Normal range of fetal transcutaneous carbon dioxide tension during labour

Summary. Fetal transcutaneous carbon dioxide tension (tc-Pco), was monitored during 122 deliveries, using an electrode temperature of 44°C in 80 cases and of 41°C in 42 cases. Significant correlations between tc- P co₂ and umbilical artery blood P co₂ were found using both electrode temperatures, but the regression lines indicated a larger and more inconstant CO₂-contribution from skin metabolism when the low electrode temperature was used. Normal range of tc- P co₂ was calculated at 41°C and 44°C electrode temperatures. Mean values of fetal tc- P co₂ were found to increase during normal labour, and especially in fetuses developing acidosis, but only four of six infants born with acidaemia had tc- P co₂ values exceeding the normal range.     

Fluoride concentrations in saliva in relation to chewing of various supplementary fluoride preparations

Abstract – Fluoride concentrations were measured in whole saliva samples collected from 16 subjects at different intervals up to 60 min after chewing of various supplementary F preparations: chewable E tablets (0.21 mg F), plain F tablets (0.25 mg F) or F-containing chewing gum (0.25 mg F). Each of the F preparations was administered in a low dose (0.21–0.23 mg F) or in a high dose (0.42–0.50 mg F). Mean resting levels of fluoride in saliva ranged from 0.03 to 0.05 parts/10⁶. Peak values averaging 15–25 parts F/10⁶ in the low-dose group and 25–40 parts F/10⁶ in the high-dose group were recorded within 5 min after intake. After 30 min, the salivary fluoride concentrations in both groups had decreased to levels below 1 part/10⁶ and approached resting levels 60 min after intake. The availability of fluoride in saliva, as estimated from AUC values (areas under curves, relating fluoride concentrations to the time from 0 to 60 min), was similar with each of the preparations applied in the low dose. When used in the high dose, the chewing gum and also the plain tablets provided significantly more fluoride in saliva than the chewable tablets. The data may suggest that unflavored plain F tablets are equally suitable as a vehicle for fluoride aiming at a topical cariostatic effect as specially designed chawable tablets or chewing gum.     

Pace-Termination and Pacing for Prevention of Atrial Tachyarrhythmias: Results from a Multicenter Study with an Implantable Device for Atrial Therapy

INTRODUCTION: Patients with bradycardia requiring permanent pacing frequently suffer from additional atrial tachyarrhythmias (ATs). This study evaluated the safety and efficacy of atrial antitachycardia pacing (ATP) and the performance of pacing for AT prevention implemented into a new pacemaker. METHODS AND RESULTS: In patients with conventional indications for permanent pacing, an investigational DDDRP pacemaker (Medtronic AT500, model 7253) was implanted. The primary study objectives were to determine the safety of overall device functioning and its efficacy in terminating spontaneous AT. A secondary endpoint was to determine the reliability of AT detection. Pacemaker memory functions were used to analyze the impact of dedicated pacing algorithms on AT prevention. In 33 European and Canadian centers, 325 patients were enrolled (mean follow-up 2.3+/-1.3 months). Complication-free survival at 3 months was 88%. In 2,145 episodes stored with atrial electrograms, AT detection was confirmed in 97%. The algorithm for continuous overdrive pacing increased the percentage of atrial pacing to 97%. After ATP activation, 16,683 of 52,468 AT episodes were treated (120 patients). Of these, 8,903 episodes (53%) were terminated successfully by ATP. No proarrhythmic effect of preventive pacing or atrial ATP was observed. Preventive pacing algorithms increased the median percentage of atrial pacing from 62% to 97%. However, the number of AT/AF (atrial fibrillation) episodes (4.1 vs 4.1 per patient per day) and the time in AT/AF (13.7% vs 12.8%) was not significantly different before and after activation of preventive pacing. CONCLUSION: DDDRP pacing with a new system for AT therapy was safe and associated with successful pace-termination of AT in 53% of episodes. Preventive pacing and atrial ATP algorithms represent two new functions that can be implemented safely into pacemaker systems for nonpharmacologic treatment of ATs in patients requiring pacemaker therapy.     

