Search PubMed⌕ Search

Biomedical subjects

Makoto Watanabe

Publications and source records attributed to Makoto Watanabe.

At least 37 records · Page 2Linked to original sources
PubMed2006

Rapid and efficient MALDI-TOF MS peak detection of 2-nitrobenzenesulfenyl-labeled peptides using the combination of HPLC and an automatic spotting apparatus.

In this paper, we report MALDI-TOF ms analysis of 2-nitrobenzenesulfenyl (NBS) labeled peptides with the powerful aid of an LC-automatic spotting system. using this approach we analyzed mammalian sera (rat and mouse) as biological samples to demonstrate performance. The labeling was carried out using a binary set of 2-nitrobenzenesulfenyl chloride (heavy and light), which modified tryptophan residues in sample proteins. Approximately 1600 doublet peaks were detected in the mass spectrum, some of which had more than threefold differences in their intensities. systematic separation/spotting followed by mass analysis of the NBS-labeled peptides derived from biological samples is described for the first time. This method has proved to be an effective application of NBS-labeled peptides and can be a powerful technique for quantitative analysis of proteins expressed in biological systems.

Animals↗
PubMed2005

Evidence for phosphorylation of rat liver glucose-regulated protein 58, GRP58/ERp57/ER-60, induced by fasting and leptin.

Glucose-regulated protein 58 (GRP58)-like immunoreactivity in rat liver obtained in the evening or after fasting underwent an electrophoretic band-shift, which disappeared after phosphatase-treatment. Since mass spectrometric analysis raised a possibility that Ser150 of GRP58 is phosphorylated, an antibody against the phosphoserine150 GRP58 was generated. Immunoreactivity to this antibody was increased in the evening and after fasting. Since GRP58 was shown to interact with signal transducer and activator of transduction 3 (STAT3), a leptin-related protein, the effect of leptin was examined. Immunoreactivity to the anti-phosphoGRP58 antibody was markedly elevated after the leptin injection, indicating that Ser150 of GRP58 is phosphorylated after fasting and leptin-treatment.

Animals↗
PubMed2005

Congener profiles of PCDDs, PCDFs, and dioxin-like PCBs in the breast milk samples in Tokyo, Japan.

Exposure to dioxins has raised much public concern recently. We determined the congeners' distribution of polychlorinated-dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the breast milk samples collected in Tokyo, Japan. Breast milk was taken from 240 mothers, 30 days after delivery in 1999 and 2000 in Tokyo, Japan. The actual concentration and TEQ concentration of PCDDs (14 congeners), PCDFs (15 congeners), and dl-PCBs (12 congeners), and each congener's contribution to the total TEQ level were calculated. Among all the samples, PCDDs accounted for 34.8%, PCDFs accounted for 23.5%, dl-PCBs accounted for 41.7%, which was also similar in the breast milk from the primiparae and secundiparae. The main contributors to the total TEQ with increasing percentages were 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD and 3,3',4,4',5-PCB (#126), and they accounted for more than 65% of the total TEQ. Detailed congener analysis in breast milk samples is effective to understand dioxin sources.

Benzofurans↗
PubMed2005

Outer shape changes of human masseter with contraction by ultrasound morphometry.

OBJECTIVE: The multipennate masseter has a complex internal architecture, which suggests the contraction is not uniform within the muscle. The heterogeneous contraction may cause inequable changes of the muscle's outer shape. This study aimed to elucidate the outer shape changes of the whole masseter with clenching by multipoint measurement of serial ultrasound images. DESIGN: Serial coronal images (perpendicular to the FH plane, 3 mm interval) of the right masseter of five healthy men were obtained with a real-time ultrasonograph equipped with a 13 MHz linear-array transducer. To define the relationship between the transducer and cranium, we used a 3D mechanical stage with a face-bow. Registrations were made during muscle relaxation and maximal clenching. The distance between the lateral and medial outlines of the muscle was measured at intervals of 1mm from the origin to insertion in each image as the thickness at the corresponding measured point. RESULTS: The thickness of the relaxed and contracted muscle (R and C) and its difference (Delta) varied among the measured points. Muscle thickness at most measured sites increased with clenching, whereas it decreased at several sites, mainly near the origin and insertion. There were positive correlations in every subject both between R and C, and between C and Delta. On the other hand, the correlation between R and Delta were negative or weak. CONCLUSION: Changes of thickness with clenching showed great disparity within the masseter, which may result from the complexity of the contraction properties due to the multipennate structure and functional heterogeneity.

