Digital Commons Network^™

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 …

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 …

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

Faculty, Staff and Student Publications

No abstract provided.

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 …

Killing Of Human Melanoma Cells Induced By Activation Of Class I Interferon-Regulated Signaling Pathways Via Mda-7/Il-24, Suhendan Ekmekcioglu, John B Mumm, Malini Udtha, Sunil Chada, Elizabeth A Grimm

Faculty, Staff and Student Publications

Restoration of the tumor-suppression function by gene transfer of the melanoma differentiation-associated gene 7 (MDA7)/interleukin 24 (IL-24) successfully induces apoptosis in melanoma tumors in vivo. To address the molecular mechanisms involved, we previously revealed that MDA7/IL-24 treatment of melanoma cells down-regulates interferon regulatory factor (IRF)-1 expression and concomitantly up-regulates IRF-2 expression, which competes with the activity of IRF-1 and reverses the induction of IRF-1-regulated inducible nitric oxide synthase (iNOS). Interferons (IFNs) influence melanoma cell survival by modulating apoptosis. A class I IFN (IFN-alpha) has been approved for the treatment of advanced melanoma with some limited success. A class II IFN …

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. …

Journal Table Of Contents Via Rss Feeds, Houston Academy Of Medicine-Texas Medical Center Library

Insider Express (2003-2013)

No abstract provided.

Changing The Face Of Medicine Library Programs, Vol.6 (3) May - June 2008, Houston Academy Of Medicine-Texas Medical Center Library

The Insider (2003-2008)

No abstract provided.

Changing The Face Of Medicine Library Programs, Vol.21 (4) April - June 2008, Houston Academy Of Medicine-Texas Medical Center Library

Library Lines (1998-2009)

No abstract provided.

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. …

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, …

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 …

Changing The Face Of Medicine: Celebrating America's Women, Vol.6 (2) March - April 2008, Houston Academy Of Medicine-Texas Medical Center Library

The Insider (2003-2008)

No abstract provided.

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 …

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 …

Pubmed Alerts:E-Mail Notification, Houston Academy Of Medicine-Texas Medical Center Library

Insider Express (2003-2013)

No abstract provided.

New Resources, Vol.21 (3) January - March 2008, Houston Academy Of Medicine-Texas Medical Center Library

Library Lines (1998-2009)

No abstract provided.

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), …

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 …

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 …

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 …

Save The Date: Digital Discovery Conference, March 27, 2008 Vol.6 (1) January - February 2008, Houston Academy Of Medicine-Texas Medical Center Library

The Insider (2003-2008)

No abstract provided.

Save The Date Digital Discovery Conference, Houston Academy Of Medicine-Texas Medical Center Library

Insider Express (2003-2013)

No abstract provided.

Dissociation Predicts Later Attention Problems In Sexually Abused Children, Julie B Kaplow, Erin Hall, Karestan C Koenen, Kenneth A Dodge, Lisa Amaya-Jackson

Faculty, Staff and Students Publications

OBJECTIVE: The goals of this research are to develop and test a prospective model of attention problems in sexually abused children that includes fixed variables (e.g., gender), trauma, and disclosure-related pathways.

METHODS: At Time 1, fixed variables, trauma variables, and stress reactions upon disclosure were assessed in 156 children aged 8-13 years. At the Time 2 follow-up (8-36 months following the initial interview), 56 of the children were assessed for attention problems.

RESULTS: A path analysis involving a series of hierarchically nested, ordinary least squares multiple regression analyses indicated two direct paths to attention problems including the child's relationship to …

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 …

Molecular Studies In Treponema Pallidum Evolution: Toward Clarity?, Connie J. Mulligan, Steven J. Norris, Sheila A. Lukehart

Faculty, Staff and Student Publications

No abstract provided.