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Biomedical subjects

Tsuyoshi Kawano

Publications and source records attributed to Tsuyoshi Kawano.

9 recordsLinked to original sources
PubMed2006

Disruption of ins-11, a Caenorhabditis elegans insulin-like gene, and phenotypic analyses of the gene-disrupted animal.

The insulin/insulin-like growth factor-I signaling (IIS) pathway regulates larval diapause, adult lifespan, fat metabolism, and stress-resistance in the nematode Caenorhabditis elegans. One of 38 C. elegans insulin-like genes, ins-11, was disrupted and phenotypic analyses of the gene-disrupted animal were performed. The gene-disruption exhibited a significant influence on the adult lifespan. It antagonized the lifespan extension induced by RNAi knockdown of another insulin-like gene, ins-7. Hence ins-11 appears to be necessary for lifespan extension caused by a decrease in the IIS pathway. This is the first description of gene-disruption of the C. elegans insulin-like gene that suppresses the lifespan extension.

Animals↗
PubMed2005

Brevicompanine C, cyclo-(D-Ile-L-Trp), and cyclo-(D-Leu-L-Trp), plant growth regulators from Penicillium brevi-compactum.

New plant growth regulators, named brevicompanine C (1), cyclo-(D-Ile-L-Trp) (2), and cyclo-(D-Leu-L-Trp) (3), have been isolated from Penicillium brevi-compactum Dierckx, and their structures have been established by spectroscopic methods including 2D NMR and chiral TLC analysis. Plant growth activities of 1, 2, and 3 have been examined using lettuce seedling bioassay methods. All compounds accelerated the root growth of the seedlings in proportion to their concentration from 1 to 100 mg/L.

Amino Acid Sequence↗
PubMed2005

Lifespan extending activity of substances secreted by the nematode Caenorhabditis elegans that include the dauer-inducing pheromone.

The nematode Caenorhabditis elegans yields a substance(s) inducing the larval diapause, called dauer-inducing pheromone. We discovered that the crude pheromone extract extends the adult lifespan in the animal. This extension does not occur in the mutant animal, in which expansion of the lifespan caused by other mutations reducing insulin signaling is suppressed. This is the first description concerning the relevancy of the pheromone to the longevity in the animal.

Aging↗
PubMed2004

Value of 18F-FDG PET in the detection of peritoneal carcinomatosis.

PURPOSE: Peritoneal carcinomatosis can be difficult to diagnose using computed tomography (CT). The purpose of this study was to evaluate the role of 2-(fluorine 18) fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the detection of peritoneal carcinomatosis. METHODS: We reviewed the CT and FDG PET radiological reports and clinical charts of 18 patients with peritoneal carcinomatosis and 17 cancer patients without peritoneal carcinomatosis. We also assessed FDG PET scans from 20 healthy volunteers as a baseline study. The maximum standardised uptake values (SUVmax) over peritoneal lesions in cancer patients and over the area of most intense intestinal uptake in healthy volunteers and cancer patients without peritoneal carcinomatosis were measured. RESULTS: The sensitivity and positive predictive value (PPV) of combined FDG PET and CT were superior to those of CT alone for the detection of peritoneal lesions (sensitivity: 66.7% vs 22.2%, p<0.025; PPV: 92.3% vs 50.0%, p<0.05). The most frequent pattern of FDG uptake in patients with peritoneal carcinomatosis was abnormally intense focal uptake near the abdominal wall. An SUVmax threshold of 5.1 produced a diagnostic accuracy of combined FDG PET and CT of 78%. The additional information provided by FDG PET allowed a more accurate diagnosis in 14 patients (40.0%), and led to alteration of the therapeutic strategy in five (14.3%) of the enrolled cancer patients. CONCLUSION: We found that use of an intra-abdominal FDG uptake cut-off value for SUVmax of >5.1 assists in the diagnosis of peritoneal carcinomatosis. FDG PET may play an important role in the clinical management of patients with suspected peritoneal carcinomatosis.

Carcinoma↗
PubMed2004

The clinical relevance of thymic fluorodeoxyglucose uptake in pediatric patients after chemotherapy.

