PubMed Health⌕ Search

Biomedical subjects

M Wakabayashi

Publications and source records attributed to M Wakabayashi.

At least 19 recordsLinked to original sources
PubMed2006

CLOCK is involved in obesity-induced disordered fibrinolysis in ob/ob mice by regulating PAI-1 gene expression.

BACKGROUND: An increased level of obesity-induced plasma plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular disease. AIM: The present study investigates whether the circadian clock component CLOCK is involved in obesity-induced PAI-1 elevation. METHODS: We examined plasma PAI-1 and mRNA expression levels in tissues from leptin-deficient obese and diabetic ob/ob mice lacking functional CLOCK protein. RESULTS: Our results demonstrated that plasma PAI-1 levels were augmented in a circadian manner in accordance with the mRNA expression levels in ob/ob mice. Surprisingly, a Clock mutation normalized the plasma PAI-1 concentrations in accordance with the mRNA levels in the heart, lung and liver of ob/ob mice, but significantly increased PAI-1 mRNA levels in adipose tissue by inducing adipocyte hypertrophy in ob/ob mice. The Clock mutation also normalized tissue PAI-1 antigen levels in the liver but not in the adipose tissue of ob/ob mice. CONCLUSION: These observations suggest that CLOCK is involved in obesity-induced disordered fibrinolysis by regulating PAI-1 gene expression in a tissue-dependent manner. Furthermore, it appears that obesity-induced PAI-1 production in adipose tissue is not closely related to systemic PAI-1 increases in vivo.

Adipose Tissue↗
PubMed2002

Expression of endothelial cell-associated molecules in AML cells.

Recently, it has been clarified that interaction between hematopoietic cells and endothelial cells is important in normal hematopoiesis and leukemogenesis. In this study, we examined the relationship between AML cells and endothelial cells by analyzing the expression profile of angiogenic factors, angiopoietin-1 (Ang-1), Ang-2, Tie-2 (a receptor for angiopoietins) and vascular endothelial growth factor (VEGF). Our results demonstrated that CD7(+)AML expressed Ang-2 mRNA frequently and integrin-family adhesion molecules (CD11c and CD18) intensively, suggesting the close correlation with endothelial cells. On the other hand, in t(8;21) AML cells, expression of Ang-2 was infrequent and expression of integrin-family adhesion molecules (CD11b, CD11c and CD18) was weak, suggesting the sparse association with endothelial cells. As for CD7(+)AML cells, despite the frequent and intense expression of endothelial cell-associated molecules (such as Ang-2, CD11c and CD18), intensity of Tie-2 expression was quite low (P < 0.05). Ang-2 expressed in CD7(+)AML cells is not considered to act in an autocrine fashion, but to work on endothelial cells to "feed" leukemic cells. Although Ang-2 is recognized as a natural antagonist for Tie-2, our data presented here suggested the alternative role of Ang-2 in the relationship between endothelial cells and leukemia cells, at least in a subset of leukemia such as CD7(+)AML. These results were supported by the study using AML cell lines, KG-1 (CD7 negative) and its subline KG-1a (CD7 positive); KG-1 had mRNA expression profile of Ang-1(+)Ang-2(-)Tie-2(+), while KG-1a showed Ang-1(+)Ang-2(+)Tie-2(-). These difference in the expression profile of angiogenic factors between CD7(+)AML and t(8;21)AML may explain the characteristic morphological features of these leukemias (CD7(+)AML as blastic type and t(8;21)AML as differentiative type).

Acute Disease↗
PubMed2001

Induction of intestinal cytochrome P450 (CYP3A) by rifampicin in beagle dogs.

Both male and female beagle dogs (four dogs/sex) were orally treated with rifampicin (Rif) at the dose of 10 mg/kg/day for 7 days and an additional eight dogs (four dogs/sex) were used as a control. The inducible effect of Rif on intestinal cytochrome P450, especially CYP3A enzyme, was investigated by measuring microsomal testosterone 6beta-hydroxylation (6beta-OHT) activity, immunoblot and ELISA analysis. In male dogs, microsomal 6beta-OHT activity in the duodenum, upper, middle and lower part of the jejunum and the ileum of the control was 229, 204, 194, 129 and 57 pmol/min/mg protein, while the activity of the Rif-treated dogs significantly increased to 456, 486, 430, 192 and 138 pmol/min/mg protein, respectively. The activity of intestinal 6beta-OHT in the control and Rif-treated female dogs showed almost similar levels to those observed in the corresponding male dogs. The activity of intestinal 6beta-OHT in both control and Rif-treated dogs was specifically inhibited by anti-CYP3A12 antiserum. The apparent K(m) value for 6beta-OHT activity in all sections of the small intestine was comparable with that in the liver, and no significant changes were observed in between control and Rif-treated dogs. In both control and Rif-treated dogs, immunoblotting of intestinal microsomes with anti-CYP3A12 antiserum produced a band indistinguishable from that of purified CYP3A12 or of immunoreactive CYP3A12 in liver microsomes. A significant increase in intestinal CYP3A content by Rif treatment was quantitatively verified by the ELISA analysis and the magnitude of its increase correlated well with that of 6beta-OHT activity elevation. Furthermore, the results of immunohistochemistry using the anti-CYP3A12 antiserum indicated that CYP3A protein was specifically distributed in epithelial cells throughout the small intestine and appeared to be predominant at the apical side of villus cells. These results demonstrate that Rif induces not only hepatic CYP3A12 but also intestinal CYP3A in dogs.

