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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 235 records · Page 13Linked to original sources
PubMed2000

Multiple arteriosclerotic fusiform aneurysms of the superficial temporal artery--case report.

Superficial temporal artery (STA) aneurysms are very rare, and usually occur in young adult men due to blunt trauma as pseudoaneurysms. An 85-year-old male presented with two non-traumatic STA aneurysms. The aneurysms were ligated and resected. Histological examination showed arteriosclerotic fusiform aneurysm. The pathogenesis of non-traumatic aneurysm of the STA appears to be arteriosclerotic change and/or hemodynamic stress.

Aged↗
PubMed2000

Interhemispheric glioependymal cyst associated with agenesis of the corpus callosum--case report.

A male neonate was admitted because prenatal ultrasonography indicated central nervous system abnormalities. Neurological examination showed no abnormality except for electroencephalographic spike activities. Magnetic resonance imaging revealed a cystic lesion in the left interhemispheric fissure, agenesis of the corpus callosum, and microgyria in the left frontotemporal lobes. Cerebral blood flow (CBF) was diffusely reduced. The cyst wall was partially removed and a cyst-peritoneal shunt procedure was performed. The histological diagnosis was glioependymal cyst. The spike activity disappeared and CBF dramatically improved after the operation.

Agenesis of Corpus Callosum↗
PubMed2000

Vaccination of a refractory essential monoclonal cryoglobulinemia patient with cryoglobulin-pulsed dendritic cells.

We vaccinated a refractory essential monoclonal cryoglobulinemia patient with monocyte-derived DCs (Mo-DCs) pulsed with purified cryoglobulin as a tumor antigen. During the vaccinations, his acrocyanosis improved and we were able to reduce the number of hot baths used to treat his symptoms, with no side effects. Furthermore, cryoglobulin-specific proliferative responses were observed after the vaccination. As there was a recurrence of acrocyanosis after the final vaccination, vaccination with Mo-DCs pulsed with purified cryoglobulin would seem to be a useful treatment for refractory essential monoclonal cryoglobulinemia.

Antigens↗
PubMed2000

Are giant cells conidia in Sporothrix schenckii? -Freeze-fracture electron microscopic observation-.

Sporothrix schenckii is a well-known pathogenic dimorphic fungus. In this study, we focused on the plasma membrane ultrastructures of giant cells of S. schenckii seen mainly on Sabouraud's dextroseagar slant medium. In the organisms grown for 1, 2, 3, 4, 6 and 8 weeks at 27 and 37 degrees C on brain heart infusion and Sabouraud's dextrose agar slant media, the number of conidia, hyphae, brownish and non-brownish giant cells were counted in ten separated areas under light microscope (x100) to determine the culture conditions under which giant cells were generated. The results showed that brownish giant cells were predominantly seen after longer cultivation periods. Using freeze-fracture electron microscopy, larger oval- or round shaped cells can be identified as conidia by their plasma membrane ultrastructure characteristics, i.e, trench-like invaginations seen in ordinary mature conidia (Maeda M et al.; Can J Microbiol 33: 40, 1987). From these structural features seen by freeze-fracture electron microscopy, giant cells appeared possibly be conidia and were suggested to be starved because of their predominant existence under longer cultivation conditions.

Freeze Fracturing↗
PubMed2000

Expression of the OGG1-type 1a (nuclear form) protein in cancerous and non-cancerous human cells.

The human OGG1 gene encodes 8-hydroxyguanine DNA glycosylase. By RT-PCR analysis, five novel type 1 transcripts, in addition to eight known types (OGG1-types 1a to 1c and 2a to 2e), were identified. Among them, only the type 1a isoform contains both a nuclear localization signal and the entire DNA binding motif, suggesting the involvement of type 1a in chromosomal DNA repair. By Western blot analysis using a monoclonal antibody prepared by immunizing the whole type 1a protein, a 39 kDa type 1a protein was detected in lung cancer cell lines and peripheral lymphocytes. The type 1a protein was expressed at a similar level, irrespective of its polymorphic types characterized by distinct repair activity. By an immunocytochemical study, the majority of type 1a protein was localized in the nucleus. These results indicate that OGG1-type 1a protein is involved in the repair of 8-hydroxyguanine in chromosomal double-stranded DNA and constitutively expressed in cancerous and non-cancerous human cells.

3T3 Cells↗
PubMed2000

TGF-alpha as well as VEGF, PD-ECGF and bFGF contribute to angiogenesis of esophageal squamous cell carcinoma.

