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Biomedical subjects

T Okayasu

Publications and source records attributed to T Okayasu.

At least 37 records · Page 2Linked to original sources
PubMed1991

[A mild variant case of maple syrup urine disease].

We reported a mild variant case of maple syrup urine disease. He was unable to walk alone at 2 years of age and developed seizures and intermittent ataxia at 5 years of age. Activity of 1-14C-leucine decarboxylase in fibroblasts revealed 40% of normal activity in the boy and 90% in the mother. MRI showed hypo-myelination of white matter and mild atrophy of brain stem and cerebellum. Dietary treatment was not effective for ataxia and brain atrophy.

Atrophy↗
PubMed1990

Maintenance and cure of the L5178Y murine tumor-dormant state by interleukin 2: in vivo and in vitro effects.

We studied the antitumor effects of recombinant human interleukin 2 (HuIL-2) in DBA/2 mice which harbor L5178Y lymphoma cells in a tumor-dormant state in the peritoneal cavity and in peritoneal cell (PC) cultures prepared from such mice. Intraperitoneal injection of 10,000 to 100,000 units of HuIL-2/day for 10 days eliminated tumor cells from 30-45% of the mice, whereas no mice became tumor-free in the phosphate-buffered saline-treated control group. In vitro, as little as 10 units/well HuIL-2 failed to stimulate cytotoxic activity in PC from normal mice. HuIL-2 directly stimulated antitumor cytotoxic activity in nonadherent but not in adherent PC cultures from tumor-dormant mice; however, treatment of whole PC from tumor-dormant mice with HuIL-2 resulted in the development of antitumor cytotoxic activity in the adherent PC population which were derived from such cultures. This suggests that the HuIL-2-treated nonadherent PC contributed to the cytotoxic activation of the adherent PC. Flow cytometric analysis of the PC from tumor-dormant mice revealed a polyclonal expansion of T-lymphocytes. Lyt-1+, Lyt-2+, and L3T4+ lymphocytes were all required for HuIL-2 to induce antitumor cytotoxic activity.

Animals↗
PubMed1990

Immunological regression of metastatic cancer in the liver as a result of "in vivo xenogenization".

We attempted to induce the regression of liver metastatic tumor cells in vivo by the administration to rats of Friend leukemia virus (FV) (in vivo xenogenization). The virus which was used in this experiment, FV, is highly immunogenic and does not normally cause disease in an adult rat. At first, we induced a FV viremia in tumor bearing rats in order to deliver the virus to the site of the tumor cells. FV viremia was induced by injecting 60 mg/kg cyclophosphamide (CY) i.v. after the administration of FV, and by transferring syngeneic bone marrow cells so that FV would be able to infect them and then replicate. In order that the tumor cells which were infected with virus should regress, it was necessary to break down their tolerance to FV antigens. As adoptive immunotherapy we therefore, transferred syngeneic spleen cells from rats which had been immunized with FV to tumor bearing rats. The result of this experiment was that these tumor bearing rats infected with FV which had received either normal syngeneic spleen cells or no spleen cells as controls died from liver metastasis (8 out of 9 rats (89%) and 15 out of 17 (88%) respectively). On the other hand, only 4 out of the 15 (27%) tumor bearing rats which were infected with FV and which received FV-immune spleen cells died from liver metastasis. These sets of data indicate that the in vivo xenogenization of tumor cells are indeed able to induce the regression of metastatic tumor cells.

Animals↗
PubMed1990

A family case of nephrogenic diabetes insipidus.

