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Biomedical subjects

V V Radhakrishnan

Publications and source records attributed to V V Radhakrishnan.

At least 19 recordsLinked to original sources
PubMed2002

A comparative evaluation of dot immunobinding assay (Dot-Iba) and polymerase chain reaction (PCR) for the laboratory diagnosis of tuberculous meningitis.

The results of a Dot immunobinding assay (Dot Iba) for the detection of mycobacterial antigen in the cerebrospinal fluid (CSF) of 45 patients with tuberculous meningitis (TBM) were compared with the results of a polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis. In eight patients with culture proven TBM, Dot-Iba gave positive results, while PCR yielded positive results only in six patients. The overall sensitivities of Dot-Iba and PCR in 37 patients with culture negative (probable) TBM were 75.67% and 40.5% respectively. Dot-Iba, in contrast to PCR is a rapid and relatively easier method. More importantly, Dot-Iba is suitable for the routine application for the laboratory diagnosis of TBM and therefore best suited to laboratories in the developing world.

Antigens, Bacterial↗
PubMed2002

Immunocytochemical method for early laboratory diagnosis of tuberculous meningitis.

A simple immunocytochemical method was standardized for the direct demonstration of mycobacterial antigen in cerebrospinal fluid (CSF) specimens of patients with tuberculous meningitis (TBM). CSF-cytospin smears were prepared from 22 patients with a clinical diagnosis of TBM and also from an equal number of patients with nontuberculous neurological diseases (disease control). Immunocytological demonstration of mycobacterial antigens in the cytoplasm of monocytoid cells was attempted, by using rabbit immunoglobulin G to Mycobacterium tuberculosis as the primary antibody. Of the 22 CSF-cytospin smears from TBM patients, 16 showed positive immunostaining, while all of the CSF-cytospin smears from the disease control showed negative immunostaining for mycobacterial antigen. The technical aspects of this immunocytological method for the demonstration of mycobacterial antigens are simple, rapid, and reproducible, as well as specific, and therefore can be applied for the early diagnosis of TBM, particularly in patients in whom bacteriological methods did not demonstrate the presence of M. tuberculosis in the CSF.

Antigens, Bacterial↗
PubMed2002

Idiopathic hypertrophic cranial pachymeningitis.

Idiopathic hypertrophic cranial pachymeningitis is a rare form of fibrosing chronic inflammatory process of unknown etiology, which causes thickening of the intracranial dura mater. We present four patients with hypertrophic cranial pachymeningitis who presented with chronic headache and cranial nerve palsies. The diagnosis of idiopathic hypertrophic cranial pachymeningitis was based on neuroimaging findings of thickened enhancing dura, exclusion of known causes and histopathologic findings compatible with nonspecific inflammation in the meningeal biopsies. Corticosteroid therapy was effective in all cases in inducing a complete or partial remission of the neurologic symptoms and signs. We describe the clinical, radiological and pathological features of idiopathic hypertrophic cranial pachymeningitis and discuss the relationship of this entity with other inflammatory fibrosclerotic disorders to explain the pathogenesis. A high index of suspicion, prompt confirmation of the diagnosis by meningeal biopsy, and early institution and long-term maintenance of steroid therapy may help to prevent irreversible neurologic sequelae, especially blindness.

Adrenal Cortex Hormones↗
PubMed2002

Infrasellar craniopharyngioma mimicking a clival chordoma: a case report.

An unusual case of entirely infrasellar craniopharyngioma mimicking a clival chordoma is described. Only 22 cases of craniopharyngioma with nasopharyngeal extension have been reported in the literature. Of the reported cases, most were primarily intracranial with secondary downward extension; only two were thought to originate from an infrasellar location. The present case is another example of an entirely infrasellar craniopharyngioma, with extensive clival destruction, mimicking a clival chordoma. Relevant literature on the subject is reviewed.

Adult↗
PubMed2001

Acoustic neurinomas during pregnancy: report of two cases and review of literature.

Though infrequent, acoustic neurinomas have been described during pregnancy and represent a therapeutic challenge for excision without producing any problem for the mother and the foetus. First Author experienced two cases of acoustic neurinomas presenting during pregnancy. One patient presented in the terminal stages of the third trimester of pregnancy and underwent caesarean section, followed by retromastoid craniectomy and excision of the tumour. Operative management of the pregnancy and tumour in the same sitting has not been reported in the literature. Second patient who presented during 2nd trimester of pregnancy, was operated on for the tumour and had a successful continuance of pregnancy. Details of the management are discussed and the relevant literature reviewed. In addition to causing aggravation of symptoms, the larger size and increased vascularity of these tumours during pregnancy, makes them more vulnerable to acute bleeding, which in turn may initiate new or exacerbate pre-existing symptoms, as noted in one of the cases presented in this report.

Adult↗
PubMed2001

A newer approach for the laboratory diagnosis of tuberculous meningitis.

