Biomedical subjects

K Asayama

Publications and source records attributed to K Asayama.

At least 19 recordsLinked to original sources

PubMed1995

Increased Cu/Zn superoxide dismutase-like immunoreactivity in the swollen axons of rats intoxicated chronically with beta,beta'-iminodipropionitrile.

Demonstration of a genetic linkage between the Cu/Zn superoxide dismutase (SOD1) gene and familial amyotrophic lateral sclerosis (ALS) has aroused interest in the role of SOD1 in spinal motoneuronal death. We used chronically beta,beta'-iminodipropionitrile (IDPN)-intoxicated rats as a model of ALS and investigated SOD1 changes in the spinal cord by immunocytochemical and in situ hybridization techniques. Compared with control rats, SOD1-like immunoreactivity (SOD1-IR) increased in swollen axons of the proximal spinal roots, but not in motoneuronal and dorsal root ganglion neuronal cell bodies where SOD1 gene transcription did not increase. The present data indicate that treatment with IDPN induces accumulation of SOD1 in the swollen axons by blocking slow axonal flow, suggesting the possibility that increased SOD1-IR in ALS is induced by axonal flow blockade.

Amyotrophic Lateral Sclerosis↗

PubMed1995

Development of a sandwich enzyme-linked immunosorbent assay for the determination of human heart type fatty acid-binding protein in plasma and urine by using two different monoclonal antibodies specific for human heart fatty acid-binding protein.

We have developed a sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of human heart type fatty acid-binding protein (H-FABP) in human plasma and urine using the combination of two distinct monoclonal antibodies (MAbs) directed against human H-FABP purified from human heart muscle. The total assay time of the ELISA is practically much shorter than that of the competitive enzyme immunoassay (EIA) we previously reported. The immunoreactive mass of human H-FABP was specifically measured using a horseradish peroxidase (HRPO)-labeled anti-human H-FABP MAb as an enzyme-linked MAb, and anti-human H-FABP MAb immobilized on the polystyrene microtiter plate as a solid-phase MAb, and purified human H-FABP as standard materials. The assay range of the ELISA was 0-250 ng/ml of plasma and urine. The ELISA yielded a coefficient of variation of less than 10% in inter- and intra-assays, and the good linearity was obtained in dilution test using clinical samples. Anticoagulants, except sodium fluoride and a high concentration of hemoglobin and bilirubin, did not interfere with the assay of plasma samples. A high concentration of hemoglobin, bilirubin and immunoglobulin, and contamination with seminal plasma did not interfere with the assay of urine samples. The average recovery of purified human H-FABP added to human plasma and urine samples was 98.5% and 97.0%, respectively. Myoglobin and myosin did not crossreact in the ELISA. The minimum detection limit of the ELISA was 1.25 ng/ml. The immunoreactive masses of human H-FABP in plasma and urine samples, obtained from one hundred normal healthy subjects were quantified by the sandwich ELISA. The normal mean (+/- SD) level of human H-FABP mass in plasma was 3.65 +/- 1.81 ng/ml, and that in urine was 3.20 +/- 2.70 ng/ml. In conclusion, this sandwich ELISA is a useful tool for the sensitive and precise determination of human H-FABP in human plasma and urine, and it may be used specifically for clinical investigation and diagnosis of myocardial injury.

Antibodies, Monoclonal↗

PubMed1995

Cerebellar superoxide dismutase expression in Menkes' kinky hair disease: an immunohistochemical investigation.

This comparative immunohistochemical study deals with the expression of the cytosolic Cu/Zn-binding and mitochondrial Mn-dependent superoxide dismutases (SODs) in the cerebella of five patients with Menkes' kinky hair disease (MKHD) and five age-matched controls. Several cell types, including Purkinje cells and reactive astrocytes, of all MKHD patients examined were intensely stained by an antibody to Mn SOD, but not by an anti-Cu/Zn SOD antibody. By contrast, the cells of the five controls reacted very weakly or not at all with the anti-Mn SOD antibody, but were strongly reactive with the antibody to Cu/Zn SOD. These results suggest that the increased Mn SOD immunoreactivity in MKHD reflects enzyme induction as a protective mechanism against the highly toxic superoxide anion generated under the disease conditions.

