Biomedical subjects

K Takada

Publications and source records attributed to K Takada.

At least 397 records · Page 22Linked to original sources

PubMed1994

Effects of intralesional injection of cisplatin dissolved in urografin and lipiodol on Ehrlich ascites tumor and normal tissues of CD-1 mice.

The response of Ehrlich ascites tumor and the effect on normal tissues (kidney and small intestine) of CD-1 mice were evaluated after intralesional (i.l.) injection of cisplatin dissolved in urografin and lipiodol, which is henceforth termed CUL suspension. The results obtained were compared with the effects of i.p. and i.l. injections of cisplatin dissolved in sterile distilled water. Each of these treatment modalities involves the injection of 10 mg/kg cisplatin. The tumor response was evaluated by tumor growth-delay studies as well as by determining the percentage of cells in the S phase. Toxicity studies were accomplished by evaluation of the change in the body weight of mice and also by S-phase studies. S-phase fraction analyses were done with the use of the Cell Proliferation Kit. This commercial kit was used to measure bromodeoxyuridine (BrdU), a thymidine analogue that is incorporated into cells synthesizing DNA. Tumor, kidney, and small-intestine platinum concentrations were determined by measurement with a flameless atomic absorption spectrophotometer. The results of the tumor growth-delay studies showed that i.p. injection, with water being the drug carrier, produced the weakest antitumor effect, whereas i.l. injection of cisplatin, with lipiodol being the drug carrier, evoked the most enhanced effect. This finding was substantiated by BrdU-uptake analysis of tumor cells, wherein i.p. injections yielded the highest S-phase fraction and CUL treatment gave the lowest. Toxicity studies showed that a very significant decrease in body weight occurred in mice receiving i.p. treatment. No significant decrease in body weight was noted after i.l. treatment. BrdU analysis revealed that DNA synthesis in kidney cells and crypt cells of the small intestine was depressed after i.p. treatment. On the other hand, no significant effect was observed in the kidney or small intestine of CUL-treated mice. A correlation between the effects of the various treatment modalities (on tumors, kidney, and small intestine) and the retention of cisplatin was found.

Animals↗

PubMed1994

Ubiquitin and ubiquitin-protein conjugates in PC12h cells: changes during neuronal differentiation.

Ubiquitin and ubiquitin-protein conjugates in PC12h cells were detected with in vitro [125I]ubiquitination, and quantified by immunoblotting. These levels were altered by nerve growth factor (NGF), which promotes neuronal differentiation. (i) Levels of high molecular weight (HMW) ubiquitin-protein conjugates ranging from 40 to 1,000 kDa were increased by 2 days of NGF treatment, and remained high up to 10 days of NGF treatment. (ii) Ubiquitin and a 23-kDa conjugate tended to be decreased from days 2 to 10 of NGF treatment. 10-Day culture with 10 nM staurosporine, n protein kinase inhibitor, that blocks NGF-induced neurite outgrowth suppressed the NGF-induced increases in levels of HMW conjugates. Cyclic AMP and forskolin, both of which promote neurite outgrowth, mimicked the NGF-induced changes in ubiquitin and HMW conjugates, but phorbol ester and epidermal growth factor had little effect. These findings suggest that changes in ubiquitin-protein conjugates are closely coupled with neuronal differentiation.

Alkaloids↗

PubMed1994

Pyridoxal kinase immunoreactivity in rabbit brain.

Murine polyclonal antibody against purified bovine brain pyridoxal kinase (EC 2.7.1.35) was generated and showed cross-reactivity with rabbit brain pyridoxal kinase. This antibody was used to immunohistochemically examine the distribution of pyridoxal kinase in the rabbit brain. The cytoplasm of neuronal cells and neuroglial cells in the cerebral cortex, hippocampal region, brain nuclei and cerebellar cortex showed positive staining with various degrees of intensity. The neuronal cells and surrounding fibers in some brain nuclei, such as the area tegmentalis ventralis or the substantia nigra, showed intense staining. The neuronal cells of the hippocampal region showed somewhat weak reactivity, but some with intense reactivity were found sparsely distributed and positive staining fiber networks of a very low density were also observed.

Animals↗

PubMed1994

Release of fibroblast growth factor-1 by human squamous cell carcinoma correlates with autocrine cell growth.

