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Biomedical subjects

T Kawase

Publications and source records attributed to T Kawase.

At least 199 records · Page 11Linked to original sources
PubMed1992

Aluminum fluoride induces a reversible Ca2+ sensitization in alpha-toxin-permeabilized vascular smooth muscle.

The mechanism of aluminumfloride (AlF)-induced Ca2+ sensitization was explored in alpha-toxin-permeabilized rabbit mesenteric artery. In the presence of 0.18 microM Ca2+ and deferoxamine, a strong chelator of aluminum (Al3+), fluoride (F-; applied in the form of NaF) induced very slow tension development, while in the presence of tracer levels of Al3+ tension developed rapidly possibly due to formation of Al-F complexes (especially AlF4-). As a result, AlF significantly shifted the relationship between tension development and free Ca2+ concentration in the Ca(2+)-EGTA buffer (pCa-tension curve) to the left. The rate of the tension development also depended on the EGTA concentration: increasing the EGTA concentration from 0.5 to 10 mM markedly decreased the maximal rate of contraction ((dT/dt)max), probably due to chelation of Al3+ by EGTA, without effect on the maximal tension (delta Tmax). The AlF-induced Ca2+ sensitization could be reversed by extensive washing with relaxing solution (pCa greater than 8), in contrast to the contractions induced by guanosine 5'-[gamma-thio]triphosphate (GTP gamma s; a non-hydrolyzable GTP analogue) or phorbol 12,13-dibutyrate (PDBu) which were irreversible. However, the action of all the compounds appeared to be mediated through a H-7 (1-[5-isoquinolinesulfonyl]-2-methylpiperazine dihydrochloride)-sensitive pathway, and no additive effects among them were observed. In addition, GDP increased (dT/dt)max due to AlF without changing delta Tmax, whereas guanosine 5'-[beta-thio]diphosphate (GDP beta s; a non-hydolyzable GDP analogue) decreased both parameters. These findings suggest that AlF acts on G-proteins to enhance Ca2+ sensitivity of contractile elements through a H-7-sensitive pathway.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Inhibition of hepatic metastasis of colon carcinoma by asialo GM1--positive cells in the liver.

This study investigates the role of hepatic asialo GM1-positive cells in inhibiting hepatic metastasis of colon carcinoma (colon adenocarcinoma 38) in mice after administration of a biological response modifier, streptococcal derivative (OK432). Administration of OK432 increased the number of asialo GM1-positive cells in the liver, enhanced natural killer activity of hepatic mononuclear cells and reduced the number of hepatic metastases of colon carcinoma inoculated into the superior mesenteric vein. Administration of antiserum against asialo GM1 reduced the number of hepatic asialo GM1-positive cells, abolished natural killer activity of hepatic mononuclear cells and increased the number of hepatic metastases. In addition, administration of antiserum against asialo GM1 even after OK432 treatment also decreased the number of asialo GM1-positive cells, reduced natural killer activity of hepatic mononuclear cells and increased the number of hepatic metastases of colon carcinoma. However, administration of gadolinium chloride, which suppresses phagocytic function of Kupffer cells, did not influence the natural killer activity of hepatic mononuclear cells or the number of hepatic metastases. In vivo tumor-neutralization assay revealed that tumor growth was inhibited by the hepatic mononuclear asialo GM1-positive cells, but not by T lymphocytes or Kupffer cells after OK432 administration. These results suggest that an increased number of hepatic asialo GM1-positive cells after administration of OK432 plays an important role in protecting against metastasis of colon carcinoma in the liver.

Animals↗
PubMed1992

Effect of ipriflavone and estrogen on the differentiation and proliferation of osteogenic cells.

