Medical Genetics Commons^™

The Role Of Methyl Cpg Binding Domain Protein 2 (Mbd2) In The Regulation Of Embryonic And Fetal Β-Type Globin Genes, Merlin Nithya Gnanapragasam

Theses and Dissertations

The reexpression of the fetal γ-globin gene in adult erythrocytes is of therapeutic interest due to its ameliorating effects in β-hemoglobinopathies. We recently showed that Methyl CpG Binding Domain Protein2 (MBD2) contributes to the silencing of the chicken embryonic ρ-globin and human fetal γ-globin genes. We further biochemically characterized an erythroid MeCP1 complex that is recruited by MBD2 to mediate the silencing of these genes. These observations suggest that the disruption of the MeCP1 complex could augment the expression of the fetal/embryonic globin genes. In the studies presented in chapter 2, we have pursued a structural and biophysical analysis of …

Large Scale Analysis Of Positional Effects Of Single-Base Mismatches On Microarray Gene Expression Data, Fenghai Duan, Mark A. Pauley, Eliot R. Spindel, Li Zhang, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Affymetrix GeneChips utilize 25-mer oligonucleotides probes linked to a silica surface to detect targets in solution. Mismatches due to single nucleotide polymorphisms (SNPs) can affect the hybridization between probes and targets. Previous research has indicated that binding between probes and targets strongly depends on the positions of these mismatches. However, there has been substantial variability in the effect of mismatch type across studies.

METHODS: By taking advantage of naturally occurring mismatches between rhesus macaque transcripts and human probes from the Affymetrix U133 Plus 2 GeneChip, we collected the largest 25-mer probes dataset with single-base mismatches at each of the …

Differential Genome-Wide Array–Based Methylation Profiles In Prognostic Subsets Of Chronic Lymphocytic Leukemia, Meena Kanduri, Nicola Cahill, Hanna Göransson, Camilla Enström, Fergus Ryan, Anders Isaksson, Richard Rosenquist

Articles

Global hypomethylation and regional hypermethylation are well-known epigenetic features of cancer; however, in chronic lymphocytic leukemia (CLL), studies on genome-wide epigenetic modifications are limited. Here, we analyzed the global methylation profiles in CLL, by applying high-resolution methylation microarrays (27 578 CpG sites) to 23 CLL samples, belonging to the immunoglobulin heavy-chain variable (IGHV) mutated (favorable) and IGHV unmutated/IGHV3-21 (poor-prognostic) subsets. Overall, results demonstrated significant differences in methylation patterns between these subgroups. Specifically, in IGHV unmutated CLL, we identified methylation of 7 known or candidate tumor suppressor genes (eg, VHL, ABI3, and IGSF4) as well as 8 unmethylated genes involved in …

Prospects And Pits On The Path Of Biomimetics: The Case Of Tooth Enamel, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents a discourse on challenges in understanding and imitating the process of amelogenesis in vitro on the molecular scale. In light of the analysis of imitation of the growth of dental enamel, it also impends on the prospects and potential drawbacks of the biomimetic approach in general. As the formation of enamel proceeds with the protein matrix guiding the crystal growth, while at the same time conducting its own degradation and removal, it is argued that three aspects of amelogenesis need to be induced in parallel: a) crystal growth; b) protein assembly; c) proteolytic degradation. A particular emphasis …

Chemosensitization Of Cancer Cells By Sirna Using Targeted Nanogel Delivery, Erin B. Dickerson, William H. Blackburn, Michael H. Smith, Laura B. Kapa, L. Andrew Lyon, John F. Mcdonald

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Chemoresistance is a major obstacle in cancer treatment. Targeted therapies that enhance cancer cell sensitivity to chemotherapeutic agents have the potential to increase drug efficacy while reducing toxic effects on untargeted cells. Targeted cancer therapy by RNA interference (RNAi) is a relatively new approach that can be used to reversibly silence genes in vivo by selectively targeting genes such as the epidermal growth factor receptor (EGFR), which has been shown to increase the sensitivity of cancer cells to taxane chemotherapy. However, delivery represents the main hurdle for the broad development of RNAi therapeutics.

