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Biomedical subjects

K Kawashima

Publications and source records attributed to K Kawashima.

At least 91 records · Page 5Linked to original sources
PubMed1999

Nerve growth factor increases the synthesis and release of acetylcholine and the expression of vesicular acetylcholine transporter in primary cultured rat embryonic septal cells.

Acetylcholine (ACh) is synthesized by choline acetyltransferase (ChAT) in the cytoplasm of cholinergic nerve terminals and transported into synaptic vesicles by vesicular ACh transporter (VAChT). The genes encoding ChAT and VAChT are colocalized within the genome, and their products are known to be coregulated by various neurotrophic factors. In the present study, nerve growth factor (NGF; 100 ng/ml) was shown to enhance expression of VAChT and ChAT mRNA in primary cultured rat embryonic septal cells. By using a radioimmunoassay, we also found that NGF increased both neuronal content and spontaneous release of ACh, which were first detected on day 2 of culture and time-dependently increased up to day 10. Stimulated release of ACh elicited by high K+ (50 mM KCl) was also significantly greater in NGF-treated cells than in control cells. NGF enhanced immunoreactivity to antiserum against VAChT, indicating that the augmented responses were due to, at least in part, increased expression of VAChT protein. In contrast, the numbers of immunocytochemically positive cells were unaffected. Thus, NGF appears to augment ACh synthesis, its transport into synaptic vesicles, and its subsequent release. The data also suggest that NGF facilitates growth and development of cholinergic neurons, but not their survival.

Acetylcholine↗
PubMed1999

Adverse effects of diphenyltin dichloride on initiation and maintenance of pregnancy in rats.

The objective of this study was to characterize the adverse effects of diphenyltin dichloride (DPTCl) during early pregnancy. Following successful mating, female rats were given DPTCl by gastric intubation at 0, 4.1, 8.3, 16.5, 24.8 or 33.0 mg/kg on days 0-3 or days 4-7 of pregnancy. Female rats were sacrificed on day 20 of pregnancy and pregnancy outcome was determined. The pregnancy rate was significantly decreased after administration of DPTCl on days 0-3 at 24.8 mg/kg and on days 4-7 at 33.0 mg/kg. The incidence of preimplantation loss was significantly increased after administration on days 0-3 at 16.5 mg/kg and above and on days 4-7 at 33.0 mg/kg. In females having implantations, the numbers of implantations and live fetuses and the incidences of pre- and postimplantation loss in the groups given DPTCl on days 0-3 were comparable to the controls. The incidence of postimplantation loss was significantly increased after administration of DPTCl on days 4-7 at 33.0 mg/kg. A pair-feeding study revealed no evidence of pre- and postimplantation embryolethality induced by food restriction. It could be concluded that DPTCl during early pregnancy causes early embryonic loss and DPTCl has greater effects on reproduction when administered during earlier than later stages of blastogenesis.

Animals↗
PubMed1999

Diversity of mRNA expression for muscarinic acetylcholine receptor subtypes and neuronal nicotinic acetylcholine receptor subunits in human mononuclear leukocytes and leukemic cell lines.

Previously, we reported that various levels of acetylcholine (ACh), currently known as a neurotransmitter, are detectable in the blood of several mammals including humans and that most blood ACh originates from T-lymphocytes. To investigate whether ACh in the blood acts on lymphocytes and participates in the modulation of immune responses, we have analyzed the expression of mRNA for muscarinic (Ms) ACh receptor subtypes and nicotinic (Nc) ACh receptor subunits using reverse transcription-polymerase chain reaction (RT-PCR) methods. The cells tested were human peripheral mononuclear leukocytes (MNLs) from seven healthy donors and eight leukemic cell lines, as models of lymphocytes. We detected mRNA expression for various neuronal Nc receptor subunits and Ms receptor subtypes in all of the MNL samples and in all of the cell lines tested. However, the expression pattern of mRNA for neuronal Nc receptor subunits (alpha2-alpha7 and beta2-beta4) and Ms receptor subtypes (m1-m5) varied among the individuals and cell lines. No expression of mRNA for three muscle-type Nc receptor subunits (alpha1, beta1 and epsilon) was observed in the MNLs and cell lines. These results indicate that both neuronal-type Nc and Ms ACh receptors are present on the surface of lymphocytes.

Adult↗
PubMed1999

Enhancement of cortical and hippocampal cholinergic neurotransmission through 5-HT1A receptor-mediated pathways by BAY x 3702 in freely moving rats.

