Biography:

In the past Shigeru Saito has collaborated on articles with Tamotsu Nakano and Michihiro Igarashi. One of their most recent publications is Determination of sodium and other impurities in alkoxysilanes by square-wave voltammetry. Which was published in journal Analytica Chimica Acta.

More information about Shigeru Saito research including statistics on their citations can be found on their Copernicus Academic profile page.

Shigeru Saito's Articles: (66)

Determination of sodium and other impurities in alkoxysilanes by square-wave voltammetry

AbstractThe determination of sodium concentration in acetonitrile and in acetonitrile-alkylalkoxysilane mixtures was investigated by using the static mercury drop electrode and square-wave voltammetry. Direct square-wave voltammetry was used over the range 10–100 μM Na+, and square-wave anodic stripping voltammetry was used in the range 1–10 μM Na+. The detection limit in the anodic stripping mode was found to be 0.3 μM. Further, the behavior of impurities in acetonitrile-alklalkoxysilane mixtures was investigated qualitatively.

Mouse dopamine β-hydroxylase: primary structure deduced from the cDNA sequence and exon/intron organization of the gene

AbstractGenomic clones for mouse dopamine β-hydroxylase (DBH) were isolated from two genomic libraries derived from DBA/2J and 129/SV mouse strains, by plaque hybridization with the human DBH cDNA probe. Subsequently, cDNA encoding mouse DBH was amplified with reverse transcription-polymerase chain reaction (RT-PCR) method using primers corresponding to 5′- and 3′-portions of the mouse DBH mRNA, subcloned into a plasmid vector, and subjected to nucleotide sequence analysis. The clone encoded a protein of 621 amino acids with a calculated molecular mass of 70, 186 daltons. The predicted amino acid sequence of mouse DBH showed 87%, 80% and 79% identities with the rat, bovine and human enzymes, respectively. Several potential amino acid sequences that are involved in the posttranslational modification and catalytic function of DBH were identified in mouse DBH protein. Nucleotide sequence analysis of the overlapping genomic clones showed that the mouse DBH gene was composed of 12 exons about 17 kb in length. Typical TATAand CCAAT boxes were observed in the 5′-upstream region of the gene. Northern blot analysis of adrenal gland RNA detected a single size species of the mouse DBH mRNA.

Determination of sodium and other impurities in alkoxysilanes by square-wave voltammetry

AbstractThe determination of sodium concentration in acetonitrile and in acetonitrile-alkylalkoxysilane mixtures was investigated by using the static mercury drop electrode and square-wave voltammetry. Direct square-wave voltammetry was used over the range 10–100 μM Na+, and square-wave anodic stripping voltammetry was used in the range 1–10 μM Na+. The detection limit in the anodic stripping mode was found to be 0.3 μM. Further, the behavior of impurities in acetonitrile-alklalkoxysilane mixtures was investigated qualitatively.

Determination of sodium and other impurities in alkoxysilanes by square-wave voltammetry

AbstractThe determination of sodium concentration in acetonitrile and in acetonitrile-alkylalkoxysilane mixtures was investigated by using the static mercury drop electrode and square-wave voltammetry. Direct square-wave voltammetry was used over the range 10–100 μM Na+, and square-wave anodic stripping voltammetry was used in the range 1–10 μM Na+. The detection limit in the anodic stripping mode was found to be 0.3 μM. Further, the behavior of impurities in acetonitrile-alklalkoxysilane mixtures was investigated qualitatively.

Determination of sodium and other impurities in alkoxysilanes by square-wave voltammetry

AbstractThe determination of sodium concentration in acetonitrile and in acetonitrile-alkylalkoxysilane mixtures was investigated by using the static mercury drop electrode and square-wave voltammetry. Direct square-wave voltammetry was used over the range 10–100 μM Na+, and square-wave anodic stripping voltammetry was used in the range 1–10 μM Na+. The detection limit in the anodic stripping mode was found to be 0.3 μM. Further, the behavior of impurities in acetonitrile-alklalkoxysilane mixtures was investigated qualitatively.

