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Biomedical subjects

M K Gupta

Publications and source records attributed to M K Gupta.

At least 109 records · Page 6Linked to original sources

A simple semiquantitative radiometric measurement of antithyroglobulin antibodies in human serum. Comparison with hemagglutination method.

A simple solid-phase radiometric assay for the measurement of thyroglobulin autoantibodies (TgRA) was developed and evaluated. The assay is semiquantitative, and the results were expressed as a ratio between sample versus negative control (normal human serum). In 59 normal subjects, the mean ratio was 0.93 +/- (SD) 0.34. Thyroglobulin antibodies by radiometric assay, by hemagglutination (TgHA), as well as microsomal antibodies by hemagglutination (MCHA) were measured in 41 patients with a histopathologic diagnosis of Hashimoto's thyroiditis (n = 22), adenomatous goiter (n = 10), carcinoma (n = 5), adenoma (n = 4), and in 59 patients without histopathologic diagnosis of thyroid disease. In patients with Hashimoto's thyroiditis, TgRA, TgHA, and MCHA were positive in 54, 31, and 81% of patients, respectively. 1 patient had positive TgRA with negative MCHA levels, and 2 had negative antibody titers by all methods. Thyrotropin-stimulating hormone levels were elevated (greater than 10 microU/ml) in 17 of these patients. Our results suggest that although the TgRA method is more sensitive than TgHA for detecting thyroglobulin antibodies, its diagnostic sensitivity is not equal to that of MCHA.

Autoantibodies↗

Effect of thyroxine on immune response in C57Bl/6J mice.

The effect of T4 treatment (40 micrograms, 5 times/week) on immune function in C57Bl/6J mice was studied. The primary antibody synthesis as measured by the plaque-forming cell (PFC) assay demonstrated significant suppression in mice treated with T4 for 30 days. Mitogen assays using PHA and Con A demonstrated significant suppression of cellular immune responses as measured by [3H]thymidine incorporation. The effect was reversed when the treatment was discontinued and a normal response reappeared after 14 days. Allogeneic skin grafts (donor A/J mice) showed prolonged survival (median survival time, 13.5 days) in T4-treated mice as compared to control untreated mice (median survival time, 11 days). Further experiments using Chromium 51 assay for delayed type hypersensitivity also showed suppressed response. These results suggest that treatment with T4, in the above doses and duration, cause immunosuppression in C57Bl/6J mice.

Animals↗

Dependence of tolerance dose on irradiated volume in radiotherapy, and determination of volume corrected time, dose and fractionation factors.

Clinical observations demonstrate that the tolerance dose depends on the volume of normal tissues irradiated. It has been found to decrease if volume size irradiated increases. A relationship between tolerance dose and volume irradiated has been derived. The time, dose and fractionation (TDF) factors given by Orton and Ellis (1973) do not include the effect of volume size of irradiation. That relationship has been used to derive equations of partial tolerance (PT) and TDF factor incorporating the treatment volume size. The incorporation of this factor becomes more important when treating deep-seated tumours and when large volumes of normal tissue are involved. The value of the TDF factor changes by 30% when volume irradiated increases from 500 to 1400 cc for 200 cGy per fraction in three fractions per week schedule.

Adult↗

Immunochemical measurement of serum prostatic acid phosphatase (PAP). Clinical evaluation of radioimmunoassay and counter immunoelectrophoresis.

Two radioimmunoassay procedures (RIA-1 and RIA-2) were evaluated for the quantitation of prostatic acid phosphatase in serum and compared with the enzymatic method and counter immunoelectrophoresis method for their specificity and sensitivity. Sera from 168 patients were analyzed and these included: normals, 27; untreated prostatic cancer patients Stage A, 2; Stage C, 3; Stage D, 17; cancer of prostate treated with different modalities, 42; sarcoma of prostate, 1; prostatitis, 3; nonprostatic carcinoma, 17; and benign prostatic hyperplasia (BPH), 56. RIA-1 procedure appeared more sensitive (82% sensitivity) and specific (94.5% specificity) than the RIA-2 procedure (68% sensitivity and 91.8% specificity), but the differences were not statistically significant. The enzymatic method was found to be least sensitive (63.6% sensitivity) but also the most specific (100% specificity). Only 69 of the specimens were analyzed by counter immunoelectrophoresis, which showed sensitivity of 87% and specificity of 51.4%. False positives were observed more often in patients with nonprostatic cancer and BPH. The variations in diagnostic specificity of immunologic assays suggest the need of characterization of each antibody specificity.

Acid Phosphatase↗