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Biomedical subjects

V Santosh

Publications and source records attributed to V Santosh.

At least 19 recordsLinked to original sources

Cerebral zygomycosis.

Fifty-six patients with cerebral zygomycosis (mucormycosis) were seen during the period 1971-2001 in two tertiary care hospitals located in south India with tropical climate and catering to neurological diseases. Forty-four patients had rhinocerebral and twelve patients had isolated central nervous system (CNS) zygomycosis. Of these, ten were culture proven (Rhizopus oryzae in eight and Mucor in two); 30 were diagnosed as probable and 16 were diagnosed possible; mixed infections were seen in three patients. Diabetes mellitus was the predisposing condition in a majority (31/44) of patients with the rhinocerebral form of zygomycosis. The tissue obtained at biopsy/autopsy in either form showed necrotic/infarcted tissue with neutrophilic infiltration with broad non-septate hyphae showing irregular branching. The outcome was poor despite surgical excision and antifungal therapy. The high concentration of spores in a mouldy environment, the bird population and improper disposal of hospital waste may facilitate healthy hosts presenting with primary CNS disease.

Adolescent↗

Intramedullary glioependymal cyst and tethered cord in an infant.

INTRODUCTION: Intramedullary glioependymal cysts are rare congenital lesions of the spinal cord. Their association with another congenital lesion, i.e., tethered cord, is rarer still. RESULTS AND DISCUSSION: We present a case of intramedullary glioependymal cyst with a filar lipoma in an infant. The clinical features, terminology and pathogenesis are discussed. Many varieties of spinal cysts have been described. It is now believed that simple ciliated or goblet-containing intracranial and intraspinal cysts are endodermal rather than glioependymal in origin. The diagnostic criteria, too, have been defined. Although many of these lesions are developmental in origin their association with other congenital anomalies is rare.

Epidermal Cyst↗

Medulloblastoma with extensive nodularity: a variant occurring in the very young-clinicopathological and immunohistochemical study of four cases.

CASE REPORT: Four cases of medulloblastoma with extensive nodularity (MBEN) are described. The patients were 3 years of age or younger at diagnosis. Cranial CT scan disclosed multiple coalescing nodules with peculiar 'grape-like' architecture in three patients. A near total excision of the tumour was performed in all four patients. The patients are currently receiving radiation and chemotherapy. Histologically, the tumours were characterized by extreme nodularity with intranodular uniformity and low proliferative index. The internodular zones were extremely cellular, composed of undifferentiated, mitotically active cells. Bcl-2 protein expression was observed in the cellular zones but was distinctly absent within nodules. DISCUSSION: MBEN represents a variant that occurs in very young children but has a good prognosis. The favourable outcome is probably related to its spontaneous neurocytic differentiation. The pattern of Bcl-2 immunoreactivity in MBENs indicates that this protein could be a key player in the regulation of neuronal differentiation in medulloblastomas.

Cerebellar Neoplasms↗

Haemangioma calcificans.

Haemangioma calcificans is a relatively rare intracranial tumour, which is characterized by the presence of a calcified nodule in or near the brain. The patient is most often an adult of either sex, who develops seizures. The lesion can be large enough to produce raised intracranial pressure. The location of tumour is subcortical and often in the temporal lobe. It is usually solitary and benign in nature. Microscopically, there are thin-walled blood vessels separated by dense fibrous bands containing deposits of haemosiderin and calcium. On electron microscopy, tubular structures limited by a wall of electrodense material and irregular calcium deposits within them are prominent features. Four cases of haemangioma calcificans are described here with review of literature.

Adolescent↗

Tuberculous osteitis of clivus.

Tuberculous osteitis of clivus is rare. Its diagnosis is difficult because of the rarity of the site and the non-specific nature of the disease. Management consists of confirmation of diagnosis by biopsy and chemotherapy with anti-tubercular drugs. Meningitis may complicate the clinical course, increase morbidity and mortality.

Adult↗

Brain biopsy in Creutzfeldt-Jakob disease: evolution of pathological changes by prion protein immunohistochemistry.

