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Biomedical subjects

K Akiyoshi

Publications and source records attributed to K Akiyoshi.

At least 37 records · Page 2Linked to original sources

Isolated cavernous hemangioma of the stomach in a neonate.

This is a report of an extremely rare case of isolated cavernous hemangioma of the stomach found in a neonate. Hematemesis developed in a 7-day-old baby boy weighing 2.8 kg at birth. This was followed by melena. Endoscopic examination findings showed a large hemorrhagic mass on the lesser curvature of the stomach. During laparotomy, a large vascular tumor was identified and subtotal gastrectomy was carried out. On section, the tumor extended through the submucosa to the serosal surface. Histological diagnosis was cavernous hemangioma. The authors could collect only 10 cases of hemangioma of the stomach diagnosed in childhood from the world literature.

Gastrectomy↗

[Preliminary screening for antiviral AIDS drugs. VIII. Report for fiscal year 1995].

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 96 samples of different origin tested, two were shown to inhibit the growth of HIV in vitro. One of the positive samples (plant origin) has hopeful signs, as the ranges of effective doses are wider than those of most of positive samples which had been found by us.

Acquired Immunodeficiency Syndrome↗

0/w-emulsion of alpha-linolenic acid stabilized with hydrophobized polysaccharide. Its effect on the growth of human colon cancer cells.

To pursue a systemic administration of alpha-linolenic acid (ALA), which is a selective cytotoxic agent, we formulated an ALA o/w-emulsion stabilized by cholesterol-bearing pullulan (CHP-55-2.1) and trioctanoylglyceride (TriC8). This emulsion was stable even in the presence of bovine serum albumin (BSA). Peroxidation of ALA was drastically depressed by the emulsification using CHP. In addition, cytotoxic effect of the CHP/ALA/TriC8-emulsion against human colon cancer cell (RPM14788) was much higher than that of free ALA. However, no significant difference was observed in cell internalization efficiency of ALA between the two. These results suggest that difference in the cytotoxicity between the CHP/ALA/TriC8-emulsion and free ALA may come from difference in the intracellular behavior of ALA.

Caprylates↗

[Preliminary screening for antiviral AIDS drugs. VII. Report for fiscal year 1994].

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 246 samples of different origin tested, six were shown to inhibit the growth of HIV in vitro. Two of the positive samples have hopeful signs, as the ranges of effective doses are wider than those of most of positive samples which had been found by us.

Anti-HIV Agents↗

Interaction between ganglioside-containing liposome and rat T-lymphocyte: confocal fluorescence microscopic study.

Interaction between rat T-lymphocytes and a ganglioside (GM3, GD3, GT1b, or GQ1b)-containing liposome was investigated in vitro. The direct stimulation of T cell by a ganglioside-containing liposome was followed by monitoring an increase in the intracellular calcium signal using a confocal laser fluorescence microscopic method. The GT1b- or GQ1b-containing liposome strongly stimulated the cell, while the GM3- or GD3-containing liposome showed much less effect. Free gangliosides did not stimulate the cell at all under the same condition. The extent of the stimulation depended on the surface density of GT1b on the liposome accompanied by a clear threshold concentration. The efficiency of this direct T cell stimulation with the ganglioside-containing liposome was closely related to the efficiency of the tumor growth suppression reported previously by ourselves.

Aniline Compounds↗

Transfer of membrane proteins from human platelets to liposomal fraction by interaction with liposomes containing an artificial boundary lipid.

The direct transfer of membrane proteins from human platelets to the liposomal fraction was examined, particularly in relation to platelet activation during the process. The incorporation of an artificial boundary lipid, 1,2-dimyristoylamido-1,2-deoxyphosphatidylcholine (DDPC), in the interacting liposome considerably enhanced the efficiency of the protein transfer. The transfer proceeded with neither significant activation nor lysis of the platelet, and the activation of the platelet with thrombin did not affect the amount of the transferred proteins. A wide range of platelet membrane proteins was transferred, and they were almost comparable to those in a sample prepared by glycerol lysis/centrifugation. In addition, they included the major surface glycoproteins GPIIb and GPIIIa without noticeable contamination of soluble cytosol proteins. The protein transfer method is a one-pot process and clearly more convenient than the conventional 'extract and reconstitute' approach. These results strongly support the use of the transfer process, especially with DDPC, as an alternative to the conventional detergent-solubilization or the solvent-extraction methods for preparation of samples of platelet membrane proteins.

Blood Platelets↗

Partition of polysaccharide-coated liposomes in aqueous two-phase systems.

Hydrophobized polysaccharides such as cholesterol-bearing pullulan (CHP), dextran (CHD) and mannan (CHM) effectively coat the liposomal surface. Partition of the hydrophobized polysaccharide-coated liposomes in an aqueous two-phase system (PEO (top)/pullulan (bottom) or PEO (top)/dextran (bottom)) was investigated (PEO = poly(ethylene oxide)). Conventional liposomes without a polysaccharide coat mostly locate at the interface between the two polymer phases. The polysaccharide-coated liposomes, on the other hand, were partly partitioned to the bottom polysaccharide phase depending on the structure of the hydrophobized polysaccharide on the liposomal surface. The affinity between the polysaccharide on the liposomal surface and that in the bulk bottom phase controls the efficiency of partition. The sequence of interaction strength between the two carbohydrates was the following: for the PEO/dextran two-phase system, dextran(liposome)-dextran(bulk) > mannan(liposome)- dextran(bulk) > pullulan(liposome)-dextran(bulk); while for the PEO/pullulan system, the sequence of interaction strength was pullulan(liposome)- pullulan(bulk) > dextran(liposome)-pullulan(bulk) approximately mannan(liposome)-pullulan(bulk).

