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Biomedical subjects

P D Mehta

Publications and source records attributed to P D Mehta.

At least 73 records · Page 4Linked to original sources
PubMed1987

Specificity of oligoclonal IgG bands against myelin proteins in chronic relapsing EAE in guinea pigs.

We showed previously by using imprint electroimmunofixation that the oligoclonal IgG in sera and CSF from chronic relapsing EAE in guinea pigs were specific to spinal cord and Mycobacterium tuberculosis. We now show that most oligoclonal IgG bands are directed predominantly against isolated myelin basic protein (MBP). Activity to the latter could be removed from sera or CSF by absorption with MBP but not with histone or lysozyme. The oligoclonal IgG reacted weakly with isolated proteolipid apoprotein, and lacked reactivity to myelin-associated glycoprotein. When the oligoclonal IgG activity to myelin proteins was removed from the sera by absorption with a preparation of delipidated myelin before imprint electroimmunofixation, a few bands in some sera still reacted with whole spinal cord homogenate. These results indicate that, in some sera, a part of the oligoclonal IgG was directed against non-myelin proteins or lipids. In contrast to chronic relapsing EAE, CSF oligoclonal IgG from patients with multiple sclerosis showed no reactivity against human brain homogenate, whole myelin, delipidated myelin, and MBP in imprint electroimmunofixation.

Animals↗
PubMed1987

Quantitation of IgG and albumin in CSF and serum from multiple sclerosis patients by enzyme-linked immunosorbent assay.

Immunoglobulin G (IgG) and albumin from unconcentrated cerebrospinal fluid (CSF) and serum of patients with multiple sclerosis (MS) and non-MS controls were quantitated using enzyme-linked immunosorbent assay (ELISA). The IgG levels, IgG/albumin ratios and IgG indexes were significantly increased in CSF of MS patients compared to those of non-MS controls. The method is sensitive, rapid and reproducible and can be applied to routine laboratory use for quantitation of IgG and albumin in unconcentrated CSF from humans as well as in experimental animals used as models for demyelinating diseases.

Albumins↗
PubMed1986

Oligoclonal immunoglobulin bands in cerebrospinal fluid of a patient with lymphocytic choriomeningitis.

We describe a patient with meningitis caused by lymphocytic choriomeningitis virus. Oligoclonal IgG bands were found in the patient's cerebrospinal fluid during acute and convalescent stages of the illness, and results of liver function tests were abnormal. Acute attacks of lymphocytic choriomeningitis virus infection in humans can be added to the list of diseases associated with cerebrospinal fluid oligoclonal IgG.

Adult↗
PubMed1986

Detection of oligoclonal IgG bands in unconcentrated CSF by isoelectric focusing in agarose gel and silver staining.

We analyzed 102 unconcentrated cerebrospinal fluids from a variety of neurologic diseases for oligoclonal IgG bands by isoelectric focusing in agarose gel followed by staining with silver. Ten to 12 microliter of cerebrospinal fluid containing 0.4-0.8 microgram of IgG was found to be optimum. Cerebrospinal fluid from 38 of 40 patients with clinically definite multiple sclerosis, 6 of 9 with suspected multiple sclerosis and 8 of 53 patients with other neurologic diseases had oligoclonal IgG bands by IEF in agarose followed by immunofixation. The commercial system employed here is a simple sensitive and rapid method for detection of oligoclonal bands in unconcentrated cerebrospinal fluid of patients with multiple sclerosis.

Electrophoresis, Agar Gel↗
PubMed1986

Isoelectric focusing and two-dimensional gel electrophoresis in plasma and cerebrospinal fluid from patients with dementia.

IgG profiles of cerebrospinal fluid (CSF) and plasma from patients with Alzheimer's disease/senile dementia of Alzheimer type, multi-infarct dementia and aged nondemented individuals were analyzed using isoelectric focusing (IEF) followed by immunofixation and high resolution two-dimensional polyacrylamide gel electrophoresis (PAGE). The IEF profiles of plasma and CSF in patients with dementia were diffuse and lacked oligoclonal bands and were identical to those of nondemented individuals. The investigation of plasma and CSF by two-dimensional PAGE did not reveal any specific protein pattern in the demented individuals compared to the controls.

Adult↗
PubMed1985

Chronic relapsing EAE in guinea pigs: IgG index and oligoclonal bands in cerebrospinal fluid and sera.

IgG and albumin levels were quantitated in cerebrospinal fluid (CSF) and sera from chronic relapsing (R)-EAE animals using the enzyme linked immunosorbent assay. The animals showed increased CSF IgG compared to that of age-matched animals injected with complete Freund's adjuvant. However, the CSF IgG index suggested no significant increase in IgG synthesis within the central nervous system of R-EAE animals. Matching CSF and sera from R-EAE animals, when compared in immunofixation after isoelectric focusing, showed identical oligoclonal IgG band patterns. Although the clinical and morphologic findings in R-EAE are similar to those seen in multiple sclerosis, the site of IgG synthesis in these two diseases appears to be different.

Albumins↗
PubMed1985

Specificity of oligoclonal IgG bands in sera from chronic relapsing experimental allergic encephalomyelitis guinea pigs.

The specificity of oligoclonal IgG in sera from chronic relapsing EAE guinea pigs was determined by using imprint electroimmunofixation. The response of oligoclonal IgG to spinal cord and Mycobacterium tuberculosis appeared to be equal in animals sacrificed during first remission and in those sacrificed after recovery from acute EAE. In contrast, in animals sacrificed during or after the first relapse, the oligoclonal IgG seems to be directed predominantly against spinal cord. In imprint electroimmunofixation, the oligoclonal IgG specific to spinal cord did not react with guinea pig liver and kidney. In addition, activity to spinal cord could be removed from sera by absorption with spinal cord but not with kidney or liver.

