Biomedical subjects

M Sato

Publications and source records attributed to M Sato.

At least 19 recordsLinked to original sources

PubMed2006

Ruptured intracranial aneurysm following gamma knife surgery for acoustic neuroma.

A-63-year-old woman underwent gamma knife surgery (GKS) for acoustic neuroma. Six years later, she suffered sudden onset of severe headache followed by a disturbance of consciousness and subarachnoid haemorrhage due to a ruptured aneurysm originating from the distal anterior inferior cerebellar artery. The aneurysm was not located at a branching site and was included within the radiation field. The aneurysm was treated by endovascular embolization, and now, 15 months later, the patient has recovered satisfactorily. This is the first report of aneurysm formation following GKS for acoustic neuroma.

Basilar Artery↗

PubMed2006

Antiremodeling agents influence osteoblast activity differently in modeling and remodeling sites of canine rib.

Antiremodeling agents reduce bone loss in part through direct actions on osteoclasts. Their effects on osteoblasts and bone formation activity are less clear and may differ at sites undergoing modeling vs. remodeling. Skeletally mature intact beagles, 1-2 years old at the start of the study, were treated daily with clinically relevant doses of alendronate (0.10 or 0.20 mg/kg), risedronate (0.05 or 0.10 mg/kg), raloxifene (0.50 mg/kg), or vehicle (1 mL/kg). Dynamic bone formation parameters were histologically assessed on periosteal, endocortical/trabecular, and intracortical bone envelopes of the rib. Raloxifene significantly increased periosteal surface mineral apposition rate (MAR), a measure of osteoblast activity, compared to all other treatments (+108 to +175%, P < 0.02), while having no significant effect on MAR at either the endocortical/trabecular or intracortical envelope. Alendronate (both 0.10 and 0.20 doses) and risedronate (only the 0.10 dose) significantly (P < or = 0.05) suppressed MAR on the endocortical/trabecular envelope, while none of the bisphosphonate doses significantly altered MAR at either the periosteal or intracortical envelopes compared to vehicle. Based on these results, we conclude that (1) at clinically relevant doses the two classes of antiremodeling agents, bisphosphonates and selective estrogen receptor modulators, exert differential effects on osteoblast activity in the canine rib and (2) this effect depends on whether modeling or remodeling is the predominant mechanism of bone formation.

Alendronate↗

PubMed2006

Genome-wide profiling of promoter methylation in human.

DNA methylation in the promoter region of a gene is associated with a loss of that gene's expression and plays an important role in gene silencing. The inactivation of tumor-suppressor genes by aberrant methylation in the promoter region is well recognized in carcinogenesis. However, there has been little study in this area when it comes to genome-wide profiling of the promoter methylation. Here, we developed a genome-wide profiling method called Microarray-based Integrated Analysis of Methylation by Isoschizomers to analyse the DNA methylation of promoter regions of 8091 human genes. With this method, resistance to both the methylation-sensitive restriction enzyme HpaII and the methylation-insensitive isoschizomer MspI was compared between samples by using a microarray with promoter regions of the 8091 genes. The reliability of the difference in HpaII resistance was judged using the difference in MspI resistance. We demonstrated the utility of this method by finding epigenetic mutations in cancer. Aberrant hypermethylation is known to inactivate tumour suppressor genes. Using this method, we found that frequency of the aberrant promoter hypermethylation in cancer is higher than previously hypothesized. Aberrant hypomethylation is known to induce activation of oncogenes in cancer. Genome-wide analysis of hypomethylated promoter sequences in cancer demonstrated low CG/GC ratio of these sequences, suggesting that CpG-poor genes are sensitive to demethylation activity in cancer.

Adenocarcinoma↗

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

Cloning and characterization of canine thyroglobulin complementary DNA.

Canine thyroglobulin (cTg) is one of the thyroid autoantigens associated with hypothyroidism caused by autoimmune thyroiditis in dog. To identify canine-specific areas in cTg, we cloned, by reverse transcriptase PCR, and sequenced the complete cDNA of cTg. It revealed an open reading frame of 8289 nucleotides, which encode a polypeptide of 2762 amino acids that is 78.9 and 78.1% identical to bovine and human thyroglobulin, respectively. This complete cTg sequence may be useful to promote the understanding of the primary structure of cTg and, it will be informative data in the further search about antigenic epitopes associated with autoimmune thyroiditis and pathogenesis of cTg-associated thyroid diseases in dog.

