Development of single nanometer-sized ultra fine oxygen bubbles to overcome the hypoxia-induced resistance to radiation therapy via the suppression of hypoxia-inducible factor-1α

学位記番号：医博甲1681

Loop Sequencer That Selects Music Loops Based on the Degree of Excitement

(Abstract to follow

Ectopic thymoma in the paratracheal region of the middle mediastinum: a rare case report and literature review

Abstract Background Thymomas generally arise from the thymus in the anterior mediastinum. Ectopic thymomas arising in the middle mediastinum are rare. We present a case of a thymoma arising from the ectopic thymic tissue in the right paratracheal region. Case presentation The patient was a 67-year-old male who underwent an enhanced-computed tomography examination as preoperative staging for colon cancer. A 20-mm nodule in the right paratracheal region was found incidentally. Fluorodeoxyglucose (FDG) accumulation was detected in this solitary nodule by FDG-positron emission tomography, mimicking an enlarged, possibly malignant lymph node. The tumor was removed by thoracoscopic surgery, and a postoperative pathological diagnosis of type AB thymoma was made. Foci of ectopic thymic tissues were found adjacent to the thymoma. The patient was disease-free and without recurrence 2 years postoperatively. Conclusions Including the present case, 13 cases of ectopic paratracheal thymoma have been reported in the English literature, all of which were found on the right side of the paratracheal region. Although ectopic thymomas in the paratracheal region are rare, thymomas may be considered as a differential diagnosis for a paratracheal nodule

Sense Transgene-Induced Post-Transcriptional Gene Silencing in Tobacco Compromises the Splicing of Endogenous Counterpart Genes

<div><p>Sense transgene-induced post-transcriptional gene silencing (S-PTGS) is thought to be a type of RNA silencing in which ARGONAUTE1 directs the small interfering RNA (siRNA)-mediated cleavage of a target mRNA in the cytoplasm. Here, we report that the altered splicing of endogenous counterpart genes is a main cause for the reduction of their mature mRNA levels. After the S-PTGS of a tobacco endoplasmic reticulum ω-3 fatty acid desaturase (<i>NtFAD3</i>) gene, 3′-truncated, polyadenylated <i>endo-NtFAD3</i> transcripts and 5′-truncated, intron-containing <i>endo-NtFAD3</i> transcripts were detected in the total RNA fraction. Although transcription proceeded until the last exon of the endogenous <i>NtFAD3</i> gene, intron-containing <i>NtFAD3</i> transcripts accumulated in the nucleus of the S-PTGS plants. Several intron-containing <i>NtFAD3</i> transcripts harboring most of the exon sequences were generated when an endogenous silencing suppressor gene, <i>rgs-CaM</i>, was overexpressed in the S-PTGS plants. These intron-containing <i>NtFAD3</i> splice variants were generated in the presence of <i>NtFAD3</i> siRNAs that are homologous to the nucleotide sequences of these splice variants. The results of this study indicate that the inhibition of <i>endo-NtFAD3</i> gene expression is primarily directed via the alteration of splicing and not by cytoplasmic slicer activity. Our results suggest that the transgene and intron-containing endogenous counterpart genes are differentially suppressed in S-PTGS plants.</p></div

The <i>endo-NtFAD3</i> transcripts in the nuclei.

<p>(<b>A</b>) Nuclear RNA was reverse transcribed with gene-specific primers (N7-LN for the <i>NtFAD7</i> gene and N3-AN for the <i>endo-NtFAD3</i> gene) and then converted into double-stranded cDNA. The cDNAs were analyzed by Illumina sequencing. The read sequences were mapped to the genomic sequences, and the relative distribution of the mapped read sequences is shown. The genomic structure of the <i>NtFAD7</i> and <i>NtFAD3</i> genes are shown at the top of the panel on the same x-axis scale of the corresponding graphs. The asterisks show the unusual distribution of the read sequences along the exon 2 and exon 6 sequences of the <i>endo-NtFAD3</i> gene. (<b>B</b>) Detection of intron-containing nuclear transcripts. Nuclear transcripts harboring exon 2 sequences were amplified with the N7-LN and exon 2-specific forward primers. Three types of transcripts were cloned, and their structures are illustrated. Nuclear transcripts harboring exon 6 sequences were amplified with the N3-AN and exon 6-specific forward primers. The exons are illustrated with open boxes; the introns are shown with solid bars.</p

siRNA distribution along the <i>NtFAD3</i> gene.

<p>The read numbers of siRNAs mapped to each exon or intron are shown. The number in the squares indicates the exon numbers, and the other number corresponds to the intron number. Each siRNA was classified by its 5′ terminal nucleotide position relative to the <i>NtFAD3</i> sequence.</p

Expression levels of the <i>endo-NtFAD3</i> gene.

<p>(<b>A</b>) The transcript levels of the <i>endo-NtFAD3</i> gene in the total RNA fraction. Each <i>endo-NtFAD3</i> transcript level was determined by qRT-PCR and normalized to the level of actin cDNA. The normalized value for the amount of <i>endo-NtFAD3</i> mRNAs of the WT plants was considered to be 100%, and other normalized values in the S20, S44-hemi, and S44-homo plants were calculated as a percentage of that of the WT plants. e1-e2 and e8-e9 indicate the detection of <i>endo-NtFAD3</i> transcripts that contain the proximal region (exon 1 to exon 2) and distal region (exon 8 to exon 9), respectively. e1-e7 indicates the detection of <i>endo-NtFAD3</i> transcripts that contain a region from exon 1 to exon 7. The values are the mean ± SD (n = 3). (<b>B</b>) Pol II occupancy in the WT and S44 plants. ChIP-qPCR experiments were performed using an anti-Pol II antibody to detect the binding level at the indicated locus in the WT and the S44 plants. The mean of qPCR of the S44 sample is reported relative to the EF-1α gene control and is shown as a relative value of the corresponding WT level shown as 1.0. The graphical representation shows the fold change as the mean of the three different biological (and two different technical) replicates. The error bars represent SD. Different letters on the graph represent significantly different means (<i>P</i><0.05).</p