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Biomedical subjects

V V Radhakrishnan

Publications and source records attributed to V V Radhakrishnan.

At least 73 records · Page 4Linked to original sources
PubMed1994

Choroid plexus papillomas.

Choroid plexus papillomas (CPPs) are rare neoplasms accounting for less than 1% of all intracranial tumours. We present our experience with 13 consecutive cases managed by us between 1981 and 1991. There were eight children and five adults. Five patients had tumours in the 4th ventricle, four in lateral ventricle, one in the 3rd ventricle, two in the cerebellomedullary cistern and one in the cerebellopontine angle. The cerebellomedullary cistern is a rare site for CPPs. Although the 4th ventricle remains the common site for adult CPPs, in our series there was a higher incidence of posterior fossa papillomas even in children. Only six patients out of 13 underwent precraniotomy shunts. All patients had their tumours operated upon and verified histologically. Total excision of the tumour could be achieved in nine patients; only a sub total excision was possible in the remaining four. There were two surgical mortalities in the earlier part of this series. Two patients with subtotal excisions underwent radiation therapy; one of these had regrowth of the tumour and another was lost to follow up. The other nine patients are doing well with a follow-up ranging from 9 to 90 months. Surgical resection with the objective of achieving total excision should be attempted in these tumours.

Adolescent↗
PubMed1994

Mycotic aneurysms of the intracranial vessels.

The salient clinical and pathological features are reported of Aspergillus cerebral aneurysms in four young women who had undergone intra-abdominal surgery under spinal anaesthesia and developed clinical features of meningitis 7-16 days postoperatively. The circle of Willis showed ruptured aneurysm in the basilar artery and its branches. The role of iatrogenic factors in the pathogenesis of Aspergillus cerebral aneurysms is highlighted.

Abdomen↗
PubMed1994

Necrotizing myelopathy--a report of two cases with review of literature.

Necrotizing myelopathy is an uncommon neurological disorder. Till 1991, only 31 cases have been described in the literature. In this report, clinical and neuropathological features in two patients with necrotizing myelopathy are described. The precise aetiological agent in first patient was undetermined, However in the second patient there was serological evidence, suggestive of Herpes simplex virus infection.

Antibodies, Viral↗
PubMed1994

Diagnosis of tuberculous meningitis by enzyme-linked immuno-sorbent assay (ELISA), using an affinity chromatography purified mycobacterial antigen.

Using an immunoabsorbent affinity chromatography, a mycobacterial antigen was isolated from culture filtrate of H37Ra Mycobacterium tuberculosis (MTB). The immunoabsorbents were prepared by coupling cynogen bromide-activated Sepharose-4B with human IgG antibody to MTB. Cerebrospinal fluids (CSF) from 10 culture positive, 30 culture negative patients with tuberculous meningitis (TBM) were assayed, for IgG antibody to this mycobacterial antigen by ELISA. CSFs from 50 patients with non-tuberculous neurological diseases were selected as control group. At a selected 'cut off' titre of 1:80, 21 out of 30 CSFs from culture negative patients gave positive results. No false negative result was observed in CSF from 10 culture positive patients with TBM. No false positive results were recorded in CSFs of 50 patients with non-tuberculous neurological diseases. Technical aspects involved in the isolation of this myobacterial antigen and its potential applications in the laboratory diagnosis of TBM have been emphasised in this study.

Antibodies, Bacterial↗
PubMed1994

Disseminated intra-cerebral microabscesses: a clinico-pathologic study.

In this retrospective study, clinical and neuropathological features were analysed in eight patients with disseminated intracerebral microabscesses. All the patients presented with clinical features, suggestive of an encephalopathic process of an acute onset. Neuroradiological and laboratory investigations were not helpful in establishing the diagnosis in any patient during their hospital stay. All the eight patients died in the hospital and at autopsy disseminated intracerebral microabscesses were the most striking feature. In two patients hyphae of Candida albicans were demonstrated within the microabscesses. Gram negative bacilli in two patients and gram positive and gram positive cocci in one patient were demonstrated in the microabscesses. Disseminated intra-cerebral microabscesses are usually an unrecognised manifestation of central nervous system infections and should be considered in the differential diagnosis of patients with encephalopathy of unknown aetiology.