Amino Acid Sequence↗

PubMed2006

Admission blood glucose levels and early change of neurological grade in poor-grade patients with aneurysmal subarachnoid haemorrhage.

BACKGROUND: The neurological grade of poor-grade subarachnoid haemorrhage (SAH) often changes soon after the patient is admitted to the hospital. It is important to closely monitor for such changes within a short period of time after admission; however, there are other problems that can occur during this time such as rebleeding. The aim of this study was to evaluate the relationship between admission blood glucose levels (ABGL) and early change of neurological grade after admission in patients with poor-grade SAH. METHODS: Forty-six patients with poor-grade SAH (Hunt & Kosnik Grade IV or V), who were admitted within 3 hrs after SAH onset, and who did not have haematomas causing mass effect, or a history of diabetes mellitus, were included in the study. Patients were pretreated to control blood pressure and intracranial pressure, and they were monitored for early change of grade after admission. Blood glucose level was measured at the time of admission. FINDINGS: Spontaneous grade improvement was observed in 9 of 17 Grade IV patients and 9 of 29 Grade V patients. The ABGL of the patients with grade improvement were significantly lower than the ABGL of the patients who did not improve or who got worse. ABGL were lower than 180 mg/dl in 15 of 18 patients who showed grade improvement. CONCLUSIONS: Our results showed that there was a relationship between ABGL and neurological grade changes which were observed after admission in patients with poor-grade SAH. These results suggest that ABGL might be a useful parameter for making therapeutic decisions.

Adult↗

PubMed2006

Brachytherapy technique for abdominal wall metastases of colorectal cancer: ultrasound-guided insertion of applicator needle and a skin preservation method.

PURPOSE: To report a technique of interstitial brachytherapy for the treatment of subcutaneous metastatic abdominal wall tumors. MATERIAL AND METHODS: We developed a brachytherapy technique consisting of ultrasound-guided insertion of applicator needles to avoid the organs at risk, such as intestines, and saline injection into the subcutaneous tissue between the tumor and the skin to decrease the skin dose. We encountered three patients with painful metastases from rectal carcinoma in the abdominal wall refractory to external radiotherapy. They were subjected to this brachytherapy with a single dose of 20 Gy. RESULTS: The procedure was safely achieved in all three patients. Long-lasting pain reduction and tumor shrinkage was obtained without early or late complications. CONCLUSION: This interstitial brachytherapy technique seems to be feasible in the treatment of metastatic abdominal wall tumors.

Abdominal Neoplasms↗

PubMed2006

Cloning and characterization of the homologous genes of firefly luciferase in the mealworm beetle, Tenebrio molitor.

Three homologous genes of firefly luciferase were cloned from the non-luminous beetle Tenebrio molitor. Three gene products for homologues, TmLL-1, TmLL-2 and TmLL-3, showed fatty acyl-coenzyme A (acyl-CoA) synthetic activity, but not luciferase activity with firefly luciferin. The transcripts were detected through the developmental stages in T. molitor. These results suggested that firefly luciferase was evolved from a fatty acyl-coenzyme A synthetase by gene duplications in the insect.

Amino Acid Sequence↗

PubMed2006

Preliminary study on the effect of oral care on recovery from surgery in elderly patients.

