Biomedical subjects

M Fujita

Publications and source records attributed to M Fujita.

At least 19 recordsLinked to original sources

PubMed2007

How to make an autonomous robot as a partner with humans: design approach versus emergent approach.

In this paper, we discuss what factors are important to realize an autonomous robot as a partner with humans. We believe that it is important to interact with people without boring them, using verbal and non-verbal communication channels. We have already developed autonomous robots such as AIBO and QRIO, whose behaviours are manually programmed and designed. We realized, however, that this design approach has limitations; therefore we propose a new approach, intelligence dynamics, where interacting in a real-world environment using embodiment is considered very important. There are pioneering works related to this approach from brain science, cognitive science, robotics and artificial intelligence. We assert that it is important to study the emergence of entire sets of autonomous behaviours and present our approach towards this goal.

Artificial Intelligence↗

PubMed2006

HPV16 E6-mediated stabilization of ErbB2 in neoplastic transformation of human cervical keratinocytes.

Whether ErbB2 receptor tyrosine kinase contributes to cervical cancer is controversial. We have examined the effects of E6 and E7 genes of human papillomaviruses type 16 (HPV-16) on ErbB2 expression in primary human cervical keratinocytes (HCK) immortalized with hTERT (HCK1T). In E6-positive cells (HCK1T-E6 and HCK1T-E6E7), ErbB2 expression levels increased with the cell density. HCK1T-E6E7 showed impaired contact inhibition and anchorage-independent growth in soft agar which were abrogated with introduction of ErbB2-specific short hairpin RNA (shRNA) or an ErbB2 specific inhibitor AG825. Furthermore, increased ErbB2 expression was also observed in HPV16 positive cervical cancer cell lines and this was diminished by introduction of HPV16E6- or E6AP-shRNA. At post-confluence cell densities, ErbB2 protein was stabilized in the presence of E6 whereas increased ErbB2 expression was not obvious with E6 mutants incapable of degrading p53. Furthermore, introduction of p53-shRNA to HCK1T resulted in increased ErbB2 protein stability, indicating possible ErbB2 regulation through p53. Finally, we showed that tumor formation of ErbB2-shRNA introduced SiHa cells were almost abolished. Taken together, these data indicate an important role of ErbB2 regulation by HPV16 E6 in oncogenic transformation of human cervical keratinocytes.

Cell Line, Transformed↗

PubMed2006

Effects of light intensity and water temperature on oxygen release from roots into water lettuce rhizosphere.

The oxygen release rate into the rhizosphere by a floating aquatic plant-water lettuce-was determined under various light intensities (0.0-1.2x10(5)lx) and water temperatures (10-35 degrees C). The net specific oxygen release rate was expressed by a model equation comprising the gross oxygen release rate and the rhizosphere respiration terms. Experimental and simulated results show that the net specific oxygen release rate increased with light intensity up to the optimal value, but slight inhibition by higher light intensities was observed at 10-20 degrees C. With increased water temperature, the respiration rate became larger than the gross oxygen release rate. The maximum net specific oxygen release rate of 11.0-12.5mg-O(2)kg-wet(-1)h(-1) was obtained at the optimal condition of about 25 degrees C and 9.0x10(4)-1.1x10(5)lx. The net oxygen release rate was negligible at 35 degrees C at any light intensity because the respiration rate was much greater than the gross oxygen release rate into the rhizosphere.

Hydroponics↗

PubMed2006

Target preparation by the precipitation method for nuclear reactions.

A technique for preparing nuclear reaction targets of various thicknesses was developed by using common filtration technique of hydroxide precipitates with a porous Al(2)O(3) membrane filter. Uniformity was found to be within a few % in each thickness. Durability for beam irradiation was also confirmed. The preparation procedure is convenient and the method is appropriate for several target materials, including not only precious materials but also radioactive materials with low contamination.

Aluminum Oxide↗

PubMed2006

Electron-phonon coupling reflecting dynamic charge inhomogeneity in copper oxide superconductors.

