EFFECT OF CHRONIC ETHANOL ADMINISTRATION ON THIAMINE TRANSPORT IN MICROVILLOUS VESICLES OF RAT SMALL INTESTINE

The effect of long-term ethanol administration on the membranemechanism of thiamine entry in rat enterocytes was investigatedby using microvillous vesicles of small intestine. Experimentswere carried out in three groups of Wistar albino rats of bothsexes (290–400 g of initial body wt). Group I did notreceive any treatment, group II received 4.7 g of ethanol/kgbody wt (as a 50% hydroalcoholic solution) daily by gastricgavage for 35 days and group III (pair-fed controls) receiveda daily solution of saccharose (isoenergetic with the dose ofethanol administered to group II) by gastric gavage for 35 days.Ethanol or saccharose were administered in the morning and astandard diet was given throughout the treatment period. Allanimals were killed by decapitation 24 hr after the last administration,when the blood level of ethanol was virtually zero. Microvilloussmall intestinal vesicles were incubated with ³H-thiamine (³H-T)at 25°C and the amount of ³H-T taken up was measured bya rapid filtration method. Compared with data obtained in groupsI and III, chronic ethanol administration was found to inducea statistically significant decrease in ³H-T vesicular uptakeat 4 sec (determined at ³H-T concentrations ranging from 0.12to 7.5 µM) and a decrease in the apparent J_max (maximaltransport rate) value of the saturable component, without affectingthe apparent K_m (half-saturation concentration) value. These results indicate that in rats chronic ethanol administrationmay impair the intestinal absorption of thiamine by reducingthiamine entry into the enterocyte.     

Two-to-One AV Block Associated with the Congenital Long QT Syndrome

2:1 AV Block in LQTS. Introduction Conduction abnormalities associated with long QT syndrome (LQTS) have been reported as "pseudo 2:1 AV block" due to sinus intervals shorter than ventricular refractoriness.
Method and Results: We report the electrophysiologic characteristics of a patient suffering from congenital LQTS with episodes of true 2:1 AV block. Induction of 2:1 infra-Hisian blocks and return to 1:1 conduction were observed using single atrial and ventricular extrastimuli. The block was located in the Purkinje network but not in the myocardium.
Conclusion: The His-Purkinje system of our LQTS patient displayed dynamic properties with a strong increase in refractoriness for short-long sequences and a decrease for long-short sequences that triggered intermittent 2:1 AV blocks.     

Postinfarction Left Ventricular Free Wall Rupture: Original Management and Surgical Technique

A case of postinfarction left ventricular free wall rupture is successfully treated. Prompt diagnosis was provided by echocardiography and an emergency operation was carried out. Following sternotomy, hemodynamic stabilization was obtained by gradually evacuating blood from the pericardium, while the femoral vessels were cannulated and the extracorporeal circulation was established. An autologous glutaraldehyde stiffened pericardial patch was sealed over the infarcted area using fibrin glue and fixed with a running suture on the surrounding healthy myocardium.     

A Short‐Term,Randomized, Double‐Blind,Parallel‐Group Study to Evaluate the Efficacy and Safety of Dronedarone versus Amiodarone in Patients with Persistent Atrial Fibrillation: The DIONYSOS Study

