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Biomedical subjects

M Matsumura

Publications and source records attributed to M Matsumura.

At least 19 recordsLinked to original sources

Gastric cancer among peptic ulcer patients: retrospective, long-term follow-up.

BACKGROUND: Patients with duodenal ulcer are not at high risk although Helicobacter pylori infection is no doubt associated with gastric cancer development. However, little is known about the risk after long-term follow-up. AIMS: We investigated the incidence for gastric cancer development in peptic ulcer patients in a long term. PATIENTS AND METHODS: Between 1965 and 2004, endoscopic follow-up of more than 1 year was conducted on 1504 peptic ulcer patients in our hospital. They consisted of 978 gastric ulcer patients, 444 duodenal ulcer patients and 82 gastric and duodenal ulcer patients. Gastric and duodenal ulcer patients were excluded from the analysis because of their limited number. RESULTS: Gastric cancers developed in 32 (3.3%) of gastric ulcer patients and 3 (0.68%) of duodenal ulcer patients. Kaplan-Meier analysis showed that the incidence of gastric cancer in duodenal ulcer patients was significantly lower than that in gastric ulcer patients (log-rank test, p=0.0059). Cox's proportional hazard model denoted the relative risk for duodenal ulcer against gastric ulcer adjusted by sex and age as 0.23 (95% CI: 0.072-0.77, p=0.016). CONCLUSION: The risk for patients with duodenal ulcer to develop gastric cancer over the long term is significantly less than in those with gastric ulcer.

Duodenal Ulcer↗

Study on the relationship of protease production and luminescence in Vibrio harveyi.

AIMS: To demonstrate that Vibrio harveyi produces various types of toxins and how the production of those toxins is related with luminescence. METHODS AND RESULTS: Luminescence and toxicity of eight V. harveyi were evaluated. We demonstrated that all V. harveyi emitting luminescence were isolated from marine organisms and also showed that they were highly pathogenic when compared with culture collection V. harveyi based on cytotoxic assay test. On the contrary, V. harveyi isolated from shrimp farm showed no luminescence but showed high pathogenicity based on toxicity test. The effect of protease inhibitors on pathogenicity and luminescence was also investigated. We demonstrated that light emission of pathogenic V. harveyi remarkably decreased after addition of protease inhibitor. Furthermore, extracellular proteins from cell-free culture supernatant of luminescent and nonluminescent V. harveyi were compared using SDS-PAGE analysis. Results showed that there were differences in molecular weight and amount of proteins. CONCLUSIONS: Vibrio harveyi parasiting marine organisms have both luminescence and pathogenicity. Based on this study, luminescence and protease toxin activity in V. harveyi are related. Moreover, this paper clarified that V. harveyi produces various types of toxins. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study demonstrated that V. harveyi produces two kinds of toxins, haemolysin and protease toxin. It may be clear roots of V. harveyi toxin.

Bacterial Proteins↗

[Unusual total anomalous pulmonary venous connection; report of a case].

We report a case of a 7-hour-old infant with total anomalous pulmonary venous connection having abberant origin of the vertical vein. His clinical condition presented hemodynamically severe pulmonary vein obstruction as common pulmonary vein atresia. Without making the definitive diagnosis, he underwent the operation at 11 hours after birth under cardiopulmonary bypass. During the operation, we could not identify the drainage vein. Although we ligated the vessel sized less than 2 mm in diameter draining into superior vena cava which was suspected to be the vertical vein. After the operation pulmonary edema was severe, but his clinical condition improved by using nitric oxide without extracorporeal membrane oxygenation (ECMO) support. Postoperative cardiac catheterization showed normal cardiac function without pulmonary venous obstruction, and moreover identified the drainage vein originated from right upper pulmonary vein. To the best of our knowledge, this is the first case where the vertical vein originated from right upper pulmonary vein. Immediate surgical treatment before the circuratory exacerbation improve the outcome for this congenital anomaly.

Humans↗

Retinal neovascularisation without ischaemia in the spontaneously diabetic Torii rat.

