Search PubMed⌕ Search

Biomedical subjects

Y Noda

Publications and source records attributed to Y Noda.

At least 91 records · Page 5Linked to original sources
PubMed2000

Gliclazide scavenges hydroxyl and superoxide radicals: an electron spin resonance study.

The role of reactive oxygen species in diabetes and its complications are well known. Two therapeutic agents commonly used in the treatment of diabetes are the sulfonylureas gliclazide and glibenclamide. These drugs effectively reduce blood sugar in non-insulin-dependent diabetes mellitus, by augmenting insulin release. Gliclazide is known to be a general free radical scavenger as shown by its inhibition of o-dianisidine photo-oxidation. In this study, the effects of gliclazide and glibenclamide on free radicals were examined in vitro, using electron spin resonance spectroscopy. Superoxide radical (O2*-) generated from the hypoxanthine-xanthine oxidase system or hydroxyl radical (OH*) generated via the Fenton reaction were analyzed as spin adducts of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). Gliclazide scavenged O2*- and OH* in a dose-dependent manner whereas glibenclamide was without effect. These findings suggest that gliclazide is not only effective in reducing blood sugar, but may also be beneficial as a result of inhibition of lipid and protein denaturation, which is believed to lead to the development of diabetic complications.

Electron Spin Resonance Spectroscopy↗
PubMed2000

Effects of sigma receptor agonists on the impairment of spontaneous alternation behavior and decrease of cyclic GMP level induced by nitric oxide synthase inhibitors in mice.

In this study, we investigated the involvement of the interaction between sigma receptors and the nitric oxide/cyclic GMP pathway in short term memory in mice, assessed through spontaneous alternation behavior in a Y-maze. N(G)-Nitro-L-arginine methyl ester and 7-nitro indazole, both nitric oxide synthase inhibitors, impaired the spontaneous alternation behavior. These impairments were attenuated by (+) SKF 10,047 and (+) pentazocine, sigma(1) receptor agonists. Further, the sigma(1) receptor antagonist, NE-100, reversed the improvements made by sigma receptor agonists. Cyclic GMP levels and nitric oxide synthase activity in the hippocampus were reduced by treatment with N(G)-nitro-L-arginine methyl ester. The suppressive effects of N(G)-nitro-L-arginine methyl ester on the cyclic GMP levels were reversed by co-treatment with (+) SKF 10,047, but the decline in nitric oxide synthase activity was not. These results suggest that the nitric oxide/cyclic GMP pathway in the hippocampus is responsible for spontaneous alternation behavior in a Y-maze. Further, the ameliorating effects of (+) SKF 10,047 on the impairment of spontaneous alternation behavior may be mediated through activation of guanylate cyclase, but not nitric oxide synthase in the hippocampus of mice.

Analgesics, Opioid↗
PubMed2000

Attenuation of the development of morphine dependence/tolerance by nefiracetam: involvement of adenosine 3':5'-cyclic monophosphate system.

Biochemical changes such as intracellular cAMP and Ca(2+) underlying morphine dependence and tolerance have been suggested. Therefore, we investigated the effects of nefiracetam (N-(2, 6-dimethyl-phenyl)-2(2-oxo-1-pyrrolidinyl) acetamide), which increases intracellular cAMP and Ca(2+) levels, on the development of morphine dependence and tolerance. Mice administered morphine (6 or 20 mg kg(-1)) twice daily for 5 days, showed withdrawal symptoms (jumping, diarrhea and body weight loss) after naloxone challenge (5 mg kg(-1)), indicating morphine dependence. Furthermore, tolerance to the analgesic effect of morphine was observed in these mice. Co-administration of nefiracetam (5 or 10 mg kg(-1)) with morphine during the pretreatment period, significantly reduced the signs of withdrawal symptoms, moreover, the tolerance was significantly attenuated. Elevation of cAMP levels in the cortex was observed in morphine-dependent mice, but not in mice co-administered nefiracetam. Acute administration of nefiracetam shows no effect on the withdrawal symptoms and the analgesic effect in morphine-naive mice. Theophylline (3 or 10 mg kg(-1)) tended to attenuate and enprofylline (10 or 30 mg kg(-1)) significantly attenuated the development of morphine dependence and tolerance. These findings suggest that co-administration of nefiracetam or compounds, which increase the cAMP level, may be a useful strategy for attenuating the development of morphine dependence and tolerance in the clinic.

