Homopolymer-block-Alternating Copolymers Composed of Acrylamide Units: Design of Transformable Divinyl Monomers and Sequence-Specific Thermoresponsive Properties.

In this work, we synthesized an acrylamide-based terpolymer that is a block copolymer composed of an AB alternating copolymer and a C homopolymer. The key to the unprecedented achievement is rational design of an acrylate-acrylamide divinyl monomer carrying CF3-substituted salicylic acid ester bonds (AAm-CF3) to realize the efficient and selective cyclopolymerization as well as the quantitative transformation of the resultant cyclorepeating units. The selectivity in the cyclopolymerization and the pendant transformation ability were evaluated through reactivity ratios of the corresponding model monomers and quantitative aminolysis reactions of the model compound. The cyclopolymerization via the photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) process with a macrochain-transfer agent and subsequent aminolysis reaction afforded the homopolymer-block-alternating copolymer. The sequence-controlled terpolymer exhibited a very unique thermal response behavior in water that was strikingly different from the corresponding sequence-uncontrolled terpolymers, such as homopolymer-block-statistical copolymers and all statistical terpolymers, despite the fact that the structure cannot be distinguished by 1H NMR.

Increased GLUT1 expression and localization to Golgi apparatus of acinar cells in the parotid gland of Goto-Kakizaki diabetic rats.

OBJECTIVE: Patients with diabetes are known to have high salivary glucose levels. But the mechanisms are still unclear. We hypothesized that the topological changes of glucose transporters affect the salivary glucose level. METHODS: We used adult Goto-Kakizaki (GK) rats, an animal model of advanced diabetes, and Wistar rats as a control, with or without glucose load. The sections of salivary glands from the animals were processed for standard histological, immunohistochemical, and immunofluorescent staining. RESULTS: Parotid acinar cells of GK rats appeared like mucous filled with low-eosin-stained granules and possessing a flat nucleus located basally, whereas those of Wistar rats appeared as a typical serous gland with eosin-rich cytoplasm and a spherical nucleus. Cytoplasmic granules of GK rat parotid acinar cells showed no reaction of polysaccharide staining. In acinar cell cytoplasm of GK rats, intense GLUT1 immunoreactivity was observed compared to Wistar rats. By double immunostaining for GLUT1 and Golgi apparatus-specific markers, it was determined that GLUT1 was localized to the Golgi apparatus. By glucose loading in starved GK rats, the distribution of GLUT1-immunoreactive signals was spread out clearly from the apical side of the nucleus to the basolateral side. CONCLUSIONS: In rat model of diabetes, highly localized GLUT1 at Golgi apparatus in acinar cells seems to increase taking up cytoplasmic glucose to form exocytotic vesicles. This phenomenon may transform parotid glands from serous to mucous-like and result in saccharide-rich saliva.

Anatomical variation in the form of inter- and intra-individual laterality of the calcaneofibular ligament.

The lateral ligament complex of the ankle is involved in a large proportion of ankle sprains. The calcaneofibular ligament (CFL) is often involved in severe injuries. The purpose of this study was to evaluate the anatomical variation and laterality of the CFL to improve our understanding of the mechanisms of CFL-related injuries. This study utilized 110 paired ankles from 55 formalin-fixed Japanese cadavers (33 male and 22 female). The length and width of the CFL and the angle created by the CFL and long axis of the fibula (CF angle) were measured after exposing the CFL by careful dissection from the surrounding tissues. The results revealed that each parameter exhibited a wide range of values and showed unique patterns of frequency distribution, among which only the length was normally distributed. Among the parameters, only the CF angle showed no significant correlation with the other parameters. Analysis of laterality revealed that the mean left CF angle was significantly greater than the value on the opposite side (p < 0.05) and that the values of the bilateral CF angle showed no significant correlation at the individual level. The present results revealed not only detailed information regarding the CFL morphology, but also inter- and intra-individual laterality regarding the CFL traveling angle. It is likely that the differences in the quality and quantity of mechanical stress against each leg may have caused this morphologic laterality of the CFL.