The attempt to understand copper oxide superconductors is complicated by the presence of multiple strong interactions in these systems. Many believe that antiferromagnetism is important for superconductivity, but there has been renewed interest in the possible role of electron-lattice coupling. The conventional superconductor MgB2 has a very strong electron-lattice coupling, involving a particular vibrational mode (phonon) that was predicted by standard theory and confirmed quantitatively by experiment. Here we present inelastic scattering measurements that show a similarly strong anomaly in the Cu-O bond-stretching phonon in the copper oxide superconductors La(2-x)Sr(x)CuO4 (with x = 0.07, 0.15). Conventional theory does not predict such behaviour. The anomaly is strongest in La(1.875)Ba(0.125)CuO4 and La(1.48)Nd(0.4)Sr(0.12)CuO4, compounds that exhibit spatially modulated charge and magnetic order, often called stripe order; it occurs at a wave vector corresponding to the charge order. These results suggest that this giant electron-phonon anomaly, which is absent in undoped and over-doped non-superconductors, is associated with charge inhomogeneity. It follows that electron-phonon coupling may be important to our understanding of superconductivity, although its contribution is likely to be indirect.

Journal Article↗

PubMed2006

Peri-prosthetic tuberculous infection of the hip in a patient with no previous history of tuberculosis.

We report a case of peri-prosthetic tuberculous infection nine years after total hip arthroplasty in a patient with no history of tuberculosis before the procedure. Further investigation revealed active pulmonary tuberculosis which was thought to have spread haematogeneously to the arthroplasty. The infection did not respond to standard antituberculous drugs. Removal of the prosthesis and insertion of an antibiotic spacer were required.

Aged↗

PubMed2006

Evaluation of hydrological processes in a mountainous small basin using a quinone biomarker.

An applicability of quinone biomarker to the analysis of hillslope runoff was investigated. At first, quinone profiles of three streams as well as a hillslope runoff in a forested headwater catchment were compared. The quinone composition of hillslope runoff differed from others. Moreover, there were remarkable differences in quinone profile of hillslope runoff under different rainfall conditions. Then, the behavior of quinone biomarker during the increase and decrease of hillslope runoff after a rainfall event was examined. The fractional changes in Q-9 (H2), Q-10 (H2), Q-11, MK-6 and MK-10 suggested the effect of interflow.

Biomarkers↗

PubMed2006

Biodegradation of a variety of bisphenols under aerobic and anaerobic conditions.

There is a group of compounds structurally similar to bisphenol-A (BPA), namely bisphenols (BPs), and some of them are considered to be able to partially replace BPA. In order to assess their biodegradability in the aquatic environment, a variety of BPs; BPA, bis(4-hydroxyphenyl)methane (BPF), bis(4-hydroxyphenyl)ethane (BPE), 2,2-bis(4-hydroxy-phenyl)butane (BPB), 2,2-bis(4- hydroxy-3-methylphenyl)propane (BPP), bis(4-hydroxyphenyl)sulfone (BPS), thiodiphenol (TDP) and 4,4'-dihydroxybenzophenone (HBP); were subjected to biodegradation tests under both aerobic and anaerobic conditions. For the aerobic degradation test, a kind of river-die-away method using several river water samples was used, while pond sediments were used for the anaerobic degradation tests in sealed anoxic bottles. As a whole, the examined BPs could be ranked by their biodegradability under aerobic conditions; BPF, HBP > > BPA > BPP > BPE > BPB > TDP > > BPS. On the other hand, the tendency for the anaerobic biodegradability was; BPF > HBP > BPS, BPA, TDP > BPE > BPB. From the viewpoint of biodegradability, BPF seems to be more environmentally-friendly than BPA and, therefore, may be a candidate to replace BPA for reducing the environmental risks.

Bacteria, Aerobic↗

PubMed2005

Comparative study on chemical pretreatments to accelerate enzymatic hydrolysis of aquatic macrophyte biomass used in water purification processes.

In this study, enzymatic hydrolysis of two floating aquatic plants which are suitable for water purification, water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes L.), was performed to produce sugars. Twenty chemical pretreatments were comparatively examined in order to improve the efficiency of enzymatic hydrolysis. As a result, the alkaline/oxidative (A/O) pretreatment, in which sodium hydroxide and hydrogen peroxide were used, was the most effective pretreatment in terms of improving enzymatic hydrolysis of the leaves of water hyacinth and water lettuce. The amount of reducing sugars in enzymatic hydrolysate of water lettuce leaves was 1.8 times higher than that of water hyacinth leaves, therefore water lettuce seems to be more attractive as a biomass resource than water hyacinth. Although roots of these plants contained large amounts of polysaccharides such as cellulose and hemicellulose, they generated less monosaccharides than from leaves, no matter which chemical pretreatment was tested.