The effect of ipriflavone (IP) on the proliferation and differentiation of rat osteoblast-like (ROB) cells and human periodontal ligament fibroblasts (HPLF) was studied in the presence and absence of estrogen. ROB cells were isolated from newborn rat calvaria by sequential collagenase digestion and HPLF from the outgrowth of human periodontal ligament in culture. The alkaline phosphatase (ALP) activity, employed as a marker of bone cell differentiation, was significantly enhanced by IP in both cell types; however, the concentration at which IP had a maximal effect was lower in ROB cells than in HPLF (10(-10) versus 10(-7) M, respectively). Cell proliferation judged by DNA content was either constant (ROB cells) or slightly increased (HPLF) by IP up to 10(-10) M, and decreased significantly above that concentration. In addition, the dose-dependent effect of estrogen on the growth and differentiation of each cell type in the presence and absence of IP was also tested. At the concentrations of IP which showed maximum effects in the induction of ALP, 10(-10) M for ROB cells and 10(-7) M for HPLF, IP inhibited DNA increase in an estrogen-independent manner. Estradiol (10(-11)-10(-9) M) itself increased the growth rate of both cell types significantly in a dose-dependent manner. Regardless of the concentrations of estradiol tested, ALP activities of both ROB cells and HPLF were elevated by the addition of IP. The ratio of ALP in the presence and absence of IP was similar over the range of estradiol concentrations tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1992

Effect of phorbol myristate acetate on release of arachidonic acid and its metabolites in the osteoblastic MOB 3-4 cell line and its subclone, MOB 3-4-F2.

We examined the effect of phorbol 12-myristate 13-acetate (PMA) on release of arachidonic acid (AA) and its metabolites in osteoblastic cells in an attempt to study mechanism of the regulation of phospholipase A2 (PLA2) activity. In the MOB 3-4-F2 cell line, a subclone of the clonal osteoblastic MOB 3-4 cell line, PMA (0.1-100 nM) changed its appearance and increased AA release in a dose- and time-dependent manner, whereas 4 alpha-phorbol 12,13-didecanoate (4 alpha-PDD) did not show a significant affect on the release. The addition of 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA, greater than or equal to 1.5 mM), a Ca2+ chelator, almost completely inhibited the PMA-induced AA release without affecting the intrinsic AA release. Preincubation with staurosporine (5-20 nM), an inhibitor of protein kinase C (PKC), partially (approximately 60%) blocked the AA release. However, 30-min preincubation with H-7 (50-200 microM), an inhibitor of PKC, failed to block the AA release. PMA, thus, appeared to stimulate AA release partially by a staurosporine-sensitive mechanism, probably an activation of PKC, in an external Ca(2+)-dependent manner. On the other hand, MOB 3-4 cells responded to PMA with an increased AA release but not with a drastic change of its shape. Both staurosporine and BAPTA exerted similar inhibitory effects. Prolonged exposure (48 h) to PMA (0.1-10 nM) enhanced DNA synthesis of MOB 3-4-F2 cells, but not MOB 3-4 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaloids↗
PubMed1992

Phorbol ester-like action of staurosporine on the cAMP response to prostaglandin E2 in two macrophage-like cell lines at distinct differentiation stages.

The purpose of this study is to investigate the involvement of protein kinase C (PKC) in prostaglandin E2 (PGE2)-stimulated cAMP production of two macrophage-like cell lines (G3 and XC). XC cells are thought to be placed at a more differentiated stage than G3 cells [Orikasa et al. (1991) Cell Immunol. 132, 350-365]. In RPMI 1640 containing 10% (v/v) heat-inactivated foetal calf serum (FCS), in which the cAMP response of both cells to PGE2 increased with duration of culture, XC cells showed greater response than G3 cells at 2 days of culture. In alpha-minimum essential medium (alpha-MEM) containing 20% (v/v) heat-inactivated horse serum (HS), the cAMP response of both cells was apparently greater than that in RPMI 1640 containing 10% (v/v) FCS. These cells increased cAMP production also in response to PGE1 and PGF2 alpha, and the order of potency in increase was PGE1 > PGE2 >> PGF2 alpha. Interestingly, a short-term (20 min) treatment with phorbol 12-myristate 13-acetate (PMA), a direct activator of PKC or staurosporine, a relatively specific inhibitor of PKC, augmented the PGE2-stimulated cAMP production in these cells cultured in alpha-MEM containing 20% (v/v) HS. However, a long-term (24 h) treatment with these compounds did not alter the cAMP response. In G3 cells, PMA appeared more potent than staurosporine in terms of augmentation, whereas in XC cells, the former appeared less potent than the latter.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaloids↗
PubMed1992

Calcium in osteoblast-enriched bone cells.

