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Biomedical subjects

T Koike

Publications and source records attributed to T Koike.

862 records · Page 48Linked to original sources
PubMedDate not supplied

An aggressive case of Burkitt's lymphoma with t(8;14) and c-myc rearrangement transformed from CD5+ B-cell lymphoma.

We experienced a case of Burkitt's lymphoma showing an unusual surface phenotype, CD5 expression, at an early stage of the disease. Initially, this patient showed massive abdominal para-aortic lymph node swelling which rapidly developed into leukemic change. Based on the clinical course and cytogenetic features of lymphoblasts in the bone marrow, which showed t(8;14) and c-myc gene rearrangement, the patient was diagnosed with Burkitt's lymphoma. Combination chemotherapy induced short-term remission, but central nervous system (CNS) involvement developed, followed by a regrowth of lymphoma cells in the bone marrow. The bone marrow at the end stage showed monotonous expansion of large cells with conspicuous vacuolation in the basophilic cytoplasm. The initial lymphoma cells showed pan-B markers and were CD5 positive but weakly CD10 positive; however, the lymphoma cells obtained from the bone marrow at the terminal stage did not express CD5. The chromosomal t(8;14) was seen, and identical rearrangement of immunoglobulin heavy chain joining gene and c-myc gene were detected by Southern blot analysis in the bone marrow lymphoblasts throughout the clinical course. This case is evidence that remarkable transformation of CD5-positive lymphoblasts to CD5-negative lymphoblasts occurred in an identical clone of Burkitt's lymphoma.

Aged↗
PubMedDate not supplied

Why do neurons die when deprived of trophic factor?

In this commentary we present circumstantial evidence which supports the hypothesis that neuronal death produced by trophic factor deprivation (i.e., axotomy, target loss, etc.) is not a passive process resulting from a loss of trophic stimulation. Rather, we suggest that it is due to the activation of an endogenous "suicide program" requiring mRNA and protein synthesis. The possible mechanistic relationship of neuronal death to death of other cell types, both in the developing and adult organism, is discussed. If this hypothesis of active death is true, then loss of transcriptional control of this program may be involved in neuronal attrition in aging or neurodegenerative disease.

Animals↗
PubMedDate not supplied

Advanced glycation endproducts and diabetic nephropathy.

Diabetic nephropathy is currently the single largest cause of endstage renal disease (ESRD) in the United States and many European countries. The primary cause for the development of diabetic complications (including diabetic nephropathy) is persistent exposure to hyperglycemia, although genetic and other incompletely understood factors also play an important role. Although much consideration has been given to the pathogenesis and genetics of the disease itself, the mechanisms by which persistent exposure to hyperglycemia cause biochemical and metabolic alterations have been very sketchily understood. Recently, a growing body of evidence has linked the accumulation of the late products of glucose-protein interaction to a variety of chronic complications, including diabetic nephropathy. The formation of irreversible advanced glycosylation endproducts (AGEs) resulting from the spontaneous reaction between glucose and proteins occur most noticeably on long-lived structural proteins. Recent studies demonstrate that the pathogenesis of diabetic nephropathy is caused by the hyperglycemia-accelerated formation of AGEs. Also, reactive AGE peptides in the circulation are thought to play a role as a new version of so called middle molecule toxic substances. This evidence is opening a new window for our understanding of the pathogenesis of diabetic nephropathy.

Animals↗
PubMedDate not supplied

Analysis of synergism between stem cell factor and granulocyte-macrophage colony-stimulating factor on human megakaryoblastic cells: an increase in tyrosine phosphorylation of 145 kDa subunit of c-kit in two-factor combination.

