Biomedical subjects

T Adachi

Publications and source records attributed to T Adachi.

At least 19 recordsLinked to original sources

PubMed1992

Quantitative analysis of extracellular-superoxide dismutase in serum and urine by ELISA with monoclonal antibody.

The superoxide anion has been implicated in a wide range of diseases. The major protector against superoxide anion in the extracellular space is extracellular-superoxide dismutase (EC-SOD). EC-SOD is the major SOD isozyme in plasma and forms an equilibrium between the plasma phase and heparan sulfate proteoglycan on the surface of the endothelium. An ELISA method for the measurement of human EC-SOD with monoclonal antibody was established. The proposed method had a high sensitivity (assay range, 0.05-50 ng/ml), good recovery (recovery percentage, 96.9 +/- 5.6%) and reproducibility (within-day assay, C.V. = 8.6-10.2%; between-day assay, C.V. = 6.5-11.7%). EC-SOD levels in sera from healthy persons are clearly divided into two groups: a lower group (Group I, below 120 ng/ml, n = 146) and higher group (Group II, above 400 ng/ml, n = 10). The EC-SOD in Group I were almost normally distributed and the mean level was 55.8 +/- 18.8 ng/ml. The serum EC-SOD level assayed by ELISA correlated well with serum SOD activity. The serum EC-SOD in Group I is heterogeneous with regard to affinity for heparin-Sepharose and could be separated into three approximately equal fractions, whereas the EC-SOD in Group II is mainly one fraction with a high affinity for the column. The apparent molecular weight and carbohydrate structure of serum EC-SOD in Group II are identical to those in Group I. The high EC-SOD level in sera from some individuals may reflect the excessive stimulation of EC-SOD synthesis in vivo or the growth of selected cells in vivo, because EC-SOD is known to be expressed by a few cell types in vivo as a high-heparin-affinity subtype.

Adolescent↗

PubMed1992

[A case of retroperitoneal ganglioneuroma].

A 50-year-old woman was admitted under a diagnosis of abdominal tumor. Ultrasonography and CT scanning were performed, and a right retroperitoneal tumor was detected. Absolute curative resection was performed. The resected tumor was 13.5 x 11.5 x 9.0 cm, and histologically diagnosed as ganglioneuroma. To our knowledge, 99 cases have been reported in Japan. During a twelve-month follow-up period, the postoperative course was uneventful and no recurrence had been noted.

Female↗

PubMed1992

Stimulation of the nucleus basalis of Meynert increases cortical cerebral blood flow without influencing diameter of the pial artery in rats.

The effects of focal electrical stimulation of the nucleus basalis of Meynert (NBM) and hypercapnia on diameter of the pial artery and regional cerebral blood flow (CBF) in the parietal cortex were examined in urethane-anesthetized rats. The diameter of pial artery was measured using the video microscope and cortical CBF was measured using the laser Doppler flowmetry. Hypercapnia at 10% of end-tidal CO2 concentration caused significant increases in diameter of the pial artery and cortical CBF. Electrical stimulation of the NBM (with parameters of 200 microA, 50 Hz, 0.5 ms, for 1 min) produced a significant increase in cortical CBF, but did not influence the diameter of pial artery. The results suggest that cholinergic fibers originating in the NBM do not contribute to neural vasodilatation of the pial artery, although they induce neural vasodilation of parenchymal blood vessels which results in an increase in CBF in the parietal cortex.

Animals↗

PubMed1992

The heparin binding site of human extracellular-superoxide dismutase.

