Thyroglobulin release-stimulating activity in immunoglobulin G from patients with Graves' disease studied by human thyroid cells in vitro.

The ability of TSH or immunoglobulin G (G-IgG) from untreated patients with hyperthyroidism due to Graves' disease to stimulate thyroglobulin (Tg) release from human thyroid cells was studied. Thyroid tissue obtained from antithyroid drug-treated Graves' hyperthyroid patients was dispersed enzymatically and cultured in monolayers; medium was changed every 3 days. The cultured cells initially released large but declining amounts of Tg, independent of the presence of TSH (approximately 5 micrograms/dish on day 3 and approximately 1.5 micrograms/dish on day 6). After 6 days, TSH had a dose-dependent stimulatory effect on Tg release, and the peak response occurred on day 15. G-IgG-induced Tg release was found on the 12th day of culture and was maximal on day 18. Thyroid cells cultured for 12 days in the absence of TSH responded to TSH and G-IgG in a time- and dose-dependent fashion. Using 12-day cultures, Tg release-stimulating activity (Tg-RSA) was tested using 5 mg/ml (7.5 mg/dish) G-IgGs from 20 patients and 72-h incubation. The Tg-RSA of individual patients varied. However, significant correlations were found between Tg-RSA values and serum Tg concentrations or Tg-RSA and thyroid-stimulating immunoglobulin activities. No correlation was found between Tg-RSA and TSH binding inhibitor immunoglobulin activities. These results suggest that Tg-RSA can be an indicator of abnormal IgG of hyperthyroid Graves' patients. Whether the activity is identical with thyroid-stimulating activity remains to be clarified.

Spectrophotometric determination of manganese with 1-(2-pyridylazo)-2-naphthol and a non-ionic surfactant.

A spectrophotometric method for the determination of trace amounts of manganese with 1-(2-pyridylazo)-2-naphthol (PAN) is described. The method is based on the measurement of absorbance of the manganese-PAN chelate solubilized with a non-ionic surfactant, Triton X-100. No extraction procedure is required in the method proposed. High concentrations of calcium, aluminium and magnesium do not interfere. The presence of up to 10 ppm of lead can be tolerated. Iron, cadmium, zinc, cobalt and nickel can be effectively masked with potassium cyanide. Beer's law is obeyed up to 2 ppm of manganese. The molar absorptivity of the manganese-PAN chelate found was 4.4 x 10(4) l. mole (-1). cm(-1) at 562 nm. The overall stability constant of Mn(PAN)(2) in 0.4% Triton X-100 medium is 10(16.8).

The potential of a nursing education support system using videoconferencing.

Japan currently employs a total of 400,000 practical nurses, accounting for approximately 40% of the total number of nurses in the country. An education system for improving the skills of practical nurses and encouraging them to obtain certification as registered nurses is due to begin in 2001. In Hokkaido, 90 nursing schools are scheduled to be used as transitional education facilities. These, however, tend to be concentrated in large cities. We have examined the possibilities for an education support system for nurses using videoconferencing. The system will include theoretical lectures using television broadcasts and technical lectures conducted at training facilities. Given Hokkaido's geographical conditions, a support system using telecommunication is considered to be essential for the success of transitional education.

Changes in thyroglobulin release-stimulating activity (Tg-RSA) in immunoglobulin G from patients with Graves' disease during therapy with thionamide drug.

We have reported previously a new method for detecting thyroglobulin release stimulating activity (Tg-RSA) by human thyroid monolayer cells in IgGs from Graves' patients. We report here changes in Tg-RSA in sera of patients during treatment with thionamide drug. Nineteen untreated patients had their Tg-RSA, TSAb, TBII and serum Tg concentration (STg) followed up. Before treatment, Tg-RSA and TSAb were positive in all 19 patients. Three of them were TBII negative. During treatment with thionamide, of 16 patients who had positive Tg-RSA, TSAb and TBII before treatment, 6 patients continued so during the period of observation. Of the remaining 10 patients, 8 became TBII negative. TSAb only was found negative in one patient and Tg-RSA only declined to negative in another patient. Three patients whose TBII was initially negative, were observed to be negative in all three indicators after treatment. STg was higher than normal in all patients before therapy and changes in Tg-RSA in almost all patients were parallel with those in STg during treatment. From the observation during treatment with thionamide, our results suggest that Tg-RSA in Graves' patients appears to have similar properties to TSAb.

A bioassay for thyroid stimulating immunoglobulins of patients with Graves' disease using porcine thyroid monolayer cells.

A bioassay for thyroid stimulating immunoglobulins (TSI) of patients with Graves' disease was developed by porcine thyroid monolayer cells. Thyroid cells were prepared by dispersion using collagenase and trypsin. Aliquots of the cell suspension (2 X 10(6) cells/1.5 ml/dish) in Ham's F-12 medium (pH 7.2) containing 10% calf serum and 1.5 mM Hepes were seeded and cultured in air at 36 C. On day 6 of culture, cells were incubated with test samples (IgG or bTSH) in 1 ml of serum-free, 0.5 mM IMX-included fresh medium for an additional time, and cAMP in the cells was measured by radioimmunoassay. Intracellular cAMP was increased within 5 minutes after the addition of bTSH and the maximal increase was observed after 30 min. Responses of cAMP were in a dose-related manner up to 10 mU/ml of bTSH. With the addition of IgG from untreated Graves' patients, dose-related increases in cAMP were also observed up to 10 mg/ml IgG and the maximal response was seen at 2 hours incubation. Thyroid stimulating activity in IgG's from normal subjects and patients with Graves' disease was tested with a dose of 10 mg/ml and 2 hours incubation and the activity was expressed as a percent of the control (incubated in the same experiment without IgG). One hundred forty one of 145 untreated patients showed higher activity (228 +/- 51.8%, mean +/- SD; 127-393%, range) than normal subjects (103 +/- 13.3%, mean +/- SD, n = 24; 80-129%, range). Sequential changes in TSI activity in 27 patients after initiating thionamide drugs were studied for 24 months. Initially all 27 patients showed positive TSI and 6 months later 15 remained positive. At 6 months after that, 10 of 23, 4 of 16, and 2 of 6 followed patients showed positive TSI. These results indicate that this bioassay is clinically useful for detecting TSI.