Determination of sodium and other impurities in alkoxysilanes by square-wave voltammetry

AbstractThe determination of sodium concentration in acetonitrile and in acetonitrile-alkylalkoxysilane mixtures was investigated by using the static mercury drop electrode and square-wave voltammetry. Direct square-wave voltammetry was used over the range 10–100 μM Na+, and square-wave anodic stripping voltammetry was used in the range 1–10 μM Na+. The detection limit in the anodic stripping mode was found to be 0.3 μM. Further, the behavior of impurities in acetonitrile-alklalkoxysilane mixtures was investigated qualitatively.

Mouse dopamine β-hydroxylase: primary structure deduced from the cDNA sequence and exon/intron organization of the gene

AbstractGenomic clones for mouse dopamine β-hydroxylase (DBH) were isolated from two genomic libraries derived from DBA/2J and 129/SV mouse strains, by plaque hybridization with the human DBH cDNA probe. Subsequently, cDNA encoding mouse DBH was amplified with reverse transcription-polymerase chain reaction (RT-PCR) method using primers corresponding to 5′- and 3′-portions of the mouse DBH mRNA, subcloned into a plasmid vector, and subjected to nucleotide sequence analysis. The clone encoded a protein of 621 amino acids with a calculated molecular mass of 70, 186 daltons. The predicted amino acid sequence of mouse DBH showed 87%, 80% and 79% identities with the rat, bovine and human enzymes, respectively. Several potential amino acid sequences that are involved in the posttranslational modification and catalytic function of DBH were identified in mouse DBH protein. Nucleotide sequence analysis of the overlapping genomic clones showed that the mouse DBH gene was composed of 12 exons about 17 kb in length. Typical TATAand CCAAT boxes were observed in the 5′-upstream region of the gene. Northern blot analysis of adrenal gland RNA detected a single size species of the mouse DBH mRNA.

The cerebral hemodynamic response to electrically induced seizures in man

AbstractThe hemodynamic response to seizure has long been a topic for discussion in association with the neuronal damage resulting from convulsion. Electroconvulsive therapy (ECT) is an appropriate clinical model for the investigation of the cerebral physiology of seizure. In this study, we monitored the oxygenation state of brain tissue using near infrared (NIR) spectrophotometry, and flow velocity at the middle cerebral artery (MCA) using transcranial Doppler ultrasonography (tc-Doppler) in ninety cases where ECT was prescribed to patients suffering from endogenous depression. Under general anesthesia with thiopental and succinyl choline, an electrical current was applied bilaterally at the minimal energy level. Throughout the therapy, end-tidal CO2 tension was maintained at 30–35 mmHg, and the SpO2 value was maintained above 98% by manual ventilation assistance. The total- and oxy-hemoglobin contents in the brain were reduced during the electrical shock, and then recovered to the pre-shock value (total-hemoglobin; 44.13 ± 12.88 s after the shock, oxy-hemoglobin; 88.62 ± 11.69 s after the shock). Subsequently, these values further increased beyond the preshock value. On the other hand, the deoxy-hemoglobin content increased for 90.73 ± 15.88 s during and after the electrical shock, and decreased afterward. Reduction of cytochrome aa3 began 3.04 ± 0.51 s after the electrical shock, and this was reoxygenated at 171.88 ± 12.95 s after the shock. The flow velocity at MCA was drastically increased (mean flow velocity; from 44.8 ± 1.2 cm/s to 106.4 ± 7.5 cm/s) 1 min after the shock and returned to the pre-shock level after 10 min. From these observations, it was suggested that electrical shock provoked a contraction of arterial wall smooth muscle, and depolarized the synaptic terminal, which triggered neurotransmitter release and sympathetic activation. This depolarization also caused an abrupt increase in the energy consumption of neurons and the cytochrome aa3 was temporarily reduced. However, this imbalance in energy supply and consumption was improved by the subsequent hyperdynamic blood circulation and by suppression of neuronal activity at the postictal phase. It was concluded that electrically induced seizure provokes a temporary imbalance in energy consumption and supply, and that these new non-invasive monitors are useful in the study of the physiological events that occur in the nervous system in man.

