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H Futamata

Publications and source records attributed to H Futamata.

At least 19 recordsLinked to original sources
PubMed2002

Functional and structural analyses of trichloroethylene-degrading bacterial communities under different phenol-feeding conditions: laboratory experiments.

The effects of different phenol-feeding conditions on trichloroethylene (TCE) biodegradation and bacterial population structure in an aquifer soil community were studied. The soil sample, minerals, phenol, and TCE were mixed in glass bottles, which were then incubated under three different phenol-feeding conditions. First, phenol was supplied only once at 0.2 mM (condition 0.2P); second, it was added at 2.0 mM (condition 2.0P); and third, it was periodically supplied ten times at 0.2 mM (condition 0.2PS). TCE concentrations remained stable under conditions 0.2P and 2.0P. In contrast, TCE was completely degraded under condition 0.2PS. TCE/phenol-degrading bacteria were enumerated indirectly and functionally by quantitative PCR. The low- K(s) (half saturation constant) group of phenol-degrading bacteria, exhibiting high TCE-degrading activity, yielded a 50-fold higher population under condition 0.2PS than under condition 2.0P. The bacterial community structure under condition 0.2PS was studied by denaturing gradient gel electrophoresis targeting the genes encoding 16S rRNA and the largest subunit of multicomponent phenol hydroxylase. Sequence analysis of the major bands detected indicated the predominance of the low- K(s) group of TCE/phenol-degrading bacteria belonging to beta-Proteobacteria. These results suggest that continuous supplementation with phenol at a low concentration increases the population of the low- K(s) group of TCE/phenol-degrading bacteria.

Bacteria↗
PubMed2001

Diversity in kinetics of trichloroethylene-degrading activities exhibited by phenol-degrading bacteria.

Whole-cell kinetics of phenol- and trichloroethylene (TCE)-degrading activities expressed by 13 phenol-degrading bacteria were analyzed. The Ks (apparent affinity constant in Haldane's equation) values for TCE were unexpectedly diverse, ranging from 11 microM to over 800 microM. The Vmax/Ks values for phenol were three orders of magnitude higher than the values for TCE in all bacteria analyzed, suggesting that these bacteria preferentially degrade phenol rather than TCE. A positive correlation between Ks for phenol and Ks for TCE was found, i.e., bacteria exhibiting high Ks values for phenol showed high Ks values for TCE, and vice versa. A comparison of the Ks values allowed grouping of these bacteria into three types, i.e., low-, moderate- and high-Ks types. Pseudo-first-order degradation-rate constants for TCE at 3.8 microM were found to be adequate to rapidly discriminate among the three types of bacteria. When bacteria were grown on phenol at the initial concentration of 2 mM, Comamonas testosteroni strain R5, a representative of low-Ks bacteria, completely degraded TCE at 3.8 microM, while strain P-8, a representative of high-Ks bacteria, did not. A mixed culture of these two bacteria poorly degraded TCE under the same conditions, where P-8 outgrew R5. These results suggest that low-Ks bacteria should be selectively grown for effective bioremediation of TCE-contaminated groundwater.

Betaproteobacteria↗
PubMed2001

Bacterial populations occuring in a trichloroethylene-contaminated aquifer during methane injection.

Soil core samples were obtained from a trichloroethylene (TCE)-contaminated aquifer before and after the start of methane biostimulation. DNA was extracted directly from the soil samples, and denaturing gradient gel electrophoresis (DGGE) was used to analyse bacterial 16S ribosomal DNA fragments that were PCR amplified from these DNA samples. This analysis consistently detected two phylotypes in the methane-injected samples. These phylotypes were closely related to Methylobacter and Methylomonas, both belonging to type I methanotrophs. A competitive DGGE analysis using Methylosinus trichosporium OB3b cells as an internal quantitative standard showed that these populations accounted for 10(8)-10(9) cells g(-1) soil. These results showed that type I methanotrophs formed a significant proportion of the bacterial community during methane biostimulation. The implications of this finding for TCE bioremediation were discussed.

Biodegradation, Environmental↗
PubMed2001

Group-specific monitoring of phenol hydroxylase genes for a functional assessment of phenol-stimulated trichloroethylene bioremediation.

