Biomedical subjects

Atsushi Matsuo

Publications and source records attributed to Atsushi Matsuo.

9 recordsLinked to original sources

PubMed2006

The influence of size perception and internal modeling on the control process while lifting.

The present study sought to verify object size perception through internal modeling while lifting an object. Electromyography (EMG) activity of the upper limb muscles was recorded while 20 healthy females alternately lifted two containers of the same weight, but were unequal in size. When subjects lifted the small container, a significant increase was observed in the EMG activity. Most subjects determined that the small container was heavier than the large container, and predicted that the large container would be heavier than the small container due to size difference. The results may be explained by supporting that subjects predict object weight based on perception of size through internal modeling; however, predictions are cross-checked and modified through sensory feedback based on subjective weight.

Adult↗

PubMed2005

Apoptosis induced by 5-fluorouracil, cisplatin and paclitaxel are associated with p53 gene status in gastric cancer cell lines.

In a recent study, we evaluated the efficacy and toxicity of 5-fluorouracil (5-FU), cisplatin (CDDP), and 5-FU plus CDDP (FP treatment) in gastric cancer cell lines and examined the relationship between the response to FP treatment and apoptosis. Our study indicated that there may be prognostic value in measuring p53 prior to FP treatment, and that cancers with wild-type p53 may be better candidates for FP treatment than those with mutant-type p53 in gastric cancer patients. In the present study, because cells with mutant-type p53 are suggested to be less responsive to FP chemotherapy treatment, we examined the relationship between the response to paclitaxel and apoptosis in MKN45 and MKN28 human gastric cancer cell lines by flow cytometry. In both MKN45 and MKN28 cells, paclitaxel arrested cells in the G2/M phases of the cell cycle after 24 h. Additionally, in both MKN45 and MKN28 cells, paclitaxel produced a significant rise in the number of subG1-phase cells after 72 h by the flow cytometry histogram. From these results, our previous study suggests that cells with mutant-type p53 may be less responsive to FP treatment and the present study indicates that another anti-cancer drug like paclitaxel, which might be mediated by a p53-independent pathway, should be selected. These insights may provide a new strategy for gastric cancer chemotherapy, especially second-line chemotherapy or adjuvant chemotherapy.

Antineoplastic Agents↗

PubMed2005

The evaluation of gastric cancer sensitivity to 5-FU/CDDP in terms of induction of apoptosis: time- and p53 expression-dependency of anti-cancer drugs.

Clinical in vivo and in vitro studies have revealed pronounced gastric cancer activity using the combination of 5-fluorouracil (5-FU) and cisplatin (CDDP). In addition, the combination of 5-fluorouracil plus cisplatin (FP treatment) possesses synergistic cytotoxicity against gastric cancer. Sensitivity of two gastric cancer cell lines to anti-cancer drugs, 5-fluorouracil (5-FU) and/or cisplatinum (CDDP), was evaluated by use of either flow cytometric analysis (FACS) or morphological observation in terms of induction of apoptosis. In morphological observation, a new experimental technique was used in which cancer cells were distributed in thin collagen gel as one or two cell layers, and cultured with anti-cancer drugs. Thereafter, cells were stained with fluorescent Hoechst 33258 (Ho) and photographed, then stained with hematoxylin and eosin (H&E) and photographed again. Cell death patterns were determined by combining observations of Ho- and H&E-stained cells. While combined administration of 5-FU and CDDP did not induce apoptosis of MKN-28 (mutant-type p53), apoptotic cells were markedly observed in the case of MKN45 (wild-type p53). In addition, consecutive administration of CDDP for 3 h and 5-FU for 21 h effectively induced apoptosis of MKN45. These results indicated that the type of p53 expression in cancer cells could be a promising factor in predicting response to FP therapy and the administration of CDDP prior to 5-FU may be more effective in inducing apoptosis of gastric cancer cells with wild-type p53 expression. These data may provide evidence to support the idea that p53 expression is related to multidrug resistance (MDR) in FP therapy of gastric cancer cell lines.

