Medicine and Health Sciences Commons^™

Pcr-Based Assay Using Occult Blood Detection Cards For Detection Of Diarrheagenic Escherichia Coli In Specimens From Us Travelers To Mexico With Acute Diarrhea, Kevin A Grimes, Jamal A Mohamed, Herbert L Dupont, Ranjit S Padda, Zhi-Dong Jiang, Jose Flores, Jaime Belkind-Gerson, Francisco G Martinez-Sandoval, Pablo C Okhuysen

Faculty, Staff and Student Publications

Large field studies of travelers' diarrhea for multiple destinations are limited by the need to perform stool cultures on site in a timely manner. A method for the collection, transport, and storage of fecal specimens that does not require immediate processing and refrigeration and that is stable for months would be advantageous. This study was designed to determine if enterotoxigenic Escherichia coli (ETEC) and enteroaggregative E. coli (EAEC) DNA could be identified from cards that were processed for the evaluation of fecal occult blood. U.S. students traveling to Mexico during 2005 to 2007 were monitored for the occurrence of diarrheal …

The Temporal Relationship Between The Coronavirus Disease 2019 (Covid-19) Pandemic And Preterm Birth, Harold E Bedell, Mahalakshmi Ramamurthy, Saumil S Patel, Shobana Subramaniam, Lan-Phuong Vu-Yu, Jianliang Tong

Faculty, Staff and Student Publications

Despite rapid to-and-fro motion of the retinal image that results from their incessant involuntary eye movements, persons with infantile nystagmus (IN) rarely report the perception of motion smear. We performed two experiments to determine if the reduction of perceived motion smear in persons with IN is associated with an increase in the speed of the temporal impulse response. In Experiment 1, increment thresholds were determined for pairs of successively presented flashes of a long horizontal line, presented on a 65-cd/m2 background field. The stimulus-onset asynchrony (SOA) between the first and second flash varied from 5.9 to 234 ms. In experiment …

Water-Soluble Fullerene (C60) Derivatives As Nonviral Gene-Delivery Vectors, Balaji Sitharaman, Tatiana Y Zakharian, Anita Saraf, Preeti Misra, Jared Ashcroft, Su Pan, Quynh P Pham, Antonios G Mikos, Lon J Wilson, David A Engler

Faculty, Staff and Student Publications

A new class of water-soluble C60 transfecting agents has been prepared using Hirsch-Bingel chemistry and assessed for their ability to act as gene-delivery vectors in vitro. In an effort to elucidate the relationship between the hydrophobicity of the fullerene core, the hydrophilicity of the water-solubilizing groups, and the overall charge state of the C60 vectors in gene delivery and expression, several different C60 derivatives were synthesized to yield either positively charged, negatively charged, or neutral chemical functionalities under physiological conditions. These fullerene derivatives were then tested for their ability to transfect cells grown in culture with DNA carrying the green …

Synaptotagmin-2 Controls Regulated Exocytosis But Not Other Secretory Responses Of Mast Cells*, Qun-Fang Wan, Alejandro Vila, Zhen-Yu Zhou, Ruth Heidelberger

Faculty, Staff and Student Publications

To better understand synaptic signaling at the mammalian rod bipolar cell terminal and pave the way for applying genetic approaches to the study of visual information processing in the mammalian retina, synaptic vesicle dynamics and intraterminal calcium were monitored in terminals of acutely isolated mouse rod bipolar cells and the number of ribbon-style active zones quantified. We identified a releasable pool, corresponding to a maximum of 7 s. The presence of a smaller, rapidly releasing pool and a small, fast component of refilling was also suggested. Following calcium channel closure, membrane surface area was restored to baseline with a time …

Obesity And Cardiac Metabolism In Women, Heinrich Taegtmeyer, Mohamed F Algahim

Faculty, Staff and Student Publications

No abstract provided.