Animals↗
PubMed2000

Role of nociceptin systems in learning and memory.

This article summarizes our recent finding that the nociceptin system is involved in the regulation of learning and memory. The nociceptin-knockout mice show greater learning ability in the water maze task, an enhanced latent learning in the water finding task, better memory in the passive avoidance task, and further, larger long-term potentiation in the hippocampal CA1 region than wild-type mice. Nociceptin itself induces an impairment of passive avoidance task in wild-type mice, which is reversed by naloxone benzoylhydrazone (NalBzoH). Thus, the nociceptin system seems to play negative roles in learning and memory, and NalBzoH may act as a potent antagonist for the nociceptin receptor.

Animals↗
PubMed2000

An autopsy case of atypical adrenoleukomyeloneuropathy in childhood.

Adrenoleukomyeloneuropathy (ALMN) usually occurs in adulthood, it being extremely rare in childhood. We reported a quite atypical clinical case of ALMN as a variant of adrenoleukodystrophy (ALD). The onset was at 5 years 7 months and ataxia was the major symptom. His condition progressed rapidly to a vegetative state within 1 year. At the age of 11 years and 11 months he died of pneumonia and an autopsy was performed. We herein reported the neuropathological findings in this rare case. The autopsy revealed marked atrophy with diffuse demyelination and astrogliosis throughout the cerebrum, cerebellum and brainstem. Massive degeneration of the pyramidal tracts and loss of neurons were also seen in the spinal cord. The adrenal cortex showed marked atrophy with a striated cytoplasm in ballooned cells. These findings include pathological characteristics of both ALD and adrenomyeloneuropathy (AMN), suggesting ALMN. However, diffuse demyelination with gliosis in the cerebrum and cerebellum is quite atypical for ALMN. They might explain his atypical clinical course, especially the early onset of the disease with ataxia and rapid deterioration.

Adrenoleukodystrophy↗
PubMed2000

Neurosteroids ameliorate conditioned fear stress: an association with sigma receptors.

Mice exhibited a marked suppression of motility (conditioned fear stress) when placed in an environment in which they had previously received an electric footshock. This conditioned fear stress response was dose-dependently attenuated by neurosteroids such as dehydroepiandrosterone sulfate (DHEAS; 25 and 50 mg/kg, s.c.) and pregnenolone sulfate (PREGS; 10-50 mg/kg, s.c.), and by a putative sigma(1) receptor agonist, (+)-N-allylnormetazocine ((+)-SKF-10,047; 3 and 6 mg/kg, s.c.). However, progesterone (PROG; 10-50 mg/kg, s.c. ) and allopregnanolone (5 and 20 mg/kg, s.c.) had no effect on this stress response. The attenuating effects of DHEAS (50 mg/kg, s.c.), PREGS (50 mg/kg, s.c.), and (+)-SKF-10,047 (6 mg/kg, s.c.) were reversed by NE-100 (5 mg/kg, i.p.), a sigma(1) receptor antagonist and PROG (5 or 10 mg/kg, i.p.). When DHEAS (25 mg/kg) was co-administered with (+)-SKF-10,047 (3 mg/kg) at doses that do not affect the conditioned fear stress response by themselves, motor suppression was significantly attenuated. In mice showing the conditioned fear stress response, the serum concentration of DHEAS was lower than that in non-shocked mice. These results suggest that the attenuating effects of DHEAS and PREGS on the conditioned fear stress response are mediated via sigma(1) receptors and that PROG has a sigma(1) receptor antagonistic property. Further, the endogenous DHEAS may be involved in the expression of conditioned fear stress response in mice.

Animals↗
PubMed2000

Repeated phencyclidine treatment induces negative symptom-like behavior in forced swimming test in mice: imbalance of prefrontal serotonergic and dopaminergic functions.

