Double-layered two-directional somatopleural cell migration during chicken body wall development revealed with local fluorescent tissue labeling.

The thoracic ventral body wall consists of the rib, the sternum, the intercostal muscles, and the connective tissues surrounding them. The ribs and the intercostal muscles are derived from the somite. The connective tissues are derived from the somatic layer of the lateral plate mesoderm, somatopleure. The lateral growth of the somatopleure forms the primary ventral body wall. The migration of somitic cells into the somatopleure generates the secondary body wall. As the migrating behavior of the somatopleural cells during secondary body wall formation is still unclear, we investigate here the migratory behavior of the somatopleural cells in the thorax during chicken ventral body wall development by labeling the thoracic somatopleural cells one-somite-wide by DiI labeling or gene transfection of the enhanced green fluorescent protein and observe their distribution assisted by the tissue-clearing technique FRUIT. Our labeling experiments revealed the rostral migration of the somatopleural cells into a deep part of the thoracic body wall in embryonic day 6.5 chickens. For embryonic day 8.5 chickens, these deep-migrating somatopleural cells were found around the sternal ribs. Thus, we identified the double-layered two-directional migrating pathways of the somatopleural cells: the rostral migration of the deep somatopleural cells and the lateral migration of the superficial somatopleural cells. Our findings imply that the rostral migration of deep somatopleural cells and the lateral migration of superficial ones might be associated with the developing sternal ribs and the innervation of the thoracic cutaneous nerves, respectively.

From the primitive streak to the somitic mesoderm: labeling the early stages of chick embryos using EGFP transfection.

Mesoderm is derived from the primitive streak. The rostral region of the primitive streak forms the somitic mesoderm. We have previously shown the developmental origin of each level of the somitic mesoderm using DiI fluorescence labeling of the primitive streak. We found that the more caudal segments were derived from the primitive streak during the later developmental stages. DiI labeled several pairs of somites and showed the distinct rostral boundary; however, the fluorescence gradually disappeared in the caudal region. This finding can be explained in two ways: the primitive streak at a specific developmental stage is primordial of only a certain number of pairs of somites, or the DiI fluorescent dye was gradually diluted within the primitive streak by cell division. Here, we traced the development of the primitive streak cells using enhanced green fluorescent protein (EGFP) transfection. We confirmed that, the later the EGFP transfection stage, the more caudal the somites labeled. Different from DiI labeling, EGFP transfection performed at any developmental stage labeled the entire somitic mesoderm from the anterior boundary to the tail bud in 4.5-day-old embryos. Furthermore, the secondary neural tube was also labeled, suggesting that not only the somite precursor cells but also the axial stem cells were labeled.

[Two cases of unresectable advanced gastric cancer treated with S-1, CDDP and trastuzumab].

We report two cases of unresectable advanced gastric cancer treated with S-1, CDDP and trastuzumab. A significant reduction of tumors was observed in these cases. A 77-year-old man was diagnosed as unresectable gastric cancer. The pathological diagnosis was tub2 and human epidermal growth factor receptor 2(HER2)positive(3+IHC method). We started chemotherapy(S-1+CDDP+trastuzumab). After 2 courses of S-1+CDDP, the findings of upper gastrointestinal endoscopy and CT were much improved to PR. But after 6 courses of S-1+CDDP, they worsened to PD. The regimen of chemotherapy was changed to weekly paclitaxel. The other patient, a 68-year-old woman, was diagnosed as far advanced gastric cancer. The pathological diagnosis was tub2=por2 and HER2 positive(3+IHC method). We started chemotherapy(S- 1+CDDP+trastuzumab). After 3 courses of S-1+CDDP, the tumor reduced significantly to PR. We continued this regimen. From the result of the ToGA trial, addition of trastuzumab to chemotherapy(capecitabine+CDDP or fluorouracil+CDDP) has been recommended as a new standard first-line regimen for HER2-positive advanced gastric cancer. But there is no evidence that trastuzumab added to the other regimen improved survival in patients with advanced gastric cancer. It is necessary to conduct a clinical trial to evaluate the treatment effect of this chemotherapy.