Medical Specialties Commons^™

Histamine Reduces Flash Sensitivity Of On Ganglion Cells In The Primate Retina, Nikolay P Akimov, David W Marshak, Laura J Frishman, Randolph D Glickman, Rafail G Yusupov

Journal Articles

PURPOSE. In Old World primates, the retina receives input from histaminergic neurons in the posterior hypothalamus. They are a subset of the neurons that project throughout the central nervous system and fire maximally during the day. The contribution of these neurons to vision, was examined by applying histamine to a dark-adapted, superfused baboon eye cup preparation while making extracellular recordings from peripheral retinal ganglion cells. METHODS. The stimuli were 5-ms, 560-nm, weak, full-field flashes in the low scotopic range. Ganglion cells with sustained and transient ON responses and two cell types with OFF responses were distinguished; their responses were recorded …

Progressive Regression Of Left Ventricular Hypertrophy Two Years After Bariatric Surgery, Mohamed F Algahim, Thomas R Lux, Joshua G Leichman, Anthony F Boyer, Charles C Miller, Susan T Laing, Erik B Wilson, Terry Scarborough, Sherman Yu, Brad Snyder, Carol Wolin-Riklin, Ursula G Kyle, Heinrich Taegtmeyer

Journal Articles

BACKGROUND: Obesity is a systemic disorder associated with an increase in left ventricular mass and premature death and disability from cardiovascular disease. Although bariatric surgery reverses many of the hormonal and hemodynamic derangements, the long-term collective effects on body composition and left ventricular mass have not been considered before. We hypothesized that the decrease in fat mass and lean mass after weight loss surgery is associated with a decrease in left ventricular mass.

METHODS: Fifteen severely obese women (mean body mass index [BMI]: 46.7+/-1.7 kg/m(2)) with medically controlled hypertension underwent bariatric surgery. Left ventricular mass and plasma markers of systemic …

Cellular Dynamic Simulator: An Event Driven Molecular Simulation Environment For Cellular Physiology, Michael J Byrne, M Neal Waxham, Yoshihisa Kubota

Journal Articles

In this paper, we present the Cellular Dynamic Simulator (CDS) for simulating diffusion and chemical reactions within crowded molecular environments. CDS is based on a novel event driven algorithm specifically designed for precise calculation of the timing of collisions, reactions and other events for each individual molecule in the environment. Generic mesh based compartments allow the creation / importation of very simple or detailed cellular structures that exist in a 3D environment. Multiple levels of compartments and static obstacles can be used to create a dense environment to mimic cellular boundaries and the intracellular space. The CDS algorithm takes into …

A Direct Role For Secretory Phospholipase A2 And Lysophosphatidylcholine In The Mediation Of Lps-Induced Gastric Injury, Elizabeth J Dial, Duy M Tran, Jimmy J Romero, Mayssa Zayat, Lenard M Lichtenberger

Journal Articles

Endotoxemia from sepsis can injure the gastrointestinal tract through mechanisms that have not been fully elucidated. We have shown that LPS induces an increase in gastric permeability in parallel with the luminal appearance of secretory phospholipase A2 (sPLA2) and its product, lysophosphatidylcholine (lyso-PC). We proposed that sPLA2 acted on the gastric hydrophobic barrier, composed primarily of phosphatidylcholine (PC), to degrade it and produce lyso-PC, an agent that is damaging to the mucosa. In the present study, we have tested whether lyso-PC and/or sPLA2 have direct damaging effects on the hydrophobic barriers of synthetic and mucosal surfaces. Rats were administered LPS …

Thoracic Aortic Disease In Tuberous Sclerosis Complex: Molecular Pathogenesis And Potential Therapies In Tsc2+/- Mice, Jiumei Cao, Limin Gong, Dong-Chuan Guo, Ulrike Mietzsch, Shao-Qing Kuang, Callie S Kwartler, Hazim Safi, Anthony Estrera, Michael J Gambello, Dianna M Milewicz

