Search PubMed⌕ Search

Biomedical subjects

S Komiyama

Publications and source records attributed to S Komiyama.

At least 91 records · Page 5Linked to original sources
PubMed1994

Giant tumor formed by nodular fasciitis of the pharynx: a case report.

Nodular fasciitis caused a benign tumor which is composed of fibrous tissue. The most commonly affected site is the upper extremity, which accounts for half of all cases. Ten to 20% of the lesions occur in the head and neck area, most of which are subcutaneous. We report a case of nodular fasciitis, which presented as an unusually large submucosal tumor of the pharynx. The tumor was extended from the retropharyngeal to the parapharyngeal space, and it was measured 8 x 4 x 3 cm in size. Since nodular fasciitis is known for the spontaneous regression, the tumor was transorally debulked by the use of YAG laser.

Adult↗
PubMed1994

Coexistence of MALT-type lymphoma and squamous cell carcinoma of the larynx.

A 66-year-old Japanese man was diagnosed as having a MALT-type lymphoma by histopathological examination. The lesion involved the vocal folds bilaterally, occupying the larynx and extending beyond it, as shown by computed tomography (CT). A course of radiation therapy with moderate doses was given. Six months later, a squamous cell carcinoma was found in the larynx and total laryngectomy was then performed. The patient remained well, without recurrence, 46 months after the operation. thus, MALT-type lymphoma may coexist with a squamous cell carcinoma of the larynx.

Aged↗
PubMed1994

Single channel recordings of calcium currents in chick cochlear hair cells.

Single Ca2+ channel currents were recorded from chick cochlear hair cells by using cell-attached patches. The elementary current was about -2 pA at 70 mV positive to the resting potential (R.P.+ 70 mV); the slope conductance over a 40 mV voltage range was 24 pS. The open time histogram was reasonably well expressed by a single exponential function, while the closed time histogram was expressed by a sum of two exponential functions. The Ca2+ channel was activated around R.P.+ 60 mV and the average ensemble current did not decay during 130 ms depolarization, suggesting that the Ca2+ channel in chick cochlear hair cells is the L-type. The Ca2+ channel has three modes of gating behaviour, expressed as current records with brief openings (mode I), no openings (mode 0), or long-lasting openings and very brief closings (mode 2).

Animals↗
PubMed1994

[A prospective randomized trial of adjuvant chemotherapy with UFT for head and neck carcinoma. Head and Neck UFT Study Group].

A prospective randomized trial was performed in 67 institutions for the purpose to evaluate the efficacy of adjuvant chemotherapy after radical treatment of head and neck carcinoma. A comparison was made between the following two groups; one-year oral administration of UFT, 300 mg/day, after radical treatment (UFT group); and a non-treatment group. Patients were classified under the following three categories; 1) stage II-IV, receiving radical surgery; 2) stage II, receiving radical radiotherapy; and 3) nasopharyngeal cancer. The numbers of cases were 424, 111 and 25, respectively, and they were randomized into two groups. The numbers of eligible cases were 398, 105 and 25, respectively. Statistical analysis was performed in the cases receiving radical surgery and in those receiving radical radiotherapy. As the results, in cases receiving radical surgery no significant difference was observed in 3-year survival rates (77.9% for UFT group vs 72.9% for non-treatment group) or 3-year relapse-free rates (73.4% for UFT group vs 66.2% for non-treatment group) between the two groups. However, the distant relapse rate was significantly lower in the UFT group than in the non-treatment group (7.9% vs 14.6%; p = 0.034). In the cases receiving radical radiotherapy, no significant differences was observed in either 3-year survival rates or 3-year relapse-free rates. Thus it was suggested that UFT maintenance therapy might suppress the distant metastasis after radical surgery. We considered a further confirmative trial for patients at high risk of distant metastasis after radical surgery to be advisable.

Administration, Oral↗
PubMed1993

A trial of individual dose intensity and relative performance factors in tegafur maintenance chemotherapy for head and neck cancer.

Tegafur (Sunfural-S), as masked compound of a 5-fluorouracil derivative, was administered orally as a maintenance chemotherapeutic agent at a dose of 600 mg/day in 98 cases of head and neck epithelial cancer. The effectiveness of the drug was evaluated by a statistical method involving two formulae: individual dose intensity (IDI) and relative performance (RP). When comparing patients rated above a reference IDI value of 1.0 with those rated below 1.0, it was not possible to predict patient survival or tumor-free rates. In contrast, the value of the RP did show such a correlation. These findings support the effectiveness of Tegafur as a maintenance chemotherapeutic treatment for head and neck cancer patients.

Aged↗
PubMed1993

Cisplatin blocks mechano-electric transducer current in chick cochlear hair cells.

The effects of cisplatin (cis-dichlorodiammine platinum II, CDDP) on the mechano-electrical transduction (MET) current were investigated with a whole-cell patch-electrode voltage clamp technique in dissociated cochlear hair cells of chicks. CDDP blocked the MET channel in a dose- and voltage-dependent manner. At -50 mV, CDDP blocked the MET channel with a Hill coefficient of approximately 2 and a dissociation constant (KD) of 1.5 x 10(-3) M. The kinetics of CDDP blockade consist of a voltage-independent and a voltage-dependent component.