Repeated treatment with phencyclidine (PCP) prolonged the immobility time in a forced swimming test, compared with saline treatment, this behavioral change being regarded as avolition which is one of the negative symptoms of schizophrenia. In the present study, we investigated an involvement of serotonergic (5-HTergic) and dopaminergic systems in PCP-induced enhancement of immobility in mice, since an alteration in 5-HTergic and dopaminergic systems has been hypothesized in schizophrenia. The enhancing effect of PCP on the immobility in a forced swimming test was attenuated by clozapine, risperidone and olanzapine, which have serotonin (5-HT) and dopamine receptor antagonistic properties. These attenuating effects were significantly antagonized by a 5-HT(2) receptor agonist, (+/-)-2,5-dimethoxy-4-iodamphetamine (DOI) without affecting the immobility itself. (-)Sulpiride at a low dose and methylphenidate reversed the PCP-induced enhancement of immobility whereas pimozide, chlorpromazine and levomepromazine had no effect. There was no difference in the frequency of DOI-induced head twitches, which are mediated via 5-HT(2) receptors, between PCP- and saline-treated mice following the forced swimming test, indicating no functional changes in post-synaptic 5-HT(2) receptors. 5-HT utilization in the prefrontal cortex was increased, but dopamine utilization was decreased in mice showing PCP-induced enhancement of immobility. These results suggest that the enhanced effect of PCP on the immobility is mediated by imbalance of 5-HTergic and dopaminergic systems in the prefrontal cortex and could be used as a model of the negative symptoms of schizophrenia.

Animals↗
PubMed2000

Acid load during total parenteral nutrition: comparison of hydrochloric acid and acetic acid on plasma acid-base balance.

The effects of hydrochloric acid and acetic acid on the plasma acid-base balance were investigated in four rabbits receiving parenteral nutrition. Hyperchloremic metabolic acidosis was observed only in the animals receiving total parenteral nutrition (TPN) whose pH was adjusted with hydrochloric acid. The observed acidosis was due to an excess of hydrogen ions with chloride ions as judged by the plasma-base excess and urinary net-acid excess and not by the infusion of solution having a high titratable acidity. The hydrogen ion released from the acetic acid added to TPN is consumed by the metabolism of the acetate ion and thus does not contribute to the net hydrogen-ion load. A reduction in the chloride load by using acetic acid to adjust the pH of the TPN solution when it is formulated can be safely achieved and prevents acidosis.

Acetic Acid↗
PubMed2000

Pulsed magnetic fields enhance nitric oxide synthase activity in rat cerebellum.

The effect of pulsed magnetic fields on nitric oxide synthase (NOS) activity in the rat brain was investigated. Sprague-Dawley rats (male, 200-250 g body weight) brain were dissected regionally, and the crude enzyme solutions were treated with pulsed DC, AC or static DC magnetic fields at 0 degrees C for 1 h. After exposure, NOS activity was measured as nitrite and nitrate levels generated from incubation with arginine, CaCl(2) and beta-nicotinamide adenine dinucleotide phosphate. Under these experimental conditions, neither AC nor static DC field treatment showed any significant change in NOS activity. A significant increase in NOS activity was observed in the cerebellum (111.2+/-2.0%, P<0.05, five separate experiments) for a 1 Gauss (0.1 mT) pulsed DC field. Under the same experimental condition, only a slight change or no effect was observed in the hippocampus, cortex, medulla oblongata, hypothalamus, striatum and midbrain. These studies suggest that pulsed magnetic fields result in a different effect on NOS activity in the cerebellum of the rats.

Journal Article↗
PubMed2000

Magnetic fields and lipoic acid influence the respiratory burst in activated rat peritoneal neutrophils.

When rat (Sprague-Dawley, male) peritoneal neutrophils are exposed to 60 Hz, 1 Gauss, magnetic fields and activated by phorbor 12-myristate 13-acetate they undergo an enhanced respiratory burst (S. Roy, Y. Noda, V. Eckert, M.G. Traber, A. Mori, R.P. Liburdy, L. Packer, The phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst in rat peritoneal neutrophils is increased by a 0. 1 mT (60 Hz) magnetic field, FEBS Lett. 376 (1996) 164-6). In the present study, the reproducibility of these previous findings was confirmed using a new dual-monochrometer exposure system; a 1 Gauss, 60 Hz magnetic field enhanced the production of fluorescence during the respiratory burst. Dose-response studies employed static DC magnetic fields of up to 20 Gauss. Both static DC fields (2.5 and 20 Gauss) showed enhancement of fluorescence production during the respiratory burst. Pre-treatment of neutrophil cells for 10 min at 37 degrees C with an antioxidant, lipoic acid (1-100 µM), significantly elevates fluorescence production in a dose-response manner. The combination of lipoic acid pre-treatment and DC field (2.5 Gauss) exposure further enhanced fluorescence.

