Electrophysiology of ion channels of the heart

Summary— The contribution of Na+, Ca²⁺, and various K+ currents to the shape of the cardiac action potential is outlined based on the relation between electrophysiological properties and structure of channel molecules. These currents have also been found in human ventricular myocytes, where the most prominent K+ current is a transient outward current that is not influenced by methylsulfonanilide antiarrhythmic drugs. Combined knowledge of electrophysiological and molecular properties of ion channels is likely to form the basis for rational design of future drugs.     

Lymphomatoid papulosis in childhood with exclusive acral involvement [letter]

Abstract: Lichen sclerosus (LS) is a skin disease that may affect both sexes at all ages and at any site. Its etiology remains unknown. The observation of focal koilocytotic-like changes in the stratum malpighii in prepuce samples of LS in children prompted us to investigate the presence of HPV-DNA. Twenty-three paraffin-embedded samples of LS lesions from children aged 4 to 14 years were studied using nested-PCR and in situ hybridization (ISH). Twelve out of 23 cases amplified HPV-DNA (8 cases corresponded to HPV-DNA type 6; 2 cases each to HPV-DNA types 16 and 18). ISH detected HPV sequences in the nuclei of koilocytotic and some parakeratotic cells in 13 cases (9/13 also HPV-DNA positive by PCR). Our results demonstrated the presence of HPV-DNA in roughly 70% of cases of LS of the prepuce in children. We highlight the observation of koilocytotic-like changes in the prepuce and its association with HPV. The possible pathogenetic significance between the virus and the lesion is not settled.     

J wave patterns—morphology,prevalence and nomenclature

The recent resurgence of interest in early repolarization has demonstrated a variation in the definition of the term and a consequent variation in the prevalence of the pattern in different studies. This can vary from 35% in males and 21.5% in females if ST elevation is not considered part of the definition, to 3.3% and 0.5% in females with the inclusion of ST elevation. In contrast, the prevalence of the Brugada Syndrome is in the order of 0.1%–0.2% in Japan for example and has been found to be significantly lower in Denmark. Standardisation of measurement definitions, particularly for early repolarisation, is required.     

In vivo bracket retention comparison of a resin-modified glass ionomer cement and a resin-based bracket adhesive system after a year.

Glass ionomer orthodontic adhesives cause less enamel demineralization during fixed orthodontic appliance treatment than do traditional resin-based products. An in vivo randomized clinical trial was performed comparing the clinical performance of a resin-modified glass ionomer (RMGI) adhesive with a no-mix, resin-based (the control) adhesive over a 12-month period. The split-mouth technique was used to analyze bracket retention, bracket failure causes, and mode of failure for both adhesives in 61 patients. Bracket-failure rates were 10% for the RMGI and 4% for the resin-based adhesive. Both adhesives had 4 times more bracket failures when opposing occlusion was present. The resin-based product demonstrated a higher proportion of resin-to-enamel adhesive failures than did the RMGI. Compared with the resin-based adhesive, the RMGI-bracketed teeth showed improved clinical performance, no enamel surface loss, less enamel demineralization, and faster adhesive removal. However, the RMGI had a 2.6 times greater bracket-failure rate than did the resin-based product.