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Biomedical subjects

T Kamura

Publications and source records attributed to T Kamura.

At least 19 recordsLinked to original sources
PubMed2003

Prenatal diagnosis of sustained bradycardia with 1 : 1 atrioventricular conduction.

OBJECTIVES: The aims of this study were to elucidate the clinical course of fetal bradycardia with 1 : 1 atrioventricular conduction, and to discuss the optimal management of affected fetuses in the second and third trimesters of pregnancy. METHODS: The hospital records of five fetuses with the diagnosis of bradycardia (100 bpm) with 1 : 1 atrioventricular conduction between 1981 and 2000 in our institution were reviewed. Atrioventricular conduction was evaluated by simultaneous M-mode echocardiographic tracing of the atria and the ventricles. RESULTS: The gestational ages at referral ranged from 19 to 36 (median, 25) weeks, and fetal heart rates ranged from 60 to 80 (median, 80) bpm. Postnatal electrocardiography revealed sinus bradycardia in four (two of which were siblings) of the five cases, and junctional rhythm in the remaining case. Two fetuses with congenital heart defects (CHDs) were delivered by Cesarean section but died postnatally. The three fetuses without CHDs were delivered vaginally and have survived to date for 6, 8 and 15 years. CONCLUSIONS: Fetal bradycardia with 1 : 1 atrioventricular conduction caused by sustained sinus bradycardia or wandering pacemaker is an important type of fetal arrhythmia. Further investigations with a larger number of cases are required to determine the risk factors for predicting the outcome of affected fetuses.

Bradycardia↗
PubMed2002

Enlarged bronchial arteries in a fetus with transposition of the great arteries and intact ventricular septum.

Enlarged bronchial arteries are associated in some patients with transposition of the great arteries and intact ventricular septum. The etiology of these enlarged bronchial arteries is not yet known. In this report, we describe a case of TGA/IVS in which enlarged bronchial arteries were demonstrated from the prenatal period. The arteriogram at one year after arterial switch repair demonstrated enlarged bronchial arteries. This prenatal information may be useful for deciding on a strategy for postnatal treatment and counseling the family members.

Angiography↗
PubMed2002

UDP-Gal: betaGlcNAc beta1, 3-galactosyltransferase, polypeptide 3 (GALT3) is a tumour antigen recognised by HLA-A2-restricted cytotoxic T lymphocytes from patients with brain tumour.

Patient prognosis in the case of malignant brain tumours is generally poor, despite significant improvements in the early detection of the tumours, and thus the development of new treatment modalities is needed. One of the most prominent modalities is specific immunotherapy, for which the elucidation of antigenic molecules of malignant brain tumours recognized by T cells is essential. We report here a gene, UDP-Gal: betaGlcNAc beta1, 3-galactosyltransferase, polypeptide 3, encoding three epitope peptides recognised by tumor-reactive cytotoxic T lymphocytes in an HLA-A2-restricted manner. Two of the three peptides possessed an ability to induce HLA-A2-restricted and tumour-reactive cytotoxic T lymphocytes from peripheral blood mononuclear cells of patients with brain tumours. These peptides may be useful in the peptide-based specific immunotherapy for patients with malignant brain tumours.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed2002

Detection of peptide-specific CTL-precursors in peripheral blood lymphocytes of cancer patients.

Development of therapeutic vaccines is one of the major areas of tumour immunotherapy today. However, clinical trials of peptide-based cancer vaccines have rarely resulted in tumour regression. This failure might be due to an insufficient induction of cytotoxic T lymphocytes in the current regimes, in which cytotoxic T lymphocytes-precursors in pre-vaccination peripheral blood mononuclear cells are not measured. Initiation of immune-boosting through vaccination could be better than that of immune-priming with regard to induction of prompt and strong immunity. If this is also the case for therapeutic vaccines, pre-vaccination measurement of peptide-specific cytotoxic T lymphocytes-precursors will be important. In the present study, we investigated whether cytotoxic T lymphocytes-precursors reacting to 28 kinds of peptides of vaccine candidates (13 and 15 peptides for HLA-A24(+) and HLA-A2(+) patients, respectively) were detectable in pre-vaccination peripheral blood mononuclear cells of 80 cancer patients. Peptide-specific cytotoxic T lymphocytes-precursors were found to be detectable in peripheral blood mononuclear cells of the majority of cancer patients (57 out of 80 cases, 71%). The mean numbers of positive peptides were 2.0 peptides per positive case. Peripheral blood mononuclear cells incubated with positive peptides, not with negative peptides, showed significant levels of HLA-class-I-restricted cytotoxicity to cancer cells. The profiles of positive peptides entirely varied among patients, and were not influenced by the cancer origin. These results may provide a scientific basis for the development of a new approach to cancer immunotherapy, e.g.) cytotoxic T lymphocytes-precursor-oriented peptide vaccine.