Generalized Fuzzy Clustering For Segmentation Of Multi-Spectral Magnetic Resonance Images, Renjie He, Sushmita Datta, Balasrinivasa Rao Sajja, Ponnada A Narayana

Faculty, Staff and Student Publications

An integrated approach for multi-spectral segmentation of MR images is presented. This method is based on the fuzzy c-means (FCM) and includes bias field correction and contextual constraints over spatial intensity distribution and accounts for the non-spherical cluster's shape in the feature space. The bias field is modeled as a linear combination of smooth polynomial basis functions for fast computation in the clustering iterations. Regularization terms for the neighborhood continuity of intensity are added into the FCM cost functions. To reduce the computational complexity, the contextual regularizations are separated from the clustering iterations. Since the feature space is not isotropic, …

Brain Fiber Tract Plasticity In Experimental Spinal Cord Injury: Diffusion Tensor Imaging, Jaivijay Ramu, Juan Herrera, Raymond Grill, Tobias Bockhorst, Ponnada Narayana

Faculty, Staff and Student Publications

Diffusion tensor imaging (DTI) and immunohistochemistry were performed in spinal cord injured rats to understand the basis for activation of multiple regions in the brain observed in functional magnetic resonance imaging (fMRI) studies. The measured fractional anisotropy (FA), a scalar measure of diffusion anisotropy, along the region encompassing corticospinal tracts (CST) indicates significant differences between control and injured groups in the 3 to 4 mm area posterior to bregma that correspond to internal capsule and cerebral peduncle. Additionally, DTI-based tractography in injured animals showed increased number of fibers that extend towards the cortex terminating in the regions that were activated …

Role Played By Serum, A Biological Cue, In The Adherence Of Enterococcus Faecalis To Extracellular Matrix Proteins, Collagen, Fibrinogen, And Fibronectin, Sreedhar R Nallapareddy, Barbara E Murray

Faculty, Staff and Student Publications

BACKGROUND: Most previous studies have found that Enterococcus faecalis isolates do not show significant adherence to fibronectin and fibrinogen.

METHODS: The influence of various conditions on E. faecalis adherence to extracellular matrix (ECM) proteins was evaluated using a radiolabeled-cell adherence assay.

RESULTS: Among the conditions studied, growth in 40% horse serum (a biological cue with potential clinical relevance) elicited adherence of all 46 E. faecalis strains tested to fibronectin and fibrinogen but not to elastin; adherence levels were independent of strain source, and adherence was eliminated by treating cells with trypsin. As previously reported, serum also elicited adherence to collagen. …

Skeletal Abnormalities In Mice Lacking Extracellular Matrix Proteins, Thrombospondin-1, Thrombospondin-3, Thrombospondin-5, And Type Ix Collagen, Karen L Posey, Kurt Hankenson, Alka C Veerisetty, Paul Bornstein, Jack Lawler, Jacqueline T Hecht

Faculty, Staff and Student Publications

Thrombospondin-5 (TSP5) is a large extracellular matrix glycoprotein found in musculoskeletal tissues. TSP5 mutations cause two skeletal dysplasias, pseudoachondroplasia and multiple epiphyseal dysplasia; both show a characteristic growth plate phenotype with retention of TSP5, type IX collagen (Col9), and matrillin-3 in the rough endoplasmic reticulum. Whereas most studies focus on defining the disease process, few functional studies have been performed. TSP5 knockout mice have no obvious skeletal abnormalities, suggesting that TSP5 is not essential in the growth plate and/or that other TSPs may compensate. In contrast, Col9 knockout mice have diminished matrillin-3 levels in the extracellular matrix and early-onset osteoarthritis. …

Rtr1 Is The Saccharomyces Cerevisiae Homolog Of A Novel Family Of Rna Polymerase Ii-Binding Proteins, Patrick A Gibney, Thomas Fries, Susanne M Bailer, Kevin A Morano