Journal Articles

Tuberous sclerosis complex (TSC) is a genetic disorder with pleiotropic manifestations caused by heterozygous mutations in either TSC1 or TSC2. One of the less investigated complications of TSC is the formation of aneurysms of the descending aorta, which are characterized on pathologic examination by smooth muscle cell (SMC) proliferation in the aortic media. SMCs were explanted from Tsc2(+/-) mice to investigate the pathogenesis of aortic aneurysms caused by TSC2 mutations. Tsc2(+/-) SMCs demonstrated increased phosphorylation of mammalian target of rapamycin (mTOR), S6 and p70S6K and increased proliferation rates compared with wild-type (WT) SMCs. Tsc2(+/-) SMCs also had reduced expression of …

Perfusion In Rat Brain At 7 T With Arterial Spin Labeling Using Fair-Truefisp And Quipss, Emilio Esparza-Coss, Jarek Wosik, Ponnada A Narayana

Journal Articles

Measurement of perfusion in longitudinal studies allows for the assessment of tissue integrity and the detection of subtle pathologies. In this work, the feasibility of measuring brain perfusion in rats with high spatial resolution using arterial spin labeling is reported. A flow-sensitive alternating recovery sequence, coupled with a balanced gradient fast imaging with steady-state precession readout section was used to minimize ghosting and geometric distortions, while achieving high signal-to-noise ratio. The quantitative imaging of perfusion using a single subtraction method was implemented to address the effects of variable transit delays between the labeling of spins and their arrival at the …

Syntaxin 3b Is Essential For The Exocytosis Of Synaptic Vesicles In Ribbon Synapses Of The Retina, L Curtis, P Datta, X Liu, N Bogdanova, R Heidelberger, R Janz

Journal Articles

Ribbon synapses of the vertebrate retina are specialized synapses that release neurotransmitter by synaptic vesicle exocytosis in a manner that is proportional to the level of depolarization of the cell. This release property is different from conventional neurons, in which the release of neurotransmitter occurs as a short-lived burst triggered by an action potential. Synaptic vesicle exocytosis is a calcium regulated process that is dependent on a set of interacting synaptic proteins that form the so-called SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) complex. Syntaxin 3B has been identified as a specialized SNARE molecule in ribbon synapses of the …

Three-Dimensional Structure Of Tropism-Switching Bordetella Bacteriophage, Wei Dai, Asher Hodes, Wong H Hui, Mari Gingery, Jeff F Miller, Z Hong Zhou

Journal Articles

Bacteriophage BPP-1, which infects Bordetella species, can switch its specificity by mutations to the ligand-binding surface of its major tropism-determinant protein, Mtd. This targeted mutagenesis results from the activity of a phage-encoded diversity-generating retroelement. Purified Mtd binds its receptor with low affinity, yet BPP-1 binding and infection of Bordettella cells are efficient because of high-avidity binding between phage-associated Mtd and its receptor. Here, using an integrative approach of three-dimensional (3D) structural analyses of the entire phage by cryo-electron tomography and single-prticle cryo-electron microscopy, we provide direct localization of Mtd in the phage and the structural basis of the high-avidity binding …

Maternal And Neonatal Outcomes By Labor Onset Type And Gestational Age, Jennifer L Bailit, Kimberly D Gregory, Uma M Reddy, Victor H Gonzalez-Quintero, Judith U Hibbard, Mildred M Ramirez, D Ware Branch, Ronald Burkman, Shoshana Haberman, Christos G Hatjis, Matthew K Hoffman, Michelle Kominiarek, Helain J Landy, Lee A Learman, James Troendle, Paul Van Veldhuisen, Isabelle Wilkins, Liping Sun, Jun Zhang

Journal Articles

OBJECTIVE: We sought to determine maternal and neonatal outcomes by labor onset type and gestational age.

STUDY DESIGN: We used electronic medical records data from 10 US institutions in the Consortium on Safe Labor on 115,528 deliveries from 2002 through 2008. Deliveries were divided by labor onset type (spontaneous, elective induction, indicated induction, unlabored cesarean). Neonatal and maternal outcomes were calculated by labor onset type and gestational age.