AIMS/HYPOTHESIS: The spontaneously diabetic Torii (SDT) rat has recently been established as a model of type 2 human diabetes mellitus. Male SDT rats develop severe diabetic ocular complications. This study investigated the nature of the ocular complications in this model and addressed the question of whether the SDT rat is a good model of human proliferative diabetic retinopathy. METHODS: Male SDT rats aged 50 weeks were studied for a period of 8 months. Under deep anaesthesia, one eye of each animal was enucleated following perfusion with fluorescein dextran and a retinal flat mount was prepared to study vascular structure. The other eye was enucleated and investigated histologically by haematoxylin-eosin and azan staining and by immunohistochemistry using antibodies against vascular endothelium (Griffonia simplicifolia isolectin B4 antibody) and vascular endothelial growth factor (VEGF). RESULTS: From the vascular structure study, 17 of 32 rats (53%) showed proliferative retinopathy without vascular non-perfusion. The histological study revealed traction retinal folds in rats with proliferative retinopathy. Azan staining showed some proliferative matrix in rats with normal retinal structure and those with proliferative retinopathy compared with normoglycaemic controls. Staining with Griffonia simplicifolia isolectin B4 antibody showed no specific vascular changes in any of the rats, while VEGF staining revealed higher immunoreactivity in the retina of rats with normal retinal structure and those with proliferative retinopathy, but only low immunoreactivity in the control animals. CONCLUSIONS/INTERPRETATION: There appear to be differences between the SDT rat model of diabetic retinopathy and human proliferative diabetic retinopathy, as the SDT rat develops retinal neovascularisation without retinal ischaemia. This very unique display of ocular neovascularisation may be caused by increased expression of VEGF.

Animals↗

Optic nerve compression by normal carotid artery in patients with normal tension glaucoma.

AIM: To determine whether compression of the optic nerve by the intracranial carotid artery (ICA) can be a causative factor of normal tension glaucoma (NTG). METHODS: The medical records of 103 eyes of 54 Japanese patients with NTG and 104 eyes of 52 age matched control patients were reviewed. The neuroradiological findings of magnetic resonance images (MRI) were evaluated to determine the relation between the optic nerve and ICA. The clinical characteristics and general medical conditions, such as diabetes and systemic hypertension, were also compared between the two groups. RESULTS: The prevalence of optic nerve compression by the ICA in patients with NTG was 49.5%, which was significantly higher than that in control group with 34.6% (p = 0.035). Bilateral compression of the optic nerve was detected in 22 patients with NTG (40.7%), and this was also significantly higher (p = 0.029) than that in the control group (11 patients, 21.2%). In the NTG group, eyes with cup/disc ratio (C/D ratio) > or =0.7 showed a higher percentage of compression (52.6%) compared with eyes with C/D ratio of <0.7 (12.5%; p = 0. 042). The presence of diabetes and hypertension did not affect the incidence of optic nerve compression by ICA significantly. CONCLUSIONS: The significantly higher percentage of NTG patients who had optic nerve compression by the ICA suggests that compression of the optic nerve by ICA may be a possible causative factor or a risk factor for optic nerve damage in some patients with NTG.

Adult↗

Improved simultaneous nitrification and denitrification in a single reactor by using two different immobilization carriers with specific oxygen transfer characteristics.

To maximize nitrogen utilization rates during nitrification and denitrification in a simultaneous reaction for direct nitrogen removal from ammonia-nitrogen in a single reactor, two different carriers were applied that immobilized nitrifiers and denitrifiers separately. With the optimized DO concentration and mixing ratio of immobilization carriers, ammonium-nitrogen was successfully removed as designed until the middle phase of treatment where nitrogen removal rate was higher than 83% of the theoretical value, although an imbalance between nitrification and denitrification occurred at a later phase of treatment where residual nitrate-nitrogen concentration was less than 2 mg/l. The new approach using two different carriers to immobilize nitrifiers and denitrifiers separately was proved useful for controlling both nitrification and denitrification rates, enabling the utilization of maximum treatment ability of both nitrifiers and denitrifiers in a single reactor for direct nitrogen removal from ammonium-nitrogen.

