Search PubMed⌕ Search

Biomedical subjects

Osamu Katoh

Publications and source records attributed to Osamu Katoh.

At least 37 records · Page 2Linked to original sources
PubMed2003

Comparison of cutting balloon vs stenting alone in small branch ostial lesions of native coronary arteries.

Angioplasty of small vessels is associated with a higher rate of restenosis, even in the ostium. The present study compared the acute, late results of cutting balloon vs those of stenting alone in small branch ostial lesions of native coronary arteries and the effect on the parent vessel. The study group comprised 61 patients with successful angioplasty of smaller branch ostial lesions in native coronary arteries. The reference vessel diameter was between 2.5 and 3.0 mm. Patients were divided into 2 groups: group I (cutting balloon, n=30) and group II (stenting alone, n=31). After intervention, patients in group II achieved significant acute lumen gain, larger minimal lumen diameter (MLD) and less diameter stenosis. At 3-month follow-up, the MLD and diameter stenosis of the 2 groups were almost identical; however, late loss was lower in group I. At the 6-month follow up, the cumulative restenosis rate was 41% (11/27) in group I compared with 63% (19/31) in group II (p=0.05), and the target lesion revascularization was also lower in the cutting balloon group [29% (8/27) vs 53% (16/30) p=0.05]. In group 1, the MLD of the parent vessel did not change before, after cutting balloon or at follow-up. In contrast, there were significant reductions in parent vessel MLD following stenting alone and at follow-up. Plaque shift did not occur in the cutting balloon group. Cutting balloon angioplasty is a feasible approach for the treatment of small branch ostial lesions and does not cause significant narrowing of the parent vessel.

Aged↗
PubMed2003

Damage of the mouse testis by tritiated water and 137Cs-gamma-rays.

Tritiated water at 23.2, 46.3 or 92.5 MBq/animal and 137Cs-gamma-rays at 9.5 Gy (equivalent 370 MBq) or lower doses were administered to 6-week old male C3H/HeNCrj and C57BL/6NCrj mice, as well as F1 Crj: B6C3F1 (C3H x C57BL) progeny. Each set of six to ten animals were autopsied 30 days after the first irradiation. Testis weights were decreased dose dependently, relative values being highest in the C3H and lowest in the C57BL case, with B6C3F1 intermediate. Vacuolization in seminiferous tubules appeared in the 23.2 MBq group and increased with the dose. Focal pyknosis and karyomegaly were found at 46.3 MBq, while primary and secondary spermatocytes and spermatids disappeared with 92.5 MBq. Only a few spermatogonia and Sertoli cells remained after exposure to 9.5 Gy 137Cs-gamma-rays. Sizes of seminiferous tubules were decreased dose dependently, with no strain differences. When male B6C3F1 mice were irradiated with Cs-gamma-rays at 0.119 (equivalent 4.63 MBq tritiated water) or 2.38 Gy (equivalent 92.5 MBq tritiated water), body weights and size of the seminiferous tubules were decreased at both doses, and the larger dose also caused reduction of testis weight and abnormal sperm. However, all changes except for the alteration in weights had disappeared 1 month after the final irradiation. It is considered that the size of seminiferous tubules may be a good parameter for radiation damage in the testis.

Animals↗
PubMed2002

Expression of the Krüppel-type zinc finger gene, ZK7, in head and neck squamous cell carcinoma and normal mucosa.

ZK7 is thought to be involved in the inhibitory effect of vascular endothelial growth factor on apoptotic cell death in human hematopoietic cells. In the present study, we examined the effects of ZK7 on human head and neck squamous cell carcinomas (HNSCC). The expression levels of messenger RNA for ZK7 in HNSCC clinical specimens exposed to platinum drugs and/or ionizing radiation were found to be higher than those in non-exposed specimens (P=0.0116). Cell lines examination showed that ZK7 over-expressing cells had low sensitivity to the chemotherapeutic agent cisplatin and ionizing radiation. These results suggest that ZK7 may inhibit apoptotic cell death in HNSCC.

Adult↗
PubMed2002

EVI1 is expressed in megakaryocyte cell lineage and enforced expression of EVI1 in UT-7/GM cells induces megakaryocyte differentiation.

