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Biomedical subjects

H Satoh

Publications and source records attributed to H Satoh.

At least 73 records · Page 4Linked to original sources
PubMed2002

Minimally invasive direct coronary artery bypass for completely obstructed left anterior descending coronary artery.

BACKGROUND: We evaluated the efficacy of minimally invasive direct coronary artery bypass (MIDCAB) using the left internal thoracic artery (LITA) in patients with completely obstructed left anterior descending coronary artery (LAD). METHODS: Ten patients undergoing MIDCAB for LAD stenosis were enrolled in this study. These patients were all men aged 45 to 69 years, and were divided into two groups, one showing complete LAD obstruction (n=5, Group A), and one about 90% stenosis of the LAD (n=5, Group B). RESULTS: The internal size of the LAD at the anastomosis site was significantly smaller in Group A than in Group B, and the time required for graft anastomosis in Group A was significantly longer. Total operation time, intubation time after operation, perioperative bleeding, total blood transfusion, max CK-MB, and hospital stay did not significantly differ between the two groups. Postoperative coronary angiography revealed good graft patency in both groups, however, one Group A patient had graft obstruction. CONCLUSIONS: The MIDCAB procedure appears useful even in our patients with completely obstructed LAD, despite the long anastomosis time. However, the indications for this procedure are limited by any perceived difficulty in harvesting the LITA by indirect vision or in performing the anastomosis based on the size or quality of the LAD. Intensive preoperative angiography evaluation is essential and conversion to a median full-sternotomy is necessary for cases in which we cannot confirm the feasibility of MIDCAB.

Aged↗
PubMed2002

Thenar metastasis from lung cancer.

We report an unusual occurrence of skin metastasis to the thenar eminence. Skin metastasis reflects the progression of the primary malignancy. Biopsy should be performed from the skin lesions, even those located at uncommon sites, for patients who have a history of uncontrolled lung cancer.

Adenocarcinoma↗
PubMed2002

Measurement of microorganisms with PHA production capability in activated sludge and its implication in activated sludge model no. 3.

In Activated Sludge Model No.3 (ASM3), it is hypothesized that all heterotrophic microorganisms (X(H)) can store substrate. However, in reality, both microorganisms with and without substrate storage capability (X(H/STO) and X(H/S), respectively) could exist. If the ratio of X(H/STO) in activated sludge is influenced by operational and environmental conditions, kSTO (storage rate constant of heterotrophic microorganisms which is defined in ASM3) may not be a universal parameter and can change from case to case. In this study, polyhydroxyalkanoate (PHA) is assumed as the principal storage product, and the ratio of microorganisms with PHA production capability (X(H/PHA)) in various activated sludges was estimated by the dual staining of Nile Blue A (NB) and DAPI. It was shown that the ratio of X(H/PHA) in sludge varied among different municipal and laboratory activated sludges.

Environmental Monitoring↗
PubMed2002

PHA (polyhydroxyalkanoate) production potential of activated sludge treating wastewater.

The main purposes of wastewater treatment systems are to remove organic pollutants, but it would be very attractive if there were a way to recover the organic pollutants as valuable organic materials. One of the possible ways to recover organic pollutants in wastewater is to convert them into polyhydroxyalkanoates (PHAs), which are biodegradable plastics. In this study, 18 activated sludge samples in 4 wastewater treatment plants (WWTPs) in Tokyo, Japan, were evaluated for their potential to produce PHAs by aerobic batch experiments with excess supply of acetate as the sole carbon source. The activated sludge samples tested had the capability to accumulate PHA up to 18.8% of dry cell weight on average, with the range of 6.0% to 29.5%. The results showed that the maximum PHA content was dependent on the influent more than on the operational conditions of the activated sludge, and that conventional activated sludge produced PHA as much as anaerobic-aerobic activated sludge did. The PHA content achieved in this study is still low, and further improvement is needed to put into practice the recovery process of organic pollutants as biodegradable plastics by activated sludge.

Alkanes↗
PubMed2002

Analysis of microbial community that performs enhanced biological phosphorus removal in activated sludge fed with acetate.

Enhanced biological phosphorus removal (EBPR) activated sludge was operated in a laboratory-scale sequencing batch reactor (SBR) fed with acetate as the sole carbon source. The microbial community of the sludge was analyzed using the polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) method for about 2 months of start-up period. As a result, the number of major bands decreased during the enrichment, indicating that the microbial community structure was getting simpler. Since the phosphate removal activity was maintained at a high level, the bacteria which still remained at the end can be considered as the important bacteria playing key roles in the present EBPR sludge, maybe polyphosphate accumulating organisms (PAOs). The dominant band in the last sample on the DGGE gel was excised and the DNA recovered from it was sequenced. The sequence was closely related to one of the putative PAOs group which Crocetti et al. (2000) and Hesselmann et al. (1999) have proposed. This PAOs group is closely related to the Rhodocyclus group (b-Proteobacteria). The fluorescence in situ hybridization (FISH) method with the probe specific for this PAOs group and the DAPI staining at a phosphate-probing concentration indirectly showed that these Rhodocyclus related bacteria really accumulated polyphosphate.