Faculty, Staff and Student Publications

Cells must rapidly sense and respond to a wide variety of potentially cytotoxic external stressors to survive in a constantly changing environment. In a search for novel genes required for stress tolerance in Saccharomyces cerevisiae, we identified the uncharacterized open reading frame YER139C as a gene required for growth at 37 degrees C in the presence of the heat shock mimetic formamide. YER139C encodes the closest yeast homolog of the human RPAP2 protein, recently identified as a novel RNA polymerase II (RNAPII)-associated factor. Multiple lines of evidence support a role for this gene family in transcription, prompting us to rename …

A Bacterial Cytotoxin Identifies The Rhoa Exchange Factor Net1 As A Key Effector In The Response To Dna Damage, Lina Guerra, Heather S. Carr, Agneta Richter-Dahlfors, Maria G Masucci, Monica Thelestam, Jeffrey A Frost, Teresa Frisan

Faculty, Staff and Student Publications

BACKGROUND: Exposure of adherent cells to DNA damaging agents, such as the bacterial cytolethal distending toxin (CDT) or ionizing radiations (IR), activates the small GTPase RhoA, which promotes the formation of actin stress fibers and delays cell death. The signalling intermediates that regulate RhoA activation and promote cell survival are unknown. PRINCIPAL FINDINGS: We demonstrate that the nuclear RhoA-specific Guanine nucleotide Exchange Factor (GEF) Net1 becomes dephosphorylated at a critical inhibitory site in cells exposed to CDT or IR. Expression of a dominant negative Net1 or Net1 knock down by iRNA prevented RhoA activation, inhibited the formation of stress fibers, …

388 A Structure Of Cytoplasmic Polyhedrosis Virus By Cryo-Electron Microscopy, Xuekui Yu, Lei Jin, Z Hong Zhou

Faculty, Staff and Student Publications

Cytoplasmic polyhedrosis virus (CPV) is unique within the Reoviridae family in having a turreted single-layer capsid contained within polyhedrin inclusion bodies, yet being fully capable of cell entry and endogenous RNA transcription. Biochemical data have shown that the amino-terminal 79 residues of the CPV turret protein (TP) is sufficient to bring CPV or engineered proteins into the polyhedrin matrix for micro-encapsulation. Here we report the three-dimensional structure of CPV at 3.88 A resolution using single-particle cryo-electron microscopy. Our map clearly shows the turns and deep grooves of alpha-helices, the strand separation in beta-sheets, and densities for loops and many bulky …

Rest Maintains Self-Renewal And Pluripotency Of Embryonic Stem Cells, Sanjay K Singh, Mohamedi N Kagalwala, Jan Parker-Thornburg, Henry Adams, Sadhan Majumder

Faculty, Staff and Student Publications

The neuronal repressor REST (RE1-silencing transcription factor; also called NRSF) is expressed at high levels in mouse embryonic stem (ES) cells, but its role in these cells is unclear. Here we show that REST maintains self-renewal and pluripotency in mouse ES cells through suppression of the microRNA miR-21. We found that, as with known self-renewal markers, the level of REST expression is much higher in self-renewing mouse ES cells than in differentiating mouse ES (embryoid body, EB) cells. Heterozygous deletion of Rest (Rest+/-) and its short-interfering-RNA-mediated knockdown in mouse ES cells cause a loss of self-renewal-even when these cells are …

Diviva Is Required For Polar Growth In The Mreb-Lacking Rod-Shaped Actinomycete Corynebacterium Glutamicum, Michal Letek, Efrén Ordóñez, José Vaquera, William Margolin, Klas Flärdh, Luis M Mateos, José A Gil

Faculty, Staff and Student Publications

The actinomycete Corynebacterium glutamicum grows as rod-shaped cells by zonal peptidoglycan synthesis at the cell poles. In this bacterium, experimental depletion of the polar DivIVA protein (DivIVA(Cg)) resulted in the inhibition of polar growth; consequently, these cells exhibited a coccoid morphology. This result demonstrated that DivIVA is required for cell elongation and the acquisition of a rod shape. DivIVA from Streptomyces or Mycobacterium localized to the cell poles of DivIVA(Cg)-depleted C. glutamicum and restored polar peptidoglycan synthesis, in contrast to DivIVA proteins from Bacillus subtilis or Streptococcus pneumoniae, which localized at the septum of C. glutamicum. This confirmed that DivIVAs …

