Search PubMed⌕ Search

Biomedical subjects

T Murata

Publications and source records attributed to T Murata.

At least 289 records · Page 16Linked to original sources
PubMed1998

[Analysis of tumor vascular density using the window chamber technique].

Vascular structure is indispensable for a tumor to maintain its growth. The structure also affects drug delivery over chemotherapy, and oxygen tension in the tissue during irradiation. Therefore, measuring the vascular density in the tumor will help to reach an expected level or to evaluate the effect of those therapies. Through previous observation, changes in vascular structure, like the vascular density, have been reported. However, the tissue was usually removed from the deceased animal and examined in the microscope. Not many studies have shown changes in one and the same animal's tissue. In this study, we used the dorsal flap window chamber technique, and observed changes in the development of vascular structure and vascular density in a tumor. Window chambers were attached to the backs of 3 rats, and they anesthetized every 24 hours for microscopic observation. Vascular growth in the tumor started 8 to 9 days after implantation. Their average vascular density was about 25%, and this ratio continued till necrosis started in the tumor. "Necrosis occurs in a tumor because its growth is so rapid that the vascular development can not maintain the same speed." This has been a kind of established theory. During observation, we recognized blood stagnation in vessels as the tumor grew, and the relationship between tumor size and its vascular density was significant (r = 0.926). Our data lead us to another conclusion that "Vascular growth is as fast as tumor growth, keeping a ratio of about 25%, but necrosis is caused by deficiency of blood flow circulation."

Animals↗
PubMed1998

[Effect on hepatic function of hepatic artery infusion chemotherapy using epirubicin and mitoxantrone for advanced hepatocellular carcinoma].

This study was designed to assess the effect of hepatic dysfunction from hepatic artery infusion (HAI) in advanced hepatocellular carcinoma (HCC). The patients were randomly assigned to receive epirubicin (n = 12, Epi group) or mitoxantrone (n = 14, Mito group) once every 4 weeks between 1992 and 1996. HCC patients were given 6-8 mg of mitoxantrone or 30-40 mg epirubicin. There was hepatic dysfunction in 27 patients after HAI, showing similarly elevated GOT, GPT, and total bilirubin. In the Epi group, the GOT value was slightly higher than in the Mito group, but it was not significant. After HAI chemotherapy, the GOT value showed a more than two-fold elevation. Six patients in the Epi group and 2 in the Mito group showed a significant difference. Our results indicated that mitoxantrone had less impact on hepatic function following HAI therapy.

Antibiotics, Antineoplastic↗
PubMed1998

Histological grading of malignancy correlates with regional lymph node metastasis and survival of patients with oral squamous cell carcinoma.

This study evaluated the effectiveness of certain clinical and pathologic parameters in prognosing in oral squamous cell carcinoma (O-SCC). Patients and Methods. We performed a univariate and multivariate analysis of 212 patients with O-SCC and thus determined the move valuable factors in making a prognosis. We then investigated the relationships among the various pathologic parameters and regional lymph node metastasis. Regarding the pathologic parameters, a multivariate analysis using Cox's proportional hazard model determined inflammatory infiltration, invasive tendency, necrotic tendency, mitotic figures, and vascular permeation to be significant and independent prognostic factors affecting O-SCC. In addition, such the pathologic parameters as the mode of invasion, cellular atypia, mitotic figures, a necrotic tendency and as invasive tendency all correlated with the occurrence of regional lymph node metastasis. These statistically estimated histological grading of malignancy was thus found to be clinically acceptable and useful in helping to make a prognosis of O-SCC patients.

Adult↗
PubMed1998

Retrovirus-mediated gene transfer to photocoagulation-induced choroidal neovascular membranes.