It has been demonstrated that vascular endothelial growth factor (VEGF) is associated with tumor progression as an angiogenic factor in esophageal squamous cell carcinoma (SCC)s. However, the role of other angiogenic factors such as transforming growth factor-alpha (TGF-alpha), platelet-derived endothelial cell growth factor (PD-ECGF), and basic fibroblast growth factor (bFGF) are still unknown in esophageal SCCs. In this study, we detected the expression of VEGF, TGF-alpha, PD-ECGF and bFGF in tissue specimens from 96 patients with SCC of the esophagus by immunohistochemical staining. To evaluate angiogenesis, endothelial cells were stained immunohistochemically and microvessel density (MVD) was counted in 24 cases. The positive rates for VEGF, TGF-alpha, PD-ECGF and bFGF were 65% (62/96), 67% (64/96), 66% (63/96), and 49% (47/96), respectively. Only TGF-alpha expression had a strong correlation with the average MVD (p=0.0059). However, the MVD increased as the number of positive factors for these 4 factors increased (p=0.0023). The expression of all of these factors significantly correlated to the depth of tumor invasion, and lymph node metastasis. Finally, survival analysis of the patients revealed that VEGF, TGF-alpha, and PD-ECGF were significant prognostic factors. However, multivariate analysis revealed that these factors were not prognostic. Thus, we suggest that TGF-alpha as well as VEGF, PD-ECGF and bFGF may be associated with angiogenesis, and the progression and metastasis of esophageal squamous cell carcinoma.

Adult↗
PubMed2000

PTEN/MMAC1 expression in esophageal squamous cell carcinomas.

The PTEN/MMAC1 gene at 10q23.3 is a novel tumor suppressor gene candidate. Various kinds of tumors have mutations in this gene. However, in some cancers PTEN/MMAC1 gene may be inactivated by mechanisms other than gene deletion and mutation, including promoter methylation or translational modification. The aim of this study was to determine whether there are abnormalities in the expression of PTEN/MMAC1 gene in esophageal cancer. Reverse transcription polymerase chain reaction and western blot were used to examine PTEN/MMAC1 expression in human esophageal squamous cell lines and normal cultured esophageal epithelial cells. Immunohistochemical staining was carried out to detect PTEN/MMAC1 expression in surgically resected esophageal squamous cell carcinomas and normal esophageal epithelium. All 30 esophageal cancer cell lines (KYSE series) and normal cultured esophageal epithelial cells expressed PTEN/MMAC1 mRNA. Western blot analysis confirmed that all the cell lines expressed PTEN/MMAC1 protein and there was no difference in expression level. Immunohistochemical study showed that the PTEN/MMAC1 protein was localized dominantly in the cytoplasm and strongly stained in all 42 surgically resected esophageal squamous cell carcinomas and normal esophageal epithelium. PTEN/MMAC1 is rarely associated with esophageal squamous cell carcinoma carcinogenesis.

Carcinoma, Squamous Cell↗
PubMed2000

Antibodies to different peptides in osteopontin reveal complexities in the various secreted forms.

We have generated synthetic peptides corresponding to various portions of human osteopontin (OPN) and have immunized rabbits and mice with these peptides to generate polyclonal and monoclonal antibodies specific to human OPN. We then generated six distinct sandwich enzyme-linked immunoabsorbent assay (ELISA) systems by using different pairs of polyclonal and monoclonal antibodies against human OPN. These systems allowed us to detect not only various isoforms and truncated forms of recombinant OPN, but also the glycosylated form of native urinary OPN. Most importantly, tumor-derived OPN was differentially detected by the six ELISA systems. The ELISA systems that we have developed will be useful for clarifying the functional roles for OPN in vivo in various physiologic and pathologic conditions.

Adult↗
PubMed2000

Mouse macrophage metalloelastase gene transfer into a murine melanoma suppresses primary tumor growth by halting angiogenesis.