Cd73-Generated Adenosine Restricts Lymphocyte Migration Into Draining Lymph Nodes, Masahide Takedachi, Dongfeng Qu, Yukihiko Ebisuno, Hiroyuki Oohara, Michelle L Joachims, Stephanie T Mcgee, Emiko Maeda, Rodger P Mcever, Toshiyuki Tanaka, Masayuki Miyasaka, Shinya Murakami, Thomas Krahn, Michael R Blackburn, Linda F Thompson

Faculty, Staff and Student Publications

After an inflammatory stimulus, lymphocyte migration into draining lymph nodes increases dramatically to facilitate the encounter of naive T cells with Ag-loaded dendritic cells. In this study, we show that CD73 (ecto-5'-nucleotidase) plays an important role in regulating this process. CD73 produces adenosine from AMP and is expressed on high endothelial venules (HEV) and subsets of lymphocytes. Cd73(-/-) mice have normal sized lymphoid organs in the steady state, but approximately 1.5-fold larger draining lymph nodes and 2.5-fold increased rates of L-selectin-dependent lymphocyte migration from the blood through HEV compared with wild-type mice 24 h after LPS administration. Migration rates of …

Enterococcus Faecalis Pcfc, A Spatially Localized Substrate Receptor For Type Iv Secretion Of The Pcf10 Transfer Intermediate, Yuqing Chen, Xiaolin Zhang, Dawn Manias, Hye-Jeong Yeo, Gary M Dunny, Peter J Christie

Faculty, Staff and Student Publications

Upon sensing of peptide pheromone, Enterococcus faecalis efficiently transfers plasmid pCF10 through a type IV secretion (T4S) system to recipient cells. The PcfF accessory factor and PcfG relaxase initiate transfer by catalyzing strand-specific nicking at the pCF10 origin of transfer sequence (oriT). Here, we present evidence that PcfF and PcfG spatially coordinate docking of the pCF10 transfer intermediate with PcfC, a membrane-bound putative ATPase related to the coupling proteins of gram-negative T4S machines. PcfC and PcfG fractionated with the membrane and PcfF with the cytoplasm, yet all three proteins formed several punctate foci at the peripheries of pheromone-induced cells as …

Intensive Care For Extreme Prematurity--Moving Beyond Gestational Age, Jon E Tyson, Nehal A Parikh, John Langer, Charles Green, Rosemary D Higgins

Faculty, Staff and Student Publications

BACKGROUND: Decisions regarding whether to administer intensive care to extremely premature infants are often based on gestational age alone. However, other factors also affect the prognosis for these patients.

METHODS: We prospectively studied a cohort of 4446 infants born at 22 to 25 weeks' gestation (determined on the basis of the best obstetrical estimate) in the Neonatal Research Network of the National Institute of Child Health and Human Development to relate risk factors assessable at or before birth to the likelihood of survival, survival without profound neurodevelopmental impairment, and survival without neurodevelopmental impairment at a corrected age of 18 to …

Ms211: Letter From John Post To Armin & Karen, Armin Weinberg

Works on Radiation Effects: 1990-2020

This is a letter that accompanied a gift (tube with document inside that was printed by the original Gutenberg printing press) from John Post to Armin. John was a ret. Col. in medical logistics (at the US Dept of State) that helped distribute excess medical and hospital supplies to our AIHA partners in Kazakhstan, Azerbiajan and actually helped with shipment to Gaza as well. Since he lived in DC I invited him to a couple of the non-radiation related Intercultural Cancer Council Biennial Symposia that our Center at BCM coordinated. The page is now at the HRC for viewing. See …

Ly2109761, A Novel Transforming Growth Factor Beta Receptor Type I And Type Ii Dual Inhibitor, As A Therapeutic Approach To Suppressing Pancreatic Cancer Metastasis, Davide Melisi, Satoshi Ishiyama, Guido M Sclabas, Jason B Fleming, Qianghua Xia, Giampaolo Tortora, James L Abbruzzese, Paul J Chiao

