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Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 37 records · Page 2Linked to original sources
PubMed2004

The effectiveness of a new multibending scope for endoscopic mucosal resection.

BACKGROUND AND STUDY AIMS: Each year at our institution we have been performing over 100 endoscopic mucosal resections (EMRs) for gastric tumor. However, there are some tumor locations where it is difficult to carry out this procedure, such as the lesser curvature or posterior wall of the gastric body, the cardia, and the lesser curvature of the antrum. To facilitate EMR of tumors in these locations, a multibending scope (the "M-scope", Olympus GIF-2T240M; Olympus Optical, Tokyo, Japan) has been developed, which has two independently curving segments. The aim of this study was to evaluate the effectiveness of this new multibending scope for EMR of gastric tumors. PATIENTS AND METHODS: Using the M-scope, we carried out EMR in 59 patients at the Jikei University Hospital. The lesions were located in the cardia in seven patients, in the gastric body in 30 patients, and in the antrum in 22 patients. The effectiveness of the M-scope was evaluated by experienced endoscopists; a score of 1 was given for very good effectiveness, and a score of 0 was given when there was no notable difference in effectiveness from the conventional scope. Evaluation was done according to the location of the lesions, the method used for EMR, and the tumor diameter. When the score for each item was equivalent to the average overall score for all the procedures or higher, the M-scope was defined as being effective. RESULTS: The overall score for all the procedures was 0.7 +/- 0.4 (average +/- SD) (very good in 43 procedures; no notable difference in 16 procedures). When assessed according to the location of the lesion, the mean effectiveness scores of the M-scope for lesions at the following locations were higher than the average overall score: the lesser curvature of the antrum (0.8 +/- 0.5); the posterior wall of the gastric body (1.0 +/- 0.0); the greater curvature of the gastric body (1.0 +/- 0.0); and the lesser curvature of the gastric body (0.9 +/- 0.4). The results suggested that the M-scope was effective for EMR of gastric tumors at these traditionally difficult locations. With regard to the scores assessed according to the method of EMR, the mean scores were 0.8 +/- 0.4 for the two-channel scope method and 0.9 +/- 0.4 for EMR using an insulated-tip diathermic knife (IT-EMR), again suggesting that the M-scope was effective for EMR by these methods. When evaluated according to tumor size, the score was 0.8 +/- 0.4 when the tumor was 11 mm or greater in diameter, indicating that the M-scope was effective for EMR of large tumors. CONCLUSION: The results of the study suggest that the M-scope is effective for EMR of tumors in the lesser curvature of the antrum, and in the posterior wall, lesser curvature, or greater curvature of the gastric body. With regard to the method of EMR, the M-scope is effective for both the two-channel scope method and IT-EMR. In relation to tumor size, the M-scope is effective for the resection of large tumors.

Adenoma↗
PubMed2004

Use of the curved linear-array echo endoscope to identify gastrorenal shunts in patients with gastric fundal varices.

BACKGROUND AND STUDY AIMS: : Balloon-occluded retrograde transvenous obliteration (B-RTO) has emerged as an effective, minimally invasive treatment for fundal varices. B-RTO requires a spontaneously developed gastrorenal shunt as a pathway for the balloon catheter to reach the fundal varices. We used a curved linear-array (CLA) echo endoscope in patients with fundal varices to identify gastrorenal shunts, and compared the detection rate with the gold standard, contrast-enhanced computed tomography (CECT). PATIENTS AND METHODS: A total of 40 patients with fundal varices were examined with both CLA echo endoscopy and CECT. The CECT images were retrospectively and independently evaluated by two gastroenterologists who were unaware of the clinical details, including the results of the CLA echo endoscopy. RESULTS: CLA echo endoscopy identified gastrorenal shunts in 26/40 patients with fundal varices. It visualized the shunt in a longitudinal direction and provided images of the connections of the shunt at both ends, the fundal varices and the left renal vein/branch of the inferior adrenal vein. The kappa index for CLA echo endoscopy and CECT for the identification of gastrorenal shunt was 0.9 (95 % CI, 0.6 to 1.0). When the cutoff point for the diameter of the gastrorenal shunt detected by the CLA echo endoscope was set at equal to or greater than 5 mm, the kappa index was 1.0 (95 % CI, 0.7 to 1.0). CONCLUSIONS: These results suggest that CLA echo endoscopy can successfully identify gastrorenal shunt and provide detailed morphological information. It also efficiently identifies patients suitable for B-RTO, particularly in cases of acute bleeding. It also has considerable potential for providing detailed information with regard to the treatment of gastric varices.

