Search PubMed⌕ Search

Biomedical subjects

K Tsukamoto

Publications and source records attributed to K Tsukamoto.

At least 307 records · Page 17Linked to original sources
PubMed1984

[The metabolism and conjugation of estrogens in the human fetus].

Although several studies have been reported on the synthesis of steroids in the fetus, the metabolism and conjugation of estrogens in the fetus is not completely known. In this study serum levels of estetrol (E4), estetrol glucosiduronate (E4-G), estriol (E3) and estriol-16-glucosiduronate (E3-16-G) were measured by R.I.A. in maternal peripheral vein blood (MPV), umbilical artery blood (UA) and umbilical vein blood (UV) at delivery. The same steroids were also measured in various fetal organs (liver, kidney, intestine, adrenal, lung and placenta) in the second-trimester. After 4-14C-E2, 4-14C-E3 and 6, 9 (n)-3H-E4 were incubated with homogenates of various human fetal organs, the metabolites were analyzed with an authentic sample. 15, 15-D2-estradiol-17 beta (d2-E2) was incubated with human second-trimester fetal liver and the metabolites were analyzed with GC-MS. It was concluded that: 1) E3-16-G was higher in UA and UV than in MPV, suggesting active glucosiduronation in the fetus. 2) Higher levels of E4 and E4-G in UA and UV than in MPV suggest the production of E3 and E3-16-G in the fetus. 3) Levels of E4 and E4-G were higher than those of E3 and E3-16-G in various fetal organs in the second-trimester. 4) E4 and E4-G were especially high in fetal liver and intestine, and E3 and E3-16-G were high in fetal kidney, liver and intestine. 5) The level of E3-16-G was higher than that of E3 in these organs. 6) The second-trimester fetal liver conjugated E2, E3 and E4 to each glucosiduronate. 7) The second-trimester fetal kidney conjugated E2 and E4 to each sulfate, but E3 to E3-16-G. 8) 15-Hydroxylation of d2-E2 was demonstrated in the incubation with homogenate of second human fetal liver. 9) The active glucosiduronation of E3 in the fetus was thought to inactivate a large amount of E3 transported from the placenta.

Estetrol↗
PubMed1984

Uptake of estrone and estrone-3-sulfate by lung of macaca fuscata.

An equimolar mixture of 3H-E1-S2 and 14C-E1 was injected in one shot into the inferior vena cava near the heart of female Japanese monkey. Following the injection, blood was collected from the aortic arch at intervals of 15 s over a period of 10 min. The concentration of radioactivities in the whole blood and serum was measured. The metabolites were analyzed by DEAE-Sephadex A-25 column chromatography, enzyme hydrolysis, thin layer chromatography and paper chromatography. Both radioactivities of 3H-E1-S and 14C-E1 rapidly decreased in the first 90-s serum sample. The 3H/14C ratio in the 0-15-s serum sample was 5 times higher than the initial ratio of injected compounds. The radioactivities in the serum gradually decreased after 90 s of injection. The 3H/14C ratio in the pulmonary tissue was very low after collecting the final blood sample. This result shows that the most of 3H-E1-S passed through the lung and the larger part of 14C-E1 remained in the lung following injection of these materials. So, it is probable that E1-S is in a form to be carried in the general circulation.

Animals↗
PubMed1984

Correlation of interferon gamma inducing ability to sugar binding specificities of various lectins.

Various lectins were examined to determine possible induction of gamma interferon (IFN-gamma) in human leukocytes. Among the seven positive lectins (Concanavalin A, pea lectin, lentil lectin, rice bran agglutinin, pokeweed mitogen, wheat germ agglutinin, phytohemagglutinin-P), six except rice bran agglutinin belonged to those which recognize carbohydrate chains connected to polypeptide through a glycosylamine linkage between N-acetylglucosamine (GlcNAc) and asparagine residues. The specificity of carbohydrate chain recognition of rice bran agglutinin, residual one positive lectin, has not been reported. Induction of IFN-gamma by wheat germ agglutinin, one of the positive lectins, was inhibited by the addition of GlcNAc during the induction, but not by the addition of glucose, galactose, alpha-methylmannose, N-acetylgalactosamine, N-acetylmannosamine, and lactose.

Binding Sites↗
PubMed1984

Constitutive production of phagocytosis inducing factor(s) in a monocyte/macrophage lineage cell line (THP-1) by retrovirus-transformed human T cell lines.

