Biomedical subjects

Kenji Yamada

Publications and source records attributed to Kenji Yamada.

At least 19 recordsLinked to original sources

PubMed2006

Single center experience of treatment of Ewing's family of tumors in Japan.

BACKGROUND: Japanese patients with the Ewing's family of tumors (EFTs) reportedly have a worse prognosis than their European Caucasian counterparts. However, details of the prognosis of Japanese EFT patients have not been clearly defined because of the lack of representative clinical studies of the results of contemporary, multidisciplinary treatments. METHODS: The present study analyzed the outcome of 19 consecutive patients with EFTs who were treated with a multidisciplinary approach at a single institution. Combination chemotherapy consisting of vincristine, actinomycin D, Adriamycin (doxorubicin), and ifosfamide was administered as induction chemotherapy. Local therapy was administered individually, considering various factors, with the ultimate aim of complete surgical resection. Nine patients who satisfied the inclusion criteria received high-dose chemotherapy with peripheral blood stem cell rescue as a consolidation treatment. RESULTS: The 3-year overall and event-free survival rates were 62% and 51%, respectively, which were comparable to results from Western countries, although the number of subjects was too small to allow definitive conclusions to be drawn. CONCLUSIONS: There is a clear need to investigate the results of treatment of Japanese EFT patients in a multiinstitutional, prospective clinical study.

Adolescent↗

PubMed2006

Proximal-type epithelioid sarcoma of the perineum: calling attention of urologists.

A subcutaneous mass in the perineum of a middle-aged man was excised and pathologically diagnosed at first as 'undifferentiated carcinoma' of unknown origin, which recurred 2 years later without any metastasis. Further histological evaluation ultimately established a correct diagnosis of 'proximal-type epithelioid sarcoma', a variant of rare epithelioid sarcoma. This type of tumor may confuse pathologists because its histological characteristics resemble undifferentiated carcinoma or malignant rhabdoid tumor. Frequent immunoreactivity of CD34, in addition to expression of keratins, epithelial membrane antigen and vimentin, provides strong support for the diagnosis of this rare neoplasm. Urologists should be aware that this sarcoma commonly occurs in the genital regions.

Biomarkers, Tumor↗

PubMed2006

Long-term monitoring of the succession of a microbial community in activated sludge from a circulation flush toilet as a closed system.

The microbial diversity and community succession of a circulation flush toilet were investigated by terminal restriction fragment length polymorphism and cloning analyses. Clonal libraries of 16S rRNA gene on day 3 and day 127 were constructed. On day 3, 102 clones were sequenced; Proteobacteria and Bacteroidetes accounted for 27% and 45%, respectively. On day 127, Proteobacteria had increased to 43% and Bacteroidetes had decreased to 26% of a total of 100 clones. Terminal restriction fragment length polymorphism peaks were identified by in silico analysis of clone libraries. The relative abundances of Nitrosomonas increased from 1% to 6% with commencement of nitrification and denitrification. Similarly, the relative abundance of terminal restriction fragments generated from Xanthomonas increased from 3% to 10%. Therefore, these bacteria could play a prominent role in this process. To reveal the relationship between stability of the microbial community and performance of the system, microbial community succession was visualized by multidimensional scaling analysis. The microbial community structure changed markedly, particularly during the start-up period of the system. The plots then became stable after the start of nitrification and denitrification. This result suggests that the succession of microbial community structure had a correlation with the performance of the system.

Bacteroidetes↗

PubMed2006

[A case of multiple pyomyositis after chemotherapy for lung cancer].

We here describe a case of multiple pyomyositis in a 62-year-old man who had systemic chemotherapy for recurrent lung cancer. His initial symptoms consisted of fever and general fatigue, followed by progressive pain and swelling in his extremities, which mimicked deep venous thrombosis along with bacterial infection. He was admitted to the hospital for intravenous administration of antibiotics. MRI appeared very useful to find the intramuscular fluid collections with circumferential inflammatory changes, which confirmed diagnosis of the multiple pyomyositis. Surgical drainage as well as intravenous administration of antibiotics worked very well and improved clinical symptoms in a few weeks after the treatments. He could resume normal activities with minimum functional impairments in the extremities. Pyomyositis should be kept in mind as one of the adverse effects after chemotherapy for malignant tumors.

