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Biomedical subjects

P V Niphadkar

Publications and source records attributed to P V Niphadkar.

7 recordsLinked to original sources
PubMed2005

Interleukin-10 promoter polymorphisms and atopic asthma in North Indians.

BACKGROUND: IL-10 is an anti-inflammatory cytokine primarily produced by monocytes and macrophages and plays a key role in asthma. IL10 gene, present in chromosome 1q31-q32, is regulated primarily by transcription and its expression is found to be lower in asthmatics. Earlier studies in diverse populations have identified several promoter polymorphisms. However, no study has been carried out in a genetically untapped large population from the Indian Subcontinent. OBJECTIVE: To investigate the association of the IL10 promoter polymorphisms and asthma in the North Indian population. METHODS: The association study was conducted in a case-control as well as in a family-based design. Polymorphism at -1082 A/G, -819 C/T and -592 C/A nucleotides were genotyped in ethnically matched unrelated patients (N=272), unrelated controls (N=307) and nuclear families (N=164). RESULTS: A suggestive evidence of association was obtained for -1082 A/G polymorphism at the level of alleles and genotypes with asthma in the case-control study (P=0.03). A three-locus haplotype (ATA) was found to be more in asthmatics than in control individuals (P=0.0085). On the other hand, a novel haplotype ATC was found to be more in controls than in asthmatics (P=0.012). These results were further tested in a family-based study. A deviation of transmission was observed for the -1082 A/G polymorphism (P=0.003). The ATA haplotype showed a preferential transmission in asthmatics (P=0.03), while the GCC and a novel ATC haplotype showed preferential non-transmission in asthmatic individuals (P=0.03 and 0.001, respectively). CONCLUSIONS: Using both case-control and family studies, we provide suggestive evidence that the ATA haplotype is positively, whereas GCC and a novel ATC haplotypes of IL10 gene are negatively associated with asthma in Indian population. Our results are interesting enough as to intensify further research to elucidate the functional significance of these single-nucleotide polymorphisms and haplotypes in asthma pathogenesis.

Adult↗
PubMed2004

A_16_C haplotype in the FcepsilonRIbeta gene confers a higher risk for atopic asthma in the Indian population.

We conducted a case-control study aimed at identifying polymorphisms and haplotypes in the FcepsilonRIbeta gene associated with asthma and its associated phenotypes such as serum IgE levels. A G/A polymorphism in intron 2, a (CA)n repeat polymorphism in intron 5, and a C/T polymorphism in 3'-UTR, encompassing a length of 8.74 Kb, were genotyped, and haplotypes were generated for unrelated patients and healthy volunteers in two independent cohorts. A significant association was observed at the level of alleles and genotypes studied with asthma independently in the two cohorts (p < 0.05). A change in CC_AA genotype combination to a non-CC_AA genotype was associated with reduced risk for asthma. Interestingly, a three-locus haplotype, A_16_C, was found to be significantly associated with asthma (p = 10(-5) in cohort A and p = 0.004 in cohort B). On the other hand, the haplotype G_18_T was found to be negatively associated with asthma (p = 0.007 in cohort A and p = 0.0004 in cohort B). This is the first study identifying a haplotype A_16_C that predisposes individuals to asthma in the Indian population.

Adolescent↗
PubMed2001

Chickpea: a major food allergen in the Indian subcontinent and its clinical and immunochemical correlation.

BACKGROUND: The food allergy pattern of a country is influenced by the foods most commonly consumed. In India, the majority of the population consumes a vegetarian diet made up of pulse (legumes), cereals, and vegetables. In contrast to many western countries, chickpea preparations are consumed in large quantities in India. This study reports for the first time chickpea hypersensitivity reactions diagnosed with in vivo and in vitro tests. METHODS: One thousand four hundred patients visiting allergy clinics were randomly selected for the study. Those patients reporting an allergic reaction on every occasion after eating chickpea were considered history-positive. Modified prick tests were performed with chickpea and other members of the legume family on all these patients. The claims of the history-positive patients were verified with double-blind, placebo-controlled food challenges (DBPCFCs). Proteins in chickpea extracts were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred on nitrocellulose paper. Serum specimens from history-positive patients were analyzed by immunoblot and ELISA. To verify the IgE specificity, an immunoblot inhibition assay was also performed. RESULTS: Of the 1,400 patients screened, 142 patients were history-positive to some food and 59 of these implicated chickpeas. Forty-one patients were skin test-positive and 31 were DBPCFC-positive for chickpea. The predominant symptoms after chickpea ingestion were respiratory. The ELISA results did not correlate well with the DBPCFC results; however, the skin test results correlated with DBPCFC in 75% of patients. Immunoblot analysis showed that 70, 64, 35, and 26 kD proteins were major allergens. CONCLUSIONS: Chickpea is an important source of allergen that can cause IgE-mediated hypersensitivity reactions ranging from rhinitis to anaphylaxis.

