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M Ayabe

Publications and source records attributed to M Ayabe.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Non-herpetic acute limbic encephalitis].

We reported four cases of acute encephalitis, in which MRI abnormalities localized in the limbic system. In the four cases, fever and consciousness disturbance were commonly found and convulsive seizures appeared in three. Within 10 days, their consciousness level became clear, but severe amnestic syndrome remained as sequela. Cerebrospinal fluid (CSF) at the acute stage revealed mild lymphocytic pleocytosis and elevated protein. MRI revealed abnormal signal intensities in both hippocampi and amygdaloid bodies, although CT scans were normal. Herpes simplex encephalitis selectively affects one or both temporal lobes and the limbic system, But our cases spared the temporal lobes. Additionally, serum and CSF antibody titers by CF and ELISA for herpes simplex virus (HSV) were within normal range from the acute to convalescent stages. Neither HSV type 1 and 2 DNA genomes by sensitive PCR-hybridization method were detected in CSF taken from the acute stage of all four cases. On the other hand, paraneoplastic limbic encephalitis is known as a subacute encephalitis predominantly involving the limbic system. MRI shows high signal intensities on T2-weighted in both medial temporal lobes. In our cases, this type of limbic encephalitis was excluded because of the acute onset and lack of malignancy. Accordingly, our four cases are regarded as non-herpetic acute limbic encephalitis. Several Japanese similar cases have been reported. Further etiological studies should be performed.

Acute Disease↗
PubMed1994

[Binswanger's type encephalopathy without alopecia and lumbago in young hypotensive patients].

Binswanger's type encephalopathy is characterized by progressive dementia and diffuse subcortical ischemic lesions associated with arteriosclerosis. Hypertension is believed to be a major pathogenic factor in causing this encephalopathy but there are some cases of the encephalopathy not suffering from hypertension. In 1985, Yamamura et al. and Fukutake et al. reported familial cases of normotensive juvenile Binswanger's type encephalopathy with alopecia and lumbago, and considered it to be possibly a new clinical syndrome. We reported three cases of relatively young-onset (under the age of 40) Binswanger's type encephalopathy with persistent hypotension. All three patients suffered from neither alopecia nor lumbago. Patient (male aged 40) had repeated episodes of ischemic stroke and had progressive dementia. Patients 2 (male aged 41) and 3 (male aged 34) were not in a state of dementia, but had a history of transient ischemic attacks, and at present are completely symptom-free. Though there were no risk factors for cerebrovascular disease in these cases, the repeated episodes of ischemic stroke and the existence of small multiple lacunes in the basal ganglia on CT and MRI suggest that the white matter damage was principally due to a vascular disorder. In these cases, persistent hypotension was characteristic and might be a factor for the induction and exacerbation of this encephalopathy. These three cases are different from the classic form of Binswanger's type encephalopathy based on hypertension. Normotensive cases have been described before, but our cases do not seem to fall into this category because the blood pressure constantly remained hypotensive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Hepatitis B virus antibody positive spastic paraparesis].

We present here thirteen patients (5 men and 8 women, aged 31 to 73, mean 55 years) with spastic paraparesis who showed clinical features similar to those of HTLV-1 associated myelopathy without HTLV-1 antibody, but with positive antibody to hepatitis B virus (HBV). All of these patients showed slowly progressive difficulty in walking. Five patients had previous histories of blood transfusion, of these one with history of B hepatitis. Neurologically, muscle weakness, spasticity and exaggerated deep tendon reflexes in the lower extremities were common to all the patients. Seven patients showed Babinski's reflex. Disturbance of micturition was noted in 3 patients. None showed organic changes of the spine on magnetic resonance image (MRI). None was serologically positive for syphilis and had cryoglobulin and hypergammaglobulinemia. Elevated levels of the liver enzymes were noted in two patients. All patients were positive for hepatitis B surface antibody (HBs-Ab) (EIA) but negative for hepatitis B surface antigen (HBs-Ag) (EIA). Five patients were seropositive for hepatitis C virus (HCV) (PHA). In 3 of them, reverse transcriptase polymerase chain reaction was performed but failed to detect HCV-RNA. All patients underwent spinal tap, and showed normal cell count and protein concentration in their cerebrospinal fluid (CSF). Atypical cells were not observed in all the patients. The CSFs from three patients were tested for HBs-Ag and HBs-Ab. HBs-Ag was negative in all three patients, but HBs-Ab was positive in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Comparison between natural and immunized anti-GM1 antibodies analyzed by marker releasing rate assay with liposome.