Acetates↗
PubMed2002

Density separation and molecular methods to characterize enhanced biological phosphorus removal system populations.

A novel approach to the identification of microorganisms that accumulate high density microbial storage products based on density separation, denaturing gradient gel electrophoresis (DGGE), and DNA sequencing was developed and applied to bench and pilot scale enhanced biological phosphorus removal (EBPR) systems. Polyphosphate (PP), glycogen, and polyhydroxyalkanoates (PHAs), are all of higher density than a typical bacterial cell. PP-accumulating organisms (PAOs), the organisms responsible for EBPR, accumulate all three of these storage products. Density separation in a homogenous solution of Percoll produced a high-density biomass fraction with a relatively high concentration of PAOs, as determined by Neisser staining. DNA was extracted from these fractions, amplified, and separated by DGGE. DGGE profiles demonstrated some bacterial strains were present at a greater concentration in the high density fractions than in low density fractions. These strains were considered PAO candidates. 5 of 12 PAO candidates from high density fractions were gamma Proteobacteria and only 1 was a beta Proteobacterium. 2 PAO candidates were most similar to recently identified gamma Proteobacteria sequences obtained by DGGE analysis of a deteriorated benchtop EBPR system.

Biomass↗
PubMed2002

Structure and function of nitrifying biofilms as determined by molecular techniques and the use of microelectrodes.

The phylogenetic diversity of a nitrifying bacterial community of two types of nitrifying biofilms, a domestic wastewater biofilm and an autotrophic nitrifying biofilm grown on rotating disk reactors (RDR), was characterized by 16S ribosomal DNA (rDNA)-cloning analysis. Thereafter, successional development of nitrifying the bacterial community within both biofilms was visualized in situ by fluorescent in situ hybridization (FISH) wih a set of fluorescently labeled 16S rRNA-targeted DNA probes. In situ hybridization revealed that Nitrosomonas ureae was the numerically dominant species of the ammonia-oxidizing population in the domestic wastewater biofilm and that a population shift from N. urea to N. europaea and N. eutropha occurred when the culture medium was switched to the synthetic media from the domestic wastewater. After reaching the steady-state condition, microprofiles of NH4+, NO2-, NO3-, and O2 in the biofilms were measured by use of microsensors, and the spatial distributions of in situ nitrifying activities were determined. The relationship between the spatial organization of nitrifying bacterial populations and the in situ activity of these populations within the biofilms was discussed. Microelectrode measurements revealed that the active ammonia-oxidizing zone was vertically separated from the active nitrite-oxidizing zone. This vertical separation became more evident with increase of the substrate C/N ratio, leading to deterioration of nitrification efficiency. The combined use of these techniques made it possible to relate in situ nitrifying activity directly to the occurrence of nitrifying bacterial populations.

Ammonia↗
PubMed2002

Bacteriophage-host interaction in the enhanced biological phosphate removing activated sludge system.

Bacteriophages were isolated from a laboratory scale enhanced biological phosphate removing (EBPR) activated sludge process, and their host range was examined. Bacterial isolates to host the bacteriophages were isolated from the EBPR activated sludge process. Bacteriophages were eluted from the EBPR activated sludge, enriched by incubation with the bacterial isolates, and then tested for plaque formation on each of the bacterial isolates. Out of 12 bacterial isolates isolated, 4 supported plaque formation. Four bacteriophages were obtained from the plaques. The host range test was conducted with the combination of the bacteriophage isolates and the bacterial isolates. Three of the bacteriophages were found to form plaques on more than one host, and one of them formed plaques on both gram +ve and gram -ve bacterial isolates. Two of the four bacteriophages failed to form plaques on their original bacterial host, indicating the existence of mutation on either both or one of the host and the bacteriophage. This study strongly suggests that bacteriophages are an active part of the activated sludge microbial ecosystem, having very complex interaction with their host bacteria.

Bacteriophages↗
PubMed2002

Effect of important operational parameters on performance of coarse pore filtration activated sludge process.

A coarse pore filter can be applied inside the aeration tank instead of sedimentation tank for liquid separation from the sludge. It has pores, which are irregular in shape, and much bigger than micro-filtration membrane pores in size. The objective of the study was to investigate the effect of important operational parameters such as flux, aeration intensity, and solid retention time (SRT) on the performance of the coarse pore filtration activated sludge process. The effect of these parameters was studied in laboratory scale experiments. It was found that the flux had a significant role in the effluent quality of this system. The effluent SS and turbidity were not changed significantly at different aeration intensities. Three SRTs, 10, 30 and longer days (without excess sludge) were used for three reactors to check the effect of this parameter on the system performance. The results of the reactors with SRTs about 10 and 30 days have shown very good effluent quality without any filter clogging for more than 4 months operation. For the reactor with long SRT, the filter clogging was observed after about 80 days of operation, which caused the increase of the operation pressure and deterioration in the effluent quality for a few days.