Extracellular-superoxide dismutase (EC-SOD) is a secretory glycoprotein that is major SOD isozyme in extracellular fluids. We revealed the possible structure of the carbohydrate chain of serum EC-SOD with the serial lectin affinity technique. The structure is a biantennary complex type with an internal fucose residue attached to asparagine-linked N-acetyl-D-glucosamine and with terminal sialic acid linked to N-acetyllactosamine. EC-SOD in plasma is heterogeneous with regard to heparin affinity and can be divided into three fractions: A, without affinity; B, with intermediate affinity; and C, with high affinity. It appeared that this heterogeneity is not dependent on the carbohydrate structure upon comparison of EC-SOD A, B, and C. No effect of the glycopeptidase F treatment of EC-SOD C on its heparin affinity supported the results. A previous report showed that both lysine and arginine residues probably at the C-terminal end, contribute to heparin binding. Recombinant EC-SOD C treated with trypsin or endoproteinase Lys C, which lost three lysine residues (Lys-211, Lys-212, and Lys-220) or one lysine residue (Lys-220) at the C-terminal end, had no or weak affinity for the heparin HPLC column, respectively. The proteinase-treated r-EC-SOD C also lost triple arginine residues which are adjacent to double lysine residues. These results suggest that the heparin-binding site may occur on a "cluster" of basic amino acids at the C-terminal end of EC-SOD C. EC-SOD is speculated to be primarily synthesized as type C, and types A and B are probably the result of secondary modifications. It appeared that the proteolytic cleavage of the exteriorized lysine- and arginine-rich C-terminal end in vivo is a more important contributory factor to the formation of EC-SOD B and/or EC-SOD A.

Amino Acid Sequence↗

PubMed1992

Purification and characterization of indolepyruvate decarboxylase. A novel enzyme for indole-3-acetic acid biosynthesis in Enterobacter cloacae.

Indolepyruvate decarboxylase, a key enzyme for indole-3-acetic acid biosynthesis, was found in extracts of Enterobacter cloacae. The enzyme catalyzes the decarboxylation of indole-3-pyruvic acid to yield indole-3-acetaldehyde and carbon dioxide. The enzyme was purified to apparent homogeneity from Escherichia coli cells harboring the genetic locus for this enzyme obtained from E. cloacae. The results of gel filtration experiments showed that indolepyruvate decarboxylase is a tetramer with an M(r) of 240,000. In the absence of thiamine pyrophosphate and Mg2+, the active tetramers dissociate into inactive monomers and dimers. However, the addition of thiamine pyrophosphate and Mg2+ to the inactive monomers and dimers results in the formation of active tetramers. These results indicate that the thiamine pyrophosphate-Mg2+ complex functions in the formation of the tetramer, which is the enzymatically active holoenzyme. The enzyme exhibited decarboxylase activity with indole-3-pyruvic acid and pyruvic acid as substrates, but no decarboxylase activity was apparent with L-tryptophan, indole-3-lactic acid, beta-phenylpyruvic acid, oxalic acid, oxaloacetic acid, and acetoacetic acid. The Km values for indole-3-pyruvic acid and pyruvic acid were 15 microM and 2.5 mM, respectively. These results indicate that indole-3-acetic acid biosynthesis in E. cloacae is mediated by indolepyruvate decarboxylase, which has a high specificity and affinity for indole-3-pyruvic acid.

Carboxy-Lyases↗

PubMed1992

Nitric oxide (NO) is involved in increased cerebral cortical blood flow following stimulation of the nucleus basalis of Meynert in anesthetized rats.

The effects of i.v. administration of a nitric oxide (NO) synthase inhibitor, L-NG-nitroarginine (L-NOArg), on the increase in cerebral cortical blood flow (cortical BF), following either electrical stimulation of the nucleus basalis of Meynert (NBM), whose cholinergic fibers project to the cortex, or hypercapnia with 10% CO2 inhalation, were studied in anesthetized rats. Cortical BF was measured using laser Doppler flowmetry. The threshold intensity of electrical stimulation of the NBM (0.5 ms, 50 Hz for 10 s) that induced an increase in regional cortical BF was defined as 1T. The cortical BF was increased on a stimulus intensity dependent manner at 1T-5T intensities tested. L-NOArg was administered cumulatively i.v. starting from 0.3 mg/kg, then 3 mg/kg, and 30 mg/kg. Time interval between each cumulative administration of L-NOArg was approximately 40 min. Three and 30 mg/kg of L-NOArg significant reduced the NBM stimulation-induced increase of cortical BF at intensities of 2T and 3T. The response at an intensity of 5T was reduced only by 30 mg/kg of L-NOArg to about half the control response. The reduced responses at 2T, 3T, and 5T were reversed following the i.v. administration of a physiological precursor of NO, L-arg (300 mg/kg). Inhalation of 10% CO2 for 15 s induced an increase in cortical BF which was not influenced by L-NOArg and L-Arg. These results suggest that NO is a necessary factor in the vasodilation of the cortical BF that is brought about by cholinergic fibers originating in the NBM.