Adult↗
PubMed2005

Relationship of PCDD/F and Co-PCB concentrations in breast milk with infant birthweights in Tokyo, Japan.

OBJECTIVE: To observe how PCDD/F and Co-PCB concentrations in breast milk relate to infant birthweights in Tokyo, Japan. STUDY DESIGN: Breast milk samples were collected from 240 mothers (aged 25-34years old) residing in Tokyo to measure the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs; 14 congeners), polychlorinated dibenzofurans (PCDFs; 15 congeners), and coplanar polychlorinated biphenyls (Co-PCBs; 12 congeners) in the breast milk fat. Individual milk samples (about 50ml) were obtained 30days after delivery, between the months of June and September in 1999 and 2000. The relationship of the infant birthweights with the PCDD/F and Co-PCB concentrations was observed. RESULTS: The birthweights were negatively correlated the concentrations of many of the PCDD/F and Co-PCB congeners, with the mean toxic equivalent quantities (TEQs) of the Co-PCBs, and with the sum of the PCDD, PCDF and Co-PCBs, although their correlation coefficients were less than 0.200. Multiple regression analysis showed octachlorodioxin was statistically significant explanatory variate. CONCLUSIONS: There were slight relationship between the dioxins levels of breast milk and the birthweights of the infants.

Adult↗
PubMed2005

Distribution of ghrelin-immunoreactive cells in human gastric mucosa: comparison with that of parietal cells.

BACKGROUND: Ghrelin is a novel 28-amino-acid peptide isolated from rat and human stomach. This peptide is an endogenous ligand for the growth hormone secretagogue receptor and stimulates the release of growth hormones. Although the principal site of ghrelin synthesis has been reported to be in the stomach, there have been no reports of detailed descriptions of the distribution of ghrelin-immunoreactive cells in the stomach. We examined the distribution of ghrelin-immunoreactive cells in human gastric mucosa. METHODS: We studied the tumor-free mucosa along the lesser curvature in 30 patients with gastric cancer. Sections were stained with hematoxylin and eosin and then subjected to ghrelin immunohistochemistry. The distribution of ghrelin-immunoreactive and parietal cells was studied by continuous cell counting in restricted fields along the lamina muscularis mucosa. RESULTS: Ghrelin-immunoreactive cells were found in all regions, but were distributed mainly in the fundic region. The distribution of ghrelin-immunoreactive cells was positively correlated with that of parietal cells. CONCLUSIONS: The results of this study suggested that the distribution of ghrelin-immunoreactive cells follows that of parietal cells.

Antibodies↗
PubMed2005

A novel approach for N-glycosylation studies using detergent extracted microsomes.

Recently, it has become apparent that asparagine-linked (N-linked) oligosaccharide at an early stage of processing can play an important role in quality control of the secretory pathway. Here, we have developed a system for better understanding of the N-glycosylation machinery and its involvement in quality control in the endoplasmic reticulum (ER). Rough microsomes (RM) treated with 0.18% Tx-100 (TxRM) preserved translocation activities to a similar extent detected in RM. TxRM were depleted of many soluble proteins including glucosidase II, BiP and Erp72, but maintained approximately 80% of calnexin, a membrane protein. More importantly, TxRM revealed insufficient glycosylation of T cell receptor-alpha (TCR-alpha), suggesting that a factor or factors extracted with 0.18% Tx-100 is responsible for facilitating the transfer of oligosaccharides to the protein. In addition, the top band of TCR-alpha translated in TxRM migrated slower than that in RM, but faster than that in RM treated with castanospermine (CST), an inhibitor of glucosidase I/II. This suggests that the trimming of the inner two glucose sugars is impaired by the loss of glucosidase II. Furthermore, we demonstrated that TCR-alpha coprecipitated with calnexin migrated between unglucosylated and diglucosylated forms on SDS-PAGE. Thus, the treatment of RM with low concentration of detergent is a very powerful method for elucidating not only N-glycosylation processes but also other biological functions such as quality control in the ER.

Animals↗
PubMed2005

Effect of temporal resolution on the estimation of left ventricular function by cardiac MR imaging.