Adolescent↗

PubMed1995

Cu/Zn superoxide dismutase-like immunoreactivity is present in Lewy bodies from Parkinson disease: a light and electron microscopic immunocytochemical study.

Copper-zinc superoxide dismutase (SOD1)-like immunoreactivity has been demonstrated in Lewy body-like inclusions (LIs) in brain tissues from patients with familial and sporadic amyotrophic lateral sclerosis. Using immunocytochemistry, we studied Lewy bodies (LBs), the original inclusions from which the term LI was derived, in five patients with Parkinson disease (PD). Surprisingly, many LBs were immunostained by an antibody against SOD1. There were two types of staining pattern: a diffuse pattern, and a peripheral pattern with an unstained core. An immunoelectron microscopic study demonstrated that the immunoreactive products were restricted to the fibrillary profiles, sparing the unstructured core. Our results showed that SOD1-like immunoreactivity occurred frequently in LBs and LIs, suggesting that a common cytopathological process is responsible for the formation of LB-type neuronal intracytoplasmic inclusions. Our results also suggest that SOD1 plays a role in the neurodegeneration associated with PD.

Aged↗

PubMed1995

The functional limitations of tetraplegic hands for intermittent clean self-catheterisation.

Since the introduction of intermittent self-catheterisation by Lapides et al, low pressure voiding methods have been adopted actively in our centre. A retrospective review of 47 patients with cervical spinal cord injury (CSCI) who performed independent (self) clean intermittent catheterisation (CIC) on discharge is presented. Their functional abilities were evaluated by both the Frankel and the Zancolli scales. Fourteen out of the 47 patients could manage independent CIC, 17 assisted CIC, nine tapped or voided voluntarily, two were discharged with a diaper, one with a suprapubic catheter, and four with an indwelling catheter. According to Frankel's classification, four patients were in A category, four in B, one in C and five in D among the group of complete CIC. C6A/C5B (right/left hand) by Zancolli's classification was the highest level of ability for all these 14 patients; and one patient (a 30-year-old male, Frankel B classification) could manage independent CIC with the aid of our special device. However, the practical limit of functional hands for independent CIC appeared to be about C6B1.

Adolescent↗

PubMed1995

Relationships between biochemical abnormalities and anthropometric indices of overweight, adiposity and body fat distribution in Japanese elementary school children.

OBJECTIVE: To determine the anthropometric indices linked to the biochemical risk factors for atherosclerosis in Japanese obese elementary school children, ages ranging from 6 to 12 years. DESIGN: Cross-sectional study of obese children based on fasting blood samples. SETTING: Outpatient clinic of University Hospital. SUBJECTS: 65 consecutive patients with simple obesity (38 boys and 27 girls), and age-matched controls, 184 boys and 205 girls. MAIN OUTCOME MEASURES: Percent obesity and body mass index as indices of being overweight; percent body fat and the sum of four skinfold thicknesses as indices of adiposity; waist-to-hip circumference ratio and waist-to-thigh circumference ratio as indices of body fat distribution. The anthropometric indices were standardized by calculating standard deviation scores based on data from control children. RESULTS: In the obese boys, all six anthropometric indices studied correlated closely with serum biochemical indices, and strong correlations were observed among the indices of overweight, adiposity and body fat distribution. In contrast, only the indices of body fat distribution, not those of overweight or of adiposity, were correlated with serum biochemical indices in the obese girls. No relationship was found between the indices of body fat distribution and the other anthropometric indices in the obese girls. Thus, the profile of the obese girls differed from that of their male counterparts. CONCLUSION: The results suggest that body fat distribution is related to certain biochemical complications of childhood obesity, and that androgyny in fat patterns induces metabolic derangements in children.