Trehalose in the body fluid of the silkworm, Bombyx mori L.

AbstractThe rate of metabolism of ‘blood sugar’ (trehalose) was studied using fifth instar larvae of the silkworm, Bombyx mori. Glycogen in the fat body decreased on starvation while body fluid trehalose remained approximately at the initial value during the first few hours of starvation. Experiments on the rate of turnover of body fluid trehalose were carried out by injecting radioactive sugars into the larvae. Values of 6 hr and 10·6 hr were obtained for the half-life of body fluid trehalose under feeding and starvation, respectively. When a large volume of saline was injected into starved larvae, the concentration of ‘blood sugar’ fell temporarily, and after a while it regained its initial level. On the other hand, when a large amount of trehalose was injected, the level of ‘blood sugar’ was elevated markedly followed by a fall to a value somewhat higher than the initial. These results suggest the existence of a homeostasis in blood sugar level. Mechanisms responsible for such a homeostasis are discussed.

IL-2 receptor expression and function on human cord blood mononuclear cells following PHA and anti-CD3 antibody stimulation

AbstractInterleukin-2 receptors (IL-2R) on mononuclear cells from human umbilical cord blood were investigated after stimulation by phytohemagglutinin (PHA) and anti-CD3 antibody. The proportion of cells expressing the Tac antigen (IL-2Rα, p55) did not differ from that for adult mononuclear cells. However, the levels of high affinity IL-2R (H-IL-2R) and low affinity IL-2R (L-IL-2R) present on the PHA blasts of cord blood cells were shown to be twice and three times, respectively, that of adults by interleukin-2 (IL-2) binding assay. The level of low affinity IL-2R in the cord blood cells was approximately double that of adult cells after activation by anti-CD3 antibody, but no difference was observed in the levels of high affinity IL-2R. Functional investigation of IL-2R revealed that the amount of internalized IL-2 in PHA-stimulated cord blood mononuclear cells was twice that in adult mononuclear cells but there were no differences between them in the time course of internalization and degradation.Although there were significant numbers of H-IL-2R in premature (25 and 28 weeks) infants following PHA stimulation, there were markedly fewer following anti-CD3 stimulation. Prematurity of the T-cell activation system through the CD3 pathway at this stage is therefore indicated.

Production of IL-6 (BSF-2/IFN β2) by mononuclear cells in premature and term infants

AbstractThe production of interleukin 6 (IL-6) was examined in premature neonates (48 cases, including 3 miscarried fetuses) and fullterm neonates (20 cases). The IL-6 production by mononuclear cells was measured after stimulation with Staphylococcus aureus Cowan Strain I (SAC), phytohemagglutinin (PHA) or lipopolysaccharide (LPS). The production in full-term neonates was similar to that in healthy adults, whereas it was significantly lower in premature neonates without premature rupture of the membrane (PROM). However, in premature infants with PROM a normal level of IL-6 production was observed in mononuclear cells stimulated with SAC, PHA and LPS. Furthermore, there was a positive correlation between the IgM concentration in the cord serum and IL-6 production by LPS-stimulated mononuclear cells.