Acrylic Resins↗

Comparative analysis of genetic diversity and expression of amoA in wastewater treatment processes.

The genetic diversity and expression of amoA of autotrophic ammonia oxidizers in wastewater treatment processes were investigated by RT-PCR and denaturing gradient gel electrophoresis (DGGE) in order to identify active components of ammonia-oxidizer populations in a such processes. Ammonia oxidizers, evidenced by the presence of amoA mRNA, were regarded as metabolically active. The DGGE profiles derived from amoA mRNA and from its gene, which were amplified by RT-PCR or PCR using samples collected from a bench-scale reactor treating high concentration of inorganic ammonia, were similar. In contrast, RNA and DNA-derived DGGE profiles from three domestic wastewater treatment facilities were different from each other. These data indicate that the dominant ammonia oxidizers in the bench-scale reactor exhibited ammonia-oxidizing activity, whereas some ammonia oxidizers in the domestic wastewater treatment facilities apparently did not express high levels of amoA mRNA.

Ammonia↗

Effects of FTY720 on rat lymphoid organs.

INTRODUCTION: In this study, we examined the in vivo effect of FTY720 on rat thymus and spleen. MATERIALS AND METHODS: Inbred male Lewis (RT-I(l)) rats, 5-weeks-old, received FTY720 (0.1, 1, or 10 mg/kg) by intramuscular injection into 1 of 4 limbs daily for 7 days. The rats were humanely killed at 1, 3, 5, or 7 days after starting administration of FTY720. The thymus and spleen were obtained for hematoxylin and eosin (HE) as well as immunoperoxidase staining using the antibodies OX8 (CD8), W3/25 (CD4), and OX6 (major histocompatibility complex class II). RESULTS: HE staining revealed marked atrophy in the cortical region of the thymus among rats administered FTY720 at the dose of 10 mg/kg. The atrophy extended to the whole cortex. On day 7 of administration of FTY 720 (10 mg/kg), the medulla of the thymus showed relative expansion due to cells accumulation. Also, the spleens of FTY720-treated rats revealed an obvious reduction in the T-cell-dependent areas around the central artery. In conclusion, the immunosuppressive effect of FTY720 may be due to an inhibitory effect on T-cell emigration from the thymus to the periphery.

Animals↗

Two cases of recurrent IgA nephropathy following kidney transplantation.

Recurrence of immunoglobulin (Ig) A nephropathy following kidney transplantation has been described as occurring in 40% to 60% of cases. Although this type of recurrence was considered a benign condition for a long time, more recent data showed that recurrent transplant IgA nephropathy may be a significant contributor to graft loss. We present 2 cases of recurrent IgA nephropathy following kidney transplantation. In case 1, renal function remained stable with a creatinine level of 1.2 mg/dL at 5 months after diagnosis and 61 months after transplantation. In case 2, the patient lost his graft and returned to regular hemodialysis at 36 months after diagnosis and 125 months after kidney transplantation.

Adult↗

Expression of pigment epithelium derived factor and vascular endothelial growth factor in choroidal neovascular membranes and polypoidal choroidal vasculopathy.

