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Biomedical subjects

S Okada

Publications and source records attributed to S Okada.

At least 1,225 records · Page 68Linked to original sources
PubMed1984

The thin glomerular basement membrane in children with haematuria.

To determine the specificity and significance of widespread attenuation of the glomerular basement membrane on electron microscopy, 240 renal biopsies from 218 children were studied retrospectively. Twenty-three patients showed diffuse attenuation and three of them are cases of hereditary nephritis. The other 20 patients are characterized by persistent microscopic haematuria, absence of proteinuria, normal blood pressure and renal function, and minimal glomerular changes. In 10 of these 20 children, microscopic haematuria was also present in the family. We conclude that widespread attenuation of the glomerular basement membrane is a characteristic of benign familial and non-familial haematuria. The thin glomerular basement membrane may be responsible for the haematuria and may result from incomplete glomerular maturation.

Basement Membrane↗
PubMed1984

The effects of sucrose loading on lysosomal hydrolases.

The addition of 88 mM sucrose to the culture medium of human skin fibroblasts from normal subjects caused remarkable increase in the intracellular lysosomal hydrolase activities. The mechanism of this induction by sucrose loading was carefully studied with several fibroblast strains of different inherited lysosomal storage disorders. In single lysosomal hydrolase defect such as GM1-gangliosidosis, mannosidosis and Sandhoff disease, no induction of the deficient hydrolase was found with 88 mM sucrose loading. In contrast, sucrose loading caused normalization of intracellular lysosomal hydrolase activities in I-cell disease fibroblasts and cytoplasmic inclusion materials disappeared. Subsequent investigations reveal that I-cell disease cells are classified into three subgroups by the degree of hydrolase induction by sucrose loading; a high responding, an intermediate responding and a no-response group. The heterogeneity may be based upon different induction by sucrose loading of the enzyme, probably the residual phosphotransferase which is involved in the processing steps of lysosomal enzyme molecules. With the addition of mannose-6-phosphate and 10 mM NH4Cl to cultured skin fibroblasts, it was shown that sucrose loading caused increased synthesis of lysosomal enzyme proteins. The result of the test with 2,4-dinitrophenol suggests that sucrose is indeed pinocytosed by cultured human skin fibroblasts and localized in lysosomes and that this event is the essential factor to trigger the induction of lysosomal hydrolases. Simultaneous loading of both invertase and sucrose in cultured cells caused no induction of alpha-mannosidase activity. This result indicates that invertase is also pinocytosed, reaches the lysosomes and hydrolyzes sucrose in the lysosomes. Lysosomal overloading with sucrose resulted in induction of lysosomal hydrolases and invertase blocked the induction of alpha-mannosidase activity. However, some induction still exists in beta-galactosidase and alpha-fucosidase activity. Thus it is very likely that the induction of lysosomal hydrolases demands a complicated process. In this article, we investigated the effects of sucrose on the lysosomal hydrolases in cultured human skin fibroblasts of several inherited lysosomal storage disorders and normal subjects and discuss the possible mechanism of the induction of lysosomal hydrolase activities by sucrose loading.

2,4-Dinitrophenol↗
PubMed1984

Muscle fiber type differentiation and satellite cell populations in normally grown and neonatally denervated muscles in the rat.

To examine the neural influence upon fiber type differentiation in developing muscles, newborn rats were subjected to sciatic nerve dissection, and the denervated extensor digitorum longus (EDL) (white) and soleus (red) muscles were examined in chronologic sequence by means of histochemistry and electron microscopy. The skeletal muscles in the newborn rats were undifferentiated (type 2C fibers seen on ATPase staining) and contained numerous myotubes. In the controls, the type 2C fibers started to differentiate at around 5 days and had almost completed type differentiation by 30 days in EDL and by 90 days in soleus muscles. On the other hand, none of the fibers in the neonatally denervated muscles developed into well differentiated type 1 and 2 A fibers, but both the EDL and soleus showed long-lasting type 2C and 2B populations. The satellite cells in the denervated EDL and soleus muscles decreased in number at the same rate as in the control muscles with maturation. The absence of a neural supply in the developing muscles induced a delay in muscle fiber type differentiation but did not influence the satellite cell populations in either EDL or soleus muscles.