The exchangeability, location, and amount of the total calcium in bone cells were studied in relation to their osteoblastic activity. Cells were isolated from neonatal rat calvariae by sequential collagenase digestion and incubated with 45Ca2+ before or after various treatments. 45Ca2+, 40Ca2+, and DNA were determined on each cell sample. Long-term experiments were performed on cultured cells. The cells closest to the forming bone had the highest alkaline phosphatase activity and the highest Ca2+ content (i.e., 17 mm Ca2+/l cell water, as compared to soft tissue cells, which have 2-3 mm Ca2+/l (Borle 1981). About 50% of this Ca2+ exchanges readily with 45Ca2+ and appears to be located almost entirely in the cell membrane. Thirty-five percent exchanges only slowly with a t1/2 of 27 hours, and is located within the cell, principally in the mitochondria as seen in pyroantimonate fixed cells (Neuman et al. 1985). In spite of its slow exchange-ability, this Ca2+ fraction can be mobilized or augmented rapidly when Ca2+ supply is reduced or increased in vitro or in vivo. 1,25(OH)2D3 given in vivo increased this intracellular Ca2+ when the Ca2+ supply was low and released it when the Ca2+ supply was high. About 15% of the Ca2+ in these cells was nonexchangeable. These results suggest that osteoblasts do process more Ca2+ when closer to the mineralization site. Whether this Ca2+ is en route from blood to bone or from bone to blood will require further study.

Alkaline Phosphatase↗
PubMed1992

Reversibility of energy metabolism and intracellular pH after cerebral ischaemia evaluated by 31P-MRS.

We have previously developed a reproducible model of transient forebrain ischaemia in rats by bilateral carotid artery occlusion combined with temporary increase of ICP. With this model, reversibility of the energy metabolism and intracellular pH (pHi) was investigated by 31P-MRS during 120 min of recirculation in three groups of, respectively, 30, 60, and 120 min of ischaemia. With the induction of ischaemia, ATP and phosphocreatine (PCr) disappeared, and measurement of pHi showed severe acidosis in all rats. In the 30 min ischaemia group, both energy metabolism and pHi recovered almost completely. In the 60 min ischaemia group, ATP recovered to 74% of control values, but pHi showed full recovery. In the 120 min ischaemia group, ATP recovered to about 50% of control values, and recovery of pHi was variable. Showing logarithmical changes during recirculation in ATP and PCr, the rate of metabolic recovery was fast during 60 min of recirculation, but it decreased and reached plateau thereafter in all groups. Recovery of pHi was affected by ATP levels, and was precipitously accelerated as ATP levels exceeded 50% of pre-ischaemic values. These results suggest that prolongation of the duration of ischaemia limits the restoration of the energy state, and the quality of pHi recovery after cerebral ischaemia is affected by the degree of ATP recovery during 60 min of recirculation.

Adenosine Triphosphate↗
PubMed1992

Endothelin increases myofilament Ca2+ sensitivity in alpha-toxin-permeabilized rabbit mesenteric artery.

This study was designed to investigate the mechanism of endothelin-1 (ET-1) contractions in Staphylococcus alpha-toxin-permeabilized vascular smooth muscle. Rabbit small mesenteric arteries permeabilized with alpha-toxin were mounted for isometric or isotonic force recording or were processed for determination of myosin light chain (MLC) phosphorylation levels. Addition of 100 nM ET-1 plus 10 microM GTP significantly enhanced myofilament Ca2+ sensitivity as compared with the addition of Ca2+ alone (EC50, 0.47 microM Ca2+ for Ca2+ alone and 0.13 microM Ca2+ for ET-1 plus (GTP). This enhanced sensitivity was reversed by GDP beta S. ET-1-induced contractions were relaxed at a constant [Ca2+] by the addition of 30 microM cAMP or cGMP, demonstrating a direct effect of the cyclic nucleotides on contractile regulation. Inhibition of protein kinase C activity by 100 nM staurosporine relaxed ET-1 plus GTP-induced contractions, and pretreatment with 40 microM chelerythrine inhibited the ET-1 plus GTP increase in force. At 0.32 microM Ca2+, steady-state levels of shortening velocity were not increased by ET-1 plus GTP, although steady-state levels of MLC phosphorylation were significantly enhanced. The ET-1-induced increase in MLC phosphorylation was not altered by changes in [Ca2+], whereas the shortening velocity was Ca2+ dependent, suggesting that the increase MLC phosphorylation level may be the result of protein kinase C, rather than MLC kinase, activation. These results are consistent with the hypothesis that ET-1 increases myofilament Ca2+ sensitivity by a G protein-dependent pathway and subsequent activation of protein kinase C.(ABSTRACT TRUNCATED AT 250 WORDS)