Dronedarone versus Amiodarone in Patients with AF. Introduction: We compared the efficacy and safety of amiodarone and dronedarone in patients with persistent atrial fibrillation (AF). Methods: Five hundred and four amiodarone‐naïve patients were randomized to receive dronedarone 400 mg bid (n = 249) or amiodarone 600 mg qd for 28 days then 200 mg qd (n = 255) for at least 6 months. Primary composite endpoint was recurrence of AF (including unsuccessful electrical cardioversion, no spontaneous conversion and no electrical cardioversion) or premature study discontinuation. Main safety endpoint (MSE) was occurrence of thyroid‐, hepatic‐, pulmonary‐, neurologic‐, skin‐, eye‐, or gastrointestinal‐specific events, or premature study drug discontinuation following an adverse event. Results: Median treatment duration was 7 months. The primary composite endpoint was 75.1 and 58.8% with dronedarone and amiodarone, respectively, at 12 months (hazard ratio [HR] 1.59; 95% confidence interval [CI] 1.28–1.98; P < 0.0001), mainly driven by AF recurrence with dronedarone compared with amiodarone (63.5 vs 42.0%). AF recurrence after successful cardioversion was 36.5 and 24.3% with dronedarone and amiodarone, respectively. Premature drug discontinuation tended to be less frequent with dronedarone (10.4 vs 13.3%). MSE was 39.3 and 44.5% with dronedarone and amiodarone, respectively, at 12 months (HR = 0.80; 95% CI 0.60–1.07; P = 0.129), and mainly driven by fewer thyroid, neurologic, skin, and ocular events in the dronedarone group. Conclusion: In this short‐term study, dronedarone was less effective than amiodarone in decreasing AF recurrence, but had a better safety profile, specifically with regard to thyroid and neurologic events and a lack of interaction with oral anticoagulants. (J Cardiovasc Electrophysiol, Vol. 21, pp. 597‐605, June 2010)     

Immunoelectron microscopic characterization of a subpopulation of freshly isolated epidermal Langerhans cells that reacts with anti-CD23 monoclonal antibody

Large subsets of leucocytes were recently shown to express the low affinity receptor for the Fc portion of IgE. Because Langerhans cells (LC) are epidermal leucocytes, we investigated whether LC of normal human subjects might express this receptor. Whereas conventional immunofluorescence on epidermal sheets gave negative results, highly sensitive immunoelectron microscopy revealed that a subset (about one-third) of freshly isolated LC express the CD23 molecule.     

Push-out bond strength and SEM evaluation of a new bonding approach into the root canal

Objective

This study evaluated the performance of different adhesive systems in fiber post placement aiming to clarify the influence of different hydrophobic experimental blend adhesives, and of one commercially available adhesive on the frictional retention during a luting procedure.

Material and Methods

One luting agent (70 Wt% BisGMA, 28.5% TEGDMA; 1.5% p-tolyldiethanolamine) to cement fiber posts into root canals was applied with 4 different adhesive combinations: Group 1: The etched roots were rinsed with water for 30 s to remove the phosphoric acid, then rinsed with 99.6% ethanol for 30 s, and blotdried. A trial adhesive (base to catalyst on a 1:1 ratio) was used with an experimental luting agent (35% Bis-GMA, 14.37% TeGDMA, 0.5% eDMAB, 0.13% CQ); Group 2: A trial adhesive (base to catalyst on a 1:2 ratio) was luted as in Group 1; Group 3: One-Step Plus (OSP, Bisco Inc.) following the ethanol bonding technique in combination with the luting agent as in Group 1; Group 4: OSP strictly following the manufacturer''s instructions using the luting agent as in Group 1. The groups were challenged with push-out tests. Posted root slices were loaded until post segment extrusion in the apical-coronal direction. Failure modes were analyzed under scanning electron microscopy.

Results

Push-out strength was not significantly influenced by the luting agent (p>0.05). No statistically significant differences among the tested groups were found as Group 1 (exp 1 - ethanol-wet bonding technique)=Group 2 (exp 2 - ethanol-wet bonding technique)=Group 3 (OSP - ethanol-wet bonding technique)=Group 4 (control, OSP - water-wet bonding technique) (p>0.05). The dominating failure modes in all the groups were cohesive/adhesive failures, which were predominantly observed on the post/luting agent interface.

Conclusions

The results of this study support the hypothesis that the proposal to replace water with ethanol to bond fiber posts to the root canal using highly hydrophobic resin is plausible, but this seems to be more the proof of a concept than a clinically applicable procedure.     

Blood group antigens: synthesis of Ss antigenic peptides related to human glycophorinB

The human Ss blood group antigens are located on glycophorin B, a minor human erythrocyte membrane glycoprotein. The structural difference in Ss antigens is determined by a Met/Thr polymorphism at position 29. This report describes the first synthesis of the two peptides carrying the Ss specificities, SS: Asn-Gly-Glu-Met-Gly-Gln-Leu-Val and ss: Asn-Gly-Glu-Thr-Gly-Gln-Leu-Val.