RESULTS: Neonatal intensive care unit admissions and sepsis improved with each week of gestational age until 39 weeks (P < .001). After adjusting for complications, elective induction of labor was associated with a lower risk of ventilator use (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.28-0.53), sepsis (OR, 0.36; 95% CI, 0.26-0.49), and neonatal intensive care unit admissions (OR, 0.52; 95% CI, 0.48-0.57) compared to spontaneous labor. The relative risk of hysterectomy at term was 3.21 (95% CI, 1.08-9.54) with elective induction, 1.16 (95% CI, 0.24-5.58) with indicated induction, and 6.57 (95% CI, 1.78-24.30) with cesarean without labor compared to spontaneous labor.

CONCLUSION: Some neonatal outcomes improved until 39 weeks. Babies born with elective induction …

Humoral Immunity In Tuberculin Skin Test Anergy And Its Role In High-Risk Persons Exposed To Active Tuberculosis, Liliana Encinales, Joaquin Zuñiga, Julio Granados-Montiel, Maria Yunis, Julio Granados, Ingrid Almeciga, Olga Clavijo, Carlos Awad, Vilma Collazos, María Inés Vargas-Rojas, José Luis Bañales-Mendez, Lilia Vazquez-Castañeda, Joel N Stern, Viviana Romero, Masha Fridkis-Hareli, Masha Frindkis-Hareli, Daniel Terreros, Marcelo Fernandez-Viña, Edmond J Yunis

Journal Articles

The most common test to identify latent tuberculosis is the tuberculin skin test that detects T cell responses of delayed type hypersensitivity type IV. Since it produces false negative reactions in active tuberculosis or in high-risk persons exposed to tuberculosis patients as shown in this report, we studied antibody profiles to explain the anergy of such responses in high-risk individuals without active infection. Our results showed that humoral immunity against tuberculin, regardless of the result of the tuberculin skin test is important for protection from active tuberculosis and that the presence of high antibody titers is a more reliable indicator …

Temporal Lobe White Matter Asymmetry And Language Laterality In Epilepsy Patients, Timothy M Ellmore, Michael S Beauchamp, Joshua I Breier, Jeremy D Slater, Giridhar P Kalamangalam, Thomas J O'Neill, Michael A Disano, Nitin Tandon

Journal Articles

Recent studies using diffusion tensor imaging (DTI) have advanced our knowledge of the organization of white matter subserving language function. It remains unclear, however, how DTI may be used to predict accurately a key feature of language organization: its asymmetric representation in one cerebral hemisphere. In this study of epilepsy patients with unambiguous lateralization on Wada testing (19 left and 4 right lateralized subjects; no bilateral subjects), the predictive value of DTI for classifying the dominant hemisphere for language was assessed relative to the existing standard-the intra-carotid Amytal (Wada) procedure. Our specific hypothesis is that language laterality in both unilateral …

Cardiomyocyte Pdgfr-Beta Signaling Is An Essential Component Of The Mouse Cardiac Response To Load-Induced Stress, Vishnu Chintalgattu, Di Ai, Robert R Langley, Jianhu Zhang, James A Bankson, Tiffany L Shih, Anilkumar K Reddy, Kevin R Coombes, Iyad N Daher, Shibani Pati, Shalin S Patel, Jennifer S Pocius, George E Taffet, L Maximillian Buja, Mark L Entman, Aarif Y Khakoo

Journal Articles

PDGFR is an important target for novel anticancer therapeutics because it is overexpressed in a wide variety of malignancies. Recently, however, several anticancer drugs that inhibit PDGFR signaling have been associated with clinical heart failure. Understanding this effect of PDGFR inhibitors has been difficult because the role of PDGFR signaling in the heart remains largely unexplored. As described herein, we have found that PDGFR-beta expression and activation increase dramatically in the hearts of mice exposed to load-induced cardiac stress. In mice in which Pdgfrb was knocked out in the heart in development or in adulthood, exposure to load-induced stress resulted …

Elevated Albumin In Retinas Of Monkeys With Experimental Glaucoma, Louvenia Carter-Dawson, Yujin Zhang, Ronald S Harwerth, Ricky Rojas, Pramod Dash, Xinping C Zhao, Elizabeth Woldemussie, Guadalupe Ruiz, Alice Chuang, William P Dubinsky, John B Redell

Journal Articles

PURPOSE: To establish the identity of a prominent protein, approximately 70 kDa, that is markedly increased in the retina of monkeys with experimental glaucoma compared with the fellow control retina, the relationship to glaucoma severity, and its localization in the retina.