Filtration↗
PubMed2002

Performance of coarse pore filtration activated sludge system.

A coarse pore filter can be applied inside the aeration tank to facilitate the separation of sludge from liquid instead of sedimentation. This filter has pores, which are irregular in shape, and the pore size is bigger than those of MF. The objectives of the study were to maintain as much as MLSS in the activated sludge process with coarse pore filter and to investigate the performance under high MLSS condition. Small-scale reactor results so far show good quality of effluent specially after starting the sludge bulking in the system in terms of SS, TOC, DOC and turbidity. The average carbon removal for 62 days operation of this system was about 94% (based on effluent DOC) and 87% (based on effluent TOC). The average sludge yield in this system is about 0.44 kg MLSS/kg TOC which is about 0.24 kg MLSS/kg BOD. This amount is less than those of conventional activated sludge and trickling filter.

Biomass↗
PubMed2001

Endothelin-1 gene variant associates with blood pressure in obese Japanese subjects: the Ohasama Study.

A recent report based on the results of 2 epidemiological studies, the Etude Cas-Temoin de l'Infarctus Myocarde (ECTIM) and the Glasgow Heart Scan Study, revealed that a G/T polymorphism with an amino acid substitution (Lys-->Asn) at codon 198 in exon 5 of the endothelin-1 gene (ET-1) is associated with blood pressure in overweight people. They suggested that G/T polymorphism of ET-1 strongly interacted with body mass index (BMI) in the determination of BP levels. To examine interaction among G/T polymorphism of ET-1, BMI, and BP, we performed an association study in a general Japanese population. Subjects (n=1250) were recruited from Ohasama, a cohort in a rural community of northern Japan. DNA was extracted from buffy coat of participants, and G/T polymorphism of ET-1 was determined by the TaqMan probe polymerase chain reaction method, a powerful tool for semiautomatic genotype determination of a large number of samples. Frequency of T (Asn 198) allele in Japanese (27%) was slightly but significantly higher than in whites (24%). Baseline characteristics (age, BMI, systolic and diastolic BP, and antihypertensive treatment) of all subjects were not significantly different according to the genotype of G/T polymorphism. However, in obese subjects (> or =25 kg/m(2)) diastolic BPs were significantly associated with G/T polymorphism of ET-1. After adjustment for confounding factors, significant association remained; for overweight subjects, diastolic BP level in those with T allele (GT + TT) was 1.8 mm Hg (P=0.04) higher than in those with GG genotype. That similar results were obtained from subjects of different races suggests that the Lys198Asn polymorphism of ET-1 is involved in determination of BP levels in obese subjects.

Asian People↗
PubMed2001

Exclusive association of paraoxonase 1 with high-density lipoprotein particles in apolipoprotein A-I deficiency.

Paraoxonase1 (PON1) is a high-density lipoprotein (HDL)-associated protein which removes peroxidized lipids from lipoproteins. It has been proposed that apolipoprotein A-I (apoA-I) is an important determinant for its stabilization on HDL. However, little is known about its existence and activity in an apoA-I-deficient state in humans. To characterize the nature of PON1 in apoA-I deficiency, we investigated PON1 in an apoA-I-deficient patient. When serum was analyzed on fast protein liquid chromatography, PON1 protein was distributed almost exclusively on HDL despite the absence of apoA-I; on the other hand, 38.5% of PON1 protein was found in the lipoprotein-free fraction when the lipoproteins were fractionated through ultracentrifugation. The stability of PON1 activity in the patient serum was almost the same as in the normal control sera throughout incubation at 14 degrees C for 7 days. However, when the sera were incubated at 37 degrees C for 24 h, its activity declined more than those in the normal controls (19% versus 4% reduction of the initial values). Our results demonstrated that PON1 protein possesses a preferential association with HDL even in the absence of apoA-I, although apoA-I is a crucial factor for the maximal activity and stabilization of PON1.

Aged↗
PubMed2001

Rna-binding protein Musashi2: developmentally regulated expression in neural precursor cells and subpopulations of neurons in mammalian CNS.

