Biomedical subjects

Junji Ito

Publications and source records attributed to Junji Ito.

14 recordsLinked to original sources

PubMed2006

Majority of Actinomadura clinical isolates from sputa or bronchoalveolar lavage fluid in Japan belongs to the cluster of Actinomadura cremea and Actinomadura nitritigenes, and the description of Actinomadura chibensis sp. nov.

In Japan during 1996-2004, 21 actinomycete strains that have madurose as the diagnostic cell-wall sugar and show true branching in their substrate and aerial mycelia were isolated from sputa or bronchoalveolar lavage (BAL) fluid of patients with pulmonary infections or who were suspected of having related infections. Chemotaxonomic studies showed that all the isolates belong to the genus Actinomadura. Among them, six and seven strains were classified respectively into clusters of Actinomadura nitritigenes and Actinomadura cremea based on 16S rDNA analyses because their 16S rDNA similarities to those respective species were greater than 99.5%. To our knowledge, this is first report that strains of above two species were isolated from clinical specimens. Neither Actinomadura madurae nor Actinomadura pelletieri strain was isolated, and one new species, Actinomadura chibensis, was proposed; the remaining seven strains were not assigned into any known species, suggesting the presence of another new Actinomadura species.

Actinobacteria↗

PubMed2006

Morphological evaluation of the human facial muscles.

The facial muscles are composed of striated muscle fibers, as well as other skeletal muscles, and can produce more delicate and complex expressions. We studied 12 facial muscles of 10 Japanese cadavers (8 males and 2 females, average 74.7 years old) by histological techniques. We measured the cross-sectional area of the muscle belly (mm2), number of muscle fibers per mm2, total number of muscle fibers, and muscle fiber size (microm2). The depressor anguli oris m. was predominant for the cross-sectional area and the total number of muscle fibers than other facial muscles. For the muscle fiber size, muscles inserted to the angle of the mouth were larger than those inserted to the lip. The orbicularis oculi and orbicularis oris muscles were the smallest facial muscles. The muscle fiber sizes in the facial muscles were less than other skeletal muscles.

Aged↗

PubMed2005

Axial symptoms after cervical laminoplasty with C3 laminectomy compared with conventional C3-C7 laminoplasty: a modified laminoplasty preserving the semispinalis cervicis inserted into axis.

STUDY DESIGN: Results of C4-C7 laminoplasty with C3 laminectomy and C3-C7 laminoplasty were compared. OBJECTIVES: To clarify prospectively whether the modified laminoplasty preserving the semispinalis cervicis inserted into C2 could reduce the axial symptoms compared with conventional laminoplasty reattaching the muscle to C2. SUMMARY OF BACKGROUND DATA: Intraoperative damage of the semispinalis cervicis is relevant to the development of axial symptoms after laminoplasty. In C3-C7 laminoplasty, however, it is difficult to preserve the muscle insertion into C2 while opening the C3 lamina. METHODS: The axial symptoms of 40 patients (Group A) with C4-C7 laminoplasty with C3 laminectomy were compared with those of 16 patients (Group B) with C3-C7 laminoplasty. The cross-sectional areas of the cervical posterior muscles were measured on magnetic resonance images. RESULTS: The number of patients with no postoperative axial symptoms increased (P = 0.035) from 19% to 52.5%, and the number of patients whose symptoms worsened after surgery decreased (P = 0.020) from 50% to 17.5%. The average atrophy rate of cross-sectional area was smaller (P < 0.001) in Group A (2.4%) than in Group B (10.8%). CONCLUSIONS: This method was less invasive to the cervical posterior muscles than C3-C7 laminoplasty. This is an effective procedure for preventing postoperative axial symptoms.

Adult↗

PubMed2005

Inadvertent C2-C3 union after C1-C2 posterior fusion in adults.

INTRODUCTION: Some authors pointed out that there were more than a few patients with inadvertent C2-C3 union after C1-C2 posterior fusion, although few detailed studies of C2-C3 union have been reported. The purpose of this study was to clarify whether C2-C3 union accelerated adjacent C3-C4 disc degeneration after C1-C2 posterior fusion and to investigate the related factors for C2-C3 union. METHODS: Sixteen patients with rheumatoid arthritis (RA group) (4 males, 12 females, mean age 60 years, mean follow-up period 4 years and 3 months) and fifteen patients without RA (non-RA group) (11 males, 4 females, mean 52 years, mean follow-up period 3 years and 10 months) who underwent C1-C2 posterior fusion were radiologically assessed. The C2-C3 union was defined as trabecular bone formation at C2-C3 interlamina in lateral radiograph. C3-C4 disc height was measured to evaluate the disc degeneration. RESULTS: C2-C3 union rate was 56% and 60% in RA group and non-RA group, respectively. In RA group, postoperative C3-C4 disc height was lower (Student's t-test, P = 0.029) and the decrease rate of C3-C4 disc height was higher (Student's t-test, P = 0.015) in patients with C2-C3 union than in patients without C2-C3 union. In non-RA group, the age at operation was older (Student's t-test, P = 0.0007), and the C1-C2 fusion angle (Student's t-test, P = 0.012) was smaller in patients with C2-C3 union than in patients without C2-C3 union. CONCLUSIONS: C2-C3 union after C1-C2 posterior fusion occurred in more than half of both groups. Inadvertent C2-C3 union should be considered a radiological complication and a potential risk factor due to acceleration of C3-C4 disc degeneration in RA.