Administration, Oral↗
PubMed2001

A single-channel method for evaluation of very magnitudes of Ca2+ ion fluxes through epsilon4/zeta1 N-methyl-D-aspartate receptor channels in bilayer lipid membranes.

A single-channel method for evaluating agonist selectivity in terms of the very number of Ca2+ ions passed through the epsilon4/zeta1 N-methyl-D-aspartate (NMDA) receptor ion channel in bilayer lipid membranes (BLMs) is described. The number of Ca2+ passed through the single-channel was obtained from single-channel recordings in a medium where the primary permeant ion is Ca2+. The recombinant epsilon4/zeta1 NMDA channel was partially purified from Chinese hamster ovary cells expressing the channel and incorporated in BLMs formed by the tip-dip method. It was found that the epsilon4/zeta1 channel in BLMs is permeable to Ca2+ and Na+, but the number of Ca2+ passed through the channel is much fewer than that of Na+. The integrated Ca2+ currents induced by three typical agonists NMDA, L-glutamate and L-CCG-IV were obtained at concentration of 50 microM, where the integrated currents for all the agonists reached their saturated values. The integrated Ca2+ currents obtained are (3.1+/-0.21) x 10(-13) C/s for NMDA, (4.6+/-0.31) x 10(-13) C/s for L-glutamate and (5.7+/-0.25) x 10(-13) C/s for L-CCG-IV, respectively, suggesting that the three kinds of agonists have different efficacies to induce permeation of Ca2+. The range of the agonist selectivity thus obtained is much narrower than that of binding affinities for the NMDA receptors from rat brain. The present method is able to detect Ca2+ permeation with a detection limit of approximately 10(5) Ca2+ ions/s.

Animals↗
PubMed2001

Synthesis of functional protein in liposome.

The liposome consisting of eggPC, cholesterol, and DSPE-PEG5000 with a molar ratio of 1.5:1:0.08 was used to entrap cell-free protein synthesis reaction mixture. The synthesis of a mutant green fluorescent protein in the liposome was confirmed by the fluorescence emitted from the liposome on flow cytometry analysis and fluorescence microscopy. The protein synthesized in the liposome is hence functional.

Journal Article↗
PubMed2001

Structure-activity relationship studies of (+/-)-terbutaline and (+/-)-fenoterol on beta3-adrenoceptors in the guinea pig gastric fundus.

(+/-)-Terbutaline and (+/-)-fenoterol are both arylethanolamine analogs that have tertbutyl and aryliso-propyl substituents respectively at the a position on the nitrogen of the ethanolamine side chain. In the present study, we have investigated the structure-activity relationships of (+/-)-terbutaline and (+/-)-fenoterol as beta3-adrenoceptor agonists in the guinea pig gastric fundus. (+/-)-Terbutaline and (+/-)-fenoterol induced concentration-dependent relaxation of the precontracted gastric fundus with pD2 values of 4.45+/-0.10 and 5.90+/-0.09, and intrinsic activities of 1.00+/-0.03 and 0.99+/-0.01 respectively. The combination of the selective beta1-adrenoceptor antagonist (+/-)-atenolol (100 microM), and the selective beta2-adrenoceptor antagonist (+/-)-butoxamine (100 microM), produced a 2 and 6 fold rightward shift of the concentration-response curves for (+/-)-terbutaline and (+/-)-fenoterol respectively, without depressing the maximal responses. The order of potency of these agonists was (pD2 value): (+/-)-fenoterol (5.09+/-0.10) > (+/-)-terbutaline (4.13+/-0.08). In the presence of (+/-)-atenolol and (+/-)-butoxamine, however, the non-selective beta1, beta2- and beta3-adrenoceptor antagonist (+/-)-bupranolol caused a concentration-dependent rightward shift of the concentration-response curves for (+/-)-terbutaline and (+/-)-fenoterol. Schild plot analyses of the effects of (+/-)-bupranolol against these agonists gave pA2 values of 6.21+/-0.07 ((+/-)-terbutaline) and 6.37+/-0.06 ((+/-)-fenoterol) respectively, and the slopes of the Schild plot were not significantly different from unity (p>0.05). These results suggest that the relaxant responses to (+/-)-terbutaline and (+/-)-fenoterol are mainly mediated through beta3-adrenoceptors in the guinea pig gastric fundus. The beta3-adrenoceptor agonist potencies of arylethanolamine analogs depend on the size of the end of the alkylamine side chain.

