Polymyositis and fatal interstitial pneumonia following pelvic irradiation that led to unexpectedly severe adverse effects: a case report

Interstitial pneumonia (IP) sometimes precedes collagen vascular disease (CVD) onset. A patient with bladder cancer and mild IP received pelvic irradiation and experienced unexpectedly severe urinary toxicity followed by polymyositis onset and fatal IP exacerbation. Careful observation for “alarm adverse effects” of radiotherapy in IP patients may help predicting CVD onset.     

Successful endovascular isolation of a huge true anterior tibial artery aneurysm by the bi‐directional approach in a young patient

Anterior tibial artery aneurysms (ATAAs) are relatively rare entities. Most ATAAs are pseudoaneurysms resulting from trauma, infection, or iatrogenic injury. We observed a 33‐year‐old woman with a huge true ATAA who did not have any potential cause of pseudoaneurysm or risk factors for atherosclerosis or connective tissue disorder. Endovascular isolation by the bi‐directional approach was successfully performed, and the ATAA was totally excluded from the afferent blood flow. Distal flow of the anterior tibial artery was preserved, and pulsation of the dorsal pedis artery was also well preserved. Her postoperative course was uneventful, and follow‐up ultrasonography and magnetic resonance imaging revealed the ATAA shrinkage.     

The RNA-binding protein xCIRP2 is involved in apoptotic tail regression during metamorphosis in Xenopus laevis tadpoles

Frog metamorphosis induced by thyroid hormone (TH) involves not only cell proliferation and differentiation in reconstituted organs such as limbs, but also apoptotic cell death in degenerated organs such as tails. However, the molecular mechanisms directing the TH-dependent cell fate determination remain unclear. We have previously identified from newts an RNA-binding protein (nRBP) acting as the regulator governing survival and death in germ cells during spermatogenesis. To investigate the molecular events leading the tail resorption during metamorphosis, we analyzed the expression, the functional role in apoptosis, and the regulation of xCIRP2, a frog homolog of nRBP, in tails of Xenopus laevis tadpoles. At the prometamorphic stage, xCIRP2 protein is expressed in fibroblast, epidermal, nerve, and muscular cells and localized in their cytoplasm. When spontaneous metamorphosis progressed, the level of xCIRP2 mRNA remained unchanged but the amount of the protein decreased. In organ cultures of tails at the prometamorphic stage, xCIRP2 protein decreased before their lengths shortened during TH-dependent metamorphosis. The inhibition of calpain or proteasome attenuated the TH-induced decrease of xCIRP2 protein in tails, impairing their regression. These results suggest that xCIRP2 protein is downregulated through calpain- and proteasome-mediated proteolysis in response to TH at the onset of metamorphosis, inducing apoptosis in tails and thereby degenerating them.