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D H Shah

Publications and source records attributed to D H Shah.

15 recordsLinked to original sources
PubMed1992

Monoclonal antibodies to human thyroglobulin: evaluation of immunoreactivity.

We have earlier reported production and characterization of monoclonal antibodies (MAbs) to human thyroglobulin (h-tg). In the present study H10 I MAb was evaluated for its immunoreactivity towards different forms of tg and various human thyroid tumours. The specificity of H10 I MAb was validated by the absence of cross reaction with tri-iodothyronine (T3) Thyroxine (T4) and human gamma globulins. Sodium-dodicyl-sulphate polyacrylamide gel electrophoresed (SDS-PAGE) immunoblot of h-tg on the nitrocellulose membrane revealed multiple immunoreactive bands on reaction with polyclonal antibody (PAb) in comparison with total lack of reactivity with H10 I MAb. The absence of immunoreactivity of H10 I MAb was demonstrated with SDS treated, Dithiothreitol (DT) treated and heat denatured tg using dot immunobinding technique. However, the H10 I MAb was able to react with tg treated with unfolding agents such as urea and guanidine hydrochloride. All the treated forms of tg were equally recognized by PAb. The immunoreactivity of the oxidized/reduced tg towards H10 I MAb was markedly reduced (60.0%) as compared to that obtained with native tg. It appears that H10 I MAb is directed towards conformational epitope involving sulphydryl bonds. Immunohistochemically, a comparable immunoreactivity between PAb and MAb was observed with normal thyroid tissues, follicular thyroid tissues, Hurthle cell carcinoma tissues and poorly differentiated thyroid tumor tissues using immunoperoxidase staining. The sections from papillary carcinoma tissue (thyroid as well as metastatic lymph node) exhibited intense immunoreactivity with PAb. Thyroglobulin present on these sections was not recognized by H10 I MAb. Nonetheless, H10 I MAb was able to detect tg in follicular differentiation wherever present. The absence of immunoreactivity of H10 I MAb in papillary carcinoma strongly suggests that this neoplasm produces tg which is antigenically different from the protein present in the normal tissue. The reactivity of H10 I MAb with metastatic lymph node of an unknown primary origin suggests its usefulness in the identification of prevalent metastasis of differentiated thyroid carcinoma other than papillary type.

Adenocarcinoma↗
PubMed1992

A simple radioassay for detection of antithyroglobulin autoantibodies.

Radioassay technique for detection of anti-thyroglobulin autoantibodies (ATA) in serum samples using protein-A rich Staphylococcus aureus as an immune complex separating agent was comparable (r = 0.99; n = 42; P < 0.001) to that evaluated with anti-human gammaglobulin (AHGG). The inter- and intra-assay coefficient of variations were lower (7.4 and 2.2% respectively) using Staph. aureus as compared to that observed with AHGG (10.4 and 4.7% respectively). A highly significant correlation was observed (r = 0.53; n = 71; P < 0.001) between per cent bound radiolabel thyroglobulin in radioassay and log reciprocal titre of ATA by haemagglutination method. Radioassay scored more number of positive sera as compared to haemagglutination method for normal controls (6 vs 1; n = 46) and patients of thyroid diseases (151 vs 70; n = 238). Due to the relatively poor stability of tracer on storage larger inter-assay coefficient of variations were observed with the radiolabelled preparations older than 10-12 days. The radioassay method evaluated is sensitive, reproducible and useful in detecting presence of anti-thyroglobulin autoantibodies.

Autoantibodies↗
PubMed1992

An immunoradiometric assay for measurement of serum thyroglobulin.

A two-site immunoradiometric assay (IRMA) for estimation of serum thyroglobulin (tg) is optimized using partially purified rabbit anti-tg antibodies (ammonium sulphate precipitated) as a solid phase antibody and affinity purified 125I labeled anti-tg antibodies as a tracer. The IRMA correlated well (r = 0.93, n = 200, P < 0.001) with conventional radioimmunoassay (RIA). The inter- and intra-assay coefficient of variation were comparable for both methods. The IRMA method gave a superior sensitivity and working range (2 ng/ml, 3-1000 ng/ml) as compared to that of RIA method (6 ng/ml, 9-500 ng/ml). Using IRMA the total incubation time was curtailed to 4 h as compared to 90 h required for conventional RIA. The shelf-life of tracer antibody used in IRMA was much longer (3 months) as compared to tracer tg (3-4 wk) used in RIA. The optimized IRMA for quantitation of serum tg has superior assay characteristics as compared to RIA.

Humans↗
PubMed1992

Filter paper blood spot test for detection of anti-ND-BSA antibodies in school children.