Antineoplastic Agents↗

PubMed2004

Ileal perforation in a patient with high spinal cord injury: report of a case.

Assessing abdominal complications in patients who have previously suffered high spinal cord injury is very difficult because the resultant loss of sensory, motor, and reflux function of the abdominal wall can mask the typical signs of acute abdomen such as tenderness, muscle rigidity, and peritoneal rebound pain. We recently diagnosed a small intestinal perforation in a 77-year-old man with a C6-7 spinal cord injury sustained 14 years earlier. The patient was correctly diagnosed as having an acute abdominal condition, despite palsy of abdominal wall sensation. An emergency laparotomy was done and a 40-cm length of affected ileum, about 180 cm distal to the Treitz ligament, including a 1-cm perforation, was resected, followed by an end-to-end anastomosis. We report this case to raise awareness of the need for appropriate diagnosis and early surgical treatment of abdominal complications in spinal-cord-injured patients.

Aged↗

PubMed2004

Expression of p53 protein as a predictor of the response to 5-fluorouracil and cisplatin chemotherapy in human gastrointestinal cancer cell lines evaluated with apoptosis by use of thin layer collagen gel.

Apoptosis of the target cells is an important index in the assessment of the efficacy of cancer chemotherapy. We previously established a new experimental technique in which cancer cells are distributed in thin collagen gel as one or two cell layers, and cultured with anti-cancer drugs. The cells are stained with fluorescent Hoechst 33258 (Ho) and photographed, then with hematoxylin and eosin (H&E) and again photographed. The results show that most cell death patterns can be determined by combining observations of Ho and H&E-stained cells without the necessity for judging the apoptosis by electron microscopy. 5-fluorouracil (5-FU) and cisplatin (CDDP) are important anti-cancer drugs in the treatment of a variety of cancers. 5-FU or CDDP alone have shown significant effects in the treatment of gastric and colon cancers, and in addition, it has been shown that the combination of 5-FU plus CDDP (FP) therapy produces synergism greater than 5-FU or CDDP alone in gastrointestinal cancer. In this study, we evaluated the efficacy and toxicity of FP therapy in the gastric cancer cell lines MKN45, MKN28, and KATOIII and the colon cancer cell lines HCT116 and COLO320, and examined the relationship between the response to FP therapy and apoptosis. Additionally, we performed transfection of normal p53 gene into p53 mutant MKN28 cells and analyzed the impact of the p53 gene on a sensitivity test. Wild-type p53 in MKN45, HCT116, and COLO320 cells underwent significantly (p<0.01) more apoptosis than MKN28 and KATOIII cells possessing p53 mutant- and deficient-type, respectively, in FP therapy. Transfection of p53 to MKN28 cells resulted in a significantly (p<0.01) higher apoptotic index. From these results, we conclude that the p53 pathway allows induction of apoptosis in gastrointestinal cancers in FP therapy treatment, and that identification of the p53 type of a patient's cancer can be used to predict the success of FP therapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2004

p53 dependence and apoptosis in response to FP treatment with p53-transfected colon cancer cell lines by use of thin layer collagen gel.

The combination of 5-fluorouracil (5-FU) plus Cisplatin (CDDP) (FP treatment) possesses synergistic cytotoxicity against colon cancer. The molecular mechanisms by which chemotherapeutic agents induce apoptosis have been clarified by identifying apoptosis-related genes such p53 and bcl-2. We previously established a new experimental technique in which cancer cells are distributed in thin collagen gel as 1 or 2 cell layers. additionally, we evaluated the efficacy and toxicity of FP treatment in the gastric and colon cancer cell lines, and examined the relationship between the response to FP treatment and apoptosis. In these results we reported transfection of normal p53 gene into p53 mutant and analyzed the impact of the p53 gene in a sensitivity test. In this study, we examined induced apoptosis in colon cancer cell lines and the status of p53 expression in response to treatment of HCT116, COLO320, SW480 and DLD1 with 5-FU alone, CDDP alone and FP treatment under flow cytometric analysis. Transfection of SW480 and DLD1 cells was performed to compare the chemosensitivity of naturally occurring mutant-type p53 SW480 and DLD1 cells with neo-transfected SW480 and DLD1 cells and transfected SW480 and DLD1 cells. Appreciable apoptosis was induced in HCT116 and COLO320 (p53 wild-type) but not in SW480 and DLD1 cells (p53 mutant-type). Transfected SW480 and DLD1 cells underwent significantly more apoptosis (p<lt;0.001) than naturally occurring mutant-type p53 SW480 and DLD1 cells. p53 expression may further induce apoptosis in FP treatment. Patients with p53 wild-type may be better candidates for FP therapy than patients with p53 mutant-type in colon cancer. Therefore, we think that p53 may be also effective against colon cancer in FP therapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2003

