Influence of lithium on cell function in two different cell systems.

Lithium is widely used in the treatment and prophylaxis of bipolar psychiatric disorders. It accumulates in the thyroid gland and can cause goitre or thyroid dysfunction. The mechanisms of various effects of the lithium ion on thyroid cells have not been completely clarified. The aim of our work was to establish whether lithium, in the presence or absence of TSH, stimulates the synthesis of cAMP; as model systems we used a strain of rat thyroid follicular cells FRTL-5 and a line of Chinese hamster ovary fibroblasts with the human TSH receptor (CHO-R). Lithium at concentrations of 0.35 mM, 1 mM, 1.4 mM, 1.7 mM and 2 mM without TSH and at selected concentrations with TSH stimulation significantly increased cAMP synthesis in FRTL-5 and in CHO-R cells when compared with controls without lithium. These results are different from the published data, which have been unable to confirm the influence of lithium on cAMP synthesis or have even reported the inhibition of cAMP synthesis. However, in most published investigations only lithium in combination with TSH was tested. In conclusion, lithium was found to stimulate cAMP synthesis in FRTL-5 cells and in CHO-R cells.

Influence of lithium on growth and viability of thyroid follicular cells.

Lithium accumulates in the thyroid gland and can cause goiter or thyroid dysfunction. The aims of our work were: 1) to verify whether lithium stimulates proliferation of thyroid cells; as methods, the 3H-thymidine incorporation assay and the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) were used; as a model system the FRTL-5 (Fischer rat thyroid cells in low serum) cell line was selected, 2) to test whether lithium can have a cytotoxic effect on FRTL-5 cells, using the cytotoxicity assay with 51Cr release and the trypan blue exclusion method. Without TSH stimulation, lithium at 0.35-2 mM concentrations significantly increased the 3H-thymidine incorporation. A similar effect was observed in the case of the MTT assay: without TSH stimulation, lithium at 0.4-2 mM concentrations showed a significant stimulation of proliferation. Surprisingly, under TSH stimulation, lithium at the 2 mM concentration significantly inhibited proliferation of FRTL-5 cells. With the cytotoxicity assay, lithium was found to increase 51Cr release at 1.4-2 mM concentrations. Additionaly, the percentage of viable FRTL-5 cells at 0.35-2 mM concentrations of lithium was lower than in the controls without lithium. In conclusion, lithium was found to stimulate proliferation of FRTL-5 cells in conditions without TSH and, surprisingly, lithium in higher concentrations diminished proliferation of FRTL-5 cells under TSH stimulation. A cytotoxic effect of higher lithium concentrations was observed.

Secured medical imaging over the Internet.

The Internet has established itself as an affordable, extremely viable and ubiquitous communications network that can be easily accessed from virtually any point in the world. This makes it ideally suited for medical image communications. Issues regarding security and confidentiality of information on the Internet, however, need to be addressed for both occasional, individual users and consistent enterprise-wide users. In addition, the limited bandwidth of most Internet connections must be factored into the development of a realistic usermodel and resulting protocol. Open architecture issues must also be considered so that images can be communicated to recipients who do not have similar programs. Further, application-specific software is required to integrate image acquisition, encryption and transmission into a single, streamlined process. Using Photomailer software provided by PhysiTel Inc., the authors investigated the use of sending secured still images over the Internet. The scope of their investigation covered the use of the Internet for communicating images for consultation, referral, mentoring and education. Photomailer software was used at several local and remote sites. The program was used for both sending and receiving images. It was also used for sending images to recipients who did not have Photomailer, but instead relied on conventional email programs. The results of the investigation demonstrated that using products such as Photomailer, images could be quickly and easily communicated from one location to another via the Internet. In addition, the investigators were able to retrieve images off of their existing email accounts, thereby providing greater flexibility and convenience than other systems which require scheduled transmission of information on dedicated systems. We conclude that Photomailer and similar products may provide a significant benefit and improve communications among colleagues, providing an inexpensive means of sending secured images on the Internet.

The effect of chronic hypercalcemia or hypocalcemia on the follicular and parafollicular cells in rat thyroid gland.

In three experiments of 30 weeks' duration, 93 adult female Wistar rats received controlled amounts of calcium with food and water, to produce a state of either hypercalcemia or hypocalcemia. A systematic stereological analysis of the thyroid glands and a radioimmunological analysis of thyroxine, triiodothyronine, and thyrotropine were performed. In the hypercalcemic rats, a reactive hyperplasia of the parafollicular cells was established; this was accompanied by morphological and biochemical signs of hyperfunction of the follicular cells, despite a reduced central stimulation by thyrotropin. In the hypocalcemic animals, no quantitative morphological changes in the parafollicular cells were observed; however, morphological and biochemical signs of hypofunction of the follicular cells were obvious, despite stronger central stimulation by thyrotropin. It is concluded that the extrinsic regulation of follicular cells by the blood calcium level is stronger than the intrinsic regulation by hypothalamo-hypophyseal hormones.