Involvement of serotonin (5-HT) in the regulation of cholinergic neuronal activity by modulation of acetylcholine (ACh) release has been reported for various regions of the brain. Cortical and hippocampal cholinergic neurotransmission is of particular importance in the mechanisms of attention as well as learning and memory. In the present study, we investigated the effect of R-(-)-2-[4-[(chroman-2-yl-methyl)-amino-butyl]-1,1-dioxo-benzo[d]++ +isothiazolone hydrochloride (BAY x 3702), a novel, high-affinity 5-HT1A receptor agonist, on ACh release in the cerebral cortex and hippocampus of freely moving rats using an in vivo microdialysis technique. Acetylcholine efflux from the cortex and hippocampus was measured every 30 m using a sensitive and specific radioimmunoassay and was stable for at least 5 h. The ACh efflux from the cortex and hippocampus was increased significantly by BAY x 3702 (0.3 mg/kg, i.p.) compared with saline administration. WAY-100635 (0.6 mg/kg, s.c.), a selective 5-HT1A receptor antagonist, eliminated the augmentation of ACh efflux induced by BAY x 3702 in both brain regions. These results demonstrate that stimulation by BAY x 3702 enhanced ACh release in both the cortex and hippocampus through 5-HT1A receptor-mediated pathways.

Acetylcholine↗
PubMed1999

Constitutive expression of mRNA for the same choline acetyltransferase as that in the nervous system, an acetylcholine-synthesizing enzyme, in human leukemic T-cell lines.

Both muscarinic and nicotinic acetylcholine (ACh) receptors are known to be present on the surface of lymphocytes. We have shown that variable amounts of ACh are detectable in the blood of various mammals including humans, and a major portion of blood ACh is localized in circulating mononuclear leukocytes in humans. In order to investigate which types of blood cell are the source of ACh in human blood, expression of mRNA for choline acetyltransferase (ChAT, EC 2.3.1.6), which catalyzes ACh synthesis, was analyzed using human leukemic cell lines as models of lymphocytes and the reverse transcription-polymerase chain reaction (RT-PCR) method. We observed that mRNA for the same ChAT as that in the nervous system is expressed constitutively in all the T-cell lines tested, but not in B-, pre-lymphoma or monocytic cell lines. Furthermore, only T-cell lines showed high ACh-synthesizing activities and intracellular ACh contents. These results suggest that the major portion of ACh in the circulating blood originates from T-lymphocytes.

Acetylcholine↗
PubMed1999

Urodynamics in acetone-induced cystitis of anesthetized rats.

We examined the bladder function of cystitis models induced by intravesical acetone instillation in urethane-anesthetized rats. Acetone (0.35 ml) at 10, 30, or 50% concentration or deionized water (sham-treatment) was instilled into the bladder via the cannula which was inserted into the lumen. Acetone was withdrawn 90 sec after instillation and the bladder lumen was washed with saline after 15 min. One hour later, the cystometrogram induced by transvesical infusion of saline (3.3 ml/hr) was measured. During cystometrography of normal (non-treated) or sham-treated group, the time required to cause micturition, reflecting bladder capacity, was 9.6 +/- 0.9 (n = 7) or 10.0 +/- 0.8 min (n = 6), respectively. In the 10% acetone-treated group, the bladder capacity was similar to that in the normal or sham group. In the 30% acetone group, the time to micturition was 4.4 +/- 0.4 min (n = 7), indicating decreased bladder capacity, although the micturition pressure and the threshold pressure were not significantly different from those in the normal or sham group. However, in the 50% acetone group, the micturition reflex disappeared. In isolated rat bladder strips, contractile responses to carbachol or electrical field stimulation in the sham and 30% acetone group were similar. While, both responses in isolated strips from the 50% acetone group were reduced. The degree of damage from degeneration and desquamation of epithelium and hemorrhage in the bladder tissue from the 30% acetone group was less prominent than in the 50% acetone group. Additionally, some tissue from the 50% acetone group showed degeneration of muscle layer. The effects of three drugs were investigated in the 30% acetone group which showed increased urinary frequency. Baclofen (100 microg/kg, i.v.) and morphine (100 microg/kg, i.v.) increased significantly the bladder capacity and the threshold pressure. Atropine (10 microg/kg, i.v.) decreased the micturition pressure. These results suggest that cystitis models induced by intravesical instillation of 30% acetone may be valuable for evaluating drugs for the treatment of urinary frequency.