3q21q26 syndrome, an acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) with chromosomal translocations or inversions between the bands 3q21 and 3q26, is frequently associated with dysmegakaryocytopoiesis and increased platelet counts at the initial diagnosis. Since the EVI1 gene at 3q26 is transcriptionally activated in 3q21q26 syndrome, we assessed the role of EVI1 gene expression in the abnormal megakaryocytic differentiation in 3q21q26 syndrome. RT-PCR analysis of various types of hematopoietic cells revealed that the EVI1 gene is expressed specifically in CD34(+) cells, megakaryocytes, and platelets. UT-7 is a human immature megakaryoblastic leukemia cell line with dependence for the growth on granulocyte-macrophage colony-stimulating factor (GM-CSF) (designated at UT-7/GM) and with a differentiation capacity to erythroid (UT-7/EPO) and megakaryocytic lineages (UT-7/TPO) by erythropoietin (EPO) and thrombopoietin (TPO), respectively. Among three UT-7 sublines, UT-7/GM, UT-7/EPO, and UT-7/TPO, expression of the EVI1 gene was detected at low levels in UT-7/GM and UT-7/EPO cells, but was detected at a higher level in UT-7/TPO cells. When UT-7/GM cells were cultured with TPO, the level of EVI1 expression was increased, along with increased numbers of polynuclear megakaryocytes and expression of the platelet factor 4 (PF-4) gene. Furthermore, forced expression of the EVI1 gene in UT-7/GM cells changed their morphology to polynuclear megakaryocytes, stopped their growth, and induced cell death within a month. These data indicate that expression of the EVI1 gene is involved in progression of megakaryocytic differentiation and, thus, the dysmegakaryocytopoiesis in 3q21q26 syndrome could be partly due to an enhanced differentiation capacity of leukemia cells and/or megakaryocytes by constitutive expression of the EVI1 gene.

Animals↗
PubMed2002

High expression of MCL1 gene related to vascular endothelial growth factor is associated with poor outcome in non-Hodgkin's lymphoma.

We evaluated the level of MCL1 gene expression using quantitative reverse transcription polymerase chain reaction in lymph nodes of patients with non-Hodgkin lymphoma (NHL). MCL1 expression in patients in complete remission (CR) was significantly lower than in patients with progressive disease (PD, P = 0.0043). The disease-free survival rate was significantly higher in patients with MCL1 levels below the median level (P = 0.007). We also found that the level of expression of MCL1 mRNA was related to that of vascular endothelial growth factor mRNA in NHL lymph nodes. Our data suggest that the MCL1 expression level could be considered a prognostic factor in NHL.

Adolescent↗
PubMed2002

The impact of tranilast on restenosis after coronary angioplasty: the Second Tranilast Restenosis Following Angioplasty Trial (TREAT-2).

BACKGROUND: The Tranilast Restenosis Following Angioplasty Trial showed that oral administration of 600 mg/day of tranilast for 3 months markedly reduced the restenosis rate after percutaneous transluminal coronary angioplasty (PTCA) for de novo lesions. METHODS: We conducted the second multicenter, randomized, double-blinded placebo-controlled trial. A total of 297 patients with 329 lesions were randomly assigned to treatment with tranilast or a placebo for 3 months after successful PTCA for both de novo and restenotic lesions. Angiographic follow-up examination was done at 3 months, and angiograms were interpreted with a quantitative approach. RESULTS: Two hundred thirty-nine lesions (72.6%) in 216 of the patients (72.7%) met the criteria and were included in the assessment of restenosis. Lesion restenosis was defined as a loss of 50% or more of the initial gain, and the restenosis rates were 18.8% in the tranilast group (n = 112) and 44.1% in the placebo group (n = 127; P =.00005). The restenosis rate, defined as a percent stenosis of > or = 50% at follow-up examination, was also significantly lower in the tranilast group (25.9% versus 41.9%; P =.012). The numbers of restenotic lesions were 38 (33.9% of 112) in the tranilast group and 30 (23.6% of 127) in the placebo group. In restenotic lesions, the lesion restenosis rate was significantly lower in the tranilast subgroup (18.4% versus 53.3% with the first restenosis criterion; P =.004). CONCLUSION: The oral administration of tranilast for 3 months markedly reduced the restenosis rate after PTCA, even in restenotic lesions.

Administration, Oral↗
PubMed2002

Increased MCL-1 expression is associated with poor prognosis in ovarian carcinomas.