Araceae↗

PubMed2005

Gene expression analyses in X-linked myotubular myopathy.

BACKGROUND: X-linked myotubular myopathy (XLMTM) is a severe congenital disorder characterized by marked muscle weakness and hypotonia. Myotubularin, the protein product of the causative gene, MTM1, is thought to be a phosphatase for phosphatidylinositol-3-phosphate and may be involved in membrane trafficking. Analysis of MTM1 knocked-out mice indicates that the characteristic small fibers in XLMTM muscles are due to atrophy rather than hypoplasia. OBJECTIVE: To characterize gene expression profiling of skeletal muscles with XLMTM. METHOD: The authors analyzed the expression of more than 4,200 genes in skeletal muscles from eight patients with XLMTM using their custom cDNA microarray. RESULTS: In XLMTM, gene expression analysis revealed pathognomonic upregulation of transcripts for cytoskeletal and extracellular matrix proteins within or around atrophic myofibers. CONCLUSION: Remodeling of cytoskeletal and extracellular architecture appears to contribute to atrophy and intracellular organelle disorganization in XLMTM myofibers.

Cytoskeletal Proteins↗

PubMed2005

Effect of active immunization against inhibin on hormonal concentrations and semen characteristics in Shiba bucks.

Active immunization against inhibin increased ovulation rate in females; in males, the effects of active immunization against inhibin on hormonal concentrations and sperm production need more investigation. To test the hypothesis that active immunization against inhibin increases FSH secretion and sperm output, the present study was undertaken to determine the effects of active immunization against inhibin on hormonal profile and sperm production in Shiba bucks. The bucks were actively immunized against inhibin alpha-subunit (immunized group, n=6) or Freund adjuvant (control group, n=5) four times, at 5-weeks intervals. Blood samples were collected twice-weekly and two successive ejaculates of semen were collected (with an artificial vagina) once-weekly. Plasma concentrations of FSH, LH and testosterone were measured by radioimmunoassay (RIA) and sperm motility characteristics were measured by computer-assisted sperm analysis (CASA). All inhibin-immunized bucks produced antibodies against inhibin. Relative to control bucks, in immunized bucks there were significant increases in plasma FSH concentrations and in sperm concentrations from 5 to 9 weeks and from 8 to 11 weeks, respectively, after primary immunization. However, plasma concentrations of LH and testosterone, semen volume, percentage of motile spermatozoa and motility parameters (straight-line velocity, curvilinear velocity and linearity index) were similar in both groups. In conclusion, active immunization against inhibin alpha-subunit increased FSH secretions and enhanced sperm production in bucks, whereas LH and testosterone concentrations, semen volume and sperm motility parameters were unaffected. Active immunization against inhibin could be used to improve fertility in Shiba bucks.

Animals↗

PubMed2005

Direct observation of a nonmonotonic dx2-y2- wave superconducting gap in the electron-doped high-Tc superconductor Pr0.89LaCe0.11CuO4.

We performed high-resolution angle-resolved photoemission spectroscopy on electron-doped high-Tc superconductor Pr0.89LaCe0.11CuO4 to study the anisotropy of the superconducting gap. The observed momentum dependence is basically consistent with the dx2-y2- wave symmetry, but obviously deviates from the monotonic dx2-y2- gap function. The maximum gap is observed not at the zone boundary, but at the hot spot where the antiferromagnetic spin fluctuation strongly couples to the electrons on the Fermi surface. The present experimental results suggest the spin-mediated pairing mechanism in electron-doped high-Tc superconductors.

Journal Article↗

PubMed2005

Methylation of the oestrogen receptor gene in non-neoplastic epithelium as a marker of colorectal neoplasia risk in longstanding and extensive ulcerative colitis.