Adipose Tissue↗

PubMed1994

Demonstration of glutathione peroxidase in rat liver peroxisomes and its intraorganellar distribution.

Earlier, we reported that rat liver peroxisomes contain Cu-Zn superoxide dismutase (J. Biol. Chem. 267, 6870), thereby suggesting a new antioxidant role for this organelle in free radical metabolism. In this study, we report for the first time that mammalian peroxisomes also contain glutathione peroxidase. Using highly purified rat liver peroxisomes isolated by Nycodenz gradient, we found that peroxisomes contain glutathione peroxidase which shows enzymatic activity with different substrates such as hydrogen peroxide, cumene hydroperoxide, and t-butyl hydroperoxide. This activity could be inhibited in vitro by mercaptosuccinate. Western blot analysis revealed that peroxisomes from control and ciprofibrate-treated livers show immunoreactive bands with antibodies raised against glutathione peroxidase. The intraperoxisomal distribution of glutathione peroxidase was investigated by using peroxisomal membrane and matrix proteins. The results revealed that glutathione peroxidase is a matrix enzyme. The presence of glutathione peroxidase in peroxisomes provides an alternate enzyme system responsible for the degradation of organic peroxides and the degradation of H2O2 under conditions in which catalase is inactivated (e.g., ischemia-reperfusion and endotoxemia). These findings suggest that glutathione peroxidase in peroxisomes may play a novel role in the cellular antioxidant responses to various oxidative stress conditions.

Animals↗

PubMed1994

Purification and immunoelectron microscopic localization of cellular glutathione peroxidase in rat hepatocytes: quantitative analysis by postembedding method.

To measure quantitatively the intracellular distribution of cellular glutathione peroxidase (GPX) in rat hepatocytes, ultrathin sections were stained by a postembedding immunogold technique. GPX had a specific activity of 1670 Units/mg protein, and was purified 2050-fold from rat liver by means of heat denaturation, ammonium sulfate fractionation, and a series of chromatographic procedures including thiol-Sepharose 4B. The purified GPX was shown to be electrophoretically pure, and was a homotetramer of 22 kDa subunits. Monospecific polyclonal antibodies were raised in rabbits by immunization. By immunoblot analysis, both the light mitochondrial the and cytosolic fractions of rat liver homogenate gave a single band with an identical mobility to that of the purified enzyme. Under the light microscope, hepatocytes showed nuclear staining and granular cytoplasmic staining, corresponding to certain intracellular structures. The labeling density (number of gold particles/microns 2) for GPX obtained by immunoelectron microscopy was 11.9 in the nuclei, 19.6 in mitochondria, 3.32 in peroxisomes, 1.95 in lysosomes, and 9.81 in the cytoplasmic matrix. These results suggest that cellular GPX is present in various compartments of rat hepatocytes, and that the GPX occurs in relatively higher amounts in mitochondria.

Animals↗

PubMed1994

Serum antioxidant status in streptozotocin-induced diabetic rat.

To determine whether decrease in serum antioxidants contributes to the increased oxidative stress, we measured the antioxidant activity (AOA), total peroxyl radical-trapping antioxidant parameter (TRAP), and their component individual antioxidants in the serum of diabetic rats. AOA was assayed as the ability of serum to inhibit lipid autoxidation in brain homogenates. TRAP was assayed as the ability to delay lipid peroxidation induced by an azo initiator. Antioxidants measured were ceruloplasmin, unsaturated iron binding capacity (UIBC) and albumin as components of AOA; and uric acid, protein sulfhydryl and alpha-tocopherol as components of TRAP. AOA was decreased markedly in the diabetics due to the decrease in ceruloplasmin, UIBC and albumin. On the other hand, the directly measured TRAP in the diabetics was unaltered. Uric acid and alpha-tocopherol were increased in the diabetics. However, decrease in unidentified scavengers offset the increase brought about by those antioxidants These results suggest that the decreased metal binding capacity contributes to the increased oxidative stress in the diabetic rats.

