Biomedical subjects

Yuji Murakami

Publications and source records attributed to Yuji Murakami.

14 recordsLinked to original sources

PubMed2006

CT appearance of radiation injury of the lung and clinical symptoms after stereotactic body radiation therapy (SBRT) for lung cancers: are patients with pulmonary emphysema also candidates for SBRT for lung cancers?

PURPOSE: The purpose of this study was to analyze the computed tomographic (CT) appearance of radiation injury to the lung and clinical symptoms after stereotactic body radiation therapy (SBRT) and evaluate the difference by the presence of pulmonary emphysema (PE) for small lung cancers. METHODS AND MATERIALS: In this analysis, 45 patients with 52 primary or metastatic lung cancers were enrolled. We evaluated the CT appearance of acute radiation pneumonitis (within 6 months) and radiation fibrosis (after 6 months) after SBRT. Clinical symptoms were evaluated by Common Terminology Criteria for Adverse Events, version 3.0. We also evaluated the relationship between CT appearance, clinical symptoms, and PE. RESULTS: CT appearance of acute radiation pneumonitis was classified as follows: (1) diffuse consolidation, 38.5%; (2) patchy consolidation and ground-glass opacities (GGO), 15.4%; (3) diffuse GGO, 11.5%; (4) patchy GGO, 2.0%; (5) no evidence of increasing density, 32.6%. CT appearance of radiation fibrosis was classified as follows: (1) modified conventional pattern, 61.5%; (2) mass-like pattern, 17.3%; (3) scar-like pattern, 21.2%. Patients who were diagnosed with more than Grade 2 pneumonitis showed significantly less no evidence of increased density pattern and scar-like pattern than any other pattern (p=0.0314, 0.0297, respectively). Significantly, most of these patients with no evidence of increased density pattern and scar-like pattern had PE (p=0.00038, 0.00044, respectively). CONCLUSION: Computed tomographic appearance after SBRT was classified into five patterns of acute radiation pneumonitis and three patterns of radiation fibrosis. Our results suggest that SBRT can be also safely performed even in patients with PE.

Aged↗

PubMed2006

Low viscous separation media for genomics and proteomics analysis on microchip electrophoresis system.

Microchip electrophoresis has widely grown during the past few years, and it has showed a significant result as a strong separation tool for genomic as well as proteomic researches. To enhance and expand the role of microchip electrophoresis, several studies have been proposed especially for the low viscous separation media, which is an important factor for the success of microchip with its narrow separation channels. In this paper we show an overview for the done researches in the field of low viscous media developed for the use in microchip electrophoresis. For genomic separation studies polyhydroxy additives have been used enhance the separation of DNA at low polymer concentration of HPMC (Hydroxypropylmethyl cellulose) which could keep the viscosity low. Mixtures of poly(ethylene oxide) as well as Hydroxyporpyl cellulose have been successfully introduced for chip separation. Furthermore high molecular mass polyacrylamides at low concentrations have been studied for DNA separation. A mixture of polymer nanoparticle with conventional polymers could show a better resolution for DNA at low concentration of the polymer. For the proteomic field isoelectric focusing on chip has been well overviewed since it is the most viscous separation media which is well used for the protein separation. The different types of isoelectric focusing such as the ampholyte-free type, the thermal type as well as the ampholyte-depended type have been introduced in this paper. Isoelectric focusing on chip with its combination with sodium dodecyl sulfate (SDS) page or free solution could give a better separation. Several application for this low viscous separation medias for either genomic or proteomic could clearly show the importance of this field.

Animals↗

PubMed2004

Reproducibility of organ position using voluntary breath-hold method with spirometer for extracranial stereotactic radiotherapy.

