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Biomedical subjects

S Tsunoda

Publications and source records attributed to S Tsunoda.

At least 19 recordsLinked to original sources
PubMed2006

Significance of nerve growth factor overexpression and its autocrine loop in oesophageal squamous cell carcinoma.

Nerve growth factor (NGF) is overexpressed not only in nervous system, but also in several types of cancers. However, the role of NGF in oesophageal squamous cell carcinoma (OESCC) remains unclear. Here, we show the first evidence of NGF-TrkA autocrine loop and clinical significance of NGF overexpression in OESCC. Immunohistochemical study of 109 OESCC specimens revealed that NGF overexpression, found in 63 out of 109 patients (57.8%), was associated with lymph node metastasis, distant metastasis, higher TNM stage, poorer tumour differentiation, and poorer survival. NGF overexpression was also associated with strong expression of TrkA and negative expression of low-affinity neurotrophin receptor (p75NTR). Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) of 19 surgical specimens showed upregulation of NGF mRNA in 17 out of 19 (89%) patients. All five OESCC cell lines tested in vitro secreted detectable NGF in enzyme-linked immunosorbent assay, and expressed TrkA and p75NTR on RT-PCR and Western blot. The motility of HSA/c, one of the OESCC cell lines overexpressing NGF, was significantly decreased by either neutralising anti-NGF antibody, an inhibitor of TrkA, or NGF-small interfering RNA in transwell migration assay. Our findings suggest that NGF is of potential interest not only as a prognostic factor, but also as a novel therapeutic target in OESCC.

Adult↗
PubMed2006

Transthoracic direct current shock facilitates intramyocardial transfection of naked plasmid DNA infused via coronary vessels in canines.

Catheter-mediated, percutaneous, transluminal delivery of naked plasmid DNA (pDNA) into myocardium may offer a valuable strategy to heart diseases. Here, we examined whether clinically available transthoracic direct current (DC) shock improves intracoronary naked DNA transfection into myocardium. Plasmid vector encoding the GL3 luciferase was infused retrogradely into the coronary veins of beagle dogs, whereas another pDNA solution was infused into the left coronary artery. During and after these procedures, the coronary venous sinus was occluded by balloon, and transthoracic DC shock of 200 J was applied immediately after the infusions. Without DC shock, no remarkable increase in luciferase activity was demonstrated in any part of the left ventricular myocardium. In the presence of DC pulsation, significant luciferase expression was detected in the regions that were supplied by left anterior descending coronary artery (LAD), whereas the gene expression in the right coronary artery (RCA) regions was much less drastic. X-gal (5-bromo-4-chloro-3-indolyl-beta-D-galactoside) staining of cardiac cross-sections also revealed regional expression of beta-galactosidase. Immunohistochemical examinations of heart cryosections revealed that cardiomyocytes in LAD regions successfully expressed transgene product. The present system may enable a new strategy for myocardial gene therapy, without any special device or technique other than cardiac catheterization and DC cardioversion that are generally performed in ordinary hospitals.

Animals↗
PubMed2006

Optimal dose for stage IIIB adenocarcinoma of the uterine cervix on the basis of biological effective dose.

PURPOSE: Prognosis of uterine cervical adenocarcinoma in locally advanced stage treated with radiation therapy has been considered to be much worse than that of squamous cell carcinoma because the optimal dose for the former one has not been determined. Thus, the current study was performed to investigate the optimal dose for Stage IIIB, locally advanced stage, adenocarcinoma of the uterine cervix on the basis of the biological effective dose (BED). METHODS: One-hundred and seventy-nine patients with Stage IIIB carcinoma of the uterine cervix were treated with curative intended therapy at Kitasato University Hospital between 1976 and 2000. Out of them, 13 patients had an adenocarcinoma component in pathological findings. Nine patients were diagnosed with adenocarcinoma and four patients were diagnosed with adenosquamous cell carcinoma. All patients were treated with external radiation therapy combined with intracavitary radiation therapy. The total BED10 (T-BED10) was caluculated from the BED of the external beam radiation therapy (E-BED10) plus the BED of the intra-cavitary radiation therapy (A-BED). RESULTS: Overall survival rate was 51%. Stratified by T-BED10 overall survival rate of the T-BED10 > or = 100 Gy group was 57% and that of the T-BED10 < 100 Gy group was 30%. There was a trend toward a better survival rate of the T-BED10 > or = 100 Gy group than the T-BED10 < 100 Gy group. CONCLUSION: The current study suggested that the optimal dose for Stage IIIB adenocarcinoma of the uterine cervix might be T-BED10 > or = 100 Gy.