Journal Article↗
PubMed2000

Glomeruloid hemangioma in POEMS syndrome shows two different immunophenotypic endothelial cells.

The case of a Japanese woman with glomeruloid hemangioma, an initial marker for POEMS syndrome, is reported. Her cutaneous lesions were multiple and consisted of glomeruloid hemangiomas, cherry-type capillary hemangiomas, and a mixture of both. The specimens of glomeruloid hemangiomas were studied by paraffin section immunohistochemistry with a large panel of antibodies and electron microscopy, respectively. The lesions, whose size ranged from minute foci to large nodules, were composed of anastomosing vascular channels resembling renal glomeruli and had irregular lumina, often featuring capillaries and sinusoid-like spaces. The vascular channels were lined by a single layer of endothelial cells, which showed two types of cells. The capillary-type endothelium possessed large vesicular nuclei with open chromatin and large amount of cytoplasm. The sinusoidal endothelium possessed small basal nuclei with dense chromatin as well as scant amount of cytoplasm. The former cells had a characteristic CD31+/CD34+/UEA I+/CD68- phenotype. Some of these cells ultrastructurally showed intracytoplasmic lumen formation. The latter cells had a characteristic CD31+/CD34-/UEA I-/CD68+ phenotype. The present study shows that glomeruloid hemangioma has unique morphologic and immunologic features that differ from the traditional hemangiomas as well as littoral cell angioma of the spleen.

Antigens, CD↗
PubMed2000

Apocrine acrosyringeal keratosis in association with syringocystoadenoma papilliferum.

We report the clinical and histopathological features of a keratosis that developed in association with syringocystadenoma papilliferum. This tumour shows a pinkish, pedunculated, spherical nodule with a cerebriform surface and visible keratinous plugs. In addition to the typical features of syringocystadenoma papilliferum, the tumour shows many hyperkeratotic columns surrounded by acanthotic epidermis with the characteristics of trichilemmal keratinization and keratohyalin granules. This keratosis seems to be derived from the middle to lower portion of the apocrine acrosyringium, based on the distribution of keratohyalin granules and the direct connection with the apocrine acrosyringium in an early lesion. Accordingly, we propose to identify this rare keratosis as apocrine acrosyringeal keratosis.

Acrospiroma↗
PubMed2000

Two nap sleep test: an easy objective sleepiness test.

The two nap sleep test (TNST) was developed and its usefulness for detecting sleepiness in long-distance drivers has been reported. This study's authors attempted to apply the TNST as a clinical test of sleepiness. A normal control group (n = 29), an obstructive sleep apnea syndrome (OSAS) group (n = 9), and another sleep disorder group (n = 6) participated. As a result of polysomnography, the sleep latency and sleep time did not differ among the groups. In contrast, the frequency of micro-arousal and movement arousal was significantly higher in the OSAS group than in the other groups. The TNST is thought to be useful for evaluating disturbance of sleep maintenance.

Adult↗
PubMed2000

An acoustically evoked short latency negative response in profound hearing loss patients.

In our auditory brainstem response (ABR) tests, a peculiar V-shaped negative wave at around 3 4 ms latency was observed. At present, this acoustically evoked short latency negative response (ASNR) is poorly understood. In order to study its appearance and origin, the ABR data of 3104 tests during 1980-98 were reviewed. The ASNR was found only in profound hearing loss ears under intense stimuli (80-120 dB nHL). Out of the total 653 profound hearing loss patients (981 ears), the click-evoked ASNRs were present in 80 patients (12.3%), 117 ears (11.9%). The age range was from 8 months to 70 years. Demographic outcome revealed significant higher appearance rates in young subjects especially in the 20-30 years group. The ASNR was excluded from an artifact by its reproducibility over time, equipment and institutes. Moreover, it became absent after external auditory canal occlusion, which simply blocked the air conduction without any influence upon scalp potentials or equipment. It had neural response characteristics that the latency and amplitude shortened and increased respectively in response to the increase of stimulus intensity. Because the peculiar V-shaped waveform obviously differs from ABR, the ASNR was not interpreted as a potential generated from the conventional auditory pathway. On the other hand, the ASNR individuals were of good vestibular function in sharp contrast with their poor hearing. This suggests the probable relation between the ASNR and the vestibular system. The saccule and vestibular nucleus are hypothesized to be the sense organ and the origin of the response respectively.