Antiinflammatory and chondroprotective effects of the aminobisphosphonate incadronate (YM175) in adjuvant induced arthritis.

OBJECTIVE: Incadronate is a third-generation bisphosphonate that suppresses bone resorption and is used to treat skeletal disorders and prevent bone loss in pathological conditions. We evaluated its therapeutic potential and antiinflammatory effects in established adjuvant induced arthritis (AIA), a rat model of rheumatoid arthritis (RA). METHODS: Rats were administered incadronate subcutaneously at a dose of either 0.1 or 1.0 mg/kg/day, or 0.1 or 1.0 mg/kg/week, while a positive control group received phosphate buffered saline alone from Day 14 (after the onset of arthritis) to Day 42. The destruction of bone and cartilage and the antiinflammatory effects of incadronate in rats with established AIA were assessed during treatment, with reference to the arthritis index, hind paw volume, and radiological and histological examinations. To establish whether incadronate affects the migration of inflammatory cells, a chemotaxis assay was carried out using macrophage-like RAW 264.7 cells. Results. In vivo, incadronate suppressed the clinical manifestations of AIA in a dose-dependent manner. In vitro, the various concentrations of incadronate suppressed the migration of macrophages, but the viability and adhesion of these cells were not suppressed. CONCLUSION: Incadronate not only inhibits bone destruction but also reduces cartilage degeneration and joint inflammation in rats with established AIA. The mechanism underlying these antiinflammatory actions of incadronate may be attributable to the inhibition of macrophage migration to the site of inflammation. Bisphosphonates might be effective in preventing the progressive joint destruction and inflammation seen in patients with RA.

Animals↗

PubMed2003

[Relation between p53 expression of human colon cancer cell lines and induction of apoptosis by anticancer drugs].

The relation between p53 expression of human colon cancer cell lines and induction of apoptosis by anticancer drugs was examined experimentally. HCT116 had wild-type p53 expression and 5-fluorouracil (5-FU) in combination with cisplatinum (CDDP) increased both Sub G1 DNA content and the proportion of apoptotic cells. However, solitary administration of these drugs altered neither. Alternatively, for SW480 with mutant-type p53 expression, both combined administration and solitary administration of anticancer drugs showed minimal effect on Sub G1 DNA content and proportion of apoptotic cells. These results indicate that the type of p53 expression might play an important role in the determination of response to low-dose CDDP + 5-FU therapy in colon cancer patients.

Antineoplastic Agents↗

PubMed2002

Association of tannins and related polyphenols with the cyclic peptide gramicidin S.

The association of 10 different tannins and related polyphenols with gramicidin S, a cyclic peptide having a rigid beta-turn structure, has been examined using 1H-NMR spectroscopy. In the presence of pentagalloylglucose and epigallocatechin-3-O-gallate, the proton signals due to proline and the adjacent phenylalanine moieties selectively shifted to up field, suggesting a regioselective association with the beta-turn structure. The association was also supported by the observation of intermolecular nuclear Overhauser effects between epigallocatechin-3-O-gallate and the peptide. In contrast, ellagitannins, biogenetically derived from pentagalloylglucose, showed small and non-selective chemical shift changes, suggesting that interaction with these tannins is relatively weak. The hydrophobicity of the tannin molecules and the steric hindrance of the interaction site are thought to be important in the association.

Flavonoids↗