Two brothers, patient 1 with fever and vomiting, and patient 2 with failure to gain weight were studied. After 4 hr of water deprivation test, the urinary osmolality of the patient 1 was only 105 mOsm/liter and his body weight showed a 4.6% reduction. In response to desamino-8-D arginine vasopressin intranasal administration, no significant elevation of urinary osmolality of patient 1 occurred. After low dose vasopressin tests, the maximal urinary osmolality of their father was in the normal range, but that of their mother was below the normal range. Moreover, the patients showed no significant increase of urinary osmolality after the same tests. The brothers were diagnosed as nephrogenic diabetes insipidus (NDI) and their mother was diagnosed as a carrier. An early diagnosis of NDI is important, since adequate managements such as low-solute diet with restricted protein and salt intake or such as water intake at frequent intervals can prevent the hyperosmolality which would develop the delayed mental and physical developments. The usefulness of the combination of indomethacin with thiazide diuretics is described.

Adult↗
PubMed1990

[MR imaging of internal carotid artery occlusion].

Five patients with internal carotid artery occlusion were studied with MR imaging at 0.22 T. At the carotid siphon, occluded vessels showed absence of flow void in three patients. But two cases had "partial flow void" which mimicked small arterial caliber. In these patients angiography showed collateral circulation to the carotid siphon. So the partial flow void in the carotid siphon suggested internal carotid artery occlusion with collateral circulation.

Aged↗
PubMed1990

[MR imaging of adenomyosis].

MR imaging characteristics of adenomyosis were studied in nine women (five diffuse type, four focal type) who underwent hysterectomy. In all cases, MR images were correlated with surgical/pathologic findings. On T2-weighted images, diffuse type appeared as a thickening of the junctional zone, because it was often isointense with this zone. Focal type appeared as a low signal intensity, round or oval shaped mass poorly marginated from the adjacent myometrium.

Adult↗
PubMed1989

Cytotoxicity of galactose, tyrosine and methionine in cultured suckling rat hepatocytes: relation to liver immaturity.

Monolayers of suckling rat hepatocytes cultured for 24 hours were treated with galactose, I-tyrosine and I-methionine. The purpose was to study the reasons for the clinical improvement of patients with neonatal hepatitis after dietary restriction of these nutrients. Galactose, tyrosine, and methionine was cytotoxic on suckling rat hepatocytes, yet had no effect on adult rat hepatocytes. Furthermore, the pretreatment of suckling rat hepatocytes with dexamethasone ameliorated the cytotoxicity and induced a differentiation of the cells. These results suggested that the cytotoxicity resulted from the immaturity of suckling rat hepatocytes and therefore dietary restriction of galactose, tyrosine and methionine might be a useful treatment for patients with neonatal hepatitis.

Animals↗
PubMed1989

[A case of benign fibrous histiocytoma of the lung in a child].

A case of benign fibrous histiocytoma of the lung in a 8 years old boy was presented. He was first admitted in May, 1983, with recurrent pneumonia. Chest X-ray showed a ill-defined mass in the right lower lobe. Bronchoscopy revealed a round tumor, 1 cm. in maximum diameter, with complete obstruction of the Truncus Intermedius. Endoscopic resection was performed and partial obstruction of the Truncus Intermedius remained. He was re-admitted with pneumonia of the right middle lobe in March, 1986. Bronchoscopy showed severe stenosis of the Truncus Intermedius. Right middle and lower lobectomy was performed. The 4 X 4 X 3 cm tumor was located in the median of the Truncus Intermedius. Microscopically, the lesion composed of fibroblast-like cells and histiocyte-like cells. The patient's post-operative course was uneventful. He has no signs of local recurrence or metastasis. We believe, this is the first reported primary benign fibrous histiocytoma of the lung in a child in Japan.

Bronchial Neoplasms↗
PubMed1989

[MR imaging of gynecological neoplasms using a low-magnetic-field machine].

Magnetic resonance (MR) images were obtained from 171 patients with benign and malignant neoplasms in the uterus and ovary, by using a low magnetic-field machine with 0.22 T, and its usefulness is discussed. Small uterine neoplasms (a few mm of its diameter) can be detected as an abnormal intensity. Therefore, the detectability is helpful for determination of their staging. In addition, some adenomyosis can also detected as distinctive findings, although it is difficult to point out those diseases by other imaging modalities. From MR images of ovarian cystic tumor, the biochemical information of its fluid content can be obtained. However, it is difficult to get distinctive features from MR images of solid neoplasms. Even though the magnetic field is low such as 0.22 T, MR images are useful for diagnosis of gynecological neoplasms because of the high contrast image quality and the capability of providing tomograms with arbitrary planes.