A squamous cell carcinoma cell line Nakata proliferated in serum-free culture and was not responsive to exogenous fibroblast growth factor-1 (FGF-1). Immunostaining revealed that Nakata cells expressed FGF-1 in their cytoplasms and nuclei. Two molecular mass species of FGF-1 (16 and 18 kDa) were identified in cell extracts by Western blot. These cells also expressed high-affinity FGF-1 binding sites (Kd = 360 pM, 28,000 sites/cell). The results of cross-linking with [125I]FGF-1 demonstrated the presence of two bands with molecular masses of 160 and 140 kDa. The addition of FGF-1 specific antisense oligonucleotides at 25 microM to Nakata cells resulted in an 82% inhibition in cell growth and suppressed FGF-1 expression. This effect was dose-dependent and specific, because sense oligonucleotides were ineffective in inhibiting cell growth. In addition, Nakata cell growth was suppressed by an anti-FGF-1 neutralizing antibody, which resulted in a 52% inhibition at 8 micrograms/ml. These results demonstrate that Nakata cells produce FGF-1, and indicate that this growth factor acts in an autocrine manner by interacting with FGF-1 binding sites on Nakata cells.

Base Sequence↗

PubMed1994

The effects of food consistency on jaw movement and posterior temporalis and inferior orbicularis oris muscle activities during chewing in children.

The possible effects of food consistency on the number of chews and the lapse of time in a chewing sequence, the jaw-movement pattern and velocity, and jaw and lip muscle activity during chewing were investigated. Fifteen healthy children with good occlusion were selected. First, each subject freely chewed hard (HJ) and soft (SJ) types of jelly without specifying the chewing side. The number of chews and elapsed time in a masticatory sequence (from the start of chewing to the completion of the final swallow) were measured. Second, the subjects performed right- and left-sided chewing of the same food. The electromyograms (EMG) of posterior temporalis (PT) and inferior orbicularis oris (OI) muscles on the right and left sides and associated jaw movement records were sampled. The HJ was chewed more times and with a longer time until finally swallowed (p < or = 0.0007) than the SJ. The HJ chewing also showed broader masticatory loops (p < or = 0.0199) in the frontal view and higher peak activities (p < or = 0.0007) for the PT muscle. The closing phase was longer when chewing the HJ than SJ, but the opening and intercuspal phases remained stable. More lateral excursion of the jaw was seen when chewing the HJ, but the jaw-movement trajectories in the sagittal and vertical directions were not affected by the change in consistency of the food. The jaw-closing velocities for the HJ chews were significantly slower (p < or = 0.0351) than those for the SJ chews in three directions. The HJ chews also revealed a longer duration between the onset of EMG burst for the PT muscle and the beginning of the centric occlusion (p < or = 0.0146). The OI muscle showed increased activity in accord with jaw opening, and consistent reciprocal cyclic activity with the PT muscle in terms of temporal associations (r > or = 0.5250; p < or = 0.0495). The OI muscle started to burst at a later part of the intercuspal phase, and frequently showed secondary activity in the jaw-closing and intercuspal phases. The peak activity for the ipsilateral OI muscle was significantly higher (p < or = 0.0106) than that for the contralateral OI muscle for both the HJ and SJ. The OI muscle activity, however, did not differ between the hard and soft jellies.(ABSTRACT TRUNCATED AT 400 WORDS)

Child↗

PubMed1994

Staurosporine can inhibit the G1-S transition induced by a calcium channel agonist by blocking the pathway independent of phorbol ester-sensitive protein kinase C in rat thyroid cells (FRTL-5).

IGF-I, when added to TSH-primed FRTL-5 cells, can induce a long lasting Ca2+ influx followed by the DNA synthesis. BAY K8644, a Ca2+ channel agonist, can also induce the DNA synthesis in TSH-treated cells. Staurosporine, which is known to be a potent inhibitor of protein kinase C(PKC) strongly inhibited the DNA synthesis caused by these two reagents. However, in PKC-down regulated cells, IGF-I and BAY K8644 could also evoke the DNA synthesis and the inhibitory effect of staurosporine persisted. These inhibitory effects did not relay on inhibition of the Ca2+ influx induced by BAY K8644. Thus these results demonstrate that staurosporine acts at a point distal to Ca2+ influx to inhibit G1-S transition and this staurosporine-sensitive pathway possibly mediates the mitogenic signal in PKC-independent manner.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1994

Porphyromonas gingivicanis sp. nov. and Porphyromonas crevioricanis sp. nov., isolated from beagles.

