Biomedical subjects

Jane Paulsen

Publications and source records attributed to Jane Paulsen.

3 recordsLinked to original sources

PubMed2007

"No one else sees the difference: "family members' perceptions of changes in persons with preclinical Huntington disease.

Manifestations of Huntington disease (HD) prior to clinical diagnosis are not well understood. This study documents adult family members' perceptions of changes and their attempts to manage these changes in persons who had received a positive predictive molecular HD test prior to clinical diagnosis. Data were obtained from 19 adult family members in six focus groups in the US and Canada and one individual interview in the US. Changes reported by family members included problems in cognition and behavior, which are consistent with prior reports. In addition, family members observed changes in motor functioning, the ability to complete usual activities at work or at home, and interpersonal relationships with family and friends. Family members attempted to manage these changes by taking on new responsibilities and preparing for future caregiving. Lack of information about preclinical HD, difficulty in understanding changes that may represent early stages of HD, and efforts to maintain secrecy of the preclinical HD situation contribute to compromising the abilities of family members to respond to changes in the person with preclinical HD. Findings provide insights into alterations in cognition, behavior, and functioning observed by the family members prior to clinical diagnosis. Findings further support the need for a more comprehensive assessment and management of early HD symptoms as well as support for family members.

Adult↗

PubMed2006

Evaluation of the GTRACT diffusion tensor tractography algorithm: a validation and reliability study.

Fiber tracking, based on diffusion tensor imaging (DTI), is the only approach available to non-invasively study the three-dimensional structure of white matter tracts. Two major obstacles to this technique are partial volume artifacts and tracking errors caused by image noise. In this paper, a novel fiber tracking algorithm called Guided Tensor Restore Anatomical Connectivity Tractography (GTRACT) is presented. This algorithm utilizes a multi-pass approach to fiber tracking. In the first pass, a 3D graph search algorithm is utilized. The second pass incorporates anatomical connectivity information generated in the first pass to guide the tracking in this stage. This approach improves the ability to reconstruct complex fiber paths as well as the tracking accuracy. Validation and reliability studies using this algorithm were performed on both synthetic phantom data and clinical human brain data. A method is also proposed for the evaluating reliability of fiber tract generation based both on the position of the fiber tracts, as well the anisotropy values along the path. The results demonstrate that the GTRACT algorithm is less sensitive to image noise and more capable of handling areas of complex fiber crossing, compared to conventional streamline methods.

Algorithms↗

PubMed2004

Venezuelan kindreds reveal that genetic and environmental factors modulate Huntington's disease age of onset.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by a triplet (CAG) expansion mutation. The length of the triplet repeat is the most important factor in determining age of onset of HD, although substantial variability remains after controlling for repeat length. The Venezuelan HD kindreds encompass 18,149 individuals spanning 10 generations, 15,409 of whom are living. Of the 4,384 immortalized lymphocyte lines collected, 3,989 DNAs were genotyped for their HD alleles, representing a subset of the population at greatest genetic risk. There are 938 heterozygotes, 80 people with variably penetrant alleles, and 18 homozygotes. Analysis of the 83 kindreds that comprise the Venezuelan HD kindreds demonstrates that residual variability in age of onset has both genetic and environmental components. We created a residual age of onset phenotype from a regression analysis of the log of age of onset on repeat length. Familial correlations (correlation +/- SE) were estimated for sibling (0.40 +/- 0.09), parent-offspring (0.10 +/- 0.11), avuncular (0.07 +/- 0.11), and cousin (0.15 +/- 0.10) pairs, suggesting a familial origin for the residual variance in onset. By using a variance-components approach with all available familial relationships, the additive genetic heritability of this residual age of onset trait is 38%. A model, including shared sibling environmental effects, estimated the components of additive genetic (0.37), shared environment (0.22), and nonshared environment (0.41) variances, confirming that approximately 40% of the variance remaining in onset age is attributable to genes other than the HD gene and 60% is environmental.

Adolescent↗