For identifying individuals at 'high risk' for developing leprosy, a simplified technique of collection of blood samples on filter paper for detection of anti -ND-BSA antibodies, was optimised. Anti-ND-BSA antibody reactivity on the filter paper was lost on storage at room temperature, but was stable at least for a period of 8 wk at lower temperature. Among the 1495 children screened, 166 (11.1%) were lepromin negative and 122 (8.2%) positive for anti-ND-BSA antibody. In the first phase, 7 of 871 children followed up for 2 yr developed leprosy, while in the second phase 2 of 624 children followed-up for 9 yr developed leprosy. The positivity and negativity of anti-ND-BSA antibodies and lepromin in these I children indicate that the positive status for anti-ND-BSA antibodies has a better predictive value than negative lepromin reactivity. Measurement of anti-ND-BSA antibodies was also of value for monitoring the efficacy of therapy and course of the disease. Extrapolation of the two tests to the total population of children evaluated showed that an individual with negative lepromin reactivity along with presence of anti-ND-BSA antibodies is at a higher risk for developing leprosy than those who have both the tests normal. Lepromin reactivity alone was not of much value for the prediction for development of the disease. However, the presence of anti-ND-BSA antibody was a better indicator for the development of the disease. The probability of developing leprosy in a child with any one of the tests abnormal was higher as compared to a child having all the tests normal.

Adolescent↗
PubMed1991

Additional evidence for functional subclassification of alpha-2 adrenoceptors based on a new selective antagonist, SK&F 104856.

SK&F 104856 (2-vinyl-7-chloro-3,4,5,6-tetrahydro-4-methyl-thieno[4,3,2ef][3] benzazepine) shows a similar selectivity profile to the previously reported alpha adrenoceptor antagonist, SK&F 104078 (6-chloro-9-[(3-methyl-2-butenyl)oxy]-3-methyl-1H-2,3,4,5-tetrahydro-3- benzazepine), having the ability to block alpha-1 and postjunctional alpha-2 adrenoceptors, although having little or no activity at most prejunctional alpha-2 adrenoceptors. SK&F 104856 is more potent than SK&F 104078, and lacks the 5-hydroxytryptamine receptor antagonist activity associated with the earlier compound. The postjunctional vs. prejunctional selectivity of SK&F 104856 at alpha-2 adrenoceptors in the same tissue preparation was demonstrated in both canine and human saphenous vein. Concentrations substantially higher than those required to block postjunctional alpha-2 adrenoceptor-agonist induced vasoconstriction had no effect on the ability of norepinephrine, acting on prejunctional alpha-2 adrenoceptors, to inhibit stimulation evoked transmitter overflow in the human tissue, and only a small effect in the canine vein. As observed with SK&F 104078, SK&F 104856 has some prejunctional alpha-2 adrenoceptor antagonist activity in the rat vas deferens, although the receptor dissociation constant is nearly 50-fold higher than that at the postjunctional alpha-2 adrenoceptor in the canine saphenous vein. The results obtained with SK&F 104856 provide additional evidence to support the premise that alpha-2 adrenoceptors can be functionally differentiated. Because SK&F 104856 can selectively antagonize certain alpha-2 adrenoceptor-mediated responses, this agent may be a useful tool to evaluate the functional roles of the multiple alpha-2 adrenoceptor subtypes that have been identified in biochemical and molecular studies.

Adrenergic alpha-Agonists↗
PubMed1979

Pyranenamines: a new series of antiallergic compounds.

Condensation of 3,5-diacylpyrantriones with various aromatic amines gave a new class of potent, orally active, antiallergic compounds, the 3-[(arylamino)ethylidene]-5-acylpyrantriones, hereafter referred to as pyranenamines, as evaluated not only in the traditional rat passive cutaneous anaphylaxis (PCA) assay but also in the in vitro fragmented rat and primate lung assay. Potencies in the PCA system, when measured intravenously, reached a maximum ID50 of 0.9 mu/kg (1000 times more potent than disodium chromoglycate) with 5-acetyl-4-hydroxy-3-[1-[(3,5-bis-glyceramoylphenyl)amino]ethylidene]-2H-pyran-2,6(3H)-dione (100), as predicted by structure-activity relationship (SAR) analysis. Potencies in the iv PCA system correlated well with potencies in the in vitro rat lung system but not with potencies in the oral PCA system or the in vitro primate lung system. Several compounds had good oral potency, and one analogue, 3-acetyl-4-hydroxy-3-[1-[3-amino-4-hydroxyphenyl)amino]ethylidene]-2H-pyran-2,6(3H)-dione hydrochloride (78), reached an oral ID50 of less than 1 mg/kg and was better than 10 times more effective than disodium chromoglycate at inhibiting the release of histamine and slow-reacting substance of anaphylaxis in the fragmented primate lung assay.

Administration, Oral↗