Two new species, Porphyromonas gingivicanis and Porphyromonas crevioricanis, are proposed for black-pigmented, asaccharolytic, anaerobic, nonmotile, non-spore-forming, gram-negative, rod-shaped organisms. These organisms were isolated from the gingival crevicular fluids of beagles. P. gingivicanis and P. crevioricanis do not grow in the presence of 20% bile. They exhibit less than 5% DNA-DNA homology with the type strains of Porphyromonas gingivalis (strain ATCC 33277), Porphyromonas endodontalis (strain ATCC 35406), and Porphyromonas asaccharolytica (strain ATCC 25260), which were isolated from humans, or with the type strains of Porphyromonas salivosa (strain NCTC 11632) and Porphyromonas circumdentaria (strain NCTC 12469), which were isolated from cats. The major cellular fatty acid of P. gingivicanis and P. crevioricanis is 13-methyltetradecanoic acid (iso-C15:0 acid). Glutamate and malate dehydrogenases are present in both species, and 6-phosphogluconate and glucose-6-phosphate dehydrogenases are absent; neither organism exhibits trypsin activity. P. gingivicanis and P. crevioricanis produce large amounts of acetic and isovaleric acids and minor amounts of isobutyric and succinic acids as end products of metabolism in GAM medium. P. gingivicanis also produces large amounts of butyric acid and small amounts of propionic acid, while P. crevioricanis produces large amounts of propionic acid and minor amounts of butyric and phenylacetic acids. The G+C contents of the DNA of P. gingivicanis is 41 to 42 mol%; the G+C content of the DNA of P. crevioricanis is 44 to 45 mol%. Catalase is produced by P. gingivicanis but not by P. crevioricanis; strains of P. crevioricanis agglutinate sheep erythrocytes, but strains of P. gingivicanis do not.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Successful treatment of transfusion-associated graft-versus-host disease.

We present an immunocompetent patient with transfusion-associated graft-versus-host disease (GVHD), in which chimaerism of peripheral blood lymphocytes was demonstrated by analysis of a highly polymorphic genome. The patient was treated successfully with anti-CD3 monoclonal antibody, OKT3 and cyclosporin A. Although it is undoubtedly important to prevent transfusion-associated GVHD by irradiation of cellular blood components, intensive therapy with OKT3 and cyclosporin A in the early phase of onset may be effective for treatment of this potentially fatal condition. The mechanism of the effectiveness of this treatment for transfusion-associated GVHD is discussed.

Adult↗

PubMed1994

The prevalence of cardinal TMJ dysfunction symptoms and its relationship to occlusal factors in Japanese female adolescents.

Cross-sectional data were obtained from 1182 Japanese high school girls of 12 and 15 years old. The data were analysed for the prevalence of specific occlusal features and the prevalence of cardinal Temporomandibular Joint Dysfunction (TMJD) symptoms in different occlusion groups. The associations between occlusal features and TMJD symptoms were analysed by the Z-analysis. The results were as follows: the prevalence of TMJD symptoms (total) was about 23% in both age groups examined. Noise had the highest prevalence of the specific TMJD symptoms in both age groups (16% and 11%). With age and for different occlusion groups, there was a significant increase in deviation on opening (P < 0.001) and a decrease in pain and noise (P < 0.05). No significant associations were found between the occurrence of TMJD symptoms (total) and occlusal features in all the examined occlusion groups. With respect to specific TMJD symptoms, however, the investigation of the different groups revealed a significant association (P < 0.05) of intra-arch occlusal (crowding) features with the occurrence of deviation on opening and with the occurrence of the combined TMJD symptoms which include deviation on opening. This indicates that crowding may be an important sign for predisposing TMJD. For the other single disorder symptoms (except pain), we did not find a significant relationship (P < 0.05) with aspects of occlusion, which may confirm a multifactorial TMJD problem wherein occlusal features can have a contribution to TMJD.

Adolescent↗

PubMed1994

Involvement of transforming growth factor-beta 1 for platelets-induced stimulation of endothelin-1 production.

