Biomedical subjects

Y Manabe

Publications and source records attributed to Y Manabe.

At least 73 records · Page 4Linked to original sources

PubMed2000

A new erythrocyte fragility test: a simple procedure utilizing stirring.

In this study, a new simple method to measure erythrocyte fragility with stirring of diluted blood (stirring method) was introduced and evaluated with anemic rats given beta-acetylphenylhydrazine (APHZ) or clofibrate. APHZ at a dose of 40 mg/kg caused significant decreases in hemoglobin and hematocrit 24 hr after administration. However, the marked elevation of erythrocyte fragility was already detectable after 6 hr by our stirring method. At a dose of 10 mg/kg APHZ, although no significant changes in the erythrocytic parameters were observed throughout the experimental period (72 hr), the blood stirring method revealed a marked elevation of erythrocyte fragility 6 hr after administration. Similarly with clofibrate, no changes in erythrocytic parameters were noted following 100 mg/kg or 300 mg/kg administration, but the enhanced fragility was evident with the stirring method. Thus, using our approach, the erythrocyte fragility could be detected at an earlier stage and with greater sensitivity than by decreases in erythrocytic parameters. The results suggest that the stirring method will prove to be useful for detecting erythrocyte fragility in safety studies.

Anemia↗

PubMed2000

[A case of neuro-Behçet's disease with HLA B54 and predominant cerebral white matter lesions].

We report a 55-year-old woman with neuro-Behçet's disease with HLA B54 and predominant cerebral white matter lesions. She showed a cryptogenic high fever and cerebral cortical symptoms such as perseveration, limbkinetic apraxia and dementia. CSF study showed an increase of cell count and protein and a decrease of sugar. MRI showed diffuse T2-high signal intensity mainly in the subcortical white matter of left parieto-occipital lobes and basal ganglia. Her clinical signs greatly improved after administration of prednisolone. Her HLA type was not B51 but B54. Though our patient did not completely satisfy clinical criteria for neither neuro-Behçet's disease nor Sweet's syndrome, she showed partial features of both Behçet's disease and Sweet's syndrome.

Behcet Syndrome↗

PubMed2000

[Familial pure akinesia].

We report a 67-year-old man and his family presenting pure akinesia (PA). He developed bradykinesia. A neurological examination showed a lack of facial expression but no tremor or rigidity. His eye movement was full, and he had frozen gait and pulsion symptoms. There was no evidence of dementia. Levodopa therapy was not effective. Magnetic resonance imaging revealed no brainstem and cerebellar atrophy. 99mTc-ECD-SPECT had no further abnormality. His father and brother had similar symptoms as him. We conclude that this family is the first reported example of pure akinesia with autosomal dominant inheritance.

Aged↗

PubMed1999

Motor neglect following left thalamic hemorrhage: a case report.

We present a report on a patient who developed unilateral motor neglect of the right hemibody after a left thalamic hemorrhage. He presented with pure motor neglect without aphasia, ideomotor apraxia, or unilateral spatial neglect due to a lesion in the centromedian parafascicular (CMPF) and ventrolateral (VL) nuclei of the left thalamus. Although unilateral motor neglect is usually associated with right hemispheric lesions, a left thalamic lesion may also result in isolated motor neglect.

Adult↗

PubMed1999

Transforming growth factor-beta activated during exercise in brain depresses spontaneous motor activity of animals. Relevance To central fatigue.

Intracerebroventricular administration into sedentary mice of the high molecular mass fraction of cerebrospinal fluid (CSF) from exercise-exhausted rats produced a decrease in spontaneous motor activity [K. Inoue, H. Yamazaki, Y. Manabe, C. Fukuda, T. Fushiki, Release of a substance that suppresses spontaneous motor activity in the brain by physical exercise, Physiol. Behav. 64 (1998) 185-190]. CSF from sedentary rats had no such effect. This suggests the presence of a substance regulating the urge for motion as a response to fatigue. A bioassay system using hydra, a freshwater coelenterate, showed an activity indistinguishable from transforming growth factor-beta (TGF-beta) in the CSF from exercise-fatigued rats, while not in that from sedentary rats. The increase in the concentration of active TGF-beta in the CSF from exercise-fatigued rat was also ascertained by another bioassay system using mink lung epithelial cells (Mv1Lu). Injection of TGF-beta into the brains of sedentary mice elicited a similar decrease in spontaneous motor activity in a dose-dependent manner. Increasing the exercise load on rats raised both the levels of active TGF-beta and the activity of depression on spontaneous motor activity of mice in the CSF of rats. Taken together, these results suggest that exercise increases active TGF-beta in the brain and it creates the feeling of fatigue and thus suppresses spontaneous motor activity.

