Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 11 of 11

Full-Text Articles in Medicine and Health Sciences

Imaging Activity Of Neuronal Populations With New Long-Wavelength Voltage-Sensitive Dyes, Joseph P. Wuskell, Leslie M. Loew Dec 2008

Imaging Activity Of Neuronal Populations With New Long-Wavelength Voltage-Sensitive Dyes, Joseph P. Wuskell, Leslie M. Loew

UCHC Articles - Research

We have assessed the utility of five new long-wavelength fluorescent voltage-sensitive dyes (VSD) for imaging the activity of populations of neurons in mouse brain slices. Although all the five were capable of detecting activity resulting from activation of the Schaffer collateral-CA1 pyramidal cell synapse, they differed significantly in their properties, most notably in the signal-to-noise ratio of the changes in dye fluorescence associated with neuronal activity. Two of these dyes, Di-2-ANBDQPQ and Di-1-APEFEQPQ, should prove particularly useful for imaging activity in brain tissue and for combining VSD imaging with the control of neuronal activity via light-activated proteins such as channelrhodopsin-2 …


Use Of An Alpha-Smooth Muscle Actin (Smaa) Gfp Reporter To Identify An Osteoprogenitor Population, Zana Kalajzic, Haitao Li, Li-Ping Wang, Xi Jiang, Katie B. Lamothe, Douglas J. Adams, Hector L. Aguila, David W. Rowe, Ivo Kalajzic Sep 2008

Use Of An Alpha-Smooth Muscle Actin (Smaa) Gfp Reporter To Identify An Osteoprogenitor Population, Zana Kalajzic, Haitao Li, Li-Ping Wang, Xi Jiang, Katie B. Lamothe, Douglas J. Adams, Hector L. Aguila, David W. Rowe, Ivo Kalajzic

UCHC Articles - Research

Identification of a reliable marker of skeletal precursor cells within calcified and soft tissues remains a major challenge for the field. To address this, we used a transgenic model in which osteoblasts can be eliminated by pharmacological treatment. Following osteoblast ablation a dramatic increase in a population of α-smooth muscle actin (α-SMA) positive cells was observed. During early recovery phase from ablation we have detected cells with the simultaneous expression of SMAA and a preosteoblastic 3.6GFP marker, indicating the potential for transition of α-SMA+ cells towards osteoprogenitor lineage. Utilizing α-SMAGFP transgene, α-SMAGFP+ positive cells were detected in the …


A Crucial Role In Cell Spreading For The Interaction Of Abl Pxxp Motifs With Crk And Nck Adaptors, Susumu Antoku, Gonzalo M. Rivera, Bruce J. Mayer Sep 2008

A Crucial Role In Cell Spreading For The Interaction Of Abl Pxxp Motifs With Crk And Nck Adaptors, Susumu Antoku, Gonzalo M. Rivera, Bruce J. Mayer

UCHC Articles - Research

The dynamic reorganization of actin structures helps to mediate the interaction of cells with their environment. The Abl non-receptor tyrosine kinase can modulate actin rearrangement during cell attachment. Here we report that the Abl PxxP motifs, which bind Src homology 3 (SH3) domains, are indispensable for the coordinated regulation of filopodium and focal adhesion formation and cell-spreading dynamics during attachment. Candidate Abl PxxP-motif-binding partners were identified by screening a comprehensive SH3-domain phage-display library. A combination of protein overexpression, silencing, pharmacological manipulation and mutational analysis demonstrated that the PxxP motifs of Abl exert their effects on actin organization by two distinct …


Microsome Biocolloids For Rapid Drug Metabolism And Inhibition Assessment By Lc-Ms, Besnik Bajrami, Sadagopan Krishnan, James F. Rusling Aug 2008

Microsome Biocolloids For Rapid Drug Metabolism And Inhibition Assessment By Lc-Ms, Besnik Bajrami, Sadagopan Krishnan, James F. Rusling

UCHC Articles - Research

Rat liver microsomes attached to nanoparticles were used for LC-MS studies of CYP3A and 2E1 enzymes in metabolism of N-nitroso compounds. Using these biocolloids, turnover rates were measured within 2 min. Inhibitor IC50 values for ketoconazole (KET) and 4-methylpyrazole (4-MEP) were estimated.


