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Biomedical subjects

S Sakata

Publications and source records attributed to S Sakata.

At least 307 records · Page 17Linked to original sources
PubMed1982

[A study on anti-T3 and anti-T4 autoantibodies found in two sisters with juvenile hypothyroidism due to Hashimoto's thyroiditis: II. The effect of treatment with L-thyroxine].

We previously reported that two sisters with juvenile hypothyroidism due to Hashimoto's thyroiditis (Case 1: 13 years old, Case 2: 10 years old) had antibodies against thyroid hormones. Treatment was started with 12.5 micrograms of L-T4 per day in Jan. 1980. The doses were gradually increased, and after 1 year of treatment, both patients were clinically euthyroid on 100 micrograms of L-T4 per day, and the heights of Case 1 and of Case 2 had increased by 9 cm and by 10 cm, respectively. Serum TSH levels were decreased from 1088 microU/ml to 1.7 microU/ml in Case 1, and from 1300 microU/ml to 2.1 microU/ml in Case 2. The titers of antithyroglobulin antibodies as measured by solid phase RIA decreased in both patients after the treatment. The bindings of 125I-T3 and of 125I-T4 to sera in the presence of 8-anilino-1-naphthalene sulfonic acid to block binding to TBG (non-treated sera) were markedly higher in the two patients before therapy than those in ten normal controls (11.8% and 52.3% in Case 1, 46.8% and 21.5% in Case 2, and 5.9 +/- 0.6% and 4.1 +/- 0.5% (mean +/- SD) in the controls, respectively). After the 1 year treatment, the bindings of 125I-T3 and 125I-T4 decreased to normal levels in Case 1 (5.8% and 3.8%, respectively). In Case 2, the 125I-T4 binding decreased to the normal level (4.7%), whereas the 125I-T3 binding decreased but still remained above the normal level (10.6%). In order to exclude the interference of endogenous and/or therapeutic thyroid hormones with the binding of labelled hormones to sera, the sera were treated with dextran-coated charcoal at pH3.0 (acid-treated sera). The bindings of 125I-T3 and 125I-T4 to acid-treated sera were clearly higher in both patients before therapy than those in ten normal controls (16.9% and 60.7% in Case 1, 75.0% and 46.4% in Case 2, and 6.9 +/- 0.7% and 6.8 +/- 0.7% (mean +/- SD) in the controls, respectively), and these values were compatible with those from non-treated sera. After the 1 year treatment, however, the results of acid-treated sera were different from those of non-treated sera. That is, the bindings of 125I-T3 and of 125I-T4 to acid-treated sera from both patients decreased but remained above normal levels (9.3% and 26.5% in Case 1, and 29.4% and 22.5% in Case 2, respectively). These results indicate the presence of antibodies against thyroid hormones even in the euthyroid state during L-T4 treatment, and also the data obtained from the non-treated sera were affected by endogenous and/or therapeutic thyroid hormones. The importance of acid-charcoal treatment for the detection of anti-thyroid hormone antibodies during thyroid hormone administration was suggested. In the serum from another sister of the reported patients, we also found unusual T4-binding proteins which were only detected by the acid-charcoal treatment. The implications of decrement of anti-thyroglobulin antibodies and of anti-thyroid hormone antibodies were discussed.

Adolescent↗
PubMed1982

Binding with lysozyme of antibodies against surface-simulation peptides representing the lysozyme antigenic sites.

Previously it had been shown that native lysozyme has three discontinuous antigenic sites (comprising spatially adjacent residues that may be distant in sequence) that were mimicked by surface-simulation synthetic peptides that had the capacity to bind the bulk (97-99%) of the antibody response against native lysozyme. In the present work these three surface-simulation synthetic peptides were coupled to succinoylated bovine serum albumin, and the conjugates were injected into rabbits. Antibodies against each peptide reacted, as expected, only with that peptide, but it was also found that the antibodies could bind with lysozyme, and the complete specificity of this binding was rigorously established. The advantages of these findings in conformational and immunological investigations are outlined.

Antibodies↗
PubMed1982

Immune recognition of serum albumin--XIV. Cross-reactivity by T-lymphocyte proliferation of subdomains 3, 6 and 9 of bovine serum albumin.

