Browsing by Author "Reuben, S"
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Item A comparative evaluation of Dot immunobinding assay (Dot-Iba) and polymerase chain reaction (PCR) for the laboratory diagnosis of tuberculous meningitis(DIAGNOSTIC MICROBIOLOGY AND INFECTIOUS DISEASE, 2002)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-lba gave positive results, while PCR yielded positive results only in six patients. The overall sensitivities of Dot-lba and PCR in 37 patients with culture negative (probable) TBM were 75.67% and 40.5% respectively. Dot-lba, in contrast to PCR is a rapid and relatively easier method. More importantly, Dot-lba is suitable for the routine application for the laboratory diagnosis of TBM and therefore best suited to laboratories in the developing world. (C) 2002 Elsevier Science Inc. All rights reserved.Item A dot-immunobinding assay (dot-Iba) for rapid diagnosis of pulmonary tuberculosis.(Indian journal of experimental biology, 2001)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.Item Circulating tumour necrosis factor alpha & soluble TNF receptors in patients with Guillain-Barre syndrome(INDIAN JOURNAL OF MEDICAL RESEARCH, 2003)Background & objectives: Tumour necrosis factor-alpha (TNF-alpha) is regarded as one of the immune factors that can induce demyelination of peripheral nerves in patients with Guillian-Barre syndrome (GBS). This present study was undertaken to find out the role of TNF-alpha and soluble TNF receptors in the pathogenesis of GBS; and to study the effect of intravenous immunoglobulin (ivlg) therapy on the serum TNF-a and soluble TNF receptors in patients with GBS.Methods: Thirty six patients with GBS in progressive stages of motor weakness were included in this study. The serum TNF-alpha and soluble TNF receptors (TNF-RI, TNF-RII) were measured in the serum samples of these patients before and after ivIg therapy by a sandwich ELISA.Results: Of the 36 patients with GBS, 26 (72.2%) showed elevated serum TNF-alpha levels prior to ivIg therapy. Following a complete course of ivIg therapy there was a progressive decrease in the serum TNF-alpha concentrations in these 26 patients. On the other hand, the soluble TNF receptors, particularly TNF-RII showed an increase in the serum of GBS patients following ivIg therapy.Interpretation & conclusion: The results indicate that ivIg reduces the serum TNF-alpha. concentrations in the GBS patients having elevated levels prior to ivlg therapy. Elevated serum levels of soluble TNF receptors following ivIg therapy may play a protective role by inhibiting the demyelinating effect of TNF-alpha in the peripheral nerves of patients with GBS.Item Immunocytochemical method for early laboratory diagnosis of tuberculous meningitis(CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY, 2002)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.Item Immunocytochemical method for the diagnosis of tuberculous meningitis.(JOURNAL OF NEUROPATHOLOGY AND EXPERIMENTAL NEUROLOGY, 2004) Radhakrishnan, VV; George, SM; Reuben, S; Nair, MItem Intravenous immunoglobulin reduces serum tumor necrosis factor alpha in patients with Guillain-Barre Syndrome(NEUROLOGY INDIA, 2003)Background: Tumor necrosis factor a TNF-alpha has a possible role in the pathogenesis of the Guillain-Barre'syndrome (GBS). Alms: To study the effect of intravenous immunoglobulin (IVIg) on serum TNF-alpha concentrations in patients with GBS. Material and Methods: The effect of IVIg on TNF-alpha was evaluated in 36 patients with GBS. Serum TNF-alpha concentration was measured by enzyme-linked immunosorbent assay (ELISA). The sera of 22 (61%) patients with GBS showed elevated concentrations of TNFalpha (35-182 pg/ml) and these sera were individually incubated in vitro with IVIg (0.25mg/ml) at 370 degreesC for 24 hours. Results: The serum TNF-alpha concentrations in the 22 GBS patients with elevated levels showed a steady decline (60.34-19.78 pg/ml) following incubation with IVIg. These 22 patients also received IVIg therapy, and serum TNF-alpha concentrations showed a significant decline (65.5-9.75 pg/ml) at the end of the therapy. At the time of discharge from the hospital, there was a positive correlation between neurological recovery and decline in TNF-alpha concentrations in these 22 GBS patients. Conclusions: The results of this study indicate that elevated levels of TNF-alpha occur in a proportion of patients with GBS and in these patients elevated serum TNF-alpha levels decline with IVIg therapy.Item Serum tumor necrosis factor-alpha in Guillain-Barre syndrome and its relation to plasma exchange(NEUROLOGIST, 2002)BACKGROUND- To correlate the serum tumor necrosis factor-alpha (TNFalpha) concentrations before, during and following plasma exchange in patients with Guillain-Barre syndrome (GBS). In this prospective study, 21 GBS patients were selected. Patients in clinical stages III to V were subjected to plasma exchange. The control group included equal numbers of age-matched patients with other neurological diseases and healthy voluntary blood donors. A sandwich ELISA method was applied to estimate serum TNFalpha concentrations in test and control groups.REVIEW SUMMARY-Twelve GBS patients had elevated serum TNFalpha levels that ranged between 74 and 182 pg/mL. All 12 GBS patients showed a steady decrease in the TNFalpha concentration following plasma exchange and also showed a positive correlation with neurological recovery.CONCLUSIONS- We conclude that serum TNFalpha concentrations are elevated in 57.1 % of GBS patients and TNFalpha level decreases following plasma exchange.Item Serum tumour necrosis factor-alpha and soluble tumour necrosis factor receptors levels in patients with Guillain-Barre syndrome(ACTA NEUROLOGICA SCANDINAVICA, 2004)Objectives - To estimate the serum concentrations of Tumour Necrosis Factor alpha (TNF-alpha) and soluble TNF receptors (s TNF-RI and TNF-RII) in patients with Guillain-Barre syndrome (GBS), before and after treatment. Material and methods - The serum TNF-alpha and the soluble TNF receptors concentrations were measured by a sandwich enzyme-linked immunosorbent assay (ELISA) in 47 patients with GBS before and after the treatment - IVI therapy (n = 26); Plasma Exchange (n = 21). Results- At the time of admission, the serum TNF-alpha concentrations were elevated (32.5-182.5 pg/ml) in 41/47 GBS patients (87.2%). Following the treatment (IVIG or PE), there was a significant decrease in the serum TNF-alpha concentrations (8.5-58.5 pg/ml) in these 41 GBS patients. The soluble TNF receptors, particularly sTNF-RII concentrations were significantly increased in GBS patients treated by IVIG therapy. Conclusions - The results of this indicated that (a) Elevated serum concentrations of TNF-alpha showed a positive correlation with the disease severity in patients with GBS. (b) The decrease in the serum TNF-alpha and increase in the serum soluble TNF receptors, particularly sTNF-RII showed a positive correlation with the neurological recovery in GBB patients following treatment.Item Significance of serum antibody to GD1b ganglioside in patients with Guillain-Barre syndrome(INDIAN JOURNAL OF MEDICAL RESEARCH, 2001)Background & objectives: The precise etiological factors in Guillain-Barre 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 land PE decreases the anti GD1b antibody titers in these patients.