Adenocarcinoma↗
PubMed2006

C-kit overexpression in neuroendocrine small cell carcinoma of the uterine cervix.

PURPOSE OF INVESTIGATION: Neuroendocrine small cell carcinoma of the uterine cervix (NESCC) grows aggressively, and is resistant to anticancer agents and radiation, having an extremely poor prognosis. The incidence of c-kit proto-oncogene overexpression is high in gastrointestinal stromal tumors (GISTs) and small cell lung cancer, and tyrosine kinase inhibitors have been used effectively to treat GISTs. Few studies have investigated whether c-kit is overexpressed in NESCC. To investigate whether NESCC can be a target for molecular targeted therapy with tyrosine kinase inhibitors, we examined the expression of c-kit in this tumor. METHODS: Twenty-one NESCCs were examined for c-kit expression by immunohistochemical staining using the labeled streptavidin-biotin complex (LSAB) method. The expression of c-kit was regarded as positive (overexpression) and negative when the membrane and cytoplasm of more or less than 25%, respectively, of tumor cells were stained. RESULTS: Nine NESCCs (43%) were c-kit-positive (overexpression). No difference in age or clinical stage was noted. No difference in prognosis was observed between the c-kit-positive and -negative patients. CONCLUSION: The incidence of c-kit overexpression was high in NESCC; therefore, the patients with this tumor may become a future target for molecular-targeted therapy with tyrosine kinase inhibitors.

Adult↗
PubMed2006

Optimization of anti-tumor necrosis factor-alpha single chain Fv displayed on phages for creation of functional antibodies.

In this study, we converted the immunoglobulin-type anti-human tumor necrosis factor-alpha (TNF-alpha) monoclonal antibody (Mab) to a scFv-type antibody in order to assess its basic properties. The immunoglobulin VH and VL genes were isolated from the hybridoma that produced an anti-TNF-alpha neutralizing Mab, and they were then linked together to create scFvs of the VL-VH or VH-VL-form. The binding affinity to TNF-a was retained in both scFvs. Interestingly, the VL-VH-type scFv effectively inhibited the TNF-alpha-mediated cytotoxicity, while this neutralization activity was dramatically decreased in the VH-VL-type scFv. These results suggest that the VL-VH-type scFv is a suitable template to create improved versions of the anti-TNF-alpha antibody using a phage display system, and they also show that the structural format must be taken into account in manufacturing scFvs.

Antibodies, Blocking↗
PubMed2003

Age and duration related changes in muscle sympathetic nerve activity in Parkinson's disease.

OBJECTIVE: To clarify the characteristics of sympathetic vasomotor function in Parkinson's disease by sympathetic neurographic analysis. METHODS: Muscle sympathetic nerve activity (MSNA) was recorded using a microneurographic technique at rest and during head up tilt in 18 patients with idiopathic Parkinson's disease and 21 healthy controls. RESULTS: Heart rate and blood pressure at rest did not differ between index and control subjects. The increase in these variables and MSNA in response to tilting was slightly blunted in the Parkinson's group. Resting MSNA showed a negative correlation with age in patients with Parkinson's disease (p<0.05) and a positive correlation with age in controls (p<0.01). There was a negative correlation between duration of disease or disability levels and MSNA (p<0.01). CONCLUSIONS: Sympathetic vasomotor function may be related to age and disease duration in Parkinson's disease.

Age Factors↗
PubMed2002

Schedule-dependent synergism and antagonism between methotrexate and cytarabine against human leukemia cell lines in vitro.

Methotrexate (MTX) and cytarabine have been widely used for the treatment of acute leukemias and lymphomas for over 30 years. However, the optimal schedule of this combination is yet to be determined and a variety of schedules of the combination has been used. We studied the cytotoxic effects of MTX and cytarabine in combination against human leukemia cell lines at various schedules in vitro. The effects of the combinations at the concentration of drug that produced 80% cell growth inhibition (IC(80)) were analyzed using the isobologram method of Steel and Peckham. Simultaneous exposure to MTX and cytarabine for 3 days produced antagonistic effects in human T cell leukemia, MOLT-3 and CCRF-CEM, B cell leukemia, BALL-1, Burkitt's lymphoma, Daudi, promyelocytic leukemia, HL-60 and Philadelphia chromosome-positive leukemia, K-562 cells. Simultaneous exposure to MTX and cytarabine for 24 h produced antagonistic effects, sequential exposure to MTX for 24 h followed by cytarabine for 24 h produced synergistic effects, and the reverse sequence produced additive effects in both CCRF-CEM and HL-60 cells. Sequential exposure to MTX for 24 h followed by cytarabine for 3 days also produced synergistic effects in MOLT-3 cells. Cell cycle analysis supported these observations. Our findings suggest that the simultaneous administration of MTX and cytarabine is not appropriate and the sequential administration of MTX followed by cytarabine may be the optimal schedule of this combination.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Proliferating cell nuclear antigen positive cells in the hippocampal subgranular zone decline after irradiation in a rodent model.

