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T Uesugi

Publications and source records attributed to T Uesugi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Occurrence and antigenic heterogeneity of L-2,4-diaminobutyrate decarboxylase in Acinetobacter species.

We have previously reported that a novel enzyme, L-2,4-diaminobutyrate decarboxylase (DABA DC), which is responsible for the formation of 1,3-diaminopropane, occurs in two Acinetobacter species. The present study extends this observation to additional Acinetobacter species and strains (6 reference strains and 30 clinical isolates). Furthermore, the DABA DC protein was detected in every strain by Western blot analysis with the antiserum against the enzyme purified from A. baumannii ATCC 19606. However, only the DABA DCs in the A. calcoaceticus and Acinetobacter genospecies 3 in addition to A. baumannii strains strongly cross-reacted with the antiserum, suggesting antigenic heterogeneity among the DABA DC proteins in Acinetobacter species. Therefore, immunological testing of the DABA DC protein may provide an additional method for differentiating and identifying Acinetobacter strains.

Acinetobacter↗
PubMed1994

[Detection of cytomegalovirus (CMV) antigen for rapid diagnosis and monitoring of CMV diseases in AIDS].

Ten to forty percent of the patients with acquired immunodeficiency syndrome (AIDS) develop sight- or life-threatening cytomegalovirus (CMV) infections. In some patients with AIDS, CMV is detected in the bronchoalveolar lavage fluid (BALF), urine, and other specimens, even when there are no symptoms of CMV disease. An indicator of active CMV infection is needed to facilitate the diagnosis of CMV disease in patients with AIDS or HIV infection and the evaluation of the efficacy of subsequent treatment. The present study was conducted during the period from 1993 to 1994. The subjects consisted of three patients with AIDS and a confirmed diagnosis of CMV disease (one case of retinitis, one case of gastrointestinal disease and one case of pneumonia), and five HIV-positive patients in whom CMV associated disease was ruled out. Those patients were monitored occasionally for the following parameters of active CMV infection and disease: expression of CMV antigen in the nucleus of polymorphonuclear leukocyte (CMV antigenemia), as it was determined with a monoclonal antibody against a lower matrix protein (p65); infectious CMV detected by shell vial method; CMV DNA detected by PCR; anti-CMV antibody titer; and histological findings. CMV p65 antigen was detected in the leukocytes of both the peripheral blood and BALF during the early phase of CMV disease in three out of three cases of the CMV disease group, and this antigen became negative in two out of two cases who responded to the therapy. All the five patients in the CMV-related-disease-negative group were negative for CMV antigenemia.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Opportunistic Infections↗
PubMed1992

High-performance liquid chromatographic determination of sulphobromophthalein and its conjugates.

A simple, sensitive and selective high-performance liquid chromatographic method for the determination of sulphobromophthalein and its mercaptide conjugates in rat bile was developed. These pigments, which have an absorption maximum at 580 nm in alkaline solution, were separated isocratically on an alkali-resistant ODS column by paired-ion chromatography. Analysis of bile samples obtained after intravenous administration of sulphobromophthalein to rats showed the presence of at least twenty peaks of metabolites, of which thirteen were identified and seven quantified.

Animals↗
PubMed1991

Organic anion transport study in mutant rats with autosomal recessive conjugated hyperbilirubinemia.

The EHBR is a mutant rat strain with congenital conjugated hyperbilirubinemia bred from a Sprague-Dawley rat. Transport of conjugated bilirubin, indocyanine green, and tetrabromosulfophtalein from liver to bile is severely impaired in these rats. Serum bilirubin amounts to 6.0 +/- 0.05 mg/dl (n = 4) in adult rats, with 97% conjugates. The bile flow is reduced to about 65% of the control group, whereas total bile acid in 10-min bile samples is similar. Liver histology of 10 week-old rats revealed neither intracellular pigmentation nor architectural abnormalities.

Animals↗
PubMed1991

Decrease in the specific forms of cytochrome P-450 in liver microsomes of a mutant strain of rat with hyperbilirubinuria.