Acetone↗
PubMed1999

Some interactions of L-DOPA and its related compounds with glutamate receptors.

L-DOPA is probably a transmitter and/or modulator in the central nervous system (1). L-DOPA methyl ester (DOPA ME) is a competitive L-DOPA antagonist. However, it remains to be clarified whether there exist L-DOPAergic receptors. In Xenopus laevis oocytes injected with rat brain poly(A)+ RNA, L-DOPA induced small inward currents with ED50 of 2.2 mM at a holding potential of -70 mV. The currents were abolished by kynurenic acid or CNQX. Similar L-DOPA-currents were seen in oocytes co-injected with AMPA receptors, GluRs1,2,3 and 4. In brain membrane preparations, L-DOPA inhibited specific binding of [3H]-AMPA with IC50 of 260 microM. This inhibition was not modified by 200 microM ascorbic acid, an antioxidant. L-DOPA did not inhibit binding of [3H]-ligands of MK-801, kainate, DCKA and CGP39653. DOPA ME and L-DOPA cyclohexyl ester, a novel, potent and competitive antagonist (2), inhibited specific binding of [3H]-MK-801 with respective IC50 of 1 and 0.68 mM, but elicited no effect on that of the other [3H]-ligands. With low affinities, L-DOPA acts on AMPA receptors, while competitive antagonists act on NMDA ion channel domain. L-DOPAergic agonist and antagonist may not interact on ionotropic glutamate receptors. DOPA ME-sensitive L-DOPA recognition sites (1) seem to differ from glutamate receptors.

2-Amino-5-phosphonovalerate↗
PubMed1999

Histone deacetylase inhibitors are the potent inducer/enhancer of differentiation in acute myeloid leukemia: a new approach to anti-leukemia therapy.

We investigated the effect of the histone deacetylase inhibitors (HDIs), trichostatin A and trapoxin A on leukemia cells and cell lines from the viewpoint of differentiation induction. TSA induced differentiation in erythroid cell lines by itself, whereas it synergistically enhanced the differentiation that was directed by all-trans retinoic acid (ATRA) or vitamin D3 in U937, HL60 and NB4 cells. The combined treatment of HDI with ATRA induced differentiation in ATRA-resistant HL60 and NB4 cells. The transcriptional expression during the treatment with HDI was examined in HL60, U937 and MEG-O1. Cell cycle-regulator genes (p21waf1 and p16INK4A) were upregulated or constantly expressed, erythroid-specific genes (GATA-1, beta-globin) were silent or downregulated, and housekeeping genes (beta-actin and GAPDH) were constantly expressed. Twelve of 35 (34%) clinical samples from AML patients ranging from M0 to M7 also displayed both phenotypical and morphological changes by the treatment with TSA alone. HDIs are thus the potent inducer or enhancer of differentiation in acute myeloid leukemia and regulate transcription in an ordered manner.

3T3 Cells↗
PubMed1999

Antitumor activity of KF22678, a novel thioester derivative of leinamycin.

KF22678, a novel thioester derivative of leinamycin with the 1-oxo-1,2-dithiolane-3-one moiety, was examined for anti-tumor activity, toxicity in mice and activation mechanism. KF22678 showed a broad antitumor spectrum against human carcinoma xenografts (lung, colon, ovary and prostate). The efficacy of KF22678 was significantly higher than that of cisplatin. KF22678 exhibited low cross-resistance against various drug-resistant cell lines of MDR1 or MRP overexpressing human tumors, and, in addition, exhibited more potent antitumor activity in vivo than ADM against A2780/ADM and KB/MRP xenograft. DL-Buthionine sulfoximine (BSO) pretreatment significantly reduced intracellular glutathione (GSH) level in human lung carcinoma A549 cells, leading to decrease in the cytotoxicity of KF22678, whereas the cytotoxicity of melphalan was augmented by BSO pretreatment. DNA single-strand breaks (SSB) were observed in A549 cells treated with KF22678 and bleomycin. DNA SSB induced by KF22678 was greatly reduced in the presence of BSO in the cells, whereas DNA SSB induced by bleomycin was not. In addition, the antitumor activity of KF22678 against BSO-pretreated human lung carcinoma PC-9 tumor was significantly decreased. These results suggest that the activation of KF22678 by intracellular GSH might be important for DNA SSB and antitumor activity in vitro and in vivo.

