The compatibilization of poly (propylene carbonate)/poly (lactic acid) blends in presence of core-shell starch nanoparticles.

A novel core-shell starch-based nanoparticles (CSS NPs) with a "hard" starch core and a "soft" poly (methyl acrylate) (PMA) shell was prepared and incorporated into a PPC/PLA blend. The excellent compatibilization of CSS NPs was revealed by atomic force microscope (AFM), differential scanning calorimetry (DSC) and rheological test. More importantly, due to the excellent compatibilization the resulted PPC/PLA/CSS blend exhibited a strikingly improved mechanical and thermal properties. Compared to PPC/PLA (60/40), the elongation at break of PPC/PLA/CSS (60/40/20) increased greatly from 15 % to 272 % without sacrificing the tensile strength. Besides, the heat distortion temperature (HDT) of PPC/PLA/CSS (60/40/20) was improved to 47.3 °C, which was 20.5 °C higher than that of the neat PPC. These results established a novel and efficient strategy to improve the compatibility of polymer blends and to prepare polymer blends with balanced toughness and stiffness.

The role of tensor veli palatini muscle (TVP) and levetor veli palatini [corrected] muscle (LVP) in the opening and closing of pharyngeal orifice of Eustachian tube.

CONCLUSION: This study developed an easy way to induce otitis media in an animal model and find the relation between tensor veli palatini muscle (TVP) and levetor veli palatini [corrected] muscle (LVP) in the opening and closing of the pharyngeal orifice of Eustachian tube. It was proved that otitis media is caused due to the dysfunction of Eustachian tube and the only muscle responsible for opening and closing of ETPO (Eustachian tube pharyngeal orifice) is TVP and LVP has no role in the opening and closing of the Eustachian tube pharyngeal orifice. OBJECTIVE: To develop valid animal model for otitis media of effusion and to study the relation of paratubular muscles in the functioning of Eustachian tube. METHODS: Two different methods were used to induce middle ear disease: (1) Excision of tensor veli palatini and levetor veli palatini [corrected] muscles (TVP and LVP); and (2) Injection of botulinum toxin type A on TVP and LVP. RESULT: Otomiscroscopic, tympanograph, and pathological examination showed the presence of middle ear disease in those animals whose TVP was excised and paralyzed, but on those groups of animals whose LVP was excised and paralyzed, abnormalities were seen.

Angiogenesis and cell proliferation in human craniopharyngioma xenografts in nude mice.

OBJECT: Craniopharyngioma is one of the most common congenital tumors of the sellar and suprasellar regions and accounts for between 4 and 6% of all intracranial tumors. Its oncogenesis and biological behavior have not been well studied, and neither a cell line nor an animal model have been established. To better understand the tumor and improve its clinical management, the authors investigated the angiogenesis and cellular proliferation in subcutaneous craniopharyngioma xenografts obtained by implanting human tumor cells into athymic nude mice. METHODS: Human craniopharyngioma cells obtained from surgical specimens were subcutaneously implanted into BALB/c-nu/nu nude mice to establish a preliminary animal model of a transplanted tumor. Immunohistochemical staining with streptavidin-peroxidase complex was used to identify the cell phenotype and to evaluate the angiogenesis and proliferation in the xenografts. Expression of cytokeratin, minichromosome maintenance deficient 6 (MCM6) protein, and endothelial cell marker CD34 on the xenograft sections were assayed quantitatively by computer-assisted microscopy. Twenty-seven surviving subcutaneous xenografts were obtained in 15 nude mice. The total implantation success rate was 28.12% (adamantine epithelioma [AE], 37.50%; squamous papillary tumor [SPT], 18.75%). Formation of capillaries and cell proliferation were observed in all of these xenografts. Microvessel density and degree of MCM6 immunostaining were positively correlated in the surviving grafts (r = 0.410, p < 0.05), but there was no significant difference in these variables between the AE and SPT groups (p > 0.05). CONCLUSIONS: A preliminary animal model of human craniopharyngioma was established in the nude mouse by heterotopic implantation. Surviving xenografts maintained their vascularization and proliferation activities until harvesting at 12 weeks.