Antigens, Neoplasm↗
PubMed2002

Recognition of ADP-ribosylation factor 4-like by HLA-A2-restricted and tumor-reactive cytotoxic T lymphocytes from patients with brain tumors.

Although specific immunotherapy is one candidate treatment of brain tumor, the molecular basis of T-cell-mediated recognition of brain tumors has not yet been elucidated. In this study, we tried to identify brain tumor antigens using HLA-A2-restricted and tumor-reactive cytotoxic T lymphocytes (CTLs). As an HLA-A2-restricted OK-CTL line contained CTLs capable of responding to HLA-A2+ malignant glioma cells, this cell line was used for identification of brain tumor antigens. After screening a cDNA library from brain tumor cells, this CTL line was found to produce interferon (IFN)-gamma when cultured with COS-7 cells, which were cotransfected with both a cDNA clone (clone 1) and HLA-A0207 cDNA. Data base searches indicated that the clone 1 was 98% identical to that of the human ADP-ribosylation factor 4-like (ARF4L). Two peptides, ARF4L 15-24 and ARF4L 69-77, possessed the ability to induce HLA-A2-restricted and tumor-reactive CTLs from peripheral blood mononuclear cells of patients with brain tumors. Although ARF4L seemed to be ubiquitously expressed at the mRNA level, ARF4L-reactive CTLs failed to exhibit cytotoxicity against normal lymphoid blasts. These results indicate that these two ARF4L peptides could be targets for immunotherapy of HLA-A2+ patients with brain tumors.

ADP-Ribosylation Factors↗
PubMed2002

The possible intraspousal transmission of HCV in terms of lichen planus.

Lichen planus (LP), common mucocutaneous disorder, involves not only oral mucosa and skin but genitalia membrane. LP is frequently seen in patients with HCV infection. This study evaluated patients with HCV-associated oral lichen planus (OLP) for vulvar and vaginal LP involvement, and the possible intraspousal transmission of HCV. We examined a total of 24 female Japanese patients with OLP for genitalia LP: 14 OLP-HCV positive and 10 OLP-HCV negative. All subjects were evaluated for genital LP by a gynecologist. All 24 subjects and 10 of the husbands were tested for anti-HCV and serum HCV RNA. Vulvar LP was observed in 10 (41.7%) of 24 patients with OLP. Vulvar LP in 14 (OLP-HCV positive) and 10 patients (OLP-HCV negative) were observed in 42.9 and 40%, respectively. There were no significant differences (age, sites of OLP, blood transfusion, HCV infection, and degree of liver diseases) between the vulvar LP and non-vulvar LP patients. Two spouses of 10 married couples were shown to be infected with HCV. In one couple with HCV infection, the wife and husband had also erosive OLP, the wife had erosive vulvar LP. In conclusion, the majority of OLP patients suffered from genitalia LP in Japan. Clinicians should follow the OLP patients with sufficient attention to the presence of extraoral manifestations. These data may suggest the occurrence of intraspousal transmission of HCV through erosive vulvar LP.

Adult↗
PubMed2001

Degradation of p53 by adenovirus E4orf6 and E1B55K proteins occurs via a novel mechanism involving a Cullin-containing complex.

Although MDM2 plays a major role in regulating the stability of the p53 tumor suppressor protein, other poorly understood MDM2-independent pathways also exist. Human adenoviruses have evolved strategies to regulate p53 function and stability to permit efficient viral replication. One mechanism involves adenovirus E1B55K and E4orf6 proteins, which collaborate to target p53 for degradation. To determine the mechanism of this process, a multiprotein E4orf6-associated complex was purified and shown to contain a novel Cullin-containing E3 ubiquitin ligase that is (1) composed of Cullin family member Cul5, Elongins B and C, and the RING-H2 finger protein Rbx1(ROC1); (2) remarkably similar to the von Hippel-Lindau tumor suppressor and SCF (Skp1-Cul1/Cdc53-F-box) E3 ubiquitin ligase complexes; and (3) capable of stimulating ubiquitination of p53 in vitro in the presence of E1/E2 ubiquitin-activating and -conjugating enzymes. Cullins are activated by NEDD8 modification; therefore, to determine whether Cullin complexes are required for adenovirus-induced p53 degradation, studies were conducted in ts41 Chinese hamster ovary cells that are temperature sensitive for the NEDD8 pathway. E4orf6/E1B55K failed to induce the degradation of p53 at the nonpermissive temperature. Thus, our results identify a novel role for the Cullin-based machinery in regulation of p53.