The sequences of the largest subunit of bacterial multicomponent phenol hydroxylases (LmPHs) were compared. It was found that LmPHs formed three phylogenetic groups, I, II, and III, corresponding to three previously reported kinetic groups, low-K(s) (the half-saturation constant in Haldane's equation for trichloroethylene [TCE]), moderate-K(s), and high-K(s) groups. Consensus sequences and specific amino acid residues for each group of LmPH were found, which facilitated the design of universal and group-specific PCR primers. PCR-mediated approaches using these primers were applied to analyze phenol/TCE-degrading populations in TCE-contaminated aquifer soil. It was found that the aquifer soil harbored diverse genotypes of LmPH, and the group-specific primers successfully amplified LmPH fragments affiliated with each of the three groups. Analyses of phenol-degrading bacteria isolated from the aquifer soil confirmed the correlation between genotype and phenotype. Competitive PCR assays were used to quantify LmPHs belonging to each group during the enrichment of phenol/TCE-degrading bacteria from the aquifer soil. We found that an enrichment culture established by batch phenol feeding expressed low TCE-degrading activity at a TCE concentration relevant to the contaminated aquifer (e.g., 0.5 mg liter(-1)); group II and III LmPHs were predominant in this batch enrichment. In contrast, group I LmPHs overgrew an enrichment culture when phenol was fed continuously. This enrichment expressed unexpectedly high TCE-degrading activity that was comparable to the activity expressed by a pure culture of Methylosinus trichosporium OB3b. These results demonstrate the utility of the group-specific monitoring of LmPH genes in phenol-stimulated TCE bioremediation. It is also suggested that phenol biostimulation could become a powerful TCE bioremediation strategy when bacteria possessing group I LmPHs are selectively stimulated.

Betaproteobacteria↗
PubMed1999

Characterization of a high-affinity phenol hydroxylase from Comamonas testosteroni R5 by gene cloning, and expression in Pseudomonas aeruginosa PAO1c.

Comamonas testosteroni strain R5 is a phenol-degrading bacterium which expresses a phenol-oxygenating activity that is characterized by low Ks (the apparent half-saturation constant in Haldane's equation) and low K(SI) (the apparent inhibition constant) values. We have now cloned the gene cluster encoding a phenol hydroxylase (phcKLMNOP) and its cognate regulator (phcR) from strain R5. Transformation of Pseudomonas aeruginosa PAO1c (Phenol Catechol+) with pROR502, a derivative of pRO1614 containing the cloned genes, confers the ability to grow on phenol as the sole carbon source. The Ks and K(SI) values for the phenol-oxygenating activity of PAO1c(pROR502) are almost identical to those of strain R5, suggesting that the phcKLMNOP genes encode the major phenol hydroxylase in strain R5. A phylogenetic analysis shows the phenol hydroxylase from strain R5 to be more closely related to toluene/benzene-2-monooxygenase (Tb2m) from Pseudomonas sp. JS150 than to the phenol hydroxylases from P. putida CF600 and BH, or to the phenol hydroxylase from Ralstonia eutropha E2. Analysis of the substrate specificity of PAO1c(pROR502) and PAO1c derivatives expressing phenol hydroxylase from P. putida BH or from R. eutropha E2 indicates that these phenol hydroxylases catalyze the oxidation not only of phenol and cresols but also of toluene and benzene.

Base Sequence↗
PubMed1998

Molecular detection, isolation, and physiological characterization of functionally dominant phenol-degrading bacteria in activated sludge.

DNA was isolated from phenol-digesting activated sludge, and partial fragments of the 16S ribosomal DNA (rDNA) and the gene encoding the largest subunit of multicomponent phenol hydroxylase (LmPH) were amplified by PCR. An analysis of the amplified fragments by temperature gradient gel electrophoresis (TGGE) demonstrated that two major 16S rDNA bands (bands R2 and R3) and two major LmPH gene bands (bands P2 and P3) appeared after the activated sludge became acclimated to phenol. The nucleotide sequences of these major bands were determined. In parallel, bacteria were isolated from the activated sludge by direct plating or by plating after enrichment either in batch cultures or in a chemostat culture. The bacteria isolated were classified into 27 distinct groups by a repetitive extragenic palindromic sequence PCR analysis. The partial nucleotide sequences of 16S rDNAs and LmPH genes of members of these 27 groups were then determined. A comparison of these nucleotide sequences with the sequences of the major TGGE bands indicated that the major bacterial populations, R2 and R3, possessed major LmPH genes P2 and P3, respectively. The dominant populations could be isolated either by direct plating or by chemostat culture enrichment but not by batch culture enrichment. One of the dominant strains (R3) which contained a novel type of LmPH (P3), was closely related to Valivorax paradoxus, and the result of a kinetic analysis of its phenol-oxygenating activity suggested that this strain was the principal phenol digester in the activated sludge.