The aim of this study was to investigate the effect of temporal resolution on the estimation of left ventricular (LV) function by cardiac magnetic resonance (MR) imaging using a steady-state free precession (SSFP) sequence. Left ventricular function was assessed by cine MR imaging using a segmented SSFP sequence in 10 healthy volunteers. Views per segment (VPS) were set at 8 and 20, resulting in high and low true temporal resolution, respectively. Irrespective of VPS, images were reconstructed at 40 cardiac phases, providing high apparent temporal resolution. Data were analyzed using 40, 20 and 10 phases to simulate different apparent temporal resolutions. Increasing the cardiac phases used for analysis slightly decreased mean end-systolic volume (ESV) and slightly increased mean ejection fraction (EF). No substantial difference in estimates of end-diastolic volume (EDV) was found between VPSs of 8 and 20. Imaging with a VPS of 20 yielded a larger ESV and smaller EF than imaging with a VPS of 8 when 40 phases were used. In conclusion, low true temporal resolution causes overestimation of ESV and underestimation of EF. Improvement of apparent temporal resolution mildly reduces but does not eliminate the errors caused by low true temporal resolution.

Adult↗
PubMed2005

Water absorption characteristics of two types of acrylic resin obturators.

STATEMENT OF PROBLEM: The mechanisms of water accumulation in the inner space of a closed hollow obturator are not understood, and it is not known whether the porosity of acrylic resin is involved in these mechanisms. PURPOSE: The purpose of this study was to evaluate water absorption by solid and closed hollow obturators and to determine the mechanisms of water accumulation in the inner space of the closed hollow obturator. MATERIAL AND METHODS: Twenty solid and 20 closed hollow spherical specimens (30 mm in diameter) were fabricated from heat-polymerized acrylic resin (Acron Clear). Closed hollow specimens consisted of 2 hemispheres (30 mm in diameter, 1.5 mm in thickness) joined with autopolymerizing resin (Unifast II). Ten solid and 10 closed hollow specimens were immersed in distilled water at 37 degrees C, while the other specimens were stored in an atmosphere of 100% relative humidity at 37 degrees C. Each specimen was weighed every 24 hours for 180 days, and weight changes between each group were compared by 2-way ANOVA and the Tukey HSD test. Split-plot design ANOVA was used to compare the course of the weight change over 180 days (alpha=.05). RESULTS: The weight of the closed hollow specimens increased immediately and became saturated by day 30, with an increase of 1.44% from the initial weight. Water accumulation was not observed inside the closed hollow specimen during the 180-day storage period. The weight of solid specimens increased more slowly than that of closed hollow specimens; by day 180 the weight of the latter had increased by 1.16%. However, no significant difference in changes in mean mass of the same type of specimen was observed between the 2 storage conditions. CONCLUSION: These results suggest that water accumulation inside a closed hollow obturator is unrelated to the water absorption properties of the acrylic resin.

Absorption↗
PubMed2005

Changes in serum lipid concentrations in patients with chronic hepatitis C virus positive hepatitis responsive or non-responsive to interferon therapy.

BACKGROUND: Changes in serum lipid concentrations during the administration of interferon to patients with chronic hepatitis C virus (HCV) infection have not been fully investigated. The present study was designed to compare changes in serum lipid concentrations before, during and after interferon therapy in responders and non-responders to treatment. METHODS: In total, 101 patients with chronic HCV positive hepatitis were enrolled in this study. High dose interferon alpha was given on alternate days for 6 months. Six months after the end of treatment patients were assessed for the presence or absence of HCV RNA to determine the results of interferon treatment. The time courses of changes in serum lipid concentrations were measured in all patients. RESULTS: The total cholesterol level increased gradually during and after interferon therapy, and its pattern of change coincided with that of serum cholinesterase activity. Pretreatment serum cholesterol concentrations did not differ between responders and non-responders to interferon therapy. The serum triglyceride concentration, conversely, showed a sharp increase during interferon administration and returned to its basal level after the end of treatment. Responders to interferon therapy tended to have higher pretreatment triglyceride concentrations than did non-responders. CONCLUSIONS: We clarified that serum cholesterol and triglyceride levels showed different patterns of change during interferon therapy.

Adolescent↗
PubMed2005

Associations between dietary intake and breast milk dioxin levels in Tokyo, Japan.

BACKGROUND: The presence of dioxins in breast milk has gained much attention recently. However, in Japan the relationship between the consumption of different foods and the human breast milk dioxin concentrations is still unclear. METHODS: Breast milk was taken from 240 mothers residing in Tokyo, Japan to measure and analyze the concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and coplanar poly-chlorinated biphenyls contained in the fat. Individual milk samples were obtained from the mothers 30 days after delivery in 1999 and 2000. The data of the mothers' diets before pregnancy were collected by means of food frequency and amount estimation. Spearman correlation analysis and stepwise multiple linear regression were used to analyze the data. RESULTS: The concentrations of dioxins in breast milk were influenced mainly by the mother's age and history of breast-feeding. All the Spearman correlation coefficients were less than 0.20. Pork, roast ham, sausage, salt codfish and tempura had negative correlations with breast milk dioxins. CONCLUSIONS: History of breast-feeding and the mother's age should be considered and emphasized in this kind of analysis. The cause effect relationship between dietary intake and breast milk dioxin levels were still uncertain.