Adrenergic beta-Agonists↗
PubMed2001

Adenomatoid hyperplasia of the palate mimicking clinically as a salivary gland tumor.

This report describes an illustrative case of adenomatoid hyperplasia (AH) of the minor salivary glands on the palate of a 31-year-old man. The clinical features of the present lesion corresponded with those of pleomorphic adenoma, but histologically large lobules of normal-appearing mucous acini were found. The cell proliferative activity demonstrated in histological sections, by an immunohistochemical staining of proliferating cell nuclear antigen and Ki-67, showed no statistically significant differences among AH and a matched control group of normal palatal salivary glands. This case suggests that AH apparently exhibits an idiopathic, focal hypertrophic lesion of intraoral mucous glands with limited growth potential.

Adenoma, Pleomorphic↗
PubMed2001

[A case of radiologically negative small-cell lung carcinoma successfully detected early by whole-body FDG-PET].

A 68-year-old man was referred to our hospital after being treated for early gastric cancer to investigate the causative malignancy, as his serum carcinoembryonic antigen (CEA) level was increased. Chest radiography showed no abnormal opacities. Subsequently, a whole-body FDG-PET was performed, which detected some tiny lesions in the mediastinum and the right lower lung field. A diagnosis of small-cell lung carcinoma was made after mediastinoscopic and bronchoscopic examinations. After chemoradiotherapy, the previously abnormal uptake of FDG was attenuated and the bronchoscopic appearance was improved, while the serum CEA and NSE levels returned to normal. Our findings demonstrated that whole-body scanning by FDG-PET could be useful for early detection of lung cancer, especially in cases of small-cell lung cancer.

Aged↗
PubMed2001

Phylogenetic relationships and evolution in Chrysosplenium (Saxifragaceae) based on matK sequence data.

Chrysosplenium (Saxifragaceae) consists of 57 species widely distributed in temperate and arctic regions of the Northern Hemisphere, with two species restricted to the southern part of South America. Species relationships within the genus are highly problematic. The genus has traditionally been divided into two groups, sometimes recognized as sections (Oppositifolia and Alternifolia), based on leaf arrangement, or, alternatively, into 17 series. Based on morphological features, Hara suggested that the genus originated in South America and then subsequently migrated to the Northern Hemisphere. We conducted phylogenetic analyses of DNA sequences of the chloroplast gene matK for species of Chrysosplenium to elucidate relationships, test Hara's biogeographic hypothesis for the genus, and examine chromosomal and gynoecial diversification. These analyses revealed that both sections Oppositifolia and Alternifolia are monophyletic and form two large sister clades. Hence, leaf arrangement is a good indicator of relationships within this genus. Hara's series Pilosa and Macrostemon are each also monophyletic; however, series Oppositifolia, Alternifolia, and Nepalensia are clearly not monophyletic. MacClade reconstructions suggest that the genus arose in Eastern Asia, rather than in South America, with several independent migration events from Asia to the New World. In one well-defined subclade, species from eastern and western North America form a discrete clade, with Old World species as their sister group, suggesting that the eastern and western North American taxa diverged following migration to that continent. The South American species forms a clade with species from eastern Asia; this disjunction may be the result of ancient long-distance dispersal. Character mapping demonstrated that gynoecial diversification is dynamic, with reversals from inferior to half-inferior ovaries, as well as to ovaries that appear superior. Chromosomal evolution also appears to be labile with several independent origins of n = 12 (from an original number of n = 11) and multiple episodes of aneuploidy.

Journal Article↗
PubMed2000

Evaluation and comparison of ion permeation and agonist selectivities for N-methyl-d-aspartate receptor channels with different subunit compositions in bilayer lipid membranes based on integrated single-channel currents.

