebral fat embolism following cardiac surgery.

We describe 3 cases of cerebral fat embolism associated with cardiac surgery. The autopsy findings suggested that in 2 cases, the embolic fat globules entered the systemic circulation directly as a result of protrusion of epicardial fat into the left atrial chamber along the suture line in one case, and through an atrial septal defect in the other. The characteristic latent interval between surgical trauma and onset of neurologic manifestations was lacking in both cases. The evolution of neurologic manifestations and the pathologic findings in the third case were similar to those usually seen in posttraumatic fat embolism. This study suggests that the pathogenetic mechanisms of cerebral fat embolism following cardiac surgery may vary in different cases. Also, it emphasizes the importance of autopsy in the investigation of this serious but preventable complication.

Adult↗
PubMedDate not supplied

Intrasellar primitive neuroectodermal tumor (PNET) in familial retinoblastoma: a variant of "trilateral retinoblastoma".

An infant with bilateral familial retinoblastomas was found at age 6 months to have a large mass within the region of the sella turcica. The histology, immunoreactivity and ultrastructure of the tumor showed primitive neuroectodermal cells. A small number of cells showed positive immunostaining to retinal S antigen. This represents a rare form of so-called trilateral retinoblastoma. In most cases of trilateral retinoblastoma, the intracranial non-metastatic tumor is within the pineal gland. The occurrence of such a tumor in the region of sella turcica is very unusual and its possible significance is discussed in regard to our current understanding of the susceptibility to carcinogenesis conferred by inheritance of the mutant retinoblastoma gene, Rb-1.

Antigens↗
PubMedDate not supplied

Interhemispheric cysts in association with agenesis of the corpus callosum.

Two cases of complete agenesis of the corpus callosum each with large interhemispheric cysts are presented. The first case is an adult patient with chronic renal failure secondary to adult polycystic renal disease who was neurologically asymptomatic until she had a seizure during hemodialysis. The second case is an infant, who was diagnosed in utero as hydrocephalic, with severe mental and motor retardation and intractable seizures. The clinicopathologic findings in the two cases are presented, along with a discussion of the possible etiologies and clinical significance.

Agenesis of Corpus Callosum↗