An improved technique for treating tracheostomal stenosis following laryngectomy

Stenosis of the tracheostome is an occasional complication following laryngectomy. Having tried a number of procedures recommended for correction of such stenoses with limited results, we developed a new technique. This technique which is based on multiple Y-V plasties has been applied to 20 patients. Measurements of the stomal area following surgery in 18 patients showed an average increase in stomal size by a factor of 3.8. One patient apparently had no increase of the stoma. In 2, no post-operative measurements were available. Post-operative infection resulted in recurrence of the stenosis in one patient. He was successfully reoperated using the same technique. Follow-up revealed that none of the patients had complaints related to their stoma.     

Amino acid composition of acquired enamel pellicle collected in vivo after 2 hours and after 24 hours

Abstract— The adsorption of salivary proteins to dental enamel during pellicle formation has been shown to be a specific process and dependent on the chemical composition of the surfaces. Most studies on the amino acid composition of the acquired enamel pellicle have, however, been performed on the "2-h-pellicle"under controlled experimental conditions. This may have eliminated some natural factors involved in pellicle formation. The aim of the present study was to investigate the effect of extended time of formation and diet on the pellicle formation. Pellicle material was collected from the same subject after 2 and after 24 h when food and beverages were avoided, and after 24 h with the intake of a normal diet. The collected pellicle materials were hydrolyzed and amino acid analyzed. The results showed that pellicle material collected after 24 h and fasting had a chemical composition similar to the "2-h-pellicle", whereas pellicle material collected after 24 h and a normal diet was different, indicating a dietary contribution to pellicle formation or a bacterial degradation of the pellicle.     

Susceptibility of glycans to β-elimination in Fmoc-based O-glycopeptide synthesis

order to investigate the possible extent of β-elimination occuring in Fmoc-based continuous-flow solid-phase glycopeptide synthesis, the influence of the pK_b of the base used for N^α-deprotection has been studied. A glycosylated pentapeptide as synthesized using 50%morpholine, 10%, piperidine or 2% DBU, respectively, in DMF for deprotection. The dehydropentapeptide N^α-.Ac-Thr-Thr-δAba-Val-Thr-NH₂, which would be formed in the case of β-elimination, was prepared independently and used as a control in HPLC analysis; however, this product was not formed under any of the deprotection conditions applied. Furthermore, a 23 amino acid long glycopeptide from human intestinal mucin was prepared using 2% DBU as a base for Fmoc cleavage, and similarly no β-elimination was observed. The glycopeptide products were subjected to a prolonged treatment with sodium hydroxide in methanol/water without significant formation of byproducts, and the pure glycopeptides were isolated and characterized by ¹H-NMR spectroscopy.     

Effect of Zendium toothpaste on recurrent aphthous stomatitis

Abstract – A Double-blind clinical trial with cross-over was conducted for a period of 12 months in 25 patients with recurrent aphthous stomatitis (RAS). The effect of the amyloglucosidase and glucoseoxidase containing Zendium toothpaste on the discomfort, number of exacerbations, duration of exacerbation, number of ulcers and number of days with pain caused by RAS was studied. The use of Zendium significantly reduced the sensation of discomfort from RAS as compared to the use of placebo toothpaste (0.025>p>0.01). However, the patients were unable to discriminate significantly between Zendium and placebo when asked to choose one of the toothpastes (0.10>p>0.05) and no significant differences were demonstrated as far as the above mentioned parameters of disease serverity were concerned. Therefore, it is concluded that the reducing effect of Zendium containing amyloglucosidase and glucoseoxidase on RAS is weak as compared to a similar toothpaste without these enzymes.     