Adult↗
PubMed2004

Magnifying endoscopy combined with narrow band imaging system for early gastric cancer: correlation of vascular pattern with histopathology (including video).

BACKGROUND AND STUDY AIMS: The narrow band imaging (NBI) system consists of a sequential electronic endoscope system and a source of light equipped with new narrow band filters, yielding very clear images of microvessels on mucosal surfaces. The aim of this prospective study was to measure the correlation between the magnified images obtained with the NBI system and the histological findings, especially with regard to the vascular pattern. In addition, three-dimensional images of microvessels were reconstructed using a laser scanning microscope. PATIENTS AND METHODS: Between July 2001 and August 2003, 165 patients with depressed-type early gastric cancer lesions were enrolled in the study. The lesions were carefully observed with magnification using the NBI system. The images, the pathological characteristics of the lesions, and three-dimensionally reconstructed images of the microvascular networks in biopsied specimens were carefully analyzed. The microvascular patterns were classified into three groups: A, fine network; B, corkscrew; and C, unclassified pattern. The endoscopic images were compared with the histological findings. RESULTS: Of the three types of filter available for use with the NBI system, microvascular formation was best enhanced in B mode images produced using short wavelengths, which focus on the superficial mucosal layer. Among 109 cases of differentiated adenocarcinoma, the group A microvascular pattern was observed in 72 cases (66.1 %). Among 56 cases of undifferentiated adenocarcinoma, the group B pattern was observed in 48 cases (85.7 %; P = 0.0011) The microvascular structure observed using the NBI system corresponded with the superficial mucosal layer in the three-dimensional images obtained using laser scanning microscopy and the resected specimens. CONCLUSIONS: Magnifying endoscopy performed in combination with the NBI system is not sufficient to replace conventional histology, but is capable of predicting the histological characteristics of gastric cancer lesions.

Adenocarcinoma↗
PubMed2004

Relation between C reactive protein concentrations and coronary microvascular endothelial function.

OBJECTIVE: To determine how C reactive protein (CRP), a sensitive marker of inflammation, is related to coronary endothelial function. DESIGN: Changes in quantitative coronary angiographic findings and Doppler flow velocity measurements in response to locally infused acetylcholine were assessed. SETTING: Tertiary cardiology centre. PATIENTS: 46 patients with angiographically normal coronary arteries were divided into groups with normal (< or = 3 mg/l) or increased (> 3 mg/l) CRP concentrations. INTERVENTIONS: Acetylcholine (3 and 30 microg/min) was infused into the left coronary ostium for two minutes. MAIN OUTCOME MEASURES: Percentage change in diameter of epicardial coronary arteries and coronary blood flow (CBF) in response to acetylcholine; and correlations between these parameters and serum CRP concentrations. RESULTS: 15 patients had increased CRP concentrations. The change in coronary artery diameter induced by acetylcholine infusion was similar between the groups but the increase in CBF induced by acetylcholine was smaller in patients with increased CRP concentrations (54.9% v 139.4% with acetylcholine 30 microg/min, p = 0.0030). Multivariate analysis identified increased CRP concentration as independently associated with attenuated CBF response to acetylcholine at 30 microg/min (p = 0.0078, R2 = 0.434). CONCLUSIONS: These findings suggest that inflammation appears to be associated with impaired coronary endothelial function in resistance but not conduit vessels. The data suggest a close relation between chronic vascular inflammation and endothelial dysfunction in atherosclerosis.