Adult↗
PubMed2005

Prominent expression and activity-dependent nuclear translocation of Ca2+/calmodulin-dependent protein kinase Idelta in hippocampal neurons.

Multifunctional Ca2+/calmodulin-dependent protein kinases (CaMKs) including CaMKI, II and IV, are thought to regulate a variety of neuronal functions. Unlike CaMKII, which is regulated by autophosphorylation, CaMKI as well as CaMKIV are activated by CaMKK. In this study, we examined the cellular and subcellular localization of CaMKIdelta, a recently identified fourth isoform of CaMKI, in the mature brain. In situ hybridization analysis demonstrated wide expression of CaMKIdelta mRNA in the adult mouse brain with prominent expression in the hippocampal pyramidal cells. FLAG-tagged CaMKIdelta was localized at the cytoplasm and neurites without nuclear immunoreactivity in approximately 80% of the transfected primary hippocampal neurons. The stimulation with either KCl depolarization or glutamate triggered the nuclear localization of FLAG-tagged CaMKIdelta by two-fold with a peak at 1 min. In contrast, the catalytically inactive mutants of CaMKIdelta remained cytoplasmic without nuclear translocation during KCl depolarization, indicating the requirement of its activation for the nuclear translocation. Furthermore, we showed that immunoprecipitated CaMKIdelta could phosphorylate cAMP response element binding protein (CREB)alphain vitro and that the over-expression of CaMKIdelta enhanced GAL4-CREB-luciferase activity in PC12 cells stimulated by KCl depolarization. Our present study provides the first evidence for the possible involvement of CaMKIdelta in nuclear functions through its nuclear translocation in response to stimuli that trigger intracellular Ca2+ influx.

Animals↗
PubMed2005

Mortality among persons with a history of Kawasaki disease in Japan: can paediatricians safely discontinue follow-up of children with a history of the disease but without cardiac sequelae?

AIM: To clarify the question of whether patients with Kawasaki disease suffer a higher mortality rate after the incidence of the disease in comparison with age-matched healthy individuals. METHODS: Between July 1982 and December 1992, 52 collaborating hospitals collected data on all patients having a new, definite diagnosis of Kawasaki disease. Patients were followed up until 31 December 2001 or their death. The expected number of deaths was calculated from Japanese vital statistics data and compared with the observed number. RESULTS: Of 6576 patients enrolled, 29 (20 males and 9 females) died. The standardized mortality ratio (SMR: the observed number of deaths divided by the expected number of deaths based on the vital statistics in Japan) was 1.15 (95% CI: 0.77-1.66). In spite of the high SMRs during the acute phase, the mortality rate was not high after the acute phase for the entire group of patients. Although the SMR after the acute phase was 0.75 for those without cardiac sequelae, six males (but none of the females) with cardiac sequelae died during this period; and the SMR for the male group with cardiac sequelae was 1.95 (95% CI: 0.71-4.25). The mortality from congenital anomalies of the circulatory system was elevated, but no increase in cancer deaths was observed. CONCLUSION: Although it was not statistically significant, the mortality rate among males with cardiac sequelae due to Kawasaki disease appeared to be higher than in the general population. On the other hand, the mortality rates for females with the sequelae and both males and females without sequelae were not elevated.

Child↗
PubMed2005

Colorectal cancer and serum C-reactive protein levels: a case-control study nested in the JACC Study.

BACKGROUND: Recently, it has been hypothesized that inflammation increases the risk of colorectal cancer. We investigated whether serum levels of C-reactive protein (CRP), a biomarker of inflammation, are associated with colorectal cancer, using serum samples collected in the Japan Collaborative Cohort Study (JACC Study). METHODS: We conducted a nested case-control study in the JACC Study, investigating the relationship between the risk for colorectal cancer and serum levels of CRP determined by a high-sensitivity CRP enzyme immunoassay. The subjects recruited were 141 patients with colorectal cancer (63 males and 78 females) and 327 controls with no history of cancer (148 males and 179 females). Each case of colorectal cancer was matched for sex, age and participating institution to 2 or 3 controls. We used ttest to analyze mean differences in CRP levels between colorectal cancer cases and controls. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated using a conditional logistic regression model after adjusting for the potential confounding factors. RESULTS: Serum CRP levels were not clearly associated with the risk of colorectal cancer. The OR of the highest serum CRP levels was 1.18 (95% CI: 0.68-2.06) for colorectal cancer and 1.42 (95% CI: 0.73-2.74) for colon cancer, compared to subjects with lowest serum levels. The OR for incidence of colorectal cancer showed a similar trend, but the difference was not significant. Thus, high serum CRP levels did not appear to increase the risk of colorectal cancer. CONCLUSIONS: The present results suggest that high serum CRP levels are not associated with the risk of colorectal cancer in the JACC Study.