The formation of protease-resistant prion protein (PrPsc) is considered to be an early event in the pathogenesis of Creutzfeldt-Jakob disease (CJD) and hence its demonstration in brain biopsies by immunohistochemistry is considered diagnostic. We analysed eight brain biopsies from the frontal cortex collected from different parts of India from cases diagnosed as CJD on clinical and pathological grounds for the expression of prion protein (PrP). The duration of illness in these cases varied from 2 months to 1 year. Immunohistochemistry was carried out on paraffin sections using two different clones (KG9 and 3F4) of monoclonal antibodies to PrP. Although all eight cases showed classical features of spongiform encephalopathy of varying severity, only five of the eight cases revealed PrP(sc) in the brain tissue. The immunolabelling was focal and all areas with spongiform change were not labelled. A temporal evolution in the staining pattern was evident - particulate diffuse labelling (synaptic type) in early stages (2 months), perivacuolar deposits in intermediate stages (5-6 months), and dense plaques in late stages (12 months).

Adult↗

Glioneuronal migration and development disorders: histological and immunohistochemical study with a comment on evolution.

Glioneuronal migration disorders of the brain evolve primarily due to aberration in neuronal migration, maturation and programming in the development of various topographic zones in the brain, following pathological alterations in glial and neuronal interactions. These are broadly referred as cortical dysplastic conditions. While these dysplastic conditions involving cerebral cortex present as drug resistant seizure disorder, those involving cerebellum present as mass lesions or slowly progressing vertigo. We report 17 cases, representing the histological spectrum of dysplastic, glioneuronal migration disorders which include, hemimegalencephaly (1), tuberous sclerosis (4), Sturge Weber Syndrome with focal dysplasia (1), Dysembryoplastic neuroepithelial tumor (7) and Lhermitte Ductos disease of cerebellum (2). The dysplastic neurons in varied stages of maturation showed neuronal cytoskeletal pathology similar to that in neuro degenerative diseases, especially when associated with cytomegaly. Similarly, cells exhibiting dual expression of glial and neuronal markers were noted in the cerebral dysplastic lesions. The dysplastic glial elements probably form the subependymal giant cell astrocytomas. Dysplastic neuronal elements form the nidus for DNT. When localized, surgical resection ameliorate the symptoms in many of these condition. Study of these conditions provide better insight into glioneuronal interaction and maturation of the brain.

Adolescent↗

Aneurysmal bone cyst of the temporal bone.

Aneurysmal bone cysts are uncommon lesions of the bone, which are benign and non-neoplastic in nature. They are commonly seen in the long bones. Their occurrence in the calvarium is rare. We report the occurrence of an aneurysmal bone cyst in the temporal bone of a young boy, which eroded the posterior part of the orbit to cause proptosis.

Bone Cysts, Aneurysmal↗

Hypothalamic tumour with haemorrhage.

Haemorrhage in low-grade glioma is rare. A 4-year-old boy presented with sudden loss of consciousness. CT scan of his head revealed anterior third ventricular tumour with bleeding, intraventricular haemorrhage and hydrocephalus. The boy expired within 26 h of the onset of his illness, and an autopsy revealed a haemorrhagic juvenile pilocytic astrocytoma arising from the lateral hypothalamus with intraventricular haemorrhage. Intracranial tumour as the cause of sudden death and tumour with bleeding are discussed.

Astrocytoma↗

Stroke in a young man with fibromuscular dysplasia of the cranial vessels with anticardiolipin antibodies: a case report.

A case of fibromuscular dysplasia (FMD), presenting with a non-hemorrhagic infarct is reported. Positivity of anticardiolipin antibodies suggested an immune response. A 40-year-old man presented with sudden onset of stroke, preceded by similar ischemic attacks. Computed tomography (CT) of the brain showed a recent non-hemorrhagic infarct in the left middle cerebral artery (MCA) territory and an old right MCA territory infarct. Serum was positive for anticardiolipin antibodies. These above findings were confirmed at autopsy. A portion of the internal carotid artery and the middle cerebral arteries on both sides revealed features of FMD, with thrombosis. This case suggests an immune mechanism for FMD, hitherto unobserved in the cerebral circulation.

Adult↗

Giant orbital and intracranial xanthogranuloma--a short report.

