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Biomedical subjects

S P Mehta

Publications and source records attributed to S P Mehta.

At least 19 recordsLinked to original sources
PubMed2001

Amyloid beta protein 1-40 and 1-42 levels in matched cerebrospinal fluid and plasma from patients with Alzheimer disease.

We quantitated amyloid beta proteins 1-40 (Abeta40) and 1-42 (Abeta42), and alpha1- antichymotrypsin (ACT) in matched cerebrospinal fluid (CSF) and plasma of 50 patients with probable Alzheimer disease, and analyzed the relationships with age, sex, Mini-Mental State Examination (MMSE), and apolipoprotein E phenotype. There was no relation between CSF Abeta40 and Abeta42 levels with those of plasma. CSF and plasma Abeta40 and Abeta42 levels showed no association with age, sex, and MMSE score. There was a significant correlation between CSF ACT and plasma ACT levels. The data suggest that plasma ACT crosses the blood-brain barrier. However, a lack of correlation between CSF Abeta40 and Abeta42 levels with those of plasma suggests that Abeta in CSF and plasma originates from different sources.

Aged↗
PubMed2000

Plasma and cerebrospinal fluid levels of amyloid beta proteins 1-40 and 1-42 in Alzheimer disease.

BACKGROUND: In brains with AD, Abeta is a major component of diffuse plaques. Previous reports showed that CSF Abeta42 levels were lower in patients with AD than in controls. Although studies showed higher plasma Abeta42 levels in familial AD, a recent report has indicated that plasma Abeta42 levels were similar in a sporadic AD group and controls. However, no information is published on plasma Abeta40 and Abeta42 levels in relation to Apo E genotype or severity of dementia in sporadic AD. OBJECTIVE: To examine plasma and cerebrospinal fluid (CSF) levels of amyloid beta protein 1-40 (Abeta40) and 1-42 (Abeta42) levels in patients with probable Alzheimer disease (AD) and elderly nondemented control subjects in relation to the apolipoprotein E (Apo E) genotype and dementia severity. SETTING: Two university medical centers. PATIENTS AND METHODS: Levels of Abeta40 and Abeta42 were measured in plasma from 78 patients with AD and 61 controls and in CSF from 36 patients with AD and 29 controls by means of a sandwich enzyme-linked immunosorbent assay. RESULTS: Mean plasma Abeta40 levels were higher in the AD group than in controls (P = .005), but there was substantial overlap; Abeta42 levels were similar between the groups. Levels of Abeta40 and Abeta42 showed no association with sex or Mini-Mental State Examination scores. There was a significant relationship between age and Abeta40 level in controls but not in the AD group. Levels of Abeta40 were higher in patients with AD with the Apo E epsilon4 allele than in controls (P<.01). Cerebrospinal fluid Abeta40 levels were similar in the AD group and controls. However, Abeta42 levels were lower in the AD group than in controls (P<.001). The levels showed no association with severity of dementia. CONCLUSIONS: Although mean plasma Abeta40 levels are elevated in sporadic AD and influenced by Apo E genotype, measurement of plasma Abeta40 levels is not useful to support the clinical diagnosis of AD. Lower levels of CSF Abeta42 in the AD group are consistent with previous studies.

Adult↗
PubMed1999

Differential fetal and maternal contributions to the cytokine milieu in a murine model of infection-induced preterm birth.