This study aimed to clarify the effectiveness of post-operative oral care, including tooth brushing, denture cleaning and tongue cleaning, after digestive tract surgery. Subjects included 30 elderly patients aged 60-98 years (74.9 +/- 7.8 years) who underwent digestive tract surgery. Subjects were randomly divided into an intervention group and a control group. In the intervention group, the following oral care was provided daily over a 5-min period in the morning starting at baseline (day of surgery) and continued for 5 days: gargling with povidone iodine, tooth brushing, denture cleaning using a special brush and tongue cleaning using a tongue brush. In the control group, the subjects only gargled with povidone iodine. We compared the following variables between the two groups at baseline and 5 days later: the sensation of dry mouth, intra-oral gas concentration, pulmonary sounds, body temperature and bacterial flora. The number of patients with abnormal pulmonary sounds (dry or moist rales) increased from 1 to 2 in the intervention group and from 0 to 4 in the control group (P < 0.05). The average number of bacterial species per subject for the control group was 3.64 +/- 1.34 pre-operatively and 3.50 +/- 1.74 post-operatively, whereas that for the intervention group was 3.08 +/- 0.95 pre-operatively and 2.62 +/- 0.65 post-operatively. In the intervention group, there was a significant decrease in the number of bacterial species (P < 0.05). These findings indicate that post-operative oral care in elderly patients undergoing digestive tract surgery lowers the number of bacterial species found in the oral cavity. This effect, in turn, might improve respiratory function.

Aged↗

PubMed2006

Asaccharolytic anaerobic gram-negative coccobacilli (AAGNC) isolated from infected root canals and periodontal pockets.

BACKGROUND/AIMS: Culture-difficult bacteria, including asaccharolytic anaerobic gram-negative coccobacilli (AAGNC), may constitute a predominant group of organisms in oral sites. This study aimed to characterize phylogenetically 10 AAGNC isolated from endodontic lesions and periodontal pockets. METHODS: 16S rDNA sequence and G + C content were determined. Strains sharing more than 98% sequence similarities and similar G + C content were considered the same bacterial species. RESULTS: One isolate resembled Dialister pneumosintes (the type species of the genus Dialister) with 35 mol% G + C content and 97% sequence similarity. Of eight isolates having 45-47 mol% G + C content, seven were identified as D. invisus and one resembled Dialister invisus with 97% sequence similarity. However the 16S rDNA sequence similarities with D. pneumosintes were relatively low, indicating the strains may belong to a new genus. The last isolate revealed 35 mol% G + C content, but had higher 16S rDNA sequence similarity with D. invisus than with D. pneumosintes. CONCLUSION: The group of oral AAGNC isolates need to be reclassified.

Base Composition↗

PubMed2006

Different antibacterial actions of isoflavones isolated from Erythrina poeppigiana against methicillin-resistant Staphylococcus aureus.

AIMS: To screen six isoflavones isolated from Erythrina poeppigiana (Leguminosae) for their antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: Stem bark of E. poeppigiana was macerated with acetone and the methylene chloride-soluble fraction of the residue was applied to repeated silica gel column chromatography and eluted. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by a broth dilution method. Inactive compounds that failed inhibiting bacterial growth at 25 microg ml(-1) were further investigated for their combination effects with methicillin and oxacillin. Of the isolated isoflavones, 5,7,4'-trihydroxy-8,3'-di(gamma,gamma-dimethylallyl)isoflavone (isolupalbigenin) exhibited the highest anti-MRSA activity (MICs: 1.56-3.13 microg ml(-1); MBCs: 6.25-12.5 microg ml(-1)), followed by 5,7,4'-trihydroxy-6-gamma,gamma-dimethylallylisoflavone (erythrinin B). Inactive compounds were combined with methicillin or oxacillin, 5,4'-dihydroxy-(3'',4''-dihydro-3''-hydroxy)-2'',2''-dimethylpyrano[5'',6'':6,7]isoflavone (M-Wi-2) intensifying the susceptibility of MRSA strains to these antibiotics. In all but one strain, the MIC values of methicillin were reduced from > or =100 to 6.25-12.5 microg ml(-1) in the presence of M-Wi-2 (25 microg ml(-1)). CONCLUSIONS: Isoflavones from E. poeppigiana showed two different antibacterial activities against MRSA: direct growth inhibition and intensification of methicillin sensitivity. SIGNIFICANCE AND IMPACT OF THE STUDY: Isolupalbigenin and M-Wi-2 could lead to the development of compounds for new approaches against MRSA infection.

Acetone↗

PubMed2006

Immunohistopathological study of the oral lichenoid lesions of chronic GVHD.

