Biomedical subjects

Kyoko Okamoto

Publications and source records attributed to Kyoko Okamoto.

5 recordsLinked to original sources

PubMed2007

Ductal carcinoma in situ: correlations between high-resolution magnetic resonance imaging and histopathology.

PURPOSE: The aim of this retrospective study was to determine and correlate contrast-enhanced areas and multiple internal dark dots and lines on high-resolution magnetic resonance imaging (HR-MRI) with findings in surgical specimens of ductal carcinoma in situ (DCIS) and to evaluate the ability of HR-MRI to detect DCIS lesions and clarify HR-MRI features characteristic of DCIS. MATERIALS AND METHODS: This study retrospectively reviewed 11 patients diagnosed with DCIS who had undergone HR-MRI. Pathological findings and results of HR-MRI were compared, and causes of periductal enhancements were analyzed. RESULTS: In all patients, HR-MRI using microscopic coils revealed ductally, segmentally, or regionally enhanced areas containing multiple dark dots and lines, representing local enhancement of stroma adjacent to the mammary duct containing DCIS. Neovascularization, infiltration of inflammatory cells, and focal edema occurred in enhanced periductal stroma. Poorly enhanced linear or dot-like structures correlated with dilated mammary ducts displaying necrosis and tumor impaction. CONCLUSION: DCIS was successfully depicted on HR-MRI using a microscopy coil in all 11 cases. Ductal, segmental, or regional areas of enhancement with multiple dark dots and lines on HR-MRI corresponded to mammary glands containing DCIS with periductal enhancement.

Adult↗

PubMed2006

Prevention of geranylgeranoic acid-induced apoptosis by phospholipid hydroperoxide glutathione peroxidase gene.

Micromolar concentrations (0.5 approximately 5 microM) of all-trans geranylgeranoic acid (GGA) induced cell death in a guinea pig cell line, 104C1, whereas under the same conditions GGA was unable to kill 104C1/O4C, a clone established from 104C1 cells by transfection of them with the human phospholipid hydroperoxide glutathione peroxidase (PHGPx) gene. GGA (5 microM) induced a loss of the mitochondrial inner membrane potential (DeltaPsim) in 104C1 cells in 2 h, and their apoptotic cell death became evident in 6 h. On the other hand, 104C1/O4C cells were resistant to loss of DeltaPsim and showed intact morphology until at least 24 h after addition of 10 microM GGA. Dihydroethidine, superoxide-sensitive probe, was immediately oxidized 15 min after addition of GGA in both 104C1 and 104C1/O4C cells. The peroxide-sensitive probe 2',7'-dichlorofluorescin diacetate (H2-DCF-DA) was strongly oxidized in 104C1 cells 4 h after the addition of 2.5 microM GGA, but not in 104C1/O4C cells even in the presence of 10 microM GGA. The present results suggest that GGA induced a hyper-production of superoxide and subsequently peroxides, which in turn may have led to dissipation of the DeltaPsim and final apoptotic cell death in 104C1 cells.

Animals↗

PubMed2005

Thin-section CT assessment of spontaneous pneumomediastinum in interstitial lung disease: correlation with serial changes in lung parenchymal abnormalities.

PURPOSE: The purpose of this study was to analyze thin-section computed tomography (CT) appearances of interstitial lung diseases before and at the time of detection of pneumomediastinum, and to evaluate the relationship between pneumomediastinum and parenchymal changes on thin-section CT. MATERIALS & METHODS: We reviewed CT images before and at the time of detection of pneumomediastinum in 13 patients with idiopathic pulmonary fibrosis (8 patients) and collagen vascular diseases (5 patient). The extent of the total area of reticular opacity, increased opacity (ground-glass opacity and consolidation), and honeycombing were scored, and these scores were compared before and at the time of detection of pneumomediastinum. We also divided patients into two groups according to therapy received. Patients in group 1 experienced pneumomediastinum after or during treatment with corticosteroids or immunosuppressive agents for acute or subacute exacerbation of interstitial lung disease. Patients in group 2 experienced pneumomediastinum without therapy. RESULTS: The mean score of all patients for honeycombing significantly increased at the time of detection of pneumomediastinum (P=0.003). In group 1, the extent of increasing opacity had been decreased significantly at the time of detection of pneumomediastinum (P=0.028). In group 2, the mean CT score of reticular opacity, increasing opacity, and honeycombing significantly increased at the time of detection of pneumomediastinum (P=0.028, 0.018, and 0.018, respectively). CONCLUSIONS: Spontaneous pneumomediastinum associated with interstitial lung disease appears to have a tendency to occur under conditions of altered of parenchymal interstitial lesions.

Adrenal Cortex Hormones↗

PubMed2005

Initial experience of percutaneous vertebroplasty using single-plane C-arm fluoroscopy for guidance.

PURPOSE: The purpose of this study was to evaluate the feasibility and safety of percutaneous vertebroplasty (PVP) using single-plane C-arm fluoroscopy. MATERIALS AND METHODS: Lesions in the present study all comprised compression fractures with intact pedicles. A polymethylmethacrylate (PMMA) mixture was injected by the transpedicular approach under C-arm fluoroscopy using a lateral projection. Before and after PVP, the pain score was determined using visual analog scale methods. RESULTS: Between June 2002 and May 2004, we performed 31 PVPs in 17 patients during 22 treatment sessions. Underlying pathology comprised neoplasm-related compression fracture (n=9) and fractures attributed to osteoporosis (n=8). Mean pain score was 8.0 (range, 4.5-10) immediately before PVP, and 1.9 (range, 0-7) at 24 h after PVP. Mean time needed to perform PVP was 59 min. Mean time to approach a pedicle was 36 min (range, 20 min for 1 pedicle to 110 min for 3 pedicles). No complications requiring surgical intervention or exacerbating conditions beyond pre-treatment levels were noted. CONCLUSION: PVP using single-plane C-arm fluoroscopy for guidance is feasible, safe, and quick.

Adult↗

PubMed2002

Intergroup encounters in wild moor macaques (Macaca maurus).

We studied intergroup encounters among moor macaques at the Karaenta Nature Reserve, South Sulawesi, Indonesia. Group B has been observed on the basis of individual identification since 1988. We analyzed 85 encounters between members of Group B and members of neighboring groups from September 1990 to November 1998. The average frequency of intergroup encounters was 0.035/hour. Neither the presence of females in estrus nor rainfall had an effect on encounter frequency. Behaviors of moor macaques during intergroup encounters differed from those of Japanese macaques. In moor macaques, no intergroup interactions with body contact were observed during encounters, and females never directed aggression toward members of different groups. The present study did not confirm the prediction of the model of van Schaik (1989). Extension of the existing models is required to explain the difference in female dominance styles among macaques by socioecological factors.

Aggression↗