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Biomedical subjects

Kyoko Fujita

Publications and source records attributed to Kyoko Fujita.

At least 19 recordsLinked to original sources
PubMed2007

Antitumor effects of ZD6474 on head and neck squamous cell carcinoma.

Angiogenesis is required for tumor growth and metastasis and, therefore, represents a target for cancer treatment. While many factors have been implicated in promoting angiogenesis, vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis. ZD6474 is a potent VEGF receptor-2 (VEGFR-2) tyrosine kinase inhibitor which also has activity against the epidermal growth factor receptor (EGFR) tyrosine kinase. The purpose of this study was to investigate the sensitivity of head and neck squamous cell carcinoma (HNSCC) cell lines to ZD6474, and to evaluate its antitumor efficacy on HNSCC xenografts. This is the first demonstration of antitumor effects of ZD6474 on HNSCC. In vitro ZD6474 displayed antiproliferative effects on HNSCC cells and inhibition of VEGFR-2 and EGFR pathways. In vivo ZD6474 displayed antitumor activity, induced apoptosis and antiangiogenic activity on nude mice bearing an established xenograft of YCU-H891 cells. These results suggest that ZD6474 has the potential to inhibit two key pathways in tumor growth via inhibition of VEGF-dependent tumor angiogenesis and via inhibition of EGFR-dependent tumor cell proliferation.

Animals↗
PubMed2006

Unexpected improvement in stability and utility of cytochrome c by solution in biocompatible ionic liquids.

Proteins generally are only stable in vitro for short periods of time. This results in challenges during isolation and purification of recombinant proteins and reduces the shelf life of protein-based pharmaceuticals. Here we show that certain novel, biocompatible ionic liquids provide a stabilizing solvent for proteins, for example, cytochrome c, such that structure and activity are maintained even after 6 months of storage at room temperature. Normally, this protein would be rendered inactive after only 1 week in buffered aqueous solution. The effect of the ionic liquid solvent appears to be related to protection against hydrolysis.

Animals↗
PubMed2006

Cyclooxygenase 2 expression in rat corneas after ethanol exposure.

PURPOSE: To evaluate the effects of ethanol exposure of the cornea on inflammation in corneal epithelium. SETTING: Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan. METHODS: One cornea of Wistar rats (n = 60) was exposed to ethanol 20% for 30 seconds. The animals were killed 0.5, 1.0, 1.5, 2.0, 6.0, 12.0, 24.0, 48.0, or 72.0 hours or 7 days after treatment. The paraffin section or cryosection of the treated eyes was processed for histology; immunohistochemistry for cyclooxygenase 2 (COX2); p65 subunit of nuclear factor kappa B (NF-kappaB), which is the major transcription factor involved in COX2 expression; phospho-IkappaB; or in situ hybridization for COX2 mRNA. RESULTS: In the uninjured corneas, faint immunoreactivity for COX2 was detected in the basal cells of the corneal epithelium, but not in other cell layers. Cyclooxygenase 2 mRNA was not observed in the injured epithelium; it was expressed 2 hours after ethanol exposure, but not 3 hours or later after treatment. The COX2 protein was detected in the corneal epithelium throughout the epithelial layers from 3 to 72 hours, but not at 7 days. The p65 of NF-kappaB translocated to the nuclei of corneal epithelium 3 to 24 hours after treatment but was not seen in the nuclei 48 hours after treatment. Phospho-I kappaB was detected in corneal epithelium 6 hours after treatment, but not 12 hours or later. CONCLUSION: Ethanol exposure activated NF-kappaB and upregulated COX2 expression, which may cause inflammation in corneal tissue.

Animals↗
PubMed2006

Conjugational transfer kinetics of pLS20 between Bacillus subtilis in liquid medium.

pLS20-mediated conjugational transfer between Bacillus subtilis was investigated not on conventional solid media but in liquid culture. Detailed conjugational kinetics revealed that pLS20 transmission occurred at a limited cellular growth stage of both donor and recipient. Mutation of the recipient recA did not significantly interfere with the conjugational transfer process.

Bacillus subtilis↗
PubMed2006

[Reading performance in patients with central visual field disturbance due to glaucoma].

PURPOSE: To evaluate the relationship between central visual field disturbance due to glaucoma and reading performance. SUBJECTS AND METHODS: We evaluated the reading performance of 11 patients (14 eyes) with visual acuities of 1.0 and higher who had absolute scotoma within 3 degrees of the central visual field. The ages of the patients ranged from 37 to 77, with a median of 62 years. Maximum reading speed of texts printed horizontally and vertically was measured using MNREAD-J. Subjective reading difficulties were investigated orally. The relationship between the maximum reading speed of both horizontal and vertical texts, the subjective reading difficulties, the number of quadrants, and the position and continuity of absolute scotoma were evaluated. RESULTS: The mean maximum reading speed for vertical and horizontal texts by the 11 patients was 323 and 335 characters/minute(c/m), respectively, and was not significantly slower than that of normal eyes. In 2 of 14 eyes, a significant (p < 0.05) difference between maximum vertical and horizontal reading speeds was observed. In 3 of 14 eyes, absolute scotoma was distributed continuously in more than 2 adjacent quadrants, and these patients also had subjective reading difficulties. CONCLUSION: Reading difficulty is present in patients having absolute scotoma within 3 degrees of the central visual field when the scotoma involves more than 2 adjacent quadrants.