In normal hematopoiesis, stem cell factor (SCF) stimulates survival, proliferation and differentiation of hematopoietic progenitors. Although SCF acts synergistically with a variety of cytokines, the mechanism of growth factor-cooperation remains to be determined. To analyze the synergism between SCF and granulocyte-macrophage colony-stimulating factor (GM-CSF), we established a new megakaryoblastic cell line, HML-2, by culture in the presence of both SCF and GM-CSF. While SCF alone or GM-CSF alone supported modest cell growth, SCF and GM-CSF together induced substantial growth of this cell line. SCF alone tyrosine-phosphorylated several bands including the 145 kDa subunit of c-kit. GM-CSF alone did not cause the tyrosine phosphorylation of the 145 kDa subunit, but markedly up-regulated the expression of the 145 kDa subunit of c-kit. The combination of SCF and GM-CSF resulted in a synergistic increase in tyrosine phosphorylation of the 145 kDa subunit of c-kit. Several proliferation inhibitors which removed the two-factor interaction on the growth of the HML-2 cells down-regulated the 145 kDa subunit of c-kit. Thus, a synergistic increase in tyrosine phosphorylation of the 145 kDa subunit of c-kit may be one possible mechanism underlying the cooperation of SCF and GM-CSF on the HML-2 cell growth.

Blotting, Western↗
PubMedDate not supplied

Effects of transfection of p210bcr-abl and bcr-v-abl into the factor-dependent human leukemia cell line HSM-911.

In order to clarify the action of the bcr-abl, a growth factor dependent human leukemic cell line (HSM-911) was transfected with p210bcr-abl or bcr-v-abl by electroporation. The cells transfected with bcr-v-abl, but not the cells transfected with p210bcr-abl, became growth factor independent. Some clones of the cells transfected with p210bcr-abl demonstrated cellular maturation (nuclear segmentation, becoming positive for naphthol ASD chloroacetate esterase, the disappearance of CD34 expression and the appearance of glycophorin A and CD10 expression). Moreover, these clones transfected with p210bcr-abl demonstrated apoptosis (increased expression of Fas and DNA ladder formation suggesting apoptotic DNA fragmentation). These findings demonstrated the different actions of p210 bcr-abl and bcr-v-abl, the former of which gave the cells the characteristics of maturation like the cells from chronic myelogenous leukemia, and the latter of which rendered the cells grow autonomously.

Apoptosis↗
PubMedDate not supplied

Participation of alpha IIb beta 3 in platelet microparticle generation by collagen plus thrombin.

We investigated the role of alpha IIb beta 3 in microparticle generation by normal and thrombasthenic platelets stimulated with collagen plus thrombin. Microparticle generation by normal platelets was scarcely inhibited by monoclonal antibodies for glycoprotein Ib and glycoprotein IX. Although one monoclonal anti-alpha IIb beta 3 antibody (NNKY1-32) partly inhibited microparticle generation, 3 other monoclonal anti-alpha IIb beta 3 antibodies had little effect. However, the combination of 4 monoclonal anti-alpha IIb beta 3 antibodies or treatment with a polyclonal anti-alpha IIb beta 3 antibody significantly inhibited microparticle generation (p < 0.05). Microparticle generation by thrombasthenic platelets also occurred after stimulation with collagen plus thrombin, although at a significantly lower level compared with normal platelets. Monoclonal antibodies for resting alpha IIb beta 3, P-selectin, activated alpha IIb beta 3 and beta 2-glycoprotein I bound to microparticles from healthy platelets. In contrast, only a monoclonal antibody for beta2-glycoprotein I bound to thrombasthenic microparticles. These results suggest that microparticle generation by collagen plus thrombin occurs via two different mechanisms which are dependent and independent of alpha IIb beta 3, respectively. The alpha IIb beta 3-dependent mechanism appears to require activation of alpha IIb beta 3.

Amino Acid Sequence↗
PubMedDate not supplied

The necessity of chest physical therapy for thoracoscopic oesophagectomy.

Radical surgery for thoracic oesophageal cancer is highly invasive and often leads to respiratory complications; thoracoscopic surgery is a less-invasive alternative. We examined the need for chest physical therapy (CPT) after thoracoscopic oesophagectomy. Thirty-six consecutive patients, randomly selected for either thoracotomy or thoracoscopic surgery, were included in a randomized clinical trial and received CPT under the same protocol. During short-term post-operative follow-up, both groups showed a marked reduction in respiratory function and responded to CPT to the same extent, although 2 weeks after surgery some parameters of respiratory function were significantly higher in the thoracoscopy group. Thoracoscopic surgery has been reported to be less invasive than standard thoracotomy, but our results suggest that the procedure is also invasive with respect to respiratory function and that CPT should be performed before and after thoracoscopic surgery.

