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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 1,459 records · Page 81Linked to original sources
PubMed1982

Studies on steroids. CLXXIX. Determination of estriol 16- and 17-glucuronide in biological fluids by high-performance liquid chromatography with electrochemical detection.

A high-performance liquid chromatographic method for the determination of estriol 16-glucuronide and 17-glucuronide in bile and urine has been developed. The electrochemical detector was found to be more superior than the UV detector with respect to selectivity and sensitivity and therefore more suitable for the determination of estrogen conjugates in biological fluids. The use of the present method revealed that both estriol 16-glucuronide and 17-glucuronide were excreted in rat bile, while only the former was present in human pregnancy urine.

Animals↗
PubMed1982

Determination of estrone sulfate in plasma by radioimmunoassay without deconjugation.

A radioimmunoassay method using highly specific antiserum without prior deconjugation has been developed for determination of estrone sulfate in human plasma. Antiserum was elicited in the rabbit by immunization with antigen in which the sulfated steroid hapten is linked to a carrier protein through the C-6 position. After treatment with Rivanol, the protein of albumin-free antiserum was covalently bound to a p-arylamine glass bead support through the cross-linkage with glutaraldehyde. A simple and reliable method for measurement of estrone sulfate which involves elimination of endogenous interferences by use of Sep-pak C18 followed by radioimmunoassay employing the antibody-glass preparation, was established and applied to peripheral plasma throughout normal pregnancy.

Animals↗
PubMed1982

Stabilization of lipoprotein lipase by endothelial cells.

Lipoprotein lipase, purified from bovine milk, lost 90% of its activity when incubated in Hanks' balanced salt solution for 5 min at 37 degrees C. Bovine pulmonary artery endothelial cells, maintained in culture, markedly stabilized this enzyme. The stabilizing factor of endothelial cells was non-dialyzable, resistant to heating at 100 degrees C and to changes in pH, and unaffected by treatments of cells with proteolytic enzymes or with heparinase (Flavobacterium heparinum enzyme). However, the stabilizing effect on lipoprotein lipase was reduced by 60-70% by the extraction of cells with chloroform/methanol (2:1). The lipid extract of the cells stabilized the enzyme, suggesting that lipid component(s) of the endothelial cells account for their stabilizing effect. Since the endothelial cell is thought to be the site of action of lipoprotein lipase, stabilization of the enzyme by this cell may play a role in its preservation and function in vivo.

Animals↗
PubMed1982

Determination of captopril in human blood by high-performance liquid chromatography with electrochemical detection.

A new method for quantitation of captopril in human blood is described. Captopril was derivatized with N-(4-dimethylaminophenyl)maleimide into the electrochemically active adduct. The derivative was separated and determined by high-performance liquid chromatography with an electrochemical detector on a reversed-phase column. The proposed method was satisfactory for determination of captopril in whole blood with respect to accuracy and precision. The detection limit of captopril thereby obtained was 10 ng/ml. The blood levels of captopril in patients orally given an official dose were measured by the present method.

Adult↗
PubMed1982

Cancer of the pancreas with hyperamylasemia.

A 66-yr-old woman had several attacks resembling relapsing acute pancreatitis with elevation of serum amylase for about three months. Obstruction of the main pancreatic duct was detected with endoscopic retrograde pancreatoductography, though no abnormality was revealed on celiac and mesenteric arteriograms. At that time she had no jaundice. Laparotomy revealed a walnut-sized tumor in the head of the pancreas compressing the main pancreatic duct. Pancreaticoduodenectomy was performed. The pathological diagnosis of the tumor was well-differentiated papillary cysto-adenocarcinoma of the pancreas. She had no attack of hyperamylasemia since the operation, and is well 2 years after the surgery. Close attention to persistent elevation of pancreatic amylase levels in serum and urine would enhance the chance of detection of small pancreatic cancers before the development of jaundice.

Aged↗
PubMed1982

Preparation of specific antiserum to estradiol 3-glucuronide.

The preparation and antigenic properties of estradiol 3-glucuronide-bovine serum albumin (BSA) conjugate in which the hapten is coupled to the carrier protein through the aminomethyl group at C-6 by glutaraldehyde, have been described. Antibody raised against the immunogen in the rabbit possessed high affinity (Ka = 3.7 x 10(9) M-1) and excellent specificity to estradiol 3-glucuronide, exhibiting no significant cross-reactivities with estrogen glucuronides except for estriol 3-glucuronide (3.64%) and no cross-reactions with free estrogens, their sulfates and other steroids.

Animals↗
PubMed1982

Preparation and antigenic properties of estriol 16-glucuronide- and estradiol 17-glucuronide-[C-6]-bovine serum albumin conjugates.

The preparation and antigenic properties of estriol 16-glucuronide-bovine serum albumin (BSA) and estradiol 17-glucuronide-BSA conjugates in which the hapten molecule is linked to the carrier protein through an (O-carboxymethyl)oxime bridge at the C-6 position on the steroid nucleus, have been described. Antibodies raised against the two immunogens in the rabbit possessed excellent specificity to estriol 16-glucuronide and estradiol 17-glucuronide, respectively, exhibiting no significant cross-reactions with estrogen glucuronides having a substituent in ring A and no cross-reactivities with free estrogens, their sulfates and related steroids.

Antibodies↗
PubMed1982

Transposon Tn3-mediated replicon fusion.