Adult↗
PubMed1994

Nodular inflammatory mass of the dura mimicking a meningioma--a report of two cases.

Histopathological examination of surgical specimens in two patients with an operative diagnosis of meningioma, revealed the presence of dense nodular aggregation of lymphocytes, plasma cells and conspicious absence of meningothelial components. Possibilities of lymphoreticular malignancy, myeloproliferative disorders and other causes for various inflammatory diseases were excluded by appropriate investigation in these two patients. Pathogenesis of this localised lymphocyte-plasma cell aggreation in the dura manifesting as a space-occupying lesion could not be defined in these two patients. It is emphasised that this benign lesion should be recognised as well as distinguished from secondary lymphomatous deposits and solitary plasmacytoma of the dura.

Adult↗
PubMed1994

Utility of silver-colloidal staining method in the diagnosis of medulloblastoma.

Histopathological features of medulloblastomas are usually distinctive. However in rare instances, a distinction between the neoplastic cells of medulloblastoma and the neurones in the cerebellar internal granular layer becomes difficult at light microscopic level. In order to distinguish presence of argyrophilic Nucleolar Organizer Regions (Ag-NORs) was analysed in the paraffin sections of medulloblastoma as well as in the cerebellar internal granular layer. The neoplastic cells in medulloblastoma contained a mean 4.78 Ag-NOR per nucleus while the neurones in cerebellar internal granular layer contained a mean Ag-NOR 0.90 +/- 0.12 per nucleus. Compound Ag-NORs were present in the cells of medulloblastoma while they were absent in the neurones of cerebellar internal granular layer. The results of this study indicate that Ag-NOR technique may be useful in an uncommon situation, where a histopathological distinction between cells of medulloblastoma and neurones in the cerebellar internal granular layer becomes difficult.

Cerebellar Cortex↗
PubMed1994

Intraventricular neurocytoma: a report of two cases.

Central neurocytomas are uncommon intracranial neoplasms. More than one hundred cases are documentated in the literature. In this report we describe the clinical and histopathological features in two patients with intraventricular neurocytoma. As the light microscopic features of neurocytoma resemble with that of an oligodendroglioma, it is essential to differentiate these two tumours, using either ultrastructural or immunohistochemical techniques.

Adult↗
PubMed1993

Nucleolar organizer regions in meningiomas.

Paraffin sections of 305 meningeal tumours were analysed for the presence of nucleolar organizer region (Ag-NOR) in the neoplastic cells, using a one step silver-colloidal staining method. The mean (+/- SEM) Ag-NOR counts were 2.73 +/- 0.21 for atypical and 2.91 +/- 0.18 for papillary variants of meningioma. In meningotheliomatous and transitional variants of meningioma, the mean Ag-NOR counts were 1.41 +/- 0.34 and 1.38 +/- 0.31, respectively. The recurrence rates were significantly higher in atypical meningiomas than in other histopathological variants (p < 0.05). Differences in the mean Ag-NOR numbers between meningothelial and transitional variants in their primary and recurrent tumours were not significantly different (p > 0.05). The results of this study indicates that estimation of Ag-NORs can be applied in predicting the aggressive clinical behaviour of primary meningeal tumours.

Brain↗
PubMed1993

Correlation between the isolation of Mycobacterium tuberculosis and estimation of mycobacterial antigen in cisternal, ventricular and lumbar cerebrospinal fluids of patients with tuberculous meningitis.