To investigate the potential role of the BCL-2 gene family (BAX, BCL-2, MCL-1, and BCL-XL) in ovarian cancer development and progression, mRNA expression levels of these genes were measured using semi-quantitative PCR in epithelial ovarian tumor tissues and normal ovaries. The immunohistochemical expression of MCL-1 in ovarian tumors was also examined. The expression levels of BAX and MCL-1 mRNA were significantly higher in ovarian cancers and in adenomas than in normal ovaries (P < 0.05). In contrast, the BCL-2 mRNA expression level in ovarian cancers was significantly lower than in ovarian adenomas and in normal ovaries (P < 0.05). Expression of BCL-XL mRNA was no different between normal ovaries and ovarian tumors. Log-rank testing showed that low BAX mRNA expression and high MCL-1 mRNA expression significantly correlate with poor survival for patients with stage III ovarian carcinomas (BAX, P = 0.05; MCL-1, P = 0.02). Immunohistochemical analysis showed that diffuse-positive expression of MCL-1 protein in mucinous carcinomas was significantly higher than in mucinous low malignant potential (LMP) tumors (P = 0.03). In ovarian cancer cases, diffuse-positive expression of MCL-1 protein significantly correlates with advanced clinical stage, high histologic grade, and poor survival (stage, P < 0.01; grade, P = 0.01; survival, P = 0.01). These results suggest that increased MCL-1 expression may play an important role in replacing the functions of increased BAX and decreased BCL-2 in ovarian carcinoma cells, thereby promoting cell survival, and resulting in a poor prognosis for patients with ovarian cancer.

Cell Survival↗
PubMed2002

Blue light inhibits the growth of B16 melanoma cells.

Although a number of studies have been carried out to examine the biological effects of radiation and ultraviolet radiation (UV), little is known concerning the effects of visible light. In the present study, exposure of B16 melanoma cells to blue light (wavelength 470 nm, irradiance 5.7 mW / cm(2)) from a light-emitting diode (LED) inhibited cell growth in proportion to the period of exposure, with no increase observed in the number of dead cells. The number of B16 melanoma colonies that formed after exposure to blue light for 20 min was only slightly less than that in non-exposed controls, but the colony size as assessed by the area covered by colonies and cell counts per colony were markedly decreased. The percentages of G0 / G1 and G2 / M phase cells were markedly increased, with a reduction in S phase cells as determined by flow cytometry after exposure to blue light. Furthermore, analysis of the incorporation of 5-bromo-2'-deoxyuridine (BrdU) into DNA also showed a reduction in the percentage of S phase cells after exposure. These results indicate that blue light exerts cytostatic effects, but not a cytocidal action, on B16 melanoma cells.

Animals↗
PubMed2002

Heparin-binding EGF-like growth factor gene transcription regulated by Cdx2 in the intestinal epithelium.

Development and differentiation of the intestinal epithelium appear to be regulated by various growth factors. Using cDNA microarrays, we identified heparin-binding EGF-like growth factor (HB-EGF) as one of the genes induced by intestinal-specific transcription factor Cdx2 in an intestinal undifferentiated rat cell line, intestinal epithelial cell (IEC)-6. Both Cdx2 and HB-EGF stimulated cell proliferation and migration, and their effects were inhibited partially by an EGF receptor-specific tyrosine kinase inhibitor, PD-153035. HB-EGF may function as one of the mediators of Cdx2 and may be associated with the proliferation and migration in the intestinal epithelium. The Cdx2 protein can bind to the Cdx2-binding element of the HB-EGF gene. Reporter gene analyses showed that the HB-EGF gene promoter is Cdx2 responsive and that the activity of the promoter in the IEC-6 cells depends on the number of consensus Cdx2-binding site-like sequences. These data indicate that HB-EGF gene expression can be regulated by Cdx2 and serves to mediate the control of Cdx2 of the proliferation and migration of IEC-6 cells.

Animals↗
PubMed2002

Role of plaque proliferation in late lumen loss after directional coronary atherectomy.

Previous reports suggest that vessel remodeling is the most important factor in late lumen loss in non-stented lesions, but because results of directional coronary atherectomy (DCA) show that increased plaque area (PA) is also important, the aim of this study was to redefine the mechanism of late lumen loss after DCA. One hundred and twenty lesions that underwent DCA with intravascular ultrasound (IVUS) guidance and serial IVUS analysis were studied, and vessel area (VA), lumen area (LA), PA (VA-LA) and corrected values (each value divided by the value of VA pre procedure to correct the vessel size) were analyzed. During follow-up, corrected VA (cVA) decreased by 0.058 +/- 0.191, whereas corrected PA (cPA) increased by 0.087 +/- 0.159. Though the %PA (PA/VA) after the procedure showed significant negative correlation with the subsequent change in cPA, it did not correlate with the subsequent change in cVA. In conclusions, the mechanism of late lumen loss after DCA consists of both arterial remodeling and plaque proliferation, and the residual %PA after the procedure determines the subsequent lumen loss. With a lower %PA, a change in the PA contributes more to late lumen loss than do changes in VA. With a high %PA, a change in the VA contributes more to late lumen loss.

Atherectomy, Coronary↗
PubMed2002

Prevention of development of N,N'-dimethylhydrazine-induced colon tumors by a water-soluble extract from cultured medium of Ganoderma lucidum (Rei-shi) mycelia in male ICR mice.

