A Review of the Biologic Effects, Clinical Efficacy, and Safety of Silicone Elastomer Sheeting for Hypertrophic and Keloid Scar Treatment and Management

Silicone elastomer sheeting is a medical device used to prevent the development of and improve the appearance and feel of hypertrophic and keloid scars. The precise mechanism of action of silicone elastomer sheeting has not been defined, but clinical trials report that this device is safe and effective for the treatment and prevention of hypertrophic and keloid scars if worn over the scar for 12 to 24 hours per day for at least 2 to 3 months. Some of the silicone elastomer sheeting products currently on the market are durable and adhere well to the skin. These products are an attractive treatment option because of their ease of use and low risk of adverse effects compared to other treatments, such as surgical excision, intralesional corticosteroid injections, pressure therapy, radiation, laser treatment, and cryotherapy. Additional controlled clinical trials with large patient populations may provide further evidence for the efficacy of silicone elastomer sheeting in the treatment and prevention of hypertrophic and keloid scars. The purpose of this article is to review the literature on silicone elastomer sheeting products and to discuss their clinical application in the treatment and prevention of hypertrophic and keloid scars.     

Ultrasound guided internal jugular vein access in children and infant: A meta‐analysis of published studies

Introduction: Central venous catheter placement is technically difficult in pediatric population especially in the younger patients. Ultrasound prelocation and/or guidance (UPG) of internal jugular vein (IJV) access has been shown to decrease failure rate and complications related to this invasive procedure. The goal of the present study was to perform a systematic review of the advantages of UPG over anatomical landmarks (AL) during IJV access in children and infants. Material and methods: A comprehensive literature search was conducted to identify clinical trials that focused on the comparison of UPG to AL techniques during IJV access in children and infants. Two reviewers independently assessed each study to meet inclusion criteria and extracted data. Data from each trial were combined to calculate the pooled odds ratio (OR) or the mean differences (MD), and their 95% confidence intervals [CI 95%]. I² statistics were used to assess statistics heterogeneity and to guide the use of fixed or random effect for computation of overall effects. Subgroup analysis was used to clarify the effects of the techniques used (prelocation or guidance) or the experience of practitioners. Results: Literature found five articles. Most of the patients were cardiac surgery patients. In comparison with AL, UPG had no effect on IJV access failure rate (OR = 0.28 [0.05, 1.47], I² = 75%, P = 0.003), the rate of carotid artery puncture (OR = 0.32 [0.06, 1.62], I² = 68%, P = 0.01), haematoma, haemothorax, or pneumothorax occurrence (OR = 0.40 [0.14, 1.13], I² = 17%, P = 0.30, OR = 0.72, OR = 0.81 [0.18, 3.73], I² = 0%, P = 0.94, respectively) and time to IJV access and haemothorax/pneumothorax occurrence. Subgroup analysis found an efficacy of ultrasound when used by novice operators or during intraoperative use. Discussion: This current meta‐analysis does not found the utility of ultrasound during IJV access in children and infants in increasing the success rate and in decreasing complications.     

Severe hyponatraemia after plastic surgery in a girl with cleft palate, medial facial hypoplasia and growth retardation

A ten-year-old girl with middle face hypoplasia, cleft lip and palate developed severe hyponatraemia on the first day following surgery. Final diagnosis was inappropriate secretion of antidiuretic hormone (ADH) and complete hormonal investigation revealed partial deficit in growth hormone secretion. The incidence of hormonal deficiency associated to midline facial malformations is discussed.     

Rapid determination and NMR assignments of antiparallel sheets and helices of a scorpion and a cobra toxin

An NMR method is described which should provide a rapid means for determining and assigning antiparallel sheets and helices in small proteins. It begins by locating apparent NOESY crosspeaks which suggest the presence of the secondary structure; this is followed by searches for MCD patterns (Englander & Wand (1987) Biochemistry 22, 5953) which are characteristic of these structures. As a result, only spin-systems of the amino acids within the secondary structure need to be defined. A triple-stranded, antiparallel sheet and a helix have been found and assigned for both α-cobratoxin and the scorpion toxin AaH III.     

Structure and Neural Modulation of Cardiac Calcium Channels

Regulation of Cardiac Ca Channels . The L-type, voltage-gated calcium (Ca) current plays a key role in excitation and initiation of contraction in cardiac muscle cells and is partly responsible for the plateau of the action potential. The ionic channels underlying this current are targets for modulation by the autonomic nervous system. This article reviews recent developments in understanding how these channels are regulated by phosphorylation and G proteins and attempts to relate these findings to recent studies on the molecular structure of the Ca channel.     

Gene Expression of the Natriuretic Peptide System in Atrial Tissue of Patients with Paroxysmal and Persistent Atrial Fibrillation

INTRODUCTION: Circulating cardiac natriuretic peptides play an important role in maintaining volume homeostasis, especially during conditions affecting hemodynamics. During atrial fibrillation (AF), levels of plasma atrial natriuretic peptide (ANP) becomes elevated. The aim of this study was to gather information about gene expression of the natriuretic peptide system on the atrial level in patients with AF. METHODS AND RESULTS: Right atrial appendages of 36 patients with either paroxysmal or persistent AF were compared with 36 case matched controls in sinus rhythm for mRNA expression of pro- atrial natriuretic peptide (pro-ANP), pro-brain natriuretic peptide (pro-BNP), and their natriuretic peptide receptor type-A (NPR-A). We investigated patients without (n = 36) and with (n = 36) valvular disease. Persistent AF was associated with higher mRNA expression of pro-BNP (+66%, P = 0.04, in patients without valvular disease, and +69%, P < 0.01, in patients with valvular disease) and lower mRNA expression of NPR-A (-58%, P = 0.02, in patients without valvular disease, and -62 %, P < 0.01, in patients with valvular disease). The mRNA content of pro-ANP was only increased in patients with valvular disease (+12%, P = 0.03). No changes were observed in patients with paroxysmal AF. CONCLUSION: This study demonstrates that persistent, but not paroxysmal, AF induces alterations in gene expression of pro-BNP and NPR-A on the atrial level. Although AF generally is associated with an increase of plasma ANP level, a change in mRNA content of pro-ANP is only observed in the presence of concomitant valvular disease and is of minor magnitude.     

Contact‐Force Catheters: Efficacy Versus Safety? Case Report of 2 Atrioesophageal Fistulae

Contact‐force (CF) catheters appear to be more effective compared to standard ablation catheters for complex radiofrequency ablation including atrial fibrillation (AF) ablation when optimal CF >10 g is achieved. Some have suggested that this technology could also improve procedural safety. We report 2 cases of atrioesophageal fistulae (AEF), a rare but catastrophic complication of AF ablation. These are to our knowledge the first cases of AEF described after using CF catheters.