BACKGROUND: Surveillance colonoscopy is widely recommended in patients with longstanding and extensive ulcerative colitis (UC) in order to detect colorectal neoplasia at an early stage. However, it still remains questionable whether surveillance colonoscopy effectively enables early detection of UC associated neoplasia. There is a great need for sensitive markers to identify individuals at increased risk of neoplasia. The oestrogen receptor (OR) gene shows age related methylation in the colorectal epithelium and is methylated frequently in sporadic colorectal neoplasia, suggesting that OR methylation may predispose to colorectal neoplasia. AIM: To clarify whether analysis of methylation of the OR gene in non-neoplastic epithelium can contribute to prediction of increased neoplasia risk in UC patients. MATERIALS AND METHODS: A total of 165 non-neoplastic colorectal epithelia from 30 patients with longstanding and extensive UC, including 13 UC patients with neoplasia and 17 patients without, were evaluated. Methylation specific polymerase chain reaction was performed to determine the methylation status of the OR gene. RESULTS: Methylation of the OR gene was detected in 54 of 70 (77.1%) non-neoplastic colorectal epithelia in UC with neoplasia but in only 23 of 95 (24.2%) without neoplasia. Methylation of the OR gene was significantly more frequent in non-neoplastic epithelium from UC with neoplasia than in chronic colitic epithelium from UC without neoplasia. Furthermore, in UC with neoplasia, the OR gene was extensively methylated in non-neoplastic epithelia throughout the colorectum compared with those in UC without neoplasia. CONCLUSION: These results suggest that analysis of OR gene methylation may have potential as a useful marker for identifying individuals at increased risk of neoplasia among those with longstanding and extensive UC.

Aged↗

PubMed2005

Osteocalcin-immunoreactive neurons in the vagal and glossopharyngeal sensory ganglia of the rat.

Immunohistochemistry for osteocalcin (OC) was performed on the rat vagal and glossopharyngeal sensory ganglia. OC-immunoreactive (IR) neurons were detected in the jugular (10%), petrosal (11%) and nodose ganglia (6%). The cell size analysis demonstrated that OC-IR neurons were predominantly small to medium-sized in the jugular ganglion (mean+/-S.D.=356.3+/-192.2 microm(2), range=86.5-831.5 microm(2)). On the other hand, such neurons were medium-sized to large in the petrosal (mean+/-S.D.=725.6+/-280.7 microm(2), range=124.7-1540.4 microm(2)) and nodose ganglia (mean+/-S.D.=857.5+/-330.2 microm(2), range=367.1-1608.0 microm(2)). In the circumvallate papilla, OC-IR nerve fibers were located in the vicinity of taste buds. Some taste bud cells were also immunoreactive for the calcium-binding protein (CaBP). In the carotid body, however, OC-IR nerve fibers could not be detected. Retrograde tracing with fluorogold revealed that OC-IR nerve fibers in the circumvallate papilla mainly originated from the petrosal ganglion. These findings may suggest that OC-IR petrosal neurons have chemoreceptive function in the tongue.

Animals↗

PubMed2005

Characterizing kinetics of transport and transformation of selenium in water-sediment microcosm free from selenium contamination using a simple mathematical model.

This study developed a seven-compartment model for predicting the fate of selenium (Se) in an aquatic environment containing a water-sediment boundary. Speciation of Se in water-sediment microcosms under microaerobic conditions was measured to evaluate first-order kinetics of Se transportation and transformation. The microcosm consisted of a 10-ml solution containing 1mM soluble Se as selenate (Se6+) or selenite (Se4+) and 8 g wet sediment that was free from Se contamination, sampled from the Senri, Yamato, or Yodo Rivers in Osaka, Japan. Stepwise reaction coefficients describing transportation and transformation were determined using an inverse method on this model which includes: selenate (Se(W)6+) and selenite (Se(W)4+) in ponded water; selenate (Se(S)6+) and selenite (Se(S)4+), elemental Se (Se0), organic Se (Se2-) in sediment; and gaseous Se (DMSe). During this 1-month experiment, soluble Se was transported from ponded water to the sediment and Se was transformed sequentially to other Se species through biochemical reactions. Experimental and kinetic analyses indicated quantitatively that the Yamato River microcosm, with its high organic matter content, had a high adsorption rate of soluble Se. The Yodo River microcosm had a low adsorption rate for Se6+ and a low Se reduction rate. The Senri River microcosm had an apparent high volatilization rate of DMSe. The model developed in this study is extremely useful for predicting fate of Se in aquatic environment in the field.

Biological Transport↗

PubMed2005

Effect of antiarrhythmic agents on heart rate variability indices after myocardial infarction: comparative experimental study of aprindine and procainamide.

