Biomedical subjects

J Fujii

Publications and source records attributed to J Fujii.

At least 19 recordsLinked to original sources

PubMed2002

Office blood pressure variability as a predictor of acute myocardial infarction in elderly patients receiving antihypertensive therapy.

Larger variability of office blood pressure (BP) was reportedly associated with a higher risk of stroke or mortality from all causes. In the present study, we focused on the relationship of variability of office BP and occurrence of acute myocardial infarction (MI). We registered 139 patients receiving antihypertensive therapy for more than 1 year who experienced first-ever episode of MI at the age of 60 years or over. At least two sex- and age-matched (+/- 5 years) control patients were registered for every MI patient. Average systolic and diastolic BP during the 12-month period prior to the occurrence of MI, or the time of registration in the case of control patients, was similar in both patient groups. The office BP variability was evaluated by calculating the variation coefficient (VC) of BP. VC of diastolic BP was significantly higher in the MI patients (10.0 +/- 4.0%) compared with the control patients (8.8 +/- 3.4%). VC of systolic BP was not different between the MI and the control patients. Multiple logistic analysis revealed the relationship of the VC for office diastolic BP to the occurrence of MI was significant after adjustment for BP level, age, gender, body mass index, serum total cholesterol concentrations, diabetes mellitus, and current smoking. In conclusion, larger long-term variability of office diastolic BP during antihypertensive therapy is a predictor of MI.

Age Distribution↗

PubMed2001

Active glycation in neurofibrillary pathology of Alzheimer disease: N(epsilon)-(carboxymethyl) lysine and hexitol-lysine.

Advanced glycation end products are a diverse class of posttranslational modifications, stemming from reactive aldehyde reactions, that have been implicated in the pathogenesis of a number of degenerative diseases. Because advanced glycation end products are accelerated by, and result in formation of, oxygen-derived free radicals, they represent an important component of the oxidative stress hypothesis of Alzheimer disease (AD). In this study, we used in situ techniques to assess N(epsilon)-(Carboxymethyl)lysine (CML), the predominant advanced glycation end product that accumulates in vivo, along with its glycation-specific precursor hexitol-lysine, in patients with AD as well as in young and aged-matched control cases. Both CML and hexitol-lysine were increased in neurons, especially those containing intracellular neurofibrillary pathology in cases of AD. The increase in hexitol-lysine and CML in AD suggests that glycation is an early event in disease pathogenesis. In addition, because CML can result from either lipid peroxidation or advanced glycation, while hexitol-lysine is solely a product of glycation, this study, together with studies demonstrating the presence of 4-hydroxy-2-nonenal adducts and pentosidine, provides evidence of two distinct oxidative processes acting in concert in AD neuropathology. Our findings support the notion that aldehyde-mediated modifications, together with oxyradical-mediated modifications, are critical pathogenic factors in AD.

Adult↗

PubMed2001

Immunohistochemical study of glutathione reductase in rat ocular tissues at different developmental stages.

Glutathione, which is found in high levels in eye tissues, is involved in multiple functions, including serving as an antioxidant and as an electron donor for peroxidases. Although the activities of enzymes related to glutathione metabolism have been reported in the eye, the issue of which cells produce these proteins, where they are produced and at what levels is an important one. Glutathione reductase, an enzyme which recycles oxidized glutathione by transferring electrons from NADPH, was localized immunohistochemically in adult rat eye in this study. The reductase was distributed in the corneal and conjunctival epithelia, corneal keratocytes and endothelium, iridial and ciliary epithelia, neural retina, and retinal pigment epithelium. In addition, it was highly expressed in ganglion cells, which are responsible for transmitting photophysiological signals from the retina to the higher visual centres. To clarify the correlation of glutathione reductase expression and oxidative stress, the enzymatic activity and the level of protein expression at the pre- and postnatal stages was examined. Expression of the enzyme was detected first in the ganglion cell layer of a late prenatal stage, and appeared in the inner plexyform layer after birth. Along with an increasing differentiation between the inner nuclear and outer nuclear layers, glutathione reductase expression became detectable in the outer plexyform layer. Pigment epithelial cells were positively stained only after birth. Expression was also detected in the lens epithelium from the prenatal to early postnatal stages although its level was low in the adult lens. Collectively, these data, except for lens epithelia, suggest the pivotal role of glutathione reductase in recycling oxidized glutathione for the protection of the tissues against oxidative stress, which is caused by eye opening accompanied by the initiation of various ocular processes, such as accession of light and transduction of the photochemical signal.