Aged↗
PubMedDate not supplied

Relationship between evoked otoacoustic emissions and middle-ear dynamic characteristics.

Evoked otoacoustic emissions (EOAEs) are considered to originate from outer hair cell movement and to be transmitted to the external auditory meatus through the ossicular chain and eardrum in a retrograde fashion. Therefore, the effect of the middle ear on EOAEs seems to be large. A sweep frequency middle-ear analyzer (MEA) has been developed that gives much more information on middle-ear dynamic characteristics than a conventional impedance meter. In this paper, applying our own EOAE measuring system and the MEA, EOAEs and middle-ear dynamic characteristics of normal subjects were measured, and an attempt was made to clarify the relationship between EOAEs and middle-ear dynamic characteristics. It is concluded that EOAEs are detected most distinctly at the middle-ear resonance frequency and that EOAEs are most detectable in normal subjects whose middle-ear mobility is moderate.

Acoustic Stimulation↗
PubMedDate not supplied

Effect of middle ear on otoacoustic emissions.

Otoacoustic emissions (OAEs) are believed to originate from outer hair cell movement and are considered to be transmitted to the external auditory meatus through the middle ear in a retrograde fashion. Therefore, the effect of the middle-ear on OAEs seems to be large. However, few investigations of middle-ear effects on OAEs have been published because no apparatus that can measure the middle-ear dynamic characteristics is easily available except a conventional impedance meter. We developed a sweep frequency impedance meter (SFI) which gives us much more information on middle-ear dynamic characteristics than a conventional impedance meter. In this paper, applying SFI and 3 OAE measuring apparatuses, middle-ear dynamic characteristics and different sorts of OAEs of human subjects and guinea pigs were measured, and an attempt was made to examine the relationship between OAEs and middle-ear dynamic characteristics from various aspects. It is concluded that frequency characteristics of OAEs correlate well with middle-ear frequency characteristics; and middle-ear effect on OAEs must be taken into account when OAE data are analyzed.

Acoustic Stimulation↗
PubMedDate not supplied

Activation of autologous or HLA-identical sibling cytotoxic T lymphocytes by blood derived dendritic cells pulsed with tumor cell extracts.

This study describes the effect of dendritic cells (DC) pulsed with tumor cell extracts on the induction and activation of autologous and HLA-identical sibling tumor cell specific cytotoxic T lymphocytes (CTL). The subjects of the study were patients with hematological malignancies (acute myeloid leukemia, acute lymphoblastic leukemia, and multiple myeloma), and stem cell transplant donors. Although lymphocytes primed with non-pulsed DC did not show definite cytotoxic activity against autologous or HLA-identical sibling patient tumor cells, both autologous and HLA-identical sibling CTL activated by DC pulsed with tumor cell extracts demonstrated markedly significant killing activity against tumor cells in the fashion of higher cytotoxicity with the increase of effector:target ratio (p<0.05). These findings reveal that DC pulsed with tumor cell extracts could be efficiently applicable in anti-tumor immunotherapy for patients with hematological malignancies.

Adult↗
PubMedDate not supplied

[Treatment of metastatic seminoma by chemotherapy.: an experience].