Acetylcholine↗
PubMed2004

A case of systemic lupus erythematosus with giant hepatic cavernous hemangioma.

A 39-year old woman with antiphospholipid antibody positive systemic lupus erythematosus (SLE) was admitted to our department because of high fever, liver dysfunction and high level of C-reactive protein. At hospitalization, there was no anemia or jaundice. A tumor was palpable in the epigastric region, and there was tenderness in this region, but no muscular defense. There were no findings which indicated disease activity of SLE. The result of abdominal ultrasonography showed that there was a giant tumor, which occupied the majority of the left lobule of the liver, and a nonuniform ultrasound image was observed inside the tumor. The result of dynamic computed tomography (CT) showed peripheral globular enhancement, and enhancement then extended to the tumor center with time. Consequently, the patient was diagnosed with multiple hepatic hemangiomas. After admission, anemia rapidly deteriorated, and platelet count tended to decline. Therefore, intratumor hemorrhage was suspected, and emergent angiography was performed. For hemostatic purposes, transcatheter arterial embolization (TAE) and extended left hepatic lobectomy were performed. In patients with autoimmune diseases such as SLE and antiphospholipid syndromes, when thrombocytopenia is observed, care should be paid to identifying its cause, considering thrombocytopenia may be induced by hemangioma, although these cases are extremely rare.

Adult↗
PubMed2004

The vagus nerve is one route of transneural invasion for intranasally inoculated influenza a virus in mice.

Intranasally inoculated neurotropic influenza viruses in mice infect not only the respiratory tract but also the central nervous system (CNS), mainly the brain stem. Previous studies suggested that the route of invasion of virus into the CNS was via the peripheral nervous system, especially the vagus nerve. To evaluate the transvagal transmission of the virus, we intranasally inoculated unilaterally vagectomized mice with a virulent influenza virus (strain 24a5b) and examined the distribution of the viral protein and genome by immunohistochemistry and in situ hybridization over time. An asymmetric distribution of viral antigens was observed between vagal (nodose) ganglia: viral antigen was detected in the vagal ganglion of the vagectomized side 2 days later than in the vagal ganglion of the intact side. The virus was apparently transported from the respiratory mucosa to the CNS directly and decussately via the vagus nerve and centrifugally to the vagal ganglion of the vagectomized side. The results of this study, thus, demonstrate that neurotropic influenza virus travels to the CNS mainly via the vagus nerve.

Animals↗
PubMed2003

Persistence of viral RNA segments in the central nervous system of mice after recovery from acute influenza A virus infection.

One-hundred thirty-seven BALB/c mice were intranasally inoculated with neurotropic avian influenza A virus (H5N3). Thirty-nine of these mice died within 16 days post-inoculation (PID) and 98 of the mice recovered from the infection. To investigate whether viral antigens and genomes persist in the central nervous system (CNS) of recovered mice, immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) methods were performed. Histopathologically, mild interstitial pneumonia and non-suppurative encephalomyelitis restricted to the basal part of the frontal lobe of the cerebrum, brain stem and thoracic spinal cord were observed in BALB/c mice until 40 PID. Small amounts of viral antigens were detected in the brain and spinal cord and some viral RNA segments (NA, NP, M, PA, HA, NS, PB1) were intermittently detected in the CNS until 48 PID. Immunosuppression of these mice by dexamethazone (DEX) treatment did not increase the frequency of detection of the lesions, viral antigens or genomes. These findings suggest that viral genomes of neurovirulent influenza virus persist with restricted transcriptive activity in the CNS of the mice even after clinical recovery from the infection.

Animals↗
PubMed2003

Near-field optical mapping of exciton wave functions in a GaAs quantum dot.