Faculty, Staff and Student Publications

Most pancreatic cancer patients present with inoperable disease or develop metastases after surgery. Conventional therapies are usually ineffective in treating metastatic disease. It is evident that novel therapies remain to be developed. Transforming growth factor beta (TGF-beta) plays a key role in cancer metastasis, signaling through the TGF-beta type I/II receptors (TbetaRI/II). We hypothesized that targeting TbetaRI/II kinase activity with the novel inhibitor LY2109761 would suppress pancreatic cancer metastatic processes. The effect of LY2109761 has been evaluated on soft agar growth, migration, invasion using a fibroblast coculture model, and detachment-induced apoptosis (anoikis) by Annexin V flow cytometric analysis. The efficacy …

Drug Metabolism In Human Brain: High Levels Of Cytochrome P4503a43 In Brain And Metabolism Of Anti-Anxiety Drug Alprazolam To Its Active Metabolite, Varsha Agarwal, Reddy P. Kommaddi, Khader Valli, Daniel Ryder, Thomas M. Hyde, Joel E. Kleinman, Henry W. Strobel, Vijayalakshmi Ravindranath

Faculty, Staff and Student Publications

Cytochrome P450 (P450) is a super-family of drug metabolizing enzymes. P450 enzymes have dual function; they can metabolize drugs to pharmacologically inactive metabolites facilitating their excretion or biotransform them to pharmacologically active metabolites which may have longer half-life than the parent drug. The variable pharmacological response to psychoactive drugs typically seen in population groups is often not accountable by considering dissimilarities in hepatic metabolism. Metabolism in brain specific nuclei may play a role in pharmacological modulation of drugs acting on the CNS and help explain some of the diverse response to these drugs seen in patient population. P450 enzymes are …

The Effect Of Dexmedetomidine On The Mini-Cog Score And High-Mobility Group Box 1 Levels In Elderly Patients With Postoperative Neurocognitive Disorders Undergoing Orthopedic Surgery, Joan M Mastrobattista, Mark A Klebanoff, J Christopher Carey, John C Hauth, Cora A Macpherson, J Ernest, Margaret Cotroneo, Kenneth J Leveno, Ronald Wapner, Michael Varner, Jay D Iams, Atef Moawad, Baha M Sibai, Menachem Miodovnik, Mitchell Dombrowski, Mary J O'Sullivan, J Peter Vandorsten, Oded Langer

Faculty, Staff and Student Publications

Our objective was to determine the effect of body mass index (BMI) on response to bacterial vaginosis (BV) treatment. A secondary analysis was conducted of two multicenter trials of therapy for BV and TRICHOMONAS VAGINALIS. Gravida were screened for BV between 8 and 22 weeks and randomized between 16 and 23 weeks to metronidazole or placebo. Of 1497 gravida with asymptomatic BV and preconceptional BMI, 738 were randomized to metronidazole; BMI was divided into categories: < 25, 25 to 29.9, and > or = 30. Rates of BV persistence at follow-up were compared using the Mantel-Haenszel chi square. Multiple logistic regression was used to evaluate the effect …

Excess Adenosine In Murine Penile Erectile Tissues Contributes To Priapism Via A2b Adenosine Receptor Signaling, Tiejuan Mi, Shahrzad Abbasi, Hong Zhang, Karen Uray, Janci L Chunn, Ling Wei Xia, Jose G Molina, Norman W Weisbrodt, Rodney E Kellems, Michael R Blackburn, Yang Xia

Faculty, Staff and Student Publications

Priapism, abnormally prolonged penile erection in the absence of sexual excitation, is associated with ischemia-mediated erectile tissue damage and subsequent erectile dysfunction. It is common among males with sickle cell disease (SCD), and SCD transgenic mice are an accepted model of the disorder. Current strategies to manage priapism suffer from a poor fundamental understanding of the molecular mechanisms underlying the disorder. Here we report that mice lacking adenosine deaminase (ADA), an enzyme necessary for the breakdown of adenosine, displayed unexpected priapic activity. ADA enzyme therapy successfully corrected the priapic activity both in vivo and in vitro, suggesting that it was …