Mouse macrophage metalloelastase (MME) has been associated with the generation of angiostatin, an internal fragment of plasminogen, which inhibits angiogenesis. To clarify whether tumor cells that consistently generate MME can suppress angiogenesis and, therefore, inhibit the growth of primary tumors in vivo, we transfected a cDNA coding for MME into murine B16-BL6 melanoma cells that grow rapidly and are MME deficient. The generation of active MME in MME-transfected clones was confirmed by immunoprecipitation followed by in vitro cleavage of plasminogen. Subcutaneous implantation of these stable clones in C57BL/6 mice inhibited primary tumor growth by an average of 73% (P = 0.00002), which directly correlated with a significant reduction of blood vessel formation (approximately 76%) in such tumors. Microangiography revealed massive angiogenesis in control tumors (mock and vector); however, in MME-transfected primary tumors it demonstrated a decreased and disrupted vascular network. Western blot analysis using a specific anti-mouse angiostatin antibody demonstrated a strong 38-kDa immunoreactive band in MME-transfected tumors and in the serum of mice bearing those tumor cells. These results show that placing MME gene directly into B16-BL6 melanoma cells is an effective approach to suppress primary tumor growth in vivo because it halts angiogenesis. Our data provide a feasible and promising strategy for gene therapy of cancer by targeting tumor vasculature.

Angiostatins↗
PubMed2000

[Evaluation of cardiac autonomic nerves by iodine-123 metaiodobenzylguanidine scintigraphy and ambulatory electrocardiography in patients after arterial switch operations].

The autonomic cardiac nerves reach the heart after passing through the vicinity of the aortic root and the pulmonary trunk. The arterial switch operation (ASO) completely transects the ascending aorta and the pulmonary trunk. Therefore, this surgical procedure virtually denerves the heart. Cardiac sympathetic denervation and reinnervation were evaluated in patients after ASO using iodine-123 metaiodobenzylguanidine (MIBG) myocardial scintigraphy and parasympathetic denervation and reinnervation using ambulatory electrocardiography [Holter electrocardiogram (ECG)]. MIBG scintigraphy was performed in 14 patients who underwent ASO (ASO group) and 3 patients who underwent other open heart surgery (control group). All patients in the ASO group underwent the operation in the neonatal or infantile period. Planar and single photon emission computed tomography (SPECT) images of the myocardium were obtained. Defect score was determined by the SPECT images as a semi-quantitative index. The mean interval between ASO and MIBG scintigraphy was 25.6 +/- 14.6 months. Holter ECG was also performed in 14 patients in the ASO group and 19 age-matched normal children. The Holter ECGs were plotted on a Lorenz plot. The H index, which is related to vagal tone for the cardiovascular system, was calculated from the R-R intervals. The mean interval between the ASO and Holter ECG was 8.3 +/- 9.7 months. MIBG scintigraphy in the control group demonstrated an almost normal homogeneous tracer uptake, but showed extremely reduced tracer uptake and significantly higher defect score in the ASO group. The extent and degree of the reduction of MIBG uptake improved with time after the ASO. The heart-to-mediastinum MIBG count ratio tended to increase with time. The H index of the ASO group was lower than that of normal children (< 12 months: Control group 0.0280 +/- 0.0068 vs ASO group 0.0219 +/- 0.0083), and gradually increased with time (1-3 years: 0.0470 +/- 0.0157 vs 0.0314 +/- 0.0124). These results indicate that MIBG scintigraphy reflects the presence of sympathetic denervation and the possibility of reinnervation after ASO, and that H index reflects the presence of parasympathetic denervation and the possibility of reinnervation after ASO. These are simple and useful methods for assessing the extent and degree of autonomic denervation and reinnervation.

3-Iodobenzylguanidine↗
PubMed2000

Down-regulation of human telomeric protein TRF1 gene expression during myeloid differentiation in human hematopoietic cells.

The maintenance of telomere length is crucial for cell survival. Recently, it has been indicated that the human telomeric protein TRF1 is involved in the negative feedback mechanism that stabilizes telomere length. We studied TRF1 mRNA expression in hematopoietic cells to clarify the relation between TRF1 and telomerase by semiquantitative reverse transcriptase-polymerase chain reaction. In polymorphonuclear cells and monocytes isolated from peripheral blood, relatively low levels of TRF1 mRNA expression were seen, compared with those of lymphocytes and CD34+. We then assessed TRF1 mRNA expression in CD34+ cells cultured in vitro with growth factors. After 4 weeks of culture, all the cells showed myeloid differentiation, and telomerase activity was down-regulated. TRF1 mRNA was expressed in CD34+ cells but was down-regulated in cells cultured for 4 weeks. We conclude that TRF1 mRNA expression is down-regulated in accordance with telomerase down-regulation during the course of myeloid differentiation.