Intraoral hydrolysis of monofluorophosphate

Abstract – The intraoral hydrolysis of monofluorophosphate (MFP) was compared in nine subjects with natural teeth and in nine edentulous subjects after a 1-min mouthrinse with a 100 ppm MFP solution. Analyses of total F and F- in whole saliva samples collected up to 15 min after the rinse suggested that apatite catalyzed breakdown of MFP mediated by dental enamel contributes significantly to the intraoral hydrolysis of MFP.     

Study on the dissolution behaviour of calcium fluoride

Abstract – The dissolution of two analytical calcium fluoride preparations was studied in aqueous solution. Dissolved calcium fluoride was determined from analysis Ca and F in solution. Original samples of the two preparations and the residue after partial dissolution were studied by X-ray diffractometry in comparison with natural fluorite. The dissolution of calcium fluoride was found to be extremely slow. After a period of 1–15 weeks, depending on the experimental conditions, a state was reached where apparently no further dissolution occurred, although the solution was far from saturation. The dissolution rate was obviously closely related to the crystal size. On partial dissolution the mean crystal size increased, probably due to the disappearance of the finest fractions. Placing the salt in a dialysis bag before immersion in the water lowered the dissolution rate and increased the undissolved fraction considerably. The results seem to support the assertion that calcium fluoride accumulated in early carious lesions after topical applications of fluoride may persist for considerable periods of time.     

Intake of Drugs among Elderly People in a Danish Municipality,Rødovre

ABSTRACT. Drug intake has been studied among a random group of persons, aged 75 or over, in Rødovre Municipality. Two hundred and eighty-three elderly persons living in their own homes have been visited and interviewed about their daily intake of prescribed and non-prescribed drugs (including so-called natural drugs). Similar information was gathered from 146 elderly persons living in nursing homes. Thirty-one per cent of the elderly living in their own homes and 3% of those living in nursing homes did not use prescribed drugs daily. The median daily amount of different types of drugs used was 1.8 (range 0–10) for elderly persons living in their own homes and 4.5 (range 0–11) (p<0.001) for those living in nursing homes. Women living at home had a higher intake of drugs than men, especially diuretics. The most frequently used drugs were diuretics, sedatives/hypnotics, analgesics, digitalis and electrolytes. For all types of drugs a higher consumption, especially of phenothiazines, was found among elderly persons living in nursing homes. Drug consumption was independent of age and social stratification in both groups. The use of non-prescribed drugs ranges from 0 to 9 different types in the group living in their own homes, and from 0 to 5 in the group living in nursing homes—laxatives being the type most frequently used.     

Safe and Rapid Isolation of Pulmonary Veins Using a Novel Circular Ablation Catheter and Duty-Cycled RF Generator

Background: Ablation of atrial fibrillation (AF) has been one of the most difficult and time-consuming electrophysiological procedures. Due to the rapidly increasing demand for ablation procedures, technical advances would be helpful to reduce complexity and procedure time in AF ablation. Therefore, we investigated the feasibility of a single-catheter technique for pulmonary vein (PV) isolation utilizing a decapolar catheter combined with a duty-cycled, unipolar–bipolar radiofrequency (RF) generator.
Methods: AF mapping and ablation was performed in 21 consecutive patients (mean age 59 ± 12 years, 9 males) with paroxysmal AF (n = 17) and persistent AF (n = 4). The ablation catheter was forwarded to the LA via single-transseptal puncture. All electrodes were energized in 2 to 5 applications per vein, followed by segmental RF applications, as needed, to achieve electrical isolation. To assess left atrial anatomy for purposes of catheter manipulation, and later evaluate the possibility of asymptomatic PV-stenosis, CT or MR imaging was performed both prior to ablation and at 6-month follow-up.
Results: Isolation could be achieved in 85/86 veins (99%). Procedure time for ablation was 81 ± 13 minutes, and fluoroscopy time was 30 ± 11 minutes. There were no procedural complications. Success rate at 6 months was 86% (18/21). MR or CT imaging excluded asymptomatic PV-stenosis.
Conclusion: Mapping and ablation of PVs can be performed in a safe and efficient manner using a single-catheter technique, with short procedure times and minimal learning curve. Thus, this system may be of high interest not only for high volume but all centers performing AF ablation.