Animals↗

PubMed1999

Differential regulation of AP-1 DNA-binding activity by D1 and D2 dopamine receptor antagonists in the rat caudate-putamen and globus pallidus following a unilateral 6-OHDA lesion of the medial forebrain bundle.

The effect of D1 and D2 dopamine receptor antagonists on the DNA-binding activity of the AP-1 transcription factor was studied in the rat caudate-putamen and globus pallidus following a unilateral 6-OHDA lesion of the medial forebrain bundle. In the caudate-putamen, vehicle-treated rats showed increased AP-1 DNA-binding activity, which appeared to be reversed completely by treatment with the D1 receptor antagonist SCH23390 (1 mg kg-1 i.p.) and partially by the D2 antagonist sulpiride (50 mg kg-1 i.p.). In the globus pallidus, vehicle and sulpiride did not induce AP-1, while SCH23390 increased it significantly. This induction was much more prominent in the 6-OHDA-lesioned hemisphere than in the intact hemisphere. The present study suggests that in the caudate-putamen, dopamine-depletion induces long-lasting enhancement of AP-1 DNA-binding activity via activation of D1 receptors and the simultaneous activation of D2 receptors facilitate it. However, in the globus pallidus of the 6-OHDA-lesioned hemisphere, D1 but not D2 antagonism induces AP-1 in certain cell populations which may be distinct from those expressing AP-1 upon stimulation of D2 receptors.

Animals↗

PubMed1999

Enhanced Fos expression in rat lumbar spinal cord cultured with cerebrospinal fluid from patients with amyotrophic lateral sclerosis.

The etiology of amyotrophic lateral sclerosis (ALS) remains unknown although an existence of neurotoxic substances in cerebrospinal fluid (CSF) from ALS patients have been postulated. In order to investigate a possible effect of CSF from ALS patients on cellular signaling in spinal neurons, we compared Fos-like immunoreactivity (Fos-LI) in organotypic cultures of rat lumbar spinal cord after addition of CSF from ALS patients or another neurologic disease. Fos-LI was normally present predominantly in dorsal horn neurons, whereas only a few ventral horn neurons were positive for Fos-LI. The number of Fos-LI positive neurons significantly increased in dorsal horn with addition of CSF from ALS patients as well as glutamate at 100 microM. However, the increase was not observed with addition of CSF from other neurologic diseases. The increase in Fos-LI positive neurons in dorsal horn was reversed by a further supplement of MK801, an N-methyl-D-aspartate (NMDA) receptor antagonist, but not of CNQX, an alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate antagonist. These results indicate that there may be substances in CSF from ALS patients that stimulate Fos expression in certain populations of spinal neurons via the NMDA receptors.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

PubMed1999

An MR image of spinal cord sarcoidosis.

We present a case of spinal cord sarcoidosis with a unique magnetic resonance imaging (MRI) finding. MRI of the cervical spine revealed an unusual lesion of low signal intensity on T2-weighted image at the core of the lesion surrounded by high signal intensity. T1-weighted gadolinium enhanced image showed a high signal at the core lesion. Low signal intensity on T2-weighted image in the case was suggested to be due to hemosiderin deposition. Steroid therapy dramatically improved clinical symptoms with a marked reduction of peripheral T2 high intensity area and the core lesion size detected by gadolinium enhancement.

Aged↗

PubMed1999

Synthesis and antimicrobial characteristics of novel biocides, 4,4'-(1,6-hexamethylenedioxydicarbonyl)bis(1-alkylpyridinium++ + iodide)s.

Potent new biocides against both bacteria and fungi, 4,4'-(1,6-hexamethylenedioxydicarbonyl)bis(1-alkylpyridinium iodide)s (4DOCBP-6,n) (alkyl chain length, n = 8, 10, 12, 14, 16 and 18) were synthesized, 4DOCBP-6,n is a bis-quaternary ammonium compound (bis-QAC) and has a symmetrical dimeric structure which is composed of two alkylpyridinium iodides connected with a hexamethylenedioxydicarbonyl chain. 4DOCBP-6,10 and 4DOCBP-6,12 exhibited wide and effective antimicrobial spectra, compared with those of typical bactericides, N-dodecylpyridinium iodides (P-12) and benzyldimethyldodecylammonium chloride (BAC), or a popularly-used fungicide, 2-(4-thiazolyl)benzimidazole (TBZ). Their superior properties would be due to the unique dimeric structure which contains two active moieties in a molecule.