Adult↗
PubMed1989

[A case of mediastinal schwannoma originating from the intrathoracic vagal nerve].

A 46-years-old man was admitted because of an abnormal shadow on X-ray. The operation underwent under the diagnosis of benign tumor in the antero-superior mediastinum. At the operation, the tumor arise from the right intrathoracic vagal nerve and it was resected with the transection of vagal nerve. The histological diagnosis was schwannoma. Postoperative course was uneventful except the slight hoarseness. Intrathoracic vagal tumor is rare and we have found 19 reported cases among Japanese literatures. This case is considered to be the 20th case originated from the intrathoracic vagal nerve in Japan.

Cranial Nerve Neoplasms↗
PubMed1989

[A case of primary pulmonary cryptococcosis].

A 53-year-old male was admitted because of an abnormal chest roentgenogram showing a solitary tumor shadow in the right upper lung field. Laboratory data was normal. Although examination with the bronchoscope and sputum cytology showed no abnormal findings, a partial resection of the right upper lobe was performed. Microscopic examination of the lesion was cryptococcosis. As another focus was not found by systemic examination, the lesion was disclosed primary pulmonary cryptococcosis. Cryptococcosis is rare but we must think of it when we meet a solitary tumor shadow on the chest roentgenogram.

Cryptococcosis↗
PubMed1988

[Inhibitory effect of UFT on postoperative lung metastasis of mammary adenocarcinoma in SHR rats].

It is well known that UFT has significant therapeutic effects against experimental and clinical cancers at the primary sites. In this experiment, we studied the inhibitory effect of UFT on the lung metastasis of spontaneously developed rat mammary carcinoma (SST-2) after surgical excision of the primary site. In comparison of UFT-treated (15 or 30 mg/kg/day) with 5-FU-treated (9.7 or 19.5 mg/kg/day) groups, UFT was more effective than 5-FU in the antitumor activity and the inhibitory effect of lung metastasis with/without surgical excision of the primary sites. Rats (5-10 rats per group) were inoculated s.c. with 1 x 10(6) SST-2 cells and administered with UFT orally (15, 30 or 60 mg/kg/day) starting the day after tumor inoculation for 30 days. The therapeutic effect of UFT was studied by the growth rate of primary tumor and the numbers of metastatic colonies in the lung 35 days after tumor inoculation, comparing the UFT-treated with control groups. UFT administration at the doses of 30 or 60 mg/kg/day markedly inhibited the growth of the primary tumors and the number of metastatic lung colonies decreased, compared with that of the control group. However, in the group of rats treated at the dose of 60 mg/kg/day, 60% of rats died from the side effects of UFT such as weight loss, hemorrhage etc. In all groups in which the primary tumors were surgically excised 20 days after tumor inoculation and then treated with UFT (15, 20 or 30 mg/kg/day), we observed marked prolongation of survival period and inhibition of lung metastasis as well. Furthermore, we studied the effect of combination therapy of UFT and lentinan (1 mg/kg/day i.p.) on the metastasis of SST-2 cells after surgical excision of the primary sites. It was more effective than UFT alone. Thus, it is clear that UFT is an effective anticancer drug to inhibit metastasis of tumors in the lung after surgical excision of primary tumor.

Adenocarcinoma↗
PubMed1988

[Functions of large granular lymphocytes--a case of large granular lymphocytosis with characteristic cell surface antigens].