Adenocarcinoma↗

PubMed2005

Identification of NADH dehydrogenase 1 alpha subcomplex 5 capable to transform murine fibroblasts and overexpressed in human cervical carcinoma cell lines.

The human papillomavirus (HPV) E6 and E7 proteins play essential roles in HPV-associated cervical carcinogenesis. However, cells transformed by E6 or E7 rarely grow into tumors in nude mice, indicating that the carcinogenesis involves additional molecular events. The highly efficient retroviral cDNA expression system derived from HeLa cells identified two cDNA species coding NADH dehydrogenase 1 alpha subcomplex 5 (NDUFA5) and zinc finger protein 9 (ZNF9), exhibiting the potential to transform murine fibroblast cell line, NIH3T3. The real-time RT-PCR analysis revealed that the expressions of the NDUFA5 mRNA, but not the ZNF9 mRNA level, were significantly up-regulated in all the tested cell lines derived from HPV-positive cervical cancer, HeLa, SW576, and CaSKi. The NDUFA5 expression may contribute to the multi-step carcinogenesis in human cervical cancer.

3T3 Cells↗

PubMed2005

Vacuolar processing enzyme is essential for mycotoxin-induced cell death in Arabidopsis thaliana.

Some compatible pathogens secrete toxins to induce host cell death and promote their growth. The toxin-induced cell death is a pathogen strategy for infection. To clarify the executioner of the toxin-induced cell death, we examined a fungal toxin (fumonisin B1 (FB1))-induced cell death of Arabidopsis plants. FB1-induced cell death was accompanied with disruption of vacuolar membrane followed by lesion formation. The features of FB1-induced cell death were completely abolished in the Arabidopsis vacuolar processing enzyme (VPE)-null mutant, which lacks all four VPE genes of the genome. Interestingly, an inhibitor of caspase-1 abolished FB1-induced lesion formation, as did a VPE inhibitor. The VPE-null mutant had no detectable activities of caspase-1 or VPE in the FB1-treated leaves, although wild-type leaves had the caspase-1 and VPE activities, both of which were inhibited by a caspase-1 inhibitor. gammaVPE is the most essential among the four VPE homologues for FB1-induced cell death in Arabidopsis leaves. Recombinant gammaVPE recognized a VPE substrate with Km = 30.3 microm and a caspase-1 substrate with Km = 44.2 microm, which is comparable with the values for mammalian caspase-1. The gammaVPE precursor was self-catalytically converted into the mature form exhibiting caspase-1 activity. These in vivo and in vitro analyses demonstrate that gammaVPE is the proteinase that exhibits a caspase-1 activity. We show that VPE exhibiting a caspase-1 activity is a key molecule in toxin-induced cell death. Our findings suggest that a susceptible response of toxin-induced cell death is caused by the VPE-mediated vacuolar mechanism similar to a resistance response of hypersensitive cell death (Hatsugai, N., Kuroyanagi, M., Yamada, K., Meshi, T., Tsuda, S., Kondo, M., Nishimura, M., and Hara-Nishimura, I. (2004) Science 305, 855-858).

Animals↗

PubMed2005

Asparagine endopeptidase is not essential for class II MHC antigen presentation but is required for processing of cathepsin L in mice.

Class II MHC molecules survey the endocytic compartments of APCs and present antigenic peptides to CD4 T cells. In this context, lysosomal proteases are essential not only for the generation of antigenic peptides but also for proteolysis of the invariant chain to allow the maturation of class II MHC molecules. Recent studies with protease inhibitors have implicated the asparagine endopeptidase (AEP) in class II MHC-restricted Ag presentation. We now report that AEP-deficient mice show no differences in processing of the invariant chain or maturation of class II MHC products compared with wild-type mice. In the absence of AEP, presentation to primary T cells of OVA and myelin oligodendrocyte glycoprotein, two Ags that contain asparagine residues within or in proximity to the relevant epitopes was unimpaired. Cathepsin (Cat) L, a lysosomal cysteine protease essential for the development to CD4 and NK T cells, fails to be processed into its mature two-chain form in AEP-deficient cells. Despite this, the numbers of CD4 and NK T cells are normal, showing that the single-chain form of Cat L is sufficient for its function in vivo. We conclude that AEP is essential for processing of Cat L but not for class II MHC-restricted Ag presentation.