Actin Cytoskeleton↗
PubMed1992

[Influence of affect on everyday memory: self-reference of retrieval cue].

There have been two views as to mood congruent recall: The one interprets it as an automatic process, while the other explains that it appears only when self-referent information processing is running. In this study, one experiment was conducted in order to examine these two opposing views. By false feedback of task performance, positive or negative mood had been induced in each subject, who was given two "cue" words, and asked to retrieve everyday events. The result was that mood congruent recall occurred when the word "self" was presented as a cue; but no effect of mood with neutral cues. This result supports the hypothesis that mood congruent recall is found only when self-referent information is processed. However, such effect was not evident in positive mood condition. In positive mood condition, there remains a possibility that mood congruent recall may be an automatic process. The effects of mood on memory were discussed from various viewpoints.

Adult↗
PubMed1992

[A case of Turner's syndrome associated with moyamoya disease].

A case of Turner's syndrome associated with Moyamoya disease in a 10-year-old female is presented. This patient had experienced two periods of syncope and transient right hemiparesis in 2 years. She was short in stature. She had cubitus vargus and mental retardation. The serum LH and FSH values were high. By chromosomal examination Turner's syndrome (karyotype: 45, X/46, X, i(Xq)) was diagnosed. An MRI (SE 2000/20) revealed abnormal vessels on the basal ganglia. Cerebral angiography showed occlusion of bilateral internal carotid arteries at the distal portion, bilateral posterior cerebral arteries at the proximal portion. Basal moyamoya well developed. EDAS (encephalo-duro-arterio-synangiosis) was performed bilaterally. We consider that this may be the first case report of Turner's syndrome associated with Moyamoya disease, and that there may be no relationship between Turner's syndrome and Moyamoya disease in this case.

Cerebral Angiography↗
PubMed1992

[Natural history for residual intracranial AVM: compared with that for conservatively treated AVM].

It is generally accepted that the most suitable treatment of AVM is surgical removal which does not cause neurological deficits. But in some cases, it is impossible to treat surgically because of size or location, so the patient is unfortunately discharged with some part of the nidus remaining. In this paper, we report the natural history of residual AVMs in which part of the nidus remained after initial therapy, and try to ascertain whether therapeutic reduction of the nidus is more effective in preventing intracranial hemorrhage than conservative treatment. Of 362 cases, residual AVMs were found in 35 cases, and were followed up for 9.2 years on average. Eighty cases treated with only conservative therapy were also followed up for 10.9 years on average. The annual risk of intracranial hemorrhage for residual AVMs was 2.9% and that for conservatively treated AVMs was 3.0%, not a significant difference. There was no difference between the two groups in mortality or ADL. We conclude that therapeutic reduction of the nidus was not effective in preventing intracranial hemorrhage.

Adolescent↗
PubMed1992

[Traumatic intracranial aneurysms after removal of tuberculum sellae meningioma: case report].