Animals↗
PubMed1984

Enhancement of nucleolar RNA synthesis by chromium (III) in regenerating rat liver.

Rats pretreated with CrCl3 at an intraperitoneal dose of 5 mg Cr/kg body weight, and then subjected to partial hepatectomy concentrated Cr in the regenerating liver cells, especially in the nucleoli. Hepatic RNA synthesis induced by partial hepatectomy was further enhanced by Cr(III) administration without changes of the nucleotide pool size at least for 12 hr after the hepatectomy. Of the RNA species newly synthesized, the synthesis of nucleolar RNA was predominantly enhanced. The nucleolar RNA thus synthesized in the regenerating liver of Cr(III)-dosed rats followed normal processing into rRNA as estimated by actinomycin D-chase experiments followed by sucrose density gradient centrifugation analysis and also by nucleotide composition analysis of nucleolar and ribosomal RNAs. These results suggest that Cr accumulated in nucleoli may participate in nucleolar gene expression.

Animals↗
PubMed1984

Unique increase of superoxide dismutase level in brains of long living mammals.

A possible involvement of superoxide dismutase (SOD) level in determination of mammal's lifespan was examined by comparing six different enzyme levels including SOD in brains of eleven mammalian species of different lifespans. When the specific activities of the enzymes were plotted against lifespans on a linear scale, no or weak negative correlations were observed for all enzymes studied except SOD, which revealed positive correlation. The uniqueness of the SOD level suggests that it is one of the enzymes which evolved together with lifespans. It would contribute to long lifespan through protection against oxygen toxicity.

Animals↗
PubMed1984

Seasonal variation of febrile convulsion in Japan.

The 6-year incidence rates of febrile convulsions in all 3-year-old children in Fuchu (covering 95% of children, number examined 17,044) was 8.2%. The incidence was higher in boys than in girls (9.0%: 7.5%, P less than 0.001). The incidence rates varied with the month and year of birth, but the variations observed were slight. Two peak appearances of seasonal variation of the first febrile convulsion were found in November-January and in June-August. The former could be interpreted as a tendency to winter virus infection of the upper respiratory tract in children. The other peak in summer could be explained as a tendency to gastrointestinal infection. Liability to febrile convulsion was influenced by the age of children and by the seasonal variations of febrile illness, but not by the season of birth.

Age Factors↗
PubMed1984

Simulated Reye's syndrome and salicylate therapy.

A 4-year-old girl with juvenile rheumatoid arthritis developed fever, protracted vomiting, disturbance of consciousness and decorticate posture following the administration of salicylate. There were elevated levels of transaminases in serum, hyperammonemia and a fatty liver. However, the fatty droplets were different electronmicroscopically from that of Reye's syndrome. This observation emphasizes the importance of electronmicroscopic observation of the liver in the differential diagnosis between Reye's syndrome and aspirin-induced encephalopathy, because the clinico-pathological findings of intoxication are so similar.

Arthritis, Juvenile↗
PubMed1984

Screening of sugars inhibitory against sucrose-dependent synthesis and adherence of insoluble glucan and acid production by Streptococcus mutans.

Various sucrose derivatives and a sucrose analogue were enzymatically synthesized on the assumption that structural similarities of the sugars to sucrose would endow them with an ability to inhibit the cariogenicity of sucrose. The effect of these sugars on sucrose-dependent synthesis and adherence of insoluble glucan and on acid fermentation of sucrose by Streptococcus mutans was examined in vitro. Although none of them inhibited the acid fermentation, several sugars not only inhibited the synthesis and adherence of insoluble glucan, but were themselves only slightly fermented as well.