Four human T cell lines, MT-2, TCL-Kan, TCL-As 2, and TCL-Haz, established from normal leukocytes by cocultivation with adult T-cell leukemia (ATL) virus (ATLV)-producing cells, produced constitutively phagocytosis inducing factor(s) (PIF) that induced phagocytosis in a human monocytic cell line, THP-1. These cell lines expressed ATLV-associated antigens (ATLA) as well as numerous virus particles, whereas the other twelve leukocyte cell lines tested, including T cell lines, B cell lines, and non-T and non-B cell lines, did not produce detectable amounts of the factor(s) in the culture supernatants. PIF was produced in the absence of serum and was not related to either ATLV-particles or viral structural proteins. Its activity was stable at 56 C for 30 min, but labile at 80 C for 30 min and at pH 2 for 20 hr. MT-2 and TCL-Kan produced large amounts of the factor(s) in the culture supernatants but little interferon-gamma (IFN-gamma) or colony stimulating factor (CSF) activity was detected; furthermore, the activity was not neutralized by rabbit anti-IFN-gamma sera. These observations suggest that some ATLV-transformed T cell lines produce PIF that is different from IFN-gamma and CSF.

Cell Line↗
PubMed1984

Estradiol-17 beta and estradiol-17-glucosiduronate before and at delivery.

The maternal peripheral serum level of estradiol-17 beta (E2), which reaches a peak a few weeks before delivery, may play a role in initiating delivery. In this study, the steroidal activity regulated by both the production and conjugation was estimated by measuring estradiol-17-glucosiduronate (E2-17-G), E2, estriol-16-glucosiduronate (E3-16-G), and estriol (E3) before and at delivery. At delivery, levels of E2 and E2-17-G were higher in the maternal peripheral vein (MP) than in the umbilical vein (UV) and umbilical artery (UA), but those of E3 and E3-16-G were higher in UV and UA than in MP. These results suggested that the production and conjugation of E2 were mainly regulated on the maternal side, but those of E3 were regulated mainly in the feto-placental unit. The ratios of E2/E2-17-G in MP were or became high a few weeks before delivery but decreased remarkably as pregnancy progressed to delivery. The activity of E2 seems to be regulated at least in part by conjugation in late pregnancy and at delivery.

Cross Reactions↗
PubMed1983

Carbenicillin-hydrolyzing penicillinases of Proteus mirabilis and the PSE-type penicillinases of Pseudomonas aeruginosa.

Three carbenicillin-hydrolyzing penicillinases were found in Proteus mirabilis strains, N-3, N-29, and GN79. The former two strains were isolated in 1978, but strain GN79 was one of our stock cultures isolated in 1965. These penicillinases closely resembled each other, and the PSE-1 and PSE-4 enzymes produced by Pseudomonas aeruginosa, in their substrate profiles and kinetic properties for hydrolyzing various beta-lactams. However, differences were found in their molecular weights and isoelectric points which ranged from 22,000 to 27,000 and from 6.0 to 6.9, respectively. The antiserum against the purified penicillinase of N-29 cross-reacted with the enzyme of N-3 and inhibited its activity by more than 80%. The antiserum also reacted with the PSE-1 and PSE-4 enzymes. The antiserum did not react with the penicillinase from strain GN79 and the PSE-2 and PSE-3 enzymes of P. aeruginosa. Enzyme production in N-3 and N-29 was mediated by R plasmids.

Animals↗
PubMed1982

Two new slow-moving variants of human serum albumin.

Two new slow-moving variants of human serum albumin were found in members of two unrelated Japanese families. These variants, different from each other and from the slow-moving variants described previously, were designated albumin "Okinoerabu' and albumin "Akasaka'. The mode of inheritance of each variant was consistent with an autosomal codominant trait. A very rare type, homozygote for a variant, albumin "Okinoerabu', was also detected. The segregation data of albumin and Gc showed no discrepancy from the postulation of a linkage between these two loci.

Electrophoresis, Agar Gel↗
PubMed1982

Characterization of eight beta-lactamases of Gram-negative bacteria.

Eight kinds of beta-lactamases produced by gram-negative bacteria were characterized by the following properties: molecular weight, isoelectric point, pH optimum, molecular activity, immunochemical reactivity, and kinetic parameters with respect to twelve kinds of common beta-lactam antibiotics. These beta-lactamases included two types of penicillinases mediated by R plasmids and six kinds of species-specific cephalosporinases. To determine a reliable value of the kinetic parameter, Km, we introduced a continuous and acidimetric assay method of beta-lactamase activity with a pH stat.

Citrobacter↗