Animals↗
PubMed1999

Posttreatment M-protein nadir level is a significant prognostic factor associated with survival in multiple myeloma. Nagoya Myeloma Cooperative Study Group.

In the present study 142 patients with myeloma (102 with IgG M-protein and 40 with IgA) treated with either VMCP (65 patients) or MMCP (77 patients) as remission induction therapy were retrospectively analyzed. Response to treatment was evaluated in terms of a more-than-50% fall of pretreatment M-protein and the posttreatment M-protein nadir. Though significantly more patients treated with MMCP achieved partial response (PR) as compared with those treated with VMCP (P=0.019) and though patients achieving PR showed a significantly longer survival than those with less responsiveness (P=0.0091), the difference in survival curves between the two treatment groups was not significant (P=0.1871). The difference in response between the treatment groups evaluated in terms of posttreatment nadir was not significant (P=0.507). Multivariate analysis identified posttreatment M-protein nadir as a significant prognostic factor associated with survival, along with 3 other factors: sex, performance status, and hemoglobin. The lack of difference between the survival curves for patients treated with the 2 regimens despite the significantly different response rates evaluated in terms of percent fall of pretreatment M-protein levels was considered to be due to the lack of a difference in the ability to induce a deep posttreatment nadir between the regimens. Posttreatment M-protein nadir is an important prognostic factor associated with survival and should be included in the evaluation of the efficacy of chemotherapy.

Aged↗
PubMed1999

Possible dynamic neurotransmitter metabolism surrounding the fetus.

Human amniotic epithelial cells express makers of glial and neural stem cells. These cells also synthesize and release acetylcholine and catecholamines. This study of amniotic fluid demonstrated that acetylcholine and catecholamines can be readily identified in the fluid. Norepinephrine was the major catecholamine present, although dopamine and DOPAC could also be detected. The physiologic role of these amniotic fluid neurotransmitters in fetal-placental interactions and nervous system development is currently under investigation.

Acetylcholine↗
PubMed1999

Enhancement of the serotonin-mediated acetylcholine release by repeated desmethylimipramine treatment in the hippocampus of freely moving rats.

A possible involvement of serotonin-mediated cholinergic activation in the antidepressant effect of desmethylimipramine (DMI) was investigated by determination of the effects of a single or repeated DMI administration on acetylcholine (ACh) release in the hippocampus using an in vivo microdialysis technique and a radioimmunoassay for ACh. Rats were administered DMI (10 mg/kg, i.p.) acutely or repeatedly for 21 days. A single or repeated DMI administration did not cause any significant effects on the basal ACh release compared with the respective controls. Atropine perfusion in the acutely DMI-treated or control rats increased the ACh release to the same degree. In repeatedly DMI-treated rats, serotonin (5-HT) (1 to 10 microM) perfusion enhanced significantly the ACh release. However, 5-HT in acutely DMI-treated rats enhanced significantly the ACh release only at 10 microM. 5-HT did not cause any changes in ACh release in control rats. Hippocampal 5-HT content of acutely DMI-treated rats was significantly higher than that of saline-treated control rats, while no difference was observed between the repeatedly DMI- and saline-treated rats. These findings suggest, for the first time, that DMI induced a facilitation of cholinergic neurotransmission in the rat hippocampus through the activation of 5-HT-receptor function.

Acetylcholine↗
PubMed1999

Detection of porcine circovirus from lesions of a pig with wasting disease in Japan.

A wasting disease characterized by progressive weight loss and dyspnea has been observed in weaning pigs on a farm in Yamagata Prefecture in 1998. Histopathologic findings in an affected pig were bronchointerstitial pneumonia and intracytoplasmic clusters of basophilic inclusions in macrophages of lymph nodes, which were similar to those in pigs with postweaning multisystemic wasting syndrome (PMWS) recently reported in North America and Europe. Porcine circovirus (PCV)-like particles were observed in bronchial lymph node of the pig by electron microscopy, and PCV antigens were detected in the lesions by immunohistochemical staining. PCV DNA was also detected in the lung and tonsil by PCR, and restriction fragment length polymorphism analysis of the PCR products with HinfI showed the same type of the PCV associated with PMWS (pmws PCV). Homology of nucleotide sequences between the PCR product and corresponding regions of published pmws PCV genomes was very high. These results indicated that virus detected in this study was pmws PCV. To our knowledge, this is the first report on the presence of pmws PCV in Japan.

Amino Acid Sequence↗
PubMed1999

[Analysis of elderly patients, aged 60 years old or over, with acute lymphoblastic leukemia].

