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Biomedical subjects

S Nagpal

Publications and source records attributed to S Nagpal.

66 records · Page 4Linked to original sources
PubMed1990

Detection of IgG, IgA, IgM and IgE in antibodies in invasive amoebiasis in endemic areas.

Entamoeba histolytica--specific serum IgG, IgA, IgM and IgE were assayed in cases of amoebiasis in an endemic area. Patient groups consisted of amoebic liver abscess (n = 18), pre abscess hepatic amoebiasis (n = 22) and amoebic colitis (n = 30). Control subjects comprised 26 asymptomatic cyst passers, 13 giardiasis cases, 20 typhoid patients and 24 non amoebic individuals. Serum IgG was assayed by ELISA: using a monoclonal anti IgG beta-galactosidase (IgG beta-gal) conjugate, a polyclonal avidin biotin horse radish peroxidase (AB-HRP) and a polyclonal anti IgG horse radish peroxidase (IgG HRP) conjugate. IgA and IgM were assayed by the beta-gal ELISA and IgE by AB-HRP. Diagnostically significant IgG and IgA while lower IgM and IgE levels were seen in extra intestinal cases. About 40% of suspected pre abscess hepatic amoebiasis cases were confirmed by antibody estimation. All isotype levels in most dysentery cases were in the range of the controls. Inter assay coefficient of variation and assay specificity/sensitivity are also discussed.

Animals↗
PubMed1989

Induction of allergen-specific IgE and IgG responses by anti-idiotypic antibodies.

In order to explore idiotypic, anti-idiotypic, and anti-anti-idiotypic responses to allergens, BALB/c mice were immunized with affinity-purified human idiotypic antibodies directed against a highly purified shrimp allergen. This resulted in the production of anti-idiotypic antibodies which were quantitated by using rabbit idiotypic antibodies raised against the same purified allergen. The mouse anti-idiotypic antibodies recognized shrimp-specific human idiotypic antibodies of the IgE isotype from 18 of 20 individuals, and IgG antibodies from 14 of 20 shrimp-sensitive patients. Immunization of BALB/c mice with affinity-purified, allergen-specific anti-idiotypic antibodies induced anti-allergen IgE and IgG responses in the absence of the allergen. This paper thus presents evidence that anti-idiotypic antibodies raised against allergen-specific idiotypic antibodies may substitute for the original allergen in the induction of allergen-specific idiotypic antibodies. The demonstration of shared idiotopes on IgG and IgE antibodies in the sera of shrimp-sensitive patients supports the use of allergen-specific anti-idiotypic antibodies as surrogate allergens.

Adult↗
PubMed1989

Mapping of two varicella-zoster virus-encoded genes that activate the expression of viral early and late genes.

A transient assay system was used to identify varicella-zoster virus (VZV)-encoded genes whose products are able to activate the expression of an early gene promoter, the thymidine kinase (tk) promoter, and a late gene promoter, and the glycoprotein I (gpI) promoter. Vero cells were cotransfected with individual cloned DNA fragments spanning the entire VZV genome and with the recombinant construct p1tkCAT which contained the chloramphenicol acetyl transferase (CAT) gene under the control of putative regulatory sequences. Five- to 20-fold increases in the expression p1tkCAT was observed in cotransfections with plasmids containing VZV open reading frame (ORF)4 (map location 0.02-0.03) or ORF62 (0.82-0.86). Expression of p68CAT (contains -682 to +222 bp relative to the AUG of gpI) was also enhanced by the products of ORF4 and ORF62. Synergy between ORF4 and ORF62 products was observed in the activation of p68CAT, resulting in a 22-fold increase in CAT activity. RNA analysis indicated that activation of these promoters was at the transcriptional level. A VZV-encoded "repressor" sequence, containing ORF60 and ORF61, was also identified which repressed expression of p1tkCAT and modulated its activation by ORF4 and ORF62.

Animals↗
PubMed1989

Surgical treatment for ductal adenocarcinoma of the pancreas.