Adult↗
PubMed2005

Combining two genomes in one cell: stable cloning of the Synechocystis PCC6803 genome in the Bacillus subtilis 168 genome.

Cloning the whole 3.5-megabase (Mb) genome of the photosynthetic bacterium Synechocystis PCC6803 into the 4.2-Mb genome of the mesophilic bacterium Bacillus subtilis 168 resulted in a 7.7-Mb composite genome. We succeeded in such unprecedented large-size cloning by progressively assembling and editing contiguous DNA regions that cover the entire Synechocystis genome. The strain containing the two sets of genome grew only in the B. subtilis culture medium where all of the cloning procedures were carried out. The high structural stability of the cloned Synechocystis genome was closely associated with the symmetry of the bacterial genome structure of the DNA replication origin (oriC) and its termination (terC) and the exclusivity of Synechocystis ribosomal RNA operon genes (rrnA and rrnB). Given the significant diversity in genome structure observed upon horizontal DNA transfer in nature, our stable laboratory-generated composite genome raised fundamental questions concerning two complete genomes in one cell. Our megasize DNA cloning method, designated megacloning, may be generally applicable to other genomes or genome loci of free-living organisms.

Bacillus subtilis↗
PubMed2005

Protein solubilising and stabilising ionic liquids.

We report a family of biocompatible ionic liquids (ILs) which are able to dissolve significant amounts of proteins such as cytochrome c and in which ATR-FTIR spectroscopy results show retention of secondary structure to extreme temperatures.

Cytochromes c↗
PubMed2005

[Reading performance in the scar stage of age-related macular degeneration].

PURPOSE: To evaluate reading performance in patients with age-related macular degeneration (AMD). SUBJECTS AND METHODS: Six normal subjects over 50 years of age and 40 patients with AMD were evaluated. Near visual acuity, critical print size, and maximum reading speed were tested to compare the data from normal subjects with those from AMD patients. Scanning laser ophthalmoscope (SLO) microperimetry was performed to observe fixation in AMD patients. RESULTS: The mean critical print size for normal subjects was 0.15 logarithm of the minimum angle of resolution (log MAR) and the mean maximum reading speed was 307 characters/min. There was a plateau area in reading function where reading speed did not rise and stayed constant even though print size increased. The mean critical print size for AMD patients was 0.97 log MAR, and the mean maximum reading speed was 140 characters/min. The critical print size and maximum reading speed differed significantly between normal and AMD subjects. Eleven of the 40 patients with AMD did not have the character size and reading speed relationship, which means they manifested a plateau as seen in normal subjects. Eight of the 11 patients did not show stable fixation with SLO microperimetry. CONCLUSIONS: The reading performance of AMD patients was remarkably impaired, especially in those with poorer visual function and no fixation.

Aged↗
PubMed2004

Mimicking protein-protein electron transfer: voltammetry of Pseudomonas aeruginosa azurin and the Thermus thermophilus Cu(A) domain at omega-derivatized self-assembled-monolayer gold electrodes.

Well-defined voltammetric responses of redox proteins with acidic-to-neutral pI values have been obtained on pure alkanethiol as well as on mixed self-assembled-monolayer (SAM) omega-derivatized alkanethiol/gold bead electrodes. Both azurin (P. aeruginosa) (pI = 5.6) and subunit II (Cu(A) domain) of ba(3)-type cytochrome c oxidase (T. thermophilus) (pI = 6.0) exhibit optimal voltammetric responses on 1:1 mixtures of [H(3)C(CH(2))(n)()SH + HO(CH(2))(n)()SH] SAMs. The electron transfer (ET) rate vs distance behavior of azurin and Cu(A) is independent of the omega-derivatized alkanethiol SAM headgroups. Strikingly, only wild-type azurin and mutants containing Trp48 give voltammetric responses: based on modeling, we suggest that electronic coupling with the SAM headgroup (H(3)C- and/or HO-) occurs at the Asn47 side chain carbonyl oxygen and that an Asn47-Cys112 hydrogen bond promotes intramolecular ET to the copper. Inspection of models also indicates that the Cu(A) domain of ba(3)-type cytochrome c oxidase is coupled to the SAM headgroup (H(3)C- and/or HO-) near the main chain carbonyl oxygen of Cys153 and that Phe88 (analogous to Trp143 in subunit II of cytochrome c oxidase from R. sphaeroides) is not involved in the dominant tunneling pathway. Our work suggests that hydrogen bonds from hydroxyl or other proton-donor groups to carbonyl oxygens potentially can facilitate intermolecular ET between physiological redox partners.