Synergistic Metabolic Toxicity Screening Using Microsome/Dna Electrochemiluminescent Arrays And Nanoreactors, Sadagopan Krishnan, Eli G. Hvastkovs, Besnik Bajrami, Dharamainder Choudhary, John B. Schenkman, James F. Rusling Jul 2008

Synergistic Metabolic Toxicity Screening Using Microsome/Dna Electrochemiluminescent Arrays And Nanoreactors, Sadagopan Krishnan, Eli G. Hvastkovs, Besnik Bajrami, Dharamainder Choudhary, John B. Schenkman, James F. Rusling

UCHC Articles - Research

Platforms based on thin enzyme/DNA films were used in two-tier screening of chemicals for reactive metabolites capable of producing toxicity. Microsomes were used for the first time as sources of cytochrome (cyt) P450 enzymes in these devices. Initial rapid screening involved electrochemiluminescent (ECL) arrays featuring spots containing ruthenium poly(vinylpyridine), DNA, and rat liver microsomes or bicistronically expressed human cyt P450 2E1 (h2E1). Cyt P450 enzymes were activated via the NADPH/reductase cycle. When bioactivation of substrates in the films gives reactive metabolites, they are trapped by covalent attachment to DNA bases. The rate of increase in ECL with enzyme reaction time …


Subcutaneous Late Phase Responses Are Augmented During Local Inhalational Tolerance In A Murine Asthma Model, Anurag Singh, Roger S. Thrall, Linda A. Guernsey, William F. Carson Iv, Eric R. Secor Jr, Robert E. Cone, Thiruchandurai V. Rajan, Craig M. Schramm Jun 2008

Subcutaneous Late Phase Responses Are Augmented During Local Inhalational Tolerance In A Murine Asthma Model, Anurag Singh, Roger S. Thrall, Linda A. Guernsey, William F. Carson Iv, Eric R. Secor Jr, Robert E. Cone, Thiruchandurai V. Rajan, Craig M. Schramm

UCHC Articles - Research

Acute exposure of sensitized mice to antigen elicits allergic airway disease (AAD) characterized by Th2 cytokine-dependent pulmonary eosinophilia, methacholine hyperresponsiveness and antigen-specific IgE elevation. However, chronic exposure induces a local inhalational tolerance (LIT), with resolution of the airway responses but persistent systemic IgE production. To further determine if systemic immunologic responses were maintained during LIT, we assessed subcutaneous late phase responses to ovalbumin in this model. Sensitized and AAD mice developed small subcutaneous responses to ovalbumin, with footpad thickness increasing to 113.7 and 113.6% of baseline, respectively. In comparison, LIT mice developed marked foot swelling (141.6%). Histologic examination confirmed increased …


Molecular Biology: Power Sequencing, Brenton R. Graveley Jun 2008

Molecular Biology: Power Sequencing, Brenton R. Graveley

UCHC Articles - Research

Advances in DNA-sequencing technology provide unprecedented insight into the entire collection of four genomes' transcribed sequences; they herald a new era in the study of gene regulation and genome function.


Expression And Function Of Dlx Genes In The Osteoblast Lineage, Haitao Li, Inga Marijanovic, Mark S. Kronenberg, Ivana Erceg, Mary Louise Stover, Dimitrios Velonis, Mina Mina, William B. Upholt, Ivo Kalajzic, Alexander C. Lichtler Apr 2008

Expression And Function Of Dlx Genes In The Osteoblast Lineage, Haitao Li, Inga Marijanovic, Mark S. Kronenberg, Ivana Erceg, Mary Louise Stover, Dimitrios Velonis, Mina Mina, William B. Upholt, Ivo Kalajzic, Alexander C. Lichtler