The cardiac arrhythmic suppression trial (CAST) reported that antiarrhythmic treatments in post-myocardial infarction (MI) patients resulted in poor outcome and decreased in heart rate variability indices (HRV). The goal of the present study was to determine whether aprindine and procainamide, antiarrhythmic agents that increase HRV, result in beneficial effects in post-MI rabbits. Four weeks before experiment, MI was induced in four rabbits by ligating the major branch of left coronary artery. A total of eight rabbits (four post-MI and four normal rabbits) were randomly assigned to treatment with either intravenous aprindine (1 mg/kg) or intravenous procainamide (15 mg/kg). Frequency domain HRV (low frequency spectra, LF, 0.04-0.15 Hz; high frequency spectra, HF, 0.15-0.40 Hz) were assessed by MemCalc software. Aprindine significantly increased HF and LF in both MI and normal rabbits, whereas procainamide tended to decrease HF and LF in MI and normal rabbits (in total rabbits; aprindine, LF, from 6.3 +/- 7.9 to 16.5 +/- 15.0 ms(2)/Hz, P < 0.05; HF, from 8.0 +/- 11.7 to 17.5 +/- 15.0 ms(2)/Hz, P < 0.05; procainamide, LF, from 4.9 +/- 7.4 to 4.8 +/- 8.5 ms(2)/Hz, NS; HF, from 11.1 +/- 23.0 to 5.1 +/- 10.6 ms(2)/Hz, NS). Under pharmacological denervation with propranolol (0.1 mg/kg) and atropine (0.04 mg/kg), aprindine increased LF and HF (LF, from 0.2 +/- 0.2 to 0.8 +/- 0.7 ms(2)/Hz, P < 0.05; HF, from 0.1 +/- 0.0 to 0.2 +/- 0.0 ms(2)/Hz, P < 0.05). These data suggest that aprindine can increase HRV in post-MI rabbits. Further experiments in human subjects would be of benefit.

Adrenergic beta-Antagonists↗

PubMed2005

Eradication of Helicobacter pylori increases platelet count in patients with idiopathic thrombocytopenic purpura in Japan.

BACKGROUND: The effect of Helicobacter pylori eradication on the platelet count in patients with thrombocytopenic purpura is controversial. In this multicentre study, we prospectively assessed the effect of H. pylori eradication therapy in idiopathic thrombocytopenic purpura patients. MATERIALS AND METHODS: Thirty-five consecutive patients with chronic idiopathic thrombocytopenic purpura (11 males and 24 females, a median age of 57) were assessed for H. pylori infection by use of a urea breath test. All patients received 1-week triple therapy (amoxicillin, clarithromycin, and lansoprazole) to eradicate H. pylori. At 6 months, idiopathic thrombocytopenic purpura patients with a platelet count recovery of greater than 100 x 10(9) L(-1) were defined as idiopathic thrombocytopenic purpura responders. RESULTS: Helicobacter pylori infection was observed in 25 (71%) of the 35 patients. All infected patients were cured. Eleven patients were identified as idiopathic thrombocytopenic purpura responders; 24 were considered nonresponders. Platelet counts improved by more than 100 x 10(9) L(-1) in 11 (44%) of the 25 patients cured of H. pylori infection, while none of the 10 patients H. pylori-negative patients experienced the same improvement (P = 0.015). Univariate analysis showed that H. pylori infection and its eradication were significant factors associated with platelet recovery (P = 0.015). CONCLUSIONS: Helicobacter pylori infection played a role in the pathogenesis of idiopathic thrombocytopenic purpura in approximately 30% of all patients assessed and 45% of the patients with H. pylori infection. Eradication of H. pylori in idiopathic thrombocytopenic purpura patients led to improved disease activity.

Adult↗

PubMed2005

Metastatic retinoblastoma of the maxilla and mandible.

Metastatic retinoblastoma of the jaws is very rare. We present a 4-year-old boy with metastatic retinoblastoma that involved both the maxilla and mandible simultaneously. Enhanced CT indicated bone-destructive masses with partially non-enhanced area and enhanced margin in the right maxilla and left mandible. MRI showed well-delineated masses that were isointense on T(1) weighted images and hyperintense on T(2) weighted images. Four weeks after chemotherapy and bone marrow transplantation, the size of lesions remarkably decreased. The patient died 19 months later with extensive tumour metastases despite additional chemotherapy. In this case, the dental crypt of a permanent tooth was considered the potential target through which retinoblastoma metastasized to the jaws.

Child, Preschool↗