Eisai-hyperbilirubinuria rats (EHBR) is a mutant originated from Sprague Dawley rats. The activities of UDP-glucuronyltransferase and drug metabolizing enzymes in EHBR were compared with those in Sprague Dawley rats as the control. The activity of aniline hydroxylase was significantly increased in liver microsomes of EHBR whereas the activity of ethylmorphine N-demethylase was found to be significantly decreased in EHBR as compared to control rats. In addition, the activity of testosterone 7 alpha-hydroxylase was increased in EHBR whereas the activity of testosterone 6 beta-hydroxylase was significantly decreased in EHBR as compared to control rats. Western blot analysis of liver microsomes of EHBR with antibodies to P-450IA2, P-450IIB1, P-450IIC11 and P-450IIIA2 showed that the amounts of P-450IIB1 and P-450IIIA2 in liver microsomes were significantly lower in EHBR than in control rats. These results indicated the form-specific alteration in the amounts of cytochrome P-450 in liver microsomes of EHBR.

Aniline Hydroxylase↗
PubMed1990

Degradation and metabolism of indocyanine green: high-pressure liquid chromatographic analysis.

Degradation of indocyanine green solution by exposure to light was studied by high-pressure liquid chromatography. Indocyanine green in an aqueous medium exposed to light changed rapidly into an unknown product. The plasma clearance rate and the biliary excretion rate of the unknown product were much slower than those of indocyanine green. Spectrophotometric scan revealed that the unknown product had almost the same absorption spectrum as indocyanine green. Therefore, if degraded indocyanine green solution were to be used in a liver function test, the clearance of indocyanine green assayed by spectrophotometry would apparently be much lower than that of undegraded indocyanine green. According to fast atom bombardment mass spectrometry, the molecular weight of the unknown product was 723, whereas that of indocyanine green was 775. The analysis of rat bile after injection of indocyanine green by high-pressure liquid chromatography revealed that about 1% of the administered indocyanine green was metabolized in the rat liver.

Animals↗
PubMed1985

Study of bilirubin metabolism by high-performance liquid chromatography: stability of bilirubin glucuronides.

The stabilities of bilirubin (BR) glucuronide, monoglucuronide (BMG), and diglucuronide (BDG) were studied under various conditions by HPLC. In aqueous media, BMG showed a pronounced lability and was easily transformed into equimolar BDG and BR. It was proved by direct analysis of tetrapyrrole isomers that BDG and BR were formed from dipyrrole exchange of BMG molecules. All reducing agents examined (sodium ascorbate, cysteine, GSH, dithiothreitol, NADH, and NADPH) suppressed the transformation of BMG into BDG and BR. Bovine serum albumin and rat liver cytosol fractions also stabilized BMG strongly. BDG was fairly stable in aqueous media as compared with BMG. When BMG was incubated both with and without liver plasma membranes (N2 fraction) from Wistar rats, the formation rates of BDG and BR in both incubation mixtures were exactly the same. The composition of BDG and BR isomers was the same in both mixtures. Also, heat denaturation of the plasma membranes did not affect formation rates. Moreover, the reaction was completely inhibited by sodium ascorbate. These findings indicate that rat liver plasma membranes have no enzyme activity for BDG formation from BMG.

Animals↗
PubMed1984

The effect of Sudan III on drug metabolizing enzymes.

We have examined the induction of drug metabolizing enzymes in rat liver microsomes by azo dye, 1-(p-phenylazophenylazo)-2-naphthol (Sudan III). Marked increases were observed in the levels of cytochrome P-448 as well as in p-nitroanisole O-demethylase (p-NAD), amaranth (AR) and neoprontosil reductases (NPR) and 7-ethoxycoumarin O-deethylase (ECD) activities. On the other hand, aminopyrene N-demethylase activity was not significantly increased. Further, induced ECD activity was inhibited 90% by a specific antibody against cytochrome P-448 while the inhibition observed with an antibody against cytochrome P-450 was less than 25%. Simultaneous administration of Sudan III and 3-methylcholanthene (3-MC) induced cytochrome P-448 up to a level brought about by either Sudan III or 3-MC treatment alone. In contrast, Sudan III did not induce cytochrome P-448 in the 3-MC insensitive DBA/2 mouse. Solubilized microsomes from Sudan III-treated rats showed an identical sodium dodecyl sulfate polyacrylamide gel electrophoretic (SDS-PAGE) pattern with those from 3-MC-treated animals. It is concluded that the cytochrome P-448 induced in liver by Sudan III is very similar to that induced by 3-MC. Sudan III also induced UDP-glucuronyltransferase activity towards 1-naphthol and estradiol. It did not induce NADPH-cytochrome c reductase, nor any of the enzymes which constitute the microsomal electron transport chain except for cytochrome P-448.