Naturally occurring rabbit anti-GM1 was compared with immunized induced anti-GM1 antibody in the same individual rabbits by the characterization of immune potency determined by complement-dependent damage to liposomes containing GM1 as antigen. Antigen-antibody reaction was the rate determining step in this assay. The maximum rate was measured by the first derivative conversion monitoring in spectrophotometry and the maximum level of marker released was measured by the conventional method described previously. When the concentration of sera required to get fifty percent of maximum values in each assay were compared, the ratios (rate assay/conventional assay) were 5.7 to 10.0 in natural antibodies and 3.2 to 2.3 in immunized induced antibodies, respectively. Furthermore, the maximum rate of marker release from liposome was not correlated with the maximum level of marker released depended on the sources of antibodies. These results suggest that natural antibody, even the titer was high in conventional liposome assay, has different characteristics compared with the immunized induced antibody.

Animals↗
PubMed1989

Diagnostic value of ganglioside patterns in plasma of human diseases.

A method that could be facilitated for the quantitation and qualitation of gangliosides in human plasma was developed and applied in the present study for characterization of ganglioside patterns in plasmas of patients with neoplastic diseases including gastric cancer, adult T-cell leukemia (ATL), and acute lymphocytic leukemia (ALL). As a retrovirus-infected disease with different clinical entity, human T-cell lymphotropic virus type I-associated myelopathy (HAM) was also subjected to this study. The results were compared with the patterns obtained from normal control plasmas. The analytical data revealed that GM3 increased in gastric cancer, GT1b decreased in HAM and ATL, and GD3, GM1 and GM3 decreased in ALL. There were close correlations between various human diseases and the presence of gangliosides with their specific patterns. Furthermore, gangliosides purified from plasma of patients with HAM significantly inhibited the expression of CD4 antigen on human T lymphocyte membrane. Therefore, analytical studies of plasma gangliosides could provide diagnostic and therapeutic values in retroviral infections.

Adult↗
PubMed1980

Determination of seven noble metals in standard rock samples by means of thermal neutron activation analysis.

Ruthenium, silver, rhenium, osmium, iridium, platinum and gold in standard rock samples from Geological Survey of Japan (JB-1, JB-2, JG-1 and JA-1) were determined by thermal neutron activation method with a systematic chemical separation. U.S. Geological Survey standard rocks (BCR-1 and G-2) were also analyzed to obtain an information about the accuracy and precision on the method. Generally agreement of our results with previous values for BCR-1 and G-2 was excellent. The noble metal contents in the igneous rocks from Japanese region were approximately comparable to those in the corresponding rocks from the continental region, and showed a tendency to decrease with increasing silica contents, with weak interrelations to other major elements.

Japan↗
PubMed1980

A systematic chemical separation for thermal neutron activation analysis of seven noble metals in rock.

A method for the systematic activation analysis of seven noble metals--ruthenium, silver, rhenium, osmium, iridium, platinum and gold--in rocks were developed and examined with radiotracers and irradiated rock samples. After the fusion of the irradiated rock sample with sodium hydroxide and sodium peroxide, 10% sodium sulfide solution is added and rhenium is extracted with pyridine-benzene mixture from 6N sodium hydroxide solution. From the hydroxide-sulfide precipitate fraction, ruthenium and osmium are distilled as tetroxides, silver is precipitated as chloride, gold is extracted with ethyl acetate, and iridium and platinum are extracted with diantipyrylmethane. Each fraction is purified and subjected to the gamma-ray spectrometry. Chemical yields for the elements are more than 60%. Determination limits are given for the seven elements.

Activation Analysis↗
PubMed1978

Determination of zirconium in natural water by spectrophotometry following the concentration step with yield tracer.

Zirconium in natural water samples was determined spectrophotometrically after concentration using95Zr as a yield tracer. Acidified sample (1l) with a known amount of 95Zr was evaporated to dryness, treated with hydrofluoric and nitric acids, and then with nitric and perchloric acids, and evaporated nearly to dryness. The residue was taken up with 2 M perchloric acid and zirconium in the solution was extracted with 0.1 M thenoyltrifluoroacetone (TTA) in benzene. The TTA complex solution was converted to hydrochloric acid solution. After the recovery yield was estimated by measuring the radioactivity of 95Zr in the final solution, zirconium was then determined by spectrophotometry with Arsenazo III. Zirconium contents in lake and hot and cold spring samples from Nikko and Shiobara districts were found to be 0.29-2.8 microgram/l by this method.

Fresh Water↗