Animals↗

PubMed1994

Increased serum levels of C-terminal parathyroid hormone-related protein in different diseases associated with HTLV-1 infection.

We analyzed the serum levels of C-terminal parathyroid hormone-related protein (C-PTHrP) in asymptomatic carriers of human T lymphotropic virus type 1 (HTLV-1) and patients with three HTLV-1 related diseases; adult T-cell leukemia (ATL), HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) and HTLV-1 uveitis (HU). Serum C-PTHrP levels were significantly elevated in HTLV-1-infected individuals, irrespective of whether they were symptomatic or asymptomatic, when compared with that of the seronegative controls. In ATL patients, a good correlation was demonstrated between the serum C-PTHrP level and serum calcium or lactic dehydrogenase (LDH) level. Thus the elevated serum C-PTHrP level could be a characteristic marker of HTLV-1 carrier state, and the determination of its level in ATL patients could be useful for the assessment of the prognosis and as one of the tumor markers. The determination of the serum level of C-PTHrP in various stages of the HTLV-1 carrier state would help to understand the mechanism of the development of hypercalcemia in ATL.

Adult↗

PubMed1994

[Minimum required number of anesthetists for general hospitals (41-1300 beds) in Japan--analysis of questionnaire, 1992].

BACKGROUND: We have elucidated the deficit of anesthetists in general hospitals excluding university hospitals by assessing the results of questionnaires from 204 institutions in Japan. METHODS: Answers to the questionnaire were computed in average, maximum, and minimum values, using MS-Excel soft ware for statistical analysis. RESULTS: The 204 hospitals were classified into 4 groups; G-1(46)-more than 640 beds, G-2(53)-more than 500 beds, G-3(53)-more than 360 beds, and G-4(52)-less than 359 beds, respectively (parenthesis indicate hospital numbers). The number of cases of anesthesia performed by anesthesiologists were 2055(G-1), 1516(G-2), 1177(G-3) and 959(G-4), respectively. The number of anesthetists per operating table were as follows; 0.62(G-1), 0.62(G-2), 0.58(G-3) and 0.74(G-4), but remarkably low compared to the number of operating theater nurses: 5.49(G-1), 2.96(G-2), 2.82(G-3) and 3.07(G-4). Moreover, the number of emergency cases were as follows; 235(G-1), 187(G-2), 134(G-3) and 125(G-4), respectively. In prolonged surgery over 6 hours, patients were anesthetized with an exchange system or two anesthetists system in 74% of the institutions in G-1. Also, 28-50% of anesthetists in the 4 groups were concerned with intensive care medicine and 0.94-1.54 anesthetists worked in pain clinics with combined operation-theater tasks 1.37-2.49 days per week. In G-1-G-4 institutions, we found that anesthesia cases per year were equivalent to 5 times their bed numbers. CONCLUSION: We concluded that the number of anesthetists should be at least 50% of that of operation-theater nurses. Without increasing anesthesiologists, we cannot expect sophisticated medical care in the 21st century.

Anesthesiology↗

PubMed1993

Immunohistochemical study of copper-zinc and manganese superoxide dismutases in the lungs of human fetuses and newborn infants: developmental profile and alterations in hyaline membrane disease and bronchopulmonary dysplasia.

