Publications by authors named "Ronald Heimark"

Introduction: Among Hispanic-American (HA) men, prostatic cancer (PCa) accounts for nearly one-quarter of the total cancer burden. We sought to identify differences in PCa presentation and treatment status for HA subgroups based on country/region of origin.

Material And Methods: Using the National Cancer Database, we identified patients with histologically confirmed prostate adenocarcinoma with reported race/ethnicity, clinical staging, Gleason score ≥ 6, and PSA level at diagnosis from 2010 to 2016.

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Background: The United States is becoming increasingly diverse, but few molecular studies have assessed the progression of clear cell renal cell carcinoma (ccRCC) in diverse patient populations. This study examined ccRCC molecular variations in non-Hispanic White (NHW) and Hispanic patients and their effect on the association of gene expression with high-grade (Grade 3 or 4) ccRCC and overall mortality.

Methods: A total of 156 patients were included in VHL sequencing and/or TempO-Seq analysis.

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The organs of eukaryotic organisms comprise complex interspersions of cell types, whose different molecular activities, and corresponding cellular states, cooperate during development to produce the final, functional organ. Dysfunction of organs in disease, particularly oncogenesis, initiates with changes of state of a minor subset of cells. It therefore is hard to detect early molecular indicators of disease within an overwhelming background of normal cells.

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Purpose: Expression of the PGE2 receptor, EP4, is up-regulated during colorectal carcinogenesis. However the mechanism leading to deregulation of the EP4 receptor is not known. The present study was conducted to investigate the regulation of EP4 receptor by miRNAs.

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The majority of children with congenital heart disease now live into adulthood due to the remarkable surgical and medical advances that have taken place over the past half century. Because of this, adults now represent the largest age group with adult cardiovascular diseases. It includes patients with heart diseases that were not detected or not treated during childhood, those whose defects were surgically corrected but now need revision due to maladaptive responses to the procedure, those with exercise problems and those with age-related degenerative diseases.

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Background: The microRNA-200 family participates in the maintenance of an epithelial phenotype and loss of its expression can result in epithelial to mesenchymal transition (EMT). Furthermore, the loss of expression of miR-200 family members is linked to an aggressive cancer phenotype. Regulation of the miR-200 family expression in normal and cancer cells is not fully understood.

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Attachment, deformation and detachment of N-cadherin expressing prostate and breast cancer cell lines in a functionalized microchannel under hydrodynamic loading have been studied. N-cadherin antibodies are immobilized on the microchannel surface to capture the target cancer cells, PC3N and MDA-MB-231-N, from a homogeneous cell suspension. Although difficult, a significant fraction of moving cells can be captured under a low flow rate.

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It is generally believed that proteins of the troponin complex are not expressed in smooth muscle. We have directly assayed for expression of troponin transcripts in mouse vascular smooth muscle and found that troponin sequences normally associated with fast twitch skeletal muscle (fTnT, fTnI, fTnC) were present at significant levels in the thoracic aorta. In situ hybridization experiments demonstrated that fTnT, fTnI and fTnC transcripts were expressed in the smooth muscle layer of mouse blood vessels of all sizes.

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Accumulating evidence indicates that elevated levels of prostaglandin E(2) (PGE(2)) can increase intestinal epithelial cell proliferation, and thus play a role in colorectal tumorigenesis. PGE(2) exerts its effects through four G-protein-coupled PGE receptor (EP) subtypes, named the EP1, EP2, EP3, and EP4. Increased phosphorylation of extracellular regulated kinases (ERK1/2) is required for PGE(2) to stimulate cell proliferation of human colon cancer cells.

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A novel photolithography method to build aligned patterns of two different proteins is presented. Chessboard patterns of 125 microm x 125 microm squares are constructed on a silicon dioxide substrate, using standard photoresist chemistries in combination with low-temperature oxygen plasma etching. Low-melting-point agarose (LMPA) is used to protect underlying protein layers and, at the appropriate stage, the digestive enzyme GELase (EPICENTRE) is used to selectively remove the prophylactic LMPA layers.

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The peptide growth factor apelin is the high affinity ligand for the G-protein-coupled receptor APJ. During embryonic development of mouse and frog, APJ receptor is expressed at high levels in endothelial precursor cells and in nascent vascular structures. Characterization of Xenopus apelin shows that the sequence of the bioactive region of the peptide is perfectly conserved between frogs and mammals.

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The gain of N-cadherin expression in carcinomas has been shown to be important in the regulation of cell migration, invasion, and survival. Here, we show that N-cadherin mRNA expression in PC-3 prostate carcinoma cells is dependent on beta(1) integrin-mediated cell adhesion to fibronectin and the basic helix-loop-helix transcription factor Twist1. Depletion of Twist1 mRNA by small interfering RNA resulted in decreased expression of both Twist1 and N-cadherin and the inhibition of cell migration.

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A novel self-aligned method to selectively immobilize proteins on a silicon dioxide surface is developed in conjunction with a standard lift-off patterning technique of a PEG layer. The approach is designed to photolithographically pattern regions that specifically bind target proteins and particles, surrounded by regions that suppress non-specific attachment of bio-species. The physical and biological properties of the derivatized surfaces at the end of the fabrication process are characterized.

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Although it is known that MEKK4 regulates MKK6, and p38 MAP kinase, extracellular stimuli that activate the serine/threonine kinase, MEKK4, are unknown. The aim of this study was then to identify stimuli that regulate MEKK4. By using recombinant MEKK4, as bait to attract interacting proteins, the calcium binding protein, annexin II, was identified by mass spectrometry as interacting with MEKK4, suggesting that MEKK4 might be regulated by calcium.

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During embryonic development, the first blood vessels are formed through the aggregation and subsequent assembly of angioblasts (endothelial precursors) into a network of endothelial tubes, a process known as vasculogenesis. These first vessels generally form in mesoderm that is adjacent to endodermal tissue. Although specification of the angioblast lineage is independent of endoderm interactions, a signal from the endoderm is necessary for angioblasts to assemble into a vascular network and to undergo vascular tube formation.

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Objectives: To characterize endothelial cell-to-cell junctions in the sinusoids and microvasculature of the corpus cavernosum.

Methods: Corporal tissue was obtained from 6 potent human subjects, cut into 5-microm cryosections, and double-labeled with consecutive applications of primary and secondary antibodies. Laser scanning confocal microscopy identified subcellular localization of endothelial anchoring and adhesion molecules.

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Purpose. The majority of resistance to outflow of aqueous humor resides at or near the inner wall of Schlemm's canal (SC). Transmembrane proteins that contribute to the generation of resistance to aqueous outflow likely participate in junctional complexes between SC cells.

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Associated with the metastatic progression of epithelial tumors is the dynamic regulation of cadherins. Whereas E-cadherin is expressed in most epithelium and carcinomas, recent studies suggest that the up-regulation of other cadherin subtypes in carcinomas, such as N-cadherin, may function in cancer progression. We demonstrate that a signal transduction cascade links the N-cadherin.

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