Near-field photoluminescence imaging spectroscopy of naturally occurring GaAs quantum dots (QDs) is presented. We successfully mapped out center-of -mass wave functions of an exciton confined in a GaAs QD in real space due to the enhancement of spatial resolution up to 30 nm. As a consequence, we discovered that the spatial profile of the exciton emission, which reflects the shape of a monolayer-high island, differs from that of biexciton emission, due to different distributions of the polarization field for the exciton and biexciton recombinations. This novel technique can be extensively applied to wave function engineering in the design and the fabrication of quantum devices.

Journal Article↗
PubMed2003

Earlier surveillance colonoscopy programme improves survival in patients with ulcerative colitis associated colorectal cancer: results of a 23-year surveillance programme in the Japanese population.

Patients with long-standing ulcerative colitis (UC) are known to have an increased risk for the development of colorectal cancer (CRC). The aim of this study was to clarify the cumulative risk for the development of dysplasia or invasive cancer and the effectiveness of surveillance colonoscopy in the Japanese population. A total of 217 patients received a total of 1027 surveillance colonoscopies between January 1979 and December 2001 at the University of Tokyo hospital. Patients with invasive cancer found in the surveillance group were compared to those referred to our hospital from the other hospitals without surveillance colonoscopy. Surveillance colonoscopy confirmed 15 patients with definite dysplasia. Of these, five were proved to have invasive cancer in the resected specimens. The cumulative risk for the development of invasive cancer at 10, 20, and 30 years was 0.5, 4.1, and 6.1%, respectively, while that for the development of definite dysplasia at 10, 20, and 30 years was 3.1, 10.0, and 15.6%, respectively. All the patients with invasive cancer in the surveillance group remained alive, while three out of four patients in the nonsurveillance group died. Our surveillance programme is useful for detecting UC-associated CRC, and survival may be improved by surveillance colonoscopy.

Adolescent↗
PubMed2003

Reversible valence tautomerism induced by a single-shot laser pulse in a cobalt-iron Prussian blue analog.

Reversible valence tautomeric conversion induced by a single-shot laser pulse (8 ns duration) with a photon excitation energy of 2.38 eV has been observed in Na0.36Co1.32Fe(CN)(6).5.6H(2)O. A photoswitching process with accompanying magnetization and color changes was successfully achieved within the pulse duration at high temperature (above 200 K) in a thermal hysteresis loop. This unusual photoeffect originates from an optical charge transfer between Fe and Co atoms and evolves due to a cooperative interaction among the local photoexcited sites.

Journal Article↗
PubMed2003

Specific T-cell immunity against Ki-ras peptides in patients with pancreatic and colorectal cancers.

Mutations of codon 12 in the Ki-ras gene are frequently found in pancreatic and colorectal cancers. It has been demonstrated that human T-cells have the potential to recognise tumours expressing mutated ras-derived peptides. However, it remains unclear whether T-cells from a given individual can recognise the mutant peptides, which are expressed in that individual's tumour tissues. Mutations of the Ki-ras oncogene were analysed by the mutant-allele-specific amplification (MASA) method in pancreatic and colorectal tumour tissues, and T-cell responses against mutated Ki-ras-derived peptides were measured by [(3)H]thymidine incorporation and IFN-gamma production assays. Specific T-cell responses against Ki-ras-products were found in cancer patients, whereas no immune response was observed in normal individuals (P<0.01). Six of the eight pancreatic cancer patients (75%) and nine of 26 colorectal cancer patients (35%) had T-cell responses to mutated Ki-ras-derived-peptides. T-cell response in a given individual cannot recognise the same mutated ras peptide, which is expressed in that individual's tumour tissues. However, pancreatic and colorectal cancer patients have T-cell immunity against Ki-ras-peptides, and this provides potential target for cancer immunotherapy.

Cell Division↗
PubMed2003

Hyperresolving phase-only filters with an optically addressable liquid crystal spatial light modulator.