Recently, we have shown that, with rabbit antibodies against BSA, the BSA fragments 115-184, 307-285 and 505-582 (essentially corresponding to subdomains 3, 6 and 9 of BSA) exhibit a cross-reaction which increases remarkably with the time antisera are obtained after the initial immunization. In the present report, we have examined whether this cross-reaction at the B-cell level takes place also at the T-cell level. Optimum conditions for T-cell proliferation to BSA and the three fragments were determined in terms of priming dose, challenging dose, time lymph nodes are obtained after immunization and finally duration of culture. Several strains of mice representing independent haplotypes and recombinant strains were examined for their responsiveness to BSA by T-lymphocyte proliferation, performed in the respective preimmune sera of the same mice. This afforded the identification of high- and low-responder strains to BSA. It was determined that the immune response to BSA is controlled by genes in the I-A subregion of the H-2 gene complex with some slight non-H-2 influences. In order to avoid the possibility of genetic exclusion of response to a given antigenic site and to improve the change of total site recognition, two high-responder strains (B10.M and B10.G) were crossed. Antibodies raised in (B10.M X B10.G)F1 mice recognized subdomains 3, 6 and 9 and these were found to be cross-reactive. Specific 125I-labelled antibodies isolated on a given subdomain-adsorbent were bound very well by adsorbents of the other two subdomains. T-cells from the F1 mice that had been primed with subdomain 3 responded to subdomain 3 and were also high responders to subdomain 6 and intermediate responders to subdomain 9. After priming with subdomain 6, the T-cells responded equally as well to subdomains 3 or 6 and slightly to subdomain 9. Finally, priming with subdomain 9, gave T-cells that responded to subdomain 9 and also gave high responses to subdomains 3 or 6. It was concluded that the cross-reactions originally observed at the B-cell level also take place at the T-cell level.

Animals↗
PubMed1982

Comparison of the in vitro and in vivo anti-herpes activities of 1-beta-D-arabinofuranosylthymine and its 5'-monophosphate.

In vitro and in vivo anti-herpes activities of 1-beta-D-arabinofuranosylthymine 5'-monophosphate (ara-TMP) were compared with those of 1-beta-D-arabinofuranosylthymine (ara-T). On a molar basis ara-TMP was almost as active as ara-T against six strains of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) as monitored by a cytopathogenicity-inhibition and a plaque reduction assay in human embryonic lung fibroblast cells. When tested against experimental encephalitis in mice inoculated intracerebrally with HSV-1, intraperitoneal or intravenous treatment with 150 mg/kg/day of ara-TMP or 100 mg/kg/day of ara-T, for 5 days was effective in increasing in the mean survival time of mice. For a single dose of ara-TMP, intravenous administration was more effective than intraperitoneal or oral administration. However, oral administration of ara-T was the most effective of the treatment regimens used. Substantial plasma levels of ara-T were detected for a longer time after oral administration of ara-T than after intravenous administration of ara-TMP or ara-T, suggesting that the efficacy of oral administration of ara-T may be correlated with the maintenance of the substantial blood drug levels.

Animals↗
PubMed1982

[RCT image study by angular interval of sampling].

A multi-purpose gamma camera system which had 2 detectors of opposed position and was capable of radionuclide computed tomography (RCT) imaging was installed in Division of Nuclear Medicine, Chiba Cancer Center Hospital. In this study, the variance of RCT image due to the angular interval of sampling was analyzed. The full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of point source were almost same for all sampling intervals investigated. The distortion of RCT images with uniform activity source could not be detected even for larger intervals. When the RCT images were obtained using a phantom contained 3 line sources and a bar phantom for RCT which were located at right angle with the plane of reconstruction, the images did not change between 1 degrees and 6 degrees of sampling interval, but for 9 degrees or more the distortion of images occurred explicity. For our system, sampling interval of 2 degrees was predicted from the theorectical calculation considering both resolution and statistical noise. But, results from the phantom studies of present work showed that sampling interval of 6 degrees was sufficient to reconstruct RCT images without distortion, and could be applicable to dynamic RCT images.

Models, Structural↗
PubMed1981

High yield coupling of peptides to protein carriers.

Coupling of peptides to protein carriers has been achieved at a high level of peptide incorporation. Bovine serum albumin was used as the model carrier protein and several peptides were tested in the coupling reaction. The peptides were coupled to succinylated bovine serum albumin after conversion of its carboxyl side chains to the reactive p-nitrophenyl ester group by reaction with p-nitrophenol/N,N'-dicyclohexylcarbodiimide in anhydrous dimethylformamide. The reaction afforded succinyl-albumin-peptide conjugates that had high level of peptide incorporation (18-35 mol peptide/mol albumin). In addition to the high level of peptide coupling, the reaction avoids the production of polymeric forms of peptide, protein or conjugate.

Carrier Proteins↗
PubMed1981

Antiherpesviral and anticellular effects of 1-beta-D-arabinofuranosyl-E-5-(2-halogenovinyl) uracils.

