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Biomedical subjects

L Hsu

Publications and source records attributed to L Hsu.

186 records · Page 11Linked to original sources
PubMedDate not supplied

A tissue culture model for studying ethanol toxicity on embryonic heart cells.

A tissue system in which fibroblasts and myocytes from chick embryonic hearts were separately maintained was used to study the toxicity of ethanol. To reproduce the teratogenic effects of acute, high concentrations of ethanol typical of "binge" drinking, an open tissue culture system was employed. With open cultures, the cells were initially exposed to peak alcohol levels for approximately 6 hr and were exposed to decreasing concentrations of ethanol for the remainder of each 24 hr period. After the first day of ethanol exposure, there was substantial cell loss in both fibroblast and myocyte cultures. Alcohol-induced cell loss was dose-dependent. Despite decreased cell density after the first day of ethanol exposure, the surviving cells differentiated into monolayers of fibroblasts or beating cardiac muscle fibers. However, both ethanol-exposed fibroblasts and myocytes appeared atrophic, that is, smaller and shrunken. Electrophoretic analysis or these ethanol-exposed fibroblast and myocyte cultures revealed specific reduction in the cellular contents of alpha-actinin, myosin, and actin. These decreases in cytoskeletal proteins may be responsible for the morphological abnormalities noted in these cells.

Animals↗
PubMedDate not supplied

The effect of prior trauma exposure on the development of PTSD following spinal cord injury.

Posttraumatic stress disorder (PTSD) occurs in only a subset of individuals who sustain traumatic spinal cord injuries (SCIs). Several previous studies have examined the effects of additive trauma on the development of PTSD and found that a history of prior trauma increases the risk for later development of PTSD. The present study examines additive trauma by investigating the effects of previous combat exposure on the development of PTSD following spinal cord injury. Significant differences in prevalence rates for current PTSD were found for the comparisons of war theater (both combat and noncombat) versus non-war theater veterans but not for the comparison between combat and noncombat war theater veterans. Moreover, for all the comparisons, no significant differences were found in lifetime PTSD diagnoses. This implies that veterans with SCI who served in a war zone have increased difficulty recovering from their PTSD following a spinal cord injury than do non-war theater veterans.

Analysis of Variance↗
PubMedDate not supplied

Neurocognitive functioning and magnetic resonance imaging in children with sickle cell disease.

OBJECTIVE: To examine neurocognitive functioning in children classified with overt cerebral vascular accidents (CVAs), silent infarcts, or without central nervous system (CNS) pathology on magnetic resonance imaging. METHODS: Participants were 63 children and adolescents with sickle cell disease (SCD). RESULTS: Children with overt CVAs and silent infarcts differed from their peers without CNS pathology on measures of attention and executive functioning. CONCLUSIONS: We consider these deficits the result of the high frequency of frontal lobe deficits incurred by children with SCD. Recommendations include the use of tests designed to measure attention and executive functioning as a way of screening children with SCD for possible CNS pathology. We also suggest that future research examine the mechanism underlying frontal lobe involvement for individuals with SCD.

Adolescent↗
PubMedDate not supplied

Social information processing and magnetic resonance imaging in children with sickle cell disease.

OBJECTIVE: To examine social information processing, social skills, and adjustment difficulties in children with sickle cell disease (SCD) as rated by caregivers, teachers, and the children themselves. Children were classified in two groups: cerebral vascular accidents (CVA) (n = 21) or without central nervous system (CNS) pathology (n = 20) on magnetic resonance imaging (MRI). Both groups had HbSS SCD. We compared these two groups and a third group of 11 children who had a milder type of SCD (HbSC). METHODS: Participants referred for evaluation of learning and behavior problems were administered MRIs to ascertain the presence of pathology and a series of measures designed to assess nonverbal emotional decoding abilities and ratings of social emotional functioning. RESULTS: Children with CVA displayed more errors on tasks of facial and vocal emotional decoding than did comparison controls without CVA. CONCLUSIONS: Acquired neurological impairments in children with SCD seemed to be associated with difficulties in the decoding of emotions of other children and adults. We recommend that future research integrate neuropsychological and psychosocial research programs for pediatric chronic illness groups.

Adaptation, Psychological↗
PubMedDate not supplied

A note on a conditional-likelihood approach for family-based association studies of candidate genes.

The family-based association study design is a variation of the case-control study design, where unaffected family members instead of unrelated subjects are sampled as controls. This variation is useful in assessing the effects of candidate genes on disease, because it avoids false associations caused by admixture of populations. A complication of this design is that because of an inherited genotypic correlation among family members, the genotypic distributions between cases and relative controls may be distorted by the ascertainment criteria of families, which could involve not only cases and relative controls, but also other relatives. Analyzing such data naively may lead to biased estimates of relative risk. In this note, we will discuss the consistency of a conditional-likelihood approach. We show analytically that maximum conditional-likelihood estimators are consistent for the true relative risks, if genotypes for family members are exchangeable under the sampling process, for example, sibling clusters. Besides being straightforward conceptually and computationally, this approach is robust to ascertainment bias and naturally accommodates genetic heterogeneity across families.

Algorithms↗