Azurin↗
PubMed2004

Comparative analysis of physical maps of four Bacillus subtilis (natto) genomes.

The complete SfiI and I-CeuI physical maps of four Bacillus subtilis (natto) strains, which were previously isolated as natto (fermented soybean) starters, were constructed to elucidate the genome structure. Not only the similarity in genome size and organization but also the microheterogeneity of the gene context was revealed. No large-scale genome rearrangements among the four strains were indicated by mapping of the genes, including 10 rRNA operons (rrn) and relevant genes required for natto production, to the loci corresponding to those of the B. subtilis strain Marburg 168. However, restriction fragment length polymorphism and the presence or absence of strain-specific DNA sequences, such as the prophages SP beta, skin element, and PBSX, as well as the insertion element IS4Bsu1, could be used to identify one of these strains as a Marburg type and the other three strains as natto types. The genome structure and gene heterogeneity were also consistent with the type of indigenous plasmids harbored by the strains.

Bacillus Phages↗
PubMed2004

[Low vision aids for reading in scar stage of age-related macular degeneration].

PURPOSE: To evaluate the inter-relationship among near visual acuity, eccentricity of preferred retinal locus(PRL), and choice of low vision aids for reading in patients with bilateral age-related macular degeneration(AMD). SUBJECTS AND METHODS: The preferred eye of 44 patients having bilateral disciform stage AMD was examined. The PRL was detected and its eccentricity from the fovea was measured by scanning laser ophthalmoscopic microperimetry. Magnification of a low vision aid for reading newsprint was determined by the critical print size which was calculated using the MNREAD-J. The type of preferred aid was chosen from high-plus lens glasses, magnifiers, and closed-circuit televisions. The inter-relationship among near visual acuity, eccentricity of the PRL, and magnification and type of low vision aid for reading were evaluated. RESULTS: The magnification of the aid was correlated with the eccentricity of PRL in eyes with near visual acuity of 0.2 or less although no correlation was found in eyes with near visual acuity better than 0.3. High plus lens glasses were selected by patients with near visual acuity better than 0.2 and eccentricity of 2 degrees or less. Magnifiers were selected by patients with near visual acuity better than 0.1 and eccentricity of 5 degrees or less. Closed-circuit televisions were selected by patients with near visual acuity of 0.1 or less and eccentricity of 5 degrees or more. CONCLUSION: The eccentricity of PRL should be taken into account in determining low vision aids for reading, especially in patients with near visual acuity of 0.2 or less. Choice of the type of low vision aid depends on not only near visual acuity but also on eccentricity of PRL.

Aged↗
PubMed2003

Stable positional cloning of long continuous DNA in the Bacillus subtilis genome vector.

Direct cloning of a long continuous genome segment in a Bacillus subtilis genome vector was demonstrated for the first time. Two small DNA fragments had to be installed in the vector prior to cloning. The DNA between these two fragments was cloned via homologous recombination. The efficiency of cloning was estimated using the 3,573-kb genome of a cyanobacterium, Synechocystis sp. PCC 6803. Recombinants were selected using the internal selection system of the Bacillus genome vector or with the antibiotic resistance marker in the cyanobacterial genome. Designated genomic segments as large as 77-kb were cloned by means of a single procedure. Cloning efficiency is affected by the molecular weight of the donor DNA and the size of the DNA to be cloned. The method is suitable for direct target cloning of large-sized DNA.

Bacillus subtilis↗
PubMed2003

Extracellular DNA and RNA produced by a marine photosynthetic bacterium Rhodovulum sulfidophilum.

A marine photosynthetic bacterium Rhodovulum sulfidophilum secretes nucleic acids that are involved in flocculating ability. These extracellular nucleic acids have not been well characterized. Here, we have analyzed these nucleic acids and revealed that the extracellular nucleic acids are a mixture of double-stranded DNAs and single-stranded RNAs. The DNAs have sizes of more than 30 kbp and at least a part of these DNAs is probably an amplified portion of genomic DNA. The RNAs seems to be tRNA like molecules from size estimation.

DNA, Bacterial↗
PubMed2003

[Preferred retinal locus in patients with age-related macular degeneration].

