Populus root salicinoid phenolic glycosides are not mobilized to support metabolism and regrowth under carbon limited conditions.

Remobilization of carbon storage compounds in trees is crucial for the resilience to disturbances, stress, and the requirements of their perennial lifestyle, all of which can impact photosynthetic carbon gain. Trees contain abundant non-structural carbohydrates (NSC) in the form of starch and sugars for long term carbon storage, yet questions remain about the ability of trees to remobilize non-conventional carbon compounds under stress. Aspens, like other members of the genus Populus, have abundant specialized metabolites called salicinoid phenolic glycosides, which contain a core glucose moiety. In this study, we hypothesized that the glucose-containing salicinoids could be remobilized as an additional carbon source during severe carbon limitation. We made use of genetically modified hybrid aspen (Populus tremula x P. alba) with minimal salicinoid content and compared these to control plants with high salicinoid content during resprouting (suckering) in dark (carbon limited) conditions. As salicinoids are abundant anti-herbivore compounds, identification of such a secondary function for salicinoids may provide insight to the evolutionary pressures that drive their accumulation. Our results show that salicinoid biosynthesis is maintained during carbon limitation and suggests that salicinoids are not remobilized as a carbon source for regenerating shoot tissue. However, we found that salicinoid-producing aspens had reduced resprouting capacity per available root biomass when compared to salicinoid-deficient aspens. Therefore, our work shows that the constitutive salicinoid production in aspens can reduce the capacity for resprouting and survival in carbon limited conditions.

"The challenge facing renal artery revascularization: what have we not proven and why we must"?

Endovascular renal artery stent therapy for atherosclerotic renal artery stenosis (RAS) is associated with excellent acute technical success, low complication rates and acceptable long-term patency. However, the clinical benefits to patients of renal artery stenting remain uncertain. To facilitate debate regarding the treatment of RAS, we need to understand the epidemiology, basic physiology and clinical consequences of renal artery stenosis. We must attempt to determine which patients are likely to benefit from renal artery stenting, assess the nuances of the percutaneous procedure and review the current literature pertaining to renal artery stenting.

A retrospective study of the clinical experience of the implantable loop recorder in a paediatric setting.

The implantable loop recorder (ILR) has proved highly efficacious in the management of syncope, presyncope and palpitations in selected populations. Limited information regarding patient selection and diagnostic yield exists in the paediatric setting. A retrospective evaluation of patients who underwent ILR implantation over a 66-month period, in a tertiary paediatric cardiology unit was conducted. Twenty-three patients (10 male, 13 female) following initial assessment and investigation, were referred for device implantation. The mean age at time of ILR insertion was 11.39 +/- 4.34 (range, 2.0-16.8) years. The indications for ILR were recurrent syncope (n = 11), presyncope (n = 3) or palpitations (n = 9). Four (17.4%) patients had structural heart disease, three (13%) had a positive family history of sudden cardiac death and one (4%) had perinatal arrhythmia. One patient required ILR repositioning, and pocket infection necessitated explantation in one further patient. Minimum follow-up was 7.8 months during which symptoms were reported in 15 (65.2%) patients post-ILR insertion. Eight (34.7%) remained asymptomatic. Of the 15 who experienced symptom recurrence, eight (53.3%) had an arrhythmia recorded. Tachycardias recorded were polymorphic ventricular tachycardia (n = 1) and supraventricular tachycardia (n = 5). Clinically significant bradycardias documented, included sinus arrest (n = 1) and Mobitz type II second degree atrioventricular block (n = 1). The ILR had a high diagnostic yield, enabling an arrhythmic or non-arrhythmic diagnosis in 65.2% of patients with recurrent syncope, presyncope or palpitations in a selected paediatric population.

Selection of drugs in pursuit of rate control strategy.

Atrial fibrillation is the most common sustained arrhythmia. Based on multiple large randomized trials, rate control therapy has been shown to be safe and effective and is gaining greater acceptance as a frontline alternative to drugs to maintain sinus rhythm. Adequate rate control can be achieved by atrioventricular nodal blocking agents both in the acute and chronic settings. In refractory patients, other methods such as atrioventricular node ablation can be used to control rate.

A review of the pharmacokinetics, electrophysiology and clinical efficacy of dronedarone.

