Biomedical subjects

Emi Watanabe

Publications and source records attributed to Emi Watanabe.

4 recordsLinked to original sources

PubMed2006

[Status of measures against angiography room infection as determined by questionnaire].

Although the cleanliness of the angiography room and that of the operating room have long been equally attended to, the concept of Standard Precautions (including the basic measures and procedures to prevent infection) of the Centers for Disease Control and Prevention (CDC), 1996, as well as the introduction of transmission-based precautions, have been changing to preventive measures that are based on concrete measures. Therefore, a questionnaire was introduced in order to determine the actual status of countermeasures against infection used in the angiography room. The questionnaire was sent to 530 institutions, and 286 responded, a response rate of 54.0%. Its results significantly revealed the following: 1) unexpectedly low recognition of the need and importance for the CDC preventive measures against infection, 2) a considerable number of institutions continuing to perform the conventional preventive measures, 3) problems with education systems on preventive measures, and 4) handwashing, the most important measure against infection, failing to be adequately carried out noticeably among radiological technologists.

Angiography↗

PubMed2004

Analysis of genes related to expression of aromatase and estradiol-regulated genes during sex differentiation in Xenopus embryos.

We analyzed the genes that exhibit transcriptional changes during sex differentiation in Xenopus, using fluorescent differential display (FDD). Search was then undertaken for sequences that were homologous to the differentially displayed DNA. In this report, trans-acting factors of activating transcription factor 4 (ATF 4) and heat shock proteins were selected, on the basis of homology, from candidate genes thought to be involved in the expression cascade of aromatase and estrogen receptor genes. The stage and tissue specificities and the effect of estradiol treatment on the expression of these genes were then examined using real-time quantitative polymerase chain reaction (RQ-RT-PCR). The expression of ATF 4, a member of the ATF/cAMP-responsive element-binding protein (CREB) family of genes, peaked in the gonads at stage 50 of development. Interestingly, expression of the genes encoding the heat shock cognate protein70. II (Hsc70. II) and the heat shock protein 70 (Hsp70) binding protein was strongly activated at stages 50 and 48 of development, respectively. The three genes revealed a higher transcription activity in the gonads than in other tissues. Although the expression of all of the genes encoding ATF 4, aromatase, Hsc70. II, and Hsp70 binding protein was activated in vitro by estrogen treatment, that of Hsc70. II and Hsp70 binding protein was found to be transient.

Activating Transcription Factor 4↗

PubMed2002

Translational initiation regulators are hypophosphorylated in rat liver during ethionine-mediated ATP depletion.

Administration of ethionine to female rats is known to inhibit hepatic protein synthesis by reducing the level of hepatic ATP. Administration of methionine and/or adenine rapidly restores the ATP levels and protein synthesis. The ethionine administration causes a progressive disaggregation of hepatic polysomes, suggesting that the initiation step of protein synthesis is inhibited. Recent studies indicate that changes in initiation are associated with alterations in the phosphorylation states of translational initiation regulators such as eukaryotic initiation factor (eIF) 4E, eIF4E-binding protein 1 (4E-BP1), and the 70-kDa ribosomal protein S6 kinase (S6K1). We found that these initiation regulators are hypophosphorylated in rat liver during ethionine-mediated ATP depletion (60% of the control value). Furthermore, the restoration of the ATP levels by the administration of methionine and adenine brought about a complete recovery of the phosphorylation states of all these regulators. The present data suggest that hypophosphorylation of various initiation regulators represents the primary event in the ethionine-induced breakdown of polysomes and inhibition of protein synthesis in the liver. Possible involvement of mammalian target of rapamycin (mTOR), as a sensor of intracellular ATP level, was also discussed.

Adenosine Triphosphate↗

PubMed2002

[CT scanners with automatic focus alteration capability].

Heat accumulation in X-ray tubes results in disarrangement of focus owing to heat expansion of the anode. CT scanners with automatic focus alteration capability have been developed to counteract this problem. We compared CT scanners with and without focus alteration capabilities and discuss the effect of focus disarrangement on the CT images. Images were obtained when heat accumulation was high and low. Subtraction images were made to define the disarrangement of focus. A comparison was made between CT scanners with and without automatic focus alteration capability. ROI was selected and changes in CT values, SD, and slice thickness were observed under changing anode heat accumulation. Results indicated that images from both scanners showed disarrangement of the focus and elevation of CT values as anode heat accumulated. However, the scanner with automatic focus alteration produced images with less focus disarrangement from the center of the slice and less elevation of CT values. Scanners with automatic focus alteration are less prone to the focus disarrangement and elevation of CT values caused by anode heat accumulation and enable reproducible images to be obtained.

Electrodes↗