Anesthesia↗

PubMed1992

Nucleotide sequence of a cDNA clone encoding a major allergenic protein in rice seeds. Homology of the deduced amino acid sequence with members of alpha-amylase/trypsin inhibitor family.

A cDNA clone of rice major allergenic protein (RAP) was isolated from a cDNA library of maturing rice seeds. The cDNA had an open reading frame (486 nucleotides) which coded a 162 amino acid residue polypeptide comprising a 27-residue signal peptide and a 135-residue mature protein of M(r) 14,764. The deduced amino acid sequence of RAP showed a considerable similarity to barley trypsin inhibitor [1983, J. Biol. Chem. 258, 7998-8003] and wheat alpha-amylase inhibitor [1981, Phytochemistry 20, 1781-1784].

Allergens↗

PubMed1992

Switching tRNA(Gln) identity from glutamine to tryptophan.

The middle base (U35) of the anticodon of tRNA(Gln) is a major element ensuring the accuracy of aminoacylation by Escherichia coli glutaminyl-tRNA synthetase (GlnRS). An opal suppressor of tRNA(Gln) (su+2UGA) containing C35 (anticodon UCA) was isolated by genetic selection and mutagenesis. Suppression of a UGA mutation in the E. coli fol gene followed by N-terminal sequence analysis of purified dihydrofolate reductase showed that this tRNA was an efficient suppressor that inserted predominantly tryptophan. Mutations of the 3-70 base pair (U70 and A3U70) were made. These mutants of su+2UGA are less efficient suppressors and inserted predominantly tryptophan in vivo; alanine insertion was not observed. Mutations of the discriminator nucleotide (A73, U73, C73) result in very weak opal suppressors. Aminoacylation in vitro by E. coli TrpRS of tRNA(Gln) transcripts mutated in the anticodon demonstrate that TrpRS recognizes all three nucleotides of the anticodon. The results show the interchangeability of the glutamine and tryptophan identities by base substitutions in their respective tRNAs. The amber suppressor (anticodon CUA) tRNA(Trp) was known previously to insert predominantly glutamine. We show that the opal suppressor (anticodon UCA) tRNA(Gln) inserts mainly tryptophan. Discrimination by these synthetases for tRNA includes position 35, with recognition of C35 by TrpRS and U35 by GlnRS. As the use of the UGA codon as tryptophan in mycoplasma and in yeast mitochondria is conserved, recognition of the UCA anticodon by TrpRS may also be maintained in evolution.

Amino Acyl-tRNA Synthetases↗

PubMed1992

Transformation of vitamin D3 to 1 alpha,25-dihydroxyvitamin D3 via 25-hydroxyvitamin D3 using Amycolata sp. strains.

To enzymatically synthesize active metabolites of vitamin D3, we screened about 500 bacterial strains and 450 fungal strains, of which 12 strains were able to convert vitamin D3 to 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] via 25-hydroxyvitamin D3 [25(OH)D3]. The conversion activity was only detected in strains belonging to the genus Amycolata among all the organisms tested. A preparative-scale conversion of vitamin D3 to 25(OH)D3 and 1 alpha,25(OH)2D3 in a 200-1 tank fermentor using A. autotrophica FERM BP-1573 was accomplished, yielding 8.3 mg 25(OH)D3/l culture and 0.17 mg 1 alpha,25(OH)2D3/l culture. A related compound, vitamin D2, could be also converted to 25-hydroxyvitamin D2 and 1 alpha,25-dihydroxyvitamin D2 using the same strain. The cytochrome P-450 of FERM BP-1573 was detected by reduced CO difference spectra in whole-cell suspensions. Vitamin D3 in the culture induced cytochrome P-450 and the conversion activity simultaneously, suggesting that the hydroxylation at C-25 of vitamin D3 and at C-1 of 25(OH)D3 originates from cytochrome P-450.