To determine the late gestational development of copper-zinc (CnZn) and manganese (Mn) superoxide dismutases (SOD) in human lung, immunohistochemical localization was performed for each SOD. The lung samples were taken from five aborted fetuses, four fetuses in which intrauterine death occurred, one full-term neonate, two premature infants with hyaline membrane disease and one premature infant with bronchopulmonary dysplasia (BPD). Morphometry was performed, and the percent area of positive staining was computed. The bronchial epithelium was intensely stained from the early stages of gestation (i.e. 17 weeks), while the staining intensity for both CuZnSOD and MnSOD in the peripheral airways increased gradually during lung development. The mean percent area of the staining for CuZn-SOD and MnSOD from 16 to 38 weeks was increased 30-fold and 8-fold, respectively, and further increases were observed postnatally. CuZnSOD staining was markedly decreased in lungs with respiratory disorders. However, proliferating type II pneumocytes were intensely stained for MnSOD in the BPD lungs, making the staining area 3-fold larger than that in the control lungs. These results clearly depict age-related increases in staining for both CuZnSOD and MnSOD and an alteration in SOD distribution associated with neonatal respiratory disorders.

Bronchopulmonary Dysplasia↗

PubMed1993

Antioxidants in the serum of children with insulin-dependent diabetes mellitus.

To determine whether alteration in serum antioxidant status is related to the increased oxidative stress as a cause of diabetic angiopathy, we measured both the antioxidant activity (AOA) and total peroxyl radical-trapping antioxidant parameter (TRAP), and their component individual antioxidants in serum of children with insulin-dependent diabetes mellitus (IDDM). The AOA was measured as the ability to inhibit lipid autoxidation in brain homogenates. TRAP was assayed as the ability to delay lipid peroxidation induced by an azo initiator. Antioxidants measured were ceruloplasmin, transferrin, and albumin as components of AOA; and ascorbic acid, uric acid, protein sulfhydryl, and alpha-tocopherol as components of TRAP. Serum AOA appeared to be decreased in the diabetics in relation to poor glycemic control, corresponding to the decrease in transferrin and albumin. Serum haptoglobin level was also decreased in the diabetics. Similarly, the directly measured TRAP value was decreased in the diabetic serum mainly due to the decreased contribution of unidentified chain-breaking antioxidants, despite the increase in ascorbic acid and alpha-tocopherol. The decrease in both types of antioxidant activity in the diabetic serum, as new findings, suggests that a defective serum antioxidant status contributes to the increased oxidative stress in IDDM.

Adolescent↗

PubMed1992

Demonstration of Cu-Zn superoxide dismutase in rat liver peroxisomes. Biochemical and immunochemical evidence.

In this study, by using highly purified rat liver peroxisomes, we provide evidence from analytical cell fractionation, Western blot, and immunocytochemical analysis that Cu-Zn superoxide dismutase is present in animal peroxisomes. Treatment with ciprofibrate, a peroxisome proliferator, increased the peroxisomal superoxide dismutase activity by 3-fold with no effect on mitochondrial activity but a marked decrease in cytosolic superoxide dismutase activity, further supporting that besides cytosolic and mitochondrial localization, Cu-Zn superoxide dismutase is present in peroxisomes also. Demonstration of superoxide dismutase in peroxisomes suggests a new role for this organelle in pathophysiological conditions, such as ischemia-reperfusion injury.

Animals↗

PubMed1992

Proliferation of myocardial peroxisomes in experimental rat diabetes: a biochemical and immunocytochemical study.

Myocardial peroxisomes were investigated in normal and diabetic rats. Catalase and acyl-CoA oxidase activities were increased in the diabetic rat heart and immunoblot analysis showed that both enzyme proteins were markedly enhanced in diabetic heart homogenates. After immunoenzyme staining, catalase and acyl-CoA oxidase were localized in fine granules in the myocardium, which were increased in number in diabetic rats. The numerical density of the granules stained for catalase was increased 1.7 times and that for acyl-CoA oxidase 1.8 times, compared with controls. Protein A-gold labeling for catalase and acyl-CoA oxidase was present in myocardial peroxisomes. The labeling density for both enzymes was increased in diabetic rats by 1.6 times for catalase and 1.5 times for acyl-CoA oxidase, compared with controls. The results indicate that myocardial peroxisomes are increased in the diabetic rat and that this proliferation is accompanied by an increase in catalase and acyl-CoA oxidase activities.

