Vibrio shiloi, the causative agent of bleaching of the coral Oculina patagonica in the Mediterranean Sea, is present in all bleached O. patagonica corals in the summer (25-30 degrees C), but can be not detected in the coral during the winter (16-20 degrees C). Furthermore, the pathogen can not survive in O.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
July 2003
Changes in calcium (Ca2+) regulation contribute to loss of contractile function in dilated cardiomyopathy. Clinical treatment using beta-adrenergic receptor antagonists (beta-blockers) slows deterioration of cardiac function in end-stage heart failure patients; however, the effects of beta-blocker treatment on Ca2+ dynamics in the failing heart are unknown. To address this issue, tropomodulin-overexpressing transgenic (TOT) mice, which suffer from dilated cardiomyopathy, were treated with a nonselective beta-receptor blocker (5 mg.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
June 2003
Integrin-mediated cell-extracellular matrix (ECM) interactions are essential for multiple cellular processes; however, little is known regarding integrin turnover during these events. Recent studies have demonstrated shedding of cell surface molecules and suggested this as a potential mechanism for integrin turnover. Confocal microscopy of mouse hearts under different physiological conditions demonstrated the presence of beta(1)-integrin-immunoreactive material in the interstitium.
View Article and Find Full Text PDFBiomechanical signaling is a complex interaction of both intracellular and extracellular components. Both passive and active components are involved in the extracellular environment to signal through specific receptors to multiple signaling pathways. This review provides an overview of extracellular matrix, specific receptors, and signaling pathways for biomechanical stimulation in cardiac hypertrophy.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2002
Cytokinin-Independent 1 (CKI1) belongs to a group of putative plant histidine kinases whose members do not appear to act as ethylene receptors. The deduced protein structure, combined with the observation that Arabidopsis callus cultures overexpressing CKI1 exhibit a "cytokinin-independent" cell division and greening phenotype, led to the hypothesis that CKI1 is involved in cytokinin signaling, perhaps acting as a cytokinin receptor. To test the function of CKI1, we used a reverse-genetic approach to identify plants carrying T-DNA insertions in CKI1.
View Article and Find Full Text PDFMicroarrays containing 195,000 in situ synthesized oligonucleotide features have been created using a benchtop, maskless photolithographic instrument. This instrument, the Maskless Array Synthesizer (MAS), uses a digital light processor (DLP) developed by Texas Instruments. The DLP creates the patterns of UV light used in the light-directed synthesis of oligonucleotides.
View Article and Find Full Text PDFVariable-density (VD) spiral k-space acquisitions are used to acquire high-resolution (0.78 mm), motion-compensated images of the coronary arteries. Unlike conventional methods, information for motion compensation is obtained directly from the coronary anatomy itself.
View Article and Find Full Text PDFSodium (Na+) is toxic to most plants, but the molecular mechanisms of plant Na+ uptake and distribution remain largely unknown. Here we analyze Arabidopsis lines disrupted in the Na+ transporter AtHKT1. AtHKT1 is expressed in the root stele and leaf vasculature.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
February 2003
Introduction of the constitutively active calcineurin gene into neonatal rat cardiomyocytes by adenovirus resulted in decreased mitochondrial membrane potential (P < 0.05). Infection of H9c2 cells with calcineurin adenovirus resulted in increased superoxide production (P < 0.
View Article and Find Full Text PDFThe purpose of this study was to investigate the impact of three different ankle foot orthoses (AFO) configurations on the function and kinematics of stair locomotion in children with spastic hemiplegia. Nineteen children were evaluated barefoot and with a hinged, posterior leaf spring (PLS) and solid AFO during stair ascent and descent. Stair specific items from the Pediatric Evaluation of Disability Inventory (PEDI) were used to evaluate function, while a motion measurement system was used to evaluate kinematics.
View Article and Find Full Text PDFCellular remodeling during progression of dilation involves focal adhesion contact reorganization. However, the signaling mechanisms and structural consequences leading to impaired cardiomyocyte adhesion are poorly defined. These events were studied in tropomodulin-overexpressing transgenic mice that develop dilated cardiomyopathy associated with chronic elevation of intracellular calcium.
View Article and Find Full Text PDFPlants can grow in soils containing highly variable amounts of mineral nutrients, like Ca(2+) and Mn(2+), though the mechanisms of adaptation are poorly understood. Here, we report the first genetic study to determine in vivo functions of a Ca(2+) pump in plants. Homozygous mutants of Arabidopsis harboring a T-DNA disruption in ECA1 showed a 4-fold reduction in endoplasmic reticulum-type calcium pump activity.