Adult↗
PubMed2005

Evolution of interleukin-18 binding proteins and interleukin-1 receptor, type II proteins.

Interleukin-18 (IL-18) is one of the pivotal cytokines controlling the defense mechanism called inflammation. As a first step to develop proteins for controlling the IL-18 level, we initiated a study of IL-18-binding proteins (IL-18BPs). Twenty-four IL-18BP family members, 11 from vertebrates and 13 from chordopoxviruses, were picked from the NCBI database. Eight of these vertebrate IL-18BPs and two of the chordopoxvirus IL18-BPs were identified here and characterized as new members of the IL-18BP family. Their IL-18 binding domains were aligned and the distribution of highly conserved critical amino acid residues was analyzed and used to construct a phylogenetic tree. From this tree it was inferred that at least two independent events created two different ancestral viral IL-18BP genes by retroposition of IL-18BP genes from the vertebrate lineage. These two events are estimated to have occurred after an ancient mammalian IL-18BP gene diverged from birds, and before the mammalian IL-18BP gene diverged into human, ungulate and rodent IL-18BP genes. Moreover, our results suggest that IL-18BP and interleukin-1 receptor, type II (IL-1R2) had a common ancestral gene and diverged from the ancestral gene into IL-18BP and IL-1R2 genes in the fish period.

Amino Acid Sequence↗
PubMed2005

[In-vitro phantoms for estimating diffusion tensor tractography].

No literature has reported on in-vitro diffusion tensor tractography, although it is a useful method to visualize neuronal fiber projections in the living human brain. We applied this technique to phantoms of asparagus stems and bundled polyester yarn, and obtained tractography with high-quality images. On the asparagus stem phantom, straight tracts along the axis were displayed. On the polyester phantom, these tracts followed the course of the bundle whether it was straight or curved. These phantoms are useful for in-vitro evaluation of diffusion tensor tractography.

Algorithms↗
PubMed2004

Involvement of mitogen-activated protein kinases and protein kinase C in cadmium-induced prostaglandin E2 production in primary mouse osteoblastic cells.

We previously reported that cadmium (Cd) induced prostaglandin E2 (PGE2) biosynthesis through the activation of cytosolic phospholipase A2 (cPLA2) and induction of cyclooxygenase 2 (COX-2) in primary mouse osteoblastic cells. In the present study, we further investigated the mechanism of PGE2 production by Cd focusing on the main mitogen-activated protein kinase (MAPK) subfamilies that mediate prostaglandin synthesis, extracellular signal-regulated kinase (ERK1/2 MAPK), c-jun-amino-terminal kinase (JNK MAPK) and p38 MAPK, and protein kinase C (PKC) which is activated by Cd in several kinds of cells. Cd at 2 microM and above stimulated PGE2 production in osteoblastic cells and its production was inhibited by the kinase-specific inhibitors PD98059, SB203580, curcumin, and calphostin C. Calphostin C also inhibited the production of PGE2 by phorbol 12-myristate 13-acetate (PMA), which is a potent activator of PKC. PD98059 inhibited PGE2 production stimulated by PMA as well as Cd, indicating that activation of PKC by ERK1/2 MAPK was necessary for Cd-stimulated PGE2 production. Moreover, Cd stimulated the phosphorylation of these three MAPKs, and inhibition of the phosphorylation of ERK1/2 MAPK by calphostin C was also observed. On the other hand, Cd was found to phosphorylate cPLA2 and the phosphorylation was inhibited by PD98059, indicating that cPLA2 was activated by Cd through ERK1/2 MAPK and released arachidonic acid (AA), a substrate of COX-2, from membranous phospholipids. From these results, it was suggested that activation of each of the ERK1/2, p38, and JNK MAPK cascades in addition to that of PKC and cPLA2 played an important role in the Cd-stimulated biosynthesis of PGE2 in mouse osteoblastic cells.

Animals↗