Expanding the clinical phenotype of individuals with a 3-bp in-frame deletion of the NF1 gene (c.2970_2972del): an update of genotype–phenotype correlation

Purpose: Neurofibromatosis type 1 (NF1) is characterized by a highly variable clinical presentation, but almost all NF1-affected adults present with cutaneous and/or subcutaneous neurofibromas. Exceptions are individuals heterozygous for the NF1 in-frame deletion, c.2970_2972del (p.Met992del), associated with a mild phenotype without any externally visible tumors. Methods: A total of 135 individuals from 103 unrelated families, all carrying the constitutional NF1 p.Met992del pathogenic variant and clinically assessed using the same standardized phenotypic checklist form, were included in this study. Results: None of the individuals had externally visible plexiform or histopathologically confirmed cutaneous or subcutaneous neurofibromas. We did not identify any complications, such as symptomatic optic pathway gliomas (OPGs) or symptomatic spinal neurofibromas; however, 4.8% of individuals had nonoptic brain tumors, mostly low-grade and asymptomatic, and 38.8% had cognitive impairment/learning disabilities. In an individual with the NF1 constitutional c.2970_2972del and three astrocytomas, we provided proof that all were NF1-associated tumors given loss of heterozygosity at three intragenic NF1 microsatellite markers and c.2970_297

Characterisation of undrained shear strength using statistical methods

Frontiers in Offshore Geotechnics II - Proceedings of the 2nd International Symposium on Frontiers in Offshore Geotechnics661-66

Tissue-engineered cartilage composited with expanded polytetrafluoroethylene (ePTFE) membrane

The authors report a new approach using expanded polytetrafluoroethylene (ePTFE) membrane as pseudoperichondrium to support engineered cartilage. Swine auricular chondrocytes were isolated and mixed with fibrin glue to achieve a final concentration of 40 x 10(6) cells per milliliter. The fibrin glue-cell suspension was assembled with ePTFE and the constructs were implanted into the dorsal subcutaneous pockets of nude mice for 12 weeks. Two experimental groups were prepared in this study: (1) ePTFE placed in the central part of the specimen in group 1 and (2) ePTFE placed on the outside surfaces in group 2. All specimens were subjected to histological and gross mechanical evaluation. Histological results showed neocartilage formation in both groups. The integration between neocartilage and ePTFE forms a tight bond. Gross mechanical testing revealed that the flexibility of specimens in group 2 were similar to that of native cartilage with intact perichondrium, whereas the flexibility of specimens in group 1 were poor. From these results the authors conclude that it is possible to produce a tissue-engineered cartilage framework using ePTFE as a support material to simulate the perichondrium