OBJECTIVE: The aim of the study was to determine the relative productions by maternal and fetal tissues of proinflammatory and anti-inflammatory cytokines in a murine model of infection-induced preterm delivery. STUDY DESIGN: The right uterine horns of CD-1 female mice at 14.5 days of a 19- to 20-day gestation were inoculated with either sterile media or live Escherichia coli. The concentrations of cytokines within uteri, placentas, membranes, and fetal lower body segments were determined by enzyme-linked immunosorbent assay at various times after inoculation. RESULTS: All infected tissues showed large, time-dependent increases in interleukin 1alpha, interleukin 1beta, and interleukin 6. These increases were maximal 13 hours after infection and were highest in uteri (15-60 times levels in uninfected tissues). Increases in tumor necrosis factor alpha and interleukin 1 receptor antagonist were much smaller (3 to 5 times) and were confined to the uterus. Although the uterus contained the greatest concentrations of interleukin 1alpha, interleukin 1beta, interleukin 6, and tumor necrosis factor alpha, fetal bodies and placentas contained the highest levels of interleukin 1 receptor antagonist. CONCLUSIONS: Time-dependent increases in maternal and fetal cytokines occurred after acute bacterial infection in this murine model. The fetus and placenta may be the most significant sources of the anti-inflammatory cytokine interleukin 1 receptor antagonist during pregnancy, whereas the uterus appears to be a more important source of interleukin 1, interleukin 6, and tumor necrosis factor alpha. Interleukin 1 receptor antagonist levels within uteri were insufficiently high to effectively inhibit interleukin 1 activity during infection.

Animals↗
PubMed1998

Increased plasma amyloid beta protein 1-42 levels in Down syndrome.

Amyloid beta protein 1-40 (A beta40) and A beta42 levels were quantitated in plasma from 43 persons with Down syndrome (DS; 26-68 years of age), 43 age-matched normal controls, and 19 non-DS mentally retarded (MR) persons (26-91 years of age) by using a sandwich enzyme linked immunosorbent assay. A beta40 levels were higher in DS and MR than controls, but were similar between DS and MR groups. A beta42 levels were higher in DS than controls or MR persons. The ratios of A beta42/A beta40 were higher in DS than controls or MR persons. The findings are consistent with those seen in DS brains.

Adult↗
PubMed1997

Increased levels of interleukin-1beta and soluble intercellular adhesion molecule-1 in cerebrospinal fluid of patients with subacute sclerosing panencephalitis.

Proinflammatory cytokines (interleukin [IL]-1beta, tumor necrosis factor [TNF]-alpha, and IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) were measured in paired cerebrospinal fluid (CSF) and serum samples from patients with subacute sclerosing panencephalitis (SSPE), multiple sclerosis (MS), or other neurologic diseases (OND) by ELISA. IL-1beta was significantly increased in CSF of the SSPE group compared with levels in the MS or OND group. IL-1beta CSF/serum ratios were higher in the SSPE than in the MS or OND group. TNF-alpha and IL-6 levels were similar in the 3 groups. CSF sICAM-1 was higher in the SSPE group than in the MS or OND group. sICAM-1 CSF/serum ratios were higher in the SSPE than the OND group. The increased CSF/serum ratios of IL-1beta and sICAM-1 in SSPE indicate synthesis of IL-1beta and sICAM-1 in the central nervous system and may be important in the pathogenesis of disease.

Adolescent↗
PubMed1993

Entamoeba histolytica cyst passers. Clinical profile and spontaneous eradication of infection.

The present study was carried out to examine whether Entamoeba histolytica cyst passers suffer from any parasite-related bowel symptoms and to assess the frequency of spontaneous eradication of this infection. The study was carried out in two parts. In part I, stool samples were collected at random from 3536 individuals living in rural communities around Delhi. E. histolytica was isolated by the culture technique in 345 (9.7%) subjects. There was no increase in the prevalence rate of bowel symptoms in the culture-positive compared to the culture-negative subjects. One hundred twenty-four (36%) of the culture-positive subjects agreed to take part in a longitudinal study; the subjects were left untreated and clinical assessment and stool examinations were carried out at three-month intervals. One hundred eighteen (95.2%) subjects had eradicated their parasite spontaneously at the end of one year; none developed any features of invasive amebiasis. Part II of the study was carried out on 625 patients attending our Gastroenterology Clinic. Positive cultures of E. histolytica were obtained from 99 (15.2%) patients. Again, there was no increase in the prevalence rate of bowel complaints in the culture-positive compared to the culture-negative subjects. Moreover, histological appearances of the rectal biopsy specimens were not significantly different between the two groups. Twenty-eight (28.2%) patients agreed to the longitudinal study and all eradicated the parasite spontaneously within five months; none developed any evidence of invasive amebiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Immunoglobulin G subclasses in older persons with Down syndrome.

