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Biomedical subjects

S Okada

Publications and source records attributed to S Okada.

At least 1,099 records · Page 61Linked to original sources
PubMed1988

Purification and Characterization of Thermostable Pullulanase from Bacillus stearothermophilus and Molecular Cloning and Expression of the Gene in Bacillus subtilis.

A thermostable pullulanase (alpha-dextrin 6-glucanohydrolase [EC 3.2.1.41]) from a newly isolated Bacillus stearothermophilus strain (TRS128) was purified and characterized. The enzyme hydrolyzed (1-->6)-alpha-d-glucosidic linkages of pullulan to produce maltotriose, and the optimum temperature was 65 degrees C. About 90% of the enzyme activity was retained after treatment at 65 degrees C for 60 min. By using pTB522 as a vector plasmid, the pullulanase gene was cloned and expressed in Bacillus subtilis.

Journal Article↗
PubMed1988

New type of pullulanase from Bacillus stearothermophilus and molecular cloning and expression of the gene in Bacillus subtilis.

A new type of pullulanase which mainly produced panose from pullulan was found in Bacillus stearothermophilus and purified. The enzyme can hydrolyze pullulan efficiently and only hydrolyzes a small amount of starch. When pullulan was used as a substrate, the main product was panose and small amounts of glucose and maltose were simultaneously produced. By using pTB522 as a vector plasmid, the enzyme gene was cloned and expressed in Bacillus subtilis. Since the enzyme from the recombinant plasmid carrier could convert pullulan into not only panose but also glucose and maltose, we concluded that these reactions were due to the single enzyme. The new pullulanase, with a molecular weight of 62,000, was fairly thermostable. The optimum temperature was 60 to 65 degrees C, and about 90% of the enzyme activity was retained even after treatment at 60 degrees C for 60 min. The optimum pH for the enzyme was 6.0.

Bacillus subtilis↗
PubMed1988

Focal and diffuse membranoproliferative glomerulonephritis in children.

Characteristic deposition of C3 has been reported in type I membranoproliferative glomerulonephritis (MPGN). Immunofluorescence microscopy shows diffuse granular deposition of C3 along the majority of capillary loops with lobular pattern. To determine the specificity of this immunofluorescence finding which might aid in distinction between type 1 MPGN, particularly focal MPGN, and the other glomerulopathies, 530 renal biopsies from 437 children were studied retrospectively. Nineteen patients showed diffuse granular deposits of C3 along the capillary walls with lobular distribution. Three patients had lupus nephritis. Nine patients showed the light microscopic changes of diffuse type I MPGN with the characteristic double-walled capillaries. Six patients showed the changes of focal MPGN, and 1 had diffuse mesangial proliferation but without double contours, and they were regarded as examples of a mild or early form of MPGN. A similar deposition of C3 was not seen in the 418 patients with other conditions. We concluded that diffuse granular deposits of C3 along the capillary walls with a lobular distribution appear to be confined to type I MPGN and lupus nephritis and are seen in all patients with diffuse and focal type I MPGN.

Biopsy↗
PubMed1988

Metabolism of cerebroside sulfate and subcellular distribution of its metabolites in cultured skin fibroblasts from controls, metachromatic leukodystrophy, and globoid cell leukodystrophy.

With pulse-chase study of 1-[14C]stearic acid-labeled cerebroside sulfate (14C-CS) and subsequent subcellular fractionation by Percoll gradient, the metabolism of CS and translocation of its metabolites in human skin fibroblasts from controls, metachromatic leukodystrophy (MLD), and globoid cell leukodystrophy (GLD) were studied. In control skin fibroblasts, CS was transported to lysosome and metabolized there to galactosylceramide (GalCer) and ceramide (Cer) within 1 h. During the chase period, radioactivity was increased at plasma membrane plus Golgi as phospholipids and no accumulation of GalCer or Cer was found in lysosome. In MLD fibroblasts, 95% of 14C-CS taken up was unhydrolyzed at 24 h-chase and accumulated at not only lysosome but also plasma membrane. In GLD fibroblasts, GalCer was accumulated throughout the subcellular fractions and more accumulated mainly at plasma membrane plus Golgi with longer pulse. This translocation of lipid from lysosome seems to have considerable function, even in lipidosis, which may result in an imbalance of the sphingolipid pattern on the cell surface and these changes might be one of causes of neuronal dysfunction in sphingolipidosis.

Cell Compartmentation↗
PubMed1988

Biochemical studies on lymphoblastoid cells with inherited N-acetyl-glucosamine 1-phosphotransferase deficiency (I-cell disease).

Lymphoblastoid cells transformed by Epstein-Barr virus from peripheral lymphocytes of normal individuals and I-cell disease (ICD) patients were used for the enzymic study of lysosomal hydrolases and N-acetylglucosamine 1-phosphotransferase. ICD lymphoblastoid cells secreted a larger amount of hydrolases into medium than normal cells, although the intracellular hydrolases were not deficient in ICD cells. The stimulating effect of 10 mM ammonium chloride on secretion of hydrolases was found only with normal cells, and not with ICD cells, indicating that the hydrolase molecule bearing mannose 6-phosphate was secreted. The ICD lymphoblastoid cells retained the enzymologic characteristics of both lysosomal hydrolases and N-acetylglucosamine 1-phosphotransferase seen in ICD fibroblasts, which allows us to study the pathophysiology of ICD in cells other than fibroblasts.

Adsorption↗
PubMed1988

[A case of giant vesical calculus after ileocystostomy].

A 52-year-old female, who had undergone nephrectomy and ileocystostomy for right-renal tuberculosis and contracted bladder 19 years earlier was seen with anemia and metabolic acidosis. Radiographic findings demonstrated that the patient suffered from a giant vesical calculus. Cystolithotomy was performed and the removed calculus weighed 460 g. Of the 66 cases of giant vesical calculus weighing more than 200 g reported in our country only 7 were in females.

Anastomosis, Surgical↗
PubMed1988

[Bilateral asynchronous renal pelvic tumors: a case report].

A 42-year-old male who had undergone the total nephroureterectomy for transitional cell carcinoma (Grade 3) in the left renal pelvis 5 years ago was seen with asymptomatic macroscopic hematuria. An evaluation of the clinical investigations revealed the right renal pelvic tumor. The right nephroureterectomy was performed and histological examination showed transitional cell carcinoma (Grade 2) of the renal pelvis. Postoperatively, the patient has been treated with intermittent maintenance hemodialysis. He is well and has no evidence of recurrence or metastasis 10 months after the surgery. The previous reports of bilateral renal pelvic tumors (28 cases) are reviewed and the incidence, age, interval between the first and second tumors, prognosis and management including postoperative hemodialysis are discussed.

Adult↗
PubMed1988

[Congenital anterior urethral diverticulum: report of a case].

A case of congenital urethral diverticulum is reported. A 6-month-old male was admitted with difficulty to urinate and swelling of the base of penile shaft. Anterior urethral diverticulum was demonstrated by means of retrograde urethrography. A diverticulectomy combined with cystostomy was performed under the general anesthesia. Although the histological findings were insufficient to determine whether the urethral diverticulum was congenital or acquired, the former was strongly suspected judging from his clinical course. He developed urethrocutaneous fistula, one of the most common postoperative complication, on the 7th post-operative day. A complete cure of the fistula was achieved by the conservative treatment. We collected and analyzed 49 cases of congenital anterior urethral diverticulum of male children in Japan.

Diverticulum↗