Animals↗

PubMed2001

Augmented expression of peroxiredoxin VI in rat lung and kidney after birth implies an antioxidative role.

A family of proteins with thioredoxin (TRx)-dependent peroxidase activity, referred to as peroxiredoxins (PRx), has been identified in many species. The sixth member of this family, PRxVI, contains only one conserved cysteine residue, while other members contain additional cysteines. We have isolated a cDNA for rat PRxVI and constructed a large scale baculovirus system to produce the recombinant protein. The protein was purified by a simple two-step procedure utilizing ion-exchange and gel-filtration chromatography. The purified PRxVI exhibited a low level of glutathione-dependent peroxidase but not TRx-dependent activity. PRxVI expression was the highest in lung, followed by brain, kidney, heart, testis, etc. as judged by Northern and Western blot analyses using a rabbit antibody to the purified PRxVI. Immunohistochemical analyses showed strong staining in the epithelium of the bronchus and bronchioles in lung and in the epithelial cells of kidney tubules. In addition, Sertoli cells in testis and islet of Langerhans cells in pancreas were strongly stained. The developmental changes of PRxVI expression in lung and kidney were low in the prenatal stage but induced postnatally. Moreover, intraperitoneal administration of chloroform induced PRxVI mRNA in kidney. When the distribution and the induced expression of PRxVI under conditions of oxidative stress are considered, a physiological role of it as an antioxidative enzyme is indicated.

Amino Acid Sequence↗

PubMed2001

Possible involvement of the membrane-bound form of peroxiredoxin 4 in acrosome formation during spermiogenesis of rats.

Peroxiredoxins are novel peroxidases that exhibit divergent biological functions. The fourth member, Prx4, is synthesized with a signal sequence and, after processing, secreted as a 27-kDa form in most tissues. A 31-kDa Prx4 which corresponds to the unprocessed, membrane-bound form is found only in testis. This study was undertaken in order to investigate the role of the membrane-bound Prx4 during spermiogenesis in rats. The Prx4 transcript was observed in testes at 14 days of age, the age before puberty, and its level increased only slightly during aging. Only the secretable form of Prx4 was present before 30 days of age, but the membrane-bound Prx4 became detectable in adult testes, although sum of the two forms appeared to be the same after 21 days old. While weak immunoreactivity to the Prx4 antibody was detected in spermatogenic cells for all ages, a strong immunoreactivity was observed in the elongating spermatid and residual body of adult testis. Prx4 was present in the lumen of the endoplasmic reticulum, Golgi bodies, and the perinuclear space in young rat testes. However, the localization of Prx4 was restricted to membranes of the acrosomal vesicle of the elongated spermatid and was not detected in spermatozoon. Once spermiogenesis is accomplished, vesicles containing the membrane-bound Prx4 were released into the residual body, along with residual membranous components. Thus the conversion of the soluble form to the membrane-bound form may have a role in the acrosome formation during vesicular reorganization during spermiogenesis.

Acrosome Reaction↗

PubMed2001

Expression of a Y-box protein, YB2/RYB-a, precedes protamine 2 expression during spermatogenesis in rodents.

Y-box binding proteins, a large family of proteins, are involved in a variety of functions. The present study describes the expression of YB2, a rat Y-box binding protein, and/or RYB-a, an alternatively spliced product of the YB2 gene during spermatogenesis. YB2/RYB-a is thought to be the rat orthologue of mouse Y-box protein 3 (MSY3). An antibody which recognizes YB2/RYB-a was developed and applied in an immunochemical study of rat and mouse testes. We also carried out an in-situ hybridization study and Northern blot analysis of YB2/RYB-a and protamine 2 mRNA expression. Both YB2/RYB-a mRNA and the proteins appeared in prepubertal mouse testes, prior to the expression of the mouse protamine 2 mRNA. The mRNA and protein were present at high levels in spermatocytes, decreased in round to elongated spermatids, and were absent in spermatozoa. Since the protamine 2 mRNA was present at high levels in round and elongating spermatids, the proposed function of the YB2/RYB-a protein as a translational repressor of the mRNA was supported in mouse. The level and localization of YB2/RYB-a mRNA and protein expression in the rat testis was comparable to that in mouse testis, although rat testis is known to express a very low level of protamine 2, but is also likely to affect the expression of other proteins (including protamine 1) during spermatogenesis.

