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Biomedical subjects

A Seto

Publications and source records attributed to A Seto.

At least 109 records · Page 6Linked to original sources
PubMed1977

Acetylcholine receptor of a myogenic cell line, L6.

The biochemical characters of acetylcholine receptor (AChR) in a myogenic cell line, L6, are as follows. 1. AChR extracted with Triton X-100 has a molecular weight of 5.5 X 10(5) determined by gel-chromatography, an apparent S value of 9.7 determined by sucrose density gradient centrifugation, and an isoelectric point of 5.3. AChR is shown to interact with concanavalin A. 2. The association rate constant of the binding reaction between AChR and alpha-bungarotoxin (alpha-BGT) labelled with 125I is 1 X 10(6) M-1 with S-1 at 35 degrees C. Preincubation with d-tubocurarine blocks the binding. The half-life of the AChR-toxin complex exceeds 180 h.

Acetylcholine↗
PubMed1977

Immunoglobulin M associated with secretory component and immunoglobulin A deficiency in bovine colostrum.

Immunoglobulin (Ig) M purified from bovine colostrum was examined by an immunodiffusion analysis with antisecretory IgA serum and was found to be associated with a secretory component. Some of the combined proteins were dissociated if treated with 5 M guanidine-HCl and others were not. Another immunodiffusion analysis of 23 specimens of colostrum led to the finding that certain colostrums were deficient in IgA, even though they contained IgG and IgM.

Animals↗
PubMed1976

Opsonic activity and O-agglutinins against Escherichia coli in bovine colostrum.

Anticolibacillus antibody activity was examined in 16 samples of bovine colostrum by O-agglutination test with 6 serotypes of Escherichia coli, and its correlation with the manifestation of diarrhea was analyzed for newborn calves fed these colostrums. The 4 colostrums fed to newborn calves having diarrhea within a few days after birth had significantly lower agglutinin titers for all the serotypes tested than did the other colostrums. Other newborn calves fed on the remaining 12 colostrums did not manifest clinical signs of enteric disorders. The agglutinin spectrum against the E coli serotypes was similar between colostrum samples from the same stockfarm, but variable among the farms from which the colostrum had been collected. The agglutinin activity was sensitive to 2-mercaptoethanol and was found mainly in the macroglobulin fraction of gel filtration, indicating that the activity was due to antibodies of the immunoglobulin M type. This was evidenced directly by the agglutination test of purified immunoglobulins. Opsonic activity of colostrum and immunoglobulins purified therefrom was estimated by the rate of decrease in the number of viable E coli injected into mouse peritoneal cavity. The results indicated that the opsonic activity in colostrum was also attributed mainly to immunoglobulin M antibodies, although the contribution of immunoglobulin A and G antibodies was not ruled out. A part of the opsonic activity in colostrum seemed due to heat-labile component(s) as well.

Agglutinins↗
PubMed1975

A new protein with a particular thermoprecipitability in bovine milk.

A new protein with a particular thermoprecipitability was isolated from bovine milk and tentatively termed milk pyroglobulin. The protein which was soluble at a relatively cold temperature was precipitated by raising the temperature to a certain degree depending on the concentration of the protein. The precipitate disappeared on recooling. This protein had the electrophoretic mobility of gamma globulin but did not carry either antigenic specificities of immunoglobulins or of free secretory component. The molecular weight was estimated to be approximately 60,000 in thin-layer gel filtration on Sephadex G-200 superfine gel, but the protein appeared to be convertible to molecules with a lower molecular weight of approximately 20,000 in the presence of bovine serum albumin. The presence of the albumin inhibited the thermoprecipitation as did alpha-lactalbumin but not IgG immunoglobulin from bovine colostrum. In SDS-polyacrylamide gel electrophoresis, the protein was separated into two components having a molecular weight of 19,000 and 10,000, respectively. Both components were thermoprecipitable and carried identical antigenic determinants.

Animals↗