Hyperresolving (sometimes called 'superresolving' or 'ultraresolving') phase-only filters can be generated using an optically addressable liquid crystal spatial light modulator. This approach avoids the problems of low efficiency, and coupling between amplitude and phase modulation, that arise when using conventional liquid crystal modulators. When addressed by a programmed light intensity distribution, it allows filters to be changed rapidly to modify the response of a system or permit the investigation of different filter designs. In this paper we present experimental hyperresolved images obtained using an optically addressable parallel-aligned nematic LCD with two zone Toraldo type phase-only filters. The images are compared with theoretical predictions.

Diagnostic Imaging↗
PubMed2003

The allelic loss of chromosome 3p25 with c-myc gain is related to the development of clear-cell renal cell carcinoma.

To explore the role of allelic losses at 3p25 and genetic alterations of chromosome 8, we investigated the relationships between genetic alterations in these chromosomal regions and clinicopathologic findings (such as tumor size and grade), by employing fluorescence in situ hybridization (FISH). Fifty Japanese clear-cell renal cell carcinomas (RCCs) were examined by dual-color FISH using cosmid DNA probes for 3p25.1-25.3 combined with probes for chromosome 3 centromere, 8p12, 8p21.1, 8p21.3, 8p22 and 8q24.12-24.13 (c-myc), and chromosome 8 centromere. Deletion at 3p25.1-25.3 was detected in 38 patients (76%), while 8p12 deletion, 8p21.1 deletion, 8p21.3 deletion, 8p22 deletion and c-myc gain were detected in 23 (46%), 25 (50%), 25 (50%), 25 (50%), and 20 patients (40%), respectively. There was a significant correlation between 8p21.1 deletion, 8p21.3 deletion and 8p21.1 deletion with c-myc gain and tumor grade (p = 0.04, 0.04 and 0.02, respectively). Deletions at 8p21.1 and 8p21.3 with 3p deletion were significantly related to tumor grade; the statistical significance was identical to that of sole 8p deletion with tumor grade. The deletion at 3p25.1-25.3 with c-myc gain showed a significant correlation with tumor size, indicating an association with tumor progression. Our results suggest that the allelic loss of chromosome 3p25 with c-myc gain is related to the development of clear-cell RCC.

Carcinoma, Renal Cell↗
PubMed2003

Malignant retroperitoneal paraganglial tumour in a cow.

A large primary retroperitoneal sublumbar neoplasm was identified in an 11-year-old Holstein cow, with metastases to the lungs, kidneys and lymph nodes. The tumour cells proliferated in a characteristic endocrine pattern, were argyrophilic and positive for neuron-specific enolase, and had membrane-bounded intracytoplasmic granules. In addition, the cells were occasionally positive for cytokeratin and had desmosome-like intercellular junctions. The primary tumour mass was diagnosed as a malignant paraganglial tumour of the aortico-sympathetic ganglion (organ of Zuckerkandl), and was considered to contain primitive cells with epithelial differentiation.

Animals↗
PubMed2003

The role of chromosome 8p22 deletion for predicting disease progression and pathological staging in prostate cancer.

The natural course of human prostate cancer is highly variable, and we still lack reliable tools to predict the patient's outcome. Recent publications suggest that the deletion of chromosome 8p22 has an important role for tumor progression in prostate cancer. Totally, 97 patients (41 Japanese and 56 Swedish) were studied to detect the status of chromosome 8p22 deletion by the fluorescence in situ hybridization (FISH) technique. Seventy-seven underwent surgery (59 radical prostatectomies or 18 lymph node dissections), and the specimens were prepared by touch biopsy. Fine-needle aspiration biopsies (FNAB) were obtained from another non-operative 20 cases. Disease progression was evaluated in 57 patients with a median follow-up of 59 months. 8p22 deletions were detected in 58 (60 %) of all cases. The frequency of 8p22 deletion did not significantly differ between different preparations of specimens (touch biopsy vs. FNAB) as well as between different races (Japanese vs. Swedish). Cases with more than pT3 tumors had a significantly higher frequency of 8p22 deletion than those with pT2 (p < 0.01). Multivariate analysis demonstrated that 8p22 deletion was the strongest parameter to predict disease progression (hazard ratio = 5.75; p = 0.0001). Studies on chromosomal deletions of 8p22 by the FISH technique may serve as a universal genetic marker to optimize the treatment strategy in patients with prostate cancer.