Acoustic Stimulation↗
PubMed2000

Role of catecholaminergic and cyclic AMP systems in psychological dependence on phencyclidine: a study in mutant mice.

Catecholaminergic and/or cyclic AMP (cAMP) systems have been demonstrated to be involved in the development of drug dependence. We investigated the involvement of both systems in psychological dependence on phencyclidine (PCP) by using tyrosine hydroxylase (TH) heterozygous (TH+/-) and cAMP response element binding protein (CREB) binding protein (CBP) heterozygous (CBP+/-) mice. PCP (8 mg/kg) induced place preference in wild-type mice pretreated with PCP (10 mg/kg once a day for 28 days). In these mice, the level of cAMP in the striatum, but not in the thalamus, was increased one day after the last injection of PCP (10 mg/kg). In TH+/- and CBP+/- mice pretreated with PCP (10 mg/kg per day for 28 days), however, no PCP (8 mg/kg)-induced place preference was observed. The level of cAMP in the striatum was increased in CBP+/- mice, but not TH+/- mice. Furthermore, we have demonstrated that the place preference induced by PCP is attenuated by 6-hydroxydopamine, a dopaminergic neurotoxin, and (+) SCH-23390, a dopamine-D1 receptor antagonist, but not by DSP-4, a noradrenergic neurotoxin, and (-) sulpiride, a dopamine-D2 receptor antagonist. These findings suggest that catecholamines and CBP are involved in the development of psychological dependence on PCP and that changes in dopaminergic and/or cAMP systems induced by repeated PCP treatment play an important role in the addiction to PCP.

Animals↗
PubMed2000

Molecular characterization of a novel yeast cell-wall acid phosphatase cloned from Kluyveromyces marxianus.

A novel Kluyveromyces marxianus gene that encodes an acid phosphatase, Pho610, was cloned in Saccharomyces cerevisiae. The deduced amino acid sequence was distinct from S. cerevisiae phosphatases but similar to some fungal enzymes. A peculiar feature of the sequence is that it has hydrophobic stretches both at the N- and C-termini, which is a characteristic of the precursors of glycosylphosphatidylinositol(GPI)-anchored proteins. When the gene was expressed in S. cerevisiae, the active enzyme was recovered in the periplasmic fraction by glucanase digestion. The Pho610 polypeptide was highly glycosylated and a significant portion was covalently linked to the cell-wall glucan. The enzyme was secreted when the C-terminal region was truncated to remove the GPI signal. Therefore, Pho610 is a novel cell-wall protein having an enzyme activity.

Acid Phosphatase↗
PubMed2000

Defect in cell wall integrity of the yeast saccharomyces cerevisiae caused by a mutation of the GDP-mannose pyrophosphorylase gene VIG9.

The Saccharomyces cerevisiae VIG9 gene encodes GDP-mannose pyrophosphorylase, which synthesizes GDP-mannose from GTP and mannose-1-phosphate. Although the null mutant was lethal, the vig9 mutants so far obtained showed no growth defect but immature protein glycosylation and drug hypersensitivity. During our search for cell-wall mutants, we found a novel temperature-sensitive mutant, JS30, which required an osmotic stabilizer for viability. JS30 excreted cell surface proteins in the medium without any indication of cell lysis. Although conventional genetic analysis using mating was impossible, by detailed characterization of JS30 including an in vitro enzyme assay and nucleotide sequencing, we found the defect of JS30 was due to a mutation in the VIG9 gene. These results indicated a critical role of GDP-mannose in maintenance of cell-wall integrity.

Cell Wall↗