Xanthogranuloma are known to arise in the paranasal sinus or orbit. They may also arise primarily in the brain. Those arising from the sinuses or orbit might involve the intracranial cavity to some extent. But an extensive involvement of the cranial compartment is very rare. This report describes one such case.

Adolescent↗

Intracranial haemorrhage resulting from unsuspected choriocarcinoma metastasis.

A retrospective analysis of clinicopathological data of 10 patients with clinically unsuspected cerebral metastatic choriocarcinoma was carried out. All patients were young adult females. History of preceding pregnancy/abortion was forthcoming in 5 cases but none had a prior history of abnormal gestation. Features of raised intracranial tension followed by hemiparesis were the commonest presenting symptoms. A clinicoradiologic diagnosis of intracerebral haemorrhagic mass, either primary or secondary to tumour bleed, cortico-venous thrombosis or arteriovenous malformation, was entertained in 8 out of 10 cases. In other two cases, ring enhancing lesions prompted the diagnosis of granulomatous masses. Eight patients were operated upon, of whom two died after short hospital stay, and were autopsied. All had haemorrhagic masses noted at surgery/autopsy. Accurate diagnosis of metastatic choriocarcinoma was established only by histologic examination of these haemorrhages. This report emphasizes the importance of considering metastatic choriocarcinoma as an important differential diagnosis of haemorrhagic intracerebral lesions in women of child bearing age group. Measurement of serum/CSF level of HCG in suspected cases helps to implement early therapy. The diagnostic value of histopathologic examination of surgically resected blood clots in determining aetiology of intracerebral haemorrhagic masses is highlighted.

Adolescent↗

Vasculitic neuropathy in HIV infection: a clinicopathological study.

Vasculitis causing peripheral neuropathy may be the first sign of HIV infection. We report four such cases in whom the onset of peripheral neuropathy led to the detection of HIV infection. Two patients presented with features of mononeuritis multiplex, while the other two had a lumbosacral polyradiculopathy. A prior history of blood transfusion was forthcoming in one of the patients. Sural nerve biopsies in all the four cases and the muscle biopsy in two, histologically showed evidence of vasculitis. Immunohistochemically, the viral antigen was not demonstrable in any of the biopsies, but on electron microscope, virus-like particles were identifiable in the Schwann cell cytoplasm and the perivascular macrophages in one case. To the best of our knowledge, this is the only report that has documented the virus in the Schwann cells as well as the perivascular macrophages lending credence to the fact that these viruses are neurotropic as well as lymphotropic. Immunoglobulin deposits were not demonstrable in any of the cases, suggesting that direct viral invasion may have a role in the pathogenesis of peripheral nerve vasculitis.

Adult↗

Expression of p67 (Munc-18) in adult human brain and neuroectodermal tumors of human central nervous system.

p67 (Munc-18), is a neuron-specific protein of 67 kDa, known for its ability to bind with syntaxin and also to copurify with neuronal cdc2-like kinase. Earlier, in situ hybridization and immunocytochemical analysis of rat trigeminal ganglion and hippocampal cells demonstrated the specific localization of p67 in nerve cells and its rich distribution in axons. In the present study, we have looked for p67 expression in normal human brain and various neuroectodermal tumors. Immunohistochemical and Western immunoblot analysis of normal human brain tissue using antibodies against the N- and C-termini of p67 demonstrated the specific localization of this protein in postmitotic neurons but not in glia. Among neuroectodermal tumors, expression of p67 was observed in 100% of the tumors of neuronal origin studied, especially in the mature neuronal cell population of these tumors. Western immunoblot analysis of non-neuronal neuroectodermal tumors failed to reveal the expression of this protein in majority of cases. However, in gliomas and meningiomas, mild cytoplasmic immunohistochemical staining of neoplastic cells was noted in 64.7% and 25% of cases, respectively. Observed mild immunohistochemical staining of these tumors could be due to immunoreactivity to low molecular weight degraded products of p67, as seen on Western blot. The findings suggest that p67, by virtue of its ability to be expressed in postmitotic neurons of adult human brain and in tumors of neuronal origin, may serve as a molecular tool to understand the growth and differentiation of the nervous system in general.

Adult↗