1. Possible mechanisms by which platelets stimulate the production of endothelin-1 (ET-1) in vascular endothelial cells (EC) were investigated. 2. A supernatant of platelets stimulated the expression of prepro ET-1 mRNA, followed by an increased secretion of ET-1 from cultured EC. These responses were markedly enhanced by pretreatment of the platelets with thrombin, at a concentration which did not influence the ET-1 production in EC. A platelet suspension, separated from cultured EC by a permeable nylon membrane, also markedly stimulated the ET-1 secretion from EC. 3. Endothelin-1 production enhanced by the platelet supernatant, with or without thrombin pretreatment, correlated with the active transforming growth factor-beta 1 (TGF-beta 1) concentrations in the supernatant. The supernatant-induced increase in ET-1 secretion from the EC was markedly suppressed by TGF-beta 1 neutralizing antibody. 4. We tentatively conclude that platelets stimulate the endothelial ET-1 production by releasing a bioactive diffusible substance, mainly TGF-beta 1.

Animals↗

PubMed1994

Detoxification of lipopolysaccharide (LPS) by egg white lysozyme.

Recent studies carried out by our group suggest that lysozyme binds to bacterial lipopolysaccharide with a high affinity to produce a complex, and inhibits various biological activities of lipopolysaccharide. Although the basic structure of lipopolysaccharide is independent of the species and strains of Gram-negative bacteria, many structural factors such as O-antigenic polysaccharide, lipid A, substituted groups, and associated molecules, affect the biological activities of lipopolysaccharide. In this study, we prepared lysozyme/lipopolysaccharide complexes using various structures of lipopolysaccharide and compared the activity and physicochemical properties. Native and dansylated lysozyme were found to bind to all tested lipopolysaccharides. The mitogenic activity and TNF production by all tested lipopolysaccharides were significantly reduced by complex formation in vitro. Administration of the complex prepared by various lipopolysaccharides produced significantly less quantities of TNF in the septic shock model. These results suggested that binding of lysozyme to lipopolysaccharide is important for the host both in pathophysiological responses to lipopolysaccharides and in the modification of lipopolysaccharide biological activity.

Animals↗

PubMed1994

Immunocytochemical localization of fibroblast growth factor-1 (FGF-1) and FGF-2 in oral squamous cell carcinoma (SCC).

The localization of fibroblast growth factor-1 (FGF-1) and FGF-2 in human oral squamous cell carcinoma (SCC) was examined by immunohistochemical techniques using anti-FGF-1 and anti-FGF-2 monoclonal antibodies. Immunofluorescence staining of two oral SCC cell lines revealed that growing cancer cells were intensely positive for both FGF-1 and FGF-2, but confluent cells showed a faint immunostaining. In addition, two molecular mass species of FGF-1 (16 and 18 kDa) and one of FGF-2 (18 kDa) were identified by Western blot in cell extracts derived from growing SCC cells, but not from confluent SCC cells. The growing cell extracts significantly stimulated the proliferation of human umbilical vein endothelial cells. Immunoperoxidase staining of 13 oral SCC cases showed that both well-differentiated and poorly-differentiated cancer cells were positive for FGF-1 and FGF-2 with high frequency and intensity as compared to normal oral epithelium. These results indicate that SCC cells express high levels of endogenous FGF-1 and FGF-2, and suggest that these growth factors may contribute to cancer cell growth.

Antibodies, Monoclonal↗

PubMed1994

[Strongyloidiasis associated with multiple myeloma in Ehime prefecture].

A 76-year-old male with multiple myeloma, who was born and had lived in Ehime Prefecture was admitted to our hospital because of high fever. The chest X-p film showed right middle lobal pneumonia. Eosinophilia was detected and a stool smear examination revealed rhabditis form larvae of the nematode. The filaria form larvae of Strongyloides stercoralis were detected by stool culture. Antibiotics and pyruvinium pamoate were administered to bacterial pneumonia and hyperinfection of the strongyloides, respectively. Consequently, pneumonia and strongyloidiasis were promptly improved. It was considered that he was infected with strongyloides in south-east Asia during World-War II and a little autoinfection of this nematode had continued about 50 years. In addition, it was suggested that hyperinfection of strongyloides resulted from the immunosuppressive state induced by the chemotherapy for multiple myeloma.

Aged↗

PubMed1994

Binding of lysozyme to lipopolysaccharide suppresses tumor necrosis factor production in vivo.

Endotoxin (lipopolysaccharide [LPS]) released during gram-negative bacterial infection induces varieties of cytokines which directly and/or indirectly cause shock, disseminated intravascular coagulation, and death. We previously showed that lysozyme (LZM) was an LPS-binding protein and inhibited various immunomodulating activities of LPS. In this study, we examined the effect of LZM on the LPS-triggered septic shock model induced by carrageenan treatment and assessed by tumor necrosis factor production. The data presented in this report strongly suggest that LZM-LPS complex formation completely abrogates tumor necrosis factor production and the mortality caused by LPS and that LZM may be useful for the treatment of endotoxin shock.