Animals↗

PubMed2005

A vacuolar processing enzyme, deltaVPE, is involved in seed coat formation at the early stage of seed development.

Vacuolar processing enzyme (VPE) is a Cys proteinase responsible for the maturation of vacuolar proteins. Arabidopsis thaliana deltaVPE, which was recently found in the database, was specifically and transiently expressed in two cell layers of the seed coat (ii2 and ii3) at an early stage of seed development. At this stage, cell death accompanying cell shrinkage occurs in the ii2 layer followed by cell death in the ii3 layer. In a deltaVPE-deficient mutant, cell death of the two layers of the seed coat was delayed. Immunocytochemical analysis localized deltaVPE to electron-dense structures inside and outside the walls of seed coat cells that undergo cell death. Interestingly, deltaVPE in the precipitate fraction from young siliques exhibits caspase-1-like activity, which has been detected in various types of plant cell death. Our results suggest that, at the early stage of seed development, deltaVPE is involved in cell death of limited cell layers, the purpose of which is to form a seed coat.

Arabidopsis↗

PubMed2005

Endosomal proteases facilitate the fusion of endosomes with vacuoles at the final step of the endocytotic pathway.

The mechanism by which plasma membrane proteins are transported to vacuoles for degradation has not been well characterized in plants. To clarify how plasma membrane proteins are degraded, we monitored the endocytotic pathway in tobacco suspension-cultured BY-2 cells with a fluorescent endocytosis marker, FM4-64. Because of the efficient and rapid delivery of endosomes to the vacuoles, endosomes were scarcely detectable. Interestingly, we found that E-64d, an inhibitor of papain family proteases, caused the accumulation of a large number of endosomes in the cells under the sucrose-starved condition. This result indicates that E-64d attenuates the fusion of endosomes with vacuoles. We identified two papain homologues, which are localized in the endosomes, with a biotinylated inhibitor. We designated them as endosome-localized papains (ENPs). Immunofluorescent analysis revealed that vacuolar sorting receptor, a marker of prevacuolar compartment (PVC), was localized in the endosomes. This result and their acidic nature show that the endosomes correspond to PVC. These results suggest that ENPs facilitate the final step in the vacuolar trafficking pathway under the sucrose-starved condition. We further examined the effects of E-64d on two transgenic Arabidopsis plants that constitutively express a fusion protein composed of green fluorescent protein (GFP) and a plasma membrane protein (GFP-PIP2a or GFP-LTI6b). GFP fluorescence was observed on the plasma membrane of root cells in these transgenic plants. Treatment with E-64d induced the accumulation of GFP-fluorescent endosomes and inhibited the degradation of these fusion proteins. No GFP fluorescence was observed in vacuoles in E-64d-treated transgenic plants. Taken together, these results suggest that endosomal proteases are required for the fusion of endosomes with vacuoles at the final step in the endocytotic pathway for degradation of plasma membrane proteins in plants.

Arabidopsis↗

PubMed2005

Effects of inhaling the vapor of Lavandula burnatii super-derived essential oil and linalool on plasma adrenocorticotropic hormone (ACTH), catecholamine and gonadotropin levels in experimental menopausal female rats.

The effects of inhaling the vapor of Lavandula burnatii super-derived essential oil and one of the main components of lavender oil, linalool on plasma adrenocorticotropic hormone (ACTH), catecholamine and gonadotropin levels in menopausal model rats under ether-inhalation were studied. The increased plasma ACTH levels induced by ether-inhalation tended to decrease by pre-inhalation of Lavandula burnetii super and linalool vapor was induced the decrease of ACTH level. The decrease in adrenaline, noradrenaline and dopamine levels induced by ether-inhalation tended to recover, especially, the dopamine level significantly recovered to the normal level by the inhalation of Lavandula burnetii super and linalool vapor. However, the increased plasma gonadotropin levels in ovariectomized retired female rats (menopausal model rats) was significantly decreased by the inhalation of linalool. These results suggest that lavender oil or one of the main components, linalool may contribute to relieving tension and may be applicable to the treatment of menopausal disorders in human beings.

