Biomedical subjects

Aaron LeValley

Publications and source records attributed to Aaron LeValley.

3 recordsLinked to original sources

PubMed2006

AIDS and non-AIDS diffuse large B-cell lymphomas express different antigen profiles.

Based on gene expression profiling, diffuse large B-cell lymphomas arising in immunocompetent patients can be divided into germinal center and activated B-cell types. Since little is known about acquired immunodeficiency syndrome associated diffuse large B-cell lymphomas, we tested whether the protein expression of germinal center and activated B-cell markers differed between acquired immunodeficiency syndrome (AIDS) vs non-AIDS diffuse large B-cell lymphomas. We immunohistochemically stained tissue microarrays of 39 de novo diffuse large B-cell lymphomas: 12 AIDS associated and 27 non-AIDS, with germinal center (BCL6, CD10, CyclinH) and activated B-cell markers (MUM1, CD138, PAK1, CD44, BCL2). We scored each case for percent positive cells (0-19%=0; 20-49%=1; 50-100%=2). The activated B-cell and germinal center summation scores of each case were used as (x, y) coordinate data points to construct two-dimensional contour-frequency plots. The contour plot of non-AIDS diffuse large B-cell lymphomas showed two distinct clusters: a cluster with a high germinal center phenotype (cluster 1) and a cluster with a high activated B-cell phenotype (cluster 3). In contrast, the AIDS-related diffuse large B-cell lymphomas formed a single aggregate (cluster 2) (P=0.02, Fisher exact test). When the contour plots of the AIDS-related and the non-AIDS cases were superimposed, cluster 2 of the AIDS cases expressed an intermediate germinal center/activated B-cell phenotype compared to clusters 1 and 3 of the non-AIDS diffuse large B-cell lymphomas. Our results confirm that non-AIDS diffuse large B-cell lymphomas segregate into two groups with either germinal center or activated B-cell phenotype. We report the new finding that the AIDS status of the patient predicts the immunophenotype of the diffuse large B-cell lymphomas.

Adult↗

PubMed2006

Epidemiology of gait disorders in community-residing older adults.

OBJECTIVES: To study the epidemiology of gait disorders in community-residing older adults and their association with death and institutionalization. DESIGN: Community-based cohort study. SETTING: Bronx County and the research center at Albert Einstein College of Medicine. PARTICIPANTS: The Einstein Aging study recruited 488 adults aged 70 to 99 between 1999 and 2001. At entry and during annual visits over 5 years, subjects received clinical evaluations to determine presence of neurological or nonneurological gait abnormalities. MEASUREMENTS: Prevalence and incidence of gait disorders based on clinical evaluations and time to institutionalization and death. RESULTS: Of 468 subjects (95.9%) with baseline gait evaluations, 168 had abnormal gaits: 70 neurological, 81 nonneurological, and 17 both. Prevalence of abnormal gait was 35.0% (95% confidence interval (CI) = 28.6-42.1). Incidence of abnormal gait was 168.6 per 1,000 person-years (95% CI = 117.4-242.0) and increased with age. Men had a higher incidence of neurological gait abnormalities, whereas women had a higher incidence of nonneurological gaits. Abnormal gaits were associated with greater risk of institutionalization and death (hazard ratio (HR) = 2.2, 95% CI =1.5-3.2). The risk was strongly related to severity of impairment; subjects with moderate to severe gait abnormalities (HR = 3.2, 95% CI = 1.9-5.2) were at higher risk than those with mild gait abnormalities (HR = 1.8, 95% CI = 1.0-2.8). CONCLUSION: The incidence and prevalence of gait disorders are high in community-residing older adults and are associated with greater risk of institutionalization and death.

Aged↗

PubMed2005

Germinal center and activated b-cell profiles separate Burkitt lymphoma and diffuse large B-cell lymphoma in AIDS and non-AIDS cases.

Morphologic features of Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) overlap. No single phenotypic marker or molecular abnormality is pathognomonic. We tested a panel of 8 germinal center (GC) and activated B-cell (ABC) markers for their ability to separate BL and DLBCL. We diagnosed 16 BL and 39 DLBCL cases from 21 patients with AIDS and 34 without AIDS based on traditional morphologic criteria, Ki-67 proliferative index, and c-myc rearrangement (fluorescence in situ hybridization). After immunohistochemically staining tissue microarrays of BL and DLBCL for markers of GC (bcl-6, CD10, cyclin H) and ABC (MUM1, CD138, PAK1, CD44, bcl-2), we scored each case for the percentage of positive cells. Hierarchical clustering yielded 2 major clusters significantly associated with morphologic diagnosis (P < .001). For comparison, we plotted the sum of the GC scores and ABC scores for each case as x and y data points. This revealed a high-GC/low-ABC group and a low-GC/high-ABC group that were associated significantly with morphologic diagnosis (P < .001). Protein expression of multiple GC and ABC markers can separate BL and DLBCL.

Adolescent↗