UCHC Articles - Research

Our laboratory and others have shown that overexpression of Dlx5 stimulates osteoblast differentiation. Dlx5−/−/Dlx6−/− mice have more severe craniofacial and limb defects than Dlx5−/−, some of which are potentially due to defects in osteoblast maturation. We wished to investigate the degree to which other Dlx genes compensate for the lack of Dlx5, thus allowing normal development of the majority of skeletal elements in Dlx5−/− mice. Dlx gene expression in cells from different stages of the osteoblast lineage isolated by FACS sorting showed that Dlx2, Dlx5 and Dlx6 are expressed most strongly in less mature …


Roles Of Fgfr3 During Morphogenesis Of Meckel's Cartilage And Mandibular Bones, Bruce A. Havens, Dimitris Velonis, Mark S. Kronenberg, Alex C. Lichtler, Bonnie Oliver, Mina Mina Apr 2008

Roles Of Fgfr3 During Morphogenesis Of Meckel's Cartilage And Mandibular Bones, Bruce A. Havens, Dimitris Velonis, Mark S. Kronenberg, Alex C. Lichtler, Bonnie Oliver, Mina Mina

UCHC Articles - Research

To address the functions of FGFR2 and FGFR3 signaling during mandibular skeletogenesis, we over-expressed in the developing chick mandible, replication-competent retroviruses carrying truncated FGFR2c or FGFR3c that function as dominant negative receptors (RCAS-dnFGFR2 and RCAS-dnFGFR3). Injection of RCAS-dnFGFR3 between HH15−20 led to reduced proliferation, increased apoptosis, and decreased differentiation of chondroblasts in Meckel's cartilage. These changes resulted in the formation of a hypoplastic mandibular process and truncated Meckel's cartilage. This treatment also affected the proliferation and survival of osteoprogenitor cells in osteogenic condensations, leading to the absence of five mandibular bones on the injected side. Injection of RCAS-dnFGFR2 between HH15−20 …


Accurate Dna Fragment Sizing By Capillary Electrophoresis With Laser-Induced Fluorescence Array For Detection Of Sequence Specificity Of Dna Damage, Erwin V. Fundador, Dharamainder Choudhary, John B. Schenkman, James F. Rusling Mar 2008

Accurate Dna Fragment Sizing By Capillary Electrophoresis With Laser-Induced Fluorescence Array For Detection Of Sequence Specificity Of Dna Damage, Erwin V. Fundador, Dharamainder Choudhary, John B. Schenkman, James F. Rusling

UCHC Articles - Research

Cancer has been linked to mutations within specific codons in genes that code for critical biomolecules such as tumor suppressor proteins (e.g., p53). Activated metabolites like benzo[a]pyrenediol epoxide act on preferred nucleotide sequences of DNA, and such mutations have been identified in cancers. DNA reaction site identification depends on accurate analysis of oligonucleotide fragment sizes produced by strand breakage at the damaged sites. Herein, we report a new method for DNA fragment sizing using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). Absolute sizing accuracy and speed are achieved by utilizing a CE-LIF array with two-color fluorescence detection. Accuracy …


Biochemical Applications Of Ultrathin Films Of Enzymes, Polyions And Dna, James F. Rusling, Dominic O. Hull, Eli G. Hvastkovs, John B. Schenkman Jan 2008

Biochemical Applications Of Ultrathin Films Of Enzymes, Polyions And Dna, James F. Rusling, Dominic O. Hull, Eli G. Hvastkovs, John B. Schenkman

UCHC Articles - Research

This feature article summarizes recent applications of ultrathin films of enzymes and DNA assembled layer-by-layer (LbL). Using examples mainly from our own research, we focus on systems developed for biocatalysis and biosensors for toxicity screening. Enzyme–poly(l-lysine) (PLL) films, especially when stabilized by crosslinking, can be used for biocatalysis at unprecedented high temperatures or in acidic or basic solutions on electrodes or sub-micron sized beads. Such films have bright prospects for chiral synthesis and biofuel cells. Excellent bioactivity and retention of enzyme structure in these films facilitates their use in detailed kinetic studies. Biosensors and arrays employing DNA–enzyme films show great …