The results of major clinical trials and advances in pharmacologic and nonpharmacologic therapies are continuing to alter treatment approaches for both atrial and ventricular arrhythmias. Originally developed as an antianginal medication, amiodarone serves as the most effective antiarrhythmic drug in the treatment of both atrial and life-threatening ventricular arrhythmias. However, amiodarone has complex pharmacokinetics and is associated with serious extracardiac side effects, partially due to the presence of an iodine moiety. With a better understanding of the mechanisms of arrhythmias and antiarrhythmic drugs, new antiarrhythmic agents are currently under development with the hope that they will be more effective and safer than currently available drugs. One such drug that might potentially fulfill this hope is dronedarone. This amiodarone-like compound lacks the iodine moiety, and is similar in structure and electrophysiologic mechanisms of action to amiodarone, to date no evidence of liver, thyroid or pulmonary toxicity has been reported. Three clinical trials demonstrate efficacy in suppressing recurrences of atrial fibrillation and there is also evidence of a rate-slowing benefit during atrial fibrillation/flutter. However, the ANtiarrhythmic trial with DROnedarone in Moderate-to-severe congestive heart failure Evaluating morbidity Decrease (ANDROMEDA) study, performed in patients with left ventricular dysfunction, demonstrated excess noncardiac mortality in patients treated with dronedarone. Although effective in the treatment of atrial fibrillation, the future of this novel amiodarone-like drug remains uncertain until further clarification of the excess mortality in heart failure patients is better studied.

Role of intracardiac ultrasound in interventional electrophysiology.

PURPOSE OF REVIEW: Interventional procedures in the electrophysiology and catheterization laboratory are rapidly advancing. Critical to the advancement of these procedures is accurate identification of critical anatomic landmarks and catheter position. Fluoroscopy remains the mainstay for general identification of anatomic landmarks but is inadequate for the precise imaging needed for complex procedures. Precise imaging of anatomic landmarks and catheter position is now possible during the procedure with the use of intracardiac echocardiography (ICE). This paper reviews the rapid development and utilization of ICE in interventional electrophysiology. RECENT FINDINGS: Several recent studies show ICE as a major contribution to providing a safer, more reliable, and more cost-effective means of accomplishing the tasks performed by existing techniques. In the electrophysiology laboratory, the dependence on this new technology has been due to the rapid development of catheter-based radiofrequency ablation of the pulmonary veins for treatment of atrial fibrillation. Since the initial use of ICE in facilitating ablation of atrial fibrillation, other uses for ICE are continuously being identified. SUMMARY: A comprehensive look is provided at the history and development of this new technology along with the most recent applications of ICE in interventional electrophysiology.

Atrial fibrillation in patients with heart failure.

Atrial fibrillation and heart failure are very common cardiac disorders, and both are associated with symptoms, significant morbidity, and mortality. Studies have attempted to determine the prognostic significance of atrial fibrillation in patients with heart failure. Whether atrial fibrillation is an independent risk factor of mortality remains controversial. Multiple trials using either pharmacologic or nonpharmacologic therapies in an attempt to manage atrial fibrillation have been developed. The purposes of this review are to present an overview of atrial fibrillation in patients with heart failure and to discuss the prevalence, prognostic significance, complications, mechanisms, and trials that have formed the therapies presently used.

Atrial fibrillation in heart failure: prognostic significance and management.

AF in Heart Failure. Atrial fibrillation and congestive heart failure are commonly occurring cardiac disorders that often exist concomitantly. The prognostic significance of the presence or absence of atrial fibrillation, as an independent risk factor, in patients with heart failure remains controversial. Antiarrhythmic drugs with good hemodynamic profiles and neutral effects on survival are preferred treatments for converting atrial fibrillation and maintaining sinus rhythm. Other standard therapies for congestive heart failure, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta-blockers also have a role in the treatment of these coexisting disease states. The article presents an overview of atrial fibrillation in patients with heart failure and reviews the prevalence, prognostic significance, and efficacy of various antiarrhythmic agents for the conversion and maintenance of sinus rhythm.

Arrhythmias in Patients with Heart Failure.

Both atrial and ventricular arrhythmias are very common in patients with congestive heart failure, and their presence is associated with symptoms, significant morbidity, and mortality. Studies have attempted to determine the prognostic significance of atrial and ventricular arrhythmias in patients with heart failure. Whether atrial fibrillation is an independent risk factor of mortality remains controversial. The presence of ventricular arrhythmias in patients with ischemic cardiomyopathy identifies patients at high risk for sudden death. However, in patients with nonischemic cardiomyopathy there is not a strong correlation between ventricular arrhythmias and increased risk for sudden death. Multiple trials using antiarrhythmic drugs, pharmacologic therapy, and implantable cardioverter defibrillators have been performed in an attempt to improve survival in patients 1) post-myocardial infarction; 2) with congestive heart failure, with and without nonsustained ventricular tachycardia; and 3) with sustained ventricular tachycardia and those who have survived an out-of-hospital cardiac arrest. The purpose of this article is to present an overview of arrhythmias in patients with heart failure and discuss the prevalence, prognostic significance, complications, mechanisms, and trials that have formed the current therapies presently used.