1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl) uracil (BV-ara-U) and 1-beta-D-arabinofuranosyl-E-5-(2-chlorovinyl)uracil (CV-ara-U) were tested for their anti-herpesviral activity in virus rating method, a plaque reduction method, and a virus yield reduction method, using human embryonic lung fibroblast (HEL-F) cells, At a concentration as low as 0.1 microgram/ml, both drugs exerted a marked inhibitory effect on the development of cytopathogenic effect induced by herpes simplex virus type 1 (HSV-1) infection and on the multiplication and plaque formation of HSV-1. Neither BV-ara-U nor CV-ara-U was significantly active against HSV type 2 (HSV-2). They scarcely inhibited growth of HEL-F cells, mouse L, and murine leukemia cells. Compared with 1-beta-D-arabinofuranosylthymine and 5-iodo-deoxyuridine, BV-ara-U and CV-ara-U were more than 10 times as active against HSV-1 and much less active against HSV-2. BV-ara-U was as active as E-5-(2-bromovinyl)-2'-deoxyuridine against HSV-1 and less inhibitory to growth of HEL-F cells. Cellular deoxyribonucleic acid synthesis was not significantly influenced by the new derivatives of arabinosyluracil, even at a concentration as high as 300 microgram/ml. The derivatives showed extremely marked inhibition of deoxyribonucleic acid synthesis in HSV-1-infected cells, whereas their inhibitory effect on deoxyribonucleic acid synthesis in HSV-2-infected cells was much lower than that in HSV-1-infected cells. These findings indicate that BV-ara-U and CV-ara-U are selectively inhibitory to HSV-1 multiplication.

Antiviral Agents↗
PubMed1980

Immune recognition of serum albumin. 11. Mouse antibodies against bovine serum albumin recognize the same antigenic sites that are recognized by rabbit antibodies.

In recent studies, we have localized and confirmed by synthetic peptides five major antigenic sites in each of bovine and human serum albumins which are recognized by rabbit antibodies against the respective protein. In order to determine whether the antigenic sites of albumin are peculiar to the protein or are dependent on the species of the immunized host, we have studied here the specificity of the antibody response in outbred mice against bovine serum albumin. By immunoadsorbent titration studies, the synthetic antigenic sites, previously localized with rabbit antisera against bovine serum albumin, were shown to bind considerable amounts of specific mouse 125I-labelled antibodies against bovine serum albumin. The amounts of mouse anti-bovine serum albumin antibodies bound by the adsorbents of the synthetic sites were comparable to the amounts of rabbit anti-bovine serum albumin antibodies that could be bound. It was concluded that recognition of the antigenic sites of serum albumin is independent of the immunized species and is inherent in their structural and conformational uniqueness.

Animals↗
PubMed1980

Antibodies to synthetic antibody-combining sites. Antibodies against a surface-simulation peptide with antibody-combining activity toward lysozyme antigenic site 3 react with lysozyme antibodies.

Recently, we reported the synthesis and immunochemistry of two peptides designed, by complementarity and surface-simulation synthesis, to mimic antibody-combining sites against two antigenic sites of lysozyme. In the present work antibodies were raised against one of these peptides, which is complementary to antigenic site 3 of lysozyme, to determine whether these antibodies will react with anti-lysozyme antibodies. Radioiodinated antipeptide antibodies were bound by immunoadsorbents of the immune IgG from two goats anti-lysozyme antisera but not by adsorbents of myoglobin, non-immune goat IgG or immune IgG of antisera against cytochrome c. The binding of anti-peptide antibodies to adsorbents of anti-lysozyme antibodies was fully inhibited by free lysozyme but not by bovine serum albumin, human hemoglobin A, horse cytochrome c or bovine ribonuclease A. Thus, antisera against an antibody-combining site can be raised by immunizing with a peptide which probably does not exist in the antibody but is designed by surface-simulation synthesis to mimic an antibody-combining site.

Animals↗
PubMed1980

Synthesis and antiherpesviral activity of 5-C-substituted uracil nucleosides.

Reaction of 2'-deoxy-5-hydroxyuridine with some Wittig reagents gave 5-alkoxycarbonylmethyl-, 5-carbamoylmethyl-, 5-cyanomethyl-and 5-acetonyl-2'-deoxyuridines. The corresponding 1-beta-D-arabinofuranosyl derivatives were prepared from 1-beta-D-arabinofuranosyl-5-hydroxymethyluracil. The latter was also converted to 1-beta-D-arabinofuranosyl-5-vinyluracil via triphenylphosphonium salt, and then to 5-(2-halogenovinyl)derivatives. Some of these compounds showed marked antiherpesviral activity in vitro.

Antiviral Agents↗