Animals↗
PubMed1993

Molecular cloning of a human cDNA encoding a novel protein, DAD1, whose defect causes apoptotic cell death in hamster BHK21 cells.

The tsBN7 cell line, one of the mutant lines temperature sensitive for growth which have been isolated from the BHK21 cell line, was found to die by apoptosis following a shift to the nonpermissive temperature. The induced apoptosis was inhibited by a protein synthesis inhibitor, cycloheximide, but not by the bcl-2-encoded protein. By DNA-mediated gene transfer, we cloned a cDNA that complements the tsBN7 mutation. It encodes a novel hydrophobic protein, designated DAD1, which is well conserved (100% identical amino acids between humans and hamsters). By comparing the base sequences of the parental BHK21 and tsBN7 DAD1 cDNAs, we found that the DAD1-encoding gene is mutated in tsBN7 cells. The DAD1 protein disappeared in tsBN7 cells following a shift to the nonpermissive temperature, suggesting that loss of the DAD1 protein triggers apoptosis.

Amino Acid Sequence↗
PubMed1993

Analysis of vocal abuse: fluctuations in phonation time and intensity in 4 groups of speakers.

We have seen many patients with a voice disorder due to vocal abuse. However, there is little information about the speaking behaviour of such patients. The object of this study was to analyze speaking behaviour and to evaluate the relationship between the cause of voice disorders and its effects on speech. We had previously measured phonation time with a speech time accumulator. Recently, we have developed a speech intensity/speech time accumulator. We obtained data by accumulating the phonation time at 4 degrees of vocal intensity, ranging from weak to strong. By using this instrument, we measured the speaking habits of 29 subjects for 131 days and collected data about the criteria for vocal abuse. Our results showed that the office workers exhibited a phonation time (33.6 +/- 13.6 min for 8 h) three times shorter than that of teachers and patients with vocal fold nodules (102.1 +/- 22.9 min for 8 h). For the teachers and patients with a long phonation time, half of the total phonation time was at high intensity.

Acoustics↗
PubMed1993

Differentially potentiating effects by dipyridamole on cytotoxicity of 5-fluorouracil against three human maxillary cancer cell lines derived from a single tumor.

Dipyridamole (DPM), an inhibitor of nucleoside transport, is a unique potentiator of 5-fluorouracil (5-FU). We examined the combined effects of DPM and 5-FU on three cell lines (IMC-2, IMC-3, IMC-4) derived from a single tumor of a patient with maxillary cancer. DPM at 1.0-2.0 microM potentiated the cytocidal action of 5-FU > 20-fold against IMC-2 cells, while DPM at 10-20 microM potentiated the action of 5-FU against IMC-3 cells by 2-fold and against IMC-4 cells by approximately 4-fold. We examined why DPM differentially potentiated 5-FU against the three cell lines. The three maxillary cell lines showed heterogeneous sensitivities to the combination of 5-FU and DPM. We compared intracellular metabolism of 5-FU in IMC-2, IMC-3 and IMC-4 cells by HPLC. Determination of 5-FU metabolites demonstrated that cellular contents of 5-fluorodeoxyuridine monophosphate (FdUMP) were 104.66, 15.35 and 61.5 fmol/10(6) cells in IMC-2, IMC-3 and IMC-4 cells, respectively, in the presence of 10 microM DPM when the three cell lines had similar levels (0.21-0.33 fmol/10(6) cells) of FdUMP in the absence of DPM. By contrast, cellular levels of 5-FU and 5-fluorouridine triphosphate (FUTP) were not appreciably changed by DPM in three cell lines. The cellular level of thymidylate synthase mRNA in IMC-2 cells was found to be about one-fifth of that in IMC-3 and IMC-4 cells. The differential effects of DPM on the potentiation of 5-FU cytotoxicity might be closely related to the cellular levels of FdUMP and its target enzyme, thymidylate synthase in three human maxillary cancer cell lines.

Cell Survival↗
PubMed1992

Heterogeneity in epidermal growth factor responsiveness and tumor growth of human maxillary cancer cell lines.

We have established three cell lines (IMC-2, IMC-3, and IMC-4) from a human maxillary tumor, which exhibited different sensitivities to epidermal growth factor (EGF). It was inhibitory to colony-forming abilities of IMC-3 and IMC-4 cells in culture, while it affected that of IMC-2 cells slightly if at all. The differential sensitivities to EGF among the three cell lines were reproducibly observed when several cell sublines were further established from tumors appearing in nude mice. Saturation-binding kinetics with 125I-EGF showed similar levels of EGF-binding activities among the three cell lines. However, IMC-2, IMC-3, and IMC-4 showed almost similar sensitivities to cisplatin. Autophosphorylation of EGF receptor in the presence of EGF proceeded at similar levels among the three cell lines. Tumor growth was followed in nude mice when IMC-2, IMC-3, and IMC-4 at 1 x 10(7) cells were inoculated. The IMC-2 tumors enlarged at much faster rates than the other two cell lines. The IMC-4 tumors showed very slow growth rates, and IMC-3 tumors enlarged at an intermediate rate. These data suggest that the maxillary tumor used comprised cell populations that differed in their growth behaviors in response to EGF.