A ten year community hospital experience of 124 patients with ductal adenocarcinoma of the pancreas proved at biopsy is reported. All patients underwent a celiotomy, and 94 per cent were observed until death. All of the patients were stratified by stage (I, 9 per cent; II, 30 per cent; III, 18 per cent, and IV, 43 per cent). Nine of the patients with Stage I disease underwent resection with a high postoperative mortality rate of 44 per cent and only one five year survivor. Fifty-nine patients with Stages II and III disease underwent biliary bypass with a low postoperative mortality rate of 2 per cent. Bypass of the common bile duct (N = 24) provided more permanent palliation against recurrent jaundice or cholangitis (p less than 0.05), but did not improve the survival time when compared with bypass of the gallbladder (N = 20). This was not true for those with Stage IV disease in whom recurrent jaundice did not develop in those with either bypass of the gallbladder or common duct. Adding prophylactic gastroenterostomy (GE) to biliary bypass (N = 25) conferred no survival benefit, but did protect against subsequent duodenal obstruction (p less than 0.05). Thirty-seven per cent of the 38 patients in whom a GE was not performed had duodenal obstruction develop. Adjuvant radiation and chemotherapy in 22 patients with unresectable Stages II and III disease resulted in a significant prolongation of survival time compared with 15 untreated patients in the control group (p less than 0.05). Fifty-one patients with Stage IV disease underwent biliary bypass or biopsy of the tumor resulting in a 14 per cent postoperative mortality rate and a median survival time of four months. Nine per cent of the 44 survivors with Stage IV disease lived at least one year. The implications of these findings to clinical practice are discussed.

Adult↗
PubMed1987

Identification of a shrimp-derived allergen as tRNA.

During an attempt to isolate shrimp allergens, evidence was obtained that shrimp ribonucleic acid was capable of eliciting a specific IgE response in man and an experimental animal model system. The shrimp ribonucleic acid was extracted from boiled whole shrimp (Peneaus indicus), and was isolated by salt precipitation and sequential chromatography over DEAE-Sephacel and BioGel P-100. The allergenic material was identified as a ribonucleic acid based on the following criteria: a maximal absorption at 258 nm, failure to stain positively with Coomassie Brilliant Blue on slab gel electrophoresis, positive staining with ethidium bromide, co-migration with yeast tRNA on submerged gel electrophoresis in 1.5% Agarose M, and sensitivity to ribonuclease T2 and 0.3 M NaOH. Treatment with protease did not alter its allergenic activity. The RNA was capable of binding allergen-specific IgE in sera from two shrimp-sensitive patients, as demonstrated by microELISA and solid-phase radioimmunoassay (SPRIA) using antigen-coated nitrocellulose filter paper discs and purified 125I-labeled goat anti-human IgE. RNA isolated from shrimp by a conventional tRNA isolation procedure also had the ability to specifically bind IgE in the sera of shrimp-sensitive patients. IgE antibodies to shrimp RNA did not recognize yeast tRNA or salmon testes DNA, and were not detected in sera of other subjects. The shrimp-derived RNA was further able to induce a reaginic response in mice. A combination of in vitro aminoacylation of shrimp tRNA and SPRIA resulted in the identification of the allergenic tRNA as tRNA(Tyr) and tRNA(Arg). Thus, shrimp tRNA is capable of inducing a specific IgE response in man.

Adult↗
PubMedDate not supplied

Serum lipoperoxide levels in pregnancy induced hypertension.

With present day awareness of role and toxicity of lipid peroxides, serum levels of lipoperoxides have been investigated in forty pregnancy induced hypertension (PIH) subjects, before and after antihypertensive drug therapy, using full term normotensive patients as control. PIH subjects demonstrated highly significant elevated serum levels of lipoperoxides (mean 3.60 nmol/ml) in comparison (mean 2.15 nmol/ml) with full term normotensive subjects. At post-partum PIH subjects following antihypertensive drug therapy and becoming normotensive showed highly significant fall in serum lipoperoxide (mean level 2.27 nmol/ml). Full term normotensive subjects at post-partum also demonstrated the same pattern. However, observed levels of serum lipoperoxide in PIH subjects at post-partum even after becoming normotensive following treatment were found to be significantly elevated when compared with those of full term normotensives at post-partum (mean level 1.94 nmol/ml). It is felt that monitoring of serum lipoperoxide level can serve as one of the useful parameters in PIH subjects.

Adult↗