Anti-Bacterial Agents↗

PubMed1999

[Sporadic ALS].

Explore the source record for details and available documents.

ATP-Binding Cassette Transporters↗

PubMed1998

Release of a substance that suppresses spontaneous motor activity in the brain by physical exercise.

Injection of the cerebrospinal fluid (CSF) collected from rats fatigued by obligatory swimming into the cisterna magna of mice suppressed the spontaneous motor activity of the mice. The suppressive activity was abolished by heat denaturation of the CSF and was found in the CSF fraction with a molecular weight above 10,000 after ultrafiltration. These findings suggest the presence of a substance(s) released in a fatigued animal's brain that suppresses its spontaneous motor activity and generates the sensation of fatigue.

Animals↗

PubMed1998

Bactericidal action of 4,4'-(alpha,omega-polymethylenedithio)bis-(1-alkylpyridinium iodide)s.

Bactericidal action of novel bis-quaternary ammonium compounds (bis-QACs), 4,4'-(alpha,omega-polymethylenedithio)bis(1-alkylpyridinium iodide)s (4DTBP-m,n) was studied. The bactericidal activity of 4DTBP-m,n in water was not affected by the molecular hydrophobicity unlike general mono-QAC, N-dodecylpyridinium iodide (P-12), while the bacteriostatic activity in the medium was reduced with their hydrophobicity. This result suggested that the hydrophobic materials in the medium interact with 4DTBP-m,n and cover their active moiety. Since the bactericidal activity using the measurement system supplemented with peptone was influenced by the molecular hydrophobicity, this speculation was supported. The plots of the bacteriostatic activities of 4DTBP-m,n against the surface hydrophobicities of various bacteria accord to the straight line as in the case of P-12. The slope of the line of 4DTBP-6,12 was comparatively smaller than that of 4DTBP-6,8, indicating that the compounds having longer alkyl group tend to reduce their activities against the bacteria with hydrophobic cell surface because of their interaction with the hydrophobic materials. The novel bis-QACs have an ability to liberate rapidly and abundantly the turbid materials from cells, that is, a bacterioclastic activity. The bacterioclastic activity of P-n was influenced by the length of alkyl group, while 4DTBP-6,n had almost the same activity regardless of its length. Observation by scanning electron microscope (SEM) revealed that 4DTBP-6,8 fatally damaged Escherichia coli cells, and that the morphological alteration of the cells caused by the bis-QAC was greatly different from that of the usual QAC. Therefore, the effective bacterioclastic action, and excellent bactericidal action is due to the unique dimeric structure of 4DTBP-m,n.

Anti-Bacterial Agents↗

PubMed1998

[Effects of lidocaine on salicylate-induced discharge of auditory neurons in the inferior colliculus of the guinea pig].

The effects of lidocaine (a local anesthetic known to relieve tinnitus) in a guinea pig animal model of tinnitus in which spontaneous discharge of inferior colliculus (IC) neurons was augmented by intravenous application of salicylate (200 mg/kg) were studied by extracellular recording. The salicylate induced discharge was inhibited by intravenous injection of lidocaine at a concentration (lmg/kg) used clinically for treating tinnitus. IC neurons could be divided into two groups according to the difference in sensitivity to lidocaine, weakly sensitive neurons and highly sensitive neurons. In weakly sensitive neurons, the lidocaine effect lasted for less than five min, and the inhibiton of the discharge of neurons was increased as the latency of response to the sound stimulus became longer. It was considered that lidocaine inhibited the propagation of action potentials by blocking Na+ channels. In highly sensitive neurons, on the other hand, the activity of neurons was almost completely inhibited for longer than 30 min and it might involved different mechanisms. Furthermore, the inhibitory action of lidocaine was stronger in IC neurons discharging at higher frequencies, suggesting a use dependent blocking action of Na+ channels, by lidocaine.

Action Potentials↗

PubMed1998

Presumed venous infarction in spinal decompression sickness.

We describe the serial MR imaging findings in a patient with spinal decompression sickness. In the acute phase, the spinal cord was swollen, with increased T2 signal in the posterior part of the column; 1 month later, marked contrast enhancement was noted in the same location; and 2 months later, the swelling and T2 signal had decreased. MR imaging may facilitate the early diagnosis of spinal decompression sickness.