Chemical analysis and scanning electron microscopy of acquired pellicle formed in vivo on stannous fluoride treated enamel

Abstract – Stannous fluoride (SnF₂) has been shown to be an effective caries preventive agent. After topical treatment of enamel surfaces, two reaction products have been demonstrated to precipitate on the surfaces, a larger type of globules, probably a calcium fluoride like product, and a smaller type of globules, probably a tin phosphate. The aim of the present study was to examine the amino acid composition and the formation of the acquired pellicle on SnF₂-treated enamel in vivo. The chemical composition was examined by amino acid analysis of pellicle material collected in vivo from SnF₂-treated enamel surfaces. Pellicle formation was examined by scanning electron microscopy on SnF₂-treated enamel fragments carried in the mouth for 2 h. The results showed that pellicle material was formed in abundant amounts and covered the globular surfaces following the SnF₂ treatment. The chemical analyses showed amino acid profiles with high content of acidic and neutral amino acids. The profiles were different from known amino acid profiles obtained from analyses of pellicle material collected from untreated enamel surfaces.     

Pharmacological Activation of IKr Impairs Conduction in Guinea Pig Hearts

Activation of I_Kr Impairs Conduction. Introduction: The hERG (Kv11.1) potassium channel underlies cardiac I_Kr and is important for cardiac repolarization. Recently, hERG agonists have emerged as potential antiarrhythmic drugs. As modulation of outward potassium currents has been suggested to modulate cardiac conduction, we tested the hypothesis that pharmacological activation of I_Kr results in impaired cardiac conduction. Methods and Results: Cardiac conduction was assessed in Langendorff‐perfused guinea pig hearts. Application of the hERG agonist NS3623 (10 μM) prolonged the QRS rate dependently. A significant prolongation (16 ± 6%) was observed at short basic cycle length (BCL 90 ms) but not at longer cycle lengths (BCL 250 ms). The effect could be reversed by the I_Kr blocker E4031 (1 μM). While partial I_Na inhibition with flecainide (1 μM) alone prolonged the QRS (34 ± 3%, BCL 250 ms), the QRS was further prolonged by 19 ± 2% when NS3623 was added in the presence of flecainide. These data suggest that the effect of NS3623 was dependent on sodium channel availability. Surprisingly, in the presence of the voltage sensitive dye di‐4‐ANEPPS a similar potentiation of the effect of NS3623 was observed. With di‐4‐ANEPPS, NS3623 prolonged the QRS significantly (26 ± 4%, BCL 250 ms) compared to control with a corresponding decrease in conduction velocity. Conclusion: Pharmacological activation of I_Kr by the hERG agonist NS3623 impairs cardiac conduction. The effect is dependent on sodium channel availability. These findings suggest a role for I_Kr in modulating cardiac conduction and may have implications for the use of hERG agonists as antiarrhythmic drugs. (J Cardiovasc Electrophysiol, Vol. 21, pp. 923‐929, August 2010)     

Significance of Late Recurrence of Atrial Fibrillation during Long-Term Follow-Up after Pulmonary Vein Isolation

Background and Study Objective : Patients with paroxysmal or persistent atrial fibrillation (AF) can be treated by pulmonary vein (PV) isolation. Although the recurrence rate after the procedure is relatively high, the long-term outcomes after initially recurrence-free procedures remains unclear. We examined the rates of recurrence of AF after PV isolation.
Methods: Our study included 278 consecutive patients with drug-refractory AF (mean age = 53 ± 11 years, 228 men). PV isolation was based on the disappearance of PV potentials recorded from a circumferential catheter after segmental ostium ablation. Cavo-tricuspid isthmus lines and additional atrial lines were performed in 124 and 28 patients, respectively. Patients were monitored for a mean of 26 ± 11 months (range 12–56). Recurrence was defined as ≥1 episodes of symptomatic or asymptomatic AF >1 month after the procedure.
Results: A total of 120 (34) patients had ≥1 recurrence of AF >1 month after the procedure, of whom 14 (4) had a first recurrence >6 months after the procedure. There was a significantly higher recurrence rate among patients with persistent AF.
Conclusions : A relatively high AF recurrence rate was observed after PV isolation. AF may recur late after the ablation procedure, though the majority of recurrences occurred within 6 months after the first procedure. There were no differences in incidence or time of occurrence of late recurrences between patients with paroxysmal versus persistent AF.