PURPOSE: To evaluate in healthy volunteers the reproducibility of organ position using a voluntary breath-hold method with a spirometer and the feasibility of this method for extracranial stereotactic radiotherapy in a clinical setting. METHODS AND MATERIALS: For this study, 5 healthy volunteers were enrolled. After training sessions, they held their breath at the end-inspiration and the end-expiration phase under spirometer-based monitoring. Computed tomography (CT) scans were performed twice at each respiratory phase, with a 10-min interval, on 2 separate days. The total number of CT scans was four at each respiratory phase. After CT volume data were transferred to a three-dimensional treatment-planning system, digitally reconstructed radiographs (DRRs) were calculated for anterior-posterior and left-right beams. Verification was performed with DRRs relative to the diaphragm position, bony landmarks, and the isocenter in each healthy volunteer at each respiratory phase. To evaluate intrafraction reproducibility, we measured the distance between diaphragm position and bony landmarks. To evaluate interfraction reproducibility, we measured the distance between diaphragm position and the isocenter. Reproducibility and setup error were defined as the average value of the differences between each DRR with regard to the first DRR. RESULTS: Intrafraction reproducibility of the caudal-cranial direction was 4.0 +/- 3.5 mm at the end-inspiration phase and 2.2 +/- 2.0 mm at the end-expiration phase. Interfraction reproducibility of the caudal-cranial direction was 5.1 +/- 4.8 mm at the end-inspiration phase and 2.1 +/- 1.8 mm at the end-expiration phase. The end-expiration phase was more stable than the end-inspiration phase. CONCLUSIONS: The voluntary breath-hold method with a spirometer is feasible, with relatively good reproducibility. We are encouraged about the use of this technique clinically for extracranial stereotactic radiotherapy.

Diaphragm↗

PubMed2004

Application of on-chip cell cultures for the detection of allergic response.

In this report, the development of a microfluidic cell chip for monitoring allergic response is described. A rat basophilic leukemia cell line (RBL-2H3), a tumor analog of rat mucosal mast cells, has been used as a model to observe its allergic response upon antigen stimulus. The cells were cultivated on a poly(dimethylsiloxane) (PDMS) chip, the surface of which was modified by several methods. The PDMS chip, which comprised a cell cultivation chamber and microfluidic channels, was fabricated by conventional molding methods. In order to detect the allergic response, a fluorescent dye, quinacrine, was introduced inside the cell compartment that included histamine. The cells were stimulated with dinitrophenylated bovine serum albumin (DNP-BSA) after incubation with anti-DNP IgE. When exocytosis events occurred, the microfluidic system detected the fluorescent signal of quinacrine, which was released from RBL-2H3 cells by using a photomultiplier tube (PMT) fitted onto a microscope.

Animals↗

PubMed2004

An early return to vigorous activity may destabilize anterior cruciate ligaments reconstructed with hamstring grafts.

OBJECTIVE: To evaluate the actual date of the return to activity and its impact on the postsurgical stability of anterior cruciate ligament reconstruction (ACLR) using hamstring grafts. DESIGN: A retrospective analysis. The time of return to activity was determined by a questionnaire at 24 to 36 months after ACLRs. SETTING: An orthopedic center. PARTICIPANTS: Fifty consecutive patients who had ACLRs using hamstring grafts 24 to 36 months earlier. INTERVENTIONS: Not applicable. Main outcome measure The time of return to activity from a questionnaire and serial KT-2000 data at 3, 6, 12, 18, and 24 months postsurgery. RESULTS: Patients were divided into 2 groups according to their KT-2000 side-to-side difference at 12, 18, and 24 months postsurgery. Group I consisted of patients whose differences were 3mm or less. Group II consisted of patients whose differences were more than 3mm. At 12 and 18 months postsurgery, significant differences were detected for the time of return to running and full-speed running. A multiple regression analysis for postsurgical stability at 24 months and the time of return to these 5 activities indicated that the time of return to full-speed running and sports activities had an effect on ACL stability. CONCLUSIONS: An early return to vigorous activities is not recommended in patients undergoing ACLRs with hamstring grafts.

Adolescent↗

PubMed2004

A picoliter chamber array for cell-free protein synthesis.

The completion of human genome sequencing has shifted the focus of research from genes to proteins. In this regard, a protein library chip has become a useful tool for cell-free protein synthesis. In this study, we attempted to make a highly-integrated protein chip from a DNA library using in vitro protein synthesis on a microchamber array fabricated by using PDMS (polydimethyl siloxane), a hydrophobic surface, and glass, a hydrophilic bottom substrate. These structural properties prevented cross-contamination among the chambers. The minimum volume capacity of the smallest chamber was about 1 pl. The total number of chambers per chip was 10,000 on one chip (capacity 150 pl) and 250,000 on two others (1 and 5 pl). Next, we attempted in vitro protein synthesis using this microchamber array. The fluorescence of Green Fluorescent Protein (GFP) expressed on the chamber was rapidly detected (within just 1 h). GFP expression was also successful using immobilized DNA molecules on polymer beads. DNA immobilized beads were added as the source to each microchamber. Protein was successfully synthesized from DNA immobilized beads, which allowed easy handling of the DNA molecules.