Nasoalveolar cysts: a review of two cases.

Nasoalveolar cysts, also referred to as Klestadt's or nasolabial cysts, though well-recognized, are very rare. Patients with these nonodontogenic cystic masses may present to the otolaryngologist-head and neck surgeon with either intranasal, gingival, or perinasal soft-tissue complaints. The congenital nature of these soft-tissue cysts necessitates that the clinician be aware of the embryology of these lesions when planning a surgical approach to their removal. The authors present two such cases, both in middle-aged females, with left-sided nasoalveolar cysts, who presented to the senior author's practice within 1 month of each other.

Concurrent Poland's syndrome and gynecomastia: a case report.

Gynecomastia (enlargement of the male breast) is a common occurrence during puberty and usually resolves. Poland's syndrome or hypoplasia of the chest wall is a rare congenital anomaly associated with hypoplasia of the ipsilateral extremity. Simultaneous presentation of gynecomastia and Poland's syndrome in a 26-year-old man increased the extent of asymmetry and the perception of each deformity. Surgical reduction of the enlarged breast greatly reduced the asymmetry, giving a satisfactory result.

The evaluation of intranasal topical beclomethasone spray in the treatment of children with non-purulent rhinitis using rhinometric, cytologic and symptomatologic assessment.

The diagnosis and treatment of non-purulent rhinitis in the pediatric population poses a challenge to the clinician. In this randomized double blind study, the authors conclude that rhinometry is more effective than cytologic or symptomologic assessment in children with non-purulent rhinitis treated with either intranasal beclomethasone or placebo spray. Intranasal beclomethasone spray produced significant reductions in nasal airflow resistance values compared to the placebo-treated group.

The nasolabial flap. Axial or random?

Considerable confusion exists regarding the nature of the blood supply of the inferiorly based nasolabial flap. This report seeks to clarify the situation. Anatomic dissections were performed on 12 cadaveric specimens and microangiography on six others. We confirmed that the facial artery passes deep to the facial mimetic muscles and is not normally included within the flap. Although the vasculature of the flap is technically random, the small vessels of the subdermal plexus are generally oriented along its long axis giving it a "degree of axiality." We believe this vascular orientation is responsible for the flap's reliability.

Effects of ozone exposure: a comparison between oral and nasal breathing.

Mode of inhalation, by nose or by mouth, as a determinant of pulmonary toxicity to acute inhalant exposure has been investigated incompletely. This communication addresses whether there are significant differences in toxic pulmonary responses to acute ozone (O3) exposure between differing modes of inhalation (nasal vs. oral breathing). Changes in the results of pulmonary function tests and symptomatology of healthy young adults were compared following both exclusive nose and exclusive mouth breathing during a 30-min exposure to approximately 0.4 ppm O3 under conditions of moderate continuous exercise. In this single-blind, randomized, crossover study, no significant differences in either the results of pulmonary function tests or in symptomatology were found between the two modes of inhalation.

Free jejunal grafts in pharyngoesophageal reconstruction.

The free jejunal graft with microvascular anastomosis offers the head and neck surgeon a reliable, single-stage method of repair for small cervical defects and also for more extensive pharyngoesophageal defects where one or more loops of jejunum can successfully be used. If microvascular expertise is available, this method of reconstruction offers early alimentary rehabilitation and a physiologic repair. The free jejunal graft is a reliable method of reconstruction not only after failed gastric pull-up or when that procedure is not feasible, but also, where the facilities exist, as a primary method of pharyngoesophageal reconstruction.

Extensive pharyngo-oesophageal reconstruction using multiple jejunal loops.

Two patients underwent subtotal pharyngo-oesophageal reconstruction using jejunum transferred by means of microvascular anastomosis. In both cases, two sets of vascular anastomoses were required, one in the lower neck and the other at the mid-sternal level. In the first patient, a continuous length of jejunum was employed but this led to great redundancy of the bowel on account of coiling as a result of its mesenteric attachment. In the second case, two isolated loops were employed with minimal redundancy. An anatomical study on three fresh cadavers indicated that the maximum defect which can be bridged by a single loop of jejunum lies between 15 and 20 cm. No particular part of the jejunum or ileum seems particularly advantageous in terms of its ability to span large defects.