Acinetobacter↗
PubMed1997

[Topographic analysis of resting EEG and photic driving responses in patients with presenile Alzheimer's disease].

Topographic analysis of the resting EEG was performed in nine patients with presenile Alzheimer's disease(AD) and nine sex- and age-matched normal subjects. We also analyzed EEG activity recorded during photic stimulation(5, 10 and 15 Hz) to evaluate photic driving responses. The square root of absolute power was determined for each frequency band using a Fast Fourier Transform. Compared with the controls, the AD patients had increased delta and theta in the resting EEG mainly over the frontal regions. The patients also had reduced alpha and beta, and did not show posterior predominance of alpha activity. EEG analysis during photic stimulation showed that the patients had a reduction in photic driving responses, and significant topographic differences were found over the parieto-occipital regions. These findings provide further evidence that AD patients have background EEG slowing with a reduction in alpha and fast activity. They also suggest an impairment of visual functioning in AD.

Alzheimer Disease↗
PubMed1997

[Effects of head-up tilting on vagal nerve activity in man].

OBJECTIVES: To evaluate the contribution of the vagal nerve activity in the cardiovascular postural adaptation, effects of decremental head-up tilting (90 degrees, 64 degrees, 53 degrees, 44 degrees, 37 degrees, 30 degrees, 24 degrees, 17 degrees, 12 degrees, 6 degrees and 0 degree) on time- and frequency-domain heart rate variability variables were analyzed in healthy young female. BACKGROUND: During head-up tilting, a hydrostatic venous pooling in the extremities occurs owing to gravity. To pump up the blood toward the upper body, the sympathetic nerve activity has been shown to play an important role. So, to date, few studies evaluated the effects of vagal nerve activity to stabilize the cerebral blood flow during head-up tilting. METHODS: Eight young female volunteers (age, 23.3 +/- 0.8 years; mean +/- SD) were evaluated. The electrocardiogram (ECG) by bipolar chest leads was recorded continuously during procedures, and the bed was tilted at 0.1 interval of sine function of tilting angle from upright position (90 degrees) to supine position (0 degree). The time domain measurements of cycle length variability (co-efficient of variance in percent for R-R intervals [CVRR], number of differences between adjacent R-R intervals that are > 50ms [RR50]) and the frequency domain measurements of low (0.08 to 0.15Hz, LF), high (0.15 to 0.40Hz, HF) and total (0.08 to 0.40, TF) power were performed to assess the cardiac sympathetic and vagal nerve activity. RESULTS: The CVRR showed no significant change during decremental head-up tilting, whereas the RR50 and the square root of HF power, more specific indices of cardiac parasympathetic tone, showed significant negative linear correlations to the sine of the tilting angle. In markers of cardiac sympathetic tone, there were significant positive correlations between the sine of the tilting angle and the normalized LF power or the LF-to-HF power ratio (LF/HF). CONCLUSION: These findings suggest that, in healthy young female, not only cardiac sympathetic nervous system but also cardiac vagal nervous system respond linearly to the change in body axis component of gravity, and they may contribute reciprocally and coordinately to cardiovascular postural adaptation.

Adult↗
PubMed1996

[Median nerve somatosensory evoked potentials--studies on latency variability as a function of subject height and age].

Somatosensory evoked potentials (SEP) to median nerve stimulation were studied in a group of 61 healthy volunteers (36 men, 25 women) between 15 and 79 years of age. The absolute peak latencies of peripheral N9, Erb, cervical N11 and N13, cortical N20, N32 and N60 were analyzed as a function of height and age. Three interpeak latencies, Erb-N13, Erb-N20 and N13-N20, were equally studied. There was no gender difference in the latencies and interpeak latencies of SEP in multiple correlation analysis involving height and age. Multiple regression analysis showed that except for N60 peak latency, the subject's height and age provided better prediction of other SEP latencies, and Erb-N13 and Erb-N20 interpeak latencies than simple and polynomial [correction of polynominal] linear regression. Multiple regression analysis was found to provide better optimal clinical upper limits for individual SEP latencies and interpeak latencies, and may increase the diagnostic sensitivity. The t-value of the multiple regression coefficient for standardized height and standardized age showed that the effects of age on N32 and N60 peak latencies, and on Erb-N13 and Erb-N20 interpeak latencies were a more important factor than those of height. A negative correlation was found between height and age in our subjects. Although this may be a characteristic of modern Japanese, it suggests the necessity of renewing regression models at intervals of 5 or 10 years.