Four-week-old ICR mice were systemically exposed to 18Gy X-rays. Afterwards, the expression of proliferating cell nuclear antigen (PCNA) in the cerebrum was observed with time using Western blot analysis and immunohistochemical staining. As a result, PCNA-positive cells were observed in the subgranular zone (SGZ) of the hippocampus and subventricular zone (SVZ) of the lateral ventricles in unirradiated mice. The number of PCNA-positive cells decreased with time in all zones after irradiation, but the decrease was more marked in the hippocampal SGZ. We think that PCNA-positive cells are stem cells. The selective vulnerability to radiation in the hippocampus is considered to be attributed to the fact that stem cells in the SGZ selectively undergo radiation-induced apoptosis.

Animals↗
PubMed2001

In vitro cytotoxic effects of a tyrosine kinase inhibitor STI571 in combination with commonly used antileukemic agents.

The BCR/ABL tyrosine kinase has been implicated in the pathogenesis of chronic myelogenous leukemia (CML) and Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL). STI571 is a novel anticancer agent that selectively inhibits the BCR/ABL tyrosine kinase. The cytotoxic effects of STI571 were studied in combination with antileukemic agents against Ph(+) leukemia cell lines, KU812, K-562, TCC-S, and TCC-Y. The cells were exposed to STI571 and to other agents simultaneously for 5 or 7 days. Cell growth inhibition was determined by MTT assay. The cytotoxic effects in combinations at the inhibitory concentration of 80% level were evaluated by the isobologram. STI571 produced synergistic effects with recombinant and natural alpha-interferons in 2 of 3 and 3 of 3 cell lines, respectively. STI571 produced additive effects with hydroxyurea, cytarabine, homoharringtonine, doxorubicin, and etoposide in all 4 cell lines. STI571 with 4-hydroperoxy-cyclophosphamide, methotrexate, or vincristine produced additive, antagonistic, and synergistic effects in 3 of 4 cell lines, respectively. These findings suggest that the simultaneous administration of STI571 with other agents except methotrexate would be advantageous for cytotoxic effects against Ph(+) leukemias. Among them, the simultaneous administration of STI571 and alpha-interferons or vincristine would be highly effective against Ph(+) leukemias and these combinations would be worthy of clinical trials. In contrast, the simultaneous administration of STI571 with methotrexate would have little therapeutic efficacy. Although there are gaps between in vitro studies and clinical trials, the present findings provide useful information for the establishment of clinical protocols involving STI571. (Blood. 2001;97:1999-2007)

Antineoplastic Agents↗
PubMed2001

Independent anchoring and assembly mechanisms of INAD signaling complexes in Drosophila photoreceptors.

In Drosophila photoreceptors the multivalent PDZ protein INAD organizes the phototransduction cascade into a macromolecular signaling complex containing the effector PLC, the light-activated TRP channels, and a regulatory PKC. Previously, we showed that the subcellular localization of INAD signaling complexes is critical for signaling. Now we have examined how INAD complexes are anchored and assembled in photoreceptor cells. We find that trp mutants, or transgenic flies expressing inaD alleles that disrupt the interaction between INAD and TRP, cause the mislocalization of the entire transduction complex. The INAD-TRP interaction is not required for targeting but rather for anchoring of complexes, because INAD and TRP can be targeted independently of each other. We also show that, in addition to its scaffold role, INAD functions to preassemble transduction complexes. Preassembly of signaling complexes helps to ensure that transduction complexes with the appropriate composition end up in the proper location. This may be a general mechanism used by cells to target different signaling machinery to the pertinent subcellular location.

Animals↗
PubMed2001

Electron microscopic and cytochemical studies of peroxidase-negative acute nonlymphoblastic leukemia.