BACKGROUND: Chronic graft-vs.-host disease (cGVHD) is a common and serious complication after bone marrow transplantation (BMT). However, the detailed process of oral lichenoid lesions of cGVHD is still unknown. Therefore, we investigated the immunohistopathological features of cGVHD compared with oral lichen planus (OLP) and healthy controls. METHODS: Nineteen allogenic BMT recipients with a histopathological diagnosis of cGVHD were investigated. We investigated the immunohistopathological features of cGVHD compared with OLP and healthy controls. RESULTS: Immunohistopathological features showed that the infiltrations of CD4-positive T cells of cGVHD and OLP were significantly larger than those of the normal oral mucosa (P < 0.005). A larger number of CD8-positive T cells was infiltrated in cGVHD and OLP compared with the normal oral mucosa (P < 0.001). The difference in the number of CD4- and CD8-positive T cells between cGVHD and OLP was not significant. The infiltrations of Langerhans cells (CD1a) in cGVHD and OLP were significantly larger than those in the normal oral mucosa (P < 0.005). The difference in the number of Langerhans cells between cGVHD and OLP was not significant. CD68-positive macrophages were more frequently seen in cGVHD and OLP than in the normal oral mucosa (P < 0.0001). The difference in the number of CD68-positive macrophages between cGVHD and OLP was not significant. CONCLUSIONS: It is suggested that Langerhans cells and CD8-positive T cell may play a major role in the pathogenesis of the oral lichenoid lesions of cGVHD, and the immune response was inducted in OLP as well as the oral lichenoid lesion of cGVHD in this study.

Antigens, CD↗

PubMed2006

Retention and removal of a new viscous dispersive ophthalmic viscosurgical device during cataract surgery in animal eyes.

AIMS: To assess the retention and removal properties of a new viscous dispersive ophthalmic viscosurgical device (OVD), DisCoVisc, in comparison with those of cohesive (Provisc), dispersive (Viscoat), and viscoadaptive (Healon5) OVDs. METHODS: In 20 porcine eyes, cataract surgery was simulated using one of the four OVDs which were stained with fluorescein for better visualisation. Three parameters were measured. Firstly, the presence/absence of OVDs in the chamber at the completion of phacoemulsification was recorded. Secondly, the time until the OVDs were completely removed from the anterior chamber using the phaco needle was measured. Thirdly, after intraocular lens (IOL) implantation, the time needed to completely remove the OVDs from the chamber with irrigation/aspiration tip was recorded. RESULTS: At the completion of phacoemulsification, the OVDs retained in 0% (0/5) for Provisc, 80% (4/5) for Healon5, 100% (5/5) for DisCoVisc, and 100% (5/5) for Viscoat. The retention of OVDs during phacoemulsification was greatest with Viscoat followed by, in descending order, DisCoVisc, Healon5, and Provisc. The removal of OVDs after IOL implantation took longest with Viscoat followed by Healon5, DisCoVisc, and Provisc. CONCLUSION: The viscous dispersive DisCoVisc showed excellent retention during phacoemulsification, while its removal after IOL implantation was very easy. When compared with the viscoadaptive Healon5, DisCoVisc was retained better in the chamber and was easier to remove. These features of DisCoVisc should be highly advantageous when considering covering the entire cataract surgery procedure with a single OVD.

Animals↗

PubMed2006

A cross-cultural survey of residents' perceived barriers in questioning/challenging authority.

OBJECTIVES: To identify perceived barriers to residents' questioning or challenging their seniors, to determine how these barriers affect decisions, and to assess how these barriers differ across cultures. METHOD: A written questionnaire was administered to residents in teaching hospitals in the US and Japan to assess factors affecting residents' willingness to question or challenge their superiors. The responses were analyzed for statistical significance of differences between the two cultures and to determine the importance of issues affecting decisions. RESULTS: Questionnaires were completed by 175 US and 65 Japanese residents, with an overall response rate of 71%. Trainees from both countries believe that questioning and challenging contribute to safety. The perceived importance of specific beliefs about the workplace differed across cultures in seven out of 22 questions. Residents' decisions to make a challenge were related to the relationships and perceived response of the superiors. There was no statistical difference between the US and Japanese residents in terms of the threshold for challenging their seniors. CONCLUSION: We have identified attributes of residents' beliefs of communication, including several cross-cultural differences in the importance of values and issues affecting one's decision to question or challenge. In contrast, there was no difference in the threshold for challenging seniors by the Japanese and US residents studied. Changes in organizational and professional culture may be as important, if not more so, than national culture to encourage "speaking up". Residents should be encouraged to overcome barriers to challenging, and training programs should foster improved relationships and communication between trainers and trainees.