In this prospective study, a simple method was standardized for measuring circulating mycobacterial antigen in the cerebrospinal fluid (CSF) for the laboratory diagnosis of tuberculous meningitis (TBM). The heat-inactivated CSF specimens from tuberculous and non-tuberculous patients were subjected to sodium dodecyl sulfate (SDS) - polyacrylamide gel electrophoresis (PAGE) (SDS-PAGE) and they were subsequently transferred onto nitrocellulose membrane (NCM) Using a rabbit polyvalent antibody to M tuberculosis, a heat stable 82 kDa mycobacterial antigen was demonstrated in the CSFs of patients with TBM. This antigen was conspicuous by its absence in the CSFs of non-tuberculous subjects. Due to inactivation of CSF specimens, there is a minimal risk of handling of infectious material in the laboratory. Besides, this newer approach is simple, inexpensive and can be readily applied in any routine clinical laboratory and it is particularly suited to developing countries.

Animals↗
PubMed2001

Solitary metastasis from occult follicular carcinoma of the thyroid mimicking trigeminal neurinoma--case report.

A 50-year-old woman presented with an extremely uncommon case of solitary metastasis from follicular carcinoma of the thyroid, which presented clinically as trigeminal neurinoma. Neuroimaging detected a tumor in the right petrous apex, which was removed surgically. Histological examination showed metastatic follicular carcinoma of the thyroid. However, no primary tumor was detected by various investigations. The tumor recurred twice, and was treated surgically both times. The patient finally agreed to adjuvant therapy for the suspected primary. Radiotherapy was performed followed by complete thyroidectomy. Examination of the gross specimen found the tumor nodule. Clinically significant metastasis can arise from histologically benign and silent follicular thyroid neoplasms.

Adenocarcinoma, Follicular↗
PubMed2001

Neurocysticercosis: a clinical and radiological appraisal from Kerala State, South India.

OBJECTIVES: Little has been published on Neurocysticercosis (NCC) in the State of Kerala, South India. This study was conducted to describe the clinical and radiological features of NCC in Kerala and also to study the frequency of NCC as seen in a tertiary referral setting. MATERIALS AND METHODS: We evaluated retrospectively 11 patients who were admitted with a diagnosis of NCC from 1986 to 1998. A pre-abstracted proforma containing detailed demographic data, dietary habits, clinical features and history of travel outside Kerala and neuroimaging findings were obtained from patient records and the data was tabulated and analysed. Follow up assessment was made three months after treatment. RESULTS: There were a total of 11 patients, including nine males and two females in the age range of 24 to 62 years and a mean age of 35.2 years. All were nonvegans, only 36% were pork eaters while 18% claimed consumption of salads and uncooked vegetables. 55% of patients were migrants. Migrants were defined as those who lived outside the state of Kerala for more than six months. Seizure was the most common presenting complaint and occurred in all patients (100%). Multiple ring enhancing lesions were seen on computerised tomography (CT) and magnetic resonance imaging (MRI) scans in 60%. Calcified lesions were noted in two patients. An isolated instance of miliary or disseminated cysticercosis with subcutaneous nodules and multiple brain lesions in MRI scan was observed. All patients received anticysticercal therapy besides anticonvulsants. CONCLUSIONS: It appears that NCC is rather uncommon in Kerala. Better socioeconomic status, high literacy rate, improved sanitation and health care in the state of Kerala could be reasons for this observation. A prospective case-control study of NCC in Kerala is needed to study these factors.

Adult↗
PubMed2001

Mixed tumour of schwannoma and meningioma in a patient with neurofibromatosis-2 : a case report.

The co-existence of schwannoma and meningioma as a mixed intracranial tumour is uncommon and so far only eight cases have been published in the literature. Because of rarity, we report a unique case of mixed tumour having schwann cell and meningeal components, in a patient with neurofibromatosis type -2 (NF-2). The possible mechanisms for the occurrence of these mixed tumours are discussed.

Adult↗
PubMed2001

Significance of serum antibody to GD1b ganglioside in patients with Guillain-Barré syndrome.

BACKGROUND & OBJECTIVES: The precise etiological factors in Guillain-Barré syndrome (GBS) are still unknown. However, humoral and cellular immune factors may have a role in the pathogenesis of GBS. The present study was undertaken to evaluate the clinical significance of circulating serum IgG antibody to GD1b ganglioside in patients with GBS. METHODS: Serial samples of serum were collected from 18 patients with GBS undergoing plasma exchange (PE) during their hospital stay. Serum IgG antibody titers to GD1b, before, during as well as following PE were measured by an indirect enzyme-linked immunosorbent assay (ELISA). RESULTS: In 10 of 18 patients with GBS the antibody to GD1b was present in high titers (1:640-1:5120) prior to PE and the antibody titers in these 10 patients decreased following PE. At the time of completion of the study, the anti GD1b antibody titers declined in relation to clinical recovery in 7 of 10 patients with GBS. INTERPRETATION & CONCLUSION: The findings of the present study show that antibody to GD1b gangliosides may be one of the immunological factors in the pathogenesis of GBS and PE decreases the anti GD1b antibody titers in these patients.