Carbohydrate Conformation↗

Induction of in vitro and in vivo anti-tumor responses by sensitization of mice with liposomes containing a crude butanol extract of leukemia cells and transferred inter-membranously with cell-surface proteins.

Generation of cytotoxic T lymphocytes (CTL) in vitro and tumor-rejection responses by sensitization of semi-syngeneic mice with tumor-antigen-reconstituted liposomes were investigated. Liposomes were prepared from a crude butanol extract (CBE) of BALBRVD leukemia cells and egg phosphatidylcholine (PC): 1,2-dimyristoylamido-1,2-deoxyphosphatidylcholine (DDPC) (3:2) or dimyristoylphosphatidylcholine (DMPC):DDPC (1:4). Inter-membrane protein transfer (IMPT) liposomes were prepared by incubating BALBRVD cells with DMPC:DDPC (1:4) liposomes. Sensitization of male CB6F1 mice with CBE or IMPT liposomes induced a level of cytotoxicity similar to that on sensitization with mitomycin-C(MMC)-treated BALBRVD against BALBRVD target cells after in vitro sensitization with the tumor cells. Sensitization with CBE alone resulted in only marginal cytotoxicity. The cytotoxic effector cells induced by either mode of sensitization were CD8+ T-cells whose recognition was Kd-restricted. No difference in specificity was observed with the different modes of sensitization. Two in vivo immunizations with CBE or with CBE liposomes at a dose of 25 micrograms of protein (equivalent to 2.5 x 10(7) cells) cause moderate inhibition of BALBRVD tumor growth in male CB6F1 mice and immunization with IMPT liposomes at a dose of 1 microgram of protein result in efficient protection.

1-Butanol↗

Priming for in vitro and in vivo anti-human T lymphotropic virus type 1 cellular immunity by virus-related protein reconstituted into liposome.

In vitro and in vivo anti-human T lymphotropic virus type 1 (HTLV-1) cellular immunity was examined by immunizing rats with a truncated hybrid protein (228 amino acids) of gag and env of HTLV-1 produced by Escherichia coli. Animals were immunized with the hybrid protein reconstituted into mannan-derivative-coated liposomes (gag-env-lipo). In vitro sensitization with a HTLV-1-positive cell line, TARS-1, of spleen cells obtained from these animals generated killer cells specific for syngeneic HTLV-1-positive cells. No killer activity was generated when spleen cells were obtained from animals immunized with the hybrid protein alone, the liposome alone, or the hybrid protein reconstituted into conventional liposomes with no polysaccharide coating. Killer cells were CD8+ CTL restricted to MHC class I. Analysis of CD8+ and CD4+ subsets in spleens showed the existence of primed CD8+ T cells in animals immunized with gag-env-lipo. Rats immunized with gag-env-lipo displayed accelerated rejection of TARS-1 but not of two other HTLV-1-negative tumor lines. Injection of carrageenan into animals strongly inhibited generation of killer cells, which indicates the necessity of macrophages for priming of CD8+ T cells with gag-env-lipo. Injection of carrageenan also cancelled in vivo immunity against HTLV-1+ cells induced with gag-env-lipo. These results, taken together, indicate that exogenous protein reconstituted into appropriate liposomes can effectively prime MHC class I restricted CD8+ T cells in vivo with macrophage dependency.

Animals↗

Immunoglobulin production stimulating factor-II alpha (IPSF-II alpha) is glyceraldehyde-3-phosphate dehydrogenase like protein.

Amino acid sequence of the 36 KD protein which is the active subunit of immunoglobulin production stimulating factor-II alpha (IPSF-II alpha) derived from Burkitt's lymphoma Namalwa cells was analyzed for the 20 amino acids from N-terminus. The N-terminal amino acid sequence of this protein coincided very closely with glyceraldehyde-3-phosphate dehydrogenase (GPD; EC 1.2.1.12) derived from various origins. Especially, it was completely homologous with that of human liver GPD. Several GPD's derived from human erythrocyte, rabbit muscle and Bacillus stearothermophilus also stimulated IgM production of hybridomas, as well as IPSF-II alpha. Conversely, IPSF-II alpha had GPD enzymic activity as strong as rabbit muscle and B. stearothermophilus, and stronger than human erythrocyte GPD. These results suggested that 36 KD subunit of IPSF-II alpha was a GPD, or GPD like protein. The level of mRNA for IgM was not enhanced by IPSF-II alpha in hybridoma cells, though the IgM productivity of the cell was remarkably stimulated by the protein, indicating that IPSF-II alpha does not stimulate immunoglobulin production by enhancement of transcription.