Attitude of Health Personnel↗

PubMed2006

Usefulness of mini-tracheostomy and torque controlled insertion of applicator in fractionated endobronchial brachytherapy.

Endobronchial brachytherapy was developed as effective treatment of endobronchial cancer and fractionated schedule is applied to decrease late toxicity. However, repeated bronchofiberscopy is onerous to the patient and restricts the treatment schedule itself. We applied mini-tracheostomy for a ready access route, and a torque controlled technique for easy insertion of the endobronchial applicator. Eight patients with tracheobronchial cancer invasion were treated with endobronchial brachytherapy of 18-30 Gy/3-5 fractions/1.5-2.5 weeks (median 24 Gy/4 fractions/2 weeks) at reference points of 5 mm from the bronchial surface. The averaged individual irradiation and single session times were 4 min and 24 min, respectively. There were no procedure-related complications. These technical improvements may facilitate flexible fractionated dose prescriptions.

Aged↗

PubMed2006

Effect of different dialyzer membranes on cutaneous microcirculation during hemodialysis.

AIM: Biocompatibility profiles of synthetic membranes may vary. In this prospective crossover study, we examined the effect of various membranes on cutaneous microcirculation during HD. SUBJECTS AND METHODS: 11 HD patients without cardiovascular complications were enrolled in this study. They were dialyzed using three types of membrane in a randomized order: ethylene-vinyl alcohol copolymer (EVAL), vitamin E-bonded cellulose (VE-C) and polysulfone (PS). The transcutaneous oxygen tension (TcPO2) was examined on the dorsum of foot to assess the cutaneous microcirculation. Serum biochemical parameters were also measured. RESULTS: The TcPO2 as a percentage of the predialysis level decreased from the beginning of HD, and significant differences were observed after 15 min of HD between EVAL and the other 2 membranes (98 +/- 6% (mean +/- SD) for EVAL versus 89 +/- 7% for VE-C (p < 0.01) and 88 +/- 10% for PS (p < 0.01)). Furthermore, there were significant differences at 30 and 60 min between EVAL and PS (30 min: 93 +/- 9% for EVAL versus 85 +/- 7% for PS (p < 0.05); 60 min: 92 +/- 10% for EVAL versus 79 +/- 10% for PS (p < 0.01)). The serum level of thiobarbituric acid reactants (TBARs), a marker of lipid peroxidation, increased significantly at the end of HD relative to that at the beginning of HD when using a PS membrane (from 1.9 +/- 0.5 to 2.1 +/- 0.5 nmol/ml, p < 0.05). CONCLUSION: Our results indicate that an EVAL membrane is superior to PS and VE-C membranes in terms of its smaller influence on cutaneous microcirculation. The repeated occurrence of microcirculatory disturbance during HD sessions may cause chronic endothelial dysfunction and even cardiovascular complications in HD patients.

Adult↗

PubMed2006

False aneurysm formation at proximal and distal ends of a stent graft: a rare complication in the repair of endovascular thoracic aortic aneurysm.

This case report demonstrates a rare complication of false aneurysm formation at the proximal and distal ends of a stent graft that was placed in the descending thoracic aorta to repair an atherosclerotic aneurysm with a fibrotic, solid aortic wall. This complication can develop not only in penetrating aortic ulcers and aortic dissections but also in atherosclerotic aneurysms.

Aged↗

PubMed2005

Controlled switching of intrinsic localized modes in a one-dimensional antiferromagnet.

Nearly-steady-state locked intrinsic localized modes (ILMs) in the quasi-1D antiferromagnet (C(2)H(5)NH(3))(2)CuCl(4) are detected via four-wave mixing emission or the uniform mode absorption. Exploiting the long-time stability of these locked ILMs, repeatable nonlinear switching is observed by varying the sample temperature, and localized modes with various amplitudes are created by modulation of the microwave driver power. This steady-state ILM locking technique could be used to produce energy localization in other atomic lattices.

Journal Article↗