To quantify the ion-permeation ability of the recombinant epsilon1-4/zeta1 channel activated by agonists, the magnitude of agonist-induced integrated single-channel currents for the epsilon2-4/zeta1 N-methyl-d-aspartate (NMDA) channels in bilayer lipid membranes (BLMs) was evaluated electrochemically based on the single-channel recordings. The recombinant epsilon2-4/zeta1 channels were purified from Chinese hamster ovary cells expressing each channel and incorporated in BLMs formed by the tip-dip method. Three typical agonists, l-glutamate, NMDA, and (2S, 3R, 4S) isomer of 2-(carboxycyclopropyl)glycine (l-CCG-IV), were investigated at a concentration of 50 microM. The magnitude of l-glutamate-induced integrated current was found to depend on the epsilon-subunit composition and to increase in the order of epsilon2/zeta1 > epsilon1/zeta1 approximately epsilon4/zeta1 > epsilon3/zeta1, which differs from that of the reported binding affinities (EC(50)) between l-glutamate and each channel type. On the other hand, the magnitude of the integrated currents induced by NMDA and l-CCG-IV did not vary among the four channel types. The order of agonist selectivity toward the epsilon2-4/zeta1 channels in terms of the magnitude of the integrated current was l-glutamate > l-CCG-IV approximately NMDA for the epsilon2/zeta1 channel, l-CCG-IV > NMDA > l-glutamate for the epsilon3/zeta1 channel, and l-CCG-IV approximately l-glutamate > NMDA for the epsilon4/zeta1 channel, suggesting that the agonist selectivity also depends on the epsilon-subunit composition. The present study shows that each epsilon1-4/zeta1 channel has its own ability of ion permeation, i.e., its own signal transduction ability, which is not parallel to its binding ability.

Animals↗
PubMed2000

Screening of organophosphate insecticide pollution in water by using Daphnia magna.

A simple and rapid screening method using Daphnia magna Straus (water fleas) on the basis of their immobilization was developed for detecting pesticide pollution. The laboratory testing of the toxicity of 11 organophosphate insecticides to D. magna determined 50% inhibition concentration of mobility at 48 h of exposure (48-h EC50) of 0.19 to 2.6 microg/L. The mobility of D. magna was inhibited in several river and stream waters sampled from May 1995 to February 1998 in Tokyo. Chemical analysis of the waters revealed that they were polluted by sub-ppb or ppb level of organophosphate insecticides. A significant relationship was observed between the immobilization of D. magna and the pollution level of the river and stream waters. The D. magna test could be used as a low-cost preliminary screening method for insecticide pollution.

Animals↗
PubMed2000

Papillary serous carcinoma of the peritoneum: analysis of clonality of peritoneal tumors.

Papillary serous carcinoma of the peritoneum (PSCP) is a primary neoplasm of peritoneal origin, and is histologically difficult to differentiate from papillary serous carcinoma of the ovary (PSCO). PSCP is frequently accompanied by many peritoneal tumors, and has been managed as a disseminated disease. In previous reports, however, the clonality of the tumors has not been fully discussed. Recently, the significant roles of the p53 and BRCA1 genes in PSCP have been reported. In this study, we investigated immunohistochemical staining for p53 proteins, and investigated p53 gene mutations, using DNA sequencing analysis, to clarify the clonality of PSCP tumors. Immunohistochemically, all the tumor samples demonstrated nuclear overexpression of p53 proteins, and the DNA sequencing analysis of the p53 gene showed diverse point mutations at codons 167 and 192 in two of four anatomically different tumors. In conclusion, the possibility of polyclonality of PSCP tumors is suggested.

Aged↗
PubMed2000

Effect of certain chemicals on the reproduction of medaka (Oryzias latipes).

In order to understand the effects of estrogenic chemicals on fish reproduction, we exposed male medaka (Oryzias latipes) to a natural estrogen [17 beta-estradiol (17 beta-E2)] and three estrogenic chemicals [bisphenol-A, nonylphenol (NP) and di(2-ethylhexyl)phthalate (DEHP)]. After two weeks' exposure, one male medaka was kept together with two female medaka for spawning, and the number of eggs and hatchings were compared to those of a negative control group. The results indicated that exposure to 17 beta-E2 caused a significant decrease in the number of eggs and hatchings as compared to the negative control group at and above 3 nmol/l. Also, the highest concentrations of bisphenol-A and NP caused a decrease in the number of hatchings, but no decrease in hatchings was observed in DEHP treatments. In the treatment using these chemicals the decrease in egg numbers was not so much as in hatching numbers. When compared to other in vitro studies, concentrations observed to have adverse effects on reproduction in this study are generally lower. In addition, it was suggested that physical alterations, such as an induction of plasma vitellogenin, were caused at much lower concentrations than those at which a decline in reproductivity was actually induced.

