Biomedical subjects
Publications and source records attributed to T Sameshima.
One hundred and two isolates of Escherichia coli O157:H7 derived from cattle were characterised by random amplification of polymorphic DNA (RAPD). Four different RAPD profiles were observed. Based on the combined results of RAPD typing and toxin genotyping, the isolates could be divided into six distinct groups.
BACKGROUND: Chondroid chordoma is a rare variant of chordoma and is usually located in the sphenooccipital region. This tumor shows clinical and histologic features common to both conventional chordoma and low grade chondrosarcoma and has a better prognosis than either of those lesions. To our knowledge, there has been no English language report describing its cytologic features. CASE: The cytologic features of skull base chondroid chordoma observed in intraoperative crush and touch preparations from a 33-year-old female are reported. Touch cytology revealed round or stellate cells distributed in a mucoid background without a typical epithelial cordlike arrangement. The cells had variably vacuolated cytoplasm and round or oval nuclei and showed slight cellular pleomorphism. May-Giemsa staining was superior to Papanicolaou staining in demonstrating the mucoid matrix and vacuolated cytoplasm of the tumor cells. Additionally, crush preparations were effective in demonstrating well-differentiated chondroid elements. Immunocytochemistry with positivity for S-100 protein and cytokeratins was an essential adjunct in the cytologic diagnosis of chordoma and helped in distinguishing it from other chondrogenic tumors. CONCLUSION: It is possible and advantageous to diagnose chondroid chordoma with a combination of cytologic and immunocytochemical studies of intraoperative crush and touch preparations in conjunction with clinical and radiographic information.
The metabolites of fentanyl (l), which has been widely used as a neuroleptic analgesic agent, were identified in urine of rats by gas chromatography-mass spectrometry combined with a stable-isotope tracer technique. After the oral administration of an equimolar mixture of l and deuterium-labeled l (l/l-d5), the urinary metabolites were extracted with chloroform at pH 9.0. Extracts were derivatized and analyzed by GC/MS. Metabolites were identified by the presence of doublet ion peaks separated by 5 amu, and chemical structures were established from analyses of fragmentation pathways. The metabolites were identified as 4-N-(N-propionylanilino)-piperidine, 4-N-(N-hydroxypropionylanilino)piperidine, 4-N-(N-propionylanilino) hydroxypiperidine, 1-(2-phenethyl)-4-N-(N-hydroxypropionylanilino)piperidine and 1-(2-phenethyl)-4-N-(N-propionylanilino)hydroxypiperidine. These metabolites, together with unchanged l, were also detected in urine of rats receiving l/l-d5 intravenously, by selected-ion monitoring of the specific cluster ions.
The effects of halogenated inhalational anesthetics, viz. halothane, enflurane, isoflurane and sevoflurane, on ischemic rat kidneys were studied through the response of renal gamma-glutamyl transpeptidase in the brush border of proximal tubules to monoclonal antibodies. Brush border staining characteristics were evaluated as follows: a) continuous (normal), b) discontinuous (damaged) and c) indistinct (necrotic). The isoflurane group had significantly fewer damaged and/or necrotic proximal tubules compared to the other groups. These results suggest that isoflurane is the most appropriate inhalational anesthetic when renal circulation is impaired.
To establish whether the indicators of oxygen metabolism reflects the improvement in tissue oxygenation during therapy, twelve rabbits subjected to progressive hemorrhage followed by retransfusion were studied. The changes in oxygen delivery (DO2), oxygen consumption (QO2), oxygen extraction ratio (O2ER), arterial lactate concentration, venous-arterial difference in PcO2 (v-aDPcO2) and arterio-venous difference in pH (a-vDpH) were analyzed during two phases (above and below) the critical DO2 with the regression coefficient (slope). The main findings during the transfusion were: a) the slope, when compared during the two phases was not significantly different for O2ER, v-aDPcO2 or a-vDpH, while during hemorrhage each variable showed a significantly different slope, b) in the phase below the critical DO2, the slope was significantly less steep than that during hemorrhage for lactate and v-aDPcO2, c) in the phase above the critical DO2, lactate alone had significantly steeper slope than that during hemorrhage. In conclusion, it is suggested that the changes in QO2 best reflect the recovery from tissue hypoxia.