Actinomycetales↗

PubMed1992

Depending on the mode of application morphine enhances or depresses somatocardiac sympathetic A- and C-reflexes in anesthetized rats.

The effects of morphine on the reflex discharges in sympathetic efferents recorded from branches of the inferior cardiac nerve (ICN) were studied in rats anesthetized with alpha-chloralose and urethane. Somatocardiac sympathetic A- and C-reflexes were elicited by single shock electrical stimulation of myelinated (A) and unmyelinated (C) afferent fibers of the tibial nerve, respectively. Application of morphine either into the femoral vein or into the subarachnoid space of the cisterna magna enhanced both the A- and C-reflexes in a dose-dependent manner, while application of morphine into the intrathecal space of the lumbar spinal cord selectively inhibited C-reflexes. All effects of morphine were antagonized by naloxone. Application of morphine via the internal carotid artery to central nervous structures above the brainstem had no effect on the somatocardiac sympathetic reflexes. It is concluded that in the anesthetized rat morphine in a dose-dependent and naloxone-reversible manner (1) depresses spinal transmission of C-afferent activity, whereas (2) at the brainstem it enhances the transmission of somatocardiac sympathetic A- and C-reflexes.

Adrenergic Fibers↗

PubMed1992

Influence of dietary protein levels on the fate of methylmercury and glutathione metabolism in mice.

We investigated the influence of dietary protein levels on the fate of methylmercury (MeHg), the tissue glutathione (GSH) levels and the efflux rates of GSH in C57BL/6N male mice. One group of mice was fed a 7.5% protein diet (low protein diet, LPD) and the other was fed a 24.8% protein diet (normal protein diet, NPD). The cumulative amount of Hg in urine in LPD-fed mice was approximately 3.7-times lower than in NPD group during the 7 days after oral administration of MeHg (20 mumol/kg), although the fecal Hg levels were identical in the two groups. Hg concentration in kidney, liver and blood decreased time-dependently for 7 days after the administration in both groups of mice, whereas the brain levels continued to increase during this period. Tissue Hg levels in the LPD group were significantly higher than in the NPD group except for the liver. Although the hepatic GSH level in LPD-fed mice was significantly lower than in NPD-fed mice, the levels in the kidney, brain, blood and plasma were not different between the two groups. The efflux rate (mumol/g body weight per day) of hepatic GSH in LPD-fed mice was significantly lower than in the NPD group, whereas the efflux rates of renal GSH were identical in both groups. When MeHg (20 mumol/kg)-pretreated mice were injected with acivicin, a specific inhibitor of gamma-glutamyltranspeptidase, the urinary Hg levels increased by 60- and 36-fold in groups fed LPD and NPD, respectively. As a result, the difference in urinary Hg levels between the two groups disappeared with acivicin treatment. This result indicated that LPD feeding might decrease urinary Hg excretion by increasing the retention of MeHg metabolite(s) in renal cells. Thus, our present study suggested that the dietary protein status, which could modulate the metabolism of thiol compounds, played an important role in determining the fate of MeHg.

Animals↗

PubMed1992

The site of nonenzymic glycation of human extracellular-superoxide dismutase in vitro.

The secretory enzyme extracellular-superoxide dismutase (EC-SOD) has affinity for heparin and some other sulfated glycosaminoglycans and is in vivo bound to heparan sulfate proteoglycan. Nonenzymic glycation of EC-SOD, both in vivo and in vitro, is associated with a reduction in heparin affinity, whereas the enzymic activity is not affected. The glycation sites in EC-SOD are further studied in the present article. It is shown that modification of a few of the five lysyl residues of the subunits of the enzyme with trinitrobenzene sulfonic acid nearly abolishes the in vitro glycation susceptibility. From a chymotryptic digest of in vitro glycated EC-SOD, two peptides with affinity for boronate could be isolated. Amino acid sequence analysis showed that both encompassed the carboxyterminal end. epsilon-Glucitol lysine was identified in both peptides at positions 211 and 212. The primary glycation sites in EC-SOD are thus lysine-211 and lysine-212 in the putative heparin-binding domain in the carboxyterminal end.