Cell-Free System↗

PubMed2004

[Concurrent chemoradiation using daily low-dose CDDP and UFT-E for postoperative recurrent esophageal cancers].

We reported concurrent chemoradiation for postoperative recurrent esophageal cancer patients with lymph node metastases and a pulmonary metastasis. From October 2001 to January 2004, we treated 6 consecutive patients with radiation and concurrent chemotherapy using daily low-doses of CDDP and UFT-E. Of the 6 patients, 4 (67%) had a complete response and 2 (33%) a partial response, yielding an overall response rate of 100% (6/6). Five patients are now alive without cancers, and 1 patient died with cancer. Concurrent chemoradiation using daily low-doses of CDDP and UFT-E is feasible and seems to offer good results for recurrent esophageal cancer patients.

Administration, Oral↗

PubMed2003

A rapid BOD sensing system using luminescent recombinants of Escherichia coli.

A biochemical oxygen demand (BOD) sensing system based on bacterial luminescence from recombinant Escherichia coli containing lux A-E genes from Vibrio fischeri has been developed. It was possible to use frozen cells of luminescent recombinants of E. coli as the bacterial reagents for measurement. Steady bioluminescence was observed during the incubation time between 90 and 150 min in the presence of a sole carbon source such as glucose, acetate, L-glutamate and BOD standard solution (GGA solution). This disposable bacterial reagent was applied to measure and detect organic pollution due to biodegradable substances in various wastewaters. The obtained values of this study showed a similar correlation with that of the conventional method for BOD determination (BOD5). Bacterial luminescence that was visualized with an imaging system using a charge coupled device (CCD) camera and a photomulti-counter demonstrated that this method could also be used for multi-sample detection of organic pollution due to biodegradable substances by using a microtiter plate. These results suggested for successful achievement of high-though-put detection of BOD in practical.

Biosensing Techniques↗

PubMed2003

Multianalyte immunoassay with self-assembled addressable microparticle array on a chip.

This paper describes the random fluidic self-assembly of metallic particles into addressable two-dimensional microarrays and the use of these arrays as a platform for constructing a biochip useful for bioassays. The basic units in the assembly were the microfabricated particles carrying a straightforward visible code and the corresponding array template patterned on a glass substrate. The particles consisted of a hydrophobic and magnetic Ni-polytetrafluoroethylene (PTFE) composite layer on one face, and on the other face a gold layer that was modified for biomolecular attachment. An array template was photoresist-patterned with spatially discrete microwells in which an electrodeposited Ni-PTFE hydrophobic composite layer and a hydrophobic photo-adhesive coating were deposited. The particles, after biomaterial attachment and binding processes in bulk, were self-assembled randomly onto the lubricated bonding sites on the chip substrate, driven by a combination of magnetic, hydrophobic, and capillary interactions. The encoding symbol carried by the particles was used as the signature for the identification of each target/assay attached to the particle surface. We demonstrate here the utility of microfabricated-encoded particle arrays for conducting multianalyte immunoassays in a parallel fashion with the use of imaging detection.

Biological Assay↗

PubMed2003

Anti-Saccharomyces cerevisiae antibodies in Japanese patients with inflammatory bowel disease: diagnostic accuracy and clinical value.

BACKGROUND: The diagnostic accuracy of the determination of anti- Saccharomyces cerevisiae antibodies (ASCA) and its clinical significance in Crohn's disease (CD) have been reported in Western countries, but scarcely reported in Japan, where the dietary habits of people differ markedly from those of Western countries. Th present study was undertaken to examine the diagnostic accuracy and clinical significance of ASCA determination in Japanese patients with CD or ulcerative colitis (UC). METHODS: Seventy-five serum samples obtained from 68 patients with CD, 34 serum samples obtained from 30 patients with UC, 35 serum samples from 35 patients with liver cirrhosis, and 31 serum samples from 31 healthy controls were examined. The optical density of each sample was measured by an enzyme-linked immunosorbent assay (ELISA) method to quantify ASCA IgA and IgG. RESULTS: The cutoff level, as determined by discriminant analysis of the data, was 0.1502 for ASCA IgA and 0.156 for ASCA IgG. Of the 68 patients with CD, 31 (45.6%) were ASCA-positive, and of the 30 patients with UC, 4 (13.3%) were ASCA-positive according to these cutoff levels. The sensitivity and specificity of ASCA determination for the differential diagnosis of CD from UC were 45.6% and 86.7%, respectively. When the relationship between ASCA and the clinical features of CD was analyzed, ASCA positivity was found to be correlated with duration of illness. CONCLUSIONS: The specificity of ASCA was high; however, the sensitivity was not. ASCA titers were generally low in the Japanese population examined. It would be desirable to determine cutoff levels for ASCA tailored to the Japanese people for the diagnosis of inflammatory bowel disease.