Animals↗
PubMed1985

Measles virus encephalitis in ferrets as a model for subacute sclerosing panencephalitis.

Young adult ferrets were used as experimental animals to study subacute sclerosing panencephalitis (SSPE). When cells infected with cell-associated measles virus strains isolated from SSPE patients were inoculated intracerebrally (i.c.) into ferrets, they developed an acute encephalitis and died within 1 to 3 weeks without detectable antibody formation. Immunization with live measles vaccine 5 weeks before i.c. inoculation changed the course of the infection in about 50% of the ferrets. These animals developed a subacute encephalitis within weeks or months after inoculation. Cell-associated measles virus was isolated from their brains and high measles antibody titers were found in their sera, comparable to those in sera of SSPE patients. Measles virus specific immunoglobulins (IgG) were present in their brains and determination of IgG/albumin ratios indicated that antibodies were synthesized in the brain in response to the persistent measles virus infection. Measles specific oligoclonal IgG bands were found in the sera and spinal fluids of these animals. Therefore, subacute ferret encephalitis has virological and immunological characteristics in common with SSPE, indicating that it may serve as a model for the human disease. Other animal models of SSPE are described briefly.

Animals↗
PubMed1985

Isoelectric focusing and immunofixation of cerebrospinal fluid oligoclonal IgG in neurological disorders.

Coded samples of cerebrospinal fluid (CSF) from 112 patients with a variety of neurologic disorders were investigated for oligoclonal IgG bands by isoelectric focusing followed by immunofixation. All 16 patients with probable multiple sclerosis had oligoclonal bands. All four patients with paraneoplastic syndromes having multifocal nervous system involvement also had bands, whereas five patients with lupus, three having multifocal nervous system involvement, did not show any oligoclonal bands in the CSF. This technique is highly sensitive in detecting bands in MS, whereas other disorders that produce demyelination showed various levels of sensitivity.

Antibodies↗
PubMed1984

Absence of oligoclonal IgA in CSF and serum of multiple sclerosis patients.

CSF and serum from patients with MS and other neurologic diseases were analyzed by isoelectric focusing (IEF) in polyacrylamide gel and immunofixation with specific anti human IgA sera. The IgA band patterns seen in pH 4.5-6.0 region were rather diffuse and lacked oligoclonal feature.

Complement Fixation Tests↗
PubMed1984

Silver staining of unconcentrated cerebrospinal fluid in agarose gel (Panagel) electrophoresis.

We subjected cerebrospinal fluid (CSF) from 20 patients with multiple sclerosis and 20 patients with other neurological diseases to agarose gel ( Panagel ) electrophoresis followed by staining with silver. Ten microliters of unconcentrated CSF from multiple sclerosis patients containing 0.4 to 0.8 microgram of immunoglobulin G was found to be optimum for detection of oligoclonal IgG bands, so identified by immunofixation. The band patterns for unconcentrated CSF stained with silver were almost identical to those for the same CSF concentrated 40-fold and stained with Coomassie Brilliant Blue. Silver staining thus enables the clinical laboratory to electrophorese unconcentrated CSF on commercially prepared ( Panagel ) plates.

Electrophoresis, Agar Gel↗
PubMed1983

Presence of oligoclonal immunoglobulin G bands and lack of matrix protein antibodies in cerebrospinal fluids and sera of ferrets with measles virus encephalitis.

Young adult ferrets were immunized with measles vaccine and 5 to 6 weeks later inoculated intracerebrally with Vero cells persistently infected with cell-associated strain D.R. of measles virus isolated from a patient with subacute sclerosing panencephalitis. Of nine ferrets which survived the infection for 3 weeks or longer, five showed neurological signs. At the time of death they had widespread inflammation in their brains, and cell-associated virus was isolated from three ferrets sacrificed from 5 weeks to 7 months after inoculation. Four ferrets did not develop clinical signs, but two of these had mild inflammation in the brain 7 months and 2 1/2 years after inoculation, respectively. Cerebrospinal fluids drawn by cisternal puncture from infected ferrets at the time of sacrifice had neutralizing titers against measles virus similar to the titers found in sera, but antibody against the measles virus matrix protein was not detectable. Cerebrospinal fluid showed increased immunoglobulin G (IgG) and had distinct measles virus-specific oligoclonal IgG bands. The intensity of the bands correlated with the neutralizing titers of the fluids. These results confirm and extend earlier findings and indicate that persistent measles virus infection in ferrets is similar to human subacute sclerosing panencephalitis and can be used to study certain aspects of persistent brain infections leading to subacute encephalitis.

Animals↗
PubMed1982

Light-chain profiles in sera from patients with subacute sclerosing panencephalitis.

Sera from 2 subacute sclerosing panencephalitis (SSPE) patients were absorbed with a concentrated preparation of measles virus. Measles-specific IgG was eluted from the precipitates containing measles antigen-antibody complex. These IgGs, when subjected to immunofixation after isoelectric focusing showed a number of oligoclonal bands with one type of light-(L) chain. In urea polyacrylamide gel electrophoresis, the reduced and alkylated measles-specific IgG showed 1-3 homogeneous L-chain bands, whereas IgG isolated from unabsorbed sera and IgG isolated from supernatants of SSPE sera after absorption with measles virus showed a diffuse L-chain band. It can be concluded that in SSPE, measles virus is responsible for the synthesis of L-chain with restricted heterogeneity.

Animals↗