Biomedical subjects
Publications and source records attributed to S Okada.
We have developed a sensitive method for the assay of alpha-1,4-glucosidase in cultured skin fibroblasts and muscle tissue using pyridylamino-maltooligosaccharides as fluorescent substrates. This method is useful for the diagnosis of Pompe's disease.
The authors describe an 8-year-old boy who presented with progressive oculomotor palsy on the left side. The diagnostic evaluation with computerized transmission tomography (CTT), metrizamide CTT cisternography, and angiography indicated an extra-axial tumor in the left interpeduncular cistern, extending into the suprasellar and prepontine cisterns. A meningioma was demonstrated with attachment only to the interpeduncular portion of the left oculomotor nerve. The patient was treated successfully by complete removal through a pterional approach.
An electron-microscopic study of the glomeruli was made on 154 children with IgA nephropathy and no evidence of systemic disease, in whom immunofluorescence microscopy had shown diffuse mesangial deposition of IgA. Mesangial deposits were observed in all but eight children. Subepithelial deposits were observed in 40 children and were almost always accompanied by both mesangial and subendothelial deposits. Subepithelial deposits were significantly associated with more severe clinical presentations, a worse outcome and more severe light microscopic glomerular changes. These observations support the concept that IgA nephropathy is an immune complex disease.
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Nitrilotriacetate (NTA), an effective metal-chelating agent, has been used as a substitute for polyphosphates in household laundry detergents. Nephrotoxicity and renal tumorigenicity have been reported in experimental animals that received high doses of NTA po for 4 weeks to 2 years. Since NTA exists in water as a variety of NTA-metal complexes, it was important to investigate the biological effects of NTA in a complexed form. In this study, acute and subchronic toxicity of a ferric iron chelate of NTA (Fe-NTA) was investigated in rats. When Fe-NTA was given ip, acute tubular necrosis and renal failure occurred following a single injection of 15 mg iron/kg. Repeated injections of sublethal doses produced degeneration and necrosis of the proximal tubular epithelium and was associated with polyuria, glucosuria, aminoaciduria, and azotemia. After 9 days of treatment, regeneration of the tubular epithelium with atypical cells was observed. Except for a parenchymal iron deposit, no marked changes were observed in other organs. None of these effects were observed in animals given noncomplexed NTA. In conclusion, the toxicity observed following high doses of NTA given po may be the result of an absorbed metal-NTA chelate.
The possibility of age-associated changes in DNA sequence in terms of amplification and rearrangement was examined in mouse spleen, liver and brain using the method of Southern transfer and filter hybridization. The DNA regions studied were at and around nine cloned sequences, most of which are known to move or amplify in certain situations. No detectable age-associated change, however, was observed in all DNA regions studied. These results suggest that widespread DNA sequence rearrangements or amplifications do not occur during the ageing process in mice.
In the patients with mucopolysaccharidosis II (MPS II, Hunter's syndrome), conductive and sensorineural hearing deficits are frequently observed. Two patients with MPS II underwent adenoidectomy and an ear douche, and their conductive hearing loss recovered after the surgery. Pathological examination of the adenoids revealed the infiltration of faintly PAS-positive plasmacytes with perinuclear vacuole and strongly Alcian-blue positive fibrotic area. Biochemical study was performed by chromatoscanning of electropholesis. The amount of glycosaminoglicans (GAG) in the specimens was increased 2.8-fold compared with the normal control. The electropholetic pattern showed an increase of dermatan sulfate (DS), heparan sulfate (HS) and hyaluronic acid (HA) in the adenoids of the patients. The ratio of DS to HS was 1.1-1.2. In the patients of MPS II, the accumulation of GAG occurs in the pharyngeal tonsil and causes conductive hearing impairment. We recommend adenoidectomy for such patients.