Amino Acid Sequence↗

Interleukin-4 gene expression and IgE responsiveness.

Interleukin-4 (IL-4) gene expression by stimulation with concanavalin A (Con A) in murine spleen cells was examined. The amount of IL-4 mRNA induced by Con A was greatest in spleen cells obtained from IgE high responder strains of mice. A trace amount of IL-4 mRNA was induced in spleen cells from IgE low responder (SJL) mice. The amount of IL-4 mRNA induced in spleen cells from an IgE intermediate responder (C57BL/6) was smaller than that from high responders, but significantly greater than that from low responders. Spleen cells from IgE nonresponders (SJA/9) developed only a negligible amount of IL-4 mRNA. IL-4 mRNA was detected in human peripheral blood mononuclear cells (PBMC) stimulated with Con A. The IL-4 gene expression seemed to be greater in PBMC obtained from highly atopic patients and was decreased in PBMC from individuals showing hypo-IgE immunoglobulinemia (less than 10 IU/ml). The results obtained in the present study may indicate that high and low IgE responder traits are determined depending on their levels of IL-4 mRNA expression.

Animals↗

[An unusual association of transient resolving thyrotoxicosis due to painless thyroiditis, hypopituitarism and central diabetes insipidus associated with spontaneous pituitary apoplexy].

Pituitary apoplexy is characterized by a wide spectrum of clinical features. A quite rare case of painless thyroiditis, hypopituitarism and central diabetes insipidus (DI) followed by pituitary apoplexy was presented. A 61-year-old woman was admitted to our hospital in May, 1986 because of marked general malaise, polydipsia and weight loss which became progressively worse. Four months earlier she had experienced episodes of abrupt onset of severe headache associated with nausea and blurring vision. Physical examinations revealed a fine tremor, dry skin and nervousness. The thyroid gland was not palpable. Visual fields were intact. Her blood pressure was 105/64 mmHg with variable tachycardia. The routine laboratory studies were normal or negative except for hypoalbuminemia, hypocholesterolemia and hypernatremia. Erythrocyte sedimentation rate was 12 mm/hr. An impairment in corticotropin secretion was suspected from the low plasma cortisol and the low urinary excretion of 17-OHCS and the sufficient response to ACTH. Basal levels of GH and gonadotropin were also low, and responses to the stimulation tests (Insulin-stress, L-DOPA, and LH-RH) were all blunted. Brain computed tomographic scan and magnetic resonance imaging demonstrated a suprasellar mass that, after infusion, developed peripheral ring-like enhancement and large hyperintense pituitary mass, respectively. A diagnosis of pituitary apoplexy with anterior pituitary failure was made. However, the initial levels of thyroid hormones showed elevated as follows: Free T3 7.6 pg/ml, Free T4 3.3 ng/dl and T3-resin uptake 41.1%. TSH responses to TRH were all suppressed. TSH receptor antibody (TBII) was negative. Both antithyroglobulin and antimicrosomal antibodies were repeatedly positive. A thyroid scan with 99mTc revealed no uptake in the thyroid area. These findings led us to the diagnosis of "painless autoimmune thyroiditis". She had become hypothyroid without any medication. At that time radioactive 99mTc and 123I uptakes increased significantly. When hydrocortisone was substituted, daily urine output abruptly increased to about 10 liters with low osmolality, and the presence of DI was suspected. This diagnosis was confirmed by water deprivation and hypertonic saline infusion tests and subsequent pitressin test. She is currently quite well on L-thyroxine, hydrocortisone and desmopressin (1988). This association with pituitary apoplexy must be a rare occurrence, as a literature search has failed to find a similar case. The pathogenetic trigger of "painless thyroiditis" in this case may be responsible for some immunological change due to secondary adrenal insufficiency after pituitary apoplexy.

Diabetes Insipidus↗

Topical application of the hypoglycemic agent glibenclamide and changes in blood glucose, plasma insulin (IRI) levels and plasma concentration of glibenclamide in normal rats.

This study was done to determine whether an oral hypoglycemic agent would be absorbed through the skin and consequently lower blood glucose levels. We applied 250 mg or 500 mg of 5% glibenclamide ointment (GO) to the cleanly shaved dorsa (5 x 10 cm) of overnight-fasted male Wistar rats, weighing 250-300 g. Blood samples were collected at 1, 3, 6, 12 and 24 h after the application of GO and blood glucose, plasma insulin (IRI) and the plasma concentration of glibenclamide were determined. The plasma concentration of glibenclamide reached a high level as early as 1 h after application and the level was maintained for 24 h. The plasma concentration of glibenclamide in the 500-mg GO group was higher than in the 250-mg GO group, but even 24 h after application the 250-mg GO group showed a mean value of 206 ng/ml. Mean blood glucose levels in both GO groups at every time point after application were significantly lower than in the control group; with respect to mean IRI levels the opposite was found. Thus, glibenclamide is absorbed through the skin and reaches a level of plasma concentration which induces significant changes in blood glucose and IRI levels. This may well be a new approach to controlling blood glucose levels in patients with diabetes mellitus.

Administration, Topical↗