Animals↗

PubMed2001

Roles of N-terminal active cysteines and C-terminal cysteine-selenocysteine in the catalytic mechanism of mammalian thioredoxin reductase.

Mammalian thioredoxin reductase [EC 1.6.4.5], a homodimeric flavoprotein, has a marked similarity to glutathione reductase. The two cysteines in the N-terminal FAD domain (-Cys59-x-x-x-x-Cys64-) and histidine (His472) are conserved between them at corresponding positions, but the mammalian thioredoxin reductase contains a C-terminal extension of selenocysteine (Sec or U) at the penultimate position and a preceding cysteine (-Gly-Cys497-Sec498-Gly). Introduction of mutations into the cloned rat thioredoxin reductase gene revealed that residues Cys59, Cys64, His472, Cys497, and Sec498, as well as the sequence of Cys497 and Sec498 were essential for thioredoxin-reducing activity. To analyze the catalytic mechanism of the mammalian thioredoxin reductase, the wild-type, U498C, U498S, C59S, and C64S were overproduced in a baculovirus/insect cell system and purified. The wild-type thioredoxin reductase produced in this system, designated as WT, was found to lack the Sec residue and to terminate at Cys497. A Sec-containing thioredoxin reductase, which was purified from COS-1 cells transfected with the wild-type cDNA, was designated as SecWT and was used as an authentic enzyme. Among mutant enzymes, only U498C retained a slight thioredoxin-reducing activity at about three orders magnitude lower than SecWT. WT, U498C, and U498S showed some 5,5'-dithiobis(2-nitrobenzoic acid)-reducing activity and transhydrogenase activity, and C59S and C64S had substantially no such activities. These data and spectral analyses of these enzymes suggest that Cys59 and Cys64 at the N-terminus, in conjunction with His472, function as primary acceptors for electrons from NADPH via FAD, and that the electrons are then transferred to Cys497-Sec498 at the C-terminus for the reduction of oxidized thioredoxin in the mammalian thioredoxin reductase.

Animals↗

PubMed2001

Alteration of glutathione reductase expression in the female reproductive organs during the estrous cycle.

The enzyme glutathione reductase (GR) recycles oxidized glutathione (GSSG) by converting it to the reduced form (GSH) in an NADPH-dependent manner. A specific antibody raised against recombinant rat GR was used to localize the protein in the female reproductive organs during the estrous cycle in the rat. In the ovary, the strongest reactivity to the antibody was observed in oocytes, followed by granulosa cells, corpus luteum, and interstitial cells. A strongly positive reaction was also observed mainly in the oviduct epithelia, uterine epithelia, and endometrial gland in the reproductive tract. Oviducts contained the highest GR activity. The GR activity of uterus during metestrus was about twice as high as that for other stages of the cycle. The levels of GR proteins in the tissues roughly matched the activities. The expression of the GR mRNA was highest during metestrus. Because GSH is known to increase gamete viability and the efficiency of fertility, GR, which is expressed in these tissues, is predicted to play a pivotal role in the reproduction process as a source of GSH.

Animals↗

PubMed2001

Toxicity of Shiga toxin 1 in the central nervous system of rabbits.

The action of Shiga toxin (Stx) on the central nervous system was examined in rabbits. Intravenous Stx1 was 44 times more lethal than Stx2 and acted more rapidly than Stx2. However, Stx1 accumulated more slowly in the cerebrospinal fluid than did Stx2. Magnetic resonance imaging demonstrated a predominance of Stx1-dependent lesions in the spinal cord. Pretreatment of the animals with anti-Stx1 antiserum intravenously completely protected against both development of brain lesions and mortality.