The purpose of this study was to clarify the clinical implications of thymic fluorodeoxyglucose (FDG) uptake after chemotherapy in pediatric patients with malignant disease. Twenty-two pediatric patients, aged 0-17 years (mean 7.0 years), who had undergone FDG positron emission tomography (PET) were examined retrospectively. A total of 48 FDG-PET scans of the 22 patients were reviewed. Seven PET scans were recorded before the initial chemotherapy, and the remaining 41 scans were conducted during and after chemotherapy. Thymic FDG uptake was evaluated using standardized uptake value (SUV) analysis. The effect of chemotherapy on thymic FDG uptake was assessed by comparing SUV before, during, and after chemotherapy. The change in thymic FDG uptake with increasing time after the completion of chemotherapy was also assessed. Clinical laboratory data including number of white blood cells (WBCs), erythrocytes (RBCs), platelets, plasma glucose level and differential white blood count were analyzed for their association with thymic FDG uptake. Thymic FDG uptake in patients during chemotherapy was significantly lower than that in patients before chemotherapy (mean+/-SD 1.71+/-0.48 vs 2.27+/-0.32, respectively, P<0.01). Thymic FDG uptake in patients after chemotherapy was significantly higher than that in patients during chemotherapy (mean+/-SD 2.74+/-0.70 vs 1.71+/-0.48, respectively, P<0.01). A significant relationship between thymic FDG uptake and interval after completion of chemotherapy (r=0.74, P<0.0001) was observed. Significant relationships between blood counts (WBCs, RBCs, and platelets) and thymic FDG uptake were also observed. Comparison of the differential white blood count and thymic FDG uptake revealed a significant relationship only with lymphocyte count. Thymic FDG uptake in pediatric patients after completion of chemotherapy should not be mistaken as recurrent or metastatic thymic malignancy. Thymic FDG uptake appears to be associated with thymic function or hematopoietic function in bone marrow. Interpretation of FDG-PET must be made with this consideration in mind.

Adolescent↗
PubMed2003

Betagamma-dehydrocurvularin and related compounds as nematicides of Pratylenchus penetrans from the fungus Aspergillus sp.

The new nematicidal compound, betagamma-dehydrocurvularin (1), together with three known compounds, alphabeta-dehydrocurvularin (2), 8-beta-hydroxy-7-oxocurvularin (3) and 7-oxocurvularin (4), were isolated from the culture filtrate and mycelial mats of Aspergillus sp. The structures of 1-4 were established by spectroscopic methods including 2D NMR. The biological activities of 1-4 were examined by bioassays with root-lesion nematodes, and lettuce and rice seedlings.

Animals↗
PubMed2003

Cloning and characterization of a Caenorhabditis elegans cDNA encoding a new insulin/IGF-like peptide.

A Caenorhabditis elegans cDNA encoding a new insulin/IGF-like peptide was cloned and examined. The predicted peptide shows significant sequence similarity with the peptide Ceinsulin-1 reported previously and contains a characteristic insertion consisting of three residues in the putative B domain as with the Ceinsulin-1. The gene expression pattern during development is almost identical to that of Ceinsulin-1. The predicted tertiary structure of the peptide is quite similar to that of Ceinsulin-1, and their predicted receptor-recognition surfaces also closely match. These facts suggest that both peptides could recognize the same receptor.

Amino Acid Sequence↗
PubMed2002

Myxostiolide, myxostiol, and clavatoic acid, plant growth regulators from the fungus Myxotrichum stipitatum.

New plant growth regulators, named myxostiolide (1), myxostiol (2), and clavatoic acid (3), have been isolated from Myxotrichum stipitatum, and their structures have been established by spectroscopic methods including 2D NMR. The biological activities of 1, 2, and 3 have been examined using tea pollen and lettuce seedling bioassay methods. With tea pollen, compound 1 inhibited the pollen tube growth to 14% of control at a concentration of 100 mg/L. With lettuce seedlings, compound 2 accelerated the root growth from 1 mg/L to 100 mg/L and compound 3 inhibited the root growth, to 52% of control, at a concentration of 100 mg/L.

Benzoates↗