Adult↗

PubMed2003

Attachment of autogenous tendon graft to cortical bone is better than to cancellous bone: a mechanical and histological study of MCL reconstruction in rabbits.

We analyzed the mechanical and histological variables after the attachment of an autogenous tendon graft to cortical or cancellous bone. We reconstructed the medial collateral ligament of the knee in 33 Japanese white rabbits, using a bone socket procedure. The floor of the bone socket was cortical bone in group A and cancellous bone in group B. Mechanically, the pull-out test showed a tendency towards an increase in maximum failure load, with 10.9 N, 35 N and 37 N in group A, and 11 N, 18 N and 36 N in group B at 2, 4 (statistically significant difference) and 8 weeks after surgery, respectively. Histologically, the attachments were immature at 2 weeks. At 4 weeks, granulations had matured and Sharpey's fiber-like structures were seen. These fibers were more abundant in group A than in group B. At 8 weeks, the attachments in both groups were rather like the normal 4-zone structure. With time, tendon attachments matured in both groups. Our study showed that reattachment of tendons to cortical bone may be bettter than to cancellous bone.

Analysis of Variance↗

PubMed2003

Temporal changes in posterior laxity after isolated posterior cruciate ligament injury: 35 patients examined by stress radiography and MRI.

We examined the temporal changes in posterior laxity and MRI findings in acute isolated posterior cruciate ligament (PCL)-injured knees. 35 patients with acute isolated PCL injuries who attended our clinic within 10 weeks of an injury underwent nonoperative treatment, and were chronologically evaluated for posterior laxity and MRI. We divided them in 3 groups, as regards the evolution of laxity and MRI findings. In 20 patients, the degree of posterior laxity was slight throughout the observation periods. In 9 patients, who had severe posterior laxity on their initial visit, the laxity had improved markedly 6 months after injury and did not deteriorate. In 6 patients the severe posterior laxity did not improve during the study. 4 patients whose PCL on MRI was seen as a continuous swollen band having high signal intensity and showed consistently good stability or even an improvement. We conclude that acute isolated PCL injuries with a continuous swollen band on MRI should be treated conservatively for at least 6 months after injury, even if the posterior laxity is severe initially.

Adolescent↗

PubMed2003

[Concurrent chemoradiation experience of recurrent gastric cancers resistant to TS-1].

We report our experience with concurrent chemoradiation for recurrent gastric cancers resistant to TS-1. From April 2000 to March 2003, we treated 10 consecutive patients with radiation and the concurrent single chemotherapy agent of TS-1 or CPT-11. Of the 10 patients, 3 (30%) had a complete response, 4 (40%) a partial response, and 3 (30%) stable disease, yielding an overall response rate of 70% (7/10). Three patients are alive and cancer-free, 5 patients died with cancers, and 2 patients are living with cancers as outpatients. The clinical benefit response was 90% (9/10). No patient has had either acute or late complication. Concurrent chemoradiation is feasible and seems to offer good results for recurrent gastric cancers resistant to TS-1.

Aged↗

PubMed2002

Characterization of a new keratin-degrading bacterium isolated from deer fur.

A keratin-degrading bacterium was isolated from soil containing deer fur. An axenic culture of the keratin-degrading bacterium was obtained in liquid culture using a keratin enrichment technique. The isolated bacterium was gram negative and catalase- and oxidase-positive. Transmission electron microscopic observations showed that the bacterium was rod-shaped, 1.0-1.3 microm long and 0.7 microm in diameter. Phylogenetic analysis of 16S rDNA revealed that the new isolate has only 90.6% homology with Stenotrophomonas nitritireducens. Hence, this new bacterium was designated as Stenotrophomonas sp. D-1. The optimum temperature was determined to be 20 degrees C for maximum growth and keratinolytic enzyme production. Amino acid data, obtained after treating keratin powder with the supernatant culture, suggest that the major free amino acids resulting from keratin degradation are phenylalanine, tyrosine and valine. In addition, native chicken feather was degraded completely at 20 degrees C in 2.5 d by this bacterium.

Journal Article↗