Antigens, CD34↗
PubMed2000

[Tracheobronchoplasty for lung cancer: operative indications by limited category].

Three limited categories of tracheobronchoplasty are applicable in lung cancer patients. A1 is for patients who would otherwise be inoperable due to the lack of cardiopulmonary reserve. R1 is for early-stage cancer localized to the hilar bronchus and which aims to preserve lung function by active limited category. R3 tracheo-bronchoplasty preserves respiratory function in noncurative cases. The percentage of patients undergoing A1, R1, and R3 tracheo-bronchoplasty were 14.2%, 16.8% and 4.2%, respectively (35.2% of total patients undergoing bronchoplasty). Of the total patients, 18.9% underwent carinoplasty, and of these only 4 (2.6%) were eligible for the 3 categories of tracheo-bronchoplasty. Of lung cancer patients who underwent bronchoplasty, A1 was performed in 12.6%, R1 in 16/3%, and R3 in 3.7% (32.6% of the total). The use of bronchoplasty increased from 7.8% to 21.9% of lung cancer surgery after the introduction of dose-intensive induction chemotherapy (DIIC), mainly due to the increase in the use of interlobar techniques (20.5% of the total) in the smaller bronchial lesions present after DIIC. The 5-year survival rates of patients undergoing A1, R1, and R3 tracheo-bronchoplasty were 59.6%, 64.9%, and 0%, respectively. No anastomotic recurrence was seen in the 32 patients who underwent R1. Based on these results, tracheo-bronchoplasty increases survival in patients who receive the A1 category and preserves lobar function in those who receive R1 and R3.

Bronchi↗
PubMed2000

[Experimental study of esophageal covered stent for prevention of migration: use of clay to simulate stenosis of the esophagogastric junction or anastomosis site].

PURPOSE: An inner-covered Spiral Z-stent (IC-SZ) developed by our group was examined for its effectiveness in preventing migration by experimental comparison with commercially available esophageal covered stents. MATERIALS AND METHODS: The following six types of stents were used: inner-covered Spiral Z-stents with diameters of 16 mm (small IC-SZ) and 19 mm (large IC-SZ), outer-covered Spiral Z-stent (OC-SZ), covered Wallstent, covered Ultraflex stent, and Cook Z-stent. Experimental models were prepared using clay to simulate stenosis of the esophagogastric junction or anastomosis site due to tumor, and each stent was placed in the clay. After the stent had been fully expanded with a balloon catheter, one of its ends was pulled until the stent migrated out of the clay, and the traction force was measured. The inner cavity of the stent placed in the clay was observed using an endoscope. RESULTS: The mean maximal traction force required to pull the stents out of the clay were as follows, in decreasing order: 4.14 +/- 0.39 kg for the large IC-SZ, 4.12 +/- 0.83 kg for the small IC-SZ, 3.64 +/- 0.44 kg for the Cook Z-stent (p < 0.05), 3.34 +/- 0.62 kg for the covered Ultraflex stent (p < 0.05), 1.53 +/- 0.43 kg for the OC-SZ (p < 0.01), and 0.56 +/- 0.16 kg for the covered Wallstent (p < 0.01). The force required to pull out the large IC-SZ stent was the greatest, showing a significant difference from the values for the other four types of stents (excluding the small IC-SZ). Observation using an endoscope revealed that the wire of the IC-SZ stent was almost entirely embedded in the clay, whereas the wires of other stents were not. CONCLUSION: The IC-SZ stent may be less likely to migrate than other esophageal covered stents.

Biomechanical Phenomena↗
PubMed2000

Differential expression of MT1-MMP (MMP-14) and collagenase III (MMP-13) genes in normal and wounded rat corneas.

