Nike T Beaubier

Publications (2)7.19 Total impact

• Article: Hematogones are markedly reduced in pediatric acquired aplastic anemia: multiparametric flow cytometric analysis.

  Deborah W Sevilla, Foxwell N Emmons, Adriana I Colovai, Nike T Beaubier, Courtney Baker, Monica Bhatia, Govind Bhagat, Bachir Alobeid
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  ABSTRACT: Acquired aplastic anemia (AA) and myelodysplastic syndromes (MDS) are bone marrow (BM) failure syndromes with overlapping clinical features, and at least a subset appears to share common pathophysiologic mechanisms. Recent studies of MDS have shown down-regulation of genes involved in B-cell development and decreased B-cell precursors (hematogones). We explored the possibility that AA, similar to MDS, might also be associated with defects in development of lymphoid cells, especially B-cells, by using flow cytometry to assess the presence of hematogones and mature lymphocytes in BM samples from 25 children with AA and 41 age-matched controls. We observed that the percentage of total and early (stage I) hematogones were significantly decreased in AA compared to controls, and they returned to normal numbers after hematopoietic stem-cell transplant. This demonstrates early B-cell lineage involvement in AA, similar to recent findings in MDS. Our findings suggest dysfunction of an early multilineage progenitor in the pathogenesis of AA.
  Leukemia & lymphoma 09/2009; 50(12):1951-7. · 2.40 Impact Factor
• Article: Expression of PAX8 in normal and neoplastic renal tissues: an immunohistochemical study

  Guo-Xia Tong, Woojin M Yu, Nike T Beaubier, Erin M Weeden, Diane Hamele-Bena, Mahesh M Mansukhani, Kathleen M O'Toole
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  ABSTRACT: Cell-lineage-specific transcription factors are a group of regulatory proteins expressed in embryonic, differentiated, or neoplastic cells of the same lineage and represent a valuable repertoire of tissue-specific markers for the diagnosis of human tumors. Together with PAX2, PAX8 is a nephric-lineage transcription factor and is required for the establishment of renal-lineage cells and the formation of the kidney. In contrast to PAX2, little is known about the expression of PAX8 in adult kidney and renal tumors. In this study, we used immunohistochemistry to investigate the expression of PAX8 in adult human kidney and renal epithelial tumors. We report here that PAX8 was detected in renal epithelial cells in all segments of renal tubules from the proximal tubules to the renal papillae and in the parietal cells of Bowman's capsule in the adult kidney. PAX8 was also present in 98% of clear cell renal cell carcinomas (RCCs), 90% of papillary RCCs, and 95% of oncocytomas, similar to PAX2. In addition, PAX8 was found in 82% of chromophobe RCCs, 71% of sarcomatoid components of RCCs, and 100% (2/2) of renal medullary carcinomas. Overall, PAX8 was detected in 85% of metastatic renal tumors. Interestingly, expression of PAX8 was noted in some urothelial cells in the renal pelvis and ureters and ~23% of urothelial carcinomas of the renal pelvis, but not in the urothelium or urothelial carcinomas of the urinary bladder; this probably underlines the different embryonic origins of urothelial cells in the upper and lower urinary tracts. As shown in this study, PAX8 is widely expressed in normal and neoplastic renal tissues. PAX8 may be a useful additional marker for renal epithelial tumors; however, its specificity and sensitivity await further investigation.Keywords: PAX8, renal epithelial tumors, urothelial carcinoma, immunohistochemistry
  Modern Pathology 06/2009; 22(9):1218-1227. · 4.79 Impact Factor