Adult↗

PubMed2005

Phase synchronization analysis of EEG during attentional blink.

The attentional blink (AB) phenomenon occurs when perceivers must report two targets embedded in a sequence of distracters; if the first target precedes the second by 200-600 msec, the second one is often missed. We investigated AB by measuring dynamic cross-lag phase synchronization for 565 electrode pairs in 40-Hz-range EEG. Phase synchrony, on average, was higher in experimental conditions, where two targets are reported, than in control conditions, where only the second target is reported. The effect occurred in electrode pairs covering the whole head. Timing of the synchrony was crucial: Brief episodes of enhanced synchrony occurred 100-500 msec before expected target onset in AB conditions where the second target was correctly reported. These results show that intrinsic brain dynamics produce anticipatory synchronization in transient assemblies of cortical areas. Enhanced levels of anticipatory synchronization occur in response to the demands of the task in conditions where the system's limited capacity is under strain.

Adolescent↗

PubMed2005

Morphometric evaluation of the human tractus solitarius.

We measured the cross-sectional area (CSA) of the human tractus solitarius (HTS) with the help of an image-analyzer system on a cross section of the upper part of the medulla oblongata in 44 Japanese cadavers (22 males and 22 females) and examined the relationship between age, sex and whether the subjects were dentulous or edentulous. The results showed no significant differences between the left and right sides of the HTS in either male or female subjects. However, the size of HTS decreased slightly with age in males but not at all in females, whereas tooth loss had a definite incidence on the size of HTS in females but not in male, as the CSA was smaller in edentulous females but not in edentulous males. This would tend to indicate that a decreases in taste function is connected with the aging process in male, and with tooth loss in females.

Age Factors↗

PubMed2004

Spatial and temporal structure of phase synchronization of spontaneous alpha EEG activity.

Spatiotemporal characteristics of spontaneous alpha EEG activity patterns are analyzed in terms of large-scale phase synchronization. During periods with strong phase synchronization over the entire scalp, phase patterns take either of two forms; one is a gradual phase shift between frontal and occipital regions and the other is a stepwise pattern with a sudden phase shift in the central region. The former is regarded as a traveling wave of electrocortical activity, of which the direction of propagation is predominantly from anterior to posterior in three out of four subjects, and opposite in the remaining one. The other activity pattern observed may correspond to a standing wave composed of two traveling waves propagating in opposite directions. The duration distributions of these patterns have similar forms within a subject, which suggests that they share the same mechanism for their generation.

Adolescent↗

PubMed2004

Synergistic saccharification, and direct fermentation to ethanol, of amorphous cellulose by use of an engineered yeast strain codisplaying three types of cellulolytic enzyme.

A whole-cell biocatalyst with the ability to induce synergistic and sequential cellulose-degradation reaction was constructed through codisplay of three types of cellulolytic enzyme on the cell surface of the yeast Saccharomyces cerevisiae. When a cell surface display system based on alpha-agglutinin was used, Trichoderma reesei endoglucanase II and cellobiohydrolase II and Aspergillus aculeatus beta-glucosidase 1 were simultaneously codisplayed as individual fusion proteins with the C-terminal-half region of alpha-agglutinin. Codisplay of the three enzymes on the cell surface was confirmed by observation of immunofluorescence-labeled cells with a fluorescence microscope. A yeast strain codisplaying endoglucanase II and cellobiohydrolase II showed significantly higher hydrolytic activity with amorphous cellulose (phosphoric acid-swollen cellulose) than one displaying only endoglucanase II, and its main product was cellobiose; codisplay of beta-glucosidase 1, endoglucanase II, and cellobiohydrolase II enabled the yeast strain to directly produce ethanol from the amorphous cellulose (which a yeast strain codisplaying beta-glucosidase 1 and endoglucanase II could not), with a yield of approximately 3 g per liter from 10 g per liter within 40 h. The yield (in grams of ethanol produced per gram of carbohydrate consumed) was 0.45 g/g, which corresponds to 88.5% of the theoretical yield. This indicates that simultaneous and synergistic saccharification and fermentation of amorphous cellulose to ethanol can be efficiently accomplished using a yeast strain codisplaying the three cellulolytic enzymes.

Cellulase↗

PubMed2003

Spontaneous structure formation in a network of dynamic elements.