PURPOSE: To determine the feasibility of experimental gene transfer to laser-induced choroidal neovascular membrane (CNVM) in rats, with a retroviral vector containing the reporter construct beta-galactosidase (beta-gal). METHODS: Laser photocoagulation was used to induce CNVM in rats. To ascertain the duration of beta-gal expression in the CNVM, 23 rats received 10 burns (75 microm, 100 mW, 0.1 seconds) in their right eyes, and beta-gal expression was examined from day 3 to 4 months. In addition, 14 pigmented rats were treated with 3 photocoagulation burns in their right eyes. beta-gal vector was injected into the vitreous or subretinal space 2 days later. On day 14, fluorescein angiography was performed to detect choroidal neovascularization. Then, beta-gal expression in each photocoagulation-induced CNVM was examined by observing the exposed fundus of the eyes stained with the beta-gal substrate X-Gal. RESULTS: beta-gal expression was identified in the CNVM induced by photocoagulation from day 5 (16.2% +/- 6.8% of the lesions) to 4 months (3.7% +/- 2.4%). Histopathologic examination revealed beta-gal-transduced macrophages and spindle-shaped cells, which amounted to 1.12% +/- 0.58% (at 2 weeks) of the total cells in the CNVM. beta-gal expression was restricted to the CNVM, and there was no beta-gal transduction in surrounding normal retinochoroidal tissue. There was no correlation between choroidal neovascularization formation and beta-gal expression. CONCLUSIONS: The feasibility of gene transduction targeted to the photocoagulation-induced CNVM was demonstrated using retroviral vectors. By transducing functional genes, this model could be useful for investigating the possibility of gene therapy to inhibit formation of the CNVM in age-related macular degeneration.

Animals↗
PubMed1998

Estimation of tumor necrosis factor-alpha in the diagnosis, the prognosis and the treatment follow-up of oral squamous cell carcinoma.

This study evaluated usefulness of serum tumor necrosis factor-alpha (TNF-alpha) levels in the diagnosis and prognosis of oral squamous cell carcinoma (O-SCC). We performed a clinico-pathological estimation of 38 patients with O-SCC and determined the more valuable factors in making a prognosis. The mean serum concentration of TNF-alpha for the patients with O-SCC (14.13 +/- 13.17 pg/ml) was significantly higher (p < 0.05) than that of the healthy controls (3.49 +/- 2.97 pg/ml). The mean serum concentrations of TNF-alpha were significantly higher (p < 0.05) in the good-prognosis group (16.73 +/- 18.64 pg/ml) than in the poor-prognosis group (9.62 +/- 5.92 pg/ml). The survival curve revealed a better prognosis for patients with serum TNF-alpha-positive than for patients with serum TNF-alpha negative. There was a significant correlation (p < 0.05) with serum TNF-alpha levels and two tumor markers (SCCA, IAP). These results of the present study suggest that a evaluation of serum TNF-alpha levels in O-SCC is a valuable tool as a tumor marker for the diagnosis, prognosis and treatment monitoring of O-SCC.

Adult↗
PubMed1998

Manganese superoxide dismutase (Mn-SOD) correlates with prognosis of patients with oral squamous cell carcinoma.

In the present study, tissue manganese superoxide dismutase (Mn-SOD) activities were determined postoperatively as a means to gauge future prognosis in oral squamous cell carcinoma (O-SCC). We investigated the relationships among the various clinico-pathologic parameters and clinical course of 43 patients with O-SCC. The Mn-SOD activity in the cancerous tissues decreased with the healthy controls, but there was no significant difference between the patients with O-SCC and healty controls. There was no significant difference between tissue Mn-SOD activities and clinical stage. However, patients who presented metastatic lymph nodes (N 1 or N 2) exhibited higher tissue Mn-SOD activities than patients without metastatic lymph nodes. In the pathologic parameters, the tissue Mn-SOD activities of grade 4 C, 4 D group and high histological malignancy group were significant higher than those of other groups. The tissue Mn-SOD activities were significantly lower in the good-prognosis group than in the poor-prognosis group. These results of the present study suggest that a evaluation of tissue Mn-SOD activities in O-SCC is a useful prognostic factor for screening of patients with O-SCC.