AIMS: To determine whether pigment epithelium derived factor (PEDF), a protein that inhibits angiogenesis, is expressed in human choroidal neovascular membranes (CNVMs) and in tissues from an eye with polypoidal choroidal vasculopathy (PCV). In addition, to compare the expression of PEDF with that of vascular endothelial growth factor (VEGF), a known stimulator of angiogenesis, in these tissues. METHODS: CNVMs, associated with age related macular degeneration (AMD), angioid streaks, and PCV, were obtained during surgery. The expression of PEDF and VEGF in the excised subretinal fibrovascular membranes was determined by immunohistochemistry. RESULTS: PEDF and VEGF were strongly expressed in the vascular endothelial cells and retinal pigment epithelial (RPE) cells in the CNVMs where numerous new vessels were prominent (clinically active CNVMs). On the other hand, immunoreactivity for PEDF and VEGF was weak in the new vessels where fibrosis was prominent (clinically quiescent CNVMs). However, the RPE cells were still positive for PEDF and VEGF. The specimens from the eye with PCV also showed strong expression of PEDF and VEGF in the vascular endothelial cells and the RPE cells. CONCLUSION: Because PEDF is an inhibitor of ocular angiogenesis and an inhibitor of ocular cell proliferation, our results suggest that PEDF along with VEGF may modulate the formation of subfoveal fibrovascular membranes.

Aged↗

Biodegradation of microcystis and microcystins by indigenous nanoflagellates on biofilm in a practical treatment facility.

The potential for degradation of Microcystis and microcystins by organisms in biofilm in a practical biological treatment facility combined with conventional treatment processes was examined. Viable cells of Microcystis viridis, which produced microcystin LR, RR and YR, were degraded in 6 to 10 days by the addition of biofilm collected in early summer, mid-summer and autumn. Monas sp. grew remarkably well compared with other organisms in the samples of all seasons. Therefore, we conclude that Monas sp. was indigenous animals in the biological treatment facility and was able to degrade Microcystis cells. Some previous studies reported the predation of Microcystis cells by Monas guttula in pure culture conditions (monoxenic culture). We clarified that Monas sp. can grow and prey on Microcystis cells even in mixed culture including many kinds of other organisms in biofilm in a practical treatment facility. Also, intracellular microcystin LR, RR and YR in Microcystis cells could be degraded simultaneously with high reduction of Microcystis cells by organisms in biofilm.

Bacterial Toxins↗

A novel control process of cyanobacterial bloom using cyanobacteriolytic bacteria immobilized in floating biodegradable plastic carriers.

A process using a floating carrier for immobilization of cyanobacteriolytic bacteria, B.cereus N-14, was proposed to realize an effective in situ control of natural floating cyanobacterial blooms. The critical concentrations of the cyanobacteriolytic substance and B.cereus N-14 cells required to exhibit cyanobacteriolytic activity were investigated. The results indicated the necessity of cell growth to produce sufficiently high amounts of the cyanobacteriolytic substance to exhibit its activity and also for conditions enabling good contact between high concentrations of the cyanobacteriolytic substance and cyanobacteria. Floating biodegradable plastics made of starch were applied as a carrier material to maintain close contact between the immobilized cyanobacteriolytic bacteria and floating cyanobacteria. The floating starch-carriers could eliminate 99% of floating cyanobacteria in 4 d. Since B.cereus N-14 could produce the cyanobacteriolytic substance under the presence of starch and some amino acids, the cyanobacteriolytic activity could be attributed to carbon source fed from starch carrier and amino acids eluted from lysed cyanobacteria. Therefore, the effect of using a floating starch-carrier was confirmed from both view points as a carrier for immobilization and a nutrient source to stimulate cyanobacteriolytic activity. The new concept to apply a floating carrier immobilizing useful microorganisms for intensive treatment of a nuisance floating target was demonstrated.

Biocompatible Materials↗

Comparison of detection specificity of nitrifying bacteria in biofilm using fluorescence in situ hybridization and in situ fluorescent antibody methods.

The in situ fluorescent antibody and fluorescence in situ hybridization (FISH) methods are very useful in the in situ detection of specific bacteria like nitrifiers in a biofilm. In this study, simultaneous staining using the FISH and in situ fluorescent antibody methods was examined. As a result, no specific fluorescence was observed with either method when FISH was performed followed by the in situ fluorescent antibody method; however, when the in situ fluorescent antibody method was performed first followed by FISH, specific fluorescence was observed in both cases. Moreover, it was suggested that the detection specificities of FISH and the in situ fluorescent antibody method are almost identical.

Antibodies, Monoclonal↗