Adenovirus E1B Proteins↗
PubMed2001

Degradation of p27(Kip1) at the G(0)-G(1) transition mediated by a Skp2-independent ubiquitination pathway.

Targeting of the cyclin-dependent kinase inhibitor p27(Kip1) for proteolysis has been thought to be mediated by Skp2, the F-box protein component of an SCF ubiquitin ligase complex. Degradation of p27(Kip1) at the G(0)-G(1) transition of the cell cycle has now been shown to proceed normally in Skp2(-/-) lymphocytes, whereas p27(Kip1) proteolysis during S-G(2) phases is impaired in these Skp2-deficient cells. Degradation of p27(Kip1) at the G(0)-G(1) transition was blocked by lactacystin, a specific proteasome inhibitor, suggesting that it is mediated by the ubiquitin-proteasome pathway. The first cell cycle of stimulated Skp2(-/-) lymphocytes appeared normal, but the second cycle was markedly inhibited, presumably as a result of p27(Kip1) accumulation during S-G(2) phases of the first cell cycle. Polyubiquitination of p27(Kip1) in the nucleus is dependent on Skp2 and phosphorylation of p27(Kip1) on threonine 187. However, polyubiquitination activity was also detected in the cytoplasm of Skp2(-/-) cells, even with a threonine 187 --> alanine mutant of p27(Kip1) as substrate. These results suggest that a polyubiquitination activity in the cytoplasm contributes to the early phase of p27(Kip1) degradation in a Skp2-independent manner, thereby promoting cell cycle progression from G(0) to G(1).

Acetylcysteine↗
PubMed2001

Conservative therapy for adenocarcinoma and atypical endometrial hyperplasia of the endometrium in young women: central pathologic review and treatment outcome.

Thirty-nine patients with endometrioid adenocarcinoma (EA) and atypical hyperplasia (AH) of the endometrium who received conservative treatment to preserve fertility were collected from member institutions of the Japan Gynecologic Oncology Study Group. Twenty-nine and ten were originally diagnosed with EA without myometrial invasion and AH, respectively. We performed a central pathological review to make definite diagnoses, and the diagnosis of EA in 29 cases was changed to AH in ten, complex hyperplasia in three and atypical polypoid adenomyoma in three, and AH in ten was changed to EA in one and simple hyperplasia in one. Nine of 12 women (75%) with EA and 15 of 18 women (83%) with AH had an initial response to medroxyprogesterone acetate (MPA) treatment. Two of nine responders with EA later developed relapse, and one of them had metastasis to the left obturator lymph node. Two became pregnant, and one delivered one full-term infant. One of the responders with AH had a relapse in the endometrium. Five became pregnant, and four delivered four normal infants. The young women with endometrial carcinoma localized in the endometrium who wish to preserve fertility may be treated as successfully with MPA as those with AH.

Adenocarcinoma↗
PubMed2001

Muf1, a novel Elongin BC-interacting leucine-rich repeat protein that can assemble with Cul5 and Rbx1 to reconstitute a ubiquitin ligase.

The heterodimeric Elongin BC complex has been shown to interact in vitro and in mammalian cells with a conserved BC-box motif found in a growing number of proteins including RNA polymerase II elongation factor Elongin A, SOCS-box proteins, and the von Hippel-Lindau (VHL) tumor suppressor protein. Recently, the VHL-Elongin BC complex was found to interact with a module composed of Cullin family member Cul2 and RING-H2 finger protein Rbx1 to reconstitute a novel E3 ubiquitin ligase that activates ubiquitylation by the E2 ubiquitin-conjugating enzymes Ubc5 and Cdc34. In the context of the VHL ubiquitin ligase, Elongin BC functions as an adaptor that links the VHL protein to the Cul2/Rbx1 module, raising the possibility that the Elongin BC complex could function as an integral component of a larger family of E3 ubiquitin ligases by linking alternative BC-box proteins to Cullin/Rbx1 modules. In this report, we describe identification and purification from rat liver of a novel leucine-rich repeat-containing BC-box protein, MUF1, which we demonstrate is capable of assembling with a Cullin/Rbx1 module containing the Cullin family member Cul5 to reconstitute ubiquitin ligase activity. In addition, we show that the additional BC-box proteins Elongin A, SOCS1, and WSB1 are also capable of assembling with the Cul5/Rbx1 module to reconstitute potential ubiquitin ligases. Taken together, our findings identify MUF1 as a new member of the BC-box family of proteins, and they predict the existence of a larger family of Elongin BC-based E3 ubiquitin ligases.