Animals↗
PubMed2000

A phase I dose escalation study of multicyclic, dose-intensive chemotherapy with peripheral blood stem cell support for small cell lung cancer.

A phase I dose-escalation study of multicyclic, ifosfamide, carboplatin, and etoposide (ICE) with sequential reinfusion of peripheral blood stem cells (PBSCs) was conducted to determine the maximum-tolerated dose (MTD) of ICE. Twenty-four patients with SCLC (LD: 6, ED: 18) were treated with ifosfamide (3000-9000 mg/m2, 24-h infusion), carboplatin (300-400 mg/m2), and etoposide (300 mg/m2) followed by subcutaneous filgrastim (75 microg/day) from day 4 to the day of PBSC collection. PBSC were harvested when the WBC count reached >/=5 x 109/l. The leukapheresis product was cryopreserved and reinfused on day 4 of the next cycle, which was started 48 h after the last PBSC collection. The ifosfamide dose was escalated as follows: 3000 mg/m2 (level 1), 5000 mg/m2 (level 2), 7000 mg/m2 (level 3), 9000 mg/m2 (level 4). Patients with LD were treated with concurrent radiotherapy at 1.5 Gy twice daily for the initial 3 weeks to a total dose of 45 Gy and MTD, defined separately. Patients were evaluated for hematologic and non-hematologic toxicity, actual dose intensities, as well as response to therapy. The maximum-tolerated dose (MTD) was defined as the dose level at which more than 5 days of grade 4 myelo- suppression or non-hematologic toxicity greater than grade 3 developed in two thirds of the patients. For ED cases, MTD was level 4 and the recommended dose of ifosfamide was 7000 mg/m2. For LD cases, the recommended dose of ifosfamide was 5000 mg/m2. The dose limiting toxicity of multicyclic ICE was hemato- logic toxicity and CNS toxicity which manifested as ataxia. Tumor responses were seen in all patients, with 14 patients showing a complete response. The actual total dose-intensity at the recommended dose level was 2.2 and 1.74, for ED and LD, respectively, compared with previously reported ICE regimens. PBSC support for dose-intensive ICE regimen permitted dose escalation of ifosfamide with a mean interval of 16-17 days. We conclude that this regimen is well tolerated, with acceptable hematological and non-hematological toxicity. Bone Marrow Transplantation (2000) 25, 5-11.

Adult↗
PubMed2000

Effects of alcohol consumption on histological changes in chronic hepatitis C: a clinicopathological study.

BACKGROUND: To assess the effects of alcohol on the histological changes in chronic hepatitis type C, we performed histopathological examination on liver biopsy specimens by using a semiquantitative method. METHODS: Subjects were 91 patients with chronic hepatitis type C and 32 with alcoholic liver disease. The patients with chronic hepatitis type C were classified into three groups according to the total amount of alcohol intake: nondrinkers, moderate drinkers, and heavy drinkers. For each patient, we evaluated pathological changes of several items and awarded scores from 0 to 2 points, with severe to moderate scoring 2 points, mild 1, and negative 0; the total score was then compared between groups. The evaluated histological changes included virus-related histological changes (V1, inflammatory cell infiltration; V2, lymphoid follicle formation; and V3, bile duct damage) and alcohol-related changes (A1, perivenular fibrosis; A2, stellate/pericellular fibrosis; and A3, fatty change). RESULTS: The total scores of the hepatitis C virus-related histological changes were significantly lower in patients with alcoholic liver disease (ALD group) (p < 0.05). However, we found no significant difference between the different alcohol intake groups. The total score for alcohol-related histological changes significantly increased in line with increases in total alcoholic intake regardless of the presence or absence of hepatitis type C virus infection (p < 0.05). CONCLUSIONS: The results suggest that both alcoholic-related liver damage and virus-related liver damage have specific features; in a addition, alcohol was found to have little effect on the histological liver damage observed in chronic hepatitis type C.

Adult↗
PubMed2000

[Neurally mediated syncope in association with small cell lung carcinoma].

A 66-year-old woman was admitted to our hospital because of frequent syncopal episodes and for treatment of small cell lung carcinoma. Neurally mediated syncope was diagnosed by the head-up tilt test, which evoked early severe hypotension (after 12 min at the 80-degree tilt position). Treatment of carcinoma by chemotherapy and radiotherapy promptly eliminated the syncopal episodes. This was an unusual case of neurally mediated syncope associated with small cell lung carcinoma.

Aged↗