Clinical And Microbiological Aspects Of Linezolid Resistance Mediated By The Cfr Gene Encoding A 23s Rrna Methyltransferase, Cesar A Arias, Martha Vallejo, Jinnethe Reyes, Diana Panesso, Jaime Moreno, Elizabeth Castañeda, Maria V Villegas, Barbara E Murray, John P Quinn

Faculty, Staff and Student Publications

The cfr (chloramphenicol-florfenicol resistance) gene encodes a 23S rRNA methyltransferase that confers resistance to linezolid. Detection of linezolid resistance was evaluated in the first cfr-carrying human hospital isolate of linezolid and methicillin-resistant Staphylococcus aureus (designated MRSA CM-05) by dilution and diffusion methods (including Etest). The presence of cfr was investigated in isolates of staphylococci colonizing the patient's household contacts and clinical isolates recovered from patients in the same unit where MRSA CM-05 was isolated. Additionally, 68 chloramphenicol-resistant Colombian MRSA isolates recovered from hospitals between 2001 and 2004 were screened for the presence of the cfr gene. In addition to erm(B), …

Verb Generation In Children With Spina Bifida, Maureen Dennis, Derryn Jewell, Ross Hetherington, Christine Burton, Michael E. Brandt, Susan E. Blaser, Jack M Fletcher

Faculty, Staff and Student Publications

We investigated verb generation in children with spina bifida meningomyelocele (SBM; n = 55) and in typically developing controls (n = 32). Participants completed 6 blocks (40 trials each) of a task requiring them to produce a semantically related verb in response to a target noun and an additional 40 trials on which they were simply required to read target nouns aloud. After controlling for reading response time, groups did not differ significantly in verb generation response time or learning. Children with SBM produced more non-verb errors than controls and tended to repeat their mistakes over blocks. Verb generation performance …

Unique Structures In A Tumor Herpesvirus Revealed By Cryo-Electron Tomography And Microscopy, Wei Dai, Qingmei Jia, Eric Bortz, Sanket Shah, Jun Liu, Ivo Atanasov, Xudong Li, Kenneth A Taylor, Ren Sun, Z Hong Zhou

Faculty, Staff and Student Publications

Gammaherpesviruses, including the human pathogens Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, are causative agents of lymphomas and other malignancies. The structural characterization of these viruses has been limited due to difficulties in obtaining adequate amount of virion particles. Here we report the first three-dimensional structural characterization of a whole gammaherpesvirus virion by an emerging integrated approach of cryo-electron tomography combined with single-particle cryo-electron microscopy, using murine gammaherpesvirus-68 (MHV-68) as a model system. We found that the MHV-68 virion consists of distinctive envelope and tegument compartments, and a highly conserved nucleocapsid. Two layers of tegument are identified: an inner tegument layer …

Cryo-Electron Tomography Of Kaposi's Sarcoma-Associated Herpesvirus Capsids Reveals Dynamic Scaffolding Structures Essential To Capsid Assembly And Maturation, Binbin Deng, Christine M O'Connor, Dean H Kedes, Z Hong Zhou

Faculty, Staff and Student Publications

Kaposi's sarcoma-associated herpesvirus (KSHV) is a recently discovered DNA tumor virus that belongs to the gamma-herpesvirus subfamily. Though numerous studies on KSHV and other herpesviruses, in general, have revealed much about their multilayered organization and capsid structure, the herpesvirus capsid assembly and maturation pathway remains poorly understood. Structural variability or irregularity of the capsid internal scaffolding core and the lack of adequate tools to study such structures have presented major hurdles to earlier investigations employing more traditional cryo-electron microscopy (cryoEM) single particle reconstruction. In this study, we used cryo-electron tomography (cryoET) to obtain 3D reconstructions of individual KSHV capsids, allowing …