PURPOSE: Several members of the matrix metalloproteinase (MMP) group have been identified in the rat cornea during corneal wound healing. The aim of the present study was to identify additional members of the MMP gene family in the rat cornea and localize the expression of membrane type-1 matrix metalloproteinase (MT1-MMP; MMP-14) and collagenase III (MMP-13) in normal and wounded corneas. METHODS: Adult rats underwent laser keratectomy on the right eye. Unwounded left eyes were normal controls. Corneas were collected and processed at different times post-wounding. Reverse transcription-polymerase chain reaction (RT-PCR) and DNA sequencing were used to discover the MMP genes expressed in the corneas. In situ hybridization was performed to localize the mRNA expression of MMP-14 and MMP-13. RESULTS: MMP-13 mRNA was detected in epithelial cells of wounded corneas, but not in normal controls; MMP-14 was found in both normal and wounded corneas. MMP-14 mRNA was expressed predominantly in the stromal keratocytes and rarely in the basal epithelial cells in normal and wounded corneas. MMP-13 mRNA was localized exclusively to basal cells of the epithelium at the wounded area from 6 hours to 3 days after wounding. CONCLUSIONS: MMP-14 and MMP-13 expression in rat corneas parallels that of gelatinases A and B, respectively. MMP-13 may play an important role in the gelatinase B-associated proteolytic cascade that allows rapid turnover of the extracellular matrix (ECM) components during corneal wound healing. MMP-14 may contribute to removing abnormal ECM components through activation of gelatinase A in rat corneas.

Animals↗
PubMed2000

Squamous cell carcinoma arising from lesions of porokeratosis palmaris et plantaris disseminata.

We report a 63-year-old Japanese man with numerous hyperkeratotic papules of porokeratosis palmaris et plantaris disseminata (PPPD) who developed multiple squamous cell carcinomas on the lesional sites of the palms and soles. The hyperkeratotic papules, which showed tightly packed columns of parakeratotic cells in the cornified layer (cornoid lamella), lost granular layer, and dyskeratotic keratinocytes in the epidermis below the cornoid lamella histologically, had been noticed on the palms and soles from the age of 28 and 43, respectively. He has no family history of such hyperkeratotic papules. Treatment with etretinate (10-50 mg/day) was given discontinuously, and the total dose of etretinate amounted to approximately 21 g over 14 years (average: 0.07 mg/kg/day). He noticed erosions on the hyperkeratotic papules on the left sole and palm more than 9 months after cessation of treatment with etretinate. Histological findings showed numerous atypical keratinocytes in the epidermis and upper dermis with mononuclear cell infiltration seen in the upper dermis. The diagnosis of squamous cell carcinoma arising from the lesions of porokeratosis palmaris et plantaris was made. Five erosions with histologically malignant changes were removed 1 cm from the margin of the erosions. These findings suggest that etretinate may have an inhibitory action on malignant changes in PPPD.

Aged↗
PubMed2000

[Mid-term results of the arterial switch operation for transposition of the great arteries: effect of fresh autologous pericardial patch in preventing postoperative pulmonary stenosis].

To evaluate the differences in patch-materials used to reconstruct the pulmonary artery in arterial switch operation for transposition of the great arteries, we compared mid-term results in 50 consecutive survivors who underwent arterial switch operation. In 35 patients (XP-group), the pulmonary artery was reconstructed using a glutaraldehyde-treated heterologous pericardial patch, while in 15 patients (AP-group) it was reconstructed using a fresh autologous pericardial patch. A W-shaped patch was used in 14 patients of the XP-group. In 21 patients of the XP-group and all those of the AP-group, a square patch was used. The mean length of follow-up has been 94.1 +/- 38.1 months after surgery in XP-group, and 16.7 +/- 11.8 months in AP-group, respectively. Four patients in XP-group required balloon angioplasty for pulmonary stenosis and 5 patients in XP-group underwent reoperation, but no patients in AP-group required balloon angioplasty or reoperation for pulmonary stenosis. The risk factors influencing postoperative pulmonary stenosis (sex, age at surgery, preliminary pulmonary artery banding, patch shape and material) were analyzed by multiple regression analysis. The patch material (heterologous patch) was the only identifiable risk factor for pulmonary stenosis. These data suggest that pulmonary artery reconstruction with an autologous pericardial patch may be effective to prevent postoperative pulmonary stenosis, although the long-term prognosis remains unknown.

Female↗
PubMed2000

[Modified Konno procedure for a child with left ventricular outflow tract obstruction after repair of atrioventricular septal defect: a transaortic transpulmonary approach].

A one-year-old infant underwent repair of atrioventricular septal defect with common orifice. About 2 years later, echocardiography revealed a left ventricular outflow tract obstruction for the first time. Because of progression of the obstructive lesion, a modified Konno procedure through a transaortic transpulmonary approach was later performed at 8 years old, and the postoperative course was uneventful. This is a useful procedure for left ventricular outflow tract obstruction with normal aortic valve and aortic annulus, because it can both preserve a native aortic valve and dose not necessitate right ventriculotomy in resection of hypertrophied muscle and patch enlargement of interventricular septum.

Aorta↗