Adult↗
PubMed1997

Carbohydrate analysis of porcine thyroglobulin isoforms with different iodine contents.

To further validate the relationship between thyroid hormone formation and the carbohydrate structure of thyroglobulin (Tg), we reinvestigated the relationship between the iodine content and the asparagine-linked oligosaccharide structures of porcine Tg. Purified porcine Tg was further separated into isoforms (Tg-F1, -F2 and -F3) with a DEAE-cellulose ion-exchange chromatography column. The iodine residues, neutral sugar and sialic acid were analyzed for the separated Tg isoforms and their asparagine-linked oligosaccharide structures were analyzed. The asparagine-linked oligosaccharides were released from Tg-F1, -F2 and -F3 by hydrazinolysis and each oligosaccharide was labeled with p-aminobenzoic acid octyl ester (ABOE). The ABOE-labeled oligosaccharides from Tg-F1, -F2 and -F3 were analyzed for their relative content in oligosaccharides of each structure type by chemical methods and DEAE- and ConA high-performance liquid chromatography (HPLC) columns. As a result, it was revealed that the Tg fraction eluted at higher ionic strength from a DEAE-cellulose column is apt to contain more of each iodoamino acid, as well as total content of iodine, larger negative zeta-potential, conforming to sialic acid content in the Tg molecule and to a higher content of di-sialo-bi-antennary complex and to high mannose type oligosaccharides. These results support the conclusion that iodine organification of the Tg molecule is correlated with asparagine-linked oligosaccharide completion.

Animals↗
PubMed1997

Purification and reconstitution of Na+-translocating vacuolar ATPase from Enterococcus hirae.

Vacuolar ATPases make up a family of proton pumps distributed widely from bacteria to higher organisms. An unusual member of this family, a sodium-translocating ATPase, has been found in the eubacterium Enterococcus hirae. We report here the purification of enterococcal Na+-ATPase from the plasma membrane of cells, whose ATPase content was highly amplified by expression of the cloned ntp operon that encodes this Na+-ATPase (ntpFIKECGABDHJ). The purified enzyme appears to consist of nine Ntp polypeptides, all the above except for the ntpH and ntpJ gene products. ATPase activity was strictly dependent on the presence of Na+ or Li+ ions and was inhibited by nitrate, N-ethylmaleimide, and the peptide antibiotic destruxin B. When the purified ATPase was reconstituted into liposomes prepared from Enterococcus faecalis phospholipids, ATP-driven Na+ uptake was observed; uptake was blocked by nitrate, destruxin B, and monensin, but it accelerated by carbonyl cyanide m-chlorophenylhydrazone and valinomycin. These data demonstrate that E. hirae Na+-ATPase is an electrogenic sodium pump of the vacuolar type. This is a promising system for research on the fundamental molecular structure and mechanism of vacuolar ATPase.

Adenosine Triphosphatases↗
PubMed1997

Structure of IL-13 receptor: analysis of subunit composition in cancer and immune cells.

The structure of IL-13 receptor (IL-13R) is currently under investigation. Recently, two different human IL-13R chains, termed here IL-13R alpha and -alpha' have been cloned. We have examined various cancer and normal cell lines for the presence of mRNA for IL-13R alpha and alpha, as well as IL-4R p140 (termed beta chain) and IL-2R gamma c chains. In renal cell carcinoma, glioblastoma and ovarian carcinoma (IGROV-1) cell lines, both IL-13R alpha and alpha chains were expressed (type I IL-13R). In epidermoid, colon, ovarian adenocarcinoma (PA-1) and normal mouse fibroblast (COS7) cell lines, only IL-13R alpha' was expressed (type II IL-13R). In hematopoietic TF-1 and EBV-immortalized normal B cell lines only IL-13R alpha' but not alpha chain was expressed along with gamma c (type III or type IV IL-13R). IL-13R alpha' chain was faintly detected in human T cells. All cells expressed the IL-4Rp140 beta chain. These data provide a direct support for our model of IL-13R which consists of three different forms composed of different subunits.