To investigate inter-replicon transposition of Tn3, we used the cosmid-phage lambda packaging system coupled with density gradient fractionation and isolated recombinant molecules of different sizes. Cosmids derived from ampicillin-resistance-transducing phage were classified into four groups: (1) cosmid-Tn3 donor cointegrates considered as Tn3 transposition intermediates, (2) similar cointegrates carrying deletions of one copy of Tn3 and of adjacent cosmid DNA sequences, (3) cosmids carrying a single Tn3 insertion, and (4) cosmids carrying two independent Tn3 insertions. Genetic and biochemical studies indicated that cosmids isolated from ampicillin-resistance transductants were derived from the authentic cosmid-Tn3 donor cointegrate intermediates.

Bacteriophage lambda↗
PubMed1982

Subcellular localization of O2- generating enzyme in guinea pig polymorphonuclear leukocytes; fractionation of subcellular particles by using a Percoll density gradient.

An iso-osmotic Percoll density gradient was applied to determine the subcellular localization of the O2- generating enzyme, NADPH oxidase, in guinea pig polymorphonuclear leukocytes (PMN). [14C]Myristate (MA) was employed as a metabolic stimulant in order to clarify whether the myristate binding site on PMN membrane was identical with the O2- generating site. The distribution pattern of the O2- generating activity of MA-activated PMN was compared with that of unactivated PMN in parallel experiments to find fractions showing an enhanced O2- generating activity (i.e., above the background values due to O2-generation by other electron-transport systems). We observed very high O2- generating activity concentrated in a single peak with MA-activated PMN but little activity was seen with unactivated PMN in the Percoll density gradient. The O2- generating activity of MA-activated PMN was consistently associated with 5'-nucleotidase activity as a membrane marker enzyme, but was not associated with lysosomal marker enzymes such as myeloper-oxidase and lysozyme. O2- generating and 5'-nucleotidase activities in the peak fraction of MA-activated PMN were increased to about six and four times those of whole cells in terms of specific activity, respectively. These results indicate that the O2- generating enzyme is located on PMN plasma membrane. Furthermore, [14C]myristate-binding activity was mainly found in the peak fraction containing O2 - generating enzyme. This suggests that [14C]myristate binds to plasma membrane, and the O2 - generating enzyme may thus be activated.

5'-Nucleotidase↗
PubMed1982

Characterization of a ColE1-like plasmid isolated from Shigella sonnei.

A multicopy plasmid, 4.7 kb in size, was isolated from Shigella sonnei and named pKY1. This plasmid produces a colicin E1-like bacteriocin (colicin E1*) in E. coli cells. The cells harboring pKY1 are immune not only to this bacteriocin but also to colicin E1, and the cells harboring Co1E1 show immunity to colicin E1* as well. Although these two plasmid DNAs have different cleavage maps and are compatible with each other, pKY1 shows partial DNA homology with ColE1 DNA. In this paper, we report the isolation and properties of several Tn3 inserted pKY1 mutants, and propose a preliminary genetic map of pKY1. It was also found that this plasmid is not capable of self-transmission and is poorly mobilized by the F factor.

Chromosome Mapping↗
PubMed1982

ColE1 vectors for direct selection of cells carrying a hybrid plasmid.

pKY2289, a ColE1::Tn3 derivative, useful for direct selection of cells carrying a hybrid plasmid, was deleted of its mobility functions and parts of the transposon including the left inverted repeat. This deletion mutant, named pKY2700 expresses low levels of colicin E1 synthesis even in recA cells. A nitrosoguanidine mutant of pKY2289 which shows a high level of constitutive colicin E1 synthesis was also deleted of the same sequences as pKY2700. The second plasmid, named pKY2800, has the same molecular weight (3.8 megadaltons) and almost the same structure as pKY2700, but produces colicin E1 at much higher levels and has a copy number 10 times higher. pKY2800 requires no colicin E1 induction for the direct selection of hybrid clones, while pKY2700 requires mitonmycin C at a concentration of 10 ng per ml. These two colE1 derivatives are useful as safe and convenient vectors for cloning DNA fragments at the cleavage sites of EcoRI, XmaI, and SstII of plasmid.

Bacteriophage lambda↗
PubMed1982

Re-examination of the ColE1 DNA regions essential for autonomous replication and their functions.

Starting from pAO3, a plasmid consisting of a quarter of colicinogenic factor E1 (ColE1) DNA, various small ColE1 derivatives were constructed by in vitro recombination and their ability to achieve autonomous replication was examined. The 436 base pair HaeIII-C fragment of pAO3 contained information for replication when it was recombined with the non-replicating Amp fragment. However, when it was connected to other DNA fragments, the resulting hybrid molecules were not isolated as plasmids. The present results indicate that the additional region of about 240 base pairs next to the HaeIII-C fragment of ColE1 is also essential for the maintenance of a plasmid state. Moreover, using various small ColE1 derivatives, the DNA region responsible for the interference and incompatibility functions of ColE1 DNAs was located. The results indicate that the interference and incompatibility functions are coded by the same ColE1 DNA segment and are not essential for the maintenance of a plasmid state.

Base Composition↗
PubMed1982

In vitro O-methylation of 4-hydroxyestrone monosulfates.

In vitro O-methylation of 4-hydroxyestrone monosulfates has been examined by means of high-performance liquid chromatography with electrochemical detection. When 4-hydroxyestrone or its 3-sulfate was incubated with rat liver homogenate in the presence of S-adenosyl-L-methionine, the 4-methyl ether was formed in twelve times larger amount than the 3-methyl ether. 4-Hydroxyestrone 4-sulfate served for O-methylation to much less extent as a substrate namely, only a small amount of the 4-methyl ether was formed. Enzymic sulfation of 4-hydroxyestrone with rat liver 105000 g supernatant fortified with adenosine 3'-phosphate 5'-phosphosulfate provided solely catechol estrogen 4-sulfates. The participation of catechol O-methyltransferase and aryl sulfatase in the formation of guaiacol estrogens has been discussed.

Animals↗