Beta 2-microglobulin elimination characteristics during hemofiltration with acrylonitrile and polysulfone membrane hemofilters.

Elimination characteristics of beta 2-microglobulin (BMG) during hemofiltration (HF) with acrylonitrile (AN69) and polysulfone (PS) hemofilters were investigated in a prospective clinical investigation. Seven chronic uremics on regular HF were treated for 4 weeks, three times a week, with AN69 hemofilters. The study was then repeated with PS hemofilters. There were no significant differences in the patients' body weight, the ultrafiltrate volume per session, and the duration of each HF session between both treatments. At the start of HF, arterial plasma concentration of BMG was (for AN69) 33.5 +/- 4.0 mg/L (mean +/- SD) and (for PS) 35.8 +/- 6.5 mg/L (NS); at the end of HF it was (for AN69) 11.0 +/- 1.8 mg/L and (for PS) 17.5 +/- 4.2 mg/L (p less than 0.001). The amount of BMG in total ultrafiltrate was (for AN69) 179.3 +/- 22.6 mg and (for PS) 140.6 +/- 26.8 mg (p less than 0.02). With AN69 hemofilter, maximum BMG plasma clearance and sieving coefficient were 51.0 +/- 9.5 mL/min and 0.42 +/- 0.04 at 60 minutes. With PS hemofilter, maximum BMG plasma clearance and sieving coefficient were 37.4 +/- 5.7 mL/min and 0.27 +/- 0.03 at 15 minutes. Twenty-two percents of BMG entering the AN69 hemofilter at 15 minutes were adsorbed on the membrane (p less than 0.001). BMG elimination with the AN69 hemofilter was more efficient than with the PS hemofilter. Long-term studies will be necessary to demonstrate whether this difference is of any clinical significance.

Correlation between thyroxine, triiodothyronine and thyrotropin in geriatric patients with goitre.

Serum TSH, T4 and T3 have been assayed in three groups of older persons (greater than 60 years): in 28 normal subjects (A), in 80 patients with nontoxic goitre (B), in 22 patients with hyperthyroidism (C). Group B was divided in group B-1 (TSH 0.20-0.30 mU/l) and group B-2 (TSH greater than 0.30 mU/l). The test characteristics were determined by comparison of group C patients with group A patients and the former with group B patients. The specificity and posterior probability of TSH test calculated by the first comparison was 1.0 for both characteristics, and by the second comparison TSH test specificity was 0.75 and posterior probability 0.62. Specificity of thyroid hormones calculated in the second comparison was 0.96 for T4-test and 0.94 for T3-test. Therefore TSH test is the most adequate in clinical diagnostic of thyrotoxic goiter. The particularities of several groups were: B-2 group had significantly lower mean value of T4 than Group A, but there was no significant difference between mean values of TSH found. There were no correlations between TSH and T4 and between T4 and T3. Group B-1 had significantly lower mean TSH value than Group A and Group B, but the groups did not differ in mean T4 value. The correlation between TSH and T4 in group was positive as the correlation between T4 and T3. It is suggested that the value of serum T4 of Group B-1 may be inappropriately low due to defective immunological activity of T4 from autonomous follicles.(ABSTRACT TRUNCATED AT 250 WORDS)

[Significance of radioimmune method for detection of HB antigen in blood donors]. / Znacaj radioimune metode za testiranje HB antigena kod davalaca krvi

The evaluation of frequency of HBag in 923 blood donors is given: the counterelectrophoresis demonstrates HBag positive cases in 1, 2% the radioimmunoassay (Ausria-125, Abbott) in 1, 5%. The haemagglutination (Hepanosticon, Organon) in 7 cases, which were negative with counterelectrophoresis, and positive with the radioimmunoassay, discovers HBAg in 3 cases. RIA method is more sensitive in the control of HBAg positive donors after two to three years, and in detecting of immuno complexes prepared in vitro. The titre of the antigen is 1000 times higher when made with RIA method, and up to 60 times higher when made with the method of haemagglutination than with the counterelectrophoresis. In 4 cases of hepatitis after transfusion of HBAg negative blood, determined with counterelectrophoresis, have been involved bottles, which were positive only with RIA Method. Austria II-125 (Abbott) method was comparatively tested with counterelectrophoresis on different groups--446 persons.