In the study Mycobacterium tuberculosis was isolated in the cerebrospinal fluid (CSF) specimens of patients with tuberculous meningitis (TBM) by the conventional bacteriological technique. The isolation rate of M. tuberculosis was found to be 11.5% in lumbar, 75% in ventricular and 87.5% in cisternal CSFs. Low isolation rate of M. tuberculosis in lumbar CSF is due the low density of tubercle bacilli in lumbar CSF than in cisternal CSF. However M. tuberculosis antigen 5 is present in significant concentration in CSFs. The antigen concentration in CSF was estimated by an inhibition enzyme-linked immunosorbent assay (ELISA). Since CSF specimens can not be collected from ventricular or cisternal routes for the routine bacteriological investigations in patients with TBM, estimation of M. tuberculosis antigen 5 concentration in lumbar CSF by an inhibition ELISA may be considered as an adjunct in the laboratory diagnosis of TBM. This is particularly relevant in those patients in whom bacteriological methods fail to demonstrate M. tuberculosis in CSF specimens.

Antitubercular Agents↗
PubMed1993

Papillary meningioma--a clinicopathological study of six cases.

Papillary meningioma is a rare but a well recognised histological variant of meningioma. Only 52 cases are reported in literature till 1991. This report highlights the clinical and histopathological features of papillary meningioma in six patients. Significance of making an accurate histopathological diagnosis and its relevance in the management of patients with papillary meningioma is emphasised.

Adult↗
PubMed1993

Transcallosal approach to anterior and mid-third ventricular tumors--a review of 62 cases.

Sixty-two consecutive patients with anterior and mid-third ventricular lesions were operated on by a limited anterior transcallosal approach from 1987 to 1992. Fifty-six cases were operated on by B K M. Following lateral ventricular entry, transforaminal route to the third ventricle was preferred and utilised in 44 cases. An interfornicial or subchoroidal approach was employed only if transforminal entry was not adequate and was the route in 16 and two cases respectively. Enlargement of the foramen of Monro by incising its margins was not resorted to in any case. The age of the patients ranged from six to 64 years, (mean 29 years). Males were twice as often affected as females. There were 50 benign lesions: 43 colloid cysts, two craniopharyngiomas, one arachnoid cyst and four cysts of uncertain histology, and 12 malignant tumours: eight intrinsic astrocytomas, two oligodendrogliomas, one ependymoma and one primary lymphoma. The outcome in the benign cases was excellent in 42, good in six and poor in one. There was one post-operative death due to meningitis.

Adolescent↗
PubMed1993

Application of silver colloidal staining method in the diagnosis of intracranial glioma.

A silver colloidal staining technique for the demonstration of argyrophilic nucleolar organizer regions (Ag-NORs) was used on the paraffin sections of reactive gliosis and grade I astrocytoma tissue. Quantitative as well as qualitative differences of Ag-NORs were found between the cells of reactive gliosis and grade I astrocytoma. In cases of reactive gliosis, the Ag-NOR counts averaged 1.19 +/- 0.16 per nucleus, while in grade I astrocytoma, Ag-NOR counts averaged 2.36 +/- 0.32 per nucleus (P < 0.05). Compound Ag-NORs were also seen in the nuclei of cells in grade I astrocytoma while they were not present in the nuclei of cells in cases of reactive gliosis. The results of the study indicate that Ag-NOR technique is an useful method and can be applied in situations where a distinction between grade I astrocytoma and reactive gliosis becomes difficult at the light microscopic level.

Astrocytoma↗
PubMed1993

Primary lymphoma of the brain.

In this study, clinical and histopathological features of primary lymphomas of the brain have been described in eight patients. The primary nature of lymphoma in these patients was confirmed by extensive clinical as well as radiological investigations and supported by a detailed histopathological examination. Computerised tomography (CT) scan showed multiple intra-cerebral lesion in two patients and in six patients the lesion was solitary. Although primary lymphoma of the brain carries poor prognosis, it is essential that these tumours should be accurately diagnosed as well as should be distinguished from secondary tumours.

Adult↗