Adolescent↗
PubMed1995

[Sex-related differences in EEG coherence in normal young adults--evaluation during rest and photic stimulation].

EEG coherence is a noninvasive technique for studying functional relationships between brain regions. Although EEG coherence would be a useful method to explore the differences in cerebral functional organization between the sexes, sex differences in coherence have not been well documented. The present study was conducted therefore to examine sex differences in interhemispheric EEG coherence during rest and photic stimulation (PS) in 15 male and 15 female healthy young adults. Interhemispheric coherence of the resting EEG revealed no significant sex differences for any frequency band. In contrast, coherence during PS revealed significant sex differences, and the females had a significantly higher coherence than the males in the frequency band (4.5-5.5Hz) corresponding to 5Hz PS. In addition, the changes in interhemispheric coherence from rest to the stimulus condition (i.e., coherence reactivity) showed sex differences at the brain region primarily involved in visual functioning; the females had significantly greater coherence reactivity for O1-O2 in EEG during PS at 5 and 15Hz. These findings indicate sex differences in interhemispheric EEG coherence during PS, and provide further evidence that sex-related differences exist in the degree of lateralization of hemispheric function.

Adult↗
PubMed1995

[Sex differences in EEG background activity: a study with quantitative analysis in normal adults].

The present study performed quantitative EEG analysis in normal 20 males and 20 females, aged 18-26 years, in order to examine the sex differences in EEG activity at rest. The females had more absolute EEG power than the males, with significant differences observed for delta, theta and beta bands. In contrast, no significant difference was found in peak alpha frequency or relative EEG power for any frequency band. The present findings provide further evidence that females have more absolute power in resting EEG, and emphasize the importance of matching patients and control populations for sex in future investigations dealing with the relationship between resting EEG and various pathological conditions.

Adolescent↗
PubMed1995

[Tibial nerve somatosensory evoked potentials: studies on latency variability as a function of subject height and age].

Scalp-recorded somatosensory evoked potentials (SEP) to posterior tibial nerve stimulation were studied in healthy volunteers (27 males and 25 females) aged 15-67 years. Age alone was not correlated with SEP latencies, except for P 60 latency, but multiple regression analysis with two independent variables (height and age) showed that not only height but also age is a significant parameter in determining the optimal clinical limits for individual SEP latencies, and may increase the diagnostic sensitivity of absolute SEP latencies. There was no gender difference in the latencies of SEP in multiple correlation analysis involving height and age. A negative correlation tended to be found between height and age in adult subjects, although this is thought to be a characteristic of Japanese, it may show the necessity of renewing regression models at intervals of 5 or 10 years.

Adolescent↗
PubMed1994

[Suppression of myoclonus associated with intermittent photic stimulation (IPS) in a case of Creutzfeldt-Jacob disease: with special reference to the specificity of IPS frequency].

The present study deals with electrophysiological findings 3 months after the patient fell into an apallic state during the course of Creutzfeldt-Jacob disease (CJD), when periodic limb myoclonus synchronizing with periodic synchronous discharge (PSD) began to diminish. The findings were as follows: On 2 Hz intermittent photic stimulation (IPS), myoclonus and the diffuse bisynchronous high amplitude sharp wave showed dissociation; the myoclonus was completely suppressed, while the high amplitude sharp wave was elicited. On 3 Hz IPS, myoclonus was incompletely suppressed, corresponding to every other high amplitude sharp waves which were induced synchronous to IPS. On 1 Hz IPS, the high amplitude sharp waves were scarcely induced while neither PSD nor the myoclonus were suppressed. The frequency of the PSD was about 1.2 Hz. Based on these findings, we propose that in addition to the cortical refractory period after PSD or the giant response to photic stimulation, there must be another refractory period in the distal impulse pathway longer than the cortical one. Although the exact electrophysiological mechanism involved in the present findings remains unknown, the possible mechanism responsible for the suppression of myoclonus by IPS and the specificity of IPS frequency in the suppression could be due to competitive suppression of the impulse between periodic myoclonus and the cortical reflex myoclonus through the interaction of the two independent refractory periods in the transmission pathway of the impulse.

