Biomedical subjects

Allison A King

Publications and source records attributed to Allison A King.

3 recordsLinked to original sources

PubMed2026

Proteomic profiling identifies systemic drivers of blood-brain barrier injury in sickle cell disease.

Sickle cell disease (SCD) causes brain injury and cognitive disability. Systemic inflammation and endothelial injury are central to SCD pathophysiology, yet the relationship between systemic drivers of blood-brain barrier (BBB) disruption and brain injury remains understudied. This cross-sectional study assessed whole-brain and regional BBB permeability (Ktrans) using dynamic contrast-enhanced magnetic resonance imaging for 37 adults with SCD in steady state and 37 adults without SCD. Cerebral oxygen extraction fraction (OEF) and white matter mean diffusivity (MD) measured tissue hypoxia and microstructural injury, respectively. The SCD cohort showed elevated Ktrans compared with controls (3.6 × 10-4·min-1 vs 2.58 × 10-4·min-1; 95% confidence interval [CI] median difference, 0.36 × 10-4·min-1 to 1.30 × 10-4·min-1; P< .001), indicating BBB disruption. In SCD, white matter Ktrans was associated with MD (β, 6.25 [95% CI, 1.72-10.77]; P = .008), independent of OEF (β, 0.22 [95% CI, 0.09-0.35]), and silent cerebral infarcts (β, 0.01 [95% CI, 0.00-0.02]). The interaction (P = .037) between Ktrans and OEF on MD suggested a combined, deleterious effect of BBB disruption and hypoxia on microstructural injury. High-throughput plasma proteomics followed by differential expression analysis, and weighted gene correlation network analysis in a subset of 61 participants revealed that 79 proteins associated with BBB permeability belonged to iron homeostasis, response to hypoxia, immune dysregulation, extracellular matrix degradation, lipoprotein homeostasis, and arginine-proline metabolism pathways. All pathways were independently associated with microstructural injury. BBB permeability was a mediator of brain injury for all pathways except extracellular matrix degradation. Targeting specific systemic pathways to protect the BBB may represent a therapeutic approach to preserve brain health in SCD.

Humans↗

PubMed2006

Low frequency of telomerase RNA mutations among children with aplastic anemia or myelodysplastic syndrome.

Mutations in TERC, the RNA component of telomerase, result in autosomal dominant dyskeratosis congenita (DC), a rare bone marrow failure syndrome. TERC mutations have been detected in a subset of patients previously diagnosed with aplastic anemia and myelodysplastic syndrome (MDS), and these TERC mutations are clinically relevant as patients with DC respond poorly to conventional therapies. We aimed to determine the frequency of TERC mutations in pediatric patients with aplastic anemia and MDS who required a hematopoietic stem cell transplant. We obtained 284 blood samples from the National Donor Marrow Program Research Sample Repository from children and adolescents with bone marrow failure who underwent an unrelated stem cell transplant. We screened these samples for mutations in the TERC gene using direct DNA sequencing. We found 2 patients with sequence alterations in TERC. We identified a 2 base pair deletion (-240delCT) in a 4-year-old child with MDS and a single nucleotide alteration (-99-->CG) in a 1-year-old child with juvenile myelomonocytic leukemia. Screening for TERC gene mutations is unlikely to diagnose occult DC in children with severe bone marrow failure who require a hematopoietic stem cell transplant.

Adolescent↗

PubMed2005

An education program to increase teacher knowledge about sickle cell disease.

This program evaluated the effectiveness of a sickle cell disease (SCD) education program for teachers of students with SCD in their classroom. Teachers with students in a remediation program for students participated in an educational program consisting of four domains: Inheritance and Prevalence, Common Complications, Strokes, and Individual Education Plans (IEP). A 30- to 45-minute presentation was given with a pretest and posttest. Eighty-one teachers who taught grades K-12 completed the program. Most teachers understood the complications of fever and pain, risks of strokes occurring at any age, and the purpose of IEPs. Overall the rate of correct answers increased from 72.5% to 83.1%, p = 0.0001. Teachers improved their understanding of heredity (32% vs. 66%, p = 0.0001), prevalence (81% vs. 94%, p = 0.039), silent stroke diagnosis (21% vs. 80%, p = 0.0001) and overt stroke therapy (40% vs. 75%, p = 0.0001). No significant impact on teacher knowledge occurred for the contents of IEPs (80% vs. 87%, p = 0.227). Teachers of students with SCD increased knowledge about SCD following the program.

Child↗