Adolescent↗
PubMed2001

Psocoptera spp. (book louse): a new major household allergen in Mumbai.

BACKGROUND: Exposure and sensitization to indoor allergens of house dust mites and insects is well established. However, there are no reports on the allergenicity of Psocoptera spp. (book louse). These insects are known to inhabit various terrestrial habitats such as tree bark (bark lice), old papers, books, stored food products, etc and gain entry into human dwellings through these modes. They have the potential to sensitize individuals with an occupational exposure to them. OBJECTIVE: Our objective is to use clinical and immunologic techniques to evaluate the extent of sensitization to Psocoptera in patients with nasobronchial allergy. We also have the objective to determine the extent of Psocoptera infestation in houses in Mumbai (Bombay). METHODS: An entomologic analysis of dust samples in houses in Mumbai was carried out and Psocoptera found in these samples was mass-cultured. Two hundred patients were checked for allergy to the Psocoptera extracts using skin test. Total IgE and specific IgE to Psocoptera in sera from Psocopotera-sensitive patients' sera were estimated by enzyme immunoassay. IgE-binding proteins of Psocoptera were determined by immunoblotting experiments. RESULTS: Among the 75 house dust samples from Mumbai analyzed for the presence of Psocoptera, 25% were found to be infested by Psocoptera. Strong skin sensitivity to Psocoptera was found in 20% of patients. Total IgE levels >150 IU/mL were found in these patients and high levels of specific IgE to Psocoptera were detected by ELISA. Immunoblot analysis revealed 67, 59, 43, and 27 kD proteins as major allergens of Psocoptera. CONCLUSIONS: Psocoptera is an important allergen in Mumbai as it causes IgE mediated responses in 20% of the allergic population studied.

Air Pollution, Indoor↗
PubMed1997

Allergy to fenugreek (Trigonella foenum graecum).

BACKGROUND: Allergic reactions after consumption of spices are well-known. In Asia, fenugreek seeds are consumed as spices and also as medicines. Literature survey carried out does not reveal reports of allergic reactions to fenugreek. In our survey carried out on patients with food allergy, we found two cases of severe allergy to fenugreek. METHODS: We report here two cases of immediate allergy following ingestion, inhalation, and external application of fenugreek seed powder. In the first case, inhalation of the fenugreek seed powder resulted in rhinorrhea, wheezing, and fainting. The second case was of a patient with chronic asthma who developed numbness of head, facial angioedema, and wheezing after application of fenugreek paste to her scalp as a treatment for dandruff. Skin scratch test was performed with fenugreek and other members of the Leguminosae family as fenugreek also belongs to Leguminosae. Objective evidence of the reaction was obtained by conducting double-blind placebo-controlled challenges (DBPCFC). For detecting IgE binding by immunoblotting method, the proteins of the fenugreek extract were resolved using sodium dodecyl sulphate polyacrylamide gel electrophoresis. RESULTS: Skin scratch tests for the patients revealed strong sensitivity to fenugreek and chickpeas. None of the controls showed such response with fenugreek extract. During DBPCFC, both patients showed > 20% drop in peak flow rate after consumption of fenugreek and chickpea. Immunoblots demonstrated binding of specific IgE from the patients' sera with the protein from extracts between 20 kD to 70 kD bands. CONCLUSION: This case report has enlarged the list of food allergens with the addition of fenugreek.

Adult↗
PubMed1989

Immunochemical characterization of cocos nucifera pollen.

The Cocos nucifera pollen, as one of the sources of allergen responsible for immediate hypersensitivity reaction, was confirmed by skin prick test, bronchial provocation test, and RAST. The whole pollen extract (WPE) of C. nucifera was fractionated by combination of gel filtration and ion-exchange columns with fast protein liquid chromatography (Pharmacia, Uppsala, Sweden). Three protein peaks designated Cocos II, Cocos VI, and Cocos VII exhibited allergenic properties, as tested by skin prick test, direct IgE ELISA, bronchial provocation test, and immunoblot analysis. In RAST inhibition, Cocos IIa (a high-molecular-weight protein) obtained by fractionation of Cocos II on Mono Q column (fast protein liquid chromatography) (Pharmacia) was found to be the most potent allergen in Cocos WPE, followed by Cocos VI and Cocos VII, which are low-molecular-weight proteins. The reference patterns of Cocos WPE on crossed immunoelectrophoresis and thin-layer isoelectric focusing were established for future standardization of Cocos WPE to be used in the diagnosis and immunotherapy of allergic patients.

Allergens↗