Plant endogenous small RNAs (sRNAs) are important regulators of gene expression. There are two broad categories of plant sRNAs: microRNAs (miRNAs) and endogenous short interfering RNAs (siRNAs). MicroRNA loci are relatively well-annotated but compose only a small minority of the total sRNA pool; siRNA locus annotations have lagged far behind.
View Article and Find Full Text PDFDodders (Cuscuta spp.) are obligate parasitic plants that obtain water and nutrients from the stems of host plants via specialized feeding structures called haustoria. Dodder haustoria facilitate bidirectional movement of viruses, proteins and mRNAs between host and parasite, but the functional effects of these movements are not known.
View Article and Find Full Text PDFMassive bleeding from a tracheostomy developed in a 65-year-old woman with stroke after successful conservative management of a minor tracheostomy bleeding episode. Temporary hemostasis was achieved, and angiography showed a tracheoinnominate fistula (TIF), a rare complication of tracheostomy. Open surgery was contraindicated in this patient, so endovascular repair using a stent graft was performed.
View Article and Find Full Text PDFThe objective of this study was to assess the effects of two structurally distinct yet selective proteasome inhibitors (PS-341 and lactacystin) on leukocyte adhesion, endothelial cell adhesion molecule (ECAM) expression, and nuclear factor-kappaB (NF-kappaB) activation in tumor necrosis factor (TNF)-alpha-stimulated human umbilical vein endothelial cells (HUVEC) and the transformed, HUVEC-derived, ECV cell line. We found that TNF (10 ng/ml) significantly enhanced U-937 and polymorphonuclear neutrophil (PMN) adhesion to HUVEC but not to ECV; TNF also significantly enhanced surface expression of vascular cell adhesion molecule 1 and E-selectin (in HUVEC only), as well as intercellular adhesion molecule 1 (ICAM-1; in HUVEC and ECV). Pretreatment of HUVEC with lactacystin completely blocked TNF-stimulated PMN adhesion, partially blocked U-937 adhesion, and completely blocked TNF-stimulated ECAM expression.
View Article and Find Full Text PDFWe compared U-937 cell adhesion and adhesion molecule expression in human umbilical venous (HUVECs) and arterial (HUAECs) endothelial cells exposed to tumor necrosis factor (TNF), interleukin-1, and lipopolysaccharide (LPS). TNF and LPS stimulated vascular cell adhesion molecule (VCAM)-1 surface expression and adhesion of U-937 monocyte-like cells to HUVECs but not to HUAECs. Antibody studies demonstrated that in HUVECs at least 75% of the adhesion response is VCAM-1 mediated.
View Article and Find Full Text PDFBackground And Purpose: The components of a carotid artery plaque might affect the risk of ipsilateral stroke. The accuracy of carotid duplex scan in assessing stroke risk reflects the experience of the scan reader. Thus, methods that can enhance ultrasonic evaluation of plaque morphology might allow a more objective means of determining carotid-mediated stroke risk.
View Article and Find Full Text PDFThe effects of intermittent pneumatic compression on the healing rates of ulcers in patients with chronic venous insufficiency were examined in a prospective, controlled study of 22 patients. Patients were randomly assigned to the experimental or the control group. Both groups received local wound care followed by application of an Unna boot.
View Article and Find Full Text PDFPurpose: A prosthetic venous valve must be biocompatible and nonthrombogenic and function in the venous circulation. Biocompatibility and thrombogenicity of our prosthesis have been examined in prior animal experiments, and 91% of valve conduits including early prototypes are patent at 3 weeks. However, evaluation of valve function is much more difficult in animals; therefore in this study the function of excised valves was evaluated ex vivo.
View Article and Find Full Text PDFThe performance of fresh and glutaraldehyde fixed bovine jugular vein valves (10 mm diameter) was investigated in an experimental flow loop that provides adjustable flow rates and a downstream oscillatory pressure. Three different venous valve (VV) conduit geometries (curved [C], straight [S], and tapered [T]), were tested. The flow loop consisted of two independently adjustable components, with the mean flow generated by adjusting the elevation difference between the head tank and outflow chamber.
View Article and Find Full Text PDFAir embolization through a residual track after removal of a central venous catheter is an elusive mechanism of a treacherous problem. Prompt diagnosis is necessary for successful application of established therapy, as demonstrated by this case report. Awareness of this unusual mechanism of air embolism with utilization of simple prophylactic measures, however, remains the best treatment.
View Article and Find Full Text PDFThe need to test prosthetic venous valves led to the design of a hydraulic mock circuit that reliably mimics natural venous flow. Components of this system simulate calf muscle pump and thoracoabdominal suction pump action. Flow and pressures are serially measured along the circuit.
View Article and Find Full Text PDFChronic venous insufficiency is a frequent sequel to lower extremity venous thrombosis. A relatively uncommon, but potentially lethal, cause of the thrombosis is congenital antithrombin III deficiency. Recognition and treatment of this occult deficiency is critical.
View Article and Find Full Text PDFThe unsolved problem of valvular incompetence is a common denominator to chronic venous insufficiency. Cardiac experience with tissue valves suggests the potential for their use in more peripheral locations. The current initial work evaluated 22 valvular xenografts placed in the inferior vena cavas of 22 dogs.
View Article and Find Full Text PDFSpontaneous gastrojejunal fistula formation is rare and its differential diagnosis multifactorial. Precise etiologic determination is necessary for proper management. We have reported a case typical of gastrojejunal fistula due to peptic ulcer disease.
View Article and Find Full Text PDFThe response of the kidney to ischemia-induced cellular acidosis was followed over the immediate one hr post-ischemia reflow period. Clearance and extraction experiments as well as measurement of cortical intracellular pH (pHi) were performed on Inactin-anesthetized Sprague-Dawley rats. Arteriovenous concentration differences and para-aminohippurate extraction were obtained by cannulating the left renal vein.
View Article and Find Full Text PDFIndications for venous reconstruction after traumatic injury are controversial, partly because of uncertainty of continued patency. We found no reports in the literature of truly long-term results after venous reconstruction. For clarification of this issue, we reviewed femoral venous injuries in a civilian metropolital population over a 20-year period.
View Article and Find Full Text PDFBioprosthetic valves were surgically placed in the inferior vena cava of four canines as a first step in the investigation of prosthetic valves for the treatment of nonobstructive chronic venous stasis. Valve patency and thrombus formation involving either the valve or the IVC was evaluated by serial follow-up inferior vena cavagrams in each canine. No thrombus occurred in any of the canines as observed at six months in two canines and eight months in two canines.
View Article and Find Full Text PDFOnly a small subset of patients with combined superficial femoral artery and vein injuries results in amputation. The importance of the venous component as a risk factor for amputation is uncertain. Ligation vs.
View Article and Find Full Text PDFThe release of gamma-glutamyltransferase from renal tubule cells was studied in situ following 30 minutes of ischemia. The ischemic kidney enzyme level fell 33 percent after 15 minutes of reflow of which only 1.2 percent was recovered in the urine; none was released into the renal vein.
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