Carcinoma, Squamous Cell↗
PubMed1992

[An early phase II clinical study of cis-diammine glycolato platinum, 254-S, for head and neck cancers].

An early phase II clinical study of 254-S, a new anticancer platinum complex, for head and neck cancer was conducted by the 254-S Head and Neck Cancer Study Group consisting of 10 institutions. Based on the results obtained in the phase I study, 254-S was administered at 100 mg/m2 by 60 min intravenous drip infusion after being dissolved in 300 ml of 5% xylitol. In principle, the 254-S administration was repeated at least 2 times at 4 week intervals. Hydration was performed, if needed. All 24 cases registered were regarded as complete cases evaluable for tumor response. Complete response (CR) was observed in 4 patients (16.7%), partial response (PR) in 5 (20.8%), no change (NC) in 11 and progressive disease (PD) in 4, for a 37.5% response rate. Three CR and 3 PR (40.0%) were obtained in 15 patients with prior chemotherapy, including 1 CR and 2 PR (33.3%) in 9 patients previously treated with cisplatin. Side effects were observed in 19 patients (79.2%). Major toxic effects were hematotoxicity, including thrombocytopenia (58.3%), leukopenia (58.3%) and anemia (33.3%), and gastrointestinal toxicity, including nausea and vomiting (45.8%) and anorexia (37.5%). Abnormal parameter changes on renal function were found in 2 patients (8.3%). Based on these results, it was concluded that 254-S is potentially a useful anticancer agent for the treatment of head and neck cancer, and should be further investigated in a late phase II clinical study.

Adenocarcinoma↗
PubMed1992

[A late phase II clinical study of cis-diammine glycolato platinum, 254-S, for head and neck cancers].

A late phase II clinical study of 254-S, a new anticancer platinum complex, for head and neck cancer was conducted by the 254-S Head and Neck Cancer Study Group consisting of 31 institutions. As in the early phase II study for head and neck cancers, 254-S was administered at 100 mg/m2 by 60 min intravenous drip infusion, repeated at least twice at 4-week intervals. Of 80 cases registered, 66 were regarded as complete cases evaluable for tumor response. Complete response (CR) was observed in 7 patients (10.6%), partial response (PR) in 22 (33.3%), no change (NC) in 24 and progressive disease (PD) in 13, for a 43.9% response rate. Two CR and 11 PR (37.1% response rate) were obtained in 35 patients with prior chemotherapy, including 2 CR and 7 PR (33.3% response rate) in 27 patients previously treated with cisplatin. Of 70 patients evaluable for toxicity, side effects were observed in 60 patients (85.7%). Major toxic effects were hematotoxicity, including leukopenia (62.9%), thrombocytopenia (40.0%) and anemia (45.7%), gastrointestinal toxicity, including nausea and vomiting (64.3%), and anorexia (47.1%); grade 3 or 4 thrombocytopenia was found in 20.0% of the patients, and this toxicity was regarded as the dose limiting factor. Nephrotoxicity observed was mild and infrequent. Based on these results, it was concluded that 254-S is a very useful anticancer agent for the treatment of head and neck cancer.

Adenocarcinoma↗
PubMed1991

The response to epidermal growth factor of human maxillary tumor cells in terms of tumor growth, invasion and expression of proteinase inhibitors.

Three cancer cell lines, IMC-2, IMC-3 and IMC-4, were established from a single tumor of a patient with maxillary cancer. We examined responses to epidermal growth factor (EGF) of these 3 cell lines with regard to cell growth and tumor invasion. The growth rate of IMC-2 in nude mice was markedly faster than that of the IMC-3 and IMC-4 cell lines. Assay for invasion through fibrin gels showed significantly enhanced invasive capacity of IMC-2 cells in response to EGF, but no change for IMC-3 and IMC-4 cells. We examined response to EGF of IMC-2 cells with regard to expression of a growth-related oncogene (c-fos), proteinases and their inhibitors. Expression of c-fos was transiently increased in IMC-2 cells at rates comparable to those seen in the 2 other lines in the presence of EGF. There was no apparent effect of EGF on the expression of urokinase-type plasminogen activator and 72-kDa type-IV collagenase in IMC-2 cells. In contrast, EGF specifically enhanced the expression of plasminogen activator inhibitor-I (PAI-I) and tissue inhibitor of metalloproteinases-I (TIMP-I) in IMC-2 cells. Our data suggest that proteinase inhibitors or other related factors may play an important role in tumor growth and invasion in response to EGF.

Animals↗