Animals↗

PubMed1994

Isolation of Epstein-Barr virus (EBV)-negative cell clones from the EBV-positive Burkitt's lymphoma (BL) line Akata: malignant phenotypes of BL cells are dependent on EBV.

During cultivation of the Epstein-Barr virus (EBV)-positive Burkitt's lymphoma (BL) line Akata, it was noted that EBV DNA is lost from some of the cells. Isolation of EBV-positive and EBV-negative clones with the same origin made it possible to examine the effects of EBV in BL cells. The results indicate that malignant phenotypes of BL, such as growth in low serum, anchorage-independent growth in soft agar, and tumorigenicity in nude mice, are dependent on the presence of EBV genomes and underline the oncogenic function of EBV in human cancer.

Animals↗

PubMed1994

Interleukin-4 in chronic myelomonocytic leukemia. Growth suppression of hematopoietic precursors in the chronic phase and stimulation in the acute phase.

We examined the effects of interleukin-4 (IL-4) on the growth of hematopoietic precursors from a patient with chronic myelomonocytic leukemia (CMMoL). In the chronic phase of the disease, IL-4 inhibited spontaneous colony formation by CMMoL cells in semi-solid culture. However, in the acute phase, IL-4 promoted colony formation. These effects of IL-4 were abolished completely by the addition of anti-IL-4 neutralizing antibodies. The spontaneous colony formation by CMMoL cells in both the chronic and acute phases was inhibited by the addition of anti-IL-6 antibodies. On the other hand, neither anti-IL-6, anti-granulocyte macrophage colony-stimulating factor (GM-CSF), anti-IL-1 beta nor anti-tumor necrosis factor alpha (TNF alpha) antibodies inhibited IL-4-induced colony formation by CMMoL cells in the acute phase. IL-4 suppressed the production of IL-6 by CMMoL cells in both the chronic and acute phases. These results suggest that in the present patient, IL-4 suppressed the IL-6-mediated autocrine growth of CMMoL cells in both the chronic and acute phases, but directly stimulated their growth in the acute phase.

Antibodies↗

PubMed1994

Acute transformation of chronic large granular lymphocyte leukemia into an aggressive form associated with preferential organ involvement.

In most patients with large granular lymphocyte (LGL) leukemia, the disease appears to progress slowly if at all, and no therapy is generally required. We present a patient with CD3+ CD8+ CD16+ LGL leukemia, who showed a benign clinical course for more than 7 months without therapy, but subsequently developed aggressive disease. A feature of considerable interest was the transformation into an acute or aggressive form in this patient affected preferentially the liver and spleen, and was not associated with the hematologic features of the circulating leukemic cells, as assessed by morphologic, phenotypic and molecular analyses. The patient was treated with combination chemotherapy; this resulted in clinical remission with persistence of the abnormal clone in the peripheral blood. The mechanism responsible for the preferential organ involvement and the process of progression from the chronic to the acute form in this case are discussed from the viewpoint of a lymphoproliferative disorder.

Aged↗

PubMed1994

Decrease in vecuronium infusion dose requirements by nicardipine in humans.

This study was designed to analyze quantitatively the interaction of nicardipine with vecuronium using a constant infusion technique. Forty-seven patients undergoing elective otolaryngeal surgery were anesthetized with isoflurane (1% end-tidal) and nitrous oxide (67%). Patients were randomly assigned to receive one of four doses of nicardipine (0, 1, 2, and 3 micrograms.kg-1.min-1). Vecuronium infusion dose requirement was determined as a constant infusion rate which maintained 90% depression of control twitch tension. Nicardipine significantly decreased the vecuronium requirement in a dose-dependent manner, i.e., the vecuronium doses were 0.70 +/- 0.03, 0.55 +/- 0.04, 0.42 +/- 0.04, and 0.37 +/- 0.05 micrograms.kg-1.min-1 at nicardipine doses of 0, 1, 2, and 3 micrograms.kg-1.min-1, respectively. Nicardipine also reduced both the plasma concentration of vecuronium to maintain the 90% depression and the total plasma clearance of vecuronium. The reversal of the vecuronium effect with neostigmine was not influenced by nicardipine. The results indicate that the vecuronium infusion dose requirements are reduced as much as 53% by a clinical dose of nicardipine.

Adult↗