METHODS: Retinal extracts were subjected to 2-D gel electrophoresis to identify differentially expressed proteins. Purified peptides from the abundant 70 kDa protein were analyzed and identified by liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) separation, and collision-induced dissociation sequencing. Protein identity was performed on MASCOT (Matrix Science, Boston, MA) and confirmed by Western blot. The relationship between the increase in this …

A Woman With Hiv Infection, Brain Abscesses, And Eosinophilia, Marcela Campo, Man K Phung, Rehan Ahmed, Paul Cantey, Henry Bishop, Tanvir K Bell, Carolyn Gardiner, Cesar A Arias

Journal Articles

No abstract provided.

Safety, Tolerability, And Efficacy Of Fixed Combination Therapy With Dorzolamide Hydrochloride 2% And Timolol Maleate 05% In Glaucoma And Ocular Hypertension, Nicholas P Bell, José L Ramos, Robert M Feldman

Journal Articles

Glaucoma is a collection of diseases characterized by multifactorial progressive changes leading to visual field loss and optic neuropathy most frequently due to elevated intraocular pressure (IOP). The goal of treatment is the lowering of the IOP to prevent additional optic nerve damage. Treatment usually begins with topical pharmacological agents as monotherapy, progresses to combination therapy with agents from up to 4 different classes of IOP-lowering medications, and then proceeds to laser or incisional surgical modalities for refractory cases. The fixed combination therapy with the carbonic anhydrase inhibitor dorzolamide hydrochloride 2% and the beta blocker timolol maleate 0.5% is now …

Study Of Polytopic Membrane Protein Topological Organization As A Function Of Membrane Lipid Composition, Mikhail Bogdanov, Philip N Heacock, William Dowhan

Journal Articles

A protocol is described using lipid mutants and thiol-specific chemical reagents to study lipid-dependent and host-specific membrane protein topogenesis by the substituted-cysteine accessibility method as applied to transmembrane domains (SCAM). SCAM is adapted to follow changes in membrane protein topology as a function of changes in membrane lipid composition. The strategy described can be adapted to any membrane system.

Bicarbonate Enhances Expression Of The Endocarditis And Biofilm Associated Pilus Locus, Ebpr-Ebpabc, In Enterococcus Faecalis, Agathe Bourgogne, L Charlene Thomson, Barbara E Murray

Journal Articles

BACKGROUND: We previously identified ebpR, encoding a potential member of the AtxA/Mga transcriptional regulator family, and showed that it is important for transcriptional activation of the Enterococcus faecalis endocarditis and biofilm associated pilus operon, ebpABC. Although ebpR is not absolutely essential for ebpABC expression (100-fold reduction), its deletion led to phenotypes similar to those of an ebpABC mutant such as absence of pili at the cell surface and, consequently, reduced biofilm formation. A non-piliated ebpABC mutant has been shown to be attenuated in a rat model of endocarditis and in a murine urinary tract infection model, indicating an important participation …

Social Support In An Internet Weight Loss Community, Kevin O Hwang, Allison J Ottenbacher, Angela P Green, M Roseann Cannon-Diehl, Oneka Richardson, Elmer V Bernstam, Eric J Thomas

Journal Articles

PURPOSE: To describe social support for weight loss shared by members of a large Internet weight loss community.

METHODS: We conducted a mixed-methods study with surveys (n=193) and interviews (n=13) of community members along with a content analysis of discussion forum messages (n=1924 messages). Qualitative data were analyzed for social support themes.

RESULTS: Survey respondents were primarily white (91.4%) and female (93.8%) with mean age 37.3 years and mean body mass index 30.9. They used forums frequently, with 56.8% reading messages, 36.1% replying to messages, and 18.5% posting messages to start a discussion related to weight loss on a daily …