Methods: We report here …

Definitions Of The Phenotypic Manifestations Of Sickle Cell Disease., Samir K Ballas, Susan Lieff, Lennette J Benjamin, Carlton D Dampier, Matthew M Heeney, Carolyn Hoppe, Cage S Johnson, Zora R Rogers, Kim Smith-Whitley, Winfred C Wang, Marilyn J Telen

Department of Medicine Faculty Papers

Sickle cell disease (SCD) is a pleiotropic genetic disorder of hemoglobin that has profound multiorgan effects. The low prevalence of SCD ( approximately 100,000/US) has limited progress in clinical, basic, and translational research. Lack of a large, readily accessible population for clinical studies has contributed to the absence of standard definitions and diagnostic criteria for the numerous complications of SCD and inadequate understanding of SCD pathophysiology. In 2005, the Comprehensive Sickle Cell Centers initiated a project to establish consensus definitions of the most frequently occurring complications. A group of clinicians and scientists with extensive expertise in research and treatment of …

Early Detection Of Response To Hydroxyurea Therapy In Patients With Sickle Cell Anemia., Samir K. Ballas, William F. Mccarthy, Nan Guo, Carlo Brugnara, Gail Kling, Robert L. Bauserman, Myron A. Waclawiw

Department of Medicine Faculty Papers

Red blood cells (RBC) and reticulocyte parameters were determined on peripheral blood from a subset of patients enrolled in the multicenter study of hydroxyuea (HU) in sickle cell anemia. Multiple blood samples were obtained every 2 weeks. Cellular indices were measured by flow cytometry. Generalized linear models were used to determine the relationship between the longitudinal trajectories of RBC and reticulocyte indices and HU usage. There was a significant relationship between HU usage and most of the RBC and reticulocyte indices. Hydroxyurea produced higher value trajectories than those generated by placebo usage for the hemoglobin (Hb) content of both the …

Selection Of Optimal Reference Genes For Normalization In Quantitative Rt-Pcr., Inna Chervoneva, Yanyan Li, Stephanie Schulz, Sean Croker, Chantell Wilson, Scott A Waldman, Terry Hyslop

Department of Pharmacology and Experimental Therapeutics Faculty Papers

BACKGROUND: Normalization in real-time qRT-PCR is necessary to compensate for experimental variation. A popular normalization strategy employs reference gene(s), which may introduce additional variability into normalized expression levels due to innate variation (between tissues, individuals, etc). To minimize this innate variability, multiple reference genes are used. Current methods of selecting reference genes make an assumption of independence in their innate variation. This assumption is not always justified, which may lead to selecting a suboptimal set of reference genes. RESULTS: We propose a robust approach for selecting optimal subset(s) of reference genes with the smallest variance of the corresponding normalizing factors. …

Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets With Alopecia Resulting From A Novel Missense Mutation In The Dna-Binding Domain Of The Vitamin D Receptor., Peter J. Malloy, Jining Wang, Tarak Srivastava, David Feldman

Manuscripts, Articles, Book Chapters and Other Papers

The rare genetic recessive disease, hereditary vitamin D resistant rickets (HVDRR), is caused by mutations in the vitamin D receptor (VDR) that result in resistance to the active hormone 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3) or calcitriol). In this study, we examined the VDR from a young boy with clinical features of HVDRR including severe rickets, hypocalcemia, hypophosphatemia and partial alopecia. The pattern of alopecia was very unusual with areas of total baldness, adjacent to normal hair and regions of scant hair. The child failed to improve on oral calcium and vitamin D therapy but his abnormal chemistries and his bone X-rays normalized …

Variable Number Of Tandem Repeat Polymorphisms (Vntrs) In The Acan Gene Associated With Pectus Excavatum, Michael W. Stacey, Serina Neumann, Ashley Dooley, Kara Segna, Robert Kelly, Donald Nuss, Anne Kuhn, Michael Goretsky, Annie Fecteau, Aimee Pastor, Virginia Proud

Bioelectrics Publications

No abstract provided.

Semiparametric Analysis Of Recurrent Events: Artificial Censoring, Truncation, Pairwise Estimation And Inference, Debashis Ghosh

Debashis Ghosh

The analysis of recurrent failure time data from longitudinal studies can be complicated by the presence of dependent censoring. There has been a substantive literature that has developed based on an artificial censoring device. We explore in this article the connection between this class of methods with truncated data structures. In addition, a new procedure is developed for estimation and inference in a joint model for recurrent events and dependent censoring. Estimation proceeds using a mixed U-statistic based estimating function approach. New resampling-based methods for variance estimation and model checking are also described. The methods are illustrated by application to …