Characterization and sequencing of a 40-amino-acid peptide from human thyroglobulin inducing experimental autoimmune thyroiditis

We previously demonstrated that: a) a cytotoxic T cell hybridoma (HTC2) was able to induce lysis of syngeneic macrophages pulsed with either porcine thyroglobulin (pTg) or the tryptic fragments (TF) from pTg less than 10 kDa (M(r)) and that b) these low M(r) pTg TF included pathogenic epitopes because their injection into CBA/J mice induces thyroid lymphocytic infiltration typical of experimental autoimmune thyroiditis. Therefore the biochemical analysis of the TF preparation from pTg less than 10 kDa M(r) was undertaken and the characterized peptides were tested for their ability to be recognized or not by HTC2 cells. The sequencing of the selected peptides showed a 70% sequence homology with a portion of human thyroglobulin (hTg). The lack of a published sequence of pTg led us to synthesize a 40-amino acid peptide (F40D) similar to that portion of hTg. This F40D peptide was able to generate lymphocytic infiltrations in CBA/J mice thyroid glands, as was the native pTg molecule. Although the lymphocytic infiltrations were similar in the pTg or F40D-immunized mice, auto-antibodies to pTg or to hTg were only detectable in mice immunized with pTg. In contrast, autoantibodies levels to F40D peptide were significantly increased in serum from mice in which EAT had been induced by the F40D peptide. This highly hydrophobic peptide shows a M(r) of 4,492 kDa; it is located at the end of the second-third of the thyroglobulin molecule and up to now represents a unique sequence from the hTg molecule inducing experimental autoimmune thyroiditis.

Characterization and sequencing of a 40-amino-acid peptide from human thyroglobulin inducing experimental autoimmune thyroiditis

We previously demonstrated that: a) a cytotoxic T cell hybridoma (HTC2) was able to induce lysis of syngeneic macrophages pulsed with either porcine thyroglobulin (pTg) or the tryptic fragments (TF) from pTg less than 10 kDa (M(r)) and that b) these low M(r) pTg TF included pathogenic epitopes because their injection into CBA/J mice induces thyroid lymphocytic infiltration typical of experimental autoimmune thyroiditis. Therefore the biochemical analysis of the TF preparation from pTg less than 10 kDa M(r) was undertaken and the characterized peptides were tested for their ability to be recognized or not by HTC2 cells. The sequencing of the selected peptides showed a 70% sequence homology with a portion of human thyroglobulin (hTg). The lack of a published sequence of pTg led us to synthesize a 40-amino acid peptide (F40D) similar to that portion of hTg. This F40D peptide was able to generate lymphocytic infiltrations in CBA/J mice thyroid glands, as was the native pTg molecule. Although the lymphocytic infiltrations were similar in the pTg or F40D-immunized mice, auto-antibodies to pTg or to hTg were only detectable in mice immunized with pTg. In contrast, autoantibodies levels to F40D peptide were significantly increased in serum from mice in which EAT had been induced by the F40D peptide. This highly hydrophobic peptide shows a M(r) of 4,492 kDa; it is located at the end of the second-third of the thyroglobulin molecule and up to now represents a unique sequence from the hTg molecule inducing experimental autoimmune thyroiditis.

Changes in lipid content and composition during the development of N-nitrosodiethylamine induced hepatocarcinoma

Alterations in lipid content and composition in the N-nitrosodiethylamine-induced hepatocarcinoma were investigated. Rats were administered with N-nitrosodiethylamine in the drinking water for 12 weeks followed by normal tap water for another 6 weeks. The cholesterol content in the liver was increased shortly after the administration of N-nitrosodiethylamine and remained elevated after the removal of the nitrosoamine from the water. The phosphatidylethanolamine level was elevated during N-nitrosodiethylamine administration with a concomitant reduction in phosphatidylcholine level. Lysophosphatidylcholine and sphingomyelin levels were increased during the last four weeks of the study. The level of phosphatidylinositol was substantially reduced after eight weeks of N-nitrosodiethylamine treatment, and remained low during the post-treatment period. We postulate that changes in lysophosphatidylcholine and sphingomyelin may be a compensatory mechanism for maintaining the asymmetrical distribution of choline-containing lipids in the outer leaflet of the membrane. The elevated level of cholesterol may be a useful indicator for the early detection of N-nitrosodiethylamine-induced hepatocarcinoma.