Two cases of traumatic aneurysms (TA) of the internal carotid artery (IC) due to removal of tuberculum sellae meningioma (TSM) are presented, and ideal treatment of those aneurysms is discussed. The tumor, compressing the IC laterally, was removed out without arterial injury in case 1. Though the patient's postoperative course was uneventful, frontal and intraventricular hemorrhage developed 2 months after the operation, and an IC dorsal aneurysm was detected. Preoperative angiograms showed no aneurysm, so it was considered to be a traumatic aneurysm due to the surgical procedure. The aneurysm was clipped at once, but postoperative angiograms showed recurrence of the aneurysm. IC balloon occlusion was carried out as the Matas test was negative. In case 2, a small tear in the IC was inadvertently made during recurrent TSM removal, which was wrapped with muscle using fibrin glue. 2 weeks after the operation, frontal hemorrhage developed. Angiograms revealed a small aneurysm of the IC, which was considered to be a traumatic aneurysm. IC balloon occlusion was performed as the Matas test was negative. These 2 patients have had no episodes of rerupture after the IC balloon occlusion. Tumors and main arteries are frequently adhesive, so arteries are easily injured during removal of meningiomas. Muscle wrapping was not enough to prevent TA formation. Neck clipping was not appropriate for treatment of TA, but IC balloon occlusion was an effective and excellent therapy for TA of IC.

Adult↗
PubMed1992

[Radiosensitive malignant meningioma presenting Garcin's syndrome: a case report].

A 58-year-old woman with Garcin's syndrome caused by malignant meningioma is reported. She first noticed left facial hypesthesia followed by left visual disturbance with exophthalmos. CT scan showed an enhanced mass extending from the left cavernous sinus to the left orbit. Cranial x-ray revealed bone deformity around the orbit. The tumor was subtotally resected and its histological type was shown to be anaplastic meningioma. After the initial surgery the patient was left with hyposmia, mild ptosis and incomplete 6th cranial nerve palsy on the left side. After one and half years, not only palsy of those cranial nerves but also that of other unilateral cranial nerves became progressively apparent due to tumor regrowth. In total, 11 nerves (2nd-12th) were affected by the tumor, without long tract signs or symptoms of increased intracranial pressure. Radiation therapy carried out after the 2nd surgery was extremely effective and resulted in the recovery of lower cranial nerve function. The tumor was founded to have disappeared completely on the 2-year follow-up CT.

Combined Modality Therapy↗
PubMed1991

Effects of prostaglandin E2 and F2 alpha on cytoplasmic pH in a clonal osteoblast-like cell line, MOB 3-4.

Prostaglandin E2 (PGE2, 5 ng/ml to 5 micrograms/ml) induced a dose-dependent increase in cAMP accumulation, inositol phosphates (IPs) accumulation, and cytoplasmic free Ca2+ ([Ca2+]i) in a clonal osteoblast-like cell line, MOB 3-4. In contrast, prostaglandin F2 alpha (PGF2 alpha, 5 ng/ml to 5 micrograms/ml) stimulated increases in IPs accumulation and [Ca2+]i without stimulating an increase in cAMP accumulation. Both PGE2 (greater than 0.5 micrograms/ml) and PGF2 alpha (greater than or equal to 5 micrograms/ml) increased cytoplasmic pH (pHi) from approximately 7.15 to 7.35 in BCECF-loaded cells. A tumor promotor, phorbol 12-myristate 13-acetate (PMA, 0.1-100 nM) also increased pHi without effect on phosphoinositide hydrolysis. Both PGE2-(5 micrograms/ml) and PMA- (100 nM) induced cytoplasmic alkalinization was inhibited by removal of extracellular Na+, or by pretreatment of the cells with amiloride (0.5 mM), an inhibitor of Na+/H+ exchange, or H-7 (100 microM), a nonspecific inhibitor of protein kinase C. Thus, MOB 3-4 cells appeared to possess PGE2 receptors and PGF2 alpha receptors: the former are coupled to adenylate cyclase and phospholipase C, and the latter are predominantly coupled to phospholipase C. Also the cells appeared to possess an amiloride-sensitive Na+/H+ exchange activity, which increases pHi in response to PGE2 and PGF2 alpha, as well as to PMA. Long-term (48 hr) exposure of the cells to PGE2 at a high concentration (5 micrograms/ml), but not to PGF2 alpha and PMA, decreased DNA synthesis in the serum-deficient medium. Thus, cytoplasmic alkalinization appeared insufficient for cell replication. At least in MOB 3-4 cells, the inhibitory effect of PGE2 on DNA synthesis may be due to the cAMP messenger system.

Animals↗
PubMed1991

A case of malignant lymphoma in the liver treated by percutaneous ethanol injection therapy under peritoneoscopic observation.

