Baculoviral expression of telomerase in primary human fibroblasts to rejuvenate cells for tissue engineering.

Tissue engineering involves the use of synthetic or natural materials as a scaffold to support the growth of replacement tissue or organs. The use of autologous cells to populate the scaffold avoids problems associated with rejection; however, a major limitation of this approach is the finite lifespan of primary cells in culture. This finite lifespan is due to the shortening of telomeres, short repetitive sequences of DNA located at the ends of eukaryotic chromosomes. Ectopic expression of telomerase reverse transcriptase (hTERT) is able to reconstitute telomerase activity and maintain the length of telomeres. This study investigated an alternative gene delivery vector, baculovirus, for the expression of hTERT in primary human cells. A recombinant baculovirus was used to efficiently deliver the hTERT gene to primary fibroblasts and the telomerase enzyme was found to be active. Although no increase in telomere length was detected, expression of hTERT in primary fibroblasts resulted in a significant extension of replicative lifespan. To our knowledge this is a novel attempt to use a recombinant baculovirus for the extension of cellular lifespan by exogenous expression of telomerase.

Construct validity of neuropsychological instrumentation with a learning disabled population.

The construct validity of the Reitan-Indiana Neuropsychological Test Battery (R-INB)for Children with a learning disabled population was examined. Forty-two subjects classified as learning disabled also were administered the Wechsler Intelligence Scale for Children-Revised (WISC-R) and Wide Range Achievement Test (WRAT) subtests. Factor analysis of the data revealed four factors: verbal intelligence, psychomotor speed, achievement, and memory. Evidence from this study indicates that the overall construct paradigm as conceptualized by the author of the R-INB does not exist. Implications of these findings are discussed.