Animals↗
PubMed1982

New melanogenesis and photobiological processes in activation and proliferation of precursor melanocytes after UV-exposure: ultrastructural differentiation of precursor melanocytes from Langerhans cells.

Photobiological processes involving new melanogenesis after exposure to ultraviolet (UV) light were experimentally studied in C57 black adult mice by histochemistry, cytochemistry, and autoradiography. The trunk and the plantar region of the foot, where no functioning melanocytes were present before exposure, were exposed to UV-A for 14 consecutive days. Both regions revealed a basically similar pattern for new melanogenesis which involved an activation of precursor melanocytes. Essentially all of "indeterminate" cells appeared to be precursor melanocytes, the fine structure of which could be differentiated even from poorly developed Langerhans cells. New melanogenesis was manifested by 4 stages of cellular and subcellular reactions of these cells as indicated by histochemistry of dihydroxyphenylalanine (dopa) and autoradiography of thymidine incorporation: (a) an initial lag in the activation of precursor melanocytes with development of Golgi cisternae and rough endoplasmic reticulum followed by formation of unmelanized melanosomes (day 0 to 2); (b) synthesis of active tyrosinase accumulated in Golgi cisternae and vesicles with subsequent formation of melanized melanosomes in these cells (day 3 to 5); (c) mitotic proliferation of many of these activated cells, followed by an exponential increase of new melanocytes (day 6 to 7); and (d) melanosome transfer with differentiation of 10 nm filaments and arborization of dendrites, but without any significant change in the melanocyte population (day 8 to 14). The melanosome transfer was, however, not obvious until after 7 days of exposure. The size of newly synthesized melanosomes was similar to that of tail skin where native melanocytes were present before exposure.

Animals↗
PubMed1982

Effect of 1-m-tolueneazo-2-naphthol on hepatic drug metabolism. I. Induction of cytochrome P-448.

Treatment of rats with 1-m-tolueneazo-2-naphthol (mTAN) caused marked increase in liver weight, microsomal 7-ethoxycoumarin O-deethylase activity and cytochrome P-450 content, with 2 nm hypochromic shift in CO difference spectrum. It decreased NADPH-cytochrome c reductase and aminopyrine N-demethylase activities. Treatment of 3-methylcholanthrene nonresponsive DBA/2 strain of mice with this azo compound resulted in a limited (1.5 fold) induction of cytochrome P-450 compared to 2.5 fold induction in responsive C57BL/6 strain of mice. The major species of liver microsomal P-450 from m-TAN treated rats was purified. This species of P-450 has a Solet peak at 416 nm in the absolute oxidized spectrum, 410 nm in the reduced spectrum and 447 nm in the spectrum of ferrous P-450-CO complex. This species of P-450 is spectrally indistinguishable from cytochrome P-448 induced by 3-methylcholanthrene. As an inducer of cytochrome P-450, m-TAN is similar to 3-methylcholanthrene with its potency equals to or exceeding that of 3-methylcholanthrene. It differs in that it causes marked increase in liver weight and decrease in NADPH-cytochrome c reductase activity.

Animals↗
PubMed1982

Effect of 1-m-tolueneazo-2-naphthol on hepatic drug metabolism. II. Induction of UDP-glucuronyltransferase.

Effect of potent cytochrome P-448 inducer, 1-m-tolueneazo-2-naphthol (m-TAN) on hepatic microsomal UDP-glucuronyl-transferase (UDPGT) activity was studied. The UDPGT activity reached the maximum level on the fifth day after either a single injection or consecutive daily administrations. The UDPGT activities towards p-nitrophenol, 1-naphthol and chloramphenicol were increased up to 6,2.5 and 1.8 folds of control levels respectively, in microsomes from m-TAN treated rats. 3-Methylcholanthrene, on the other hand, caused 4 and 2 fold increase in UDPGT activities towards p-nitrophenol and 1-naphthol, respectively, but did not cause significant increase in UDPGT activity towards chloramphenicol. It is concluded that m-TAN is a new potent inducer of UDPGT activity with its potency exceeding that of 3-methylcholanthrene and the pattern of induction, a little different from that of 3-methylcholanthrene.

Animals↗