Musashi1 (Msi1) is a mammalian neural RNA-binding protein highly enriched in neural precursor cells that are capable of generating both neurons and glia during embryonic and postnatal CNS development. Here, we identified Musashi2 (Msi2), a novel mammalian RNA-binding protein that exhibits high sequence similarity to Msi1. The Msi2 transcript appeared to be distributed ubiquitously in a wide variety of tissues, consistent with the mRNA distribution of its Xenopus homolog, xrp1. However, the present study revealed cell type-specific and developmentally regulated expression of Msi2 in the mammalian CNS. Interestingly, Msi2 was expressed prominently in precursor cells in the ventricular zone and subventricular zone with the same pattern as Msi1 throughout CNS development. In the postnatal and adult CNS, this concurrent expression of Msi2 and Msi1 was seen in cells of the astrocyte lineage, including ependymal cells, a possible source for postnatal CNS stem cells. During neurogenesis, the expression of both Msi2 and Msi1 was lost in most postmitotic neurons, whereas Msi2 expression persisted in a subset of neuronal lineage cells, such as parvalbumin-containing GABA neurons in the neocortex and neurons in several nuclei of the basal ganglia. Msi2 may have a unique role that is required for the generation and/or maintenance of specific neuronal lineages. Furthermore, in vitro studies showed that Msi2 and Msi1 have similar RNA-binding specificity. These two RNA-binding proteins may exert common functions in neural precursor cells by regulating gene expression at the post-transcriptional level.

Alternative Splicing↗
PubMed2001

Intracellular chloride concentration is higher in rod bipolar cells than in cone bipolar cells of the mouse retina.

Bipolar cells (BCs) have antagonistic center-surround receptive field. Surround illumination evokes depolarization in the OFF-type cone BC, and hyperpolarization in the rod BC and the ON-type cone BC. Surround illumination reduces gamma-aminobutyric acid (GABA) release from horizontal cells. If GABA hyperpolarize BCs, the polarity of the GABA-induced effect agrees with the light-evoked surround response in the OFF-type BC, but contradicts in the rod BC and the ON-type cone BC. Immunohistochemical study of the Cl(-) transporter of BCs has suggested that the intracellular Cl(-) concentration is different among BC subtypes. We examined the reversal potential of GABA-induced current of BCs using gramicidin-perforated patch clamp technique in the mouse retina, and found that GABA depolarizes rod BC and hyperpolarizes cone BCs. Our results are consistent with the GABAergic input to rod BC dendrite.

Animals↗
PubMed2001

Identification of a novel human ankyrin-repeated protein homologous to CARP.

We cloned a novel ankyrin repeat protein, Arpp, by immunoscreening a cDNA library constructed from a human esophageal carcinoma cell line, TE1, with an antibody directed to a hypothetical protein encoded by antisense p53 mRNA. Arpp protein is composed of 333 amino acids and contains four ankyrin-like repeat motifs in the middle portion of the protein, a PEST-like sequence and a lysine-rich sequence similar to a nuclear localization signal in the N-terminal region, and a proline-rich region containing consensus phosphorylation sites in the C-terminal region. Protein sequence analysis revealed that Arpp is homologous (52.7% identity) to Carp which is shown to be involved in the regulation of the transcription of the cardiac ventricular myosin light chain 2 gene. Arpp mRNA was found to be expressed in normal skeletal and cardiac muscle. Interestingly, Arpp expression was detectable in bilateral ventricles, but undetectable in bilateral atria and large vessels, suggesting that Arpp may play a specific function in cardiac ventricles as well as skeletal muscles.

Ankyrin Repeat↗
PubMed2001

[Ca2+]i-dependent actions of taurine in spontaneously beating rabbit sino-atrial nodal cells.

Modulation by taurine of the pacemaking activity and the underlying ionic currents in rabbit sino-atrial nodal cells was investigated at low and high cellular Ca2+ concentrations ([Ca2+]i) using a patch-clamp technique. At both pCa 8 and 6, taurine depressed the spontaneous activity, more strongly at pCa 6 than at pCa 8. Taurine, 20 mM, markedly inhibited the L-type Ca2+ current: by 56.9+/-2.8% (n=6, P<0.001) at pCa 8, and by 97.6+/-3.8% (n=7, P<0.001) at pCa 6. Also at 20 mM, taurine decreased the delayed rectifier K+ current by 26.8+/-2.6% (n=6, P<0.01) at pCa 6, whereas taurine had less or no effect at pCa 8. The hyperpolarization-activated inward current also decreased at both pCa 8 and 6, by 18.3+/-1.3% (n=8, P<0.05) and by 20.8+/-3.3% (n=8, P<0.05) in 20 mM taurine, respectively. Taurine caused a more potent inhibitory effect at pCa 6. Taurine often elicited dysrhythmias, at 20 mM, in 3 of 17 cells at pCa 8 and in 12 of 16 cells at pCa 6. During washout, the incidence of dysrhythmias or arrest increased further. These results indicate that taurine exerts more potent inhibitory actions on ionic currents under Ca2+ overload conditions in rabbit sino-atrial nodal cells. However, taurine would possibly elicit a cellular Ca2+ overload, when taurine application was discontinued.

Action Potentials↗