Acyl-CoA Oxidase↗

PubMed1992

Effect of dexamethasone on antioxidant enzymes in fetal rat lungs and kidneys.

To determine if an enhancement in the fetal antioxidant enzyme (AOE) system by maternal dexamethasone (DEX) is specific to organ and dose, the lung and kidney of pups, whose mother received DEX (0.2 or 2 mg/kg) twice, were obtained on days 19 and 20 of gestation. Low-dose DEX increased the four AOE in the day-19 lung, but not in day-20 lung. High-dose DEX decreased the copper-zinc superoxide dismutase (SOD) and glutathione peroxidase in the lungs. Thus, the DEX-induced maturation of lung AOE is dependent on dose and timing. DEX enhanced the four AOE in the day-19 kidney at both doses. In the day-20 kidney, DEX enhanced the manganese SOD at the low dose and also catalase at the high dose, suggesting that DEX accelerates the maturation of kidney AOE as well.

Animals↗

PubMed1992

Immunohistochemical localization of superoxide dismutases in fetal and neonatal rat tissues.

We investigated the developmental profile of copper-zinc and manganese superoxide dismutase (CuZnSOD and MnSOD) in tissue sections obtained from fetal (Day 12 to 21 of gestation) and neonatal (Day 0 and 6) rats. Tissues were stained immunohistochemically with specific antisera against the respective rat SODs. There was a general trend towards richness of SODs in the epithelial linings and metabolically active sites, although differential distribution between the two SODs also existed. At Day 12 of gestation, immunoreactivity for both SODs was detected in the cardiomyocytes but not in other tissues. Hepatocytes expressed CuZnSOD at Day 14 and MnSOD at Day 17. By Day 18 CuZnSOD was detected in the epithelial cells of the gastrointestinal tract, respiratory tract, pancreatic islets, kidneys, and adrenals. These tissues exhibited MnSOD staining at Day 19. CuZnSOD occurred in the epithelia of the thyroid, thymus, and salivary glands at Day 19, while MnSOD was seen at Day 21. The increase in intensity of the staining for SODs occurred no later than postnatal Day 0, indicating that most tissues accumulated SODs during late gestation. Breathing atmospheric oxygen during early extrauterine life did not appreciably intensify the SOD staining. These results suggest that perinatal increase in SODs occurs as a general mechanism of preparation for birth.

Animals↗

PubMed1991

Effect of diabetes mellitus induced by streptozotocin on renal superoxide dismutases in the rat. A radioimmunoassay and immunohistochemical study.

Two forms of superoxide dismutase, CuZn-SOD and MnSOD, have been investigated in the kidneys of streptozotocin-induced diabetic rats using both radio-immunoassay and immunoenzyme staining. The rats were killed 2, 8 and 12 weeks after the induction of diabetes mellitus and the kidneys excised. Two weeks after the induction of diabetes, the kidneys were hypertrophied because of the proliferation of renal tubular epithelium. However, the total CuZnSOD content of the kidneys did not increase and, because of the epithelial proliferation, the CuZnSOD concentration in each proximal tubular cell was decreased. Armanni-Ebstein lesions were found in the distal tubules 8 and 12 weeks after the induction of diabetes. The cells in these lesions were intensely stained for CuZnSOD, suggesting an adaptive response to the enhanced oxidative stress. The MnSOD staining in the thick ascending limbs of Henle's loops was enhanced in the diabetic kidneys, while that in the cortical tubules was unaltered. MnSOD was assumed to increase in response to hypermetabolism associated with the proliferation of renal tubules. This was most marked in the cells which were rich in mitochondria, again suggesting an adaptive response to enhanced oxidative stress induced by diabetes mellitus. The glomeruli of both the diabetic and control groups were not stained for SODs, and no significant microscopic change was found even 12 weeks after the induction of diabetes mellitus.

Animals↗