To discover the generic behaviors of dynamic networks, we study a coupled map system with variable coupling strength. It is found that this system spontaneously forms various types of network structure according to the parameter values. Depending on the synchronized or desynchronized motion of unit dynamics, the network structure can be either static or dynamic. The separation of units into two groups, one composed of units with a large number of outgoing connections and the other units with little outgoing connections, is observed in dynamic structure. It is revealed that the mechanism for such separation is a positive feedback between unit and connection dynamics.

Journal Article↗

PubMed2003

Perceptual switching, eye movements, and the bus paradox.

According to a widely cited finding by Ellis and Stark (1978 Perception 7 575-581), the duration of eye fixations is longer at the instant of perceptual reversal of an ambiguous figure than before or after the reversal. However, long fixations are more likely to include samples of an independent random event than are short fixations. This sampling bias would produce the pattern of results also when no correlation exists between fixation duration and perceptual reversals. When an appropriate correction is applied to the measurement of fixation durations, the effect disappears. In fact, there are fewer actual button-presses during the long intervals than would be expected by chance. Moving-window analyses performed on eye-fixation data reveal that no unique eye event is associated with switching behaviour. However, several indicators, such as blink frequency, saccade frequency, and the direction of the saccade, are each differentially sensitive to perceptual and response-related aspects of the switching process. The time course of these indicators depicts switching behaviour as a process of cascaded stages.

Adult↗

PubMed2003

Human lower limb muscles: an evaluation of weight and fiber size.

Morphological study of the lower limb muscles is necessary for the analysis of muscle function and its relation to the aging process. In this study, we measured the muscle weight and the muscle fiber morphometry (cross-sectional area and total number of muscle fibers at the muscular belly, and muscle fiber size) of the human lower limb in an adult Japanese cadaver (male, 58 years old). The results presented here can provide the normal control data to elucidate the aging process of the human lower limb muscles. The morphological features in the human lower limb muscles were the pronounced enlargement of the gluteus maximus in the hip, the vasti muscles in the thigh and the soleus in the leg.

Humans↗

PubMed2001

Spontaneous structure formation in a network of chaotic units with variable connection strengths.

As a model of temporally evolving networks, we consider a globally coupled logistic map with variable connection weights. The model exhibits self-organization of network structure, reflected by the collective behavior of units. Structural order emerges even without any interunit synchronization of dynamics. Within this structure, units spontaneously separate into two groups whose distinguishing feature is that the first group possesses many outwardly directed connections to the second group, while the second group possesses only a few outwardly directed connections to the first. The relevance of the results to structure formation in neural networks is briefly discussed.

Journal Article↗

PubMedDate not supplied

Improvement of cellulose-degrading ability of a yeast strain displaying Trichoderma reesei endoglucanase II by recombination of cellulose-binding domains.

To improve the cellulolytic activity of a yeast strain displaying endoglucanase II (EGII) from the filamentous fungus Trichoderma reesei QM9414, the genes encoding the cellulose-binding domain (CBD) of EGII, cellobiohydrolase I (CBHI) and cellobiohydrolase II (CBHII) from T. reesei QM9414, were fused with the catalytic domain of EGII and expressed in Saccharomyces cerevisiae. Display of each of the recombinant EGIIs was confirmed using immunofluorescence microscopy. In the case of EGII-displaying yeast strains in which the CBD of EGII was replaced with the CBD of CBHI or CBHII, the binding affinity to Avicel and hydrolytic activity toward phosphoric acid swollen Avicel were similar to that of a yeast strain displaying wild-type EGII. On the other hand, the three yeast strains displaying EGII with two or three tandemly aligned CBDs showed binding affinity and hydrolytic activity higher than that of the yeast strain displaying wild-type EGII. This result indicates that the hydrolytic activity of yeast strains displaying recombinant EGII increases with increased binding ability to cellulose.

Biodegradation, Environmental↗

PubMedDate not supplied

Factors affecting denture use in some institutionalized elderly people.

This study was conducted to assess which factors were related to the ability of elderly residents of nursing homes to use dentures. For 205 patients in two nursing homes in Chuou-ku, Tokyo, dentists and caregivers examined oral status (caries, status of restoration, missing teeth and occlusal support) as well as denture use, Activities of Daily Living (ADL), ability to rinse the mouth, and degree of dementia. Fifty percent of subjects lacked dentures. Seven items were selected for variance in factor analysis. There was a significant relationship between denture use and all analyzed items except age. The items which proved to be significant, included the number of remaining teeth, the ability to rinse, communication, ability to dress/undress, ability to transfer, and eating (Fisher's exact test). A multiple stepwise logistic regression analysis showed that the nonuse of dentures was significantly related to dressing (p<0.01), the number of remaining crowns (p<0.01) and the ability to rinse the mouth (p<0.0001). The nonuse of dentures was also related to the number of remaining teeth and to the disability of hand and oral functions.

Activities of Daily Living↗