Research reportCharacteristics of gangliosides including O-acetylated species in growth cone membranes at several developmental stages in rat forebrain

AbstractGrowth cones, the motile tips of extending neuronal processes, are involved in accurate synaptogenesis. To study the developmental changes in ganglioside composition including O-acetylated gangliosides in growth cones, we analyzed the gangliosides in growth cone membranes (GCM) prepared from rat forebrains at different developmental stages. At several stages, GCM contained significantly larger amounts of gangliosides than the other membrane subfractions. The ganglioside content of GCM increased in amount with development. Moreover, in GCM, the relative amount of GD3 gradually decreased, and that of GD1a dramatically increased. There were significant differences in the composition of ganglioside species between GCM and the perinuclear plasma membrane subfraction (NM); most importantly, GCM had a higher ratio of GD1a to GM3 plus GD3 than NM. There were three different O-acetylated gangliosides in GCM: O-acetyl-GD3, O-acetyl-GT1b, and O-acetyl-GQ1b. The molar ratio of O-acetyl-GD3 decreased in GCM at later stages (5% of the total gangliosides at embryonic day 17, to 1% at postnatal day 5). However, those of the other two O-acetylated gangliosides were almost constant (1–2% of the total). Our results show that there are significant differences in ganglioside content and composition between the membrane subfraction of growth cones and the perinuclear portion. This suggests that several species of gangliosides, including O-acetyl-GD3, play a role in growth cone function.

Clinical studyPrimary stent implantation without coumadin in acute myocardial infarction

AbstractObjectives. We tested the feasibility and efficacy of primary stent implantation without Coumadin in 74 patients within 8 h of the onset of acute myocardial infarction.Background. Although stent implantation in patients with effort angina provides better short- and long-term outcomes than balloon angioplasty, it is not clear whether primary stent implantation is applicable or effective in acute myocardial infarction.Methods. Primary stent implantation was attempted when 1) the lesion was not located distally in the main coronary branches, 2) the coronary artery did not show any severe calcification or excessive bending proximal to the lesion on fluoroscopy, and 3) the arterial diameter was ≥2.5 mm. The results (group S) were compared with those of primary balloon angioplasty (group P). Poststenting regimens contained ticlopidine and aspirin without Coumadin. Poststenting inflation was performed with ≥12 atm.Results. Stent implantation was successful in 72 patients. Stent thrombosis was noted in only one patient who was not given ticlopidine, aspirin or Coumadin. The rates of restenosis and frequency of major clinical events during the hospital period in groups S and P were 0% versus 13.2% (p = 0.007) and 2.8% versus 18.6% (p = 0.009), respectively. Kaplan-Meier analysis demonstrated that cumulative 90-day clinical event-free rates in groups P and S were 98.1 ± 16.0% versus 79.4 ± 43.7% (p = 0.0068), and that 180-day rates were 86.5 ± 38.4% versus 64.2 ± 49.7% (p = 0.014).Conclusions. Primary stent implantation can improve clinical outcomes of patients with acute myocardial infarction when the stent is dilated adequately and antiplatelet drugs are used.

Interleukin 1 beta and prostaglandin E are involved in the response of periodontal cells to mechanical stress in vivo and in vitro

Cytokines are local mediators released by cells of the immune system in response to stimulation by a variety of agents. These polypeptides may interact directly or indirectly with bone cells. The objectives of this study were (1) to localize prostaglandin E (PGE) and the cytokine interleukin-1β (IL-1β) in the periodontal ligament after the application of mechanical force to teeth in vivo and (2) to determine the effects of mechanical stress or IL-1β (or the two in combination) on PGE synthesis and bone resorption by fibroblasts in the human periodontal ligament (PDL). In 24 female cats, one maxillary canine was tipped distally by 80 gm force for 12 hours, 24 hours, or 7 days. PGE and IL-1β were localized immunohistochemically in serial jaw sections, and semiquantitation of cellular-staining intensity was done by microphotometry. Unstressed periodontal ligament cells stained mildly for PGE and IL-1β, but the staining intensity increased significantly in sites of tension. Human periodontal ligament fibroblasts were preincubated with mechanical stress and/or IL-1β in the presence or absence of indomethacin for 1 hour. Then the media were replaced by BGJb (Fitton-Jackson modification) medium (GIBCO), and incubation was continued for 4, 8, or 24 hours in conditioned media. PGE concentrations in conditioned media were determined by radioimmunoassay, and bone-resorbing activity in conditioned media was assessed by 45Ca release from prelabeled neonatal mouse calvaria. The conditioned media derived from cells stimulated by mechanical stress plus IL-1β caused significantly more bone resorption than the conditioned media obtained from cells that had been treated by each factor alone. The addition of indomethacin did not inhibit bone resorption completely. These results demonstrate that periodontal ligament cells respond to mechanical stress by increased production of PGE, and that IL-1β enhances this response.