Insulin-binding antibody (IBA) was purified by affinity chromatography using porcine monocomponent (MC) insulin as the ligand. The purity of the antibody was compared with that of the antibody extracted using porcine crystalline (Cr) insulin. Comparing the antibody solutions obtained with MC insulin (MC-lig-sol) or Cr insulin (Cr-lig-sol), the content of IBA in Cr-lig-sol was higher than in MC-lig-sol, but the content of proinsulin-binding antibody (PBA) in MC-lig-sol was very small and statistically lower than that in Cr-lig-sol (P less than 0.01). Adding native MC insulin to a competitive radioimmunoassay suppressed the IBA titer obtained with MC insulin more than that obtained with Cr insulin. By adding native proinsulin in a similar assay system, the PBA titer obtained with Cr insulin was suppressed more than that extracted with MC insulin. Scatchard analysis of the 2 solutions showed that the affinity constants of high affinity antibodies were almost identical, but that of low affinity antibody in MC-lig-sol was larger than in Cr-lig-sol. The binding capacity of low affinity antibody in Cr-lig-sol was 15 times as much as that in MC-lig-sol. Using MC insulin, instead of Cr insulin, as the ligand in affinity chromatography increased the purity of recovered IBA. chromatography increased the purity of recovered IBA.
This study was undertaken to elucidate ultrastructural changes in a severe infantile sialidosis. The materials examined in this study consisted of biopsied rectal mucosa and autopsied small intestine, liver and kidney. In the biopsy sample, axons contained a number of pleomorphic electron dense bodies, and numerous membrane-bound vacuoles were found in Schwann's cells, fibroblasts, endothelial cells, lymphocytes and plasma cells. In autopsy samples, neurons in Auerbach's myenteric plexus of the small intestine were filled with a number of membranous cytoplasmic bodies, pleomorphic dense bodies and vesicles containing dense materials. Hepatocytes in the liver, and glomerular and tubular epithelial cells in the kidney were also extended by a number of membrane-bound vacuoles. These ultrastructural changes in severe infantile sialidosis closely resemble those in GM1-gangliosidosis type 1.
Clinical pictures of 21 cases with I-cell disease patients, 12 males and 9 females, were analyzed. Characteristic coarse facial features and shortness of stature were observed in all cases. In general, the motor development was found to be more severely retarded than the mental development of the patients. Rather little involvement of the nervous system seemed to cause somewhat acceptable mental development in some cases, and also cause the absence of epileptic seizures in all cases. Involvement of the cardiovascular system, especially progressive hypertrophic cardiomyopathy, could be highly responsible for frequent sudden death of I-cell disease patients.
A total of 202 nonepileptic patients (120 males and 82 females) who exhibited spike abnormalities at least twice in their EEG examinations were studied. The incidence of spike abnormalities among nonepileptic patients was 8.1% (847/10,473). The majority (90%) were under age 19. Headache, dizziness and vomiting, and abdominal pain were more frequently observed compared with controls. Mild paroxysmal EEG abnormalities such as diffuse irregular slow wave bursts with spike (27%), positive spikes (25%) or small spike (8.4%) were commonly detected. In three patients who developed epileptic seizures during the follow-up period, more specific EEG abnormalities were often exhibited. Other factors like the age at onset before 9, characteristic clinical symptoms or a positive family history of seizures were confirmed to be necessary for the manifestation of clinical seizures.
Of many exogenous causes, difficult birth, neonatal asphyxia, and coiling of the umbilical cord might be identified as risk factors predicting an initial febrile convulsion. Children with febrile convulsions and exogenous causes are likely to have affected family members, and have a risk of recurrence of seizures on 5 occasions or more. Exogenous causes alone barely raise the risk of recurrence of febrile convulsions after 3 years of age or development of afebrile convulsions. The incidence of exogenous causes is highest in children who develop afebrile convulsions after febrile convulsions, and lowest in children who experience only febrile convulsions, although a little higher than in normal controls.
43 cases of orbital pseudotumor have been studied clinicopathologically during the past 20 years. Orbital pseudotumor might be histopathologically divided into three principal types: lymphoid, granulomatous and sclerosing types. Lymphoid and granulomatous types might be transformed into sclerosing type in the end stage, respectively. Lymphoid type showed good response to radiotherapy and poor or temporary response to steroid therapy. Granulomatous type indicated frequently good response to steroid and poor response to radiotherapy. Sclerosing type demonstrated poor response to steroid and radiation therapy. Therefore, orbital pseudotumor must be treated at an early stage.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.