Animals↗

PubMed2001

Pharmacokinetic differences between lansoprazole enantiomers and contribution of cytochrome P450 isoforms to enantioselective metabolism of lansoprazole in dogs.

The purpose of this study was to evaluate the pharmacokinetics of lansoprazole enantiomers and contribution of cytochrome P450 enzymes to enantioselective metabolism in dogs. The mean Cmax and area under the curve (AUC) values of (+)-lansoprazole were 4-5 times greater than those of (-)-lansoprazole following oral administration of 30-mg racemic lansoprazole to dogs. The CLtot/F values of (+)-lansoprazole were significantly smaller than those of (-)-lansoprazole (p<0.05). The mean unbound fraction of (-)-lansoprazole was significantly greater than that of the (+)-lansoprazole. The amount of (+)-lansoprazole remaining was significantly greater than that of the (-)-lansoprazole after incubation of racemic lansoprazole in dog liver microsomes. When the effects of ticlopidine or ketoconazole on the metabolism of lansoprazole were studied using dog liver microsomes, ticlopidine significantly inhibited the formation of 5-hydroxylansoprazole, but not another metabolite, lansoprazole sulfone; however ketoconazole significantly inhibited formation of both metabolites. When the amount of (+)- and (-)-enantiomers remaining was measured in the presence and absence of ticlopidine, the amount of (+)-lansoprazole was significantly greater than that of the (-)-lansoprazole. On the other hand, there was no significant difference between the amount of (+)- and (-)-enantiomers remaining in combination with ketoconazole. These results suggest that the enantioselective pharmacokinetics of lansoprazole enantiomers are probably ascribable to their enantioselective protein binding and/or metabolism, and among the cytochrome P450 enzymes, CYP3A contributed to the enantioselective metabolism of lansoprazole.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2001

Medication management skill and regimen compliance are deteriorated in the elderly even without obvious dementia.

We investigated whether regimen comprehension deteriorated in the elderly patients who did not suffer from obvious dementia. Eligible patients were ambulatory elderly patients who did not show any signs of dementia and could visit our outpatient clinic by themselves. 138 patients (age: 43-89, 75 males and 63 females, underlying diseases: hypertension, hyperlipidemia, arrhythmia etc.) were tested with a regimen comprehension scale (RCS: Jpn J Geriat 1997; 34: 209-214). The differences in scores among individuals increased with age. Scores of 5 or less in the RCS were recorded in 10 out of 69 patients aged 65 or more, but no such scores were recorded in younger patients (p < 0.01). The 60 patients who scored less than full marks were classified into two groups, the T-group (tutored by pharmacists), and a Non Tutored group. RCS was tested again in both groups. Only in the T-group (n = 28), did the second scores increase significantly (from 7.2 +/- 0.9 to 8.6 +/- 2.0 (m +/- SD); p < 0.01) after tutorial by pharmacists. Comparing the 7 patients who obtained an RCS score of 5 or less and age- and gender-matched controls who got full marks, there was no difference in the HDS-R test. These results suggest that even in elderly patients who did not show any signs of dementia, the regimen comprehension deteriorated with age, and tutorials in medication protocols were considered to be effective.

Adult↗

PubMed2001

Profiles of patients who control the doses of their antihypertensive drugs by self-monitoring of home blood pressure.

The present study profiled patients who control doses of antihypertensive drugs by themselves based on self-monitoring of their blood pressure (self-controllers). A total of 1,028 consecutive outpatients who were taking antihypertensive drugs and who were attending the cardiovascular outpatient clinic of our institute responded to a questionnaire in 1998. They were asked how often they measured their blood pressure, how often they missed taking their medication, and whether or not they had a chance to adjust the doses of antihypertensive drugs by themselves based on self-monitored blood pressure. The frequency of self-controlling of antihypertensive drugs was also examined in 918 patients on antihypertensive drugs in 1997. In 1997, 23 of 918 patients (2.5%) were self-controllers, and 26 of 1,028 patients (2.5%) were self-controllers in 1998. The frequency of home blood-pressure measurement was significantly greater in self-controllers than in the remaining patients (non self-controllers) (p<0.01). The prevalence of proteinuria was significantly less in the former than in the latter. Prior to the start of antihypertensive drugs, blood pressure was significantly lower for the self-controllers (154.4+/-3.8/96.4+/-1.4 mmHg) than for the non self-controllers (169.3+/-0.7/101.7+/-0.4 mmHg) (p<0.001). Clinically measured blood pressures did not differ significantly between the self-controllers and non self-controllers. Thus, about 2.5% of patients on antihypertensive drugs controlled their drug doses by themselves based on self-monitoring of their blood pressure. These patients were characterized by having a milder form of hypertension and by more frequent home blood-pressure measurement than non self-controllers.