Amino Acid Sequence↗
PubMed2001

Cloning and characterization of ELL-associated proteins EAP45 and EAP20. a role for yeast EAP-like proteins in regulation of gene expression by glucose.

RNA polymerase II elongation factor ELL was recently purified from rat liver as a component of a multiprotein complex containing ELL and three ELL-associated proteins (EAPs) of approximately 45 (EAP45), approximately 30 (EAP30), and approximately 20 (EAP20) kDa (Shilatifard, A. (1998) J. Biol. Chem. 273, 11212-11217). Cloning of cDNA encoding the EAP30 protein revealed that it shares significant sequence similarity with the product of the Saccharomyces cerevisiae SNF8 gene (Schmidt, A. E., Miller, T., Schmidt, S. L., Shiekhattar, R., and Shilatifard, A. (1999) J. Biol. Chem. 274, 21981-21985), which is required for efficient derepression of glucose-repressed genes. Here we report the cloning of cDNAs encoding the EAP45 and EAP20 proteins. In addition, we identify the S. cerevisiae VPS36 and YJR102c genes as potential orthologs of EAP45 and EAP20 and show that they are previously uncharacterized SNF genes with properties very similar to SNF8.

Amino Acid Sequence↗
PubMed2001

Prognostic factors of stage IV epithelial ovarian cancer: a multicenter retrospective study.

OBJECTIVE: In the present study, we conducted a multicenter retrospective analysis to elucidate the prognostic factors of stage IV epithelial ovarian cancer. METHODS: In November 1999, 24 Japanese institutions received questionnaires regarding stage IV epithelial ovarian cancer patients. Eligibility criteria included all patients with stage IV epithelial ovarian cancer who were surgically confirmed and initially treated in each institution between January 1990 and December 1997. Data were collected regarding age, performance status, tumor histologic subtype, site of metastasis, preoperative CA125, cytoreductive surgery, residual disease after cytoreductive surgery, and response to primary chemotherapy. Survival analysis and comparisons were performed by univariate and multivariate methods. RESULTS: Two hundred twenty-five patients with stage IV ovarian cancer were identified. The median age of the patients was 54 years. The most common site of extraperitoneal disease was malignant pleural effusion (39.6%). Of the 225 patients who underwent an attempt at surgical debulking, 70 (31.1%) were optimally cytoreduced. Most patients received platinum-based combination chemotherapy for primary chemotherapy. In multivariate analysis, performance status, histology, and residual disease after cytoreductive surgery were independent prognostic predictors of outcome. The overall median survival for optimally debulked patients was 32 months compared to 16 months for suboptimally debulked patients (P < 0.0001, hazard ratio: 0.415). CONCLUSION: Optimal surgical debulking, performance status, and histology appear to be important prognostic factors of survival in patients with stage IV epithelial ovarian cancer.

Adult↗
PubMed2001

Relationship between age, histological type, and size of ovarian tumors.

OBJECTIVE: To clarify the relationship between age, histological type, and size of ovarian tumors. METHOD: A review was made of 1648 cases of histopathologically diagnosed ovarian tumors and tumor-like lesions, and information on the age of the patients and size of the tumor was obtained. Statistical analysis was performed using Kruskal-Wallis tests or Mann-Whitney U-tests. RESULTS: There were 840 (51%) cases of benign tumors, 73 (4%) cases of tumors of low malignant potential (LMP), 268 (16%) cases of malignant tumors and 467 (28%) cases of tumor-like lesions. The age of the patients was significantly different among tumor-like lesions (34.6+/-8.1 years), benign tumors (39.8+/-16.4 years), LMP tumors (45.2+/-18.3 years) and malignant tumors (51.9+/-13.0 years) (P<0.0001). The maximum diameter of the tumors was significantly different among tumor-like lesions (7.1+/-3.3 cm), benign tumors (10.9+/-5.6 cm), malignant tumors (13.6+/-6.5 cm) and LMP tumors (18.5+/-6.8 cm) (P<0.0001). CONCLUSION: The distribution of tumor histological type (tumor-like lesions, benign, LMP and malignant) was correlated against patient age and lesion diameter, with tumors in older patients or larger tumors more likely to be malignant.

Adult↗
PubMed2001

Weekly 1 hour paclitaxel infusion in patients with recurrent gynecological tumors: a pilot study.