Original contributionElevation of amniotic fluid interleukin 6 (IL-6), IL-8 and granulocyte colony stimulating factor (G-CSF) in term and preterm parturition

AbstractWe determined the levels of inflammatory cytokines such as interleukin 6 (IL-6) granulocyte-colony stimulating factor (G-CSF) and IL-8 in the amniotic fluids from women with premature or term delivery. Cytokines were detectable even in the absence of apparent infection (group 1), but much higher cytokine levels were found in cases of intrauterine infection, particularly in cases of premature delivery (group 2). In cases of term delivery (groups 3–5), all of the cytokine levels showed c. 3- to 4-fold increase during labor pain (group 4) and an 8- to 13- fold increase in the presence of endotoxin (group 5), in comparison with the levels in cases where neither factor was present (group 3). Regarding infection, the cytokine levels were 20- to 30- fold higher in chorioamnionitis-positive premature delivery group (group 2), than in the infection-negative group (group 1). All the cytokines were simultaneously induced in amniotic fluid by labor pain and infection, and a significant positive correlation was observed among these three cytokine levels. In-vitro culture system and immunohistochemical study indicated that the cytokines in the amniotic fluid appeared to originate from trophoblasts and decidual cells. Thus, infection and labor pain may trigger the production of inflammatory cytokines at term as well as premature delivery and the determination of these cytokine levels will be a good indication for the prediction of the presence of intrauterine infection.

Efficacy and Safety of Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Stents Versus Thin, Durable-Polymer Everolimus-Eluting Stents for Coronary Revascularization of Patients With Diabetes Mellitus

Patients with diabetes mellitus are prone to increased adverse outcomes after percutaneous coronary intervention, even with contemporary drug-eluting stents. Randomized controlled trials have demonstrated comparable clinical outcomes between an ultrathin bioresorbable-polymer sirolimus-eluting stent (BP-SES) and a thin-strut durable-polymer everolimus-eluting stent (DP-EES) that has specific labeling for patients with diabetes. We aimed to evaluate the safety and efficacy of the BP-SES in patients with diabetes mellitus. To determine the performance of the BP-SES in diabetic patients, patient-level data from the BIOFLOW II, IV, and V randomized controlled trials were pooled. The primary end point was target lesion failure (TLF), defined as the composite of cardiovascular death, target-vessel myocardial infarction, ischemia-driven target lesion revascularization, and definite or probable stent thrombosis, at 1 year. Among 1,553 BP-SES and 791 DP-EES patients, 757 diabetic patients were identified. Of the diabetic patients included in this analysis (494 BP-SES vs 263 DP-EES), the proportion of insulin- and noninsulin-treated patients was similar between groups. The 1-year TLF rate in the diabetic population was 6.3% in the BP-SES group and 8.7% in the DP-EES group (hazard ratio 0.82, 95% confidence interval 0.047 to 1.43, p = 0.493). There were no significant differences, based on stent type or diabetes treatment regimen, in TLF hazards. In a patient-level pooled analysis of the diabetic population from randomized trials, 1-year clinical safety and efficacy outcomes were similar in patients treated with ultrathin BP-SES and thin-strut DP-EES.