Aged↗

PubMed2001

[An autopsied case of marked cardiac hypertrophy due to multifactorial heart disease in an 85 year-old man who had been socially active].

An autopsied 85-year-old man had suffered from a mild form of diabetes mellitus since the age of 67 and had experienced the first episode of heart failure with arapid ventricular rate of atrial fibrillation at the age of 72. He had remained socially active until he died suddenly of ventricular fibrillation, although he had complications of aortic regurgitation at the age of 76 and later mitral regurgitation at the age of 80. Chest roentgenograms showed gradual increase in the cardiothoratic ratio which reached 68.1% at the final stage. Autopsy revealedmarked left ventricular hypertrophy with a heart weight of 580 g, degeneration ofaortic valves, thickening of mitralvalve cusps and moderate coronary atherosclerosis without ischemic myocardial lesions. There were no specific lesions suggestive of primary cardiomyopathies on microscopic observations and the lesions of both aortic and mitral valves were not significant enough to explain the clinical findings of aortic and mitral regurgitation. Because the pathological examination failed to identify a single disease which was responsible for the marked cardiachypertrophy, we eventually reached the conclusion that the cardiac hypertrophy developed based on a multifactorial heart disease.

Activities of Daily Living↗

PubMed2000

A pivotal role of Zn-binding residues in the function of the copper chaperone for SOD1.

A Cu chaperone for SOD1 (CCS) is required for the incorporation of copper ion into the protein. To investigate the roles of the conserved metal-binding residues in CCS, we introduced amino acid substitutions into human CCS and examined the function of the mutant CCS by transforming a mutant yeast strain, SY2950, which lacks the lys7 gene, a yeast orthologue of the mammalian CCS. Mutant CCS in which amino acid residues His147 and Asp167 were substituted by Ala exhibited a decreased ability to complement the growth of SY2950 under Lys-deficient conditions. This is because the mutations made the human CCS function in a less efficient manner, especially under metal-restricted conditions, leaving Cu,Zn-SOD in an apo-form. Since the His and Asp residues are both responsible for binding Zn which would serve to maintain the folded structure, the structural integrity supported by the coordinated Zn ion would be essential for CCS function.

Amino Acid Sequence↗

PubMed2000

Redox capacity of cells affects inactivation of glutathione reductase by nitrosative stress.

Glutathione reductase (GR) plays a pivotal role in maintaining glutathione (GSH) in its reduced form. We have isolated a cDNA for rat GR and constructed a baculovirus system to produce recombinant GR on a large scale. This protein was purified by simple, two-step chromatographic procedure using DE52 and 2',5'-ADP Sepharose. Tissue distributions of GR were examined by Northern and Western blotting with a rabbit antibody to purified GR. GR was expressed in the order of reactivity; kidney, colon, liver, stomach, etc. Western blot analysis showed that both the cytosolic and the mitochondrial fractions of liver homogenate gave immunoreactive bands of similar size. This indicates that the same gene products exist in these fractions. Since nitric oxide (NO) produced under inflammatory conditions causes nitrosative stress and affects the redox states of surrounding tissues, we investigated the effects of NO donors on the enzymatic activities of purified GR. S-nitrosoglutathione (GSNO), 3-morpholinosydnonimine N-ethylcarbamide (SIN-1), and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) at 1 mM gave 39, 15, and 12% inhibitions, respectively. In RAW 264.7 cells the GR activity was reported to be inhibited by GSNO. In A549 cells, however, no such change in the activity, protein levels and mRNA of GR was noted. Since these cells have a much higher redox capacity than RAW 264.7 cells as judged by GR activity and thioredoxin reductase activity it wound minimize cellular damage, including inactivation of GR caused by nitrosative stress.