PURPOSE: To describe the outcome of chemotherapy using cisplatin-based regimen, and experimental combination with carboplatin and ifosfamide to treat advanced seminoma. METHODS: From 1981 to Jan. 1999, 15 patients with Stage IIA, IIB, IIIA or IIIC metastatic seminoma and one patient with lung disease, who suffered a relapse of his primary mediastinal lesion were treated. Three of these patients had relapsed, following surveillance for Stage I testicular cancer, and another had received prophylactic radiotherapy to the retroperitoneal lymph nodes in advance. The first patient's regimen consisted of cisplatin and cyclophosphamide. Since 1983, cases have been treated with the same regimen as that used to treat non-seminomatous germ-cell tumors; cisplatin/vinblastine/bleomycin (PVB); cisplatin/vinblastine/actinomycin D/cyclophosphamide/bleomycin (VAB-6); cisplatin/etoposide/bleomycin (BEP). From 1993, six patients with non-bulky metastatic seminoma participated in a trial involving 3 courses of carboplatin (400 mg/m2) and ifosfamide (2,000 mg/m2, 3 days). RESULTS: Of the entire group, 10 patients (62.5%) achieved a CR after chemotherapy alone. Four cases who received radiation, following chemotherapy, produced CR. Surgical resection of residual tumors were performed on 2 patients. Resected tumors were fibrous and no evidence of malignancy. All those individuals who participated in this study, are alive and disease-free today, from 11 months to 18 years. Carboplatin and ifosfamide demonstrated only mild toxicity, during a 4-week cycle, with subjects being treated on an outpatient basis. CONCLUSION: As expected, the type of chemotherapy we used, to treat non-seminomatous germ-cell tumors proved to be highly effective for seminomatous types, as well. Carboplatin and ifosfamide performed well and safe, in the treatment of non-bulky metastatic seminoma. Comparative studies of long-term treatment results and QOL, using either radiotherapy or low-toxicity chemotherapy for Stage IIA disease should be undertaken.

Adult↗
PubMedDate not supplied

Effect of mechanical properties of resin composites on the efficacy of the dentin bonding system.

This study determined the relationship between marginal adaptation to dentin cavity preparations, tensile bond strength of the restorations, and mechanical properties of the composites. Contraction gaps, tensile bond strengths, flexural strengths, and Young's modulus of eight commercial resin composites were determined. Eight resin composites (Clearfil AP-X, Estelite, Estio LC, Litefil II-A, Prodigy, Progress, Silux Plus, and Z-100) were applied to dentin cavities or flat dentin surfaces mediated with an experimental dentin bonding system consisting of 0.5 M EDTA dentin conditioner, priming with 35% glyceryl mono-methacrylate solution, and a commercial dentin bonding agent application (Clearfil Photo Bond). The contraction gap of the resin composite in a cylindrical dentin cavity was prevented completely for three of the resin composites tested (Clearfil AP-X, Estelite, and Silux Plus). The measured tensile bond strength correlated significantly not only with the tensile strength (r2 = 0.506; 0.01 < P < 0.05), but also with the flexural strength (r2 = 0.871; P < 0.001) and Young's modulus (r2 = 0.712; 0.001 < P < 0.01) of the composites, whereas the contraction gap did not correlate significantly with the measured tensile bond strength, the tensile strength, the flexural strength, or Young's modulus (P > 0.05). However, the results did indicate that the higher tensile bond strengths measured in the traditional test may be related to the higher mechanical properties of the resin composites because of the number of specimens that exhibited cohesive failure.

Analysis of Variance↗
PubMedDate not supplied

Effect of sodium benzylideneascorbate on chemically-induced tumors in rats.

Intravenous administration of sodium benzylideneascorbate (SBA) dose-dependently induced degeneration (vacuolar and eosinophilic degeneration and cell shrinkage and nuclear condensation, which are characteristic of apoptotic cell death) of 3'-methyl-4-dimethylaminoazobenzene-induced rat hepatocellular carcinoma. SBA did not significantly induce lymphocyte infiltration and fibrosis in the liver, nor damage the gross morphology of kidney and spleen cells. SBA failed to stimulate the production of tumor necrosis factor and interleukin-1 beta in both in vitro and in vivo systems. These results may suggest a direct antitumor action of SBA via induction of apoptosis in the tumor. However, SBA did not significantly affect the doubling time, or the extent of invasion and differentiation of dimethylhydrazine-induced colon carcinoma in rats. These data suggest that the conditions of SBA administration should be re-established for each tumor sample to produce maximum antitumor activity.

Animals↗