ResearchObstetricsOutcomes of infants exposed to oseltamivir or zanamivir in utero during pandemic (H1N1) 2009

ObjectiveTo assess adverse fetal outcomes and short-term prognoses of infants exposed to oseltamivir or zanamivir in utero during pandemic (H1N1) 2009 in Japan.Study DesignCase series study. We asked the 2611 obstetric facilities in Japan that are members of the Japan Society of Obstetrics and Gynecology to participate, and data were provided from 157 facilities. We evaluated the numbers of pregnancy complications and neonatal abnormalities.ResultsWe evaluated 624 infants born to 619 women given oseltamivir and 50 infants born to 50 women given zanamivir. Of patients given oseltamivir before gestational week 22, 3 experienced miscarriage and 1 experienced induced abortion. The overall rate of congenital malformations was 2.1% (14/670). In infants exposed during the first trimester, the rate of malformations was 1.3% (2/156) with oseltamivir and 0.0% (0/15) with zanamivir, although in infants exposed during the second and third trimesters, this rate was 2.6% (12/464) with oseltamivir and 0.0% (0/35) with zanamivir. Increased rates of miscarriage in women given antiviral drugs before gestational week 22 (0.9% [3/322]), preterm delivery in women given antiviral drugs before gestational week 37 (5.5% [33/600]), stillbirth (0% [0/670]), neonatal death (0.15% [1/670]), birthweight <2500 g (8.7% [58/670]), small-for-gestational-age infants (8.4% [56/670]), necrotizing enterocolitis (0.0%), intraventricular hemorrhage (0.0%), seizures (0.15% [1/670]), and other transient abnormalities in the neonatal period (4.3% [29/670]) were not observed in those exposed to antiviral drugs before the corresponding episodes or complications.ConclusionShort-term prognoses of infants exposed to oseltamivir or zanamivir in utero were not adversely affected.

Regular articleAnimal modelsTrophoblast-Specific Conditional Atg7 Knockout Mice Develop Gestational Hypertension

Hypertensive disorder of pregnancy (HDP) is a serious pregnancy complication that is life threatening to both the mother and fetus. Understanding HDP pathophysiology is important for developing medical treatments. This study demonstrates the involvement of autophagy deficiency in adverse maternal and fetal outcomes using trophoblast-specific autophagy related (Atg)7, an autophagy-related protein, knockout mice. Atg7 conditional knockout (cKO) placentas were significantly smaller than controls in the spongiotrophoblast layer but not the labyrinth layer, which significantly elevated blood pressure in dams. A marker of autophagy deficiency, sequestosome 1/p62, was accumulated in giant trophoblast cells and in the spongiotrophoblast layer, accompanying increased apoptosis. However, neither proteinuria in dams nor fetal growth restriction was observed. Regarding trophoblast function, the number of trophoblasts migrating into the maternal decidua was significantly reduced, and the wall/lumen ratio of the spiral arteries was significantly increased in cKO placentas, suggesting shallow trophoblast invasion and inadequate vascular remodeling. The relative expression of placental growth factor mRNA was significantly decreased in cKO placentas compared with the control, likely causing poor placentation; however, other factors were unchanged in cKO placentas. This is the first report of autophagy deficiency leading to impaired placentation complicated by maternal HDP attributable to trophoblast dysfunction, and it suggests that placental autophagy is required for normal placentation.

Pyridinoline fluorescence in cyanogen bromide peptides of collagen

SummaryPyridinoline is a fluorescent crosslinking amino acid of collagen fibers. But recently some investigators claimed that it is not a crosslink component but an artefact produced by the interaction of collagen and non-collagenous contaminants during acid hydrolysis. Their claim was based on the absence of pyridinoline in cyanogen bromide peptides of collagen. However, pyridinoline fluorescence was observed in cyanogen bromide peptides from both insoluble and pepsin solubilized collagen. By these results, pyridinoline is cleared of the suspicion that it is an artefact produced during acid hydrolysis.

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