Activation Of Heat Shock And Antioxidant Responses By The Natural Product Celastrol: Transcriptional Signatures Of A Thiol-Targeted Molecule, Amy Trott, James D West, Lada Klaić, Sandy D Westerheide, Richard B Silverman, Richard I Morimoto, Kevin A Morano

Faculty, Staff and Student Publications

Stress response pathways allow cells to sense and respond to environmental changes and adverse pathophysiological states. Pharmacological modulation of cellular stress pathways has implications in the treatment of human diseases, including neurodegenerative disorders, cardiovascular disease, and cancer. The quinone methide triterpene celastrol, derived from a traditional Chinese medicinal herb, has numerous pharmacological properties, and it is a potent activator of the mammalian heat shock transcription factor HSF1. However, its mode of action and spectrum of cellular targets are poorly understood. We show here that celastrol activates Hsf1 in Saccharomyces cerevisiae at a similar effective concentration seen in mammalian cells. Transcriptional …

Sp1 Up-Regulates Camp-Response-Element-Binding Protein Expression During Retinoic Acid-Induced Mucous Differentiation Of Normal Human Bronchial Epithelial Cells, Jeong Soo Hong, Seung-Wook Kim, Ja Seok Koo

Faculty, Staff and Student Publications

CREB [CRE (cAMP-response element)-binding protein] is an important transcription factor that is differentially regulated in cells of various types. We recently reported that RA (retinoic acid) rapidly activates CREB without using RARs (RA receptors) or RXRs (retinoid X receptors) in NHTBE cells (normal human tracheobronchial epithelial cells). However, little is known about the role of RA in the physiological regulation of CREB expression in the early mucous differentiation of NHTBE cells. In the present study, we report that RA up-regulates CREB gene expression and that, using 5'-serial deletion promoter analysis and mutagenesis analyses, two Sp1 (specificity protein 1)-binding sites located …

Medulloblastomas Overexpress The P53-Inactivating Oncogene Wip1/Ppm1d, Robert C. Castellino, Massimiliano De Bortoli, Xiongbin Lu, Sung-Hwan Moon, Thuy-Ai Nguyen, Mark A. Shepard, Pulivarthi H. Rao, Lawrence A. Donehower, John Y H Kim

Faculty, Staff and Students Publications

Medulloblastoma is the most common malignant brain tumor of childhood. Despite numerous advances, clinical challenges range from recurrent and progressive disease to long-term toxicities in survivors. The lack of more effective, less toxic therapies results from our limited understanding of medulloblastoma growth. Although TP53 is the most commonly altered gene in cancers, it is rarely mutated in medulloblastoma. Accumulating evidence, however, indicates that TP53 pathways are disrupted in medulloblastoma. Wild-type p53-induced phosphatase 1 (WIP1 or PPM1D) encodes a negative regulator of p53. WIP1 amplification (17q22-q23) and its overexpression have been reported in diverse cancer types. We examined primary medulloblastoma specimens …

Focal White Matter Changes In Spasmodic Dysphonia: A Combined Diffusion Tensor Imaging And Neuropathological Study, Kristina Simonyan, Fernanda Tovar-Moll, John Ostuni, Mark Hallett, Victor F Kalasinsky, Michael R Lewin-Smith, Elisabeth J Rushing, Alexander O Vortmeyer, Christy L Ludlow

Faculty, Staff and Student Publications

Spasmodic dysphonia is a neurological disorder characterized by involuntary spasms in the laryngeal muscles during speech production. Although the clinical symptoms are well characterized, the pathophysiology of this voice disorder is unknown. We describe here, for the first time to our knowledge, disorder-specific brain abnormalities in these patients as determined by a combined approach of diffusion tensor imaging (DTI) and postmortem histopathology. We used DTI to identify brain changes and to target those brain regions for neuropathological examination. DTI showed right-sided decrease of fractional anisotropy in the genu of the internal capsule and bilateral increase of overall water diffusivity in …