Aged↗
PubMed2002

Retarded gastric acid secretion in rats infected with larval Taenia taeniaeformis.

The influence of hepatic larval Taenia taeniaeformis infection on gastric acid secretory activity and gastric mucosal integrity was investigated. After 12 weeks of infection with 2,000 T. taeniaeformis eggs, the gastric pH values of control and infected rats were 4.1+/-0.6 (mean +/- SD) and 8.4+/-0.2, respectively. There was no difference in the basal acid secretion between control (1.7+/-0.7 micro Eq.H(+)/15 min) and infected (1.9+/-0.3) rats. However, infected rats failed to respond to histamine stimulation, the maximum acid output level being 2.8+/-0.4 in the infected rats, compared to 12.9+/-3.3 in control rats. Larval T. taeniaeformis infection resulted in the suppression of gastric acid secretion leading to hypergastrinemia.

Animals↗
PubMed2002

A systematic review of stapled hemorrhoidectomy.

HYPOTHESIS: Use of circular stapled hemorrhoidectomy will result in the same or improved safety and efficacy outcomes as those of the conventional methods for hemorrhoidectomy in patients with hemorrhoids. DATA SOURCES: Studies on stapled hemorrhoidectomy were identified using PREMEDLINE and MEDLINE (June 1966-June 2001), EMBASE (January 1980-June 2001), Current Contents (June 1993-June 2001), Ovid HEALTHSTAR (January 1975-June 2001), the National Institutes of Health Clinical Trials database (searched June 13, 2001), and The National Coordinating Centre for Health Technology Assessment database (searched June 14, 2001). The search terms were as follows: haemorrhoid* and (stapl* or convent*) or hemorrhoid* and (stapl* or convent*). The Cochrane Library (2001, issue 2) was searched using the search terms haemorrhoid* or hemorrhoid*. STUDY SELECTION: Articles detailing randomized controlled trials were included if they compared circular stapled with conventional hemorrhoidectomy and provided relevant safety and efficacy outcome information. DATA EXTRACTION: Data from all included studies were extracted using standardized data extraction tables that were developed a priori. In addition, the randomized controlled trials were examined with respect to the adequacy of allocation concealment, handling of those unavailable for follow-up, and any other aspect of the study design or execution that may have introduced bias. DATA SYNTHESIS: Seven randomized controlled trials met the inclusion criteria. A meta-analysis was conducted when the studies had comparable outcomes, inclusion criteria, and follow-up. There was reasonably clear evidence in favor of the stapled procedure for bleeding at 2 weeks (relative risk, 0.55; 95% confidence interval, 0.37-0.82) and length of hospital stay (weighted mean difference, -0.89 days; 95% confidence interval, -1.42 to -0.36). Other less robust results in favor of the stapled hemorrhoidectomy related to pain, bleeding, anal discharge, wound healing, tenderness to per rectal examination, incontinence scores, earlier return of bowel function, analgesic requirement, and resumption of normal activities. One trial showed that prolapse occurred at significantly higher rates in the stapled hemorrhoidectomy group. However, the outcomes were poorly reported and generally showed statistically significant heterogeneity. CONCLUSIONS: Stapled hemorrhoidectomy may be at least as safe as conventional hemorrhoidal surgical techniques. However, the efficacy of the stapled procedure compared with the conventional techniques could not be determined. More rigorous studies with longer follow-up periods and larger sample sizes need to be conducted.

Hemorrhoids↗