A 41-year-old woman with non-Hodgkin's lymphoma in the liver was treated with percutaneous ethanol injection therapy. Ethanol injection was performed twice under ultrasonographic guidance for a lesion inside the liver and once under peritoneoscopic observation for lesions on the surface of the liver. CT performed after treatment showed that sizes of the lesions decreased and that the lesions were not enhanced by contrast medium, indicating lack of blood supply and necrosis of the lesion. Ultrasonography performed after treatment did not show any lesions in the liver. There was no sign of recurrence or metastasis.

Adult↗
PubMed1991

Establishment of murine macrophage-like mutant and hybrid cell lines: comparative analysis of the differentiation induced by 1 alpha,25-dihydroxyvitamin D3 and recombinant murine interferon-gamma.

The purpose of this study is to establish the monocyte/macrophage-like cell lines which are sensitive to potent systemic and local factors, 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2 VD3) and interferon-gamma (IFN-gamma). We established two variant mouse macrophage-like cell lines, whose responses to 1 alpha,25(OH)2 VD3 and IFN-gamma differed from one another. The AH-sensitive mutant cell line (G3) was induced by allowing P388D1 tolerant to 8-azaguanine. G3 mutant cells were then fused with the 1 alpha,25(OH)2 VD3-stimulated bone marrow cells isolated from DBA/2 mice. After AH selection the hybrid cell line (XC) was established. The G3 mutant cell line and the XC hybrid cell line had macrophage-like characteristics, such as surface antigens, Fc receptor, C3 receptor, and lysosomal enzymes. The treatment of G3 mutant cells with 1 alpha,25(OH)2 VD3 inhibited cell proliferation with morphological changes, and increased acid phosphatase activity, phagocytic activity, and F4/80 antigen expression on the cell surface. In contrast, IFN-gamma inhibited cell proliferation without effect on acid phosphatase activity and phagocytic activity but increased F4/80 antigen expression. In XC hybrid cells, on the other hand, IFN-gamma, but not 1 alpha,25(OH)2 VD3, inhibited cell proliferation with morphological changes but increased phagocytic activity and F4/80 antigen expression. In addition, IFN-gamma, but not 1 alpha,25(OH)2 VD3, dose-dependently increased multinucleated cell formation of both cells. These findings suggest that the G3 mutant cell line with macrophage-like characteristics is 1 alpha,25(OH)2 VD3- and IFN-gamma-sensitive, and that the XC hybrid cell line is, despite its macrophage-like characteristics, only IFN-gamma-sensitive. Therefore, these newly established cell lines will provide useful systems in studying the differentiation of monocyte/macrophage lineage.

Acid Phosphatase↗
PubMed1991

Starvation of a clonal osteoblast-like cell line, MOB 3-4-F2, down-regulates prostaglandin E2 receptors but increases cAMP response to prostaglandin E2.

Prostaglandin E2 (PGE2) stimulated cAMP production in the MOB 3-4-F2 cell line, a subclone of the osteoblast-like MOB 3-4 cell line. After being cultured in alpha-minimum essential medium supplemented with 10% heat-inactivated foetal calf serum (HIFCS), cells responded to PGE2 (greater than or equal to 50 ng/ml) with a small, but significant, increase in cAMP production. This response did not vary with duration of culture. In 2% HIFCS-containing medium, despite their lower basal cAMP level, cells responded to PGE2 (greater than or equal to 5 ng/ml) with strikingly increased cAMP production. In addition, prolonged culture in this serum-deficient medium enhanced this response. On the other hand, culture of cells in 2% HIFCS-containing medium decreased the apparent number of PGE2 receptors, which was also enhanced by prolonged culture, without effect on their apparent affinity. Their number in 10% HIFCS-containing medium, more than that in 2% HIFCS-containing medium, was almost constant, independent of the culture period. Starvation of MOB 3-4-F2 cells in serum-deficient medium, therefore, appeared to down-regulate PGE2 receptors but increase the cAMP response to PGE2. Moreover, prolonged starvation of cells appeared to facilitate these phenomena. Our findings suggest that cAMP response to PGE2 does not always reflect the number of available PGE2 receptors in the cells.

Animals↗