A 58-year-old male visited the hematological clinic of Surugadai Nihon University Hospital, Tokyo, complaining of numbness around both elbows. The peripheral leukocyte count was 12,400/microliters, and large granular lymphocytes (LGL) occupied 79% of the leukocytes. The cell surface antigen studied by flow cytometry were the positive CD 2, 3, 5, 8, 11, and Leu-7, and the negative CD1, 4, 10, 16 (Leu-11), 19, 20, and OKTIa1. IgG-FCR checked by mean of the EA-rosette formation was positive. The LGL showed the negative NK cell activity and the positive ADCC and LAK cell activities. It was interesting that LGL was negative for CD16 (Leu-11) while they had ADCC activity. Since the rearrangement of the receptor gene in T-cells was demonstrated by the southern blot analysis, the proliferation of LGL was considered to be a clonal one. LGL did not inhibit the colony formation of granulocyte and erythrocyte precursors in the plasma clot culture. It was thus considered that this might partially explain the fact that the patient's neutrophil, Hb and platelet levels remained normal.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1987

Increase in insulin binding affinity by chloroquine in cultured rat hepatoma cells.

Chloroquine increased the binding of 125I-labeled insulin to rat hepatoma cells (R-Y121B) at 4 degrees C. The effect of chloroquine on insulin binding was amplified at 23 degrees C, and a large increase in cell-associated radioactivity was observed. Scatchard analysis showed that chloroquine increased the affinity of insulin for cells at both 4 degrees C and 23 degrees C, and that this increase eventually caused the accumulation of insulin internalized by cells at 23 degrees C.

Animals↗
PubMed1987

Concanavalin A changes not only the number of insulin binding sites but also the binding affinity in rat hepatoma cells in culture.

When rat hepatoma cells (R-Y121B) were first incubated with labeled insulin, followed by concanavalin A, at 500 micrograms/ml at 23 degrees C, the total cell-associated radioactivity increased. At 4 degrees C, however, this increase was not observed. Scatchard analysis revealed that concanavalin A increased insulin binding affinity. The bound insulin was internalized together with concanavalin A. When the cells were incubated with concanavalin A prior to insulin addition, however, the total cell-associated radioactivity decreased at both temperatures. This was caused by the masking of insulin binding sites by the lectin.

Animals↗
PubMed1987

Platelet-activating factor stimulates metabolism of phosphoinositides via phospholipase A2 in primary cultured rat hepatocytes.

Addition of platelet-activating factor (PAF) to cells doubly labeled with [14C]glycerol plus [3H]arachidonic acid resulted in a transient decrease of [14C]glycerol-labeled phosphatidylinositol (PI) and a transient increase of [14C]glycerol-labeled lysophosphatidylinositol (LPI). [3H]Arachidonate-labeled PI, on the other hand, decreased in a time-dependent manner. The radioactivity in phosphatidylethanolamine, phosphatidylcholine, sphingomyelin, and phosphatidylserine did not change significantly. The 3H/14C ratio decreased in PI in a time-dependent manner, suggesting the involvement of a phospholipase A2 activity. Although PAF also induced a gradual increase of diacylglycerol (DG), the increase of [14C]glycerol-labeled DG paralleled the loss of triacyl [14C]glycerol and the 3H/14C ratio of DG was 16 times smaller than that of PI. Thus, DG seemed not to be derived from PI. In myo- [3H]inositol-prelabeled cells, PAF induced a transient decrease of [3H]phosphatidylinositol-4,5-bis-phosphate (TPI) and [3H]phosphatidylinositol-4-phosphate (DPI) at 1 min. PAF stimulation of cultured hepatocytes prelabeled with 32Pi induced a transient decrease of [32P]polyphosphoinositides at 20 sec to 1 min. [32P]LPI appeared within 10 sec after stimulation and paralleled the loss of [32P]PI. [3H]Inositol triphosphate, [3H]inositol diphosphate, and [3H]inositol phosphate, which increased in a time-dependent manner upon stimulation with adrenaline, did not accumulate with the stimulation due to PAF. These observations indicate that PAF causes degradation of inositol phospholipids via phospholipase A2 and induces a subsequent resynthesis of these phospholipids.

Animals↗