Antibodies↗
PubMed2001

A dot-immunobinding assay (dot-Iba) for rapid diagnosis of pulmonary tuberculosis.

IgG antibody to Mycobacterium tuberculosis from the sera of patients with 'definite' pulmonary tuberculosis (PT) was isolated and coupled with Cyanogen bromide-Sepharose 4B. Using an immunoabsorbent affinity chromatography, 14 kDa antigen was recovered from the culture filtrates of M. tuberculosis. With this mycobacterial antigen, a dot immunobinding assay (Dot-Iba) was developed for the detection of specific antibody to M. tuberculosis in the sera of patients with PT and controls. The assay gave positive results in all the 12 sputum-smear positive [acid fast bacilli (AFB)] patients with PT and gave negative results in the 50 sera from control groups. The Dot-Iba as described in this study, is simple, rapid and specific for laboratory diagnosis of PT.

Adolescent↗
PubMed2000

Epidermoid cyst involving the brain stem.

Brain stem epidermoid cysts are extremely rare. We describe an unusual case of prepontine epidermoid cyst with a large part of the tumour insinuating itself into the pons. Microsurgical total excision of tumour was done without producing any new neurological deficits. Cases reported in the literature either had high mortality/morbidity or were only subtotally removed. Relevant literature is reviewed.

Brain Diseases↗
PubMed2000

Rapid diagnosis of tuberculous meningitis by a dot-immunobinding assay.

In this study, a dot-immunobinding assay (Dot-Iba) was standardized to measure circulating antimycobacterial antibodies in the cerebrospinal fluid (CSF) specimens for the rapid laboratory diagnosis of tuberculous meningitis (TBM). Specific CSF-IgG antibody to Mycobacterium tuberculosis from a culture proven patient with TBM was isolated and coupled with activated Cynogen bromide-Sepharose 4B. Using an immunoabsorbent affinity chromatography, 14 kDa antigen present in the culture filtrates of M. tuberculosis was isolated and this antigen was used in the Dot-Iba, to quantitate specific antimycobacterial antibodies in CSF specimens. The Dot-Iba gave positive results in all the 5 culture proven patients with TBM and gave no false positive results in CSFs from patients with partially treated pyogenic meningitis. Dot-Iba developed in our laboratory is a simple, rapid and specific method and more importantly suited for the routine application in laboratories with limited resources.

Antibodies, Bacterial↗
PubMed2000

Fibrous dysplasia of the orbit in an infant.

Fibrous dysplasia is an idiopathic fibro-osseous lesion of the skeletal bones. These uncommon osseous lesions usually manifest within the first two decades of life. Its occurrence during infancy is extremely uncommon, and we describe here a case of fibrous dysplasia involving the orbit in a 9-month-old male child.

Craniotomy↗
PubMed2000

Significance of circulating immune complexes in myasthenia gravis.

In this study, circulating immune complexes (CICs) were isolated and characterized in the sera of myasthenia gravis (MG) patients with thymoma and MG patients without any thymic lesions. High titres of antistriational antibodies in the CICs were demonstrated by an indirect immunofluorescence (IF) method in 60 per cent (15/25) MG patients with thymoma. The CICs showed a steady decrease in these 15 patients during the post thymectomy period. Antistriational antibodies in the CICs of MG patients without thymic lesions were not detected by IF method. The results of this study emphasised the usefulness of estimation of CICs in the overall management of MG patients with thymoma.

Antigen-Antibody Complex↗
PubMed2000

Atypical meningioma: a clinicopathological analysis.

In this retrospective study, 382 operated cases of meningiomas were reviewed. 32 cases (8.3%) were histopathologically classified as atypical meningioma. The anatomical locations and histological features in all the thirty-two cases were correlated with their recurrence rates and biological behaviour. The overall recurrence rate for atypical meningioma within two years was 28% as compared to 9.3% in benign meningiomas. It is being emphasized that an accurate histopathological interpretation of atypical meningioma is essential for predicting the recurrence, biological behavior as well as post-operative management modalities.

Adult↗
PubMed1999

Expanding cyst following temporal lobectomy: an unusual complication of epilepsy surgery.

Following anterior temporal lobectomy performed to control intractable complex partial seizures (CPS), it is rare to find a symptomatic cyst at the lobectomy site causing increased intracranial pressure and neurological deterioration. We report a 24-year-old lady who underwent anterior temporal lobectomy with extended amygdalohippocampectomy for CPS of temporal lobe origin. Ten months following the procedure, she developed a large expanding cyst at the temporal lobectomy site manifesting with recurrence of CPS, progressive focal neurological deficit and increased intracranial pressure. The patient underwent a repeat craniotomy, decompression of the cyst along with wide excision of the wall and fenestration of the arachnoid membrane into the basal cisterns. Following the procedure, the features of increased intracranial pressure and focal neurological deficit promptly improved and her seizures became better controlled. Craniotomy and fenestration of a symptomatic iatrogenic cyst following temporal lobectomy results in clinical improvement, obviating the need for a permanent cystoperitoneal shunt.

Adult↗