BACKGROUND: Intensifying the dose of paclitaxel given in a weekly schedule is useful towards improving the therapeutic index of paclitaxel in treating a variety of advanced and recurrent malignancies and is suitable for outpatient administration. This pilot study was carried out to evaluate the safety of weekly paclitaxel administration by 1 h infusion in the outpatient setting. METHODS: Eleven patients with recurrent gynecological tumors who had previously been treated with at least one platinum-based chemotherapy regimen participated in the study between May 1999 and March 2000. Paclitaxel was given at a dose of 70 mg/m(2 ) as a 1 h infusion every week for at least 20 consecutive weeks unless lesions became progressive. Intravenous dexamethasone and cimetidine and oral diphenhydramine were administered 30 min before paclitaxel infusion. RESULTS: The 11 patients received a total of 166 cycles of therapy. All patients received 70 mg/m(2 ) doses of paclitaxel without treatment delay. No hypersensitivity reactions were elicited. Grade 3 or 4 leukopenia and neutropenia occurred in 9 and 36% of the patients, respectively. Granulocyte colony-stimulating factor was required for only one patient and no patients experienced febrile neutropenia. Neurotoxicity was the most serious adverse effect and all patients experienced grade 1 or 2 peripheral neuropathy. Grade 1 or 2 myalgias were observed in 45% of the patients. Alopecia was universal. No Grade 3 or higher non-hematological toxicities were observed. CONCLUSION: Weekly 1 h paclitaxel administration is considered safe as a salvage therapy for recurrent gynecological tumors, making its use more convenient and easier in the outpatient setting. The current results support further evaluation.

Ambulatory Care↗
PubMed2001

[A modified administrated schedule for combination therapy with irinotecan and cisplatin as a neoadjuvant chemotherapy in locally advanced cervical cancer--a report of 2 cases as a pilot study].

To shorten the treatment term of neoadjuvant chemotherapy (NAC) for locally advanced cervical cancer, a combination of irinotecan (CPT-11) and cisplatin was administered on a modified administrated schedule for 2 eligible patients as a pilot study. CPT-11 70 mg/m2 was administered (div) on days 1 and 8, followed by cisplatin 70 mg/m2 given (div) on day 1. Treatment was repeated every 3 weeks for a total of two cycles. Both patients showed a complete clinical response. No severer toxicities were observed than with the usual regimen, and both cases could undergo radical hysterectomy after NAC. The results suggest that this modified regimen of combination of CPT-11 and cisplatin can be effective as an NAC in cases of locally advanced cervical cancer, especially in terms of shortening treatment term. This regimen is worthy of further study.

Adult↗
PubMed2000

Successful treatment of two patients with recurrent endometrial cancer by weekly paclitaxel.

OBJECTIVE: The aim of this study was to evaluate the toxicity and efficacy of weekly paclitaxel in patients with recurrent endometrial cancer. METHODS: Paclitaxel (70 mg/m(2) by 1-h infusion weekly) was administered to two patients with recurrent endometrial cancer of the lung. RESULTS: After 5 cycles, both patients with platinum-resistant disease achieved clinical partial responses confirmed by computed tomography (CT) scan. The serum CA125 levels of case 1 decreased to cut-off level. The response duration of both patients was 4 months. The toxicity was acceptable and probably less pronounced than that characterize of the standard tri-weekly schedules. CONCLUSION: Although conclusions regarding survival are premature, weekly paclitaxel might offer better quality of life during treatment.

Adenocarcinoma↗
PubMed2000

Activation of HIF1alpha ubiquitination by a reconstituted von Hippel-Lindau (VHL) tumor suppressor complex.

Mutations in the VHL tumor suppressor gene result in constitutive expression of many hypoxia-inducible genes, at least in part because of increases in the cellular level of hypoxia-inducible transcription factor HIF1alpha, which in normal cells is rapidly ubiquitinated and degraded by the proteasome under normoxic conditions. The recent observation that the VHL protein is a subunit of an Skp1-Cul1/Cdc53-F-box (SCF)-like E3 ubiquitin ligase raised the possibility that VHL may be directly responsible for regulating cellular levels of HIF1alpha by targeting it for ubiquitination and proteolysis. In this report, we test this hypothesis directly. We report development of methods for production of the purified recombinant VHL complex and present direct biochemical evidence that it can function with an E1 ubiquitin-activating enzyme and E2 ubiquitin-conjugating enzyme to activate HIF1alpha ubiquitination in vitro. Our findings provide new insight into the function of the VHL tumor suppressor protein, and they provide a foundation for future investigations of the mechanisms underlying VHL regulation of oxygen-dependent gene expression.

Animals↗