Biomedical subjects

Tomohiro Yamashita

Publications and source records attributed to Tomohiro Yamashita.

4 recordsLinked to original sources

PubMed2003

A method for screening polyphosphate-accumulating mutants which remove phosphate efficiently from synthetic wastewater.

The biological process for phosphorus removal from wastewater is based on the use of bacteria capable of accumulating inorganic polyphosphate (polyp). We previously showed that a phoU mutation leads to polyp accumulation in Escherichia coli. The phoU mutant could be easily screened on agar plates containing 5-bromo-4-chloro-3-indolyl-phosphate (X-P(i)) after N-methyl-N'-vitro-N-nitrosoguanidine (NTG) mutagenesis. Here, we demonstrate that this method is also useful for screening polyp-accumulating mutants of bacterial strains isolated from soil and activated sludge samples.

Journal Article↗

PubMed2002

Angiocentric immunoproliferative lesion of the lung.

Angiocentric immunoproliferative lesion (AIL) is the angiocentric and angiodestructive process of lymphoreticular cells with vascular invasion. AIL of the lung is rare. We treated a 57-year-old woman with AIL of the lung in whom chest radiography and computed tomography showed ground-glass opacity in the left lower lobe and lingular segment. Since macroscopical and intraoperative lung biopsy findings could not rule out the possibility of malignancy, including malignant lymphoma, we conducted left pneumonectomy. Immunohistological examination of the tumor showed that infiltrating lymphocytes consistent with AIL. Because tumor markers such as serum LDH and soluble IL-2 receptor increased postoperatively, we conducted systemic chemotherapy, after which elevated serum tumor markers decreased.

Female↗

PubMedDate not supplied

Extragastrointestinal stromal tumor of the greater omentum: case report and review of the literature.

Primary neoplasms of the greater omentum are rare. We report a case of omental tumors occurring in 58-year-old Japanese man. Ultrasonography showed multiple solid tumors in the abdomen and angiography identified the greater omentum as the precise location. The tumors were completely resected with the major part of the greater omentum and analyzed histologically, immunohistochemically, and genetically. Positive reactivity for CD117 (c-kit, a transmembrane tyrosine kinase receptor) and CD34, and the absence of TLS/FUS-CHOP rearrangement confirmed that the tumors were extragastrointestinal counterparts of a gastrointestinal stromal tumor. Although the higher mitotic activity measured by the Ki-67 labeling ratio suggests the malignant potential of this tumor, there was no recurrence at the 20-month follow-up.

Adult↗

PubMedDate not supplied

Diffusion weighted whole body imaging with background body signal suppression (DWIBS): technical improvement using free breathing, STIR and high resolution 3D display.

PURPOSE: To examine a new way of body diffusion weighted imaging (DWI) using the short TI inversion recovery-echo planar imaging (STIR-EPI) sequence and free breathing scanning (diffusion weighted whole body imaging with background body signal suppression; DWIBS) to obtain three-dimensional displays. MATERIALS AND METHODS: 1) Apparent contrast-to-noise ratios (AppCNR) between lymph nodes and surrounding fat tissue were compared in three types of DWI with and without breath-holding, with variable lengths of scan time and slice thickness. 2) The STIR-EPI sequence and spin echo-echo planar imaging (SE-EPI) sequence with chemical shift selective (CHESS) pulse were compared in terms of their degree of fat suppression. 3) Eleven patients with neck, chest, and abdominal malignancy were scanned with DWIBS for evaluation of feasibility. Whole body imaging was done in a later stage of the study using the peripheral vascular coil. RESULTS: The AppCNR of 8 mm slice thickness images reconstructed from 4 mm slice thickness source images obtained in a free breathing scan of 430 sec were much better than 9 mm slice thickness breath-hold scans obtained in 25 sec. High resolution multi-planar reformat (MPR) and maximum intensity projection (MIP) images could be made from the data set of 4 mm slice thickness images. Fat suppression was much better in the STIR-EPI sequence than SE-EPI with CHESS pulse. The feasibility of DWIBS was showed in clinical scans of 11 patients. Whole body images were successfully obtained with adequate fat suppression. CONCLUSION: Three-dimensional DWIBS can be obtained with this technique, which may allow us to screen for malignancies in the whole body.

Abdominal Neoplasms↗