Aged↗
PubMed1994

[Quantitative analysis of EEG background activity in drug-naive schizophrenic patients].

In this study we performed quantitative EEG analyses in 12 drug-naive patients who fulfilled DSM-IIIR criteria for schizophrenia and in a group of 12 healthy subjects. The schizophrenic patients were found to have slower activity (delta and theta) than the controls. These differences were most marked in the frontal region for delta band and in the occipital region for theta band. The schizophrenic patients also had more beta 1 activity, particularly in the occipital leads. Conversely, they had less alpha 2 activity over all regions examined. Our findings indicate cerebral dysfunction in schizophrenia and are in line with the hypothesis of hypofrontality in this disorder.

Adult↗
PubMed1991

[EEG data filing system with personal computer and magneto-optical disc].

We established a new computerized EEG filing system, in which an EEG machine was connected to an EEG filing unit which consisted of a personal computer with a 32 bit CPU, 18 channel analog -to-digital and digital-to-analog converters, and a magneto-optical disc driver. This system has the following merits. The system was space-saving, the space required to store the EEG data, being only 1/500 of that required for storing EEG record. Though the system had two independent EEG filing units, our original file configuration enabled us to have access to all of the recorded EEG data anytime for more than 10 years. The system enabled us to display EEG data continuously on the high resolution CRT, just as if turning the page of an EEG record paper, and through the quick scanning, enabled us to view the entire EEG pattern. Furthermore, the system enabled us to conduct reliable digital analysis for EEG data by entering the EEG data without artifacts into a data processor after confirmation on the display. In the system, we used data files with the MS-DOS operating system. This enabled us to analyze the data obtained by a personal computer operating on other systems, by transferring the data to a floppy disc operating on our system. Our EEG filing system allows quick access to data as well as mass data storage.

Electroencephalography↗
PubMed1990

[Study of quantitative measurement of tricuspid regurgitation using Doppler echocardiography].

The volume of tricuspid regurgitation (VTR) was measured using two-dimensional color and continuous wave Doppler echocardiography. The value of VTR showed significant correlations with the maximum area (r = 0.77), the maximum distance (r = 0.73) and the maximum width (r = 0.59) in the regurgitant signal, right ventricular pressure (r = 0.63) and the diameter of right atrium (r = 0.40). When the tricuspid regurgitation was divided into two types in viewpoint of its flow direction-flow directed to center of atrium (A type) and that directed to atrial septum (B type), VTR showed closer correlations with the maximum area (r = 0.90) and the maximum distance (r = 0.87) in A type. But in B type, their relativities were decreased (r = 0.51 and r = 0.40, respectively). The VTR was well related with the severity of tricuspid regurgitation based on the Miyatake's classification. This evidence indicated that the quantitative measurement of tricuspid regurgitant volume using two-dimensional color and continuous wave Doppler echocardiography is more accurate and useful compared with conventional semi-quantitative method.

Adult↗
PubMed1990

[Potentiating effect of spirometric maneuver on bronchial responsiveness to methacholine in asthmatic subjects--the role of deep inspiration and forced expiration].

We previously reported that spirometric maneuver (SM) had potentiating effect on bronchial responsiveness (BR) in asthmatic subjects but not in normal subjects. SM consists of deep inspiration to TLC (DI) and forced expiration to RV (FE). In this study, we examined the effect of SM, DI and FE on BR in 9 asthmatic subjects. Provocative concentration of methacholine producing a 35% fall in respiratory conductance (PC35-Grs) was significantly (p less than 0.02 and p less than 0.025) decreased from 0.34 mg/ml (GSEM, 1.51) to 0.16 mg/ml (GSEM, 1.45) and 0.14 mg/ml (GSEM, 1.51) by SM and DI, respectively but it was not altered by FE. These findings indicate that potentiating effect of SM on BR which is characteristic of asthma may be due to DI effect.

Adult↗