Amino Acid Sequence↗

PubMed2000

Detection of an Amadori product, 1-hexitol-lysine, in the anterior horn of the amyotrophic lateral sclerosis and spinobulbar muscular atrophy spinal cord: evidence for early involvement of glycation in motoneuron diseases.

Glycation is a series of non-enzymatic reactions initiated by addition of reducing sugars to epsilon-amino group of lysine residues and alpha-amino group of the N terminus of proteins, leading to the formation of advanced glycation end products (AGE). It is thought to be involved in aging and various neurodegenerative conditions. In the present study using anti-1-hexitol-lysine (1-HL) antibody, Amadori product, an early glycation product, was detected in axonal spheroids in the anterior horn of amyotrophic lateral sclerosis and in atrophic neurons of spinobulbar muscular atrophy (SBMA, Kennedy disease with abnormally expanded triplet repeats in androgen receptor gene) but not in other regions of the central nervous system. Furthermore, Amadori product was undetectable in the tissues from age-matched controls. Thus, 1-HL formation could not reflect physiological aging.

Amyotrophic Lateral Sclerosis↗

PubMed2000

Pyruvate secreted by human lymphoid cell lines protects cells from hydrogen peroxide mediated cell death.

Reactive oxygen species (ROS) released from polymorphonuclear leukocytes and macrophages could cause DNA damage, but also induce cell death. Therefore inhibition of cell death must be an important issue for accumulation of genetic changes in lymphoid cells in inflammatory foci. Scavengers in the post culture medium of four lymphoid cell lines, lymphoblastoid cell lines (LCL), Raji, BJAB and Jurkat cells, were examined. Over 80% of cultured cells showed cell death 24 h after xanthine (X)/xanthine oxidase (XOD) treatment, which was suppressed by addition of post culture medium from four cell lines in a dose-dependent manner. H2O2 but not O2*- produced by the X/XOD reaction was responsible for the cytotoxity, thus we used H2O2 as ROS stress thereafter. The H2O2-scavenging activity of post culture media from four cell lines increased rapidly at the first day and continued to increase in the following 2-3 days for LCL, Raji and BJAB cells. The scavenging substance was shown to be pyruvate, with various concentrations in the cultured medium among cell lines. Over 99% of total pyruvate was present in the extracellular media and less than 1% in cells. alpha-Cyano-4-hydroxycinnamate, a specific inhibitor of the H+-monocarbohydrate transporter, increased the H2O2-scavenging activity in the media from all four cell lines via inhibition of pyruvate re-uptake by cultured cells from the media. These findings suggest that lymphoid cells in inflammatory foci could survive even under ROS by producing pyruvate, so that accumulation of lymphoid cells with DNA damage is possible.

Cell Death↗

PubMed2000

Gain in functions of mutant Cu,Zn-superoxide dismutases as a causative factor in familial amyotrophic lateral sclerosis: less reactive oxidant formation but high spontaneous aggregation and precipitation.

Eight mutant Cu,Zn-superoxide dismutases (SODs) related to familial amyotrophic lateral sclerosis (FALS) were produced in a baculovirus/insect cell expression system and their molecular properties in terms of hydroxyl radical formation and aggregation were compared with the wild-type enzyme. Treatment of the enzymes with Chelex 100 resin decreased Cu contents as well as SOD activities in all mutant Cu,Zn-SODs, indicating that the affinities of the enzymes for copper ion were decreased. Contrary to previous reports, all the mutant Cu,Zn-SODs exhibited less reactive oxidant producing ability in the presence of hydrogen peroxide than the wild-type enzyme. Both SOD activities and their reactive oxidant forming correlated well with the copper ion content of the molecules. In addition, the proteins spontaneously aggregated and were precipitated by simple centrifugation at 12,000g for 20 min in keeping their enzyme activities. Since hyaline inclusions found in FALS patients with SOD1 mutations contained components which were reactive to anti-Cu,Zn-SOD antibody, a primary reaction caused by mutant SOD1 may be attributed to their propensity to form aggregates. Aggregated but still active mutant SOD1 would be expected to mediate the formation of reactive oxygen species and nitrosylation in a more condensed state.

Amyotrophic Lateral Sclerosis↗