Acids↗
PubMed1984

[Bilateral primary germ cell tumors of the testis: report of two cases and review of the literature].

Bilateral germ cell tumors of the testis are not common. The contralateral tumor may develop simultaneously or sequentially. In both cases, bilateral involvement is postulated to represent two primary tumors. Case 1: A 47-year-old male was seen with a painless nodular mass in the right testis. Physical examination revealed hard swelling of both testes besides a nodule in the right testis. He underwent bilateral radical orchiectomy; and, microscopical both tumors proved to be seminoma. Although bipedal lymphangiography was negative for nodal metastases, postoperative irradiation to the pelvic and para-aortic lymph nodes was given to a total dose of 5,800 rad. The patient was alive 15 years after treatment for bilateral testicular tumors. Case 2: A 53-year-old male presented with painless left scrotal swelling. Physical examination showed not only an enlarged hard testis in the left scrotum but also a palpable hard mass in the right testis. Bilateral radical orchiectomy was performed and pathological examination revealed pure seminoma in both testes; a 1 cm mass in the right testis and almost completely replaced tumor in the left testis. Evaluation including retroperitoneal lymph node dissection revealed no metastatic disease. Postoperatively, the patient received 1,900 rad of irradiation to the retroperitoneal space. He is well one year after surgery and has no evidence of recurrence or metastasis. Previous reports of bilateral germ cell testicular tumors are reviewed and the incidence, age, predisposing factors, interval between the first and second tumors, histology, pathogenesis, prognosis, and management are discussed.

Age Factors↗
PubMed1984

A live varicella vaccine in a pediatric community.

A total of 663 children with various underlying diseases were immunized with a live varicella vaccine at the vaccine clinic of Osaka University Hospital during a period of seven years from October, 1975. Clinical reactions after vaccination occurred in 32.4% (24/74) of the children with malignancies and in 0.3% (2/591) of those in other groups. Vaccine-induced immunity was detected for more than 6 years, by FAMA (fluorescent antibody to membrane antigen) and IAHA (immune adherence hemagglutination) tests, and a skin-test for varicella-zoster virus (VZV). During an observation period of more than 7 years, clinical varicella developed in 12 children, 8 of whom were in the group with malignancies. Zoster occurred in only 4 (9.1%) of 44 vaccinees with acute leukemia, this incidence being significantly less (p less than 0.05) than that (21.6%, 8/37) in un-vaccinated leukemic children.

Antibodies, Viral↗
PubMed1984

Two types of lethal damage induced by pepleomycin in cultured Chinese hamster V79 cells.

The cytotoxic effect of pepleomycin (PEP), a derivative of bleomycin (BLM), was investigated and compared with that of BLM on cultured Chinese hamster V79 cells. The concentration-response curve of PEP was biphasic, like that of BLM: the D0 values of the first and second slopes for PEP were 32 micrograms/ml and 140 micrograms/ml, while those of BLM were 60 micrograms/ml and 140 micrograms/ml, respectively. The ratios of D0 for BLM to that for PEP were 1.88 for the first slope and 1.0 for the second one, suggesting that PEP is more cytotoxic than BLM on a unit concentration basis. The time-response curve for PEP showed that the surviving fraction dropped immediately, then rose gradually and finally declined slowly. Analysis of these curves together with the results of further experiments suggested the induction of two types of lethal damage by PEP; potentially lethal damage and non-reparable lethal damage. Potentially lethal damage was induced by PEP treatment, developed within a few minutes, was fixed as lethal damage by trypsinization and was repaired fully within 1 hr if trypsinization was not applied. Non-reparable lethal damage was another type of damage induced by PEP and led to cell death without repair. The two types of lethal damage can account for not only the various shapes of survival curves, but also the differences in cytotoxicity of PEP and BLM.

Animals↗