Factors Affecting the Strength of Denture Repairs

Fracture of dentures is a common clinical finding in daily prosthodontic practice, resulting in great inconvenience to both patient and dentist. A satisfactory repair should be cost-effective, simple to perform, and quick; it should also match the original color and not cause distortion to the existing denture. Different repair materials, surface designs, and mechanical and chemical surface treatments have been recommended in order to obtain stronger repairs. This article reviews some of the available literature with regard to the most important factors that may influence the strength of denture repairs.     

Synchronous monitoring of external/internal respiratory motion: validity of respiration-gated radiotherapy for liver tumors

Purpose  

Four-dimensional (4D) radiotherapy, in particular respiration gating for the treatment of lung tumors, is gaining popularity. Its utility for other sites, however, has not been investigated fully. The purpose of this study was to see whether 4D therapy is feasible for liver tumors.     

The GDNF/Neurturin-Ret multicomponent receptor system

Glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) are structurally related neurotrophic factors that play crucial roles in the survival of peripheral sensory, sympathetic and dopaminergic neurons as well as motoneurons. Glial cell line-derived neurotrophic factordeficient mice showed lack of enteric neurons and renal agenesis or dysgenesis. Surprisingly, this phenotype was strikingly similar to that of ret proto-oncogene-deficient mice, suggesting that Ret tyrosine kinase might be a functional receptor for GDNF. Recent studies demonstrated that both GDNF and NTN were able to induce Ret tyrosine phosphorylation although they did not bind to Ret with high affinity, but novel glycosyl-phosphatidylinositol (GPI)-linked cell-surface proteins as ligand-binding components were required for Ret activation. Since GDNF and NTN are expected as therapeutic agents in neurodegenerative disorders such as Parkinson's disease and amyotrophic lateral sclerosis, the studies on the mechanisms of their biological actions through Ret would contribute to the development of new therapeutic strategies for these diseases.     

Carcinogenicity of Captafol in F344/DuCrj Rats

Captafol was administered at dietary levels of 0 (control), 750 and 1,500 parts per million (ppm) to groups of 50 male and 50 female F344/DuCrj rats for 104 weeks, and then all animals were maintained without captafol for a further 8 weeks, and killed in week 113. Renal cell carcinoma was found in eight of 50 male rats treated with 1,500 ppm and in one of 50 male rats treated with 750 ppm of captafol. The incidences of renal adenomas, including micro-adenomas, and basophilic altered cell tubules were significantly higher in both sexes treated with captafol than in controls, and the increases were apparently dose-dependent except that of adenomas in females. The incidences of neoplastic and preneoplastic lesions of the kidney in captafol-treated animals were higher in males than in females. Captafol also induced hepatocellular carcinomas in four of 50 female rats in the 1,500 ppm group. The incidences of hyperplastic (neoplastic) nodules and foci of cellular alterations in the liver were also significantly increased in both sexes treated with captafol, the increases being dose-dependent. In conclusion, captafol induced renal cell carcinomas in male rats and hepatocellular carcinomas in female rats.