Amino Acid Sequence↗

PubMed1992

Superoxide dismutase attenuated post-ischaemic contractile dysfunction in a myocardial xanthine oxidase deficient species.

1. We assessed the effect of polyethylene glycol conjugated superoxide dismutase (PEG-SOD) on myocardial stunning in the rabbit heart in which xanthine oxidase level is extremely low. 2. In open-chest anaesthetized rabbits, the left marginal branch of the coronary artery was occluded for 10 min and then reperfused for 30 min. A group of rabbits (PEG-SOD group) received 1000 units/kg of PED-SOD and another group (control group) was given saline 15 min before the coronary occlusion. 3. Regional systolic thickening fraction (TF) was similarly reduced to approximately -25% of baseline value during ischaemia in both groups. However recovery of TF after reperfusion was significantly better in the PEG-SOD group (n = 9) and TF at 30 min after reperfusion was 70.1 +/- 3.9% of baseline value compared with 44.9 +/- 3.4% in the control group (n = 9; P less than 0.05). Rate-pressure products, left ventricular pressure, and LV dP/dt max were not significantly different between the PEG-SOD treated and untreated control rabbits at any time during the experiment. PEG-SOD did not modify the regional myocardial blood flow (coloured microsphere method) during ischaemia/reperfusion, which was assessed by using separate groups of rabbits. 4. These findings indicate that oxygen free radicals are important in the pathogenesis of myocardial stunning in xanthine oxidase deficient hearts.

Animals↗

PubMed1992

The thermostable direct hemolysin of Vibrio parahaemolyticus is a pore-forming toxin.

The hemolytic mechanism of thermostable direct hemolysin (TDH), a possible virulence factor of Vibrio parahaemolyticus, was studied. We demonstrated that TDH acts as a "pore-forming toxin" in temperature-dependent and -independent steps. The first temperature-dependent step requires only about 1-2 min incubation at 37 degrees C and makes a "pore" with a functional diameter of approximately 2 nm. The pore size was deduced from the molecular diameter of the colloidal inhibitory polysaccharides. The formation of the pores on TDH-treated erythrocyte membranes was also demonstrated by electron microscopic examination. The second step, which is a temperature-independent lytic step, causes the erythrocytes to swell owing to a colloidal osmotic influx of water via the "pores" into cells, resulting in erythrocyte lysis (or rupture) owing to increased intracellular pressure.

Erythrocytes↗

PubMed1992

A pathologic and bacteriologic study on otitis media in swine.

A pathologic and bacteriologic study on otitis media in swine was performed on 237 swine, ranging in age from 1 day to 1 year. These 237 swine from eight selected farms were slaughtered due to unfavorable prognosis associated with clinical signs of illness. One hundred sixty-three (68.8%) of the 237 swine were found to be affected with otitis, though only a few swine showed clinical signs characteristic of the disease. One hundred fifty-one (63.7%), 53 (22.4%), and 39 (16.5%) had lesions in the middle, external, and internal ear, respectively. Of the 151 cases with otitis media, bilateral and unilateral infection accounted for 114 (75.5%) and 37 (24.5%), respectively. Only 5/53 swine with otitis externa and 6/39 swine with otitis interna failed to show otitis media. All swine with infection in the tympanic cavity had inflammatory lesions in the auditory tube. Examination of the swine grouped by age revealed that, regardless of age, incidence of otitis media was 50-70%. In swine younger than 1 month old, otitis media tended to center on the auditory tube, where a mild infiltration of neutrophils into the mucous membrane was frequent. Thereafter, otitis media increased in degree and extent with age. Forty (26.5%) of the 151 swine affected with otitis media were accompanied by a substantial amount of inflammatory exudate in the tympanic cavity and bulla. Purulent exudate was found in 20/40 (50%) swine. Severe otitis media prevailed in swine between 1 and 4 months of age, showing inspissation of a suppurative exudate in the tympanic cavity and lysis of the underlying osseous wall of the tympanic bulla with subsequent fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomyces↗

PubMed1992

Differentiation of quail myoblasts transformed with a temperature sensitive mutant of Rous sarcoma virus. I. Relationship between differentiation and tyrosine kinase of src gene product.