PURPOSE: To evaluate the status and location of the preferred retinal locus(PRL) and visual function in age-related macular degeneration(AMD). SUBJECTS AND METHODS: Thirty-five patients were examined. They were diagnosed as having bilateral AMD in the disciform stage. Scanning laser ophthalmoscopic microperimetry was performed to detect the PRL. The retinal conditions of the PRL were classified using color fundus photographs and fluorescein angiography. The eccentricities of PRL from the fovea were measured. The relationships among visual acuity, retinal sensitivity, and the eccentricities of the PRL were evaluated. RESULTS: In 34 of 35 eyes, PRLs had shifted from an extrafoveal site and were located at the nearest foveal site on the healthy retina or on an atrophic lesion of the retinal pigment epithelium. When it was possible that other lesions were located where the PRL had shifted to, the PRL moved to the upper or temporal retina. The eccentricities of PRLs were 0.5-11 degrees. Visual acuities differed among the same retinal eccentricities. CONCLUSIONS: PRLs shift to the lesion nearest the fovea. These results suggest that visual acuity and retinal sensitivity are determined by the status of the PRL.

Aged↗
PubMed2002

Screening and follow-up of diabetic retinopathy using a new mosaic 9-field fundus photography system.

AIM: To evaluate the clinical usefulness of a newly developed fundus photographing system and assess its applicability to telemedicine. METHODS: Nine overlapping 45 degrees fundus photographs were taken by a new camera equipped with nine internal fixation targets to provide standardized 9-field photographs. The digitally stored images were either edited in 3x3 form or reconstructed as collage (9F) and compared to the ophthalmological examination (OP) and single-field non-mydriatic photography (SC). In telemedicine, 9-field images derived from 61 adolescent diabetics were sent to ophthalmologists over an analog phone line. RESULTS: The sensitivities of the examinations by 9F without and with mydriasis (78 and 82%) were equivalent to OP (84%) and superior to SC (64%). The diagnosis of severity by 9F was also comparable to those by OP, whereas SC tended to underestimate the severity. An average of 1 min 19 s was required to send one edited 9-field photography (average size 259+/-30 KB) over the Internet. Twelve of these eyes were diagnosed as diabetic retinopathy on a desktop monitor whereas SC gave only seven. CONCLUSION: This new 9-field fundus photography system can be appropriate for the screening and follow-up of diabetic retinopathy in adult and adolescent diabetic subjects, especially when applied to telemedicine over the Internet.

Adolescent↗
PubMed2002

Patterning of human dental arch wire blanks using a vector quantization algorithm.

We objectively and automatically classified arch wire blank forms represented by a series of facial surface points on tooth crowns in human adults with normal occlusions using a vector quantization algorithm on the basis of the generalized Lloyd algorithm. We investigated also the descriptive dental arch form parameters that were most effective in distinguishing the classified groups of dental arch wire blanks and examined if they were associated with specific anatomical traits. Dental casts, taken from 79 adults with complete dentitions, were laser scanned with a computer-assisted stereotaxic device. Coordinates of the tooth crown points (FA points) were measured for each dental arch expressed as a vector having positional elements in a series of 14 FA points and categorized into several codes (ie, patterns) according to the similarity of the quantized vector patterns. We found that classifying the dental arches into four patterns maximized the difference between arch wire blank patterns. The classified patterns were differentiated by a gradual broadening of the interarch widths posterior to the lateral incisor. The code with the narrowest arch had the longest coronal arch, whereas the code with the widest arch had the shortest coronal arch (P < .01). The interpremolar and intermolar basal arch widths determined for the code showing the widest arch were significantly greater than those for the code with the narrowest width (P < .01).

Adult↗
PubMed2002

[Colchicine poisoning by accidental ingestion of the bulbs of Sandersonia aurantiaca: report of a case].

We report a case of colchicine poisoning in an 82-year-old woman. She had suffered from senile dementia and in her confused state ingested two bulbs of Sandersonia aurantiaca (Christmas-bells, Chinese lantern lily). She was admitted complaining of gastrointestinal symptoms, mainly severe watery diarrhea. The duration of her diarrhea was approximately 40 hours. On the 3rd day after ingestion, leukopenia and thrombocytopenia occurred. Although 50 micrograms of granulocyte-colony stimulating factor was administered from the 5th day to the 8th day, her white blood cell count did not increase and revealed nadir (100/microliter) on the 7th day. Her platelet count also revealed nadir on the 7th day. She died of respiratory failure in the early morning of the 9th day. The bulb of Sandersonia was found to contain colchicine at a concentration of 4.7 mg/g, and her serum level of colchicine was 6.3 ng/ml on the 6th day. Colchicine is an alkaroid extractable from the plants like Colchicum autumnale (meadow saffron, autumn crocus), and Gloriosa supra tuber. These plants belong to the lily family. Sandersonia aurantiaca also belongs to the lily family and we found that its bulb contained colchicine. To our knowledge, this is the first report of colchicine poisoning by Sandersonia aurantiaca.

Aged↗