Decompression Sickness↗

PubMed1997

Phosphorylation of the C2 subunit of the proteasome in rice (Oryza sativa L.).

Proteasomes function mainly in the ATP-dependent degradation of proteins that have been conjugated with ubiquitin. To demonstrate the phosphorylation of proteasomes in plants, we conducted an enzymatic dephosphorylation experiment with a crude extract of rice cultured cells. The results indicated that the C2 subunit of the 20S proteasome is phosphorylated in vivo in cultured cells. An in-gel kinase assay and analysis of phospho-amino acids revealed that the C2 subunit is phosphorylated by a 40-kDa serine/threonine protein kinase, the activity of which is inhibited by heparin, a specific inhibitor of casein kinase II. The catalytic subunit of casein kinase II from Arabidopsis was also able to phosphorylate the C2 subunit. These results suggest that the C2 subunit in rice is probably phosphorylated by casein kinase II. Our demonstration of the phosphorylation of proteasomes in plants suggests that phosphorylation might be involved in the general regulation of the functions of proteasomes.

Arabidopsis↗

PubMed1997

The effect of sodium thiosulfate on ototoxicity and pharmacokinetics after cisplatin treatment in guinea pigs.

The effect of sodium thiosulfate (STS) on the pharmacokinetics and ototoxicity of cisplatin (CDDP) was investigated in guinea pigs. Animals received three intramuscular injections of 7.5 mg/kg CDDP separated by intervals of 5 days with or without STS (1,000 mg/kg) administered intraperitoneally immediately and 1 h after each injection of CDDP or 3 and 6 h later. When administered alone, CDDP caused total outer hair cell (OHC) loss in the basal and second turns of the cochlea. In the group administered CDDP and STS, damage to the OHCs was mild when STS was given concurrently, but was severe when STS was given 3 and 6 h later. Pharmacokinetics measured as free and total platinum (Pt) concentrations in plasma and total Pt concentration in perilymph was not affected after administration of STS with CDDP. These results suggest that an inactive Pt-thiosulfate complex is formed in plasma and is measured as a free Pt component which enters the perilymph via the blood-cochlear barrier. Two possible mechanisms are proposed by which STS reduces ototoxicity: entry of CDDP into target cells such as OHCs and strial marginal cells or binding to intracellular macromolecules of these cells is prevented.

Animals↗

PubMed1997

Molecular and biochemical characterization of a proteasome subunit from rice and carrot cells.

Proteasomes function mainly in the ATP-dependent degradation of proteins that have been conjugated with ubiquitin. We isolated a cDNA clone for a rice protein that exhibited high homology to subunit C2 of proteasomes. Southern blot analysis revealed that the corresponding gene was present as a single copy in the rice genome. After fractionation of a crude extract from cultured cells, a 35-kDa protein that cross-reacted with antibodies against the C2 subunit was recovered in the peak fraction of both 20 S and 26 S complexes. The same antibodies cross-reacted with two proteins in seedlings, one of which was the same as that detected in cultured cells. The level of the protein was reduced in roots under conditions of high salinity. The 35-kDa protein was not detected in the nuclei of rice of carrot cells. However, during somatic embryogenesis of carrot cells, the C2 subunit was found in the nucleus at the globular stage, and it gradually disappeared in the period from the heart to the torpedo stage. Cells at the globular stage are proliferating rapidly, thus, it is possible that proteasomes are associated with the proliferation of plant cells.

Amino Acid Sequence↗

PubMed1997

Non-metric tooth crown traits of the Thai, Aka and Yao tribes of northern Thailand.

A survey was made of Thai tribe members, who cultivate rice paddies in the flatlands of northern Thailand, and of the Aka and Yao tribes, who farm with the slash-and-burn method in a mountainous region of northern Thailand. Plaster casts of the upper and lower jaws of tribe members were taken. Seventeen non-metric traits of their tooth crowns were classified and compared with other Mongoloid populations in various regions and periods. It was observed that the Thai tribe had the Sundadont characteristics, typical of South-East Asians, but the Aka and Yao tribe had more Sinodont than Sundadont characteristics, typical of North-East Asians. The regional and temporal variations of crown morphology in South-East Asia suggest earlier setting of the Thai tribe than the Aka and Yao tribes in this region. Moreover, comparison of the tooth morphological and linguistic classifications contradicts the traditional theory of the genealogy of the Thai language family. On the subject of the origin of modern South-East Asians, it is suggested that there has not been a gene flow of Sinodonty into Sundadonty of the principal ethnic groups in Neolithic South-East Asia.

Asian People↗