W.G. Kearns

Aneuploidy frequencies in semen fractions from ten oligoasthenoteratozoospermic patients donating sperm for intracytoplasmic sperm injection

OBJECTIVE To determine aneuploidy frequencies in pellet and swim-up semen fractions from 10 infertile men with severe oligoasthenoteratozoospermia (OAT) who were donating sperm for intracytoplasmic sperm injection and to determine whether the swim-up isolation method would successfully separate aneuploid from haploid sperm. DESIGN Prospective study. SETTING Infertility clinic and molecular genetics laboratory. PATIENT(S) Ten patients with severe OAT. INTERVENTION(S) Cytogenetic analyses by fluorescence in situ hybridization to determine aneuploidy frequencies for chromosomes 1, 13, 18, 21, X, and Y in sperm from swim-up and pellet fractions. MAIN OUTCOME MEASURE(S) Gametic aneuploidy was scored in sperm fractions separated by the swim-up technique and clinical results after intracytoplasmic sperm injection were tabulated. RESULT(S) In all cases, chromosome aneuploidy levels in patients were significantly greater than in controls. The type and percentage of aneuploid sperm for all patients with OAT found in both swim-up and pellet fractions were not different, with the exception of diploid sperm, which remained in the pellet fraction. After ET, 2 (20%) of 10 couples achieved successful pregnancies. CONCLUSION(S) The data show significantly higher rates of diploidy, autosomal disomy and nullisomy, sex chromosome disomy and nullisomy, and total aneuploidy in sperm from all separated fractions obtained from all patients with OAT versus controls. This patient population with OAT may be at increased risk of producing aneuploid offspring.

Absence of donor-derived keratinocyte stem cells in skin tissues cultured from patients after mobilized peripheral blood hematopoietic stem cell transplantation

OBJECTIVE Recent studies suggest that primitive bone marrow-derived cells contribute to regeneration of many tissues, including muscle, endothelium, myocardium, neural tissues, liver, and skin. Conversely, primitive cells resident in muscle and other tissues have been reported to reconstitute hematopoiesis. We investigated the contribution of cells with a primitive hematopoietic phenotype to human epidermal skin formation in recipients of allogeneic mobilized peripheral blood hematopoietic stem cell (HSC) transplantation. PATIENTS AND METHODS Our study population included female patients who had received granulocyte colony-stimulating factor mobilized peripheral blood HSC transplants from male donors for a variety of benign and malignant hematologic disorders at least 6 months before study entry, with a history of skin graft-vs-host disease. Epidermal skin cells (keratinocytes) obtained from punch biopsies of the skin were cultured under conditions specific for growth and expansion of homogenous populations of keratinocytes from keratinocyte stem cells. After multiple passages, DNA was extracted from cultured cells and evaluated by two different polymerase chain reaction (PCR) method for detection of Y chromosome specific sequences. RESULTS Neither sensitive PCR-based technique revealed the presence of male donor-derived keratinocyte stem cells in keratinocytes cultured from skin biopsies of female allogeneic transplantation recipients. CONCLUSIONS We could not confirm the contribution of donor mobilized peripheral blood hematopoietic stem cells to keratinocyte stem cell populations after HSC transplantation. These results cannot explain the presence of donor-derived cells with keratinocyte phenotypic markers in tissue sections of HSC transplant recipients.

Centrosome amplification and aneuploidy in bone marrow failure patients.

Patients with bone marrow failure are at risk for development of hematopoietic progenitor clones with abnormal numbers of chromosomes (aneuploidy) and leukemia. Numerical centrosome abnormalities or mutations in genes associated with the mitotic spindle checkpoint (BUB1 and MAD2) are two important mechanisms that can induce abnormal mitosis resulting in aneuploid daughter cells. To assess the role of these mechanisms, we used fluorescence in situ hybridization techniques to determine aneuploidy and centrosome copy number and PCR‐SSCP to identify gene mutations of BUB1 and MAD2 in marrow cells of 25 patients. No mutations were found in BUB1 or MAD2 genes. However, we found that cells with more than two centrosomes exhibited aneuploidy for three or more chromosomes. We conclude that centrosome amplification may be associated with the development of a clonal population of potentially preleukemic aneuploid cells.

Nuclear receptor co‐repressor gene localizes to 17p11.2, a frequently deleted band in malignant disorders

The t(8;21) between the AML1 and ETO genes is a commonly seen genetic alteration in acute myeloid leukemia. Recently, we reported that the fusion partner ETO binds to the human nuclear receptor co‐repressor (NCOR), a member of the NCOR/SIN3/histone deacetylase complex. This complex mediates transcriptional repression as a result of chromatin remodeling. Here, we used a combination of fluorescence in situ hybridization and hybrid panels to localize the human NCOR gene (NCOR) to chromosome band 17p11.2. The position of human NCOR on 17p11 raises the possibility of deranged transcriptional regulation in malignant disorders associated with deletions of 17p. Genes Chromosomes Cancer 25:191–193, 1999. Published 1999 Wiley‐Liss, Inc.

Physical mapping of the nail patella syndrome interval at 9q34: ordering of STSs and ESTs.

)Center for Medical Genetics, Johns Hopkins University, 600 NorthWolfe Street, Blalock 1012G, Baltimore, MD 21287-4922, USAe-mail: imcintos@welchlink.welch.jhu.edu, Tel.: +1 410 955 7948,Fax: +1 410 614 2522H. RootGenome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USAK. M. Scott · J. E. RichardsDepartment of Ophthamology, University of Michigan Ann Arbor, MI 48105, USAM. K. McCormick