Animals↗
PubMed1997

Altered pain perception and inflammatory response in mice lacking prostacyclin receptor.

Prostanoids are a group of bioactive lipids working as local mediators and include D, E, F and I types of prostaglandins (PGs) and thromboxanes. Prostacyclin (PGI2) acts on platelets and blood vessels to inhibit platelet aggregation and to cause vasodilatation, and is thought to be important for vascular homeostasis. Aspirin-like drugs, including indomethacin, which inhibit prostanoid biosynthesis, suppress fever, inflammatory swelling and pain, and interfere with female reproduction, suggesting that prostanoids are involved in these processes, although it is not clear which prostanoid is the endogenous mediator of a particular process. Prostanoids act on seven-transmembrane-domain receptors which are selective for each type. Here we disrupt the gene for the prostacyclin receptor in mice by using homologous recombination. The receptor-deficient mice are viable, reproductive and normotensive. However, their susceptibility to thrombosis is increased, and their inflammatory and pain responses are reduced to the levels observed in indomethacin-treated wild-type mice. Our results establish that prostacyclin is an antithrombotic agent in vivo and provide evidence for its role as a mediator of inflammation and pain.

Animals↗
PubMed1997

Modulation of interleukin (IL)-13 binding and signaling by the gammac chain of the IL-2 receptor.

Interleukin (IL)-13 and IL-4 are cytokine products of TH2 cells which exert similar effects in a variety of cell types. We recently described IL-13R expression on human renal cell and colon carcinoma cells and demonstrated that gammac is not a component of IL-13R or IL-4R systems in these cells. In lymphoid cells such as B cells and monocytes, which respond to IL-13, gammac is a component of IL-4R but does not appear to be a component of IL-13R. Furthermore, while significant IL-13 binding is observed on carcinoma cells, IL-13 barely binds these lymphoid cells and the binding characteristics are different. To better understand the role of gammac in IL-13 binding and signaling, we have transfected a renal cell carcinoma cell line with gammac and examined IL-13 and IL-4 binding and signaling. IL-13 binding as well as IL-13 and IL-4 signaling through the JAK-STAT signaling pathway were severely inhibited. This inhibition was paralleled by a loss of expression of one of the IL-13R chains and intercellular cell adhesion molecule-1. Thus, although gammac has been shown to enhance IL-4 binding and function in some cell types, its influence on IL-13R function in tumor cells appear to be largely negative.

Enzyme Activation↗
PubMed1997

Interfacial State Change of Cellulose Triacetate Membrane by Adsorption of Polyelectrolyte

Lysozyme, albumin, and PAS-H (poly diallyl dimethyl ammonium chloride), which are positively and negatively charged proteins, and cationic polysulfones, respectively, were adsorbed by a cellulose triacetate (CTA) membrane to investigate their effects on ionic transport through the membrane. The interface states between the membrane and the adsorption layer are discussed based on the measurements of contact angle and membrane potential and atomic force microscopy (AFM). The contact angle shows that the membrane changed from hydrophobic to hydrophilic due to adsorption of the above substances. AFM imaged the aggregates on the surface and showed that lysozyme, in particular, penetrates the membrane pores, making them shallower and decreasing their porosity. The results of membrane potential measurements showed that lysozyme and albumin did not change the membrane charge state, but PAS-H changed it from negative to positive. The permeability coefficients of KCl and K2HPO4 varied significantly with the adsorption of each polyelectrolyte. In particular, the permeability coefficient of phosphate through the lysozyme-adsorbed membrane increased to twice that of the nonadsorbed membrane. Such polyelectrolyte adsorption on the membrane surface can be used for the modification of commercial artificial kidney phosphate extraction.

Journal Article↗
PubMed1997

Failure of parturition in mice lacking the prostaglandin F receptor.