Acyclic Monoterpenes↗

PubMed2004

An alternative transcript derived from the trio locus encodes a guanosine nucleotide exchange factor with mouse cell-transforming potential.

By screening cDNA expression libraries derived from fresh leukemic cells of adult T-cell leukemia for the potential to transform murine fibroblasts, NIH3T3, we have identified a novel transforming gene, designated Tgat. Expression of Tgat in NIH3T3 resulted in the loss of contact inhibition, increase of saturation density, anchorage-independent growth in a semisolid medium, tumorigenicity in nude mice, and increased invasiveness. Sequence comparison revealed that an alternative RNA splicing of the Trio gene was involved in the generation of Tgat. The Tgat cDNA encoded a protein product consisting of the Rho-guanosine nucleotide exchange factor (GEF) domain of a multifunctional protein, TRIO, and a unique C-terminal 15-amino acid sequence, which were derived from the exons 38-46 of the Trio gene and a novel exon located downstream of its last exon (exon 58), respectively. A Tgat mutant cDNA lacking the C-terminal coding region preserved Rho-GEF activity but lost the transforming potential, indicating an indispensable role of the unique sequence. On the other hand, treatment of Tgat-transformed NIH3T3 cells with Y-27632, a pharmacological inhibitor of Rho-associated kinase, abrogated their transforming phenotypes, suggesting the coinvolvement of Rho-GEF activity. Thus, alternative RNA splicing, resulting in the fusion protein with the Rho-GEF domain and the unique 15 amino acids, is the mechanism generating the novel oncogene, Tgat.

3T3 Cells↗

PubMed2004

A plant vacuolar protease, VPE, mediates virus-induced hypersensitive cell death.

Programmed cell death (PCD) in animals depends on caspase protease activity. Plants also exhibit PCD, for example as a response to pathogens, although a plant caspase remains elusive. Here we show that vacuolar processing enzyme (VPE) is a protease essential for a virus-induced hypersensitive response that involves PCD. VPE deficiency prevented virus-induced hypersensitive cell death in tobacco plants. VPE is structurally unrelated to caspases, although VPE has a caspase-1 activity. Thus, plants have evolved a regulated cellular suicide strategy that, unlike PCD of animals, is mediated by VPE and the cellular vacuole.

Apoptosis↗

PubMed2004

Reconstruction of a high-resolution image on a compound-eye image-capturing system.

The authors have proposed an architecture for a compact image-capturing system called TOMBO (thin observation module by bound optics), which uses compound-eye imaging for a compact hardware configuration [Appl. Opt. 40, 1806 (2001)]. The captured compound image is decomposed into a set of unit images, then the pixels in the unit images are processed with digital processing to retrieve the target image. A new method for high-resolution image reconstruction, called a pixel rearrange method, is proposed. The relation between the target object and the captured signals is estimated and utilized to rearrange the original pixel information. Experimental results show the effectiveness of the proposed method. In the experimental TOMBO system, the resolution obtained is four times higher than that of the unit image that did not undergo reconstruction processing.

Journal Article↗

PubMed2004

Bimodal fingerprint capturing system based on compound-eye imaging module.

A compact imaging system called TOMBO (Thin Observation Module by Bound Optics) is proposed in which a microlens array is used for thin hardware configuration. This paper describes a fingerprint-capturing module as an application of the TOMBO. Experimental results by the TOMBO prototype system are shown to clarify the applicability of the TOMBO to the fingerprint capturing. Different types of biometrics, i.e., fingerprint and face images, are captured by the same hardware, which shows the extendability of the system for multimodal identification.

Journal Article↗

PubMed2004

Endoplasmic reticulum-resident proteins are constitutively transported to vacuoles for degradation.