Quail embryonic pectoral myoblasts fuse with each other at 35.5 degrees C and 41 degrees C to essentially equal extents. When the myoblasts were transformed with a temperature-sensitive mutant of Rous sarcoma virus (ts-RSV), their fusion and biochemical processes of differentiation became temperature-sensitive: their fusion occurred at 41 degrees C, the non-permissive temperature, but not at 35.5 degrees C, the permissive temperature, suggesting that the fusion was regulated by the viral transforming gene. Fusion of the transformed cells proceeded more rapidly and synchronously than that of the parent cells at 41 degrees C, and was completely suppressed at the permissive temperature, unlike that of the parent cells. These transformed cells were used to examine the relationship between myogenic differentiation and the tyrosine kinase activity of the src gene product. In spite of the temperature sensitivity of transformation, results showed that expressions of the src gene at 35.5 degrees C and 41 degrees C were similar. However, the level of tyrosine-phosphorylated protein was decreased at 41 degrees C. Moreover, myoblast fusion could occur at 35.5 degrees C in the presence of herbimycin A, an inhibitor of the tyrosine kinase activity of the src gene product. These results indicate that the tyrosine kinase activity of the src gene product is closely associated with regulation of myogenic differentiation of the cells.

Animals↗

PubMed1992

Differentiation of quail myoblasts transformed with a temperature sensitive mutant of Rous sarcoma virus. II. Relationship of myoblast fusion with calcium and temperature.

The effects of calcium and temperature on fusion of quail embryonic myoblasts were examined using cells transformed with a temperature-sensitive mutant of Rous sarcoma virus (ts-RSV). The transformed quail myoblasts (QM-RSV) fused to form myotubes at 41 degrees C, the non-permissive temperature, but not at 35.5 degrees C, the permissive temperature. On incubation at 41 degrees C, a period of more than 10 hr was needed for the myoblasts to become fusion-competent, but calcium was not needed for development of fusion-competence. Once the cells had become competent, fusion proceeded even at 35.5 degrees C. These results suggest that the src gene product expressed at 35.5 degrees C may control the fusion of cells in the competent stage by inactivating a component(s) that is associated with fusion-competence. However, fusion of even myoblasts in the competent stage was blocked in calcium-deficient medium, suggesting that calcium is essential for the fusion, probably at a step immediately before membrane union. Unlike fusion, other biochemical processes of differentiation proceeded even in calcium-deficient medium, indicating a distinction of fusion from these other processes during myoblast differentiation.

Animals↗

PubMed1992

Purification and characterization of hamster hepatic microsomal N,O-acetyltransferase.

A microsomal N,O-acetyltransferase which activates carcinogenic arylacetohydroxamic acids was purified 75-fold from hamster liver sequentially by anion exchange column chromatography, chromatofocusing, gel filtration, and hydroxyapatite column chromatography. The purified enzyme, AT-2, was a glycoprotein with a molecular weight of 60000 and a pI value of 5.4. The N-terminal amino acid sequence of AT-2 was: 60000 and a pI value of 5.4. The N-terminal amino acid sequence of AT-2 was: Asp-Ser-Pro-Ser-Pro-Ile-Arg-Asn-Thr-His-Thr-Gly-Gln-Val-Arg-Gly-Leu-Val- His- Lys-. This sequence was highly homologous to that of the form 2 carboxylesterase of rabbit liver, but not to that of major hepatic microsomal carboxylesterases of hamster and other species. AT-2 catalyzed the hydrolysis of 4-nitrophenyl acetate and the N,O-acetyltransfer of N-hydroxy-2-acetylaminofluorene. Both enzyme activities were strongly inhibited by paraoxon, but not by iodoacetamide. These results demonstrate that this N,O-acetyltransferase is a member of carboxylesterase (EC 3.1.1.1).

Acetyltransferases↗