Mice lacking the gene encoding the receptor for prostaglandin F2alpha (FP) developed normally but were unable to deliver normal fetuses at term. Although these FP-deficient mice showed no abnormality in the estrous cycle, ovulation, fertilization, or implantation, they did not respond to exogenous oxytocin because of the lack of induction of oxytocin receptor (a proposed triggering event in parturition), and they did not show the normal decline of serum progesterone concentrations that precedes parturition. Ovariectomy at day 19 of pregnancy restored induction of the oxytocin receptor and permitted successful delivery in the FP-deficient mice. These results indicate that parturition is initiated when prostaglandin F2alpha interacts with FP in ovarian luteal cells of the pregnant mice to induce luteolysis.

Animals↗
PubMed1997

Enzymic synthesis of 3'-O- and 6'-O-N-acetylglucosaminyl-N-acetyllactosaminide glycosides catalyzed by beta-N-acetyl-D-hexosaminidase from Nocardia orientalis.

beta-N-acetyl-D-hexosaminidase from Nocardia orientalis catalyzed the synthesis of beta-D-GlcNAc-(1 --> 3)-beta-D-Gal-(1 --> 4)-beta-D-GlcNAc-OC6H4NO2-p (1) and beta-D-GlcNAc-(1 --> 6)-beta-D-Gal-(1 --> 4)-beta-D-GlcNAc-OC6H4NO2-p (2) with its isomer beta-D-Gal-(1 --> 4)-[beta-D-GlcNAc-(1 --> 6)]-beta-D-GlcNAc-OC6H4NO2-p (3) through N-acetylglucosaminyl transfer from N-,N'-diacetylchitobiose to p-nitrophenyl beta-N-acetyllactosaminide. The enzyme formed a mixture of trisaccharides 1, 2, and 3 in a ratio of 11:33:56. In the case, when an inclusion complex of p-nitrophenyl beta-N-acetyllactosaminide with alpha-CD was used, compounds 1, 2, and 3 were formed in a molar ratio of 24:63:13. The regioselectivity of glycosidase-catalyzed formation of the trisaccharide glycosides was substantially changed. It resulted not only in a significant increase of the proportion of the desired compounds 1 and 2 but also in the substantial increase of the overall yield of transfer products.

Carbohydrate Sequence↗
PubMed1997

Co-localization of glucokinase with actin filaments.

A portion of glucokinase appeared to be co-localized with actin filaments in the cytoplasm of cultured rat hepatocytes incubated with 25 mM glucose. When liver- or islet-type glucokinase was transiently expressed in COS-7 cells, the expressed glucokinase was also co-localized with actin filaments in the cytoplasm of these transfected cells. Although co-localization of glucokinase with actin filaments was not clearly demonstrated in the pancreatic beta-cell line MIN6, islet glucokinase was found to be present in both the nucleus and the cytoplasm, though predominantly in the nucleus. These findings suggest that subcellular localization of glucokinase, including co-localization with actin filaments, may have an important physiological role in metabolic regulation.

Actins↗
PubMed1997

Parturition upregulates nitric oxide synthase activity in the rat anterior pituitary gland.

Recent evidence suggests that endogenous nitric oxide (NO) contributes to the modulation of hormonal secretion from the anterior pituitary gland according to the physiological state of the animal. In this study, nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and specific neurochemical assay were used to asses possible changes of NO synthase (NOS) activity in the anterior pituitary during pregnancy and parturition in rats. The anterior pituitary showed (weak) NADPH-d activity throughout pregnancy. Parturition increased the number and intensity of NADPH-d-positive cells. The NADPH-d-positive cells co-localized with immunofluorescent LH-positive cells. No variation in NADPH-d activity was apparent during the various stages of the oestrous cycle. Furthermore, NOS activity during parturition increased significantly when compared with non-pregnant and pregnant rats. Increases in both specific activity and NADPH-d activity gradually decreased within 24 h post-partum, suggesting that NO may modulate anterior pituitary function during parturition.

Animals↗