IgG subclasses were measured in sera from 33 persons with Down syndrome (DS) (mean age 55 +/- 7 years) and 33 age- and sex-matched control individuals using a mouse monoclonal antibody based sandwich enzyme linked immunosorbent assay. Significantly higher levels of IgG1 and IgG3 and lower levels of IgG2 and IgG4 subclasses were found in the DS group compared to the control individuals. The higher levels of IgG1 and IgG3 subclasses found in DS persons were consistent with those seen in patients with autoimmune diseases and chronic viral infections; the lower levels of IgG2 and IgG4 subclasses were consistent with those seen in patients with recurrent infections. Our findings are similar to those reported in children with DS. We speculate that the subclass levels may have little or no relationship to the development of brain lesions typical of Alzheimer disease in older persons with DS. There were no significant differences between the levels of IgG subclasses of persons with DS showing signs of dementia of the Alzheimer type compared to those without such manifestations.

Adult↗
PubMed1992

Increased levels of beta 2-microglobulin, soluble interleukin-2 receptor, and soluble CD8 in patients with subacute sclerosing panencephalitis.

We measured beta 2-microglobulin (beta 2-M), soluble interleukin-2 receptor (sIL-2R), and soluble CD8 (sCD8) antigen levels in paired cerebrospinal fluid (CSF) and sera from patients with subacute sclerosing panencephalitis (SSPE), multiple sclerosis (MS), and other neurological diseases (OND) using enzyme-linked immunosorbent assay. beta 2-M was significantly increased in CSF of the SSPE group compared to the MS or the OND group. Similarly, beta 2-M in the MS versus OND group was significantly increased in CSF. Although serum levels of beta 2-M were similar in the three groups, the CSF/serum ratios were higher in SSPE versus the MS group and in the MS versus the OND group. Levels of sIL-2R and sCD8 were higher in SSPE CSF than OND CSF; however, there were no differences between levels in SSPE and MS CSF. The levels of sIL-2R were increased in SSPE sera compared to those of MS or the OND group, whereas levels of sCD8 in serum from the three groups were similar. The findings of increased CSF/serum ratio of beta 2-M and higher levels of serum sIL-2R and CSF sCD8 in SSPE patients are consistent with those seen in patients with acute and chronic viral infections. When the levels between the initial and follow-up CSF and serum samples from SSPE patients were compared, the data showed that CSF levels of sCD8 elevated during periods of clinical worsening and decreased during clinical improvement. In contrast, serum beta 2-M decreased during periods of worsening and increased during improvement. The measurement of serum beta 2-M and CSF sCD8 may be useful in SSPE patients as markers to monitor disease activity.

Adolescent↗
PubMed1989

Distribution of IgG subclasses in human colostrum and milk.

Immunoglobulin G (IgG) subclasses in human colostrum and milk were quantitated using mouse monoclonal antibodies specific for human IgG subclasses and an enzyme-linked immunosorbent assay (ELISA). The percentage of IgG1 was significantly increased and that of IgG2 was decreased in both colostrum and milk relative to the percentage distribution reported in healthy adult and maternal sera. Percentages of IgG3 and IgG4 in colostrum, milk and sera were similar. All IgG subclass concentrations decreased by 90% during the first week of lactation and remained constant thereafter. The possible antiviral role of high levels of IgG1 in colostrum and milk is discussed.

Age Factors↗
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↗
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↗
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↗
PubMed1984

Paraplegia.

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Adult↗