Dose responses of scattered- and direct-X-ray-irradiated CR-39 and methylviologen-encapsulated silica nanocapsule-doped CR-39 and their mechanisms

The photoexcited emissions of direct- and scattered-X-ray-irradiated CR-39 and methylviologen-encapsulated silica nanocapsule (MV2+@SiO2 NC)-doped CR-39 were observed, and they showed a dose response. The benzophenone radical was formed in a shallow trap in CR-39 upon X-ray irradiation from 10 to 30 Gy, and the fluorescence intensity increased with the dose. Methylviologen in SiO2 NCs competitively captured electrons generated by X-ray irradiation, and the captured electrons were reverse transferred to the shallow traps with time. A minimum dose rate of 300 µGy/s was observed between 1 and 5 Gy. Finally, a dose response of less than 2 mGy for scattered X-rays was obtained in this system

Implications of heat shock / stress proteins for medicine and disease

Heat shock/ stress proteins (HSPs) are crucial for maintenance of cellular homeostasis during normal cell growth and for survival during and after various cellular stresses. The HSP70 family functions as molecular chaperones and reduces stress-induced denaturation and aggregation of intracellular proteins. In addition to the chaperoning activities, HSP70 has been suggested to exert its protective action by protecting mitochondria and by interfering with the stress-induced apoptotic program. The biochemical and functional properties of HSPs observed in cultured cells may be relevant to organs and tissues in whole animals. The activation of the hypothalamic-pituitary-adrenal axis and the sympathetic nerve system elicits the stress response in selected peripheral tissues the HSP70 expression in the vasculature and stomach increases resistance against hemodynamic stress and stress-induced mucosal damage, respectively. Gastric mucosa pretreated with mild irritants acquires a tolerance against subsequent mucosal-damaging insults. This phenomenon is known as “adaptive cytoprotection”. Transient ischemia also induces ischemic tolerance in the brain and heart, which is called “ischemic preconditioning”. The heat shock response is believed to contribute to the acquisition of the tolerance. The therapeutic applications of chaperone inducers that induce HSPs without any toxic effect are also introduced

チョウ カイテン イジョウショウ オ トモナッタ オウコウ ケッチョウガン ニ タイシテ フククウキョウ ホジョカ ケッチョウ セツジョジュツ オ シコウ シタ 1レイ

A ６４-year-old woman with complaint of intermittent abdominal pain for one year was admitted to our hospital. She had been diagnosed as transverse colon cancer by barium enema and colonoscopy at the former hospital. Abdominal enhanced CT showed that the duodenal third portion was not detected at the back of superior mesenteric vessel. She underwent laparoscopic surgery based on a diagnosis of transverse colon cancer with intestinal malrotation. We could perform laparoscopic-assisted transverse colectomy using abdominal enhanced CT which was effective for not only preoprerative diagnosis of accompany of intestinal malrotation but also anatomical anomalies of vessels. The right sided colon which was not fixed to the retroperitoneum in cases with intestinal malrotation could be pulled out easily from the small incision wound. We also considered that colectomy and dissection of its lymph nodes to these cases could be safety performed using by laparoscopy and through small laparotomy

Role of oxidative stress in germ cell apoptosis induced by di(2-ethylhexyl)phthalate.

Phthalate esters have been used extensively as plasticizers of synthetic polymers. Recent studies have revealed that these esters induce atrophy of the testis, although its pathogenesis remains unknown. The present study describes the possible involvement of oxidative stress in the pathogenesis of atrophy of the rat testis induced by di(2-ethylhexyl)phthalate (DEHP). Biochemical and immunohistochemical analysis revealed that oral administration of DEHP increased the generation of reactive oxygen species, with concomitant decrease in the concentration of glutathione and ascorbic acid in the testis, and selectively induced apoptosis of spermatocytes, thereby causing atrophy of this organ. Oxidative stress was selectively induced in germ cells, but not in Sertoli cells, treated with mono(2-ethylhexyl)phthalate (MEHP), a hydrolysed metabolite of DEHP. Furthermore, MEHP selectively induced the release of cytochrome c from mitochondria of the testis. These results indicate that oxidative stress elicited by MEHP principally injured mitochondrial function and induced the release of cytochrome c, thereby inducing apoptosis of spermatocytes and causing atrophy of the testis

In Vitro Modeling of Blood-Brain Barrier with Human iPSC-Derived Endothelial Cells, Pericytes, Neurons, and Astrocytes via Notch Signaling

The blood-brain barrier (BBB) is composed of four cell populations, brain endothelial cells (BECs), pericytes, neurons, and astrocytes. Its role is to precisely regulate the microenvironment of the brain through selective substance crossing. Here we generated an in vitro model of the BBB by differentiating human induced pluripotent stem cells (hiPSCs) into all four populations. When the four hiPSC-derived populations were co-cultured, endothelial cells (ECs) were endowed with features consistent with BECs, including a high expression of nutrient transporters (CAT3, MFSD2A) and efflux transporters (ABCA1, BCRP, PGP, MRP5), and strong barrier function based on tight junctions. Neuron-derived Dll1, which activates Notch signaling in ECs, was essential for the BEC specification. We performed in vitro BBB permeability tests and assessed ten clinical drugs by nanoLC-MS/MS, finding a good correlation with the BBB permeability reported in previous cases. This technology should be useful for research on human BBB physiology, pathology, and drug development