In order to obtain the realistic background information on clinical features, and the present status of treatment and outcome in elderly patients with acute lymphoblastic leukemia (ALL), we carried out random survey of patients with ALL aged 60 or over who had been admitted to 13 general hospitals in the Nagoya region from January 1990 through December 1995. Among the 20 cases collected, ages ranged from 60 to 88 (median age 68), and the male to female ratio was 11:9. Nineteen cases were L2 subtype in FAB classification. Among 17 patients, 13 had B cell series surface phenotypes (76%), 2 had T cell series (12%), one had stem cell type (6%) and one had an undetermined phenotype (6%). Ph chromosomes were detected in 4 cases among 15 analyzed (27%), whereas 5 were found to have no chromosomal abnormality. Half of the patients had some concurrent disease at diagnosis, including two with treatment-limiting complications. Common induction regimens were the combination of adriamycin (ADM) + vincristine (VCR) + cyclophosphamide (CPM) + mitoxdn trone + L-asparaginase [4 patients]. ADM + VCR + PSL [4 patients]. VCR + PSL [4 patients] and others [8 patients]. The overall remission rate was 55.0% (11/20) without any significant difference according to age. The median survival time (MST) for all cases was 205 days. (1-year survival rate:17.9%, 2-year survival rate:10.8%). There was no significant difference in survival times among patients with the Ph chromosome, those with other chromosomal abnormalities and those without them. All the patients aged 75 or over were treated with attenuated induction therapy, and they had a shorter survival than those aged less than 75, but with no statistical significance [MST:121 days versus 276 days, p = 0.307 (generalized Wilcoxon test)].

Aged↗
PubMed1999

Aldehyde oxidase-dependent marked species difference in hepatic metabolism of the sedative-hypnotic, zaleplon, between monkeys and rats.

A marked difference in hepatic activity of aldehyde oxidase between rats and monkeys was found to be responsible for the previously reported marked species difference in the metabolism of Zaleplon in vivo. In the postmitochondrial fractions, S-9s, from liver homogenates of these animals, Zaleplon was transformed in the presence of NADPH into the side chain oxidation product, N-desethyl-Zaleplon, and the aromatic ring oxidation product, 5-oxo-Zaleplon. In the rat S-9, N-desethyl-Zaleplon and 5-oxo-Zaleplon were a major and a very minor metabolites, respectively. However, in the monkey S-9, Zaleplon was transformed into 5-oxo-Zaleplon at a much higher rate than that for N-desethyl-Zaleplon formation. N-Desethyl-Zaleplon was formed in the monkey S-9 at a rate almost equal to that in the rat S-9. N-Desethyl-5-oxo-Zaleplon was formed at a minor rate only in the monkey S-9 through N-desethyl-Zaleplon as an obligatory intermediate. The hepatic activity for the formation of 5-oxo-Zaleplon in the monkey and rat was localized in cytosol and did not require NADPH. Sensitivity to various inhibitors and requirement of water as oxygen source, using H218O, strongly suggested that the hepatic cytosolic formation of 5-oxo-Zaleplon was mediated by aldehyde oxidase. N-Desethyl-Zaleplon was formed in the presence of NADPH by microsomes from the liver of rats and monkeys, and its formation was strongly suggested using various cytochrome P-450 inhibitors to be mediated by a number of cytochrome P-450 isoforms, such as 3A, 2C, and 2D subfamilies.

Acetamides↗
PubMed1999

CD4- and CD56-positive T-cell line, MTA, established from natural killer-like T-cell leukemia/lymphoma.

We have established a T-cell line, MTA, from the peripheral blasts of a patient with natural killer (NK)-like T-cell leukemia/lymphoma. The MTA cell displays a T-cell and NK-cell phenotype (CD2+, CD3+, CD4+, CD56+) identical to freshly isolated leukemic blasts from the patient. This cell line shows clonal T-cell receptor rearrangement and a distinguishable character by light microscopy with May-Grünwald Giemsa staining. G-banding analysis showed that the MTA cells had a karyotype of 94(4N), XXXX, add (1) (p36), del (5) (q14q23), add (17) (p11), add (19) (q13). However, unlike NK malignancy, we could not show a direct pathogenic role for Epstein-Barr virus (EBV) with EBV-encoded small RNA and polymerase chain reaction analysis. The MTA cell line is a novel cell line with which to study NK-like T-cell ontogenecity.

CD4 Antigens↗