Quasi-periodic motion in a hybrid optical bistable system with a short delay

The dynamical behavior of a hybrid optical bistable system with a short delay is calculated numerically in detail. The quasi-periodic motion and frequency locking of the system are observed experimentally.

[The measurement of umbilical artery flow velocity waveforms in normal late pregnancy by Doppler ultrasound]

Doppler ultrasound was adopted in a study of fetal umbilical artery flow velocity waveforms in 81 cases of late pregnancies (28-41 gestational weeks). The peak systolic/end-diastolic ratio (A/B) and the Pourlot index were used as indices for assessing placental resistance. Both the A/B ratio (2.34 +/- 0.44) and Pourlot index (0.56 +/- 0.07) decreased while the gestational week was increasing, and they had a good correlation with the gestational week (r1 = -0.90, r2 = -0.93). The results indicated that the placental resistance became lower when the gestational week was increasing. This method has been documented a useful noninvasive technique for the exam of placental resistance.

[Binaural interaction in human auditory brainstem responses]

The auditory brainstem responses (ABR) were recorded from 20 adults aged 16 to 43 year with normal hearing using a paired click stimuli with interaural time differences (delta T = 0-3 ms). The Binaural Interaction (BI) was studied by computer to obtain a curve of derived ABR. The results showed that there was a different waveform at the region of wave V. It seems to have arose from the region of midbrain when delta T = 0-2 ms and showed a good stability.

Autoantibody specific for a thyroglobulin epitope inducing experimental autoimmune thyroiditis or its anti-idiotype correlates with the disease

In order to elucidate the role of anti-thyroglobulin (Tg) autoantibodies (A-Ab) in experimental autoimmune thyroiditis (EAT), a kinetic study was conducted in EAT-susceptible (CBA/J) and non-susceptible (C57BL/6) strains of mice. From day 0 to 70 post-Tg immunization, titers of A-Ab to Tg and to the linear 5-10-kDa Tg tryptic fragment inducing EAT as well as anti-idiotypic A-Ab representing the internal image of the thyroidogeneic antigen were measured. EAT onset, development and recovery correlate with the presence of two subsets of A-Ab only in susceptible strains of mice. First, with the presence of anti-Tg A-Ab to one determinant borne by the linear 5-10-kDa Tg tryptic fragment, and second with the presence of anti-idiotypic A-Ab specific for the monoclonal anti-Tg A-Ab (3B8G9) paratope which binds to Tg determinant inducing EAT.

[Primary serologic investigation of HBV-like virus existence in domestic animals and fowls]

Using the reagent kits for detecting human HBV, primary serologic investigation was made in 6 kinds of domestic animals and fowls (total 673) by ELISA, spot hybridization and immuno-electronmicroscopy. The results showed that some sera samples of pigs, rabbits, chicken and geese were HBsAg, HBeAg positive and positive for spot hybridization by using 3(2)P-HBV-DNA probe, which suggested that HBV-like viruses might exist in those domestic animals and fowls. HBV-like virus particles were seen in one pig serum sample which was HBsAg positive. The particles could be divided into three forms in shape, large spherical particle (40-55nm), small spherical particle (20-30nm) and short filament particle. The further studies are needed.

Allogeneic bone marrow transplantation for the treatment of leukemia

Eighteen patients with leukemia have received HLA-identical allogeneic bone marrow transplantation (BMT) at our hospital since 1981. Fifteen of these patients have been living without relapse. for prophylaxis of GVHD, MTX was used in 8 patients, and cyclosporine (CSP) together with MTX in 6 patients, 3 received multiple agents at much smaller dosage, including monoclonal antibody. All patients received intravenous placental gamma-globulin, and 16 received garlic extract. Three patients died. One, who neither received MTX, nor CSP died of hyperacute GVHD, one who did not receive garlic extract died of GMV pneumonia, and the third one died of tuberculosis 18 months after BMT.

Rheological Determination of Molecular Weight and Molecular-Weight Distribution for Commercial-Type Butyl Elastomers

1. There exists a linear correlation between rheological parameters (crossover frequency and crossover modulus) and structural parameters (Mw, and MWD) for commercial-type butyl elastomers. 2. There appears to be potential value in utilizing rheological testing for quality control for commercial-type butyl elastomers. 3. Further work is required to resolve testing problems (air entrapment and sample trimming) which affect the precision of the rheological measurements.