Cytochemical and ultrastructural studies of 42 patients with acute nonlymphoblastic leukemia (ANLL) lacking myeloperoxidase as detected by light microscopy were performed. These ANLL patients were classified into minimally differentiated acute myeloid leukemia (AML-M0) (26 cases), mixed-lineage leukemia (9 cases), and acute undifferentiated leukemia (AUL) (7 cases). Ultrastructural morphology revealed blasts from AML-M0 as very immature myeloid cells, blasts from mixed-lineage leukemia as having partially lymphoid cell features, and blasts from AUL as undifferentiated blasts with myeloid nature to some extent. Ultrastructurally, myeloperoxidase activity was positive in 81% of AML-M0 patients and less positive in the mixed-lineage leukemia and AUL patients. The DNA in the nuclei of the AML-M0 blasts was dispersed, as was observed in the immature myeloid cells. Some of the blasts from the mixed-lineage leukemia patients showed condensation of DNA, resembling blasts from acute lymphoblastic leukemia (ALL). The distribution of periodate-reactive glycoconjugates revealed that glycogen particles were absent or, if present, very scanty in AML-M0. Most of the blasts from the AUL patients lacked glycogen particles, and the blasts from those with mixed-lineage leukemia contained clustered glycogen particles, as was observed in the blasts from all patients. These findings disclosed that three subtypes of immature ANLL showed different cytochemical and ultrastructural features in accordance with their immunophenotypical classification.

Adolescent↗
PubMed2001

Selective enhancement of thrombopoietic activity of PEGylated interleukin 6 by a simple procedure using a reversible amino-protective reagent.

We developed a novel method for the chemical modification of cytokines with synthetic polymers to increase the therapeutic efficacy of the former in vivo. A pH-reversible amino-protective reagent, dimethylmaleic anhydride (DMMAn), was used for modification of interleukin-6 (IL-6) with polyethylene glycol (PEG). The novel PEG-conjugated IL-6 (DmPEG-IL-6), which had been pretreated with DMMAn before PEGylation, showed up to a 140% increase in in vitro specific activity compared with PEG-IL-6 that had been synthesized by the previous method. Moreover, DmPEG-IL-6 caused thrombopoiesis more potently in mice than PEG-IL-6. The DmPEG-IL-6 Fr.1, having 3-4 PEG chains attached to the cytokine, showed the strongest thrombopoietic effect among the DmPEG-IL-6s with different molecular sizes that were tested. PEG-IL-6 Fr.1 had a 500-fold higher potency in stimulating thrombopoiesis than native IL-6 and DmPEG-IL-6 Fr.1 achieved a threefold higher thrombopoietic effect than PEG-IL-6 Fr.1. In addition, side-effects, such as an increase in the plasma fibrinogen level, were not observed after injection of either PEG-IL-6s or DmPEG-IL-6s. These results suggest that PEGylation with DMMAn pretreatment may become a useful means for clinical cytokine delivery.

Animals↗
PubMed2001

Covered metallic stent treatment of a patient with spontaneous rupture of the esophagus.

A patient with a potentially fatal condition as a result of esophago-pneumo-broncho fistula was successfully treated with the insertion of a self-expanded covered metallic stent. Severe regurgitation resulted in the removal of the stent 3 months after insertion. Stricture after removal of the stent required pneumatic balloon dilation. The use of a self-expanded covered metallic stent is effective for the treatment of spontaneous esophageal rupture; however, early removal of the stent is recommended.

Bronchial Fistula↗
PubMed2001

Cultured rat glomerular epithelial cells show gene expression and production of transforming growth factor-beta: expression is enhanced by thrombin.