Soluble endoplasmic reticulum (ER)-resident proteins have very long lives because of their ER residency. This residency depends largely on ER-retrieval signals at their C-terminus. We examined the long-term destiny of endogenous ER-resident proteins, a lumenal binding protein (BiP) and a protein disulfide isomerase (PDI), with cultured cells of Arabidopsis. ER residents, in contrast to vacuolar proteinases, were considerably degraded in cells at the stationary phase. A subcellular fractionation analysis suggested that ER residents were transported into the vacuoles, which accumulated the residents lacking the ER-retrieval signals. We showed that the PDI located in the vacuoles had high mannose glycans, but not complex glycans, which suggested that the ER resident was transported to the vacuoles independent of the medial/trans-Golgi complex. To visualize the pathway of transport of ER-resident proteins, tobacco BY-2 cells were transformed with a chimeric gene encoding an ER-targeted green fluorescent protein (30 kDa GFP-HDEL). In the transformed cells at the stationary phase, GFP fluorescence was observed in the vacuoles. A subcellular fractionation revealed that a trimmed form of 27 kDa GFP was localized in the vacuoles. Treatment with E-64d, an inhibitor of papain-type cysteine proteinases that inhibits the degradation of GFP in the vacuoles, resulted in a stable accumulation of 27 kDa GFP in the vacuoles, even in the logarithmic phase. Our results suggest that endogenous ER residents are transported constitutively to the vacuoles by bypassing the Golgi complex and are then degraded.

Arabidopsis↗

PubMed2004

Effects of benzyl glucoside and chlorogenic acid from Prunus mume on adrenocorticotropic hormone (ACTH) and catecholamine levels in plasma of experimental menopausal model rats.

To investigate the effectiveness of benzyl beta-D-glucopyranoside (BG) and chlorogenic acid (CA), the constituents of the fruit of Prunus mume, for relieving tension in experimental menopausal model rats (M-rats) caused by ether stress, the effects of BG and CA on adrenocorticotropic hormone (ACTH) and catecholamine (adrenaline, noradrenaline, and dopamine) levels were examined in the plasma of M-rats. Caffeic acid, quinic acid, and rosmarinic acid, which are compounds structurally related to CA, were also examined. BG obviously recovered catecholamine levels decreased by ether stress and increased dopamine to high levels. On the other hand, CA significantly decreased the ACTH level increased by ether stress and showed the greatest effect of all compounds. These results suggest that BG and CA may contribute to relieving the tension in M-rats caused by ether stress.

Adrenocorticotropic Hormone↗

PubMed2004

[A case of retroperitoneal neuroblastoma in an adult with extensive bone marrow metastasis].

We present a case of retroperitoneal neuroblastoma in a 27-year-old male with extensive bone marrow metastasis at the first presentation. After the simple excision of the tumor, adjuvant multi-drug chemotherapy, consisting of vincristine, actinomycin-D, ifosfamide, doxorubicin, carboplatin and etoposide, was carried out for 17 months, leading to complete remission. Ten months after completion of the chemotherapy, the tumor recurred with bone marrow metastasis. He further developed thoracic vertebral metastases resulting in paraplegia, and died of the disease 41 months after the presentation. The clinical course of this case, with its emphases especially on the effect of the chemotherapy, is described in this report. Since the clinical characteristics and treatment strategies for adult neuroblastoma have not yet been well established, they remain to be investigated in detail.

Adult↗

PubMed2003

The slow wound-response of gammaVPE is regulated by endogenous salicylic acid in Arabidopsis.

Vacuolar processing enzyme (VPE) is a cysteine protease responsible for the maturation of various vacuolar proteins in higher plants. The Arabidopsis thaliana (L.) Heynh. gammaVPE gene, encoding a VPE homologue, is slowly up-regulated in both local and systemic leaves in response to wounding. To clarify the activation mechanism of gammaVPE, we examined the accumulation of gammaVPE mRNA after hormone treatments or after wounding in wild-type and various mutant plants of Arabidopsis. Both ethylene and jasmonic acid (JA) are known as signal molecules that activate the wound-responsive genes. However, treatment with exogenous JA had little effect on the gammaVPE response, although JA activated the vegetative storage protein ( VSP) gene, a typical wound-responsive gene. Wounding activated gammaVPE even in two ethylene-insensitive plants (etr1-1 and ein2-1). Thus, the wound-induced expression of gammaVPE was independent of ethylene and JA. We found that the wound-induced expression of gammaVPE was reduced in two SA-deficient plants (pad4-1 and NahG), while the wound-induced expression of VSP increased in these mutants. Appreciable accumulation of SA was not observed in either the local or systemic leaves after wounding. These results suggest that endogenous SA enhances the wound-induced expression of gammaVPE and attenuates the wound-induced expression of VSP, although SA is not a wound-signal that directly activates these genes.

Arabidopsis↗