View Article and Find Full Text PDFA key component of a sound functional genomics infrastructure is the availability of a knockout mutant for every gene in the genome. A fruitful approach to systematically knockingout genes in the plant Arabidopsis thaliana has been the use of transferred-DNA (T-DNA) from Agrobacterium tumefaciens as an insertional mutagen. One of the assumptions underlying the use of T-DNA as a mutagen is that the insertion of these DNA elements into the Arabidopsis genome occurs at randomly selected locations.
View Article and Find Full Text PDFThe signal transduction pathways that control cytokinesis in plants are largely uncharacterized. Here, we provide genetic evidence that mitogen-activated protein kinase kinase kinases (MAPKKKs) play a role in the control of plant cell division. Using a reverse-genetic approach, we isolated plants carrying knockout alleles of the Arabidopsis MAPKKK genes ANP1, ANP2, and ANP3.
View Article and Find Full Text PDFTo test the hypothesis that early interventional treatment with insulin-like growth factor-1 (IGF-1) alleviates subsequent development of dilated cardiomyopathy, cardiac-specific IGF-1 expression was introduced by selective cross-breeding into a transgenic mouse model of heart failure that displays phenotypic characteristics of severe dilation. Hemodynamic, structural, and cellular parameters of the heart were compared between nontransgenic, tropomodulin-overexpressing cardiomyopathic, and the hybrid tropomodulin/IGF-1-overexpressing mice. Beneficial effects of IGF-1 were apparent by multiple indices of cardiac structure and function, including normalization of heart mass, anatomy, hemodynamics, and apoptosis.
View Article and Find Full Text PDFObjectives: To examine changes in isometric muscle strength at the elbow, knee, and ankle at 6 months and 1 year after selective dorsal rhizotomy (SDR) and to determine if SDR altered the frequency of muscle cocontraction.
Design: Prospective outcome study of a consecutive sample.
Setting: Children's hospital.
Duchenne muscular dystrophy is an X-linked disease of muscle caused by an absence of the protein dystrophin. Affected boys begin manifesting signs of disease early in life, cease walking at the beginning of the second decade, and usually die by age 20 years. Until treatment of the basic genetic defect is available, medical, surgical, and rehabilitative approaches can be used to maintain patient function and comfort.
View Article and Find Full Text PDFTo monitor behaviors that place adolescents at increased risk for premature morbidity and mortality, the Centers for Disease Control and Prevention developed the Youth Risk Behavior Surveillance System (YRBSS). This system measures six categories of behaviors, including behaviors that contribute to violence and unintentional injuries; tobacco use; alcohol and other drug use; sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases, including HIV infection; unhealthy dietary behaviors; and inadequate physical activity. This article summarizes how some education and health agencies and nongovernmental organizations, in collaboration with community agencies, school boards, parents, and youth, use YRBSS data to describe risk behaviors, create awareness, supplement staff development, set and monitor program goals, develop health education programs, support health-related legislation, and seek funding.
View Article and Find Full Text PDFJ Thorac Cardiovasc Surg
December 2001
Objective: This study reviews the 223 consecutive mitral valve operations for ischemic mitral insufficiency performed at New York University Medical Center between January 1976 and January 1996. The results for mitral valve reconstruction are compared with those for prosthetic mitral valve replacement.
Methods: From January 1976 to January 1996, 223 patients with ischemic mitral insufficiency underwent mitral valve reconstruction (n = 152) or prosthetic mitral valve replacement (n = 71).
A reverse genetic strategy was used to isolate Arabidopsis plants containing "knockout" mutations in AKT1 and AKT2, two members of a K+ channel gene family. Comparative studies of growth and membrane properties in wild-type and mutant seedlings were performed to investigate the physiological functions of these two related channels. The growth rates of plants supplied with rate-limiting concentrations of K+ depended on the presence of AKT1 but not AKT2 channels.
View Article and Find Full Text PDFMutations in the cartilage oligomeric matrix protein (COMP) gene result in pseudoachondroplasia (PSACH), which is a chondrodysplasia characterized by early-onset osteoarthritis and short stature. COMP is a secreted pentameric glycoprotein that belongs to the thrombospondin family of proteins. We have identified a novel missense mutation which substitutes a glycine for an aspartic acid residue in the thrombospondin (TSP) type 3 calcium-binding domain of COMP in a patient diagnosed with PSACH.
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