BACKGROUND: Glomerular crescents play an important role in progressive glomerular injury. The lesions consist of epithelial cells, macrophages, and deposits of fibrin and extracellular matrix. Transforming growth factor beta (TGF-beta) contributes to the modulation of cell growth and extracellular matrix synthesis. Thrombin is involved in fibrin formation in crescents. The purpose of this study was to examine whether glomerular epithelial cells (GEC) could produce TGF-beta, and if so, to clarify the role of TGF-beta in GEC proliferation. We also investigated whether thrombin could modulate the production of TGF-beta and extracellular matrix by GEC. METHODS: Bioassay using the TGF-beta-dependent mink pulmonary epithelial cell line (CCL-64), immunoblot analysis, and reverse transcriptase polymerase chain reaction (RT-PCR) were used to demonstrate TGF-beta production by rat GEC. TGF-beta gene expression was examined by RT-PCR in GEC incubated with thrombin, and type IV collagen and fibronectin were quantified by enzyme immunoassay in culture supernatants of GEC incubated with thrombin or TGF-beta. RESULTS: TGF-beta activity was demonstrated in GEC supernatants by bioassay. Immunoblot analysis of concentrated culture supernatants using anti-TGF-beta antibody revealed a 12.5-kDa protein, which was compatible with TGF-beta. Concentrated GEC supernatants inhibited GEC proliferation as well as porcine TGF-beta. RT-PCR demonstrated TGF-beta gene expression in GEC. Thrombin (0.5-5.0 U/ml) enhanced TGF-beta mRNA expression in a dose-dependent manner. Thrombin (5.0 U/ml) and porcine TGF-beta (5.0 ng/ml) stimulated the production of type IV collagen and fibronectin by GEC. CONCLUSIONS: Rat GEC produce TGF-beta in vitro. Thrombin may participate in the progression of glomerulosclerosis in crescentic glomerulonephritis through the stimulation of TGF-beta production by GEC.

Animals↗
PubMed2001

Schedule-dependent synergism and antagonism between raltitrexed ("Tomudex") and methotrexate in human colon cancer cell lines in vitro.

The folate-dependent enzymes are attractive targets for cancer chemotherapy. Methotrexate (MTX), which inhibits dihydrofolate reductase, has been widely used for the treatment of solid tumors and hematological cancers. Raltitrexed ("Tomudex") ), which inhibits thymidylate synthase, is a novel anticancer agent active against colorectal cancer and some other solid tumors. We studied the optimal schedule of raltitrexed and MTX in combination against four human colon cancer cell lines Colo201, Colo320, LoVo, and WiDr. These cells were simultaneously exposed to raltitrexed and MTX for 24 h, or sequentially exposed to raltitrexed for 24 h followed by MTX for 24 h, or vice versa. Cell growth inhibition after 5 days was determined by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of drug combinations at the concentrations of drug that produced 80% and 50% cell growth inhibition (IC(80) and IC(50)) were analyzed by the isobologram method (Steel and Peckham, 1979). Cytotoxic interactions between raltitrexed and MTX were schedule-dependent. The simultaneous exposure to raltitrexed and MTX showed additive effects in Colo201, LoVo and WiDr cells and antagonistic effects in Colo320 cells. The sequential exposure to raltitrexed followed by MTX produced additive effects in all four cell lines. The sequential exposure to MTX followed by raltitrexed produced synergistic effects in Colo201, LoVo and WiDr cells and additive effects in Colo320 cells. These findings suggest that the sequential administration of MTX followed by raltitrexed produces more than the expected cytotoxicity and may be the optimal schedule at the cellular level. Further in vivo and clinical studies will be necessary to determine the toxicity and to test the antitumor effects of sequential administration of MTX followed by raltitrexed proposed on the basis of the in vitro synergism.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Pregnancy outcome in nephrotic syndrome with mixed connective tissue disease.

We describe two pregnancies of a young woman with mixed connective tissue disease. In June 1983, she was diagnosed as having Raynaud's phenomenon, arthralgia, and proteinuria. She then developed nephrotic syndrome. Methylprednisolone was initially prescribed at a large dose of 1 g/day which was slowly tapered to 5 mg/day. The proteinuria disappeared. During both pregnancies (the first beginning in December 1988 and the second in May 1992), the patient was placed on a prednisolone maintenance dose (5 mg/day). Both neonates were born healthy at term with no complications. Continuing prednisolone may be useful in pregnant women, and aggressive treatment to prevent mixed connective tissue disease exacerbation may be appropriate during pregnancy.

Adult↗
PubMed2001

TMC-69, a new antitumor antibiotic with Cdc25A inhibitory activity, produced by Chrysosporium sp. TC1068. Taxonomy, fermentation and biological activities.

A new antibiotic designated TMC-69 has been isolated from the fermentation broth of a fungal strain Chrysosporium sp. TC 1068. TMC-69 exhibited moderate in vitro cytotoxic activity. TMC-69-6H, a derivative of TMC-69 prepared by hydrogenation, possessed more potent in vitro cytotoxicity than TMC-69, and exhibited in vivo antitumor activity against murine P388 leukemia and B16 melanoma. TMC-69-6H was found to specifically inhibit Cdc25A and B phosphatases.

Animals↗