The protective effects of a dietary water-soluble extract from cultured medium of Ganoderma lucidum (Rei-shi or Mannentake) mycelia (designated as MAK) against development of colon tumors were investigated in male ICR mice. The animals were given weekly injections of N,N'-dimethylhydrazine (DMH, 10 mg/kg body weight) for the initial 10 weeks to induce colon carcinogenesis, and then fed on diet with or without 5% MAK for 10 weeks. There were no significant differences in incidence and the total number of colon tumors between the groups. However, the MAK diet group demonstrated significantly reduced sizes of tumors in comparison with the MF diet group. Moreover, this was linked to a lowered PCNA positive index and shortening of the germinal region in the colon. beta-catenin positive tumor cell nuclei were also significantly decreased in the MAK group. The present results thus indicate that dietary MAK could act as a potent chemopreventive agent for colon carcinogenesis.

1,2-Dimethylhydrazine↗
PubMed2002

[Stent implantation for iliac compression syndrome with acute deep vein thrombosis: a case report].

An 80-year-old woman presented with left lower limb pain and swelling with tenderness over the great saphenous vein. Venography revealed thrombus in the lower leg vein and occlusion of the femoral vein. A temporary vein filter was placed below the renal vein and catheter intervention was performed. The wire was carefully advanced from the left femoral vein to the vena cava. Hard resistance was felt at the proximal iliac vein. After balloon dilation, intravascular ultrasonography showed a very flat lumen at the occlusion site. Stent implantation was performed followed by anticoagulation therapy. Venography at 3 months follow-up showed a widely opened iliac vein. Angiography showed the occlusion site was the crossing point of the right iliac artery and left iliac vein. Stenting for iliac compression syndrome is effective to maintain patency of the vein.

Aged↗
PubMed2002

Defects of granulopoiesis in patients with severe congenital neutropenia.

To confirm the abnormalities of primitive myeloid progenitor cells in patients with severe congenital neutropenia (SCN), we studied their responsiveness to hematopoietic factors including granulocyte colony-stimulating factor (G-CSF). In all SCN patients studied no abnormalities of granulocyte colony-stimulating factor receptor (G-CSFR) gene were detected by polymerase chain reaction-single-strand conformation polymorphism analysis and sequence analysis. A flow cytometric analysis of bone marrow cells based on the expression of CD34, Kit receptor, and G-CSFR demonstrated a reduced frequency of CD34+/Kit+/G-CSFR+ cells in patients with SCN. The granulocyte/macrophage (GM)-colony formation of CD34+/Kit+/G-CSFR+ cells in patients was markedly decreased at all concentrations of G-CSF in serum-deprived semisolid culture. The responsiveness of CD34+/Kit+/G-CSFR+ cells in patients showed a reduced response to the combination of stem cell factor, the ligand for flk2/flt3, and interleukin-3 with or without G-CSF in serum-deprived semisolid and liquid suspension cultures. In contrast, no difference in the responsiveness of CD34+/Kit+/G-CSFR- cells was noted between SCN patients and normal subjects. The bone marrow cells from a patient who underwent bone marrow transplantation showed a restoration of both the reduced frequency and the decreased level of GM-colony formation of CD34+/Kit+/G-CSFR+ cells. These results demonstrate that the presence of qualitative and quantitative abnormalities of primitive myeloid progenitor cells expressing G-CSFR may play an important role in the impairment of granulopoiesis in patients with SCN.

Antigens, CD34↗
PubMed2002

Effects of weaning by surrogate mothers (ACI) on tumor development in SD rats treated with methylnitrosourea (MNU) and/or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG).

In this experiment, methylnitrosourea (MNU) was administered, followed by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), to assess effects of surrogate mothering on tumor. One or two day old male SD pups were treated with or without 30 mg/kg body weight of MNU and nursed by SD or ACI surrogate mothers for 5 weeks. When 6-weeks-old they were then treated with 100 ppm MNNG or tap water for 16 weeks. The tumor incidence in the MNNG alone group was significantly lower than with MNU alone or MNU+MNNG (p < 0.01). Kidney or nerve tumors mainly developed in the MNU group, gastric tumors in the MNNG group, and the two combined in the MNU+MNNG group. The incidence and mean number of tumors did not significantly differ between the two weaning groups. However, mean survival time with the ACI surrogate mothers after treatment with MNU was increased as compared with the SD mother group. Cumulative development of tumors in the ACI surrogate mother group was also delayed (p < 0.05). Similar results were obtained with MNU+MNNG and MNNG alone. The present experiment suggested that tumor induction might be effected by components of the mother's milk.

Animals↗